JPH05178158A - Air bag gas generator with pre-filter covering means - Google Patents

Abstract

PURPOSE:To avoid the acute cutting plane of a pre-filter from abutting on a canister container to prevent the canister container from being damaged by arranging a cover member which covers the pre-filter, which is provided in the canister container. CONSTITUTION:A canister container 18 has the bottom section 18a formed on its end side, and the other end side is covered up tight with a lid member 21, and gas generating agent 15 is loaded in the container 18. In the ring-like space 23 formed by the gas generating agent 15 and the canister container 18, a metallic pre-filter 20 is arranged, and the pre-filter 20 is located in the outer periphery of the gas generating agent 15, filtering combustion gas. Between one end of the pre-filter 20 and the lid member 21 of the canister container 18, a ring-like cover member, that is, a retainer 24 is arranged, and between the other end of the pre-filter 20 and the bottom section 18a of the container 18, another retainer 24 is arranged. The retainers 24 cover the acute cutting plane 20a and external edge of the pre-filter 20, preventing the canister container from being damaged.

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 cover means for a prefilter thereof.

[0002]

2. Description of the Related Art A pre-filter, as shown in FIG. 4, 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 up and down, left and right due to vibrations and the like, which makes it thin (generally 0.1 to 0.2 m).
The canister container of m) may be damaged. 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.

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

[0005]

A gas generator for an air bag having a cover means for a pre-filter according to the present invention includes a housing, a gas generator disposed in the housing,
The gas generator includes a housing and an opening communicating with the airbag, and the gas generator has a bottom formed at one end side and the other end side sealed by a lid member. The container includes a container, the pre-filter is arranged in an annular space formed by a canister container and a gas generating agent, and gas generated in the gas generator by impact is introduced into the airbag to protect an occupant from the impact. The gas generator to protect is characterized in that the gas generator comprises a ring-shaped cover member that covers the axial end surface of the prefilter.

The cover member is formed in a ring shape conforming to the shape of the end surface of the prefilter so as to cover the end surface of the prefilter arranged in the annular space.

As the material of the cover member, for example, iron, resin, aluminum alloy or the like can be used. By pressing these plate materials (with a thickness of 1 mm or less), a predetermined shape can be formed. In this case, the cover member is preferably formed in an L-shaped cross section so that the outer edge of the prefilter can be covered together.

Further, the cover member may be made of an elastic material such as foamed plastic. in this case,
The cover member also functions as a fixing member or a cushion member for the prefilter.

The axial end surface of the pre-filter is covered by the cover member so that the sharp end surface of the pre-filter does not directly contact the canister container.

[0010]

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 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 each have a circular portion 1
a and 3a and a peripheral wall portion 1 formed on the outer peripheral portion of the circular portion
b and 3b.

A large number of rivets 26 are circumferentially arranged on the circular portions 1a and 3a of the housing.
Reference numeral 6 connects the diffuser shell 1 and the closure shell 3 to each other near the peripheral wall of the housing.

In the space 2, a gas generator composed of an ignition device, a canister container, and a combustor cup that covers 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, 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, has a cylindrical shape, has a bottom 18a formed at one end, and is closed at the other end by a lid member 21. Further, the central portion has a central hole 18b into which the female screw member 16 is fitted. Inside the container, a ring-shaped gas generating agent 1
5 is loaded and fixed by the 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. The axial end surface of the pre-filter has a sharp cutting surface 20a formed by cutting the wire.
It is composed of

A cover member, that is, a retainer 24 is disposed between one end surface of the prefilter and the lid member 21 of the canister container. A retainer 24 is also arranged between the other end surface of the prefilter and the bottom portion 18a of the canister container. The cross section of this retainer 24 is L
It has a V-shaped ring shape and is disposed so as to cover the end surface and the outer edge of the prefilter 20. Prefilter 20
The sharp cutting surface 20a of the pre-filter 20 is covered by the retainer 24. Therefore, even if the pre-filter 20 moves up and down, left and right due to vibration, it is avoided that the sharp cutting surface of the pre-filter 20 directly hits the canister container. Does not suffer damage.

Shown in FIG. 3 is another embodiment of the present invention. The cover member is composed of the cushion member 25. The cushion member 25 is made of the same material as the cushion 22 (for example, foamed plastic). The cushion member 25 covers both sharp cutting surfaces 20a of the pre-filter 20, and the elastic force of the cushion member covers the bottom 18a of the canister container and the lid member 2.
It is fixed between 1 and.

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.

[0021]

According to the present invention, since the end face of the prefilter is covered, the sharp cut surface of the prefilter does not directly contact the canister container, and the canister container may be damaged even if the prefilter vibrates. Is gone. According to the present invention, the sealing property of the canister container is ensured, and the normal operation of the airbag is always guaranteed.

[Brief description of drawings]

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

FIG. 2 is a partial sectional view of a canister container including a cover member according to an embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a canister container including a cover member according to another embodiment of the present invention.

FIG. 4 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 Generating Agent 18 Canister Container 18a Bottom 20 Prefilter 21 Lid Member 23 Annular Space 24 Retainer (Cover Member)

Claims (1)

[Claims] 1. A housing having a housing, a gas generator disposed in the housing, and an opening communicating the housing with an air bag, wherein the gas generator has a bottom formed at one end and a bottom formed at the other end. It includes a canister container sealed by a lid member and containing a gas generating agent and a metal pre-filter inside, the pre-filter is disposed in an annular space formed by the canister container and the gas generating agent, and is subjected to an impact. In a gas generator that introduces gas generated by the gas generator into an airbag to protect an occupant from an impact, the gas generator includes a ring-shaped cover member that covers an axial end surface of a prefilter. Characterized by that
A gas generator for an air bag having a prefilter covering means.