EP4013556A1

EP4013556A1 - Method for the online determination of at least one rolling parameter, and rolling mill with a device for the online determination of at least one rolling parameter

Info

Publication number: EP4013556A1
Application number: EP20745088.3A
Authority: EP
Inventors: Thomas Daube; Thomas Nerzak; Jörg Himmel; Annette Jobst; Mario RADSCHUN
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2019-08-16
Filing date: 2020-06-15
Publication date: 2022-06-22
Anticipated expiration: 2040-06-15
Also published as: US20220258221A1; US11992866B2; DE112020003887A5; JP2022544455A; EP4013556B1; WO2021032233A1; ES2966067T3; KR20220044514A

Abstract

The invention relates to a method for the online determination of at least one rolling parameter when rolling a rolling material (20) rolled along a rolling line (13) in a rolling mill (10) comprising at least two rolls (12) on a roll stand (II), in which method the rolling material (20) is guided past or through at least one measuring device (31) during the rolling, which interacts with a rolling material variable of the rolling material (20), said rolling material variable being changeable along the length (21) of the rolling material (20), and outputs a measurement signal (40), wherein: (i) the measurement signal (40) is transferred into the frequency space, and the rolling parameter is determined from the measurement signal (40) transferred into the frequency space, and/or (ii) a frequency (41) inherent in the change of the rolling material variable is determined from the measurement signal (40), and the rolling parameter is determined on the basis of the determined frequency (41).

Description

Method for online determination of at least one rolling parameter and a rolling mill with a device for online determination of at least one rolling parameter

The invention relates to a method for online determination of at least one rolling parameter when rolling a rolling mill comprising at least two rolls on a roll stand along a rolling line, in which the rolling stock moves past or through at least one measuring device during rolling is performed, which interacts with a variable rolling stock size along the length of the rolling stock and outputs a measurement signal. The invention also relates to a rolling mill comprising at least two rolls arranged on a roll stand for rolling rolling stock along a rolling line and having a device for online determination of at least one rolling parameter, the determining device comprising at least one measuring device that is arranged on the rolling line and the one with can interact with a rolling stock size of the rolling stock that is variable along the longitudinal extent of the rolling stock and can output a measurement signal.

When rolling in a rolling mill, a rolling stock, which can be, for example, a sheet metal, a slab, a block, a hollow block, a hollow, a hollow hollow or a rod, a wire or a pipe, is guided past at least one rolling stand or passed through it, which carries at least two rollers and has a correspondingly deforming effect on the rolling stock that is passed or passed through. It is well known that such rolling bars, depending on the specific rolling mill, can also carry more than two rollers, which do not necessarily all have or have a deforming effect on the rolling stock. Rather, if necessary, the rollers can only interact with the rolling stock in a driving or leading manner, as long as at least two rollers act accordingly in a deforming manner on the rolling stock. Accordingly, in particular, several roll stands can also be provided, each of the roll stands being adapted to specific functionalities and being able to carry corresponding rolls.

As a rule, the rolling takes place under relatively adverse environmental conditions, since the rolling stock can generally only be sufficiently deformed at relatively high temperatures. High proportions of scale, dust, steam and the like can also be found in the vicinity of such a rolling mill. This makes it a relatively great challenge to monitor a rolling process online, especially since the rolling stock is usually is also guided at relatively high speeds along the rolling line past or through the rolling stands, so that corresponding measurement results have to be made available in a relatively short time if they are to be considered as determined online.

[04] For example, from DE 102015 119548 A1, a measuring device is known which, thanks to its structural structure and cooling, even under relatively adverse ambient conditions such as high temperatures, scale, steam and dust, a measurement of a rolling stock size of the rolling stock that extends along the longitudinal extension of the rolled stock changed, made possible. It goes without saying that there are also other approaches in the prior art for measuring variable rolling stock sizes along the longitudinal extension of the rolling stock.

[05] In particular, J. Weidemüller, (“Optimization of Encircling Eddy Current Sensors for Online Monitoring of Hot Rolled Round Steel Bars”, 2014, ISBN 9783844027945) disclose the SMS group corporate communication (newsletter Das Magazin der SMS group, issue 02/2016 ", 2016, Düsseldorf) and M. Radschun, A. Jobst, O. Kanoun, J. Himmel (" Non-contacting Velocity Measurements of Hot Rod and Wire Using Eddy-Current Sensors ", 2019 IEEE Workshop 2019, Mülheim ad Ruhr) Each impedance sensor, by means of which variable cross-sectional area changes of the rolling stock can be measured along the longitudinal extent of the rolling stock. R. Hinkforth (Massivumformung - Bulk forming process, Aachen, Wissenschaftsverlag Mainz, 2003) also discloses an offline measurement of the advance of the rolling stock when it leaves a rolling pass.

The object of the present invention is to provide a method for online determination of at least one rolling parameter and a rolling mill with a device for online determination of at least one rolling parameter, which can provide a rolling parameter online in a relatively simple and reliable manner.

The object of the invention is achieved by a method for online determination of at least one rolling parameter and by a rolling mill with a device for online determination of at least one rolling parameter with the features of the independent claims. Further advantageous refinements, possibly also independent thereof, can be found in the subclaims and the following description.

[08] A method for online determination of at least one rolling parameter when rolling a rolling mill comprising at least two rolls on a rolling stand along a rolling line can be used, in which the rolling stock is at least a measuring device during rolling or possibly also guided through it, which interacts with a rolling stock variable along the length of the rolling stock and outputs a measurement signal, characterized in that the measurement signal is transferred to the frequency domain and the rolling parameters from the in the measurement signal transferred to the frequency domain is determined in order to be able to provide the rolling parameters online in a relatively simple and operationally reliable manner.

[09] If the rolling stock passes the measuring device with its rolling stock size that is variable along its length, a measurement signal follows from this if the rolling stock size changes accordingly. The transfer of the measurement signal into the frequency domain then enables a simple and relatively reliable frequency analysis of the measurement signal. On the basis of this frequency analysis or on the basis of the measurement signal transferred from the frequency domain, rolling parameters can then be determined if necessary by assuming that, although the rolling stock should ideally be uniform along its length, deviations from this uniformity are determined and used to determine the Rolling parameters can be used. This applies in particular when it is assumed that the rollers act on the rolling stock with a certain regularity, which is due to their rotation or rotation. Corresponding out-of-roundness or other markings or the like on the rolls then result in correspondingly fluctuating measurement signals, with individual frequencies being able to be assigned to specific rolls or to a roll stand supporting these rolls in the frequency space. Such an assignment can take place relatively easily and reliably in the frequency domain, so that after this assignment the rolling parameters can also be made available online in a relatively simple and reliable manner.

[10] In particular, it has been found that significant frequency peaks of the measurement signal transferred into the frequency space are often caused by the action of one or more of the rolls of the roll stand arranged directly in front of the measuring device that generates the measurement signal. This can be due, for example, to inherent elasticity, minor out-of-roundness or minimal defects in the rolls, but also to the natural frequencies of the roll stand and other influences.

[11] It goes without saying that any suitable space equipped with frequencies as units can be used as the frequency space, in which the measurement signal recorded over time, i.e. the measurement signal initially recorded in the period, can be transferred with sufficient operational reliability but also sufficiently quickly . In particular A transfer by means of a Fourier transformation offers itself here, whereby it can be quite useful to choose the frequency space finite, since very high frequencies and also very low frequencies no longer allow any relevant statements to be expected. Fast Fourier transformations or similar transformations, which enable a measurement signal to be transferred from the time period to the frequency domain, can also easily be used in this regard.

[12] In order to be able to provide a rolling parameter online in a relatively simple and reliable manner, a method for online determination of at least one rolling parameter when rolling a rolling mill comprising at least two rolls on a roll stand can be used, in which the rolling stock is rolled along a rolling line at least one measuring device is passed or passed through it during rolling, which interacts with a variable rolling stock size along the length of the rolling stock and outputs a measurement signal, cumulatively or alternatively characterized in that a frequency inherent in the change in size is derived from the measurement signal determined and the rolling parameter is determined based on the determined frequency.

[13] In order to determine a frequency inherent in the change in the variable from the measurement signal, as already explained above, it is possible, for example, to transfer it to the frequency domain. This is already relatively easy and reliable to do. On the other hand, it is also conceivable to search for specific frequencies using suitable filters, which can possibly lead to even faster frequency determinations. Accordingly, it is understood that any suitable, known method can be used to determine the frequency, with which frequencies that are significant in this context can be determined from a measurement signal.

[14] Cumulatively or alternatively, a rolling parameter can be provided online in a relatively simple and operationally reliable manner if there is a rolling mill which comprises at least two rolls arranged on a roll stand for rolling rolling stock along a rolling line and a device for online determination of at least one rolling parameter , in which the determining device comprises at least one measuring device which is arranged on the rolling line and which can interact with a rolling stock size of the rolling stock that is variable along the longitudinal extent of the rolling stock and can output a measurement signal, cumulatively or alternatively characterized in that the determining device includes means for frequency analysis . As already explained above, a frequency that is inherent in the change in the size of the rolling stock can be determined relatively easily and reliably using a frequency analysis and, accordingly, also by frequency analysis means from the measurement signal. This then accordingly enables the rolling parameter to be determined relatively easily and reliably on the basis of the specific frequency. As already explained above, the frequency can be determined in particular by means of filters or other suitable frequency analysis measures. In particular, the frequency analysis means can accordingly then also provide for a transfer of the measurement signal into the frequency space in order to then be able to determine the rolling parameter from the measurement signal transferred into the frequency space.

[16] In addition, the peripheral speed, the rotational frequency and / or the rolling speed of at least one of the rollers can be used to determine the rolling parameter. This enables a comparison in the evaluation of the measurement signal with other rolling parameters that are relatively precisely accessible in order to be able to determine online the rolling parameters to be determined, which otherwise may only be very difficult to access. It goes without saying that, if necessary, variables proportional to the circumferential speed, the rotational frequency and / or the rolling speed can also be used accordingly for the fatigue of the rolling parameter to be determined. Here it is usually ultimately a question of the conversion constants, which then enable the measurement signals to be assigned to one another in order to determine the respective rolling parameter.

[17] The circumferential speed v _{roll of} a roller can be calculated relatively easily according to the formula: Transfer into the frequency domain and _{express it in terms of the rotational frequency f roll} - and vice versa. With regard to the rolling speed of a roller, this can be done in a similar manner, although this is relatively difficult to detect directly in terms of measurement technology. It goes without saying, however, that other rolling parameters, such as pressure forces acting on the rolls, roll calibres measured in any way, and adjustment positions of the rolls, can be used accordingly to determine the rolling parameter sought.

[18] During rolling, if the rolling process is designed accordingly, material of the rolling stock can be shifted along its longitudinal extent. This then has the consequence that the rolling stock is behind a roll stand, with which this deformation is applied, usually moved at higher rolling stock speeds V _rod than the peripheral speed or unwinding speed of the rollers of the corresponding rolling mill. This effect called “advance K” relates the circumferential speed v _{roll of} the corresponding roll or rolls to the rolling stock speed V _{rod of} the rolling stock behind the associated roll stand which takes into account that the rolling stock speeds V _{rod of} the rolling stock is then greater than the circumferential speed v _{roll of} the corresponding roll, so that the lead K _{f is} usually positive, also in the frequency domain can be transferred.

A factor of -1 must be taken into account here, since the frequency of the cross-sectional area change of the rolling stock, which is to be assigned to the rolling stock speed V _{rod of} the rolling stock, is then smaller than the frequency f _{roll of} the unwinding of the roll, _{i.e. the peripheral speed V roll} which would otherwise lead to a negative lead K _f in this context. In more rare cases, the advance Kr can also be negative, which would, however, also lead to the factor (-1) in order to be able to correctly map the relationships in equations (2) and (3).

[20] By equating the advance Kr the rolling stock speed V _{rod of} _{the rolling stock behind a roll} stand can then be determined on the basis of the frequency f roll, which was determined from the measurement signal, or on the basis of the measurement signal transferred into the frequency space.

[21] It is also understood that the advance K _r can be determined directly online as a rolling parameter. [22] As a further rolling parameter, or as a further measurement signal, which must be used for this purpose, only the peripheral speed v _roll or the rotational frequency f _roll or, if applicable, the rolling speed is to be determined, such determinations ultimately already well known from the prior art are.

[23] Accordingly, both the advance Krals and the rolling stock speed V _{rod of} the rolling stock behind a roll stand - and if several roll stands are used, also for each individual roll stand - can be determined. This also means that train changes can be detected online. It is also conceivable to determine changes in the coefficient of friction and / or flow path online. All of these variables are currently only available offline, and thus - naturally - not even between the individual roll stands.

It goes without saying that, in particular by measuring a rolling stock size that is variable along the longitudinal extension of the rolling stock, in particular if it is introduced into the rolling stock with the periodicity of one or more rolls, and transferring the corresponding measurement signal into the frequency space, a frequency analysis of the corresponding Measurement signals and / or determination of a frequency inherent in the rolling stock size from the measurement signal also enable further new aspects for online or in-situ diagnosis of a rolling process. In particular, this diagnosis can be carried out in a simple and operationally reliable manner and, with an appropriate design, also very quickly, so that the results can also be used online or in situ to control or regulate the rolling process.

It is well known from the prior art to control at least one of the rolls in a rolling mill via a control device. This can be, for example, a roll adjustment, by means of which the rolls can be adjusted towards the rolling line or away from it, in order to influence the rolling pass in this way. A corresponding adjustment can take place, for example, by applying certain forces or by positioning the rollers accordingly. The control device can also enable a roller drive and thus an adaptation of the circumferential speed, the rotational frequency or the rolling speed. In the present context, a control device comprises in particular all means and devices of a rolling mill with which the behavior of the rolls in relation to the rolling stock can be changed, preferably changed in a targeted manner. [26] A control device for at least one of the rollers is preferably operatively connected to the determination device, so that the determined rolling parameter and / or the specific frequency can be used as control parameters for the control device. Here, too, it is ensured that the peripheral speed, the rotational frequency and / or the rolling speed or a variable proportional to this, as well as other rolling parameters in this regard, can be used for the control.

[27] In particular, it is advantageous if the control device and the determination device are operatively connected to one another in a control loop, so that the control of the corresponding roller is via a control circuit that uses the measurements of the determination device and / or the determined rolling parameters for the control can be regulated.

It goes without saying that, if necessary, several or all of the rolls of the corresponding rolling mill can be activated or regulated accordingly.

[29] The measuring device is preferably arranged to be stationary with respect to the rolling mill, at least during rolling. This enables the rolling stock to be guided past or passed through the measuring device relatively quickly and still relatively accurate measured values to be recorded. In addition, predictably reliable measurement results are available, which can then also provide the respective rolling parameters online in a correspondingly simple and operationally reliable manner.

[30] It is also advantageous, cumulatively or alternatively, if the measuring device measures integrally and / or averages over the circumference of the rolling stock perpendicular to the rolling line. This also enables a relatively quick and operationally reliable measurement, even if this means that a spatial resolution, which would otherwise be possible around the circumference of the rolling stock, is dispensed with.

[31] In particular, the frequency analysis explained above, the transfer of the measurement signal into the frequency domain or the frequency determination from the measurement signal nevertheless make it appear possible to use such integrating or averaging measurements to determine the influence of one of the two rolls or all of the rolls of a roll stand - and in the case of a deeper analysis possibly even the influence of rolls which are provided on further preceding rolling stands or even on upstream rolling mills, or of other devices acting on the rolling stock, in order to determine the rolling parameters to be determined accordingly, or even just to determine more precisely can. [32] The measuring device can in particular comprise an eddy current sensor and / or an impedance measurement, since such measuring methods are particularly suitable for adverse environments such as are regularly found in rolling mills. It goes without saying that other measuring devices can also be used alternatively or also cumulatively, which can accordingly ultimately be determined by the rolling parameter to be determined, which ultimately determines the size of the rolling stock that is to be measured for determining this rolling parameter.

[33] In particular, an impedance measurement has proven to be advantageous since such a measurement can be implemented in the form of a coil surrounding the rolling stock in a plane perpendicular to the longitudinal extension of the rolling stock, which leads directly to a measurement result integrating and / or averaging over the circumference of the rolling stock leads. In addition, such an impedance measurement can also be carried out in close proximity to the rolls or between roll frameworks, although the conditions there are very adverse, such as high temperatures, a lot of scale, a lot of dust or a lot of steam, and very limited spatial conditions.

[34] At least two measuring devices are preferably arranged along the rolling line, which can accordingly enable a more precise measuring result. In particular, it is conceivable that one of the measuring devices can be arranged in front of and one of the measuring devices behind the respective roll stand, so that the rolling stock size, which changes along the longitudinal extent of the rolling stock, can be measured in front of a corresponding roll stand and after this roll stand. This then enables a corresponding comparison so that, if necessary, an even more precise determination of the corresponding rolling parameter becomes possible.

[35] It goes without saying that - depending on the specific requirements - corresponding measuring devices can be provided between roll frames if the rolling line has several roll frames. It is also conceivable that only one measuring device can be provided at the end of the corresponding rolling line if this appears sufficient.

[36] Depending on the specific requirements, the measures explained above or, in particular, the frequency analysis explained here, the transfer of the measurement signal into the frequency domain or the frequency determination from the measurement signal explained here can be combined with further results, such as those of M . Radschun, A. Jobst, O. Kanoun, J. Himmel ("Non-contacting Velocity Measurements of Hot Rod and Wire Using Eddy-Current Sensors", 2019 IEEE Workshop 2019, Mülheim ad Ruhr) explained correlations of measurement results in the time period, or with other measurement results or rolling parameters determined from them, in order to be able to determine further statements about the rolling process or to determine further rolling parameters. It is conceivable here that these further determination results or rolling parameters are not obtained in the frequency domain and only then transferred to the frequency domain. It is also conceivable that before further processing of the frequency analysis or the frequency analysis explained here, the transfer of the Mcsssignal to the frequency space or the frequency determination explained here from the measurement signal transfers them again from the frequency space to the time period and only there then further processed.

In particular, it is also conceivable that when using several measuring devices, for example between the roll stands or before and after a roll frame, the respective measurement signals in the frequency domain hzw. can be correlated after a frequency analysis. It is also conceivable to correlate such measurement signals according to the frequency determination explained above or with regard to their correspondingly determined frequency. Such correlations can also provide further information about the rolling process, that is to say serve to determine one or more further rolling parameters.

In the present case it is advantageous if the rolling stock is a rod, a wire or a tube. With such a selection of the rolling stock, integrating and / or averaging measurements over the circumference of the rolling stock can be implemented in a structurally relatively simple manner. The exact cross-sectional shape of the rod. Wire or pipe does not appear to be essential here if, for example, an impedance measurement or similar integrating or averaging measurements are to be carried out. In addition, rods or tubes are usually often subject to rolling processes, so that the present invention appears to be widely applicable here. In particular, larger rolling stock or larger semi-finished products, such as slabs, blocks, hollow blocks, blanks, hollow blanks, can also be accordingly rolled instead and also measured accordingly with regard to their rolling stock size.

[39] On the other hand, it goes without saying that flat material such as sheet metal or strips can certainly also be used as rolled material, provided that the associated measuring device is selected accordingly.

[40] The rolling stock is preferably metallic, since, particularly in the case of metallic rolling stock, corresponding rolling processes take place under extremely adverse environmental conditions, so that here also correspondingly difficult rolling parameters, in particular for controlling Rolls or otherwise used in a control loop can be determined. However, it is precisely metallic rolling stock that enables an impedance or eddy current measurement, for example by means of a coil surrounding the rolling stock located on the rolling line.

[41] In the present context, when performing the frequency analysis, in particular in the frequency domain, and / or when determining the frequency, it should be noted that the measured rolling stock size is preferably introduced into the rolling stock at a frequency corresponding to the rotation of the rolls to rolling stock sizes, which are introduced into the workpiece by the workpiece's own rotation, for example, leads to significantly higher frequencies of the corresponding rolling stock sizes, which may also be determined by the devices or methods explained here, but then not about the determination the natural rotation frequency goes, which naturally cannot represent a rolling stock size that is variable over the longitudinal extent of the rolling stock.

As already indicated above, any corresponding size of the rolling stock can be used as the variable rolling stock size along the longitudinal extension of the rolling stock, as long as it is sufficiently influenced by the rolling process, in particular by the rolls. In particular, the rolling stock sizes variable along the longitudinal extension of the rolling stock come into question, which bring about periodic changes in the rolling stock caused directly by the rolling process of the associated rollers on the rolling stock or which are introduced into the rolling stock by the rolling of at least one of the rollers on the rolling stock. Such periodic changes can be caused, for example, by defects in the rolls, by out-of-roundness or by natural frequencies or internal stresses of the respective roll or of the associated roll stand.

[43] It goes without saying that the features of the solutions described above or in the claims can optionally also be combined in order to be able to implement the advantages cumulatively.

[44] Further advantages, objectives and properties of the present invention are explained with reference to the following description of exemplary embodiments, which are also shown in particular in the attached drawing. In the drawing show:

FIG. 1 shows a first rolling mill in a schematic side view; FIG. 2 shows a second rolling mill in a schematic side view;

FIG. 3 shows a third rolling mill in a schematic side view; and FIG. 4 shows, by way of example, the frequency spectrum of a steel-shaped rolling stock which is measured with a measuring device of the rolling mills according to FIGS. 1 to 3 can be included.

The rolling mills 10 shown in FIGS. 1 to 3 each have roll stands 11 which carry rolls 12 and can roll a rolling stock 20 in the rolling direction 14 along a rolling line 13.

Here, the rolling mill 10 according to FIG. 1 only has one such rolling frame 11, while the rolling mills 10 according to FIGS. 2 and 3 each have five such rolling stands 11. In different embodiments, other numbers of rolling frames 11 can be provided, the distances between the rolling stands 11 and the number of rollers 12 carrying the respective rolling stands 11 and their arrangement around the rolling line 13 depending on the specific rolling mill 10 .

The rolling mill 10 of the present exemplary embodiment each comprises a stand 16 on which the rolling stands 11 are held. It goes without saying that, depending on the specific rolling mill 10, the stand 16 can be designed as a part of the building, as a roll stand support, as a frame or the like.

For each rolling frame 11, the rolling mills 10 have a control device 15 by means of which the rolls 12 can be controlled. In the present exemplary embodiment, the control devices 15 each comprise adjusting means, by means of which the rolls 12 can be adjusted perpendicular to the rolling line 13 in order to adapt them to a specific roll diameter or to a specific rolling stock 20. In addition, the control devices 15 also include a drive for the rolls 2 so that they can drive the rolling stock 20 through the rolling mill 10 along the rolling line 13 in the rolling direction 14.

It goes without saying that, depending on the specific configuration, the corresponding rolling mill 10 can also have differently effective control devices 15, for example for only some of the rolls 12, brakes, cooling, heating or the like, which can accordingly influence the rolling process. In particular, not all of the rollers 12 need to be driven; rather, it is conceivable that the rollers 12 may also simply run with them.

The rolling mills 10 are each designed for rolling stock 20, which extends in a longitudinal extension 21 which is oriented essentially parallel to the rolling line 13. In the actual rolling process, attempts will be made to establish the longitudinal extension 21 of the rolling stock 20 to align as possible on the rolling line 13. However, minor deviations cannot be ruled out here due to unavoidable tolerances and possibly due to the cross section of the rolling stock 20.

[51] As such, the rolling mills 10 can easily be used for sheet-like or strip-shaped rolling stock 20. In the present case, however, the rolling mills 10 are designed for, in particular, rod-shaped, wire-shaped or tubular rolling stock 20.

The rolling mills 10 each have determination devices 30 for online determination of at least one rolling parameter.

In this case, the determination device 30 comprises at least one measuring device 31, which is provided behind a roll stand 11. In the rolling mill 10 shown in FIG. 3, a measuring device 31 is also provided - by way of example - in front of the first rolling stand 11 in the rolling direction 14.

The measuring devices 31 are designed to interact with a rolling stock size of the rolling stock 20 that is variable along the longitudinal extension 21 of the rolling stock 20 and to output a corresponding measurement signal 40.

In the present exemplary embodiment, the measuring devices 31 carry out an impedance measurement through a coil which is aligned perpendicular to the rolling line 13 and which surrounds the rolling line 13 - and therefore also the rolling stock 20 when it runs along the rolling line 13. In this way, an impedance measurement can be carried out, which ultimately represents a direct measure of the respective cross-sectional area of the rolling stock 20, so that in this exemplary embodiment the change in cross-sectional area of the rolling stock 20 as it passes the respective measuring devices 31 or as it passes through the respective measuring devices 31 determining rolling parameters. In this change in cross-sectional area, the influences of rollers 12 or also of other tools that act or have acted on the rolling stock 20 can be found variable over the longitudinal extent 21 of the rolling stock 20.

[56] It goes without saying that in the case of alternative rolling stock 20, other rolling stock sizes may also be relevant or differently designed measuring devices 31 may be used.

[57] Via frequency analysis means 32 of the determination device 30, for example by transferring the corresponding measurement signal 40, as shown by way of example in FIG. 4, into a frequency space As a result, a specific frequency 41 inherent in the change in the size of the rolling stock, i.e. the cross-sectional area, can be determined. This frequency, which is clearly visible in FIG. 4, can then be used to determine the rolling parameter rolling stock speed V _{rod of} the rolling stock 20 in accordance with equation (8) or the rolling parameter advance Kr in accordance with equation (3) - for each individual roll stand 11, in this respect as well the circumferential speed v _{roll of} the corresponding rollers 12, which are upstream of the respective measuring device 31, or their rotational frequency f _roll , measured accordingly, taking into account equation (1). If necessary, changes in tension or changes in the coefficient of friction and flow separation can also be determined online accordingly.

[58] It goes without saying that, in different embodiments, a more precise analysis of the measurement signal 40 can be carried out in order to be able to determine further or alternative rolling parameters. If necessary, further measuring devices or other measuring devices can be provided for this purpose.

It is also conceivable that the measurement signals 40 of the measurement devices 31 are used for other purposes, for which purpose a bus 34 is provided in the exemplary embodiment in FIG. 2, which contains individual computing units 33, in which the frequency analysis means 32 of the individual roll stands 11 and an output unit is implemented to the control device 15 connects. In this way, in particular the measurement signals 40 of a measurement device 31 or the rolling parameters determined by a computing unit 33 can also be made available to other computing units 33.

In the embodiment shown in FIG. 3, a central processing unit 33 is used to output signals to the control device 15, while a central frequency analysis means 32, which is separate from the processing unit 33, analyzes all measurement signals from the measurement devices 31 accordingly.

It goes without saying that in different embodiments different and almost any combinations of bus 34, arithmetic logic units 33 and frequency analysis means 32 can be provided, since in the end all that matters is that corresponding frequency analysis means 32 and arithmetic units 33 are used for the respective measuring devices 31 Must be available.

[62] It goes without saying that - depending on the specific configuration of the respective computing unit 33 - this can include without further frequency analysis means 32. It is also conceivable that a separate computing unit contains the frequency analysis means 32. It is too It is conceivable that the signal forwarding of the respective arithmetic unit 33 to the control device 15 or the control devices 15 can take place by a separate arithmetic unit 33 or by a computer unit 33 that is used several times or in addition to that.

List of reference symbols:

10 rolling mill

11 roll stand 30 detection device

12 Roll 31 Measuring device 13 Roll line 15 32 Frequency analysis means

14 Rolling direction 33 Computing unit

15 Access device 34 Bus

16 Stand of the rolling mill 10

40 measurement signal 20 rolling stock 20 41 specific frequency

21 Longitudinal extension of the rolling stock 20

Claims

Patent claims:

1. A method for online determination of at least one rolling parameter when rolling a rolling mill (10) which includes at least two rolls (12) on a rolling stand (11) along a rolling line (13) and in which the rolling stock (20 ) is passed or passed through at least one measuring device (31) during rolling, which interacts with a rolling stock size of the rolling stock (20) that is variable along the longitudinal extension (21) of the rolling stock (20) and outputs a measurement signal (40), thereby marked,

(i) that the measurement signal (40) is transferred into the frequency space and the rolling parameter is determined from the measurement signal (40) transferred into the frequency space and / or

(ii) that a frequency (41) inherent in the change in the size of the rolling stock is determined from the measurement signal (40) and the rolling parameter is determined using the determined frequency (41).

2. Determination method according to claim 1, characterized in that the circumferential speed, the rotational frequency and / or the rolling speed of at least one of the rollers or a variable proportional thereto is additionally used to determine the rolling parameter.

3. Determination method according to claim 1 or 2, characterized in that at least one of the rollers (12) of the roll stand (11) as a function of the specific frequency (41) and / or the determined rolling parameters and possibly on the peripheral speed, the rotation frequency and / or the rolling speed of at least one of the rollers (12) or a variable proportional to this is controlled.

4. Rolling mill (10) comprising at least two rolls (12) arranged on a roll stand (11) for rolling rolling stock (20) along a rolling line (13) and a device (30) for online determination of at least one rolling parameter, the determination device (30) comprises at least one measuring device (31) which is arranged on the rolling line (13) and which is provided with a measuring device (31) along the longitudinal extension (21) of the Rolling stock variable rolling stock size of the rolling stock (20) can interact and output a measurement signal (40), characterized in that the determination device (30) comprises means (32) for frequency analysis.

5. Rolling mill (10) according to claim 4, characterized in that a control device (15) for at least one of the rollers (12) is operatively connected to the determination device (30).

6. rolling mill (10) according to claim 5, characterized in that the control device (15) and the determining device (30) are operatively connected to one another in a control loop.

7. Determination method according to one of claims 1 to 3 or rolling mill (10) according to one of claims 4 to 6, characterized in that the measuring device (31) is arranged stationary with respect to the rolling mill (10) at least during the rolling.

8. Determination method according to one of claims 1 to 3 and 7 or rolling mill (10) according to one of claims 4 to 7, characterized in that the measuring device (31) perpendicular to the rolling line (13) over the circumference of the rolling stock (20) integrating and / or averaging and preferably comprises an eddy current sensor and / or an impedance measurement.

9. Determination method according to one of claims 1 to 3, 7 and 8 or rolling mill (10) according to one of claims 4 to 8, characterized in that at least two measuring devices (13), preferably one in front and one behind, along the rolling line (13) the roll stand (11) are arranged.

10. Determination method according to one of claims 1 to 3 and 7 to 9 or rolling mill (10) according to one of claims 4 to 9, characterized in that the rolling stock (20) is a rod or a tube and / or metallic.