JPH03201310A - Low noise electric wire - Google Patents

Abstract

PURPOSE:To enhance the fluidity of rain water in the circumferential direction of an electric wire which is wet with the rain water on its surface, by forming a spiral projection out of thick-walled segment strands on the outer periphery of an outmost layer strand wire and filling the gaps between the sides of adjacent segment strands with water-absorbing substance. CONSTITUTION:An outmost layer strand wire 1 is formed by stranding together many thin-walled segment strands 2 having a trapezoidal cross section and one or a few thick-walled segment strand 3 having a rectangular cross section and an outer peripheral surface in an arc. The thick-walled segment strands 3 have a projection part of a height H, which forms a spiral projection 4 on the outer periphery of the outmost layer strand wire 1. The thin-walled segment strands 2 and thick-walled segment strands 3 are placed in a circle while the side gaps between the strands 2, 3 are filled with water-absorbing substance 5. This prevents rain water from dropping from many places scattered in the longitudinal direction of the electric wire and a corona noise from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a low-noise electric wire that can cope with both wind noise and corona noise.

[Conventional technology]

Wind noise caused by Karman vortices generated behind electrical wires where cross winds act, and corona noise caused by raindrops adhering to electrical wires during rain, have become major problems in power transmission lines whose capacity has been increasing in recent years. There is.

Conventionally, wind noise among the above noises has been dealt with by winding a filament in a spiral around the outer circumference of the wire, or increasing the thickness of some of the strands that make up the outermost stranded wire of the wire in the radial direction of the wire. By forming a spiral protrusion on the outer periphery of the wire, the cross-sectional shape of the outer periphery of the wire becomes a non-circular shape that changes substantially in the length direction, thereby creating a Karman vortex street behind the wire where cross winds act. Low wind noise electric wires have been provided that are designed to prevent corona noise from being generated, and low wind noise electric wires that have been subjected to various surface treatments to prevent rainwater particles from adhering to the outer circumferential surface of the electric wires have been provided. AN wire is provided.

[Problem to be solved by the invention]

The above-mentioned conventional low wind noise electric wire and low AN electric wire are provided separately, and the low wind noise electric wire cannot cope with corona noise, and the low AN electric wire cannot cope with wind noise. It was impossible.

In addition, in a configuration that combines these two types, spiral filaments or protrusions are present on the outer periphery of the wire, resulting in a non-circular shape in which the cross-sectional outer periphery shape of the wire substantially changes in the length direction. Although this is effective in reducing wind noise, flowing rainwater tends to accumulate in the spiral striations and protrusions as well as the boundary between them and the wire surface. Water droplets fall from a large number of dispersed positions in the circumferential direction of the wire, increasing the number of discharge points, making it impossible to suppress the generation of corona noise.

[Means to solve the problem]

The low-noise electric wire of the present invention has an outermost stranded wire composed of a mixed strand of a large number of thin-walled segment wires and one or several thick-walled segment wires; A spiral protrusion is formed by thick segment wires, and a water-absorbing substance is interposed between the side surfaces of adjacent segment wires.

[Function] The spiral protrusion formed on the outer periphery of the outermost layer stranded wire, which is made of thick segment strands, makes the cross-sectional outer periphery of the wire a non-circular shape that changes substantially in the length direction, thereby preventing cross winds. This prevents the formation of a Karman vortex street behind the wire on which it acts.

Since each thin-walled and thick-walled segment wire has a smooth outer surface, the surface of the outermost layer stranded wire is smooth as a whole in the circumferential direction. Rainwater adhering to the wire surface has a much higher fluidity in the circumferential direction of the wire than in the wire.

The water-absorbing substance interposed between the side surfaces of adjacent segment wires absorbs rainwater flowing in the circumferential direction of the electric wire, and sequentially takes it into the intertwisting gap inside the stranded wire.

〔Example〕

1 to 3 show an embodiment of the low-noise electric wire according to the present invention, in which a large number of aluminum alloy wires are placed on a copper core 7 consisting of a plurality of twisted steel wires 6. Twisted wires made by twisting together are provided in multiple layers. In particular, the outermost stranded wire 1 has a large number of thin segment wires 2 having a substantially trapezoidal cross section and one to several wires (in the illustrated embodiment, two wires are arranged adjacent to each other at symmetrical positions of 180 degrees around the circumference, for a total of 4 wires). The thick segment wire 3 has a substantially rectangular cross section and an arcuate outer surface, and the thick segment wire 3 is twisted in a mixed manner. As shown in the figure, a spiral protrusion 4 is formed on the outer periphery of the outermost layer stranded wire 1.

A water-absorbing substance 5 is interposed between adjacent side surfaces of each of the thin segment wires 2 and the thick segment wires 3, respectively. Here, the water-absorbing substance 5 may be made of glass fiber, nylon fiber, polyester fiber, acrylic fiber,
It can be made of a nonwoven or woven material such as ceramic fiber, silica fiber, carbon fiber, or the like.

〔Effect of the invention〕

According to the low noise electric wire according to the present invention, the following effects can be obtained.

That is, the spiral protrusions 4 on the outer periphery of the electric wire formed by the thick-walled segment wires 3 prevent the generation of a Karman vortex street behind the electric wire where cross winds act, thereby preventing the generation of wind noise.

In addition, rainwater adhering to the outer circumferential surface of the electric wire during rainfall flows in the circumferential direction on the surface of each thin segment wire 2 and each thick segment wire 3, is captured and absorbed by the water absorbing substance 5, and from there. It is gradually incorporated into the twisted wire. Therefore, rainwater does not accumulate on the surface of the wire over its entire span, and rainwater is prevented from falling into particles from multiple points distributed in the longitudinal direction of the wire, thus preventing the generation of corona noise.

[Brief explanation of drawings]

The drawings show an embodiment of the low-noise electric wire according to the present invention, in which Fig. 1 is a cross-sectional view, Fig. 2 is a side view, and Fig. 3 is a segment wire that forms the outermost layer stranded wire at the bottom of the groove. FIG. In the figure, 1 is the outermost layer stranded wire, 2 is a thin segment wire, 3 is a thick inner segment wire, 4 is a spiral protrusion,
5 is a water-absorbing substance.

Claims (1)

[Claims] Thin segment wire (2) with many outermost layer strands (1)
and one or several thick segment wires (3), and a spiral protrusion formed by the thick segment wires (3) is formed on the outer periphery of the outermost layer twisted wire (1). (4)
are formed, and adjacent segment wires (2), (3
) A low-noise electric wire characterized in that a water-absorbing substance (5) is interposed between the sides of the wire.