JP5708211B2 - Seat backboard and vehicle seat using the same - Google Patents

Description

  The present invention relates to a seat backboard and a vehicle seat using the same.

  There is a demand for weight reduction of vehicle seats. Patent Document 1 listed below discloses that a spring that is stretched between a pair of left and right side frames provided on a seat back frame is made of resin from the viewpoint of reducing the weight of a vehicle seat.

JP 2004-138156 A

  Incidentally, some vehicle seats are provided with a flat backboard on the back side of the seat back. Since such a backboard is generally made of resin, it can be considered that the backboard is formed integrally or integrally with the resin spring as described above. That is, if a seat backboard having a backboard portion and a resin spring portion is formed and attached to the seatback frame, the number of parts and the number of assembling steps can be reduced.

  However, since a load from the occupant is input to the resin spring portion, if the stress concentrates on a part of the seat backboard due to the load, measures such as increasing the thickness of the part are necessary. This is against the request for weight reduction.

  In view of the above facts, an object of the present invention is to obtain a seat back board capable of suppressing stress concentration due to an input load to the resin spring portion and a vehicle seat using the seat back board.

The seat backboard according to the first aspect of the present invention is made of resin, a backboard portion disposed on the back side of the seatback frame, and a pair of left and right provided on the seatback frame, made of resin. Each side frame has a pair of left and right inner walls that are fixed to each of the side frames by a fixture and disposed on the inner side in the seat back width direction with respect to the pair of side frames. A pair of left and right connection fixing portions integrally or integrally connected to the portion, and made of resin, arranged along the seat back width direction between the pair of connection fixing portions, and at the center side in the seat back width direction The provided spring general part is arranged on the rear side of the seat back with respect to the fixture, and the seat back width direction outward from both ends of the spring general part in the seat back width direction And a pair of left and right front extending portions extending forward of the seat back are integrally or integrally connected to the pair of inner walls and inwardly in the seat back width direction of the fixture in the seat back width direction. Resin springs arranged side by side, and the side frame is provided with a side wall, a front wall, and a rear wall, and is formed in an open cross-sectional shape with an opening on the inner side in the seat back width direction, The connection fixing portion is disposed on the outer side in the seat back width direction of the side wall portion, and is fixed to the side wall portion by the fixing tool, and is disposed on the front surface side of the front wall portion, and the inner wall and the and it possesses a front wall which is connected to each front end of the outer wall, the.

  In the seat backboard according to claim 1, the pair of left and right connecting and fixing portions integrally or integrally connected to the backboard portion are connected to the left and right pair of the seat back frame by a fixture (bolts, nuts, clips, etc.). Fixed to the side frame. The pair of connecting and fixing portions has a pair of left and right inner walls disposed on the inner side in the seat back width direction with respect to the pair of side frames, and a resin spring portion is interposed between the pair of connecting and fixing portions. Are arranged along the seat back width direction. In the resin spring portion, the spring general portion provided on the center side in the seat back width direction is arranged on the rear side of the seat back relative to the fixing tool, which is a fixing position of the connecting and fixing portion to the side frame. In addition, the resin spring portion has a front extension portion extending from the both ends of the general spring portion in the seat back width direction to the seat back width direction outer side and the seat back front side, and is integrated with the inner walls of the pair of connection fixing portions. Or they are connected together. Thereby, compared with the case where the connection part of the resin spring part and the connection fixing part is arranged in the seat back width direction with respect to the spring general part, the distance from the connection part to the fixing position is shortened. Since it can set, it can suppress that stress concentrates on the said connection part periphery by the load from the passenger | crew input into the resin spring part.

Further, in the seat backboard this, connecting the fixed portion, an inner wall disposed in the seat back width direction inner side of the side wall portion of the side frame, the seat back width direction outer side end of the front extension portion of the resin spring portion An outer wall connected to the portion and disposed on the outer side of the side wall portion in the seat back width direction is fixed to the side wall portion by a fixture. Furthermore, the front wall which connected each front end of an inner wall and an outer wall is arrange | positioned at the front side of the front wall part of a side frame. Thereby, since the load from the passenger | crew loaded on a connection fixing | fixed part via a resin spring part can be received in the front surface of the front wall part of a side frame via the said front wall, the stress which arises in a connection fixing | fixed part can be received. Can be relaxed.

The seat back board according to claim 2 is the seat back board according to claim 1, wherein the connecting portion between the front extension portion and the connection fixing portion of the resin spring portion is from the seat back width direction. It is characterized by being arranged at a position overlapping the fixture as seen.

In the seat back board according to claim 2 , the connecting portion between the forward extension portion of the resin spring portion and the connecting and fixing portion overlaps with the fixing device when viewed from the seat back width direction, that is, between the fixing device and the occupant. Placed in. For this reason, when the occupant is inertially moved toward the fixture in the event of a side collision of the vehicle, the occupant can be efficiently protected by being interposed between the occupant and the fixture. .

A vehicle seat according to a third aspect of the present invention is the seat back frame, and the seat back board according to the first or second aspect , supported by the pair of left and right side frames in the seat back frame, A seat back pad disposed on the front side of the seat back board and a cover that covers the surface of the seat back pad are provided.

In the vehicle seat according to the third aspect , the seat back board supported by the pair of left and right side frames in the seat back frame supports the seat back pad covered with the cover from the rear surface side. Here, since this seat backboard is the one described in claim 1 or claim 2 , the above-mentioned effects can be obtained.

  As described above, in the seat backboard and the vehicle seat according to the present invention, stress concentration due to the input load to the resin spring portion can be suppressed.

It is a disassembled perspective view of the seat back of the vehicle seat which concerns on embodiment of this invention. It is a perspective view which shows the state by which the seat back board was assembled | attached to the seat back frame shown by FIG. FIG. 3 is an enlarged plan view showing an enlarged state of the seat back shown in FIG. 1 (an enlarged plan view showing a cut surface along line 3-3 in FIG. 2). FIG. 2 is an enlarged longitudinal sectional view showing an enlarged state of the seat back shown in FIG. 1. (A) is a model figure for demonstrating the bending moment which arises in the structure of a comparative example, (B) is a model figure for demonstrating the bending moment which arises in the structure of this embodiment.

  Hereinafter, an embodiment of a vehicle seat according to the present invention will be described with reference to FIGS. In addition, arrow FR shown suitably in each figure has shown the vehicle front direction, arrow UP has shown the vehicle up direction, and arrow W has shown the vehicle width direction. Moreover, the front-rear direction, the up-down direction, and the width direction (left-right direction) of the vehicle seat according to the present embodiment coincide with the front-rear direction, the up-down direction, and the width direction (left-right direction) of the vehicle.

<Overall configuration>
FIG. 1 is an exploded perspective view of a seat back that is a backrest of a vehicle seat according to the present embodiment. In FIG. 1, the angle at which each component is viewed is slightly changed. FIG. 4 shows a longitudinal sectional view of a vehicle seat provided with the seat back. As shown in these drawings, a vehicle seat 10 includes a seat cushion 11 (see FIG. 4) on which an occupant is seated, a seat back 12 that is tiltably supported at a rear end portion of the seat cushion 11, and a seat back. 12 and a headrest (not shown) supported by the upper end of 12 so as to be movable up and down. Note that an arrow A appropriately shown in each drawing indicates the front direction of the seat back 12, and an arrow B indicates the height direction of the seat back 12. Further, the width direction of the seat back 12 coincides with the vehicle width direction (seat width direction) W.

  As shown in FIG. 1, the seat back 12 includes a metal seat back frame 14 that constitutes a skeleton member of the seat back 12, and a resin spring integrated back board (hereinafter referred to as a front plate) mounted on the front side of the seat back frame 14. , Simply referred to as “seat back board”) 16, a seat back pad 18 that constitutes a cushion material of the seat back 12 and is attached from the front side of the seat back board 16 and supported by the seat back frame 14, A cover (skin) 20 that mainly covers the front surface of the back pad 18, and a vertical mounting member 22 and a horizontal mounting member 24 for mounting the cover 20 to the seat back board 16 are provided. Hereinafter, each component will be described in detail.

<Configuration of the seat back frame 14>
As shown in FIGS. 1 to 4, the seatback frame 14 is formed in a rectangular frame shape when viewed from the front (when viewed from the front of the vehicle). Specifically, a pair of left and right side frames 26 arranged to face each other in the seat back width direction, an inverted U-shaped upper frame 28 connecting the upper ends of the left and right side frames 26, and the left and right side frames 26. The lower frame 30 connecting the lower ends of the two in the seat back width direction. The seat back 12 includes all four members including the upper frame 28 by press molding, but other frame structures may be adopted. For example, only the upper frame may be formed of a pipe material bent in an inverted U shape, or the upper frame and a pair of left and right side frames may be configured of a single pipe material bent in an inverted U shape.

  Next, the sectional structure of the left and right side frames 26 will be described. As shown in FIGS. 2 and 3, the side frame 26 includes a side wall portion 26A, a front wall portion 26B, and a rear wall portion 26C, and an open cross section in which an inner side in the seat back width direction is opened. It is formed into a shape. The width of the side wall portion 26A becomes narrower from the lower end portion toward the upper end portion as a whole. A pair of upper and lower mounting holes 32 and 33 (see FIG. 1) are formed in the lower portion of the side wall portion 26A. The front wall portion 26B extends from the front end of the side wall portion 26A inwardly in the seatback width direction and slightly obliquely forward, and then extends inwardly in the seatback width direction and slightly obliquely rearward via an arc surface. Yes. The rear wall portion 26C extends inward from the rear end of the side wall portion 26A in the seat back width direction. A bulging portion that bulges in an arc shape toward the front side of the seat back is provided at the center portion of the rear wall portion 26 in the seat back width direction, and the front end portion of the rear wall portion 26 is bent obliquely toward the front side of the seat back. It has been. The width of the rear wall portion 26C is set sufficiently wider than the width of the front wall portion 26B. A mounting hole 34 (see FIG. 1) is also formed on the upper side of the rear wall portion 26C.

<Configuration of seat back board 16>
Next, the structure of the seat back board 16 which comprises the principal part of the vehicle seat 10 which concerns on this embodiment is demonstrated in detail. As shown in FIGS. 1 to 4 (particularly FIGS. 1 and 2), the seat back board 16 is formed of a resin plate material and is disposed on the back side of the seat back frame 14; It is made of resin and is provided integrally with the backboard portion 36, and is bridged so as to be supported by the pair of left and right side frames 26. Further, a load acting on the rear side of the seatback is applied, so that the load acting direction (seatback And a back spring portion 38 formed so as to be able to bend and deform toward the rear side.

  The backboard portion 36 includes a board body 40 that is formed slightly smaller than the seatback frame 14, and a U-groove locking portion 42 that is integrally formed on the outer periphery of the board body 40. . More specifically, the board body 40 is formed slightly smaller than the inner peripheral edge of the opening of the seat back frame 14 formed in a rectangular frame shape. In the assembled state to the seat back frame 14, the board body 40 is disposed slightly on the rear side of the seat back between the front end portions (inner end portions) of the rear wall portions 26 </ b> C in the left and right side frames 26. Therefore, the board body 40 can be assembled to the seat back frame 14 from the front side (see FIG. 3). The cross-sectional shape of the locking portion 42 is a U-shape with the seat back rear side open. The locking portion 42 is used to lock the outer peripheral portion of the cover 20 described later, and has a function of reinforcing the plate-like board body 40 and increasing the surface rigidity of the entire backboard portion 36. Yes.

  The back spring portion 38 includes a lower back spring portion 44 that is integrally formed on the lower side of the back board portion 36, and an upper back spring portion 46 that is integrally formed on the upper side of the back board portion 36. The upper back spring portion 46 is independently provided at a position separated from the lower back spring portion 44 by a predetermined distance in the seat back height direction.

  The lower back spring portion 44 includes three lower back spring main body portions 48, 49, 51 (resin spring portions) arranged in parallel in three upper and lower stages in the seat back height direction, and these three lower back spring main bodies. A pair of left and right lower board sides which are connected to the backboard portion 36 and fixed to the side frame 26 at both ends in the seatback width direction (longitudinal direction) of the portions 48, 49, 51 are connected to the seatback height direction. Part 50 (connection fixing part). It should be noted that the number of the lower back spring main body portions constituting the lower back spring portion 44 is arbitrary, and can be changed as appropriate in relation to the required cushion performance. Therefore, the upper and lower widths of the lower back spring main body portion may be widened to one, or conversely, two or four or more.

  As shown in FIG. 2, the lower back spring main body portions 48, 49, 51 have spring general portions 48 </ b> A, 49 </ b> A, 51 </ b> A provided on the center side in the seat back width direction formed in a wavy shape with a flat cross section. The springs general portions 48A, 49A, and 51A extend due to the load acting on the board portion 36 side (the seat back rear side). As a result, the lower back spring main body portions 48, 49, 51 are bent and deformed (elastically deformed) toward the backboard portion 36, which is the load acting direction. Further, the lower back spring main body portions 48, 49, 51 are linear in a plan view from both ends of the spring general portions 48A, 49A, 51A in the seat back width direction toward the outer side in the seat back width direction and toward the front side of the seat back. A pair of left and right front extending portions 48B, 49B, 51B (inclined portions). These forward extending portions 48 </ b> B, 49 </ b> B, 51 </ b> B are connected to the lower board side portion 50 at the end portions on the outer side in the seat back width direction. Note that a pair of left and right vertical openings 58 (long holes) are formed at both ends of the spring general portions 48A and 51A in the seat back width direction of the lower back spring main body portions 48 and 51 of the upper and lower stages. Between the vertical openings 58, a vertical locking portion 59 for locking the cover 20 is formed.

  As shown in FIG. 3, the above-described backboard portion 36 is disposed at a position spaced apart from the lower back spring portion 44 by a predetermined distance behind the seat back. That is, a predetermined gap 52 is formed between the lower back spring portion 44 and the back board portion 36. Within the gap 52, the lower back spring body 48, 49, 51 can be elastically deformed. That is, the backboard portion 36 also functions as a limiting member that limits the amount of bending of the lower back spring portion 44 to a predetermined amount or less.

  On the other hand, the lower board side portion 50 has an inner wall 50 </ b> A disposed on the inner side in the seat back width direction with respect to the side wall portion 26 </ b> A of the side frame 26. The inner wall 50A is provided with connecting portions 53, 55, 57 to which the outer end portions in the seat back width direction of the front extending portions 48B, 49B, 51B of the lower back spring main body portions 48, 49, 51 are connected. Yes. These connecting portions 53, 55, and 57 are disposed in the vicinity of the front wall portion 26 </ b> B of the side frame 26. Further, the lower board side portion 50 has an outer wall 50 </ b> B disposed on the outer side in the seat back width direction with respect to the side wall portion 26 </ b> A of the side frame 26. The outer wall 50B is disposed in parallel to the inner wall 50A and is in contact with the outer surface of the side wall portion 26A. Further, the lower board side portion 50 includes a front wall 50C in which the front end portions of the inner wall 50A and the outer wall 50B are connected to each other on the front side of the front wall portion 26B of the side frame 26, and a seat back width direction from the rear end portion of the inner wall 50A. And a rear side wall 50 </ b> D that extends inward and is connected to the backboard portion 36. The front wall 50C is linearly continuous with the front extending portions 48B, 49B, and 51B via the connecting portions 53, 55, and 57 on the inner side in the seat back width direction.

  The above-described three upper and lower lower back spring main body portions 48, 49, 51 have both ends in the seat back width direction (tip portions of the forward extending portions 48 B, 49 B, 51 B). It is connected. That is, the lower back spring main body portions 48, 49, 51 are provided in a plurality of stages in the seat back height direction, but both ends of the lower back spring main body portions 48, 49, 51 in the seat back width direction are the lower left and right pairs. By being connected by the side board side part 50, the lower back spring part 44 is integrated with the back board part 36. The longitudinal dimension of the lower board side part 50 is set so as to include a range from the upper edge of the upper lower back spring body part 48 to the lower edge of the lower lower back spring body part 51.

  As shown in FIG. 1, a pair of upper and lower through holes 61 and 63 are formed in the outer wall 50 </ b> B of the lower board side portion 50. The upper through hole 61 is arranged at the same height as the lower back spring body 48 of the upper stage, and the lower through hole 63 is arranged at the same height as the lower back spring body 51 of the lower stage. ing. The pair of upper and lower through holes 61 and 63 are formed at positions facing the pair of upper and lower mounting holes 32 and 33 formed in the side wall portion 26 </ b> A of the side frame 26. The lower board side portion 50 is provided with clips 65 and 67 (see FIGS. 2 and 3) that are fixing tools inserted into the through holes 61 and 63 from the outer side in the seat back width direction. Is fastened and fixed to the side frame 26 by being fitted and locked to the side frame 26. In addition, as a fixing means of the lower board side part 50, the structure which fastens to the side frame 26 with fasteners (fixtures), such as a rivet, a screw, a screw, or a bolt, and a weld nut, it is attached to the side frame 26 with a structural adhesive. Various aspects, such as a structure for bonding, can be applied.

  Here, in this embodiment, as shown in FIG. 3, the clip 65 disposed at the same height as the lower back spring body 48 of the upper stage is more than the spring general portion 48 </ b> A of the lower back spring body 48. It is arranged on the front side of the seat back. That is, the lower board side portion 50 is fastened and fixed to the side frame 26 on the front side of the seat back relative to the spring general portion 48A of the lower back spring main body portion 48. Further, in the present embodiment, the connecting portion 53 between the lower back spring main body portion 48 and the lower board side portion 50 in the upper stage is disposed on the front side of the seat back relative to the spring general portion 48A, and from the seat back width direction. It is arranged at a position overlapping the clip 65 when viewed. Further, in the present embodiment, the inner wall 50A of the lower board side portion 50 and the forward extension portion 48B of the lower back spring main body portion 48 are arranged in the seat width direction inside the clip 65 in the seat back width direction. Yes.

  In addition, although illustration by a closed cross section is abbreviate | omitted, the arrangement | positioning relationship of the connection part 57 and the clip 67 of the lower back spring main-body part 51 of a lower stage is also set similarly to the above. That is, as shown in FIG. 2, the clip 67 disposed at the same height as the lower back spring body 51 of the lower stage is disposed on the front side of the seat back relative to the spring general portion 51 </ b> A of the lower back spring body 51. The lower board side portion 50 is fastened and fixed to the side frame 26 on the front side of the seat back with respect to the spring general portion 51A. Further, the connecting portion 57 between the lower back spring main body portion 51 and the lower board side portion 50 in the lower stage is arranged on the front side of the seat back relative to the spring general portion 51A, and the clip 67 as viewed from the seat back width direction. It is arranged at the overlapping position. Further, the inner wall 50 </ b> A of the lower board side part 50 and the forward extension part 51 </ b> B of the lower back spring main body part 51 are arranged side by side in the seat width direction inside the clip 67 in the seat back width direction.

  Further, the lower back spring main body portion 49 in the middle stage is disposed so as to be shifted in the seat back height direction with respect to the clips 65 and 67, but the spring general portion 49A of the lower back spring main body portion 49 includes the clip 65, It is arranged behind the seat back from 67.

  On the other hand, the upper back spring portion 46 is basically configured in the same manner as the lower back spring portion 44, and includes an upper back spring main body portion 54 and an upper board side portion 56. The upper back spring main body 54 has a corrugated plane cross section so that it is stretched and deformed (elastically deformed) when a load is applied to the backboard 36 side (seat back rear side) on the center side in the seat back width direction. The formed spring general portion 54A is provided. Further, the vertical opening 58 and the vertical locking similar to the vertical opening 58 and the vertical locking portion 59 formed in the lower back springs 48 and 51 are provided at both ends of the general spring portion 54A in the seat back width direction. A portion 59 is formed. Further, a pair of upper and lower horizontal openings 69 are formed on both left and right sides of the middle part of the seat back width direction of the spring general portion 54A, and a lateral locking portion 71 is formed between the pair of horizontal openings 69. Yes.

  Further, the upper board side portion 56 has a shape protruding outward in the seat back width direction, and is set to have a longitudinal dimension that fits between the side wall portions 26A of the left and right side frames 26 described above. . Then, a clip 73 (see FIG. 2) inserted from the rear side of the seat back into the mounting hole 34 of the rear wall portion 26C is fitted and locked into a through hole 75 (see FIG. 1) formed in the upper board side portion 56. Thus, the upper board side portion 56 is fixed to the side frame 26. In addition, as a fixing means of the upper board side part 56, various aspects are applicable like the fixing means of the lower board side part 50 mentioned above.

<Configuration of the seat back pad 18>
As shown in FIG. 1, the seat back pad 18 is roughly composed of a pad center upper part 62, a pad center lower part 64, and a pair of left and right pad side parts 66. The seat back pad 18 is made of urethane foam or the like.

  As shown in FIG. 4, the vertical cross-sectional shape of the pad center upper portion 62 is formed in a substantially J shape that is upside down and left and right. The pad center upper part 62 is locked to the upper frame 28 of the seat back frame 14 from above the seat back. The vertical cross-sectional shape of the pad center lower portion 64 is formed in a substantially J shape that is opposite to the left and right. Moreover, the pad center lower part 64 has a shape in which the lower part swells in a convex curve shape from the upper part to the seat front side. The pad center lower portion 64 is locked from the lower side of the seat back to a connecting rod 68 that connects the lower ends of the side frames 26 in the seat width direction. The connecting rod 68 is disposed in parallel to the front side of the lower frame 30 of the seat back frame 14.

  Further, as shown in FIG. 3, the cross-sectional shape of the pad side portion 66 is formed in a substantially C shape. The pad side portion 66 is mounted so as to be wound around the side frame 26 in a state where the lower board side portion 50 is mounted. The pad side portion 66 has a shape in which the lower portion bulges in a convex curve shape from the upper portion to the front side of the seat back, and bulges to the front side of the seat back from the pad central upper portion 62 and the pad central lower portion 64. The side support for the occupant H is ensured.

  Returning to FIG. 4, the seat back board 16 described above is disposed from the back side lower end 62 </ b> A of the pad center upper part 62 to the back side upper end part 64 </ b> A of the pad center lower part 64 in the longitudinal sectional view. Precisely, the back side upper end portion 64A of the pad center lower portion 64 is formed thinner than the back side lower end portion 62A, and the lower end portion of the backboard portion 36 is disposed so as to overlap in the thinned portion. .

  Further, a lateral slit 70 as a through groove for hanging the cover is formed between the pad center upper part 62 and the pad center lower part 64 described above. Further, between the pad center upper part 62, the pad center lower part 64, and the pad side part 66, vertical slits 72 are formed as through grooves for hanging a pair of left and right covers. The slit width of the horizontal slit 70 and the vertical slit 72 is set to a length that allows the vertical mounting member 22 and the horizontal mounting member 24 to be described later to be inserted. Further, both the horizontal slit 70 and the vertical slit 72 are formed in a straight line, and penetrate the seat back pad 18 in the thickness direction (the seat back longitudinal direction).

<Configuration and mounting structure of cover 20>
As shown in FIG. 1, the cover 20 is formed in a size that can cover the seat back pad 18 from the front side. Further, the cover 20 includes a cover center upper portion 74, a cover center lower portion 76, and a pair of left and right cover side portions 78 in accordance with the divided configuration of the seat back pad 18. The cover 20 is attached to the seat back board 16 by a vertical mounting member 22, a horizontal mounting member 24, a vertical locking portion 59 and a horizontal locking portion 71 of the seat back board 16, and the like.

  As shown in FIG. 1, the longitudinal mounting member 22 includes a belt-shaped mounting member main body 22A, and a resin-made long clip mounting portion 22B provided on one side edge of the mounting member main body 22A. And a plurality of (here, three) long clips 22C attached to the clip attaching portion 22B. The other side edge of the attachment member main body 22A is attached in advance to the cover center upper portion 74, the cover center lower portion 76, and the cover side portion 78 by sewing. In FIG. 1, the vertical mounting member 22 (and the horizontal mounting member 24) is drawn separately from the cover 20, but the vertical mounting member 22 (and the horizontal mounting member 24) is attached to the cover 20 in advance. It has been. The plurality of clips 22 </ b> C are spaced apart from each other in the seat back height direction, and these clips 22 </ b> C are vertically locked portions 59 formed on the back spring main body portions 48, 51, 54 of the seat back board 16. The center portion of the cover 20 is attached to the seat back board 16 in the vertical direction by being elastically engaged with the seat back board 16.

  Similarly, the lateral mounting member 24 includes a belt-shaped mounting member main body 24A, a long resin clip mounting portion 24B provided on one side edge of the mounting member main body 24A, and the clip mounting portion 24B. And a plurality of (here, two) long clips 24C attached to the. The other side edge of the attachment member main body 24A is attached in advance to the cover center upper part 74 and the cover center lower part 76 by sewing. The plurality of clips 24 </ b> C are spaced apart from each other in the seat back height direction, and these clips 24 </ b> C are elastically applied to the pair of left and right laterally engaging portions 71 formed on the back spring main body portion 54 of the seat back board 16. Thus, the central portion of the cover 20 is attached to the seat back board 16 in the lateral direction.

  Further, an outer peripheral locking portion 80 having a hook shape is attached to an appropriate position of the outer peripheral portion of the cover 20 by sewing. The outer peripheral locking portion 80 is inserted and locked to the locking portion 42 of the backboard portion 36 from the vehicle rear side. As a result, the outer peripheral portion of the cover 20 is locked to the backboard portion 36.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  The vehicle seat 10 having the above configuration includes the seat back board 16 in which a resin back spring part 38 is integrally formed with a resin back board part 36. Then, the seat back board 16 is fitted to the metal seat back frame 14 from the front side of the vehicle. Specifically, the left and right board side portions 50 are fitted to the left and right side frames 26 from the front side of the vehicle, and are fixed to the side frames 26 from the outside in the seat width direction in this state. Thereafter, the seat back pad 18 is mounted on the seat back frame 14 from the front side of the vehicle, and the cover 20 is further put on the seat back pad 18. A vertical mounting member 22 and a horizontal mounting member 24 are fixed in advance to the cover 20 by sewing, and the clip 22C of the vertical mounting member 22 and the horizontal mounting member 24 are covered while the cover 20 is covered with the seat back pad 18. The clip 24 </ b> C is engaged with the corresponding vertical locking portion 59 and lateral locking portion 71. Further, the outer peripheral locking portion 80 of the cover 20 is locked to the locking portion 42 of the backboard portion 36.

  The seat back 12 assembled as described above is a vehicle seat 10 to which a seat cushion 11 and a headrest (not shown) are attached. When the occupant H sits on the vehicle seat 10, a load P (see FIG. 3) to the rear side of the seat back is input to the back spring portion 38 via the cover 20 and the seat back pad 18. For this reason, the lower back spring main body portions 48, 49, 51 and the upper back spring main body portion 54 are bent and deformed toward the seat back rear side which is the load acting direction. Further, since the load P at this time is transmitted from the left and right board side portions 50 to the left and right side frames 26, a reaction force from the left and right side frames 26 to the vehicle front side is generated.

  In this way, when the load P is input from the occupant H to the back spring portion 38, the load P itself is bent and deformed to contribute to securing the cushioning property of the seat back 12, and the load P itself is transmitted to the left and right side frames 26 and left and right. The side frame 26 is supported. As a result, the cushion performance of the seat back 12 is sufficiently ensured. Further, since the back spring portion 38 is made of resin and is provided integrally with the back board portion 36, the number of parts and the number of assembling steps are reduced as compared with the case where the back spring portion 38 is formed of a metal seat back spring. Is done. As a result, according to the present embodiment, the cushion performance of the seat back 12 can be sufficiently secured, and further weight reduction and cost reduction can be achieved.

  Here, in the present embodiment, the lower back spring main body portions 48, 49, 51 are arranged so that the spring general portions 48 A, 49 A, 51 A provided on the center side in the seat back width direction are the lower board side portions to the side frame 26. It is arranged on the rear side of the seat back with respect to the clips 65 and 67 which are 50 fastening and fixing positions. In addition, the lower back spring main body portions 48, 49, 51 have front extending portions 48B, 49B, 51B provided at both ends in the seat back width direction, which are connected to the front side of the seat back relative to the spring general portions 48A, 49A, 51A. The portions 53, 55, and 57 are integrally connected to the lower board side portion 50. Thereby, when the connection parts 53, 55, 57 are arranged side by side in the seat back width direction with respect to the spring general parts 48A, 49A, 50A, that is, the connection parts 53, 55, 57 are the spring general part 48A, Compared with the case where it extends from 49A, 50A outward in the seat back width direction, the distance from the connecting portions 53, 55, 57 to the clips 65, 67 is set shorter. As a result, it is possible to suppress the stress from being concentrated around the connecting portions 53, 55, 57 due to the load P from the occupant H input to the lower back spring main body portions 48, 49, 51.

That is, in the configuration of the comparative example shown in the model diagram of FIG. 5A, the point B that is the connecting portion between the lower back spring main body 48 and the lower board side portion 50 is the lower side to the side frame 26. It is far away from the point X, which is the fixed position of the board side portion 50, and there are two bent portions, point A and point B, between the point X and the lower back spring main body 48. Therefore, when the load P is inputted to the lower Bakkubane body part 48, together with the bending moment M _X is generated in the X point, the bending moment M _A is generated in the point A, the moment M _B bent further point B Occur. As a result, a large bend occurs, so that measures such as adding ribs and increasing the plate thickness may be required to reinforce the bending, which may lead to an increase in mass and cost. This also applies to the relationship between the lower back spring main body portions 49 and 51 and the lower board side portion 50.

On the other hand, in the configuration of the present embodiment shown in the model diagram in FIG. 5B, the point B in the comparative example is omitted, so that the bending moment MB around the point _B is eliminated and the load is reduced. To do. As a result, it is possible to reduce the plate thickness of the lower back spring main body 48 and the lower board side portion 50, so that weight reduction and cost reduction can be achieved.

  Further, in the present embodiment, the lower back spring main body portions 48, 49, 51 are directed from the both ends of the spring general portions 48A, 49A, 51A to the seat back width direction outward side and the seat back front side. The left and right lower board side portions 50 are connected to each other via a pair of left and right front extending portions 48B, 49B, 51B. These left and right front extending portions 48B, 49B, 51B are formed in a straight line in a plan view, and the direction along the load P from the occupant H to the rear side of the seat back that is input to the spring general portions 48A, 49A, 51A. Therefore, it can suppress that it is bent largely locally by the load P. Thereby, the stress concentration by bending can be suppressed.

  In addition, the left and right front extending portions 48B, 49B, 51B are set in the above-described extending directions from the spring general portions 48A, 49A, 51A that support the back of the occupant H on the center side in the seat back width direction. Therefore, the occupant H can be supported from the side by the left and right front extending portions 48B, 49B, 51B. Thereby, the hold | maintenance property (side support property) of the passenger | crew H by the seat back 12 can be improved.

  Further, in the present embodiment, as shown in FIG. 3, the inner wall 50 </ b> A of the lower board side portion 50 and the lower back spring main body 48 are located inward of the clip 65 in the seat back width direction (that is, in the direction of the occupant H). The forward extending portions 48B are arranged side by side in the sheet width direction. For this reason, when the occupant H is inertially moved toward the clip 65 at the time of a side collision of the vehicle, the two resin plates (the inner wall 50A and the forward extension 48B) are interposed between the clip 65 and the occupant H. Therefore, the occupant H can be efficiently protected as compared with the case where only one resin plate is interposed. Similarly, on the inner side in the seat back width direction of the clip 67 (that is, in the direction of the occupant H), the inner wall 50A of the lower board side portion 50 and the forward extension portion 51B of the lower back spring main body portion 51 are arranged in the seat width direction. Has been placed. For this reason, when the occupant H inertially moves toward the clip 67 at the time of a side collision of the vehicle, the two resin plates (the inner wall 50A and the forward extension 51B) are interposed between the clip 67 and the occupant H. Therefore, the occupant H can be efficiently protected as compared with the case where only one resin plate is interposed.

  Furthermore, in the present embodiment, the lower board side portion 50 has a front wall 50 </ b> C connecting the front ends of the inner wall 50 </ b> A and the outer wall 50 </ b> B disposed on the front side of the front wall portion 26 </ b> B of the side frame 26. As a result, the load P from the occupant H loaded on the lower board side portion 50 via the lower back spring main body portions 48, 49, 51 is transferred to the front surface of the front wall portion 26B of the side frame 26 via the front wall 50C. Therefore, the stress generated in the lower board side portion 50 can be relaxed.

  Furthermore, in the present embodiment, the connecting portion 53 between the lower back spring main body portion 48 and the lower board side portion 50 overlaps the clip 65 when viewed from the seat back width direction, that is, between the clip 65 and the occupant H. Arranged between. Similarly, the connecting portion 57 between the lower back spring main body portion 51 and the lower board side portion 50 is disposed at a position overlapping the clip 67 when viewed from the seat back width direction, that is, between the clip 67 and the occupant H. . For this reason, when the occupant H is inertially moved toward the clips 65 and 67 at the time of a side collision of the vehicle, the connecting portions 53 and 57 are interposed between the occupant H and the clips 65 and 67, so that the occupant H Can be protected efficiently.

  In addition, in the said embodiment, although it was set as the structure arrange | positioned in the position which the connection parts 53 and 57 overlap with the clips 65 and 67 (fixing tool) seeing from a seat back width direction, it is the invention which concerns on Claims 1-3. However, the present invention is not limited to this, and the positional relationship between the connecting portion and the fixture can be changed as appropriate.

  Further, in the above embodiment, the lower back spring main body portions 48, 49, 51 (resin spring portions) are located on the outer sides in the seat back width direction from the both ends of the spring general portions 48A, 49A, 51A in the seat back width direction. Although it was set as the structure provided with the left-right paired front extension part 48B extended linearly by planar view to the front side, and was connected with the right-and-left connection fixing | fixed part 50, the invention which concerns on Claim 1 is not restricted to this, The shape of the resin spring portion on both sides in the seat back width direction can be changed as appropriate. For example, instead of the front extension 48B, a configuration in which a curved portion that swells in a convex curved shape toward the rear side of the seatback in a plan view may be provided.

  Furthermore, in the said embodiment, although the lower back spring main-body part 48, 49, 51 (resin spring part) and the lower board side part 50 (connection fixing | fixed part) were connected integrally, Claim 1 This invention is not limited to this, and the resin spring part and the connecting and fixing part may be manufactured separately and then integrated by welding or the like. This also applies to the relationship between the backboard portion 36 and the lower board side portion 50.

  In the present embodiment, the back spring portion 38 is divided into the lower back spring portion 44 and the upper back spring portion 46 as described above. However, the present invention is not limited to this, and the two may be integrated. That is, a configuration may be adopted in which the lower board side portion 50 is extended to the upper side of the seat back and connected to both ends of the upper back spring main body portion 54 in the seat width direction.

  Further, in the present embodiment, the upper back spring portion 46 is configured in one step (one), but is not limited thereto, and may be configured in a plurality of steps (a plurality), and extends from the upper portion to the lower portion of the back board portion 36. Alternatively, a configuration in which a plurality of (a plurality of) back spring portions are provided at equal intervals may be employed.

  In addition, the present invention can be implemented with various modifications without departing from the scope of the invention. Needless to say, the scope of rights of the present invention is not limited to the above embodiment.

DESCRIPTION OF SYMBOLS 10 Vehicle seat 12 Seat back 14 Seat back frame 16 Seat back board 18 Seat back pad 20 Cover 26 Side frame 26A Side wall part 26B Front wall part 26C Rear wall part 36 Back board part 48, 49, 51 Lower back spring main body part ( Resin spring part)
48A, 49A, 51A Spring general part 48B, 49B, 51B Front extension part 50 Lower board side part (connection fixing part)
50A Inner wall 50B Outer wall 50C Front wall 53, 55, 57 Connecting part 65, 67 Clip (fixing tool)

Claims (3)

It is made of resin, and the backboard part arranged on the back side of the seat back frame,
A pair of left and right, made of resin, fixed to each of a pair of left and right side frames provided on the seat back frame by a fixture, and disposed on the inner side in the seat back width direction with respect to the pair of side frames A pair of left and right connecting and fixing portions integrally or integrally connected to both ends of the backboard portion in the seat back width direction,
It is made of resin and is arranged along the seat back width direction between the pair of connecting and fixing parts, and the spring general part provided on the center side in the seat back width direction is arranged on the rear side of the seat back than the fixing tool A pair of left and right front extending portions extending from the both ends of the general spring portion in the seat back width direction to the seat back width direction outer side and the seat back front side are integrally or integrally connected to the pair of inner walls. And a resin spring portion arranged side by side in the seat back width direction inside the seat back width direction of the fixture,
Equipped with a,
The side frame includes a side wall portion, a front wall portion, and a rear wall portion, and is formed in an open cross-sectional shape in which an inner side in the seat back width direction is opened
The connection fixing portion is disposed on the outer side in the seat back width direction of the side wall portion, and is fixed to the side wall portion by the fixing tool, and is disposed on the front side of the front wall portion, and the inner wall and And a front wall connecting the front ends of the outer wall .   2. The seat back according to claim 1, wherein a connecting portion between the front extending portion of the resin spring portion and the connecting and fixing portion is disposed at a position overlapping the fixing tool when viewed from the seat back width direction. board. The seat back frame;
The seat back board according to claim 1 or 2, supported by the pair of left and right side frames in the seat back frame,
A seat back pad disposed on the front side of the seat back board;
A cover covering the surface of the seat back pad;
Vehicle seat equipped with

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