JPH0984237A - Protection method of connected part of power cables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relieve a stress on a connected part of power cables and to prevent an external flaw thereof by forming a cushion layer by winding a flexible tape or sheet around the connected part after the power cables are connected temporarily. SOLUTION: After power cables are connected temporarily, a cushion layer 5 is formed by winding a flexible tape or sheet around the connected part thereof and then the layer is made to shrink by putting a shrink tube 6 on the outer periphery thereof. In this case, the structure of the connected part is so made that the cushion layer 5 and the shrink tube 6 cover the whole of an insulator connecting part 1, insulators 2 and metal sheaths 3 between corrosionproof layers 4 on the opposite sides and that the opposite ends of the cushion layer 5 and the shrink tube 7 cover the corrosionproof layers 4. Accordingly, the connected part with protection between the corrosionproof layers 4 is held entirely in the shrink tube 6. As the result, a mechanical stress is relieved and also an external flaw can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying a power cable that has been replenished in advance, and more particularly to a method for protecting a power cable connecting portion that relieves stress on the connecting portion and prevents external damage.

[0002]

2. Description of the Related Art When laying a power cable, a long power cable wound around a drum is carried to a construction site,
It has been generally practiced to extend the electric power cable from the drum and lay it. The power cable is wound around a drum in advance at a factory or the like, and is formed into a long length by sequentially connecting relatively short ones. In the factory, when making this connection, first connect the cable conductor in the center of the power cable, connect the insulator on its outer periphery, then weld and cover the metal sheath, and further coat the anticorrosion layer on it. Is common. The state of this connecting portion is a completed state and can be laid as it is.

[0003]

However, in the above-mentioned conventional connecting method, stress may be applied when the power cable is wound around the drum or when the wire is laid, and each part of the connecting portion may be damaged.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method of protecting a power cable connecting portion which solves the above problems, reduces stress on the connecting portion, and prevents external damage.

[0005]

In order to achieve the above object, the present invention has a method in which power cables are temporarily temporarily connected in advance in a factory or the like to form a long cable, and the power cable is wound around a drum and carried to a construction site. , When the power cable is extended from the drum and installed, after connecting the power cable to the cable conductor and the insulator on the outer periphery thereof, wind a flexible tape or sheet around the connection portion. To form a cushion layer.

After the cushion layer is formed, the outer circumference thereof may be covered with a shrink tube to shrink the cushion layer.

A foamable material may be used for the tape or sheet.

With the above structure, since the cushion layer is formed around the connection portion, when the power cable is wound around the drum or when the wire is extended, mechanical stress on the connection portion is alleviated, and Trauma is prevented.

The contraction of the contraction tube on the outer periphery of the cushion layer allows the cushion layer to be integrated with the power cable and prevents moisture from entering the connection portion.

By using a foamable material for the tape or sheet, the cushioning property is improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

According to the power cable connecting portion protection method of the present invention, after the power cable is temporarily connected, a flexible tape or sheet is wound around the connecting portion to form a cushion layer, and then the outer periphery thereof is formed. Shrink the tube with a shrink tube. FIG. 1 is a vertical cross-sectional view of a connection part (hereinafter referred to as a protected connection part) after these processes are performed.

As shown in the figure, in the structure of the connecting portion of only the power cable to be connected in a factory or the like, the insulator connecting portion 1 is provided so as to cover the connecting portion of the cable conductor (not shown),
The insulator 2 of the power cable is connected to both sides of the insulator connection portion 1, and the metal sheath 3 covering the outer periphery of the insulator 2 is further provided on both sides thereof. Both sides of the metal sheath 3 are covered with anticorrosion layers 4 on their outer circumferences.

The structure of the protected connection is the cushion layer 5
And the contraction tube 6 covers the insulator connection portion 1, the insulator 2 and the metal sheath 3 between the anticorrosion layers 4 and 4 on both sides, and both ends of the cushion layer 5 and the contraction tube 6 are the anticorrosion layer 4.
It is supposed to suffer from. Therefore, in the protected connection portion, the space between the anticorrosion layers 4 and 4 is entirely contained in the shrinkable tube 6.

A cross section of the protected connection is illustrated in FIG. This figure shows a cross section of the insulator connecting portion 1. As shown in the figure, the cable conductor 7 is arranged in the center, the insulator connecting portion 1 is provided on the outer periphery thereof, and the cushion layer 5 is further formed on the outer periphery thereof. The outermost periphery is composed of a shrink tube 6.

The cushion layer 5 is formed by winding a flexible tape or sheet as described above. Since the tape or sheet has flexibility, it can be easily wound and has excellent cushioning properties after winding. A foamable material can be used for this tape or sheet, and the cushioning property is further improved by using the foamable material. In addition, the cushion layer 5
A rubber or a semi-solid resin can also be used for.

The shrinkable tube 6 is a tube made of a shrinkable material, and its diameter can be reduced by shrinking it. Therefore, this shrink tube 6 having a required length is prepared in advance, one power cable is loosely covered when the power cable is connected, and after the connection, the shrink tube 6 is moved in the longitudinal direction and overlapped on the cushion layer 5. , Then let it shrink. As a result, the shrinkable tube 6 has a smaller diameter, and
As described above, the cushion layer 5 is tightly attached so as to be tightened. In this way, the cushion layer 5 is integrated into the power cable.

The method of protecting a power cable connecting portion of the present invention is carried out when the power cables are sequentially connected in advance in a factory or the like, and thus the power cable formed in a long length by sequentially providing the protected connecting portions. Is shipped around a drum. During the winding, since the cushion layer is formed around the protected connection portion, the mechanical stress on the protected connection portion is relieved and external damage is prevented.
Furthermore, this drum is carried to the installation site, and the power cable is extended from this drum and installed. Since the cushion layer is formed on the protected connection portion even during the laying of the extended wire, the mechanical stress on the protected connection portion is relieved and external damage is prevented.

Further, the close contact of the shrinkable tube 6 prevents the infiltration of water into the protected connection portion, and the waterproofing is achieved during the installation of the extended wire and after the installation.

After the installation, the shrinkable tube 6
The cushion layer 5 is removed, and the metal sheaths 3 and 3 and the anticorrosion layers 4 and 4 are respectively connected by a predetermined material to complete the connection of the power cable.

[0021]

The present invention exhibits the following excellent effects.

(1) When a power cable is wound around a drum or when a wire is laid, mechanical stress on the connecting portion is relieved and external damage is prevented.

(2) The contraction tube allows the cushion layer to be integrated with the power cable, and prevents moisture from entering the connection portion.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a connection portion processed by a protection method of the present invention.

FIG. 2 is a cross-sectional view of a connection portion processed by the protection method of the present invention.

[Explanation of symbols]

 1 Insulator connection part 2 Insulator 3 Metal sheath 4 Anticorrosion layer 5 Cushion layer 6 Shrink tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Suzuki 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Cable Co., Ltd. Hidaka factory

Claims (3)

[Claims] 1. When a power cable is temporarily connected in advance in a factory or the like to form a long length, the power cable is wound around a drum and carried to a construction site, and the power cable is extended from the drum and installed. In the method for protecting a power cable connecting portion, the power cable connecting portion is temporarily connected and then a flexible tape or sheet is wound around the connecting portion to form a cushion layer. 2. The method of protecting a power cable connecting portion according to claim 1, wherein after forming the cushion layer, a shrink tube is covered on the outer periphery of the cushion layer to shrink the cushion layer. 3. The method for protecting a power cable connecting portion according to claim 1, wherein a foaming material is used for the tape or the sheet.