Marine vessel propulsion system and marine vessel

A marine vessel propulsion system includes a plurality of propulsion devices, each including a motor and a propeller rotated by the motor. The system further includes a common electric power supply switch arranged to be operated by an operator to turn on and off electric power supplies of the plurality of propulsion devices all at once, an electric power supply control unit arranged to put the electric power supplies of the respective propulsion devices in an on state all at once when the common electric power supply switch is turned on and to put the electric power supplies of the respective propulsion devices in an off state all at once when the common electric power supply switch is turned off, an abnormal state detection unit arranged to detect an abnormal state of each propulsion device, and a power transmission cutoff unit, which is arranged to, when an abnormal state of any of the propulsion devices is detected by the abnormal state detection unit, cut off transmission of power between the motor and the propeller of the propulsion device for which the abnormal state is detected.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a marine vessel propulsion system and a marine vessel that includes a plurality of propulsion devices.

2. Description of the Related Art

An exemplary propulsion device for a marine vessel is an outboard motor. The outboard motor is, for example, attached to a stern of a hull. The outboard motor is an apparatus that obtains a propulsive force by rotation of a propeller by a power of a motor, such as an engine. A plurality of outboard motors may be attached to the hull in accordance with the required propulsive force. The outboard motor includes an outboard motor ECU (electronic control unit) for motor output control, etc.

A steering operation apparatus, a remote controller for adjusting the output of the outboard motor, and a gauge (meter) for displaying a state of the outboard motor are disposed at a marine vessel maneuvering compartment of the marine vessel. The steering operation apparatus includes, for example, a steering wheel. Operation of the steering wheel is transmitted by a cable to the outboard motor to enable the direction of the outboard motor to be changed.

The remote controller has a lever for shift position selection and motor output adjustment of the outboard motor. A position of the lever is detected by a position sensor. Information on the lever position detected by the position sensor is transmitted to the outboard motor. The shift positions are a forward drive position, a neutral position, and a reverse drive position. When the forward drive position is selected, a propeller rotation direction is set to the rotation direction that provides the propulsive force in the forward drive direction to the marine vessel. When the reverse drive position is selected, the propeller rotation direction is set to the rotation direction that provides the propulsive force in the reverse drive direction to the marine vessel. At the neutral position, the output of the motor is not transmitted to the propeller.

In a marine vessel that includes a plurality of outboard motors, a remote controller is provided individually for each outboard motor. However, a system has also been developed by which shift control (shift position selection and engine output adjustment) of all outboard motors in a marine vessel including a plurality of outboard motors is performed by fewer remote controllers than the number of outboard motors. For example, a system by which shift control of three outboard motors is performed by two remote controllers is disclosed in United States Patent Application Publication No. 2008/0119096 A1.

Specifically, one of the remote controllers is associated with an outboard motor at a starboard-side, the other remote controller is associated with an outboard motor at a port-side, and both remote controllers are associated with an outboard motor at a center to execute outboard motor control in accordance with operations of the remote controllers. Specifically, when the lever positions of both remote controllers are at the forward drive positions, the shift position of the central outboard motor is controlled to be at the forward drive position. When the lever positions of both remote controllers are at the reverse drive positions, the shift position of the central outboard motor is controlled to be at the reverse drive position. In a case where the combination of the lever positions of the two remote controllers is a combination other than the above, the shift position of the central outboard motor is controlled to be at the neutral position.

The gauge includes a display unit and is arranged to display an operation state of the outboard motor, the motor output (rotational speed), etc. When a plurality of outboard motors are included, a plurality of gauges are included accordingly and displays corresponding to the respective outboard motors are performed.

One battery is included for each outboard motor. In a case where an engine (internal combustion engine) is included as the motor, electric power is supplied from this battery to a starter for starting the engine and to the outboard motor ECU. The marine vessel maneuvering compartment includes an electric power supply switch arranged to switch between supplying and cutting off the electric power supply from the battery to the outboard motor. When a plurality of outboard motors are included, a plurality of electric power supply switches are included accordingly. The electric power supply switch is, for example, a key switch with which a main key is inserted and rotated, and serves in common as a start switch for starting the engine. More specifically, when a user operates the key switch from an off position to an on position, electric power is supplied from the battery to the outboard motor. When the key switch is operated further from the on position to the start position, the starter is actuated and a cranking operation is performed.

In a case where a plurality of outboard motors are included, electric power supply switches of a number corresponding to the number of outboard motors are present, and a user must carry around a plurality of main keys of a number corresponding to the number of outboard motors, which is troublesome. Provision of a single, common electric power supply switch in place of individual electric power supply switches for a plurality of outboard motors is thus proposed in United States Patent Application Publication No. 2004/0121666 A1. In such a case where a common electric power supply switch is provided, the main key can be consolidated to a single key and carrying of the main key is facilitated.

SUMMARY OF THE INVENTION

The inventors of preferred embodiments of the present invention described and claimed in the present application conducted an extensive study and research regarding a marine vessel propulsion system, such as the one described above, and in doing so, discovered and first recognized new unique challenges and previously unrecognized possibilities for improvements as described in greater detail below.

In the case where the single, common electric power supply switch is provided in place of individual electric power supply switches for the plurality of propulsion devices (for example, outboard motors), the carrying of the main key switch is facilitated as mentioned above. However, a problem may occur in a marine vessel adopting a system with which shift control of the plurality of propulsion devices installed on the hull is performed by fewer remote controllers than a total number of the propulsion devices.

This point shall now be described with reference toFIGS. 24A-24D. A marine vessel shown inFIGS. 24A-24Dincludes three propulsion devices (outboard motors)3P,3C, and3S. Here, it shall be assumed that, in this marine vessel, shift control of the three propulsion devices is performed by commands from two remote controllers. A case where a fault occurs in a motor (for example, engine) of the single propulsion device3C at the center during travel by the three propulsion devices as shown inFIG. 24Ashall now be assumed. In this case, a user (operator) performs an operation of stopping the motor of faulty central propulsion device3C by a start/stop switch corresponding to the central propulsion device3C as shown inFIG. 24B. Here, an individual electric power supply switch is not provided, and thus the electric power supply of just the faulty central propulsion device3C cannot be turned off. That is, although the motor of the propulsion device3C can be stopped, the electric power supply of the propulsion device3C remains on.

The electric power supply of the propulsion device3C is still on and thus when travel using the other two propulsion devices3P and3S is performed thereafter, the shift position of the stopped central propulsion device3C is controlled to be at the forward drive position or the reverse drive position depending on the lever positions of the two remote controllers. For example, when the levers of the two remote controllers are operated to the forward drive positions, the shift position of the central propulsion device3C is set at the forward drive position. That is, a state in which a power transmission path between the motor and the propeller is connected is entered.

The propeller of the stopped propulsion device3C rotates upon receiving a force of a relative water stream generated in accompaniment with the traveling of the marine vessel. If the shift position of the propulsion device3C is at the forward drive position or the reverse drive position at this time, the rotation of the propeller is transmitted to a driving shaft (for example, a crankshaft) of the motor as shown inFIG. 24C. Starting of the motor may thereby occur. In the present specification, such rotation of the driving shaft of the motor included in the stopped propulsion device by the force that the propeller of the propulsion device receives from a water stream shall be referred to as “entrained rotation.”

When the driving shaft is rotated in a state where a fault is occurring in the motor, depending on the type of fault, the motor may become damaged to an unrepairable degree as shown inFIG. 24D. For example, in a case where the motor is an engine, if the engine is started by entrained rotation after the engine has been stopped due to lowering of hydraulic pressure due to fault of an oil pump, the engine may become seized due to lack of hydraulic pressure.

As a matter of course, even in a case where the motor is not faulty, entrained rotation may occur in a case where a specific motor is in a driving-stopped state with its electric power supply being on. The motor may thus start against an intention of the user.

In order to overcome the previously unrecognized and unsolved challenges described above, a preferred embodiment of the present invention provides a marine vessel propulsion system including a plurality of propulsion devices, each in turn including a motor and a propeller rotated by the motor. The system further includes a common electric power supply switch arranged to be operated by an operator for turning on and off electric power supplies of the plurality of propulsion devices all at once, an electric power supply control unit arranged and programmed to put the electric power supplies of the respective propulsion devices in an on state all at once when the common electric power supply switch is turned on and to put the electric power supplies of the respective propulsion devices in an off state all at once when the common electric power supply switch is turned off, an abnormal state detection unit arranged to detect an abnormal state of each propulsion device, and a power transmission cutoff unit which is arranged to, when an abnormal state of any of the propulsion devices is detected by the abnormal state detection unit, cut off transmission of power between the motor and the propeller of the propulsion device for which the abnormal state is detected. “Motor” inclusively refers to an internal combustion engine, an electric motor, etc.

By this arrangement, the electric power supplies of the plurality of propulsion devices can be turned on all at once or turned off all at once by operating the common electric power supply switch (which may be a single common electric power supply switch). Thus, in a case where the common electric power supply switch is arranged as a key switch, consolidation of a main key for turning on and off the electric power supplies of the plurality of propulsion devices is enabled.

Also, when an abnormal state of any of the propulsion devices is detected, the transmission of power between the motor and the propeller of the propulsion device for which the abnormal state is detected is cut off. When the transmission of power between the motor and the propeller of propulsion device is cut off, even when the propeller is rotated due to water resistance during traveling of the marine vessel, the rotational force is not transmitted to the motor of the propulsion device. Entrained rotation thus does not occur. Problems due to entrained rotation can thus be avoided. Specifically, in a case where the motor is an engine (internal combustion engine), starting of the engine due to unintended cranking can be avoided.

Each of the propulsion devices may include a clutch mechanism that is switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the power transmission between the motor and the propeller is cut off. In this case, the power transmission cutoff unit may include a clutch control unit that is programmed to control the clutch mechanism to be in the cutoff state.

The clutch mechanism may be a shift mechanism enabling selection of a shift position among any of a forward drive position, a neutral position, and a reverse drive position. The forward drive position is a shift position at which a driving force of the motor is transmitted in a direction in which the propeller undergoes forward drive rotation. The neutral position is a shift position at which the driving force of the motor is not transmitted to the propeller. The reverse drive position is a shift position at which the driving force of the motor is transmitted in a direction in which the propeller undergoes reverse drive rotation. The forward drive rotation is a rotation in a direction in which the propeller applies a forward drive direction propulsive force to a hull. The reverse drive rotation is a rotation in a direction in which the propeller applies a reverse drive direction propulsive force to the hull. The forward drive position and the reverse drive position correspond to the transmitting state, and the neutral position corresponds to the cutoff state.

Preferably, in a case where the propulsion devices include the clutch mechanisms, a clutch state selection operation unit arranged for an operator to select states of the clutch mechanisms in the plurality of propulsion devices is further included. Preferably, in this case, the power transmission cutoff unit cuts off the transmission of power between the motor and the propeller of the propulsion device in the abnormal state regardless of the operation state of the clutch state selection operation unit. More specifically, the clutch state selection operation unit may be a shift position selection operation unit that is arranged for an operator to select the shift positions of the shift mechanisms.

The clutch state selection operation unit may have a fewer number of operation elements than a total number of the plurality of propulsion devices. In this case, the operation elements and the propulsion devices are not in a one-to-one association and at least one operating element is allocated to more than one propulsion device. When an abnormal state occurs in any of these two or more propulsion devices, the transmission of power between the motor and the propeller is cut off in the propulsion device in the abnormal state. Thus, when the associated operation element is operated, whereas the driving force of the motor can be transmitted to the propeller depending on the state of the clutch in the propulsion device without abnormality, a driving shaft of the motor is cut off from the propeller in the propulsion device in which the abnormality occurred.

As mentioned above, the motor may be an engine (internal combustion engine) or an electric motor.

The propulsion device may be in a form of an outboard motor, an inboard/outboard motor (a stern drive or an inboard motor/outboard drive), or an inboard motor. The outboard motor includes a propulsion unit provided outboard of the vessel and including a motor and a propeller, and is further provided with a steering mechanism that turns the entire propulsion unit horizontally with respect to the hull. The inboard/outboard motor includes a motor disposed inboard of the vessel, and a drive unit disposed outboard and including a propeller and a steering mechanism. The inboard motor preferably has a form where both a motor and a drive unit are incorporated in the hull, and a propeller shaft extends outboard from the drive unit.

In a preferred embodiment of the present invention, the abnormal state detection unit includes an entrained rotation detection unit that is arranged to detect rotation of the driving shaft of a motor due to entrained rotation as an abnormal state of the propulsion device that includes the motor.

By this arrangement, the rotation of the driving shaft of the motor due to entrained rotation is detected as an abnormal state of the propulsion device that includes the motor. The transmission of power between the motor and the propeller of the propulsion device is thus cut off promptly when entrained rotation occurs.

In a preferred embodiment of the present invention, the entrained rotation detection unit is arranged to detect that the driving shaft of a motor is rotating due to entrained rotation when, from a state where the motor is stopped, the driving shaft of the motor rotates with a starting device of the motor not being driven, or when, after starting a stopping process on the motor that is in a running state, the rotation of the driving shaft of the motor does not stop within a predetermined time.

By this arrangement, the transmission of power between the motor and the propeller can be cut off when, despite the motor being stopped once, the driving shaft of the motor begins to rotate thereafter due to entrained rotation. Further, by this arrangement, the transmission of power between the motor and the propeller can be cut off when, despite the stopping process being performed on the motor that is in operation, the rotation of the driving shaft of the motor does not stop due to entrained rotation. The entrained rotation state can thereby be resolved promptly to stop the motor reliably.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a notification unit arranged to notify the cutting off of transmission of power between the motor and the propeller of a propulsion device for which an abnormal state is detected when the power transmission cutoff unit cuts off the transmission of power between the motor and the propeller of the propulsion device.

By this arrangement, when the transmission of power between the motor and the propeller of a propulsion device, for which an abnormal state is detected, is cut off, this is notified to a user (operator) by the notification unit. The user can thus recognize that the transmission of power between the motor and the propeller is cut off regardless of an operation state (for example, a position of an operation element) of the shift position selection operation unit. The user can thus be prevented from mistaking that the shift position selection operation unit or a shift mechanism of a propulsion device is faulty when these elements are not faulty.

In a preferred embodiment of the present invention, each of the propulsion devices includes a clutch mechanism that is arranged to be switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the transmission of power between the motor and the propeller is cut off. The marine vessel propulsion system further includes a clutch state selection operation unit arranged for an operator to select states of the clutch mechanisms in the plurality of propulsion devices. Further, the power transmission cutoff unit is arranged such that when the transmission of power between the motor and the propeller of a propulsion device for which an abnormal state is detected is cut off, the cutoff state is maintained until a selection operation for putting the state of the clutch mechanism of the propulsion device in the cutoff state is performed by the clutch state selection operation unit.

In a preferred embodiment of the present invention, the power transmission cutoff unit is arranged such that when the transmission of power between the motor and the propeller of a propulsion device for which an abnormal state is detected is cut off, the cutoff state is maintained until the motors of all propulsion devices are stopped.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a speed detection unit that is arranged to detect a speed of the marine vessel. The power transmission cutoff unit is arranged such that when the transmission of power between the motor and the propeller of a propulsion device for which an abnormal state is detected is cut off, the cutoff state is maintained until the speed of the marine vessel detected by the speed detection unit becomes no more than a predetermined threshold value.

Here, for example, it shall be assumed that an abnormal state of one propulsion device is detected during traveling of the marine vessel and the transmission of power between the motor and the propeller of the propulsion device is cut off. The entrained rotation state is thereby resolved, and thus the abnormal state detection unit at least no longer detects the entrained rotation abnormality. Thus, if the clutch state is controlled in accordance with operation of the clutch state selection operation unit immediately after the abnormal state is no longer detected, needless clutch control may be performed. That is, there is a possibility for power transmission cutoff control based on abnormal state detection and clutch control in accordance with operation of the clutch state selection operation unit based on cancellation of the abnormal state to be repeated alternately.

By providing the arrangement described above, the repetition of the detection of the abnormal state and the cancellation of the abnormal state is prevented and the abovementioned clutch control and other control can be prevented from being performed needlessly.

A docking detection unit that is arranged to detect that the marine vessel is docked may be provided, and the power transmission cutoff unit may be arranged such that when the transmission of power between the motor and the propeller of a propulsion device for which an abnormal state is detected is cut off, the cutoff state is maintained until the docking of the marine vessel is detected. As the docking detection unit, for example, an arrangement that uses a navigation apparatus arranged to detect that the marine vessel is docked at a scheduled docking position set in advance may be used. Also, as the docking detection unit, an arrangement that is arranged to measure a distance to a scheduled docking position by a laser and to detect that the marine vessel is docked when the distance becomes no more than a predetermined value may be used. Further, as the docking detection unit, an arrangement that is arranged to detect that the marine vessel is docked based on an output of a sensor (such as a proximity sensor) that is arranged to detect that the marine vessel has approached the scheduled docking position (for example, has berthed at a quay, etc.) may be used.

In a preferred embodiment of the present invention, each of the propulsion devices includes a clutch mechanism that is arranged to be switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the transmission of power between the motor and the propeller is cut off. The marine vessel propulsion system further includes a clutch state selection operation unit arranged for an operator to select states of the clutch mechanisms in the plurality of propulsion devices. Further, the clutch state selection operation unit includes a fewer number of operation elements than the total number of the plurality of propulsion devices. Further, the marine vessel propulsion system further includes an association changing unit which is arranged to, when there is a propulsion device that has the transmission of power between the motor and the propeller cut off by the power transmission cutoff unit, change, in accordance with a location of the propulsion device, an association or correspondence of the respective propulsion devices and the operation elements.

By this arrangement, when there is a propulsion device that has the transmission of power between the motor and the propeller cut off by the power transmission cutoff unit, the association of the respective propulsion devices and the operation elements can be changed according to the location of the propulsion device that is cut off. Thus, when there is a propulsion device that has the transmission of power between the motor and the propeller cut off by the power transmission cutoff unit, the clutch state selection operation of the propulsion devices other than the propulsion device that is cut off can be performed readily.

Here, for example, a marine vessel that includes three propulsion devices of starboard-side, central, and port-side and is arranged such that the shift positions of the propulsion devices are selected by two levers (each of which is an example of an operation element) shall be assumed. It shall be assumed that the two levers are disposed in alignment to the right and left facing a stem direction. In a case where the three propulsion devices are in normal states, for example, the lever at the right side facing the stem direction is associated with the starboard-side propulsion device, the lever at the left side facing the stem direction is associated with the port-side propulsion device, and both levers are associated with the central propulsion device. More specifically, when the positions of both levers are at the forward drive position, the shift position of the central outboard motor is controlled to be at the forward drive position. When the positions of both levers are at the reverse drive position, the shift position of the central outboard motor is controlled to be at the reverse drive position. In a case where the combination of the positions of the levers is a combination other than the above, the shift position of the central outboard motor is controlled to be at the neutral position. The shift position of the starboard-side propulsion device is controlled in accordance with the position of the right-side lever. The shift position of the port-side propulsion device is controlled in accordance with the position of the left-side lever.

In a case where the port-side propulsion device enters an abnormal state and the transmission of power between the motor and the propeller thereof is cutoff, the association changing unit, for example, associates the left-side lever with the central propulsion device and associates the right-side lever with the starboard-side propulsion device. In a case where the starboard-side propulsion device enters an abnormal state, the association changing unit, for example, associates the right-side lever with the central propulsion device and associates the left-side lever with the port-side propulsion device. In a case where the central propulsion device enters an abnormal state, the association changing unit does not change the association of the propulsion devices and the levers. The association changing unit is preferably arranged such that the change of association of the propulsion devices and the levers is performed when all levers are at the neutral position. This is to prevent sudden change of behavior of the marine vessel due to change of the association of the propulsion devices and the levers during travel.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a unit arranged to control a propulsion device, for which an abnormality is detected, such that the motor of the propulsion device is put in a driving-stopped state at the same time or after the transmission of power between the motor and the propeller of the propulsion device is cut off by the power transmission cutoff unit.

By this arrangement, a propulsion device, for which an abnormality is detected, is controlled so that the motor of the propulsion device is put in the driving-stopped state at the same time or after the transmission of power between the motor and the propeller of the propulsion device is cut off. Thus, even if the propulsion device, for which an abnormality is detected, is in a driving state when the transmission of power between the motor and the propeller of the propulsion device is cut off, the driving by the motor can be stopped reliably.

In a preferred embodiment of the present invention, each of the propulsion devices includes a clutch mechanism that is arranged to be switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the transmission of power between the motor and the propeller is cut off. The marine vessel propulsion system further includes a stopped state detection unit arranged to detect stopped states of the motors of the respective propulsion devices, a clutch state detection unit arranged to detect, when the stopped state detection unit detects the stopped state of the motor of any of the propulsion devices, the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, and an ignition and injection control unit arranged to cut, when the clutch state detection unit detects the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, an ignition and an injection of the motor.

By this arrangement, if the clutch of the propulsion device is in the transmitting state when the motor is in the stopped state, the ignition and the injection of the motor are cut. The starting of the motor by entrained rotation can thereby be avoided. The stopping of the motor and the transmitting state of the clutch can be detected even if entrained rotation is not actually occurring. The ignition and the injection of the motor can thus be cut before entrained rotation is detected and the starting of the motor by entrained rotation can thus be avoided.

The stopped state detection unit may include a unit arranged to detect that a rotational speed of the motor is less than a predetermined value. The stopped state detection unit may also include a unit arranged to detect that a stop switch for stopping the motor is operated.

In a preferred embodiment of the present invention, the power transmission cutoff unit is arranged to cut off the transmission of power between the motor and the propeller of a propulsion device for which the stopped state of the motor is detected when the clutch state detection unit detects that the clutch mechanism in the propulsion device for which the stopped state of the motor is detected is in the transmitting state.

By this arrangement, as long as the motor is in the stopped state and the clutch is in the transmitting state, the transmission of power between the motor and the propeller is cut off even if entrained rotation is actually not occurring. The occurrence of entrained rotation can thereby be prevented.

A preferred embodiment of the present invention provides a marine vessel propulsion system including a plurality of propulsion devices, each in turn including a motor, a propeller rotated by the motor. The system further includes a clutch mechanism that is arranged to be switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the transmission of power between the motor and the propeller is cut off. The marine vessel propulsion system further includes a common electric power supply switch arranged to be operated by an operator to turn on and off electric power supplies of the plurality of propulsion devices all at once, an electric power supply control unit arranged to put the electric power supplies of the respective propulsion devices in an on state all at once when the common electric power supply switch is turned on and to put the electric power supplies of the respective propulsion devices in an off state all at once when the common electric power supply switch is turned off, a stopped state detection unit arranged to detect stopped states of the motors of the respective propulsion devices, a clutch state detection unit arranged to detect, when the stopped state detection unit detects the stopped state of the motor of any of the propulsion devices, the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, an ignition and injection control unit arranged to cut, when the clutch state detection unit detects the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, an ignition and an injection of the motor, and a power transmission cutoff unit that is arranged to cut off the transmission of power between the motor and the propeller of a propulsion device for which the stopped state of the motor is detected when the clutch state detection unit detects that the clutch mechanism in the propulsion device for which the stopped state of the motor is detected is in the transmitting state.

By this arrangement, when it is detected that the motor is in the stopped state and the clutch is in the transmitting state, the ignition and the injection of the motor are cut and further, the power transmission between the motor and the propeller is cut off. Entrained rotation can thereby be prevented and the starting of the motor due to entrained rotation can be avoided.

In a preferred embodiment of the present invention, the ignition and injection control unit is arranged and programmed such that after cutting the ignition and the injection, the cutting of the ignition and the injection is maintained until the common electric power supply switch is turned off.

If the clutch mechanism is in the cutoff state, there is no apprehension of starting of the motor due to entrained rotation even if the motor is in the stopped state. However, if the clutch mechanism is put in the transmitting state again thereafter, the motor may start due to entrained rotation. It is thus wasteful to start and stop the control of cutting the ignition and the injection according to the detection results of the stopped state of the motor and the transmitting state of the clutch. This waste of control can be avoided by maintaining the cutting of the ignition and the injection until the common electric power supply switch is turned off.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes start switches that are arranged to be operated by an operator to start the motors of the respective propulsion devices. The ignition and injection control unit is arranged such that after cutting the ignition and the injection, the cutting of the ignition and the injection is maintained until the start switch corresponding to the propulsion device for which the stopped state of the motor is detected is operated.

Waste of control can be avoided by this arrangement as well. That is, there is a high possibility that starting of the motor before input of a motor start command is not intended by the user. Waste of control can thus be avoided by cutting the ignition and the injection until the start switch is operated. When the start switch is operated, the cutting of the ignition and the injection is cancelled, and the starting of the motor can be performed in accordance with the intention of the user without any problem.

Also, a preferred embodiment of the present invention provides a marine vessel propulsion system including a plurality of propulsion devices, each in turn including a motor, a propeller rotated by the motor, and a clutch mechanism that is arranged to be switched between a transmitting state, in which power is transmitted between the motor and the propeller, and a cutoff state, in which the transmission of power between the motor and the propeller is cut off. The marine vessel propulsion system further includes a common electric power supply switch arranged to be operated by an operator to turn on and off electric power supplies of the plurality of propulsion devices all at once, an electric power supply control unit putting the electric power supplies of the respective propulsion devices in an on state all at once when the common electric power supply switch is turned on and putting the electric power supplies of the respective propulsion devices in an off state all at once when the common electric power supply switch is turned off, a stopped state detection unit arranged to detect stopped states of the motors of the respective propulsion devices, a clutch state detection unit arranged to detect, when the stopped state detection unit detects the stopped state of the motor of any of the propulsion devices, the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, and an ignition and injection control unit arranged to cut, when the clutch state detection unit detects the transmitting state of the clutch mechanism in the propulsion device for which the stopped state of the motor is detected, the ignition and injection of the motor.

By this arrangement, when it is detected that the motor is in the stopped state and the clutch is in the transmitting state, the ignition and the injection of the motor are cut and further, the power transmission between the motor and the propeller is cut off. Thereby, the starting of the motor due to entrained rotation can be avoided.

In a preferred embodiment of the present invention, the ignition and injection control unit is arranged such that after cutting the ignition and the injection, the cutting of the ignition and the injection is maintained until the common electric power supply switch is turned off. If the clutch mechanism is in the cutoff state, there is no apprehension of starting of the motor due to entrained rotation even if the motor is in the stopped state. However, if the clutch mechanism is put in the transmitting state again thereafter, the motor may start due to entrained rotation. It is thus wasteful to start and stop the control of cutting the ignition and injection according to the detection results of the stopped state of the motor and the transmitting state of the clutch. This waste of control can be avoided by maintaining the cutting of the ignition and the injection until the common electric power supply switch is turned off.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes start switches that are arranged to be operated by an operator to start the motors of the respective propulsion devices. The ignition and injection control unit is arranged such that after cutting the ignition and the injection, the cutting of the ignition and the injection is maintained until the start switch corresponding to the propulsion device for which the stopped state of the motor is detected is operated. Waste of control can be avoided by this arrangement as well. That is, there is a high possibility that starting of the motor before input of a motor start command is not intended by the user. Waste of control can thus be avoided by cutting the ignition and the injection until the start switch is operated. When the start switch is operated, the cutting of the ignition and the injection is cancelled, and the starting of the motor can be performed in accordance with the intention of the user without any problem.

Meanwhile, in a case where a single, common electric power supply switch is provided for a plurality of propulsion devices (for example, outboard motors), if, for example, a fault occurs in one propulsion device, the electric power supply of just the faulty propulsion device cannot be cut off. Consumption of electric power thus becomes a problem. That is, when the electric power supply is turned on with the motor (for example, an engine) being in a state of not starting due to a fault, the electric power of the corresponding battery is only consumed and not recharged and eventually the battery may run out. Obviously, there is also a problem in terms of energy saving performance. Also, when a fault (for example, short-circuiting of an electric power supply system, etc.) that ordinarily requires the turning off of the power supply occurs in one propulsion device, the electric power supply of just the faulty propulsion device cannot be turned off. If the electric power supplies of all of the propulsion devices are turned off, a propulsive force for the marine vessel cannot be obtained. Traveling must thus be continued with the power supply of the faulty propulsion device remaining on.

Thus, a preferred embodiment of the present invention provides a marine vessel propulsion system that resolves the above issue. This system includes a plurality of propulsion devices, each in turn including a motor and a motor control unit, a common electric power supply switch arranged to be operated by an operator to turn on and off the plurality of propulsion devices all at once, a plurality of electric power supply off command input units for turning off electric power supplies of the respective propulsion devices individually, and an electric power supply control unit programmed to perform on/off control of the electric power supplies of the respective propulsion devices based on inputs from the common electric power supply switch and the respective electric power supply off command input units. The electric power supply control unit includes an all electric power supply on unit that is arranged to turn on the electric power supplies of the respective propulsion devices all at once when the common electric power supply switch is turned on, an all electric power supply off unit that is arranged to turn off the electric power supplies of the respective propulsion devices all at once when the common electric power supply switch is turned off, and a first individual electric power supply off unit, which is arranged, when the electric power supply off command is input by any of the electric power supply off command input units with the common electric power supply switch being in the on state, individually turn off the electric power supply of the propulsion device corresponding to the electric power supply off command input unit.

By this arrangement, by operating the common electric power supply switch (which may be a single common electric power supply switch), the electric power supplies of the plurality of propulsion devices can be turned on all at once or turned off all at once. Thus, in a case where the common electric power supply switch is arranged from a key switch, consolidation of a main key for turning on and off the electric power supplies of the plurality of propulsion devices is enabled. When the electric power supply off command is input by any of the electric power supply off command input units with the common electric power supply switch being in the on state, the electric power supply of the propulsion device corresponding to the electric power supply off command input unit is turned off individually. A state of the propulsion device with which the electric power supply is turned off individually in this manner may be referred to as an “individual electric power supply off mode.”

Thus, for example, when a fault occurs in one propulsion device, the electric power supply of just the faulty propulsion device can be turned off. The power supply of the propulsion device, with which the motor (for example, an engine) cannot be started due to a fault, etc., can thus be turned off individually. Wasteful consumption of electric power can thus be minimized. Also, in a system in which a battery that is used as the electric power supply is recharged by operation of the motor, the running out of the battery can be reduced or prevented. Also, traveling of the marine vessel is not disrupted because the electric power supply of the propulsion device, for which the fault, etc., has occurred, can be put in the off state and the electric power supplies of the other normal propulsion devices can be put in the on state.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a plurality of start/stop switches arranged to be operated by an operator for starting and stopping the motors of the respective propulsion devices individually, and an operation judgment unit judging an operation of each start/stop switch as being a first operation for inputting a start/stop command or a second operation that is a specific operation differing from the first operation and is for inputting an electric power supply off command. The plurality of start/stop switches serve in common as the plurality of electric power supply command input units, and the first individual electric power supply off unit is arranged to respond to the judgment by the operation judgment unit that the second operation is performed.

With this arrangement, by performing the second operation on the start/stop switches for starting and stopping the motors of the respective propulsion devices individually, the electric power supplies of the propulsion devices corresponding to the start/stop switches can be turned off individually. Thus, by this arrangement, a special switch for turning off the electric power supplies individually does not have to be provided.

In a preferred embodiment of the present invention, the first operation of each start/stop switch is a short pressing operation of the start/stop switch, and the second operation of each start/stop switch is a long pressing operation of the start/stop switch. With this arrangement, by performing the long pressing operation of a start/stop switch, the electric power supply of the propulsion device corresponding to the start/stop switch can be turned off individually.

In a preferred embodiment of the present invention, the electric power supply control unit further includes a first individual electric power supply on unit, which is arranged to, when the start/stop switch, corresponding to a propulsion device having its electric power supply in the off state, is operated with the common electric power supply switch being in the on state, turn on the electric power supply of the propulsion device individually.

By this arrangement, when the start/stop switch, corresponding to a propulsion device having its electric power supply in the off state (individual electric power supply off mode), is operated with the common electric power supply switch being in the on state, the electric power supply of the propulsion device is turned on. The electric power supply of the propulsion device that is in the individual electric power supply off mode can thus be turned on by a simple operation.

The first individual electric power supply on unit may be arranged to turn on the electric power supply of the propulsion device individually and at the same time generate a start command for starting the motor of the propulsion device.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a plurality of individual electric power supply switches arranged to be operated by an operator to turn on and off the electric power supplies of the respective propulsion devices individually, and the electric power supply control unit further includes a second individual electric power supply on unit, which is arranged to, when an on operation of any of the individual electric power supply switches is performed, put the electric power supply of the propulsion device corresponding to the individual electric power supply switch in the on state individually, and a second individual electric power supply off unit, which is arranged to, when an off operation of any of the individual electric power supply switches is performed, put the electric power supply of the propulsion device corresponding to the individual electric power supply switch in the off state individually.

By this arrangement, the electric power supply of each propulsion devices can be turned on and off individually by operation of the individual electric power supply switch. In this case, the individual electric power supply switch is provided dedicatedly for turning on and off the electric power supply of the propulsion device individually, and operation thereof can be made simple.

Also, as mentioned above, there is a case where the first individual electric power supply on unit turns on the electric power supply of a propulsion device individually and generates the start command for starting the motor of the propulsion device. In this case, when the first individual electric power supply on unit operates, the electric power supply of a propulsion device in the individual electric power supply off mode is turned on and, at the same time, the motor thereof is started. Thus, by providing the individual electric power supply switch, the power supply of a propulsion device in the individual electric power supply off mode can be put in the on state without starting the motor of the propulsion device.

In a preferred embodiment of the present invention, the marine vessel propulsion system further includes a display unit arranged to display on/off states of the electric power supplies of the respective propulsion devices. By this arrangement, when there is a propulsion device that has its electric power supply turned off even though the common electric power supply switch is on (a propulsion device in the individual electric power supply off mode), the user can recognize this readily.

A preferred embodiment of the present invention provides a marine vessel including a hull and a marine vessel propulsion system including the features described above.

Other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a perspective view for explaining an arrangement of a marine vessel according to a preferred embodiment of the present invention. The marine vessel1includes a hull2and outboard motors3as propulsion devices. A plurality (for example, three, in the preferred embodiment) of the outboard motors3are included. The outboard motors3are attached in alignment along a stern of the hull2. When the three outboard motors are to be distinguished, that disposed at a starboard-side shall be referred to as the “starboard-side outboard motor3S,” that disposed at a center shall be referred to as the “central outboard motor3C,” and that disposed at a port-side shall be referred to as the “port-side outboard motor3P.” Each of the outboard motors3includes an engine (internal combustion engine) and a propeller (screw) and generates a propulsive force by the propeller being rotated by a driving force of the engine.

A marine vessel maneuvering compartment5is provided at a front portion (stern side) of the hull2. The marine vessel maneuvering compartment5includes a steering operation apparatus6, remote controllers7, an operation panel8, gauges9, and a remote controller ECU (electronic control unit)10.

The steering operation apparatus6includes a steering wheel6athat is rotatingly operated by a marine vessel operator. The operation of the steering wheel6ais mechanically transmitted by a cable (not illustrated) to a steering mechanism (not illustrated) provided at the stern. The steering mechanism is arranged to couplingly move the three outboard motors3and change their directions. A direction of the propulsive force is thereby changed and a heading direction of the marine vessel1can be changed accordingly. Obviously, a power steering apparatus including a sensor that detects an operation angle of the steering wheel6aand an actuator that is driven in accordance with the operation angle detected by the sensor may be adopted. In this case, there is no mechanical link between the steering wheel6aand the steering mechanism, and the actuator is driven by a control signal that is in accordance with the steering operation so that the outboard motors3are steered by a driving force of the actuator.

In the present preferred embodiment, two remote controllers7are preferably included, for example. The two remote controllers7are disposed in alignment to the right and left facing a stem direction, and each includes a lever71that can be inclined forward and in reverse. When the two remote controllers are to be distinguished, that disposed at the right side facing the stem direction shall be referred to as the “starboard-side remote controller7S” and that disposed at the left side facing the stem direction shall be referred to as the “port-side remote controller7P.” When the two levers71are to be distinguished, that corresponding to the starboard-side remote controller7S shall be referred to as the “starboard-side lever71S” and corresponding to the port-side remote controller7P shall be referred to as the “port-side lever71P.”

Inclination positions of the respective levers71S and71P are respectively detected by lever position sensors11S and11P that may be potentiometers, etc. (seeFIG. 4). The lever position sensor11S corresponds to the starboard-side lever71S, and the lever position sensor11P corresponds to the port-side lever71P.

Three gauges9are provided in correspondence to the three outboard motors3. These gauges9are arranged to display states of the corresponding outboard motors3. More specifically, each gauge9displays a rotational speed of the engine and other necessary information of the corresponding outboard motor3.

As shown inFIG. 2, the operation panel8includes a single key switch81arranged to be operated by an operator for turning on and off electric power supplies of the three outboard motors3all at once, and three start/stop switches82S,82C, and82P, which can be operated individually. The operation panel8further includes lamps83S,83C, and83P arranged to display on/off states of the electric power supplies of the three outboard motors3.

The key switch81is arranged to be operated by a user (operator) to turn on and off the electric power supplies of the three outboard motors3all at once and to start the engines of the three outboard motors3all at once. Specifically, by the user's operating the key switch81from an off position to an on position, the electric power supplies of the three outboard motors3are turned on all at once. When the user further operates the key switch81from the on position to a start position, the three outboard motors3are started all at once. Also, by the user's operating the key switch81from the on position to the off position, the electric power supplies of the three outboard motors3are put in the off states all at once.

Three each of the start/stop switches and the lamps are provided in correspondence to the three outboard motors3. The start/stop switch82S and the lamp83S provided in the vicinity thereof correspond to the starboard-side outboard motor3S. The start/stop switch82C and the lamp83C provided in the vicinity thereof correspond to the central outboard motor3C. The start/stop switch82P and the lamp83P provided in the vicinity thereof correspond to the port-side outboard motor3P.

Operation methods of each start/stop switch82include a first operation and a second operation. In the present preferred embodiment, the first operation is a “short pressing operation,” and the second operation is a “long pressing operation.” The “long pressing operation” is a continuous operation performed for no less than a predetermined fixed time.

By performing short pressing operations of the start/stop switches82individually, the engines of the three outboard motors3can be started and stopped individually. By performing the long pressing operation of a start/stop switch82individually with the key switch81being at the on position, the electric power supply of the outboard motor3corresponding to the start/stop switch82can be turned off individually.

FIG. 3is a schematic side view for explaining an arrangement example in common to the three outboard motors3.

Each outboard motor3includes a propulsion unit60, and an attachment mechanism61arranged to attach the propulsion unit60to the hull2. The attachment mechanism61includes a clamp bracket62arranged to be detachably fixed to a transom of the hull2, and a swivel bracket64coupled to the clamp bracket62in a manner enabling pivoting about a tilt shaft63as a horizontal pivot axis. The propulsion unit60is attached to the swivel bracket64in a manner enabling pivoting about a steering shaft65. Thus, a steering angle (a direction angle defined by the direction of the propulsive force with respect to a centerline of the hull2) can be changed by pivoting the propulsion unit60about the steering shaft65. Further, a trim angle of the propulsion unit60can be changed by pivoting the swivel bracket64about the tilt shaft63. The trim angle is an angle of attachment of the outboard motor3with respect to the hull2.

A housing of the propulsion unit60includes an engine cover66, an upper case67, and a lower case68. Inside the engine cover66, the engine69as a drive source is installed with an axis of a crankshaft thereof extending vertically. A driveshaft91is coupled to a lower end of the crankshaft of the engine69, and vertically extends through the upper case67into the lower case68.

A propeller90, which is a propulsive force generating member, is rotatably attached to a lower rear portion of the lower case68. A propeller shaft92, which is a rotation shaft of the propeller90, extends horizontally in the lower case68. The rotation of the driveshaft91is transmitted to the propeller shaft92via a shift mechanism93as a clutch mechanism.

The shift mechanism93includes a drive gear93a, a forward drive gear93b, a reverse drive gear93c, and a dog clutch93d. The drive gear93ais arranged as a beveled gear fixed to a lower end of the driveshaft91. The forward drive gear93bis arranged as a beveled gear rotatably disposed on the propeller shaft92. The reverse drive gear93cis likewise arranged as a beveled gear rotatably disposed on the propeller shaft92. The dog clutch93dis disposed between the forward drive gear93band the reverse drive gear93c.

The forward drive gear93bis meshed with the drive gear93afrom a forward side, and the reverse drive gear93cis meshed with the drive gear93afrom a reverse side. Therefore, the forward drive gear93band the reverse drive gear93crotate in mutually opposite directions.

The dog clutch93dis in spline engagement with the propeller shaft92. That is, the dog clutch93dis axially slidable with respect to the propeller shaft92, but is not rotatable relative to the propeller shaft92, and thus rotates together with the propeller shaft92.

The dog clutch93dis slid along the propeller shaft92by receiving a force of a shift rod94by axial pivoting of the shift rod94, which extends vertically and parallel to the driveshaft91. The dog clutch93dis thereby controlled to be at a shift position among a forward drive position at which it is engaged with the forward drive gear93b, a reverse drive position at which it is engaged with the reverse drive gear93c, and a neutral position at which it is not engaged with either the forward drive gear93bor the reverse drive gear93c.

When the dog clutch93dis at the forward drive position, the rotation of the forward drive gear93bis transmitted to the propeller shaft92via the dog clutch93d. The propeller90is thereby rotated in one direction (forward drive direction) to generate a propulsive force in a direction of moving the hull2forward. On the other hand, when the dog clutch93dis at the reverse drive position, the rotation of the reverse drive gear93cis transmitted to the propeller shaft92via the dog clutch93d. The reverse drive gear93cis rotated in a direction opposite to that of the forward drive gear93b, and the propeller90is thus rotated in an opposite direction (in a reverse drive direction) to generate a propulsive force in a direction of moving the hull2in reverse. When the dog clutch93dis in the neutral position, the rotation of the driveshaft91is not transmitted to the propeller shaft92. That is, a driving force transmission path between the engine69and the propeller90is cut off, so that no propulsive force is generated in either of the forward and reverse drive directions.

In relation to the engine69, a starter motor45is disposed and is arranged to start the engine69. The starter motor45is controlled by an outboard motor ECU30. A throttle actuator48is also provided and is arranged to actuate a throttle valve52of the engine69to change a throttle opening degree and thereby change an intake air amount of the engine69. The throttle actuator48may include an electric motor. Operation of the throttle actuator48is controlled by the outboard motor ECU30. An engine speed sensor43arranged to detect a rotation of the crankshaft is provided to detect a rotational speed of the engine69.

In relation to the shift rod94, a shift actuator49arranged to change the shift position of the dog clutch93dis provided. The shift actuator49includes, for example, an electric motor, and its operation is controlled by the outboard motor ECU30.

FIG. 4is a diagram for explaining an electrical arrangement of principal portions of the marine vessel1.

The operation panel8and the lever position sensors11P and11S are connected to the remote controller ECU10. The remote controller ECU10includes a computer (microcomputer). Although in the present preferred embodiment, three remote controller ECUs10S,10C, and10P are provided in correspondence to the three outboard motors3S,3C, and3P, inFIG. 4, these are indicated collectively as “remote controller ECU10.” The three remote controllers10S,10C, and10P exchange information mutually via a communication line.

The remote controller ECU10is connected to a bus20that defines an inboard LAN (local area network). The gauges9P,9C, and9S are connected to the bus20. Also, a speed sensor12arranged to detect a speed of the marine vessel is connected to the bus20.

The outboard motors3S,3C, and3P respectively include outboard motor ECUs30P,30C, and30S. The outboard motor ECU30P corresponds to the port-side outboard motor3P, the outboard motor ECU30C corresponds to the central outboard motor3C, and the outboard motor ECU30S corresponds to the starboard-side outboard motor3S. The outboard motor ECUs30S,30C, and30P are connected to the bus20. The outboard motor ECUs30S,30C, and30P are practically the same in internal arrangement, and shall be referred to below as “outboard motor ECUs30” when these are to be referred to collectively.

Each outboard motor ECU30includes a computer (microcomputer). A temperature sensor41, a hydraulic pressure sensor42, the engine speed sensor43, a shift position sensor44, the starter motor45, an ignition coil46, an injector47, the throttle actuator48, the shift actuator49, a fuel pump50, an oil pump51, etc., are connected to the outboard motor ECU30.

The starter motor45is a device arranged to perform cranking of the engine. The injector47is a device that is arranged to inject fuel into an air intake path of the engine. The throttle actuator48is a device that is arranged to actuate the throttle valve52to adjust the amount of air supplied to the air intake path of the engine. The ignition coil46is arranged to raise a voltage applied to a spark plug (not shown). The spark plug is a device that is arranged to perform discharge inside a combustion chamber of the engine to ignite a mixed gas inside the combustion chamber. The shift actuator49is a device that is arranged to drive the shift mechanism93of the outboard motor. The fuel pump50is a device that is arranged to pump out fuel from a fuel tank (not shown) to supply the fuel to the injector47. The oil pump51is a device that is arranged to circulate engine oil inside the engine.

The temperature sensor41is arranged to detect a temperature of cooling water of the engine. The hydraulic pressure sensor42is arranged to detect a pressure of the engine oil. The engine speed sensor43is arranged to detect the rotational speed of the engine. The shift position sensor44is arranged to detect the shift position of the shift mechanism93(shift position of the outboard motor).

The computer of the remote controller ECU10executes a program to perform functions as a plurality of function processing portions. The function processing portions include an electric power supply control unit, a start/stop control unit, an association changing unit, and a target value computing unit.

Functions of the remote controller ECU10as the electric power supply control unit include performing of on/off control of the electric power supplies of the respective outboard motors3based on operation signals from the respective switches on the operation panel8. Functions of the remote controller ECU10as the start/stop control unit include performing of start/stop control of the engines of the respective outboard motors3based on operation signals from the respective switches on the operation panel8. Functions of the remote controller ECU10as the association changing unit include changing of association or correspondence of the levers71and the outboard motors3. Functions of the remote controller ECU10as the target value computing unit include computing of target shift positions and target engine speeds of the respective outboard motors3based on the association of the levers71and the outboard motors3as well as outputs of the lever position sensors11P and11S. These functions shall now be described in detail.

Details of the functions of the remote controller ECU10as the electric power supply control unit are as follows. When the key switch81is operated from the off position to the on position, the remote controller ECU10turns on the electric power supplies of all outboard motor ECUs30all at once and turns on all lamps83. Also, when the key switch81is operated from the on position to the off position, the remote controller ECU10turns off the electric power supplies of all outboard motors3all at once and turn off all lamps83.

Details of the functions of the remote controller ECU10as the start/stop control unit are as follows. When the key switch81is operated from the on position to the start position, the remote controller ECU10outputs an engine start command to each outboard motor ECU30under a condition that starting allowing conditions are met. The starting allowing conditions may include that the target shift position of the outboard motor3is the neutral position and that the actual shift position of the outboard motor3is the neutral position. Information on the actual shift position of each outboard motor3is sent from each outboard motor ECU30to the remote controller ECU10via the bus20.

When in a case where the key switch81is at the on position, a start/stop switch82is depressed, the remote controller ECU10judges whether the engine of the outboard motor3corresponding to the start/stop switch82is stopped or is running (in operation). If the engine of the corresponding outboard motor3is stopped, the remote controller ECU10outputs the engine start command to the outboard motor ECU30under the condition that the starting allowing conditions are met. If the engine of the corresponding outboard motor3is running, the remote controller ECU10outputs an engine stop command to the outboard motor ECU30.

Upon receiving the engine start command, the outboard motor ECU30performs an engine starting process. In the engine starting process, the outboard motor ECU30drives the starter motor45, the ignition coil46, and the injector47to perform ignition control and fuel injection control to start the engine. On the other hand, upon receiving the engine stop command, the outboard motor ECU30performs the engine stopping process. In the engine stopping process, the outboard motor ECU30stops the fuel injection by the injector47and stops the ignition operation by the spark plug and thereby stops the engine.

Details of the functions of the remote controller ECU10as the association changing unit shall now be described. In the present preferred embodiment, the remote controller ECU10has three modes in relation to the association of the two levers71and the three outboard motors3as shown inFIG. 5A,FIG. 5B, andFIG. 5C. These are a basic mode, a first modified mode, and a second modified mode.

In the basic mode, the port-side lever71P is associated with the port-side outboard motor3P, the starboard-side lever71S is associated with the starboard-side outboard motor3S, and both levers71S and71P are associated with the central outboard motor3C as shown inFIG. 5A.

In the first modified mode, the port-side lever71P is associated with the central outboard motor3C and the starboard-side lever71S is associated with the starboard-side outboard motor3S as shown inFIG. 5B. In this case, neither of the levers71is associated with the port-side outboard motor3P.

In the second modified mode, the port-side lever71P is associated with the port-side outboard motor3P and the starboard-side lever71S is associated with the central outboard motor3C as shown inFIG. 5C. In this case, neither of the levers71is associated with the starboard-side outboard motor3S.

The functions of the remote controller ECU10as the association changing unit include a process (association mode switching process) for switching the mode of lever/outboard motor association (hereinafter referred to as the “association mode”) among the three modes described above. Details of this process shall be described later.

Details of the functions of the remote controller ECU10as the target value computing unit shall now be described. The remote controller ECU10computes the target shift positions and the target engine speeds for the respective outboard motors3based on the presently set association mode and the output signals of the lever position sensors11S and11P, and transmits these target values to the corresponding outboard motor ECUs30. Each outboard motor ECU30controls the shift position and the engine speed of the outboard motor based on the target shift position and the target engine speed transmitted from the remote controller ECU10. Specifically, the outboard motor ECU30preferably controls the shift actuator49so that the shift position of the outboard motor3is at the target shift position and controls the throttle actuator48so that the engine speed is the target engine speed. Such control shall be referred to as “lever-following shift control.” The “lever-following shift control” performed at the outboard motor ECU30shall be described in detail below.

When the association mode is the basic mode, the shift positions of the respective outboard motors3are controlled as follows. When the port-side lever71P is inclined forward by no less than a predetermined amount from a predetermined neutral position, the shift position of the port-side outboard motor3P is controlled to be at the forward drive position and a propulsive force in the forward drive direction is generated from the outboard motor3P. The target engine speed is set at an idling engine speed up to the inclination position of the predetermined amount (forward drive shift-in position). When the port-side lever71P is inclined forward beyond the forward drive shift-in position, the target engine speed is set to be greater the greater the lever inclination amount. When the port-side lever71P is inclined in reverse by no less than a predetermined amount from the neutral position, the shift position of the port-side outboard motor3P is controlled to be at the reverse drive position and a propulsive force in the reverse drive direction is generated from the outboard motor3P. The target engine speed is set at the idling engine speed up to the inclination position of the predetermined amount (reverse drive shift-in position). When the port-side lever71P is inclined in reverse beyond the reverse drive shift-in position, the target engine speed is set to be greater the greater the lever inclination amount. When the port-side lever71P is at the neutral position (or to be more accurate, between the forward drive shift-in position and the reverse drive shift-in position), the shift position of the port-side outboard motor3P is set at the neutral position and the outboard motor3P does not generate a propulsive force.

When the starboard-side lever71S is operated, the shift position and the engine speed of the starboard-side outboard motor3S are controlled in the same manner as in the above-described control of the shift position and the engine speed of the port-side outboard motor3P performed when the port-side lever71P is operated.

Further, the shift position of the central outboard motor3C is controlled as follows according to the operations of both levers71P and71S. That is, when the levers71P and71S are both inclined forward to no less than the forward drive shift-in positions from the neutral positions, the shift position of the central outboard motor3C is controlled to be at the forward drive position and a propulsive force in the forward drive direction is generated from the central outboard motor3C. When the levers71P and71S are both inclined in reverse to no less than the reverse drive shift-in positions from the neutral positions, the shift position of the central outboard motor3C is controlled to be at the reverse drive position and a propulsive force in the reverse drive direction is generated from the central outboard motor3C. The target engine speed is set to the idling engine speed if the inclination positions of both levers71P and71S are between the forward drive shift-in positions and the reverse drive shift-in positions. When the lever inclination positions are outside the ranges between the forward and reverse drive shift-in positions, the target engine speed is set according to the inclination amounts of both levers71P and71S. If at least one of either of the levers71P and71S is at the neutral position (or more accurately, a position between the forward drive shift-in position and the reverse drive shift-in position), the shift position of the central outboard motor3C is controlled to be at the neutral position. The shift position of the central outboard motor3C is also controlled to be at the neutral position when one of the levers is inclined forward from the neutral position (for example, inclined forward relative to the forward drive shift-in position) and the other lever is inclined in reverse from the neutral position (for example, inclined in reverse relative to the reverse drive shift-in position).

When the association mode is set to the first modified mode, the shift position and the engine speed of the starboard-side outboard motor3S are controlled according to the operation position of the starboard-side lever71S in the same manner as in the basic mode. The shift position of the central outboard motor3C is controlled in accordance with the operation position of the port-side lever71P. That is, when the port-side lever71P is inclined forward to no less than the forward drive shift-in position from the neutral position, the shift position of the central outboard motor3C is controlled to be at the forward drive position. When the port-side lever71P is inclined in reverse to no less than the reverse drive shift-in position from the neutral position, the shift position of the central outboard motor3C is controlled to be at the reverse drive position. When the port-side lever71P is at the neutral position (or more accurately, a position between the forward drive shift-in position and the reverse drive shift-in position), the shift position of the central outboard motor3C is controlled to be at the neutral position. When the inclination position of the port-side lever71P is in the range between the forward drive shift-in position and the reverse drive shift-in position, the target engine speed is set at the idling engine speed, and outside this range, a target engine speed is set in accordance with the lever inclination amount. In the first modified mode, the shift position and the engine rotation speed of the port-side outboard motor3P are not controlled according to operations of the levers71.

When the association mode is set at the second modified mode, the shift position and the engine speed of the port-side outboard motor3P are controlled according to the operation position of the port-side lever71P in the same manner as in the basic mode. The shift position of the central outboard motor3C is controlled in accordance with the operation position of the starboard-side lever71S. That is, when the starboard-side lever71S is inclined forward to no less than the forward drive shift-in position from the neutral position, the shift position of the central outboard motor3C is controlled to be at the forward drive position. When the starboard-side lever71S is inclined in reverse to no less than the reverse drive shift-in position from the neutral position, the shift position of the central outboard motor3C is controlled to be at the reverse drive position. When the starboard-side lever71S is at the neutral position (or more accurately, a position between the forward drive shift-in position and the reverse drive shift-in position), the shift position of the central outboard motor3C is controlled to be at the neutral position. When the inclination position of the starboard-side lever71S is in the range between the forward drive shift-in position and the reverse drive shift-in position, the target engine speed is set at the idling engine speed, and outside this range, a target engine speed is set in accordance with the lever inclination amount. In the second modified mode, the shift position and the engine rotation speed of the starboard-side outboard motor3S are not controlled according to operations of the levers71.

FIG. 6AtoFIG. 6Fare diagrams for explaining relationships between the respective lever positions and movements of the hull when the association mode is set to the basic mode.

When, as shown inFIG. 6A, the port-side lever71P is inclined forward (to an F side) beyond the forward drive shift-in position and the starboard-side lever71S is at the neutral position, the shift position of the port-side outboard motor3P is set at the forward drive position and the shift positions of the other outboard motors3C and3S are set at the neutral positions. The hull2thus receives only the forward drive direction propulsive force of the port-side outboard motor3P and thus turns in the starboard direction.

When, as shown inFIG. 6B, the starboard-side lever71S is inclined forward (to the F side) beyond the forward drive shift-in position and the port-side lever71P is at the neutral position, the shift position of the starboard-side outboard motor3S is set at the forward drive position and the shift positions of the other outboard motors3P and3C are set at the neutral positions. The hull2thus receives only the forward drive direction propulsive force of the starboard-side outboard motor3S and thus turns in the port direction.

When, as shown inFIG. 6C, both levers71S and71P are inclined forward (to the F side) beyond the forward drive shift-in positions, the shift positions of all three outboard motors3are set at the forward drive positions. The hull2thus receives the forward drive direction propulsive forces of all three outboard motors3and thus moves forward.

When, as shown inFIG. 6D, both levers71S and7P are inclined in reverse (to an R side) beyond the reverse drive shift-in positions, the shift positions of all three outboard motors3are set at the reverse drive positions. The hull2thus receives the reverse drive direction propulsive forces of all three outboard motors3and thus moves in reverse.

FIG. 6Eshows a state where the port-side lever71P is inclined in reverse (to the R side) beyond the reverse drive shift-in position and the starboard-side lever71S is inclined forward (to the F side) beyond the forward drive shift-in position. In this case, the shift position of the port-side outboard motor3P is set at the reverse drive position, the shift position of the starboard-side outboard motor3S is set at the forward drive position, and the shift position of the central outboard motor3C is set at the neutral position. The hull2is thus turned in the port direction by the reverse drive direction propulsive force of the port-side outboard motor3P and the forward drive direction propulsive force of the starboard-side outboard motor3S.

FIG. 6Fshows a state where the port-side lever71P is inclined forward (to the F side) beyond the forward drive shift-in position and the starboard-side lever71S is inclined in reverse (to the R side) beyond the reverse drive shift-in position. In this case, the shift position of the port-side outboard motor3P is set at the forward drive position, the shift position of the starboard-side outboard motor3S is set at the reverse drive position, and the shift position of the central outboard motor3C is set at the neutral position. The hull2is thus turned in the starboard direction by the forward drive direction propulsive force of the port-side outboard motor3P and the reverse drive direction propulsive force of the starboard-side outboard motor3S.

The computer of each outboard motor ECU30executes programs to perform functions as a plurality of function processing units. The function processing units include an engine starting process unit, an engine stopping process unit, and a shift control unit. A function of the outboard motor ECU30as the engine starting process unit is to perform the engine starting process. Functions of the outboard motor ECU30as the engine stopping process unit include the engine stopping process.

Functions of the outboard motor ECU30as the shift control unit include making an entrained rotation judgment at every predetermined time and performing shift control in accordance with the judgment result. In the present preferred embodiment, “entrained rotation” refers to a phenomenon where the crankshaft of the engine of an outboard motor3, which is stopped or should be stopped, rotates upon receiving of a force from water in accompaniment with the traveling of the marine vessel.

FIG. 7is a flowchart of procedures of the shift control process executed by the outboard motor ECU30. This shift control process is performed repeatedly at every predetermined control cycle.

First, the outboard motor ECU30judges a drive state of the starter motor45and stores the judgment result (driven or not driven) in a memory (not illustrated) provided in the outboard motor ECU30(step S1). A predetermined number of previous judgment results, including the presently obtained judgment result of the drive state of the starter motor, are stored as history information in the memory. Also, the outboard motor ECU30acquires the engine speed (information expressing an engine drive state) from the engine speed sensor43and stores it in the memory (step S2). A predetermined number of previous engine speeds, including the presently acquired engine speed, are stored as history information in the memory.

The outboard motor ECU30then makes the entrained rotation judgment based on the history information of the starter motor drive state judgment results and the engine speeds stored in the memory (step S33). Specifically, the outboard motor ECU30judges that entrained rotation is occurring in the engine of the corresponding outboard motor3when one of either of the following conditions (i) and (ii) is met:

(i) From a state in which the rotation of the engine was stopped, the driving shaft (for example, the crankshaft) of the engine has rotated with the starter motor45not being driven.

(ii) Rotation of the driving shaft of the engine does not stop within a fixed time despite the engine stopping process being started on the engine that was in the running state.

If the outboard motor ECU30judges that entrained rotation is not occurring in the corresponding outboard motor3(step S3: NO), it resets a flag F (F=0) (step S4) and thereafter performs the “lever-following shift control” described above (step S5). The present process is then ended.

The flag F is a flag that stores which of the controls among the “lever-following shift control” and a “forced shift control to the neutral position” is being performed on the corresponding outboard motor3. The “forced shift control to the neutral position” is a control by which the shift position of the corresponding outboard motor3is set forcibly to the neutral position regardless of the positions of the levers71.

In an initializing process during starting of the outboard motor ECU30, the flag F is reset (F=0). Three flags F are respectively provided in correspondence to the three outboard motors3. When these are to be distinguished, the flag corresponding to the port-side outboard motor3P shall be indicated as “FP,” the flag corresponding to the starboard-side outboard motor3S shall be indicated as “FS,” and the flag corresponding to the central outboard motor3C shall be indicated as “FC.”

When in step S3, it is judged that entrained rotation is occurring in the engine of the outboard motor3(step S3: YES), the outboard motor ECU30sets the flag F to 1 (F=1) (step S6) and performs the “forced shift control to the neutral position” (step S7). By performing the “forced shift control to the neutral position,” the transmission of power between the engine and the propeller of the corresponding outboard motor3is cut off. When the “forced shift control to the neutral position” is performed, the shift position of the outboard motor3is not switched even when the levers71are operated. That is, during execution of the “forced shift control to the neutral position,” the outboard motor ECU30invalidates the target shift position transmitted from the remote controller ECU10.

At the same time as or after performing the “forced shift control to the neutral position” in step S7, the outboard motor ECU30performs the engine stopping process to stop the driving of the engine of the corresponding outboard motor3(step S8). When it is judged in the step S3that entrained rotation is occurring, there is a possibility for the engine of the corresponding outboard motor3to be started by the cranking due to the entrained rotation. Also, even if the engine of the corresponding outboard motor3is not being driven at the point at which it is judged that entrained rotation is occurring, the engine may start in an interval until the transmission of power between the engine and the propeller is cut off by the “forced shift control to the neutral position” (step S7).

Thus, in the present preferred embodiment, the engine stopping process is performed at the same time as or after performing the “forced shift control to the neutral position” in step S7. In the engine stopping process, the outboard motor ECU30stops the fuel injection by the injector47and stops the ignition operation by the spark plug to stop the engine. Thus, even if the engine is being driven when the transmission of the power between the engine and the propeller is cut off by the “forced shift control to the neutral position,” the engine can be stopped reliably.

In step S8, the outboard motor ECU30may first judge whether or not the engine of the corresponding outboard motor3is being driven and then perform the engine stopping process only when it is judged that the engine is being driven. The judgment of whether or not the engine is being driven is made based, for example, on the engine speed detected by the engine speed sensor43.

During execution of the “forced shift control to the neutral position” in step S7, the outboard motor ECU30notifies this (step S9). Specifically, the outboard motor ECU30displays on the corresponding gauge9that the shift position of the corresponding outboard motor3is forcibly maintained at the neutral position by the “forced shift control to the neutral position.” When the “forced shift control to the neutral position” is being performed, the shift position of the outboard motor3cannot be switched even if the user operates the levers71. The user may thus mistake that a fault is occurring in the remote controller7or the shift mechanism of the outboard motor3. When the “forced shift control to the neutral position” is being performed, this is notified to the user in the present preferred embodiment to prevent such a mistake.

FIGS. 8A-8Dare diagrams for specifically explaining the shift control process executed by the outboard motor ECU30.

Here, a case shall be assumed where a fault occurs in the engine of the central outboard motor3C when all three outboard motors3are generating propulsive forces in the forward drive direction and the hull2is thereby being driven forward as shown inFIG. 8A.

In this case, the user performs an operation (engine stopping operation) for stopping the engine of the central outboard motor3C in which the fault has occurred as shown inFIG. 8B. That is, the user depresses the start/stop switch82C corresponding to the central outboard motor3C.

In response to the engine stopping operation, the outboard motor ECU30C corresponding to the central outboard motor3C performs the engine stopping process. During traveling of the marine vessel, a water stream relative to the propeller of the central outboard motor3C is generated in the vicinity of the propeller. Thus, even if the engine is not generating a driving force, the propeller is rotated by the force received from the water stream. If, at this time, the shift position of the central outboard motor3C is the forward drive position or the reverse drive position, the rotation of the propeller is transmitted to the engine and the crankshaft is thereby rotated. That is, entrained rotation occurs.

If, despite the engine stopping process being started, the engine does not stop within a fixed time, the outboard motor ECU30judges that entrained rotation is occurring in the engine as shown inFIG. 8C. If the shift position during the engine stopping process is the neutral position, the rotation of the engine is stopped. However, if the shift position is changed to the forward drive position or the reverse drive position thereafter, entrained rotation of the engine occurs. Thus, if after the engine is put in the stopped state by the engine stopping process, the engine is put in a rotating state with the starter motor45not being driven, the outboard motor ECU30likewise judges that entrained rotation is occurring in the engine (FIG. 8C). Entrained rotation detection by the outboard motor ECU30C is thus executed.

Even if a fault is not occurring in any of the outboard motors, there is a possibility for the phenomenon of entrained rotation to occur in a case where a specific outboard motor is in a driving-stopped state and its electric power supply is on. For example, even in a state where a fault is not occurring in any of the outboard motors, the user may stop a portion of the outboard motors to perform trolling travel at low speed or to reduce the number of outboard motors in the running state for the purpose of reducing fuel consumption when a remaining fuel amount is low. Entrained rotation may occur in such a case as well. As in the above described case of a fault, the outboard motor ECU30judges that entrained rotation is occurring in such a case as well.

Upon detecting the entrained rotation, the outboard motor ECU30C executes the “forced shift control to the neutral position,” and controls the shift position of the engine of the central outboard motor3C to be at the neutral position as shown inFIG. 8D. That is, the shift position of the central outboard motor3C is maintained at the neutral position regardless of the lever position. Thus, when the entrained rotation of the engine is detected, the shift position of the outboard motor that includes the engine is forcibly set at the neutral position. The inability to stop an engine that should be stopped or the starting of an engine in a stopped state can be prevented thereby.

If, in the state where the “forced shift control to the neutral position” is being performed in response to the detection of entrained rotation, the entrained rotation in the engine of the central outboard motor3C becomes undetectable, the “lever-following shift control” is performed (see steps S3, S4, and S5inFIG. 7).

FIG. 9is a diagram for explaining procedures of the association mode switching process executed by the remote controller ECU10. This process is performed repeatedly at every predetermined control cycle.

The remote controller ECU10judges whether or not the lever positions of the two levers71S and71P are both at the neutral positions (step S21). If the lever position of at least one of the two levers71S and71P is not at the neutral position (step S21: NO), the present process is ended.

If it is judged in step S21that the lever positions of the two levers71S and71P are both at the neutral positions (step S21: YES), the remote controller ECU10judges whether or not all of the flags FP, FC, and FS, corresponding to the respective outboard motors3P,3C, and3S, are reset (FP=FC=FS=0) (step S22). The case where all of the flags FP, FC, and FS are reset is a case where the “lever-following shift control” is being performed on all of the outboard motors3. In this case, the remote controller ECU10sets the association mode to the basic mode (FIG. 5A) (step S23). The present process is then ended.

If in step S22, it is judged that not all of the flags FP, FC, and FS are in the reset state (step S22: NO), the remote controller ECU10judges whether or not the flag FP corresponding to the port-side outboard motor3P is set to 1 (step S24). The case where the flag FP is set to 1 (step S24: YES) is a case where the “forced shift control to the neutral position” is being performed on the port-side outboard motor3P. In this case, the remote controller ECU10sets the association mode to the first modified mode (FIG. 5B) (step S25). It thereby becomes possible to select the shift position of the central outboard motor3C by operation of just the port-side lever71P and to select the shift position of the starboard-side outboard motor3S by operation of just the starboard-side lever71S. Maneuvering of the hull2by the two outboard motors3C and3S is thus made easy. That is, in the basic mode (FIG. 5A), both the starboard-side and port-side levers71P and71S must be operated to the forward drive position or the reverse drive position to set the shift position of the central outboard motor3C at the forward drive position or the reverse drive position. Marine vessel maneuvering after stopping of the engine of the port-side outboard motor3P is thus not necessarily easy. Marine vessel maneuvering is thus made easy by associating the levers71P and71S with the outboard motors3C and3S, respectively, in accordance with the first modified mode. After the process of step S25, the present process is ended.

If in step S24, the flag FP is not set to 1, the remote controller ECU10judges whether or not the flag FS corresponding to the starboard-side outboard motor3S is set to 1 (step S26). A case where the flag FS is set to 1 (step S26: YES) is a case where the “forced shift control to the neutral position” is being performed on the starboard-side outboard motor3S. In this case, the remote controller ECU10sets the association mode to the second modified mode (FIG. 5C) (step S27). It thereby becomes possible to select the shift position of the central outboard motor3C by operation of just the starboard-side lever71S and to select the shift position of the port-side outboard motor3P by operation of just the port-side lever71P. Maneuvering of the hull2by the two outboard motors3P and3C is thus made easy. After the process of step S27, the present process is ended.

If in step S26described above, the flag FS is not set to 1 (step S26: NO), the remote controller ECU10ends the present process without changing the association mode.

FIGS. 10A-10Dare diagrams for explaining a specific example of changing the association mode of the levers and the outboard motors.

Here, a case shall be assumed where a fault occurs in the engine of the port-side outboard motor3P when the hull2is undergoing forward drive by the forward drive direction propulsive forces of the engines of the three outboard motors3with the association mode of the levers and the outboard motors being the basic mode as shown inFIG. 10A. In such a case, the user operates the start/stop switch82P to stop the engine of the port-side outboard motor3P in which the fault has occurred. If after the engine of the port-side outboard motor3P is stopped, the crankshaft of the engine rotates due to entrained rotation, the outboard motor ECU30P judges that entrained rotation is occurring in the engine. That is, the outboard motor ECU30P detects the entrained rotation.

Upon detecting the entrained rotation, the outboard motor ECU30P performs the “forced shift control to the neutral position” on the port-side outboard motor3P as shown inFIG. 10B. The shift position of the engine of the port-side outboard motor3P is thereby forcibly set at the neutral position. In this case, the flag FP is set to 1 (FP=1).

When both levers71P and71S are thereafter returned to the neutral positions as shown inFIG. 10C, a negative judgment is made in step S22and a positive judgment is made in step S24ofFIG. 9because the flag is FP=1. The association mode of the levers and the outboard motors is thus set to the first modified mode (step S25ofFIG. 9). That is, the port-side lever71P is associated with the central outboard motor3C, and the starboard-side lever71S is associated with the starboard-side outboard motor3S.

Thus, in this state, even if just the port-side lever71P is inclined forward beyond the forward drive shift-in position, the shift position of the central outboard motor3C is switched to the forward drive position and the hull2is driven forward as shown inFIG. 10D.

FIG. 11is a flowchart of a modification example of the shift control process executed by the outboard motor ECU30.

The processes of steps S1to S9ofFIG. 11are preferably the same as the processes of steps S1to S9inFIG. 7. In the shift control process ofFIG. 11, the processes of step S11and step S12are added to the shift control process ofFIG. 7.

That is, in the shift control process ofFIG. 11, the outboard motor ECU30first judges whether or not the flag F corresponding to the outboard motor ECU30is set to 1 (step S11). If the flag F is not set to 1 (F=0), the outboard motor ECU30enters step S1and performs the processes from step S1onward.

On the other hand, if in step S11described above, the flag F is set to 1 (F=1), it is judged whether or not a lever operation for returning the shift position of the outboard motor3to the neutral position is performed (step S12). Specifically, this judgment is made by judging whether or not the target shift position of the outboard motor3is the neutral position. As described above, the target shift position of the outboard motor3is determined by the remote controller ECU10in accordance with the lever/outboard motor association mode and the operation positions of the levers71.

If the target shift position of the outboard motor3is the neutral position, the outboard motor ECU30judges that the lever operation for returning the shift position of the outboard motor3to the neutral position is performed. On the other hand, if the target shift position of the outboard motor3is not the neutral position, the outboard motor ECU30judges that the lever operation for returning the shift position of the outboard motor3to the neutral position is not performed.

If the outboard motor ECU30judges that the lever operation for returning the shift position of the outboard motor3to the neutral position is not performed (step S12: NO), the present process is ended without performing the processes of step S1to step S9. On the other hand, if the outboard motor ECU30judges that the lever operation for returning the shift position of the outboard motor3to the neutral position is performed (step S12: YES), step S1is entered and the processes from step S1onward are performed.

That is, in the present modification example, in the case where the shift position of the outboard motor3is forcibly controlled to be at the neutral position, the shift position is maintained at the neutral position until the lever operation for returning the shift position of the outboard motor3to the neutral position is performed.

Here, for example, it shall be assumed that the engine of one outboard motor3is stopped due to a fault occurring in the outboard motor3during traveling of the marine vessel. When entrained rotation thereafter occurs in the stopped engine and this is detected, the shift position of the corresponding outboard motor3is forcibly set to the neutral position by the “forced shift control to the neutral position.” When the shift position of the outboard motor3is forcibly set to the neutral position, entrained rotation of the engine of the outboard motor3no longer occurs.

When entrained rotation of the engine of the outboard motor3no longer occurs, the “lever-following shift control” is performed in the shift control process shown inFIG. 7(see step S5). That is, depending on subsequent lever operation, the shift position of the outboard motor3may be switched to the forward drive position or the reverse drive position, and there is thus a possibility of entrained rotation occurring in the engine again. There is thus a possibility that the “forced shift control to the neutral position” and the “lever-following shift control” are repeated alternately on the outboard motor3. In such circumstances, an operation of shifting in and an operation of shifting out are repeated alternately and wasteful switching of the shift position is performed frequently. With the modification example shown inFIG. 11, performing of such wasteful switching of the shift position can be prevented.

If the shift position of the outboard motor3is forcibly switched to the neutral position by the “forced shift control to the neutral position” (step S7), the shift position of the outboard motor3may be maintained at the neutral position until the engines of all outboard motors3stop. In this case, in place of step S12inFIG. 11, the outboard motor ECU30is made to judge whether or not the engines of all of the outboard motors3are stopped as shown inFIG. 12(step S12A). In this case, the outboard motor ECU30ends the present process if the engine of at least one of the outboard motors3is running, and enters the process of step S1if the engines of all of the outboard motors3are stopped.

Also, as shown inFIG. 4, the speed sensor12for detecting the speed of the marine vessel may be provided, and maintaining or cancellation of the “forced shift control to the neutral position” may be performed based on the speed of the marine vessel. That is, if the shift position of the outboard motor3is forcibly switched to the neutral position by the “forced shift control to the neutral position” (step S7), the shift position of the outboard motor3may be maintained at the neutral position until the speed of the marine vessel becomes no more than a predetermined threshold value. In this case, in place of step S12inFIG. 11, the outboard motor ECU30is made to judge whether or not the speed of the marine vessel detected by the speed sensor12is no more than the predetermined threshold value as shown inFIG. 13(step S12B). In this case, the outboard motor ECU30ends the present process if the speed of the marine vessel exceeds the predetermined threshold value, and enters the process of step S1if the speed of the marine vessel is no more than the predetermined threshold value.

Yet further, a docking detection unit that detects that the marine vessel is docked may be provided, and the maintaining or cancellation of the “forced shift control to the neutral position” may be performed based on the docking detection result. That is, if the shift position of the outboard motor3is forcibly switched to the neutral position by the “forced shift control to the neutral position” (step S7), the shift position of the outboard motor3may be held at the neutral position until it is detected that the marine vessel is docked.

As the docking detection unit, for example, an arrangement that uses a navigation apparatus to detect that the marine vessel is docked at a scheduled docking position set in advance may be used. Also, a docking detection unit with an arrangement that is arranged to measure a distance to a scheduled docking position by a laser and detect that the marine vessel is docked when the distance becomes no more than a predetermined value may be used. Further, a docking detection unit with an arrangement that detects that the marine vessel is docked based on an output of a proximity sensor that is arranged to detect that the marine vessel has approached the scheduled docking position may be used. The proximity sensor may be arranged to detect contact with, for example, a quay, a pier, another marine vessel, or other target of berthing.

FIG. 14is a diagram for explaining an electrical arrangement related to electric power supply control and start/stop control of the outboard motors of the marine vessel1.

The three remote controller ECUs (electronic control units)10S,10C, and10P are provided in respective correspondence to the three remote controllers7S,7C, and7P. That is, the remote controller ECU10S corresponding to the starboard-side remote controller7S, the remote controller ECU10C corresponding to the central remote controller7C, and the remote controller ECU10P corresponding to the port-side remote controller7P are included. The remote controller ECUs10S,10C, and10P are referred to collectively as the “remote controller ECUs10.”

Three batteries12S,12C, and12P and three electric power supply relays13S,13C, and13P are provided in respective correspondence to the three outboard motors3S,3C, and3P. That is, the battery12S and the electric power supply relay13S corresponding to the starboard-side outboard motor3S, the battery12C and the electric power supply relay13C corresponding to the central outboard motor3C, and the battery12P and the electric power supply relay13P corresponding to the port-side outboard motor3P are included. In the following description, the batteries12S,12C, and12P shall be referred to collectively as the “batteries12” and the electric power supply relays13S,13C, and13P shall be referred to collectively as the “electric power supply relays13.”

In terms of arrangement, each of the outboard motor ECUs30S,30C, and30P is a motor control unit that controls an engine69as the motor. These are the same in arrangement, and the outboard motor ECU30C, corresponding to the central outboard motor3C, shall mainly be described. The outboard motor ECUs30S,30C, and30P shall be referred to collectively as the “outboard motor ECUs30.”

The outboard motor ECU30C includes a computer (microcomputer)160, an electric power supply circuit171, a switching transistor172, and a plurality of reverse current blocking diodes173,174, and175. The electric power supply circuit171is arranged to generate electric power supply voltages necessary for the computer160and electric components inside the outboard motor3C including outboard motor ECU30C.

The battery12C is connected to the electric power supply circuit171via the electric power supply relay13C and the diode173inside the outboard motor ECU30C. When the electric power supply relay13C conducts, electric power is supplied from the battery12C to the electric power supply circuit171inside the outboard motor ECU30C. One end of a coil of the electric power supply relay13C is connected to the battery12C and the other end is grounded via the switching transistor172.

A base of the switching transistor172is connected to the corresponding remote controller ECU10C via the diode174and an electric signal line14. The base of the switching transistor172is further connected to the computer160via the diode175. When the switching transistor172turns on, the electric power supply relay13C is put in the conducting state. The switching transistor172is put in the on state when a wake-up signal, transmitted to the base thereof from the corresponding remote controller ECU10C via the electric signal line14, is set to an H level or when a self-holding output, transmitted to the base thereof from the computer160, is set to the H level.

The remote controller ECU10C corresponding to the central remote controller7C shall mainly be described below because the arrangements of the respective remote controller ECUs10S,10C, and10P are substantially the same.

The remote controller ECU10C includes a computer (microcomputer)130, an electric power supply circuit141, a switching transistor142, a gate143, and a plurality of reverse blocking diodes144and145. The electric power supply circuit141is arranged to generate electric power supply voltages for the computer130and for peripheral equipments connected to the computer130. The electric power supply circuit141is connected via the switching transistor142to the corresponding battery12C. When the switching transistor142turns on, electric power is supplied from the battery12C to the electric power supply circuit141.

The operation panel8includes a common electric power supply switch81A and a common start switch81B that are arranged to be actuated in response to operation of the key switch81.

The common electric power supply switch81A is a switch that is turned on when the key switch81(seeFIG. 2) is operated to the on position. One end of the common electric power supply switch81A is connected to one of the batteries12. In the present preferred embodiment, the one end of the common electric power supply switch81A is connected to the battery12C corresponding to the central outboard motor3C. The other end of the common electric power supply switch81A is connected to a common electric power supply line191.

The common electric power supply line191is drawn inside the respective remote controller ECUs10. In regard to the remote controller ECU10C, the common electric power supply line191is connected to an anode of the diode144. The cathode of the diode144is connected to a base of the switching transistor142. The anode of the diode144is connected to the computer130and one input terminal (signal input terminal) of the gate143(AND gate). The base of the switching transistor142is further connected to the computer130via the diode145.

As mentioned above, when the switching transistor142turns on, electric power is supplied to the power supply circuit141. The switching transistor142is put in the on state when the common electric power supply switch81A turns on or when a self-holding output, transmitted to the base thereof from the computer130, is set to the H level.

The other input terminal (control input terminal) of the gate143is connected to the computer130. The output terminal of the gate143is connected via the electric signal line14to the diode174inside the corresponding outboard motor ECU30C. The electric signal line14is used for transmission of the wake-up signal output from the gate143. The wake-up signal is set to the H level when the conditions that the common electric power supply switch81A is in the on state and a gate control signal transmitted to the control input terminal of the gate143from the computer130is set to the H level are met. When these conditions are not met, the wake-up signal is set to an L level.

The common start switch81B is a switch that is arranged to be turned on when the key switch81is operated to the start position. One end of the common start switch81B is connected to the common electric power supply line191. The other end of the common start switch81B is connected in common to the computers130inside the remote controller ECUs10P,10C, and10S.

Each of the start/stop switches82S,82C, and82P, included in the operation panel8, has one end connected to the common electric power supply line191. Each of the start/stop switches82S,82C, and82P has the other end connected to the computer130inside the corresponding remote controller ECU10S,10C, or10P.

The computers130inside the respective remote controller ECUs105,10C, and10P are connected to the respectively corresponding lamps83S,83C, and83P and the respectively corresponding position sensors11S and11P. The signals from both position sensors11S and11P are input into the remote controller ECU10C corresponding to the central outboard motor. The computers130inside the respective remote controller ECUs10S,10C, and10P are also connected to the computers160of the respectively corresponding outboard motor ECUs30S,30C, and30P via the bus20arranged from a LAN cable of the inboard LAN (local area network). The bus20is used for communication of control signals and various information.

The respective gauges9S,9C, and9P are connected, for example, to the bus20. The gauges9S,9C, and9P can thereby perform data communication with the computers160inside the corresponding outboard motor ECUs30S,30C, and30P and the computers130inside the corresponding remote controller ECUs10S,10C, and10P.

When the key switch81is operated from the off position to the on position, the common electric power supply switch81A turns on. When the common electric power supply switch81A turns on, the switching transistor142turns on, and a common electric power supply on signal that is input into the computer130and the input signal into the signal input terminal of the gate143are set to the H level. When the switching transistor142turns on, electric power is supplied from the battery12to the electric power supply circuit141. The electric power supply of the computer130is thus turned on and electric power is supplied to the peripheral equipments thereof. When the electric power supply of the computer130turns on, the computer130sets the self-holding output to the switching transistor142to the H level. The switching transistor142thus maintains the on state.

When the common electric power supply on signal that is input into the computer130is set to the H level, the computer130sets the gate control signal, input into the control input terminal of the gate143, to the H level. Also, the computer130transmits a common electric power supply on command to the computer160inside the corresponding outboard motor ECU30via the bus20. Further, the computer130turns on the corresponding lamp83.

An H level signal is already input in the signal input terminal of the gate143, and thus, when the control signal input into the control input terminal of the gate143by the computer130is set to the H level, the wake-up signal output from the gate143is set to the H level. The switching transistor172in the corresponding outboard motor ECU30thus turns on and the corresponding electric power supply relay13is put in the conducting state.

When the electric power supply relay13is put in the conducting state, electric power is supplied to the electric power supply circuit171from the corresponding battery12via the electric power supply relay13and the diode173. The electric power supply of the computer160is thereby turned on, and electric power is supplied to respective portions inside the corresponding outboard motor3.

As mentioned above, when the common electric power supply switch81A is turned on, the common electric power supply on command is transmitted to the computer160from the computer130in the corresponding remote controller ECU10. Upon receiving the common electric power supply on command, the computer160sets the self-holding output to the switching transistor172to the H level. The switching transistor172thus maintains the on state and the electric power supply relay13maintains the conducting state. The electric power supplies of the three outboard motors3can thus be turned on all at once by operating the key switch81from the off position to the on position.

When the key switch81is operated from the on position to the start position, the common start switch81B turns on. When the common start switch81B turns on, a common start signal is input into the computers130in the respective remote controller ECUs10. Upon input of the common start signal, the computers130in the respective remote controller ECUs10transmit an engine start command via the bus20to the computers160in the corresponding outboard motor ECUs30under the condition that the starting allowing conditions are met. The starting allowing conditions include, for example, that the lever positions of the corresponding remote controllers7are at the neutral positions (the target shift positions are the neutral positions) and the shift positions of the corresponding outboard motors3are the neutral positions.

Upon receiving the engine start command, the respective computers160perform the engine starting process. In the engine starting process, each computer160energizes the starter45and performs fuel supply control and ignition control to start the engine69. The engines of the three outboard motors3can thus be started all at once by operating the key switch81from the on position to the start position.

When the key switch81is operated from the on position to the off position, the common electric power supply switch81A turns off. When the common electric power supply switch81A turns off, the common electric power supply on signal, input into the computers130in the respective remote controller ECUs10, is set to the L level, and the wake-up signal is set to the L level. When the common electric power supply on signal input into the computers130is set to the L level, the computers130transmit an electric power supply off command (common electric power supply off command) to the computers160in the corresponding outboard motor ECUs30via the bus20. After executing other necessary ending processes, each computer130sets the self-holding output to the switching transistor142to the L level. The switching transistor142is thereby turned off and the supply of electric power to the electric power supply circuit141is cut off. The electric power supply of the computer130is thus turned off and the supply of electric power to the peripheral circuits is also stopped.

Upon receiving the electric power supply off command (common electric power supply off command) from the computers130in the corresponding remote controller ECUs10, the computers160in the respective outboard motor ECUs30execute predetermined ending processes and thereafter set the self-holding output to the switching transistors172to the L level. The wake-up signal is at the L level and thus when the self-holding output to each switching transistor172is set to the L level, the switching transistor172turns off. Self-holding of the electric power supply relay13is thereby canceled and the supply of electric power to the electric power supply circuit171is cut off. The electric power supplies of the computers160are thus turned off, and the supply of electric power to the respective portions inside the corresponding outboard motors3is also stopped. The electric power supplies of the three outboard motors3can thus be cut off all at once by operating the key switch81from the on position to the off position.

Operations performed when a start/stop switch82is operated with the common electric power supply switch81A being in the on state shall now be described.

FIG. 15is a flowchart of procedures of a process (first operation example) executed by the computer130inside the corresponding remote controller ECU10when the start/stop switch82is operated with the common electric power supply switch81A being in the on state. The computer130executes this process repeatedly at every control cycle.

When the start/stop switch82is turned on (depressed) (step S101: YES), the computer130judges whether or not the engine of the corresponding outboard motor3is running (step S102). Information, such as the running circumstances of the corresponding engine, the shift position of the corresponding outboard motor, etc., is transmitted from the computer160inside the corresponding outboard motor ECU30to the computer130in the remote controller ECU10via the bus20. The judgment in step S102is made based on the information on the engine running circumstances transmitted from the corresponding computer160.

If the engine is in the stopped state (step S102: NO), the computer130judges whether or not the starting allowing conditions are met (step S103). The starting allowing conditions include, for example, that the lever position of the corresponding remote controller7is at the neutral position (the target shift position is the neutral position) and the shift position of the corresponding outboard motor3is the neutral position. If the starting allowing conditions are met (step S103: YES), the computer130outputs the engine start command (step S104). The present process is then ended. The engine start command output from the computer130is transmitted via the bus20to the computer160in the corresponding outboard motor ECU30.

If the computer130judges in step S103that the starting allowing conditions are not met, the present process is ended.

If in step S102, it is judged that the engine of the corresponding outboard motor3is running (step S102: YES), the computer130outputs the engine stop command (step S105). The engine stop command output from the computer130is transmitted via the bus20to the computer160inside the corresponding outboard motor ECU30.

Also, the computer130starts a timer for measuring a predetermined, fixed amount of time (step S106). It is then judged whether or not the predetermined, fixed amount of time has elapsed with the start/stop switch83being kept on from step S101(steps S107and S108). If the start/stop switch83is turned off before the elapse of the predetermined, fixed amount of time (step S107: YES), the computer130judges that a “short pressing operation” and not a “long pressing operation” has been performed and the present process is ended.

If the predetermined, fixed amount of time has elapsed with the start/stop switch83being kept on from step S101(step S108: YES), the computer130judges that the “long pressing operation” of the start/stop switch83is performed, and step S109is entered. In step S109, the computer130sets the gate control signal to the L level. The wake-up signal is thereby set to the L level. Also, the computer130outputs an electric power supply off command (individual electric power supply off command; however, the command itself is the same command as the common electric power supply off command). The electric power supply off command (individual electric power supply off command) output from the computer130is transmitted via the bus20to the computer160inside the corresponding outboard motor ECU30. Further, the computer130turns off the corresponding lamp83and ends the present process.

FIG. 16is a flowchart of procedures of a process executed by the computer160inside the outboard motor ECU30. This process is executed repeatedly at every control cycle.

The computer160monitors whether or not the engine stop command is received (step S131), whether or not the engine start command is received (step S132), and whether or not the electric power supply off command (the common electric power supply off command or the individual electric power supply off command) is received (step S133).

When the computer160receives the engine stop command (step S131: YES), the computer160performs the engine stopping process for stopping the corresponding engine (step S134). Specifically, the computer160stops the engine by stopping the fuel injection by the injector and stopping the ignition operation by the spark plug.

When the computer160receives the engine start command (step S32: YES), the computer160performs the engine starting process for starting the corresponding engine (step S135). Specifically, the computer160starts the engine by energizing the starter and performing fuel supply control and ignition control.

When the computer160receives the electric power supply off command (step S133: YES), the computer160performs an ECU ending process for normal shutdown of the computer160(step S136). Thereafter, computer160sets the self-holding output to the switching transistor172to off (the L level) (step S137). The electric power supply of the computer160is thereby turned off.

As described above, in the case where the computer130inside the remote controller ECU10outputs the electric power supply off command (see, for example, step S109inFIG. 15), the wake-up signal is set to the L level. Thus, when the self-holding output to the switching transistor172is set to the L level in step S137, the switching transistor172is turned off and the corresponding electric power supply relay13is put in the cutoff state. The supply of electric power from the corresponding battery12to the electric power supply circuit171is thereby cut off and the electric power supply of the computer160is cut off.

FIG. 17is a diagram for explaining transitions (state transitions) of the on/off state of the electric power supply of the outboard motor3and the running state of the engine of the outboard motor3. The state transitions are performed for each outboard motor3. Here, the state transitions of the central outboard motor3C shall be described.

In an initial state101, the key switch81is at the off position and the lamp83cis in the unlit state. When in the initial state101, the key switch81is operated from the off position to the on position, the electric power supply of the outboard motor3C is turned on and an engine stopped state102is entered. In the engine stopped state, the lamp83C is put in a lit state.

When in the engine stopped state102, the start/stop switch82C is depressed, the engine of the outboard motor3C is started and the engine running state103is entered (see steps S101,5102,5103, and5104inFIG. 15and steps S132and5135inFIG. 16). When in the engine running state103, the short pressing operation of the start/stop switch82C is performed, the engine of the outboard motor3is stopped as indicated by an arrow111and a transition into the engine stopped state102occurs (see steps S101,5102, and5105inFIG. 15and steps S131and5134inFIG. 16).

When in the engine running state103, the long pressing operation of the start/stop switch82C is performed, the state transitions as indicated by an arrow112. That is, after transitioning into the engine stopped state102(see steps S101,5102, and5105inFIG. 15and steps S131and5134inFIG. 16), the electric power supply of the outboard motor3C is turned off individually and an individual electric power supply off mode104is entered (see steps S106to S109inFIG. 15and steps S133,5136, and5137inFIG. 16). In the individual electric power supply off mode104, the electric power supply of the outboard motor3C is off and thus the lamp83C is put in the unlit state despite the key switch81being at the on position.

When in the individual electric power supply off mode104, the key switch81is operated from the on position to the off position, transition into the initial state101occurs as indicated by an arrow113.

Here, for example, it shall be assumed that when the electric power supplies of all of the outboard motors3are on and the engines are running, a fault occurs in the engine of one of the outboard motors3. In such a case, the electric power supplies of all of the outboard motors3can be turned off by operation of the key switch81. However, it is not possible to turn off the electric power supply of just the outboard motor3, in which the engine fault has occurred, by operation of the key switch81.

In the first preferred embodiment, in such a case, the electric power supply of just the outboard motor3with the faulty engine can be turned off by performing the long pressing operation of the start/stop switch82corresponding to the faulty outboard motor3(see an arrow112inFIG. 17). Specifically, when the long pressing operation of the start/stop switch82corresponding to the outboard motor3with the faulty engine is performed, the YES judgment is made in each of steps S101and5102inFIG. 15, the engine stop command is output (see Step S105). Also, the YES judgment is made in Step S108, the wake-up signal is set to the L level, and the electric power supply off command (individual electric power supply off command) is output (see step S109). Consequently, the electric power supply of the outboard motor3with the faulty engine is turned off (see step S137inFIG. 16).

The electric power supply of the outboard motor3, with which the engine cannot be started due to a fault, etc., can thereby be turned off individually to suppress wasteful consumption of electric power and prevent running out of the battery corresponding to the outboard motor3. Also, engine starting due to entrained rotation can be prevented because the electric power supply of the outboard motor3can turned off individually. Running of the marine vessel is not disrupted because the electric power supply of the outboard motor3, in which the fault, etc., has occurred, can be put in the off state while keeping the electric power supplies of the other normal outboard motors3in the on state.

Another operation example (second operation example) of electric power supply control and start/stop control shall now be described. An outboard motor3can be put in the individual electric power supply off mode by the long pressing operation of the corresponding start/stop switch83in the second operation example as well. Further, in the second operation example, by operating the start/stop switch83when the corresponding outboard motor3is in the individual electric power supply off mode, the electric power supply of the outboard motor3can be turned on and the engine thereof can be started.

To describe by way ofFIG. 17, when, for example, the start/stop switch83C is depressed with the outboard motor3C being in the individual electric power supply off mode104, the engine running state103can be transitioned into a state as indicated by a broken-line arrow114.

FIG. 18is a flowchart of specific process contents (second operation example) performed by the computer130inside the remote controller ECU10. The computer130repeats this process at every control cycle. The process contents of the computer160inside the outboard motor ECU30are substantially the same as those of the first operation example.

The respective steps S101to S109inFIG. 18are the same as the respective steps S101to S109inFIG. 15. In comparison to the flowchart ofFIG. 15, the flowchart ofFIG. 18differs in that step S111, step S112, and step S113are added.

In the second operation example, when the start/stop switch82is turned on (depressed) (step S101: YES), it is judged whether or not a flag f is set to 1 (step S111). The flag f is a flag for storing that the outboard motor3is in the individual electric power supply off mode (the state indicated by reference numeral104inFIG. 17). As shall be described below, the flag f is set to 1 (f=1) when the outboard motor3is put in the individual electric power supply off mode. The flag f is reset (f=0) during the initialization process that is executed when the electric power supply of the computer130inside the remote controller ECU10is turned on.

If the flag f is reset (f=0) (step S111: NO), that is, if the corresponding outboard motor3is not in the individual electric power supply off mode, the computer130enters step S102as in the first operation example and judges whether or not the engine of the corresponding outboard motor3is running. If the corresponding outboard motor3is running, the computer130outputs the engine stop command (step S105) and starts the timer (step S106).

It is, then, judged whether or not a predetermined, fixed time has elapsed with the start/stop switch83being kept on (steps S107and S108). If the predetermined, fixed time has elapsed with the start/stop switch83being kept on (step S108: YES), that is, if the “long pressing operation” of the start/stop switch83is performed, the flag f is set to 1 (f=1) (step S113). Step S109is then entered. In step S109, the computer130provides the L level signal to the gate143to set the wake-up signal to the L level, outputs the electric power supply off command (individual electric power supply off command) and turns off the corresponding lamp83. The corresponding outboard motor3is thereby put in the individual electric power supply off mode. The flag f is thus set to 1 (f=1) when the outboard motor3is put in the individual electric power supply off mode.

The operation of the computer130in a case where it is judged in step S111that the flag f is set to 1 (f=1) (step S111: YES), that is, the corresponding outboard motor3is in the individual electric power supply off mode is as follows. That is, the computer130provides the H level signal to the gate143to set the wake-up signal to on (to the H level), outputs the electric power supply on command, and resets the flag f (f=0) (step S112). The electric power supply on command output from the computer130is transmitted via the bus20to the computer160inside the corresponding outboard motor ECU30. The electric power supply of the outboard motor3that is in the individual electric power supply off mode is thereby turned on.

After performing the process of step S112, the computer130enters step S103and judges whether or not the starting allowing conditions are met. If the starting allowing conditions are met (step S103: YES), the engine start command is output (step S104). The engine start command output from the computer130is transmitted via the bus20to the computer160inside the corresponding outboard motor ECU30. The engine of the corresponding outboard motor3is thus started. If in step S103, it is judged that the starting allowing conditions are not met (step S103: NO), the computer130ends the present process.

In the second operation example, by operation of the start/stop switch83corresponding to the outboard motor3when the outboard motor3is in the individual electric power supply off mode, the electric power supply of the outboard motor3can be turned on and the engine thereof can be started. That is, the electric power supply of the outboard motor3that is in the individual electric power supply off mode can be turned on and the engine thereof can be started by a simple operation.

A plurality of individual electric power supply on/off switches184S,184C, and184P for turning on and off the electric power supplies of the respective outboard motors3S,3C, and3P individually may be provided on the operation panel8as shown inFIG. 19. The individual electric power supply on/off switch184S corresponds to the starboard-side outboard motor3S. The individual electric power supply on/off switch184C corresponds to the central outboard motor3C. The individual electric power supply on/off switch184P corresponds to the port-side outboard motor3P. The individual electric power supply on/off switches184S,184C, and184P shall be referred to collectively as the “individual electric power supply on/off switches184.” The operation signals of the individual electric power supply on/off switches184are input into the corresponding remote controller ECUs10.

In this case, the computer130in each remote controller ECU10executes the process shown inFIG. 20in accordance with operation of the corresponding individual electric power supply on/off switch184. The contents of the process of the computers160in the outboard motor ECUs30do not differ.

Referring toFIG. 20, when the corresponding individual electric power supply on/off switch184is operated (step S121: YES), the computer130in the remote controller ECU10judges whether or not the electric power supply of the corresponding outboard motor3(outboard motor ECU30) is in the on state (step S122). If the electric power supply of the corresponding outboard motor3is in the on state (step S122: YES), the computer130provides the L level signal to the gate143and thereby sets the wake-up output to off (to the L level). Further, the computer130outputs the electric power supply off command (individual electric power supply off command) and turns off the corresponding lamp83(step S23).

The electric power supply off command (individual electric power supply off command) output from the computer130is transmitted via the bus20to the corresponding outboard motor ECU30. The electric power supply of the corresponding outboard motor3is put in the off state (individual electric power supply off mode). In the case of application to the second operation example, the computer130further sets the flag f to 1 (f=1) in step S123.

If in step S122, the electric power supply of the corresponding outboard motor3is in the off state (step S122: NO), the computer130sets the wake-up output to on (to the H level), outputs the electric power supply on command, and turns on the corresponding lamp83(step S124). The electric power supply on command output from the computer130is transmitted to the corresponding outboard motor ECU30via the bus20. The electric power supply of the corresponding outboard motor3is thereby put in the on state. In the case of application to the second operation example, the computer130further resets the flag f (f=0) in step S124.

Thus, in the case where the individual electric power supply on/off switch184is provided for each outboard motor3, transition from the individual electric power supply off mode104to the engine stopped state102is enabled as indicated by a broken-line arrow115inFIG. 17. For example, when, in a case where the outboard motor3C is in the individual electric power supply off mode104, the corresponding individual electric power supply on/off switch184is operated, the electric power supply of the outboard motor3is turned on and the engine stopped state102is entered (steps S121,5122, and S124inFIG. 20).

Also, transition to the individual electric power supply off mode104from the engine stopped state102can be performed without starting the engine as indicated by a broken-line arrow116inFIG. 17. For example, when in a case where the outboard motor3C is in the engine stopped state102, the corresponding individual electric power supply on/off switch184is operated, the electric power supply of the outboard motor is turned off and the individual electric power supply off mode104is entered (steps S121,5122, and5123inFIG. 20).

FIGS. 21A-21Dare diagrams for describing operations of a marine vessel according to a second preferred embodiment of the present invention. Whereas with the first preferred embodiment, the marine vessel preferably including three outboard motors3has been described, the present invention can also be applied to a marine vessel with a plurality of outboard motors3of a number other than three (two motors or no less than four motors).FIGS. 21A-21Dshow operations of the second preferred embodiment in which the present invention is applied to a marine vessel that includes two outboard motors3P and3S and a single lever for selecting the shift positions of these motors. This marine vessel has an arrangement where the central outboard motor3C and portions corresponding thereto are eliminated from the first preferred embodiment described above.

In the marine vessel according to the second preferred embodiment, the single lever is associated with the two outboard motors3P and3S. That is, when the lever is set at the forward drive position that is inclined forward to no less than the forward drive shift-in position, the shift positions of the outboard motors3P and3S are both controlled to be at the forward drive positions. Also, when the lever is set at the reverse drive position that is inclined in reverse to no less than the reverse drive shift-in position, the shift positions of the outboard motors3P and3S are both controlled to be at the reverse drive positions. When the lever is set at the neutral position, the shift positions of outboard motors3P and3S are both controlled to be at the neutral positions.

A case where the a fault occurs in the engine of the port-side outboard motor3P when the two outboard motors3P and3S are generating propulsive forces in the forward drive direction and the hull2is being driven forward as shown inFIG. 21Ashall now be assumed.

In such a case, the user performs the operation (engine stopping operation) for stopping the engine of the faulty port-side outboard motor3P as shown inFIG. 21B. That is, the start/stop switch corresponding to the port-side outboard motor3P is depressed.

Based on the engine stopping operation, the outboard motor ECU30P corresponding to the port-side outboard motor3P performs the engine stopping process. If the engine does not stop within a fixed amount of time despite the engine stopping process being started, the outboard motor ECU30P judges that entrained rotation is occurring in the engine as shown inFIG. 21C. Also, in a case where, after the engine is put in the stopped state by the engine stopping process, the engine is put in the rotating state with the starter motor not being driven, the outboard motor ECU30P judges that entrained rotation is occurring in the engine as shown inFIG. 21C. That is, the outboard motor ECU30P detects the entrained rotation.

Upon detecting the entrained rotation, the outboard motor ECU30P sets the shift position of the engine of the port-side outboard motor3P to the neutral position by the “forced shift control to the neutral position” as shown inFIG. 21D. That is, the shift position of the central outboard motor3C is maintained at the neutral position regardless of the lever position. Thus, when the entrained rotation of the engine is detected, the shift position of the outboard motor that includes the engine is forcibly set at the neutral position, and the inability to stop an engine that should be stopped due to entrained rotation or the starting of an engine in a stopped state due to entrained rotation can thereby be prevented.

FIG. 22is a flowchart of a characteristic operation in a third preferred embodiment of the present invention. The third preferred embodiment includes, in addition to the arrangement of the first preferred embodiment, an arrangement for an ignition and injection cutting process for cutting ignition and fuel injection when shift-in of an outboard motor in the engine stopped state is detected. More specifically, each outboard motor ECU30executes the shift control (FIG. 7,FIG. 11toFIG. 13), and in parallel to the shift control, repeatedly executes the ignition and injection cutting process shown inFIG. 22at every predetermined control cycle.

In the ignition and injection cutting process, the outboard motor ECU30determines whether or not the engine of the corresponding outboard motor is in the stopped state (step S31). The outboard motor ECU30determines that the engine is in the stopped state when the engine is actually stopped and also when the engine stop command for the outboard motor is provided. Whether or not the engine is stopped is determined, for example, based on the output of the engine speed sensor43. For example, the outboard motor ECU30determines that the engine is stopped when the engine speed is no more than a predetermined value. The engine stop command is provided via the bus20to the outboard motor ECU30from the remote controller ECU10. The remote controller ECU10transmits the engine stop command to the outboard motor ECU30when the start/stop switch82corresponding to the outboard motor is operated during running of the engine of the outboard motor.

If the engine is determined not being in the stopped state (step S31: NO), the ignition and injection cutting process of the present control cycle is ended.

If the engine is determined being in the stopped state (step S31: YES), the outboard motor ECU30acquires the shift position of the outboard motor from the shift position sensor44(step S32). The outboard motor ECU30then determines whether or not the shift position is the forward drive position or the reverse drive position (step S33). That is, it is determined whether or not the shift mechanism is in the shift-in state (transmitting state) in which rotation is transmitted between the driveshaft and the propeller. If the shift mechanism is not in the shift-in state (step S33: NO), the ignition and injection cutting process of the present control cycle is ended.

If the shift mechanism is in the shift-in state (step S33: YES), the outboard motor ECU30further determines whether or not the electric power off command is provided from the remote controller ECU10(step S34) and whether or not the engine start command is provided from the remote controller ECU10(step S35). When the key switch81is operated to the off position, the remote controller ECUs10transmit the electric power supply off command to the respective outboard motor ECUs30via the bus20. Also, when a start/stop switch82is operated, the remote controller ECU10transmits the engine start command to the outboard motor ECU30of the outboard motor corresponding to the start/stop switch82when the engine of the outboard motor is stopped.

If neither the electric power supply off command nor the engine start command is provided (step S34: NO and step S35: NO), the outboard motor ECU30executes an ignition cutting control (step S36) and an injection cutting control (step S37). The ignition cutting control is a control of stopping the driving of the ignition coil46and prohibiting the discharge by the spark plug. The injection cutting control is a control of prohibiting fuel injection by the injector47.

On the other hand, if the electric power supply off command or the engine start command is provided (step S34: YES or step S35: YES), the outboard motor ECU30cancels the ignition cutting control and the injection cutting control (step S38).

If when the engine of a certain outboard motor is in the stopped state, the outboard motor is put in the shift-in state, entrained rotation may occur. If, at this time, the shift-in state is detected, the outboard motor ECU30executes the ignition cutting control and the injection cutting control immediately. Starting of the engine due to entrained rotation can thereby be avoided. With just the “forced shift control to the neutral position” by the shift control process described above (FIG. 7andFIG. 11toFIG. 13), engine starting by entrained rotation may not be avoided reliably. Thus, by using the ignition and injection cutting controls in combination, engine starting by entrained rotation can be avoided.

Upon receiving the electric power supply off command or the engine start command, the outboard motor ECU30interrupts the ignition cutting control and the injection cutting control. Put in another way, the ignition cutting control and the injection cutting control are maintained until the user operates the key switch81to the off position or performs the engine starting operation of the outboard motor by operating the corresponding start/stop switch82. Engine starting by entrained rotation can thereby be avoided reliably. Also, if the engine start command is provided, the ignition cutting control and the injection cutting control are interrupted and engine starting is thus enabled.

The present preferred embodiment may be modified by omitting the shift control process (FIG. 7andFIG. 11toFIG. 13). Engine starting by entrained rotation can be avoided by the ignition and injection cutting process in this case as well.

FIG. 23is a flowchart of a characteristic operation in a fourth preferred embodiment of the present invention. As with the third preferred embodiment, the fourth preferred embodiment includes an arrangement for the ignition and injection cutting process for cutting the ignition and the fuel injection upon detection of shift-in of an outboard motor in the engine stopped state in addition to the arrangement of the first preferred embodiment. However, whereas in the third preferred embodiment, the shift control process and the ignition and injection cutting process are individual control processes that are performed in parallel, an entrained rotation countering process in which the above processes are consolidated is executed in the fourth preferred embodiment. The entrained rotation countering process is executed repeatedly by the outboard motor ECU30at every predetermined control cycle. Among the steps shown inFIG. 23, the steps in which the same processes as those of the steps shown inFIG. 7orFIG. 22are provided with the same reference numerals.

The outboard motor ECU30determines whether or not the engine of the corresponding outboard motor is in the stopped state (step S31). If the engine is determined not to be in the stopped state (step S31: NO), the entrained rotation countering process of the present control cycle is ended.

If the engine is determined to be in the stopped state (step S31: YES), the outboard motor ECU30acquires the shift position of the outboard motor from the shift position sensor44(step S32). The outboard motor ECU30then determines whether or not the shift mechanism is in the shift-in state (transmitting state) (step S33). If the shift mechanism is not in the shift-in state (step S33: NO), the entrained rotation countering process of the present control cycle is ended.

If the shift mechanism is in the shift-in state (step S33: YES), the outboard motor ECU30further determines whether or not the electric power off command is provided from the remote controller ECU10(step S34) and whether or not the engine start command is provided from the remote controller ECU10(step S35). If neither the electric power supply off command nor the engine start command is provided (step S34: NO and step S35: NO), the outboard motor ECU30executes the ignition cutting control (step S36) and the injection cutting control (step S37). Further, the outboard motor ECU30sets the above-described flag F that expresses the state of the shift control to 1 (F=1) (step S6), executes the “forced shift control to the neutral position” (step S7), and executes the engine stop process (step S8). Further, the outboard motor ECU30executes the notification process for displaying that the execution of the “forced shift control to the neutral position” is in progress on the corresponding gauge9(step S9).

On the other hand, if the electric power supply off command or the engine start command is provided (step S34: YES or step S35: YES), the outboard motor ECU30cancels the ignition cutting control and the injection cutting control (step S38), and further resets the flag F (F=0) (step S4). The outboard motor ECU30further cancels the “forced shift control to the neutral position” and makes the shift control mode transition to the lever-following shift control (step S5).

If when the engine of a certain outboard motor is in the stopped state, the outboard motor is put in the shift-in state, entrained rotation may occur. If, at this time, the shift-in state is detected, the outboard motor ECU30executes the ignition cutting control and the injection cutting control immediately. Starting of the engine due to entrained rotation can thereby be avoided. Further, the outboard motor ECU30executes the “forced shift control to the neutral position” to cut off the driving force transmission path between the engine and the propeller. The entrained rotation state can thereby be resolved. That is, engine starting is prevented promptly by the cutting of the ignition and the injection, and the driving force transmission path is thereafter cut off to resolve the entrained rotation state.

Upon receiving the electric power supply off command or the engine start command, the outboard motor ECU30interrupts the ignition cutting control and the injection cutting control and interrupts the “forced shift control to the neutral position. Put in another way, the ignition cutting control, the injection cutting control, and the “forced shift control to the neutral position” are maintained until the user operates the key switch81to the off position or performs the engine starting operation of the outboard motor by operating the start/stop switch82. Engine starting by entrained rotation can thereby be avoided reliably, and reoccurrence of the entrained rotation state can also be avoided. Also, if the engine start command is provided, the ignition cutting control, the injection cutting control, and the “forced shift control to the neutral position” are interrupted, so that it becomes possible to start the engine and transmit the driving force of the engine to the propeller.

Although preferred embodiments of the present invention have been described above, the present invention can be put into practice in yet other embodiments and modes as well. For example, shift position changeover switches84P,84C, and84S can also be provided on the operation panel8as indicated by broken lines inFIG. 4. The shift position changeover switches84P,84C, and84S preferably are provided to individually switch the shift controls of the outboard motors3P,3C, and3C between the “forced shift control to the neutral position” and the “lever-following shift control.” These switches shall be referred to collectively as the “shift position changeover switches84.” The on/off states of the respective shift position changeover switches84are provided to the corresponding ECUs30from the remote controller ECUs10.

When the corresponding shift position changeover switches84are in the on states, the respective outboard motor ECUs30perform the “forced shift control to the neutral position” on the corresponding outboard motors3. The shift positions of the corresponding outboard motors3are thereby set to the neutral positions regardless of the lever positions.

On the other hand, when the corresponding shift position changeover switches84are in the off states, the respective outboard motor ECU30perform the “lever-following shift control” on the corresponding outboard motors3. The shift positions of the corresponding outboard motors3are thereby controlled in accordance with the mode of association of the levers and the outboard motors and the operation positions of the levers.

Also, in the preferred embodiments described above, the key switch81preferably includes, in addition to the function of turning on and cutting off the electric power supplies of all outboard motors3at once, the function of starting the engines of all outboard motors3at once. However, the key switch81may be a switch that does not include the engine all-start function and has only the all electric power supply on/cutoff function for all outboard motors3.

Also, although in the preferred embodiments described above, the start/stop switches82, each of which combines an engine start switch and an engine stop switch, are preferably included, different arrangements are possible. That is, start switches for starting the engines and stop switches for stopping the engines may be included individually.

Also, although in the arrangement shown inFIG. 4, three remote controller ECUs10are preferably provided, the actions of these may be consolidated in a single remote controller ECU.

Also, although in the preferred embodiments described above, the outboard motor is taken up as an example of the propulsion device, the present invention can be applied to marine vessel propulsion systems that include propulsion devices of other forms. As other examples of the propulsion device, an inboard/outboard motor (a stern drive or an inboard motor/outboard drive) and an inboard motor can be cited. The outboard motor includes a propulsion unit provided outboard of the vessel and having a motor and a propulsive force generating member (propeller), and is further provided with a steering mechanism that horizontally turns the entire propulsion unit with respect to the hull. The inboard/outboard motor includes a motor disposed inboard of the vessel, and a drive unit disposed outboard and having a propulsive force generating member and a steering mechanism. The inboard motor preferably has a configuration in which a motor and a drive unit are incorporated inside the hull, and a propeller shaft extends outboard from the drive unit. In this case, a steering mechanism is provided separately.

A non-limiting example of correspondence between the terms used in the “SUMMARY OF THE INVENTION” section and the terms used in the above description of the preferred embodiments is shown below:propulsion device: outboard motor3common electric power supply switch: key switch81, common electric power supply switch81Aelectric power supply control unit: remote controller ECU10abnormal state detection unit (entrained rotation detection unit):outboard motor ECU30, S3inFIG. 7, S3inFIG. 11toFIG. 13power transmission cutoff unit: outboard motor ECU30, S7inFIG. 7, S7inFIG. 11toFIG. 13starting device: starter motor45notification unit: gauge9, outboard motor ECU30, S9inFIG. 7, S9inFIG. 11toFIG. 13clutch mechanism: shift mechanism93clutch state selection operation unit: remote controller7speed detection unit: speed sensor12association changing unit: remote controller ECU10, S22to S27inFIG. 9stopped state detection unit: step S31inFIG. 15andFIG. 16clutch state detection unit: step S33inFIG. 15andFIG. 16ignition and injection control unit: steps S36and S37inFIG. 15andFIG. 16start switch: start/stop switch82motor control unit: outboard motor ECU30electric power supply off command input unit: start/stop switch82individual electric power supply switch: individual electric power supply on/off switch84first individual electric power supply off unit: remote controller ECU10,5101,5102, and5105to S109inFIG. 15first individual electric power supply on unit: remote controller ECU10,5101,5111,5112, and5113inFIG. 18second individual electric power supply off unit: remote controller ECU10,5121to5123inFIG. 20second individual electric power supply on unit: remote controller ECU10,5121,5122, and5124inFIG. 20operation judgment unit: remote controller ECU10,5101,5102, and S106to5108inFIG. 15display unit: lamp83

The present application corresponds to Japanese Patent Application Nos. 2009-87084, 2009-90386 and 2010-66645 filed in the Japan Patent Office on Mar. 31, 2009, Apr. 2, 2009 and Mar. 23, 2010, respectively, and the entire disclosures of the applications are incorporated herein by reference.