The Machining Error Modeling And Strip-width-maximization Method For Orthogonal Turn-milling

With the development of automobile, aerospace and shipbuilding industry, more andmore complex shaft parts, such as landing gear and marine propeller, has been emerging inindustrial application. Consequently, the orthogonal turn milling has been graduallydeveloped since1980s. So far, orthogonal turn-milling is a widely-used processingtechnology in modern metallic cutting technology.With widespread application of turn-milling technology in recent years, machiningfeature for orthogonal turn-milling gradually evolves from cylindrical surface to ruledsurface, including camshaft face, screw pump blade and lugs of aircraft landing gear. Inthe manufacturing procedure of ruled surface, the current tool path planning method fororthogonal turn-milling generates relatively small strip widths and uneven machining errorwith the result of lower machining efficiency and precision.Due to the defect of current tool path planning method, the forecasting model ofmachining error for orthogonal turn-milling is present. Based on the multi-body kinematictheory and shape interrogation technology, the analytic expression of local cutting shape isderived to improve computational accuracy of machining error. The correctness offorecasting model is verified by comparison with effective cutting shape and sweptenvelope，which lays the foundation for the analysis of influencing factor and rules inmachining strip-width.The machining strip-width for orthogonal turn-milling is affected by many factorswith mutual interaction. In order to determine relationship and mechanism among variousfactors, orthogonal experimental design is employed by using range and variance analysison the calculating results. Experiments are further conducted by measuring finishedsurface to verify the effect of cutter eccentricity and curvature radius.Finally, strip-width-maximization method for orthogonal turn-milling is presentedbased on error constraint of distance function. Hasudorff distance and Fréchet distance areadopted to describe maximum deviation and distributed condition of machining error.Combined with mechanism of cutter eccentricity in orthogonal turn-milling, larger machining strip-width for orthogonal turn-milling can be obtained by optimizing cuttereccentricity at different positions. The experiment shows the proposed method caneffectively enlarge machining-strip width and improve distribution of machining error.