JPH07215161A - Gas generator for air bag - Google Patents

Abstract

PURPOSE:To prevent scattering of splinters of a thin plate member in an air bag by demarcating an opening part by a separated line engraved on the thin plate member so that it opens at the time when pressure in a housing exceeds specified pressure and providing a part where no separated line is engraved along an exhaust port. CONSTITUTION:An opening part 14 of a thin plate member 13 is demarcated by a separated line 16, and this separated line 16 consists of a V groove engraved on the surface of the thin plate member 13. The opening part 14 has a part 17 where the separated line 16 is not engraved along the periphery of an exhaust port 10. This part 17 exists between one end and the other end of the separated line 16 and makes a region connecting the opening part 14 and the thin plate member 13 to each other. This part 17 makes it possible to bend the opening part 14 at the part where the separated line 16 is not engraved as its being separated from the thin plate member 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for an air bag for protecting an occupant from an impact, and more particularly to a structure of a moistureproof thin plate member for sealing a discharge port of its housing.

[0002]

2. Description of the Related Art As a conventional gas generator, a housing having a gas outlet, gas generating means arranged in the housing, ignition means for igniting the gas generating means, and the outlet. And a moisture-proof thin plate member for sealing.

When the gas generating agent forming the gas generating means in the housing is affected by moisture, there is a possibility that normal combustion of the gas generating agent may be impaired. So, the inner surface of the housing,
Alternatively, a moisture-proof thin plate member is fixed to the outer surface to prevent outside moisture from entering the housing through the gas discharge port.

When the ignition means is actuated upon impact and the gas generating agent is burned to generate a high-pressure gas, the combustion gas destroys the wall of the moisture-proof thin plate member and discharges the exhaust port of the housing. Pass through and eject into the airbag.

[0005]

When the combustion gas destroys the moisture-proof thin plate member and ejects it into the airbag, the fragments of the thin plate member are also scattered into the airbag together with the ejected gas, and these scattered fragments are contained in the airbag. It may hit the inner wall and damage it.

Therefore, it is an object of the present invention to provide a novel gas generator for an air bag which solves the problems of the prior art.

[0007]

A gas generator for an air bag according to the present invention includes a housing having a gas discharge port, a gas generating means disposed in the housing, and an ignition means for igniting the gas generating means. Igniting means, and a moisture-proof thin plate member for sealing the outlet, a gas generator for protecting the occupant from impact by introducing gas generated by the gas generating means into the airbag by impact, The thin plate member includes an openable portion that can be opened by pressure in the region of the discharge port, and the openable portion is engraved on the thin plate member so as to open when the pressure inside the housing exceeds a predetermined pressure. It is characterized in that it has a portion which is defined by the separated line and in which the separation line is not engraved along the discharge port.

The thin plate member in the gas generator of the present invention is
An openable part is provided in the area of the outlet of the housing. The openable portion is openable by pressure, and is defined by a separation line engraved on the thin plate member so as to open when the pressure in the housing exceeds a predetermined pressure. The openable portion also has a portion along the discharge port where the separation line is not engraved.

When the openable portion receives pressure, the separation line is
It acts to separate the openable portion from the thin plate member along the separation line. Also, the part where the separation line is not engraved,
The openable portion is bendable and acts to prevent the openable portion from being released from the thin plate member and released into the airbag.

The openable part is defined by a separating line, so that the openable part can be formed in any shape by this separating line.

The separation line is engraved with a predetermined depth from the surface of the thin plate member, and this depth can be determined in consideration of the material and thickness of the thin plate member, the area of the openable portion, the internal pressure and the like. The separating line can be cut or formed by a groove.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, an example in which the present invention is applied to the gas generator for the passenger seat is shown, but the present invention is not limited to this, and the present invention can also be applied to the gas generator for the driver's seat.

FIG. 1 is a sectional view of the present gas generator. This gas generator has a cylindrical housing 1 with both ends closed.
Have. This housing 1 has a plurality of circular discharge ports 10 through which combustion gas of the gas generating agent is discharged in a region on the occupant side. A combustion tube 9 is arranged in the housing 1. The combustion cylinder 9 has a cylindrical shape, and is provided with openings 11 for discharging gas over the entire circumference and at intervals in the axial direction. The combustion cylinder 9 is arranged coaxially with the housing 1 and extends to both ends of the housing 1.

Inside the combustion tube 9, a transfer tube 5 is disposed coaxially with the combustion tube 9 over the entire length of the combustion tube, and an annular combustion chamber is provided between the transfer tube 5 and the combustion tube 9. 8 is formed. A large number of disk-shaped gas generating agents 15 are arranged in parallel in the combustion chamber 8 so as to be fitted to the outer surface of the flame transfer tube 5, and a filter 12 is provided outside the combustion cylinder 9 so as to surround them.

Inside the transfer tube 5, an igniter 4 which operates by a signal from a sensor (not shown) and a transfer charge 6 which is ignited by the igniter 4 are loaded. The igniter 4 is an adapter 2 attached to one end of the housing.
The transfer charge 6 is stored in the transfer charge container 3 and is contained in the transfer charge container 3, and the transfer charge container 3 and the igniter 4 are in contact with each other.

The transfer tube 5 is provided with a large number of openings 7 through which the flame of the transfer charge 6 is ejected, and these openings 7 are formed in the tube wall of the transfer tube in a uniformly dispersed manner.

A thin plate member 13 is fixed to the inner surface of the housing 1 at least in a region where the discharge port 10 is formed. The thin plate member 13 can be formed of, for example, a thin metal plate, and hermetically closes the discharge port 10 so that moisture outside the discharge port 10 does not enter the housing.

2 to 4 are enlarged views of essential parts of the thin plate member 13 shown in FIG. The thin plate member 13 includes an openable portion 14 that can be opened by pressure in the region of the discharge port 10. As shown in FIG. 3, the openable portion 14 is defined by a separating line 16, and the separating line 16 defines the thin plate member 13.
The V-shaped groove is engraved on the surface of the. V-shaped groove
In this embodiment, a circular shape is drawn, and thus the openable portion 14 is defined as a circular shape. Further, the openable portion 14 is a portion 17 where the separation line 16 is not formed along the peripheral edge of the discharge port 10.
have. The portion 17 exists between one end and the other end of the separation line 16 and forms a region connecting the openable portion 14 and the thin plate member 13. This portion 17 allows the openable portion 14 to be bent around the portion 17 when the openable portion 14 opens due to pressure generation, and prevents the openable portion 14 from being separated from the thin plate member 13. Has the function of holding.

FIGS. 5 and 6 show an embodiment of a thin plate member having a plurality of openable portions. FIG. 5 is provided with two openable portions 14 'such as double doors which are symmetrical to each other with respect to the center separation line 16'. In this case, the openable portion 14 'is
It is designed to open on both left and right sides under pressure. Figure 6
Comprises a fan-shaped openable portion 14 ″ divided into eight by intersecting separation lines 16 ″, and a portion 17 ″ along which the separation line along the periphery of the discharge port 10 is not engraved. Due to pressure generation, this opening is formed. The feasible portion 14 ″ will open outward from the center.

When the sensor detects the impact, the signal is sent to the igniter 4 to operate the igniter 4, whereby the transfer charge 6 is ignited and a high temperature flame is generated. This flame is ejected from the opening 7 of the flame transfer tube 5. The ejected flame ignites the gas generating agent 15 in the opening region. As a result, the gas generant 15 burns to generate high-pressure combustion gas. This combustion gas enters the filter chamber through the opening 11, and the combustion residue is removed while passing through the filter 12. The pressure in the housing acts on the inner surface of the openable part 14 in the region of the outlet 10, and when this pressure exceeds a predetermined pressure, the openable part 14 is separated from the thin plate member 13 along the separation line 16. , Bend around the portion 17 and open the opening 18 (Fig. 4). Although the purified gas is ejected from the exhaust port 10 through the opening 18, the openable portion 14 is held by the portion 17 at that time and the openable portion 14 is not separated from the thin plate member 13. The gas ejected from the exhaust port 10 flows into an airbag (not shown), and the airbag expands rapidly to protect the occupant from impact.

[0021]

Since the gas generator of the present invention is constructed as described above, when the combustion gas is ejected into the airbag through the exhaust port sealed by the moisture-proof thin plate member, it is ejected. It is possible to prevent the fragments of the thin plate member from scattering into the airbag together with the generated gas, so that the scattering fragments are prevented from hitting the inner wall of the airbag and damaging it.

The openable portion can be easily and inexpensively manufactured by engraving a separation line on a conventional thin plate member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of the present gas generator.

FIG. 2 is an enlarged sectional view of a main part of a thin plate member included in the gas generator of FIG.

FIG. 3 is a plan view of the same.

FIG. 4 is a perspective view showing a state in which an openable portion of the thin plate member is opened.

FIG. 5 is a plan view of another embodiment of the thin plate member.

FIG. 6 is a plan view of still another embodiment of the thin plate member.

[Explanation of symbols]

 1 Housing 4 Igniter 5 Fire Tube 6 Transfer Charge 7 Opening 10 Discharge Port 13 Thin Plate Member 14 Openable Portion 15 Gas Generating Agent 16 Separation Line 17 Part Where No Separation Line Is Engraved 18 Opening

Claims (1)

[Claims] 1. A housing having a gas outlet, gas generating means disposed in the housing, ignition means for igniting the gas generating means, and moisture-proof for sealing the outlet. A gas generator that includes a thin plate member and protects an occupant from the shock by introducing gas generated by the gas generating means into the airbag by the shock, wherein the thin plate member can be opened by pressure in the region of the discharge port. An openable portion, the openable portion being defined by a separating line engraved in the thin plate member so as to open when the pressure in the housing exceeds a predetermined pressure, and the openable portion along the discharge port. A gas generator for an air bag, characterized in that it has a portion where the separation line is not engraved.