The invention discloses a cylindrical
forge piece precise mandrel
broaching method and belongs to the field of
hot working of
metal materials. The technical problem that a cylindrical
forge piece cannot be accurately formed in the prior art is solved. The method comprises the steps that
broaching rings are machined and manufactured on the basis that the outer
diameter of each
broaching ring is equal to the sum of the mandrel
diameter and two times of the final wall thickness of the cylindrical
forge piece; a combined mandrel composed of a mandrel, two semi-ring assemblies, two
bushing rings, two broaching ring fastening double-screw bolt sets, N adjusting backing rings and two broaching rings are assembled, and the number of the adjusting backing rings is increased or decreased to enable the distance between the two broaching rings is equal to the
final height of the cylindrical forge piece; the combined mandrel is inserted into an initial blank of the cylindrical forge piece and achieves centering, and the combined mandrel is placed on a mandrel supporter; a pressing
machine with an upper anvil is pressed down, and mandrel broaching is started; the upper anvil is pressed down to the outer side faces of the broaching rings, and broaching is finished. The cylindrical forge piece precise mandrel broaching method is used for cylindrical forge piece broaching, and has the advantages that deformation is uniform and accurate, the force piece core portion is good in tightness, production efficiency is high, and the cost is low.