unbraced excavation

It is discovered that the two kinds of lack of cutting force and three reason of action slow.

应用液压传动的基本原理,结合日立EX系列挖掘机机电液一体化的工作特点,对EX系列挖掘机两典型故障(挖掘无力与动作慢)的测试、诊断方法做了系统分析与介绍。