Miniature circuit breaker with high breaking capacity

Abstract

The invention discloses a miniature circuit breaker with a high breaking capacity, which comprises a shell, wherein the shell is internally provided with a magnet yoke assembly, a moving contact assembly, an arc extinction system and an actuating mechanism. A magnet yoke, a wiring board and a connecting sheet in the magnet yoke assembly are designed into a whole to ensure that the structure of the magnet yoke assembly is simplified, the quantity of soldered dots of the magnet yoke assembly is reduced and the internal resistance of a circuit breaker is lowered; a moving contact in the moving contact assembly comprises a contact support and a contact which are connected, the specific gravity of the contact support is smaller than that of the moving contact, and a magnet conductive plate is additionally arranged on the back of the moving contact and used for accelerating the transfer of an electric arc, therefore, the breaking capacity of the circuit breaker is improved; and a plurality of linkage lug bosses used for multipolar linkage are arranged on a contact support body, thus the linkage performance of the multipole circuit breaker is effectively ensured. A coil is connected with the moving contact through an annealed copper wire in a spot welding manner, and the soldered spots are moved from the linkage lug bosses to the moving contact without influencing the linkage property of the multipole circuit breaker. The invention has the advantages of high breaking capacity, high consistency of the interelectrode linkage and good reliability performance.

Description

technical field [0001] The invention relates to the field of low-voltage electrical appliances, in particular to a small circuit breaker. Background technique [0002] Small circuit breakers usually have short-circuit current protection function and overload current protection function. The overload protection function is realized by the induction and bending of the thermal bimetal to push the circuit breaker mechanism to disconnect the current loop. The short-circuit protection function is realized by the components including coil, armature and yoke The formed electromagnetic release induces and establishes a magnetic field so that the armature moves and pushes the circuit breaker mechanism to disconnect the current loop. The existing miniature circuit breakers have the following disadvantages: [0003] (1) The magnetic yoke element of the existing small circuit breaker mainly includes a magnetic yoke, a connecting piece, and a wiring board. The magnetic yoke is provided w...

AI Technical Summary

Problems solved by technology

[0009]The above-mentioned multi-pole interlocking function is realized by pushing the interlocking part through the moving contact assembly, and the interlocking part pulls the locking parts of other poles. The moving contact assembly mainly Including the moving contact and the bracket, one side of the moving contact is provided with a boss that is linked with other poles, and the other side of the bracket is also provided with a boss that is linked with other poles, and the moving contact and the bracket pass through the shaft Stringed together, due to the manufacturing error and assembly error of the parts, the position consistency of the interlocking boss on the moving contact and the interlocking boss on the bracket is not good, which will affect the consistency of the overall action of the multi-pole circuit breaker

[0010] (5) The connection between the moving contact assembly and the coil of the existing miniature circuit breaker is connected together by spot welding through a flexible connecting wire. The position of the welding point of the moving contact assembly is next to the interlocking boss on the moving contact assembly. If the welding is not good, it will easily affect the interlocking performance of the multi-pole circuit breaker.

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