METHOD FOR FORGED-FORMING HELICAL GEAR AND FORGED-FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a method for forged-forming a helical gear and a forged-forming apparatus with which the helical gear having helical teeth of high tooth profile precision can be formed and the service life of a metal mold for tooth mold is extended. SOLUTION: The method for forged-forming the helical gear is composed of; a first process for setting a blank in the inner peripheral side of the tooth mold, in which a formed tooth part for forming the helical teeth in the helical gear is provided in the inner periphery and the larger inner diameter than the outer diameter of the desired helical gear is provided ; a second process for shrinking the diameter in the necessary inner peripheral shape for forming the outer diameter shape of the desired helical gear by loading the tooth mold from the diameter direction into the inner peripheral side; a third process for forming the helical gear formed with the helical teeth by shifting the tooth mold and an upper mold integrally into the reverse upper mold direction with the shrinkage by pressing the tooth mold toward the upper mold; and a fourth process for taking out the helical gear under state of returning back to the size before shrinking the diameter of the tooth mold by releasing the load from the diameter direction to the inner peripheral side loaded on the tooth mold. COPYRIGHT: (C)2006,JPO&NCIPI