Mounting structure for back frame in vehicle seat, vehicle seat, and back frame of vehicle seat

Abstract

To facilitate insertion of lower end parts of left and right side frames of a back frame to a connection space of a support bracket.SOLUTION: A structure for fitting a back frame into a vehicular seat comprises: a support bracket 25 made of metal in which an upper end is open and a connection space is formed therein; and a back frame made of resin having side frames 50 of which lower end parts 59 are inserted from above to the connection space 36 of the support bracket. The lower end part of the side frame comprises two parts 57 to be fixed that are fixed respectively at two places of the support bracket and mutually separated in a front and rear direction. When a straight line passing the two parts to be fixed is defined as a reference line SL2, a distance LB between one specification part 55R that is a portion of a lower edge part 55 of the side frame, and the reference line is longer than a distance LF between a site excluding the specification part of the lower edge part, and the reference line.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an attachment structure of a back frame in a vehicle seat, a vehicle seat, and a back frame of a vehicle seat.

Background Art

[0002] Patent Document 1 below discloses a vehicle seat. This vehicle seat includes a pair of left and right reclining mechanisms (reclining devices) connected to a cushion frame, and a pair of left and right metal support brackets (connecting brackets) connected to the left and right reclining mechanisms. The cross-sectional shape of the left and right support brackets is substantially U-shaped. That is, the support bracket has a base portion (main body wall portion), a front flange (front wall portion) and a rear flange (rear wall portion) that respectively project from the front edge portion and the rear edge portion of the base portion in a direction orthogonal to the base portion. The space surrounded by the base portion, the front flange and the rear flange is the connection space.

[0003] Furthermore, this vehicle seat includes a resin back frame. The back frame includes a pair of left and right side frames. The lower end portion of each side frame is inserted into the connection space of the corresponding support bracket from above, and the left and right lower end portions and the left and right support brackets are fixed by a fixing member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The above vehicle seat has room for improvement in making it easier to insert the lower end portions of the left and right side frames of the back frame into the connection space of the support brackets.

[0006] In consideration of the above facts, the present invention aims to provide a mounting structure for a back frame in a vehicle seat, a vehicle seat, and a back frame for a vehicle seat, which allow the lower ends of the left and right side frames of the back frame to be easily inserted into the connection space of the support bracket. [Means for solving the problem]

[0007] The mounting structure for the back frame of a vehicle seat according to claim 1 is: It has a front flange and a rear flange located behind the front flange, and between the front flange and the rear flange The top end is open. Connect It comprises a pair of left and right metal support brackets that form a space and are connected to a cushion frame, and a resin back frame having a pair of left and right side frames whose lower ends are inserted from above into the connection space of the left and right support brackets, When the lower end of the side frame is brought close to the support bracket from above, the lower edge of the side frame contacts the upper end of the front flange or the upper end of the rear flange, and the lower end can be inserted into the connection space. The lower end of the side frame is fixed to two locations on the support bracket, and has two fixed parts that are separated from each other in the front-to-back direction. When the side frame is viewed in the left-to-right direction, the straight line passing through the two fixed parts is defined as the reference line. The lower edge portion The orthogonal distance between a specific part of the lower edge and the reference line, perpendicular to the reference line, is longer than the orthogonal distance between the portion of the lower edge excluding the specific part and the reference line.

[0008] The resin back frame of claim 1 comprises a pair of left and right side frames. Here, a structure in which the entire lower edge of the side frame is parallel to the reference line, and a structure in which the orthogonal distance between multiple parts of the lower edge of the side frame and the reference line is longer than the orthogonal distance between the parts of the lower edge excluding the multiple parts and the reference line are referred to as the comparative structure. The orthogonal distance between one specific part, which is part of the lower edge of each side frame of claim 1, and the reference line is longer than the orthogonal distance between the parts of the lower edge excluding the specific part and the reference line. Therefore, the lower end of the side frame of claim 1 can be inserted more easily into the connection space of the corresponding support bracket than the lower end of the side frame of the comparative structure.

[0009] The mounting structure for a back frame in a vehicle seat according to claim 2 is the mounting structure for a back frame in a vehicle seat according to claim 1, wherein the front end or rear end of the lower edge is the specified part.

[0010] The lower end of the side frame according to claim 2 can be inserted more easily into the connection space of the corresponding support bracket than the lower end of the side frame of the comparative structure.

[0011] The mounting structure for the back frame in a vehicle seat according to claim 3 is the mounting structure for the back frame in a vehicle seat according to claim 2, wherein the lower edge of the side frame is in a straight line shape that is inclined with respect to the reference line when the side frame is viewed in the left-right direction.

[0012] The lower edge of the side frame according to claim 3 has a straight shape that is inclined with respect to the reference line when viewing the seat back frame in the left-right direction. Therefore, the lower end of the side frame according to claim 3 can be easily inserted into the connection space of the corresponding support bracket.

[0013] The mounting structure for a back frame in a vehicle seat according to claim 4 is the mounting structure for a back frame in a vehicle seat according to claim 2 or claim 3, wherein the fixed portion comprises a first fixed portion and a second fixed portion located behind the first fixed portion, and the orthogonal distance between the specific portion which is the rear end of the lower edge and the reference line is longer than the orthogonal distance between the front end of the lower edge and the reference line.

[0014] When a rear-end collision occurs in a vehicle equipped with the mounting structure for the back frame of the vehicle seat described in claim 4, a rearward force is applied to the back frame from the back of the occupant seated in the vehicle seat, and a rearward force is also applied from the back frame to the first fixed part and the second fixed part. At this time, the force applied to the second fixed part tends to be greater than the force applied to the first fixed part. However, the area of ​​the rear part of the lower end of the back frame of claim 4 is larger than the area of ​​the front part of the lower end. Therefore, the lower end of the back frame is less likely to be damaged by the force applied to the second fixed part.

[0015] The mounting structure for a back frame in a vehicle seat according to claim 5 is the mounting structure for a back frame in a vehicle seat according to claim 1 or claim 2, wherein the support bracket has an opposing portion that faces the lower end in the left-right direction when the lower end is fixed to the support bracket, and a pressing member that is fixed to the side of the lower end opposite to the opposing portion and sandwiches the lower end between itself and the opposing portion.

[0016] According to claim 5, the support bracket and the lower end of the side frame are firmly fixed to each other.

[0017] The mounting structure for a back frame in a vehicle seat according to claim 6 is the mounting structure for a back frame in a vehicle seat according to claim 1 or claim 2, wherein a fixed member is fixed to the support bracket, the lower end is fixed to the support bracket when the relative position of the support bracket and the lower end is at a predetermined position, and a stopper portion is provided on the side frame that contacts the upper end of the fixed member from above when the relative position of the support bracket and the lower end is at the predetermined position.

[0018] When the relative position between the support bracket of claim 6 and the lower end of the side frame reaches a predetermined position, the stopper portion of the side frame contacts the upper end portion of the member to be fixed from above. Therefore, an operator performing the connection work between the support bracket and the side frame can recognize that the relative position between the support bracket and the lower end of the side frame has reached the predetermined position.

[0019] The vehicle seat according to the invention of claim 7 includes the attachment structure of the back frame in the vehicle seat according to claim 1 or claim 2.

[0020] The back frame of the vehicle seat according to the invention of claim 8 is It has a front flange and a rear flange located behind the front flange, and between the front flange and the rear flange with an open upper end Connect a back frame having a pair of left and right side frames, the lower end portions of which are inserted into the connection space of the metal support bracket in which a space is formed, from above, When the lower end of the side frame is brought close to the support bracket from above, the lower edge of the side frame contacts the upper end of the front flange or the upper end of the rear flange, and the lower end can be inserted into the connection space. the lower end portions of the side frames are respectively fixed to two locations of the support bracket and include two fixed portions that are separated from each other in the front-rear direction, and when a straight line passing through the two fixed portions when viewing the side frames in the left-right direction is defined as a reference line, The lower edge portion the distance in the orthogonal direction perpendicular to the reference line between one specific portion that is a part of the side frame and the reference line is longer than the distance in the orthogonal direction between the portion excluding the specific portion of the lower edge portion and the reference line.

Effect of the Invention

[0021] As described above, according to the attachment structure of the back frame, the vehicle seat, and the back frame of the vehicle seat according to the present invention, the lower end portions of the left and right side frames of the back frame can be easily inserted into the connection space of the support bracket.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic side view showing a vehicle seat and a floor surface of a vehicle according to an embodiment of the present invention. [Figure 2]It is a perspective view when looking from the front at a back frame, a support bracket, a reclining mechanism, and peripheral members thereof. [Figure 3] It is an exploded perspective view when looking from the front at a back frame, a support bracket, and a connecting member. [Figure 4] It is an exploded perspective view of the lower part of the right back frame, a support bracket, and a nut. [Figure 5] It is a rear view of a back frame and a connecting member. [Figure 6] It is a rear view of a separated state between a back frame and a connecting member. [Figure 7] It is a side view of a separated state of the lower part of the right back frame and a support bracket. [Figure 8] It is a side view of an assembled state of the lower part of the right back frame and a support bracket. [Figure 9] It is a side view similar to FIG. 7 when the center lines of the lower part of the right back frame and the support bracket are displaced from each other. [Figure 10] It is a side view similar to FIG. 9 when the rear end portion of the lower flange of the right back frame enters the connection space. [Figure 11] It is a schematic cross-sectional view along the arrow line 11-11 in FIG. 2. [Figure 12] It is a schematic side view of the lower part of the right back frame and a support bracket of Comparative Example 1. [Figure 13] It is a schematic side view of the lower part of the right back frame and a support bracket of Comparative Example 2. [Figure 14] It is a schematic side view of the lower part of the right back frame of the first modification example. [Figure 15] It is a schematic side view of the lower part of the right back frame of the second modification example. [Figure 16] It is a schematic side view of the lower part of the right back frame of the third modification example.

Modes for Carrying Out the Invention

[0023] Hereinafter, a vehicle seat 10 (hereinafter referred to as seat 10) according to an embodiment of the present invention will be described with reference to the attached drawings. In each figure, arrows FR indicate the front direction of the vehicle, arrows UP indicate the upward direction of the vehicle, and arrows LH indicate the left side in the left-right direction (vehicle width direction) of the vehicle. Hereafter, when simply referring to the front-rear, left-right, and up-down directions, these refer to the front-rear direction of the vehicle, the left-right direction in the left-right direction (vehicle width direction) of the vehicle, and the up-down direction of the vehicle.

[0024] The seat 10 shown in Figure 1 is installed on the floor 101 of the passenger compartment of the vehicle 100. The seat 10 comprises a seat cushion 11, a seat back 45 whose lower end is rotatably connected to the rear end of the seat cushion 11, and a headrest 78.

[0025] The seat cushion 11 has a metal cushion frame 15 as a skeletal member and a first cushion member (not shown) that surrounds the cushion frame 15. The cushion frame 15 has a pair of left and right side frames 16, a rear frame (not shown) that connects the rear ends of the left and right side frames 16, and a front frame (not shown) that connects the front ends of the left and right side frames 16. A support member 19 is provided on the floor surface 101. The support member 19 is, for example, a slide rail device.

[0026] As shown in Figures 1 to 5, a well-known reclining mechanism 20 is provided at the rear ends of the left and right side frames 16. The left and right reclining mechanisms 20 have a base plate and a ratchet plate that are rotatable relative to each other around a rotation axis extending in the left-right direction. The base plate is fixed to the rear end of the side frame 16. The left and right reclining mechanisms 20 are linked to each other via a connecting shaft 23 extending in the left-right direction. As will be described later, each reclining mechanism 20 can be switched between a locked state and an unlocked state.

[0027] A metal support bracket 25 is fixed to the ratchet plate of each reclining mechanism 20. As shown in Figure 7, the support bracket 25 is substantially symmetrical with respect to the center line CL25. The support bracket 25 has opposing portions 26 and an outer peripheral flange 31. The opposing portion 26 is a plate-shaped portion substantially perpendicular to the left-right direction. The lower part of the outer surface of the opposing portion 26 is fixed to the left and right ratchet plates. A pair of front and rear upper end protrusions 27 are provided at the upper end of the opposing portion 26. Furthermore, each upper end protrusion 27 is provided with a through hole 28. Furthermore, a shaft through hole 29 is provided at the lower part of the opposing portion 26. As shown in Figure 2, the vicinity of the left end of the connecting shaft 23 rotatably passes through the shaft through hole 29 of the left support bracket 25, and the vicinity of the right end of the connecting shaft 23 rotatably passes through the shaft through hole 29 of the right support bracket 25.

[0028] Furthermore, outer peripheral flanges 31 are provided on the outer peripheral edges of the opposing portion 26, excluding the upper edge. The outer peripheral flange 31 of the left support bracket 25 protrudes to the right from the opposing portion 26, and the outer peripheral flange 31 of the right support bracket 25 protrudes to the left from the opposing portion 26. The outer peripheral flange 31 has a front flange 32 provided on the front edge of the opposing portion 26, a rear flange 33 provided on the rear edge of the opposing portion 26, and a lower flange 34 provided on the lower edge of the opposing portion 26. The side shapes of the front flange 32 and the rear flange 33 are substantially straight. As shown in Figure 7, the distance in the front-rear direction between the upper ends of the front flange 32 and the rear flange 33 is longer than the distance in the front-rear direction between the lower ends of the front flange 32 and the rear flange 33. The side shape of the lower flange 34 is substantially arc-shaped. Furthermore, the space enclosed by the opposing portion 26 and the outer peripheral flange 31 constitutes a connection space 36.

[0029] Here, as shown in Figures 7, 9, and 10, the straight line passing through the upper end of the front flange 32 and the upper end of the rear flange 33 in a side view is defined as the first reference line SL1.

[0030] As shown in Figures 2, 3, 5, and 6, a metal connecting member 38 is provided between the left and right support brackets 25. The connecting member 38 has connecting ends (fixed members) 39 provided at both the left and right ends, and a straight portion 40 that connects the left and right connecting ends 39. The front shape of the connecting ends 39 is approximately triangular.

[0031] As shown in Figure 2, the left reclining mechanism 20 is rotatably provided with an operating lever 24. When the operating lever 24 is in the initial position (position in Figure 2), each reclining mechanism 20 is locked, and relative rotation between the base plate and the ratchet plate is restricted. Therefore, relative rotation of the left and right support brackets 25 and connecting members 38 with respect to the side frame 16 (seat cushion 11) is restricted. When the operating lever 24 is rotated from the initial position to the operating position (not shown), each reclining mechanism 20 is unlocked, and relative rotation between the base plate and the ratchet plate is permitted. Therefore, relative rotation of the left and right support brackets 25 and connecting members 38 with respect to the side frame 16 is permitted.

[0032] The seat back 45 has a back frame 46, which is a single molded resin part serving as a skeletal component, and a second cushioning member (not shown) that surrounds the back frame 46. The back frame 46 has an upper frame 47 extending in the left-right direction, and a pair of left and right side frames 50 extending downward from both ends of the upper frame 47. The back frame 46 is symmetrical.

[0033] The side frame 50 has a base 51 and an outer peripheral flange 52. The base 51 is a plate-shaped portion that is substantially perpendicular to the left-right direction. The outer peripheral flange 52 is provided on the outer peripheral edge of the base 51, excluding the upper edge. The outer peripheral flange 52 of the left side frame 50 protrudes to the right from the base 51, and the outer peripheral flange 52 of the right side frame 50 protrudes to the left from the base 51. The outer peripheral flange 52 has a front flange 53 provided on the front edge of the base 51, a rear flange 54 provided on the rear edge of the base 51, and a lower flange (lower edge portion) 55 provided on the lower edge of the base 51. The side shape of the front flange 53 and the rear flange 54 is substantially arc-shaped. The side shape of the lower flange 55 is linear. This "linear shape" includes both a perfectly linear shape and a substantially linear shape. As shown in Figure 4, a front through hole (fixed part) (first fixed part) 57 and a rear through hole (fixed part) (second fixed part) 57 are formed near the lower end of the base 51. Here, as shown in Figures 7 to 10, the straight line passing through the front and rear through holes 57 in a side view is defined as the second reference line SL2. In this case, the lower flange 55 is inclined with respect to the second reference line SL2 in a side view. That is, if the direction perpendicular to the second reference line SL2 is defined as the orthogonal direction, then, as shown in Figure 7, the orthogonal distance LB from the second reference line SL2 to the rear end (specific part) 55R of the lower flange 55 is longer than the orthogonal distance LF from the second reference line SL2 to the front end 55F of the lower flange 55. Furthermore, as shown in Figures 5 and 6, a roughly U-shaped projection 58 is formed on the inner peripheral edge of the rear surface of the back frame 46, and the left and right lower ends of the projection 58 each constitute roughly triangular stopper parts 58A.

[0034] As shown in Figures 4 and 7 to 10, the area between the portion of the side frame 50 located a predetermined distance above the through hole 57 and the lower flange 55 is the lower end portion 59 of the side frame 50. In other words, as will be described later, when the side frame 50 and the support bracket 25 are fixed by nuts (retaining members) 60, 61 and bolts 70, 72, the area of ​​the side frame 50 that faces the opposing portion 26 in the left-right direction is the lower end portion 59. The side shape of the lower end portion 59 is substantially the same as the connection space 36 of the support bracket 25.

[0035] Each side frame 50 is manufactured by insert molding, which is performed with a pair of metal nuts 60 and 61 installed inside a mold (not shown). As shown in Figures 7 to 11, the metal nuts 60 and 61 are integrated with the inner surface of the lower end portion 59 of the side frame 50. The side shape of the nuts 60 and 61 is approximately rectangular, and the nuts 60 and 61 are fixed to the inner surface of the base portion 51. Furthermore, nut 61 is located behind nut 60. The female threaded holes 62 and through holes 57 of nuts 60 and 61 are coaxial with each other.

[0036] When connecting the back frame 46 to the left and right support brackets 25, as shown in Figure 7, first the lower flange 55 of each side frame 50 is positioned directly above the upper end opening of the corresponding support bracket 25. Next, each side frame 50 is moved downward so that its lower end 59 is inserted into the connection space 36 of the corresponding support bracket 25. At this time, as shown in Figure 7, in a side view, the first reference line SL1 and the second reference line SL2 are approximately parallel, and the lower flange 55 is inclined with respect to the first reference line SL1 and the second reference line SL2. Once the lower end 59 has entered the connection space 36 and the relative position of the lower end 59 and the support bracket 25 is at the predetermined position shown in Figure 8, the stopper portion 58A of each side frame 50 contacts the upper end of the corresponding connection end 39 from above, as shown in Figure 5. As a result, the left and right side frames 50 can no longer move downward relative to the support bracket 25. Furthermore, when the relative position of the lower end portion 59 and the support bracket 25 reaches the predetermined position, the front and rear through holes 28 of the support bracket 25 and the front and rear through holes 57 of the lower end portion 59 become coaxial with each other. In addition, the outer surface of the base portion 51 contacts the inner surface of the opposing portion 26, the front surface of the front flange 53 contacts the rear surface of the front flange 32, and the rear surface of the rear flange 54 contacts the front surface of the rear flange 33.

[0037] In this state, the bolt 70 (see Figure 3) located on the outside of each support bracket 25 is inserted into the front through hole 57, and the bolt 72 is inserted into the rear through hole 57. Furthermore, the bolt 70 is inserted into the female threaded hole 62 of the nut 60, and the head 71 of the bolt 70 is pressed against the outer surface of the base 51. Furthermore, the bolt 72 is inserted into the female threaded hole 62 of the nut 61, and the head 73 of the bolt 72 is pressed against the outer surface of the base 51. This fixes the lower end 59 of each side frame 50 to the corresponding support bracket 25.

[0038] Next, the first cushion member is placed over the cushion frame 15, and the second cushion member is placed over the back frame 46. Furthermore, the surface of the first cushion member is covered with the upholstery material 75 (see Figure 1), and the surface of the second cushion member is covered with the upholstery material 76 (see Figure 1). Finally, the headrest 78 (see Figure 1) is connected to the upper end of the seat back 45. This completes the seat 10 shown in Figure 1.

[0039] Next, the operation and effects of this embodiment will be described.

[0040] Figure 12 shows Comparative Example 1 of the present invention. The support bracket 25 of Comparative Example 1 has the same structure as the support bracket 25 of the embodiment. On the other hand, the lower flange 55A of the side frame 50A of Comparative Example 1 is parallel to the second reference line SL2. In Comparative Example 1, when the lower end 59 is moved downward while the center line CL25 passing through the center of the support bracket 25 in the front-rear direction and the center line CL59A passing through the center of the lower end 59 of the side frame 50A in the front-rear direction are misaligned in the direction of the first reference line SL1, the lower flange 55A collides with the upper end surface of the front flange 32 or rear flange 33 of the support bracket 25. That is, in this case, the lower end 59 cannot enter the connection space 36 of the support bracket 25.

[0041] Figure 13 shows Comparative Example 2 of the present invention. The support bracket 25 of Comparative Example 2 has the same structure as the support bracket 25 of the embodiment. On the other hand, the lower end portion 59 of the side frame 50B of Comparative Example 2 has a pair of front and rear lower end protrusions 55B1. That is, the orthogonal distance LC from the second reference line SL2 to the lower edge of each lower end protrusion 55B1 is longer than the orthogonal distance LD from the second reference line SL2 to the center of the lower flange 55B. In Comparative Example 2, when the lower end portion 59 is moved downward while the center line CL25 of the support bracket 25 and the center line CL59B passing through the center in the front-rear direction of the lower end portion 59 of the side frame 50B are misaligned in the direction of the first reference line SL1, the lower edge (lower flange 55B) of one of the lower end protrusions 55B1 collides with the upper end surface of the front flange 32 or the rear flange 33. That is, in this case, the lower end portion 59 cannot enter the connection space 36 of the support bracket 25.

[0042] Thus, inserting the side frame 50A of Comparative Example 1 and the side frame 50B of Comparative Example 2 into the connection space 36 of the support bracket 25 is not easy.

[0043] In contrast, in this embodiment, the orthogonal distance LB from the second reference line SL2 to the rear end 55R of the lower flange 55 is longer than the orthogonal distance LF from the second reference line SL2 to the front end 55F. That is, in a side view, the lower flange 55 is inclined with respect to the second reference line SL2 (and the first reference line SL1). Therefore, as shown in Figure 7, when the position of the center line CL25 of the support bracket 25 and the position of the center line CL59 passing through the center of the lower end 59 of the side frame 50 in the front-rear direction in the direction of the first reference line SL1 coincide, moving the lower end 59 downwards allows the lower end 59 to smoothly enter the connection space 36 of the support bracket 25, as shown in Figure 8.

[0044] As shown in Figure 9, when the lower end portion 59 is moved downward while the center line CL59 is misaligned with respect to the center line CL25 in the direction of the first reference line SL1, the rear end portion 55R enters the connection space 36 of the support bracket 25, as shown in Figure 10. If the lower end portion 59 is moved further downward in this state, a part of the lower flange 55 comes into contact with the upper end of the front flange 32. If the lower end portion 59 is moved further downward in this state, the lower flange 55 is guided by the upper end of the front flange 32, causing the side frame 50 to move rearward (downward and rearward) relative to the support bracket 25. As a result, as shown in Figure 8, the front flange 32 smoothly enters the connection space 36 of the support bracket 25.

[0045] Thus, in this embodiment, whether the positions of the center line CL59 and the center line CL25 in the direction of the first reference line SL1 coincide or are misaligned, the lower ends 59 of the left and right side frames 50 can be easily inserted into the connection space 36 of the corresponding support bracket 25.

[0046] Furthermore, if a rear-end collision occurs in a vehicle equipped with the seat 10 of this embodiment, a rearward force is applied to the back frame 46 from the back of the occupant P1 seated in the seat 10, and a rearward force is also applied to the bolts 70 and 72 from the front and rear through holes 57 of the left and right side frames 50. At this time, the force applied to bolt 72 tends to be greater than the force applied to bolt 70. In addition, a force is applied from bolt 72 to the rear of the lower end portion 59. However, as is clear from Figure 8, the area of ​​the rear of the lower end portion 59 is larger than the area of ​​the front of the lower end portion 59. Therefore, there is little risk of the lower end portion 59 (side frame 50) being damaged by the force applied from bolt 72 to the lower end portion 59.

[0047] Furthermore, as shown in Figure 11, the lower end 59 of the side frame 50 is sandwiched in the left-right direction by nuts 60 and 61 fixed to the inner surface of the lower end 59 and the opposing portion 26 of the support bracket 25. Thus, the support bracket 25 and the lower end 59 are firmly fixed to each other.

[0048] Furthermore, when the lower end portion 59 enters the connection space 36 and the relative position of the lower end portion 59 and the support bracket 25 reaches the predetermined position shown in Figure 8, the stopper portion 58A of each side frame 50 contacts the upper end of the corresponding connection end portion 39 from above. Therefore, an operator performing the connection work between the side frame 50 and the support bracket 25 can recognize that the relative position of the support bracket 25 and the lower end portion 59 has reached the predetermined position. In other words, the operator can recognize that the front and rear through holes 28 of the support bracket 25 and the front and rear through holes 57 of the lower end portion 59 are coaxial with each other, without visually inspecting the support bracket 25 and the side frame 50. Thus, the operator can easily perform the connection work between the support bracket 25 and the side frame 50.

[0049] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

[0050] For example, the present invention may be implemented in the form of the first modified example shown in Figure 14. In a side view, the lower flange 55 of the side frame 80 in the first modified example is inclined with respect to the second reference line SL2. Furthermore, in a side view, the orthogonal distance LF from the second reference line SL2 to the front end (specific part) 55F of the lower flange 55 is longer than the orthogonal distance LB from the second reference line SL2 to the rear end 55R of the lower flange 55. In the first modified example as well, the lower end 59 of each side frame 80 can be easily inserted into the connection space 36 of the corresponding support bracket 25.

[0051] The present invention may also be implemented in the form of the second modified example shown in Figure 15. In a side view, the shape of the side frame 85 in the second modified example changes in a stepped manner. That is, a lower end protrusion (specific part) 86 is provided at the rear of the lower end portion 59, which is located lower than the front portion. In the second modified example as well, the lower end portion 59 of each side frame 85 can be easily inserted into the connection space 36 of the corresponding support bracket 25.

[0052] Although not shown in the diagram, the lower end projection 86 may be provided at the front of the lower end 59 instead of the rear.

[0053] The present invention may also be implemented in the manner of the third modified example shown in Figure 16. In a side view, the lower flange 55 of the side frame 90 in the third modified example is substantially V-shaped. That is, in a side view, the orthogonal distance LM from the second reference line SL2 to the central part (specific part) 55M of the lower flange 55 in the front-rear direction is longer than the orthogonal distance LF from the second reference line SL2 to the front end 55F of the lower flange 55 and the orthogonal distance LB from the second reference line SL2 to the rear end 55R of the lower flange 55. In the third modified example as well, the lower end 59 of each side frame 90 can be easily inserted into the connection space 36 of the corresponding support bracket 25.

[0054] The side frames 50, 80, 85, and 90 may be fixed to the support bracket 25 using fixing members other than bolts 70 and 72. For example, the lower ends 59 of the side frames 50, 80, 85, and 90 may be fixed to the support bracket 25 using two rivets (fixing members) that pass through two parts (fixed parts) of the lower ends 59 of the side frames 50, 80, 85, and 90 and two parts of the opposing parts 26 of the support bracket 25. Alternatively, the two parts (fixed parts) of the lower ends 59 of the side frames 50, 80, 85, and 90 and the two parts of the opposing parts 26 of the support bracket 25 may be fixed using adhesive (fixing member).

[0055] Furthermore, the lower ends 59 of the side frames 50, 80, 85, and 90 and the support brackets 25 may be fixed by three or more fixing members. In this case, the second reference line SL2 is a straight line passing through any two of the parts of the lower end 59 where the three fixing members are provided (fixed parts).

[0056] The reclining mechanism 20 may be omitted from the seat 10, and the support bracket 25 may be fixed to the side frame 16 (cushion frame 15). That is, instead of connecting the support bracket 25 to the side frame 16 via the reclining mechanism 20, the support bracket 25 may be connected directly to the side frame 16. [Explanation of symbols]

[0057] 10. Vehicle seats (seats) 15 Cushion Frame 25 Support bracket 26 Opposing part 36 Connection Spaces 39 Connection end (fixed member) 46 Backframe 50 50A 50B Side Frame 55 55A 55B Lower flange (lower edge) 55F Front end (specific part) 55R rear end (specific part) 55M center part (specific part) 57 Through hole (fixed part) (first fixed part) (second fixed part) 58A Stopper section 59 Lower end 60 61 Nut (retaining member) 86 Lower end protrusion (specific part) SL2 Second Reference Line (Reference Line)

Claims

1. A pair of left and right metal support brackets having a front flange and a rear flange located behind the front flange, with a connecting space formed between the front flange and the rear flange having an open upper end, and connected to a cushion frame, A resin back frame having a pair of left and right side frames whose lower ends are inserted from above into the connection space of the left and right support brackets, Equipped with, When the lower end of the side frame is brought close to the support bracket from above, the lower edge of the side frame contacts the upper end of the front flange or the upper end of the rear flange, and the lower end can be inserted into the connection space. The lower end of the side frame is fixed to two locations on the support bracket, and has two fixed parts that are separated from each other in the front-to-back direction. A mounting structure for a back frame in a vehicle seat, wherein, when the side frame is viewed in the left-right direction, a straight line passing through the two fixed parts is defined as the reference line, and the orthogonal distance perpendicular to the reference line between a specific part which is part of the lower edge of the side frame and the reference line is longer than the orthogonal distance between the part of the lower edge excluding the specific part and the reference line.

2. The mounting structure for a back frame in a vehicle seat according to claim 1, wherein the front end or rear end of the lower edge is the specified part.

3. The mounting structure for a back frame in a vehicle seat according to claim 2, wherein the lower edge of the side frame has a straight shape that is inclined with respect to the reference line when the side frame is viewed in the left-right direction.

4. The fixed portion comprises a first fixed portion and a second fixed portion located rearward of the first fixed portion. The mounting structure for a back frame in a vehicle seat according to claim 2 or 3, wherein the orthogonal distance between the specific portion which is the rear end of the lower edge and the reference line is longer than the orthogonal distance between the front end of the lower edge and the reference line.

5. The support bracket has a portion that faces the lower end in the left-right direction when the lower end is fixed to the support bracket, A mounting structure for a back frame in a vehicle seat according to claim 1 or claim 2, comprising a retaining member fixed to the surface of the lower end opposite to the opposing portion, which sandwiches the lower end between itself and the opposing portion.

6. The fixed member is provided, which is fixed to the support bracket. The lower end is fixed to the support bracket when the relative position of the support bracket and the lower end is at a predetermined position. A mounting structure for a back frame in a vehicle seat according to claim 1 or 2, wherein a stopper portion is provided on the side frame that contacts the upper end of the fixed member from above when the relative position of the support bracket and the lower end is at the predetermined position.

7. A vehicle seat comprising a mounting structure for a back frame in a vehicle seat according to claim 1 or claim 2.

8. A back frame having a pair of left and right side frames, the lower end of which is inserted from above into the connection space of a metal support bracket having a front flange and a rear flange located behind the front flange, the connection space having an upper end opening between the front flange and the rear flange, When the lower end of the side frame is brought close to the support bracket from above, the lower edge of the side frame contacts the upper end of the front flange or the upper end of the rear flange, and the lower end can be inserted into the connection space. The lower end of the side frame is fixed to two locations on the support bracket, and has two fixed parts that are separated from each other in the front-to-back direction. A back frame for a vehicle seat, in which, when the side frame is viewed in the left-right direction, a straight line passing through the two fixed portions is defined as the reference line, and the orthogonal distance perpendicular to the reference line between a specific portion which is part of the lower edge of the side frame and the reference line is longer than the orthogonal distance between the portion of the lower edge excluding the specific portion and the reference line.

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