JPH1071920A - Air bag device for front passenger seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front passenger seat air bag device enabling a main bag to softly touch a front passenger seat occupant irrespective of the disposing position of a base part including a gas producing means in a car room and capable of providing a stable buffering effect for the front passenger seat occupant with the main bag by reducing a difference in backward bulging amounts between the left and right parts of the main bag during expansion and development irrespective of the left and right asymmetrical expansion and development of the main bag. SOLUTION: As the gas blowing-out ports 31 and 32 of an inner bag 3 blows out gas to both left and right sides during the expansion and development of the inner bag 3, a main bag 2 is enabled to softly touch an occupant by reducing the expanding and developing speed of the main bag toward the front passenger seat occupant (backward). The gas blowing-out port 32 of the inner bag 3 for blowing out gas to the large volume right side part 22 of the main bag 2 is formed to be larger in area than the gas blowing-out port 31 of the inner bag 3 for blowing out gas to the small volume left side part 21 of the main bag 2 and both parts 21 and 22 are uniformly expanded and developed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passenger airbag device which is inflated and deployed in the event of a vehicle collision to protect a passenger in a passenger seat.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 5-262195 proposes a double-bag airbag device for a passenger seat which is inflated and deployed at the time of a vehicle collision to protect a passenger in a passenger seat. In this airbag device, a container including an inflator (gas generating means) and fixed in front of a passenger seat of a vehicle, a bag-shaped main bag partially held by the container and folded in the container, A bag-shaped inner bag that has an outlet and is partially held in the container and folded in the main bag, and gas generated from the inflator at the time of vehicle collision flows into the inner bag to inflate and deploy the inner bag. Thereafter, the main bag is blown into the main bag from a gas outlet provided in each part of the inner bag, so that the main bag is inflated and deployed in the front space of the passenger seat.

Further, in this publication, a gas outlet is mainly provided in an upper portion and a lower portion of an inner bag after inflation and deployment, whereby the main bag is temporarily inflated and deployed in a vertical direction in a vehicle compartment, and then the final shape is obtained. It is proposed to expand and deploy. In this type of passenger-seat airbag device, the main bag 2 is inflated and deployed asymmetrically about the left-right center line 4 of the module 1 including the inflator (not shown), as shown by a broken line in FIG. A left-right asymmetric expansion / deployment system is already known.

[0004]

In the above-described passenger airbag apparatus of the double bag type, the main bag is inflated and deployed mainly in the vertical direction at the initial stage of inflation and deployment. There is an advantage that the inflating and deploying speed of the main bag (hereinafter, also simply referred to as “rearward”) is reduced and the main bag can softly contact the occupant in the passenger seat. However, in this method, depending on the arrangement position of the container, the inflation and deployment to the upper or lower side of the main bag is restricted by the inner surface of the windshield or the upper surface of the instrument panel, and the main bag is sufficiently inflated and deployed early in the vertical direction. As a result, there is a possibility that the main bag inflates and deploys to the rear side, that is, the passenger seat side at a high speed.

[0005] The above-described right-left asymmetric inflation-deployment type airbag device for a passenger seat has the advantage that the degree of freedom in arranging the modules can be increased. However, in this method, when gas is blown from the gas outlet of the inner bag toward the main bag mainly rearwardly or vertically as described above with reference to FIG. The gas impinging on the inner surface first strikes the inner surface portion (module facing portion) 20 of the main bag facing the module 1 and then flows toward the right side portion 22 of the main bag 2 having a larger volume than the left portion 21 of the main bag. As a result, the right side portion 22 of the main bag 2 is moved to the left side portion 21 of the main bag 2 as shown by a solid line in FIG.
It has been found that the main bag bulges further rearward and has a distorted shape, which may cause the main bag to swing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and one object of the present invention is to enable a soft contact of a main bag with a passenger in a passenger seat regardless of the position of a case including gas generating means in a vehicle interior. It is an object of the present invention to provide a passenger airbag device. Another object of the present invention is to
Despite the shape of the main bag that expands and deploys asymmetrically, the difference in the amount of rearward bulging between the left side and right side of the main bag during inflation is reduced to reduce An object of the present invention is to provide an airbag device for a passenger seat that can exhibit a stable cushioning effect.

[0007]

In the airbag device for a passenger seat according to the first aspect, the gas outlet of the inner bag blows gas mainly to the left and right sides when the inner bag is inflated and deployed. The inflating and deploying speed of the main bag in the forward direction (rearward direction) is reduced to realize soft contact with the occupant by the passenger's seat main bag. In addition, since the main bag is mainly blown into the main bag in opposite directions from the left and right sides of the inner bag, the inner bag and the main bag can be quickly inflated and deployed in the left and right direction with less obstruction to the inflation and deployment than in the up and down direction. As a result, the two effects of high-speed inflation and deployment of the main bag and soft contact with the passenger on the passenger seat can be achieved at the same time.

[0008] The main bag can be folded into various shapes before inflation and deployment, for example, it can be folded into a zigzag shape, a bellows shape, or a rolled shape. The case is at least gas generating means (so-called inflator)
The shape is free if it is fixed to the vehicle including
It is preferable to include a box-shaped case (a module referred to in the present specification) for storing the gas generating means, the folded inner bag and the main bag. This case can have an opening that is closed by a lid that opens when both bags are inflated and deployed, and gas released from the inflator flows into the inner bag through this opening.

It is a matter of course that one or more gas outlets of the inner bag can be provided on the left and right sides during inflation and deployment. In the passenger airbag device according to the second aspect, both the bags inflate and deploy rearward and upward along the inner surface of the windshield from the upper surface of the instrument panel, so that the main bag can inflate and deploy early in the vertical direction. Despite the difficulty, the main bag can be quickly inflated and deployed to both left and right sides, and as a result, it is possible to achieve both the high speed inflation and deployment of the main bag and the soft contact with the passenger on the front passenger seat. It is possible to improve the degree of freedom of arrangement of the airbag device.

According to the third aspect of the invention, the main bag is inflated and deployed to one side in the lateral direction.
A so-called left-right asymmetric inflation-deployment type airbag device including a portion and a second portion that inflates and deploys to the other side in the lateral direction more than the first portion, and particularly toward the first portion having a small volume after inflation and deployment. Since the amount of gas to be blown out is smaller than the amount of gas blown out to the second portion having a large volume after expansion and deployment, the above-mentioned asymmetrical expansion and deployment method can be used to increase the degree of freedom of the case arrangement position. regardless of,
The difference in the amount of rearward bulging between the left side portion and the right side portion of the main bag at the time of inflation and deployment can be reduced, and the main bag can provide a stable cushioning support effect for the occupant in the front passenger seat.

According to the fourth aspect of the present invention, the ratio of the amount of gas blown out to the first portion of the main bag and the amount of gas blown out to the second portion of the main bag is determined by the final volume x of the first portion. And the final volume y of the second part is substantially proportional to the ratio, so that the main bag can be inflated and deployed to a more appropriate shape. In order to adjust the gas blowing amount of the gas blowing ports on both sides of the inner bag, it is easy to change the ratio of the cross-sectional areas of these gas blowing ports. Here, “almost proportional” means preferably +/− 3.
An error within a range of 0% is allowed. For example,
The ratio of the cross-sectional area a of the gas blowing port for blowing gas toward the first portion side of the main bag to the cross-sectional area b of the gas blowing port for blowing gas toward the second portion side of the main bag is represented by: (0.6 ~ 3.2) a: b = x: y The condition of Expression 1 may be satisfied. According to experiments, when this condition is satisfied, the posture distortion (see FIG. 7) during inflation and deployment of the left-right asymmetric main bag can be suppressed to a favorable range.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the airbag device for a passenger seat of the present invention will be described based on the following examples.
It should be noted that the present invention is not limited to the embodiment, and it is needless to say that various modifications are allowed within the scope of maintaining the gist of the present invention. (Embodiment 1) An airbag device for a passenger seat of this embodiment will be described below.

FIG. 1 is a schematic cross-sectional view of the passenger-seat airbag device after the inflation and deployment is viewed from above.
FIG. 2 is a schematic cross-sectional view after the inflation and deployment is completed, as viewed from the rear.
FIG. 3 shows a cross section taken along the line AA in FIG. In FIG.
1 is a box-shaped module (a case in the present invention) made of a synthetic resin plate fixed to a portion of the instrument panel (not shown) of the vehicle located in front of the passenger seat,
A module (gas generating means in the present invention) 1 stores an inflator (not shown) for generating gas, and an inner main bag 2 is provided around an opening 10 of the module 1.
The outer edge of the opening of the inner bag 3 is held or in contact with the outer bag. Thereby, the gas generated from the inflator flows into the inner bag 3 from the opening 10 of the module 1 to expand and deploy the inner bag 3, and further blows out from the gas outlet 30 of the inner bag 3 into the main bag 2. The main bag 2 is inflated and deployed.

Although not shown, before the inflation and deployment, the main bag 2 and the inner bag 3 are folded and stored in the module 1 as usual, and gas flows from the inflator into the inner bag 3. When released, the two bags 2 and 3 are inflated and deployed, and as shown in FIG. 1 through the opening 10 of the module 1 (in this embodiment, a passenger seat between an instrument panel (not shown) and a passenger seat). To the front space). Therefore, the opening 10 of the module 1 forms a gas inlet of the inner bag 3. The storage state of the two bags 2 and 3 in the module 1 and the gas generating mechanism of the inflator itself are well known and are not the gist of the present invention, so that further description is omitted.

In this embodiment, the opening of the module 1 is opened rearward from the instrument panel (not shown), that is, toward the passenger's seat, and an imaginary line 4 shown by a dashed line in FIG. 10 is a line extending backward from the center in the left-right direction of FIG. In the state where the inflation and deployment of the main bag 2 is completed, a left portion (for example, a first portion in the present invention) 21 of the main bag 2 on the left side of the imaginary line 4 is shown in FIG.
As shown in FIG. 2, the main bag 2 is deployed approximately twice as large in the lateral direction as a right side portion (for example, the second portion in the present invention) 22 of the right side of the imaginary line 4. In addition, when the inflation and deployment of the main bag 2 is completed, the main bag 2 is inflated and deployed rearward and obliquely upward from the module 1 as shown in FIG. (Not shown) and the passenger's seat occupant mainly swells between the head and the head or upper body of the passenger's seat colliding with a windshield (not shown) or an instrument panel (not shown) at the time of a vehicle collision. To prevent The module 1 is fixed to an instrument panel (not shown) so that the center portion of the main bag 2 in the left-right direction is located immediately before the center portion of the passenger seat in the left-right direction. Therefore, the module 1 is eccentrically located to the left with respect to the passenger seat, and other devices or structures can be installed on an instrument panel (not shown) immediately in front of the passenger seat.

On the other hand, in the state where the inner bag 3 is inflated and deployed, the inner bag 3 is inflated and deployed symmetrically as shown in FIG. 2, and as shown in FIG. It is inflated and deployed. Gas outlets 31 and 32 are individually opened on the left and right side surfaces of the inner bag 3, respectively. The opening cross-sectional area of the gas outlet 31 that opens to the left is a, and the gas outlet that opens to the right is The opening cross-sectional area of the mouth 32 is b, the volume of the left portion 21 of the main bag 2 is x,
When the volume of the right portion 22 of the main bag 2 is y,
As described above, each parameter a: b = x: y is set so that (0.6 to 3.2) a: b = x: y...

In this way, the gas outlets 31, 32 of the inner bag 3 blow out gas mainly to the left and right sides, so that the main bag 2 can be rapidly expanded and deployed in the direction (rearward) toward the passenger on the passenger seat. The main bag 2 can be quickly inflated and deployed in the left-right direction with little obstruction to the inflation and deployment, while suppressing soft bag contact with the occupant in the passenger seat by the main bag 2.

Further, the gas flow blown backward from the inner bag 3 collides with the inner surface of the left-right asymmetric main bag 2 and is deflected to the right side portion 22 having a large volume. Shaking can be prevented, and the passenger in the passenger seat can be reliably protected by the main bag 2. The amount of gas blown from the gas outlet 31 of the inner bag 3 to the small volume left portion 21 of the main bag 2 is the amount of gas blown from the gas outlet 32 of the inner bag 3 to the right volume 22 of the main bag 2. Since the amount is smaller, the main bag 2 can be uniformly inflated and deployed in the left and right directions, and the main bag 2 can surely protect the occupant in the passenger seat.

Further, since the left and right gas blowing amounts are set as in the above formula 1, the left and right uniform inflation of the main bag 2 can be further improved. (Embodiment 2) Another embodiment will be described with reference to FIG. In this embodiment, the opening 10 of the module 1 is opened upward from the instrument panel 5 toward the rear, that is, toward the windshield 6, and the main bag 2 extends along the inner surface of the windshield 6 as shown in FIG. It expands and expands upward.

In this embodiment, it is difficult to inflate and expand the inner bag 3 and the main bag 2 toward the instrument panel 5 and the windshield 6 at least at the initial stage of inflation. Since the gas outlets 31 and 32 are formed on the left and right sides as in the case of the first embodiment, the inner bag 3 and the main bag 2 are inflated despite the presence of the instrument panel 5 and the windshield 6. In the initial stage of the deployment, the main bag 2 can be quickly inflated and deployed to the left and right sides, thereby preventing the main bag 2 from being rapidly inflated and deployed to the passenger side of the passenger seat.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view seen from above after the inflation and deployment of a passenger airbag device according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of the passenger airbag device of FIG.

FIG. 3 is a cross-sectional view of the airbag apparatus for a passenger seat taken along line AA in FIG. 2;

FIG. 4 is a schematic longitudinal sectional view of an airbag device for a passenger seat according to a second embodiment during inflation and deployment.

FIG. 5 is a graph 1 of an experimental result in which a coefficient of Expression 1 is determined.

FIG. 6 is a graph 2 of an experimental result in which a coefficient of Expression 1 is determined.

FIG. 7 is a schematic cross-sectional view of a conventional airbag device during inflation and deployment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Module (gas generation means) 2 Main bag 3 Inner bag 21 Left part of main bag 2 (for example, first part) 22 Right part of main bag 2 (for example, second part) 31, 32 Gas outlet

Claims (4)

[Claims] 1. A case fixed to the front of a passenger seat of a vehicle including a gas generating means, a bag-shaped main bag partially held by the case and folded forward of a passenger seat, and a plurality of gas outlets And a bag-shaped inner bag that is folded inside the main bag, wherein gas generated from gas generating means at the time of a vehicle collision flows into the inner bag, and then the main bag is discharged from a gas outlet of the inner bag. In the passenger airbag device, the main bag inflates into the front passenger seat space and flows into the front bag, wherein the gas outlet of the inner bag blows gas mainly to the left and right sides when the inner bag is inflated and deployed. Characteristic airbag device for passenger seat. 2. The airbag device for a passenger seat according to claim 1, wherein the two bags inflate and deploy from an upper surface of an instrument panel of a vehicle to a space between an upper surface of the instrument panel and an inner surface of a windshield. An airbag device for a passenger seat, characterized in that: 3. The airbag device for a passenger seat according to claim 1, wherein the main bag is inflated and deployed to one side in a lateral direction from a lateral center of a gas discharge port of the case,
A second portion that inflates and expands to the other side in the lateral direction from the center in the left-right direction of the gas discharge port of the case, the second portion being expanded toward the first portion side of the main bag. An airbag device for a passenger seat, wherein the first gas outlet blows out a smaller amount of gas than the second gas outlet of the inner bag that opens toward the second portion side of the main bag. 4. The airbag device for a passenger seat according to claim 3, wherein the amount of gas blown from the first gas blowout port is;
The ratio between the amount of gas blown from the second gas outlet and the volume ratio of the first portion and the second portion after expansion and deployment is set to be substantially equal to that of the passenger seat. Airbag device.