JPH099450A - Insulator crosslinking treatment auxiliary device and crosslinking treatment device - Google Patents

Abstract

PURPOSE: To make it possible to pressure uniformly on an insulator by covering the insulator to place a form maintaining metal fixture, and placing an auxiliary device equipped with a flexible enclosed body storing a fluid filler between the form maintaining metal fixture and insulator. CONSTITUTION: When crosslinking treatment of an insulator of a synthetic resin material provided by covering a power cable joint section 14 is performed, a form maintaining metal fixture 16 and an auxiliary device 17 provided between the form maintaining metal fixture 16 and insulator 15 are placed. The auxiliary device 17 is equipped with a bag-like enclosed body 19 having heat resistance and flexibility and filler 20 stored in the enclosed body 19 and higher than a fluidity shown by the insulator 15 at a crosslinking temperature. Accordingly, when compressive force is partially received through the enclosed body 19 between the insulator 15 starting to expand and form maintaining metal fixture 16, the filler 20 itself is so moved in the enclosed body 19 that a more wider space is filled therewith without constraining the deformation of the insulator 15, and uniform pressure is given to the insulator 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator and a shape-maintaining metal fitting that is disposed so as to cover the insulator when the insulator made of a synthetic resin material is placed around the connecting portions of the power cables. The present invention relates to an insulator cross-linking treatment auxiliary tool and a cross-linking treatment device arranged between the two.

[0002]

2. Description of the Related Art There is a so-called EMJ method or TMJ method as a method of protecting a connecting portion of a power cable with an insulator.
In the EMJ method, the conductors protruding from the cable insulating layer exposed by the terminal treatment of the cable are connected to each other in series via a compression connector. An insulator made of a synthetic resin material is molded so as to cover the compression connector. In the TMJ method, this insulator is formed by wrapping a tape made of a synthetic resin material.

In any case, the insulator made of a synthetic resin material formed to cover the compression connector is in an uncrosslinked state. This uncrosslinked insulator is integrated with the cable insulating layer exposed at the cable connection end by being subjected to a crosslinking treatment. After that, a waterproof treatment with a protective tape or the like is applied to cover the crosslinked insulator.

By the way, in order to firmly integrate the insulator and the cable insulating layer by the crosslinking treatment, it is necessary to apply an appropriate pressure to the insulator during the crosslinking treatment. Therefore, a shape maintaining metal fitting that covers the insulator is used for the cross-linking treatment of the insulator. The shape-maintaining metal fitting keeps the insulator heated to the cross-linking temperature in a predetermined shape and regulates the expansion of the insulator to exert the pressure necessary for cross-linking adhesion on the interface between the insulator and the cable insulation layer. Let

However, if there is an uneven gap between the insulator subjected to the cross-linking treatment and the shape maintaining metal fitting covering the insulator,
It is not possible to exert a uniform pressure on the insulator. This non-uniform pressure causes non-uniform coupling force between the two, which causes deterioration of electrical insulation characteristics and the like. Therefore, if there is a non-uniform void between the insulator undergoing cross-linking and the shape-maintaining metal member, in order to equalize the void, an insulating material such as EP cerbon tape is attached to the corresponding portion of the insulator. The material was wrapped for correction.

[0006]

However, such a partial tape winding operation leaves an undesired winding mark on the insulator in terms of electrical insulation. Further, the winding of the tape is a manual operation, and it is not easy to wind the tape around the proper portion of the insulator quickly and accurately. For this reason, there has been a strong demand for development of a technique for exerting a uniform pressure on the insulator when the insulator made of a synthetic resin material is disposed so as to cover the power cable connection portion.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a shape-maintaining metal piece which is arranged so as to cover an insulator when the insulator made of a synthetic resin material which is arranged so as to cover the power cable connecting portion is cross-linked, and a shape-maintaining metal piece of this shape. Place an aid between the retaining bracket and the insulator. This auxiliary tool includes a bag-shaped sealing body having heat resistance and flexibility, and a filler contained in the sealing body and having a fluidity higher than that of the insulator at least at a crosslinking temperature. Is characterized by.

[0008]

In the assisting tool according to the present invention, since the filler contained in the bag-shaped sealing body exhibits greater fluidity than the insulator at the crosslinking temperature of the insulator subjected to the crosslinking treatment, the insulating material which starts to expand. When a compressive force is partially applied between the body and the shape-maintaining metal via the sealing body, the filling material itself fills the void toward a wider void portion without restraining the deformation of the insulator. Move in the sealed body accordingly. As a result, the auxiliary tool properly fills the gap between the insulator and the shape maintaining metal fitting to be subjected to the cross-linking treatment without requiring complicated adjustment work. Substantial pressure is applied through the aid.

As the sealing body, various thin film materials having heat resistance that can withstand the crosslinking temperature of the insulator and proper flexibility can be used. One of such thin film materials is a heat shrinkable thin film material made of, for example, a silicon resin material. A tubular thin film made of this silicone resin material can be formed into a bag shape in accordance with the lamination, and this can be used as a sealed body.

The filler contained in the sealing body is a material that exhibits higher fluidity than the insulator at the cross-linking temperature of the insulator. As such a material, for example, ethylene-acetic acid copolymer (EVA) is used. ), Ethylene-ethyl acrylate copolymer (EEA), and solid paraffin. Such a filler has a melting point of 120 degrees or less and a fluidity of 1 in the molten state.
It is desirable that it exceeds.

[0011]

The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 is a vertical sectional view showing a part of a crosslinking treatment apparatus according to the present invention. The crosslinking apparatus 10 according to the present invention is
A CV power cable 11, for example connected in series with each other,
Used to form 11 connections.

CV power cables 11 connected to each other,
11 is end-processed so that the insulating layer 12 made of cross-linked polyethylene is exposed at the ends to be connected and the conductor 13 is sequentially exposed from the tip of the insulating layer 12, and they are abutted against each other. The conductors 13 are connected to each other by crimping the compression connector 14.

An insulator 15 is formed so as to cover the compression connector 14. The insulator 15 covers the compression connector 14 from the central portion having a uniform outer diameter and the corresponding C from the both ends thereof.
The V power cable 11 is provided with tapered both ends that extend outward along the insulating layer 12 of the V power cable 11. This insulator 15
In the EMJ method, is formed by molding a synthetic resin material such as uncrosslinked polyethylene. Further, in the TMJ method, this insulator 15 is formed by wrapping a tape of a similar uncrosslinked synthetic resin material.

The uncrosslinked insulator 15 is subjected to a crosslinking treatment for integration with the insulating layer 12, and the crosslinking treatment apparatus 10 according to the present invention is used for the crosslinking treatment of the insulator 15. The cross-linking processing device 10 includes a tubular shape maintaining metal fitting 16 arranged over the insulator 15, an auxiliary tool 17 arranged between the shape maintaining metal fitting 16 and the insulator 15, and a bridging pot 18. Equipped with.

The auxiliary tool 17 has a tubular shape that entirely covers the insulator 15, has an inner layer portion 19A and an outer layer portion 19B, and defines a tubular airtight chamber 19C between them, and an airtight chamber 19C. And a filler 20 enclosed therein.

The sealing body 19 is a sealing material having heat resistance and flexibility to withstand the crosslinking treatment temperature of the insulator 15, and
For example, it is made of a silicone resin material. In addition, the filler 20
Is a material that exhibits higher fluidity than the insulator 15 at the crosslinking temperature of the insulator 15. Examples of such materials include ethylene-acetic acid copolymer (EVA), ethylene-
High fluidity polyolefin resin materials such as ethyl acrylate copolymer (EEA) and solid paraffin are available. It is desirable that such a filler 20 has a melting point of 120 degrees or less and a fluidity of more than 1 in the molten state.

The sealing body 19 includes two heat-shrinkable silicone resin tubes 19A and 19B and both tubes 19A and 19B.
And a sealing tape 21 for sealing both ends of the. First, the heat-shrinkable silicone resin tube 19A that constitutes the inner layer portion
And so as to cover the insulating layer 12 near the edge and
This tube 19A is appropriately heated and brought into close contact with the insulator 15. A linear or tape-shaped filler 20 made of, for example, a highly fluid olefin resin material is wound around the outer peripheral surface of the tube 19A. The heat-shrinkable silicone resin tube 19B forming the outer layer portion is arranged so as to cover the filling material 20, and is appropriately heated to shrink. Then both tubes 1
Both ends of 9A and 19B are sealed with sealing tape 21. As a result, a bag-shaped sealing body 19 that encloses the insulator 15 and seals the filling material 20 inside, that is, an auxiliary tool 17
Can be arranged.

After arranging the auxiliary tool 17, the auxiliary tool 17
The tubular shape maintaining metal fitting 16 is arranged so as to surround the insulator 15 via the. As is well known in the art, the shape-maintaining metal member 16 is assembled in a tubular shape with its halves having semicircular cross sections facing each other, and has a heating means (not shown) incorporated therein.

With the shape-maintaining metal fitting 16 and the auxiliary tool 17 assembled, the connection portion of the CV power cable 11 is arranged in a bridging pot 18 in which an atmosphere of an inert gas such as nitrogen gas is conventionally well known. It In the inert gas atmosphere in the bridging pot 18, the insulator 15 is heated to the bridging temperature by the heating means incorporated in the shape maintaining fitting 16.

When the insulator 15 is heated, the filler 20 enclosed in the airtight chamber 19C of the sealing body 19 of the auxiliary tool 17 is also heated. The filler 20 has a higher fluidity than that of the insulator at the crosslinking temperature. Further, the sealing body 19 that accommodates the filling material 20 exhibits flexibility. Therefore, the heated insulator 15 begins to expand, and the insulator 1
When the filler 20 partially receives a compressive force between the insulator 15 and the shape maintaining metal fitting 16 through the sealing body 19 due to the expansion of No. 5, the filler 20 itself restrains the deformation of the insulator 15. Instead, it moves in the sealing body 19 to fill the void toward a wider void portion.

Therefore, the assisting tool 17 properly fills the gap between the insulator 15 and the shape maintaining metal fitting 16 to be subjected to the cross-linking treatment without restraining the deformation of the insulator 15, so that the gap can be corrected. It is possible to apply a substantially uniform pressure to the outer peripheral surface of the insulator 15 during the crosslinking process of the insulator 15 without requiring a complicated adjustment work such as a tape winding work. As a result, the pressure required for cross-linking adhesion can be applied to the interface between the insulator 15 and the cable insulating layer 12 almost evenly, and the insulating tape can be insulated without leaving a trace of the correction tape on the surface of the insulator. The body 15 and the cable insulating layer 12 can be homogenously bonded to each other, and an electric connection portion having excellent electric insulation characteristics can be formed relatively easily.

During the cross-linking treatment of the insulator 15, the cross-linking pot 18
However, it is desirable to carry out the crosslinking treatment in an inert gas atmosphere as described above in order to increase the pressure resistance of the electrical connection portion. Further, although the example in which the heating means is incorporated in the shape maintaining metal fitting 16 has been described, the heating means can be separated from the shape maintaining metal fitting 16.

The present invention is not limited to the above embodiments. Although the present invention has been described by using the EMJ method and the TMJ method as examples, the present invention is not limited to this, and an uncrosslinked or semi-crosslinked insulator made of a synthetic resin material is preliminarily molded in a factory, and this premolded insulator is used at a cable connection site. So-called B cross-linked with
It can also be applied to the MJ method. Further, as the sealing body, a sheet material having appropriate heat resistance and flexibility can be appropriately selected, and by enclosing the filling material in the sealing body in advance, the filling material can be liquid at room temperature. Presenting materials can also be used.

[0024]

In the above-described auxiliary tool of the present invention, the filler contained in the bag-shaped sealed body and having higher fluidity than the insulator at the crosslinking temperature of the insulator starts to expand by the crosslinking treatment. If a compressive force is partially applied between the insulator and the shape-maintaining metal via the sealed body, the sealed body will be filled with the void toward the wider void without restraining the deformation of the insulator. Since it moves, the assisting tool properly fills the gap between the insulator subjected to the cross-linking treatment and the shape-maintaining metal fitting, so that the insulator receiving the cross-linking treatment exerts a substantially uniform pressure through the assisting tool. receive.

Therefore, according to the auxiliary tool of the present invention, an insulator and a cable can be obtained without requiring a complicated adjustment work as in the prior art and without leaving a tape winding mark which causes a reduction in electrical insulation. The pressure required for cross-linking adhesion can be applied to the interface with the insulating layer almost uniformly. Further, according to the crosslinking treatment device of the present invention including this auxiliary tool, it is possible to relatively easily form the electrical connection portion having excellent electrical insulation characteristics by achieving the uniform bonding between the insulator and the cable insulating layer. You can

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a part of a crosslinking treatment apparatus according to the present invention.

[Explanation of symbols]

 10 Cross-linking processing device 11 Power cable 15 Insulator 16 Shape maintaining metal fitting 17 Auxiliary tool 19 Sealing body 20 Filling material

Claims (3)

[Claims] 1. An auxiliary tool, which is arranged between the insulator and a shape-maintaining metal member which covers the insulator when the insulator made of a synthetic resin material is arranged to cover the power cable connecting portion. And a bag-shaped sealing body having heat resistance and flexibility that withstands the crosslinking treatment temperature of the insulator, and a fluidity exhibited by the insulator at least at the crosslinking temperature of the insulator, which is housed in the sealing body. An auxiliary tool for insulation-linking treatment of a cable connecting portion, which is provided with a filler having higher fluidity. 2. The cable connecting portion according to claim 1, wherein said filler is a solid at room temperature, and is made of a high fluidity polyolefin resin material having a melting point of 120 ° C. or less and a fluidity in the molten state thereof exceeding 1. Auxiliary tool for insulator cross-linking treatment. 3. A shape-maintaining metal piece arranged to cover the insulator when the insulator made of a synthetic resin material is arranged to cover the power cable connecting portion, and a shape-maintaining metal piece and the insulator. An auxiliary tool disposed between the auxiliary tool and the auxiliary tool, the auxiliary tool having a bag-like sealing body having heat resistance and flexibility to withstand the crosslinking treatment temperature of the insulator and housed in the sealing body; And a filler having a fluidity higher than that of the insulator at a cross-linking temperature of the body,
Bridge processing equipment for cable connection.