Whirling Vibration in Drilling. Part 2: Influence of Drill Geometries, Particularly of the Drill Flank, on the Initiation of Vibration

Abstract

The development of whirling vibration is observed by using drills with various web thicknesses, point angles, relief angles, and various helix angles in order to investigate the effect of drill geometry on the initiation of vibration. It becomes clear that the flank surface of the major cutting edge can dampen the vibration. This, plus the fact that the chisel edge exerts a restraining effect (Part 1), makes it clear that the initiation boundary of the whirling vibration can be specified by two parameters, the chisel edge length and the flank surface configuration, which can be represented by a flank collision index introduced.