JPH0872660A - Impact mitigating device for head rest - Google Patents

Abstract

PURPOSE: To provide an impact mitigating device for a head rest where there is no fear to cause disorders when the head of an occupant is bent forward, and an exclusive sensor for detecting the rear end collision can be dispensed with. CONSTITUTION: An impact mitigating device for the occupant head in the rear end collision at a head rest 12 provided on the upper end of a seat in an automobile is provided with a head rest 12 which is splittable into a movable front part 12a and a rear part 12b to be fixed to the seat, a connecting means 11 to connect the front part 12a and the rear part 12b of the head rest to each other, and a mitigating means 8 which is built in the head rest 12, inflated to move the head rest front part 12a in the forward direction of the automobile, and mitigates the impact to the occupant head in collision. In addition, it is provided with a regulating means 19 to regulate the movement of the head rest front part 12a to the prescribed position, a collision detecting means, and trigger means 37, 7 which are connected to the collision detecting means and start the mitigating means 8 by a powder means when the electric signal of the rear-end collision is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing device for an automobile headrest.

[0002]

2. Description of the Related Art A conventional headrest of this type will be described with reference to FIG. Referring to FIG. 9, in a conventional mainstream seat of a vehicle, a headrest 2 attached to the upper end of the seat.
Is set so that when the occupant 3 is in the normal posture as shown in the figure, the occupant 3 has a distance d1 between the head 3a and the head 3a. The headrest 2 can be adjusted only in the height direction (arrow), and cannot be adjusted in the front-rear direction of the vehicle. Therefore, when the vehicle is stopped or close to a stop due to a signal or the like and is hit by another vehicle from the rear, the body of the occupant 3 is pushed forward at the same time as the vehicle, but the head 3a is as shown in the figure. In addition, (3a ') causes a flexion movement backward due to inertia, which often causes whipping damage.

Therefore, as a countermeasure against this, a rear impact detection device for detecting an impact from the rear is provided near the rear bumper of the vehicle, and an airbag device similar to that in the case of a frontal impact is provided on the headrest portion of the seat. When the impact detection device detects a rear collision, the impact mitigation device is proposed in which the airbag is deployed to receive the occupant's head and absorb the impact at the time of the collision (Japanese Patent Laid-Open No. 4-24).
See the back of No. 3647).

[0004]

However, in the above-described shock absorbing device, when the airbag is inflated forward beyond the normal position of the occupant's head 3a shown in FIG. 9, the occupant's head 3a is moved forward. There is a risk that it may be bent to cause a failure. Further, a sensor for detecting a rear collision is required.

The present invention has been made in view of such problems of the prior art, and an object thereof is to prevent the head of an occupant from being bent forward and causing an obstacle. An object of the present invention is to provide a headrest impact mitigation device that can omit a dedicated rear collision detection sensor.

[0006]

In order to solve the above problems, a headrest impact mitigation device according to the present invention is an impact mitigation device for an occupant's head at the time of a rear collision in a headrest provided at an upper end of a seat of an automobile. A headrest that can be split into a movable front portion and a rear portion fixed to a seat, a connecting means that connects the front and rear portions of the headrest, and the front portion of the headrest that is built in the headrest to increase the headrest front portion. Cushioning means for reducing the impact at the time of collision while moving to the front of the vehicle, and restriction means for restricting the movement position of the front portion of the headrest to a predetermined position,
The collision detecting means and the trigger means connected to the collision detecting means and activating the buffer means by the explosive means when receiving an electric signal of a rear collision are provided.

Further, the collision detection means may also serve as a front collision detection means.

Further, the connecting means comprises a hinge for connecting the lower part of the front surface of the headrest, the cushioning means comprises an airbag, and the restricting means connects the upper part of the front surface of the headrest. It is preferable that the string means is of a predetermined length.

[0009]

When the electric signal of the rear collision is received, the trigger means promptly activates the shock absorbing means by the explosive means, and the shock absorbing means is increased (inflated in the case of an airbag, extended in the case of mechanical means, etc.) and headrest. To move the front portion of the headrest to a predetermined position regulated by the regulation means before the head of the occupant bends backward. Therefore, by setting this predetermined position to the normal position of the occupant's head, the front portion of the headrest receives the occupant's head at the normal position to prevent the occupant's head from bending backward, preventing whiplash damage from occurring, and cushioning means. Reduces the impact of a collision transmitted from the seat.
Further, since the trigger means is activated by an electric signal input, if a semiconductor acceleration sensor and an electronic collision determination circuit are used, a rear collision and a front collision can be software-divided from the signs and waveforms of the acceleration signal. The collision detection means can be shared with the front collision detection means. In this case, a dedicated rear collision detection sensor is unnecessary.

Further, if the connecting means is constituted by a hinge for connecting the lower part of the split surface of the front and rear parts of the headrest, the movement of the front part of the headrest becomes one direction of the rotational movement with the hinge as a fulcrum, and the moving position is stabilized. Further, when the restricting means is constituted by a belt member of a predetermined length that connects the upper part of the split surface of the front and rear parts of the headrest, it is possible to restrict with a small force and a simple structure can be obtained.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vehicle top view showing a device arrangement of a first embodiment of a headrest impact absorbing device, FIGS. 2 and 3 are side views of a headrest which is an essential part of the present invention, and FIG. 4 is a rear view of the headrest. 5 and 5 are side views of the seat with the seat cover attached.

First, the structure will be described with reference to FIGS.
In FIG. 1, a trigger control device 6 is installed on, for example, an instrument panel 5 of a vehicle 10, and the trigger control device 6 includes a semiconductor acceleration sensor G, a collision determination circuit 102, first and second actuation circuits 103 and 104. Therefore, the first operating circuit 103 is provided in the driver airbag device 35 for frontal collision, which is installed in the central portion of the steering wheel 4, and the second operating circuit 104 is provided.
Is connected to a headrest impact absorbing device 36 installed on the headrest 12. The acceleration sensor G detects the acceleration and outputs it as an electric signal, and the collision determination circuit 102 determines the presence / absence of a collision from this acceleration signal. The acceleration sensor G detects the acceleration detected in the front collision and the rear collision. Since the directions are opposite and the collision waveforms are different, the collision determination circuit 102 processes the acceleration signal from the acceleration sensor G by software to detect the front collision and the rear collision while distinguishing between them. When a front collision is detected, the front collision detection signal 1 is sent to the first actuation circuit 103.
05, which causes the first actuation circuit 103 to output (energize) the electric signal S1 to the driver airbag device 35. When a rear collision is detected, a rear collision detection signal 105 is output to the second actuation circuit 104, which causes the second actuation circuit 104 to output (energize) an electric signal S2 to the headrest impact mitigation device 36. The semiconductor acceleration sensor G is
Since it is small, it is usually integrally incorporated as a part of the trigger control device 6. Therefore, in the automobile assembly plant, when the headrest impact mitigation device 36 is attached from the beginning of its assembly, it is used as both the airbag device 35 and the headrest impact mitigation device 36 as shown in the figure. Therefore, in this case, a dedicated rear collision detection sensor is unnecessary.

Further, in the figure, only the driver's seat airbag device 35 is illustrated as a safety device for a frontal collision, but a passenger seat airbag device and a seat belt pretensioner device may be provided together. In addition, the second operating circuit 1
The power source 04 can be shared with both the airbag and pretensioner actuation circuits when the headrest impact mitigation device 36 is installed from the production stage. , It is more convenient to share the power supply for the pretensioner operating circuit in terms of location of both.

As a collision detection sensor, in addition to the semiconductor acceleration sensor G shown in the figure, an electric / mechanical sensor (for example, a ball-in-tube type) that opens and closes an electrical contact by the movement of an inertial body at the time of collision is also a squib ( Since it is a type that outputs an electric signal to the trigger means), it can be used in the invention. However, in this case, since the moving direction of the inertial body is only one direction, it is impossible to use both the airbag device and the headrest shock absorber.
Each requires sensors mounted in opposite directions. Therefore, in this case, as shown by the chain double-dashed line, the electric / mechanical sensor 100 is installed as a rear-end collision detection sensor in the rear part of the vehicle where the rear-end collision is easily detected first, and the energization signal is transmitted via the operating circuit 101 to the headrest impact. It is configured to output to the mitigation device 36 (note that the front collision sensor is installed in the front part of the vehicle). In particular, this method is most suitable when the shock absorbing device for headrest 36 is retrofitted.

FIG. 2 shows the headrest 1 before the airbag is deployed.
2 represents the state. In FIG. 2, the headrest impact absorbing device 36 includes a headrest 12, a stay 13,
The airbag 8 is mainly composed of an airbag 8, a gas generator 7, plates 9, 10 and a hinge 11.

As shown in FIGS. 2 and 4, the headrest 12 has a pillow shape as a whole, and a U-shaped stay 13 is disposed inside the headrest 12, and a synthetic material such as urethane is formed around the stay 13. The pad 40 made of resin is used for this stay 13.
Is attached so as to cover the pad 40, and the pad 40 is covered with the skin member 39. Stay 13 is
Both tips are formed obliquely, and the tips are inserted and fixed in the seat. The headrest 12 includes a front portion 12a and a rear portion 12b in the longitudinal direction at the front-rear center of the vehicle.
The structure is divided into two parts. Headrest 1
2 The front surface 12c of the front portion 12a is a receiving surface for the head of the occupant. Plates 9 and 10 that cover substantially the entire surface of the headrest front and rear portions 12a and 12b are attached to the pad 40. The plates 9 and 10 are for receiving the pressure when the airbag 8 is inflated as shown in FIG. The plate 10 of the rear portion 12b is fixed to the stay 13 by means 41 such as welding and the like.
A recess 38 is formed in the lower part of 0, and the recess 38
At the lower end of the hinges 11, 1 on both sides of the headrest 12
1 is attached to both ends 13a and 13b of the stay 13 so as to extend in the lateral direction of the vehicle by welding or the like. The lower end of the plate 9 of the front portion 12a is connected to this hinge 11. A minute gap 42 is formed between the plates 9 and 10, and the airbag 8 is folded and accommodated in the gap 42 and the recess 38.

Further, in this recess 38, cylindrical gas generators 7, 7 are arranged on both sides of the headrest 12, and an end portion of the airbag 8 surrounds the gas generators 7, 7 so as to enclose the gas generators 7, 7. It is sealed in. That is, as shown in the AA cross-sectional view, the gas generator 7 is fitted into a cylindrical holding member 48 having a flange portion 48a, and the flange portion 48 is hollowed together with the end portion of the airbag 8 with a screw 16. The retainer 15 on the disc is fastened together and fixed to the retainer 1.
5 is attached to the stay 13 by welding or the like. The gas generator 7 includes a gas generating agent (not shown) and a squib 37.
(Trigger means) is incorporated, and the squib 37 incorporates an ignition agent and a heater. When the heater is energized and heated, the igniting agent is ignited, and the ignition causes the gas generating agent in the gas generator 7 to burn to generate a large amount of gas in a short time. Two lead wires 14 connected to the heater of the squib 37 from the gas generator 7 are led out to the outside along the stay 13, and are connected to the second operation circuit 104 of the trigger control device 6 of FIG. 1. It should be noted that the airbag 8 is not provided with a vent hole (ventilation hole) provided in the airbag for the driver's seat, and is held as it is after being inflated or the head of the occupant. The structure is such that gas does not escape until a load is applied. This is because the airbag 8 also serves as a cushion, but the first purpose is to prevent the back bending of the occupant's head by moving and holding the headrest front portion 12a at a predetermined position as described later. Because it is.

Further, the belt 19 having a predetermined length is
The headrest is attached between the front and rear portions 12a and 12b by crotch and is attached to the upper surface of the headrest by bonding or sewing. A string or the like may be used instead of the belt 19. As shown in FIG. 3, when the airbag 8 is inflated, the length of the belt 19 is set such that the front portion 12a of the headrest can move forward by a distance d1 which is about the size of a grip fist described in FIG. . Furthermore, at the upper end of the split surface, the headrest rear part 1
2b is provided with a clip 17 made of resin, and the front portion 12a is provided with an insertion hole 18 thereof.
Attached to. This clip 17 and insertion hole 1
In order to prevent the headrest front and rear parts 12a and 12b from being broken during normal operation when the airbag 8 does not operate, both are locked up to a predetermined pulling force, and when a pulling force of a predetermined value or more acts, both 8a and 12b come off. It is for breaking.

Next, the operation of the impact absorbing device for headrest will be described with reference to FIGS. In FIG. 1, when a rear collision occurs, the acceleration sensor G detects this and
The collision determination circuit 102 detects a collision based on this detection signal and outputs a rear collision signal 106 to the second actuation circuit 104, and the second actuation circuit 104 outputs an electric signal S2 to the impact mitigation device 36. In FIG. 2, when an electric signal is input, the squib 37 is ignited and the gas generator 7 is activated, and as shown in FIG.
Is removed, and the front portion 12a of the headrest rotates (arrows) about the hinge 11 as a fulcrum. And the headrest front part 1
When 2a moves forward by a predetermined distance d1 (interval of grip fist), it is restricted by the belt 19 and stops at that position. That is, the vehicle stops at a position close to the occupant's head. Here, since the airbag 8 deploys rapidly, the position of the occupant's head has hardly moved. Then, the headrest front part 12a receives the occupant's head at the position, and the shocks transmitted from the seat to the occupant's head due to the rear collision are mitigated by the pads of the airbag 8 and the headrest 12.
Therefore, the backward bending movement of the occupant's head as shown in FIG. 9 is prevented, and the occurrence of whipping damage is prevented. In this way, since the activation (trigger) of the airbag 8 is performed by the explosive means (squib 37, gas generator 7), the airbag 8 operates quickly and is deployed before the occupant's head moves almost. You can finish. Also, the belt 19
As a result, the moving position of the front portion 12a of the headrest is restricted to a predetermined position, so that there is no risk of causing an obstacle by bending the head of the occupant forward.

As shown in FIG. 5, the normal seat 1
Also, a seat cover 47 is hung on the headrest 12, but a fragile portion (hatched portion) 48 having a thin material is provided in the lateral direction at the center of the headrest portion in the front-rear direction so that the airbag can be deployed. When the headrest 12 is cracked, this portion is torn so that the impact mitigation device can be operated without any trouble even when the seat cover 47 is present. Also, instead of the fragile portion 48,
An opening may be formed in this portion in advance, and the opening may be stopped by a stopping means such as a hook or a button that is released by a slight force.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. 6 and 7 are side views of the headrest showing states before and after deployment of the airbag. 6 and 7 are different from FIG. 2 mainly in that link members 20 and 21 are provided instead of the hinge 11 of FIG. 2 as a connecting means of the headrest front and rear portions 12a and 12b, and the belt 19 of FIG. Instead of this, a stopper 27 is provided. That is, in FIGS. 6 and 7, a recess 58 for accommodating an airbag or the like is provided in the center of the split surface of the headrest rear portion 12b, and one end thereof is rotatably attached to the upper end portion of the plate 10 at the rear portion of the headrest (22). Is
The other end has a first link member 20 rotatably attached (23) to the center of the plate 9 at the front of the heddle, and one end rotatably attached (24) to a retainer at the rear of the headrest and the other end A second link member 21 that is rotatably axially locked (25) is provided at the lower end of the plate 9 at the front portion of the headrest (also symmetrically provided on the opposite side of the drawing). Further, a stopper having an abutment surface 27a that abuts against the link member 20 and limits the rotation of the link member 20 to a predetermined angle or less at the end portion of the first link member 20 on the headrest rear portion 12b side as shown in the drawing. 27 are provided. The predetermined angle of the first link member 20 is set to an angle at which the headrest front portion 12a moves forward by a predetermined distance d1 due to the inflation of the airbag 8. Therefore,
When the gas generator 7 is actuated and the airbag 8 is deployed, both link members 20, 21 rotate in the direction of the rotation arrow and the headrest front portion 12a moves forward, and when the front distance moves forward by a predetermined distance d1, the first link. The member 20 contacts the stopper 27 and stops. The clips 17 are provided at the upper and lower ends of the split surface. With such a configuration, the front surface 12c of the headrest 12a does not tilt forward as in the case of FIG. 3, and the occupant's head can be received at the original angle.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is a side view showing the state of the headrest before and after the airbag is deployed. 8 is different from FIG. 2 in that instead of the hinge 11 and the belt 19 shown in FIG. 2 as a connecting means and a regulating means, straps provided at both upper and lower ends of the split surface (also symmetrically provided on the opposite side of the paper surface). 2)
8 and 29 are used. That is, FIG.
In FIGS. 8A and 8B, a recess 68 for accommodating an airbag or the like is provided in the center of the split surface of the headrest rear portion 12b, and one end is stopped at the upper end of the plate 10 at the rear portion of the headrest (31), The other end is fastened to the upper end of the plate 9 at the front of the headrest (30). The first string 2
8 and a second string 29, one end of which is stopped at the lower end of the plate 10 at the rear of the headrest (33) and the other end of which is stopped at the lower end of the plate 9 at the front of the headrest (32). Specifically, the attachment positions of the straps 28 and 29 are set in consideration of the relation with the attachment position of the airbag 8 so that the front portion 12a of the headrest does not lower downward by its own weight and is lifted up. . The lengths of both straps 28 and 29 are set to such a length that the front portion 12a of the headrest can move forward by a predetermined distance d1 due to the inflation of the airbag 8. Therefore, when the gas generator is activated and the airbag 8 is deployed, the headrest front portion 12a
When the string moves forward by a predetermined distance d1, the straps 28, 2
It is regulated by 9 and stops at that position. With such a configuration, the stop position of the front portion 12a of the headrest is slightly unstable in the vertical and horizontal directions, but the configuration can be simplified.

Although the air bag is used as the cushioning means in the above embodiment, it may be replaced by a spring and a latch. In this case, it is necessary to quickly release (trigger) the latch by using explosive means such as a squib. With this configuration, the front portion of the headrest can be moved to a predetermined position before the head of the occupant bends backward, and the same effect as described above can be obtained.

[0024]

As described above, the shock absorbing device for headrest according to the present invention moves the front part of the headrest and the connecting means for connecting the front and rear parts of the breakable headrest to the front of the vehicle and reduces the impact at the time of collision. The shock absorber means, the restriction means for restricting the moving position of the front part of the headrest to a predetermined position, and the trigger means for activating the shock absorber means by the explosive means by the electric signal of the rear collision from the collision detection means. , The front part of the headrest is moved forward to a predetermined position while the head of the occupant is hardly moved, and the occupant's head is received while mitigating the impact at the time of a collision, preventing the occupant's head from bending backward. The occurrence of whipping damage can be prevented. Further, since the forward movement of the front portion of the headrest is restricted to a predetermined position, there is no risk of causing an obstacle by bending the occupant's head forward. Further, since the trigger means is activated by an electric signal, the collision detection means can be shared with the front collision detection means by using a semiconductor acceleration sensor and an electronic collision determination circuit, so that the collision detection means can be shared by software. A sensor for collision detection becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a vehicle top view showing a device arrangement of a first embodiment of a headrest impact absorbing device of the present invention.

FIG. 2 is a side view of a headrest that is a main part of the present invention.

FIG. 3 is a side view of a headrest that is a main part of the present invention.

FIG. 4 is a rear view of the headrest.

FIG. 5 is a side view of a seat with a seat cover attached.

FIG. 6 is a side view of a headrest according to a second embodiment of the present invention.

FIG. 7 is a side view of the headrest according to the second embodiment of the present invention.

FIG. 8 is a side view of a headrest according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a state of a conventional headrest.

[Explanation of symbols]

 G acceleration sensor (collision detection means) 3a occupant head 6 trigger control device (collision detection means) 7 gas generator (trigger means) 8 airbag (buffer means) 11 hinge (coupling means) 12 headrest 12a headrest front part 12b headrest Rear part 19 Belt (regulating means) 20 First link (connecting means) 21 Second link (connecting means) 27 Stopper (regulating means) 28 First string (connecting means, restricting means) 29 Second string (connecting means, Regulation means) 37 Squib (trigger means)

Front Page Continuation (72) Inventor Toshihiko Tanaka 7th floor, Tatsunuma Building, 1-3-19 Yaesu, Chuo-ku, Tokyo Sensor Technology Co., Ltd.

Claims (3)

[Claims] 1. A shock absorbing device for a passenger's head at the time of a rear collision in a headrest provided at an upper end of a seat of an automobile, which is capable of being split into a movable front part and a rear part fixed to a seat. A headrest, a connecting means for connecting the front and rear portions of the headrest, a cushioning means that is built in the headrest to move the front portion of the headrest forward of the vehicle and reduce the impact of the occupant's head during a collision, The headrest front part is provided with a restriction means for restricting the moving position to a predetermined position, a collision detection means, and a trigger means connected to the collision detection means and activating the buffer means by the explosive means when receiving an electric signal of a rear collision. A shock absorbing device for a headrest, which is characterized by that. 2. The headrest impact mitigation device according to claim 1, wherein the collision detection means also serves as a front collision detection means. 3. The connecting means comprises a hinge for connecting the lower part of the split surface of the front and rear parts of the headrest, the cushioning means comprises an airbag, and the restricting means connects the upper part of the split surface of the front and rear parts of the headrest. The headrest impact mitigating device according to claim 1 or 2, wherein the impact mitigating device comprises a belt member having a predetermined length.