EP2340133B2 - Method for setting a drive load for multiple drives on a mill train to mill milled items, control and/or regulating device, storage medium, program code and mill train - Google Patents

Description

The invention relates to a method for setting drive loads for a plurality of drives of a rolling train for rolling rolling stock, the rolling train having a plurality of roll stands and each roll stand being assigned at least one drive for driving the work rolls comprised by the respective roll stand, the drive loads being based on an operation of the rolling mill according to a first pass schedule can be set substantially to a first target value. The invention also relates to a control and/or regulating device for a rolling mill and a rolling mill. In addition, the invention relates to a storage medium and a machine-readable program code.

The present invention lies in the technical field of rolling mill technology. The rolling of metal goods is usually used to produce semi-finished products, which are then used in the metalworking industry, for example in the automotive industry.

As a rule, a rolling mill must be able to produce a wide variety of metallic semi-finished products, which differ, for example, in the metal to be processed, in the structural properties of the steel to be processed and in the spatial dimensions, in particular the thickness.

In this respect, it is necessary for the operation of a rolling plant to be able to be switched over in such a way that, for example, strips with a wide variety of properties can be produced one after the other as quickly as possible, so that a high plant throughput is achieved. This is required for both hot rolling and cold rolling.

Such a conversion of the rolling operation has particular effects on the distribution of the drive loads for the drives of a rolling train. The drive loads depend on the thickness reductions of the rolling stock that take place on the roll stands, the temperature of the rolling stock to be rolled, the type of rolling stock, i.e. steel, copper, etc.

The Korean Disclosure Statement KR 2003004835-A discloses a method of automatically adjusting a load distribution for a continuous rolling mill. Target values for the load distribution are specified here, which are to be achieved when the desired outlet thickness is achieved.

The object of the present invention is to undertake an improved method for redistributing drive loads in a rolling train and to provide a corresponding open-loop and/or closed-loop control device, a program code, a storage medium and a rolling installation for this purpose.

The procedural part of the object is achieved by a method of the type mentioned at the outset, wherein during rolling the drive loads are adjusted in the direction of a second target value based on a second pass schedule that differs from the first pass schedule, wherein at least while the second target values are being set, an infeed speed of the Rolled stock is set in the rolling mill as a function of a discharge speed of the rolled stock of a unit arranged upstream in the mass flow direction of the rolling mill. In this case, the rolling stock is rolled to the same outlet thickness when the rolling train is operated according to the first pass schedule and when it is operated according to the second pass schedule. Furthermore, when carrying out the method according to the invention, the Automatic Gauge Control (AGC) is temporarily switched off for a respective roll stand of the rolling train. This avoids incorrect control interventions when redistributing the drive loads of the rolling stock.

As a rule, the second target value for the drive load for the respective drive is different from the first target value for the drive load of this drive. However, some of the drives of the rolling mill may receive a second target value based on the second pass schedule, which does not differ significantly from the amount of the first target value. This is the case in particular with drives for roll stands which are located at the start of the rolling train and, if necessary, should not experience any change in the drive load.

The entry speed to be set serves as a fixed, not arbitrarily adjustable input variable for the rolling mill, which is not influenced in particular by processes downstream of the first roll stand of the rolling mill in the direction of mass flow. Rather, the entry speed of the rolling stock in the rolling mill is dependent on an exit speed of the rolling stock of one or more units, which are preferably arranged exclusively upstream of the rolling mill in the direction of mass flow.

An actual exit speed of the rolling stock of a unit arranged upstream of the rolling train in the direction of mass flow is preferably used as the exit speed. Alternatively, a desired discharge speed of the rolling stock from a unit arranged upstream of the rolling train in the direction of mass flow can be used. Preferably, the run-out speed of that unit of the rolling mill is used which has the lowest time dynamics and therefore reacts more slowly to changes in its process than the other units to process changes occurring in these units. This unit with the lowest time dynamics usually represents the limitation with regard to the change in the infeed speed of the rolling train. Because this can no longer follow relatively fast changes in the infeed speed of the rolling train from a process-technical point of view.

A unit is a device in a rolling mill that treats, processes or produces a rolling stock and is indirectly or directly related to the rolling train. Examples of this are coilers, furnaces, roll stands, casting machines, shears, descalers, cooling lines, etc..

In previous methods for load redistribution in a rolling train, the entry speed is usually a variable manipulated variable, with which, for example, mass flow fluctuations or strip tension fluctuations in the rolling train - caused by the change in operation of the rolling train - is reacted to. This allows the by changing the drive loads caused deviations in process variables, such as the mass flow, are corrected.

However, the change in the entry speed may be propagated to the aggregates of the rolling mill located upstream in the direction of mass flow. Depending on the structure of the rolling mill, this can lead to not inconsiderable problems in the process control of the processes running on the aggregates upstream in the mass flow direction of the rolling train. Undesirable process slowdowns can occur in order to generate waiting times in order to avoid rolling stock collisions, e.g. in "batch operation", up to process terminations for aggregates arranged upstream in the direction of mass flow of the rolling train.

However, this can be avoided by the present invention by determining, adjusting and maintaining the infeed speed of the rolling stock in the rolling mill in such a way that an adjustment of a rolling stock outlet speed of a unit arranged upstream in the direction of mass flow to the infeed speed of the rolling mill is not required or is required to a lesser extent is. In this context, "to a lesser extent" means that the process of the unit upstream of the rolling train in the mass flow direction is only influenced by the change in the entry speed in such a way that the unit can cope with this process influence and there is no process interruption or process error in this unit.

In particular, the aggregates upstream of the rolling train in the direction of mass flow can be operated according to their setpoints without the setpoint values having to be corrected due to processes downstream in the direction of mass flow, for example due to a load redistribution in the rolling train.

In other words, the mass flow turbulences caused by the drive load redistribution in the rolling train can be completely cascaded out in the direction of mass flow by means of the invention. This means that cascading against the direction of mass flow - as is common today - is not absolutely necessary.

However, it is also possible to use a mixed cascading of mass flow fluctuations in the rolling train during the transfer in the direction of mass flow and against the direction of mass flow. For example, the infeed speed of the rolling stock in the rolling train is changed during the change in the drive loads in such a way that the upstream processes in the mass flow direction are changed in such a way that these can still follow the change in the infeed speed into the rolling train sufficiently quickly in terms of control technology, i.e. no irreversible process disruption in the rolling train in Mass flow direction upstream units takes place. In addition to the exit speed, the temporal dynamics of the most sluggish unit upstream of the rolling mill in the direction of mass flow are taken into account, i.e. how quickly and to what extent this unit can react to changes in the process without irreversible process disturbances occurring.

Any additional necessary corrections to the mass flow are then cascaded out in the direction of mass flow. This has the advantage that actuators are less heavily stressed during the drive load redistribution in the rear rolling mills in a mixed forward and backward cascading of process disturbances in the rolling train, since the reduced entry speed of the rolling stock into the rolling mill also reduces the rolling speed of the rolling stock at the rear rolling mills the rolling mill decreases. This can be significant, in particular for adjustment distances and for the accelerations on the individual roll stands.

The present invention is applicable to both hot rolling and cold rolling of metal strip.

It is also advantageous that the infeed speed is set to be essentially constant as a function of an outfeed speed of the rolling stock of a unit arranged upstream of the rolling train in the direction of mass flow. In this way, advantages according to the invention can be achieved in a particularly simple manner, in particular for slowly changing processes upstream of the rolling train. This is particularly advantageous in the case of composite casting and rolling systems, since the casting speed is generally constant and the casting unit is generally the unit with the lowest dynamic over time. In particular, this is also advantageous in rolling mills whose units are coupled to one another in terms of production technology by the rolling stock, i.e. the rolling stock is designed in one piece, for example from a casting unit to a coiler for coiling a hot strip.

In particular, the invention makes it possible to ensure a constant mass flow on the inlet side into the rolling mill. This leads to corresponding planning security and a smoother flow of the processes, which are arranged upstream of the rolling mill in the direction of mass flow.

A pass schedule usually reflects the thickness reductions and peripheral speeds of the work rolls for the respective roll stands of the work rolls. If the reduction in thickness for a roll stand is changed, the entire pass schedule of the rolling mill is inevitably changed. Either the change in the reduction in thickness on a roll stand due to the roll stands following it must be taken into account in order to provide a constant outlet thickness from the rolling train, or a change in the pass schedule results in one targeted change in the outlet thickness from the rolling train. In both cases, this has a direct effect on the drive loads of the drives assigned to the respective roll stands.

Rolling to the same exit thickness means that the exit thickness of the rolling stock from the rolling train is maintained using the method according to the invention while the rolling process is running, and at the same time the load distribution of the drives for the rolling stands of the rolling train is maintained - without an undesirable reaction on the rolling train upstream in the direction of mass flow aggregates done - can be optimized.

It is particularly advantageous that the method is carried out after a transfer from a first exit thickness of the rolling train to a second exit thickness of the rolling train that differs from the first exit thickness during the rolling of rolling stock in the rolling train.

The outlet thickness is understood to be the thickness of the rolled stock after the last roll stand of the rolling mill, and the inlet thickness is understood to be the thickness of the rolled stock before the first roll stand of the mill mill. The process is suitable for converting a thinner outlet thickness into a thicker outlet thickness and vice versa.

When the rolling stock is transferred from a first exit thickness from the rolling mill to a second exit thickness from the rolling mill, which is different from the first, pass schedule changes are usually made which take into account system restrictions, such as avoiding permanent overloading of the drives. When changing the operation of a rolling train according to a first pass plan to an operation of the rolling train according to a second pass plan during rolling, the boundary conditions due to mass flow disturbances in the rolling train are defined differently than in stationary operation of the rolling train.

This means that the invention can be used particularly advantageously if an exit thickness is initially used according to a first pass schedule, and then the exit thickness of the rolling mill is changed using a second pass schedule during rolling. The second pass schedule is calculated in such a way that a problem-free transition from the first outlet thickness to the second outlet thickness can take place. If the second exit thickness is set, a further pass plan change preferably takes place immediately such that the drive loads of the drives of the rolling train are optimized for stationary operation of the rolling train at the exit thickness according to the second pass plan. For this purpose, the second pass schedule is converted into a third pass schedule. In this example, the second pass schedule corresponds to the first pass schedule mentioned in claim 3 and the third pass schedule corresponds to the second pass schedule mentioned in claim 3 .

In particular, the combination of the process of "changing the exit thickness from the rolling train during rolling" with subsequent "pass schedule optimization with regard to the drive loads during rolling with a constant exit thickness" increases the operational reliability of the plant and has a positive effect on the service life of the drives.

The method can be used particularly advantageously if the rolling train and at least one unit arranged upstream of the rolling train in the direction of mass flow are coupled in terms of production technology by the rolling stock. The reaction to a change in the entry speed is particularly drastic here due to the load redistribution of the drives in the rolling mill. The rolling stock transmits the change in the entry speed directly to the unit upstream of the rolling train in the direction of mass flow, thereby disrupting the process running on this unit.

In particular, if the unit arranged upstream in the direction of mass flow is the casting unit, an excessively large or too rapid change in the entry speed into the rolling train can lead to disruptions in the casting process and even to the point at which the casting stops. Thus, the present invention can be used particularly advantageously for a combined casting and rolling plant, which is preferably operated in an "endless" mode, i.e. casting and rolling are carried out continuously.

The device-related part of the object is achieved by a control and/or regulating device for a rolling mill comprising a multi-stand rolling train, with a machine-readable program code which has control commands which, when it is executed, require the control and/or regulating device to carry out a method according to one of the Claims 1 to 3 cause.

The object is also achieved by machine-readable program code for a control and/or regulating device for a rolling mill, the program code having control commands which cause the control and/or regulating device to carry out the method according to one of claims 1 to 3.

In addition, the object is achieved by a storage medium with a machine-readable program code stored thereon according to claim 5.

Finally, the object is also achieved by a rolling mill with a multi-stand rolling train for rolling metallic rolling stock, with a control and/or regulating device according to claim 4, with a device for supplying the discharge speed of the rolling stock of a unit arranged upstream of the rolling mill in the direction of mass flow to the control - and/or regulating device according to claim 4, wherein the roll stands of the rolling train are operatively connected to the control and/or regulating device. A rolling plant is understood to be any plant which includes a rolling train, preferably for processing metallic rolling stock, in particular also cast-rolling composite plants.

In a further advantageous embodiment of the rolling installation, the rolling train is a high-reduction mill and/or a finishing train arranged downstream of a casting unit in the mass flow direction. In the present case, a high-reduction mill is a rolling train consisting of several stands, which rolls the rolling stock with a large reduction in thickness while it is still very hot. A distinction can be made between Liquid Core Reduction and Soft Core Reduction. As a rule, liquid core reduction is not used in a high-reduction mill, but soft core reduction of the rolling stock is. With Soft Core Reduction, the core of the rolling stock is already solid, but still very soft due to the high temperature of e.g. 1200°C to 1300°C. If the rolling stock in the High Reduction Mill still had a liquid core, the high forces in the High Reduction Mill would cause significant process disruptions. With the High Reduction Mill, large reductions in the thickness of the rolling stock can be achieved with soft core reduction with comparatively low rolling forces. The method according to the invention can be used advantageously for such a multi-stand high-reduction mill. In addition, the rolling train can alternatively or additionally be designed as a multi-stand finishing train, which rolls the rolling stock to the desired final dimensions.

FIG 1

eine schematische Darstellung einer kokillenbetriebenen Gießwalzverbundanlage,

FIG 2

eine schematische Ansicht einer Walzstraße mit vier Walzgerüsten, welche gemäß einem ersten Stichplan betrieben wird,

FIG 3

eine schematische Darstellung der Walzstraße aus FIG 2, welche gemäß einem zweiten Stichplan betrieben wird,

FIG 4

eine schematische Darstellung einer Gießwalzverbundanlage, welche eine Zweirollengießmaschine umfasst.

Further advantages of the invention result from an exemplary embodiment which is explained in more detail below with reference to the following diagrammatic drawings. Show it:

FIG 1

a schematic representation of a mold-operated cast-rolling compound plant,

FIG 2

a schematic view of a rolling train with four roll stands, which is operated according to a first pass plan,

3

a schematic representation of the rolling mill FIG 2 , which is operated according to a second pass schedule,

FIG 4

a schematic representation of a continuous cast-rolling system, which includes a two-roll caster.

FIG 1 shows a schematic representation of a combined casting and rolling plant 1. This comprises a rolling train 2, which is represented schematically and comprises a plurality of roll stands.

The method can be used for any multi-stand, in particular three-stand, four-stand, five-stand, six-stand and seven-stand rolling train and is in particular also not limited to composite casting-rolling plants.

Furthermore shows FIG 1 a casting unit 3, designed here as a permanent mold, which casts rolling stock G at a casting speed Vg, which is then rolled in the rolling train 2. This rolling stock G is processed continuously, ie there is no cutting of slabs or the like. Via the rolling stock G, the parts or assemblies of the rolling mill 1 that influence the rolling stock G are coupled to one another in terms of manufacturing technology. This means that these can no longer be operated independently of one another, but are generally to be operated with regard to the upstream and downstream units of the rolling mill 1 in the direction of mass flow, in particular with regard to those units with the lowest temporal dynamics or with the greatest inertia in reacting to process changes.

The casting unit 3 as well as the rolling train 2, possibly also further, in FIG 1 Aggregates of the combined casting-rolling system 1 that are not shown are operatively connected to a control and/or regulating device 8 .

The control and/or regulating device 8 is equipped to carry out an embodiment of the method according to the invention. For this purpose, machine-readable program code 10 is supplied to the control and/or regulating device, for example on a storage medium 9 . The program code 10 includes control commands which, when they are executed, cause the open-loop and/or closed-loop control device to carry out the embodiment of the method according to the invention. The program code is preferably stored in memory-programmed form on the control and/or regulating device 8 so that it can be called up without further ado.

In particular, the control and/or regulating device 8 can be supplied with a measure of the discharge speed of the rolling stock G from a unit arranged upstream of the rolling train in the direction of mass flow, for example the casting unit 3 . In the present example, the measure for the outlet speed is the casting speed Vg.

FIG 1 shows a schematically illustrated rolling train 2 in operation, the rolling stock G cast by the casting unit 3 at the casting speed Vg being rolled from an entry thickness He to an exit thickness Ha. The rolling stock G has an entry speed Ve into the rolling train 2 and an exit speed Va from the rolling train 2.

Using the method according to the invention, it is now possible to redistribute the load of the roll stands 4, 5, 6 and 7, see FIG 2 or. 3 , The rolling train 2 driving drives 20, 21, 22 and 23, see FIG 2 or. 3 to carry out such during the rolling of rolling stock G that the entry speed Ve and the exit speed Ve remain constant without producing rolling stock scrap caused by the redistribution of the drive loads.

If operation of a rolling train 2 is switched from a first outlet thickness Ha to a second outlet thickness Ha, which differs from the first outlet thickness, the load distribution of the drives is optimized in such a way that the transfer of the rolling operation from the first rolling train exit thickness Ha to a second rolling train exit thickness Ha, which differs from the first, takes place as easily as possible.

In this case, however, the drive loads of the drives 20, 21, 22 and 23 of the rolling mill 2 are not optimized for stationary operation of the rolling mill for the new second rolling mill outlet thickness, but rather for changing the outlet thickness Ha from the rolling mill 2 with as few problems as possible the present invention.

The load distribution of the drives of the rolling train 2 is initially not optimal for stationary operation of the rolling train 2 after a short previously performed on-the-fly change of the outlet thickness. Therefore, it is advantageous to redistribute the drive loads of the drives of the rolling mill 2 after the completion of the changeover of the outlet thickness Ha from the rolling mill 2 in such a way that there is a low probability of overloads or other restrictions, while at the same time achieving the desired outlet thickness, and therefore steady-state operation of rolling train 2 is optimized.

For this purpose, a new optimized pass schedule for the stationary operation of rolling train 2 is first determined. Pass schedule calculations are generally known, e.g DE 37 21 744 A1 or off DE 44 21 005 B4 . The new pass schedule is hereinafter referred to as the second pass schedule. The pass schedule according to which the rolling train 2 is operated directly after the on-the-fly change in the exit thickness Ha in order to produce the new exit thickness Ha is referred to below as the first pass schedule.

Linked to the determination of the second pass plan is a determination of the target values of the drive loads for the drives 20, 21, 22 and 23 of the work rolls of the roll stands 4, 5, 6 and 7. The second pass plan is determined in such a way that the desired outlet thickness Ha is achieved and at the same time the drive loads of the drives 20, 21, 22 and 23 of the rolling train 2 are optimized, i.e. in particular they are operated with the greatest possible distance from critical limit values.

In the present case, the outlet thickness Ha of the rolling mill 2 remains constant during operation according to the first pass schedule and during operation according to the second pass schedule, i.e. immediately before, during and after the redistribution of the drive loads of the drive 20, 21, 22 or 23 of the rolling mill 2 becomes the same Outlet thickness rolled from the rolling train 2. This is the subject of the present invention.

According to the invention, when the drive load of the drives 20, 21, 22 or 23 is set, the entry speed Ve of the rolling stock G into the rolling train 2 is set as a function of an exit speed Vg of the rolling stock G of a unit 3 arranged upstream of the rolling train 2 in the direction of mass flow. This ensures that during the changeover of the drive loads of the drives 20, 21, 22 or 23 of the rolling train 2, the processes of the units arranged upstream of the rolling train 2 in the direction of mass flow, for example the casting unit 3, are not disturbed.

The entry speed Ve into the rolling train 2 is preferably kept constant during the redistribution of the drive loads of the drives 20, 21, 22 and 23 in the rolling train 2. As a rule, the mass flow through the combined casting-rolling system 1 is constant, since the casting speed Vg of the casting unit 3 is generally attempted to be kept constant. For this reason, such an embodiment of the solution is technically simple.

In order to use this advantage, it is particularly advantageous to also set the entry speed Ve of the rolling stock G into the rolling train 2 to a constant value, the amount of which is determined as a function of the casting speed Vg of the casting unit 3 . This ensures in a simple manner that the processes upstream of the rolling train 2 in the direction of mass flow are not disturbed.

When the drive loads for the drives 20, 21, 22 or 23 of the rolling train 2 are redistributed, there is usually also a redistribution of the reduction in thickness on the respective roll stands 4, 5, 6 or 7 of the rolling train 2.

This is usually associated with a thickness wedge, which is caused by a change in the outlet thickness H1, H2, H3 - see 2 and 3 , occurs during rolling.

Therefore, before the redistribution of the drive loads of the drive 20, 21, 22 or 23 is carried out, a redistribution section of the rolling stock G is determined, during the rolling of which in the respective roll stand 4, 5, 6 or 7 the redistribution of the drive loads of the respective drives 20, 21, 22 and 23 of the rolling train 2 takes place. During the rolling of the redistribution section, the drive loads are each changed from their actual value in the direction of their new target value according to the second pass schedule. This preferably takes place as soon as the redistribution section enters the respective roll stand 4, 5, 6 or 7. The corresponding target values of the drive loads are reached when the redistribution section leaves the respective roll stand 4, 5, 6 or 7.

During the entire drive load redistribution process of the drives 20, 21, 22 or 23 of the rolling train 2, the redistribution section preferably has a length which is not greater than the distance between two rolling stands of the rolling train 2 from one another. This makes it possible to redistribute the drive loads in a particularly simple manner, since the thickness wedge of the rolling stock G that is present during the redistribution is not rolled simultaneously in two roll stands 4, 5, 6 and 7, respectively.

The outlet thickness Ha remains constant throughout the redistribution of the loads of the drives 20, 21, 22 and 23, respectively. That is, the mass flow disturbances caused by the redistribution of the drive loads are compensated for by at least one subsequent roll stand 4, 5 or 7 in such a way that the desired outlet thickness Ha is maintained.

2 and 3 show the same rolling mill 2, having the roll stands 4, 5, 6 and 7, which are associated with the drives 20, 21, 22 and 23, respectively.

The drives 20, 21, 22 and 23 are used to drive the unspecified work rolls of the roll stands 4, 5, 6 and 7 of the rolling train 2. The drives 20, 21, 22 and 23 are subjected to a corresponding drive load, see above that a desired reduction in thickness at the respective roll stand 4, 5, 6 or 7 or a desired rolling capacity at the respective roll stand 4, 5, 6 or 7 is achieved.

In FIG 2 the rolling train 2 is operated according to a first pass schedule. In 3 the same rolling train 2 is operated according to a second pass schedule. The outlet thickness Ha from the rolling train 2 is the same in both cases.

The operation of the rolling mill 2 in 2 and 3 differs only in that different thickness reductions take place for the roll stands 4, 5 and 6 during the operation of the rolling train 2 according to the first or second pass plan.

While the roll stand 4 according to the first pass plan, ie according to FIG 2 , which rolls the rolling stock G from a rolling stock thickness He to a rolling stock thickness H1, the same rolling stand rolls the rolling stock G from a thickness He to a thickness H1' during operation of the rolling train 2 according to the second pass schedule. In the present case, the thickness H1' is not equal to the thickness H1. The thickness H1' is selected in such a way that the drive load of the drives 20 assigned to the roll stand 4 is improved compared to operation according to the first pass schedule.

This is done analogously at the roll stand 5, which according to the first pass plan, ie according to FIG 2 , which rolls the rolling stock from a rolling stock thickness H1 to a rolling stock thickness H2. According to the second pass schedule, the same rolling stand 5 rolls an exit thickness H2' on the second rolling stand 5, starting from an entry-side rolling stock thickness H1'. Here, too, the thickness H2' is determined in such a way that the drive load of the drives 20 assigned to the rolling stand 4 is improved compared to operation according to the first pass schedule.

This is also done on the roll stand 6, which according to the first pass plan, ie according to FIG 2 , which rolls the rolling stock from a rolling stock thickness H2 to a rolling stock thickness H3. According to the second pass plan, the same roll stand 6 rolls an exit thickness H3' on the third roll stand 6 of the rolling train 2, starting from an entry-side rolling stock thickness H2'.

As an optimization criterion for the drive loads of the drives of the rolling train 2, for example, the sum of the distances between the drives of the rolling train and critical limit values can be minimized, with a corresponding outlet thickness Ha from the rolling train 2 being achieved.

It is not necessary for the drive load to be redistributed on each roll stand, and for this to be accompanied by a change in the reduction in thickness. The redistribution of the drive loads can also only take place for some of the roll stands or the drives assigned to the roll stands.

The individual roll stands are switched over successively according to the second pass schedule, specifically when passing through the redistribution section through the respective roll stand. Here, the Automatic Gauge Control (AGC) is temporarily switched off for a respective roll stand of the rolling mill.

In 3 the reduction in thickness at the roll stands is adjusted in such a way that the outlet thickness Ha is reached and at the same time the distance between the target values of the drive loads of the individual drives and the limit values that are not to be exceeded or not reached in stationary operation is at a maximum.

FIG 4 shows a further possibility for implementing the invention for a casting-rolling plant 1 comprising a two-roll caster 3', the cast rolling stock G then running through a multi-stand, ie at least two-stand, rolling train 2.

Rolling stock G is generally produced in endless operation by means of a two-roller casting machine 3'. The advantage of this type of system is that it is even more compact than a continuously working system that casts using a permanent mold. Furthermore, the consumption of energy and resources is further reduced.

The compactness and the reduced use of resources result from the fact that a twin-roller casting machine 3' can be used to cast even closer to the final dimensions of the desired end product. This means that the rolling stock emerging from the twin-roller casting machine G' is generally already significantly thinner than that from a permanent mold, cf. FIG 1 , exiting rolling stock G. As a result, a roughing train or high reduction mill, for example, which is usually downstream of a mold-operated casting machine, can be omitted. This serves to prepare the rolling stock cast from the mold for finish rolling. In the case of a twin-roller casting machine, however, such a forming preparation is generally not required, but only a finish rolling of the rolling stock G in the rolling train 2.

In this case, too, it may be desirable to redistribute the load for the in FIG 4 roll stands of the rolling train that are not shown during ongoing operation.

In order to achieve this, the statements on 1 to 3 analogously for a rolling installation 1 comprising a two-roll casting machine 6'.

Claims (9)

1. Method for setting a drive load for a plurality of drives (20, 21, 22, 23) of a mill train (2) for rolling rolling stock (G), wherein the mill train (2) has a plurality of rolling stands (4, 5, 6, 7), and each rolling stand (4, 5, 6, 7) is assigned at least one drive (20, 21, 22, 23) for driving the working rolls included in the respective rolling stand (4, 5, 6, 7), wherein the drive loads are essentially set to a first setpoint value on the basis of operation of the mill train (2) in accordance with a first pass sequence,
   characterized in that, during the rolling, the drive loads are adjusted in the direction of a second setpoint value which is based on a second pass sequence which is different from the first pass sequence, wherein at least during the adjustment of the second setpoint values a feed rate (Ve) of the rolling stock (G) into the mill train (2) is adjusted as a function of a discharge rate (Vg) of the rolling stock (G) of a unit (3) which is arranged upstream of the mill train (2) in the direction of mass flow, wherein the rolling stock (G) is rolled to the same discharge thickness (Ha) during operation of the mill train (2) according to the first pass sequence and during operation according to the second pass sequence, and wherein, while the method is being carried out, an automatic gauge control means is switched off temporarily for a respective rolling stand (4, 5, 6, 7) of the mill train (2).
2. Method according to Claim 1,
   characterized in that the method is carried out chronologically after a transition performed during the rolling of rolling stock (G) in the mill train (2) from a first discharge thickness (Ha) of the mill train to a second discharge thickness (Ha) different from the first of the mill train (2).
3. Method according to either of the preceding claims,
   characterized in that the mill train (2) and at least one unit (3) which is arranged upstream of the mill train (2) in the direction of mass flow are coupled in terms of fabrication technology by the rolling stock (G).
4. Open-loop and/or closed-loop control device (8) for a rolling mill (1) which comprises a multi-stand mill train (2), having a machine-readable program code (10) which has control commands which, when executed, cause the open-loop and/or closed-loop control device (8) to implement a method according to one of Claims 1 to 3.
5. Machine-readable program code (10) for an open-loop and/or closed-loop control device (8) for a rolling mill (1), wherein the program code has control commands which cause the open-loop and/or closed-loop control device (8) to implement the method according to one of Claims 1 to 3.
6. Storage medium (9) having a machine-readable program code (10) stored thereupon in accordance with Claim 5.
7. Rolling mill (1) having a multi-stand mill train (2) for rolling, in particular metallic, rolling stock (G), having an open-loop and/or closed-loop control device (8) according to Claim 4, having a device for feeding the discharge rate (Va) of the rolling stock (G) of a unit (3), which is arranged upstream of the mill train (2) in the direction of mass flow, to the open-loop and/or closed-loop control device (8) according to Claim 4, wherein the rolling stands (4, 5, 6, 7) of the mill train (2) are operatively connected to the open-loop and/or closed-loop control device (8).
8. Rolling mill according to Claim 7,
   characterized in that the mill train (2) is embodied as a high reduction mill, which is arranged downstream of a casting unit (3) in the direction of mass flow, and/or a finishing train.
9. Rolling mill according to Claim 7 or 8,
   characterized in that the unit (3) which is arranged upstream is a casting unit (3) which is embodied as a two-roller casting machine (3') or as an ingot mould.

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