JPH0416599Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an improvement of a push pipe for a cable termination box.

[Technical background of the invention and its problems] An example of a conventional cable termination box will be explained with reference to FIG. 2A. Figure 2 shows a termination box for CV cables used for 66Kv or higher. This termination box consists of an epoxy sleeve 2 attached to the bottom plate 1 of the equipment, and a conductor pull-out rod 3 fixed to the upper end of the sleeve.
and a cable protection fitting 5 connected to the lower end of the sleeve 2 via an insulating tube 4, and a conductor 7 of the cable 6.
is connected to the inner end of the conductor pull-out rod 3. The insulating tube 4 is used to electrically insulate the ground on the cable sheath side connected to the cable protection fitting 5 from the ground on the device case. In addition, in the figure, 8 is a stress cone, and 9 is a push pipe that presses this. Further, in order to obtain the above-mentioned insulation within the termination box, the push pipe is made of an insulating material.

In the conventional termination box having the above structure, the push pipe 9 has the structure shown in FIG. 2B. That is, the outer circumferential surface has a three-step stepped cylindrical shape, and the inner circumferential surface has a tapered hole that widens toward the large diameter end and a straight hole connected to the tapered hole, and is made by integral molding from FRP. ing. The above-described shape is intended to sufficiently withstand the spring force that presses the push pipe against the stress cone, and to maintain electrical properties.

In order to manufacture a push pipe with the above structure by integral molding using FRP, an inner mold for molding is required, which is not suitable for mass production and is expensive.

[Purpose of the invention] The invention was created based on the above circumstances.
The object of the present invention is to obtain a push pipe for a cable termination box that has high mechanical strength, sufficient electrical properties, and can be manufactured at low cost.

[Summary of the invention] The push pipe for the CV cable termination box of this invention is
It is characterized by having an insulating layer coated on the outer peripheral surface of a metal base body having a tapered part that widens toward one end and a straight part connected to the tapered part.

[Embodiment of the invention] FIG. 1 is a sectional view of the main part of an embodiment of the invention. In this figure, the push pipe 9 of the present invention is A
An insulating layer 9b is coated on the outer circumferential surface of the metal push pipe base 9a, which is made of a first grade metal and consists of a tapered part that widens toward one end and a straight part connected to this, by coating with PVC dipping or pasting of FRP. It is configured.

As explained above, since the push pipe of the present invention is constructed by covering the metal base 9a with the insulating layer 9b, it has high mechanical strength and is sufficient to withstand the spring force that presses the pipe against the stress cone. I can endure it. Furthermore, since its outer peripheral surface is covered with an insulating layer, it exhibits sufficient dielectric strength against surge voltage and has good electrical characteristics.

[Effects of the Invention] As is clear from the above, the push pipe for a cable termination box of the present invention is manufactured by coating a metal base with an insulator. The base can be easily manufactured by processing a metal pipe, and the outer circumferential surface of the base can be easily coated with an insulating material. It can be mass-produced relatively easily and can be supplied at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of an embodiment of the present invention;
FIG. 2A is a sectional view showing an example of a conventional termination box, and FIG. 2B is a sectional view of a push pipe used therein. 1...Equipment bottom plate, 2...Epoxy sleeve, 3...
Conductor pull-out rod, 4... Insulating tube, 5... Cable protection fitting, 6... Cable, 7... Cable conductor, 8
...Stress cone, 9...Push pipe, 9a...
...Substrate, 9b...Insulating layer.

Claims (1)

[Scope of utility model registration request] A push pipe for a cable termination box, characterized in that the outer circumferential surface of a metal base body has a tapered part that widens toward one end and a straight part connected to the tapered part, and an insulating layer is coated on the outer peripheral surface of the metal base body.