数控磨床维修时间分布及维修性评估研究

Study on the Repair Time Distribution and Maintainability Evaluation of CNC Grinding Machine

数控磨床作为现代制造装备中不可缺少的精加工装备之一,其可靠性、维修性等方面的研究就显的十分有必要。根据某型号数控磨床在使用厂家具体的使用情况,利用现场得到的维修数据进行分析,绘制出了其维修时间的分布函数以及分布概率密度函数的散点图,并使用极大似然法进行参数估计,采用相关系数法对曲线拟合优度进行求解,进而确定维修数据的分布类型属于对数正态分布;得到维修时间的维修度函数、概率密度函数以及维修率函数的表达公式;由此对数控磨床的维修性方面的指标进行计算,获得平均维修时间,最大维修时间以及维修时间中值。为后续进行数控磨床在制定维修方针以及确定维修时间间隔上提供相应的依据,取得的相应成果已运用于可用性提升工程。

CNC grinding machine is one of indispeusable equipment in modern manufacturing equipment, it is very necessary to research its reliability, maintenance and other aspects. According to the condition of service about the certain type of CNC grinding machine in the factory, analyzing the maintenance data obtained from the field and protracting the scatter diagrams of the repair time distribution funetion and repair time distribution density function. Using the method of maximum likelihood to estimate pacameters, the correlation coefficient method is used to solve the optimal degree of curve fitting, and to determine the distribution of the type of maintenance data is logarithmic normal distribution. The formula of repair time maintenance function, probability density funetion and maintenance rate function is obtained. It can calculate the maintainability index of the CNC grinding machine to obtain the results of mean time to repair, maximum repair time and median repair time. It will provide the appropriate basis for making the maintenance policy and determining maintenance intervals for the follow-up work, and the corresponding results have been applied to the usability improvement projects.