JPH04221250A - Air bag device - Google Patents

Abstract

PURPOSE:To sufficiently develop collision energy absorbing effect by properly restraining a driver, even if the timing for restraining the driver by a bag body is delayed. CONSTITUTION:An exhaust port 10 formed on a bag base cloth 6 on the inflator 3 side of a bag body 4 is closed by the turned-back part 11 of the bag base cloth from the outside, and both the side edges at the turned-back part is sewn to the peripheral edge of a bag base cloth 7 on a cover side.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is placed in front of the seat of various vehicles including automobiles, and inflates and deploys the bag body in the event of a vehicle collision, restraining the occupant and causing a secondary collision. The present invention relates to an airbag device that prevents.

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 collides, etc., and inflates the bag body with the gas generated from the inflator. It deploys rapidly to restrain occupants who are 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 reaction force of the bag body increases when the occupant is restrained.
For example, as shown in Japanese Unexamined Patent Publication No. 1-172046, a bag body is known in which an exhaust port is formed in the bag body so that gas generated within the bag body can be exhausted from the exhaust port.

0004

[Problem to be Solved by the Invention] When gas is generated by the operation of the inflator and the bag body is inflated and expanded, part of the generated gas flows out from the exhaust port at the same time as the bag body is expanded. As shown by the line, the internal pressure of the bag body decreases in a relatively short period of time from the peak internal pressure point. Therefore, in cases where the forward inertial movement of the occupant is delayed relative to the timing of inflation and deployment of the bag body, the bag body restrains the occupant in a state where the internal pressure has decreased below the level suitable for restraining the occupant. As a result, the effect of absorbing collision energy for the occupants is slightly reduced.

[0005] Therefore, the present invention is capable of properly restraining an occupant and sufficiently absorbing collision energy even when the forward inertial movement of the occupant is delayed relative to the timing of inflation and deployment of the bag body. The present invention provides an airbag device that can be used to achieve maximum performance.

[0006]

[Means for Solving the Problems] A bag body formed into a bag shape and folded and stored by sewing the peripheral edges of the bag base fabric on the inflator side and the bag base fabric on the cover side in which an exhaust port is formed, and the bag body on the inflator side. In an airbag unit comprising an inflator that seals the periphery of an attachment opening formed in a bag base fabric and fills generated gas into the bag body, an exhaust port is closed from the outside in the bag base fabric on the inflator side. A folded portion is formed, and both side edges of the folded portion are sewn to the periphery of the bag base fabric on the cover side.

[0007]

[Operation] When the generated gas is supplied into the bag body by the operation of the inflator, the bag body is rapidly inflated and deployed. As the bag body expands and expands, the folded portion on the outside of the exhaust port gradually turns over, the exhaust port begins to open, and the generated gas within the bag body begins to flow out. As a result, the internal pressure within the bag body is gradually reduced from the internal pressure peak point.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 indicates an airbag unit disposed in a member in front of the seat, such as the instrument panel or the center of the steering wheel (not shown), and is used for the detection action of the high-sensitivity collision sensor 2. The bag is generally composed of an inflator 3 that operates from the start, a bag body 4 that is folded and stored over the inflator 3, and an airbag cover 5 that houses the inflator 3 and the bag body 4.

The bag body 4 is formed into a bag shape by overlapping and sewing together the bag base fabric 6 on the inflator side and the bag base fabric 7 on the cover side. Attach the periphery of the mounting hole 9 formed in the center to the periphery flange 3a of the inflator 3 with bolts and nuts 1.
2, it is fixed and sealed. A plurality of exhaust ports 10 are formed in the center position of the upper half of the bag base fabric 6 on the inflator side, and a folded part 11 that closes the exhaust ports 10 from the outside is formed in the bag base fabric. This folded part 1
1 are sewn to the periphery of the bag base fabric 7 on the cover side.

[0011] Here, the bag main body 4 is folded to the outermost part so that the part forming the exhaust port 10 can be unfolded at the final stage when the bag main body 4 is unfolded, like a normal bag main body.

According to the apparatus of the above embodiment, when the inflator 3 is activated and generates gas based on the detection action of the collision sensor 2 in the event of a vehicle collision, etc., the bag body 4 is rapidly inflated by the generated gas. expand.

During the rapid inflation and deployment process of the bag body 4, the exhaust port 10 remains blocked by the folded portion 11 at the initial stage of expansion of the bag body 4, so that gas is not released to the outside. There is no outflow, and the internal pressure of the bag body 4 is maintained higher than in the conventional case (see FIG. 3).

When the internal pressure of the bag body 4 increases as the amount of generated gas increases, the folded portion 11 begins to turn over as shown in FIG. However, since the folded portion 11 has both edges sewn to the periphery of the bag base fabric 7 on the cover side as described above, it does not unfold all at once, and the folded bag-like The folded portion expands under internal pressure, the folded inner portion restricts the opening of the exhaust port 10, and as the bag body 4 further unfolds, the folded portion 11 opens as the exhaust port as shown in FIG. The exhaust port 10 is completely opened from the outside of the exhaust port 10 to allow gas to flow out as in the conventional case.

As a result, the internal pressure characteristics when the bag body 4 is inflated and deployed are such that, as shown by line b in FIG. It will be held in In other words, the bag main body 4 can maintain its high internal pressure for a longer period of time than in the conventional case.

Therefore, even if the timing of inflation and deployment of the bag body 4 and the forward inertial movement of the occupant are different, and the timing at which the occupant is restrained by the bag body 4 is slightly delayed, the bag The main body 4 can maintain a high internal pressure state suitable for restraining the occupant, can appropriately restrain the occupant, and can fully exhibit the impact energy absorption effect.

Furthermore, as mentioned above, the expansion of the bag body 4,
During deployment, the presence of the folded part 11 restricts the outflow of gas from the exhaust port 10 to maintain the internal pressure. Therefore, in order to obtain a certain internal pressure necessary for restraining the occupant, the amount of gas generating agent filled in the inflator 3 can be adjusted. It can be reduced compared to the conventional method, and it can also be advantageous in terms of cost.

[0018]

As described above, according to the present invention, the exhaust port formed in the bag base fabric on the inflator side of the bag body is closed from the outside by the folded part of the bag base fabric, and Since both edges of the folded part are sewn to the periphery of the bag base fabric on the cover side, when the bag body is inflated and deployed, the folded parts restrict the outflow of generated gas from the exhaust port at the initial stage of bag body expansion. It is possible to maintain a high internal pressure state in the bag body for a longer period of time compared to conventional ones, and therefore, even if the timing at which the occupant hits the unfolded bag body and is restrained is delayed somewhat, The occupant can be restrained appropriately and the impact energy absorption effect can be fully demonstrated.

Furthermore, since the internal pressure can be maintained by restricting the outflow of gas from the exhaust port by the folded part, the amount of gas generating agent filled in the inflator can be reduced compared to conventional ones when obtaining a certain internal pressure suitable for restraining the occupant. This has the advantage of being cost-effective.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a front view of the bag body of the same embodiment.

FIG. 3 is a sectional view showing a closed state of the exhaust port of the bag body.

FIG. 4 is a cross-sectional view showing a state in which the exhaust port of the bag body begins to be opened.

FIG. 5 is a sectional view showing a state in which the exhaust port of the bag body is fully opened.

FIG. 6 is a diagram showing the internal pressure characteristics of the bag body.

[Explanation of symbols]

1...Airbag unit 3...Inflator 4...Bag body 6... Bag base fabric on the inflator side 7...Bag base fabric on the cover side 10...Exhaust port 11...Folding part

Claims (1)

[Claims] Claim 1: A bag body which is formed into a bag by sewing the peripheral edges of the bag base fabric on the inflator side and the bag base fabric on the cover side in which an exhaust port is formed and is folded and stored, and the bag base fabric on the inflator side. In an airbag unit equipped with an inflator that seals the periphery of the formed attachment port and fills the bag body with generated gas, the bag base fabric on the inflator side is provided with a folded part that closes the exhaust port from the outside. An airbag device characterized in that both edges of the folded portion are sewn to the periphery of the bag base fabric on the cover side.