Patent Description:
Known is a technique in which in order to improve output of an engine mounted on a vehicle, the vehicle is equipped with an electric supercharger driven by an electric motor to increase intake pressure of the engine (see International Publication No. <CIT>, for example).

However, according to the moving machine equipped with the electric supercharger, since the number of parts mounted on the moving machine increases, the weight increases, and the degree of freedom of the layout of the parts deteriorates.

<CIT>, which forms the basis for the preamble of claim <NUM>, discloses a boost system for providing boost pressure to an air intake manifold of an engine including a supercharger having rotors and a supercharger input shaft, an electric motor/generator, and a planetary gear set. The planetary gear set operates to transfer torque between the supercharger input shaft, the electric motor/generator and a crankshaft of the engine. Other systems are known from <CIT> and <CIT>.

An electric supercharger-equipped moving machine according to claim <NUM> includes: an engine; a supercharger configured to increase intake pressure of the engine; an electric motor including a motor driving shaft; a power transmitting path including a power transmitting shaft through which driving power of the engine is transmitted to a propulsive power generating body; a main clutch through which a driving power of the engine is input to the power transmitting shaft; and a switching clutch configured to be able to block power transmission from the electric motor to the power transmitting shaft. The motor driving shaft is connected to the supercharger so as to be able to drive the supercharger when the switching clutch is in a disengaged state. The motor driving shaft is connected to the power transmitting shaft so as to be able to drive the propulsive power generating body when the switching clutch is in an engaged state and the main clutch is in a disengaged state.

According to the above configuration, in the engine supercharging mode in which the intake pressure of the engine is increased by the supercharger, the power generated by the electric motor is not transmitted to the power transmitting shaft by the switching clutch, and the supercharger is appropriately driven. On the other hand, in the electric traveling mode in which the electric motor is utilized as a traveling drive source, the power of the electric motor is transmitted to the power transmitting shaft through the switching clutch, and the driving power of the electric motor is transmitted to the propulsive power generating body. Therefore, in the electric supercharger-equipped moving machine, since the electric motor which drives the supercharger also serves as the traveling drive source, the increase in weight and the deterioration of the degree of freedom of the layout can be suppressed. It should be noted that: when the moving machine is a vehicle, the propulsive power generating body is a driving wheel; and when the moving machine is a personal watercraft, the propulsive power generating body is a jet pump.

<FIG> is a schematic diagram showing a normal engine mode of a traveling drive system <NUM> of an electric supercharger-equipped moving machine <NUM> according to Embodiment <NUM>. As shown in <FIG>, the moving machine <NUM> according to Embodiment <NUM> is a parallel hybrid vehicle on which an electric supercharger SC is mounted. Examples of the moving machine <NUM> include: a straddle-type vehicle (a motorcycle, for example) on which a rider rides; and a four-wheeled utility vehicle which travels on irregular ground.

The traveling drive system <NUM> of the moving machine <NUM> includes an engine E, the supercharger SC, and an electric motor M. The engine E is an internal combustion engine. The engine E serves as a traveling drive source which drives a driving wheel <NUM> (propulsive power generating body) and also serves as an electricity generator drive source. The engine E includes a piston <NUM> and a crank shaft <NUM>. The crank shaft <NUM> rotates in accordance with reciprocation of the piston <NUM>.

The engine E is provided with a throttle device <NUM>, a fuel injection device <NUM>, and an ignition device <NUM>. An intake amount, a fuel supply amount, and an ignition timing are adjusted by controlling the throttle device <NUM>, the fuel injection device <NUM>, and the ignition device <NUM>, and with this, the output of the engine E is adjusted. The supercharger SC includes a supercharger input shaft <NUM> to which power is input from the outside. When the supercharger input shaft <NUM> is driven, the supercharger SC increases intake pressure of the engine E.

The electric motor M includes a motor driving shaft <NUM> which outputs driving power generated by the electric motor M. The electric motor M serves as the traveling drive source which drives the driving wheel <NUM> and also serves as a supercharger power source which drives the supercharger SC. Moreover, the electric motor M serves as an electricity generator which generates electricity by the power from the engine E or the driving wheel <NUM>.

The moving machine <NUM> includes a transmission device TM which changes the speed of rotational power output from the engine E and/or the electric motor M and transmits the power to the driving wheel <NUM>. The transmission device TM is, for example, a manual transmission device which changes the speed in mechanical association with a manual operation of the driver. The transmission device TM includes an input shaft <NUM> (power transmitting shaft), an output shaft <NUM>, and a transmission gear train <NUM>. The driving power output from the engine E and/or the electric motor M is input to the input shaft <NUM>. The transmission gear train <NUM> changes the speed of the rotation of the input shaft <NUM> based on a change gear ratio selected alternatively and transmits the rotation to the output shaft <NUM>. The output shaft <NUM> outputs the rotational power, which has been changed in speed by the transmission gear train <NUM>, to a driving wheel <NUM> through an output transmitting member <NUM> (a chain or a belt, for example).

The driving power of the crank shaft <NUM> of the engine E is input to the input shaft <NUM> through a primary reduction gear <NUM> and a main clutch <NUM> (friction clutch). The main clutch <NUM> is operated by a main clutch actuator <NUM> and cuts or establishes a power transmitting path from the crank shaft <NUM> to the input shaft <NUM>. The crank shaft <NUM>, the primary reduction gear <NUM>, the main clutch <NUM>, the transmission device TM, and the output transmitting member <NUM> constitute a power transmitting path P through which the driving power of the engine E is transmitted to the driving wheel <NUM>.

The motor driving shaft <NUM> of the electric motor M is connected to the supercharger input shaft <NUM> of the supercharger SC. To be specific, the supercharger input shaft <NUM> rotates in association with the rotation of the motor driving shaft <NUM>. The motor driving shaft <NUM> is connected to the input shaft <NUM> through a one-way clutch <NUM>. The one-way clutch <NUM> blocks power transmission from the motor driving shaft <NUM> to the input shaft <NUM> and allows power transmission from the input shaft <NUM> to the motor driving shaft <NUM>.

The one-way clutch <NUM> includes an inner ring and an outer ring. The inner ring of the one-way clutch <NUM> is externally fitted to the input shaft <NUM> so as to rotate together with the input shaft <NUM>. The one-way clutch <NUM> allows the power transmission from the inner ring to the outer ring and blocks the power transmission from the outer ring to the inner ring. The outer ring of the one-way clutch <NUM> is connected to the motor driving shaft <NUM> through a power transmitting mechanism <NUM> (a gear mechanism, a chain-sprocket mechanism, or a belt-pulley mechanism, for example).

The input shaft <NUM> is provided with a switching clutch <NUM> which blocks or allows the power transmission from the electric motor M to the input shaft <NUM>. As one example, the switching clutch <NUM> of the present embodiment is a dog clutch. The switching clutch <NUM> includes a first rotating body <NUM> and a second rotating body <NUM>. The first rotating body <NUM> is connected to the input shaft <NUM> so as to rotate together with the input shaft <NUM> about an axis of the input shaft <NUM> and slide relative to the input shaft <NUM> in an axial direction of the input shaft <NUM>. The second rotating body <NUM> is adjacent to the first rotating body <NUM> and is connected to the outer ring of the one-way clutch <NUM> so as to rotate together with the outer ring of the one-way clutch <NUM> about the axis of the input shaft <NUM>.

The first rotating body <NUM> includes an engaging portion 51a (dog) projecting toward the second rotating body <NUM>. The second rotating body <NUM> includes an engaged portion 52a (dog hole) corresponding to the engaging portion 51a of the first rotating body <NUM>. When the first rotating body <NUM> slides on the input shaft <NUM> to approach the second rotating body <NUM>, and with this, the engaging portion 51a of the first rotating body <NUM> engages with the engaged portion 52a of the second rotating body <NUM>, the second rotating body <NUM> also rotates together with the input shaft <NUM> by the first rotating body <NUM> which rotates together with the input shaft <NUM>. To be specific, the switching clutch <NUM> connects, while bypassing the one-way clutch <NUM>, the input shaft <NUM> to the power transmitting mechanism <NUM> such that two-way power transmission between the input shaft <NUM> and the power transmitting mechanism <NUM> is realized.

When the switching clutch <NUM> is in a disengaged state, the driving power from the motor driving shaft <NUM> through the power transmitting mechanism <NUM> to the input shaft <NUM> is blocked by the one-way clutch <NUM>, and most of the driving power of the motor driving shaft <NUM> is transmitted to the supercharger input shaft <NUM>. When the switching clutch <NUM> is in an engaged state, the driving power of the motor driving shaft <NUM> is input to the input shaft <NUM> through the power transmitting mechanism <NUM> and the switching clutch <NUM>. Thus, the electric motor M can drive the driving wheel <NUM>.

The switching clutch <NUM> is operated by a switching clutch actuator <NUM>. To be specific, by the driving power of the switching clutch actuator <NUM>, the first rotating body <NUM> slides relative to the second rotating body <NUM> in the axial direction of the input shaft <NUM>. The switching clutch actuator <NUM> includes, for example, a shift fork <NUM>, a shift drum <NUM>, and a rotary motor <NUM>. The shift fork <NUM> engages with the first rotating body <NUM> so as not to be displaceable relative to the first rotating body <NUM> in the axial direction of the input shaft <NUM>. The shift drum <NUM> guides the shift fork <NUM> such that the shift fork <NUM> is displaced in the axial direction of the input shaft <NUM>. The rotary motor <NUM> rotates the shift drum <NUM>.

A controller <NUM> is electrically connected to the engine E (the throttle device <NUM>, the fuel injection device <NUM>, and the ignition device <NUM>), the electric motor M, the main clutch actuator <NUM>, and the switching clutch actuator <NUM>. The controller <NUM> is electrically connected to an accelerator operation amount sensor <NUM>, an engine rotational frequency sensor <NUM>, a vehicle speed sensor <NUM>, a user input sensor <NUM>, and the like.

The accelerator operation amount sensor <NUM> detects an accelerator operation amount (acceleration request amount) of the driver. The engine rotational frequency sensor <NUM> detects the rotational frequency of the engine E. The vehicle speed sensor <NUM> detects the traveling speed of the moving machine <NUM>. The user input sensor <NUM> detects a predetermined selection input (a mode switching command, for example) from the driver or the like.

The controller <NUM> includes a processor, a storage, and an I/O interface. The controller <NUM> controls the engine E, the electric motor M, the main clutch actuator <NUM>, and the switching clutch actuator <NUM> in such a manner that the processor refers to information acquired from the sensors <NUM> to <NUM> and the like and performs calculation processing in accordance with a program stored in the storage. It should be noted that the controller <NUM> may be constituted by a single ECU or a plurality of distributed ECUs.

The controller <NUM> determines a driving mode of the moving machine <NUM> based on a mode selection command input from the user input sensor <NUM>. Then, the controller <NUM> controls the engine E, the electric motor M, the main clutch actuator <NUM>, and the switching clutch actuator <NUM> in accordance with the determined driving mode.

It should be noted that the mode selection command does not have to be input from the user input sensor <NUM> and may be generated by the controller <NUM> itself. To be specific, the controller <NUM> may automatically generate the mode selection command based on vehicle states (for example, the rotational frequency of the engine, the traveling speed, a traveling acceleration degree, a gear stage, and a battery remaining amount) and/or driver operation states (for example, the accelerator operation amount, a brake operation amount, and a steering amount).

Next, the types of the driving modes will be described. As the driving modes, there are a normal engine mode, an engine supercharging mode, a HEV mode, an EV mode, an engine start mode, and an electricity generation mode. Hereinafter, these modes will be described with reference to <FIG> in order.

<FIG> shows the normal engine mode. As shown in <FIG>, in the normal engine mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become an engaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the disengaged state, controls the engine E to make the engine E become a driving state based on a detected value of the accelerator operation amount sensor <NUM>, and controls the electric motor M to make the electric motor M become a regenerating state. It should be noted that the control of the main clutch actuator <NUM> when the engine E is driven in each mode may be automatic control or may be performed in accordance with a clutch operation of the driver. The rotational frequency of the engine E is, for example, less than <NUM>,<NUM> rpm.

With this, the driving power of the engine E is transmitted to the driving wheel <NUM> through the primary reduction gear <NUM>, the main clutch <NUM>, the input shaft <NUM>, the transmission gear train <NUM>, the output shaft <NUM>, and the output transmitting member <NUM>. Moreover, the rotational power of the input shaft <NUM> is transmitted to the motor driving shaft <NUM> through the one-way clutch <NUM> and the power transmitting mechanism <NUM>, and with this, the electric motor M serves as an electricity generator (regeneration). The rotation of the motor driving shaft <NUM> is also transmitted to the supercharger input shaft <NUM>. However, since the rotational frequency of the motor driving shaft <NUM> and the rotational frequency of the supercharger input shaft <NUM> are not high (less than <NUM>,<NUM> rpm, for example), the supercharger SC performs weak supercharging. It should be noted that a relief valve configured to release pressure which exceeds a threshold may be provided at a channel located upstream or downstream of the supercharger.

<FIG> shows the engine supercharging mode. As shown in <FIG>, in the engine supercharging mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become the engaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the disengaged state, controls the engine E to make the engine E become the driving state based on the detected value of the accelerator operation amount sensor <NUM>, and controls the electric motor M to make the electric motor M become the driving state. The rotational frequency of the engine E is, for example, less than <NUM>,<NUM> rpm. The electric motor M is driven at a predetermined high rotational frequency (<NUM>,<NUM> to <NUM>,<NUM> rpm, for example) so as to drive the supercharger SC. The rotational frequency of the electric motor M in the engine supercharging mode is higher than each of the rotational frequency of the electric motor M in the below-described HEV mode and the rotational frequency of the electric motor M in the below-described EV mode.

With this, the driving power of the engine E is transmitted to the driving wheel <NUM> through the primary reduction gear <NUM>, the main clutch <NUM>, the input shaft <NUM>, the transmission gear train <NUM>, the output shaft <NUM>, and the output transmitting member <NUM>. Moreover, the electric motor M is driven such that the rotational frequency (<NUM>,<NUM> to <NUM>,<NUM> rpm, for example) of the electric motor M becomes higher than the rotational frequency of the input shaft <NUM>. Therefore, the supercharger input shaft <NUM> is driven by the motor driving shaft <NUM>, and with this, the supercharger SC performs strong supercharging with respect to the engine E.

At this time, the rotational frequency of the power transmitted from the motor driving shaft <NUM> through the power transmitting mechanism <NUM> to the outer ring of the one-way clutch <NUM> is higher than the rotational frequency of the power transmitted from the engine E through the input shaft <NUM> to the inner ring of the one-way clutch <NUM>. Therefore, the power transmission from the motor driving shaft <NUM> to the input shaft <NUM> through the power transmitting mechanism <NUM> is blocked by the one-way clutch <NUM>. To be specific, most of the driving power of the electric motor M is transmitted to the supercharger SC.

<FIG> shows the HEV mode. As shown in <FIG>, in the HEV mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become the engaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the engaged state, controls the engine E to make the engine E become the driving state based on the detected value of the accelerator operation amount sensor <NUM>, and controls the electric motor M to make the electric motor M become the driving state based on the detected value of the accelerator operation amount sensor <NUM>. The rotational frequency of the engine E is, for example, less than <NUM>,<NUM> rpm.

With this, the driving power of the engine E is transmitted to the driving wheel <NUM> through the primary reduction gear <NUM>, the main clutch <NUM>, the input shaft <NUM>, the transmission gear train <NUM>, the output shaft <NUM>, and the output transmitting member <NUM>. Moreover, the driving power of the motor driving shaft <NUM> of the electric motor M is transmitted to the input shaft <NUM> through the power transmitting mechanism <NUM> and the switching clutch <NUM> and then transmitted to the driving wheel <NUM>. To be specific, at the input shaft <NUM>, the driving power of the electric motor M is superimposed on the driving power of the engine E.

Moreover, when the moving machine <NUM> decelerates, the controller <NUM> controls the electric motor M to make the electric motor M become the regenerating state. Therefore, traveling inertial force transmitted from the driving wheel <NUM> to the input shaft <NUM> when the moving machine <NUM> decelerates is transmitted through the switching clutch <NUM> and the power transmitting mechanism <NUM> to the motor driving shaft <NUM>, and with this, the electric motor M generates electricity. The rotation of the motor driving shaft <NUM> is also transmitted to the supercharger input shaft <NUM>. However, since the rotational frequency of the motor driving shaft <NUM> and the rotational frequency of the supercharger input shaft <NUM> are not high (less than <NUM>,<NUM> rpm, for example), the supercharger SC performs weak supercharging.

<FIG> shows the EV mode. As shown in <FIG>, in the EV mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become a disengaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the engaged state, controls the engine E to make the engine E become a stop state, and controls the electric motor M to make the electric motor M become the driving state based on the detected value of the accelerator operation amount sensor <NUM>. The rotational frequency of the electric motor M is, for example, less than <NUM>,<NUM> rpm.

With this, the driving power of the motor driving shaft <NUM> of the electric motor M is transmitted to the input shaft <NUM> through the power transmitting mechanism <NUM> and the switching clutch <NUM> and then transmitted to the driving wheel <NUM>. At this time, since the main clutch <NUM> is in the disengaged state, the engine E is prevented from becoming resistance to the driving of the electric motor M.

Moreover, when the moving machine <NUM> decelerates, the controller <NUM> controls the electric motor M to make the electric motor M become the regenerating state. Therefore, the traveling inertial force transmitted from the driving wheel <NUM> to the input shaft <NUM> when the moving machine <NUM> decelerates is transmitted through the switching clutch <NUM> and the power transmitting mechanism <NUM> to the motor driving shaft <NUM>, and with this, the electric motor M generates electricity. The rotation of the motor driving shaft <NUM> is also transmitted to the supercharger input shaft <NUM>. However, since the rotational frequency of the motor driving shaft <NUM> and the rotational frequency of the supercharger input shaft <NUM> are not high (less than <NUM>,<NUM> rpm, for example), the supercharger SC performs weak supercharging.

<FIG> shows the engine start mode and the electricity generation mode. As shown in <FIG>, in the engine start mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become the engaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the engaged state, controls the electric motor M to make the electric motor M drive in accordance with an engine start command of the driver, and controls the engine E to make the engine E start in accordance with the engine start command. With this, the electric motor M can be made to serve as a starter motor for the engine E, and therefore, a starter motor dedicated for the start of the engine can be omitted.

Moreover, in the electricity generation mode, the controller <NUM> controls the main clutch actuator <NUM> to make the main clutch <NUM> become the engaged state, controls the switching clutch actuator <NUM> to make the switching clutch <NUM> become the engaged state, controls the electric motor M to make the electric motor M become the regenerating state in accordance with an electricity generation command of the driver, and controls the engine E to make the engine E drive at a predetermined rotational frequency in accordance with the electricity generation command. With this, without making the moving machine <NUM> travel, the electric motor M can be made to generate electricity by the driving power of the engine E, and thus, the electricity can be obtained.

According to the above configuration, in the engine supercharging mode in which the intake pressure of the engine E is increased by the supercharger SC, the power generated by the electric motor M is not transmitted to the input shaft <NUM> by the switching clutch <NUM>, and the supercharger SC is appropriately driven. On the other hand, in an electric traveling mode (the HEV mode or the EV mode) in which the electric motor M is used as the traveling drive source, the driving power of the electric motor M is transmitted to the input shaft <NUM> through the switching clutch <NUM>, and the driving power of the electric motor M is transmitted to the driving wheel <NUM>. Therefore, in the moving machine <NUM> equipped with the electric supercharger SC, since the electric motor M which drives the supercharger SC also serves as the traveling drive source, the increase in weight and the deterioration of the degree of freedom of the layout can be suppressed.

Moreover, since the switching clutch <NUM> is a dog clutch arranged around the axis of the input shaft <NUM>, the switching clutch <NUM> is efficiently arranged, and the deterioration of the degree of freedom of the layout can be further suppressed.

When the switching clutch <NUM> is in the disengaged state, the one-way clutch <NUM> blocks the power transmission from the electric motor M to the input shaft <NUM> and allows the power transmission from the input shaft <NUM> to the electric motor M. Therefore, the electric motor M can achieve both a driving function of driving the supercharger SC and a regenerating function of generating electricity by the power of the engine E.

Specifically, in the engine supercharging mode in which the intake pressure of the engine E is increased by the supercharger SC, the driving power generated by the electric motor M is not transmitted to the input shaft <NUM> by the switching clutch <NUM> and the one-way clutch <NUM>, and the supercharger SC is appropriately driven. On the other hand, in a regenerating mode in which the electric motor M is utilized as the electricity generator, the power of the engine E is transmitted from the input shaft <NUM> through the one-way clutch <NUM> to the electric motor M, and the electric motor M generates electricity. Therefore, in the moving machine <NUM> equipped with the electric supercharger SC, an alternator attached to the engine E can be omitted.

According to the configuration in which the one-way clutch <NUM> is provided, in the engine supercharging mode, when the switching clutch <NUM> is in the disengaged state, the power generated by the electric motor M is not transmitted to the input shaft <NUM>, and the supercharger SC is appropriately driven. On the other hand, in the electric traveling mode (the HEV mode or the EV mode) in which the electric motor M is utilized as the traveling drive source, the switching clutch <NUM> becomes the engaged state while bypassing the one-way clutch <NUM>. Therefore, regardless of the existence of the one-way clutch <NUM>, the driving power of the electric motor M is transmitted to the input shaft <NUM>, and therefore, the input shaft <NUM> can be driven by the electric motor M.

<FIG> is a schematic diagram showing a traveling drive system of an electric supercharger-equipped moving machine <NUM> according to Embodiment <NUM>. It should be noted that the same reference signs are used for the same components as in Embodiment <NUM>, and the repetition of the same explanation is avoided. As shown in <FIG>, in the moving machine <NUM> according to Embodiment <NUM>, the one-way clutch <NUM> and the switching clutch <NUM> are arranged around the axis of the motor driving shaft <NUM>, instead of around the axis of the input shaft <NUM>.

The one-way clutch <NUM> and the switching clutch <NUM> are the same in configuration as those in Embodiment <NUM>. The one-way clutch <NUM> blocks the power transmission from the motor driving shaft <NUM> to the power transmitting mechanism <NUM> and allows the power transmission from the power transmitting mechanism <NUM> to the motor driving shaft <NUM>. The switching clutch <NUM> is provided at the motor driving shaft <NUM> so as to block or allow the power transmission from the electric motor M to the power transmitting mechanism <NUM>.

According to this configuration, in the engine supercharging mode, the driving power of the electric motor M is not transmitted to the power transmitting mechanism <NUM> located between the one-way clutch <NUM> and the input shaft <NUM>, and therefore, energy loss can be made smaller than when the one-way clutch <NUM> is provided at the input shaft <NUM>. It should be noted that the other components are the same as those in Embodiment <NUM>, explanations thereof are omitted.

Claim 1:
An electric supercharger-equipped moving machine (<NUM>) comprising:
an engine (E);
a supercharger (SC) configured to increase intake pressure of the engine (E);
an electric motor (M) including a motor driving shaft (<NUM>);
a power transmitting path (P) including a power transmitting shaft (<NUM>) through which driving power of the engine (E) is transmitted to a propulsive power generating body (<NUM>);
a main clutch (<NUM>) through which a driving power of the engine (E) is input to the power transmitting shaft (<NUM>); and
a switching clutch (<NUM>) configured to be able to block power transmission from the electric motor (M) to the power transmitting shaft (<NUM>),
wherein the motor driving shaft (<NUM>) is connected to the supercharger (SC) so as to be able to drive the supercharger (SC) when the switching clutch (<NUM>) is in a disengaged state;
characterized in that the motor driving shaft (<NUM>) is connected to the power transmitting shaft (<NUM>) so as to be able to drive the propulsive power generating body (<NUM>) when the switching clutch (<NUM>) is in an engaged state and the main clutch (<NUM>) is in a disengaged state.