MACHINING METHOD FOR PUNCH PRESS DIE, AND THE DIE

摘要

PROBLEM TO BE SOLVED: To prevent seizure and the like by doing away with the thermal deformation of a die edge portion after finishing work, machining the shape and size of a workpiece with high precision and improving the discharge of minute chips produced in drawing the workpiece out of the die. SOLUTION: In finishing edge portions on die base metal 1 previously heat- treated and machined into a given shape, the machining method for a punch press die cuts the edge portions with a rotary cutting tool while injecting inert gas to the cutting region of the die base metal 1 to cool the cutting region with the inert gas, wherein a plane including the axis of the rotary cutting tool 7 is perpendicular to a die edge face 11 and the rotary cutting tool 7 is provided with micro feed motion causing it to abut on and separate from the die base metal 1 repeatedly. The die for use in a punch press is so constituted that fine recessed surfaces 17 long in a direction crossing the die edge face 11 are formed on an edge periphery 13 crossing the die edge face 11.