基于G-R曲线的数控机床故障率分析

Failure Rate Evaluation of CNC Machine Tools Based on G-R Curves Analysis

G-R曲线是地震预报中的一个重要分析手段,主要用来对不同空间和时间窗口的地震活动性进行评估,同时也可以来预测大地震发生的概率。曲线中b值的变化可以反映某个地区的地震活跃程度。将G-R曲线的分析方法对某系列数控车床的故障等级与故障发生频率的关系进行分析,这是在数控机床可靠性分析方法中的一个有益尝试。同时,通过实际的模型分析可以得到:在数控机床可靠性攻关的初期,数控机床故障率高,频发期的b值要比可靠性改进后的故障平稳期小,经过十几年的可靠性攻关,最后b值趋于1.0。

G-R curves are commonly used on seism prediction. It＇s mainly used to estimate seism activities for different spaces and time windows and also to predict the probability of seism occurrence. The variance of b-values can reflect the seism active degree of the area. The G-R curve was used to describe the relationships of failure grades and failure rates of CNC lathes which made an at- tempt on reliability analysis of CNC lathes. The result shows that b-value in frequent failure time is lower than in stable failure time. The b-value is towards 1.0 when the reliability level of CNC lathes was promoted through ten years＇ reliability promotion.