| 摘要 |
PURPOSE:To achieve completely automized machining of the bearing hole and the back runoff by forming a back runoff using the wire-cut electric discharge machine after machining a cutout of a predetermined dimension at the position where the back runoff is to be formed. CONSTITUTION:When machining the back runoff 3 of the mohair section 23 of an extruding die, in another words, the inclined face 6 of the back runoff by an electric discharge machine having a wire electrode, the inclined face 6 of the back runoff is machined after a cutout 25 is formed. Thus according to this method, as a free piece 24 which causes unstability during machining is removed in advance, machining of the back runoff 3 can be carried out smoothly without interruption throughout the process. The smallest possble value of the height H and width W of the cutout 25 can be determined and the cutout 25 is machined by a milling machine having a milling cutter, or by an ordinary electric discharge machine. Thus as the whole process can be automized completely, the number of manufacturing processes and the manufacturing cost can be reduced and also the mechanical strength and accuracy can be improved. |
