JPH051046B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a gas generator used for inflating air bags and buoyancy generating bags to protect occupants in the event of a vehicle collision, for emergency opening/closing of valves, for emergency seat injection, etc. The present invention relates to a method for manufacturing a filter.

[Prior Art] As this type of gas generator, a system that uses high-temperature gas generated by burning gunpowder is widely adopted. It is necessary to use a filter to collect the components. As this filter, for example, as disclosed in Japanese Patent Application Laid-Open No. 51-60333, a cooling chamber filled with straight metal wires or metal rods, or a stainless steel wire mesh (plain weave product) placed inside the casing. Laminated multiple sheets cut to size, steel wool,
Various materials are used, including metal, ceramic foam, and metal baffle plates.

[Problem to be solved by the invention]

However, among the above-mentioned filters, the straight metal wire or metal rod has no elasticity, so a gap is created between it and the casing, allowing gas to pass through.
Another disadvantage is 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 above-mentioned shot pass, and loading is time-consuming because 20 to 300 meshes are stacked alternately.
Furthermore, steel wool is easily eroded by high-temperature gas and is expensive; foamed materials have no elasticity, poor breathability, and are expensive; baffle plates have a complicated structure, require large equipment, and are not effective at capturing harmful products. It had various drawbacks, including inferior performance.

This invention solves the above-mentioned conventional drawbacks,
The object of the present invention is to provide a manufacturing method that can manufacture a small and useful filter for a gas generator through a simple process, which can be easily attached to a gas generator, and can prevent gas short passes, melting, and deterioration of air permeability. .

[Means to solve the problem]

However, the filter manufacturing method of the first invention of this application involves bending a heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm into a wavy or coiled shape, and feeding the obtained bent line material into an annular space of a mold. This method of manufacturing a filter for a gas generator is characterized in that the filters are laminated in an annular shape and then compression molded into an annular shape.

Further, the method for manufacturing a filter according to the second invention of this application involves bending a heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm into a wave or coil shape, and feeding the obtained bent line material into an annular space of a mold. After laminating them in an annular shape, they are compression-molded into an annular shape to form a primary molded product, a fastening material is wrapped around the cross section of this primary molded product, and then this wrapped primary molded product is further compression-molded into an annular shape. This is a method for manufacturing a filter for a gas generator, characterized by the following.

Further, the method for manufacturing a filter according to the third invention of this application includes bending a heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm into a wavy or coiled shape, and feeding the obtained bent line material into an annular space of a mold. This method of manufacturing a filter for a gas generator is characterized in that the filters are laminated in an annular shape, and then compression molded into an annular shape to form a plurality of grooves extending in the axial direction on the outer periphery.

In the present invention, various heat-resistant steel wires such as stainless steel wire, nickel alloy steel wire, and cobalt alloy steel wire can be used as the heat-resistant steel wire. If the wire diameter of this heat-resistant steel wire is less than 0.1 mm, there is a risk of melting damage, and if it exceeds 1.5 mm, the processing resistance during bending and compression molding will be excessive, and the gap for gas flow will be excessive.
This is not preferred because the gas cooling effect and harmful component trapping effect are poor. As this heat-resistant steel wire, a long wire rod drawn through a normal die can be used, but it is also possible to use a rotating water-cooled disk that scrapes off a small amount of molten steel by bringing it into contact with the surface of the molten steel. It is preferable to use a short wire rod with a length of about 50 to 300 mm, which is produced by a method called melt extraction method in which the wire rod is accumulated laterally, since the material cost is low.

In the present invention, when bending a heat-resistant steel wire into a wavy shape, a sine wave or a similar curved wave shape,
Alternatively, it can be bent into various waveforms such as sawtooth waves and rectangular waveforms, such as bent straight waves.As shown in Figure 3, the pitch P is 5 to 10 mm and the wave height H is 3 to 6 mm. It is particularly preferable to bend the material into a wavy shape because the gap between the lines of the compression-molded product does not become too large and the material is well integrated by moderate intertwining. In addition, this wavy bending process can be performed by bending the wire rod only once to create a wavy bending process (plane wave process) in only one direction (for example, front-to-back direction), or by bending the wire rod in another direction (for example, If the bent line material is bent into a wave shape in multiple directions (stereo wave processing) by bending it multiple times in different bending directions, such as bending it into a wave shape in the left and right direction, the bent line material will be easily wound It is particularly preferable because it is easy to get entangled during the compression process, has less deformation, has good dimensional accuracy, has uniform internal gaps, and has less directionality. When performing wavy bending multiple times in this way, it is best to change the pitch by making the bending pitch in the subsequent process smaller than the bending pitch in the previous process.If the pitches are the same or similar, the wire rod This is not preferable because it becomes twisted and makes it difficult to perform the bending process in the subsequent process.

In addition, when bending the heat-resistant steel wire into a coil shape in this invention, if the pitch is 1 to 5 mm and the pitch circle diameter is 3 to 6 mm, the gap between the wires of the compression molded product will not become excessive. Moreover, it is particularly preferable because it is well integrated by moderate entanglement.

Further, in the present invention, the bulk specific gravity of the filter can be adjusted by compression molding, but if the bulk specific gravity is less than 1, the filter becomes bulky and large, and if the bulk specific gravity exceeds 3, the ventilation resistance becomes excessive, which is not preferable.

[Effect]

In the method for manufacturing a filter for a gas generator of the present invention, the heat-resistant steel wire is directly fed into the annular space of the mold after being bent and compression-molded into an annular shape, so the process is simple and the equipment cost is low. The filter obtained by the annular compression molding in the final process is a compression molded product of bending line materials, so it has elasticity and adheres closely to the inner wall surface of the casing when attached to the casing, and the bending line members are intertwined with each other and integrated. turned into
It does not lose its shape and is easy to handle.

Furthermore, according to the manufacturing method of the second invention, after the fastening material is wrapped around the primary molded product, it is further compressed into an annular shape. Even when a bent wire member is used, the ends of the wire are prevented from protruding outward, and a filter that is less likely to lose its shape and is easier to handle can be obtained.

Further, according to the manufacturing method of the third invention, an annular filter having a plurality of grooves extending in the axial direction on the outer periphery can be obtained by only a compression molding process without laborious manual work, and the grooves are Because it is formed by local compression, it prevents the molded product from unraveling, and even when using short bending line materials, it suppresses the wire ends from protruding outward, creating a filter that is easier to handle with less deformation. is obtained.

〔Example〕

1 and 2 below, the first embodiment of the present invention will be described.
An example will be explained.

First, a stainless steel wire (heat-resistant steel wire) 1 with a wire diameter of 0.4 mm and a length of 50 to 100 mm manufactured by the melt extraction method is connected to a gear 2 that meshes with a clearance.
Bending it in the left and right direction through the space between 2 and creating a pitch of 7.
After forming the primary bending line member 3a with a pitch of 3.4 mm and a wave height of 4 mm, the primary bending line member 3a is further moved in the front and back direction by gears 4, 4 arranged on the lower stage side and having an axis perpendicular to the gear 2. The bending process was performed to obtain a bent line material 3 which was bent in a wavy manner in two directions. [FIG. 1a] This bending line material 3 is supplied into the annular space 7d of the lower mold 7 of the mold consisting of the upper mold 6 and the lower mold 7 [FIG. 1 b] An annular filter 9 having a bulk specific gravity of 1.5 was obtained by compression molding. [Figures c and d] The upper mold 6 has a cylindrical shape with holes, and the lower mold 7 has a cylindrical outer mold 7a,
It consists of a rod-shaped inner mold 7b and a perforated disk-shaped bottom plate 7c that can be raised and lowered.

In the obtained filter 9, the bending members 3 were sufficiently intertwined, the filter did not easily lose its shape, the dimensional accuracy was good, and the gaps between each part were more uniform and less directional.

The filter 9 is press-fitted into the annular cooling filtration chamber 11a of the casing 11 of the gas generator 10, and a cap 12 is attached thereto. Since the filter 9 has elasticity and is integrally molded so that it does not lose its shape, it can be easily loaded into the casing 11 with one touch. When the gas generating agent 14 loaded in the combustion chamber 13 is ignited by the igniter 15, the gas generating agent 14 explodes and burns to generate high temperature gas, which passes through the filter 9 through the vent hole 16. After cooling and collection of harmful products, the gas is ejected from the gas ejection port 17 and supplied to the gas utilization side such as an air bag.

Next, FIG. 4 shows a second embodiment of the present invention, in which the wire diameter was manufactured by the melt extraction method.
Gears 2 and 2 mesh with a stainless steel wire (heat-resistant steel wire) 21 with a clearance of 0.25 mm and a length of 50 to 100 mm.
Bending it only in the left and right direction through the gap, the pitch is 7.
A bent line material 22 with a wave height of 4 mm and a wave height of 4 mm was obtained. [FIG. 4a] This bent line material 22 is supplied into the annular space 7d of the lower mold 7 to form a laminated filling layer 8 as in the previous embodiment [FIG. 4b], and then the upper mold 6 and the lower mold are 7 to obtain an annular primary molded product 24 having a height H greater than that of the final product, the filter 26.
[Figures c and d] Next, several separately prepared bent line members are wrapped around the cross section of the primary molded product 24 as a fastening member 25 to prevent it from unraveling. [Figure d] This rolled primary molded product was further compression-molded using an upper die 6 and a lower die 7 [Figure e] to obtain an annular filter 26 having a bulk specific gravity of 1.5. [FIG. f] In the obtained filter 26, the fastening material 25
surrounds the bending line material 22 to prevent it from unraveling, and also suppresses the wire ends of the short bending line material 22 from protruding outward, making it difficult to lose its shape.
It is also easy to handle.

Next, FIGS. 5 to 7 show a third embodiment of the present invention, in which the same stainless steel wire 21 as in the second embodiment is subjected to the same bending process [FIG. 5a] and the lower die. 7 [FIG. 7b], and compression molding is performed on the obtained laminated packed layer 8 using a mold in the same manner as in the second embodiment to form an annular primary molded product 24.
And so. [C and d in the same figure] Next, as shown in FIG. 5 e, FIG. 6, and FIG. 6)
An outer mold 42a with a protrusion 41 protruding from it, a rod-shaped inner mold 42b, and the outer mold 42a and the inner mold 42b.
a lower die 42 consisting of a bottom plate 42c that fits into the bottom plate 42c and can be raised and lowered; and a cylindrical body with a hole in which a groove 43 that fits into the protrusion 41 is formed on the outer peripheral surface that fits into the inner wall surface 40. using the upper die 44 of the primary molded product 2.
4 compression molding was performed. [Fig. 5e] That is, the primary molded product 24 is charged into the upper part of the lower mold 42,
The upper mold 44 is pressed down to push the primary molded product 24 downward and compress it in the axial direction, and the outer periphery of the primary molded product 24 is locally compressed by the protrusions 41 so that six axially extending rods are formed on the outer periphery. A filter 30 having grooves 31 was obtained. [Illustrated view f] In this filter 30, the groove 31 formed on the outer periphery prevents the bent line material 22 from unraveling, and also suppresses the wire end of the short bent line material 22 from protruding outward. It is durable, does not lose its shape, and is easy to handle.

This invention is not limited to each of the above embodiments. For example, in each of the above embodiments, the laminated filling layer 8
Although the annular compression molding was carried out by compression only in the axial direction (vertical direction), compression may be performed in the radial direction as well as in the axial direction. Also, groove 3
1, the entire circumference may be compressed in the radial direction at the same time, or the groove 31 may be formed by compression molding using another type of mold, such as pressing in the radial direction with a claw-shaped mold. It may also be formed. Furthermore, in the third embodiment, the groove 31 is formed by locally compressing the outer circumference of the primary molded product 24 obtained by compression molding the laminated filling layer 8. After being directly supplied into the annular space and laminated and filled into the lower mold 42, compression molding is performed using the lower mold 42 and the upper mold 44 to form a concave groove 31 on the outer periphery.
Alternatively, an annular filter may be obtained, in which case the primary forming step is omitted and the process is simplified. Also, the fastening material 2 to be wrapped around the primary molded product.
5, a straight wire rod or a cylindrical wire mesh 50 as shown in FIG. 8 may be used, and this may be wrapped one or more times around the annular portion of the primary molded product 51. Furthermore, this invention
The present invention can also be applied to a method of manufacturing a filter for an axial flow type gas generator in which high-temperature gas flows in the axial direction of an annular body.

〔Effect of the invention〕

As explained above, according to the present invention, a small and useful filter for a gas generator, which is easy to attach to a gas generator and can prevent gas short passes, melting and deterioration of air permeability, can be produced through a simple process. The resulting filter can be widely used in gas generators for various purposes.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the manufacturing process of a filter showing a first embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of a gas generator showing how the filter is used, and Fig. 3 is a diagram showing the bending line material used in the invention. Drawing showing waveforms, 4th
FIG. 5 is a manufacturing process explanatory diagram showing a second embodiment of the present invention, FIG. 5 is a manufacturing process explanatory diagram showing a third embodiment of the invention, FIG.
FIG. 7 is a sectional view taken along the line B-B, and FIG. 8 is a longitudinal sectional view showing another embodiment of the fastening material according to the present invention. DESCRIPTION OF SYMBOLS 1...Stainless steel wire, 2...Gear, 3...Bending line member, 3a...Primary bending line member, 4...Gear, 5...Laminated body, 6...Upper die, 7...Lower die, 7d...Annular space, 8...
Laminated packed layer, 9... Filter, 21... Stainless steel wire, 22... Bent line material, 23... Laminated body, 24... Primary molded product, 25... Fastening material, 26... Filter, 30...
Filter, 31... Concave groove, 41... Projection, 42... Lower die, 44... Upper die, 50... Wire mesh, 51... Primary molded product.

Claims (1)

[Claims] 1. A heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm is bent into a wavy or coiled shape, and the obtained bent line material is supplied into the annular space of a mold and laminated in an annular shape. A method for manufacturing a filter for a gas generator, characterized by compression molding. 2 Heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm is bent into a wavy or coiled shape, the resulting bending material is fed into the annular space of a mold, stacked in an annular shape, and then compressed into an annular shape for primary forming. A method for manufacturing a filter for a gas generator, comprising: wrapping a fastening material around the cross section of the primary molded product; and then compression molding the wrapped primary molded product into an annular shape. 3 Heat-resistant steel wire with a wire diameter of 0.1 to 1.5 mm is bent into a wavy or coiled shape, the resulting bent material is supplied into the annular space of the mold, stacked in an annular shape, and then compressed into an annular shape to form the outer periphery. A method for manufacturing a filter for a gas generator, comprising forming a plurality of grooves extending in the axial direction.