JP2009190656A - Molding for filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding for a filter especially appropriate for a filter of a gas generator for an airbag with a cooling effect and a filtration effect improved by increasing a contact area with gas. <P>SOLUTION: A plane stitch material of a metal wire rod 30 having radial projecting parts 32 (recessed parts 33) stretching in a longitudinal direction on a surface of a wire rod body 31 is molded in a desired form and compression molding is conducted if necessary. As the metal wire rod 30 has projecting parts and recessed parts, a clearance structure in the molding is complicated and thus the contact area of the gas and the molding (the metal wire rod 30) when the gas moves through the molding is increased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a filter for cooling and filtering a gas containing impurities or a high-temperature gas, particularly a filter molded body suitable for a coolant filter of a gas generator used in a personnel protection device for protecting vehicle personnel from impact, The present invention relates to a gas generator for a personnel protection device having a cylindrical filter made of the filter molded body.

  As a coolant filter for a gas generator, one obtained by winding a plain weave wire or the like a plurality of times, winding a single wire material a plurality of times, or braiding a wire material into a cylindrical shape and compressing it in a mold is known. The filter is cooled when a high-temperature gas passes through it, and also collects residues contained in the gas.

  In Patent Document 1, a circular metal wire having a diameter of 0.5 mm is rolled with a filter formed by winding a single wire a plurality of times into a cylindrical body, and the cross section has a thickness of 0.30 mm and a width of 0.65 mm. The use of a rectangular shape is described.

  Patent Document 2 discloses a filter that separates blow-by gas of an internal combustion engine. The filter is formed by combining a horizontal wire and a vertical wire, and a horizontal wire having a circular cross section is used. In addition, a vertical wire having a triangular cross section is used (paragraph number 12).

JP 2001-171472 A Japanese Patent Laid-Open No. 6-146841

  This invention makes it a subject to provide the molded object for filters which can improve a cooling effect and / or the filtration effect by increasing the contact area with respect to high temperature gas, and can be applied as a filter of various uses.

  Furthermore, this invention makes it the other subject to provide the gas generator used for the personnel protection apparatus provided with the cylindrical filter which consists of the said molded object for filters as a filter for cooling and filtration.

  The invention of claim 1 is a filter molded body in which one or a plurality of metal wires are combined, and the metal wire has irregularities on the surface thereof. .

  A metal wire having a cross-sectional shape of a circle, an ellipse, a triangle, a square, a rectangle, another polygon, or the like can be used. The metal wire is preferably made of iron or stainless steel.

  The unevenness on the surface of the metal wire consists of protrusions (convex parts), depressions and grooves (concave parts) formed on the surface of the wire. The unevenness may be formed continuously in the length direction, may be formed discontinuously, or a large number of independent unevenness may be formed, but is formed continuously in the length direction. Are preferred.

The molded article for filter of the present invention is, for example,
(I) A method of producing a laminate in which a flat knitted tubular metal mesh using a metal wire is stacked in the radial direction, and compression-molding the laminate,
(II) A method for producing a flat knitted tubular wire mesh using a metal wire, and compressing the tubular wire mesh in a radial direction to form a plate wire mesh, and then using the plate wire mesh to obtain a desired shape,
(III) A method of winding a metal wire around a core many times to obtain a desired shape,
Can be manufactured.

  Since the molded body for a filter of the present invention is manufactured using a metal wire having an uneven surface, the presence of the unevenness causes an inner portion of the filter molded body to be manufactured using a metal wire having a smooth surface. The void structure is complicated and the internal surface area is increased. For this reason, when the gas passes through the filter molded body, the contact area between the metal wire and the gas is increased, and the cooling effect and / or the filtering effect (mainly the filtering effect in the case of low temperature gas) is obtained. Be improved.

The molded product for a filter of the present invention can be used as a filter for various applications after being shaped or processed into a desired shape as it is or as necessary. When used as a molded article for a filter of the present invention, for example, a bulk density of 2 to 5 g / cm ³ and a pressure loss of 0.5 to 0.7 kPa can be achieved.

  According to a second aspect of the present invention, there is provided the molded article for a filter according to the first aspect, wherein the metal wire has radial convex portions that are continuous in the length direction on the surface.

  By using a metal wire having radial protrusions that are continuous in the length direction on the surface, a molded article for a filter that is homogeneous throughout can be obtained.

  Invention of Claim 3 provides the molded object for filters of Claim 1 or 2 whose maximum diameter of the said metal wire is 0.4-0.8 mm.

  When a metal wire having such a diameter is used, a cooling effect and a filtering effect are improved particularly when used as a filter of a gas generator of a personnel protection device (airbag device or the like).

  A fourth aspect of the present invention provides a gas generator for use in a personnel protection device having a cylindrical filter comprising the filter molded body according to any one of the first to third aspects.

  Since the filter molded body of the present invention is made of a metal wire having irregularities on the surface, the internal void structure is complicated, the contact area with the gas is increased, and an excellent cooling effect for high-temperature gas And filtration effect (mainly filtration effect for low temperature gas). For this reason, when applied as a filter to a gas generator for personnel protection devices such as an air bag device, the cooling effect of the high temperature gas is good and the collection effect of the combustion residue contained in the combustion gas is also good.

<Metal wire constituting the molded article for filter>
With reference to FIG. 1, a metal wire according to an embodiment will be described. (A) is a perspective view including the edge part of a metal wire, (b) is sectional drawing of (a).

  The metal wire 30 is made of iron or stainless steel. Five protrusions (convex portions) 32 are formed on the surface of the wire main body portion 31 radially and at equal intervals in the circumferential direction, and concave portions 33 are formed between the protrusions 32. The number of protrusions 32 can be 3-8.

  Each of the five protrusions 32 is formed continuously in the length direction, and the recess 33 is a groove continuous in the length direction.

  The cross-sectional shape of the protrusion 32 is not particularly limited, and may be a shape with a rounded tip, a triangle, or the like in addition to the illustrated shape.

The maximum diameter of the metal wire 30 (L _{1 in} FIG. 1B) can be 0.4 to 0.8 mm, and the height of the protrusion 32 (L _{2 in} FIG. 1B) is 0.1 to 0.1 mm. It can be 0.3 mm.

The ratio between the height _{L 2} and wire diameter _{L 3} of the main body portion 31 of the projection _32, L 2 / _{L 3} can be approximately 0.5 to 2.

  Next, a method for manufacturing the metal wire 30 shown in FIG. 1 will be described with reference to FIGS. 2A, 2C, and 2D are process diagrams for explaining a method of manufacturing the metal wire 30, and FIG. 2B is a plan view of a mold used in the manufacturing method.

  As shown in FIG. 2A, a forming die 40 is disposed around the metal wire 30 'before processing. The mold 40 is divided into three mold members 40a, 40b, and 40c. When the respective mold members are combined, as shown in FIG. 2 (b), a peak portion 41a and a valley portion 41b are formed, and the hole shape surrounded by the three mold members 40a, 40b, 40c is shown in FIG. It becomes the same shape as the cross section of the metal wire 30 shown.

  In the state shown in FIG. 2 (a), the three mold members 40a, 40b, and 40c are pressed against the central portion of the metal wire 30 ′ before processing by mechanical means, and the state shown in FIG. 2 (c). To. At this time, the crest portion 41a formed by the mold members 40a, 40b, and 40c is in a state of being bitten into the wire 30 '.

  Subsequently, with the mold 40 fixed as shown in FIG. 2C, the wire 30 'is pulled out in the direction of the arrow as shown in FIG. 2D. Then, it is processed into the same shape as the hole shape surrounded by the three mold members 40a, 40b, and 40c shown in FIG. 2B (that is, the shape shown in FIG. 1). 2 (a) to 2 (d), in order to facilitate the forming process, taking into consideration the melting point of the material of the wire, either one of the metal wire 30 'and the forming die 40 before processing Or both may be heated.

<Filter compact using metal wire 30 and method for producing the same>
FIG. 3 is a longitudinal sectional view of the gas generator for an air bag, and a cylindrical filter 7 is disposed inside the housing 3. The cylindrical filter 7 can be manufactured by applying the methods (I) to (III) described above. This will be described in more detail below.

Method (I) Using a metal wire 30, a laminated body in which flat knitted tubular metal meshes are stacked in the radial direction by the method described in, for example, Japanese Patent Application Laid-Open No. 2001-225715 (particularly, paragraph No. 13, FIG. 7). To manufacture. Next, the laminate is compression-molded from both the radial direction and the axial direction.

Method (II) A flat knitted tubular wire mesh is manufactured using the metal wire rod 30, and the tubular wire mesh is compressed in the radial direction to form a plate wire mesh, and then the plate wire mesh is wound into a cylindrical shape. Thereafter, compression molding is performed from both the radial direction and the axial direction.

Method (III) In this method, the metal wire 30 is wound around the core material a number of times and formed into a cylindrical shape, and then the core material is pulled out. The method described in JP-A-2001-171472 can also be applied. At this time, the winding direction may be changed several times.

<Gas Generator Used for Personnel Protection Device of the Present Invention>
FIG. 3 shows a vertical cross-sectional view of a gas generator used in an airbag apparatus using a cylindrical filter made of the filter molded body of the present invention.

  In the gas generator shown in FIG. 3, a housing 3 is formed from a diffuser shell 1 and a closure shell 2, and an inner cylinder 16 is disposed in the center of the housing 3.

  A plurality of gas discharge ports 11 are arranged in the circumferential wall portion 8 of the diffuser shell 1 at equal intervals in the circumferential direction. The inner cylinder member 16 is attached to the circular portion 6 of the diffuser shell 1. The closure shell 2 has a hole 15 at the center thereof and is joined to the inner cylinder member 16.

  An outward flange 13 is formed at the opposite end of the inner cylindrical member 16 and is fixed to the circular portion 6 by welding. The inner cylinder member 16 has a through hole 24, and the through hole 24 is closed with a seal tape 22. The inner side of the inner cylinder member 16 serves as an ignition means accommodation chamber 5 for accommodating the ignition means. The ignition means includes an igniter 4 and a transfer charge 23 ignited by the igniter 4.

  The filter 7 is disposed so as to surround the inner cylinder member 16, and an annular combustion chamber 28 is formed between the filter 7 and the inner cylinder member 16. The combustion chamber 28 is filled with a pellet-shaped gas generating agent 18. The filter 7 is fixed to the flange 13 of the inner cylinder member 16 by contacting the annular portion 25 of the support member 19.

  The igniter 4 is inserted into the inner cylinder member 16 after the transfer charge 23 is filled. The caulking portion 27 is fixed to the housing 3 by caulking.

  A gap 9 is formed between the peripheral wall portion 8 of the housing and the coolant 7, and this gap 9 is a gas flow path through which the cooled and purified gas passing through the coolant 7 reaches the gas outlet 11 of the diffuser shell. Function as. Further, in order to prevent moisture from entering the housing 3 from the outside, the gas discharge port 11 is blocked by the aluminum tape 29.

  The diffuser shell 1 and the closure shell 2 are fixed by welding the overlapped flange portions 10 and 12 with the welded portion 21, the joint portion between the diffuser shell 1 and the inner cylindrical member 16, the closure shell 2 and the inner cylindrical member, respectively. This is done by welding 16 joints.

  In the gas generator of FIG. 3, when a sensor (not shown) senses an impact, the signal is sent to the igniter 4 to activate the igniter 4, and the transfer charge 23 is ignited to ignite the combustion product (high temperature). Gas and flame). This combustion product breaks the seal tape 22 and is ejected from the through hole 24 and enters the combustion chamber 28. The flame that has entered the combustion chamber 28 ignites the gas generating agent 18 and generates high-temperature and high-pressure gas. The filter 7 withstands the pressure of the combustion gas generated in the combustion chamber and allows the gas to pass while maintaining its shape, and exhibits a filtering function and a cooling function as a filter.

  The gas that has passed through the filter 7 passes through the gap 9, breaks the aluminum tape 29, passes through the gas discharge port 11, and flows into the airbag (not shown). This inflates the airbag and forms a cushion between the occupant and the rigid structure to protect the occupant from impact.

  Since the cylindrical filter 7 is made of the metal wire 30 having the radial continuous protrusions 32 (and the continuous groove 33) on the surface, compared with the one manufactured using a metal wire having a smooth surface, The presence of the continuous protrusion 32 (and the continuous groove 33) complicates the internal void structure and increases the internal surface area. For this reason, when combustion gas passes through the cylindrical filter 7, the contact area of the metal wire 30 and combustion gas will be increased, and the cooling effect and the filtration effect will be improved.

(A) is a fragmentary perspective view of a metal wire, (b) is sectional drawing of (a). (A), (c), (d) is processing explanatory drawing of a metal wire, (b) is a top view of the shaping | molding die used for a process of a metal wire. The longitudinal cross-sectional view of the gas generator for airbags using the cylindrical filter which consists of a molded object for filters.

Explanation of symbols

30 Metal wire 30
31 Wire body part 32 Protrusion (convex part)
33 Groove (concave)

Claims (4)

  A filter molded body, which is a filter molded body in which one or a plurality of metal wires are combined, and the metal wire has irregularities on the surface.   The molded body for a filter according to claim 1, wherein the metal wire has radial convex portions that are continuous in the length direction on the surface.   The filter molded body according to claim 1 or 2, wherein a maximum diameter of the metal wire is 0.4 to 0.8 mm.   The gas generator used for the personnel protection apparatus which has the cylindrical filter which consists of a molded object for filters of any one of Claims 1-3.

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