Filter and gas generator provided with filter

Abstract

[Problem] To provide a filter that is capable of suppressing overlapping of an expanded metal part in a nested state and that can be manufactured more easily, and a gas generator including the filter. [Solution] A filter 100 includes a filter body 110, and is formed by winding the filter body 110. The filter body 110 includes: an expanded metal part 120 composed of an expanded metal formed by pushing and expanding a plurality of cuts arranged in a staggered manner in an extrusion direction; and a suppression structure for suppressing overlapping of the expanded metal part 120 in a nested state while the filter body 110 is in the state of being wound.

Description

Filter and gas generator including filter

[0001] The present invention relates to a filter for a gas generator incorporated in an occupant protection device that protects an occupant in the event of a collision of a vehicle or the like, and to a gas generator equipped with a filter.

[0002] Airbag devices, which are passenger protection devices, have become widespread from the viewpoint of protecting passengers in automobiles, etc. Airbag devices are installed to protect passengers from impacts that occur during a vehicle collision, and the airbag instantly inflates and deploys during a vehicle collision, thereby acting as a cushion to support the passenger's body.

[0003] Gas generators have a variety of structures, but a gas generator that is particularly suitable for use in a driver's side airbag device, a passenger's side airbag device, etc. is a short, approximately cylindrical disk-type gas generator with a relatively large outer diameter.

[0004] A disk-type gas generator has a short, approximately cylindrical housing with both axial ends closed, a plurality of gas outlets provided in the peripheral wall of the housing, a transfer charge contained inside the housing so as to face an igniter assembled to the housing, a gas generating agent filled inside the housing so as to surround the transfer charge, and a filter contained inside the housing so as to further surround the gas generating agent.

[0005] For example, U.S. Patent No. 5,929,949 discloses a cylindrical filter made of expanded metal sheet having rows of openings arranged to reduce nesting when the expanded metal sheet is rolled up.

[0006] Special Publication No. 2010-504218

[0007] However, the filter of Patent Document 1 has a problem in that the manufacturing process becomes complicated because the spacing between rows of openings needs to be made non-uniform.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a filter that can prevent expanded metal portions from overlapping in a nested state and that can be manufactured more simply, and a gas generator equipped with the filter.

[0009] (1) A filter of the present invention includes a filter body and is formed by winding the filter body. The filter body has an expanded metal portion made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal portions from overlapping in a nested manner when the filter body is wound.

[0010] (2) In the filter of (1) above, it is preferable that the suppression structure include a gap forming structure that forms a gap in a radial direction of the filter body so that the expanded metal portions overlap with a gap when the filter body is wound.

[0011] (3) In the filter of (2) above, it is preferable that, in a state in which the filter body is wound, the gap-forming structure has a folded-back portion formed by folding back an axial end of the filter body to one side in the radial direction in each of one or more layers of the filter body and contacting an adjacent layer on the one side in the radial direction, and that the folded-back portion of each of the one or more layers forms the gap so as to be adjacent to the folded-back portion in the axial direction.

[0012] (4) In the filter of (2) above, it is preferable that, when the filter body is wound, the gap-forming structure has a protrusion in each of one or more layers of the filter body that extends in the winding direction of the filter body, protrudes to one side in the radial direction, and contacts an adjacent layer on that side in the radial direction, and that the protrusion of each of the one or more layers forms the gap so as to be adjacent to the protrusion in the axial direction of the filter body.

[0013] (5) In the filter of (1) above, the suppression structure preferably includes an arrangement structure in which, when the filter body is wound, the expanded metal portions are arranged so that the extrusion direction of the expanded metal portion of each layer of the filter body intersects with the extrusion direction of the expanded metal portion of an adjacent layer.

[0014] (6) In the filter of (5) above, the arrangement structure preferably includes a structure in which a plurality of the expanded metal sections are arranged in a stacked manner before the filter body is wound, and the extrusion direction of each of the plurality of expanded metal sections preferably intersects the extrusion direction of adjacent ones of the plurality of expanded metal sections.

[0015] (7) In the filter of (5) above, the arrangement structure preferably includes a structure in which, before the filter body is wound, a plurality of the expanded metal sections are connected and arranged in a direction perpendicular to the thickness direction of the expanded metal section, and the extrusion direction of each of the plurality of expanded metal sections intersects with the extrusion direction of adjacent ones of the plurality of expanded metal sections.

[0016] (8) In the filter of (1) above, the suppression structure preferably includes an arrangement structure in which the expanded metal portions are arranged such that, when the filter body is wound, the position of the expanded metal portion of each layer of the filter body differs from the position of the expanded metal portion of an adjacent layer in the axial direction of the filter body.

[0017] (9) A gas generator of the present invention is characterized by comprising: a gas generating agent that generates gas by combustion; an igniter that ignites and burns the gas generating agent; a filter according to any one of (1) to (8) above through which the gas passes; and a housing that has a gas outlet for ejecting the gas that has passed through the filter and that accommodates the gas generating agent, the igniter, and the filter.

[0018] According to the present invention, it is possible to provide a filter that can prevent expanded metal portions from overlapping one another in a nested state and that can be manufactured more simply, and a gas generator that includes the filter.

[0019] FIG. 1 is a perspective view showing a filter according to a first embodiment of the present invention. FIG. 1 is a perspective view showing a state before the filter body of the filter of FIG. 1 is wound. FIG. 2 is a schematic view showing an expanded metal portion. FIG. 3 is a schematic view showing a state in which expanded metal portions are overlapped in a nested state. FIG. 1 is an end view showing a portion of the filter of FIG. 1. FIG. 1 is an end view showing a portion of the filter of FIG. 1. FIG. 2 is a perspective view showing a filter according to a second embodiment of the present invention. FIG. 7 is a perspective view showing a state before the filter body of the filter of FIG. 7 is wound. FIG. 7 is an end view showing a portion of the filter of FIG. 7. FIG. 3 is a perspective view showing a filter according to a third embodiment of the present invention. FIG. 10 is a perspective view showing a state before the filter body of the filter of FIG. 10 is wound. FIG. 10 is an end view showing a portion of the filter of FIG. 10. FIG. 4 is a perspective view showing a filter according to a fourth embodiment of the present invention. FIG. 13 is a perspective view showing a state before the filter body of the filter of FIG. 13 is wound. FIG. 13 is an end view showing a portion of the filter of FIG. 13. FIG. 5 is a perspective view showing a filter according to a fifth embodiment of the present invention. FIG. 16 is a perspective view showing a state before the filter body of the filter of FIG. 16 is wound. FIG. 16 is an end view showing a portion of the filter of FIG. 16. FIG. 6 is a perspective view showing a filter according to a sixth embodiment of the present invention. FIG. 19 is a perspective view showing a state before the filter body of the filter of FIG. 19 is wound. Fig. 26 is an end view showing a part of the filter of Fig. 19. Fig. 27 is a perspective view showing a filter according to a seventh embodiment of the present invention. Fig. 28 is a perspective view showing a state before the filter body of the filter of Fig. 22 is wound. Fig. 29 is an end view showing a part of the filter of Fig. 22. Fig. 30 is a perspective view showing a filter according to an eighth embodiment of the present invention. Fig. 31 is a perspective view showing a state before the filter body of the filter of Fig. 25 is wound. Fig. 32 is a schematic cross-sectional view showing a gas generator according to a ninth embodiment of the present invention.

[0020] First Embodiment A filter 100 according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 6. FIG.

[0021] FIG. 1 is a perspective view showing a filter 100 according to a first embodiment of the present invention. FIG. 2 is a perspective view showing a state before the filter body 110 of the filter 100 of FIG. 1 is wound. FIG. 2 shows a portion of the filter body 110. FIG. 3 is a schematic diagram showing an expanded metal portion 120. FIG. 3A shows a manufacturing method of the expanded metal portion 120, and FIG. 3B shows a bond 123 and an opening 124 of a portion of the expanded metal portion 120. FIG. 4 is a schematic diagram showing a state in which expanded metal portions 120 are nested and overlapped. FIG. 5 is an end view showing a portion of the filter 100 of FIG. 1. FIG. 5 shows an end surface of a portion of the filter 100 cut in the radial direction. FIG. 6 is an end view showing a portion of the filter 100 of FIG. 1. FIG. 6 shows an end surface of a portion of the filter 100 cut in a direction perpendicular to the axial direction. In FIGS. 1, 2, and 5, the expanded metal portion 120 is schematically indicated by cross-hatching. Furthermore, since each figure is a schematic diagram, it is not necessarily an accurate illustration, and therefore the scales etc. in each figure do not necessarily match.

[0022] As shown in FIGS. 1 and 2 , the filter 100 includes a filter body 110 and is formed by winding the filter body 110. Before being wound, the filter body 110 extends in a first direction (see arrow A1 in FIG. 2 , etc.) and a second direction (see arrow B1 in FIG. 2 , etc.) perpendicular to the first direction. The filter 100 is formed by winding the filter body 110 around the first direction. That is, the first direction is the axial direction of the filter body 110 when the filter body 110 is wound. Note that, hereinafter, the axial direction of the filter body 110 may be simply referred to as the axial direction. The filter body 110 includes an expanded metal portion 120 and a suppression structure (folded portions 130, 131) that suppresses overlapping of the expanded metal portion 120 when the filter body 110 is wound. In this embodiment, the entire filter body 110 is formed of the expanded metal portion 120.

[0023] The expanded metal part 120 is made of an expanded metal formed by expanding a plurality of staggered cuts in the extrusion direction. In other words, the expanded metal part 120 is made of a general expanded metal.

[0024] 3A, the expanded metal part 120 is formed by stretching in one direction by repeatedly feeding the sheet material 1 and making slits in the sheet material 1 with a punch 2 or the like and pushing the sheet material 1 in the extrusion direction to widen the slits. By repeating these steps, the slits are arranged in a staggered pattern and widened, forming bonds 123, strands (not shown), openings 124, etc., and the expanded metal part 120 is formed.

[0025] As shown in FIG. 3B , in this embodiment, the expanded metal part 120 is formed by being stretched in the second direction and is formed so that the openings 124 appear open when viewed from a third direction (see arrow C1 in FIG. 3 , etc.) that is perpendicular to both the first and second directions. The extrusion direction (see arrow D1 in FIG. 3 , etc.) in which the punch 2 extrudes the slits to widen them is perpendicular to the first direction and inclined relative to the second and third directions. In the expanded metal part 120, multiple slits are arranged in a staggered pattern, and multiple openings 124 are formed by widening the staggered slits. Therefore, in the expanded metal part 120, multiple openings 124 are arranged in rows at equal intervals in the first direction, and these rows are arranged in a zigzag pattern at equal intervals in the second direction.

[0026] As the plate material 1, for example, a steel plate (mild steel) or a stainless steel plate can be suitably used, and a non-ferrous metal plate such as aluminum, copper, titanium, nickel or an alloy thereof can also be used.

[0027] The suppression structure prevents the expanded metal portions 120 from overlapping and nesting when the filter body 110 is wound. For example, "nested and overlapping" refers to the bonds 123 and strands (not shown) overlapping without any gaps, as shown in FIG. 4 . If overlapping and nesting of the expanded metal portions 120 occurs when the filter body 110 is wound, the thickness of the filter 100 may become non-uniform and the flow of gas and other substances passing through the filter 100 may become uneven. In the filter 100, the suppression structure prevents the expanded metal portions 120 from overlapping and nesting when the filter body 110 is wound, thereby preventing the thickness of the filter 100 from becoming non-uniform and the flow of gas and other substances passing through the filter 100 from becoming uneven.

[0028] As shown in Fig. 5 , the suppression structure includes a gap forming structure that forms gaps 140b, 140c in the radial direction (see arrow E1 in Fig. 5 , etc.) of the filter body 110 so that the expanded metal portions 120 overlap with gaps 140b, 140c when the filter body 110 is wound. Note that hereinafter, the radial direction of the filter body 110 may be simply referred to as the radial direction. The gap forming structure has folded portions 130, 131, which form the gaps 140b, 140c.

[0029] The folded-back portions 130, 131 are formed by folding back an axial end portion of each of one or more layers of the filter body 110 toward one radial side when the filter body 110 is wound, and are in contact with the layer adjacent to that radial side. In the present embodiment, the folded-back portions 130 are formed by folding back one axial end portion of each of the first layer 130A, the second layer 130B, and the third layer 130C of the filter body 110 toward the radially inward side when the filter body 110 is wound.

[0030] Of the folded portions 130, the folded portion 130a of the first layer 130A is formed by folding one axial end of the first layer 130A back inward in the radial direction. Of the folded portions 130, the folded portion 130b of the second layer 130B is formed by folding one axial end of the second layer 130B back inward in the radial direction, and is in contact with the adjacent first layer 130A on the radially inner side. Of the folded portions 130, the folded portion 130c of the third layer 130C is formed by folding one axial end of the third layer 130C back inward in the radial direction, and is in contact with the adjacent second layer 130B on the radially inner side.

[0031] Furthermore, when the filter body 110 is wound, the folded-back portions 131 are formed by folding back the other axial end portion of each of the first layer 130A, the second layer 130B, and the third layer 130C of the filter body 110 radially inward. Of the folded-back portions 131, the folded-back portion 131a of the first layer 130A is formed by folding back the other axial end portion of the first layer 130A radially inward. Of the folded-back portions 131, the folded-back portion 131b of the second layer 130B is formed by folding back the other axial end portion of the second layer 130B radially inward and is in contact with the adjacent first layer 130A on the radially inner side. Of the folded portions 131, the folded portion 131c of the third layer 130C is formed by folding the other axial end of the third layer 130C radially inward, and is in contact with the adjacent second layer 130B radially inward.

[0032] Furthermore, when the filter body 110 is wound, the folded-back portions 130, 131 extend in the winding direction (see arrow F1 in FIG. 1 etc.) of the filter body 110. Note that, hereinafter, the winding direction of the filter body 110 may be simply referred to as the winding direction.

[0033] A gap is formed between each of the folded portions 130, 131 of one or more layers so that the folded portions are adjacent to each other in the axial direction. In this embodiment, of the folded portions 130, 131, the folded portions 130b, 131b of the second layer 130B form a gap 140b between them so that they are adjacent to each other in the axial direction. Of the expanded metal portion 120, the expanded metal portion 120a of the first layer 130A and the expanded metal portion 120b of the second layer 130B overlap with a gap 140b in the radial direction. Of the folded portions 130, 131, the folded portions 130c, 131c of the third layer 130C are adjacent to the folded portions 130c, 131c in the axial direction, forming a gap 140c between them. Of the expanded metal portion 120, the expanded metal portion 120b of the second layer 130B and the expanded metal portion 120c of the third layer 130C overlap with a gap 140c in the radial direction.

[0034] Furthermore, folded portions 130 and 131 are part of the expanded metal portion 120. Furthermore, contact portion 132, which comes into contact with folded portion 130 when the filter body 110 is wound, and contact portion 133, which comes into contact with folded portion 131 when the filter body 110 is wound, are part of the expanded metal portion 120. In other words, folded portions 130 and 131 and contact portions 132 and 133 are made of expanded metal. Therefore, folded portion 130 and contact portion 132 overlap with the front sides or back sides of the expanded metal butting against each other, and folded portion 131 and contact portion 133 overlap with the front sides or back sides of the expanded metal butting against each other.

[0035] Furthermore, among the contact portions 132, the contact portion 132a of the first layer 130A is in contact with the folded portion 130a and the folded portion 130b. Among the contact portions 132, the contact portion 132b of the second layer 130B is in contact with the folded portion 130b and the folded portion 130c. Among the contact portions 132, the contact portion 132c of the third layer 130C is in contact with the folded portion 130c.

[0036] Furthermore, among the contact portions 133, the contact portion 133a of the first layer 130A is in contact with the folded portion 131a and the folded portion 131b. Among the contact portions 133, the contact portion 133b of the second layer 130B is in contact with the folded portion 131b and the folded portion 131c. Among the contact portions 133, the contact portion 133c of the third layer 130C is in contact with the folded portion 131c.

[0037] As shown in Fig. 6, the extrusion direction of the contact portion 132a (see arrow D1 in Fig. 3, etc.) intersects with the extrusion direction of the folded portion 130a and also intersects with the extrusion direction of the folded portion 130b. In this embodiment, the extrusion direction of the contact portion 132a is symmetrical with the extrusion direction of the folded portion 130a and also symmetrical with the extrusion direction of the folded portion 130b. Furthermore, the extrusion direction of the contact portion 132b intersects with the extrusion direction of the folded portion 130b and also intersects with the extrusion direction of the folded portion 130c.

[0038] In this embodiment, the pushing direction of the contact portion 132b is symmetrical to the pushing direction of the folded portion 130b and is symmetrical to the pushing direction of the folded portion 130c. Furthermore, the pushing direction of the contact portion 132c intersects with the pushing direction of the folded portion 130c. In this embodiment, the pushing direction of the contact portion 132c is symmetrical to the pushing direction of the folded portion 130c. Therefore, it is possible to prevent the folded portion 130 and the contact portion 132 from overlapping in a nested state. The same applies to the folded portion 131 and the contact portion 133.

[0039] 6 shows a state in which the end of each bond 123 is in contact with the end of the bond 123 adjacent in the direction of the arrow E1, but the ends of the bonds 123 do not necessarily have to be in contact with each other. In other words, gaps may be formed between all or some of the ends of the bonds 123.

[0040] 2, the folded-back portion 130 is formed by folding back one end of the filter body 110 in the first direction to one side before the filter body 110 is wound, and extends in the second direction. Also, the folded-back portion 131 is formed by folding back the other end of the filter body 110 in the first direction to one side before the filter body 110 is wound, and extends in the second direction. Thus, by winding the filter body 110 with the folded-back portions 130 and 131 formed therein in the first direction, the gaps 140b and 140c described above can be formed.

[0041] As described above, the filter 100 in the first embodiment of the present invention described above includes the filter body 110, and is a filter formed by winding the filter body 110. The filter body 110 has an expanded metal section 120 made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal sections 120 from overlapping in a nested state when the filter body 110 is wound.

[0042] This allows for the use of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal sections 120 from overlapping in a nested state when the filter body 110 is wound around it. In other words, this prevents the expanded metal sections 120 from overlapping in a nested state, and allows for easier production of the filter 100.

[0043] Furthermore, in the filter 100 according to the first embodiment of the present invention described above, the suppression structure includes a gap forming structure that forms gaps 140 b, 140 c in the radial direction of the filter body 110 so that the expanded metal portions 120 overlap with gaps 140 b, 140 c left therein when the filter body 110 is wound.

[0044] This makes it possible to more reliably prevent the expanded metal portions 120 from overlapping one another in a nested state when the filter body 110 is wound around the filter body 110 by the gaps 140b and 140c.

[0045] Furthermore, in the filter 100 of the first embodiment of the present invention described above, the gap-forming structure has folded-back portions 130, 131 formed by folding back the axial end of the filter body 110 to one radial side in each of one or more layers of the filter body 110 when the filter body 110 is wound, and the folded-back portions 130, 131 contact the layer adjacent to the folded-back portion in the radial direction, and the folded-back portions 130, 131 of the one or more layers form gaps 140b, 140c so as to be adjacent to the folded-back portion in the axial direction.

[0046] This allows the folded portions 130 and 131 to more easily form the gaps 140b and 140c.

[0047] In the filter 100 according to the first embodiment of the present invention described above, the folded portions 130, 131 and the contact portions 132, 133 that come into contact with the folded portions 130, 131 when the filter body 110 is wound are part of the expanded metal portion 120.

[0048] This allows the folded portions 130, 131 to be formed more easily by folding back a portion of the expanded metal portion 120, and also prevents the folded portions 130, 131 and the contact portions 132, 133 from overlapping in a nested state.

[0049] In the first embodiment described above, the case where the folded portions 130 and 131 are formed has been described, but the present invention is not limited to this. For example, only one of the folded portions 130 and 131 may be formed.

[0050] In the first embodiment described above, the folded portions 130, 131 and the contact portions 132, 133 are part of the expanded metal portion 120, but this is not limiting. For example, the folded portions and the contact portions may be formed as plate members or the like without openings.

[0051] In the first embodiment described above, the folded-back portions 130 and 131 are formed by being folded back radially inward, but this is not limiting. For example, the folded-back portions may be formed by being folded back radially outward.

[0052] In the first embodiment described above, the case where the folded portions 130 and 131 are formed has been described, but the present invention is not limited to this. For example, instead of the folded portions, gaps similar to 140b and 140c may be formed by attaching a plate material or the like.

[0053] Second Embodiment A filter 200 according to a second embodiment of the present invention will now be described with reference to FIGS.

[0054] FIG. 7 is a perspective view showing a filter 200 according to a second embodiment of the present invention. FIG. 8 is a perspective view showing the filter body 210 of the filter 200 of FIG. 7 before it is wound. FIG. 9 is an end view showing a portion of the filter 200 of FIG. 7. FIG. 9 shows an end face of a portion of the filter 200 cut in the radial direction. In FIGS. 7 to 9, the expanded metal portions 220, 221, and 222 are schematically shown by cross-hatching. Furthermore, the drawings are schematic diagrams and are not necessarily drawn to scale. Therefore, the scales and the like do not necessarily match in the drawings.

[0055] As shown in FIGS. 7 and 8 , the filter 200 includes a filter body 210 and is formed by winding the filter body 210. Before being wound, the filter body 210 extends in a first direction (see arrow A2 in FIG. 8 , etc.) and a second direction (see arrow B2 in FIG. 8 ) perpendicular to the first direction. The filter 200 is formed by winding the filter body 210 around the first direction. In other words, the first direction is the axial direction of the filter body 210 when the filter body 210 is wound. Note that, hereinafter, the axial direction of the filter body 210 may be simply referred to as the axial direction. The filter body 210 includes expanded metal portions 220, 221, and 222 and a suppression structure (protrusions 234 and 235) that suppresses overlapping of the expanded metal portions 220, 221, and 222 in a nested state when the filter body 210 is wound.

[0056] The expanded metal parts 220, 221, and 222 are made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction. In other words, the expanded metal parts 220, 221, and 222 are made of general expanded metal. The expanded metal parts 220, 221, and 222 are formed in the same manner as the expanded metal part 120 according to the first embodiment. In this embodiment, the expanded metal parts 220, 221, and 222 are formed by being stretched in the second direction so that openings (not shown) in the expanded metal appear open when viewed from a third direction (see arrow C2 in FIG. 8 ) that is perpendicular to both the first and second directions. The extrusion direction used by the punch to expand the slits is perpendicular to the first direction and inclined relative to the second and third directions. In expanded metal parts 220, 221, and 222, multiple slits are arranged in a staggered pattern, and multiple expanded metal openings (not shown) are formed by expanding the staggered slits. Therefore, in expanded metal parts 220, 221, and 222, multiple expanded metal openings (not shown) are arranged in rows at equal intervals in the first direction, and these rows are arranged in a zigzag pattern at equal intervals in the second direction.

[0057] The suppression structure prevents the expanded metal portions 220, 221, and 222 from overlapping and nesting when the filter body 210 is wound. For example, "nested overlapping" refers to overlapping in a manner similar to that shown in FIG. 4 . If overlapping and nesting portions of the expanded metal portions 220, 221, and 222 occur when the filter body 210 is wound, the thickness of the filter 200 will become non-uniform and variations in the flow of gas and other substances passing through the filter 200 will occur. In the filter 200, the suppression structure prevents the expanded metal portions 220, 221, and 222 from overlapping and nesting when the filter body 210 is wound, thereby preventing the thickness of the filter 200 from becoming non-uniform and variations in the flow of gas and other substances passing through the filter 200.

[0058] As shown in Fig. 9 , the suppression structure includes a gap forming structure that forms gaps 240a, 240b, 241a, 241b, 242a, and 242b in the radial direction (see arrow E2 in Fig. 9 , etc.) of the filter body 210 when the filter body 210 is wound, such that the expanded metal portions 220 overlap with gaps 240a and 240b, the expanded metal portions 221 overlap with gaps 241a and 241b, and the expanded metal portions 222 overlap with gaps 242a and 242b. Note that hereinafter, the radial direction of the filter body 210 may be simply referred to as the radial direction. The gap forming structure has protrusions 234 and 235, and the protrusions 234 and 235 form the gaps 240a, 240b, 241a, 241b, 242a, and 242b.

[0059] When the filter body 210 is wound, the protrusions 234, 235 extend in the winding direction of the filter body 210 (see arrow F2 in FIG. 7 ) in each of one or more layers of the filter body 210, protrude to one radial side, and contact the layer adjacent to that side in the radial direction. Note that, hereinafter, the winding direction of the filter body 210 may be simply referred to as the winding direction. In this embodiment, when the filter body 210 is wound, the protrusions 234, 235 are bent in a generally trapezoidal or U-shaped shape so as to be convex outward in the radial direction. The height of the outer surfaces of the protrusions 234, 235 (see arrow G2 in FIG. 9 ) is greater than the height of the inner surfaces of the protrusions 234, 235 (see arrow H2 in FIG. 9 ).

[0060] The protrusions 234 are connected to the expanded metal portions 220 and 221. When the filter body 210 is wound, the protrusions 234 extend in the winding direction of the filter body 210, protrude radially outward, and contact the adjacent layer on the radial outside in each of the first layer 210A, second layer 210B, and third layer 210C of the filter body 210. Of the protrusions 234, the protrusion 234a of the first layer 210A extends in the winding direction of the filter body 210, protrudes radially outward, and contacts the adjacent second layer 210B on the radial outside. Specifically, the protrusion 234a is in contact with the protrusion 234b of the second layer 210B with only its tip fitted in the concave surface of the protrusion 234b on the first layer 210A side. Of the protrusions 234, protrusion 234b of second layer 210B extends in the winding direction of filter body 210, protrudes radially outward, and contacts adjacent third layer 210C on the radially outer side. Specifically, protrusion 234b contacts protrusion 234c of third layer 210C with only its tip portion fitted in the concave surface of protrusion 234c on the second layer 210B side. Of the protrusions 234, protrusion 234c of third layer 210C extends in the winding direction of filter body 210 and protrudes radially outward.

[0061] Furthermore, the protrusions 235 are connected to the expanded metal portions 221 and 222. When the filter body 210 is wound, the protrusions 235 extend in the winding direction of the filter body 210, protrude radially outward, and contact the adjacent layer on the radial outside in each of the first layer 210A, second layer 210B, and third layer 210C of the filter body 210. Of the protrusions 235, the protrusion 235a of the first layer 210A extends in the winding direction of the filter body 210, protrudes radially outward, and contacts the adjacent second layer 210B on the radial outside. Specifically, the protrusion 235a is in contact with the protrusion 235b of the second layer 210B with only its tip fitted in the concave surface of the protrusion 235b on the first layer 210A side. Of the protrusions 235, protrusion 235b of second layer 210B extends in the winding direction of filter body 210, protrudes radially outward, and contacts adjacent third layer 210C on the radially outer side. Specifically, protrusion 235b contacts protrusion 235c of third layer 210C with only its tip portion fitted in the concave surface of protrusion 235c on the second layer 210B side. Of the protrusions 235, protrusion 235c of third layer 210C extends in the winding direction of filter body 210 and protrudes radially outward.

[0062] The protruding portions 234, 235 of the one or more layers form gaps so that they are adjacent to each other in the axial direction. In this embodiment, of the protruding portions 234, 235, the protruding portions 234a, 235a of the first layer 210A form gaps 240a, 241a, 242a so that they are adjacent to the protruding portions 234a, 235a. Of the expanded metal portion 220, the expanded metal portion 220a of the first layer 210A and the expanded metal portion 220b of the second layer 210B overlap with a gap 240a in the radial direction.

[0063] Of the expanded metal portion 221, the expanded metal portion 221a of the first layer 210A and the expanded metal portion 221b of the second layer 210B overlap with a gap 241a in the radial direction. Of the expanded metal portion 222, the expanded metal portion 222a of the first layer 210A and the expanded metal portion 222b of the second layer 210B overlap with a gap 242a in the radial direction. Furthermore, of the protruding portions 234, 235, the protruding portions 234b, 235b of the second layer 210B form gaps 240b, 241b, and 242b so that they are adjacent to the protruding portions 234b, 235b.

[0064] Of the expanded metal part 220, the expanded metal part 220b of the second layer 210B and the expanded metal part 220c of the third layer 210C overlap with a gap 240b in the radial direction. Of the expanded metal part 221, the expanded metal part 221b of the second layer 210B and the expanded metal part 221c of the third layer 210C overlap with a gap 241b in the radial direction. Of the expanded metal part 222, the expanded metal part 222b of the second layer 210B and the expanded metal part 222c of the third layer 210C overlap with a gap 242b in the radial direction.

[0065] The protrusions 234, 235 do not include expanded metal. Furthermore, the contact portions that come into contact with the protrusions 234, 235 when the filter body 210 is wound do not include expanded metal. In the present embodiment, the protrusions 234b, 234c are an example of contact portions that come into contact with the protrusion 234 when the filter body 210 is wound. Furthermore, the protrusions 235b, 235c are an example of contact portions that come into contact with the protrusion 235 when the filter body 210 is wound. For example, the protrusions 234, 235 are formed by bending a plate material or the like that does not have an opening.

[0066] 8 , protrusions 234 and 235 extend in the second direction and protrude to one side in the third direction before filter body 210 is wound. In this manner, by winding filter body 210 on which protrusions 234 and 235 are formed in the first direction, gaps 240 a, 240 b, 241 a, 241 b, 242 a, and 242 b as described above can be formed.

[0067] As described above, filter 200 in the second embodiment of the present invention described above includes filter body 210, and is a filter formed by winding filter body 210. Filter body 210 has expanded metal portions 220, 221, 222 made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses expanded metal portions 220, 221, 222 from overlapping in a nested state when filter body 210 is wound.

[0068] This makes it possible to use expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal portions 220, 221, and 222 from overlapping and nesting when the filter body 210 is wound around it. In other words, it is possible to prevent the expanded metal portions 220, 221, and 222 from overlapping and nesting, and the filter 100 can be manufactured more easily.

[0069] Furthermore, in the filter 200 according to the second embodiment of the present invention described above, the suppression structure includes a gap forming structure that forms gaps 240a, 240b, 241a, 241b, 242a, and 242b in the radial direction of the filter body 210 so that the expanded metal portions 220, 221, and 222 overlap with each other when the filter body 210 is wound.

[0070] With this, the gaps 240a, 240b, 241a, 241b, 242a, and 242b can more reliably prevent the expanded metal portions 220, 221, and 222 from overlapping one another in a nested state when the filter body 210 is wound.

[0071] Furthermore, in the filter 200 of the second embodiment of the present invention described above, the gap forming structure has protrusions 234, 235 in each of one or more layers of the filter body 210, which extend in the winding direction of the filter body 210, protrude to one radial side, and contact the layer adjacent to that side in the radial direction, when the filter body 210 is wound, and the protrusions 234, 235 of the one or more layers form gaps 240a, 240b, 241a, 241b, 242a, 242b so as to be adjacent to the protrusions in the axial direction of the filter body 210.

[0072] This allows the protrusions 234 and 235 to more easily form the gaps 240a, 240b, 241a, 241b, 242a, and 242b.

[0073] In the filter 200 according to the second embodiment of the present invention, the protruding portions 234, 235 and the contact portions that come into contact with the protruding portions 234, 235 when the filter body 210 is wound do not include expanded metal.

[0074] This can prevent the expanded metal from overlapping in a nested state at the portions where the protrusions 234, 235 and the contact portions come into contact with each other.

[0075] In the second embodiment described above, the protrusions 234 and 235 are formed, but the present invention is not limited to this. For example, only one of the protrusions 234 and 235 may be formed.

[0076] In the second embodiment described above, the protrusions 234, 235 protrude outward in the radial direction, but this is not limiting. For example, the protrusions may protrude inward in the radial direction.

[0077] In addition, in the second embodiment described above, (a) the protrusion 234a is in contact with the protrusion 234b when fitted into the concave surface of the protrusion 234b of the second layer 210B on the first layer 210A side, (b) the protrusion 234b is in contact with the protrusion 234c when fitted into the concave surface of the protrusion 234c of the third layer 210C on the second layer 210B side, (c) the protrusion 235a is in contact with the protrusion 235b when fitted into the concave surface of the protrusion 235b of the second layer 210B on the first layer 210A side, and (d) the protrusion 235b is in contact with the protrusion 235c when fitted into the concave surface of the protrusion 235c of the third layer 210C on the second layer 210B side, but this is not limited to these. For example, in the above (a), the length of the trapezoidal upper side of the protruding portion 234a may be longer than the width of the concave surface of the protruding portion 234b on the first layer 210A side so that the protruding portion 234a does not fit into the concave surface of the protruding portion 234b of the second layer 210B on the first layer 210A side. The same applies to the above (b) to (d).

[0078] Third Embodiment A filter 300 according to a third embodiment of the present invention will be described below with reference to Figs. 10 to 12. In this embodiment, parts having the same reference numerals as those in the second embodiment down to the last two digits are the same as those in the second embodiment, and therefore their description may be omitted. In addition, parts not particularly described in this embodiment are the same as those in the second embodiment, and therefore their description and illustration may be omitted.

[0079] FIG. 10 is a perspective view showing a filter 300 according to a third embodiment of the present invention. FIG. 11 is a perspective view showing the filter body 310 of the filter 300 of FIG. 10 before it is wound. FIG. 12 is an end view showing a portion of the filter 300 of FIG. 10. FIG. 12 shows an end surface of a portion of the filter 300 cut radially. Note that in FIGS. 10 to 12, expanded metal portions 320, 321, and 322 are schematically indicated by cross-hatching. Furthermore, since each figure is a schematic view, it is not necessarily an accurate illustration. Therefore, the scales and the like do not necessarily match between the figures. Also, A3, B3, C3, E3, and F3 in FIGS. 10 to 12 indicate the same directions as A2, B2, C2, E2, and F2 in FIGS. 7 to 9.

[0080] As shown in FIGS. 10-12, filter 300 differs from filter 200 primarily in that the shape of protrusions 334 and 335 differs from the shape of protrusions 234 and 235 .

[0081] The protrusions 334, 335 differ from the protrusions 234, 235 mainly in that the protrusions 334, 335 are curved in a generally U-shape so as to be convex radially outward when the filter body 310 is wound. The height of the outer surfaces of the protrusions 334, 335 (see arrow G3 in FIG. 12 ) is greater than the height of the inner surfaces of the protrusions 334, 335 (see arrow H3 in FIG. 12 ). For example, the protrusions 334, 335 are formed by bending a plate or the like that does not have any openings.

[0082] The filter 300 of the third embodiment provides the same effects as the filter 200 of the second embodiment.

[0083] In the third embodiment described above, the protrusions 334 and 335 are formed, but the present invention is not limited to this. For example, only one of the protrusions 334 and 335 may be formed.

[0084] In the third embodiment described above, the protrusions 334 and 335 protrude outward in the radial direction, but this is not limiting. For example, the protrusions may protrude inward in the radial direction.

[0085] <Fourth embodiment> A filter 400 according to a fourth embodiment of the present invention will be described below with reference to Figs. 13 to 15. In this embodiment, parts having the same reference numerals as those in the second embodiment down to the last two digits are the same as those in the second embodiment, and therefore their description may be omitted. Furthermore, parts not particularly described in this embodiment are the same as those in the second embodiment, and therefore their description and illustration may be omitted.

[0086] FIG. 13 is a perspective view showing a filter 400 according to a fourth embodiment of the present invention. FIG. 14 is a perspective view showing the filter body 410 of the filter 400 of FIG. 13 before it is wound. FIG. 15 is an end view showing a portion of the filter 400 of FIG. 13. FIG. 15 shows an end surface of a portion of the filter 400 cut radially. Note that in FIGS. 13 to 15, expanded metal portions 420, 421, and 422 are schematically indicated by cross-hatching. Furthermore, since each figure is a schematic view, it is not necessarily an accurate illustration. Therefore, the scales and the like do not necessarily match between the figures. Also, A4, B4, C4, E4, and F4 in FIGS. 13 to 15 indicate the same directions as A2, B2, C2, E2, and F2 in FIGS. 7 to 9.

[0087] As shown in FIGS. 13-15, filter 400 differs from filter 200 primarily in that the shape of protrusions 434, 435 differs from the shape of protrusions 234, 235.

[0088] The protrusions 434, 435 differ from the protrusions 234, 235 mainly in that they are bent in a generally V-shape so as to be convex radially outward when the filter body 410 is wound. The height of the outer surfaces of the protrusions 434, 435 (see arrow G4 in FIG. 15 ) is greater than the height of the inner surfaces of the protrusions 434, 435 (see arrow H4 in FIG. 15 ). For example, the protrusions 434, 435 are formed by bending a plate material or the like that does not have any openings.

[0089] The filter 400 of the fourth embodiment provides the same effects as the filter 200 of the second embodiment.

[0090] In the fourth embodiment described above, the protrusions 434 and 435 are formed, but the present invention is not limited to this. For example, only one of the protrusions 434 and 435 may be formed.

[0091] In the fourth embodiment described above, the protrusions 434, 435 protrude outward in the radial direction, but this is not limiting. For example, the protrusions may protrude inward in the radial direction.

[0092] Fifth Embodiment A filter 500 according to a fifth embodiment of the present invention will now be described with reference to FIGS.

[0093] FIG. 16 is a perspective view showing a filter 500 according to a fifth embodiment of the present invention. FIG. 17 is a perspective view showing the filter 500 of FIG. 16 in a state before the filter body 510 is wound. FIG. 18 is an end view showing a portion of the filter 500 of FIG. 16. FIG. 18(a) shows an end surface of a portion of the filter body 510 cut in a direction perpendicular to the first direction before the filter body 510 is wound. FIG. 18(b) shows an end surface of a portion of the filter 500 cut in a direction perpendicular to the axial direction. In FIGS. 16 and 17, expanded metal portions 520 and 521 are schematically indicated by cross-hatching. The figures are schematic views and are not necessarily drawn precisely. Therefore, the scales and the like do not necessarily match between the figures.

[0094] As shown in FIGS. 16 and 17 , the filter 500 includes a filter body 510 and is formed by winding the filter body 510. Before being wound, the filter body 510 extends in a first direction (see arrow A5 in FIG. 17 , etc.) and a second direction (see arrow B5 in FIG. 17 , etc.) perpendicular to the first direction. The filter 500 is formed by winding the filter body 510 around the first direction. In other words, the first direction is the axial direction of the filter body 510 when the filter body 510 is wound. Note that, hereinafter, the axial direction of the filter body 510 may be simply referred to as the axial direction. The filter body 510 includes expanded metal portions 520 and 521 and a suppression structure that suppresses overlapping of the expanded metal portions 520 and 521 in a nested state when the filter body 510 is wound.

[0095] The expanded metal parts 520 and 521 are made of expanded metal formed by expanding multiple staggered slits in the extrusion direction. In other words, the expanded metal parts 520 and 521 are made of general expanded metal. The expanded metal parts 520 and 521 are formed in the same manner as the expanded metal part 120 according to the first embodiment. In this embodiment, the expanded metal parts 520 and 521 are formed by being stretched in the second direction so that openings (not shown) in the expanded metal appear open when viewed from a third direction (see arrow C5 in FIG. 17 , etc.) that is perpendicular to the first direction and perpendicular to the second direction. The extrusion direction used by the punch to expand the slits is perpendicular to the first direction and inclined relative to the second and third directions. In the expanded metal parts 520 and 521, multiple slits are arranged in a staggered pattern, and multiple openings (not shown) in the expanded metal are formed by expanding the staggered slits. Therefore, in the expanded metal portions 520 and 521, a plurality of expanded metal openings (not shown) are arranged at equal intervals in a row in the first direction, and these rows are arranged at equal intervals in a zigzag pattern in the second direction.

[0096] The suppression structure prevents the expanded metal portions 520, 521 from overlapping and nesting when the filter body 510 is wound. For example, "nested overlapping" refers to overlapping in a manner similar to that shown in FIG. 4 . If overlapping and nesting portions of the expanded metal portions 520, 521 occur when the filter body 510 is wound, the thickness of the filter 500 will become non-uniform and variations in the flow of gas and other substances passing through the filter 500 will occur. In the filter 500, the suppression structure prevents the expanded metal portions 520, 521 from overlapping and nesting when the filter body 510 is wound, thereby preventing non-uniform thickness of the filter 500 and variations in the flow of gas and other substances passing through the filter 500.

[0097] The suppression structure includes an arrangement structure in which the expanded metal portions 520, 521 are arranged so that the extrusion direction of the expanded metal portions 520, 521 of each layer of the filter body 510 intersects the extrusion direction of the expanded metal portions 520, 521 of adjacent layers when the filter body 510 is wound. The arrangement structure includes a structure in which multiple expanded metal portions 520, 521 are arranged in a stacked manner before the filter body 510 is wound. For example, the multiple expanded metal portions 520, 521 are arranged in a stacked manner so that the front sides or back sides of the multiple expanded metal portions 520, 521 butt against each other. Furthermore, the ends of the multiple overlapping expanded metal portions 520, 521 in the second direction may be fixed to each other by welding or the like.

[0098] As shown in (a) of Figure 18, the extrusion direction of each of the multiple expanded metal portions 520, 521 intersects with the extrusion direction of adjacent expanded metal portions among the multiple expanded metal portions 520, 521. Specifically, the extrusion direction of the expanded metal portion 520 (see arrow D5a in Figure 18) intersects with the extrusion direction of the adjacent expanded metal portion 521 (see arrow D5b in Figure 18). In this embodiment, the extrusion direction of the expanded metal portion 520 is symmetrical to the extrusion direction of the adjacent expanded metal portion 521. Therefore, the bond 523 of the expanded metal portion 520 is disposed symmetrically with the bond 525 of the expanded metal portion 521.

[0099] As shown in Figure 18 (b) , when the filter body 510 is wound, the multiple expanded metal portions 520, 521 overlap in the radial direction of the filter body 510 (see arrow E5 in Figure 18 , etc.). The extrusion direction of the expanded metal portion 520a of the first layer of the expanded metal portion 520 intersects with the extrusion direction of the expanded metal portion 521b of the second layer of the expanded metal portion 521 of the filter body 510. In this embodiment, the extrusion direction of the expanded metal portion 520a of the first layer is symmetrical with the extrusion direction of the expanded metal portion 521b of the second layer. Furthermore, when the filter body 510 is wound, the extrusion direction of the expanded metal portion 521b of the second layer of the expanded metal portion 521 of the filter body 510 intersects with the extrusion direction of the expanded metal portion 520c of the third layer of the expanded metal portion 520 of the filter body 510. In this embodiment, the extrusion direction of the second-layer expanded metal portion 521b is symmetrical to the extrusion direction of the third-layer expanded metal portion 520c. Furthermore, when the filter body 510 is wound, the extrusion direction of the third-layer expanded metal portion 520c of the expanded metal portion 520 intersects with the extrusion direction of the fourth-layer expanded metal portion 521d of the expanded metal portion 521. In this embodiment, the extrusion direction of the third-layer expanded metal portion 520c is symmetrical to the extrusion direction of the fourth-layer expanded metal portion 521d. When the filter body 510 is wound, each of the expanded metal portions 520, 521 extends in the winding direction of the filter body 510 (see arrow F5 in FIG. 18 , etc.).

[0100] As described above, the filter 500 in the fifth embodiment of the present invention described above includes a filter body 510 and is formed by winding the filter body 510. The filter body 510 has expanded metal portions 520, 521 made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal portions 520, 521 from overlapping in a nested state when the filter body 510 is wound.

[0101] This makes it possible to use expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal portions 520, 521 from overlapping in a nested state when the filter body 510 is wound around it. In other words, it is possible to prevent the expanded metal portions 520, 521 from overlapping in a nested state, and the filter 500 can be manufactured more easily.

[0102] Furthermore, in the filter 500 of the fifth embodiment of the present invention described above, the suppression structure includes an arrangement structure in which, when the filter body 510 is wound, the expanded metal portions 520, 521 are arranged so that the extrusion direction of the expanded metal portions 520, 521 of each layer of the filter body 510 intersects the extrusion direction of the expanded metal portions 520, 521 of the adjacent layers.

[0103] With this, the extrusion direction of the expanded metal portions 520, 521 of each layer intersects with the extrusion direction of the expanded metal portions 520, 521 of the adjacent layer, which more reliably prevents the expanded metal portions 520, 521 from overlapping in a nested state when the filter body 510 is wound.

[0104] Furthermore, in the filter 500 according to the fifth embodiment of the present invention described above, the arrangement structure includes a structure in which, before the filter body 510 is wound, multiple expanded metal sections 520, 521 are arranged in a stacked manner, and the extrusion direction of each of the multiple expanded metal sections 520, 521 intersects with the extrusion direction of adjacent expanded metal sections among the multiple expanded metal sections 520, 521.

[0105] According to this, before the filter body 510 is wound, the multiple expanded metal sections 520, 521 are arranged on top of each other so that the extrusion direction of each of the multiple expanded metal sections 520, 521 intersects the extrusion direction of adjacent expanded metal sections among the multiple expanded metal sections 520, 521.This makes it easier to ensure that, when the filter body 510 is wound, the extrusion direction of the expanded metal sections 520, 521 of each layer of the filter body 510 intersects the extrusion direction of the expanded metal sections 520, 521 of adjacent layers.

[0106] In the fifth embodiment described above, the case where two expanded metal parts 520, 521 are arranged in a stacked manner has been described, but the present invention is not limited to this. For example, three or more expanded metal parts may be arranged in a stacked manner.

[0107] In addition, in the above-described fifth embodiment, the state in which the end of the bond 523 contacts the end of the bond 525 adjacent in the direction of the arrow E5 is shown, but the end of the bond 523 does not necessarily need to contact the end of the bond 525. In other words, a gap may be formed in all or part between the end of the bond 523 and the end of the bond 525.

[0108] Sixth Embodiment A filter 600 according to a sixth embodiment of the present invention will now be described with reference to FIGS.

[0109] FIG. 19 is a perspective view showing a filter 600 according to a sixth embodiment of the present invention. FIG. 20 is a perspective view showing the filter 600 of FIG. 19 in a state before the filter body 610 is wound. FIG. 21 is an end view showing a portion of the filter 600 of FIG. 19. FIG. 21(a) shows an end surface of a portion of the filter body 610 cut in a direction perpendicular to the first direction before the filter body 610 is wound. FIG. 21(b) shows an end surface of a portion of the filter 600 cut in a direction perpendicular to the axial direction. In FIGS. 19 and 20, the expanded metal portions 620b and 620d are schematically indicated by cross-hatching. In addition, in FIGS. 19 and 20, the expanded metal portions 620a and 620c are not cross-hatched. The figures are schematic diagrams and are not necessarily drawn precisely. Therefore, the scales and the like do not necessarily match between the figures.

[0110] As shown in FIGS. 19 and 20 , the filter 600 includes a filter body 610 and is formed by winding the filter body 610. Before being wound, the filter body 610 extends in a first direction (see arrow A6 in FIG. 20 , etc.) and a second direction (see arrow B6 in FIG. 20 , etc.) perpendicular to the first direction. The filter 600 is formed by winding the filter body 610 around the first direction. In other words, the first direction is the axial direction of the filter body 610 when the filter body 610 is wound. Note that, hereinafter, the axial direction of the filter body 610 may be simply referred to as the axial direction. The filter body 610 includes expanded metal portions 620 a, 620 b, 620 c, and 620 d and a suppression structure that suppresses overlapping of the expanded metal portions 620 a, 620 b, 620 c, and 620 d when the filter body 610 is wound.

[0111] The expanded metal portions 620a, 620b, 620c, and 620d are made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction. In other words, the expanded metal portions 620a, 620b, 620c, and 620d are made of general expanded metal. The expanded metal portions 620a, 620b, 620c, and 620d are formed in the same manner as the expanded metal portion 120 according to the first embodiment. In this embodiment, the expanded metal portions 620a, 620b, 620c, and 620d are formed by being stretched in the second direction so that openings (not shown) in the expanded metal appear open when viewed from a third direction (see arrow C6 in FIG. 20 , etc.) that is perpendicular to the first direction and perpendicular to the second direction. The extrusion direction used by the punch to expand the slits is perpendicular to the first direction and inclined relative to the second and third directions. In expanded metal portions 620a, 620b, 620c, and 620d, multiple slits are arranged in a staggered pattern, and multiple expanded metal openings (not shown) are formed by expanding the staggered slits. Therefore, in expanded metal portions 620a, 620b, 620c, and 620d, multiple expanded metal openings (not shown) are arranged in rows at equal intervals in the first direction, and these rows are arranged in a zigzag pattern at equal intervals in the second direction.

[0112] The suppression structure prevents the expanded metal portions 620a, 620b, 620c, and 620d from overlapping and nesting when the filter body 610 is wound. For example, "nested overlapping" refers to overlapping in a manner similar to that shown in FIG. 4 . If overlapping and nesting portions of the expanded metal portions 620a, 620b, 620c, and 620d occur when the filter body 610 is wound, the thickness of the filter 600 will become non-uniform and variations in the flow of gas and other substances passing through the filter 600 will occur. In the filter 600, the suppression structure prevents the expanded metal portions 620a, 620b, 620c, and 620d from overlapping and nesting when the filter body 610 is wound, thereby preventing the thickness of the filter 600 from becoming non-uniform and variations in the flow of gas and other substances passing through the filter 600.

[0113] The suppression structure includes an arrangement structure in which the expanded metal portions 620a, 620b, 620c, and 620d are arranged so that the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d of each layer of the filter body 610 intersects the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d of adjacent layers when the filter body 610 is wound. The arrangement structure includes a structure in which, before the filter body 610 is wound, the multiple expanded metal portions 620a, 620b, 620c, and 620d are connected and arranged in a direction perpendicular to the thickness direction of the expanded metal portions 620a, 620b, 620c, and 620d. The thickness direction of the expanded metal portions 620a, 620b, 620c, and 620d is the thickness direction of the entire thickness of the expanded metal that constitutes the expanded metal portions 620a, 620b, 620c, and 620d, which is referred to as the third direction in this example. The multiple expanded metal portions 620a, 620b, 620c, and 620d are connected and arranged in the second direction. For example, the expanded metal portions 620b and 620d are arranged so that one side in the third direction is their front side, and the expanded metal portions 620a and 620c are arranged so that the other side in the third direction is their front side, and the multiple expanded metal portions 620a, 620b, 620c, and 620d are connected in this order in the second direction. Adjacent expanded metal portions of the plurality of expanded metal portions 620a, 620b, 620c, and 620d are fixed to each other by welding or the like.

[0114] As shown in FIG. 21A , the extrusion direction of each of the expanded metal portions 620a, 620b, 620c, and 620d intersects with the extrusion direction of adjacent expanded metal portions among the expanded metal portions 620a, 620b, 620c, and 620d. Specifically, the extrusion direction of the expanded metal portion 620a (see arrow D6a in FIG. 21 ) intersects with the extrusion direction of the adjacent expanded metal portion 620b (see arrow D6b in FIG. 21 ). In this embodiment, the extrusion direction of the expanded metal portion 620a is symmetrical to the extrusion direction of the adjacent expanded metal portion 620b. Therefore, the bond 623a of the expanded metal portion 620a is disposed symmetrically with the bond 623b of the expanded metal portion 620b. Furthermore, the extrusion direction of the expanded metal portion 620b intersects with the extrusion direction of the adjacent expanded metal portion 620c (see arrow D6c in FIG. 21 ). In this embodiment, the extrusion direction of the expanded metal portion 620b is symmetrical with the extrusion direction of the adjacent expanded metal portion 620c. Therefore, the bond 623b of the expanded metal portion 620b is disposed symmetrically with the bond 623c of the expanded metal portion 620c. Furthermore, the extrusion direction of the expanded metal portion 620c intersects with the extrusion direction of the adjacent expanded metal portion 620d (see arrow D6d in FIG. 21 ). In this embodiment, the extrusion direction of the expanded metal portion 620c is symmetrical with the extrusion direction of the adjacent expanded metal portion 620d. Therefore, the bond 623c of the expanded metal part 620c is disposed symmetrically to the bond 623d of the expanded metal part 620d.

[0115] 21(b), the filter body 610 is wound so that the expanded metal portion 620a constitutes the first layer of the filter body 610, the expanded metal portion 620b constitutes the second layer of the filter body 610, the expanded metal portion 620c constitutes the third layer of the filter body 610, and the expanded metal portion 620d constitutes the fourth layer of the filter body 610. When the filter body 610 is wound, the multiple expanded metal portions 620a, 620b, 620c, and 620d overlap in the radial direction of the filter body 610 (see arrow E6 in FIG. 21 etc.). When the filter body 610 is wound, each of the expanded metal portions 620a, 620b, 620c, and 620d extends in the winding direction of the filter body 610 (see arrow F6 in FIG. 21 etc.). When the filter body 610 is wound, the extrusion direction of the expanded metal portion 620a of the first layer of the filter body 610 intersects with the extrusion direction of the expanded metal portion 620b of the second layer of the filter body 610. In this embodiment, the extrusion direction of the expanded metal portion 620a of the first layer is symmetrical with the extrusion direction of the expanded metal portion 620b of the second layer. Furthermore, when the filter body 610 is wound, the extrusion direction of the expanded metal portion 620b of the second layer of the filter body 610 intersects with the extrusion direction of the expanded metal portion 620c of the third layer of the filter body 610. In this embodiment, the extrusion direction of the expanded metal portion 620b of the second layer is symmetrical with the extrusion direction of the expanded metal portion 620c of the third layer. Furthermore, when the filter body 610 is wound, the extrusion direction of the expanded metal portion 620c of the third layer of the filter body 610 intersects with the extrusion direction of the expanded metal portion 620d of the fourth layer of the filter body 610. In this embodiment, the extrusion direction of the expanded metal portion 620c of the third layer is symmetrical to the extrusion direction of the expanded metal portion 620d of the fourth layer.

[0116] As described above, the filter 600 in the sixth embodiment of the present invention described above includes a filter body 610 and is formed by winding the filter body 610. The filter body 610 has expanded metal portions 620a, 620b, 620c, and 620d made of expanded metal that is formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal portions 620a, 620b, 620c, and 620d from overlapping in a nested state when the filter body 610 is wound.

[0117] This allows for the use of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal portions 620a, 620b, 620c, and 620d from overlapping and nesting when the filter body 610 is wound around it. In other words, this prevents the expanded metal portions 620a, 620b, 620c, and 620d from overlapping and nesting, and allows for easier production of the filter 600.

[0118] Furthermore, in the filter 600 according to the sixth embodiment of the present invention described above, the suppression structure includes an arrangement structure in which, when the filter body 610 is wound, the expanded metal portions 620a, 620b, 620c, 620d are arranged so that the extrusion direction of the expanded metal portions 620a, 620b, 620c, 620d in each layer of the filter body 610 intersects the extrusion direction of the expanded metal portions 620a, 620b, 620c, 620d in the adjacent layers.

[0119] In this way, the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d of each layer intersects with the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d of the adjacent layers, which more reliably prevents the expanded metal portions 620a, 620b, 620c, and 620d from overlapping in a nested state when the filter body 610 is wound.

[0120] Furthermore, in the filter 600 according to the sixth embodiment of the present invention described above, the arrangement structure includes a structure in which, before the filter body 610 is wound, the multiple expanded metal portions 620a, 620b, 620c, and 620d are connected and arranged in a direction perpendicular to the thickness direction of the expanded metal portions 620a, 620b, 620c, and 620d, and the extrusion direction of each of the multiple expanded metal portions 620a, 620b, 620c, and 620d intersects the extrusion direction of adjacent expanded metal portions among the multiple expanded metal portions 620a, 620b, 620c, and 620d.

[0121] According to this, before the filter body 610 is wound, the multiple expanded metal portions 620a, 620b, 620c, and 620d are connected and arranged so that the extrusion direction of each of the multiple expanded metal portions 620a, 620b, 620c, and 620d intersects the extrusion direction of adjacent expanded metal portions among the multiple expanded metal portions 620a, 620b, 620c, and 620d.This makes it easier to ensure that, when the filter body 610 is wound, the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d in each layer of the filter body 610 intersects the extrusion direction of the expanded metal portions 620a, 620b, 620c, and 620d in the adjacent layers.

[0122] In the sixth embodiment described above, four expanded metal sections 620a, 620b, 620c, and 620d are connected to one another, but the present invention is not limited to this. For example, two expanded metal sections may be connected to one another, or five or more expanded metal sections may be connected to one another.

[0123] In the sixth embodiment described above, (a) the end of the bond 623a is in contact with the end of the bond 623b adjacent thereto in the direction of the arrow E6, (b) the end of the bond 623b is in contact with the end of the bond 623c adjacent thereto in the direction of the arrow E6, and (c) the end of the bond 623c is in contact with the end of the bond 623d adjacent thereto in the direction of the arrow E6 are shown, but the ends of the bonds 623a and 623b, the ends of the bonds 623b and 623c, and the ends of the bonds 623c and 623d do not necessarily have to be in contact with each other. That is, gaps may be formed in all or part between the ends of the bonds 623a and 623b, between the ends of the bonds 623b and 623c, and between the ends of the bonds 623c and 623d.

[0124] Seventh Embodiment A filter 700 according to a seventh embodiment of the present invention will now be described with reference to FIGS.

[0125] FIG. 22 is a perspective view showing a filter 700 according to a seventh embodiment of the present invention. FIG. 23 is a perspective view showing the filter body 710 of the filter 700 of FIG. 22 before it is wound. FIG. 24 is an end view showing a portion of the filter 700 of FIG. 22. FIG. 24 shows an end surface of a portion of the filter 700 cut in the radial direction. In FIGS. 22 to 24, expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are schematically indicated by cross-hatching. Furthermore, the figures are schematic diagrams and are not necessarily drawn to scale. Therefore, the scales and the like do not necessarily match in the figures.

[0126] As shown in Figures 22 and 23 , the filter 700 includes a filter body 710 and is formed by winding the filter body 710. Before being wound, the filter body 710 extends in a first direction (see arrow A7 in Figure 23 etc.) and a second direction (see arrow B7 in Figure 23 ) perpendicular to the first direction. The filter 700 is formed by winding the filter body 710 around the first direction. In other words, the first direction is the axial direction of the filter body 710 when the filter body 710 is wound. Note that, hereinafter, the axial direction of the filter body 710 may be simply referred to as the axial direction. The filter body 710 includes expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e, and a suppression structure that prevents the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping in a nested state when the filter body 710 is wound.

[0127] The expanded metal parts 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction. In other words, the expanded metal parts 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are made of general expanded metal. The expanded metal parts 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are formed in the same manner as the expanded metal part 120 according to the first embodiment.

[0128] In this embodiment, the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are formed by being stretched in the second direction so that openings (not shown) in the expanded metal appear open when viewed from a third direction (see arrow C7 in FIG. 23 ) that is perpendicular to both the first and second directions. The extrusion direction used by the punch to widen the slits is perpendicular to the first direction and inclined relative to the second and third directions. In the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e, multiple slits are arranged in a staggered pattern, and multiple openings (not shown) in the expanded metal are formed by widening the staggered slits. Therefore, in expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e, a plurality of expanded metal openings (not shown) are arranged at equal intervals in a row in the first direction, and these rows are arranged at equal intervals in a zigzag pattern in the second direction. The filter body 710 is wound so that expanded metal portions 720a and 722a form the first layer of the filter body 710, expanded metal portion 721b forms the second layer of the filter body 710, expanded metal portions 720c and 722c form the third layer of the filter body 710, expanded metal portion 721d forms the fourth layer of the filter body 710, and expanded metal portions 720e and 722e form the fifth layer of the filter body 710. When the filter body 710 is wound, the multiple expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e overlap in the radial direction (see arrow E7 in Figure 22 etc.) of the filter body 710. When the filter body 710 is wound, each of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e extends in the winding direction of the filter body 710 (see arrow F7 in Figure 22 ).

[0129] The suppression structure prevents the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping and nesting when the filter body 710 is wound. For example, overlapping and nesting refers to an overlapping state similar to that shown in Figure 4. If overlapping and nesting portions occur in this manner when the filter body 710 is wound, the thickness of the filter 700 will become uneven and variations will occur in the flow of gas and other substances passing through the filter 700. In filter 700, the suppression structure prevents expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping and nesting when filter body 710 is wound, thereby preventing the thickness of filter 700 from becoming uneven and preventing variations in the flow of gas or the like passing through filter 700.

[0130] The suppression structure includes an arrangement structure in which, when the filter body 710 is wound, the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are arranged so that the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e in each layer of the filter body 710 in the axial direction of the filter body 710 are different from the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e in adjacent layers.

[0131] 24 , the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e in each layer of the filter body 710 are positioned in the axial direction differently from the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e in adjacent layers. Specifically, the axial positions of the expanded metal portions 720a and 722a in the first layer of the filter body 710 are different from the axial position of the expanded metal portion 721b in the second layer of the filter body 710. The expanded metal portions 720a and 722a do not overlap with the expanded metal portion 721b in the radial direction. The axial position of the expanded metal portion 721b of the second layer of the filter body 710 is different from the axial positions of the expanded metal portions 720c and 722c of the third layer of the filter body 710. The expanded metal portion 721b does not overlap with the expanded metal portions 720c and 722c in the radial direction. The axial position of the expanded metal portions 720c and 722c of the third layer of the filter body 710 is different from the axial position of the expanded metal portion 721d of the fourth layer of the filter body 710. The expanded metal portions 720c and 722c do not overlap with the expanded metal portion 721d in the radial direction. The axial position of the expanded metal portion 721d of the fourth layer of the filter body 710 is different from the axial positions of the expanded metal portions 720e and 722e of the fifth layer of the filter body 710. The expanded metal portion 721d does not overlap with the expanded metal portions 720e and 722e in the radial direction.

[0132] In this embodiment, the expanded metal portions 720a, 720c, and 720e are located at the same axial positions, and the expanded metal portions 720a and 720c overlap with a radial gap 740b between them, while the expanded metal portions 720c and 720e overlap with a radial gap 740d between them. The expanded metal portions 721b and 721d are located at the same axial positions, and the expanded metal portions 721b and 721d overlap with a radial gap 741c between them. The expanded metal portions 722a, 722c, and 722e are located at the same axial positions, and the expanded metal portions 722a and 722c overlap with a radial gap 742b between them, while the expanded metal portions 722c and 722e overlap with a radial gap 742d between them.

[0133] 23 , before the filter body 710 is wound, expanded metal portions 720 a, 722 a, 721 b, 720 c, 722 c, 721 d, and 720 e, 722 e are aligned in this order in the second direction. In the first direction, the positions of expanded metal portions 720 a, 720 c, and 720 e are different from the positions of expanded metal portions 721 b and 721 d, and the positions of expanded metal portions 722 a, 722 c, and 722 e.

[0134] The suppression structure has plate-shaped portions 736a, 736b, 736c, 736d, 736e, and 736f. Plate-shaped portion 736a is attached to the side of expanded metal portions 720a and 722a opposite to expanded metal portion 721b, connecting expanded metal portions 720a and 722a. Plate-shaped portion 736b is attached between expanded metal portions 720a and 722a and expanded metal portion 721b, connecting expanded metal portions 720a, 721b, and 722a. Plate-shaped portion 736c is attached between expanded metal portion 721b and expanded metal portions 720c and 722c, connecting expanded metal portions 720c, 721b, and 722c. Furthermore, a plate-shaped portion 736d is attached between expanded metal portions 720c, 722c and expanded metal portion 721d, connecting expanded metal portions 720c, 721d, and 722c. A plate-shaped portion 736e is attached between expanded metal portion 721d and expanded metal portions 720e, 722e, connecting expanded metal portions 720e, 721d, and 722e. A plate-shaped portion 736f is attached to the side of expanded metal portions 720e and 722e opposite to the side facing expanded metal portion 721d, connecting expanded metal portions 720e and 722e. Plate-shaped portions 736a, 736b, 736c, 736d, 736e, and 736f do not have openings. The filter 700 as described above can be formed by winding the filter body 710 around in the first direction so that the plate-like portions 736a, 736b, 736c, 736d, 736e, and 736f overlap in this order in the radial direction.

[0135] As described above, filter 700 in the seventh embodiment of the present invention described above includes filter body 710 and is a filter formed by winding filter body 710. Filter body 710 has expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping in a nested state when filter body 710 is wound.

[0136] This allows for the use of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping and nesting when the filter body 710 is wound around it. In other words, this prevents the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping and nesting, and allows for easier production of the filter 700.

[0137] Furthermore, in the filter 700 of the seventh embodiment of the present invention described above, the suppression structure includes an arrangement structure in which the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are arranged so that, when the filter body 710 is wound, the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e of each layer of the filter body 710 are different from the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e of adjacent layers in the axial direction of the filter body 710.

[0138] With this, the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e of each layer of the filter body 710 in the axial direction of the filter body 710 are different from the positions of the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e of adjacent layers, which more reliably prevents the expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e from overlapping in a nested state when the filter body 710 is wound.

[0139] In the seventh embodiment described above, the case where five layers of expanded metal portions 720a, 720c, 720e, 721b, 721d, 722a, 722c, and 722e are provided is described, but the present invention is not limited to this. For example, two to four layers of expanded metal portions may be provided, or six or more layers of expanded metal portions may be provided.

[0140] Eighth Embodiment A filter 800 according to an eighth embodiment of the present invention will now be described with reference to FIGS. 25 and 26. FIG.

[0141] Fig. 25 is a perspective view showing a filter 800 according to an eighth embodiment of the present invention. Fig. 26 is a perspective view showing the filter body 810 of the filter 800 of Fig. 25 before it is wound. In Figs. 25 and 26, the expanded metal portion 820 is indicated by cross-hatching. Furthermore, each figure is a schematic view and is not necessarily an accurate representation. Therefore, the scales and the like do not necessarily match in each figure.

[0142] As shown in FIGS. 25 and 26 , the filter 800 includes a filter body 810 and is formed by winding the filter body 810. Before being wound, the filter body 810 extends in a first direction (see arrow A8 in FIG. 26 , etc.) and a second direction (see arrow B8 in FIG. 26 ) perpendicular to the first direction. The filter 800 is formed by winding the filter body 810 around the first direction. In other words, the first direction is the axial direction of the filter body 810 when the filter body 810 is wound. Note that, hereinafter, the axial direction of the filter body 810 may be simply referred to as the axial direction. The filter body 810 includes an expanded metal portion 820 and a suppression structure that suppresses overlapping of the expanded metal portion 820 when the filter body 810 is wound.

[0143] The expanded metal part 820 is made of expanded metal formed by expanding multiple staggered slits in the extrusion direction. In other words, the expanded metal part 820 is made of a general expanded metal. The expanded metal part 820 is formed in the same manner as the expanded metal part 120 according to the first embodiment. In this embodiment, the expanded metal part 820 is formed by being stretched in the second direction so that openings (not shown) of the expanded metal appear open when viewed from a third direction (see arrow C8 in FIG. 26 ) that is perpendicular to the first direction and perpendicular to the second direction. The extrusion direction, in which the punch is used to expand the slits, is perpendicular to the first direction and inclined relative to the second and third directions. In the expanded metal part 820, multiple slits are arranged in a staggered pattern, and multiple openings (not shown) of the expanded metal are formed by expanding the staggered slits. Therefore, in the expanded metal section 820, a plurality of expanded metal openings (not shown) are arranged at equal intervals in a row in the first direction, and these rows are arranged at equal intervals in a zigzag pattern in the second direction.

[0144] The suppression structure prevents the expanded metal portions 820 from overlapping and nesting when the filter body 810 is wound. For example, "nested overlapping" refers to overlapping in a manner similar to that shown in FIG. 4 . If overlapping and nesting portions of the expanded metal portions 820 occur when the filter body 810 is wound, the thickness of the filter 800 will become non-uniform and variations in the flow of gas and other substances passing through the filter 800 will occur. In the filter 800, the suppression structure prevents the expanded metal portions 820 from overlapping and nesting when the filter body 810 is wound, thereby preventing variations in the thickness of the filter 800 and variations in the flow of gas and other substances passing through the filter 800.

[0145] The suppression structure includes an arrangement structure in which the expanded metal portion 820 is arranged so that the extrusion direction of the expanded metal portion 820 of each layer of the filter body 810 intersects the extrusion direction of the expanded metal portion 820 of an adjacent layer when the filter body 810 is wound. The arrangement structure includes a structure in which the expanded metal portion 820 is folded back and arranged before the filter body 810 is wound. The expanded metal portion 820 is folded back at the center around the second direction.

[0146] The extrusion direction of the expanded metal part 820 on one side of the center intersects with the extrusion direction of the part on the other side of the center, specifically, in a state similar to that shown in FIG.

[0147] When the filter body 810 is wound, the portion on one side and the portion on the other side overlap in the radial direction of the filter body 810 (see arrow E8 in FIG. 25 ). Specifically, the portion on one side and the portion on the other side overlap in a state similar to that shown in (b) of FIG. 18 . When the filter body 810 is wound, each of the portion on one side and the portion on the other side extends in the winding direction of the filter body 810 (see arrow F8 in FIG. 25 ).

[0148] As described above, the filter 800 in the above-described eighth embodiment of the present invention is a filter that includes a filter body 810 and is formed by winding the filter body 810. The filter body 810 has an expanded metal section 820 made of expanded metal that is formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal sections 820 from overlapping in a nested state when the filter body 810 is wound.

[0149] This makes it possible to use expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, while preventing the expanded metal portions 820 from overlapping in a nested state when the filter body 810 is wound around it. In other words, it is possible to prevent the expanded metal portions 820 from overlapping in a nested state, and the filter 800 can be manufactured more easily.

[0150] Furthermore, in the filter 800 of the eighth embodiment of the present invention described above, the suppression structure includes an arrangement structure in which, when the filter body 810 is wound, the expanded metal portions 820 are arranged so that the extrusion direction of the expanded metal portions 820 of each layer of the filter body 810 intersects the extrusion direction of the expanded metal portions 820 of adjacent layers.

[0151] In this way, the extrusion direction of the expanded metal portion 820 of each layer intersects with the extrusion direction of the expanded metal portion 820 of the adjacent layer, which more reliably prevents the expanded metal portions 820 from overlapping in a nested state when the filter body 810 is wound.

[0152] In the eighth embodiment described above, the expanded metal part 820 is folded in half, but the present invention is not limited to this. For example, the expanded metal part may be folded in an accordion-like manner.

[0153] Ninth Embodiment Hereinafter, with reference to FIG. 27, a gas generator 1000 according to a ninth embodiment of the present invention will be described.

[0154] FIG. 27 is a schematic cross-sectional view showing a gas generator 1000 according to a ninth embodiment of the present invention.

[0155] 27 , gas generator 1000 is a short, generally cylindrical, disk-shaped gas generator, and includes a housing, a holding portion 30, igniter 40, cup-shaped member 50, lower support member 70, upper support member 80, cushion material 85, and filter 500. An accommodating space provided inside the housing accommodates internal components such as a part of holding portion 30, igniter 40, cup-shaped member 50, transfer charge 59, gas generating agent 61, lower support member 70, upper support member 80, cushion material 85, and filter 500. A combustion chamber 60 that mainly accommodates gas generating agent 61 out of the above-mentioned internal components is located in the accommodating space provided inside the housing.

[0156] The housing is a short, generally cylindrical body with one axial end and the other axial end closed. The housing includes a lower shell 10 and an upper shell 20. The lower shell 10 and the upper shell 20 are each formed as a press-molded product, for example, by pressing a rolled metal plate-like member. The metal plate-like members constituting the lower shell 10 and the upper shell 20 are made of metal plates made of, for example, stainless steel, iron steel, aluminum alloy, stainless alloy, etc., and preferably so-called high-tensile steel plates that do not break or otherwise undergo damage even when a tensile stress of 440 MPa or more and 780 MPa or less is applied.

[0157] The lower shell 10 and the upper shell 20 are each formed in a generally cylindrical shape with a bottom, and are assembled and joined together with their open surfaces facing each other to form a housing. The lower shell 10 has a bottom plate portion 11 and a peripheral wall portion 12, and the upper shell 20 has a top plate portion 21 and a peripheral wall portion 22. The peripheral wall portion 12 extends from the outer peripheral edge of the bottom plate portion 11 toward the upper shell 20. The peripheral wall portion 22 extends from the outer peripheral edge of the top plate portion 21 toward the lower shell 10.

[0158] The upper end of the peripheral wall 12 of the lower shell 10 is inserted into the lower end of the peripheral wall 22 of the upper shell 20 and press-fitted. Furthermore, the peripheral wall 12 of the lower shell 10 and the peripheral wall 22 of the upper shell 20 are joined at or near their contact point, thereby fixing the lower shell 10 and the upper shell 20 together. Here, electron beam welding, laser welding, friction welding, or the like can be suitably used to join the lower shell 10 and the upper shell 20 together.

[0159] As a result, the portion of the peripheral wall of the housing closer to the bottom plate 11 is formed by the peripheral wall 12 of the lower shell 10, and the portion of the peripheral wall of the housing closer to the top plate 21 is formed by the peripheral wall 22 of the upper shell 20. One end and the other end in the axial direction of the housing are closed by the bottom plate 11 of the lower shell 10 and the top plate 21 of the upper shell 20, respectively.

[0160] The igniter 40 is for generating a flame and includes an ignition portion 41 and a pair of terminal pins 42. The igniter 40 ignites and burns the gas generating agent 61. The ignition portion 41 is disposed inside the housing and is ignited by the flow of electric current. The ignition portion 41 includes an ignition charge that ignites and burns to generate a flame when activated, and a resistor for igniting the ignition charge. The pair of terminal pins 42 are a pair of terminal pins for passing electric current through the ignition portion 41. The pair of terminal pins 42 are connected to the ignition portion 41 to ignite the ignition charge. The pair of terminal pins 42 extend to the outside of the housing through the opening 15.

[0161] More specifically, the ignition unit 41 comprises a cup-shaped squib cup and a plug that closes the open end of the squib cup and through which a pair of terminal pins 42 are inserted and held; a resistor (bridge wire) is attached so as to connect the tips of the pair of terminal pins 42 inserted into the squib cup; and an ignition charge is loaded into the squib cup so as to surround or be adjacent to the resistor.

[0162] Here, nichrome wire or the like is generally used as the resistor, and ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), lead tricinate, etc. are generally used as the ignition charge. The squib cup and plug are generally made of metal or plastic.

[0163] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 42. This current flow generates Joule heat in the resistor, causing the ignition charge to begin burning. The high-temperature flame generated by the combustion ruptures the squib cup containing the ignition charge. The time from when the current flows through the resistor to when the igniter 40 is activated is generally 2 ms or less when nichrome wire is used for the resistor.

[0164] Igniter 40 is attached to bottom plate 11 in a state where it is inserted from the inside of lower shell 10 so that terminal pin 42 passes through opening 15 provided in protruding cylindrical portion 13. Specifically, holding portion 30 made of a resin molded portion is provided around protruding cylindrical portion 13 provided on bottom plate 11, and igniter 40 is fixed to bottom plate 11 by being held by holding portion 30.

[0165] The gas generating agent 61 is an agent that is ignited by thermal particles generated by the transfer charge 59 when the igniter 40 is activated, and burns to generate gas. A non-azide gas generating agent is preferably used as the gas generating agent 61, and the gas generating agent 61 is generally formed as a molded body containing a fuel, an oxidizer, and an additive.

[0166] The fuel may be, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof. Specifically, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, or the like is preferably used.

[0167] Examples of oxidizing agents that can be used include basic metal nitrates such as basic copper nitrate, basic metal carbonates such as basic copper carbonate, perchlorates such as ammonium perchlorate and potassium perchlorate, and nitrates containing cations selected from alkali metals, alkaline earth metals, transition metals, and ammonia. Suitable nitrates include sodium nitrate and potassium nitrate.

[0168] Examples of additives include binders, slag formers, and combustion modifiers. Suitable binders include organic binders such as polyvinyl alcohol, metal salts of carboxymethyl cellulose, and stearates, as well as inorganic binders such as synthetic hydrotalcite and acid clay. Other suitable binders include polysaccharide derivatives such as hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, microcrystalline cellulose, guar gum, polyvinylpyrrolidone, polyacrylamide, and starch, as well as inorganic binders such as molybdenum disulfide, talc, bentonite, diatomaceous earth, kaolin, and alumina. Suitable slag formers include silicon nitride, silica, and acid clay. Suitable combustion modifiers include metal oxides, ferrosilicon, activated carbon, and graphite.

[0169] The shape of the molded body of the gas generating agent 61 may be various, such as granular, pellet-like, cylindrical, or other granular shapes, or disk-like shapes. Furthermore, for cylindrical molded bodies, perforated molded bodies having through holes inside the molded body (for example, a single-hole cylindrical shape or a multi-hole cylindrical shape) are also used. These shapes are preferably selected as appropriate depending on the specifications of the airbag device in which the gas generator 1000 is incorporated, and it is preferable to select an optimal shape depending on the specifications, such as a shape in which the gas generation rate changes over time during combustion of the gas generating agent 61. Furthermore, in addition to the shape of the gas generating agent 61, it is preferable to select the size and filling amount of the molded body as appropriate, taking into consideration the burning rate, pressure exponent, etc. of the gas generating agent 61.

[0170] The filter 500 functions as a cooling means for cooling the gas generated in the combustion chamber 60 by removing the high-temperature heat of the gas as the gas passes through the filter 500, and also functions as a removal means for removing residue (slag) and the like contained in the gas. Therefore, in order to sufficiently cool the gas and prevent the residue from being released to the outside, it is necessary to ensure that the gas generated in the combustion chamber 60 passes through the filter 500. The filter 500 is disposed at a distance from the peripheral wall 22 of the upper shell 20 that constitutes a part of the peripheral wall of the housing, so that a gap 28 of a predetermined size is formed between the filter 500 and the peripheral wall 22.

[0171] A plurality of gas outlets 23 are provided in the peripheral wall 22 of the upper shell 20 in a portion facing the filter 500. The gas outlets 23 are for guiding the gas that has passed through the filter 500 to the outside of the housing.

[0172] Additionally, a metal sealing tape 24 is attached to the inner peripheral surface of the peripheral wall portion 22 of the upper shell 20 as a sealing member to close the plurality of gas ejection ports 23. This sealing tape 24 can be suitably made of aluminum foil with an adhesive applied to one side, or the like, and the sealing tape 24 ensures that the combustion chamber 60 is airtight.

[0173] As explained above, the gas generator 1000 in the ninth embodiment of the present invention described above comprises gas generating agent 61 that generates gas by combustion, igniter 40 that ignites and burns the gas generating agent 61, filter 500 through which the gas passes, and a housing that has a gas outlet 23 that ejects the gas that has passed through filter 500 and that accommodates gas generating agent 61, igniter 40, and filter 500.

[0174] This provides the same effects as those of the filter 500 described above.

[0175] In the above-described ninth embodiment, a case has been described in which gas generator 1000 includes filter 500, but the present invention is not limited to this. For example, the gas generator may include any of filters 100, 200, 300, 400, 600, 700, and 800, instead of filter 500.

[0176] Furthermore, in the above-described ninth embodiment, the case where gas generator 1000 is a disk-type gas generator has been described, but the present invention is not limited to this. For example, the gas generator may be a long, substantially cylindrical cylinder-type gas generator or the like.

[0177] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and the specific configurations and the like can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention.

[0178] DESCRIPTION OF SYMBOLS 1 Plate material 2 Punch 10 Lower shell 11 Bottom plate portion 12 Peripheral wall portion 13 Projecting tube portion 15, 124 Opening 20 Upper shell 21 Top plate portion 22 Peripheral wall portion 23 Gas outlet 24 Sealing tape 28 Gap portion 30 Holding portion 40 Igniter 41 Igniter portion 42 Terminal pin 50 Cup-shaped member 59 Transfer charge 60 Combustion chamber 61 Gas generating agent 70 Lower support member 80 Upper support member 85 Cushion material 100, 200, 300, 400, 500, 600, 700, 800 Filter 110, 210, 310, 410, 510, 610, 710, 810 Filter body 120, 120a, 120b, 120c, 220, 220a, 220b, 220c, 221, 221a, 221b, 221c, 222, 222a, 222b , 222c, 320, 320a, 320b, 320c, 321, 321a, 321b, 321c, 322, 322a, 322b, 322c, 420, 420 a, 420b, 420c, 421, 421a, 421b, 421c, 422, 422a, 422b, 422c, 520, 520a, 520c, 521, 52 1b, 521d, 620a, 620b, 620c, 620d, 720a, 720c, 720e, 721b, 721d, 722a, 722c, 722e, 820 Expanded metal portion 123, 523, 525, 623a, 623b, 623c, 623d Bond 130, 130a, 130b, 130c, 131, 131a, 131b, 131c Folded portion 132, 132a, 132b, 132c, 133, 133a, 133b, 133c Contact portion 140b, 140c, 240a, 240b, 241a, 241b, 242a, 242b, 340a, 340b, 341a, 341b, 342a, 342b, 440a, 440b, 441a, 441b, 442a, 442b, 740b, 740d, 741c, 742b, 742d gaps 210A, 310A, 410A first layer 210B, 310B, 410B second layer 210C, 310C, 410C third layer 234, 234a, 234b, 234c, 235, 235a, 235b, 235c, 334, 334a, 334b, 334c, 335, 335a, 335b, 335c, 434, 434a, 434b, 434c,435, 435a, 435b, 435c Protruding portions 736a, 736b, 736c, 736d, 736e, 736f Plate-shaped portions 1000 Gas generator,

Claims

1. A filter comprising a filter body and formed by winding the filter body, wherein the filter body has an expanded metal section made of expanded metal formed by expanding a plurality of staggered slits in the extrusion direction, and a suppression structure that suppresses the expanded metal sections from overlapping in a nested state when the filter body is wound.

2. The filter according to claim 1, characterized in that the suppression structure includes a gap-forming structure that forms a gap in the radial direction of the filter body so that the expanded metal sections overlap with a gap when the filter body is wound.

3. The filter described in claim 2, characterized in that the gap-forming structure has a folded portion formed by folding back the axial end of the filter body to one side in the radial direction in each of one or more layers of the filter body when the filter body is wound, and the folded portion of each of the one or more layers forms the gap so as to be adjacent to the folded portion in the axial direction.

4. The filter described in claim 2, characterized in that the gap-forming structure has a protrusion in each of one or more layers of the filter body that extends in the winding direction of the filter body, protrudes to one side in the radial direction, and contacts an adjacent layer on that side in the radial direction when the filter body is wound, and the protrusion of each of the one or more layers forms the gap so as to be adjacent to the protrusion in the axial direction of the filter body.

5. A filter according to claim 1, characterized in that the suppression structure includes an arrangement structure in which the expanded metal portions are arranged so that, when the filter body is wound, the extrusion direction of the expanded metal portion of each layer of the filter body intersects with the extrusion direction of the expanded metal portion of an adjacent layer.

6. The filter described in claim 5, characterized in that the arrangement structure includes a structure in which a plurality of the expanded metal sections are arranged in a stacked manner before the filter body is wound, and the extrusion direction of each of the plurality of expanded metal sections intersects with the extrusion direction of adjacent expanded metal sections among the plurality of expanded metal sections.

7. The filter described in claim 5, characterized in that the arrangement structure includes a structure in which, before the filter body is wound, a plurality of the expanded metal sections are connected and arranged in a direction perpendicular to the thickness direction of the expanded metal sections, and the extrusion direction of each of the plurality of expanded metal sections intersects with the extrusion direction of adjacent ones of the plurality of expanded metal sections.

8. A filter as described in claim 1, characterized in that the suppression structure includes an arrangement structure in which the expanded metal portions are arranged so that, when the filter body is wound, the position of the expanded metal portion of each layer of the filter body in the axial direction of the filter body is different from the position of the expanded metal portion of an adjacent layer.

9. A gas generator comprising: a gas generating agent that generates gas through combustion; an igniter that ignites and burns the gas generating agent; a filter according to any one of claims 1 to 8 through which the gas passes; and a housing that has a gas outlet for ejecting the gas that has passed through the filter and that contains the gas generating agent, the igniter, and the filter.

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