JP2001071849A - Air bag system for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lead an expanding direction of a main expanding portion to an occupant's side, by providing a small capacity sub-expanding portion and a large capacity main expanding portion which are branched from each other and positioning the sub-expanding portion on a front window panel side to be brought into contact with the front window panel at a time of its expansion. SOLUTION: An air bag 6 comprises a small capacity sub-expanding portion 16 and a large capacity main expanding portion 17, which are branched from a gas inlet port 14. The sub-expanding portion 16 is positioned on a front window panel 2 side. By the constitution, at a time of expansion, the small capacity sub-expanding portion 16 expands prior to the main expanding portion 17. At the time, since the sub-expanding portion 16 has a small capacity, the sub- expanding portion 16 is brought into contact with the front window panel 2 from a lower side to form a wall. The sub-expanding portion 16 expanded on a side of the front window panel 2 functions as a wall for the main expanding portion 17 expanded following the sub-expanding portion 16. Thereby, the expanding direction of the main expanding portion 17 is lead to an occupant' s side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for an automobile, and more particularly to an airbag device for a passenger seat.

[0002]

2. Description of the Related Art An instrument panel located below a front window panel is provided with an airbag module (Japanese Patent Laid-Open No. Hei 8-26 is a similar technique).
No. 8213). This airbag module is
In a case in which an opening is closed by a cleavable cover, a folded airbag and an inflator for blowing gas into the airbag are housed. And, by the gas ejected from the inflator at the time of collision,
An airbag cleaves the cover and deploys from there into the cabin to protect occupants.

[0003] In the case of this type of airbag device, it is known that the deployment of the airbag to the rear occupant side is more excellent in terms of occupant protection than the deployment to the front window panel side directly above. Have been. For this purpose, a tether belt is provided inside the airbag as conventionally known in U.S. Pat. No. 5,746,447 and the like, so that the tether belt prevents the airbag from deploying upward and deploys it toward the occupant. Leading.

[0004]

However, in such a conventional technique, since the tether belt is provided inside the airbag, the volume of the airbag becomes large.
As the size of the airbag increases, the size of the inflator for inflating the airbag also increases, which causes an increase in the weight of the vehicle. In addition, since the tether belt is provided inside the airbag, sewing work of the airbag is also troublesome.

The present invention has been made by paying attention to such a conventional technique, and it is possible to guide the deployment direction of the airbag toward the occupant without providing a tether belt in the airbag. An apparatus is provided.

[0006]

According to the first aspect of the present invention,
An airbag module is formed by storing a folded airbag and an inflator for blowing gas into the airbag in a case whose opening is closed by a cleavable cover, and forming the airbag module on the front. An airbag device for an automobile installed on an instrument panel below a window panel, in which an airbag inflated in a case cleaves a cover and deploys to a vehicle interior side, wherein the airbag is connected to a gas inlet for an inflator. A small-volume sub-inflation portion and a large-capacity main inflation portion are branched and formed. The sub-inflation portion is located on the front window panel side and abuts on the front window panel during inflation, and the main inflation portion is provided. Is characterized by being located on the occupant side.

According to the first aspect of the present invention, since the sub-inflation portion has a small volume, the sub-inflation portion is quickly filled with gas, so that the sub-inflation portion expands and develops before the main inflation portion, Touch the front window panel from below. Therefore, the sub-inflation portion abutting on the front window panel acts as a “wall” in the deployment process, guiding the direction of the main inflation portion to be deployed later to the occupant, and improving the occupant protection performance by the airbag. Since the sub-inflation portion has a small capacity, it does not wither while the main inflation portion is inflated.

According to a second aspect of the present invention, there is provided the airbag apparatus for an automobile according to the first aspect, wherein the main inflating portion and the sub-inflating portion inflate substantially in a V shape in a side view. Features.

According to the second aspect of the present invention, since the main expansion portion and the sub expansion portion expand substantially in a V-shape, the main expansion portion and the sub expansion portion are easily constricted at the base portion, and each can move freely. Become like Thus, the sub-inflations remain as "walls" while the main inflation is inflated, independent of the main inflation.

According to a third aspect of the present invention, there is provided the airbag device for an automobile according to the first or second aspect, wherein the sub-inflation portion has substantially the same cross section along the longitudinal direction and has an exhaust hole. It is characterized by not doing.

According to the third aspect of the present invention, since the sub-inflation portion has substantially the same cross section and does not have an exhaust hole, it is possible to form a "wall" having substantially uniform strength by expanding the whole. it can.

According to a fourth aspect of the present invention, there is provided an airbag device for an automobile according to any one of the first to third aspects,
The main inflation portion is formed by assembling a cylindrical first expansion portion continuous with the gas inlet and a plurality of second expansion portions extending from a predetermined point on the tip side of the first expansion portion on the predetermined point side. It is characterized in that it has a folded shape with a gathered portion.

According to the fourth aspect of the present invention, the first inflatable portion expands, so that the gathering portion of the second inflatable portion jumps out into a wide space outside the airbag module. The whole part can be developed quickly.

According to a fifth aspect of the present invention, there is provided the airbag device for an automobile according to the fourth aspect, wherein the gathering portion of the main inflatable portion is rewound downward along the surface of the instrument panel. The first developing part is wound around the outer periphery of the collecting part.

According to the fifth aspect of the present invention, since the gathering portion is rewound downward along the surface of the instrument panel, the main inflatable portion extends sufficiently downward and is easily deployed toward the occupant. .

According to a sixth aspect of the present invention, there is provided an airbag device for an automobile according to any one of the first to fifth aspects,
An exhaust hole is formed in a portion of the main inflatable portion other than a region for receiving an occupant.

According to the sixth aspect of the present invention, since the exhaust hole is formed in the main inflating portion, the function of lowering the internal pressure of the airbag is further enhanced. Further, since the exhaust hole is formed in a portion other than the region for receiving the occupant, there is no possibility that the exhaust hole is blocked by the occupant.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. Reference numeral 1 denotes an instrument panel of an automobile, and a front window panel 2 is located above the instrument panel. An opening 3 is formed on the upper surface of the instrument panel 1, and an airbag module 4 is installed in the opening 3.

The airbag module 4 mainly comprises a case 5, an airbag 6, an inflator 7, and a cover 8. The case 5 has a metal upper opening type container shape and is firmly fixed to a steering member (not shown). A hook 9 is formed at the upper end of the case 5, and a leg 10 formed on the back surface of the cover 8 is engaged with the hook 9. The end of the cover 8 is connected to the opening 3 of the instrument panel 1.
And the claw portions 11 formed at the ends of the cover 8 are engaged with the edges of the opening 3, respectively, so that the cover 8 rattles. Without a stable state. The case 5 is in a state where the upper portion is closed by the cover 8. The cover 8
It is made by injection molding an olefin-based elastomer (TPO), and has a thin-walled cleavage portion 12 formed on the back surface.

The inflator 7 is stored at the bottom of the case 5. The inflator 7 ejects a high-pressure gas upon receiving a signal from a sensor (not shown) at the time of collision. A mid retainer 13 is bridged at an intermediate position on the inner surface of the case 5. This mid retainer 1
Although not shown in the drawing, a plurality of holes 3 are formed in 3 so that the gas of the inflator 7 can be passed through.

The airbag 6 is housed in the upper part of the mid retainer 13. The airbag 6
The gas inlet 14 is fixed between the mid retainer 13 and the inner surface of the case 5. The airbag 6 is folded and stored in a predetermined manner, and the upper side of the airbag 6 is provided with a pair of covering cloths 1 whose ends are sandwiched together with the gas introduction port 14 of the airbag 6.
5.

The airbag 6 is branched from a gas inlet 14 into a small-capacity sub-inflation portion 16 and a large-capacity main inflation portion 17. The sub-inflation portion 16 is located on the side of the front window panel 2, and is housed above the case 5 in a folded state. The sub-inflation portion 16 has substantially the same cross section along the longitudinal direction. The main expansion portion 17 is folded in a T-shaped bellows shape. As shown in FIG. 2, the T-shaped bellows shape includes a cylindrical first developing portion 18 continuous with the gas introduction port 14 and a plurality of extending portions extending from a predetermined point on the distal end side of the first developing portion 18. This is because the folded shape provided with the gathering portion 20 in which the second developing portion 19 is gathered on the predetermined point side is a T-shape and a bellows shape. Then, the gathering section 20 winds the first developing section 18 around the outer circumference while rotating in the direction A in FIG. Therefore, the direction in which the collecting portion 20 is rewound is the opposite B direction.

FIG. 3 shows the air bag 6 in a three-dimensional manner. A gas inlet 14 is located at a position closer to one side of the lower surface, and the shorter one from the gas inlet 14 is the sub-inflation part 16 and the longer one is the main expansion part 17. Main expansion part 17
Exhaust holes 22, 22 are formed in the upper side of the sub-expansion part, but no opening for exhaust is formed in the sub-inflation part 16. This is a feature of the present invention.

The airbag 6 is formed of two base cloths, an upper cloth 23 and a lower cloth 24 as shown in FIG. Both the upper cloth 23 and the lower cloth 24 have a basic shape of a sector, and one side thereof is slightly extended in order to form the sub-inflation portion 16. The upper cloth 23 is formed with a pair of the exhaust holes 22, and the other is integrally provided with an extension 25 that forms a surface for receiving an occupant. This upper cloth 2
The airbag 6 is formed by sewing the edges of the lower cloth 3 and the lower cloth 24. As described above, since the airbag 6 of this embodiment is formed by the two pieces of the upper cloth 23 and the lower cloth 24, the manufacture is easy.

Next, the actual deployment behavior of the airbag 6 will be described with reference to FIGS. FIG. 5 shows a state in which the occupant M has abnormally approached the instrument panel 1. When a vehicle collides in this state, gas is blown from the inflator 7 to the airbag 6. Since the gas ejected into the airbag 6 has no destination before the cover 8 is opened, the internal pressure of both the main inflation portion 17 and the sub-inflation portion 16 is sufficiently increased in the airbag module 4 and the cover 8 Up to the high pressure required to cleave it. When this state is reached, the cover 8 is
, And the small-volume sub-inflation portion 16 is first developed first (see FIG. 6). At this time, since the sub-inflation portion 16 has a small capacity and no exhaust hole is formed in the sub-inflation portion 16, the sub-inflation portion 16 contacts the front window panel 2 from below to form a “wall”. At the moment when the cover 8 is opened, the sub-inflation portion 16 is deployed, and the internal pressure of the airbag 6 is reduced by the amount of the gas used for the deployment of the sub-inflation portion 16, so that the proper internal pressure adjustment of the airbag 6 is performed. It can be carried out.

When the sub-inflation section 16 expands to form a "wall", the main inflation section 17 is unfolded during that time, and gas starts flowing toward the low-pressure main inflation section 17 side. The main expansion portion 17
When the first developing unit 18 expands, the second developing unit 19
Are protruded out of the airbag module 4 in a state in which they are gathered, so that the whole can be quickly deployed even with a relatively small pressure. Main expansion part 17
The sub-inflation portion 16 does not shrink while the swells. When both the sub-expansion portion 16 and the main expansion portion 17 expand, they become substantially V-shaped in a side view (see FIG. 7).

In this embodiment, since the sub-inflation portion 16 developed on the front window panel 2 side acts as a "wall" with respect to the main expansion portion 17 which develops with a delay,
The direction of the main expansion portion 17 is guided to the occupant M side. That is, the launch angle α of the main inflatable portion 17 is reduced by the action of the sub-inflatable portion 16 as a “wall” (see FIG. 6), and the deploying direction is urged toward the occupant M. Moreover, the main expansion portion 17 and the sub expansion portion 1
6 expands in a substantially V-shape, so that the main inflation portion 17 and the sub-inflation portion 16 are easily constricted at the base portion, and each can freely move. Therefore, the sub-expansion part 16 is
, While the main inflation portion 17 is inflated,
Continue to exist as a "wall". Furthermore, since the sub-expansion part 16 has substantially the same cross section, the entire wall expands, whereby a "wall" having substantially uniform strength can be formed.

Further, when the gathering portion 20 of the airbag 6 is rewound in the direction B, the instrument panel 1
Promotes downward deployment along the surface of the That is, since the collecting part 20 is rewound in the direction of rolling out to the surface of the instrument panel 1, it extends downward and easily enters between the occupant M and the instrument panel 1 (see FIG. 8). When the main expansion portion 17 extends downward and expands, exhaust is performed from the exhaust hole 22.

The exhaust hole 22 in the main expansion section 17 is
Since the exhaust hole 22 is formed in a portion other than the region for receiving the occupant, there is no possibility that the exhaust hole 22 will be closed by the occupant.

Further, since the length of the sub-inflation portion 16 is set so as to be adapted to the distance between the airbag module 4 and the front window panel 2, the length of the sub-inflation portion 16 is more forward than the front window panel 2 and the airbag module 4. The airbag 6 can be designed without being largely influenced by the shape factor.

[0031]

According to the present invention, since the sub-inflation portion has a small capacity and no exhaust hole is formed in the sub-inflation portion, the sub-inflation portion is deployed earlier than the main inflation portion, and the front window panel is expanded. Contact from below. Therefore, the sub-inflation portion abutting on the front window panel acts as a “wall” in the deployment process, guiding the direction of the main inflation portion to be deployed later to the occupant, and improving the occupant protection performance by the airbag.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an airbag device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main inflation portion and a sub-inflation portion of the airbag.

FIG. 3 is a perspective view showing a three-dimensional shape of the airbag.

FIG. 4 is a plan view showing two cloths constituting the airbag.

FIG. 5 is a cross-sectional view showing the airbag device in a non-deployed state.

FIG. 6 is a cross-sectional view showing an initial state of tearing of a cover of the airbag device.

FIG. 7 is a cross-sectional view showing a state where the main inflation portion of the airbag has begun to inflate.

FIG. 8 is a cross-sectional view showing a state where the main inflating portion of the airbag extends downward along the surface of the instrument panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Instrument panel 2 Front window panel 4 Airbag module 5 Case 6 Airbag 7 Inflator 8 Cover 12 Cleavage part 14 Gas inlet 16 Sub expansion part 17 Main expansion part 18 1st expansion part 19 2nd expansion part 20 Aggregation part 22 Exhaust hole 23 Upper cloth 24 Lower cloth A Winding direction B Rewinding direction M Passenger

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masami Tonooka 218 Aoshima-cho, Fuji-shi, Shizuoka Japan Nippon Plast Co., Ltd. (72) Inventor Ryuji Hori 218 Aoshima-cho, Fuji-shi, Shizuoka Nippon Plast Corporation Terms (reference) 3D054 AA03 AA14 BB16 CC04 CC15 FF16 FF20

Claims (6)

[Claims] An airbag module is formed by housing a folded airbag and an inflator for blowing gas into the airbag in a case whose opening is closed by a cleavable cover, An airbag device for an automobile, wherein an airbag module is installed on an instrument panel below a front window panel, and an airbag inflated in a case opens the cover and deploys the interior of the vehicle, wherein the airbag is an inflator. From the gas introduction port to a small-capacity sub-inflation portion and a large-capacity main inflation portion. The sub-inflation portion is located on the front window panel side and abuts on the front window panel when inflated. The airbag device for an automobile, wherein the main inflating portion is located on the occupant side. 2. The vehicle airbag device according to claim 1, wherein the main inflating portion and the sub-inflating portion inflate in a substantially V shape in a side view. Bag device. 3. The airbag device for a vehicle according to claim 1, wherein the sub-inflation portion has substantially the same cross section along the longitudinal direction and has no exhaust hole. Automotive airbag equipment. 4. The airbag device for an automobile according to claim 1, wherein the main inflation portion is a cylindrical first deployment portion that is continuous with a gas introduction port. An airbag device for an automobile, wherein the airbag device has a folded shape including a plurality of second developed portions extending from a predetermined point on the distal end side of the first deployed portion and an aggregated portion assembled on the predetermined point side. 5. The vehicle airbag device according to claim 4, wherein the gathering portion of the main inflatable portion is wrapped downward along the surface of the instrument panel, and has an outer periphery of the gathering portion. An airbag device for an automobile, wherein a first deployment portion is wound around the airbag. 6. The airbag device for an automobile according to claim 1, wherein an exhaust hole is formed in a portion of the main inflatable portion other than a region for receiving an occupant. Car airbag device.