数控机床液压系统故障溯源及分析*

以提高机床液压系统可靠性为目的,分析了液压传动的特点,并对常见的故障现象进行了整理,归纳出了振动异响、压力不足及波动大、流量不稳定、液压元器件损坏四种典型的故障模式。以某磨齿机为例,采用FTA(故障树分析)方法,对四种故障模式进行了故障原因溯源,找出了造成系统故障的根本原因。以压力故障为例进行了定量分析,对每个底事件的概率重要度和相对概率重要度进行了计算,并阐述了重要度分析在可靠性改进和控制过程中的重要作用。

Fault trace and analysis of hydraulic system attached to CNC machine tools

This paper analysed the features of hydraulic transmission in order to improve the reliability of the hydraulic system attached to machine tools.Meanwhile,it summed up four typical fault modes including vibration and noise,insufficient pressure and pressure fluctuations,instability of flow,failure of hydraulic component after gathering the common fault phenomena.Taking one gear grinding machine for example and using FTA to search the root reasons of four typical fault modes and get the results finally.It completed quantitative analysis based on pressure fault,in the same time,the probability importance and relative probability importance of every root reason were be calculated which was used to elaborate the important role of importance analysis in improvement and control procedure of reliability.