LOGIC AND METHOD OF SAFETY IN CONTROLLING A POWER PRESS

The Ministry of Labor in Japan has established a standard for the mech anical structure of power presses. The standard stipulates that the po wer press be equipped with an overrun monitor function that enables th e slide to be forcibly stopped when the slide fails to stop within a s pecified 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 fun ction 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.