Overload long delay protection mechanism

Abstract

The invention discloses an overload protection mechanism with long delay, connected in a circuit , and comprising a thermal deformation element and a trigger assembly. The thermal deformation element is connected in the circuit in series and comprises a first working surface (A) and a second working surface (B) which are not parallel. The trigger assembly is attached to a tripping mechanism and comprises a first trigger component and a second trigger component capable of moving in a translating motion relative to the thermal deformation element such that the trigger component and the thermal deformation element are in different relative positions. When no overload current exists in the circuit, the thermal deformation element and the trigger assembly are separated. When an overload current occurs, the thermal deformation element bends. Depending on the position of the trigger components relative to the thermal deformation element, the first working surface (A) comes in contact with the first trigger component or the second working surface (B) comes in contact with the second trigger component, causing the trigger component to trigger the release of the tripping mechanism, wherein either the first working surface (A) and the first trigger component or the second working surface (B) and the second trigger component are in contact, while the other is separated.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, more specifically, to an overload protection mechanism of a circuit breaker. Background technique [0002] At present, there are more and more demands for overload long-time delay adjustment of circuit breakers, such as molded case circuit breakers. Most of the existing long-time delay adjustment functions use a bimetallic component, such as a bimetallic A bimetallic sleeve and an adjusting screw are used to achieve this. There is an inclined surface on the bimetal sleeve, and different adjustment gears are obtained by using the relative positional relationship between the adjusting screw and the inclined surface. When the bimetal strip heats up and deforms, it will approach and finally push the adjusting screw, and the tripping part will be driven to trip by the adjusting screw. [0003] For example, CN87104289 discloses a circuit breaker that responds to abnormal currents in t...

AI Technical Summary

Problems solved by technology

[0008] In the various prior art solutions mentioned above, a slope and a screw are used, so it is difficult to ensure the accuracy of the long time delay in each gear position. Often, after a certain gear is calibrated, it is overloaded in another gear. The current setting value is not accurate, so this reduces the reliability of long-time delay adjustment to a certain extent

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