某特种车托架下放超时问题分析与解决

Analysis and Solution on the Time-out of A Special Vehicle Bracket's Lower-leveling

针对某型特种车高油温工况下托架下放超时现象,通过对故障原因的分析,初步定位在平衡阀控制活塞桥路上的旁路孔在高温下分压效果增强,系统开启压力不足,导致平衡阀开度不够,通过流量不足。利用AMESim仿真软件,搭建平衡阀模型,并通过分析建立等效的简化模型,仿真控制活塞桥路上的旁路孔在高温下对控制压力的影响,分析出旁路孔高温下对控制压力的降压效果。封堵旁路孔后,对平衡阀进行高温试验,平衡阀开启压力基本不受温度影响,在实车上验证,高温工况下托架下放时间基本保持不变,且下放稳定性无明显变化。

On analysis of the time-out of a special vehicle bracket＇s lower-leveling, the cause is found out. It＇s because that the pressure-depressing of by-way hole on the piston of counterbalance-valve reinforced which causes the flow is not enough. The simulation model of counterbalance valve is built by using AMESim. And the equivalent simplified model is built on analysis. The effect of by-way hole on reducing controlling pressure is found out by simulating the influence of by-way hole on the piston of counterbalance-valve under high temperature. High temperature experiment is implemented after plugging by-way hole and the results show that the unlocking pressure is not affected. Validation on the real vehicle, the time keeps stable basically on high temperature and it acts steady.