METHOD OF MONITORING RAM SPEED OF PRESS BRAKE, PRESS BRAKE USING THE METHOD, AND METHOD AND APPARATUS FOR CONTROLLING RAM POSITION OF PRESS BRAKE

摘要

Position detector means (11) detects the vertical position of a ram (5U) directly, and a first speed computation part (65) determines a first ram speed from the change in the detected position. Simultaneously, a second speed computation part (67) determines a second ram speed from the number of rotations of a servomotor (39) detected by rpm detector means (40). A comparator (69) compares the first ram speed and the second ram speed, and if the difference is greater than a predetermined value, a decision part (71) concludes that trouble has occurred, and suspends the process by stopping the servomotor (39) immediately.