WO2018163539A1

WO2018163539A1 - Vehicle seat

Info

Publication number: WO2018163539A1
Application number: PCT/JP2017/043008
Authority: WO
Inventors: 洋平卜部; 郷詩藤田
Original assignee: テイ・エステック株式会社
Priority date: 2017-03-08
Filing date: 2017-11-30
Publication date: 2018-09-13

Abstract

[PROBLEM] To provide a vehicle seat capable of reducing a load applied to a cervical part of an occupant. [SOLUTION] According to the present invention, a vehicle seat (S) is provided with: a seat back frame (F3) that includes a pair of left- and right-side frames (1L, 1R) extending in the vertical direction, and an upper frame (3) connecting upper portions of the side frames (1L, 1R); and a headrest frame (7) that is coupled to the upper frame (3), wherein a fragile portion (4) having a rigidity lower than other portions of the upper frame (3) is provided on at least a portion of the upper frame (3).

Description

Vehicle seat

The present invention relates to a vehicle seat mounted on an automobile or the like, and more particularly to a vehicle seat provided with a mechanism for reducing a load applied to an occupant when an impact load is applied.

As a vehicle seat, there is a vehicle seat in which a weak portion is provided in a frame of a headrest that contacts the head in order to reduce a load applied to the head of the occupant at the time of a rear collision (for example, Patent Document 1). In the vehicle seat of Patent Document 1, the frame of the headrest is formed by a pipe, and includes a fragile portion that is deformed so as to have a flat cross section inside the headrest. At the time of a rear collision, the headrest supports the passenger's head from the rear side, and the fragile portion is plastically deformed, so that the load applied to the passenger's head is reduced.

Japanese Utility Model Application No. 5-12290

However, the vehicle seat of Patent Document 1 is deformed so that the frame of the headrest bends backward due to the load at the time of rear collision. Therefore, there is a possibility that the head moves backward with respect to the occupant's torso and a load is applied to the neck.

In view of the above background, an object of the present invention is to provide a vehicle seat that can reduce the load applied to the neck of an occupant.

In order to solve the above problems, a seat back frame (F3) including a pair of left and right side frames (1L, 1R) extending in the vertical direction and an upper frame (3) connecting the upper portions of both side frames; A headrest frame (7) coupled to the upper frame, and at least a portion of the upper frame is provided with a weakened portion (4, 100) having a lower rigidity than other portions of the upper frame. Good.

According to this configuration, the load applied to the occupant can be reduced when the fragile portion is deformed. Further, since the upper frame is coupled to the seat back frame, the load from the occupant is easily transmitted to the fragile portion.

In the above configuration, the headrest frame is connected to the upper frame between the left end portion (4L) located on the leftmost side and the right end portion (4R) located on the rightmost side of the weakened portion. It is good to be.

According to this configuration, when the headrest frame moves rearward due to the load applied to the upper body of the occupant, the fragile portion is deformed, so the load applied to the occupant's neck is reduced.

In the above configuration, the headrest frame is connected via at least two or more connecting portions provided in the upper frame, and the leftmost connecting portion (51L) located on the leftmost side of the connecting portions and the left end It is good that a part is connected by the said weak part, and the right side connection part (51R) located in the rightmost side among the said connection parts, and the said right end part are connected by the said weak part.

This configuration makes it easier for the headrest frame to move according to the load, so that the fragile portion is more easily deformed and the load applied to the occupant's neck is reduced.

Further, in the above configuration, the left connection portion and the right connection portion of the upper frame may be connected by the weak portion.

According to this configuration, the weakened portion located behind the occupant's neck is easily deformed, so that the load applied to the occupant's neck is further reduced.

In the above configuration, the headrest frame may be fixed to the upper frame.

According to this configuration, since the load applied to the occupant's head is easily transmitted to the upper frame, the load applied to the occupant's upper body is further reduced.

In the above configuration, the upper frame may be formed of a pipe-shaped member, and the weakened portion may be semicircular when viewed in cross section.

According to this configuration, the vulnerable part can be easily configured.

In the above configuration, the front wall of the fragile portion is formed in a semicircular arc shape in a cross-sectional view, the rear wall is formed in a plate shape in a cross-sectional view, and the headrest frame is coupled to the front surface of the fragile portion. Good.

According to this configuration, since the area of the portion where the headrest frame and the upper frame are coupled can be increased, the headrest frame and the upper frame can be easily coupled.

In the above configuration, the upper frame may be formed of a pipe-like member, and the weakened portion may be flattened in a sectional view.

According to this configuration, the fragile portion can be easily configured by deformation of the upper frame. Further, the rigidity of the upper frame between the coupling portions can be made lower than that of a semicircle.

In the above configuration, the upper frame may be formed of a pipe-like member, and an opening that penetrates toward the inside may be formed on a side surface of the fragile portion.

According to this configuration, the fragile portion for reducing the load applied to the occupant's neck can be easily configured by providing the opening in the upper frame.

Further, in the above configuration, it is preferable that the opening extends in the vertical direction at a substantially central position in the horizontal direction of the upper frame.

According to this configuration, when a load is applied to the occupant's neck, the load is applied to the occupant's neck by the deformation of the upper frame because the upper frame is bent rearward at a substantially central position in the left-right direction. The load applied to the cervix is reduced.

In the above configuration, the headrest frame may be coupled to the front surface of the upper frame.

This structure makes it difficult for the upper frame to come off the headrest frame when a load is applied to the vehicle seat from the front.

According to the above configuration, it is possible to provide a vehicle seat that can reduce the load applied to the neck of the occupant.

The perspective view of the vehicle seat which concerns on this invention 1 is an assembled perspective view of the vehicle seat of FIG. FIG. 2 is a front view of the seat back and a rear view of the vehicle seat when the back cover is removed. The perspective view when the back upper frame and headrest frame of the vehicle seat which concern on this invention are seen from diagonally forward The perspective view when the back upper frame and headrest frame of the vehicle seat which concern on this invention are seen from diagonally back VI-VI sectional view of FIG. VII-VII sectional view of FIG. Enlarged view of the connecting members on the left and right sides of FIG. Perspective view of connecting member XX sectional view of FIG. Explanatory drawing for demonstrating the load added between a back side frame and a back cover when a collision load is added The perspective view of the back upper frame and headrest frame of the vehicle seat which concern on another embodiment The perspective view of the back upper frame and headrest frame of the vehicle seat which concern on another embodiment A perspective view and a sectional view of another embodiment of a connecting member

Hereinafter, embodiments of a vehicle seat according to the present invention will be described with reference to FIGS. In the following description, the left and right sides and the inside and outside are determined based on the occupant seated on the vehicle seat. About the structure provided in right and left, a common number is attached | subjected, and when specifying left and right, the left or right character is attached | subjected to the name of a structure.

As shown in FIG. 1, the vehicle seat S is a so-called full bucket seat having a seat cushion S1 and a seat back S2 in which a backrest S3 and a headrest portion S4 are integrally formed. The seat cushion S1 includes a seat cushion frame, a pad and an outer skin that are placed on the upper side of the seat cushion frame, and supports the occupant's buttocks and thighs. The seat cushion frame is formed in a frame shape by a pair of left and right cushion side frames F2 extending in the front-rear direction and a plurality of frames that connect the side surfaces inside the cushion side frames F2. The seat back S2 is formed with a pair of left and right vents S5 penetrating back and forth at a position corresponding substantially to the shoulder of the occupant.

As shown in FIG. 2, the seat back S2 includes a seat back frame F3, a front cover C1 that covers the front side of the seat back frame F3, and a back cover C2 that is provided behind the seat back frame F3. . As shown in FIG. 2 and FIG. 3, the seat back frame F3 includes a pair of opposing left back side frame 1L and right back side frame 1R, and a back upper frame 3 connecting both the

back side frames

1L and 1R, and A back lower frame 5 and a headrest frame 7 coupled to the back upper frame 3 are provided.

Each

backside frame

1L, 1R is formed of a metal plate material in a U shape facing inward in a horizontal sectional view and extends substantially vertically. The

back side frames

1L and 1R are rotatably coupled to the rear end portions of the cushion side frames F2 via the reclining mechanism R at the lower end portions. The reclining mechanism R selectively holds the tilt angle of each of the

back side frames

1L, 1R with respect to the cushion side frame F2 at an arbitrary angle. The left back side frame 1L and the right back side frame 1R are spaced apart in the left-right direction and form the width of the seat back S2. A plate-like erection member 8 is provided between the left and

right backside frames

1L, 1R. The erection member 8 is supported by the left and right

back side frames

1L and 1R through a predetermined elastic member 9 so as to be displaceable back and forth, and supports the back of the occupant with elastic force. In this embodiment, the erection member 8 is formed using a plate-like member, but is not limited to the plate-like member, and is a known configuration formed by a configuration that provides a lumbar support function (for example, a spring). It's okay.

As shown in FIG. 3, a connecting member 10 that connects the

back side frames

1L, 1R and the back cover C2 is coupled to the rear walls of the lower end portions of the left and right

back side frames

1L, 1R.

As shown in FIG. 3, the back upper frame 3 is formed by one continuous pipe member bent in an inverted U shape facing downward when viewed from the back, and connects the upper ends of both the

back side frames

1L and 1R. ing. The back upper frame 3 has a shoulder portion 3A extending in the left-right direction and arm portions 3B extending downward from both ends of the shoulder portion, and inner surfaces of the corresponding back side frames 1L and 1R at the lower ends of the arm portions 3B. A part of the upper part overlaps and is joined by welding or the like. As shown in FIG. 6, the shoulder portion 3 </ b> A is provided with a fragile portion 4 that is deformed so as to form a semicircle having a wall surface facing rearward in a side view. The fragile portion 4 is formed over a predetermined range approximately at the center in the left-right direction of the shoulder portion 3A, as indicated by the oblique lines in FIG. In other words, the back upper frame 3 is deformed so as to have a semicircular arc-shaped wall surface facing forward and a planar wall surface facing rearward between the left end portion 4L and the right end portion 4R of the fragile portion 4. Yes. Further, sub-frames 6 are provided on the left and right ends of the upper portion of the back upper frame 3 to form portions that contact the shoulder of the occupant of the seat back S2.

Wire-like sub-side frames 30LU and 30RU for connecting the back upper frame 3 and the left and right back side frames 1L and 1R are provided inside the left and right back side frames 1L and 1R and outside the installation member 8 in the left and right direction. It has been. Frame-side locking portions 32 that are paired on the left and right are provided at predetermined positions of the sub-side frames 30LU and 30RU. In the present embodiment, the frame side locking portion 32 is formed as a wire extending in the vertical direction. Further, below the left and right sub-side frames 30LU and 30RU, there are provided sub-side frames 30LD and 30RD which are formed in the shape of a wire having an annular shape and whose both ends are coupled to the left back-

side frames

1L and 1R. Similarly, the frame side latching portions 32 are formed in the sub-side frames 30LD and 30RD. All the frame side locking portions 32 are arranged at a predetermined height above the connecting member 10.

As shown in FIGS. 4, 5, and 7, the headrest frame 7 includes a first headrest frame 50, a second headrest frame 52 and a third headrest frame 54 coupled to the upper front side of the first headrest frame 50. Have The first headrest frame 50 has a pair of left and right first

side frame portions

51L and 51R extending vertically and a first upper frame portion 51U connecting the upper ends of the first side frame portions and extending left and right. It is formed by a pipe member bent in a substantially inverted U shape facing downward when viewed from the front. The lower left ends and the lower right ends of the first

side frame portions

51L and 51R are both disposed between the left end portion 4L and the right end portion 4R, and are bent in a substantially arc shape along the front side wall surface of the back upper frame 3. The left and right first

side frame portions

51L and 51R are welded to the left connection portion 56L and the right connection portion 56R on the front surface of the back upper frame 3, respectively. At this time, the left connection portion 56L is disposed on the right side of the left end portion 4L, and the right connection portion 56R is disposed on the left side of the right end portion 4R. The first headrest frame 50 forms a part of the shape of the headrest portion S4 and also functions as a headrest pillar.

The second headrest frame 52 includes a pair of left and right second

side frame portions

53L and 53R coupled to the left and right first

side frame portions

51L and 51R at the rear ends, and front ends of the second

side frame portions

53L and 53R. A second front frame portion 53F that is connected and extends from side to side is provided. Due to the second

side frame portions

53L and 53R and the second front frame portion 53F, the second headrest frame 52 has a generally inverted U shape when viewed from the front. The second

side frame portions

53L and 53R are welded to the left and right inner surfaces of the first

side frame portions

51L and 51R at the rear ends, respectively, and extend upward along the first

side frame portions

51L and 51R. . Further, the second

side frame portions

53L and 53R are bent with respect to the first

side frame portions

51L and 51R, extend forward and leftward and rightward, then bend upward, and have a substantially L shape in a side view. There is no. The upper ends of the left and right second

side frame portions

53L and 53R are joined by a second front frame portion 53F extending in the left-right direction to form a surface 51S extending in the up-down and left-right directions. The surface 51S of the second headrest frame 52 forms the front surface of the headrest portion S4 with which the occupant's head abuts.

The third headrest frame 54 connects the left and right third

side frame portions

55L and 55R joined at the rear ends to the surfaces facing the left and right inner sides of the left and right first

side frame portions

51L and 51R, and the front ends thereof, A third front frame portion 55F extending left and right is provided. The third

side frame portions

55L and 55R are the front surfaces of the first

side frame portions

51L and 51R at the rear ends, respectively, and are connected to the first

side frame portions

51L and 51R and the second

side frame portions

53L and 53R. Is also welded to the upper side. The third

side frame portions

55L and 55R respectively extend upward from the welded portions and bend, and extend obliquely forward and upward with respect to the first

side frame portions

51L and 51R. The width in the left-right direction of the third front frame portion 55F is set to be wider than that of the second front frame portion 53F. The third front frame portion 55F abuts against the second front frame portion 53F from the rear, It is welded to the frame portion 53F. Due to the third

side frame portions

55L and 55R and the third front frame portion 55F, the third headrest frame 55 has a generally inverted U shape when viewed from the front. The first headrest frame 50, the second headrest frame 52, and the third headrest frame 54 form a skeleton of the headrest portion S4.

As shown in FIGS. 8, 9, and 10, the connecting member 10 is formed of a bent metal plate and is coupled to the left and right backside frames 1L, 1R. As shown in FIG. 4, the left and right connecting members 10 are formed so as to be symmetrical.

As shown in FIG. 9, the connecting members 10 are arranged vertically apart from each other, and each of the two frame coupling portions 12 coupled to the backside frame 1R and the cover coupling portion disposed between the two frame coupling portions. 14 and two leg pieces 16 for connecting the frame coupling portion 12 and the cover coupling portion 14 respectively. The upper frame coupling portion 12U is formed in a plate shape along the rear side surface of the rear wall of the backside frame 1R. In the present embodiment, in accordance with the shape of the backside frame 1R, the upper frame coupling portion 12U has a substantially triangular shape when viewed from the front. The lower frame coupling portion 12D is also formed in a plate shape along the rear side surface of the rear wall of the back side frame 1R, and has a substantially square shape when viewed from the front. The left and right widths of the upper and lower

frame coupling portions

12U and 12D are formed to be substantially equal. The cover coupling portion 14 is disposed between the upper and lower

frame coupling portions

12U and 12D in a front view and spaced rearward from the wall surface of the back wall of the back side frame 1R. It is formed in a parallel plate shape. The cover coupling portion 14 has a substantially square shape when viewed from the front, and the width in the left-right direction is substantially equal to the width in the left-right direction of the upper and lower

frame coupling portions

12U and 12D.

A screw hole 18 penetrating in the front-rear direction is formed at a substantially central position in the vertical and horizontal directions of the cover coupling portion 14. Furthermore, a notch 20 that is recessed outward is provided at the left and right inner edges of the cover coupling portion.

As shown in FIGS. 9 and 10, the upper leg piece portion 16U is formed in a plate shape extending substantially upward and rearward, and the base end is substantially the center in the left-right direction of the lower edge of the upper frame coupling portion 12U. The projecting end is coupled to the substantially central position in the left-right direction of the upper edge of the cover coupling portion 14. The lower leg piece portion 16D is formed in a plate shape extending substantially downward and rearward, the base end is coupled to the substantially central position in the left-right direction of the lower edge of the cover coupling portion 14, and the protruding end is coupled to the lower frame. The upper edge of the portion 12D is coupled to a substantially central position in the left-right direction. The widths of the upper and

lower leg pieces

16U, 16D in the left-right direction (the direction perpendicular to the extending direction of the leg pieces 16U) are both larger than the widths of the

frame connecting parts

12U, 12D and the cover connecting part 14 in the left-right direction. The

leg pieces

16U and 16D are set to have a width in the left-right direction so that the rigidity of the

leg pieces

16U and 16D is smaller than the rigidity of the back cover C2.

After the connecting member 10 is positioned with respect to the back side frame 1R using a positioning member that fits into the screw hole 18 and the cutout portion 20, the upper edge of the upper frame coupling portion 12U and the lower frame coupling portion 12D. The lower edge is welded to the back side frame 1R. In FIGS. 8A and 8B, the spot to be welded in the present embodiment is shown in gray.

As shown in FIG. 2, the front cover C1 includes a pad member 36 that is a cushioning material that joins the seat back frame F3 from the front, and a skin material 37 that covers the front side of the pad member 36. A through hole 39 penetrating back and forth is formed at a position corresponding to the vent S5 of the pad member 36. Similarly to the pad member 36, an opening is formed in the skin material 37 at a position corresponding to the vent S5. A resin garnish 40 extending substantially in the rear is fitted in the opening of the skin material and the through hole 39 of the pad member 36. A plurality of locking claws (not shown) projecting in the inner circumferential direction are formed on the outer periphery of the rear end of the garnish 40.

The back cover C2 is a resin plate member disposed along the back surface of the seat back S2, and is formed symmetrically. The back cover C <b> 2 includes a base portion 60 having a substantially square shape, and a head portion 61 that extends upward from the upper edge portion of the base portion 60 continuously to the base portion 60. The back cover C2 is coupled to the back surface of the seat back S2 so that the base 60 covers the backrest portion of the vehicle seat S and the head 61 covers the headrest portion S4 of the vehicle seat S. A pair of left and right through-holes 62 are formed in the upper portion of the base 60 at a position corresponding to the vent S5, and a cylindrical cover connecting portion 63 extends forward from the edge. A plurality of engagement holes, which are through-holes arranged so as to be aligned along the front end edge, are formed at the front end of the cover connecting portion 63. The engagement hole is disposed at a position where it engages with the locking claw of the garnish 40. A cover side locking portion 68 that is paired on the left and right sides of the back cover C2 is provided at the upper portion of the back cover C2 and at the substantially central portion in the vertical direction.

A through hole 72 penetrating the back cover C2 back and forth is provided at a position below the base 60 of the back cover C2 and below the cover side locking portion 68 and corresponding to the screw hole 18 of the connecting member 10. ing. In the present embodiment, in order to improve the design, a countersink process for sinking the screw head is applied to the rear opening edge of the through hole 72.

Next, a method for assembling the seat back S2 of the vehicle seat S will be described. As shown in FIG. 2, the back cover C <b> 2 is coupled to the seat back frame F <b> 3 by engaging the cover side locking portion 68 and the frame side locking portion 32. Further, the locking claw of the garnish 40 is fitted into the engagement hole of the back cover C2, and the front cover C1 and the back cover C2 are fixed to the seat back frame F3. Further, the lower part of the back cover C2 is fixed to the seat back frame F3 by passing a screw through the through hole 62 of the back cover C2 and coupling it to the screw hole 18 provided in the connecting member 10. As a result, the front cover C1 and the back cover C2 are joined to the seat back frame F3, and the seat back S2 is completed.

Next, the effect of the vehicle seat S will be described. When an impact from the rear is applied to the vehicle body, an inertial force toward the rear is applied to the occupant. Due to the inertial force applied to the occupant, the occupant's neck moves backward, and a rearward load is applied to the upper portion of the seat back S2.

As described above, the fragile portion 4 of the back upper frame 3 is formed in a semicircular shape in cross-sectional view, and the other part of the back upper frame 3 is formed in a circular shape in cross-sectional view. The fragile portion 4 is less rigid than the other portions. Therefore, the back upper frame 3 is bent backward at the fragile portion 4 and plastically deformed due to the backward load. Since the load is absorbed by the deformation of the fragile portion 4, the load applied to the occupant's neck is reduced.

The left connection portion 56L and the right connection portion 56R are both provided between the left end portion 4L and the right end portion 4R, and the left connection portion 56L and the left end portion 4L, and the right connection portion 56R and the right end portion 4R are both fragile portions 4. Connected by. Therefore, the weak part 4 is deformed by the load applied to the upper body of the occupant, and the headrest frame 7 can be moved rearward. Since the load is absorbed by the deformation of the fragile portion 4, the load applied to the occupant's neck is reduced.

In addition, since the left connecting portion 56L and the right connecting portion 56R are also connected by the fragile portion 4, when a rearward load is applied to the occupant's neck, the space between the left connecting portion 56L and the right connecting portion 56R. The fragile part 4 is also deformed. Therefore, the load applied to the occupant's neck is further reduced.

Further, since the headrest frame 7 is fixed to the back upper frame 3, when the collision load is applied, the headrest frame 7 moves with respect to the backrest S3, and the possibility of applying an impact to the occupant is reduced. Furthermore, since the headrest frame 7 is fixed to the back upper frame 3, the load applied to the occupant's head is easily transmitted to the back upper frame 3, and the load applied to the upper body of the occupant is further reduced.

Further, the fragile portion 4 is formed by deforming a pipe-like member constituting the back upper frame 3 so as to form a semicircular shape in a sectional view. Therefore, a weak part can be provided easily. Further, since the front wall of the fragile portion 4 is formed in a semicircular arc shape in a sectional view and the headrest frame 7 is coupled to the front wall, the area of the portion where the headrest frame 7 and the back upper frame 3 are coupled is large. It becomes easy to bond more firmly.

Further, since the headrest frame 7 is coupled to the front surface of the back upper frame 3, the back upper frame 3 is unlikely to come off the headrest frame 7 when a load is applied to the vehicle seat S from the front.

Since both the second headrest frame 52 and the third headrest frame 54 are coupled to the first headrest frame 50 at different locations, the load applied to the headrest portion S4 is applied to different locations of the first headrest frame 50. Is distributed. Therefore, the load is not concentrated and the first headrest frame 50 is not easily deformed.

The second headrest frame 52 is joined at the rear end so as to extend forward with respect to the first headrest frame 50 to form a surface 51S. Therefore, the 2nd headrest frame 52 can support the load to the back added to a crew member's head. Since the third front frame portion 55F is welded to the rear side of the second front frame portion 53F, the load applied to the second headrest frame 52 is also transmitted to the third headrest frame 54 and is applied to the first headrest frame 50. Does not concentrate.

The head of an occupant sitting on the rear seat may collide with the upper part of the headrest portion S4 during a rear collision. As shown in FIG. 7, since the third headrest frame 54 is provided so as to extend forward and upward, the third headrest frame 54 can support a load from the upper portion of the headrest portion S4. Further, the second front frame portion 53F is welded to the front side of the third front frame portion 55F, and the upper surface of the second front frame portion 53F and the upper surface of the third front frame portion 55F are formed to be aligned. Therefore, the load applied to the upper portion of the headrest portion S4 is also applied to the second headrest frame 52, and the load applied to the first headrest frame 50 is not concentrated.

When a collision load is applied to the vehicle seat, a load in a direction that causes a relative displacement between the back cover and the seat back frame is applied to a joint portion between the back cover and the seat back frame, which causes a problem that the back cover is deformed. There is. Therefore, it is desirable to provide a vehicle seat in which the back cover is not easily deformed.

More specifically, the upper portion of the seat back S2 moves rearward due to the rearward load. Therefore, the vehicle seat S may be bent so as to warp forward (for example, FIG. 11). Due to this bending, as indicated by the black arrows in FIG. 11, a load directed rearward and upward is applied to the backside frames 1L and 1R, and a load directed forward and downward is applied to the back cover C2. With these loads, a shear load is applied to the connecting member 10 that joins the back side frames 1L, 1R and the back cover C2.

As shown in FIGS. 8A and 8B, the

leg pieces

16U and 16D have a smaller width in the left-right direction compared to the cover coupling portion 14 and the

frame coupling portions

12U and 12D, and the cover coupling portion 14 and the frame coupling. Rigidity is low compared to the

portions

12U and 12D. Therefore, the

leg pieces

16U and 16D are more easily deformed than the cover coupling portion 14 with respect to the load generated at the coupling portion between the back cover C2 and the back side frames 1L and 1R. The load generated in the coupling portion is easily absorbed by the

leg pieces

16U and 16D, and the portion where the back cover C2 and the cover coupling portion 14 are coupled is not easily deformed, so that the back cover C2 is protected. Furthermore, the width of the

leg pieces

16U, 16D in the left-right direction is such that the rigidity of the

leg pieces

16U, 16D is smaller than that of the back cover C2, and the rigidity of the cover coupling portion 14 and the

frame coupling portions

12U, 12D is greater than that of the back cover C2. It is set to be large. Therefore, when a shear load is applied, the connecting member 10 is deformed and the load is absorbed, so that the back cover C2 is difficult to deform.

Further, when the upper portion of the seat back S2 moves rearward, as shown by the white arrow in FIG. 11, a load that pushes the lower end of the back cover C2 forward may be applied. The cover coupling portion 14 is pushed forward by the load toward the front. Since the end portions of the

leg piece portions

16U and 16D on the cover joint portion side are located behind the end portions on the frame

joint portions

12U and 12D side, there is a gap between the seat back frame F3 and the back cover C2. Is formed.
Therefore, when the load which pushes the cover coupling | bond part 14 ahead is added, the

leg piece parts

16U and 16D can deform | transform. Thus, since the gap is formed between the seat back frame F3 and the back cover C2, a space in which the

leg pieces

16U and 16D can be deformed is secured. Due to the deformation of the

leg pieces

16U and 16D, the load applied to the back cover C2 is reduced, and the back cover C2 becomes difficult to deform. Further, since a gap is formed between the seat back frame F3 and the back cover C2, the screw can be turned until it protrudes into the gap. Therefore, it is not necessary to strictly determine the length of the screw, and the back cover C2 can be easily coupled to the seat back frame F3.

The back cover C2 is provided with a cover side locking portion 68, and the back cover C2 is coupled to the frame side locking portion 32 at one end side (upper side) in the vertical direction. The connecting member 10 is provided at the other end (lower end) in the vertical direction of the back cover C2, and the back cover C2 is coupled to the frame side locking portion 32 at the lower end. Since the frame side locking portion 32 and the back cover C2 are arranged at different heights, the back cover C2 having a shape extending in the vertical direction can be reliably coupled to the seat back frame F3. Further, since the connecting member 10 is provided at the lower end of the back cover C2, the cover-side locking portion 68 can be locked to the frame-side locking portion 32 and then screwed, and the seat back frame F3 can be secured. And the back cover C2 can be easily assembled.

The seat back frame F3 and the back cover C2 can be easily coupled by the connecting member 10. Since the connecting member 10 and the seat back frame F3 are connected via the two

frame coupling portions

12U and 12D, the coupling between the seat back frame F3 and the back cover C2 is strengthened.

This is the end of the description of the specific embodiment, but the present invention is not limited to the above-described embodiment, and can be widely modified. As shown in FIG. 12, the fragile portion 104 may be formed as a portion in which the back upper frame 3 is deformed flat. Also in this case, the fragile portion 104 bends backward due to a backward load, so that the load applied to the occupant's neck is reduced. Moreover, since the rigidity can be lowered by the deformation of the back upper frame 3 as in the above embodiment, it is easy to provide the fragile portion 104.

As shown in FIG. 12, when the fragile portion 104 is formed as a flatly deformed portion, as compared with the case where the fragile portion 4 is formed in a semicircular shape in a sectional view as shown in FIG. The rigidity of the fragile portion 104 is reduced. Therefore, when the fragile portion 104 is formed as a flatly deformed portion, the back upper frame 3 can be bent with a lower load, and the load applied to the occupant's neck can be reduced even with a lower load. it can. Thus, the threshold value of the load that causes deformation can be adjusted by the shape of the back upper frame 3.

As shown in FIG. 13, the weakened portion 204 may be formed by forming an opening portion 200 of a predetermined size penetrating inside the back upper frame 3. By forming the opening 200, the rigidity between the locations where the first

side frame parts

51L and 51R are welded becomes smaller than the rigidity of the other parts of the back upper frame 3. Therefore, also in the back upper frame 3 shown in FIG. 13, when a backward load is applied, the back upper frame 3 bends backward, so that the load applied to the occupant's neck is reduced. In addition, since the rigidity can be reduced by forming the opening 200, it is easy to provide the fragile portion 204.

Further, as shown in FIG. 13, the opening 200 may be formed to extend in the vertical direction at a substantially central position in the left-right direction of the back upper frame 3. According to this configuration, when a load is applied to the occupant's neck, the back upper frame 3 bends backward at a substantially central position in the left-right direction. Therefore, the load applied to the occupant's neck is effectively absorbed by the deformation of the back upper frame 3, and the load applied to the occupant's neck is easily reduced.

In order to make the leg piece 16 a fragile part that is easily deformed when a load is applied, the width in the left-right direction of the leg piece 16 is set to be smaller than the frame coupling part 12 and the cover coupling part 14. However, any configuration may be used as long as the rigidity of the leg piece portion 16 is lower than that of the back cover C2. For example, the leg piece 16 may have a lower rigidity than the back cover C2 by reducing the width (thickness) of the leg piece 16 in the front-rear direction. Only a part of the leg piece 16 may be provided with a portion having a small width in the left-right direction to reduce the rigidity of the leg piece 16.

For example, as shown in FIG. 14A, only the width in the left-right direction of the upper leg piece 16U is configured to be smaller than the width of the cover coupling portion 14 and the width of the

frame coupling portions

12U and 12D. May be. Also with this configuration, the connecting member 10 functions as a fragile portion that deforms when the above-described load is applied, and the back cover C2 is less likely to be deformed. Further, the frame coupling portion 12 may be arranged on the top and bottom and the left (or right) with respect to the cover coupling portion 14, and each frame coupling portion 12 may be coupled to the cover coupling portion 14 via the leg piece portion 16. . At this time, the width in the left-right direction of the leg piece portion 16 extending in the vertical direction is set to be smaller than the width of the frame coupling portion 12 and the cover coupling portion 14, and the vertical direction of the leg piece portion 16 extending in the left-right direction. Is preferably set to be smaller than the width of the frame coupling portion 12 and the cover coupling portion 14.

As shown in FIG. 14B, the connecting member 10 shown in FIG. 8 is rotated by 90 degrees, and the cover coupling portion 14 and the frame coupling portion 12 are arranged so as to be aligned in the left-right direction. It may be attached to 1R. At this time, the leg piece 16 connects the right edge of the left frame coupling portion 12 and the left edge of the cover coupling portion 14 to the left edge of the right frame coupling portion 12 and the right edge of the cover coupling portion 14. Yes. The vertical width of the leg piece 16 may be set smaller than the width of the frame coupling part 12 and the cover coupling part 14. Even in this case, when a load toward the front is applied to the cover coupling portion 14, the leg piece portion 16 is deformed and the load applied to the back cover C2 is reduced, so that the back cover C2 is hardly deformed.

Further, similarly to the above embodiment, since the cover coupling portion 14 is located behind the frame coupling portion 12, a gap between the seat back frame F3 and the back cover C2 can be reliably provided, and the connecting member 10 Space required for deformation is secured. Moreover, since the connection member 10 and the seat back frame F3 are connected at two places as in the above-described embodiment, the coupling between the seat back frame F3 and the back cover C2 becomes strong.

As shown in FIG. 14C, a connecting structure 110 that connects the back cover C2 and the back side frames 1L, 1R is provided by providing through holes 108 that pass through the back side frames 1L, 1R in the front-rear direction. It may be configured. The connection structure 110 shown in FIG. 14 (C) has a pair of through-holes 108 that are symmetrically formed on the rear walls of the back side frames 1L and 1R and that are substantially U-shaped and face each other. A pair of cover coupling portions 112 having a substantially square shape defined by the through-holes 108, and upper and lower ends of the cover coupling portion 112 and a frame main body 114 serving as a main body of the back side frames 1L and 1R, respectively. Leg piece 116. A screw hole 118 penetrating in the front-rear direction is provided at a substantially central position in the left-right and vertical directions of the cover coupling portion 112. The back cover C2 is screwed to the cover coupling portion 112 through a through-hole 62 provided in the lower portion, and is fixed to the back side frames 1L and 1R.

In the connection structure 110 shown in FIG. 14C, the cover coupling portion 112 is surrounded by a pair of through-holes 108, and the back side frames 1L and 1R are framed via leg pieces 116 provided on the upper and lower sides, respectively. It is connected to the main body 114. Therefore, when a forward load is applied to the cover coupling portion 112, the leg piece portion 116 is deformed, and the load applied to the back cover C2 is reduced, so that the effect that the back cover C2 becomes difficult to deform is obtained. Further, the connection structure 110 has an advantage that the leg piece portion 116 that can reduce the load applied to the back cover can be provided without providing the connection member 10 separately.

S2: Seat back S4:

Headrest portion

1L, 1R: Back side frame 3: Back upper frame (upper frame)
4: weak part 4L: left end part 4R: right end part 7: headrest frame 56L: left side connection part 56R: right side connection part 104: weak part 204: weak part

Claims

A pair of left and right side frames extending in the vertical direction, and a seat back frame including an upper frame connecting the upper portions of both side frames;
A headrest frame coupled to the upper frame;
The vehicle seat according to claim 1, wherein at least a part of the upper frame is provided with a weak part having a lower rigidity than the other part of the upper frame.
2. The vehicle according to claim 1, wherein the headrest frame is connected to the upper frame between a left end portion located on a leftmost side and a right end portion located on a rightmost side among the weakened portions. Sheet.
The headrest frame is connected at at least two or more connecting portions provided on the upper frame,
The left side connection part located on the leftmost side of the connection part and the left end part are connected by the fragile part,
The vehicle seat according to claim 2, wherein the right-side connection portion located on the rightmost side of the connection portion and the right end portion are connected by the fragile portion.
The vehicle seat according to claim 3, wherein the left connecting portion and the right connecting portion of the upper frame are connected by the fragile portion.
The vehicle seat according to claim 4, wherein the headrest frame is fixed to the upper frame.
The vehicle seat according to any one of claims 2 to 5, wherein the upper frame is formed by a pipe-shaped member, and the cross-section of the fragile portion has a semicircular shape.
The front wall of the fragile portion is formed in a semicircular arc shape in a cross-sectional view, the rear wall is formed in a plate shape in a cross-sectional view, and the headrest frame is coupled to the front surface of the fragile portion. 6. The vehicle seat according to 6.
The vehicle seat according to any one of claims 2 to 5, wherein the upper frame is formed of a pipe-like member, and a cross section of the fragile portion is flattened.
The upper frame is formed by a pipe-shaped member, and an opening that penetrates toward the inside is formed on a side surface of the fragile portion. The vehicle seat described.
The vehicle seat according to claim 9, wherein the opening extends in a vertical direction at a substantially central position in a horizontal direction of the upper frame.
The vehicle seat according to any one of claims 1 to 10, wherein the headrest frame is fixed to a front surface of the upper frame.