NC Machining Tool Path Planning Of The Blade Based On Cutting Force Analysis

High-performance and high-reliability aero-engines are the focus and difficulty of China’s aviation manufacturing research.The machining deformation of engine blades is one of the key factors that hinder the further improvement of engine performance.In order to solve the deformation problem of free-form surface parts represented by aero-engine blades in the process of machining,this paper mainly completes the following works:(1)Cutting force modeling of ball-end cutter.the cutting force model of the ball-end cutter is established based on the existing cutting force model.Considering the curvature of the surface and the continuous variation of the cutter axis vector,an algorithm for calculating the thickness of undeformed chip thickness in the cutting force model is proposed to generalize the existing cutting force model from planar parts to free-form parts.According to the analysis of the formation mechanism of the chip geometry,the geometric conditions that the cutting edge segmentation region must satisfy are obtained,complex intersection calculation with high complexity is avoided and the efficiency of cutting force calculation is improved.(2)Cutting force coefficients identification.The machining experiment of the titanium alloy blank is carried out under different cutting parameters,and the cutting force during the process is measured.By establishing the equation relationship between the experimental value and the theoretical value of the average cutting force in different directions,the cutting force coefficients in the cutting force model are solved,and the reliability of the cutting force coefficient recognition result is verified by experimental data,and the complete cutting force model is finally obtained.(3)Tool axis vector planning based on cutting force model.According to the obtained ball-cutter cutting force model,the cutting force data under different cutting parameters are obtained.Based on the obtained data,a neural network model modell is used to map the relationship between cutting parameters and cutting force.At the same time,considering the normal cutting force,the change of the cutter axis vector and the change of the cutting force direction,a neural network model model2 is established to realize the tool axis vector optimization of the input tool position file.(4)Blade NC machining simulation and experiment.The CAM module of UG software is used to generate the NC machining program of titanium alloy blade,the machining simulation with VERICUT software verifies the correctness of the NC program.The tool axis vectors in the partial tool path of the blade finishing stage are optimized,The effectiveness of the tool axis vector planning algorithm proposed in this paper is verified by comparing the deformation of the area whose tool axis vector is optimized with that which is not.