PRODUCTION OF PRESS MOLD FOR PUNCHING SMALL HOLE

摘要

PURPOSE:To press-mold small holes of a printed board or the like by using a punch formed by reverse electric discharge machining as an electric discharge machining electrode and the die of a press mold as a workpiece to mold a small gap by electric discharge machining. CONSTITUTION:A punch material 1 fitted to the chuck section 2 of an electric discharge machine is connected to a positive electrode 5 and an electrode molding block 3 is connected to a negative electrode 6, a capacitor 7 is connected, and a reverse electric discharge is performed while the punch material 1 is rotated to mold a punch 8. Next, the punch 8 is connected to a negative electrode 6 as an electric discharge machining electrode and a die 9 is connected to a positive electrode 5, a capacitor 7 is connected, and electric discharge machining is performed to mold the die 9 of a press mold. In this case, the voltage and the capacity of the capacitor can be controlled so that the clearance between the punch 8 and die 9 is made about 2-5% of the hole diameter, thus allowing press machining of a small hole of about 0.1-0.2mm.