JP2000225914A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator capable of controlling breaking and expanding of an air bag according to a form of a vehicle collision, thereby showing an original function of the air bag. SOLUTION: A gas generator is provided with a cylindrical filter member 3 within a housing 1. The filter member 3 is filled with a gasifying agent 4, and two ignition instruments 5, 6 for burning the gasifying agent in the filter member 3 are disposed in the housing 1. By controlling actuation of each ignition instrument 5, 6 (simultaneous actuating, time differential actuating, only one actuating) to change the flow amount of gas discharged into the air bag and a gas pressure property, the air bag is developed and expanded according to a form of a vehicle collision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for expanding and inflating an airbag of a motor vehicle, and more particularly to a gas generator capable of controlling the form of deployment of the airbag.

[0002]

2. Description of the Related Art A gas generator for deploying and inflating an airbag is provided in an airbag module mounted in a steering wheel, an instrument panel, or the like to protect an occupant of the vehicle from an impact caused by a collision of the vehicle. It has been incorporated. The gas generator generates a large amount of high-temperature gas at the time of a collision according to a collision detection signal from a collision sensor.

As an example of a gas generator, there is a gas generator for deploying and inflating an airbag for a passenger seat or a side collision as shown in FIG. As shown in FIG. 7, the gas generator includes a long cylindrical housing 50 in which a sealed space S is formed by an outer cylinder 51 and a lid member 52. Filter member 5 cylindrical toward
3. The gas generating agent 55 is sequentially arranged. An igniter 56 ignited by a collision detection signal from a collision sensor (not shown) and an igniter 58 made of a transfer agent 57 ignited by the ignition of the igniter 56 are mounted on the lid member 52. . Then, the gas generator ignites the igniter 56 according to the collision detection signal from the collision sensor, ignites the transfer agent 57, and further ignites the ignition flame of the transfer agent 57 into the closed space S.
By ejecting the gas into the (filter member 53), the gas generating agent 55 is burned to generate a large amount of high-temperature gas. This high-temperature gas flows into the filter member 53, where it is collected and cooled, and then discharged from the gas discharge holes 51 a of the outer cylinder 51 into the airbag, whereby the airbag is deployed and inflated.

[0004]

In the conventional gas generator, regardless of the type of automobile collision (low-speed collision, high-speed collision, etc.), the ignition device is ignited by a collision detection signal from a collision sensor and a large amount of gas is ignited. Since the gas is generated and the airbag is deployed and inflated, there is a problem that the occupant cannot be properly protected according to the type of vehicle collision, and the original function of the airbag cannot be exhibited. In particular, as shown in FIG. 7, a gas generator for deploying an airbag for a passenger seat, etc.
A long cylindrical housing 1 is provided, and a gas generating agent 55 is burned from one axial end side of the housing 1 to generate a high-temperature gas. It takes time to generate a large amount of gas.

An object of the present invention is to provide a gas generator which makes it possible to control the deployment and inflation of an airbag in accordance with the type of vehicle collision, thereby achieving the original function of the airbag.

[0006]

According to the gas generator of the present invention, a filter member is arranged in a closed space in a housing,
A gas generating agent is loaded in the filter member, and a plurality of igniters for burning the gas generating agent in the filter member are arranged in the housing. By controlling the operation of each igniter (simultaneous operation, time lag operation, only one operation), the flow rate and gas pressure rise characteristics of the gas released into the airbag can be adjusted according to the collision type of the vehicle. Can be changed. Further, since no baffle plate or partition plate is required in the enclosed space, productivity can be improved.

The gas generator according to the present invention, which is applied to a gas generator for a passenger seat or a side collision, has a specific configuration in which both open ends of a long cylindrical outer cylinder are closed. A housing that forms a sealed space therein is provided, and a cylindrical filter member is disposed in both sides of the outer cylinder in the sealed space, and a gas generating agent is loaded in the filter member, and the housing is At each shaft end, there can be adopted a system in which an igniter for burning the gas generating agent in the filter member from each shaft end is disposed. It is also conceivable to apply a driver-side airbag having a short cylindrical housing to a gas generator that inflates and deploys.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas generator according to the present invention will be described. According to the present invention, the deployment form of the airbag can be controlled by making the gas generating agent loaded in the housing combustible by a plurality of igniters.

Hereinafter, a gas generator according to an embodiment of the present invention will be described with reference to FIGS. The gas generator Y shown in FIG. 1 expands and inflates a passenger seat or side collision airbag, and includes a long cylindrical housing 1, an inner cylindrical member 2 disposed in the housing 1, and a filter member. 3 and a gas generating agent 4 and two igniters 5 and 6 for burning the gas generating agent 4 in the housing 1.

The housing 1 is composed of a long cylindrical outer cylinder 7 having both ends opened, and two lid members 8 respectively closing the both ends of the outer cylinder 7. The housing 1 has a closed space inside by fitting each lid member 8 from each opening end of the outer cylinder 7 and bending the caulking projection 7 b protruding in the axial direction from each opening end of the outer cylinder 7 radially inward. S is formed.

On the peripheral surface of the outer cylinder 7, there are formed a plurality of gas discharge holes 7a communicating from the closed space S into an airbag (not shown). As shown in FIG. 2, for example, each gas discharge hole 7a is provided with three gas hole rows r1 to r3 and r4 to r6 at positions separated by an angle of 180 degrees in the circumferential direction of the housing 1.
These gas hole rows r1 to r6
The gas discharge holes 7a are formed at predetermined intervals in the axial direction of the housing 1. In addition, each gas hole row r1 to r6
Each gas discharge hole 7a is closed by a band-shaped burst plate 11 attached to the inner periphery of the outer cylinder 7. The burst plate 11 is formed of, for example, metal foil such as aluminum, and serves to prevent moisture in the sealed space S of the housing 1 and adjust the internal pressure during combustion.
Each gas outlet 7a has a length and width sufficient to close the gas discharge holes 7a. It is not excluded that one burst plate 11 is adhered over the inner circumference of the outer cylinder 7.

In the closed space S of the housing 1, an outer cylinder 7 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 inner cylindrical member 2 is formed in a cylindrical shape. The inner cylindrical member 2 extends from one lid member 8 to the other lid member 8 in the axial direction of the housing 1 and forms an annular gas passage space S1 with the inner periphery of the outer cylinder 7. ing. A plurality of gas passage holes 2a are formed in the peripheral surface of the inner cylindrical member 2 to communicate the inside thereof with the gas passage space S1. Each of these gas passage holes 2a is, as shown in FIG.
Are formed at predetermined intervals as viewed from the circumferential direction of the housing 1 and are formed in the axial direction of the housing 1.

As the inner cylindrical member 2, for example, FIG.
As shown in FIG. 3B, by uniformly pulling the base material 10 on which a large number of slits 10a are formed at predetermined intervals, FIG.
It is manufactured using an expanded metal having a plurality of gas passage holes 2a as shown in FIG. And the inner cylinder 2
Is manufactured by molding an expanded metal having a predetermined length and width into a cylindrical shape as shown in FIG. 3C, and fixing the ends to each other by a joining method such as spot welding. In addition, the base material 10 uses a stainless steel sheet having excellent heat resistance and pressure resistance, or a sheet steel other than stainless steel.

As described above, when the inner cylindrical member 2 is made of expanded metal, the slits 10a are subjected to the tensile processing in the arrow direction shown in FIG. 3 (a) as shown in FIG. From the flat portion B of the inner surface to the inner and outer peripheral sides by a height h. Therefore, the inner cylindrical member 2 protrudes from the outer periphery thereof by a height h at each slit 10a, and is formed with a plurality of gas passage holes 2a which are open in the circumferential direction and extend in the axial direction. It becomes a structure mutually connected in the circumferential direction. When the inner cylindrical member 2 is inserted into the housing 1, even if the inner cylindrical member 2 is expanded and deformed by the high-pressure high-temperature gas due to the combustion of the gas generating agent 4 in the closed space S of the housing 1, the inner cylindrical member 2 is moved up and down by the height h. Through the plurality of gas passage holes 2a projecting toward the respective gas discharge holes 7a. Thus, when the inner cylindrical member 2 is made of expanded metal, a continuous annular space is formed on the inner peripheral side of the outer cylinder 7 even if the inner cylindrical member 2 is arranged to be in contact with the inner periphery of the outer cylinder 7. It is possible to make this annular space a gas passage space S1.

The inner cylindrical member 2 is not limited to the one made of expanded metal, but may be a porous thin steel plate (punched metal plate) having a plurality of gas passage holes 2a formed at predetermined intervals. And the ends may be fixed 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 a space that forms a gas passage space S1 with the inner periphery of the outer cylinder 7.

The filter member 3 is formed in a cylindrical shape. The filter member 3 is closely fitted into the inner cylindrical member 2, and extends from one lid member 8 (one shaft end of the outer cylinder 7) in the axial direction of the housing 1 to the other lid member (outside). The shaft 7 extends to the other shaft end 8. As the filter member 3, for example, a knitted wire mesh shown in FIG. 5A or an aggregate of crimp-woven metal wires shown in FIG.
As shown in FIG. 5C, it can be manufactured inexpensively by press-forming into a cylindrical shape or winding it into a coil shape. The filter member 3 may be constituted by a plurality of filter units sequentially laminated in the axial direction of the housing 1. By appropriately changing the number of laminated filter units, the filter member 3 can correspond to the length of the housing 1 (outer cylinder 7). The filter member 3 can be arranged. The gas generating agent 4 is loaded in the filter member 3 along the axial direction of the housing 1.

Each of the igniters 5 and 6 comprises an igniter 14 and a transfer agent 15 ignited by the igniter 14, and is mounted on each of the lid members 8 constituting both ends of the housing 1. . Each igniter 14 is formed in a convex portion 8a of each lid member 8 and is caulked and fixed in a storage hole 16 communicating with the filter member 3 in a sealed state. Each of the igniters 14 is ignited by a collision detection signal from a collision sensor (not shown).
Further, each transfer agent 15 is provided from the inside of the housing 1 to each cover member 8.
Are housed in a flanged cap 17 fitted into the convex portion 8a of the cover member 8 and face the respective igniters 14 at intervals from the convex portion 8a of each lid member 8.

The projecting side 17a of each flanged cap 17 is
The filter member 3 is inserted into the filter member 3, and has a through hole 17 b for discharging the ignition flame of the transfer agent 15 into the filter member 3. The flange portion 17c of each cap 17 is
And is extended between the lid member 8 and the inner circumference of the outer cylinder 7, and is sandwiched between the lid member 8, the filter member 3, and the inner cylinder 2. A flange portion 17c of the cap 17 is an annular seal member 18 for closing the cover member 8 side of the filter member 3.
To seal the closed space S of the housing 1 from the outside.

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

The gas generator Y shown in FIG. 1 includes a igniter 5, a high-speed head-on collision, a frontal collision or a low-speed collision, which are detected by a collision sensor (not shown). 6 is appropriately controlled.

When the collision detection circuit determines from the collision detection signal from the collision sensor that the collision is a high-speed collision, each of the igniters 5, 6
Are simultaneously activated to ignite each transfer agent 15.
The ignition flame of each transfer agent 15 is jetted into the filter member 3 from the through hole 17b of each flanged cap 17, and the flame causes the gas on the both axial end sides (each lid member 8 side) of the housing 1 to flow. A high temperature gas is generated by forcibly igniting and burning the generator 4. At this time, the gas generating agent 4 in the filter member 3
Burns rapidly due to forced ignition by the igniters 5 and 6, spontaneous ignition by high-temperature gas, and the like, so that the gas pressure in the housing 1 also has a sharp pressure characteristic (see FIG. 6).

The high-temperature gas rapidly generated in the filter member 3 flows into the filter member 3 and
Through the slag collection and cooling at each gas passage hole 2 of the inner cylinder 2
a flows out into the gas passage space S1. Then, when the gas pressure rises abruptly with the combustion in the housing 1 and reaches a predetermined pressure, the burst plate 11 is broken, and the clean gas uniformized in the gas passage space S1 is discharged into the gas discharge holes 7a. From the airbag. Thus, the airbag is rapidly inflated and deployed by a large amount of gas generated by the combustion of the gas generating agent 4 and rapidly increasing in gas pressure.

When the collision detection circuit determines from the collision detection signal from the collision sensor that the collision is at a low speed, the ignition agent 15 is ignited by, for example, operating only the igniter 5.
The flame of the transfer agent 15 is jetted into the filter member 3, and the gas generating agent 4 on the one lid member 8 side (igniter 5 side) of the bowing 1 is forcibly ignited and burned by the flame to generate a high-temperature gas. At this time, the gas generating agent 4 of the filter member 4
After the forced ignition by the high temperature gas flowing into the other lid member 8 (igniter 6 side),
The rise in gas pressure in the housing 1 also has a pressure characteristic that is suppressed (dulled) as compared to operating the igniters 5 and 6 simultaneously (see FIG. 6).

The high-temperature gas gently generated in the filter member 3 flows into the filter member 3 and
Through the slag collection and cooling at each gas passage hole 2 of the inner cylinder 2
a flows out into the gas passage space S1. Then, when the gas pressure increases with the combustion in the housing 1 and reaches a predetermined pressure, the burst plate 11 is broken, and the clean gas uniformized in the gas passage space S1 is discharged into each gas discharge hole 7a.
From the airbag. Now the airbag is
The gas is expanded and deployed so as to be gently and weakly stretched by the gas whose rise in gas pressure has been suppressed (dulled) due to the combustion of the gas generating agent 4.

As described above, in the gas generator Y of the present invention,
With a simple structure in which the igniters 5 and 6 are disposed on the respective shaft end sides (each lid member 8) of the housing 1, the operation of each of the igniters 5 and 6 can be performed at a high speed collision or at a low speed collision. By simply controlling the airbag separately, the deployment mode of the airbag can be controlled in accordance with each type of collision, so that the function of the airbag body can be exhibited.

The igniters 5 and 6 may be operated at the same time, or only one igniter may be operated at a time difference depending on the accuracy of the collision detection circuit. For example, when the accuracy of the collision detection circuit is improved and high-speed, medium-speed, and low-speed collisions are detected, the igniters 5 and 6 are simultaneously activated by the high-speed collision to rapidly increase the airbag speed. Is deployed and inflated, and only one igniter 5 is operated in a low-speed collision, whereby the airbag is gradually deployed and inflated. In the case of a middle-speed collision, the igniters 5 and 6 are operated with a slight time difference, so that the airbag is gradually deployed at the beginning of the deployment of the airbag and then rapidly deployed and inflated.

That is, when the collision detection circuit determines from the collision detection signal from the collision sensor that the collision is at a medium speed, first, only one of the igniters 5 is actuated to ignite the transfer agent 15, and this flame is used. The high-temperature gas is generated by forcibly igniting and burning the gas generating agent 4 on one lid member 8 side (igniter 5 side) of the housing 1. At this time, the gas generating agent 4 of the filter member 3 is spontaneously ignited by the high-temperature gas flowing to the other lid member 8 (the igniter 6 side) after the forced ignition in the igniter 5, so that Also has a pressure characteristic that is suppressed (dulled) as compared to simultaneously operating the igniters 5 and 6 (see FIG. 6).

The high-temperature gas gently generated in the filter member 3 flows into the filter member 3, collects and cools the slag by the filter member 3, and passes through the gas passage holes 2 a of the inner cylindrical member 2. It flows out into the space S1. Then, when the gas pressure increases with the combustion in the housing 1 and reaches a predetermined pressure, the burst plate 11 is broken, and the clean gas uniformized in the gas passage space S1 is discharged into each gas discharge hole 7.
a to the airbag. Thus, the airbag is inflated and deployed in such a manner that the airbag is gently and weakly stretched by a small amount of gas generated by the combustion of the gas generating agent 4 and the gas pressure of which is suppressed (dulled) from rising.

Subsequently, when the other igniter 6 is operated with a slight time difference after the combustion of the gas generating agent 4 is started, the gas generation on the other shaft end side (the other lid member 8 side) of the housing 1 is performed. The agent 4 is forcibly ignited and combustion starts to generate hot gas. This high-temperature gas flows out into the gas passage space S1 and is discharged into the airbag from each gas discharge hole 7a. Therefore, the airbag is rapidly expanded and deployed by a large amount of clean gas by the operation of each of the igniters 5 and 6. Will be migrated to. At this time, the clean gas released into the airbag is added to the gas pressure at the time of operation of the igniter 5 by the gas generating agent 4 by the igniter 6.
As a result, the airbag is rapidly inflated and deployed with an equilibrium pressure of these gas pressures (see FIG. 6). With this, it is possible to perform a two-stage control in which the airbag is gently deployed and inflated in the initial stage of deployment, and rapidly deployed after a short time.

In the gas generator Y of FIG. 1, the housing 1 is composed of a long cylindrical outer cylinder 7 having both ends opened and two lid members 8 for closing the respective openings of the outer cylinder 7. However, the present invention is not limited to this. For example, a housing structure in which a closed space S is formed inside with a long cylindrical outer cylinder having a bottom at one end opening and a lid member closing the opening of the outer cylinder may be used. In this case, the lid member is fixed by caulking to the outer cylinder, or the lid member and the outer cylinder are joined by friction welding. In any case, there is no change in having two igniters 5 and 6. Further, the gas passage space S1 may be formed between the outer periphery of the filter member 3 and the inner periphery of the outer cylinder 7 without loading the inner cylinder material 2 into the outer cylinder 7.

Although the gas generator Y of the present invention has been described as being provided with the long cylindrical housing 1 to expand and inflate the airbag for the passenger seat or the side collision, the gas generator Y is provided with the short cylindrical housing. The present invention is also applicable to a driver-seat airbag that is deployed and inflated. When applied to a gas generator for a driver's seat, two igniters are arranged in a short cylindrical housing, and each igniter burns a gas generating agent from each shaft end side of the housing. Thus, a similar effect can be obtained. Further, in the present invention, the case where two igniters 5 and 6 are arranged in the housing has been described, but by arranging three or more igniters in the housing, the deployment of the airbag can be controlled in multiple stages.

[0033]

According to the gas generator of the present invention, a filter member is disposed in a housing, a gas generating agent is loaded in the filter member, and the gas generating agent in the filter member is burned in the housing. Since a plurality of igniters are arranged, the operation of each igniter is controlled (simultaneous operation, time difference operation, only one operation) by a simple configuration of arranging a plurality of igniters in the housing, so that the inside of the airbag is controlled. The flow rate and gas pressure characteristics of the gas released to the air can be changed. As a result, the airbag can be deployed and inflated according to the collision type of the vehicle, and the original function of the airbag can be exhibited. Further, since no baffle plate or partition plate is required in the enclosed space, productivity can be improved.

The specific configuration of the gas generator according to the present invention, which is applied to a gas generator for a passenger seat or a side collision, is, for example, that both open ends of a long cylindrical outer cylinder are closed. With a housing that forms an enclosed space inside
In this sealed space, a cylindrical filter member is arranged over both shaft ends of the outer cylinder, a gas generating agent is loaded into the filter member, and each shaft end of the housing has a filter member inside. Can be adopted in which an igniter for burning the gas generating agent from each shaft end side is disposed. Thus, even if the gas generator has a long cylindrical housing,
By controlling the operation of the two igniters, the airbag can be appropriately deployed and inflated in accordance with the type of collision.

[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 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. 4 is a sectional view showing a tension state of the expanded metal shown in FIG. 3;

5A and 5B are diagrams showing members for forming a filter member, wherein FIG. 5A is an enlarged view showing a knitted wire mesh, FIG. 5B is an enlarged view showing a crimp-woven metal wire, and FIG. 5C is a formed filter It is a perspective view which shows a member.

FIG. 6 is a graph showing a gas pressure rise characteristic of a gas generator.

FIG. 7 is a sectional view showing a conventional gas generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Inner cylinder material 2a Gas passage hole 3 Filter member 4 Gas generating agent 5, 6 Ignition device 7 Outer cylinder 7a Gas discharge hole 8 Cover member 14 Ignition device 15 Transfer agent Y Gas generator S Sealed space S1 Gas passage space

 ──────────────────────────────────────────────────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 F-term (reference) 3D054 DD13 DD18 DD21

Claims (3)

[Claims] 1. A gas generator comprising a housing (1) having a plurality of gas discharge holes (7a) and having a sealed space (S) formed therein, wherein: A filter member (3) is arranged, a gas generating agent (4) that generates gas by combustion is loaded in the filter member (3), and the housing (1) is provided with the gas inside the filter member (3). A gas generator comprising a plurality of igniters for burning a gas generating agent (4). 2. The housing (1) has a configuration in which both open ends of a long cylindrical outer cylinder (7) are closed to form a closed space (S) inside, and the closed space (S) is formed. Inside, a cylindrical filter member (3) is arranged over both axial ends of the outer cylinder (7), and the gas generating agent (4) is loaded into the filter member (3). At each shaft end of the housing (1), an igniter (5, 6) for burning the gas generating agent (4) in the filter member (3) from each shaft end side is arranged. The gas generator according to claim 1, wherein: 3. The gas generator according to claim 1, wherein each of the igniters is controlled by one of a simultaneous operation, a time difference operation, and only one operation.