Vehicle seat and method of making 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 technology]

[0002] Patent Document 1 discloses a seat cushion for a vehicle seat. 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 stretched across the front and rear members, a pad supported from below by the seat cushion frame and the sheet-like member, and a covering material covering the pad. The sheet-like member is made of flexible woven fabric such as cloth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-240240 Summary of the Invention [Problem to be solved by the invention]

[0004] In vehicle seats, an occupant detection sensor is often provided on the seat cushion to determine whether an occupant is seated. Therefore, there is a demand for providing an occupant detection sensor also on a seat cushion having a sheet-like member.

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

[0006] In order to solve the above-mentioned 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) has a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a covering material (308) covering the pad (307), and the seat cushion frame (31) has left and right side members (32) extending in the front-rear direction and left and right side members (32) extending in the left and right direction. The vehicle comprises a front member (33) connected to the front portions of the side members (32), and a rear member (34) extending left and right and connected to the rear portions of the left and right side members (32). A flexible sheet-like member (301) extending front to back and having a surface facing up and down is spanned between the front member (33) and the rear member (34). At least a portion of the pad (307) is supported from below by the sheet-like member (301), and the pad (307) is provided with an occupant detection sensor (309).

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

[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) that penetrates the pad (307) vertically and also passes through a second hole (312) that penetrates the sheet-like member (301) vertically, and extends from the occupant detection sensor (309) below the sheet-like member (301).

[0009] 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).

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

[0011] According to this embodiment, it is possible to prevent damage to the edge of the second hole (312) due to contact with the harness (310).

[0012] In the above aspect, a flexible support member (522) that supports the sheet-like member (301) from below 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 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 embodiment, 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 (311) that penetrates the pad (307) from top to bottom, and passes through the gap between the sheet-like member (301) and the side member (32), extending 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 embodiment, 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 from the occupant detection sensor (309) below the sheet-like member (301).

[0017] According to this embodiment, 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 in which it extends upward from the rear of the seat cushion (2) and a storage position in which it overlaps the upper side of the seat cushion (2) by rotating forward from the use position, and a regulating portion (315) that regulates the position of the seat back (3) in the storage position relative to the seat cushion (2) is provided on at least one of the seat cushion (2) and the seat back (3), and the regulating portion (315) suppresses the load that the seat back (3) applies to the occupant detection sensor (309) to a predetermined value or less when the seat back (3) is in the storage position.

[0019] According to this embodiment, when the seat back (3) is in the stowed position, the occupant detection sensor (309) can be prevented from being pressed by the seat back (3) and making an erroneous detection.

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

[0021] According to this embodiment, the side support portion (316) can be used to suppress the load applied from the seat back (3) to the occupant detection sensor (309).

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

[0023] According to this embodiment, the headrest (317) can be used to suppress the load applied from the seat back (3) to the occupant detection sensor (309).

[0024] In the above embodiment, the seat back (3) is rotatably supported on a base (7) provided on the floor (4), the seat cushion (2) is rotatably supported on the seat back (3), the base (7) has left and right base side members (11) extending in the front-rear direction and base cross members (13) extending in the left-right direction and connected 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 embodiment, 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) placed on the pad (307), and the seat cushion frame (31) has left and right side members (32) extending in the front-rear direction and a cover (418) for covering the left and right side members (32) extending in the left and right direction. The method includes a step of bridging a flexible sheet-like member (301) that extends in the front-rear direction and has a surface facing up and down between the front member (33) and the rear member (34), the front member (33) being connected to the front portions of the side members (32), and a step of supporting the pad (307) on which an occupant detection sensor (309) is provided on the seat cushion frame (31) and the sheet-like member (301).

[0027] According to this embodiment, the vehicle seat (300, 400, 500) having the sheet-like member (301) and the occupant detection sensor (309) can be manufactured by a simple procedure. [Effects 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) has a seat cushion frame (31), a pad (307) supported by the seat cushion frame (31), and a covering material (308) covering the pad (307), and the seat cushion frame (31) has left and right side members (32) extending in the front-rear direction and left and right side members (32) extending in the left and right direction. The vehicle has a front member (33) connected to the front portions of the left and right side members (32), and a rear member (34) extending left and right and connected to the rear portions of the left and right side members (32). A flexible sheet-like member (301) extending front to back and having a surface facing up and down is suspended between the front member (33) and the rear member (34). At least a portion of the pad (307) is supported from below by the sheet-like member (301), and the pad (307) is provided with an occupant detection sensor (309).

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

[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 penetrates the pad (307) vertically and also passes through a second hole (312) that penetrates the sheet-like member (301) vertically, and extends from the occupant detection sensor (309) below the sheet-like member (301).

[0031] 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).

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

[0033] According to this embodiment, it is possible to prevent damage to the edge of the second hole (312) due to contact with the harness (310).

[0034] In the above aspect, a flexible support member (522) that supports the sheet-like member (301) from below 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 from the occupant detection sensor (309) below the support member (522).

[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 embodiment, 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 (311) that penetrates the pad (307) from top to bottom, and passes through the gap between the sheet-like member (301) and the side member (32), extending 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 embodiment, 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 from the occupant detection sensor (309) below the sheet-like member (301).

[0039] According to this embodiment, 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 in which it extends upward from the rear of the seat cushion (2) and a storage position in which it overlaps the upper side of the seat cushion (2) by rotating forward from the use position, and a regulating portion (315) that regulates the position of the seat back (3) in the storage position relative to the seat cushion (2) is provided on at least one of the seat cushion (2) and the seat back (3), and the regulating portion (315) suppresses the load that the seat back (3) applies to the occupant detection sensor (309) to a predetermined value or less when the seat back (3) is in the storage position.

[0041] According to this embodiment, when the seat back (3) is in the stowed position, the occupant detection sensor (309) can be prevented from being pressed by the seat back (3) and making an erroneous detection.

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

[0043] According to this embodiment, the side support portion (316) can be used to suppress the load applied from the seat back (3) to the occupant detection sensor (309).

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

[0045] According to this embodiment, the headrest (317) can be used to suppress the load applied from the seat back (3) to the occupant detection sensor (309).

[0046] In the above embodiment, the seat back (3) is rotatably supported on a base (7) provided on the floor (4), the seat cushion (2) is rotatably supported on the seat back (3), the base (7) has left and right base side members (11) extending in the front-rear direction and base cross members (13) extending in the left-right direction and connected 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 embodiment, 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), 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) placed on the pad (307), and the seat cushion frame (31) has left and right side members (32) extending in the front-rear direction and a cover (418) for covering the left and right side members (32) extending in the left and right direction. The method includes a step of bridging a flexible sheet-like member (301) that extends in the front-rear direction and has a surface facing up and down between the front member (33) and the rear member (34), the front member (33) being connected to the front portions of the side members (32), and a step of supporting the pad (307) on which an occupant detection sensor (309) is provided on the seat cushion frame (31) and the sheet-like member (301).

[0049] According to this embodiment, the vehicle seat (300, 400, 500) having the sheet-like member (301) and the occupant detection sensor (309) can be manufactured by a simple procedure. [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 is a perspective view of a frame of a seat according to an embodiment; [Figure 2] Side view of the seat frame [Figure 3] FIG. 1 is a perspective view of the seat frame from below and behind, showing a state in which the plate member has been removed; [Figure 4] FIG. 1 is a perspective view showing a lower portion of a seat back frame. [Figure 5] Perspective view of a second drive device [Figure 6] Front view showing the lower part of the seatback frame [Figure 7] FIG. 10 is a cross-sectional view showing a connection portion between the lower member and the second drive device. [Figure 8] A side view showing the lower end of the lower part of the side member [Figure 9] An explanatory diagram showing the connection structure of the control cable and harness [Figure 10] Side views showing the seat in (A) the use position, (B) the transition from the use position to the storage position, and (C) the storage position. [Figure 11] 10 is a cross-sectional view showing a connection portion between a lower member and a second drive device according to a modified embodiment; [Figure 12] Front view of the seat bottom [Figure 13] Perspective view of the seat [Figure 14] FIG. 10 is a perspective view showing a base cross member and its surrounding structure according to a second embodiment. [Figure 15] (A) Rear view and (B) side view of the bracket [Figure 16] Cross-sectional view showing the main part of the seat in the stored state [Figure 17] A perspective view of a second drive unit equipped with a strain sensor. [Figure 18] 10 is a perspective view of the inside of a seat cushion according to a third embodiment; [Figure 19] Plan view of the inside of the seat cushion according to the third embodiment [Figure 20] FIG. 10 is a perspective view of a seat cushion frame according to a third embodiment, seen from below and rearward, illustrating a connection portion between a sheet-like member and a lower member; [Figure 21] Cross-sectional view of a seat cushion according to a third embodiment [Figure 22] FIG. 10 is a perspective view of a seat according to a third embodiment; [Figure 23] FIG. 10 is a view showing a cover for a seat cushion frame according to a fourth embodiment; [Figure 24] FIG. 13 is a perspective view showing a sheet-like member and a support member according to a fifth embodiment. [Figure 25] 10 is a plan view of the inside of a seat cushion according to a fifth embodiment. [Figure 26] 10 is a cross-sectional view of a seat cushion according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0051] Hereinafter, with reference to the drawings, an embodiment in which a vehicle seat 1, 200 according to the present invention is applied to a rear seat (including the second and third rows) of an automobile will be described. As will be described later, the vehicle seat 1, 200 changes its configuration between a usage configuration (seating configuration) and a storage configuration. Unless otherwise specified, the shape and orientation of each component of the vehicle seat 1, 200 will be described based on the usage configuration. Furthermore, when it is stated that each component is connected, the manner of connection includes welding and fastening unless otherwise specified.

[0052] As shown in Figures 1 and 10, the seat 1 has a seat cushion 2 and a seat back 3. The seat back 3 is rotatably supported on a floor 4, and the seat cushion 2 is rotatably supported on the seat back 3. A locking device 5 is provided between the seat back 3 and the floor 4 to selectively restrict rotation of the seat back 3 relative to the floor 4. When the seat 1 is in its usage mode, the seat back 3 stands up relative to the floor 4, and the seat cushion 2 is spaced upward from the floor 4. When the seat 1 is in its usage mode, the seat back 3 rotates forward to change the seat 1 into its storage mode. When the seat 1 changes from its usage mode to its storage mode, the seat cushion 2 moves downward and approaches the floor 4. When the seat 1 is in its storage mode, the seat back 3 extends approximately horizontally and overlaps the upper part of the seat cushion 2.

[0053] As shown in Figures 1 and 2, a base 7 is provided on the floor 4. The base 7 includes left and right base side members 11 that extend in the front-to-rear direction on the upper surface of the floor 4 and are connected to the floor 4, left and right base pillars 12 that extend upward from the rear ends of the left and right base side members 11, and a base cross member 13 that extends left and right and is connected to the left and right base side members 11. Each of the base side members 11, base pillars 12, and base cross member 13 is formed from sheet metal.

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

[0055] The base cross member 13 has a lower channel member 13A with a groove-shaped cross section that opens upward, and an upper channel member 13B with a groove-shaped cross section 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 may be fitted inside the lower channel member 13A. The left and right ends of the lower channel member 13A are connected to the corresponding vertical wall portion 11B of the base side member 11. The left end of the upper channel member 13B is connected to the left vertical wall portion 11B. The right end of the upper channel member 13B is located leftward of the center of the lower channel member 13A in the left-right direction. The bottoms of the lower channel member 13A and the upper channel member 13B may be provided with an uneven structure such as a bead to increase 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 on the seat back frame 16, and the pad and the seat back frame 16 are covered with an upholstery 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 and spaced apart from each other on the left and right. The upper member 18 extends horizontally and is connected to the upper ends of the left and right back side members 17. The lower member 19 extends horizontally below the upper member 18 and is connected to the lower parts of the left and right back side members 17. The first to third cross members 21 to 23 extend horizontally between the upper member 18 and the lower member 19 and are connected to intermediate portions of the left and right back side members 17.

[0057] The left and right back side members 17 each have a side-member upper portion 17A and a side-member lower portion 17B connected to the side-member upper portion 17A. The left and right side-member upper portions 17A and the upper member 18 are formed by bending a continuous pipe material. The left and right side-member lower portions 17B are formed from sheet metal and have a main portion 17C with surfaces facing left and right, and edge wall portions 17D bent inwardly to the left and right from the edges of the main 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 spaced apart from each other and joined to the front surface of the center portion in the left-right direction of the upper member 18. 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 19A with a groove-shaped cross section that opens forward, and a front channel 19B with a groove-shaped cross section that also opens forward. The length of the front channel 19B in the left-right direction is shorter than the length of the rear channel 19A in the left-right direction. The rear channel 19A and the front channel 19B cooperate to form a closed cross-sectional structure. The front channel 19B may be fitted inside the rear channel 19A. The left and right ends of the rear channel 19A are disposed inside the corresponding edge wall portions 17D of the side-member lower portions 17B on the left and right and are welded to the edge wall portions 17D. The ends of the edge wall portions 17D of the side-member lower portions 17B may be welded to the rear surface of the rear channel 19A. The ends of the rear channel 19A have extension portions 19C to increase the contact area with the edge wall portions 17D of the side-member lower portions 17B. The extension 19C may be provided at the tip of the side wall portion that forms the groove shape of the rear channel member 19A.

[0060] The left end of the front channel member 19B is joined to the main body portion 17C of the left side-member lower portion 17B. The right end of the front channel member 19B is disposed to the left of the center of the rear channel member 19A in the left-right direction. A protrusion 19D such as a bead may be provided at the bottom of the rear channel member 19A and the front channel member 19B to enhance rigidity. The protrusion 19D may bulge toward the front channel member 19B and abut against the front channel member 19B. The protrusion 19D may extend laterally along the rear channel member 19A.

[0061] As shown in Figures 1 and 4, the first cross member 21 and the second cross member 22 are formed from rod-shaped members with circular cross sections. The first cross member 21 extends laterally below the upper member 18 and above the lower member 19. Left and right ends 21A of the first cross member 21 are bent upward relative to their centers and welded to the corresponding upper side member portions 17A. The second cross member 22 extends laterally below the first cross member 21 and above the lower member 19. Left and right ends of the second cross member 22 are bent upward relative to their centers and welded to the corresponding upper side member portions 17A.

[0062] The third cross member 23 extends laterally below the second cross member 22 and above the lower member 19, and is welded to the left and right side member lower portions 17B. The third cross member 23 may be formed from multiple sheet metal members. The third cross member 23 has a main body portion 23A whose surfaces face forward and backward, and a bent portion 23B that extends forward and upward from the lower edge of the main body portion 23A and then bends further downward. An anchor 23C that protrudes forward is provided on the lower edge of the third cross member 23. The anchor 23C is used to engage a child seat hook.

[0063] The plate member 24 has its surface facing forward and backward and is welded to the left and right back side members 17, upper member 18, lower member 19, and 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 laterally outward of the left and right back side members 17 and extend up and down. 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 semicircular cross section that convex forward and extends along each edge. Each curved portion 24A may be provided with a concave-convex structure such as a plurality of beads. Each concave-convex structure may extend in a direction perpendicular to the extension direction of the curved portion 24A. Each curved portion 24A and each concave-convex structure improve the rigidity of the plate-shaped portion.

[0064] The plate member 24 has a flat portion 24B whose surface faces forward and backward, and a plurality of raised portions 24C raised from the flat portion 24B. The raised portions 24C may be raised forward or backward from the flat portion 24B. Each raised portion 24C is formed by pushing the plate-shaped portion forward or backward. The raised portions 24C improve the rigidity of the plate member 24.

[0065] As shown in Figures 4 and 6, at least one through hole 19E penetrating from the front to the rear is formed in the rear channel member 19A and the front channel member 19B of the lower member 19. The through hole 19E in the front channel member 19B is positioned so as to overlap the through hole 19E in the rear channel member 19A in the front to rear direction. The plate member 24 is provided with a mark for aligning it with the lower member 19. The mark may be a hole, a protrusion, a recess, a pattern, or the like. When the plate member 24 is positioned appropriately relative to the lower member 19, the mark is exposed forward through the through hole 19E.

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

[0067] The external shape of the electronic control device 42 is preferably formed in a shape that does not cause discomfort to the back of the seated occupant. For example, the external shape of the left part 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 external shape of the left part of the electronic control device 42 is preferably formed by a smoothly curved surface. This configuration can reduce the discomfort that the electronic control device 42 provided on the seat back 3 causes to the back of the seated occupant.

[0068] 1 and 4, the left and right side-member lower portions 17B are rotatably supported on the corresponding left and right base pillars 12 via locking devices 5. The rotation axes of the left and right side-member lower portions 17B extend laterally and are arranged coaxially with each other. The locking devices 5 are arranged coaxially with the rotation axes of the side-member lower portions 17B.

[0069] As shown in FIG. 8 , the locking device 5 has an operating shaft 5A that extends along the rotation axis of the back side member 17, penetrates the back side member 17, and protrudes inward to the left and right of the back side member 17. Rotation of the operating shaft 5A allows or restricts rotation of the back side member 17 relative to the floor 4. A known reclining mechanism can be applied to the locking device 5. The locking device 5 may include, for example, a first portion connected to the base pillar 12, a second portion connected to the side member lower portion 17B and rotatably supported on the first portion, a locking pawl provided on the second portion and movable between an engaged position connected to the first portion and an unlocked position spaced apart from the first portion, a spring that biases the locking pawl to the engaged position, the operating shaft 5A that is arranged coaxially with the rotation axis of the second member relative to the first portion and rotatable relative to the second member, and a cam that is connected to the operating shaft 5A and rotates to move the locking pawl to the unlocked position against the biasing force of the spring. When no external operating force is applied to the operating shaft 5A, the operating shaft 5A returns to its initial position due to the biasing force of the spring. When the operating shaft 5A rotates relative to the back side member 17, the seat back 3 becomes rotatable relative to the floor 4. An operating lever 5B extending radially is provided at the end of each operating 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 an upholstery material. The seat cushion frame 31 has 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 in the front-to-rear direction and are spaced apart from each other on the left and right. The front member 33 extends in the left and right directions and is connected to the front ends of the left and right cushion side members 32. The rear member 34 extends in the left and right directions and is connected to the rear ends of the left and right back side members 17. The center plate 35 extends in the front-to-rear direction and is connected to the front member 33 and the rear member 34.

[0071] Left and right rear links 37 extending rearward and upward are connected to the rear ends of the left and right cushion side members 32. 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 supported by the left and right side member lower parts 17B so as to be rotatable about axes extending laterally. This allows the seat cushion 2 to be rotatably connected to the seat back 3.

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

[0073] 1, the seatback frame 16 is provided with a first drive device 41 that drives the locking device 5 and an electronic control device 42 that controls the first drive device 41. The electronic control device 42 is composed of a CPU, non-volatile memory (ROM), volatile memory (RAM), etc. The first drive device 41 and the electronic control device 42 are arranged vertically side by side on one side of the seatback frame 16 in the left-right direction. In this embodiment, the first drive device 41 and the electronic control device 42 are arranged vertically side by side on the right side of the seatback 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 with 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 perpendicular 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 positioned offset forward from the first portion 44A and abutting 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 with fastening members such as bolts and nuts. The first portion 44A may be coupled to the back side member 17 in addition to the flat portion 24B.

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

[0076] The external shape of the electronic control device 42 is preferably formed in a shape that does not cause discomfort to the back of the seated occupant. For example, the external shape of the left part 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 external shape of the left part of the electronic control device 42 is preferably formed by a smoothly curved surface. This configuration can reduce the discomfort that the electronic control device 42 provided on the seat back 3 causes to the back of the seated occupant.

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

[0078] The first protrusions 46B are curved in a semicircular shape and extend along the outer periphery of the side-member upper portion 17A. In this embodiment, two first protrusions 46B are arranged vertically spaced apart. The upper first protrusion 46B is arranged lower than the end of the first cross member 21. The end of the first cross member 21 is bent toward the side opposite the second bracket 46. The two first protrusions 46B may be welded to or fastened to the side-member upper portion 17A. The second protrusion 46C may be welded to or fastened to the plate member 24.

[0079] The second protrusion 46C and the first drive device 41 are disposed below the electronic control device 42. The second protrusion 46C and the first drive device 41 are also disposed below the first cross member 21. In other words, the first cross member 21 passes between the first drive device 41 and the electronic control device 42 and extends to the left and right.

[0080] As shown in FIG. 4, a relay lever 51 is rotatably provided on the left side of the plate member 24, 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 operating lever 5B of the left locking device 5 via a second control cable 53 (transmission member), and is connected to the operating lever 5B of the right locking device 5 via a third control cable 54 (transmission member).

[0081] A protrusion 5C protruding radially from the rotation axis of the right operating lever 5B is provided at the base end of the right operating lever 5B. A sensor 57 that detects the position of the operating lever 5B is provided at the lower end of the back side member 17. The sensor 57 is disposed around the operating lever 5B on the right side surface of the right side member lower part 17B. The sensor 57 may be a limit switch that rotates when pressed by the protrusion 5C of the operating lever 5B. When the seat back 3 is in the seating 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 operating lever 5B is connected to the side member lower part 17B via a spring 5D and is biased toward the initial position.

[0082] 4 and 5, the base 7 is provided with a second drive device 61 that rotates the seat back frame 16 relative to the base 7. The second drive device 61 connects the base 7 and the seat back 3 and rotates the seat back 3 relative to the base 7 by extending and contracting. The second drive device 61 has a case 61A, a ball screw nut 61B rotatably supported on the case 61A, a ball screw shaft 61C threadedly engaged with the ball screw nut 61B, and an electric motor 61D coupled to the case 61A and rotating the ball screw nut 61B. The case 61A is connected to the base cross member 13 via a hinge 63 so as to be rotatable about an axis extending laterally. 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 connected to the lower hinge bracket 63A about an axis extending laterally and fastened to the case 61A. A through-hole, or work hole 13C, is formed in the bottom of the lower channel member 13A of the base cross member 13. A bolt 13D fastening the upper channel member 13B and the lower hinge bracket 63A is exposed downward through the work hole 13C. This allows a worker to fasten 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 seatback 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 coupled to the bracket 64 so as to be rotatable about an axis extending in the left-right direction. 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 coupled to a connecting portion 19F formed integrally with the rear channel member 19A so as to be rotatable about an axis extending in the left-right direction. The connecting portion 19F may be formed, for example, by cutting and raising the rear channel member 19A.

[0084] As shown in Figures 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-to-rear direction. The axis of the ball screw shaft 61C is perpendicular to the rotation axis of the electric motor 61D in a plan view. With this configuration, the front end of the second drive device 61 is disposed rearward of the front member 33 of the seat cushion 2, thereby preventing the legs of a seated occupant from coming into contact with the electric motor 61D.

[0085] The electric motor 61D is disposed rearward of the base cross member 13. The rotation shaft of the electric motor 61D extends in the left-right direction and generally 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. This configuration shortens the distance between the electric motor 61D and the seat back 3, and the ball screw shaft 61C can be shortened. This allows the drive unit 61 to be made more compact.

[0086] The upper wall portion of the electric motor 61D may be located higher than the upper part of the right part 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 part of the right part of the base cross member 13. The upper wall portion of the electric motor 61D may be located lower than the upper part of the right part of the base cross member 13. This configuration allows the electric motor 61D and the base cross member 13 to be arranged compactly.

[0087] 4 and 9, the electronic control device 42 is connected to the first drive device 41 by a first harness 66, to the second drive device 61 by a second harness 67, and to the sensor 57 by a third harness 68. The first to third harnesses 66 to 68 are partially bundled together. A portion of the second harness 67 is fastened to the lower member 19 by a plurality of resin fasteners 69 and is disposed along the lower member 19. In another embodiment, a portion of the second harness 67 may be fastened to the third cross member 23 by a plurality of resin fasteners 69 and is disposed along the third cross member 23.

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

[0089] Next, the operation of the seat 1 will be described. As shown in FIG. 10(A), when the seat 1 is in the in-use position, the seat back 3 stands upright relative 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 disposed at a distance from the floor 4. When the seat 1 is in the in-use position, if an occupant performs a first operation on the operation switch 72, 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. As a result, the first drive device 41 moves the relay lever 51 from the initial position to the drive position via 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 lock position to the release position. As a result, the left and right locking devices 5 are released, and the seat back 3 becomes rotatable relative to the base 7.

[0090] When the right operating lever 5B reaches the release position, the sensor 57 is pressed by the protrusion 5C of the operating lever 5B, outputting 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 operating lever 5B has reached the release position, i.e., that the locking device 5 has been released. Upon determining that the locking device 5 has been released, the electronic control unit 42 controls the drive of the electric motor 61D of the second drive unit 61 to extend the second drive unit 61. As the electric motor 61D rotates, the ball screw nut 61B rotates relative to the case 61A, causing the ball screw shaft 61C to protrude rearward relative to the case 61A. As a result, as shown in FIG. 10(B), the second drive unit 61 pushes the lower end of the seat back 3 rearward, causing the upper portion of the seat back 3 to rotate forward. At the same time, the seat cushion 2 is pushed forward and downward by the seat back 3, causing the seat 1 to assume the stowed position. The electronic control device 42 detects that the ball screw shaft 61C has reached its longest position based on the drive current of the electric motor 61D of the second drive device 61, and stops driving the second drive device 61. The electronic control device 42 also measures the elapsed time from when it determined that the lock device 5 was released, and stops driving the first drive device 41 when the elapsed time reaches a predetermined time. As a result, the lock device 5 changes from the released state to the locked state due to the biasing force of the springs of the left and right lock devices 5. As a result, the seat 1 is maintained in the stowed position, as shown in FIG. 10(C).

[0091] When the occupant performs a second operation on the operation switch 72 while the seat 1 is in the stowed position, a second signal is output to the electronic control unit 42. The electronic control unit 42 drives and controls the first drive unit 41 based on the second signal. As a result, the first drive unit 41 moves the left and right operation levers 5B from the locked position to the unlocked 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 unlocked, and the seat back 3 becomes rotatable relative to the base 7.

[0092] Based on the signal from the sensor 57, the electronic control unit 42 determines that the operating lever 5B has reached the release position, i.e., that the locking device 5 has been released. When the electronic control unit 42 determines that the locking device 5 has been released, it controls the drive of the electric motor 61D of the second drive unit 61 to retract the second drive unit 61. When the electric motor 61D rotates, the ball screw nut 61B rotates relative to the case 61A, and the ball screw shaft 61C moves forward relative 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 unit 61, and the upper part of the seat back 3 rotates rearward. At the same time, the seat cushion 2 is pulled by the seat back 3 and moves rearward and upward. This puts the seat 1 into the usage configuration. Based on the drive current of the electric motor 61D of the second drive unit 61, the electronic control unit 42 detects that the ball screw shaft 61C has reached the shortest position and stops driving the second drive unit 61. The electronic control device 42 also measures the elapsed time from when it is determined that the locking device 5 is released, and stops driving the first driving device 41 when the elapsed time reaches a predetermined time. As a result, the locking device 5 changes from the released state to the locked state due to the biasing force of the springs of the left and right locking devices 5. As a result, the seat 1 is maintained in the usage configuration as shown in FIG. 10(A).

[0093] According to the seat 1 according to this embodiment, the electronic control device 42 can be disposed in a position that does not interfere with the operation of the seat 1. By disposing the electronic control device 42 in the seat back 3, the thickness of the seat cushion 2 can be reduced. Also, a space can be secured below the seat cushion 2 for the seat cushion 2 to move. Also, the impact that the electronic control device 42 and the first drive device 41 have on the back of the occupant can be reduced.

[0094] The first bracket 44 that supports the electronic control device 42 is disposed so as to overlap the flat portion 24B and the raised portion 24C of the plate member 24. This allows the first bracket 44 to be disposed in a highly rigid portion of 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 unit 42 is disposed in a corner defined by the upper member 18 and the back side member 17. The electronic control unit 42 is also disposed in a space defined by the upper member 18, the back side member 17, the first cross member 21, and the headrest pillar. Therefore, the electronic control unit 42 can be disposed by effectively utilizing the space formed by the upper member 18, the back side member 17, and the plate member 24. Furthermore, the impact of the electronic control unit 42 on the back of the occupant can be reduced.

[0096] Because 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 in a space-efficient manner in the seat back 3. Furthermore, because 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. Because the end of the first cross member 21 connected to the back side member 17 is bent upward, interference with the second bracket 46 connected to the back side member 17 can be avoided.

[0097] The seat 200 according to the second embodiment differs from the seat 1 according to the first embodiment in the structure around the second drive device 61. In the following explanation, only the different configuration will be explained, and the explanation of the same configuration as the seat 1 according to the first embodiment will be omitted by citing the above description.

[0098] As shown in Figures 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 joined to the corresponding vertical wall portions 11B of the base side members 11. The base cross member 213 is divided by the multiple 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 positioned 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 206A with its surfaces facing up and down and left and right sidewalls 206B extending downward from the left and right edges of the main body 206A. A semicircular recess 206C is formed at the lower end of the sidewall 206B. The upper portion of the base cross member 213 is received in the recess 206C and welded thereto. A lower hinge bracket 63A is fastened to the main body 206A of the bracket 206. This configuration simplifies the configuration of the base cross member 213 and improves its rigidity. Furthermore, the second drive unit 61 can be fixed to the curved base cross member 213 via the bracket 206.

[0100] The lower member 219 of the seatback frame 16 is formed of a channel member with a groove-shaped cross section that opens forward. The lower member 219 has a side wall portion 219A whose surface faces forward and backward, an upper wall portion 219B that extends forward from the upper edge of the side wall portion 219A, and a lower wall portion 219C that extends forward from the lower edge of the side wall portion 219A. The vertical width of the side wall portion 219A is wider than the vertical width of the upper wall portion 219B, and the vertical width of the side wall portion 219A is wider than the vertical width of the lower wall portion 219C. The left and right ends of the side wall portion 219A of the lower member 219 are welded to the inside of the edge wall portions 17D of the corresponding left and right side-member lower portions 17B. With this configuration, the lower member 219 is joined to the back side member 17 at the side wall portion 219A, which is wider than the upper wall portion 219B and the lower wall portion 219C, and therefore the rigidity of the joint 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 207A whose surfaces face forward and backward, and left and right edge wall portions 207B extending forward from left and right side edges of the rear wall 207A. The rear wall 207A and the left and right edge wall portions 207B are formed by bending a metal plate. An upper end portion 207C of the rear wall 207A extends upward beyond the upper ends 207C of the left and right edge wall portions 207B and is in surface contact with the rear surfaces of the side wall portions 219A of the lower member 219. The upper end portion 207C of the rear wall 207A is welded to the rear surfaces of the side wall portions 219A of the lower member 219. The upper ends of the left and right edge wall portions 207B abut and are welded to the lower surfaces of the lower wall portions 219C of the lower member 219. The edge wall portion 207B of the bracket 207 extends downward and forward. The left and right edge wall portions 207B have surfaces facing left and right and are spaced apart in the left-right direction. The left and right edge wall portions 207B are bent at their vertically intermediate portions so that the distance between their respective lower ends 207D is smaller than the distance between their respective upper ends 207C. The lower ends 207D of the left and right edge wall portions 207B are formed with support holes 207E penetrating from left to right. A shaft 208 is inserted into the support hole 207E. The rear end 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. Because the bracket 207 extends downward and forward, the bracket 207 can compactly accommodate the ball screw shaft 61C below the seat back 3 when the seat 200 is in the stowed configuration.

[0102] As shown in FIG. 16, a luggage compartment 201 is provided behind a seat 200 in an automobile. A floor 4 defining the lower part of the luggage compartment 201 is provided with a recess 220 that is recessed downward. The recess 220 can store items 221 such as tires. 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 on the floor 4 and extends horizontally. The luggage compartment board 202 is made of, for example, resin.

[0103] A cover 203 is provided on 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 stowed position, the front end of the cover 203 is positioned on the back surface of the seat back 3. That is, the cover 203 is provided so as to cover the gap between the luggage compartment board 202 and the seat back 3. The cover 203 may be molded integrally with the luggage compartment board 202. When the seat 200 is in the stowed position, the cover 203 is positioned above the rear end of the ball screw shaft 61C. When the seat 200 is in the usage position, the bracket 207 extends forward and downward. Therefore, when the seat 200 is in the stowed position, the bracket 207 and the rear end of the ball screw shaft 61C can be prevented from contacting the cover 203. With this configuration, when the seat 200 is in the stowed position, 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. More specifically, the sensor 204 is disposed between the upper surface of a pad constituting the seat cushion 2 and the covering material. The sensor 204 is a load sensor that detects a load. The sensor 204 may be, for example, a piezoelectric element or a membrane switch that deforms in response to the load and connects contacts. The sensor 204 is provided to detect whether or not an object is present on the seat cushion 2. In this embodiment, the sensor 204 is a membrane switch that outputs an ON signal when a load equal to or greater than a predetermined value is applied.

[0105] The sensor 204 is connected to the electronic control device 42. The sensor 204 outputs a signal to the electronic control device 42 in response to the detected pressure. When the electronic control device 42 determines that an object is present on the seat cushion 2 based on the signal from the sensor 204, the electronic control device 42 restricts the transformation from the use configuration to the storage configuration. In detail, when the electronic control device 42 receives an ON signal from the sensor 204, it prohibits the driving of the first drive device 41. With this configuration, it is possible to prevent the seat 200 from transforming into the storage configuration 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 be used to detect whether an object is caught between the seat cushion 2 and the seat back 3. For example, as shown in FIG. 17 , the sensor may be a strain sensor 222 provided between the upper hinge bracket 63B and the case 61A. The strain sensor 222 is a known strain sensor that outputs a signal corresponding to strain to the electronic control device 42. When an object is caught between the seat cushion 2 and the seat back 3, the seat back 3 is restricted from moving relative to the seat cushion 2. At this time, the ball screw shaft 61C attempts to move rearward relative to the case 61A, and the strain sensor 222 is compressed between the upper hinge bracket 63B and the case 61A. This allows the electronic control device 42 to detect whether an object is caught between 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, simplifying the structure of the seat cushion 2. In another embodiment, the electronic control device 42 may detect that an object is caught between the seat cushion 2 and the seat back 3 based on the current flowing through the electric motor 61D.

[0107] The seat 200 is provided with an indicator 205. The indicator 205 is a display device including, for example, an LED. The indicator 205 may be disposed at the upper end of the left side of the seat back 3. The indicator 205 is connected to the electronic control unit 42. The electronic control unit 42 turns on the indicator 205 when the ball screw shaft 61C is in the longest position and the operating lever 5B is in the initial position. This configuration allows the user to visually confirm that the seat 200 has completely changed to the stowed configuration. In another embodiment, the electronic control unit 42 may turn on the indicator 205 when the operating 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 seat 1, 200 preferably includes the steps of rotatably mounting the seat back 3 on the base 7, rotatably mounting the seat cushion 2 on the seat back 3, and connecting the drive device 61 that rotates the seat back 3 relative to the base 7 to the base 7 and the seat back 3 and mounting the drive device 61 behind the front end of the seat cushion 2. According to this embodiment, the vehicle seat 1, 200 including the second drive device 61 can be unitized. This makes it easy to mount the vehicle seat 1, 200 on a vehicle.

[0109] The seat 300 according to the third embodiment differs from the seats 1 and 200 according to the first and second embodiments in the internal structure of the seat cushion 2. In the following explanation, only the different configurations will be explained, and the explanation of the same configurations as those of the seat 1 according to the first embodiment will be omitted by citing the above description.

[0110] As shown in Figures 18 and 19, the seat 300 has a sheet-like member 301 instead of the center plate 35. The sheet-like member 301 extends in the front-rear direction and is suspended between the front member 33 and the rear member 34. The sheet-like member 301 has surfaces facing up and down, and its front edge 301A and rear edge 301B extend left and right. The sheet-like member 301 is flexible and may be made of, for example, woven fabric. The sheet-like member 301 may be made of, for example, PET resin or the like.

[0111] A reinforcing thread 302 may be sewn to the sheet-like member 301. The reinforcing thread 302 improves the tensile strength of the sheet-like member 301. The reinforcing thread 302 may have, for example, left and right side portions 302A extending in the front-to-rear direction, 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 may be formed in a straight line, and the reinforcing thread 302 may be arranged in an N-shape.

[0112] As shown in Figures 20 and 21, the sheet-like member 301 has a plurality of cylindrical front holding holes 303A extending laterally at its front edge. The front holding holes 303A are preferably formed by folding back the front edge 301A of the sheet-like member 301 and sewing the front holding holes 303A to the main body of the sheet-like member 301. A gap is formed between adjacent front holding holes 303A. A front shaft 304A extending laterally is inserted into each front holding hole 303A. The front shaft 304A has bent portions 305A bent forward at both left and right ends. The bent portions 305A determine the left and right positions of the front shafts 304A relative to the respective front holding holes 303A.

[0113] The sheet-like member 301 has a plurality of cylindrical rear holding holes 303B extending laterally at its rear edge. The rear holding holes 303B may be formed by folding back the rear edge 301B of the sheet-like member 301 and sewing the holes to the main body of the sheet-like member 301. A gap is formed between adjacent rear holding holes 303B. A rear shaft 304B extending laterally is inserted into each rear holding hole 303B. The rear 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 shafts 304B relative to the respective rear holding holes 303B.

[0114] The front member 33 has a plurality of front locking portions 306A. The plurality of front locking portions 306A are arranged side by side on the left and right. Each front locking portion 306A is preferably a protrusion extending forward and downward from the front member 33. Each front locking portion 306A is preferably formed by cutting the front member 33 downward. The rear member 34 has a plurality of rear locking portions 306B. The plurality of rear locking portions 306B are arranged side by side on the left and right. Each rear locking portion 306B is preferably a protrusion extending rearward and downward from the rear member 34. Each rear locking portion 306B is preferably formed by cutting the rear member 34 downward.

[0115] The front shaft 304A is exposed to the outside between the front holding holes 303A and is locked by the plurality of front locking portions 306A. Similarly, the rear shaft 304B is exposed to the outside between the rear holding holes 303B and is locked by the plurality of front locking portions 306A. With the sheet-like member 301 stretched in the front-rear direction by elastic deformation, the front shaft 304A may be locked by the plurality of front locking portions 306A, and the rear shaft 304B may be locked by the plurality of rear locking portions 306B.

[0116] A pad 307 is provided on the upper part of the seat cushion frame 31. The pad 307 is made of a flexible resin material such as urethane foam. The sheet-like member 301 supports the center of the pad 307 from below.

[0117] A sensor 309 is provided on the upper part of the seat cushion 2. More specifically, the sensor 309 is disposed between the upper surface of a pad 307 constituting the seat cushion 2 and a cover 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 in response to the load and connects contacts. The sensor 309 is provided to detect whether or not an occupant is seated on the seat cushion 2. In this embodiment, the sensor 309 is a membrane switch that 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. A 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 positioned so as to overlap when viewed from above. In other words, the first harness hole 311 and the second harness hole 312 are preferably connected to each other. Furthermore, if 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 is preferably formed in 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 extends downward from the second harness hole 312 and extends along the base cross member 13 (213) toward the second drive device 61. One or more portions of the sensor harness 310 are connected to the base cross member 13 (213) by a resin fastener 69 or the like. A portion of the sensor harness 310 is also bundled together with the second harness 67. The sensor harness 310 extends to the lower member 19 (219) together with the second harness 67, and then extends to the electronic control device 42.

[0120] 22 , the seat 300 has a restricting portion 315 that protrudes forward from the seat back 3 when in the use position. The restricting portion 315 restricts the load that the seat back 3 applies to the sensor 309 to be below a predetermined value when the seat 300 is in the stowed position. The restricting portion 315 is made up of a pad 307 and a skin material 308 that covers the pad 307, and is preferably formed integrally with the seat back 3.

[0121] The restricting portions 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 of the front surface of the seat back 3. That is, the portions of the front surface of the seat back 3 where the left and right side support portions 316 are provided protrude forward relative to the center portion of the seat back 3 in the left-right direction. The left and right side support portions 316 extend vertically. When the seat 300 is in the stowed position, the left and right side support portions 316 abut on the left and right side portions of the seat cushion 2, thereby forming a gap between the center portion of the seat back 3 in the left-right direction and the upper surface of the seat cushion 2. This prevents a load from being applied to the sensor 309. This prevents the sensor 309 from making a false detection due to the load from the seat back 3.

[0122] The restricting portion 315 may be, for example, a headrest 317 provided on 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 stowed position, the headrest 317 abuts against the front part 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. This prevents a load from being applied to the sensor 309. This makes it possible to prevent the sensor 309 from making a false detection due to the load from the seat back 3.

[0123] The seat 300 according to the third embodiment has a flexible sheet-like member 301, so that the seat cushion 2 can provide a soft feel to the occupant. The sheet-like member 301 is provided with a second harness hole 312, so that 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. In addition, by attaching a 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 contact with 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 may be manufactured by a manufacturing method including 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 differs from the seat 300 according to the third embodiment in the routing of the sensor harness 310 below the seat cushion 2. In addition, the seat 400 does not have a 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. Then, it passes between the pad 307 and the sheet-like member 301 and reaches 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 in the bottom surface of the pad 307, and the sensor harness 310 is disposed in the harness receiving groove 307A. The sensor harness 310 then passes through the space between the sheet-like member 301 and one of the left and right cushion side members 32 and extends downward. The sensor harness 310 then extends along the base cross member 13 (213) toward the second drive device 61. One or more portions of the sensor harness 310 are connected to the base cross member 13 (213) by a resin fastener 69 or the like. A portion of the sensor harness 310 is also 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 .

[0127] A resin cover 418 extending in the front-rear direction may be attached to the cushion side member 32. The cover 418 is provided on at least 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 down and a hanging portion 418B extending downward from the upper surface portion 418A along the cushion side member 32. The cover 418 has a convex boss (not shown) that protrudes from the back surface of the hanging portion 418B and abuts the inner surface 32A at its tip. The sensor harness 310 may extend downward from a side edge of the sheet-shaped member 301, passing through a space between the cover 418 and the side edge of the sheet-shaped member 301 that faces oppositely in the left-right direction. By passing the sensor harness 310 between the lower surface of the pad 307 and the upper surface of the sheet-shaped member 301, the second harness hole 312 can be omitted from the sheet-shaped member 301. By omitting the second harness hole 312 from the sheet-shaped member 301, it is possible to improve the tensile strength of the sheet-shaped member 301. Furthermore, by providing the cover 418 to the cushion side member 32, it is possible to prevent the sensor harness 310 from coming into contact with the cushion side member 32, thereby suppressing wear of the sensor harness 310.

[0128] The seat 500 according to the fifth embodiment differs from the third embodiment in the structures of the seat cushion frame 31 and the sheet-like member 301. In addition, the seat cushion 2 has a support member 319. In the following explanation, only the different configurations will be explained, and the explanation of the same configurations as those of the seat 300 according to the third embodiment will be omitted by citing the above description.

[0129] As shown in Figure 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 joined to the left and right side members 32. The middle member 520 may be formed, for example, from a pipe material with a circular cross section. The rear member 521 may also be formed from a pipe material with a circular cross section.

[0130] As shown in FIGS. 24 to 26 , the seat 500 has a support member 522. The support member 522 extends in the front-to-rear direction and is suspended between a middle member 520 and a rear member 521. The support member 522 has surfaces facing up and down, and its front and rear edges extend left and right. The support member 522 is flexible and is formed, for example, from resin. The support member has, in order from the front side, a front portion 522A, an intermediate portion 522B, and a rear portion 522C. The support member 522 is supported at the front portion 522A by the middle member 520 and at the rear portion 522C by the rear member 521. The intermediate portion 522B extends substantially horizontally, the front portion 522A extends forward and upward from the intermediate portion 522B toward the front member 33, and the rear portion 522C extends rearward and upward from the intermediate portion 522B toward the rear member 521. The left-right width of the middle portion 522B is preferably set smaller than the left-right widths of the front portion 522A and the rear portion 522C. In this embodiment, the middle portion 522B is formed in a triangular shape, with the left-right width narrowing toward the front. The front portion 522A and the rear portion 522C are each formed in a substantially rectangular shape. The left-right width of the front portion 522A is formed smaller than the left-right width of the rear portion 522C. At least one lightening hole 523 is preferably 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 lightening hole 523 can be set as desired.

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

[0132] A front edge of the front part 522A of the support member 522 is provided with a plurality of first hook portions 524 that hook onto the middle member 520. Each of the first hook portions 524 is formed in a semicircular shape that opens downward when viewed from the left and right. A rear edge of the rear part 522C of the support member 522 is provided with a second hook portion 525 that hook onto the rear member 521. The second hook portion 525 extends left and right along the rear edge of the rear part 522C of the support member 522. The second hook portion 525 is formed in a semicircular shape that opens downward when viewed from the left and right. The plurality of first hook portions 524 are hooked onto the middle member 520, and the second hook portion 525 is hooked onto the rear member 521, so that the support member 522 is hung between the middle member 520 and the rear member 521.

[0133] Furthermore, a sheet-like member 301 is spanned between the middle member 520 and the rear member 521. At least one front engaging portion 526A is provided on the front edge 301A of the sheet-like member 301. The front engaging portion 526A is formed by bending a metal rod. The front edge 301A of the sheet-like member 301 is folded back and sewn to form multiple front loop portions 527A. Each front loop portion 527A extends left and right. The front engaging 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 portions 529 are formed in a semicircular shape that is open downward when viewed from the left and right direction.

[0134] At least one rear locking portion 526B is provided on the rear edge 301B of the sheet-shaped member 301. The rear locking portion 526B is formed by bending a metal rod. The rear edge 301B of the sheet-shaped member 301 is folded back and sewn to form multiple rear loop portions 527B. Each rear loop portion 527B extends left and right. The rear locking portion 526B has a shaft portion 531 rotatably supported on 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 semicircular shape that is open downward when viewed from the left and 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. A front engagement groove 524A that receives the third hook portion 529 is formed on the upper surface of the first hook portion 524 of the support member 522. The front engagement groove 524A extends in the front-to-rear direction along the upper surface of the first hook portion 524. The position of the front locking portion 526A in the left-to-right direction relative to the first hook portion 524 is determined by fitting each third hook portion 529 into the corresponding front engagement groove 524A.

[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. A rear engagement groove 525A that receives the fourth hook portion 530 is formed on the upper surface of the second hook portion 525 of the support member 522. The rear engagement groove 525A extends in the front-to-rear direction along the upper surface of the second hook portion 525. The position of the rear locking portion 526B in the left-to-right direction relative to the second hook portion 525 is determined by fitting each fourth hook portion 530 into the corresponding rear engagement groove 525A.

[0137] When no load is applied to the upper surface of the seat cushion 2, the central portion 301C of the sheet-shaped member 301 in the front-rear direction is located at a position away 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-shaped member 301 bends downward and is supported by the upper surface of the support member 522.

[0138] When viewed from the top-bottom direction, it is preferable that the lightening hole 523 of the support member 522 is disposed at a position overlapping the second harness hole 312 of the sheet-like member 301. This allows the sensor harness 310, which has passed downward through the second harness hole 312, to extend downward through the support member 522 through the lightening hole 523. In other words, the lightening hole 523 functions as a harness hole for passing the sensor harness 510.

[0139] The support member 522 supports the sheet-like member 301, thereby increasing the load that can be supported by the seat cushion 2. The support member 522 is provided with a lightening hole 523, which makes it easy to arrange the sensor harness 310.

[0140] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and can be widely modified and implemented. [Explanation of symbols]

[0141] 1: Sheet 2: Seat cushion 3: Seat back 4: Floor 5: Locking device 5A: Operation axis 5B: Control lever 5C: Convex part 7: Bass 16: Seat back frame 17: Backside member 18: Upper Member 19: Lower Member 21: First cross member 21A: End 24: Plate member 24B: Flat part 24C: Ridge 26: Headrest support part 37: Next link 41: First drive unit 41A: First electric motor 42: Electronic control device 44: First bracket 46: Second bracket 57: Sensor 61: Second drive unit 67: Second harness 202: Cargo board 203: Cover 204: Sensor 205: Indicator 206: Bracket 207: Bracket 213: Base cross member 214: Bend 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: 3rd harness hole 314: Grommet 315: Regulation Department 316: Side support part 317: Headrest 418: Cover 522: Support member

Claims

[Claim 1] 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 cover material covering the pad, the seat cushion frame includes left and right side members extending in the front-rear direction, a front member extending in the left and right direction and joined to front portions of the left and right side members, and a rear member extending in the left and right direction and joined to rear portions of the left and right side members, A flexible sheet-like member is bridged between the front member and the rear member, the sheet-like member extending in the front-rear direction and having a surface facing up and down, At least a portion of the pad is supported from below by the sheet-like member, The pad is provided with an occupant detection sensor, the occupant detection sensor is provided on an upper surface of the pad, A vehicle seat in which a harness connected to the occupant detection sensor passes through a first hole that penetrates the pad vertically and also passes through a gap between the seat-like member and the side member, extending from the occupant detection sensor below the seat-like member.

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