Operation mechanism of small-sized circuit breaker

Abstract

The invention discloses an operation mechanism of a small-sized circuit breaker. The operation mechanism of the small-sized circuit breaker comprises a handle, a transmission connection rod, a static contact, a dynamic contact, a tension spring, and a release lever. One end of the transmission connection rod is connected with a handle in a hinged manner, and the other end is cooperated with the dynamic contact. One end of the tension spring is fixedly disposed on the housing, and the other end is connected with the dynamic contact. The dynamic contact is driven by the tension spring and the transmission connection rod together, and contact pressure and over travel elastic force required by guaranteeing of electric contact reliability are provided for the closing of the dynamic contact and the static contact, and in addition, the tension is used to provide energy storage elastic force used for mechanism resetting required by the driving of the breaking of the dynamic contact and the static contact. The release lever is disposed on the dynamic contact, and is used to control the locking and unlocking cooperation between the transmission connection rod and the dynamic contact. The release lever is used to separate the transmission connection rod and the dynamic contact during occurrence of a fault, and then the operation mechanism is released automatically. The operation mechanism has advantages of effective structure simplification, production cost reduction, production efficiency improvement, and mechanism performance optimization.

Description

technical field [0001] The invention relates to an operating mechanism of a small circuit breaker, in particular to an operating mechanism suitable for a low-voltage molded case modularized small circuit breaker, and belongs to the field of low-voltage electrical appliances. Background technique [0002] As we all know, the operating mechanism of the miniature circuit breaker is used to drive the opening / closing of the moving contact and the static contact, and through the opening / closing, the closing, opening and tripping of the circuit breaker are controlled. The four-bar linkage mechanism is the most typical and commonly used mechanism for the operating mechanism of the existing miniature circuit breaker. It includes a handle connected with the transmission link to form a toggle; a rotating plate on a pivot; and a mechanical interlock (also commonly called a lock) that can be broken by the action of the trip bar, the bimetal is connected to the trip bar by a rotating link...

AI Technical Summary

Problems solved by technology

A feature of this mechanism is that the moving contact and the contact support are two independent components. In order to obtain the necessary overtravel function, an overtravel mechanism must be set between the moving contact and the contact support. For this reason, the moving contact The connection between the head and the rotating plate supported by the contact is generally adopted in two ways, one is glued or welded together, the disadvantage is that the process is complicated and the firmness is not reliable, and the other is to pass the moving contact through The torsion spring is fixed on the contact support, not on the rotating shaft of the operating mechanism. The disadvantage is that the rotating arm of the contact will be lengthened, and the action speed of the mechanism will slow down, which is not conducive to the circuit breaking performance of the product.

Moreover, the contact support in the four-bar linkage mechanism is generally fixed together with a rotating plate through a spring, and the contact support and the rotating plate can rotate in a small range to ensure the contact pressure and overtravel of the product. It can be seen that , the common problems of the existing method of fixing the moving contact on the contact support by welding or springs are that there are many parts, the structure of the transmission chain is complex, and the assembly and debugging are complicated, and the assembly efficiency is further reduced, which affects the miniaturization of the circuit breaker and low cost

In addition, the mechanical interlocking structure in the operating mechanism of the existing miniature circuit breaker is established on the transmission chain between the latch and the trip bar, and usually adopts a sharp tooth engagement (usually also called a hasp, etc.). The disadvantage of the tooth meshing structure is that the tines are prone to wear, which affects the reliability and service life of the product

Images