Analysis Of Working Proess Of Automatic Tapping And Influence Law Of Tapping Life

With the rapid development of technology,higher requirements are placed on the performance of mechanical equipment.Threaded connections,as a convenient and reliable connection method are widely used in various mechanical related fields.And as an important part of the threaded connection,internal thread machining is still the most complex task in the current production processWith the rapid development of modem industry,especially the continuous implementation of the"Made in China 2025" program at this stage,more urgent demands are placed on the new production process.However,the traditional tapping machine is still widely available in the market and is the most important tapping tool to substitute manual tapping.In this situation,it is necessary to conduct in-depth exploration on the tapping process and its influence law,combined with simulation and experiment,quantitatively analyze the specific influence of each parameter,and summarize the influence law of the tapping process,so as to guide the actual production and get the effection of improving the tapping efficiency,reducing cutting force,optimizing machining quality,and decreasing tap tool abrasion.The specific research contents are as follows:(1)Through the analysis of the principle of metal cutting process,taking the force of the tapping surface of the tap into account,the influencing factors of the cutting force of the tap are inferred.The index formula and the cutting equation which are widely used to calculate cutting forces are analyzed to further summarize the influence degree and trend of the tapping cutting speed and the material properties of the workpiece.By comparing the applied axial force and the pressure of the tapping cutter facing the cutting surface,the influence of the axial feed force on the cutting force is summarized to provide a prediction and theoretical foundation for subsequent simulation and experimental verification.(2)Using finite element simulation software Deform-3D,a finite element 3D simulation model for tap cutting process was established in its pre-processing module to simulate the influence of three parameters of rotation speed,workpiece material and axial pressure on tapping torque.The simulation results show that the speed-torque law of different materials is similar.When the tap diameter is relatively small,the cutting force does not change much with the rotation speed;the axial force loading will increase the torque during the tapping process,the deeper the tapping depth,the more obvious the effect.(3)Design and manufacture a test machine that can be used to quantitatively change the rotational speed,axial force,select different inversion frequencies,etc.,and collect and store the tapping torque and cutting stroke in real time.The test verifies the reliability of the finite element simulation data,and obtains the reverse rotation of the tap at a certain frequency during the tapping process,which can reduce the overall tapping torque.The higher the frequency and the smaller the single cutting amount,the more obvious the tapping torque reduction effect.