JPH0354803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Background and Objectives of the Invention] The present invention relates to a low-noise, low-vibration electric wire that can be easily tied, connected, clamped, etc.

Traditionally, low-noise electric wires have been widely used by winding spiral strands, but this requires the manufacture of separate strands and the installation is done using a spacecraft, which poses safety and efficiency problems. There were various problems that needed to be solved, such as a decrease in corona properties due to the protrusion of the strands, and vibrations caused by increased wind pressure loads.

Research on wind noise in power transmission lines has made great progress in recent years, and it has become possible to predict routes where noise may occur in advance.

Therefore, instead of winding a separate member such as the spiral wire, if the power transmission line is configured to have a noise-preventable structure and is connected directly to the route, the wire will not accompany the spiral wire winding. All problems will be resolved.

Based on this knowledge, the applicant has already
We also proposed a low-noise, low-vibration electric wire as shown in Figure 2.

That is, at least the outermost wire of the electric wire 10 is formed into segment wires, and the thicknesses of the wires in the radial direction of the wire are made to be different, such that the wire 1 has the smallest thickness, the wire 2 has the next thickness, or if necessary, further This is a wire in which thick wires 3 are twisted together in a mixed manner, and step surfaces 10a, 10b, or 10c are formed on the outer periphery of the wire, respectively.

Fig. 5 shows the actual wind tunnel noise results for the electric wire having the structure shown in Fig. 1. Here, D ₁ is the diameter of the 10b plane,
θ is the central angle of the plane 10b, h is the step height between the planes 10a and 10b, and V is the wind speed.

The figure clearly shows how the wind noise prevention is remarkable, but experiments have also shown that it not only reduces wind noise, but also reduces wind pressure vibration of electric wires, making the conventional dampers unnecessary. It was confirmed by.

However, as is clear from Figures 1 and 2, when this type of wire is crimped with a dead clamp, connected with a straight sleeve, or held with a spacer clamp,
There is a possibility that sufficient pressure bonding or gripping may be prevented due to the stepped portion.

The present invention aims to provide an electric wire that can maintain the low noise vibration effect and achieve the above-mentioned crimping and gripping without much difference from conventional electric wires.

[Summary of the invention]

That is, the gist of the present invention resides in that the strands forming the high stepped surface of the electric wire having the stepped portion are formed into a hollow shape.

This makes it extremely easy to deform the strands, and allows conventional retaining clamps, connecting sleeves, clamps, etc. to be used as they are.

〔Example〕

Embodiments according to the present invention are shown in FIGS. 3 and 4. Fig. 3 shows hollow holes 2a, 2a extending in the longitudinal direction formed in the strands 2, 2 forming a high step, and Fig. 4 shows the strands 2, 2 forming a high step.
Hollow grooves 2b, 2b extending in the longitudinal direction are formed in 2. In the case shown in FIG. 4, an appropriate compound may be filled in the groove 2b to prevent rainwater from accumulating.

〔Effect of the invention〕

Since the electric wire according to the present invention has a hollow interior as described above, the wire having a high step can be easily deformed and its surface can be easily made to be the same as the low wire 1, 1. Therefore, it is easily deformed by clamping or sleeve crimping, and only that part becomes circular in cross section, and crimping is achieved extremely reliably.
Conventionally used accessories and tools with a circular cross section can be used as is. Therefore, since the portion other than the crimped portion is maintained as a step surface as it is, the layer does not affect the low noise and low vibration effect inherent to the present invention.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of the electric wire already proposed, FIGS. 3 and 4 are cross-sectional views of the electric wire according to the present invention, and FIG. 5 is a diagram showing the low noise effect. 1, 2, 3: Segment wire, 2a, 2b: Hollow part, 10: Electric wire, 10a, 10b, 10c:
stepped surface.

Claims (1)

[Claims] 1. An electric wire in which at least the outermost layer of the stranded wire is composed of segment wires, and a step surface is formed in a spiral shape on the outer periphery, and the wires forming the step surface with a high step portion are configured in a hollow shape. Low noise and low vibration electric wire.