Study On Micro Electrical Discharge Milling Machining NC Motion Control With High Spindle Speed

As the development of micro/nano technology as well as increasing demandrequired in aviation, national defense, medical treatment and other areas, as animportant way to achieve micro machining, micro electrical discharge MillingMachining technology has become the hot pot in recent years. NC system as the core ofmicro EDM machining tool, determines the stability of machine tool and machiningefficiency. Therefore, it is of great significance to study the NC system of micro EDMmachine tool with high rotating speed of tool electrode, which can develop themachining performance of machine tool and realize future research on the machiningcharacteristics of micro EDM.On the basis of consulting large numbers of literatures, this thesis completesoverall design of the NC system of micro EDM machine tool with high rotating speedof tool electrode, designs the motion control software based on PMAC, then carries outmicro EDM technology experiments and studies the principle of EDM method tomachine U-type with deep and narrow feature.In this thesis, hardware of NC system for micro EDM machine tool is designed andelectronic circuit for gap discharge status detection built, which can achieve correctjudgment to short, open circuit and normal machining. By designing motion controlsoftware, this thesis realizes communication between industrial control PC and PMAC,sending orders from man-machine interface to motion controller and othersupplementary functions. Servo motion controlling program is compiled to guarantee tofeed on condition of open circuit and feed back on condition of short. On the basis ofabove, using the way of static electricity response to offer pulse power, this thesiscarries out experiments of machining slight U-type with bar electrode, and studies theprinciple of two-layer milling, on the basis of which completes machining slight letterspattern eventually. Finally, based on the analyzing and studying of EDM method tomachine U-type with deep and narrow feature, the U-type with0.5mm in width and3mm in depth is obtained using round copper tool electrode. Experiments are carriedout to study the influence of spindle speed on surface roughness Ra,machiningefficiency and electrode wear, the results present that as increasing of tool electrodespeed from0rmp to10,000rmp, surface roughness Ra reduces34%, machiningefficiency increases93.1%and electrode wear reduces73%, which indicates that byincreasing rotating speed of tool electrode, good machining quality, high machiningefficiency and low electrode wear can be obtained.