Abstract: Device for the control of the pressure in the pressure chamber for the hydromechanical deep drawing of sheet metal in hydraulic presses wherein the pressure chamber constitutes the drawing die. The control system has at least one two-diametered piston transmitter mounted in a hydraulic cylinder which on the side of the smaller diameter of the piston of the piston transmitter is connected to the space of the pressure chamber and on the other, larger diameter side of the piston transmitter is provided with a supply line for the pressure medium. The control system may include several hydraulic cylinders with two-diameter piston transmitters, the volume of the parallel hydraulic cylinders at the side of the smaller diameters of pistons of the piston transmitters is equal to, or greater than, the volume of the pressing in the pressure chamber.

Abstract: There is disclosed a hydraulic circuit of a press for the hydromechanical drawing of pressings or workpieces in a pressure chamber forming the drawing die which includes at least two spaces for the fluid separated from each other by at least one piston transmitter. At least one of the spaces for the fluid in the pressure chamber separated from the pressure fluid for the forming of the pressing by the piston transmitter is connected by means of a connection branch with a controlled throttle valve with the hydraulic unit of the main working cylinder of the press which drives the drawing punch of the press. To the space for the fluid in the pressure chamber, which is separated by the piston transmitter from the pressure fluid for forming the pressing, is connected a filling branch with a return valve incorporated by means of a hydraulic distributor in the circuit of a hydrogenerator for driving the main working cylinder of the press.