Stability Analysis And Process Parameter Optimization Of Variable Speed Milling

As an important processing method,the main goal of milling is to improve the machining quality and efficiency of workpiece,and the realization of this goal is closely related to how to choose cutting parameters,and the selection of larger cutting parameters can improve machining efficiency.However,it may cause chatter and affect the surface quality of the workpiece.In order to solve the above problems,this paper aims at the method of suppressing flutter by modulating spindle speed,deeply explores its mechanism and introduces the influence of dynamic cutting force coefficient,and establishes the prediction process of variable speed milling stability.At the same time,in order to select the process parameters reasonably,a multi-objective optimization method of variable speed milling process parameters is proposed.The main contents of this paper include:(1)Based on a two-degree-of-freedom dynamic model,a variable speed milling dynamic model was established,in which the cutting force coefficient was taken as the variable,and the regression equation was used to represent it.A prediction model for the stability of variable speed milling suitable for variable cutting force coefficient was formed based on the model and the fully discrete method.In addition,based on the above model,the influence of various process parameters on the milling stability of variable speed milling was further investigated.(2)An experiment of cutting force coefficient identification was designed and conducted,the cutting force coefficient was obtained and its regression model was fitted,and the influence of cutting amount was analyzed.Hammering experiments were carried out on the milling system,the dynamic parameters of the system were identified,and the influence of modal parameters on stability was discussed.The stability prediction was carried out according to the obtained parameters,and cutting experiments were conducted with suitable parameters to verify the accuracy of the stability prediction method.(3)Genetic algorithm was used to optimize the process parameters of variable speed milling process,with cutting efficiency and cutting force as the optimization targets,and a criterion of stability was added to the algorithm as a constraint.According to the optimization results,it was explained how to select the process parameters and the stability of the selected process parameters was verified.