数控机床可用度分析

Analyses of Availability for NC Machine Tools

数控机床的使用过程是在故障与维修交替作用下进行的,假设从系统使用开始已发生N次故障时,则进行预防性维修;而当已发生故障次数小于N时,则仅作事后小修(修复性维修)。根据某型号数控机床1年的25个故障数据,首先采用统计方法对故障数据进行趋势检验,然后通过参数估计与线性相关检验确定数控机床故障过程符合威布尔过程模型。在此基础上,确定其平均可用度模型。

The application of numerical control machine Tools is an alternative process between the effect of failures and maintenances. This paper is based on the assumption that the system will be under predictive maintenance when it fails more than N times after the application , but merely a minor after-failure maintenance （which is also called correction maintenance） will be carried out when the failure times is fewer than N. According to 25 failure data for a certain type of NC machine tools in one year, the statistical method is used firstly to inspect the tendency of the data, then the NC machine failure process is proved to accord with Weibull process model after the estimation of parameters and the examination of the linear correlation. Based on the above work, the model of mean availability is identified.