JP2010009794A - Joining method of terminal and electric wire and electrode used for this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method of a terminal and an electric wire, joining the terminal and the electric wire while preventing break of the wire in the case where a terminal is to be joined to a wire with a material different from the terminal, and also to provide an electrode used for the joining. <P>SOLUTION: The wire 5 retained by a wire connecting part 3 is soldered with flux and solder put in a heated state under no stress by electric conduction to fusion welding electrodes 7, 8, so that the wire 5 is joined to a terminal 1 without being crimped unlike a conventional case, and joining of the terminal 1 and the wire 5 is made with break of the wire 5 prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a terminal-to-electric wire joining method for joining a terminal made of a material different from that of an electric wire to the electric wire, and an electrode used therefor.

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

  Because of the above advantages, aluminum and aluminum alloy wires are used for wire harnesses such as battery cables and ground cables for automobiles and IH coils for electromagnetic cookers in order to reduce the overall weight of the car and improve fuel efficiency. I am trying to do. In this case, a terminal structure that melts the insulation coating and joins the wire and the terminal by heating while sandwiching and heating the wire coated with the fusing welding electrode or the resistance welding electrode is conventionally known ( For example, Patent Document 1).

  However, when aluminum or the like is used for the electric wire, it is necessary to join a copper or copper alloy terminal made of a different material. However, in the case of an automobile wiring harness, contact between the electric wire and the terminal is caused by rainwater. As a result, the electric wire is corroded, and there is a risk of inducing troubles such as inability to start the engine. Further, in the IH coil of an electromagnetic cooker, when hot water or the like at the time of boiling is present, electric contact is similarly generated, and the electric wire is corroded, which may cause trouble such as inability to cook.

For this reason, conventionally, as a watertight sealing structure in which the entire crimping part is hot-melt molded after crimping and connecting an aluminum wire to a terminal fitting, a crimping connection structure with an improved anti-electrical contact function is known (for example, patents) Reference 2).
JP 2000-277325 A JP 2006-286385 A

  However, when a wire made of aluminum or an aluminum alloy is joined to a terminal by a pressure connection that pressurizes and heats as in the past, the strength of the wire is lower than that made of copper or copper alloy, and the wire is broken by the pressure. There was a problem that there was.

  The present invention provides a method of joining a terminal and an electric wire capable of joining the terminal and the electric wire while preventing the electric wire from being bent when joining a terminal made of a material different from that of the electric wire to the electric wire, and an electrode used therefor. Objective.

  In order to achieve the above object, a method of joining a terminal and an electric wire according to one configuration of the present invention is to join a terminal made of a material different from an electric wire and having a connector portion and an electric wire connecting portion to the electric wire at the electric wire connecting portion. In the state where the electric wire held in the electric wire connecting portion is heated under no stress by energizing the fusing welding electrode or the resistance welding electrode, flux and solder are put into the electric wire and the electric wire is soldered to the terminal. Attach. Here, “under no stress” means a state in which no internal stress is generated as a result of not receiving an external force.

  According to this configuration, since the electric wire held in the electric wire connecting portion is heated under no stress by energizing the fusing welding electrode or the resistance welding electrode, flux and solder are put into the electric wire and soldered. Unlike the conventional case, since the electric wire is joined to the terminal without being crimped, it is possible to join the terminal and the electric wire while preventing the electric wire from being broken.

  Preferably, a plurality of caulking pieces spaced apart in the direction in which the electric wires extend are provided in the electric wire connecting portion, and the electric wires are held by the caulking pieces under no stress. Then, flux and solder are introduced into the electric wires in this order from the gaps between the caulking pieces, and the electric wires are soldered to the terminals. Therefore, since the electric wire held under no stress by the caulking piece is heated under no stress, the terminal and the electric wire can be joined while preventing the electric wire from being broken more effectively.

  Preferably, the electric wire is a stranded wire made of aluminum or an aluminum alloy, and the terminal is made of copper or a copper alloy. Moreover, the said electric wire bundles many said strands. Therefore, not only the surface of the stranded wire bundle but also the inside of the stranded wire bundle is firmly soldered by the above connection method, so that the terminal and the electric wire can be joined more firmly.

  The electrode consisting of a fusing welding electrode or a resistance welding electrode used in the method for joining the terminal and the electric wire according to another configuration of the present invention is in a state where the electric wire held in the electric wire connecting portion is sandwiched under no stress, The wire has a charging hole for charging the flux and solder. Therefore, the heating of the electric wire, the introduction of the flux and the solder into the electric wire can be easily performed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a connection state between terminals and electric wires according to the first embodiment of the present invention. As shown in FIG. 1A, the terminal 1 is made of a material different from that of the electric wire 5 and has a connector portion 2 and an electric wire connecting portion 3. As shown in FIG. 1B, the electric wire 5 is joined to the terminal 1 while being held by the electric wire connection portion 3.

  As shown in FIG. 1A, the electric wire 5 is made of, for example, a bundle of many strands made of aluminum or aluminum alloy, and the terminal 1 is a piece of copper alloy such as copper or brass made of a different material. The caulking piece 6 of the electric wire connecting portion 3 to be described later is formed by bending.

  In order to hold the electric wire 5, a plurality of, for example, four caulking pieces 6 that are separated from each other along the longitudinal direction, which is the direction in which the electric wire 5 extends, are provided in the electric wire connecting portion 3. Since the caulking pieces 6 are spaced apart from each other, the gap portions 11 are formed between the caulking pieces 6 in a state where the caulking pieces 6 in FIG. Flux and solder are put into the electric wire 5 from the gap 11.

  Further, the four caulking pieces 6 are alternately provided at positions along the direction (longitudinal direction) in which the electric wires 5 extend in the electric wire connecting portion 3. As shown in FIG. 1A, two caulking pieces 6-1 and 6-3 provided on one (left side) of both lateral ends of the electric wire connecting portion 3 and 2 provided on the other (right side). The two caulking pieces 6-2 and 6-4 do not face each other and do not interfere with each other even if bent inward, and are alternately arranged with the gap 11 as shown in FIG. Placed in. A through-hole 12 is provided at the tip of each caulking piece 6 and is used mainly for removing gas generated during soldering. However, it may be used as a hole for introducing flux and solder described later. . Note that this through hole 12 may not be provided.

  The electric wire 5 is held by each caulking piece 6 under no stress. In other words, the electric wires 5 are not firmly caulked and fixed by the caulking pieces 6, but the caulking pieces 6 are loosely bent along the outer shape of the bundle of stranded wires, so that the electric wires 5 are broken in the electric wire connection portion 3. It is held to the extent that it does not hit. And since each crimping piece 6 is bent alternately, the shakiness of the horizontal direction of the electric wire 5 can be suppressed more effectively, and can be hold | maintained.

  FIG. 2 is a perspective view showing the configuration of the terminal and electric wire joining method according to the first embodiment of the present invention. This connection method is applied, for example, to an electric wire of an IH coil of an electromagnetic cooker. In this example, a pair of fusing welding electrodes 7 and 8 and an energization control unit 10 for energizing the electrodes are provided, and the electric wire 5 held by the electric wire connection part 3 of the terminal 1 in the horizontal state is connected to the fusing. It is sandwiched between the welding electrodes 7 and 8 under no stress and energized by the energization controller 10 to be heated. The upper electrode 7 of the fusing welding electrode is provided with a plurality of charging holes 15 for charging flux and solder into the electric wire 5.

  In addition, the bottom surface 7 b of the upper electrode 7 is provided with a storage recess 13 for storing the wire connection portion 3 that holds the wire 5 with the crimping piece 6. Thereby, the pressurization to the electric wire 5 can be made smaller. Each charging hole 15 is provided so as to penetrate from the side surface 7a of the upper electrode 7 to the housing recess 13 of the bottom surface 7b, and is arranged so that the gap 11 between the caulking pieces 6 can be viewed downward. From this charging hole 15, flux is supplied to the electric wire 5 through the gap 11 to remove the oxide film formed on the aluminum surface of the electric wire 5, and then solder is supplied so that the electric wire 5 is connected to the terminal 1. Soldered to the wire connection part 3.

(Example)
For example, the electric wire 5 is a bundle of many aluminum stranded wires (0.29φ), and the terminal 1 is made of brass. As shown in FIG. 2, the electric wire 5 held by the caulking piece 6 in the electric wire connecting portion 3 under no stress is sandwiched from above and below by the pair of fusing welding electrodes 7 and 8 under no stress.

  An energization current is set by the energization control unit 10 so that the electric wire 5 contacting the fusing welding electrodes 7 and 8 is heated to a temperature range of 300 to 650 ° C., and energized for 1 to 1.5 seconds. In this heated state, flux is charged from the charging hole 15 of the upper electrode 7 to the electric wire 5 through the gap 11 between the caulking pieces 6. The oxide film formed on the aluminum surface of the electric wire 5 is removed by the flux. Similarly, 0.5 to 1 second after the flux is introduced, solder is introduced into the electric wire 5 through the gap 11 between the caulking pieces 6, and the electric wire 5 is soldered to the electric wire connecting portion 3 of the terminal 1.

  In this way, the electric wire 5 consisting of a bundle of a large number of stranded wires is held under no stress by the caulking pieces 6 and is heated in the temperature range by the fusing welding electrodes 7 and 8 so that the flux is introduced. The oxide film formed on the aluminum surface of each stranded wire is removed, and solder is introduced immediately thereafter, so that the solder instantaneously enters the center of the bundle of each stranded wire by capillary action between the stranded wires. . For this reason, since it solders not only to the surface of the strand wire bundle of the electric wire 5 but the inside of a strand wire bundle, firm soldering is attained.

  As a result, since the electric wire 5 held by the electric wire connection portion 3 is heated under no stress by the fusing welding electrodes 7 and 8, flux and solder are poured into the electric wire 5 and soldered. Since the electric wire 5 is joined to the terminal 1 without being crimped, the terminal 1 and the electric wire 5 can be joined while preventing the electric wire 5 from being broken.

  FIG. 6 shows a second embodiment. The second embodiment is different from the first embodiment in that the terminal 1 is placed in a horizontal state and the wire connection part 3 holding the wire 5 is sandwiched between the fusing welding electrodes 7 and 8 so that the terminal 1 is made vertical. Thus, the electric wire connecting portion 3 holding the electric wire 5 is sandwiched between the fusing welding electrodes 7 and 8 from side to side. Further, the fusing electrodes 7 and 8 are not provided with the introduction hole 15 as in the first embodiment, and the flux and solder are introduced from above the electric wire 5 in the bundle of stranded wires. Other configurations are the same as those of the first embodiment.

  Similarly to the first embodiment, the second embodiment can join the terminal and the electric wire while preventing the electric wire from being broken.

  In addition, in each said embodiment, although the electric wire 5 is made into the bundle of a strand wire, it is good also as a bundle of a round wire. Moreover, although this connection method is applied to the electric wire of the IH coil of an electromagnetic cooker, you may apply to the electric wire for wire harnesses of a motor vehicle.

  In addition, in each said embodiment, although the electric wire is heated with the fusing welding electrode, you may heat with a resistance welding electrode.

It is a perspective view which shows the connection state of the terminal and electric wire concerning 1st Embodiment of this invention. It is a perspective view which shows the structure of the connection method of the terminal and electric wire concerning 1st Embodiment of this invention. It is a perspective view which shows the structure of the connection method of the terminal and electric wire concerning 2nd Embodiment.

Explanation of symbols

1: Terminal 2: Connector part 3: Wire connection part 5: Electric wire 6: Caulking piece 7, 8: Fusing welding electrode 10: Current supply control part 11: Gap part 15: Insertion hole

Claims (5)

A terminal made of a material different from an electric wire and having a connector part and an electric wire connection part, and a method of joining the electric wire to the electric terminal at the electric wire connection part and the electric wire,
In a state where the electric wire held in the electric wire connecting portion is heated under no stress by energizing the fusing welding electrode or the resistance welding electrode, a terminal for soldering the electric wire to the terminal by introducing flux and solder into the electric wire Electric wire joining method. In claim 1,
A plurality of caulking pieces spaced apart along the direction in which the electric wires extend are provided in the electric wire connecting portion, and the electric wires are held under no stress by the caulking pieces,
A method of joining a terminal and an electric wire, in which, in the heated state of the electric wire, flux and solder are introduced into the electric wire in this order from the gap between the caulking pieces and the electric wire is soldered to the terminal. In claim 1,
A method for joining a terminal and an electric wire, wherein the electric wire is a stranded wire made of aluminum or an aluminum alloy, and the terminal is made of copper or a copper alloy. In claim 3,
A method for joining a terminal and an electric wire, wherein the electric wire is a bundle of a number of the stranded wires. An electrode comprising a fusing welding electrode or a resistance welding electrode used in the method for joining a terminal and an electric wire according to any one of claims 1 to 4,
The electrode has a feeding hole for feeding the flux and solder into the electric wire in a state where the electric wire held in the electric wire connecting portion is sandwiched under no stress, and a method for joining the terminal and the electric wire Electrodes used in

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