JPS5889714A - Low noise wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low-noise electric wire that reduces the noise of electric wires caused by wind pressure and also reduces corona noise (so-called audible noise).

Wrap the wire in a spiral along the outer circumference of the wire,
Low-noise electric wires are known that prevent the generation of noise due to wind pressure on the wires by creating turbulence in the air around the wires. In this case, there is no problem on sunny days, but on rainy days, the rainwater is blocked by the spiral wire, and the raindrops grow large and generate corona from their tips, which adversely affect the surrounding area as audible noise. I have something to give.

This cannot be ignored in today's world where power transmission lines are becoming increasingly high-voltage.

The present invention aims to provide a low-noise electric wire that prevents such adverse effects from occurring.

In order to prevent the occurrence of corona during rain, it is necessary not only to prevent raindrops from growing, but also to reduce the potential gradient of the strands themselves.

The inventors conducted various experiments to reduce both of these factors, and found that by forming two strands of wire with a pseudocircular radius r in cross section into a ω-shaped cross section, water droplets could be efficiently removed. The finding is that it can reduce hypertrophy and its own potential gradient.

FIG. 1 is an explanatory diagram showing how a wire 2 according to the present invention is wound around an electric wire 1.

Such a wire 2 has a configuration as shown in FIG. In other words, Figure 2 (a) is the basic idea,
Element # with a cross section of virtual radius r! By attaching two pieces together, the cross section is constructed into an ω-shape.

FIG. 2(B) shows the solid line portion of FIG. 2(A), which is the strand 2 according to the present invention.

The wire 2 is wound around the outer circumference of the electric wire 1 in the longitudinal direction as shown in the cross-sectional view of FIG.

Since the strand 2 constructed in this manner has the concave portion 2a, the concave portion 2a corresponds well to the surface tension of the rainwater, and the raindrops gradually fall down before becoming enlarged. Since the strand 2 itself consists of two virtual circumferences 'fr' attached together, its own potential gradient can be kept to a minimum.

As shown in Fig. 2 (a), such a wire 2 is defined by L/'l, where the radius of its pseudocircle is r, and the distance between the centers of the pseudocircles is t.
Plot the value of r.

L/2 r = O is a state in which one strand of wire has a radius of r, and t/2r=1 is a state in which two strands of wire with a radius of r are in contact with each other.

The horizontal axis shows t/zr, and the vertical axis shows audio pull noise A.
Take the rate of decline of N. The strand is in one state, that is, t/2r
Even if = 0, it is AN in the state of two contacts, that is, L/2r1.
It can be seen that the values are poor and that there is an optimal condition in the middle. In other words, the optimal condition is t/2r-IJE
O, 2-0.7 (D range theal.

In view of the fact that in the future, as the noise reduction of power transmission lines is becoming more and more important, and the transmission voltage of the power lines is also increasing to ultra-high voltages, the effects of the present invention can be said to be truly significant.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment according to the present invention, Fig. 2 is an explanatory diagram showing the structure of a strand, Fig. 6 is a sectional view showing the cross section of Fig. 1, and Fig. 4 is a diagram showing t/2r It is a diagram showing the relationship of AN. 1: Electric wire, 2: Spiral wire. Continued from page 1 0 Inventor Tsuyoshi Sato 1500 Kawajiri-cho, Hitachi City Toyoura Factory, Hitachi Cable Co., Ltd. Applicant Hitachi Cable Co., Ltd. 2-1-2 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] 1. In a low-noise electric wire made by winding a strand of wire in a spiral shape in the longitudinal direction of the outer periphery of the wire, the shape of the strand is formed into a cross-section ω-shaped by combining two unit pieces with a virtual radius r, and A low-noise electric wire configured such that the value of L/2r is in the range of 0.2 to 0.7, where t is the distance between the centers of the strands of strands having an ω-shaped cross section.