A new mathematical model for helical drill back face geometry study

Abstract

In this paper is showed a new analytical methodology for the study of the drill main back surface geometry. It’s analyzed the back surface of the drill’s main cutting edge as enveloping of a plane surface of the active zone of abrasive wheel, method equivalent with the conical sharpening proceeding. It is used the in-plane trajectories method for the enwrapping surfaces study. Is showed the form of the back face, the relieving lines on various points of the main cutting edge, the form of the crossing cutting edge and the variation law of the back angle along the drill radius. Also, we make mentions regarding the kinematics and constructive parameters influence on the back angle value along the drill’s cutting edge.