T220推土机工作装置液压系统压力低,往往是液压泵或系统主安全阀严重磨损造成的,但是在维修过程中经常容易忽略其他因素也会造成系统压力低。 我单位有台T220推土机出现了松土器提升缓慢、往下不入土的故障。接上压力表测试其工作压力,仅为3.5MPa（正常工作压力为14 MPa）。 按照“先易后难”的原则,依次拆检了工作泵、主安全阀、松土器过载阀和松土器换向操纵阀。拆检过程中,未发现工作泵有异常磨损现象,但发现主安全阀、松土器过载阀及松土器换向操纵阀的阀座和阀芯有轻微磨损现象。为了尽快地找出故障原因,将另一台工作正常的T220推土机的工作泵、主安全阀、松土器过载阀和松土器换向操纵阀换 T220 bulldozers working pressure low hydraulic system, often caused by serious damage to the hydraulic pump or system main safety valve, but often overlooked in the maintenance process can also cause other factors low system pressure. My unit has a Taiwan T220 bulldozers appeared ripper slow increase, down does not enter the fault. Connect the pressure gauge to test its working pressure, only 3.5MPa (normal working pressure of 14 MPa). In accordance with the “easy first” after the dismantling of the working pump, the main safety valve, ripper overload valve and ripper reversing control valve. During the inspection, no abnormal wear of the working pump was found, but slight wear was found in the seat and the valve core of the main safety valve, the ripper overload valve and the ripper reversing control valve. In order to find out the cause of the malfunction as soon as possible, another working T220 bulldozer working pump, main safety valve, ripper overload valve and ripper reversing control valve for