Control arrangement for controllable pneumatic cushions

摘要

The invention relates to a control arrangement for pneumatic cushions, the initially blocked and then damped upward motion of which can be controlled by means of a throttle valve between the oil reservoir and the blocking cylinder. While the aim is to achieve less expensive, more easily modified and more easily automated cushion control, the object resides in the creation of a control arrangement without a mechanical controller. The solution consists in that a programme-controlled comparator (38) based on a microprocessor is supplied with the actual positions of the cushion plate (11) and of the throttle valve (20) and with the actual pressure in the cushion pressure tank (32) by way of measuring sensors (34; 35; 36) and with corresponding tool-dependent desired values (W1 ... W6) by way of an input unit (39). On the output side, the comparator (38) is connected to a cushion-pressure control device (33) and, via a servo valve (42), to an actuating cylinder (25) of the throttle valve (20). The invention is used in mechanical presses, especially in drawing sheet-metal parts. <IMAGE>