Research On Dynamic Simulation Technology Of Multi-axis Milling Process For Marine Propeller

Now marine propeller generally is machining by three coordinate machine tool, butwith the advent of multi-axis CNC machine tool for the marine propeller, propeller ismachining by these machine tools. Multi-axis machining with respect to three-axis adds totwo or more degrees of freedom, which is conducive to machining free-form surface andimprove the quality of workpiece. However, during multi-axis milling process, changes inthe tool axis direction make the tool path planning more difficult. In addition, now millingdynamics simulation mainly focus on three-axis machining process, the dynamicssimulation about the multi-axis milling process is only just started. In order to solve theabove problems, the CNC machining process planning of marine propeller, the geometricsimulation and dynamic simulation for multi-axis milling machining process and otheraspects are researched, the geometry-dynamics integrated simulation system for multi-axismilling machining process is developed on this basis. The main research topics and resultsare as follows:(1) Analysis the CNC machining process of marine propeller, including the propellerhub machining, blade machining, blade root processing and trailing edge and guide edgemachining. The CNC machine tool and tool is selected reasonably for each process step.Finally, the tool path is simulated by UG CAM variable axis surface profile module formarine propeller finish process.(2) Analysis the geometry modeling method of geometric simulation process, the toolmodel is built in the OpenGL. Propeller blank is imported into OpenGL as UG STL format,the cutter location file is read and the OpenGL basic is set, the linear interpolation of thecutter sites is made, tool machining trajectory is displayed. The tool swept volume issolved by explicit expression method. Under the theory of Dexel, the propeller blank andtool swept volume Dexel model were build, three-dimensional Boolean operation issimplified to one-dimensional operation, greatly improving operational efficiency, andultimately the tool cutting material removal process is achieved.(3) Analysis cutting force of the differential element and geometry characteristic ofball end mill, instantaneous rigid milling force model is built, cutting force coefficient isobtained by milling force experiment and mathematical model, Substituting it into themilling force model, the final milling force simulation result is got. The chatter stability model of marine propeller for multi-axis milling process is established, on the basis of thedynamic chip thickness model, the chatter stability region dynamic is got by solvingdynamics equation, With compared the simulation results and software CutPro, then on theimpact of oriented transfer matrix function, the lead angle and the tilt angle, differentchatter stability simulation results is got. In addition, the modal parameters of spindle-tooland workpiece-fixture system are measured by modal analysis test. Finally, the simulationprocess is achieved by Matlab and Visual C++combined with mixed programmingtechnology.(4) Finally, geometry-dynamics integrated simulation system of marine propeller formulti-axis milling process is developed through the Visual C++program, describing therelevant interface and module, running simulation system by instance.