JPH0125481Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to improvements in insulated connections of power cables.

(Technical background of the invention) The diameter of insulated connections in power cables such as OF cables and CV cables has been reduced by making cable conductor joints of the same diameter and reducing the insulation thickness of insulation reinforcements.

FIG. 1 shows a portion of a conventional insulated connection of a power cable. That is, this connection part connects the insulating tube 1 coaxially disposed on the reinforcing body (not shown) on the connected conductor of the power cable so as to cover the insulating reinforcing body (not shown), and the insulating tube 1. A pair of protection tubes 2 with flanges 2a arranged on both sides,
2. The insulating tube 1 and the protective tubes 2, 2 are arranged such that the flanges 2a of each protective tube 2 are engaged with the circumferential end surfaces on both sides of the insulating tube 1, and the tightening bolts 3 are inserted into the metal fittings 1a embedded in the end surfaces. Flange 2a
They are fixed to each other by screwing in from the sides.

Further, an annular recess is provided on the surface of the flange 2a that contacts the end surface of the insulating tube 1, and an O-ring 4 is attached thereto, thereby maintaining the watertightness of the insulating connection portion.

(Problems in the Background Art) However, if the protective tube 2 having such a flange 2a is used, that is, if the flange 2a is used to fix the insulating tube 1 and the protective tube 2, the outer diameter for insulating connection will be smaller than that of the flange 2a. Moreover, since the flange 2a needs to have a diameter that allows at least the bolt 3 to be tightened and the O-ring 4 to be attached, there is a limit to how small the diameter can be.

(Purpose of the invention) An object of the invention is to provide an insulated connection portion for power cables having a small outer diameter.

(Summary of the invention) The invention constructs an insulating cylinder from a molded cylinder integrally molded with the protection tube and having approximately the same diameter between the opposing ends of a pair of protection tubes without flanges. The insulated connection part is characterized by a small diameter while maintaining watertightness.

(Embodiments of the invention) Hereinafter, embodiments of the invention will be described with reference to the drawings.

FIG. 2 shows an insulated connection part of an OF cable according to the present invention. In this insulated connection part, cable conductors 6, 6 exposed from each terminal of both OF cables 5, 5 to be connected are jointed with the same diameter,
On these conductors 6, 6 are cable cores 5a, 5a.
An insulating reinforcing body 7 consisting of a winding of insulating oil-impregnated paper is provided astride.

This insulation reinforcement body 7 is provided with a reduced insulation thickness. A pair of protection tubes 8, 8 are aligned and coaxially disposed on the insulation reinforcement body 7 along the length direction of the OF cable 5, and an insulation tube is provided between the opposing ends of each protection tube 8. 9 are arranged. This insulating tube 9 is made of an epoxy resin molded tube that includes opposing ends of the protective tubes 8 and is molded to have approximately the same diameter as these protective tubes 8.

A spacer 10 is inserted into the other end of each protection tube 8 extending to the metal sheath 5b.
and spacer 10 and spacer 10 and metal sheath 5
b are connected to each other by lead fittings 11 while maintaining watertightness. Therefore, the insulating oil injected into the protective tube 8 will not leak out.

In this way, the insulating tube 9 is formed from a molded tube made of epoxy resin integrally molded with approximately the same diameter as the protective tube 8.
By forming this, the protective tube 8 and the insulating tube 9 can be fixed to each other without providing a flange on the protective tube 8, so that the outer diameter of the insulating connection part is approximately 50 mm.
It is small, and watertightness can be maintained without using an O-ring.

In addition, the protective tube 8, the spacer 10, and the spacer 10
The connection between the metal sheath 5b and the metal sheath 5b may be performed by welding or taping.

Although the above embodiment shows an example in which the present invention is applied to an insulated connection part of an OF cable, the present invention can be similarly applied to an insulated connection part of a POF cable, a GF cable, a cable with pressure such as a refrigerant. Can be applied.

FIG. 3 shows a modification of the present invention, in which the insulating tube 9 is formed from a molded tube having the same inner diameter as the protective tube 8. In this way, the insulation tube 9
Since this does not protrude toward the insulating reinforcing body 7 side, the connection work becomes easy and the molding work of the mold tube can be simplified.

(Effects of the invention) According to the invention, the insulating cylinder is constructed from a molded cylinder integrally formed with approximately the same diameter as the protection tube between the opposing ends of the protection tube, thereby eliminating the need for flanges. In addition to being able to fix the insulating tube and the protective tube, there is no need for a watertight member such as an O-ring.

Therefore, an economical insulated connection for power cables with a small outer diameter is obtained. When the outer diameter of the insulated connection portion is reduced in this way, the manhole for the joint can be omitted, and therefore the cost required for cable installation can be reduced.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a part of a conventional insulated connection part.
FIG. 2 is a longitudinal cross-sectional view of an insulated connection part according to the present invention, and FIG. 3 is a partial vertical cross-sectional view of a modification of the present invention. 1, 9...Insulating cylinder, 2, 8...Protection tube, 2a...
...Flange, 4...O ring, 5...OF cable, 5b...Metal sheath, 7...Insulation reinforcement, 1
0... Spacer, 11... Lead work.

Claims (1)

[Scope of utility model registration request] an insulating tube coaxially disposed on the insulating reinforcement on the interconnected conductors of each power cable;
A power cable insulated connection part comprising both ends of the insulating tube and a pair of protective tubes fixed to each other while maintaining watertightness, the insulating tube including opposing ends of the pair of protective tubes. An insulated connection part for a power cable, characterized in that it consists of a molded tube integrally molded with substantially the same diameter as the protection tube.