Changing the effective contour of a running surface of a working roll during hot rolling of rolling stock in a roll stand to form a rolled strip

Patent metadata

Field	Value
Publication number	US-11919059-B2
Application number	US-202017310246-A
Country	US
Kind code	B2
Filing date	Jan 13, 2020
Priority date	Jan 28, 2019
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

The present invention relates to a method and an apparatus for changing the effective contour of a running surface ( 8 ) of a working roller ( 3, 4 ) during the hot rolling of rolling stock in a roll stand ( 2 ) to form a rolled strip ( 1 ). The intention is to be able to change the contour of the running surface ( 8 ) during the hot rolling by means of the invention. This object is achieved according to the invention by the axial displacement of the working rollers ( 3, 4 ) in opposite directions by a displacement distance s, wherein s is greater or less than
Δ ⁢ ⁢ r tan ⁢ ⁢ ( α )
and Δr indicates the wear of the running surface ( 8 ) in the radial direction (R) and α indicates the pitch angle of the conical portion ( 7 ) of the respective working roller ( 3, 4 ).

First claim

The invention claimed is:

1. A method for reducing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:
an upper working roller and a lower working roller, wherein each working roller has two ends for rotational mounting of the working roller in chocks,
wherein in an axial direction, each working roller in the roll stand extending in respective opposite directions has a conical portion followed by a running surface;
wherein running surfaces of each of the working rollers in the roll stand have a non-cylindrical initial contour prior to the hot rolling;
wherein in the roll stand, the upper working roller is fitted in the opposite direction to the lower working roller;
wherein each working roller has a respective displacing device operable for axially displacing the working rollers in the roll stand in respective opposite directions;
comprising the method steps of:
hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases by Δr during the rolling; and
reducing the effective contour of the running surfaces of the working rollers during hot rolling of rolling stock by axially displacing the working rollers in opposite axial directions by a displacement distance

s
>

Δ
⁢

⁢
r

tan
⁢

⁢

(
α
)

,

 where Δr indicates wearing of the running surface in a radial direction, and α indicates a pitch angle of the conical portion of the respective working roller, wherein the effective contour of the running surface of each working roller is the contour that the running surface of the working roller (which is not axially displaced during the hot rolling) would have to have so that a determined profile or a determined planarity for the rolled strip is produced during the hot rolling of rolling stock.

2. The method as claimed in claim 1 , wherein, for very thin strips having a thickness of between 0.5 and 2 mm, the planarity of the strip is set.

3. The method as claimed in claim 1 , wherein, for strips having a thickness of >2 mm, the profile of the strip is set.

4. A method for reducing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:
an upper working roller and a lower working roller, wherein each working roller has two ends for the rotational mounting of the working roller in chocks;
wherein in the axial direction, each working roller in the roll stand extending in respective opposite directions has a conical portion followed by a running surface;
wherein running surfaces of each of the working rollers in the roll stand have a non-cylindrical initial contour prior to the hot rolling;
wherein in the roll stand, the upper working roller is fitted in the opposite direction to the lower working roller;
wherein each working roller has a respective displacing device operable for axially displacing the working rollers in the roll stand in respective opposite directions;
comprising the method steps of:
hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases at a rate of {dot over (Δ)}r during the rolling; and
reducing the effective contour of the running surfaces of the working rollers during hot rolling of rolling stock by axially displacing the working rollers in opposite axial directions at a displacement rate of

v
≡

s
.

>

Δ
⁢

⁢

r
.

tan
⁢

⁢

(
α
)

,

 where {dot over (Δ)}r indicates me rate of wear of the running surface in the radial direction (R) and α indicates the pitch angle of the conical portion of the respective working roller, wherein the effective contour of the running surface of each working roller is the contour that the running surface of the working roller (which is not axially displaced during the hot rolling) would have to have so that a determined profile or a determined planarity for the rolled strip is produced during the hot rolling of rolling stock.

5. The method as claimed in claim 4 , wherein for very thin strips having a thickness of between 0.5 and 2 mm, the planarity of the strip is set.

6. The method as claimed in claim 4 , wherein for strips having a thickness of >2 mm, the profile of the strip is set.

7. A method for increasing an effective contour of a running surface of a working roller during hot rolling of rolling stock in a roll stand to form a rolled strip, wherein the roll stand comprises:
an upper working roller and a lower working roller, wherein each working roller has two ends for the rotational mounting of the working roller in chocks;
wherein in an axial direction, each working roller in the roll stand in respective opposite directions has a conical portion followed by a running surface;
wherein running surfaces of each of the working rollers in the roll stand have a non-cylindrical initial contour prior to the hot rolling;
wherein in the roll stand, the upper working roller is fitted in the opposite direction to the lower working roller;
wherein each working roller has a respective displacing device operable for axially displacing the working rollers in the roll stand in respective opposite directions;
comprising the method steps of:
hot rolling of the rolling stock between the two working rollers, wherein the radial extent of the running surface of a working roller decreases by Δr during the rolling; and
increasing the effective contour of the running surfaces of the working rollers by axially displacing the working rollers in opposite axial directions by a displacement distance

0
<
s
<

Δ
⁢

⁢
r

tan
⁢

Assignees

• Primetals Technologies Germany Gmbh

Inventors

• Dagner Johannes

Classifications

• B21B13/142 Primary

  by axially shifting the rolls, e.g. rolls with tapered ends or with a curved contour for continuously-variable crown CVC · CPC title

• B21B1/22

  for rolling {plates, strips,} bands or sheets of indefinite length (B21B1/42 takes precedence) · CPC title

• B21B27/021

  Rolls for sheets or strips · CPC title

• B21B2001/225

  by hot-rolling · CPC title

• B21B2027/022

  Rolls having tapered ends · CPC title