JPH0790744B2 - Airbag device for passenger protection - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an occupant protection airbag device used to prevent a secondary collision of an occupant during a vehicle collision, and in particular, an airbag The present invention relates to an airbag device which is housed in a folded state in a retainer case and is inflated and deployed by gas ejected from a gas ejection port of a gas generator.

(Prior Art) An airbag device as one of occupant protection devices that prevents a occupant from making a secondary collision with a steering wheel, an instrument panel, or the like by restricting forward movement of an occupant due to inertial force during a vehicle collision. Is being used. This airbag device introduces high-pressure gas ejected from a gas generator into a airbag during a vehicle collision to rapidly inflate the airbag toward an occupant and restrain the occupant at a sitting position. It is the one.
The airbag has a bag shape with one end opened, and an opening edge portion thereof is fixed to the retainer case. Then, the gas ejection port of the gas generator is arranged so as to face the inner surface of the airbag. The retainer case is attached to a steering wheel, an instrument panel, or the like located in front of an occupant, and an airbag is inflated from an opening at one end of the retainer case toward the passenger compartment.

In such an airbag device, the final shape of the airbag when inflated is set to a shape that the occupant can most effectively receive, such as a flat sphere. Then, normally, the airbag is stored in the retainer case in a compactly folded state.

Conventionally, the airbag has been stored almost uniformly in the retainer case. The gas outlet of the gas generator is arranged at the center of the retainer case.

(Problems to be Solved by the Invention) However, in the case where the gas ejection ports are arranged so as to face the central portion of the airbag thus uniformly stored,
When the airbag device is activated, the airbag is first inflated and deployed from its central portion. Therefore, in the initial stage of inflation, the airbag is pulled by the central portion of the airbag, the peripheral portion thereof extends in the gas ejection direction, and the central portion thereof largely projects. Then, as the pressure inside the airbag rises, the peripheral portion expands laterally, and the central portion retracts,
The airbag will reach the desired final shape. As a result, there is a possibility that the airbag will flap during the expansion and deployment, and the final shape can be sent.

In particular, the tendency becomes strong in the case where the outer peripheral portion of the airbag is made to greatly wrap around the side in order to wrap the occupant. Therefore, it is extremely difficult to surely restrain the occupant's head to abdomen with the airbag.

In order to deal with such a problem, as shown in Japanese Patent Publication No. 56-43890, it has been attempted to regulate the protrusion of the center of the airbag with a hanging strap or the like, For that purpose, it is necessary to arrange a large number of hanging strings inside the airbag, and to fix both ends of the hanging string to the center part of the airbag and the retainer case, respectively, which increases the manufacturing cost of the airbag device. I will end up.

Also, in the case of an airbag device for the passenger seat, the retainer case is opened on the upper surface of the instrument panel, and the airbag bulging from the opening is extended between the rear surface of the instrument panel and the passenger in the passenger seat. Although it is desired that the airbag be extended, it is difficult to regulate the shape of such an air bag that greatly bends even if a hanging string is used.

Even if the present invention has been made in view of such a problem, an object thereof is to enable the airbag to be smoothly inflated and expanded to a predetermined shape without using a hanging cord or the like. That is.

(Means for Solving the Problem) In order to achieve this object, in the present invention, the retainer case is arranged so as to open toward the upper side of the instrument panel, and the gas outlet of the gas generator is It is arranged so as to be biased toward the front side of the vehicle body in the retainer case, and a part of the front side of the folded airbag is arranged above the gas ejection port.

(Operation) With this configuration, when the airbag device is in operation, the small area on the front side of the vehicle body of the airbag housed facing the gas ejection port due to the gas ejected from the gas ejection port First expands and develops and becomes nervous. Then, the gas is guided around the tense portion and circulates to the rear side, and the other portions of the airbag are inflated and deployed in order. At this time, the large area of the airbag stored in the rear side of the retainer case is still in the folded state, and the center of gravity of the airbag is located on the rear side. A bending moment acts.
As a result, the airbag is inflated and expanded while curving.

Therefore, the airbag does not largely project in the gas ejection direction, and even a greatly curved airbag can be inflated and deployed smoothly.

(Examples) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an airbag device for a passenger seat, and FIG. 1 is a longitudinal side view of a front portion of a passenger compartment of an automobile showing an installation state of the airbag device. ~
FIG. 4 is an explanatory view showing an operating state of the airbag device.

As is clear from FIG. 1, the instrument panel 1
Is provided with a recess 2 having a substantially rectangular cross section in the center of the upper surface 1a of the portion facing the passenger seat. The airbag device 3 is installed in the recess 2. Therefore,
Above the airbag device 3, a front windshield glass 4 that is inclined rearward toward the upper side is located.

The airbag device 3 includes a container-shaped retainer case 5 having an open upper end surface. The retainer case 5 has a substantially right triangular cross section in which the front wall 5a is inclined rearward downward. Therefore, its internal volume is
The front side of the vehicle is small and the rear side is large.

A cylindrical gas generator 6 is attached to the central portion of the front wall 5a of the retainer case 5 such that one side of its outer periphery projects into the retainer case 5. This gas generator 6 is designed to eject high-pressure combustion gas by igniting a gas generating agent such as explosive charged inside, and the gas ejection port thereof is a retainer of the gas generator 6. It is provided on the outer peripheral wall exposed in the case 5. In this way, the gas outlets of the gas generator 6 are arranged so as to be biased toward the front side in the retainer case 5. The gas generating agent in the gas generator 6 is ignited when a collision is detected due to deceleration of the automobile or the like.

In the retainer case 5, an airbag 7 is stored in a folded state. The airbag 7 is a bag-shaped one made of a flexible material and having one end opened, and the peripheral edge of the opening is airtightly joined to the peripheral wall of the upper end opening of the retainer case 5. Therefore, the gas ejected from the gas generator 6 into the retainer case 5 is introduced into the airbag 7, and the gas inflates and deploys the airbag 7.

As described above, the internal volume of the retainer case 5 is small on the front side of the vehicle body and is large on the rear side. Moreover, since the gas generator 6 is provided on the front side, the storage volume of the airbag 7 is further reduced. Therefore,
The airbag 7 is accommodated in the retainer case 5 in a small amount on the front side and a large amount on the rear side. That is, the front part of the retainer case 5 is a small storage part, and the rear part is a multi-storage part. And the gas outlet of the gas generator 6 is
It is located on the back side of the small storage part.

As shown in FIG. 4, the final shape of the airbag 7 when inflated is a curved shape in which the front surface extends along the windshield 4 and the lower rear end extends to the rear of the rear surface 1b of the instrument panel 1. Has been done.

The upper end opening of the retainer case 5 is normally closed by a lid 8 that is flush with the upper surface 1a of the instrument panel 1. The lid 8 has a hinge 9 at the front edge.
It is connected to the retainer case 5 via. Further, the rear edge of the lid 8 is locked to the retainer case 5 via a shear pin or the like. In this way, the lid 8 is pushed open from below.

Next, the passenger airbag device 3 configured as described above
The action of will be described.

Normally, as shown in FIG. 1, the airbag 7 is stored in the retainer case 5 in a folded state.
The upper end opening of the retainer case 5 is closed by a lid 8. Therefore, it is kept in the same form as a normal instrument panel.

When the vehicle collides and suddenly decelerates, it is detected by an acceleration sensor or the like, and the gas generator 6 and the gas generating agent are ignited. Therefore, high-pressure combustion gas is ejected from the gas generator 6, and the air bag 7 causes the lid 8 to move due to the pressure of the gas.
Is pressed against the underside of. As a result, the lid 8 is pushed up and pivots upward about the hinge 9 to open the upper end opening of the retainer case 5. Then, the airbag 7 bulges from the upper surface 1a of the instrument panel 1 through the opening.

At this time, since the gas outlets of the gas generator 6 are biased toward the front side of the retainer case 5, the airbag 7
First, the front side portion, which has been housed facing the gas ejection port, expands and deploys. Moreover, since the front portion of the airbag 7 facing the gas ejection port has a small area, the front portion immediately stretches out and becomes tense. As a result, as shown in FIG. 2, the front surface of the airbag 7 has a shape along the windshield 4. At this time, since the large area of the rear portion of the airbag 7, which is housed on the rear side in the retainer case 5, is still held in the folded state, the center of gravity of the airbag 7 is located on the lower surface side of the rear portion. is doing. Therefore, the airbag 7 is subjected to a moment of bending the rear portion downward.

Thus, the upper surface of the airbag 7 has a smooth curved shape. Therefore, the gas ejected from the gas generator 6 circulates to the rear side along the upper surface of the airbag 7, and the third gas
As shown in the figure, the rear lower surface side of the airbag 7 is inflated and deployed. As a result, the airbag 7 smoothly assumes the final inflated shape shown in FIG. 4 without fluttering.

When the airbag 7 is inflated and deployed to the state shown in FIG. 4, the head and chest of the passenger in the passenger seat are supported by the windshield 4 through the upper portion of the airbag 7, and the abdomen is supported through the lower portion of the airbag 7. It is supported by the rear surface 1b of the instrument panel 1. Therefore, the occupant is securely restrained in the sitting position.

Thus, according to the passenger seat airbag device 3,
The airbag can be smoothly inflated and expanded to a predetermined shape without causing any sticking, only by making the accommodation state of the airbag 7 and the mounting position of the gas generator 6 different from the conventional one. Therefore, hanging strings are unnecessary,
The cost can be reduced. In addition, the airbag 7
Quickly reaches the final shape, which improves the occupant's speed.

Further, since the airbag 7 can be inflated and expanded into a greatly curved shape, the airbag 7 can be installed on the rear surface 1b of the instrument panel 1 while the retainer case 5 is installed so as to open on the upper surface 1a of the instrument panel 1. The airbag apparatus 3 for the passenger seat can be extended to the rear side and has a high occupant speed. And
Since the airbag device 3 can be installed on the upper surface side of the instrument panel 1 as described above, the degree of freedom in designing the instrument panel 1 is increased.

Further, by providing a large storage portion that stores a large amount of the airbag 7 and a small storage portion that stores a small amount of the airbag 7 in the retainer case 5, a space is formed on the back side of the small storage portion. Therefore, the gas generator 6 can be arranged in the space. Then, by doing so, the entire airbag device 3 can be housed in the recess 2 having a rectangular cross section, and the space efficiency is improved.

Although the passenger seat airbag device 3 to which the present invention is applied has been described in the above embodiment, the present invention is not limited to this, and can also be applied to a driver seat airbag device and the like.

Further, in the above-described embodiment, the gas generator 6 is directly exposed in the retainer case 5, but an air bag device in which gas is ejected from the gas generator 6 into the retainer case 5 via a gas duct. Also, the present invention can be applied. In that case, the gas ejection port of the gas duct may be arranged so as to be inclined toward one side of the edge fixing portion of the airbag 7.

The shape of the retainer case 5 may be a united triangle as in the above embodiment, or may be a stepped shape with one side being shallow and the other side being deep. Further, the retainer case 5 may be the same as the conventional one, and the folding method of the airbag 7 may be changed so that the airbag 7 can be accommodated in one side less and more in the other side.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the gas ejection port of the gas generator is arranged so as to be biased toward the vehicle body front side in the retainer case, and above the gas ejection port, Since a part of the front side of the folded airbag is positioned, when the airbag is inflated, the airbag is sequentially inflated and deployed from the front side thereof, and the central portion does not significantly project. Therefore, the airbag can be smoothly and promptly inflated to a predetermined shape, and the occupant's high speed can be improved. Further, since a hanging string or the like for restricting the shape change of the airbag when inflated is not required, it is possible to provide an inexpensive airbag device.

Then, by adjusting the amount and the position of the airbag accommodated at the position facing the gas ejection port, it is possible to control the shape change of the airbag during the inflation and deployment process. Therefore, it is possible to smoothly inflate and deploy even an airbag having a greatly curved shape.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a front portion of a passenger compartment of an automobile showing an embodiment of an airbag device according to the present invention, and FIG. 2 shows an initial state of inflation and deployment of the airbag during operation of the airbag device. FIG. 3 is a schematic side view showing a state where the airbag is further inflated and deployed, and FIG. 4 is a schematic side view showing a final inflated shape of the airbag. 1 ... Instrument panel 1a ... Top surface, 1b ... Rear surface 3 ... Air bag device 5 ... Retainer case, 5a ... Front wall 6 ... Gas generator, 7 ... Air bag

Claims (1)

[Claims] 1. A retainer case which is installed on a vehicle body so as to open toward the upper side of an instrument panel, an airbag which is stored in the retainer case in a folded state, and a gas which is stored in the airbag. An air bag device comprising: a gas generator that ejects and inflates and deploys the air bag; and a gas ejection port of the gas generator, which is arranged in a biased manner toward a vehicle body front side in the retainer case, An occupant protection airbag device, wherein a part of a front side of the folded airbag is arranged above the gas ejection port.