JPS6114724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing intermediate connections for rubber-plastic cables.

In recent years, the length of power distribution cables has become longer, with examples of long routes extending over several hundred kilometers being seen. These long routes require more work to connect cables, and the construction period is becoming tighter, which affects the difficulty of workability in the work environment. For this reason, there is a need for a simple type of connection that can be manufactured in a short time without requiring any skill due to its simplified contents.

The conventional manufacturing method for cable intermediate connections involves stripping the cable ends, connecting the pencil-treated cables, and applying insulating tape while forming a stress cone to alleviate the electric field at the end of the outer semiconducting layer of the cable. This was accomplished by winding the wire, storing these insulating parts in a case, and filling the middle with a mixture.

However, as the connection area becomes relatively smaller as the voltage class becomes lower, these tasks require highly skilled workers to work alone, and the formation of stress cones by tape winding and cable penciling are difficult. This method requires extremely careful consideration because it affects the insulation performance of the cable, and has the disadvantage of requiring a large number of man-hours.

The present invention was made in view of the above situation, and an object of the present invention is to provide a method for manufacturing an intermediate joint for a rubber/plastic cable, which is easy to work, does not require skill, and can reduce the number of work steps. It is something.

The method of manufacturing an intermediate joint for a rubber/plastic cable according to the present invention includes the steps of: stripping the ends of the cables to be connected to each other, exposing the conductor ends, and attaching a conductor connecting pipe between the conductor ends; A step of attaching a split sleeve having approximately the same diameter as the outer periphery of the insulator between the outer periphery of the conductor connecting pipe and the end faces of the insulator on both sides formed approximately perpendicular to the axial direction of the conductor, and a step of attaching the split sleeve, the insulator, etc. A wound layer of tape with inner and outer layer surfaces having a dielectric constant greater than the outer layer surface is placed around the outer periphery between the shielding layers of both cables.
The method consists of a step of forming a high dielectric constant layer consisting of a high dielectric constant layer, and a step of attaching a case covering the high dielectric constant layer to both cable sheaths and filling the inside of the case with an insulating fluid.

By the way, the reason why a tape having inner and outer layer surfaces whose inner layer surface has a larger dielectric constant than the outer layer surface is used as the tape constituting the high dielectric constant layer in the above manufacturing method is as follows.

In other words, when attempting to confine the electric field around an electrode with an insulator, it is better to construct the entire insulator with the same material, that is, to construct the entire insulator with a single layer. If the electrode is composed of layers, the dielectric constant of which decreases from the inside to the outside, the electric field at the electrode surface can be made smaller, and therefore the dielectric breakdown starting voltage at the part concerned can be reduced accordingly. can be enhanced. On the other hand, this also applies to intermediate connections for rubber/plastic cables, and in view of this, in the present invention, in order to create a multilayer structure with different dielectric constants on the circumference of the split type sleeve (i.e., electrode), the above-mentioned method is adopted. A tape with inner and outer surfaces similar to the above was used.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of the method for manufacturing an intermediate joint for a rubber/plastic cable according to the present invention will be explained with reference to drawings.

First, the ends of the cables 13, 13 to be connected to each other are stripped, and the conductors 1, 1, insulators 2, 2, external semiconducting layers 3, 3, and shielding layers 4, 4 are exposed to appropriate lengths. These mutual conductors 1, 1 are electrically connected by a conductor connecting tube 6.

Next, the outer peripheral portion of the conductor connecting pipe 6 and the cable 1
3, 13 A split sleeve 7 having approximately the same diameter as the outer periphery of the insulators 2, 2 is provided between the end faces of the insulators 2, 2 on both sides having end faces formed substantially perpendicular to the axial direction, The surfaces between the two are made continuous by a split sleeve 7. Next, the split sleeve 7 and the insulators 2, 2 and the outer semiconducting layers 3, 3 are covered, and between the shielding layers 4, 4 on both sides, inner and outer layer surfaces are provided, the inner layer surface of which has a larger dielectric constant than the outer layer surface. A high dielectric constant layer 8 is formed by winding the tape and then heating it after winding the tape. Next, a case 9 is provided between the sheaths 5, 5 of the cables 13, 13 so as to house the high dielectric constant layer 8, and a case 9 is provided between the sheaths 5, 5 of the cables 13, 13.
An insulating spacer 14 is provided inside the case 9 with its inner circumferential side in contact with the high dielectric constant layer 8 and its outer circumferential side protruding to the outside of the case 9 .

A seal 1 is attached to the end of the case 9 in contact with the sheath 5.
0 is provided, and the relevant location is sealed, and further, the insulating fluid 1 is supplied from the fluid inlets 11, 11 in the case 9.
2 and fill it into the case 9.

The insulating fluid 12 filled in the case 9 includes:
A pressurized gas such as nitrogen, sulfur hexafluoride, or freon, or an insulating oil such as silicone or polybutene, or a mixture of urethane, epoxy, etc. is used.

Further, as the split sleeve 7, a molded body made of a material such as a rubber or plastic insulator, a foam, a semiconductor, a high dielectric constant material, or a metal is used.
In addition, when the conductor connection part is a large-sized connection part such as a large-sized conductor, the split type sleeve is made of a semiconducting material made of rubber or plastic material or a high dielectric constant molded material for ease of handling and weight reduction. use The use of these semiconductors and high dielectric constant materials significantly reduces the electric field at conductor connections. In addition, the only parts that are attached after connecting the conductor through the conductor connection tube are the split sleeve, high dielectric constant layer, and spacer, and the split sleeve and spacer use molded bodies, which greatly simplifies the work. be done.

In this way, in this example, the potential in the Cadel length direction is relaxed by a high dielectric constant layer, and the connection part is insulated in the radial direction by filling with insulating fluid, which eliminates the work that requires skill. That is, since there is no cable penciling work or creation of stress cones, the work is simple and easy, the number of man-hours can be significantly reduced, and the number of parts can also be reduced.

Furthermore, the high dielectric constant layer is formed by a wound layer of a tape having inner and outer layer surfaces whose inner layer surface has a larger dielectric constant than the outer layer surface, so that the dielectric constant of the high dielectric constant layer in the radial direction is higher than that of the inner layer. Since it is made small, it is effective in alleviating the electric field especially around the conductor connecting tube and near the end of the outer semiconducting layer of the cable.
By using a tape winding method for the high dielectric constant layer, the size of the cable conductor can be adjusted freely.

Furthermore, by providing a spacer in the center of the case, the inner peripheral surface of which is in contact with the high dielectric constant layer and the outer peripheral surface of which is in contact with the inner surface of the case, the mechanical strength of the case is increased and the linearity of the connection portion can be reliably maintained.

If the spacer is a solid type in which the case is divided into cable sides on both sides, different insulating fluids can be used for the cables on both sides.

That is, it has an effect that it can be applied to a simple type of different type of connection part, a basic configuration of a branch connection part, etc.

As described above, the method for manufacturing intermediate joints for rubber and plastics of the present invention is easy to operate and does not require skill, and can produce intermediate joints with excellent electrical characteristics while significantly reducing the number of man-hours. It can be said that its practical value is extremely large.

[Brief explanation of the drawing]

The figure is an explanatory diagram of an embodiment of the method for manufacturing an intermediate joint for rubber/plastic according to the present invention. DESCRIPTION OF SYMBOLS 1... Conductor, 2... Insulator, 3... External semiconducting layer, 4... Shielding layer, 5... Sheath, 6... Conductor connection tube, 7... Split type sleeve, 8... High dielectric constant Layer, 9... Case, 10... Seal, 11... Fluid inlet, 12... Insulating fluid, 13... Cable, 14... Insulating spacer.

Claims (1)

[Claims] 1. A step of stripping the ends of the cables that are connected to each other in stages to expose the conductor ends, and attaching a conductor connecting tube between the conductors, and forming a conductor connecting tube approximately perpendicular to the outer periphery of the conductor connecting tube and the axial direction of the conductor. A step of attaching a split sleeve having approximately the same diameter as the outer periphery of the insulator between the end faces of the insulator on both sides formed on the insulator, and a step of attaching the split sleeve, the insulator, etc., to the outer periphery between the shielding layers of both cables. forming a high dielectric constant layer consisting of a wound layer of tape with inner and outer layer surfaces having a dielectric constant greater than that of the outer layer surface, and attaching a case covering the high dielectric constant layer onto the sheaths of both cables; A method for manufacturing an intermediate joint for a rubber/plastic cable, which comprises the steps of filling the inside of the case with an insulating fluid. 2. The method of manufacturing an intermediate joint for a rubber/plastic cable according to claim 1, wherein a spacer is provided in the case, the inner circumferential side of which is in contact with the high dielectric constant layer, and the outer circumferential side of which is in contact with the inner surface of the case. 3. The method of manufacturing an intermediate joint for a rubber/plastic cable according to claim 2, wherein the outer peripheral side of the spacer is made to protrude to the outside of the case, and the inside of the case is divided into both cable sides.