Microprocessor Utilization in Hydraulic Open-Die Forge Press Control

A microprocessor chip is being used to control a 3000 ton open-die forge press with two railbound manipulators for material handling during high-speed forging. The computer controls the dimension of the finished forging to 0.01 inch which necessitates overshoot compensation and per cent correction to prevent undersizing of the workpiece. Control of the manipulators involves rotational control in the continuous rotation and incremental angle rotation modes. The manipulator postion requires integrated control with the press to achieve inches per press stroke while compensating for workpiece length increase due to cross-section area reduction of workpiece. Various sensors, such as pulse tachometers, synchros, etc., are interfaced to the computer while the output is interfaced with relays, solenoids and servo valves as machine control devices. Limit switches and proximity switches are monitored in the interlock circuit. Forging is an ancientart which requires a high level of operator skill. By use of a supervisory computer, the variables of the forging process may be controlled and studied, resulting in forging moving out of the realm of an art and developing into a science with excellent repeatability resulting in uniform metallurgical properties of forged pieces.