JPH05213149A - Gas generator for air bag having detonator mounting structure - Google Patents

Abstract

PURPOSE:To make mounting of a detonator safe and easy by forming a space between a sensor housing chamber and an ignitor chamber of a gas generator so that the space abuts on bothe the chamber, and providing a means for fixing a donator-piece for holding the detonator in the space. CONSTITUTION:A gas generator is composed of a diffuser shell 1 and a closure shell 3, and a space 2 is formed by the closure shell 3 and the diffuser shell 1. The inside of the space 2 is confined by an inner tube 1d of the diffuser shell 1 in the circumferential direction to form a sensor housing chamber 14 in the inner tube part 1d, and an ignitor chamber 17 is formed in the circular part 1b of the diffuser shell 1, namely in the upper part of the sensor housing chamber 14. A space formed between the sensor housing chamber 14 and the ignitor chamber 17 is used as a detonator storage chamber 20 in order to fix a detonator-piece 21 by a screw means 22. The detonator-piece 21 has a hole 21b, in which a detonator 11 is loaded. Besides, a projected part 21a is provided in the middle of the detonator-piece 21 so as to penetrate into the transfer charge chamber 17.

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 airbag for protecting an occupant from an impact, and more particularly to a mounting structure of a detonator in a mechanical ignition type gas generator.

[0002]

2. Description of the Related Art There are two types of gas generators, an electric ignition type and a mechanical ignition type. Even though an electric ignition type gas generator ignites an igniter (squib) by heat generation of an electric current. On the other hand, in the mechanical ignition type gas generator, the detonator is operated by a pure mechanical sensor, and its advantage is that no electric wiring is required and the cost is low.

In the conventional mechanical ignition type gas generator,
A mechanical sensor is arranged in the sensor accommodating chamber in the housing, and the detonator is directly attached to the wall of the sensor accommodating chamber by caulking or the like.

[0004]

Since the above-mentioned sensor accommodating chamber is narrow and the place where the detonator is mounted is deep, it was not easy to mount it. In addition, there is a risk that the detonator may be erroneously impacted at the time of mounting, and thus the transfer charge or the gas generating agent may be burned.

Therefore, it is an object of the present invention to provide a novel gas generator that solves the above-mentioned problems of the prior art.

[0006]

SUMMARY OF THE INVENTION An air bag gas generator having a detonator mounting structure of the present invention includes a housing,
A sensor accommodating chamber disposed in the housing and accommodating a mechanical sensor, a transfer charge chamber containing a transfer charge ignited by a detonator operated by the mechanical sensor, and a gas generating agent ignited by the transfer charge A gas generator for protecting a passenger from a shock by introducing a gas generated in the combustion chamber due to a shock into the air bag, the gas generator having a combustion chamber accommodating the The generator has a space in which one end is in contact with the sensor storage chamber and the other end is in contact with the transfer charge chamber between the sensor storage chamber and the transfer charge chamber, and has a shape that fits in the space. And a detonator piece having a hole for loading the detonator, wherein the detonator piece for holding the detonator is arranged in the space by a fixing means.

In this gas generator, the detonator piece for holding the detonator is provided separately. This detonator piece is arranged in the space by a fixing means. This space is formed between the sensor storage chamber and the transfer charge chamber, and both ends are in contact with the sensor storage chamber and the transfer charge chamber, respectively. Since the detonator piece is configured as a separate body, the detonator can be attached to the detonator piece separated from the gas generator body. Therefore, the mounting is facilitated, and since the mounting can be performed away from the transfer charge or the gas generating agent, the detonator can be mounted safely. The detonator piece to which the detonator is attached is attached to the gas generator body by a fixing means. In this way, the detonator can be safely and easily loaded into the gas generator.

As the fixing means, various conventional fixing means can be used if necessary.

[0009]

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 sectional view of the present gas generator. The housing in this gas generator comprises a diffuser shell 1 and a closure shell 3. The diffuser shell 1 has a peripheral wall portion 1c and a flange portion 1a which is integrally formed at the tip of the peripheral wall portion 1c and extends in the radial direction. Further, the diffuser shell 1 has a circular portion 1b and an inner cylindrical portion 1d formed concentrically with the peripheral wall portion 1c at the center of the circular portion.

The closure shell 3 has an annular portion 3a, a peripheral wall portion 3b formed on the outer peripheral portion of the annular portion 3a, and a central hole 3c into which the inner cylindrical portion 1d of the diffuser shell fits. A circumferential projection 1e is integrally formed on the lower surface of the flange portion 1a of the diffuser shell, and the tip end of the peripheral wall portion 3b of the closure shell is fitted inside the circumferential projection 1e. A void 2 is formed with the shell 1.

The space 2 is circumferentially delimited by the inner cylindrical portion 1d, and the sensor accommodating chamber 14 is demarcated inside the inner cylindrical portion.
A recess, that is, a transfer charge chamber 17 is formed in the circular portion 1b of the diffuser shell in the upper part of the sensor housing chamber 14. Further, the combustion chamber 5 is demarcated on the outer side of the inner cylindrical portion by a combustion ring 18, and a coolant / filter chamber 19 is formed so as to surround the combustion chamber 5.

A mechanical sensor 4 is accommodated in the sensor accommodating chamber 14, a transfer charge 6 is accommodated in the transfer charge chamber 17, and an annular canister container 10 is disposed in the combustion chamber 5. There is. The canister container 10 is a thin-walled container made of aluminum and is filled with a gas generating agent 15 inside. Further, the inside of the coolant / filter chamber 19 is demarcated by a retainer 16 into upper and lower stages, and the filter 12 is accommodated in the upper stage and the coolant 13 is accommodated in the lower stage.

A passage 7 for transmitting the flame of the transfer charge 6 to the combustion chamber 5 is provided between the transfer charge chamber 17 and the combustion chamber 5,
A plurality of openings 8 for introducing gas generated in the combustion chamber 5 are provided in the circumferential direction between the combustion chamber 5 and the coolant / filter chamber 19.
A plurality of exhaust ports 9 for introducing the coolant and the gas passing through the filter are provided in the circumferential direction between the air bag 9 and the airbag (not shown).

The gas generator comprises a detonator piece 21 for holding the detonator 11. The detonator piece 21 is a disk-shaped member, and has a protrusion 21a at the center thereof.
1a is fitted in the transfer charge chamber 17. Further, a hole 21b is formed at a predetermined position of the detonator piece 21, and the detonator 11 is loaded in the hole 21b. Detonator piece 21
Is configured as a separate body, so that the detonator piece can be separated from the housing, and the detonator can be set on the detonator piece in the separated state.

An accommodation space 20 for accommodating the detonator piece 21 is formed between the sensor accommodation chamber 14 and the transfer charge chamber 17. This space 20 has one end in contact with the sensor housing chamber 14 and the other end in contact with the transfer charge chamber 17. A detonator piece 21 is housed in this space 20, and the detonator piece 21 is a fixing means,
That is, it is fixed in the space 20 by the screw means 22. The screw means 22 includes a male screw formed on the outer peripheral portion of the detonator piece 21 and a female screw formed on the inner peripheral portion of the inner cylindrical portion 1d. At the bottom of the detonator piece 21, an engaging hole for a mounting tool or a positioning hole 21c for the mechanical sensor 4 is provided.
Is provided, whereby the fitting can be fitted into the engaging hole 21c and the detonator piece 21 can be screwed by turning, and the protrusion of the mechanical sensor 4 can be fitted into the hole 21c to mechanically The mechanical sensor 4 can be positioned with respect to the detonator piece 21 so as to associate the firing pin of the sensor with the detonator of the detonator piece. .

When mounting the detonator, prepare a detonator piece with the detonator set, first load the transfer charge 6 in the transfer charge chamber 17, and then use the fitting to attach the detonator piece 21 holding the detonator 11. After screwing, the mechanical sensor 4 is finally housed in the sensor housing chamber 14, positioned, and fixed by the holding ring 23. An O-ring 24 is provided between the detonator piece 21 and the mechanical sensor 4 to protect the detonator 11 from moisture.

When the firing pin of the mechanical sensor 4 strikes the detonator 11 due to the impact, the detonator 11 is ignited, and the transfer charge 6 is ignited. The high-pressure, high-temperature flame generated thereby passes through the passage 7 and breaks the wall of the canister container 10 to ignite the gas generating agent 15 inside. The gas generated in the combustion chamber 5 is uniformly ejected from the opening 8, and the ejected gas is
Through the coolant 13 and then through the filter 12,
It flows into the airbag through the outlet 9.

The structure shown in FIGS. 2 to 5 is the same as that shown in FIG. 1 except that the fixing means is different from that shown in FIG. In FIG. 2, the detonator piece 21 is fixed by a C ring 25. A notch portion 21d is provided in the circumferential direction on the outer peripheral portion of the bottom portion of the detonator piece 21, and a circumferential groove 26 is provided on the inner peripheral portion of the inner cylindrical portion 1d. When the detonator piece 21 is arranged in the space 20, and then the C ring 25 is inserted to reach the position of the circumferential groove 26, the C ring 25 expands outward in the radial direction and the cutout portion 21d.
Then, the detonator piece 21 is fixed by being fitted in the circumferential groove 26.

In FIG. 3, the outer diameter of the detonator piece 21 is formed to be slightly larger than the inner diameter of the inner cylindrical portion 1d at the base portion thereof, and therefore the detonator piece 21 is press-fitted between the outer peripheral surface and the inner peripheral surface of the inner cylindrical portion. The surface 27 is formed, and thus the detonator piece 21 is press-fitted and fixed in the space 20.

In FIG. 4, the detonator piece 21 is fixed by a detonator piece retainer 28. The detonator piece retainer 28 can be made of, for example, an elastic material,
After disposing the detonator piece 21 in the space 20, the mechanical sensor 4 can be positioned with respect to the detonator piece 21, and then the detonator piece retainer 28 can be press-fitted and fixed between the mechanical sensor 4 and the inner cylindrical portion 1d. .

FIG. 5 shows the detonator piece 21 fixed by a retainer 29. The retainer 29 has a ring shape, and an inward flange 29a is formed on one end side, and the inward flange 29a is fitted in the circumferential notch 21d of the detonator piece 21. The retainer 29 can be fixed to the inner surface of the inner cylindrical portion 1d by pressure bonding or adhesion.

In FIG. 6, the detonator piece 21 is fixed to the circular portion 1b of the diffuser shell by bolt fastening. In this case, the transfer charge chamber 30 is formed in a ring shape, and the female screw 31 is formed in the hole formed in the center of the circular portion 1b.
Is engraved. Further, a stepped hole 32 is formed in the center of the detonator piece 21, and the screw bolt 3 is inserted into the stepped hole 32.
The head 33a of No. 3 is engaged. The detonator piece is securely fixed to the circular portion 1b by tightening the screw bolt 33.

[0024]

According to the present invention, the detonator can be attached to the detonator piece separated from the gas generator body, and the detonator piece with the detonator can be easily attached to the gas generator body. The detonator can be easily installed, and the installation can be performed away from the transfer charge or the gas generating agent to ensure safety.

Further, according to the present invention, a space for disposing the detonator piece is formed between the sensor housing chamber and the transfer charge chamber. Therefore, it is possible to dispose the detonator piece made of a resin material in this space, and in this case, the weight reduction of the gas generator can be realized.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing another embodiment of the present gas generator.

FIG. 3 is a sectional view showing another embodiment of the present gas generator.

FIG. 4 is a sectional view showing another embodiment of the present gas generator.

FIG. 5 is a sectional view showing another embodiment of the present gas generator.

FIG. 6 is a cross-sectional view showing another embodiment of the present gas generator.

[Explanation of symbols]

 1 Diffuser Shell 3 Closure Shell 4 Mechanical Sensor 5 Combustion Chamber 9 Discharge Port 11 Detonator 14 Sensor Housing 17 Transfer Charge Chamber 20 Space 21 Detonator Piece

Claims (1)

[Claims] 1. A housing, a sensor accommodating chamber disposed in the housing and accommodating a mechanical sensor, a transfer charge chamber containing a transfer charge ignited by a detonator operated by the mechanical sensor, It has a combustion chamber that stores a gas generating agent that is ignited by explosives, and an opening that connects the housing and the airbag, and introduces the gas that is generated in the combustion chamber due to impact into the airbag to protect the occupant from the impact. In the gas generator, the gas generator has a space between the sensor housing chamber and the transfer charge chamber, one end of which is in contact with the sensor storage chamber and the other end of which is in contact with the transfer charge chamber, and which is fitted into the space. And a detonator piece having a hole for loading a detonator on one end side,
A gas generator for an air bag having a detonator mounting structure, wherein a detonator piece for holding a detonator is arranged in the space by a fixing means.