JPS6249185B2 - - Google Patents

Description

[Detailed Description of the Invention] Background There are two types of connections for rubber/plastic cables manufactured on-site: a tape-wrapped type and a molded type, each of which has the following advantages and problems.

It has the advantages of (1) tape-wrapped connections, (1) no heating and cooling processes, and (2) short construction time. However, (1) the withstand voltage value is lower than that of a molded connection, and creeping paths are likely to occur especially at the interface with the cable insulation, (2) the cable insulation shrinks back during use, and the tape There is a concern that a gap may form between the wound insulator and the insulator.

(2) Molded connection, excellent reliability. However, the heating and cooling process takes a long time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber/plastic cable connection that combines the simplicity of a tape-wrapped connection and the high reliability of a molded connection.

Embodiment FIG. 1 schematically shows a cross section of a connecting portion according to the present invention. 10 is the entire cable, 12 is a cable insulator, 14 is a cable conductor, and 16 is a conductor connection portion. 20 is the entire reinforcing insulator.

Most of the layers 24 of the reinforcing insulator 20, excluding the side in contact with the cable, are made of a layer wrapped with self-adhesive tape such as EP rubber.

In addition, the thin layer 22 on the side in contact with the cable is formed by wrapping an insulating tape such as EP rubber containing a cross-linking agent, heating and cross-linking it, and forming the thin layer 22 on the inner surface of the self-fusing tape-wrapped layer 24 and the cable insulating layer 12.
It consists of a mold layer fused to the surface of. That is, the cable insulating layer 12 and the self-bonding tape wrapping layer 24 are fused together via the thin layer 22 of the insulating tape wrapping layer containing a crosslinking agent.

An example of how to make the reinforcing insulator 20 (1) For example, wrap an EP rubber tape containing a crosslinking agent over the conductor connection portion 16 (including the internal semiconductive layer) and the cable insulator 12 in the vicinity thereof. This should be thin. In some cases, only one layer may be used. (2) Moreover,
The tape-wrapped insulator 24 is constructed by winding up the same self-fusing tape used for conventional tape-wrapped connections to a predetermined size. (3) Then, heating is performed from the cable conductor 14 side by a known high frequency induction heating method. The EP rubber tape containing a crosslinking agent is melt-crosslinked to become a molded insulator 22 and fused to the cable insulator 12. Further, when the EP rubber tape containing a crosslinking agent melts, a small portion of the tape-wrapped insulator 24 that circumscribes it also melts and is fused to the molded insulator 22.

With this method, only a very thin portion up to the crosslinking agent-containing EP rubber tape layer needs to be heated, so the heating time is only a few tenths of the time required for conventional molded connections.

Another column for how to make (1) As shown in "Figure 2", for example, with cross-linking agent
A thin layer of EP rubber tape 220 (this is the same as in the previous example) is made, and a thin layer of self-fusing tape 240 (eg, 1 to 2 wraps) is made on top of it. (2) Wrap it with Teflon tape, etc., and
Heat from the outside and melt and mold the inside. The layer of cross-linking EP rubber tape 220 becomes the mold insulation 22 and is fused to the cable insulation 12. The layer of self-fusing tape 240 also becomes part of the tape-wrapped insulator 24 and molded insulator 24.
Fuses with 2. (3) After cooling, the presser tape 26 is removed and the self-fusing tape 242 is wound up to a predetermined size on top of it to complete the tape-wrapped insulator 24. In this method, the layer to be heat molded is thin, so
The heating time is a fraction of that of a molded connection.

Advantages of the Invention (1) Only a few parts need to be heated and molded, and most of the reinforcing insulator 20 can be made up of tape-wrapped connections, so the advantage of tape-wound connections in that the construction time is short can be utilized.

(2) Since the portion in contact with the cable 10 is composed of the heating molded insulator 22, it is strong against creeping and can resist shrinkage back. Therefore, in practice, a highly reliable connection equivalent to that of a molded connection can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view schematically showing a vertical cross-sectional elevation of an embodiment of the present invention, and FIG. 2 is an explanatory view showing a state in the middle of an example of how to make a reinforcing insulator 20. 10... Cable, 12... Cable insulator,
16...Conductor connection part, 20...Reinforcement insulator, 22
...heat molded insulator, 24...tape-wrapped insulator.

Claims (1)

[Claims] 1 Most of the layers of the connection reinforcing insulator, excluding the side in contact with the cable, consist of a layer wrapped with self-adhesive tape, and the thin layer on the side in contact with the cable is made of a crosslinking agent. A rubber/plastic cable comprising a layer wrapped with a self-bonding insulating tape, and a mold layer which is heated and cross-linked to fuse the inner surface of the self-bonding tape-wrapped layer and the surface of the cable insulating layer. Connection part.