Seat apparatus

In a case where a manipulation switch is manipulated when a limit switch detects the fact that the seat back is in an upright position, an ECU controls driving of a motor until a sector gear turned in a second turning direction moves a lock lever in a lock release direction at a second abutting portion thereby to cause a lock member to be in a lock release state. Also, in a case where the manipulation switch is manipulated when the limit switch detects the fact that the seat back is not in the upright position, the ECU controls driving of the motor until the limit switch detects the fact that the seat back is in the upright position.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2009-220195 filed with the Japan Patent Office on Oct. 28, 2009, the entire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to a seat apparatus in which a seat back can be inclined with respect to a seat cushion.

2. Related Art

As a conventional seat apparatus in which a seat back can be inclined with respect to a seat cushion, a vehicle seat disclosed in Patent Document 1 listed below is known. This vehicle seat includes two manipulating units, i.e., a webbing manipulated for reclining adjustment and a manipulation knob manipulated to incline the seat back forward and fold it over the seat cushion. This seat apparatus is provided with a lock lever having a hook projection engaged with a step portion of a base plate on a free hinge side. Accordingly, the seat back is not inclined forward more than necessary when the webbing is manipulated. This prevents an occupant from feeling cramped between the seat back and the seat cushion when he/she does reclining adjustment while seated.

The document that describes the related art is listed below.

SUMMARY

The above seat apparatus is configured to allow the occupant to manually fold the seat back. Thus, when the seat back in a forward inclined state is moved back to an upright state, the occupant needs to use his/her energy, which bothers the occupant. However, if a motor or the like is merely adopted to motorize (automate) the inclination of the seat back, a complicated configuration including a control unit, and the like is required, which will increase the production cost.

An object of an aspect according to the present invention is to provide a seat apparatus capable of automating inclination of a seat back by a simple configuration.

To achieve the above object, a seat apparatus according to a first aspect of the present invention is a seat apparatus having a seat cushion supported on a floor surface and a seat back attached to, and inclinable relative to, the seat cushion and moved between an upright position and a forward inclined position, including: a biasing member which biases the seat back in a forward inclined direction; a lock mechanism which can lock the seat back not to be relatively inclinable at the upright position; a lock lever which is supported on the seat cushion and switches the lock mechanism between a lock state and a lock release state, and causes the lock mechanism to be in the lock release state by being moved in a lock release direction and causes the lock mechanism to be in the lock state by being moved in a lock direction along with movement of the seat back in the lock release state to the upright position; a gear which is pivotally supported on the seat back, is configured to be turned in a first turning direction corresponding to the forward inclined direction and in a second turning direction, and has a first abutting portion and a second abutting portion, wherein the first abutting portion is set to abut on a stopper fixed in the seat cushion by turning of the gear in the first turning direction while the second abutting portion is set to abut on the lock lever by turning of the gear in the second turning direction thereby to move the lock lever in the lock release direction; a motor which has a motor shaft meshed with the gear and is attached to the seat back, and causes the gear to be turned in the first turning direction by rotating the motor shaft in a first rotating direction and causes the gear to be turned in the second turning direction by rotating the motor shaft in a second rotating direction; a motor controlling unit which controls driving of the motor; a detecting unit which detects whether or not the seat back is in the upright position; and a manipulating unit which is manipulated when the seat back is to be moved to either the upright position or the forward inclined position, wherein, in a case where the manipulating unit is manipulated when the detecting unit detects the fact that the seat back is in the upright position, the motor controlling unit controls driving of the motor and rotates the motor shaft in the second rotating direction until the gear turned in the second turning direction moves the lock lever in the lock release direction at the second abutting portion thereby to cause the lock mechanism to be in the lock release state, and in a case where the manipulating unit is manipulated when the detecting unit detects the fact that the seat back is not in the upright position, the motor controlling unit controls driving of the motor and rotates the motor shaft in the first rotating direction until the detecting unit detects the fact that the seat back is in the upright position.

A seat apparatus according to a second aspect of the present invention is the seat apparatus according to the first aspect, wherein the detecting unit is in contact with a part of the seat back in the upright position, and this contact state is set to be released by inclination of the seat back from the upright position to the forward inclined position, and the detecting unit detects whether or not the seat back is in the upright position based on the contact state.

In the seat apparatus according to the first aspect, in a case where the manipulating unit is manipulated when the detecting unit detects the fact that the seat back is in the upright position, the motor controlling unit controls driving of the motor and rotates the motor shaft in the second rotating direction until the gear turned in the second turning direction moves the lock lever in the lock release direction at the second abutting portion thereby to cause the lock mechanism to be in the lock release state.

When the manipulating unit is manipulated to incline the seat back in the upright position in the forward inclined direction in this manner, the motor shaft is rotated in the second rotating direction. Since this causes the gear to be turned in the second turning direction, the second abutting portion moves the lock lever in the lock release direction. Consequently, the lock mechanism goes into the lock release state. Accordingly, the seat back in the upright position can automatically be inclined in the forward inclined direction by the biasing force of the biasing member.

Also, in a case where the manipulating unit is manipulated when the detecting unit detects the fact that the seat back is not in the upright position, the motor controlling unit controls driving of the motor and rotates the motor shaft in the first rotating direction until the detecting unit detects the fact that the seat back is in the upright position.

When the manipulating unit is manipulated to move back the seat back in the forward inclined position in the upright direction in this manner, the motor shaft is rotated in the first rotating direction. This causes the gear to be turned in the first turning direction to abut on the stopper at the first abutting portion. Thus, even when the motor shaft is further rotated in the first rotating direction, the gear cannot be turned since it is abutting on the stopper. Accordingly, the motor is moved in a direction corresponding to the second turning direction while meshed with the gear. This movement of the motor causes the seat back, to which the motor is attached, to be moved in a direction corresponding to the second turning direction, that is, the upright direction, with respect to the gear. Thus, the seat back in the forward inclined position can automatically be moved in the upright direction against the biasing force of the biasing member.

In particular, the seat apparatus according to the first aspect can be obtained by adding the aforementioned gear, motor, motor controlling unit, and the like to a conventional seat apparatus in which the seat back is manually inclined. Accordingly, inclination of the seat back can be automated by a simple configuration.

In the seat apparatus according to the second aspect, the detecting unit is in contact with a part of the seat back in the upright position. This contact state is set to be released by inclination of the seat back from the upright position to the forward inclined position. That is, the detecting unit is configured to detect whether or not the seat back is in the upright position based on the contact state. Thus, it is possible to detect whether or not the seat back is in the upright position by a simple configuration.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference characters designate similar or identical parts throughout the several views thereof.

Hereinafter, an embodiment of a seat apparatus10according to an aspect of the present invention will be described with reference to the drawings.

The seat apparatus10is mounted to be inclinable in a vehicle as a backseat of the vehicle, for example. The seat apparatus10includes a seat cushion11receiving an occupant's hip and a seat back12receiving the occupant's back as shown inFIG. 1. The seat cushion11is supported on a floor surface. The seat back12is attached to, and inclinable relative to, the seat cushion11and is moved between an upright position and a forward inclined position.

As shown inFIGS. 1 to 3, a seat cushion frame11ais a framework of the seat cushion11. Also, a seat back frame12ais a framework of the seat back12. These frames11aand12aare connected to each other via a connecting shaft21and a lock member22. The lock member22has a function of locking the seat back frame12a, which is in the upright position (position shown inFIGS. 2 and 3), so that the seat back frame12acannot be inclined relative to the seat cushion frame11a. Note that the lock member22corresponds to an example of a “lock mechanism” described in the appended claims.

The seat back frame12ais biased in a forward inclined direction (α2direction inFIGS. 2 and 3) by a spiral spring23arranged around the connecting shaft21. When the lock member22is in a lock release state, the seat back frame12ais inclined in the forward inclined direction by the biasing force of the spiral spring23. Due to this inclination, the seat back12is inclined forward to the seat cushion11. Note that the spiral spring23corresponds to an example of a “biasing member” described in the appended claims.

The lock member22is provided with a lock lever24to switch the lock member22between a lock state and a lock release state. This lock lever24is supported on the seat cushion frame11aand is turnable around the connecting shaft21. The lock lever24is biased to a lock position by a biasing member (not shown) such as a coil spring. The lock lever24is configured to cause the lock member22to be in the lock release state by being moved in a lock release direction against the biasing force. The lock lever24is also configured to cause the lock member22to be in the lock state by being moved in a lock direction by the aforementioned biasing force when the seat back12is moved to the upright position during the lock release state.

Also, the seat apparatus10includes a sector gear25and a motor26for turning this sector gear25. The sector gear25is pivotally supported on the seat back frame12a, around the connecting shaft21as a turning center. This sector gear25is formed to be meshed at its external gear25awith a pinion gear26aprovided at a motor shaft of the motor26at all times. This external gear25ais formed at an approximately semicircular portion of the sector gear25. At a portion opposite the approximately semicircular portion of the sector gear25are formed a first abutting portion25band a second abutting portion25ceach having a planar portion.

The motor26is attached to the seat back frame12a. Rotation of the pinion gear26ain a first rotating direction (β1direction inFIG. 2) causes the sector gear25meshed with the pinion gear26ato be turned in a first turning direction (γ1direction inFIG. 2). When the sector gear25is turned in the first turning direction in this manner, its first abutting portion25babuts on a cylindrical stopper27fixed in the seat cushion frame11a.

Also, rotation of the pinion gear26ain a second rotating direction (β2direction inFIG. 2) causes the sector gear25to be turned in a second turning direction (γ2direction inFIG. 2). When the sector gear25is turned in the second turning direction in this manner, its second abutting portion25cabuts on the lock lever24. As a result, the lock lever24is thrust in the lock release direction. Note that the sector gear25corresponds to an example of a “gear” described in the appended claims.

Also, as shown inFIG. 4, the seat apparatus10includes an ECU31, a limit switch32, and a manipulation switch33. The ECU31is an electronic control unit controlling driving of the motor26by executing after-mentioned inclination processing. The limit switch32is attached to the seat cushion frame11a. As shown inFIG. 5A, when the seat back frame12ais in the upright position, the limit switch32is in contact with, by a lever32a, a moving piece12bwhich is a part of the seat back frame12a. On the other hand, as shown inFIG. 5B, when the seat back frame12ais inclined in the forward inclined direction, the aforementioned contact state between the lever32aand the moving piece12bis released. Thus, the limit switch32plays a role of detecting whether or not the seat back12is in the upright position based on the aforementioned contact state. When the lever32aand the moving piece12bare in the contact state, that is, when the seat back12is in the upright position, the limit switch32outputs a contact signal to the ECU31. Note that the spiral spring23is not shown inFIG. 5Band after-mentionedFIGS. 8B and 8Cfor convenience. Also note that the ECU31corresponds to an example of a “motor controlling unit” described in the appended claims, and that the limit switch32corresponds to an example of a “detecting unit” described in the appended claims.

Also, the manipulation switch33is a single button-type switch manipulated when the seat back12is to be moved to either the upright position or the forward inclined position. This manipulation switch33is arranged at a driver's side door, for example. When pressed by an occupant, the manipulation switch33outputs a manipulation signal to the ECU31. Note that the manipulation switch33corresponds to an example of a “manipulating unit” described in the appended claims.

The ECU31includes a driving circuit to control driving of the motor26. In a case where a manipulation signal is input from the manipulation switch33while a contact signal is input from the limit switch32, the ECU31controls driving of the motor26to rotate the pinion gear26ain the second rotating direction. As a result, the seat back12is inclined to the forward inclined position. In contrast, in a case where the manipulation signal is input from the manipulation switch33when no contact signal is input from the limit switch32, the ECU31controls driving of the motor26to rotate the pinion gear26ain the first rotating direction. As a result, the seat back12is moved to the upright position.

Next, seat inclination processing by the ECU31will be described with reference toFIGS. 6 to 9.

In a case where an occupant wishes to incline the seat back12to the forward inclined position when the seat back12is in the upright position shown inFIGS. 7A and 8Afor the purpose of baggage loading or the like, he/she presses the manipulation switch33. Accordingly, the ECU31makes a determination of Yes at Step5101inFIG. 6. Subsequently, whether or not a contact signal has been input from the limit switch32is determined at Step S103.

At this stage, the lever32aof the limit switch32and the moving piece12bare in the contact state. Thus, the contact signal has been input from the limit switch32to the ECU31. Accordingly, the ECU31makes a determination of Yes at Step S103. Subsequently, driving processing is performed at Step S105. In this manner, the control of driving of the motor26causes the pinion gear26ato be rotated in the second rotating direction (β2direction inFIG. 7A).

Accordingly, the sector gear25meshed with the pinion gear26ais turned in the second turning direction (γ2direction inFIG. 7A), and its second abutting portion25cabuts on the lock lever24. Then, when the pinion gear26ais further rotated in the second rotating direction, along with which the sector gear25is further turned in the second turning direction, the lock lever24is thrust in the lock release direction by the second abutting portion25c. Consequently, the lock member22goes into the lock release state.

Next, whether or not the lock member22is in the lock release state is determined at Step S107. When the lock member22is in the lock release state as described above (Yes in S107), processing to stop rotation of the motor is performed at Step S113. Processing from Step S101to Step S113is repeated until the power is turned off (until the ECU31makes a determination of Yes at Step S115). Note that, in the determination processing at Step S107, whether or not the lock member22is in the lock release state is determined by estimation of the turning position of the sector gear25based on the rotating position of the pinion gear26acalculated in accordance with pulses output from the motor26. In addition to this, however, whether or not the lock member22is in the lock release state may also be determined in accordance with a lapse of estimated time considered necessary for the lock member22to be in the lock release state, for example. Also, whether or not the lock member22is in the lock release state may be determined based on the shutoff of input of the contact signal from the limit switch32.

When the lock member22is in the lock release state as described above, the seat back12as well as the seat back frame12ais automatically inclined in the forward inclined direction (α2direction inFIGS. 7B and 8B) by the biasing force of the spiral spring23. Since the limit switch32is attached to the seat cushion frame11a, the contact between the lever32aof the limit switch32and the moving piece12bof the seat back frame12ais released. As a result, input of the contact signal from the limit switch32to the ECU31is shut off.

When the seat back12is inclined to the forward inclined position, the seat back frame12aabuts on a frame stopper11b. Accordingly, the aforementioned inclination is stopped (refer toFIGS. 7C and 8C).

On the other hand, in a case where the occupant wishes to move back the seat back12in the forward inclined position shown inFIG. 9Ato the upright position, he/she presses the manipulation switch33. Accordingly, the ECU31makes a determination of Yes at Step S101inFIG. 6. Subsequently, whether or not the contact signal has been input from the limit switch32is determined at Step S103.

At this stage, the contact signal from the limit switch32is shut off. Accordingly, the ECU31makes a determination of No at Step S103. Subsequently, driving processing is performed at Step S109. In this manner, the control of driving of the motor26causes the pinion gear26ato be rotated in the first rotating direction (β1direction inFIG. 9A).

Accordingly, the sector gear25meshed with the pinion gear26ais turned in the first turning direction (γ1direction inFIG. 9A), and its first abutting portion25babuts on the stopper27. Then, when the pinion gear26ais further rotated in the first rotating direction, the sector gear25is to be further turned in the first turning direction along with the further rotation. However, the sector gear25cannot be turned since it is abutting on the stopper27. Instead, therefore, the motor26moves in a direction corresponding to the second turning direction while meshed with the sector gear25.

This movement of the motor26causes the seat back frame12a, to which the motor26is attached, to be moved in a direction corresponding to the second turning direction, that is, the upright direction (α1direction inFIG. 9B), with respect to the sector gear25. Thus, the seat back12in the forward inclined position can automatically be moved toward the upright position against the biasing force of the spiral spring23by the driving force of the motor26, as shown inFIG. 9B.

Then, when the seat back12is moved to the upright position as shown inFIG. 9C, the lever32aof the limit switch32and the moving piece12bof the seat back frame12aare in the contact state. Thus, the contact signal is input from the limit switch32to the ECU31. Accordingly, the ECU31makes a determination of Yes at Step S111. Subsequently, processing to stop rotation of the motor is performed at Step S113.

As described above, in the seat apparatus10according to the present embodiment, in a case where the manipulation switch33is manipulated when the limit switch32detects the fact that the seat back12is in the upright position, the ECU31controls driving of the motor26and rotates the pinion gear26ain the second rotating direction until the sector gear25turned in the second turning direction moves the lock lever24in the lock release direction at the second abutting portion25cthereby to cause the lock member22to be in the lock release state.

When the manipulation switch33is manipulated to incline the seat back12in the upright position in the forward inclined direction in this manner, the pinion gear26ais rotated in the second rotating direction. Since this causes the sector gear25to be turned in the second turning direction, the second abutting portion25cmoves the lock lever24in the lock release direction. Consequently, the lock member22goes into the lock release state. Accordingly, the seat back12in the upright position can automatically be inclined in the forward inclined direction by the biasing force of the spiral spring23.

Also, in a case where the manipulation switch33is manipulated when the limit switch32detects the fact that the seat back12is not in the upright position, the ECU31controls driving of the motor26and rotates the pinion gear26ain the first rotating direction until the limit switch32detects the fact that the seat back12is in the upright position.

When the manipulation switch33is manipulated to move back the seat back12in the forward inclined position in the upright direction in this manner, the pinion gear26ais rotated in the first rotating direction. This causes the sector gear25turned in the first turning direction to abut on the stopper27at the first abutting portion25b. Thus, the motor26is moved in a direction corresponding to the second turning direction while meshed with the sector gear25. This causes the seat back12, to which the motor26is attached, to be moved in a direction corresponding to the second turning direction, that is, the upright direction, with respect to the sector gear25. Thus, the seat back12in the forward inclined position can automatically be moved in the upright direction against the biasing force of the spiral spring23.

In particular, the seat apparatus according to an aspect of the present invention can be obtained by adding the aforementioned sector gear25, motor26, ECU31, and the like to a conventional seat apparatus in which the seat back12is manually inclined. Accordingly, inclination of the seat back can be automated by a simple configuration.

Also, the seat apparatus10according to the present embodiment includes the limit switch32for detecting whether or not the seat back12is in the upright position. This limit switch32is in contact with, by its lever32a, the moving piece12bof the seat back12in the upright position. The contact state is set to be released by inclination of the seat back12from the upright position to the forward inclined position. In other words, the limit switch32is configured to detect whether or not the seat back12is in the upright position based on the contact state. Accordingly, in this seat apparatus10, whether or not the seat back12is in the upright position can be detected by a simple configuration.

Note that the present invention is not limited to the above embodiment but may be embodied in the following manner. In this case as well, similar effects to those of the above embodiment can be obtained.(1) In the above embodiment, a gear such as an external gear or an internal gear may be adopted instead of the sector gear25. In this case, such a gear is provided with abutting portions corresponding to the first abutting portion25band the second abutting portion25cat portions other than tooth portions. In this case as well, similar effects to those in the case of adopting the sector gear25can be obtained.(2) The seat apparatus10may also be adopted as a seat mounted in a vehicle or the like, not only as a backseat of a vehicle.

While the invention has been illustrated and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the spirit and scope of the invention.