JP3107612B2 - Method of fixing pre-filter in gas generator for airbag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a pre-filter in a gas generator for an air bag for protecting an occupant from an impact.

[0002]

2. Description of the Related Art As shown in FIG. 5, a prefilter is disposed around a gas generating agent 15 to filter a combustion gas of the gas generating agent and remove solid matter mixed therein to produce a clean gas. belongs to. The pre-filter 20 is generally made of a fine wire woven in a vertical and horizontal grid pattern, and the axial end face 20a of the pre-filter is formed by a sharp cut surface generated by cutting the wire.

[0003]

In the conventional gas generator, the cut surface of the pre-filter moves up and down, left and right due to vibration or the like, and there is a possibility that the thin canister container may be damaged. As a result, the sealing performance of the canister container is impaired, and the gas generating agent may absorb moisture, which may adversely affect the operation of deploying the airbag in an emergency.

Accordingly, an object of the present invention is to provide a method for fixing a pre-filter in a gas generator for an air bag which solves the above-mentioned problems of the prior art.

[0005]

According to the present invention, there is provided a method for fixing a pre-filter in a gas generator for an air bag, wherein the housing, a gas generator disposed in the housing, and the inside of the housing and the inside of the air bag are communicated. The gas generator includes a canister container having a bottom formed at one end and a second end sealed with a cover, and containing a gas generating agent and a metal pre-filter therein. Has a radial gap between the gas generating agent and the annular space formed by the canister container and the gas generating agent.
A gas generator that is disposed in the vicinity of the pre-filter in a gas generator that introduces gas generated by the gas generator by an impact into an airbag to protect an occupant from the impact.
By caulking the bottom of the canister container , the pre-filter is moved up and down between the bottom of the canister container and the cover member ,
It is characterized by being fixed in the left-right direction .

[0006] The canister container has a bottom formed at one end and a closed end at the other end. The gas generating agent and the pre-filter are accommodated in the sealed interior. The prefilter is disposed in an annular space formed by the canister container and the gas generating agent.

By caulking the bottom portion in the vicinity of the pre-filter, a deformed portion is formed on the bottom portion by caulking. The pre-filter is sandwiched between the deformed portion and the peripheral wall of the canister container, and the bottom portion connected to the deformed portion is formed. The pre-filter is sandwiched between the cover member and the pre-filter, and thus the pre-filter is fixed between the bottom and the cover member.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view of the gas generator.
The housing of the gas generator includes a diffuser shell 1 and a closure shell 3 which forms a space 2 together with the diffuser shell 1. The diffuser shell 1 and the closure shell 3 have circular portions 1a and 3a and peripheral wall portions 1b and 3b formed on the outer periphery of the circular portion, respectively.

A large number of rivets 23 are circumferentially arranged on the circular portions 1a and 3a of the housing.
Numeral 3 connects the diffuser shell 1 and the closure shell 3 to each other near the peripheral wall of the housing.

In the space 2, there is provided a gas generator comprising an igniter, a canister container, and a combustor cup covering the same.

In the space 2, an ignition device housing chamber 4 is defined at the center by a female screw member 16, and a combustion chamber 5 is defined outside by a combustor cup 14, and the combustion chamber 5 is further defined.
, A coolant / filter chamber 19 is formed. The coolant / filter chamber 19 further holds the retainer 11.
Is defined in the upper and lower tiers.

In the igniter accommodating chamber 4, an enhancer (a transfer charge) 6 and a squib (igniter) 10 constituting an igniter are provided.
And are housed. The transfer charge 6 is loaded on a female screw member 16, and the squib 10 is loaded on a male screw member 17 screwed to the female screw member 16. In the combustion chamber 5, a gas generating agent 15 and a pre-filter 20
Is accommodated with its inner periphery fitted to the outer periphery of the female screw member 16 and its outer periphery fitted to the inner periphery of the combustor cup 14. Further, in the coolant / filter chamber 19, the filter 12
However, the coolant 13 is accommodated in the lower stage, respectively.

An opening 7 for transmitting the flame of the transfer charge 6 to the combustion chamber 5 is provided between the ignition device accommodating chamber 4 and the combustion chamber 5, and between the combustion chamber 5 and the coolant / filter chamber 19 is provided. An outlet 14a of a combustor cup for introducing gas generated in the combustion chamber 5 is provided, and between the coolant / filter chamber 19 and an airbag (not shown).
An opening 9 for introducing a coolant and a gas that has passed through a filter is provided.

The canister container 18 is a thin-walled aluminum container, has a cylindrical shape, and has a bottom portion 18 a formed at one end and a cover member 21 sealed at the other end.
Also, a central hole 18b into which the female screw member 16 is fitted at the center.
Having. A ring-shaped gas generating agent 15 is loaded inside the container, and is fixed by a cushion 22. A pre-filter 20 is provided in an annular space 23 formed by the gas generating agent 15 and the canister container 18. The pre-filter 20 is made of a fine wire woven in a vertical and horizontal pattern in a grid pattern. The pre-filter 20 is located on the outer periphery of the gas generating agent 15, filters the combustion gas of the gas generating agent, removes solid matter mixed therein, and cleans the gas. Turn into gas.

The bottom portion 18 near the pre-filter 20
a 'is swaged, and a recess 24 is formed in the swaged area. The recess 24 is formed by a jig 25 with a bearing shown in FIGS. The jig 25 has a cylindrical shape with one end open, has an inner diameter slightly larger than the outer diameter of the canister container 18, and has an axial length 1 shorter than that of the canister container 18. Four bearings 26 are arranged at equal intervals in the circumferential direction on the bottom 25a of the jig.
Are protruding and planted. When using this, fit the bottom 18a of the canister container from the open end of the jig,
Press the bottom of the canister container against the bearing.
This forms four recesses 24 at the bottom. Since the container is made of thin-walled aluminum, it is only necessary to press it, and a recess is easily formed and the container is not damaged.

The pre-filter 20 is sandwiched between the recess 24 and the peripheral wall portion 18c of the canister container and fixed in the radial direction, and is also sandwiched between the bottom portion 18a ″ connected to the recess and the cover member 21 and fixed in the axial direction. In this way, the pre-filter is fixed vertically and horizontally between the bottom and the cover member.

When a sensor (not shown) is actuated by an impact, the squib 10 is ignited, whereby the transfer charge 6 is ignited. The high-temperature, high-pressure flame generated thereby passes through the opening 7, breaks through the wall of the aluminum container 18 filled with the gas generating agent, and ignites the gas generating agent 15 inside. The gas generated in the container 18 is purified by passing through the pre-filter 20, is jetted uniformly through the jet port 14 a, passes through the coolant 13 and the filter 12, and flows into the airbag through the opening 9.

[0019]

According to the present invention, since the pre-filter is fixed, it is possible to avoid a situation in which the thinned canister container is damaged by the cut surface due to the movement of the pre-filter. This ensures that normal operation of the airbag is always ensured.

In addition, the wear of the gas generating agent caused by the movement of the pre-filter is eliminated, and the normal gas generating function of the gas generating agent is ensured.

[Brief description of the drawings]

FIG. 1 is a half sectional view of a gas generator in which the present invention is implemented.

FIG. 2 is a partial cross-sectional view of a canister container in a state where the present invention is implemented.

FIG. 3 is a bottom view of a jig used for carrying out the present invention.

FIG. 4 is a half sectional view of a jig used for carrying out the present invention.

FIG. 5 is a partial sectional view of a conventional canister container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diffuser shell 2 Space 3 Closure shell 9 Opening 15 Gas generating agent 18 Canister container 18a Bottom portion 18a 'Bottom portion related to vicinity of prefilter 20 Prefilter 21 Cover member 23 Annular space 24 Depression 25 Jig with bearing

Claims (1)

(57) [Claims] 1. A gas generator having a housing, a gas generator disposed in the housing, and an opening communicating between the housing and the airbag, wherein the gas generator has a bottom formed at one end. end side includes a canister container containing a gas generating agent and a metal pre-filter therein is sealed by the cover portion, wherein the pre-filter comprises a gas generating agent into the annular space formed between the canister container and the gas generating agent Between
A gas generator disposed with a gap in the radial direction to introduce a gas generated by the gas generator by an impact into an airbag to protect an occupant from the impact, wherein the canister according to the vicinity of the pre-filter by caulking the bottom <br/> portion of the container, the pre-filter canister contents
A method for fixing a pre-filter in a gas generator for an air bag, wherein the pre-filter is fixed between a bottom portion of a container and a cover member in the vertical and horizontal directions .