Vehicle seat lift speed variable switch system

A vehicle seat lift speed variable switch system basically has a lift-up mechanism, a control unit and an interface. The lift-up mechanism is configured to selectively lower and lift a vehicle seat between a first position inside a vehicle occupant compartment and a second position outside the vehicle occupant compartment. The control unit is configured to control lowering and lifting movements of the vehicle seat via the lift-up mechanism. The interface is configured to transmit a command signal to the control unit. The interface includes a lift switch and a lift speed variable switch. The control unit is further configured to operate the lift-up mechanism to move the vehicle seat at a predetermined speed when an input is received from only the lift switch, and at a different speed from than the predetermined speed when simultaneous inputs are received from the lift speed variable switch and the lift switch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2006-083670 filed Mar. 24, 2006. The entire disclosure of Japanese Patent Application No. 2006-083670 is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a vehicle seat lift speed variable switch system for a vehicle seat, which switch is used upon assisting an elderly or handicapped person in getting on or off a vehicle by lowering or lifting a vehicle seat.

2. Background Information

Conventionally, there is proposed a mechanism for angular and linear movement of a vehicle seat. This mechanism can move a vehicle seat seated by a vehicle occupant longitudinally within the vehicle occupant compartment to any desired position, and, it can turn the vehicle seat laterally outward and move it through the vehicle door opening downward to a position outside the vehicle occupant compartment when the vehicle occupant wishes to get off the vehicle.

One example of such a conventional vehicle seat device is disclosed in Japanese Laid Open Patent Publication No. 2005-306322. This conventional vehicle seat device employs a mechanism for moving a vehicle seat longitudinally within a vehicle occupant compartment, a mechanism for turning the vehicle seat through about 90 degrees between a position facing forwardly and a position facing a vehicle door opening, and a lift-up mechanism to move the vehicle seat in the position facing the vehicle door opening downward past the vehicle door opening to a position outside the vehicle occupant compartment.

The vehicle seat devices of this kind are required to lift or lower a vehicle seat comparatively slowly to ensure the safety of the seated vehicle occupant. An improvement in safety and reliability is required in mechanisms because there is need for good care of an elderly or handicapped person.

SUMMARY OF THE INVENTION

The conventional vehicle seat devices that are currently available are generally satisfactory. However, a need remains for improvements in safety and in convenience of such vehicle seat device in view of existing requirements that a vehicle seat be lowered or lifted at an increased speed when it is unoccupied or under bad weather conditions and other requirement that the vehicle seat be lowered or lifted at a decreased speed when conditions of the seated person so require.

An object of the present invention is to provide a vehicle seat lift speed variable switch system that provides improvements in safety and in convenience. The vehicle seat lift speed variable switch system of the present invention ensures selection of a speed at which a vehicle seat is lowered or lifted without causing any error in manipulation and ensures that the vehicle seat is moved at the selected variable speed when the vehicle seat is either lowered or lifted.

In order to accomplish the above-mentioned object, a vehicle lift speed variable switch is provided that basically comprises a lift-up mechanism, a control unit and an interface. The lift-up mechanism is configured to selectively lower and lift a vehicle seat between a first position inside a vehicle occupant compartment and a second position outside the vehicle occupant compartment. The control unit is configured to control lowering and lifting movements of the vehicle seat via the lift-up mechanism. The interface is configured to transmit a command signal to the control unit. The interface includes a lift switch and a lift speed variable switch. The control unit is further configured to operate the lift-up mechanism to move the vehicle seat at a predetermined speed when an input is received from only the lift switch, and at a different speed from than the predetermined speed when simultaneous inputs are received from the lift speed variable switch and the lift switch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially toFIG. 1, a vehicle seat device is illustrated employing one embodiment of a vehicle seat lift speed variable switch system that is implemented in a front passenger seat. After backward sliding movement of a vehicle seat1from a position A to a position C via a position B, the vehicle seat1is turned 90 degrees toward an opening covered by a door2. Next, from the position C, the vehicle seat1is moved downward past the opening to a displaced position D outside the vehicle occupant compartment. The vehicle seat1in the displaced position D returns to the position inside the vehicle occupant compartment by reversing the order of the positions A to D.

As shown inFIG. 2, the vehicle seat device comprises a control panel3, a control unit4, a rotary motor5, a slide motor6, a reclining seat motor7, a lift motor8, an angular position sensor9, a slide position sensor10and a reclined position sensor11.

As shown inFIGS. 2 and 7, the control panel3includes a lift switch3a, a lift speed variable switch3b, and a slide switch3c. The lift switch3atransmits a command signal to lower the vehicle seat1or a command signal to lift the vehicle seat1to the control unit4. The lift speed variable switch3bserves as a speed adjustment switch to vary a speed at which the vehicle seat1is lowered or lifted, and also serves as a backrest adjustment switch to adjust an angle of a backrest30as later described. When the lift speed variable switch3bserves as the speed adjustment switch to vary the lower/lift speed of the vehicle seat1, the lift speed variable switch3btransmits a command signal indicating either a high speed movement action of the vehicle seat1or a low speed movement action of the vehicle seat1to the control4. When the lift speed variable switch3bserves as the backrest adjustment switch to adjust the angle of the backrest30, the lift speed variable switch3btransmits a command signal indicating either a forward tilting movement action of the backrest30or a backward tilting movement action of the backrest30to the control unit4. The slide switch3cis a switch to adjust the longitudinal position of the vehicle seat1within the vehicle occupant compartment and transmits a command signal indicating either a forward longitudinal movement action or a backward longitudinal movement action to the control unit4.

The rotary motor5is operated to rotate in response to receiving a command signal transmitted thereto by a motor drive circuit4aof the control unit4. The angular position sensor9detects an angular position of the vehicle seat1. The slide motor6is operated to rotate in response to receiving a command signal transmitted thereto by the motor drive circuit4a. The slide position sensor10detects a slide position of the vehicle seat1. The reclining motor7is operated to rotate in response to receiving a command signal transmitted thereto by the motor drive circuit4a. The relined position sensor11detects a reclined angle of the vehicle seat1. The lift motor8is operated to rotate in response to receiving a command signal transmitted thereto by the motor drive circuit4ain order to assist the seated vehicle occupant getting in or off the vehicle occupant compartment by lifting or lowering the vehicle seat1past the opening uncovered by the door2. A signal processing and arithmetic circuit4bperforms operation processing upon receiving signals from the lift switch3a, the lift speed variable switch3band the slide switch3cand signals from the angular position sensor9, the slide position sensor10and the reclined position sensor11. The signal processing and arithmetic circuit4bthen transmits command signals to the motor5, the slide motor6, the reclining seat motor7and the lift motor8via the motor drive circuit4a.

With regards to the other, there are a slide standard switch that limits a slide width of the vehicle seat1and a reclined position standard switch that limits a reclined angle.

As shown inFIG. 3, a slide mechanism20is provided on a floor of the vehicle at near a driver's seat. The slide mechanism20has a pair of parallel rails21, a slide base22and a driving device. The parallel rails21are fixedly attached on the vehicle floor to extend in a longitudinal direction of the vehicle. The slide base22is moveable in the longitudinal direction of the vehicle due to the parallel rails21. The driving device is disposed between the slide base22and the vehicle floor.

The driving device basically includes a pair of parallel ball screws23mounted on the vehicle floor, the slide motor6for turning the ball screws23, and a pair of nuts25mounted on the slide base22. The ball screws23are threadedly engaged with the nuts25.

The ball screws23revolve when the slide motor6rotates. The revolution of the ball screws23causes the nuts25and the slide base22to move longitudinally. Thus, the rotation mechanism26, the lift-up mechanism34and the vehicle seat1move longitudinally with respect to the vehicle.

As shown inFIG. 4, the rotation mechanism26is mounted on the slide base22. This rotation mechanism26includes a pinion27and an arc-shaped gear28. The pinion27meshes with the arc-shaped gear28.

The pinion27is mounted on the slide base22. The arc-shaped gear28has mounted on its upper side a rotary base. The pinion27is fixedly coupled with an output shaft of the rotary motor5. When the rotary motor5rotates, the arc-shaped shaped gear28rotates, causing the lift-up mechanism34and the vehicle seat1to turn.

Therefore, the vehicle seat1can move longitudinally along the slide rails21by the slide mechanism20and the rotation mechanism26, and the vehicle seat1can turn to shift from a state in which it faces forwardly to a state in which it faces the door opening by activating the rotary motor5.

As shown inFIG. 5andFIG. 6A, the vehicle seat1includes a seat cushion29, a backrest30, and a headrest. The backrest30can tilt backwardly to take at least one reclined positions.

As shown inFIG. 5, a reclining mechanism31is provided that includes a reclining motor7. In response to a signal from the control unit4, a driving gear32turns to change its engagement position with an immovable gear33to adjust an angle of tilt of the backrest30.

As shown inFIGS. 6A and 613, the lift-up mechanism34includes an upper part of a lift-up base35, an outer lift slide rail36and an inner lift slide rail37. Both of the rails36and37extend to secure the length in slide and the vertical difference in lift of the seat1. Both of the rails36and37employ a driving mechanism that includes a driving pulley38that is turned by the lift motor8, and a pair of follower pulleys39and40that guide a belt39. When it turns in a positive rotational direction, the lift motor8changes the intermeshing relationship between the pulleys and belt39to move the vehicle seat1outwardly and downward toward the displaced position outside the vehicle occupant compartment. Subsequently, when it turns in a reverse rotational direction, the lift motor8moves the vehicle seat1inwardly and upward toward the initial position inside the vehicle occupant compartment from the displaced position.

The slide motor6of the slide mechanism20, the rotary motor6of the rotation mechanism26, and the lift motor8of the lift-up mechanism34cooperate with each other to move the vehicle seat1outwardly to the displaced position and to move it from the displaced position outside the vehicle occupant compartment inwardly to the initial position inside the vehicle occupant compartment.

Each of the above-mentioned motors5to8is an electric motor so that a speed of movement of the associated mechanism to the motor can be set by regulating a speed of rotation of the motor. The speed of rotation of a motor can be varied by carrying out PWM drive of the motor and changing the duty ratio or by setting a third brush and varying the number of windings of each electric core of the motor, which technique is used as a mechanism for a wiper motor.

As shown inFIG. 7, the control panel3is designed as one that can be arranged inside the vehicle occupant compartment or near the vehicle seat1. It can be designed as a wire connected or wireless remote controller. The control panel3has the lift switch3a, the lift speed variable switch3band the slide switch3carranged in this order vertically, with the lift switch3a, the ascending switch12and the descending switch13arranged side-by-side. The lift speed variable switch3bincludes a high speed switch14and a low speed switch15that are arranged side-by-side. The slide switch3cincludes a forward-slide switch16and a backward-slide switch17that are arranged side-by-side. In this embodiment, each of the switches12to17transmits a command signal to the control unit4by electrically connecting a pair of contacts with each other when it is pressed. The switches are not limited to the illustrated example. The shape and/or structure of each of the switches12to17may be appropriately set.

In the following, there is description of control of lift speed of the vehicle seat1carried out by the control unit4. Firstly, referring to the flow chart illustrated inFIG. 8, there is description of descending speed determination processing to be carried out when the vehicle seat1lies inside the vehicle occupant compartment.

In step S1, the control unit4determines whether or not there is an input from the descending switch13. If this is the case, then the control proceeds to step S2, and if this is not the case, then the control proceeds to step S3in which the control unit4stops movement of the vehicle seat1.

In step S2, the control unit4determines whether or not there is an input from any one of the high speed switch14and the low speed switch15. If this is the case, then the control proceeds to step S4, and if this is not the case, then the control proceeds to step S5in which the control unit4descends or lowers the vehicle seat1at a predetermined descending speed (for example, 15 cm/second).

In step S4, the control unit4determines whether or not there is an input from the high speed switch14. If this is the case, then the control proceeds to step S6in which the control unit4descends or lowers the vehicle seat1at a speed (for example, 20 cm/second) higher than the predetermined descending speed. If this is not the case, then the control proceeds to step S7in which the control unit4descends or lowers the vehicle seat1at a speed (for example, 10 cm/second) lower than the predetermined descending speed.

Next, referring to the flowchart illustrated inFIG. 9, there is description of ascending speed determination processing to be carried out when the vehicle seat1lies outside the vehicle occupant compartment. In step S10, the control unit4determines whether or not there is an input from the ascending switch12. If this is the case, then the control proceeds to step S20, and if this is not the case, then the control proceeds to step S30in which the control unit4stops movement of the vehicle seat1.

In step S20, the control unit4determines whether or not there is an input from any one of the high speed switch14and the low speed switch15. If this is the case, then the control proceeds to step S40, and if this is not the case, then the control proceeds to step S50in which the control unit4ascends or lifts the vehicle seat1at a predetermined ascending speed (for example, 15 cm/second).

In step S40, the control unit4determines whether or not there is an input from the high speed switch14. If this is the case, then the control proceeds to step S60in which the control unit4ascends or lifts the vehicle seat1at a speed (for example, 20 cm/second) higher than the predetermined ascending speed. If this is not the case, then the control proceeds to step S70in which the control unit4ascends or lifts the vehicle seat1at a speed (for example, 10 cm/second) lower than the predetermined descending speed. The descending and ascending speeds are not limited to this example and can be appropriately set.

Next, there is description of operation of the embodiment. According to the vehicle seat device previously constructed, as shown inFIG. 1, when the vehicle seat1lies inside the vehicle occupant compartment and an operator presses the backward-slide switch17, the vehicle seat1moves backwardly from the position A to the position C.

Next, when the operator presses only the descending switch13, the control unit4carries out jobs inFIG. 8(step S1→step S2→step S5). As a result, the vehicle seat1descends downward at the predetermined descending speed from the position C to the position D at the same time it is turning through about 90 degrees. The vehicle seat1can turn through about 90 degrees before leaving the position C and then it can descend downward.

On the other hands, when the operator presses either the high speed switch14or the low speed switch15at the same time when the operator presses the descending switch13, then the vehicle seat1descends downward at a speed higher than the predetermined descending speed (step S1→step S2→step S4→step S6inFIG. 8) or at a speed lower than the predetermined descending speed (step S1→step S2→step S4→step S7inFIG. 8) from the position C to the position D at the same time it is turning through about 90 degrees toward outside the vehicle. In this case, the vehicle seat1is prevented from descending downward at the speed higher or lower than the predetermined descending speed against the operator's intention unless the operator presses the high speed switch14or the low speed switch15at the same time when the operator presses the descending switch13. Furthermore, movement of the vehicle seat1stops unless the descending switch13is pressed (step S11→step S3inFIG. 8).

Next, when the vehicle seat1lies outside the vehicle occupant compartment and the operator presses only the ascending switch12, the control unit4carries out jobs inFIG. 9(step S10→step S20→step S50). As a result, the vehicle seat1ascends upward at the predetermined descending speed from the position D to the position C at the same time it is turning through about 90 degrees inside the vehicle. The vehicle seat1can turn through about 90 degrees forwardly after ascending near the position C.

Next, when the operator presses the forward-slide switch16, the vehicle seat1moves forwardly from the position C to the position A.

On the other hands, when the operator presses the high speed switch14or the low speed switch15at the same time when the operator presses the ascending switch12, the vehicle seat1ascends upward either at a speed higher than the predetermined descending speed (step S10→step S20→step S40→step S60inFIG. 9) or at a speed lower than the predetermined descending speed (step S10→step S20→step S40→step S70inFIG. 9) from the position D to the position C at the same time it is turning through about 90 degrees inside the vehicle occupant compartment. In this case, the vehicle seat1is prevented from ascending upward at the speed higher or lower than the predetermined ascending speed against the operator's intention unless the operator presses the high speed switch14or the low speed switch15at the same time when the operator presses the ascending switch12. Furthermore, movement of the vehicle seat1stops unless the ascending switch12is pressed (step S10→step S30inFIG. 9).

In addition, when the seated vehicle occupant within the vehicle seat1presses only the high speed switch14or the low speed switch15, the backrest30tilts forwardly or backwardly. The high speed switch14serves as a forward-tilt switch for the backrest30, and the low speed switch15serves as a backward-tilt switch for the backrest30. Of course, it will be apparent to those skilled in the art from this disclosure that the high speed switch14and the low speed switch15can be used for other mechanism as needed and/or desired.

The combinations between each of switches12to15being operated and the speeds at which the vehicle seat1descends and ascends are tabulated in Table 1, as seen below, at switch actions A1 to A6. The action taken when the operator presses only the high speed switch14or the low speed switch16is as described.

When the operator performs operation A1 or A2, the vehicle seat1with seated occupant moves up or down at the predetermined speed with safety ensured. On the other hands, when the vehicle seat1is unoccupied or under bad weather conditions, the vehicle speed1is moved at the speed higher than the predetermined speed with the convenience ensured.

Care for the seated vehicle occupant can be made by moving the vehicle seat1up or down at the speed lower than the predetermined speed by performing operation A5 or A6. Of course, the above-listed operations A1 to A6 can be used for any other appropriate missions.

Next, there is description on the technical effects. As previously described, the vehicle seat lift speed variable switch system according to the present invention basically comprises the lift-up mechanism34, the control unit4and the interface3. The lift-up mechanism34lowers or lifts a vehicle seat1between a first position inside a vehicle occupant compartment and a second position outside the vehicle occupant compartment. The control unit4controls lowering and lifting movements of the vehicle seat1via the lift-up mechanism34. The n interface3transmits a command signal to the control unit4. The interface3including the ascend switch12, the descend switch13, the high speed switch14and the low speed switch15. The control unit4is further configured to operate the lift-up mechanism34to lift the vehicle seat1at a predetermined ascending speed when an input is received from only the ascend switch12. The control unit4is further configured to operate the lift-up mechanism34to lift the vehicle seat1at a high speed that is higher than the predetermined ascending speed when simultaneous inputs are received from the high speed switch14and the ascend switch12. The control unit4is further configured to operate the lift-up mechanism34to lift the vehicle seat1at a low speed that is lower than the predetermined ascending speed when simultaneous inputs are received from the low speed switch15and the ascend switch12. The control unit4is further configured to operate the lift-up mechanism34to lower the vehicle seat1at a predetermined descending speed when an input is received from only the descend switch13. The control unit4is further configured to operate the lift-up mechanism34to lower the vehicle seat1at a high speed that is higher than the predetermined descending speed when simultaneous inputs are received from the high speed switch14and the descend switch13. The control unit4is further configured to operate the lift-up mechanism34to lower the vehicle seat1at a low speed that is lower than the predetermined descending speed when simultaneous inputs are received from the low speed switch15and the descend switch13.

The lift speed variable switch system constructed as above provides improvements in safety and in convenience by allowing selection of a desired ascending/descending speed without any false operation as well as varying the ascending speed and descending speed of the vehicle seat1.

In addition, in the lift speed variable switch system, the high speed switch14and the low speed switch15of the interface3are arranged adjacent to each other (seeFIG. 7), and when there is an input from only selected one of the high speed and low speed switches14and15, the control unit4controls that one of a pair of movements, i.e., a forward-tilt movement and a backward-tilt movement, of a predetermined mechanism, i.e., a reclining mechanism31, set beforehand for the high and low speed switches14and15which is set for the selected one speed switch14or15. In other words, when there is an input from the high speed switch14, the control unit4controls the forward-tilt movement of the reclining mechanism31. On the other hands, when there is an input from the low speed switch15, the control unit4controls the backward-tilt movement of the reclining mechanism31. In the lift speed variable switch system, the high speed switch14and the low speed switch15serve as switches for forward-tilt movement and backward-tilt movement of the reclining mechanism31, reducing the number of switches on the interface3to advance the plan toward miniaturization.

Selecting the adjacent two high and low speed switches14and15to serve as a pair of movements of a predetermined mechanism provides better operability than selecting the switches that are not closely related to each other.

In the preceding description, the present invention has been described in connection with the implementation, but not limited to it. The present invention may contain any design modifications within a range not deviated from the sprint of the subject matter. For example, the present invention may take any appropriate setting of concrete values of the ascending and descending speeds of the vehicle seat1.

In addition, the high and low speed switches14and15can serve as switches not only for forward-tilt and backward-tilt movements of the reclining mechanism31, but also for movements of other mechanism.

Furthermore, speed control of pivotal movement of the vehicle seat1and speed control of sliding movement thereof may be connected with speed control of lift speed of the vehicle seat1.

GENERAL INTERPRETATION OF TERMS