An arc extinguishing structure of a DC small circuit breaker

Abstract

The invention relates to an arc extinguishing structure of a DC small circuit breaker. The circuit breaker comprises a base and a base cover. The base is provided with a static contact and a movable contact; also includes two permanent magnet arc extinguishing devices. Two permanent magnet arc extinguishing devices are respectively installed on the base and the base cover. The permanent magnet arcextinguishing device comprises an arc separating plate, a magnetic guide plate and a permanent magnet. The permanent magnet is fixed in a hole on the magnetic guide plate. The arc separating plate isfixed on one side of the permanent magnet; an arc ignition plate is also installed in the base; One end of the arc ignition plate is positioned on the side of the contact of the static contact; Whenthe base cover covers the base, two permanent magnet arc extinguishing devices are positioned opposite to each other, and the movable contact, the static contact and the arc ignition plate are positioned between the two permanent magnet arc extinguishing devices. The invention effectively solves the problem of long arc burning time of the DC circuit breaker, shortens the breaking time of the circuit breaker, and is favorable for improving the short-circuit breaking capacity of the circuit breaker.

Description

technical field [0001] The invention relates to a circuit breaker, in particular to an arc extinguishing structure for a DC small circuit breaker. Background technique [0002] When the circuit breaker is opened, when the moving contact and the static contact first separate, the gap is very small, the electric field strength is extremely large, and high heat and strong field are easily generated. The free electrons in the metal escape from the surface of the cathode and rush to the anode. . At the same time, the free electrons hit neutral gas molecules in the electric field to excite and dissociate them, producing positive ions and electrons. When the electrons continue to move to the anode under the action of a strong electric field, they also hit other neutral molecules. Therefore, in the dynamic contact A large number of charged particles of positive ions and electrons are generated in the gap between the head and the static contact, which makes the gas conduct electrici...

AI Technical Summary

Problems solved by technology

The current commonly used arc extinguishing method is to introduce the generated arc into the arc extinguishing chamber through the arc striker for arc extinguishing, but there are defects such as weak arc guidance, long arc extinguishing time, and poor arc extinguishing effect, resulting in insufficient breaking capacity of the circuit breaker. high

Images