U.S. patent application number 10/000843 was filed with the patent office on 2002-06-27 for multi-high roll stand.
Invention is credited to Bunten, Rolf.
Application Number | 20020078729 10/000843 |
Document ID | / |
Family ID | 7662071 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020078729 |
Kind Code |
A1 |
Bunten, Rolf |
June 27, 2002 |
Multi-high roll stand
Abstract
A multi-high roll stand has several driven support rolls and
several working rolls frictionally driven by the support rolls. The
support rolls form a roll gap defining a thickness of rolling stock
guided between the working rolls in a rolling direction. The
working rolls are moveable in a direction substantially parallel to
the rolling direction for adjusting the gap width of the rolling
gap.
Inventors: |
Bunten, Rolf; (Aachen,
DE) |
Correspondence
Address: |
FRIEDRICH KUEFFNER
PATENT AND TRADEMARK ATTORNEY
342 MADISON AVENUE, SUITE 1921
NEW YORK
NY
10173
US
|
Family ID: |
7662071 |
Appl. No.: |
10/000843 |
Filed: |
November 1, 2001 |
Current U.S.
Class: |
72/241.2 |
Current CPC
Class: |
B21B 2013/025 20130101;
B21B 37/62 20130101; B21B 31/20 20130101; B21B 37/165 20130101;
B21B 2001/228 20130101; B21B 2031/206 20130101 |
Class at
Publication: |
72/241.2 |
International
Class: |
B21B 013/14 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 3, 2000 |
DE |
100 54 580.7 |
Claims
What is claimed is:
1. A multi-high roll stand having several driven support rolls and
having several working rolls frictionally driven by the support
rolls, wherein the support rolls form a roll gap defining a
thickness of rolling stock guided between the working rolls in a
rolling direction, wherein the working rolls are configured to be
moveable in a direction substantially parallel to the rolling
direction for adjusting a gap width of the rolling gap.
2. The multi-high roll stand according to claim 1, wherein the
working rolls are substantially horizontally movable for adjusting
the gap width of the rolling gap.
3. The multi-high roll stand according to claim 1, wherein the
working rolls have an adjusting device, respectively, wherein the
adjusting devices of the working rolls are configured to adjust a
position of the working rolls in the rolling direction, wherein the
multi-high roll stand further comprises a common control device
connected to the adjusting devices, wherein the common control
device provides a set value for each one of the adjusting devices
as a function of a measured value of a thickness of the rolling
stock and as a function of the preset value for the thickness of
the rolling stock.
4. The multi-high roll stand according to claim 3, wherein the
adjusting devices acting on the working rolls are hydraulic
adjusting devices.
5. The multi-high roll stand according to claim 3, further
comprising a measurement transducer connected to an input of the
common control device.
6. The multi-high roll stand according to claim 3, wherein the
common control device has a memory component configured to store
several nominal preset values for the thickness of the rolling
stock.
7. A method for operating a multi-high roll stand according to
claim 1, comprising the step of adjusting a thickness of the
rolling stock by moving the working rolls in a direction
substantially parallel to the rolling direction.
8. The method according to claim 7, further comprising the steps of
comparing an actual measured value of the thickness of the rolling
stock with a nominal value of the thickness of the rolling stock
and using a result of the step of comparing in the step of
adjusting.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a multi-high roll stand with a
plurality of driven support rolls and with a number of working
rolls frictionally driven by the support rolls, wherein the working
rolls form a rolling gap which defines the thickness of rolling
stock guided between the working rolls in a rolling direction.
[0003] 2. Description of the Related Art
[0004] For rolling a rolling stock, for example, in a rolling mill,
a roll stand can be used. The roll stand is often a so-called
multi-high roll stand and comprises a plurality of working rolls
and a number of support rolls. The support rolls are conventionally
driven by a correlated drive wherein each support roll is in
frictional contact with a correlated working roll. By means of the
thus provided frictional drive action, each working roll is then
driven by the correlated support roll. The working rolls act
together onto opposed sides of the rolling stock wherein the
thickness of the rolling stock, guided between the working rolls
through the multi-high roll stand, is determined by the roll gap
formed between the working rolls. The thickness of the rolling
stock guided through the multi-high roll stand can be adjusted by
means of a corresponding variation of the pressing force, which is
also referred to as rolling force, of each working roll.
[0005] When processing comparatively high-quality rolling stock
such as, for example, steel or stainless steel, it may be
important, in particular, for the so-called skin pass rolling step
of such a rolling stock, that the respective multi-high roll stand
is configured for covering a comparatively wide rolling force
range. A control provided for this purpose, by which, inter alia,
the thickness of the rolling stock is adjusted, thus covers with
its value range also a comparatively large rolling force range.
However, for such a system the essential components are
conventionally configured such that measuring errors, such as, for
example, errors in the rolling force measurement, depend on the
maximum value of the respective measured value. In particular in
the case of a rolling force measurement, whose value range covers a
comparatively wide rolling force range, the absolute measuring
error is thus comparatively large.
[0006] On the other hand, in the so-called skin pass rolling of IF
(interstitial free) steel, it is necessary to adjust, even for such
multi-high roll stands, comparatively small rolling forces.
Accordingly, for a multi-high roll stand, which is to be used, on
the one hand, for skin pass rolling of IF steel and, on the other
hand, for covering a generally comparatively large rolling force
range, the measuring error for determining the rolling force can be
greater than the actual rolling force required for skin pass
rolling of IF steel. The thickness and/or skin pass rolling control
for such a multi-high roll stand is thus comparatively
imprecise.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a
multi-high roll stand of the aforementioned kind which, on the one
hand, can be used for a comparatively high rolling force range and,
on the other hand, can be adjusted especially precisely, even for
comparatively small rolling forces, with respect to its roll gap
and thus with respect to the thickness of the rolling stock.
Moreover, a method for operating such a multi-high roll stand is to
be provided which makes possible, even for comparatively small
rolling forces, a particularly precise thickness control of the
rolling stock.
[0008] In accordance with the present invention, this is achieved
in regard to the multi-high roll stand in that the working rolls
are movable in a direction substantially parallel to the rolling
direction for adjusting the gap width of the roll gap.
[0009] The invention in this connection is based on the
consideration that the thickness adjustment of the rolling stock
can be realized with an especially high precision in that it is
carried out via an adjusting parameter having a comparatively large
adjusting stroke. The actual adjusting parameter for the thickness
adjustment, i.e., the position of the respective working roll
perpendicularly to the rolling direction for forming the roll gap,
however, has a comparatively minimal stroke adjustment. It is
therefore transformed into a parameter with comparatively large
adjusting stroke, i.e., the position of the working roll in a
direction parallel to the rolling direction. When adjustments are
carried out, the working roll rolls on the surface of the spatially
stationary support roll so that a defined relation between the
position of the working roll perpendicularly to the rolling
direction and its position in the rolling direction results. In
particular in this area directly below the support roll the
geometric conditions are such that a comparatively generous spatial
movement of the working roll in the rolling direction results in
only a minimal change of its position in the direction
perpendicularly to the rolling direction.
[0010] Conventionally, a rolling mill is configured for passing the
rolling stock therethrough substantially in a horizontal rolling
direction. Advantageously, in an adaptation to this configuration,
the working rolls are accordingly movable substantially
horizontally for adjusting the gap width of the roll gap.
[0011] For a particularly reliable automated thickness adjustment
of the rolling stock, a control device is correlated advantageously
with the multi-high roll stand. It is expediently connected at the
output side with a number of adjusting devices, each one being
correlated with a working roll, respectively, for adjusting the
position of the working roll in the rolling direction. The control
device presets in this connection a nominal or preset adjusting
value for each adjusting device, respectively, for positioning the
respective working roll in the rolling direction wherein the
respective adjusting value is selected as a function of a measured
actual value of the thickness of the rolling stock.
[0012] For the adjusting devices acting on the working rolls
different configurations can be provided, for example, in the form
of rotary spindles. Advantageously, the adjusting devices are,
however, hydraulic adjusting devices with which an specially high
adjusting precision can be obtained.
[0013] For a timely and particularly reactive control, a direct
loading of the control device with a measured value characteristic
of the thickness of the rolling stock is advantageously provided.
For this purpose, the inlet side of the common control device is
advantageously connected with a measured value (measurement)
transponder for determining the thickness of the rolling stock.
[0014] In order to be able to have available in the way of a
selectable rolling program a suitable pre-defined operating
parameter for a plurality of different purposes, according to a
further expedient embodiment a memory component is correlated with
the common control device in which a number of nominal values for
the thickness of the rolling stock can be stored. As a function of
the actual use of the roll stand, it is possible in a very simple
way to switch between different rolling programs in that a new
currently desired valid nominal value for the thickness of the
rolling stock is selected, respectively, from the nominal values
stored in the memory component.
[0015] With respect to the method for operating a multi-high roll
stand, the object is solved in that the thickness of the rolling
stock is adjusted by a movement of the working rolls in a direction
which is substantially parallel to the rolling direction.
[0016] The adjustment of the position of the working rolls in the
rolling direction is advantageously performed by means of a
comparison of a currently determined value of the thickness of the
rolling stock with the nominal value for the thickness of the
rolling stock.
[0017] The advantages obtained with the invention reside in
particular in that by the movement of the working rolls in the
rolling direction for the purpose of adjusting the gap width of the
roll gap the thickness of the rolling stock is affected indirectly
and by means of a control parameter with a comparatively large
adjusting stroke. In particular as a result of the geometric
conditions between the support rolls and the working rolls, the
displacement strokes of the working rolls, i.e., the positional
changes required for obtaining a predetermined change in the gap
width of the roll gap, are especially large so that the sensitivity
and precision for adjusting the gap width of the roll gap are
particularly high. Moreover, the position adjustment of the working
rolls in a direction substantially perpendicular to the rolling
force is such that a coupling to the rolling force is realized only
by the deflection within the working roll itself. Moreover, for
such an adjustment of the gap width of the roll gap the stand
friction is especially minimal.
BRIEF DESCRIPTION OF THE DRAWING
[0018] One embodiment of the invention will be explained in the
following with the aid of the only drawing FIGURE showing a
multi-high roll stand.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The FIGURE shows a multi-high roll stand 1 as a four-high
stand and comprises an upper working roll and a lower working roll
2, 4 which are supported substantially vertically on a support roll
6, 8, respectively. The working rolls 2, 4 are correlated with roll
bending devices, not illustrated in detail, which load the working
rolls 2, 4 with vertical roll bending forces for adjusting the
rolling profile.
[0020] The support rolls 6, 8 are driven by a drive, not
illustrated in detail, receptively, and are rotated about their
central axis. Each working roll 2, 4 is in frictional contact with
the respectively correlated support roll 6, 8 so that it is
entrained by the respective correlated driven support roll 6, 8 by
friction.
[0021] Rolling stock 10 is guided between the working rolls 2, 4 in
a substantially horizontal rolling direction x, as indicated by the
arrow. The working rolls 2, 4 form a roll gap 12 in a direction
substantially perpendicular to the rolling direction x which roll
gap determines the thickness of the rolling stock 10 leaving the
multi-high roll stand 1.
[0022] The multi-high roll stand 1, on the one hand, is configured
for loading the rolling stock 10 by means of a rolling force, that
is substantially oriented perpendicularly to the rolling direction
x, across a comparatively large rolling force area. In this
connection, by means of an adjusting device, not illustrated in
detail, the rolling force is adjustable at the support rolls 6, 8
and is transmitted by means of the working rolls 2, 4 onto the
rolling stock 10. The multi-high roll stand 1 is configured for
comparatively minimal rolling forces, as they are required, for
example, for skin pass rolling of IF steels, as well as for
comparatively high rolling forces and is thus particularly flexible
with regard to its use.
[0023] On the other hand, the multi-high roll stands
1--particularly for comparatively small rolling forces--is
configured for an especially precise adjustment of the thickness of
the rolling stock 10. For this purpose, a control device 20 is
correlated with the multi-high roll stand 1 via which the working
rolls 2, 4, for the adjustment of the gap width of the roll gap 12,
are movable in a direction substantially parallel to the rolling
direction. For this purpose, each working roll 2, 4 is moveably
supported at its ends in a direction parallel to the rolling
direction x. Moreover, each working roll 2, 4 has correlated
therewith an adjusting system 22 or 24. The adjusting system 22
correlated with the working roll 2 comprises in this connection a
hydraulically actuated adjusting piston 26 which is loadable by
means of an adjusting device 28 configured as a pressure
transponder with an adjusting pressure. In analogy, the adjusting
system 24 correlated with the second working roll 4 comprises an
adjusting piston 30 which is loadable by means of an adjusting
device 32 in the form of a pressure transponder with adjusting
pressure.
[0024] For adjusting the position of each working roll 2, 4 in the
rolling direction x, the output side of the control device is
connected by data lines 34, 36 to the adjusting device 28, 32. By
means of the data lines 34, 36 the common control device presets an
adjusting value S in the adjusting devices 28, 32, respectively,
and, by means of theses values S, the adjustment of an adjusting
pressure is realized via the respective adjusting device 28 or 32;
the adjusting pressure, in turn, determines the respective position
of the working roll 2 or 4 in the rolling direction X.
[0025] The common control device 20 is configured for readjusting
the position adjustment of the working rolls 2, 4 in the rolling
direction x as a function of the thickness of the rolling stock 10.
For this purpose, the input side of the common control device 20 is
connected by means of the data line 40 with a measured value
(measurement) transponder 42, configured to determine the thickness
of the rolling stock 10. The common control device readjusts by
means of the adjusting values S the positions of the working rolls
2, 4 in the rolling direction X until the thickness of the rolling
stock 10 measured by the measured value transponder 42 corresponds
to a nominal (preset) value Sw. The nominal value Sw, as a function
of a predetermined use, can be selected from a plurality of nominal
values Sw provided in a data memory system 44 connected to the
common control device 20.
[0026] As a result of the continuously maintained contact provided
by the rolling force between each working roll 2, 4 and the
correlated support roll 6, 8, the respective working roll 2, 4
rolls on the surface of the support roll 6, 8 correlated therewith.
As a result of these boundary conditions, the movement of the
respective working roll 2, 4 in a direction parallel to the rolling
direction x results also in a change of the position of the
respective working roll 2, 4 in a direction perpendicularly to the
rolling direction x and thus in a change of the gap width of the
roll gap 12. As a result of the geometric conditions with regard to
the arrangement of the working rolls 2, 4 substantially centrally
between the support rolls 6, 8, a comparatively generous spatial
movement of the working rolls 2, 4 in a direction parallel to the
rolling direction x causes only a minimal change of their position
in a direction perpendicular to the rolling direction x.
Accordingly, across a comparatively large adjusting stroke in the
direction parallel to the rolling direction x, a comparatively
minimal and thus high-resolution change of the gap width of the
roll gap 12 can be obtained. Accordingly, the control of the
adjustment of the roll gap 12 is of relatively high precision even
for comparatively minimal rolling forces.
[0027] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
* * * * *