JPS58108610A - Method of producing watertight conductor - 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 manufacturing a watertight conductor in which a watertight mixture is filled between the strands of a stranded conductor.

Recently, abnormal disconnection accidents have occurred on outdoor power distribution lines, which has become a problem, but this is thought to be caused by oxidation and corrosion of the conductor wires caused by moisture that has entered between the wires of twisted IS conductors. It is being

Therefore, one possible measure to prevent these accidents is to use watertight cables.

A suitable watertight cable is one in which the gaps between the stranded conductors are filled with a watertight mixture over the entire length of the cable.

It is also necessary that the watertight mixture can be filled between the strands of the stranded conductor evenly, and that a completely watertight structure can be obtained after filling.

The present invention has been made in view of the above points, and includes:
The object of the present invention is to provide a method for manufacturing a watertight conductor in which a watertight mixture can be evenly filled between the strands of a stranded conductor.

That is, the gist of the present invention is to supply and fill a watertight mixture molten with egg heat into a twisting die of a wire twisting machine while heating it, and thereby fill a gap of a twisted wire conductor with the mixture in the die. The purpose is to sequentially fill the

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 1 shows the same stranding operation with 19 wires, 1 is the center strand, 2 is the 6-strand strand, 3V: 112 strands, 4 is the extruder, and 5 is the 7-strand wire. Co-twisted Rodice, 6 is a sword heat heater, 7 is a 12-stranded Rodice, 8 is a watertight mixture.

In the case of 19-strand twist, when the seven wires 1 and 2 excluding the outermost layer enter the die 5, a thermoplastic watertight mixture heated and melted sufficiently in the extruder 4 to lower the melt viscosity and improve permeability is added. The mixture is poured into the twisting die 5, and the die 5 is heated with a hot heater 9 (see Figure 4) to prevent the sufficiently molten watertight mixture from hardening. and remove excess watertight mixture.

Further, in order to prevent the outermost layer from cooling and hardening during twisting, it is heated with a thermal heater 6, and the wires 3 are twisted thereon.

For example, diameter 6. For the 19-stranded wire of 19 Oz, ethylene-vinyl acetate copolymer was used as the thermoplastic water-tight mixture, the extruder temperature was 15 A"C, the die diameter was 96 Da, and the water-tight mixture from the extruder was 20 g/m Pour at the rate of
140-160℃ for twisted logs, 180-2 for hot cylinder
A completely watertight structure could be obtained by heating to 00°C [7 JD.

FIG. 2 is a cross-sectional view after 7 twists in an embodiment according to the present invention, and FIG. 3 is a cross-sectional view of a watertight conductor with 19 twists.

Generally, in this type of conventional production method, the watertight mixture is filled before or after the wire is twisted, but before the wire is twisted, the watertight mixture is heated sufficiently as the strands are at room temperature. However, since the watertight mixture that comes into contact with the strands cools and hardens, it is difficult to fill the interior of the strands, and since the strands are still cold even after twisting, the watertight mixture is In any case, it is difficult to produce a completely watertight conductor.

However, according to the above-mentioned embodiment, the stranded die is heated and filled with a watertight mixture that has been thermally melted, and the mixture is sequentially applied to the gaps between the stranded wire conductors within the die. By filling, the watertight mixture can be evenly filled at the center of the stranded conductor.

In this embodiment, a 19-wire configuration is shown, but it goes without saying that the present invention can also be applied to 7-strand, 37-strand, or more twist configurations.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the method for manufacturing a watertight conductor of the present invention;
Figures 2 and 3 are a partial side view of the section A-A' and B-B'.
FIG. 4 is an explanatory diagram of a seven-stranded rod die. 1.2.3: Element wire, 4: Extruder, 5: 7-twisted rotisserie, 6: 7+o thermal heater, 7: 12-twisted rotisserie, 8: Watertight mixture, 9:) J0 thermal heater, 1
0: Bobbin. De-(jJ I) 1-' O 72 Figure 73 Figure 4 Figure

Claims (1)

[Claims] The method is characterized in that, while heating the twisting die of the wire twisting machine, a watertight mixture heated at the edge of the cutting edge is supplied and filled, thereby sequentially filling the gaps between the twisted wire conductors in the die. A method for manufacturing a watertight conductor.