Hydraulic forming machine for pressing workpieces, in particular forging hammer, and method for operating a hydraulic forming machine, in particular a forging hammer

A forging hammer for workpiece forming, comprising:

• a hydraulic cylinder for driving a ram configured for workpiece forming, which ram is mechanically coupled to the hydraulic cylinder, and a hydraulic circuit configured to operate the hydraulic cylinder and having an actuator for setting a volume flow of hydraulic fluid for filling a first hydraulic working chamber of the hydraulic cylinder during the execution of a working stroke (A) immediately preceding the workpiece forming, with an acceleration phase for accelerating the ram to a setpoint speed (Vsoll), and a movement phase which follows the acceleration phase and in which the setpoint speed (Vsoll) is substantially maintained,
• wherein the hydraulic circuit and the actuator are configured to:
• adjust and vary the volume flow in the acceleration phase as a function of the setpoint speed (Vsoll) such that the setpoint speed (Vsoll) is reached, and
• reduce the volume flow in the subsequent movement phase to a post-flow volume flow, in such a way that a hydraulic pressure prevailing in the movement phase in the first hydraulic working chamber is substantially above a cavitation pressure of the hydraulic fluid,
• wherein the hydraulic circuit is further configured to adjust and vary the volume flow in such a way that the volume flow in the acceleration phase is adjusted in such a way that the movement phase corresponds to a range of 10% to 30% of the stroke of the hydraulic cylinder.