| Since the reform and opening up forty years ago,with the continuous development of society,the continuous improvement of the national level of science and technology,as well as the continuous update and iteration of micro-electronic technology,integrated circuit chips are gradually developing towards the direction of super sub-micron.All these have brought great challenges and difficulties to SMT industry.In SMT production,the most important,critical and complex equipment is the SMT machine.Nowadays,the laminating machine has developed from the early low speed mechanical laminating machine to the high speed optical centering laminating machine,and to the direction of multi-function,flexible connection,modularization,lightweight and so on.Among them,because the motion characteristic of the SMT machine is the reciprocating motion of high speed,this has a high demand for the mechanical properties of the key position structure,and the structure is also prone to fatigue failure.In this thesis,finite element theory is used as the analysis basis,using ANSYS Workbench software to establish finite element analysis model,the key components of the lamination machine are analyzed and studied,and optimized on the basis of ensuring its working performance.Finally,the reliability analysis of the optimized model verifies the rationality and reliability of the optimized model.The main research contents are as follows:(1)The modal analysis of the key components of the SMT machine is carried out.Modal analysis is carried out on the frame,beam and the connecting plate of the mounting head of the SMT machine,and the natural frequency and vibration mode of these parts are obtained,which ensures that the natural frequency and excitation frequency of these main parts are in a safe range under the working state,and resonance phenomenon will not occur.(2)Through the static analysis module,the maximum equivalent stress value and maximum total deformation value of the parts in the working state are obtained,and their strength and stiffness are verified.NCode Design Life fatigue analysis software was used to analyze the fatigue life of the mounting head connecting plate.It is found that the design of this part is conservative and there is some space for optimization.(3)the design module of ANSYS Workbench,parameter sensitivity analysis was carried out on the parts,screen quality and life of the structure,the equivalent stress,deformation and natural frequency as a greater influence on the output values of a set of parameters,such as design variables,and then determine the optimal range of these variables,the optimization design of parts of the input parameters.Using the response surface analysis under the module,the above parameters were taken as the design variables of the optimization,and the input to output response surface model was established by sampling and fitting with certain methods.The fatigue life and quality of parts were determined as the main optimization objectives,and the optimal design point was finally obtained.The optimization results show that the quality of parts is reduced by 37.82% compared with before optimization,on the basis of ensuring the required performance of parts and over 1e+10 fatigue cycles through response surface optimization.(4)Six Sigma module was used for reliability analysis of the optimized model,and the maximum equivalent stress,maximum deformation and fatigue life reliability of the optimized model were obtained.The results show that the optimized model has good safety and reliability.In this thesis,the parts are optimized on the basis of ensuring the performance of all aspects of the structure,which not only reduces the quality of the parts,but also ensures the performance and fatigue characteristics.At the same time,the research results also provide a new idea for the manufacturing and related analysis of parts in the future,which has certain guiding value and important application significance. |
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