Repeated upset forging of metal rings from solid bar - where bar is upset to form head, which is pierced by punch and simultaneously sheared from bar before repeating process

摘要

A solid rod is placed in a die so its projecting end can be upset by a second die (b) to form a solid head on the bar. A shearing punch is then driven through die (b) to convert the solid head into a ring which is also sheared off the remaining bar, so the latter is reduced in length. The short length of bar is then subjected to the same sequence of forging operations until a second ring is obtd. This process is repeated, so that many rings can be obtd. from a single bar, the length of the latter being progressively reduced. The outer dia. of the bar corresponds with the bore of the rings. The initial solid bar is pref. round, oval or polygonal; and may be preheated before forging. External or internal gear teeth may also be forged into the rings. A conventional process involves the blanking of rings from solid disks, so the central zone of each disk becomes scrap, thus wasting valuable raw material. The invention reduces the amt. of material required, thus decreasing mfg. costs.