Method of operating a punch press during start-up and stopping

摘要

When starting up the punch press its eccentric shaft must accelerate through a start-up angle from the resting state up to the operating speed of rotation due to the forces of inertia of the moving structures of the punch press. When stopping the punch press the eccentric shaft is rotated in the direction of normal operation into a position between the upper dead center and the lower dead center position, in which latter position no contacting between the upper tool and the metal strip to be worked upon takes place. From this position the eccentric shaft is rotated backwards by the start-up angle into a start-up angle position. In the start-up angle position again no contact between the upper tool and the strip takes place. Accordingly, an enlarged start-up angle which has been increased backwards over the upper dead center position is available for the start-up of the punch press, such that the first punching is executed at the same dynamic conditions of the punch press as the next subsequent punching operations, such that when starting the punch press up precise products are produced already by the first stroke.