加工中心可靠性维修周期的研究

Study on reliability maintenance cycle of the machining center

为了建立加工中心的最佳维修周期与有效度之间的数学模型,以确定最佳维修周期,通过对立式加工中心常见故障的类型及原因分析,建立了平均故障率与规定考察时间之间的关系曲线,分析出了加工中心的平均故障率随着时间的增加而逐渐增大,建立了预防性维修即事前维修与事后维修的可靠性维修间隔时间模型;基于平均故障率函数为递增函数,按有效度为最大时可求出最佳维修周期,并通过实例,运用可靠度函数的数值积分方法,计算出了加工中心的最佳维修周期。研究结果表明,所建立的计算方法为数控机床的最佳维修周期的确定提供了一种有效途径。

In order to establish the mathematical model between the best maintenance periods and the effective degrees on the machining center,the best maintenance period was determined. Through analyzing the causes and types of common fault of the vertical machining center,curve between the average failure rate and a predetermined time was established. For this type of machining center can be repaired,the average failure rate increases gradually over time increased. Time interval model between preventive maintenance and breakdown maintenance was established,this is based on reliability and maintainability. Based on the average failure rate function is an increasing function,the best maintenance periods may be determined when the effective degrees was maximum. And by way of example,the best maintenance period of machining centers was calculated by using numerical integration method of reliability function. The results show that this method of calculation to provide an effective way for determining the best maintenance period CNC machine tools.