Research On Micro Edm Based On Electromagnetic Actuator

Micro electrical discharge machining(EDM)has a wide range of applications and is capable of machining all electrically conductive materials without direct contact between the electrode and the workpiece,and the workpiece is not easily deformed.It is widely used in abrasive tool manufacturing,aviation field,machining and other fields.However,the low machining efficiency restricts the further development of microfabrication EDM.In this paper,we designed a five-degree-of-freedom electromagnetic actuator for micro EDM using two permanent magnet rings and eight sets of hollow coils and connected it to a micro EDM machine tool to address the problem of low efficiency of micro EDM.Achieving high speed and precise positioning in the axial direction can effectively reduce abnormal machining,facilitate chip removal and improve machining efficiency;achieving large stroke in the radial direction enables machining of complex shapes even with simple electrodes.Firstly,the overall structure of the five-degree-of-freedom electromagnetic actuator is determined.Secondly,the working principle and driving principle of the electromagnetic actuator are introduced,the dimensional parameters of the electromagnetic actuator are obtained according to the finite element simulation analysis of the electromagnetic actuator,and the prototype of the electromagnetic actuator is fabricated.Simulation analysis of the magnetic field of electromagnetic drive and simulation analysis and experimental study of magnetic field characteristics of electromagnetic drive to verify the accuracy and feasibility of magnetic field simulation analysis and the effect of the presence or absence of armature on magnetic induction strength.The mathematical model of the electromagnetic drive is established,and the electromagnetic force of the electromagnetic drive is simulated and experimentally compared and analyzed,and the reliability of the prototype pair of the electromagnetic drive is verified.Design the PID control system of the electromagnetic drive and simulate the response speed and dynamic output performance of the electromagnetic drive using MATLAB/Simulink.The experimental system of electromagnetic drive is built and the simulation results are verified;the experimental results show that the electromagnetic drive has a fast response speed,low overshoot and short adjustment time;the dynamic performance is good and the following performance is superior,which can fully meet the requirements of micro EDM;the positioning resolution in X,Y and Z directions can reach 5μm,and the positioning resolution in rotation direction can reach 50μrad.The experimental control system of micro-fine EDM based on the electromagnetic driver was designed and built;the comparative analysis of conventional micro-fine EDM and electromagnetic driver based micro-fine EDM was carried out in three aspects: inter-pole feedback voltage,machining efficiency and surface quality respectively.The experimental study shows that compared with the traditional micro EDM based on the electromagnetic driver,the micro EDM has the following advantages: it can quickly control the positioning of electrodes,quickly adjust the discharge state,reduce the occurrence of abnormal discharge and increase the probability of discharge;shorten the machining time;and increase the average machining speed by 32.9%.