JP3152714B2 - Overhead bare wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bare overhead wire, and more particularly, to a bare overhead wire capable of preventing contact corrosion of twisted metal wires.

[0002]

2. Description of the Related Art An aerial bare electric wire is, for example, a metal stranded wire structure of the same material formed by twisting aluminum wires or aluminum alloy wires, or a heterogeneous metal formed by twisting these wires with various metal-coated steel wires. It has a stranded wire structure, and the same kind of metal contact occurring in it,
It is also known that electrochemical corrosion progresses due to the contact between dissimilar metals, which leads to a direct decrease in strength of the wire, or an increase in electrical resistance due to a decrease in cross-sectional area, and the resulting heat generation of the wire. Problems such as softening and reduction in strength have become technical problems to be solved for overhead bare wires.

That is, when there is contact between dissimilar metals such as an aluminum-based metal and an iron-based metal, as in the case of the most common steel core aluminum stranded wire as an overhead power transmission line, sulfur dioxide gas, salt, moisture, etc. in the atmosphere are adsorbed. The resulting battery forms a battery in the presence of the resulting electrolyte, creating a potential difference between the two metals. The fact that the dissimilar metals are in contact in such a state is the same as a short-circuit between the anode and the cathode in a battery, so that current flows during this time. For this reason, the metal on the cathode side constantly loses electrons and is ionized and solutes in the electrolyte. This is the contact corrosion phenomenon between dissimilar metals.

Further, in the case of the same kind of metal, an oxygen concentration cell is formed due to a difference in ventilation, that is, a difference in oxygen supply amount in the presence of the above-mentioned electrolyte existing in the narrow contact gap, thereby causing pitting corrosion (crevice corrosion). ), And if such corrosion progresses gradually, a large amount of corrosion products will be formed inside the electric wire to expand the inside of the electric wire, and this will absorb moisture to further promote corrosion.

Conventionally, as shown in FIG. 3, in order to prevent the above-mentioned electrochemical contact corrosion occurring on an overhead bare electric wire, an anticorrosion compound, which is a synthetic resin in the form of a paste, is placed in the intertwisted gap of the metal strand 1. There is known a technique of filling the base material 101 to prevent formation of a local cell and an oxygen concentration cell between different metals as described above.

[0006]

However, when this anticorrosion compound is used, significant inconveniences occur in connection of electric wires and fixing of terminals at the time of laying electric wires. That is, in order to electrically and securely compress and connect the wire terminals to each other by using a compression-type connection pipe or the like, the above-mentioned compound having strong electric insulation attached around the wires must be completely removed. However, this task is very troublesome,
In addition, there is an inconvenience that this troublesome work must be performed at a construction site of an overhead transmission line having a severe working environment.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an overhead bare electric wire comprising a metal stranded wire formed by twisting a large number of metal wires. This is an overhead bare electric wire in which a metal having a standard electrode potential lower than the metal of the metal wire is interposed between the strands of the wires. The present invention is also the above-mentioned overhead bare electric wire, wherein the metal stranded wires are formed by twisting metal strands of the same material. Furthermore, the present invention is the above-mentioned overhead bare electric wire, wherein the metal stranded wire is formed by twisting metal wires of at least two different materials.

[0008]

When a different kind of metal having a different standard electrode potential comes into contact, the metal having a lower standard electrode potential is electrochemically corroded. Therefore, in the present invention, the metal interposed between the twisted gaps between the metal wires. The metal corrodes, and the contact corrosion of the metal element wire, which is the main conductor of the electric wire, is prevented.

[0009]

FIG. 1 shows an embodiment of the present invention. FIG. 1 shows a typical steel core aluminum stranded wire in an overhead bare wire, in which reference numeral 1 denotes a metal wire made of aluminum or an aluminum alloy, and reference numeral 2 denotes a steel wire 2B coated with zinc plating 2A. This shows a metal element wire of an iron-based material. As is clear from the figure, in the overhead bare electric wire, different types of metal wires 1 and 2 come into contact with each other around the steel core, and the same type of aluminum-based metal wires 1 come into contact with each other at the outer periphery. .

[0010]

[Table 1]

According to the present invention, as is apparent from Table 1 above, for example, magnesium or magnesium alloy intervening metal of a material whose standard electrode potential is lower than aluminum, iron or zinc which is the material of the metal strands 1 and 2 3 is interposed between the twisted gaps of the metal strands 1 and 2. As a specific method of interposing the intervening metal 3, the intervening metal 3 may be twisted together at the time of manufacturing a stranded wire as a wire material or a thin foil material of an appropriate cross section, or before the metal wires 1 and 2 are twisted. An appropriate volatile paint in which the particles of the intervening metal 3 are suspended may be applied and coated over the entire surface.

FIG. 2 shows another embodiment of the present invention. In a gap where the same kind of metal wires 1 are twisted, a material having a standard electrode potential lower than that of aluminum, for example, magnesium, is used. Alternatively, the structure is such that an intervening metal 3 of a magnesium alloy is interposed.

[0013]

Since the present invention has the above-described structure, the intervening metal 3 of a material having a lower standard electrode potential is in contact with the material of the metal strands 1 and 2 constituting the overhead bare electric wire. By taking on the corrosion, there is an effect that the corrosion of the metal wires 1 and 2 which are the main components of the conductivity can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional overhead bare electric wire.

[Explanation of symbols]

 1,2 metal strand 3intervening metal

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01B 5/00-5/16

Claims (3)

(57) [Claims] 1. An overhead bare electric wire comprising a metal stranded wire formed by twisting a large number of metal wires (1, 2), wherein the metal wires (1, 2) are inserted into the twisted gaps between the metal wires. )
A bare overhead electric wire characterized by interposing a metal (3) having a lower standard electrode potential than the metal described in (1). 2. The overhead bare electric wire according to claim 1, wherein the metal stranded wires are formed by twisting metal wires (1) of the same material. 3. The bare overhead wire according to claim 1, wherein the metal stranded wire is formed by twisting metal wires (1, 2) of at least two different materials.