JPH09140043A - Rubber molded part and method of finishing cable end - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new waterproof method which do not require a waterproof tube or flame, and rubber molded part therefor. SOLUTION: This rubber molded part has a stress cone 20 which is formed in one united body by both an insulating portion 21 made of an insulating rubber material and an extended portion 22 made of a conductive rubber material. The insulating portion 21 has a through-hole with the inner diameter equal to the outer diameter of a cable insulating body; and the extended portion 22 has a hole with the inner diajneter smaller than the outer diameter of cable sheath, and this extended portion can be folded up backward from the center of the length. Also, an end portion of a power cable is peeled off by one step, and a cable conductor 8, cable insulating body 5 and a metal shielding layer 6 are exposed partially, semi-conductive crosslinked-polyethylene tape is wound around the metal shield side and a metal shield layer of a cable insulated body 5 thereby forming a semi-conductive layer 24, the rubber mold stress cone 20 folded up backward on the cable insulating body 5 is inserted, and the cable insulating body and cable sheath 7 are covered by opening the folded portion in this forming method for the power cable end portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber molded part used for a terminal part of a power cable and a method of forming an end part of a power cable using the same.

[0002]

2. Description of the Related Art A typical configuration example of a conventional power cable terminal section is shown in FIG. That is, the tip of the power cable is stripped off to expose the cable conductor 8, the cable insulator 5, and the metal shielding layer 6 to predetermined dimensions. The terminal 1 is attached to the cable conductor 8 and the stress cone 2 which is a rubber molded component is attached on the cable insulator 5. A semiconductive layer is formed by winding a semiconductive fusion tape 3 from the end of the stress cone 2 to the shielding copper tape 6 which is a metal shielding layer, and shields the power cable and the semiconductive layer at the end of the stress cone 2. Are electrically connected to contribute to electric field relaxation. The semiconducting fusion-bonding tape 3 is formed so that the stress cone 2 and the cable sheath 7 are covered with a waterproof tube 4 so as to cover the semi-conductive fusion bonding tape 3 for waterproofing.

[0003]

In the terminal treatment section of the power cable having the above-mentioned structure, the heat-shrinkable waterproof tube 4 which is easy to work as a part used for waterproofing the terminal.
However, there is a safety problem because the waterproof tube 4 is formed by shrinking by applying heat from a burner or the like.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel waterproofing method that does not require a waterproof tube and does not use fire, and a rubber molded component for the method.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a stress cone in which an insulating portion made of an insulating rubber material and an extension portion made of conductive rubber are integrally formed, and the insulating portion is provided outside the cable insulator. A hole having an inner diameter is formed, a hole having an inner diameter smaller than the outer diameter of the cable sheath is formed in the extension portion, and the extension portion is a rubber mold component that can be folded back so as to be turned up from the center.
Also, strip the end of the power cable to remove the cable conductor,
The cable insulator and the metal shield layer are exposed, and a semiconductive crosslinked polyethylene tape is wound over the metal shield layer side and the metal shield layer of the cable insulator to form a semiconductive layer,
This is a method of forming an end portion of a power cable in which a folded rubber mold stress cone is inserted on a cable insulator and the folded portion is opened to cover the cable insulator to the cable sheath.

The end portion on the cable sheath side of the stress cone, which is a rubber molded component to be mounted to alleviate an electric field, is extended to sufficiently cover the cable sheath, and a hole having a size smaller than the outer diameter of the cable sheath is formed. , This end is stored in advance as a folded back extension, and is inserted into a predetermined position of the power cable end exposed in this state when the power cable end is created, and based on the extension folded back after the insertion. It is intended to be waterproof by opening it back and bringing it into close contact with the cable sheath.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of a rubber mold component of one embodiment. That is, the stress cone 20 which is a rubber mold component is integrally molded by connecting the interface between the insulating portion 21 formed of an insulating rubber material and the extension portion 22 of the conductive rubber material with a curved surface so as to alleviate an electric field. It is molded and manufactured. Since the insulating portion 21 is inserted into the cable insulator, a hole 21a is formed in the axial direction so as to match the outer diameter of the cable insulator. Further, the axial hole of the extension portion 22 is gradually expanded so as to have an inner diameter adapted to the outer diameter of the cable insulator, the semiconductive layer, the metal shielding layer and the cable sheath, respectively, in order to be fitted respectively. The holes 22a, 22b and 22c are formed, and the diameter of the hole 22c is formed smaller than the outer diameter of the cable sheath.

Next, a method of treating the end of the power cable using the stress cone 20 will be described. FIG. 2 is a cross-sectional view showing the configuration of the terminal processing unit of the power cable. That is, the end portion of the power cable is exposed by stripping the cable conductor 8, the cable insulator 5, the metal shielding layer 6 and the cable sheath 7 into a predetermined size. Then, a semiconductive crosslinked polyethylene tape is wound around the cable insulator 5 and the metal shielding layer 6 to form the semiconductive layer 24. In this way, the stress cone 20 in which the extension portion 22 is folded back
Is inserted and installed at a predetermined position on the cable insulator 5, and the extension 22 of the semiconductive material and the semiconductive layer 24 are brought into contact with each other to be electrically connected. Next extension 2
By opening the folded-back portion indicated by the dotted line 2 as shown in FIG. 3, the right side portion of the extension portion 22 is closely attached so as to cover the cable sheath 7, and the covering is completed. The terminal 1 is connected to the cable conductor 8 at the tip.

FIG. 2 shows a completed state in which the end portion of the stress cone 8 in the state of FIG. 1 is opened on the cable sheath 7. Since the inner diameter 22c of the end portion of the extension portion 22 of the stress cone 20 is formed to have a diameter smaller than the outer diameter of the cable sheath 7 in advance, it is difficult to insert it into the cable sheath 7 as it is. By folding this back and forming it, insertion becomes easy. Also, stress cone 2
The end of the extension portion 22 of 0 closely adheres to the cable sheath 7 and forms a good waterproof structure.

[0010]

As described above, according to the rubber mold component and the method for forming the cable end portion of the present invention, the power cable end processing can be safely performed without using any fire in the power cable end processing. The waterproof structure can be easily formed. Further, since the shrinkable tube can be omitted as compared with the conventional technique, the number of parts can be reduced and the cost can be reduced accordingly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a rubber mold part of an embodiment,

FIG. 2 is a cross-sectional view of a terminal portion of a power cable showing the configuration of an embodiment,

FIG. 3 is a cross-sectional view showing a state where the rubber mold part of FIG. 1 is opened,

FIG. 4 is a cross-sectional view showing a configuration of a conventional power cable terminal processing unit.

[Explanation of symbols]

 1 Terminal 2 Stress Cone 3 Semi-Conductive Fusing Tape 4 Waterproof Tube 5 Cable Insulator 5 Shielding Copper Tape 7 Cable Sheath 8 Cable Conductor 20 Stress Cone 21 Insulation Part 22 Extension Part 24 Semi Conductive Layer

Claims (2)

[Claims] 1. A stress cone in which an insulating part made of an insulating rubber material and an extension part made of a conductive rubber are integrally formed, and a hole having an outer diameter of the cable insulator is formed in the insulating part. A rubber mold component, characterized in that a hole having an inner diameter smaller than the outer diameter of the cable sheath is formed in the extension portion, and the extension portion can be folded back so as to be turned up from the center. 2. The end of the power cable is stripped off to expose the cable conductor, the cable insulator and the metal shielding layer,
A semiconductive crosslinked polyethylene tape is wound over the metal shield layer side and the metal shield layer of the cable insulator to form a semiconductive layer, and a folded rubber mold stress cone is inserted on the cable insulator to form a folded portion. A method for forming an end portion of a power cable, characterized in that the cable insulator and the cable sheath are covered by being opened.