The Researchment Of Ball-end Milling Force Modeling And Semulation

Ball milling cutters are widely used in the finishing of complex curved parts such as eyeglass lenses,engine impeller blades,molds and aircraft wings due to their strong adaptability.However,the milling force of the ball-end milling cutter has a significant effect on the processing quality and is a key factor affecting the processing stability and processing efficiency.Therefore,it is very important to model the milling force of the ball-end milling.Based on the powerful computing power of modern computers,the milling force of the ball-end milling can be quickly simulated,the influence of different tool parameters and process parameters on the milling force can be accurately predicted.The optimization of machining parameters and tool parameters with the goal of longer tool life,more stable machining process and smaller cutting force has important guiding significance for the industrial upgrading and optimization of manufacturing industry.This paper focuses on the modeling and simulation of the milling force of the ball-end milling.Firstly,the factors such as tool parameters,feed speed,eccentricity of tool axis and inclination of tool axis in milling process are analyzed.The kinematic model of point of cutter tooth is accomplished by establishing datum coordinate system and using the principle of homogeneous coordinate matrix transformation,and the coordinates of any cutting point on any cutter tooth in workpiece coordinate system at any time are obtained.Then,a cutter-workpiece contact area identification method and the calculation method of instantaneous undeformed chip thickness based on logic array are proposed.On this basis,the milling force modeling and Simulation of ball end milling are completed by combining micro element method and Z-map method.In order to verify the precision of the built milling force predictive model,a cutting verification experiment was designed.Comparing the simulation results and the experimental results,the following conclusions are obtained:the milling force prediction model can accurately predict the milling force,and the prediction accuracy is improved after the eccentricity of tool axis is introduced.The milling force prediction model successfully introduced the eccentricity of the cutter axis.Based on the milling force prediction model,the simulation and analysis of the effect of cutter parameters and machining parameters on the milling force was carried out.The influence of cutter helix angle,cutter radius,cutting depth,feed per tooth and line distance on the milling force was studied and get the selection principle of tool parameters and machining parametersFinally,the research contents of the thesis are summarized and prospected.