JPH08156730A - Air bag for vehicle - Google Patents

Abstract

PURPOSE: To absorb energy of a crew side fabric in an ejecting direction by shifting the timing of breakage of a sawn part from a part to a part of an air bag so as to always apply tension to the outer peripheral part of the air bag. CONSTITUTION: Of a plurality of substantially radial sawn parts 6a to 6c subjected to controlled sewing 5, one 6a has a breakage-proof strength which is set so as to be weaker than that of the others.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag bag body such as an airbag device for a driver's seat, and more particularly to a vehicle airbag in which a deployment shape is controlled by a control sewing applied to the airbag. .

[0002]

2. Description of the Related Art An air bag device is a device for protecting an occupant by instantaneously expanding an air bag in the event of a vehicle collision, and usually includes an inflator which is a gas generator and an air bag which is inflated by gas of the inflator. Is equipped with.

The airbag is produced, for example, by sewing an inflator side cloth having a substantially circular opening for attaching an inflator and an outer peripheral edge portion of an occupant side cloth having substantially the same shape as the cloth. There are many.

By the way, an airbag may be provided with a strap called a tether in order to make the airbag inflated into a predetermined shape more quickly. The strap is located near the center of each of the inflator side cloth and the passenger side cloth of the airbag. The airbags are connected to each other so that when the airbag is deployed, the airbag can be formed into a predetermined deployment shape more quickly. However, since the strap is generally attached to the inner surface of the airbag, and the attachment requires a technique, there is a disadvantage that it requires man-hours and time, which is a factor of increasing the cost of the airbag. In addition, since the strap is bulky, the weight of the airbag and the package volume increase.

[0005]

Therefore, in order to solve the above-mentioned problems, sewing as a substitute for the tether is considered as a means for omitting the strap. This sewing is
This is called Tear Seam, which absorbs energy by breaking the sewing thread when the airbag is deployed. By controlling sewing, the fabric on the passenger side of the airbag and the fabric on the inflator side are broken by a prescribed deployment pressure. When the air bag is sewn up and sewn, the tear seam is ruptured and energy is absorbed in the direction in which the occupant side cloth pops out to control the deployment behavior.

However, in the conventional tear seam described above, since the sewing threads are set to break at substantially the same time in the plurality of stitched portions subjected to the control sewing, the energy absorption in the pop-out direction of the occupant side cloth is prevented. It is also considered that the expansion behavior is not sufficiently controlled and the expansion behavior is not sufficiently controlled.

The present invention copes with the actual situation as described above, and by setting the order of breaks in the control sewing, the airbag is expanded from the outer peripheral side and the energy of the cloth on the occupant side at the time of the expansion is set. Is intended to be absorbed sufficiently.

[0008]

That is, the feature of the airbag of the present invention which meets the above-mentioned object is that an inflator side cloth having an opening for attaching an inflator and an occupant whose outer peripheral portion is sewn to the inflator side cloth. In a vehicle airbag in which side fabrics are sewn together by a control sewing that breaks due to a predetermined deployment pressure of the airbag, and the deployment of the outer peripheral side of the airbag is promoted, the above-mentioned control sewing is performed in a substantially radial direction. A plurality of sewn portions are formed so as to divide the airbag substantially equally around the opening.
One is formed weaker than the other sutures.

Further, in the airbag of the present invention,
It is also possible to make adjacent stitches weaker than the rest of the weakly formed stitches so as to make the order of the breaking order clearer.

[0010]

When the airbag device is activated, the inflator gas is blown out toward the occupant side cloth in the airbag. However, in the airbag of the present invention, since the inflator side cloth and the passenger side cloth are sewn by the control sewing, the passenger side cloth does not immediately pop out, and the inflator gas first flows to the side of the airbag. When the internal pressure rises to some extent, the sewn portion of the weakest portion is first broken, and a large amount of inflator gas reaches the outer peripheral portion through this portion.

Then, when the inner pressure of the airbag further rises, the control sewing stitching portions on both sides of the broken stitching portion are subsequently broken, and similarly a large amount of inflator gas reaches the outer peripheral portion. The control sewing stitches that fit together are sequentially broken.

That is, according to the present invention, the breaking strength of the controlled stitching stitching portion is adjusted as described above, and the breaking timing of the stitching portion is shifted for each portion, so that the outer circumferential portion of the airbag is as described above. Always let the inflator gas flow toward the air bag, so that tension is always applied to the outer peripheral portion of the airbag, and as a result, deployment from this outer peripheral portion is accelerated and at the same time, sufficient energy is absorbed in the pop-out direction of the occupant side cloth. Is possible.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view of an airbag according to a first embodiment of the present invention seen from the side of an inflator cloth, FIG. 2 is the same as that of the second embodiment seen from the same side, and FIG. 3 is a second embodiment. 3 is a cross-sectional view of the airbag of FIG.

As shown in the drawings, the airbag for the driver's seat in each of the above embodiments has a circular opening 3 for attaching an inflator.
The inflator side cloth 1 having a vent hole 4 and an outer peripheral edge portion of an occupant side cloth 2 having substantially the same outer shape as the cloth 1 are sewn together, and the opening 3 has a cylindrical inflator. A head (not shown) is inserted.

In each of the above embodiments, the inflator-side cloth 1 and the occupant-side cloth 2 are sewn by the control sewing 5 which is broken by the predetermined inflation pressure of the airbag, as shown in FIGS. It is designed to accelerate the deployment of the airbag on the outer peripheral side.

Sewn portions 6a to 6 to which the control sewing 5 is applied.
c is formed in a substantially radial direction so as to divide the airbag into equal parts centering on the opening 3.
In the embodiment, three parallel control sewing pieces 5 are used as one set to form four radial stitching portions 6a to 6c. In the second embodiment, three concentric circular arc control sewing pieces 5 are formed. Similarly, four sewn portions 6a to 6c in one radial direction are formed as one set.

In the embodiment of the present invention, one of the plurality of stitched portions 6a to 6c is the other stitched portion 6a.
The breaking strength is set to be weaker than that of b and 6c. The two stitched portions 6b adjacent to each other on both sides of the weakened stitched portion 6a are set to have a lower breaking strength than the remaining stitched portion 6c.

The strength of the breaking strength of the stitched portions 6a to 6c can be easily determined by the strength and weakness of the sewing thread, the number of stitches and the length of stitches.

In the airbag of each of the above-mentioned embodiments of the present invention, however, the inflator side cloth 1 and the occupant side cloth 2 are sewn by the control sewing 6a to 6c.
Even if the inflator gas blown toward the occupant side cloth 2, the occupant side cloth 2 does not immediately pop out (FIG. 4B), and when the internal pressure rises to some extent, the sewn portion 6a of the weakest part is first The inflator gas ruptures and reaches the outer peripheral portion through the ruptured suture portion 6a (FIG. 4).
C).

Then, when the inner pressure of the airbag further rises, the control sewing stitched portions 6b on both sides of the broken stitched portion 6a are subsequently broken, and the inflator gas reaches the outer peripheral portion in the same manner (see FIG. ), The control stitching portion 6c remaining at the end is broken to complete the airbag deployment (FIG. 4).
E).

In other words, in the embodiment of the present invention, the breaking strength of the controlled stitching stitching portions 6a to 6c is adjusted as described above, and the breaking timing of the stitching portions 6a to 6c is shifted for each part, so that As described above, the inflator gas is always directed toward the outer peripheral portion of the bag, whereby tension is constantly applied to the outer peripheral portion of the airbag, and as a result, the deployment from the outer peripheral portion is accelerated, and at the same time, the occupant's side cloth is ejected It becomes possible to fully absorb the energy to.

Incidentally, FIG. 5 is a cross-sectional view showing the conventional unfolding behavior provided with a strap, but the unfolding behavior of the embodiment of the present invention shown in FIG. 4 is almost the same.

Although the embodiment of the present invention has been described above, a single or a plurality of control stitches may be used to form one stitching portion. If there are a plurality of stitches, the stitching may be performed independently or as shown in FIG. It is possible to apply continuously as shown in FIG.

[0025]

As described above, the vehicle airbag of the present invention is an airbag in which the inflator-side cloth and the occupant-side cloth are sewn by the control sewing that is broken by the deployment pressure of the airbag. A plurality of sewn substantially radial sewn portions are formed, and one of these sewn portions is formed.
One has a lower rupture strength than the other sutured portions, and by shifting the timing of the rupture of the sutured portions for each part, the inflator gas is sequentially directed toward the outer peripheral portion of the airbag. Tension is always applied to the outer peripheral part of the airbag, and as a result, it is possible to accelerate the deployment from this outer peripheral part and sufficiently absorb the energy in the pop-out direction of the occupant side fabric, which is equivalent to the conventional airbag with a strap. Realize the deployment behavior and substitute it,
The remarkable effect of providing a low-cost, low-volume airbag without the strap is provided.

[Brief description of drawings]

FIG. 1 is a plan view of an airbag according to a first embodiment of the present invention viewed from a fabric on an inflator side.

FIG. 2 is a plan view of an airbag according to a second embodiment of the present invention seen from a fabric on an inflator side.

FIG. 3 is a sectional view of an airbag according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing the deployment behavior of the airbag of the embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a deployment behavior of a conventional airbag with a strap.

[Explanation of symbols]

 1 inflator side cloth 2 occupant side cloth 3 opening 4 vent hole 5 control sewing 6a-6c stitching part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Miyauchi No. 3 Ikugayama, Uchikoshi, Miyoshi-cho, Nishikamo-gun, Aichi Prefecture Toyo Tire & Rubber Co., Ltd. Automotive Parts Technology Center (72) Hidehito Sogi Nishikamo-gun, Aichi Prefecture 3 Yoshigayama, Mitsuki-cho, Ikayama, Toyo Tire & Rubber Co., Ltd. Automobile Parts Technology Center (72) Inventor Toru Ozaki 3 Yoshioka, Nishikamo-gun, Aichi Prefecture, 3 Okayama, Toyo Tire & Rubber Co., Ltd. Inside the surgery center

Claims (2)

[Claims] 1. An inflator-side cloth having an opening for mounting an inflator, and an occupant-side cloth having an outer peripheral portion sewn to the inflator-side cloth are sewn by a control sewing machine which is ruptured by a predetermined deployment pressure of an airbag. In an airbag for a vehicle that is sewn to promote the deployment of the outer peripheral side of the airbag, a plurality of sewn portions in the substantially radial direction subjected to the control sewing are provided, and the airbag is divided into approximately equal parts around the opening. And one of the plurality of sewn portions is formed to be weaker than the other sewn portions. 2. The airbag for a vehicle according to claim 1, wherein the stitched portion adjacent to the weakened stitched portion is formed weaker than the remaining one.