基于可靠性的断路器操动机构公差链的研究与分析

Study and Analysis on Tolerance Chain of Operating Mechanism for Circuit Breaker Based on Reliability

针对断路器操动机构零件公差积累后造成脱扣力过大和扣接量过大或过小,影响断路器动作可靠性问题。通过对机构的脱扣部分传动链进行受力分析找出影响合闸可靠性的几个较关键的零部件,分析扣接量对合闸脱扣的影响和画出合闸脱扣系统扣接量的尺寸链。并对储能保持状态时的机构扣接量进行公差链计算,发现现有产品的公差配合不满足完全互换情况下的扣接量的取值范围,通过公差链的仿真分析,找出影响合闸脱扣力及扣接量大小的关键零部件和尺寸,得到影响脱扣力和扣接量的敏感度和贡献度的关键零部件及其尺寸。对现有的设计公差进行优化设计,实现了产品的公差链满足完全互换条件下的技术参数。最终解决了零件公差影响断路器可靠合闸的问题。

In view of the problem that operation reliability of the circuit breaker is affected due to excessive tripping force and excessive or small amount of buckling after the accumulation of tolerances of the parts of operating mechanism for the circuit breaker several key parts affecting closing reliability are found out through the force analysis of the transmission chain of the tripping part of the mechanism.The influence of the amount of buckling on the closing and tripping is analyzed and the dimensional chain of the buckling of the closing and tripping system is drawn.The tolerance chain calculation of the buckling amount of the mechanism in the charge holding condition is performed,finding that the tolerance fit of the existing product does not meet the value range of the buckling amount under the condition of complete interchange.Through the simulation analysis of the tolerance chain,the key parts and dimensions affecting the closing and tripping force and the amount of buckling are found out and the key parts and their dimensions affecting the sensitivity and contribution of the tripping force and the amount of buckling are obtained.The optimization design of the existing design tolerances is performed and the tolerance chain of the product fully meeting the technical parameters under the condition of complete interchange is achieved.Finally,the problem of parts tolerance affecting the reliable closing operation of the circuit breaker is solved.