JPH07164998A - Gas generator and air bag module - Google Patents

Abstract

PURPOSE:To provide a gas generator and an air bag module, which are constituted to reduce size, weight, and a cost, by using a gas generating agent prevented from generating slug. CONSTITUTION:A gas generator 2 comprises a base member 3a; a gas generating agent container 6 disposed at the central part of a base member 3a and containing a gas generating agent to form a combustion chamber; an ignition member 9 contained in the container 6 and mounted on a base 3a; and a bag support tool 11 which is arranged on the base member 3a in a state to surround the upper surface and the side of the gas generating agent container 6 with a gap therebetween and in which a gas hole 11a running to an air bag 5 is formed. An air bag module 1 comprises the gas generator 2; an air bag 5 folded in a state to cover the upper surface and the side of the bag support tool 11 and supported to the base member 3a; and a developable bag cover 4 with which the air bag 5 is covered. The bag cover 4 is coupled directly or indirectly to the base member 3a.

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 inflating an airbag as a vehicle occupant protection device and an airbag module using the gas generator.

[0002]

BACKGROUND OF THE INVENTION Air bag modules are used to protect occupants from shocks that occur during a vehicle collision.
Attached to the steering wheel or instrument panel, the gas supplied from the gas generator at the time of collision causes the airbag to inflate and inflate like a balloon, and serves as a cushioning material between the steering wheel and the occupant to protect the occupant. Is. Further, conventionally, an azide-based chemical has been mainly used as a gas generating agent of a gas generator used in an airbag module of this type.

[0003]

By the way, the above-mentioned azide chemical contains sodium, and produces a combustion gas by a chemical reaction and produces a high temperature slag (residue). Therefore, the gas generator has a gas filter for removing slag, and a coolant for maintaining the gas passing through the gas filter at proper pressure-time characteristics and temperature (may also be used as a gas filter). It was necessary to provide a filter cover or the like for holding the gas filter or the coolant and preventing the slag from flowing out from the end.

Further, since the azide-based drug has a property that it is extremely toxic when it absorbs moisture and generates explosive hydrazoic acid, it is necessary to provide a hermetically sealed container for hermetically containing the gas generating agent. Furthermore, this hermetically sealed container also had to have a gas pressure adjusting function in order to obtain an appropriate gas pressure in the initial stage of the reaction.

Such a gas generator has a chamber for accommodating a hermetically-sealed container for a gas generating agent and a chamber for accommodating a filter through which combustion gas passes through a complicated path in the axial and radial directions. The short cylindrical containers were arranged in a staggered manner, and had a structure in which combustion gas was emitted from the side surface of the container. Further, since it is necessary to withstand pressure, the container had a structure in which a sturdy upper container and lower container were friction-welded or fixed with screws.

Therefore, a gas generator having a pressure resistant structure in which a coolant and a filter are arranged intricately inevitably has a large number of parts, a large capacity, a heavy weight, and a high cost. Further, an airbag module using such a gas generator also causes an increase in size, weight and cost.

The present invention has been made in view of such problems of the prior art, and its object is to use a gas generating agent that does not generate slag. Another object of the present invention is to provide a gas generator and an air bag module that are reduced in size, weight, and cost.

[0008]

A gas generator of the present invention for solving the above-mentioned problems includes a base member, and a gas generant container which is provided in the center of the base member and which stores a gas generant and serves as a combustion chamber. A gas hole extending to the airbag is provided in the base member so as to surround an ignition member provided in the container and attached to the base and an upper surface and a side surface of the gas generant container with a gap. It comprises a bag support.

The airbag module includes the gas generator, an airbag folded to cover the upper surface and the side surface of the back support and supported by the base member, and a deployable bag that covers the airbag. And a back cover, which is directly or indirectly connected to the base member.

[0010]

[Function] A gas generating agent that does not contain sodium azide and uses triaminoguanidine / nitrate alone or as a main material becomes carbon dioxide / nitrogen gas / vapor when burned, does not generate high-temperature slag, and has hygroscopicity. Absent. Therefore, the function required for the gas generant container is that the gas generant does not scatter at the time of combustion and maintains an appropriate pressure that is not high pressure, and has a structure that maintains air permeability, an inorganic / organic material, Various materials such as carbon and vegetable fiber can be used. The combustion gas discharged from the side surface and the upper surface of the gas generating agent container passes through a gap between the gas generating agent container and the bag supporting tool, and is cooled by a cooling member as necessary, and the side surface of the bag supporting tool. The combustion gas is discharged toward the air bag from only the upper surface or the side surface and the upper surface only.

Such a gas generator is not particularly required to have a pressure resistant structure, and a simple structure in which the gas generating agent container and the back support is placed on the base member is sufficient, and the airbag is mounted on the base member. The bag cover has a simple structure that directly or indirectly connects to the base member.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional view of a gas generator and an airbag module of the present invention, FIG. 2 is a view taken in the direction of arrow A in FIG. 1, and FIG. 3 is a view taken in the direction of arrow B in FIG.

First, the structure will be described with reference to FIGS. In FIG. 1, an airbag module 1 includes a gas generator 2, an airbag 5 folded and arranged outside the gas generator 2, and a box attached to an extension portion of a base member 3 a of the gas generator 2. The gas generator 2 is formed in the air bag component housing chamber (space) 17 formed between the base member 3 and the bag cover 4 and is formed by the bag-shaped bag cover 4.
And the airbag 5.

The gas generator 2 is provided on the base member 3 and accommodates the gas generating agent 10 and serves as a combustion chamber for the gas generating agent 10.
The gas generating agent 10 is arranged in the central portion of the gas generating agent container 6
An ignition member 9 for igniting a gas, a cylindrical bag support 11 provided between the gas generant container 6 and the airbag 4 and having a gas release hole 11a, the bag support 11 and the gas generant container 6. And a gas coolant 19 disposed between the two.

When the gas generator 2 is viewed from another angle, a combustion chamber 25 is housed so that the gas generating agent does not scatter, and an ignition member is also incorporated, and a gap is formed between the upper surface and the side surface of the combustion chamber 25. The combustion gas passage chamber 26 has two chambers 25 and 26 which are formed so as to surround the combustion gas passage chamber 26. It is also the one that was made to squirt.

The base member 3 has a disk-shaped base 3a as a basic member as shown in FIG. 3, but in order to mount the back cover 4, a box-shaped bent flange 3b is mounted by a bolt 13, Further, the plate-like engaging member 3c is attached to the flange 3b with a rivet 16. The bag cover 4 is attached to the tip of the engaging member 3c.
The groove portion 4b provided at the tip of is engaged. In FIG. 2, an H-shaped fragile portion 4 is formed inside the bottom surface of the bag cover 4.
a is provided so that the airbag 5 can be torn and deployed when inflated. Returning to FIG. 1, therefore, when the airbag 5 inflates, the bag cover 5 breaks from the fragile portion 4a and expands upward in the drawing, so that the airbag 5 can be inflated.

The base portion of the gas generating agent container 6 is fixed to the base 3a by the screw 14, the base portion of the bag support 11 is welded 15 and the like, and the end portion of the airbag 5 is fixed to the base 3a by the pressing plate 18 and the bolt 13. . Thus, common base 3
When the components 6, 11 and 5 are attached to a, in particular, only the base 3a is required as a component requiring strength, and the structure is simplified. Of course, for example, the airbag 5 may be attached to the bag support 11, and the bag support 11 may be attached to the gas generating agent container 6.

As the gas generating agent 10, a new one which does not generate slag due to reaction (combustion) and has no hygroscopic property has been developed and is used. For example, Japanese Patent Laid-Open No. 5-
As disclosed in Japanese Patent No. 254977, there is used one which does not contain sodium azide and which uses triaminoguanidine / nitrate alone or as a main material. Combustion gas is carbon dioxide
It is nitrogen gas / steam, and does not generate slag that must be removed.

The ignition member 9 comprises a squib 8 and a transfer charge 7 arranged in contact with the squib 8, and the squib 7 is provided with a lead wire 1.
2 is connected to a power source (not shown). By disposing the transfer charge 7 in this way, the gas generating agent 10 can be reacted uniformly, but it may be omitted for simplification.

The gas generating agent container 6 is constructed so that the gas generating agent 10 does not scatter from the inside of the container 6 during reaction and restrains the combustion gas at an appropriate pressure, so that at least a part of the wall surface has air permeability. Composed. For example, as the wall surface material, a relatively thin metal plate in which gas holes 6a are appropriately provided on the upper surface and the side surface is used, and the pressure can be restricted by the opening ratio of the gas holes. Further, when the wall material is, for example, a metal / inorganic / organic material net having a structure that maintains air permeability, or a carbon / vegetable fiber material cloth, it is not necessary to provide a special gas hole 6a, and the structure is simplified. can do.

The coolant 19 is made of metal such as wire mesh, inorganic fiber, heat-soluble polymer material, water or water-containing substance, and these materials are used as the gas generating material container 6 and the bag support 11 described above. And is filled in the container either directly or in a container, and the gas is arranged so that the gas can pass therethrough while contacting.
With this coolant 19, the temperature and pressure-time characteristics of the gas generated in the gas generating agent container 6 can be adjusted appropriately. The coolant 19 is not an essential requirement of the present invention, and can be omitted if it is simplified depending on the combustion characteristics of the gas generating agent.

Next, the operation of the above-described gas generator and airbag module will be described. In FIG. 1, when a vehicle collision is detected by a collision sensor (not shown), the squib 8 is electrically heated and ignited to ignite the transfer charge 7, and the ignition of the transfer charge 7 causes the gas generating agent 10 to react with a large amount. Generates gas. The generated gas flows from the gas holes 6a of the gas generating agent container 6 to the surroundings, passes through the coolant 19, and is cooled to an appropriate temperature. From the gas holes 11a of the bag support tool 11, the side surface and the upper surface, or only three sides, It flows only to the top surface. As a result, the airbag 5 inflates, the fragile portion 4a of the bag cover 4 cracks and opens upward in the drawing, and the airbag 5 bulges in the direction of the arrow 20 and deploys. That is, the combustion gas can be radially released to only the top surface and the side surfaces, or only the top surface and the side surfaces, and the airbag 5 can be inflated in the most natural form.

The fragile portion 4a can be set so that it breaks when the pressure inside the airbag reaches a predetermined value, if necessary. In this way, the gas generant container 6
The internal pressure can be maintained above a certain level at the initial stage of the reaction of the gas generant 10, and the reaction can be promoted. Alternatively, bag tightening means may be provided that allows the inflation of the airbag when the pressure in the airbag reaches a predetermined value. For example, it can be an aluminum foil.

Although the above-described embodiment has described the case where the gas generator 2 is used as a part of the airbag module, the gas generator 2 in FIG. It can be applied to a module, and in that case, the same effect as the above case can be obtained.

[0025]

As described above, the gas generator and the air bag module of the present invention are basically the same as the gas generator according to the use of the gas generating agent that does not generate high temperature slag and does not have hygroscopicity. Since it consists of a gas generant container that doubles as a storage chamber for the gas generant and a combustion chamber, a simple bag support that replaces the conventional pressure-resistant housing, etc., components such as a gas generant sealed container and a gas filter are omitted. The overall structure is simple. As a result, it is possible to reduce the size and weight of the gas generator and the air bag module and reduce the cost.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas generator and an airbag module of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is a view on arrow B of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air bag module 2 Gas generating means 3, 3a Base member 4 Bag cover 5 Air bag 6 Gas generating agent container 7 Transfer agent 8 Squib 9 Ignition member 10 Gas generating agent 11 Bag support 11a Gas hole 17 Air bag component accommodating chamber (Space) 19 Gas coolant 25 Combustion chamber 26 Combustion gas passage chamber

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Morio Kitao 3903-39, Abundant Town, Himeji City, Hyogo Prefecture Nihon Kayaku Co., Ltd. Himeji Factory (72) Inventor Hidefumi Sato 3903-39 Abundant Town, Himeji City, Hyogo Prefecture Nippon Kayaku Co., Ltd. Himeji Factory

Claims (6)

[Claims] 1. A combustion chamber which is housed so as not to scatter a gas generating agent and also has a built-in ignition member, and a combustion gas passage chamber which is formed so as to surround the combustion chamber with a gap between the upper surface and the side surface. A gas generator configured to eject the combustion gas toward the airbag from the upper surface and the side surface of the combustion gas passage chamber or from only the upper surface and the side surface of the combustion gas passage chamber. 2. The gas generator according to claim 1, wherein the gas generating agent does not contain sodium azide and triaminoguanidine / nitrate is used alone or as a main material. 3. A base member, a gas generating agent container which is provided in the center of the base member and serves as a combustion chamber for accommodating a gas generating agent, and an ignition member which is provided in the container and is attached to the base. A gas generator comprising: a bag support member provided in the base member so as to surround an upper surface and a side surface of the gas generant container with a gap, and a gas hole reaching an airbag is opened. 4. The gas generator according to claim 2, wherein an upper surface and a side surface of the gas generating agent container are made of a material having air permeability. 5. A combustion gas cooling member is arranged in a gap between the gas generating agent container and the bag support.
The gas generator described. 6. The gas generator according to claim 2, an airbag which is folded to cover an upper surface and a side surface of the back support and is supported by the base member, and a deployable bag cover which covers the airbag. An airbag module comprising: a back cover directly or indirectly connected to the base member.