一台卡特D9R推土机已运行13800 h,在作业中突然出现铲刀升降缸不能动作的故障。经过检查发现,发动机工作正常,除铲刀升降缸外,铲刀倾斜缸和松土器液压缸工作均正常。由于各工作装置的液压缸共用一个液压泵,泵压力为26MPa,可以判定液压泵无故障。根据油路分析,故障点应在操作控制阀、快速下降阀和铲刀升降缸这几处。 A Carter D9R bulldozer has been running for 13,800 h, causing a sudden failure of the blade lift cylinder to fail to operate during the job. After inspection found that the engine is working properly, in addition to blade lift cylinder, blade tilt cylinder and ripper hydraulic cylinder work are normal. As the hydraulic cylinder of each working device shares a hydraulic pump, the pressure of the pump is 26MPa, it can be judged that the hydraulic pump has no trouble. According to the oil analysis, the point of failure should be in the operation control valve, rapid drop valve and blade lift cylinder in several places.