SELECTION OF THE FASTER POCKETING STRATEGIES FOR REDUCTION OF MACHINING TIME IN MANUFACTURING OF CAR WHEELS-RIMS

Abstract

Pocketing is one of the milling operations most used in the aeronautical and automotive sector. They are employed in the roughing during the manufacture of complex geometries, for dies cavities and moulds, as well as for the machining of pockets of simple geometry. In literature, there are many works focused on the generation of new strategies that allow machining complex geometries by reducing the cutting forces generated or obtaining a best surface quality. However, there are hardly any work focused on the study of the milling of pockets with simple, but with great industrial interest geometries. In this case, by its presence in many components of products manufactured in mass causes, the most important parameter to control is the machining time. In the present work, we studied what strategy is the most efficient in the pocketing of an aluminum car wheel. The strategies employed have been: direction-parallel (one-way, zig-zag), parallel to the contour (contour-parallel, cleaning the corners, constant) and the spirals (real spiral, morph spiral). It has been used a simple design of a wheel, formed by four simple geometries: large circular, small circular, triangular and rectangular. The results show that the family of parallel strategies to the contour are the fastest, even in the machining of circular pockets, where apparently the spiral strategies could have some advantage. In three of the geometries studied (large circular, small circular and triangular) the winning strategy has been the contour-parallel. However, the global faster strategy is the constant. Besides, in non-passant pockets (small circular ones, in this case), it is interesting to choose this strategy since it guarantees the removal of excess material in the corners and changes of direction of the tool. Keywords: tool path; pocketing strategy; optimizing; machining time; automobile parts