JPH06171452A - Gas generator - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of a gas producing agent, miniaturize the generator, enhance the charging convenience of this gas producing agent into a gas generator vessel by preventing any powdering of the gas producing agent due to vibration or the like from occurring. CONSTITUTION:A bottomed cylindrical vessel 1 is held in a sealed state as a cover body 4 is fitted and clamped tight. Each gas port 3 is installed on a peripheral wall 2 of the vessel 1 at regular intervals. An igniter 7 forming an ignition system 6 and an ignition agent 8 are set up each on a central axis of the vessel. A gas producing agent 9 is set up on a circumference of the ignition system 6. This gas producing agent 9 is formed into a cylindrical form by means of an extrusion molding process, and plural pieces of the cylindrical agent are densely loaded to an axis of the vessel 1 in an almost parallel manner. A cooling collector material 10 is interposed between the peripheral wall 2 of the vessel 1 and the gas generating agent 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator which is mounted in, for example, a passenger compartment of an automobile and is used in an airbag for protecting an occupant in the event of a collision.

[0002]

2. Description of the Related Art Generally, a gas generator has an ignition device built in the center of a cylindrical or disk-shaped metal closed container.
A gas generating agent is arranged on the outer periphery of the container, and a gas ejection hole is provided on the peripheral wall of the container. Then, when the ignition device is ignited, the gas generating agent burns to generate gas, and the generated gas is ejected from the gas ejection hole into the airbag,
The airbag is deployed.

Among such gas generators, the gas generators for the front passenger seat and the rear seat generally use a long cylindrical container because of the mounting space. The gas generating agent contained in the container is generally used in the form of pellets or disks.
Examples thereof include US Pat. Nos. 4,878,690 and 48.
The gas generator described in No. 17828 etc. is mentioned.

In US Pat. No. 4,878,690,
A gas generator for the passenger seat is disclosed. That is, as shown in FIG. 5, the metal container 21 has a bottomed cylindrical shape, and the lid 22 is fitted and fixed to the open end of the container 21 to be in a hermetically sealed state. The gas outflow holes 24 are provided through the peripheral wall 23 of the container 21 at a predetermined interval. The igniter 25 and the igniting agent 26 are arranged on the central axis of the container 21, and a large number of pelletized gas generating agents 27 are loaded around the igniter 25 and the igniting agent 26. The cooling filter material 28 is interposed between the peripheral wall 23 of the container 21 and the gas generating agent 27.

Then, the igniter 25 is ignited and the igniter 26 is ignited.
When the gas is ignited, the gas generating agent 27 burns, and the generated gas flows out from the gas outflow hole 24 through the cooling filter material 28,
The airbag is deployed.

US Pat. No. 4,817,728 also discloses a passenger side gas generator. That is, FIG.
As shown in FIG. 3, this gas generator contains a plurality of disk-shaped gas generating agents 30 each having a large number of through holes 29. Then, the through hole 29 of each gas generating agent 30
Are stacked in the lengthwise direction of the container 21 in an aligned state. Then, the flame of ignition by the igniter 25 moves through the through holes 29 communicated with each other, so that the ignitability is improved.

[0007]

However, the former gas generator has the following problems. That is, since the pelletized gas generating agent 27 has a large surface area, the igniter 2
6 has good ignitability at the time of ignition by 6, and has the advantage that desired gas generating characteristics can be obtained by changing the shape of pellets, but on the other hand, when loading a predetermined amount of gas generating agent 26 Since the rate is large, there is a problem that a large volume is required. This leads to an increase in the size of the gas generator, and there is a problem that it becomes difficult or impossible to mount the gas generator, for example, when it is mounted in the passenger compartment of an automobile, particularly a small passenger car.

Further, the pellet-shaped gas generating agent 27 allows the pellets to move little by little due to vibration or shock received after the pellets are loaded even when the pellets are loaded very densely when the pellets are loaded when the gas generator is produced. The surface of the pellet may be rubbed and the gas generating agent may be pulverized. The pulverization of the gas generating agent 27 causes a problem that the combustion pattern of the gas generating agent 27 is changed and an abnormally high pressure is generated when the gas generating agent is burned.

On the other hand, the latter gas generating agent 30 has the advantages that the packing density can be increased and the gas generator can be downsized, but on the other hand, the gas generating agent 30 having the through holes 29. The manufacturing of the disc is very complicated. That is, it is necessary to form the through hole by removing the pin after compression-molding in a die in which the pin is upright. Further, when stacking these discs, it is necessary to align the positions of the through holes 29 between the discs, which causes a problem of poor workability during loading.

The present invention has been made in view of the above problems, and its purpose is to reduce the risk of powdering of the gas generating agent due to vibration and the like, to ensure miniaturization, and to use it for a gas generator container. Another object of the present invention is to provide a gas generator excellent in loading property of the gas generating agent.

[0011]

To achieve the above object, in the gas generator of the present invention, an ignition device and a gas generating agent are arranged in a container of a cylindrical closed container, and the peripheral wall of the container is provided. A gas generator having an ejection hole for ejecting generated gas to the outside of a container, wherein the gas generating agent is formed in a rod shape, and a plurality of the gas generating agents are loaded substantially parallel to the axis of the container. It is characterized by

[0012]

In the gas generator of the present invention, the gas generating agent is formed in the shape of a rod and is loaded into the container as it is. Further, the rod-shaped gas generating agent is loaded in the gas generator container as it is along the axis of the container. Therefore, the gas generant can be easily loaded into the container. In addition, since a plurality of gas generating agents are loaded almost parallel to the axis of the container, it is difficult for the gas generating agents to move due to vibration, etc. Powdering is prevented.

Further, unlike the pellet-shaped gas generating agent, the gas generating agent can be arranged substantially parallel to the axis to reduce the porosity, so that the gas generator can be downsized. be able to.

When the ignition device is ignited by the ignition signal, the ignition energy ignites and burns the gas generating agent arranged outside the ignition device to generate a large amount of gas. This gas is ejected outward from the ejection holes provided on the peripheral wall of the metal container to inflate, for example, an airbag.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIGS. As shown in FIGS.
The gas generator container 1 is in the shape of a long bottomed cylinder, and the peripheral wall 2 thereof is provided with gas ejection holes 3 at regular intervals in the longitudinal direction. The lid 4 is attached and fixed to the container 1 by fitting the open end of the container 1 into the annular engaging projection 5, and the inside of the container 1 is maintained in a sealed state. The electric igniter 7 that constitutes the ignition device 6 includes an engagement hole 4a at the center of the lid 4.
Is fixed by being inserted into and is ignited by an ignition signal. The igniting agent 8 constituting the ignition device 6 is arranged in the center of the container 1 along the central axis of the container 1. Then, the ignition agent 8 is ignited and burned by the ignition of the igniter 7. It should be noted that the ignition device 6 may have a structure arranged only near one end of the container 1.

The gas generating agent 9 is integrally formed in a rod shape (strand shape) shown in FIG. 3 with a length corresponding to the length of the container 1,
A plurality of igniting agents 8 are arranged on the outer periphery in parallel with the axis of the container 1. The gas generating agent 9 burns with the ignition of the igniting agent 8 to generate gas. The cooling scavenger 10 is composed of a wire net and cools the gas generated by the combustion of the gas generating agent 9 and at the same time filters the residue generated together with the gas.

The gas generating agent 9 is manufactured, for example, by the extrusion molding method as follows. That is, an appropriate amount of a solvent is added to a raw material composed of a binder such as nitrocellulose, cellulose acetate, and ethyl cellulose, an oxidizing agent such as perchlorate and nitrate, a plasticizer, an additive such as a combustion modifier, and the mixture is uniformly mixed. , Prepare the drug mass. Next, this drug mass is loaded into a companding machine. A die having a predetermined size and shape is attached to the companding machine, and the drug mass is extruded by being passed through the die by pressure and formed into a desired shape. This is cut into a suitable length according to the dimensions of the gas generator and dried to give a cylindrical gas generating agent 9
Is obtained.

The shape of the cylindrical gas generating agent 9 is not limited to a circular cross section, but a C-shaped cross section as shown in FIG.
It may be a single-hole tube having a through hole at the center or a multi-hole tube having a large number of holes. These shapes may be used alone or in combination depending on the gas generation characteristics required for the gas generator. In general, if the same gas generating agent 9 and the same amount are used, the larger the surface area is, the more rapidly the gas generating characteristics rise, and the shorter the burning time is, which is preferable.

Further, the total cross-sectional area of the rod-shaped gas generating agent 9 in an aligned arrangement is 0.
It is preferably in the range of 6 to 0.95. This value is 0.6
If less than, since it has a large porosity as in the case of using a conventional pellet-shaped gas generating agent, it is difficult to miniaturize the gas generator, and if it exceeds 0.95, flame of ignition Since the propagation is poor, there is a possibility that the ignition of the gas generating agent 9 may be poor. The number of the gas generating agents 9 accommodated is appropriately determined so that the total cross-sectional area of them is within the above range.

In the gas generator of this embodiment, the igniter 7 is ignited and the igniter 8 is ignited based on the ignition signal. And with this ignition energy,
The gas generating agent 9 arranged outside the ignition device 6 is ignited and burned to generate a large amount of gas. This gas is cooled by the cooling and collecting material 10 and the generated residue is collected. Then, the gas is ejected outward from a gas ejection hole 3 provided in the peripheral wall 2 of the container 1, and an airbag, for example, is deployed. At this time, the gas generating agent 9 is formed in a cylindrical shape and has a large surface area, and since there is a gap between the gas generating agents 9, the flammability of the gas generating agent 9 in the axial direction and the radial direction of the container 1 is improved. Are better.

As described above, in the gas generator of this embodiment, the gas generating agent 9 is integrally molded in a cylindrical shape by the extrusion molding method to a length substantially corresponding to the length of the container 1, and then cut. Since no work is required, its manufacture is easy. Moreover, the gas generating agent 9 is a cylindrical solid body,
Since there is no through hole inside, there is no need to form a through hole, and the manufacturing becomes easier accordingly. In addition, since the rod-shaped gas generating agent 9 may be loaded in the container 1 as it is along the axis of the container 1, it is easy to load it in the container 1. In addition, since the plurality of gas generating agents 9 are densely packed substantially in parallel with the axis of the container 1, the gas generating agents 9 are unlikely to move due to vibration or the like, and there is little frictional contact with each other. The pulverization of the gas generating agent 9 is prevented, and the gas generating characteristics are unlikely to change.

Moreover, unlike the pellet-shaped gas generating agent, the porosity can be reduced by the arrangement.
That is, since the loading density of the gas generating agent 9 can be increased, it is possible to ensure downsizing of the gas generator.

The present invention is not limited to the above-described embodiments, but may be embodied by arbitrarily changing the configuration as described below, for example, without departing from the spirit of the invention. (A) Form the gas generating agent 9 to have an elliptical cross section, a polygonal cross section, or the like. (B) Making the shape of the cylindrical container 1 an elliptic cylinder or a rectangular cylinder. (C) Arranging a plurality of gas generating agents 9 side by side in the length direction of the container 1.

[0024]

As described above in detail, according to the present invention,
Since the gas generating agent is formed in a rod shape, the rod-shaped gas generating agent can be loaded into the container of the gas generator as it is along the axis of the container, and therefore the effect of excellent loading performance can be obtained. . Moreover, since a plurality of gas generating agents are loaded almost parallel to the axis of the container,
Since each gas generating agent does not easily move due to vibration or the like and frictional contact with each other is small, it is possible to prevent powdering of the gas generating agent. Moreover, unlike the pellet-shaped gas generating agent, it is possible to reduce the porosity by arranging the gas generators in an aligned manner, so that it is possible to obtain the effect of ensuring miniaturization of the gas generator.

[Brief description of drawings]

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

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

FIG. 3 is a perspective view showing a gas generating agent in a strand form.

FIG. 4 is a perspective view showing a gas generating agent in a strand form, which represents another example of the present invention.

FIG. 5 is a sectional view showing a conventional gas generator.

FIG. 6 is a cross-sectional view of a gas generator showing another conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas generator container, 2 ... Peripheral wall, 3 ... Gas ejection hole, 4
... Lid, 6 ... Ignition device, 9 ... Gas generating agent.

Claims (1)

[Claims] 1. A gas generator in which an ignition device and a gas generating agent are arranged in a container of a cylindrical closed container, and an ejection hole for ejecting the generated gas to the outside of the container is provided on the peripheral wall of the container. The gas generating agent is formed in a rod shape, and a plurality of the gas generating agents are loaded substantially parallel to the axis of the container.