JPH04244453A - Air bag device - Google Patents

Abstract

PURPOSE:To regulate a pressure in a bag to an optimum value according to a collision speed and to simplify the structure. CONSTITUTION:A bag body 1 is divided into a main bag 5 on the steering wheel 2 side and a subbag 6 on the passenger side by means of a partition wall 4, and a check valve 7 to prevent the reverse flow of gas from the subbag 6 to the main bag 5 is located to the partition wall 4. An annular regulating bag 15 communicated to the subbag 6 is provided, and the regulating bag 15 forms the peripheral edge of an exhaust hole 14 of the main bag 5. The regulating bag 15 is expanded according to the magnitude of a load when a passenger is collided with the subbag 6, the diameter of the exhaust hole 14 is changed, and this constitution hardens the bag body 1 according to the magnitude of the load.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device that is placed in front of a seat in a vehicle, and inflates and deploys the bag body in the event of a collision to restrain an occupant and prevent a secondary collision.

0002

2. Description of the Related Art As is well known, an airbag device operates an inflator based on the sensing action of a collision sensor when a vehicle or the like collides, and inflates the bag body with the gas generated from the inflator, thereby rapidly inflating the bag body. When deployed, it restrains the occupant who is moving forward due to inertia in the event of a collision. By the way, in such an airbag device, if the internal pressure of the bag body is constant, the bag body will be too hard when restraining an occupant in a low-speed collision, and the reaction to the occupant will be large, and conversely, in a high-speed collision, When restraining an occupant, a situation occurs in which the compression stroke of the bag body is too large. For this reason, as shown in Japanese Utility Model Application Publication No. 61-204855, for example, there are two types of inflators that inflate and deploy the bag body: a low-speed inflator that operates in the event of a low-speed collision, and a high-speed inflator that operates in the event of a high-speed collision. It is known that the vehicle is equipped with an inflator, and in the event of a low-speed collision or a high-speed collision, dedicated inflators are operated respectively.

0003

[Problems to be Solved by the Invention] When an airbag unit is provided with a low-speed inflator and a high-speed inflator, the airbag unit inevitably becomes larger. Therefore, when installing the airbag unit in the steering wheel, it is difficult to secure the installation space, which causes problems in the layout.

SUMMARY OF THE INVENTION Therefore, the present invention provides an airbag device that does not involve increasing the size of the airbag unit and can set the internal pressure of the bag body to a pressure suitable for restraining an occupant depending on the collision speed. It is something.

[0005]

[Means for Solving the Problem] The bag body is divided into a main bag on the front side and a sub-bag on the side facing the passenger by a partition wall, and the partition wall has a structure in which gas flows from the sub-bag side to the main bag side. An adjustment bag is provided with a check valve to prevent the above-mentioned sub-bag, and communicates with the sub-bag to form the outer edge of the exhaust hole of the main bag, and expands and reduces the diameter of the exhaust hole depending on the degree of interference between the passenger and the sub-bag. is provided.

[0006]

[Operation] When an occupant violently interferes with the sub-bag of the airbag body during a high-speed collision, the pressure inside the sub-bag becomes greater than the pressure inside the main bag, and the check valve in the bulkhead closes, so the pressure inside the sub-bag is adjusted. The bag expands and causes the main bag exhaust hole to contract. Therefore, the gas flowing out from the exhaust hole is restricted, and the bag body becomes hard.

On the other hand, if an occupant interferes with the sub-bag of the airbag body during a low-speed collision, the pressure inside the sub-bag, which is higher than the pressure inside the main bag, closes the check valve on the bulkhead and closes the adjustment bag. It will expand, but the pressure inside the subbag is not very high, so the adjustment bag will not expand much.
The degree of diameter reduction of the exhaust hole of the main bag is reduced, and therefore more gas flows out from the exhaust hole, making the bag body soft.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking an automobile airbag device as an example.

In FIGS. 1 and 2, reference numeral 1 denotes a bag body, which is stored in a cover pad (not shown) of a steering wheel 2 of an automobile, and a well-known inflator 3 is attached to the steering wheel 2 side. There is.

The bag body 1 is divided by a partition wall 4 into a main bag 5 on the steering wheel 2 side, which is the front side, and a sub-bag 6 on the side facing the passenger.

The partition wall 4 has two check valves 7 that allow gas to flow from the main bag 5 to the sub-bag 6 but prevent gas from flowing from the sub-bag 6 to the main bag 5.
There are places set up.

The check valve 7 has a valve seat 9 made of resin or the like installed around a hole 8 formed in the partition wall 4, and a valve body 10 that can come into contact with the valve seat 9. A fixing bag 13 having a ventilation hole 11 is attached around the hole 8 so as to cover it.

The sub-bag 6 includes an annular adjustment bag 1 that forms the outer edge of the exhaust hole 14 of the main bag 5.
5 are connected to each other via an introduction pipe 16.

The adjustment bag 15 adjusts the pressure inside the subbag 6,
That is, the adjustment bag 15 is configured to inflate according to the pressure inside the sub-bag 6 at the time of occupant interference, which varies depending on the collision speed at the time of a frontal collision of the vehicle and whether or not the occupant is wearing a seat belt. The diameter of the exhaust hole 14 of the main bag 5 is gradually reduced to reduce the amount of exhaust gas.

A spherical check valve 17 is provided in the introduction pipe 16 to prevent the gas in the adjustment bag 15 from flowing back into the sub-bag 6.

According to the airbag device of the above embodiment, when the deceleration of the vehicle exceeds a predetermined value at the time of a frontal collision, the inflator 3 is immediately activated by a sensor (not shown), and the gas pressure generated from the inflator 3 is activated. The bag body 1 is
It expands and expands rapidly with destruction of the cover pad (not shown).

At this time, the gas generated from the inflator 3 flows from the main bag 5 through the check valve 7 into the sub bag 6, so that the main bag 5 as shown in FIG.
Internal pressure P1 and sub-bag 6 internal pressure P1 are P1=P1
and equal. At this time, the adjustment bag 15 that communicates with the sub-bag 6 is slightly inflated and the exhaust hole 14 is opened as shown in FIG.
Let be the cross-sectional area A1 (diameter a).

[0018] If the vehicle collision speed is low or the occupant collides with the bag body 1 while the occupant is wearing a seatbelt, the impact force F1 by the occupant will cause the sub-bag to collapse as shown in FIG. 6 internal pressure changes from P1 to P2 (P2>P1), check valve 7 closes, and adjustment bag 15 expands.

As a result, the exhaust hole 1 of the main bag 5
The diameter of 4 decreases from a to b (b<a) (see Figure 7).
, the cross-sectional area of the exhaust hole 14 of the main bag 5 is from A1 to A2.
(A2<A1), the gas in the main bag 5 is appropriately discharged from the exhaust hole 14, and the impact force caused by interference from the occupant is absorbed in a soft state.

On the other hand, when an occupant collides with the bag body 1 when the vehicle collision speed is high or when the occupant is not wearing a seat belt, the impact force F2 (F2
>F1), the internal pressure of the sub-bag 6 changes from P1 to P3 (P3>P2>P1), the check valve 7 closes, and the adjustment bag 15 expands, as shown in FIG.

[0021] As a result, the exhaust hole 1 of the main bag 5
The diameter of main bag 4 is reduced from a to c (c<b<a) (see Fig. 8), and the cross-sectional area of the exhaust hole 14 of main bag 5 is reduced from A1 to A3 (A3<A2<A1). , the discharge of gas in the main bag 5 is suppressed to a low level, and the large impact force F2 exerted by the occupant is counteracted.

Here, the pressure inside the sub-bag 6 drops immediately after the interference of the occupant, but even if the pressure inside the sub-bag 6 drops like this, the check valve 17 provided in the introduction pipe 16 prevents the introduction. Since the tube 16 is closed, the degree of expansion of the adjustment bag 15 remains constant, so the diameter of the discharge hole 14 does not change.

[0023] In this way, the hardness of the bag body 1 is automatically adjusted in accordance with the state of interference with the bag body 1 by the occupant, although the structure is simple.

[0024] Therefore, when the hardness of the bag body 1 is set based on a high-speed collision, there is no problem such as the bag body 1 being too hard in a low-speed collision.

[0025]

Effects of the Invention As explained above, according to the present invention, the more violently the occupant collides with the bag body, the higher the pressure inside the sub-bag becomes, causing the adjustment bag to expand, causing the main bag's exhaust hole to rise. This makes it possible to make the bag body harder.

[0026] Therefore, the internal pressure of the bag body can be automatically adjusted to a pressure suitable for restraining the occupant in accordance with the collision speed.

Furthermore, since the structure is simple, it has the advantage of being compact and can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along line AA in FIG. 2 of an embodiment of the present invention.

FIG. 2 is a perspective view of the same.

[Fig. 3] An explanatory diagram of the development situation.

[Fig. 4] An explanatory diagram of the development situation.

FIG. 5 is an explanatory diagram of the development situation.

FIG. 6 is an explanatory diagram of main parts corresponding to FIG. 3;

FIG. 7 is an explanatory diagram of main parts corresponding to FIG. 4;

FIG. 8 is an explanatory diagram of main parts corresponding to FIG. 5;

[Explanation of symbols]

1...Bag body 4...Bulkhead 5...Main bag 6...Sub bag 7...Check valve 14...Exhaust hole 15...Adjustment bag

Claims (1)

[Claims] Claim 1: The bag body is divided into a main bag on the front side and a sub-bag on the side facing the passenger by a partition wall, and the partition wall has a reverse wall that prevents gas from flowing from the sub-bag side to the main bag side. a stop valve is provided and communicates with the sub-bag to form an outer edge of the main bag exhaust hole;
An airbag device comprising an adjustment bag that expands and reduces the diameter of an exhaust hole depending on the degree of interference between an occupant and a sub-bag.