JPH0462723A - Manufacture of low brightness electric wire - Google Patents

Abstract

PURPOSE:To obtain a low brightness electric wire that has a low reflection rate and hardly generates a corona noise, by boiling an aluminum wire or plural aluminum wires or a stranded wire intertwisted with a reinforcement wire in a solution containing iron ion or the solution added with hydrogen peroxide water. CONSTITUTION:To make the surface less bright in a short time and on top of it, to make post-treatment water washing unnecessary are realized by boiling an aluminum wire or plural aluminum wires or a stranded wire intertwisted with a reinforcement wire in a solution containing iron ion. Also, A treatment time can be further shortened by boiling the above in the iron ion containing solution that is added with hydrogen peroxide water. Moreover, in the case the surface of the aluminum wire or the stranded wire is conducted with abra sive blasting treatment beforehand, the treatment time by means of the above solution can be shortened further. As a result, a low brightness electric wire that has a low reflection rate and hardly generates a corona noise can be manu factured by means of a simple device and also in a short treatment time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing a low-brightness electric wire that has low reflection and generates little corona noise.

(Prior technology) Overhead power transmission lines that pass through environmentally protected areas such as national parks have traditionally been shot-blasted to make them glossy and to reduce the reflection of the surface, in order to avoid damaging the beauty of the environment. Low-reflection wires with a low reflection rate and colored wires with colored paint coated on the surface of the wires are used.

In areas where corona noise is a problem, so-called AN (audible corona) reduction wires are used, which are made by boiling the wires in deionized water or exposing them to a steam atmosphere to form a boehmite layer on the surface.

Recently, however, in addition to these characteristics (low reflection, reduced AN), there has been a demand for overhead power transmission lines that have blackened wire surfaces to reduce brightness.

Methods for reducing the brightness include (1) forming an alumite layer on the surface of the wire by alumite treatment, and then impregnating this layer with black dyes, pigments, etc.; (2) using black metals such as molybdenum and manganese; Methods such as chemically plating the surface of the wire, and (c) applying black colored paint are known methods.

(Problem to be solved by the invention) However, among these methods, method (a) cannot perform alumite treatment on electric wires having steel wires such as AC8R wires (steel core aluminum stranded wires). Therefore, it has to be processed at the strand stage, which requires a large amount of equipment costs such as multiple water-sprinkling equipment and electrolysis equipment, and also requires a processing time of 30 minutes or more when pre-treatment and water washing are included. There is a difficulty in doing so.

In addition, with method (2), it is virtually impossible to completely wash away the treatment liquid that has entered the inside of the wire, and there is a risk that the remaining treatment liquid may corrode the aluminum wire or steel wire. If processing is attempted at the strand stage, problems will arise in terms of equipment costs and processing time, similar to method (a).

Furthermore, in method (c), the paint partially peels off due to aging, which causes corona generation.

The present invention has been made in response to these conventional circumstances, and provides a method for manufacturing low-brightness electric wires with low reflectance and less risk of corona noise generation using simple manufacturing equipment and in a short processing time. The purpose is to

[Structure of the Invention (Means for Solving the Problems) The method for manufacturing a low-brightness electric wire of the present invention is to produce an aluminum wire or a stranded wire made by twisting a plurality of aluminum wires alone or together with a reinforcing wire. It is characterized by boiling treatment with an aqueous solution containing ions or a solution obtained by adding hydrogen peroxide to the aqueous solution containing iron ions.

The aluminum wire in the present invention is not limited to pure aluminum wire, but may be any of various aluminum alloy wires commonly used as wire materials.

In addition to steel wire, examples of the reinforcing wire include wire rods made of glass fiber reinforced plastic or carbon fiber reinforced plastic.

In the present invention, the aqueous solution containing iron ions preferably has an iron ion concentration of about 0.1 to 10 PPM.

Further, when hydrogen peroxide is further added to such an aqueous solution containing iron ions, it is desirable to add, for example, 35% hydrogen peroxide in an amount of 2 to 15 ml per gram of the solution. This is because if it is less than 2 ml, the effect of shortening the processing time by adding hydrogen peroxide solution is small, and conversely, if it exceeds 15 ml, the effect does not change much.

The treatment time with such a solution may be determined as appropriate to obtain the desired brightness depending on the concentration of iron ions and hydrogen peroxide solution. A processing time of approximately 15 minutes is sufficient to obtain the Munsell value.

In the present invention, it is more desirable to perform blasting treatment on the surface of the aluminum wire or its strands in advance, thereby further shortening the treatment time.

(Function) In the method for manufacturing a low brightness electric wire of the present invention, an aluminum wire,
Alternatively, by boiling a stranded wire made by twisting multiple aluminum wires alone or together with reinforcing wire in an aqueous solution containing iron ions, the surface brightness can be reduced in a short time, and the surface can be washed with water after treatment. There is no need for such things.

Furthermore, the treatment time can be further shortened by boiling in an aqueous solution containing iron ions to which hydrogen peroxide has been added.

Furthermore, when the surface of the aluminum wire or its strands is subjected to blasting treatment in advance, the treatment time with the aqueous solution can be further shortened.

(Example) Examples of the present invention will be described below.

Example AC3R wire with a cross-sectional area of 810Illj taken from a drum,
An aqueous solution with an iron ion concentration of IPPM, or a 35% hydrogen peroxide solution to this aqueous solution, 2.5.10% per 1 g of solution.
5.10.15.20.After immersing in a treatment tank containing a treatment liquid added to contain 115ml, adjusting the linear velocity for each treatment liquid, and boiling for 25 minutes,
Low brightness electric wires were continuously produced by air drying.

When the brightness (Munsell value) of the low brightness electric wire thus obtained was measured, the results shown in the graph of FIG. 1 were obtained.

Furthermore, when we measured the surface reflectance of these low-brightness wires with a Munsell value of N4.5 or lower, all of them showed low values of 30% or less, and they also had good water drainage, which indicates the effect of reducing corona noise. there were.

Next, an AC3R wire having the same cross-sectional area as above of 810- is continuously passed through a blasting machine to blast the surface, and then similarly boiled in a treatment solution containing iron ions, etc.
It was dried to produce a low brightness electric wire. The treatment liquid used was an aqueous solution with an iron ion concentration of IPPM, and a 35% hydrogen peroxide solution added to this aqueous solution so that it contained 5 ml per 1 g of solution, and the treatment time was 5.10.
．． The duration was 15 minutes.

The lightness (Munsell value) of the low-brightness electric wire thus obtained was also measured in the same manner. The results are as shown in the graph of FIG. 2, and the effect of shortening the processing time by blasting was recognized.

[Effects of the Invention] As is clear from the above examples, according to the method of the present invention, a low-brightness electric wire with low reflectance and less risk of generating corona noise can be manufactured using a simple device and in a short processing time. be able to.

Furthermore, when the present invention is applied to a stranded wire type having steel wires such as AC8R wire, the brightness can be reduced without any problem even if the treatment is performed after the strands are twisted, rather than at the stage of the strands, and the lightness can be reduced without any problem. Unlike conventional methods, problems such as equipment costs and long processing times do not arise.

[Brief explanation of drawings]

FIGS. 1 and 2 are graphs showing the brightness of a low-brightness electric wire obtained by an example of the method of the present invention, together with the type of treatment liquid used and the treatment time. Applicant Showa Electric Cable Co., Ltd.

Claims (4)

[Claims] (1) A method for producing a low-brightness electric wire, which comprises boiling an aluminum wire or a stranded wire formed by twisting a plurality of aluminum wires alone or together with a reinforcing wire in an aqueous solution containing iron ions. (2) The method for manufacturing a low-brightness electric wire according to claim 1, characterized in that a hydrogen peroxide solution is further added to the aqueous solution containing iron ions. (3) The method according to claim 1, characterized in that the surface of the aluminum wire or the stranded wire formed by twisting a plurality of aluminum wires alone or together with a reinforcing wire is blasted in advance. Method of manufacturing electric wire. (4) The method according to claim 2, characterized in that the surface of the aluminum wire or the stranded wire formed by twisting a plurality of aluminum wires alone or together with a reinforcing wire is blasted in advance. Method of manufacturing electric wire.