JP2010174347A - Method for manufacturing electric wire conductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electric wire conductor made of a copper alloy, which is rarely disconnected and achieves small diameter. <P>SOLUTION: The method for manufacturing the electric wire conductor made of the copper alloy is characterized by a bonding treatment and a heat treatment of joints of the electric wire conductor and comprises steps of: manufacturing a drawing stock of the copper alloy made of desired components by a continuous casting apparatus such as SCR; subjecting the drawing stock to wire drawing (drawing treatment of a drawing stock) by cold working and subsequently to annealing; and carrying out wire drawing (first wire drawing treatment) and further wire drawing (second wire drawing treatment) so as to obtain an element wire for an automotive wire. When carrying out the first and second wire drawing treatments, ends of the electric wire conductor are subjected to a bonding treatment and a heat treatment. The bonding treatment may be carried out before or after the heat treatment. The bonding treatment is a treatment for bonding the end of an electric wire conductor to an end of another electric wire conductor. Preferably, the heat treatment is carried out by heating the joint at 500-850°C for 0.5-30 minutes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a wire conductor used in an automobile electric wire used in an automobile wire harness.

  BACKGROUND ART Wire harnesses for automobiles are widely used in vehicles, for example, as electric wires that electrically connect devices and control devices inside an engine room. In recent years, space saving and weight reduction have been demanded, and accordingly, wire harnesses are required to have a thin wire diameter.

  As an electric wire for automobiles used in a wire harness, conventionally, an annealed copper wire made of pure copper is used as an electric wire conductor, and an outer periphery of a bundle obtained by twisting several electric wire conductors is covered with an insulator such as a resin. . On the other hand, there exists an example which implement | achieved the strength improvement and diameter reduction using the Cu-Sn alloy wire which added tin to pure copper as an electric wire conductor (patent document 1).

  The wire conductors of these automobile wires are generally manufactured from rough drawn wires. That is, a rough drawn wire is manufactured by a continuous casting apparatus, cut at a predetermined length, and wound in a coil shape. Next, the rough drawn wire is drawn (cold working) through a wire drawing device or is annealed through an annealing device to produce a wire conductor having a desired outer diameter. The annealing may be continuous or batch.

  In the wire drawing process, it takes time to connect the wire conductor to the wire drawing device (for example, manually drawing the wire to a wire drawing die or a cooling bath). The ends of the are connected. Thereby, even if it does not carry out a line work, a wire drawing process can be continued. As a method of connecting the ends of the wires, it is common to perform bonding using a commercially available cold weld tool. That is, the end portions of the electric wire conductors are brought into contact with each other, pressed, pressed, deformed, and joined. As a result, the joint portion can have the same strength as the original electric wire conductor, so that the joined portion can be drawn and used as an electric wire conductor.

JP 7-192535 A

  In the case of a conventional electric wire conductor made of pure copper, no disconnection occurred even when the portion where the above-mentioned bonding was performed was drawn. However, when the ends of the copper alloy wires described in Patent Document 1 are connected with a cold weld tool and the joint is drawn, it has been found that the wires are often disconnected. The same applies to other copper alloy wires.

  Then, an object of this invention is to provide the manufacturing method of the electric wire conductor which is hard to be disconnected at a wire drawing process, and respond | corresponded to diameter reduction.

The above-mentioned subject is achieved by the following means. That is, the present invention
(1) A method for producing a copper alloy wire conductor, characterized by performing a joining process and a heat treatment on a joint portion of the wire conductor,
The wire conductor is subjected to a first wire drawing treatment, the joining treatment, the joint portion is heat treated at 500 to 850 ° C. for 0.5 to 30 minutes, and a second wire drawing treatment is performed. Production method,
(2) A method for producing a copper alloy electric wire conductor, characterized in that a bonding process and a heat treatment are performed on a bonded portion of the electric wire conductor,
The wire conductor is subjected to a first wire drawing treatment, the joint is heat treated at 500 to 850 ° C. for 0.5 to 30 minutes, the joint treatment is performed, and a second wire drawing treatment is performed. Manufacturing method,
(3) The method for producing a wire conductor according to (1) or (2), wherein at least one of the wire conductors is made of a copper alloy containing 0.1 to 10% by mass of Sn.
Is provided.

  In the method for producing an electric wire conductor of the present invention, by performing a heat treatment on the joint portion between the wires, the wire conductor is prevented from being broken in the wire drawing step, and the efficiency of the changeover work can be improved.

  The electric wire conductor of the present invention is made of a copper alloy containing Sn, Ni, Si, Zn, Mg, Fe, Co, P, Mn, Be and the like. For example, there is a copper alloy containing 0.1 to 10% by mass of Sn or a copper alloy containing 0.1 to 10% by mass of Ni, Co and Si. A preferable wire conductor for an automobile is a copper alloy containing 0.1 to 2.0% by mass of Sn, or 0.1 to 3.0% by mass in total of Ni and Co, and 0.1% of Si. It is a copper alloy containing -0.7 mass%. Moreover, the electric wire conductor of this invention consists of a wire whose outer diameter of a conductor is 0.1-10 mm.

The manufacturing method of the electric wire conductor of this invention is demonstrated. A rough drawn wire of a copper alloy made of a desired component is produced by a continuous casting apparatus such as SCR. Next, the rough drawn wire is drawn by cold working (drawing processing of the rough drawn wire), and then subjected to a continuous annealing treatment. Next, wire drawing processing (first wire drawing treatment) is performed by cold working, and wire drawing processing (second wire drawing treatment) is further performed by cold working to obtain a wire for an automobile electric wire.
At this time, between the first wire drawing process and the second wire drawing process, an end portion of the wire conductor is subjected to a bonding process and a heat treatment. In addition, before the second wire drawing process, a bonding process and a heat treatment are performed on the end portion of the wire conductor. The order of the joining process and the heat treatment is not limited.

  The joining process of the present invention is performed with a commercially available cold weld tool. Generally, the end portion of one electric wire conductor and the end portion of the other electric wire conductor are brought into contact with each other and fixed with a pair of chucks. Next, the pair of chucks are brought close to each other by a certain distance so as to press both the wire conductors. Thereby, the edge part of both electric wire conductors plastically deforms, and both electric wire conductors are mechanically connected by a joining surface by pressing against surfaces without a dust and an oxide layer, and a joining process is completed. Along with the deformation, a protrusion called a burr protrudes around the wire conductor in the radial direction on the joint surface. The burr is removed with a file or the like so that the outer diameter of the wire conductor is substantially constant.

  Unlike the longitudinal direction of the electric wire conductor, the joint is plastically deformed in a direction approximately 90 degrees from the longitudinal direction. For this reason, the crystal structure of the copper alloy also has a long crystal structure in the direction different from the direction of about 90 degrees in the longitudinal direction and the joint portion. In general, in a metal structure, processing in a long direction of a crystal structure can be relatively tolerated. However, in the joint portion, a wire drawing process is locally different from a long direction of the crystal structure, and therefore, disconnection occurs in the wire drawing process. It is thought that it becomes easy to do.

  Further, in the burr removing operation, it is difficult to remove the surface flaws by manual work or the like, and it is considered that the surface flaws are drawn with the flaws remaining and become the starting point of breakage when passing through the drawing dies.

  Next, heat treatment is performed. In the heat treatment of the present invention, at least the joint is heated by a heating device. The heating method may be an energization method or a burner method. The periphery of the joint may be heated. The periphery refers to a length of about 1 m before and after the joint. The heating conditions are 500 to 850 ° C. and preferably 0.5 to 30 minutes. When the heat treatment temperature is less than 600 degrees, the effect of the heat treatment is small and disconnection is likely. Moreover, the heat processing exceeding 850 degreeC will be in the state of over-annealing, toughness will fall and it will become easy to break. More preferably, it is 600-800 degreeC, More preferably, it is 650-750 degreeC.

  If the heat treatment time is less than 0.5 minutes, the effect of the heat treatment is small and the wire breaks easily. Moreover, when heat processing time exceeds 30 minutes, it will be in the state of over-annealing and toughness will fall and it will become easy to disconnect. More preferably, it is 1-20 minutes, More preferably, it is 2-5 minutes.

  By performing the heat treatment of the present invention on the joint, the processing strain is removed in the crystal structure of the joint, or a part of the structure is partially recrystallized, so that the direction of wire drawing And the difference in the orientation of the crystal structure is relaxed. Thereby, even if a surface flaw exists in the joint portion, it becomes difficult to break when the joint portion is drawn.

  Further, even when the heat treatment of the present invention is performed before the bonding treatment, it is difficult to break similarly. This is because the difference in the orientation of the crystal structure direction of the joint portion is alleviated by performing the joining process in a state in which processing strain is removed or partial recrystallization occurs.

  In addition, heat processing is performed within about 1 m before and behind the said junction part. When heat treatment is performed on the entire wire conductor, when a plurality of wire conductors are bundled and twisted to form an automobile wire, desired characteristics cannot be obtained as an automobile wire.

  The joining treatment of the present invention may be the joining of the wire conductors of Cu—Sn alloy wires or the joining of the wire conductors of different components. For example, if at least one electric wire conductor is a copper alloy containing 0.1 to 10% by mass of Sn, the effect of the present invention can be achieved even if the other electric wire conductor is a copper alloy made of pure copper, which is a conventional product. Is obtained.

  Hereinafter, the manufacturing method of an electric wire conductor is demonstrated in detail. A copper alloy rough wire (outer diameter 8 mm) made of a desired component was produced by a continuous casting apparatus such as the SCR of the present invention. The components used were a copper alloy (Cu-1.0Sn) added with 1.0% by mass of Sn and pure copper (Cu).

  Subsequently, the rough drawn wire was subjected to wire drawing processing (first wire drawing treatment) to an outer shape of 2.6 mm by cold working, and annealing treatment was performed in a non-oxidizing atmosphere. Next, wire drawing (second wire drawing) was performed to an outer diameter of about 0.2 mm to obtain an automobile electric wire. At this time, when the second wire drawing process was performed, the end portion of the wire conductor was subjected to a bonding process and a heat treatment. The bonding treatment and the heat treatment were both manufactured after the bonding treatment (bonding → heat treatment) and manufactured by the bonding treatment after the heat treatment (heat treatment → bonding). In addition, the electric wire conductor which does not heat-process as a comparative example was also produced.

  The joining process was performed using a commercially available cold weld tool (manufactured by Sumiden Asahi Seiko: ABM-5 type). The conditions were that the StopArm interval was 40 mm and the number of times of pressing was 10 times. Next, the joint portion was deburred with a file, and the surface of the joint portion of the wire conductor was polished, and it was visually confirmed that there was no roughness or scratch.

  In the case of heat treatment after the joining treatment, the joining portion and about 1 m before and after the joining portion were heated through the inside of a heating furnace, and the other wire conductors were not subjected to heat treatment. When heat treatment is performed before the joining process, about 0.5 m from one end of one wire conductor to be joined and about 0.5 m from one end of the other wire conductor are passed through the inside of the heating furnace. The other wire conductors were not heat-treated. The heating conditions were those described in Table 1.

  The joint portion of the obtained electric wire conductor was passed through a wire drawing device, and was subjected to wire drawing to an outer diameter of 0.2 mm. At that time, the presence or absence of occurrence of disconnection at the joint was evaluated. In the evaluation, when the disconnection does not occur in the joint portion, it is determined as “good” and marked with “◯”, and when the disconnection occurs in the joint portion, it is determined as “bad” and the mark “×” is marked. It was attached. The results are shown in Table 1.

  As is clear from the results in Table 1, no breakage occurred during wire drawing in the joint portion of the wire conductor manufactured by the method for manufacturing a wire conductor of the present invention. However, disconnection occurred in the comparative example in which the heat treatment was not performed on the joint. Also, disconnection occurred if the heat treatment conditions were not appropriate.

Claims (3)

A method of manufacturing a copper alloy electric wire conductor, wherein a bonding process and a heat treatment are performed on a bonding portion of the electric wire conductor, wherein the electric wire conductor is subjected to a first wire drawing treatment, the bonding treatment, and the bonding portion 500 A method for producing an electric wire conductor, comprising heat-treating at ~ 850 ° C for 0.5 to 30 minutes and performing a second wire drawing treatment. A method for producing a copper alloy electric wire conductor, characterized in that the electric wire conductor is subjected to a bonding treatment and a heat treatment, wherein the electric wire conductor is subjected to a first wire drawing treatment, and the bonding portion is heated at 500 to 850 ° C. Heat treatment for 5 to 30 minutes, the joining treatment, and the second wire drawing treatment. At least one of the said wire conductor consists of a copper alloy containing 0.1-10 mass% of Sn, The manufacturing method of the wire conductor of Claim 1 or Claim 2 characterized by the above-mentioned.