Interference Analysis And Tool Optimization Of Cylindric Thread Milling With Non-symmetric Thread Profiles

Thread connection,as the common connection mode,which is widely used in manufacturing industry.Among them,the non-symmetric thread has the advantages and merits of high transmission efficiency,nice mechanical property and anti-looseness.It can be used not only in transmission devices,but also in the occasion of fastening connection.Consequently,the quality of thread processing directly affects the reliability and security of mechanical equipment.Thread milling has fascinated an increasing number of attention because of its high efficiency,good versatility and low processing cost.Nevertheless,for the reason that the envelope surface of the thread milling cutter can not completely matches the thread contour,interference and unreasonable choice of tool rake angle in the process of thread milling leads to greater fluctuation of cutting force,resulting in processing instability,and ultimately reduce the thread processing accuracy,or even scrap.Therefore,how to reduce the interference in thread milling process and make the process more stable is the key issue to improve the quality of thread milling.In this paper,aiming at the non-symmetric thread milling,by means of curve parameterization theory,the thread cutting and tool design theory,MATLAB,VERICUT,UG and AdvantEdge software,through the analysis of interference mechanism,the profile of tooth is defined,and the influence of tool profile on interference in non-symmetric thread milling and the influence of tool rake angle on cutting performance are explored.The work is as follows:1)Interference analysis of NC milling of non-symmetric thread holes.In accordance with the definition of standard thread and the design theory of thread milling cutter,the milling principle and motion characteristics of non-symmetric cylindrical thread holes are analyzed,to explore the causes of milling interference,the two-dimensional profile equation of non-symmetric cylindrical internal thread and the profile equation of non-symmetric thread milling cutter are derived,subsequently the parameterization equation of ideal non-symmetric profile of cylindrical thread and the parameterization equation of thread milling process trajectory are derived,based on MATLAB,the interference in NC milling process of non-symmetric thread is analyzed.2)The establishment of contour optimization algorithm for Non-Symmetric cylindrical thread milling cutter is based on the analysis of interference in NC milling of non-symmetric the thread holes,considering the marvelous diameter and pitch of non-symmetric thread milling cutter have great influence on machining interference,an optimization algorithm of thread milling cutter contour is established to adjust and construct six feature points of thread milling cutter profile,the validity is verified by VERICUT machining simulation and thread hole milling experiment.3)Analysis on the effect of milling performance of the rake angle of non-Symmetric cylindrical threaded the milling cutter.The process of non-symmetric thread milling is simulated by using the finite element simulation software AdvantEdge,in order to explore the influence of non-symmetric thread milling cutters with different rake angles on cutting force and cutting temperature in thread milling,based on this,a more reasonable rake angle are designed and selected.In conclusion,this study will offer a scientific basis for the optimal design of non-symmetric cylindrical thread milling equipment and hopefully further realize the precision milling of non-Symmetric thread.