JPS6242421Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to bare electric wires that are suspended in the air and used as power transmission lines, distribution lines, overhead ground wires, support wires, etc., and that prevent snow from accumulating on them. Stranded wires made by twisting multiple metal wires are usually used as these overhead power lines, such as steel-core aluminum stranded wires (hereinafter referred to as ACSR) for power transmission and distribution.
As an example, stranded wires such as those shown in Fig. 1 A and B are used. What is shown in Figure A is a normal ACSR in which hard aluminum (Al) wires 2 are twisted around a steel core with steel wires 1 twisted together. The one shown in Fig. 2 is a compression type ACSR in which a deformed Al wire 3 formed into a ladder shape is twisted around a steel core with steel wires 1 twisted together, or the outer layer of the Al wire is compression molded.
The stranded wire surface is smoothed and the cross-sectional space factor is improved. In such electric wires, the eccentric load of the snow that accumulates on the wires during snowfall causes an eccentric rotational force, causing the snow to rotate around the wires, or the snow and the wires to rotate together, causing the snow to gradually accumulate. The amount of snow increases and develops into large snow pipes, causing accidents such as wire breaks and support collapses. Various proposals have been made in the past to prevent snow buildup, such as attaching rings at regular intervals along the length of the wire, or winding the wire in a spiral in the opposite direction to the twisting direction of the wire. There is a method that aims to have the effect of stopping the snow that has slipped along the twist with a ring or wire, and causing the snow to fall off due to an increase in the eccentric load of the snow itself. However, these measures are not effective depending on weather conditions such as temperature and snow density because the electric wire itself is a metal body and the snow adheres to the metal.
This is not a sufficient countermeasure. This invention was developed as a result of various studies to solve the above-mentioned problems.The outermost surface of the metal body that makes up the electric wire is coated with a material that has less snow adhesion than metal and has good conductivity. By doing so, it is intended to provide a snow-resistant electric wire in which accumulated snow easily falls off the surface of the electric wire and does not develop into a large pile of snow. The present invention involves applying graphite, amorphous carbon, and/or graphite fluoride to the outermost surface of the stranded wire, which is the outermost surface of the stranded wire. This is a snow-resistant electric wire that is characterized by the fact that it consists of: The electric wires covered by this invention are bare electric wires that are used as overhead wires in the air for power transmission lines, distribution lines, overhead ground wires, support wires, etc., and are wires made of aluminum (Al), copper (Cu), or their alloys. , metal wires such as steel wires (inclusive wires), or composite wires such as Al-coated wires and copper-coated wires. Hereinafter, the present invention will be explained with reference to the drawings and examples. FIGS. 2A and 2B and 3A and 3B are cross-sectional views showing embodiments of the present invention, respectively. In the figure, the same reference numerals as in FIG. 1 indicate the same parts. What is shown in Figure 2 A and B is an ACSR similar to Figure 1 A and B, or a compression type ACSR, in which hard Al wires 2' or deformed Al wires 3' constituting the outermost layer are twisted in advance. On the surface, graphite, amorphous carbon and/or graphite fluoride (hereinafter simply referred to as graphite etc.)
4 is firmly applied. What is shown in Figure 3 A and B is an ACSR or compression type ACSR similar to Figure 1 A and B, and after stranding,
The outermost surface is firmly coated with the same graphite material 4 as described above. 2″ and 3″ are the outermost layers, respectively.
Al wire, deformed Al wire. That is, in the electric wire of the present invention, graphite, etc. 4 is coated on at least the surface portion of the metal wire that is the outermost surface of the stranded wire, and graphite, etc. is coated on the surface portion that is the outermost surface of the stranded wire. It may be painted. The graphite, amorphous carbon, and graphite fluoride used in this invention are substances that have lower snow adhesion than metals and have good conductivity, and one or a mixture of two or more of these used. In addition, baking, powder coating, welding, etc. are suitable methods for applying graphite, etc. to the surface of metal wires or stranded wires, and solvents and mixtures that impair the lubricity, conductivity, and stability of the above substances may be used to prevent the finished product. It is necessary to adopt a method that does not leave any residue behind. When applied using this method, the coating film of graphite or the like and the metal body are in close contact with each other, preventing rainwater from entering and preventing them from peeling off. The electric wire constructed as above according to the present invention has the following effects. (b) The contact angle of water is used as an indicator of the adhesion force of snow on substances, but the contact angle of graphite, etc., is much larger than that of metals, as shown in Table 1. , ``Chemical Handbook'' edited by the Chemical Society of Japan).

[Table] It is a well-known fact that graphite, amorphous carbon, and graphite fluoride are all commonly used as solid lubricants and have good lubricity, but their properties are maintained even at relatively low temperatures, and the above-mentioned Combined with its low adhesion, it promotes the shedding of snow. Therefore, as shown in Figures 2 and 3, if the outermost surface of the stranded wire is coated with graphite, etc., the adhesion force of snow to the wire surface is small, and the eccentric load of the snow buildup reduces rotational force. If this is applied, the snow will easily fall off the surface of the wire and will not develop into a large snow pipe, which will effectively prevent snow from accumulating. Therefore, the electric wire of this invention can be used in snowy and cold regions.
Accidents such as disconnection of overhead power lines and collapse of supports due to ice and snow can be prevented. (b) Also, in power transmission lines and insulated cables, the limit conductivity that does not cause partial discharge in a semiconducting layer applied to a conductor is set at a volume resistivity of 10 ⁶ Ω-cm. Table 2 shows the volume resistivity of graphite, etc. used in this invention.
As shown in , the conductivity is much better than the above value (see Iwanami Shoten's ``Physical and Chemistry Dictionary'' and ``New Fluorine Chemistry'' edited by the Chemical Society of Japan).

[Table] Therefore, since the surface of the electric wire of the present invention is conductive, it can exhibit snow-repellent effects without impairing the electrical function of conventional power transmission lines. (c) Next, as shown by the fact that amorphous carbon is used to prevent UV deterioration of polyethylene, etc., graphite and amorphous carbon do not deteriorate even in harsh environments, and graphite fluoride It has been reported that it is very stable thermally and chemically. Therefore, graphite and the like are chemically stable and have an anticorrosion effect, so they are expected to have a long life. Furthermore, as mentioned above, graphite and the like have good lubricity and a small amount of abrasion, so not only is there less abrasion during overhead contact lines, but there is also less wear due to rain, ice and snow, and in this respect, a long service life can be expected. It should be noted that a synergistic effect can be expected by combining the anti-snow accretion electric wire according to the present invention with anti-snow measures for conventional bare electric wires and plastic insulated electric wires. For example, when combined with the measures proposed for conventional bare electric wires, examples are shown in FIGS. 4 to 6. 4A and 4B are rings 6, 6, etc. attached at intervals in the length direction of the electric wire 5 according to the present invention shown in FIG. What is shown is that two electric wires 7, 7' according to the present invention similar to those shown in FIG. They are connected by split type hangers 8, 8... Numeral 9 is a bolt for tightening the two halves of the hanger 8 together. With the configuration shown in Figures 4 and 5, if snow falls on the electric wire 5 or 7, 7', graphite etc. on the surface of the electric wire 4
Due to the eccentric load, the snow easily slides along the strands and stops at the ring 6 or the hanger 8, and since the adhesion of the snow is small, it easily falls off while the snow is small, so snow accretion is more effectively prevented. It has a synergistic effect and can supplement the insufficient effects of conventional methods. In addition, in the case of two rows as shown in Fig. 5, it is expected that rotating snow will stop between the two rows. In addition, in the case shown in FIG. 6A and B, two electric wires 7 and 7' of the present invention, which are similar to those shown in FIG.
0 spirally wound. In this case as well, the snow on the wires 7 and 7' easily slides along the strands and stops at the bind wire 10 or the contact point between the two wires, and since the adhesion force of the snow is small, the snow can easily slide while the snow is small. This has a synergistic effect that more effectively prevents snow from accumulating. The electric wire of the present invention can also be combined with measures to prevent snow from accumulating on conventional plastic insulated electric wires, such as adding protrusions such as fins to the surface. Since the snow does not rotate and the adhesion of the snow is small due to the graphite on the surface, the snow falls off easily while the snow is small, so there is a synergistic effect of more effectively preventing snow from accumulating. In this way, by combining the coating of graphite or the like according to the present invention with the conventional snow rotation prevention measures, a synergistic effect can be obtained in which snow that has stopped rotating can be easily removed while it is still small. In the above explanation, the present invention was mainly explained using ACSR as an example, but the present invention is equally applicable to electric wires other than ACSR, such as hard copper stranded wire, hard aluminum stranded wire, Al-coated steel stranded wire, etc. It can be applied to

[Brief explanation of the drawing]

FIGS. 1A and 1B are cross-sectional views showing examples of a conventional ACSR and a compression type ACSR, respectively. FIGS. 2A and 2B and 3A and 3B are cross-sectional views showing embodiments of the present invention, respectively. Figures 4 to 6 are views showing other embodiments of the present invention, in which Figure A is a side view and Figure B is a cross-sectional view. 1... Steel wire, 2, 2', 2''... Hard aluminum wire, 3, 3', 3''... Deformed Al wire, 4... Graphite,
Amorphous carbon and/or graphite fluoride (graphite, etc.),
5, 7, 7'...Electric wire, 6...Ring, 8...Hanger, 9...Bolt, 10...Binding wire.

Claims (1)

[Claims for Utility Model Registration] (1) In a stranded wire made by twisting a plurality of metal strands, graphite, amorphous carbon and/or A snow-resistant electric wire characterized by being coated with graphite fluoride. (2) The anti-snow accretion type according to claim 1 of the utility model registration claim, in which graphite, amorphous carbon, and/or graphite fluoride is applied to the surface of the metal wire for the outermost layer before twisting. Electrical wire. (3) The snow-resistant electric wire according to claim 1, wherein graphite, amorphous carbon, and/or graphite fluoride is coated on the outer surface of the twisted wire. (4) Utility model registration claim No. 1 in which the stranded wire has rings attached at intervals in the longitudinal direction.
The snow-resistant electric wire according to item 2, item 2, or item 3. (5) The stranded wire is formed by connecting two stranded wires arranged parallel to each other with an interval in the length direction using a hanger. The snow-resistant electric wire described in item 2 or 3. (6) Utility model registration claims Paragraph 1, Paragraph 2, or Paragraph 3, in which the stranded wire consists of two stranded wires arranged vertically and a binding wire wound spirally around the outside of the stranded wire. The listed snow-resistant electric wire.