JPH026575Y2 - - Google Patents

Description

[Detailed description of the invention] A. Field of industrial application The present invention relates to the improvement of a bushing for a switch equipped with a voltage detection terminal, and particularly relates to the attachment of a voltage detection electrode and the electrical connection between the electrode and the voltage detection terminal. This relates to a structure that ensures reliable contact.

(b) Prior Art and Purpose of the Present Invention In modern high-voltage power distribution lines, so-called maintenance work such as relining electric wires, upgrading electrical equipment, and replacing support insulators is performed in order to improve the reliability of power supply. This is done without power outages. This was done by temporarily installing a bypass line (line) for customers existing within the construction area, so that electricity could continue to be transmitted through this line during the construction period. A construction switch is used to form the bypass line, and its bushing is provided with a voltage detection terminal for detecting whether or not the high voltage circuit (line) is charged. The voltage detecting electrode of the voltage detecting terminal portion is often embedded integrally in a bushing made of an insulating material such as epoxy resin, or adhesively fixed to the outer peripheral surface of the bushing with an adhesive.
Therefore, the former has problems such as cracks occurring in the bushings due to the difference in thermal expansion coefficients, while the latter also has problems such as peeling due to the difference in thermal expansion coefficients and voltage detection electrodes falling off due to poor adhesion. .

This proposal is aimed at solving these problems.
The present invention proposes a structure in which attachment of a voltage detection electrode and electrical contact between the electrode and a voltage detection terminal can be performed simultaneously and reliably.

C. Composition of the Proposal Therefore, in the present Proposal, a plate-shaped voltage detecting electrode is wound around the outer circumferential surface of a bushing made of an insulator into which a central conductor is inserted and fixed, so that the ends thereof overlap. At the same time, the overlapping part of the voltage detecting electrode is screwed to the lower part of the insulating jacket which is attached and fixed to the outer periphery of the electrode so as to surround the electrode. The hollow hole at the tip of the voltage detection terminal is pressed by the tip of the voltage detection terminal integrated with the guide member, and the metal interposed in a compressed state between the terminal and the voltage detection electrode is further inserted into the hollow hole at the tip of the voltage detection terminal. This paper proposes a structure for a bushing in a construction switch, which is characterized by a built-in coil spring.

D. Example 1 shows a construction switch equipped with the bushing of the present invention, in which a plurality of (three-phase) bushings 3 are attached to the front face 2a of the case 2 by means of flange fittings 4. 5 is a bolt for attaching the bushing, 6
indicate nuts respectively. Reference numerals 7 and 8 indicate mounting brackets for attaching to a utility pole, and a mounting bracket 7 for attaching a arm arm is provided on the top surface 2b of the case, and a mounting bracket 8 for direct attachment to a utility pole is provided on the side surface 2c of the case, which is temporarily installed on a utility pole 9. If so, use only one of them. 10 indicates an operating handle for opening and closing.

Reference numeral 3 denotes a bushing made of an insulating material such as porcelain or epoxy resin that is attached to the inside and outside of the case 2, and a center conductor 11 made of a good electrical conductor such as copper is inserted and fixed in the center. There is.

Reference numeral 11d indicates a tube-shaped contact portion 12 at the tip of the conductor, and reference numeral 13 indicates an insulating insertion guide 14 attached to the tip of the bushing. The connecting conductor is tightened, 4 is a flange fitting for mounting the case fixed to the flange 4a protruding from the center of the bushing with an adhesive 18, and 19 is a rubber gasket.

20 is the outer peripheral surface 3 of the bushing located in the case
It is a voltage detecting electrode made of a thin plate metal such as stainless steel, brass, or copper that is tightly wound around a with an adhesive 21 interposed therebetween. I try to come. Reference numeral 22 denotes a cylindrical insulating covering tube made of epoxy resin, vinyl chloride resin, etc., which is tightened and fixed between the flange metal fitting 4 and the holding metal fitting 23 so as to surround the outer periphery of the voltage detecting electrode. A hole 22a and a cutout 22b for draining water are formed. 24 indicates a nut for tightening and fixing the covering tube. Reference numeral 25 denotes a tip portion 26a of a voltage detecting terminal 2b which is integrally protruded and fixed to a threaded portion 25b formed on the upper outer periphery of the screw hole 22a of the covering tube.
This is a funnel-shaped guide member made of synthetic resin that is pressed and fixed to the overlapping part A of the voltage detecting electrodes, and a lower guide part is provided to facilitate contact with the voltage detecting terminal 26 by the voltage detector 27. The lower end of 25b is expanded into a flap shape. Reference numeral 28 denotes a metal coil spring which is compressed and installed in a hollow hole 26b consisting of a blind hole formed in the tip end 26a of the voltage detection terminal. In order to compensate for this, the overlapping portion A of the voltage detection electrodes is extended by that amount and continues to be pressed, and electrical contact is maintained between the voltage detection electrodes and the voltage detection terminals. 29 is the inner circumferential surface 29b of the covering cylinder and the outer circumferential surface 3a of the bushing.
This shows the epoxy resin filler filled into the void (g) formed by

E. Effects of the Proposal As described above, the structure of the bushing in the construction switch of the present invention is such that a plate-shaped voltage detecting electrode is attached to the outer circumferential surface of the bushing, which is made of an insulator through which the central conductor is inserted and fixed. The ends are wound so that they overlap each other, and the overlapping parts are tightly fixed with an adhesive so that they are positioned downward, and the overlapping parts of the voltage detecting electrodes are attached to the outer periphery of the electrodes so as to surround the same electrodes. When pressed by the tip of the voltage detection terminal integrated with the guide member screwed onto the lower part of the fixed insulating sheathing tube, the hollow hole at the tip of the voltage detection terminal As a result of installing a metal coil spring interposed in a compressed state between the voltage detection electrode and the voltage detection electrode, the voltage detection electrode is attached to the outer circumferential surface of the bushing by the adhesive, the voltage detection terminal, and the coil spring attached to the terminal. Not only can the installation be made more secure because the bushings are bonded and pressed in multiple layers, but also in the unlikely event that these bushings, voltage detection electrodes, and voltage detection terminals are bonded to each other due to the difference in their thermal expansion coefficients. Even if the terminal peels off or the voltage detection terminal and the voltage detection electrode become separated, the voltage detection terminal is equipped with a compressed metal coil spring as described above, so the spring will continue to detect voltage. The feature is that the press-fixing of the test electrode and the electrical contact between the electrode and the voltage detection terminal can be carried out continuously.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention, in which FIG. 1 is a front view of a construction switch, FIG. 2 is a side view, and FIG. 3 is an enlarged vertical sectional view of the bushing part. FIG. 4 shows enlarged cross-sectional views of the portions pressed and fixed by the voltage detection terminals. 3... Bushing, 3a... Outer peripheral surface, 11... Center conductor, 20... Electrode for voltage detection, 20a, 20b... End portion,
21...Adhesive material, 22...Coating cylinder, 22a...Screw hole,
25... Guide member, 25a... Screw part, 25b... Guide part, 26... Voltage detection terminal, 26a... Tip part, 26b
...Hollow hole, 28...Coil spring, A...Overlapping part

Claims (1)

[Scope of utility model registration request] A plate-shaped voltage detecting electrode is wound around the outer circumferential surface of a bushing made of an insulator into which a central conductor is inserted and fixed, so that the ends thereof overlap, and an adhesive is applied so that the overlapping part is located downward. The overlapping part of the voltage detection electrodes is screwed onto the lower part of the insulating covering tube which is attached and fixed to the outer periphery of the voltage detection electrodes so as to surround the electrodes. In addition to being pressed by the tip, the hollow hole at the tip of the voltage detection terminal is further equipped with a metal coil spring interposed in a compressed state between the terminal and the voltage detection electrode. The structure of the bushing in the construction switch.