Research And Development On Modeling And Simulation Of VNC Turning Machining Process

Virtual Manufacture(VM)is a key technology of achieving Internet Manufacture N Agile Manufacture (AM) and Computer Integration Manufacture System (CIMS), fathomers, the modeling and simulation technologies of Virtual Numerical Control (VNC) Manufacturing process is basal and kernel technology unit of VM , especial is the studies of physical simulation. The system's studies are carried out in this paper around modeling and simulation of virtual numerical control manufacturing process.1. The curling reasons, breaking conditions and generating thickness, width, curling radius and length of chip are discussed, and numerical simulation models are built according to formation mechanism of chip. The 3-D solid models of chip are given according to classification criterion of chip. A type chip is modeled and analyzed through FEM. The affect factors, such as strain, stress, shear stress, and principle stress of inner and outer surface of chip, on chip generation, curling, breaking, as well as shape and section parameters are analyzed. Comparisons made between the experiment analyses in relative literature and finite element models show good correlation, and the forecast ability of FEM simulation in chip formation was proved. Furthermore, the influence of machining parameters on the geometry dimension and type of generated chip are analyzed.2. The machining errors are abstracted to technologic system geometry error and machining physical error. In order to build completely precision evaluation model, a kind of integrated error model, which brings into machine tool, fixtures and cutter effect on machining error, is given. The influence of cutting force on machining precision of shaft is simulated by FEM. Comparisons made between the theory calculation and finite element models show good correlation, and the forecast ability of FEM simulation in chip formation was proved.3. According to N-084/22 NC lathe by produced in Nanjing Machine tool Company, the modularization virtual facility model of NC lathe is modeled include NC lathe, fixtures, cutter and workpieces etc. with large CAD/CAM three-dimension software Pro/E by measuring dimension of parts and component.4. On VC++ platform, the simulation system of VNC turning process is developed by Pro/TOOLKIT development module of Pro/E, and by integrated the above geometry simulation models of NC lathe and the mathematical models of chip. The system possesses visible UI, interactive inputting workpiece and machining parameters, cutting collision and interference, vacancy journey show and real-time display machining process and chip's generation, curling and breaking, manufacturing quality evaluation, as well as operators and programmers train function etc. .