JPH06183311A - Final filter for air bag unfolding gas generator - Google Patents

Abstract

PURPOSE:To increase cooling efficiency of combustion gas and collecting efficiency of combustion residue by providing a ceramic filter paper on the outer circumference of an inside foam metal porous body and an outside foam metal porous body on the outer circumference of the inside foam metal porous body and making an average diameter of the holes in the inside foam metal porous body larger than the average diameter of the holes the outside foam metal porous body. CONSTITUTION:The final filter has a ceramic filter paper 73 provided on the outer circumference of a cylindrical inside foam metal porous body 7 and an outside foam metal porous body 75 on the outer circumference of the ceramic filter paper 73. The average hole diameter of the outside foam metal porous body 75 is made larger than that of the inside foam metal porous body 71. In other words, for example, part number 5 of cellmeat is applied to the average hole diameter of the inside foam metal porous body 71 and part number 7 is applied to the outside foam metal porous body 75. Thus the inside foam metal porous body 71 carries out mainly combustion gas cooling and collection of relatively large size combustion residue. The outside foam metal porous body 75 carries out filter reinforcing and simultaneously combustion gas cooling.

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 used for deploying an airbag such as an airbag for a collision safety device, a lifesaving bag, a rubber boat, an escape chute, etc. by a combustion gas. , In particular, the air for cooling the combustion gas generated from the gas generating agent to the extent that the airbag is not burned, removing the combustion residues contained in the combustion gas, and supplying only harmless gas to the airbag. The present invention relates to a final filter for a gas generator for deploying a bag.

[0002]

2. Description of the Related Art Conventionally, in a passenger vehicle, a collision safety device for protecting a driver from a shock at the time of a collision is, for example, an airbag having a volume of 60 liters and a airbag for deploying the airbag with gas. It is composed of an airbag-deploying gas generator, and at the time of a collision of a passenger vehicle, an explosive filled in the airbag-deploying gas generator or a gas generating agent composed of a similar composition is ignited and burned, and its generation. The gas instantaneously deploys the airbag to protect the driver from collisions and prevent serious injury to the driver.

FIG. 3 shows a conventional gas generator for deploying an air bag disclosed in Japanese Patent Application Laid-Open No. 2-155857, in which reference numeral 11 indicates a plurality of gas generating agents 13.
Shows a combustion chamber housed in a stacked state. The gas generating agent 13 has an annular plate shape in which a through hole 15 is formed in the center, and the ignition agent 17 is accommodated in the through hole 15.

These gas generating agents 13 are contained in a sealed container 19
A recess 21 is formed at the center of the hermetically sealed container 19 and is recessed toward the through hole 15 side of the gas generating agent 13. An igniter 23 for burning the gas generating agent 13 is arranged in the recess 21.

A combustion chamber filter 25 is arranged along the inner circumference of the combustion chamber 11, and a gas which surrounds the combustion chamber 11 and has passed through the combustion chamber filter 25 flows from an orifice 26 into a charging chamber 27. Are arranged in a ring. A filling chamber filter including an upper filter 29 and a gas filtration filter (final filter) 31 is housed in the filling chamber 27.

Further, in the charging chamber 27, there is formed a gas outlet 33 for discharging the gas passing through the gas filter 31 to the airbag. In such an airbag-deploying gas generator, when electricity is applied to the igniter 23, the explosive in the igniter 23 burns to ignite the igniting charge 17, and the combustion causes the gas generant 13 to burn. Then, the gas of the gas generating agent 13 passes through the combustion chamber filter 19 arranged along the inner circumference of the combustion chamber 11 and flows into the charging chamber 27, and then is purified by the upper filter 29 and the gas filtration filter 31. The gas then passes through the gas outlet 33 and flows into the airbag, and the airbag is sufficiently inflated in a short time of, for example, about 0.04 seconds.

FIG. 4 shows an airbag deployment gas generator for which the applicant of the present invention has applied for a patent on October 8, 1990. The airbag deployment gas generator is shown in FIG.
3 is a long tubular member 41 in which a gas outlet 45 is formed.
On both sides of the combustion chamber 51, 5 in which the gas generating agent 47 is accommodated
3 is formed by the partition members 55 and 57, and the cylindrical final filter 5 is provided inside the intermediate portion 43 of the cylindrical member 41.
9 is arranged, an intermediate filter 61 is arranged between the final filter 59 and the partition members 55, 57 inside the tubular member 41, and the orifice is provided at a position lateral to the intermediate filter 61 of the partition members 55, 57. 63 is opened.

According to this air bag deployment gas generator, the combustion gas capacity of the gas generant 47 can be significantly increased and the large capacity combustion gas can be reliably purified. , Further, gas generating agent 4
The combustion of 7 can be easily adjusted. On the other hand, conventionally,
The final filters 31 and 59 shown in FIG. 3 and FIG. 4 are formed, for example, by superposing a fine wire mesh, a woven woven wire mesh, and the like, and the final filters 31 and 59 are such that the combustion gas is not burned by the airbag. It also has the function of cooling to room temperature, removing the combustion residue contained in the combustion gas, and supplying only harmless nitrogen gas to the airbag.

[0009]

However, in the final filters 31 and 59 of such a conventional gas generating apparatus for deploying an air bag, since the fine wire mesh, the woven woven wire mesh and the like are wound to form the filter. However, there is a problem that a large number of manufacturing steps are required and the manufacturing cost is increased.

Further, the cooling efficiency of the combustion gas and the collection efficiency of the combustion residue contained in the combustion gas have not always been sufficient. The present invention solves the above-mentioned problems, is easy to manufacture, and greatly increases the cooling efficiency of combustion gas and the collection efficiency of combustion residues contained in combustion gas, as compared with the prior art. An object of the present invention is to provide a final filter of a gas generator for deploying an airbag that can be used.

[0011]

A final filter of a gas generator for expanding an air bag according to the present invention cools a combustion gas generated from a gas generating agent to such an extent that the air bag is not burned and is converted into a combustion gas. In the final filter of the gas generator for airbag deployment, which removes the combustion residues contained and supplies only harmless gas to the airbag, it surrounds the outer periphery of the cylindrical inner foam metal porous body, and the ceramic filter paper And the outer foam metal porous body is arranged so as to surround the outer periphery of the ceramic filter paper, and the average pore diameter of the inner foam metal porous body is made larger than the average pore diameter of the outer foam metal porous body. is there.

[0012]

In the final filter of the gas generator for airbag deployment of the present invention, the inner foam metal porous body mainly cools the combustion gas and collects a relatively large combustion residue contained in the combustion gas. Be done. Moreover, the ceramic filter paper collects minute combustion residues contained in the combustion gas.

Further, the outer foam metal porous body reinforces the filter, and at the same time, the combustion gas is cooled.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the final filter of the gas generator for airbag deployment of the present invention, and this final filter is used in place of the final filter of FIG. 3 described above.

In the figure, reference numeral 71 indicates, for example, an inner diameter 60.
A cylindrical inner metal foam body having a thickness of about 4 mm and a wall thickness of about 4 mm is shown. A ceramic filter paper 73 having a wall thickness of, for example, about 2 mm is arranged so as to surround the outer periphery of the inner foam metal porous body 71. Further, by enclosing the outer circumference of the ceramic filter paper 73, for example, a wall thickness of 1 mm
The outer foam metal porous body 75 of about a certain degree is arranged.

The inner foamed metal porous body 71 and the outer foamed metal porous body 75 are formed, for example, by subjecting a foamed resin to a conductive treatment.
For example, nickel, nickel-chromium alloy or the like is electroplated and heat-treated to form a three-dimensional mesh-like skeleton like sponge. In this embodiment, for the inner foam metal porous body 71 and the outer foam metal porous body 75, for example, Celmet (trade name of Sumitomo Electric Industries, Ltd.) is used.

The average pore diameter of the inner foam metal porous body 71 is, for example, 5 in the Celmet part number, and the average pore diameter of the outer foam metal porous body 75 is, for example, in the Celmet part number 7, The average pore diameter of the foam metal porous body 71 is set to be larger than the average pore diameter of the outer foam metal porous body 75. On the other hand, the ceramic filter paper 73 is formed, for example, by adding an organic or inorganic binder to polycrystalline alumina short fibers or polycrystalline silica short fibers.

The ceramic filter paper 7
The density as the filter of No. 3 is 75
The density is set to capture particles that are sufficiently smaller.
In the final filter of the gas generator for deploying the airbag configured as described above, the inner foamed metal porous body 71
Mainly, the combustion gas is cooled and a relatively large combustion residue contained in the combustion gas is collected.

The ceramic filter paper 73 collects minute combustion residues contained in the combustion gas. Further, the outer foam metal porous body 75 reinforces the filter, and at the same time, cools the combustion gas. Then, in the final filter of the gas generator for airbag deployment configured as described above, the final filter is surrounded by the outer circumference of the cylindrical inner foam metal porous body 71.
The ceramic filter paper 73 is arranged, the outer foam metal porous body 75 is arranged so as to surround the outer periphery of the ceramic filter paper 73, and the average pore diameter of the inner foam metal porous body 71 is set to the average pore diameter of the outer foam metal porous body 75. Since it is configured to be larger, it is possible to easily manufacture, and it is possible to significantly increase the cooling efficiency of the combustion gas and the collection efficiency of the combustion residue contained in the combustion gas, as compared with the conventional case.

That is, in the final filter configured as described above, the final filter is the inner foam metal porous body 7
1. The final filter can be manufactured very easily because the final filter can be manufactured by arranging the ceramic filter paper 73 and the outer foam metal porous body 75 in three layers and compressing them, for example. be able to.

The final filter is formed by arranging the inner foamed metal porous body 71, the ceramic filter paper 73 and the outer foamed metal porous body 75 in three layers. Cooling, and
The relatively large combustion residue contained in the combustion gas is collected, and the minute combustion residue contained in the combustion gas is collected by the ceramic filter paper 73. Further, the outer foamed metal porous body 75 collects the filter. Since the reinforcement and the cooling of the combustion gas are performed, the collection efficiency of the combustion residue of the combustion gas can be significantly increased as compared with the conventional case.

Since the foamed metal porous body is used,
Since the combustion gas flows three-dimensionally in the porous metal porous body, the efficiency of collecting the combustion gas combustion residue can be significantly increased. Further, since the foamed metal porous body is used, it is possible to improve the cooling efficiency of the combustion gas, and
The weight of the final filter can be reduced.

Further, since the cooling efficiency and the trapping efficiency of the combustion gas are greatly increased as compared with the conventional one, the final filter can be downsized. Furthermore, since the foamed metal porous body is used, it is possible to sufficiently muffle the abnormal noise of the combustion gas. FIG. 2 shows another embodiment of the final filter of the gas generator for airbag deployment of the present invention, and this final filter is used in place of the final filter of FIG. 4 described above.

In the figure, reference numeral 77 indicates, for example, an inner diameter 25.
It shows a cylindrical inner foam metal porous body having a thickness of 10 mm, a wall thickness of 10 mm, and a length in the axial direction of about 85 mm. A ceramic filter paper 79 having a thickness of, for example, about 3 mm is arranged so as to surround the outer circumference of the inner foam metal porous body 77. Further, surrounding the outer periphery of the ceramic filter paper 79, for example, an outer foam metal porous body 81 having a wall thickness of about 3 mm.
Are arranged.

Even in the final filter constructed as described above, substantially the same effect as that of the embodiment shown in FIG. 1 can be obtained.

[0026]

As described above, in the final filter of the gas generator for deploying the air bag of the present invention, the final filter is surrounded by the outer circumference of the cylindrical inner foam metal porous body and the ceramic filter paper is arranged. Then, while arranging the outer foam metal porous body surrounding the outer periphery of this ceramic filter paper, the average pore diameter of the inner foam metal porous body is configured to be larger than the average pore diameter of the outer foam metal porous body. There is an advantage that the manufacturing is easy and the efficiency of cooling the combustion gas and the efficiency of collecting the combustion residue contained in the combustion gas can be significantly increased as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a final filter of a gas generator for airbag deployment according to the present invention.

FIG. 2 is a perspective view showing another embodiment of the final filter of the gas generator for airbag deployment of the present invention.

FIG. 3 is a vertical cross-sectional view showing a conventional gas generator for deploying an airbag.

FIG. 4 is a vertical sectional view showing a gas generating device for deploying an airbag, which the applicant of the present invention has previously filed.

[Explanation of symbols]

 71, 77 inner foam metal porous body 73, 79 ceramic filter paper 75, 81 outer foam metal porous body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Uechi 1-4-1 Chuo, Wako City, Saitama Prefecture Honda R & D Co., Ltd.

Claims (1)

[Claims] 1. A combustion gas generated from a gas generating agent is cooled to such an extent that the airbag is not burned, and combustion residues contained in the combustion gas are removed to supply only harmless gas to the airbag. In the final filter of the gas generator for deploying an air bag of, the ceramic foam paper is arranged by surrounding the outer periphery of the cylindrical inner foam metal porous body, and the outer periphery of the ceramic filter paper is surrounded by the outer foam metal porous body. And the average pore diameter of the inner foam metal porous body is made larger than the average pore diameter of the outer foam metal porous body, the final filter of the gas generating device for airbag deployment.