我单位购买的一台120推土机,使用时间不长就出现了异常现象,主要是:在发动机大油门情况下,铲刀提升力不足,上升缓慢;操纵阀手柄在铲刀上升过程中,只要手一松,铲刀就自动迅速下降,即铲刀不能任意定位。对此故障我们按下述几个方面进行了检查和分析: 1.怀疑油液中有杂质,致使有的阀关闭不严而漏油,导致此故障。为此,我们将液压油换成了航空液压油,但试验结果表明上升力不足的故障不但没有排除,而且不定位的现象 The 120 bulldozers purchased by our company have not been used for a long time. Anomalies have occurred. The main reason is that in the case of a large throttle of the engine, the lifting force of the blade is insufficient, and the rise is slow; the handle of the valve is only required to be raised during the rising of the blade. A loose, the blade will automatically drop quickly, that is, the blade can not be positioned. We conducted inspections and analysis on this fault in the following aspects: 1. Suspected that there were impurities in the oil, causing some valves to close loosely and leaking oil, resulting in this failure. For this purpose, we replaced the hydraulic oil with aviation hydraulic oil, but the test results show that the failure of insufficient lifting force has not been ruled out and is not positioned.