JP2004106647A - Whiplash preventing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to maintain a state where a headrest is forward displaced when a vehicle gets rear-ended. <P>SOLUTION: A swinging unit 20 is rotatably supported on a seat back frame 10 via a one-way damper 30. A tensile coil spring 40 is hung between the seat back frame 10 and the swinging unit 20 and the swinging unit 20 is energized with rotation by this coil spring 40 so that the headrest 2 goes backward. The headrest 2 is maintained at a predetermined position by fastening the swinging unit 20 to a stopper 15. When the vehicle is struck from behind, an S spring 27 of the swinging unit 20 receives a load of an occupant and the swinging unit 20 is rotated so that the headrest 2 goes forward from the predetermined position, but the coil spring 40 is inhibited from rotating and returning the swinging unit 20 in the opposite direction by the one-way damper 30. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seat back structure having a whiplash preventing function.
[0002]
[Prior art]
When the vehicle is collided, the occupant is strongly pushed forward by the back or hips by the seat back, and the head moves relatively rearward, so that the neck is damaged, resulting in so-called whiplash. In order to prevent the whiplash, in the seat back structure described in Japanese Patent Application Laid-Open No. 10-181403, the swing unit is rotatably supported with respect to the seat back frame.
[0003]
The swing unit has a headrest at an upper portion and a load receiving portion at a lower portion for receiving a load from the waist or back of an occupant. A spring (biasing means) is hung between the swing unit and the seat back frame, and urges the swing unit so that the headrest moves rearward. A stopper (locking means) is provided on the seat back frame, and the stopper locks the swing unit against the spring so that the headrest is maintained at a predetermined position. I have.
[0004]
In the above configuration, when a rear-end collision occurs, the occupant is pushed forward by the seat back. In other words, the occupant moves rearward relative to the seat back and dive into the seat back. Then, the load receiving portion of the swing unit is displaced rearward by receiving the load of the occupant, and accordingly, the swing unit is rotated to displace the headrest forward. As a result, the headrest can receive the head of the occupant, which prevents the head from moving significantly backward.
[0005]
[Patent Document 1]
JP-A-10-181403 (FIG. 3)
[0006]
[Problems to be solved by the invention]
However, in the seat back structure having the above structure, when the occupant falls into the seat back with a lapse of time from the rear-end collision, the swing unit returns to the rotation by the elastic force of the spring, and the headrest is moved to a predetermined position. He returned to his position and was unable to continue to catch the occupant's head. Therefore, it was not possible to reliably prevent whiplash.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the whiplash prevention structure of the present invention
(A) a seat back frame,
(B) a swing unit rotatably supported by the seat back frame, having a headrest above the center of rotation, and having a load receiving portion below the center of rotation for receiving a load from an occupant;
(C) biasing means for rotationally biasing the swing unit so that the headrest is directed rearward;
(D) locking means for maintaining the headrest at a predetermined position by locking the swinging unit against the urging means;
(E) When the load receiving portion of the swing unit receives the load of the occupant, the swing unit rotates so that the headrest moves forward from the predetermined position, and then the swing unit is moved by the urging means. Rotation suppression means for suppressing rotation return,
It is characterized by having.
[0008]
In the above-described configuration, when the vehicle is collided, the swing unit rotates by receiving the load of the occupant by the load receiving unit, and displaces the headrest from the predetermined position to the front. Thus, the headrest can receive the head of the occupant. Further, when the occupant's descent becomes shallower with the passage of time from the rear-end collision, the swinging unit attempts to return to rotation by the urging means, but the rotation return of the rotation unit is suppressed by the rotation suppressing means. Therefore, the headrest can maintain the forward displacement position and continue to receive the head of the occupant. As a result, it is possible to reliably prevent the occupant from having whiplash.
[0009]
Preferably, the rotation suppressing means comprises a main body and a shaft supported by the main body and projecting from the main body, and the shaft is free to rotate in one direction with respect to the main body and suppresses rotation in the opposite direction. One of the main body and the shaft is fixed to the seat back frame, the other is fixed to the swinging unit, and the shaft is the center of rotation of the swinging unit with respect to the seat back frame. Become.
According to this configuration, the shaft of the rotation suppressing unit becomes the rotation center of the swing unit, so that the configuration can be simplified.
[0010]
If the rotation restraining means is constituted by a one-way damper, the forward displacement position of the headrest can be maintained by delaying the rotation return of the swing unit. The one-way damper can return the swinging unit to the original position after a long period of time, return the headrest to the predetermined position, and prepare for a rear-end collision.
[0011]
If the rotation suppressing means is constituted by a one-way clutch, the forward return position of the headrest can be reliably maintained by prohibiting the rotation return of the swing unit.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a whiplash preventing structure according to an embodiment of the present invention will be described with reference to the drawings. A seat for a vehicle includes a seat cushion (not shown), a seat back 1 attached to the seat cushion via an adjustment mechanism (not shown) so as to be reclined, and a headrest 2 provided on an upper portion of the seat back 1. (Shown only in FIG. 1). The seat back 1 has a built-in whiplash prevention structure.
[0013]
The skeleton of the seat back 1 is constituted by a seat back frame 10. As shown in FIG. 2, the seat back frame 10 is hung between a pair of side frames 11, a lower pipe 12 hung horizontally between lower ends of the side frames 11, and an upper end of the side frames 11. The upper pipe 13 has an inverted U-shape and has a substantially square shape when viewed from the front.
[0014]
Between the lower ends of the side frames 11, an S-spring 14 is mounted in front of the lower pipe 12. A stopper 15 (locking means) is attached to the center of the upper pipe 13. The stopper 15 includes a metal plate 15a fixed to the upper pipe 13 and a rubber receiving member 15b attached to a front surface of the metal plate 15a.
[0015]
The swing unit 20 is supported on the seat back frame 10 by a pair of left and right one-way dampers 30 (rotation suppressing means) so as to be rotatable in the front-rear direction. The swing unit 20 has a swing frame 21 serving as a skeleton. The swing frame 21 has an inverted U-shaped pipe 22 and a horizontal pipe 23 hung between the lower ends of the pipes 22, and has a substantially square shape when viewed from the front. The swing frame 21 has a smaller left and right width dimension and height dimension than the seat back frame 10, and is accommodated inside the seat back frame 10.
[0016]
The one-way damper 30 is a well-known one and will not be described in detail, but has a main body 31 and a shaft 32 supported by the main body 31 and protruding horizontally from the main body 31. The main body 31 is fixed to a position near the upper end of the left and right portions of the pipe 22 via a bracket 35. The shaft 32 penetrates the bracket 35 and the pipe 22 and protrudes toward the left and right portions of the seat back frame 10. On the other hand, brackets 36 are fixed to the left and right portions of the pipes 13 of the seat back frame 10, and the protruding ends of the shafts 32 are fixed to the hanging pieces 36a of the brackets 36 so as not to rotate. As a result, the swing frame 21 is rotatably supported by the seat back frame 10 about the shafts 32 of the pair of one-way dampers 30 as the center of rotation.
[0017]
A support cylinder 25 composed of a pair of square pipes is fixed to the upper horizontal portion (the horizontal portion of the pipe 22) of the swing frame 21 in a substantially upright state. The stay 2 a of the headrest 2 is inserted and fixed to the support cylinder 25 via a bush 26.
[0018]
Two S springs 27 (load receiving portions) vertically separated from each other are hung between brackets 28 between left and right vertical portions (vertical portions of the pipe 22) of the swing frame 21. These S springs 27 are arranged forward of the swing frame 21 by brackets 28.
[0019]
As is clear from the above description, in the swinging unit 20, the headrest 2 is located above the shaft 31 of the one-way damper 30, which is the center of rotation, and the S spring 27 is located below the shaft 31.
[0020]
Between the left and right portions of the seat back frame 10 (side frames 11) and the left and right portions of the swing frame 21, a pair of tension coil springs 40 (biasing means) are hung below the one-way damper 30. The swing unit 20 is rotationally biased by the coil spring 40 in a clockwise direction (first direction) in FIG. 1, that is, in a direction for moving the headrest 2 backward.
[0021]
The swing unit 20 is restricted from rotating clockwise by the horizontal portion on the upper side of the swing frame 21 hitting the stopper 15. Therefore, the headrest 2 is maintained at a predetermined position.
[0022]
The operation of the whiplash preventing structure having the above configuration will be described. When the vehicle is collided, the occupant's waist and back dives into the seat back 1 and pushes the S spring 27 of the swing unit 20 backward. As a result, the swing unit 20 rotates counterclockwise as shown by the imaginary line in FIG. 1, and as a result, the headrest 2 is displaced forward. By catching the occupant's head with the headrest 2 displaced forward, the head is prevented from moving significantly backward.
[0023]
In the one-way damper 30, the shaft 32 freely rotates (with little resistance) in the clockwise direction relative to the main body 31, so that it does not hinder the swing unit 20 from rotating in the counterclockwise direction. .
[0024]
As the time elapses from the rear-end collision, the occupant's dive into the seat back 1 becomes shallower. At this time, the swing unit 20 is rotationally urged in a clockwise direction, that is, in a direction to displace the headrest 2 rearward toward a predetermined position, by the elastic force of the extended coil spring 40. However, in the one-way damper 30, since a large resistance acts when the shaft 31 relatively rotates in the counterclockwise direction with respect to the main body 31, the swinging unit 20 returns to the original position at once by the force of the coil spring 40. It will not be a slow return. As a result, since the headrest 2 can maintain the position for receiving the occupant's head for a long time, the whiplash can be reliably prevented.
[0025]
Since the one-way damper 30 allows the swinging unit 20 to return to the rotation while being slow, the headrest 2 returns to the predetermined position and can be prepared for a rear-end collision.
[0026]
The present invention is not limited to the above embodiment, and can adopt various forms. For example, a one-way clutch may be provided instead of the one-way damper 30. Like the one-way damper 30, the one-way clutch has a main body and a shaft supported by the main body and protruding from the main body. In the one-way clutch, rotation of the swing unit such that the headrest is displaced forward from a predetermined position during a rear-end collision is freely permitted, and rotation in the opposite direction is prohibited. Therefore, the forward displacement position of the headrest can be reliably maintained.
[0027]
The rotation of the swing unit 20 in the clockwise direction can also be restricted by the support cylinder 25 supporting the headrest 2 hitting the horizontal portion on the upper side of the seat back frame 10. In this case, the horizontal portion on the upper side of the seat back frame 10 and the support cylinder 25 serve as locking means.
[0028]
【The invention's effect】
As described above, according to the present invention, when the vehicle is collided, the headrest is maintained in the forwardly displaced position and can continuously receive the occupant's head, so that the occupant can be surely whiplashed. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a side view of a seat back having a whiplash preventing structure according to an embodiment of the present invention.
FIG. 2 is a front view of the seat back structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seat back 2 Headrest 10 Seat back frame 15 Stopper (locking means)
20 Swing unit 27 S spring (load receiving part)
30 One-way damper (rotation suppressing means)
31 body 32 shaft 40 coil spring (biasing means)

Claims (4)

(A) a seat back frame,
(B) a swing unit rotatably supported by the seat back frame, having a headrest above the center of rotation, and having a load receiving portion below the center of rotation for receiving a load from an occupant;
(C) biasing means for rotationally biasing the swing unit so that the headrest is directed rearward;
(D) locking means for maintaining the headrest at a predetermined position by locking the swinging unit against the urging means;
(E) When the load receiving portion of the swing unit receives the load of the occupant, the swing unit rotates so that the headrest moves forward from the predetermined position, and then the swing unit is moved by the urging means. Rotation suppression means for suppressing rotation return,
An anti-whiplash structure comprising: The rotation suppressing means includes a main body and a shaft supported by the main body and protruding from the main body. The shaft is free to rotate in one direction with respect to the main body and is suppressed from rotating in the opposite direction. It is assumed that one of the main body and the shaft is fixed to the seat back frame, the other is fixed to the swinging unit, and the shaft is a center of rotation of the swinging unit with respect to the seat back frame. The whiplash prevention structure according to claim 1, wherein: 3. The whiplash prevention structure according to claim 2, wherein said rotation suppressing means comprises a one-way damper. 3. The whiplash prevention structure according to claim 2, wherein said rotation suppressing means comprises a one-way clutch.

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