Research On Reliability Analysis And Control Technology Of CNC Machine

Machine tools are treated as equipment manufacturing machine tool machine,which directly affects the reliability of the development level of the equipment manufacturing industry.CNC lathes are treated as an important series of machine tools.After years of efforts,the reliability of the domestic low-end CNC lathes l has made great progress.But there is a big gap of reliability between the domestic high-end CNC lathes and foreign advanced level machine tools,which greatly affected the product market competitiveness.There are many characters of domestic CNC lathes failure mode which have many types and complex causes of failure.It cause great difficulty to the research in CNC lathes.Based on the research of a national special science and technology project,this paper analyzes the relationship between the failure mode and the cause of the fault of a series of domestic CNC lathes by studying the failure mode of the CNC machine,and makes the feasible reliability control measures in order to provide a guarantee of continuous improvement for the reliability of the machine.This paper is of great significance and can provide technical support for the reliability improvement of domestic CNC machine.The main contents of this paper are as follows:? The reliability analysis and control system of CNC lathes is proposed.The failure mode of the CNC lathes are counted as the unit system,and the failure mode of each subsystem and the probability of the failure mode of the subsystem are counted by analyzing and dividing structure of a series of domestic CNC lathes.The subsystem with higher probability of failure is used as typical subsystems,and the detailed FMECA analysis is carried out,in order to provide reference for other subsystems.? The establishment of the RPN evaluation model based on the evidence theory analyzes the failure mode of the CNC lathes and find out the major failure mode which has the important influence on the reliability of the CNC lathes.This paper introduces the theory of fault tree analysis and the theory of set pair analysis to clarity the relationship between the faults and the fault sources.The establishment of set-pair fault tree analyzes the main faults of CNC lathes,and obtains the fault sources which mainly affect the main faults.So we can clear the main effects of the reliability of CNC lathes.Taking a series of domestic CNC lathes as an example.? Aiming at the main faults and main fault sources of the CNC lathes,the corresponding reliability control measures are established.Based on the theory of polychromatic sets,the correlation matrix and the boolean expression between the main faults and the main fault sources of CNC lathes and between the main faults sources and control measures are established.And the TPS control table of the main faults-the main faults sources and the TPS control table of the main faults sources-control measures are established.Based on AHP,the purchasing supplier reliability evaluation and selection model is established in order to ensure the reliability of purchased parts.