Method of self-regulating consistency of applied energy in a forging hammer employing input differential

摘要

A forging hammer employs compressible fluid to drive the ram into impact and a trapped volume of compressible fluid to cause the ram to be retracted from impact position when fluid driving the ram into impact is released. The velocity of impact is adjusted by the timing of the opening of a valve allowing variable amounts of compressible fluid into a cylinder from a compressible fluid supply. Pressure sensing means is provided to sense the pressure of the lifting fluid, calculating means for calculating kinetic energy from the rate of change of lifting air pressure, comparator means for comparing kinetic energy with a standard and a counter for accumulating error. Sensing the rate of change of pressure of the lifting fluid permits calculation of the velocity of the hammer. Kinetic energy at the time of impact is calculated from the velocity and the mass of the ram assembly. The calculated kinetic energy is compared with the preselected kinetic energy requirement for the next blow and, if there is an error, the counter is incremented or decremented until the error reaches a predetermined minimum size. Upon reaching the predetermined minimum size, the timing of the valve means in the direction to correct or minimize the error is accomplished.