Abstract:Aimed at the cement leakage phenomenon of the QKX100 buffer of heavy load locomotive on typical line,the longitudinal dynamics calculation of heavy load train was carried out by using longitudinal dynamic simulation software of CARS.Combined with structure principle of cement core,the cause of the trouble of the coupler buffer system was analyzed.It is found that on the continuous steep slope line,the change of slope will cause the sharp change of coupler force.While in the course of circulating braking,there is a great longitudinal impulse in the middle and rear part of the train.In these line conditions,operation of QKX100 is more frequently,the response frequency of the seal components of QKX100 is also greater.So the wear of sealing ring of buffer will increase,and its cement leakage is greater.In order to improve the working state of the buffer,proper locomotive operation,reasonable train formation and more strict buffer production control should be adopted.