System Design And Simulation Research Of Arc Plasma Deep Hole Curve Machining

Arc plasma deep-hole machining technology is based on the erosion of the workpiece by t he plasma generated by the pulse discharge in the discharge gap,this technology has the charact eristics of high processing efficiency,not limited by mechanical properties of materials,no cutti ng force,etc.It can effectively solve the problems of low efficiency and high tool loss rate of di fficult materials in traditional drilling.However,arc plasma deep hole machining technology is still unable to complete the curve deep hole machining.Aiming at this problem,this paper prop oses to introduce magnetic field into arc plasma deep hole machining on the basis of fully under standing the functional characteristics of arc plasma generated by pulse discharge in the dischar ge channel during the process of magnetic field and arc plasma deep hole machining.Arc plasm a processing technology is used to process curved deep holes.Firstly,the generation and classification of arc plasma and the mechanism of deep hole ma chining by arc plasma are studied.,and then the influence of different magnetic field directions on the trajectory of arc plasma and the distribution of plasma arc is analyzed.The results show t hat under the longitudinal magnetic field,the arc plasma in the discharge channel is only affecte d by the electric field force,and the arc plasma rotates around the axis of the electrode at a high speed,which changes the arc shape and makes the temperature and current density distribution of the plasma arc more uniform,which is helpful to improve the machining quality.Under the a ction of transverse magnetic field,the arc plasma in the discharge channel will be affected by th e electric field force and Lorentz force at the same time,and the movement direction of arc plas ma will be changed,which will lead to the deep hole generated by arc plasma machining deviati ng from the geometric center of the workpiece,which is helpful to realize the arc plasma machi ning of curved deep hole.Secondly,transverse magnetic field is applied to arc plasma deep hole machining,a tool el ectrode containing liquid supply channel and internal chip discharge channel was designed.An electromagnet composed of a coil wound outside the iron core and a DC power supply was sele cted as the magnetic field generating device,and RC pulse power supply was selected to provid e energy for the machining process.Finally,the cooling and circulating filtration system of wor king fluid is designed.Together constitute a transverse magnetic field assisted arc plasma curve deep hole processing system.Finally,based on the theory of magnetohydrodynamics,the simulation analysis of transver se magnetic field assisted arc plasma curved deep hole machining is carried out.Firstly,the con trol equations of arc plasma under self-magnetic field and external transverse magnetic field we re established respectively,and the simplified geometric models were created in the sketch wind ow of COMSOL Multiphysics finite element simulation software,and then the boundary condit ions were set reasonably according to the actual processing conditions.The simulation models u nder the self-magnetic field and external transverse magnetic field are obtained,and then the m odel grid is divided,and finally the simulation models under the self-magnetic field and externa l transverse magnetic field are solved.By contrast,under the action of magnetic field,plasma ar c isotherms are distributed in the shape of bell jar,which makes the deep hole generated by arc plasma processing located in the center of the workpiece.However,under the action of external transverse magnetic field,the distribution of plasma arc isotherms will shift to the left of the ar c center,which will make the deep hole produced by arc plasma machining gradually deviate fr om the workpiece center,so as to realize the curved deep hole machining.When the machining current and magnetic induction intensity increase,the arc plasma velocity under the magnetic fi eld and the external transverse magnetic field increases,which is conducive to improving the m achining speed.Moreover,the plasma "reflux" phenomenon under the external transverse magn etic field is weakened more obviously,and the loss of cathode electrode can also be reduced.