Mill stand

Patent metadata

Field	Value
Publication number	US-11801540-B2
Application number	US-202217744789-A
Country	US
Kind code	B2
Filing date	May 16, 2022
Priority date	May 28, 2021
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

A device for stabilizing of working rollers and back-up rollers of a mill stand that has, for each bending block, first hydraulic pressing units being arranged upstream of the working roller, each first hydraulic pressing unit having a piston with a piston rod and a pressure plate, the piston and the piston rod being integrated in the bending block and the pressure plate being pressable against a working roller chock, and for each stand column, at least one second hydraulic pressing unit, the second hydraulic pressing unit being arranged downstream of the back-up roller and having a piston with a piston rod and a pressure plate, the piston and the piston rod being integrated in the stand column and the pressure plate being pressable against the back-up roller chock, and a first hydraulic pressing unit containing a first oscillation absorber.

First claim

The invention claimed is:

1. A mill stand having a device for stabilizing the working rollers and back-up rollers of the mill stand while a rolling stock is being rolled to form a strip, the mill stand comprising:
an upper and a lower working roller for rolling the rolling stock to form the strip,
an upper and a lower back-up roller for supporting the working rollers in the mill stand,
an operator-side and a drive-side mill stand housing,
an operator-side and a drive-side working roller chock, the working rollers being rotatably mounted in the working roller chocks,
operator-side and drive-side bending blocks for deflecting the working rollers,
an operator-side and a drive-side back-up roller chock, the back-up rollers being rotatably mounted in the back-up roller chocks,

wherein,
for each bending block, there are at least two first hydraulic pressing units for stabilizing the working rollers in the mill stand housing, the first hydraulic pressing units being arranged upstream of the working roller in the transport direction of the rolling stock (TR), each first hydraulic pressing unit comprising a piston with a piston rod and a pressure plate, the piston and the piston rod being integrated in the bending block and the pressure plate being able to be pressed hydraulically against a working roller chock;
for each mill stand housing, there is at least one second hydraulic pressing unit for stabilizing the back-up rollers in the mill stand housing, the second hydraulic pressing unit being arranged downstream of the back-up roller in the transport direction of the rolling stock (TR), the second hydraulic pressing unit comprising a piston with a piston rod and a pressure plate, the piston and the piston rod being integrated in the mill stand housing and the pressure plate being able to be pressed hydraulically against the back-up roller chock, at least one of the first hydraulic pressing units contains a first oscillation absorber, which reduces pressure oscillations that occur in a pressure chamber of the at least one first hydraulic pressing unit.

2. The mill stand as claimed in claim 1 , wherein at least one of the second hydraulic pressing units contains a second oscillation absorber, which reduces pressure oscillations that occur in a pressure chamber of the at least one of the second hydraulic pressing unit.

3. The mill stand as claimed in claim 2 , wherein the first or second oscillation absorber is in the form of a Helmholtz resonator having a longitudinal channel forming a hydraulic inductance (L) and a volume forming a hydraulic capacity (C), the pressure chamber of one of the first hydraulic pressing units or the pressure chamber of one of the second hydraulic pressing units being connected to the longitudinal channel and the longitudinal channel being connected to the volume of the Helmholtz resonator.

4. The mill stand as claimed in claim 3 , wherein the longitudinal channel has a settable throttle, with the result that the damping of the first or second oscillation absorber can be set.

5. The mill stand as claimed in claim 2 , wherein the first or second oscillation absorber is in the form of a λ/4 resonator, the pressure chamber of one of the first hydraulic pressing units or the pressure chamber of one of the second hydraulic pressing units being connected to the λ/4 resonator.

6. The mill stand as claimed in claim 2 , wherein the first or second oscillation absorber is in the form of a spring-mass oscillator.

7. The mill stand as claimed in claim 2 , wherein 0.75*fT≤fC≤1.33*fT, wherein fC is a characteristic frequency occurring in the mill stand, and fr is a natural frequency of the first or second oscillation absorber.

8. The rolling stand as claimed in claim 2 , wherein the piston rod of one of the first hydraulic pressing units and/or one of the second hydraulic pressing units has a first longitudinal bore being connected to a piston-side pressure chamber and a second longitudinal bore being connected to a rod-side pressure chamber.

9. The mill stand as claimed in claim 1 , wherein the piston rod of one of the first hydraulic pressing units and/or one of the second hydraulic pressing units has a first longitudinal bore being connected to a piston-side pressure chamber and a second longitudinal bore being connected to a rod-side pressure chamber.

10. The mill stand as claimed in claim 1 , wherein the piston rod of at least one of the first hydraulic pressing units is supported on one of the bending blocks and/or wherein the piston rod of at least one of the second hydraulic pressing units is supported on one of the mill stand housings.

11. A method for stabilizing the working rollers and back-up rollers of a mill stand, while a rolling stock is being rolled to form a strip in the mill stand, in particular by means of a device for stabilizing the working rollers and back-up rollers as claimed in claim 1 , comprising the following method steps:
setting a rolling gap in the vertical direction between the lower and the upper working roller;
stabilizing the working rollers by applying a first hydraulic pressure to the first hydraulic pressing units, the first hydraulic pressing units being pressed against the working roller chocks;
stabilizing the back-up rollers by applying a second hydraulic pressure to the second hydraulic pressing units, the second hydraulic pressing units being pressed against the back-up roller chocks;
absorbing pressure oscillations in a pressure chamber of the first hydraulic pressing units by means of multiple first oscillation absorbers,
absorbing pressure oscillations in a pressure chamber of the second hydraulic pressing unit by means of multiple second oscillation absorbers.

12. The method as claimed in claim 11 , wherein the mill stand carries out three rolling passes in a finishing train and the first oscillation absorbers and a second oscillation absorbers are set to a natural frequency of between f Low and f High

nth rolling pass
f Low [Hz]
f High [Hz]

1
22
40

2
48
87

3
75
133.

13. The method as claimed in claim 12 , wherein a pressing force of at least one of the first hydraulic pressing units during operation is set by way of a pressure regulator with a continuously adjustable valve.

14. The method as claimed in claim 11 , wherein a pressing force of at least one of the first hydraulic pressing units during operation is set by way of a pressure regulator with a continuously adjustable valve.

15. The method as claimed in claim 14 , wherein a pressing force of at least one of the second hydraulic pressing units during operation is set by way of a pressure regulator with a continuously adjustable valve.

16. The method as claimed in cla

Assignees

• Primetals Technologies Austria GmbH

Inventors

• Fürst Heinz
• Glaser Franz Hermann
• Grosseiber Simon
• Keintzel Georg
• Lengauer Thomas
• Seilinger Alois
• Stumbauer Armin

Classifications

• B21B13/22 Primary

  for rolling metal immediately subsequent to continuous casting, {i.e. in-line rolling of steel}(methods therefor B21B1/46; continuous casting B22D11/00, e.g. into moulds with rolls B22D11/06) · CPC title

• B21B31/02 Primary

  Rolling stand frames {or housings}; Roll mountings {; Roll chocks} · CPC title

• B21B31/028 Primary

  Prestressing of rolls or roll mountings in stand frames · CPC title

• B21B31/32

  by liquid pressure {, e.g. hydromechanical adjusting} · CPC title

• B21B1/26

  by hot-rolling {, e.g. Steckel hot mill} · CPC title