JPS6015389Y2 - Rubber and plastic insulated cable connections - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in rubber and plastic insulated cable connections.

Conventionally, to form connections between rubber, plastic, or polyolefin insulated cables, the ends of the cables to be connected are sharpened with a pencil to expose the conductors, and the conductors are electrically connected using a connection sleeve such as a compression sleeve. Then, wrap a semiconductive tape around its outer periphery and heat-seal it, or cover it with a semiconductive heat shrink tube to form an internal semiconductive layer, and wrap an insulating tape made of crosslinked polyethylene or the like around the outside. Alternatively, an insulating layer is provided by extruding cross-linked polyethylene, and a connecting portion is formed by sequentially providing an external conductive layer protection layer using a semiconductive tape similar to that described above.

Additionally, if moisture intrudes into the insulator layer, a water tree phenomenon will occur and the electrical properties will be significantly degraded, so a water-blocking layer is provided on the outside of the external semiconducting layer to prevent moisture from infiltrating into the insulator layer. It is something.

That is, the water-blocking layer is formed by winding or vertically attaching a laminate tape made of metal such as copper, lead, or aluminum to which conductive rubber or plastic is adhered.

In this case, even if the laminate tape is wound under tension, the metal has poor elasticity, so it does not expand or contract, and the overlapping surfaces do not come into close contact with each other, making it difficult to integrate, and there is a problem in that moisture easily infiltrates from this overlapping portion.

The present invention has been made as a result of extensive research aimed at improving these drawbacks, and has resulted in the discovery of a cable connection structure that has excellent water-shielding properties.

That is, the present invention exposes the conductor at the terminal part to be connected, sequentially provides an inner conductive layer, an insulator layer, and an outer conductive layer on the outside of the conductor, and then coats the metal tape with conductive rubber or plastic tape on the outside. It is characterized by having a water-blocking layer made of an attached laminated tape and a reinforcing layer formed by winding an elastic tape made of rubber or plastic.

In the present invention, especially when winding a rubber or plastic elastic tape on the outside of a water-blocking layer made of a laminated tape, it is preferable to stretch the tape by a tensile tension of, for example, 20 to 30%. By doing so, pressing pressure is generated due to the stress when the tape contracts, and the laminated tapes adhere well to each other and are integrated, thereby sufficiently preventing water from seeping through the overlapped seams of the tapes.

Note that the metal tape used for metal-conductive rubber and plastic laminate tapes has a thickness of 0.01 to 0.1.
It is best to have a thickness of about rIWL, and if it is less than 0.01 mm, cracks may occur during shrinkage.

0.1 again? If it exceeds F171, heat shrinkability is inhibited and an excellent water-blocking layer cannot be formed.

Further, as the metal, AI, Pb, Cu, etc. are preferable, and Pb is particularly preferable from the viewpoint of corrosion resistance.

Rubber and plastic tapes include low, medium, and high density polyethylene, polypropylene, polybutene-1, polymethylpentene, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate-vinyl chloride graft copolymer, chlorinated polyethylene, and isoprene. Conductive tapes made of rubber, chloroprene rubber, acrylonitrilo-butadiene rubber, styrene-butadiene rubber, etc.

Further, in the present invention, the elastic tape used for the reinforcing layer provided on the water-blocking layer may be any ordinary rubber or plastic, such as polyvinyl chloride tape, ethylene propylene tape, chloroprene tape, butyl rubber tape, isoprene rubber tape, These include chlorosulfonated polyethylene tape, ethylene vinyl acetate copolymer tape, etc.

Next, one example of the present invention will be explained with reference to the drawings.

The terminal portion of the 154 kV CV600TrIIft was sharpened with a pencil to expose the conductor, and the conductors were electrically connected to each other using a compression sleeve.

Next, apply a semiconductor polyethylene compound (
Product name: HFDJ 0580 (manufactured by Nippon Unicar)) was extruded into a blown film with a thickness of 0.15 m, and a width of 2
- A semiconductive tape made into a tape by slitting is wound to a thickness of 2.0 yrvs and heat fused to form an internal semiconductive layer 2, and a crosslinkable polyethylene compound (product HFDJ 4201 (manufactured by Nippon Unicar) was extruded into a 0.125 mm thick inflation film, and an uncrosslinked polyethylene insulating tape made into a tape by cutting slits into a width of 2 mm was wound to a thickness of 28 wIL to form the insulating layer 3. Then, on that side, apply a semiconductive tape similar to the above to a thickness of 2. The outer semiconducting layer 4 was formed by winding the film in a direction of Orrrm.

After that, a 1/2-wrap tape made of conductive polyethylene (50 μm thick)/lead (50 gLrn thick)/conductive polyethylene (50 μm thick) sheet with slits cut into a width of 5 mm was wound around the outside in two layers to prevent water. A layer 5 is provided, and a thickness 1 is provided on the outside thereof.
．． 0 mm chloroprene rubber tape (Example (1)) or thickness 1. OMn butyl rubber tape (Example (2))
The reinforcing layer 6 was formed by winding the reinforcing layer 6 into a 1/2 wrap, thereby obtaining the cable connection portion of the present invention.

In order to compare with the cable connection part of the present invention, an inner semiconducting layer, an insulating layer and an outer semiconducting layer are provided on the outside of the conductor in the same way as above, and the cable connection part (comparative example (1)) and the outer semiconducting layer are A cable connection part (Comparative Example (2)) was made by providing only a water-blocking layer similar to that in the Example on the outside of the cable.

In order to test the water-shielding performance of these cable connections, the cables were immersed in warm water at 90°C for 30 days, and the amount of water that had penetrated into the insulators after immersion was measured using a solid moisture meter manufactured by DuPont. .

The results are shown in Table 1.

As detailed above, according to the structure of the cable connection part of the present invention, the amount of moisture that infiltrates into the insulator is extremely small, so water trees in the insulator due to moisture do not occur, and it has excellent electrical properties over a long period of time. It is something.

[Brief explanation of the drawing]

The drawing is a sectional view showing an example of the rubber/plastic insulated cable connection part of the present invention. 1... Conductor, 2... Internal semiconducting layer, 3
...Insulator layer, 4...Outer semiconducting layer,
5...Waterproof layer, 6...Reinforcement layer.

Claims (1)

[Scope of utility model registration request] The conductor at the terminal part to be connected is exposed, and an internal semiconductive layer, an insulating layer, and an external semiconductive layer are sequentially provided on the outside of the conductor, and then a conductive rubber or plastic tape is attached to the metal tape on the outside. A connection part for rubber and plastic insulated cables, characterized in that a water-blocking layer made of a laminated tape and a reinforcing layer made of a rubber or plastic elastic tape are provided.