JPWO2005082567A1 - Insulated coated wire joining method and apparatus - Google Patents

Abstract

After the end portions (1a, 1b) of the plurality of covered wires are constrained or pressed and brought into close contact, friction stir welding is performed from the end portions. The coating is dispersed in the stirring section, and the coated wires can be joined without peeling.

Description

      The present invention relates to a bonding method and a bonding apparatus for insulating coated wires for bonding a plurality of metal wires having an insulating coating, or a plate material thereof with high quality and high efficiency without peeling the insulating coating.

Conventionally, various methods have been proposed for joining a plurality of metal wires having an insulating coating. For example, after the insulating film is chemically and mechanically peeled off, soldering or melting with a laser, TIG or the like is employed. In addition, a method of heating, carbonizing and removing the insulation-coated wire using a resistance welding machine is employed. As one method of joining without peeling, a method using friction stirring is proposed. One of the advantages of the coated metal wire by friction stir welding is that a bond free of defects such as blow holes can be obtained regardless of the type of metal wire. In the case of copper-based insulation-coated wires, copper wires with a high oxygen content will generate many blow holes when a laser, TIG, or other fusion bonding method is used, and reliable bonding cannot be obtained. There is. Further, when the coated metal wire is melt-bonded without peeling, since the coating is an organic substance and contains oxygen and hydrogen, a large number of huge blow holes are generated and cannot be put to practical use. Friction stir welding is a joining using plastic flow, and it is possible to reduce material defects such as blow holes. As a method for joining coated wires using friction stirring, there is the following technique. Japanese Patent Application Laid-Open No. 2003-71576 discloses a method in which a terminal is formed by inserting a covering material into a fixing material and friction stir welding the coated wire from the side surface direction. Japanese Patent Application Laid-Open No. 2003-126972 discloses a method in which a plurality of metal wires are integrated with an adhesive and then friction stir welding is performed. These characteristics lie in that metal wires having an insulating coating having a particularly high heat resistance can be joined without stripping the insulating coating. Moreover, in order to carry out the fixation and restraint for the friction stir welding with certainty, it is characterized by joining from the side surface of the metal wire.
JP2003-71576 JP 2003-126972 A

In joining from the side, it was necessary to align the distance between the coated metal wire and the friction stir welding tool so as to keep them relatively constant. When inserting and fixing to a fixing material, alignment is easy but insertion is often difficult, and when fixing with an adhesive, there is a problem that it is difficult to control the shape after fixing. Further, in order to join the aligned metal wires from the side surfaces, it is necessary to move the tool in a direction perpendicular to the metal wires. Further, in the joining from the side direction, there is a drawback that the ratio of the insulating coating amount dispersed in the joining portion is increased, and the resistance of the joining portion is increased.
In order to stably bond a plurality of coated metal wires without peeling, the metal wires are brought into close contact with each other, the metal wires are fixed and restrained from the side surfaces of the metal wires, and a tool is inserted from the end surface to perform friction stir welding.
Friction stir welding is a method in which a joining material is agitated and joined by the rotating action of a rotary tool comprising a pin portion and a shoulder portion thicker than the pin portion. The pin portion stirs the material, and the shoulder acts to confine the stir material in the tool without overflowing the tool. When a plurality of members are subjected to friction stir welding, if the gap between the members is large, a nest-like defect occurs in the joint. For this reason, raising the adhesiveness is a requirement for obtaining a highly reliable bond. Also, in friction stir welding, when the rotating pin portion is inserted into the joining material and agitated, the agitated metal is not pushed out of the tool, so the rotating tool must be pressed against the joining material with a strong force. .
Joining multiple coated metal wires from the end face is secured with a strong force from the side using a jig, reducing the gap between the metal wires and receiving the pressing force of the rotating tool with the side restraining jig. This is achieved by joining. If the pressing force to the metal wire from the side surface is increased and pressure forming is performed, a preferable close contact with no gap can be obtained. Moreover, after crimping | molding, cutting process is given and a more reliable joining can be obtained by making the cross section with the best adhesiveness into an edge part. Further, when pressure forming is applied from the end face during pressure forming and the forming process is performed so as to increase the cross-sectional area of the end face of the metal wire, the reliability is further greatly improved.
In the forming process, it is preferable to form the coated metal wire so as to adhere closely without a gap. For example, if the end portions are compression-molded to form a plurality of coated metal wires into a substantially circular, elliptical, or polygonal shape, and then subjected to frictional stirring, highly reliable joining can be obtained. In addition, if the end part is formed in a substantially nail shape by adding compression molding from the end side in order to increase the friction stir area, the friction stir area can be increased, the joint strength is improved, and the reliability is improved. It becomes possible to improve the property. This molding process does not have to be performed once, and a plurality of molding processes may be set in order to form a shape suitable for friction stirring. In addition, in order to form a shape suitable for friction stirring, a more reliable joining can be obtained by applying a cutting step after the pressure molding and setting the cross section with the best adhesion as the friction stirring surface at the end.
As mentioned above, if the side of the metal wire is constrained or shaped with a jig and the end faces are friction stir welded, a highly reliable bond can be obtained, but a fixing material is placed around the side of the metal wire. It is also possible to join. After inserting a plurality of metal wires into the ring-shaped fixed metal material, the gap may be eliminated by caulking or the like, or a plurality of metal wires may be wound and caulked with a plate-like metal plate. When a ring or plate-shaped fixing material is installed and the end faces of metal wires are friction stir welded, a jig is installed on the opposite end face where the rotating tool of the fixing material is inserted and the pressing force of the rotating tool is reduced. You can take it. About a ring-shaped and plate-shaped fixing material, it is necessary to be the same material as a metal wire. In particular, it is preferable not to select a material having a melting point extremely higher than the melting point of the metal wire.
In the friction stir welding of the present invention, it is possible to join only by moving the metal wire in the end face direction without optimizing the rotating tool in the direction of the adjacent metal wire by optimizing the shoulder diameter and pin diameter of the rotary tool. It becomes. Depending on how the metal wire is restrained by a jig or the like, movement in the direction of the adjacent metal wire may be required, but the movement distance can be minimized. For this reason, in the apparatus which implements friction stir welding of the present invention, the structure can be simplified. The joining apparatus is composed of a restraining device that restrains forming and constraining a plurality of metal wires from a side surface by one process or multiple processes, a drive unit that imparts rotation and relative movement in the end surface direction of the metal wire to a rotating tool, and a control unit. However, the drive unit may have a function of moving in the direction of the adjacent metal line.
When the coated metal wires are joined to each other by friction stir welding, the coating is mechanically broken, dispersed in the stirring portion, and thermally decomposed, so that the metal wires can be joined. There are many kinds of materials for coating the coated metal wire, and each has different heat resistance. The coating with the best heat resistance is a polyimide coating. The bonding method of the present invention can be bonded without peeling regardless of the type of coating, but is particularly suitable for bonding copper-coated wires with high heat resistance. Since the covering wire is generally joined to obtain electrical conduction, it is preferable that the amount of the coating dispersed in the joint is small. The joint of the present invention is obtained by joining the end faces having no coating to minimize the coating to be dispersed. In particular, it is suitable as a joint when the electrical conductivity of the joint is required to be small.

FIG. 1 is a perspective view showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the process of the embodiment of the present invention and a perspective view of the appearance after joining.
FIG. 3 is a sectional view showing a process of the embodiment of the present invention and a perspective view of an appearance in each process.
FIG. 4 is a cross-sectional view showing a process of an embodiment of the present invention and a perspective view of an appearance in each process.
FIG. 5 is a sectional view showing a process of an embodiment of the present invention and a perspective view of an appearance in each process.
FIG. 6 is a cross-sectional view showing the process of the embodiment of the present invention and an external view of the joint portion. FIG. 7 is a cross-sectional view showing the process of the embodiment of the present invention and the external view of the joint portion. The drawings are an external view and a cross-sectional view of an automotive alternator to which the joining method of the present invention is applied.

Embodiments of the present invention will be described below.
FIG. 1 is a view showing an embodiment in which a plurality of coated metal wires are joined together by friction stir welding. Two 1.6 mm polyamide enamel coated wires (AIW wires) (1a, 1b) are clamped with a pair of restraining jigs 5a, 5b, and the contact portions of the two AIW wires are friction stir welded with the rotary tool 4. . The rotary tool 4 includes a pin portion 2 and a shoulder portion 3 having a larger diameter than the pin portion. The rotary tool 4 is connected to a rotary drive motor through a rotary shaft. The diameter of the pin part was 0.8 mm, the length was 1.2 mm, and the diameter of the shoulder part was 1.6 mm. The rotary tool 4 was rotated at 10,000 rpm, and moved from the end of the AIW line until the shoulder 3 reached the end of the AIW line. After the movement was completed, 1 s frictional stirring was performed to complete the joining.
FIG. 2 is a sectional view showing the above process and a perspective view of the appearance after joining. The enamel coating is carbonized and crushed by friction stirring and dispersed in the joint 6. It was confirmed that the resistance of the joint 6 was almost the same as that of copper of the enameled wire core. The core wire copper is tough pitch copper. After bonding, the cross section of the bonded portion was cut and polished and observed. No defects such as blowholes were observed, and a good joint was obtained.
The shape of the restraining jig was 7a and 7b shown in FIG. 3, and two AIW lines (1a and 1b) were friction stir welded. FIG. 3 shows the shape of the restraining jig viewed from the end face direction of the AIW line and the state of the AIW line. The end portions of the AIW line are plastically deformed into a substantially hexagonal shape by the forming jigs 7a and 7b, and the joint portions are brought into close contact in advance. As a result, the area of the close contact portion can be increased, and the region in which frictional stirring can be performed substantially can be increased. Here, the two AIW lines are of φ1.6 as in the first embodiment. As the forming jigs 7a and 7b, those having a shape in which the length of the contact portion is about 2.2 mm were used. The pin diameter of the rotary tool used for friction stirring is 1 mm, the pin length is 1.5 mm, and the shoulder diameter is 2 mm. Friction stirring was carried out at a rotation speed of the tool of 8000 rpm to obtain a joint 9. As a result of observing by cutting, polishing and observing the cross section of the joint 9 after friction stirring, it was confirmed that a good joint having no defect was obtained.
Two polyamide enamel-coated wires (AIW wires) of φ1.6 (1a, 1b) were friction stir welded. FIG. 4 shows the joining process and changes in the appearance of the AIW line. First, the side portions of the two AIW lines 1a and 1b were compression-molded, and then the end portions were cut so that the closest contact portions became end surfaces. A compression mold (10a, 10b) in which the length of the contact portion was about 2.2 mm was used. After retracting the cutting jig 11, the rotary tool 12 was inserted into the end of the AIW line to perform friction stir welding. The shape of the tool is the same as in the second embodiment. The rotational speed was also the same as in Example 2. A good joint 13 was obtained.
Two polyamide enamel-coated wires (AIW wires) of φ1.6 (1a, 1b) were friction stir welded. FIG. 5 shows the joining process and changes in the appearance of the AIW line. First, the side portions of the two AIW lines were compression molded using the molding jigs 14a and 14b, and then the end portions were molded using the molding jig 15 so that the cross-sectional area was large. The cross section of the end portion after molding was made to be an ellipse of about 2.2 mm × 3 mm. After the forming jig 15 was retracted, the rotary tool 16 was inserted into the end of the AIW line to perform friction stir welding. The shape of the tool is the same as in the second embodiment. The rotational speed was also the same as in Example 2. A good joint 17 was obtained.
Eight polyamide enamel-coated wires (AIW wires) 1 of φ1.6 were joined by friction stirring. FIG. 6 shows the joining process. Eight AIW wires were inserted into the copper ring 18. The ring 18 has a wall thickness of 1 mm and an inner diameter of 6 mm. Thereafter, the ring 18 was pressure-formed by the forming jigs 22a and 22b to form a substantially oval shape having a major axis of about 6 mm and a minor axis of about 3 mm. The rotary tool 20 was inserted into the end of the ring 18 and frictionally stirred. The pin diameter and length of the rotary tool are 1.3 mm and 2 mm, respectively, and the shoulder diameter is 2.6 mm. The rotation speed was 6000 rpm. Since the end portion is substantially elliptical, the friction stir was performed twice to complete the joining of the AIW lines 1a, 1b and the ring 18. As a result of observing the cross sections of the joint portions 21a and 21b, it was confirmed that the ring and the eight AIW lines were integrated. It was confirmed that the conduction between the AIW lines and the ring was also good.
In Example 4, after rotating and inserting the rotary tool 20 during friction stirring, the rotary tool 20 was moved in the major axis direction of the elliptical shape. The moving speed is 10 mm / sec and the moving distance is 6 mm. A substantially elliptical bonded appearance was obtained. The joined state and conductive state were the same as in Example 4.
The jig shape at the time of pressure forming the ring of Example 4 was changed to the shape (22a, 22b) shown in FIG. The shape of the forming jig is corrugated so that the AIW lines after pressure forming are more closely adhered to each other and the shape of each AIW line after forming is substantially uniform. Adhesion was improved by equalizing the force. When the ends press-molded into the shape shown in FIG. 7 were friction-stirred, good joints 23a and 23b were obtained.
FIG. 8 shows an example in which the friction stir welding of the present invention is applied to the stator core 27 of the vehicle alternator 24. The stator core 27 is composed of a coil 25 formed of an AIW wire on an iron core 26 in which slots are formed. In order to increase the output efficiency of the generator, it is preferable to reduce the gap in the slot of the AIW line inserted in the slot of the core as much as possible. For this reason, in this embodiment, the rectangular wire 28 is used as the AIW line. The material of the AIW core wire is tough pitch copper. The core 26 has 90 slots. When a normal AIW round wire is used, the coil 25 can be formed by winding. However, since winding is difficult with a flat wire, a bent flat wire is inserted into the slot and another slot is inserted. It is necessary to form a coil by joining to the end portion of the flat wire inserted into. Two pairs of rectangular wires were inserted into each slot, and joined to the rectangular wires inserted into the other slots. The flat wire has a cross-sectional shape of 1.6 × 2 mm. After inserting and aligning the flat wire, the end part to be joined was pressure-molded into a shape of about 1.8 mm square. Each joint was friction stir welded. The rotary tool has a pin diameter of 0.9 mm, a pin length of 1.4 mm, and a shoulder diameter of 1.8 mm. A rotating tool was inserted into the end at a rotational speed of 8000 rpm, and friction stir welding was performed. There are 180 joints. Thereafter, seven AIW wires were joined by friction stirring at the other end of the coil. In this case, the AIW wire was inserted into a quadrangular ring (inner circumference side size 4 mm × 7 mm, plate thickness 1 mm, copper) and caulked, and the gap between the ring and the AIW wire was eliminated, followed by friction stirring. The rotating tool had a pin diameter of 2.5 mm, a pin length of 3.8 mm, and a shoulder diameter of 5 mm, and was friction-stirred at 5000 rpm. A vehicle AC generator was manufactured using the stator core thus manufactured. Friction stir welding was also used to join the stator core output wire to the terminal. The output line was caulked at the terminal, and after pressure forming, the terminal and the end of the output line were joined by friction stir welding. It was confirmed that a predetermined output was obtained.
Friction stir welding was used to manufacture coils in the stator core of a hybrid electric vehicle motor. The coil was made of AIW wire having φ0.8 tough pitch copper as the core wire, and after winding on the core, the output wires were joined to each other at six locations. The number of junctions at each junction is six. Six AIW wires were inserted into a ring having an inner diameter of 2.5 mm and an outer diameter of 4.5 mm, and pressure-molded so that the outer peripheral shape was about 3.5 mm × 4 mm. The ends of the AIW wire were friction stir welded using a rotating tool having a pin diameter of 1.5 mm, a pin length of 2.3 mm, and a shoulder diameter of 3 mm. The rotation speed of the rotating tool at the time of joining is 6000 rpm. Moreover, the neutral wire was joined by the same method. The number of bonded AIW lines is 21. An AIW wire was inserted into a copper ring having an inner diameter of 5 mm and an outer diameter of 7 mm and subjected to pressure molding, so that the outer peripheral shape was about 4.5 mm × 6 mm. The pressure-molded ring and the end of the AIW line were friction stir welded using a rotating tool having a bin diameter of 2.3 mm, a pin length of 3.5 mm, and a shoulder diameter of 4.6 mm. The rotation speed of the tool was 4000 rpm, and the tool was moved at 5 mm / sec in the longitudinal direction of the ring and joined. When a motor was manufactured using the coil thus manufactured, the intended output was obtained.

      As described above, when the insulated coated wires are joined using the friction stir welding of the present invention, the coated wires can be joined to each other without peeling off the insulated coating. In particular, when a copper material having a high oxygen content is used for the core wire, a highly reliable joint can be obtained.

Claims (6)

In a joining method for joining a plurality of metal wires having an insulating coating, after the metal wires are brought into close contact with each other, the end face of the metal wire has a pin portion and a rotating action of a rotating tool comprising a shoulder portion thicker than the pin portion and the metal wire. A method of joining insulation-coated wires, characterized by performing friction stir welding by relative movement of the wire. In a joining method for joining a plurality of metal wires having an insulating coating, the metal wires are bundled together, the end portions are pressed and integrated, and then the end surfaces of the metal wires are composed of a pin portion and a shoulder portion thicker than the pin portion. A method for joining insulating coated wires, characterized in that friction stir welding is performed by a rotating action of a rotating tool and relative movement of a metal wire. In a joining method for joining a plurality of metal wires having an insulating coating, the metal wires are bundled together, and the end portions are pressed and integrated so as to increase the end cross-sectional area, and then the end surfaces of the metal wires are connected to the pin portions. A method for joining an insulation-coated wire, characterized in that friction stir welding is performed by a rotating action of a rotary tool including a shoulder portion thicker than the pin portion and relative movement of a metal wire. In Claims 1 to 3, a fixing material that is electrically conductive and has a melting point substantially equal to that of the metal wire is disposed around the end portion of the metal wire in order to bring the coated metal wires into close contact with each other. Insulation coating material joining method. A restraining device that presses and restrains ends of a plurality of metal wires having an insulating coating and adheres in a substantially circular shape, a device that holds a rotating tool composed of a pin portion and a shoulder portion that is thicker than the pin portion, and a rotating tool comprising: A friction stir welding apparatus comprising a device that moves relative to the end face direction of the metal wire. 6. A friction stir welding apparatus according to claim 5, wherein a pressure forming device is added to the end restraining device.

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