Rolling mill in which rolling depends on material properties

Abstract

To provide a rolling mill which has a rolling stand (1) in which a flat rolled product (2) made of metal is rolled.SOLUTION: A sensor device (6) for detecting at least one measurement variable (M) having a characteristic of a material property of a flat rolled product (2) is arranged on the upstream and / or the downstream of a rolling stand (1). The material property is especially the electromagnetic or mechanical property of the rolled product (2). The sensor device (6) transmits the detected measurement variable (M) to a control device (9) of a rolling mill. The control device (9) determines a control value (A) of the rolling stand (1) in consideration of the measurement variable (M). With the control of the rolling stand (1), the influence is given to the material property of the flat rolled product (2). The control value (A) is a ratio of circumferential speeds (vO, vU) of the rotation of upper and lower work rolls (3, 4) of the rolling stand (1).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The invention relates to a rolling mill having a first rolling stand for rolling flat rolled products made of metal, - a sensor device is arranged upstream and / or downstream of the first rolling stand, - the sensor device is connected to a control device of the rolling mill for transmitting the detected measured variables, - the control device is designed to take into account the transmitted measured variables in a situation where it determines control values for the first rolling stand, - the sensor device is designed such that at least one measured variable specific to the material properties of the flat rolled product can be detected, - by controlling the first rolling stand with the control values, the material properties of the flat rolled product are influenced, - the first rolling stand starts from a rolling mill having an upper work roll and a lower work roll.

[0002] In the context of the present invention, the term "first rolling stand" is not intended to mean that a rolling mill necessarily has a plurality of rolling stands and that the first rolling stand is the foremost rolling stand through which a flat rolled product first passes. Rather, it is intended to include, first, the case where the rolling mill has only a first rolling stand. In this case, only the first rolling stand exists. Moreover, when the rolling mill has a plurality of rolling stands, the term "first rolling stand" merely serves to distinguish it from the other rolling stands of the rolling mill. On the other hand, there is no intended implied order. Thus, even in this case, the first rolling stand can be located at any position among a series of rolling stands of the rolling mill. Thus, by way of example only, if a flat rolled product first passes through rolling stand A, then through rolling stand B, then through rolling stand C, and finally through rolling stand D, the first rolling stand can be any one of rolling stands A to D, and the other rolling stands can be the second rolling stand.

[0003] In the production of a flat rolled product, it is an object to set the geometric characteristics of the flat rolled product, in particular, its width and thickness, as precisely as possible. This also applies to the contour or outer shape. Flatness should also be maintained. In addition to these and possibly other geometric characteristics, the material characteristics of the flat rolled product should also be set. The material characteristics are the characteristics that the flat rolled product should have, for example, a specific yield strength, a specific material hardness, or a specific magnetic permeability during later use. Therefore, the material characteristics are characteristics that are not related to the particular current state of the material (e.g., temperature) and are also not related to its geometric characteristics. The reason why specific material characteristics are detached from the material itself is that the metal has a granular structure.

[0004] The material properties can be set, at least in part, during the rolling of flat rolled products. However, there is often a difference between the actual value and the desired target value of the material properties. In this case, it is necessary to heat-treat the flat rolled product after hot rolling. This is particularly true when it is necessary to establish a "Goss texture" in the rolled product. However, the same problem is also faced in the case of certain steels, especially AHSS (advanced high strength steel), as well as martensite grades and bainite grades. In the case of heat treatment, the rolled product can be cooled in a suitable manner in the cooling zone after hot rolling, for example, to set the material properties, or in the case of cold rolling, it can be processed in an annealing step. Alternatively, this treatment can be carried out after cold rolling or between two cold rolling steps.

Background Art

[0005] It is known from Non-Patent Document 1 that "asymmetric" rolling can be advantageous for establishing the texture of a rolled product that is favorable for magnetization. In asymmetric rolling, the peripheral speeds of the upper and lower work rolls of the rolling stand are different from each other. Therefore, during rolling, a shear force acts on the flat rolled product in the conveying direction. Due to the shear force, the rearrangement of crystal orientations is carried out.

[0006] A rolling mill of the type described at the beginning is known, for example, from Patent Document 1. In this rolling mill, for example, the pass reduction or the rolling force is adjusted using a control value.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Non-Patent Documents

[0008]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] An object of the present invention is to provide a way to enable selective adjustment of the electrical, magnetic, or mechanical material properties of flat rolled products in a simple and reliable manner as needed.

Means for Solving the Problems

[0010] This object is achieved by using a rolling mill having the features of claim 1. Advantageous improvements of this rolling mill form the subject matter of dependent claims 2 to 15.

[0011] According to the present invention, in a rolling mill of the type described at the beginning, the control device is designed such that the control value determined taking into account the measured variables is the ratio of the upper peripheral speed at which the upper work roll rotates to the lower peripheral speed at which the lower work roll rotates.

[0012] Therefore, measured variables that can directly determine the corresponding material properties of the flat rolled product at the time of measurement are detected. Therefore, there is a direct functional relationship between one measured variable and the other material property. In contrast, complex model calculations do not need to be performed, and thereby, for example, the development over time can be modeled.

[0013] In this case, the phrase "at the point in time of measurement" is not intended to imply that the state of the flat rolled product, and thus the material properties as well, necessarily continue to change over time due to changes in its temperature, for example. However, the material properties can be set to different values using the corresponding processing of the rolled product, for example, by rolling in the first rolling stand or in any other rolling stand, or by using a heat treatment at a later point in time.

[0014] The rolling mill can have only the first rolling stand described above and, as a result, can have only a single rolling stand. In this case, the sensor device is arranged entirely either immediately upstream or immediately downstream of the rolling stand itself. However, this rolling mill can similarly have at least one second rolling stand in addition to the first rolling stand. In this case, several different embodiments are possible.

[0015] Thus, for example, it is possible that the second rolling stand is not arranged between the sensor device and the first rolling stand. This embodiment is realized, for example, when the sensor device is arranged upstream of the foremost rolling stand of a multistand rolling train and the control value determined by the control device taking into account the measured variables acts on the foremost rolling stand, or vice versa, when the sensor assembly is arranged downstream of the last rolling stand of a multistand rolling train and the control value determined by the control device taking into account the measured variables acts on the last rolling stand. Similarly, this embodiment is realized, for example, when the sensor assembly is arranged between two rolling stands of a multistand rolling train and the control value determined by the control device taking into account the measured variables acts on one of these two rolling stands, or when the control device determines two such control values and each control value acts on each of these two rolling stands.

[0016] Alternatively, at least one of the second rolling stands may be arranged between the sensor device and the first rolling stand. This embodiment is realized, for example, when the sensor device is arranged upstream of the foremost rolling stand of a multi-stand rolling train and the control values determined by the control device taking into account the measured variables act on rolling stands other than the foremost rolling stand, or vice versa, when the sensor assembly is arranged downstream of the last rolling stand of a multi-stand rolling train and the control values determined by the control device taking into account the measured variables act on rolling stands other than the last rolling stand.

[0017] Of course, combinations of these methods are also possible. Thus, for example, the sensor device may be arranged upstream of the foremost rolling stand of a multi-stand rolling train, and a plurality of control values, one acting on the forward rolling stand and the other acting on another rolling stand, may be determined by the control device taking into account the measured variables. Conversely, similarly, the sensor assembly may be arranged downstream of the last rolling stand of a multi-stand rolling train, and furthermore, a plurality of control values, one acting on the last rolling stand and the other acting on another rolling stand, may also be determined by the control device taking into account the measured variables.

[0018] Preferably, the control device is designed such that the control device determines the ratio of the upper peripheral speed to the lower peripheral speed to be between 0.5 and 2.0, in particular between 0.9 and 1.1. Thereby, all actually relevant cases can be covered.

[0019] In order to be able to implement different peripheral speeds, it is possible to drive the upper work roll by an upper drive and the lower work roll by a lower drive different from the upper drive. In this case, the different peripheral speeds can be implemented simply by corresponding the settings of the two drives to different speeds.

[0020] Alternatively, it is possible to drive the upper work roll and the lower work roll by a common drive unit. In this case, a transmission is arranged between the common drive unit on one side and the upper work roll and the lower work roll on the other side, which can continuously adjust the ratio of the speed of the upper output shaft connected so as to rotate conjointly with the upper work roll to the speed of the lower output shaft connected so as to rotate conjointly with the lower work roll.

[0021] In addition to setting the ratio of the peripheral speeds to each other, the control device can be designed such that the control value determined taking into account the measured variables is a change in the temperature of the flat rolled product before rolling in the upper work roll and / or the lower work roll of the first rolling stand and / or in the first rolling stand. For example, cooling can be performed by spraying on water, or heating can be performed by induction heating.

[0022] When the sensor device is arranged upstream of the first rolling stand, preferably, the control device is designed to output the control value determined taking into account the measured variables to the first rolling stand taking into account the path of the flat rolled product from the sensor device to the first rolling stand. Therefore, when controlling the first rolling stand, the control device takes into account the transport time elapsed between the detection of the measured variables for a specific section of the flat rolled product and the rolling of the same section of the flat rolled product in the first rolling stand.

[0023] Preferably, the control device includes a model, and using this model, the control device determines the control value of the first rolling stand taking into account the measured variables, and further determines a predicted value of the material properties of the flat rolled product after rolling in the first rolling stand taking into account the control value determined taking into account the measured variables. More preferably, a further sensor device capable of detecting at least one further measured variable specific to the material properties of the flat rolled product after rolling in the first rolling stand is arranged downstream of the first rolling stand. The further sensor device is connected to the control device and transmits the detected further measured variables. Finally, the control device is preferably designed in such a way that at the time when the control device determines taking into account the path of the flat rolled product from the first rolling stand to the further sensor device, the control device uses the further measured variables and adapts the model based on the comparison between the further measured variables and the predicted values of the material properties. Using this procedure, the model can gradually fit better to the actual behavior of the flat rolled product.

[0024] Preferably, when determining the control value, the control device is designed to take into account, in addition to the transmitted measured variables, the temperature of the flat rolled product before rolling in the first rolling stand, and / or the rolling force during rolling of the flat rolled product in the first rolling stand, and / or the pass reduction during rolling of the flat rolled product in the first rolling stand. Thereby, it is possible to set the desired material properties with higher accuracy. The required dependencies can be stored in the control device, for example, in the form of a feature map.

[0025] In a preferred embodiment, the sensor device comprises an excitation element and a first sensor element. A base signal is excited in the flat rolled product by the excitation element. A first sensor signal based on the excited base signal is detected by the first sensor element. The sensor device can determine the transmitted measured variables taking into account the first sensor signal. Alternatively, it is possible for the transmitted measured variables to include the first sensor signal.

[0026] In individual cases, it may be possible to exclusively detect the first sensor signal. However, generally, the sensor device further includes several second sensor elements. In this case, when viewed in the transport direction from the first sensor element, each second sensor element is arranged offset upstream and / or downstream and / or laterally of the first sensor element. Each second sensor signal of the same type as the first sensor signal based on the excited base signal is detected by each second sensor element. The sensor device can determine the transmitted measurement variable while also taking into account each second sensor signal. For example, the difference or ratio of the corresponding sensor signals can be formed. Alternatively, the transmitted measurement variable can also include each second sensor signal. In this case, a similar evaluation can be performed by the control device.

[0027] The base signal can be, for example, an eddy current. Alternatively, the base signal can be an acoustic signal, in particular an ultrasonic signal.

[0028] The connecting line from the excitation element to the first sensor element preferably extends parallel to the transport direction. As a result, this particularly provides a reliable evaluation.

[0029] As already mentioned, the material properties can be the electromagnetic or mechanical properties of the rolled product.

[0030] In individual cases, hot rolling may be performed. However, generally, cold rolling is performed. Therefore, the rolling mill is generally a cold rolling mill.

[0031] The above-mentioned characteristics, features, and advantages of the present invention, as well as the manner in which they are achieved, will be more clearly and distinctly understood in conjunction with the following description of exemplary embodiments, which will be described in more detail in combination with the drawings.

Brief Description of the Drawings

[0032]

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Mode for Carrying Out the Invention

[0033] According to FIG. 1, like any rolling mill, the rolling mill has at least one first rolling stand 1. The first rolling stand 1 is used to roll a flat rolled product 2 composed of metal, especially a strip. In particular, the metal constituting the flat rolled product 2 can be steel or aluminum. In the case of steel, the flat rolled product can be, in particular, an electrical steel sheet with a relatively high silicon ratio (usually between 2% and 4%).

[0034] The rolling can be hot rolling. In this case, the rolling mill is a hot rolling mill. However, generally, cold rolling is included. In this case, the rolling mill is a cold rolling mill.

[0035] Regarding the first rolling stand 1 in FIG. 1 and other figures, only the upper work roll 3 and the lower work roll 4 are shown. However, generally, the first rolling stand 1 further has additional rolls. For example, in the case of a four-high stand, in addition to the work rolls 3, 4, support rolls, and in the case of a six-high stand, in addition to the work rolls 3, 4 and support rolls, it further has intermediate rolls arranged between the work rolls 3, 4 and the support rolls. Other configurations, such as a "twenty-high roll" rolling stand, are also possible. Regardless of the specific embodiment, the upper work roll 3 rotates at an upper peripheral speed vO, while the lower work roll 4 rotates at a lower peripheral speed vU. Both the upper and lower peripheral speeds vO and vU are greater than 0.

[0036] According to the illustration in FIG. 1, the rolling mill is designed as a reversing rolling mill. Therefore, this rolling mill has respective coilers 5 for winding up the flat rolled product 2 upstream and downstream of the first rolling stand 1. Regarding the first rolling stand 1, the terms "upstream" and "downstream" should always be considered with respect to the conveying direction x in which the flat rolled product 2 is rolled in the first rolling stand 1. Therefore, in a reversing rolling mill, the terms "upstream" and "downstream" are defined only in each rolling pass and are reversed in each subsequent rolling pass.

[0037] A sensor device 6 is arranged downstream of the first rolling stand 1. Using the sensor device 6, a measurement variable M can be detected. The detected measurement variable M is specific to the material properties of the flat rolled product 2. Examples of such properties are the conductivity, relative permeability, and magnetic saturation of the rolled product 2, or more generally, electromagnetic properties. Further examples of material properties are the yield strength, yield point elongation, or more generally, mechanical properties of the rolled product 2. The aforementioned variables can be either non-directional (i.e., isotropic) or directional (i.e., anisotropic). The variables are all based on the granular structure of the metal constituting the rolled product 2 and, where applicable, the arrangement of the particles.

[0038] One possible embodiment of the sensor device 6 will be described below in conjunction with FIGS. 2 to 4. However, the present invention is not limited to this embodiment of the sensor device 6.

[0039] According to FIGS. 2 to 4, the sensor device 6 includes an excitation element 7. A base signal can be excited in the flat rolled product 2 by the excitation element 7. For example, according to the illustration in FIGS. 3 and 4, the excitation element 7 can be designed as a coil to which an excitation current IA is intermittently supplied, whereby an eddy current IW as a base signal is generated in the rolled product 2. FIG. 3 shows the sensor device 4 at the time when the excitation current IA is supplied to the excitation element 7.

[0040] The sensor device 6 further includes a first sensor element 8a. A first sensor signal Ia is detected by the first sensor element 8a. The detection of the first sensor signal Ia is performed after the excitation of the base signal, i.e., at a later point in time. At this later point in time, generally, there is no excited base signal. However, the previously excited base signal has not completely disappeared yet. The first sensor signal Ia is based on the excited base signal. For example, according to the illustrations in FIGS. 3 and 4, the first sensor element 8a can be designed as a coil. Therefore, due to the eddy current IW, a current is induced in the first sensor element 8a, thereby forming the first sensor signal Ia.

[0041] In FIGS. 2 to 4, the first sensor element 8a is shown as a different element from the excitation element 7. This is the normal case. In this case, the first sensor element 8a is arranged downstream of the excitation element 7 when viewed in the conveying direction x of the rolled product 2. In this case, the connection line from the excitation element 7 to the first sensor element 8a preferably extends parallel to the conveying direction x. However, in individual cases, the first sensor element 8a may also be the same as the excitation element 7. This embodiment may be possible especially when the period between the excitation of the base signal and the detection of the excited base signal is sufficiently short.

[0042] According to FIG. 1, the sensor device 6 is connected to a control device 9 for a rolling mill. By virtue of the sensor device 6 being connected to the control device 9, in particular, the detected measurement variable M can be transmitted to the control device 9. The transmitted measurement variable M can include the first sensor signal Ia. If the transmitted measurement variable M does not contain any further components at all, the transmitted measurement variable M may be identical to the first sensor signal Ia. Alternatively, in order to determine the measurement variable M, the sensor device 6 can first evaluate the first sensor signal Ia (and possibly further signals), and use the result of this evaluation as the measurement variable M. For example, the sensor device 6 can set the first sensor signal Ia with respect to the excitation signal IA, thereby determining the measurement variable M.

[0043] Often, the sensor device 6 comprises, in addition to the first sensor element 8a, several second sensor elements 8b - 8d. The second sensor elements 8b - 8d are different from the first sensor element 8a (and generally also different from the excitation element 7). When viewed from the excitation element 7, the second sensor elements 8b - 8d are generally arranged downstream of the excitation element 7, even though in individual cases they may be remote from the excitation element 7. Using the second sensor elements 8b - 8d, it is possible to detect second sensor signals Ib - Id. The second sensor signals Ib - Id are, likewise, of the same type as the first sensor signal Ia, based on the excited base signal IW. The second sensor signals Ib - Id are generally detected simultaneously with the first sensor signal Ia.

[0044] If the second sensor elements 8b - 8d are additionally present as well, the sensor device 6 can transmit, for example, all of the sensor signals Ia - Id together as the measurement variable M, that is to say, transmit both the first sensor signal Ia and the second sensor signals Ib - Id. In this case, the corresponding evaluation of the sensor signals Ia - Id is carried out by the control device 9. Alternatively, the evaluation of the sensor signals Ia - Id may be carried out (completely or partially) in advance by the sensor device 6, and the result of this evaluation can be transmitted as the measurement variable M.

[0045] Regarding the arrangement of the second sensor elements 8b to 8d with respect to the first sensor element 8a, various arrangements and embodiments are possible.

[0046] For example, when viewed in the transport direction x, the sensor device 6 can have second sensor elements 8b, 8c that are arranged offset laterally from the first sensor element 8a. In this case, the sensor device 6 can set the first sensor signal Ic in relation to the second sensor signal Ib, thereby determining the measurement variable M. In this case, in particular, the measurement variable M can be determined from the difference or ratio of the sensor signals Ia, Ib, Ic. As illustrated in FIG. 2, when there are respective second sensor elements 8b, 8c on each of the two sides of the first sensor element 8a, the sensor device 6 can set the first sensor signal Ia in relation to the average value of these two second sensor signals Ib, Ic.

[0047] As an alternative or in addition, the sensor device 6 can have a second sensor element 8d that is arranged upstream or downstream of the first sensor element 8a when viewed in the transport direction x from the first sensor element 8a. In this case, it is normal for it to be arranged downstream of the first sensor element 8a. Even when the second sensor element 8d is arranged upstream or downstream of the first sensor element 8a, the sensor device 6 can set the first sensor signal Ia in relation to the second sensor signal 8d, thereby determining the measurement variable M. Also in this case, in particular, the measurement variable M can be determined from the difference or ratio of the sensor signals Ia, Id.

[0048] According to FIG. 5, in step S1, the control device 9 receives the measured variable M transmitted to the control device 9. In step S2, the control device 9 determines the control value A of the first rolling stand 1. According to the example shown in FIG. 5, when determining the control value A, the control device 9 takes into account at least the transmitted measured variable M. Often, when determining the control value A, the control device 9 further takes into account additional variable data, for example, the temperature T of the flat rolled product 2 before rolling in the first rolling stand 1, and / or the rolling force F during rolling of the flat rolled product 2 in the first rolling stand 1, and / or the pass reduction during rolling of the flat rolled product 2 in the first rolling stand 1. The temperature T and the rolling force F can be detected by corresponding sensors, which are well known to those skilled in the art. The pass reduction, that is, the ratio of the thickness d2 of the flat rolled product 2 on the outlet side to the thickness d1 of the flat rolled product 2 on the entrance side (see FIG. 1), can be notified to the control device 9, for example, based on the pass schedule. Furthermore, the control device 9 can also take into account the speed of the flat rolled product 2 in the area of the sensor device 6, especially in the situation of evaluating the measured variable M. If necessary, the positions of the excitation element 7 and / or the sensor elements 8a to 8d can also be taken into account in the same way. In step S3, the control device 9 adjusts the first rolling stand 1 according to the determined control value A.

[0049] The control device 9 repeats steps S1 to S3 in an iterative manner. The time constant for the repetition is generally in the range between 0.1 s and 1.0 s, especially between 0.2 s and 0.5 s.

[0050] The control device 9 is designed to perform the procedure in FIG. 5. According to the example in FIG. 1, furthermore, the control device 9 is generally designed as a software programmable control device. In this case, the control device 9 is programmed using the control program 10. The control program 10 includes program code 11 that can be executed by the control device 9. In operation, the control device 9 executes the program code 11. The execution of the program code 11 by the control device 9 results in the control device 9 having the corresponding design effect.

[0051] Embodiments in which the base signal is the eddy current IW and thus an electrical variable have been described above in conjunction with FIGS. 1 to 5. These embodiments are particularly advantageous when the measured variable M is specific to electrical or electromagnetic material properties. However, these embodiments can also enable inferences about mechanical material properties.

[0052] Another embodiment will be described below in conjunction with FIGS. 6 to 8. Here, FIGS. 6 to 8 show embodiments that are generally similar to FIGS. 2 to 4. The difference is that in FIGS. 6 to 8, the excitation element 7 outputs an acoustic signal, particularly an ultrasonic signal. In the corresponding manner, the sensor elements 8a to 8d are also designed to detect the corresponding acoustic signals. In other respects, the embodiments in FIGS. 2 to 4 can be used in a similar manner.

[0053] Figure 9 shows a modified form of the rolling mill of Figure 1. The difference is that in the embodiment of the rolling mill according to Figure 9, the sensor device 6 is no longer arranged downstream of the first rolling stand 1, but is arranged upstream of the first rolling stand 1. In other respects, the embodiment of Figure 1 and the above-described embodiments, for example, the embodiments in Figures 2 to 8 based on the embodiment of the control device 9 as a software programmable control device, can also continue to be used. In the situation of the embodiment according to Figure 9, in particular, the control device 9 can output a control value A determined by the control device 9 taking into account the measured variable M to the first rolling stand 1 taking into account the path of the flat rolled product 2 from the sensor device 6 to the first rolling stand 1. Details regarding this point will be described below in conjunction with a further embodiment in conjunction with Figure 10.

[0054] Figure 10 is considered starting from Figure 9. Therefore, in exactly the same way as in Figure 9, the sensor device 6 in the embodiment according to Figure 10 is arranged upstream of the first rolling stand 1. The control device 9 includes a model 12, for example, based on the execution of a program code 11. A further sensor device 13 is further arranged downstream of the first rolling stand 1. Using the further sensor device 13, at least one further measured variable M' can be detected. The detected further measured variable M' is specific to the material properties of the flat rolled product 2 after being rolled in the first rolling stand 1. Therefore, the further measured variable M' is specific to the same material properties as the measured variable M, and thus is similar in terms of the approach to the measured variable M. The difference is that the measured variable M is specific to the material properties of the flat rolled product 2 before rolling in the first rolling stand 1, while the measured variable M' is specific to the material properties of the flat rolled product 2 after rolling in the first rolling stand 1.

[0055] Similarly, the further sensor device 13 is connected to the control device 9 of the rolling mill. By the further sensor device 13 being connected to the control device 9, in particular, the detected further measured variable M' can be transmitted to the control device 9.

[0056] Regarding the operation mode of the rolling mill in FIG. 10, it will be described below in conjunction with FIG. 11. As long as it is related to taking into account the path of the flat rolled product 2 from the sensor device 6 to the first rolling stand 1, FIG. 11 also shows the operation of the rolling mill in FIG. 9.

[0057] According to FIG. 11, in step S11, the control device 9 receives the measurement variable M transmitted to the control device 9. Step S11 corresponds 1:1 to step S1 in FIG. 2. In step S12, the control device 9 determines the control value A of the first rolling stand 1. Step S12 basically corresponds to step 2 in FIG. 2. The difference is that in step S12, the control device 9 determines the control value A using the model 12. The determination of the control value A incorporates, among other things, the model parameter k.

[0058] In step S13, taking into account this control value A, that is, the control value A determined in step S12, the control device 9 determines the predicted value E of the material properties of the flat rolled product 2 after rolling in the first rolling stand 1. This determination is also made using the model 12.

[0059] In step S14, the control device 9 waits for the first waiting time t1. The first waiting time t1 corresponds to the time required for a specific section of the flat rolled product 2 to reach the first rolling stand 1 starting from the sensor device 6. Therefore, basically, the control device 9 embodies the path of the flat rolled product 2 from the sensor device 6 to the first rolling stand 1. In the simplest case, the first waiting time t1 (see FIG. 10) corresponds to the distance a1 from the sensor device 6 to the first rolling stand 1 divided by the conveying speed v1 of the flat rolled product 2 upstream of the first rolling stand 1. When additional rolling stands are arranged between the sensor device 6 and the first rolling stand 1, it may be necessary to determine the first waiting time t1 by adding a plurality of times, each time being specific to a particular section and obtained from the conveying speed of the flat rolled product 2 in each section and the length of each section.

[0060] In step S15, therefore, after the expiration of the first waiting time t1, the control device 9 controls the first rolling stand 1 according to the determined control value A. Step S15 substantially corresponds to step S3 in FIG. 2. Therefore, as a result, the control device 9 outputs the control value A to the first rolling stand 1 taking into account the path of the flat rolled product 2 from the sensor device.

[0061] Next, in step S16, the control device 9 waits during the second waiting time t2. The second waiting time t2 corresponds to the time required for a specific section of the flat rolled product 2 to reach the further sensor device 13 starting from the first rolling stand 1. Therefore, basically, the control device 9 embodies the path of the flat rolled product 2 from the first rolling stand 1 to the further sensor device 13. In the simplest case t1 (again, refer to FIG. 10), the second waiting time t2 corresponds to the distance a2 from the first rolling stand 1 to the further sensor device 13 divided by the conveying speed v2 of the flat rolled product 2 downstream of the rolling stand 1. If further rolling stands are arranged between the first rolling stand 1 and the further sensor device 13, it may be necessary to determine the second waiting time t2 by adding multiple times, each time being specific to a particular section and obtained from the conveying speed of the flat rolled product 2 in each section and the length of each section.

[0062] In step S17, therefore, after the expiration of the second waiting time t2, the control device 9 receives from the further sensor device 13 the further measurement variable M' detected by the further sensor device 13 at this time. In step S18, the control device 9 corrects the model parameter k from the comparison between the further measurement variable M' of the material property E and the predicted value E, thereby adapting the model 12. As a result, as part of the adaptation of the model 12, the control device 9 uses the further measurement variable M' for the time point determined by taking into account the path of the flat rolled product 2 from the first rolling stand 1 to the further sensor device 13 by the control device 9.

[0063] The control device 9 repeats steps S11 to S18 in an iterative manner in the same way as steps S1 to S3. The above content regarding steps S1 to S3 can be applied in a similar form.

[0064] In practice, steps S11 to S18, and their order, are further embodied in a slightly different way. For example, steps S11 to S18 can be performed in several processes. Also, the order of steps S11 to S18 can be divided into two parts that are performed in parallel. In this case, the first part includes steps S11 to S15, and the second part includes steps S16 to S18.

[0065] Also, it is similarly possible to omit steps S14 and S16. In this case, direct, asynchronous execution of the remaining steps S11 to S13, S15, S17, and S18 can be performed. In this case, each control value A determined in step S12, and each predicted value E determined in step S13 can be temporarily buffered, for example, in a buffer memory (not shown). Each additional measurement variable M' detected in step S17 can also optionally be temporarily buffered in the buffer memory. In this case, the execution time is assigned to each adjusted value A at the same time as it is stored. In a similar manner, the utilization time is assigned to each predicted value E in this case. Furthermore, the detection time can also optionally be assigned to each additional measurement variable M'. In this case, the stored control value A that has just reached the execution time is output for each execution of step S15. In a similar manner, the stored predicted value E whose utilization time coincides with the current time is used for each execution of step S18. In this situation, it is possible to perform interpolation of the stored control value A and the stored predicted value E to the extent necessary. Also, when the additional measurement variable M' and its detection time are stored, this also applies to the additional measurement variable M' in the same way.

[0066] However, regardless of the specific implementation form, it is important that the adaptation of model 12 in step S18 acts on all executions after steps S12 and S13.

[0067] The property of the control value A is determined such that the control of the first rolling stand 1 by the control value A affects the material properties of the flat rolled product 2. In particular, according to the examples in FIGS. 12 and 13, the control device 9 determines, as the control value A, the ratio of the upper peripheral speed vO to the lower peripheral speed vU. As a result, asymmetric rolling is brought about, where the two work rolls 3, 4 rotate at different peripheral speeds vO, vU. According to the examples in FIGS. 12 and 13, the control value A can be included as a coefficient that, for example, multiplies the lower peripheral speed vU (or its target value vU*) when determining the upper peripheral speed vO (or its target value vO*).

[0068] Generally, the ratio of the upper peripheral speed vO to the lower peripheral speed vU is between 0.5 and 2.0, in particular between 0.9 and 1.1. Generally, it does not matter which of the two work rolls 3, 4 rotates faster than the other work roll 4, 3.

[0069] FIG. 12 further shows an embodiment that is particularly simple to implement from the perspective of control engineering. Specifically, in the context of the embodiment of FIG. 12, the upper work roll 3 is driven by the upper drive unit 14, while the lower work roll 4 is driven by the lower drive unit 15. In the context of the embodiment according to FIG. 12, the lower drive unit 15 is a drive unit different from the upper drive unit 14. In this case, all that is required is to specify the corresponding target values vO*, vU* for the upper drive unit 14 and the lower drive unit 15.

[0070] In contrast, in the embodiment shown in FIG. 13, the upper work roll 3 and the lower work roll 4 are driven by a common drive unit 16. In this case, a transmission 17 is disposed between the common drive unit 16 on one side and the upper work roll 3 and the lower work roll 4 on the other side. The transmission has an input shaft 18 on one side and an upper output shaft 19 and a lower output shaft 20 on the other side. The input shaft 18 is connected to rotate in conjunction with the common drive unit 16. The upper output shaft 19 is connected to rotate in conjunction with the upper work roll 3, while the lower output shaft 20 is connected to rotate in conjunction with the lower work roll 4. The input shaft 18 acts on both the upper output shaft 19 and the lower output shaft 20.

[0071] The transmission 17 is designed such that the ratio of the speed of the upper output shaft 19 to the speed of the lower output shaft 20 can be continuously adjusted by the transmission 17. For example, the transmission 17 can have a splitter block 21 on one side, where the drive train is split between the upper work roll 3 and the lower work roll 4. Then, an intermediate transmission 22 can be disposed between the splitter block 21 and the upper work roll 3, and the use of this intermediate transmission 22 enables continuous variation of the output speed with respect to the input speed of the intermediate transmission 22. This type of intermediate transmission 22 is well known to those skilled in the art. Examples are planetary transmissions and differential transmissions. As an alternative to or in addition to disposing between the splitter block 21 and the upper work roll 3, an intermediate transmission (not shown) can also be disposed between the splitter block 21 and the lower work roll 4.

[0072] FIG. 14 shows, optionally, another type of control value A that can be determined in addition to the control value A acting on the peripheral speeds vO, vU of the work rolls 3, 4. According to FIG. 14, the control value A can be the temperature change of the upper work roll 3, which acts on the upper work roll 3 via the corresponding changing device 23. For example, the upper work roll 3 can be cooled by water spraying. Alternatively or additionally, the control value A can be the temperature change of the lower work roll 4. For example, similar to the upper work roll 3, the cooling of the lower work roll 4 by water spraying can be performed via the corresponding changing device 23'. Alternatively or additionally, the control value A can be the temperature change of the flat rolled product 2 before rolling in the first rolling stand 1. The heating of the flat rolled product 2, in particular induction heating, can be performed, for example, via the corresponding changing device 23".

[0073] The basic principle of the present invention and various possible embodiments have been described above in conjunction with FIGS. 1 to 14. In the situation of FIGS. 1 to 14, a reversing rolling mill having only one rolling stand 1, that is, the first rolling stand 1, has been considered. However, regardless of whether it is implemented as a reversing rolling mill, overall similar embodiments are also possible if the rolling mill additionally has a further rolling stand hereinafter referred to as the second rolling stand 24.

[0074] Thus, for example, according to the examples in FIGS. 15 to 20, the rolling mill can have a plurality of rolling stands 1, 24, and the rolling products 2 flow continuously one after another through the rolling stands 1, 24. Therefore, in this case, the rolling mill is designed as a multi-stand rolling train. However, the numbers shown for each of the five rolling stands 1, 24 arranged in series are merely examples. Also in FIGS. 15 to 20, only the work rolls of the second rolling stand 24 are shown. However, generally, similar to the first rolling stand 1, the second rolling stand 24 has further rolls. Furthermore, only the rolling stands 1, 24, the rolling products 2, and the sensor devices 6, and optionally further sensor devices 13 are shown in FIGS. 15 to 20. However, there are further components of the rolling mill, in particular, the control device 9. Moreover, the control device 9 acts on all of the rolling stands 1, 24 of the rolling mill, even if only the control of the first rolling stand 1 by the control value A is illustrated in FIGS. 15 to 20.

[0075] The embodiments in FIGS. 15 to 20 are mostly the same. However, they differ in the arrangement of the sensor device 6, the arrangement of the second rolling stand 24 relative to the sensor device 6 and the first rolling stand 1, and whether there is a further sensor device 13 or not.

[0076] Specifically, the sensor device 6 in the embodiments shown in FIGS. 15 and 16 is arranged downstream of the last rolling stands 1, 24 of the rolling train. In the embodiment shown in FIG. 15, the control value A, that is, the control value A determined taking into account the measured variable M, acts on the last rolling stand 1 of the rolling train. In this case, the second rolling stand 24 is not arranged between the sensor device 6 and the first rolling stand 1. In contrast, in the embodiment shown in FIG. 16, the control value A, that is, the control value A determined taking into account the measured variable M, acts on another rolling stand 1 of the rolling train, for example, the second last rolling stand of the rolling train arranged immediately upstream of the last rolling stand 24 of the rolling train. In this case, at least one of the second rolling stands 24, specifically, at least the last rolling stand 24 of the rolling train is arranged between the sensor device 6 and the first rolling stand 1.

[0077] In the embodiments shown in FIGS. 17 to 20, the sensor device 6 is arranged upstream of the first rolling stands 1, 24 of the rolling train. In the embodiments shown in FIGS. 17 and 19, the control value A, that is, the control value A determined taking into account the measured variable M, acts on the first rolling stand 1 of the rolling train. Therefore, in this case, the second rolling stand 24 is not arranged between the sensor device 6 and the first rolling stand 1. In contrast, in the embodiments shown in FIGS. 18 and 20, the control value A, that is, the control value A determined taking into account the measured variable M, acts on another rolling stand 1 of the rolling train, for example, the rolling stand 1 arranged immediately downstream of the first rolling stand 24 of the rolling train. In this case, at least one of the second rolling stands 24, specifically, at least the first rolling stand 24 of the rolling train is arranged between the sensor device 6 and the first rolling stand 1.

[0078] In the embodiments in FIGS. 19 and 20, a further sensor device 13 is additionally arranged downstream of the last rolling stands 1, 24 of the rolling train, and thus the corresponding adaptation of the model 12 can be carried out. In contrast, in the embodiments in FIGS. 17 and 18, there is no further sensor device 13.

[0079] The embodiments in FIGS. 15 to 20 are merely possible embodiments of a multi-stand rolling train. For example, a plurality of second rolling stands 24 can be arranged between the first rolling stand 1 and the sensor device 6. In an extreme case, the sensor device 6 can be arranged downstream of the last rolling stand 24 of the rolling train and act on the first rolling stand 1 of the rolling train, or vice versa, it can be arranged upstream of the first rolling stand 24 of the rolling train and act on the last rolling stand 1 of the rolling train. Also, a plurality of sensor devices 6 and / or a plurality of further sensor devices 13, for example, each sensor device 6 and / or further sensor device 13, can be provided upstream and / or downstream of each individual rolling stand 1, 24 of the rolling train. Also, although not in all cases of the rolling stands 1, 24, it is also possible to implement such a configuration between some of the rolling stands 1, 24. Also, it is possible for the control device 9 to determine a plurality of control values A acting on another first rolling stand 1 using the measured variable M of a single sensor device. The embodiments employed in specific cases are at the discretion of those skilled in the art.

[0080] Regardless of which embodiment is employed in which specific case, the operating mode of each rolling mill in FIGS. 15 to 20, as far as applicable to the present invention, is the same as that described above in conjunction with FIGS. 1 to 14 for a reversing rolling mill having a single rolling stand 1, i.e., the first rolling stand 1.

[0081] The present invention has many advantages. In particular, the procedure according to the present invention can be easily integrated into the continuous operation of a rolling mill. In the case of electrical steel sheets, as well as in the case of other steel grades, annealing after cold rolling or between two cold rolling steps is often no longer necessary or only necessary to a limited extent. In the case of AHSS, as well as in the case of martensite grades and bainite grades, the banding of material properties due to cooling in the cooling zone of the hot rolling train can be reduced or eliminated. As long as the action on the flat rolled product 2 by the control value A can be carried out by local decomposition in the transverse direction of the flat rolled product 2 (this is especially the case when accompanied by thermal changes), and in certain situations, it may also be possible to arrange a plurality of sensor devices 6 side by side.

[0082] The present invention has been described in more specific detail using preferred exemplary embodiments, but the present invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without exceeding the protection scope of the present invention.

Explanation of Reference Signs

[0083] 1, 24 Rolling stands 2 Flat rolled product 3 Upper work roll 4 Lower work roll 5 Coiler 6, 13 Sensor devices 7 Excitation element 8a - 8d Sensor elements 9 Control device 10 Control program 11 Program code 12 Model 14 - 16 Driving parts 17 Transmission 18 Input shaft 19, 20 Output shafts 21 Splitter block 22 Intermediate transmission 23, 23’, 23” Changing devices A control value a1, a2 distances d1, d2 thicknesses E predicted value F rolling force IA, IW currents Ia~Id sensor signals k model parameter M, M’ measured variables S1~S18 steps t1, t2 waiting times T temperature v, v1, v2 conveyance speeds vO, vU peripheral speeds vO*, vU* target values x conveyance direction

Claims

1. A rolling mill having a first rolling stand (1) for rolling a flat rolled product (2) made of metal, - A sensor device (6) capable of detecting at least one measurement variable (M) specific to the material properties of the flat rolled product (2) is arranged upstream and / or downstream of the first rolling stand (1), - The sensor device (6) is connected to a control device (9) of the rolling mill to transmit the detected measurement variable (M), - The control device (9) is designed to take into account the transmitted measurement variable (M) in a situation where the control device (9) determines a control value (A) for the first rolling stand (1), - By controlling the first rolling stand (1) with the control value (A), the material properties of the flat rolled product (2) are affected, - The first rolling stand (1) has an upper work roll (3) and a lower work roll (4), In a rolling mill, The control device (9) is designed such that the control value (A) determined taking into account the measurement variable (M) is a ratio of the upper peripheral speed (vO) at which the upper work roll (3) rotates to the lower peripheral speed (vU) at which the lower work roll (4) rotates A rolling mill characterized by this.

2. The rolling mill has at least one second rolling stand (24), and the second rolling stand (24) is not arranged between the sensor device (6) and the first rolling stand (1), or the rolling mill has at least one second rolling stand (24), and at least one of the second rolling stands (24) is arranged between the sensor device (6) and the first rolling stand (1) A rolling mill according to claim 1, characterized by this.

3. The control device (9) is designed to determine the ratio of the upper peripheral speed (vO) to the lower peripheral speed (vU) to be between 0.5 and 2.0 A rolling mill according to claim 1 or 2, characterized by this.

4. The upper work roll (3) is driven by an upper drive unit (14), and the lower work roll (4) is driven by a lower drive unit (15) different from the upper drive unit (14) A rolling mill according to any one of claims 1 to 3, characterized by this.

5. The upper work roll (3) and the lower work roll (4) are driven by a common drive unit (16), and a transmission (17) that can continuously adjust the ratio of the speed of the upper output shaft (19) connected so as to rotate in conjunction with the upper work roll (3) to the speed of the lower output shaft (20) connected so as to rotate in conjunction with the lower work roll (4) is disposed between the common drive unit (16) on one side and the upper work roll (3) and the lower work roll (4) on the other side. The rolling mill according to any one of claims 1 to 3, characterized in that.

6. The first rolling stand (1) has an upper work roll (3) and a lower work roll (4), and the control device (9) is such that the control value (A) determined in consideration of the measurement variable (M) is the ratio of the upper peripheral speed (vO) at which the upper work roll (3) rotates to the lower peripheral speed (vU) at which the lower work roll (4) rotates, the temperature change of the upper work roll (3) and / or the lower work roll (4) of the first rolling stand (1), and / or the temperature change of the flat rolled product (2) before rolling in the first rolling stand (1), designed to be as follows The rolling mill according to any one of claims 1 to 5, characterized in that.

7. The sensor device (6) is disposed upstream of the first rolling stand (1), and the control device (9) takes into account the travel path of the flat rolled product (2) from the sensor device (6) to the first rolling stand (1) for the control value (A) determined by the control device (9) in consideration of the measurement variable (M), and is designed to output it to the first rolling stand (1). The rolling mill according to any one of claims 1 to 6, characterized in that.

8. - The control device (9) includes a model (12), and using the model (12), the control device (9) determines the control value (A) of the first rolling stand (1) in consideration of the measurement variable (M), and further determines a predicted value (E) of the material properties of the flat rolled product (2) after rolling in the first rolling stand (1) in consideration of the control value (A) determined in consideration of the measurement variable (M). - A further sensor device (13) capable of detecting at least one further measurement variable (M') specific to the material properties of the flat rolled product (2) after rolling in the first rolling stand (1) is arranged downstream of the first rolling stand (1), - The further sensor device (13) is connected to the control device (9) to transmit the detected further measurement variable (M'), - The control device (9) is designed to use the further measurement variable (M') at a time when the control device (9) determines taking into account the path of the flat rolled product (2) from the first rolling stand (1) to the further sensor device (13), - The control device (9) is designed to adapt the model (12) based on a comparison of the further measurement variable (M') of the material properties with the predicted value (E), The rolling mill according to claim 7, characterized in that.

9. When determining the control value (A), the control device (9) takes into account, in addition to the transmitted measurement variable (M), the temperature (T) of the flat rolled product (2) before rolling in the first rolling stand (1) for the flat rolled product (2), and / or the rolling force (F) during rolling of the flat rolled product (2) in the first rolling stand (1), and / or the pass reduction during rolling of the flat rolled product (2) in the first rolling stand (1). The rolling mill according to any one of claims 1 to 8, characterized in that it is designed to do so. The rolling mill according to any one of claims 1 to 8, characterized in that.

10. - The sensor device (6) comprises an excitation element (7) and a first sensor element (8a), - A base signal is excited in the flat rolled product (2) by the excitation element (7), - A first sensor signal (Ia) based on the excited base signal is detected by the first sensor element (8a), - The sensor device (6) determines the transmitted measurement variable (M) taking into account the first sensor signal (Ia), or the transmitted measurement variable (M) includes the first sensor signal (Ia). The rolling mill according to any one of claims 1 to 9, characterized in that.

11. - The sensor device (6) further comprises several second sensor elements (8b - 8d), - When viewed in the conveying direction (x) from the first sensor element (8a), each of the second sensor elements (8b to 8d) is arranged offset upstream or downstream and / or in the lateral direction of the first sensor element (8a), - Each second sensor signal (Ib to Id) of the same type as the first sensor signal (Ia) based on the excited base signal is detected by each of the second sensor elements (8b to 8d), - The sensor device (6) determines the transmitted measurement variable (M) taking into account each of the second sensor signals (Ib to Id), or the transmitted measurement variable (M) includes each of the second sensor signals (Ib to Id) The rolling mill according to claim 10, characterized in that.

12. The base signal is an eddy current (IW) or an acoustic signal The rolling mill according to claim 10 or 11, characterized in that.

13. The connecting line from the excitation element (7) to the first sensor element (8a) extends parallel to the conveying direction (x) The rolling mill according to any one of claims 10 to 12, characterized in that.

14. The material property is an electromagnetic property or a mechanical property of the flat rolled product (2) The rolling mill according to any one of claims 1 to 13, characterized in that.

15. It is a cold rolling mill The rolling mill according to any one of claims 1 to 14, characterized in that.

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