PRODUCTION OF RING GEAR BY PRECISE PRESS FORGING

摘要

PURPOSE: To simply produce a ring gear having thick thickness in a low cost and high precision with a press by correcting the rollover of a shoulder part and the gradient of a shear cross section developed in a previous process and simultaneously shrinking the outer diameter so as to become a desired finish outer diameter of the ring gear. ;CONSTITUTION: In a preform 24 formed through a first process and a second process, the rollover 25 is developed at the corner part of peripheral edge on the side surface of a female die 2, and in a shearing cross sectional surface, the preform is formed as the developing state of the gradient 27 in the shearing cross sectional surface. Further, this preform 24 is laid by turning over to the female die 2 of a side set part 1 and a punch 4 is made to descend. Then, since the inner diameter of the female die 2 is formed to the small diameter so as to become the finish outer diameter of the ring gear, at the time of drawing the preform 24 with this female die 2, the drawn excess thickness, etc., is flowed into the rollover 35 part and the gradient 27 part of the shearing part developed in the first process and the second process. Thus, the precise ring gear having the prescribed size by correcting in the condition of scarcely developing the shoulder rollover 25, surface rollover and gradient 27, is formed.;COPYRIGHT: (C)1996,JPO