Forging mold for manufacturing outer race and method for manufacturing outer race by Closed-die hot forging

摘要

PURPOSE: An outer race forming method using hot forging and closed forging and a forging mold for forming an outer race are provided to form a serration unit of a precise shape in spite of clearance formed by a guide post. CONSTITUTION: An outer race forming method using hot forging and closed forging is as follows. A forging material heated and cut at a constant size is up-set by a pressing process. The up-set forging material is closed-forged with a finisher mold set and a plurality of serration units(11) is formed in the outer circumference of the forging material by a plurality of spline grooves being formed in the inner circumference of the finisher mold set and a clearance portion(12) of a predetermined thickness is formed along the upper rim of the forging material. A central part of the forging material is pierced by a trimming mold set. The inner circumference of the pierced forging material is cut so that the inside of the forging material is uniformly formed. One end part of the forging material including the clearance portion is cut to a columnar direction and the rest part of the forging material is cut into several portions to the columnar direction so that a plurality of outer races(10) is formed.