JPH081149Y2 - Automotive airbag device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an airbag device for an automobile.

(Prior Art) Recently, in order to ensure the safety of an occupant at the time of a collision for an automobile, an airbag device has been receiving attention. This airbag device includes an inflator as a gas generation source (pressure generation source) and an airbag that is normally in a compressed state and inflated by receiving gas pressure generated by the inflator. Then, at the time of a collision, the inflator is detonated to generate a gas pressure, and the cushioning action of the airbag inflated in response to the gas pressure relieves the impact on the occupant during the collision.

In the above airbag device, a vent hole is provided to relieve the pressure in the airbag so that the airbag gradually expands after the collision with the occupant in order to more effectively absorb the impact at the time of the collision with the occupant. This vent hole is generally formed in the airbag itself.

In addition to the above, as shown in Japanese Utility Model Publication No. 61-85549,
It is also practiced to provide a band for restricting the shape of the airbag when inflated, that is, for restricting the amount of expansion (projection amount) toward the occupant. And, this band is usually fixed to the airbag itself at both ends thereof.

By the way, when forming a vent hole in an airbag, a patch cloth is applied to the peripheral edge of the vent hole in order to prevent a breakage from the vent hole. In order to prevent the band from peeling off from the airbag, a patch cloth may be applied to this portion as well. Then, this patch is attached by stitching.

(Problems to be solved by the invention) However, it is not preferable to form a vent hole in the airbag because the strength of the airbag itself is deteriorated, and gas escapes to some extent through the vent hole during the inflation process. It is also unfavorable in that the airbag is inflated quickly.

Of course, as mentioned above, the work of reinforcing the periphery of the vent hole and the fixed portion of the band with a patch cloth is quite troublesome, and some measures are desired in this respect as well.

Therefore, the object of the present invention is to have a vent hole and a band for regulating the shape of the airbag, and it is unnecessary to form the vent hole in the airbag itself or to be auxiliary even if it is formed. ,
Moreover, it is an object of the present invention to provide an automobile airbag device in which the number of reinforcing portions for the airbag can be minimized.

(Configuration of the Invention) In order to achieve the above object, the present invention has the following configuration. That is, an inflator having a mounting flange portion, an inflator as a gas pressure generation source, an inner hole into which the inflator is inserted, and a retainer to which the flange portion of the inflator is fixed at an inner peripheral edge portion of the inner hole. An airbag that is fixed to the retainer and that is inflated by receiving a gas pressure generated by the inflator; and a band that regulates the shape of the airbag when inflated, and the one end of the band is the While being fixed to the airbag, the other end is sandwiched and fixed between the retainer and the flange portion, and a gap formed between the retainer and the flange portion except for the other end portion of the band, A vent hole communicating the inside of the airbag with the outside air is provided. (Operation and effect of device) In the present invention configured as described above, the other end of the band is a retainer. To be fixed in a state of being sandwiched between the flange portion of the inflator. Therefore, it becomes unnecessary to particularly reinforce the other end of this band with an application cloth to the airbag.

In addition, since the vent hole is formed by utilizing the gap formed between the retainer and the flange portion of the inflator, it is unnecessary to form the vent hole in the airbag itself or it is a reinforcing member even if formed. OK. This not only leads to an improvement in the strength of the airbag, but is also preferable in reducing the reinforcing work.

The gas pressure generated by the inflator causes a considerable negative pressure in the gap portion, and the outside air is sucked through the gap portion. This brings about a decrease in the temperature of the gas generated from the inflator and an increase in the amount of gas supplied to the airbag, which is preferable from the viewpoint of the heat resistance of the airbag and the shortening of the inflation time of the airbag. Will be things.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings. In the embodiment, the case where the airbag device is incorporated in the boss portion of the steering handle is shown.

In FIG. 1, the handle H includes a wheel portion 1, a boss portion 2, and four spoke portions 3 connecting the both 1 and 2. An airbag unit AU is incorporated in the boss portion 2, and its bag cover (airbag cover) 4 is shown in FIG.

The airbag unit AU will be described with reference to FIGS. 2 and 3. 11 is an annular retainer, 12 is an inflator, 13 is a ring member, and 14 is an airbag. The retainer 11 is formed of a metal plate so as to have sufficient strength, and is fixed to a steering shaft (not shown) located in the boss portion 2 of the handle H by a fixture (not shown).

The inflator 12 serves as a gas pressure generation source, is located in the inner hole 11a of the retainer 11, and has an annular flange portion 1 thereof.
2a is located on the lower surface of the retainer 11. Between the retainer 11 and the flange portion 12, as will be described later, the end portion of the band 21 for shape regulation is interposed. The ring member 13 is positioned on the upper surface side of the retainer 11, and the inner peripheral edge portion of the opening of the airbag 14 is positioned between the ring member 13 and the retainer 11. Then, the members 13, 14, 1 are sequentially arranged from the top to the bottom in FIG.
In the state where 1, 21, 12a are stacked, these members are fastened together by a fixture 15.

Above the inflator 12 is a folded airbag 14
The inside of the airbag communicates with the upper portion of the inflator 12, that is, the gas generating hole 12b. The airbag 14 in the stored state is covered by the bag cover 4. A weakening line 4W is formed on the back surface of the back cover 4a, and when the airbag 14 is inflated, the weakening line 4W is subjected to the inflation pressure and easily broken from the weakening line 4W. This bag cover 4 like this
Is a front part that covers the airbag 14 in the stored state from the front.
4a and a side wall portion 4b that extends downward (front of the vehicle body) from the peripheral edge of the front surface portion 4a, and has a shape that opens downward. The tip of the side wall 4b of the bag cover 4 is
The retainer 11 is fixed to the outer peripheral edge of the retainer 11 via the plate 16.

The band 21 has a ring member 13 as shown in FIG.
A plurality of them are provided at intervals in the circumferential direction. The band 21 is formed into a flexible width, and one end of the band 21 is an airbag 14, more specifically, the airbag 14 when inflated.
The inner surface of the portion facing the occupant is sewn, and the sewn portion is reinforced by using a patch cloth 22. Also, band 21
As described above, the other end portion of the fixing member 1 is sandwiched between the retainer 11 and the flange portion 12a of the inflator 12, and the fixture 1
Fixed by 5.

The diameter of the portion of the inflator 12 located above the flange portion 12a in FIG. 2, that is, the gas generation hole 12b is slightly smaller than the diameter of the inner hole 11a of the retainer 11. Therefore, inside the airbag 14, except for the band 21 portion, the retainer 11 and the flange portion 12a of the inflator 12 are provided.
The air is communicated with the outside air through the gap (see FIG. 7) l. In this way, the gap 1 portion functions as a vent hole for communicating the inside of the airbag 14 with the outside air,
Therefore, no vent hole is formed in the airbag 14 itself.

In the above-described structure, the state shown in FIG. 2 is set in the normal state before the collision.

When a collision occurs, the collision is detected by a sensor (not shown), the inflator 12 is detonated, and gas pressure is generated from the gas generation hole 12b. As a result, the airbag 14 is inflated. In response to the inflation pressure of the inflating airbag 14, the bag cover 4 is broken along the weakening line 4W, and the airbag 14 is advanced to the front of the occupant in an inflated state to restrain the occupant.

The inflated airbag 14 receives an external force from the occupant, and in response to this external force, the pressure in the airbag 14 escapes via the gap 1 between the retainer 11 and the flange portion 12a of the inflator 12 to give an impact to the occupant. Alleviate more effectively.

Here, when the inflator 12 is detonated, the airbag
The flow of gas toward the inside 14 sucks the outside air through the gap 1. As a result, the temperature of the gas supplied into the airbag 14 is lowered, and the amount of gas supplied into the airbag 14 is increased. This increase in the amount of gas supplied into the airbag 14 and the fact that no vent hole is formed in the airbag 14 promptly inflate the airbag 14.

[Brief description of drawings]

FIG. 1 is a front view of a handle incorporating an airbag device according to the present invention. 2 is a sectional view taken along the line II-II in FIG. FIG. 3 is a partial cross-sectional perspective view of the airbag device shown in FIGS. 1 and 2. FIG. 4 is a simplified partial cross-sectional perspective view showing the state of the airbag and its shape regulating band in the inflated state. FIG. 5 is a plan view of the assembled state of the retainer, the inflator, and the band as seen from the airbag side. FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a sectional view taken along line VII-VII of FIG. H: Handle AU: Airbag unit 11: Retainer 11a: Inner hole 12: Inflator 12a: Flange 14: Airbag 15: Fixture 21: Band l: Gap

Claims (1)

[Scope of utility model registration request] 1. An inflator having a mounting flange portion, a gas pressure generating source, and an inner hole into which the inflator is inserted, the flange portion of the inflator being fixed to an inner peripheral edge portion of the inner hole. A retainer, an airbag fixed to the retainer and inflated by receiving the gas pressure generated by the inflator, and a band for restricting the shape of the airbag when inflated, the band having one end The part is fixed to the airbag, and the other end is sandwiched and fixed between the retainer and the flange part, and is formed between the retainer and the flange part except the other end part of the band. An air bag device for an automobile, characterized in that the gap is a vent hole that communicates the inside of the air bag with the outside air.