Method and apparatus for semiactive reduction of pressure oscillations in a hydraulic system

Abstract

A method and an apparatus for semiactive reduction of pressure oscillations in a hydraulic system of a cold or hot rolling mill or strip handling installation for iron, steel or aluminum materials has the following method steps in the stated sequence: a) detection of a pressure signal by a pressure sensor by permanent measurement of a pressure in the hydraulic system; b) determination of an alternating component of the pressure signal; c) determination of at least one manipulated variable, which varies over time, in real time with the aid of a regulator, taking account of the alternating component; d) application of the manipulated variable to at least one actuator, with the actuator changing a natural frequency of an oscillation damper which is connected to the hydraulic system, and thus reducing an amplitude of the pressure oscillations in the hydraulic system.

1 . A method for semiactive reduction of pressure oscillations in a hydraulic system of a cold or hot rolling mill or strip handling installation for iron, steel or aluminum materials, comprising the following method steps in the stated sequence:
 a) detecting a pressure signal by means of a pressure sensor by permanent measurement of a pressure in the hydraulic system;   b) determining an alternating component of the pressure signal;   c) determining at least one manipulated variable, which varies over time, in real time with the aid of a regulator, taking account of the alternating component;   d) applying the manipulated variable to at least one actuator, with the actuator changing a natural frequency of an oscillation damper which is connected to the hydraulic system, and thus reducing an amplitude of the pressure oscillations in the hydraulic system.   
     
     
         2 . The method according to  claim 1 , wherein the alternating component is subjected to bandpass filtering. 
     
     
         3 . The method according to  claim 1 , wherein the actuator changes a volume in the oscillation damper, which volume corresponds to the manipulated variable. 
     
     
         4 . The method according to  claim 3 , wherein the actuator changes the volume of a Helmholtz resonator or over the active length of a λ/4 resonator. 
     
     
         5 . The method according to  claim 1 , wherein the method is applied to a hydraulic system of a positioning cylinder of a rolling mill stand. 
     
     
         6 . An apparatus for semiactive reduction of pressure oscillations in a hydraulic system of a cold or hot rolling mill or strip handling installation for iron, steel or aluminum materials, having a pressure sensor, which is connected to the hydraulic system, for detection of a pressure signal, an element for determination of an alternating component of the pressure signal, to which the pressure signal can be supplied, at least one regulating apparatus, to which the alternating component can be supplied and with the aid of which at least one manipulated variable can be determined, at least one oscillation damper which is connected to the hydraulic system, and at least one actuator, which is connected to the oscillation damper and has a variable volume, to which the manipulated variable can be supplied and via which a resonator volume of the oscillation damper can be varied. 
     
     
         7 . The apparatus according to  claim 6 , wherein the oscillation damper is in the form of a λ/4 or Helmholtz resonator. 
     
     
         8 . The apparatus according to  claim 6 , wherein the actuator is in the form of an electrical lifting spindle actuator or hydraulic actuator. 
     
     
         9 . The apparatus according to  claim 6 , wherein the apparatus is connected to a hydraulic valve and a hydraulic cylinder of a hydraulic roller positioning means. 
     
     
         10 . The method according to  claim 1 , wherein the method is used for at least one of processing and production of metallic materials or in a composite casting and rolling installation. 
     
     
         11 . The method according to  claim 10 , wherein the composite casting and rolling installation being a thin-strip casting installation or a thin-slab casting installation (ESP). 
     
     
         12 . The method according to  claim 10 , wherein the alternating component is subjected to bandpass filtering. 
     
     
         13 . The method according to  claim 10 , wherein the actuator changes a volume in the oscillation damper, which volume corresponds to the manipulated variable. 
     
     
         14 . The method according to  claim 13 , wherein the actuator changes the volume of a Helmholtz resonator or over the active length of a λ/4 resonator. 
     
     
         15 . The method according to  claim 10 , wherein the method is applied to a hydraulic system of a positioning cylinder of a rolling mill stand. 
     
     
         16 . A method for semiactive reduction of pressure oscillations in a hydraulic system of a cold or hot rolling mill or strip handling installation for iron, steel or aluminum materials, comprising the steps of:
 providing an apparatus for semiactive reduction of pressure oscillations in a hydraulic system of a cold or hot rolling mill or strip handling installation for iron, steel or aluminum materials, having a pressure sensor, which is connected to the hydraulic system, for detection of a pressure signal, an element for determination of an alternating component of the pressure signal, to which the pressure signal can be supplied, at least one regulating apparatus, to which the alternating component can be supplied and with the aid of which at least one manipulated variable can be determined, at least one oscillation damper which is connected to the hydraulic system, and at least one actuator, which is connected to the oscillation damper and has a variable volume, to which the manipulated variable can be supplied and via which a resonator volume of the oscillation damper can be varied; and   using used the apparatus for at least one of processing and production of metallic materials or in a composite casting and rolling installation.   
     
     
         17 . The method according to  claim 16 , wherein the oscillation damper is in the form of a λ/4 or Helmholtz resonator. 
     
     
         18 . The method according to  claim 16 , wherein the actuator is in the form of an electrical lifting spindle actuator or hydraulic actuator. 
     
     
         19 . The method according to  claim 16 , wherein the apparatus is connected to a hydraulic valve and a hydraulic cylinder of a hydraulic roller positioning means. 
     
     
         20 . The method according to  claim 16 , wherein the composite casting and rolling installation being a thin-strip casting installation or a thin-slab casting installation (ESP).