Research Of 5-Axis Machining Technology For Large-scale Marine Propeller

Large-scale marine propeller is the core component of a ship. The quality of propeller determines the performance of a ship.5-axis NC machining is the significant means to actualize the high quality and efficiency machining of complex surface parts, especially marine propeller. The background of the thesis is the 863 program"Heavy 7-5 axis lathe & mill machine tools for large-scale marine propeller". The CNC process planning of propeller, 5-axis NC programming technology, multi-axis post processing and NC machining simulation is researched on.Reasonable NC machining process planning weighs a lot for quality and efficiency of the marine propeller. Basing on the analysis the geometry characteristic and machining requirement of marine propeller, and according to the specialty of 7-5 axis machine tool, the NC machining process planning of propeller is established. By the machining process planning, the machining working procedure of propeller blade is come true.The propeller blade can be divided into two pieces, overlapped and non-overlapped, which machined by standard milling cutter and special milling cutter. Considering interference-free and machining efficiency requirement, the division of overlapped pieces and non-overlapped pieces is optimized by blanking the cutter radius and collision stock. Interference-free 5-axis NC tool-path of the two pieces generated after selecting cutter and milling parameter.The 7-5 axis lathe & mill machine tools is more complex than standard 5 axis machine tool. The kinematics model and solution for standard milling cutter and special milling cutter is done by analyzing their structure. Feedrate validation is the key function of post processing, and has significant influence on the quality of marine propeller. The feederate is well controlled by considering the dynamics characteristic of the 7-5 axis machine tool.The blade surface of marine propeller is very complex, and the interference & collision is tough to avoid. Therefore, the validation of NC program is absolutely necessary. The 5-axis simulation platform of the 7-5 axis machine tool is established with VERICUT.Finally, by the research on 5-axis NC machining technology of marine propeller, the propeller blade is under machining. The machining procedure is stable, interference-free and collision-free.