JPH03208208A - Aluminium transmission line and manufacture thereof - Google Patents

Abstract

PURPOSE:To easily manufacture an Al transmission line having low reflectance and low brightness by performing in order a first specific roughest roughening treatment and second roughest roughening treatment on the surface at least of the outermost layer of a transmission line. CONSTITUTION:A grain diameter of abrasives is made, for instance, #60 to 150 in a first stage and a grain diameter of abrasives is made #180 to 320 in a second stage to perform roughening treatment of a transmission line by using blast treatment. Thereby, firstly the roughening treatment of the largest roughness of 15 to 50mum is performed, next the roughening treatment of the largest roughness 3 to 12mum is performed on the outer surface on a stranded wire. In this case, when a grain diameter of abrasives is of roughness not exceeding 60, the surface roughness of the Al transmission line becomes large exceeding 50mum to scrape the surface of the Al transmission line too deep thus to lower the mechanical strength too much. When the grain diameter is reduced exceeding #150, the surface roughness becomes less than 15mum thus to reduce surface treatment in a second stage to make it unable to obtain an expected brightness drop.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an aluminum power transmission line having a color tone that is harmonized with the surrounding environment.

(Prior art) [Problem to be solved by the invention] In recent years, the demand for electricity has increased, and as a result, the size of power transmission lines has increased,
There is a trend toward multiple conductors and multiple lines.

Furthermore, when transmitting power from large-capacity power plants to urban areas, there are increasing cases where power lines must be built through environmentally protected areas such as national or quasi-national parks due to site constraints.

However, if the argonium power transmission lines used in such cases, such as ACSR, are used as they are made in the conventional way, they will not melt into the surrounding environment, and will not melt into the surrounding environment, especially if Al≧Ni has a metallic luster. A problem has arisen in that the surface reflects white and is conspicuous, significantly impairing the good surrounding environment.

In order to solve this problem, the surface of the outermost layer of aluminum power transmission lines is subjected to sandblasting treatment. However, this blasting method reduces the surface reflectance to #. Although it is possible to reduce brightness, it has no effect in terms of brightness, or in fact has a negative effect, so if the background of the power line is a forest with a lot of greenery, the entire power line will appear white, and a satisfactory solution has not been achieved.

Therefore, as another means to solve this problem, it is possible to reduce the brightness by applying a black paint.

However, in the case of power transmission lines, such a method of reducing brightness by painting cannot be immediately adopted.

The reason for this is that it is necessary to attach a large number of accessories such as subasers and armor rods to power transmission lines after the overhead wires are installed, but when painted, an electrically insulating coating is formed, which must be peeled off to separate the wires and accessories. It is necessary to ensure that the potentials are the same, and in addition, when removing the coating film, it is necessary to perform work in the air at a very high altitude, which is difficult to carry out in reality. There is also an idea to make this coating conductive and eliminate the need for stripping, but paints that contain, for example, carbon blank to impart electrical conductivity to the coating accelerate the corrosion of aluminum. In the end, this method could not be put into practical use.

The present invention aims to solve the problems that could not be solved with the conventional techniques.

[Means to solve the problem]

The present invention was made as a result of various studies in view of the above-mentioned circumstances, and it was discovered that by appropriately selecting the conditions for blasting, a surface with low brightness and low reflection can be obtained.

The outline of the present invention consists of the following structure.

■) On the surface of at least the outermost layer of the aluminum transmission line,
Surface roughening treatment with maximum roughness of 15-50 μm and maximum roughness of 3-1
2) An aluminum power transmission line characterized by being sequentially subjected to surface roughening treatment of 2 μm. 2) After blasting the surface of at least the outermost layer of the aluminum power transmission line with an abrasive having a particle size of #60 to 150, A method for producing an aluminum power transmission line characterized by blasting and polishing with an abrasive having a particle size of #180 to #320. Using an abrasive with a particle size of 2
By performing the stepwise blasting process, a power transmission line having a surface condition of low brightness and low reflectance is obtained.

In other words, when blasting is performed with an abrasive of one type of diameter, which is commonly used in the past, even if the blasting is performed with various particle sizes, the effect of reducing reflectance will depend on the particle size. Although it is almost uniformly observed regardless of the brightness, there is almost no or negative effect of reducing the brightness, whereas when the two-step blasting process of the present invention is applied, the brightness decreases as well as the reflectance. It is also effective.

The reason for this is not clear, but it is thought to be due to the formation of fine rough surfaces (irregularities) overlapping the initially large rough surface. In other words, compared to the conventional surface roughened with one type of abrasive, the surface roughened by the present invention is more rough because the direction of the unevenness is influenced by the pre-shaped large roughened surface (irregularities). It is thought that this is caused by a disordered state in complicated directions, which makes the reflection of light more complex and the absorption of light greater, resulting in the effect of lowering brightness.

The abrasive material for blasting used in the present invention may be conventional blasting using corundum, silicon carbide, silica sand, or the like. Further, either a dry method in which the powder is directly sprayed, or a wet method in which the powder is dispersed in water may be used.

In order to obtain a power transmission line with a preferable brightness according to the present invention, the outer surface of the stranded wire is first roughened to a maximum roughness of 15 to 50 μm, and then roughened to a maximum roughness of 3 to 12 μm. I can do it.

The most efficient method to achieve this kind of surface roughness is blasting, in which the particle size of the abrasive is #60 to 150 in the first step, and the second step is to use the abrasive with a grain size of #60 to 150. It has been found that this effect can be achieved by setting the particle size to #I80 to #I320.

In the above, the particle size of the abrasive is #60 to #1 in the first stage.
The reason why it is set to 50 is that the maximum roughness is 15 to 50 μm.
This is because the surface roughness of the aluminum power transmission line can be changed, and if the surface roughness is less than #60, the surface roughness of the aluminum power transmission line will be greater than 50μm, and the surface of the aluminum power transmission line will be cut too deeply, resulting in an excessive decrease in mechanical strength. And #150
This is because if the surface roughness is made smaller than 15 μm, the maximum roughness of the surface will be less than 15 μm, and the roughening effect of the second stage treatment will be small, making it difficult to obtain the expected reduction in brightness. Also,
The reason why #180 to #320 was used in the second stage is that this allows a roughening treatment having a roughening effect with a maximum roughness of 3 to 12 μm to be applied.

〔Example〕

The following experiments were conducted to prove the effects of the present invention.

ACSR of 810 ma2 was prepared with corundum of various particle sizes as an abrasive material, air pressure was 41 g/cm2, and linear velocity was 1 m/m.
1-stage or -F 2-stage blasting treatment under minute conditions. The reflectance and brightness of the processed samples were investigated. The data and details are shown in Table 1, and it can be seen that the lightness reduction effect of the present invention is more remarkable than that of the comparative example, which was subjected to conventional one-stage blasting.

Table 1 Note that in carrying out the present invention, each strand of the electric wire to be treated may be twisted together in advance and then the outermost layer of the strands may be treated, or the strands that become the outermost layer when twisted. After the surface is treated, the wires may be twisted together to form electric wires.

〔Effect of the invention〕

According to the present invention, by combining two appropriate types of surface roughening treatments, it is possible to easily provide an aluminum power transmission line with low reflectivity and low brightness, which has not been achieved in the past.

Claims (1)

[Claims] 1) On the surface of at least the outermost layer of the aluminum power transmission line,
Surface roughening treatment with a maximum roughness of 15 to 50 μm and a maximum roughness of 3 to 50 μm
An aluminum power transmission line characterized by being sequentially subjected to 12 μm roughening treatment. 2) On the surface of at least the outermost layer of the aluminum power transmission line,
A method for manufacturing an aluminum power transmission line, which comprises blasting with an abrasive having a particle size of #60 to 150, and then performing blasting and polishing with an abrasive having a particle size of #180 to 320.