Movable static contact structure for plastic-shell circuit breaker

Abstract

The invention discloses a movable static contact structure for a plastic-shell circuit breaker. The back parts of a static contact plastic piece and a static contact are connected with a plastic bracket through a static contact rotating shaft; the plastic bracket is fixedly connected with a connecting bar; a spring is arranged between the back part of the static contact and the plastic bracket; acopper braided wire is connected between the connecting bar and the static contact; the back part of the static contact plastic piece is provided with two fan-shaped bosses which have fan-shaped sections and are bilaterally symmetric to the static contact; first through holes formed in the middles of the two fan-shaped bosses are coaxial with a third through hole formed on the back part of the static contact; the static contact rotating shaft passes through the first through holes and the third through hole, and the two ends of the static contact rotating shaft are connected with the plastic bracket; a first cavity is formed at the middle position of the plastic bracket; the back part of the plastic bracket is provided with a second cavity; the copper braided wire is arranged in the firstcavity; and the spring and the back parts of the static contact plastic piece and the static contact are accommodated in the second cavity. In the breaking process of a circuit breaker, electric arcsare prevented from burning the contact and metal particles produced by an arc chute are prevented from sputtering towards the back part of the static contact, so that the static contact structure is more reliable.

Description

technical field [0001] The invention relates to a molded case circuit breaker, in particular to a movable and static contact structure of the molded case circuit breaker, and belongs to the technical field of low-voltage electrics. Background technique [0002] In the molded case circuit breaker, the static contact is the key component inside the circuit breaker. The static contact structure in the existing molded case circuit breaker is divided into two types: fixed static contact and movable static contact. Among them, when the molded case circuit breaker with fixed static contacts is broken, it only relies on the moving contacts to separate, and the speed of separation between the moving contacts and the static contacts is slow, and the arc cannot be extinguished quickly, resulting in low breaking capacity of the switch. , the circuit breaker is in danger of burning out. The movable and static contact structure can increase the distance between the contacts, so that the ...

AI Technical Summary

Problems solved by technology

The movable and static contacts are generally supported by plastic parts, which are a very important support and protection part for the entire movable and static contact structure. At present, the common problem is the rear protection of the static contacts by the plastic parts of the static contacts If it is not in place, the metal particles produced by the arc burnt contact and the arc extinguishing grid will be sprayed to the rear of the static contact. Once the metal particles adhere to the spring that provides the reset force for the static contact or the static Contact rotation shafts stick together, which affects the performance of the entire circuit breaker

There are two ways to connect the movable and static contacts to the connection bar of the incoming line, one is through the clamping piece, and the other is through the copper braided wire. When the clamping piece is used, the arc root will It will stay at the static contact part, so that the temperature of the static contact is very high, and the clamping place will be deformed and welded, thus affecting the performance of the entire circuit breaker; when copper braided wire is used, the movable and static contact is welded The head is connected with the connection bar of the incoming line. At present, the copper braided wire is exposed outside the bracket, so that the copper braided wire cannot be well insulated and affects the performance of the circuit breaker.

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