JP7568893B2 - Vehicle seats - Google Patents

Description

The present invention relates to a vehicle seat equipped with a seat back frame having left and right side frames with a plate-like portion that spreads around the rotation axis along a vertical plane perpendicular to the rotation axis and extends upward along the vertical plane, and a rear wall that is continuous with the rear edge of the plate-like portion and is bent inward to form a curved area that extends vertically around the rotation axis, a lower frame that is disposed behind the rotation axis and joined to the rear wall from behind, and has a back region that connects the left and right side frames to each other, and an upper frame that connects the left and right side frames to each other above the lower frame.

Patent Document 1 discloses a vehicle seat (vehicle seat) equipped with a seat back that is connected to a seat cushion so that it can be freely reclined. The seat back extends vertically upward from a rotation axis and has left and right side frames that support a seat back pad, a lower panel (lower frame) that is positioned behind the axis of rotation for reclining and connects the left and right side frames to each other, and an upper cross member (upper frame) that connects the left and right side frames to each other above the lower panel. The left and right side frames, the lower panel, and the upper cross member form a square frame structure.

JP 2013-67240 A

Each side frame has a plate-like portion extending along a vertical plane perpendicular to the axis of rotation of the reclining mechanism, and a rear wall that is continuous with the rear edge of the plate-like portion and bent inward to form a curved region that extends vertically around the axis of rotation and reaches the upper cross member. When assembling the seatback frame, the lower panel is joined to the rear wall of the side frame from the rear. Therefore, the side frame can be assembled to the lower panel from one direction. The side frame can be assembled to the lower panel with good work efficiency.

On the other hand, because the area between the two joint areas is flat, the torsional rigidity of the frame structure is not very high. To ensure torsional rigidity, high joint strength is required for the joints between the lower panel and the side frame. This increases the workload of the joints.

The present invention aims to provide a vehicle seat that can help reduce the workload involved in assembling the seat back frame.

According to the first aspect of the present invention, the plate-shaped portion 35a extends along a vertical plane perpendicular to the rotation axis SX around the rotation axis and extends upward along the vertical plane. In a vehicle seat 11 including a seat back frame 25 having left and right side frames 35 having a front wall 35b extending inwardly from a front edge of the plate-shaped portion 35a and a rear wall 35c extending inwardly from a rear edge of the plate-shaped portion 35a, a lower frame 36 having a back region 51 connecting the left and right side frames 35 to each other, and an upper frame 37 connecting the left and right side frames 35 to each other above the lower frame 36 , the back region 51 is joined to a rear surface of the rear wall 35c in the seat fore-and-aft direction , the lower frame 36 has a reinforcing region 52 that is continuous from a lower edge of the back region 51, extends forward beyond the rotation axis SX, and is joined to a rear surface of the front wall 35b in the seat fore-and-aft direction , and in a front view, the rear wall 35c is positioned so as to avoid a position overlapping with a front end of the reinforcing region 52 but at a position overlapping with the back region 51.

According to the second side, in addition to the configuration of the first side, a weld mark 63 is formed at the point where the front wall 35b and the reinforcement area 52 are joined, and the weld mark 63 is in a position that does not overlap with the rear wall 35c when viewed from the front.

According to the third side, in addition to the configuration of the second side, a weld mark 54 is formed at the point where the rear wall 35c and the back region 51 are joined, and the weld mark 54 is in a position that does not overlap with the front wall 35b when viewed from the front.

According to the fourth side, in addition to the configurations of the first to third sides, the upper edge of the back region 51 has a first edge 53a extending parallel to the rotation axis SX in the left-right direction from the left-right center position, and a second edge 53b extending while curving upward from the left and right ends of the first edge 53a, respectively.

According to the fifth side, in addition to the configuration of the fourth side, the upper edge of the spine region 51 includes a third edge 53c that extends outwardly from the upper end of the second edge 53b parallel to the rotation axis SX and is overlapped on the side frame 35.

According to the sixth side, in addition to the configurations of the fourth and fifth sides, the rear wall 35c has a high wall portion 61b extending from the plate-shaped portion 35a to the second edge 53b in the direction of the rotation axis SX, and a low wall portion 61a arranged below the high wall portion 61b and extending from the plate-shaped portion 35a shorter than the high wall portion 61b in the direction of the rotation axis SX, the low wall portion 61a being formed at a position outer than the left and right ends of the front end of the reinforcement area 52, and the front end of the reinforcement area 52 being arranged below the high wall portion 61b.

According to the seventh side, in addition to the configuration of the sixth side, the first edge 53a and the second edge 53b are provided with a flange 51b extending forward, the flange 51b being continuous with the first edge 53a and the second edge 53b and extending to the upper end of the second edge 53b.

According to the eighth side, in addition to the configuration of the seventh side, a side frame flange 41 is formed on the rear wall 35c, extending forward from the inner end of the rear wall 35c, the side frame flange 41 extends in the up-down direction of the seat, and the lower end of the side frame flange 41 is formed at the lower end of the high wall portion 61b on the inner side in the seat width direction.

According to the ninth aspect, in addition to the configuration of the eighth aspect, the flange 51b is disposed more inwardly than the side frame flange 41 in the seat width direction.

According to the tenth side, in addition to the configuration of the sixth side, an overlapping piece 62 is formed on the front wall 35b of the side frame 35, extending inward from the inner edge of the front wall 35b and overlapping the lower frame 36, and the overlapping piece 62 extends shorter than the high wall portion 61b and longer than the low wall portion 61a in the direction of the rotation axis SX.

According to the first aspect, the lower frame is joined to each side frame not only in the back region, but also in a reinforcement region that extends from the lower edge of the back region toward the front of the rotation axis, so that the torsional rigidity of the seatback frame can be increased. Compared to when the lower frame is joined to the side frame only in the back region, the joining strength of the lower frame and the side frame can be reduced. In this way, the joining work load can be reduced. Moreover, when assembling the seatback frame, the lower frame can be attached to the side frame from the rear. The side frame can be attached to the lower frame from one direction. Workability of assembly is not impaired.

1 is a perspective view showing a schematic overall configuration of a vehicle seat according to a first embodiment of the present invention; FIG. 2 is a perspective view showing a schematic structure of a seat frame. FIG. 2 is a perspective view showing a schematic configuration of a seat cushion pad and a seat back pad. FIG. FIG. FIG. 6 is an enlarged cross-sectional view taken along line 6-6 in FIG. 4. FIG. 4 is an enlarged partial bottom view of the seat back frame. FIG. FIG. 4 is an enlarged partial front view of the side frame. 10 is a cross-sectional view taken along line 10-10 in FIG. 8. FIG. 4 is an enlarged perspective view of an upper wall of the upper frame. 4 is a cross-sectional view of the lower frame taken along a cutting plane passing through the central axis of the insertion hole. FIG. 1 is a cross-sectional view of a side frame overlapped on a lower frame and cut along a cutting plane passing through the central axis of an insertion hole. FIG. 1 is a cross-sectional view of an upper frame overlapped on a side frame and cut along a cutting plane passing through the central axis of an insertion hole. FIG. 4 is a cross-sectional view of the lower frame and the connecting shaft taken along a cutting plane passing through the central axis of the opening. FIG. FIG. 11 is a front view of an upper frame according to a modified example. 13 is a cross-sectional view of the lower frame and the connecting shaft taken along a cutting plane passing through the central axis of the opening, showing a connecting shaft according to another specific example. FIG. 11 is a front view showing a schematic view of a support tube inserted into the upper wall and the lower wall of the upper frame. FIG. 19 is a cross-sectional view taken along line 19-19 in FIG. 18.

Embodiments of the present invention will be described below with reference to the attached drawings. In the following description, front/rear, left/right, and up/down refer to directions as seen by an occupant seated in a vehicle seat in a normal seating position (basic position when driving).

1 shows a schematic diagram of the overall structure of a vehicle seat (vehicle seat) according to one embodiment of the present invention. The vehicle seat 11 includes a slide rail 13 connected to a floor panel 12 that functions as one component of the vehicle's monocoque structure, a seat cushion 14 supported by the slide rail 13 so as to be movable in the front-rear direction and to receive the buttocks and thighs of an occupant, a seat back 15 connected to the seat cushion 14 so as to be swingable in the front-rear direction about a swing axis SX and to receive the back of the occupant, and a headrest 16 supported by the upper end of the seat back 15 and to receive the head of the occupant. The seat cushion 14, the seat back 15, and the headrest 16 each have upholstery materials 14a, 15a, and 16a that encase the internal pads. The upholstery materials 15a and 16a are in close contact with the outer surface of the pad following the depression of the pad due to the action of a hanging thread 17. The details of the pad will be described later. The vehicle seat 11 is configured for a left seat. When the vehicle seat 11 is used as a right-hand seat, the left and right sides of the vehicle seat 11 can be swapped.

The seat cushion 14 includes a side cover 18. A first lever (operator) 19a and a second lever (operator) 19b are attached to the side cover 18. The first lever 19a is supported so as to be freely pivotable around an axis parallel to the rotation axis SX. When the first lever 19a is pulled upward around the axis, the seat cushion 14 and the seat back 15 move upward. When the first lever 19a is pushed downward around the axis, the seat cushion 14 and the seat back 15 move downward. The second lever 19b is supported so as to be freely pivotable around the rotation axis SX. When the second lever 19b is pulled upward around the swing axis SX, the lock between the seat cushion 14 and the seat back 15 is released around the swing axis SX. The swing of the seat back 15 around the swing axis SX is permitted. The seat back 15 is driven forward around the swing axis SX by the action of a spring force. When an external force is applied to the seat back 15 rearward about the swing axis SX against the spring force, the seat back 15 can be driven rearward about the swing axis SX. When the second lever 19b is released from the pulling force about the swing axis SX, a lock is established between the seat cushion 14 and the seat back 15 about the swing axis SX. The angle of the seat back 15 can be fixed about the swing axis SX.

A third lever (operator) 19c is attached to the seat cushion 14. The third lever 19c is supported so as to be freely swingable around an axis parallel to the swing axis SX. When the third lever 19c is pulled upward around the axis, the lock is released between the seat cushion 14 and the slide rail 13. Linear movement of the seat cushion 14 on the slide rail 13 is permitted. When an external force is applied to the seat cushion 14 in the forward or backward direction, the seat cushion 14 can be displaced along the slide rail 13. When the third lever 19c is released from the pulling force around the axis, the lock is established between the seat cushion 14 and the slide rail 13. The position of the seat cushion 14 can be fixed in the front-to-rear direction on the slide rail 13.

The headrest 16 is fixed to a headrest pillar 21 that extends upward from the upper end of the seat back 15. The headrest pillar 21 is supported by the seat back 15 so that it can be displaced axially in the up and down direction. The height of the headrest 16 can be adjusted according to the displacement of the headrest pillar 21.

2, the vehicle seat 11 includes a seat frame 23 that supports a pad. The seat frame 23 includes a seat cushion frame 24 that supports the pad of the seat cushion 14, a seat back frame 25 that is connected to the seat cushion frame 24 so as to be swingable around a swing axis SX and supports the pad of the seat back 15, and a base frame 26 that is guided by the slide rail 13 so as to be movable back and forth in the longitudinal direction and supports the seat cushion frame 24 on the slide rail 13. The seat cushion frame 24 is connected to the base frame 26 by a link mechanism 27. The link mechanism 27 includes a link member 28 having one end that is connected to the base frame 26 so as to be rotatable around a horizontal axis FH that extends in the left-right direction parallel to the swing axis SX, and the other end that is connected to the seat cushion frame 24 so as to be rotatable around a horizontal axis SH that extends in the left-right direction parallel to the horizontal axis FH. The link member 28 guides the up-down movement of the seat cushion frame 24 relative to the base frame 26 around the horizontal axis FH.

The seat cushion frame 24 includes cushion side frames 24a extending in parallel with each slide rail 13, a pan frame 24b connecting the cushion side frames 24a at the front end of the seat cushion 14, and a connecting pipe 24c connecting the cushion side frames 24a at the rear end of the seat cushion 14. A number of S springs (not shown) are arranged between the pan frame 24b and the connecting pipe 24c. Each S spring extends forward and backward in a zigzag shape. The zigzag shape is formed by alternating wires extending in the forward and backward directions and wires extending in the left and right directions.

A manual forward/backward movement device 29 is attached to the base frame 26. The third lever 19c is connected to the manual forward/backward movement device 29. The manual forward/backward movement device 29 switches between locking and unlocking the movement of the base frame 26 on the slide rail 13 in response to the swinging of the third lever 19c.

A manual up-down movement device 31 is attached to the cushion side frame 24a of the seat cushion frame 24. The manual up-down movement device 31 is supported by the cushion side frame 24a and includes a transmission mechanism 32 connected to the link mechanism 27. The transmission mechanism 32 is disposed on the outside of the cushion side frame 24a and causes the link member 28 to rotate about the horizontal axis SH relative to the cushion side frame 24a in response to the driving force transmitted from the first lever 19a about the axis. The transmission mechanism 32 may include, for example, a drive gear fixed to the pivot shaft of the first lever 19a and a driven gear fixed to the link member 28 about the horizontal axis SH.

The seat back frame 25 includes left and right side frames 35 connected to the inside of each cushion side frame 24a by the reclining unit (reclining mechanism) 34, a lower frame 36 connecting the lower ends of the side frames 35 to each other around the reclining unit 34, and an upper frame 37 connecting the upper ends of the side frames 34 to each other above the lower frame 36. The side frame 35 has a plate-shaped portion 35a that spreads along a vertical plane perpendicular to the swing axis SX around the reclining unit 34 and extends upward along the vertical plane, a front wall 35b that is continuous with the front edge of the plate-shaped portion 35a and bent inward to form a curved region 38 extending vertically from around the reclining unit 34, and a rear wall 35c that is continuous with the rear edge of the plate-shaped portion 35a and bent inward to form a curved region 39 extending vertically from around the reclining unit 34. A side frame flange 41 is formed on the rear wall 35c by bending the inner end of the rear wall 35c forward. Each side frame 35 is formed, for example, from a single metal plate. A headrest pillar guide 42 is fixed to the upper frame 37, which supports the headrest pillar 21 so that it can slide up and down. Details of the upper frame 37 will be described later.

The reclining unit 34 includes a rotating body 43 that is supported so as to be rotatable relative to the seat cushion frame 24 and the seat back frame 25. A shaft body 44 is coupled to one of the rotating bodies (here, the left rotating body) 43 coaxially with the swing axis SX. The second lever 19b is fixed to the shaft body 44. The relative rotation of the seat cushion frame 24 and the seat back frame 25 is locked and unlocked according to the rotation of the rotating body 43. The left and right reclining units 34 are connected to each other by a connecting shaft 45. The connecting shaft 45 can rotate around the swing axis SX. The connecting shaft 45 transmits the rotation of one rotating body (here, the left rotating body) 43 to the other rotating body (here, the right rotating body) 43. In this way, the operation of the second lever 19b is transmitted from one reclining unit 34 to the other reclining unit 34.

As shown in FIG. 3, the seat cushion 14 further includes a seat cushion pad 46 supported by the seat cushion frame 24 and wrapped in the upholstery material 14a. The seat back 15 further includes a seat back pad 47 supported by the seat back frame 25 and wrapped in the upholstery material 15a. The seat cushion pad 46 and the seat back pad 47 are made of a resilient material such as urethane foam.

As shown in Figures 4 to 6, the lower frame 36 has a back region 51 that is disposed behind the swing axis SX and joined to the rear wall 35c of the side frame 35 from the rear to connect the left and right side frames 35 to each other, and a reinforcement region 52 that continues from the lower edge of the back region 51, spreads forward from the swing axis SX, and is joined to the front wall 35b from the rear. The reinforcement region 52 has a generatrix perpendicular to the plate-shaped portion 35a of the side frame 35 and curves around the swing axis SX along the edge of the plate-shaped portion 35a. The curved reinforcement region 52 increases the torsional rigidity of the lower frame 36 around the swing axis SX. The lower frame 36 is formed, for example, from a single metal plate.

The back region 51 has a flat plate portion 51a extending along the first plane Pf, and a flange 51b that is continuous from the upper edge of the flat plate portion 51a and bent forward. The upper edge of the flat plate portion 51a includes a first edge 53a that extends from the left-right center position in the left-right direction parallel to the swing axis SX, a second edge 53b that extends while curving upward from the left and right ends of the first edge 53a, and a third edge 53c that extends from the upper ends of the second edge 53b toward the outside parallel to the swing axis SX and is overlapped on the side frame 35. The flange 51b is continuous with the first edge 53a and the second edge 53b, is interrupted at the upper end of the second edge 53b, and is faced to the side frame flange 41.

Weld marks 54 are formed in the back region 51 at positions where they overlap with the left and right side frames 35. Here, the weld marks 54 are composed of weld beads formed along the edges of the side frames 35. The left and right side frames 35 are joined to the back region 51 of the lower frame 36 by the weld marks 54. Spot welding and laser welding can also be used for welding.

Two insertion holes 55 are formed in the back region 51 at positions that are offset from each of the side frames 35. The insertion holes 55 are positioned apart in the axial direction of the swing axis SX at a distance that allows the lower frame 36 to be stably supported when the lower frame 36 is supported by a pin that stands upright in the vertical direction (gravity direction). The insertion holes 55 have, for example, a circular outline.

Two openings 56 are formed in the back region 51, at positions spaced apart from the individual side frames 35 and closer to the center in the left-right direction than the two insertion holes 55. The openings 56 are spaced apart in the axial direction of the swing axis SX at a distance that allows the connecting shaft 45 to be stably supported when the connecting shaft 45 is supported by a jig that stands upright in the vertical direction (gravity direction). The openings 56 have, for example, a circular outline.

As shown in FIG. 5, the back region 51 is formed with a first receiving surface 57 that expands within the first plane Pf and is supported from the rear when the seat back frame 25 is assembled. The insertion hole 55 and the opening 56 are drilled in the first receiving surface 57. Here, the opening 56 may be partially expanded in the reinforcement region 52. The connecting shaft 45 is formed with a square body 58 that is disposed in front of the opening 56 and is held by a jig as described later. The square body 58 is disposed in a cylindrical space surrounded by a virtual cylindrical surface that is inscribed in the opening 56 while being perpendicular to the first plane Pf. The square body 58 can be formed, for example, by flattening a round tube to have a square cross-sectional shape.

7, the front wall 35b of the side frame 35 has a first height Hf from the plate-shaped portion 35a in the axial direction of the swing axis SX. The front wall 35b is disposed offset in the axial direction of the swing axis SX from a virtual plane Se that includes the edge of the lower frame 36 and is perpendicular to the swing axis SX. The rear wall 35c of the side frame 35 is adjacent to the front wall 35b with a space 59 between them along the periphery of the plate-shaped portion 35a around the swing axis SX, and has a low wall 61a having a first height Hf from the plate-shaped portion 35a in the axial direction of the swing axis SX, and a high wall portion 61b that is continuous with the low wall portion 61a and has a second height Hs greater than the first height Hf from the plate-shaped portion 35a in the axial direction of the swing axis SX. The curved region 38 of the front wall 35b and the curved region 39 of the rear wall 35c are separated by the space 59. As shown in FIG. 4, the high wall portion 61b is positioned above an imaginary plane Le that is perpendicular to the first plane Pf and contacts the front edge of the reinforced region 52 from above.

7, the front wall 35b of the side frame 35 is formed with an overlapping piece 62 that spreads inward from the inner edge of the first height Hf and overlaps the reinforcement area 52 of the lower frame 36 from the front. A welding mark 63 is formed on the edge of the overlapping piece 62 at a position where it overlaps with the reinforcement area 52. Here, the welding mark 63 is composed of a weld bead formed along the edge of the overlapping piece 62. The left and right side frames 35 are joined to the reinforcement area 52 of the lower frame 36 by the welding mark 63. Spot welding and laser welding can also be used for welding. As shown in FIG. 4, the overlapping piece 63 is positioned below a virtual plane Le that is perpendicular to the first plane Pf and contacts the front edge of the reinforcement area 52 from above.

As shown in FIG. 5, each side frame 35 has a second receiving surface 64 that extends within a second plane Ps that is set in a predetermined positional relationship with the first plane Pf and is supported from behind when the seat back frame 25 is assembled. Here, the second plane Ps is set parallel to the first plane Pf. An insertion hole 65 that opens into the second receiving surface 64 at a position offset from the lower frame 36 is formed in the rear wall 35c of the side frame 35. The insertion hole 65 has, for example, a circular outline.

2, auxiliary insertion holes 66 are formed in the rear wall 35c of each side frame 35 at a position above the insertion hole 65 and away from the upper frame 37. The auxiliary insertion holes 66 are positioned away from the insertion hole 65 in the vertical direction at a distance that allows the side frame 35 to be stably supported in cooperation with the insertion hole 65 when the side frame 35 is supported by a pin that stands vertically (in the direction of gravity) like the insertion hole 65. The auxiliary insertion holes 66 have, for example, a circular outline. The auxiliary insertion holes 66 expand within an auxiliary plane that is set in a predetermined positional relationship with the first plane Pf, and open at an auxiliary support surface that is supported from behind when the seat back frame 25 is assembled.

As shown in FIG. 8, the upper frame 37 is formed by bending a plate material, and has a front wall 69 divided by an upper ridge 67 and a lower ridge 68 extending horizontally, an upper wall 71 continuing from the upper ridge 67 and extending rearward, an upper wall 72 bending upward from the rear end of the upper wall 71, a lower wall 73 continuing from the lower ridge 68 and extending rearward, and a lower wall 74 bending downward from the rear end of the lower wall 73. A first flange 75 is connected to the upper wall 72, which is continuous from the upper end of the upper wall 72 and bending forward. The first flange 75 is continuous horizontally along the upper edge of the upper wall 72 over the entire area. A second flange 76 is connected to the lower wall 74, which is continuous from the lower end of the lower wall 74 and bending forward. The second flange 76 is continuous horizontally along the lower edge of the lower wall 74 over the entire area.

The front wall 69 is horizontally folded forward at two points, left and right, to form recesses along vertical valley fold lines 77, and has connecting pieces 69a extending outward. The connecting pieces 69a are further folded backward horizontally outside the recesses to form ridge lines along vertical mountain fold lines 78. As the front wall 69 deforms, the upper wall 72 and lower wall 74 deform in the same way. The upper frame 37 is formed, for example, from a single metal plate.

A weld mark 79 is formed on the front wall 69 horizontally outside the mountain fold line 78. Here, the weld mark 79 is composed of a weld bead formed along the edges of the left and right side frames 35. Weld marks 81, 82 are formed on the upper wall 72 and the lower wall 74 corresponding to the top and bottom of the weld mark 79. Here, the weld marks 81, 82 are composed of weld beads formed along the edges of the left and right side frames 35. The upper frame 37 is fixed to the left and right side frames 35 by the weld marks 79, 81, 82. Spot welding and laser welding can also be used for welding.

9, the inner edge of the front wall 35b has a protrusion 83 that spreads inward from an imaginary outline 83a corresponding to the edge of the upper frame 37 and overlaps the front wall 69 of the upper frame 37 from the rear. The front wall 69 of the upper frame 37 forms a weld mark 79 between the protrusion 83 and the front wall 69. The inner edge of the rear wall 35c has an upper overlap area 84 that overlaps the upper wall 72 of the upper frame 37 from the rear, and a lower overlap area 85 that overlaps the lower wall 74 of the upper frame 37 from the rear, below the upper overlap area 84 and spaced apart from the upper overlap area 84. The upper wall 72 of the upper frame 37 forms a weld mark 81 between the upper overlap area 84 and the upper overlap area 84. Similarly, the lower wall 74 of the upper frame 37 forms a weld mark 82 between the lower overlap area 85 and the upper overlap area 85.

As shown in FIG. 10, the upper frame 37 has a first through hole 87 formed in the upper wall 71 for receiving the headrest pillar guide 86, and a second through hole 88 formed in the lower wall 73 for receiving the headrest pillar guide 86. The headrest pillar guide 86 supports the headrest pillar 21 so that it can be displaced in the axial direction. The headrest pillar guide 86 is formed with a positioning flange 89 that expands in a direction perpendicular to the axis. When the headrest pillar guide 86 is inserted from above into the first through hole 87 and the second through hole 88, the positioning flange 89 comes into contact with the upper wall 71 from above to position the headrest pillar guide 86 in the axial direction. The headrest pillar guide 86 can be molded, for example, from a resin material.

A support hole flange 91 is formed by bending downward around the periphery of each of the first through hole 87 and the second through hole 88. The headrest pillar guide 86 is press-fitted into the support hole flange 91. The support hole flange 91 fixes the headrest pillar guide 86 to the upper frame 37. The support hole flange 91 prevents the headrest pillar guide 86 from coming off the upper frame 37.

As shown in FIG. 11, a receiving piece 92 is formed on the first flange 75 rearward of the first through-hole 87 by bending downward from the front edge of the first flange 75. The receiving piece 92 receives the headrest pillar guide 86 from the rear. The load acting on the headrest pillar guide 86 from the front is supported by the upper wall 72 of the upper frame 37. Alternatively, the receiving piece 92 may be bent upward from the front edge of the first flange 75.

As shown in FIG. 8, a bead (reinforcing shape) 93 is formed in the recess of the front wall 69, extending while intersecting the valley fold line 77 and reinforcing the rigidity of the front wall 69 in the bending direction. The bead 93 extends horizontally in the left-right direction. Similarly, a bead (reinforcing shape) 94 is formed in the front wall 69, extending while intersecting the headrest pillar 21 in a front view and reinforcing the rigidity of the front wall 69 in the in-plane direction. The bead 94 is inclined so as to be displaced upward as it moves outward from the bottom end near the center.

Two insertion holes 95 are formed in the front wall 69 in the area between the two recesses. The insertion holes 95 are arranged apart in the axial direction of the swing axis SX at a distance that allows the upper frame 37 to be stably supported when supported by a pin standing in the vertical direction (gravity direction). The insertion holes 95 have, for example, a circular outline. As shown in FIG. 10, the insertion holes 95 widen within a third plane Pt that is set in a predetermined positional relationship with the first plane Pf (or auxiliary plane), and open at a third receiving surface 96 that is supported from the rear when the seat back frame 25 is assembled.

Next, a manufacturing method of the seatback frame 25 will be described. To assemble the seatback frame 25, the lower frame 36, the left and right side frames 35, and the upper frame 37 are prepared. As shown in FIG. 12, the lower frame is installed on the first plane Pf. To install the lower frame, the plug pin 101 is inserted into the plug hole 55. The plug pin 101 is formed, for example, in a cylindrical shape with an axis that stands in the vertical direction (gravity direction). The plug pin 101 has a step 101a that defines the first plane Pf that is perpendicular to the axis. The step 101a of the plug pin 101 receives the first receiving surface 57 of the lower frame 36. The lower frame 36 is positioned with respect to the first plane Pf by inserting the plug pin 101 into the plug hole 55.

Next, as shown in FIG. 13, the left and right side frames 35 are arranged on the lower frame 36. When arranging, the plug pin 102 is inserted into the plug hole 65 of the side frame 35. The plug pin 102 is formed, for example, in a cylindrical shape with an axis that stands in the vertical direction (gravity direction). The plug pin 102 has a step 102a that defines a second plane Ps perpendicular to the axis. The second receiving surface 64 of the side frame 35 is received in the step 102a of the plug pin 102. At this time, an auxiliary plug pin (not shown) is further inserted into the auxiliary plug hole 66 of the side frame 35. The auxiliary plug pin is formed, for example, in a cylindrical shape with an axis that stands in the vertical direction (gravity direction). The auxiliary plug pin has a step that defines an auxiliary plane. The auxiliary receiving surface of the side frame 35 is received in the step of the auxiliary plug pin. The side frame 35 is supported by the second plane Ps and the auxiliary plane. Since the second plane Ps and the auxiliary plane are disposed in a determined positional relationship with respect to the first plane Pf, the left and right side frames 35 can be positioned with high precision with respect to the lower frame 36. The side frame 35 can be overlapped on the lower frame 36 in the axial direction of the plug pin 102. The rear wall 35c of the side frame 35 is overlapped on the back region 51 of the lower frame 36. The front wall 35b of the side frame 35 is overlapped on the reinforcement region 52 of the lower frame 36 in the axial direction of the plug pin 102. The side frame 35 positioned in this manner is welded to the lower frame 36. Weld marks 54, 63 are formed.

Next, as shown in FIG. 14, the upper frame 37 is placed on the left and right side frames 35. When placing, the plug pin 103 is inserted into the plug hole 95 of the upper frame 35. The plug pin 103 is formed in a cylindrical shape with an axis that stands vertically (in the direction of gravity), for example. The plug pin 103 has a step 103a that defines a third plane Pt perpendicular to the axis. The third receiving surface 96 of the upper frame 37 is received by the step 103a of the plug pin 103. Since the third plane Pt is placed in a determined positional relationship with respect to the first plane Pf and the auxiliary plane, the upper frame 37 can be positioned with high precision with respect to the left and right side frames 35. The upper frame 37 can be overlapped on the side frame 35 from the axial direction of the plug pin 103. The front wall 69 of the upper frame 37 is overlapped on the protruding piece 83 from the axial direction of the plug pin 103. The upper wall 72 of the upper frame 37 is overlapped with the upper overlap area 84 of the rear wall 35c from the axial direction of the insertion pin 103. When overlapping, interference between the upper wall 72 and the front wall 35b can be avoided. Similarly, the lower wall 74 of the upper frame 37 is overlapped with the lower overlap area 85 of the rear wall 35c from the axial direction of the insertion pin 103. When overlapping, interference between the lower wall 74 and the front wall 35b can be avoided. The upper frame 37 positioned in this way is welded to the left and right side frames 35. Weld marks 79, 81, and 82 are formed.

As shown in FIG. 15, when the lower frame 36 is received on the insertion pin 101, the jig 104 enters the opening 56 in the back region 51. A square groove 104a is engraved at the tip of the jig 104 coaxially with the swing axis SX. The square body 58 of the connecting shaft 45 can be fitted into the square groove 104a. In this way, the connecting shaft 45 can be positioned relative to each side frame 35. Both ends of the positioned connecting shaft 45 are welded to the rotating body 43 of the reclining unit 34.

In the seat back frame 25 according to this embodiment, the lower frame 36 has a reinforcing region 52 that extends from the lower edge of the back region 51 toward the front of the swing axis SX and is joined to the front wall 35b of the side frame 35 from the rear. The lower frame 36 is joined to each side frame 35 at the reinforcing region 52 that extends from the lower edge of the back region 51 toward the front of the swing axis SX in addition to the back region 51. The torsional rigidity of the seat back frame 25 can be increased. Compared to the case where the lower frame 36 is joined to the side frame only at the back region 51, the joining strength of the lower frame 36 and the side frame 35 can be reduced. In this way, the joining work load can be reduced. Moreover, when assembling the seat back frame 25, the lower frame 36 can be assembled to the side frame 35 from the rear. The side frame 35 can be assembled to the lower frame 36 from one direction. The workability of the assembly is not impaired.

The side frame 35 has a space 59 formed between the front wall 35b and the rear wall 35c along the periphery of the plate-shaped portion 35a around the reclining unit 34. The front wall 35b, which is bent and molded along the periphery of the plate-shaped portion 35a around the reclining unit 34, and the rear wall 35c, which is bent and molded along the periphery of the plate-shaped portion 35a around the reclining unit 34, are separated by the space 59. When drawing the side frame 35, the shape precision of the front wall 35b and the rear wall 35c can be improved compared to when the front wall 35b and the rear wall 35c are continuous around the reclining unit 34. Therefore, the side frame 35 can be assembled stably to the lower frame 36.

In this embodiment, an opening 56 is formed in the back region 51 of the lower frame 36 to allow the jig 104 to pass through when assembling the seat back frame 25. Meanwhile, the connecting shaft 45 is formed with a square body 58 that is disposed in front of the opening 56 and held by the jig 104. When assembling the seat back frame 25, the jig 104 can be inserted into the opening 56 from the rear. The square body 58 of the connecting shaft 45 can be held by the jig 104. In this way, the connecting shaft 45 can be positioned relative to the left and right rotating bodies 43. The connecting shaft 45 can be joined to each rotating body 43 with good work efficiency.

A first receiving surface 57 is formed in the back region 51 of the lower frame 36, which spreads in the first plane Pf and is supported from the rear. A second receiving surface 64 is formed in the rear wall 35c of the side frame 35, which spreads in a second plane Ps set in a determined positional relationship with the first plane Pf and positions the side frame 35 relative to the lower frame 36 when supported from the rear. When the seat back frame 25 is assembled, the lower frame 36 can be physically supported by the first receiving surface 57. When the side frame 35 is physically supported by the second receiving surface 64, the left and right side frames 35 can be positioned relative to the lower frame 36 based on the positional relationship between the first plane Pf and the second plane Ps. The side frames 35 can be easily positioned relative to the lower frame 36.

In addition, the upper frame 37 is formed with a third receiving surface 96 that spreads within a third plane Pt that is set in a determined positional relationship with respect to the second plane Ps, and positions the upper frame 37 relative to the side frame 35 when supported from the rear. When the upper frame 37 is physically supported by the third receiving surface 96, the upper frame 37 can be positioned relative to the side frame 35 based on the positional relationship between the second plane Ps and the third plane Pt. The upper frame 37 can be easily positioned relative to the side frame 35.

In the side frame 35 according to this embodiment, a protrusion 83 is formed on the inner edge of the front wall 35b, which spreads inward from an imaginary outline 83a corresponding to the shape of the upper frame 37 and overlaps the front wall 69 of the upper frame 37 from the rear. The upper frame 37 can be assembled from the front to the left and right side frames 35, which are spaced apart during assembly. At this time, the front wall 35b of the side frame 35 does not interfere with the upper standing wall 72 and lower standing wall 74, which are located rearward of the front wall 69 of the upper frame 37. In this way, the work efficiency can be improved when assembling the upper frame 37.

The front wall 69 of the upper frame 37 is horizontally folded forward at two points, left and right, to form a recess along the vertical valley fold line 77 and has a connecting piece 69a extending toward the protrusion 83. A bead 93 is formed in the recess of the front wall 69, extending while intersecting the valley fold line 77 and reinforcing rigidity in the bending direction. The rigidity of the front wall 69 against bending along the valley fold line 77 can be increased. Therefore, deformation of the upper frame 37 can be suppressed when the upper frame 37 is assembled. The efficiency of the assembly work can be improved.

A bead 94 is formed on the front wall 69 of the upper frame 37, which extends while intersecting the headrest pillar 21 in a front view and reinforces the rigidity in the in-plane direction. In the upper frame 37, the rigidity of the front wall 69 can be increased in correspondence with the first through-hole 87 in the top wall 71 and the second through-hole 88 in the bottom wall 73. Therefore, deformation of the upper frame 37 can be suppressed when the upper frame 37 is assembled. The efficiency of the assembly work can be improved.

In the upper frame 37 according to this embodiment, a receiving piece 92 is formed on the first flange 75 behind the first through hole 87, which is continuous from the front edge of the first flange 75 and is bent downward. The rigidity of the front wall 69 can be increased in correspondence with the first through hole 87 of the upper wall 71 and the second through hole 88 of the lower wall 73. Therefore, deformation of the upper frame 37 can be suppressed when the upper frame 37 is assembled. The efficiency of the assembly work can be improved.

As shown in FIG. 16(A), a cutout opening 105 may be formed in the front wall 69 of the upper frame 37 between the left and right beads 94. The cutout opening 105 can contribute to reducing the weight of the upper frame 37. The bead 94 can suppress the decrease in rigidity caused by the formation of the cutout opening 105. As shown in FIG. 16(B), in addition to the cutout opening 105 in the front wall 69, the upper frame 37 may have a cutout opening 106 formed in the lower standing wall 74. The cutout opening 106 can further contribute to reducing the weight of the upper frame 37. As shown in FIG. 16(C), the lower standing wall 74 itself may be shortened in the vertical direction. In this case, the bead 93 may be extended toward the mountain fold line 78.

As shown in FIG. 17, the connecting shaft 45 itself may be formed of a square tube. In this case, the square tube forms a square body 58 in front of the opening 56.

18, a support tube 107 is fixed to the upper wall 71 and the lower wall 73 of the upper frame 36. The support tube 107 is inserted into the first through hole 87 and the second through hole 88 to support the headrest pillar guide 86. The support tube 107 is made of, for example, a metal material. Here, small pieces 108 and 109 are bent upward and downward from the periphery of the first through hole 87 and the second through hole 88, respectively. As shown in FIG. 19, each small piece 108 and 109 is superimposed on the outer surface of the support tube 107. The small pieces 108 and 109 are welded to the support tube 107. The welding can be performed from the front, similar to the welding of the upper frame 37 and the side frame 35, so that the work efficiency of assembling the seat frame 23 is improved. The headrest pillar guide 86 is press-fitted into the support tube 107.

The support tube 107 is supported from the rear by the receiving piece 92. The support tube 107 and the receiving piece 92 work together to increase the rigidity of the front wall 69. Therefore, deformation of the upper frame 37 can be suppressed when the upper frame 37 is assembled. The efficiency of the assembly work can be improved.

11...vehicle seat (vehicle seat), 21...headrest pillar, 24...seat cushion frame, 25...seat back frame, 34...reclining mechanism (reclining unit), 35...side frame, 35a...plate-shaped portion, 35b...front wall, 35c...rear wall, 36...lower frame, 37...upper frame, 38...curved region, 39...curved region, 45...connecting member (connecting shaft), 51...back region, 52...reinforcement region, 56...opening, 57...first receiving surface, 58...corner, 59...space, 64...second receiving surface, 67...upper ridge, 6 8...lower ridgeline, 69...front wall, 69a...connecting piece, 71...upper wall, 72...upper wall, 73...lower wall, 74...lower wall, 75...flange (first flange), 77...valley fold line, 83...projection piece, 83a...imaginary contour line, 86...headrest pillar guide, 87...through hole (first through hole), 88...through hole (second through hole), 92...receiving piece, 93...reinforcing shape (bead), 94...reinforcing shape (bead), 96...third receiving surface, 104...jig, 107...support tube, Pf...first plane, Ps...second plane, Pt...third plane, SX...rotation axis (swing axis).

Claims (10)

left and right side frames (35) each having a plate-like portion (35a) that spreads around a rotation axis along a vertical plane perpendicular to the rotation axis line (SX) and extends upward along the vertical plane, a front wall (35b) that extends inward from a front edge of the plate-like portion (35a), and a rear wall (35c) that extends inward from a rear edge of the plate- like portion (35a);
A lower frame (36) having a back region (51) connecting the left and right side frames (35) to each other;
A vehicle seat (11) including a seat back frame (25) having an upper frame (37) that connects the left and right side frames (35) to each other above the lower frame (36),
The spine region (51) is joined to a rear surface of the rear wall (35c) in the seat front-rear direction ,
the lower frame (36) has a reinforcement region (52) that is continuous with a lower edge of the back region (51), extends forward of the rotation axis (SX), and is joined to a rear surface of the front wall (35b) in the seat front-rear direction ,
When viewed from the front, the rear wall (35c) is positioned at a position that avoids overlapping with the front end of the reinforcement area (52) and at a position that overlaps with the back region (51). The vehicle seat according to claim 1,
A weld mark (63) is formed at the joint between the front wall (35b) and the reinforcement area (52),
The vehicle seat is characterized in that the weld mark (63) is located at a position that does not overlap with the rear wall (35c) in a front view. The vehicle seat according to claim 2,
A weld mark (54) is formed at the joint between the rear wall (35c) and the back region (51),
The vehicle seat is characterized in that the weld mark (54) is located at a position that does not overlap with the front wall (35b) in a front view. In the vehicle seat according to any one of claims 1 to 3 , the upper edge of the back region (51) is
A first edge (53a) extending in the left-right direction from a left-right center position in parallel to the rotation axis (SX);
and second edges (53b) extending while curving upward from the left and right ends of the first edge (53a). In the vehicle seat according to claim 4 , the upper edge of the back region (51) is
A vehicle seat comprising a third edge (53c) extending outwardly from upper ends of the second edges (53b) in parallel to the rotation axis (SX) and overlapping the side frame (35). 6. The vehicle seat according to claim 4 or 5 , wherein the rear wall (35c) is
a high wall portion (61b) extending from the plate-shaped portion (35a) to the second edge (53b) in the direction of the rotation axis (SX);
a low wall portion (61a) that is disposed below the high wall portion (61b) and extends from the plate-shaped portion (35a) in the direction of the rotation axis (SX) shorter than the high wall portion (61b),
The bottom wall portion (61a) is formed at a position outside the left and right ends of the front end of the reinforcement region (52),
A vehicle seat, characterized in that the front end of the reinforcement area (52) is located below the high wall portion (61b). 7. The vehicle seat of claim 6 , wherein the first edge (53a) and the second edge (53b) are provided with forwardly extending flanges (51b);
The vehicle seat is characterized in that the flange (51b) is continuous with the first edge (53a) and the second edge (53b) and extends to an upper end of the second edge (53b). 8. The vehicle seat according to claim 7 , wherein the rear wall (35c) is formed with a side frame flange (41) extending forward from an inner end of the rear wall (35c),
The side frame flange (41) extends in the seat up-down direction,
The vehicle seat is characterized in that a lower end of the side frame flange (41) is formed at a lower end on an inner side in the seat width direction of the high wall portion (61b). 9. The vehicle seat according to claim 8 , wherein the flange (51b) is disposed inward in the seat width direction relative to the side frame flange (41). The vehicle seat according to claim 6,
The front wall (35b) of the side frame (35) is formed with an overlapping piece (62) that spreads inward from an inner edge of the front wall (35b) and overlaps the lower frame (36),
The vehicle seat is characterized in that the overlapping piece (62) extends shorter than the high wall portion (61b) and longer than the low wall portion (61a) in the direction of the rotation axis (SX).

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