JPS6031171B2 - Cable connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cable connection section, and particularly to a water inspection structure thereof.

For example, the connection section of a cross-linked polyethylene power cable is equipped with an insulating reinforcement consisting of a rubber insulating tube provided across the cable conductor connection section and the cross-linked polyethylene cable insulation on both sides, and a waterproof insulation tube is provided on top of this reinforcement. It was wrapped in tape.

However, with this structure, if the waterproof tape is wrapped insufficiently, water can easily penetrate into the joints, and especially if the insulation of the joints is rubber-based, if water penetrates over a long period of time, the insulation will deteriorate. There were drawbacks. Recently, it has been proposed that power cables have a launching layer of metal film to prevent water from entering in any direction along the diameter of the cable, and it is required to prevent water from entering from the connection part. ing. On the other hand, inside the cable connection, it is necessary to connect the shielding layers of the power cables on both sides with a bind wire, but conventionally the bind wire is wrapped around the insulation reinforcement before applying water shielding treatment to the cable connection. The workability was poor. An object of the present invention is to provide a cable connection part that can effectively prevent water intrusion and does not require the attachment of a bind wire. Embodiments of the present invention will be described in detail with reference to the drawings.
The drawing shows a cable connection 10 according to the invention, in which the two power cables 12, 12' to be connected are cable conductors 1
4. The cable insulator 16, the shielding layer 18, the cable water shielding layer 20 made of a metal film, and the sheath 22 are stripped in stages, and the cable conductors 14 are interconnected with conductor connecting pipes 24 to form the cable. A conductor connection portion 26 is formed.

An insulating reinforcing body 28 made of a rubber insulating cylinder is placed over the cable conductor connection part 26 and the cable insulators 16 on both sides thereof so as to cover them. Cable connection part 1, insulation reinforcing body 28 and cable water shielding layer 2 on both sides
A laminate sheet water-shielding layer 32 is provided over the laminate sheet water-shielding layer 32, and a protective layer 34 is provided on the laminate sheet water-shielding layer 32 and covering the sheaths 22 of the power cables 12, 12'. .

The laminate sheet water-blocking layer 32 is made of a laminate tape in which conductive rubber or thermoplastic plastic is laminated on one or both sides of a thin metal sheet such as lead or aluminum; It is formed by wrapping the edge greens so that they overlap each other so that the layers are on the inside, and then heat-sealing or gluing the overlapped portions.

In this way, water intrusion from the direction of the connecting portion is prevented, and since the laminate sheet water-shielding layer is connected to the two water-shielding layers of the cable, the water-shielding property is maintained over the entire length of the cable line. Furthermore, the conductive rubber or plastic layer of the laminate tape is in contact with the shielding layer 18 of the cable, so that the shielding layer 18 of the two power cables 12, 12' is electrically conductive by the conductive rubber or plastic layer of the laminate tape. The laminate sheet water-blocking layer also acts as a shielding layer for the connection area. still,
In the illustrated embodiment, the water barrier layer 32 is the sheath 2 of the power cable.
2, but if the cable water shielding layer 20 is not exposed from the end of the sheath 22, the cable water shielding layer 32 can be extended to the sheath 22 in this way. This is advantageous because it can straddle two layers.

The protective layer 34 is made of a heat-shrinkable tube having an adhesive layer or an adhesive layer on its inner surface, and the laminate sheet water-shielding layer 32 and the power cable 12 are bonded together by heating and shrinking the heat-shrinkable tube.
12' and the sheath 22, water is prevented from flowing parallel to the axial direction through these interfaces.

In a specific example of the cable connection part of the present invention, the laminate sheet water-shielding layer 32 is made of a laminate tape in which conductive plastic or rubber with a thickness of 0.1 rib is laminated on both sides of a lead sheet with a thickness of 10 to 50 m, This laminate tape was wrapped with a wrap width of 5 to 2 wraps.

It was confirmed that in this case, the amount of water permeation in the radial direction of the connection portion was reduced to 1/1000 to 1/10,000 times compared to the case of using only the heat-shrinkable tube. In addition, the laminate sheet Ryusui layer 32 is formed in advance into two parts, etc. outside of the wrapping of the tape, and is attached to cover the insulation reinforcing body and the cable shielding layer, and the joint part of the mold is heat-sealed. Alternatively, it can also be formed by adhesion.

In the above embodiment, the insulation reinforcement 28 is in direct contact with the cable insulation 16, but a spacer may be provided between them.

In the drawings, reference numeral 36 indicates a semi-conductor provided on the inner circumferential surface of the insulating reinforcing body. According to the present invention, as described above, the water-shielding property of the cable connection portion can be significantly improved by the laminate sheet water-shielding layer formed across the cable water-shielding layer, thereby preventing insulation deterioration of the cable connection portion. In addition, the conductive rubber or plastic layer of the laminate sheet water shielding layer is connected between the cable shielding layers and functions as a shielding layer at the cable connection part, so the conventional binding wire can be omitted and work efficiency is improved. can be improved.

[Brief explanation of the drawing]

The drawing is a sectional view of a cable connection part according to the invention. 10... Cable connection part, 12, 12'...
...String force cable, 14...Cable conductor,
16... Cable insulator, 18... Cable shielding layer, 20... Metal water shielding layer, 22...
... Sheath, 26 ... Cable conductor connection part, 28 ... Insulation reinforcement, 32 ... Fuminate sheet water-blocking layer, 34 ... protective layer.

Claims (1)

[Scope of Claims] 1. A cable having a cable conductor, a cable insulator provided thereon in sequence, a cable metal water shielding layer, a shielding layer, and a sheath, spanning the cable conductor connection part and the cable insulators on both sides thereof. In the cable connection section provided with an insulating reinforcement, a laminate sheet water-shielding layer of a thin metal sheet and a conductive rubber or conductive plastic sheet is provided over the insulation reinforcing body and the cable metal water-shielding layer on both sides thereof. is provided, the conductive rubber or conductive plastic sheet of the laminate sheet water-shielding layer is in contact with the shielding layer of the cable, and a protective layer is provided around the outer periphery of the laminate sheet water-shielding layer. Characteristic cable connection part. 2. The cable connection section according to claim 1, wherein the laminate sheet water-blocking layer is formed by wrapping a laminate tape having an adhesive layer. 3. The cable connection section according to claim 1, wherein the laminate sheet water-blocking layer is molded in advance. 4. The cable connection section according to claim 1, wherein the protective layer comprises a heat-shrinkable tube having an adhesive layer or adhesive layer on the inner surface and provided spanning the laminate sheet water-blocking layer and the sheath. .