Design Of Micro-punching Equipment Based On Micro-EDM And Experimental Research On Combining Processing

With the dramatic development and application of MEMS, requirement of microparts for the micro-devices is gradually improving. Especially, micro-holes have beenpopularly applied in the areas of diesel engine, airspay printer, spin industry andmedical equipments. Now, the existing fabrication processes have their own advantagesand disadvantages. In one hand, micro punching could machine micro-holes efficientlyin high-quality and low cost, while the fabrication of die is a problem. In the other hand,micro-EDM and ECM could machine hard conductive materials in high efficiency andquality, because of its low machining force and non-contact. Thus, study the combiningmachining process of micro-holes is meaningful in practice and application purpose.First, micro-punching process of micro-holes was simulated in the software ofDeform3D, which is based on the finite element method. In that simulation, materialdeform, stress distribution and in-wall quality was analyzed. Meanwhile, the impact ofrelative punching clearance and cutting edge radius of micro-punching tips onmaximum punching force was simulated and results were studied in the method ofone-factor variable. At the end, the eccentric punching was conducted to find the impacton material deform and stress distribution. By this way, guidance for the size ofmicro-punch and micro-die hole and adjustment of space position was proposed.Second, the paper proposed a combination process for the on-line fabrication ofmicro-punch and micro-die hole and micro-hole in the method of micro-punching; andECM equipment and micro-punching equipment were constructed based on themicro-EDM machine. By analyzing the mechanical properties, the structure and size ofmicro-die hole were designed. By studying micro-punching process and dividing thefunctional partition, the design of micro-punching die was completed.Third, experimental study of the combination process, including machining ofon-line micro-punch, micro-die hole and micro-punching of micro holes, was conductedon the modified micro-EDM machine. In this part,103μm micro-punch with smallcutting edge radius and110μm micro-die hole are machined successfully. Using thesemicro-punching die,105μm micro-holes was punching on brass foil in the thicknessof20μm. Using the method of response surface central composite, experiments wereconducted to study the impact of Capacity and Resistance value on deepness ofdischarge crater on micro-punch and machining efficiency. Meanwhile, the punchingforce was measured to confirm the accuracy of Deform3D simulation.