Hyperboloidal sharpening method for multi-flute curved edges drills

Abstract

This paper presents an analytical model of a sharpening method for helical drill with curved edges, characterized by a main hyperboloidal shaped placing surface, with an edge with a fluctuating angle of incidence, decreasing along the cutting edge. Such a shape of the main cutting edge ensures an even, unitary energetic charge along the cutting edge. The analytical model of the cutting edge and of the shape of the back face is analyzed and conditioned to meet the minimal requirements of drills’ sharpening process: the size of the back angle along the cutting edge, obtaining relieving of the main back face at a single positioning of the tool, in relation to the sharpening surface.