JP3041119B2 - Means for fixing igniter 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 gas generator for an air bag for protecting an occupant from an impact, and more particularly to a fixing means for an igniter.

[0002]

2. Description of the Related Art Conventionally, as a method of attaching an igniter to a gas generator, caulking, an adhesive or the like is generally used.

[0003]

However, fixing by caulking imposes a load on the igniter, which poses a problem in work safety. In addition, fixing with an adhesive requires a series of operations such as application, attachment, and drying, and has a problem that it takes a long time to attach (usually 24 hours).

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

[0005]

The means for fixing the igniter in the gas generator for an air bag according to the present invention comprises a housing,
A gas generator disposed in the housing, fixing means for fixing an igniter constituting an ignition device of the gas generator to the housing, and an opening communicating the housing and the airbag, In a gas generator which protects an occupant from a shock by introducing gas generated by the gas generator into the airbag by an impact, the fixing means engages with an outer surface of the igniter to engage the igniter. First and second holders each having a surface on an inner peripheral portion thereof; and a step portion for positioning the holders, wherein the first holder has a male screw that is screwed into a female screw engraved on a housing at an outer peripheral portion. Wherein the second holder is sandwiched between the step formed at a predetermined position of the housing and the first holder.

[0006] The first holder and the second holder hold the igniter by gripping the igniter by the engagement surfaces thereof. The first holder is fixed to the housing by screw means. Further, the second holder is sandwiched and fixed between the step formed on the housing and the first holder.

The step positions the holder at a predetermined position on the housing.

[0008]

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 a fixing means for an igniter according to the present invention. The housing of the gas generator includes a diffuser shell 1 and a closure shell 3. The diffuser shell 1 and the closure shell 3 have circular portions 1c and 3c, and peripheral wall portions 1d and 3d formed on the outer periphery of the circular portion, respectively. The diffuser shell 1 includes a central tubular body 1a formed integrally with the circular portion at the central portion of the circular portion 1c. The center tubular body 1a has a 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 tubular body 1a. A fixing means for gripping the igniter (squib 10) and fixing it to the housing, that is, a squib holder 18 is screwed to the female screw 17. This squib holder is, as shown in FIG.
8a and a second holder 18b. These holders 1
Each of 8a and 18b has an engaging surface 25, 26 which engages with the outer surface 10a of the squib on its inner periphery. Each of the engagement surfaces 25 and 26 has an inner surface which conforms to the outer surface of the corresponding squib, and holds the squib so as to wrap it. When the two holders 18a and 18b are brought together, the engaging surfaces 25 and 26 hold the squib and fix the squib inside the holder.

The first holder 18a has a male screw 20 screwed to the female screw 17 on the outer peripheral portion thereof. Also, the second
The holder 18b abuts on a step 21 formed on the inner peripheral portion of the central tubular body 1a, and is held and fixed between the step and the first holder 18a. The step 21 positions the squib holder 18 at a predetermined position in the housing.

When the squib 10 is mounted, the second holder 18b is engaged with the stepped portion 21 and the outer surface 10a of the squib is engaged with the engaging surface 26 of the second holder so that the squib is held in the second holder. 18b, and then the first holder 1
By rotating the screw 8a and fastening the screw, the engaging surface 25 of the first holder is engaged with the outer surface of the squib to grip the squib, and the second holder 18b is connected between the stepped portion and the first holder 18a. It is clamped and fixed in between (FIG. 3).

The inside 2 of the housing is defined in the circumferential direction by a central cylindrical body 1 a, an ignition device accommodating chamber 4 is provided inside the central cylindrical body, and a combustion chamber 5 and a coolant chamber 24 are provided 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 accommodating chamber 4 and the combustion chamber 5, and a combustion chamber is provided between the combustion chamber 5 and the coolant chamber 24. 5
An opening 8 for introducing the gas generated in the above is provided, the coolant chamber 24 and the filter chamber 19 are communicated with each other by an opening (not shown), and further, a filter, An opening for introducing gas that has passed through the coolant, that is, a jet port 9 is provided.

When a sensor (not shown) is actuated by an impact, an electric signal is sent to the squib's priming and the priming is ignited, whereby the transfer charge 6 is ignited. 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, and flows into the airbag through the ejection port 9.

[0016]

According to the present invention, as described above, the igniter is gripped by the first and second holders, and the igniter is fixed to the step position of the housing by screwing the first holder. Therefore, the igniter can be fixed at an arbitrary position, the igniter can be easily mounted, and the operation can be performed safely and in a short time.

[Brief description of the drawings]

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

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

FIG. 3 is a cross-sectional view of a state in which the igniter is fixed by a squib holder.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 diffuser shell 3 closure shell 6 enhancer (explosive charge) 9 spout (opening) 10 squib (igniter) 17 female screw 18 squib holder 18 a first holder 18 b second holder 20 male screw 21 shoulder 25 engaging surface 26 engagement Meeting

Claims (1)

(57) [Claims] 1. A housing, a gas generator provided in the housing, fixing means for fixing an igniter constituting an ignition device of the gas generator to the housing, and the housing and the airbag. An opening communicating with the gas generator, wherein the gas generated by the gas generator by the impact is introduced into an airbag to protect an occupant from the impact, wherein the fixing means engages with an outer surface of the igniter. First and second holders having an engagement surface for gripping an igniter on an inner peripheral portion thereof;
And a step portion for positioning these holders.
The outer peripheral portion has a male screw screwed into a female screw engraved on the housing, and the second holder is provided between the step portion formed at a predetermined position of the housing and the first holder. Fixing means for the igniter in the gas generator for an air bag, which is sandwiched between the igniters.