JPH05162608A - Vent hole structure of air bag body - Google Patents

Abstract

PURPOSE:To obtain an air bag body vent hole structure that enables an air bag body to inflate in a instant and to absorb energy efficiently. CONSTITUTION:A side cloth 40 is superposed on the fringe portion of a vent hole 41 of the side cloth 40 of an air bag body along the inflating direction of the air bag body causing the vent hole 41 to contract. The vent hole 41 may be completely closed. Furthermore, a superposed portion 49 being sewed up on the air bag body by a sewing thread 45 in the inflating direction of the air bag body, causes the vent hole 4 to become fully opened as the sewing thread is cut off by means of the tension working on the side cloth 40 when the air bag body 26 approaches a maximum inflated condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag bag gas venting hole structure for an air bag device mounted on an automobile or the like.

[0002]

2. Description of the Related Art In recent years, an airbag device has been proposed as a device for protecting an occupant in an emergency of a vehicle.

This airbag device protects an occupant by inflating the airbag bag body by inflating the airbag bag body with an inflator when the vehicle decelerates suddenly and inflating the airbag bag to advance to the front or side of the occupant. Is.

Therefore, in this airbag device,
It is necessary to instantly inflate and deploy the airbag bag, and it is necessary to increase the initial internal pressure of the airbag bag to some extent. However, if the internal pressure of the airbag bag is too high, effective energy absorption cannot be achieved, so after the airbag bag is inflated, the gas is gradually released from the gas vent hole provided in a part of the airbag bag, Prevents excessive rise in internal pressure.

However, as described above, with the structure in which a gas vent hole is provided in a part of the airbag bag to prevent the internal pressure from rising excessively, the internal pressure of the airbag bag does not reach a predetermined value. Since gas escapes from the gas vent hole, the gas is wasted, and in order to deploy the airbag bag instantly,
It is necessary to supply gas in anticipation of the amount of gas that will escape from the gas vent hole.

Japanese Unexamined Utility Model Publication No. 2-132554 discloses an example of an air bag body gas vent hole structure for improving this.

As shown in FIGS. 6 (A) and 6 (B), in this air bag body gas vent hole structure, the gas vent hole 74 provided in the side cloth 72 of the air bag body 70 is The sheet 76 is closed by the seat 76, and when the internal pressure of the airbag bag 70 exceeds a predetermined value, the sheet 76 breaks to prevent the internal pressure of the airbag bag 70 from excessively rising. There is.

[0008]

However, in this air bag body gas venting hole structure, in order to rupture the seat 76 by the gas pressure with which the air bag body 70 is filled from the inflator 78, the amount of gas is changed. It needs to be increased significantly. Therefore, in actuality, the occupant abuts on the airbag bag body 70, whereby the airbag bag body 7
When the internal pressure of 0 becomes a predetermined value or more, the sheet 76 breaks.

Therefore, in this air bag body gas vent hole structure, when the occupant abuts the air bag body 70, the gas vent hole 74 is still blocked by the seat 76, and the energy cannot be absorbed efficiently. There is.

In consideration of the above facts, the present invention provides an air bag bag gas venting hole structure capable of instantaneously deploying the air bag body and effectively absorbing energy by the air bag body. The purpose is to obtain.

[0011]

An air bag bag degassing hole structure according to a first aspect of the present invention is provided in the air bag body to prevent an excessive increase in internal pressure of the air bag. Body gas vent hole structure, in the peripheral portion of the gas vent hole, the airbag bag body is overlapped along the deployment direction when the airbag bag body is deployed to reduce or close the gas vent hole, and the overlapping portion is formed. It is characterized in that they are joined together along the deployment direction so that the joining is released when the air bag body approaches the maximum deployed state.

[0012]

According to the air bag body gas vent hole structure of the invention described in claim 1, the gas vent hole is along the deploying direction until the air bag body starts to deploy and approaches the maximum deployed state. Polymerized, bonded, reduced or occluded. Therefore, since the amount of gas that escapes from the gas vent hole is small or nonexistent, the airbag bag can be instantly deployed.

On the other hand, when the airbag bag approaches the maximum deployed state, the overlapping portion is pulled along the deployment direction by the deployment force of the airbag bag. As a result, the connection that connects the overlapping portion along the deployment direction of the airbag body is released, and the gas vent hole, which has been reduced or blocked, is fully opened. Therefore, when the occupant comes into contact with the airbag bag in the maximum deployed state, the gas vent hole is fully opened, and the gas is easily released from the gas vent hole, so that the airbag bag can effectively absorb energy. Can be done.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In the figure, an arrow FR indicates a front direction of the vehicle body, and an arrow UP indicates an upward direction of the vehicle body.

As shown in FIG. 5, in the vehicle body 10, an instrument panel 16 is arranged in front of the passenger seat 14 in the vehicle interior 12. An airbag device 18 is mounted on the back side of the instrument panel 16.
The airbag device 18 has a longitudinal shape in the vehicle width direction, and the airbag device 18 of the instrument panel 16 is provided.
The portion opposite to is a rectangular airbag cover portion 20 which is elongated in the vehicle width direction.

As shown in FIG. 3, the airbag device 18
The cross-sectional shape of the case 22 as viewed from the vehicle width direction is substantially U-shaped, and the case 22 has an opening 24 formed obliquely upward and rearward of the vehicle body. At the inner peripheral portion of the opening 24, the opening edge portion 27 of the air bag body 26 is provided with the bolt 2
It is fixed by 8 and nut 30. Further, the retainer 3 which is elongated along the opening 24 of the case 22 is provided between the opening edge 27 of the airbag 26 and the bolt 28.
2 is provided, and seals the connecting portion between the opening 24 of the case 22 and the opening edge 27 of the airbag 26.

As shown in FIG. 2, the airbag bag body 26.
Is provided between the two side cloths 40 forming the side surface of the airbag body 26 and the two side cloths 40,
The airbag bag 26 includes an upper portion 26A, a lower portion 26B, and an intermediate cloth 42 that constitutes an occupant side portion 26C.

As shown in phantom in FIG. 3, side cloth 40
As for the cutting shape of the case 22,
It has a substantially trapezoidal shape whose side is the short side 40B. Also,
A circular gas vent hole 41 is bored in a substantially central portion of the side cloth 40, and a reinforcing sewing 43 is provided in a peripheral edge portion of the gas vent hole 41.

As shown in FIG. 1A, the gas vent hole 4
1, the side cloth 40 is attached to the air bag body 2 at the peripheral portion of
6 are aligned along the developing direction (direction of arrow F in FIG. 1A), and the gas vent hole 41 is reduced. In addition,
The gas vent hole 41 may be completely closed. Further, the overlapping portion 49 is sewn by a suture thread 45 along the expanding direction of the airbag bag body 26, and the airbag bag body 26 of the suture thread 45 is in a maximum expanded state (state shown by a solid line in FIG. 3).
1B, that is, when the phantom line in FIG.
As shown in FIG. 5, the gas vent hole 41 is designed to be fully opened.

As shown in FIG. 4, the shape of the intermediate cloth 42 is such that the central portion in the longitudinal direction constituting the occupant side portion 26C of the airbag bag body 26 is wide, and the airbag bag body 26 has a wide width.
The both ends of the upper part 26A and the lower part 26B in the longitudinal direction are in the form of strips whose width is gradually narrowed. Further, the widthwise end portion 42A of the intermediate cloth 42 is sewn to the outer peripheral edge portion of the side cloth 40 excluding the short side 40B.

As shown in FIG. 3, a cylindrical inflator 34 is fixed in the case 22 near the bottom portion 22A along the vehicle width direction. The inflator 34 is filled with a gas generating substance, and the gas generating substance is provided with an ignition means. Therefore, when the vehicle body 10 rapidly decelerates by a predetermined value or more, the gas generating substance is ignited through the igniting means to start combustion by the operation of the acceleration sensor (not shown), and the gas generated by the combustion causes The airbag bag body 26 accommodated in the state of being folded in the vicinity of the opening portion 24 of 22 swells and pushes open the airbag cover portion 20 of the instrument panel 16 to deploy it in the vehicle compartment.

Next, the operation of this embodiment will be described. When the vehicle body 10 rapidly decelerates significantly, the inflator 3
Gas is generated from No. 4, and the air bag bag 26 is inflated when the air bag bag body 26 is filled with the gas, ruptures the air bag cover portion 20 of the instrument panel 16, and rapidly expands into the vehicle compartment.

In this case, in the present embodiment, as shown in FIG. 1 (A), the air bag body 26 starts to deploy and until the air bag body 26 approaches the maximum deployed state (state shown by the solid line in FIG. 3). The holes 41 are overlapped, sewn and shrunk along the deployment direction. Therefore, the amount of gas that escapes from the gas vent hole 41 is small, and the airbag bag body 26 can be instantly deployed.

On the other hand, when the airbag bag body 26 approaches the maximum deployed state and reaches the state of the imaginary line in FIG. 3, the deployment force of the airbag bag body 26 causes the overlapping portion 49 of the side cloth 40 to deploy (FIG. 1). (A) is pulled along the arrow F direction). As a result, the suture thread 45 that sews the overlapping portion 49 along the deployment direction of the airbag bag is cut, and the reduced gas vent hole 41 is fully opened (the state of FIG. 1B).
Becomes

Therefore, when the occupant comes into contact with the airbag bag body 26 in the maximum deployed state (state shown by the solid line in FIG. 3), the gas vent hole 41 is fully opened, and the gas vent hole 41 can easily be used to vent gas. Since the air bag is removed, energy absorption by the airbag bag body 26 can be effectively performed.

In the above embodiment, the overlapping portion of the gas vent hole 41 is formed by stitching. However, when the airbag bag is expanded into a predetermined shape, the tension is exerted on the airbag bag to easily release the connection. It may be a bonding method such as adhesion. Further, although the gas vent hole 41 is formed in the side cloth 40, the position of forming the gas vent hole is not limited to this, and as shown by phantom lines in FIGS. 3 and 4, the airbag bag of the intermediate cloth 42 is formed. The gas vent hole 51 may be formed at the upper or lower position when the body is deployed. Further, in the above embodiment,
Although the airbag bag body 26 is made of a cloth material, the material of the airbag bag body 26 is not limited to the cloth material. Further, in the above-described embodiment, the side cloth 40 and the intermediate cloth 42 of the airbag bag 26 are sewn into a bag shape, but the side cloth 40 and the intermediate cloth 42 are bonded by another bonding method such as adhesion. The shape of the airbag bag 26 is not limited to the above embodiment.

[0027]

According to the present invention, the air bag body is overlapped at the peripheral portion of the gas vent hole along the deployment direction when the air bag body is deployed, and the overlapping portion is joined along the deployment direction to form the air bag body. Since the structure is such that the coupling is released when approaching the maximum deployed state, the airbag bag can be instantly deployed, and the energy absorption by the airbag bag can be effectively performed. Have an effect.

[Brief description of drawings]

FIG. 1A is a schematic view showing a stitched state of an air bag body gas venting hole structure according to one embodiment of the present invention, and FIG. 1B is an air bag bag gas venting according to one embodiment of the present invention. It is a schematic diagram showing a fully open state of a hole structure.

FIG. 2 is a perspective view showing the airbag bag deployed state of the airbag device to which the airbag bag gas venting hole structure of the embodiment of the present invention is applied, as seen obliquely from the rear of the vehicle body.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

4 is a sectional view taken along line 4-4 of FIG.

FIG. 5 is a perspective view of an instrument panel equipped with an airbag device to which an airbag bag gas venting hole structure according to an embodiment of the present invention is mounted, as seen from diagonally rearward of the vehicle body.

FIG. 6A is a perspective view showing an airbag device to which a conventional airbag bag gas vent hole structure is applied;
FIG. 6B is a sectional view taken along the line BB of FIG.

[Explanation of symbols]

 18 Airbag device 26 Airbag body 40 Side cloth 41 Gas vent hole 45 Suture thread 49 Overlapping part

Claims (1)

[Claims] 1. An air bag bag gas vent hole structure for preventing an excessive increase in internal pressure of the air bag bag provided in the air bag bag body, wherein the air bag bag body is filled with air at the periphery of the air bag hole. When the air bag body approaches the maximum deployed state by overlapping or shrinking or closing the degassing hole along the deploying direction when the bag body is deployed and connecting the overlapping portion along the deploying direction. An air bag body gas vent hole structure characterized in that the connection is released.