Optimization Of Computerized Numerical Control Machining Process Parameters Of Small Impeller Based On Genetic Algorithm

As an important component that is widely used in the mechanical equipment industry,the impeller plays an irreplaceable role in aviation,aerospace,electric power,metallurgy,petrochemical,and other fields.It not only reflects the development of high-speed mechanical manufacturing technology in our country,but also has an extremely important scientific research significance,industrial practical value,and social and economic value.In the CNC(Computerized Numerical Control)machining process of small impeller,process parameters are an important factor affecting the quality of the machined surface.At present,the process parameters of the small impeller are mainly adjusted by the workers according to the processing experience,and the surface quality of the small impeller cannot be guaranteed to be optimized.Therefore,how to select process parameters scientifically and efficiently is the key to high-quality small impellers machining.The outward opening integral small impeller was selected as the key research object,and the main evaluation indicators of the surface quality of the experiment were set as the surface roughness and residual stress.The finite element simulation technology was used to analyze that how can process can parameters affect the residual stress and outer surface roughness of the small impeller.After getting the results,the genetic algorithm was used to optimize it to get the optimal combination of process parameters.The numerical control machining test of the small impeller was carried out to verify the feasibility and accuracy of the process parameter optimization.Specific research contents include:(1)By analyzing the structural characteristics and processing difficulties of the small impeller,this study designs the processing path of the small impeller at different stages was designed and a reasonable trajectory planning was carried out.(2)In this study,four important processing parameters axial cutting depth,radial cutting depth,spindle speed and feed per tooth.were selected to conduct orthogonal milling experiments on workpieces.By using finite element simulation software,it can be determined that how the milling force changes when each set of process parameters changes.Then,the data of simulated milling force of each group of machining parameters were analyzed by multi-factor analysis function.Finally,based on the above analysis results,we can obtain the influence of process parameters on the milling force can be obtained,a prediction model was established based on this to verify the model accuracy.(3)Based on the orthogonal test,the surface roughness of the small impeller blades under different process parameters was measured.By parametric fitting we can obtain the empirical formula of surface roughness can be obtained.Then finite element simulation technology was used to build a simplified model of the single blade in the milling process and the residual stress value in blade milling process under different process parameters was simulated by orthogonal test.Finally,the method of parameter fitting was used again to obtain the residual stress empirical formula.(4)According to the optimization principle,taking the minimization of surface roughness and the minimization of residual stress as the optimization goals,we can obtain the optimal combination of process parameters can be obtained by constructing a multi-objective optimization mode of small impeller machining process parameters and using genetic algorithm to optimize the process parameters.On this basis,the numerical control machining experiment of the small impeller was carried out to verify that the optimized process parameters are greatly improved,the surface roughness is reduced by 34.2%,and the residual stress is reduced by28.6%,and at the same time proved the feasibility of the optimization of the process parameters is proved.To sum up,the research in this paper is of great significance to improve the processing level of the small impeller,and provides a certain reference value for the high-speed milling and other precision CNC machining technologies.