JPS60125359A - Production of conductor for image display apparatus and acoustic apparatus - Google Patents

Abstract

PURPOSE:To produce the titled conductor in which signal current flows exactly without generating a phase difference by casting or hot working an oxygen-free steel then subjecting the steel to a heat treatment under specific conditions. CONSTITUTION:An oxygen-free steel is cast or hot worked and is then heat- treated by heating and holding the steel in the temp. range where the crystal does not crystallize again and at >=500 deg.C temp. The heat treatment is accomplished by stopping cooling at a prescribed temp. of >=500 deg.C and holding the steel at said temp. or cooling slowly the steel at a cooling rate of <=100 deg.C/hr in a prescribed temp. range of >=500 deg.C in the cooling stage of the casting ingot after casting or the cooling stage of the blank material after hot working in the case of performing the heat treatment in continuation with casting or hot working. The casting of the oxygen-free steel is accomplished by a dip forming method.

Description

Detailed Description of the Invention (Technical Field) The present invention is applicable to, for example, TV, VTR, CRT (Cat
The present invention relates to a method for manufacturing conductors used in wiring of electronic devices that require signal transmission circuits, such as hodRay tubes (braun tubes) and audio equipment.

(Background Art) In these electronic devices, if signals are not transmitted accurately without creating a phase difference, the image or sound may become blurred or the sound may not be clear.

Conventionally, annealed copper wires are produced by cold-working tough-pitch copper (pure copper containing about 200 to 500 PPm of oxygen) or oxygen-free copper (pure copper containing almost no oxygen) by annealing, softening, and recrystallizing them, or sometimes leaving them cold-worked. Hard copper wires or wires plated with tin or the like have been used for these purposes.

However, these lines are not always convenient for accurate signal transmission for the following reasons.

In the case of annealed copper wire, the crystal grains are usually distributed in a nearly equiaxed shape due to recrystallization due to annealing, so when a current flows in the longitudinal direction of the conductor, the number of grain boundaries that will be crossed increases. It is thought that this is particularly important for high-frequency component signals as a cause of phase difference generation.

In the case of hard copper wire, compared to annealed copper wire, it has a fibrous crystal shape that extends in the longitudinal direction, so when a current flows in the longitudinal direction, the number of grain boundaries that would be crossed is apparently one less. Than,
Although it is less susceptible to the negative effects of grain boundaries, atomic vacancies (point defects)
, the density of dislocations (linear crystal defects) is higher than that of annealed copper wire.
It is thought that there is an extremely large amount of it and that it becomes electricity.

(Disclosure of the Invention) The present invention has been made to solve the above-mentioned problems, and is an image display device and an audio device in which a signal current flows accurately through a conductor without a phase difference, and image and sound are clear. The purpose of this invention is to provide a method for manufacturing a conductor for use.

The present invention provides an image display device and an audio device, characterized in that after casting or hot working oxygen-free copper, heat treatment is performed in which crystals are not recrystallized and maintained at a temperature of 500° C. or higher. This is a method for manufacturing conductors for use in

Conductors to which the present invention is applied include, for example, TVs and VTRs.

A conductor used for wiring image display devices such as CRTs or audio devices such as stereos, but is not limited to high-frequency signal transmission circuits, and is a single wire that is plated with tin, solder, etc. It is used in the form of a single wire or a stranded wire made by twisting multiple wires together.

The cross-sectional shape of the conductor may be circular, oval, square, or other irregular shapes.

The reason why oxygen-free copper is used as a raw material in the present invention is to prevent oxygen and impurity elements or compounds having semiconductor characteristics of oxygen and copper from being distributed in the conductor.

Hereinafter, the present invention will be explained by examples using the drawings. The figure is a diagram showing the manufacturing process of a typical embodiment of the method of the present invention. In the figure, special heat treatment according to the present invention is performed after hot rolling. Further, this heat treatment may be performed after other hot processing (eg, extrusion, swaging, wire drawing, etc.) or casting (eg, continuous casting, dip forming, chill mold casting, etc.).

This special heat treatment is performed within a temperature range where crystals do not recrystallize.
It is carried out by heating and maintaining at a temperature range of 500° C. or higher. In addition, when performing continuous casting or hot working, cooling at a predetermined temperature of 500°C or higher is performed during the cooling process of the ingot after casting or during the cooling process of the material after hot working. stop and
by holding at that temperature or 500℃
This is carried out by slowly cooling the above predetermined temperature range at a cooling rate of 100° C. or less. When the cooling rate exceeds 100°C/hour, there is insufficient time for the temperature to reach the desired temperature of 500°C or higher. By performing the heating continuously in this way, the energy required for reheating is omitted, which is economical.

If the heat treatment temperature is less than 500° C., it takes a long time to obtain the desired clear images and sounds, which may be industrially inappropriate or insufficiently effective.

Further, at the temperature at which recrystallization occurs, impurities are likely to form a solid solution, resulting in a clear external surface.

Although the mechanism of the special heat treatment in the present invention is not clear, the presence of industrially produced oxygen-free copper and the unavoidably contained impurities changes so that it is less likely to cause irregularity in the electron distribution within the conductor. Therefore, it is thought that the phase of the high-frequency signal current becomes difficult to shift. As a result, when a high-frequency signal current flows through the conductor after final processing, it flows accurately without phase difference, resulting in clear images and sounds. The reason for carrying out this heat treatment after casting or hot working is that if the degree of cold working is large, heating to 500°C or higher will cause recrystallization, coarsening the crystal grains, and impairing the mechanical properties of the conductor. In general, high-temperature heating may lead to surface oxidation.If the product size is close to that of the product, peeling or pickling is not industrially advantageous.

In the method of the present invention, after the above-mentioned special heat treatment, cold processing, peeling if necessary, intermediate softening,
Twisted wire is applied.

Further, finish softening may be performed at the final wire diameter or at the wire twisting stage.

(Example 1) Using electrolytic copper as a raw material, an oxygen-free copper lid was formed by a dip forming method, which was then hot-rolled into a 9.5 mm# wire rod, and then heat-treated at 550° C. for 12 hours. There was no change in crystal grains due to this heat treatment.

The surface of this wire was stripped and cold wire drawn to 1.6 mm*, then intermediate softening was performed at aOO℃ for 2 hours in a non-oxidizing atmosphere, and then cold wire drawn to 0.12 mm. .

This wire is passed through a tunnel furnace in a non-oxidizing atmosphere maintained at a temperature of 400°C to form an annealed copper wire, and these 19 wires are twisted to form a stranded wire, which is then braided to form a shield type electric wire (
tJnl) was created.

For comparison, a comparative example electric wire (No. 2) was prepared without the above-mentioned heat treatment after hot rolling and other conditions were kept the same, and a conventional example electric wire (No. 2) using tough pitch copper wire made by the conventional method was prepared. No. 3) was prepared.

The obtained electric wire was used as an electric wire for a speaker, and the acoustic evaluation results are shown in Table 1.

Table 1 From Table 1, it can be seen that the sound according to the present invention is clearer and has no distortion compared to the comparative example and the conventional example.

(Example 2) After hot extrusion, an oxygen-free copper billet was heat-treated under the conditions shown in Table 2, peeled, and then cold-drawn into a wire of 0.18 mm. Eleven of the softened wires were The wires were twisted together to form twisted wires and coated with insulation to create a cord.

Use this cord as the TV's power cord to control the TV's sound.
The results of evaluating the images are shown in Table 2.

Table 2 From Table 2, it can be seen that the sound and image of the samples according to the present invention are clearer than those of the comparative example.

(Effects of the Invention) The conductor for image display equipment and audio equipment of the present invention constructed as described above has the following effects.

(a) After casting or hot working, oxygen-free copper is heat-treated to be heated and held at a temperature range of 500°C or higher in which crystals do not recrystallize, so impurities are inevitably contained due to heat treatment. changes in a manner that does not cause irregularities in the electron distribution within the conductor, so image and sound signal currents flow accurately without phase difference, making it possible to manufacture a conductor with clear images and sound.

(b) The raw material may be ordinary electrolytic copper, and the manufacturing process only requires adding a heat treatment step to the conventional method, so it can be manufactured industrially easily and at low cost.

[Brief explanation of drawings]

The figure is a diagram showing the manufacturing process of a typical embodiment of the method of the present invention.

Claims (3)

[Claims] (1) An image display device characterized in that after casting or hot working oxygen-free copper, heat treatment is performed by heating and holding the oxygen-free copper in a temperature range in which crystals do not recrystallize and in a temperature range of 500°C or higher;
A method for manufacturing conductors for audio equipment. (2) Heat treatment is carried out by stopping cooling at a predetermined temperature of 500°C or higher and holding it at that temperature during the cooling process of the ingot after casting or the cooling process of the material after hot working. 2. A method for manufacturing a conductor for an image display device or an audio device according to claim 1, which is carried out by slowly cooling a predetermined temperature range of 500° C. or higher at a cooling rate of 100° C./hour or lower. (3) A method for manufacturing a conductor for an image display device or an audio device according to claim 1 or 2, wherein the casting is performed by a dip forming method.