JP6390288B2 - Seat back frame structure - Google Patents

Description

  The present invention relates to a seat back frame structure, and more particularly to a seat back frame structure of a vehicle seat.

  As a vehicle seat frame structure, there is a seat back frame structure that protects the occupant by effectively absorbing impact energy by moving or deforming the cross member spanned between the vertical frames rearward at the time of a rear collision. It is known (for example, see Patent Documents 1 to 3).

JP 2004-16708 A Japanese Patent Laid-Open No. 2001-239871 Japanese Patent Laid-Open No. 2001-71802

  The general seat back frame structure is constructed by spanning a cross member that supports the lumbar vertebrae of the passenger between a pair of left and right vertical frames, and firmly fixing the left and right ends of the cross member to the vertical frame with bolts and nuts. Increased rigidity. For this reason, there is a problem that the occupant's upper body is prevented from entering the seat back at the time of a rear collision, and the occupant is moved so as to float above the seat, so that the restraint performance of the headrest cannot be fully exhibited.

  In addition, the techniques described in Patent Documents 1 and 3 have a problem that the rigidity of the seat back structure is lowered because a part of the cross member is deformed at the time of a rear collision. Furthermore, in the technique described in Patent Document 2, when absorbing impact energy at the time of rear impact, a part of the vertical frame is broken and the cross member is slid and moved integrally with the stepped bolt. There is a problem that needs to be secured and causes an increase in cost.

  An object of the present invention is to provide a seat back frame structure capable of effectively absorbing an impact without hindering the entry of the occupant upper body into the seat back at the time of a rear collision.

  In order to achieve the above object, a seat back frame structure according to the present invention includes a pair of left and right vertical frames forming at least a part of a backrest portion of a vehicle seat, a frame main body portion extending in the left-right direction, and the frame main body portion. A horizontal frame including a pair of left and right assembly parts provided at both left and right ends, and a pair of left and right holding mechanisms that are assembled to the pair of left and right assembly parts and hold the horizontal frame with respect to the vertical frame, The portion is configured to restrict the vertical movement of the frame main body with respect to the vertical frame in a state where the holding mechanism is assembled, and to allow the frame main body to move backward with respect to the vertical frame. .

  Moreover, it is preferable that the said horizontal frame further includes the 1st flange part which makes the rear surface contact | abut to the front surface of the said vertical frame, and the intensity | strength of the said 1st flange part is set lower than the intensity | strength of the said frame main-body part. .

  Moreover, it is preferable to provide a notch part in the base part of the said 1st flange part.

  The horizontal frame has a pair of left and right second flange portions extending forward from left and right ends of the frame main body portion, the holding mechanism includes a bolt, and the assembly portion is provided on the second flange portion. The guide groove into which the bolt is inserted is formed, and the opening width in the vertical direction of the guide groove is set to a width that restricts the movement of the horizontal frame in the vertical direction with respect to the bolt. The opening width in the direction is preferably wider than the opening width in the vertical direction.

  According to the seat back frame structure of the present invention, it is possible to effectively absorb an impact without impeding the entry of the occupant upper body into the seat back at the time of a rear collision.

1 is a schematic perspective view showing a vehicle seat to which a seat back frame structure according to an embodiment of the present invention is applied. It is a typical perspective view which shows the principal part of the seat back frame structure of this embodiment. It is the sectional view on the AA line of FIG. It is a typical assembly exploded view explaining the assembly | attachment procedure to the vertical frame of the cross member of this embodiment. (A) is a typical side view showing the main part of the seat back frame structure of the present embodiment in a normal state, and (b) is a schematic side view showing the main part of the seat back frame structure of the present embodiment in a rear collision.

  Hereinafter, a seat back frame structure according to an embodiment of the present invention will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a perspective view showing a vehicle seat 1 to which a seat back frame structure 10 of the present embodiment is applied. The vehicle seat 1 includes a seat portion 2, a seat back 4 that can be tilted with respect to the seat portion 2 via a reclining device 3, and a headrest 5 that is assembled to the upper portion of the seat back 4. .

  The seat back frame structure 10 includes a pair of left and right vertical frames 11 extending in the vertical direction, an upper frame 12 extending in the horizontal direction between the upper ends of the vertical frames 11, and a cross member 20 extending in the horizontal direction. , A stepped bolt 32 and a nut member 33 are provided. The cross member 20 is an example of the horizontal frame of the present invention, and the stepped bolt 32 and the nut member 33 are preferable as an example of the holding mechanism of the present invention.

  The vertical frame 11 includes a lateral side surface, a front side surface extending inward in the left-right direction of the seat back 4 from the front end of the lateral side surface, and a rear side surface extending inward in the left-right direction of the seat back 4 from the rear end of the lateral side surface. For example, it is formed by bending a flat metal member or the like into a substantially U-shape. The lateral side surface of the vertical frame 11 is formed in a substantially triangular shape so as to become narrower from the lower end side toward the upper end side, and the lower end portion thereof is fixed to the reclining device 3. Further, a bolt insertion hole 11A (see FIG. 3) for inserting the stepped bolt 32 is provided on the lateral side surface of the vertical frame 11, and a nut member 33 is fixed to the inner side surface in the left-right direction by welding or the like. .

  More specifically, a stepped bolt 32 fitted with a bush 31 (shown in FIGS. 2 and 3) is screwed with a nut member 33, so that the assembly flange portion 22 of the cross member 20 described below can be slid. It is configured to hold (hold). In addition, it is preferable to set the height position which provides 11 A of bolt insertion holes to the height corresponding to the principal part of the passenger | crew who sat on the vehicle seat 1. FIG. Thereby, the cross member 20 can be functioned as lumbar support.

  The upper frame 12 is formed, for example, in a substantially U shape by bending the left and right ends of a pipe-shaped metal member downward, and the left and right lower ends thereof are fixed to the upper end of the vertical frame 11 by welding or the like. A pair of cylindrical brackets 12 a for assembling the headrest 5 are fixed to the left and right intermediate portions of the upper frame 12.

  The cross member 20 is a plate member made of, for example, a metal material. The cross member 20 has a frame main body 21 that extends in the left-right direction with its front side abutting against the rear side of the vertical frame 11, and left and right of the frame main body 21. A pair of left and right assembly flange portions (second flange portions) 22 that extend forward from both ends and have their lateral inner surfaces in contact with the lateral surfaces of the vertical frame 11, and from the front end of the assembly flange portion 22 to the inside And a pair of left and right positioning flange portions (first flange portions) 23 whose rear side surfaces are in contact with the front side surface of the vertical frame 11.

  More specifically, as shown in FIGS. 2 and 3, the assembly flange portion 22 is formed with a pair of guide grooves 30, which is an example of a receiving portion of the present invention. The guide groove 30 is set such that the opening width in the vertical direction is substantially the same as the outer diameter of the stepped bolt 32 and the opening width in the front-rear direction is longer than the outer diameter of the stepped bolt 32. That is, the stepped bolt 32 restricts the movement of the cross member 20 in the vertical direction, while allowing the movement in the front-rear direction.

  The positioning flange portion 23 determines the assembly position of the cross member 20 with respect to the vertical frame 11, and is extended from the front end portion of the assembly flange portion 22 at a substantially right angle. More specifically, as shown in FIG. 4, when the cross member 20 is assembled to the vertical frame 11, if the rear side surface of the positioning flange portion 23 is brought into contact with the front side surface of the vertical frame 11, The bolt insertion hole 11A is positioned on the end side (step S10). Then, the stepped bolt 32 into which the bush 31 is fitted is inserted into the guide groove 30 and the bolt insertion hole 11A and is screwed into the nut member 33 (shown only in FIGS. 1 and 3) (step S20). The member 20 can be easily positioned and assembled.

  Further, the positioning flange portion 23 of the present embodiment also has an impact absorbing function at the time of a rear collision of the vehicle. More specifically, as shown in FIG. 2, a pair of notches (notches) 23A is provided at the base of the positioning flange 23, and the strength of the notch 23A and the frame main body 21 are determined. Is set smaller than.

  That is, in the normal state, as shown in FIG. 5A, the positioning flange portion 23 prevents the cross member 20 from sliding backward, while in the rear-end collision of the vehicle, it is shown in FIG. 5B. As described above, the positioning flange portion 23 is buckled and deformed, and the cross member 20 is allowed to slide backward, so that the impact is effectively absorbed.

  Next, the effect by the seat back frame structure 10 of this embodiment is demonstrated.

  In the seat back frame structure 10 of the present embodiment, the positioning flange portion 23 is buckled and deformed at the time of rear collision of the vehicle, and the cross member 20 is supported rearward by the stepped bolt 32 in the guide groove 30. It is configured to slide. Therefore, according to the seat back frame structure 10 of the present embodiment, an impact can be effectively absorbed without impeding the entry of the occupant upper body into the seat back 4 at the time of a rear collision, and the occupant upper body. As a result, the restraint of the headrest 5 can be fully exhibited.

  Further, at the time of a rear collision, only the cross member 20 is slid rearward while the stepped bolt 32 is fixed to the vertical frame 11. Therefore, according to the seat back frame structure 10 of this embodiment, the smooth movement of the cross member 20 is ensured, and the impact at the time of a rear collision can be absorbed reliably.

  When the cross member 20 is assembled to the vertical frame 11, the bolt insertion hole 11 </ b> A is formed on the rear end side in the guide groove 30 only by bringing the rear side surface of the positioning flange portion 23 into contact with the front side surface of the vertical frame 11. Be positioned. Thereafter, the cross member 20 can be easily assembled only by inserting the stepped bolt 32 into the guide groove 30 and the bolt insertion hole 11A and screwing it with the nut member 33. Therefore, according to the seat back frame structure 10 of the present embodiment, the positioning and assembling workability of the cross member 20 can be effectively improved.

  In addition, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the meaning of this invention, it can change suitably and can implement.

  For example, the slide mechanism that holds the cross member 20 so as to be slidable is not limited to the stepped bolt 32, the nut member 33, and the guide groove 30, and may be configured by a guide rail or the like. In this case, the same effects as those of the above-described embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Vehicle seat 2 Seat part 3 Reclining device 4 Seat back 5 Headrest 10 Seat back frame structure 11 Vertical frame 12 Upper frame 20 Cross member (horizontal frame)
21 Frame body 22 Assembly flange (second flange)
23 Flange for positioning (first flange)
23A Notch 30 Notch 30 Guide groove 31 Bush 32 Stepped bolt (Holding mechanism)
33 Nut member (holding mechanism)

Claims (3)

A pair of left and right vertical frames forming at least part of the backrest of the vehicle seat;
A horizontal frame including a frame main body portion extending in the left-right direction and a pair of left and right assembly portions provided at both left and right ends of the frame main body portion;
A pair of left and right holding mechanisms that are assembled to the pair of left and right assembly parts and hold the horizontal frame with respect to the vertical frame,
The assembly part is configured to restrict the vertical movement of the frame body part relative to the vertical frame in a state where the holding mechanism is assembled, and to allow the frame body part to move backward relative to the vertical frame ,
The horizontal frame further includes a first flange portion whose rear surface abuts against the front surface of the vertical frame, and the strength of the first flange portion is set lower than the strength of the frame main body portion. Seat back frame structure. The seat back frame structure according to claim 1 , wherein a cutout portion is provided at a root portion of the first flange portion. The horizontal frame has a pair of left and right second flange portions extending forward from left and right ends of the frame main body, the holding mechanism includes a bolt, and the assembly portion is provided on the second flange portion. A guide groove for inserting a bolt is formed, and an opening width in the vertical direction of the guide groove is set to a width that restricts movement of the horizontal frame in the vertical direction with respect to the bolt. The seat back frame structure according to claim 1 or 2 , wherein the opening width is wider than the opening width in the vertical direction.

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