JPH0251306A - Joint of rubber, plastic power cable - Google Patents

Abstract

PURPOSE:To facilitate cable joint work by applying a premold reinforcing insulator composed of non-bridged rubber, plastic material then thermally bridging the insulator and jointing a cable. CONSTITUTION:Conductors 2a, 2b of cables 1a, 1b are exposed then the conductor 2a of the cable 1a is inserted through the cable insertion port 3a of a premold reinforcing insulator 3 and pulled out from the other end. The reinforcing insulator 3 is formed of non-bridged rubber, plastic material with bridging agent into spindle shape. Upon insertion of the cable 1a into the reinforcing insulator 3, the conductors 2a, 2b are tightened through a conductor joint pipe 6 and a semi-conductor or metal conductor 7 is arranged therearound. The flange section 5a of high voltage shield electrode 5 and the metal conductor 7 are jointed then the outer face of the reinforcing insulator 3 is covered with an outer semi-conductive layer 8, thereafter it is heated through a heating means so as to fuse and bridge the reinforcing insulator 3 thus integrating the cables 1a, 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for connecting rubber pot plastic power cables with molded connections.

[Prior Art J] Conventionally, as a method for connecting the intermediate portion or terminal portion of rubber/plastic power cables such as cross-linked polyethylene cables, there has been a method in which a polyethylene tape containing a cross-linking agent is wound around the cable connection portion and heat-molded. Another known method is to attach a mold to the cable connection part, fill the mold with a polyethylene compound, and crosslink it by heating from the outside to form an insulation reinforcement.

[Problem to be solved by the invention 1 However, these methods not only require a lot of equipment and time for the connection work, but also require the experience and skill of the operator to obtain a good connection state. For example, in both of the above two methods, at the cable connection part, the cable insulator is formed into a pencil steel shape, and the centered conductor is wrapped in a sleeve. It is necessary to form an internal semiconductive layer on the sleeve, but performing such work requires a lot of time, considerable experience, and skill. Also.

The tape winding method requires transporting a tape winding machine to the work site, while the metal mold method requires transporting an extruder to inject the polyethylene compound into the mold, both of which require a large number of equipment. It is hard to say that this is a practical method.

[Object of the Invention] The object of the present invention is to eliminate the drawbacks of the above-mentioned conventional examples, to save equipment and manpower, and to create a rubber/plastic power cable that can be easily implemented without requiring skill or experience. The purpose is to provide a connection method.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to expose the conductors of rubber/plastic power cables to be connected, and then add a crosslinking agent after connecting the conductors with a conductor connecting pipe. A play-molded reinforcing insulator made of uncrosslinked rubber/plastic material with a built-in high-voltage shield electrode is deposited over the connection.1. This is a method for connecting a rubber/plastic power cable, characterized in that the reinforcing insulator is crosslinked by heating.

[Embodiments of the Invention] The method according to the present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a cross-sectional view of a cable connection section in which the rubber/plastic power cable connection method according to the present invention is implemented.

In this connection, conductors 2a of cables la, 1b,
2b are exposed respectively, and the pre-molded reinforcing insulator 3
Insert the conductor 2a of the cable la through the cable insertion port 3a and pull out the conductor 2a from the other end.The reinforcing insulator 3 is made of an uncrosslinked rubber/plastic material containing a crosslinking agent and is shaped like a spindle as shown in FIG. The central part is cylindrical, and cable insertion ports 3a and 3b are provided at both left and right ends, and a predetermined gap 4 is created between the inside and the cable 1 when the cable is inserted. A metal high-voltage shield electrode 5 having a ring-shaped flange portion 5a on the cylindrical inner surface is embedded inside the reinforcing insulator 3.
Only this flange portion 5a is exposed from the inner wall surface of the reinforcing insulator 3.

After the cable 1a is inserted into the reinforcing insulator 3, the conductors 2a and 2b are fastened and connected by a conductor connecting tube 6, and a semiconductive material or a metal conductor 7 is provided around the conductor connecting tube 6. Next, a spacer for diameter adjustment (not shown in FIG. 1) made of uncrosslinked rubber/plastic material to which a crosslinking agent has been added to fill the voids 4 is attached around the cables la and lb, and then reinforced. The insulator 3 is moved to accurately connect the flange portion 5a of the high voltage shield electrode 5 and the metal conductor 7. Then, the outer surface of the reinforcing insulator 3 is covered with an outer semiconducting layer 8, and then heated by an appropriate heating means.
The reinforcing insulator 3 and the diameter-adjusting spacer are melted and crosslinked, and integrated with the cables la and lb.

As shown in FIG. 3, the metal conductor 7 for diameter adjustment and the spacer 9 may be formed in advance into a fitable half-shape and fitted with the conductor connecting pipe 6 and the cable 1, respectively. It is also possible to wrap it around the cable 1 etc. in the form of a tape or the like. Furthermore, the spacer 9 for diameter adjustment can be omitted by reducing the space 4.

If such a connection method is used, the high voltage shield electrode 5 is connected to the metal conductor 7 and has the same potential as the conductors 2a and 2b, for example, the interface S between the diameter adjusting spacer and the reinforcing insulator 3.
Even if there is a weak point in the area, the high voltage shield electrode 5 is completely embedded inside the reinforcing insulator 3 so that the high voltage region does not come into contact with the interface S. Destruction will no longer occur.

Note that a gap 4 exists between the cables 1a, 1b and the reinforcing insulator 3 so that the cable 1a or 1b can be inserted when inserted, but this gap is filled by inserting a spacer 9 and melting and cross-linking during heat molding. Since the part 4 disappears, it is not considered a defect. Also, the reinforcing insulator 3 can be formed from an uncrosslinked rubber/plastic material to which a crosslinking agent has been added in a controlled factory, etc., so it will not be considered a defect during the manufacturing process. There is also a very low possibility that defects will occur due to the contamination of foreign matter.

[Effects of the Invention] As explained above, the method for connecting a rubber/plastic power cable according to the present invention is a pre-molded reinforcement made of an uncrosslinked rubber plastic material to which a crosslinking agent has been added to the conductor connection portion of a rubber/plastic power cable. Since the cable is coated with an insulator and cross-linked by heating, the work is extremely easy without the need for skilled work such as forming the cable insulator into a pencil steel shape as in the past. Additionally, there is no need for equipment such as an extruder or tape winding machine, which saves equipment and manpower.Furthermore, by crosslinking uncrosslinked rubber and plastic materials, the reinforcing insulator can be completely integrated with the cable. Therefore, the insulation properties and durability are also improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for connecting rubber/plastic power cables according to the present invention, in which FIG. 1 is a cross-sectional view of a connecting part, FIG. 2 is a perspective view of a reinforcing insulator, and FIG. 3 is a view of a metal conductor and a spacer. FIG. Symbols 1a and 1b are cables, 2a and 2b are conductors, 3 is a reinforcing insulator, 4 is a gap, 5 is a high-voltage shield electrode, 6 is a conductor connection tube, 7 is a metal conductor, 8 is an external semiconducting layer, and the surface part be.

Claims (1)

[Claims] 1. After exposing the conductors of the rubber and plastic power cables to be connected and connecting the conductors with each other using a conductor connecting tube, a plate made of uncrosslinked rubber/plastic material with a crosslinking agent and a built-in high voltage shield electrode is attached. 1. A method for connecting rubber/plastic power cables, comprising: depositing a molded reinforcing insulator over the connection portion; and heating and crosslinking the reinforcing insulator.