Vehicle seat and method for manufacturing a vehicle seat

Abstract

To arrange an occupant detection device, in a vehicle seat having a sheet-like member.SOLUTION: A vehicle seat 300, 400, 500 has a seat cushion 2 and a seat back 3, where the seat cushion 2 includes: a seat cushion frame 31; a pad 307 supported by the seat cushion frame 31; and a skin material 308 placed on a pad 307. The seat cushion frame 31 includes left and right side members 32 extending forward and backward, a front member 33 which extends to the left and right and is connected to the front parts of the left and right side members 32 and a rear member 34 which extends to the left and right and is connected to the rear parts of the left and right side members 32. A sheet-like member 301 extends forward and backward, has a surface which faces up and down and is flexible and bridged between the front member 33 and the rear member 34. At least part of the pad 307 is supported from below on the sheet-like member 301, and an occupant detection sensor 309 is provided on the pad 307.SELECTED DRAWING: Figure 21

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a seat cushion for a vehicle. The seat cushion includes a frame-shaped seat cushion frame having left and right side members, a front member, and a rear member, a sheet-like member spanned between the front member and the rear member, a pad supported from below by the seat cushion frame and the sheet-like member, and a skin material covering the pad. The sheet-like member is formed of a flexible woven fabric such as cloth.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle seat, in order to determine whether an occupant is seated or not, an occupant detection sensor is often provided in the seat cushion. Therefore, there is a demand for providing an occupant detection sensor also in a seat cushion having a sheet-like member.

[0005] In view of the above background, an object of the present invention is to arrange an occupant detection device in a vehicle seat having a sheet-like member.

Means for Solving the Problems

[0006] In order to solve the above problems, one aspect of the present invention is a vehicle seat (300, 400, 500) having a seat cushion (2) and a seat back (3), wherein the seat cushion (2) includes a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a skin material (308) covering the pad (307). The seat cushion frame (31) has left and right side members (32) extending in the front-rear direction, a front member (33) extending in the left-right direction and coupled to the front portions of the left and right side members (32), and a rear member (34) extending in the left-right direction and coupled to the rear portions of the left and right side members (32). A sheet-like member (301) that extends in the front-rear direction and has a surface facing up and down and is flexible is spanned between the front member (33) and the rear member (34). At least a part of the pad (307) is supported from below by the sheet-like member (301), and an occupant detection sensor (309) is provided in the pad (307).

[0007] According to this aspect, in a vehicle seat having a sheet-like member (301), an occupant detection device can be arranged.

[0008] In the above aspect, the occupant detection sensor (309) is provided on the upper surface of the pad (307), and a harness (310) connected to the occupant detection sensor (309) passes through a first hole (307A) penetrating the pad (307) vertically and a second hole (312) penetrating the sheet-like member (301) vertically, and extends downward from the occupant detection sensor (309) below the sheet-like member (301).

[0009] According to this aspect, in a seat cushion (2) having a sheet-like member (301), a harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0010] In the above aspect, a grommet (314) may be attached to the edge of the second hole (312).

[0011] According to this aspect, damage to the edge of the second hole (312) due to contact with the harness (310) can be prevented.

[0012] In the above aspect, a support member (522) having flexibility and supporting from below the sheet-like member (301) is provided between the front member (33) and the rear member (34), and the harness (310) passes through a third hole (313) provided in the support member (522) and extends downward from the occupant detection sensor (309) below the support member (522).

[0013] According to this aspect, in the seat cushion (2) having the support member (522) that supports the sheet-like member (301), the harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0014] In the above aspect, the occupant detection sensor (309) is provided on the upper surface of the pad (307), and the harness (310) connected to the occupant detection sensor (309) passes through a first hole (311) that vertically penetrates the pad (307), and passes through the gap between the sheet-like member (301) and the side member (32), and extends downward from the occupant detection sensor (32) below the sheet-like member (301).

[0015] According to this aspect, in the seat cushion (2) having the sheet-like member (301), the harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0016] In the above aspect, a resin cover (418) is attached to the side member (33), and the harness (310) passes through the gap between the sheet-like member (301) and the cover (418) and extends downward from the occupant detection sensor (309) below the sheet-like member (301).

[0017] According to this aspect, contact between the harness (310) and the side member (33) can be avoided, and wear of the harness (310) can be suppressed.

[0018] In the above aspect, the seat back (3) rotates between a use position extending upward from the rear part of the seat cushion (2) and a storage position overlapping the upper side of the seat cushion (2) by rotating forward from the use position. At least one of the seat cushion (2) and the seat back (3) is provided with a regulating portion (315) for regulating the position of the seat back (3) in the storage position with respect to the seat cushion (2). When the seat back (3) is in the storage position, the load applied by the seat back (3) to the occupant detection sensor (309) is suppressed to a predetermined value or less by the regulating portion (315).

[0019] According to this aspect, when the seat back (3) is in the storage position, it is possible to prevent the occupant detection sensor (309) from being pushed by the seat back (3) and misdetecting.

[0020] In the above aspect, the seat back (3) has left and right side support portions (316) protruding forward from the left and right side portions in the use position, and the regulating portion (315) includes the side support portions (316).

[0021] According to this aspect, the load applied from the seat back (3) to the occupant detection sensor (309) can be suppressed by using the side support portions (316).

[0022] In the above aspect, a headrest (317) is provided on the seat back (3), and the regulating portion (315) includes the headrest (317).

[0023] According to this aspect, the load applied from the seat back (3) to the occupant detection sensor (309) can be suppressed by using the headrest (317).

[0024] In the above aspect, the seat back (3) is rotatably supported by a base (7) provided on the floor (4), the seat cushion (2) is rotatably supported by the seat back (3), the base (7) has left and right base side members (11) extending in the front - rear direction and a base cross member (13) extending in the left - right direction and coupled to the left and right base side members (11), and the harness (310) is fixed to the base cross member (213).

[0025] According to this aspect, the position of the harness can be stabilized below the seat cushion (2).

[0026] Another aspect of the present invention is a method for manufacturing a vehicle seat (300, 400, 500) having a seat cushion (2) and a seat back (3), wherein the seat cushion (2) has a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a cover (418) covering the pad (307), the seat cushion frame (31) has left and right side members (32) extending in the front - rear direction, a front member extending in the left - right direction and coupled to the front portions of the left and right side members (32), and a rear member (34) extending in the left - right direction and coupled to the rear portions of the left and right side members (32), and a step of bridging a sheet - like member (301) having a surface facing up and down and having flexibility and extending in the front - rear direction between the front member (33) and the rear member (34), and a step of supporting the pad (307) provided with an occupant detection sensor (309) on the seat cushion frame (31) and the sheet - like member (301).

[0027] According to this aspect, a vehicle seat (300, 400, 500) having a sheet - like member (301) and an occupant detection sensor (309) can be manufactured by a simple procedure.

Advantages of the Invention

[0028] One aspect of the present invention is a vehicle seat (300, 400, 500) having a seat cushion (2) and a seat back (3), wherein the seat cushion (2) includes a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a skin material (308) covering the pad (307). The seat cushion frame (31) has left and right side members (32) extending in the front-rear direction, a front member (33) extending in the left-right direction and coupled to the front portions of the left and right side members (32), and a rear member (34) extending in the left-right direction and coupled to the rear portions of the left and right side members (32). A sheet-like member (301) that extends in the front-rear direction and has a surface facing up and down and is flexible is spanned between the front member (33) and the rear member (34). At least a part of the pad (307) is supported from below by the sheet-like member (301), and an occupant detection sensor (309) is provided in the pad (307).

[0029] According to this aspect, in a vehicle seat having a sheet-like member (301), an occupant detection device can be arranged.

[0030] In the above aspect, the occupant detection sensor (309) is provided on the upper surface of the pad (307), and a harness (310) connected to the occupant detection sensor (309) passes through a first hole (307A) that vertically penetrates the pad (307) and a second hole (312) that vertically penetrates the sheet-like member (301), and extends downward from the occupant detection sensor (309) below the sheet-like member (301).

[0031] According to this aspect, in a seat cushion (2) having a sheet-like member (301), a harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0032] In the above aspect, a grommet (314) may be attached to the edge of the second hole (312).

[0033] According to this aspect, damage to the edge of the second hole (312) due to contact with the harness (310) can be prevented.

[0034] In the above aspect, a support member (522) having flexibility and supporting from below the sheet-like member (301) is provided between the front member (33) and the rear member (34), and the harness (310) passes through a third hole (313) provided in the support member (522) and extends downward from the support member (522) from the occupant detection sensor (309).

[0035] According to this aspect, in the seat cushion (2) having the support member (522) that supports the sheet-like member (301), the harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0036] In the above aspect, the occupant detection sensor (309) is provided on the upper surface of the pad (307), and the harness (310) connected to the occupant detection sensor (309) passes through a first hole (311) that vertically penetrates the pad (307), and passes through the gap between the sheet-like member (301) and the side member (32), and extends downward from the occupant detection sensor (32) below the sheet-like member (301).

[0037] According to this aspect, in the seat cushion (2) having the sheet-like member (301), the harness (310) extending from the occupant detection sensor (309) can extend below the sheet-like member (301).

[0038] In the above aspect, a resin cover (418) is attached to the side member (33), and the harness (310) passes through the gap between the sheet-like member (301) and the cover (418), and extends downward from the occupant detection sensor (309) below the sheet-like member (301).

[0039] According to this aspect, contact between the harness (310) and the side member (33) can be avoided, and wear of the harness (310) can be suppressed.

[0040] In the above aspect, the seat back (3) rotates between a use position extending upward from the rear part of the seat cushion (2) and a storage position overlapping the upper side of the seat cushion (2) by rotating forward from the use position, and at least one of the seat cushion (2) and the seat back (3) is provided with a regulating portion (315) for regulating the position of the seat back (3) in the storage position with respect to the seat cushion (2). When the seat back (3) is in the storage position by the regulating portion (315), the load applied by the seat back (3) to the occupant detection sensor (309) is suppressed to a predetermined value or less.

[0041] According to this aspect, when the seat back (3) is in the storage position, it is possible to prevent the occupant detection sensor (309) from being pushed by the seat back (3) and misdetecting.

[0042] In the above aspect, the seat back (3) has left and right side support portions (316) protruding forward from the left and right side portions in the use position, and the regulating portion (315) includes the side support portions (316).

[0043] According to this aspect, the load applied from the seat back (3) to the occupant detection sensor (309) can be suppressed by using the side support portions (316).

[0044] In the above aspect, a headrest (317) is provided on the seat back (3), and the regulating portion (315) includes the headrest (317).

[0045] According to this aspect, the load applied from the seat back (3) to the occupant detection sensor (309) can be suppressed by using the headrest (317).

[0046] In the above aspect, the seat back (3) is rotatably supported by a base (7) provided on the floor (4), the seat cushion (2) is rotatably supported by the seat back (3), the base (7) has left and right base side members (11) extending in the front-rear direction and a base cross member (13) extending in the left-right direction and coupled to the left and right base side members (11), and the harness (310) is fixed to the base cross member (213).

[0047] According to this aspect, the position of the harness can be stabilized below the seat cushion (2).

[0048] Another aspect of the present invention is a method for manufacturing a vehicle seat (300, 400, 500) having a seat cushion (2) and a seat back (3), the seat cushion (2) having a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a cover (418) covering the pad (307), the seat cushion frame (31) having left and right side members (32) extending in the front-rear direction, a front member extending in the left-right direction and coupled to the front portions of the left and right side members (32), and a rear member (34) extending in the left-right direction and coupled to the rear portions of the left and right side members (32), and a step of bridging a sheet-like member (301) having a surface facing up and down and extending in the front-rear direction and having flexibility between the front member (33) and the rear member (34), and a step of supporting the pad (307) provided with an occupant detection sensor (309) on the seat cushion frame (31) and the sheet-like member (301).

[0049] According to this aspect, a vehicle seat (300, 400, 500) having a sheet-like member (301) and an occupant detection sensor (309) can be manufactured by a simple procedure. BRIEF DESCRIPTION OF THE DRAWINGS

[0050]

Figure 1

Figure 2

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Embodiments for Carrying Out the Invention

[0051] Hereinafter, with reference to the drawings, an embodiment in which the vehicle seats 1 and 200 according to the present invention are applied to the rear seats (including the second and third rows) of an automobile will be described. As will be described later, the vehicle seats 1 and 200 change in form between a use form (seating form) and a storage form. Unless otherwise specified, the shape and orientation of each component of the vehicle seats 1 and 200 will be described based on the use form. Further, when it is described that each member is joined, unless otherwise specified, the joining mode shall include welding and fastening.

[0052] As shown in FIGS. 1 and 10, the seat 1 has a seat cushion 2 and a seat back 3. The seat back 3 is rotatably supported by the floor 4, and the seat cushion 2 is rotatably supported by the seat back 3. A locking device 5 for selectively restricting the rotation of the seat back 3 with respect to the floor 4 is provided between the seat back 3 and the floor 4. In the use form of the seat 1, the seat back 3 stands up with respect to the floor 4, and the seat cushion 2 is separated upward from the floor 4. From the use form of the seat 1, when the seat back 3 rotates forward, the seat 1 becomes the storage form. When the seat 1 changes from the use form to the storage form, the seat cushion 2 moves downward and approaches the floor 4. In the storage form of the seat 1, the seat back 3 extends substantially horizontally and overlaps above the seat cushion 2.

[0053] As shown in FIGS. 1 and 2, a base 7 is provided on the floor 4. The base 7 extends back and forth on the upper surface of the floor 4, and includes left and right base side members 11 coupled to the floor 4, left and right base pillars 12 extending upward from the rear ends of the left and right base side members 11, and a base cross member 13 extending left and right and coupled to the left and right base side members 11. Each of the base side member 11, the base pillar 12, and the base cross member 13 is formed of sheet metal.

[0054] As shown in FIGS. 1 to 3, the left and right base side members 11 have a bottom wall portion 11A whose surface faces up and down and is coupled to the floor 4, and a vertical wall portion 11B extending upward from a side edge of the bottom wall portion 11A. The base pillar 12 and the base side member 11 may be formed of a common sheet metal or may be formed of sheet metals independent of each other. In the present embodiment, the right base pillar 12 is integrally formed with the base side member 11. The left base pillar 12 is formed of a sheet metal independent of the base side member 11 and is coupled to the base side member 11. The base pillar 12 has a plate-shaped pillar main body portion 12A whose surface faces left and right, and pillar edge wall portions 12B extending left and right outward from the front edge and the rear edge of the pillar main body portion 12A.

[0055] The base cross member 13 has a lower channel member 13A with a cross-sectional groove shape that opens upward and an upper channel member 13B with a cross-sectional groove shape that opens downward. The length of the upper channel member 13B in the left-right direction is shorter than the length of the lower channel member 13A in the left-right direction. The upper channel member 13B and the lower channel member 13A cooperate to form a closed cross-sectional structure. The upper channel member 13B is preferably fitted inside the lower channel member 13A. The left and right ends of the lower channel member 13A are coupled to the vertical wall portions 11B of the corresponding base side members 11. The left end portion of the upper channel member 13B is coupled to the left vertical wall portion 11B. The right end portion of the upper channel member 13B is disposed to the left of the center in the left-right direction of the lower channel member 13A. Concavo-convex structures such as beads may be provided at the bottoms of the lower channel member 13A and the upper channel member 13B to enhance rigidity.

[0056] As shown in FIGS. 1 and 4, the seat back 3 has a seat back frame 16. A pad (not shown) is supported by the seat back frame 16, and the pad and the seat back frame 16 are covered by a skin material (not shown). The seat back frame 16 has left and right back side members 17, an upper member 18, a lower member 19, a first cross member 21, a second cross member 22, a third cross member 23, and a plate member 24. The left and right back side members 17 extend vertically with a space therebetween in the left-right direction. The upper member 18 extends in the left-right direction and is coupled to the upper ends of the left and right back side members 17. The lower member 19 extends in the left-right direction below the upper member 18 and is coupled to the lower portions of the left and right back side members 17. The first to third cross members 21 to 23 extend in the left-right direction between the upper member 18 and the lower member 19 and are coupled to the middle portions of the left and right back side members 17.

[0057] The left and right back side members 17 each have an upper side member 17A and a lower side member 17B coupled to the upper side member 17A. The left and right upper side members 17A and the upper member 18 are formed by bending a continuous pipe material. The left and right lower side members 17B are formed of sheet metal and have a main body portion 17C whose surface faces left and right, and edge wall portions 17D bent inward to the left and right from the edge of the main body portion 17C.

[0058] The upper member 18 is provided with left and right headrest support portions 26. The left and right headrest support portions 26 are coupled to the front surface of the central portion in the left - right direction of the upper member 18 with a space therebetween. The left and right headrest support portions 26 are formed in a cylindrical shape and extend downward from the upper member 18.

[0059] As shown in FIGS. 4 to 7, the lower member 19 has a rear channel member 19A with a cross - sectional groove shape opening forward and a front channel member 19B with a cross - sectional groove shape opening forward. The length of the front channel member 19B in the left - right direction is shorter than the length of the rear channel member 19A in the left - right direction. The rear channel member 19A and the front channel member 19B cooperate to form a closed cross - section structure. The front channel member 19B may be fitted inside the rear channel member 19A. The left and right ends of the rear channel member 19A are disposed inside the edge wall portions 17D of the corresponding lower side members 17B on the left and right and are welded to the edge wall portions 17D. The end portions of the edge wall portions 17D of the lower side members 17B may be welded to the rear surface of the rear channel member 19A. The end portions of the rear channel member 19A have extension portions 19C in order to expand the contact area with the edge wall portions 17D of the lower side members 17B. The extension portions 19C may be provided at the tips of the side wall portions forming the groove shape of the rear channel member 19A.

[0060] The left end of the front channel member 19B is coupled to the main body 17C of the lower part of the left side member 17B. The right end of the front channel member 19B is disposed to the left of the center in the left-right direction of the rear channel member 19A. On the bottoms of the rear channel member 19A and the front channel member 19B, it is preferable to provide convex portions 19D such as beads to enhance rigidity. The convex portion 19D bulges toward the front channel member 19B side and preferably abuts against the front channel member 19B. Further, the convex portion 19D preferably extends left and right along the rear channel member 19A.

[0061] As shown in FIGS. 1 and 4, the first cross member 21 and the second cross member 22 are formed of bar members having a circular cross section. The first cross member 21 extends left and right below the upper member 18 and above the lower member 19. The left and right end portions 21A of the first cross member 21 are bent upward with respect to the central portion and welded to the corresponding upper side member 17A. The second cross member 22 extends left and right below the first cross member 21 and above the lower member 19. The left and right end portions of the second cross member 22 are bent upward with respect to the central portion and welded to the corresponding upper side member 17A.

[0062] The third cross member 23 extends left and right below the second cross member 22 and above the lower member 19 and is welded to the lower parts of the left and right side members 17B. The third cross member 23 is preferably formed of a plurality of sheet metal members. The third cross member 23 has a main body portion 23A whose surface faces front and rear, and a bent portion 23B that extends forward and upward from the lower edge of the main body portion 23A and then further bends and extends downward. An anchor 23C that protrudes forward is provided at the lower edge of the third cross member 23. The anchor 23C is used to lock the hook of the child seat.

[0063] The plate member 24 has a surface facing front and back, and is welded to the left and right back side members 17, upper member 18, lower member 19, and the third cross member 23. The upper edge of the plate member 24 is located above the upper member 18 and extends left and right. The lower edge of the plate member 24 is located below the lower member 19 and extends left and right. The left and right side edges of the plate member 24 are located left and right outward of the left and right back side members 17 and extend vertically. Each edge of the plate member 24 is provided with a curved portion 24A that is curved in an arc shape. The curved portion 24A has a semi-circular cross-section that bulges forward and extends along each edge. It is preferable that a plurality of uneven structures such as beads are provided on each curved portion 24A. Each uneven structure preferably extends in a direction orthogonal to the extending direction of the curved portion 24A. Each curved portion 24A and each uneven structure improve the rigidity of the plate-like portion.

[0064] The plate member 24 has a flat portion 24B with a surface facing front and back, and a plurality of raised portions 24C that protrude from the flat portion 24B. The raised portions 24C preferably protrude forward or backward with respect to the flat portion 24B. Each raised portion 24C is formed by pushing out the plate-like portion forward or backward. The raised portions 24C improve the rigidity of the plate member 24.

[0065] As shown in FIGS. 4 and 6, at least one through hole 19E that penetrates front and back is formed in the rear channel member 19A and the front channel member 19B of the lower member 19. The through hole 19E of the front channel member 19B is arranged at a position that overlaps the through hole 19E of the rear channel member 19A in the front and back directions. The plate member 24 is provided with a mark for aligning its position with the lower member 19. The mark may be a hole, a convex portion, a concave portion, a pattern, or the like. When the plate member 24 is arranged at an appropriate position with respect to the lower member 19, the mark is exposed forward through the through hole 19E.

[0066] In other embodiments, the left and right backside members 17, the upper member 18, and the lower member 19 may be integrally formed with the plate member 24. For example, a three-dimensional shape may be formed by press-molding the plate member 24, and this three-dimensional shape may constitute the backside members 17, the upper member 18, and the lower member 19.

[0067] The outer shape of the electronic control device 42 is preferably formed in a shape that does not give a sense of discomfort to the back of the seated person. For example, the left part of the outer shape of the electronic control device 42 provided on the right side of the seat back 3 may be formed by a surface that slopes backward toward the left. Also, the left part of the outer shape of the electronic control device 42 is preferably formed by a smooth curved surface. With this configuration, the electronic control device 42 provided on the seat back 3 can reduce the sense of discomfort given to the back of the seated person.

[0068] As shown in FIGS. 1 and 4, the lower portions 17B of the left and right side members are rotatably supported via a locking device 5 on the corresponding base pillars 12 on the left and right. The rotation axes of the lower portions 17B of the left and right side members extend left and right and are coaxially arranged with each other. The locking device 5 is arranged coaxially with the rotation axis of the lower portion 17B of the side member.

[0069] As shown in FIG. 8, the lock device 5 has an operation shaft 5A that extends along the rotation axis of the backside member 17, penetrates the backside member 17, and protrudes inwardly to the left and right of the backside member 17. When the operation shaft 5A rotates, it allows or restricts the rotation of the backside member 17 with respect to the floor 4. A known reclining mechanism can be applied to the lock device 5. The lock device 5 includes, for example, a first portion coupled to the base pillar 12, a second portion coupled to the lower side member 17B and rotatably supported by the first portion, a lock claw provided on the second portion and movable between a coupling position coupled to the first portion and a release position away from the first portion, a spring that biases the lock claw to the coupling position, an operation shaft 5A disposed coaxially with the rotation axis of the second member with respect to the first member and rotatable with respect to the second member, and a cam coupled to the operation shaft 5A and that moves the lock claw against the biasing force of the spring to the release position by rotating. When no external operating force is applied to the operation shaft 5A, the operation shaft 5A returns to the initial position by the biasing force of the spring. When the operation shaft 5A rotates with respect to the backside member 17, the seat back 3 becomes rotatable with respect to the floor 4. An operation lever 5B extending radially is provided at each end of each operation shaft 5A.

[0070] As shown in FIG. 1, the seat cushion 2 has a seat cushion frame 31. A pad is supported on the seat cushion frame 31, and the pad and the seat cushion frame 31 are covered with a skin material. The seat cushion frame 31 includes left and right cushion side members 32, a front member 33, a rear member 34, and a center plate 35. The left and right cushion side members 32 extend longitudinally with a space therebetween on the left and right. The front member 33 extends horizontally and is coupled to the front ends of the left and right cushion side members 32. The rear member 34 extends horizontally and is coupled to the rear ends of the left and right backside members 17. The center plate 35 extends longitudinally and is coupled to the front member 33 and the rear member 34.

[0071] At the rear ends of the left and right cushion side members 32, left and right rear links 37 extending rearward and upward are coupled. The left and right rear links 37 move integrally with the left and right cushion side members 32. The rear ends of the left and right rear links 37 are rotatably supported about an axis extending horizontally in the left and right side members lower part 17B. Thereby, the seat cushion 2 is rotatably coupled to the seat back 3.

[0072] The front ends of the left and right cushion side members 32 are coupled to the front ends of the base side members 11 via the left and right front links 38. One end of the front link 38 is rotatably coupled to the front end of the cushion side member 32 about an axis extending horizontally. The other end of the front link 38 is rotatably coupled to the front end of the base side member 11 about an axis extending horizontally.

[0073] As shown in FIG. 1, the seat back frame 16 is provided with a first driving device 41 for driving the locking device 5 and an electronic control device 42 for controlling the first driving device 41. The electronic control device 42 is composed of a CPU, a non-volatile memory (ROM), a volatile memory (RAM), etc. The first driving device 41 and the electronic control device 42 are arranged one above the other on one side in the left-right direction of the seat back frame 16. In the present embodiment, the first driving device 41 and the electronic control device 42 are arranged one above the other on the right side portion of the seat back frame 16.

[0074] As shown in FIG. 4, the electronic control device 42 is coupled to the plate member 24 via a first bracket 44. The first bracket 44 may be welded to the plate member 24 or may be fastened to the plate member 24 by fastening members such as bolts and nuts. The first bracket 44 is coupled to at least one of the flat portion 24B and the raised portion 24C so as to overlap the flat portion 24B and the raised portion 24C when viewed from a direction orthogonal to the plate member 24. The first bracket 44 has a first portion 44A coupled to the flat portion 24B and a second portion 44B that is offset forward with respect to the first portion 44A and abuts against the raised portion 24C. The second portion 44B may be coupled to the raised portion 24C. The electronic control device 42 is fastened to the second portion 44B by fastening members such as bolts and nuts. The first portion 44A may be coupled to the backside member 17 in addition to the flat portion 24B.

[0075] The electronic control device 42 and the first bracket 44 are disposed at a corner defined by one of the left and right backside members 17 and the upper member 18. In the present embodiment, the electronic control device 42 and the first bracket 44 are disposed at a corner defined by the right backside member 17 and the upper member 18. Further, at least a part of the electronic control device 42 is disposed between the corresponding backside members 17 and the headrest support portion 26 in the left and right directions. In the present embodiment, the upper part of the electronic control device 42 is disposed between the upper part of the right backside member 17 and the right headrest support portion 26. Further, the electronic control device 42 and the first bracket 44 are disposed above the first cross member 21. The electronic control device 42 is disposed in a space defined by the corresponding backside members 17 and headrest support portions 26 in the left and right directions, the upper member 18, and the first cross member 21.

[0076] The outer shape of the electronic control device 42 is preferably formed in a shape that does not give a sense of discomfort to the back of the seated person. For example, the left part of the outer shape of the electronic control device 42 provided on the right side of the seat back 3 is preferably formed by a surface that slopes backward toward the left. Also, the left part of the outer shape of the electronic control device 42 is preferably formed by a smooth curved surface. With this configuration, the electronic control device 42 provided on the seat back 3 can reduce the sense of discomfort given to the back of the seated person.

[0077] As shown in FIGS. 1 and 4, the first drive device 41 includes a first electric motor 41A and an output portion 41B that is displaced in response to the drive of the first electric motor 41A. The first drive device 41 is coupled to the back side member 17 via a second bracket 46. In the present embodiment, the second bracket 46 has a main body portion 46A to which the first drive device 41 is fastened, at least one first protruding piece portion 46B that protrudes rightward from the main body portion 46A and is coupled to the side member upper portion 17A, and at least one second protruding piece portion 46C that protrudes leftward from the main body portion 46A and is coupled to the flat portion 24B or the raised portion 24C of the plate member 24. The main body portion 46A, the first protruding piece portion 46B, and the second protruding piece portion 46C may be formed from separate members and coupled to each other. Also, the main body portion 46A, the first protruding piece portion 46B, and the second protruding piece portion 46C may be formed from a single plate member 24.

[0078] The first protruding piece portion 46B is curved in a semicircular shape and extends along the outer periphery of the side member upper portion 17A. In the present embodiment, two first protruding piece portions 46B are arranged at intervals in the vertical direction. The upper first protruding piece portion 46B is arranged below the end portion of the first cross member 21. The end portion of the first cross member 21 is bent toward the side opposite to the second bracket 46. The two first protruding piece portions 46B may be welded or fastened to the side member upper portion 17A. Also, the second protruding piece portion 46C may be welded or fastened to the plate member 24.

[0079] The second tab portion 46C and the first drive device 41 are disposed below the electronic control device 42. Further, the second tab portion 46C and the first drive device 41 are disposed below the first cross member 21. That is, the first cross member 21 extends horizontally passing between the first drive device 41 and the electronic control device 42.

[0080] As shown in FIG. 4, a relay lever 51 is rotatably provided on the left side of the plate member 24 and on the right side of the left back side member 17. The relay lever 51 is biased to an initial position by a spring (not shown). The first drive device 41 is connected to the relay lever 51 via a first control cable 52 (transmission member). The relay lever 51 is connected to the operation lever 5B of the left lock device 5 via a second control cable 53 (transmission member), and is connected to the operation lever 5B of the right lock device 5 via a third control cable 54 (transmission member).

[0081] A convex portion 5C protruding in the radial direction of the rotation axis of the operation lever 5B is provided at the proximal end of the right operation lever 5B. A sensor 57 for detecting the position of the operation lever 5B is provided at the lower end of the back side member 17. The sensor 57 is disposed around the operation lever 5B on the right side surface of the lower portion 17B of the right side member. The sensor 57 is preferably a limit switch that rotates when pushed by the convex portion 5C of the operation lever 5B. When the seat back 3 is in the seated position, the sensor 57 is disposed between the corresponding back side member 17 and the rear link 37. That is, the sensor 57 is disposed between the right back side member 17 and the right rear link 37. The operation lever 5B is connected to the lower portion 17B of the side member via a spring 5D and is biased toward the initial position.

[0082] As shown in FIGS. 4 and 5, the base 7 is provided with a second driving device 61 for rotating the seat back frame 16 with respect to the base 7. The second driving device 61 connects the base 7 and the seat back 3 and rotates the seat back 3 with respect to the base 7 by expanding and contracting. The second driving device 61 includes a case 61A, a ball screw nut 61B rotatably supported by the case 61A, a ball screw shaft 61C screwed into the ball screw nut 61B, and an electric motor 61D coupled to the case 61A for rotating the ball screw nut 61B. The case 61A is rotatably connected to the base cross member 13 via a hinge 63 about an axis extending horizontally. The hinge 63 includes a lower hinge bracket 63A fastened to the upper channel member 13B of the base cross member 13, and an upper hinge bracket 63B rotatably coupled to the lower hinge bracket 63A about an axis extending horizontally and fastened to the case 61A. A work hole 13C, which is a through hole, is formed at the bottom of the lower channel member 13A of the base cross member 13. A bolt 13D for fastening the upper channel member 13B and the lower hinge bracket 63A is exposed downward through the work hole 13C. Thereby, an operator can perform the fastening work of the upper channel member 13B and the lower hinge bracket 63A through the work hole 13C.

[0083] A bracket 64 extending downward is welded to the lower member 19 of the seat back frame 16. The bracket 64 may be welded to the outer surface of the lower side wall of the rear channel member 19A of the lower member 19. The tip of the ball screw shaft 61C is rotatably coupled to the bracket 64 about an axis extending horizontally. In another embodiment, as shown in FIG. 11, a bent portion 61E bent upward may be provided at the tip of the ball screw shaft 61C. The bent portion 61E may be rotatably coupled to a coupling portion 19F integrally formed with the rear channel member 19A about an axis extending horizontally. The coupling portion 19F may be formed, for example, by raising the rear channel member 19A.

[0084] As shown in FIGS. 5 and 12, the second drive device 61 is disposed rearward of the front end of the seat cushion 2. Specifically, the second drive device 61 is provided on the base cross member 13, which is rearward of the front member 33 of the seat cushion frame 31. The second drive device 61 is disposed on the left portion of the base cross member 13. The axis of the ball screw shaft 61C extends in the front-rear direction. The axis of the ball screw shaft 61C is orthogonal to the rotation axis of the electric motor 61D in a plan view. With this configuration, since the front end of the second drive device 61 is disposed rearward of the front member 33 of the seat cushion 2, it is possible to prevent the legs of the seated person from contacting the electric motor 61D.

[0085] The electric motor 61D is disposed rearward of the base cross member 13. The rotation axis of the electric motor 61D extends in the left-right direction and extends substantially parallel to the base cross member 13. The front end of the electric motor 61D is disposed at a distance from the base cross member 13. With this configuration, the distance between the electric motor 61D and the seat back 3 can be shortened, and the ball screw shaft 61C can be shortened. Thereby, the drive device 61 can be miniaturized.

[0086] The upper wall portion of the electric motor 61D may be above the upper portion of the right portion of the base cross member 13. The upper wall portion of the electric motor 61D may be on the same horizontal plane as the upper portion of the right portion of the base cross member 13. The upper wall portion of the electric motor 61D may be below the upper portion of the right portion of the base cross member 13. With this configuration, the electric motor 61D and the base cross member 13 can be arranged compactly.

[0087] As shown in FIGS. 4 and 9, the electronic control device 42 is connected to the first drive device 41 by the first harness 66, connected to the second drive device 61 by the second harness 67, and connected to the sensor 57 by the third harness 68. The first to third harnesses 66 to 68 are bound to each other in part. A part of the second harness 67 is fastened to the lower member 19 by a plurality of resin fasteners 69 and is arranged along the lower member 19. In other embodiments, a part of the second harness 67 may be fastened to the third cross member 23 by a plurality of resin fasteners 69 and arranged along the third cross member 23.

[0088] Further, the electronic control device 42 is connected to the operation switch 72 by the fourth harness 71 and connected to the power supply 75 by the fifth harness 74. The operation switch 72 outputs a first signal in response to the first operation of the occupant and outputs a second signal in response to the second operation. The first signal is a signal corresponding to an operation of changing the seat 1 from the use form to the storage form, and the second signal is a signal corresponding to an operation of changing the seat 1 from the storage form to the use form.

[0089] Next, the operation of the seat 1 will be described. As shown in FIG. 10(A), when the seat 1 is in the use form, the seat back 3 stands up with respect to the floor 4, and the locking device 5 restricts the rotation of the seat back 3. The seat cushion 2 extends substantially horizontally and is arranged at an interval from the floor 4. When the occupant performs a first operation on the operation switch 72 when the seat 1 is in the use form, a first signal is output to the electronic control device 42. The electronic control device 42 drives and controls the first drive device 41 based on the first signal. Thereby, the first drive device 41 moves the relay lever 51 from the initial position to the drive position by the first control cable 52. When the relay lever 51 moves from the initial position to the drive position, the second control cable 53 and the third control cable 54 pull the left and right operation levers 5B, and the left and right operation levers 5B move from the locked position to the released position. Thereby, the left and right locking devices 5 are released, and the seat back 3 becomes rotatable with respect to the base 7.

[0090] When the right operation lever 5B reaches the release position, the sensor 57 is pushed by the convex portion 5C of the operation lever 5B and outputs a detection signal to the electronic control unit 42. Based on the signal from the sensor 57, the electronic control unit 42 determines that the operation lever 5B has reached the release position, that is, the locking device 5 has been released. When the electronic control unit 42 determines the release of the locking device 5, it drives and controls the electric motor 61D of the second drive device 61 to extend the second drive device 61. When the electric motor 61D rotates, the ball screw nut 61B rotates with respect to the case 61A, and the ball screw shaft 61C protrudes rearward with respect to the case 61A. As a result, as shown in FIG. 10(B), the lower end portion of the seat back 3 is pushed rearward by the second drive device 61, and the upper portion of the seat back 3 rotates forward. At the same time, the seat cushion 2 is pushed by the seat back 3 and moves forward and downward. As a result, the seat 1 is in the storage form. The electronic control unit 42 detects that the ball screw shaft 61C has reached the longest position based on the drive current of the electric motor 61D of the second drive device 61, and stops the drive of the second drive device 61. Further, the electronic control unit 42 measures the elapsed time since it determined that the locking device 5 has been released, and stops the drive of the first drive device 41 when the elapsed time reaches a predetermined time. As a result, due to the biasing force of the springs of the left and right locking devices 5, the locking device 5 changes from the released state to the locked state. As a result, as shown in FIG. 10(C), the seat 1 is maintained in the storage form.

[0091] When the seat 1 is in the storage form and the occupant performs a second operation on the operation switch 72, a second signal is output to the electronic control unit 42. The electronic control unit 42 drives and controls the first drive device 41 based on the second signal. As a result, the first drive device 41 moves the left and right operation levers 5B from the locked position to the released position via the first control cable 52, the relay lever 51, the second control cable 53, and the third control cable 54. As a result, the left and right locking devices 5 are released, and the seat back 3 becomes rotatable with respect to the base 7.

[0092] The electronic control device 42 determines that the operation lever 5B has reached the release position, that is, the locking device 5 has been released, based on the signal from the sensor 57. When the electronic control device 42 determines the release of the locking device 5, it drives and controls the electric motor 61D of the second drive device 61 to contract the second drive device 61. When the electric motor 61D rotates, the ball screw nut 61B rotates with respect to the case 61A, and the ball screw shaft 61C moves forward with respect to the case 61A. As a result, as shown in FIG. 10(B), the lower end of the seat back 3 is pulled forward by the second drive device 61, and the upper part of the seat back 3 rotates backward. At the same time, the seat cushion 2 is pulled by the seat back 3 and moves backward and upward. Thereby, the seat 1 assumes the usage form. The electronic control device 42 detects that the ball screw shaft 61C has reached the shortest position based on the drive current of the electric motor 61D of the second drive device 61, and stops the drive of the second drive device 61. Further, the electronic control device 42 measures the elapsed time since it determined that the locking device 5 has been released, and stops the drive of the first drive device 41 when the elapsed time reaches a predetermined time. As a result, due to the biasing force of the springs of the left and right locking devices 5, the locking device 5 changes from the released state to the locked state. Thereby, as shown in FIG. 10(A), the seat 1 is maintained in the usage form.

[0093] According to the seat 1 according to the embodiment, the electronic control device 42 can be arranged at a position that does not interfere with the operation of the seat 1. By arranging the electronic control device 42 on the seat back 3, the thickness of the seat cushion 2 can be reduced. In addition, a space for the seat cushion 2 to move can be secured below the seat cushion 2. Further, the influence exerted by the electronic control device 42 and the first drive device 41 on the back of the occupant can be suppressed.

[0094] The first bracket 44 that supports the electronic control device 42 is arranged so as to overlap the flat portion 24B and the raised portion 24C in the plate member 24. Thereby, the first bracket 44 is arranged at a portion with high rigidity in the plate member 24, and the first bracket 44 and the electronic control device 42 are stably supported by the seat back frame 16.

[0095] The electronic control device 42 is disposed at a corner defined by the upper member 18 and the backside member 17. Further, the electronic control device 42 is disposed in a space defined by the upper member 18, the backside member 17, the first cross member 21, and the headrest pillar. Therefore, the electronic control device 42 can be disposed by effectively using the space formed by the upper member 18, the backside member 17, and the plate member 24. Further, the influence of the electronic control device 42 on the back of the occupant can be suppressed.

[0096] Since the first drive device 41 is disposed below the electronic control device 42, the electronic control device 42 and the first drive device 41 can be disposed on the seat back 3 with good space efficiency. Further, since the first cross member 21 is disposed between the electronic control device 42 and the first drive device 41, the rigidity of the seat back frame 16 at the portion where the electronic control device 42 and the first drive device 41 are attached can be improved. Since the end of the first cross member 21 coupled to the backside member 17 is bent upward, interference with the second bracket 46 coupled to the backside member 17 can be avoided.

[0097] The seat 200 according to the second embodiment has a different structure around the second drive device 61 as compared with the seat 1 according to the first embodiment. In the following description, only the different configurations will be described, and the description of the same configurations as those of the seat 1 according to the first embodiment will be omitted by referring to the above description.

[0098] As shown in FIGS. 13 and 14, in the seat 200 according to this embodiment, the base cross member 213 is formed of a pipe material having at least one bent portion 214. The left and right ends of the base cross member 213 are coupled to the vertical wall portions 11B of the corresponding base side members 11. The base cross member 213 is partitioned by a plurality of bent portions 214 and has a right portion 213A, a central portion 213B, and a left portion 213C. The right portion 213A, the central portion 213B, and the left portion 213C each extend linearly. The right portion 213A is disposed above the left portion 213C. The central portion 213B is inclined upward toward the right. The left portion 213C is formed longer in the left - right direction than the right portion 213A.

[0099] A bracket 206 is coupled to the left portion 213C of the base cross member 213. The bracket 206 has a main body portion 206A whose surface faces up and down, and left and right side wall portions 206B that extend downward from the left and right side edges of the main body portion 206A. A semi - circular recess 206C is formed at the lower end of the side wall portion 206B. The upper part of the base cross member 213 is received and welded in the recess 206C. A lower hinge bracket 63A is fastened to the main body portion 206A of the bracket 206. With this configuration, the structure of the base cross member 213 can be simplified and the rigidity can be improved. Also, the second drive device 61 can be fixed to the curved base cross member 213 via the bracket 206.

[0100] The lower member 219 of the seat back frame 16 is formed of a channel member having a cross-sectional groove shape that opens forward. The lower member 219 has side wall portions 219A whose surfaces face front and rear, an upper wall portion 219B that extends forward from the upper edge of the side wall portions 219A, and a lower wall portion 219C that extends forward from the lower edge of the side wall portions 219A. The vertical width of the side wall portions 219A is wider than the front-rear width of the upper wall portion 219B, and the vertical width of the side wall portions 219A is wider than the front-rear width of the lower wall portion 219C. The left and right ends of the side wall portions 219A of the lower member 219 are welded inside the edge wall portions 17D of the corresponding lower side members 17B on the left and right. With this configuration, since the lower member 219 is coupled to the back side member 17 at the side wall portions 219A that are wider than the upper wall portion 219B and the lower wall portion 219C, the rigidity of the coupling portion can be improved.

[0101] As shown in FIGS. 14 and 15, a bracket 207 is coupled to the lower member 219. The bracket 207 has a rear wall portion 207A whose surface faces front and rear, and left and right edge wall portions 207B extending forward from the left and right side edges of the rear wall portion 207A. The rear wall portion 207A and the left and right edge wall portions 207B are formed by bending sheet metal. The upper end portion 207C of the rear wall portion 207A extends above the upper end portions 207C of the left and right edge wall portions 207B and is in surface contact with the rear surface of the side wall portion 219A of the lower member 219. The upper end portion 207C of the rear wall portion 207A is welded to the rear surface of the side wall portion 219A of the lower member 219. The upper end portions of the left and right edge wall portions 207B abut against and are welded to the lower surface of the lower wall portion 219C of the lower member 219. The edge wall portions 207B of the bracket 207 extend downward and forward. The left and right edge wall portions 207B face left and right and correspond to each other with a gap therebetween in the left - right direction. The left and right edge wall portions 207B are bent at an intermediate portion in the vertical direction such that the distance between the lower end portions 207D is smaller than the distance between the upper end portions 207C. Support holes 207E penetrating left and right are formed in the lower end portions 207D of the left and right edge wall portions 207B. A shaft 208 is inserted into the support holes 207E. The rear end portion of the ball screw shaft 61C is disposed between the left and right edge wall portions 207B and is rotatably supported by the shaft 208. Since the bracket 207 extends downward and forward, when the seat 200 is in the stored form, the bracket 207 can compactly accommodate the ball screw shaft 61C below the seat back 3.

[0102] As shown in FIG. 16, in an automobile, a luggage compartment 201 is provided behind the seat 200. A floor 4 defining the lower part of the luggage compartment 201 is provided with a recess 220 recessed downward. The recess 220 can accommodate an article 221 such as a tire. A luggage compartment board 202 is provided on the upper surface of the floor 4 so as to cover the recess 220. The luggage compartment board 202 is detachably provided with respect to the floor 4 and extends horizontally. The luggage compartment board 202 is made of, for example, resin.

[0103] A cover 203 is provided at the front edge of the luggage compartment board 202. The cover 203 extends in the left - right direction of the seat 200. When the seat 200 is in the storage form, the front end of the cover 203 is arranged on the back surface of the seat back 3. That is, the cover 203 is provided to cover the gap between the luggage compartment board 202 and the seat back 3. The cover 203 may be integrally formed with the luggage compartment board 202. When the seat 200 is in the storage form, the cover 203 is arranged above the rear end of the ball screw shaft 61C. When the seat 200 is in the use form, the bracket 207 extends forward and downward. Therefore, when the seat 200 is in the storage form, it is possible to avoid the bracket 207 and the rear end of the ball screw shaft 61C from contacting the cover 203. With this configuration, when the seat 200 is in the storage form, the cover 203 can hide the gap between the seat 200 and the luggage compartment board 202 and the rear end of the ball screw shaft 61C.

[0104] As shown in FIG. 13, a sensor 204 is provided on the upper part of the seat cushion 2. Specifically, the sensor 204 is arranged between the upper surface of the pad constituting the seat cushion 2 and the skin material. The sensor 204 is a load sensor for detecting a load. The sensor 204 may be, for example, a piezoelectric element or a membrane switch that deforms according to the load and whose contacts are connected. The sensor 204 is provided to detect whether an object exists on the seat cushion 2. In this embodiment, the sensor 204 is a membrane switch and outputs an ON signal when a load of a predetermined value or more is applied.

[0105] The sensor 204 is connected to the electronic control unit 42. The sensor 204 outputs a signal to the electronic control unit 42 according to the detected pressure. When the electronic control unit 42 determines that an object exists on the seat cushion 2 based on the signal from the sensor 204, it restricts the deformation from the usage form to the storage form. Specifically, when the electronic control unit 42 receives an ON signal from the sensor 204, it prohibits the driving of the first driving device 41. With this configuration, it is possible to prevent the seat 200 from changing to the storage form when an object is placed on the seat cushion 2 or when a seated person is present.

[0106] Alternatively, instead of the sensor 204, another sensor may detect the pinching of an object by the seat cushion 2 and the seat back 3. The sensor may be, for example, a strain sensor 222 provided between the upper hinge bracket 63B and the case 61A as shown in FIG. 17. The strain sensor 222 is a known strain sensor and outputs a signal corresponding to the strain to the electronic control unit 42. When an object is pinched between the seat cushion 2 and the seat back 3, the seat back 3 with respect to the seat cushion 2 is restricted. At this time, since the ball screw shaft 61C tries to move rearward with respect to the case 61A, the strain sensor 222 is compressed between the upper hinge bracket 63B and the case 61A. Thereby, the electronic control unit 42 can detect the pinching of an object by the seat cushion 2 and the seat back 3 based on the signal from the strain sensor 222. By using the strain sensor 222, the sensor 204 can be omitted and the structure of the seat cushion 2 can be simplified. In other embodiments, the electronic control unit 42 may detect the pinching of an object by the seat cushion 2 and the seat back 3 based on the current flowing through the electric motor 61D.

[0107] The sheet 200 is provided with an indicator 205. The indicator 205 is a display device including, for example, an LED or the like. The indicator 205 is preferably arranged at the upper end on the left side of the seat back 3. The indicator 205 is connected to the electronic control device 42. The electronic control device 42 lights up the indicator 205 when the ball screw shaft 61C is in the longest position and the operation lever 5B is in the initial position. With this configuration, the user can visually confirm that the sheet 200 has completely changed to the storage form. In another embodiment, the electronic control device 42 may light up the indicator 205 when the operation lever 5B is not in the initial position. In this case, the user can visually confirm that the locking device 5 is in the released state.

[0108] The manufacturing method of the seats 1 and 200 includes a step of rotatably providing the seat back 3 on the base 7, a step of rotatably providing the seat cushion 2 on the seat back 3, and a step of connecting a drive device 61 for rotating the seat back 3 with respect to the base 7 to the base 7 and the seat back 3 and providing it behind the front end of the seat cushion 2. According to this aspect, the vehicle seats 1 and 200 provided with the second drive device 61 can be unitized. Thereby, the attachment of the vehicle seats 1 and 200 to the vehicle becomes easy.

[0109] Compared with the seats 1 and 200 according to the first and second embodiments, the seat 300 according to the third embodiment has a different internal structure of the seat cushion 2. In the following description, only the different configurations will be described, and the description of the same configurations as those of the seat 1 according to the first embodiment will be omitted by referring to the above description.

[0110] As shown in FIGS. 18 and 19, the sheet 300 has a sheet-like member 301 instead of the center plate 35. The sheet-like member 301 extends longitudinally and is spanned between the front member 33 and the rear member 34. The sheet-like member 301 has a surface facing up and down, and its front edge 301A and rear edge 301B extend horizontally. The sheet-like member 301 has flexibility and may be formed of, for example, woven fabric. The sheet-like member 301 may be formed of, for example, PET resin or the like.

[0111] Reinforcing threads 302 may be sewn to the sheet-like member 301. The reinforcing threads 302 improve the tensile strength of the sheet-like member 301. The reinforcing threads 302 may have, for example, left and right side portions 302A extending longitudinally and a central portion 302B extending from the front end of one side portion 302A to the rear end of the other side portion 302A. The left and right side portions 302A and the central portion 302B are formed linearly, and the reinforcing threads 302 may be arranged in an N shape.

[0112] As shown in FIGS. 20 and 21, the sheet-like member 301 has a plurality of front-side holding holes 303A in the form of cylinders extending horizontally at its front edge. The front-side holding holes 303A may be formed by folding back the front edge 301A of the sheet-like member 301 and sewing it to the main body of the sheet-like member 301. A gap is formed between adjacent front-side holding holes 303A. Front-side shafts 304A extending horizontally are inserted into the respective front-side holding holes 303A. The front-side shafts 304A have bent portions 305A bent forward at both their left and right ends. The bent portions 305A determine the left and right positions of the front-side shafts 304A with respect to the respective front-side holding holes 303A.

[0113] The sheet-like member 301 has a plurality of rear-side holding holes 303B in a cylindrical shape extending left and right at its rear edge. The rear-side holding holes 303B may be formed by folding back the rear edge 301B of the sheet-like member 301 and sewing it to the main body of the sheet-like member 301. A gap is formed between adjacent rear-side holding holes 303B. A rear-side shaft 304B extending left and right is inserted into each rear-side holding hole 303B. The rear-side shaft 304B has bent portions 305B bent rearward at both its left and right ends. The bent portions 305B determine the left and right positions of the rear-side shaft 304B with respect to each rear-side holding hole 303B.

[0114] The front member 33 has a plurality of front-side locking portions 306A. The plurality of front-side locking portions 306A are arranged side by side left and right. Each front-side locking portion 306A may be a protruding piece extending forward and downward from the front member 33. Each front-side locking portion 306A may be formed by cutting and raising the front member 33 downward. The rear member 34 has a plurality of rear-side locking portions 306B. The plurality of rear-side locking portions 306B are arranged side by side left and right. Each rear-side locking portion 306B may be a protruding piece extending rearward and downward from the rear member 34. Each rear-side locking portion 306B may be formed by cutting and raising the rear member 34 downward.

[0115] The front-side shaft 304A is exposed to the outside between each front-side holding hole 303A and is locked to the plurality of front-side locking portions 306A. Similarly, the rear-side shaft 304B is exposed to the outside between each rear-side holding hole 303B and is locked to the plurality of front-side locking portions 306A. In a state where the sheet-like member 301 is elastically deformed and extended back and forth, the front-side shaft 304A may be locked to the plurality of front-side locking portions 306A, and the rear-side shaft 304B may be locked to the plurality of rear-side locking portions 306B.

[0116] A pad 307 is provided on the upper part of the seat cushion frame 31. The pad 307 is formed of a resin material having flexibility such as foamed urethane. The sheet-like member 301 supports the central portion of the pad 307 from below.

[0117] A sensor 309 is provided on the upper part of the seat cushion 2. Specifically, the sensor 309 is disposed between the upper surface of the pad 307 that constitutes the seat cushion 2 and the skin material 308. The sensor 309 is a load sensor that detects a load. The sensor 309 may be, for example, a piezoelectric element or a membrane switch that deforms according to a load and has contacts connected. The sensor 309 is provided to detect whether an occupant is seated on the seat cushion 2. In the present embodiment, the sensor 309 is a membrane switch and outputs an ON signal when a load equal to or greater than a predetermined value is applied. The sensor 309 is connected to the electronic control unit 42 via a sensor harness 310.

[0118] The pad 307 has a first harness hole 311 that penetrates vertically. The sheet-like member 301 has a second harness hole 312 that penetrates vertically. A grommet 314 is attached to the edge of the second harness hole 312. The sensor harness 310 extending from the sensor 309 passes through the first harness hole 311 and the second harness hole 312 and extends downward from the sheet-like member 301. The first harness hole 311 and the second harness hole 312 are preferably arranged at overlapping positions when viewed from above. That is, it is preferable that the first harness hole 311 and the second harness hole 312 communicate with each other. Further, when the first harness hole 311 and the second harness hole 312 are offset from each other when viewed from above, a harness receiving groove 307A extending from the first harness hole 311 to the second harness hole 312 may be formed on the bottom surface of the pad 307. The harness receiving groove 307A receives the sensor harness 310 extending from the first harness hole 311 to the second harness hole 312.

[0119] The sensor harness 310 extending downward from the second harness hole 312 extends along the base cross member 13 (213) toward the second drive device 61 side. The sensor harness 310 is coupled to the base cross member 13 (213) by a resin fastener 69 or the like at one or more portions. Also, a part of the sensor harness 310 is bundled together with the second harness 67. The sensor harness 310 extends along with the second harness 67 to the lower member 19 (219), and then extends to the electronic control unit 42.

[0120] As shown in FIG. 22, the seat 300 has a regulating portion 315 that protrudes forward from the seat back 3 in the use position. The regulating portion 315 regulates so as to suppress the load applied to the sensor 309 by the seat back 3 to a predetermined value or less when the seat 300 is in the storage position. The regulating portion 315 is composed of a pad 307 and a skin material 308 covering the pad 307, and may be integrally formed with the seat back 3.

[0121] The regulating portion 315 may be, for example, side support portions 316 provided on the left and right side portions of the seat back 3. The left and right side support portions 316 protrude forward from the left and right side portions on the front surface of the seat back 3. That is, on the front surface of the seat back 3, the portions where the left and right side support portions 316 are provided protrude forward with respect to the central portion in the left - right direction of the seat back 3. The left and right side support portions 316 extend vertically. When the seat 300 is in the storage position, by the left and right side support portions 316 abutting against the left and right side portions of the seat cushion 2, a gap is formed between the central portion in the left - right direction of the seat back 3 and the upper surface of the seat cushion 2. Thereby, a load is prevented from being applied to the sensor 309. Thereby, it is possible to prevent the sensor 309 from being erroneously detected due to the load from the seat back 3.

[0122] The restricting part 315 may be, for example, a headrest 317 provided at the upper part of the seat back 3. The lower part of the headrest 317 may be disposed on the front surface of the seat back 3. That is, the headrest 317 has a portion disposed forward of the front surface of the seat back 3. When the seat 300 is in the storage position, the headrest 317 abuts against the front portion of the seat cushion 2, thereby forming a gap between the front surface of the seat back 3 and the upper surface of the seat cushion 2. Thereby, a load is prevented from being applied to the sensor 309. Thereby, it is possible to prevent the sensor 309 from being erroneously detected due to the load from the seat back 3.

[0123] Since the seat 300 according to the third embodiment has the flexible sheet-like member 301, the seat cushion 2 can give a flexible feeling to the occupant. Since the second harness hole 312 is provided in the sheet-like member 301, the sensor harness 310 extending from the sensor 309 can extend below the sheet-like member 301 without interfering with the sheet-like member 301. Further, by attaching the grommet 314 to the edge of the second harness hole 312, it is possible to prevent the edge of the second harness hole 312 from being damaged by the contact of the sensor harness 310. Furthermore, by providing the grommet 314, it is possible to prevent the sensor harness 310 from being damaged by contact with the edge of the second harness hole 312.

[0124] The seat cushion 2 of the seat 300 according to the third embodiment is preferably manufactured by a manufacturing method having a step of bridging the sheet-like member 301 between the front member 33 and the rear member 34, and a step of supporting the pad 307 provided with the sensor 309 on the seat cushion frame 31 and the sheet-like member 301.

[0125] The seat 400 according to the fourth embodiment has a different layout of the sensor harness 310 below the seat cushion 2 compared to the seat 300 according to the third embodiment. Further, the seat 400 does not have the second harness hole 312.

[0126] As shown in FIG. 23, the sensor harness 310 passes through the first harness hole 311 and reaches the upper surface of the sheet-like member 301, and then passes between the pad 307 and the sheet-like member 301 to reach the side edge of the sheet-like member 301. A harness receiving groove 307A extending from the first harness hole 311 toward at least one of the cushion side members 32 is formed on the bottom surface of the pad 307, and the sensor harness 310 may be disposed in the harness receiving groove 307A. Then, the sensor harness 310 passes through the space between the sheet-like member 301 and one of the left and right cushion side members 32 and extends downward. Then, the sensor harness 310 extends along the base cross member 13(213) toward the second drive device 61 side. The sensor harness 310 is coupled to the base cross member 13(213) by a resin fastener 69 or the like at one or more portions. Also, a part of the sensor harness 310 is bundled together with the second harness 67. The sensor harness 310 extends together with the second harness 67 to the lower member 19(219), and then extends to the electronic control device 42.

[0127] The cushion side member 32 may be provided with a resin cover 418 extending in the front-rear direction. The cover 418 is provided at least on the inner surface 32A of the cushion side member 32 in the left-right direction. The cover 418 has an upper surface portion 418A facing up and a hanging portion 418B extending downward along the cushion side member 32 from the upper surface portion 418A. The cover 418 has a convex boss (not shown) protruding from the back surface of the hanging portion 418B and contacting the inner surface 32A at the tip. The sensor harness 310 may extend downward through the space between the side edges of the sheet-like member 301 facing each other in the left-right direction from the side edge of the sheet-like member 301 and the cover 418. By passing the sensor harness 310 between the lower surface of the pad 307 and the upper surface of the sheet-like member 301, the second harness hole 312 can be omitted from the sheet-like member 301. By omitting the second harness hole 312 from the sheet-like member 301, the tensile strength of the sheet-like member 301 can be improved. Also, by providing the cover 418 on the cushion side member 32, contact between the sensor harness 310 and the cushion side member 32 can be avoided, and wear of the sensor harness 310 can be suppressed.

[0128] Compared with the third embodiment, the seat 500 according to the fifth embodiment has a different structure of the seat cushion frame 31 and the sheet-like member 301. Also, the seat cushion 2 has a support member 319. In the following description, only the different configurations will be described, and the description of the same configurations as those of the seat 300 according to the third embodiment will be omitted by referring to the above description.

[0129] As shown in FIG. 25, the seat 500 has a middle member 520 behind the front member 33. The middle member 520 extends left and right behind the front member 33 and is coupled to the left and right side members 32. The middle member 520 may be formed of, for example, a pipe material having a circular cross section. Similarly, the rear member 521 may be formed of a pipe material having a circular cross section.

[0130] As shown in FIGS. 24 to 26, the sheet 500 has a support member 522. The support member 522 extends longitudinally and is spanned between the middle member 520 and the rear member 521. The support member 522 has a surface facing up and down, and its front edge and rear edge extend horizontally. The support member 522 is flexible and is formed of, for example, resin. The support member has, in order from the front side, a front portion 522A, a middle portion 522B, and a rear portion 522C. The support member 522 is supported by the middle member 520 at the front portion 522A and by the rear member 521 at the rear portion 522C. The middle portion 522B extends substantially horizontally, the front portion 522A extends forward and upward from the middle portion 522B toward the front member 33, and the rear portion 522C extends rearward and upward from the middle portion 522B toward the rear member 521. The horizontal width of the middle portion 522B may be set smaller than the respective horizontal widths of the front portion 522A and the rear portion 522C. In the present embodiment, the middle portion 522B is formed in a triangle with a smaller horizontal width toward the front. Also, each of the front portion 522A and the rear portion 522C is formed in a substantially rectangular shape. The horizontal width of the front portion 522A is formed smaller than the horizontal width of the rear portion 522C. At least one cutout hole 523 may be formed in each of the front portion 522A, the middle portion 522B, and the rear portion 522C. The shapes of the front portion 522A, the middle portion 522B, the rear portion 522C, and the cutout hole 523 can be arbitrarily set.

[0131] A right extension piece 532A extending rightward and upward from the right edge of the rear portion 522C is provided at the right portion of the rear portion 522C. A left extension piece 532B extending leftward and upward from the left edge of the rear portion 522C is provided at the left portion of the rear portion 522C. The right extension piece 532A and the left extension piece 532B are arranged so as to overlap from above the rear portion of the cushion side member 32. At this time, the sensor harness 310 may pass through the second harness hole 312 in order to prevent damage caused by contact with the right extension piece 532A and the left extension piece 532B.

[0132] At the front edge of the front portion 522A of the support member 522, a plurality of first hook portions 524 that engage with the middle member 520 are provided. Each of the first hook portions 524 is formed in a downwardly open semi-circular shape when viewed from the left-right direction. At the rear edge of the rear portion 522C of the support member 522, a second hook portion 525 that engages with the rear member 521 is provided. The second hook portion 525 extends left and right along the rear edge of the rear portion 522C of the support member 522. The second hook portion 525 is formed in a downwardly open semi-circular shape when viewed from the left-right direction. By engaging the plurality of first hook portions 524 with the middle member 520 and engaging the second hook portion 525 with the rear member 521, the support member 522 is spanned between the middle member 520 and the rear member 521.

[0133] Also, a sheet-like member 301 is spanned between the middle member 520 and the rear member 521. At least one front locking portion 526A is provided at the front edge 301A of the sheet-like member 301. The front locking portion 526A is formed by bending a metal rod. By folding back and sewing the front edge 301A of the sheet-like member 301, a plurality of front loop portions 527A are formed. Each front loop portion 527A extends left and right. The front locking portion 526A has a shaft portion 528 rotatably supported by the front loop portion 527A, and left and right third hook portions 529 extending forward from both ends of the shaft portion 528. The third hook portion 529 is formed in a downwardly open semi-circular shape when viewed from the left-right direction.

[0134] At least one rear locking portion 526B is provided at the rear edge 301B of the sheet-like member 301. The rear locking portion 526B is formed by bending a metal rod. By folding back and sewing the rear edge 301B of the sheet-like member 301, a plurality of rear loop portions 527B are formed. Each rear loop portion 527B extends left and right. The rear locking portion 526B has a shaft portion 531 rotatably supported by the rear loop portion 527B, and left and right fourth hook portions 530 extending forward from both ends of the shaft portion 531. The fourth hook portion 530 is formed in a downwardly open semi-circular shape when viewed from the left-right direction.

[0135] The front locking portion 526A of the sheet-like member 301 is locked to the first hook portion 524 of the support member 522 and is locked to the middle member 520 via the first hook portion 524. On the upper surface of the first hook portion 524 of the support member 522, a front engaging groove 524A for receiving the third hook portion 529 is formed. The front engaging groove 524A extends back and forth along the upper surface of the first hook portion 524. When each third hook portion 529 fits into the corresponding front engaging groove 524A, the position of the front locking portion 526A in the left-right direction with respect to the first hook portion 524 is determined.

[0136] The rear locking portion 526B of the sheet-like member 301 is locked to the second hook portion 525 of the support member 522 and is locked to the rear member 521 via the second hook portion 525. On the upper surface of the second hook portion 525 of the support member 522, a rear engaging groove 525A for receiving the fourth hook portion 530 is formed. The rear engaging groove 525A extends back and forth along the upper surface of the second hook portion 525. When each fourth hook portion 530 fits into the corresponding rear engaging groove 525A, the position of the rear locking portion 526B in the left-right direction with respect to the second hook portion 525 is determined.

[0137] In a state where no load is applied to the upper surface of the seat cushion 2, the central portion 301C of the sheet-like member 301 in the front-rear direction is at a position separated from the central portion 522D of the support member 522. When the load applied to the upper surface of the seat cushion 2 increases, the sheet-like member 301 deflects downward and the sheet-like member 301 is supported on the upper surface of the support member 522.

[0138] When viewed from the up-down direction, it is preferable that the cutout hole 523 of the support member 522 is disposed at a position overlapping the second harness hole 312 of the sheet-like member 301. Thereby, the sensor harness 310 that has passed downward through the second harness hole 312 can be extended downward of the support member 522 through the cutout hole 523. That is, the cutout hole 523 functions as a harness hole for passing the sensor harness 510.

[0139] By the support member 522 supporting the sheet-like member 301, the load that the seat cushion 2 can support can be increased. Since the support member 522 is provided with a cutout hole 523, the arrangement of the sensor harness 310 is easy.

[0140] With the above, the description of the specific embodiments is completed, but the present invention can be widely modified and implemented without being limited to the above embodiments.

Explanation of Reference Numerals

[0141] 1: Seat 2: Seat cushion 3: Seat back 4: Floor 5: Locking device 5A: Operating shaft 5B: Operating lever 5C: Protrusion 7: Base 16: Seat back frame 17: Back side member 18: Upper member 19: Lower member 21: First cross member 21A: End portion 24: Plate member 24B: Flat surface portion 24C: Raised portion 26: Headrest support portion 37: Rear link 41: First drive device 41A: First electric motor 42: Electronic control device 44: First bracket 46: Second bracket 57: Sensor 61: Second drive device 67: Second harness 202: Cargo compartment board 203: Cover 204: Sensor 205: Indicator 206: Bracket 207: Bracket 213: Base cross member 214: Bent portion 219: Lower member according to the second embodiment 301: Sheet-like member 307: Pad 307A: Harness receiving hole 308: Skin material 309: Sensor 310: Sensor harness 311: First harness hole 312: Second harness hole 313: Third harness hole 314: grommet 315: Regulation part 316: Side support part 317: Headrest 418: Cover 522: Support member

Claims

1. A vehicle seat having a seat cushion and a seat back, wherein the seat cushion has a seat cushion frame, a pad supported by the seat cushion frame, and a skin material covering the pad, the seat cushion frame has left and right side members extending in the front-rear direction, a front member extending in the left-right direction and coupled to the front portions of the left and right side members, and a rear member extending in the left-right direction and coupled to the rear portions of the left and right side members, a sheet-like member that extends in the front-rear direction, has a surface facing up and down, and has flexibility is spanned between the front member and the rear member, at least a part of the pad is supported from below by the sheet-like member, an occupant detection sensor is provided in the pad, the occupant detection sensor is provided on the upper surface of the pad, a harness connected to the occupant detection sensor passes through a first hole penetrating the pad vertically and passes through a gap between the sheet-like member and the side member, and extends downward from the occupant detection sensor below the sheet-like member, a vehicle seat.

2. a resin cover is attached to the side member, The vehicle seat according to claim 1, wherein the harness passes through a gap between the sheet-like member and the cover and extends downward from the occupant detection sensor below the sheet-like member.

3. A vehicle seat having a seat cushion and a seat back, wherein the seat cushion has a seat cushion frame, a pad supported by the seat cushion frame, and a skin material covering the pad, the seat cushion frame has left and right side members extending in the front-rear direction, a front member extending in the left-right direction and coupled to the front portions of the left and right side members, and a rear member extending in the left-right direction and coupled to the rear portions of the left and right side members, a sheet-like member that extends in the front-rear direction, has a surface facing up and down, and has flexibility is spanned between the front member and the rear member, at least a part of the pad is supported from below by the sheet-like member, an occupant detection sensor is provided in the pad, the seat back rotates between a use position extending upward from the rear portion of the seat cushion and a storage position overlapping the upper side of the seat cushion by rotating forward from the use position. At least one of the seat cushion and the seat back is provided with a regulating portion that regulates the position of the seat back at the storage position with respect to the seat cushion. A vehicle seat in which, when the seat back is in the storage position, the load applied by the seat back to the occupant detection sensor is suppressed to a predetermined value or less by the regulating portion. **Claim 4** The seat back has left and right side support portions that protrude forward from left and right side portions at the use position. The vehicle seat according to claim 3, wherein the regulating portion includes the side support portions. **Claim 5** A headrest is provided on the seat back. The vehicle seat according to claim 3 or claim 4, wherein the regulating portion includes the headrest. **Claim 6** The occupant detection sensor is provided on the upper surface of the pad. A harness connected to the occupant detection sensor passes through a first hole that vertically penetrates the pad and a second hole that vertically penetrates the seat-like member, and extends downward from the occupant detection sensor below the seat-like member. The vehicle seat according to claim 3. **Claim 7** The vehicle seat according to claim 6, wherein a grommet is attached to an edge portion of the second hole. **Claim 8** A support member having flexibility and supporting from below the seat-like member is provided between the front member and the rear member. The vehicle seat according to claim 6 or claim 7, wherein the harness passes through a third hole provided in the support member and extends downward from the occupant detection sensor below the support member. **Claim 9** A vehicle seat having a seat cushion and a seat back, The seat cushion includes a seat cushion frame, a pad supported by the seat cushion frame, and a skin material covering the pad. The seat cushion frame has left and right side members extending in the front-rear direction, a front member extending in the left-right direction and coupled to the front portions of the left and right side members, and a rear member extending in the left-right direction and coupled to the rear portions of the left and right side members. A seat-like member having flexibility and having a surface facing up and down and extending in the front-rear direction is spanned between the front member and the rear member. At least a part of the pad is supported from below by the seat-like member. An occupant detection sensor is provided on the pad. The occupant detection sensor is provided on the upper surface of the pad. The harness connected to the occupant detection sensor passes through a first hole penetrating the pad vertically and a second hole penetrating the sheet-like member vertically, and extends downward from the occupant detection sensor below the sheet-like member. The seat back is rotatably supported by a base provided on the floor. The seat cushion is rotatably supported by the seat back. The base has left and right base side members extending in the front-rear direction and a base cross member extending in the left-right direction and coupled to the left and right base side members. A vehicle seat in which the harness is fixed to the base cross member.

10. A method for manufacturing a vehicle seat having a seat cushion and a seat back, wherein the seat cushion has a seat cushion frame, a pad supported by the seat cushion frame, and a skin material covering the pad. The seat cushion frame has left and right side members extending in the front-rear direction, a front member extending in the left-right direction and coupled to the front portions of the left and right side members, and a rear member extending in the left-right direction and coupled to the rear portions of the left and right side members. A step of bridging a sheet-like member having flexibility and having a surface facing up and down and extending in the front-rear direction between the front member and the rear member. A step of supporting the pad provided with the occupant detection sensor on its upper surface on the seat cushion frame and the sheet-like member. A method for manufacturing a vehicle seat, comprising a step of arranging a harness connected to the occupant detection sensor to pass through a first hole penetrating the pad vertically and through a gap between the sheet-like member and the side member and extending downward from the occupant detection sensor below the sheet-like member.

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