Principle And Method Of Osculating Machining Marine Propeller With High Feed Cutter

Marine propeller is a kind of typical free-form surface part, its blade is complexity, machining accuracy and surface quality are directly related to the efficiency of ship propulsion, vibration, manipulation performance and blade strength. With the development of multi-axis numerical control technology, marine propeller are usually machined by5-axis machine tool, however, due to the restriction of tools and machining methods, the machining accuracy and efficiency are still not ideal. In addition, the tip of the blade is always thinner, which lead to deformation easily, so there is a higher demand for the stability of the machining system. Therefore, research of selecting tool types and machining methods is vital to ensure the stability of machining system, improve machining accuracy and efficiency.In this thesis, principle of blade formation and characteristics of blade are firstly analysised,then the section data is transformated into three-dimensional data.Using MATLAB programming language, and based on cubic B-Spline interpolation theory, blade surface and propeller model are constructed, furthermore, on basis of MATLAB software GUI platform, the graphical user interface of propeller geometric modeling system is designed.High feed cutter (HFC) is introduced and osculating machining method is presented, comparted with fillet-end mill, geometric properties and cutting force characteristics of HFC are analysised, the fundamental of calculation of osculating cutter location is investigated in detail, after that, the osculating machining error by HFC is given. Combining the differential geometry features of blade surface and the osculating condition between cutter and blade, the selection principle of tool parameters is discussed, finally, the osculating tool position of blade surfaces machining by HFC are calculated.For casting blank, with the help of multi-axis machining module in UG, rough milling and simulation process of propeller are carried out. For the hub, a tool path planning method based on interpolation is studied, and then, the determination of tool axis vector is given. Moreover, by use of "mill_multi_blade" module in UG, the hub of propeller is machined and simulated, which verified the former tool path planning method.