The Study Of CNC Machine Tool’s Assembly Reliability Based On Assembly Complexity

The computer numerical control machine tools are the important manufacturers ofother equipment in equipment manufacturing industry and their reliability level hasbecome the bottleneck which restricts the industry development. The reliability shouldbe integrated into the implementation process of the entire work, while the current studywork only focuses on the reliability of the design and use. Assembly is an important partof CNC machine tool manufacturing. Assembly not only takes a long time, costs more,but also has a huge impact on the final performance of the machine. Building thecomplexity of the model to assembly based on the assembly process, using fuzzyBayesian theory to analyze the reliability of the assembly, extracting critical assemblystep, and on this basis, focusing on the key step to control the assembly, this work willbe a new ideas for the reliability of control.Based on the support of National Natural Science Foundation, making thedomestic machining center for the study, the reliability of CNC turret assembly processwas studied. The main contents are as follows:â‘ Building the complexity of the model to assembly based on the assemblyprocess, integrating assembly drawings and assembly process in the file-basedinformation, combining with the actual assembly of the failure statistics, building theassembly process for the manual assembly of analytical methods, analyzing thecomplexity of the operation of the assembly process, establishes static and dynamiccomplexity of the model generalized entropy theory. Build relationships assemblycomplexity and assembly reliability, and use assembly complexity to assess thereliability of the assembly process, so that the effectiveness of the assembly process hasbeen evaluated.â‘¡A variety of assembly process failed state of assembly components wasdescribed with fuzzy numbers, considering the impact of different fault state of thesystem; the fuzzy assembly failure rate of the assembly process of assemblingcomponents of the assembly was described by fuzzy subset, to reduce the failure rate toobtain precise assembly unit assembly difficulty values; failure logical connectionsbetween components assembly was described by Bayesian networks conditionalprobability table, to solve the inter-linkages uncertainty. By combining the reliabilityanalysis of CNC turret assembly instance, describes the proposed method in terms of assembly reliability, criticality analysis and fault diagnosis system of assemblyapplications.â‘¢Combining assembly complexity and importance to build critical assembly stepextraction model with CNC turret of CNC machine tools for the study, building thecomplexity model to assembly based on the assembly process, extracting key assemblystep, combining with the reliability of the control measures in the assembly theprinciples and the reliability of the drive to develop clean assembly principles,developed control measures of reliability critical assembly step, and verified theeffectiveness of the method.