The present invention starts from a storage device for two rolls of the same type in a roll stand, wherein the storage device is a component part of the roll stand or can be positioned relative to the roll stand in such a way that the rolls can be transferred from the roll stand into the storage device or vice versa.
During the rolling of flat rolling stock made of metal, the rolling gap is usually calculated in the context of “level-2” automation. To calculate the rolling gap, complex models are used, which take into account the roll setting, the roll bending, the roll flattening, the roll camber, the roll wear, the roll temperature, the temperature of the rolling stock and other factors, for example. Some of the variables mentioned are specified as a respective characteristic over the roll barrel width. Thus, for example, the thickness of a roll is greater locally (the term “locally” refers to the location as viewed in the direction of the roll axis), the higher the temperature of the roll at the respective location. Conversely, the roll is locally thinner, the greater the wear or abrasion of the roll at the respective location.
The absolute accuracy with which the rolling gap must be calculated is all the greater, the smaller the rolling gap. In the case of a rolling gap of—for example—3 cm, an accuracy of 20 μm or 50 μm may be entirely acceptable. In the case of a rolling gap of—for example—1.2 mm, in contrast, an accuracy of this kind is generally no longer acceptable.
As already mentioned, the rolling gap is affected by, among other things, the local temperature of the rolls. Moreover, the rolling gap is also affected by the abrasion to which the rolls are subject in operation. In addition, the material temperature of the flat rolling stock also depends, within certain limits, on the temperature of the working rolls. The temperature of the rolling stock, in turn, is an important criterion, for example, for the correct determination of the rolling force. This applies both to hot rolling and to cold rolling.
Neither the temperature of the working rolls nor the abrasion or wear can be measured directly during rolling. For this reason, use is made of roll models, by means of which the temperature of the working rolls and also the wear of the working rolls can be determined with the assistance of the models, using operating parameters of the roll stand that can be measured and are known in other ways. Similar ways of proceeding may also be adopted for other roll pairs of a roll stand, e.g. for the support rolls of a four-high stand or for the intermediate rolls of a six-high stand, which are arranged between the support rolls and the working rolls.
The models by means of which the rolls and the rolling gap are modeled are subject to error. The aim of those skilled in the art is therefore to optimize the models. This applies also to the roll model.
WO 2012/025 266 A1 discloses a method by means of which, in the case of a roll of a roll stand, both the temperature of the roll and the wear of the roll can be determined. Determination is performed with location resolution as viewed in the direction of the roll axis.
WO 2017/144 227 A1 and WO 2011/124 585 A1 disclose procedures by means of which working rolls of a roll stand can be changed while flat rolling stock is passing through the roll stand.
It is the object of the present invention to provide possibilities by means of which a roll model, by means of which the temperatures of rolls and the wear thereof and hence the diameters thereof can be determined with location resolution as viewed in the direction of the roll axes, can be optimized in a simple and reliable manner.
The object is achieved by means of a storage device having the features discussed herein. Advantageous refinements of the storage device form the subject matter of further exemplary embodiments discussed herein.
The present invention furthermore starts from an operating method for a roll stand, wherein flat rolling stock passing through the roll stand is rolled between two rolls of the same type in the roll stand. An automation unit that controls the roll stand repeatedly determines the temperatures and/or the diameters of the rolls, at least at predefined determination positions, as viewed in the direction of the roll axes. By means of a roll model using operating data of the roll stand for the rolls of the same type and, based on the temperatures and/or diameters determined, the automation unit determines an activation of the roll stand. The result is that a rolling gap of the roll stand is set during the rolling of the flat rolling stock, as far as possible in accordance with setpoint inputs. The rolls of the same type are removed from the roll stand from time to time and are transferred into a roll changing carriage.
According to the invention, a storage device of the type stated at the outset is configured in such a way that the storage device has at least one measuring system, by means of which the temperatures and/or the diameters of the rolls can be detected individually and independently of one another, at least at predefined detection positions, as viewed in the direction of the roll axes.
It is thereby possible to detect the actual temperatures and/or the actual diameters of the rolls by measurement, thus enabling them to be compared with the corresponding values determined with model assistance and enabling the roll model to be adapted based on the comparison.
It is possible—if only by way of exception—for the storage device to be a component part of the roll stand. However, this configuration is generally appropriate only in a special embodiment. In general, however, the storage device is designed as a roll changing carriage. In this case, it is possible, in particular to ensure in a simple manner that the measuring system is not exposed to the rough operation of the roll stand, as occurs when rolling the flat rolling stock.
It is possible that, for each roll, the measuring system has a plurality of measuring devices that are fixed in location relative to a main body of the storage device, thus enabling the temperature and/or the diameter of the respective roll to be detected at each of the predefined detection positions, as viewed in the direction of the roll axes, by means of the measuring devices. With such an embodiment, a measuring device, by means of which the temperature and/or the diameter of the respective roll can be detected at the respective location, can be provided every 10 cm or every 20 cm—for example—as viewed in the direction of the roll axes.
As an alternative, it is possible that, for each roll, the measuring system has a plurality of measuring devices that are movable in the direction of the roll axes relative to a main body of the storage device, thus enabling the temperature and/or the diameter of the respective roll to be detected in a respective subsection including in each case at least one of the predefined detection positions, as viewed in the direction of the roll axes, by means of the measuring devices. For example, the measuring devices can be movable to the left and right by in each case 5 cm, 8 cm, 12 cm or 15 cm, as viewed in the direction of the roll axes, from a central position of the respective measuring device. In this case, the temperature and/or the diameter of the respective roll can be detected in a respective subregion of 10 cm, 16 cm, 24 cm or 30 cm by means of in each case one of the measuring devices. As before, the numerical values mentioned are purely illustrative. Depending on the size of the subregions and the offset between them—e.g. 10 cm or 20 cm—the subregions may overlap or be disjunctive with respect to one another.
As another alternative, it is possible that, for each roll, the measuring system has a single measuring device, by means of which the temperatures and/or the diameters of the respective roll can be detected at least at all of the predefined detection positions, as viewed in the direction of the roll axes. This embodiment has the advantage that only a minimal number of measuring devices is required.
In the latter case, two mutually alternative embodiments are once again possible.
On the one hand, it is possible that the measuring device is arranged on a main body of the storage device in such a way as to be movable as viewed in the direction of the roll axes, thus enabling the measuring device to be moved over the entire effective barrel length of the rolls. In this case, the rolls are first of all arranged in the main body of the storage device. The measuring device is then moved along the rolls. During this movement—which may be interrupted repeatedly for an individual measuring process—the temperatures and/or the diameters of the rolls are detected.
On the other hand, it is possible that the measuring device is arranged in a fixed location on a main body of the storage device in such a way that the respective roll is moved past the measuring device during transfer from the roll stand into a roll changing carriage or vice versa. This embodiment is particularly simple since there is no need for any further movable parts beyond those parts which have to be present in any case to transfer the rolls from the roll stand into the roll changing carriage or vice versa. More specifically, this embodiment can furthermore be implemented not only on a roll changing carriage but also on a roll stand itself. In particular, it is possible in this case for the measuring device to be arranged in a protected region of the operator-side stand housing.
It is possible for the detected measured values to be fed manually to an automation unit that controls the roll stand. Preferably, however, there is a data link between the measuring system and the automation unit, and the measuring system transmits the detected temperatures and/or diameters automatically to the automation unit, thus enabling the detected temperatures and/or diameters to be associated with the predefined detection positions by the automation unit. For this purpose, it may also be necessary, in addition to the temperatures and/or diameters, for the detection positions to be transmitted to the automation unit.
The object is furthermore achieved by means of an operating method for a roll stand having the features discussed herein. According to the invention, an operating method of the type stated at the outset is embodied in such a way that the temperatures and/or the diameters of the two rolls are detected in an automated manner, at least at predefined detection positions, as viewed in the direction of the roll axes, during the removal of the rolls from the roll stand and the transfer of the rolls into the roll changing carriage or immediately following this in time. By means of a measuring system arranged on the roll stand or on the roll changing carriage, the detected temperatures and/or diameters are transmitted automatically to the automation unit, thus enabling the detected temperatures and/or diameters to be associated with the predefined detection positions by the automation unit. The automation unit compares the temperatures of the rolls determined by means of the roll model and/or the diameters of the rolls determined by means of the roll model with the temperatures of the rolls determined by means of the measuring system and/or the diameters of the rolls determined by means of the measuring system, and adapts the roll model using the comparison.
The above-described properties, features and advantages of this invention and the manner in which these are achieved will become more clearly and distinctly comprehensible in conjunction with the following description of the illustrative embodiments, which are explained in greater detail in combination with the drawings. Here, in schematic illustration:
According to
The roll train is controlled by an automation unit 4. In particular, the automation unit 4 thus also controls the roll stands 2. The control of one of the roll stands 2 by the automation unit 4 is explained in greater detail below—as a representative example of all roll stands 2—in combination with
According to
The automation unit 4 then compares the expected actual properties of the flat rolling stock 1 as it passes out of the roll stand 2, which have been determined by means of the roll model 5, with the desired setpoint properties of the flat rolling stock 1 as it passes out of the roll stand 2. As far as necessary, the automation unit 4 thereupon varies the control data SD in order to approximate the expected actual properties of the flat rolling stock 1 as it passes out of the roll stand 2 as far as possible to the desired setpoint properties of the flat rolling stock 1 as it passes out of the roll stand 2. As far as necessary, this involves an iterative procedure. The variation of the control data SD is indicated in
As already mentioned, the procedure explained is already widely known and familiar as such to those skilled in the art. It is carried out repeatedly during the rolling of the flat rolling stock 1, e.g. for a new section of the flat rolling stock 1 or for subsequent flat rolling stock 1. As a result, the automation unit 4 thus repeatedly determines the temperatures T and/or the diameters D of the rolls 3 (among other factors and with location resolution as viewed in the direction of the roll axes) and, based thereon, determines the respective activation SD of the roll stand 2, i.e. the control data SD. The determination of the diameters D incorporates both the temperature-induced expansion of the rolls 3 and also the wear-related change in the diameter D. Corresponding models are known to those skilled in the art by the term TWC (thermal wear crown). As part of modeling, the temperature of the flat rolling stock 1 is often also determined. This too is widely known and familiar to those skilled in the art.
After rolling a certain number of pieces of flat rolling stock 1—e.g. after rolling 20 or 25 pieces of flat rolling stock 1—the rolls 3 must be changed. For this purpose, a roll changing carriage 6 is positioned next to the roll stand 2, the rolls 3 of which are to be changed, in accordance with the illustration in
In general, a pause in rolling, during which no flat rolling stock 1 is rolled in the roll train, is introduced for this process.
The removal of the rolls 3 and transfer of the rolls 3 into the roll changing carriage 6 can be performed in a conventional, widely known manner. It is important, however, that the temperatures T and/or the diameters D of the two rolls 3 are detected during the removal of the rolls 3 from the roll stand 2 and transfer of the rolls 3 into the roll changing carriage 6 or immediately following said procedures in time. Thus, detection is carried out before the roll changing carriage 6 is moved away from the roll stand 2.
Detection is carried out in an automated manner by means of a measuring system 7, which is arranged on the roll stand 2 or on the roll changing carriage 6. Furthermore, detection is carried out with location resolution as viewed in the direction of the roll axes, namely at least at predefined detection positions p′. Directly adjacent detection positions p′ can have a spacing of 8 cm, 10 cm, 12 cm, 15 cm or 20 cm from one another, for example.
Furthermore, the temperatures T and/or the diameters D can be detected individually and independently of one another by means of the measuring system 7. Thus, from the temperature T detected for a certain detection position p′, it is not possible or not readily possible to derive conclusions about the temperature T for another detection position p′. A similar situation applies in respect of the detected diameter D. Possible implementations of this procedure will be explained below.
The detected temperatures T and/or diameters D are transmitted automatically from the measuring system 7 to the automation unit 4. For this purpose, the measuring system 7 has a data link with the automation unit 4. Wired transmission or wireless transmission are possible alternatives here. To implement wireless transmission, the measuring system 7 and the automation unit 4 can implement a radio link via antennae 8 in accordance with the illustration in
The detected temperatures T and/or diameters D are transmitted in a manner which puts the automation unit 4 in a position to associate the detected temperatures T and/or diameters D with the predefined detection positions p′. For example, the detection positions p′ can be transmitted at the same time. It is also possible for the automation unit 4 to know in advance at which detection positions p′ the temperatures T and/or diameters D will be detected and in what sequence the detected temperatures T and/or diameters D will be transmitted from the measuring system 7 to the automation unit 4.
The automation unit 4 receives the transmitted temperatures T and/or diameters D in a step S1 according to
In a step S3, the automation unit 4 compares the temperatures T and/or the corresponding diameters D of the rolls 3 determined by means of the roll model 5 with the temperatures T and/or diameters D of the rolls 3 detected by means of the measuring system 7. In particular, it is possible in step S3 for the automation unit 4 to determine a first modification value δk1 for a first model parameter k1 of the roll model 5 on the basis of the comparison of the temperatures T and to determine a second modification value δk2 for a second model parameter k2 of the roll model 5 on the basis of the comparison of the diameters D. Using the modification values ski, δk2 determined, the automation unit 4 can then correct the model parameters k1, k2 in a step S4 and can thereby adapt the roll model 5. Of course, the model parameters k1, k2 enter into the determination of the temperatures T and/or diameters D of the rolls 3, which is carried out by means of the roll model 5.
Possible embodiments on which the detection of the temperatures T and/or diameters D can be performed are now explained below in combination with
In all the embodiments, there is a storage device for the two rolls 3. In most of the embodiments, the storage device is designed as a roll changing carriage 6 in accordance with the illustrations in
It is thus possible, for example, in accordance with the illustration in
In the case of the embodiments shown in
In order to enable such detection, the embodiment of
Consequently, the only important factor for data acquisition at all of the predefined detection positions p′ by means of a single measuring device 9 for each roll 3 is the relative movement of the measuring device 9 relative to the roll 3. It is therefore not important during data acquisition whether the roll 3 is at rest in the main body 10 of the roll changing carriage 6 and the measuring device 9 is moved or whether, conversely, the measuring device 9 is at rest and the roll 3 is moved. In accordance with the illustration in
Precisely this embodiment—i.e. the embodiment in which the measuring device 9 is arranged in a fixed location and the respective roll 3 is moved past the measuring device 9 during transfer from the roll stand 2 into the roll changing carriage 6 or vice versa—can also be implemented in such a way that the measuring device 9 is not arranged in a fixed location on the roll changing carriage 6 but on the roll stand 2 itself, in particular on the operator-side stand housing 2′, in accordance with the illustration in
The present invention has many advantages. In particular, continuous correction of the model parameters k1, k2 of the roll model 5 is possible in a simple and reliable manner Owing to the improved modeling, quality in the rolling of the rolling stock 1 can also be improved. In particular, the quality of the thickness, flatness and contour can be enhanced. Modeling of the temperature of the rolling stock 1 can also be improved. Furthermore, improved prediction in the rolling of new materials is possible.
Although the invention has been illustrated and described more specifically in detail by means of the preferred illustrative embodiment, the invention is not restricted by the examples disclosed, and other variants can be derived therefrom by a person skilled in the art without exceeding the scope of protection of the invention.
Number | Date | Country | Kind |
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20151947.7 | Jan 2020 | EP | regional |
The present application is a divisional patent application of U.S. patent application Ser. No. 17/108,482, entitled “ADAPTATION OF A ROLL MODEL”, filed Dec. 1, 2020, which claims the benefit of European Patent Application No. EP20151947.7, entitled “IMPROVED ADAPTATION OF A ROLL MODEL”, filed Jan. 15, 2020, which are both incorporated by reference in their entirety.
Number | Date | Country | |
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Parent | 17108482 | Dec 2020 | US |
Child | 18144962 | US |