Vertical presses

High flexibility with the hydraulic circuit press

In this article we take into consideration the realization of a vertical press with hydraulic control for hot deformation or deep drawing.

In this specific case the press with a four-column frame applies a “classic” hydraulic circuit which is commonly used in the heavy deformation sector.

The power section consists of two piston pumps with constant power and proportional variable displacement; each pump is driven by a 110 kW motor.

Such a control allows a high programming flexibility combined with a rational exploitation of the available power. Several speeds and powers can be programmed during the different cycle phases.

The moving table is driven by two double acting cylinders allowing a fast approach and return together with an increase of the pushing phase during the pressing procedure supported by the main plunging cylinder.

The main block uses both monitored control valves and logic elements for the control of the different cycle phases: from the fast adjustable down movement to the selection of the pressing procedure at different speeds, from the controlled pressure decrease to the return.

The pressing force is detected by a pressure transducer and is displayed on the machine control panel.

The safety blocks with monitored logic elements are installed on the lower chambers of the approaching cylinders (they are directly flanged on the ports).

The technical features of this circuit are:
■ approaching speed: 300 mm/sec
■ adjustable pressing speed: from 9 to 40 mm/sec
■ return speed: 350 mm/sec
■ pressing force: 20000 kN