JPS5918517A - Method of producing slackness suppression type 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 method for efficiently, easily and reliably manufacturing a slack-reduced electric wire.

By forming a small gap between the steel core of the steel core aluminum stranded wire and the aluminum wire and causing sliding between the steel core and the aluminum wire, the overhead wire tension is applied only to the steel core with a small coefficient of linear expansion. Sag-reducing electric wires can be used to increase current-carrying capacity using existing steel towers, so they are attracting attention today as a quick and easy response to the recent tightening of electricity demand. Ta.

There are various proposals as methods for manufacturing such a slack-reduced electric wire. However, they are not without problems.

Those in which the aluminum inner layer is made into a fan-shaped conductor require special processing of the aluminum wire, and those in which water-soluble substances are intercalated and eluted have the problem of corrosion due to residual inclusions, and plastic elongation is limited to aluminum wires only. Each type has its own drawbacks, such as those that require a special processing jig and careful consideration for curling the upper aluminum wire, and those that require a spacer to interpose a spacer, which has the problem of buckling.

The present invention minimizes such conventional problems,
The purpose of this invention is to provide a method for manually fabricating a slack-reducing electric wire in an extremely easy and reliable manner.

The feature of the present invention is that a corrugated metal intervening layer 4 is provided between the steel core 1 and the aluminum wire 2, as shown in FIGS. 1 and 2. An example of such a corrugated metal intervening layer 4 is a corrugated aluminum pipe, but it is of course not limited thereto. It may also be a metal tape formed into a corrugated shape.

In the present invention, in the production of steel core aluminum stranded wire, a corrugated metal intervening layer 4 made of, for example, a corrugated aluminum pipe is applied to the steel core 1 before the aluminum wires 2 are twisted on the steel core 1. . Preferably, the wire twisting machine is provided with such application steps in tandem.

Thereafter, the aluminum wires 2 are twisted on the corrugated metal intervening layer 4 in the same manner as in the production of ordinary steel core aluminum stranded wires.

After this twisting is completed, a pressing force is applied in the radial direction of the steel-core aluminum strands. As a means for this, a roll that grips and presses the steel-core aluminum stranded wire may be run in the longitudinal direction, but it is also possible to utilize the tension of the overhead wire and apply the pressing force when passing the metal wheel. There are many possible ways to do this.

FIG. 6 schematically shows a partial longitudinal cross-sectional view of the electric wire according to the present invention before the above-mentioned pressing force is applied. The corrugated aluminum pipe 4 has not yet been deformed and has a waveform with a pitch P1. FIG. 4 shows the corrugated aluminum pipe 4 deformed and reduced in diameter by applying a pressing force, and the waveform is flattened and changed to a pitch P2. This ensures that a gap 3 is created between the steel core 1 and the aluminum wire 2.

In the present invention, a pressing force is applied from the outside, but at that time, the corrugated aluminum pipe 4 is selectively deformed, so that the problem of aluminum cracking that occurs in the conventional example does not occur.

Further, if the intervening layer is a metal such as aluminum, it naturally acts as a conductive member, so the presence of the corrugated metal intervening layer can be expected to have the additional effect of improving the current carrying capacity.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the electric wire according to the present invention, Fig. 2 is a perspective view of the same with steps stripped, and Figs. 3 and 4 are models of the electric wire before and after applying a pressing force = 6-molding. FIG. 1: steel core, 2: aluminum wire, 3: small gap, 4: corrugated metal intervening layer. 5- 4- Bullet + []

Claims (1)

[Claims] 1. In manufacturing a steel core aluminum stranded wire in which aluminum wires 2 are twisted around the circumference of a steel core 1, a corrugated metal intervening layer 4 is provided around the outer circumference of the steel core 1, and the aluminum wires 2 are twisted around the outer circumference of the steel core 1. Then, by applying a pressing force in the radial direction of the stranded wire, the wave shape of the corrugated metal intervening layer 4 is stretched to reduce its diameter, and a small gap 3 is formed between the steel core 1 and the aluminum wire 2. A method for manufacturing a slack-reducing electric wire.