JP2000203372A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the thermal fusion of a filter member, and to improve the efficiency of the slug collection and the slug cooling, by distributing a high temperature gas generated at the initial period of the combustion, in the axial direction of the filter member, in a gas generator. SOLUTION: A gas generator carries out the slug collection and the cooling by burning a gas generating agent 4 from a lid member 7 side installing the ignitor 5 of a housing 1, and making a high temperature gas by the combustion flow in to a filter member 3. In the filter member 3, the lid member 7 side where the ignitor 5 is installed is made in the structure to pass less high temperature gas than the other parts up to the bottom 6c of an outer tube 6.

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 deploying an airbag for a passenger seat or a side collision of an automobile.

[0002]

2. Description of the Related Art A gas generator for instantaneously deploying an airbag for protecting an occupant from an impact caused by a collision of an automobile is incorporated in an airbag module mounted in an instrument panel or the like. This gas generator instantaneously generates a large amount of high-temperature gas based on a collision detection signal from a collision sensor in the event of a collision.

FIG. 7 shows a gas generator for deploying an airbag. This gas generator includes a long cylindrical housing 50 that forms a closed space S with an outer cylinder 51 and a lid member 52. A cylindrical filter member 53 and a gas generating agent 55 are sequentially housed in the housing 50 from the outer cylinder 51 toward the center of the shaft. An igniter 58 is attached to the lid member 52. The igniter 58 includes an igniter 56 ignited by a collision detection signal from a collision sensor, and a transfer agent 57 ignited by the ignition of the igniter 56. In this gas generator, the igniter 56 is ignited by a collision detection signal from a collision sensor, and this flame ignites the transfer agent 57. Then, the gas generator burns the gas generating agent 55 from the side of the lid member 52 with the flame of the transfer agent 57, and rapidly generates a large amount of high-temperature gas. A large amount of high-temperature gas generated in the housing 50 flows into the filter member 53, and is discharged through the gas discharge holes 51a of the outer cylinder 51 into the airbag through a process of collecting and cooling slag. The eBag is now deployed quickly.

[0004]

Conventionally, a metal filter member 53 has been used for gas generation. The metal filter member 53 is manufactured, for example, by winding a wire mesh or a metal fiber sheet or the like in a coil shape, or press-forming an aggregate including these into a cylindrical shape. The metal filter member 53 has a structure in which gas passing performance (porosity) is the same in the axial direction. Therefore, in the case where the gas generating agent 55 is burned from the side of the lid member 52 (one shaft end of the housing 50) in order to deploy the airbag, the high-temperature gas in the initial stage of combustion is directly in the filter member 53 on the side of the lid member 52. Will flow into When the high-temperature gas is concentrated on the igniter 58 side of the filter member 53, the heat of the high-temperature gas may melt a wire net or the like. As described above, when thermal damage occurs on the igniter 58 side of the filter member 53, high-temperature gas is more likely to flow in, and the efficiency of slag collection and cooling is reduced. Further, when the filter member 53 is damaged by heat, a large slag of particles generated in the early stage of combustion is discharged from the damaged portion to the outside of the housing, thereby damaging the airbag.

The present invention distributes high-temperature gas generated in the early stage of combustion in the axial direction of the filter member, thereby preventing thermal damage to the filter member and improving the efficiency of slag collection and cooling. The purpose is to provide a vessel.

[0006]

A gas generator according to the present invention (Claim 1) deploys an airbag for a passenger seat or a side collision, and a gas generating agent in a filter member by an igniter. Is what burns. In this gas generator, the filter members have different gas passage performances. The filter member has a structure through which gas easily passes and a structure through which gas does not easily pass. Then, a high temperature gas is generated by igniting the igniter and starting combustion from the gas generating agent in the filter member that does not easily pass the gas. The high-temperature gas generated in the filter member flows in from the structure side of the filter member through which gas hardly passes, and also flows in from the structure side through which the gas easily flows through the filter member. Thus, the high-temperature gas generated in the filter member can be distributed from the start of the combustion of the gas generating agent, so that it is possible to prevent the igniter from concentrating on the portion where the gas generating agent is burned. Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas.
Further, in the gas generator of the present invention, since the concentration of the high-temperature gas on the structure side of the filter member through which the gas does not easily pass can be eliminated, the thermal melting of the filter member in the early stage of the combustion of the gas generating agent can be prevented, and the particle generation can be prevented. Large slag can also be prevented from being discharged directly into the airbag. The airbag is now properly deployed by the large amount of clean gas released from the gas generator without being damaged by the hot slag.

A gas generator according to the present invention (Claim 2) is for deploying an airbag for a passenger seat or a side collision, and is provided in a filter member from a shaft end side of a housing in which an igniter is mounted. Of the gas generating agent. In this gas generator, the gas passage performance of the filter member is made different in the axial direction of the housing. The filter member has a structure in which the shaft end of the housing in which the igniter is mounted is less likely to allow gas to pass therethrough than the other portion reaching the other shaft end of the housing. And when you light the igniter,
Combustion of the gas generating agent in the filter member starts from the shaft end side of the housing in which the igniter is mounted, and generates high-temperature gas. The high-temperature gas generated in the filter member flows into the filter member from the shaft end side of the housing in which the igniter is mounted, and at the same time, flows from another portion through which the gas easily flows through the filter member. Become. Thereby, the high-temperature gas generated in the filter member can be distributed in the axial direction of the housing from the start of combustion of the gas generating agent, and can be prevented from being concentrated on the shaft end side of the housing in which the igniter is mounted. . Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas. Further, in the gas generator of the present invention, since the concentration of the high-temperature gas on the shaft end side of the housing in which the igniter is mounted can be eliminated, it is possible to prevent the heat melting of the filter member at the initial stage of combustion of the gas generating agent, Slags with large particles can also be prevented from being directly discharged into the airbag. Now the airbag is not damaged by the hot slag,
It is properly developed by the large amount of clean gas released from the gas generator.

A gas generator according to the present invention (claim 3) is for deploying an airbag for a passenger seat or a side collision, and is provided in a filter member from a shaft end side of a housing in which an igniter is mounted. Of the gas generating agent. In this gas generator, the gas passage performance of the filter member is made different in the axial direction of the housing. The filter member has a structure in which gas is less likely to pass through the shaft end of the housing on which the igniter is mounted than the other portion reaching the other shaft end of the housing, and the shaft end of the housing on which the igniter is mounted. The structure is such that the gas easily passes from the side toward the other shaft end. Then, when the igniter is ignited, combustion of the gas generating agent in the filter member is started from the shaft end side of the housing in which the igniter is mounted, thereby generating a high-temperature gas. The high-temperature gas generated in the filter member flows into the filter member from the shaft end side of the housing in which the igniter is mounted, and at the same time, flows from the filter member into another portion through which the gas easily passes. become. Thereby, the high-temperature gas generated in the filter member can be distributed in the axial direction of the housing from the start of combustion of the gas generating agent, and can be prevented from being concentrated on the shaft end side of the housing in which the igniter is mounted. . In addition, the filter member can further subdivide the gas passage performance in the axial direction of the filter member toward the other axial end of the housing, and can reliably distribute the high-temperature gas in the axial direction of the housing. It becomes possible. Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas.
Further, in the gas generator of the present invention, since the concentration of the high-temperature gas on the shaft end side of the housing in which the igniter is mounted can be eliminated, it is possible to prevent the heat melting of the filter member at the initial stage of combustion of the gas generating agent, Slags with large particles can also be prevented from being directly discharged into the airbag. The airbag is now properly deployed by the large amount of clean gas released from the gas generator without being damaged by the hot slag.

In the gas generator according to the present invention (claim 4), the filter member is constituted by a cylindrical filter unit divided into a plurality of parts. In this way, by preparing a plurality of filter units having different gas passage performances and connecting each filter unit between both shaft ends of the housing, it is possible to arrange the filter members corresponding to the length of the housing. it can.

A gas generator according to the present invention (Claim 5) is for deploying an airbag for a passenger seat or a side collision, wherein the gas generator is provided inside a filter member from a shaft end side of a housing in which an igniter is mounted. Of the gas generating agent. In this gas generator, the gas passage performance of the filter member differs in the axial direction of the housing due to the increase / decrease of the porosity formed by the components of the filter or the increase / decrease of the radial thickness due to the number of layers of the components of the filter. It was made. The filter member has a structure in which the shaft end of the housing on which the igniter is mounted is more difficult to pass gas than the other portion reaching the other shaft end of the housing, and has a shaft end side of the housing on which the igniter is mounted. From the shaft end to the other shaft end. Then, when the igniter is ignited, combustion of the gas generating agent inside the filter member is started from the shaft end side of the housing in which the igniter is mounted, thereby generating a high-temperature gas. The hot gas generated in the filter member is
At the same time, the gas flows into the filter member from the shaft end side of the housing in which the igniter is mounted, and at the same time, flows into the filter member from another portion through which the gas easily flows. Thereby, the high-temperature gas generated in the filter member can be distributed in the axial direction of the housing from the start of combustion of the gas generating agent, and can be prevented from being concentrated on the shaft end side of the housing in which the igniter is mounted. . In addition, the filter member can further subdivide the gas passage performance in the axial direction of the filter member toward the other axial end of the housing, and can reliably distribute the high-temperature gas in the axial direction of the housing. It becomes possible. Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas.
Further, in the gas generator of the present invention, since the concentration of the high-temperature gas on the shaft end side of the housing in which the igniter is mounted can be eliminated, it is possible to prevent the heat melting of the filter member at the initial stage of combustion of the gas generating agent, Slags with large particles can also be prevented from being directly discharged into the airbag. Further, the simple configuration of increasing or decreasing the porosity and the radial thickness by the components of the filter allows the shaft end side of the housing in which the igniter is mounted to have a strong structure. Thermal melting can be prevented. Now the airbag is not damaged by the hot slag,
It is properly developed by the large amount of clean gas released from the gas generator.

In the gas generator according to the present invention (claim 6), the filter member is constituted by a cylindrical filter unit divided into a plurality of parts. In this way, by preparing a plurality of filter units having different gas passage performances and connecting each filter unit between both shaft ends of the housing, it is possible to arrange the filter members corresponding to the length of the housing. it can.

A gas generator according to the present invention deploys an airbag for a passenger seat or a side collision, wherein the gas generator is provided in a filter member from a shaft end side of a housing in which an igniter is mounted. Of the gas generating agent. In this gas generator, the gas passage performance of the filter member differs in the axial direction of the housing due to the increase / decrease of the porosity formed by the components of the filter or the increase / decrease of the radial thickness due to the number of layers of the components of the filter. It was made. The filter member has a structure in which gas is less likely to pass through the shaft end side of the housing in which the igniter is mounted than the other portion reaching the other shaft end of the housing. Then, when the igniter is ignited, combustion of the gas generating agent in the filter member is started from the shaft end side of the housing in which the igniter is mounted, thereby generating a high-temperature gas. The high-temperature gas generated in the filter member flows into the filter member from the shaft end side of the housing in which the igniter is mounted, and at the same time, flows from the filter member into another portion through which the gas easily passes. become. Thereby, the high-temperature gas generated in the filter member can be distributed in the axial direction of the housing from the start of combustion of the gas generating agent, and can be prevented from being concentrated on the shaft end side of the housing in which the igniter is mounted. . Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas. Further, in the gas generator of the present invention, since the concentration of the high-temperature gas on the shaft end side of the housing in which the igniter is mounted can be eliminated, it is possible to prevent the heat melting of the filter member at the initial stage of combustion of the gas generating agent, Slags with large particles can also be prevented from being directly discharged into the airbag. Furthermore, the simple configuration of increasing or decreasing the porosity and the radial thickness by the components of the filter allows the shaft end side of the housing in which the igniter is mounted to have a strong structure, so that the filter member is made of a high-temperature gas. Thermal melting can be prevented. The airbag is now properly deployed by the large amount of clean gas released from the gas generator without being damaged by the hot slag.

In the gas generator according to the present invention (claim 8), the filter member is constituted by a cylindrical filter unit divided into a plurality of parts. In this way, by preparing a plurality of filter units having different gas passage performances and connecting each filter unit between both shaft ends of the housing, it is possible to arrange the filter members corresponding to the length of the housing. it can.

A gas generator according to the present invention is for deploying an airbag for a passenger seat or a side collision, and is provided in a filter member from a shaft end side of a housing in which an igniter is mounted. Of the gas generating agent. In this gas generator, the filter member is composed of a plurality of filter units. The filter knit has a structure in which the shaft end of the housing on which the igniter is mounted is more difficult to pass gas than other parts reaching the other shaft end of the housing. Then, when the igniter is ignited, combustion of the gas generating agent in the filter member is started from the shaft end side of the housing in which the igniter is mounted, thereby generating a high-temperature gas. The high-temperature gas generated in the filter member flows into the filter member from the shaft end side of the housing in which the igniter is mounted, and at the same time, flows from another portion through which the gas easily flows through the filter member. become. Thereby, the high-temperature gas generated in the filter member can be distributed in the axial direction of the housing from the start of combustion of the gas generating agent, and can be prevented from being concentrated on the shaft end side of the housing in which the igniter is mounted. . Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas. or,
In the gas generator of the present invention, since the concentration of the high-temperature gas on the shaft end side of the housing on which the igniter is mounted can be eliminated,
Thermal melting of the filter member in the early stage of combustion of the gas generating agent can be prevented, and slag containing large particles can also be prevented from being directly discharged into the airbag. The airbag is now properly deployed by the large amount of clean gas released from the gas generator without being damaged by the hot slag. Furthermore, in the gas generator of the present invention, a plurality of filter units having different gas passage performances are prepared, and each filter unit is connected between both shaft ends of the housing, so that the filter unit can be easily adapted to the length of the housing. A filter member can be arranged.

In the gas generator according to the present invention (claim 10), the gas discharge hole is formed in the axial direction including both shaft end portions of the housing in the gas generator of claims 1 to 9. This makes it possible to discharge the hot gas distributed in the axial direction of the housing by the filter member into the airbag over the axial direction of the housing.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas generator according to an embodiment of the present invention will be described with reference to the drawings.

The gas generator Y shown in FIG. 1 is for deploying an airbag for a passenger seat or a side collision. The gas generator Y includes a long cylindrical housing 1, an inner cylindrical member 2, a filter member 3, and a gas generating agent 4 disposed in a housing 1, and a gas generator Y on one axial end side of the housing 1. And an igniter 5 for burning the agent 4.

The housing 1 includes a long cylindrical outer cylinder 6 having one end opened and a bottom, and a lid member 7 for closing the opening of the outer cylinder 6.
It is composed of The housing 1 has a combustion space S formed therein by fitting the lid member 7 from the open end of the outer cylinder 6 and bending the caulking protrusion 6 b projecting in the axial direction from the open end of the outer cylinder 6 inward. It is structured to be.

On the inner periphery of the outer cylinder 6, there are formed a plurality of gas discharge holes 6a communicating from the combustion space S into an airbag (not shown). For example, as shown in FIG. 2, each of the gas discharge holes 6 a is formed at a position separated by an angle of 180 degrees in the circumferential direction of the housing 1. Each of these gas discharge holes 6a
Gas hole rows r1 to r3 and r4 to r6 formed at three locations in each of the above-described portions of the housing 1 are arranged. The gas discharge holes 6a of the respective gas hole rows r1 to r6 are
Are formed at predetermined intervals sequentially in the axial direction from the lid member 7 to the bottom 6c of the outer cylinder 6. In addition, each gas hole row r1
The gas release holes 6a to r6 are closed by band-shaped burst plates 8 attached to the inner periphery of the outer cylinder 6, respectively. The burst plate 8 is formed of a metal foil such as aluminum, and plays a role of preventing moisture in the combustion space S of the housing 1 and adjusting an internal pressure during combustion. Further, the burst plate 8 has a length and a width sufficient to close the gas discharge holes 6a for each of the gas hole rows r1 to r6. Note that it is not excluded that one burst plate 8 is adhered over the inner periphery of the outer cylinder 6.

In the combustion space S of the housing 1, an outer cylinder 6 is provided.
, The inner cylindrical member 2, the filter member 3, and the gas generating agent 4 are arranged in this order from the central axis toward the axis. The filter member 3 has a cushion member 17 for preventing the gas generating agent 4 from being powdered. The cushion member 17 is mounted on the inner periphery of the filter member 3 and is disposed on the bottom 6c of the outer cylinder 6.

The inner cylinder 2 is formed in a cylindrical shape. The inner cylindrical member 2 is formed by a reduced-diameter step 9 formed on the bottom 6 c of the outer cylinder 6.
And extends to the lid member 7 in the axial direction of the housing 1. Thus, the inner cylinder member 2 forms an annular gas passage space S1 with the inner periphery of the outer cylinder 6.
Further, the inner surface of the inner cylindrical member 2 and the gas passage space S1
Are formed, and a plurality of gas passage holes 2a are formed.
As shown in FIG. 2, the gas passage holes 2a are opened at predetermined intervals when viewed from the circumferential direction of the housing 1, and are formed in the axial direction of the housing 1.

The inner cylindrical member 2 can be manufactured by using an expanded metal shown in FIG. As shown in FIG. 4 (a), the expanded metal uniformly pulls the base material 10 having a large number of slits 10a formed at predetermined intervals to form a plurality of expanded metal pieces as shown in FIG. 4 (b). The gas passage hole 2a is opened. Then, as shown in FIG. 4 (c), the inner cylindrical member 2 is formed by molding an expanded body having a predetermined length and width into a cylindrical shape, and joining the ends to each other by a joining method such as spot welding. Produced in The base material 10 uses a stainless steel sheet excellent in heat resistance and pressure resistance, or a thin steel sheet other than stainless steel.

As shown in FIG. 5, when the inner cylindrical member 2 made of expanded metal is stretched in the direction of the arrow shown in FIG. From the flat portion B of the inner surface to the inner and outer peripheral sides by a height h. Therefore, each slit 1
Each of the gas passage holes 2a is formed so as to open in the circumferential direction of the housing 1 and extend in the axial direction by projecting toward the inner and outer circumferences at the portion 0a. Further, the inner cylindrical member 2 is provided with each slit 10
By projecting to the inner and outer peripheral sides at the portion a, each gas passage hole 2a has a structure communicating with each other in the circumferential direction of the inner cylindrical member 2.
The inner metal member 2 made of expanded metal is inserted into the housing 1 and protrudes to the inner and outer peripheral sides by the height h even when expanded and deformed by the high-temperature and high-pressure gas generated in the combustion space S. High-temperature and high-pressure gas can be passed from each gas passage hole 2a toward each gas discharge hole 6a.
Thus, even if the expanded metal inner cylinder member 2 is arranged so as to be in contact with the inner circumference of the outer cylinder 6, a continuous annular space can be formed on the inner circumference side of the outer cylinder 6. As the gas passage space S1.

The inner cylindrical member 2 is not limited to one made of expanded metal, but may be made of a porous thin steel plate. The porous thin steel plate is a punched metal plate having a plurality of gas passage holes 2a formed at predetermined intervals. The inner tubular member 2 is manufactured by forming a porous thin steel sheet into a cylindrical shape and then joining the ends to each other by a joining method such as spot welding. In the inner cylindrical member 2 made of a porous thin steel plate, it is necessary to provide an interval between the inner cylindrical member 2 and the inner periphery of the outer cylinder 6 so as to form the gas passage space S1.

The filter member 3 is composed of two cylindrical filter units 3A and 3B axially connected between both shaft ends of the housing 1 (between the bottom 6c of the outer cylinder 6 and the lid member 7). Have been. In addition, the filter member 3 is closely inserted into the inner cylinder 2 from the opening side (the lid member 7 side) of the outer cylinder 6. The filter unit 3 </ b> A is inserted into the reduced-diameter step portion 9 together with the inner cylindrical member 2, and is located on the bottom 6 c side of the outer cylinder 6. The filter unit 3B is located on the lid member 7 side continuously to the filter unit 3A. The filter member 3 has a structure in which the filter unit 3B has a structure that makes it difficult for high-temperature gas to pass through the filter unit 3A, thereby changing the gas passage performance in the axial direction of the housing 1. The gas generating agent 4 is disposed in the filter member 3. The gas generating agent 4 is loaded over the housing 1 in the axial direction.

The filter units 3A and 3B can be manufactured at a low cost by, for example, a knitted metal mesh shown in FIG. 6A or a crimp-woven metal wire shown in FIG. 6B. Each of the filter units 3A and 3B is manufactured by forming an aggregate of a knitted wire mesh or a crimp-woven metal wire into a cylindrical shape as shown in FIG. The filter unit 3B has a structure in which gas is harder to pass than the filter unit 3A due to a wire mesh or a metal wire as a component of the filter. Each filter unit 3
As a specific structure of A and 3B, the following can be adopted. First, each filter unit 3A,
3B with the same porosity δ, the filter unit 3
Filter unit 3 determines the number of layers of wire mesh or metal wire for B.
By setting the number to be larger than B, the thickness in the radial direction of the filter unit 3B is increased and the inner diameter is reduced. In addition, the porosity δ of the filter unit 3B is reduced by making the thicknesses of the filter units 3A and 3B in the radial direction the same and assembling the wire mesh and metal wire of the filter unit 3B more densely than the filter unit 3A. is there. Here, the porosity δ means a ratio of a void formed by a wire netting or a metal wire which is a constituent member of the filter.

The filter member 3 is formed by burning the gas generating agent 4 from one shaft end of the housing 1.
In addition to allowing the hot gas to flow into the filter unit 3B,
The high-temperature gas is also allowed to flow into the filter unit 3A, which is easier to pass than the filter unit 3B. Thus, the filter member 3 can distribute the high-temperature gas in the axial direction of the housing 1.

Further, as shown in FIGS. 1 and 3, in the gas generator Y employing the inner cylindrical member 2, each filter unit 3A,
As means for making the passing performance of 3B different, the inner cylindrical member 2 can be used. More specifically, the number of gas passage holes 2a in the inner cylindrical member 2 is reduced near the igniter 5 and gradually increased toward the other shaft end of the housing 1. Further, the diameter of the gas passage hole 2a of the inner cylinder 2 is
The structure is such that it decreases near the igniter 5 side and gradually increases toward the other shaft end of the housing 1. Further, the pitch of the gas passage holes 2a of the inner cylindrical member 2 is increased near the igniter 5 side, and is gradually reduced toward the other shaft end of the housing 1. As described above, by appropriately changing at least one of the number, the diameter, and the pitch of the gas passage holes 2a of the inner cylindrical member 2, each filter unit 3
The gas passage performance of the filter member 3 can be made different without changing the radial thickness and the porosity δ of A and 3B, and the structure has a structure in which high-temperature gas is easily passed and a structure in which high-temperature gas is not easily passed. The filter member 3 can be used.

The igniter 5 is ignited by a collision detection signal from a collision sensor (not shown).
And the transfer agent 12 ignited by the igniter 11.
The igniter 5 is mounted on a cover member 7 constituting one shaft end of the housing 1 and burns the gas generating agent 4 in the filter member 3 from the shaft end. The igniter 11 is caulked and fixed in a closed state in a storage hole 13 formed in the projection 7 a of the lid member 7. The storage hole 13 communicates with the inside of the filter member 3. Further, the transfer agent 12 is stored in a flanged cap 14. The flanged cap 14 is fitted into the projection 7a of the lid member 7 from inside the housing 1, and makes the transfer agent 12 face the projection 7a with a gap.

The projecting side 14a of the flanged cap 14 is inserted into the filter unit 3B of the filter member 3. The propellant 12 is provided on the projecting side 14a of the cap 14.
Has a through-hole 14b for injecting the flame into the filter member 3. The flange 14c of the cap 14 is interposed between the filter unit 3B and the lid member 7. The flange 14c of the cap 14 extends to the inner circumference of the outer cylinder 6, and is sandwiched by the lid member 7, the filter unit 3B, and the inner cylinder 2. Further, the collar 14 of the cap 14
c is resiliently contacted with an annular seal member 15 for closing the lid member 7 side of the filter unit 3B and a seal ring 16 interposed in the lid member 7 to seal the combustion space S of the housing 1 from the outside. ing.

Next, the operation of the gas generator Y will be described.

When the collision sensor detects a vehicle collision,
By igniting the igniter 11 of the igniter 5, the transfer agent 12 is ignited. The ignition flame of the transfer agent 12 passes through the through-hole 14b of the cap 14 to the filter unit 3 of the filter member 3.
The gas is ejected into B, and the flame is used to burn the gas generating agent 4 from the lid member 7 side (one shaft end side of the housing 1), thereby generating a high-temperature gas.

The high-temperature gas in the initial stage of combustion burns the gas generating agent 4 by the flame of the transfer agent 12 (hereinafter, referred to as a portion).
Directly from the “burning part”)
Will flow in. However, the filter unit 3B has a structure in which gas is more difficult to pass than the filter unit 3A reaching the other shaft end of the housing 1.
Therefore, most of the high-temperature gas cannot flow into the filter unit 3B from the combustion portion, and flows toward the bottom 6c of the outer cylinder 6, which is the other shaft end of the housing 1. Then, the high-temperature gas is sequentially supplied to the outer cylinder 6.
While flowing to the bottom 6c side, the high-temperature gas that flows into the filter unit 3B from a portion other than the above-described combustion portion, and that cannot be flown here, flows into the filter unit 3A.
This is because the filter member 3 has a structure in which the gas passage performance is changed in the axial direction of the housing 1 so that the filter unit 3B has a structure in which gas is less likely to pass than the filter unit 3A. That is, by making the filter unit 3B a structure that is more difficult to pass gas than the filter unit 3A, a high-temperature gas that cannot flow into the filter unit 3B is guided to the filter unit 3A that allows gas to pass easily.
This is because it can flow into the filter unit 3A.

As a result, the high-temperature gas in the initial stage of combustion is distributed over the axial direction of the filter member 3 without concentrating on the combustion portion. Therefore, the entire area of the filter member 3 is utilized, and slag collection and cooling of the high-temperature gas can be reliably performed. In addition, since the high-temperature gas does not concentrate on the combustion portion, it is possible to prevent the filter (wire mesh or metal wire) from melting due to combustion. As a result, slag of large particles generated in the early stage of combustion is collected by the filter member 3 and is not discharged to the outside of the housing 1 and does not cause thermal damage to the airbag. Further, the filter unit 3B can have a sturdy structure by increasing the thickness in the radial direction or reducing the porosity δ, and can prevent thermal melting by high-temperature gas.

The high-temperature gas flowing into each of the filter units 3A and 3B passes through slag collection and cooling, where
Out of each gas passage hole 2a into the gas passage space S1. Then, the combustion of the gas generating agent 4 proceeds, and the housing 1
When the pressure in the combustion space S reaches a predetermined pressure, the burst plate 8 bursts. The gas cleaned by each of the filter units 3A and 3B is discharged into the airbag from each of the gas discharge holes 6a, and rapidly inflates and deploys the airbag.

At this time, the high-temperature gas generated in the housing 1 is distributed in the axial direction of the housing 1 (the filter member 3), so that the clean gas discharged from each gas discharge hole 6a is made uniform. Will be. The airbag is smoothly and evenly deployed by the clean gas uniformly discharged from the housing 1 in the axial direction.

As described above, in the gas generator Y of the present invention,
The high temperature gas in the early stage of combustion is distributed in the axial direction of the filter member 3 (the filter units 3A and 3B), so that it is possible to prevent the high temperature gas from being concentrated on the combustion portion. Therefore, the entire area of the filter member 3 can be effectively used, and the efficiency of collecting and cooling the slag of the high-temperature gas can be improved.

Further, since the high-temperature gas does not concentrate on the combustion portion of the filter unit 3B, it is possible to prevent the filter (wire mesh or metal wire) from being thermally melted at the combustion portion. Therefore, it is also possible to prevent slag having large particles from being directly discharged into the airbag.

Further, since the high-temperature gas is distributed in the axial direction of the filter member 3, clean gas can be uniformly discharged from each gas discharge hole 6a formed in the axial direction of the housing 1. Thus, the airbag can be smoothly deployed without bias.

When each gas discharge hole 6a is formed in the axial direction of the housing 1, high-temperature gas is
It is possible to flow in the entirety, and the efficiency of slag collection and cooling of high-temperature gas can be improved.

In the gas generator Y shown in FIGS. 1 and 2, a structure in which the filter member 3 is divided into two filter units 3A and 3B and connected in the axial direction of the housing 1 has been described. , The filter member 3 may be divided into three filter units 3A, 3B and 3C. In the gas generator Y of FIG. 3, the filter unit 3B on the lid member 7 has a structure that makes it difficult for gas to pass therethrough, and the intermediate filter unit 3C and the structure that makes it easy for gas to pass therethrough toward the filter unit 3A on the bottom 6c of the outer cylinder 6. I do.
As described above, the structure of each of the filter units 3A to 3C increases or decreases the radial thickness or increases or decreases the porosity δ. Thus, the filter member 3 can achieve finer gas passage performance in the axial direction, and can reliably distribute the high-temperature gas in the axial direction of the housing 1. Although the case where the filter member 3 is divided into two or three has been described above, the filter member 3 may be divided into four or more or innumerable stages.

The filter member 3 is not limited to the one composed of a plurality of divided filter units 3A and 3B. The filter member 3 is integrally formed by press-forming so as to change the thickness and the porosity δ of a layer of a wire mesh or a metal wire as a constituent member of the filter in the axial direction, or by winding it into a coil shape. May be used. in this case,
The filter member 3 has a structure that makes it difficult for gas to pass through on the side of the lid member 7, and gradually allows gas to pass therethrough toward the bottom 6 c of the outer cylinder 6. Thus, the filter member 3 can achieve finer gas passage performance in the axial direction, and can reliably distribute the high-temperature gas in the axial direction of the housing 1.

The filter member 3 (filter unit 3A,
3B) is a metal fiber sheet, a combination of a metal mesh and a metal fiber sheet, which is press-formed into a cylindrical shape, or a metal mesh, a metal fiber sheet and a nonmetal The combination of the fiber sheets may be press-formed into a cylindrical shape, or may be wound into a coil and formed into a cylindrical shape. Further, as the filter member 3 (filter units 3A and 3B), a plurality of wire mesh layers are laminated,
By compressing the laminated wire netting while heating and softening it, a sintered body in which wires are mainly entangled may be formed into a sintered body. Further, the filter member 3 (the filter units 3A and 3B) may be formed by winding the expanded metal shown in FIGS. 4 and 5.

The housing 1 has a long cylindrical outer cylinder 6 with one end opened and a bottom, and a lid member 7 for closing the opening of the outer cylinder 6. However, the present invention is not limited to this. It is not something to be done. The housing may have a structure in which a combustion space is formed inside by a long cylindrical outer cylinder having both ends opened and two lid members closing both ends of the outer cylinder 6.
In this case, each lid member is fixed by caulking to the outer cylinder, or each lid member and the outer cylinder are joined by friction welding.

Further, in the gas generator Y of the present invention, the structure in which the gas generating agent 4 in the filter member 3 is burned by one igniter 5 has been described, but the present invention is not limited to this. A device corresponding to soft inflation technology that enables control of inflation and deployment of an airbag by attaching a container to each shaft end of the housing may be used. The gas generator corresponding to this soft inflation technology ignites the two igniters with a small time difference according to the collision mode of the vehicle, so that the airbag is gradually inflated and deployed with a small amount of gas in the initial stage of deployment, After a time difference, a large amount of gas causes rapid expansion and development. Then, the structure of the filter member 3 is such that it is difficult for gas to pass through each shaft end of the housing in which each igniter is mounted, and gradually from each shaft end to the center of the housing 1 in the axial direction. The structure is such that gas can easily pass through. with this,
High temperature gas does not concentrate near each igniter, and the entire filter member can be used efficiently.

Further, the filter member 3 is not limited to a structure in which the shaft end of the housing 1 has a structure through which gas hardly passes. In short, the structure of the filter member 3 may be such that the portion in which the gas generating agent 4 combusted by the igniter 5 is loaded has a structure that makes it difficult for gas to pass therethrough. The structure and the structure through which gas can easily pass are appropriately changed.

[0047]

According to the gas generator of the present invention, the high temperature gas generated in the filter member can be distributed from the start of the combustion of the gas generating agent, and the high temperature gas can be concentrated on the portion where the gas generating agent is burned by the igniter. Can be prevented. Therefore, in the gas generator of the present invention, it is possible to effectively utilize the entire filter member and increase the efficiency of collecting and cooling the slag of the high-temperature gas.

Further, in the gas generator according to the present invention, since the concentration of the high-temperature gas on the structure side of the filter member through which the gas does not easily pass can be eliminated, the thermal melting of the filter member at the initial stage of combustion of the gas generating agent can be prevented. In addition, it is possible to prevent slag having large particles from being directly discharged into the airbag. The airbag is now properly deployed by the large amount of clean gas released from the gas generator without being damaged by the hot slag.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

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

FIG. 4 is a view showing a member for forming the inner cylindrical member,
(A) is a diagram showing an expanded metal base material,
(B) is a figure which shows the state which pulled the base material, (c) is a perspective view which shows the inner cylinder material shape | molded by the expanded metal.

FIG. 5 is a sectional view showing a tension state of the expanded metal shown in FIG. 4;

6A and 6B are diagrams showing members for forming a filter member, wherein FIG. 6A is an enlarged view showing a knitted wire mesh, FIG. 6B is an enlarged view showing a crimp-woven metal wire, and FIG. 6C is a formed filter It is a perspective view which shows a member.

FIG. 7 is a cross-sectional view showing a conventional gas generator used for a passenger seat and a side collision airbag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inner cylinder material 3 Filter member 3A-3C filter unit 4 Gas generating agent 5 Ignition device 6 Outer cylinder 6a Gas discharge hole 7 Lid member

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenji Sako 3903-39, Tomicho, Himeji-shi, Hyogo Prefecture Inside the Nippon Kayaku Co., Ltd. Nippon Kayaku Co., Ltd. Himeji Factory

Claims (10)

[Claims] 1. A cylindrical filter member disposed in a long cylindrical housing having a plurality of gas discharge holes, a gas generating agent loaded in the filter member and generating a high-temperature gas by combustion; An igniter mounted on the housing and burning the gas generating agent in the filter member, wherein the filter member has a structure through which the high-temperature gas can easily pass;
A structure through which the high-temperature gas is difficult to pass. 2. A cylindrical filter member disposed between both axial ends of a long cylindrical housing having a plurality of gas discharge holes, and a cylindrical filter member filled in the filter member, and A gas generator comprising: a gas generating agent for generating a high-temperature gas; and an igniter mounted on one shaft end of the housing and burning the gas generating agent in the filter member from the shaft end side. A gas characterized in that the filter member has a structure in which the high-temperature gas is harder to pass on the shaft end side of the housing in which the igniter is mounted than the other portion reaching the other shaft end of the housing. Generator. 3. A cylindrical filter member disposed between two axial ends of a long cylindrical housing having a plurality of gas discharge holes, and a cylindrical filter member filled in the filter member, and A gas generator comprising: a gas generating agent for generating a high-temperature gas; and an igniter mounted on one shaft end of the housing and burning the gas generating agent in the filter member from the shaft end side. The filter member has a structure in which the high-temperature gas is less likely to pass through the shaft end portion side of the housing on which the igniter is mounted than the other portion reaching the other shaft end portion of the housing. A gas generator having a structure in which the high-temperature gas easily passes from the shaft end of the mounted housing toward the other shaft end. 4. The filter member according to claim 3, wherein the filter member comprises a plurality of divided cylindrical filter units, and each of the filter units is provided continuously between both shaft ends of the housing. A gas generator according to claim 1. 5. A cylindrical filter member disposed between two axial ends of a long cylindrical housing having a plurality of gas discharge holes, and a cylindrical filter member which is filled in the filter member and is burned. A gas generator comprising: a gas generating agent for generating a high-temperature gas; and an igniter mounted on one shaft end of the housing and burning the gas generating agent in the filter member from the shaft end side. The filter member increases or decreases the porosity formed by the components of the filter, or increases or decreases the thickness in the radial direction according to the number of layers of the components of the filter, so that the high-temperature gas passage performance in the axial direction of the housing. The shaft end side of the housing in which the igniter is mounted is formed differently from
The other part reaching the other shaft end of the housing has a structure in which the high-temperature gas does not easily pass therethrough, and the housing is further equipped with the igniter from the shaft end side toward the other shaft end. A gas generator characterized by a structure that allows high-temperature gas to pass easily. 6. The filter member according to claim 5, wherein the filter member comprises a plurality of divided cylindrical filter units, and each of the filter units is provided continuously between both shaft ends of the housing. A gas generator according to claim 1. 7. A cylindrical filter member disposed between two axial ends of a long cylindrical housing having a plurality of gas discharge holes, and a cylindrical filter member filled in the filter member, and A gas generator comprising: a gas generating agent for generating a high-temperature gas; and an igniter mounted on one shaft end of the housing and burning the gas generating agent in the filter member from the shaft end side. The filter member increases or decreases the porosity formed by the components of the filter, or increases or decreases the thickness in the radial direction according to the number of layers of the components of the filter, so that the high-temperature gas passage performance in the axial direction of the housing. The shaft end side of the housing in which the igniter is mounted is formed differently from
A gas generator having a structure in which the high-temperature gas is harder to pass than another portion reaching the other shaft end of the housing. 8. The filter member according to claim 7, wherein the filter member comprises a plurality of divided cylindrical filter units, and each of the filter units is provided continuously between both shaft ends of the housing. A gas generator according to claim 1. 9. A cylindrical filter member disposed between two axial ends of a long cylindrical housing having a plurality of gas discharge holes, and a cylindrical filter member filled in the filter member, and A gas generator comprising: a gas generating agent for generating a high-temperature gas; and an igniter mounted on one shaft end of the housing and burning the gas generating agent in the filter member from the shaft end side. The filter member is composed of a plurality of filter units continuously provided between both shaft ends of the housing, and a shaft end side of the housing on which the igniter is mounted,
A gas generator having a structure in which the high-temperature gas is harder to pass than another portion of the housing toward the other shaft end. 10. The gas generator according to claim 1, wherein each of the gas discharge holes is formed in an axial direction including both ends of the housing.