JP2014069765A - Filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a doughnut-shaped filter which can be produced inexpensively and has excellent filter performance.SOLUTION: A doughnut-shaped sheet material 1 in which a plurality of arc-shaped slits are arranged regularly in the normal and circumferential directions is used as a material. The sheet material 1 is formed into a three-dimensional doughnut-like shape having a honeycomb structure by folding the sheet material 1 along two or more lines both in the normal direction and in the circumferential direction in such a way that the plurality of the arc-shaped slits serve as openings of hexagonal cells 50. In two or more wall parts constituting the honeycomb structure, a plurality of holes 13 are provided for ventilation of the portion from the inside of the innermost peripheral cells to the outside of the outermost peripheral cells.

Description

  The present invention relates to a filter suitable for an application such as being used around a gas generating material of a disk type inflator, which is a component part of an airbag device, for example.

In the disk type inflator of the airbag device, the inflation gas is jetted around the gas generating material. In order to remove residues from such a gas, it is desirable to arrange a filter so as to cover the entire circumference around the gas generating material.
As an example for this purpose, for example, Patent Document 1 discloses a wound plate type filter in which a plate material provided with a plurality of through holes is formed in an overlapping manner. According to such a filter, the gas sequentially passes through the through-holes while colliding with the lap-wound plate portion, so that the residue in the gas can be removed by the labyrinth effect. In addition, an effect of cooling the gas can be expected.

However, since the filter according to the prior art is obtained by winding a plate material provided with a plurality of through holes, the layout of the through holes differs from that of other parts depending on the part. Such a situation is not desirable because it not only causes a bias in the collection and residue of residues but also causes a bias in the flow of gas.
As a means for solving such a problem, it can be considered that the filter has a honeycomb structure. However, it is not easy to form a filter having a honeycomb structure in a donut shape. For example, if a means for cutting a honeycomb structure into a donut shape is employed, the cost is high and wasteful. In addition, it is conceivable to form a doughnut shape by curving a band-shaped body having a honeycomb structure, but with such means, the honeycomb structure is broken.

JP2012-144072A

  The present invention has been conceived under the circumstances as described above, and it is an object of the present invention to provide a donut-shaped filter that can be manufactured at a low cost and has excellent filter performance. .

  In order to solve the above problems, the present invention takes the following technical means.

  The filter provided by the present invention uses, as a material, a donut-shaped sheet material in which a plurality of arc-shaped slits are regularly arranged in the normal direction and the circumferential direction, and the plurality of arc-shaped slits are hexagonal. The sheet material is assembled into a three-dimensional donut shape having a honeycomb structure by folding the sheet material at a plurality of locations both in the circumferential direction and the normal direction so as to form openings of cells. The plurality of constituting wall portions are provided with a plurality of hole portions for obtaining air permeability from the inner side of the innermost cell to the outer side of the outermost cell.

According to such a configuration, the following effects can be obtained.
1stly, since the filter of this invention is comprised by making a sheet | seat material into a raw material and folding this, the cost can be reduced considerably.
Secondly, since the honeycomb structure has a high shape stability and a high strength, a sheet material is used as a material, but sufficient durability can be provided. As a means for three-dimensionally assembling the sheet material, the sheet material has a donut shape, and a plurality of arc-shaped slits are regularly provided, but because the sheet material provided with such slits is used. The filter can be manufactured so as not to cause a large distortion in each part of the filter.
Third, if a honeycomb structure is employed, the filter performance can be improved. Further, it is possible to easily achieve uniform gas flow rate in the circumferential direction.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

(A) is a top view which shows an example of the sheet material used for manufacture of the filter based on this invention, (b) is Ib-Ib sectional drawing of (a). (A) is a principal part perspective view of the honeycomb structure assembled using the sheet | seat material of FIG. 1, (b) is a partially broken principal part perspective view in the middle of the assembly. (A) shows the usage example of the filter which concerns on this invention, (a) is a disassembled perspective view, (b) is principal part plane sectional drawing.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  In FIG. 3, the filter F of the present embodiment has a donut shape as a whole, and has a honeycomb structure. The filter F is used by being incorporated in a housing 80 of an inflator of an airbag device. More specifically, a cup 7 having a propellant 71 and a vent hole 70 is accommodated in the central portion of the housing 80, and a filter F is disposed around the cup 7. The thickness of the filter F may be reduced, and the two filters F may be used in an overlapping manner.

  The filter F is formed by bending the sheet material 1 shown in FIG. This sheet material 1 is made of metal and has a hollow disk shape (doughnut shape) having a circular hole 10 in the center.

  A plurality of bending lines L1 and L2 extending in the normal direction are formed on the sheet material 1 at equal angular intervals. In the drawing, a fold line L1 indicated by a broken line is a valley fold line, and a fold line L2 indicated by a continuous line is a mountain fold line. These fold lines L1 and L2 are arranged in an array in which two fold lines of the same type are alternately arranged in the circumferential direction of the sheet material 1. Note that these fold lines L1 and L2, other fold lines to be described later, the arc-shaped slit 12, and the hole 13 can be formed simultaneously when the outer shape of the sheet material 1 is punched out by pressing.

The sheet material 1 is provided with a plurality of arc-shaped slits 12 (indicated by thick lines in FIG. 1) in a regular arrangement. The plurality of arc-shaped slits 12 are provided at equal angular intervals on the circumferences C1 to C4 of a plurality of circles concentric with the sheet material 1. The radius of curvature of each arc-shaped slit 12 coincides with the arcs of the circumferences C1 to C4. Each arc-shaped slit 12 has a length corresponding to three pitches of the folding lines L1 and L2, and an interval between the arc-shaped slits 12 in the circumferential direction corresponds to one pitch of the folding lines L1 and L2. In the normal direction, the plurality of arc-shaped slits 12 are alternately displaced by one pitch of the folding lines L1 and L2, and the innermost arc-shaped slit 12 and the third row from the innermost circumference are arranged. The arc-shaped slits 12 have the same circumferential position, and the arc-shaped slits 12 in the second and fourth rows from the innermost circumference also have the same circumferential position.

  Arc-shaped bending lines T1, T2 are provided between the arc-shaped slits 12 located on the same circumference. A fold line T1 indicated by a continuous line is a mountain fold line, and a fold line T2 indicated by a broken line is a valley fold line. The plurality of holes 13 become holes for ventilation when the sheet material 1 is assembled into a donut shape.

  The sheet material 1 is assembled as a donut-shaped filter F having a honeycomb structure as shown in FIG. FIG. 5B shows the state during the assembly. When assembling such a structure, basically, the arc-shaped slit 12 is largely opened, and this arc-shaped slit 12 is used as an opening of the hexagonal cell 50 having a honeycomb structure. Specifically, the sheet material 1 may be subjected to a predetermined bending process along the above-described mountain fold line or valley fold line. In this operation, the sheet material 1 is bent in both the circumferential direction and the normal direction. In addition, the part shown with the code | symbol n2 is a folding | returning part of the sheet | seat material 1, and the part shown with the code | symbol n1 is an overlapping part of the folded parts.

  As shown in FIG. 2, the filter F is provided with a plurality of holes 13. As shown in FIG. 3B, the holes 13 are generated by the combustion of the propellant 71. In this case, after passing the gas through the innermost hexagonal cell 50 of the filter F, the traveling direction is sequentially changed toward the outermost hexagonal cell 50, and finally the housing 80 It is provided so that it can flow out to the outside almost uniformly. If the gas is passed through such a path, it is preferable for residue removal and the filter performance can be improved. It is also possible to set the gas to stay in the filter F for a relatively long time. In this case, the gas cooling performance can be enhanced.

  As described above, the filter F of the present embodiment is configured by using the sheet material 1 as a raw material and turning it back, so that the cost can be considerably reduced. Since the honeycomb structure has a high shape stability and can increase the strength, the filter F is configured using the sheet material 1, but can have sufficient durability.

The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the filter according to the present invention can be variously modified within the range intended by the present invention.
The filter according to the present invention is suitable for an inflator of an airbag, but is not limited to this, and can be used for various applications.

F Filter 1 Sheet material 50 Hexagonal cell

Claims (1)

A donut-shaped sheet material in which a plurality of arc-shaped slits are provided in a regular arrangement in the normal direction and the circumferential direction is used as a material,
The sheet material is folded at both a circumferential direction and a normal direction so that the plurality of arc-shaped slits serve as hexagonal cell openings, whereby the sheet material has a three-dimensional donut having a honeycomb structure. Assembled into a shape,
A filter comprising a plurality of holes for obtaining air permeability from the inside of the innermost peripheral cell to the outer side of the outermost peripheral cell in the wall portion constituting the honeycomb structure.

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