Key Technologies Research Of Virtual Numerical Control Milling Processing Physics Simulation

The numerical control processing simulation includes the geometry simulation and the physical simulation. As one area of simulation technology research, it is an important constituent of CAD/CAM integrative system.This article unifies the geometry simulation and the physical simulation organically together. Geometry simulation module includes semifinished materials geometry entity model, cutting tool geometry entity model and cutting tool scanning body model. When giving the model of semifinished materials body, the triangle surface piece separate method is used. We has realized the geometry intersention algorithm of separated vector and the cutting tool scanning body when entity machining is running on the 3 axis numerical control milling machine and has simulated the cutting process of the cutting tool through the unceasing renewal of semifinished materials data message.The physical simulation, taking the milling as the object of study, has established the model of vibration of milling processing cutter bar, the dynamic cutting force, the workpiece surface appearance and the processing precision. Taking the flexible cutter bar as the object of study, in the processing process the bias of main axle, distortion of the cutting tool under stress ,vibration of the cutter bar and so on caused the thickness of cutting to change which will be introduced into the mathematical model, then we will establish mathematical model that forecasts the dynamic cutting force. Based on the relative motion path equation between an arbitrary point in the cutting edge and the work piece and the milling process geometry characteristic in the processing process, we constructed a three dimensional superficial appearance simulation algorithm which may solve on the milling processing surface random appearance highly value and carries on the simulation demonstration to the work piece surface appearance. Considering the influence of the cutting tool stress distorts, cutting tool being heated distorts, the work piece being heated distortion and the cutting tool wears to processing precision, we establish the mathematical model to forecast the processing error .Finally, we choose high speed steel ball end milling cutter and 45 steel work pieces to carry on the cutting45 steel work pieces to carry on the cutting experiment and validate the rationality of the simulation model.