U.S. patent application number 09/738866 was filed with the patent office on 2001-09-13 for calibration method for a universal roll stand.
Invention is credited to Hartmann, Ralf, Minnerop, Michael.
Application Number | 20010020378 09/738866 |
Document ID | / |
Family ID | 7935170 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010020378 |
Kind Code |
A1 |
Hartmann, Ralf ; et
al. |
September 13, 2001 |
Calibration method for a universal roll stand
Abstract
In a calibration method for a universal roll stand with
horizontal rolls and vertical rolls, wherein the horizontal rolls
are supported in upper and lower horizontal chocks and the vertical
rolls are supported in vertical chocks and wherein the horizontal
rolls are configured to be screwed down on one another and the
vertical rolls are configured to be screwed down on the horizontal
rolls, the vertical chocks are moved between the horizontal chocks
such that vertical roll gaps remain between the horizontal rolls
and the vertical rolls. Subsequently, spacers are arranged between
the vertical chocks and at least one of the upper and the lower
horizontal chocks. The horizontal chocks are advanced toward one
another until the horizontal chocks contact the vertical chocks or
the spacers, wherein the horizontal chocks during advancing are
loaded maximally with an advancing force. The horizontal chocks are
loaded after completion of advancing with a calibration force which
is greater than the advancing force. After loading with the
calibration force, the reached positional values of the horizontal
chocks are measured and reference positions for subsequent rolling
processes are determined based on the reached position values.
Inventors: |
Hartmann, Ralf; (Dusseldorf,
DE) ; Minnerop, Michael; (Ratingen, DE) |
Correspondence
Address: |
Friedrich Kueffner
Suite 1921
342 Madison Avenue
New York
NY
10173
US
|
Family ID: |
7935170 |
Appl. No.: |
09/738866 |
Filed: |
December 15, 2000 |
Current U.S.
Class: |
72/225 |
Current CPC
Class: |
B21B 2203/36 20130101;
B21B 38/105 20130101; B21B 2013/106 20130101; B21B 31/32 20130101;
B21B 2273/22 20130101 |
Class at
Publication: |
72/225 |
International
Class: |
B21B 013/10 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 30, 1999 |
DE |
199 64 042.4 |
Claims
What is claimed is:
1. A calibration method for a universal roll stand with horizontal
rolls and vertical rolls, wherein the horizontal rolls are
supported in upper and lower horizontal chocks and wherein the
vertical rolls are supported in vertical chocks, wherein the
horizontal rolls are configured to be screwed down on one another
and wherein the vertical rolls are configured to be screwed down on
the horizontal rolls; the method comprising the steps: moving the
vertical chocks between the horizontal chocks such that vertical
roll gaps remain between the horizontal rolls and the vertical
rolls; arranging spacers between the vertical chocks and at least
one of the upper and the lower horizontal chocks; advancing the
horizontal chocks toward one another until the horizontal chocks
contact the vertical chocks or the spacers, wherein the horizontal
chocks during advancing are loaded maximally with an advancing
force; loading the horizontal chocks after completion of advancing
with a calibration force which is greater than the advancing force;
and, after loading with the calibration force, measuring the
reached position values of the horizontal chocks and determining,
based on the reached position values, reference positions for
subsequent rolling processes.
2. The method according to claim 1, wherein the step of advancing
the horizontal chocks is carried out by position control.
3. The method according to claim 1, further comprising the steps of
pre-setting nominal end position values in the control elements for
the horizontal chocks and selecting the nominal end position values
such that the horizontal chocks, before reaching the nominal end
position values, have contacted the vertical chocks or the spacers
with certainty.
4. The method according to claim 3, further comprising the steps of
preventing further method steps from being carried subsequent to
the step of advancing and issuing an error communication when the
nominal end position values for the horizontal chocks have been
reached.
5. The method according to claim 1, wherein the step of advancing
the horizontal chocks comprises two partial advancing steps, the
method further comprising the step of measuring forces present in
the control elements for the horizontal chocks between the partial
advancing steps.
6. The method according to claim 1, wherein the horizontal chocks
are advanced successively against the vertical chocks or the
spacers.
7. the method according to claim 1, wherein the horizontal chocks
are advanced simultaneously against the vertical chocks or the
spacers.
8. The method according to claim 1, wherein loading of the
horizontal chocks with the calibration force is carried out by
force control.
9. The method according to claim 1, wherein at least the horizontal
chocks are configured to be hydraulically advanced.
10. The method according to claim 1, wherein the vertical chocks
are configured to be hydraulically advanced.
11. The method according to claim 1, wherein the calibration force
is smaller than a rolling force to be applied in the subsequent
rolling processes.
12. The method according to claim 1, wherein the horizontal chocks
and the vertical chocks are moved apart by position control after
measuring the reached position values.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a calibration method for a
universal roll stand with horizontal rolls and vertical rolls,
wherein the horizontal rolls are supported in upper and lower
horizontal chocks and wherein the vertical rolls are supported in
vertical chocks. The horizontal rolls can be screwed down against
one another, and the vertical rolls can be a screwed down against
the horizontal rolls.
[0003] 2. Description of the Related Art
[0004] Such calibration methods are known in general. For example,
the patent documents DE 35 01 622 C2, EP 0 483 939 B1, and EP 0 275
875 B1 disclose such methods.
[0005] According to DE 35 01 622 C2 an axial adjustment of the
horizontal rolls is performed. This document discloses moreover a
method for vertical adjustment of the horizontal rolls. However,
the method described herein requires that the rolls are
conical.
[0006] According to the method of EP 0 483 939 B1, the horizontal
rolls are aligned parallel and horizontally to one another. A
method for a vertical adjustment of the horizontal rolls is not
disclosed.
[0007] According to the method of EP 0 275 875 B1, the rolls are
moved by an electromechanical coarse adjusting device in the
universal roll stand to a roll gap zero or to a defined roll gap by
means of calibration pieces. By means of a hydraulic fine
adjustment, the stand and adjusting parts positioned within the
horizontal as well as vertical force flux are subjected by a
pressure increase in the adjusting cylinders to a compressive
strain which corresponds to an average theoretical expected rolling
force of the pass schedule. The precise sequence of calibration and
the arrangement of the calibration pieces is not disclosed in this
document.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a
calibration method for a universal roll stand with horizontal and
vertical rolls in which the horizontal rolls can be positioned
precisely relative to the vertical rolls independent of the shape
of the rolls.
[0009] In accordance with the present invention, this is achieved
by the following method steps:
[0010] the vertical chocks are moved between the horizontal chocks
such that vertical roll gaps remain between the horizontal rolls
and the vertical rolls;
[0011] spacer elements are arranged between the vertical chocks, on
the one hand, and the upper and/or the lower horizontal chocks, on
the other hand;
[0012] the horizontal chocks are advanced toward one another until
they rest against the vertical chocks or the spacer elements,
wherein the horizontal chocks during advancing are loaded maximally
with an advancing force;
[0013] the horizontal chocks are loaded after completion of
advancing with a calibration force which is greater than the
advancing force; and,
[0014] after loading with the calibration force, the reached
position values of the horizontal chocks are measured and reference
positions are determined, based on the reached position values, for
the subsequent rolling processes.
[0015] When advancing of the horizontal chocks is controlled by
position control, the calibration method is especially functionally
reliable.
[0016] When nominal end position values are preset in the control
elements for the horizontal chocks, wherein the nominal end
position values are selected such that the horizontal chocks,
before reaching the nominal end position values, have contacted the
vertical chocks or the spacer elements with certainty, it is always
possible to perform the calibration method.
[0017] When, upon reaching the nominal end position values, the
method steps that are to follow the advancement of the horizontal
chocks are not performed and an error communication is issued,
errors can be easily detected.
[0018] When the advancement of the horizontal chocks is carried out
in two partial advancing steps and between the partial advancing
steps forces are measured that occur in the non-rolling state
within the control elements for the horizontal chocks, these forces
are available for subsequent rolling processes as correction or
offset values for loading the control elements.
[0019] It is also possible, if desired, to advance the horizontal
chocks successively or simultaneously against the vertical chocks
or the spacer elements.
[0020] When loading of the horizontal chocks with the calibration
force is force-controlled, a force compensation can be carried out
between the horizontal chocks.
[0021] When at least the horizontal chocks, preferably also the
vertical chocks, are hydraulically advanceable, the universal roll
stand is of an especially simple configuration.
[0022] When the calibration force is smaller than the rolling force
to be exerted in the subsequent rolling processes, the spacer
elements arranged between the vertical chocks and the horizontal
chocks will not be damaged.
[0023] When the horizontal chocks and the vertical chocks, after
measuring the position values, are moved apart by position control,
the chocks can be stopped in time before reaching the
movement-limiting stops.
BRIEF DESCRIPTION OF THE DRAWING
[0024] In the drawing:
[0025] FIG. 1 is a side view of the horizontal and vertical rolls
of a universal roll stand; and
[0026] FIG. 2 is a flowchart of the method steps.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] According to FIG. 1, a universal roll stand has horizontal
rolls 1, 2 and vertical rolls 3, 4. The horizontal rolls 1, 2 are
supported in horizontal chocks 5, 6, the vertical rolls 3, 4 in
vertical chocks 7, 8. The chocks 5 through 8 are adjustable by
control elements 9-12. The control elements 9-12 are hydraulic
cylinder units. The chocks 5-8 are thus hydraulically moved.
[0028] The hydraulic cylinder units 9-12 can be moved as desired by
position control or force control. By means of the control elements
9, 10 for the horizontal rolls 1, 2, the latter are movable toward
one another (can be screwed down against one another). The vertical
rolls 3, 4 are adjustable (can be screwed down) against the
horizontal rolls 1, 2 by means of the control elements 11, 12.
[0029] The universal roll stand illustrated in FIG. 1 serves to
roll a profiled section (not illustrated in FIG. 1), for example, a
double T beam (I beam). The horizontal rolls 1, 2 roll the center
stay of the profiled section, the vertical rolls 3, 4, in
interaction with the horizontal rolls 1, 2, roll the flanges of the
profiled section. For the quality of the rolled profiled section it
is important, inter alia, that the stay is rolled
position-precisely. It is therefore important to adjust the
horizontal rolls 1, 2 vertically such that the stay is rolled
centrally. This adjustment of the horizontal rolls 1, 2 relative to
the vertical rolls 3, 4 is referred to as the so-called pass line.
This adjustment or calibration of the pass line is the subject
matter of the present invention.
[0030] The actual positions p of the hydraulic cylinder units 9, 10
are thus to be calibrated in that the functional interrelationship
between the actual positions p and the position of the lower edge
of the upper horizontal roll 1 or the position of the upper edge of
the lower horizontal roll 2 is determined relative to the pass
line.
[0031] The position of the lower edge of the upper horizontal roll
1 relative to the pass line depends on the diameter of the upper
horizontal roll 1, the spacing of the roll axis of the upper
horizontal roll 1 to the lower edge of the upper horizontal chock
5, and the spacing of the upper horizontal chock 5 relative to the
pass line.
[0032] The diameter of the upper horizontal roll 1 can be easily
measured or determined otherwise. The spacing of the roll axis of
the upper horizontal roll 1 to the lower edge of the upper
horizontal chock 5 is fixed. It is thus sufficient to measure it
once beforehand or to know it by other means. Accordingly, only the
functional interrelationship between the spacing of the lower edge
of the upper horizontal chock 5 to the pass line and the actual
position p of the hydraulic cylinder units 9 must be determined.
This is the subject matter of the method described in the
following. For evaluating the interrelationship thus determined,
the position of the vertical roll center relative to the upper edge
of the vertical chocks 7, 8 as well as, optionally, the thickness
of the spacer elements (spacers) 16 which are arranged between the
upper horizontal chock 5 and the vertical chocks 7, 8 must be
known.
[0033] The functional interrelationship between the actual
positions p of the hydraulic cylinder units 10 and the position of
the upper edge of the lower horizontal roll 2 relative to the pass
line can be determined based on analog considerations from the
functional interrelationship between the spacing of the upper edge
of the lower horizontal chock 6 to the pass line. In this
connection, the position of the vertical roll center relative to
the lower edge of the vertical chock 7, 8 as well as, optionally,
the thickness of the spacers 16 arranged between the lower
horizontal chock 6 and the vertical chocks 7, 8 are presumed to be
known.
[0034] When these parameters are known, the horizontal rolls 1, 2
can be calibrated relative to the vertical rolls 3, 4 as described
in the following in connection with FIG. 2.
[0035] First in step 13 the horizontal chocks 5, 6 are moved apart.
Subsequently, in step 14, the vertical chocks 7, 8 are moved
between the horizontal chocks 5, 6. The vertical chocks 7, 8 are
moved only so far that vertical roll gaps v1, v2 remain between the
horizontal rolls 1, 2 and the vertical rolls 3, 4. The vertical
roll gaps v1, v2 must be greater than zero, at least slightly.
[0036] Subsequently, in step 15, spacers 16 are arranged between
the vertical chocks 7, 8, on the one hand, and the horizontal
chocks 5, 6, on the other hand. These spacers 16 have flat,
smooth-surface machined contacts surfaces 16' via which they
interact with contact surfaces 5'-8' of the chocks 5-8 also
machined with a smooth surface.
[0037] Subsequently, the horizontal chocks 5, 6--simultaneously or
successively--are advanced toward one another. The advancing action
of the horizontal chocks 5, 6 is carried out in two partial
advancing steps.
[0038] First, the control elements 9, 10 are moved to an
intermediate position p1 in step 17. Subsequently, in step 18,
forces F are measured which are present in the control elements 9,
10 at this time in order to determine, based thereon, correction or
offset values with which the control elements 9, 10 for the
horizontal chocks 5, 6 are to be loaded in order to apply in the
subsequent rolling processes the desired rolling forces FW.
[0039] In the second partial advancing step, the horizontal chocks
5, 6 are then advanced farther toward one another until they rest
against (contact) the vertical chocks 7, 8 or the spacers 16. For
this purpose, in step 19, nominal end position values p2* are
preset in the control elements 9, 10. The control elements 9, 10
are then farther advanced by position control. The control elements
9, 10 exert in this connection a--corrected--force F on the
horizontal chocks 5, 6. The force F is limited to an advancing
force FV. The horizontal chocks 5, 6 are thus loaded maximally by
this advancing force FV during advancing. The horizontal chocks 5,
6 in the second partial advancing step can be advanced
simultaneously or successively against the vertical chocks 7, 8 or
against the spacers 16.
[0040] The nominal end position values p2* are selected such that
the horizontal chocks 5, 6, before reaching these nominal values
p2*, have with certainty been moved against the vertical chocks 7,
8 or against the spacers 16. Accordingly, in step 20, it is first
checked whether the force F actually exerted by the control
elements 9, 10 surpasses the advancing force FV. If this is not the
case, it is checked in step 21 whether the nominal end position
values p2* have been reached. Is that not the case, the method
sequence returns to step 21.
[0041] When the nominal end position values p2* have been reached,
this is an indication that at least one of the calibration
conditions is not fulfilled. In this case an error communication is
thus issued in step 22 and the further course of the calibration
method is not performed.
[0042] After contact of the horizontal chocks 5, 6 on the vertical
chocks 7, 8, the control elements 9, 10 are switched to force
control operation and are loaded in step 23 with a calibration
force FK. The calibration force FK is greater than the advancing
force FV but smaller than the rolling force FW which is to be
exerted in the subsequent rolling processes. Typical values for the
advancing force FV are 1% to 10% of the rolling force FW, typical
values of the calibration force FK are 10% to 30% of the rolling
force FW.
[0043] After loading the horizontal chocks 5, 6 with the
calibration force FK, the reached actual positions, respectively,
the position values p of the horizontal chocks 5, 6 are measured in
step 24. Based on the position values p, reference positions for
the subsequent rolling processes are determined and the control
elements 9, 10 are thus calibrated.
[0044] Finally, in step 25 the chocks 5-8 are moved apart by
positioned control and the spacers 16 are removed.
[0045] With the method according to the invention it is possible to
adjust in an automated sequence the horizontal rolls 1, 2 exactly
relative to the roll center of the vertical rolls 3, 4 independent
of the shape of the rolls 1 to 4.
[0046] The vertical chocks 7, 8 are, in general, of the same height
and arranged at the same level. Moreover, in general, the spacer
elements 16 are of identical height. With the method according to
the invention, the exact adjustment of the horizontal rolls 1, 2
relative to the roll center of the vertical rolls 3, 4 at the same
time also preadjusts the horizontal rolls 1, 2 horizontally and
parallel to one another.
[0047] 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.
* * * * *