PRECISION DIE FORGING METHOD FROM PLANAR BLANK BY PRESS

摘要

PROBLEM TO BE SOLVED: To manufacture thick rings from a planar blank by means of a press by pressing, in the second process, a rough mold obtained in the first process from a direction opposite from the first process, thereby correctively working the shear drop or the grade of a sheared section caused in the first process and forming a precision die. ;SOLUTION: With a rough die 23 formed in the first process, reversed and placed on the female die 2 of a die set part 1 in the second process, a punch 4 is lowered. Then, since the bore of the female die 2 is formed with a small diameter so as to be the finishing bore of a ring gear 26, the mold is reduced in the form where the bore is parallel to the punch insert; also the outer shape of the gear and the die in the second process being smaller than the rough die 23 by a few millimeters, during the sizing working by the die and the punch, with the rought die 23 drawn and reduced by the female die 2, the drawn excess thicknesses flow into the shear drop or the grade part of the sheared section caused in each process, thus forming a precision ring gear corrected to a condition with little shear drop or grade.;COPYRIGHT: (C)1997,JPO