JPS623530B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a watertight electric wire manufacturing method.

For outdoor high-voltage distribution lines, outdoor low-voltage distribution lines, undersea cables, etc., a watertight compound is filled between the conductor wires along the entire length of the wires to prevent moisture from entering and prevent abnormal disconnections due to oxidation and corrosion of the conductor wires. I'm trying to prevent it.

Conventionally, in order to manufacture watertight electric wires as described above,
The conductor strands are twisted together and a watertight compound is filled between the strands, so that the product has a completely watertight structure.

In the above manufacturing method, the watertight compound supplied between the wires by the extruder cools while the wires go to the twisting die, and especially in the case of round twisted conductors, when the wires are squeezed by the die, the watertight compound is cooled. Since the solidified watertight compound pushes up the conductor, the conductor surface and the die are strongly rubbed, which may cause scratches on the conductor surface. Also, when a problem occurs in the conductor,
There was a drawback that watertightness decreased.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to obtain a watertight electric wire manufacturing method that does not cause damage to the conductor in the twisting die and does not cause the risk of deterioration of watertightness.

In the present invention, the above object is achieved by insulating or heating the conductor between the extruder supplying the watertight compound and the twisting die.

The invention will be explained in detail below with reference to the drawings. In FIG. 1, a watertight compound is supplied by an extruder 4 to a 6F center conductor 3 supplied from a supply reel 2 to a first stage stranding machine 1 that forms a 6F stranded wire. Stranding die 1 of wire twisting machine 1
The center conductor 3 is kept warm between it and the heat insulating tube 5.

Passed through the twisting die 1a of the first stage twisting machine 1
A watertight compound is supplied to the 6F stranded wire 6 by the second extruder 7, and heat is kept between the extruder 7 and the twisting die 8a of the second stage wire twisting machine 8 that twists the conductor strands onto the 6F stranded wire. The tube 9 keeps the 6F stranded wire warm. 1st
In the figure, 10 indicates a take-up machine, and 11 indicates a winding machine.

In the above manner, the compound supplied from each extruder will not be cooled and solidified until it enters each twisting die, and there is no risk of damage to the conductor surface or deterioration of watertightness due to this.

FIG. 2, in which the same parts as in FIG. 1 are denoted by the same reference numerals, shows another embodiment of the present invention. In this example,
In place of the heat retaining cylinders 5 and 9, heating cylinders 12 and 13 having small-diameter openings on the side of the twisting dies 1a and 8a are provided, and hot air is supplied by nozzles 4 and 15 from these openings on the extruder side. In this embodiment as well, the watertight compound does not cool or solidify, and the same effects as in the previous embodiment can be obtained.

FIG. 3, in which the same parts as in FIGS. 1 and 2 are denoted by the same reference numerals, shows still another embodiment. In this embodiment, induction coils 16 and 17 are provided in place of the heat insulating tubes 5 and 9 shown in FIG. 18 and 19 indicate high frequency power supplies. This embodiment also provides the same effects as those of the embodiments described above.

[Brief explanation of the drawing]

1, 2, and 3 are schematic diagrams of first, second, and third embodiments of the present invention. 1, 8... wire twisting machine, 1a, 8a... twisting die, 3... central conductor, 4, 7... extruder, 5, 9
...heat insulation tube, 6...6F stranded wire, 12,13...heating tube, 16,17...induction coil.

Claims (1)

[Claims] 1. A watertight electric wire manufacturing method characterized by keeping the conductor warm or heating it between an extruder that supplies a watertight compound and a wire twisting die.