JP2938648B2 - Gas generator for airbag with combustion vessel - 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 which protects an occupant from an impact, and more particularly to a combustion vessel constituting the gas generator.

[0002]

2. Description of the Related Art With respect to a conventional gas generator, a gas generating device includes a canister container filled with a gas generating agent, the canister container being covered on the outside by a combustor cup, which has a plurality of gas discharge ports for discharging gas. Is provided so that gas generated in the canister container is ejected from the through hole.

[0003] The canister container is thin (generally 0.1 to
(0.2 mm) aluminum container, formed by deep drawing.

[0004]

The canister container cannot be squeezed at one time because of the deep drawing of an ultra-thin plate, but is squeezed in several steps. Therefore, the cost of the mold becomes large, and much time and labor are required until the product is manufactured. In particular, when used in a gas generator, a high dimensional accuracy (particularly regarding the wall thickness) is required so as not to affect the combustion performance, so that advanced technology is required.

[0005] Further, since the canister container is a thin-walled container made of aluminum, the strength is low, and the internal filling material moves due to vibration or the like, so that the canister container is easily damaged. As a result, the sealability of the canister container may be impaired, and the gas generating agent may absorb moisture, which may adversely affect the operation of deploying the airbag in an emergency. Therefore, a large amount of cushions, which are not directly related to the performance of the gas generator, must be provided in order to prevent vibration of the filling inside the canister container.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel gas generator for an airbag which solves the above-mentioned problems of the prior art.

[0007]

According to the present invention, there is provided a gas generator for an airbag provided with a combustion container according to the present invention, comprising a housing, a gas generator arranged in the housing, and an opening communicating the housing with the airbag. A gas generator for introducing a gas generated in the gas generator by an impact into an airbag to protect an occupant from the impact, wherein the gas generator is constituted by a combustion container in which a gas generating agent is filled. A bottom portion having a center hole, an inner cylinder portion provided at a peripheral portion of the center hole at the bottom portion, an outer cylinder portion provided at an outer peripheral portion of the bottom portion, and the outer cylinder portion; And a ring-shaped combustion chamber formed between the inner cylinder portion and containing the gas generating agent, and a lid member for sealing the combustion chamber. The inner cylinder portion is configured to supply a flame of an ignition device to the combustion chamber. Has an opening to introduce into the
The opening is sealed by a breakable seal member, and the outer cylindrical portion has an ejection hole for ejecting combustion gas of the gas generating agent, and the ejection hole is sealed by the breakable seal member. It is characterized by the following.

The combustion vessel has an annular combustion chamber for accommodating a gas generating agent, an opening for introducing a flame from an igniter into the combustion chamber, and a discharge hole for discharging combustion gas of the gas generating agent. Is formed. These openings and ejection holes are each sealed by a breakable seal member to prevent the gas generating agent contained therein from absorbing moisture. When the gas generator is operated, the flame from the ignition device breaks through the wall of the seal member, enters the combustion chamber through the opening, and ignites the gas generating agent. The combustion gas of the gas generating agent breaks through the wall of the seal member and is ejected from the ejection hole.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view of the present gas generator.
The housing of the gas generator includes a diffuser shell 1 and a closure shell 3 which forms a space 2 together with the diffuser shell 1. The diffuser shell 1 and the closure shell 3 have circular portions 1a and 3a, and peripheral wall portions 1b and 3b formed on the outer periphery of the circular portion, respectively.

A plurality of rivets 26 are provided circumferentially on the circular portions 1a and 3a of the housing.
Numeral 6 connects the diffuser shell 1 and the closure shell 3 to each other near the peripheral wall of the housing.

In the space 2, an ignition device accommodating chamber 4 is defined at the center by a female screw member 16, and a combustion chamber 5 is defined outside by a combustion vessel 14 which will be described later.
, A coolant / filter chamber 19 is formed. The coolant / filter chamber 19 further holds the retainer 11.
Is defined in the upper and lower tiers.

In the igniter accommodating chamber 4, an enhancer (a transfer charge) 6 and a squib (igniter) 10 constituting an igniter are provided.
And are housed. The transfer charge 6 is loaded on a female screw member 16, and the squib 10 is loaded on a male screw member 17 screwed to the female screw member 16. The female screw member 16
Is provided with an opening 7 for transmitting the flame of the transfer charge 6 to the combustion container 14. These screw members 16 and 17 join the diffuser shell 1 and the closure shell 3 to each other at the center of the housing.

The combustion vessel 14 has a bottom portion 14a having a central hole 18, an inner cylindrical portion 14b formed integrally with the bottom portion at a peripheral portion of the central hole 18 of the bottom portion 14a, and an outer peripheral portion of the bottom portion integrated with the bottom portion. , An annular combustion chamber 5 formed between the outer cylinder part 14c and the inner cylinder part 14b, and a lid member 21 for sealing the combustion chamber 5. An inward flange 23 is provided at the tip of the inner cylindrical portion 14b.
However, an outward flange 24 is formed at the tip of the outer cylindrical portion 14c. The bottom part 14a, the inner cylinder part 14b, and the outer cylinder part 14c have a thickness that can withstand the pressure of the combustion gas of the gas generating agent. Further, the lid member 21 is in close contact with the circular portion 1a of the diffuser shell, so that the bottom portion 14a
The thickness can be reduced as compared with the thickness of the above. The lid member 21 has its inner edge 21 a caulked and fixed to the inward flange 23, and its outer edge 21 b caulked and fixed to the outward flange 24. Since the lid member 21 is thin, it can be easily fixed by swaging. The caulked portion is sealed with a sealant 27 such as an adhesive.

A gas generating agent 15 is accommodated in the combustion chamber 5, and the gas generating agent 15 is elastically held by a cushion 22.

The inner cylinder 14b has an opening 28 for introducing a flame from the ignition device into the combustion chamber 5. The openings 28 have an oval shape, and four openings 28 are formed at equal intervals in the circumferential direction. A sealing member, that is, a sealing tape 30, is attached to the inner peripheral surface of the inner cylindrical portion 14b so as to close the openings 28. The seal tape 30 forms a destructible wall in the combustion chamber, prevents the gas generating agent in the combustion chamber from absorbing moisture, and breaks down when the gas generator is operated to introduce a flame into the combustion chamber. ing. Further, the outer cylinder portion 14c has an ejection hole 31 for ejecting the combustion gas of the gas generating agent 15. The ejection hole 31 has a circular shape, and a plurality of the ejection holes 31 are formed in the base portion of the outer cylindrical portion in the circumferential direction. These ejection holes 31 are closed by a seal tape 30 attached to the outer peripheral surface of the outer cylindrical portion 14c. This sealing tape 30 forms a destructible thin wall in the combustion chamber, and when the gas generator is not operated, it serves to prevent moisture from the gas generating agent in the combustion chamber, and when it is operated, it is broken and the combustion gas is discharged from the combustion chamber 5 to the outside. Squirting is allowed. As the seal tape, for example, an aluminum seal tape having excellent environmental resistance can be used.

It is also possible to use this sealing tape instead of the lid member 21. For example, as shown in FIG. 3, the combustion chamber 5 is sealed by an annular sealing tape 30 '. The inner peripheral portion of the seal tape is fixed to the inward flange 23 of the inner cylindrical portion, and the outer peripheral portion is fixed to the outward flange 24 of the outer cylindrical portion. Further, each fixing portion is sealed with a sealant 27 such as an adhesive.

In the coolant / filter chamber 19, the filter 12 is accommodated in the upper stage, and the coolant 13 is accommodated in the lower stage so as to face the ejection hole 31. Further, between the coolant / filter chamber 19 and the airbag (not shown),
An opening 9 for introducing a coolant and a gas that has passed through a filter is provided.

When a sensor (not shown) is actuated by an impact, the squib 10 is ignited, whereby the transfer charge 6 is ignited. The high-temperature and high-pressure flame generated thereby passes through the opening 7, breaks through the wall of the seal tape 30 of the combustion chamber filled with the gas generating agent, and ignites the gas generating agent 15 inside. The gas generated in the combustion chamber 5 is sealed by the seal tape 30 of the combustion chamber.
Through the outlet hole 31, uniformly ejects through the ejection hole 31, passes through the coolant 13 and the filter 12, and flows into the airbag through the opening 9.

[0020]

The combustion vessel of the present invention, unlike a thin-walled canister vessel, does not require high dimensional accuracy, and therefore does not require expensive molds or advanced processing techniques. Therefore, it is easy to manufacture and requires much time and labor. Can be saved.

Further, since the present combustion container has sufficient strength, it is not damaged, and as a result, the moisture proof of the gas generating agent is ensured, and the normal operation of the airbag is always guaranteed. is there.

Further, since the present container is thick, the combustion of the gas generating agent can be controlled only by adjusting the diameter of the jet port.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a combustion vessel of the present invention.

FIG. 3 is a schematic partial sectional view showing another embodiment of the combustion vessel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diffuser shell 3 Closure shell 5 Combustion chamber 9 Opening 14 Combustion container 14a Bottom part 14b Inner cylinder part 14c Outer cylinder part 15 Gas generating agent 18 Central hole 21 Cover member 28 Opening 30 Seal tape 31 Spouting hole

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-289736 (JP, A) JP-A-2-24242 (JP, A) JP-A-4-266549 (JP, A) JP-A-4- 59451 (JP, A) JP-A-64-63437 (JP, A) JP-A-2-23314 (JP, U) JP-A-50-133779 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60R 21/16-21/32

Claims (1)

(57) [Claims] 1. A housing, a gas generator disposed in the housing, and an opening communicating the housing and the airbag, wherein gas generated by the gas generator by impact is introduced into the airbag. A gas generator for protecting an occupant from impact by impact, wherein the gas generator comprises a combustion vessel filled with a gas generating agent therein, the combustion vessel has a bottom having a central hole, and a central hole at the bottom. An inner cylindrical portion provided at a peripheral portion, an outer cylindrical portion provided at an outer peripheral portion of the bottom portion, and an annular combustion formed between the outer cylindrical portion and the inner cylindrical portion and containing a gas generating agent; And a lid member for sealing the combustion chamber, wherein the inner cylinder has an opening for introducing a flame of an ignition device into the combustion chamber, and the opening is a breakable seal member. And the outer cylinder portion is provided with a combustion gas for the gas generating agent. Have ejection holes for ejecting, 該噴 Deana, a gas generator for an air bag comprising a combustion vessel, characterized in that it is sealed by a breakable seal.