Research Of Point Thinning Methods For New Helical Micro-drill And Its Simulation Based On CAD System

As the first region contacting the workpiece, the chisel edge has a significant influence on drill cutting performance and this is closely related to the chisel edge profile and geometrical properties. Comparing with general purpose drill, the higher web thickness-diameter ratio of micro-drill makes a greater contribution to the action of chisel edge. Along with the rapid development of modern precise manufacturing and micro-electronic manufacturing, the demand in micro-drill keeps increasing. Considerable research on drill grinding has been conducted at home and abroad, but research on point thinning methods for drill bit especially for micro-drill bit is rare.The processing characteristics of micro-hole drilling have been reviewed, the existing problems and its current development status are summarized, the phylogeny of drill flank grinding and point thinning is presented in this paper.According to the principle of flank grinding of new helical drill and planar drill, the mathematical models are derived. The advantages and disadvantages of new helical drill are obtained compared with the geometrical characteristics of planar drill point by Micro-drill CAD and Simulation System.In view of micro drill, two point thinning methods are proposed. Combining with three location layout CNC grinding machine, the mathematical models are established, besides, the geometrical angles along thinned chisel edge are defined and solved. Point thinning sub-module and comparison module are added to the Micro-drill CAD and Simulation System. Simulation and comparison of new helical drill are conducted based on this system.Placing the point thinning in an independent location, a new point thinning method is proposed aimed at small drill. According to arbitrarily selected drill geometrical parameters, the drill points thinning parameters are calculated accurately and rapidly by computer simulation, the chisel edge angle distributions both before thinning and after thinning are obtained. Precise 3D models of drill are developed by UG software, which is prepeared for the further research of drilling simulation.Systematic research on point thinning method is conducted in this paper, and the results indicate that the cutting performance of thinned micro-drill is significantly improved.