Research On Milling Force Modeling And Surface Quality Prediction Of Spiral Surface

As an important component of screw motor,the machining accuracy of screw rotor is related to whether the screw motor can run stably in good condition.With the development of screw machinery manufacturing industry,the machining accuracy of screw rotor is more and more demanding.The machining method of screw rotor is more complicated than traditional milling.In order to improve the machining efficiency,the rotor is usually formed by noninstantaneous core enveloping milling on special CNC machine tools.In this paper,the milling force and the surface machining quality of screw rotors in the process of disc milling cutter machining are studied.The effects of machining parameters on the milling force and surface roughness are analyzed,so as to provide theoretical guidance for further improving the machining efficiency and precision of screw rotors.The specific research contents of this paper are as follows:(1)The milling principle of screw rotor was analyzed.A prediction model of milli ng force on helical surface was established by using the micro-element milling force modeling method.According to the milling process,the dynamic instantaneous cutting thickness model based on the actual milling trajectory was established.(2)The undetermined coefficients in the milling force model were solved by the identification experiment,and the regression model of the shear force coefficient was obtained by regression analysis.On this basis,the influence rule of machining parameters on milling force is obtained.(3)BP neural network algorithm based on improved particle swarm optimization was used to predict the roughness of rotor surface.According to the influence of spindle speed,intermittent feed and machining rate on the roughness of rotor surface,the milling parameters were taken as the training samples of the algorithm,and the surface roughness under the corresponding machining parameters was taken as the target samples of the algorithm.The screw rotor was machined by single factor experiment method,and the surface roughness of the screw rotor was measured.The measured results were imported into the prediction algorithm as sample data for training.The optimized algorithm was compared with the traditional BP neural network algorithm in training test results.(4)On the basis of surface roughness experiments,the machining factors affecting the surface roughness of the rotor were analyzed,the influence law of machining parameters on the surface roughness of the screw rotor was explored,and the correlation between the surface roughness of the screw rotor and the milling force in the machining was analyzed,and the correlation degree of the two was obtained.