JP2001171473A - Filter for gas generator for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter improving the effect of cooling combustion product gas of a gas generator for an air bag, positively collecting solid residue (large residue and small residue), and improving the capacity of combustion pressure control for freely regulating resistance to gas flow with this filter constitution. SOLUTION: This filter comprises an annular punching metal 20 (20A) with a large number of pores, and an annular metallic wire woven gauze body 30 (30A) disposed on the inner peripheral side of the annular punching metal 20 (20A).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter used for a gas generator for an air bag, and more particularly, to cooling of a combustion product gas of a gas generating agent contained in the gas generator for an air bag. The present invention relates to a filter for collecting solid residues.

[0002]

2. Description of the Related Art Conventionally, a filter used in a gas generator for deploying an airbag (gas generator for an airbag) mainly cools a combustion product gas and collects a solid residue of the combustion product gas (that is, a solid residue of the combustion product gas). , Filtration). The filter for filtering the combustion product gas is selected from a coarse or fine mesh of steel wire mesh (mesh member) from the kind of the gas generating agent composition and the structure of the gas generator, etc. It is used by laminating and winding.

[0003] Further, various kinds of wire netting and a filtering material other than the wire netting such as a porous ceramic body are combined and wound in a cylindrical shape. Japanese Patent Application Laid-Open No. 1-293112 discloses a knitted wire mesh in which a cylindrical body is formed by a knitted wire mesh made of stainless steel wire, and a plain woven wire mesh made of a stainless steel wire is wound like a belt to form an annular body. A gas generator filter is disclosed in which a part of the cylindrical body is inserted through an annular body of a plain-woven wire mesh and wound, and the remaining part of the cylindrical body is bag-wrapped, and these are compression-molded to obtain a two-layered annular filter. I have.

In this filter, a high-temperature gas is cooled by a plain weave wire mesh and a part of harmful products is collected, and the knitted wire mesh further cools and collects the remaining harmful products. Have been. JP-A-2-1
In Japanese Patent No. 55861, a metal fiber sintered cloth is wound in a cylindrical shape around an inorganic fiber sheet on the outer periphery of the innermost fine mesh, and the fine mesh is further wound on the tatami-woven metal mesh and the outermost circumference. A gas filter for an airbag deployment gas generator is disclosed.

In this filter, the fine mesh cools the gas to improve the strength of the filter, the inorganic fiber sheet filters the fine powder, and the sintered metal fiber cloth breaks the inorganic fiber sheet by the combustion product gas flow. It is said that the woven wire mesh backs up the sintered metal fiber cloth and improves the strength of the filter. In recent years, wire meshes and metal fibers that have been mainly used in the past have been reviewed, and studies have been made on improving the pressure resistance and the cooling effect, and there has been a tendency to use punched metal, expanded metal, and the like.

Japanese Patent Application Laid-Open No. 11-43007 discloses that an expanded metal having a large number of openings is used by laminating a plurality of layers in a cylindrical shape, or a metal mesh having a coarser mesh than the expanded metal is provided on an intermediate layer of the expanded metal. A gas generator filter in which at least one layer is interposed is disclosed.

In this filter, the high-temperature gas collides with the metal surface of the laminated expanded metal and adheres to the metal surface to collect slag (solid residue). The expanded metal having a large heat capacity causes the high-temperature gas to generate heat. It is supposed to be taken down and cooled down to an appropriate temperature.

[0008]

However, in recent years,
The gas generator for airbag gas generators has shifted from azide-based gas generators to non-azide-based gas generators. It has the property of being less flammable than the azide gas generating agent.

In order to improve the usefulness as a gas generating composition in which a base having such properties is mixed, components other than the base such as an oxidizing agent must be blended. It may become a gas generating agent with a large amount of residue, and improvement of the filtering effect is a proposition. In recent years,
Gas generators are becoming smaller, lighter and more cost-effective,
It became important to consider the elements of the filtration filter from the structural aspect of the gas generator.

In particular, the simplification of the structure of the gas generator has simplified the gas flow path for filtering the gas, and as a result, the gas flows into the filter at high speed and high temperature.
For these reasons, adjustment of the tank pressure output, cooling, collection of residues, and the like of the combustion product gas generated in the gas generator and deploying the airbag have become important issues.

However, in the above-mentioned filter using only the conventional steel wire netting in combination, the trapping is limited to the case where gas flows in the direction perpendicular to the wire netting surface.
It has been difficult to collect the residue with respect to the gas flow passing in the same direction as the wire mesh surface, and it has been difficult to finely adjust the gas temperature and output only by changing the number of wire mesh layers (the number of turns).

Also, in a filter using a combination of a steel net or the like and a metal fiber sintered cloth or a porous ceramic filter, the metal fiber sintered cloth is weak to heat and can be destroyed unless the gas is sufficiently cooled. Nature, and
It has been pointed out that porous ceramics are vulnerable to heat shock and can be destroyed by sudden application of heat. Also, these materials have high resistance to gas flow, and it is very difficult to adjust the pressure of the combustion chamber when used.

[0013] Further, for a filter using a combination of expanded metal and a steel wire netting,
It is disclosed in the above-mentioned JP-A-11-43007 and JP-A-10-297418 by the present applicant. In Japanese Patent Application Laid-Open No. 10-297418, the expanded metal is referred to as a metal lath.

Here, a metal lath and a flat knitted knitted woven wire mesh are laminated and arranged as a filter in the combustion chamber of the gas generator. In this filtration filter, while cooling with the knitted woven wire mesh and collecting solid residues, the gas flowing into the knitted woven wire mesh flows evenly by the metal lath.

However, further experiments by the present inventors have revealed that it is necessary to improve the cooling effect and to collect fine residues. In addition, as described above, in recent years, research and development of non-azide gas generating agents have been performed from the aspect of environment and the like. Examples of non-azide gas generating agents include nitrogen-containing organic compounds (eg, tetrazole derivatives, guanidine derivatives). Etc.) have been studied.

However, these bases are relatively incombustible in nature and tend to increase solid residues. The extent to which this solid residue tends to be increased is influenced by the composition of the base of the gas generating agent and the oxidizing agent.

Therefore, by appropriately combining the above-described punching metal and the various metal wire woven wire meshes with the filter structure by the gas generating agent used for the gas generator for the air bag, the cooling of the combustion gas and the solid residue can be reduced. The inventors have found that the airbag can be deployed with the collected clean gas and that the resistance to the gas flow can be freely adjusted, and the present invention has been completed.

The present invention has been made on the basis of this finding, and its object is to improve the cooling effect of the combustion product gas of the gas generator for an air bag and to reliably remove solid residues (large and fine residues). It is to provide a filtration filter for collecting. Another object of the present invention is to provide a filter capable of improving a combustion pressure control ability capable of freely adjusting a resistance to a gas flow by this filter configuration.

[0019]

The invention according to claim 1 is
It is characterized by comprising an annular punching metal having a large number of openings, and an annular metal wire woven metal net arranged on the inner peripheral side of the annular punching metal. According to a second aspect of the present invention, in the filter for an airbag gas generator according to the first aspect, the metal wire woven wire mesh is a knitted wire mesh.

According to a third aspect of the present invention, in the filter for an airbag gas generator according to the first aspect, the metal wire woven wire mesh is combined with a knitted woven wire mesh, a tatami woven wire mesh and a twill woven wire mesh. It is characterized by being a body.
According to a fourth aspect of the present invention, in the filter for an airbag gas generator according to the first aspect, the perforated metal and the metal wire mesh are made of stainless steel.

According to a fifth aspect of the present invention, in the filter for an airbag gas generator according to any one of the first to fourth aspects, the punched metal and the metal wire woven metal mesh are each formed of a single layer. There is a feature.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a filtration filter 10 according to a first embodiment of the present invention (corresponding to claims 1, 2, 4, and 5). The filtration filter 10 according to the first embodiment includes an annular punched metal 20 and a metal wire woven metal net 30 arranged on the inner peripheral side of the annular punched metal 20.

Here, the annular punching metal 20 is
For example, SUS304 having a plate thickness of 0.4 mm is provided with a hole diameter φ0.
Many openings of 5 mm are formed at a hole pitch of 1 mm. Then, the length and height are determined according to the inner diameter and the inner height of the chamber to be applied, cut with scissors, and the joined portion is formed into a ring shape by spot welding 21 (see FIG. 2).

The metal wire woven metal net 30 is made of a knitted woven metal net formed body 31. Here, as the knitted wire netting molded body 31, for example, SUS304 having a wire diameter of 0.5 mm is used. As shown in FIGS. 3 and 4, for example, as shown in FIGS.
05a; weight 70g) 31a is prepared, the knitted woven bag 31b which is folded twice from both ends and overlapped into three layers is put in the forming area 45 of the forming jig 40, and compression-formed by the punch 47 pressed by a press. It is formed by doing.

As shown in FIG. 3, the molding jig 40 includes a stand 41 having an annular projection 42, and cylindrical bodies 43, 44 attached to the front and rear of the annular projection 42 of the stand 41.
A molding region 45 formed between the two cylindrical bodies 43 and 44;
The spacer 4 attached to the opening end of the molding area 45
6 and a punch 47 pressed into the molding area 45.

In the present embodiment, the knitted wire mesh forming body 31 cools the combustion product gas and collects large residual particles. Since the perforated metal 20 has a small effective area for gas passage, the resistance of the entire filter is increased and the pressure is easily maintained. In addition, the opening area of the diffuser of the gas generator to be applied determines the total area of the gas passing through the punching metal 20, and the adjustment of the opening area of the diffuser makes it possible to adjust the filter resistance in a wide range.

Next, the filtration filter 1 according to the first embodiment
The result of an experiment performed by attaching 0 to the gas generator will be described. FIG. 5 shows a gas generator 50 in which the filtration filter 10 according to the first embodiment is arranged. In the gas generator 50, an ignition section (igniter 54 a and ignition agent 54 a) is provided at the center of a chamber 51 having a diffuser (gas discharge hole) 52 formed on the outer peripheral wall.
b) 54 is provided, and the ignition part 54 and the combustion chamber 56 are partitioned by the first partition member 55.

Then, a gap 57 is provided between the diffuser 52 and the filter 10, and the filter 10 is
It is arranged on the diffuser 52 side. This filtration filter 10
A gas generating agent 58 is charged into a combustion chamber 56 formed of a space between the gas generating agent 58 and the first partition member 55. Here, the chamber 51 is formed by combining a cup 51a and a cup 51b provided with a diffuser 52.

The first partitioning member 55 is formed by a bottomed cylindrical body having a nozzle 55a on the side wall. Inside the first partitioning member 55, a space is formed in which the igniter 54b can be loaded and the igniter 54a can be attached. Further, the cup 51a of the combustion chamber 56
A cushion material 53 is arranged on the side. As the gas generating agent 58, a gas generating composition (hereinafter, GAT) produced by mixing oxidizing agent and the like with guanylaminotetrazole as a base was used.

The operation of the gas generator 50 thus configured will be described. When the igniter 54a is operated to burn the gas generating agent 58, the generated combustion gas is cooled by the filter 10, the solid residue is collected by the filter 10, and the filtered combustion product is diffused. 52
From the gas generator 50.

From this experiment, it can be seen that in the case of a gas generating agent (GAT) which is relatively easy to burn and easily traps residues, the structure of the gas generator 50 can be simplified and the filtration filter 10 can also be simplified. Was. In addition, such a configuration is considered to be advantageous for cooling the combustion product gas and collecting solid residues because the cross-sectional area of the gas passing through the filtration filter 10 is large.

Further, the combustor pressure (the internal pressure of the combustion chamber 56) is controlled only by the opening area of the diffuser 52, and the gas generating agent 58 is sufficiently burned within a certain period of time.
It was found that the tank pressure could reach the maximum value around 70 ms. FIG. 6 is a graph showing the relationship between the passage of time after ignition of the gas generator 50 shown in FIG. 5 and the 60-liter tank pressure output.

According to the gas generator 50, it was confirmed that an S-shaped curve tank output was realized. FIG.
FIG. 8 shows a filtration filter 10 according to the second embodiment of the present invention.
A (corresponding to claim 1, claim 3, claim 4, or claim 5).

A filtration filter 10A according to the second embodiment
Is constituted by an annular punching metal 20A and a metal wire woven metal net 30A arranged on the inner peripheral side of the annular punching metal 20A. Here, the annular punching metal 20A is made of, for example, SUS3 having a thickness of 0.4 mm.
04, a large number of openings with a hole diameter of φ0.5mm have a hole pitch of 1m
m.

Then, the length and height are determined according to the inner diameter and inner height of the chamber to be applied, cut with scissors, and the joint is spot-welded 21A to form a ring (see FIG. 8). The metal wire woven wire mesh 30A is a twill woven wire mesh 3
2. Tatami woven wire mesh 33 and knitted woven wire mesh formed body 31
A.

Here, the twill-woven wire mesh 32 uses, for example, a wire diameter φ0.19 / φ0.14 and a mesh 40/400, and has a length and height corresponding to the inner diameter and internal height of the chamber to be applied. Decided and cut with scissors to predetermined length and height. The tatami woven wire mesh 33 has, for example, a reference wire diameter φ
Using 0.315 mm (vertical line and horizontal line) and standard dimension of opening of 1.12 mm, determine the length and height according to the inside diameter and internal height of the chamber to be applied, and cut it with scissors to a predetermined length , Height.

As the knitted wire mesh formed body 31A, for example, SUS304 having a wire diameter of 0.5 mm is used. The knitted wire mesh forming body 31A is formed in the same manner as the knitted wire mesh forming article 31 in the first embodiment. In the filter 10A according to the present embodiment, the knitted wire mesh formed body 31A cools the combustion product gas and collects large residual particles.

The hot combustion product gas from the combustor nozzle of the chamber to which it is applied is firstly knitted and woven
(Wire diameter 0.5 mm) flows into 31A. There, the combustion product gas is cooled, and the residual particles are collected by collision with the knitting wire.

Further, in the portion near the combustor nozzle, the knitted wire mesh forming body 31A is completely clogged with the residual particles, so that not only large particles but also small particles are stopped by adhesion. Next, since the tatami woven wire mesh 33 is a wire mesh having a high heat resistance and a large wire diameter, the twill woven wire mesh which is weak to heat is protected from the inflow of hot combustion product gas immediately after passing through the knitted woven wire mesh formed body 31A. .

After the combustion gas has passed through the knitted wire mesh forming body 31A, it passes through the wire mesh layer. In order to collect small fine particles, a twill woven wire mesh 32 was provided outside the knitted wire mesh formed body 31A. If the flow of combustion generated gas that has not yet been sufficiently cooled only by the knitted wire mesh forming body 31A directly hits the weak heat resistant twill wire mesh 32, damage to the twill wire mesh 32 cannot be avoided.

Therefore, in order to protect the twill woven wire mesh 32 from the hot combustion product gas flow, a tatami woven wire mesh 33 (wire diameter φ0) having a relatively high heat resistance is provided between the twill woven wire mesh 32 and the knitted woven wire mesh formed body 31A. .3 mm). Twill wire mesh 3
2 collects fine residue particles. Before the flow of combustion product gas passes through the twill wire mesh 32, many small residue particles are included.

The twill wire mesh 32 can serve to cleanly filter the combustion product gas. From the results of many experiments, it was found that the twill wire mesh 32 can sufficiently collect the residual fine particles as long as there is no damage due to heat and pressure. The punching metal 20A prevents damage to the twill wire mesh 32 due to high pressure.

In order to prevent the twill woven wire mesh 32 from being blown out of the diffuser at a high pressure, a punching metal 20A is provided between the twill woven wire mesh 32 and the diffuser. Since a large number of holes having a diameter of 0.5 mm are formed evenly on the punching metal 20A, concentration of the flow can be prevented when the gas passes through the twill woven wire mesh 32.
In order to sufficiently burn the gas generating agent within a certain time, it is necessary to maintain the combustion pressure by a filter.

Particularly, in the case of a gas generating agent which is difficult to burn, it is essential to maintain the combustion pressure by a filter in order to maintain a high combustion speed. The punching metal 20A increases the resistance of the entire filter because the effective area of gas passage is small,
It is easier to hold pressure. Further, the opening area of the diffuser of the gas generator to be applied is limited to that of the punching metal 20A.
In this case, the total area of the gas passage is determined, and the filter resistance can be adjusted in a wide range by adjusting the diffuser opening area.

In a test conducted by the present inventor, using such a combination of filters, the pressure holding capacity required before and after the opening area of φ6.5 mm × 16 diffusers, which is easy to process, against a gas generating agent which is difficult to burn. Was achieved, and the problem of excessively narrowing the diffuser was solved. Also,
When the filter and the combination of these simple substances were changed in the layer and combination of each simple substance, the following was found.

This can be easily realized by changing the amount of the knitted woven wire mesh formed body 31A to be filled in order to adjust the temperature of the exhaust gas in the tank. In addition, the resistance of the entire filter is hardly changed only by adjusting the amount of the knitted wire mesh forming body 31A. This can be realized by simply increasing the number of turns of the twill wire mesh 32 in order to improve the collection rate of the solid residue.

However, in order to keep the resistance of the filter constant when adjusting the number of turns of the twill wire mesh 32, it is necessary to appropriately adjust the opening area of the diffuser. If the non-azide gas generating agent has relatively good ignitability, fast burning rate (decomposition rate), and easy to collect residues, the initial pressure is maintained by the combustion chamber nozzle, and the residue is collected by installing a twill wire mesh. This eliminates the necessity of gathering, and makes it possible to adopt a gas generator structure with a relatively simple configuration of a metal wire woven wire mesh and a punched metal, for example, a relatively simple configuration of a knitted woven wire mesh formed body and a punched metal.

Next, the filtration filter 1 according to the second embodiment
The result of an experiment in which OA was attached to a gas generator will be described. FIG. 9 shows a filtration filter 10A according to the second embodiment.
Shows a gas generator 60 in which is disposed. In the gas generator 60, an igniter (igniter 62 a and igniter 62 b) 62 is disposed at the center of a chamber 61 having a diffuser (gas discharge hole) 63 formed on the outer peripheral wall. The combustion chamber 65 is partitioned, and the combustion chamber 65 and the filter chamber 66 are partitioned by the cup 61b. Filter room 66
Inside, a filtration filter 10A is arranged. Also,
A gas generating agent 68 is loaded in the combustion chamber 65. Further, between the combustion chamber 65 and the combustor nozzle 67,
A separator 70 is arranged via a combustor nozzle closure 71.

Here, the chamber 61 includes a cup 61a.
And a cup 61b provided with a diffuser 63 and a combustor nozzle 67, and a lid 6 for covering an opening of the cup 61b.
1c. The first partition member 64 is formed by a bottomed cylindrical body provided with a nozzle 64a on a side wall. Inside the first partition member 64, a space is formed in which the igniter 62b can be loaded and the igniter 62a can be attached.

A cushion member 69 is provided on the side of the lid 61c of the combustion chamber 65. Further, as the gas generating agent 58, a gas generating composition (hereinafter referred to as BC) manufactured by mixing biscarbamoylhydrazine as a base and mixing it with an oxidizing agent and the like.
H) was used.

The operation of the gas generator 60 thus configured will be described. When the igniter 62a is operated to burn the gas generating agent 65, the generated combustion gas flows from the combustor nozzle 67 to the filtration filter 10A, is cooled and filtered, and then is discharged from the diffuser 63 to the outside of the gas generator 60. Was discharged. From this experiment, it is possible to simplify the structure of the gas generator 60 even in the case of a relatively hardly burnable gas generating agent (BCH), but the configuration of the filter 10A is the same as that of the filter 10 of the first embodiment. It has been found that it is necessary to further wind and combine a metal wire woven wire mesh (eg, a tatami woven wire mesh, a twill woven wire mesh).

The gas generator 60 will be further described. When the combustion product gas flows from the combustor nozzle 67 into the filter chamber 66, the outflow of gas from the combustion chamber 65 is controlled by the combustor nozzle 67, so that the initial rise of the combustor pressure (the internal pressure of the combustion chamber 65) is fast, The ignition and combustion of the generator 68 are promoted.

In the tests conducted by the present inventors, the peak value of the combustor pressure rise is controlled mainly by the opening area of the combustor nozzle 67 for maintaining the initial pressure, and the pressure drop rate after passing the peak value is mainly Filter 10
It is determined by the resistance of A. Non-flammable gas generating agent (BC
H), the rate of decrease of the combustor pressure is
8 has an important effect on the combustion process.

If the combustor pressure drops too fast, the combustion pressure of the gas generating agent 68 decreases because the combustion pressure is not maintained, and the peak value of the tank pressure output is greatly delayed. Therefore, non-flammable gas generating agent (BCH)
On the other hand, the rate of decrease in the combustor pressure is controlled by adjusting the resistance of the filtration filter 10A.
It is thought to play an important role in promoting combustion of coal.

FIG. 10 is a graph showing the relationship between the passage of time after ignition of the gas generator 60 shown in FIG. 9 and the output of the 60-liter tank pressure. Even a gas generator (BCH) that is difficult to burn due to the resistance adjustment of the filtration filter 10A can be sufficiently burned within a certain period of time, and an S-shaped tank output can be realized.

FIG. 11 shows a comparative example 1 in which a filtration filter 81 composed of a single knitted woven wire mesh is disposed in place of the filtration filter 10A of the gas generator 60 shown in FIG.
1 shows a gas generator 80 according to the first embodiment. In Comparative Example 1, the arrangement of the filtration filter 81 in the gas generator 80 was designed to prevent the filter from being damaged by the concentration of the combustion product gas flow when the combustion product gas passes through the diffuser 63, so that the filter chamber was not used. It is necessary to provide a space 82 above the 66.

In the gas generator 80 shown in FIG. 11, since the combustion product gas is discharged into the tank only after breaking the diffuser closure 70, the rise of the tank pressure is slightly delayed. FIG. 12 shows a method of mixing a knitted fabric having a small wire diameter into the upper part of a knitted wire mesh formed body having a large wire diameter in place of the filtration filter 10A of the gas generator 60 shown in FIG.
7 shows a gas generator 90 according to Comparative Example 2 in which a filtration filter 91 adopting a structure that is molded together is arranged.

As shown in FIG. 13, the filter 91 is formed by folding a metal wire woven wire mesh body 91a mixed and integrated as shown in FIG. It is formed by being put in the forming area 45 of the forming jig 40 and compression-formed by a punch 47 pressed by a press. In Comparative Example 2, basically, as in Comparative Example 1, in the gas generator 90, the arrangement of the filtration filter 91 is such that when the combustion product gas passes through the diffuser 63, the concentration of the combustion product gas flow increases. The space 9 is located above the filter chamber 65 in order to prevent the
2 must be provided.

FIG. 14 is a graph showing the relationship between the time elapsed after ignition of the gas generators 80 and 90 shown in FIGS. 11 and 12 and the 60-liter tank pressure output. As compared with the result of the gas generator 60, the pressure of the gas generators 80 and 90 did not form an S-shaped curve with a gradual rise in pressure. This is considered to be due to the fact that in the case of a filter using only a single knitted woven wire mesh formed body (including a mixed type with a thin knitted cloth), the pressure holding ability is reduced, and the arrival time of the tank pressure output peak value is slow. .

Therefore, as shown in the filter 10 of FIG. 1 and the filter 10A of FIG.
The use of a combination filter of (20A) and the metal wire woven metal mesh body 30 (30A) enhances the pressure holding ability, and supports that the combustion of a non-flammable gas generating agent can be promoted. In addition, various adjustments regarding the system were performed. However, in Comparative Example 1 and Comparative Example 2, it was difficult to realize the tank pressure output of the S-shaped curve, and the gas cooling was insufficient. Next, the measurement results of the solid residue amount in the tank and the gas temperature are shown in the table below.

[Table 1] As is clear from Table 1, the amount of the solid residue in the combustion chamber is extremely small, ie, 1/4 when comparing the gas generator 50 (Example 1) using the filtration filter 10 with Comparative Example 1. Further, the gas generator 60 using the filter 10A is used.
Comparing (Example 2) and Comparative Example 2, the number is extremely reduced to １ ／. Further, the gas temperature was also able to be suppressed to 300 ° C. or less in Examples 1 and 2, but in Comparative Examples 1 and 2.
In No. 2, the temperature could not be lowered to 300 ° C. or lower.

[0062]

As described above, the filtration filter of the present invention cools the combustion product gas, collects solid residues (fine and large particles), supplies the crane-produced gas into the airbag, and supplies the air to the airbag. The bag can be deployed.

The temperature of the exhaust gas can be freely adjusted within the range of 250 ° C. to 350 ° C. by adjusting the weight of the knitted woven wire mesh formed body. Also, in order to improve the residue collection rate, the twill wire mesh may be adjusted.
For example, by increasing the number of turns of the twill wire mesh, the residue collection rate can be increased.

[Brief description of the drawings]

FIG. 1 shows a filtration filter 10 according to a first embodiment of the present invention.
FIG. 2 is a perspective view in which a part of is opened.

FIG. 2 is a schematic diagram of an assembling process of the filtration filter 10 of FIG.

FIG. 3 is a schematic view of a manufacturing process of a knitted woven wire mesh formed body.

FIG. 4 is an assembly view of a device for manufacturing a knitted wire netting molded product.

FIG. 5 is a sectional view of a gas generator incorporating the filtration filter 10 of FIG.

FIG. 6 is a graph showing the output of the gas generator of FIG. 5 to a 60 liter tank.

FIG. 7 is a filtration filter 10 according to a second embodiment of the present invention.
FIG. 2 is a perspective view in which a part of A is cut open.

8 is a schematic diagram of an assembling process of the filtration filter 10A of FIG.

FIG. 9 is a cross-sectional view of a gas generator incorporating the filtration filter 10A of FIG.

FIG. 10 is a graph showing the output of the gas generator of FIG. 9 to a 60 liter tank.

FIG. 11 is a sectional view of a gas generator of Comparative Example 1.

FIG. 12 is a cross-sectional view of a gas generator of Comparative Example 2.

FIG. 13 is a schematic diagram of a manufacturing process of a knitted woven wire mesh molded article mixed with a thin knitting used in the gas generator of Comparative Example 2.

FIG. 14 is a graph showing the output of a gas generator of Comparative Examples 1 and 2 to a 60-liter tank.

[Explanation of symbols]

 10, 10A Filtration filter 20, 20A Punched metal 30, 30A Metal wire woven wire mesh 31, 31A Knitted woven wire mesh molded product 32 Twill woven wire mesh 33 Tatami woven wire mesh 40 Molding jig 50, 60 Gas generator

Continued on the front page F term (reference) 3D054 DD11 DD18 FF20 4D019 AA01 BA02 BB02 BB10 CA03 CB04 4G068 DA08 DB12 DC01 DC05

Claims (5)

[Claims] 1. An airbag gas generator comprising: an annular punching metal having a large number of apertures; and an annular metal wire woven metal mesh disposed on the inner peripheral side of the annular punching metal. Vessel filtration filter. 2. The filter for an airbag gas generator according to claim 1, wherein the metal wire woven wire mesh is a knitted wire mesh. 3. The filter for an airbag gas generator according to claim 1, wherein the metal wire woven wire mesh body is a combination of a knitted woven wire mesh formed body, a tatami woven wire mesh and a twill woven wire mesh. . 4. The filter for an airbag gas generator according to claim 1, wherein the perforated metal and the metal wire woven metal mesh are made of stainless steel. 5. The filter for an airbag gas generator according to claim 1, wherein each of the perforated metal and the metal wire woven metal mesh is a single layer.