Patent ID: 7665937
Filing Date: 2010-02-23
Classification: B23C,B23Q,Y02P,Y10S,Y10T

Abstract:
1. A method of milling a magnesium workpiece with an end milling cutter comprising a central longitudinal axis about which said end milling cutter is to be rotated, said end milling cutter comprising: a rotatable shaft comprising an internal channel disposed in said shaft; said internal channel being configured to receive and guide chips produced during a cutting process; said internal channel being configured to be operatively connected to a suction device configured to create a suction force in said internal channel to suck chips produced during a cutting process through said internal channel; a milling head being disposed at an end of said shaft and being connected to said shaft to be driven and rotated by said shaft in a cutting operation, wherein said rotatable shaft comprises an inner diameter, said milling head comprises an outer diameter, and the inner diameter of said rotatable shaft is smaller than the outer diameter of said milling head, at least in an area that borders said milling head; and said milling head comprising: an end face being disposed at an end of said end milling cutter and facing away from said shaft; said end face being substantially orthogonal to the longitudinal axis; said end face comprising a substantially flat solid portion being disposed substantially in a plane; a peripheral side surface disposed about the perimeter of said milling head; a cutting structure being configured to cut an object in a cutting process; and said cutting structure comprising: a face cutting edge being disposed to lie in said end face and substantially in the plane of said end face of said milling head; a peripheral cutting edge being disposed to lie in said peripheral side surface of said milling head; at least one of said cutting edges being configured to form a positive rake angle; upon said face cutting edge forming a positive rake angle, said face cutting edge being configured as follows: (a) said face cutting edge and said peripheral side surface forming an angle, across a solid portion of said end face between said face cutting edge and said peripheral side surface, at the intersection of said face cutting edge and said peripheral side surface; said face cutting edge angle comprising an acute angle configured to form a positive rake angle; upon said peripheral cutting edge forming a positive rake angle said peripheral cutting edge being configured as follows: (b) said peripheral cutting edge and said end face forming an angle, across a solid portion of said peripheral side surface between said peripheral cutting edge and said end face, at the intersection of said peripheral cutting edge and said end face; and said peripheral cutting edge angle comprising an acute angle configured to form a positive rake angle; said method comprising the steps of: rotating said rotatable shaft and driving and rotating said milling head; creating a suction force in said internal channel using a suction device operatively connected to said internal channel; bringing said milling head into contact with the magnesium workpiece; cutting the magnesium workpiece with said cutting edges of said end milling cutter and producing magnesium chips; and sucking the magnesium chips into and through said internal channel in said shaft and conducting the magnesium chips away from the magnesium workpiece to essentially prevent combustion of the magnesium chips; and essentially preventing combustion of the magnesium chips.