JPH043364Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a composite overhead wire such as an overhead ground wire and an overhead power transmission line, which is equipped with an optical transmission function.

Conventionally, this type of overhead electric wire has been constructed by placing an optical cable housed in a metal reinforcing tube at the center, with a steel core made of multiple steel wires on top of it, and then a steel core made of multiple aluminum wires on top of it. A device with an aluminum stranded wire layer is known.

However, since the steel wire and aluminum wire that make up this overhead wire have a circular cross section,
If external forces such as pressing force when passing through a steel wheel, compressive force or tightening force when installing a retaining crank are applied during the extension of the wire, the steel wire is likely to cave in, and therefore the optical cable is not stored. There is a risk that the metal reinforcing tube may be crushed and damage the optical cable. Also, during rainy weather, water tends to enter between the steel core and the metal reinforcing tube, so if the moisture freezes, the metal reinforcing tube may be crushed and the optical cable may be damaged. There is a risk of damage. Furthermore, when the mechanical strength of the metal reinforcing tube is increased, its flexibility is reduced and its handling becomes troublesome.

On the other hand, as for other composite overhead electric wires, a steel core is constructed by twisting a plurality of steel wires each having a cylindrical cross-sectional shape divided into multiple parts along the circumferential direction into a cylindrical cross-section. It is known that an optical cable is housed inside the cable and an aluminum stranded wire layer is provided on the steel core.

However, in this overhead wire, a gap is formed between the inner surface of the steel core and the outer surface of the optical cable, so moisture easily enters between the two during rain, etc., and therefore, if the moisture freezes, There is a risk of damaging the optical cable.

The present invention improves these drawbacks.

This will be explained based on an embodiment shown in FIG.

In the figure, 1 indicates a steel core, and this steel core 1 is made up of a plurality of steel wires 2 having a cross-sectional shape obtained by dividing a cylindrical shape into a plurality of parts along the circumferential direction, which are twisted together into a cylindrical cross-sectional shape. It is configured. Further, each steel wire 2 is galvanized.

A metal reinforcing tube 4 made of aluminum or the like is arranged in the central cavity of the steel core 1.

This metal reinforcing tube 4 has an outer diameter at least equal to the inner diameter of the steel core 1, and is configured so that it and the steel core 1 are in close contact with each other so that moisture does not enter between them. An optical cable is accommodated in the metal reinforcing tube 4 in a loosely fitted manner.

The optical cable 5 is made by twisting and assembling a plurality of optical fiber wires and covering this with glass fiber reinforced plastic (FRP).

Further, an aluminum stranded wire layer 6 is provided on the steel core 1 in close contact with the steel core 1.

The aluminum twisted wire layer 6 is constructed by twisting together aluminum wires 7 each having a cross-sectional shape obtained by dividing a cylindrical shape into a plurality of parts.

Further, the aluminum stranded wire layer 6 has each aluminum wire 7
The mutual contact surfaces 8 and the mutual contact surfaces 9 of the steel strands 2 are arranged at different positions in the circumferential direction to prevent moisture that has entered the aluminum stranded wire layer 6 from penetrating between the steel strands 2. There is.

In this embodiment, the steel core 1 is assembled by twisting the steel wires 2 together, but the steel wires 2 may be bundled together in parallel to each other in a straight line. In this case, it is desirable to provide a pressing layer such as a metal tape on the steel core 1.

Furthermore, the optical cable 5 is not limited to the one shown in the embodiments, but may be any arbitrary one, such as a collection of a plurality of optical fibers, which are then coated with FRP.

In addition, in this embodiment, the aluminum stranded wire layer 6 is constructed by collecting a plurality of aluminum wires 7 having a cross-sectional shape obtained by dividing a cylindrical shape into a plurality of parts along the circumferential direction so as to have a cylindrical cross-section. However, after twisting aluminum wires having a circular cross section, the aluminum wires may be compressed and deformed from the outer periphery so that the cross-sectional shape of the aluminum wires has the above-mentioned shape.

Furthermore, the aluminum stranded wire layer 6 can not only be provided in a plurality of layers as required, but also may be constructed by twisting aluminum wires 7 having a circular cross section as shown in FIG.

According to the composite overhead wire of the present invention, a plurality of steel wires having a cross-sectional shape obtained by dividing a cylindrical shape into a plurality of parts along the circumferential direction are assembled into a steel core having a cylindrical cross-section, and the steel core. It consists of an aluminum stranded wire layer provided above, a metal reinforcing tube placed in the hollow part of the steel core, and an optical cable housed in the metal reinforcing tube, and the outer surface of the metal reinforcing tube and the inner surface of the steel core are closely attached to each other. Since the structure is configured in such a manner that the following synergistic effects are achieved.

In other words, since the steel core is a collection of so-called segment-shaped steel wires, its compression resistance is extremely high. Even when an external force such as a tightening force is applied, the steel wire does not collapse, and therefore there is no possibility that the optical cable will be damaged by the external force.

In addition, as mentioned above, the steel core is composed of a collection of segment-shaped steel wires, and the inner surface of the steel core and the outer surface of the metal reinforcing tube are brought into close contact, so it is almost impossible for moisture to infiltrate between the two. Therefore, there is almost no risk of damage to the optical cable due to moisture freezing.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the composite overhead wire of the present invention, and FIG. 2 is a sectional view showing another embodiment. 1... Steel core, 2... Steel wire, 4... Metal reinforcing tube, 5... Optical cable, 6... Aluminum stranded wire layer, 7
... Aluminum wire, 8 ... Contact surface between aluminum wires, 9 ... Contact surface between steel wires.

Claims (1)

[Scope of utility model registration request] A steel core formed by aggregating a plurality of steel wires having a cross-sectional shape obtained by dividing a cylindrical shape into a plurality of parts along the circumferential direction, and an aluminum stranded wire layer provided on the steel core; A composite aerial comprising a metal reinforcing tube disposed within a hollow portion of a steel core and an optical cable housed within the metal reinforcing tube, the outer surface of the metal reinforcing tube and the inner surface of the steel core being in close contact with each other. Electrical wire.