Research On Quality Control Technology For Manufacturing Process Of CNC Machine Tools

As the basic support equipment of manufacturing industry,the Computer Numerical Control(CNC)machine tools play an important role in the development of manufacturing industry and other fields.The reliability level of CNC machine determines the development level of a country's manufacturing industry,and also reflects the industry status of a country in the field.Therefore,the research and control of the reliability of CNC machine tools is the internal driving force to promote the continuous development and prosperity of the national manufacturing industry.CNC machine manufacturing process is the key link to form its inherent reliability.The quality analysis and control of manufacturing process can significantly improve the CNC reliability level.Early failure of machine tools is one of the most important factors that affect the reliability of machine tools.Therefore,eliminating early faults can effectively improve the reliability of CNC machine tools in user's hands.This paper has certain practical significance,which analyses and control the reliability of CNC machine tools from these two aspects.The specific research contents are as follows.1)Processing quality control of CNC machine tools based on the quality of its own parts manufacturing.At first,the concept of the key parts of the CNC machine tool is explained,and the evaluation method and evaluation basis of the key parts are putted forward.Then through the analysis of the key process definition,the evaluation index of the key process is determined,and the weight of each evaluation index is calculated by Entropy Method.Next the attribute values and entropy weights of each index are applied to the grey relational projection method,and the projection values of each process sequence in ideal sequence are solved.According to the projection,the importance degree of each process is determined,and the key process can be selected according to the "20/80" principle.Finally,the comprehensive quality control measures are made for the machining process of NC machine tool parts from the point of view of 5M1 E.2)From the angle of machine accuracy,stability,reliability,cost and operation simplicity,a comprehensive assembly sequence evaluation index system is worked out.Then rough set theory is applied to reduce the evaluation index,effectively remove redundant items in the index system,and retain the core index.After that,the TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)method is used to sort the assembly sequence,and the best assembly plan in the existing assembly sequence is selected from it.This method can reduce the workload of the evaluation process while ensuring the effectiveness of the evaluation,and it also has high practicability.3)The Early fault excitation test was carried out on a manufacturing center.The test contents include: accelerating non cutting simulation test and continuous cutting test.Before the test,making a detailed plan for the test.In the test,the time of fault occurrence,the failure phenomenon,the maintenance method and the repair time was recorded in detail,and the ambient temperature and the performance parameters of the auxiliary system was monitored in the test process in real time,the external conditions in the working process of the machine was ensured.After the test,analyzing the type,the cause and the maintenance measures of the failure in the test.Finally,a failure analysis report for archiving was formed.