Roll stand and method for operating same

Abstract

The invention relates to a roll stand (10) for rolling a rolling stock, comprising: a roll stand frame (3) on the drive side and a roll stand frame (3) on the operating side, wherein, in the two roll stand frames, the necks of working rollers (1) are rotatably mounted in inserts; adjusting devices (4) in the two roll stand frames for applying rolling forces via the inserts onto the working rollers of the roll stand (10); at least one sensor (6) which is associated with one of the two roll stand frames (3) for generating a measurement signal; and an evaluation device (8) for evaluating the measurement signal with regard to the rolling forces exerted on the working roller by the adjusting devices (4). In order to protect the sensor better from dirt and corrosion and, as a result, to achieve more precise measurement signals and control results, the roll stand according to the invention is designed such that at least one hole (7) is made in at least one support post of at least one of the roll stand frames (3), the sensor (6) is introduced into the hole (7) and is designed to detect a deformation of the hole (7) when rolling force is exerted and to generate the measurement signal such that it represents the detected deformation of the hole (7).

Description

[0001] Rolling stand and method for its operation

[0002] The invention relates to a rolling stand for rolling a rolled product and a method for operating the rolling stand. In particular, the invention relates to the measurement of rolling forces in a rolling stand.

[0003] Various solutions are known in the prior art for this purpose. For example, international patent application WO 2007 / 147766 A1 discloses a device and method for measuring the rolling force in a rolling stand using an ultrasonic transmitter-receiver arrangement. This arrangement measures a change in length in a post of a rolling stand due to an applied rolling force, and then converts this measured change in length into the desired rolling force.

[0004] Furthermore, the Chinese patent application CN 101695717 A discloses a sensor for measuring rolling force, wherein the sensor is mounted on the outside of a column post of the rolling stand stand and there measures the changes in length of the column post under load, i.e. when a rolling force is applied by the deformation of a coil and then converts the measured change in length into the required rolling force.

[0005] The rolling force is used for a variety of control functions during the operation of the rolling stand and therefore it is desirable to be able to measure the rolling force accurately even under high dynamic conditions.

[0006] However, inaccurate or faulty rolling force measurements often occur in rolling operations. These can be caused by frictional forces, e.g., between the roll stand housings and the chocks for the backup rolls in the roll stand, or by inhomogeneous force introduction into traditional force measuring devices, e.g., due to corroded or deformed surfaces. These inaccurate force measurements then lead to quality problems in the rolled stock or to a destabilization of the rolling process, e.g., in the form of lateral drift of the rolled stock ends.

[0007] In the two patent applications cited above, the sensors are mounted on the outside of the rolling mill stands, leaving them vulnerable to the harsh conditions of a rolling mill environment, such as dirt and dust, etc. This also results in the risk of a certain inaccuracy in the measurement results.

[0008] The invention is based on the object of providing an alternative rolling stand for rolling a rolled product and an alternative method for operating the rolling stand, which enable a more precise measurement of the rolling force.

[0009] This object is achieved with respect to the rolling stand by the subject matter of patent claim 1. Accordingly, the rolling stand according to the invention is characterized in that at least one bore is provided in at least one post of at least one of the rolling stand stands; that the measuring sensor is inserted into the bore and is designed to detect a deformation of the bore upon application of the rolling force and to generate a measurement signal such that it represents the detected deformation of the bore.

[0010] The bore deformation measured by the sensors originally represents a post force in the respective roll stand. However, these post forces are directly proportional to the rolling force exerted on the rolls. The post forces are converted into the actual rolling force using an evaluation device.

[0011] The basic principle is: Each rolling stand has two rolling stand housings: one on the drive side and one on the operator side. Each rolling stand housing typically has two housing posts. The holes according to the invention are drilled into each of the housing posts. This approximately means that the transducer in the holes measures a housing post force, or post force for short. 2 x post force = housing force; 2 x housing force = rolling force of the rolling stand.

[0012] In the bore, the sensor is advantageously protected, particularly against dirt in the vicinity of the rolling stand and against corrosion, so that its measurement signal is not distorted. Rather, the sensor's measurement signal determined in this way according to the invention provides a reliable basis for the evaluation device to calculate the required rolling force.

[0013] According to a first embodiment, the measuring sensor is inserted into the bore under a preload. The preload of the measuring sensors must be large enough that the measuring sensors still rest in the bores even under maximum rolling force. The preload then defines an operating point for the measuring sensor. A deformation of the bore can then be measured in the form of a change in the preload around the said operating point. Depending on the design of the measuring sensor, the change in the preload compared to the operating point can be determined in the form of a change in the force acting on it in the bore or a change in the mechanical stress acting on it in the bore. Alternatively, the change in its preload can also be determined in the form of a change in a compression distance by which the measuring sensor is compressed in the bore compared to its relaxed state or compared to its compression at the operating point.Piezoelectric sensors or strain gauges, for example, are suitable as measuring sensors for installation in the bore under preload.

[0014] Alternatively or additionally, other sensors can also be inserted into the bore without preload. Suitable for this purpose are, for example, inductive displacement sensors, which detect deformation of the bore caused by rolling force by changing the electrical voltage induced in them, or laser-based displacement sensors, which are designed to detect the deformation of the bore under rolling force load by evaluating, for example, time-of-flight differences in the light signals they emit.

[0015] To compare the stand forces acting on the drive side and the operator side of the rolling stand, it is advantageous if at least one bore with at least one measuring sensor is provided in each of the two rolling stand stands, preferably in each of the four posts of the two rolling stand stands. Except for special requirements, it is generally advantageous if the stand forces on the operator side and the drive side are equal in magnitude.

[0016] The term "drive side" refers to the side of a rolling stand where the drives for the rolls are located. The "operating side" is located opposite the drive side in the axial direction of the rolls and is freely accessible to operators, e.g., for roll changes.

[0017] The provision of multiple transducers in a bore offers the advantage of allowing redundant measurements, which also increases the accuracy of the calculated rolling force. The majority of transducers installed in the bore can be based on the same or different physical principles. Installing transducers based on different physical principles would be a further measure to increase measurement accuracy.

[0018] In principle, the deformation of the bore in the roll stand posts can be measured on the operating and drive sides of the roll stand and / or on the entry and exit sides of one of the roll stand stands at any height of the roll stand posts. However, positioning the bores and the measuring transducer located there at the level of the horizontal rolling line offers the advantage that the forces to be measured there are not influenced by frictional forces between the components and the stand posts. The bores should preferably be positioned perpendicular to the rolling line, in a range of 200 mm above to 200 mm below the rolling line.

[0019] The installation of the measuring sensors at the same height on all posts of the rolling stand stands involved increases the comparability of the deformations measured in the individual stands, because the deformations at the same height of the stand posts should be the same or at least similar.

[0020] If the bores for the measuring sensors are each inserted into the uprights of the roll stand in a plane perpendicular to the rolling forces applied by the adjusting devices, i.e. in a horizontal plane, this offers the advantage that the deformation of the bores to be measured also acts at least essentially perpendicularly on the measuring sensors. This advantageously applies regardless of whether the bores are inserted into the uprights of the roll stand in the rolling direction, transverse to the rolling direction, or at any acute angle to the rolling direction. With vertically acting rolling forces, the horizontal alignment of the bores offers the advantage that the deformation of the bores does not act on the measuring sensor at an oblique angle, which advantageously eliminates the need for coordinate transformation of the resulting measurement signals.

[0021] The provision of holes for the measuring sensors in each of the roll stands, on the inlet side in the inlet side post, and on the outlet side in the outlet side post, offers the advantage that the post force of the respective roll stand can be determined by simply adding the two post forces measured by the measuring sensors.

[0022] The post forces determined according to the invention can be used for strip thickness control. For this purpose, the post forces determined on the inlet and outlet sides of the column posts of a roll stand are first summed to form the column force of the roll stand. This is done separately for the roll stand stands on the drive side and the operator side. The drive-side and operator-side column forces determined in this way are added to the rolling force of the roll stand. This rolling force is then converted into the actual thickness for the rolled stock at the exit of the roll stand. The actual thickness determined in this way is then output and preferably controlled to a predetermined target thickness for the rolled stock as part of the strip thickness control by outputting a suitably varied position control signal to the adjusting devices on the drive and operator sides, in particular the respective adjusting cylinders.To more precisely determine the strip thickness control result, an additional stand force measuring device can be provided in each of the two rolling stand housings, for example, below the chocks of the lower support roll of the rolling stand. This device can be used to directly measure the stand forces in the two rolling stand housings. This evaluation device is then designed to calculate the rolling force, also taking into account the additionally measured stand forces.

[0023] In addition, a position control device can be provided for controlling the position control signal output to the adjusting devices to the desired position represented by the position control signal output by the strip thickness control device.

[0024] The above-mentioned advantages of the rolling stand according to the invention also apply equally to the method-based solution of the problem of the invention according to claim 14.

[0025] Further advantageous embodiments of the rolling stand according to the invention and of the method according to the invention for its operation are the subject of the dependent claims.

[0026] Four figures are attached to the description, where

[0027] Figure 1 shows the rolling stand according to the invention and an associated rolling stand stand in individual view with a first embodiment for the alignment of the bores for the measuring sensors;

[0028] Figure 2 shows the rolling stand and the individual rolling stand column analogous to Figure 1, but with a second embodiment for the alignment of the bores according to the invention;

[0029] Figure 3 shows a single rolling stand with a first embodiment of strip thickness control; and

[0030] Figure 4 shows the individual rolling stand according to Figure 3 with an alternative strip thickness control.

[0031] The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. In all figures, identical technical elements are designated by identical reference numerals.

[0032] The right-hand illustration of Figure 1 shows the rolling stand 20 according to the invention for rolling a rolled stock. The rolling stand 20 consists of a rolling stand housing 3 on the drive side (AS) and a rolling stand housing 3 on the operating side (BS), with the two rolling stand housings being connected to each other via crossheads. In the two rolling stand housings 3, the journals of both the backup rolls 2 and the work rolls 1 are rotatably mounted in chocks. The chocks can be seen in the left-hand illustration of Figure 1 and are designated there by the reference numeral 13.

[0033] An adjusting device 4 is shown for applying a stand force via the chocks 13 and the backup rolls 2 to the work rolls 1. The sum of the stand force of the drive-side roll stand and the stand force of the operator-side roll stand is the so-called rolling force of the roll stand. The right-hand illustration of Figure 1 shows the bores 7 according to the invention, into each of which a measuring sensor 6 is inserted. The measuring sensors 6 are each designed to generate a measuring signal which represents a deformation of the bores in the stand posts 3a, 3b of the respective roll stand 3 in accordance with the stand forces or rolling forces applied by the adjusting devices 4.

[0034] As can be seen from the left-hand illustration in Figure 1, the adjusting device 4 acts in a vertical direction. In order to be able to determine the maximum effect of the length changes of the roll stand caused by the rolling force and the associated deformation of the bore 7 with the measuring sensors 6, it is advantageous if the bores are formed in a plane perpendicular to the acting rolling force, i.e., in a horizontal plane, as in the embodiments shown in the figures.

[0035] In the first embodiment shown in Figure 1, the bores 7 are arranged horizontally in this horizontal plane and aligned in the direction of the longitudinal axes of the rolls 1, 2, i.e. transversely to the rolling direction; see right-hand illustration. It can be seen that in each of the two roll stands 3 and also in each of the respective stand posts 3a, 3b of one of the two roll stands, a measuring sensor 6 is arranged in bores; accordingly, in total, there are four measuring sensors 6 in the roll stand shown in Figure 1 for measuring the deformation of the bores into which they are each inserted.

[0036] The measuring sensors 6 shown in Figure 1 are arranged in bores 7, each of which is mounted at the same height, namely at the height of the roll gap spanned by the work rolls 1. This also applies to the special case shown in Figure 1, in which the work rolls, exceptionally, do not span a roll gap; however, the bores 7 and the measuring sensors 6 are arranged here at the height within the roll stand housings at which the two work rolls 1 touch each other. The left-hand illustration shows a single one of the roll stand housings 3; it has an analogous structure for the drive side AS and the operating side BS.

[0037] Figure 2 differs from Figure 1 only in that the bores 7 for the measuring sensors 6 are aligned in the rolling direction. In the second exemplary embodiment for the alignment of the bores 7 shown in Figure 2, it can also be seen that these bores lie in a horizontal plane perpendicular to the acting rolling force, and that the measuring sensors 6 are arranged at the height within the roll stand at which the two work rolls 1 touch.

[0038] Figure 3 shows a first embodiment of the strip thickness control according to the invention for controlling the actual thickness h AC T of the rolling stock to a specified target thickness, in Figure 3 with the reference symbol h RE F. The inventive strip thickness control provides that the post forces F Pfwith the preferably four measuring sensors 6 according to the invention in their associated bores on the inlet side E and the outlet side A of the roll stands 3 on the drive and operating sides AS, BS (the latter not shown). Subsequently, the actual rolling force FWACT is calculated as the sum of these four measured post forces F Pf : F PfA s, F PfB s is calculated using the evaluation device 8. If the post forces F Pf can be measured, these two post forces are added together and the sum is multiplied by 2 in order to calculate the actual rolling force, at least approximately. From the actual rolling force FWACT, the actual rolling force is then calculated - with the help of the conversion device 9, taking into account the actual cylinder positions S AC TAS, S AC TBS at the adjustment devices 4 in the two rolling stand stands 3 on the drive side AS and the operating side BS - the actual thickness h ACT of the rolling stock at the exit of the rolling stand is calculated as follows:

[0039] The current actual strip thickness h AC T in the roll gap is calculated by subtracting the sum of the calibration positions s oAS , s oB s the sum of the cylinder positions S AC TAS, S AC TBS is subtracted from the adjustment devices on the drive side AS and the operator side BS, respectively, and the stand elongation ΔTACT(FWACT). The stand elongation is a function of the rolling force and is determined by inserting the rolling force into a stand model. ΔTACT = (ΔTAS + ΔTBS) / 2 - (ΔTAS + ΔTBS) / 2 - ΔTACT(FWACT) h A cT Actual thickness of the rolled stock

[0040] SACTAS, SACTBS Actual position of the adjusting device on the drive and operating side

[0041] SOAS, SOBS (calibration) position of the adjustment device during calibration with a calibration roller force on the drive and operating side,

[0042] FWACT actual rolling force g A cT actual scaffold strain

[0043] The actual strip thickness control 10 then provides that the said target thickness h RE F with the actual thickness h calculated in the above manner A cT of the rolled stock is continuously compared to calculate the difference between the target and actual thickness of the rolled stock as a control deviation for the thickness of the rolled stock. Based on this control deviation, the strip thickness control device 10 then determines suitable position control signals SREFAS, SREFBS for the adjustment devices 4 of the roll stands 3 on the drive and operating sides.

[0044] In order to precisely ensure the setting of the suitable positions specified by the strip thickness control device 10 for the adjusting device 4, it is advantageous to monitor and ensure the setting of these positions by means of a position control device.

[0045] Finally, Figure 4 shows a second embodiment of the strip thickness control shown in Figure 3. The only difference from the strip thickness control shown in Figure 3 is that in at least one of the roll stand stands, preferably in both the drive-side roll stand stand and the operator-side roll stand stand, an additional stand force measuring device 5 is provided, for example, below the chock 13 of the lower backup roll 2. The evaluation device 8, which is also already required according to Figure 3, is then further designed to calculate the actual rolling force FWACT more precisely, preferably on the drive and operator sides, taking into account the stand forces FstandAS, FstandBS measured by the force measuring devices 5.This can be achieved, for example, by averaging the column forces calculated from the measured post forces with the directly measured column forces FcolumnAS, FcolumnBS on the drive and operator sides for the further calculation of the rolling force. This further refines and specifies the desired thickness control for the rolled stock at the exit of the roll stand.

[0046] The method for operating the rolling stand 10 comprises the following steps: applying a rolling force via the chocks to the work rolls of the rolling stand for rolling the rolled stock, generating a measurement signal, and evaluating the measurement signal with respect to the actual rolling force FWACT exerted on the work rolls. For this purpose, at least one bore 7 is formed in at least one post of the at least one rolling stand 3, and a deformation of the bore 7 upon application of the rolling force is detected using the measuring sensor. The measurement signal represents the detected deformation of the bore 7.

[0047] The sensor 6 can be a piezoelectronic sensor or a strain gauge, which is preferably inserted into the bore with a preload. The deformation of the bore 7 is then recorded in the form of a change in the preload with which the sensor is inserted into the bore. The change in the preload is recorded in the form of a change in the force or stress acting on the sensor in the bore 7 or in the form of a change in the compression distance by which the sensor 6 is compressed in the bore 7 compared to its relaxed state or compared to a compression at an operating point of the sensor. Alternatively, the sensor 6 can be designed as a laser-based displacement sensor and inserted into the bore 7 without preload. The deformation of the bore is then recorded in the form of measured displacement / time differences of light signals emitted by the laser-based displacement sensor in the bore.

[0048] Alternatively, the measuring sensor 6 can be designed as an inductive displacement sensor and inserted into the bore (7) without preload. The deformation of the bore is then detected in the form of electrical voltages induced in the inductive displacement sensor due to the deformation.

[0049] Controlling the actual thickness h ACT of the rolled stock to a specified target thickness h RE F is carried out by issuing a suitably varied position control signal to the adjusting devices, in particular the adjusting cylinders. The actual thickness h ACT of the rolling stock from the actual rolling force F determined by the evaluation device 8 WA CT calculated.

[0050] The positions of the adjusting devices, in particular the position of the adjusting cylinders, are preferably controlled to the target position represented by the position control signal SREF.

[0051] Finally, the strip thickness control can be performed separately for the rolling stand 3 on the operator side and for the rolling stand 3 on the drive side. In this case, it is recommended that the two strip thickness controls 9 be synchronized to the same target thickness for the rolled material.

[0052] List of reference symbols

[0053] 1 work rolls

[0054] 2 support rollers

[0055] 3 rolling mill stands

[0056] 3a, 3b post

[0057] 4 Adjustment device

[0058] 5 Force measuring device

[0059] 6 sensors

[0060] 7 Hole

[0061] 8 Evaluation device

[0062] 9 Conversion device

[0063] 10 Strip thickness control device

[0064] 12 Position control device

[0065] 13 chocks

[0066] 20 rolling stands

[0067] AS drive side of the rolling stand

[0068] BS operating side of the rolling stand

[0069] E Inlet side

[0070] A outlet side h RE F Target thickness h A cT actual thickness

[0071] FWACT actual rolling force

[0072] SACTAS, SACTBS Actual position of the adjusting device, in particular of its adjusting cylinders on the drive or operating side

[0073] SREFAS, SREFBS Target position of the adjusting device, in particular of its adjusting cylinders on the drive or operating side

[0074] F P f post force

[0075] FpfAs Post force on the drive side

[0076] Fpfßs Post force on the operating side

[0077] FständerAs directly measured stator forces on the drive and / or FständerBS operating side

Claims

Patent claims:

1. Rolling stand (20) for rolling a rolled material, comprising: a rolling stand stand (3) on the drive side (AS); and a rolling stand stand (3) on the operator side (BS), wherein the journals of work rolls (1) are rotatably mounted in mounting blocks (13) in the two rolling stand stands; Adjustment devices (4) in the two rolling stand uprights (3) for applying rolling forces via the mounting blocks (13) to the work rolls of the rolling stand (10); at least one measuring sensor (6) assigned to one of the two rolling stand uprights (3) for generating a measurement signal; and an evaluation device (8) for evaluating the measurement signal with regard to the rolling forces exerted on the work roll by the adjustment devices (4); characterized in that at least one bore (7) is provided in at least one upright post (3a, 3b) of at least one of the rolling stand uprights (3); that the measuring sensor (6) is inserted into the bore (7) and is designed to detect the deformation of the bore (7) when the rolling force is applied and to generate the measurement signal such that it represents the detected deformation of the bore (7).

2. Rolling stand (20) according to claim 1, characterized in that the measuring sensor (6) is inserted into the bore (7) under a preload; that the measuring sensor (6) is designed to detect the deformation of the bore (7) in the form of a change in its preload; and that the measuring sensor (6) is designed to detect the change in its preload in the form of a change in the force acting on it in the bore (7). force or mechanical stress or in the form of a change in compression path by which the measuring sensor (6) is compressed in the bore (7) compared to its relaxed state.

3. Rolling stand (20) according to claim 2, characterized in that the measuring transmitter (6) is designed in the form of a piezoelectric sensor or in the form of a strain gauge.

4. Rolling stand (20) according to claim 1, characterized in that the measuring sensor (6) is inserted into the bore (7) without preload; and that the measuring sensor (6) is designed in the form of an inductive or laser-based displacement sensor for detecting the deformation of the bore.

5. Rolling stand (20) according to one of the preceding claims, characterized in that at least one bore (7) is provided in each of the four upright posts (3a, 3b) of the two rolling stand uprights (3); and that at least one measuring sensor (6) is provided in the bores (7) in each of the rolling stand uprights (3).

6. Rolling mill stand (20) according to one of the preceding claims, characterized in that a plurality of measuring sensors (6) is inserted into the at least one bore (7) in the at least one upright post (3a, 3b).

7. Rolling stand (20) according to one of the preceding claims, characterized in that the bores (7) and the measuring sensors (6) are located in the upright posts (3a, 3b) of the two rolling stand uprights (3) on the operating and / or drive side. (BS, AS) of the rolling stand and on the entry and / or exit side (E, A) of one of the rolling stand uprights (3). Rolling stand (20) according to claim 7, characterized in that the bores (7) for the measuring sensors (6) are each located at the same height, preferably at the height of the roll gap opened by the work rolls (1) in the upright posts (3a, 3b). Rolling stand (20) according to one of the preceding claims, characterized in that the bores (7) for the measuring sensors (6) are each provided in a plane perpendicular to the preferably vertical direction of the rolling forces applied by the adjusting devices (4), preferably in the rolling direction or transverse to the rolling direction and / or at any acute angle to the rolling direction in the rolling stand uprights (3).Rolling stand (20) according to one of claims 7 to 9, characterized in that at least one strip thickness control device (10) is provided for controlling the actual thickness of the rolled material to a predetermined target thickness (h. RE F) by outputting a suitably varied position control signal (SREF) to the actuating devices (4), preferably on the drive and on the operator side, in particular to their actuating cylinders; and that a conversion device (9) is provided for calculating the actual thickness (h A cT) of the rolled material from the actual rolling force (FWACT) determined by the evaluation device (8). Rolling stand (20) according to claim 10, characterized in that an additional stator force measuring device (5) is provided for directly measuring the stator force in the rolling stand (20), preferably on the drive and operator sides; and that the evaluation device (8) is designed to calculate the actual rolling force on the rolled material, also taking into account the additionally measured stand forces. Rolling stand (20) according to claim 10 or 11, characterized by a position control device (12) for controlling the position of the adjusting device (4), in particular the position of the adjusting cylinders, to the target position represented by the position control signal output by the strip thickness control device (9), preferably on the drive and operator sides.Rolling stand (20) according to one of claims 10 to 12, characterized in that a strip thickness control device (9) for the rolling stand frame (3) is provided on the operator side (BS) and a further strip thickness control device for the rolling stand frame (3) is provided on the drive side (AS); and that the two strip thickness control devices (9) are synchronized to achieve the same target thickness for the rolled material. Method for operating the rolling stand (10) according to one of the preceding claims, comprising the following steps: applying a rolling force via the mounting blocks (13) to the work rolls (1) of the rolling stand (20) for rolling the rolled material; Generating a measurement signal; and Evaluating the measurement signal with regard to the actual rolling force (FWACT) exerted on the work rolls; characterized in that at least one bore (7) is provided in the upright posts (3a, 3b) of the rolling stand upright (3); that a deformation of the bore (7) is detected when the rolling force is exerted. a method according to claim 14, characterized in that the measuring sensor (6) is a piezoelectronic sensor or a strain gauge, which is preferably inserted into the bore with a preload; that the deformation of the bore (7) is detected in the form of a change in the preload with which the measuring sensor (6) is inserted into the bore; and that the change in preload is detected in the form of a change in the force or stress acting on the measuring sensor in the bore (7) or in the form of a change in a compression stroke by which the measuring sensor (6) is compressed in the bore (7) compared to its relaxed state or compared to an operating point of the measuring sensor (6) for the force, stress or compression stroke.A method according to claim 14, characterized in that the measuring sensor (6) is designed as a laser-based displacement sensor and is inserted into the bore (7) without preload; and that the deformation of the bore is detected in the form of measured displacement / time differences of light signals emitted by the laser-based displacement sensor in the bore. A method according to claim 14, characterized in that the measuring sensor (6) is designed as an inductive displacement sensor and is inserted into the bore (7) without preload; and that the deformation of the bore is detected in the form of electrical signals induced in the inductive displacement sensor by the deformation. Tensions.

18. Method according to one of claims 14 to 17, characterized by Rules of actual thickness (IIACT) of the rolled material to a specified target thickness (h RE F) by outputting a suitably varied position control signal (S REF) to the adjusting devices, in particular the adjusting cylinders; and calculating the actual thickness (IIACT) of the rolled material from the actual rolling force (FWACT) determined by the evaluation device (8).

19. Method according to one of claims 14 to 18, characterized in that the actual rolling force (FWACT) is determined from the post forces (F) of the two rolling stand uprights (3) on the operating and / or drive side (BS, AS) of the rolling stand and on the entry and / or exit side (E, A) of one of the rolling stand uprights (3) by the measuring sensors (6) in the upright posts (3a, 3b) of the two rolling stand uprights (3) on the operating and / or drive side (BS, AS) of the rolling stand and on the entry and / or exit side (E, A) of one of the rolling stand uprights (3). Pf ) is determined by summing the actual rolling force when 4 post forces are measured, or by summing the actual rolling force when only 2 post forces are measured and multiplying the sum by 2.

20. Method according to claim 18 or 19, characterized in that the stand force in the rolling stand is additionally measured directly; and that the actual rolling force (FWACT) and the actual thickness (IIACT) of the rolled material are also calculated taking into account the additionally measured stand force.

21. Rolling mill process (10) according to claim 18, 19 or 20, characterized by Rules regarding the position of the positioning devices (4), in particular the position the actuating cylinder to the target position represented by the position control signal (SREF). Method according to one of claims 18 to 21, characterized in that the strip thickness control for the rolling stand (3) is carried out on the operator side and for the rolling stand (3) on the drive side; and that the two strip thickness controls (9) are synchronized to the same target thickness for the rolled material.

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