JP4463758B2 - Shock absorbing structure for vehicle seat - Google Patents

Description

  The present invention relates to an impact absorbing structure for a vehicle seat that reduces an impact acting on an occupant when an impact is input from the rear of the vehicle.

  It is known that when an impact load is input from the rear part of the vehicle, the upper body of the occupant seated by restraint by the seat belt is strongly pushed back to the seat back or the headrest.

As a vehicle seat that can relieve the impact of the occupant under such circumstances, the seat cushion can be tilted so that the front side of the seat is lifted with the movement of the center of gravity of the occupant when the impact is input from the rear of the vehicle body. The thing provided with the resistance generation | occurrence | production means which generate | occur | produces damping resistance according to tilting of a cushion is devised (for example, refer patent document 1).
In this vehicle seat, the rear end portion of the seat cushion is pivotally supported on the movable rail piece of the seat rail by a pivot, and resistance generating means is provided between the front end portion of the seat cushion and the movable rail piece. Yes. The resistance generating means includes a tongue piece protruding from the upper surface of the movable rail piece and having a slit extending in the vertical direction, and a resistance shaft protruding from the seat cushion and fitted into the slit of the tongue piece. When the seat cushion is tilted so that the front side is lifted when an impact load is input, the resistance shaft slides in the slit, and the impact acting on the occupant is absorbed by the frictional resistance at this time.
JP 2003-260968 A

  However, in the case of the conventional shock absorbing structure for a vehicle seat, a tongue piece is projected on the movable rail piece, and the resistance shaft on the seat cushion side is inserted into the slit of the tongue piece. If it is intended to sufficiently secure the impact damping stroke of the generating means, the protruding height of the tongue piece with respect to the movable rail piece inevitably increases, and it becomes difficult to reduce the height of the seat cushion.

  Accordingly, the present invention is intended to provide an impact absorbing structure for a vehicle seat capable of ensuring a sufficient impact attenuation stroke of the resistance generating means without causing an increase in the height of the seat cushion.

As a means for solving the above-mentioned problems, the invention according to claim 1 is directed to a seat cushion (for example, a seat cushion 2 in an embodiment described later) seated by an occupant as a seat rail (for example, a seat in an embodiment described later). Between the movable rail piece of the seat rail (for example, the upper rail 11 in the embodiment described later) and the seat cushion, when the impact is input from the rear of the vehicle body, the front portion of the seat cushion is installed on the vehicle body via the rail 5). Resistance generating means (for example, a damper 16 in an embodiment to be described later) that allows the upper displacement of the seat cushion and a stopper member (for example, to be described later) that restricts the downward displacement of the front portion of the seat cushion with respect to the movable rail piece. the vehicle seat and the stopper member 17) in the embodiment is provided (e.g., the embodiments described below In the shock absorber for a definitive vehicle seat 1), a flat mounting base that is coupled to the upper surface of said movable rail member (e.g., mounting base 14a in the embodiment to be described later), the inner side of the seat rail from the mounting base And a lower bracket (for example, a lower bracket 14 in an embodiment to be described later) formed with a channel portion (for example, a channel portion 14b in an embodiment to be described later) having an opening facing upward. ) And the lower ends of the stopper member and the resistance generating means are arranged in the channel portion of the lower bracket.
As a result, when the center of gravity of the occupant moves so that the upper body of the occupant seated on the seat falls backward due to an impact input from the rear of the vehicle body, the front side of the seat cushion is lifted, and at this time, the resistance generating means generates a damping resistance. To absorb the impact acting on the passenger. The resistance generation means generates a damping resistance below the seat cushion with its lower end positioned lower than the upper surface of the movable rail piece.
Further, during normal use without an impact input, the weight of the seat and the occupant is transmitted to the movable rail piece via the stopper member, and an unnecessary load is not applied to the damping force generating portion of the resistance generating means.

  According to the first aspect of the present invention, since the lower end portion of the resistance generating means is attached to the movable rail piece at a position lower than the upper surface of the movable rail piece of the seat rail, the resistance is maintained while suppressing the height of the seat cushion. A sufficient shock attenuation stroke of the generating means can be ensured.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the vehicle seat 1 in this embodiment is a separate seat on the front seat side provided with a front and rear slide mechanism.

  As shown in FIG. 1, the vehicle seat 1 includes a seat cushion 2 that supports the occupant's buttocks, a seat back 3 that supports the waist and back of the occupant, and a headrest 4 that supports the head of the occupant. The cushion 2 is attached to the vehicle body via a pair of left and right seat rails 5 along the vehicle body longitudinal direction. The seat back 3 has a lower end connected to the rear end of the seat cushion 2 so as to be tiltable, and the headrest 4 is attached to the upper end of the seat back 3 so as to be adjustable up and down.

  In the seat cushion 2, side brackets 7 are attached to both sides in the vehicle width direction of a seat frame 6 that supports a spring material and a cushion material (not shown), and the side bracket 7 portions are connected to corresponding seat rails 5 on the left and right. .

  As shown in FIGS. 1 and 2, the left and right seat rails 5 are connected to a lower rail 10 as a fixed rail piece attached to the floor 8 of the vehicle body via bases 9a and 9b and corresponding left and right side brackets 7, respectively. On the other hand, the lower rail 10 is provided with an upper rail 11 as a movable rail piece held so as to be slidable in the longitudinal direction of the vehicle body.

  As shown in FIG. 3, the lower rail 10 has inwardly bent walls 10b and 10b extending on both edges of a rail base portion 10a having a substantially U-shaped cross section that opens upward, and the upper rail 11 has a cross section that opens downward. Outwardly bent walls 11b and 11b are extended on both edges of the substantially U-shaped rail base portion 11a. The upper rail 11 is engaged with the lower rail 10 so that the outwardly bent walls 11b and 11b wrap around the lower ends of the bent walls 10b and 10b of the lower rail 10. A bracket 12 projects from the upper surface of the upper rail 11 near the rear end of the rail base 11a as shown in FIGS. 1 and 2, and a pivot 13 that pivotally supports the vicinity of the rear end of the side bracket 7 is provided. The bracket 12 is attached. Therefore, the seat cushion 2 is rotatably connected to the pivot 13 on the upper rail 11 via the side bracket 7.

  Further, a lower bracket 14 and an upper bracket extending inward of the left and right seat rails 5 are respectively provided on the upper surface of the upper rail 11 near the front end of the rail base portion 11a and the inner surface of the side bracket 7 close to the upper surface position. 15 is attached, and a damper 16 as a resistance generating means is attached between the brackets 14 and 15. As shown in FIGS. 3 and 4, the lower bracket 14 has a flat mounting base 14 a coupled to the upper surface of the rail base 11 a extending to the inside of the seat rail 5 (inside the left and right seat rails 5, 5). A channel portion 14b whose opening faces upward is integrally formed at the extended end. In the channel portion 14b, lower ends of a stopper member 17 and a damper 16, which will be described later, are disposed, and the lower ends thereof are coupled to opposing side walls of the channel portion 14b by pins 18 and 19, respectively.

  The stopper member 17 includes a base portion 17a coupled to the inner wall of the channel portion 14b of the lower bracket 14 by pins 18 and 19, and an L-shaped arm portion 17b that rises upward from the base portion 17a and is bent substantially horizontally at the top portion. And. During normal use of the vehicle seat 1, the lower surface of the upper bracket 15 comes into contact with the upper surface of the top of the L-shaped arm portion 17 b of the stopper member 17, and the load acting on the upper bracket 15 from the seat cushion 2 is This is transmitted to the upper rail 11 of the seat rail 5 via the lower bracket 14.

  The damper 16 has a cylinder member 20 having a lower end portion coupled to the channel portion 14b of the lower bracket 14 by a pin 18, and an upper end portion coupled to the upper bracket 15 while a lower end portion is slidable on the cylinder member 20. The piston member 21 is fitted to the upper bracket 15. The piston member 21 has a rod portion 21a whose upper end is screwed to the upper bracket 15 and a large diameter at the lower end of the rod portion 21a. A piston portion 21b slidably fitted to the inner peripheral surface. The cylinder member 20 obtains a damping action against an impact by sliding friction between the cylinder member 20 and the piston member 21, but the inner peripheral surface 20a of the cylinder member 20 is a gradual one whose inner diameter gradually decreases toward the upper side. When the piston member 21 is displaced upward relative to the cylinder member 20, the sliding resistance between the piston portion 21b and the cylinder member 20 is gradually increased. In the case of this embodiment, the cylinder member 20 and the piston member 21 are formed of a metal material.

  The upper bracket 15 includes a mounting base portion 15a coupled to the inner surface of the side bracket 7 and a support arm portion 15b extending in a substantially horizontal direction from the lower end of the mounting base portion. The upper end of the rod portion 21a of the piston member 21 is screwed.

  In the vehicle seat 1 configured as described above, the damper 16 is maximally contracted and the upper bracket 15 is a stopper member in a normal use state where no impact load is input from the rear of the vehicle body, as shown in FIGS. It is in direct contact with the upper surface of 17. In this state, the weight of the seat 1 and the passenger acts on the lower bracket 14 via the stopper member 17 and is supported by the upper rail 11 through the lower bracket 14.

  In this state, when an impact is input from the rear of the vehicle body and the center of gravity moves so that the upper body of the occupant seated on the seat 1 falls backward due to the impact, the seat cushion 2 lifts the front side with the pivot 13 as a fulcrum. Try to tilt to. At this time, when the front side of the seat cushion 2 is lifted as shown in FIGS. 5 and 6, the cylinder member 20 and the piston member 21 (viston part 21 b) of the damper 16 are relatively displaced, and at this time, the damping is caused by the frictional resistance between the members. Force is generated. As a result, the rapid movement of the seat 1 is gently limited, and the impact acting on the upper body of the occupant is absorbed. In particular, in the case of this embodiment, since the inner diameter of the cylinder member 20 is gradually narrowed toward the upper side, the friction damping action is increased as the tilt angle of the seat cushion 2 increases, and the magnitude of the input impact is increased. The optimum damping action according to the response can be obtained.

In this vehicle seat 1, the damper 16 that absorbs the input impact is supported by the lower bracket 14 bent downward from the upper rail 11 at the lower side at a position lower than the upper surface of the upper rail 11. A sufficient shock attenuation stroke of the damper 16 can be secured without incurring a height increase of 2.
Further, the damper 16 can be arranged on the lateral outer side of the seat rail 5, but when the damper 16 is arranged between the left and right seat rails 5 and 5 as in this embodiment, the damper 16 and its Since the attachment portion does not protrude outward from the seat width, it is possible to increase the degree of freedom of component layout in the vehicle interior. Furthermore, when the damper 16 is disposed between the two seat rails 5 and 5, the damper 16 and its mounting portion cannot be seen from the outside, and an improvement in appearance quality can be expected.

  Further, in the case of the vehicle seat 1, the vicinity of the rear end portion of the seat cushion 2 is pivotally supported by the upper rail 11 via the pivot 13. You can get movement.

  Further, in this embodiment, since the stopper member 17 that restricts the downward displacement of the front end portion of the seat cushion 2 is provided, an unnecessary load does not act on the damper 16 during normal use of the seat 1. Therefore, this makes it possible to prevent the damper 16 from deteriorating.

  In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary. For example, in the above embodiment, the damper 16 that is the resistance generating means is configured by the cylinder member 20 whose inner diameter is gradually narrowed and the piston member 21 that is slidably fitted to the cylinder member 20. The generating means is not limited to this configuration, and may be a damper using hydraulic pressure. However, when the damping force is obtained by the frictional resistance between the cylinder member and the piston member as in the above-described embodiment, the structure is simple and strong, so that the manufacturing cost can be easily reduced. Can be planned.

The side view which looked at the vehicle seat of one embodiment of this invention from the inside of the right and left seat rails. The enlarged side view by the side of the seat cushion of FIG. 1 which shows the same embodiment. Sectional drawing which follows the AA line of FIG. 2 which shows the same embodiment. The B arrow side view of FIG. 3 which shows the same embodiment. The side view corresponding to FIG. 2 at the time of the impact input which shows the same embodiment. The side view corresponding to FIG. 4 at the time of the impact input which shows the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle seat 2 ... Seat cushion 5 ... Seat rail 11 ... Upper rail (movable rail piece)
13 ... Pivot 16 ... Damper (resistance generating means)
17 ... Stopper member 20 ... Cylinder member 21 ... Piston member

Claims (1)

A seat cushion on which the occupant sits is installed on the car body via the seat rail,
Between the movable rail piece of the seat rail and the seat cushion, a resistance generating means for generating a damping resistance while allowing an upward displacement of the front portion of the seat cushion when an impact is applied from the rear of the vehicle body, and against the movable rail piece In the shock absorbing structure for a vehicle seat provided with a stopper member that regulates the downward displacement of the front portion of the seat cushion ,
A flat mounting base coupled to the upper surface of the movable rail piece, and a channel portion extending from the mounting base to the inside of the seat rail and having an opening facing upward at the end of the extending portion are formed. An impact absorbing structure for a vehicle seat, characterized in that a lower bracket is provided, and each lower end of the stopper member and the resistance generating means is disposed in a channel portion of the lower bracket .

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