Patent Application
20190358749
The present invention relates to a technology for cutting a long conductive member to manufacture a conductive member that is used as a wiring material or the like in a vehicle.
As disclosed in Patent Literature 1, a wiring material in a vehicle or the like is manufactured by connecting an end portion of an electrical wire to a terminal or another electrical wire.
In addition to a generic electrical wire, a braided wire in which metal wire is braided into a tubular shape or the like may also be used as the wiring material. In either case, the generic electrical wire and braided wire are both manufactured in a form that is long and continuous, and therefore when manufacturing the wiring material, a step of cutting the braided wire or a core wire contained in the electrical wire is essential.
Patent Literature 1: Japanese Patent Laid-open Publication No. 2013-004411
In this regard, cutting an elongated conductive member with a high energy-density beam such as a laser beam is investigated by the inventors of the present application.
However, as illustrated in
Specifically, the laser beam 910 is absorbed by a portion close to a surface at which the laser beam 910 is fired, and heating is centered on this portion. In addition, from a vantage point of constraining equipment costs, cutting that uses a laser beam seeks to cut a member using a lower output. Because of this, due to the material or thickness of a member, there may be cases where there is difficulty adequately heating an interior of the conductive member 900 to reach the melting point thereof in an initial period portion of the displacement path of the laser beam 910. Meanwhile, in a region where the laser beam 910 has displaced a certain amount, the heat imparted to the displacement path of the laser beam 910 up to that point builds up cumulatively, and therefore the interior of the conductive member 900 can be adequately heated to reach the melting point thereof.
Therefore, when the laser beam 910 moves along the width direction of the conductive member 900, a cuttable depth D that can be cut by the laser beam 910 exhibits characteristics of being smaller in the initial period of the displacement path and, as the laser beam 910 advances, of gradually increasing and finally stabilizing.
Therefore, as illustrated in
In order to cut the conductive members 900A and 900B in the initial period of the displacement path of the laser beam 910, cases may be considered where the laser beam 910 is configured to a higher output, the displacement speed of the laser beam 910 is slowed, or the like to increase the energy density imparted per unit area. However, this gives rise to a need for using an expensive laser device that is capable of high output, invites a shortened lifespan of a laser device as a result of continuous laser emission at a setting close to the maximum output of the laser device, lengthens the time required for cutting, and the like.
In view of this, the present invention is configured to enable a long conductive member to be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
In order to resolve the above-noted issues, a method of manufacturing a conductive member according to a first aspect includes (a) a step of preparing a long conductive member provided with a cutting target in an extension direction portion, and (b) a step of firing a high energy-density beam at the cutting target while moving the high energy-density beam in a direction that intersects with the extension direction of the long conductive member, and also cutting the cutting target at, at least, a portion where the high energy-density beam moves, such that a dimension of the cutting target in a firing direction of the high energy-density beam gradually increases.
A second aspect is the method of manufacturing the conductive member according to the first aspect in which, in step (a), an extension direction portion of the long conductive member is formed as the cutting target, which has a portion that is processed such that a thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction of the long conductive member, and in step (b), the high energy-density beam is fired at the cutting target while moving in the direction in which the thickness dimension gradually increases, and cuts the cutting target.
A third aspect is the method of manufacturing the conductive member according to the second aspect in which, in step (a), the extension direction portion of the long conductive member is formed as the cutting target, which has a portion that is processed such that, in a cross-sectional view orthogonal to the extension direction of the long conductive member, the thickness dimension gradually increases from two sides thereof toward a middle portion thereof.
A fourth aspect is the method of manufacturing the conductive member according to the second or third aspect in which, in step (a), the extension direction portion of the long conductive member is formed as the cutting target, which has a portion where, in a cross-sectional view orthogonal to the extension direction of the long conductive member, the thickness dimension is fixed at a width-direction middle portion thereof.
A fifth aspect is the method of manufacturing the conductive member according to any one of the second to fourth aspects in which, in step (a), the extension direction portion of the long conductive member is formed as the cutting target, in which a cross-sectional view orthogonal to the extension direction of the long conductive member exhibits a trapezoidal shape.
A sixth aspect is the method of manufacturing the conductive member according to the first aspect in which, in step (a), a cutting target is prepared which is rectangular in a cross-sectional view orthogonal to the extension direction of the long conductive member, and in step (b), the high energy-density beam is fired along a direction that is oblique with respect to four faces of the cutting target.
A seventh aspect is the method of manufacturing the conductive member according to any one of the first to sixth aspects, in which the long conductive member is a member that collects a plurality of strands to create a wire shape, and in which step (a) includes a step of applying pressure to the plurality of strands.
An eighth aspect is the method of manufacturing the conductive member according to the seventh aspect, in which step (a) includes a step of bonding the plurality of strands to each other.
A ninth aspect is the method of manufacturing the conductive member according to any one of the first to eighth aspects in which, in step (b), a displacement speed of the high energy-density beam increases partway through.
A tenth aspect is the method of manufacturing the conductive member according to any one of the first to ninth aspects, further including a step (c) in which the cutting target that is cut in step (b) is connected to a terminal.
In order to resolve the above-noted issues, a long conductive member according to an eleventh aspect is formed of a conductive material in an elongated shape, and an extension direction portion thereof is formed as a cutting target, which has a portion that is processed such that a thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction.
A twelfth aspect is the long conductive member according to the eleventh aspect, in which the cutting target is formed in a shape having a portion that is processed such that, in a cross-sectional view orthogonal to the extension direction thereof, the thickness dimension gradually increases from two sides thereof toward a middle portion thereof.
A thirteenth aspect is the long conductive member according to the eleventh or twelfth aspects, in which the cutting target is formed in a shape having a portion where, in a cross-sectional view orthogonal to the extension direction thereof, the thickness dimension is fixed at a width-direction middle portion thereof.
A fourteenth aspect is the long conductive member according to any one of the eleventh to thirteenth aspects, in which the long conductive member is a member that collects a plurality of strands to create a wire shape, and in which the cutting target is configured as a portion where pressure is applied to the plurality of strands, creating a state where the strands are more tightly packed than other portions.
A fifteenth aspect is the long conductive member according to the fourteenth aspect in which, in the cutting target, the plurality of strands are in a state of being bonded to each other.
In order to resolve the above-noted issues, a conductive member according to a sixteenth aspect is formed of a conductive material in an elongated shape; has striated thermal cutting marks made by a high energy-density beam formed on an end face on at least one side of the conductive member; and moreover, has the end face formed in a shape having a portion where a dimension along an extension direction of the thermal cutting marks gradually increases in a direction orthogonal to the extension direction of the thermal cutting marks.
A seventeenth aspect is the conductive member according to the sixteenth aspect, in which the end face is formed in a rectangular shape, and the thermal cutting marks extend in a direction that is oblique with respect to the four circumferential sides of the end face.
In order to resolve the above-noted issues, a conductive member according to an eighteenth aspect is formed of a conductive material in an elongated shape, has an end face of an end portion on at least one side thereof formed in a shape having a portion that is processed such that a thickness dimension gradually increases, and moreover, has thermal cutting marks made by a high energy-density beam formed on the end face.
A nineteenth aspect is the conductive member according to the eighteenth aspect, in which the end face is formed in a shape having a portion that is processed such that the thickness dimension gradually increases from two sides thereof toward a middle portion thereof.
A twentieth aspect is the conductive member according to the eighteenth or nineteenth aspects, in which the end face is formed in a shape having a portion where the thickness dimension is fixed at a width-direction middle portion thereof.
A twenty-first aspect is the conductive member according to any one of the sixteenth to twentieth aspects, in which the conductive member is a member that collects a plurality of strands to create a wire shape, and, at the end face, pressure is applied to the plurality of strands, creating a state where the strands are more tightly packed than other portions.
A twenty-second aspect is the conductive member according to the twenty-first aspect in which, at the end face, the plurality of strands are in a state of being bonded to each other.
A twenty-third aspect is the conductive member according to any one of the sixteenth to twenty-second aspects, in which a terminal is connected to at least one of the end portions.
According to the first aspect, the high energy-density beam is fired at the cutting target while moving the high energy-density beam in the direction that intersects with the extension direction of the long conductive member, and also the cutting target is cut at, at least, a portion where the high energy-density beam moves, such that the dimension of the cutting target in the firing direction of the high energy-density beam gradually increases, and therefore at an initial period of a displacement path of the high energy-density beam, the high energy-density beam is fired at a portion of the cutting target with a comparatively small thickness dimension. Therefore, at the initial period of the displacement path of the high energy-density beam, the cutting target can easily be completely cut even without increasing the output of the high energy-density beam or slowing the displacement speed or the like. In addition, from a midway point onward in the displacement path of the high energy-density beam, heat imparted to the displacement path of the high energy-density beam up to that point builds up cumulatively, and therefore a portion of the cutting target where the thickness dimension is comparatively large can also easily be completely cut. As a result, the long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the second aspect, the extension direction portion of the long conductive member is formed as the cutting target, which has a portion that is processed such that the thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction of the long conductive member, and the high energy-density beam is fired at the cutting target while moving in the direction in which the thickness dimension gradually increases, and cuts the cutting target. Therefore, as described with the first aspect, the long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the third aspect, the extension direction portion of the long conductive member is formed in a shape where, in a cross-sectional view orthogonal to the extension direction of the long conductive member, the thickness dimension gradually increases from two sides thereof toward a middle portion thereof. Therefore, no matter which side portion of the cutting target cutting begins from in step (b), the conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible. Also, by moving the laser beam more quickly midway along or at a terminal end of the displacement path than in the initial period of cutting, cutting can also be performed in a shorter amount of time.
According to the fourth aspect, in a state where cutting with the high energy-density beam has advanced a certain degree and the cuttable depth stabilizes somewhat, efficient cutting can be performed with the high energy-density beam.
According to the fifth aspect, the extension direction portion of the long conductive member is formed as the cutting target, in which a cross-sectional view orthogonal to the extension direction of the long conductive member exhibits a trapezoidal shape. Therefore, no matter which side portion of the cutting target cutting begins from in step (b), the conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the sixth aspect, the cutting process of step (b) can be performed on a rectangular cutting target.
According to the seventh aspect, step (a) includes the step of applying pressure to the plurality of strands, and therefore the plurality of strands are unlikely to separate at the portion where the cutting target is cut, the end portion of the conductive member.
According to the eighth aspect, the plurality of strands are bonded to each other, and therefore the strands of the end portion of the conductive member are unlikely to separate after the cutting target is cut.
According to the ninth aspect, midway along or at the terminal end of the displacement path, the cumulative heat up to that point accumulates in the material, and therefore even when the laser beam moves more quickly than in the initial period of cutting, the energy density applied to a cut portion can be equivalent to the initial period of the displacement path. Therefore, by moving the laser beam more quickly midway along or at the terminal end of the displacement path than in the initial period of cutting up to that point, cutting can be accomplished in a shorter amount of time as compared to when cutting at a fixed displacement speed.
According to the tenth aspect, the end portion of the conductive member can be connected to the terminal while inhibiting separation of the strands.
According to the eleventh aspect, the extension direction portion of the long conductive member is formed as the cutting target, which has a portion that is processed such that the thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction of the long conductive member. Therefore, when the high energy-density beam is fired at the cutting target while moving in the direction in which the thickness dimension gradually increases, the high energy-density beam is fired at a portion of the cutting target with a comparatively small thickness dimension at an initial period of the displacement path of the high energy-density beam. Therefore, at the initial period of the displacement path of the high energy-density beam, the cutting target can easily be completely cut even without increasing the output of the high energy-density beam or slowing the displacement speed or the like. In addition, from a midway point onward in the displacement path of the high energy-density beam, heat imparted to the displacement path of the high energy-density beam up to that point builds up cumulatively, and therefore a portion of the cutting target where the thickness dimension is comparatively large can also easily be cut completely. As a result, the long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the twelfth aspect, the cutting target is formed in a shape having a portion that is processed such that, in a cross-sectional view orthogonal to the extension direction thereof, the thickness dimension gradually increases from two sides thereof toward the middle portion thereof. Therefore, no matter which side portion of the cutting target cutting begins from, the conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the thirteenth aspect, in a state where cutting with the high energy-density beam has advanced a certain degree and the cuttable depth stabilizes somewhat, efficient cutting can be performed with the high energy-density beam.
According to the fourteenth aspect, the cutting target is a portion where pressure is applied to the plurality of strands, creating a state where the strands are more tightly packed than other portions, and therefore the plurality of strands are unlikely to separate at the portion where the cutting target is cut, the end portion of the conductive member.
According to the fifteenth aspect, the plurality of strands are bonded to each other, and therefore the strands of the end portion of the conductive member are unlikely to separate after the cutting target is cut.
According to the sixteenth aspect, the conductive member is formed of a conductive material in an elongated shape; has striated thermal cutting marks made by the high energy-density beam formed on the end face on at least one side of the conductive member; and moreover, has the end face formed in a shape having a portion where the dimension along the extension direction of the thermal cutting marks gradually increases in the direction orthogonal to the extension direction of the thermal cutting marks. Therefore, the high energy-density beam can be fired at the cutting target of the long conductive member while moving in the direction in which the thickness dimension gradually increases. Accordingly, at the initial period of the displacement path of the high energy-density beam, the high energy-density beam can be fired at a portion of the cutting target with a comparatively small thickness dimension. Therefore, at the initial period of the displacement path of the high energy-density beam, the cutting target can easily be completely cut even without increasing the output of the high energy-density beam or slowing the displacement speed or the like. In addition, from a midway point onward in the displacement path of the high energy-density beam, heat imparted to the displacement path of the high energy-density beam up to that point builds up cumulatively, and therefore a portion of the cutting target where the thickness dimension is comparatively large can also easily be cut completely. As a result, the long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the seventeenth aspect, the end face is formed in a rectangular shape, and the thermal cutting marks extend in a direction that is oblique with respect to the four circumferential sides of the end face. Therefore, the rectangular cutting target can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the eighteenth aspect, the portion of the long conductive member in the extension direction of the cutting target is formed as the cutting target, which has the portion that is processed such that the thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction thereof. Therefore, the high energy-density beam can be fired at the cutting target of the long conductive member while moving in the direction in which the thickness dimension gradually increases. Accordingly, at the initial period of the displacement path of the high energy-density beam, the high energy-density beam can be fired at a portion of the cutting target with a comparatively small thickness dimension. Therefore, at the initial period of the displacement path of the high energy-density beam, the cutting target can easily be completely cut even without increasing the output of the high energy-density beam or slowing the displacement speed or the like. In addition, from a midway point onward in the displacement path of the high energy-density beam, heat imparted to the displacement path of the high energy-density beam up to that point builds up cumulatively, and therefore a portion of the cutting target where the thickness dimension is comparatively large can also easily be cut completely. As a result, the long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the nineteenth aspect, the cutting target is formed in a shape having a portion that is processed such that, in a cross-sectional view orthogonal to the extension direction, the thickness dimension gradually increases from two sides thereof toward the middle portion thereof, and no matter which side portion of the cutting target cutting begins from, the conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible.
According to the twentieth aspect, in a state where cutting with the high energy-density beam has advanced a certain degree and the cuttable depth stabilizes somewhat with respect to the cutting target that is formed in a shape having a portion where the thickness dimension is fixed at the width-direction middle portion thereof, efficient cutting can be performed with the high energy-density beam.
According to the twenty-first aspect, the plurality of strands are unlikely to separate at the end portion of the conductive member.
According to the twenty-second aspect, the plurality of strands are bonded to each other, and therefore the strands of the end portion of the conductive member are unlikely to separate after the cutting target is cut.
According to the twenty-third aspect, the end portion of the conductive member can be connected to the terminal while inhibiting separation of the strands.
In the following, a method of manufacturing a conductive member, a long conductive member, and a conductive member according to a first embodiment are described.
First, a manufacturing method of a conductive member is described.
As illustrated in
As illustrated in
The cutting target 14 can be made using a metal die 20 that includes a lower mold 21 and an upper mold 24, for example. Specifically, the lower mold 21 and the upper mold 24 are members formed of a metal or the like that is a hard material with a higher melting point than the long conductive member 10. A trench-shaped lower mold surface 22 recessed downward from above is formed in the lower mold 21. In this example, the lower mold surface 22 is formed in a rectangular trench shape. A projection 25 that projects downward and that can be arranged within the lower mold surface 22 is formed on the upper mold 24. A trench 25g that opens downward is formed on a bottom end portion of the projection 25. The trench 25g is formed as a trapezoidal groove in cross-section that gradually narrows toward the top. An upper mold surface 26 is formed by two side surfaces 26a that incline upward and inward on both sides of the trench 25g, and a ceiling surface 26b that links the upper edge portions of the two side surfaces 26a.
In addition, in a state where an extension-direction middle portion of the long conductive member 10 is accommodated within the lower mold surface 22, the projection 25 presses in from above the lower mold surface 22 and applies pressure so as to compress the extension-direction middle portion of the long conductive member 10 between the lower mold surface 22 and the upper mold surface 26. When this happens, the extension-direction middle portion of the long conductive member 10 is plastically deformed, and a middle portion thereof is formed into the cutting target 14, which has a shape corresponding to the shape of the space delineated by the lower mold surface 22 and the upper mold surface 26 (see
In the present embodiment, the two side portions of the cutting target 14 are processed such that the thickness dimension gradually increases toward the width-direction middle portion thereof, but it is also possible to process only one side portion of the cutting target 14 such that the thickness dimension gradually increases toward the width-direction middle portion thereof.
In addition, the cutting target 14, when observed in the above-noted cross-sectional view, is formed as a trapezoid and therefore the width-direction middle portion of the cutting target 14 is formed at a portion where the thickness dimension is fixed. It is not strictly necessary that the thickness dimension of the width-direction middle portion of the cutting target be fixed, and therefore when observed in the above-noted cross-sectional view, the cutting target may also have a triangular shape. Cases where the cutting target 14 is formed in a trapezoidal shape include not only cases where an upper base is shorter than a lower base, but also cases where the lower base is shorter than the upper base.
Also, as illustrated in
Examples of the high energy-density beam may include a laser beam 70, an electron beam, or the like. In this example, the laser beam 70 is fired at the cutting target 14. The wavelength of the laser beam 70 is not particularly limited and, for example, laser beams of wavelengths such as 532 nm (called a green laser), 1030 nm (called a disk laser), 1064 nm (called an yttrium aluminum garnet (YAG) laser; may also be an Nd:YAG laser, which oscillates with a substance having Nd added to YAG), 1070 to 1080 nm (called a fiber laser), or the like can be used.
The laser beam 70 is fired in a direction that follows the thickness direction of the cutting target 14, cuts across the cutting target 14 from one side edge portion of the cutting target 14 (that is, from the portion where the thickness dimension is smallest), and is fired while moving so as to reach the other side edge portion of the cutting target 14. A displacement path of the laser beam 70 may follow a direction orthogonal to the extension direction of the cutting target 14, or may be a direction that is oblique relative to the extension direction of the cutting target 14. A displacement speed of the laser beam 70 is not particularly limited, and the laser beam 70 may be displaced at a fixed speed, or the displacement speed may be increased partway through. When the displacement speed of the laser beam 70 is increased partway through, cutting can be performed in a shorter amount of time.
In an initial period of displacement of the laser beam 70, the energy absorbed at the other side edge portion of the cutting target 14 from the laser beam 70 is slight. However, this portion has a small thickness dimension. Therefore, even in the initial period of displacement of the laser beam 70, the first side edge portion of the cutting target 14 can be cut adequately.
When the laser beam 70 moves toward the width-direction middle portion of the cutting target 14, the heat imparted to the laser beam 70 displacement path up to that point builds up cumulatively. Therefore, adequate heat is imparted to the cutting target 14 in conjunction with the laser beam 70 moving toward the width-direction middle portion of the cutting target 14. Therefore, a cuttable depth to which the laser beam 70 is able to cut gradually increases in conjunction with the laser beam 70 moving toward the width-direction middle portion of the cutting target 14 (see cuttable depth D in
When the laser beam 70 displaces a certain amount, once the cuttable depth that can be cut by the laser beam 70 has increased a certain amount, it is more or less fixed. Therefore, the width-direction middle portion of the cutting target 14, where the thickness direction is more or less fixed, can be adequately cut. The output and displacement speed of the laser beam 70 is preferably set to a size that enables the width-direction middle portion of the cutting target 14, where the thickness direction is more or less fixed, to be cut. However, partway through cutting, when sufficient heat has accumulated in the cutting target 14 due to the cutting up to that point, cutting speed may also be increased partway through the cutting.
By continuing to move the laser beam 70 toward the other side edge portion of the cutting target 14, cutting can be performed so as to divide the cutting target 14. The laser beam 70 may also be fired at the cutting target 14 from a portion on a wide width side (in
When the long conductive member 10 is cut at the extension-direction middle portion of the cutting target 14 as described above, a plurality of conductive members 10B can be produced, as illustrated in
The terminal 30 is a metallic plate member formed of copper, a copper alloy, or the like. A plating such as tin plating may also be formed on the surface of the terminal 30. A wire connection portion 32 is formed at one end portion of the terminal 30, and the other end portion is formed into a mating connection portion 34. The wire connection portion 32 is formed in a plate-like shape. The mating connection portion 34 is the portion to which the conductive member 10B is to be connected. In this example, the mating connection portion 34 is formed into a plate-like portion provided with a hole 34h. Also, in a state where a bolt is inserted through the hole 34h, where the bolt stands upright on a mating conductive portion (metal plate or the like) to which the mating connection portion 34 is to be connected, a nut is threadably mounted and fastened to the bolt. Accordingly, the mating connection portion 34 is held between the conductive portion and the nut, and a state can be maintained in which the mating connection portion 34 is in contact with and electrically in contact with the conductive portion. The mating connection portion 34 may have a pin- or tab-like male terminal shape, or may have a cylindrical female terminal shape.
By adding a step (step (c)) where the terminal 30 is connected to the end portion 14B of the conductive member 10B, on the cut side of the cutting target 14, the terminal-equipped conductive member 10C, which is one type of conductive member, is produced.
In this example, the end portion 14B of the conductive member 10B is welded to one principal surface of the wire connection portion 32. In this example, the wire connection portion 32 and the end portion 14B are laser welded in a state where a plane (bottom surface) on the wide width side of the end portion 14B is in surface contact with the one principal surface of the wire connection portion 32. Besides laser welding, welding of the terminal and the end portion of the conductive member may be performed with ultrasonic welding, resistance welding, or the like. Also, the terminal and the end portion of the conductive member may be soldered together. A crimping portion may also be formed on the terminal and the crimping portion may be crimped and connected to the end portion of the conductive member.
According to the above method of manufacturing the conductive member 10B, the long conductive member 10, and the conductive member 10B, an extension direction portion of the long conductive member 10 is formed as the cutting target 14, which has a portion where the thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction of the long conductive member 10. Also, a high energy-density beam such as the laser beam 70 is fired at the cutting target 14 while moving in the direction in which the thickness direction of the cutting target 14 gradually increases. Therefore, at the initial period of the displacement path of the high energy-density beam, the high energy-density beam is fired at a portion of the cutting target 14 with a comparatively small thickness dimension. Therefore, even at the initial period of the displacement path of the high energy-density beam, the side edge portion on one side of the cutting target 14 can easily be completely cut even without increasing the output of the high energy-density beam or slowing the displacement speed or the like. In addition, from a midway point onward in the displacement path of the high energy-density beam, heat imparted to the displacement path of the high energy-density beam up to that point builds up cumulatively, and therefore a portion of the cutting target 14 where the thickness dimension is comparatively large (width-direction middle portion, or the like) can easily be cut completely. As a result, the long conductive member 10 can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible. Accordingly, a low-output laser processing device can also be used, and a high-output laser processing device can be used at a low output and its lifespan can be extended.
In addition, midway along or at a terminal end of the displacement path, the cumulative heat up to that point accumulates in the cutting target 14, and therefore even when the laser beam moves more quickly than in the initial period of cutting, the energy density applied to the cut portion can be equivalent to the initial period of the displacement path. Therefore, by moving the laser beam more quickly midway along or at a terminal end of the displacement path than in the initial period of cutting up to that point, cutting can also be accomplished in a shorter amount of time as compared to cutting at a fixed displacement speed.
Also, in step (a), an extension direction portion of the long conductive member 10 is formed as the cutting target 14, which has a shaped portion where, in a cross-section orthogonal to the extension direction of the long conductive member 10, the thickness dimension gradually increases from the two sides thereof toward the middle portion thereof. Therefore, when executing step (b), even when the high energy-density beam is moved from a first side edge portion of the cutting target 14 toward a second side edge portion, and conversely even when the high energy-density beam is moved from the second side edge portion of the cutting target 14 toward the first side edge portion, the cutting target 14 can be more completely cut in as short a time as possible with a high energy-density beam having as low an output as possible.
Also, in step (a), an extension direction portion of the long conductive member 10 is formed as the cutting target 14, which has a portion where, in a cross-sectional view orthogonal to the extension direction of the long conductive member 10, the thickness dimension is fixed in the width direction of the member. When cutting with the high energy-density beam advances a certain degree, the cuttable depth stabilizes somewhat, and therefore by setting the cuttable depth to exceed (preferably, only slightly exceed) the portion of the long conductive member 10 where the thickness dimension is fixed, efficient cutting can be performed with the high energy-density beam.
In the first embodiment, the long conductive member 10 is formed in a shape where a rectangular cross-section is continuous along the extension direction of the member, but this is not strictly necessary. For example, as illustrated in
That is, a portion where an extension direction portion of a long conductive member is processed such that the thickness dimension gradually increases in a cross-sectional view orthogonal to the extension direction of the long conductive member can be said to be a portion that is processed such that a degree of thickness dimension change in the width direction of the cutting target 14 becomes more gradual as compared to other, non-processed portions (portions not forming the cutting target 14). The portion that is processed in this way, such that the degree of thickness dimension change in the width direction of the cutting target 14 becomes more gradual, is preferably formed at one or both sides of the long conductive member.
In the first embodiment, an example is described where the long conductive member is configured by a single member, but because the cutting target is a portion formed by compression with a metal die or the like, so long as the long conductive member is a member that collects a plurality of strands to create a wire shape, by forming a cutting target as described above, the external shape can be formed into the desired shape while the plurality of strands are processed into a tightly packed state and separation thereof can also be inhibited.
In the second and third embodiments that follow, examples are described where the long conductive member is a member in which a plurality of strands are collected to create a wire shape.
A method of manufacturing a conductive member, a long conductive member, and a conductive member according to a second embodiment are described. In the description of the present embodiment, configuration elements that are similar to those described in the second embodiment are assigned the same reference numerals and the explanation thereof is omitted, and the description primarily focuses on differences from the first embodiment.
First, a manufacturing method of a conductive member is described.
As illustrated in
The electrical wire 210 includes the core wire 212 and a coating 218.
The core wire 212 collects a plurality of strands 213 so as to create a wire shape. The plurality of strands 213 may be twisted together, or may not be twisted together. In this example, the strands 213 are collected such that one strand 213 is surrounded by six strands 213. Therefore, when the core wire 212 is observed in a cross-sectional view orthogonal to the extension direction, the core wire 12 creates a substantially circular external diameter. However, the number of strands is not limited to this example. Each of the strands 213 is formed of a metal wire such as aluminum, an aluminum alloy, copper, or a copper alloy. A plating such as tin plating may be formed on the surface of each of the strands 213.
The coating 218 is an insulating portion that covers a circumference of the core wire 212. The coating 218 is, for example, formed by extrusion coating or the like of an insulating material such as resin onto the circumference of the core wire 212.
The coating 218 is stripped away at the extension-direction middle portion of the electrical wire 210, forming a core wire exposure portion 212a where the core wire 212 is exposed.
As illustrated in
Step (a) in which the cutting target 214 is formed as described above preferably includes a step where the plurality of strands 213 are bonded to each other. In the present embodiment, the cutting target 214 undergoes non-pressure welding to form a cutting target 214a.
In this example, non-pressure welding refers to imparting energy from an outside source to weld each of the strands 213 to each other without applying pressure to the cutting target 214 (the welding target) from an outside source. For example, a method of striking the cutting target 214 with the high energy-density beam to perform welding, such as laser welding where the laser beam 70 is fired from a nozzle 230 onto the cutting target 214 and the strands 213 are welded to each other (see
In this example, the plurality of strands 213 are welded to each other by laser welding, in which the laser beam 70 is fired from the nozzle 230 onto the cutting target 214 and the strands 213 are welded to each other.
The wavelength of the laser beam is not particularly limited and, for example, laser beams of wavelengths such as 532 nm (called a green laser), 1030 nm (called a disk laser), 1064 nm (called an yttrium aluminum garnet (YAG) laser; may also be an Nd:YAG laser, which oscillates with a substance having Nd added to YAG), 1070 to 1080 nm (called a fiber laser), or the like can be used.
When manufacturing the bonded cutting target 214a, the cutting target 214 is preferably welded such that the plurality of strands 213 are kept in a wire shape. For example, a configuration is preferred in which plating is formed on the surface of the plurality of strands 213, and during welding, primarily the surface plating melts while the strands 213 do not melt or largely do not melt, and the strands 213 are bonded to each other by the melted plating. For example, in a case where the melting point of the material forming the plating is low relative to the melting point of the material forming the strands 213, welding is carried out in conditions where primarily the plating can be melted. More specifically, when the strands 213 are formed of aluminum (melting point of approximately 660°) or copper (melting point of approximately 1085°) and the plating is tin plating (the melting point of tin being approximately 232°), the output, emission time, and the like of the laser beam is adjusted and welding is carried out in conditions where only the tin plating is melted.
However, even when plating is not provided on the strands 213, the embodiment may be configured so that a laser beam is fired and welding is performed such that primarily the surface of the strands close to the surface of the cutting target 214 are melted, and thus a form is achieved where the plurality of strands 213 are collected while preserving the wire shape.
In addition, within a scope that can preserve the shape of the cutting target 214 as much as possible, all or a portion (for example, the strands 213 close to the surface) of the plurality of strands 213 may also melt at first and break down the wire shape.
Accordingly, an extension direction portion of the core wire 212 (conductive member) in which the plurality of strands 213 are collected to create a wire shape more reliably maintains the shape that forms the cutting target 214a, and also each strand 213 becomes less likely to separate.
The step of bonding the plurality of strands 213 to each other can be executed by a method other than those noted above, as well. For example, when applying pressure to the core wire exposure portion 212a with the metal die 20, pressure may be applied with the metal die 20 heated, at least a portion of the strands 213 may be melted, and thereby the strands 213 may be bonded to each other. In particular, a configuration is preferred in which plating is formed on the surface of the strands 213, and during welding, primarily the surface plating melts while the strands 213 do not melt or largely do not melt, and the strands 213 are bonded to each other by the melted plating. Similar to the above, for example, in a case where the melting point of the material forming the plating is low relative to the melting point of the material forming the strands 213, pressure is favorably applied by the metal die 20 in conditions where primarily the plating can be melted.
As illustrated in
Also, as illustrated in
Effects similar to those of the first embodiment can also be achieved according to the second embodiment.
At the end portion of the electrical wire 210B, the plurality of strands 213 are in a pressed, collected form, and therefore each of the strands 213 is unlikely to separate after cutting. In particular, in the present embodiment, the plurality of strands 213 are in a bonded form, and therefore the plurality of strands 213 are even more unlikely to separate. Therefore, when the end portion of the electrical wire 210B is connected to another conductive member, the end portion of the electrical wire 210B can be readily connected to the other conductive member while inhibiting separation of the strands 213.
For example, a terminal-equipped electrical wire 310 illustrated in
The terminal 330 is a metallic plate member formed of copper, a copper alloy, or the like. A plating such as tin plating may also be formed on the surface of the terminal 330. A wire connection portion 332 is formed at one end portion of the terminal 330, and the other end portion is formed into a mating connection portion 334. The mating connection portion 334 can have a similar configuration to that of the mating connection portion 34 of the terminal 30 described in the first embodiment.
The wire connection portion 332 is a portion formed to be capable of crimping to the end portion 214B. More specifically, the wire connection portion 332 includes a bottom portion 332a and a pair of crimping tabs 332b that stand upright on two sides of the bottom portion 332a. In addition, in a state where the end portion 214B is arranged on the bottom portion 332a, by plastically deforming the pair of crimping tabs 332b inward, the wire connection portion 332 is crimped and connected to the end portion 214B in a state where the end portion 214B is surrounded by the bottom portion 332a and the pair of crimping tabs 332b (step (c)).
In the case of this example, the wire connection portion 332 is crimped to the end portion 214B where the plurality of strands 213 are compressed and collected as described above, and therefore the strands 213 are unlikely to separate and stick out from the connection portion.
Also, a terminal-equipped conductive member 410 illustrated in
The terminal 430 has a similar configuration to that of the terminal 30 described in the first embodiment, with the wire connection portion 32 formed at one end portion, and the other end portion formed into the mating connection portion 34.
In addition, the end portion 214B of the electrical wire 210B is connected to the wire connection portion 32. The connection between the end portion 214B and the wire connection portion 32 is created by welding such as laser welding, ultrasonic welding, or resistance welding, or by soldering or the like.
In the case of this example, the end portion 214B where the plurality of strands 213 are compressed and collected can be connected to the wire connection portion 32 by welding, soldering, or the like, and therefore they can be connected in a state inhibiting separation of the strands 213 and in a state where the end portion 214B is pressed against the wire connection portion 32 and is in contact that is as stable as possible.
Also, a connection structure 510 of the electrical wire 210B illustrated in
In the case of this example, the end portions 214B where the plurality of strands 213 are compressed and collected are brought opposite each other and can be connected by welding, soldering, or the like, and therefore they can be connected in a state inhibiting separation of the strands 213 and in a state where the end faces of the end portions 214B are in contact with each other that is as stable as possible.
Also, a connection structure 610 of the electrical wire 210B illustrated in
In the case of this example, the end portions 214B where the plurality of strands 213 are compressed and collected are stacked on each other and can be connected by welding, soldering, or the like, and therefore they can be connected in a state inhibiting separation of the strands 213 and in a state where the end portions 214B are in contact with each other that is as stable as possible.
In the present embodiment, the cutting targets 214 and 214a (the portion which, after cutting, becomes the end portions 214B) have a shape where the thickness dimension gradually decreases from both side edge portions toward the width-direction middle portion, and accordingly the two side edge portions are formed in a shape with the smallest thickness dimension, although this is not strictly necessary.
For example, when the plurality of strands 213 are compressed by the metal die 20, the strands 213 may enter between two lower edge portions of the projection 25 of the upper mold 24 and the two side surfaces of the lower mold surface 22 of the lower mold 21. Strands 213 that have entered between the two lower edge portions of the projection 25 of the upper mold 24 and the two side surfaces of the lower mold surface 22 of the lower mold 21 fill the gap between these elements, and therefore an excessively large force may be required when removing the upper mold 24 from the lower mold 21. In addition, strands 213 that have entered between the two lower edge portions of the projection 25 of the upper mold 24 and the two side surfaces of the lower mold surface 22 of the lower mold 21 may form a pointed portion that stands upright on the two side edge portions of the cutting target 214 and 214a, and therefore the pointed portions may damage other portions. In view of this, as illustrated in
In this case, a cutting target 214C has a shape where the projection 214P, which projects upward, is formed on the two side edge portions of the cutting target 214.
In a case where the cutting target 214C is cut by the high energy-density beam as described above, in the initial period of the displacement path of the laser beam 70, the laser beam 70 is fired at the projection 214P, as illustrated in
In this way, when the cutting target, in a cross-sectional view thereof, has a portion that is processed such that the thickness dimension gradually increases, so long as the high energy-density beam is fired across that portion in the direction in which the thickness dimension gradually increases, the effects noted above can be achieved. Therefore, there is no need for the portion that is processed such that the thickness dimension gradually increases to start from either of the edge portions of the cutting target.
A method of manufacturing a conductive member, a long conductive member, and a conductive member according to a third embodiment are described. In the description of the present embodiment, configuration elements that are similar to those described in the first or second embodiment are assigned the same reference numerals and the explanation thereof is omitted, and the description primarily focuses on differences from the first or second embodiment.
First, a manufacturing method of a conductive member is described.
As illustrated in
In the present embodiment, the long conductive member 710 is a braided wire in which a plurality of strands 713 are braided in a tubular form. The plurality of strands may also be braided in a sheet form. Similar to the second embodiment, the strands 713 are formed of a metal wire such as aluminum, an aluminum alloy, copper, or a copper alloy, and plating such as tin plating may be formed on the surface of each of the strands 713.
As illustrated in
Step (a) in which the cutting target 714 is formed as described above preferably includes a step where the plurality of strands 713 are bonded to each other. In the present embodiment, the cutting target 714 undergoes non-pressure welding to form a cutting target 714a.
In this example, a similar method to that described in the second embodiment can be employed for the non-pressure welding. Here, as illustrated in
The cutting target 714a formed in this way is formed in a shape having a shaped portion where, in a cross-sectional view orthogonal to the extension direction of the cutting target 714a, similar to the cutting target 214a of the second embodiment (see
Also, as illustrated in
When this happens, as illustrated in
A terminal is connected to the end portion 714B of the conductive member 710B by crimping, welding, soldering, or the like, similar to the second embodiment, or the other conductive member 710B, the electrical wire 210B, or the like is brought opposite or stacked on the end portion 714B of the conductive member 710B and is connected by welding or the like.
Effects similar to those of the first and second embodiments can also be achieved according to the third embodiment.
{Modifications}
As in the modification illustrated in
In the example illustrated in
Thermal cutting marks 814Bt of the laser beam 70 forming striated unevenness, as illustrated in
In this case also, the dimensions L1 and L2 of the cutting target 814 in the firing direction of the laser beam 70 gradually increase at, at least, a portion where the laser beam 70 moves (in this example, at the initial period). Therefore, similar to each of the above embodiments, even at the initial period of the displacement path of the laser beam 70, the side edge portion on one side of the cutting target 814 can easily be completely cut even without increasing the output of the laser beam 70 or slowing the displacement speed. In addition, from a midway point onward in the displacement path of the laser beam 70, heat imparted to the displacement path of the laser beam 70 up to that point builds up cumulatively, and therefore a portion of the cutting target 814 where the thickness dimension is comparatively large (at or after a point in time where the laser beam 70 has reached the upper long side) can easily be completely cut. As a result, the long conductive member 810 can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible. Accordingly, a low-output laser processing device can also be used, and a high-output laser processing device can be used at a low output and its lifespan can be extended.
In addition, midway along or at a terminal end of the displacement path, the cumulative heat up to that point accumulates in the cutting target 814, and therefore even when the laser beam moves more quickly than in the initial period of cutting, the energy density applied to the cut portion can be equivalent to the initial period of the displacement path. Therefore, by moving the laser beam more quickly midway along or at a terminal end of the displacement path than in the initial period of cutting up to that point, cutting can also be accomplished in a shorter amount of time as compared to cutting at a fixed displacement speed.
As can be understood from each of the above embodiments, the modifications, and the like, according to a method of manufacturing a conductive member that includes (a) a step of preparing a long conductive member provided with a cutting target in an extension direction portion, and (b) a step of firing a high energy-density beam at the cutting target while moving the high energy-density beam in a direction that intersects with the extension direction of the long conductive member, and also cutting the cutting target at, at least, a portion where the high energy-density beam moves, such that a dimension of the cutting target in the firing direction of the high energy-density beam gradually increases, a long conductive member can be more completely cut in as short a time as possible by a high energy-density beam with as low an output as possible. In this case, preferably, the gradual increase in the dimension of the cutting target in the firing direction of the high energy-density beam is in the first half of the displacement path over which the cutting of the cutting target is performed, and more preferably is in the initial period of movement.
When observing an end face of the conductive member after cutting in this case, striated thermal cutting marks made by the high energy-density beam are formed, and moreover, the end face is formed in a shape having a portion where the dimension along the extension direction of the thermal cutting marks gradually increases in a direction orthogonal to the extension direction of the thermal cutting marks.
Each configuration described in each of the above embodiments and each of the modifications can be combined as appropriate so long as they do not contradict each other. For example, in the third embodiment, a projection similar to the projection 214P described in the second embodiment may also be formed on the two side portions of the cutting target. Also, in the modification illustrated in
In the above, the present invention is described in detail. However, the above description is, in all aspects, for exemplary purposes and the present invention is not limited thereto. Numerous modifications not given as examples are understood to be conceivable without departing from the scope of the present invention.
10, 110, 710, 810 Long conductive member
10B, 710B, 810B Conductive member
10C, 310, 410 Terminal-equipped conductive member
14, 214, 214a, 214C, 714, 714a, 814a Cutting target
14B, 214B, 714B, 814B End portion
14Bt, 214Bt, 714Bt, 814Bt Thermal cutting mark
30, 330, 430 Terminal
32, 332 Wire connection portion
70 Laser beam
210, 210B Electrical wire
212, 212B Core wire
212
a Core wire exposure portion
213, 713 Strand
510, 610 Connection structure
| Number | Date | Country | Kind |
|---|---|---|---|
| 2016-245342 | Dec 2016 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/042782 | 11/29/2017 | WO | 00 |
