Seat for vehicle

Abstract

To reduce the size of a return device for smoothly returning a seat back to a standing position from a tilted position.SOLUTION: A seat 1 includes a seat cushion 2, a seat back 3 rotatably supported on the seat cushion 2, and a return device 6 which is interposed between the seat cushion 2 and the seat back 3 and returns the seat back 3 positioned at a tilted position to a standing position. The return device 6 is interposed between the seat cushion 2 and the seat back 3, and has: a spiral spring 63 for energizing the seat back 3 positioned at the tilted position around a rotation axis of the seat back 3 in a standing direction; and a rotary damper 64 for attenuating rotation speed of the seat back 3 rotated to the standing direction from the tilted position by the energization fore of the spiral spring 63. The rotary damper 64 is arranged so as to be disposed side by side with the spiral spring 63 in the axial direction of the rotation axis 26, and is provided so that the whole rotary damper 64 overlaps the spiral spring 63 when being viewed in the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat to be installed in various types of vehicles. [Background technology]

[0002] Conventionally, there has been known a vehicle seat in which a seat back is rotatably supported on a seat cushion via a spiral spring (see, for example, Patent Document 1). The vehicle seat described in Patent Document 1 has a spiral spring whose one end and the other end are respectively engaged with the seat cushion and the seat back, and is configured so that the seat back, which is locked in a reclined position against the biasing force of the spiral spring, rotates due to the biasing force of the spiral spring and returns to an upright position when the lock is released. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-19444 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the vehicle seat described in Patent Document 1, if a device for adjusting the rotation speed of the seat back toward the standing position is provided, there is a risk that the return device for returning the seat back to the standing position will become large. [Means for solving the problem]

[0005] One aspect of the present invention provides a vehicle seat comprising a seat cushion, a seat back rotatably supported on the seat cushion, and a return device interposed between the seat cushion and the seat back for returning the seat back from a reclined position to an upright position. The return device has a biasing member that biases the seat back from the reclined position in an upright direction around a rotation axis of the seat back, and a damping device that damps the rotation speed of the seat back as it rotates from the reclined position to the upright direction due to the biasing force of the biasing member. The damping device is arranged alongside the biasing member in the axial direction of the rotation axis and is entirely overlapped with the biasing member when viewed from the axial direction. [Effects of the Invention]

[0006] According to the present invention, a seat back that has been locked in a reclined position can be smoothly returned to an upright position without increasing the size of the return device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a side view of a seat according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view of a seat frame that forms the framework of the seat in FIG. 1. [Figure 3] FIG. 10 is a perspective view of a locking device and a returning device provided on a support portion of a cushion side bracket, as viewed from the front. [Figure 4] FIG. 4 is a perspective view of the locking device and the returning device of FIG. 3 as seen from the rear. [Figure 5] 4 is a side view of the return device of FIG. 3 as seen from the side of the seat. [Figure 6] FIG. 4 is a rear view of the return device of FIG. 3 as seen from behind the seat. [Figure 7A] FIG. 10 is a side view of the seat frame locked in a reclined position by the locking device. [Figure 7B] 7B is a side view of the return device in the reclined position of FIG. 7A. [Figure 8A] FIG. 10 is a side view of the seat frame in the process of returning from a reclined position. [Figure 8B]8B is a side view of the return device in the middle of the return process of FIG. 8A. [Figure 9A] FIG. 10 is a side view of the seat frame returned to the upright position by the biasing force of the spiral spring. [Figure 9B] 9B is a side view of the return device in the upright position of FIG. 9A. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 9B. Vehicle seats according to embodiments of the present invention can be used as seats installed in various types of vehicles, such as airplanes, trains, and automobiles. In the following, a seat installed in an automobile, particularly a front seat used in the front seat of an automobile (hereinafter simply referred to as seat 1), will be used as an example of a vehicle seat. In the following, the front-rear direction, left-right direction (width direction), and up-down direction (height direction) will be defined based on the occupant seated in seat 1, and the configuration of each part will be described according to these definitions.

[0009] First, the schematic configuration of a seat 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a side view showing the schematic configuration of the seat 1 according to this embodiment. As shown in FIG. 1, the seat 1 includes a seat cushion 2 that supports the buttocks of an occupant, a seat back 3 that supports the upper body (lower back and back) of the occupant, and a headrest 4 that supports the head of the occupant. The seat cushion 2 is supported by a slide mechanism (not shown) provided on the floor of the vehicle so as to be slidable in the front-rear direction. The seat back 3 is provided at the rear end of the seat cushion 2 and is rotatably supported by the seat cushion 2. The headrest 4 is provided at the upper end of the seat back 3 and is supported by the seat back 3 so as to be movable in the up-down direction. The seat 1 also includes a locking device 5 that fixes the seat back 3 in a predetermined rotational position, and a return device 6 that smoothly returns the seat back 3, locked at the predetermined rotational position, to an upright position.

[0010] Fig. 2 is a side view showing a schematic configuration of a seat frame 10 that forms the framework of the seat 1 of Fig. 1. The seat frame 10 shown in Fig. 2 is in a state where a cushion pad 11 made of a cushioning material such as urethane foam and a cover material 12 made of synthetic leather, fabric, or the like are removed from the seat 1 shown in Fig. 1. As shown in Fig. 2, the seat frame 10 has a seat cushion frame 20 that forms the framework of the seat cushion 2 and a seat back frame 30 that forms the framework of the seat back 3. Unlike the seat cushion 2 and the seat back 3, the headrest 4 does not have a frame that forms the framework, and is configured to be attachable to the seat back frame 30 via a headrest stay 40 that is disposed inside the cover material 12 filled with the cushion pad 11, as shown in Fig. 1.

[0011] The seat cushion frame 20 has a pair of left and right cushion side frames 21, 21 extending in the front-to-rear direction, a cushion pan frame 22 arranged to cover the front end portions of each of the pair of left and right cushion side frames 21, 21, a front pipe 23 extending in the left-to-right direction and connecting the pair of left and right cushion side frames 21, 21 slightly forward of the rear end portion of the cushion pan frame 22, and a rear pipe 24 extending in the left-to-right direction and connecting the rear end portions of the pair of left and right cushion side frames 21, 21.

[0012] The cushion side frames 21 are formed in a generally plate-like shape facing left and right, and are formed to become wider in the vertical direction toward the rear. The outer edges of the cushion side frames 21 are provided with flanges that extend inward or outward to reinforce the frame. The cushion pan frame 22 is also formed in a generally plate-like shape facing up and down, and its tip is positioned slightly forward of the front ends of the pair of left and right cushion side frames 21, 21.

[0013] The seat cushion frame 20 having such a configuration is formed as a roughly rectangular frame in plan view, and inside it, a cushion panel (not shown) that receives loads from above by a seated occupant is arranged so as to span the front pipe 23 and the rear pipe 24.

[0014] The seatback frame 30 has a pair of left and right backside frames 31, 31 extending in the vertical direction, an upper end connecting frame 32 extending in the horizontal direction and connecting the upper ends of the pair of left and right backside frames 31, 31, and a lower connecting frame 33 connecting the lower parts of the pair of left and right backside frames 31, 31.

[0015] The backside frame 31 is formed in a generally plate-like shape facing left and right, and is formed to widen in the front-rear direction as it goes downward. In addition, flanges that extend inward or outward are provided on the outer edges of the backside frame 31 to reinforce the frame.

[0016] The seat back frame 30 having such a configuration is formed into a roughly rectangular frame when viewed from the front, and inside it is a back panel (not shown) that receives the load from the upper body (lower back and back) of the seated occupant, and is arranged so as to span the upper end connecting frame 32 and the lower connecting frame 33.

[0017] The pair of left and right back side frames 31, 31 are rotatably supported at their lower ends by a pair of left and right cushion side brackets 25, 25 fixed to the rear ends of the pair of left and right cushion side frames 21, 21. In other words, the seat back frame 30 is rotatably supported by the seat cushion frame 20 via the pair of left and right cushion side brackets 25, 25 interposed between the seat back frame 30 and the seat cushion frame 20.

[0018] The cushion side bracket 25, like the cushion side frame 21, is formed in a generally plate-like shape facing in the left-right direction and is provided so as to extend obliquely upward and rearward from the rear end of the cushion side frame 21. The cushion side bracket 25 is fixed to the rear end of the cushion side frame 21 on the inner side of the cushion side frame 21 (inside in the left-right direction) with bolts 25a or the like.

[0019] The cushion side bracket 25 configured in this manner is provided at its approximate center with a support portion 27 that rotatably supports the back side frame 31 around a rotation shaft 26 that extends along the left-right axis L1. The angle of the back side frame 31 (seat back 3) shown in FIG. 2 with respect to the horizontal line (hereinafter referred to as the tilt angle θ) is changed via the support portion 27.

[0020] A locking device 5 that locks the seat back 3 in a predetermined position (for example, a reclined position or a driving position) and a return device 6 that smoothly returns the seat back 3 locked in the reclined position to the upright position are arranged side by side in the axial direction of the rotation shaft 26 on the support portion 27. In this embodiment, the locking device 5 and the return device 6 are provided only on the support portion 27 of the right cushion side bracket 25, and the support portion 27 of the left cushion side bracket 25 is provided with the locking device 5 and a biasing member 61, which will be described later.

[0021] In the seat 1, the locking device 5 and the return device 6 are provided on the support portion 27 of the right-side cushion side bracket 25, but the locking device 5 and the return device 6 may also be provided on the support portion 27 of the left-side cushion side bracket 25, or the locking device 5 and the return device 6 may be provided on the support portion 27 of each of the pair of left and right cushion side brackets 25, 25.

[0022] The following description will focus on the locking device 5 and the returning device 6 provided on the support portion 27 of the right cushion side bracket 25. Fig. 3 is a perspective view of the locking device 5 and the returning device 6 provided on the support portion 27 of the right cushion side bracket 25 as seen from the front, and Fig. 4 is a perspective view as seen from the rear.

[0023] 3 and 4, the locking device 5 is disposed on the inner surface (left side) of the cushion side bracket 25, and the returning device 6 is disposed on the outer surface (right side) of the cushion side bracket 25. The returning device 6 located on the outer surface side is covered by a removable cover member (not shown).

[0024] The locking device 5 is provided between the cushion side bracket 25 and the back side frame 31, and locks the seat back 3, which has been tilted against the biasing force of the return device 6, at a predetermined tilted position, or at a driving position tilted slightly rearward from the upright position. In addition to the above, the locking device 5 is configured to be able to lock the seat back 3 in stages from the driving position to the tilted position, and is configured to be able to release the locked state at these positions by a lock release means (not shown).

[0025] In this embodiment, the reclined position is a position where the seat back 3 is reclined at a reclining angle θ of approximately 170° (see FIG. 7A described later), for example, to the extent that the occupant can lie down and relax on the seat cushion 2 and seat back 3. The standing position is a position where the reclining angle θ is approximately 90° (see FIG. 9A described later), for example, to the extent that the seat back 3 is returned to the position where the biasing force of the return device 6 becomes zero. The occupant slightly reclins the seat back 3 from the standing position against the biasing force of the return device 6 (reclining angle θ is approximately 100°) to the extent that the occupant can assume an optimal driving posture, and locks the seat back 3 with the locking device 5 at that position (driving position).

[0026] The locking device 5 has a flat, generally cylindrical outer shape and is attached facing the cushion side bracket 25 so that its centerline extends along the axis L1. A rotation shaft 26 is connected to the locking device 5 along the centerline, and the seat back 3 is locked in a predetermined position (such as a reclined position or a driving position) via the rotation shaft 26. The locking device 5 locks the seat back 3, for example, by stopping the rotation of the seat back 3 transmitted via the rotation shaft 26 using a rotation lock mechanism (not shown) disposed therein, and then unlocks the seat back 3 by releasing the action of the rotation lock mechanism using a lock release means (not shown), thereby allowing the seat back 3 to rotate.

[0027] The locking device 5 can be the same as that used in a general vehicle seat having a reclining mechanism, and therefore a description of the specific configuration thereof will be omitted here.

[0028] Fig. 5 is a side view of the returning device 6 shown in Fig. 3 as seen from the side of the seat 1, and Fig. 6 is a rear view as seen from behind the seat 1. As shown in Figs. 5 and 6, the returning device 6 is configured to include a biasing member 61 that biases the seat back 3 in the upright direction around the rotation axis 26 of the seat back 3, and a damping device 62 that damps the rotation speed of the seat back 3 that rotates in the upright direction due to the biasing force of the biasing member 61.

[0029] The biasing member 61 is arranged on the inner side in the axial direction (toward the locking device 5), and the damping device 62 is arranged on the outer side in the axial direction (to the right of the biasing member 61). That is, in the support part 27, the locking device 5 and the returning device 6 are arranged in the following order from the inner side in the axial direction: locking device 5, biasing member 61, damping device 62, with the damping device 62 being arranged on the outermost side. By arranging the damping device 62 on the outermost side, attachment and removal of the damping device 62 becomes easy, and the maintainability of the damping device 62 can be improved.

[0030] In this embodiment, the biasing member 61 is configured by a spiral spring 63 having a flat, generally cylindrical outer shape. The spiral spring 63 is attached facing the cushion side bracket 25 so that the center line extending along the center of the spiral is aligned with the axis L1. In this way, by using the spiral spring 63 as the biasing member 61, the return device 6 can have a simple configuration.

[0031] The spiral spring 63 is formed by winding a strip-shaped member having a predetermined width in a spiral shape radially outward, and is attached to the outer surface of the cushion side bracket 25 so that the center of the spiral is located on the axis L1. The spiral spring 63 of this embodiment is formed by a spiral spring with a reduced number of turns, and the base end portion constituting the radially inner end portion of the spiral spring 63 is fixed to the outer surface of the cushion side bracket 25 by welding or the like, with the imaginary center of the spiral being located on the axis L1.

[0032] The wound portion 63a, which is wound radially outward from the base end portion multiple times, mainly constitutes the outer shape of the spiral spring 63. The outer diameter W1 of the wound portion 63a, which has a substantially cylindrical shape, is slightly smaller than the outer diameter W0 of the locking device 5, which also has a substantially cylindrical shape (W1≦W0), and the wound portion 63a is arranged so that its entirety overlaps with the locking device 5 when viewed in the axial direction.

[0033] The tip portion that constitutes the radially outer end portion of the spiral spring 63 extends radially outward from the winding portion 63a and constitutes an engaging portion 63b that engages with the seat back frame 30. Specifically, the engaging portion 63b includes a first engaging portion 63c that bends and extends radially outward from the winding portion 63a, and a second engaging portion 63d that bends and extends from the first engaging portion 63c in a direction opposite to the winding direction (biasing direction). The first engaging portion 63c is formed to engage with an engaging portion 34 of an engaging member 34 described later attached to the outer surface of the back side frame 31 and an engaging portion 64c of a rotary damper 64 described later. The second engaging portion 63d extends in a direction opposite to the winding direction along the upper surface of the engaging member 34. When the first engaging portion 63c engages with the engaging member 34, the spiral spring 63 rotates together with the seat back frame 30. When the first engaging portion 63c engages with the engaging portion 64c, the biasing force of the spiral spring 63 acting on the seat back 3 can be attenuated during rotation toward the upright position.

[0034] In the present embodiment, the damping device 62 is constituted by a rotary damper 64 having a substantially cylindrical shape with a flat outer shape. The rotary damper 64 is attached so as to face the cushion side bracket 25 such that the center line extending along the rotation center is along the axis L1. By thus using the rotary damper 64 as the damping device 62, the return device 6 can be made into a simpler configuration.

[0035] The outer diameter W2 of the rotary damper 64 having a substantially cylindrical shape is smaller than the outer diameter Wl of the winding portion 63a of the spiral spring 63 having a substantially cylindrical shape (W2 < W1), and the rotary damper 64 is provided so that all of it overlaps with the winding portion 63a when viewed from the axial direction. By using the rotary damper 64 as the damping device 62 and configuring the rotary damper 64 in this way, the return device 6 can be miniaturized with a simpler configuration.

[0036] Furthermore, the left-right length (axial length) of rotary damper 64 is longer than the left-right length of winding portion 63a and locking device 5 alone, but shorter than the left-right length of both winding portion 63a and locking device 5. By configuring locking device 5, spiral spring 63, and rotary damper 64 in this way, the reclining mechanism including locking device 5 and return device 6 can be made smaller.

[0037] The rotary damper 64 has a fixed portion 64a fixed to the cushion side bracket 25 and a rotating portion 64b rotatably supported by the fixed portion 64a. The fixed portion 64a is filled with oil and generates a predetermined torque in the rotating portion 64b. The rotating portion 64b is provided with an engaging portion 64c extending radially outward and engageable with the spiral spring 63. Specifically, the engaging portion 64c has a first engaging portion 64d extending radially outward from the rotating portion 64b and a second engaging portion (extending portion) 64e extending axially inward from the tip of the first engaging portion 64d toward the first engaging portion 63c of the spiral spring 63. The first engaging portion 64d is formed to be engageable with the engaging member 34, and the second engaging portion 64e is formed to be engageable with the first engaging portion 63c of the spiral spring 63. When the first engagement portion 64d engages with the engagement member 34, the rotating portion 64b rotates together with the spiral spring 63, and when the second engagement portion 64e engages with the first engagement portion 63c of the spiral spring 63, the spring force of the spiral spring 63 acting on the seat back 3 during the rotation of the seat back 3 can be attenuated.

[0038] An engaging member 34 is attached to the outer surface of the backside frame 31. The engaging member 34 is formed to be able to engage with the engaging portion 63b of the spiral spring 63 and the engaging portion 64c of the rotary damper 64. The engaging member 34 is configured to have a fixing portion 34a fixed to the outer surface of the backside frame 31 by welding or the like, and an extending portion 34b extending axially outward from the fixing portion 34a. The extending portion 34b is formed in a rectangular plate shape and has a recessed portion 34c provided on the rear surface side and a restricting portion 34d provided at the tip. The recessed portion 34c is formed in a concave shape that is able to engage with the first engaging portion 63c of the spiral spring 63 and the first engaging portion 64d of the rotary damper 64. The restricting portion 34d protrudes in the opposite direction to the biasing direction of the spiral spring 63, and restricts the axial outward movement of the first engaging portion 63c of the spiral spring 63 and the first engaging portion 64d of the rotary damper 64 located in the recess 34c.

[0039] The support portion 27 of the left cushion side bracket 25 is provided with the same configuration as the locking device 5 and spiral spring 63 described above, and the outer surface of the left back side frame 31 is provided with the same configuration as the engaging member 34 described above. In particular, the same parts are used for the engaging member 34.

[0040] Next, the pivoting operation of the seat 1 having the locking device 5 and the returning device 6 configured as described above will be described with reference to Figures 7A to 9B. Figure 7A is a side view of the seat frame 10 locked in a reclined position by the locking device 5, and Figure 7B is a side view of the returning device 6 in the reclined position of Figure 7A. Figure 8A is a side view of the seat frame 10 in the middle of returning from the reclined position, and Figure 8B is a side view of the returning device 6 in the middle of returning of Figure 8A. Figure 9A is a side view of the seat frame 10 returned to the upright position by the biasing force of the spiral spring 63, and Figure 9B is a side view of the returning device 6 in the upright position of Figure 9A.

[0041] 7A, the seatback frame 30 is locked to the seat cushion frame 20 by the locking device 5 so that the seat cushion 2 and the seatback 3 are substantially flat. In this state, as shown in FIG. 7B, the engaging portion 63b of the spiral spring 63 and the engaging portion 64c provided on the rotating portion 64b of the rotary damper 64 are pressed by the engaging member 34 attached to the back side frame 31, and are rotated together with the seatback 3 to the reclined position.

[0042] When the locking by the locking device 5 is released from this state using a lock releasing means (not shown), the urging force of the spiral spring 63 causes the engaging portion 63b of the spiral spring 63 to urge the engaging member 34 attached to the back side frame 31 in the upright direction. Similarly, the spiral spring 63 also urges the rotating portion 64b of the rotary damper 64 in the upright direction via the second engaging portion 64e of the rotary damper 64 that engages with the first engaging portion 63c.

[0043] When the seat back 3 is biased by the spiral spring 63 and rotates to the position shown in Fig. 8A, for example, and the rotating portion 64b of the rotary damper 64 rotates to the position shown in Fig. 8B, the fixed portion 64a of the rotary damper 64 generates a predetermined torque on the rotating portion 64b. When the predetermined torque is applied to the rotating portion 64b by the fixed portion 64a, a damping force that attenuates the rotation speed of the seat back 3 acts against the biasing force of the spiral spring 63 via the first engaging portion 63c that engages with the second engaging portion 64e. Because the predetermined torque by the fixed portion 64a gradually increases, the rotation speed of the seat back 3 gradually slows as it approaches the upright position.

[0044] In the upright position shown in Figure 9A, the biasing force of the spiral spring 63 becomes 0, but since the damping force of the rotary damper 64 acts during the rotation of the seat back 3, the seat back 3 stops in the upright position without tilting forward beyond the upright position due to inertia force.

[0045] In this way, by using the returning device 6 according to this embodiment, the rotation speed of the seat back 3 is decelerated during rotation, so that the seat back 3 can be smoothly positioned in the upright position. Furthermore, by configuring the damping device 62, which is arranged alongside the biasing member 61 in the axial direction, so that the entire device overlaps with the biasing member 61 when viewed from the axial direction, it is possible to prevent the returning device 6 from becoming large. In particular, by using the spiral spring 63 and rotary damper 64 that can be configured as described above, it is possible to prevent the returning device 6 from becoming large with a simpler configuration.

[0046] According to this embodiment, the following effects can be achieved. (1) The seat 1 according to this embodiment includes a seat cushion 2, a seat back 3 rotatably supported by the seat cushion 2, and a return device 6 interposed between the seat cushion 2 and the seat back 3 to return the seat back 3 from a reclined position to an upright position. The return device 6 includes a biasing member 61 that biases the seat back 3 from a reclined position in an upright direction around a rotation axis 26 of the seat back 3, and a damping device 62 that damps the rotation speed of the seat back 3 that rotates from the reclined position toward the upright direction due to the biasing force of the biasing member 61. The damping device 62 is arranged alongside the biasing member 61 in the axial direction of the rotation axis 26, and is arranged so that its entirety overlaps with the biasing member 61 when viewed from the axial direction.

[0047] This configuration allows the return device 6 including the damping device 62 to be arranged without increasing the size, so that the rotation speed of the seat back 3 locked in the reclined position can be slowed down as it moves toward the upright position, allowing for smooth return without increasing the size of the seat 1.

[0048] (2) In the seat 1 described in (1), the damping device 62 is disposed further outward in the axial direction of the pivot shaft 26 than the biasing member 61. This configuration makes it easy to attach and detach the damping device 62, facilitating maintenance of the return device 6. For example, it makes it easy to replace the damping device 62.

[0049] (3) In the seat 1 described in (1) or (2), the biasing member 61 is configured by a spiral spring 63 wound radially outward, and the damping device 62 is configured by a rotary damper 64, and the spiral spring 63 and the rotary damper 64 are arranged coaxially. This allows the return device 6 to have a simpler configuration.

[0050] (4) In the seat 1 described in (3), the seat back 3 has an engagement member 34 configured to be able to engage with an engagement portion 63b provided at the radially outer end of the spiral spring 63 and an engagement portion 64c provided at the radially outer end of the rotary damper 64. The engagement member 34 is provided axially outward of the engagement portions 63b, 64c of the spiral spring 63 and the rotary damper 64, respectively, and has a restriction portion 34d that protrudes in the opposite direction to the biasing direction and restricts axial movement of the engagement portions 63b, 64c of the spiral spring 63 and the rotary damper 64, respectively. This configuration makes it possible to prevent axial movement of the engagement portion 64c of the rotary damper 64, etc.

[0051] (5) In the seat 1 described in (4), the engagement portion 64c of the rotary damper 64 extends axially inward and has a second engagement portion 64e (extension portion) configured to be able to engage with the first engagement portion 63c of the spiral spring 63. The first engagement portion 63c of the spiral spring 63 is configured to be able to engage with the engagement member 34 of the seat back 3 and the second engagement portion 64e of the rotary damper 64.

[0052] This configuration allows the spiral spring 63 to rotate together with the seatback frame 30, and when the seatback 3 is unlocked and returns to the upright position, the biasing force of the spiral spring 63 can be attenuated midway through the rotation of the seatback 3. This slows down the rotation speed of the seatback 3 as it approaches the upright position. As a result, the return of the seatback 3 from the reclined position to the upright position can be made smoother.

[0053] The above description is merely an example, and the present invention is not limited to the above-described embodiment as long as the features of the present invention are not impaired. For example, although the above embodiment has been described using a front seat of an automobile as the vehicle seat, it may also be used in a rear seat of an automobile. When used in a rear seat, the biasing direction of the spiral spring may be reversed. For example, it may also be used to return a seat from a forward tilted state.

[0054] Furthermore, in the above embodiment, the returning device 6 is configured to be disposed on the outer surface side of the cushion side bracket 25, but it may also be configured to be disposed on the axial inside of the cushion side bracket 25, for example, on the inner surface side of the back side frame 31. If the returning device is compact, it can be expected to be configured to be disposed on the inner surface side of the back side frame 31, and disposing it on the inner surface side of the back side frame 31 can be expected to make the seat more compact.

[0055] Furthermore, in the above embodiment, the second engagement portion 64e of the rotary damper 64 is engaged with the first engagement portion 63c of the spiral spring 63 to attenuate the spring force of the spiral spring 63 acting on the seat back 3 during the rotation of the seat back 3. However, for example, the second engagement portion 64e of the rotary damper 64 may be engaged with the opposite side of the recess 34c provided in the engagement member 34 of the back side frame 31 to attenuate the rotation speed of the seat back 3.

[0056] In addition, in the above embodiment, the spiral spring 63 is used as the biasing member 61, but a configuration using a biasing means other than the spiral spring 63 is also possible. Similarly, the rotary damper 64 is used as the damping device 62, but a configuration using a damping means other than the rotary damper 64 is also possible. [Explanation of symbols]

[0057] 1 seat (vehicle seat), 2 seat cushion, 3 seat back, 6 return device, 26 pivot shaft, 61 biasing member, 62 damping device, 63 spiral spring, 64 rotary damper

Claims

1. Seat cushion and a seat back rotatably supported by the seat cushion; a return device interposed between the seat cushion and the seat back for returning the seat back from a reclined position to an upright position, The return device is a biasing member that biases the seat back, which is positioned in a reclined position, in an upright direction about a rotation axis of the seat back; a damping device that damps the rotation speed of the seat back that rotates from the reclined position toward the upright direction due to the biasing force of the biasing member, The damping device is arranged alongside the biasing member in the axial direction of the pivot shaft, and is arranged so that its entirety overlaps with the biasing member when viewed from the axial direction.

2. The vehicle seat according to claim 1, The vehicle seat, wherein the damping device is disposed axially outward of the pivot shaft relative to the biasing member.

3. The vehicle seat according to claim 1 or 2, the biasing member is configured by a spiral spring wound radially outward, and the damping device is configured by a rotary damper, A vehicle seat, wherein the biasing member and the damping device are coaxially arranged.

4. The vehicle seat according to claim 3, the seat back has an engaging member configured to be engageable with an engaging portion provided at a radially outer end of the biasing member and an engaging portion provided at a radially outer end of the damping device, The vehicle seat is characterized in that the engaging member is provided axially outward of the engaging portions of the biasing member and the damping device, and has a regulating portion that protrudes in the opposite direction to the biasing direction and regulates the axial movement of the engaging portions of the biasing member and the damping device.

5. The vehicle seat according to claim 4, the engaging portion of the damping device has an extending portion that extends axially inward and is configured to be engageable with the engaging portion of the biasing member, The vehicle seat according to claim 1, wherein the engaging portion of the biasing member is configured to be engageable with the engaging member of the seat back and the extension portion of the damping device.

Images