JPS62254326A - Switchgear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a switching device, and more specifically, a permanent magnet used for arc extinguishing is provided in a nozzle portion provided at an insertion/extraction portion of a movable contact. Regarding switchgear.

[Prior Art] Conventionally, a switchgear having an arc extinguishing chamber as shown in Fig. 2 has been used as a switchgear that extinguishes an arc generated between contacts by applying a magnetic driving force to the arc using a permanent magnet. In Figure 0, a fixed contact (2) and a nozzle (3) are attached to a fixed contact terminal plate (1). A permanent magnet (4) is placed around the opening (3a) of the nozzle (3).
is attached, and this permanent magnet (4) provides a magnetic driving force to the arc (6) generated between the fixed contact (2) and the movable contact (5). The movable contact (5) is electrically connected to a slide contact (7) attached to a movable contact terminal plate (8).

In the switchgear shown in Figure 2, current passes through the fixed contact side terminal plate (1), fixed contact (2), movable contact (5), slide contact (7), and movable contact side terminal plate (8). flows. When the current is cut off, the movable contact (5) is pulled out from the nozzle (3), and the arc (6) generated at this time is caused by the permanent magnet (
The arc is extinguished by receiving magnetic driving force from 4).

[Problems to be solved by the invention] However, since conventional permanent magnets are exposed to the atmosphere of the arc extinguishing chamber as shown in Figure 2, the arc generated when the current is cut off passes through the creeping surface outside the nozzle and is permanently damaged. Harmful gases, metal powders, etc. that reach the magnet or are generated when atmospheric gas is decomposed by the arc come into contact with the permanent magnet. Therefore, the permanent magnet is gradually chemically eroded and its magnetic force is reduced, resulting in a problem that the arc-extinguishing force of the switchgear is reduced.

The object of the present invention is to solve the above-mentioned problems and to obtain a highly reliable switching device that has excellent arc-extinguishing performance and whose arc-extinguishing power does not easily decrease.

[Means for Solving the Problems] A switchgear according to the present invention houses a pair of contacts consisting of a fixed contact and a movable contact in an arc extinguishing chamber, and the fixed contact has the movable contact along its inner surface. It is surrounded by a nozzle that has an opening that can be inserted and extracted, and this nozzle contains a permanent magnet that provides a magnetic driving force for the arc, and a sealing material that prevents it from coming into contact with the arc or harmful substances generated when atmospheric gas is decomposed by the arc. It is designed to withstand heavy loads.

[Function] In the switchgear according to the present invention, the arc generated between the movable contact and the fixed contact when the movable contact is pulled out from the nozzle during current cutoff receives magnetic driving force from the permanent magnet embedded inside the nozzle. However, since the permanent magnet is sealed in the nozzle with a shielding material, the permanent magnet is prevented from coming into contact with the arc or harmful substances generated by the decomposition of atmospheric gas by the arc.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows the arc extinguishing chamber of the breaker according to the present invention,
A fixed contact (2) and a nozzle (3) are attached to the terminal plate (1) on the fixed contact (2) side. The nozzle (3) is provided with a permanent magnet (4) and sealed with a sealing material. A slide contact (7) is attached to the movable contact side terminal plate (8) to provide electrical continuity between the movable contact (5) and the movable contact side terminal plate (8).

In the breaker shown in Fig. 1, current flows from the fixed contact side terminal plate (1) through the fixed contact (2), the movable contact (5), and the slide contact (7) to the movable contact side terminal plate (8). flows. When the current is cut off, the movable contact (5) moves to the left in the figure and is pulled out from the nozzle (3). The arc (6) generated at this time is extinguished by receiving magnetic driving force from the permanent magnet (4). The permanent magnet (4) provided around the opening of the nozzle (3) is sealed with a chemically stable sealing material such as plastic, and is protected against arcs (6), harmful gases generated when the current is interrupted, metal powder, etc. Since there is no contact with the magnetic field, there is no decrease in magnetic force, and high arc-extinguishing performance is maintained.

[Effects of the Invention] The switchgear of the present invention has the above configuration, and since the permanent magnet provided in the nozzle is sealed with a sealing material, arcs and Does not come into contact with harmful gases or metal powders generated by gas decomposition,
Since a decrease in magnetic force does not occur, the arc extinguishing ability of the switchgear can be maintained at a high level.

[Brief explanation of drawings]

FIG. 1 shows a magnet! which is an embodiment of the present invention. FIG. 2 is a diagram showing the arc extinguishing chamber of a conventional magnetically driven circuit breaker. In the figure, (2) is a fixed contact, (3) is a nozzle, (3a) is a nozzle opening, (4) is a permanent magnet, (5) is a movable contact, and (9) is a sealing material. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A pair of contacts consisting of a fixed contact and a movable contact that can be moved into and out of contact; a nozzle that surrounds the fixed contact and has an opening through which the movable contact is inserted and extracted along the inner surface of the nozzle; A permanent magnet provided and sealed by a sealing material.