Research On Optimization Method Of Milling Parameters Based On Milling Force Modeling

With the rapid development of modern manufacturing industry,ship,aviation and other fields also put forward higher requirements for the processing of key parts.Especially the processing of high-precision complex surface parts is particularly important.Among many processing methods,milling has irreplaceable advantages because it can process cavity and curved surface.How to improve the stability during milling is an important indicator to improve processing.Helical end milling cutter and ball end milling cutter which are commonly used in milling are taken as research objects in this paper.In this paper,the modeling of cutting force in milling process are deeply studied.The model of helical end milling cutter cutting force and the model of ball end milling cutter bending moment are constructed.In order to improve the processing efficiency and quality,the processing parameters of helix end milling cutter and the posture ball cutter are optimized according to the actual processing conditions.The main research contents are as follows:1.In this paper,the mechanism of metal cutting is analyzed based the domestic and international research results.The changing process of two-dimensional right-angle cutting and the factors causing the variation of cutting force are studied.Then a series of coordinate transformations are used to transform the three-dimensional oblique cutting into the equivalent two-dimensional right-cutting.The analysis of oblique cutting model lays a foundation for the complex milling analysis in the future.2.Based on the cutting force model of helical end milling cutter,the influence of milling depth on cutting force in the process of milling is studied.Through cutting force simulation and experiment,it is found that the influence of the axial milling depth on the fluctuation of cutting force is significant.By analyzing the cutting force in time domain and frequency domain,it can be found that choosing the appropriate axial milling depth can reduce the fluctuation of cutting force and improve the processing efficiency withoutreducing the processing quality.3.Based on the characteristics of five-axis machining,the lead angle and the tilt angle are established to describe the machining posture of ball cutter.The maximum bending moment of ball end milling cutter with different postures is studied through theoretical analysis of cutting force of ball end milling cutter.And the validity of the model is verified by experiments.The experimental results show that the machining geometry accuracy can be improved by selecting a reasonable machining attitude.4.The problem of unstable cutting near the point of ball cutter in the machining are studied.The scaling effect caused by the low cutting speed leads to the instability of cutting force.The unstable cutting force speed points are decided by simulation of right angle cutting model.The experimental results show that the machining quality is better when the lead angle is positive and the minimum cutting speed in the contact area is greater than 50m/min.