JPH05178161A - Igniter fixing means in gas generator for air bag - Google Patents

Abstract

PURPOSE:To facilitate the mounting of an igniter by providing a male screw threadedly fitted to the female screw of a housing to the first holder of a fixing means and providing a recessed engaging section to the end section opposing to a second holder and engaging it with the protruded engaging section of the second holder. CONSTITUTION:The diffuser shell 1 in a gas generator is provided with a female screw at a center cylindrical body 1a to threadedly fit a fixing means, that is, a squib holder 18 to hold an igniter (squib) and fix it to a housing. The first holder 18a of the holder 18 has a male screw 20 which is threadedly fitted in the female screw 17 of the center cylindrical body 1a. The external face 10a of the squib is engaged with the engaging face of the first holder 25, and the external face 10a of the is engaged with the second holder 26 to deform the second holder 18b to engage the protruded engaging section 28 of the deformed holder 18 with the recessed engaging section 27 of the holder 18a. In the next step, the first holder 18a is made to rotate to fasten the screw.

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 fixing means for the igniter.

[0002]

2. Description of the Related Art Conventionally, caulking, an adhesive and the like have been generally used as a method for attaching an igniter to a gas generator.

[0003]

However, fixing by caulking causes a load on the igniter, which poses a problem in work safety. Further, fixing with an adhesive requires a series of operations such as application, attachment and drying, and there is a problem that attachment takes time (usually 24 hours).

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

[0005]

Means for fixing an igniter in a gas generator for an air bag of the present invention includes a housing,
A gas generator disposed in the housing, a fixing means for fixing the igniter constituting the ignition device of the gas generator to the housing, and an opening for communicating the housing with the airbag, In a gas generator that protects an occupant from impact by introducing gas generated by the gas generator into the airbag by impact, the fixing means engages with an outer surface of the igniter to grip the igniter. The first and second holders each have a surface on the inner peripheral surface and are detachable from each other. The first holder has a male thread on the outer peripheral portion to be screwed into a female thread engraved in the housing. It is characterized in that it has a concave engaging portion at an end facing the second holder, and the second holder has a convex engaging portion that engages with the concave engaging portion.

The first holder and the second holder hold the igniter by gripping the igniter by their engaging surfaces. The first holder is fixed to the housing by screw means. Further, the first holder and the second holder are detachable, and the second holder is fixed to the first holder by the engaging means.

The second holder can be made of resin, for example.

[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 a gas generator having fixing means for an igniter according to the present invention. The housing in this gas generator comprises a diffuser shell 1 and a closure shell 3. The diffuser shell 1 and the closure shell 3 respectively have circular portions 1c and 3c and peripheral wall portions 1d and 3d formed on the outer peripheral portion of the circular portions. The diffuser shell 1 includes a central tubular body 1a integrally formed with the circular portion at the central portion of the circular portion 1c. The central tubular body 1a has its tip extending to the outer surface position of the closure shell 3.

A female screw 17 is engraved on the inner peripheral portion of the central cylindrical body 1a. A fixing means for holding the igniter (squib 10) and fixing it to the housing, that is, a squib holder 18, is screwed onto the female screw 17. This squib holder is shown in FIG.
8a and a second holder 18b. These holders 1
Each of 8a and 18b has an engagement surface 25, 26 on its inner periphery that engages with the outer surface 10a of the squib. Each of these engagement surfaces 25, 26 comprises an inner surface that fits the outer surface of the corresponding squib and wraps and holds the squib. When the two holders 18a and 18b are fitted together, the engagement surfaces 25 and 26 grip the squib and fix the squib inside the holder. These holders 18a and 18b
Can be engaged with and disengaged from each other by an engaging portion described later.

The first holder 18a has a male screw 20 which is screwed onto the female screw 17 on its outer peripheral portion. Also, the second
The concave engaging portion 27 is provided at the end facing the holder 18b. As shown in FIG. 5, the concave engagement portion 27 is formed by four radial holes formed at equal intervals in the circumferential direction.

The second holder 18b is a flexible member made of synthetic resin, and has a convex engaging portion 28 which engages with the concave engaging portion 27 on the outer peripheral portion thereof. This convex engaging portion 28
As shown in FIG. 4, consists of four protrusions formed at positions corresponding to the concave engaging portions 27 and protruding in the radial direction.

When mounting the squib 10, the outer surface 10a of the squib is engaged with the engaging surface 25 of the first holder, and then the outer surface 10a of the squib is engaged with the engaging surface 26 of the second holder.
Are engaged to deform the second holder 18b to engage the convex engaging portion 28 with the concave engaging portion 27. In this way, the squib is gripped by the first and second holders, and then the first holder 18a is rotated and screwed to fix the squib to the central tubular body 1a of the housing (FIG. 3).

The inside 2 of the housing is circumferentially demarcated by a central tubular body 1a, the ignition device housing chamber 4 is inside the central tubular body, and the combustion chamber 5 and the coolant chamber 24 are outside thereof by a combustion ring 23. Further, a filter chamber 19 is formed surrounding the combustion chamber 5.

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 a combustion chamber is provided between the combustion chamber 5 and the coolant chamber 24. 5
The opening 8 for introducing the gas generated in 1. is provided, the coolant chamber 24 and the filter chamber 19 are communicated with each other by an opening (not shown), and the filter chamber 19 and the air bag (not shown) further have a coolant, An opening for introducing the gas that has passed through the filter, that is, an ejection port 9 is provided.

When a sensor (not shown) is activated by the impact, an electric signal is sent to the squib's priming agent to ignite the priming agent, which ignites the transfer charge 6. The high-pressure, high-temperature flame generated thereby passes through the opening 7 and ignites the gas generating agent in the combustion chamber 5. The gas generated in the combustion chamber 5 passes through the opening 8, passes through the coolant 12 and the filter 13, passes through the ejection port 9 and flows into the airbag.

[0017]

As described above, according to the present invention, the igniter can be easily loaded by the detachable first and second holders, and the first and second holders engage with each other to ignite the igniter. Hold and
Since the igniter can be fixed to the housing by screwing the first holder to the housing while holding the igniter, the igniter can be easily attached, and the work can be performed safely and in a short time. ..

[Brief description of drawings]

FIG. 1 is a half sectional view of a gas generator having fixing means for an igniter according to the present invention.

FIG. 2 is an exploded view of a squib holder that constitutes a fixing means of the igniter.

FIG. 3 is a cross-sectional view of a state where an igniter is fixed by a squib holder.

FIG. 4 is a plan view of a second holder.

FIG. 5 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Diffuser shell 3 Closure shell 6 Enhancer (transfer charge) 9 Spout (opening) 10 Squib (igniter) 17 Female screw 18 Squib holder 18a First holder 18b Second holder 20 Male screw 25 Engaging surface 26 Engaging surface 27 Concave engaging part 28 Convex engaging part

Claims (1)

[Claims] 1. A housing, a gas generator arranged in the housing, a fixing means for fixing an igniter constituting an ignition device of the gas generator to the housing, a housing and an airbag. A gas generator having an opening communicating with the gas generator for introducing gas generated by the gas generator into the airbag by an impact to protect an occupant from the impact, the fixing means engages with an outer surface of the igniter. The first and second holders have engaging surfaces for holding the igniter on the inner peripheral portion and are engageable with and disengageable from each other, and the first holder is a male screw screwed into a female screw engraved in the housing. And a concave engaging portion at an end portion facing the second holder, and the second holder includes a convex engaging portion that engages with the concave engaging portion. In a gas generator for an air bag, characterized by Means for fixing the igniter.