JPH0727729B2 - Method for manufacturing conductors for audio / visual equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a conductor used for wiring equipment such as image display equipment and audio equipment that requires a high-frequency signal transmission circuit.

[Prior Art] In these electronic devices, unless signals are accurately transmitted without causing a phase difference, images and sound are adversely affected. That is, the image is blurred or the sound is not clear.

Conventionally, as conductors for audio / visual equipment, tough pitch copper and oxygen-free copper have been cold-worked, then annealed and softened to recrystallize, annealed copper wire, hard-copper wire as cold-worked, or tin-plated Wires and the like have been used.

However, these lines have not always been suitable for accurate signal transmission for the following reasons.

In the case of annealed copper wire, recrystallization by annealing usually causes the crystal grains to be distributed in an equiaxed shape. Therefore, when a current flows in the longitudinal direction of the conductor, the number of crystal grain boundaries that the current may cross increases. It is considered that such a crystal grain boundary has a great effect on a high-frequency component signal, especially as a cause of a phase difference or the like.

On the other hand, the hard copper wire has the shape of a crystal that extends in the longitudinal direction in a fibrous shape, so that the number of crystal grain boundaries that may cross when a current flows in the longitudinal direction is apparently smaller than that of the annealed copper wire. . Therefore, the adverse effect of the crystal grain boundary is less likely to be received as compared with the annealed copper wire. On the other hand, atomic vacancies (point defects),
The density of dislocations (linear crystal defects) becomes extremely larger than that of the annealed copper wire, and moreover, the electron density becomes inhomogeneous, which is inappropriate for electrical conduction. It is considered that these cause a phase difference in the high frequency component signal.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a method for manufacturing a conductor for audio / visual equipment having excellent signal transmission characteristics.

[Means for Solving Problems] and [Effects of the Invention] A method for manufacturing a conductor for audio / visual equipment according to the present invention comprises:
A copper wire with an oxygen content of 30 ppm or less is subjected to a softening treatment in an intermediate step, and then is not recrystallized. Characterized by drawing up to a wire.

The use of a copper wire having an oxygen content of 30 ppm or less means that if the oxygen content exceeds 30 ppm, Cu ₂ O grains are present in the crystal grain boundaries, which makes copper extremely brittle, which may cause acoustic or image deterioration. Because it will have an adverse effect.

The softening treatment in the intermediate step is intended to reduce the density of point defects and dislocations by this treatment. As a method for softening treatment, for example, electric current softening or tunnel furnace softening is adopted. Unlike the batch method in which crystals are grown slowly and the crystals are coarsened, high-efficiency production is expected by the electric current softening method and tunnel furnace softening method.

As the final treatment step, cold working is performed with a surface reduction rate in the range of 30 to 70% because the wire has a crystal structure extending in a fibrous shape in the length direction. Cold working with a surface reduction rate of less than 30% has little effect on sound and image sharpening, and cold working with a surface reduction rate of more than 70% saturates the effect of sound and image sharpening. The above effect may be impaired due to the defects introduced by, and the flexibility of the conductor is likely to be lost.

The reason why recrystallization is not performed after the softening treatment in the intermediate step is to prevent an increase in the number of grain boundaries that may cross when a current flows in the longitudinal direction of the conductor.

Preferably, the tensile strength of the finally obtained wire is 32 to
It is set to 42 kg / mm ² . If the tensile strength is less than 32 kg / mm ² , the effect of sharpening the sound and image is small, while if the tensile strength exceeds 42 kg / mm ² ,
The conductor may lose its flexibility. further,
In order to improve the connection characteristics as a conductor, the wire after drawing may be electroplated with Ag, Sn, or a material containing these elements as a main component. In addition to the electroplating method, a hot dipping method is also conceivable. However, in the hot dipping method, the crystal structure is disturbed and the effect of sound / image sharpening may be reduced. It can be said that the electroplating method is a preferable method because there is no fear of impairing such effects.

As described above, according to the present invention, it is possible to easily manufacture a conductor that can make the sound and image clear without requiring any special treatment process.

[Example] An oxygen-free copper wire having an oxygen content of 6 ppm was drawn from 8 mmφ to 0.26 mmφ by cold working, and was continuously softened by current conduction in this wiredrawing process and tandem to obtain a soft material. This soft material was cold drawn to a final product size of 0.18 mmφ with a surface reduction rate of 52%. The strand conductor thus obtained was twisted into 7 strands, 19 strands or the like depending on the site to be used to obtain a desired covered electric wire. The conductor thus obtained is the conductor of Sample No. 1 described later.

For comparison, a conductor obtained from normal oxygen-free copper soft material,
The sample number is 5. When the conductor of sample No. 1 and the conductor of sample No. 5 are used as a wiring wire for high-quality video, the conductor of sample No. 1 is replaced with sample No. 5 in terms of image clarity, rich sound quality, and clearness. It was significantly superior to the conductor.

For the purpose of comparison, various intermediate softening sizes, cold workability, etc. were changed in order to manufacture a 0.18 mmφ wire. Including the sample number 1 and the sample number 5 described above, the manufacturing process, the characteristics of the conductor, and the results of the image and acoustic effects are described below.

Sample No. 1 (Example of the present invention) Manufacturing method: 0.18 mmφ after intermediate softening at 0.26 mmφ in the middle
Cold worked up to. The cold workability is 52%.

Tensile strength: 38.9 kg / mm ² Image / sound quality evaluation result: The image was clear. Also, the sound was rich and clear.

 Sample No. 2 (Example of the present invention) Manufacturing method: The conductor of Sample No. 1 was electroplated with Sn.

Tensile strength: 37.2kg / mm ² Image / sound quality evaluation result: The image was clear. The sound was rich and clear.

Sample No. 3 (Example of the present invention) Intermediate softening was performed at 0.3 mmφ and then cold working was performed to 0.18 mmφ. The cold workability is 64%.

Tensile strength: 40.1 kg / mm ² Image / sound quality evaluation result: The image was clear. The sound was rich and clear.

 Sample No. 4 (Example of the present invention) The conductor of Sample No. 3 was heat-treated at 120 ° C. for 1 hr.

Tensile strength: 39.9kg / mm ² Image and sound quality evaluation result: The image was clear. The sound was rich and clear.

Sample No. 5 (conventional example) Manufacturing method: Softened at the final strand wire diameter (0.18 mmφ). The cold workability is 0%.

Tensile strength: 24.0kg / mm ² Image / sound quality evaluation result: Image clarity was poor and sound richness was poor.

Sample No. 6 (Comparative Example) Manufacturing method: After intermediate softening at 2.6 mmφ on the way, it was cold worked to 0.18 mmφ. The cold workability is 99.5%.

Tensile strength: 50.3kg / mm ² Image / sound quality evaluation result: Image clarity was poor and sound richness was poor. Moreover, the conductor lacked flexibility and was difficult to handle.

Sample No. 7 (Comparative Example) Manufacturing method: 0.18 mmφ after intermediate softening at 0.19 mmφ
Cold worked up to. Cold workability is 10%.

Tensile strength: 26.1kg / mm ² Image / sound quality evaluation result: Image clarity was poor and sound richness was poor.

Sample No. 8 (Comparative Example) Manufacturing method: 0.18 mmφ hard material was hot-dip plated with Sn. At this time, the conductor was softened.

Tensile strength: 23.8kg / mm ² Image / sound quality evaluation result: Image clarity was poor and sound richness was poor.

Claims (4)

[Claims] 1. A copper wire having an oxygen content of 30 ppm or less is subjected to a softening treatment in an intermediate step and then subjected to cold working in a final treatment step with a surface reduction ratio of 30 to 70% without recrystallization. A method for manufacturing a conductor for audio / visual equipment, which comprises drawing a wire of a predetermined size according to. 2. The method for manufacturing a conductor for audio / visual equipment according to claim 1, wherein the softening treatment is an electric current softening treatment or a tunnel furnace softening treatment. 3. The tensile strength of the finally obtained wire is 32 to
The method for producing a conductor for audio / visual equipment according to claim 1 or ^2, which has a weight of 42 kg / mm ² . 4. The sound according to any one of claims 1 to 3, wherein after the wire drawing, Ag, Sn, or a material containing these elements as a main component is electroplated. Manufacturing method of conductor for imaging equipment.