JPH09175309A - Gas generating device for air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generating device for air bag device of such a structure that a mixture of combustible gas accommodated in a pressure vessel is ignited and combusted, that the gas pressure is boosted by the temp. rise caused by the combustion, and that the combusted gas is introduced to an air bag so as to inflate it, wherein only the combusted gas is sent to the air bag quickly. SOLUTION: Inside of a pressure vessel 5 a gas introducing pipe 9 is furnished leading from the end 5b opposite an ignitor 6 toward the end 5a on the side with ignitor 6, and a blocking plate 11 is provided at the termination of the pipe 9 on the ignitor side, while the other termination on opposite side is put in communication with a gas jet 10 furnished at the end 5b of pressure vessel 5. When a mixture 8 of combustible gas in the pressure vessel 5 is ignited by the ignitor 6, the gas pressure is boosted by the gas combusted, and attainment of the prescribed value will rupture the blocking plate 11 to allow the combusted gas to be sent to the air bag through the pipe 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device mounted on a vehicle or the like for protecting an occupant by injecting compressed gas into an air bag interposed between an occupant and a vehicle interior member to inflate the air bag in the event of a collision. The present invention relates to a gas generator for use.

[0002]

2. Description of the Related Art Conventionally, a gas generating device for an airbag device has used an inert gas such as a compressed nitrogen gas or an argon gas as a gas to be used. However, a device using a combustible gas mixture has been used. It is disclosed in Japanese Unexamined Patent Publication No. 5-278554. This is because the combustible gas mixture contained in the pressure vessel is ignited from one end face side and burned, and when the gas pressure increases due to the temperature rise due to combustion,
The pressure destroys the other end surface of the pressure container so that the combustion gas flows into the airbag to inflate the airbag, and an airbag device with a fast initial response speed can be realized.

[0003]

However, in the device disclosed in the above publication, in the initial state of igniting the combustible gas mixture in the pressure vessel, among the gases in the pressure vessel, the gas on the igniter side is included. However, the gas on the opposite end face side tends to be difficult to burn, and there is a problem that it is difficult to effectively use the combustible gas mixture.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a gas generator for an air bag device which can efficiently and quickly send combustion gas to the air bag.

[0005]

In order to achieve the above object, the present invention introduces a gas introduced into the interior of a pressure vessel from an end face opposite to the igniter toward an end face on the igniter side. A pipe is provided, and a closing sealing plate for closing the inside is provided at an end or an intermediate portion of the gas introduction pipe on the igniter side,
The opposite end is communicated with the gas outlet provided on the end surface of the pressure vessel, and when the combustible gas mixture in the pressure vessel is ignited by the igniter, the gas pressure is increased by the burned gas, When the specified value is reached, the blocking plate provided in the gas introduction pipe is destroyed and the combustion gas is sent to the airbag through the introduction pipe, so that the combustion gas can be quickly sent to the airbag, and the response speed It is possible to realize a fast and highly reliable gas generator for an airbag device.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, a combustible gas mixture is ignited and burned, and a gas body whose gas pressure is increased by temperature rise due to combustion is introduced into an airbag. In a gas generator for an airbag device for inflating, a pressure vessel containing the combustible gas mixture, an igniter provided on a first end surface of the pressure vessel with an ignition portion facing inward, A closing seal that extends from the second end surface facing the first end surface of the pressure container toward the first end surface, communicates with the gas ejection port provided on the second end surface, and closes the inside. A gas introduction pipe provided with a plate and a gas diffusion container having a plurality of gas supply holes for accommodating the pressure container and supplying gas to the airbag, and a combustion gas in the airbag. Can be sent quickly Can.

In the invention according to claim 2 of the present invention, the combustible gas body is a gas mixture of an inert gas, a fuel gas and an oxidant gas, or a lean mixture of the fuel gas and the oxidant gas. It is a gas mixture, and a flammable gas mixture that is easy to handle and easily available can be used.

According to a third aspect of the present invention, the closing sealing plate is provided at the end portion of the gas introducing pipe on the first end face side, and the closing sealing plate can be easily attached. You can

According to a fourth aspect of the present invention, the closing sealing plate is provided in the middle portion of the gas introducing pipe, and the influence of the igniter can be reduced.

According to a fifth aspect of the present invention, the closing sealing plate provided on the gas introducing pipe is broken when the volume ratio of the combustion gas in the pressure vessel reaches at least one half. The breakdown voltage is set so that
The burned gas can be immediately sent to the airbag.

According to the sixth aspect of the present invention, the first end surface of the pressure vessel is a flat surface, and the pressure vessel can be easily processed.

In the invention according to claim 7 of the present invention, the first end surface of the pressure vessel includes a surface which is convexly curved inward,
The combustible gas mixture can be efficiently burned for a short time.

According to an eighth aspect of the present invention, a plurality of gas cylinder flows are provided outside the second end surface of the pressure vessel so as to surround the gas ejection port and guide the gas cylinder flow in a direction different from the ejection direction from the gas ejection port. The gas diffusing member having the gas diffusing hole is provided, and it is possible to prevent the combustion gas ejected from the gas ejection port from directly hitting the end surface of the gas diffusion container.

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a gas generator for an airbag device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes the entire gas generator. Reference numeral 2 denotes a bottomed rectangular tube-shaped gas diffusion container forming the outer contour of the gas generator 1, and an air bag 3 is attached to one side surface thereof and a plurality of gas supply holes 4 are formed therein. The airbag 3 is normally folded. Reference numeral 5 is a pressure container having a closed cylindrical shape, and one end portion (first end surface) 5a of the gas diffusion container 2 is protruded,
It is provided so as to seal the gas diffusion container 2. Reference numeral 6 denotes an igniter provided at one end 5a of the pressure vessel 5 with an ignition portion facing inward, and an electric spark is emitted by a signal from an impact sensor or deceleration sensor (not shown). Reference numeral 7 is a gas inlet provided at one end 5a of the pressure vessel 5 for filling the combustible gas mixture 8 in the pressure vessel 5, and is sealed as shown in the figure after gas injection. Reference numeral 9 denotes a gas ejection port 1 provided at the other end (second end surface) 5b of the pressure vessel 5.
0 is a gas introduction pipe that extends from the other end 5b toward the one end 5a to near the one end 5a, and is a closing seal for closing the inside at the opening end on the one end 5a side. Board 11
It has. The pressure resistance of the closing sealing plate 11 is set so as to break when the volume ratio of the combustion gas in the pressure vessel 5 reaches at least one half.

As the combustible gas mixture 8, a mixture containing an inert gas, a fuel gas and an oxidant gas is used. The inert gas is preferably nitrogen or argon, or a mixture of nitrogen and argon. The fuel gas is preferably hydrogen or methane or a mixture of hydrogen and methane. The oxidizing gas is preferably oxygen. As the combustible gas mixture 8, it is possible to use a lean mixed gas which does not contain an inert gas, has a very thin fuel gas, and has an oxidizing gas amount sufficiently larger than the amount required to burn the fuel gas. .

Next, the operation of the above embodiment will be described. A combustible gas mixture 8 is enclosed in the pressure vessel 5 through a gas inlet 7 under pressure. When the vehicle rapidly decelerates due to a collision, the signal from the impact sensor or the deceleration sensor operates the igniter 6 to ignite the combustible gas mixture 8 in the pressure vessel 5. As a result, first, the combustible gas mixture 8 near the igniter 6 burns, and as shown in FIG. 2, the combustion gas 8a propagates in the pressure vessel 5 to increase the volume of the unburned gas 8b. . When the temperature rises due to the combustion of the combustible gas mixture 8, the gas pressure in the pressure vessel 5 increases, and when it reaches a predetermined value, the closing sealing plate 11 of the gas introduction pipe 9 is broken and pressurized. The combustion gas 8a is
The gas is introduced from the gas introduction pipe 9 through the gas ejection port 10 and the gas supply hole 4 into the airbag 3 to inflate the airbag 3. FIG. 3 shows this state. The combustion gas 8a in the pressure vessel 5 once occupies a small volume in the pressure vessel 5 due to the outflow from the gas introduction pipe 9, but since the unburned gas 8b continues to burn, all of the unburned gas 8b Until the combustion, the combustion gas 8a is supplied through the gas introduction pipe 9 to completely inflate the airbag 3.

FIG. 4 shows the pressure vessel 5 in the above embodiment.
The amount Vb of the combustible gas mixture 8 burnt in the interior of the pressure vessel 5 and the ratio Vt of the combustion gas 8a to the total volume in the pressure vessel 5.
And the gas pressure Pt in the pressure vessel 5 are shown. As is clear from this figure, when the combustible gas mixture 8 in the pressure vessel 5 burns about 15%, the combustion gas 8
Since the volume occupied by a is about 50%, the pressure resistance of the closing sealing plate 11 may be set so that the closing sealing plate 11 of the gas introduction pipe 9 is destroyed by the gas pressure at that time. Of course, the conditions vary variously depending on the type of the combustible gas mixture 8 used, the characteristics of the igniter 6, the size and shape of the pressure vessel 5 and the gas introduction pipe 9, and so on, so that the optimum pressure resistance setting conforming to each condition is set. Is desirable.

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 5 shows the configuration of a gas generator for an airbag device according to the second embodiment of the present invention. The present embodiment differs from the first embodiment shown in FIG. 1 in that the shape of the pressure vessel 5 and the pressure vessel 5
Since the gas diffusion member is provided in the above and other configurations are the same, the same reference numerals are given to the same portions, and only different portions will be described.

In FIG. 5, a closed cylindrical pressure vessel 50 in the gas generator 100 according to the present embodiment.
Has one end 50a provided with the igniter 6 formed into a spherical surface which is convexly curved inward, and the other end 50b is surrounded by a plurality of gas diffusion holes in the radial direction so as to surround the gas ejection port 10. Cap-shaped gas diffusion member 13 having 12
Is attached.

Gas generator 10 having such a structure
At 0, the combustible gas mixture 8 sealed in the pressure vessel 50 is ignited by the igniter 6 by a signal from the impact sensor or the deceleration sensor at the time of collision and burns. At that time, since one end portion 50a of the pressure vessel 50 is curved inwardly convexly, the ignition portion of the igniter 6 is arranged to be convex to the pressure vessel 5 as compared with FIG.
The inside of 0 is placed inside, and the amount of gas burned at the time of ignition increases accordingly, and the combustion gas becomes the pressure vessel 50.
Since the time at which the volume ratio occupies 50% becomes faster, the initial response speed becomes faster. FIG. 6 shows the relationship between the time and the amount of combustion due to the difference in the shape of the end surface of the pressure vessel on the igniter side, where A is a curved surface that is convex inward as in the present embodiment, and B is the embodiment. In the case of the plane as in the case of Mode 1, C shows the case of a curved surface convex to the outside, and the case of A shows that the combustion efficiency is the best.

The flammable gas mixture 8 burns to burn the pressure vessel 5.
When the gas pressure in 0 reaches a predetermined value, the closing sealing plate 11 is broken, and the combustion gas is ejected from the gas ejection port 10 through the gas introduction pipe 9. At this time, in the case of FIG. 1, the jetted gas hits the end face of the gas diffusion container 2 and can change its direction. However, in the present embodiment, the jetted gas hits the end face of the gas diffusion member 13 and changes its direction, and the gas is diffused from the gas diffusion holes 12 on the peripheral surface. It is diffused in the diffusion container 2 and is supplied to the airbag 3 from the gas supply hole 4. Therefore, since the heated combustion gas is not directly injected to the end surface of the gas diffusion container 2, it is possible to prevent a partial temperature rise or deformation of the end surface of the gas diffusion container 2. Such a gas diffusion member 13 can also be used for the pressure vessel 5 in the first and third embodiments.

(Embodiment 3) FIG. 6 shows a third embodiment of the present invention. What is different from FIG. 1 is that the closing sealing plate 11 is not an end portion of the gas introducing pipe 9 but an intermediate portion. It is provided in the section. Any location in the middle can be used. In this way, by providing the closing sealing plate 11 in the middle portion of the gas introduction pipe 9, the influence of electric sparks from the igniter 6 on the closing sealing plate can be reduced, so that the closing sealing plate 1
The breakdown voltage when 1 breaks can be set more accurately. Further, since the combustible gas mixture 8 in the gas introduction pipe 9 is burned, the combustion efficiency is improved.

[0023]

As is apparent from the above-described embodiment, the present invention is provided with a gas introducing pipe extending inside the pressure vessel from the end face opposite to the igniter toward the igniter side. A closing sealing plate that closes the inside is provided at the igniter side end or intermediate part of the gas introduction pipe, and the opposite end is made to communicate with the gas ejection port provided on the end face of the pressure vessel. When the flammable gas mixture in the pressure vessel is ignited by the igniter, the gas pressure increases due to the burned gas,
When the specified value is reached, the blocking plate provided in the gas introduction pipe is destroyed and the combustion gas is sent to the airbag through the introduction pipe, so that the combustion gas can be quickly sent to the airbag, and the response speed It is possible to realize a fast and highly reliable gas generator for an airbag device.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a gas generator for an airbag device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a state during ignition in the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state when the closing sealing plate is broken in the first embodiment of the present invention.

FIG. 4 is an amount Vb of the combustible gas mixture burned in the pressure vessel according to the first embodiment of the present invention, a ratio Vt of the combustion gas to the total volume in the pressure vessel, and a gas in the pressure vessel. Characteristic diagram showing the relationship with pressure Pt

FIG. 5 is a sectional view showing a configuration of a gas generator for an airbag device according to a second embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a relationship between time and combustion amount due to a difference in end face shape of the pressure vessel according to the second embodiment of the present invention.

FIG. 7 is a sectional view showing the configuration of a gas generator for an airbag device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 gas generator 2 gas diffusion container 3 air bag 4 gas supply hole 5 pressure container 5a one end (first end face) 5b the other end (second end face) 6 igniter 7 gas inlet 8 combustible gas mixture 8a Combustion gas 8b Unburned gas 9 Gas introduction pipe 10 Gas ejection port 11 Closure plate 12 Gas diffusion hole 13 Gas diffusion member 50 Pressure vessel 100 Gas generator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Eto, 1-1 1-1 Shimomachiya, Chigasaki-shi, Kanagawa Miyata Industry Co., Ltd. (72) Hiroyuki Takahashi 1-chome, Shimomachiya, Chigasaki, Kanagawa No. 1 in Miyata Industry Co., Ltd.

Claims (8)

[Claims] 1. A flammable gas mixture is ignited and burned,
In a gas generator for an air bag device, which introduces a gas body whose gas pressure is increased by temperature rise due to combustion into an air bag to inflate the same, a pressure container containing the combustible gas mixture, and a first container of the pressure container. An igniter provided with an igniting portion facing inward on one end surface of the pressure vessel, and a second end surface of the pressure vessel facing the first end surface of the igniter, extending from the second end surface toward the first end surface, A plurality of gas supply holes for accommodating the gas inlet pipe, which is connected to the gas ejection port provided on the end face and has a closing sealing plate for closing the inside, and the pressure container, and which supplies gas to the airbag. And a gas diffusion container having a gas generator for an airbag device. 2. The combustible gas body is a gas mixture of an inert gas, a fuel gas and an oxidant gas, or a lean gas mixture of a fuel gas and an oxidant gas. Gas generator for airbag devices. 3. The gas generator for an airbag device according to claim 1, wherein the closing sealing plate is provided at an end portion of the gas introducing pipe on the first end face side. 4. The gas generator for an airbag device according to claim 1, wherein the closing sealing plate is provided at an intermediate portion of the gas introducing pipe. 5. The closed plate provided on the gas introduction pipe has a volume ratio of combustion gas in the pressure vessel of at least 2.
The gas generator for an airbag device according to claim 1, wherein the pressure resistance thereof is set so as to be destroyed when it reaches one-half. 6. The gas generator for an airbag device according to claim 1, wherein the first end surface of the pressure container is a flat surface. 7. The gas generator for an airbag device according to claim 1, wherein the first end surface of the pressure vessel includes a surface that is convexly curved inward. 8. A gas diffusion member having a plurality of gas diffusion holes surrounding the gas ejection port and guiding a gas flow in a direction different from the ejection direction from the gas ejection port, outside the second end surface of the pressure vessel. The gas generator for an airbag device according to claim 1, which is provided with the gas generator.