JPH11176241A - Overhead electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide both excellent lubricating property and corona noise suppressing property by forming a hydrophilic coating on the surface of an aluminum stranded wire and forming a lubricating layer from an aqueous soln. containing a surfactant with a specified surface tensile further on the hydrophilic coating. SOLUTION: The surface of a stranded wire produced by stranding a plurality of aluminum wires is made to hydrophilic and coated with hydrophilic coating. A lubricating layer containing a surfactant is formed on the hydrophilic coating. A surfactant having surface tension of 50 dyne/cm or higher in a 0.01 wt.% aqueous solution is selected. The thickness of the hydrophilic coating is controlled to be about 0.1-10 μm. Due to formation of the hydrophilic coating, even if water adheres, water spreads on the hydrophilic coating while forming a water film without becoming dew drops and corona noise generation can be prevented. The hydrophilicity treatment is preferably carried out by roughening the surface of the stranded wire by blast treatment and boehmite treatment for forming boehmite by bringing the resultant stranded wire into contact with high temperature steam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when used in overhead transmission lines, has good corona noise characteristics during rainfall,
In addition, the present invention relates to an overhead electric wire that does not cause troubles such as damage or return of twist (called "laughing") at the time of manufacturing or overhead wire.

[0002]

2. Description of the Related Art Conventionally, as a transmission line having good corona noise characteristics, a stranded wire such as a steel core aluminum stranded wire (ACSR) is subjected to a hydrophilic treatment such as a blast treatment or a boehmite treatment, and the surface of the stranded wire is subjected to a hydrophilic treatment. What has formed the chemical conversion film is known. This method has the advantage of generating less corona noise due to corona discharge because water droplets are formed on the transmission line surface during rainfall.On the other hand, oil such as mineral oil can be applied to the surface of the stranded wire. Because of the lack of lubrication, the lubricating properties were insufficient, and there were inconveniences such as scratching during manufacturing and overhead wire, turning or squeezing when passing through a wheel while the overhead wire, and causing laughter.

[0003] For this reason, in order to prevent corona noise characteristics from being good and to prevent problems such as laughter during overhead lines,
A coating in which a surfactant is applied to a hydrophilic film on the surface of a stranded wire has been proposed (see Japanese Patent Publication No. 57-46165 and Japanese Patent Publication No. 58-37924). In this case, a certain degree of lubricity is imparted by the surfactant layer, and the above-mentioned inconveniences at the time of manufacturing and overhead wire are solved, but immediately after the overhead wire, a large amount of water droplets are formed due to the presence of the surfactant layer, and corona noise is generated. The applied surfactant is gradually washed away by rainfall after the overhead wire, and the corona noise gradually decreases.

[0004] Therefore, in such a transmission line,
Unless about six months or more have passed since the overhead wire operation and the surfactant was almost washed out, there was a disadvantage that power could be applied and the service could not be performed. However, in recent years, the number of devices to which power is applied and used immediately after completion of overhead wire work such as replacement of existing transmission lines is increasing, and the above-mentioned prior art has a drawback that such a demand cannot be satisfied.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide good corona noise characteristics immediately after an overhead transmission line or the like when used as an overhead power transmission line, and have sufficient lubricating properties at the time of manufacturing and overhead wiring. An object of the present invention is to provide an overhead electric wire free from defects such as scratches and laughter.

[0006]

The object of the present invention is to provide a lubricating layer comprising a surfactant having a surface tension of not less than 50 dynes / cm in a 0.01% by weight aqueous solution on a hydrophilic film formed on a stranded wire. Can be solved. The lubricating layer may be a layer to which lubricating oil such as mineral oil is added.
According to this, the initial lubricity is further enhanced, and scratches and laughter can be almost completely prevented.

[0007]

The above surfactant has a large surface tension and is close to that of water. For this reason, even if there is adhesion of water due to rainfall, the formation of water droplets is weak and corona noise is low. Therefore, the corona noise is low from the beginning of the overhead wire without waiting for the time when the surfactant is completely washed away by rainfall.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
As the aluminum wire used in the present invention, a normal hard aluminum wire, a high-strength aluminum wire, a No. aluminum alloy wire, a heat-resistant aluminum alloy wire, an aluminum-coated steel wire, or the like is used. In addition, a stranded wire composed of these aluminum wires is a stranded wire obtained by twisting a plurality of these wires, or a steel core stranded wire (ACSR, IACSR) obtained by twisting a single wire or a stranded wire of galvanized steel wire as a steel core. Are used.

[0009] A hydrophilized film is formed on the surface of the stranded wire. This hydrophilized film is formed by applying a hydrophilizing treatment to the surface of the stranded wire, and is a type of oxide film in which the surface layer on the surface is oxidized. As the hydrophilization treatment, any of the conventionally used hydrophilization treatments for aluminum can be applied. Particularly preferred here is that the surface of the stranded wire is first blasted to roughen it, There is a boehmite treatment for generating boehmite by contacting with steam.

[0010] The thickness of the hydrophilic film is about 0.1 to 10
It is about μm. Due to the formation of the hydrophilic film, even if water adheres to the film, it does not become water droplets, but becomes a water film and spreads on the hydrophilic film, thereby preventing the generation of corona noise.

A lubricating layer made of a surfactant is provided on the hydrophilized film. The surfactants here include:
An aqueous solution having a large surface tension is used.
Those having a surface tension of 50 dynes / cm or more in a 01% by weight aqueous solution are selected. The surface tension here is JIS
It refers to the value measured by the ring method specified in K3326.

The surface tension of an aqueous solution of a surfactant varies depending on the type and concentration of the surfactant, but most of the surfactants usually used as detergents have a low surface tension. Most have a surface tension of 40 dynes / cm or less in a weight% aqueous solution. The surfactant may be of any type such as anionic type, cationic type, nonionic type and amphoteric type. In short, the surface tension of a 0.01% by weight aqueous solution is 50 dynes / cm.
Any of the above can be used.

Specific examples of the surfactant used in the present invention include, for example, alkylbenzenesulfonate (manufactured by Nippon Oil Chemical Laboratory) and alkylamino acid type surfactant (manufactured by Nippon Oil Co., Ltd.). Oil Chemicals Laboratory), polyoxyethylene sorbitan monooleate (trade name, Reodol TW-0106, manufactured by Kao Corporation) and the like. The surfactant contains 0.01% by weight.
One kind or a mixture of two or more kinds having a surface tension of 50 dynes / cm or more in an aqueous solution may be used, and the surface tension of a 0.01% by weight aqueous solution of the mixture may be 50 dynes / cm or more. You may.

This surfactant is used as it is or dissolved in a solvent for dissolving it, for example, alcohols or water, and if necessary, a solution containing an antifoaming agent is applied onto the above-mentioned hydrophilized film. Then, by drying, a lubricating layer having a thickness of 0.1 to 30 μm is obtained. This lubricating layer is formed not only on the surface of each strand of aluminum strands exposed on the strand, but also on the strand surface inside the fine twist gap, to improve the slipperiness between strands. Become.

[0015] In such an overhead electric wire, since the lubricating layer is provided on the outermost layer, no trouble such as scratching or laughter occurs in the electric wire during manufacturing or overhead wire. In addition, since the lubricating layer is made of a surfactant having a large surface tension and close to the surface tension of water, the lubricating layer itself has good water wettability, and it is difficult for water droplets to be formed even when it rains.
For this reason, even if power is applied immediately after the overhead line, the occurrence of corona noise is slight.

Furthermore, even if the lubricating layer is gradually washed away by rainfall, good corona noise characteristics are maintained by the inner hydrophilic film. In addition, deposits such as oil stains inevitably adhering to the electric wires during manufacturing, storage and transportation, or overhead lines are also removed with the loss of the lubricating layer, so that it is possible to prevent a decrease in corona noise characteristics due to these deposits.

In the present invention, when providing a lubricating layer,
A lubricating oil such as liquid paraffin or mineral oil may be added to the surfactant or a solution thereof in an amount of about 1 to 50% by dry weight to apply the lubricating oil, whereby the initial lubricity is improved. In addition, the workability at the time of the overhead wire is improved, the occurrence of laughter and scratches is further suppressed, and since these lubricating oils flow away together with the surfactant which is the main component of the lubricating layer, the corona noise characteristics are not reduced.

Hereinafter, specific examples will be shown to clarify the operation and effect. (Experimental example 1) A steel core aluminum stranded wire (ACSR) having a conductor cross-sectional area of 810 mm ² was used as an electric wire, and this was subjected to blast treatment and boehmite treatment to form a hydrophilized film having a thickness of about 0.5 µm. A 20% by weight ethanol solution of various surfactants shown in Table 1 was applied to the electric wire having the hydrophilized film and dried to provide a lubricating layer having a thickness of 10 μm, thereby obtaining an overhead electric wire. Table 1 shows the surface tension of the used surfactant in a 0.01% by weight aqueous solution.

The surfactants A to E in Table 1 are as follows. Surfactant A: alkylbenzene sulfonate (anionic surfactant) Surfactant B: alkylamino acid type surfactant (amphoteric surfactant) Surfactant C: polyoxyethylene sorbitan monooleate ("Leodor TW-0106") Surfactant D: polyoxyethylene derivative ("Emulgen A-60") manufactured by Kao Surfactant E: polyoxyethylene ether ("Emulgen 420") manufactured by Kao

The corona noise characteristics and lubrication characteristics of these overhead electric wires were evaluated, and the results are shown in Table 1. The corona noise characteristics were evaluated by applying a voltage corresponding to a maximum surface potential gradient (Gmax) of 13 to 17 kV / mm in the corona cage, and evaluating the noise level during equivalent light rain. The lubricating property was evaluated by performing a wheel running test and evaluating the change in the outer diameter of the electric wire, the presence or absence of laughter, and the degree thereof.

For comparison, Table 1 also shows the results of similar evaluations of those without a lubricating layer and those coated with ethylene glycol and glycerin instead of the surfactant.

[0022]

[Table 1]

FIGS. 1 and 2 are graphs showing specific numerical values of the corona noise characteristic in the above-mentioned experimental example. The horizontal axis represents the maximum surface potential gradient, and the vertical axis represents the random sound in FIG. In FIG. 2, the level was measured by taking the corona hum sound level and changing the type of the lubricating layer. From Table 1 and FIGS. 1 and 2, 0.01% of the surfactant
It is clear that those having a surface tension of 50 dynes / cm or more in a weight% aqueous solution can achieve both lubricity and corona noise characteristics.

(Experimental Example 2) Alkylbenzenesulfonate 3% by weight Alkylamino acid type amphoteric surfactant 9% by weight Dimethyl silicone polymer (antifoaming agent) 1% by weight Methanol 22% by weight Water 65% by weight mixed solution (“Rue” The same test as in Experimental Example 1 was performed using “Bright # 396-V2” (trade name, manufactured by Japan Oil Chemicals Laboratory). This mixed solution was diluted 1000 times with water, but had a surface tension of 58 dynes / cm. The test results showed that the corona noise characteristics and the lubricity were equivalent to those obtained with surfactant B in Table 1.

(Experimental Example 3) Liquid paraffin was added to the mixed solution used in Experimental Example 2 at a volume ratio of 90:10, and the same test as in Experimental Example 1 was performed using a well mixed solution. Good corona noise characteristics and lubrication characteristics were obtained. The paraffin-added solution was diluted 1000-fold with water and had a surface tension of 58 dynes / cm.

[0026]

As described above, the overhead electric wire of the present invention is provided with a lubricating layer made of a specific surfactant on a hydrophilic film formed on the surface of the stranded wire. The layer provides both good lubrication and corona noise characteristics. For this reason, inconveniences such as scratches and laughter do not occur at the time of manufacturing and at the time of the overhead wire, and good corona noise characteristics are exhibited immediately after the overhead wire.

[Brief description of the drawings]

FIG. 1 is a chart showing the results of an experimental example.

FIG. 2 is a table showing the results of an experimental example.

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[Procedure amendment]

[Submission date] January 27, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

The surfactants A to E in Table 1 are as follows. Surfactant A ... alkylbenzene sulphonate (anionic surfactant) surfactant B ... alkylamino acid type active agent (amphoteric surfactant) surfactant C ... polyoxyethylene sorbitan monooleate ( "Les odo Lumpur TW- 0106 "manufactured by Kao) surfactant D ... polyoxyethylene derivative (" Emulgen A-60 "manufactured by Kao Corporation) surfactant E ... polyoxyethylene ether (" Emulgen 420 "manufactured by Kao Corporation)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

(Experimental Example 2) Alkylbenzenesulfonate 3% by weight Alkylamino acid type amphoteric surfactant 9% by weight Dimethyl silicone polymer (antifoaming agent) 1% by weight Methanol 22% by weight Water 65% by weight mixed solution (“Rue” The same test as in Experimental Example 1 was performed using “Bright # 396-V2” (trade name, manufactured by Japan Oil Chemicals Laboratory). This mixed solution was diluted 1000 times with water, but had a surface tension of 58 dynes / cm. The test results, corona noise characteristic and lubricating characteristics were comparable to those obtained with surfactant B of Table 1.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Koichi Saruwatari 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Masatake Maejima 1-1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura

Claims (2)

[Claims] 1. A hydrophilic film is formed on the surface of a stranded wire obtained by twisting aluminum wires, and a surface tension of a 0.01% by weight aqueous solution is 50 dynes / cm or more on the hydrophilic film. An overhead electric wire provided with a lubricating layer comprising a surfactant. 2. The overhead electric wire according to claim 1, wherein said lubricating layer contains lubricating oil.