在车辆检修时,为了保证车钩高度,须在心盘下加垫木调整。因下述原因,往往会造成螺栓松动和螺母脱落:(1) 心盘两对面的螺栓组装时未同时用力紧固,一边先紧另一边就难达到预想紧固程度;(2) 因垫木有一定塑性,组装作业时一般又都是起车进行,当时已觉紧固了,当一落车往往发现螺栓松动,尤其投入运用,重车状态时,垫木 In the vehicle overhaul, in order to ensure the height of the coupler, to be placed in the heart under the wood pad adjustment. (1) The bolts on the two opposite sides of the center plate are not tightened with force at the same time, and it is difficult to reach the expected tightening degree on the other side due to the following reasons; (2) There is a certain degree of plasticity, assembly operations are generally starting from the car, then felt tightened, when a car is often found loose bolts, especially put into use, heavy car state, the mat