Logic and Method of Safety in Controlling a Power Press

Abstract

The Ministry of Labor in Japan has established a standard for the mechanical structure of power presses. The standard stipulates that the power press be equipped with an overrun monitor function that enables the slide to be forcibly stopped when the slide fails to stop within a specified allowable range around the top dead center. The operation of the power press is considered to be a man-machine system in which both the operator and the machine may make errors. The overrun monitor function is defined as a requirement for safe operation of the system. A signal processing method is established for fail-safe operation of the overrun monitor function. A fail-safe overrun monitor system based on the signal processing method is presented.