EP3419771A1

EP3419771A1 - Complete compensation of roll eccentricities

Info

Publication number: EP3419771A1
Application number: EP17704240.5A
Authority: EP
Inventors: Matthias Kurz; Birger Schmidt
Original assignee: Primetals Technologies Germany GmbH
Current assignee: Primetals Technologies Germany GmbH
Priority date: 2016-02-23
Filing date: 2017-02-09
Publication date: 2019-01-02
Anticipated expiration: 2037-02-09
Also published as: WO2017144278A1; CN109070164B; EP3210682A1; EP3419771B2; CN109070164A; EP3419771B1

Abstract

A roll stand for rolling a flat rolling material (3) made of metal has an upper set (U) of rolls and a lower set (L) of rolls with corresponding working rolls (1U, 1L) and support rolls (2U, 2L). The flat rolling material (3) is rolled during a normal operation. In this way, based on first and second variables (RUB, RLB, φ1UB, φ1LB, RUW, RLW, φ2UW, φ2LW) that are characteristic for an eccentricity of the support rolls (2U, 2L) and the working rolls (1U, 1L) of the roll stand according to an angular position (φ UB, φ UW, φ LB, φ LW) of at least one roll (1U, 1L, 2U, 2L) of the roll stand, a control device (4) continuously determines a compensation value (ε) that is dependent on the angular position (φ UB, φ UW, φ LB, φ LW). The control device (4) corrects a roll gap target value (s*) for the roll stand with the compensation value (ε) and correspondingly acts on the roll frame. In this way, the angular positions (φ UB, φ UW, φ LB, φ LW) of only the working rolls (1U, 1L) or only the support rolls (2U, 2L) of the roll frame are detected. The angular positions (φ UB, φ UW, φ LB, φ LW) of the other rolls (1U, 1L, 2U, 2L) are determined from the detected angular positions (φ UB, φ UW, φ LB, φ LW). However, for the determined angular positions (φ UB, φ UW, φ LB, φ LW), the respective occurrence of a reference angular position is detected and supplied to the control device (4).

Description

description

Complete compensation of roll eccentricities The present invention is based on an operating method for a roll stand for rolling a flat rolled stock of metal,

the whale scaffold having an upper set of rolls and a lower set of rolls,

- wherein the upper set of rolls having at least one upper Arbeitswal ^¬ ze and an upper backup roll and the lower Wal ^¬ zensatz at least a lower working roll and a lower backup roll,

wherein the rolling mill is operated at least temporarily in a normal operation,

- Wherein the roll stand is operated during rolling of the flat rolling ^¬ good in normal operation,

- Wherein during the rolling of the flat rolling a control ^¬ device for the whale zgerüst continuously

on the basis of first quantities which are responsible for an eccentricity of the

Support rollers of the roll stand as a function of a Drehstel ^¬ treatment of at least one roller of the rolling stand are characteris ^¬ table, and second sizes, which are cha ^¬ characteristic of an eccentricity of the work rolls of the rolling stand as a function of a rotational position of at least one roller of the rolling stand, one of the rotational position of the at least one roller of the rolling mill dependent Kompensa ^¬ tion value is obtained,

- corrects a nip value for the rolling mill by the calculated compensation value, and

- setting a roll gap of the rolling mill according to the Corridor ^¬ alloyed nip setpoint,

so that the flat rolled metal is rolled entspre ^¬ accordingly by means of the rolling mill the corrected Wal zspaltsoliwert.

The present invention further relates to a Compu ^¬ terprogramm for a control device of a roll stand for rolling a flat rolled product made of metal, wherein the computer Program machine code includes, which is directly abarbeitbar by the control device, wherein the processing of the machine code by the control means causes the control means operates the rolling stand according to such an operating method.

The present invention further is directed to a STEU ^¬ ereinrichtung for a whale zgerüst to Wal zen of a flat rolled product made of metal, wherein the control means is formed such Removing that it operates the rolling mill according to such a method of operation.

The present invention is further based on a rolling stand for rolling a flat rolled stock of metal, wherein the rolling stand is controlled by such a control device.

An operating method of the type mentioned is known for example from DE 24 16 867 AI or. of the corresponding US Pat. No. 3,893,317.

The object of the present invention is to provide possibilities by means of which a total eccentricity occurring during rolling of a flat rolling stock can be corrected in the simplest possible way in all possible case constellations. The determination and the correction should be possible in particular independently of which rollers of the roll stand the total eccentricity is caused to which part.

The object is achieved by an operating method for a rolling stand for rolling a flat metal rolling stock with the features of claim 1. Advantageous ^Ausgestaltun conditions of the operating ^method according to the invention are the subject of the dependent claims 2 to 9.

According to the invention, an operating method of the type mentioned at the outset is thereby issued - That the rotational position of only the work rolls or only the support rollers of the rolling mill are detected and received by the control device,

- That the rotational positions of the enigen rollers, the rotational positions are not detected, are determined by the control device from the rotational positions of the enigen rollers whose rotational positions are detected, and

- That for rollers whose rotational positions are not detected, but determined, respectively, the passing of a Rete- renzdrehstellung detected and the control device is supplied.

This approach not only compensates for any eccentricity, regardless of whether it is caused by the work rolls or the backup rolls. Rather, it is possible to provide only a portion of the rollers - namely the work rolls or the support rollers - with position encoders and yet to determine the rotational positions derj enigen rollers that have no position encoder, with high accuracy over long periods of rolling operation.

In particular, rolling torques must be exerted on the work rolls of the rolling stand for rolling the flat rolled stock. This is done via scaffold drives. As a rule, the scaffolding drives act directly on the work rolls. In rare cases, the support rollers are driven, so that the scaffold drives act indirectly on the Arbeitswal zen. As a rule, continue to have the Stand drives to position encoder, wel ^¬ che directly output location signals are characteristic of the rotational position of the e- weiligen scaffolding drive. On the basis of these signals, the rotational positions of the driven rollers can be determined directly, possibly in conjunction with translations of gears arranged between the scaffold drives and the driven rollers. For these rollers own position encoders are therefore not required for detecting the rotational position. Rather, the rotational positions of these rollers can be determined from the rotational positions of the driven rollers in conjunction with the rolling condition. By However, the inventive design, the accumulation of a deviation of the rotational position over several revolutions of the rollers can be avoided, however, since with each passing of the eweiligen reference rotational position by the j whale Wal ze a new synchronization is made possible.

In a preferred embodiment of the present invention, the roll stand is temporarily be exaggerated ^¬ in a calibration mode in which no flat rolling is rolled by the roll stand. In this case, it is possible that the control ^¬ device in calibration

for a number of defined initial rotational positions of both the upper set of rolls and the lower set of rolls, controls the roll stand such that the upper work roll rests on the lower work roll and the

Roll off rolls,

- each j in each case collected during the rolling of the rolls over an outgoing from the eweiligen initial rotational position detection eweilige length a of the rotational position of using at least one roller-dependent profile of a characteristic of a Change ^¬ tion of the roll gap signal and

- Determines the first and second quantities based on the recorded gradients. In some cases, it will suffice for the number of initial rotational positions to be equal to 1, that is, the control means only for a single initial rotational position of the upper set of rollers in conjunction with a single initial rotational position of the lower set of rollers during the rolling of the rollers together over one of these two initial rotational positions Detection length recorded the course of the characteristic of the change of the roll gap signal. This procedure can be particularly ausrei ^¬ chen when the diameter of the support rollers differ from each other to a sufficient extent and the diameter of the Arbeitswal zen differ from each other to a sufficient extent or only together for the two support rollers together on the one hand and the two work rolls _n

5

in each case an eccentricity component is determined. When executed ^¬ gen the diameter of the supporting rolls are nearly identical and / or the diameter of the work rolls are nearly identical, and for all four Wal zen j in each case a separate Kompensati- to be onsanteil determined, it is he ^¬ conducive in many cases that the number at initial rotational positions is greater than 1. For example, if the number of initial rotational positions is two, then after detecting one course of one of the two sets of rollers relative to the other roller set, the number of initial rotational positions may be rotated by a predetermined rolling length. The rolling length may for example correspond to half a revolution of one of the two rolls of the respective set of rolls. Thereafter, the other course is detected. It is therefore not important that the initial rotational positions of both sets of rolls are changed. Only a twisting relative to each other is required. As an alternative to an independent determination of the first and second variables in a calibration operation, it is possible for the first and second variables of the control device to be predetermined by a higher-level control device or by an operator. For example, when grinding the rolls in a grinding shop, a corresponding determination of the first and second sizes can take place so that they are already known when the rolls are installed in the roll stand.

In a preferred embodiment of the operating method is provided

that the first quantities characterize the eccentricity of the back-up rolls as a function of the rotational position of the back-up rolls,

- That the second sizes characterize the eccentricity of the work rolls as a function of the rotational position of the work rolls and - That the control device determines the compensation value in dependence on the rotational position of both the work rolls and the support rollers. In some cases it may be sufficient for the support rollers on the one hand and the Arbeitswal zen other each to determine an ex ^¬ zentrizitätsanteil and determine the compensation value of ^¬ hand of the two Exzentrizitätsanteile. This simplified procedure can be particularly sufficient if the diameters of the support rollers are equal to one another and the diameters of the work rollers are equal to one another.

In practice, the Arbeitswal zen with each other, however, usually slightly different diameters.

The same applies to the support rollers with each other. Preferably, the operating method is therefore designed in such a way that

- That the rotational positions of the support rollers of the rolling mill are determined or detected independently and that the rotational positions of the work rolls of the rolling mill are determined or detected independently,

- that the first variables include variables which charac- terisieren caused by the upper back-up roll eccentricity in depen ^¬ dependence on the rotational position of the upper backup roll, and include sizes which caused by the lower backup roll eccentricity depending on the rotational position of the lower backup roll characterize,

- that the second variables include variables which characterize caused by the upper work roll eccentricity in Ab ^¬ dependence on the rotational position of the upper work roll, and include sizes which caused by the lower work roll eccentricity in depen ^¬ dependence on the rotational position of the lower work roll characterize, and

- That the control means the compensation value as a function of the j eweiligen rotational position of both the upper and lower work roll and the upper and lower backup roll determined.

In this case, the compensation value has four parts of eccentricity whose sum is equal to the compensation value, namely one eccentricity component each for the upper back-up roll, the lower back-up roll, the upper work roll and the lower work roll. In a further preferred embodiment of the present invention is carried out in normal operation during rolling breaks, while ^¬ ing no flat rolling is rolled, rotating the rolls of the rolling mill counter to the direction of rotation during rolling of the last rolled flat rolled stock. Characterized kön- NEN particularly in the case that not all rotational positions are detected, but some rotational positions of the erfass- th orders are derived, errors are minimized, which otherwise away due to the accumulation of one deviate ^¬ monitoring the rotational position over several revolutions of the rolls would add up.

In a further preferred embodiment of the present invention, during rolling pauses during which no flat rolled product is rolled, the upper and / or lower roll set is rotated such that when rolling the next flat roll stock, a cost function is minimized, into which one passes the sum of the eccentricities of the work rolls and the backup rolls formed total eccentricity, the first zeitli ^¬ che derivation of the total eccentricity and / or the second time derivative of the total eccentricity enter. As a rule, only one of these three variables will enter the cost function. However, it is also possible that several of these variables are included in the cost function. As a rule, the minimization of the cost function occurs in normal operation. But they may, if the characteristics of the next to be rolled flat rolled material are already known, also made at the end of the Ka ^¬ libri heritage drive. In the event that the cost function only Gesamtexzent ^¬ rizität received, to be compensated Gesamtexzentrizi ^¬ ty can be minimized. In an analogous manner, in the event that only the first time derivation of the total eccentricity enters the cost function, the speed with which the roll gap must be adjusted can be minimized. In an analogous manner, in the event that only the second time derivative of the total eccentricity enters into the cost function, the acceleration with which the roll gap must be adjusted can be minimized.

In many cases, the procedure according to the invention already leads to excellent results. In some cases, however, a residual eccentricity may still occur despite the correction of the roll gap setpoint by the calculated compensation value. To compensate for such Restex ^¬ centricity, it is preferably provided that the control device during the rolling of the flat rolling stock detected in a signal which is characteristic of the residual eccentricity. In this case, the control device can track the first and second variables based on the residual eccentricity.

The object is further achieved by a computer program having the features of claim 10. According to the invention, a computer program of the aforementioned type is configured in that the processing of the computer program by the control device causes the control device to operate the rolling stand in accordance with an operating method according to the invention.

The object is further achieved by a control device having the features of claim 11. According to the invention, the control device is designed such that it operates the rolling stand in accordance with an operating method according to the invention. The object is further achieved by a roll stand with the Merk ^¬ paint of claim 12. According to the invention a rolling ^¬ scaffold of the type mentioned is thereby configured such that the roll stand is controlled by an inventive control device.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments which will be described in detail in conjunction with the drawings. Here are shown in a schematic representation:

1 shows a perspective view of a rolling stand, FIG. 2 shows a side view of the rolling stand of FIG. 1,

3 shows a flow chart,

4 shows two work rolls and two back-up rolls,

5 shows a time course of a Exzentrizitätssig ^¬ nals,

FIG. 6 shows associated paths on roller circumferences, FIG.

7 shows two time profiles of eccentricity signals,

8 shows associated paths on roll peripheries,

9 shows a roller and its change of the radius,

10 is a flowchart,

Figure 11 is a measured and an associated modeled Ex ^¬ centricity compared,

FIG 12 associated paths on roller circumferences and

13 shows a flowchart. Referring to Figs 1 and 2 comprises a roll stand on an upper Wal ^¬ zensatz U and a lower set of rolls L. The upper roller set U has an upper work roll 1U and an upper backup roll 2U. The lower roll set L has a lower work roll IL and a lower backup roll 2L. By means of the rolling mill is a flat rolled 3 made of metal ge ^¬ rolls. The flat rolling stock 3 may in particular be a heavy plate or a metal strip. The metal from which the flat rolling stock 3 is made, in particular steel be . Alternatively, it may be aluminum, copper, brass or another metal.

The rolling stand is controlled by a control device 4. The control device 4 is designed such that it operates the roll stand according to an operating method, which is explained in more detail after ^¬ standing.

As a rule, the control device 4 is designed as a programmable control device 4. In this case, the ent ^¬ speaking training of the control device 4, so that it operates the mill stand according to the operating method, effected by a computer program 5, with which the control device 4 is programmed. The computer program 5 comprises machine code 6, which can be processed directly by the control device 4. The execution of the machine code 6 through the STEU ^¬ ereinrichtung 4 causes, in this case, the control device 4 operates the rolling stand according to the corresponding operation ^{information model.}

The rolling stand is operated by the control device 4 at least temporarily in a normal operation. In particular, the rolling of the flat rolled stock 3 takes place in normal operation. Often, the whale zgerüst by the control device 4 continues to operate for a while temporarily in a calibration mode. In calibration operation no flat rolling stock is rolled by means of the roll stand 3. It is assumed below that the rolling ^{stand is} alternatively operated by the control device 4 in normal operation or in calibration operation.

Therefore, the control device 4 checks according to FIG 3, first, in a step Sl, whether the rolling mill in normal operation Betrie ^¬ ben is. If the rolling mill is operated in normal operation, the control device 4 checks in step S2, whether currently a rolling stock 3 is rolled. If a rolling stock 3 is currently being rolled, the control device 4 proceeds to steps S3 to S7. In step S3, a set roll gap s * is set. In a step S4, the control device 4 accepts a rotational position cpUB, cpUW, cpLB, cpLW of at least one roller 1U, IL, 2U, 2L of the roll stand. In step S5, the control inputs determined direction 4 at least one of the ε of the rotational position CPUB, cpUW, cpLB, φLW a roller 1U, IL, 2U, 2L of the rolling mill depen ^¬ Gigen compensation value. The determination is made on the basis of variables RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW, for a total eccentricity of the rolls 1U, 2U, 2L of the rolling mill as a function of the rotational position cpUB, cpUW, cpLB, cpLW the at least one roller 1U, IL, 2U, 2L of the roll stand are charac ^¬ teristic. The sizes RUB, RLB, cplUB, cplLB are first quantities that are characteristic of an eccentricity of the rolling mill support rolls 2U, 2L as a function of a rotational position cpUB, cpUW, cpLB, cpLW of at least one rolling mill 1U, IL, 2U, 2L of the rolling stand. Analogously, the quantities RUW, RLW, cp2UW, cp2LW are second quantities which correspond to an eccentricity of the work rolls 1U, IL as a function of a rotational position cpUB, cpUW, cpLB, cpLW of at least one roll 1U, IL, 2U, 2L of the rolling stand are characteristic. The meaning of the first quantities RUB, RLB, cplUB, cplLB and the second quantities RUW, RLW, cp2UW, cp2LW will become clear later.

In step S 6, the control means corrects 4 the roll gap set value S * to the value determined in step S4 Kompensati ^¬ onswert ε. In step S7, the control device 4 sets a rolling gap s of the roll stand according to the corrected set roll gap value. Thereby, the flat rolled metal 3 with ^¬ means of the rolling mill roll gap according to the corrected target value of an initial thickness to a final thickness Gewal zt.

From step S7, the control device returns to step S1. The sequence of steps Sl to S7 is therefore currency ^¬ rend continuously performed rolling of the flat rolled stock 3 of the control inputs direction. 4

Although the control device 4 operates the rolling mill in normal operation, but currently no flat rolled rolled is the controller 4 moves from step S2 to step S8. In step S8, other measures can be taken ^¬ he later explained in more detail. When the controller 4, the mill does not operate normally ^¬ operation, there is the mill in calibration operation ^¬. In this case, the controller proceeds to Schrit ^¬ th S9 to S14. In calibration mode, the first and second quantities RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW are determined.

In step S 9, a defined initial rotational position of the upper roller set U and a defined initial rotational position of the lower roller set L of the rolling mill are set. Examples game, the two initial rotational positions can be adjusted so that in FIG 4 shown (only gedank ^¬ Lich existing) points of the upper work roll 1U and the upper backup roll 2U each other directly opposite each other and shown in a manner analogous to in FIG 4 (only existing conceptually dene) points of the lower work roll IL and the lower backup roll 2L are directly opposite each other. For this purpose, for example, the rolling stand can be ascended so that the upper work roll 1U and the lower work roll IL do not touch each other. Thereafter, the two sets of rollers U, L are rotated independently of each other in their initial initial rotational position.

In order to be able to rotate the two sets of rollers U, L independently of one another into their initial initial rotational position, the rollers 1U, 2U of the upper roller set U are lifted off the rollers IL, 2L of the lower roller set L. To rotate the sets of rolls U, L as such, for example, as shown in FIG. 1, independent drives 7U, 7L for the two sets of rolls U, L can be present. Alternatively, a common drive may be present, which is permanently connected, for example, with the lower set of rollers L, with the upper set of rollers U j edoch via a releasable coupling. In this case, first the upper roller set U in its initial rotational position transferred, then the clutch is released, and it is the lower set of rollers L transferred to its initial ^¬ position. Then the clutch is closed again.

After rotating the two sets of rolls U, L in their eweilige initial rotational position, the control device 4 controls such the rolling mill in the step S10 that the roll gap is CLOSED s ^¬ sen. The closing of the roll gap s takes place without the flat rolling stock being in the roll gap s. With the

Closing of the roll gap s is thus the upper Arbeitswal ^¬ ze 1U on the lower work roll IL on.

Then, the control device 4 controls the rolling stand in step S11 such that the rolls 1U, IL, 2U, 2L roll against each other. This state - ie the rolling of the rollers 1U, IL, 2U, 2L together - is maintained for a relatively long length LO. The length LO is hereinafter referred to as Erfassungslän ^¬ ge LO. The detection length LO starts from the respective initial rotational position of the roller sets U, L. It is particularly dimensioned such that all rollers 1U, IL, 2U, 2L perform several complete revolutions.

During the rolling of the rollers 1U, IL, 2U, 2L, the control device 4 detects in step Sil at the same time over the detection length LO a course of a signal F, s, which is characteristic of a change in the roll gap s. The signal F, s is of course dependent on the rotational position cpUB, cpUW, cpLB, cpLW of the at least one roller 1U, IL, 2U, 2L. For example, the control device 4 the

Roll stand in the course of the step Sil roll gap controlled at a constant setting of the roll gap s hold and as a characteristic signal s, F the associated rolling force F he ^¬ grasp. Likewise, the control device 4, conversely, the rolling stand in the context of the step Sil with rolling force controlled with a constant rolling force F operate and as characteristic ^¬ cal signal s, F detect the resulting nip s. In both cases, the detected signal s, F directly reflects the Total eccentricity ε. 5 shows purely by way of example the change in the resulting roll gap s in the case of a rolling force control over a detection length LO of 30 m and a diameter of the work rolls 1U, IL of approximately 1.00 m and a diameter of the support rolls 2U, 2L with a diameter of approx. 1.65 m. 6 shows purely as an example the kor ^¬ respondierenden revolutions of the work rolls 1U, IL and the support rollers 2U, 2L. In some cases it may be sufficient to carry out the procedure of steps S 9 to Sil on a single pair of initial ^¬ rotational positions. In this case, the controller 4 proceeds directly to step S14. Otherwise, the control device 4 first proceeds to step S12. In step S12 the controller 4 checks whether it has already performed the Pre 9 ^¬ hens, the step S to Sil for all erforder ^¬ union pairs of initial rotational positions. Only when this is the case, the controller 4 moves to step S14.

If this is not the case, the control device 4 proceeds from step S12 to step S13. In step S13 selec ^¬ advantage, the controller 4 the next pair of initial ^¬ rotating positions. From step S13, the controller then returns to step S9.

The number of other pairs of initial rotational positions and the associated positions as such may be determined as needed. If necessary, the initial rotational position of lower roller set L can be unchanged, while the upper roller set ^{¬ is} rotated in each case by a predetermined angle of the upper work roll 1U or the upper support roll 2U. The reverse procedure is also possible. It is also possible that both sets of rollers U, L are rotated.

In particular, in the case of only a single further pair of initial rotational positions of the predetermined angle example ^¬ , as shown in dashed lines in FIG 4, with a half Rotation of the upper support roller 2U correspond. In this case, 7 yields as shown in FIG ^¬ additionally to a different form of the signal s, F. 8 shows the associated rotational speeds of the work rolls 1U, IL and the support rollers 2U, 2L.

In step S14, the control device 4 uses the detected courses to determine the first and second variables RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW. The basics of this investigation are explained in more detail below.

Ideally, a roller 8 should be perfectly round, so have kei ^¬ nerlei eccentricity. In practice, however, this is not the case. FIG. 9 shows - greatly exaggerated - a variation of a radius r of the roller 8 as a function of the rotational position φ of the roller 8 relative to a reference position. Mathematically, the radius r can be written as a function of the rotational position φ as r (<p) = rO + T Sri ^■ sin (z ^' ^ - <pi) (1)

= i rO herein refers to the average (ideal) Radius der Wal ^¬ ze 8. 5ri denotes the fraction of the i-th interference. cpi denotes a phase angle of the i-th perturbation.

For the backup rollers 2U, 2L all disturbances are relevant, since only the radius is effective for the nip s. For the work rolls 1U, IL, however, only the even disturbances are relevant, since for the work rolls 1U, IL for the nip s the diameter is effective. Further, considering only the disturbance at the lowest effective frequency for all the rolls 1U, 2U, 2L, 2L, ie the first disturbance for the back-up rolls 2U, 2L and the second disturbance for the work rolls 1U, IL, the resulting eccentricity ε can be obtained Write as ε = RUB ^■ sin (<pUβ - φ \ ί ^' Β) + RLB ^■ s \ n {(pLβ - φ \ ΙΒ)

+ RUW sm {2 (UW - <p2UW) + RL W · sin (2 ^ /, W - φ2ί W) ⁽²⁾

Here are

RUB is the eccentricity amplitude of the upper back-up roll 2U, RUW is the eccentricity amplitude of the upper work roll 1U,

RLB the eccentricity amplitude of the lower back-up roll 2L,

RLW is the eccentricity amplitude of the lower work roll 1U,

- φΙϋΒ the phase angle of the first disturbance of the eccentricity of the upper support roller 2U,

cp2UW the phase position of the second eccentricity error of the upper work roll 1U,

cplLB the phase angle of the first disturbance of the eccentricity of the lower support roller 2L,

cp2LW the phase position of the second disturbance of the eccentricity of the lower work roll 1U,

cpUB the rotational position of the upper support roller 2U,

cpUW the rotational position of the upper work roll 1U,

- cpLB the rotational position of the lower support roller 2L and

- cpLW the rotational position of the lower work roll 1U.

In Equation 2, eight quantities are unknown, namely the four eccentricity amplitudes RUB, RUW, RLW, RLB and the four phase positions cplUB, cp2UW, cplLB, cp2LW.

In order to determine these eight variables RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW, an optimization problem can now be set up by means of which the deviation of a norm is minimized. So try the minimum of ° (pUW, <pL W, φί.Β) ε '(cpUB, q> UW, <pL W, (3) where ε is the eccentricity measured for certain rotational positions cpUB,, 9LB, 9LW and ε' is the eccentricity same rotational positions cpUB, 9ÜW, 9LB, φΙΜ is calculated eccentricity according to equation 2. 1 is the one on the circumference of the rollers 1U, IL, 2U, 2L traveled route. Such optimizations are familiar to those skilled in the art. The determination of the rotational positions CPUB, cpUW, cpLB, cpLW is readily possible because the (mean) radius of the rollers 1U, IL, 2U, 2L are known to continue the initial rotational positions (for 1 = 0) are known and closing ^¬ Lich Rolling condition applies, that is, the rollers 1U, IL, 2U, 2L cover the same paths when unrolling.

In individual cases, it may be sufficient to detect the rotational position cpUB, cpUW, cpLB, cpLW only a single roller 1U, IL, 2U, 2L and the rotational positions cpUB, cpUW, cpLB, cpLW the other rollers 1U, IL, 2U, 2L from the detected rotational position cpUB, cpUW, cpLB, cpLW in conjunction with the known radii or. Ducts of rolls 1U, IL, 2U, 2L deduce. In particular, over long distances, this is due to Rutschbewe ^¬ conditions and however due to variations of the radii due to the eccentricities too imprecise.

It is possible, as shown in FIG. 1, to detect the rotational positions cpUB, cpUW, cpLB, cpLW of both the back-up rolls 2U, 2L and the work rolls 1U, 1L of the roll stand by means of corresponding rotary position encoders 9U, 9L. The detected rotational positions cpUB, cpUW, cpLB, cpLW are in this case supplied to the control device 4 and received by the control device 4. Regarding one

Pair of similar rollers 1U, IL, 2U, 2L - usually the back-up rollers 2U, 2L - in this case, an additional pair of rotary position sensors 9U, 9L required for this. The other pair of similar rolls 1U, IL, 2U, 2L - usually the work rolls 1U, IL - is, however, by means of

Roll stand drives 7U, 7L driven. The rolling mill drives 7U, 7L generally have internal rotary encoder on. Their signals can be used according to the invention for determining the rotational positions cpUB, cpUW, cpLB, cpLW of the driven rollers 1U, 2U, 2U, 2L.

Alternatively, it may be sufficient, per roll set U, L, only the rotational position cpUB, cpUW, cpLB, cpLW of one of the rolls 1U, 2U, 2U, 2L of the corresponding set of rollers U, L to capture. In this case, only these rotational positions cpUB, cpUW, cpLB, cpLW are accepted by the control device 4. The rotational position cpUB, cpLB, cpUW, cpLW of the respective other roller 2U, 2L, 1U, IL of the corresponding set of rollers U, L in this case by the control device 4 on the basis of the rotational position cpUB, cpUW, cpLB, cpLW the enigen roll 1U, IL , 2U, 2L of the corresponding set of rolls U, L, whose rotational position cpUB, cpUW, cpLB, cpLW is detected. This procedure is taken in this case, both in normal operation and in calibration ^..

Since according to the invention (for example) only the rotational positions cpUW, cpLW of the work rolls IL, 1U are detected and the rotational positions cpUB, cpLB of the back-up rolls 2U, 2L are derived from the rotational positions cpUW, cpLW of the work rolls 1U, IL, there is the danger that over larger Distances (corresponding to many complete revolutions of the back-up rolls 2U, 2L) will make the rotational positions cpUB, cpLB of the back-up rolls 2U, 2L too inaccurate. To solve this problem, two alternative embodiments are possible, but in principle can be combined with each other.

On the one hand, it is possible that, during a break in the roll, the rolls 1U, 2U, 2L of the roll stand are rotated counter to the direction of rotation into which the rolls 1U, 2U, 2L are rotated during the rolling of the flat roll 3 rolled last , The rollers 1U, IL, 2U, 2L are therefore turned back. Turning back is a possible development of the Schrit- tes S8 third of FIG Accordingly, the rolling mill is operated to the ^¬ sem time in normal operation. The turning back is thus carried out as part of a normal rolling break between the rolling of two flat rolling stock 3. It is not a calibration operation in which the first and second quantities RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW are determined. As a result of this measure it is possible for defects to occur during the rolling of a single flat rolling mill. guts 3 accumulate, but then again a reduction of the accrued error occurs.

According to the invention, however, the support rollers 2U, 2L reference signal generator 1 OU, 1 OL assigned. Although the reference signal transmitters 1 OU, 1 OL do not detect the rotational position cpUB, cpLB of the support rollers 2U, 2L over the entire angular range of 360 °. However, they always emit a signal (for example a pulse) when the rotational position cpUB, cpLB of the corresponding support roller 2U, 2L corresponds to a predetermined reference rotational position. By means of the reference signal generators 1 OU, 1 OL, the passing of the reference rotational position is thereby always detected during continuous rotation of the support rollers 2U, 2L. The corresponding signals are of course supplied to the control device 4. This can therefore - both during normal operation and in calibration - to j Eder vollständi ^¬ gen revolution of the corresponding Stützwal ze 2U, 2L a new synchronization of the rotary movement of the respective support roller 2U, 2L relative to the rotational movement of the work roll 1U, IL of the corresponding roll set U, Make L.

Of course, the reverse procedure is also possible, that is, that the rotational positions cpUB, cpLB of the support rollers 2U, 2L are detected, the rotational positions cpUW, cpLW of the work rolls 1U, IL from the rotational positions cpUB, cpLB of

Support rollers 2U, 2L are derived and in each case the passing of a reference rotational position is detected for the work ^{rolls ¬} 1U, IL. In the above, a procedure was explained in the (so ^¬ well in normal operation and in the calibration mode), the rotational ^¬ positions CPUB, cpLB the support rollers 2U and 2L are independently determined or detected, and also the rotation Stel ^¬ lungs cpUW, cpLW the work rolls 1U, IL can be determined or recorded independently of each other. Thus, all four rotational positions cpUB, cpUW, cpLB, cpLW are explicitly detected or determined. In this case, the total eccentricity ε is the sum of the partial eccentricities of the rolls 1U, IL, 2U, 2L. For each roller 1U, IL, 2U, 2L, the control device 4 thus determines, depending on the rotational position cpUB, cpUW, cpLB, cpLW of the respective roller 1U, IL, 2U, 2L, of the corresponding roller 1U, IL, 2U , 2L centricity caused Teilex- and adds the eccentric cam parts for Gesamtex ^¬ centricity. The controller 4 thus determined in the Nor ^¬ malbetrieb the compensation value ε as a function of eweiligen rotational position CPUB, cpUW, cpLB, cpLW both the upper and lower work roll 1U, IL as well as the upper and lower support roller 2U, 2L.

In order to be able to determine the four partial eccentricities mentioned above, the control device 4 must also know the corresponding characteristic variables RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, c2LW. As part of the calibration operation he ^¬ thus averages the control means 4 for the upper Stützwal ^¬ ze 2U the sizes RUB, CPUb which are characteristic for their Teilexzentrizität. In an analogous manner the upper work roll 1U and the lower work roll IL j in each case takes place in calibration for the lower support roller 2L He ^¬ averaging of the two for the Teilexzentrizität the j eweiligen roller 2L, 1U, IL characteristic quantities RUW, RLW, RLB, cp2UW, cplLB, cp2LW. The radii resp. Diameter of the support rollers 2L, 2U are usually the same size among each other. Likewise, the radii or. Diameter of the work rolls 1U, IL with each other usually the same size. If it can be guaranteed that only a sufficiently small slip between the rollers 1U, 2U of the upper roll set U with respect to the rollers 1U, IL of the lower roller set L occurs between two calibrations hervorgerufe ^¬ nen by the support rollers 2U, 2L eccentric cam parts can be summarized and also the part eccentricities caused by the work rolls 1U, IL can be summarized. Also in this case, the total eccentricity is the sum of

Part eccentricities of the back-up rolls 2U, 2L and the work rolls 1U, IL. The sum, however, in this case only has two Summands on, namely one for the partial eccentricity caused by the support rollers 2U, 2L and for the partial eccentricity caused by the work rolls 1U, 2L. The control device 4 determines in this case in normal operation in dependence on the rotational position cpUW, cpLW one of the work rolls 1U, IL a part eccentricity for the Arbeitswal ^¬ zen 1U, IL and depending on the rotational position cpUB, cpLB one of the support rollers 2U, 2L a part eccentricity for the back-up rolls 2U, 2L. Furthermore, in this case, it adds the two partial eccentricities to the total eccentricity ε. In this case as well, the control device 4 determines the compensation value ε as a function of the rotational position cpUB, cpUW, cpLB, cpLW of both the work rolls 1U, IL and the support rolls 2U, 2L in normal operation. As part of the calibration operation, the control device 4 determines in this case for the two support rollers 2U, 2L uniform variables that are characteristic of the Teilxzentrizität, for example, a Exzentrizitätsamplitude and a phase angle. He also ^¬ averages the control device 4 in this case, in the calibration operation for the two working rolls 1U, IL uniform large ^¬ SEN, which are characteristic of their Teilexzentrizität, for example a Exzentrizitätsamplitude and a phase ^¬ position. Furthermore, 10 steps S21 through S23 may be present during rolling breaks corresponding to the depicting ^¬ lung in FIG. The

Steps S21 to S23 are one possible embodiment of step S8 of FIG. 1. According to FIG. 10, the control device 4 determines a cost function K in step S21. For example, the total eccentricity .epsilon., Weighted by the respective weighting factors .theta. the first time derivation of the total eccentricity ε and / or the second time-dependent derivation of the total eccentricity ε. It is possible that all three weighting factors θ to 2 are different from 0. Alternatively, it is possible that only two of the weighting factors θ to 2 are different from 0. min- However, at least one of the three weighting factors θ to 2 must be different from 0. The weighting factors θ to .2 may be fixedly assigned to the control device 4 or determined by a user within the scope of a parameterization. In this case, the control device 4 further determines in step S22 a minimum of the cost function K over a rolled length LI. So it forms the integral

C \\ ^K ¥ ^l (4), and minimizes the integral in that they 1U of the rolls, IL, 2U, 2L varied rotational positions CPUB, cpUW, cpLB, cpLW is started to which the rolling of the next material to be rolled flat. 3 The rolled length LI is - with respect to the lateral surfaces of the rolls 1U, IL, 2U, 2L - that length over which the rolls 1U, IL, 2U, 2L roll this flat rolling stock 3. In step S23, the control device 4 then adjusts the rotational positions cpUB, cpUW, cpLB, cpLW of the rollers 1U, IL, 2U, 2L accordingly. The control device 4 thus rotates the upper and / or lower roller set U, L in such a way that the cost function K during rolling of the next flat rolling stock 3 is minimized.

It is possible that as part of step S23, the Walzge ^¬ skeleton has been closed. In this case, the two sets of rollers U, L can only be rotated together. Alternatively, the rolling stand can be opened. In this case, the two sets of rollers U, L can be rotated independently.

The procedure according to the invention leads to excellent results. FIG 11 shows, purely by way of example a comparison between a measured (M) ε eccentricity and ε an associated modeled (C) eccentricity, so ε a Exzent ^¬ rizität, the reference to the Exzentrizitätsamplituden RUB, RUW, RLW, RLB and phase positions club, cp2UW, cplLB, cp2LW, where the eccentricity amplitudes RUB, RUW, RLW, RLB and phase positions clUB, cp2UW, cplLB, cp2LW were determined on the basis of the measured profile of the eccentricity ε. FIG. 12 shows the associated profile of the revolutions of the rolls 1U, 2U, 2U.

Ideally, by applying the compensation signal ε, the eccentricities of the rollers 1U, 2U, 2U, 2L are completely compensated. Etc. due to thermal effects, United ^¬ wear. it may happen j edoch that despite the correc- tion of the roll gap set value s * by the determined Kompensati ^¬ onswert ε only incomplete compensation is performed, so that a residual eccentricity sr remains. It is mög ^¬ Lich therefore, that the control device 4 outputs a signal F, Z corresponding to the detected depicting ^¬ lung in FIG 13 during the rolling of the flat rolled product 3 in a step S31 that is characteristic of the Res ^¬ texzentrizität sr. This signal F, Z may be, for example, the rolling force F or egg ^¬ NEN front of or behind the rolling stand prevailing in the flat rolling train Z 3. A thickness of the flat rolled stock 3 measured on the outlet side of the roll stand can also be used as a signal.

In this case, on the one hand, the control device 4 in a step S32 currently - that is, during the rolling of the flat rolled material 3 - compensate for the residual eccentricity he. In this case, the control device 4 thus corrects the Wal zspaltSollwert s * not only by the compensation value ε, but in addition to the residual eccentricity he. Furthermore, in this case, the control device 4 can track the first and second variables RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW in a step S33. It is even possible that the control device 4, the first and second sizes RUB, RLB, cplUB, cplLB, RUW, RLW, cp2UW, cp2LW fully with reference to the residual eccentricity _ε Γ determined that the amplitudes RUB, RLB, RUW, RLW of the individual eccentricities so initially have the value 0. The phase positions cplUB, cplLB, cp2UW, cp2LW are irrelevant in this case. In the context of the explanation of the present invention, first and second quantities RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW eccentricity amplitudes RUB, RUW, RLW, RLB and phase positions clUB, cp2UW, cplLB, cp2LW were used above. The eccentricities of the rollers 1U, IL, 2U, 2L could alter natively but also by amplitudes AUB, BUB, ALB, BLB, AUW, BUW, ALW, BLW of corresponding sine and cosine functions are described. Instead of equation 2, therefore, the following equation 5 could also be assumed. ε = A UB ^■ sin φϋΒ + BUB ^■ cos pUB + ALB sin ψΙ.Β + BLB cos φί.Β

+ A UW sin 2 <pU \ V + BUW cos 2 U + ALW sin 2φί W + BL W cos 2ψΙΛΥ ^<5)

The present invention has many advantages. In particular, all the centrifugal zooms can be determined and compensated. This is true regardless of whether the eccentricities caused by work rolls 1U, IL or 2U support rollers, 2L. Furthermore, the roll eccentricities can be determined faster and more accurately. Furthermore, the roll eccentricities can be determined even if the rolling mill has, in addition to the work rolls 1U, IL and the support rollers 2U, 2L more rollers, particularly Zvi ^¬ rule the work rolls 1U, IL and the support rollers 2U, 2L disposed intermediate rolls.

Although the invention in detail by the preferred embodiment has been illustrated and described in detail, the invention is not limited ^¬ by the disclosed examples and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention. Reference sign

I L, 1U workhorse

2 L, 2U back-up rolls

3 flat rolling stock

4 control device

5 computer program

6 machine code

7U, 7L rolling mill drives

8 roller

9U, 9L rotary encoder

10U, 10L reference signal generator

C modeled eccentricity K cost function

L, U roller sets

LO acquisition length

LI rolled length

M measured eccentricity r radius

rO average radius

RUB, RUW, RLW, RLB eccentricity amplitudes Rolling gap

s * nominal roll gap

Sl to S33 steps

Οίθ to OL2 weighting factors

5ri error

ε compensation value

ε, ε ', ετ eccentricities

φί phase position

cpUB, φυ ί, (pLB, cpLW rotational positions

φΐυΒ, φ2υ ί, φ Ι ΕΒ, 92LW eccentricity phases

Claims

claims

1. Operating experience for a rolling stand for rolling a flat rolling stock (3) of metal,

- wherein the roll stand comprises an upper set of rolls (U) and a lower set of rolls (L),

- wherein the upper roll set (U) comprises at least one upper Ar ^¬ beitswalze (1U) and an upper supporting roller (2U) and the lower set of rolls (L) at least one lower Arbeitswal- ze (IL) and a lower support roller (2L) which

- wherein the rolling mill is operated at least temporarily in a Normalbe ^¬ shoot,

- Wherein the roll stand is operated during the rolling of the flat rolling ^¬ good (3) in normal operation,

- Wherein during the rolling of the flat rolled stock (3) a

Continuous control device (4) for the roll stand - based on first quantities (RUB, RLB, cplUB, cplLB) which are used for eccentricity of the support rolls (2U, 2L) of the rolling mill as a function of a rotational position (cpUB, cpUW, cpLB, cpLW) of at least one roller (1U, IL, 2U, 2L) of the rolling stand, and second quantities (RUW, RLW, cp2UW, cp2LW), which are indicative of an eccentricity of the work rolls (1U, IL) of the rolling stand as a function of Rotary position (cpUB, cpUW, cpLB, cpLW) of at least one roller (1U, IL, 2U, 2L) of the rolling mill are characteristic, one of the rotational position (cpUB, cpUW, cpLB, cpLW) of the at least one roller (1U, IL, 2U , 2L) determines the roll stand from ^¬ dependent compensation value (ε),

- a roll gap setpoint (s *) for the rolling stand corrected by the calculated compensation value (ε) and

a rolling nip (s) of the roll stand according to

adjusted corrected roll gap setpoint,

so that the flat rolled metal (3) is rolled ent ^¬ speaking by means of the rolling mill the corrected Wal zspaltsoliwert, characterized in

that the rotational position (cpUB, cpUW, cpLB, cpLW) only the work rolls (1U, IL) or only the back-up rolls (2U, 2L) of the rolling scaffold detected and received by the control device (4),

- That the rotational positions (cpUB, cpUW, cpLB, cpLW) of enigen

Rollers (1U, IL, 2U, 2L) whose rotational positions (cpUB, cpUW, cpLB, cpLW) are not detected by the control device

(4) from the rotational positions (cpUB, cpUW, cpLB, cpLW) derj enigen rollers, (1U, IL, 2U, 2L) whose rotational positions (cpUB, cpUW, cpLB, cpLW) are detected, determined and

- that for rollers (1U, IL, 2U, 2L), whose rotational positions

(cpUB, cpUW, cpLB, cpLW) is not detected, but determined who ^¬ the, each passing a reference rotational position detected and the control device (4) is supplied.

2. Operating method according to claim 1,

characterized ,

that the roll stand temporarily in a calibration mode ^¬ be driven is, in the no flat rolled by the roll stand (3) rolled and that the control device (4) in calibration

for a number of defined initial rotational positions of both the upper roller set (U) and the lower roller set ^¬ (L), the rolling stand controls such that the upper work roll (1U) on the lower work roll (IL) is on ^¬ and the rollers ( 1U, IL, 2U, 2L) roll against each other, - during the rolling of the rollers (1U, IL, 2U, 2L) aneinan ^¬ the emanating from a respective initial starting position eweilige detection length (LO) each one of the rotational position (cpUB, cpUW, cpLB, cpLW) of the at least one roller (1U, IL, 2U, 2L) dependent course of a for a change of the roll gap (s) characteristic signal (s, F) detected and

- Based on the recorded gradients, the first and second quantities (RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW) determined.

3. Operating method according to claim 2,

characterized ,

that the number of initial rotational positions is greater than 1. 2 ö

4. Operating method according to claim 1,

characterized ,

the first and second variables (RUB, RLB, cplUB, cplLB, RUW, RLW, cp2UW, cp2LW) of the control device (4) are specified by a higher-level control device or by an operator.

5. Operating method according to one of the above claims,

- that the first sizes (RUB, RLB, cplUB, cplLB) characterize the eccentricity of the back-up rolls (2U, 2L) in dependence on the rotational position (cpUB, cpLB) of the back-up rolls (2U, 2L),

- that the second quantities (RUW, RLW, cp2UW, cp2LW) characterize the eccentricity of the work rolls (1U, IL) as a function of the rotational position (cpUW, cpLW) of the work rolls (1U, IL) and

- That the control device (4) determines the compensation value (ε) in dependence on the rotational position (cpUB, cpUW, cpLB, cpLW) of both the work rolls (1U, IL) and the support rollers (2U, 2L).

6. Operating method according to claim 5,

characterized ,

- That the rotational positions (cpUB, cpLB) of the support rollers (2U, 2L) of the roll stand are independently detected or detected and that the rotational positions (cpUW, cpLW) of the work rolls (1U, IL) of the rolling mill are determined or detected independently .

- That the first sizes (RUB, RLB, cplUB, cplLB) sizes (RUB, cplUB), which characterize the eccentricity caused by the upper support roller (2U) in dependence on the rotation ^¬ position (cpUB) of the upper support roller (2U) , and sizes (RLB, cplLB) which determine the eccentricity caused by the lower back-up roll (2L), as a function of the rotational position (cpLB) of the lower back-up roll

Characterize (2L)

- that the second quantities (RUW, RLW, cp2UW, cp2LW) include sizes (RUW, cp2UW) that correspond to those through the upper work roll (1U) eccentricity in dependence on the rotational position (cpUW) of the upper work roll (1U), and include quantities (RLW, cp2LW) which determine the eccentricity caused by the lower work roll (IL) as a function of the rotational position (cpLW) characterize the lower work roll (IL), and

in that the control device (4) determines the compensation value (ε) as a function of the respective rotational position (cpUB, cpUW, cpLB, cpLW) of both the upper and lower work rolls (1U, IL) and the upper and lower support rolls (2U, 2L ).

7. Operating method according to one of claims 1 to 6, d a d e r c h e c e n e c e n e,

that in normal operation during rolling breaks, during which no flat rolling stock (3) is rolled, a rotation of the rollers (1U, IL, 2U, 2L) of the roll stand opposite to the direction of rotation during rolling of the last rolled flat rolled stock (3) he follows ^¬ .

8. Operating method according to one of the above claims, d a d u c h e c e n e c e n e,

during rolling breaks, during which no flat rolling stock (3) is rolled, the upper and / or lower set of rolls (U, L) are rotated in such a way that a cost function (K) is minimized when rolling the next flat rolled stock (3), in which formed a by the sum of the eccentricities of the work rolls (1U, IL) and the support rollers (2U, 2L) total eccentricity (ε), the first time derivative (έ) to the total eccentricity (ε) and / or the second time from ^¬ line (ε) enter the total eccentricity (ε).

9. Operating method according to one of the preceding claims, d a d e r c h e c e n e c e n e,

that the control device (4) during rolling of the fla ^¬ chen rolled stock (3) detects a signal (F, Z), the (s) is characteristic of a residual eccentricity, in spite of the correction of the roll gap set value (s *) by the determined grain - (ε) occurs pensationswert, and the first and second large ^¬ SEN (RUB, RUW, RLW, RLB, cplUB, cp2UW, cplLB, cp2LW) based on the residual eccentricity (s) readjusts.

10. Computer program for a control device (4) of a

Roll stand for rolling a flat rolled stock (3) of metal, the computer program comprising machine code (6) which is directly executable by the control unit (4), wherein the processing of the machine code (6) by the control unit (4) causes that the control device (4) the

Roll stand according to an operation experienced according to one of the above claims operates.

11. control device for a whale zgerüst for Wal zen a flat rolling stock (3) made of metal, wherein the control device is designed such that it operates the rolling stand according to an operating method according to one of claims 1 to 9.

12. rolling stand for rolling a flat rolled stock (3) made of metal, wherein the rolling mill is controlled by a control device (4) according to claim 11.