JPH0348608B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to switching equipment equipped with bushings, such as breakers and load switches.

[Conventional technology]

Fig. 5 is a cross-sectional view showing an example of a three-phase AC switch and disconnector as a conventional switchgear, which is composed of an upper container 1, an intermediate container 2, and a lower container 3, and is used as an arc extinguishing medium.
A three-phase shearing unit as a three-phase opening/closing unit is housed in the container 4 filled with SF ₆ gas. The shear cutting unit 5 of each phase is fixed by bushings 6 sandwiched between the upper container 1 and the intermediate container 2 and between the intermediate container 2 and the lower container 3. This bushing 6 includes a conductor plate 8a,
8b and 8c are arranged and integrally molded with an insulating material such as epoxy. A flat portion 6a is formed on one surface of the bushing 6, and a convex portion 6b is formed on the other surface.

Next, the operation of the above configuration will be explained. Fifth
In the figure, the shear disconnection unit 5 of each phase is in a closed circuit state, and the current flows through the upper conductor plates 8a, 8b, 8.
c Pass through the mustard cutting unit 5 and lower conductor plate 8
a, 8b, and 8c, and electrical insulation between each phase is provided by the convex portion 6b of the bushing 6 located between each phase. When an opening command is given to the three-phase AC sheath breaker in this state, the movable contact 13 of the sheath breaker unit 5 separates from the fixed contact 10, and the sheath breaker unit 5 is opened. Dielectric breakdown between each phase due to decomposition gas generated by the arc energy generated at this time is mainly prevented by the convex portion 6b.

[Problem that the invention seeks to solve]

Conventional switchgear devices such as three-phase AC switches and disconnectors are constructed as described above, and in order to prevent dielectric breakdown due to the generation of decomposed gas, the insulation distance between each phase must be set at a predetermined value or more. Plane part 6a
It is necessary to considerably increase the length of the convex portion 6b. Therefore, the overall shape of the upper and lower bushings 6 must be increased, which necessitates increasing the size of the entire three-phase AC disconnector. In addition, due to the arc generated when the current in the shearing unit 5 is cut off, the fixed contact 10 and the movable contact 1
The metal 3 is melted, and the molten metal floats in the container 4, and is finally deposited on the upper surface of the fixed contact 10 of the cutting unit 5, the flat surface 6a of the bushing 6, etc. Since this substantially reduces the insulation distance along the surface of the bushing 6, the distance between the bushings 6 must be increased and the bushing 6 must be made larger, resulting in a larger overall device size. There was a problem with not being able to get the desired results.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an opening/closing device that can reduce the size of the entire device by making the bushing itself smaller.

[Means for solving problems]

The opening/closing device according to the present invention has a convex portion formed on the upper side of the bushing located between each phase, and a recessed portion formed on the lower side.

[Effect]

In this invention, the distance along the surface of the bushing between each phase is increased, and the substantial insulation distance between the phases is increased. Also, no metal melt is deposited on the surface of the bushing.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show one embodiment of the present invention, and the same or corresponding parts as in FIG. 5 are designated by the same reference numerals, and the explanation thereof will be omitted. Bushing 1
6, as shown in FIG. 2, is integrally molded with an insulating material such as epoxy. The ends of the bushing 16 are provided with terminals 11a, 11b, 11c electrically connected to the conductor plates 8a, 8b, 8c. Holes 12a, 12b, 1 are provided in the conductor plates 8a, 8b, 8c.
2c are formed, and these holes 12a, 12
Fixed contacts 10 are attached to b and 12c. Fixed contact 10 Cutter cutting unit 5
It is electrically connected to the movable contact 13 of.

In the bushing 16, a convex portion 14 is provided at both the upper and lower portions between the container 4 and the sheath cutting unit 5.
is formed. A triangular convex portion 15 is formed on the upper part of the bushing 16 between each phase. A recess 17 having a V-shaped cross section is formed in the lower part of the bushing 16 between each phase.

Next, the operation of the above configuration will be explained. 1st
In the figure, the insulation unit 5 of each phase is in a closed circuit state,
The insulation between the shear cutting unit 5 and the container 4 is provided by the convex portion 1.
4 is maintained. Further, insulation between each phase is maintained by the convex portions 15 and the concave portions 17. When an opening command is given to the three-phase AC switch and disconnector in this state, the fixed contact 10 and the movable contact 13 are separated, and an arc is generated between the two contacts 10 and 13 and extinguished. The arc extinguishing gas decomposed by the arc energy at this time diffuses in various directions,
Dielectric breakdown between the phases due to this decomposed gas is prevented by the action of the convex portions 15 and concave portions 17, which have a large distance along the surface of the bushing 16 between the phases. Insulation between the insulation unit 5 and the container 4 is also prevented by the convex portion 14. Furthermore, the metal of the fixed contact 10 and the movable contact 13 is melted by the arc generated when the current in the shearing unit 5 is cut off, and the molten metal floats in the container 4. Although this floating matter accumulates on the lower container 3, the upper surface of the fixed contact 10, etc., it does not accumulate at the locations between each phase of the bushing 16 due to the action of the convex portion 15, and the insulation distance between each phase is substantially reduced. do not.

In addition, in the above embodiment, a three-phase AC switch and disconnector in which each phase is arranged in a straight line in the horizontal direction has been described, but the fourth embodiment
As shown in the figures, the sheath cutting units may be secured to the circular bushing 18 in a triangular arrangement. In this case as well, a convex portion 19 is formed on the upper side of the bushing 18 between each phase, and a concave portion (not shown) is formed on the lower side of the bushing 18 corresponding to this convex portion 19. Further, in both the first and second embodiments, the case of a three-phase AC switch or disconnector has been described, but the present invention is not limited to a three-phase AC switch or disconnector, and for example, the case where a load It can also be applied to switches such as switches and disconnectors. Furthermore, although the recess 17 has been described as having one V-shaped cross section, a plurality of recesses 17 may be formed.

〔Effect of the invention〕

As explained above, according to the present invention, by forming a recess on the upper side between each phase of the bushing and forming a recess on the lower side, a large distance can be secured between each phase along the surface of the bushing. The substantial insulation distance between the phases is increased, the dimension between the phases of the bushing can be reduced, and the entire switching device can be downsized. In addition, since a convex portion is formed on the upper side between each phase of the bushing, molten metal that is generated when an arc occurs does not accumulate between each phase of the bushing, and the insulation performance due to the molten metal between each phase is reduced. There is no risk of it happening.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a sectional view, FIG. 2 is a sectional view taken along the - line in FIG. 1, and FIG. −
FIG. 3 is a cross-sectional view taken along a line. FIG. 4 is a plan sectional view of a main part showing another embodiment of the present invention. Fifth
The figure is a sectional view showing an example of a conventional three-phase AC switch and disconnector. 4... Container, 5... Shrinking unit (opening/closing unit), 15, 19... Convex portion, 16, 18... Butching, 17... Concave portion. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A three-phase opening/closing unit is placed in a container containing an arc-extinguishing medium, and this opening/closing unit is fixed in the container,
A switchgear device comprising a bushing for forming electrical insulation between each phase, characterized in that the bushing is provided with a convex portion on the upper side and a recess on the lower side between the respective phases. device.