Hoerbiger Automatisierungstechnik Holding Gmbh

Hygrama Ag

Hoerbiger Automatierungstechnik Holding Gmbh

Hawe Altenstadt Holding Gmbh

Bernhard Russ

Martin Rauwolf

Manfred Kurz

Andreas Socher

Günther Strasser

Roland Thurner

Rainer Teltscher

Ilker Oezcanoglu

Erich Dörfler

An electrohydraulic drive unit of a machine tool having a tool that can be moved up and down is provided and comprises a double-acting hydraulic cylinder-piston arrangement oriented in upright manner and having a piston projecting downwardly from the cylinder and being coupled with the tool, a valve block flanged to the cylinder at the upper end region thereof and having a servo suction valve, a hydraulic-fluid reservoir flanged to the valve block at a first hydraulic interface and a motor-pump unit having an electric motor and a hydraulic pump driven thereby and flanged to the valve block at a second hydraulic interface. A suction line, extends from the first hydraulic interface to the second hydraulic interface through the valve block.

Machine tool

The hydraulic drive system of a machine press comprises at least two independent hydraulic drive units. In each of said hydraulic drive units at least one hydraulic cylinder, which is connected via valves and a main pressure line under supply pressure to a pump driven by a motor, raises and lowers the upper tool carrier. The rotational speed of the motor is adjustable via the numeric machine control, in which a rotational speed profile defined across the work cycle is stored. Furthermore, a pressure-limiting unit limiting the level of the supply pressure is provided, which at least during a part of the work cycle limits the supply pressure to the lower pressure of a pressure profile defined across the work cycle and stored in the numeric machine control and the actual load pressure increased by an extra amount at the at least one hydraulic cylinder.

Machine press

In a machine press having a lower and an upper tool carrier, a hydraulic drive acting on the upper tool carrier comprises at least one closed hydraulic drive system that can be switched between rapid motion and press motion, the drive system having at least one hydraulic cylinder piston unit. The hydraulic liquid of the at least one hydraulic drive system is stored in a pressure accumulator fanning the storage container, supplying the entire associated hydraulic drive system. permanently with at least a base pressure above the ambient pressure. There is no hydraulic connection whatsoever between the working chamber on the piston rod side and the working chamber on the piston side of at least one hydraulic cylinder piston unit. The upper tool carrier is pre-stressed into its upper position by a spring unit.

Valve with a displaceable actuating device that controls the movements of at least one actual sealing element for opening and closing, and the actuating device is loaded with an elastic element essentially in a perpendicular direction relative to the direction of displacement, and the longitudinal axis of the actuating device and the force exercised by the elastic element are aligned in one position of the actuating device between its two extreme positions. In order to realize a valve that can be electrically switched using minimal currents and that is characterized, in particular, by its small construction size but that is still able to achieve large regulating distances, the actuating device is a unilaterally constrained piezoelectric bending element.

Valve with unilaterally constrained piezoelectric bending element as actuating device

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Peiting, Germany

Bernhard Russ