Research On Less-Interference-Based Spiral Milling Method And It's Tool Design For Threaded Cylindrical Holes

As one of the common connection methods,threaded connection is widely used,which is commonly used to connect key fasteners and structural parts.The quality of its processing directly affects the service life of threaded products.At present,with the increasingly development of NC technology and equipment,thread milling has become an efficient thread processing method.However,in the process of precision milling of thread,because the structure of the thread milling cutter is very complex,the envelope surface of the tooth profile does not conform to the nominal screw spiral curved surface,so it can not avoid the processing interference.Therefore,how to optimize the contour of the thread milling cutter to reduce the interference of the thread milling has become Hot spots of the thread milling technology in recent years.Therefore,based on the principle of tooth profile formation and the principle of thread milling,the interference mechanism of thread machining was analyzed,the interferometric model of thread milling was established,the contour optimization model of thread milling cutter was built,and MATLAB was used to program,calculate and analyze,Finally,the experiments were carried out to verify the established interference and optimization models through VERICUT virtual simulation and numerical control cutting.The contents of the specific research work are as follows:1)Research on milling principle and interference of cylindrical thread hole.The principle and motion characteristics of cylindrical screw hole milling was investigated.Through in-depth analysis of it,the causes of interference in cylindrical screw hole milling were obtained,and the milling process of cylindrical threaded holes was parameterized,and the mathematical model of interference theory of cylindrical thread hole milling was established.2)Optimization design of cylindrical thread milling cutter was conducted.Through the principle of tooth profile formation and the machining interference mechanism of cylindrical thread milling cutter,the overall design scheme of the program was determined,and based on the interference mathematical model of cylindrical thread hole machining in 1),the contour optimization model of cylindrical thread milling cutter was obtained.The optimization model was verified by MATLAB software,and the corresponding program was designed and compiled to complete the design of cylindrical thread milling cutter.3)Simulation and experimental verification of cylindrical thread hole cutting were implemented.The NC machining simulation software VERICUT was used to simulate the machining process of cylindrical threaded holes.The safety of the machining process of cylindrical threaded holes and the rationality of the establishment of simulation system was analyzed,and the accuracy of the cylindrical thread milling cutter profile optimization model was verified,and the experimental verification is carried out by NC machining.In conclusion,this study lays a theoretical foundation for reducing the interference of cylindrical thread hole milling and establishing the high efficiency and low cost milling of internal and external threads,and it also provides a scientific basis for promoting the application of precision milling technology for cylindrical thread holes.