Analysis And Experiment Of Chatter Stability Domain For Multiple Factors In The High-speed Vertical Milling

With the rapid development of modern manufacturing,people's processing performance requirements for machine tools are also increasing.The chattering phenomenon in the machining process of the machine greatly affects the machining quality and machining efficiency,and restricts the development of machining technology in China.Achieving high-speed milling and stable machining to avoid chattering is one of the focuses of modern manufacturing research,and is also a necessary condition for China's manufacturing technology to achieve international standards.This paper takes the milling chatter vibration as the research object,based on the processing characteristics of milling machining.Establish the dynamic model of the “tool-workpiece” system in the milling process and analyze the construction method of the milling flutter stability limit map.Milling force coefficient and modal properties of the system is obtained through experimental research.Use the Matlab programming language to plot the chatter stability field related to the milling amount(spindle speed,axial depth of cut).The influence of modal parameters and milling amount on the milling stability limit map was discussed and it provides guidance for the optimization of milling process parameters.The study is as follows:Firstly,based on the milling processing characteristics,a dynamic model was established,and the relationship between dynamic cutting forces and cutting thickness was analyzed.With the regenerative chatter theory,the method of estimating the extreme value of the chatter stability is analyzed.Secondly,based on the mathematical model of the milling force coefficient and milling force,a quadratic polynomial regression method is used to describe the functional relationship between the two.For the selected "tool-workpiece" system,the identification of the milling force coefficient was performed and the milling force coefficient of the system was obtained.The influence of each milling amount on the milling force coefficient was analyzed.Thirdly,after determining that the system modal parameter was the influencing factor of the flutter stability limit map,a hammer test was performed for a specific "tool-workpiece" system,and various modal parameters of the tool and the workpiece were obtained.Using ANSYS simulation software,the modal simulation of the tool with different geometric parameters and workpieces with different geometrical dimensions was performed.The influence of the geometrical structure parameters on the modal parameters was discussed through comparative analysis.Finally,the milling chatter stability map associated with the milling amount(spindle speed,axial depth of cut)was plotted using the Matlab programming language.Through single-factor comparison tests,the effects of modal parameters(natural frequency,modal stiffness,damping ratio)and milling parameters(radial depth of cut)on the flutter stability map were analyzed.According to the stability map,the milling verification test was carried out in the absolutely stable zone,the conditional stability zone and the flutter zone.Judge the occurrence of flutter by surface quality and vibration signals,and verify the accuracy and practicality of the flutter stability map.The research results of this paper provides guidance for the optimization of process parameters in the milling process,which can effectively avoid the occurrence of milling chatter,improve the surface quality of the milled workpieces,and improve the processing efficiency.