Research On Numerical Simulation Of Vibration Extrusion Tapping

With the rapid development of high technology, technology integration has become a powerful driving force for the progress of plastic processing technology. Vibration extrusion tapping as a fusion product of extrusion tapping technique and vibration machining technology,it not only has the most advantage of extrusion tapping,but also can reduce the tapping torque, improve the surface quality of thread,and provide a method for precision and anti-fatigue of internal thread.The article study on extrusion forming process of vibration tapping by the method which combined numerical simulation and experiments.The main contents and results of this study are as follows:(1)The theoretical basis of the vibration extrusion tapping is studied.The movement mechanism in the process of extrusion vibration tapping is obtained by studying on extrusion tapping theory and vibration plastic processing theory;and doing theoretical research for the friction characteristics,the thread surface metal reinforcement mechanism and the tapping torque mechanism reduction in the vibration extrusion tapping process.(2)Establishing the finite element model of rigid plastic extrusion vibration tapping. The finite element model for process condition is established through these steps that setting up the geometrical mode, defining the work-piece material properties,exercising load vibration and defining the contact boundary conditions.(3)The thread of tooth shaped plump and smooth surface is obtained by using DEFORM-3D to forming simulate for internal thread vibration extrusion process which can effectively improve the surface quality of extrusion vibration tapping screw; The distribution of equivalent stress and strain is analyzed,and the conclusion that metal deformation is uniform and other parts of the work-piece deformation is small in the screw deformation zone is obtained; Analyzing the metal flow velocity field and velocity field along the tooth form a streamline shape,which illustrates that metal material will flow to tap tooth groove under vibration extrusion;The periodic changes of torque waveform is obtained by studying the change regulation of vibration tapping torque extrusion process.Finally analyzing the influence of bottom diameter, vibration frequency and amplitude parameters for the extrusion process of vibration tapping.(4)Under the same conditions,contrasting and analyzing the information of thread profile and torque by testing and simulating the vibration extrusion tapping.The numerical simulation results and experimental thread tooth profile are similar;The torque variation process and the torque waveform cycle obtained by numerical simulation are the same as the results obtained by the test,however the amplitude of torque waveform has a certain error.