JPS6237295Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the provision of an improved multi-circuit switch, in particular in a miniaturized one in which the electrodes which are opened and closed by a movable electrode of a fixed electrode are arranged close to each other. It is an object of the present invention to provide a multi-circuit switch of this type which is safe and highly reliable, and which allows voltage detection between electrodes to be carried out reliably without any trouble.

In recent years, high-voltage cabinets with built-in multi-circuit switches and disconnectors for branching high-voltage underground power distribution systems in urban areas have been installed above ground on public roads, and for this reason, they have been designed to be small and compact so as not to obstruct traffic. This must be configured with safety in mind. Therefore, it is required that the distance between the electrodes of the multi-circuit switch to be opened and closed be made as small as possible, and that the multi-circuit switch can withstand a predetermined high voltage.

FIG. 1 illustrates a switch used in a multi-circuit switch that has already been developed in the past, with reference numeral 5 indicating a fixed electrode and 8 indicating a movable electrode.

The fixed electrode 5 includes a plurality of common electrodes 1 arranged in a horizontal row at equal intervals and branch electrodes 3 with connecting terminals also arranged in a horizontal row at equal intervals, each pole having a pair of open/close poles. They are arranged in an orderly manner vertically and horizontally so that
These electrodes 1 and 3 are integrated with a plate-shaped solid insulator 4 formed by molding. The common electrode 2 is a bus bar 2 embedded in a solid insulator 4.
They are electrically connected to each other by being connected to each other, and the contact portion of each pole projects above the solid insulator 4. One of the branch electrodes 3 is independent, with a connecting terminal portion protruding from the bottom of the solid insulator 4 to serve as a terminal connection for an underground power distribution cable, and a contact portion protruding from the top of the solid insulator 4. ing.

The movable electrode 8 has contact portions at both ends of a U-shaped conductive rod, and the conductive portion other than the contact portions is embedded in a solid insulator.

Therefore, by inserting the contacts at both ends of the conductive rod of the movable electrode 8 into the contacts of the common electrode 1 and the branch electrode 3, which face each other as a pair, and bridging those electrodes, the electrodes can be closed. If this is achieved and the movable electrode 8 is removed, the gap between the electrodes will be opened. This movable electrode 8 is provided for each opposing pair of the common electrode 1 and the branch electrode 3, and if there are five electrode pairs as shown in the figure, five movable electrodes are provided.

By connecting the distribution side cable to the connection terminal of any one of the plurality of branch electrodes 3 and connecting the distribution side cable to the connection terminal of the remaining electrodes, the branch electrode → movable electrode is connected as seen from the main line side. → common electrode → via busbar branch electrode,
It will be forked.

The switch in FIG. 1 is shown for one phase, and a multi-circuit switch is constructed by providing this switch for the number of phases.

Figure 2 shows a multi-circuit switch incorporating three switches, in which the conductors of each phase R, S, and T of a three-phase three-wire cable are connected to the branch electrodes of each switch. consists of things.

FIG. 3 is a plan view of a multi-circuit switch showing a modification of the one shown in FIG. It is composed of According to this multi-circuit switch, the width of the fixed electrode 5 in the depth direction (vertical direction on the paper) can be made small without increasing the width in the horizontal direction, and the frame 9 can be made smaller.

In this way, special consideration has been given to miniaturizing conventional multi-circuit switches, but as a result, the in-phase poles are arranged close together, so the facing distance is shortened and the voltage is applied. Since the stray capacitance between the electrodes increases, even though it is in a circuit state,
There was a tendency for voltage to be induced between the common electrode 1 and the branch electrodes 3.

Generally, when performing electrical work on a high-voltage power distribution system, use a voltage detector to check whether voltage is applied to the system and the line is live, or visually check the status of indicators and contacts. We are working hard to prevent accidents.

However, if the distance between the in-phase electrodes is small as described above, even if the movable electrode 8 is removed and the circuit is opened, the voltage induced between the common electrode 1 and the branch electrode 3 may cause the voltage detector to accidentally light up. Therefore, there was a possibility that the circuit could be mistakenly thought to be closed even though it was open, which could hinder maintenance work.

In view of the problems of the prior art described above, the present invention
The object of the present invention is to provide a multi-circuit switch of this type which is improved so that the induced voltage to the electrode in an open state is sufficiently reduced, safety is ensured, and maintenance work is not hindered.

That is, in the multi-circuit switch of the present invention, a cylindrical hole defined by a rounded peripheral wall surface is formed in the solid insulator portion between the common electrode and the branch electrode, which face each other and form a pair. The switch is constructed by providing a conductive layer on the surface of the solid insulator and the peripheral wall surface of the hole.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 and 5 show preferred embodiments of the multi-circuit switch according to the present invention, and the same parts as in FIG. 1 are given the same reference numerals for easy understanding. It is shown in

The electrode arrangement of the fixed electrode 5 and the structure of the movable electrode follow the structure of the compact multi-circuit switch shown in FIG. That is, the fixed electrodes 5 are connected to a plurality of common electrodes 1 which are arranged in a horizontal row at equal intervals and are electrically connected to each other by the bus bar 2, and the cable connection is also arranged in a horizontal row at equal intervals. Branch electrodes 3 with terminals are arranged diagonally facing each other in an orderly manner so as to form a pair of open/close poles for each pole, and these electrodes 1 and 3 and the bus bar 2
is embedded and integrated into a solid insulator 4 formed into a plate shape by molding.

The contact portions of the common electrode 1 and the movable electrodes 8 of the branch electrodes 3, which serve as insertion contact portions, are exposed in a cylindrical portion protruding from the top of the solid insulator, and
Each independent branch electrode 3 has a cable connection terminal portion protruding from the lower part of the solid insulator 4, and serves as a terminal connection portion of an underground power distribution cable.

The movable electrode 8 is formed by having contacts at both leg ends of a substantially U-shaped conductive rod, and the conductive portion other than the contact portion being buried in a solid insulator.

Therefore, opening between the electrodes is achieved by inserting and bringing the contacts at both ends of the conductive rod of the movable electrode 8 into contact with the respective contact portions of the pair of common electrode 1 and branch electrode 3; If the electrode is removed to release the condition, the gap between the electrodes can be opened. This movable electrode 8 is provided for each opposing pair of the common electrode 1 and the branch electrode 3,
If there are five electrode pairs as shown in the figure, five movable electrodes are provided.

By terminating the trunk side cable to the connection terminal of any one of the plurality of branch electrodes 3 and connecting the distribution side cable to the connection terminal of the remaining branch electrodes, the branch electrode → It branches along the path of movable electrode → common electrode → bus bar → branch electrode.

In the fixed electrode 5 forming such an electrode arrangement, the present invention has a cylindrical hole 6 in the solid insulator between the common electrode 1 and the branch electrode 3 which face each other and form a pair.
, and a conductive layer 7 is provided on the surface of the solid insulator 4 and the rounded peripheral wall surface of the hole 6.

Such a conductive layer 7 can be formed by vapor deposition of a conductive metal, application of a metal paint, or the like.

The conductive layer 7 provided as described above is grounded by making it conductive to the metal part of the storage cabinet in the layer applied to the outer surface of the solid insulator, and is then applied to the peripheral wall surface inside the hole 6. The portion of the conductive layer that has been removed is also set to ground potential.

As a result, the space between the common electrode 1 or bus bar 2 and the branch electrode 3 is electrically shielded by the conductive layer of ground potential applied to the peripheral wall surface inside the hole 6, so even if it is opened, The induced voltage from the common electrode 1 in the charged state to the branch electrode 3 in the open state is reduced to a low value without causing any problems. Furthermore, since the conductive layer 7, which is also grounded on the surface of the solid insulator 4, forms an electrical shielding layer, the induced voltage from the bus bar 2 to the adjacent fixed electrode can be sufficiently reduced. .

Since the hole forming the surface for providing the internal conductive layer to be interposed between the electrodes is shaped like a cylinder and has a rounded peripheral wall surface, the stress received when the solid insulator 4 contracts during molding is reduced. It can be relaxed without becoming large, and it can also have the ability to withstand thermal and mechanical influences.

As is clear from the above explanation, the multi-circuit switch of the present invention is made compact by forming holes in the solid insulator between the electrodes that are close enough to generate an induced voltage even in an open circuit state. Since a conductive layer is provided and grounded on the rounded peripheral wall surface within the hole, the induced voltage from the common electrode to the open branch electrodes is sufficiently reduced, and therefore the charging state can be detected by a voltage detector. The present invention provides a multi-circuit switch of this type which can accurately and safely perform confirmation, is compact, easy to maintain, and highly reliable, and has great practical effects.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a switch in a conventional multi-circuit switch, and Fig. 2 is a perspective view showing an example of a switch in a conventional multi-circuit switch.
FIG. 3 is a plan view showing a modified example of the multi-circuit switch, and FIG. 4 is a perspective view showing an embodiment of the switch in the multi-circuit switch according to the present invention. FIG. 5 is a vertical sectional view of the fixed electrode shown in the same figure. 1: common electrode, 2: bus bar, 3: branch electrode,
4: solid insulator, 5: fixed electrode, 6: hole, 7: conductive layer, 8: movable electrode, 9: frame.

Claims (1)

[Scope of utility model registration request] A plurality of common electrodes arranged in a horizontal row and electrically connected to each other and a plurality of independent branch electrodes arranged in a horizontal row opposite to each of the plurality of common electrodes are molded into a plate shape. It consists of a fixed electrode integrated with a solid insulator, and a plurality of fixed movable electrodes that removably connect a plurality of common electrodes and a plurality of branch electrodes of the fixed electrode to each pair of opposing electrodes. In a multi-circuit switch equipped with a plurality of switches, a cylindrical shape defined by a rounded peripheral wall surface is formed on the solid insulating part between the common electrode and the branch electrode, which face each other and form a pair. 1. A multi-circuit switch, characterized in that a hole is formed, and the switch is constructed by providing a conductive layer on the surface of a solid insulator and on the peripheral wall surface of the hole.