Influence of the radius of the generatrix of flank surface on the geometric parameters of the cutting wedge of the twist drill

Abstract

Drills with various flank surface shapes are widely used to machine holes. Drill teeth have flank surfaces of various shapes, flat, conical and helical. In this work, we have investigated the influence of radius of the generatriх in the form of a circular arc on the geometric parameters of the cutting wedge. It has been found that the range of changes in the clearance and rake angles along the cutting edge decreases with the decreasing radius of generatrix forming rake. It was found that a tool with a minimum permissible radius of curvature has the best distribution of rake and clearance angles of the blade along the cutting edge . The improvement reaches up to 40% compared conical flank surface. It was also found that in the case, when the generatrix radius decreases, the cutting edge increases by 18% compared to conical flank surface, which reduces the stress along the entire cutting wedge.