Theoretical Analysis of the Design of Mechanical Hammers for High-Velocity Hot Forging

摘要

Mechanical hammers for metal-working operations have a hammer assembly or tup which is accelerated by steam or air pressure or by free fall. At the moment of impact the kinetic energy of a hammer of mass m travelling at velocity sub o will be 1/2mv sub o sq. Ideally, this energy should be completely utilized in deforming the work piece; this would require both the hammer and anvil to be rigid and unyielding, conditions that are closely approached in hot-working operations. However, the effect on the metal being forged is dependent on the relative velocity and displacement at the centre of the tup and anvil. For the purpose of calculating the efficiency, therefore, it is necessary to know firstly the effect of the relative velocity produced by the force acting between the tup and anvil, secondly the ratio of the masses of the tup and anvil, thirdly the spring constant and, finally, the damping coefficient. (Author)