EP1372875A1

EP1372875A1 - Method for operating a mill train and a correspondingly embodied mill train

Info

Publication number: EP1372875A1
Application number: EP02719952A
Authority: EP
Inventors: Jürgen Seidel
Original assignee: SMS Demag AG
Current assignee: SMS Siemag AG
Priority date: 2001-03-31
Filing date: 2002-02-28
Publication date: 2004-01-02
Anticipated expiration: 2022-02-28
Also published as: WO2002078872A1; CZ305146B6; CN1500016A; ATE276055T1; US6983631B2; KR100841261B1; EP1372875B1; DE50201031D1; RU2003131972A; UA76143C2; DE10116273A1; KR20040011491A; JP2004529773A; BR0207557A; BR0207557B1; CN1235696C; CA2440210A1; CZ20032399A3; CA2440210C; ZA200305566B

Abstract

The invention relates to a mill train ( 1 ) for milling a strip-type product to be milled ( 10 ). Said mill train comprises a number of roll stands ( 2 ) which are successively arranged in a milling direction (x) and which can be respectively pivoted about a rotational axis ( 18 ) which is essentially perpendicular to the milling direction (x). The aim of the invention is to maintain a belt run which favors a pre-determined milling result, in an especially simple and reliable manner. According to the invention, a control value (S) is pre-determined for the pivoting angle of a roll stand, or of each roll stand ( 2 ), according to the determined contour of the strip end ( 30 ) of a product ( 10 ) which has already been milled. According to the invention, additional control elements can also be used.

Description

Method for operating a rolling mill and a correspondingly trained rolling mill

The invention relates to a method for operating a rolling train for rolling a strip-like rolling stock with an edger and a number of rolling stands arranged one behind the other as seen in a rolling direction, each of which is assigned an actuating unit for influencing the contour of the strip end of the rolling stock. It also relates to a rolling mill of this type, which can in particular also be equipped on the inlet side with an edger for reducing the width of the rolling stock.

A number of roll stands can be used in a rolling mill for rolling a rolling stock. The rolling stands, which are usually designed as so-called multi-roll stands and comprise a number of work rolls and, if necessary, a number of back-up rolls, are provided for the passage of a usually elongated rolling stock and are arranged one behind the other as seen in a driving direction of the rolling stock, also referred to as the rolling direction. A rolling mill with a plurality of such rolling stands can be used in particular when processing a strip-like rolling stock or strip. In this case, the strip-like rolling stock is designed in the manner of a primarily two-dimensional configuration as rolling stock extended in one extension plane with only a slight thickness in comparison to its dimensions in the extension plane.

The so-called strip run, that is to say the passage of the rolled material through the rolling stands, is of particular importance when processing such a strip-shaped rolling stock. During processing of the strip-shaped rolling stock, a train also known as a strip tension occurs within the rolling stock. The belt tension usually has a stabilizing effect on the egg actual tape run. In the case of machining that is asymmetrical with respect to the longitudinal central axis of the belt, however, the belt tension can also occur off-center. As a result, the strip can be deflected to the side, for example when the strip emerges from the rear rolling stand, as viewed in the rolling direction. In addition, the forces acting on the rolling stock off-center as a result of the strip tension can lead to a behavior of the strip end that deviates from the actual rolling stock, which in turn can lead to rolling errors.

In order to be able to suitably control the strip travel or the passage of the strip-like rolling stock through the rolling stands, which is relevant for the rolling result, the rolling stands can each be designed to be pivotable about an axis of rotation oriented essentially perpendicular to the rolling direction. By suitably pivoting one or each roll stand, the belt run can be influenced in such a way that asymmetrically occurring tensile stresses are kept particularly low, or that another specification for the belt run is met. Faults in the strip run, which can lead, for example, to rolled strip ends, damage to rolls and, in connection with this, the need for additional roll changes, are usually corrected by a helmsman by suitably swiveling the roll stands. The intervention options with regard to a particularly good rolling result are only limited, however, since corrective measures required in the rolling stands at the front as viewed in the rolling direction are difficult to detect due to the comparatively thick rolling stock there, and since the gaps between adjacent in the rolling direction are also seen Roll stands are also relatively difficult to see.

The invention is therefore based on the object of specifying a method for operating a rolling train of the type mentioned above, with which a strip run which is favorable for a given rolling result can be reproducibly maintained in a particularly simple and reliable manner. The aim is to create a rectangular, symmetrical tape end / tape head. Long tabs too and fish tails at the end of the belt should be avoided. In addition, a rolling mill that is particularly suitable for carrying out the method is to be specified.

With regard to the method, this object is achieved according to the invention by specifying a control value for one or each actuating unit assigned to a roll stand or an edger as a function of the determined contour of the strip end of an already rolled rolling stock.

The invention is based on the consideration that, for simple and reliable compliance with a given strip run, the influence on the strip run should be based on input variables which are particularly characteristic of the strip run preceding rolling processes. Thus, in the manner of a learning, self-adapting system, the influence on the strip run can be tracked on the basis of previous rolling results. As a basis for the evaluation of the previous rolling results, the material flow in an already finished rolling stock is provided, which occurs in each rolling stock depending on the swiveling amount of the rolling stands. This material flow is reflected in the manner of an effect accumulated over the entire length of the rolling stock, particularly in the area of the strip end. An evaluation of the contour of the strip end in the plane of extension of the strip-shaped rolling stock thus provides information which is particularly valuable for specifying the control values for the roll stands or the edger during the passage of the next rolling stock.

Advantageously, a control value for the swivel angle of one or each roll stand is specified as a function of the contour of the strip end of the rolling stock that has already been rolled. A suitable swivel value of the roll stands around their respective axis of rotation enables a specifically targeted influence on the strip travel. The information obtained by evaluating the contour of the strip end is advantageously also used for further correction interventions in the current rolling process. The calculation of the course of the bandwidth in the subsequent stands is particularly favorable, taking into account the belt extension. From the information now available with regard to the course of the strip width, when the roll bending behavior is known, correction values can be provided for the manipulated value characteristic of the work roll bending in one or each subsequent roll stand. Using these correction values, the manipulated values for the respective work roll bending can be specified in such a way that unevenness and / or strip rolling occur only to a particularly small extent.

Alternatively or additionally, the information obtained by evaluating the contour of the strip end is advantageously used in the operation of so-called loopers. With constant traction, e.g. As the width of the rolling stock becomes narrower, a locally higher tensile stress is created in the area of its strip end, which can undesirably lead to the strip being torn. Knowing the minimum width actually present as a result of evaluating the contour of the strip end, the tensile force with which the respective looper is applied can be reduced accordingly, so that such tearing can be avoided. On the other hand, in order to avoid long strap tongues at the strap end, the edger can also be assigned a separate actuating unit, by means of which, for example, long strap tongues are compensated for by increased width reductions at the strap end.

If the width of the rolling stock is influenced with the help of an edger, so-called fish tail ends can occur at the end of the strip, particularly with comparatively large width reductions, which are disadvantageous when the strip is being threaded out in the rear stands and can lead to warping. By evaluating the contour of the strip end, the formation of such fish tail ends can alternatively or additionally be recognized early, so that corresponding countermeasures in particular, corrective interventions on the edger can be carried out. In order to avoid long strap tongues at the end of the strap, the edger is provided as an actuator. Long strap tongues can be reduced by increasing the width of the abs. Band end to be fought.

As an alternative or additional correction intervention for the strip end shape, an influencing of the profile of the rolling stock can be provided. For this purpose, profile actuators, in particular in the rolling stands at the front as viewed in the rolling direction, can be subjected to manipulated values which are also predefined as a function of the determined contour of the strip end. This is based on the finding that an increase in the profile extends the strip edges, whereas a decrease in the profile extends the strip center. By suitably influencing the profile, the contour of the strip end can be influenced indirectly.

The contour of the strip end of the rolled material that has already been rolled can be detected at a suitable location within the rolling mill and with suitable means, for example using a number of width sensors. However, a contactless, in particular an optical, determination of the contour of the strip end is preferably provided, in which case a camera can be used in an advantageous embodiment. The contour of the strip end can be evaluated by determining the position of the maximum in the contour in the width direction of the strip-shaped rolling stock, the control value for the swivel angle being specified as a reference variable with regard to a predefinable target position for the maximum. In a particularly advantageous further development, however, the contour of the strip end is evaluated using a polynomial with which a number of measured values representing the contour of the strip end in their entirety are approximated.

The measured values can, for example, be digitized using an optical camera, the approximation by the polynomial being able to take place in a downstream computer module. By generating the Some polynomial, which approximates the measured values as best as possible, the contour of the strip end can be evaluated with a comparatively small number of parameters to be processed further. Especially when evaluating using such a polynomial, the so-called wedge portion of the band end contour can also be taken into account in a particularly favorable manner. The wedge is the measure by which the preferred direction of the contour of the strip end deviates from the width direction of the rolling stock. The wedge can alternatively be determined by evaluating the points at which the band ends and the contour of the actual band end. The evaluation and determination of these points is possible in a particularly favorable manner by using the polynomial.

In a further advantageous embodiment, in addition to the contour of the strip end, the contour of the strip head of the rolling stock that has already been rolled, as determined in the plane of extension, is also taken into account when specifying the control values for the roll stands. Because of the comparatively smaller material flow in the longitudinal direction of the rolling stock towards the strip head, the occurrence of possible errors in the selection of the swivel angle for the roll stands is less than in the contour of the strip end; taking into account the contour of the tape head nevertheless contributes very well to completing the information that can be evaluated for specifying the setting values for the swivel angle.

A further completion of the information on the suitable choice of the swivel angle can be achieved by, in an advantageous further development, when specifying the or each manipulated value for the swivel angle of the roll stands, a temperature profile of the rolling stock determined in the width direction of the strip and / or the strip profile in front of and / or behind the rolling train considered.

Fault in the belt run and an incorrectly set swivel angle of one

Depending on the thickness of the rolling stock, the rolling stand can have different effects on the rolling result. In order to take this into account, in an advantageous further development, when specifying the control value for a rolling The thickness of the rolling stock is taken into account when it passes through this rolling stand and / or the strip profile in front of and / or behind the rolling train.

As a result of the decreasing thickness of the rolling stock as it passes through the roll stands, influencing measures taken on a front roll stand, as seen in the rolling direction, can also have effects on the strip run in the rear roll stands, as seen in the rolling direction. In particular, when using the wedge of the strip as a guide variable for the adjustment of the swivel angle, a manipulated value specified for a rolling stand is taken into account in an advantageous development when specifying a manipulated value for one or each subsequent rolling stand seen in the rolling direction. When a control value for the swivel angle of a roll stand is specified, the subsequent roll stands in the rolling train are also swiveled, their tracking being provided for compensation for disturbances caused by the swiveling of the comparatively front roll stand. In a further advantageous embodiment, the manipulated value specified for a rolling stand is taken into account when specifying the manipulated value for the subsequent rolling stand in a dimension proportional to the intended decrease in the thickness of the rolling stock upon transition into this subsequent rolling stand.

In order to keep the asymmetrical tensile stresses in the roll stand particularly low when it is being processed, the or each control value for the pivot angle of the respective roll stand is advantageously adjusted in such a way that a contour of the strip end that is symmetrical with the longitudinal center axis of the rolling stock is established. It can be provided as a design criterion for a control system assigned to the rolling mill that the deviation of the contour of the strip end from an asymmetrical contour can be reduced to a minimum by suitably specifying the control values for the pivoting angles of the rolling stands. A predeterminable wedge shape or wedge shape of the strip in its extension plane or alternatively the position of the maximum of the contour of the strip end in the width direction can be provided as a guide variable for a control unit assigned to the rolling mill. The or each control value for the swivel angle of the respective roll stand is advantageously tracked in such a way that the contour of the strip end assumes its maximum in the width direction of the strip at a position which can be predetermined as the desired value.

A particularly high degree of flexibility in the processing of the rolling stock can be achieved by specifying the setpoint for the position of the maximum in the width direction or the setpoint for the strip end wedge in the extension plane in a particularly advantageous development depending on the position of the respective roll stand in the rolling mill. For example, an already asymmetrically formed strip-shaped rolling stock, viewed in the strip cross-sectional direction, can be processed in a particularly advantageous manner by initially adjusting the swivel angle in the front rolling stand, viewed in the rolling direction, in such a way that the wedge-shape of the incoming strip-shaped rolling stock is returned and the rolling stock thus is brought into a cross-sectional shape symmetrical to its longitudinal central axis. It is accepted that, due to the different material flow, an uneven strip lengthening of the rolled stock occurs in the width direction. However, due to the comparatively large thickness of the rolling stock in the front roll stand, such an uneven strip extension may be tolerable. In the subsequent rolling stands, as seen in the rolling direction, a symmetrical contour of the strip end can then be set in the plane of extension. Such a flexible specification of the setpoints or reference values for the control means that a rolling stock that is initially comparatively asymmetrical can thus be processed in a reliable manner with particularly low strip running errors to form a comparatively symmetrical end product. Different setpoints are also provided for the tape head, the tape center piece and the tape end. To support and / or monitor the rolling process, the strip cross-sectional profiles of the rolling stock entering and leaving the rolling mill are measured in an advantageous embodiment.

With regard to the rolling mill of the type mentioned above, the above-mentioned object is achieved with a control unit, which has a control value for one or each control unit assigned to a rolling stand or an edger, advantageously for the pivoting angle of one or each rolling stand, depending on the contour of the extension plane determined Specifies the end of the strip of a roll that has already been rolled. The control unit is expediently connected on the output side to actuating devices for adjusting the swivel angle.

For a reliable supply of suitable input parameters for the control unit, the control unit is advantageously connected on the input side to a number of measuring devices, each assigned to a rolling stand, for determining the contour of the strip end and / or the strip head of the rolling stock that has already been rolled in its extension plane. The measuring devices can, for example, be arranged in an elevated position on the associated roll stand, so that the contour of the strip end can be determined in a top view of the rolling stock.

Suitable width sensors can be provided to detect the contour of the strip end, by means of which the width of the rolling stock can be determined as a function of a longitudinal coordinate. The respective measuring device for a contactless measurement is preferably designed as an optical device, in particular as a camera.

In order to enable the temperature profile of the rolling stock to be taken into account when specifying the control values for the swivel angle of the rolling stands, the

Control unit in a further advantageous embodiment on the input side with a Temperature measuring device for determining the temperature profile of the strip in its width direction and / or connected to a number of strip cross-sectional profile measuring devices.

The advantages achieved by the invention consist in particular in that by taking into account the contour of the strip end of a previously rolled rolling stock in its extension plane when specifying the control values for the swivel angle of the rolling stands for the rolling process and the rolling result, disadvantageous incorrect settings when pivoting the rolling stands are particularly important simple and reliable way to compensate. In the manner of a learning or adapting system, the detection of the incorrect settings is provided on the basis of the evaluation of previous rolling results, the contour of the strip end, as a direct effect of the material flow in the strip-shaped rolling stock, making a particularly precise and reliable conclusion about possible incorrect settings in the pivoting angles of the roll stands allows. In addition, especially by specifying reference values for the adjustment of the swivel angle depending on the position of the respective roll stand in the rolling mill, particularly flexible processing of the rolling stock can take place, so that various types of preformed rolling stock can also be processed with reliably high rolling quality.

An embodiment of the invention is explained with reference to a drawing. In it show:

Figure 1 shows schematically a rolling mill with a number of roll stands, and

Figure 2 shows the strip end of a strip-shaped rolling stock in supervision.

Identical parts are provided with the same reference symbols in both figures. The rolling mill 1 comprises a number of roll stands 2, which are each designed as multi-roll stands in the exemplary embodiment. For this purpose, each roll stand 2 comprises a first work roll 4 and a second work roll 6, which together form a roll gap 8 and are designed for the passage of a rolling stock 10. The work rolls 4, 6 are each supported on their sides facing away from the rolling stock 10 by an associated support roll 12 or 14, which in turn is held in a roll stand, not shown in any more detail.

The rolling mill 1 is designed for the processing of a rolling stock 10 extended in the manner of a strip in an extension plane. The strip-like rolling stock 10 has a primarily two-dimensional shape. The so-called strip run, that is to say the passage of the rolled material 10 through the roll stands 2, is particularly important for the processing of such a strip-shaped rolling stock 10. Correspondingly, the rolling mill 1 is designed in such a way that the strip run can be influenced during the actual rolling process. For this purpose, each roll stand 2 is in each case adjustable or pivotable about an axis of rotation 18 indicated by a line in the figure and oriented essentially perpendicular to the rolling direction x indicated by the arrow 16. To set the swivel angle, that is to say a predeterminable orientation of the respective roll stand 2 with respect to its axis of rotation 18, each roll stand 2 is assigned an actuating unit 20, which represents an adjustment of the respective roll stand 2, which is not shown in detail.

The rolling mill 1 is provided with a control unit 22, which is provided, inter alia, for automatically influencing the swivel angle of the roll stands 2. For this purpose, the control unit 22 is connected on the output side to transmit an actuating value S via a data line 24 to the actuating device 20 of each roll stand 2. The rolling mill 1 and, in particular, its control unit 22 are designed for particularly reliable maintenance of a proper strip run during the rolling process. For this purpose, the control unit 22 is designed in such a way that it specifies the control values S for the swivel angle of the roll stands 2 as a function of the contour of the strip end 30 that has been determined in the plane of extent of a rolled material 10 that has already been rolled. An example of such a contour of the strip end 30 is shown in FIG. 2 for a strip-like rolling stock 10 in plan view. The rolling stock 10 is only shown in sections and in the area of its strip end 30. The contour of the strip end 30 in the plane of extent of the rolling stock 10 can have a comparatively irregular and asymmetrical shape in comparison to the longitudinal center axis 32 of the rolling stock 10. Such asymmetries can occur in particular as a result of incorrectly set pivot angles in one or more roll stands 2. An incorrectly set swivel angle can result in a locally different material flow in the longitudinal direction of the strip 10 compared to the other rolling stock 10. Such a locally different material flow is reflected in a cumulative manner, particularly at the strip end 30 of the rolling stock 10 in the form of an asymmetrical contour.

To determine the control values S for the actuating units 20 of the roll stands 2, the determination of the maximum of the contour of the strip end 30 in the width direction y of the rolling stock 10 can be provided in the control unit 22. In this case, the contour of the strip end 30 can be evaluated as a sequence of points. In this case, the control unit 22 could output the set values S for the swivel angle of the roll stands 2 in such a way that the maximum in the contour of the strip end 30 occurs in the manner of a symmetrical contour in a position in the immediate vicinity of the longitudinal central axis 32 of the rolling stock 10 , Alternatively, the contour of the strip end 30 could also be evaluated using spline functions.

In the exemplary embodiment, however, the contour of the strip end is evaluated

30 provided with the aid of a polynomial. A polynomial, the course 34 of which is shown in broken lines in FIG. 2, is selected in such a way that its

Course 34 the actual determined on the basis of a number of measured values Contour of the tape end 30 approximates as best as possible. In the mathematical determination of the polynomial, a greater weighting of the measuring points in the band center area 35 is advantageous. This polynomial can be used to further evaluate the contour of the strip end 30 with only a comparatively small number of parameters.

The position of the maximum 36 in the course 34 of the polynomial in the width direction y of the rolling stock 10 can be used as a guide variable for the specification of the control values S by the control unit 22. As an alternative, however, the so-called wedge of the band end 30 can also be determined as the reference variable. In this case, by evaluating the polynomial or also the individual measured values that reflect the actual course of the contour of the strip end 30, a preferred direction of the strip end 30, shown schematically in FIG. 2 by the line 38, is determined. Seen over the entire width of the rolling stock 10, this preferred direction corresponds to a length difference 40 on the outer sides of the rolling stock 10. This length difference 40 is thus a measure of the asymmetry of the strip end 30.

To determine the contour of the strip end 30, the rolling train 1, as shown in FIG. 1, is provided with a number of measuring devices 50. The measuring devices 50 can be configured, for example, as width sensors. In the exemplary embodiment, however, a contactless optical detection of the contour of the strip end 30 is provided. For this purpose, the measuring devices 50 are designed as optical devices, namely as cameras. The measuring devices 50 are arranged between two roll stands 2 at a height such that the contour of the strip end 30 can be determined in a plan view of the rolling stock 10. The control unit 22 is connected on the input side to the measurement devices 50 on the input side to take over the measured values supplied by the measuring devices 50 and characteristic of the contour of the strip end 30. In the exemplary embodiment, the measuring devices 50 designed as cameras are dimensioned and positioned such that the entire contour of the strip end 30, that is to say the contour across the entire width of the rolling stock 10, lies in the measuring range of the respective measuring device 50 and can thus be detected at the same time. Alternatively, however, for example as a result of differing external boundary conditions, for example in the case of very long strip tongues, one or each measuring device 50 can be positioned such that its measuring range does not cover the entire width of the rolling stock 10. In this case, it can be provided in the manner of a sequential scanning for the determination of the contour of the strip end 30 that the measuring device 50 concerned in each case records a series of partially overlapping individual images which in their entirety represent the complete contour of the strip end 30. These individual images are then combined into an overall image in an evaluation unit in such a way that they overlap in the respective overlapping areas. When the tape end 30 runs in the transverse direction, the respective images are shifted accordingly.

Furthermore, the control unit 22 is connected on the input side to a temperature measuring device 52. The temperature measuring device 52 is designed to determine a temperature profile of the rolling stock 10 in its width direction y.

In addition, the control unit 22 is connected on the input side to a first profile measuring device 54 and to a second profile measuring device 56. The profile measuring device 54 is arranged in the rolling direction of the rolling stock in front of the first roll stand 2 and is used to determine the cross-sectional profile of the rolling stock 10 entering the rolling mill 1. The profile measuring device 56, however, is arranged behind the last rolling stand 2 and viewed in the rolling direction of the rolling stock 10 Determination of the cross-sectional profile of the rolling stock 10 emerging from the rolling mill 1 is provided. When the rolling mill 10 is operated, the swivel angle of each roll stand 2 is adjusted by the control unit 22 in order to reliably maintain a strip run that is favorable for a high-quality rolling result. The rolling mill 1 is designed in the manner of a learning or adaptive system, whereby the control values S are specified taking into account the rolling result for rolled goods that have already been rolled. For this purpose, the contour of the strip end 30 of an already rolled rolling stock 10 is determined via the measuring devices 50. The contour can be determined for a rolling stock 10 that has left the rolling mill 1 as a whole, or also for a rolling stock 10 that has already emerged from one of the roll stands 2 but still has to pass through the subsequent roll stands 2.

When determining the contour of the strip end 30, the polynomial approximating the contour profile is generated on the basis of the measured values supplied by the measuring device 50. On the basis of this polynomial, it is checked for each roll stand 2 whether a reference variable provided for this roll stand 2 is within the tolerance range of a predefinable target value. The position of the maximum of the polynomial in the width direction y of the rolling stock 10 or also the length difference 40 characterizing the wedge nature of the rolling stock 10 can be evaluated as a reference variable. With regard to the corresponding predefined command variable, the control values S for the roll stands 2 are tracked in such a way that the corresponding target values are increasingly approximated.

In the exemplary embodiment, the control unit 22 generates correction values ΔS for the swivel angle of the roll stand 2 with the consecutive number i within the rolling train 1 according to the relationship.

In it state: \ the thickness of the rolling stock 10 on the roll stand 2 to be considered with the position number i,

ΔLJ: the wedge component or the length difference 40 of the rolling stock 10 on the roll stand 2 with the position number i,

U: a reference length dependent on the position number i of the roll stand 2, on which a material flow takes place in the rolling stock 10 in the rolling direction or in the longitudinal direction of the rolling stock 10,

fι: a factor for evaluating the material flow in the rolling stock 10 in its longitudinal direction,

f _u : in the manner of a swivel module, a conversion factor for converting a band wedge to a manipulated variable for the starting position.

The control unit 22 is additionally designed so that a control value for the swivel angle of a roll stand 2 is also taken into account when specifying the control values for the swivel angle of the subsequent roll stands 2. It is provided that the disturbance in the strip run caused by the pivoting of a roll stand 2 within the rolling mill 1 in the roll stands 2 following it is largely compensated for. The subsequent rolling stands 2 are also pivoted to a degree proportional to the thickness of the rolling stock 10 which decreases in the rolling direction.

The control unit 22 also specifies control values for the bending forces of the work rolls 4, 6, and is connected to the work rolls 4, 6, each associated control elements, not shown. These control values for the bending forces of the work rolls 4, 6 are also tracked and corrected on the basis of the determined contour of the strip end 30. For this purpose, the determined contour of the strip end 30 in the control unit 22 taking into account the Strip extension of the course of the strip in the subsequent rolling stands 2 is calculated. From these width parameters, taking into account the roll bending behavior, the control values for the bending force of the work rolls 4, 6 are specified in such a way that unevenness on the rolling stock 10 and thus strip rolling do not occur as far as possible.

In addition, the control unit 22 can also be designed to use the determined contour of the strip end 30 when specifying a tensile force for a looper and / or a control value for an upset, not shown, upstream of the rolling mill 1.

The method can be used not only on a rolling mill consisting of several stands, but also on reversing stands in which several passes are rolled.

LIST OF REFERENCE NUMBERS

1 rolling mill

2 roll stand

4, 6 work rolls

8 roll gap

10 rolling stock

12, 14 backup rolls

16 arrow

18 axis of rotation

20 control unit

22 control unit

30 band end

32 longitudinal central axis

34 course of the smoothing function (e.g. polynomial)

35 belt center area

36 maximum

38 line

40 Length difference or measure for the band end wedge in the extension plane

50 measuring device

52 Temperature measuring device

54, 56 profile measuring devices

S manipulated variable

X rolling direction y width direction i position number

Claims

claims

1. A method for operating a rolling train (1) for rolling a strip-like rolling stock (10) with an edger and a number of rolling stands (2) arranged one behind the other in a rolling direction (x), a number of actuating units (20) for influencing the Contour of the strip end (30) is used, characterized in that a control value (S) for one or each actuating unit (20) assigned to a roll stand (2) or an edger as a function of the determined contour of the strip end (30) of an already rolled one Rolled stock (10) is specified.

2. The method according to claim 1, characterized in that, depending on the determined contour of the strip end (30) of the rolled material (10), a manipulated value (S) for the pivot angle of one or each roll stand (2) by a substantially perpendicular to

Rolling direction (x) oriented axis of rotation (18) is specified.

3. The method according to claim 1 or 2, characterized in that the contour of the strip end (30) is determined optically.

4. The method according to any one of claims 1 to 3, characterized in that the or each manipulated variable (S) is predetermined on the basis of an evaluation of a polynomial, the number of which in its entirety

Contour of the strip end (30) approximates characteristic values.

5. The method according to any one of claims 1 to 4, characterized in that the determined contour of the strip head of the rolled stock (10) is taken into account when specifying the or each manipulated variable (S).

6. The method according to any one of claims 1 to 5, characterized in that a predetermined in the width direction (y) of the strip temperature profile of the rolling stock (10) and / or a in the width direction (y) of the Band determined thickness profile is taken into account.

7. The method according to any one of claims 1 to 6, characterized in that when specifying a control value (S) for a roll stand (2), the thickness of the rolling stock (10) is taken into account when it passes through this roll stand (2).

8. The method according to any one of claims 1 to 7, characterized in that a set value (S) for a roll stand (2) when specifying a set point (S) for one or each subsequent roll stand (2) seen in the rolling direction (x) is also taken into account.

9. The method according to claim 8, characterized in that for a roll stand (2) predetermined control value (S) when specifying the control value (S) for the subsequent subsequent roll stand (2) in an intended decrease in the thickness of the rolling stock (10 ) proportional dimensions are taken into account in the transition to this subsequent mill stand (2).

10. The method according to any one of claims 1 to 9, characterized in that the or each manipulated variable (S) is adjusted such that a symmetrical contour of the strip end (30) is set to the longitudinal central axis (32) of the rolling stock (10).

11. The method according to any one of claims 1 to 10, characterized in that the or each manipulated variable (S) is tracked such that the contour of the strip end (30) at a predetermined position in the width direction (y) of the strip a maximum ( 36) occupies.

12. The method according to claim 1 1, characterized in that a on the position of the respective roll stand (2) in the rolling mill (1) dependent setpoint for the position of the maximum (36) in the width direction (y) and / or for the wedge of the Contour of the band end (30) is specified.

13. Rolling mill (1) for rolling a strip-like rolling stock (10) with a number of rolling stands (2) arranged one behind the other as seen in a rolling direction (x), each of which an actuating unit (20) for influencing the contour of the strip end (30) is assigned , characterized by a control unit (22) which has a manipulated value (S) for one or each one

Rolling stand (2) or a setting unit (20) assigned to an edger as a function of the determined contour of the strip end (30) of an already rolled rolling stock (10).

14. rolling mill (1) according to claim 13, characterized in that the control unit (22), depending on the determined contour of the strip end (30) of the rolled material (10), has a manipulated value (S) for the swivel angle of one or each roll stand (2) oriented essentially perpendicular to the rolling direction (x) Axis of rotation (18) specifies.

15. Rolling mill (1) according to claim 13 or 14, characterized in that the control unit (22) on the input side with a number of measuring devices (50) each assigned to a roll stand (2) for determining the contour of the strip end (30) and / or the tape head is connected in the plane of extension.

16. Rolling mill (1) according to claim 15, characterized in that the or each measuring device (50) is designed as an optical device, preferably as a camera.

17. Rolling mill (1) according to one of claims 13 to 16, characterized in that the control unit (22) on the input side with a temperature measuring device (52) for determining a temperature profile of the rolling stock in its width direction (y) and / or with a number of profile measuring devices (54, 56) is connected to determine a strip profile in the width direction (y).

18. Rolling mill (1) according to one of claims 13 to 17, characterized in that the front rolling stands can be pivoted so that a wedge-free finished strip profile can be generated.

19. rolling mill (1) according to one of claims 13 to 18, characterized in that correction elements for the looper tensile force and the work roll bending force are provided as a function of the determined bandwidth.

20. Rolling mill (1) according to one or more of claims 13 to 19, characterized in that an upsetting stand is arranged in the rolling mill for the purpose of adjusting the optimized strip rectangle.

21. Rolling mill (1) according to claim 20, characterized by a monitoring unit of the maximum shrinkage in order to avoid fish tails.

22. Rolling mill (1) according to one or more of claims 12 to 21, characterized in that the rolling stands of the rolling mill have profile actuators for correcting the strip profile in order to be able to influence the strip end shape.