Operating mechanism of miniature circuit breaker

Abstract

An operating mechanism of a small-size circuit breaker comprises a handle, a transmission rod, a support piece and a movable contact, wherein the support piece is arranged in a shell and can do rotation movement, the support piece and the movable contact are pivoted and arranged on the same common shaft, one end of a spring is fixed on a base, the other end of the spring is connected with the movable contact, the handle drives the support piece to rotate by the transmission rod, the support piece pushes the movable contact to rotate, and the movable contact can rotate around the same common shaft with the support piece and also can slide relative to the support piece. By the operating mechanism, the number of parts can be reduced, the manufacturing process can be reduced, e.g. an original over-range mechanism and an over-range spring are omitted, and the volume space of the circuit breaker can be further reduced.

Description

technical field [0001] The invention belongs to the field of low-voltage electrical appliances, and in particular relates to a small circuit breaker, in particular to an operating mechanism of the small circuit breaker. Background technique [0002] The operating mechanism is one of the necessary core components of the circuit breaker, which is used to drive the opening / closing of the moving contact and the static contact, and realizes the three basic functions of closing, opening and tripping of the circuit breaker by the opening / closing control. working status. With the continuous improvement of miniaturization and multi-functional use requirements, the use space limitation of miniature circuit breaker products is particularly prominent, and miniaturization is quite difficult. One of the reasons is that there are many parts in the operating mechanism, such as existing miniature circuit breakers. The operating mechanism of a circuit breaker generally needs to be provided w...

AI Technical Summary

Problems solved by technology

Furthermore, the moving contact of a circuit breaker usually requires two parts, one of which is a moving contact, and the other is a contact support for supporting the moving contact. If the volume of them and related parts is reduced and the compression parts The distance between them, such as compressing the space between conductive parts or the size of conductive parts, will lead to deterioration of electrical performance and safety performance, so this measure has a great risk and is not advisable

In addition, the overload tripping action of the bimetal in the prior art usually needs to act on the buckle through a linkage. The bimetal is connected to the lock through the linkage with one-way transmission, and the linkage and The transmission relationship between the locking parts has only one point of action of pulling (or pushing) force, so the free end of the linking part and the bimetal needs to reserve a large enough space for movement, otherwise the disengagement will be performed when the bimetal acts on the linking part. When the buckle trips, the bimetallic force often cannot fully act on the lock buckle, which will lead to unstable overload tripping protection performance

In addition, the contacts need to be welded with a support and then assembled with the support lever. Not only is the manufacturing process complicated, but the reliability is not high, and it also takes up a lot of space inside the product, hindering the miniaturization design of the product.

It can be seen that the re-miniaturization design of the operating mechanism on the premise of not reducing the product performance is one of the difficulties in realizing the re-miniaturization of circuit breakers, because the miniaturization design must also meet the requirements of easy large-scale, high efficiency and low cost. production, otherwise the market competitiveness of products cannot be effectively enhanced

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