JPH05123517A - Method for fixing prefilter in gas generator for air bag - Google Patents

Abstract

PURPOSE:To always ensure the normal operation of an air bag by ensuring the sealability of a canister container by caulking the bottom part of the container in the vicinity of the prefilter to fix the prefilter between the bottom part and a cover member. CONSTITUTION:A housing, the gas generator arranged in the housing and the opening communicating with an air bag are provided. A canister container 18 having a bottom part 18a formed to one end thereof and hermetically closed at the other end thereof by a cover member and receiving a gas generating agent, and a prefilter 20 is provided to the gas generator. The prefilter 20 is arranged in the annular space 23 formed by the canister container 18 and the gas generating agent 15, and the gas generated from the gas generator by a shock is introduced into the air bag to protect a passenger from the shock. In this gas generator, the bottom part 18' related to the vicinity of the prefilter 20 of the container 18 is caulked to fix the prefilter 20 between the bottom part 18a and the cover member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of fixing a prefilter in a gas generator for an air bag, which protects an occupant from an impact.

[0002]

2. Description of the Related Art A pre-filter, as shown in FIG. 5, is arranged around a gas generating agent 15 for filtering combustion gas of the gas generating agent to remove solid matters mixed with the combustion gas to obtain a clean gas. belongs to. The pre-filter 20 is generally made of fine wire woven in a vertical and horizontal grid pattern, and the axial end surface 20a of the pre-filter is formed by a sharp cut surface formed by cutting the wire.

[0003]

In the conventional gas generator, the cut surface of the pre-filter moves vertically and horizontally due to vibration and the like, which may damage the thin canister container. As a result, the sealability of the canister container is impaired, the gas generating agent absorbs moisture, and there is a risk that the deployment operation of the airbag in an emergency will be adversely affected.

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

[0005]

A method of fixing a pre-filter in a gas generator for an air bag according to the present invention includes a housing, a gas generator arranged in the housing, and a communication between the housing and the air bag. The gas generator includes a canister container having a bottom portion formed at one end side and the other end side sealed by a cover member to accommodate a gas generating agent and a metal pre-filter therein. Is disposed in an annular space formed by a canister container and a gas generating agent, in a gas generator that introduces the gas generated in the gas generator by impact into the airbag to protect the occupant from the impact, The pre-filter is fixed between the bottom and the cover member by caulking the bottom in the vicinity of the pre-filter.

The bottom of the canister container is formed at one end and the other end is sealed by a cover member. A gas generating agent and a pre-filter are housed inside the sealed interior. The prefilter is arranged 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 due to caulking is formed in the bottom portion, the pre-filter is sandwiched between the deformed portion and the peripheral wall portion of the canister container, and the bottom portion connected to the deformed portion is formed. The prefilter is sandwiched between the cover member and the cover member, and thus the prefilter is fixed between the bottom portion and the cover member.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view of the present gas generator.
The housing in the present gas generator includes a diffuser shell 1 and a closure shell 3 that 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, respectively, and peripheral wall portions 1b and 3b formed on the outer peripheral portion of the circular portions.

A large number of rivets 23 are arranged in the circumferential direction on the circular portions 1a and 3a of the housing.
A diffuser shell 1 and a closure shell 3 are joined to each other in the vicinity of the peripheral wall portion of the housing.

In the space 2, a gas generator including an ignition device, a canister container, and a combustor cup covering the canister container is arranged.

In the space 2, the ignition device housing chamber 4 is defined in the center by the female screw member 16, and the combustion chamber 5 is defined by the combustor cup 14 on the outside thereof.
A coolant / filter chamber 19 is formed surrounding the. The coolant / filter chamber 19 is further provided with a retainer 11
Are demarcated in the upper and lower rows.

In the ignition device accommodating chamber 4, there are an enhancer (transfer charge) 6 and a squib (igniter) 10 which constitute the ignition device.
And are housed. The transfer charge 6 is loaded in the female screw member 16, and the squib 10 is loaded in the male screw member 17 screwed onto the female screw member 16. Further, in the combustion chamber 5, the gas generating agent 15 and the pre-filter 20 arranged around the gas generating agent 15 are provided.
An annular canister container 18 accommodating is accommodated by fitting its inner periphery to the outer periphery of the female screw member 16 and its outer periphery to the inner periphery of the combustor cup 14. Further, in the coolant / filter chamber 19, the filter 12 is provided on the upper stage.
However, the coolant 13 is contained in each of the lower stages.

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

The canister container 18 is a thin aluminum container having a cylindrical shape, a bottom 18a is formed at one end, and the other end is sealed by a cover member 21.
Further, the central hole 18b into which the female screw member 16 is fitted in the central portion
Have. A ring-shaped gas generating agent 15 is loaded inside the container and is fixed by a cushion 22. A prefilter 20 is arranged in an annular space 23 formed by the gas generating agent 15 and the canister container 18. The pre-filter 20 is made of fine wire woven in a matrix shape in the vertical and horizontal directions, exists on the outer periphery of the gas generating agent 15, filters the combustion gas of the gas generating agent, and removes solid matter mixed therein to clean the gas. Turn it into gas.

A bottom portion 18 near the pre-filter 20
A'is crimped, and a recess 24 is formed in this crimped area. The recess 24 is formed by the bearing-equipped jig 25 shown in FIGS. 3 and 4. 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 its axial length 1 is shorter than that of the canister container 18. Four bearings 26 are arranged at equal intervals in the circumferential direction on the bottom portion 25a of the jig.
Is projected and planted. When using this, insert the bottom portion 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 in the bottom. Since the container is made of thin-walled aluminum, it only needs to be pressed, and the 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 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 activated by the impact, the squib 10 is ignited, and the transfer charge 6 is ignited. The high-temperature, high-pressure flame generated thereby passes through the opening 7, penetrates 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 passes through the pre-filter 20 for purification, is uniformly ejected through the ejection port 14a, passes through the coolant 13 and the filter 12, and flows into the airbag through the opening 9.

[0019]

Since the fixing of the prefilter is achieved by the present invention, it is possible to prevent the thin canister container from being damaged due to the movement of the prefilter due to the movement of the prefilter. As a result, the normal operation of the airbag is always guaranteed.

Further, the abrasion 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 guaranteed.

[Brief description of drawings]

FIG. 1 is a half cross-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 which the present invention is implemented.

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

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

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

[Explanation of symbols]

 1 Diffuser Shell 2 Space 3 Closure Shell 9 Opening 15 Gas Generant 18 Canister Container 18a Bottom 18a 'Bottom Related to Prefilter 20 Prefilter 21 Cover Member 23 Annular Space 24 Recess 25 Jig with Bearing

Claims (1)

[Claims] 1. A housing having a housing, a gas generator arranged in the housing, and an opening communicating the inside of the housing with the inside of the airbag. The gas generator has a bottom formed at one end. An end side is closed by a cover member and includes a canister container that accommodates a gas preform and a metal prefilter therein, and the prefilter is disposed in an annular space formed by the canister container and the gas generant. In a gas generator that protects an occupant from a shock by introducing a gas generated by the gas generator into the airbag by a shock,
A method of fixing a prefilter in a gas generator for an air bag, characterized in that the prefilter is fixed between the bottom portion and a cover member by caulking the bottom portion in the vicinity of the prefilter.