Vehicle seats

Abstract

To improve bond strength between two frames constituting a hollow frame.SOLUTION: A vehicular seat comprises a first frame 70 and a second frame 80 constituting a hollow frame with a closed cross section. The first frame 70 has two first side walls (71) opposing to each other in a first direction and a first bottom wall connecting the first side walls to each other. The second frame 80 has two second side walls (82) opposing to each other in the first direction and a second bottom wall connecting the second side walls to each other and opposing to the first bottom wall, in a second direction. An edge at the opposite side of the first bottom wall of one first side wall 71 has a first protruding edge part E11 joined to one second wall 82, and a first base edge part E12 arranged closer to the first bottom wall than the first protruding edge part E11, which is joined to the one second side wall 82. A welding mark WP at which the first protruding edge part E11 is joined to the second side wall 82 and a welding mark WP at which the first base edge part E12 is joined to the second side wall 82 are arranged at different positions in the second direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle seat having a hollow frame with a closed cross-section.

Background Art

[0002] Conventionally, as a vehicle seat, there is known one having a hollow frame with a closed cross-section shape composed of two frames having a U-shaped cross-section as side frames of a seat back (see Patent Document 1). In this structure, a retractor mounting bracket for mounting a retractor for winding a seat belt can be well supported by a hollow frame with a highly rigid closed cross-section shape.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is required to improve the joining strength of the two frames constituting the hollow frame with a closed cross-section shape as compared with the conventional one.

[0005] Therefore, an object of the present invention is to improve the joining strength of the two frames constituting the hollow frame.

Means for Solving the Problems

[0006] In order to solve the above problems, a vehicle seat according to the present invention includes a first frame and a second frame having a U-shaped cross-section in a cross-sectional view, which constitute a hollow frame with a closed cross-section. The first frame has two first side walls facing each other in a first direction and a first bottom wall connecting the two first side walls. The second frame comprises two second side walls facing each other in a first direction, and a second bottom wall connecting the two second side walls, the second bottom wall facing the first bottom wall in a second direction. The edge of one of the first side walls opposite to the first bottom wall has a plurality of protruding shapes, including a first protruding edge which is the tip of the protruding shape and is joined to one of the second side walls, and a first base edge which is closer to the first bottom wall than the first protruding edge and is joined to one of the second side walls. The weld marks joining the first protruding edge and the second side wall, and the weld marks joining the first base edge and the second side wall are located at different positions in the second direction.

[0007] With this configuration, the weld marks joining one first side wall of the first frame and one second side wall of the second frame can be positioned at different locations in the second direction, thereby improving the joint strength between the first frame and the second frame.

[0008] Furthermore, the first bottom wall may have a first recess, the second bottom wall may have a second recess, and the first recess and the second recess may face each other in the second direction.

[0009] This configuration makes it possible to improve the rigidity of the hollow frame against external forces applied from a second direction.

[0010] Furthermore, the first recesses are recessed toward the second bottom wall and two are provided spaced apart in the longitudinal direction of the first frame, and the first bottom wall may have a first convex portion that protrudes away from the second bottom wall and is located between the two first recesses in the longitudinal direction of the first frame.

[0011] This configuration allows for further improvement of the rigidity of the first frame.

[0012] Furthermore, the hollow frame may be one of the left or right side frames of the seat back frame, and the vehicle seat may include a pipe frame having a first portion that extends in the left-right direction and is joined to the upper end of the hollow frame, and a cover member that covers the joint between the upper end of the hollow frame and the first portion and is joined to the hollow frame and the first portion.

[0013] This configuration allows for improved rigidity of the upper corner portion of the seat back frame.

[0014] Furthermore, the vehicle seat may further include a retractor mounting bracket to which a retractor for winding up a seat belt is attached, the retractor mounting bracket being joined to the hollow frame, the retractor mounting bracket having third side walls facing each other in the left-right direction, a third bottom wall connecting the two third side walls, an annular bead formed on the third bottom wall, the annular bead surrounding the joint between the mounting member for attaching the retractor to the third bottom wall and the third bottom wall, and a linear bead extending from the annular bead in the left-right direction and wrapping around to the third side wall.

[0015] This configuration improves the rigidity of the retractor mounting bracket, allowing the retractor to be stably supported by the bracket.

[0016] Furthermore, the vehicle seat further comprises a reinforcing pipe connecting the hollow frame and the other left and right side frames, the reinforcing pipe being positioned in front of the retractor mounting bracket and joined to the retractor mounting bracket, wherein the portion of the reinforcing pipe located in front of the retractor mounting bracket is bent forward, and the portion adjacent to the other side frame is bent downward.

[0017] According to this configuration, the rigidity of the reinforcing pipe that supports the retractor mounting bracket can be improved, so that the retractor can be stably supported by the retractor mounting bracket and the reinforcing pipe.

[0018] Further, the vehicle seat may further include a reclining bracket having a plurality of holes arranged in a ring for attaching a reclining unit that tilts the seat back frame, the reclining bracket being joined to the lower end of the hollow frame.

[0019] According to this configuration, the reclining unit can be stably attached to the reclining bracket while suppressing an increase in the weight of the reclining bracket by the plurality of holes arranged in a ring.

[0020] Further, the pipe frame has a second portion extending downward from an end portion of the first portion opposite to the hollow frame, and the other side frame on the left and right may have two third recesses sandwiching the second portion and an X-shaped bead disposed below the third recess.

[0021] According to this configuration, the second portion of the pipe frame is sandwiched by the two third recesses of the other side frame, so that the connection strength between the other side frame and the pipe frame can be improved. Further, since the other side frame has an X-shaped bead, the rigidity of the other side frame can be improved.

[0022] Further, the pipe frame may be formed in a U shape by having a third portion extending from the lower end portion of the second portion toward the hollow frame and joined to the hollow frame.

[0023] According to this configuration, the rigidity of the seat back frame can be improved while suppressing an increase in the number of parts.

[0024] Further, the first concave portion and the second concave portion each have a hole through which the third portion passes, and the third portion may be joined to the hollow frame while being inserted into the hole.

[0025] According to this configuration, it is possible to improve the joining strength between the hollow frame and the pipe frame while facilitating the assembly work of the hollow frame and the pipe frame.

Effects of the Invention

[0026] According to the present invention, it is possible to improve the joining strength between the first frame and the second frame constituting the hollow frame.

[0027] Further, by opposing the first concave portion provided on the first bottom wall of the first frame and the second concave portion provided on the second bottom wall of the second frame in the second direction, the rigidity of the hollow frame against an external force applied from the second direction can be improved.

[0028] Further, by arranging the first convex portion between the two first concave portions, the rigidity of the first frame can be further improved.

[0029] Further, by using the hollow frame as one of the left and right side frames of the seat back frame, joining the first portion of the pipe frame to the upper end portion of the hollow frame, covering the joining portion between the hollow frame and the first portion with a cover member, and joining the cover member to the hollow frame and the first portion, the rigidity of the upper corner portion of the seat back frame can be improved.

[0030] Further, by providing an annular bead and a linear bead on the retractor mounting bracket to which the retractor is attached, the rigidity of the retractor mounting bracket can be improved, so that the retractor can be stably supported by the retractor mounting bracket.

[0031] Furthermore, by bending the reinforcing pipe to which the retractor mounting bracket is joined, the rigidity of the reinforcing pipe can be improved, allowing the retractor to be stably supported by the retractor mounting bracket and the reinforcing pipe.

[0032] Furthermore, by forming multiple holes arranged in a ring shape on the reclining bracket, the reclining unit can be stably attached to the reclining bracket while suppressing an increase in the weight of the reclining bracket.

[0033] Furthermore, by sandwiching the second portion of the pipe frame between the two third recesses of the other side frame, the connection strength between the other side frame and the pipe frame can be improved. Additionally, by forming an X-shaped bead on the other side frame, the rigidity of the other side frame can be improved.

[0034] Furthermore, by having a third portion that extends from the lower end of the second portion toward the hollow frame and is joined to the hollow frame, the rigidity of the seat back frame can be improved while suppressing an increase in the number of parts.

[0035] Furthermore, by forming holes in the first and second recesses and joining the third portion to the hollow frame while it is inserted into the holes, the assembly work of the hollow frame and the pipe frame can be made easier while improving the joint strength between the hollow frame and the pipe frame. [Brief explanation of the drawing]

[0036] [Figure 1] This is a perspective view of a seat frame for a vehicle seat according to one embodiment of the present invention. [Figure 2] This is a side view of a vehicle seat, seen from the left. [Figure 3] This is a rear view of a vehicle seat, seen from behind. [Figure 4] This is a perspective view showing a disassembled view of the structure around the upper hook. [Figure 5](a) is a perspective view of the first fixing bracket from the front, and (b) is a perspective view showing the structure around the upper hook. [Figure 6] This is a perspective view showing the fixing wire and the second fixing bracket. [Figure 7] Figure 7(a) shows a disassembled perspective view of the connecting bracket and wire, Figure 7(a) shows section II (b), and Figure 7(a) shows the view from arrow II (c). [Figure 8] This is a top-down plan view of a vehicle seat. [Figure 9] This is a cross-sectional view from the front of the connecting bracket, showing the area near the opening cut by a plane perpendicular to the front-to-back direction. [Figure 10] This is a perspective view showing the right-side back frame disassembled. [Figure 11] This is a cross-sectional view taken along line III-III in Figure 10. [Figure 12] This is a perspective view of the left side back frame, seen from the right. [Figure 13] This is a perspective view of the intermediate bracket from the left. [Figure 14] This is a perspective view showing a modified example of the pressure-receiving member. [Figure 15] This is a perspective view showing a modified version of the reclining bracket. [Figure 16] This is a rear view showing a modified example of the auxiliary bracket. [Modes for carrying out the invention]

[0037] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings as appropriate. As shown in Figure 1, the vehicle seat according to the first embodiment is configured as, for example, a vehicle seat S installed in an automobile. The vehicle seat S is constructed by covering a seat frame F that constitutes the frame of the vehicle seat S with a pad made of a cushioning material such as urethane foam and a surface material made of synthetic leather or fabric.

[0038] The seat frame F comprises a seat cushion frame F1 and a seat back frame F2. In this specification, the front-to-back, left-to-right, and up-and-down directions are based on the occupant seated in the vehicle seat S.

[0039] The seat cushion frame F1 is a component that makes up the frame of the seat cushion. The seat back frame F2 is a component that makes up the frame of the seat back.

[0040] The seat cushion frame F1 is installed on the floor of the vehicle via a left-right sliding mechanism M1 and a front-back sliding mechanism M2. This allows the seat frame F to move forward, backward, left, and right relative to the floor. The seat back frame F2 is rotatably connected at its lower end to the rear of the seat cushion frame F1 via a reclining unit RU. This allows the seat back frame F2 to tilt forward and backward relative to the seat cushion frame F1.

[0041] The seat cushion frame F1 mainly comprises left and right cushion side frames F11, a front frame F12 connecting the left and right cushion side frames F11, a rear frame F13 and connecting bracket 10, and a pressure receiving member 20. The left and right cushion side frames F11 extend in the front-rear direction. The front frame F12 is a pipe-shaped frame and connects the front parts of the left and right cushion side frames F11. The rear frame F13 is a pipe-shaped frame and connects the rear parts of the left and right cushion side frames F11.

[0042] The connecting bracket 10 is positioned between the front frame F12 and the rear frame F13 in the front-rear direction. In the front-rear direction, the distance from the connecting bracket 10 to the front frame F12 is less than the distance from the connecting bracket 10 to the rear frame F13. The left and right ends of the connecting bracket 10 are welded to the left and right cushion side frames F11. The structure of the connecting bracket 10 will be described in detail later.

[0043] The pressure-receiving member 20 is a member that supports the occupant and has a plurality of pressure-receiving wires 21 and a pressure-receiving plate 22. Three of the plurality of pressure-receiving wires 21 extend in the front-rear direction and are supported by the front frame F12 and the rear frame F13. These three pressure-receiving wires 21 are positioned above the connecting bracket 10.

[0044] One of the multiple pressure-receiving wires 21 extends in the left-right direction and is supported by the left and right cushion side frames F11. The pressure-receiving plate 22 is fixed to three pressure-receiving wires 21 that extend in the front-rear direction. The pressure-receiving plate 22 is positioned in the front-rear direction between the connecting bracket 10 and the pressure-receiving wires 21 that extend in the left-right direction.

[0045] The left-right sliding mechanism M1 is a mechanism that supports the seat cushion frame F1 so that it can move in the left-right direction. The left-right sliding mechanism M1 is positioned between the seat cushion frame F1 and the front-rear sliding mechanism M2 in the vertical direction.

[0046] As shown in Figure 2, the left-right sliding mechanism M1 comprises a pair of front and rear upper rails M11 that support the seat cushion frame F1, and a pair of front and rear lower rails M12 that slidably support the upper rails M11. The front upper rail M11 is positioned below the connecting bracket 10 and fixed to the connecting bracket 10. The rear upper rail M11 is fixed to the left and right cushion side frames F11 or to members fixed to the left and right cushion side frames F11.

[0047] The front-to-back sliding mechanism M2 is a mechanism that supports the seat cushion frame F1 and the left-to-right sliding mechanism M1 so that they can move in the front-to-back direction. The front-to-back sliding mechanism M2 is located below the left-to-right sliding mechanism M1. The front-to-back sliding mechanism M2 includes a front-to-back moving member M21 that moves in the front-to-back direction together with the seat cushion frame F1 and the left-to-right sliding mechanism M1, and a support rail M22 that supports the front-to-back moving member M21 so that it can move in the front-to-back direction. One front-to-back moving member M21 and one support rail M22 are each located on the left and right sides of the seat cushion frame F1 (see Figure 1).

[0048] The longitudinal movement member M21 is a support member that supports the seat cushion frame F1 via the left-right sliding mechanism M1. The lower rails M12 of the left-right sliding mechanism M11 are fixed to the upper end of the longitudinal movement member M21.

[0049] A contact member TM is attached to the front end M211 of the longitudinal moving member M21, which can contact the support rail M22 when the seat frame F is tilted forward. The contact member TM extends downward from the front end M211 of the longitudinal moving member M21. The lower end of the contact member TM is bent into a U shape in cross-section.

[0050] More specifically, the lower end of the contact member TM is bent forward and then bent upward. As shown in Figure 1, a notch TM1 is formed in the center of the left-right direction of the lower end of each contact member TM. As a result, the bent lower ends of the contact members TM are arranged side by side.

[0051] As shown in Figure 2, the vehicle seat S is further equipped with an upper hook 30 and a lower hook 40, which have a cross-sectional shape J-shaped and engage with each other when an excessive load is applied to the seat frame F or the vehicle body in the longitudinal direction. The upper hook 30 is provided at the rear of the seat cushion frame F1, and the lower hook 40 is provided at the rear of the longitudinal moving member M21.

[0052] More specifically, the upper hook 30 is fixed to the first fixing bracket B1, which is fixed to the rear frame F13. The upper hook 30 protrudes below the lower surface of the seat cushion frame F1, more specifically below the upper surface M212 that supports the lower rail M12 of the longitudinal moving member M21. The lower hook 40 is fixed to the rear end of the longitudinal moving member M21. The lower hook 40 protrudes above the upper surface M212 of the longitudinal moving member M21.

[0053] As shown in Figure 3, there are multiple first fixing brackets B1 and upper hooks 30, specifically two, spaced apart from each other on the left and right. The lower hooks 40 extend continuously in the left-right direction, encompassing the area where the two upper hooks 30 are located. More specifically, the left-right length of the lower hooks 40 is greater than the distance from the left end of the left upper hook 30 to the right end of the right upper hook 30.

[0054] As shown in Figure 4, the upper hook 30 has a first base portion 31 extending in the vertical direction, a U-shaped first bent portion 32 that is bent upward from the lower end of the first base portion 31, and a first tip portion 33 that extends upward from the upper end of the first bent portion 32. The first base portion 31 has two holes 31A through which a screw SC passes at its upper end. The two holes 31A are spaced apart in the left-right direction. The screw SC is a screw for fixing the upper hook 30 to the first fixing bracket B1. When the first base portion 31 is fixed to the first fixing bracket B1 with the screw SC, it extends downward from the first fixing bracket B1. Specifically, as shown in Figure 2, when the upper hook 30 is fixed to the seat cushion frame F1, the first base portion 31 extends downward from the seat cushion frame F1.

[0055] As shown in Figure 4, the first base portion 31 has a Y-shaped bead BD1 that protrudes to the rear. The bead BD1 has a first linear portion BD11 that extends vertically, a second linear portion BD12 that extends diagonally downward to the left from the lower end of the first linear portion BD11, and a third linear portion BD13 that extends diagonally downward to the right from the lower end of the first linear portion BD11.

[0056] The first linear portion BD11 is positioned between the two holes 31A. The second linear portion BD12 is positioned below the left hole 31A. The third linear portion BD13 is positioned below the right hole 31A.

[0057] The lower hook 40 has a second base portion 41 extending substantially vertically, a U-shaped second bent portion 42 that is bent downward from the upper end of the second base portion 41, and a second tip portion 43 that extends downward from the lower end of the second bent portion 42. The second base portion 41 has a shape that conforms to the rear surface shape of the front-rear moving member M21 and has a plurality of bent portions 41A. The second base portion 41 has a hole 41B at its lower end through which a screw (not shown) passes. The screw is used to fix the lower hook 40 to the front-rear moving member M21.

[0058] As shown in Figure 3, the holes 41B are formed at the left and right ends of the second base portion 41, respectively. As shown in Figure 2, when the lower hook 40 is fixed to the front-rear moving member M21, the second base portion 41 extends upward from the front-rear moving member M21.

[0059] As shown in Figure 4, the first fixed bracket B1 includes a first base wall B11 and a first peripheral wall portion B12 rising from the periphery of the first base wall B11. The first base wall B11 is a substantially rectangular plate-shaped wall. The first base wall B11 has three holes H1 spaced apart in the left-right direction.

[0060] The first periphery wall B12 is formed along the entire periphery of the first base wall B11 and has a plurality of bent portions B13 that are bent along the periphery of the first base wall B11. The first periphery wall B12 has a front wall B14, a left wall B15, a right wall B16, and a rear wall B17 located at the front end, left end, right end, and rear end of the first base wall B11, respectively. The front wall B14, left wall B15, right wall B16, and rear wall B17 are each connected via the bent portions B13.

[0061] The amount of protrusion of the front wall B14 from the first base wall B11 is smaller than the amount of protrusion of the left wall B15, right wall B16, and rear wall B17 from the first base wall B11. The left wall B15 and the right wall B16 are formed symmetrically. As shown in Figure 5(b), the left wall B15 and the right wall B16 have arc-shaped recesses D1 at their upper ends that contact the outer surface of the rear frame F13. With each recess D1 in contact with the rear frame F13, the upper ends of the left wall B15 and the right wall B16 are joined to the rear frame F13 by welding.

[0062] As shown in Figure 5(a), the rear wall B17 has three holes H2 arranged in the left-right direction. The two rightmost holes H2 are mounting holes for attaching the upper hook 30 (see Figure 5(b)). Specifically, screws SC are fastened into the two rightmost holes H2.

[0063] Two beads BD2 are formed on the first base wall B11 and the rear wall B17, extending from the first base wall B11 to the rear wall B17. Each bead BD2 is spaced apart in a predetermined direction, specifically in the left-right direction. Each bead BD2 protrudes from the top surface of the first base wall B11 and the front surface of the rear wall B17. The middle of the three holes H2 is positioned between the two beads BD2 in the left-right direction. Specifically, one bead BD2 is positioned between the right hole H2 and the middle hole H2, and the other bead BD2 is positioned between the left hole H2 and the middle hole H2.

[0064] Furthermore, the left bead BD2 is positioned in the front-to-back direction, spaced apart from the leftmost hole H1 of the three. The right bead BD2 is positioned in the left-to-right direction, between the leftmost hole H1 and the rightmost hole H1.

[0065] As shown in Figure 5(b), with the upper hook 30 fixed to the seat cushion frame F1 and the lower hook 40 fixed to the front-rear moving member M21, the first tip portion 33 of the upper hook 30 is positioned between the second base portion 41 and the second tip portion 43 of the lower hook 40, with a gap between them in the front-rear direction (see also Figure 2).

[0066] As shown in Figure 3, a second fixing bracket B2, to which a fixing wire W1 is attached, is fixed to each of the left and right ends of the rear frame F13. The fixing wire W1 is a wire used to secure the child seat to the seat cushion frame F1.

[0067] As shown in Figure 6, the fixing wire W1 is bent into a U-shape, and each end W11 is welded to the second fixing bracket B2, thereby fixing it to the second fixing bracket B2. The second fixing bracket B2 includes a second base wall B21 and a second peripheral wall portion B22 that rises from the periphery of the second base wall B21. The second base wall B21 is a roughly rectangular plate-shaped wall.

[0068] The second base wall B21 has a flat plate portion B211 extending diagonally upward and forward from the rear frame F13, and an arc-shaped curved portion B212 extending from the rear end of the flat plate portion B211 along the outer circumferential surface of the rear frame F13. The flat plate portion B211 has two holes H3 spaced apart in the left-right direction. The two holes H3 are positioned between the ends W11 of the fixing wire W1 in the left-right direction. The curved portion B212 overlaps with the rear frame F13 so as to cover a part of the outer circumferential surface of the rear frame F13. A recess D3 is formed at the rear end of the curved portion B212.

[0069] The second periphery wall B22 is formed along the entire periphery of the second base wall B21 and has a plurality of bent portions B23 that are bent along the periphery of the second base wall B21. The second periphery wall B22 has a front wall B24, left wall B25, right wall B26, and rear wall B27 located at the front end, left end, right end, and rear end of the second base wall B21, respectively. The front wall B24, left wall B25, right wall B26, and rear wall B27 are each connected via the bent portions B23.

[0070] The left wall B25 and the right wall B26 have arc-shaped recesses D2 at their lower ends that contact the outer surface of the rear frame F13. Each recess D2 is joined to the rear frame F13 by welding.

[0071] As shown in Figures 7(a) to 7(c), the aforementioned connecting bracket 10 has two opposing walls 11 and 12 that face each other in the extending direction of the cushion side frame F11, i.e., in the front-rear direction, a connecting wall 13 that connects the two opposing walls 11 and 12, and bent portions 14 and 15 that are provided at the ends of the two opposing walls 11 and 12 opposite to the connecting wall 13 and are bent in a U-shape in cross-section. In this embodiment, each opposing wall 11 and 12 extends upward from the connecting wall 13.

[0072] At the left and right ends of the connecting wall 13, inclined walls 16 and 17 are provided, which are inclined relative to the connecting wall 13. The inclined walls 16 and 17 are located at the rear end of the connecting wall 13 and are connected to the connecting wall 13 and the opposing wall 12 at the rear.

[0073] The connecting wall 13 has an opening 13A in the center in the left-right direction. The opening 13A is formed as a rectangular hole that is elongated in the left-right direction. The connecting wall 13 has beads 13B between both ends and the opening 13A in the left-right direction.

[0074] Two beads 13B are provided side by side in the front-to-back direction on the right end of the connecting wall 13, and two more are provided side by side in the front-to-back direction on the left end of the connecting wall 13 (see also Figure 8). Each bead 13B extends in the left-to-right direction.

[0075] The connecting wall 13 has three holes H4 on both the left and right sides of the opening 13A. Of the three holes H4 on the right side, the rightmost hole H4 is located between the right end of the connecting wall 13 and the bead 13B in the left-right direction. Of the three holes H4 on the right side, the two leftmost holes H4 are located between the bead 13B and the opening 13A in the left-right direction. Of the six holes H4, a predetermined hole H4 is a hole through which a screw SC for fastening the upper rail M11 to the connecting bracket 10 passes (see Figure 8).

[0076] A U-shaped wire W2 is provided at the front end of the connecting wall 13. The wire W2 is long in the left-right direction and is adjacent to the opposing wall 11 on the front side. One end of the wire W2 is welded to the right end of the opposing wall 11, and the other end is welded to the left end of the opposing wall 11. The wire W2 is also welded below the pressure-receiving member 20, supporting the pressure-receiving member 20 from below.

[0077] The height of the two opposing walls 11 and 12 from the connecting wall 13 at their left-right ends is greater than the height from the connecting wall 13 at the center in the left-right direction. Specifically, the upper end of the front opposing wall 11 is highest at the left-right end, slopes downwards as it moves inward from the left-right end, and then extends along the left-right direction towards the center. Similarly, the upper end of the rear opposing wall 12 is highest at the left-right end, slopes downwards as it moves inward from the left-right end, and connects to the connecting wall 13. In other words, the rear opposing wall 12 does not exist in the left-right center of the connecting wall 13, and the height of the rear opposing wall 12 in the left-right center is 0. At the left-right center of the rear end of the connecting wall 13 where the rear opposing wall 12 is absent, a bent portion 15 is formed, as shown in Figure 7(b). In the left-right center of the connecting wall 13, the rear bent portion 15 is positioned lower than the upper end of the front bent portion 14.

[0078] The upper end of the wire W2 is positioned above the center of each opposing wall 11, 12 in the left-right direction. This prevents the pressure-receiving member 20 from moving too far downward, as it will come into contact with the wire W2 (see Figure 1).

[0079] The front bent portion 14 is formed to fold back from the opposing wall 11 towards the front. The rear bent portion 15 is formed to fold back from the opposing wall 12 towards the rear.

[0080] As shown in Figures 8 and 9, the front upper rail M11 of the left-right sliding mechanism M1 is fixed to the connecting bracket 10 and the cushion side frame F11 by a number of screws SC. The front upper rail M11 is provided with a locking mechanism M3 that locks the upper rail M11 to the lower rail M12. The locking mechanism M3 is located within the opening 13A of the connecting bracket 10. The locking mechanism M3 protrudes above the connecting wall 13 of the connecting bracket 10.

[0081] As shown in Figure 1, the seat back frame F2 mainly comprises a right back side frame F21, a left back side frame F22, a pipe frame P1 and reinforcing pipe P2 connecting the left and right back side frames F21 and F22, and left and right armrest mechanisms M4. The right back side frame F21 is rotatably supported at the rear end of the right cushion side frame F11 via the right reclining unit RU. Between the left back side frame F21 and the left cushion side frame F11, there is an intermediate bracket B3 that supports a spring SP that biases the seat back frame F2 forward. The intermediate bracket B3 is fixed to the rear end of the left cushion side frame F11 and rotatably supports the left back side frame F21.

[0082] The armrest mechanism M4 comprises an arm frame M41 that constitutes the frame of the armrest, and a support mechanism M42 that rotatably supports the arm frame M41. The support mechanism M42 is fixed to the left and right backside frames F21 and F22, respectively.

[0083] As shown in Figures 1 and 3, the pipe frame P1 has a first portion P11 extending in the left-right direction, a second portion P12 extending downward from the left end of the first portion P11, and a third portion P13 extending from the lower end of the second portion P12 toward the right backside frame F21. The right end of the first portion P11 bends diagonally downward from the center in the left-right direction, then extends to the right and is welded to the upper end of the right backside frame F21. The first portion P11 has two flat portions P111 which become flat when crushed in the front-rear direction. Each flat portion P111 is provided with two headrest mounting members AT for attaching the headrest to the pipe frame P1.

[0084] The second section P12 bends diagonally downward to the left from the left end of the first section P11, and then extends downward along the left backside frame F22. The third section P13 is bent at approximately 90 degrees relative to the second section P12, and its right end is welded to the right backside frame F21.

[0085] A cover member B4 is provided at the upper right corner of the seat back frame F2. The cover member B4 is welded to the right back side frame F21 and the first part P11, covering the joint between the upper end of the right back side frame F21 and the first part P11. The cover member B4 has a box shape consisting of a base wall with an L-shaped cross-section that is bent to follow the first part P11 and the back side frame F21, and a peripheral wall portion that rises from the periphery of the base wall and has multiple bent portions that are bent along the periphery of the base wall. A resin seat guide (not shown) that guides the seat belt and has a seat belt outlet formed therein is fixed to the upper surface of the cover member B4.

[0086] The reinforcing pipe P2 is positioned vertically between the first section P11 and the third section P13 of the pipe frame P1. The reinforcing pipe P2 has a first pipe section P21 extending to the left from the right backside frame F21, a second pipe section P22 extending diagonally to the left and rear from the left end of the first pipe section P21 (see also Figure 8), a third pipe section P23 extending to the left from the left end of the second pipe section P22, and a fourth pipe section P24 extending downwards, bent at approximately 90 degrees from the third pipe section P23. In other words, the upper part of the fourth pipe section P24 is adjacent to the left backside frame F22 and is bent downwards from the third pipe section P23.

[0087] The first pipe section P21 is joined to the right-side back frame F21 by welding. The fourth pipe section P24 is joined to the second part P12 of the pipe frame P1 by welding.

[0088] The right rear side frame F21 is provided with a retractor mounting bracket 50 and an auxiliary bracket B5 to which a retractor for winding up the seat belt is attached. The retractor mounting bracket 50 is located behind the reinforcing pipe P2. The retractor mounting bracket 50 has third side walls 51, 52 that face each other in the left-right direction, and a third bottom wall 53 that connects the two third side walls 51, 52.

[0089] Each of the third side walls 51 and 52 extends forward from the left and right ends of the third bottom wall 53. The right third side wall 51 is welded to the right backside frame F21. The left third side wall 52 is welded to the third pipe section P23 of the reinforcing pipe P2. Therefore, the bent portion of the reinforcing pipe P2 between the second pipe section P22 and the third pipe section P23 is located in front of the retractor mounting bracket 50 and is bent forward.

[0090] A mounting member 54 for attaching the retractor to the third bottom wall 53 is welded to the third bottom wall 53. As a result, a joint where the mounting member 54 is joined to the third bottom wall 53 is formed as a weld mark WP. In each drawing, areas with an oval outline that are filled in black or have dot hatching all represent weld marks.

[0091] The third bottom wall 53 has a rearward-projecting annular bead 53A and multiple linear beads 53B formed thereon. The annular bead 53A surrounds the weld mark WP, which is the joint. The multiple linear beads 53B are located on the left and right sides of the annular bead 53A, respectively. The multiple linear beads 53B on the left extend to the left from the annular bead 53A and wrap around to the left third side wall 52. The multiple linear beads 53B on the right extend to the right from the annular bead 53A and wrap around to the right third side wall 51.

[0092] The auxiliary bracket B5 has two side walls B51 that face each other in the left-right direction, and a bottom wall B52 that connects the two side walls B51. The right side wall B51 is welded to the right back side frame F21.

[0093] As shown in Figure 10, the right-side back frame F21 has a hollow frame FM with a rectangular closed cross-section and a reclining bracket 60. The hollow frame FM is composed of a first frame 70 and a second frame 80, which are U-shaped in cross-section.

[0094] The first frame 70 has two first side walls 71 and 72 that face each other in the front-rear direction, and a first bottom wall 73 that connects the two first side walls 71 and 72. The second frame 80 has two second side walls 81 and 82 that face each other in the front-rear direction, and a second bottom wall 83 that connects the two second side walls 81 and 82, and a second bottom wall 83 that faces the first bottom wall 73 in the left-right direction. Here, the front-rear direction is an example of the first direction, and the left-right direction is an example of the second direction.

[0095] The first frame 70 and the second frame 80 are identical parts molded using the same mold. The hollow frame FM is constructed by reversing one of the two identical parts and combining them. When the first frame 70 and the second frame 80 are combined, the front first side wall 72 and the front second side wall 81 overlap, and the rear first side wall 71 and the rear second side wall 82 overlap. Since the first frame 70 and the second frame 80 are identical parts, the following description will refer to each part of the first frame 70. For each part of the second frame 80, "2nd" will be added to the beginning of the part name, and the end of the reference numeral will be the same as the corresponding part of the first frame 70, and the description will be omitted.

[0096] The edge E1 of the rear first side wall 71, opposite to the first bottom wall 73, has multiple, specifically three, protruding shapes 71A. The edge E1 has a first protruding edge portion E11 and a first base edge portion E12. The first protruding edge portion E11 is the tip of the protruding shape 71A and is joined to the rear second side wall 82 by welding. The first base edge portion E12 is the edge portion closer to the first bottom wall 73 than the first protruding edge portion E11 and is joined to the rear second side wall 82 by welding. As a result, as shown in Figure 3, the multiple weld marks WP joining the rear first side wall 71 and the rear second side wall 82 are arranged in a staggered pattern. Specifically, the weld marks WP joining the first protruding edge portion E11 and the weld marks WP joining the first base edge portion E12 are located at different positions in the left-right direction.

[0097] Returning to Figure 10, the front second side wall 81 has an edge E2, a protruding shape 81A, a second protruding edge E21, and a second base edge E22, which have the same structure as the edge E1, protruding shape 71A, first protruding edge portion E11, and first base edge portion E12 of the rear first side wall 71 described above. The edge E2 of the front second side wall 81 is joined to the front first side wall 72 by weld marks arranged in a staggered pattern.

[0098] The edge of the front first side wall 72 opposite to the first bottom wall 73 does not have a protruding shape, but extends vertically along the first bottom wall 73. The rear second side wall 82 has the same structure as the front first side wall 72.

[0099] The first bottom wall 73 has two first recesses 73A, a semicircular recess 73B, and two first protrusions 73C. Each first recess 73A and semicircular recess 73B is recessed toward the second bottom wall 83. Each first protrusion 73C protrudes away from the second bottom wall 83. The semicircular recess 73B is formed at the upper end of the first bottom wall 73. A semicircular notch H11 is formed at the bottom of the semicircular recess 73B to support the end of the first part P11 of the pipe frame P1.

[0100] Each first recess 73A is provided at intervals along the longitudinal direction, i.e., the vertical direction, of the first frame 70. Specifically, the upper first recess 73A is provided approximately in the center of the first bottom wall 73 in the vertical direction, and the lower first recess 73A is provided at the lower end of the first bottom wall 73. A hole H12 is formed at the bottom of the upper first recess 73A through which the first pipe portion P21 of the reinforcing pipe P2 passes. A hole H13 is formed at the bottom of the lower first recess 73A through which the third portion P13 of the pipe frame P1 passes.

[0101] The two first protrusions 73C are positioned between the two first recesses 73A in the vertical direction. The two first protrusions 73C extend in the vertical direction and are spaced apart in the front-rear direction. In the front-rear direction, the distance between the front first protrusion 73C and the front first side wall 72 is smaller than the distance between the two first protrusions 73C. In the front-rear direction, the distance between the rear first protrusion 73C and the rear first side wall 71 is smaller than the distance between the two first protrusions 73C.

[0102] The second bottom wall 83 has a second recess 83A, a semicircular recess 83B, a second protrusion 83C, a notch H21, and holes H22, H23, which have the same structure as the first recess 73A, semicircular recess 73B, first protrusion 73C, notch H11, and holes H12, H13 of the first bottom wall 73 described above. When the first frame 70 and the second frame 80 are joined together, as shown in Figure 11, each first recess 73A and each second recess 83A are facing each other in the left-right direction.

[0103] Returning to Figure 10, the first portion P11 of the pipe frame P1 is welded to the hollow frame FM while being supported by the respective notches H11 and H21 of the hollow frame FM. The third portion P13 of the pipe frame P1 is welded to the hollow frame FM while being inserted into the respective holes H13 and H23 of the hollow frame FM (see Figure 11). The first pipe portion P21 of the reinforcing pipe P2 is welded to the hollow frame FM while being inserted into the respective holes H12 and H22 of the hollow frame FM. The joint portion (contacting portion) of the armrest mechanism M4 and the hollow frame FM is located in the vertical direction between the upper recesses 73A and 83A and the lower recesses 73A and 83A. A portion of the joint portion of the armrest mechanism M4 and the hollow frame FM is located within the range of the first protrusion 73C in the vertical direction.

[0104] The reclining bracket 60 is a bracket that is rotatably supported by the reclining unit RU and is welded to the lower end of the hollow frame FM. The reclining bracket 60 has a bottom wall 61 and two side walls 62, 63 extending to the right from each front-rear end of the bottom wall 61.

[0105] The bottom wall 61 has a hole H31 through which the third part P13 of the pipe frame P1 passes, and a plurality of annularly arranged holes H32 for attaching the reclining unit RU. The holes H32 are arc-shaped holes centered on the pivot axis of the back side frame F21. The two side walls 62 and 63 sandwich the hollow frame FM in the front-to-back direction.

[0106] As shown in Figure 12, the left backside frame F22 is formed in a front-to-back symmetrical shape. The left backside frame F22 has a base wall 221 and a peripheral wall portion 222 that rises from the periphery of the base wall 221. The peripheral wall portion 222 protrudes to the right from the base wall 221. The upper end of the base wall 221 gradually decreases in width in the front-to-back direction as it goes upwards. The upper end of the backside frame F22 is formed in a U-shape in cross-section along the outer circumferential surface of the second portion P12 of the pipe frame P1.

[0107] The base wall 221 has two third recesses 221A and an X-shaped bead BD3. The two third recesses 221A are recessed to the right from the base wall 221. The two third recesses 221A are aligned horizontally on either side of the second portion P12. The two third recesses 221A are positioned above the vertical center of the back side frame F22.

[0108] The bead BD3 is formed by four recesses D4 formed in the base wall 221. The bead BD3 protrudes to the left from the bottom of the recesses D4. The bead BD3 is located below the third recess 221A, more specifically at the bottom of the base wall 221.

[0109] The second portion P12 of the pipe frame P1 is joined to the backside frame F22 by welding, in contact with the upper end of the U-shaped cross-section of the backside frame F22, each of the third recesses 221A, and the base wall 221. The third portion P13 of the pipe frame P1 is positioned within the range of the bead BD3 in the vertical direction. As shown in Figure 2, the weld mark WP, which is the joint between the armrest mechanism M4 and the backside frame F22, is positioned between the upper end of the third recess 221A and the lower end of the bead BD3 in the vertical direction.

[0110] As shown in Figure 13, the intermediate bracket B3 supporting the left reclining unit RU has a base wall B31 and a peripheral wall portion B32 rising from the periphery of the base wall B31. The base wall B31 has a wire support portion B311 that supports a wire for operating the reclining unit RU. The wire support portion B311 is formed by cutting and bending a part of the base wall B31. The wire support portion B311 and the peripheral wall portion B32 protrude to the left from the base wall B31.

[0111] The vehicle seat S of this embodiment, as described above, can achieve the following effects. As shown in Figure 3, the multiple weld marks WP, which are the joints between the first side wall 71 on the rear side of the first frame 70 and the second side wall 82 on the rear side of the second frame 80, are positioned at different locations in the left-right direction. This improves the joint strength of the first frame 70 and the second frame 80. Furthermore, since the front sides of the first frame 70 and the second frame 80 have the same structure, a similar effect can be achieved.

[0112] As shown in Figure 10, by aligning the first recess 73A provided in the first bottom wall 73 of the first frame 70 and the second recess 83A provided in the second bottom wall 83 of the second frame 80 with each other in the left-right direction, the rigidity of the hollow frame FM against external forces applied from the left-right direction can be improved.

[0113] By positioning the first protrusion 73C between the two first recesses 73A, the rigidity of the first frame 70 can be further improved. The same effect can be achieved with the second frame 80, which has the same structure as the first frame 70.

[0114] By forming holes H13 and H23 in the first recess 73A and the second recess 83A, and joining the third portion P13 to the hollow frame FM while it is inserted into the holes H13 and H23, the assembly work of the hollow frame FM and the pipe frame P1 can be facilitated while improving the joint strength between the hollow frame FM and the pipe frame P1.

[0115] By forming multiple holes H32 arranged in an annular pattern in the reclining bracket 60, the reclining unit RU can be stably attached to the reclining bracket 60 while suppressing an increase in the weight of the reclining bracket 60.

[0116] As shown in Figure 3, by joining the first portion P11 of the pipe frame P1 to the upper end of the hollow frame FM, covering the joint between the hollow frame FM and the first portion P11 with a cover member B4, and joining the cover member B4 to the hollow frame FM and the first portion P11, the rigidity of the upper corner portion of the seat back frame F2 can be improved.

[0117] By providing an annular bead 53A and a linear bead 53B on the retractor mounting bracket 50 to which the retractor is attached, the rigidity of the retractor mounting bracket 50 can be improved, thereby enabling the retractor to be stably supported by the retractor mounting bracket 50.

[0118] As shown in Figure 1, by bending the reinforcing pipe P2 to which the retractor mounting bracket 50 is joined, the rigidity of the reinforcing pipe P2 can be improved, so that the retractor can be stably supported by the retractor mounting bracket 50 and the reinforcing pipe P2.

[0119] The pipe frame P1 has a third part P13 that extends from the lower end of the second part P12 toward the right back side frame F21 and is joined to the right back side frame F21, thereby improving the rigidity of the seat back frame F2 while suppressing an increase in the number of parts.

[0120] As shown in Figure 12, the connection strength between the left backside frame F22 and the pipe frame P1 can be improved by sandwiching the second portion P12 of the pipe frame P1 between the two third recesses 221A of the left backside frame F22. In addition, the rigidity of the left backside frame F22 can be improved by forming an X-shaped bead BD3 on the left backside frame F22.

[0121] As shown in Figure 7, the connecting bracket 10 has a U-shaped section formed by the two opposing walls 11 and 12 and the connecting wall 13, and further U-shaped bent sections 14 and 15 are formed in the section, thereby improving the rigidity of the connecting bracket 10.

[0122] Since inclined walls 16 and 17 are provided at the left and right ends of the connecting wall 13, the rigidity of the left and right ends of the connecting bracket 10 can be improved.

[0123] By providing an opening 13A in the center of the connecting wall 13 in the left-right direction, the locking mechanism M3 (see Figure 8) can be placed within this opening 13A. This makes it possible to suppress the increase in the vertical size of the vehicle seat S compared to a structure in which, for example, the locking mechanism is placed separately below the connecting bracket.

[0124] Since beads 13B are provided between the left and right ends of the connecting wall 13 and the opening 13A, the rigidity around the opening 13A of the connecting bracket 10 can be improved.

[0125] By making the height of the left and right ends of the opposing walls 11 and 12 greater than that of the central part, the contact area between the opposing walls 11 and 12 and the cushion side frame F11 can be increased, thereby improving the joint strength between the opposing walls 11 and 12 and the cushion side frame F11. In addition, because the height of the central part of the opposing walls 11 and 12 in the left and right directions is small, the vertical movement of the pressure receiving member 20 can be prevented from being obstructed by the connecting bracket 10.

[0126] As shown in Figure 2, the left-right sliding mechanism M1 is positioned below the connecting bracket 10, and the highly rigid connecting bracket 10 is supported by the left-right sliding mechanism M1, so that the seat cushion frame F1 can be stably slid left and right.

[0127] By positioning the front-to-back sliding mechanism M2 below the left-to-right sliding mechanism M1, and supporting the highly rigid connecting bracket 10 via the left-to-right sliding mechanism M1 and the front-to-back sliding mechanism M2, the seat cushion frame F1 can be stably slid back and forth.

[0128] As shown in Figure 1, since the pressure-receiving member 20 is positioned above the connecting bracket 10, the rigid connecting bracket 10 can restrict the excessive downward movement of the pressure-receiving member 20.

[0129] As shown in Figure 2, the seat cushion frame F1 is provided with an upper hook 30 that has a J-shape in cross-section, and the front-rear moving member M21 is provided with a lower hook 40 that has a J-shape in cross-section. When an excessive force is applied to the seat cushion frame F1 in the front-rear direction and the seat cushion frame F1 attempts to move relative to the front-rear moving member M21, the upper hook 30 and the lower hook 40 engage with each other, thereby preventing the seat cushion frame F1 from shifting significantly away from the front-rear moving member M21.

[0130] By providing a lower hook 40 on the forward / backward moving member M21, which moves in the forward / backward direction together with the seat cushion frame F1, the relative front-to-back position of each hook 30, 40 does not change even when the seat cushion frame F1 is slid back and forth. Therefore, even if an excessive force is applied to the seat cushion frame F1 in the forward / backward direction, each hook 30, 40 can be properly engaged.

[0131] By providing a contact member TM extending downward from the front end M211 of the longitudinal movement member M21, the contact member TM comes into contact with the support rail M22 when the vehicle seat S tilts forward, thereby preventing the vehicle seat S from tilting excessively forward.

[0132] By bending the lower end of the contact member TM, the rigidity of the contact member TM can be improved, thereby better suppressing excessive forward tilting of the vehicle seat S.

[0133] By forming a notch in the center of the lower end of the contact member TM in the left-right direction, when the vehicle seat S is tilted forward, each end of the lower end of the contact member TM in the left-right direction comes into contact with the support rail M22, allowing the contact member TM to distribute the load evenly.

[0134] Since multiple upper hooks 30 are provided on the left and right sides with gaps in between, the load can be distributed and supported to both sides.

[0135] Since the lower hook 40 is formed to extend continuously in the left-right direction, including the area where the multiple upper hooks 30 are arranged, the seat cushion frame F1 can be slid smoothly from side to side without the hooks 30 and 40 interfering with each other.

[0136] As shown in Figure 5, by fixing the upper hook 30 to the box-shaped first fixing bracket B1 which includes the first base wall B11 and the first peripheral wall portion B12, the rigidity around the upper hook 30 of the seat cushion frame F1 can be improved.

[0137] Since the hole H2 for attaching the upper hook 30 is positioned between the two beads BD2, the rigidity of the portion of the first fixing bracket B1 to which the upper hook 30 is attached can be improved.

[0138] As shown in Figure 6, by fixing the fixing wire W1 for securing the child seat to the box-shaped second fixing bracket B2 which includes the second base wall B21 and the second peripheral wall B22, the load of the child seat applied to the fixing wire W1 is transmitted to the rear frame F13 via the box-shaped second fixing bracket B2, thereby providing stable support for the child seat.

[0139] By forming a recess D3 in the portion of the second fixing bracket B2 that overlaps with the rear frame F13, the mounting rigidity between the second fixing bracket B2 and the rear frame F13 can be improved.

[0140] Although embodiments of the present invention have been described above, the present invention can be implemented by modifying it as appropriate, as shown in the following other embodiments. In the following description, components that are substantially the same as those in the above embodiments will be denoted by the same reference numerals, and their descriptions will be omitted.

[0141] The pressure-receiving member is not limited to the pressure-receiving member 20 of the above embodiment, but may be a plate-shaped pan frame PF as shown in Figure 14, for example. The pan frame PF has two inner recesses D5, two outer recesses D6, two front recesses D7, a central recess D8, and four rear recesses D9. Each recess D5 to D9 is elongated in the front-to-back direction and recessed downwards.

[0142] The two inner recesses D5 are positioned symmetrically with respect to the left-right center of the pan frame PF. At the bottom of each inner recess D5, two holes H5 are formed, spaced apart in the front-to-back direction.

[0143] Each outer recess D6 is positioned further outward in the left-right direction than the two inner recesses D5. More specifically, one of the two outer recesses D6 is positioned to the left of the two inner recesses D5, and the other outer recess D6 is positioned to the right of the two inner recesses D5. The depth of the outer recesses D6 is greater than the depth of the inner recesses D5. The outer recesses D6 are also larger than the inner recesses D5 in the front-to-back direction. Two holes H6 are formed at the bottom of each outer recess D6, spaced apart in the front-to-back direction. Clips for securing harnesses and the like to the bottom of the pan frame PF are engaged with the holes H6.

[0144] The two front recesses D7 are positioned in front of the inner recess D5. A long, horizontal hole H7 is formed at the bottom of the front recesses D7.

[0145] The central recess D8 extends from between the two front recesses D7 to between the two inner recesses D5. The width of the central recess D8 in the lateral direction is smaller than the width of each recess D5-D7 in the lateral direction.

[0146] The four rear recesses D9 are spaced apart from each other in the left-right direction. Two of the four rear recesses D9 are located behind each inner recess D5. The two rear recesses D9 on the left and the two rear recesses D9 on the right are arranged symmetrically with respect to the left-right center of the pan frame PF.

[0147] In this configuration, the depth of the outer recess D6 formed in the plate-shaped pan frame PF is made greater than the depth of the inner recess D5, thereby improving the rigidity of the pan frame PF and enabling better support of the occupant, thus improving ride comfort. Furthermore, because the outer recess D6 is deep, the clip engaged with the hole H6 is prevented from digging into the pad placed on top of the pan frame PF, thus reducing discomfort to the occupant's buttocks.

[0148] The reclining bracket is not limited to the reclining bracket 60 of the above embodiment, but may also be a reclining bracket B6 as shown in Figure 15, for example. The reclining bracket B6 has a bottom wall B61 and two side walls B62 and B63 extending to the left from each end of the bottom wall B61 in the front-rear direction. In the example in Figure 15, the hollow frame FM and the reclining bracket B6 are applied to the left back side frame.

[0149] The bottom wall B61 has a plurality of annularly arranged holes H61 and a rectangular hole H62 for mounting the reclining unit RU. Holes H61 are round. Hole H62 is formed spanning the bottom wall B61 and the side wall B63. The front edge E1 of the first frame 70 and the front second side wall 82 and second bottom wall 83 of the second frame 80 are exposed within hole H62. The exposed edge E1 and second side wall 82 within hole H62 are joined by a weld mark WP1. The rear edge of hole H62 and the second bottom wall 83 of the second frame 80 are joined by a weld mark WP2.

[0150] In this configuration, the front edge E1 of the first frame 70 and the front second side wall 82 and second bottom wall 83 of the second frame 80 are exposed within the hole H62. Therefore, the three components, the first frame 70, the second frame 80, and the reclining bracket B6, can be joined together by welding while assembled.

[0151] The auxiliary bracket is not limited to the auxiliary bracket B5 of the above embodiment, but may also be an auxiliary bracket B7 as shown in Figure 16, for example. The auxiliary bracket B7 has a base wall B71 and a peripheral wall portion B72 that rises from the periphery of the base wall B71. The auxiliary bracket B7 is joined to the first portion P11 of the pipe frame P1 and the hollow frame FM by welding. This further improves the rigidity of the auxiliary bracket B7, so that the retractor can be supported more stably.

[0152] In the above embodiment, a hollow frame was applied to the back side frame, but the present invention is not limited thereto, and the hollow frame may also be applied to, for example, the cushion side frame.

[0153] In the above embodiment, the number of protruding shapes of the first frame was set to 3, but the present invention is not limited thereto, and the number of protruding shapes may be 2 or 4 or more.

[0154] In the above embodiment, the side frame to which the connecting bracket is connected is a cushion side frame, but the present invention is not limited thereto, and the side frame may be, for example, a back side frame.

[0155] In the above embodiment, each bent portion of the connecting bracket was formed to be folded back in a direction away from each other, but the present invention is not limited thereto, and each bent portion may be formed to be folded back in a direction toward each other.

[0156] In the above embodiment, inclined walls were provided at both the left and right ends of the connecting bracket, but the present invention is not limited thereto, and the inclined walls may be provided only at either the left or right end of the connecting bracket.

[0157] The support member that supports the seat cushion frame is not limited to a member that moves forward and backward. For example, in a vehicle seat structure where the seat does not move forward and backward, a member that does not move forward and backward may be used as the support member.

[0158] The number of upper hooks may be one or three or more. The number of lower hooks may also be multiple.

[0159] In a box-shaped bracket having a base wall and a peripheral wall, the peripheral wall does not necessarily have to be formed along the entire periphery of the base wall. Furthermore, the peripheral wall only needs to have at least one bent portion.

[0160] In the above embodiment, the first direction was the front-to-back direction and the second direction was the left-to-right direction, but the present invention is not limited thereto. For example, when a hollow frame is applied to a seat cushion frame, the first direction may be the up-and-down direction and the second direction may be the left-to-right direction.

[0161] In the above embodiment, a vehicle seat S used in an automobile was given as an example of a vehicle seat, but the present invention is not limited thereto and can also be applied to other vehicle seats, such as seats used in ships and aircraft. Furthermore, the vehicle seat S according to the above embodiment may have a left-right inverted structure.

[0162] The elements described in the above embodiments and modifications may be implemented in any combination. [Explanation of symbols]

[0163] 70. First Frame 71,72 First side wall 71A Protruding shape 73. First bottom wall 80 2nd Frame 81,82 Second side wall 83. Second bottom wall E1 edge E11 1st protruding edge E12 First base edge FM Hollow Frame S Vehicle Seat

Claims

1. It comprises a first frame and a second frame, which have a U-shaped cross-section, forming a hollow frame with a closed cross-section. The first frame mentioned above is, Two first side walls facing each other in the first direction, It has a first bottom wall connecting the two first side walls, The previous second frame was, Two second side walls facing each other in the first direction, A second bottom wall connecting the two aforementioned second side walls, the second bottom wall having a second side wall facing the first bottom wall in a second direction, The edge of the first side wall opposite to the first bottom wall is It has multiple protruding shapes, The tip of the aforementioned protruding shape, having a first protruding edge that is joined to one of the second side walls, It has a first base edge that is closer to the first bottom wall than the first protruding edge and is joined to one of the second side walls, The weld marks joining the first protruding edge and the second side wall, and the weld marks joining the first base edge and the second side wall are arranged at different positions in the second direction. A retractor mounting bracket to which a retractor for retracting a seat belt is attached, further comprising a retractor mounting bracket joined to the hollow frame, The aforementioned retractor mounting bracket is Third side walls that face each other in the left-right direction, A third bottom wall connecting the two aforementioned third side walls, An annular bead formed on the third bottom wall, the annular bead surrounding the joint between the mounting member for attaching the retractor to the third bottom wall and the third bottom wall, A vehicle seat characterized by having a linear bead that extends from the annular bead in the left-right direction and wraps around to the third side wall.

2. The first bottom wall has a first recess, The second bottom wall has a second recess, The vehicle seat according to claim 1, characterized in that the first recess and the second recess face each other in the second direction.

3. The first recess is recessed toward the second bottom wall, and two of them are provided spaced apart in the longitudinal direction of the first frame. The vehicle seat according to claim 2, characterized in that the first bottom wall has a first convex portion that protrudes in a direction away from the second bottom wall, and the first convex portion is located between the two first recesses in the longitudinal direction of the first frame.

4. The aforementioned hollow frame is one of the left or right side frames of the seat back frame. The aforementioned vehicle seat is A pipe frame having a first portion that extends in the left-right direction and is joined to the upper end of the hollow frame, The vehicle seat according to claim 2, further comprising a cover member that covers the joint between the upper end of the hollow frame and the first portion, and is joined to the hollow frame and the first portion.

5. A reinforcing pipe connecting the hollow frame and the other left and right side frames, further comprising a reinforcing pipe positioned in front of the retractor mounting bracket and joined to the retractor mounting bracket, The vehicle seat according to claim 4, characterized in that the reinforcing pipe has a portion located in front of the retractor mounting bracket that is bent forward, and a portion adjacent to the other side frame that is bent downward.

6. The vehicle seat according to claim 4, further comprising a reclining bracket having a plurality of holes arranged in an annular shape for attaching a reclining unit that tilts the seat back frame, the reclining bracket being joined to the lower end of the hollow frame.

7. The pipe frame has a second portion that extends downward from the end of the first portion opposite to the hollow frame, The other side frames on the left and right are, Two third recesses sandwiching the second portion, A vehicle seat according to any one of claims 4 to 6, characterized by having an X-shaped bead positioned below the third recess.

8. The seat for a vehicle according to claim 7, characterized in that the pipe frame is formed in a U shape, having a third portion that extends from the lower end of the second portion toward the hollow frame and is joined to the hollow frame.

9. The first recess and the second recess each have a hole through which the third portion passes, The vehicle seat according to claim 8, characterized in that the third portion is joined to the hollow frame while inside the hole.

Images