JPS61243674A - Formation of internal semiconductor layer for cable connection - 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] [Background and Objectives of the Invention] The present invention is particularly directed to the prevention of polio in cross-linked polyethylene insulated vinyl sheathed cables (hereinafter referred to as CV cables).
The present invention relates to a method for forming a straight connection portion formed by molding an insulator, and particularly to a method for forming an internal semiconducting layer.

For ultra-high voltage or ultra-super-high voltage lines of 154 Kv or higher, the linear connection for Cv cables is generally a molded connection made of polyolene, which is the same material as the cable insulation. .

The molded connection part is formed by laminating and winding polyolefin Teso containing a crosslinking agent or a molded sheet, by extrusion molding using an extrusion device, or by heat crosslinking molding using a polyolefin molded block or the like as an insulator. In addition, the molded suction part has an inner semiconducting layer and an outer semiconducting layer similar to a cable, but in this case, the semiconducting s9 IJ
It is formed from a pre-molded one-knit piece using olefin or semiconductive rubber, a laminated roll of the same, or a heat-shrinkable tube made of semiconductive polyolefin or rubber.

In any case, the internal semiconducting layer of the connection part must be integrated with the internal semiconducting layer of the cable, otherwise electrode misalignment will occur at the joint, causing serious problems in terms of electrical properties. In other words, when forming the internal semiconducting layer of the connection part with a pre-molded unit, etc., these do not fuse with the internal semiconducting layer of the cable, and therefore the mold is not bonded between the connection part and the inside of the cable≠conductive layer. In many cases, the insulator penetrates and electrically separates the two, resulting in electrode irregularities.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming an internal semiconducting layer of a c'v cable connection part that does not cause electrode irregularities as described above.

[Summary of the invention]

According to the present invention, the above object is achieved by winding and molding a semiconductive polyolefin tape or sheet between the internal semiconductive layer of the connecting portion and the internal semiconductive layer of the cable to integrate the two.

〔Example〕

1 is a diagram schematically showing a connecting portion obtained by the method of the present invention, and FIG. 2 is an enlarged view of the main part thereof.

In Fig. 1.2, the molding type 1 connection connects the conductor of a Cv cable 7 with a connection tube 1, and around it, an internal semiconducting layer 2 is provided, and an insulating layer 5 and an external semiconducting layer 6 are provided.
It is formed by providing and integrating. Connecting part internal semiconducting layer 2
is formed using semiconductive rubber, a pre-molded unit made of plastic, a heat-shrinkable tube, etc., and the insulating layer 5 is formed by laminating and winding polyolefin tape or sheet, by arranging a polyolefin molded block, or by extrusion molding of polyolefin. It is formed by doing the following. The outer semiconducting layer 6 is also made of the same material as the inner semiconducting layer 2.

Generally, these elements are individually or collectively heated to a predetermined temperature and mold crosslinked under pressure.

On the other hand, the internal semiconductive layer 2 of the connection part is the internal semiconductive layer 3 of the cable.
It is superimposed with. Unless a special method is used, the ends of this overlapping portion will cause electrode irregularities as described above.

FIG. 2 shows special processing according to the present invention for this part. In FIG. 2, a semiconductive polyolefin tape or a molded sheet thereof is wound between the connecting portion internal semiconductive layer 2 and the cable internal semiconductive layer 3, and the internal semiconductive molded layer 4 is formed by heat molding. This molded layer 4 is integrated with the internal semiconductive layer 2 of the connection part and also with the internal semiconductive layer 3 of the cable. They are brought into contact and integrated through the mold layer 4. [Effects of the Invention] According to the present invention, the problem of electrode misalignment that frequently occurs in conventional connection parts can be completely solved, and the electrical characteristics of the connection part can be significantly improved. This is because the internal semiconducting molded layer made of the same material only needs to be provided at the tip of the internal semiconductive layer of the connection part, so the molding can be carried out in a short time.
5. The method itself is extremely simple, and the industrial advantages are extremely significant.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a cable connection according to the method of the invention;
FIG. 2 is an enlarged view of the main part of FIG. 1. 1... Conductor connecting pipe, 2... Semiconducting layer inside the connecting part,
3...Cable internal semiconducting layer, 4...Internal semiconducting molded layer, 5...Insulating layer, 6...Outer semiconducting layer, 7...
・CV cable. Agent Patent Attorney Fujio Sato Asu1

Claims (1)

[Claims] 1. When the cable connection part is heat-molded using polyolefin, which is the same material as the cable insulator, the internal semiconducting layer of the connection part may contain a pre-molded rubber or plastic semiconducting material. The inner semiconductive layer of the cable connection part is formed by integrally molding the tip of the inner semiconducting layer with the inner semiconducting layer of the cable by molding semiconductive polyolefin. Method of forming a semiconducting layer. 2. The method of claim 1, wherein the preformed rubber, plastic semiconductive material is a heat shrink tube. 3. The method of claim 1, wherein the preformed rubber, plastic semiconducting material is a preformed premolded unit.