JPH0576125A - Joint of rubber, plastic power cable and jointing method - Google Patents

Abstract

PURPOSE:To reduce dimensions of a reinforcing insulation molded item in a joint and jointing method of rubber, plastic power cable wherein the tubular reinforcing insulation molded item, mounted on a conductor joint and the end of cable insulation layer, is thermally pressurized upon assemblage of joint and fused integrally with the cable insulation layer. CONSTITUTION:Tapered parts 5, 5' of insulation layer and exposed conductor parts 6, 6; are formed on cables 1, 1' to be connected and conductor connectors 7, 7'' are secured to the exposed conductor parts. After a socket 11 is loaded to one connector 7, a reinforcing insulation molded item 14 is mounted on the socket 11, the conductor connector 7 and the end of the cable 1 and secured in place. The conductor connector 7' secured to the exposed conductor part 6' of the other cable 1' is then inserted into the connecting socket and thermally pressurized from the outside thus integrally fusing the reinforcing insulator molded item 14 and the cable insulation layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting portion and connecting method for rubber and plastic power cables.

[0002]

2. Description of the Related Art In connecting a rubber or plastic power cable such as a cross-linked polyethylene power cable, a reinforced insulation molded body preliminarily molded is mounted on a cable conductor connecting portion which is compression-connected and both ends of the cable insulating layer,
After that, install a mold to cover the reinforced insulation molded body,
It is already well known that the reinforcing insulating molded body and the cable insulating layer are fused and integrated by applying pressure and heat from the outside.

In such a cable connecting portion and a cable connecting method, a connecting method using a cylindrical integrally molded body having a built-in high-voltage shield electrode as a reinforcing insulating molded body is disclosed in Japanese Patent Application No. 63-197243 filed by the applicant. (Japanese Patent Application Laid-Open No. 2-51306) and Japanese Patent Application No. 2-340979. On the other hand, a connection method using a molded body divided into a plurality of blocks as a reinforcing insulating molded body is disclosed in, for example, JP-A-50-109490 and JP-A-57-194.
471 and JP-A-61-196685.

[0004]

SUMMARY OF THE INVENTION In a cable connection method using a reinforced insulation molded body integrally formed in a cylindrical shape, the reinforced insulation molded body is connected in advance to the connected cable before compression connection of the conductor of the connected cable. Insert it in one side,
Since it is necessary to pull it back onto the conductor connecting portion after connecting the conductor, the inner diameter of the reinforced insulating molded body and the inner diameter of the built-in high-voltage shield electrode must be larger than the outer diameter of the insulating layer of the cable. Therefore, it is difficult to avoid an increase in the size of the cable connecting portion, and also the gap between the bisected conductor cover and the cable insulating layer and the reinforced insulating molded body to be mounted on the conductor connecting portion, the cable insulating layer end and the conductor cover. It is necessary to use parts such as halved diametrical insulators that fill the gaps between them.

In the connection method using the reinforced insulation molded body divided into a plurality of blocks, since the reinforced insulation molded body can be mounted after connecting the conductors, the size of the connecting portion can be reduced, but the block of the reinforced insulation molded body is divided. It is necessary to inject a crosslinkable insulating composition into the gap between them and the gap between the block and the insulating layer of the cable or the conductor connection part, and it is necessary to bring in an injection device such as an extruder at the connection site. Not only that, but it is difficult to avoid the inclusion of air in the injection part and the formation of voids. Further, when the reinforcing insulating molded body is divided into a plurality of blocks, it becomes difficult to incorporate the high-voltage shield electrode in the molded body.

An object of the present invention is to solve the above problems of the conventional connecting portion and connecting method, and to reduce the size of the connecting portion while using an integrally molded reinforced insulating molded body with less risk of void formation. To do.

[0007]

The present invention, which achieves the above object, provides a cylindrical reinforcing insulating molded body made of a crosslinkable insulating composition provided on a conductor connecting portion and the end portions of a cable insulating layer on both sides thereof. In a connecting portion and connecting method of a rubber or plastic power cable which is cross-linked by external pressure and heating and is fused and integrated with a cable insulating layer, a taper forming portion (in the insulating layer) is formed at each end of the connected cable. A so-called pencil sharpening part) and a conductor exposed part are formed, and conductor connectors fixed to the conductor exposed part are respectively inserted and connected to a connection socket, and a high voltage shield electrode is provided at the center of the inner peripheral surface of the reinforced insulation molded body. In addition, the inner peripheral surfaces on both sides of the shield electrode are shaped to fit the taper forming portion and the outer periphery of the insulating layer, and the shield electrode is fixed to one of the conductor connectors or the connection socket. It is characterized in that.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The connection portion and connection method for rubber and plastic cables according to the present invention will be described below in detail with reference to the embodiments and the drawings. FIG. 1 is a vertical sectional view of an embodiment of a connecting portion of a rubber or plastic power cable according to the present invention, and FIGS. 2 to 5 are partially longitudinal side views and longitudinal sectional views showing an assembling procedure of the connecting portion of the embodiment. Is. In each figure, the same reference numerals indicate the same parts.

In the figure, the cables 1 and 1 to be connected are provided with conductors 2 and 2, insulating layers 3 and 3 and an external semiconductive layer (not shown). At the ends of the cable to be connected, taper forming portions 5 and 5 formed by sharpening the insulating layers 3 and 3 with a conductor and so-called conductor exposed portions 6 and 6 formed with conductors are formed. Reference numerals 7 and 7 denote conductor connectors fixed to the conductor exposed portions 6 and 6, respectively. After the conductor connectors are put on the tips of the conductor exposed portions, the compression sleeve portions 8 and 8 are compressed to be crimped to the conductor exposed portions. ing. The conductor connectors 7, 7 are attached to the exposed conductors so that there is a gap between the rear ends of the conductor connectors 7, 7 and the tips of the taper forming portions 5, 5 of the cable insulating layer. To do. This is to allow the air in the gap between the reinforcing insulating molded body and the cable insulating layer, which will be described later, to escape into the conductor (stranded conductor) of the cable at the time of pressurizing and heating after assembling the connecting portion.

The heads 9 and 9 of the conductor connectors 7, 7 are inserted into the connection socket 11 and are connected to each other. That is, the conductors 2 and 2 of the connected cables 1 and 1 are connected by the connection socket 11 via the conductor connectors 7 and 7. In the figure, a finger socket is shown as an example of the connection socket 11. In the finger socket, a large number, for example, 16 movable members 12 are arranged in a cylindrical shape and are tightened by a ring-shaped spring 13. One conductor connector 7 is provided with a coupling screw portion 10 and is screwed with a screw of a high voltage shield electrode of a reinforced insulating molded body described below.

Reference numeral 14 is a cylindrical reinforced insulating molded body, and has a high-voltage shield electrode 15 at the center of the inner peripheral surface. In the reinforced insulation molded body 14, the insulating composition forming the molded body is crosslinked in the completed cable connection portion and is fused and integrated with the insulating layers 3 and 3 of the cable, but is not crosslinked when assembled. Is integrally formed in a cylindrical shape with an insulating composition of, for example, a polyethylene composition containing a cross-linking agent, and is fitted on both sides of the high-voltage shield electrode 15 to the taper forming portions 5 and 5 of the insulating layers 3 and 3 of the cable. A tapered inner peripheral surface 18 and a cylindrical inner peripheral surface 19 adapted to the outer periphery of the insulating layers 3 and 3 are formed.

On the outer periphery of the high-voltage shield electrode 15, a semiconductive layer 16 is provided as an electric field relaxation layer, for example, a heat-shrinkable semiconductive tube (which has been subjected to a crosslinking treatment) is heated and shrunk to cover it. A coupling screw 17 is provided on the convex portion of the inner peripheral surface of the electrode 15 and is screwed with the coupling screw portion 10 of the conductor connector 7. As a result, the high-voltage shield electrode 15 is fixed to the conductor connector 7 and electrically coupled thereto.

Reference numeral 20 denotes an external semiconductive layer, which is a reinforced insulating molded body 1.
The outer circumference of the cable 4 and the outer circumferences of the insulating layers 3 and 3 at the cable ends are covered and connected to the outer semiconductive layer of the connected cables 1 and 1. The semiconductive layer 20 may be formed by a heat-shrinkable semiconductive tube like the above-mentioned example of the semiconductive layer 16 on the outer periphery of the high voltage shield electrode, or a non-crosslinked semiconductive rubber or plastic tape containing a crosslinking agent may be used. It may be formed by winding.

Next, the method of connecting the rubber and plastic power cables of the present invention will be described by explaining the assembling procedure of the embodiment of the connecting portion of the present invention having the above-mentioned structure based on FIGS. 2 to 5 and FIG. Will be described in detail. 2, 3 and 4 each show a partial vertical side view,
FIG. 5 shows a vertical sectional view.

First, as shown in FIG. 2, a taper forming portion 5 and a conductor exposed portion 6 are formed on the end portion of the cable 1 to be connected. That is, the end of the insulating layer 3 is sharpened with a pencil and the conductor is exposed. The same applies to the connected cable 1.

Next, as shown in FIG. 3, the conductor connector 7 is attached to the conductor exposed portion 6, and the crimp sleeve portion 8 of the conductor connector 7 is compressed to place the conductor connector 7 on the conductor exposed portion 6. Stick firmly. The same applies to the connected cable 1 side. However, although the conductor connector 7 is provided with the coupling screw portion 10, the conductor connector attached to the connected cable 1 side is not provided with the coupling screw portion.

After that, as shown in FIG. 4, the connection socket 11 is mounted on the head 9 of the conductor connector 7. As described above, in the drawing, a finger socket is shown as the connection socket 11, and a large number of movable pieces 12 arranged in a cylindrical shape cover and engage the head 9 and the ring-shaped spring 13 causes the movable piece 12 to move. Is strongly tightened.

Next, as shown in FIG. 5, a reinforcing insulating molded body 14 integrally molded in a cylindrical shape is attached to the end portion of the cable 1 to be treated as described above, and the molded body 14 is rotated. Then, the coupling screw 17 of the high-voltage shield electrode is screwed into the coupling screw portion 10 of the conductor connector 7, and the reinforcing insulating molded body 14 is attached and fixed to the conductor connector 7.

Then, similarly to the connected cable 1, the end portion of the connected cable 1 to which the conductor connector 7 is fixed is inserted into the reinforced insulating molded body 14 assembled as described above (see FIG. 5).
(Inserted from the right side of FIG. 2), the head 9 of the conductor connector 7 is inserted into the connection socket 11. Upon this insertion, the head 9 of the conductor connector spreads the movable piece arranged in a cylindrical shape against the tightening force of the ring-shaped spring 13, but the head 9 is sufficiently inserted into the socket 11. Then, the expanded movable piece 12 returns to its original state by the force of the spring 13, and the movable piece 12 and the head 9 are engaged and coupled. Thus, the conductors 2 and 2 of the connected cables 1, 1 are the conductor connectors 7
Connected by connection socket 11 via and 7,
Further, a cylindrical reinforcing insulating molded body 14 is mounted on the conductor connecting portion and the end portion of the insulating layer of the cable.

Next, the outer periphery of the reinforced insulating molded body is coated, and the outer semiconductive layer 20 is coated so as to reach the end of the outer semiconductive layer of the cable.

After that, a mold (not shown) is attached to the connection portion assembled as described above, and the reinforced insulation molded body is heated,
Pressurize. By this heating and pressurization, the gap between the reinforcing insulation molded body and the cable insulating layer is crushed by the resin of the softened reinforcing insulation molded body, and the reinforcing insulation molded body and the cable insulating layer are fused together. The insulating composition forming the reinforced insulating molded body is crosslinked.

Various modifications can be made to the embodiment described above. For example, the connection socket 11 is not limited to the finger socket described above, and various known plug-in connection type sockets can be used. Further, instead of screwing the coupling screw of the high voltage shield electrode of the reinforced insulation molded body with the conductor connector, it can be screwed with the connection socket (however, in the case of the finger socket shown in the drawing). Further, the high-voltage shield electrode and the conductor connector or the connection socket can be coupled by screwing or the like instead of screwing. The fixing of the conductor connector to the exposed portion of the cable conductor is not limited to the above-described crimping by compression. Various methods such as welding, brazing or wedge type mechanical connection can be adopted.

[0023]

As described above, according to the present invention, after the connection socket is attached to the conductor connector fixed to one conductor exposed portion of the cable to be connected, the connection socket and the conductor connector inserted and connected thereto. And a reinforcing insulating molded body is mounted on the end of the insulating layer on the cable side to which the conductor connector is fixed, and fixed, and then the conductor connector fixed to the exposed conductor of the other connected cable is connected to the socket. Since it is inserted into and connected to the cable, it is not necessary to insert it in advance on the insulating layer of the cable to be connected before connecting the conductor, although the reinforcing insulating molded body integrally formed in a cylindrical shape is used.

Furthermore, since the end of the insulating layer of the cable to be connected is sharpened with a pencil to form a taper forming portion, the diameter of the tip of the insulating layer, that is, the tip of the taper forming portion is the conductor exposed portion of the cable or the conductor connection. The dimensions may be approximately the same as the outer diameter of the portion or slightly larger than these. Therefore, according to the present invention, the inner diameter of the high-voltage shield electrode that electrically shields the tips of the conductor connecting portion, the conductor exposed portion, and the taper forming portion is the outer diameter of the conductor connecting portion. The diameter can be reduced to almost the same as the outer diameter of the conductor connector. Therefore, the outer diameter of the reinforced insulating molded body can be significantly reduced as compared with the conventional integrally molded reinforced insulating molded body, and it is not necessary to use parts such as a conductor cover and a diametrical insulating body.

Further, in the connecting portion and the connecting method of the present invention using the integrally molded cylindrical reinforcing insulating molded body, there is no danger of void formation as in the case of using a plurality of divided reinforcing insulating molded bodies.

Further, in the connection portion and the connection method of the invention, as described above, the cylindrical reinforced insulating molded body is inserted into one of the connection layers of the cable to be connected, or after the conductor connection, this is connected to the conductor connection portion and the connection layer. It is not necessary to pull back onto the end portions of the insulating layer on both sides thereof, and the reinforced insulating molded body first comprises a connection socket, a conductor connector plugged in the socket, and a cable-side insulating layer end to which the conductor connector is fixed. The conductor connector fixed to the end of the insulating layer of the other cable to be connected and the exposed conductor part on the tip side of the other part is inserted into the reinforced insulation molded body from the other insertion port. Therefore, even if the bending due to the winding around the cable transport drum remains at the end of the cable to be connected to some extent, it does not cause difficulty in assembling the connection part, which is excellent in assembling workability. There are also advantages . When the connected cable is a large size cable, it is difficult to straighten the connected end of the cable, and a certain amount of curvature usually remains at the connected end.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a connecting portion of a rubber / plastic power cable of the present invention.

FIG. 2 is a partially longitudinal side view showing a first assembling procedure of the rubber and plastic power cable connection method of the present invention.

FIG. 3 is a partially longitudinal side view showing a second assembling procedure of the rubber and plastic power cable connection method of the present invention.

FIG. 4 is a partially longitudinal side view showing a third assembling procedure of the rubber and plastic power cable connection method of the present invention.

FIG. 5 is a vertical sectional side view showing a fourth assembling procedure of the rubber and plastic power cable connection method of the present invention.

[Explanation of symbols]

 1,1 Connected cable 5,5 Taper forming part 6,6 Conductor exposed part 7,7 Conductor connector 11 Connection socket 14 Reinforced insulating molded body 15 High voltage shield electrode

Claims (2)

[Claims] 1. A cylindrical reinforced insulating molded body made of a crosslinkable insulating composition provided on the conductor connecting part and on the ends of the cable insulating layer on both sides of the conductor connecting part is crosslinked by external pressure and heat, and the cable is formed. In the connection part of the rubber or plastic power cable fused and integrated with the insulating layer, the taper forming part and the conductor exposed part of the insulating layer are formed at the end part of the connected cable, and they are fixed to the conductor exposed part respectively. A conductor connector is inserted into a connection socket and connected, a high voltage shield electrode is provided in the center of the inner peripheral surface of the reinforced insulation molded body, and inner peripheral surfaces on both sides of the shield electrode conform to the taper forming portion and the outer periphery of the insulating layer. A connection portion of a rubber or plastic power cable, characterized in that the shield electrode is coupled and fixed to one of the conductor connectors or a connection socket. 2. A cylindrical reinforcing insulating molded body made of a crosslinkable insulating composition provided on the conductor connecting portion and the ends of the cable insulating layer on both sides of the conductor connecting portion is crosslinked by external pressure and heat, and the cable is formed. In a connecting portion of a rubber or plastic power cable that is fused and integrated with an insulating layer, a taper forming portion and an exposed conductor portion of the insulating layer are formed at end portions of the connected cable, and a conductor exposed portion of one connected cable is formed. After connecting the conductor connector fixed to the connection socket with the connection socket, a high-voltage shield electrode is provided at the center of the inner peripheral surface, and the inner peripheral surfaces on both sides of the electrode have a shape adapted to the taper forming portion and the outer periphery of the insulating layer. The reinforcing insulation molded body having the above is mounted on the socket, the conductor connector inserted and connected to the socket, and the insulating layer end of the cable to which the connector is fixed, and the shield electrode is a conductor. Rubber or plastic electric power, characterized in that it is fixed by connecting to a connector or a connection socket, and then the conductor connector fixed to the exposed conductor of the other connected cable is inserted into the other insertion port of the connection socket. How to connect the cable.