JP2000059976A - Crosslinked polyethylene insulator type connective portion of power cables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the execution time of the connective portion of the conductors of power cables and improve its electric characteristic, by winding on it a tape made of an uncrosslinked-ethylene-polypropylene rubber containing a crosslinking agent, and by molding it thereafter to form a reinforced insulator. SOLUTION: Conductors 1 of cables subjected to pick finding and stage-form peeling are connected compressively with each other by a conductor connecting tube 2, a semiconductive tape is wound in a wrapping way over the conductor connecting tube 2 and the end portions of respective inner semiconductive layers 3 of both the cables or a semiconductive shrinkable tube is mounted thereon to form an inner semiconductive layer 6 of the connective portion of the cables. It is wound with a tape made of an uncrosslinked-ethylene-polypropylene rubber containing a crosslinking agent, the tube is molded thereafter to form a reinforced insulator 7. Still, when molding the tape, a metallic mold is mounted on the tape to form the reinforced insulator 7 by crosslinking the uncrosslinked-ethylene-polypropylene rubber. Further, a semiconductive fusible tape is wound over the reinforced insulator 7 and the end portions of respective outer semiconductive layers 5 of both the cables or mounting a semiconductive shrinkable tube thereon, an outer semiconductive layer 8 of the connective portion of the conductors 1 of the cables is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a connection portion of a CV cable. In particular, the present invention relates to a connection portion of a CV cable in which a non-crosslinked ethylene propylene rubber tape containing a crosslinking agent is wound and then molded to form a reinforcing insulator for the connection portion.

[0002]

2. Description of the Related Art In general, a crosslinked polyethylene insulated power cable (hereinafter referred to as CV) used for power transmission and distribution at a high voltage or higher.
Cable) is connected to the conductors of both CV cables, inner semiconductive layer, cross-linked polyethylene insulator, outer semiconductive layer,
The metal shielding layer and the cable sheath are formed into a predetermined shape.

[0003] Thereafter, as shown in FIG. 4, the cable conductor 1 is compression-connected by a conductor connection tube 2, and a semiconductive layer 6 is applied to the surface of the conductor 1 and the conductor connection tube 2. Further, a reinforcing insulator 17 is formed on both cable insulators 4 to insulate them. After the outer semiconductive layer 8 is formed on the outer peripheral surface of the reinforcing insulator 17, the entire connecting portion is covered with a protective body.

As a method of forming the reinforcing insulator, a method of winding a self-fusing rubber tape (tape joint),
A method in which an uncrosslinked polyethylene tape containing a crosslinking agent is wound and then molded (TMJ), a method in which an uncrosslinked polyethylene resin containing a crosslinking agent is extruded and then molded (EMJ) are employed.

[0005]

The above-mentioned tape type joint is widely used for a 66 to 77 kV class CV cable because of its short construction time and excellent cost. However, this joint is low in reliability in terms of insulation performance because the tapes are simply adhered to each other with an adhesive layer, and it has been difficult to apply this joint to a CV cable of 154 kV class or more.

[0006] The method of forming a connecting portion reinforcing insulator of a 154 kV class or higher requires the above T
MJ has been adopted. However, in this method, since the insulation performance is affected by the cleanness of the construction environment, it is necessary to install a clean room or the like as a clean measure.
In addition, since the heating and cooling must be controlled during molding, a long continuous molding time is required. Therefore, short-time split construction (7 hours / day) was impossible.

On the other hand, although the electrical characteristics of a tape-wrapped mold joint made of ethylene propylene rubber (hereinafter referred to as EPR) are slightly inferior, there is no significant decrease in the electrical characteristics with respect to inclusion of foreign matter. There is an advantage that cooling during molding is unnecessary and the working time is short.

In view of the above points, the present invention provides a CV capable of improving the electrical characteristics of a connection part by reducing the maintenance of the construction environment and shortening the construction time in connecting the CV cable.
It is intended to provide a connection for a cable.

[0009]

SUMMARY OF THE INVENTION The present invention provides a CV
The connection portion of the cable is characterized in that a non-crosslinked ethylene propylene rubber tape containing a crosslinker is wound around a conductor connection portion, and then molded to form a reinforcing insulator.

[0010] The connecting portion of the CV cable is formed by covering a conductor connecting portion with a preformed uncrosslinked ethylene propylene rubber molded article containing a crosslinking agent, and then molding to form a reinforcing insulator. It is characterized by becoming.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a CV illustrating an embodiment of the present invention.
FIG. 4 is a partial vertical cross-sectional view of a cable connection portion. In the figure, the conductor 1 of the cable stripped at the exit step is compression-connected by a conductor connection tube 2, and a semiconductive tape is wrapped over the conductor connection tube 2 and over the distal end portions of both cable inner semiconductive layers 3. Then, a semiconductive shrink tube is covered to form a semiconductive layer 6 inside the connection portion. In addition, claim 1 of the present invention
In the embodiment, a non-crosslinked ethylene propylene rubber tape containing a crosslinker is wound and then molded to form a reinforcing insulator 7.
To form At the time of molding, a metal mold is attached and the reinforcing insulator 7 is formed by being cross-linked. Further, a semiconductive fusing tape is wrapped around the reinforcing insulator 7 and over the distal end portions of both cable outer semiconductive layers 5 or a semiconductive shrinkable tube is covered to cover the outer half of the connection part. The conductive layer 8 is formed. On this, a shielding layer, a protective tube, a waterproof layer, etc. (not shown) are applied to complete the connection work.

According to the second embodiment of the present invention, the conductors 1 of the two cables are compression-connected by the conductor connection tube 2 as in the connection procedure described above, and the connection portion internal semiconductive layer 6 is placed thereon.
Then, as shown in FIG. 2, an uncrosslinked EPR molded body containing a crosslinking agent previously produced in a factory as shown in FIG. The uncrosslinked EPR molded article containing the crosslinking agent is vertically oriented as shown in FIG.
A divided mold or a combination of a cylindrical integral molded body 11 shown in FIG. 2 (B) and a vertically divided molded body 12 shown in FIG. 2 (C).

Before connecting the conductors 1 of both cables, it is necessary to pass through the one-piece cylindrical molded article 11 through one of the cables. After the connection processing of the conductors 1 of both cables is completed, first, a molded body 12 divided into two parts as shown in FIG. The molded body 11 is attracted and covered.

After the reinforcing insulator 7 is formed, it is the same as that described with reference to FIG.

[0015]

As described above, the present invention has the following effects.

(1) Cooling is not required when molding the EPR reinforcing insulator, so that molding can be performed in a short time.
Work time can be greatly reduced.

(2) Since a mold joint using EPR does not require environmental maintenance, the construction time for environmental maintenance can be shortened.

(3) Since the reinforcing insulator is manufactured in the factory in advance, the tape winding work on site is not required, so that the working time can be shortened.

(4) Since the reinforcing insulator is manufactured in the factory in advance, foreign substances and voids inside the reinforcing insulator can be reduced, and an improvement in electrical performance can be expected.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a cross-linked polyethylene insulated power cable connecting portion according to the present invention.

FIG. 2 is an explanatory view of a non-crosslinked ethylene propylene rubber molded article containing a crosslinking agent, which is manufactured in a factory in advance according to the present invention;
(A) shows a molded body divided into two in the vertical direction, (B) shows an integral cylindrical molded body, and (C) shows a molded body divided into two in the vertical direction.

FIG. 3 is an explanatory view showing that a reinforced insulator is obtained by combining the integral molded body of FIG. 2 (b) and the vertically divided molded body of FIG. 2 (c).

FIG. 4 is a partial longitudinal sectional view illustrating a conventional cross-linked polyethylene insulated power cable connection portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Conductor 2 Conductor connection pipe 3 Cable inside semiconductive layer 4 Cable insulator 5 Cable outside semiconductive layer 6 Connection inside semiconductive layer 7,17 Reinforcement insulator 8 Connection outside semiconductive layer 10 Prefabricated cross-linking agent Non-crosslinked EPR molded article containing cross-linking agent (split type) 11 Uncrosslinked EPR molded article containing pre-fabricated cross-linking agent (integral type) 12 Non-crosslinked EPR molded article containing pre-fabricated cross-linking agent (split type)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kazuo Ogawa 42-1 Shintomi, Futtsu-shi, Chiba F-term in Fujikura Futtsu Plant (reference) 5G375 AA02 BA26 BB45 BB46 BB90 CA02 CB03 CB04 CB05

Claims (2)

[Claims] 1. A connecting portion of a cross-linked polyethylene insulated power cable formed by winding an insulating tape on a conductor connecting portion and molding the insulating tape to form a reinforcing insulator. A cross-linked polyethylene insulated power cable connection portion comprising a non-crosslinked ethylene propylene rubber tape wound with an agent and molded to form a reinforcing insulator. 2. A cross-linking method comprising: forming a non-cross-linked ethylene propylene rubber molded article containing a cross-linking agent prepared in advance around a conductor connection portion; and molding the molded article to form a reinforcing insulator. Polyethylene insulated power cable connection.