JP2013242991A - Junction structure for electric wires - Google Patents

Abstract

When a copper core wire and an aluminum core wire are joined by welding, the joining strength between the core wires is increased without requiring a complicated operation.
An electric wire joining structure includes a joining portion between a copper core wire in a copper electric wire and an aluminum core wire in an aluminum electric wire. The end portion of the copper core wire 21 is provided with a forming portion 23 formed into a shape that forms a groove 23a into which the aluminum core wire 31 is fitted. Further, the joint portion 4 is a portion where the formed portion 23 of the copper core wire 21 and the end portion of the aluminum core wire 31 fitted in the groove 23a of the formed portion 23 are welded.
[Selection] Figure 1

Description

  The present invention relates to a joining structure of electric wires provided with a joint portion between a copper core wire mainly composed of copper and an aluminum core wire mainly composed of aluminum.

  In recent years, lightweight aluminum is being adopted as a material for core wires of electric wires that replace copper. Along with this, when connecting a plurality of insulated wires, it is necessary to join a conventionally used copper core wire mainly composed of copper and an aluminum core wire mainly composed of aluminum by welding. There is. As a technique for welding the core wires, ultrasonic welding is suitable.

  For example, Patent Document 1 discloses joining a copper core wire and an aluminum core wire by ultrasonic welding.

JP 2010-1113946 A

  By the way, when a copper core wire and an aluminum core wire are joined by welding, since the strength of the welded portion of the aluminum core wire is low, there arises a problem that the joint strength between the core wires is weakened.

  On the other hand, Patent Document 1 discloses that ultrasonic welding is performed from the outer copper core wire side in a state where the aluminum core wire is embedded in a plurality of strands constituting the copper core wire. Thereby, the area of the welding part with respect to the copper core wire in an aluminum core wire increases, and the joint strength of core wires increases.

  However, the electric wire joining structure disclosed in Patent Document 1 requires a complicated operation of embedding an aluminum core wire in a plurality of strands constituting a copper core wire, and it is difficult to automate such an operation. Therefore, the electric wire joining structure disclosed in Patent Document 1 is not suitable for application to mass-produced wire harnesses.

  An object of this invention is to raise the joining strength of core wires, without requiring a complicated operation, when a copper core wire and an aluminum core wire are joined by welding.

  The joining structure of the electric wire which concerns on the 1st aspect of this invention has the junction part of the copper core wire which has copper as a main component in a 1st insulated wire, and the aluminum core wire which has aluminum as a main component in a 2nd insulated wire. I have. Furthermore, the electric wire joining structure includes a forming portion which is a portion formed in a shape that forms a groove into which the aluminum core wire is fitted in the terminal portion of the copper core wire. Moreover, the said junction part is the part where the said shaping | molding part of the said copper core wire and the terminal part of the said aluminum core wire inserted in the groove | channel of the shaping | molding part were welded.

  The electric wire joining structure according to the second aspect of the present invention is an aspect of the electric wire joining structure according to the first aspect. In the electric wire joining structure according to the second aspect, the end portion of the copper core wire and the end portion of the aluminum core wire are the same from the insulation coating of the first insulated wire and the second insulated wire arranged in parallel. It extends in the direction.

  In the electric wire joining structure according to each of the above aspects, the end portion of the copper core wire is provided with a forming portion formed into a shape that forms a groove into which the aluminum core wire is fitted. And a junction part is a part by which the shaping | molding part and the terminal part of the aluminum core wire inserted in the groove | channel of the shaping | molding part were welded. Therefore, the outer peripheral surface of the aluminum core wire and the inner surface of the groove in the molded portion of the copper core wire are in surface contact over a wide area, and a wide welded portion (joint portion) is formed. As a result, the bonding strength between the core wires is increased.

  In addition, forming the end portion of the copper core wire into a shape that forms a groove can be easily realized by a general processing step such as pressing. Therefore, according to the joining structure of the electric wires according to each aspect described above, when the copper core wire and the aluminum core wire are joined by welding, it is possible to increase the joining strength between the core wires without requiring a complicated operation. Become.

  Moreover, according to this invention, it can apply also when the junction part of core wires is formed in the terminal part of the two insulated wires arrange | positioned in parallel like the joining structure of the electric wire which concerns on a 2nd aspect. In addition, the joining structure of the electric wire shown by patent document 1 is applicable only when the terminal part of a copper core wire and the terminal part of an aluminum core wire are opposingly arranged.

It is a perspective view of the junction structure 1 of the electric wire which concerns on 1st Embodiment of this invention. It is a perspective view of the two insulated wires which comprise the joining structure 1 of an electric wire. It is a side view of the press apparatus and copper electric wire used for the formation process of a copper core wire. It is sectional drawing of the press apparatus and copper electric wire which are used for the formation process of a copper core wire. It is sectional drawing of a press apparatus when shape | molding a copper core wire. It is a perspective view of the welding process for obtaining the joining structure 1 of an electric wire. It is a perspective view of 1 A of joining structures of the electric wire which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example embodying the present invention, and is not an example of limiting the technical scope of the present invention.

<First Embodiment>
First, the configuration of the electric wire joining structure 1 according to the first embodiment of the present invention will be described with reference to FIGS. The electric wire joining structure 1 is a structure in which core wires of two insulated electric wires are joined together by welding. The first insulated electric wire is a copper electric wire 2 having a copper core wire 21 that is a core wire mainly composed of copper and an insulating coating 22 that covers the periphery of the copper core wire 21. The second insulated wire is an aluminum wire 3 having an aluminum core wire 31 that is a core wire mainly composed of aluminum, and an insulating coating 32 that covers the periphery of the aluminum core wire 31.

  The copper core wire 21 shown in FIGS. 1 and 2 is a stranded wire formed by twisting strands made of copper or a copper alloy. Similarly, the aluminum core wire 31 shown in FIGS. 1 and 2 is a stranded wire formed by twisting strands made of aluminum or an aluminum alloy. In addition, it is possible that the copper core wire 21 and the aluminum core wire 31 are comprised by the some strand which is not twisted together, or it is comprised by the single wire.

  In the copper wire 2, the end portion of the copper core wire 21 is stripped of the insulating coating 22 and extends from the end of the insulating coating 22. Similarly, the end portion of the aluminum core wire 31 is stripped of the insulating coating 32 and extends from the end of the insulating coating 32.

  In the following description, the portion of the copper core wire 21 that extends from the insulating coating 22 is referred to as a bare copper core wire portion 21a. Similarly, the portion of the aluminum core wire 31 that extends from the insulating coating 32 is referred to as a bare aluminum core portion 31a.

  As shown in FIGS. 1 and 2, the end of the bare copper core wire portion 21a is formed in a shape that forms a groove 23a into which the bare aluminum core wire portion 31a is inserted. Hereinafter, the part molded in this way is referred to as a molded part 23.

  In the example shown in FIGS. 1 and 2, the molded portion 23 of the bare copper core wire portion 21 a is a portion formed in a semi-cylindrical shape. In this case, the molded part 23 is formed in a semi-cylindrical shape in which the inner groove 23a forms a circumferential surface along the outer peripheral surface of the bare aluminum core part 31a, for example.

  In the electric wire bonding structure 1, the bonding portion 4, which is a portion where the core wires are bonded to each other, has a bare aluminum core wire portion 31 a fitted in the molding portion 23 of the bare copper core wire portion 21 a and the groove 23 a of the molding portion 23. And are welded parts. The joint portion 4 is formed over the entire interface between the entire inner surface of the groove 23a of the molded portion 23 and the outer peripheral surface of the bare aluminum core portion 31a.

  Moreover, in the electric wire joining structure 1, each of the bare copper core wire portion 21a and the bare aluminum core wire portion 31a extends in the same direction from the insulation coatings 22 and 32 of the copper wire 2 and the aluminum wire 3 arranged in parallel. Is formed.

<Wire joining procedure>
Next, an example of a procedure for producing the electric wire joining structure 1 will be described with reference to FIGS. FIG. 3 is a side view of the pressing device 5 and the copper wire 2 used in the forming process of the bare copper core wire portion 21a. 4 is a cross-sectional view of the pressing device 5 and the copper electric wire 2, and is a cross-sectional view in the II-II plane shown in FIG. FIG. 5 is a cross-sectional view of the pressing device 5 when the bare copper core wire portion 21a is being formed. FIG. 6 is a perspective view of a welding process for obtaining the electric wire joining structure 1.

  In producing the electric wire joining structure 1, first, the end portion of the bare copper core wire portion 21 a is formed, and the forming portion 23 is formed. For forming the end portion of the bare copper core wire portion 21a, for example, a press device 5 as shown in FIGS. 3 to 5 is used.

  The pressing device 5 includes a lower mold 51 and an upper mold 52 that sandwich the bare copper core wire portion 21a. The press device 5 also includes a lifting drive unit (not shown) that moves the upper die 52 close to and away from the lower die 51.

  The upper surface of the lower mold 51 and the lower surface of the upper mold 52 constitute a mold that forms the semi-cylindrical molded part 23. Therefore, as shown in FIG. 5, when the end portion of the bare copper core portion 21 a is sandwiched between the upper surface of the lower mold 51 and the lower surface of the upper mold 52, the end portion of the bare copper core wire portion 21 a becomes a semi-cylindrical molded portion 23. Press molded.

  Next, as shown in FIG. 6, with the bare aluminum core wire portion 31a fitted into the groove 23a of the forming portion 23 of the bare copper core wire portion 21a, the bare aluminum core wire portion 31a and the bare copper core wire portion 21a The aluminum core wire portion 31 a is welded by the ultrasonic welding machine 7.

  In the welding process, when the molded portion 23 of the bare copper core wire portion 21a and the bare aluminum core wire portion 31a mainly composed of aluminum having a melting point significantly lower than that of copper are welded by the ultrasonic welder 7, ultrasonic waves are used. It is desirable that the welding machine 7 and each electric wire are arranged as shown in FIG.

  That is, it is desirable that the welding horn 71 of the ultrasonic welding machine 7 is arranged on the molding part 23 side of the bare copper core part 21a, and the anvil 72 of the ultrasonic welding machine 7 is arranged on the bare aluminum core part 31a side. . At this time, the output of the welding horn 71 is set to a sufficiently high output so that the bare copper core wire portion 21a having a high melting point can be welded.

  By arranging the ultrasonic welder 7 as described above, the high-power ultrasonic waves output from the welding horn 71 cause the molded portion 23 of the bare copper core portion 21a to be welded to the bare aluminum core portion 31a. . Further, the ultrasonic wave whose energy has been attenuated through the forming portion 23 does not excite the bare aluminum core portion 31a excessively, and the bare aluminum core wire portion 31a is moved with respect to the forming portion 23 of the bare copper core wire portion 21a with an appropriate power. Weld.

  Note that when high-power ultrasonic waves are directly applied to the bare aluminum core part 31a having a low melting point, the bare aluminum core part 31a may be excessively excited and scattered. Further, when the output of the welding horn 71 is set to a weak power suitable for welding the bare aluminum core part 31a, the molded part 23 of the bare copper core part 21a cannot be welded to the bare aluminum core part 31a. .

  In the example shown in FIG. 6, the ultrasonic output surface of the welding horn 71 is a curved surface along the outer peripheral surface of the semi-cylindrical molded part 23. Thereby, the ultrasonic wave is uniformly applied to the entire interface between the inner surface of the groove 23a of the molded part 23 and the outer peripheral surface of the bare aluminum core part 31a, and the joint 4 is uniformly formed on the entire interface.

Second Embodiment
FIG. 7 is a perspective view of an electric wire joining structure 1A according to a second embodiment of the present invention. This electric wire joining structure 1 </ b> A differs from the electric wire joining structure 1 shown in FIG. 1 only in the direction of the aluminum electric wire 3 relative to the copper electric wire 2. In FIG. 7, the same components as those shown in FIG. 1 are given the same reference numerals. Hereinafter, only the differences from the wire bonding structure 1 in the wire bonding structure 1A will be described.

  In the electric wire joining structure 1A, the copper electric wire 2 and the aluminum electric wire 3 are arranged in series, and the bare copper core wire portion 21a and the bare aluminum core wire portion 31a are arranged to face each other. The joining portion 4 in the wire joining structure 1A is also a portion where the forming portion 23 of the bare copper core wire portion 21a and the bare aluminum core wire portion 31a fitted in the groove 23a of the forming portion 23 are welded. The joint portion 4 is formed over the entire interface between the entire inner surface of the groove 23a of the molded portion 23 and the outer peripheral surface of the bare aluminum core portion 31a.

  As shown in FIGS. 1 and 7, in the present invention, the end portion of the copper core wire and the end portion of the aluminum core wire are arranged in parallel, and the end portion of the copper core wire and the end portion of the aluminum core wire are opposed to each other. It is applicable to both cases.

<Effect>
In the electric wire joining structures 1 and 1A, the end portion of the copper core wire 21 is provided with a forming portion 23 formed into a shape that forms a groove 23a into which the aluminum core wire 31 is fitted. And the junction part 4 is the part by which the shaping | molding part 23 and the terminal part of the aluminum core wire 31 inserted in the groove | channel 23a of the shaping | molding part 23 were welded. Therefore, the outer peripheral surface of the aluminum core wire 31 and the inner surface of the groove 23a in the molding portion 23 of the copper core wire 21 are in surface contact over a wide area, and a wide welded portion (joint portion 4) is formed. As a result, the bonding strength between the core wires is increased.

  Further, it is possible to easily form the end portion of the copper core wire 21 into a shape that forms the groove 23a by a general processing step such as pressing. Therefore, according to the electric wire joining structures 1 and 1A, when the copper core wire 21 and the aluminum core wire 31 are joined by welding, the joining strength between the core wires can be increased without requiring a complicated operation. .

  Moreover, the structure of the present invention is applicable to the case where the joint 4 between the core wires is formed at the end portions of the two insulated wires 2 and 3 arranged in parallel, like the joint structure 1 of the wire, Further, the present invention is also applicable to the case where the joint portion 4 between the core wires is formed at the end portions of the two insulated wires 2 and 3 arranged in series as in the wire joining structure 1A.

1,1A Wire connection structure 2 Copper wire (first insulated wire)
3 Aluminum wire (second insulated wire)
4 Joining portion 5 Press device 7 Ultrasonic welding machine 21 Copper core wire 21a Bare copper core wire portion 22, 32 Insulation coating 23 Molded portion 23a Groove 31 Aluminum core wire 31a Bare aluminum core wire portion 51 Lower die 52 Upper die 71 Welding horn 72 Anvil

Claims (2)

It is a joining structure of an electric wire provided with a joining portion of a copper core wire mainly composed of copper in the first insulated wire and an aluminum core wire mainly composed of aluminum in the second insulated wire,
A molded part that is a part formed in a shape that forms a groove into which the aluminum core wire is fitted, at the end of the copper core wire,
A joining structure of an electric wire comprising: the joining portion, which is a welded portion of the forming portion of the copper core wire and a terminal portion of the aluminum core wire fitted in a groove of the forming portion. The electric wire joining structure according to claim 1,
The end portions of the copper core wire and the end portions of the aluminum core wire are each formed by extending in the same direction from the insulation coating of the first insulated wire and the second insulated wire arranged in parallel. Bonding structure.

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