Method for manufacturing conductive member and method for manufacturing metal member

Abstract

To provide a method for manufacturing a conductive member by bending by which the occurrence of deformation such as uneven thickness is suppressed and the occurrence of end material is prevented.SOLUTION: Bending a metal material in a predetermined bending direction, and compressing the metal material subjected to the bending in a compression direction perpendicular to a surface including a bent portion formed by the bending; Producing a conductive member having a cross-sectional shape in which a cross-sectional ratio b1 / b1 is 1 or more and 65 or less, the cross-sectional ratio h1 / b1 being a ratio of a breadth h1 in a direction of a bend radius of the bent portion of the metallic material to a thickness LA in a direction perpendicular to the breadth LA in a cross section along the direction of the bend radius.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a conductive member and a method for manufacturing a metal member. [Background technology]

[0002] Busbars have traditionally been used as conductive members for carrying current in power converters, motors, secondary battery modules, secondary battery packs, and the like. Unlike conductor wires, busbars are generally strip-shaped (plate-shaped), and many have a rectangular cross section. Compared to conductor wires with a circular cross section, strip-shaped conductive members with a busbar-like cross section can secure a larger cross-sectional area in a limited space and can supply higher voltage and current power. Such strip-shaped conductive members can be fabricated into various shapes by processing metal sheets such as copper. For example, curved conductive members are also used depending on the positional relationship of the points to be connected by the conductive member.

[0003] Conductive components with a curved shape can also be used that are bent in the width direction of a strip of material (the long side direction of a rectangular cross section). Such a curved shape can be formed by in-plane bending (edgewise bending) of strip-shaped metal material. However, when conductive components are produced using in-plane bending, deformations such as buckling, twisting, and thickness irregularities at the bent portion can occur. Such deformations, such as thickness irregularities, are more likely to occur when processing with a smaller bending radius to save space, etc.

[0004] In response to this, for example, Patent Document 1 proposes a copper strip for edgewise bending in which the arithmetic mean height Sa of the end faces of the copper strip used in edgewise bending (the surfaces that will be on the outside of the bent portion after edgewise bending) is set to 10 μm or less, and electrical equipment components and bus bars that use this copper strip. It is claimed that the use of this copper strip suppresses the occurrence of cracks and other problems in the bent portion when edgewise bending is performed, and that bus bars and the like with a uniform shape can be obtained.

[0005] On the other hand, another method for producing conductive components with an in-plane bent shape is to cut the desired shape directly from a sheet material. This cutting method does not involve bending. Examples of cutting methods include punching, laser processing, and wire electrical discharge machining. This cutting method allows for greater freedom in the shapes that can be produced. For example, conductive components with a smaller bending radius as mentioned above can also be produced. Since no bending is performed, uneven thickness does not occur. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-008975 Summary of the Invention [Problem to be solved by the invention]

[0007] Even if a conductive member having an in-plane bent shape is produced using the method described in Patent Document 1, it is unclear whether it can prevent uneven cross-sectional shapes such as thickness deviations when bending with a smaller bending radius. Furthermore, in the case of the cutting method described above, thickness deviations and the like caused by bending do not occur, but scraps are generated after cutting, resulting in low yields. The present application provides a method for manufacturing conductive members and the like using bending, which can suppress deformation such as thickness deviations and prevent the generation of scraps.

[0008] Furthermore, for clad materials, which are composite materials in which one metal is bonded to the periphery of another metal, there is a need for a method for manufacturing metal components that have a rectangular cross section and an in-plane bent shape, including conductive components, while suppressing the occurrence of uneven thickness, etc. [Means for solving the problem]

[0009] The means for solving the above problems are as follows.

[0010] (1) Bending a metal material in a predetermined bending direction; The metal material that has been bent is subjected to a compression process in a compression direction that reduces the thickness of the bent portion formed by the bending process; a cross-sectional ratio b1 / h1, which is a ratio of a width b1 in the direction of the bending radius to a thickness h1 in a direction perpendicular to the width b1, in a cross section of the bent portion of the metal material along the direction of the bending radius, of 1 or more and 65 or less.

[0011] (2) The method for producing a conductive member according to (1) above, wherein the metal material is a rod-shaped or wire-shaped material having a circular or rectangular cross section.

[0012] (3) The method for manufacturing a conductive member described in (1) above, characterized in that the conductive member has a bending radius ratio R1 / b1, which is the ratio of the bending radius R1 of the bending portion to the width b1 at the bending portion, of 0.4 or more and 20 or less, and the bending radius R1 is the bending radius up to the center position of the width b1.

[0013] (4) The method for manufacturing a conductive member according to (1) above, wherein the metal material is one of iron, aluminum, copper, titanium, magnesium, nickel, silver, gold, cobalt, and tungsten, or an alloy containing any of these metals.

[0014] (5) The method for manufacturing a conductive member according to (1) above, wherein the metal material is a clad material having a first metal and a second metal covering the first metal.

[0015] (6) The method for manufacturing a conductive member according to (1) above, wherein the predetermined bending direction is a direction in which the moment of inertia of the area of ​​the metal material becomes smaller.

[0016] (7) The method for producing a conductive member according to (1) above, wherein the compression processing is press processing or rolling processing using a rolling roll.

[0017] (8) The method for producing a conductive member according to (1) above, wherein the die used for the compression process is a flat die having a smooth compression surface that contacts the metal material.

[0018] (9) The method for manufacturing a conductive member described in (1) above, characterized in that the mold used for the compression processing is a mold having a rectangular recess on the compression surface that comes into contact with the metal material, the recess matching the cross-sectional shape of the conductive member to be produced.

[0019] (10) A method for manufacturing a conductive member according to (1) above, characterized in that the metal material is annealed after the bending process, and the compression process is performed on the annealed metal material.

[0020] (11) The method for manufacturing a conductive member described in (1) above, wherein the compression processing is press processing, and the metal material that has been bent is compressed by press processing in multiple steps.

[0021] (12) The compression amount S, which is the difference (h0-h1) between the thickness h0 of the metal material before the compression process and the thickness h1 of the metal material after the compression process c The compression ratio S is the ratio of the thickness h0 before compression to the thickness h0 before compression. c / h0 is 0 c The method for producing a conductive member according to (1) above, wherein / h0≦0.95.

[0022] (13) Bending a clad material having a first metal and a second metal covering the first metal in a predetermined bending direction; The bent clad material is compressed in a direction that reduces the thickness of the bent portion formed by the bending process; A method for manufacturing a metal component, characterized by producing a metal component having a cross-sectional shape in which the cross-sectional ratio b1 / h1, which is the ratio of the width b1 in the direction of the bending radius to the thickness h1 in a direction perpendicular to the width b1, is 1 or more and 65 or less in a cross-section along the direction of the bending radius of the bent portion of the clad material. [Effects of the Invention]​

[0023] It is possible to provide a method for manufacturing conductive members and the like using bending, which can suppress the occurrence of deformation such as uneven thickness and prevent the generation of scrap material. [Brief explanation of the drawings]

[0024] [Figure 1] 3A to 3C are schematic diagrams illustrating the flow of a method for manufacturing a conductive member according to the present embodiment. [Figure 2] FIG. 10 is a schematic view showing an example of another mold according to the present embodiment. [Figure 3] FIG. 1 shows the shape and dimensions of each sample in the examples and photographed images of each sample. [Figure 4] 1 shows images of the bent portion of each sample in the examples. [Figure 5] 1 shows images of the bent portion of each sample in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0025] (First embodiment) The method for manufacturing a conductive member according to this embodiment will be described with reference to the drawings. Fig. 1 is a schematic diagram illustrating the method for manufacturing a conductive member according to this embodiment. The conductive member according to this embodiment can be manufactured by bending and compressing a metal material. Specifically, the metal material is first subjected to a) bending, and then b) compression.

[0026] A conductive member is a member that passes current from one position to another in various devices and equipment. The manufacturing method of this embodiment makes it possible to manufacture a conductive member with a cross-sectional shape that is highly space-efficient. For example, a conductive member with a rectangular cross-sectional shape can be manufactured. Specifically, the conductive member may be a bus bar. A bus bar is a conductor that passes large amounts of high-voltage current in various devices and equipment such as distribution boards, control panels, operation panels, power conversion devices, motors, secondary battery modules, and secondary battery packs. Of course, the conductive member is not limited to a bus bar, and may be other electrical components, power transmission components, conductors, etc. that pass current in equipment, etc.

[0027] The metal material used to fabricate the conductive member can be a conductive metal that can be bent and compressed. The metal material can be in the form of a rod (or wire). The cross-sectional shape of the metal material can be, for example, circular or rectangular. The cross-sectional dimensions and area of ​​the metal material, as well as the length of the material used, can be determined appropriately depending on the dimensions of the conductive member to be finally fabricated.

[0028] The metallic material may be any metal that is solid at room temperature, and may be an elemental metal or an alloy. The elemental metal may be, for example, iron, aluminum, copper, titanium, magnesium, nickel, silver, gold, cobalt, or tungsten. The alloy may be an alloy containing any of the above-mentioned metals. For example, aluminum alloys, copper alloys, etc. may be used, but are not limited to these. Metals other than those exemplified here may also be used as the metallic material.

[0029] The shape of the metal material is not particularly limited, and can be a round bar or wire with a circular cross section, or a square bar or wire with a rectangular cross section. Standardized materials can also be used for these bar and wire materials. Figure 1 shows an example of a round bar with a circular cross section. The circular cross section can be a circle, an ellipse, or an oval. The rectangular cross section can be a square or a rectangle other than a square. Materials with polygonal cross sections (e.g., trapezoid, hexagon, octagon) other than a rectangle can also be used. Regarding the cross-sectional area of ​​the metal material, a metal material with an appropriate cross-sectional area corresponding to the cross-sectional area of ​​the conductive component to be fabricated can be used. Regarding the length of the metal material, a material with a length that corresponds to the length of the conductive component to be fabricated can be used. If the length is adjusted by machining, such as cutting, after compression, a longer metal material can be used initially.

[0030] A method for manufacturing a conductive member according to this embodiment will now be described. As described above, a conductive member can be manufactured by a) bending and b) compression. First, in the bending step a) a suitable bending method is used to bend a metal material in a predetermined bending direction to form a bent portion of a desired shape. The bending method is not particularly limited, and suitable methods such as press bending, rotary draw bending, and roll bending can be used. Bending may be performed on multiple locations of the metal material within the same plane to form multiple bent portions.

[0031] The predetermined bending direction is preferably the direction that minimizes the moment of inertia when bending a metal material. For example, if the cross-sectional shape of a metal material is elliptical, where the major axis is h0 and the minor axis is b0, it is preferable to bend the metal material in the direction of the minor axis (b0), as in the example shown in Figure 1. Similarly, if the cross-sectional shape is rectangular (excluding square), it is preferable to bend the metal material in the direction of the short side. If the cross-sectional shape is square, it is preferable to bend the metal material in the direction along one of the sides. Bending the metal material in the direction that minimizes the moment of inertia makes it easier to bend, allowing it to bend into a shape with a smaller bending radius. Furthermore, cracking and other problems can be prevented during bending. Note that, if the moment of inertia is the same regardless of the bending direction, as in the case of a perfectly circular cross-sectional shape, any bending direction is acceptable. Furthermore, in-plane bending may be performed during this a) bending process depending on conditions such as the bending radius. This is because even if thickness deviations or other issues occur during bending, the cross-section can be made uniform by b) compression processing, as described below.

[0032] The bending angle of the metal material is not particularly limited, and it can be bent to any angle greater than 0°. For example, there is no upper limit to the bending angle as long as the metal material is bent into a shape that does not overlap in the compression direction, such as a spiral shape.

[0033] Next, in the compression process (b), the metal material that has been bent (a) is compressed. The compression direction of the compression process can be the direction that reduces the thickness of the metal material that has been bent. The thickness of the metal material is the thickness in a direction perpendicular to the surface including the bent portion formed by the bending process. More specifically, the compression process can be performed with the direction perpendicular to the surface including the bent portion formed by the bending process as the compression direction. In the example of Figure 1, in the cross section of the metal material along the bending radius direction, the compression direction is the direction of the diameter (thickness) h0 of the metal material, which is perpendicular to the direction of the diameter (width) b0 of the metal material in the bending radius direction.

[0034] The compression direction is not limited to a direction perpendicular to the surface including the bent portion, but may be any direction that reduces the thickness, and compression can also be performed at an angle. For example, the compression surface of the mold can be inclined to compress from the outside of the bend toward the inside. In this case, the material can be prevented from spreading. This prevents the bend radius from increasing due to compression, allowing for processing to a smaller bend radius.

[0035] The compression method may be any suitable method capable of compressing the bent metal material to the desired thickness, and is not particularly limited. Specifically, press processing or rolling using a rolling roll (roll press processing) can be used. In the press processing method, the bent metal material is placed between upper and lower dies and compressed using a processing machine (press) until it reaches the desired thickness. As shown in FIG. 1, a flat die 10 having smooth compression surfaces that contact the metal material of the upper and lower dies can be used for press processing. As another example, a die having a groove shaped to match the cross-sectional shape of the final conductive member may be used. FIG. 2 shows a schematic diagram of the cross-sectional shape of a die 20 as an example of such a die. As shown in FIG. 2, the die 20 has a rectangular recess 22 that matches the rectangular cross-sectional shape of the conductive member to be produced. The recess 22 is a groove formed on the surface of the die 20 in a shape (e.g., a U-shape) that matches the shape of the conductive member to be produced in a plan view.

[0036] The shape of the mold to be used can be selected appropriately. For example, when a wire rod having a circular cross section is used as the metal material and is to be compressed more accurately into a predetermined rectangular shape, it is preferable to use a mold having a recess of a predetermined rectangular shape. On the other hand, when it is not necessary to precisely compress the circular wire rod into a predetermined rectangular shape and it is sufficient to compress it to a predetermined thickness, a smooth, flat mold may be used. When a wire rod having a rectangular cross section is used as the metal material, an appropriate mold may be used depending on the cross-sectional shape to be produced.

[0037] When compression is performed by rolling, which is another method, the metal material can be compressed using an appropriate rolling device. The rolling rolls used for rolling may be ordinary cylindrical rolls or disk-shaped rolls, or caliber rolls (grooved rolls) with grooves on the roll surface.

[0038] The cross-sectional shape of the conductive member after compression can be any suitable shape and is not particularly limited. For example, it can be a rectangular shape, an elliptical shape, an oval shape, or the like. In the case of a rectangular shape, the four corners may be rounded or chamfered. Furthermore, when compressed using a mold with a smooth surface, the material moves and spreads outward from the cross section, so the cross-sectional shape may be composed of a straight portion in contact with the mold and curved portions on both sides that curve outward.

[0039] In the above b) compression processing, metal materials are processed by compressive deformation, which is easier to deform than other processing methods, so the cross-sectional ratio can be easily increased. Furthermore, when forming using conventional in-plane bending, the higher the cross-sectional ratio, the more likely it is that uneven thickness and cracks will occur. In contrast, in the method of this embodiment, compression processing is performed after bending, so the cross-sectional ratio can be increased without the limitations of in-plane bending. As a result, a conductive member with a higher cross-sectional ratio can be obtained than when formed using in-plane bending.

[0040] In the example of FIG. 1, the cross-sectional area ratio is expressed as b1 / h1, where b1 is the width of the cross-section of the bent portion of the metal material (conductive member) after compression, and h1 is the thickness. This cross-section is along the direction of the bending radius of the bent portion. Width b1 is the width of the metal material in the direction of the bending radius of the cross-section, and thickness h1 is the thickness of the metal material in a direction perpendicular to width b1. The cross-sectional area ratio b1 / h1 of the metal material (conductive member) after compression can be 1 or more and 65 or less. In the case of in-plane bending, thickness unevenness is likely to occur when the cross-sectional area ratio is 1 or more. However, in the manufacturing method of this embodiment, thickness unevenness that occurs with in-plane bending does not occur, so the cross-sectional area ratio can be processed to 1 or more. Furthermore, the upper limit can be at least a cross-sectional area ratio of 65. Furthermore, the cross-sectional area ratio b1 / h1 can be 1 or more and 30 or less.

[0041] During compression, a lubricant can be used between the metal material and the die after bending. Grease or press oil can be used as the lubricant. The use of a lubricant is expected to improve the fluidity of the metal material, allowing for smoother compression.

[0042] Compression ratio S of metal materials in compression processing c / h0 is 0 c / h0≦0.95. c / h0 is the amount of compression S relative to the thickness h0 of the metal material before compression. c The compression amount S c is the difference in thickness of the metal material before and after compression. In other words, if the thickness after compression is h1, S c = h0 - h1. The lower limit of the compression ratio is 0 c / h0. Furthermore, the compression ratio S c / h0 is 0 c / h0≦0.90.

[0043] ​​​According to the manufacturing method of this embodiment, a conductive member having a bent portion with a bend radius ratio R1 / b1 of 0.4 to 20 can be fabricated. The bend radius ratio R1 / b1 is the ratio of the bend radius R1 at the bent portion of the fabricated conductive member to the cross-sectional width b1. As described above, the cross-sectional width b1 is the width along the direction of the bend radius. As shown in Figure 1, the bend radius R1 is the bend radius from the center of the bend to the center position of the width of the conductive member. The minimum bend radius ratio of 0.4 is significantly smaller than the minimum bend radius ratio achieved by in-plane bending. Table 1 shows the forming limit values ​​for various conventional in-plane bending processes (Reference: "New Plastic Processing Technology Series 14: Press Forming of Sheet Materials - Fundamentals and Applications of Bending and Drawing," edited by the Japan Society for Technology of Plasticity, Corona Publishing Co., Ltd., 2020, p. 260). As shown in Table 1, the minimum bend radius ratio R1 / b1 achieved by conventional in-plane bending is 2. Therefore, the method of this embodiment makes it possible to produce a conductive component having a bent portion with a significantly smaller bend radius ratio for a metal material of the same cross-sectional shape. Furthermore, the "α" listed in the bend radius ratio column for tensile bending in Table 1 is the limit value for the bend angle. In contrast, with the method of this embodiment, as mentioned above, there is no particular restriction on the bend angle. The upper limit of the bend radius ratio is not particularly limited, but it can be formed, for example, in the range of 20 or less. Furthermore, the bend radius ratio R1 / b1 can preferably be 0.5 or more and 20 or less.

[0044] [Table 1]

[0045] In Table 1, L1 / b1 is the limit value of the forming length in bending. L1 is the length of the metal material to be bent, and b1 is the width of the cross section as described above. In the method of this embodiment, there is no particular limit on the length of the metal material, and there is no limit on the forming length L1 / b1. The reason for this is that, unless the bending is in-plane bending, there is no limit on the processing length as in in-plane bending. Furthermore, in compression processing, processing is possible as long as the mold is made to match the length and size of the metal material, so there is no limit on the processing length. Therefore, in the method of this embodiment, it is possible to produce longer conductive members than in conventional in-plane bending.

[0046] The above b) compression process may be performed on the entire metal material or on a portion of it. It is sufficient to perform compression on at least the portion including the bent portion formed by bending. After compression, appropriate processing may be performed to change or adjust the shape, dimensions, etc. to form the final conductive member. For example, bending, cutting, polishing, etc. may be performed after compression.

[0047] Furthermore, compression by pressing can be performed in multiple steps (partial sequential compression). That is, the area to be compressed of the metal material can be divided into multiple sections, and the pressing process can be performed multiple times to compress the entire object. In the case of the round bar material shown in Figure 1, for example, pressing can be performed in three steps: first on the straight section, then on the straight side of the bent section, and finally on the tip of the bent section. By compressing each section of the conductive material in this way, a high cross-sectional area ratio can be achieved even with a press machine with a small load capacity. Another method of performing compression in multiple steps is to first press and compress the area including the bent section, and then press the rest of the section. This method allows for forming a high cross-sectional area ratio with a smaller bending radius. Furthermore, when performing compression in multiple steps, the cross-sectional area ratio can be intentionally increased or decreased in some areas compared to other areas, thereby varying the cross-sectional shape of the conductive material at different locations.

[0048] The effects of the manufacturing method for a conductive member according to the present embodiment are now described. First, in the method of this embodiment, a metal material is bent before being formed into a plate-like shape with a high cross-sectional ratio, and then compressed. This allows for the production of a conductive member with a bent portion having a smaller bending radius than when a metal material of the same cross-sectional shape and dimensions is produced by in-plane bending. Furthermore, by bending the metal material in a direction that has a smaller moment of inertia in the cross-sectional shape, a shape with an even smaller bending radius can be produced. Furthermore, according to the method of this embodiment, when producing a conductive member with such a small bending radius, no scrap material is generated, as occurs with cutting methods, and material waste is reduced. Furthermore, since compression is performed after bending, even if thickness unevenness (thickness unevenness) occurs in the material during bending, the unevenness can be eliminated by compression during compression. Therefore, a conductive member with a bent portion bent in the width direction of a plate-like shape with reduced thickness unevenness can be obtained.

[0049] Furthermore, according to the method for manufacturing a conductive member of this embodiment, it is possible to manufacture a conductive member having electrical performance (electrical resistance value) equivalent to that of a conductive member of the same shape manufactured by other conventional methods. Specific evaluation of the electrical performance (electrical resistance value) of the conductive member according to this embodiment will be further described in the examples.

[0050] In this embodiment, the bent metal material is compressed, but the bent metal material may be annealed before compression. Annealing before compression makes compression easier. Annealing may be performed during compression, and then further compression may be performed.

[0051] Furthermore, although a rod-shaped (or wire-shaped) metal material is used in this embodiment, a tubular metal material can also be used. A tubular metal material can be similarly bent and compressed using the method described in this embodiment to produce a flat tubular member having a bent portion in the width direction. This tubular member can be used as a conductive member as well as a heat transfer tube, a pipe, a waveguide, etc.

[0052] (Second embodiment) A second embodiment will be described. This embodiment is an embodiment in which the metal material to be bent and compressed is a clad material. It should be noted that a suitable manufacturing method for the clad material according to this embodiment, which suppresses deformation such as uneven thickness, has been sought for not only conductive members but also plate-like members in general that have an in-plane bent shape. Therefore, the clad material described in this embodiment provides a method for manufacturing metal members that can be used for various applications, including conductive members, using the method described in the first embodiment. Metal members manufactured by the method of this embodiment include, for example, conductive members such as bus bars, as well as edgewise coils, other structural rectangular (irregular cross-section) coils, and buildings (channel members), but are not limited to these applications.

[0053] A clad material is a composite material formed by bonding multiple metals. In this embodiment, a clad material having a first metal core (inside) and a second metal coating covering the first metal can be used. The first and second metals can be different types of metals, or a combination of metals of the same type can be used. In this embodiment, a material with a circular cross section in which the first and second metals are bonded coaxially can be used as the clad material. Note that the clad material may not only be a combination of two types of metals, but may also be a clad material connecting three or more types of metals (e.g., a third metal, a fourth metal, etc.) (e.g., a multi-layer structure with a triple or higher layer structure). Furthermore, the cross section of the clad material is not limited to a circular shape; a clad material with a polygonal cross section, such as a rectangle, can also be used. The multiple metals do not need to be arranged coaxially and may be eccentric. For example, in the case of a circular material, the center of the first metal inside the second metal may be offset from the center of the second metal. Furthermore, the inner first metal and the outer second metal may have different cross-sectional shapes, for example, the first metal may be circular and the second metal may be rectangular.

[0054] Furthermore, in addition to solid clad materials, tubular clad materials can also be used. That is, tubular clad materials having a tubular first metal and a second metal covering the outer periphery of the first metal can be used. When using tubular clad materials, it is possible to fabricate bent pipes with a flat cross section and a double structure. Such bent pipes can be used, for example, in heat exchangers and piping for transportation machinery.

[0055] The metals constituting the clad material are not particularly limited. For example, a combination of the metals and alloys described in the first embodiment can be used. For example, a combination of copper and aluminum can be used as a clad material combination. Either of these combined metals may serve as the core (inner) or the covering. For example, when producing a conductive component, the first metal and the second metal of the covering can be selected according to the required performance (electrical performance, mechanical performance, physical performance, etc.). When producing a metal component for other purposes, the metals can be selected according to the functions required for that purpose. The overall diameter of the cross section of the clad material, the dimensions (diameter) of the first metal, and the dimensions (thickness) of the second metal are not particularly limited and can be set appropriately depending on the purpose, performance, etc. Furthermore, when three or more metals are combined, or similarly, appropriate metals can be selected depending on the required performance and purpose. Furthermore, when three or more metals are combined or when the cross-sectional shape is polygonal, the dimensions (diameter, width, thickness, etc.) of each metal can also be set appropriately. The second embodiment is the same as the first embodiment except that a clad material is used as the metal material, and metal members such as conductive members can be manufactured using the same manufacturing method.

[0056] That is, a method for manufacturing a metal component using a clad material includes bending a clad material having a first metal and a second metal covering the first metal in a predetermined bending direction, The bent clad material is compressed in a direction that reduces the thickness of the bent portion formed by the bending process; The method is characterized in that a metal component is produced having a cross-sectional shape in which a cross-sectional ratio b1 / h1, which is the ratio of a width b1 in the direction of the bending radius of the bent portion of the clad material to a thickness h1 in a direction perpendicular to the width b1, is between 1 and 65. The compression direction can be perpendicular to a plane including the bent portion.

[0057] In the above-mentioned method for manufacturing a metal member, the metal member can be characterized in that a bend radius ratio R1 / b1, which is the ratio of the bend radius R1 of the bent portion to the width b1 of the bent portion, is 0.4 to 20, and the bend radius R1 is the bend radius to the center position of the width b1. In the above-mentioned method for manufacturing a metal member, the predetermined bending direction can be a direction in which the moment of inertia of the area of ​​the metal material becomes smaller. In the above-mentioned method for manufacturing a metal member, the compression processing can be press processing, and the bent metal material can be compressed by performing press processing multiple times.

[0058] According to the above-described embodiment, it is possible to produce a clad metal component having an in-plane bent shape, which has been difficult to produce in the past. Specifically, in the past, a clad metal component having a bent portion was produced by in-plane bending or cutting a clad plate made of laminated metal plates. In this case, since the first metal is exposed at the edges of the original clad plate, the first metal (middle portion) of the produced metal component is also exposed at the edges. However, according to the method of the present embodiment, it is possible to produce a clad metal component having an in-plane bent shape with closed edges, in which the entire periphery of the first metal (middle portion) is covered with the second metal. [Example]

[0059] (Example 1: Preparation of conductive member) The embodiments are further described with reference to examples. First, an example will be described in which conductive members were actually fabricated using the bending compression method described in the embodiments, and the bending radius ratio and cross-sectional ratio were confirmed. The conductive members were fabricated using metal materials with a length of 100 mm, with the material, cross-sectional shape, and cross-sectional dimensions (width b0 and thickness h0 in the bending direction) shown in Table 2. Since the cross-sectional shapes of all materials were circular or square, the cross-sectional dimensions of width b0 and thickness h0 were the same. For circular cross sections, the cross-sectional dimensions were the diameter, and for square cross sections, the width (or thickness) parallel to the sides was the diameter. First, the metal materials were bent. For the bending process, an NC table bender (NWB-8S, manufactured by Kyodo Engineering Co., Ltd.) was used to wrap each metal material around a rod-shaped die with a diameter of 8 mm and bend it to an angle of 190°. Next, the bent metal materials were compressed. Compression was performed using a universal testing machine (UEH-50, manufactured by Shimadzu Corporation) to compress the bent metal materials from above and below using a die. The die used was a die made of pre-hardened steel GO40F (GO40F-4F2RG-BS-NNN-109.9-109.9-10, manufactured by Misumi Corporation) with a smooth compression surface, similar to die 10 shown in Figure 1. The compression conditions were as follows: high-temperature, extreme-pressure grease (manufactured by Super Lube Co., Ltd.) was applied to the metal material, and 50 μm-thick Naflon tape (manufactured by Nichias Corporation) was applied to the die side for lubrication (only No. 7 was unlubricated), and the compression speed was 1 mm / min at room temperature.

[0060] The above steps were used to obtain samples of each conductive member. The bending radius R1, thickness h1, and width b1 of the bent portion of the conductive member were measured. The bending radius R1 is the bending radius up to the widthwise center of the bent portion of the conductive member. Specifically, images of the bent portion were photographed using a digital microscope (VHX-5000, manufactured by Keyence Corporation) and processed to draw arcs passing through three arbitrary points on the outer diameter of the bent portion and arcs passing through three arbitrary points on the inner diameter. The average value of the radii of these arcs was used to determine the bending radius R1 of the bent portion of the conductive member. The width b1 was also measured from images of the bent portion photographed using the same digital microscope. The thickness h1 was determined by measuring the thickness of the bent portion of the prepared conductive member using a digital caliper (IP-67, manufactured by MICROTECH). The compression amount S during compression processing for each sample was calculated from the measured values. c The compression amount S c was calculated from the difference in thickness of the metal material before and after pressing (h0-h1). c and the thickness before compression h0, the compression ratio S c The bending radius ratio R1 / b1 and the cross-sectional ratio b1 / h1 were calculated from the measured values. The calculated values ​​are shown in Table 2.

[0061] [Table 2]

[0062] For all samples, we were able to achieve a bending radius ratio that was significantly smaller than the limit value for conventional in-plane bending (see Table 1). We also confirmed that the cross-sectional ratio could be fabricated within the range of 1 to 65. Furthermore, for all samples, we were able to confirm that defects such as deformation due to uneven thickness or cracks did not occur in the bent section, and that conductive components with no variation in cross-sectional shape could be fabricated.

[0063] (Example 2: Measurement of electrical resistance of conductive member) Next, conductive members were fabricated from a plurality of materials using the bending and compression processing method described in the embodiment. Additionally, as a comparative example, conductive members of the same material, dimensions, and shape were fabricated by cutting from a plate material. The electrical resistance values ​​of the fabricated samples were measured and compared.

[0064] Table 3 shows the shape type, material, and forming method of each sample prepared. The materials used were copper (C1020, C1100) and aluminum (A1050, A1070). As for aluminum, different standards are used for sheet and bar materials, so A1050 was used for the plate material and A1070 for the bar material. Although the purity of both types differs slightly, they are both defined as pure aluminum in the JIS standard and share the same properties and applications. The dimensions and shapes of the prepared samples, shapes A, B, and C, are shown in Figure 3. The dimensions shown in Figure 3 are in mm. The thickness of each sample was 1 mm for shape A, and 2 mm for shapes B and C.

[0065] The samples (Nos. 18, 20, 22, 24, and 26) for the method of this embodiment (bending and compression processing method) were produced by bending and compressing rod-shaped metal materials with a circular cross-sectional shape and cross-sectional dimensions (diameter) of 2 mm for Shape A, and 4 mm for Shapes B and C. Shape A was wrapped around a rod-shaped die with a diameter of 8 mm, Shape B around a rod-shaped die with a diameter of 6 mm, and Shape C around a rod-shaped die with a diameter of 16 mm, and each was bent to 190°. The bent metal materials were then subjected to compression processing. Compression processing was performed by compressing the metal materials from above and below using dies in a universal testing machine, as in Example 1.

[0066] The comparative samples (Nos. 17, 19, 21, 23, and 25) were produced by wire electric discharge machining. Specifically, a plate material having the thickness of each sample shape (shape A: 1 mm, shapes B and C: 2 mm) was subjected to wire electric discharge machining using a fine cutter (RCA-234, manufactured by Refine Tech Co., Ltd.) to cut out conductive members with the dimensions and shapes shown in Figure 3.

[0067] The electrical resistance was measured using a nanovolt microohmmeter (34420A, manufactured by Keysight Technologies, Inc.) with current terminals attached to the end of the sample. Resistance measurement terminals were attached to a straight section 30 mm from the apex of the bent section in the longitudinal direction of the sample (the vertical direction in Figure 3 ). A small current was passed through the section and the electrical resistance was measured. As in Example 1, the bending radius R1, thickness h1, and width b1 of the bent section of the obtained conductive member were measured, and the bending radius ratio R1 / b1 and cross-sectional ratio b1 / h1 were calculated. The bending radius R1 is the bending radius up to the center of the bent section in the width direction. These values ​​are shown in Table 3. Images of each of the prepared samples are also shown in Figure 3.

[0068] [Table 3]

[0069] As shown in Table 3, the conductive member manufactured by the manufacturing method of this embodiment has an electrical resistance value R e It was therefore confirmed that the method of this embodiment can produce an in-plane bent conductive member having conductivity equivalent to that produced by the cutting method, with almost no difference (even if there is a difference, it is within 0.1 mΩ), and the same electrical resistance value can be achieved.

[0070] (Example 3: Example of manufacturing a clad metal member) Metal components were fabricated using clad material as the metal material. The clad material used was a wire with a circular cross section, consisting of a core first metal (aluminum (A1070)) and a cladding second metal (copper (C1020)). The cross-sectional dimensions of the clad material were an outer diameter of 4 mm, a first metal diameter of 3.2 mm, and a second metal thickness of 0.4 mm. The clad material was wrapped around a rod-shaped die with a diameter of 8 mm and bent to an 80° bend angle. Compression was performed using a die with a universal testing machine, compressing the metal material from above and below using a die, as in Example 1. The die had a smooth compression surface, such as die 10 shown in Figure 1. The compression amount Sc, bending radius R1, bending radius ratio R1 / b1, and cross-sectional ratio b1 / h1 of each fabricated sample during compression are shown in Table 4. The bending radius R1 is the bending radius up to the center of the bent portion in the width direction. Also, photographs of the fabricated samples are shown in Figure 4. In addition, the same clad material was wrapped around a rod-shaped die with a diameter of 16 mm, bent at a bending angle of 210°, and similarly compressed to produce samples, which are shown in Table 5 and Figure 5.

[0071] [Table 4]

[0072] [Table 5]

[0073] As described above, when metal components were fabricated from clad materials using the method described in this embodiment, metal components with various bending radii and cross-sectional ratios could be fabricated. Furthermore, no deformation such as uneven thickness was observed in any of the metal components, and metal components with no variation in cross-sectional shape could be fabricated. [Explanation of symbols]

[0074] 10, 20 mold

Claims

1. Perform bending on the metal material in a predetermined bending direction, Perform compression on the metal material that has undergone the bending in a compression direction that reduces the thickness of the bent portion formed by the bending, The width b in the direction of the bending radius in a cross-section along the direction of the bending radius of the bent portion of the metal material １ and the width b １ and the thickness h in the direction perpendicular to the width b １ and the cross-sectional ratio b １ / h １ is a method for manufacturing a conductive member, characterized by manufacturing a conductive member having a cross-sectional shape of 1 or more and 65 or less

2. The method for manufacturing a conductive member according to claim 1, wherein the metal material is a rod-shaped or wire-shaped material having a circular or rectangular cross-sectional shape.

3. The conductive member has a bending radius R of the bending portion １ and a width b of the bending portion １ The bending radius ratio R, which is the ratio of the two １ / b １ is 0.4 or more and 20 or less, and the bending radius R １ is the bending radius to the center position of the width b １ The method for manufacturing a conductive member according to claim 1, characterized in that

4. The method for manufacturing a conductive member according to claim 1, wherein the metal material is any one of iron, aluminum, copper, titanium, magnesium, nickel, silver, gold, cobalt, tungsten, or an alloy containing any of these metals.

5. The method for manufacturing a conductive member according to claim 1, wherein the metal material is a clad material having a first metal and a second metal that coats the first metal.

6. The method for manufacturing a conductive member according to claim 1, wherein the predetermined bending direction is a direction in which the second moment of area of the metal material becomes smaller.

7. The method for manufacturing a conductive member according to claim 1, wherein the compression is performed by press working or rolling with a rolling roll.

8. The method for manufacturing a conductive member according to claim 1, wherein the die for performing the compression is a flat die with a smooth compression surface that contacts the metal material.

9. The method for manufacturing a conductive member according to claim 1, wherein the die for performing the compression has a rectangular recess on the compression surface that contacts the metal material, which is adapted to the cross-sectional shape of the conductive member to be manufactured. [[ID= ​ ​ ​ ​ The thickness h of the metal material before the compression processing ０ and the thickness h after the compression processing １ The difference (h ０ -h １ ) is the compression amount S ｃ The compression ratio S ０ which is the ratio of the compression amount S to the thickness h before the compression processing ｃ / h ０ is such that 0 < S ｃ / h ０ ≦0.

95. The method for manufacturing a conductive member according to claim 1, characterized in that. ​ ​ ​ The width b in the direction of the bending radius in a cross-section along the direction of the bending radius of the bent portion of the clad material １ and the width b １ and the thickness h in a direction perpendicular to the width b １ and the cross-sectional ratio b １ / h １ A method for manufacturing a metal member, characterized in that a metal member having a cross-sectional shape with a cross-sectional ratio of 1 or more and 65 or less is produced.

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