JPH0680341U - Cable connection - Google Patents

Abstract

(57) [Abstract] [Purpose] The process of eliminating the step at the cut end of the external semiconductive layer can be performed easily and in a short time without variations in the finish. Provided is a cable connection useful for connecting a cable having a tripping type outer semiconductive layer. [Structure] A semi-conductive rubber / plastic is provided over the end of the cable outer semi-conductive layer 12 exposed by stripping off the cable end 8 and over the cable insulator 11, and the cable outer semi-conductive layer is provided at the center. A spacer 13 having an end portion insertion hole 13a and a cable insulator insertion hole 13b subsequent thereto and having arcuate outer peripheral surfaces 13c whose both ends abut on the cable outer semiconductive layer 12 and the outer peripheral surface of the cable insulator 11 is attached. A pre-molded stress cone 14 is mounted on the cable outer semi-conductive layer 12 on both sides of the cable insulator 11 and over the cable insulator 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cable connecting portion, and more particularly to a cable connecting portion useful for connecting a rubber / plastic insulated cable having an outer semiconductive layer of a free stripping type.

[0002]

[Prior art]

 In recent years, a rubber / plastic insulated cable with an outer semiconductive layer, which is formed by using a material with good release properties and has a so-called free striping type, has been developed, and it is easy to remove the step when connecting the cable. It is attracting attention because it provides a smooth exposed surface of the cable insulator.

By the way, the connecting portion of this type of cable is, as in the case of a cable having a conventional bond type outer semiconductive layer, as shown in FIG. A non-crosslinked semiconductive rubber / plastic tape is wound from the outer semiconductive layer 2 to the cable insulator 3 and heated to form a tape winding mold layer 4 on which a rubber for electrolytic relaxation is formed. It is configured with a stress cone 5 attached. The tape winding mold layer 4 is formed in order to eliminate a step at the cut end of the outer semiconductive layer 2 and prevent a gap from being formed under the rubber stress cone 5. In FIG. 3, 6 is a conductor and 7 is a semiconductive layer inside the cable.

[0004]

[Problems to be solved by the device]

 However, at such a cable connection portion, it takes time (usually about 1 day) to form the tape winding mold layer 4 which is provided to eliminate the step difference at the cut end of the outer semiconductive layer 2. There was a problem that the efficiency improvement of the connection work by the free stripping did not go up so much. In addition, the tape winding work requires skill and there is a problem in that variations in the finished product occur.

Therefore, it has been considered to omit the formation of the tape winding mold layer 4 by chamfering the cut end of the outer semiconductive layer 2 with a knife or a filer and performing a taper process, but it is a free stripping type. Since the outer semiconductive layer 2 of is not soft like the outer semiconductive layer of the bond type, it takes a lot of time and skill to work, and also damages the cable insulator 3. There was a fear. Moreover, even if such a taper process could be performed, the cut end might be turned up because the outer semiconductive layer 2 itself was soft.

The present invention has been made in response to such a conventional situation, and it is possible to easily and quickly perform the process of eliminating the step at the cut end of the outer semiconductive layer without causing variations in the finish. Therefore, it is an object of the present invention to provide a cable connection portion that can significantly improve the efficiency of the entire connection work and stabilize the characteristics.

[0007]

[Means for Solving the Problems]

 The cable connection part of the present invention is made of semi-conductive rubber or plastic and extends from the end of the cable outer semi-conductive layer exposed by stripping off the end of the cable to the end of the cable insulator. A spacer having a conductive layer end insertion hole and a cable insulator insertion hole following it, and having arcuate outer peripheral surfaces at both ends contacting with the cable outer semiconductive layer and the outer peripheral surface of the cable insulator, respectively, is mounted on the spacer. The pre-molded stress cones are mounted on the cable insulators on both sides of the cable outside the semiconductive layer.

[0008]

[Action]

 In the cable connection portion of the present invention, the step processing of the cut end of the cable outer semiconductive layer, which was conventionally performed by the tape winding molding process, is performed by mounting the spacer formed in a predetermined shape in advance. Connection workability has been improved and work time can be significantly reduced. Also, mounting the spacer does not require skill unlike tape winding, and does not cause variations in finish, so that good and stable connection portion characteristics can be obtained.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an enlarged sectional view showing a main part of a connecting portion of a 66 kV class CV cable according to an embodiment of the present invention.

In FIG. 1, reference numeral 8 designates an inner semiconductive layer 10 and an insulator 11 made of crosslinked polyethylene on a conductor 9 in that order, on which EVA (ethylene-acetic acid) having a high degree of polymerization of vinyl acetate is provided. External semiconducting layer consisting of extruding a semiconducting composition whose base polymer is a vinyl copolymer, that is, a free-stripping type external semiconducting layer that can be easily peeled off without being fused with the crosslinked polyethylene insulator 11. Although not shown in the drawing, a layer 12 is provided, and a stripped end of a CV cable having a structure in which a shielding layer formed by winding a copper tape and a sheath formed by extruding vinyl chloride resin are sequentially provided, though not shown. Parts are shown. The free-stripping type outer semiconductive layer 12 is cut along a plane perpendicular to the cable axis, and its end is not chamfered by a knife or the like.

Therefore, in this embodiment, the free-stripping type outer semiconductive layer 12 extends over the end portion of the cable insulator 11 and is molded in advance with a semiconductive rubber / plastic material. An arc-shaped outer peripheral surface 13c having a cable outer semiconductive layer end insertion hole 13a and a cable insulator insertion hole 13b following it, both ends of which are respectively in contact with the cable outer semiconductive layer 12 and the outer peripheral surface of the cable insulator 11. A spacer 13 having a pre-molded stress cone 14 is mounted on the cable outer semiconductive layer 12 on both sides of the spacer 13, and a spacer 13 is located under the semiconductive conductive layer 14a. It is mounted and configured to Here, as the semiconductive rubber / plastic forming the spacer 13, it is preferable to use an elastic material such as semiconductive EP rubber (ethylene / propylene rubber) from the viewpoint of adhesion. It is preferable that the cable outer semiconductive layer end insertion hole 13a and the cable insulator insertion hole 13b have a diameter slightly smaller than the end portion of the cable outer semiconductive layer 12 and the outer diameter of the cable insulator 11. Further, in the pre-mold stress cone 14 as well, in order to increase the surface pressure and improve the dielectric strength at the interface, it is desirable to make the inner diameter of the central cable insertion hole 14b as small as possible.

In order to form such a cable connection portion, first, from the cable end side, the end portion 8 of the CV cable is stripped off and exposed toward the cut end of the free-stripping type outer semiconductive layer 12 exposed. The spacer 13 is inserted, and the cable outer semiconductive layer end insertion hole 13a is fitted to the end of the cable outer semiconductive layer 12, and the cable insulator insertion hole 13b is fitted to the cable insulator 9, respectively. Then, the pre-mold stress cone 14, which has been previously fitted and inserted near the cable sheath on the cable outer semi-conductive layer 12, may be pulled and mounted at a predetermined position. This forms a cable connection with good and stable properties.

As described above, in the cable connecting portion having the above-described structure, the step of the cut end of the cable outer semiconductive layer 12 can be processed only by mounting the spacer 13, so that the working time can be significantly shortened and the connecting portion can be reduced. The characteristics are also improved and stabilized.

Although the above embodiment is an example in which the step of the cut end of the cable outer semiconductive layer 12 is carried out only by mounting the spacer 13, in the present invention, the outer cable semiconductive layer 12 of the spacer 13 and In order to improve the adhesion of the interface with the cable insulator 11 and the surface smoothness under the pre-mold stress cone 14, thereby obtaining a cable connection part with improved insulation characteristics, as shown in FIG. It may be configured to.

That is, in the embodiment shown in FIG. 2, in the case of the embodiment shown in FIG. 1, the first semi-conductive member of a predetermined length is provided at an appropriate distance from the cut end of the cable outer semi-conductive layer 12. Heat-shrinkable tube 15 is mounted, and the spacer 13 is mounted on the first semi-conductive heat-shrinkable tube 15 from the end of the free-stripping outer semi-conductive layer 12 to the cable insulator 11. Further, the structure is such that the second semiconductive heat shrinkable tube 16 is mounted over the cable outer semiconductive layer 12, and although not shown, the premolded stress cone 14 is mounted on these. . The semiconductive heat-shrinkable tube generally has a tendency that the shrinkage rate decreases as the conductivity increases, and conversely the shrinkage rate increases when the conductivity decreases. Therefore, the first semiconductive heat-shrinkable tube 15 has a slightly low shrinkage but a high conductivity and a thin wall, and second semi-conductive heat shrinkable tube 16 has a slightly low conductivity but a high shrinkage and a relatively thick wall. It is desirable to use one.

In this embodiment, as compared with the embodiment shown in FIG. 1, the work of mounting the first and second semi-conductive heat-shrinkable tubes 15, 16 is increased, but these operations are performed in a tape winding mode. It is much simpler than the above, and there is no risk of variations in characteristics. By mounting such first and second semiconductive heat shrinkable tubes 15 and 16, the interfacial adhesion of the spacer 13 is enhanced and the surface smoothness under the premold stress cone 14 is also improved. , More excellent insulation characteristics can be obtained.

As described above, also in the embodiment shown in FIG. 2, it can be formed easily and in a short time, and has good and stable connection portion characteristics.

In addition, in the present invention, in the case of each of the above-described embodiments, it is possible to further prevent the formation of minute voids at the interface of the spacer 13, the semiconductive heat-shrinkable tubes 15 and 16, or the premold stress cone 14. In order to achieve this, various semiconductive paints, semiconductive silicone oils, semiconductive silicone gels, etc. may be applied to the surface of the part where these are mounted. As a result, the adhesiveness is further increased, and the insulating property can be further improved.

Further, each of the above embodiments is an example in which the present invention is applied to the connection portion of a 66 kV class CV cable having a free-stripping type external semiconductive layer, but the present invention is not limited to such embodiments. However, the present invention can be applied to various low-voltage to ultra-high-voltage cables including a conventional cable having a bond-type outer semiconductive layer, and the same effects as those of the above-described embodiment can be obtained.

[0021]

[Effect of device]

 As described above, according to the cable connecting portion of the present invention, since the step treatment of the cut end of the cable outer semiconductive layer is performed by using the spacer, the connecting work time can be significantly shortened. In addition, the work does not require skill and there is no variation in finishing, so that the characteristics of the connecting portion can be improved and stabilized.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a main part of a cable connecting portion according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an enlarged main part of another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional cable connecting portion.

[Explanation of symbols]

 8 ………… Stepped CV cable end 11 ………… Cable insulator 12 ………… Free-stripping type outer semiconductive layer 13 ………… Spacer 13a ………… Cable outer semiconductive layer end insertion hole 13b ……… Cable insulator insertion hole 13c ……… Circular arc-shaped outer surface 14 ……… Pre-molded stress cone

Claims (1)

[Scope of utility model registration request] 1. A semi-conductive rubber / plastic material extending over the end of the cable outer semi-conductive layer exposed by stripping off the cable end from the end of the cable outer semi-conductive layer to the center of the cable outer semi-conductive layer end. A spacer having a part insertion hole and a cable insulator insertion hole following it, and having arcuate outer peripheral surfaces at both ends contacting the cable outer semiconductive layer and the outer peripheral surface of the cable insulator, respectively, are mounted on both sides of the spacer. A cable connection part, characterized in that a premolded stress cone is mounted over the cable outer semiconductive layer over the cable insulator.