JPS6258823A - Connection of 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 [Industrial Application Field] The present invention relates to a CV cable connection section, and particularly relates to lamination at a CV cable connection section.

``Prior art'' A CV cable is basically an electrical cable made of a conductor coated with an insulating layer made of cross-linked polyethylene resin. The tip of the exposed conductor is then brought into direct contact with the tip of the similarly exposed conductor of another cable to be connected, and this is fixed and joined using a conductor connecting tube, and an internal semiconductive layer is formed on top of this. There is a method in which a heat-shrinkable semiconductive polyolefin tube is heat-shrinked into a predetermined shape and attached, and then an insulator made of a heat-softening synthetic resin is formed using a molding die and an extrusion device.

The performance of the connection portion obtained by this method is extremely excellent, and it is highly reliable as a connection method for CV cables. Therefore, this method is particularly suitable for
It is expected to be used for straight connection of CV cables for Kv to 500Kv.

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, since the end of the tube provided as the internal semiconductive layer is usually cut with scissors or a knife, protrusions are formed on the cut surface. However, if an insulating layer is formed on this periphery by molding an insulator, the protrusions may reduce the withstand voltage characteristics, resulting in deterioration of the characteristics of the cable connection portion. Therefore, after the insulator mold is formed, the surface of the internal semiconducting layer is checked using, for example, a soft X-ray imaging device. Therefore, the interface between the two cannot be clearly seen when photographed using a soft X-ray imaging device, and it has therefore been impossible to confirm whether or not there is any irregularity in the electrodes of the internal semiconductive layer.

In the cable connection method described above, electrode irregularities are most likely to occur at the tip of the semiconductive heat-shrinkable tube, especially as the semiconductive layer, so it is necessary to be able to confirm this area with a soft X-ray imaging device. Met.

Means and operation for solving the problems The present invention solves the problems in the prior art described above.
The purpose is to provide a new method for treating the ends of the internal semiconductive layer of the extrusion-molded connection, which includes a conductor, an insulating layer made of cross-linked polyethylene resin surrounding the conductor,
Furthermore, at the connection part of the Cv cable consisting of the sheath that covers the top, the tip of the conductor exposed by stripping and the tip of the similarly exposed conductor of the other Cv cable to be connected are fixed using a conductor connecting tube. , an end to be connected of the joined Cv cable, a semiconductive heat-shrinkable polyolefin tube is coated thereon, an inner semiconductive layer formed by heat treatment, and both ends of the layer are coated. This is a Cv cable connection part characterized by comprising an annular rubber body having high elasticity and semiconductivity, and an insulating coating layer formed on the annular rubber body.

The cable to which the present invention is directed is the "CV cable," which is currently the most commonly used electric cable.
The general structure is that a conductor is coated with a wire core made of a cross-linked polyethylene resin as an insulating layer.

To connect these CV cables in a straight line and form a connection according to the present invention, first, the ends of the two cables to be connected are stripped off, and the exposed conductors are brought into contact with each other. At this time, a heat-shrinkable semi-conductive polyolefin tube and a semi-S conductive annular rubber body, which is the most characteristic feature of the present invention, are necessarily fitted to each end by caulking. A single conductor connecting tube that covers both conductors is fitted into the protruding conductors, and pressure is applied from the outside to crush the connecting tube, thereby fixing and joining the ends of both conductors. Next, an internal semiconducting layer is formed on this by heat shrinking, which has necessarily been fitted in advance.

Usually, the edges of this layer are processed by cutting, molding, processing, etc. using a knife, but this treated edge causes the problem of deterioration of the properties described above. Therefore, in the present invention, a semiconductive annular rubber body, which has been fitted into the stripped part of the caulking step, is shifted and placed on the treated end, and the end is coated.

``Example'' Figures 1 (a), (b)), and (c)) sequentially illustrate the outline of the method in the example of the present invention. On the other hand, only the symmetrical upper half of the stripped part of cable 1 and part of the part to be coated is shown. ) is fitted, and a conductor connecting pipe 2 is attached to one conductor exposed by stripping the steps.In the figure (b), the conductor 11
And at the connection part of the conductor connecting pipe 2, there is a heat-shrinkable semi-conductive cross-linked polyethylene resin tube 3 (Ca) which was not shown in the figure, but which had been fitted in advance to the cable 1.
(cross section shown) is spread out and mounted, heat treated to shrink and fixed as shown. Next, we arrive at FC) figure,
The annular rubber body 4 previously fitted to the cable
The ends of the joints are treated by shifting them as shown in the figure.

This annular rubber body is semiconductive and has elasticity from room temperature to high temperatures of about 150°C, and is made of materials such as polybutadiene, ethylene propylene rubber,
It is a semiconductive material such as silicone rubber, and FIG. 2 shows a cross section of one example thereof. When this annular body is arranged as described above, the tube 3, the cable 1
The tube 3 is in close contact with the conductor 11 and the internal semiconductive layer 12.
At the same time, the ends of the semiconductive layer are formed into a smooth shape.

After the annular rubber body 4 is fixed in position, it can be heated to shrink and harden, thereby forming a strong end.

(C) After processing as shown in the figure, a thermoplastic resin is molded thereon to form a connection part having the same structure as in the case of the prior art.

``Effects of the Invention: The connecting portion of the cable of the present invention has a smooth internal semiconductive layer with no electrode irregularities, and furthermore, the annular body is made of a semiconductive rubber body, so compared to the external insulating layer. Since the degree of X-ray absorption differs between the electrodes, the shape of the electrode at the end can be clearly photographed and confirmed by X-ray photography, and the end treatment of the internal semiconductive layer is extremely simple, and it has excellent electrical performance. It has many features such as being able to create connections with

[Brief explanation of the drawing]

FIG. 1 (a), (b), and (C) show Cv of the present invention in order.
FIG. 2 is a diagram showing a procedure for forming a cable connection part and includes a partial cross section of the symmetrical upper half of the connection part of the cable, and FIG. 2 is a sectional view of a semiconductive and elastic annular rubber body. In the figure, "r: CV cable, 1: its conductor, 12: its internal semiconductive layer, 2: conductor connecting tube, 3: heat shrink tube, 4: annular rubber body

Claims (1)

[Claims] At the connection part of a CV cable consisting of a conductor, an insulating layer made of cross-linked polyethylene resin surrounding the conductor, and a sheath covering the top, the tip of the conductor that is stripped off and exposed is connected to the other CV cable to be connected. Similarly, the tip of the exposed conductor is fixed and joined with the conductor connecting tube.
The end of the V cable to be connected, a semiconductive heat-shrinkable polyolefin tube coated thereon, an inner semiconductive layer formed by heat treatment, and an elastic layer coated on both ends of the V cable. 1. A CV cable connection portion comprising a semiconductive annular rubber body and an insulating coating layer formed thereon.