Research On Evolutionary Design Of Key Components Of CNC System Based On Life Cycle Fault Analysis

CNC system is the "brain" of modern machine tools.Because it can control different movement states of machine tools,it plays an important role in the whole product.With the development of China’s industry and the strategic planning requirements of "made in China 2025",the machine tool industry has higher and higher requirements for CNC system.However,the cognition of the whole life cycle of CNC system in China is relatively poor,which leads to the problems of unclear identification of key components and unclear optimization effect.This has become a stumbling block for China’s CNC system to move towards the international high-end market,so the upgrading of domestic CNC system cannot be delayed.Based on the national science and technology major project "domestic CNC system brain changing project for manufacturing typical parts of aeroengine"(Project No.: 2017zx04011013)of high-end CNC machine tools and basic manufacturing equipment,this paper puts forward a new method based on the whole life cycle under the guidance of relevant evolution rules of TRIZ theory,aiming at the CNC system of gnc60 model of a domestic enterprise The evolutionary design method of obstacle data analysis.Firstly,the weak subsystem of the CNC system is determined by the analysis method of the whole life cycle;secondly,the key components of the weak subsystem of the CNC system are obtained based on the method of decision and laboratory and the method of dematel-topsis;finally,the heat dissipation design of the key components is carried out by using the method of genetic algorithm and numerical simulation.The research method is also applicable to systems with more fault data,longer life cycle and unclear key components.The main contents of this paper include the following aspects:(1)Basic research on TRIZ theory.Firstly,according to the relevant literature,the concept of the whole life cycle evolutionary design of CNC system is defined,and the application scope of the evolutionary rules in TRIZ theory is determined.Secondly,the evolutionary rules suitable for the whole life cycle evolutionary design of CNC system are selected based on the actual use of CNC system.Finally,these rules are applied to guide the research of the whole life cycle evolutionary design of CNC system Research work.(2)Life cycle fault analysis of CNC system.Based on the "micro level evolution rule",the fault data of CNC system in the whole life cycle are analyzed in two levels.In the first layer,considering the whole life cycle of CNC system,using dynamic importance measurement model and frequency statistics,the servo drive system is a weak subsystem;in the second layer,starting from the structural level of servo drive system,combining with the hardware situation of servo drive system,using the idea of clustering,six failure modes and corresponding important components are determined by traversal algorithm(general power supply,linear motor,servo drive module,etc.)so as to narrow the analysis range of CNC system.(3)Identification of key components of servo drive system.According to "S-curve rule",an evaluation method based on dematel-topsis is proposed.Firstly,the relationship between RPN of FMECA(failure mode,influence degree and hazard analysis)and RPN of process FMECA is used as input data of DEMATEL to get the weight value required by TOPSIS.Then,the improved TOPSIS distance formula is applied to sort the failure modes.As the failure mode corresponds to the failure component,the servo drive module is identified as the key component,and the high temperature is the main reason for the failure of the servo drive module through the test.(4)Thermal evolution design of servo drive module.According to the object field model in "the law of contradiction generation and overcoming",the thermal evolution design of servo drive module is guided.Firstly,the physical model of heat dissipation is established,and the main parameters of heat dissipation design are the size parameters of the servo drive module case and the size parameters of the radiator Icepak numerical simulation optimizes the distance between the fan and the radiator and the deflection angle of the fan,and finally realizes the effect of 21.24% reduction of the overall temperature of the servo drive module.