JPH01293112A - Filter for gas generator and its production - Google Patents

Abstract

PURPOSE:To facilitate the production and setting of the title filter and to enhance the performance by forming the annular thin wire layer and annular thick wire layer each having a specified wire diameter in a double structure while placing the annular thick wire layer on the gas inlet side, and compression-molding the structure to a specified bulk density. CONSTITUTION:A cylinder 4 made of a knitted wire mesh formed from a stainless steel wire having 0.1-0.4mm diameter is allowed to pierce an annular body 8 made of a plane-woven wire mesh formed from a stainless steel wire having 0.50-2mm diameter, and a part 4a of the cylinder 4 is spooled on the annular body 8. The remainder 4b of the cylinder 4 is wound into a bag, and the bag is positioned on the outer periphery of the annular body 8. The product is compression-molded in a metallic mold by a press to 1.0-3.0 bulk density, and a compact double-structure annular filter 10 having a good ventilating resistance is obtained. The filter 10 is easily set in a gas generator, and the short-circuiting of the gas and erosion can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a gas generator used for inflating airbags and buoyancy generation bags that protect occupants in the event of a vehicle collision, for emergency opening/closing of pulp, for emergency seat injection, etc. Regarding the filter and the manufacturing method of this filter! do.

[Conventional technology]

As this type of gas generator, a method that uses high-temperature gas generated by burning gunpowder is widely adopted, but in order to avoid damage to bags, etc., the gas must be cooled! II and for the collection of harmful components in the gas it is necessary to use a filter. As this filter, for example, JP-A-51-6
As disclosed in Publication No. 033, a cooling chamber filled with straight metal wires or metal rods, or a stack of stainless steel wire mesh (plain weave) cut to match the inner diameter of the casing. A variety of materials are used, including steel wool, metal and ceramic foam materials, and metal baffles.

[Problem to be solved by the invention]

However, among the above-mentioned filters, the linear metal wire or metal rod has the disadvantage that it has no elasticity and thus creates a gap with the casing, causing a short gas flow, and that it takes time and effort to set up and is bulky. In addition, since the wire mesh has little elasticity, it is easy to cause the short pass mentioned above, and
Loading is time-consuming because 300 meshes are stacked alternately. Furthermore, steel wool undergoes FJ due to high temperature gas.
! Foam materials have various disadvantages, such as being easy to flutter and being expensive, foam materials have no elasticity, poor breathability, and are expensive, and baffle plates have a complicated structure, making the device large and having a poor effect on trapping harmful products. It was something that I had.

The present invention solves the above-mentioned conventional drawbacks, and provides a small and useful gas generator filter that can be easily attached to a gas generator and prevents gas leakage, melting and deterioration of air permeability. , it is an object of the present invention to provide a manufacturing method that allows this filter to be manufactured through simple steps.

[Means to solve the problem]

However, the filter of the present invention is an annular filter made of metal wrought, and includes one annular $IIIFj layer made of preferably knitted wire mesh having a wire diameter of 0.1 to 0.4 mm, and a wire wire diameter of 0.
, 5 to 2.0 mm thick annular wire layer preferably made of plain weave wire mesh, the annular thick wire layer being provided unevenly on the gas inflow side, and the bulk specific gravity of the entire two-layer structure being 1.0 to 3. ．．
This is a filter for a gas generator that is compression molded to have a diameter of 0.

Further, the first method for manufacturing the filter of the present invention is characterized in that the wire diameter is 0.
Preferably, a plain-woven wire mesh made of a metal wire of 5 to 2.0M is wound into a ring shape like a belt winding, and the wire diameter is 0.1 to 2.0M.
A cylindrical body is formed from a preferably knitted wire mesh made of metal wire of 0.4 mts, a part of this cylindrical body is passed through the annular body and wound around the annular body, and the remaining part of the cylindrical body is wrapped in a bag. Thereafter, the IKt-shaped body is compression-molded to obtain a two-layered annular filter in which the annular thick ID layer is inside the annular thin wire layer.

Further, the second method for manufacturing the 'filter of the present invention is that the wire diameter is 0.
, 5-2. A plain weave wire mesh made of OM metal wire is wound to form an annular body, a cylindrical body is formed from a preferably stockinette knitted wire mesh made of metal wire with a wire diameter of 0.1 to 0.4 mm, and this cylindrical body is wrapped in a bag. The annular bag-wrapped product obtained by this process is compression-molded together with the annular body while being fitted or laminated to the annular body, so that the annular thick wire layer is located outside (including the inner diameter side) of the annular thin wire layer. This is a method for manufacturing a filter for a gas generator, which is an annular filter with a layered structure.

In the present invention, heat-resistant metal wires such as stainless steel, nickel alloy steel, cobalt alloy steel, etc. can be used as the metal wire.

In this invention, if the wire diameter of the thin wire constituting the annular thin wire layer such as knitted knitted wire mesh is less than 0.1#, there is a risk of melting damage, and if it exceeds 0.4#, the resistance during braiding by the knitting machine will be large. This is not desirable. Furthermore, if the wire diameter of the thick wire constituting the annular thick wire layer such as Heijokin WJ is less than 0.5#, there is a risk of melting damage because it is on the gas inflow side, and if it exceeds 2m, it will become bulky and large, which is not preferable. .

In this invention, the annular thick wire layer is provided inside the annular thin wire layer and is surrounded by the annular thin wire layer and unevenly distributed on the gas inflow side, and when it is provided outside the annular thin wire layer and is provided on the gas inflow side. In some cases, they are provided unevenly on the gas inflow side adjacent to the layer.

In the former case, a small amount of the annular fIlIi1 layer is present on the gas inflow side of the annular thick line layer, and the filter with this structure is manufactured by the first manufacturing method of the present invention (claim 2).
Manufactured efficiently by In the latter case, the annular thin wire layer does not exist on the gas inflow side of the annular thick wire layer, and the filter with this structure is manufactured by the second manufacturing method of the present invention (claim 3).
Manufactured efficiently by

In addition, in this invention, the bulk specific gravity of the filter can be adjusted by compression molding.
If the bulk specific gravity is less than 3, it becomes bulky and large, and if the bulk specific gravity exceeds 3, the ventilation resistance becomes large, which is not preferable. Note that the wire mesh forming the annular thin wire layer and the annular thick wire layer is preferably made of stockinette knit for the annular thin wire layer and plain weave for the annular thick wire layer.
The wire mesh is not necessarily limited to this, and wire meshes of other weaves can of course be used.

(Function) Since the filter for a gas generator of the present invention is a compression molded product of a wire mesh, it has elasticity and adheres closely to the inner wall surface of the casing when attached to the casing, and is molded in one piece so that there is little deformation. Further, the high temperature gas is cooled to some extent as it passes through the annular thick wire layer, and a part of the harmful products in the gas are collected, and then further cooling and the remaining harmful products are collected by the annular thin wire layer. In addition to preventing the occurrence of erosion in this Iζ-shaped annular thin lQI, harmful products are collected in order from large particles by passing through the two-stage distribution gap, which prevents deterioration of air permeability due to clogging. . In addition, when the annular thick wire layer surrounds the annular thick wire layer, the annular thin wire layer holds the annular thick wire layer and the two are reliably integrated. Even if the side 112 layer were to melt due to high temperature gas,
Cooling of the gas and collection of the products by the annular thick line layer existing immediately downstream thereof are carried out without any problem. In addition, if the annular thick wire layer is outside the annular cotton A layer and adjacent to the annular thin wire layer, due to the entanglement and elasticity of each wire mesh during compression molding, both layers will be integrated into one annular layer with a two-layer structure. Retains body shape.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In Figure 1, stainless steel with a wire diameter of 0.1 to 0.4-!
A metal wire 1 manufactured by K. 1 is stockinette-knitted by a knitting machine 2 to obtain a cylindrical stockinette-knitted wire mesh 3 (FIG. 1(a)), which is cut to form a cylindrical body 4 made of stockinette-knitted wire mesh. [Figure (b)
] On the other hand, a stainless steel metal wire 5 with a wire diameter of 0.5 to 2a11 was plain woven using a #1 machine 6, a flat 11 wire mesh 7 was made into a rod [same figure (C)], and this was cut into thin strips. It is wound into a belt to form an annular body 8. [Image (d)] Next, the cylindrical body 4 is inserted into the annular body 8, and the part 4a of the cylindrical body 4 is wrapped around the annular body 8 in a bag shape, and the remaining part 4b of the cylindrical body 4 is wrapped around the annular body 8. The wrapped portion is placed in a predetermined position (in this example, the outer periphery of the annular body 8) (4r (f) in the same figure), and is pressed into the mold. Compression molding is performed to obtain a two-layered annular filter 10. [Image (g)] 11 is an annular l1IIvA layer made of knitted knitted wire mesh 3;
Reference numeral 12 denotes an annular thick wire layer made of plain-woven wire mesh 7, which is held within the annular thin wire layer 11 in a manner unevenly distributed on the inner diameter side.

The filter 10 having the above structure is press-fitted into the annular cooling filtration chamber 14a of the casing 14 of the gas generator 13, and a cap 15 is attached thereto, as shown in FIG. filter 10
Since it is integrally molded and does not lose its shape, it can be easily loaded into the casing 14 with one touch. When the gas generating agent 17 loaded in the combustion chamber 16 is ignited by the igniter 18, the gas generating agent 17 explodes and burns, generating high-temperature gas. After cooling and collecting harmful products, the gas is ejected from the gas ejection port 20 and supplied to the gas utilization side such as an airbag.

Next, FIG. 3 shows a twelfth embodiment of the present invention, in which a cylindrical body 4 is preferably made of a fine wire layer made of knitted wire mesh, and an annular body is preferably made of a thick wire layer made of plain weave wire mesh, in the same manner as in the Bamboo record embodiment. 8 to 19, as shown in FIG. 3(a), the cylindrical body 4
If the annular bag-wrapped product 21, which is individually wrapped in a bag, is fitted onto the outside of the annular body 8 and compression-molded using a press, a ring-shaped m is formed on the outside of the annular thick wire layer 12 as shown in FIG. An annular filter 22 having a two-layer structure in which the wire layer 11 is fixed is obtained.

The present invention is not limited to the above-mentioned embodiments; for example, instead of the circular knitted cylindrical body 4.

A sheet of flat knitted metal wire stockinette may be wound and made into a cylindrical shape by spot welding or the like.

Further, in the case of a filter for a gas generator in which high-temperature gas flows from the outer circumferential side to the inner circumferential side, the annular thick line layer 12 may be disposed on the outer circumferential side in each of the above embodiments.

Furthermore, in the case of a filter for an axial flow type gas generator in which high-temperature gas flows in the axial direction of the annular body, for example, as shown in FIG. 4 or FIG. 11 may be compression molded into a two-tiered stacked form.

The case where the annular Il wire layer 1 and the annular thick wire layer 12 are each made of wire mesh having one type of wire diameter has been described above, but each of these layers may be made of a plurality of types of wire mesh having different wire diameters.

[Effects of the Invention] As explained above, the filter of the present invention is a compression-molded product of wire mesh, is small and has elasticity, can be easily attached to a gas generator, and can prevent short paths of gas. Along with the circular net $! It is a useful filter that can prevent melting damage and deterioration of air permeability due to high temperature gas because it has an annular thick line layer unevenly distributed on the gas inflow side. Further, according to the filter manufacturing method of the present invention, a filter having the above-mentioned excellent characteristics can be manufactured through simple steps, and the obtained filter can be widely used in gas generators for various uses.

[Brief explanation of the drawing]

FIG. 1 shows a filter manufacturing process showing a first embodiment of the present invention. ! i! 2 is a vertical sectional view showing the filter in use, FIG. 3 is a manufacturing process explanatory diagram showing a second embodiment of the present invention, and FIGS. 4 and 5 are further embodiments of the present invention. FIG. 2 is a vertical cross-sectional view of a filter showing an example. DESCRIPTION OF SYMBOLS 1... Metal wire, 3... Knitted wire mesh, 4... Cylindrical body, 4a... Part, 4b... Remainder, 5... Metal wire, 7... Plain weave wire mesh, 8 . . . Annular body, IO .

Claims (1)

[Scope of Claims] 1. An annular filter made of metal wire, which has a wire diameter of 0.1 to
An annular thin wire layer consisting of a wire mesh of 0.4 mm and a wire diameter of 0.5~
The thick annular wire layer is provided unevenly on the gas inflow side, and is compressed so that the bulk specific gravity of the entire two-layer structure is 1.0 to 3.0. A molded gas generator filter. 2. A wire mesh made of metal wire with a wire diameter of 0.5 to 2.0 mm is wound to form an annular body, a cylindrical body is formed from a wire mesh made of metal wire with a wire diameter of 0.1 to 0.4 mm, and this cylindrical body A part of the cylindrical body is passed through the annular body and wound around the annular body, and the remaining part of the cylindrical body is wrapped in a bag, and then compression molded together with the annular body to obtain an annular two-layer structure filter. Method. 3. A wire mesh made of metal wire with a wire diameter of 0.5 to 2.0 mm is wound to form an annular body, a cylindrical body is formed from a wire mesh made of metal wire with a wire diameter of 0.1 to 0.4, and this cylindrical body A method for producing a filter for a gas generator, in which an annular bag-wrapped product obtained by bag-wrapping is compressed and molded together with the annular body in a state in which it is fitted or stacked on the annular body to obtain an annular two-layer structure filter.