JPS5858812A - Method of forming plastic insulated power cable connector - 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 The present invention relates to the formation of a plastic insulated cable connection, and more particularly to a method of forming a plastic insulation cable extrusion type connection having an external semiconducting layer edge cut. be.

As a means of connecting plastic insulated cables, such as cross-linked polyethylene insulated cables, a tape or sheet made of the same material as the cable insulator is wrapped around the cable conductor connection part, and the L is added. The so-called heat molding method, which is integrated by fusion, and the method where a specified mold is installed on the cable conductor connection part, and the same material as the cable insulator is extruded into the mold using an extrusion device. 6
There is an extrusion molding method, but if the cable to be connected is an ultra-high pressure cable of 154 KV or 275 KV class, the latter is more suitable in terms of reliability and electrical characteristics. .

For this reason, with the recent increase in the voltage of this type of cable, there is an urgent need to put the latter method into practical use, and its development is currently in progress.

On the other hand, in cable lines, there is a problem in that the voltage induced in the outer semiconducting layer increases as the distance increases, so a so-called insulated connection section that cuts off the outer semiconducting layer is required as a connection section. .

However, in the extrusion molding method described above, a means for making an insulated connection part has not yet been developed.

The present invention has been made in view of the above points, and includes:
The aim is to provide a method for manufacturing insulated connections in an extrusion molding process.

That is, the gist of the present invention is to provide a cable conductor with a mold in which four parts for forming external semiconductor (d-layer edge cutting protrusions) are formed in a 1M1 circumferential direction on the insulation reinforcing body surface (described later). Cover the connection part by extruding and filling the insulation material of the same quality as the cable insulator in the mold, and then cover the connection part of the cable conductor with an insulation reinforcing body with a protrusion for edge cutting of the external semiconducting layer. There is a method VC for forming a plastic insulated cable connection part, which is characterized by comprising the steps of: molding the insulation reinforcing body, and molding the outer semiconductive layer while leaving an edge cutting protrusion on the periphery of the insulation reinforcing body.

Specifically, as a means for forming the above-mentioned external semiconductive layer, for example, first, a semiconductive rubber glass nuck containing a crosslinking agent is extruded onto the periphery of the insulating reinforcement, or a semiconductive rubber containing a crosslinking agent is extruded onto the circumference of the insulation reinforcement.・Wrap plastic tape or apply semiconductive rubber/plastic paint containing cross-linking agent.
Alternatively, there is a method in which a heat-shrinkable rubber/plastic tube having a crosslinking agent mostly conductive is inserted through the tube, and then heated in air or an inert gas to crosslink it and bond it to the insulating reinforcing body.

Next, an example of the forming method of the present invention will be described with reference to the attached drawings.

First, as shown in FIG. 1, the cross-linked polyethylene insulated vinyl sheath-caple (hereinafter referred to as CV cable) to be connected is connected to the sheaths 2 and 2' of the cables i and 1' and the insulators 3 and 6.
', etc. are sequentially stripped off by predetermined sections at the ends, and then the exposed end conductors 4, 4 and the like are connected through a predetermined conductor connection pipe 5, and then the end conductors 4, 4' and the conductor connections are connected. An internal semiconducting layer 6 is provided on the circumference of the tube 5 .

The internal semiconductive layer 6 is preferably a molded product obtained by heat-treating a wrapped layer of a semiconductive polyolefin heat-shrinkable tube or a semiconductive polyolefin tube (or piece).

Next, a mold 8 having a recess 7 formed in its inner circumferential direction for forming a protrusion for cutting the outer semiconducting layer on the surface of the insulation reinforcing body (to be described later) is used to insulate the insulators 3, 3' of both cables. Place it over the cable conductor connection. The mold 8 is composed of two halves, and a heater 9 is placed on the periphery of the mold 8.
Equipped with:

A ram device 10 and an extruder 11 are directly connected to the mold 8, and the mold 8 is preheated to a predetermined temperature with a heater 9.

Next, using an extruder 11, a crosslinking agent-containing polyethylene insulating material 12 having the same quality as the cable insulator 3° 3' is extruded and filled into the mold 8. The extrusion filling is performed until the above +J'+112 overflows from the overflow hole 16 of the mold 8 and the ram device 10.

Next, the mold 8 is filled with polyethylene insulating material 12.
After the material is crosslinked by raising the temperature to a γ quality necessary for crosslinking, the mold 8 is cooled to solidify the paulownia material 12, thereby forming a predetermined outer semiconducting layer for edge cutting. The insulating reinforcement body 15 with the protrusion 14 is molded.

Next, the mold 8 is removed, and as shown in FIG. 2, the external semiconductor layer 16 is molded leaving the edge cutting protrusion 14'th on the periphery of the insulating reinforcing body 15. The outer semiconductor layer 16 is
It is formed by extruding polyethylene containing a crosslinking agent, then heating it in air or an inert gas to crosslink it, and bonding it to the insulation reinforcing body 15.
L.

Next, an insulating reinforcing layer 17 is provided around the edge cutting projection 140 to prevent surface flashing when abnormal voltage intrudes. Practically, the insulation reinforcing layer 17 is formed by hot molding a polyolefin insulation compound or by wrapping a polyolefin insulation tape.

Incidentally, FIG. 3 shows an example of a song according to the present invention. In order to prevent surface flashing of the edge cutting protrusion 14', it is preferable to lengthen the surface insulation distance of the relevant portion.

In view of this point, a four part 7' is provided on the inner surface of the mold 8', and a curvature part molded body 18 having a predetermined curvature is inserted into the four part 7'. As the curvature portion molded body 18, a half-split semiconductive rubber/plastic molded body or a metal molded body is used.

After molding the insulation reinforcing body 15', remove the mold 8', then remove it if the curved part molded body 18 is made of metal, or remove it as necessary if it is made of semiconductive rubber or plastic. Then, an outer semiconducting layer (not particularly shown) is provided in the same manner as in the previous embodiment.

According to the present clitoris formation method carried out in this manner.

By preparing a mold in which four parts for forming the protrusions for cutting the edge of the external semiconducting layer are formed in the inner circumferential direction of the mold itself, it is possible to easily manufacture a predetermined insulated connection part. can.

Moreover, the edge-cutting protrusion is an extrusion molded body like the insulation reinforcing body, and therefore not only has excellent electrical performance but also excellent reliability.

Thus, the present invention is accomplished using a slightly modified mold, and is therefore a very practical forming method.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams of one embodiment of the method for forming a plastic insulated cable connection portion of the present invention, and FIG. 3 is a diagram illustrating another embodiment of the method for forming a plastic insulated cable connection portion of the present invention. . 1.1': CV cable, 2.2': cable sheath,
3.3 Heat cable insulator, 4.4': Cable conductor, 5
: Conductor connection tube, 6: Internal semiconducting layer. 7: Four parts, 8: Mold, 9: Heater, 10: Ram assembly f
M, 11: Extruder, 12: Insulating paulownia wood, 13 Ni-Ku-Flo one hole, 14: Edge cutting protrusion, 15: Insulating reinforcement, 16: External semiconductive layer, 17: Insulating reinforcing layer,'I'I n sai 2D '730

Claims (1)

[Claims] 1. A mold having a recess formed in the inner circumferential direction of the insulating reinforcing body to form a protrusion for cutting the outer semiconducting layer on the surface of the insulation reinforcing body, which will be described later, is placed on the cable conductor connection part. a step of extruding and filling an insulating material of the same quality as the cable insulator into the mold to form an insulating reinforcing body with a protrusion for edge cutting of the external semiconducting layer over the cable conductor connection part; 1. A method for forming a glass insulating cape connection part, comprising the steps of: forming an external semiconducting layer while leaving a protrusion for edge cutting on the circumference of the body. 2. Either leave a protrusion for edge cutting on the circumference of the formed insulation reinforcement and extrude semiconductive rubber plastic containing crosslinking agent, or wrap semiconductive rubber/plastic tape containing crosslinking agent, or wrap semiconductive rubber/plastic tape containing crosslinking agent. Semi-conductive rubber
Apply plastic paint or contain crosslinking agent!
A 1"-conducting tube, silanac (inserted through a shrink tube, then heated in air or in an inert gas to crosslink it, and then applied to the insulation reinforcement) 2. A method of forming a flask insulating power goblet gauze as claimed in claim 1 so as to be bonded together to form an outer semiconducting layer.