high-power DC electric appliance switch

Abstract

The invention discloses a high-power DC electric appliance switch, comprising: an arc extinguishing cover, under which an insulating bracket and a magnetic yoke located under the insulating bracket and above the coil are arranged; the outside of the arc extinguishing cover and the outside of the coil are surrounded by a metal sleeve; the arc extinguishing bracket and the magnetic yoke located above the coil are arranged below the insulating bracket. A pair of static contacts is matched with the arc extinguishing cover, and a movable contact assembly is arranged below the static contacts to contact or separate from the static contacts so as to turn on or off the switch of a DC electric appliance. A pair of permanent magnets each disposed between a side wall of the arc extinguishing cover and a side wall of the metal sleeve, and contacting the permanent magnets with the metal sleeve to increase magnetic field strength. The invention increases the magnetic field strength of the permanentmagnet through the design of the arc extinguishing structure, solves the ablation problem of the arc to the arc extinguishing cover, and makes the arc extinguishing gas more easily diffuse to the metal sleeve for heat dissipation, thereby prolonging the service life of the DC electric appliance switch.

Description

technical field [0001] The invention relates to the field of DC switches, in particular to high-power DC electrical switches. Background technique [0002] In recent years, with the development of new energy electric vehicles, charging piles and energy storage batteries, the application of high-voltage DC electromagnetic switches (high-voltage DC contactors and relays) has become more and more common, and has become Necessary electrical components for circuit on and off. The DC electromagnetic switch usually uses an electromagnetic system composed of a coil and an iron core as a control and execution component to drive the mechanism inside the switching device to make the dynamic and static contacts on or off to realize the switching function. [0003] Electrical switches generate arcs when breaking high-voltage and high-current circuits. Unlike AC, there is a zero-crossing point that is convenient for arc extinguishing, so DC arcs are more difficult to extinguish. The temp...

AI Technical Summary

Problems solved by technology

[0003] Electrical switches generate arcs when breaking high-voltage and high-current circuits. Unlike AC, there is a zero-crossing point that is convenient for arc extinguishing, so DC arcs are more difficult to extinguish. The temperature of the arc when it burns reaches several thousand degrees. Large damage, affecting the electrical life of the switch

[0004] In the existing DC switching technology, the permanent magnet is usually embedded in the arc chute, that is, the permanent magnet and the metal sleeve are separated by an insulating wall, and the magnetic field strength of the permanent magnet is relatively weak, which is not conducive to arc extinguishing

Since the arc is extinguished by permanent magnet or arc extinguishing gas, however, the magnetic field strength of the permanent magnet will irreversibly attenuate with the increase of temperature, which gradually reduces the arc extinguishing performance of the DC switch, and the arc extinguishing gas is usually sealed in It is difficult to dissipate heat quickly in the arc extinguishing chamber

In addition, the arc extinguishing gas and the metal sleeve are also isolated by the side wall of the arc extinguishing cover, and the arc is easy to directly ablate the side wall of the arc extinguishing cover to cause combustion or increase the impurities between the moving contact and the static contact to affect the product The switch-on of DC electrical appliances results in the problems of short electrical life and low reliability of DC electrical switches.

Images