Analysis Of Helical Surface Cutting Force

With the continuous development of science and technology,people's demand for high-tech machinery is increasing,and helical machinery is one of them.Helical machinery is widely used in drilling platform,shipbuilding,petrochemical industry and other important fields.In these fields,the type and processing quality of the screw are higher and higher demand.The NC machining of helical surfaces using plate cutter with non-instantaneous section envelope method,which is the international advanced screw machining method.However,in the process of screw machining,the force of each cutting point of the spiral curved surface has not been accurately analyzed,and the cutting speed is artificially adjusted according to the cutting condition of the workpiece,so as to alleviate the damage of the cutting tool.Therefore,the analysis of helical surface cutting force has important theoretical significance and practical production.This dissertation is based on the non-instantaneous section envelope method of plate milling cutter.According to the geometrical relation of the tool and workpiece in relative motion process,the mathematical model of the space meshing trajectory of the tool workpiece and the shape of the plate milling cutter is used,and the cutting characteristics of plate milling cutter,the cutting area is analyzed,and the mathematical formula of the instantaneous cutting force suitable for this particular machining method is deduced.Based on the finite element analysis of metal cutting force,the stress cloud diagram of the spiral curved surface in the cutting process is simulated.The variation law and distribution of the cutting force are obtained by analyzing the stress cloud diagram.This dissertation also aims at two different types of cutter tips for plate milling cutters,that is,the similarities and differences of cutting forces between circular and sharp cutters in cutting process are compared and analyzed,and the effects of cutting speed and depth on cutting forces are analyzed.With the maximum surface cutting rate and the minimum workpiece surface roughness as the optimization objective function,the cutting speed and depth are optimized,which provides a theoretical method for practical production.Through the analysis of the above method,this dissertation conclude that the cutting force is larger than the rear cutter surface in the process of cutting helical surface with platemilling cutter,the distribution of the cutting force at the tip of the cutter is the largest,and cutting force is the tendency of stable change after the rapid increase.When other conditions are the same,the cutting force of the circular knife is greater than the sharp knife,and the cutting force of circular knife is more stable when the cutting is in steady state.The results of this study can be used to predict the cutting force before the screw workpiece is processed,through the change of cutting speed,the efficiency and precision of screw machining are improved,and the smoothness of screw surface is improved.