Optimization Of Drill Structure Parameters For High Strength Steel Processing

At present,due to its advantages of high temperature resistance,corrosion resistance,abrasion resistance and ultra-high strength,the high-strength steel materials are widely used in various industrial fields such as aerospace,chemical industry and weaponry.However,there are also problems in cutting machining which make its processing efficiency lower,processing costs larger.In production practice,drilling is a very common method of high-strength steel drilling.Therefore,it is necessary to study the influence of the drilling performance of high-strength steel for drilling to optimize the structural parameters of the drill,which is of great significance to improve the drilling efficiency of high-strength steel.In this paper,by analyzing the basic characteristics of the solid carbide drill,and theoretical analysis of the impact of the geometric parameters on the drilling performance and the importance of reasonable selection,combined with ANCA five-axis CNC grinding machine grinding principle,SolidWorks software be used to complete the 3D solid carbide drill modeling.In the actual metal drilling process,cutting force,chip morphology and tool wear are the main indexes that reflect the cutting process,especially the cutting force(axial force and torque),which is more representative.Therefore,based on the finite element theory,the geometrical parameters(helix angle,chisel angle and vertex angle)of the solid carbide drill are rationally distributed by the orthogonal experiment method.The finite element software Deform-3D was used to simulate the process of 20 CrNiMo high-strength steel drilling by solid carbide drill.And set the key steps in the process of simulation,including the setting of process parameters,the introduction of bit model,the definition of model size and material properties,the definition of boundary conditions and meshing,the setting of simulation control and the simulation operation process and so on.The simulation results obtained by the axial force and torque diagram were analyzed and the simulation of the axial force and torque value,linear regression analysis to determine the impact the performance of drilling bit the best level combination of geometric structure,so as to complete the solid carbide drill structure optimization.The optimized solid carbide drill is analyzed by modal analysis and harmonic response analysis,the fifth-order natural frequency and mode of the drill,and the displacement amplitude responses along X,Y and Z directions under different external stimuli are obtained.The first and second modes are easy to cause resonance,and the excitation frequency should be far less than the first natural frequency so as to reduce the drilling vibration.At last,the un-optimized drill and the optimized drill are processed by CNC grinding machine to verify the experiment.The feasibility and rationality of the optimized drill are verified from the aspects of axial force,torque,vibration,drill wear level and chip shape.The research work of this project solves the difficult problem of drilling high strength steel,shortens the design cycle of the solid carbide drill,improves the drilling efficiency,at the same time,it also provides a certain method of reference for the processing of other types of difficult-to-machine materials and other types of tools.