JPH0923561A - Joint for rubber plastic power cable - Google Patents

Abstract

PURPOSE: To provide a joint for a rubber/plastic power cable which is downsized by uniting a high-voltage shield electrode and a conductor contact and besides is firm and easy of manufacture. CONSTITUTION: In a joint for a rubber/plastic power cable, which sets electric continuity between the conductors of both cables by fixing the tips of the conductor connectors fixed to the tips of cables, in condition of butting them, inside the high shield electrode buried in a rubber/plastic reinforced insulator, the high-voltage shield electrode is composed of a shield body 21 for letting a current flow and two shield tips 22 for lightening electric fields, being coupled to both sides of the shield body 21. Current elements (louvers) 25 and 25a in contact with the inside periphery of the shield body 21 are provided capably of elastic transformation at the outside periphery of the conductor connector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection portion for rubber / plastic power cables such as cross-linked polyethylene insulation power cables, and more particularly to a block mold type connection portion (BMJ) for forming a reinforced insulator. In addition to making it smaller and lighter,
The high-voltage shield electrode embedded in the reinforced insulator block is composed of a contact portion for passing an electric current and a portion for relaxing an electric field, so that the high-voltage shield can be easily assembled and can have a simplified structure. TECHNICAL FIELD The present invention relates to a rubber / plastic power cable connection portion having electrodes and conductor connectors.

[0002]

2. Description of the Related Art When connecting a cross-linked polyethylene insulation power cable (hereinafter referred to as a CV cable), an extrusion model has conventionally been used in which an extruder, a mold or the like is carried into a connection site to form a reinforced insulator. -Led connection (EMJ) has been used. However, since this method requires a long time for work, requires skill, uses a lot of equipment, and the like, simplification of work and shortening of work time have been desired,
In order to answer this, a reinforcing insulator for the connecting portion is manufactured in advance, and after bringing this to the work site, it is assembled with the CV cable and is heated in order to be integrated with the cable insulator. A block mold type connection (BMJ) has been developed.

That is, this block mold type connecting portion (B
MJ) is configured, for example, as shown in FIG. 11, and the conductor connectors 5, 5a are integrally fixed to the respective tip portions of the conductors 2, 2a of the two CV cables 1, 1a, Further, the conductor connecting elements 5 and 5a are fitted in the cylindrical conductor contact element 7 so as to set a conductive state between the conductors. In this CV cable connection section 10,
A high-pressure shield having the cylindrical conductor contact 7 mounted in the center thereof.
A shield electrode 9 is arranged, and a reinforcing insulator 8 is integrally formed in a cone shape with a predetermined length around the high-voltage shield electrode 9. The reinforcing insulator 8 is integrally molded using a rubber / plastic material such as an uncrosslinked polyethylene resin containing a crosslinking agent.

In the block mold type connection portion 10,
A semiconductive layer 14 is arranged around the reinforced insulator 8, a waterproof mixture 15 is formed on the outside thereof with a predetermined thickness, and a metal protective tube 16 is arranged on the outer peripheral portion of the waterproof mixture 15. I am doing it. Further, when forming an insulating connection portion with respect to the protection tube 16, the insulating cylinder 17 is arranged at a predetermined position, and
The terminal seat 18 is arranged with respect to the protective tube 16 and connected to the ground. Further, the waterproof layer 19 is arranged in such a manner that both ends of the waterproof mixture 15 and the connection portion with the cable exterior are covered, and the waterproof layer 19 is protected by means such as winding an insulating tape. Moisture and the like are prevented from entering the inside of 16.

FIG. 10 is a view showing an assembling procedure of the block type connection portion (BMJ) of the insertion type CV cable shown in FIG. The connection portion 10 of the CV cable is subjected to a cable end treatment as follows to connect the cable conductor inside the reinforcing insulator 8 and to heat and compress the reinforcing insulator 8. It is formed by performing processing operations. (1) CV cables 1 and 1a of metal sheaths 11 and 11a
Is removed by a predetermined length (corresponding to the structure of the connecting portion) to correct the bending habit of the CV cables 1 and 1a.
The cable shields 4 and 4a are removed to expose the cable insulators 3 and 3a covering the conductors 2 and 2a (FIG. 10).
(A)). (2) Next, after removing the cable insulators 3 and 3a so that the conductors 2 and 2a are exposed by a predetermined length, the end portions of the cable insulators 3 and 3a are further tapered. Cut to 12a (FIG. 10 (B)). (3) The conductor connectors 5, 5a are compressed and attached to the exposed tips of the conductors 2, 2a, respectively. A conductor fixing jig 6 is used to mechanically connect and fix the conductors to these conductor connectors 5 and 5a (FIG. 10C). (4) A conductor in which the conductor connectors 5 and 5a are attached to the cable insertion holes 13 and 13a of the reinforcing insulator 8 in which the high-voltage shield electrode 9 having the conductor contact 7 installed in the center is embedded. Insert 2 and 2a from both sides. As the reinforcing insulator 8, a rubber or plastic material such as an uncrosslinked polyethylene resin to which a crosslinking agent is added is used, which is formed by combining a cylinder or a cylinder in two. And the conductor contact 7
The electrical connection is made by fitting one conductor fixing jig 6 provided at the end of the conductor connecting element 5a at the central portion of the above and the conductor fixing jig fitting hole 6a provided in the other conductor connecting element 5 to each other. (FIG. 10 (D), (E)).

As shown in FIG. 9, the conductor contact 7 is provided with several grooves 71 on the inner peripheral surface of a cylindrical main body 7a, and the grooves 71 are provided with the conductor connectors 5 and 5a. An end portion 72a of a cylindrical current element (louver) 72 having a large number of protrusions for fitting and making contact with the outer peripheral surface to energize is provided. The current element (louver) 72 is made of phosphor bronze plated with silver, and is formed so as to be elastically deformable when the conductor connectors 5 and 5a are fitted. A male screw 73 is threaded on the outer periphery of the main body 7a of the conductor contact 7, and is attached by being screwed into a female screw threaded on the inner circumferential surface of the high-voltage shield electrode 9.

[0007]

In the process of forming the conventional cross-linked polyethylene insulation power cable connection as described above, as shown in FIG. 8, the high voltage shield electrode 9 and the conductor contact 7 are formed. Is required, and this work is performed after the reinforcing insulator 8 is formed and before the heating and compression treatments, but it is extremely complicated work. Further, when the current element (louver) 72 is provided on the inner peripheral surface of the conductor contactor 7, the insertion work thereof is relatively difficult and requires a lot of labor. Further, the high-voltage shield electrode 9, the conductor contact 7 and the like have a considerable weight, and it is desired to reduce the size and weight of the power cable connection portion. The present invention has been made in view of the above-mentioned problems, and aims to reduce the size and weight by integrating a high-voltage shield electrode and a conductor contact, and to make the connection portion for a rubber / plastic power cable stronger and easier to manufacture. The purpose is to provide.

[0008]

That is, in order to solve the above-mentioned problems, the present invention fixes a conductor connector to the conductor ends of two cables to be connected, and connects these two conductor connectors. A rubber / plastic power cable that secures electrical continuity between the conductors of both cables by fixing it inside the high-voltage shield electrode embedded in a rubber / plastic reinforced insulator with the tips abutting. In the connection portion for a cable, the high-voltage shield electrode is composed of a shield main body for passing an electric current and two shield tips arranged on both sides of the shield main body for relaxing an electric field. In addition to the above structure, a current element (louver) that comes into contact with the inner peripheral surface of the shield body is provided on the outer peripheral surface of the conductor connector so as to be elastically deformable. Further, the high-voltage shield electrode is characterized in that the shield body is separately formed of a good conductive metal and the shield tip is formed of a lightweight metal, and these are connected. Further, the good conductive metal of the shield body is copper, and the lightweight metal of the shield tip is aluminum. Alternatively, the high-voltage shield electrode is characterized in that the shield body and the shield tip are integrally formed.

[0009]

When the rubber / plastic power cable connecting portion is any one of the above-mentioned means, since the high-voltage shield electrode and the conductor contact are integrated, the high-voltage shield electrode is connected to the conductor contact as in the prior art. There is no need to fit. When connecting and fixing the conductor connectors, the conductor fixing jig mounted on one conductor connector in the high-voltage shield electrode is simply inserted into the hole provided in the other conductor connector to fix the two conductors together. As a result, the assembling work becomes extremely easy and the size and weight can be reduced. Further, in the rubber / plastic power cable connection portion as the above-mentioned means, the current flowing through one conductor passes from this conductor through the conductor connector and through the current element (louver) to the shield electrode. Then, the current flows from the conductor connector to the other conductor via the current element (louver) again, or flows in the opposite direction, and heat generation during energization can be suppressed to a low level. The generated heat can also be promptly dissipated to the outside from the high-voltage shield electrode through the reinforcing insulator. In particular, the means (1) and (2) can reduce the weight of the high-voltage shield electrode. Further, in the means, if the whole is made of, for example, an integrated body of copper whose surface is silver-plated, the workability of the shield electrode is good and it is economical, and the shield main body portion and the shield tip portion are Workability is good without the trouble of connecting

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a high-voltage shield electrode 2 used in a rubber / plastic power cable connection portion of the present invention.
It is a longitudinal cross-sectional view which shows the structure of 0. The high-voltage shield electrode 20 includes a shield main body 21 that forms a central portion for passing an electric current, and two shields that are arranged on both sides of the shield main body 21 to reduce an electric field. Tips 22 and 22
It is made up of three parts, each of which is formed into a slightly thick tubular body. In this case, the two seams
The tip portions 22, 22 may have the same shape and size. And the shield main body portion 21 is a thick portion 21 at the center.
a and the thin-walled portions 21b and 21b at both ends, and the thin-walled portions 21b and 21b have female screws 21c.
And 21c are threaded. On the other hand, the shield tip 2
Reference numerals 2 and 22 are also formed in a thick portion 22a and a thin portion 22b, respectively, and in the thin portion 22b, male screws 22c and 22c are screwed with the female screws 21c and 21c of the shield body 21.
Is engraved. Curved surfaces 22d and 22d are formed at the outer ends of the shield tips 22 and 22 to reduce the concentration of the electric field. These shield tips 22 and 22 are easy to process and have a high pressure shield.
It is desirable to use an aluminum alloy for the purpose of reducing the weight of the entire solder electrode 20.

Thus, the shield body 21 and the two shields are provided.
The tip portions 22 and 22 of the high voltage shield electrode 20 are connected to each other by screwing as shown in FIG.
Becomes A male screw may be threaded on both sides of the shield body 21, and a female screw may be threaded on the two shield end portions 22 and 22 to connect them.

Conductor connectors 23 and 23a, which will be described later, are fitted and fixed to the shield body 21. In this case, since the conductor connectors 23 and 23a are fitted and contacted with the inner peripheral surface of the thick portion 21a of the shield main body portion 21 to flow an electric current, a connection portion (BMJ) for power cable during operation is provided. It is necessary to suppress the temperature rise. Therefore, the shield body 21
In order to reduce heat generation, it is desirable to devise a method of reducing the conductor resistance such as by plating the copper alloy with silver.

FIG. 3 is a sectional view showing a state in which the conductor connector 23 is press-fitted into one conductor 2 and the conductor connector 23a is press-fitted into the other conductor 2a. As described above, the shield body 2
These conductor connectors 23 and 23a are fitted to the connector 1. However, two grooves 24 and 24a are provided on the outer peripheral surface of each of these conductor connectors 23 and 23a (two grooves 24 and (Not limited to books), current elements (louvers) 25, 25 having a multi-faceted contact shape with many protrusions formed on the outer peripheral surface
a is attached. These current elements (louvers) 25,
Reference numeral 25a denotes a thin cylindrical body on which a large number of multi-faceted projections are formed, which is manufactured by silver plating a copper alloy (for example, phosphor bronze) or silver plating on stainless steel. Further, the current elements (louvers) 25 and 25a are formed so as to be elastically deformed when they are fitted into the shield main body portion 21, but the polyhedral projections themselves are elastically deformable. In some cases, the protrusion itself does not elastically deform, and the grooves 24, 2
There is a case where a spring material is arranged inside 4a to elastically deform it.

Next, a conductor fixing jig 27 is attached to the conductor connector 23a press-fitted into the other conductor 2a,
The conductor connector 23 press-fitted into the one conductor 2 is provided with a hole 26 (see FIG. 5) into which the conductor fixing jig 27 is fitted. The conductor fixing jig 27 has a body 27a fixed to the tip of the conductor 2a and a protrusion 27b provided on the body 27a. The protrusion 27b is configured to be projected and retracted by a spring (not shown) arranged inside the body 27a. There is. The conductor connectors 23 and 23a are provided with these conductor fixing jigs 27 and holes 26.
It is adapted to be joined by fitting and. That is, as shown in FIGS. 4 and 5, the conductor fixing jig 27 fixed to the other conductor connector 23a is fitted into the hole 26 of the one conductor connector 23 to connect the two conductors 2 and 2a. Is done.

FIG. 6 shows a shield body 21 and two shields.
A block electrode in a state in which conductor electrodes 23 and 23a, in which current elements (louvers) 25 and 25a are mounted, are fitted to the shield electrode 20 composed of the tip portions 22 and 22 of the shield and covered with the reinforcing insulator 8. It is a longitudinal cross-sectional view of a wedge-shaped connection portion (BMJ). In the case of forming this block mold type connection portion (BMJ), a rubber / plastic material of an uncrosslinked polyethylene resin added with a crosslinking agent is formed in a central portion of a reinforcing insulator 8 which is formed by combining a tubular shape or a cylinder into two. The high voltage shield electrode 20 including the shield body 21 and the shield tips 22 and 22 is embedded in the cable insertion hole 1
The conductors 2 and 2a to which the conductor connectors 23 and 23a are attached are inserted from both sides from 3 and 13a, and the current layers (louvers) 25 and 2 of the conductor connectors 23 and 23a are inserted in the shield body 21.
5a is brought into contact with each other to be connected and electrically connected to crosslink the uncrosslinked polyethylene resin.

In the rubber / plastic power cable connection portion of the present invention constructed as described above, since the high-voltage shield electrode and the conductor contactor are integrated, the high-voltage shield electrode is formed as in the conventional case. There is no need to fit a conductor contact. When connecting the conductor connectors 23, 23a, etc., one conductor connector 2 in the high voltage shield electrode 20 as described above.
The conductor fixing jig 27 attached to 3a is used for the other conductor connector 2
Since the conductors 2 and 2a can be connected to each other only by fitting them into the holes 26 provided in the hole 3, the assembling work becomes extremely easy and the size and weight can be reduced.

In the rubber / plastic power cable connecting portion having the above-described structure, as shown in FIG. 7, a current 28 flowing through the conductor 2 is transferred from the conductor 2 to the conductor connector 2.
3 through the current element (louver) 25 into the main body portion 21 of the shield electrode 20, and again the current element (louver) 2
Flow from the conductor connector 23a to the conductor 2a via 5a,
Or it flows in the opposite direction. In this case, since the shield electrode main body 21, the current element (louver) 25, etc. are silver-plated on the copper alloy, not only the heat generation at the time of energization can be suppressed low, but also the generated heat can be quickly generated by the high pressure shield. It can be diffused from the field electrode 20 to the outside through the reinforcing insulator 8.

A specific embodiment of the present invention is as described above, and the high-voltage shield electrode 20 is disposed on the shield body 21 and both sides of the shield body 21 for the purpose of weight reduction. The embodiment in which the shield body 22 and the shield body 22 are made of a copper alloy and the shield body 22 is made of aluminum is described. Not limited to the embodiment, the shield body 2
1 and the shield tip portions 22 arranged on both sides may be made of the same copper alloy and may be integrally manufactured. In this way, if the shield body 21 of the high-voltage shield electrode 20 and the shield tips 22 on both sides are formed as an integral body of copper, for example, the surface of which is plated with silver, the workability of the shield electrode itself is improved. It is good and economical, and the workability is improved because it does not take time to connect the shield body and the shield tip.

The high voltage shield electrode 20 and the current element (louver) composed of the shield main body 21 and the two shield tips 22 and 22 described in the above embodiment. ) Conductor connectors 23 and 2 equipped with 25 and 25a
The use of 3a is not limited to the insertion type block mold type connection portion (BMJ) described in the embodiment, but can be also used for the non-insertion type block mold type connection portion (BMJ).

[0020]

As described in detail above, according to the rubber / plastic power cable connecting portion of the present invention, not only can the connection structure of the block mold type connecting portion (BMJ) be simplified, It is possible to reduce the number of parts by integrating the high-voltage shield electrode and the conductor contactor without changing the shape that influences the electrical characteristics of the conventional high-voltage shield electrode, and to reduce the size and weight. Also, in the past, the work process of fitting the conductor contact to the high-voltage shield electrode was required, and after the block reinforcing insulator was completed, the assembling work was performed, but the current element (louver) was connected to the conductor. It can be easily inserted and assembled by mounting it on the outer surface of the child. Since the conductor fixing jig can be formed to have a large size so as to withstand the force of expansion and contraction of the conductor due to the heat generated by the energization during the operation of the cable, the strength can be increased. Further, the heat generated by the energization during the operation of the cable has been conventionally conducted from the conductor contact to the block reinforcing insulator through the high voltage shield electrode. In the section, since the high-voltage shield electrode has a role of a conductor contact, heat can be quickly transmitted to the high-voltage shield electrode and easily dissipated to the outside through the reinforcing insulator.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the structure of a high-voltage shield electrode used in a rubber / plastic power cable connection portion of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state in which high-voltage shield electrodes used in the rubber / plastic power cable connection portion of the present invention are connected.

FIG. 3 is a view showing a conductor and a conductor connecting portion which constitute the rubber / plastic power cable connecting portion of the present invention, in which the conductor connecting member is press-fitted and fixed to one conductor, and the conductor is connected to the other conductor. It is sectional drawing of the state which press-fitted and fixed the connector.

FIG. 4 is a view showing a conductor and a conductor connecting portion which constitute the rubber / plastic power cable connecting portion of the present invention, and is a conductor fixing jig attached to an end portion of the conductor connecting member press-fitted and fixed to the conductor. FIG. 6 is a cross-sectional view showing a state before the tool is fitted and connected to the conductor connector in which the other conductor is press-fitted and fixed.

FIG. 5 is a diagram showing a conductor and a conductor connecting portion which constitute the rubber / plastic power cable connecting portion of the present invention, and is a conductor fixing jig attached to an end portion of the conductor connecting portion press-fitted and fixed to the conductor. It is sectional drawing which shows the state which was fitted in the conductor connector which press-fitted and fixed the other tool, and was connected.

FIG. 6 is a diagram showing a part of the structure of the rubber / plastic power cable connecting portion of the present invention, in which a shield electrode composed of a shield body portion and two shield tip portions is provided. FIG. 3 is a vertical cross-sectional view of a block mold type connection portion (BMJ) in a state in which a conductor connector equipped with a current element (louver) is fitted and covered with a reinforcing insulator.

FIG. 7 is a diagram showing a part of the configuration of the rubber / plastic power cable connecting portion of the present invention, in which two conductors and a current element mounted on a conductor connector fixed to these two conductors are mounted. It is a longitudinal cross-sectional view showing the flow of current.

FIG. 8 is a vertical cross-sectional view of a conventionally used conductor contactor.

FIG. 9 is a vertical cross-sectional view of a high-voltage shield electrode fitted with a conductor contact arranged in a conventional reinforced insulator.

10A to 10E are insertion-type CVs.
It is a figure which shows the assembly procedure of the block mold type | mold connection part (BMJ) of a cable.

FIG. 11 is a vertical cross-sectional view showing the configuration of a power cable connecting portion using a conventional reinforced insulator.

[Explanation of symbols]

 1, 1a CV cable 2, 2a conductor 20 high voltage shield electrode 21 shield body 22 shield tip 23, 23a conductor connector 25, 25a current element (louver)

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeto Nakamura 1008 Shinbori, Kumagaya-shi, Saitama Mitsubishi Cable Industries, Ltd. Kumagaya Manufacturing Co., Ltd. (72) Iwa Otaka 1008 Shinbori, Kumagaya-shi, Saitama Mitsubishi Cable Industries, Ltd. Kumagaya Factory

Claims (4)

[Claims] 1. A high voltage embedded in a rubber / plastic reinforced insulator with a conductor connector fixed to the conductor ends of two cables to be connected and the tips of these two conductor connectors abutting each other. In the rubber / plastic power cable connection, which is fixed inside the shield electrode and establishes electrical continuity between the conductors of both cables, the high-voltage shield electrode is used for passing current. Of the shield body and two shield tips disposed on both sides of the shield body for relaxing an electric field, and the shield body is provided on the outer peripheral surface of the conductor connector. A rubber / plastic power cable connecting portion, characterized in that a current element (louver) that comes into contact with the inner peripheral surface of the portion is provided so as to be elastically deformable. 2. The high-voltage shield electrode is characterized in that the shield body is formed of a good conductive metal and the shield tip is formed of a lightweight metal, respectively, and these are connected. The rubber / plastic power cable according to claim 1.
Bull connection. 3. The rubber / plastic power cable according to claim 1, wherein the good conductive metal of the shield body is copper, and the lightweight metal of the shield tip is aluminum. Bull connection. 4. The rubber / plastic power according to claim 1, wherein the high-voltage shield electrode is constructed by integrally forming a shield body and a shield tip. Cable connection.