机车用单元制动器悬挂连杆的断裂问题分析

Analysis of Fracture Problem of Suspended Connecting Rod in Locomotive Unit Brake

保证准确有效的制动是列车安全运行的重要保障,踏面单元制动器中闸瓦过度磨损、不缓解及零件损坏等故障成为事故发生的巨大隐患.针对机车用单元制动器的悬挂连杆断裂问题,建立车轮-闸瓦-闸瓦托-悬挂连杆整体三维有限元模型和悬挂连杆三维有限元模型,分别对悬挂连杆进行受力分析和强度分析.通过计算结果和现场情况的对比分析,得出结论:悬挂连杆在制动作业时,同时承受轴向的拉压作用力以及车轮与闸瓦摩擦所产生的横向力;由于横向力的存在,使悬挂连杆在制动工况下的应力值有明显增大;悬挂连杆的圆角及中部位置属于应力集中区域且最大应力点位于圆角处,这是悬挂连杆断裂的主要原因.

It is an important guarantee for the safe operation of the train to ensure the accurate and effective braking. The failures of the unit brake, such as brake-shoe overwear, not ease and parts damaged etc, have become a huge hidden trouble resulting accidents. Aiming at the fracture problems of suspended connecting rod in locomotive unit brake, the three-dimensional finite element model of wheel/ brake-shoe/brake-shoe-holder/suspended-connecting-rod and the three-dimensional finite element model of the suspended connecting rod have been set up to canT out the force and strength analysis of the suspended connecting rod. Through comparative analysis of calculation results and field situation, the conclusions have been drawn. The suspended connecting rod is subjected to the axial force as well as the lateral force produced by the friction between wheel and brake-shoe during the braking operation. Because of the existence of the lateral force, the stress of the suspended connecting rod under the braking condition is obviously increased. The stress concentration area is at the chamfering and the middle position of the suspended connecting rod. And the maximum stress is situated in the chanffering, which is the major cause of the suspended connecting rod fracture.