Simulation And Experimental Investigation Of Controllable Pitch Propeller Milling

The blade of controllable pitch propeller(CPP) is a typical part with sculpture surface, and its design and manufacturing precision directly affect the propulsion efficiency and service life of the rotary propeller in the dynamic positioning system. Under the ocean environment of blade service, subject to the time-varying loads and torque loading, there are strict modeling and manufacturing requirements on the geometric accuracy and thickness distribution of the blade profile. CNC milling process take the longest time and highest machining accuracy of a process, so choosing the milling process parameters is important to improve the surface quality and processing efficiency of the blade.In this article, CPP-blade geometry and modeling features principle is analyzed firstly. Based on blade design patterns, leaf section is derived from feature point data into three-dimensional data points coordinate conversion formula. Based on UG secondary development, the data points to fitting a curved surface profile, getting swept by the way blade surface, and building a blade parametric modeling platform. Secondly, a working surface topography simulation algorithm is established in terms of bull-nose end milling. A mathematical model has been established to uniformly describe its geometric characteristic. Considering of the relative motion relationship between the tool and workpiece, a quaternion transformation model is established to describe the translation and rotation motion of tool coordinate system and the workpiece coordinate system by using Z-map method of surface morphology on a milling workpiece to calculate simulation in Matlab.Finally, this article analyzed CPP-blade CNC milling process, based on parameters studied and blade milling strategies, in accordance with the selected parameters generated interference free tool Path in UG, using VERICUT software to build a digital model of the machine. The resulting toolpaths interference and collision detection using OptiPath module has been optimized based on material removal rate.OptiPath module has been optimized based on material removal rate constant feed rate. At the same time, CPP-blade machining experiments have been carried out, the processed tool path program has been applied in the experiment by using non-contact measurement solutions. This article measured and analyzed the blade through the processing scanned points with cloud data, and evaluated the accuracy of blades machining based on processing standards.The CPP-blade machining process verified the technique that researched in this article and the programming method was effective. It provides a reference for the selection of process parameters and preparation of toolpath.