JPH0687399A - Ignitor fixing means for air bag gas generator - Google Patents

Abstract

PURPOSE:To provide an air bag gas generator having an ignitor fixing means which allows safe, easy mounting of an ignitor. CONSTITUTION:A cylindrical holder 18 to hold an ignitor 10, a male screw 20 carved on its outer periphery, a flange portion formed at the rear end of the holder, a female screw 21 carved in a housing to thread the male screw therein and an engagement portion formed at an axially preset position on the housing to engage the flange portion therewith are contained in an ignitor fixing means. The flange portion has an arcuate plane with an axially preset width and a center angle of 90 deg., an engagement plane placed at the front end of the arcuate plane to be axially extended in the rotational direction of the holder with the length being a quarter of a screw pitch and an inclined plane starting at one end opposite to the front end of the engagement plane and terminating at the rear end of the plane with an inclination equivalent to the leading angle of the screw. The engagement portion exists in an axially preset position on the housing and has its width and depth, at least enough to allow fitting of the flange portion.

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 or the like has 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 is a work safety problem. 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). Further, when fixing at a predetermined position in the circumferential direction, there is a problem that the work must be performed while confirming the position at the time of mounting.

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

[0005]

The fixing means of the igniter in the gas generator of the present invention is a housing, a gas generating agent disposed in the housing, and an igniter for burning the gas generating agent. A gas for protecting the occupant from impact by introducing a gas generated from the gas generating agent by combustion into the airbag by a fixing means for fixing the vehicle to the housing and an opening communicating the housing with the airbag. In the generator, the fixing means includes a cylindrical holder for holding the igniter, a male screw engraved on an outer peripheral portion of the holder, a flange portion formed on a rear end portion of the holder, and an engraved portion on the housing. The male screw is provided and includes an internal thread to which the male screw is screwed, and an engaging portion which is formed at a predetermined axial position of the housing and which engages with the flange portion. The flange portion has a center angle of 90 degrees having a predetermined radial width. Arc-shaped plane, an engagement surface extending in the axial direction at the front end of the plane with respect to the rotation direction of the holder, and having a length of ¼ of the pitch of the screw, and an opposite side of the engagement surface from the front end. An inclined surface whose starting point is one end of the housing and whose end point is the rear end of the plane with an inclination angle corresponding to the lead angle of the screw, and the engaging portion is located at a predetermined axial position of the housing and is perpendicular to the axial direction. A flat surface and an arcuate groove formed in the flat surface and having a central angle of 90 °. The groove has a width and a depth at least capable of fitting the flange portion, and at the front end of the groove. It has a stopper surface with which the engagement surface of the flange portion abuts.

The cylindrical holder holds the igniter. This holder is fixed to the housing by screw means. The holder advances by one pitch each time it is rotated by the screw means, and advances until the flange portion formed on the rear end portion of the holder reaches the plane of the engaging portion formed on the housing. This plane is at a predetermined position in the axial direction of the housing, and further rotation of the holder is blocked by this plane, but a groove is formed in this plane, and the flange portion of the holder fits into this groove, and further rotation of the holder Is possible. The rotation of the holder is stopped by bringing the engagement surface of the flange portion into contact with the stopper surface of the engagement portion. In this way, the holder is axially positioned when the flange of the holder reaches the flat surface of the engaging portion, and is also circumferentially positioned by the groove and the stopper surface formed on this flat surface, and the ignition is performed. The container is axially and circumferentially positioned and fixed to the housing via the holder.

[0007]

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 a fixing means for an igniter according to the present invention. The housing in the present 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. Also, the closure shell 3
It has a hole 3a into which the central tubular body 1a can be fitted. A female thread 21 into which a male thread 20 of a holder described later is screwed is formed on the inner peripheral portion of the central tubular body 1a.

The igniter or squib 10 is a holder 1
It is gripped by 8. The holder 18 is a cylindrical hollow member, and includes a first holder 18a and a second holder 18b.
Consists of. The first holder 18a has a male screw 20 that is screwed into the female screw 21 and is engraved on the outer circumference, and the squib 10 is formed on the inner circumference.
It is formed in a shape that fits the outer shape of. Further, the second holder 18b is formed in a shape that fits the outer circumference of the squib that also holds the inner circumference of the second holder 18b, and is releasably engaged with the first holder 18a by an appropriate engaging means. This first holder 1
A flange portion 30 is formed at the rear end portion of 8a. The flange portion 30 has an arc-shaped flat surface 30a having a predetermined radial width 1 and a central angle O of 90 °, and a holder rotation direction A.
An engagement surface 30b extending axially at the front end 31 of the plane 30a and having a length d of a quarter of the pitch of the screw
And an inclined surface 30c having one end on the side opposite to the front end of the engagement surface 30b as a starting point and having an inclination angle corresponding to the lead angle β of the screw and ending at the rear end 32 of the flat surface. The front end 31 of the flange portion is located at a point 33 where the fully threaded portion of the male screw 20 begins.

A flat surface 22 perpendicular to the axial direction is formed at a predetermined axial position of the central cylindrical body 1a, and a groove 40 with which the flange portion 30 of the holder is engaged is formed in the flat surface 22. The groove 40 is an arc-shaped groove having a central angle O ′ of 90 °. The groove has a radial width in which the flange portion 30 can fit. Further, the groove is inclined from the rear end 42 of the groove along the inclined surface 30c of the flange portion to the front end 4 of the groove.
It has a bottom surface 40b whose end point is 1. Note that the bottom surface may be horizontal and may have at least a depth at which the flange portion 30 can be fitted. Further, the front end 41 of the groove has an axial stopper surface 40a with which the engagement surface 30b of the flange portion abuts. The rear end 42 of the groove is at a point 43 where the fully threaded portion of the female thread 21 begins.

When attaching the holder 18 to the housing,
First, the squib 10 is engaged with the first holder 18a, and then the second holder 18b is engaged with the first holder 18a to grip the squib 10. The meshing with the male screw 20 starts at a point 43 where the completely threaded portion of the female screw 21 starts. Point 33 where the complete screw part in male screw 20 starts
Has a front end 31 of the flange portion, and a rear end 42 of the groove at a point 43 where the fully threaded portion of the female screw 21 starts. The engaging surface 30b formed at the front end 31 of the flange portion advances by one pitch (p) for each rotation, and is at the position of the point 43 (the rear end position of the groove). The holder is n
It advances by p, and one end 34 of the engaging surface reaches the plane 22 (dashed line in FIG. 6). Further, when the flange portion 30 is rotated by 90 °, the one end 34 of the engaging surface advances in the axial direction by a quarter pitch, and the engaging surface 30b moves by 90 ° in the circumferential direction to form the groove stopper surface 40a. Abut. In this way
The holder is always positioned and fixed to the housing at predetermined axial and circumferential positions.

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 actuated by the impact, an electric signal is sent to the squib's priming charge, which ignites the priming charge, thereby igniting 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, the coolant 12, the filter 13 and the injection port 9 and flows into the airbag.

[0015]

Since the present invention is constructed as described above, the igniter can be axially and circumferentially positioned with respect to the housing at the same time, and the igniter can be fixed at that position. Therefore, the igniter can be easily attached, and the work is safe and can be performed 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 a plan view of a holder.

FIG. 3 is a plan view of an engaging portion formed on a central tubular body.

FIG. 4 is a perspective view of a holder.

5 is a perspective view of an engaging portion in the central tubular body taken along the line BB in FIG.

FIG. 5 is a schematic view showing a state of engagement.

[Explanation of symbols]

 1 Diffuser shell 3 Closure shell 9 Jet outlet (opening) 10 Squib (igniter) 18 Holder 20 Male screw 21 Female screw 22 Flat surface 30 Flange portion 30a Flat surface 30b Engaging surface 30c Sloping surface 40 Groove (engaging portion) 40a Stopper surface 40b Bottom surface

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 29, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[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 a plan view of a holder.

FIG. 3 is a plan view of an engaging portion formed on a central tubular body.

FIG. 4 is a perspective view of a holder.

5 is a perspective view of an engaging portion in the central tubular body taken along the line BB in FIG.

FIG. 6 is a schematic view showing a state of engagement.

[Explanation of reference numerals] 1 diffuser shell 3 closure shell 9 ejection port (opening) 10 squib (igniter) 18 holder 20 male screw 21 female screw 22 flat surface 30 flange portion 30a flat surface 30b engaging surface 30c inclined surface 40 groove (engaging portion) 40a Stopper surface 40b Bottom surface

Claims (1)

[Claims] 1. A housing, a gas generating agent disposed in the housing, a fixing means for fixing an igniter for burning the gas generating agent to the housing, and the housing and the airbag are communicated with each other. A gas holder for protecting an occupant from an impact by introducing a gas generated from the gas generating agent by combustion into an airbag, wherein the fixing means is a cylindrical holder for holding an igniter. When,
A male screw engraved on the outer peripheral portion of the holder, a flange portion formed on the rear end portion of the holder, a female screw engraved on the housing and into which the male screw is screwed, and formed at a predetermined axial position of the housing. An engaging portion with which the flange portion engages, the flange portion having an arc-shaped plane having a predetermined radial width and a central angle of 90 °, and an axial direction at a front end of the plane with respect to a rotation direction of the holder. 1/4 of the pitch of the extended screw
And an inclined surface having one end opposite to the front end of the engagement surface as a starting point and an inclination angle corresponding to the lead angle of the screw and having the rear end of the plane as an end point. The engaging portion has a plane at a predetermined axial position of the housing and is perpendicular to the axial direction, and a central angle formed on the plane is 9
It comprises an arcuate groove forming 0 °, and the groove has a width and a depth at least capable of fitting the flange portion, and a stopper surface with which the engaging surface of the flange portion abuts at the front end of the groove. Fixing means for an igniter in an airbag gas generator, characterized by having.