Method and device for rolling a metal strip
Patent Information
- Application Number
- PCT/EP2026/054685
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-21
- Filing Date
- 2026-02-20
- Publication Date
- 2026-08-27
Smart Images
Figure EP2026054685_27082026_PF_FP_ABST
Abstract
Description
[0001] Method and apparatus for rolling a metal strip
[0002] The invention relates to a method and a device for rolling, in particular for cold rolling, a metal strip.
[0003] When rolling flat metal strip, it can be wound and unwound multiple times before and / or after the initial rolling process. During this winding, plastic deformations occur, depending on the strip geometry and the specific process conditions. These deformations alter the flatness of the metal strip. Flatness is a crucial quality characteristic of cold-rolled metal strip. Excessive unevenness can significantly disrupt subsequent processing, or in the worst case, render it impossible, or lead to quality problems in the final products. For this reason, it may be necessary to add further processing steps, such as stretch bending, to the cold rolling process and then wind the metal strip in such a way that no further changes in flatness occur. These processing steps reduce productivity, are costly, and can negatively impact other quality characteristics, such as material properties.
[0004] To counteract flatness variations during the cold rolling process, the prior art employs a function that pre-controls a target flatness in the final pass. This pre-control sets a flatness level during the rolling process that compensates for the flatness changes caused by machining. This compensation is intended to ensure that the metal strip achieves the target flatness for the final product, the so-called offline flatness, after the flatness changes resulting from machining. However, this function can currently only be configured and set manually. Furthermore, the flatness changes depend primarily on the properties of the metal strip and also vary with process parameters such as strip tension. Consequently, the result of the pre-control cannot be reliably predicted and fluctuates considerably, especially with wide product ranges.
[0005] Page 1. Studies and algorithms are known from the literature that can calculate the change in flatness during processing from the relevant basic data of the cold rolling process. These models can only calculate the change in flatness as accurately as the quality of the available basic data allows. A key parameter here is the strip thickness profile in the width direction of the metal strip. This is often measured during the hot rolling process. However, the transfer of this information to the subsequent cold rolling process is usually inadequate. The profile is not displayed across the width at the required resolution, intermediate steps that change the strip position are not taken into account, or the division of the coiled metal strip into two coils is not represented synchronously with the strip position. When modeling thermal effects, the models must make assumptions about boundary conditions that can vary considerably in practice.Since these parameters cannot usually be directly captured during online operation, an inaccuracy arises in the forecasting. Therefore, using the models to calculate the control parameters for a (cold) rolling mill for the compensation function leads to significant inaccuracies.
[0006] The invention is based on the objective of further developing a known method and a known device for rolling a metal strip in such a way that the flatness of the metal strip as an end product, the so-called offline flatness, i.e. the flatness of the metal strip after its rolling and any possible second processing, is significantly improved, even if the metal strip is subject to a first processing before its rolling which affects its flatness.
[0007] This problem is solved by the method claimed in claim 1. It comprises the following steps:
[0008] Page 2a) Determining the actual flatness at a length position of the metal strip before initial processing;
[0009] b) Initial processing of the metal strip immediately after flatness determination; c) - d) Determining the actual flatness of the metal strip at the length position immediately after initial processing;
[0010] e) Determining a position-synchronous change in flatness of the metal strip caused by processing as the difference between the determined actual flatness before the first processing and the actual flatness after the first processing of the metal strip, each at the same length position;
[0011] f) Rolling the first processed metal strip, thereby influencing the flatness of the metal strip;
[0012] g) Determining a target flatness value for the metal strip for flatness feedforward control or flatness control for the rolling of the metal strip according to step f) using a transfer model based on the properties of the metal strip before and after the first processing, based on the determined flatness change, based on a target flatness specification for the metal strip at the length position after its rolling according to step f) and after a second processing, and / or based on the properties of the metal strip before and after the second processing; and
[0013] h) Performing flatness pre-control or flatness control for the metal strip with the target flatness determined by the transfer model, generating a control variable that influences the rolling step f).
[0014] The term "flatness" refers to the evenness of the metal strip. A metal strip is flat when it is even, meaning, in particular, when it has no waves or bumps. Flatness can be measured online, for example, by measuring the strip tension distribution across the width of the metal strip. A uniform distribution of strip tension across the width of the metal strip is a representative indicator of flatness. Alternatively, flatness can also be determined offline.
[0015] Page 3 will be, e.g. by measuring the height of the visible waviness of the metal strip using a flatness measuring roller.
[0016] The term "immediately" means that the flatness of the metal strip is not changed between the immediately successive steps.
[0017] The term "processing" generally refers to any handling or treatment of the metal strip that positively or negatively affects its flatness. This includes, in particular, processes such as rewinding the metal strip (i.e., winding and / or unwinding), trimming, coating, and / or cleaning. In exceptional cases, processing may also be neutral with regard to the flatness of the metal strip, i.e., it may not affect the flatness at all. Such processing can take place in a first and / or second processing unit. The terms "first" and "second" processing refer to processing operations before and after rolling. The term "first processing" does not preclude the possibility that the metal strip was previously manufactured and processed in various ways.
[0018] The term "influencing variable" refers to a control signal at the output of the flatness feedforward control or flatness control system for controlling a suitable flatness actuator, which can be used to influence the flatness of the metal strip during the rolling step f). Influencing variables include, for example, the rolling force, which can be influenced by adjusting cylinders of a rolling stand as a flatness actuator; bending forces, which can be influenced by bending cylinders as flatness actuators; pivot values for pivoting the work and / or backup roll set, which can be influenced by pivot drives as flatness actuators; or the strip tension, which can also be influenced by the adjusting cylinders.
[0019] The term "positionally synchronous" means that the determination of the actual flatness of the metal strip before and after processing, which is necessary for determining the change in flatness, is carried out at the same point.
[0020] Page 4. Length position xo. Accordingly, the resulting change in flatness also refers to the same length position xo. The position-synchronous change in flatness thus determined advantageously takes into account all the basic data relating to the respective metal strip and the current process boundary conditions. The basic data and the process boundary conditions correspond, by way of example, to at least some of the data used to classify the strip type; see the list of data further down in the description.
[0021] The difference between the claimed flatness feedforward control and the alternatively claimed flatness control lies in the fact that the feedforward control operates without feedback, while the control system does. The flatness control system therefore receives not only the target flatness but also a signal representing the actual flatness of the metal strip after its rolling in process step f). The target flatness and the actual flatness are then compared within the flatness control system, and a flatness control deviation is determined. Based on this control deviation, at least one control signal is generated to actuate at least one flatness actuator of the rolling stand used for the rolling process. This control system offers the advantage of continuously ensuring the highest possible adherence to the target flatness during rolling step f).
[0022] The advantage of the method claimed according to the invention is that the flatness of the metal strip is improved after rolling by taking into account the determined position-synchronous change in flatness that the metal strip has undergone due to a previous first processing operation in the flatness feedforward control or flatness control for the metal strip.
[0023] Page 5 More precisely: The determined position-synchronous flatness change is advantageously used according to process step g) to determine a suitable target flatness as an input for the flatness feedforward control or flatness control for the rolling of the metal strip according to step f). This is done using a transfer model which, for this purpose according to process step g), receives a variety of different input variables, such as the properties of the metal strip before and after the first and / or second processing, the determined flatness change before and after the first processing, and a target flatness specification for the metal strip at length position x0 after its rolling. By taking these parameters into account, a simple yet accurate calculation of the target flatness for the flatness feedforward control or flatness control is possible.This automatically leads to a more accurate calculation of at least one control variable for the rolling step f) at the output of the flatness feedforward control or flatness control in step h).
[0024] By applying the control variables thus determined to the rolling step f), i.e. the appropriate control of suitable flatness control elements during the rolling step f), as further provided in process step h), it is advantageously possible to significantly improve the flatness of the final product, i.e. the metal strip after the rolling has taken place or after the second processing, i.e. the so-called offline flatness.
[0025] According to one variant, the specified target flatness corresponds to the target flatness of the metal strip after rolling. This applies if the metal strip, after rolling according to step f), does not undergo any further processing that would impair its flatness. This would be an ideal case.
[0026] However, if the metal strip undergoes a second processing step after its rolling according to f) which impairs its flatness, then according to a second variant it makes sense that the target flatness for the flatness feedforward control
[0027] Page 6, or the flatness control for rolling the metal strip in step g) is calculated by the transfer model in such a way that the metal strip does not exhibit the desired target flatness immediately after its rolling in step f), but only after its second processing, i.e., in step I). At this point, the metal strip is finally fully formed; that is, the metal strip is then the final product. With the changed target flatness at the input of step h), the control signal at the output of step h) naturally also changes appropriately.
[0028] The ultimate target specification for the flatness of the metal strip can be further improved by the transfer model not only generating and outputting the target flatness for the flatness feedforward control or the flatness control, but also outputting further specifications for other influencing factors on the rolling step f), which are then applied directly to the rolling step f) - not necessarily via the feedforward control or control according to step h).
[0029] An even better way to more accurately achieve the target flatness of the final product is to measure the actual flatness of the metal strip after rolling step f), preferably after the second processing step in process step I), and compare it with the target flatness value at the start of step h). If a flatness deviation is still detected, the method according to the invention provides that this flatness deviation is transmitted to a higher-level production planning system, which can then decide whether this flatness deviation should be further reduced, e.g., by performing a subsequent processing step, such as stretch bending, on the metal strip depending on the detected flatness deviation, so that the metal strip ultimately achieves the required flatness. Alternatively, the higher-level flatness system can also decide to process the metal strip with
[0030] Page 7 of the remaining flatness deviation to be assigned to another suitable order.
[0031] If no (first) flatness measuring device is available immediately before the first processing of the metal strip prior to its rolling, the actual flatness of the metal strip required according to process step a) for carrying out the inventive method can also be determined by an upstream process step a-1) before the first processing of the metal strip and provided by this process step.
[0032] The execution of the method according to the invention can advantageously be facilitated and simplified by using historical strip data for determining the change in flatness, the target flatness and optionally for determining other influencing factors or control signals for the rolling step in the case of new or future metal strips.
[0033] The aforementioned problem of the invention is further solved by a device for rolling a metal strip according to claim 10. The advantages of this solution correspond to the advantages previously mentioned with reference to the claimed method.
[0034] Further advantageous embodiments of the method and device according to the invention are the subject of the dependent claims.
[0035] The description includes eight figures, whereby
[0036] Figure 1 shows the device and method according to the invention in a first embodiment (flatness feedforward control);
[0037] Page 8, Figure 2 shows an example of the first processing device;
[0038] Figure 3 shows an example of the second processing unit:
[0039] Figure 4 shows the device according to the invention and the method according to a second embodiment (flatness control);
[0040] Figure 5 shows the device and method according to a third embodiment;
[0041] Figure 6 shows the device and method according to a fourth embodiment;
[0042] Figure 7 shows the device and method according to the invention in a fifth embodiment; and
[0043] Figure 8 shows the device and method according to a sixth embodiment according to the invention.
[0044] illustrated.
[0045] The invention is described in detail below with reference to the figures mentioned, in the form of exemplary embodiments. In all figures, identical technical elements are designated by the same reference numerals. Where individual elements are not designated or described in individual figures, the designation and description as given in other figures apply to these elements.
[0046] Figure 1 illustrates the device 100 according to the invention and the method according to the invention for rolling a metal strip 10. The device
[0047] Page 9 shows a first flatness measuring device 110 for determining the actual flatness Pv(xo) of the metal strip 10 at its length position xo according to a process step a) before a subsequent first processing of the metal strip with a first processing device U1.
[0048] Figure 2 illustrates that the first processing step can be, for example, a rewinding process in which the metal strip 10 is first wound onto a reel 120 according to process step b). Figure 2 also shows an unwinder 130, with which the previously wound metal strip 10 is unwound again (step c). The reel 120 and the unwinder 130 can be designed separately, as shown in Figure 2. In this case, the metal strip 10 wound into a coil on the reel 120 must be transferred to the unwinder 130 for processing. Alternatively, the reel 120 and the unwinder 130 can also be designed as a single first processing unit U1, which can be operated both as a reel and as an unwinder for the metal strip 10.
[0049] Fig. 1 further shows a downstream second flatness measuring device 140, which is passed through by the unwound metal strip 10 to determine the actual flatness Pn(x0) of the metal strip at the length position xo immediately after the first processing, step d).
[0050] The actual flatness Pv(xo) previously determined using the first flatness measuring device 110 according to process step a) is temporarily stored in a data storage (data buffer) 115. As soon as the actual flatness Pn(xo) of the metal strip 10 at length position xo, measured using the second flatness measuring device 140, is available, it is transmitted together with the temporarily stored actual flatness Pv(xo) to a calculation device 150 to perform any position-synchronous adjustments that may have occurred during processing within the first processing device U1.
[0051] Page 10 Calculate the change in flatness AP(xo) at length position xo, step e). This change in flatness is calculated as the difference between the determined actual flatness Pv(xo) of the metal strip 10 before the first processing unit U1, and the actual flatness Pn(xo) immediately downstream / after / after the first processing unit U1.
[0052] The flatness change AP( xo) is fed as an input variable to a transfer model 170, step g), to determine a target flatness for the metal strip after its rolling in step f) at its length position xo. In Figure 1, this rolling is illustrated by a rolling stand 160. In addition to the aforementioned flatness change AP, the transfer model 170 also receives the properties UT, U1", U2', U2" of the metal strip before and after the first and / or second processing by the first and / or second processing unit U1, U2, as well as a target specification ZV(xo) for the flatness of the metal strip at length position xo after its rolling according to step f). The differences between the properties of the metal strip before and after the first and / or second processing include, for example, changes in tensile stress, changes in thickness, and / or changes in the temperature of the metal strip 10.The transfer model in this context consists of a model describing the winding process. The winding model describes the change in flatness during the winding and unwinding of a strip under tension. Adaptation parameters are used to adjust the model to the measured changes in flatness. These adaptation parameters describe the transfer of, for example, the thickness profile of the metal strip to the stress distribution in the width direction of the metal strip. The adaptation parameters are determined using the base data before processing (UT, U1) and the measured change in flatness. Then, using the determined adaptation parameters and the base data after processing (U2', U2"), the change in flatness during winding and unwinding after processing is calculated. This change is determined by the target flatness specification.
[0053] Page 11: Delivery condition subtracted, resulting in the target specification for flatness in the current rolling process.
[0054] The target flatness SP(xo) determined in this way serves as an input variable for a flatness feedforward control (first embodiment according to Fig. 1), or a flatness control 180 (second embodiment according to Fig. 4), which alternatively directly influences the setting of the rolling stand 160 by generating a control signal St in order to influence the rolling process, step f), so that the desired target flatness is achieved at the output of the rolling stand 160 or at the output of the second processing unit U2 on the metal strip 10.
[0055] In the case of flatness control, see Fig. 4, this system receives not only the target flatness but also a determined actual flatness as a feedback signal from a third flatness measuring device 190 downstream of the rolling stand, as described above. The adjustment is achieved by appropriately controlling at least one flatness actuator of the rolling stand with the control signal St, as illustrated in Figures 1 and 4. For example, in the case of the rolling stand 160 with the work rolls 165, the flatness feedforward control or the flatness control 180 can control at least one of the following flatness actuators of the rolling stand 160:
[0056] - Bending cylinder for bending the work rollers,
[0057] - a displacement device for axially displacing the work rolls 165, in particular Continuous Variable Crown (CVC) work rolls and / or
[0058] - a setting device for setting the work rollers 165, i.e.
[0059] to align the work rollers so that their longitudinal axis is not at an angle of 90° to the longitudinal axis of the rolled metal strip.
[0060] Page 12. As mentioned, the target flatness SP(xo) relates to the flatness of the metal strip 10 directly at the exit of the rolling stand 160. Therefore, the target flatness SP should correspond to the target specification ZV for the flatness of the metal strip at length position xo after its rolling according to process step f).
[0061] However, if the metal strip 10 is subjected to a second processing operation, for example a second rewinding operation, by a second processing device U2 after its rolling according to step f), whereby the flatness of the metal strip may be affected, it is recommended that the target flatness SP in process step g) be calculated by the transfer model 170 in such a way that the actual flatness of the metal strip 10 after the second processing has the desired target flatness ZV(xo).
[0062] Figure 3 illustrates a possible embodiment for the second processing unit U2, here also in the form of a rewinding unit. In this unit, the metal strip 10 is first wound up after rolling in process step f) according to process step i), and subsequently unwound again in process step j). If the second processing unit U2 is also a rewinding unit, the above description for the first processing unit U1 applies analogously.
[0063] Between process steps f) and i), the flatness of the metal strip 10 is measured using the said third flatness measuring device 190, step k).
[0064] Downstream of the second processing unit U2, the flatness of the metal strip 10 can be determined again using a fourth flatness measuring device 210 (process step I). The actual flatness determined by the fourth flatness measuring device 210 should then preferably correspond to the desired target flatness ZV(xo). The target flatness SP(xo) calculated in step g), which, as mentioned, refers to the flatness of the metal strip 10 immediately behind the rolling stand 160, then does not correspond to the target specification for the flatness behind the
[0065] Page 13 of the fourth measuring device 210, because in the meantime the second processing of the metal strip takes place in the second processing device U2, which is generally not without influence on the flatness of the metal strip. In any case, the target flatness SP(xo) of the transfer model 170 must be calculated in such a way that, taking into account the second processing that may take place after process step f), the desired target specification ZV(xo) is ultimately achieved. For this, it is important to know or be able to predict the forming behavior of the second processing device U2 and its influence on the flatness of the metal strip 10.
[0066] For this purpose, the actual flatness AP of the metal strip 10 after rolling step f) or after the second processing step is measured at length position xo of the metal strip in process step k) using a third and / or fourth flatness measuring device 190, 210 and compared in step g) with a target value ZV (xo) (not shown in the figures) in order to determine any remaining flatness deviation at the exit of the rolling stand 160. Furthermore, the properties U2', U2" of the metal strip 10 before and after the second processing device U2 are determined and fed back to step g) to be taken into account in the calculation of the target flatness for the flatness feedforward control or control.
[0067] Any flatness deviation detected downstream of the second processing unit U2 can also be transmitted to a higher-level production planning system, which may then specify further subsequent processing steps, e.g., stretch bending, after rolling according to step f) or downstream of the second processing unit U2, depending on the detected flatness deviation. In this way, the ultimately planned target specification ZV(x0) for the metal strip 10 as the final product can be achieved even more effectively.
[0068] Page 14, Figure 5 shows the device 100 according to Figure 1, wherein the transfer model 170 is further extended by an online adaptation (3rd embodiment). For this purpose, preferably all relevant parameters of the metal strip 10, even if it is wound into a coil, as well as preferably all relevant process parameters together with at least some of the actual flatness of the metal strip 10 measured in the flatness measuring devices 110, 140, 190 and / or 210, are first collected as historical strip data in a database 9 and stored there, preferably classified. An optimization module 11 optimizes empirical setting parameters for the adjustment of the transfer model 170 by referring to this historical strip data. The empirical setting parameters are, for example, temperature or...Heat transfer coefficients to determine the creep behavior of the metal strips and / or plasticization coefficients, for example coefficients of friction.
[0069] The empirical parameters thus optimized are then provided at the output of the optimization module 11 and transferred to the transfer model 170 in order to optimize or adapt the model parameters of an empirical and / or physical model that is part of the transfer model 170 with regard to the current process situation and the current properties of the metal strip.
[0070] This measure also serves to improve the calculation of the target flatness SP(xo) by the transfer model 170 with regard to a more precise achievement of the target specification ZV(xo) for the flatness of the metal strip.
[0071] Figure 6 shows a fourth embodiment of the device and method according to the invention, for the case where it is not possible to determine the actual flatness Pv(xo) using the first flatness measuring device 110. In this case, the alternative possibility exists that the actual flatness Pv(xo) necessary for carrying out the method according to the invention can be determined at length position xo before the first machining operation in a previous step.
[0072] Page 15 process step a-1 ), e.g. a pickling process, is determined and made available for the process according to the invention; see the dashed connecting line between block a-1 ) and memory 115.
[0073] A further measure to improve the calculation of the influencing factors with regard to a more accurate achievement of the target ZV(xo) can be achieved by carrying out the following steps (fifth embodiment); see Figure 7:
[0074] i) -ii) Assigning the (historical) metal band to a specific classified band type;
[0075] iii) Storing the actual flatness of the (historical) metal strip 10 at length position xo, determined by the flatness measuring device 190 directly at the exit of the rolling mill 160, the properties of the metal strip before and after its second processing by the second processing device U2 and / or the actual flatness of the metal strip at the exit of the second processing device U2 measured by the fourth flatness measuring device 210, each together with the assigned strip type, in a database 14 as historical strip data, i.e. as strip data of the historical metal strip;
[0076] before rolling a different metal strip that will be formed in the future:
[0077] iv) Check whether the metal strip to be reshaped in the future belongs to the same strip type as the previously reshaped (historical) metal strip for which steps ii) and iii) were carried out; and if so:
[0078] v) Extracting the actual flatness before and after the first processing of the metal strip from the historical strip data and determining from this, according to step e), a historical flatness change APh, or
[0079] v') Extracting the historical flatness change APh directly from the historical tape data;
[0080] vi) Extracting the differences AUh in the properties of the historical metal band from the historical band data in database 14;
[0081] Page 16vii) Carrying out the process steps f) to h) on the metal strip to be formed in the future, wherein in step g) the historical flatness change APh(xo) of the same strip type, the historical differences AUh and a target specification ZV(xO) for the metal strip to be formed in the future are supplied to the transfer model 170.
[0082] The execution of procedural steps ii) to vi) is not contingent upon the prior execution of the previously described procedural step i), but can be carried out independently. The designation of the steps with Roman numerals ii) to vi) is merely a list.
[0083] The term "historical" serves only to better distinguish it from the metal strip to be formed in the future. Therefore, the historical metal strip could also be a currently rolled metal strip.
[0084] The classification of the tape type is based on at least one of the following data stored in database 14:
[0085] - bandwidth
[0086] - Band thickness
[0087] - Strength of the band
[0088] - Strip tension during processing in the rolling process
[0089] - Strip tension during processing in the rolling process
[0090] - winding processes took place between rollers and measuring device
[0091] - Band temperature during processing
[0092] - Cooling time between rolling and measuring
[0093] - Strip temperature difference between processing and measurement
[0094] - Ambient temperature
[0095] - Band thickness profile across the width
[0096] - Strip flatness measured during the rolling process before processing
[0097] - Band module
[0098] Page 17 - Scaffolding module
[0099] - Information on upstream processing processes
[0100] - Information on downstream processing
[0101] - Origin of the tape (manufacturer's information)
[0102] - Material recognition
[0103] - Chemical composition
[0104] - Emulsion temperature
[0105] - Roll gap temperature
[0106] Finally, Figure 8 shows that the method according to the invention can also be carried out during reversible rolling of the metal strip 10 using a reversible rolling mill 230 (sixth embodiment). This mill comprises the first processing unit U1, here in the form of a first rewinding unit with the winding reel 120 and the unwinding reel 130, the second flatness measuring unit 140, the rolling stand 160 in the form of a reversible rolling stand, the third flatness measuring unit 190, and the second processing unit U2, here in the form of a second rewinding unit. The metal strip 10 is rolled reversibly with the reversible rolling mill 230, as indicated by the double arrows in Figure 8. The flatness measuring units 140 and 190 are designed to each detect the actual flatness as the metal strip passes through in both directions.This is also symbolically indicated in Figure 8 by the fact that two measurement signals each originate from the flatness measuring devices 140, 190. One of these signals represents the actual flatness of the metal strip Pv(xo) before it reaches the respective processing unit U1, U2, and the other represents the actual flatness Pn(xo) of the metal strip after it exits the respective processing unit U1, U2. The actual flatness values Pv before the respective processing unit are temporarily stored in the data memory 115 until the respective actual flatness value Pn after leaving the respective processing unit is also available. The two actual flatness values Pv and Pn are then fed to the calculation unit 150.
[0107] Page 18 to calculate the position-synchronous flatness change AP according to procedure step e), as described in detail above with reference to the other embodiments.
[0108] Analogous to the flatness measuring device 140, the flatness measuring device 190 also generates a signal for the actual flatness values Pv(xo) and Pn(xo) of the metal strip before it enters the second processing unit U2 and after it leaves the second processing unit U2. These signals, as soon as they are both available, are also fed to the calculation unit 150 so that it can calculate the position-synchronous flatness change AP(xo) according to step e). Depending on which flatness measuring device 140 or 190 the length position xo of the metal strip 10 is currently located at, either the actual flatness values from one or the other flatness measuring device 140 or 190 are fed to the calculation unit 150. The corresponding selection of the signals for the actual flatness values is made via the switching device 220 in response to the detected position of the length position xo of the metal strip.When this length position xo is located at the flatness measuring device 140, its actual flatness values Pv(xo), Pn(xo) are passed through to the calculation device 150; the switches of the switching device 220 are then both in the horizontal position. Conversely, when the length position xo of the metal strip 10 is located at the flatness measuring device 190, its actual flatness signals Pv, Pn are passed through to the calculation device 150; the switches of the switching device 220 are then both in the vertical position.
[0109] Otherwise, process steps g) and h) are carried out in the same way during reversing rolling as described above with reference to Figures 1 to 4.
[0110] Due to its dual function, it can be said that the second measuring device 140 in Figure 8, in addition to its original function, i.e., the
[0111] Page 19: Determining the actual flatness Pn(xO) of the metal strip as it moves towards the rolling stand 160, also performs the function of the first flatness measuring device 110, namely determining the actual flatness Pv(xO) as the metal strip moves towards the first processing device U1. The same applies to the third measuring device 190, which also performs the function of the fourth flatness measuring device 210 according to Figure 2.
[0112] All previously described embodiments (first to fifth) also apply analogously to the reversing system according to Fig. 8.
[0113] Page 20 Reference Mark List
[0114] 9 Database
[0115] 10 metal band
[0116] 11 Optimization module
[0117] 12. Actual flatness of metal strips before processing as historical strip data
[0118] 13 Actual flatness of metal strips after their processing as historical strip data
[0119] 14 Database
[0120] 100 Device
[0121] 110 first flatness measuring device
[0122] 115 Data storage
[0123] 120 winding reel
[0124] 130 Unwind reel
[0125] 120, 130 first processing unit
[0126] 140 second flatness measuring device
[0127] 150 Calculation device
[0128] 160 Forming equipment, in particular rolling mill
[0129] 165 working rollers
[0130] 170 Transfer model
[0131] 180 Flatness feedforward control or flatness control
[0132] 190 third flatness measuring device
[0133] 210 fourth flatness measuring device
[0134] 220 switching device
[0135] 230 reversing rolling mill
[0136] AP flatness change
[0137] APh historical flatness change
[0138] Page 21Pn Actual flatness of the metal strip after machining Pv Actual flatness of the metal strip before machining
[0139] SP Target Flatness
[0140] U1 first processing unit
[0141] U2 second processing unit
[0142] U1 ' Properties of the metal strip before its first processing U1 “ Properties of the metal strip immediately after its first processing
[0143] U2' Properties of the metal strip before its second processing U2" Properties of the metal strip immediately after its second processing
[0144] AU differences
[0145] Oh, historical differences!
[0146] xo Length position of the metal band
[0147] ZV target
[0148] St control signal for flatness actuator
[0149] Page 22
Claims
Patent claims:
1. Method for rolling a metal strip (10), comprising the following steps: a) Determining the actual flatness (Pv(xO) of the metal strip (10) at a length position (xo) b) first processing of the metal strip (10) immediately after determining its flatness; c) - d) Determining the actual flatness (Pn(x0) of the metal strip (10) at the length position (xo) immediately after the first processing; e) Determining a position-synchronous change in flatness (AP(x0)) of the metal strip caused by the first processing as the difference between the determined actual flatness (Pn(x0)) before the first processing and the actual flatness (Pv(xO)) after the first processing of the metal strip, each at the same length position (xo) of the metal strip; f) Rolling the processed metal strip, influencing the flatness of the metal strip (10); g) Determining a value for the target flatness of the metal strip (10) for a flatness feedforward control or a flatness control for the rolling of the metal strip according to step f) using a transfer model (170) based on the properties (UT, U1") of the metal strip before and after the first processing, based on the determined flatness change (AP(x0)), based on a target specification (ZV(xo)) for the flatness of the metal strip (10) at the length position (xo) after its rolling according to step f) and after a second processing (U2), and / or based on the properties (U2', U2") of the metal strip before and after the second processing; h) Performing flatness pre-control or flatness control (180) for the metal strip (10) with the target flatness determined by the transfer model (170), generating a manipulated variable (St) to influence the rolling step f). Page 232. Method according to claim 1 , characterized by that according to step h) the actual flatness of the metal strip (10) determined in step a) or a-1) is pre-controlled or regulated to the target flatness (SP) by suitable control of flatness actuators of a rolling stand during the rolling step f).
3. Method according to claim 2, characterized by that the target flatness (SP(xO)) corresponds to the target specification (ZV(xO)) for flatness of the metal strip immediately after its rolling according to step f).
4. Method according to claim 2, characterized by that the metal strip (10) is processed again by a second processing unit (U2) after its rolling according to step f); and that the target flatness SP in step g) of the transfer model (170) is calculated such that the actual flatness of the metal strip (10) after its second processing has the desired target flatness (ZV(xo)).
5. Method according to any of the preceding claims, characterized by that after the rolling step f) or after the second processing step, the actual flatness of the metal strip (10) is measured and compared with the target specification (ZV(xo)) in order to determine any possible flatness deviation; that the flatness deviation thus determined is transmitted to a higher-level production planning system to provide for at least one further subsequent processing step, e.g. a stretch bending step, for the metal strip (10) depending on the Page 24 identified deviation from flatness.
6. Method according to any of the preceding claims, characterized by that the actual flatness of the metal strip (10) according to step a) is determined in a process step (a-1), e.g. a pickling process, before the first processing and is provided by this process step.
7. A method according to any of the preceding claims, characterized by the following steps: ii)) Assigning the metal band to a specific classified band type; iii) Storing the actual flatness of the metal strip (10) at the length position (xo) determined in steps a) or a-1) and d) immediately before and after its first processing and / or the flatness change determined in step e), together with the assigned strip type, in a database (14) as historical strip data; before rolling a metal strip to be formed in the future: iv) Check whether the metal strip to be reshaped in the future belongs to the same strip type; and if so: v) Extracting the actual flatness before and after processing the metal strip from the historical strip data and determining from this, according to step e), a historical flatness change (APh) or v') Extracting the historical flatness change directly from the historical band data; vi) Extracting the historical differences AUh from the historical band data in database 14; and vii) Performing process steps f) to h) on the metal strip to be reshaped in the future, wherein in step g) the historical flatness change APh of the same strip type is transferred to the transfer model 170. Page 25 historical differences AUh and a target value ZV(xO) for the metal strip to be formed in the future are supplied.
8. Method according to claim 7, characterized by that the classification of the band type is based on at least one of the following data stored in the database (14): - bandwidth - Band thickness - Strength of the band - Strip tension during processing in the rolling process - winding processes took place between rollers and measuring device - Band temperature during processing - Cooling time between rolling and measuring - Strip temperature difference between processing and measurement - Ambient temperature - Band thickness profile across the width - Strip flatness measured during the rolling process before processing - Strip module - Scaffolding module - Information on upstream processing processes - Information on downstream processing - Origin of the tape (manufacturer's information) - Material recognition - Chemical composition - Emulsion temperature - Roll gap temperature 9. Method according to any one of the preceding claims, characterized in that that the procedure is carried out during a reversing Page 26 Rolling of the metal strip (10) with a reversing rolling stand.
10. Device (100) for rolling a metal strip (10) comprising: a first flatness measuring device (110) for determining the actual flatness at a length position (xo) of the metal strip (10) before initial processing; a processing device (120, 130) for the initial processing of the metal strip (10) immediately downstream of the first flatness measuring device (110); a second flatness measuring device (140) for determining the actual flatness of the metal strip (10) at the length position (xo) immediately downstream of the first processing device (U1); a calculation device (150) for determining the position-synchronous change in flatness of the metal strip (10) caused by processing within the processing device (U1) as the difference between the determined actual flatness Pv(xo) upstream of the processing device and the actual flatness Pn(xo) immediately downstream of the processing device, each at the length position (xo); a rolling stand (160) for rolling the unwound metal strip (10), whereby the flatness of the metal strip (10) is influenced; a transfer model (170) for determining at least one influencing factor for the rolling stand based on properties (UT, U1") of the metal strip before and after the first processing, based on the determined flatness change based on a target specification (ZV(xo)) for the flatness of the metal strip (10) at the length position (xo) after its rolling, and / or based on the properties (U2', U2") of the metal strip (10) before and after a second processing; a flatness feedforward control or flatness control (180) for controlling or regulating the actual flatness of the metal strip (10) upstream of the first processing unit (U1) determined in step a) or a-1) to the target flatness (SP(xo)) by suitable control of at least Page 27 a flatness adjuster of the rolling stand (160).
11. Device according to claim 10, characterized by that the at least one flatness actuator of the rolling stand is one of the following actuators: bending cylinders for bending the work rolls; a shifting device for axially shifting the work rolls, in particular CVC work rolls; the adjusting cylinders of the rolling mill stand for adjusting the strip tension; and / or a setting device for setting the working rollers.
12. Device according to one of claims 10 or 11, characterized by that downstream of the rolling stand (160) a third flatness measuring device (190), a second processing device (U2) and a fourth flatness measuring device (210) are connected.
13. Device according to claim 12, characterized by that the first and / or second processing unit (U1, U2) is either a single reel unit that can be operated as both a winding reel and an unwinding reel for the metal strip (10), or a winding reel (120) and a separate unwinding reel (130), wherein the metal strip wound into a coil on the winding reel (120) can be transferred to the unwinding reel (130) for processing. Page 2814. Device according to claim 12 and / or 13, characterized by that the first processing unit (U1), the second flatness measuring unit (140), the rolling stand (160), the third flatness measuring unit (190) and the second processing unit (U2) together form a reversing rolling plant for reversing rolling, in particular cold rolling of the metal strip (10). Page 29