JP2014100019A - Terminal structure of electric wire and connection method between electric wire and terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terminal structure of an electric wire in which an electric wire formed by firmly bundling a plurality of metallic thin wires is connected to a terminal by using resistance-welding even if the electric wire has an insulating film, and to provide a connection method between the electric wire and the terminal.SOLUTION: A connection part 5 of an electric wire 4 formed by bundling a plurality of metallic thin wires is covered with a band material 6 made of metal having the same material as that of the thin wires, the band material 6 and the electric wire 4 in the band material 6 are softened by heat treatment while pressurizing this band material 6, a terminal board 3 is put in a state capable of conducting to the band material 6 by partially destructing insulating films of these thin wires, and the band material 6 is welded by resistance-welding to the terminal board 3 made of the same kind of metal or the different kinds of metal in the state capable of conducting to the terminal board 3.

Description

  The present invention relates to a terminal structure of an electric wire for connecting an electric wire obtained by bundling a plurality of fine metal wires to a terminal, and a method for connecting the electric wire and the terminal.

  Conventionally, copper, copper alloys, and the like are often used as electric wires. On the other hand, aluminum has good electrical conductivity and is lighter and cheaper than copper or the like. Therefore, there are many advantages if aluminum or an aluminum alloy can be used for the electric wire.

  As a method of connecting an electric wire in which a plurality of aluminum thin wires are bundled to a terminal, generally an aluminum electric wire is often soldered to the terminal for connection. In this case, since there is a strong insulating oxide film (aluminum oxide) on the aluminum surface, when the wire is heated in this soldering, the surface of the wire is activated with flux to prevent the formation of an oxide film. It is known that soldering is performed (for example, Patent Document 1).

  By the way, conventionally, resistance welding is known in which a metal material is sandwiched between a pair of electrodes, a large current is applied for a short time while applying pressure, a resistance heat generation of the metal is used, a nugget (alloy layer) is generated and fusion-bonded. Yes. In this method, welding can be efficiently performed in a short time, and welding with a good finished appearance can be achieved, and solder and flux can be dispensed with.

JP 2010-182566 A

  However, as described above, since there is an insulating oxide film on the surface of the aluminum wire, resistance welding without using solder or flux does not connect the aluminum wire and the terminal between the electrodes. In some cases, it was difficult to achieve terminal connection of aluminum wires using resistance welding. Further, when an aluminum wire is directly pressurized, the strength is lower than that of copper, and thus the wire may be broken by the pressure.

  The present invention relates to a terminal structure of an electric wire for connecting an electric wire in which a plurality of thin metal wires are tightly bundled to a terminal using resistance welding, and even an electric wire having an insulating film, and the connection between the electric wire and the terminal It aims to provide a method.

  In order to achieve the above object, in the terminal structure of an electric wire according to one configuration of the present invention, the connecting portion of the electric wire in which a plurality of fine metal wires are bundled is covered with a strip made of the same kind of metal as the fine wires. The band material and the electric wires in the band material are softened by heat treatment while pressurizing the band material, and these insulating films are partially broken, so that the band material can be conducted. The strip is welded to a terminal plate made of the same or different metal as the metal by resistance welding in the conductive state.

  According to this configuration, since the insulating coating of the strip and the electric wire in the strip is softened by heat treatment while being pressed, the strip is partially broken and welded by resistance welding in a conductive state. It is possible to realize a terminal structure of an electric wire by resistance welding, which has been impossible in the past. Moreover, since an electric wire is pressurized via a strip | belt material, a bend of an electric wire can be prevented. Thereby, even if it is an electric wire with an insulating membrane | film | coat, an electric wire and a terminal can be efficiently welded in a short time by resistance welding, and the finished external appearance can be welded well.

  Preferably, the thin wire and the strip are made of aluminum. The terminal board is made of aluminum or copper. Therefore, even if it is a dissimilar metal, the electric wire and the terminal can be firmly welded.

  In the method of connecting a terminal and an electric wire according to another configuration of the present invention, a connecting portion of an electric wire in which a plurality of fine metal wires are bundled is covered with a belt made of the same kind of metal as the thin wire, A heat treatment step for softening the strip and the electric wire in the strip for a long period of time while applying pressure, and electrically breaking the insulating coating by partially destroying these insulating films; and A welding process in which the strip is resistance-welded to the terminal plate made of the same kind or different metal as the metal in a conductive state by energizing with higher power in a shorter time than the heat treatment process. .

  According to this configuration, the heat treatment process pressurizes the band material and softens the insulation film of the band material and the electric wire in the band material by heat treatment so that it is partially broken to be in a conductive state. In this conductive state, welding is performed by resistance welding, so that it is possible to realize a method of connecting a terminal and an electric wire by resistance welding, which has been impossible in the past. Moreover, since an electric wire is pressurized via a strip | belt material, a bend of an electric wire can be prevented. Thereby, even if it is an electric wire with an insulating membrane | film | coat, an electric wire and a terminal can be efficiently welded in a short time by resistance welding, and the finished external appearance can be welded well.

  According to the present invention, even an electric wire with an insulating film can be efficiently welded to the electric wire and the terminal in a short time by resistance welding, and the finished appearance can be well and firmly welded.

(A) is a developed view showing a terminal structure of an electric wire according to an embodiment of the present invention, (B) is a perspective view showing a state before connection of the electric wire and the terminal, and (C) shows a terminal structure of the completed electric wire. It is a perspective view. It is a schematic diagram which shows the resistance welding apparatus for implement | achieving the terminal structure of an electric wire. (A), (B) is a perspective view explaining the terminal structure of an electric wire. (A)-(C) are side views which show the connection method of the terminal and electric wire concerning other embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1A is a development view showing a terminal structure of an electric wire according to an embodiment of the present invention, FIG. 1B is a perspective view showing a state before the connection between the electric wire and the terminal, and FIG. 1C is a terminal structure of the completed electric wire. FIG. As shown in FIG. 1A, the electric wire connecting terminal 1 is made of the same kind of metal as the electric wire 4, and has a connector portion 2 and a terminal plate 3. As shown in FIG. 1B, the connection portion 5 of the electric wire 4 is connected to the terminal plate 3 of the terminal 1. The connection part 5 between the connector part 2 and the electric wire 4 is arranged along a direction that matches the longitudinal direction of the electric wire 4.

  As shown in FIG. 1A, the electric wire 4 is formed by bundling a plurality of thin metal wires, for example, aluminum thin (outside diameter of about 1 to 3 mm) round wires. It can also be applied to a round wire with an outer diameter of up to about 30 mm. The terminal 1 is made of a single plate of the same type of aluminum, and the connecting portion 5 of the electric wire 4 is also covered with, for example, a cylindrical band material (hereinafter referred to as a pipe) 6 made of the same type of aluminum. ing. In this example, aluminum is used as the metal material, but an aluminum alloy or an aluminum-based composite material may be used.

  FIG. 2 shows a schematic diagram of a resistance welding apparatus used in this embodiment. This known apparatus includes a pair of resistance welding electrodes 10 and 11 that are movable in the vertical direction, a welding power source 12, and an energization control unit 13 that energizes the electrodes 10 and 11, respectively. The aluminum wire 4 and the terminal 1 are sandwiched therebetween, and resistance welding is performed by flowing a welding current from the welding power source 12 under the control of the energization control unit 13. In resistance welding, a welding current is usually applied between electrodes 10 and 11 with a large current of several tens of amperes to several tens of thousands of amperes and flowing for a short time of several milliseconds to several hundreds of milliseconds. In this case, the voltage is a few volts. A nugget (alloy layer) is generated using resistance heat generation of aluminum, and the aluminum wire 4 and the terminal 1 are melt-connected.

  First, using this resistance welding apparatus, with the pipe 6 in FIG. 1B being pressurized, the pipe 6 and the electric wire 4 in the pipe 6 are heated by heat treatment by energizing with low power for a long time. Softened. Here, the long time means a time that is several hundred times longer than the normal resistance welding time for the aluminum material. In addition, low power means power lower than that of normal resistance welding for aluminum materials, and consists of a high current of several thousand amperes lower than a normal high current and a voltage slightly lower than the normal voltage. Refers to electric power. By this pressurization and softening, the aluminum pipe 6 and the electric wire 4 in the pipe 6 are deformed and the oxide film is partially broken, so that the aluminum pipe 6 and the electric wire 4 are made conductive. As shown in FIG. 1C, the pipe 6 and the aluminum electric wire 4 are deformed in a state of being crushed in a substantially U shape by pressurization and softening.

  As shown in FIG. 3A, the resistance welding apparatus has a normal shape in which, for example, the upper electrode 10 has a flat contact surface, and the tip 11a of the lower electrode 11 makes the pipe 6 substantially U-shaped. It has a shape for crushing, and the length L1 of the distal end portion 11a is slightly shorter than the length L in the longitudinal direction of the pipe 6 (L1 <L). As shown in FIG. 3B, the pipe 6 (and the electric wire 4 in the pipe 6) is crushed by the tip portion 11a of the electrode 11, and a longitudinal section is obtained by the crushed bottom surface 7 and the rising side surfaces 8 and 8. Is formed in a substantially U-shape.

  It is considered that the heating by this heat treatment caused the aluminum recrystallization temperature to exceed 150 to 200 ° C., and the aluminum wire 4 and the pipe 6 were softened by recrystallization. The aluminum electric wire 4 and the pipe 6 are deformed in combination with the pressurization by the electrodes 10 and 11 because a large tensile force is applied to these oxide films due to the expansion accompanying the softening. It is assumed that it has been destroyed and becomes conductive.

  Further, in this heat treatment and resistance welding described later, since the aluminum electric wire 4 in FIG. 1B is pressurized through the pipe 6, the electric wire 4 in the pipe 6 is not directly pressurized. Can be hard to break. Moreover, since the electric wire 4 consists of many thin wires, since it is easy to disperse | distribute, since the state gathered in the pipe is hold | maintained, handling becomes easy. Furthermore, since the pipe 6 is interposed between the electric wire 4 and the electrodes 10 and 11, it is possible to prevent the aluminum electric wire 4 from adhering to the electrodes 10 and 11.

  The pipe 6 is resistance-welded to the aluminum terminal plate 3 by energization with high power in a shorter time than the heat treatment in a state where the aluminum electric wire 4 and the pipe 6 can conduct. Here, the short time means a normal resistance welding time for the aluminum material. Moreover, high power means the electric power of the normal resistance welding about aluminum material, and means the electric power which consists of a normal large current and a normal voltage.

  By the resistance welding, a nugget (alloy layer) is formed between the round wires of the electric wire 4, and the connection portion 5 of the electric wire 4 is firmly welded to the terminal plate 3 of the terminal 1 through the pipe 6.

  Thus, in this embodiment, while pressurizing the pipe (band material), the insulating film of the pipe and the electric wire in the pipe is softened by heat treatment, partially broken, and in a conductive state, by resistance welding. Since welding is performed, it is possible to realize a terminal structure of an electric wire by resistance welding, which has been impossible in the past. In addition, since the electric wire is pressurized through the pipe, the electric wire can be prevented from being broken. Thereby, even if it is an electric wire with an insulating membrane | film | coat, an electric wire and a terminal can be efficiently welded in a short time by resistance welding, and the finished external appearance can be welded well.

  In this example, the aluminum electric wire 4 uses a bundle of many round wires, but instead of this, a bundle of square wires, a bundle of stranded wires, a bundle of aluminum foil coated wires, and the like are used. May be. In the case of a bundle of square wires, the pipe 6 may be formed in a substantially rectangular tube shape.

  Moreover, although the pipe 6 is used as a strip | belt material, you may use what wound the board | plate material around the electric wire.

  4A to 4C are side views showing a method for connecting a terminal and an electric wire according to another embodiment. First, as shown in FIG. 4A, the pipe 6 and the terminal 1 covering the electric wire 4 are sandwiched and held between both electrodes 10 and 11 of the resistance welding apparatus.

  Next, as shown in FIG. 4B, in the heat treatment step, the pipe 6 is pressurized with, for example, 1000 N by the electrodes 10 and 11, and in this pressurized state, the pipe 6 and the electric wire 4 in the pipe 6 are, for example, 3 It is softened by heating by energizing low power consisting of a low current such as 5000 A and a low voltage such as 3 to 4 V for a long time of ˜4 sec, and becomes a conductive state.

  The time interval between this heat treatment step and the next welding step is preferably a short time such as 10 to 20 msec. That is, the aluminum electric wire 4 and the pipe 6 are maintained in a heated state, are hardly cooled, and are resistance-welded.

  Finally, as shown in FIG. 4 (C), in the welding process, the pipe 6 is pressurized with, for example, 1000 N by the electrodes 10 and 11 in a state where the pipe 6 and the electric wire 4 in the pipe 6 can be conducted. In the state, the pipe 6 and the electric wire 4 in the pipe 6 are resistance-welded in a short time of, for example, 10 to 30 msec by energizing with a high current such as 14,000 to 15000A and a high voltage such as 37V. . Thereby, a nugget is formed between each round wire of the electric wire 4, and the connecting portion 5 of the electric wire 4 is firmly welded to the terminal plate 3 of the terminal 1 through the pipe 6.

  Thus, in this embodiment, using a resistance welding apparatus, the insulating film of the pipe and the electric wire in the pipe is softened by heat treatment and partially broken by pressurizing the pipe (strip material) by a heat treatment process. In this state, since welding is performed by resistance welding in this conductive state in the welding process, it is possible to realize a method of connecting a terminal and an electric wire by resistance welding, which could not be realized in the past. In addition, since the electric wire is pressurized through the pipe, the electric wire can be prevented from being broken. Thereby, even if it is an electric wire with an insulating membrane | film | coat, an electric wire and a terminal can be efficiently welded in a short time by resistance welding, and the finished external appearance can be welded well.

  In the embodiment described above, the heat treatment is performed using the resistance welding electrodes 10 and 11 of the resistance welding apparatus. However, an equivalent heat treatment may be performed using another apparatus.

  In the above embodiment, the electric wire 4 is made of aluminum, an aluminum alloy, or an aluminum-based composite material, and the terminal plate 3 is also made of the same kind of material. However, the terminal plate 3 may be made of different types of copper, copper alloy, or copper-based composite material. Good. In this case, the electric wire 4 and the terminal 3 may be electrically contacted and the wire may be corroded. However, for example, by tin-plating the copper terminal plate 3, the contact can be prevented. Moreover, it is good also considering the electric wire 4 as copper, a copper alloy, or a copper-type composite material.

1: Terminal for connecting electric wire 2: Connector portion 3: Terminal plate 4: Electric wire 5: Electric wire connecting portion 6: Band material (pipe)
10, 11: Resistance welding electrode 12: Power supply for welding 13: Energization control unit

Claims (6)

The connection part of the wire bundled with a plurality of thin metal wires is covered with a strip made of the same type of metal as the thin wire, and the strip and the wires in the strip are softened by heat treatment while pressing the strip. And by partially destroying these insulating films, it is in a state where it can conduct with the band material,
A terminal structure of an electric wire, wherein the strip is welded by resistance welding to a terminal plate made of the same type or different metal as the metal in the conductive state.   The electric wire terminal structure according to claim 1, wherein the thin wire and the strip are made of aluminum.   3. The electric wire terminal structure according to claim 1, wherein the terminal plate is made of aluminum or copper. Cover the connection part of the wire bundled with a plurality of fine metal wires with a strip made of the same type of metal as the thin wire, and press the strip to reduce the strip and the wires in the strip for a long time. A heat treatment step for softening by energization of electric power and partially breaking these insulating films to make the band material conductive.
A welding step in which the strip is resistance welded by energization with high power in a shorter time than the heat treatment step in the conductive state to the terminal plate made of the same or different metal as the metal, How to connect terminals and wires.   5. The method for connecting a terminal and an electric wire according to claim 4, wherein the thin wire and the strip are made of aluminum. The method for connecting a terminal and an electric wire according to claim 4 or 5, wherein the terminal plate is made of aluminum or copper.

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