JPH10324217A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize and lighten a longer and tubular gas generator used in an air bag at lower cost, by placing a mesh member between a housing and a filter and forming an annular gas passing space between the housing and the filter. SOLUTION: A housing 1 of a gas generator X consists of a bottom-existing tubular outer cylinder 5 which is longer and opened at its one end and a covering member 6 which covers the opening end, and a sealed space is formed by butting and friction-welding an annular rib 6a which is formed at the outer peripheral edge of the covering member 6 and the opening end of the outer cylinder 5. A filter 3 and a mesh member 13 are sequentially arranged outward from the axis center in the housing 1, the gas passing space G is formed between an inner peripheral surface of the outer casing 5 and an outer peripheral surface of the filter 3 with the mesh member 13, and a gas generating agent 2 is packed in the filter 3. A cushion material 15 against the gas generating agent 2 and filter 3 is arranged on the bottom of the outer cylinder 5.

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, and more particularly, to a long cylindrical gas generator for a passenger seat or a side collision.

[0002]

2. Description of the Related Art A typical example of a long cylindrical gas generator used in a conventional passenger or side collision airbag will be described with reference to FIG. 6, a gas generator has an outer cylinder 101 having a plurality of gas discharge holes 101a on an outer peripheral surface and having a bottomed cylindrical body having one end opened, and an outer cylinder 10 having the same shape.
1 has a long cylindrical housing 100 in which a closed space is defined by a lid member 102 closing an open end, and a cylindrical burst plate 1 for closing each gas discharge hole 101a.
03 is inserted into the inner peripheral surface of the outer cylinder 101, and a cylindrical filter 104 is inserted so as to be in close contact with the inner peripheral surface. Further, inside the housing 101, a gas generating agent 105, an inner cylinder 106 having a plurality of gas passage holes 106, and the filter 104 are housed from the axial center thereof. An ignition device 109 including an ignition device 107 ignited by a collision detection signal of a collision sensor and a transfer agent 108 ignited by the ignition device 107 is disposed on the lid member 102.

[0003]

By the way, the application range of the airbag for the passenger seat or the side collision has been expanded to various types of vehicles in recent years. In particular, the gas generator for the side collision has a seat back. Due to the necessity of installation in a narrow space such as a side portion or a vehicle body pillar portion, reduction in size and weight is required.
Further, in the gas generator for the passenger seat, further reduction in size and weight is desired in order to mount the gas generator in a narrow instrument panel.

[0004] However, in the conventional gas generator, the housing 100 (the outer cylinder 10) is required to cope with miniaturization and weight reduction.
If 1) is reduced in diameter, it is necessary to reduce the diameter of the inner cylinder 106 accordingly. However, the reduction in the diameter of the inner cylinder 106 is accompanied by difficulties in molding and increases the molding cost.
Further, when the diameter of the housing 100 is reduced, each gas discharge hole 1
01a to the outer cylinder 101
The work of sticking on the entire inner circumference of the device becomes complicated. Therefore, simply reducing the diameter of the housing 100 may cause an increase in the manufacturing cost of the gas generator due to the difficulty in forming the inner cylinder 106 and the complicated work of attaching the burst plate 103.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and it is possible to reduce the size and weight of an elongated cylindrical gas generator used for a passenger seat or side collision airbag at a low cost and at a low cost. It is designed to be easily performed.

[0006]

In order to solve the above-mentioned problems, in the gas generator of the present invention, a gas generating agent, a filter, and each gas discharging hole are placed in a housing having a plurality of gas discharging holes from the center of the housing. Burst plates to be closed are sequentially arranged, and in a gas generator equipped with an igniter for burning a gas generating agent at an end, a mesh member is arranged between the housing and the filter. An annular gas passage space is formed between the housing and the filter.

Thus, the mesh member having the function of the conventional inner cylinder, which defines the gas passage space and allows the gas from the filter to flow into the gas passage space, is arranged closest to the housing. Even if the size of the housing is reduced, the mesh member can be enlarged to a size close to the inner diameter of the housing. Further, since the gas pressure is equalized by the gas passage space defined between the housing and the filter, the gas can be uniformly discharged from the gas discharge holes.

Further, it is preferable to use a mesh member in which a metal mesh is formed in a cylindrical body and wave-shaped peaks and valleys are formed over the peripheral surface. Thus, by simply inserting the mesh member into the housing, a gas passing space can be easily defined between the housing and the filter at the wavy crests or valleys. It can be easily held at the peaks or valleys projecting inside the member.

Further, when a filter is constructed by laminating filter units, it is possible to easily and inexpensively cope with a long gas generator simply by laminating a plurality of filter units. As an example of such a filter unit, a knitted wire mesh or a crimped wire material obtained by press molding is preferable from the viewpoint of cost reduction. Also, by disposing the lamination boundary surface of each filter unit so as to be shifted from the position of each hole of each cylinder,
Even if a plurality of filter units are stacked to form a filter, gas does not leak directly to the outside (airbag) through the stacking boundary surface of each filter unit.
After the slag or the like is removed by colliding with the inner peripheral surface of the housing, the gas can be discharged to the outside from each gas discharge hole.

In addition, it is preferable that a sealing material for blocking the flow of the high-temperature gas between the filter units is interposed at the lamination boundary surface of each filter unit. Since the axial flow between the gases passing through the filter units is blocked by the seal material, each filter unit can be effectively used in the axial direction, and the slag contained in the gas can be reliably captured and cooled. Will be.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas generator according to an embodiment of the present invention will be described below with reference to FIGS. First, FIG. 1 shows a cross-sectional view of a gas generator X according to the present invention. The gas generator X has a cylindrical housing 1 and a gas generating agent pellet 2 ( Hereinafter, it is simply referred to as “gas generating agent 2”, the filter 3, the mesh member 13, and the ignition device 4. The housing 1 of the gas generator X includes an outer cylinder 5 having a long, bottomed cylindrical shape with one end opened, and an outer cylinder 5.
And an annular rib 6a formed on the outer peripheral edge of the lid member 6 and an opening end of the outer cylinder 5 are brought into friction contact with each other to form a sealed space. It has a structure to do. The filter 3 and the mesh member 13 are provided inside the housing 1 in a radially outward direction from the center of the shaft.
Are sequentially arranged, and the outer cylinder 5 is
Between the inner peripheral surface of the filter and the outer peripheral surface of the filter 3
Are formed. The gas generating agent 2 is loaded inside the filter 3. Reference numeral 15 denotes a cushion member disposed at the bottom of the outer cylinder 5 for the gas generating agent 2, the filter 3, and the mesh member 13.

A plurality of gas discharge holes 5a communicating with an airbag (not shown) are formed on the peripheral surface of the outer cylinder 5.
Each gas discharge hole 5a extends in the axial direction of the housing 1 and has a plurality of gas hole rows r1 spaced at an angle of 180 degrees in the circumferential direction.
To r6. Also, as shown in FIG. 1, each gas hole row r1 to r6 of each gas discharge hole 5a has a perforated portion α in which each gas discharge hole 5a is formed in the axial direction of the housing 1, It is formed in the outer cylinder 5 so that the non-porous portion β where the discharge hole 5a is not formed alternately appears. 7
Is a thin strip-shaped burst plate, which is a gas hole row r1.
R3 or r4 to r6 are adhered to the inner peripheral surface of the outer cylinder 5 so as to close the gas release holes 5a. As for the burst plate 7, six gas holes are used for each gas hole row r1 to r6.
It may be attached to the inner peripheral surface of the outer cylinder 5 so that each gas discharge hole 5a is closed every time, or one sheet may be wound and adhered to the inner peripheral surface of the outer cylinder 5. It is not excluded.

The filter 3 is composed of two filter units 3 A stacked in the axial direction of the housing 1, and is inserted in close contact with the inside of the mesh member 13. As the filter unit 3A, a knitted wire mesh [FIG.
(A)] or an assembly of crimp-woven wires (FIG. 4 (b)) is preferably press-formed into a cylindrical shape as shown in FIG. The length L of the filter unit 3A is such that the lamination boundary surface Z that contacts each other when laminated in the mesh member 3 is located at the non-porous portion β of each gas discharge hole 5a, that is, The position of the gas discharge hole 5a of the outer cylinder 5 and the position of the lamination boundary surface Z are designed to have a different positional relationship. Thus, even when the filter 3 is configured by laminating the plurality of filter units 3A, the high-temperature gas generated by the combustion of the gas generating agent 2 is not directly discharged from the laminating boundary surface Z to the airbag. The slag can be attached to and removed from the inner peripheral surface of the outer cylinder 5 by colliding with the inner peripheral surface of the outer cylinder 5, and the clean gas can be discharged from the gas passage space G to the airbag.

Each filter unit 3A of the filter 3
As shown in FIG. 5, two filter units 3A to be stacked are required to sufficiently exhibit the performance of collecting slag and the like.
It is preferable to insert an annular sealing material 16 between the layers (laminated boundary surface Z). As the sealing material 16, a molded article of heat-resistant ceramic fiber or a graphite sheet is preferable. When the sealing material 16 is inserted between the filter units 3A, the two filter units 3A
The flow of the high-temperature gas passing through the filter is blocked by the seal material 16, so that each filter unit 3A is effectively used as a whole in the axial direction, and the slag and the like contained in the high-temperature gas are reliably collected. While cooling.

Next, as shown in FIGS. 2 and 3, the mesh member 13 is formed into a cylindrical body using an inexpensive wire mesh (for example, a plain woven wire mesh) having a coarse mesh. A plurality of zigzag peaks 14A (or valleys 14B) having a predetermined width w as viewed in the radial direction are continuously formed on the entire circumference of the mesh member 13, and each zigzag peak is formed. Part 14A (or valley part 14)
B) is formed over the axial direction.
As shown in FIGS. 2 and 3, the width w of each zigzag crest (or valley) is in contact with the inner peripheral surface of the outer cylinder 5 and the outer peripheral surface of the filter 3 so that a predetermined gas passage space G is formed. It is set to form.

The mesh member 13 is inserted into the housing 1 so that the outwardly projecting ridges 14A are brought into close contact with the inner peripheral surface of the outer cylinder 5 (burst plate 7). Each valley portion 14B is closely attached to the outer peripheral surface of the filter 3 (each filter unit 3A), thereby holding each filter unit 3A while forming an annular gas passage space G between the outer cylinder 5 and the filter 3. . Further, one end of the mesh member 13 is closed by the cushion member 15 and the other end is closed by the cushion member 12 closing the filter unit 3A from the lid member 6 side, thereby sealing the gas passage space G from the outside. As the cushion material 12, a molded product such as a silicon foam or a ceramic fiber is preferable.

As a result, in the gas passage space G, FIG.
As shown in FIG. 3, a gas passage 17 communicating vertically and horizontally through a mesh is formed, and gas flowing from each filter unit 3A into the gas passage space G flows into each peak 14A (or valley) of the mesh member 13. While colliding with the portion 14B), the gas flows vertically and horizontally and is uniformly distributed in the gas passage space G.

The mesh member 13 is not limited to the above-described one, and the gas passage space G is formed by repeatedly folding the end of the cylindrical wire net on the outer peripheral surface of the cylinder many times. It is also possible to use a cylindrical multi-folded metal mesh having a sufficient opening and thickness.

The lid member 6 of the housing 1 is provided with an ignition device 4 composed of a transfer agent 9 and an igniter 10 (electric detonator). The transfer agent 9 of the ignition device 4 is provided on the protrusion 6b of the lid member 6 inserted into the filter 3 (filter unit 3A).
And a gap h, and is separated from the gas generating agent 2 by a flanged cap member 11 fitted into the lid member 6. The flange portion 11a of the cap member 11 extends to the cushion material 12, and its tip 11b is fixed by abutting against a burr 5b of the outer cylinder 5 formed when the outer cylinder 5 and the lid member 6 are pressed against each other. Cap member 11
A through hole 11d for transmitting an ignition flame to the gas generating agent 2 is formed in the convex portion 11c. Ignition device 10 of ignition device 4
The projection 1 of the cap member 11 is fitted into the lid member 6.
It is caulked and fixed so as to be opposed to the transfer agent 9 in 1c with a gap h.

Next, the operation of the gas generator X will be described. When a collision sensor (not shown) detects a collision of the vehicle, the igniter 10 of the igniter 4 is ignited by the collision detection signal to ignite the transfer agent 9 and the cap member 11
A flame is ejected from the through hole 11d toward the gas generating agent 2 to ignite the gas generating agent 2 and generate a high-temperature gas. The high-temperature gas generated in the housing flows into each filter unit 3A, passes through the circumferential direction of each filter unit 3A, collects slag, cools down, and the mesh member 1A.
3 flows out into the gas passage space G from the mesh.

At this time, the clean gas flowing out of each filter unit 3A into the gas passage space G is supplied to the mesh member 13
Of the zigzag wave-shaped peaks 14A (or valleys 14B), and collides with the inner circumferential surface of the outer cylinder 5 while passing through the meshes of the zigzag waves.
B) flows in the gas passing space G in the axial direction and the circumferential direction while colliding with B), so that the slag remaining in the gas is a mesh wire of each peak 14A (or each valley 14B) of the mesh member 13. In addition to the effect of being attached to and removed from the inner peripheral surface of the outer cylinder 5, the clean gas is also cooled by contact with the outer cylinder 5 and each wire of the mesh member 13. Further, the gas flowing out of each filter unit 3A into the gas passage space G is made uniform by the gas passage space G in the axial direction and the circumferential direction of the housing 1.

When the combustion of the gas generating agent 2 proceeds and the inside of the housing 1 reaches a predetermined pressure, each burst plate 7 ruptures and is made uniform in the axial direction and the circumferential direction of the gas passage space G. Clean gas is discharged from each gas discharge hole 5a to the airbag, and the airbag is rapidly inflated and deployed.

As described above, according to the gas generator X of the present embodiment, the mesh member 13 having the function of holding the filter 3 and defining the gas passage space G is arranged closest to the outer cylinder 5. Therefore, even if the diameter of the housing 1 is small, the mesh member 13 can have a size close to the inner diameter of the housing 1, and the formation of the mesh member 13 becomes easy. Also, mesh member 1
When the filter 3 is formed into a cylindrical body by a wire mesh, the filter 3 can be tightly inserted into the mesh member 13 and can be easily held by the valleys 14B protruding inside the mesh member 13. Further, the mesh member 13
Is formed by a coarse-meshed wire mesh, the same function can be achieved easily and inexpensively and easily without forming a plurality of gas passage holes unlike a conventional inner cylinder, and also has a function of forming a gas passage space G. Can be.

Further, since the filter 3 is composed of a plurality of filter units 3A, it is possible to easily and easily produce various long cylindrical gas generators having different lengths only by changing the number of stacked filter units 3A. Inexpensive.

Further, since the mesh member 13 has a mesh communicating the filter 3 with the gas passage space G over the entire surface in the circumferential direction and the axial direction, the high-temperature gas uniformly flows into each filter unit 3A. Therefore, a dead space where gas does not flow into the filter 3 is hardly formed, and the slag capturing efficiency of the filter 3 is improved.

When each of the gas hole rows r1 to r6 in which each of the gas discharge holes 5a is formed is closed by the burst plate 7 for every one or a plurality of rows, the entire circumference of the inner peripheral surface of the outer cylinder 5 is formed. It is no longer necessary to attach the burst plate 7 to the device, and the workability is improved.

In the gas generator X, an example has been shown in which the filter 3 is formed by stacking a plurality of filter units 3A. However, the present invention is not limited to this. A configuration in which the sealing member 16 is closely inserted into the member 13 may be employed, so that the gas discharge holes 5a of the outer cylinder 5 do not need to be shifted from the lamination boundary surface Z, and the sealing material 16 is provided on the lamination boundary surface Z of each filter unit 3A. There is no need to interpose.

[0028]

As described above, according to the gas generator of the present invention, the mesh member having the function of the inner cylinder is provided in the housing compared to the conventional system in which a filter is arranged between the inner cylinder and the housing. In order to reduce the size and weight of the gas generator, the mesh member can be made close to the inner diameter of the housing even if the housing is downsized. Thus, the formation of the mesh member becomes extremely easy. Also, since the gas passage space is formed by the mesh member,
Before the gas is released from the gas discharge hole of the housing, the gas pressure is made uniform in the gas passage space, the gas release from each gas discharge hole becomes uniform, and the airbag can be deployed normally as designed Becomes Further, the burst plate attached to the gas discharge hole is also ruptured by the gas equalized in the gas passage space, so that the burst plate is also ruptured substantially uniformly. It is possible to make the amount of gas released from the gas substantially uniform.

Further, when a mesh member formed into a cylindrical body by a wire mesh is used as the mesh member, gas can easily pass between the housing and the filter at the wavy peaks or valleys simply by inserting the mesh member into the housing. A space can be defined, and the filter can be easily held by the ridges or valleys protruding inward by closely inserting the filter into the mesh member. Further, when the mesh member is formed of a metal mesh having a coarse mesh, the same function can be achieved easily and inexpensively and easily without forming a plurality of gas passage holes unlike the conventional inner cylinder.
Can also be provided.

Further, when a filter is constructed by laminating filter units, it is possible to easily and inexpensively cope with a long gas generator simply by laminating a plurality of filter units. In addition, by arranging the lamination boundary surface of each filter unit so as to be shifted from the position of each hole of each cylinder, even when a configuration is adopted in which a plurality of filter units are laminated to form a filter, gas is directly transferred from the inner cylinder to the lamination boundary surface. The slag does not leak to the outside (airbag) through the surface, and the slag can be removed without fail by colliding with the inner peripheral surface of the housing.

Further, it is preferable that a sealing material for blocking the flow of the high-temperature gas between the filter units is interposed at the lamination boundary surface of each filter unit. Since the mutual flow in the axial direction is blocked by the seal material, the filter units can be effectively used in the axial direction, and the slag contained in the gas can be reliably captured and cooled.

Furthermore, when each gas discharge hole is closed by a burst plate for each of one or a plurality of gas hole rows, it is not necessary to attach a burst plate over the entire inner peripheral surface of the housing, thereby improving the workability. Can be improved.

[Brief description of the drawings]

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

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

3 is a view showing a structure of a mesh member used for a gas generator according to the present invention and an arrangement relationship between an outer cylinder and a filter, and is a cross-sectional view taken along the line BB of FIG. 2;

4A and 4B are diagrams illustrating an example of a filter unit used in the gas generator according to the present invention, wherein FIG. 4A is a diagram illustrating a knitted wire mesh, FIG. 4B is a diagram illustrating a crimp-woven wire, and FIG. FIG. 2 is a perspective view showing a cylindrical press-formed product.

FIG. 5 is an enlarged view of a main part of FIG. 1;

FIG. 6 is a sectional view showing a conventional gas generator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 housing 2 gas generating agent 3 filter 3A filter unit 4 ignition device 5 outer cylinder 6 lid member 7 burst plate 9 transfer agent 10 igniter 11 flanged cap member 12 cushion material 13 mesh member 15 cushion material 16 sealing material

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yoshiyuki Kishino 3903-39, Tomimachi, Himeji-shi, Hyogo Nippon Kayaku Co., Ltd. Himeji Factory Sensor Technology Co., Ltd. Himeji Technical Center (72) Inventor Kenichi Nagahashi Hyogo 3903-39, Toyotomi-cho, Himeji-shi, Japan Nippon Kayaku Co., Ltd.Sensor Technology in Himeji Factory, Himeji Technical Center Co., Ltd. (72) Inventor Seigo Taguchi 3903-39, Toyotomi-cho, Himeji-shi, Hyogo Himeji Technical Center in the factory Sensor Technology Co., Ltd.

Claims (4)

[Claims] 1. A gas generating agent (2), which has a plurality of gas discharge holes (5a) inside a housing (1) having an axial center.
In a gas generator comprising a filter (3) and a burst plate (7) for closing the gas discharge holes (5a) sequentially arranged, and an ignition device (4) mounted at an end, the housing (1) and the Gas generation characterized in that a mesh member (13) is arranged between the filter (3) and an annular gas passage space (G) is formed between the housing (1) and the filter (3). vessel 2. The filter (3) is composed of a plurality of filter units (3A) stacked in the axial direction of the housing (1), and the filter unit (3A)
2. The gas generator according to claim 1, wherein the knitted wire mesh or crimped wire rod is press-formed. 3. The gas discharge holes (5a) of the outer cylinder (5) are formed on the lamination boundary surface (Z) of the filter unit (3A).
The gas generator according to claim 1 or 2, wherein the gas generator is displaced from the position. 4. A sealing material (16) for intercepting a gas flow between the filter units (3A) is interposed on a lamination boundary surface (Z) of each of the filter units (3A). The gas generator according to any one of claims 1 to 3, characterized in that: