Patent · US Expired

Control system for hydraulic power units

US5857333A · kind A · utility

7Cited by

4References

8Claims

0Family size

Assignee

Mannesmann Rexroth AG · DE

Inventors

Stefan Schmidt · Aalen, DE
Michael Reinert · Ruthven, US
Joachim Neumann · Albershausen, DE

Key dates

Filing date	Aug 8, 1997
Grant date	Jan 12, 1999
Priority date	—
Expiry date	Aug 8, 2017

Classification

Technology area (CPC G)Physics
CPC primaryG05D16/2013
WIPO fieldControl
WIPO sectorInstruments

Abstract

The present invention relates to a control system for hydraulic power units, in particular hydraulic cylinder-piston-assemblies comprising a valve to be controlled by an electronic controller, the valve controlling the fluid path between the power unit, a pressure source and a reservoir. A pressure sensor and a circuit for differentiating the sensed pressure quantity in response to time is provided for sensing a respective output variable of the power unit. The pressure variation signal is utilized to assist operating the valve to improve the control operation, i.e. to dampen fluid vibrations or to decrease the hammering noise produced in the operation of stamping, nibbling or shearing machines.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.