JPS60237812A - Method of producing connection unit for cv cable - 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 connection portion for a CV cable, and particularly to a method for manufacturing a connection portion by heating and melting a polyolefin insulator to form an insulating layer.

Due to its ease of handling, C-cable began to be used in ultra-high voltage systems such as V-lines in 275.

C ■ The connection part that is used integrally with the cable body is wrapped with insulating tape for low-voltage cables, but for ultra-high voltage cables, polyolefin insulators made of the same material as the CV cable insulation are used for reliability and electrical performance. , a mold-type connection part is applied that is heated and melt-molded. The molded connection consists of three layers: an inner semiconducting layer, an outer semiconducting layer, and an insulating layer.

In general, the internal semiconductive layer is formed using a semiconductive heat-shrinkable tube or a rubber or plastic semiconductive pre-mold unit, which is heat-melt molded at the same time as the insulating layer described below is heat-melt molded. be exposed. The insulating layer is formed by extrusion molding a polyolefin insulator containing a crosslinking agent, by wrapping a polyolefin insulating tape containing a crosslinking agent, and then heating and melting it by molding it with a hot melt mold, or by applying a polyolefin insulating block containing a crosslinking agent. This is further carried out by heating and melting molding. The outer semiconducting layer is formed by using the same material as the inner semiconducting layer on the periphery of the insulating layer after forming the insulating layer, and then heating and melt-molding the material.

However, in this conventional manufacturing method,
Since the outer semiconducting layer is formed by molding on a crosslinked molded insulating layer, it is extremely difficult to completely bond and integrate the outer semiconducting layer with the insulating layer without any gaps, and sometimes There was a fear that the settlement between the two parties would be incomplete.

In addition, even if the adhesive was bonded well at the beginning, there was a risk that it would peel off over time.

Note that if the insulating layer and the external semiconducting layer are not completely bound together, corona discharge is likely to occur at the interface, resulting in a lack of electrical reliability of the insulating portion.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned disadvantages and to provide a useful method for producing connections for CV cables with significantly improved electrical reliability.

The gist of the present invention is that when molding the external semiconductive layer of a molded connection part, a semiconductive layer paint containing a crosslinking agent is applied on the insulating layer, and then a semiconductive heat shrink tube or a semiconductive The purpose of this method is to overlay a semi-conductive molded sheet or the like, and then heat mold it to integrate it with an external semiconductive layer such as an insulating layer.

Next, an embodiment of the present invention will be described with reference to the attached drawings. First, the insulator 31 of the CV cable 3 to be connected
The conductors 32 of the CV cable 3 are connected to each other by the conductor connecting tube 1, and the internal semiconducting layer 2 is formed on the top thereof.

The internal semiconductive layer 3 is made of semiconductive polyolefin heat shrink tube, semiconductive polyolefin, semiconductive rubber (
A pre-molded unit of semi-conductive EPR1 (semi-conductive chlorinated butyl, etc.) is molded in the same manner as before. Next, (2) an insulating layer 4 is formed on the oriented semiconductive layer 2;

The insulating layer 4 can be formed by extruding a polyolefin insulator containing a crosslinking agent using an extruder, or by wrapping a polyolefin insulator containing a crosslinking agent previously formed into a tape or sheet shape, and then heating and melt-molding this. Alternatively, crosslinking is formed by applying a polyolefin insulation block containing a crosslinking agent and further heating and melting it.

After that, a semiconductive polyolefin paint containing a crosslinking agent is applied to the surface of the insulating layer 4 to form a semiconductive paint coating layer 5, and a semiconductive polyolefin insulator or sheet is further covered, or a semiconductive polyolefin paint is applied. A polyolefin heat-shrinkable tube is placed over the tube, and the outer semiconductive layer 6 is formed by heat molding. The heat molding of the external semiconductive layer 6 is carried out after reaching the crosslinking temperature (160° C. to 200° C.), which is held for a required period of time (30 minutes to 2 hours), and then cooled.

According to the manufacturing method of the CV cable connection part of the present invention as explained above, when forming the external semiconductive layer on the insulating layer, first, a semiconductive paint is applied to the surface of the insulating layer, and then an optional coating is applied on the surface of the insulating layer. The bonding of the outer semiconducting layer to the insulating layer is very good because it is made by hot molding the semiconducting material of In other words, it is possible to manufacture a connection part that can significantly improve the electrical reliability of the interface.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing an example of the method for manufacturing the Cv cable connection part of the present invention. 1... Conductor connection tube, 2... Internal semiconductive layer. 3...CV cable, 4...insulation layer. 5... Semi-conductive paint coating layer. 6... Semiconductive polyolefin layer. Agent Patent Attorney Fujio Sato Continuation of page 1 @ Inventor Hirobe Nagano

Claims (1)

[Claims] (1) Form an insulating layer on the conductor connection part of the CV cable using a polyolefin insulator made of the same material as the cable insulator, and then apply a semiconductive paint containing a crosslinking agent on the formed insulating layer. . A method for manufacturing a connection part for a CV cable, characterized in that an outer semiconducting layer is provided thereon by thermoforming a semiconducting material.