WO2022242933A1

WO2022242933A1 - Cassette for at least one working roller in a roll stand

Info

Publication number: WO2022242933A1
Application number: PCT/EP2022/057590
Authority: WO
Inventors: Hartmut Pawelski; Holger Pulst; Markus SCHELLMANN; Christian WIETZIG
Original assignee: Sms Group Gmbh
Priority date: 2021-05-20
Filing date: 2022-03-23
Publication date: 2022-11-24
Also published as: DE102021205156A1; EP4341013A1; JP2024519047A

Abstract

The invention relates to a cassette (100) for at least one working roller (10) in a roll stand (50) for rolling material to be rolled, in particular a metal strip, comprising; a cassette main body (110) with an elongated recess (122) bordered by two opposing short sides and two opposing long sides, wherein the working roller can be rotatably mounted on the short sides; at least one supporting shell (120); at least one supporting bridge (130) mounted in the cassette main body as a carrier for the supporting shell (120); and at least one adjustment mechanism (140) for the articulated linking of the supporting bridge to one of the long sides of the cassette main body and for adjusting the supporting shell with a horizontal adjusting force against the surface of the working roller. According to the invention, in order to effectively prevent a horizontal deflection of the slimline working rollers even in the presence of high rolling forces, the flexural rigidity of the supporting bridge (130) is greater than the flexural rigidity of the adjustment mechanism (140) in combination with the long side of the cassette main body (110) receiving the adjustment mechanism.

Description

Cassette for at least one work roll in a roll stand

The invention relates to a cassette for at least one work roll in a roll stand for rolling rolled stock. In addition, the invention relates to a roll stand with at least one cassette of this type and a method for adjusting the adjustment cylinders in such a cassette.

The background to the present invention is the physical fact that in conventional roll stands with four or six rolls without horizontal support for the work rolls, the permissible work roll diameter has a lower limit. This restriction is given because only work rolls with a sufficiently large roll diameter do not tend to bend laterally or horizontally, even when loaded with high contact forces.

For the cold rolling of high-strength, thin metal strip, however, work rolls with a large degree of slenderness are required in order to be able to transfer large contact forces to the high-strength, thin metal strip without elastic roll flattening occurring. However, in order to also be able to use thin or slender work rolls in roll stands with four or six rolls and in order to also design these stands suitable for rolling said high-strength thin metal strip, it is known in the prior art to use the work rolls with a high degree of slenderness in the to support said scaffolding horizontally; see, for example, the unpublished German patent application DE 102020203076.6.

This patent application not only discloses the use of hydrostatic support shells for the work roll, but also a combination of the small work roll and a first intermediate roll in the form of a cassette for insertion between the roll stands of a roll stand instead of the classic chocks with the normal work rolls otherwise used.

page 1 The supporting shell known from said German patent application is relatively thin and slender; Therefore, even if it is pressed horizontally against the work rolls with an operator-side and a drive-side adjusting cylinder, it is often not suitable for successfully counteracting or even counteracting a horizontal deflection of the work roll or a self-reinforcing deflection of the work roll as a reaction to a large rolling force to prevent such a deflection. The invention is based on the object of further developing a known cassette for at least one work roll in a roll stand, a known roll stand with the cassette and a known method for adjusting the adjustment cylinders in the cassette such that a horizontal deflection of the slim work roll is effective even with high rolling forces is prevented.

This object is solved by the subject matter of patent claim 1 with regard to the cassette. Accordingly, the flexural rigidity of the supporting bridge is greater than the flexural rigidity of the locking mechanism in connection with the left side of the cassette base body that accommodates the locking mechanism

In other words, the invention proposes designing the supporting shell or the supporting bridge carrying it so stiff that it does not yield to large horizontal forces exerted on it by the work roll or does not bend itself or bends only very slightly, even if the support shell or the support bridge is supported on one longitudinal side of the cassette with two adjustment mechanisms which are at a greater distance from one another. Due to the high stressed flexural rigidity of the supporting bridge as a support for the supporting shell, deflection of the supporting shell is prevented even under the influence of large horizontal forces from the work roll, even if the two adjustment mechanisms that carry the supporting bridge with the supporting shell are eccentrically far apart from each other.

Page 2 The decisive feature to be able to build the entire support mechanism into a cassette is the transfer of rigidity to the support bridge. The flexibility of the employment is consciously accepted and sufficiently compensated by a suitable control strategy, see below.

According to a first exemplary embodiment, the adjusting mechanism has at least one adjusting cylinder for adjusting the supporting bridge with the supporting shell against the work roll.

According to a second exemplary embodiment, at least one toggle lever is provided for articulating the supporting bridge with the supporting shell on one of the longitudinal sides of the cassette base body. This takes place via a first lever arm of the toggle lever, which is articulated with its end remote from the knee joint to the longitudinal side of the cassette base body. The second lever arm of the toggle lever is formed by the support bridge itself. Both lever arms are articulated to each other via a knee joint. To realize the operative connection with the toggle lever, the adjusting cylinder is articulated either on one of the two lever arms or on the toggle joint of the toggle lever and is supported with its other end on the longitudinal side of the cassette base body. For this purpose, the adjusting cylinder is preferably articulated vertically, or at least with a vertical component in the longitudinal side of the cassette base body. In this constellation, the adjusting mechanism is formed by the knee joint, the first lever arm and the adjusting cylinder. The second lever arm of the knee joint in the form of the support bridge is no longer part of the adjustment mechanism, because it serves to articulate the support bridge to the longitudinal side of the cassette body and to position it against the surface of the work roll. The formation of the adjusting mechanism 140 'in the form of the toggle lever in connection with the at least substantially vertically employed adjusting cylinder offers the advantage that the cassette in their

page 3 lateral dimensions can be kept slim, in particular so slim that it can be pushed into the stand window of the roll stand instead of the chocks of classic work rolls. According to further exemplary embodiments, position sensors and/or force sensors are assigned to or integrated in the adjusting cylinders. The position sensors are used for direct or indirect detection of the respective contact position of the bearing shell against the work roll. The force sensors are used to record the contact forces with which the supporting shell is typically pressed against the work roll via a film of cooling lubricant.

According to a further exemplary embodiment, a supporting bridge with a supporting shell is articulated on each of the two opposite longitudinal sides of the cassette body so that the supporting shells act on opposite areas of the surface of the work roll. The two supporting bridges are articulated on the opposite longitudinal sides of the cassette base body via preferably two of the said adjustment mechanisms. According to a further exemplary embodiment, an intermediate or back-up roll is also rotatably mounted above or below the work roll on the opposite short sides of the recess in the cassette base body. The intermediate or back-up roll in the cassette is used to vertically support the work roll. The support bridge and the support shell can be formed in one piece. The cassette can be designed as an interchangeable cassette for a roll stand to be pushed into or pulled out of the receptacle for the chocks of the conventional work rolls with a larger diameter in the roll stands of the roll stand. With regard to the roll stand, the above-mentioned object of the invention is achieved by the subject matter of claim 11. Accordingly, the inventive

page 4 Rolling stand characterized by at least one cassette according to one of the preceding claims, wherein the work roll is rotatably mounted on the short sides of the cassette base body. The cassette according to the invention can either be permanently installed in the roll stand between the two roll stands or it is designed as an interchangeable cassette for insertion into or removal from the receptacles for the chocks of the work rolls in the roll stand stands. An upper cassette can be provided in the roll stand for receiving the upper work roll and preferably also an upper intermediate roll and/or a lower cassette can be provided for receiving the lower work roll and preferably also a lower intermediate roll of the roll stand. Otherwise the advantages of the solution for the roll stand correspond to the advantages mentioned above with reference to the cassette.

With regard to the method according to the invention, the above-mentioned object is achieved by the method claimed in claim 15. The method according to the invention relates to the adjustment of the adjusting cylinders in at least one cassette according to one of claims 1 to 10 installed in a roll stand 50 according to one of the preceding claims 11 to 14. The method according to the invention provides as an essential method step that for initialization before the start of rolling operation all Adjusting cylinders in the cassette can be set to a starting target position that is individually specified for each of the adjusting cylinders both on the bending side and on the opposite side by suitably varying the pressure in the adjusting cylinders. In this case, this starting target position corresponds to a

operating point. In this respect, each of the cylinders is set to its respective individual operating point. Based on this working point setting, the target positions of all the adjusting cylinders on the bending side are then changed, in particular increased, until the adjusting forces individually applied by the adjusting cylinders on the bending side each reach a predetermined target

page 5 Preload force should have reached Fv. This target prestressing force is preferably specified uniformly for all adjusting cylinders on the bending side. The target positions for the adjusting cylinders on the opposite side of the bending side within the cassette remain unaffected.

With the method steps described so far, all adjusting cylinders within the cassette are thus set to their respective intended position before the start of the rolling process. During the rolling operation, the differential force of contact forces from contact cylinders arranged in pairs opposite one another within the cassette on the bending side and the opposite side is determined and regulated to a specified expected value for the differential force by suitable variation of the target position for at least one of the opposing contact cylinders involved. In this way, the stability of the rolling process is continuously monitored and maintained.

Furthermore, it is possible to change the roll gap during the rolling process, to set an inclined position of the upper and lower work rolls relative to one another and/or to change the profile of the roll gap, all by suitably controlling the adjusting cylinders in the cassette.

Otherwise, the advantages of this method according to the invention correspond to the advantages mentioned above in relation to the cassette.

The description is accompanied by seven figures, where

FIG. 1 shows a roll stand with the cassette according to the invention

two variants, each in a cross-section;

FIG. 2 shows the cassette according to the invention in a perspective view;

page 6 FIG. 3 shows the cassette according to the invention in a longitudinal section;

FIG. 4 shows the cassette according to the invention in a cross section;

FIG. 5 shows the adjustment mechanism according to the invention with the support bridge according to the invention as a support for the support shell on both sides of the work roll, once in the unloaded state and once in the state with a horizontal load;

FIG. 6 shows a position control circuit according to the invention; and

FIG. 7 shows a target value calculation device with a process model for the technical forming mapping of the rolling process for calculating various position and force target values.

The invention is described in detail below with reference to the figures mentioned in the form of exemplary embodiments. The same technical elements are denoted by the same reference symbols in all figures.

FIG. 1 shows the schematic representation of a roll stand in the form of the plurality of rolls arranged one above the other in the vertical direction. The work rolls 10 each span a roll gap for rolling rolling stock (not shown in FIG. 1), in particular metal strip. In the roll stand 50 shown in the left-hand image of FIG. 1, the upper work roll 10 is supported in the horizontal direction by support shells 120. The support shells 120 are mounted on rigid supports, so-called support bridges 130, and are pressed against the surface of the upper work roll 10

page 7 pressed. The upper work roll 10 is supported by an upper intermediate roll 20 in the vertical direction. The upper intermediate roll 20, the upper work roll 10, the support shells 120 with the support bridges 130 and the adjusting cylinders 142 are mounted in a compact design in an upper cassette 100-o.

The support shells 120 do not press directly on the surface of the upper work roll 10, in particular with their longitudinal sides, but only indirectly via a film of cooling lubricant, for example hydraulic oil. This meaning is also meant when it is casually mentioned in the application that one of the supporting shells presses or is pressed against the work roll. The cooling lubricant is fed into the lubricating gap between the work roll and the supporting shell through the oil lines 170 shown in FIG. 1, which are also connected to an oil pump P. In order to prevent cooling lubricant from escaping from the gap between one of the supporting shells and the work roll on the end faces of the supporting shells 120, screens, e.g. in the form of metal sheets, can be mounted on the two end faces of the respective supporting shell. The screens are preferably formed complementary to the surface of the work roll at their edge sections facing the work roll. The diaphragms can then lie directly on the surface of the work roll outside of the rolling stock to be rolled, in particular during the rolling operation, with their preferably complementary shaped edge sections, preferably via sealing lips, in order to effectively prevent cooling lubricant from escaping.

While the figure on the left in Figure 1 shows the use of the cassette 100-o with the horizontal support only for the upper work roll, the figure on the right of Figure 1 shows that a lower cassette 100-u of similar construction is also used for the horizontal support of the lower work roll 10 can serve. Equally, of course, is the use of said cassette alone

page 8 theoretically possible to support a lower work roll, although not shown in FIG.

FIG. 2 shows the cassette 100 known from FIG of the cassette 100 spoken. It can be seen in FIG. 2 that the cassette 100 consists essentially of a cassette base body 110 in which an elongated recess 112 is formed. The elongated recess 112 is spanned by two opposite short sides and two opposite long sides. The intermediate roller 20 that can be seen in FIG. 2 is rotatably mounted on the opposite short sides. With regard to its external dimensions and in particular with regard to the geometric shape of its end faces on the short sides, the cassette 100 is shaped in such a way that it can be pushed into the receptacles for work roll chocks in the window of a roll stand.

FIG. 3 shows the cassette 100 known from FIG. 2 in a longitudinal section. It can be seen that not only the intermediate roll 20, but also the work roll 10, which is supported by the back-up roll 20 in the vertical direction, is rotatably mounted on the short sides of the recess 112.

FIG. 4 shows said cassette 100 in a cross section, similar to that in FIG. 1, but here in somewhat more detail. It can be seen that the centers or axes of rotation of the work roll 10 and the back-up roll 20 are exactly one above the other. In this constellation there is an unstable or only quasi-unstable equilibrium and the work roll 10 therefore tends slightly to horizontal bending, in particular if the vertical rolling forces occurring are particularly large and its slenderness is large in comparison to that of the intermediate roll 20 . In order to prevent such a deflection of the work roll 10, this is laterally with the help of the support shells 120 in a horizontal

page 9 supported direction. The support shells 120 are in turn each connected to a carrier 130 which, via a positioning mechanism, together with the connected support shell 120, is positioned in the horizontal direction against the surface of the work roll. In the exemplary embodiment according to FIG The ends of the second lever arm 145, 130 near the knee joint are both articulated to one another via the knee joint 144. The end of the first lever arm 145 remote from the knee joint is articulated to the longitudinal side of the cassette base body 110 . The adjusting cylinder 142 is built into the longitudinal side of the cassette base body or is articulated to the longitudinal side, but is at least supported on one side thereof. The other end of the adjusting cylinder 142 is in operative connection with the toggle lever 143, ultimately for adjusting the supporting shell 120 against the surface of the work roll 10. The essentially vertical movement of the adjusting cylinder 142 is converted into a horizontal movement or Contact force deflected for the bearing shell. In order to realize said operative connection between the toggle lever and the adjusting cylinder, the adjusting cylinder 142 can in principle act in an articulated manner both on one of the two lever arms 145 , 130 and on the toggle joint 144 . In the present case, however, the articulation of the adjusting cylinder 142 directly on the knee joint 144, as shown in FIG. 4, appears to be particularly advantageous. The position sensor 150, si with 1<i<I with I€N is used for direct detection of the position of the adjusting cylinder 142 and thus for indirect detection of the adjusting position of the support shell against the work roll. The force sensor 160 is used to directly detect the pressing force of the adjusting cylinder 142 against the toggle lever 143 and thus also to indirectly detect the adjusting force with which the supporting shell is pressed against the work roll 10 . The conversion of the position of the adjusting cylinder into the position

Page 10 of the supporting shell is carried out with the help of generally known conversion formulas from mechanics/kinematics based on the toggle lever 143 used here. The same applies to the conversion of the force. The formation of the adjusting mechanism with the toggle lever 143 shown here is by no means mandatory; on the contrary, in principle other constructive solutions are also conceivable and suitable for the horizontal adjustment of the supporting shells.

The support shells 120 are typically attached to the support bridges; however, they can also be designed in one piece with them. According to the invention, it is of central importance that the supporting bridges 130 have a flexural rigidity that is greater than the flexural rigidity of the adjustment mechanism 140 in connection with the longitudinal sides of the cassette base body that receive or support the adjustment mechanism. In other words, the support bridge as such must be so rigid that it does not yield to deflection of the work rolls in the horizontal direction, i. H. also under

Stress from the horizontal forces on the work roll in particular does not bend itself. The necessary forces for holding the supporting shell with the supporting bridge against the working roll tending to deflect must be absorbed by the toggle lever 143 and the adjusting cylinders as well as the longitudinal side of the cassette body that accommodates or supports them.

FIG. 5 shows a horizontal section through the cassette 100 installed in a roll stand. It can be seen that the support shell with the support bridge 130 preferably extends over the entire length of the work roll 10, but at least over a large part of its length. Furthermore, it can be seen that preferably two adjustment mechanisms per supporting bridge and supporting shell, i. H. there are four screwdown mechanisms per cassette to horizontally screw down the support bridges 130 and support shells against the work roll 10. In the simplest case, the adjustment mechanisms could also only be in the form of an adjustment cylinder 143 - without a toggle lever - which moves the support bridge 130 with support against the longitudinal side of the

page 11 Cassette body in the horizontal direction against the work roll 10 presses, as shown in Figure 5. However, this structural design has the disadvantage that it is comparatively wide, ie it takes up a lot of space in the width direction. In particular, therefore, the configuration according to the embodiment shown in Figure 4 is to be preferred instead, in which the

Adjusting cylinder does not extend in the horizontal direction, but is installed vertically and then presses on the support bridge 130 via the toggle lever 143 shown. 4 has the advantage over the embodiment shown in FIG. 5 that it is more compact in the width direction and allows the cassette to be inserted into the receptacles of the very narrow stand windows of a roll stand.

FIG. 5 also shows the terms “drive side” and “operating side”. The drive side designates the side on which a drive for the work roll is typically provided and the operating side designates the side without a drive from where a roll change typically takes place. The illustration on the left in FIG. 5 shows the cassette or the roll stand 50 in an unloaded state, i. that is, in a state where no horizontal forces in particular are applied to the work roll. In contrast, the right-hand image in FIG. 5 shows the horizontal load condition. The rolling force, which originally acts vertically, causes the intermediate roll 20 and the work roll 10 to be mounted slightly asymmetrically vertically, especially when the

Depending on the slenderness of the work roll 10, there is sometimes a horizontal force which causes the work roll 10 to deflect horizontally, as shown in the right-hand illustration in FIG. In order to prevent precisely this horizontal deflection, the invention provides for the support bridge 130, as mentioned, to be designed with a greater flexural rigidity than the flexural rigidity of the at least one adjustment mechanism in connection with the longitudinal side of the cassette base body 110 that accommodates the adjustment mechanism.

page 12 The method according to the invention for adjusting the adjusting cylinders 142 in the cassette 100 is described below:

It starts with the following steps before the rolling operation: determining the bending side as the longitudinal side of the cassette base body 110 towards which a horizontal bending of the work roll 10 is expected and regulating all adjustment cylinders 142 in the cassette 100 both on the bending side and on the opposite side to one individually for each of the adjusting cylinders 142 specified starting setpoint position s1 setpoint ... s4 setpoint by suitably varying the pressure in the adjusting cylinders. This setting corresponds to a kind of operating point setting. A corresponding control loop is shown schematically in FIG.

Also before the start of the rolling operation, the target positions of all adjustment cylinders 142 on the bending side are changed, in particular increased, typically starting from the initial target positions, until the adjustment forces individually applied by the adjustment cylinders 142 on the bending side 120 each have reached a specified target prestressing force Fv, preferably uniformly for all adjusting cylinders on the bending side.

During the rolling operation, the difference in the contact forces F3-F1, F4-F2 of at least one pair of the contact cylinders arranged opposite one another on the opposite supporting shells is first determined. The difference is then regulated to a predetermined expected value for the differential force by suitably varying the desired positions of at least one of the opposing adjusting cylinders S3, S1 involved; S4,S2. The adjusting mechanism 140, which is designed to be less rigid than in the prior art, is at least partially compensated for by this regulation.

page 13 The previously mentioned initial target position values for the adjusting cylinders s1 set ... s4 set, the set value for the preload force Fv and/or the set values of the expected value for the differential force AF are calculated using a process model based on at least one of the following input variables: a predicted rolling force, a predicted rolling moment, predicted strip tensions on the rolling stock to be rolled by the roll stand, the geometry of the bearing shell 120, the state of wear of the bearing shell, the roll diameter, the desired value for the fluid pressure p between the bearing shell 120 and the work roll; see figure 7.

Some special operating modes for the roll stand are described below, it being assumed that both an upper and a lower cassette 100-o, 100-u according to the invention are installed in the roll stand. Each of the two cassettes is equipped with an operator-side and a drive-side adjusting cylinder 142 on the bending side and the non-bending side, respectively. At least the adjusting cylinders 142 on the non-bending sides are set to their original desired starting position s1 desired - s4 desired as working points. In order to increase or decrease the roll gap created by the work rolls 20, the target positions of all four adjusting cylinders 142 on the non-bending sides of the two cassettes 100-o, 100-u are preferably the same as their starting target positions increased or decreased. During rolling, this results in a respectively desired reduction in thickness of the rolling stock.

In order to achieve an inclined position of the upper and lower work rolls relative to one another, the target positions of the operator-side adjusting cylinders 142 of the upper and lower cassettes - each on the non-bending side - relative to the target positions of the drive-side adjusting cylinders 142 of the upper and lower cassettes - also in each case on the non-bending side - changed. For example

page 14 the target positions of the two adjustment cylinders on the operating side of the upper and lower cassette - each on the non-bending side - are changed by +As. Preferably, the target positions of the two drive-side adjusting cylinders 142 of the upper and lower cassettes are then changed by −As—each on the non-bending side.

To implement a change in the profile of the roll gap spanned by the work rolls, the target positions of the operator-side adjusting cylinder of the upper cassette and the drive-side adjusting cylinder of the lower cassette are each on the non-bending side compared to their starting target positions by one, preferably the same Amount increased or decreased. On the other hand, the target positions of the drive-side adjusting cylinder of the upper cassette and the operator-side adjusting cylinder of the lower cassette are each lowered or increased by the same amount on the non-bending side compared to their starting target positions.

The change amounts As mentioned are manipulated variables that can be specified by thickness or flatness control systems, for example in combination with strip thickness measuring devices or flatness measuring rollers. The advantage is the more direct penetration in the greater vicinity of the metal strip compared to the main position, which is associated with a larger hysteresis.

page 15 Reference List

10 work roll 20 backup or intermediate roll

50 Roll Stand 100 Cassette 100-O Upper Cassette

100-u lower cassette 110 cassette body 112 elongated recess in the cassette body 120 support shell 130 support bridge = second flexible arm 140 adjustment mechanism 142 adjustment cylinder

143 toggle levers

144 knee joint

145 first flail arm 150 position sensor 160 force sensor 170 oil lines

F Contact force on the work roll (=rolling force)

F, Fi Target contact force of the supporting shell against the work roll Target Fv Target preload force

P Target fluid pressure si Target position of the bearing frame

P pump

page 16

Claims

Patent Claims:

1 . Cassette (100) for at least one work roll (10) in a roll stand (50) for rolling rolling stock, in particular metal strip, comprising: a cassette base body (110) with an elongated recess (112) which is spanned by two opposite short sides and two opposite long sides is, wherein the work roll can be rotatably mounted on the short sides; at least one support shell (120); at least one support bridge (130) mounted in the cassette base body as a carrier for the support shell (120); and at least one screw down mechanism (140) for pivotally connecting the support bridge to one of the longitudinal sides of the cassette body and for screwing down the support shell with a horizontal down force against the surface of the work roll; characterized in that the flexural rigidity of the support bridge (130) is greater than the flexural rigidity of the adjustment mechanism (140) in connection with the longitudinal side of the cassette base body (110) receiving the adjustment mechanism.

2. Cassette (100) according to claim 1, characterized in that the adjusting mechanism (140) has at least one adjusting cylinder (142) for adjusting the support bridge (130) with the supporting shell (120) against the work roll (10).

3. Cassette (100) according to claim 2, characterized in that at least one toggle lever (143) is provided which has a toggle joint (144) and a first and a second lever arm (130).

page 17 both are connected to one another in an articulated manner with their ends near the knee joint via the knee joint; and that the first lever arm (145) is articulated with its end remote from the knee joint to the longitudinal side of the cassette base body (110); that the second lever arm is formed by the support bridge (130); and that the adjusting cylinder (142) is built into the longitudinal side of the cassette base body (110) or is articulated to the longitudinal side and is in operative connection with the toggle lever (143) for adjusting the supporting bridge (130) with the supporting shell (120) against the working roll (10 ); and wherein the adjusting mechanism (140) is formed by the knee joint (144), the first lever arm (145) and the adjusting cylinder (142).

4. Cassette (100) according to one of the preceding claims, characterized in that a plurality of, preferably two, adjusting mechanisms (140) are provided along the longitudinal extension of the support bridge (130) for connecting the support bridge to the longitudinal side of the cassette base body (110).

5. Cassette (100) according to one of the preceding claims, characterized by at least one position sensor (150, s), for example integrated in the adjusting cylinder (142), for directly or indirectly detecting the respective adjusting position of the supporting shell (120) against the working roll (10 ).

6. Cassette (100) according to one of the preceding claims, characterized by at least one force sensor (160, F) for detecting the contact force with which the support shell (120) is pressed against the work roll (10).

page 18

7. Cassette (100) according to one of the preceding claims, characterized in that a support bridge (130) with a support shell (120) is articulated on each of the two opposite longitudinal sides of the cassette base body (110) via preferably two of the adjustment mechanisms (140). for pressing the supporting shells onto opposite areas of the surface of the work roll (10).

8. Cassette (100) according to one of the preceding claims, characterized by an intermediate or support roller (20) which can also be rotatably mounted above or below the work roller (10) on the opposite short sides of the recess (112) for supporting the work roller ( 10).

9. Cassette (100) according to one of the preceding claims, characterized in that the at least one support bridge (130) and the at least one support shell (120) are each formed in one piece.

10. Cassette (100) according to one of the preceding claims, characterized in that the cassette (100) is designed as an interchangeable cassette for a roll stand (50) for pushing into or for pulling out of the receptacles for the chocks of the work rolls in the roll stand stands of the roll stand.

11. roll stand (50) having a roll stand on the operator side and a roll stand on the drive side (10); and at least one work roll (10) carried by the roll stands, characterized by

page 19 at least one cassette (100) according to any one of the preceding claims; wherein the work roll is rotatably mounted on the short sides of the cassette body (110).

12. Rolling mill (50) according to claim 11, characterized by an intermediate roll (20) for supporting the work roll, wherein the intermediate roll is also rotatably mounted on the short sides of the cassette base body (110) above or below the work roll.

13. roll stand (50) according to claim 11 or 12, characterized in that the cassette (100) is firmly installed between the two roll stands in the roll stand; or that the cassette (100) is designed as an interchangeable cassette for pushing into or for pulling out of the receptacles for the chocks of the work rolls in the roll stand stands.

14. Rolling mill (50) according to any one of claims 11 to 13, characterized in that an upper cassette (100-o) is provided for receiving the upper work roll (10) and preferably the upper intermediate roll (20) of the rolling mill; and/or that a lower cassette (100-u) is provided for receiving the lower work roll (10) and preferably the lower intermediate roll (20) of the roll stand (50).

15. Method for adjusting the adjusting cylinder (142) in at least one cassette (100) according to one of claims 1 to 10, installed in a roll stand (50) according to one of the preceding claims 11 to 14,

page 20 characterized by the following steps:

Before starting the rolling operation:

Determining the bending side as that longitudinal side of the cassette base (110) towards which a horizontal bending of the work roll (10) is expected;

Adjusting all adjusting cylinders (142) in the cassette (100) both on the bending side and on the opposite side to a starting target position (s1 target ... s4 target) specified individually for each of the positioning cylinders (142) by suitable variation the pressure in the adjusting cylinders.

16. The method according to claim 15, characterized in that the target positions of all adjustment cylinders (142) on the bending side - typically starting from the initial target positions - are changed, in particular increased, until the respective adjustment cylinders (142) individually applied contact forces against the work roll on the bending side (120) have in each case reached a predetermined setpoint prestressing force (Fv)--preferably uniformly for all the adjusting cylinders on the bending side.

17. The method according to claim 15 or 16, characterized by the following steps during the rolling operation, wherein the adjusting cylinders are arranged in pairs opposite one another on the bending side and the opposite non-bending side:

determining the difference in the contact forces (F3-F1, F4-F2) of at least one pair of the contact cylinders arranged opposite one another on the opposite areas of the surface of the work roll; and regulating the difference to a predetermined expected value for the differential force by suitable variation of the target positions of at least

page 21 one of the opposing adjusting cylinders involved (S3, S1; S4, S2).

18. The method according to any one of claims 15 to 17, characterized by a process model for calculating the initial setpoint position values for the adjusting cylinder (s1 setpoint ... s4 setpoint), the setpoint for the preload force (Fv) and/or the expected value for the Differential force (AF) as output variables based on at least one of the following input variables: a precalculated rolling force, a precalculated rolling torque, precalculated strip tensions on the rolling stock to be rolled by the roll stand, the geometry of the support shell (120), the state of wear of the support shell, the roll diameter of the work roll , the setpoint for the fluid pressure p between the bearing shell (120) and the work roll.

19. The method according to any one of claims 15 to 18, characterized in that the target positions of all adjusting cylinders (142) of the upper and the lower cassette 100-o, 100-u on the non-bending side, for example, compared to their initial target positions be increased or decreased by a preferably equal amount in order to realize an enlargement or a reduction of the roll gap spanned by the work rolls (20).

20. The method according to any one of claims 15 to 19, wherein the upper and lower cassette (100) are each present and equipped with an operator-side and a drive-side adjustment cylinder (142) at least on the non-bending side, characterized in that the target positions the adjustment cylinder (142) on the operating side of the upper and lower cassette - each on the non-bending side - relative to the target

page 22 Positions of the drive-side adjusting cylinders (142) of the upper and lower cassette - each on the non-bending side - can be changed, preferably for all adjusting cylinders (142) starting from their initial target positions, in order to achieve an inclined position of the upper and lower work rolls relative to one another .

21. The method according to any one of claims 15 to 20, characterized in that if the method is carried out with both cassettes, the adjustment cylinders of the upper cassette and the lower cassette are preferably each moved by the same amounts with the same sign.

22. The method according to any one of claims 15 to 21, wherein there is an upper and a lower cassette each with an operator-side and a drive-side adjustment cylinder on the bending side and the non-bending side, characterized in that the target positions of the operator-side adjustment cylinder of the upper Cassette and the drive-side adjusting cylinder of the lower cassette are each increased or lowered on the non-bending side compared to their starting target positions by a preferably equal amount; and that the target positions of the drive-side adjustment cylinder of the upper cassette and of the operator-side adjustment cylinder of the lower cassette are each lowered or increased on the non-bending side by preferably the same amount compared to their initial target positions in order to implement a change in the profile of the work rolls.

page 23