EP2823901A1 - Reversing rolling mill with earliest possible activation of a thickness regulation - Google Patents

Abstract

In a roll stand (3), a metal strip (4) is reversibly rolled. The metal band (4) has two band ends (13, 15) and a center piece (16). The inlet side thickness (d1) of the metal strip (4) is detected and fed to a control device (11) which determines manipulated variables (s, F) of the roll stand (3) using the inlet side thickness (d1) and adjusts the rolling stand (3) accordingly , The outlet-side thickness (d2) of the metal strip (4) is detected and also fed to the control device (11). At least for the second strip end (15) rolled after the middle piece (16), the inlet side and outlet side speeds (v1, v2) are detected and fed to the control device (11), which uses the continuity equation to derive the outlet side thickness (d2) of the second strip end (15). An analogous approach is possible using the lengths (13, 14) instead of the velocities (v1, v2). The control device (11) stores the determined outlet-side thickness (d2) in a buffer memory (18). The control device (11) reads the corresponding thickness (d2) from the buffer memory (18) during the next rolling pass and uses it as a thickness (d1) of the now rolled before the center piece (16) in the course of determining the manipulated variables (s, F) first end of the tape (13).

Description

• wobei das Reversierwalzwerk einen ersten Haspel, einen zweiten Haspel und ein zwischen dem ersten Haspel und dem zweiten Haspel angeordnetes Walzgerüst aufweist,
• wobei zwischen dem ersten Haspel und dem Walzgerüst eine erste Dickenmesseinrichtung angeordnet ist und zwischen dem zweiten Haspel und dem Walzgerüst eine zweite Dickenmesseinrichtung angeordnet ist,
• wobei, bezogen auf das Walzgerüst, zum ersten Haspel hin eine erste Längenmesseinrichtung oder eine erste Geschwindigkeitsmesseinrichtung angeordnet ist und zum zweiten Haspel hin eine zweite Längenmesseinrichtung oder eine zweite Geschwindigkeitsmesseinrichtung angeordnet ist,
• wobei in dem Walzgerüst unter Steuerung durch eine Steuereinrichtung ein Metallband reversierend gewalzt wird, so dass während zweier unmittelbar aufeinander folgender Walzstiche einmal der erste Haspel und die erste Dickenmesseinrichtung eingangsseitig des Walzgerüsts angeordnet sind und einmal der zweite Haspel und die zweite Dickenmesseinrichtung eingangsseitig des Walzgerüsts angeordnet sind,
• wobei, bezogen auf den jeweiligen Walzstich, in dem Walzgerüst zunächst ein erstes Bandende, dann ein Mittelstück und schließlich ein zweites Bandende des Metallbandes gewalzt werden,
• wobei mittels der eingangsseitig des Walzgerüsts angeordneten Dickenmesseinrichtung für das Mittelstück und das zweite Bandende eine einlaufseitige Dicke des in das Walzgerüst einlaufenden Metallbandes erfasst und der Steuereinrichtung zugeführt wird,
• wobei von der Steuereinrichtung unter Verwendung der einlaufseitigen Dicke Stellgrößen des Walzgerüsts ermittelt werden und das Walzgerüst entsprechend den ermittelten Stellgrößen eingestellt wird,
• wobei mittels der ausgangsseitig des Walzgerüsts angeordneten Dickenmesseinrichtung zumindest für das Mittelstück und das erste Bandende eine auslaufseitige Dicke des aus dem Walzgerüst auslaufenden Metallbandes erfasst und der Steuereinrichtung zugeführt wird,
• wobei zumindest für das zweite Bandende mittels der Geschwindigkeitsmesseinrichtungen jeweils eine einlaufseitige und eine auslaufseitige Geschwindigkeit des Metallbandes oder mittels der Längenmesseinrichtungen eine einlaufseitige und eine auslaufseitige Länge des zweiten Bandendes erfasst und der Steuereinrichtung zugeführt werden,
• wobei von der Steuereinrichtung anhand der für das zweite Bandende erfassten einlaufseitigen Dicke in Verbindung mit den für das zweite Bandende erfassten Geschwindigkeiten oder Längen anhand der Kontinuitätsgleichung die auslaufseitige Dicke ermittelt wird.

The present invention relates to an operating method for a reversing mill,

• wherein the reversing mill has a first reel, a second reel and a rolling mill arranged between the first reel and the second reel,
• wherein a first thickness measuring device is arranged between the first reel and the rolling stand and a second thickness measuring device is arranged between the second reel and the rolling stand,
• wherein, relative to the rolling stand, a first length measuring device or a first speed measuring device is arranged for the first reel and a second length measuring device or a second speed measuring device is arranged for the second reel,
• wherein in the rolling stand under the control of a control means a metal strip is reversibly rolled, so that during two immediately consecutive rolling passes once the first reel and the first thickness measuring device are arranged on the input side of the rolling mill and once the second reel and the second thickness measuring device are arranged on the input side of the rolling stand .
• wherein, based on the respective rolling pass, first a strip end, then a center piece and finally a second strip end of the strip are rolled in the roll stand,
• wherein by means of the input side of the rolling stand arranged thickness measuring device for the middle piece and the second end of the tape an inlet side thickness of the incoming into the rolling mill metal band is detected and fed to the control device,
• wherein determined by the control device using the inlet-side thickness manipulated variables of the roll stand be set and the mill stand according to the determined variables,
• wherein, by means of the thickness measuring device arranged on the output side of the roll stand, at least for the center piece and the first strip end, an outlet-side thickness of the metal strip leaving the rolling stand is detected and fed to the control device,
• wherein at least for the second end of the belt by means of the speed measuring devices in each case an inlet side and an outlet side speed of the metal strip or by means of the length measuring means an inlet side and an outlet side length of the second tape end detected and fed to the control device,
• wherein the outgoing side thickness is determined by the control device based on the inlet side thickness detected for the second end of the strip in conjunction with the speeds or lengths recorded for the second end of the strip on the basis of the continuity equation.

The present invention further relates to a corresponding reversing mill.

A reversing mill usually consists of a rolling stand and two reels. In the reversing mill, a metal strip is reversibly rolled. During the individual rolling passes, the metal strip remains clamped between the reels, which means that always - albeit relatively small - end sections of the metal strip remain coiled on the reels. These two sections of the metal strip are not rolled. Furthermore, not rolled to the end portions adjacent transition sections. The remaining part of the metal strip is reversibly rolled in the roll stand in several rolling passes.

The length of the two end portions is determined by the technical requirement that the metal strip must be held by the respective reel and tensioned. The length of the two transition sections is determined by the distance between the two reels determined by the rolling stand. Depending on an end portion and the associated transition section are usually referred to as a clamping piece of the metal strip.

The rolled part of the metal strip comprises a first and a second band end and a center piece arranged between the two band ends. The first end of the tape is that portion of the metal strip that is first rolled at the beginning of a particular roll pass. The second end of the tape is that portion of the metal strip which is rolled last at the end of the particular rolling pass. The lengths of the two belt ends correspond to a distance of the inlet side and the outlet side thickness measuring device from the rolling stand.

By means of the outlet-side thickness measuring device, the outlet-side thickness of the rolled metal strip can be detected only for the center piece and for the first end of the strip. By contrast, such a detection is not possible for the second end of the tape since this end of the tape does not pass the outlet-side thickness measuring device. For the second end of the strip, which is finally rolled at the end of the respective rolling pass, its outlet-side thickness can therefore not be detected by means of the outlet-side thickness measuring device.

After completion of a specific rolling pass, the running direction of the metal strip is reversed in the immediately following roll pass. During the immediately following roll pass, therefore, the first strip end corresponds to the second strip end of the previous roll pass, which is located at the end of the previous roll pass between the roll stand and the thickness gauge no longer passed. However, since the outgoing-side thickness of this portion of the band was no longer detected by the outgoing-side thickness gauge of the previous pass, and therefore the now-entry-side thickness is not known, thickness control can not be meaningfully implemented.

From the DE 2 129 629 A1 An operating method for a reversing mill and a reversing mill of the type mentioned are known. In the from the DE 2 129 629 A1 Known operating method, the outlet-side thickness of the metal strip is determined based on the (well-known) continuity equation, that is based on the relationship that at any time in the rolling mill incoming volume of the metal strip must be equal to the expiring from the rolling mill volume of the metal strip. By means of from the DE 2 129 629 A1 known approach, the outlet side thickness of the metal strip can be determined immediately when the metal strip. Prerequisite for the application of the doctrine of DE 2 129 629 A1 is, however, that the inlet-side thickness of the metal strip is known. This is at the DE 2 129 629 A1 for the first entering the rolling mill first end of the band not the case.

From the DE 10 2008 011 275 A1 is a method of operation for a multi-stand, continuous rolling mill is known in which a determination of the outlet side strip thickness is based on the continuity equation. In this method of operation, the metal strip is rolled successively in a number of rolling mills, each rolling mill executing a rolling pass. The transport direction of the metal strip is always retained. At the time of the DE 10 2008 011 275 A1 known approach is assigned from one of the rolling stands expiring portions of the metal strip respectively determined by the continuity equation band thickness. The sections of the metal band are tracked. The assigned strip thickness is taken into account in the correct time - namely when the corresponding section of the metal strip enters the subsequent rolling stand - when determining the manipulated variables for the following rolling stand.

The object of the present invention is to provide opportunities by means of which in a reversing mill a thickness control using the continuity equation can also be realized for the first first end of the tape entering the rolling stand.

The object is achieved by an operating method for a reversing mill with the features of claim 1. Advantageous embodiments of the operating method according to the invention are the subject of the dependent claims 2 to 5.

• dass von der Steuereinrichtung zumindest für das zweite Bandende die ermittelte auslaufseitige Dicke des Metallbandes in einem Pufferspeicher gespeichert wird und
• dass die auslaufseitige Dicke des Metallbandes von der Steuereinrichtung beim nächsten Walzstich im Rahmen der Ermittlung der Stellgrößen des Walzgerüsts als einlaufseitige Dicke des ersten Bandendes des nunmehr in das Walzgerüst einlaufenden Metallbandes verwendet wird.

According to the invention, an operating method of the initially mentioned type is configured by

• in that the ascertained outlet-side thickness of the metal strip is stored in a buffer memory by the control device at least for the second end of the strip, and
• that the outlet-side thickness of the metal strip is used by the control device in the next rolling pass in the context of determining the manipulated variables of the roll stand as inlet side thickness of the first band end of the now entering the rolling mill metal strip.

The control device preferably determines the outlet-side thickness for sections of the second band end in each case. In this case, the control means stores the detected discharge side thicknesses associated with the respective portion of the second tape end in the buffer memory, and reads out the outlet side thicknesses associated with the portions in the reverse order from the buffer memory in the next pass.

It is possible that the sections are determined by a time interval or by a certain amount of rolling stock. Preferably, however, the sections have a predetermined length.

The length as such may be determined as needed. Preferably, the length of the sections corresponds to a fraction of the distance of the exit-side thickness gauge from the rolling stand. In other words, the distance of the outgoing-side thickness gauge from the rolling stand should preferably be an integer multiple of the length of a single section.

The manipulated variables are determined by the control device on the basis of a model of the roll stand such that a target thickness is expected for the metal strip leaving the rolling stand. Preferably, the controller determines, for at least the center piece, the detected outlet-side thickness with the target thickness, and the controller adopts the model of the rolling stand on the basis of the comparison.

The object is further achieved by a reversing mill with the features of claim 6. Advantageous embodiments of the reversing mill according to the invention are the subject of the dependent claims 7 to 10.

The inventive design of the reversing mill and also the advantageous embodiments of the reversing mill correspond to the above-explained embodiments of the operating method.

FIG 1 und 2

ein Reversierwalzwerk in verschiedenen Betriebszuständen,

FIG 3

ein Metallband,

FIG 4 bis 9

das Reversierwalzwerk der FIG 1 und 2 in verschiedenen Betriebszuständen und

FIG 10

ein zweites Bandende.

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 more detail in conjunction with the drawings. Here are shown in a schematic representation:

1 and 2

a reversing mill in different operating states,

FIG. 3

a metal band,

4 to 9

the reversing mill of FIG. 1 and 2 in different operating states and

FIG. 10

a second end of the tape.

According to FIG. 1 For example, a reversing mill has a first reel 1 and a second reel 2. Between the two reels 1, 2, a rolling stand 3 is arranged. Between the two Reels 1, 2 is a metal strip 4 - clamped, for example, a steel or aluminum strip - which is reversibly rolled in the roll stand 3 in several rolling passes. A respective distance a1, a2 of the two reels 1, 2 from the roll stand 3 is generally in the range of a few meters, for example at about 5 m. The distances a1, a2 are usually the same size. However, this is not mandatory.

Between the first reel 1 and the rolling stand 3, a first thickness measuring device 5 is arranged. Between the second reel 2 and the rolling mill 3, a second thickness measuring device 6 is arranged. The thickness measuring devices 5, 6 have a distance a3, a4 from the rolling stand 3. The distances a3, a4 are usually in the range of a few meters, for example at about 2 m to 3 m. The distances a3, a4 are usually the same size. However, this is not mandatory.

Relative to the roll stand 3, a first length measuring device 7 is arranged for the first reel 1. The first length measuring device 7 may be formed, for example, as a deflection roller, which is arranged between the first reel 1 and the first thickness measuring device 5 and over which the metal strip 4 is guided. For example, the first length measuring device 7 per unit length of the metal strip 4 each deliver a pulse to a first pulse counter 8, so that the number of pulses supplied to the first pulse counter 8 is proportional to the length. The unit of length is usually relatively small. For example, it can be between 1 mm and 100 mm.

Relative to the roll stand 3, a second length measuring device 9 is further arranged toward the second reel 2. The second length measuring device 9 may be formed analogously to the first length measuring device 7. In particular, the second length measuring device 9 may be assigned a second pulse counter 10, which operates analogously to the first pulse counter 8.

It is possible, by means of the two length measuring devices 7, 9 to detect in each case the length which passes through the respective length measuring device 7, 9 during a predetermined time unit of, for example, 100 ms to 1000 ms. In this case, the length measuring devices 7, 9 actually function as speed measuring devices. Alternatively, it is possible that mutually corresponding lengths are detected, which has a portion of the metal strip 4 on the inlet side and outlet side of the roll stand 3. The corresponding section can - but does not have to - be determined as such by the outlet side length, for example. In this case, it is continuously checked which length of the metal strip 4 has passed through the length measuring device 7, 9 arranged on the outlet side. As soon as this length reaches a predetermined length, the length is read out, which was detected by the length-measuring device 7, 9 arranged on the inlet side. In this case, the length measuring devices 7, 9 actually work as length measuring devices 7, 9.

The reversing mill also has a control device 11. By means of the control device 11, the rolling mill is controlled. Specifically, the controller 11 controls a setting of the rolling stand 3 and a roller peripheral speed of work rolls 12 of the rolling stand 3 during the rolling passes. Furthermore, the control device 11 controls the reel 1, 2 and receives from the various measuring devices 5 to 10 their respective measurement signals.

Due to the fact that the metal strip 4 is reversibly rolled in the rolling stand 3, the first reel 1 and the first thickness measuring device 5 are arranged on the input side of the rolling stand 3 during two immediately successive rolling passes and once the second reel 2 and the second thickness measuring device 6 on the input side of the rolling mill 3 is arranged. FIG. 1 shows a - in principle arbitrary - state during a particular rolling pass, in which the first reel 1 and the first thickness gauge 5 are arranged on the input side of the roll stand 3.

FIG. 2 shows a - also in principle arbitrary - state during that rolling pass, the immediately before or immediately after the Walzstich of FIG. 1 is performed. In this state, the second reel 2 and the second thickness measuring device 6 are arranged on the input side of the roll stand 3. During both rolling passes, the respective other reel 2, 1 and the respective other thickness measuring device 6, 5 are arranged on the output side of the roll stand 3.

FIG. 3 shows the metal strip 4, based on any of the rolling passes.

According to FIG. 3 the metal strip 4 has a first clamping piece 12. The first clamping piece 12 is arranged at the beginning of the respective rolling pass on the outlet side of the roll stand 3. The metal strip 4 furthermore has a first band end 13. The first band end 13 adjoins the first clamping piece 12. The boundary between the first clamping piece 12 and the first strip end 13 is located at the beginning of the relevant rolling pass in the nip of the rolling mill stand 3. The length 11 of the first band end 13 corresponds to the distance a3, a4 of the - based on the respective rolling pass - arranged upstream thickness measuring device. 5 6 from the rolling mill 3. The length 11 has the first band end 13 before the execution of the relevant rolling pass.

According to FIG. 3 the metal band 4 furthermore has a second clamping piece 14. The second clamping piece 14 is arranged at the end of the relevant rolling pass on the inlet side of the roll stand 3. The metal strip 4 also has a second band end 15. The second band end 15 adjoins the second clamping piece 14. The boundary between the second clamping piece 14 and the second band end 15 is located at the end of the relevant rolling pass in the nip of the rolling mill stand 3. The length 12 of the second band end 15 corresponds to the distance a3, a4 of the thickness measuring device 5 arranged downstream of the respective rolling pass , 6 from Roll stand 3. The length 12 has the second band end 15 after the execution of the relevant rolling pass.

From the above, it can be seen that the two clamping pieces 12, 14 are not rolled during the reversing rolling of the metal strip 4. It can also be seen from the above statements that a center piece 16 of the metal strip 4 is located between the two strip ends 13, 15. The band ends 13, 15 and the center piece 16 are rolled during the reversing rolling of the metal strip 4.

The 4 to 9 show different states during two immediately successive rolling passes. It may be any two directly consecutive rolling passes. The first rolling pass of the two consecutive rolling passes is referred to below as roll pass A, the rolling pass subsequently executed as roll pass B. Rolling pass A is described below in connection with FIGS FIGS. 4 to 6 explained. After complete execution of the roll pass A is transferred to roll pass B. The Walzstich B will be described below in connection with the FIGS. 7 to 9 explained.

After complete execution of the rolling pass B, a further rolling pass can be carried out which resembles the pass A from the batch. After this further rolling pass, a type-B rolling pass can be followed again, followed by a rolling pass of type A, etc.

FIG. 4 shows the state at the beginning of the Walzstichs A. At this time, the second clamping piece 14, the second band end 15 and a majority of the center piece 16 on the first reel 1 are reeled. A small part of the middle piece 16 is not wound on the first reel 1. This small part of the center piece 16 is located between the first reel 1 and the first thickness measuring device 5. The first end of the tape 13 is also not reeled on the first reel 1. It is located between the first thickness measuring device 5 and the rolling stand 3. A transport direction x of the metal strip 4 is already directed from the first reel 1 to the second reel 2.

FIG. 5 shows a state during the Walzstichs A. At this time, the second clamping piece 14, the second band end 15 and a part of the center piece 16 on the first reel 1 are reeled. On the other hand, another part of the center piece 16 has already been rolled in the course of the roll pass A and wound on the second reel 2 together with the first strip end 13 and the first clamping piece 12. The transport direction x of the metal strip 4 is still directed from the first reel 1 to the second reel 2.

FIG. 6 shows the state at the end of the roll pass A. At this time, the first chuck 12, the first band end 13 and a majority of the center piece 16 are reeled on the second reel 2. A small part of the middle piece 16 is not reeled on the second reel 2. This small part of the center piece 16 is located between the second reel 2 and the second thickness gauge 6. The second end of the tape 15 is also not reeled on the second reel 2. It is located between the second thickness gauge 6 and the roll stand 3. The transport direction x of the metal strip 4 is still directed from the first reel 1 to the second reel 2.

FIG. 7 shows the state at the beginning of the rolling pass B. At this time, the second chuck 14, the second band end 15 and a majority of the center piece 16 on the second reel 2 are reeled. A small part of the middle piece 16 is not reeled on the second reel 2. This small part of the center piece 16 is located between the second reel 2 and the second thickness measuring device 6. The first end of the tape 13 is also not reeled on the second reel 2. It is located between the second thickness gauge 6 and the rolling stand 3. The transport direction x of the metal strip 4 is already directed from the second reel 2 to the first reel 1.

FIG. 8 shows a state during the rolling pass B. At this time, the second chuck 14, the second band end 15 and a part of the center piece 16 on the second reel 2 are reeled. On the other hand, another part of the center piece 16 has already been rolled in the course of the roll pass B and wound up on the first reel 1 together with the first strip end 13 and the first clamping piece 12. The transport direction x of the metal strip 4 is still directed from the second reel 2 to the first reel 1.

FIG. 9 shows the state at the end of the Walzstichs B. At this time, the first chuck 12, the first band end 13 and a majority of the center piece 16 on the first reel 1 are reeled. A small part of the middle piece 16 is not wound on the first reel 1. This small part of the center piece 16 is located between the first reel 1 and the first thickness measuring device 5. The second end of the tape 15 is also not reeled on the first reel 1. It is located between the first thickness measuring device 5 and the roll stand 3. The transport direction x of the metal strip 4 is still directed from the second reel 2 to the first reel 1.

During the rolling passes A and B, the inlet-side thickness d1 of the metal strip 4 can be detected by means of the thickness measuring device 5, 6 arranged on the input side of the roll stand 3 for the center piece 16 and the second strip end 15 entering the roll stand 3 after the middle piece 16. The detected inlet-side thickness d1 is fed to the control device 11 from the thickness-measuring device 5, 6 arranged on the input side.

In both rolling passes 4 manipulated variables s, F of the roll stand 3 are determined by the control device 11 using the inlet-side thickness d1 of the metal strip 3, for example a rolling gap s and / or a rolling force F. The determined manipulated variables s, F are output by the control device 11 to the rolling stand 3 in the correct time, ie at the time at which the respective section of the metal strip 4 whose incoming thickness d1 was detected in Roll stand 3 is rolled. The roll stand 3 is thereby adjusted in a timely manner accordingly. To determine the manipulated variables s, F, the control device 11 uses a model 11 'of the rolling stand 3. The control device 11 determines the manipulated variables s, F on the basis of the model 11' such that a target thickness d * is expected for the metal strip 4 expiring from the rolling stand 3 becomes.

During the rolling passes A and B is further by means of the respectively arranged on the output side of the roll stand 3 thickness gauge 5, 6 for the center piece 16 and the front of the center 16 in the rolling mill 3 incoming first strip end 13, the outlet side thickness d2 of the rolling mill 3 expiring metal strip. 4 detected. The detected outlet-side thickness d2 is likewise supplied to the control device 11 by the thickness-measuring device 5, 6 arranged on the output side.

die auslaufseitige Dicke d2 des zweiten Bandendes 15 ermittelt. Die so ermittelte auslaufseitige Dicke d2 des entsprechenden Abschnitts wird von der Steuereinrichtung 11 in einem der Steuereinrichtung 11 zugeordneten Pufferspeicher 18 gespeichert. Die auslaufseitige Dicke d2 des Metallbandes 4 wird von der Steuereinrichtung 11 beim nächsten Walzstich im Rahmen der Ermittlung der Stellgrößen s, F des Walzgerüsts 3 als einlaufseitige Dicke d1 des ersten Bandendes 13 des nunmehr in das Walzgerüst 3 einlaufenden Metallbandes 4 verwendet.From the representations of 4 to 9 It can be seen that in the context of rolling passes A and B, although before the rolling of the second band end 15 by means of the input side thickness measuring device 5, 6, the inlet side thickness d1 of the second band end 15 is detected, but not after rolling the second band end 15 by means of For this reason, as part of the rolling passes A and B at least for the second end of the tape 15 by means of the speed measuring devices 7, 9 each have an inlet side and an outlet side speed v1, v2 of the metal strip 4 detected and supplied to the controller 11. From the controller 11 is in this case based on the relationship $$d2=d1\cdot \frac{v1}{v2}$$

the outlet-side thickness d2 of the second band end 15 is determined. The thus determined outlet-side thickness d2 of the corresponding section is stored by the control device 11 in a buffer memory 18 assigned to the control device 11. The outlet-side thickness d2 of the metal strip 4 is used by the control device 11 at the next rolling pass in the course of determining the manipulated variables s, F of the roll stand 3 as inlet side thickness d1 of the first band end 13 of the metal strip 4 now entering the rolling mill 3.

It is possible to carry out the above-described procedure once for the second band end 15 as such. Preferably, however, the second band end 15 according to FIG. 10 divided into sections 17. The sections 17 may be determined as needed. Preferably, the sections 17 have a predetermined length 13. The length 13 should preferably be a fraction of the distance a3, a4 of the thickness measuring device 5, 6 arranged on the output side of the roll stand 3.

In the case of dividing the second band end 15 into the sections 17, the control device 11 determines the outlet side thickness d2 for each of the sections 17. Furthermore, the control device 11 stores the determined outlet side thicknesses d2 in association with the respective corresponding section 17 of the metal strip 4 in the buffer memory 18. When reading the controller 11 reads the corresponding sections 17 associated outlet-side thicknesses d2 in the next roll pass in the reverse order from the buffer memory 18 from.

ermittelt werden. Auch diese Gleichung ist eine Kontinuitätsgleichung. Auslaufseitig ist die Länge 13 in diesem Fall durch das zweite Bandende 15 oder die Unterteilung des zweiten Bandendes 15 in die Abschnitte 17 gegeben. Die Länge 14 des jeweils korrespondierenden einlaufenden Abschnitts muss mittels der einlaufseitigen Längenmesseinrichtung 7, 9 erfasst werden.By means of the length measuring devices 7, 9, as stated above, as an alternative or in addition to the speeds v1, v2, the respective length of the metal strip 4 be recorded. If this is the case, the respective outflow-side thickness d2 can, as an alternative to using the speeds v1, v2, according to the relationship $$d2=d1\cdot \frac{l4}{l3}$$

be determined. Again, this equation is a continuity equation. On the outlet side, the length 13 is given in this case by the second band end 15 or the division of the second band end 15 in the sections 17. The length 14 of the corresponding incoming section must be detected by means of the inlet-side length measuring device 7, 9.

The outlet side thickness d2 determined according to equation 1 or equation 2 represents only an estimated value, but not a directly measured value. If the model 11 'is faulty, model errors are perpetuated, so to speak, in the second end of the tape 15. In order to eliminate model errors, the control device 11 therefore compares in the rolling passes the respectively detected outlet-side thickness d2 with the target thickness d *. On the basis of the comparison, the control device 11 adapts the model 11 'of the roll stand 3. The comparison of the respectively detected outlet side thickness d2 with the target thickness d * and the adaptation of the model 11' of the rolling stand 3 are preferably performed by the control device 11 for the center piece 16 and first end of the tape 13 performed. But at least the comparison and the adaptation should be performed for the center piece 16.

In summary, the essence of the present invention thus consists in the following procedure:

In a roll stand 3, a metal strip 4 is reversibly rolled. The metal band 4 has two band ends 13, 15 and a center piece 16. The inlet-side thickness d1 of the metal strip 4 is detected and fed to a control device 11 which determined using the inlet-side thickness d1 manipulated variables s, F of the roll stand 3 and the mill stand 3 adjusted accordingly. The outlet side thickness d2 of the metal strip 4 is detected and also fed to the control device 11. At least for the second strip end 15 rolled after the center piece 16, the inlet-side and outlet-side speeds v1, v2 are detected and fed to the control device 11, which determines the outlet-side thickness d2 of the second strip end 15 on the basis of the equation of continuity. An analogous approach is possible using lengths 13, 14 instead of velocities v1, v2. The control device 11 stores the determined outlet-side thickness d2 in a buffer memory 18. The control device 11 reads the corresponding thickness d2 from the buffer memory 18 during the next rolling pass and uses it as the thickness d1 of the now before the center piece in the course of determining the control variables s, F. 16 rolled first band end 13.

The procedures according to the invention provide in particular the advantage that the thickness control can be switched on earlier and the target thickness d * can be reached faster than in the prior art. Furthermore, in particular the so-called dimension dimension is reduced by the distances a3, a4 of the thickness measuring devices 5, 6 from the roll stand 3. The output of the reversing mill is thus increased.

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

Claims (10)

Operating method for a reversing mill, - wherein the reversing mill has a first reel (1), a second reel (2) and a between the first reel (1) and the second reel (2) arranged rolling mill (3), wherein between the first reel (1) and the rolling stand (3) a first thickness measuring device (5) is arranged and between the second reel (2) and the rolling stand (3) a second thickness measuring device (6) is arranged, wherein, relative to the rolling stand (3), a first length measuring device (7) or a first speed measuring device (7) is arranged for the first reel (1) and a second length measuring device (9) or a second length is provided for the second reel (2) Speed measuring device (9) is arranged, - wherein in the rolling stand (3) under control of a control device (11) a metal strip (4) is reversibly rolled, so that during two immediately successive rolling passes once the first reel (1) and the first thickness gauge (5) on the input side of the rolling stand (3) are arranged and once the second reel (2) and the second thickness measuring device (6) are arranged on the input side of the roll stand (3), - wherein, based on the respective rolling pass, in the roll stand (3) first a first band end (13), then a center piece (16) and finally a second band end (15) of the metal strip (4) are rolled, - By means of the input side of the roll stand (3) arranged thickness measuring means (5, 6) for the middle piece (16) and the second band end (15) detects an inlet side thickness (d1) of the rolling mill (3) incoming metal strip (4) and the control device (11) is supplied, in which control variables (s, F) of the roll stand (3) are determined by the control device (11) using the inlet-side thickness (d1) and the rolling stand (3) is set according to the determined control variables (s, F), - Wherein by means of the output side of the roll stand (3) arranged thickness measuring means (5, 6) at least for the middle piece (16) and the first band end (13) an outlet side thickness (d2) of the rolling mill (3) expiring metal strip (4) detected and the control device (11) is supplied, - At least for the second band end (15) by means of the speed measuring devices (7, 9) respectively an inlet side and an outlet side speed (v1, v2) of the metal strip (4) or by means of the length measuring means (7, 9) an inlet side and an outlet side length (13, 14) of the second band end (15) are detected and fed to the control device (11), - wherein by the control device (11) on the basis of the second end of the tape (15) detected inlet side thickness (d1) in conjunction with the detected for the second tape end (15) velocities (v1, v2) or lengths (13, 14) based on Continuity equation the outlet side thickness (d2) is determined
characterized, - That of the control device (11) at least for the second tape end (15), the determined outlet side thickness (d2) of the metal strip (4) is stored in a buffer memory (18) and in that the outlet-side thickness (d2) of the metal strip (4) from the control device (11) during the next rolling pass in the course of determining the manipulated variables (s, F) of the roll stand (3) as the inlet-side thickness (d1) of the first strip end (13) of now in the roll stand (3) incoming metal strip (4) is used. Operating method according to claim 1,
characterized, in that the control device (11) determines the outlet-side thickness (d2) for sections (17) of the second band end (15), - That the control device (11) the determined outlet side thicknesses (d2) under assignment to the respective section (17) of the second tape end (15) in the buffer memory (18) stores and - That the control device (11) the corresponding sections (17) associated outgoing side thicknesses (d2) in the next rolling pass in reverse order from the buffer memory (18) reads out. Operating method according to claim 2,
characterized,
in that the sections (17) have a predetermined length (13). Operating method according to claim 3,
characterized,
that the length (13) of the sections (17) with a fraction of the distance (a3, a4) corresponding to the output-side thickness measuring device (5, 6) of the roll stand (3). Operating method according to one of the above claims, characterized in that the control variables (s, F) are determined by the control device (11) on the basis of a model (11 ') of the roll stand (3) such that a target thickness (d *) is obtained for the metal strip (4) leaving the rolling stand (3). ) is expected - That of the control device (11) at least for the center piece (16), the detected outlet side thickness (d2) with the target thickness (d *) is compared and - That of the control device (11), the model (11 ') of the roll stand (3) is adapted based on the comparison. reversing, - wherein the reversing mill has a first reel (1), a second reel (2) and a between the first reel (1) and the second reel (2) arranged rolling mill (3), - Wherein between the first reel (1) and the rolling stand (3) a first thickness measuring device (5) is arranged, and a second thickness measuring device (6) is arranged between the second reel (2) and the rolling stand (3), wherein, relative to the rolling stand (3), a first length measuring device (7) or a first speed measuring device (7) is arranged for the first reel (1) and a second length measuring device (9) or a second length is provided for the second reel (2) Speed measuring device (9) is arranged, - wherein the reversing mill has a control device (11), under whose control in the roll stand (3) a metal strip (4) is reversibly rolled, so that during two immediately consecutive rolling passes once the first reel (1) and the first thickness gauge (5 ) are arranged on the input side of the roll stand (3) and once the second reel (2) and the second thickness gauge (6) are arranged on the input side of the roll stand (3), - wherein, based on the respective rolling pass, in the roll stand (3) first a first band end (13), then a center piece (16) and finally a second band end (15) of the metal strip (4) are rolled, - By means of the input side of the roll stand (3) arranged thickness measuring means (5, 6) for the middle piece (16) and the second band end (15) detects an inlet side thickness (d1) of the rolling mill (3) incoming metal strip (4) and the control device (11) is supplied, in which control variables (s, F) of the roll stand (3) are determined by the control device (11) using the inlet-side thickness (d1) and the rolling stand (3) is set according to the determined control variables (s, F), - Wherein by means of the output side of the roll stand (3) arranged thickness measuring means (5, 6) at least for the middle piece (16) and the first band end (13) an outlet side thickness (d2) of the rolling mill (3) expiring metal strip (4) detected and the control device (11) is supplied, - At least for the second band end (15) by means of the speed measuring means (7, 9) each have an inlet side and an outlet side speed (v1, v2) of the metal strip (4) or by means of the length measuring means (7, 9) an inlet side and an outlet side length (13, 14) of the second tape end (15) are detected and fed to the control device (11), - wherein by the control device (11) on the basis of the second end of the tape (15) detected inlet side thickness (d1) in conjunction with the detected for the second tape end (15) velocities (v1, v2) or lengths (13, 14) based on Continuity equation the outlet side thickness (d2) is determined
characterized, - That the control device (11) is associated with a buffer memory (18), - That the determined outlet side thickness (d2) of the metal strip (4) in the buffer memory (18) is stored by the control device (11) at least for the second band end (15) and in that the outlet-side thickness (d2) of the metal strip (4) from the control device (11) during the next rolling pass in the course of determining the manipulated variables (s, F) of the roll stand (3) as the inlet-side thickness (d1) of the first strip end (13) of now in the roll stand (3) incoming metal strip (4) is used. Reversing mill according to claim 6,
characterized, in that the control device (11) determines the outlet-side thickness (d2) for sections (17) of the second band end (15), - That the control device (11) stores the determined outlet side thicknesses (d2) in association with the respective section (17) of the second band end (15) in the buffer memory (18) and - That the control device (11) the corresponding sections (17) associated outgoing side thicknesses (d2) in the next rolling pass in reverse order from the buffer memory (18) reads out. Reversing mill according to claim 7,
characterized,
in that the sections (17) have a predetermined length (13). Reversing mill according to claim 8,
characterized,
that the length (13) of the sections (17) with a fraction of the distance (a3, a4) corresponding to the output-side thickness measuring device (5, 6) of the roll stand (3). Reversing mill according to one of claims 6 to 9, characterized in that the control variables (s, F) are determined by the control device (11) on the basis of a model (11 ') of the roll stand (3) such that a target thickness (d *) is obtained for the metal strip (4) leaving the rolling stand (3). ) is expected - That of the control device (11) at least for the center piece (16), the detected outlet side thickness (d2) with the target thickness (d *) is compared and - That of the control device (11), the model (11 ') of the roll stand (3) is adapted based on the comparison.

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