Winding, method for manufacturing winding, welding electrode and manufacturing device

Abstract

Without increasing the number of manufacturing steps, a winding configured to prevent an end portion of a metal wire from damaging other components and the like is manufactured by making a distance from a welded portion to an end edge as short as possible, and a defective winding is prevented from being manufactured. The winding is a porous winding (filter 10) formed by winding at least one continuous metal wire 20 in a spiral and multi-layer manner. During winding, a terminal portion 30 (metal wire portion 20n) of the metal wire is resistance spot-welded to another portion (metal wire portion 20m) of the metal wire, and fusion cutting is performed at the welded portion. The tip section (30) (metal wire portion (20n)) has a melted and solidified section (31n) in which the entire metal wire in the width direction is melted and then solidified.

Description

Technical Field

[0001] The present invention relates to a porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, a method for manufacturing the winding, a welding electrode suitable for manufacturing the winding, and a manufacturing device having the welding electrode. Background Art

[0002] A porous winding having a hollow cylindrical shape formed by winding at least one continuous metal wire in a spiral and multi-layer manner has been used as a filter for removing foreign matter larger than a predetermined size from a fluid and for purposes such as cooling the fluid.

[0003] Patent Document 1 is mentioned as a document describing such a winding.

[0004] In the above-mentioned winding, the end portion of the winding end side of the metal wire needs to be fixed to an appropriate portion of the winding by welding or the like, and the metal wire needs to be cut.

[0005] Reference List

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-171472 Summary of the invention

[0008] Technical issues

[0009] Here, the terminal edge (cut end) of the metal wire is preferably as close to the welding portion as possible. When the terminal edge of the metal wire is separated from the welding portion to a large extent, the following problems may occur. As an example of a problem, the portion of the metal wire from the welding portion to the terminal edge may get stuck on other parts, etc. to damage other parts, etc. As another example of a problem, when the distance from the welding portion to the terminal edge is long, the welding portion is easily peeled off.

[0010] If pliers, scissors, or the like are used as a tool for cutting the metal wire, the cutting blade needs to be operated in a direction intersecting the longitudinal direction of the metal wire. When cutting, since the cutting blade is inserted between the metal wire and the winding, the distance of the metal wire portion from the welding portion to the end edge becomes longer, and the metal wire portion tends to rise toward the outer diameter side due to the insertion of the cutting blade. Therefore, in order to prevent the above-mentioned problem, post-processing for shortening the length of the metal wire portion from the welding portion to the end edge is required, which increases the number of manufacturing steps.

[0011] Further, in order to shorten the length of the metal wire portion from the welded portion to the end edge, it is conceivable to cut the metal wire by repeatedly folding it in a direction intersecting the longitudinal direction at a position very close to the welded portion. However, in this method, the cut portion is easily deformed in the folding direction and work-hardened, so that the problem of the metal wire portion damaging other parts cannot be solved. In addition, this method is cumbersome as a cutting method.

[0012] Patent Document 1 describes welding the end portion of the winding end of the metal wire, but does not describe a cutting step of cutting the end portion of the winding end.

[0013] The present invention has been made in view of the above circumstances, and an object thereof is to provide a winding in which the distance from a welded portion to a terminal edge is made as short as possible without increasing the number of manufacturing steps.

[0014] Solution to the problem

[0015] In order to solve the above problems, the present invention provides a porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein the end portion of the metal wire is resistance spot welded to another portion of the metal wire and is melt-cut at the welded portion.

[0016] Advantageous Effects of the Invention

[0017] According to the present invention, it is possible to provide a winding in which the distance from the welded portion to the terminal edge is made as short as possible without increasing the number of manufacturing steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] [ Figure 1 ] Figure 1 is a schematic perspective view of a filter according to an embodiment of the present invention.

[0019] [ Figure 2 ] Figure 2 is a schematic diagram showing the state of the end portion of the filter, wherein Figure 2 (a) is a cross-sectional view of the end portion of the metal wire taken along the longitudinal direction, and Figure 2 (b) is a perspective view of the filter viewed from the outer diameter side.

[0020] [ Figure 3 ] Figure 3 is a diagram showing the vicinity of the end portion of the filter in a real photograph.

[0021] [ Figure 4 ] Figure 4 1 is a diagram mainly and schematically showing a winding arrangement in a winding manufacturing device.

[0022] [ Figure 5 ] Figure 5 1 is a diagram specifically and schematically showing the downstream side of the guide member in the winding manufacturing device.

[0023] [ Figure 6 ] Figure 6 is a perspective view showing an example of an electrode.

[0024] [ Figure 7 ] Figure 7 (a) and Figure 7 (b) is a plan view for explaining the relationship between the electrode tip end surface and the metal wire material contacting the electrode tip end surface.

[0025] [ Figure 8 ] Figure 8 (a) and Figure 8 (b) is a schematic diagram showing the state of the metal wire before being cut.

[0026] [ Fig. 9 ] Fig. 9 (a) and Fig. 9 (b) is a schematic diagram showing the state of the metal wire before being cut.

[0027] [ Fig.10 ] Fig.10 (a) and Fig.10 (b) is a schematic diagram showing the state of the metal wire before being cut. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below using the embodiments shown in the accompanying drawings. Note that the constituent elements, types, combinations, shapes, relative arrangements thereof, etc. described in the embodiments are not intended to limit the scope of the present invention only thereto, and are merely illustrative examples unless otherwise specified. In addition, as long as there is no contradiction, the configurations described in each embodiment may be performed when they are combined with each other.

[0029] [General shape of filter]

[0030] Figure 1 is a schematic perspective view of a filter according to an embodiment of the present invention.

[0031] The hollow cylindrical filter 10 according to an embodiment of the present invention is formed by spiraling at least one continuous metal wire 20 into multiple layers at a certain pitch so as to have a certain inclination angle relative to the axial direction (the up and down direction in the figure). The filter 10 is an example of a porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner. Here, the corresponding layers of the metal wire 20 wound in the same direction are referred to as wire layers L1, L2, L3, ... . In the front view, the metal wires constituting each metal wire layer L1, L2, L3, ... extend in the same direction inclined relative to the axial direction (center axis Ax1) of the hollow cylindrical filter, and the metal wires constituting the corresponding metal wire layers adjacent to each other in the direction toward the inner diameter side or the outer diameter side extend in directions intersecting each other (directions not parallel to each other).

[0032] Composed in Figure 1 The extension direction of the metal wire portion 20(n) (whose thickness is not shown in the drawing) of the wire layer Ln (n is a natural number) on the outermost layer (the longitudinal direction of the metal wire portion 20(n)) is the direction indicated by the solid arrow, and the extension direction of the metal wire portion 20(n-1) of the wire layer Ln-1 constituting the inside of the metal wire portion 20(n) (the longitudinal direction of the metal wire portion 20(n-1)) is the direction indicated by the dotted arrow.

[0033] n is set to about 20-20000 (corresponding to about 10-10000 reciprocations).

[0034] That is, the filter 10 includes: a wire layer (for example, wire layer L1) formed by spirally winding a metal wire 20 at a certain inclination angle relative to the axial direction; and another wire layer (for example, wire layer L2) formed by spirally winding a metal wire at an inclination angle different from the inclination angle of the metal wire constituting the wire layer L1 so as to overlap with the outer peripheral side of the wire layer L1. The metal wires constituting the wire layer L1 and the other wire layer L2 adjacent to the wire layer L1 are arranged not parallel to the axial direction and intersecting each other.

[0035] The filter 10 may also be configured such that the inclination angle of the metal wires constituting the wire layer with respect to the axial direction varies in the wire layer.

[0036] The filter 10 is used to remove unnecessary substances from various types of fluids (such as liquids and gases), and is used to cool the fluid passing through the filter at the same time according to the purpose of use (such as an airbag inflator for a car). First, the filter is configured to form a fluid path, which is passed by the fluid in the direction in which the wire layers overlap each other (i.e., the radial direction of the filter (the direction in which the wire layers overlap)). The fluid can pass through the filter from the inner diameter side to the outer diameter side or from the outer diameter side to the inner diameter side. Here, the radial direction does not necessarily strictly refer to the diameter direction (radial direction), but refers to the approximate radial direction relative to the axial direction and the circumferential direction.

[0037] The dimensions of the filter (such as the inner diameter, the outer diameter, and various dimensions in the axial direction) are appropriately determined according to the arrangement and dimensions of the device in which the filter is incorporated.

[0038] As the type of metal used as the material of the filter, there can be mentioned iron, steel, mild steel, stainless steel, nickel alloy, copper alloy, titanium alloy, aluminum alloy, etc. As the type of metal, the best metal for the purpose of the filter is selected.

[0039] The thickness and cross-sectional shape (cross-sectional shape in a direction orthogonal to the longitudinal direction of the metal wire) of the metal wire to be used for the filter are appropriately determined according to the size of the filter, the substance removed by the filter, the pressure loss, etc. For example, the cross-sectional area of ​​the metal wire used in the filter of the inflator is about 0.007 mm 2 Up to 3.2mm 2 (When a metal element wire having a perfect circular cross section is used as a reference, its wire diameter is about 0.1 mm to 2.0 mm).

[0040] A metal wire formed by winding a metal element wire having a perfect circular cross section into a predetermined shape is used for a filter. For example, as the metal wire, a rectangular wire wound into a flat rectangular cross section is used. Alternatively, as the metal wire, a deformed wire wound into a cross section having a substantially W-shaped, U-shaped, J-shaped, L-shaped, X-shaped or other shape across the entire length in the longitudinal direction is used. Alternatively, as the metal wire, a metal wire having a cross-sectional shape and an external shape that are not constant over the entire length in the length direction of the metal wire is used, in other words, a deformed wire wound into a cross-sectional shape and an external shape that are different depending on the position in the length direction of the metal wire. This deformed wire is wound so that, for example, its cross-sectional shape changes at each length in the longitudinal direction equal to the width of the metal wire.

[0041] In the filter 10 , the metal wires 20 are wound without being twisted.

[0042] The filter 10 has a plurality of contact portions where the metal wire material portions are in contact with each other. A heat treatment (e.g., a heat treatment for sintering) that can simultaneously join all contact portions (or a plurality of contact portions) can be applied to the filter 10. Alternatively, in the contact portions of the filter 10, portions other than the end portions on the winding end side can be non-joined portions that are not joined. When a heat treatment for sintering the entire filter 10 is not applied, the manufacturing cost of the filter 10 can be reduced, and the manufacturing time of the filter 10 can be shortened.

[0043] [State of the terminal end]

[0044] The filter 10 according to the present embodiment is characterized in that the winding end portion (terminal portion 30 ) of the metal wire is welded at the portion where the wire is welded. That is, welding and welding are simultaneously applied to the terminal portion 30 in the filter 10 .

[0045] In this example, fusion cutting (or thermal cutting) is to cut the metal wire by heating all or part (inner diameter side) of the metal wire in the thickness direction to the melting point or higher using tension applied to the metal wire. When the entire metal wire in the thickness direction is melted, the molten portion is cut off. When a part of the metal wire in the thickness direction is melted, the molten portion is cut off, and the heat-affected portion (mainly the outer diameter side) adjacent to the molten portion and whose strength is reduced due to the change in texture caused by heating is cut off (peeled off). This example differs from the cutting method using shear force or metal fatigue in that a force is applied to the metal wire in the longitudinal direction of the metal wire to cut the metal wire.

[0046] Figure 2 is a schematic diagram showing the state of the end portion of the filter, wherein Figure 2 (a) is a cross-sectional view of the end portion of the metal wire taken along the length direction, and Figure 2 (b) is a perspective view of the filter viewed from the outer diameter side.

[0047] Hereinafter, a portion of the metal wire portion 20n in contact with the welding electrode is referred to as a “terminal portion 30.” More specifically, the terminal portion 30 is a portion closer to the terminal edge 35 side (cut end side) than the recess 33 formed by the welding electrode.

[0048] The terminal end portion 30 of the metal wire 20 is resistance spot welded to an appropriate portion (joining target portion 21) of another portion (metal wire portion 20m) of the metal wire 20. Figure 2 In FIG. 1 , only the periphery of the terminal portion 30 of the metal wire portion 20n constituting the wire layer Ln as the outermost layer and the metal wire portion 20m belonging to the wire layer Lm located on the inner diameter side of the terminal portion 30 are particularly shown (assuming that m is a natural number and m<n). Figure 2The metal wire portion 20 p indicated by the dotted line on the middle right side is a portion separated from the metal wire portion 20 n by melting and cutting the metal wire 20 . Figure 2 The molten portion 32p indicated by the dotted line is a portion where the metal wire portion 20p is separated from the metal wire portion 20n after being melted.

[0049] On the terminal portion 30 which is a part of the metal wire portion 20n and the metal wire portion 20m which overlaps the terminal portion 30, a melt-solidified portion 31 (31n, 31m) which is melted and solidified during welding is formed. In the melt-solidified portion 31, the metal wire portions 20n and 20m are integrated with each other; however, for convenience, the melt-solidified portion 31 located on the side of each metal wire portion 20n and 20m is described separately as the melt-solidified portions 31n and 31m.

[0050] The melt-solidified portion 31 and the melted portion 32 p are melted portions 32 that are melted just before the metal wire portion 20 p is separated.

[0051] Hereinafter, traces left on a winding or a filter due to melt cutting of a metal wire at a welding portion or a heat-affected portion by the method according to the present invention will be described in detail.

[0052] <Melted and Solidified Section at the Terminal Part>

[0053] The molten solidified portion 31n is a portion where at least a portion of the metal wire portion 20n in the width direction is melted and solidified. The molten solidified portion 31n is preferably formed only in the region in the width direction of the metal wire 20. That is, preferably, the molten solidified portion 31n does not leak to the outside of the end edge of the metal wire portion 20n in the width direction (does not leak to the side).

[0054] The terminal portion 30 shown in the figure has a melt-solidified portion 31n, where the entire width direction of the metal wire portion 20n (the entire width or the entire length in the width direction) is solidified after melting. This means that the entire width direction of the metal wire 20 is covered by the welding electrode during welding, and the entire width direction of the metal wire 20 is melted accordingly. The melt-solidified portion 31n is formed from the terminal edge 35 across a predetermined length of the metal wire in the longitudinal direction. By melting the entire metal wire 20 in the width direction, the metal wire 20 can be reliably melt-cut. In addition, since the entire width direction of the terminal portion 30 is melted and joined to the metal wire portion 20m, it is possible to easily ensure the required joining strength.

[0055] Since the molten solidified portion 31 solidifies after melting, the molten solidified portion is softer than other parts of the metal wire (except high carbon steel). If the metal wire 20 is cut by using shearing force using pliers or scissors, the vicinity of the cut end of the metal wire is work-hardened. However, in the present embodiment, the metal wire is stripped after melting or softening, so that the end portion 30 is not work-hardened. That is, even if heat treatment is not applied to the winding, the molten solidified portion 31 can be prevented from contacting and damaging other components. Unlike the case of cutting the metal wire with pliers, scissors, etc., it is possible to prevent the cut end from rising in a direction intersecting with the length direction of the metal wire as much as possible.

[0056] Since the terminal portion 30 is joined by resistance spot welding, a trace (recess 33) of the electrode pressure applied during welding remains at a portion closer to the start end of the metal wire 20 (closer to the start of winding) than the molten solidified portion 31. The recess 33 is formed over the entire metal wire portion 20n in the width direction.

[0057] The recess 33 has a shape corresponding to the contact form of the electrode when the metal wire 20 is pressed. For example, the recess 33 has a shape in which a portion not pressed by the electrode and a portion pressed by the electrode are continuous via a gradual step. As another example, Figure 2 (b) shows an example in which no step is formed between a portion not pressurized by the electrode and a portion pressurized by the electrode, and the recessed portion 33 is identified as a change point of the inclination angle (or thickness) between the surfaces on the outer diameter side of these portions.

[0058] <Thinning of the terminal end>

[0059] In general, the thickness of the terminal portion 30 is smaller than the thickness t of another portion of the metal wire 20. This means that the metal wire has been melt-cut and the terminal edge 35 has been formed at an appropriate portion of the molten portion 32. This feature does not appear when the metal wire is cut with a pair of shears or the like, that is, when the welded portion and the cut end are separated from each other in the longitudinal direction of the metal wire.

[0060] In the formation area of ​​the molten solidified portion 31n, the terminal portion 30 has a portion (a gradually thinning portion) where the thickness of the metal wire 20 decreases toward the terminal edge 35 of the metal wire 20. Specifically, a portion of the molten solidified portion 31n exposed to the outside gradually becomes thinner toward the terminal edge 35. This means that the terminal portion 30 is melted or softened, stretched toward the terminal edge 35 side, and a part of the thick portion on the outer diameter side of the metal wire 20 located near the terminal portion 30 does not remain on the winding side, but is melted and cut away and disappears (the metal wire portion 20p is separated from the metal wire portion 20n).

[0061] Specifically, Figure 2(b) shows an example in which the thickness of the terminal portion 30 as a whole is uniform and gradually decreases toward the terminal edge 35 .

[0062] Here, there is a case where the molten portion of the metal wire material portion 20n (a portion that becomes the molten solidified portion 31n later) gathers due to the surface tension of the molten metal material and is deformed into a rounded shape such as a sphere to form a solidified terminal edge 35. For example, the thickness of the downstream side portion of the terminal portion 30 gradually decreases toward the terminal edge; however, there is a case where a portion in which the thickness near the terminal edge (the upstream side portion of the terminal portion) is locally increased occurs. Depending on the conditions during the melting and cutting, the upstream side portion of the terminal portion 30 may have a portion with a thickness greater than that of the downstream side portion.

[0063] <Pull marks>

[0064] A pulling mark 37 indicating that the softened metal wire material portion 20n is pulled toward the end edge 35 of the metal wire material 20 is formed at the end portion 30. Alternatively, the pulling mark 37 indicates that the softened metal material has been cut, as if it has been peeled toward the end edge 35. The softened portion is a portion whose strength is reduced by heating at the time of welding, and is a heat-affected portion.

[0065] When the metal wire 20 is wound, a predetermined tension is applied to the metal wire to form the metal wire into a predetermined winding shape. The pulling mark 37 indicates that the metal wire is melt-cut by the tension applied during winding.

[0066] That is, the pull mark 37 is a mark left on the metal wire portion 20n when the metal wire portion 20n is pulled upstream (the side where the metal wire is supplied) by the tension applied to the metal wire portion 20n, softened and cut along with welding. Since the pull mark 37 is a mark indicating that the metal wire portion has been pulled, the pull mark is visually distinguishable from the rolling mark left on other parts of the metal wire 20.

[0067] <Exposure of Melted Solidified Part>

[0068] At least a portion of the melt-solidified portion 31n formed at the terminal portion 30 is exposed to the outside. Figure 2 In (b), the exposed molten solidified portion 31n is shielded. At least a portion of the metal wire material near the end edge 35 in the molten solidified portion 31n is exposed to the outside. The end edge 35 is the molten solidified portion 31n. Figure 2In (b), in the metal wire portion 20n, the terminal edge 35 is welded to the metal wire portion 20m, and the distance between the portion joined by welding and the terminal edge 35 is zero. The molten solidified portion 31n is exposed from the terminal edge 35 across a predetermined length of the metal wire in the length direction. The molten solidified portion 31n formed in the region of the metal wire portion 20n in the width direction is exposed to the outside. The molten solidified portion 31n exposed to the outside constitutes the surface on the outer diameter side of the terminal portion 30.

[0069] This means that part of the thick portion on the outer diameter side of the metal wire portion 20n has disappeared due to pulling and melting. Specifically, this means that the metal wire portion 20p has been separated from the metal wire portion 20n together with the molten portion 32p (a part of the molten portion that melted when heated). Alternatively, this means that at least a part of the heat-affected portion (unmelted portion) formed on the surface of the metal wire portion 20n near the terminal edge 35 has been peeled off.

[0070] When the molten solidified portion 31 is formed across the entire area of ​​the metal wire portion 20n in the width direction, the terminal portion 30 has a portion where the molten solidified portion 31 is exposed across the entire area of ​​the terminal portion 30 in the width direction. In the molten solidified portion 31, particularly at a portion close to the terminal edge 35, the molten solidified portion 31 is exposed across the entire area in the width direction. This means that the metal wire portion 20p is peeled off along the length direction of the metal wire. The molten solidified portions 31n and 31m have a size that applies a bonding force that can withstand the tension applied to the metal wire portion 20n.

[0071] <Joining Target Part>

[0072] The portion of the metal wire portion 20m joined to the terminal portion 30 is referred to as a "joining target portion 21." Here, the joining target portion 21 is explained based on the concept of including a portion joined to the terminal portion 30 (joining portion) and a portion overlapping with the metal wire portion 20n that becomes the terminal portion 30 and joined to the metal wire portion 20n.

[0073] The joining target portion 21 has a melted and solidified portion 31m where at least a portion of the metal wire portion 20m in the width direction w is melted and solidified. Figure 2 In (b), the exposed melt-solidified portion 31m is indicated by oblique lines.

[0074] In this example, at least a portion of the molten solidified portion 31m is exposed to the outside. That is, at least a portion of the molten solidified portion 31n formed at the terminal portion 30 and at least a portion of the molten solidified portion 31m formed at the joining target portion 21 are both exposed to the outside. The molten solidified portions 31n and 31m exposed to the outside constitute the surface on the outer diameter side of the winding.

[0075] This means that the melted and solidified portion 31m is separated from the metal wire portion 20n and exposed due to a part of the melted portion 32 (melted portion 32p) melted during heating of the metal wire portion 20p.

[0076] [Real photo]

[0077] Figure 3 : is a diagram showing the vicinity of the end portion of the filter in a real photograph. The metal wire material 20 used in this figure has a thickness of 0.2 mm.

[0078] Figure 3 The right side of the arrow A in FIG. 3 shows the exposed portion of the melt-solidified portion 31. Figure 3 As shown, it should be understood that Figure 2 The features of the filter shown in (b) are also shown in the actual photograph near the end portion 30 of the filter.

[0079] [Winding manufacturing device]

[0080] Figure 4 1 is a diagram mainly and schematically showing a winding arrangement in a winding manufacturing device.

[0081] Figure 5 1 is a diagram specifically and schematically showing the downstream side of the guide member in the winding manufacturing device. Figure 5 Corresponding to the left side of the figure Figure 4 Schematic diagram of the manufacturing device shown in .

[0082] The manufacturing device 100 for windings includes at least a winding device 130 and a welding machine 150 .

[0083] The winding device 130 includes a spindle 131 that rotates in a specific direction at a predetermined speed and a guide member 132 that guides the metal wire 20 outward toward the spindle 131 at a predetermined tension and reciprocates along the axis Ax2 of the spindle 131 at a predetermined speed to guide the metal wire 20.

[0084] The spindle 131 is generally columnar or cylindrical, and is generally made of a metal such as stainless steel, copper alloy, or aluminum alloy.

[0085] The tensioning unit is provided at the upstream side of the winding device 130 , and the tensioning unit applies a predetermined tension to the metal wire 20 .

[0086] The welding machine 150 joins and fixes a proper portion of the winding end side of the metal wire material 20 to a proper portion of the wound metal wire material 20 by resistance spot welding.

[0087] The welding machine 150 includes an electrode (welding electrode) 160 that contacts an object to be welded and applies a welding current I to the object to be welded while applying pressure to the object to be welded, a power source 155 that supplies power to the electrode 160, and a contact electrode 157 that is connected to the power source 155 and receives the welding current I. The welding machine 150 includes a welding head 151 that holds the electrode 160, a first driving unit 153 that drives the welding head 151, and a second driving unit 159 that moves the contact electrode 157 closer to or farther from the object to be welded.

[0088] Here, in Figure 5 , a tangent line TL (of the spindle 131) is defined in the direction of the metal wire 20 extending from the guide member 132 toward the spindle 131, and a virtual line passing through the axis Ax2 and being orthogonal to both the tangent line TL and the axis Ax2 is defined as a normal line NL (of the spindle 131). An X-axis, a Y-axis, and a Z-axis are defined in respective directions along the axis Ax2, the tangent line TL, and the normal line NL.

[0089] In addition, by using the supply direction of the metal wire 20 as a reference, the guide member 132 side is referred to as the “upstream side”, and the spindle 131 side or the side where the spindle 131 has been wound is referred to as the “downstream side”. The welding machine 150 shown in this example presses the electrode 160 in the normal line NL direction of the spindle 131.

[0090] The first driving unit 153 causes the welding head 151 holding the electrode 160 to reciprocate along the axis Ax2 direction (X direction) of the spindle 131, and causes the welding head 151 to reciprocate along the tangent line TL direction (Y direction) of the spindle 131 so that the welding head 151 Figure 5 The first drive unit 153 drives the electrode 160 in the XY direction to move the electrode 160 closer to or farther from the spindle 131 in the Z direction. The first drive unit 153 drives the electrode 160 in the XY direction to move the electrode 160 to a portion where the metal wire portion 20n and the metal wire portion 20m overlap each other. The first drive unit 153 is configured to preferably include a servo motor or a stepper motor as a means for moving at least the electrode 160 in the XY direction. As long as the electrode 160 can be accurately positioned at least in the XY direction by the servo motor or the stepper motor, a cylinder that does not need to have positioning accuracy can be used as a means for reciprocating the electrode 160 in the Z direction.

[0091] The first driving unit 153 drives the welding head 151 in the direction of the normal line NL to pressurize the portion to be welded through the electrode 160. While the welding head 151 holds the electrode 160 in a state where the central axis Ax3 of the electrode 160 and the pressurizing direction P coincide with each other, the welding head 151 can hold the electrode 160 in a state where the central axis Ax3 is inclined relative to the pressurizing direction P as needed.

[0092] The power supply 155 appropriately controls the magnitude, current application time, application cycle, waveform, etc. of the welding current I, and supplies the welding current I to the electrode 160 .

[0093] As the contact electrode 157 and the second driving unit 159, well-known appropriate contact electrodes and driving units are used.

[0094] The shape and the like of the electrode 160 will be described later.

[0095] [Method for manufacturing filter]

[0096] In order to manufacture the filter 10, first, one end (starting end or winding start) of the metal wire 20 is locked on an appropriate part of the spindle 131 constituting the winding device 130. Under a tension of 0.01 [kgf] to 20 [kgf] applied to the metal wire 20, the spindle 131 rotates in a specific direction at a predetermined speed around the axis Ax2, and the guide member 132 for supplying the metal wire 20 reciprocates along the axis Ax2 of the spindle 131 at a predetermined speed. Through this operation, the metal wire 20 is wound on the outer circumference of the spindle 131 in a spiral and multilayer manner at a predetermined pitch while being tilted at a predetermined angle θ relative to the axis Ax2. In addition, the metal wires (parts of the metal wires) constituting the wire layers adjacent to each other cross each other to form a grid. The grids overlap each other in a regular arrangement in the radial direction to achieve the desired filtering accuracy set.

[0097] For example, in the first metal wire layer directly wound on the outer circumference of the spindle 131, when each metal wire 20 is inclined clockwise at a predetermined angle θ relative to the axial direction of the spindle 131, the metal wire 20 constituting the second metal wire layer wound on the outer circumference of the first metal wire layer is inclined counterclockwise at a predetermined angle θ relative to the axial direction of the spindle 131. Subsequently, after the metal wire 20 is wound a predetermined number of times (predetermined number of layers), the rotation of the spindle 131 is stopped, and the other end portion (terminal end portion or winding end side) of the metal wire 20 is joined and fixed to an appropriate portion of the wound metal wire 20 by resistance spot welding.

[0098] The welding machine 150 brings the electrode 160 and the contact electrode 157 into contact with the winding 11. Figure 8 As shown in (a) and other figures, the power source 155 applies a predetermined welding current I in a state where the electrode 160 presses the metal wire portion 20n against the metal wire portion 20m with a predetermined pressing force. The welding current I is set to a current larger than the current for joining the metal wire portions to each other.

[0099] The metal wire portion 20n is welded to the metal wire portion 20m in a state where the tension Tp is continuously applied during winding. The welding current I is set to a current that melts the metal wire portion 20n to the extent that the metal wire portion 20n cannot withstand the tension.

[0100] A portion of the metal wire material located directly below the electrode 160 is cut by the tension applied to the portion. During the period of energization of the electrode 160, the metal wire material portion 20p located on the upstream side of the electrode 160 is separated from the winding 11. At this time, the metal wire material portion 20p is separated from the winding 11, so that the molten solidified portion 31n (refer to Figure 2 ) is held on the winding 11 side. Since the metal wire is cut by using the tension applied to the metal wire, the electrode 160, the spindle 131 and the tension unit are not operated at the time of cutting, and the electrode 160 continuously presses and fixes the welded portion. In addition, since the metal wire is melt-cut by using the tension applied to the metal wire, welding and cutting can be performed at the same time, which simplifies the manufacturing steps.

[0101] After the metal wire is melted, the power supply 155 stops supplying power. The electrode 160 maintains the pressurized state until the molten portion 32 of the metal wire portions 20n and 20m is cooled and solidified again. After the molten portion 32 is cooled and solidified again, the electrode 160 and the contact electrode 157 are removed from the winding 11, and the winding 11 is removed from the spindle 131.

[0102] For the fusion cutting of the metal wire, it is preferable to use the tension continuously applied to the metal wire from the time of winding. However, when the metal wire can be fusion cut, because the welding portion is fixed by the electrode 160, the tension applied to the metal wire located on the upstream side of the electrode 160 can be controlled to be higher during fusion cutting than during winding. When the tension during winding and during fusion cutting is changed, the tension of the metal wire is adjusted in the tension unit located on the upstream side of the guide member 132.

[0103] Although the above embodiment is an example in which the energization is stopped after the metal wire is melted and cut, the metal wire portion 20 p may be separated from the winding 11 while the electrode 160 is pressing the metal wire after the energization is stopped.

[0104] The angle (winding angle) of the metal wire 20 relative to the spindle 131 in the axial direction and the distance (pitch) between the metal wires 20 adjacent to each other in the axial direction can be changed by appropriately adjusting the ratio between the rotation speed of the spindle 131 and the moving speed of the guide member 132. By appropriately changing the thickness, winding angle, pitch, and winding number of the metal wire, the pressure loss of the fluid passing through the filter can be controlled to an appropriate value.

[0105] The inner diameter of the filter 10 is made to correspond to the outer diameter of the spindle 131 , and the outer diameter of the filter 10 is appropriately adjusted according to the thickness and the winding number of the metal wire material 20 .

[0106] The winding manufactured by the above method is directly used as a filter without performing a sintering process on the entire winding.

[0107] Alternatively, if necessary, after the winding is removed from the spindle 131 , adjacent metal wire portions that have been in contact with each other may be metallurgically bonded by performing a heat treatment such as sintering on the winding body, and then the winding may be used as a filter.

[0108] [Electrode shape]

[0109] Figure 6 is a perspective view showing an example of an electrode.

[0110] Figure 7 (a) and Figure 7 (b) is a plan view for explaining the relationship between the electrode tip end surface and the metal wire material contacting the electrode tip end surface.

[0111] The electrode 160 has an electrode tip end surface 161 that can come into contact with the metal wire during welding.

[0112] The electrode tip end face 161 has a shape and size that can cover the entire metal wire in the width direction across a predetermined length in the length direction of the metal wire. That is, the electrode tip end face 161 has a first length Le1 (length W) that can cover the entire metal wire in the width direction during welding and a second length Le2 that covers a predetermined length of the metal wire in the longitudinal direction, and the second length is longer than the first length.

[0113] However, the length Le1 of the electrode tip end surface 161 is set to a length that does not contact other metal wire parts that are not welded objects. The "other metal wire parts that are not welded objects" mentioned here are metal wire parts that extend in the same direction as the metal wire part 20n (terminal part 30) that contacts the electrode tip end surface 161, and are parts that constitute the surface on the outer diameter side of the winding 11 (exposed to the outer diameter side) and are adjacent to the terminal part 30 in the axial direction of the winding 11, and this expression does not necessarily mean the metal wire part belonging to the wire layer Ln (see Figure 1 ).

[0114] The length Le1 of the electrode tip end surface 161 is set to allow the entire width of the metal wire 20 to be melted so as to reliably cut the length of the metal wire. Therefore, the length Le1 is set to be longer than the length W of the metal wire 20 in the width direction.

[0115] The length Le2 of the electrode tip end surface 161 is set to a length that can form a molten portion that can melt and cut the metal wire portion located upstream of the electrode 160, and after the metal wire portion on the upstream side is separated, a molten portion required to fix the terminal portion of the metal wire 20 to the winding side can be left. Since the entire width direction of the metal wire portion 20n can be melted and joined to the metal wire portion 20m, the necessary joining strength can be ensured.

[0116] Although the electrode 160 shown in the figure is a rectangular parallelepiped having an electrode tip end face 161 that is substantially rectangular, the shape of each portion of the electrode 160 is not limited thereto. In addition, although the electrode having an electrode tip end face 161 that is orthogonal to the central axis Ax3 is shown in the drawings, the central axis Ax3 and the electrode tip end face 161 may not be orthogonal to each other (for example: Fig. 9 (b)).

[0117] The metal wire 20 may take any posture (angle) in the electrode tip end surface 161 as long as the electrode 160 can separate a portion of the metal wire 20 located on the upstream side of the electrode 160 and can fix the remaining metal wire 20 to the winding.

[0118] For example, when the electrode tip end surface 161 is rectangular, Figure 7 As shown in (a), the metal wire 20 can be brought into contact with the electrode tip end surface 161 so that the longitudinal direction of the metal wire 20 coincides with the longitudinal direction (length Le1 direction) of the electrode tip end surface 161 .

[0119] Alternatively, if Figure 7 As shown in (b), the metal wire 20 may be inclined and contact the electrode tip end face 161 so that the longitudinal direction of the metal wire 20 does not coincide with the longitudinal direction (length Le1 direction) of the electrode tip end face 161. This is also true when the electrode tip end face is not rectangular.

[0120] As described above, the electrode 160 may pressurize the metal wire 20 in a state where the longitudinal direction of the metal wire 20 is substantially along the longitudinal direction of the electrode tip end surface 161 .

[0121] [Electrode pressurization of metal wire]

[0122] Figures 8 to 10 1 and 2 are schematic diagrams showing the state of a metal wire before being cut. These drawings each show a state in which a metal wire as an object to be welded is pressed by electrodes and a molten portion is formed by energizing the electrodes.

[0123] <Pressure of the electrode on the metal wire 1>

[0124] exist Figure 8 (a) and Figure 8 The electrode 160 shown in (b) corresponds to Figure 6 and is an electrode having an electrode tip end face 161 that is orthogonal to the central axis Ax3.

[0125] Figure 8 (a) shows a state where the central axis Ax3 of the electrode 160 and the normal line NL are aligned with each other, and the electrode 160 presses the metal wire portions in the pressurizing direction P along the central axis Ax3 to weld both the metal wire portions 20n and 20m.

[0126] The molten zone 32 is uniformly formed on the upstream side ( Figure 8 (a) on the right side) and downstream side ( Figure 8 (left side in (a)).

[0127] although Figure 8 The molten portion 32 shown in (a) does not reach the outer diameter side surface of the metal wire portion 20n, but according to the melting conditions including the magnitude of the melting current I, the metal wire portion 20n melts on the outer diameter side surface, and the molten portion 32 contacts the electrode tip end surface 161. Similarly, the metal wire portion 20n may also melt on the outer diameter side surface. Figure 8 (b) to Fig.10 The surface on the outer diameter side.

[0128] The metal wire 20 is melt-cut at the upstream portion of the molten portion 32 by the tension Tp applied in the longitudinal direction of the metal wire. Subsequently, the metal wire portion 20p located on the upstream side of the electrode 160 is separated from the winding 11. Although the tension Tn=Tp is also applied to the metal wire portion 20n located on the downstream side of the electrode 160, the unwinding force has a component in the Z direction, and the pressure applied in the Z direction by the electrode 160 causes the metal wire 20 to not be melt-cut at the downstream portion of the molten portion 32 (to the left of the normal line NL in the figure), and this portion is finally joined to the winding 11 and becomes the terminal portion 30.

[0129] Since spot welding is performed while applying tension to the metal wire 20 , when the electrode 160 starts applying pressure, tension Tp=Tn is evenly applied to the upstream and downstream sides of the fusion zone 32 .

[0130] Therefore, in an example where the molten portion 32 is formed equally on the upstream and downstream sides of the normal line NL, there is a possibility that the metal wire 20 is melt-cut at the downstream and upstream portions of the molten portion 32. In order to prevent this, Figure 8In (a), it is preferable to operate the tensioning unit so that the tension Tp>Tn is established after the electrode 160 pressurizes the metal wire portions 20n and 20m. Thus, it is possible to prevent the downstream portion of the molten portion 32 and the unmelted portion in the metal wire portion 20n from being peeled off due to the tension Tn applied to the metal wire portion 20n, thereby enabling the metal wire portion 20p to be separated from the winding 11.

[0131] Figure 8 (b) shows a state where the central axis Ax3 of the electrode 160 is located on the downstream side of the normal line NL, and the metal wire portions 20n and 20m are welded by pressing the metal wire portions along the central axis Ax3 in the pressing direction P by the electrode 160. Figure 8 In (b), the normal line NL is located outside the electrode tip end surface 161 , however, the electrode 160 may be placed so that the normal line NL is located within the plane of the electrode tip end surface 161 .

[0132] Since the central axis Ax3 of the electrode 160 is located on the downstream side of the normal line NL, the pressure applied by the electrode 160 to the metal wire portions 20n and 20m is relatively strong in the upstream portion of the electrode 160 and relatively small in the downstream portion of the electrode 160. The pressure changes continuously according to the distance from the normal line NL.

[0133] In the upstream part of the electrode 160, due to the sufficient pressing force, the resistance between the metal wire parts 20n and 20m becomes sufficiently small, and the welding current I flows efficiently. In the downstream part of the electrode 160, since the pressing force is smaller than the pressing force at the upstream part, the resistance increases. Therefore, the welding current I flowing between the metal wire parts 20n and 20m is smaller than the welding current I at the upstream part. The molten portion 32 formed between the metal wire parts 20n and 20m is relatively large on the upstream side and relatively small on the downstream side. Therefore, the metal wire part 20p located in the upstream part of the electrode 160 is easily melted, and the metal wire part 20n located in the downstream part of the electrode 160 is prevented from being unnecessarily melted, and the required bonding strength between the metal wire parts 20n and 20m can be ensured.

[0134] Since the metal wire 20 has an oxide coating formed on its surface in most cases, by utilizing the fact that the pressing force becomes relatively strong at the upstream side portion of the electrode 160, the oxide coating of the metal wire at the upstream side portion of the electrode 160 can be destroyed and the resistance at this portion can be effectively reduced.

[0135] According to the distance between the center axis Ax3 and the normal line NL, and the pressing force applied by the electrode 160 to the metal wire 20, the welding current I can be prevented from flowing on the downstream side of the electrode tip end face 161. In this case, the portion of the electrode tip end face 161 that is not energized functions as a pressing and cooling mechanism that cools the metal wire portions 20n and 20m while pressing them. On the other hand, the portion of the electrode tip end face 161 that is energized functions as a pressing and energizing unit that energizes the metal wire portions 20n and 20m while pressurizing them. The pressing and cooling unit presses the metal wire portions 20n and 20m and holds them to prevent the metal wire portion 20n from being separated from the metal wire portion 20m due to the tension Tn applied to the metal wire portion 20n.

[0136] <Pressure of metal wire by electrodes 2>

[0137] Fig. 9 (a) and Fig. 9 (b) shows an example in which the metal wire portions 20n and 20m are pressurized in a state in which the electrode tip end surface 161 is inclined with respect to the tangent line TL.

[0138] Fig. 9 (a) shows the use of Figure 6 An example of an electrode 160 having an electrode tip end surface 161 that is orthogonal to the central axis Ax3 is shown in FIG.

[0139] In this example, the pressing direction P coincides with the direction of the normal line NL, and the intersection between the electrode tip end surface 161 and the center axis Ax3 is on the normal line NL. However, the center axis Ax3 of the electrode 160 is inclined at an angle Φ to the upstream side relative to the normal line NL, so the pressing force applied by the electrode 160 to the metal wire portions 20n and 20m becomes stronger in the upstream portion of the electrode 160 and becomes smaller in the downstream portion.

[0140] Therefore, due to Figure 8 (b) For the same reason, the molten portion 32 formed between the metal wire portions 20n and 20m becomes larger on the upstream side and smaller on the downstream side. Figure 8 The effect is the same as in (b).

[0141] The pressurizing direction P can be made consistent with the direction of the central axis Ax3.

[0142] Fig. 9(b) shows an example of using an electrode 160 having an electrode tip end surface 161 that is not orthogonal to the central axis Ax3. In this electrode 160, an axis Ax4 orthogonal to the electrode tip end surface 161 is inclined at an angle λ toward the upstream side relative to the central axis Ax3.

[0143] In this example, the pressing direction P coincides with the direction of the normal line NL, and the intersection between the electrode tip end surface 161 and the central axis Ax3 is on the normal line NL. However, since the upstream side portion of the electrode tip end surface 161 protrudes toward the tip direction of the electrode 160, the pressing force applied by the electrode 160 to the metal wire becomes stronger in the upstream portion of the electrode 160 and becomes smaller in the downstream portion.

[0144] Therefore, due to Figure 8 For the same reason as (b) of FIG. 1 , the molten portion 32 formed between the metal wire portions 20n and 20m becomes larger on the upstream side and smaller on the downstream side. Figure 8 The effect is the same as in (b).

[0145] The pressurizing direction P can be made consistent with the direction of the axis Ax4.

[0146] <Pressure of metal wire by electrodes 3>

[0147] Fig.10 (a) and Fig.10 The electrode 160 shown in (b) includes: a pressurizing and energizing unit 163 that applies electricity to the metal wire portions 20n and 20m while pressurizing the metal wire portions 20n and 20m abutting against the upstream side portion; and a pressing and cooling unit 165 that cools the metal wire portions 20n and 20m while pressing them at the downstream side portion.

[0148] Fig.10 The entirety of the electrode 160 shown in (a) is formed integrally with a conductor. The pressurizing and energizing unit 163 protrudes further toward the tip direction of the electrode 160 than the pressing and cooling unit 165. In addition, a step 164 is formed between the pressurizing and energizing unit 163 and the pressing and cooling unit 165. The electrode tip end surface 161 on the pressurizing and energizing unit 163 side and the electrode tip end surface 161 on the pressing and cooling unit 165 side are respectively roughly rectangular, and are both planes orthogonal to the central axis Ax3.

[0149] Fig.10 (a) shows a state where the center axis Ax3 and the normal line NL are aligned with each other, and the metal wire portions 20n and 20m are welded by applying pressure to the metal wire portions in the pressure direction P along the center axis Ax3 by the electrode 160.

[0150] Since the pressurizing and energizing unit 163 protrudes toward the front end direction of the electrode 160, even if the central axis Ax3 of the electrode 160 and the normal line NL are aligned with each other in position, the force of the pressurizing and energizing unit 163 on the metal wire portion can be made stronger than the force of the pressurizing and cooling unit 165 on the metal wire portion. Since there is a step between the pressurizing and energizing unit 163 and the pressurizing and cooling unit 165, the pressurizing force of the pressurizing and energizing unit 163 on the metal wire portion and the pressurizing force of the pressurizing and cooling unit 165 on the metal wire portion can be different stepwise (non-continuously). The central axis Ax5 of the pressurizing and energizing unit 163 is located on the upstream side relative to the normal line NL.

[0151] Therefore, in the pressurizing and energizing unit 163, sufficient pressurizing force makes the resistance between the metal wire parts 20n and 20m sufficiently small, and the welding current I flows efficiently. At the pressing and cooling unit 165, the pressing force becomes significantly smaller than the pressurizing and energizing unit 163, so that the resistance increases and the welding current I can be prevented from flowing.

[0152] The electrode 160 forms the molten portion 32 only between the metal wire portions 20n and 20m on the side of the pressurizing and energizing unit 163. The pressing and cooling unit 165 cools the metal wire portions 20n and 20m while pressing them. The pressing and cooling unit 165 presses the metal wire portions 20n and 20m and holds them to prevent the metal wire portion 20n from being separated from the metal wire portion 20m by the tension Tn applied to the metal wire portion 20n. Therefore, only a portion of the metal wire 20 located on the upstream side of the electrode 160 can be melted.

[0153] Since the metal wire 20 has an oxide coating formed on the surface thereof in most cases, the oxide coating of the metal wire may be broken at the pressurizing and energizing unit 163 which is a side having a strong pressure, and the resistance at the portion may be effectively reduced.

[0154] Fig.10 The electrode 160 shown in (b) includes a heat insulating member 167, which is placed between the pressurizing and energizing unit 163 and the pressing and cooling unit 165. The tip end surface of the electrode 160 is a plane orthogonal to the central axis as a whole. The tip end surface on the pressurizing and energizing unit 163 side is a conductive electrode tip end surface 161, and the tip end surface on the pressing and cooling unit 165 side is a non-conductive pressurizing surface 169.

[0155] The pressurizing and energizing unit 163 and the pressing and cooling unit 165 may be made of the same material. The pressing and cooling unit 165 is preferably made of a material having high thermal conductivity. By making the pressing and cooling unit 165 itself an insulator, the heat insulating member 167 can be omitted.

[0156] Fig.10 (b) shows a state where both the metal wire portions 20n and 20m are welded by pressing the metal wire portions in the pressing direction P along the center axis Ax3 by the electrode 160 in a state where the center axis Ax3 and the normal line NL are aligned in position with each other.

[0157] The molten portion 32 is formed only between the metal wire portions 20 n and 20 m on the pressurizing and energizing unit 163 side.

[0158] The function of the compression and cooling unit 165 is Fig.10 The electrodes shown in (a) function identically.

[0159] In this example, only a portion of the metal wire portion 20 n located at the upstream side portion of the electrode 160 may be melt-cut.

[0160] and Fig.10 Similar to (a), the pressurizing and energizing unit 163 may be made to protrude more toward the tip side than the pressing and cooling unit 165 .

[0161] [Effect]

[0162] The filter 10 according to the present embodiment is fusion-cut at the portion where the terminal portion 30 has been welded. That is, when the filter 10 is manufactured, welding and fusion-cutting of the terminal portion 30 are performed simultaneously.

[0163] Therefore, the present embodiment can provide a winding in which the distance from the welded portion to the terminal edge is made as short as possible without increasing the number of manufacturing steps. By making the distance from the welded portion to the terminal edge as short as possible, in particular by setting the distance to zero, a winding that does not damage other components or the like due to the terminal portion of the metal wire can be manufactured, and a defective winding in which the welded portion has been peeled off can be prevented from being produced.

[0164] [Overview of the functions and effects of various aspects of the present invention]

[0165] <Winding>

[0166] <<First Aspect>>

[0167] The present invention relates to a porous winding (filter 10) formed by spirally and multi-layering at least one continuous metal wire 20. When winding, the terminal portion 30 (metal wire portion 20n) of the metal wire is resistance spot welded to the other portion (metal wire portion 20m) of the metal wire, and melt-cut at the welded portion. Here, the terminal portion is defined as a portion closer to the terminal edge 35 than the concave portion 33 formed by welding the electrode.

[0168] According to the present aspect, there is provided a winding in which the distance from the welding portion to the terminal edge is made as short as possible without increasing the number of manufacturing steps. It is also possible to use the terminal edge as the welding portion.

[0169] Such a winding has the external shape characteristics described as traces associated with the cutting of the metal wire in the third to eleventh aspects.

[0170] <<Second Aspect>>

[0171] The present invention relates to a porous winding (filter 10) formed by winding at least one continuous metal wire 20 in a spiral and multi-layer manner. When winding, the terminal portion 30 (metal wire portion 20n) of the metal wire is resistance spot welded to the other portion (metal wire portion 20m) of the metal wire and melt-cut at the welded portion, and the heat-affected portion near the welded portion is peeled off. Here, the terminal portion is defined as a portion closer to the terminal edge 35 than the recessed portion 33 formed by welding the electrode.

[0172] According to the present aspect, there is provided a winding in which the distance from the welding portion to the terminal edge is made as short as possible without increasing the number of manufacturing steps. It is also possible to use the terminal edge as the welding portion.

[0173] Such a winding has the external shape characteristics described as traces associated with the cutting of the metal wire in the third to eleventh aspects.

[0174] <<Third Aspect>>

[0175] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) has a melt-solidified portion 31n in which the entirety of the metal wire in the width direction is melted and solidified.

[0176] Specifically, the melt-solidified portion is formed from the distal end edge of the metal wire material over a predetermined length in the longitudinal direction.

[0177] According to this aspect, since the entire width direction of the metal wire is melted, the metal wire can be reliably melt-cut at this portion. In addition, since the entire width direction of the terminal portion is melted and joined to another portion of the metal wire, the necessary joining strength can be ensured.

[0178] <<Fourth Aspect>>

[0179] The winding (filter 10 ) according to the present aspect is characterized in that, at the terminal portion 30 (metal wire portion 20 n ), the thickness of the metal wire gradually decreases toward the end edge 35 of the metal wire.

[0180] The outer shape characteristics of the winding according to the present invention described above show that due to the melting, a part of the thick portion on the outer diameter side of the metal wire material located near the terminal portion does not remain on the winding side. In addition, when the terminal portion is pulled toward the terminal edge due to melting or softening, the outer shape characteristics also appear.

[0181] The metal wire cannot be cut with pliers, scissors, etc. at the welding portion, so that the characteristics according to the present aspect do not appear in the cutting method using the shearing force of pliers, scissors, etc. That is, unless the metal wire is cut at the resistance spot welding portion, the entire concavity will mostly remain on the metal wire, so that when the metal wire is cut with pliers, scissors, etc., the thickness does not gradually decrease toward the terminal portion.

[0182] <<Fifth Aspect>>

[0183] The winding (filter 10 ) according to the present aspect is characterized in that a pulling mark 37 is formed at the terminal portion 30 (metal wire portion 20 n ), indicating that the softened metal wire is pulled toward the terminal edge 35 .

[0184] In order to form the metal wire into a predetermined winding shape, a predetermined tension is applied to the metal wire when the metal wire is wound. The pulling mark indicates that the metal wire has been melt-cut by using the tension applied when winding.

[0185] <<Sixth Aspect>>

[0186] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) has a molten solidified portion 31n, in which at least a portion of the metal wire in the width direction is solidified after melting, and at least a portion of the molten solidified portion is exposed to the outside.

[0187] Generally, the molten solidified portion appearing outside during spot welding indicates welding failure, so when spot welding is performed, the molten solidified portion is generally not exposed to the outside. However, in the present aspect, since the metal wire is melt-cut, at least a portion of the molten solidified portion is exposed to the outside.

[0188] <<Seventh Aspect>>

[0189] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) has a molten solidified portion 31n, in which at least a portion of the metal wire in the width direction is solidified after melting, and the terminal edge 35 of the metal wire is the molten solidified portion, and the molten solidified portion is exposed to the outside at a predetermined length from the terminal edge along the longitudinal direction of the metal wire.

[0190] In this aspect, since the metal wire is melt-cut, the molten solidified portion is exposed to the outside. Since a part of the molten molten portion is separated from the winding during heating, the molten solidified portion is exposed to the outside over a predetermined length in the longitudinal direction from the terminal edge.

[0191] <<Eighth Aspect>>

[0192] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) has a molten solidified portion 31n, in which at least a portion of the metal wire in the width direction is solidified after melting, at least a portion of the molten solidified portion is exposed to the outside, and the portion exposed to the outside in the molten solidified portion has a portion whose thickness gradually decreases toward the terminal edge 35 of the metal wire.

[0193] According to the outer shape characteristics of the winding of the present invention described above, the terminal portion is pulled toward the terminal edge, and a portion of the thick portion on the outer diameter side of the metal wire near the terminal portion does not remain on the winding side due to melting.

[0194] This characteristic does not occur when a metal wire is cut with scissors, pliers, etc. by using shearing force.

[0195] <<Ninth Aspect>>

[0196] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) and the other portion of the metal wire (metal wire portion 20m) respectively have a molten solidified portion 31 (31n, 31m) that solidifies after melting, and at least a portion of the molten solidified portion 31m formed on the other portion of the metal wire is exposed to the outside.

[0197] The above-mentioned characteristics of the winding according to the present aspect indicate that the metal wire portion 20p on the upstream side is separated from the metal wire portion 20n together with a part of the molten portion (molten portion 32p) melted during heating.

[0198] <<Tenth Aspect>>

[0199] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 (metal wire portion 20n) and other portions of the metal wire (metal wire portion 20m) respectively have molten solidified portions 31 (31n, 31m) that solidify after melting, and at least a portion of the molten solidified portion 31n formed at the terminal portion and at least a portion of the molten solidified portion 31m formed at other portions of the metal wire are exposed to the outside.

[0200] The above characteristics of the winding of this aspect indicate that the upstream metal wire portion 20p is separated from the metal wire portion 20n together with a part of the molten portion (molten portion 32p) melted during heating. In this aspect, since the metal wire is melted and cut, the molten solidified portion 31n is exposed to the outside.

[0201] <<Aspect 11>>

[0202] The winding (filter 10) according to the present aspect is characterized in that the terminal portion 30 has a melted solidified portion 31n where the metal wire 20 is melted and solidified, and the melted solidified portion formed within the width of the metal wire portion 20n constituting the terminal portion is exposed to the outside.

[0203] The molten solidified portion exposed to the outside constitutes the surface on the outer diameter side of the winding. The outer shape characteristics of the winding according to the present invention indicate that the portion near the end portion of the thick portion located on the outer diameter side of the metal wire is not retained on the winding side due to melting. At least the molten solidified portion constituting the surface on the outer diameter side of the winding does not leak sideways.

[0204] <Method for Manufacturing Winding>

[0205] <<Twelfth Aspect>>

[0206] The present invention relates to a method for manufacturing a porous winding (filter 10) formed by winding at least one continuous metal wire 20 in a spiral and multi-layer manner.

[0207] According to the present aspect, the method includes: a winding step in which a metal wire is wound around a spindle 131 in a spiral and multi-layer manner while applying a predetermined tension to the metal wire; and a welding step in which a wound end portion of the metal wire (metal wire portion 20n, terminal portion 30) is welded to the wound metal wire portion 20m by resistance spot welding.

[0208] The welding step is characterized in that the metal wire portion on the supply side is melt-cut from the wound metal wire portion by utilizing the tension continuously applied to the above-mentioned metal wire.

[0209] In this aspect, since the metal wire is melted and cut by utilizing the tension applied to the metal wire, welding and cutting can be performed simultaneously, and the production steps of winding can be simplified.

[0210] The tension applied to the metal wire during the fusion cutting may be the same as or different from the tension applied to the metal wire during the winding step.

[0211] According to the present aspect, it is possible to provide a winding in which the distance from the welded portion to the terminal edge is made as short as possible without increasing the number of manufacturing steps.

[0212] <<Thirteenth Aspect>>

[0213] The manufacturing method according to the present aspect is characterized in that, when the side where the metal wire 20 is supplied to the spindle 131 is set as the upstream side and the side where the metal wire has been wound around the spindle is set as the downstream side, in the welding step, the welding electrode 160 is brought into contact with the metal wire portion 20n so that the pressing force applied to the metal wire portion 20n on the upstream side of the welding electrode 160 is stronger than the pressing force applied to the metal wire portion on the downstream side of the welding electrode ( Figure 8 (b) to Fig.10 ).

[0214] According to this aspect, the molten portion becomes larger in the upstream portion where the pressure is strong, and becomes smaller in the downstream portion where the pressure is small. Therefore, the metal wire portion in the upstream portion is easily melted and cut. In addition, the metal wire portion located in the downstream portion can be prevented from being unnecessarily melted and cut.

[0215] <<Fourteenth Aspect>>

[0216] The manufacturing method according to the present aspect is characterized in that, when the extending direction of the metal wire 20 supplied to the spindle 131 is defined as the tangent line TL direction, and a virtual line passing through the axis Ax2 of the spindle and being orthogonal to both the tangent line and the axis is defined as the normal line NL of the spindle, in the welding step, the welding electrode 160 is placed in such a manner that the central axis Ax3 of the welding electrode 160 is located on the downstream side with respect to the normal line, and in a state where the normal line direction and the central axis line are made to coincide with each other, the metal wire (metal wire portion 20n) is pressed in the normal line direction by the welding electrode, and the wound end portion of the metal wire is welded to the wound metal wire portion 20m ( Figure 8 (b)).

[0217] According to this aspect, since the central axis of the welding electrode is located downstream relative to the normal line, the pressure applied to the upstream portion of the welding electrode can be made stronger than the pressure applied to the downstream portion of the welding electrode.

[0218] <<Fifteenth Aspect>>

[0219] The manufacturing method according to the present aspect is characterized in that when the extending direction of the metal wire 20 supplied to the spindle 131 is defined as the direction of the tangent TL, and a virtual line passing through the axis Ax2 of the spindle and being orthogonal to both the tangent and the axis is defined as the normal line NL of the spindle, in the welding step, in a state where the normal line (axis lines Ax3 and Ax4) of the electrode tip end surface 161 of the welding electrode 160 is inclined toward the side of the supplied metal wire and exceeds the normal line NL of the spindle, the metal wire is pressurized by the welding electrode, and the wound end portion of the metal wire is welded to the wound metal wire portion 20m.

[0220] In this aspect, by inclining the normal line of the electrode tip end surface, the pressing force of the upstream portion of the welding electrode is made stronger than the pressing force of the downstream portion of the welding electrode. This aspect also has the same effects as the eleventh aspect.

[0221] <Welding Electrode>

[0222] <<Sixteenth Aspect>>

[0223] The welding electrode 160 according to the present aspect is a welding electrode used when manufacturing a porous winding (filter 10) formed by winding at least one continuous metal wire 20 around a rotating spindle 131 to form a metal wire wound in a spiral and multi-layer manner.

[0224] The welding electrode 160 is characterized by including an electrode tip end surface 161, which has a first length Le1 ( Figures 6 to 10 ).

[0225] According to this aspect, since the entirety of the metal wire in the width direction can be melted, the fusion cutting can be reliably performed. This aspect can provide a winding in which the distance from the welded portion to the terminal edge is as short as possible without increasing the number of manufacturing steps. According to this aspect, for example, the terminal portion 30 of the metal wire can be joined to another portion of the metal wire (metal wire portion 20m) by melting the entirety of the terminal portion 30 of the metal wire in the width direction, so that the necessary joining strength can be ensured.

[0226] <<Seventeenth Aspect>>

[0227] The welding electrode 160 according to the present aspect is characterized in that the electrode tip end face 161 has a second length Le2 that can cover a predetermined length in the longitudinal direction of the metal wire 20, and the electrode tip end face 161 includes a pressurizing and energizing portion 163 on one side in the second length direction, and the pressurizing and energizing portion 163 energizes the two metal wire portions 20n and 20m while pressurizing the metal wire portions, so that they become welding objects overlapping each other; and includes a pressing and cooling unit 135 on the other side in the second length direction, and the pressing and cooling unit 135 cools a metal wire portion (20n) in contact with the electrode tip end face while pressing the metal wire portion. Fig.10 , Fig. 9 (b)).

[0228] According to the present aspect, when the metal wire material is melt-cut at the pressurizing and energizing unit, the metal wire material can be prevented from being melt-cut at the pressing and cooling unit.

[0229] <<Aspect 18>>

[0230] The welding electrode 160 according to the present aspect is characterized in that the pressurizing and energizing unit 163 protrudes toward the tip of the welding electrode more than the pressing and cooling unit 165 ( Fig.10 (a) Fig. 9 (b)).

[0231] According to this aspect, by making the pressurizing and energizing unit protrude toward the tip of the welding electrode more than the pressing and cooling unit, the pressurizing force of the pressurizing and energizing unit on the metal wire portion and the molten portion of the metal wire portion can be increased, and the pressurizing force of the pressurizing and cooling unit on the metal wire portion and the molten portion of the metal wire portion can be reduced. Therefore, the metal wire portion on the pressurizing and energizing unit side is easily melted. In addition, the metal wire portion of the pressing and cooling unit can be prevented from being melted unnecessarily.

[0232] <<Nineteenth Aspect>>

[0233] The welding electrode 160 according to the present aspect is characterized in that the pressing and cooling unit 165 is configured to be non-energized ( Fig.10 (b)).

[0234] According to this aspect, when the metal wire material is welded and melted in the pressurizing and energizing unit, it is possible to prevent the metal wire material from being melted in the press cooling unit.

[0235] <Winding Manufacturing Apparatus>

[0236] <<Aspect 20>>

[0237] The present aspect relates to a manufacturing apparatus 100 for manufacturing a porous winding (filter 10) by winding at least one continuous metal wire 20 in a spiral and multi-layer manner.

[0238] The manufacturing device includes a spindle 131, which rotates at a predetermined speed in a specific direction and around which a metal wire is wound in a spiral and multi-layer manner; and a welding machine 150, which welds the wound end portion of the metal wire (metal wire portion 20n) to the wound metal wire portion 20m by resistance spot welding.

[0239] The welding machine is characterized by comprising the welding electrode 160 (see the drawings) according to any one of the fourteenth to seventeenth aspects.

[0240] This manufacturing apparatus has the effects described in the fourteenth to seventeenth aspects.

[0241] Reference numerals list

[0242] L…wire layer, w…width of metal wire, t…thickness of metal wire, Le1, Le2…length of electrode tip end surface, Tn, Tp…tension, Ax1…central axis of filter, Ax2 axis of spindle, Ax3 central axis of electrode, Ax4 orthogonal axis of electrode tip end surface, Ax5 central axis of pressurizing and energizing unit, 10 filter, 20 metal wire, 20n, 20m…metal wire portion, 20p…(separated) metal wire portion, 21…joining target portion (of metal wire portion 20m), 30…terminal portion, 31, 31n, 31 m…melting solidification portion, 32…melting portion, 32p…(separated) melting portion, 33…recess, 35…end edge, 37…pulling mark, 100…manufacturing device, 130…winding device, 131…spindle, 132…guide member, 150…welding machine, 151…welding head, 153…first driving unit, 155 power supply, 157 contact electrode, 159 second driving unit, 160 electrode (welding electrode), 161 electrode tip end surface, 163 pressurizing and energizing unit, 164 step, 165 pressing and cooling unit, 167 heat insulating member, 169 pressing surface

Claims

1. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein A terminal end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the terminal end portion is melt-cut at a welded portion.

2. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The tip portion of the metal wire is resistance spot welded to another portion of the metal wire, and the tip portion is melt-cut at the welded portion, and a heat-affected portion near the welded portion is peeled off.

3. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion has a melt-solidified portion in which the entirety of the metal wire in the width direction is melted and solidified in a region spanning a predetermined length in the longitudinal direction from the terminal edge of the metal wire.

4. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and At the terminal portion, a thickness of the metal wire gradually decreases toward a terminal edge of the metal wire.

5. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion and at a heat-affected portion near the welded portion, and The terminal portion has a pulling mark indicating that the softened metal wire has been pulled toward the terminal edge.

6. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion has a melt-solidified portion in which at least a portion of the metal wire material in a width direction is solidified after being melted, and at least a portion of the melt-solidified portion is exposed to the outside.

7. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion has a molten solidified portion in which at least a portion of the metal wire in the width direction is solidified after being melted, the terminal edge of the metal wire is the molten solidified portion, and the molten solidified portion is exposed to the outside over a predetermined length from the terminal edge in the longitudinal direction of the metal wire.

8. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion has a melt-solidified portion in which at least a portion of the metal wire in the width direction is solidified after being melted, at least a portion of the melt-solidified portion is exposed to the outside, and the portion exposed to the outside in the melt-solidified portion has a portion whose thickness gradually decreases toward the terminal edge of the metal wire.

9. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion and the other portion of the metal wire material each have a melt-solidified portion that solidifies after being melted, and at least a portion of the melt-solidified portion formed on the other portion of the metal wire material is exposed to the outside.

10. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, and The terminal portion and the other portion of the metal wire respectively have a molten solidified portion that solidifies after melting, and at least a portion of the molten solidified portion formed on the terminal portion and at least a portion of the molten solidified portion formed on the other portion of the metal wire are exposed to the outside.

11. A porous winding formed by winding at least one continuous metal wire in a spiral and multi-layer manner, wherein The end portion of the metal wire is resistance spot welded to another portion of the metal wire, and the end portion is melt-cut at the welded portion or at the welded portion and a heat-affected portion near the welded portion, The terminal portion has a melt-solidified portion in which the metal wire material is solidified after being melted, and The melt-solidified portion formed within the width of the metal wire portion constituting the terminal portion is exposed to the outside.

12. A method for manufacturing a porous winding, the porous winding being formed by winding at least one continuous metal wire in a spiral and multi-layer manner, the method comprising: A winding step of winding the metal wire around a spindle in a spiral and multi-layer manner while applying a predetermined tension to the metal wire; as well as a welding step of welding the wound end of the metal wire to the wound metal wire portion by resistance spot welding; in In the welding step, the metal wire portion on the supply side is melt-cut from the coiled metal wire portion by using the tension continuously applied to the metal wire.

13. The method for producing a winding according to claim 12, wherein When the side where the metal wire is supplied to the spindle is set as the upstream side, and the side where the metal wire has been wound around the spindle is set as the downstream side, In the welding step, a welding electrode is brought into contact with the metal wire portion so that a pressure applied to the metal wire portion at an upstream side of the welding electrode becomes stronger than a pressure applied to the metal wire portion at a downstream side of the welding electrode.

14. The method for producing a winding according to claim 13, wherein: When the extending direction of the metal wire supplied to the spindle is defined as a tangent direction, and a virtual line passing through the axis of the spindle and being orthogonal to both the tangent and the axis is defined as a normal line of the spindle, In the welding step, the welding electrode is placed so that the central axis of the welding electrode is located on the downstream side relative to the normal line, and the metal wire is pressurized in the normal line direction by the welding electrode in a state in which the direction of the normal line and the central axis are made consistent with each other, thereby welding the winding end of the metal wire to the wound metal wire portion.

15. The method for manufacturing a winding according to claim 13, wherein: When the extending direction of the metal wire supplied to the spindle is defined as a tangent direction, and a virtual line passing through the axis of the spindle and being orthogonal to both the tangent and the axis is defined as a normal line of the spindle, In the welding step, the metal wire is pressurized by the welding electrode in a state where the normal line of the electrode tip end surface of the welding electrode is inclined toward a side of the metal wire supplied beyond the normal line of the spindle, and the wound end portion of the metal wire is welded to the wound metal wire portion.

16. A welding electrode for use in manufacturing a porous winding formed by winding at least one continuous metal wire around a rotating spindle, the metal wire being wound in a spiral and multi-layer manner, the welding electrode comprising: The electrode tip end surface has a first length capable of covering the entirety of the metal wire in a width direction during welding.

17. The welding electrode according to claim 16, wherein: The electrode tip end surface has a second length capable of covering a predetermined length in the length direction of the metal wire, and The electrode tip end surface includes a pressurizing and energizing unit on one side of the second length direction, and the pressurizing and energizing unit applies electricity to two metal wire parts overlapping each other as objects to be welded while pressurizing the metal wire parts, and the electrode tip end surface includes a pressing and cooling unit on the other side of the second length direction, and the pressing and cooling unit cools the metal wire part in contact with the electrode tip end surface while pressing the metal wire part.

18. The welding electrode according to claim 17, wherein: The pressurizing and energizing unit protrudes further toward the tip end direction of the welding electrode than the pressing and cooling unit.

19. The welding electrode according to claim 17, wherein: The pressing and cooling unit is configured not to be powered.

20. A manufacturing device for manufacturing a porous winding by spirally and multi-layer winding of at least one continuous metal wire, the manufacturing device comprising: a spindle, the spindle rotating at a predetermined speed in a specific direction, and the metal wire material being wound around the spindle in a spiral and multi-layer manner; as well as A welding machine that welds the coiled end of the metal wire to the coiled metal wire portion by resistance spot welding, wherein The welding machine comprises a welding electrode according to any one of claims 16 to 19.

Images