JPS6029299Y2 - Edge cutting connection of rubber/plastic cable - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention is an edge cutting connection for rubber/plastic cables that is useful when the finished outer diameter of the rubber/plastic cable connection part can be made small and can be formed at low cost. This is related to the department.

(Technical background of the invention and its problems) In general, in a single-core cable cable installed line, cross-bond grounding is performed at the connection part of the cable line in order to increase the power transmission capacity.

As shown in FIG. 1, the cable connection part of this cross bond grounding part is composed of a cable insulation connection part 1 and a protection tube 3 having an insulating tube 2 provided on the circumference thereof, and the cable line is They are electrically separated by the insulating cylinder 2 mentioned above.

By the way, the insulating tube 2 is made of epoxy resin or the like,
Designed to withstand the required internal pressure.

That is, at the connection portion of the OF cable line, since the protective tube is filled with insulating oil while maintaining the required pressure, the insulating tube must also be designed to withstand this internal pressure.

However, when applying an insulating cylinder with such a structure to the joint of a rubber/plastic cable, there is a problem that the design is over-designed because there is no insulating oil like in an OF cable, and as a result, the finished outer diameter of the cable joint is However, the diameter was larger than necessary, which was disadvantageous economically.

(Purpose of the invention) The present invention was made based on the above circumstances, and aims to provide a edge-cut connection part for rubber/plastic cables that can reduce the finished outer diameter of the cable connection part and be formed at low cost. It is something.

(Summary of the invention) In the invention, an insulating tube is formed by a pair of funnel-shaped metal tubes, each having a small diameter portion that fits into the opening, and a large diameter portion that is shorter than the small diameter portion that fits around the outer periphery of the opening of the metal tube. and by fitting one opening of the pair of funnel-shaped metal tubes onto the small diameter part of the insulating cylinder and fitting the other opening into the large diameter part to connect them to each other, thereby achieving the above purpose. are related.

(Embodiment of the invention) Hereinafter, the present invention will be described in detail based on the drawings of one embodiment.

In FIG. 2, a pair of cable conductors 4at4b to be connected exposed by the step stripping process are compressed and connected by a sleeve 5, and a pair of cable insulation layers 7a, ? A reinforcing insulating layer 8 is provided spanning between the gaps B, and an edge-cutting shielding layer 9 is provided thereon.

The edge-cutting shielding layer 9 has a first shielding layer 11a connected to one cable shielding layer 10a, one end connected to the other cable shielding layer 10b, and the other end connected to the first shielding layer 11a via a reinforcing insulating layer 12. The second one is provided so that it overlaps the tip.
and a shielding layer 11b.

An insulating tube 14 shown in FIG. 3 is fitted onto the insulated connection portion 13 of the cable formed as described above.

This insulating tube is composed of a small diameter tube 15 and a large diameter tube 16 formed in series with the end of the small diameter tube 15. On the outer periphery of the small diameter tube 15, a first protective tube 1 is fitted into one cable sheath 17a.
8a is installed, and the small diameter cylinder 1 is attached with bolts 19a.
It is fixed to 1a.

On the other hand, the end of the second protection tube 18b fitted into the other cable sheath 17b is attached to the inner circumference of the large diameter tube 16, and is fixed to the large diameter tube 16 by bolts 19b as described above.

The axial length of the small diameter cylinder 11) is the axial length of the large diameter cylinder 1
゜) It is desirable to design it so that it becomes larger.

The reason for this is that if the length of the insulating tube is set to 1□>1°, the surface leakage resistance of the large diameter tube will be smaller than that of the small diameter tube. That is, this is because flashing can occur on the outer surface side of the insulating cylinder.

The insulating cylinder 14 is made of an insulating material with low hygroscopicity such as epoxy resin or FRP, but its surface leakage resistance is
It is desirable that it be smaller than that of the auxiliary insulating layer 12.

The reason is the same as the above reason.

That is, when a lightning impulse enters the cable line, it flashes on the insulating tube 14 side, causing damage to the inside of the protective tube, especially
This is to reduce damage to the insulated connection portion 13 of the cable.

In any case, the performance required of the insulating cylinder is sufficient as long as it can maintain the required waterproof performance in the installed state since internal pressure such as hydraulic pressure is not applied at the cable connection part.

Note that the insulating tube 14 has a difference between the inner diameter (d2) of the large diameter tube 16 and the outer diameter (dl) of the small diameter tube 15, which is the difference between the first and second protection tubes 18.
It is desirable to design the wall thickness so that it is approximately equal to the wall thickness of b and 18a.

That is, by designing in this manner, the outer diameters of the first and second protective tubes can be made the same, and the finished outer diameter of the portions can be minimized.

In the figure, 20a and 20b are the outer semiconducting layers of the cable, and 21
22a and 22b indicate an insulating fluid such as insulating oil, and seal portions.

(Effects of the invention) In the present invention described above, the insulating tube is composed of a small diameter tube and a large diameter tube connected to the end of the insulating tube, so when forming a connection part of a rubber/plastic cable, Therefore, the finished outer diameter of the connecting portion can be made small without being over-designed, and the connecting portion can be formed at low cost.

In other words, the present invention eliminates the need for flanges at the ends of each protection tube, which were previously required, so the outer diameter can be reduced by that amount, and the mechanical properties required for the insulating tube are also lower than those required in the past. Compared to , it does not require a high degree of sophistication, so inexpensive materials can be selected.

[Brief explanation of drawings]

Fig. 1 is a partially omitted longitudinal sectional view of a conventional cable edge cutting connection, Fig. 2 is a partially omitted longitudinal sectional view of the cable edge cutting connection of the present invention, and Fig. 3 is an insulating tube used in the present invention. A vertical cross-sectional view is shown. 9...Edge cutting shielding layer, 12...Auxiliary insulating layer, 13...Insulated connection portion of cable, 14.
...Insulating tube, 15...Small diameter tube, 16...
...Large diameter cylinder, 18a, 18b...Protection tube.

Claims (1)

[Scope of utility model registration request] Rubber/plastic made by covering the outer periphery of the insulator connection part of a cable made by cutting the outer shielding layer with a edge-cut protection tube in which the openings of a pair of funnel-shaped metal tubes face each other and are connected via an insulating tube. In the cable edge cutting connection part, the insulating tube includes a small diameter part that fits into the opening of the metal tube and a large diameter part that is shorter than the small diameter part and fits around the outer periphery of the opening of the metal tube, and One opening of the pair of funnel-shaped metal tubes is fitted onto the small diameter portion of the insulating tube, and the other opening is fitted into the large diameter portion of the insulating tube so that they are connected to each other. Rubber/plastic cable edge cut connection.