Vehicle seat

Abstract

[Problem] To provide a vehicle seat in which it is easy to rotate of a seat back between a stored position where the seat back is collapsed and an upright position where the seat back is upright. [Solution] A vehicle seat 1 including a support device 6 provided on the floor F of a vehicle 2, a seat back 4 supported by the support device 6 so as to be rotatable between the stored position and the upright position, and a lock device 8 for maintaining the seat back 4 in the upright position. The support device 6 includes: a rotating member 12 that is rotatably supported by a base member 11 coupled to the floor F, and is coupled to the seat back 4; an electric actuator 13; a transmission mechanism 14 that transmits driving force of the electric actuator 13 to the rotating member 12, and a spring 15 that is provided between the base member 11 and the rotating member 12 and biases the seat back 4 toward the stored position. The electric actuator 13 is configured to rotate the seat back 4 from the stored position to the upright position and to be rotatable when power is not supplied.

Description

Vehicle seats

[0001] The present invention relates to a vehicle seat.

[0002] A vehicle seat that can rotate between a reclined position and an upright position is known. For example, Patent Document 1 describes a vehicle seat that has a seat cushion provided on the floor of the vehicle and a seat back that is attached to the vehicle body and can rotate between the reclined position and the upright position.

[0003] Japanese Patent Application Laid-Open No. 2023-127989

[0004] However, in the vehicle seat described in Patent Document 1, the seat back must be rotated manually between the stowed position and the upright position, which can be laborious. For example, in the vehicle seat described in Patent Document 1, in order to rotate the seat back from the stowed position to the upright position, the seat back must be manually lifted against the force of gravity. Therefore, there is a demand for a vehicle seat whose seat back can be easily rotated between the stowed position and the upright position.

[0005] In view of the above background, an object of the present invention is to provide a vehicle seat in which the seat back can be easily rotated between a reclined storage position and an upright position.

[0006] In order to solve the above problem, one aspect of the present invention is a vehicle seat (1), comprising: a support device (6) provided on a floor (F) of a vehicle (2); a seat back (4) supported by the support device so as to be rotatable between a storage position and an upright position; and a locking device (8) provided on the seat back and detachably connected to a connecting member (10) provided on a side wall of the vehicle, for maintaining the seat back in the upright position. The support device comprises a base member (11) connected to the floor; a rotating member (12) rotatably supported on the base member and connected to the seat back; an electric actuator (13) provided on the base member; a transmission mechanism (14) for transmitting the driving force of the electric actuator to the rotating member; and a spring (15) provided between the base member and the rotating member for biasing the seat back to the storage position. The electric actuator is driven by receiving a supply of electric power to rotate the seat back from the storage position to the upright position, and is configured to be rotatable when no electric power is supplied.

[0007] According to this aspect, the vehicle seat can rotate the seat back from the stowed position to the upright position using the driving force of the electric actuator, and can also rotate the seat back from the stowed position to the upright position using the biasing force of the spring. Therefore, the seat back can be easily rotated between the stowed position and the upright position. This makes it possible to provide a vehicle seat in which the seat back can be easily rotated between the stowed position where the seat back is reclined and the upright position where the seat back is upright.

[0008] In the above aspect, the rotating member has a spring support portion (33) connected to one end (15A) of the spring, the base member has a stopper pin (26), the spring is connected to the spring support portion at the one end and has an engaged portion (15C) on the other end (15B) side that can engage with the stopper pin, and the stopper pin is arranged to engage with the engaged portion of the spring when the seat back is positioned between a bias start position that is between the storage position and the upright position and the storage position.

[0009] According to this aspect, the spring is compressed more greatly as the seat back moves from the bias start position toward the upright position, so that the vehicle seat can reliably bias the seat back from the upright position toward the stowed position.

[0010] In the above aspect, the rotating member has a spring engaging portion (34) that can engage with the other end (15B) of the spring, and when the seat back is positioned between the storage position and the bias start position, the spring is connected to the spring support portion of the rotating member at one end of the spring and is maintained in a compressed state by engaging with the spring engaging portion of the rotating member at the other end of the spring, and when the seat back is positioned between the bias start position and the upright position, the spring is connected to the spring support portion of the rotating member at one end of the spring and is compressed by engaging the engaged portion of the spring with the stopper pin of the base member.

[0011] According to this aspect, when the seat back is positioned between the stowed position and the bias start position, the spring is not engaged with the stopper pin of the base member, and therefore the spring does not bias the seat back to the stowed position. By not biasing the seat back to the stowed position when the seat back is positioned between the stowed position and the bias start position, it is possible to easily rotate the seat back from the stowed position to the bias start position.

[0012] In the above aspect, the rotating member may have a pressure-receiving pin (35), and the transmission mechanism may have an arm portion that presses the pressure-receiving pin in a direction in which the seat back rotates from the storage position to the upright position.

[0013] According to this aspect, the pressure-receiving pin of the rotating member and the arm portion of the transmission mechanism are not integrated. Therefore, when the seat back is manually rotated from the stowed position to the upright position, the rotating member rotates with the pressure-receiving pin of the rotating member and the arm portion of the transmission mechanism separated. This allows the rotating member to rotate together with the seat back without rotating the electric actuator. Therefore, when manually rotating the seat back from the stowed position to the upright position, the seat back can be rotated from the stowed position to the upright position without applying force to rotate the electric actuator. This makes it easy to manually rotate the seat back from the stowed position to the upright position.

[0014] In the above aspect, the rotating member has the pressure-receiving pin, and a first plate portion (31) and a second plate portion (32) that support the pressure-receiving pin and face each other with a gap between them, the second plate portion has connecting portions (32B, 32C, 32D) that extend toward the first plate portion and are connected to the first plate portion, and the pressure-receiving pin, the first plate portion, and the second plate portion cooperate to form a closed cross-sectional structure.

[0015] According to this aspect, the pressure-receiving pin, the first plate portion, and the second plate portion cooperate to form a closed cross-sectional structure, thereby increasing the rigidity of the rotating member.

[0016] In the above aspect, the control device may include a control device (51) connected to the electric actuator and controlling the drive of the electric actuator, the support device being supported by the base member and having a position determination sensor (16) that detects whether the rotating member is in a first position corresponding to the storage position, the control device being connected to the position determination sensor, and upon receiving a stand-up signal including a stand-up command to rotate the seat back to the stand-up position, the control device acquires an output of the position determination sensor and determines whether the position of the seat back is in the stand-up position based on the output of the position determination sensor, and if it determines that the position of the seat back is in the stand-up position, drives the electric actuator to rotate the seat back from the stand-up position to the stand-up position, and if it determines that the position of the seat back is not in the stand-up position, it may not drive the electric actuator.

[0017] According to this aspect, the control device drives the electric actuator to rotate the seat back from the stowed position to the upright position when the seat back is in the stowed position. Furthermore, the control device does not drive the electric actuator when the seat back is not in the stowed position and therefore is considered to be in the upright position. This allows the electric actuator to be appropriately driven to rotate the seat back from the stowed position to the upright position.

[0018] In the above aspect, the control device may be connected to the locking device and configured to control the locking device to switch between a locked state in which the connection between the locking device and the connecting member is maintained and an unlocked state in which the locking device can be detached from the connecting member.

[0019] According to this aspect, the seat back can be easily rotated from the upright position to the stowed position.

[0020] In order to solve the above problem, one aspect of the present invention is a vehicle seat (1), comprising: a support device (6) provided on a floor (F) of a vehicle (2); a seat back (4) supported by the support device so as to be rotatable between a storage position and an upright position; and a locking device (8) provided on the seat back and detachably connected to a connecting member (10) provided on a side wall of the vehicle, for maintaining the seat back in the upright position. The support device comprises a base member (11) connected to the floor; a rotating member (12) rotatably supported on the base member and connected to the seat back; an electric actuator (13) provided on the base member; a transmission mechanism (14) for transmitting the driving force of the electric actuator to the rotating member; and a spring (15) provided between the base member and the rotating member for biasing the seat back to the storage position. The electric actuator is driven by receiving a supply of electric power to rotate the seat back from the storage position to the upright position, and is configured to be rotatable when no electric power is supplied.

[0021] According to this aspect, the vehicle seat can rotate the seat back from the stowed position to the upright position using the driving force of the electric actuator, and can also rotate the seat back from the stowed position to the upright position using the biasing force of the spring. Therefore, the seat back can be easily rotated between the stowed position and the upright position. This makes it possible to provide a vehicle seat in which the seat back can be easily rotated between the stowed position where the seat back is reclined and the upright position where the seat back is upright.

[0022] In the above aspect, the rotating member has a spring support portion (33) connected to one end (15A) of the spring, the base member has a stopper pin (26), the spring is connected to the spring support portion at the one end and has an engaged portion (15C) on the other end (15B) side that can engage with the stopper pin, and the stopper pin is arranged to engage with the engaged portion of the spring when the seat back is positioned between a bias start position that is between the storage position and the upright position and the storage position.

[0023] According to this aspect, the spring is compressed more greatly as the seat back moves from the bias start position toward the upright position, so that the vehicle seat can reliably bias the seat back from the upright position toward the stowed position.

[0024] In the above aspect, the rotating member has a spring engaging portion (34) that can engage with the other end (15B) of the spring, and when the seat back is positioned between the storage position and the bias start position, the spring is connected to the spring support portion of the rotating member at one end of the spring and is maintained in a compressed state by engaging with the spring engaging portion of the rotating member at the other end of the spring, and when the seat back is positioned between the bias start position and the upright position, the spring is connected to the spring support portion of the rotating member at one end of the spring and is compressed by engaging the engaged portion of the spring with the stopper pin of the base member.

[0025] According to this aspect, when the seat back is positioned between the stowed position and the bias start position, the spring is not engaged with the stopper pin of the base member, and therefore the spring does not bias the seat back to the stowed position. By not biasing the seat back to the stowed position when the seat back is positioned between the stowed position and the bias start position, it is possible to easily rotate the seat back from the stowed position to the bias start position.

[0026] In the above aspect, the rotating member may have a pressure-receiving pin (35), and the transmission mechanism may have an arm portion that presses the pressure-receiving pin in a direction in which the seat back rotates from the storage position to the upright position.

[0027] According to this aspect, the pressure-receiving pin of the rotating member and the arm portion of the transmission mechanism are not integrated. Therefore, when the seat back is manually rotated from the stowed position to the upright position, the rotating member rotates with the pressure-receiving pin of the rotating member and the arm portion of the transmission mechanism separated. This allows the rotating member to rotate together with the seat back without rotating the electric actuator. Therefore, when manually rotating the seat back from the stowed position to the upright position, the seat back can be rotated from the stowed position to the upright position without applying force to rotate the electric actuator. This makes it easy to manually rotate the seat back from the stowed position to the upright position.

[0028] In the above aspect, the rotating member has the pressure-receiving pin, and a first plate portion (31) and a second plate portion (32) that support the pressure-receiving pin and face each other with a gap between them, the second plate portion has connecting portions (32B, 32C, 32D) that extend toward the first plate portion and are connected to the first plate portion, and the pressure-receiving pin, the first plate portion, and the second plate portion cooperate to form a closed cross-sectional structure.

[0029] According to this aspect, the pressure-receiving pin, the first plate portion, and the second plate portion cooperate to form a closed cross-sectional structure, thereby increasing the rigidity of the rotating member.

[0030] In the above aspect, the control device may include a control device (51) connected to the electric actuator and controlling the drive of the electric actuator, the support device being supported by the base member and having a position determination sensor (16) that detects whether the rotating member is in a first position corresponding to the storage position, the control device being connected to the position determination sensor, and upon receiving a stand-up signal including a stand-up command to rotate the seat back to the stand-up position, the control device acquires an output of the position determination sensor and determines whether the position of the seat back is in the stand-up position based on the output of the position determination sensor, and if it determines that the position of the seat back is in the stand-up position, drives the electric actuator to rotate the seat back from the stand-up position to the stand-up position, and if it determines that the position of the seat back is not in the stand-up position, it may not drive the electric actuator.

[0031] According to this aspect, the control device drives the electric actuator to rotate the seat back from the stowed position to the upright position when the seat back is in the stowed position. Furthermore, the control device does not drive the electric actuator when the seat back is not in the stowed position and therefore is considered to be in the upright position. This allows the electric actuator to be appropriately driven to rotate the seat back from the stowed position to the upright position.

[0032] In the above aspect, the control device may be connected to the locking device and configured to control the locking device to switch between a locked state in which the connection between the locking device and the connecting member is maintained and an unlocked state in which the locking device can be detached from the connecting member.

[0033] According to this aspect, the seat back can be easily rotated from the upright position to the stowed position.

[0034] 6 is a perspective view of a vehicle seat according to a first embodiment;

[0023] FIG. 1 is a perspective view of a support device, a support member, a locking device, and a seat back frame in a seat back in an upright position;

[0024] FIG. 2 is a perspective view of a support device, a support member, a locking device, and a seat back frame in a seat back in a stowed position;

[0025] FIG. 3 is a schematic cross-sectional view of a locking device in an unlocked state;

[0026] FIG. 4 is a schematic cross-sectional view of a locking device in a locked state;

[0027] FIG. 5 is a perspective view of a support device when the seat back frame is in an upright position;

[0028] FIG. 6 is a perspective view of a support device when the seat back frame is in an upright position, as viewed from an angle different from that of FIG. 6;

[0029] FIG. 7 is a perspective view of a support device when the seat back frame is in an upright position;

[0029] FIG. 8 is a block diagram of a system related to a vehicle seat;

[0029] FIG. 9 is a graph showing the correspondence between the rotation angle θ formed between the seat back frame (seat back) and a floor, and the detection by a position determination sensor and the biasing force of a spring to the seat back;

[0029] FIG. 10 is a side view showing a main part of the support device when the rotation member is in a first position corresponding to the stowed position, and the arm portion is separated from the pressure-receiving pin. 1 is a side view showing a main part of the support device when the rotating member is located at a first position corresponding to the storage position and the arm portion is in contact with the pressure-receiving pin. 2 is a side view showing a main part of the support device when the engaged portion of the spring is engaged with the stopper pin and the outer end of the spring is engaged with the spring engaging portion. 3 is a side view showing a main part of the support device when the rotating member 12 is located at a second position corresponding to the standing position. 4 is a flowchart of the standing position rotation process. 5 is a flowchart of the storage position rotation process.

[0035] Hereinafter, with reference to the drawings, an embodiment in which a vehicle seat 1 according to an embodiment of the present invention is applied to an automobile 2 (vehicle) will be described. The automobile 2 is one example of a vehicle, and the vehicle seat 1 may also be applied to vehicles such as an airplane or a ship. In the drawings and the following description, the front-to-rear direction, the left-to-right direction, and the up-to-down direction are directions defined based on the position of an occupant seated in the vehicle seat 1. Furthermore, the inward direction of the seat (or the seat inner side) is the direction toward the center of the vehicle seat 1 in the left-to-right direction (also referred to as the seat width direction) when viewed from the front. The outward direction of the seat (or the seat outer side) is the direction away from the center of the vehicle seat 1 in the left-to-right direction.

[0036] <Configuration of Vehicle Seat 1> Fig. 1 is a perspective view of a vehicle seat 1 according to an embodiment. As shown in Fig. 1, the vehicle seat 1 is provided on a floor F at the rear of an automobile 2. The vehicle seat 1 includes a seat cushion 3, a seat back 4, a headrest 5, a support device 6 and a support member 7 (see Fig. 2) that support the seat back 4 so that the seat back 4 can rotate between a stowed position and an upright position, and a locking device 8 (see Fig. 2) that maintains the seat back 4 in the upright position. The stowed position is the position of the seat back 4 when the seat back 4 is folded forward. The upright position is the position of the seat back 4 when the seat back 4 is upright.

[0037] The seat cushion 3 is provided on the floor F and supports the buttocks of an occupant. The seat cushion 3 has a seat cushion frame (not shown) that forms the skeleton, a pad (not shown) supported by the seat cushion frame, and a skin material 3A that covers the surface of the pad.

[0038] The seat back 4 extends upward from the rear of the seat cushion 3 and supports the back of the occupant. The seat back 4 has a seat back frame 9 that forms the skeleton, a pad (not shown) supported by the seat back frame 9, and a skin material 4A that covers the surface of the pad. The headrest 5 is provided on the upper part of the seat back 4 and supports the head of the occupant.

[0039] The support device 6 and the support member 7 support the seat back frame 9 rotatably between a storage position and an upright position. The storage position of the seat back 4 and the seat back frame 9 is the position of the seat back 4 and the seat back frame 9 when the seat back 4 and the seat back frame 9 are in a forward tilted state. The upright position of the seat back 4 and the seat back frame 9 is the position of the seat back 4 and the seat back frame 9 when the seat back 4 and the seat back frame 9 are in an upright state.

[0040] Figure 2 is a perspective view of the support device 6, support member 7, locking device 8, and seat back frame 9 in the seat back 4 when it is in the upright position. Figure 3 is a perspective view of the support device 6, support member 7, locking device 8, and seat back frame 9 in the seat back 4 when it is in the stowed position. As shown in Figure 2, the seat back frame 9 is formed in a rectangular frame shape. The seat back frame 9 bears the weight of a seated occupant. The seat back frame 9 has left and right side portions 9A extending vertically, an upper portion 9B extending horizontally and connected to the upper ends of the left and right side portions 9A, and a lower portion 9C extending horizontally and connected to the lower ends of the left and right side portions 9A.

[0041] The support device 6 and support member 7 are provided on the floor F of the automobile 2. The configuration of the support device 6 will be described in detail below. The support member 7 has a fixed seat portion 7A connected to the floor F and a plate portion 7B connected to the fixed seat portion 7A and extending upward from the fixed seat portion 7A. The plate portion 7B is screwed to the fixed seat portion 7A. The plate portion 7B is rotatably connected to the lower end of the left side portion 9A of the seat back frame 9, and rotatably supports the left side portion 9A.

[0042] The locking device 8 is provided at the upper end of the right side portion 9A of the seat back frame 9. As shown in Figures 2 and 3, a striker 10 (connecting member) that is detachably connected to the locking device 8 is provided on the side wall of the automobile 2. The locking device 8 can be switched between a locked state in which the connection between the locking device 8 and the striker 10 can be maintained, and an unlocked state in which the locking device 8 can be detached from the striker 10.

[0043] The striker 10 is disposed in a position where it can be coupled with the locking device 8 on the seat back 4 when it is in the upright position. The positions of the locking device 8 and the striker 10 can be changed. For example, the locking device 8 may be provided at the upper end of the left side portion 9A of the seat back frame 9. The locking device 8 may be provided in the vertical center of the right side portion 9A, or in the vertical center of the left side portion 9A.

[0044] Fig. 4 is a schematic cross-sectional view of the locking device 8 in an unlocked state. Fig. 5 is a schematic cross-sectional view of the locking device 8 in a locked state. As shown in Figs. 4 and 5, the locking device 8 has a case 8B having an opening 8A through which the striker 10 projects, a cam 8C that releasably engages with the striker 10 projecting into the opening 8A, and an electric motor 8E whose drive shaft is connected to a rotation shaft 8D of the cam 8C and that rotates the cam 8C.

[0045] As shown in FIGS. 2 and 3 , when the seat back frame 9 rotates from the stowed position to the upright position, the striker 10 enters the opening 8A of the locking device 8. As shown in FIG. 4 , when the striker 10 enters the opening 8A and presses the cam 8C, the cam 8C rotates, and the cam 8C enters a locked state in which it is engaged with the striker 10, as shown in FIG. 5 . This connects the striker 10 to the locking device 8, maintaining the seat back 4 in the upright position. Furthermore, in the locked state shown in FIG. 5 , the electric motor 8E can rotate the cam 8C to the position shown in FIG. 4 to enter an unlocked state in which the engagement between the cam 8C and the striker 10 is released. In this way, by rotating the cam 8C with the electric motor 8E, the locking device 8 can be changed from the locked state (see FIG. 5 ) to the unlocked state (see FIG. 4 ). In the unlocked state, the seat back 4, which is in the upright position, can be rotated from the upright position to the stowed position.

[0046] <Configuration of Support Device 6> Figure 6 is a perspective view of the support device 6 when the seatback frame 9 is in the upright position. Figure 7 is a perspective view of the support device 6 when the seatback frame 9 is in the upright position, as viewed from an angle different from that of Figure 6. As shown in Figures 6 and 7, the support device 6 includes a base member 11 connected to the floor F, a rotating member 12 connected to the seatback frame 9, an electric motor 13 (electric actuator), a transmission mechanism 14 that transmits the driving force of the electric motor 13 to the rotating member 12, a spring 15 (see Figure 8) that biases the seatback 4 to the stowed position, and a position determination sensor 16 that detects the position of the rotating member 12. As shown in Figures 6 and 7, the rotating member 12 is rotatably supported by the base member 11 and connected to the seatback frame 9.

[0047] The base member 11 has a fixed seat 21 fixed to the floor F, a standing wall portion 22 rising from the fixed seat 21, a right reinforcing plate portion 23 extending to the right from the standing wall portion 22, a left reinforcing plate portion 24 extending to the left from the standing wall portion 22, and a cylindrical rotating shaft portion 25 (see Figure 9) and a stopper pin 26 (see Figure 7) extending to the left (inside the seat) from the standing wall portion 22.

[0048] The fixed seat 21 is formed in the shape of a plate with its surfaces facing up and down and is connected to the floor F. The rear of the fixed seat 21 may be screwed to the floor F with bolts and nuts. The standing wall portion 22 is formed in the shape of a plate with its surfaces facing left and right. The right reinforcing plate portion 23 rises from the fixed seat 21 and extends to the right (outside the seat) from the front end of the standing wall portion 22, and is formed in the shape of a plate with its surfaces facing forward and backward. The left reinforcing plate portion 24 rises from the fixed seat 21 and extends to the left (inside the seat) from the rear end of the standing wall portion 22, and is formed in the shape of a plate with its surfaces facing forward and backward. The standing wall portion 22 is reinforced by the right reinforcing plate portion 23 and the left reinforcing plate portion 24.

[0049] The rotation shaft portion 25 (see FIG. 9 ) is formed in a cylindrical shape extending leftward (toward the seat interior) from the center in the front-to-rear direction and the center in the up-to-down direction of the standing wall portion 22. The rotation member 12 rotates around the rotation shaft portion 25. The stopper pin 26 is formed in a cylindrical shape extending leftward (toward the seat interior) from the upper side of the rear portion of the standing wall portion 22 of the base member 11. The stopper pin 26 is disposed on the outer periphery of the rotation shaft portion 25 (the rotation shaft of the rotation member 12).

[0050] Fig. 8 is an exploded perspective view of the rotating member 12. As shown in Fig. 8, the rotating member 12 has a first plate portion 31 and a second plate portion 32 that face each other with a gap between them, a spring support portion 33 and a spring engagement portion 34 that support the spring 15, a pressure-receiving pin 35 that is coupled to the first plate portion 31 and the second plate portion 32, and a support plate 36 that supports the seat back frame 9.

[0051] The first plate portion 31 has a hole 31A through which the rotary shaft portion 25 is inserted and a hole 31B through which the pressure-receiving pin 35 is inserted. The first plate portion 31 is rotatably supported by the rotary shaft portion 25 via the hole 31A. The first plate portion 31 is also coupled to the pressure-receiving pin 35 via the hole 31B.

[0052] As shown in Fig. 6, the second plate portion 32 is disposed between the first plate portion 31 and the standing wall portion 22 of the base member 11. As shown in Fig. 8, the second plate portion 32 has a hole 32A through which the rotating shaft portion 25 is inserted, a first connecting portion 32B, a second connecting portion 32C, and a third connecting portion 32D (see Fig. 6) that extend toward the first plate portion 31 at the outer periphery and are connected to the first plate portion 31, and a hole 32E through which the pressure-receiving pin 35 is inserted. The second plate portion 32 is rotatably supported by the rotating shaft portion 25 via the hole 32A.

[0053] The first connecting portion 32B extends further left (toward the seat interior) than the second plate portion 32 and is connected to the support plate 36. The first connecting portion 32B and the support plate 36 are fastened together by screws. The first connecting portion 32B and the support plate 36 may be welded and further fastened together by screws.

[0054] The second connecting portion 32C is disposed in a position close to the first connecting portion 32B. The plate thickness direction of the second connecting portion 32C is oriented in a direction intersecting the plate thickness direction of the first connecting portion 32B. As shown in Fig. 6, the third connecting portion 32D is disposed at the end of the second plate portion 32 opposite to the first connecting portion 32B side.

[0055] As shown in FIG. 8, a pressure-receiving pin 35 is inserted into the hole 32E and is coupled to the pressure-receiving pin 35.

[0056] The spring support portion 33 is connected to the right side (outside of the seat) of the second plate portion 32 and is formed in a plate shape extending along the outer periphery of the hole 32A. The spring support portion 33 is connected to the inner end portion 15A (one end portion) of the spring 15.

[0057] The spring engaging portion 34 has a plate-shaped connecting portion 34A whose surface connected to the right side (outside the seat) of the second plate portion 32 faces left and right, and a plate-shaped engaging plate portion 34B extending rightward (outside the seat) from the end of the connecting portion 34A. The engaging plate portion 34B of the spring engaging portion 34 can engage with the outer end portion 15B (other end portion) of the spring 15. Furthermore, as shown in FIG. 7 , the spring engaging portion 34 may be separated from the outer end portion 15B of the spring 15.

[0058] As shown in Fig. 8, the pressure-receiving pin 35 is inserted through and coupled to the hole 31B of the first plate portion 31 and the hole 32E of the second plate portion 32. As shown in Fig. 6, the first plate portion 31, the second plate portion 32, and the pressure-receiving pin 35 cooperate to form a closed cross-sectional structure. This increases the rigidity of the rotating member 12. The pressure-receiving pin 35 is also positioned close to the third connecting portion 32D. Therefore, the third connecting portion 32D can effectively resist the load received by the pressure-receiving pin 35.

[0059] The support plate 36 has a plate-shaped portion 36A connected to the first connecting portion 32B, and a connecting portion 36B extending leftward (toward the seat interior) from the plate-shaped portion 36A and connected to the right side portion 9A of the seatback frame 9. The connecting portion 36B is formed in a curved plate shape so as to fit closely to the right side portion 9A of the seatback frame 9.

[0060] As shown in Figure 7, the electric motor 13 is provided on the right side (outside the seat) of the standing wall portion 22 of the base member 11. As will be described later, the electric motor 13 is driven by receiving a supply of electric power to rotate the seat back 4 from the stowed position to the upright position, and is configured to be rotatable when no electric power is supplied. The electric motor 13 is an example of an electric actuator. Instead of the electric motor 13, a hydraulic electric actuator having a hydraulic cylinder or the like may be used.

[0061] 9 is a perspective view of the transmission mechanism 14 when the seat back frame 9 is in the upright position. As shown in FIG. 9, the transmission mechanism 14 includes a gear box 41 (see FIG. 7) attached to the electric motor 13, a gear 42 connected to the gear box 41, a gear 43 meshing with the gear 42, a pressing gear 45 meshing with the gear 43 and having an arm portion 44, and a support portion 46 that rotatably supports the gear 42. The gear 42 is rotatably supported by the vertical wall portion 22 and the support portion 46 of the base member 11. The support portion 46 is connected to the vertical wall portion 22 and rotatably supports the gear 42. The arm portion 44 extends radially outward from the pressing gear 45.

[0062] The electric motor 13 (electric actuator) and the transmission mechanism 14 do not have a self-locking function. The self-locking function is a function that realizes that while it is easy to rotate the output side (pressure gear 45 in the transmission mechanism 14) by rotating the input side (electric motor 13), it is not easy to rotate the input side (electric motor 13) by rotating the output side (pressure gear 45 in the transmission mechanism 14). Because the electric motor 13 and the transmission mechanism 14 do not have a self-locking function, when power is not supplied to the electric motor 13, the electric motor 13 and the transmission mechanism 14 (including the gear box 41, gear 42, gear 43, arm portion 44, and pressure gear 45) can rotate easily.

[0063] As shown in FIG. 8 , the spring 15 has an inner end 15A, an outer end 15B, and an engaged portion 15C bent at the outer end 15B side (the other end) so that the spring 15 is folded back. The spring 15 is a spiral spring whose inner end 15A is coupled to the spring support portion 33 and whose outer end 15B is engageable with the spring engaging portion 34. The spring 15 is configured so that when the inner end 15A is coupled to the spring support portion 33 of the rotating member 12 and the outer end 15B is engaged with the spring engaging portion 34 of the rotating member 12, the spring 15 is compressed. The engaged portion 15C of the spring 15 may engage with the stopper pin 26 of the base member 11. In this manner, the spring 15 is disposed between the base member 11 and the rotating member 12 and biases the seat back frame 9 (seat back 4) toward the stowed position, as described below. The spring 15 may be a torsion coil spring.

[0064] As shown in FIG. 9 , the position determination sensor 16 is rotatably supported on the front end of the upright wall portion 22 of the base member 11. The position determination sensor 16 includes a detection arm portion 16A that is pressed against the pressure-receiving pin 35, and a determination unit (not shown) that detects the rotation of the detection arm portion 16A as a result of being pressed against the pressure-receiving pin 35. As will be described later, when the rotating member 12 is located in a first position corresponding to the storage position, the detection arm portion 16A is pressed against the pressure-receiving pin 35, and the determination unit detects that the detection arm portion 16A has been pressed. This allows the position determination sensor 16 to detect that the rotating member 12 is located in the first position corresponding to the storage position (i.e., that the seat back 4 is in the storage position). In this way, the position determination sensor 16 detects whether the seat back 4 is in the storage position and outputs a signal. The detection arm portion 16A is located to the left of the arm portion 44, and the arm portion 44 does not press against the detection arm portion 16A. The position determination sensor 16 may be a switch that turns on when the detection arm portion 16A is pressed by the pressure-receiving pin 35.

[0065] Figure 10 is a perspective view of the support device 6 when the seat back frame 9 is in the stowed position. As will be described in detail later, the seat back 4 is rotated from the stowed position to the upright position by the driving force of the electric motor 13. Also, the driving force of the electric motor 13 rotates the rotating member 12 from a first position (see Figure 10) corresponding to the stowed position to a second position (see Figure 6) corresponding to the upright position. The electric motor 13 and the transmission mechanism 14 are configured to be rotatable when power is not supplied to the electric motor 13.

[0066] Although the details will be described later, when the seat back 4 is in the upright position, the spring 15 biases the seat back 4 toward the stowed position. That is, when the seat back 4 is in the upright position, the spring 15 biases the rotating member 12 in a direction from the second position toward the first position.

[0067] 11 is a block diagram of a system related to the vehicle seat 1. As shown in FIG. 11, the automobile 2 is provided with a control device 51 and an input / output device 52 that transmits and receives information to the control device 51. The control device 51 is connected to the electric motor 8E of the locking device 8, the electric motor 13, and the position determination sensor 16.

[0068] The control device 51 can supply power to the electric motor 8E of the locking device 8 and control the driving of the electric motor 8E. The control device 51 can control the locking device 8 to switch between a locked state (see FIG. 5) in which the connection between the locking device 8 and the striker 10 is maintained and an unlocked state (see FIG. 4) in which the locking device 8 can be disengaged from the striker 10 by causing the electric motor 8E to rotate a cam 8C (see FIG. 4).

[0069] The control device 51 can supply power to the electric motor 13 and control the driving of the electric motor 13. That is, the control device 51 can drive the electric motor 13 to rotate the seat back 4 from the stowed position to the upright position. Furthermore, the position determination sensor 16 outputs information indicating whether or not the rotating member 12 is in a first position corresponding to the stowed position (whether or not the seat back 4 is in the stowed position) to the control device 51. The control device 51 can detect whether or not the seat back 4 is in the stowed position based on the output of the position determination sensor 16.

[0070] The control device 51 can execute an upright position rotation process (see FIG. 17) for rotating the seat back 4 to an upright position and a storage position rotation process (see FIG. 18) for rotating the seat back 4 to a storage position.

[0071] The control device 51 is a computer having a processor and a memory communicatively connected to the processor. The processor may include, for example, at least one of a CPU, a GPU, and an MPU as a core. The memory stores programs executed by the processor and various data. The memory may include at least one of a volatile memory and a non-volatile memory. The volatile memory may be, for example, a DRAM or an SRAM. The non-volatile memory may be an SSD, a flash memory, a magnetic disk storage device, or an optical disk storage device. At least a portion of the control device 51 may be realized by hardware such as an LSI, an ASIC, or an FPGA, or may be realized by a combination of software and hardware. The control device 51 may be configured by a single piece of hardware, or may be configured by multiple pieces of hardware that can communicate with each other.

[0072] The input / output device 52 includes an upright position rotation button (not shown) for rotating the seat back 4 to the upright position, and a storage position rotation button (not shown) for rotating the seat back 4 to the storage position. The upright position rotation button and the storage position rotation button of the input / output device 52 may be buttons displayed on a touch panel. The upright position rotation button and the storage position rotation button of the input / output device 52 may be mechanical switches independent of the touch panel. When the upright position rotation button is pressed, the input / output device 52 outputs an operation signal (stand up signal) including a stand up command to rotate the seat back 4 to the upright position to the control device 51. Furthermore, when the storage position rotation button is pressed, the input / output device 52 outputs an operation signal (storage signal) including a storage command to rotate the seat back 4 to the storage position to the control device 51.

[0073] <Rotation of Seat Back 4> A user can manually rotate the seat back 4 between the stowed position and the upright position. In addition, the user can rotate the seat back 4 from the stowed position to the upright position by driving the electric motor 13. In this case, as described below, the driving force of the electric motor 13 is transmitted to the rotating member 12 via the transmission mechanism 14, and the rotating member 12 is biased by the spring 15 to the stowed position.

[0074] As shown in FIG. 8 , in the rotating member 12, the first plate portion 31, the second plate portion 32, the spring support portion 33, the spring engagement portion 34, the pressure-receiving pin 35, and the support plate 36 are integrally connected. The spring support portion 33 is also connected to the inner end portion 15A of the spring 15. The support plate 36 is also connected to the seat back frame 9 (see FIG. 6 ). Therefore, the inner end portion 15A of the spring 15 connected to the spring support portion 33, the spring engagement portion 34, the pressure-receiving pin 35, and the seat back frame 9 supported by the support plate 36 rotate integrally around the rotation axis of the rotating shaft portion 25. That is, the inner end portion 15A of the spring 15, the spring engagement portion 34, the pressure-receiving pin 35, and the seat back frame 9 rotate integrally around the rotation axis of the rotating shaft portion 25.

[0075] 9, the driving force of the electric motor 13 is transmitted to the pressing gear 45 of the transmission mechanism 14, and the arm portion 44 of the pressing gear 45 presses the pressure-receiving pin 35 of the rotating member 12. Therefore, the driving force of the electric motor 13 causes the arm portion 44 to press the pressure-receiving pin 35, and the inner end portion 15A of the spring 15, the spring engaging portion 34, the pressure-receiving pin 35, and the seat back frame 9 rotate integrally around the rotation axis of the rotating shaft portion 25 (clockwise in FIG. 9). As a result, the seat back 4 rotates in the direction of rotation from the stowed position to the upright position, and the rotation angle θ between the seat back frame 9 and the floor F increases.

[0076] 12 is a graph showing the correspondence between the rotation angle θ between the seat back frame 9 (seat back 4) and the floor F, the detection by the position determination sensor 16, and the biasing force of the spring 15 to the seat back 4. As shown in FIG. 12, the rotation angle θ between the seat back frame 9 (seat back 4) and the floor F increases as the seat back 4 rotates from the stored position to the upright position.

[0077] FIG. 13 is a side view showing a main portion of the support device 6 when the rotating member 12 is located at a first position corresponding to the storage position and the arm portion 44 is separated from the pressure-receiving pin 35. As shown in FIG. 13, the seat back 4 may be located at the storage position and the pressure-receiving pin 35 may be separated from the arm portion 44. In this case, the rotating member 12 is located at the first position, so that the pressure-receiving pin 35 of the rotating member 12 presses the detection arm portion 16A. As a result, the position determination sensor 16 detects that the rotating member 12 is located at the first position corresponding to the storage position. When the electric motor 13 is driven in the state shown in FIG. 13, the arm portion 44 rotates together with the pressing gear 45 of the transmission mechanism 14, and the arm portion 44 rotates in a direction approaching the pressure-receiving pin 35, and the arm portion 44 comes into contact with the pressure-receiving pin 35.

[0078] 14 is a side view showing the main parts of the support device 6 when the rotating member 12 is located at the first position corresponding to the storage position and the arm portion 44 is in contact with the pressure-receiving pin 35. As shown in Fig. 14, even when the seat back 4 is located at the storage position and the pressure-receiving pin 35 is in contact with the arm portion 44, the rotating member 12 is located at the first position, so the pressure-receiving pin 35 of the rotating member 12 presses the detection arm portion 16A. Therefore, the position determination sensor 16 detects that the rotating member 12 is located at the first position corresponding to the storage position.

[0079] 14, when the electric motor 13 is driven, the arm portion 44 of the transmission mechanism 14 rotates, and the arm portion 44 presses the pressure-receiving pin 35, separating the detection arm portion 16A from the pressure-receiving pin 35. The pressure-receiving pin 35 and the seat back frame 9 rotate together around the rotation axis of the rotating shaft portion 25 (clockwise in FIG. 14), and the rotation angle θ between the seat back frame 9 and the floor F increases.

[0080] The rotation angle θ formed between the seat back frame 9 and the floor F when the pressure-receiving pin 35 and the detection arm portion 16A are separated is called the "rotation angle θ1" (see FIG. 9). When the rotation angle θ is less than the rotation angle θ1 (see FIG. 9), the position determination sensor 16 detects that the rotating member 12 is located at the first position corresponding to the storage position. On the other hand, when the rotation angle θ is equal to or greater than the rotation angle θ1 (see FIG. 9), the position determination sensor 16 detects that the rotating member 12 is not located at the first position corresponding to the storage position.

[0081] In addition, the pressure-receiving pin 35 is further pressed against the arm portion 44, and the inner end portion 15A of the spring 15, the spring engaging portion 34, the pressure-receiving pin 35, and the seat back frame 9 rotate together, so that the engaged portion 15C of the spring 15 engages with the stopper pin 26, and the outer end portion 15B of the spring 15 engages with the spring engaging portion 34.

[0082] 15 is a side view showing the main parts of the support device 6 when the engaged portion 15C of the spring 15 is engaged with the stopper pin 26 and the outer end 15B of the spring 15 is engaged with the spring engaging portion 34. In the state shown in FIG. 15 where the engaged portion 15C of the spring 15 is engaged with the stopper pin 26 and the outer end 15B of the spring 15 is engaged with the spring engaging portion 34, the rotation angle θ formed by the seat back frame 9 and the floor F is called the "rotation angle θ2" (see FIG. 9), and the position of the seat back 4 is called the "bias start position."

[0083] The inner end 15A of the spring 15, the spring engaging portion 34, the pressure-receiving pin 35, and the seat back frame 9 rotate together around the rotation axis of the rotating shaft portion 25 (clockwise in FIG. 15 ). Therefore, when the rotating member 12 further rotates from the state in which the seat back 4 is in the bias start position (rotation angle θ = rotation angle θ2) shown in FIG. 15 , the engagement between the engaged portion 15C of the spring 15 and the stopper pin 26 is maintained, and the outer end 15B of the spring 15 moves away from the spring engaging portion 34. Here, the spring 15 is compressed by being coupled at the inner end 15A to the spring support portion 33 of the rotating member 12 (see FIG. 8 ) and by being engaged at the engaged portion 15C of the spring 15 with the stopper pin 26 of the base member 11.

[0084] When the electric motor 13 is further driven from the state shown in FIG. 15, the arm portion 44 presses the pressure-receiving pin 35, and the rotating member 12 rotates to the second position corresponding to the upright position.

[0085] 16 is a side view showing the main parts of the support device 6 when the rotating member 12 is in the second position corresponding to the standing position. The rotation angle θ formed between the seat back frame 9 and the floor F when the rotating member 12 is in the second position shown in FIG. 16 is called "rotation angle θ3" (see FIG. 9).

[0086] 14, when the rotation angle θ is equal to or less than the rotation angle θ2 (rotation angle θ≦rotation angle θ2), the seat back 4 is positioned between the stowed position and the bias start position. When the seat back 4 is positioned between the stowed position and the bias start position, the inner end 15A of the spring 15 is connected to the spring support portion 33 of the rotating member 12, and the outer end 15B is engaged with the spring engaging portion 34 of the rotating member 12, so that the spring 15 is maintained in a compressed state.

[0087] On the other hand, as shown in FIG. 16 , when the rotation angle θ is greater than the rotation angle θ2 and less than or equal to the rotation angle θ3 (rotation angle θ2<rotation angle θ≦rotation angle θ3), the seat back 4 is positioned between the bias start position and the upright position. When the seat back 4 is positioned between the bias start position and the upright position, the spring 15 is compressed by coupling the inner end 15A to the spring support portion 33 of the rotating member 12 and engaging the stopper pin 26 of the base member 11 at the engaged portion 15C. Here, the spring 15 is compressed more significantly as the seat back 4 moves toward the bias start position and the upright position. In this case, the spring 15 is compressed more than when the seat back 4 is positioned between the stowed position and the bias start position. Furthermore, because the spring 15 is engaged with the stopper pin 26 of the base member 11 at the engaged portion 15C, the spring 15 biases the seat back frame 9 together with the rotating member 12 toward the stowed position. That is, when the seat back 4 is positioned between the biasing start position and the upright position, the spring 15 biases the seat back 4 to the stowed position.

[0088] The stopper pin 26 is positioned so as to engage with the engaged portion 15C of the spring 15 when the seat back 4 is positioned between the bias start position, which is between the storage position and the upright position, and the storage position.

[0089] As shown in Figure 16, when the seat back 4 is in the upright position, as the seat back 4 rotates toward the upright position, as described above with reference to Figures 2 to 5, the striker 10 provided on the side wall of the automobile 2 enters the opening 8A of the locking device 8 provided on the seat back frame 9, causing the cam 8C to rotate, and as shown in Figure 5, the striker 10 and the locking device 8 are engaged. This maintains the seat back 4 in the upright position. The electric motor 8E can rotate the cam 8C.

[0090] When the seat back 4 is in the upright position and the locking device 8 is in the locked state, if the cam 8C of the locking device 8 rotates from the position shown in Figure 5 (the position for the locked state) to the position shown in Figure 4 (the position for the unlocked state), the connection between the striker 10 and the locking device 8 is released, and the seat back 4 rotates from the upright position to the stowed position due to the force of the spring 15.

[0091] When the seat back 4 is in the upright position, the seat back 4 is maintained in the upright position due to the engagement between the locking device 8 and the striker 10. When the seat back 4 is positioned between the upright position and the stowed position, gravity acting on the seat back 4 causes the seat back 4 to rotate toward the stowed position. Also, when the seat back 4 is in the stowed position, gravity acting on the seat back 4 maintains the seat back 4 in the stowed position. Therefore, the seat back 4 is considered to be in either the upright position or the stowed position.

[0092] When the electric motor 13 is driven to rotate the seat back 4 from the storage position to the upright position (see FIGS. 13 to 16 ), and then the seat back 4 is rotated from the upright position to the storage position, the seat back 4, the rotating member 12, the transmission mechanism 14 (particularly the arm portion 44 and the pressing gear 45), and the electric motor 13 rotate in the direction opposite to the rotation direction described using FIGS. 13 to 16 . That is, together with the rotating seat back 4, the seat back frame 9 and the rotating member 12 (including the pressure-receiving pin 35) rotate integrally around the rotation axis of the rotating shaft portion 25 (counterclockwise in FIG. 16 ). As a result, the pressure-receiving pin 35 presses the arm portion 44 and the pressing gear 45, causing the arm portion 44 and the pressing gear 45 to rotate around the rotation axis of the rotating shaft portion 25 (counterclockwise in FIG. 16 ). Furthermore, the rotational force of the pressure gear 45 is transmitted to the gear box 41 and the electric motor 13, causing the electric motor 13 to rotate.

[0093] In this way, when the electric motor 13 is driven to rotate the seat back 4 from the stowed position to the upright position (see FIGS. 13 to 16 ) and then the seat back 4 is rotated from the upright position to the stowed position, the electric motor 13 rotates in accordance with the rotation of the seat back 4. Furthermore, because the electric motor 13 and the transmission mechanism 14 do not have a self-locking function, the electric motor 13 and the transmission mechanism 14 (including the gear box 41, gear 42, gear 43, arm portion 44, and pressing gear 45) can rotate easily when no power is supplied to the electric motor 13. Therefore, when the seat back 4 is rotated from the upright position to the stowed position, the electric motor 13 and the transmission mechanism 14 do not hinder the rotation of the seat back 4.

[0094] <Processing of Control Device 51> Next, with reference to FIGS. 17 and 18, the standing position rotation process (FIG. 17) and the storage position rotation process (FIG. 18) executed by the control device 51 will be described.

[0095] 17 is a flowchart of the standing position rotation process. When the standing position rotation button is pressed, the input / output device 52 outputs a standing signal including a standing command to rotate the seat back 4 to the standing position to the control device 51. When the control device 51 receives the standing signal from the input / output device 52, it executes the standing position rotation process.

[0096] 17 , in the first step ST1 of the standing position rotation process, the control device 51 acquires the output of the position determination sensor 16. After acquiring the output of the position determination sensor 16, the control device 51 executes step ST2. The position determination sensor 16 detects whether the seat back 4 is in the stowed position based on whether the detection arm portion 16A is pressed against the pressure-receiving pin 35, and outputs the result to the control device 51.

[0097] In step ST2, the control device 51 determines whether or not the seat back 4 is in the stowed position based on the output of the position determination sensor 16. If the control device 51 determines that the seat back 4 is not in the stowed position (ST2: No), the seat back 4 is in the upright position and it is considered that there is no need to rotate the seat back 4 to the upright position, so the upright position rotation process is terminated. If the control device 51 determines that the seat back 4 is in the stowed position (ST2: Yes), the seat back 4 is in the stowed position and it is considered that there is no need to rotate the seat back 4 to the upright position, so ST3 is executed.

[0098] In step ST3, the control device 51 supplies power to the electric motor 13 to cause the electric motor 13 to generate driving force, thereby rotating the seat back 4 from the stored position to the upright position, as described above using Figures 12 to 16.

[0099] 18 is a flowchart of the storage position rotation process. When the storage position rotation button is pressed, the input / output device 52 outputs a storage signal including a storage command to rotate the seat back 4 to the storage position to the control device 51. When the control device 51 receives the storage signal from the input / output device 52, it executes the storage position rotation process.

[0100] 18 , in the first step ST11 of the storage position rotation process, the control device 51 acquires the output of the position determination sensor 16. After acquiring the output of the position determination sensor 16, the control device 51 executes step ST2. Based on the output of the position determination sensor 16, the control device 51 detects whether the seat back 4 is in the storage position.

[0101] In step ST12, the control device 51 determines whether the seat back 4 is in the stowed position. If the control device 51 determines that the seat back 4 is in the stowed position (ST2: YES), the seat back 4 is in the stowed position and it is considered that there is no need to rotate the seat back 4 to the stowed position, so the stowed position rotation process is terminated. On the other hand, if the control device 51 determines that the seat back 4 is not in the stowed position (ST12: No), it is considered that the seat back 4 is in the upright position and it is considered that there is a need to rotate the seat back 4 to the stowed position, so ST13 is executed. In this case, it is considered that the seat back 4 is in the upright position and the locking device 8 is in a locked state in which it is engaged with the striker 10.

[0102] In step ST13, the control device 51 supplies power to the electric motor 8E of the locking device 8 to rotate the cam 8C from the position shown in Fig. 5 to the position shown in Fig. 4, thereby bringing the locking device 8 into an unlocked state (see Fig. 4) in which it can be disengaged from the striker 10. In the unlocked state, the connection between the striker 10 and the locking device 8 is released, and the seat back 4 is rotated from the upright position to the stowed position by the bias of the spring 15.

[0103] <Method of Manufacturing Support Device 6> The method of manufacturing the support device 6 includes a base member preparation step of preparing a base member 11, a motor assembling step of assembling the electric motor 13 and the transmission mechanism 14 to the base member 11, a rotating member preparation step of preparing a rotating member 12, a spring assembling step of assembling the spring 15 to the rotating member 12, and a rotating member assembling step of assembling the rotating member 12 with the spring 15 assembled to the base member 11 with the electric motor 13 and the transmission mechanism 14 assembled. The order of performing the base member preparation step, the motor assembling step, the motor assembling step, the spring assembling step, and the rotating member assembling step can be changed.

[0104] <Method of Mounting Vehicle Seat 1 and Support Device 6> The method of mounting the vehicle seat 1 and support device 6 to an automobile 2 (vehicle) includes a base mounting step of mounting the fixed seat 21 of the base member 11 to the floor F, and a seat back frame mounting step of mounting the seat back frame 9 to the support plate 36. The order of performing the base mounting step and the seat back frame mounting step can be changed.

[0105] <Advantages of Vehicle Seat 1> Next, advantages of the vehicle seat 1 will be described.

[0106] The vehicle seat 1 has a spring 15 that biases the seat back 4 to the stowed position, and an electric motor 13 that rotates the seat back 4 from the stowed position to the upright position. As a result, the vehicle seat 1 can rotate the seat back 4 from the stowed position to the upright position using the driving force of the electric motor 13, and can also rotate the seat back 4 from the stowed position to the upright position using the biasing force of the spring 15. Therefore, the seat back 4 can be easily rotated between the stowed position and the upright position. This makes it possible to provide a vehicle seat 1 in which the seat back 4 can be easily rotated between the stowed position in which the seat back 4 is reclined and the upright position in which the seat back 4 is upright.

[0107] The spring 15 is coupled at its inner end 15A (one end) to the spring support portion 33, and has at its outer end 15B (other end) an engaged portion 15C that can engage with the stopper pin 26. The stopper pin 26 is also arranged to engage with the engaged portion 15C of the spring 15 when the seat back 4 is positioned between the biasing start position and the stowed position. As a result, the spring 15 is compressed more greatly as the seat back 4 moves from the biasing start position toward the upright position. Therefore, the vehicle seat 1 can reliably bias the seat back 4 from the upright position toward the stowed position.

[0108] When the seat back 4 is positioned between the stowed position and the bias start position, the spring 15 engages with the spring engaging portion 34 of the rotating member 12 at the outer end 15B. When the seat back 4 is positioned between the bias start position and the upright position, the spring 15 is coupled with the spring support portion 33 of the rotating member 12 at the inner end 15A and engages with the stopper pin 26 of the base member 11 at the engaged portion 15C. Therefore, when the seat back 4 is positioned between the stowed position and the bias start position, the spring 15 is not engaged with the stopper pin 26 of the base member 11, and therefore the spring 15 does not bias the seat back 4 toward the stowed position. When the seat back 4 is positioned between the stowed position and the bias start position, the spring 15 does not bias the seat back 4 toward the stowed position, which makes it easier to rotate the seat back 4 from the stowed position to the bias start position.

[0109] Furthermore, when the seat back 4 is positioned between the stowed position and the biasing start position, the spring 15 is maintained in a compressed state. The further the seat back 4 moves from the biasing start position toward the upright position, the more the spring 15 is compressed. As a result, the spring 15 is compressed more when the seat back 4 is in the upright position than when the rotating member 12 does not have the spring engaging portion 34, so the spring 15 can more strongly bias the seat back 4 in the upright position toward the stowed position. Therefore, the vehicle seat 1 can reliably bias the seat back 4 in the upright position toward the stowed position.

[0110] The transmission mechanism 14 has an arm portion 44 that presses the pressure-receiving pin 35 in a direction in which the seat back 4 rotates from the stowed position to the upright position. Because the pressure-receiving pin 35 of the rotating member 12 and the arm portion 44 of the transmission mechanism 14 are not integral, when the seat back 4 is manually rotated from the stowed position to the upright position, the rotating member 12 rotates with the pressure-receiving pin 35 of the rotating member 12 and the arm portion 44 of the transmission mechanism 14 separated from each other. This allows the rotating member 12 to rotate together with the seat back 4 without rotating the electric motor 13. Therefore, when manually rotating the seat back 4 from the stowed position to the upright position, the seat back 4 can be rotated from the stowed position to the upright position without applying a force to rotate the electric motor 13. This makes it easy to manually rotate the seat back 4 from the stowed position to the upright position.

[0111] The pressure-receiving pin 35, the first plate portion 31, and the second plate portion 32 cooperate to form a closed cross-sectional structure, which can increase the rigidity of the rotating member 12.

[0112] When the control device 51 determines that the position of the seat back 4 is in the stowed position (ST2: Yes in FIG. 17 ), it drives the electric motor 13 to rotate the seat back 4 from the stowed position to the upright position (ST3 in FIG. 17 ). On the other hand, when the control device 51 determines that the position of the seat back 4 is not in the stowed position (ST2: No in FIG. 17 ), it does not drive the electric motor 13. Therefore, the control device 51 drives the electric motor 13 to rotate the seat back 4 from the stowed position to the upright position when the seat back 4 is in the stowed position. Furthermore, the control device 51 does not drive the electric motor 13 when the seat back 4 is not in the stowed position and therefore is considered to be in the upright position. This allows the electric motor 13 to be appropriately driven to rotate the seat back 4 from the stowed position to the upright position.

[0113] The control device 51 can control the locking device 8 to switch between a locked state and an unlocked state. Therefore, when the seat back 4 is in the upright position and the locking device 8 is in the locked state, the control device 51 can switch from the locked state to the unlocked state and rotate the seat back 4 from the upright position to the stowed position. Therefore, it is possible to easily rotate the seat back 4 from the upright position to the stowed position.

[0114] A spring 15 is provided to bias the seat back 4 to the stowed position in order to rotate the seat back 4 from the stowed position to the upright position. When rotating the seat back 4 from the stowed position to the upright position, it is necessary to rotate the seat back 4 from the stowed position to the upright position against the gravity of the seat back 4. For this reason, the force required to rotate the seat back 4 from the stowed position to the upright position is greater than the force required to rotate the seat back 4 from the upright position to the stowed position. Therefore, because the spring 15 is provided to bias the seat back 4 to the stowed position, the spring 15 can be smaller than when using a spring 15 that biases the seat back 4 to the upright position.

[0115] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and can be widely modified and implemented. For example, the rotating member 12 and the pressing gear 45 may be integrally formed. The electric motor 13 receives power from the control device 51, but the electric motor 13 does not have to receive power from the control device 51. For example, a power source, a mechanical switch, and the electric motor 13 may be connected, and the power supply to the electric motor 13 may be mechanically switched on and off, so that the seat back 4 is rotated from the stowed position to the upright position using the driving force of the electric motor 13. The locking device 8 is an electric locking device, but it may also be a locking device that switches between a locked state and an unlocked state using a mechanical button.

[0116] Furthermore, for example, when the striker 10 enters the locking device 8 and the cam 8C rotates, the drive shaft of the electric motor 8E rotates, generating electric power from the electric motor 8E. The control device 51 may be configured to detect the electric power generated by the electric motor 8E and determine whether the locking device 8 is in a locked state or an unlocked state based on the electric power generated by the electric motor 8E.

[0117] DESCRIPTION OF SYMBOLS 1: Vehicle seat 2: Automobile (vehicle) 4: Seat back 6: Support device 8: Locking device 9: Seat back frame 10: Striker (connecting member) 11: Base member 12: Rotating member 13: Electric motor (electric actuator) 14: Transmission mechanism 15: Spring 15A: Inner end (one end) 15B: Outer end (other end) 15C: Engaged portion 16: Position determination sensor 26: Stopper pin 31: First plate portion 32: Second plate portion 32B: First connecting portion (connecting portion) 32C: Second connecting portion (connecting portion) 32D: Third connecting portion (connecting portion) 33: Spring support portion 34: Spring engaging portion 35: Pressure receiving pin 44: Arm portion 46: Support portion 51 : Control device F: Floor

Claims

1. A vehicle seat comprising: a support device provided on the floor of a vehicle; a seat back supported by the support device so as to be rotatable between a stowed position and an upright position; and a locking device provided on the seat back and detachably coupled to a coupling member provided on a side wall of the vehicle, for maintaining the seat back in the upright position; wherein the support device comprises: a base member coupled to the floor; a rotating member rotatably supported on the base member and coupled to the seat back; an electric actuator provided on the base member; a transmission mechanism for transmitting the driving force of the electric actuator to the rotating member; and a spring provided between the base member and the rotating member for urging the seat back to the stowed position; and wherein the electric actuator is driven by a supply of electric power to rotate the seat back from the stowed position to the upright position, and is configured to be rotatable when no electric power is supplied.

2. A vehicle seat as described in claim 1, wherein the rotating member has a spring support portion connected to one end of the spring, the base member has a stopper pin, the spring is connected to the spring support portion at one end and has an engaged portion at the other end that can engage with the stopper pin, and the stopper pin is positioned so as to engage with the engaged portion of the spring when the seat back is positioned between the urge start position that is between the stowed position and the upright position and the stowed position.

3. The vehicle seat according to claim 2, wherein the rotating member has a spring engaging portion that can engage with the other end of the spring, and the spring is maintained in a compressed state by being coupled at one end to the spring support portion of the rotating member and engaging at the other end with the spring engaging portion of the rotating member when the seat back is positioned between the storage position and the bias start position, and when the seat back is positioned between the bias start position and the upright position, the spring is coupled at one end to the spring support portion of the rotating member and is compressed by being engaged at the engaged portion of the spring with the stopper pin of the base member.

4. A vehicle seat as described in claim 1, wherein the rotating member has a pressure-receiving pin, and the transmission mechanism has an arm portion that presses the pressure-receiving pin in a direction in which the seat back rotates from the stored position to the upright position.

5. A vehicle seat as described in claim 4, wherein the rotating member has the pressure-receiving pin, and first and second plate portions that support the pressure-receiving pin and face each other with a gap between them, the second plate portion having a connecting portion that extends toward the first plate portion and is connected to the first plate portion, and the pressure-receiving pin, the first plate portion, and the second plate portion cooperate to form a closed cross-sectional structure.

6. A vehicle seat as claimed in claim 1, further comprising: a control device connected to the electric actuator and controlling the drive of the electric actuator; the support device being supported by the base member and having a position determination sensor that detects whether the rotating member is in a first position corresponding to the storage position; the control device being connected to the position determination sensor, and upon receiving a stand-up signal including a stand-up command to rotate the seat back to the stand-up position, obtaining an output from the position determination sensor; determining whether the position of the seat back is at the stand-up position based on the output of the position determination sensor; if it is determined that the position of the seat back is at the stand-up position, driving the electric actuator to rotate the seat back from the stand-up position to the stand-up position; and if it is determined that the position of the seat back is not at the stand-up position, not driving the electric actuator.

7. The vehicle seat according to claim 6, wherein the control device is connected to the locking device and is configured to control the locking device to switch between a locked state in which the locking device and the connecting member are maintained connected to each other, and an unlocked state in which the locking device can be disengaged from the connecting member.

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