JP3054695U - Ignition means for gas generator for airbag having improved seal structure - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an ignition means having an improved seal structure when attached to a gas generator housing for an airbag. A cylindrical member having one end closed and the other end open and having a flange at its open end, and an initiator housed in the cylindrical member and provided with a collar at a base portion, wherein the flange is provided. The upper surface of the collar is closely engaged with the upper surface of the collar, the upper surface of the flange is provided with an O-ring, and the collar is provided with an ignition means mounting hole provided in the housing of the gas generator for an air bag. The O-ring is fixed to the flange, and the O-ring is formed in the flange and the upper hole.
Ignition means for a gas generator for an airbag having a seal structure, which is pressed between a step portion for disposing a ring.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to an ignition means attached to a housing of an airbag gas generator for protecting an occupant from an impact, and has a feature in a seal structure thereof.

[0002]

[Prior art]

 FIG. 7 shows a conventional seal structure. The ignition means 30 is composed of a collar 31, a sleeve 33 which is fitted into and recessed from the collar 31 and whose both ends are open, and an initiator 34 which is fitted into the sleeve 33. When attaching the ignition means 30, the sleeve 33 and the collar 31 are fixed to the hole 35 of the housing by the caulking portion 36, the initiator 34 is inserted into the sleeve 33, and then the sealing material 37 is injected into the gap in the sleeve 33. You.

[0003]

[Problems to be solved by the invention]

 In the above-described conventional seal structure, it is difficult to uniformly flow the sealing material in this portion because the gap between the inner peripheral surface of the sleeve and the outer peripheral surface of the initiator is narrow. For this reason, there is a possibility that a cavity may be formed in the sealing material, and in the worst case, the cavities communicate with each other, and as a result, there is a problem that the gas generator cannot maintain airtightness. If the airtightness is incomplete, the gas generating agent inside the gas generator will absorb moisture, so that the initial performance of the gas generator will not be maintained and the desired performance will not be exhibited when the gas generator operates. Occurs.

[0004] Accordingly, an object of the present invention is to provide a novel ignition device sealing structure that solves the above-mentioned problems of the prior art.

[0005]

[Means for Solving the Problems]

 The present invention includes a tubular member having one end closed and the other end open, a flange provided at the open end, and an initiator housed in the tubular member and provided with a collar at a base portion. The lower surface of the flange and the upper surface of the collar are closely engaged with each other, and an O-ring is provided on the upper surface of the flange. The collar is for mounting an ignition means provided on a housing of a gas generator for an air bag. An airbag having a seal structure, wherein the airbag is fixed to a hole, and the O-ring is pressed between the flange and a step portion for disposing an O-ring formed in the upper hole. It is a means of igniting a gas generator.

[0006] The closed end of the tubular member preferably has a fragile portion that can be broken when the ignition means is activated.

[0007] The seal structure of the ignition means of the present invention includes a tubular member having a bottom and a flange. That is, the cylindrical member has one end closed and the other end open, and has a flange at the open end. When the initiator is housed in the tubular member, the collar at the base of the ignition means engages with this flange. The collar is fixed to the hole by fixing means. The O-ring is pressed between the flange and the step when the collar is secured.

[0008] Moisture attempting to enter the gas generator through the space between the tubular member and the initiator is blocked by the closed end of the tubular member. In addition, moisture that tries to enter the gas generator through the space between the cylindrical member and the hole is prevented by the O-ring.

During operation of the ignition means, a high-temperature and high-pressure gas is generated from the initiator. This gas pressure destroys the closed end or the fragile portion of the tubular member, and releases the closed end of the tubular member. Gas flows into the combustion chamber through the open closed end, and ignites a gas generating agent (gas generating means) in the combustion chamber.

[0010] Examples of the fixing means include a caulking, a snap ring, and a screw.

[0011]

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 is a partial cross-sectional view showing a main part of the gas generator. The gas generator has a housing 2 having a gas outlet 1. The housing 2 is defined at an ignition means housing chamber 3 defined at a central portion and outside the ignition means housing chamber 3. A combustion chamber 4 and a coolant / filter chamber 5 defined outside the combustion chamber 4 are provided. An ignition means 6 is provided in the ignition means accommodating chamber 3, and a gas generating means for generating gas by being ignited by the ignition means 6 in the combustion chamber 4, that is, a canister (FIG. A coolant and a filter (both not shown) for cooling and purifying the combustion gas generated in the canister are provided in the coolant / filter chamber 5.

A passage 7 is provided between the ignition means accommodating chamber 3 and the combustion chamber 4 for transmitting the flame generated in the ignition means accommodating chamber 3 into the combustion chamber 4. A plurality of discharge ports 8 for the combustion gas generated in the combustion chamber 4 are arranged in the circumferential direction between the filter chambers 5, and further, between the coolant / filter chamber 5 and the airbag (not shown). A plurality of the outlets 1 are provided in the circumferential direction.

FIG. 2 is an enlarged sectional view of a main part showing the ignition means having the seal structure of the present invention shown in FIG. The housing 2 has a hole 9 for mounting ignition means, which is open to the outside of the housing. The hole 9 has a step 10 for disposing the O-ring 11. The hole 9 has a small-diameter portion 13 having an inner diameter slightly larger than the outer diameter of the tubular member 12 described later, a locking portion 16 for locking the collar 15 of the ignition means 6, and a locking portion 16. And a caulking portion 17 for fixing the ignition means 6 to the hole 9 via a collar 15 locked to the hole. The locking portion 16 is formed at a position where the O-ring 11 is elastically compressed between the tubular member 12 and the step portion 10. The O-ring preferably has heat resistance, for example, nitrile rubber is used.

The ignition means 6 has a collar 15 at the base. The collar can be formed from metal or resin. This collar is preferably formed simultaneously with the manufacture of the initiator. For example, a separately formed collar can be fixed to the initiator, or the initiator and the collar can be formed integrally.

The ignition means 6 includes a tubular member 12 having one end closed and the other end opened. The tubular member 12 has a flange 19 at an open end thereof to which the collar 15 at the base of the ignition means is locked. The tubular member can be formed by pressing from a thin metal having corrosion resistance, preferably aluminum, stainless steel, or the like. The collar 15 is fixed to the hole 9 by the caulking portion 17 in a state where the O-ring 11 is pressed between the flange 19 and the step portion 10.

The closed end 20 of the tubular member 12 has a fragile portion which can be broken by gas pressure generated when the ignition means is operated. This fragile portion is constituted by making the closed end relatively thin. As a result, a stable burst pressure for breaking the fragile portion is obtained, which contributes to steady ignition of the gas generating agent.

FIG. 3 shows another example of the fragile portion. This fragile portion is constituted by a radial groove 21 having a predetermined depth. When the gas pressure generated when the ignition means operates acts on the closed end of the cylindrical member 12 ', the closed end is opened radially along the groove 21. According to this, the thickness of the tubular member can be made uniform.

FIG. 4 shows another example of a fixing means for fixing the collar 15 ′ to the hole 9. The collar 15 'has a flat bottom surface 24 and a conical outer peripheral surface 25. The fixing means includes a snap ring 22 shown in FIG. 5 and a circumferential groove 23 with which the snap ring 22 engages. The circumferential groove 23 is formed in the hole 9, and a snap ring 22 engages in the circumferential groove 23 in an elastically contracted state, and a collar 15 ′ is held between the snap ring 22 and the locking portion 16. Has been fixed.

FIG. 6 shows an example in which the fixing means is constituted by screws. The collar 15 "has a cylindrical portion 26, and a screw 27 is formed in the cylindrical portion 26, and a female screw 28 to be screwed thereto is formed at a corresponding position of the hole portion 9. The flange 19 of the member presses the O-ring 11, and the collar 15 ″ is fixed to the hole 9 with the O-ring 11 pressed between the flange 19 and the step 10.

[0021]

[Effect of the invention]

 Since the present invention is configured as described above, the sealing material used in the conventional sealing structure can be eliminated. Therefore, the work of injecting the sealing material can be abolished, and the problem of the moisture absorption of the gas generating agent and the like due to the cavity in the sealing material can be solved.

[0022] By attaching the initiator of the present invention having the seal structure configured as described above to the hole, a seal is formed between the hole and the ignition means. Therefore, according to the present invention, a seal for keeping the inside of the gas generator airtight can be easily achieved. As a result, the initial performance of the gas generator is maintained, and a gas generator capable of exhibiting the desired performance during operation can be realized.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a gas generator for an airbag to which an ignition means having a seal structure of the present invention is attached.

FIG. 2 is an enlarged sectional view of an ignition means having the seal structure shown in FIG.

FIG. 3 is a perspective view of another embodiment of the weak portion of the tubular member provided in the ignition means of the present invention.

FIG. 4 is a partial sectional view of another embodiment of the fixing means suitable for the ignition means of the present invention.

FIG. 5 is a perspective view of the fixing means.

FIG. 6 is a sectional view of still another embodiment of the fixing means suitable for the ignition means of the present invention.

FIG. 7 is a partial sectional view showing a conventional sealing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge port 2 Housing 3 Ignition means accommodating chamber 4 Combustion chamber 5 Coolant / filter chamber 6 Ignition means 9 Hole 10 Step 11 O-ring 12 Tubular member 15 Collar 19 Flange

Claims (2)

[Utility model registration claims] 1. One end is closed and the other end is open,
It has a cylindrical member provided with a flange at its open end, and an initiator housed in the cylindrical member and provided with a collar at the base. The lower surface of the flange and the upper surface of the collar are closely engaged with each other. An O-ring is provided on an upper surface of the flange, and the collar is fixed to an ignition means mounting hole provided in a housing of the gas generator for an air bag;
The ignition means for an airbag gas generator having a seal structure, wherein the O-ring is pressed between the flange and a step formed in the upper hole for disposing the O-ring. 2. The ignition means according to claim 1, wherein the closed end of the tubular member has a fragile portion which can be broken when the ignition means is operated.