JPH08214441A - Intermediate connection of solid insulating power cable - Google Patents

Abstract

PURPOSE: To facilitate work management and make possible the reduction of construction time by placing rubber packing between the circumference of a cable insulator and bracket integrally formed at one end of the external case of a connection, and pressing the rubber packing in the direction of cable length through clamp by means of a spring to form an oiltight seal area. CONSTITUTION: An external case 15 is filled with insulating oil 16, and rubber packing 17 with a trapezoidal cross section is installed on the external semiconductive layer 3 of a cable. Receiving hardware 15a, integrally formed at one end of the external case 15, is brought into contact with the upper face and one slope of the rubber packing 17. A clamp 18 has its one end bonded to the receiving hardware 15a, and presses the rubber packing 17 in the axial direction by means of a spring 19. Planar pressure is thereby applied to the rubber packing 17 to form an oiltight seal area. This attains the significant reduction of construction time and facilitates the management of seal area forming work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-immersion type intermediate connection portion of a power cable having a solid insulator such as crosslinked polyethylene formed by extrusion.

[0002]

2. Description of the Related Art The construction period of an intermediate connecting portion of a solid insulated power cable such as a CV cable (crosslinked polyethylene insulated power cable) is shortened, and an economical and compact electrically stable intermediate connecting portion is provided. A new structure has been proposed in which the reinforced insulating layer is composed of an insulating block and an oil-impregnated insulating tape winding layer. FIG. 2 is a vertical cross-sectional view of the upper half of an example of such an intermediate connecting portion. As shown in the drawing,
A tape winding in which an insulator block 11 containing an internal shield 12 is arranged on a conductor connecting portion 4 in which the cable conductor 1 is compression connected by a compression sleeve, and thin insulating tape is wound on both sides and outside of the insulator block 11. An insulating layer 13 is provided, and an insulating oil 16 is filled in an outer case 15 provided outside them. In the drawing, 3 is an outer semiconductive layer of the cable, and 14 is a shielding layer on the tape winding insulating layer 13.

As described above, there is no example in which the reinforcing insulating layer of the intermediate connecting portion of the solid insulated power cable is of the oil-immersed type, and the present invention is one of the important constituent requirements of such an oil-immersed type intermediate connecting portion. And an oil-tight seal between the connector outer case and the cable insulator.

On the other hand, there is an example in which an oil-immersed type is used as a terminal connecting portion of a CV cable. FIG. 3 shows a vertical cross section of the upper half of the main part of the seal structure for such an oil-immersed type connection part. As shown in the drawing, a mold having a structure capable of oil-tightly sealing the outer case 21, 22a and the flange portions 28a, 28b on the cable insulator 2 for holding the insulating oil 26, 27 filled in the outer case 21, 22. In order to secure oil tightness between the metal fitting 23 and the mold metal fitting 23 and the cable insulator 2, a plastic tape winding layer such as polyethylene tape is provided on both sides of the metal mold fitting 23.
After forming 24 and 25, the metal 23 and the cable insulator 2 are integrally molded by heating this and heating them.

[0005]

However, the method of winding and heating and molding the polyethylene tape described above requires a lot of equipment such as a cross-linking tube, a temperature control device and a pressurizing device to form the mold layer, and the seal is required. There is a problem in terms of construction period and economy such as requiring 2-3 days to form one part, and heating and pressurizing control are strictly performed so as not to adversely affect the electrical performance of the cable. There is a need.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, shortens the construction period, is economical, and is an intermediate connection portion of a solid insulated power cable which is economical and easy to manage work when forming an oil-tight seal portion. The feature is that a rubber packing is interposed between the outer circumference of the cable insulator and the receiving metal fitting formed at the end of the external case of the connecting portion, and the rubber packing is used by a spring through the tightening metal fitting. The oil-tight seal portion is formed by pressing in the length direction of the.

[0007]

In the intermediate connection portion of the solid insulated power cable of the present invention described above, a rubber packing is interposed between the outer periphery of the cable insulator and the metal fitting formed at the end of the outer case, and the rubber packing is tightened. By tightening through the metal fitting, a surface pressure is applied to the rubber packing and an oil-tight seal portion is formed. Therefore, since it can be easily formed without requiring a lot of conventional equipment, the construction period can be shortened and the economy can be remarkably improved. At this time, it is preferable to smooth the surface of the cable insulator to which the rubber packing is attached.

Further, by adjusting the spring force for pressing the rubber packing to limit the surface pressure of the rubber packing to 8 kg / cm ² · g or less, it is possible to prevent adverse effects on the cable insulator and to achieve long-term reliability. An oil-tight seal portion having excellent properties is formed.

[0009]

1 is a vertical cross-sectional view of the upper half of the main part of an intermediate connecting portion of a solid insulated power cable of the present invention. As shown in FIG. 2, a tape winding insulating layer 13 formed by winding a thin insulating tape is provided on the cable insulator 2 such as cross-linked polyethylene, and an insulating oil 16 is provided inside an outer case 15 provided outside the tape winding insulating layer 13. Is filled. A rubber packing 17 having a trapezoidal cross section is mounted on the outer semiconductive layer 3 of the cable, and a receiving metal fitting 15a integrally formed at the end of the outer case 15 is attached to the rubber packing 17 described above.
Abut on the upper surface of the trapezoid and one slope. At this time, it is preferable to smooth the surface 31 of the outer semiconductive layer 3 with which the rubber packing 17 is in contact.

On the other hand, a clamp 18 is abutted on the other trapezoidal slope of the rubber packing 17. This fastening metal fitting 18 has one end fixed to the receiving metal fitting 15a and has a flange portion of the fastening metal fitting 18a.
A spring 19 attached to a mandrel 19a that penetrates 18a.
Thus, the rubber packing 17 is pressed in the axial direction, and the surface pressure is applied to the rubber packing 17 to form an oil-tight seal portion.

[0011]

As described above, according to the intermediate connecting portion of the solid insulated power cable of the present invention, it is possible to easily form the oil-tight seal portion without requiring a lot of equipment and construction period. The construction period can be greatly shortened, which is economical and facilitates work management at the time of forming the seal portion. Also, by limiting the packing surface pressure to 8 kg / cm ² · g or less, it is possible to prevent adverse effects on the cable insulator, and it has excellent long-term reliability and solid insulation that requires high reliability. It is extremely effective when used in oil-immersed intermediate connections of power cables.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an upper half of a main part of an intermediate connecting portion of a solid insulated power cable of the present invention.

FIG. 2 is a vertical cross-sectional view of the upper half of the oil-immersed intermediate connection portion of the solid insulated power cable.

FIG. 3 is a vertical cross-sectional view of an upper half of a main part of an oil-immersion type terminal connection portion of a CV cable.

[Explanation of symbols]

 1 cable conductor 2 cable insulator 3 cable outer semiconductive layer 13 tape winding insulation layer 15 outer case 15a receiving metal fitting 16 insulating oil 17 rubber packing 18 tightening metal fitting 19 spring

Claims (1)

[Claims] 1. A rubber packing is interposed between the outer circumference of the cable insulator and a metal fitting formed at the end of the outer case of the connecting portion, and the rubber packing is provided in the length direction of the cable by a spring through a metal fitting. An intermediate connection portion of a solid insulated power cable, characterized by being pressed to form an oil-tight seal portion.