Title of Invention

METHOD AND PLANT FOR RESHAPING METAL STRIP IN A HOT STRIP ROLLING MILL

Abstract

A method and an installation for shaping metal strip in a hot strip rolling mill which includes a finishing train, a cooling stretch, a driver, and a reeling plant, wherein, after emerging from a cooling zone, the strip material is alternatingly conducted over and under at least two successively arranged stretcher-leveller work rolls which form a stretcher-leveller zone, and wherein the stretcher-leveller work rolls are arranged offset relative to each other in such a way that the metal strip is deflected at each stretcher-leveller work roll.

Full Text

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a plant for reshaping metal strip in a hot strip rolling mill which includes a finishing train, a cooling stretch, a driver, and a reeling plant. 2. Description of the Related Art It is known in the art to roll metal after the casting process in a hot strip rolling mill until it reaches a certain thickness in order then to convey the resulting product after a reeling procedure to a cold strip rolling mill for rolling the product to the final dimension. In this connection, increasingly higher demands are made of the metal strip supplied to the cold strip rolling mill with respect to its mechanical and geometric properties, particularly its planarity. Simultaneously, there is the tendency that the desired final properties of the metal strip, which result from the successively arranged processes of the hot and cold rolling mills, is already adjusted in the hot rolling process or that a hot strip is produced which meets optimum requirements for the subsequent hot rolling process. Simultaneously, the boundary conditions become more difficult during hot rolling. Increasingly thinner and wider products are desired for adjusting them to the final product; this requires a greater thickness reduction and the use of greater rolling forces in the end stands of the hot strip rolling mill train. Consequently, the wear of the rolls increases with the decreasing size of the roll gap. Moreover, the thermal crown of the rolls increases when the production on the rolling train is increased. These effects negatively influence the planarity of the hot strip and, thus, also the quality of the strip in the cold state. A conventional means for producing planar hot strip is the use of adjusting members. However, in the case of extremely thin strips, currently hardly any or no reliable hot strip planarity measurements are available. Moreover, in a hot strip rolling mill, in addition to the deviations from planarity resulting from the finishing train, planarity changes of the metal strip occur in the cooling stretch and are caused by the driver rolls. The strip leaves the finishing train partially with a non¬uniform planarity or stress distribution over the strip width. Even in the case of equal boundary conditions, such as, geometric dimensions, tensions, temperatures, material, etc., this may have the result in strips which are rolled in rapid sequence that different planarities in the cold strip are produced. This uneven planarity distribution of the hot strip then results directly or indirectly in different planarity conditions of the cold strip because of changed coiling conditions at the reel, for example, higher coil crown. Furthermore, the strip planarity changes due to the deflection of the strip at the driver in the direction of the desired reeling plant by the different tensile stress . distribution over the width of the strip. Principal influencing variables in this connection are the ground driver shape, the wear of the driver rolls, the contact pressure as well as the thermal crown of the driver rolls. However, an optimization of the surface of the driver resulting from grinding as well as a change of the driver roll material and the manner of exchanging the driver rolls can improve the boundary conditions. When the strip is coiled into a coil, a non-uniform tensile stress distribution is partially produced over the strip width. In dependence on the tensile stress level, this non-uniform distribution produces different strip elongations over the strip width and, thus, non-planarities for the cold state. In this connection, principal influencing variables are the coil crown which is being adjusted. The shape of the coil depends on the strip contour, the strip planarity during reeling, the material strength (temperature, material quality) and the reel tension. A disadvantage is the fact that it is not possible to directly influence the changes of the planarity at the driver roll as well as at the reel and the changes caused by the cooling of the coil. This produces local non-planarities of the strip. Also, unsteadiness of the immediate strip end has been observed. SUMMARY OF THE INVENTION Therefore, it is the primary object of the present invention to provide a method and an installation for adjusting desired planarity and tension conditions in the hot strip, so that a planar strip is obtained in the cold state. In accordance with the present invention, after emerging from a cooling zone, the strip material is alternatingly conducted over and under at least two successively arranged stretcher-leveller work rolls which form a stretcher-leveller zone, wherein the stretcher-leveller work rolls are arranged offset relative to each other in such a way that the metal strip is deflected at each stretcher-leveller work roll. In accordance with another feature, the function of two stretcher-leveller work rolls can also be assumed solely by the two driver rolls. In that case, the stretcher-leveller zone is provided by adjusting the upper or lower driver roll into the area in front or following the original driver roll position. In contrast to a known arrangement for stretching and bending, as it is disclosed in DE 36 36 707 C2, the present invention proposes to arrange the stretcher-leveller zone at the end of the hot rolling process. The stretcher-leveller zone is formed by additional stretcher-leveller rolls in front of or following the driver rolls or by the driver rolls themselves. In contrast, the German patent mentioned above discloses a stretching and bending arrangement with a subsequently arranged roll stand. By guiding the strip through a stretcher-leveller zone formed in accordance with the present invention, the desired planarity and stress properties can be adjusted in the metal strip even before it is coiled into a coil. By using a higher quality, already planar hot strip, this makes it possible to essentially eliminate negative influences from the preceding processes and to improve the quality of the strip in the cold state. Sufficient for this purpose in the simplest case are already two stretcher-leveller work rolls for forming a stretcher-leveller zone, wherein the metal strip is not rolled between the rolls, but is bent and stretched between the successively arranged rolls. Consequently, it is possible to even out non-planarities and to adjust more uniform stress conditions. The aftertreatment of the strip by means of stretcher-leveller work rolls eliminates the non-planarities resulting from the finishing train, for example, parabolical non-planarities and non-planarities of a higher degree, as well as the non-planarities and stresses which are produced.in the cooling stretch. Moreover, the use of these stretcher-leveller work rolls makes it possible to avoid or reduce disadvantageous damage to the strip end in the form of local non-planarities and unsteadiness of the immediate strip end. The proposed stretcher-leveller work rolls, which are arranged following the driver and in front of the reel, make it possible that, in addition to the non-planarities resulting from the finishing train and the cooling stretch, even the planarity changes at the driver can be eliminated. Moreover, reproducible planarity conditions can be adjusted. In order to prevent damage to the strip surface, the rolls should be driven independently or should have a low moment of inertia. On the other hand, it is also conceivable to produce a hot strip which is already ready for use and has the desired thin final dimensions. The stretcher rolls according to the present invention make it possible to adjust already in the hot strip a sufficient degree of planarity, so that in some cases the cold strip rolling process may be omitted altogether. In accordance with an advantageous feature, the stretcher-leveller zone is formed by three stretcher-leveller work rolls of a first type which are arranged one behind the other. The stretcher-leveller rolls of the first type have a cylindrical shape. In accordance with another advantageous embodiment of the invention, a stretcher-leveller work roll of a second type is used which advantageously is combined with two stretcher-leveller work rolls of the first type. Advantageously, the metal strip travels first through the stretcher-leveller zone formed by the rolls of the first type and then over the roll of the second type. By a specific configuration of the crown of this roll of the second type, it is then possible to then compensate any still existing non-planarities of the metal strip. This configuration makes it possible to produce over the strip width a non-uniform tension distribution, so that the strip can locally be stretched in such a way that it is as planar as. possible in the cold state. Of course, it is also conceivable that the stretcher-leveller unit is composed of only one stretcher-leveller work roll of the first type in combination with two stretcher-leveller work rolls of the second type. This combination may include two successively arranged stretcher-leveller work rolls of the second type and, in front of the two rolls of the second type, a stretcher-leveller work roll of the first type which preferably is cylindrical. This increases the flexibility of the stretcher-leveller zone as a reaction to the different planarities of the strip which depends to a significant extent, as described above, on the finishing stretch and the cooling stretch. By providing a roll of the second type, the cross bow of the strip, which frequently is observed in the cold state, is positively influenced. It is also conceivable that the stretcher-leveller zone is composed of a stretcher-leveller roll or rolls of the second type with a subsequently arranged roll or rolls of the first type. Basically, all combinations with more than two rolls of the one or other type are conceivable. For an optimum adjustment of the position or the contact pressure of this additional stretcher-leveller work roll of the second type, it is possible to utilize the measurement values for the strip contour, the strip temperature distribution, the strip thickness, and the tension level as well as the information concerning the regularities derived from the off-line cold linearity evaluation, etc. This may result in different adjustments of the stretcher-leveller work rolls over the strip length. In accordance with another feature, the work roll of the second type may be composed of two separate roll bodies. This makes it possible to flexibly react to different strip widths or strip non-planarities during the process because the roll can be appropriately adjusted since the roll bodies are mounted so as to be fixed or swinging and displaceable in orientation relative to the strip edge. In accordance with an advantageous feature, the lower driver roll can assume the task of the first stretcher-leveller work roll of the first type. Alternatively, the stretcher-leveller zone can be exclusively formed by the upper and lower driver rolls. This is achieved by laterally downwardly swinging the upper driver roll when the reel has grasped the strip beginning and, thus, the strip has been deflected at the driver rolls. In the embodiment with driver rolls and stretcher-leveller rolls, these rolls usually also do not contact the strip at the strip beginning. The stretcher-leveller rolls are swung into the work position only after tensile stresses have been built up. In accordance with an advantageous feature, a strip zone cooling unit, particularly a water-cooling unit, is provided in the stretcher-leveller zone. This strip zone cooling unit may preferably be constructed as a scale washer. Water is admitted with high pressure to the strip on both sides, which makes it possible to simultaneously remove the tertiary scale. A temperature measuring device is provided following the cooling zone, i.e., in front of the reeling device. It is also recommended that, in addition to the strip, the stretcher-leveller rolls are also cooled to reduce the thermal crown and the wear. Conventional water cooling units can be used for this purpose. It is advantageous to carry out strip zone cooling not only in the stretcher-leveller zone,- but also immediately in front of the reeling unit. Advantageous in this connection is the spraying technology using water or another liquid which serves as a gliding/separating agent. A gliding agent is recommended because the gliding properties of the strip layers relative to each other during cooling of the coil are advantageously influenced. In accordance with a particularly preferred embodiment of the present invention, a stretcher-leveller zone is integrated at the end of a hot rolling process, i.e., even after travelling through the finishing train. In this connection, for adjusting a planar strip, it is proposed that the adjustment of the stretcher-leveller rolls relative to the strip and relative to each other are controlled by means of a first control circuit in dependence on the strip properties which are measured at the same time. Also, the strip tension level, which differs over the strip length, can be controlled. For this purpose, it is possible, for example, that a planarity measuring roller is arranged following the stretcher-leveller zone as seen in strip travel direction. The planarity measuring roller is a segmented tension measuring roller. The values picked up by this measuring roller are used in the form of signals by a control circuit for controlling the stretcher- leveller adjusting members and/or the finishing train adjusting members for further influencing the planarity. It is conceivable that the rolls of the first and second type which form the stretcher-leveller zone are constructed as segmented tension measuring rollers. Finally,, it is proposed in accordance with another advantageous feature that a second control circuit is used for controlling the adjustments of the cooling stretch arranged in front of the stretcher-leveller zone in dependence on the strip properties. The control of the adjusting members of the stretcher-leveller zone are preferably coupled to the control of the adjusting members of the cooling stretch in such a way that both control circuits utilize a common desired value. The actual value and the desired value of these control circuits constitute the strip properties. They are, for example, the temperature distribution over the strip width, the strip contour and/or the • strip tensions. Conventional cooling patterns are used for controlling the cooling stretch. Conceivable are, for example, the adjustment of the cooling device in such a way that a reduced cooling effect occurs in the strip edge region or that an additional cooling effect is achieved in the strip edge region or a parabolic change of the temperature distribution is effected over the strip width. As is well known, the changes of the temperature distribution over the strip width produce non-planarities due to different thermal shrinking." In interaction with the subsequently arranged stretcher-leveller unit and the cooling behavior, these cooling patterns are applied in order to achieve a compensation of these effects and, thus, a more planar strip. Finally, it is conceivable to control by means of an additional control circuit the mechanical adjusting members of the stretcher-leveller work rolls in dependence on the strip properties. In order to be able to increase the tension level in a specified manner in the stretcher-leveller zone, it is additionally proposed to press a stretcher-leveller roll against a roll arranged underneath this stretcher-leveller roll, or to increase the depth of insertion of this roll, i.e, the extent by which the roll deflects the strip. Alternatively, an additional driver can be arranged in front of the stretcher-leveller zone as seen in the strip travel direction. Accordingly, the present invention relates to method of reshaping metal strip in a hot strip rolling mill, wherein the rolling strip after running through a finishing train and a cooling path is fed by way of a driver, which consists of an upper and a lower driver roller, to a coiling device, wherein the metal strip in a region between the end of the cooling path and the coiling device is led in alternation above and below at least two stretch-levelling work rolls, which are arranged one after the other, with formation of a strecher-leveller zone and wherein the stretcher-leveller work rolls are so arranged offset relative to one another that the metal strip is deflected at each strecher-leveller work rolls, characterised in that the strip is subjected to a stretching process between driver and reel by means of the arrangement of strecher-leveller work rolls behind the driver. Accordingly, the present invention also relates to plant for reshaping metal strip, consisting of a rolling train with downstream cooling path, driver and reel for carrying out the method as described herein, characterised in that two strecher-leveller work rolls of a common type are provided in the region between the driver and the reel, " The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWING In the drawing: Fig. 1 is a schematic illustration of in-line stretcher-leveller rolls according to the present invention arranged between a driver and a reel of a hot strip rolling mill; Fig. 2 is a schematic illustration of the end portion of a conventional hot strip rolling mill; Figs. 3 and 4 are schematic illustrations of embodiments of a stretcher-leveller zone formed by stretcher-leveller work rolls of the first type; Figs. 5 to 7 are schematic illustrations of embodiments of the stretcher-leveller zone formed by stretcher-leveller work rolls of the first and second type,- Fig. 8 is a diagrammatic illustration of the stress conditions in the metal strip when the roll of the second type has a negative crown,- Fig. 9 is a diagrammatic illustration of the stress conditions in the metal strip when the roll of the second type is constructed of two parts; Fig. 10 is a sectional view of the roll of Fig. 9; Figs, lla, b are schematic illustrations of mechanical adjusting members of the stretcher-leveller work roll; Fig. 12 is a diagram showing a stretcher-leveller model for the optimum adjustment of the stretcher-leveller work rolls; Fig. 13 is a schematic illustration of the stretcher-leveller zone formed exclusively by the driver rolls; Fig. 14 is a schematic illustration of the stretcher-leveller zone formed by a roller table roller and a lower driver roll; and Fig. 15 is a schematic illustration of the arrangement of the stretcher-leveller rolls which are pressed against each other shortly before the strip end leaves the last roll stand. DESCRIPTION OF THE PREFERRED EMBODIMENTS Following the rolling process in a hot strip rolling mill, the metal strip 1 travels over guide rollers over a driver 2 composed of an upper driver roll 3 and a lower driver roll 4 toward a reel 5 where the strip is reeled into a coil for further transport, usually to a cold rolling mill, as shown in Fig. 2 in connection with a conventional plant. Fig. 2 shows that, in accordance with the present invention, a stretcher-leveller zone 6 is provided between the driver 2 and the reel 5. The stretcher-leveller zone 6 is formed by two successively arranged cylindrical stretcher-leveller work rolls 7 and a stretcher-leveller work roll of the second type 8. Cooling systems 9a, in the illustrated embodiment in the form of spray water nozzles, for influencing the strip temperature over the strip or the thickness thereof are arranged between the work rolls 7 and 8 which are driven independently of each other. Another cooling system 9b is arranged closely in front of the coil. This cooling system 9b is schematically illustrated in Fig. 1 as a spray nozzle. Using this cooling system 9b, it is additionally possible to apply a gliding agent onto the strip in order to improve the gliding properties of the strip layers relative to each other during the cooling of the coil. The strip material travels alternatingly over or under the stretcher-leveller work rolls 7, 8. The rolls are offset relative to each other in respect to the axis of rotation in such a way that the metal strip 1 is deflected at each of the stretcher-leveller work rolls. By interfering with the straight strip travel, existing stresses in the strip are influenced or new stresses are produced which have an advantageous effect on the planarity of the strip. Figs. 3 and 4 show embodiments of the stretcher-leveller zone 6 which is formed either by two or by three cylindrical stretcher-leveller work rolls 7. By means of the arrangement of the stretcher-leveller work rolls 7 following the driver 2, it is possible to eliminate non-planarities produced, in the driver 2 prior to reeling the strip. The embodiment of Fig. 5 corresponds of Fig. 3 except that an additional stretcher-leveller work roll of the second type 8 is arranged following the driver 2. Fig. 6 shows the embodiment of the stretcher-leveller zone 6 of Fig. 4 except that, also in this case, a stretcher-leveller work roll of the second type 8 is provided as the last station of the metal strip before the reeling process. Fig. 7 shows a constellation of the rolls which is similar to that of Fig. 6. The difference is that the lower driver roll 4 is utilized as the first stretcher roll. Fig. 8 illustrates the stress conditions which exist when a stretcher-leveller work roll of the second type 8 with a negative crown is used. The above-described rolling conditions as well as high loads and wear of the rolls in the rolling plant produce non-planarities in the metal strips and excessive stresses at the strip edges. In order to compensate the planarity changes from the hot state to the cold state, a stretcher-leveller work roll 8a with a negative crown is provided. This makes it possible to produce a length change at the strip edges and to produce in the strip treated in this manner a positive stress with a maximum in the middle and minimum stresses at the edges. When a stretcher-leveller work roll 8b composed of two parts is used, the stress distribution of the strip, diagrammatically shown in Fig. 9, can be influenced in dependence on its width, i.e., its non-planarity. As a result, a strip elongation of a higher degree, i.e., not parabolically, is achieved in order to advantageously influence the cold planarity. Fig. 10 is a schematic illustration of the roll 8b composed of two parts 9 in contact with the strip 1. The roll parts 9 are shiftable back and forth relative to each other. They are either mounted fixedly or so as to swing on a shaft 10. In order to be able to better influence the properties of the stretcher-leveller work rolls it is proposed to provide the rolls with mechanical adjusting members. Possibilities in this connection are, for example, roll bending, an adjustable support roll or rolls or an inflatable roll. This makes it possible to variably influence the bending of the stretcher-leveller work rolls and, thus, the effect on the strip under load. Fig. 11a schematically shows the support of a stretcher-leveller work roll, wherein the bearing pins 11 are influenced by roll bending 12. Fig. lib illustrates the influence of one or two adjustable back-up rolls 13 and the arrangement thereof relative to the stretcher-leveller work rolls 7. A plurality of influencing variables must be taken into consideration for the optimum adjustment of adjustment positions of the stretcher-leveller work rolls and the contact pressure as well as the adjustment of the mechanical adjustments for influencing the roll bending. The influencing variables are used as adjustment variables within control circuits. Fig. 12 provides an overview of the influencing variables. The influences are, on the one hand, the strip contour, the strip temperature distribution, the strip thickness and strip width, the strip tension distribution and the strip tension level, the driver roll stiffness and the force and shape thereof (thermal crown, surface shape, wear) as well as the strip material properties in dependence of the deformation speed and temperature. Added to this are the elastic behavior, the thermal behavior and the wear behavior of the stretcher-leveller work rolls. Additionally received by the stretcher-leveller model are data concerning the planarity change during cooling of the coil and informations obtained from measured cold planarity evaluations. In the embodiment utilizing a tension measuring roller for measuring the planarity, the measured hot planarity following the stretcher-leveller zone also is included as an adjustment variable in the stretcher-leveller model. After entering these parameters it is possible to determine and adjust an optimum adjusting position, i.e., depth of insertion, as well as an optimum contact pressure of the stretcher-leveller work rolls. In addition, it is possible to determine from this computation the quantity of cooling water over the strip width for strip zone cooling. In addition, an activation of the mechanical adjustment members for influencing bending of the stretcher rolls is possible. Examples of the mechanical adjustment members are roll bending, adjustable back-up rolls or inflatable rolls. Also provided as an adjustment variable which can be influenced is the strip tension level which may be different over the strip length. It is provided in this connection that the adjustment members of the stretcher-leveller rolls and, thus, the tension level is adjustable so as to be different over the strip length. This means that different desired values are provided for the individual adjustment members. The values which have been picked up can also be utilized as variables for regulating the cooling device arranged following the finishing train, so that, for example, the temperature distribution is made uniform over the strip width already by an adjusted cooling. Various cooling patterns are conceivable, for example, as disclosed in Patents DE 32 30 866 or EP 0 449 003 Bl. To be taken into consideration is the fact that the strip cools more quickly at the edge than it does in the middle. Reduced cooling at the edges achieved, for example, by rendering the spray nozzles of a cooling beam inactive, compensates for these different temperatures over the strip width and produces a strip with a more uniform temperature distribution. Fig. 13 shows another embodiment of an installation for carrying out the proposed method, wherein the stretcher-leveller zone is formed exclusively by the upper driver roll 3 and the lower driver roll 4. After the reel has grasped the strip beginning, as shown in Fig. 13a, the upper driver roll 3 is swung downwardly and on the side of the lower driver roll 4, as shown in Figs. 13b, c. In this position, the driver rolls 3, 4 operate as two stretcher-leveller work rolls. In this embodiment the stretcher-leveller zone is located following the original position of the driver rolls. A gap 14 may optionally be adjusted between the lower driver roll 4 and the upper driver roll 3 when the driver roll 3 is in the downwardly moved position, as shown in Fig. 13c. Finally, in accordance with the embodiment of Fig. 14, the stretcher-leveller zone 6 is formed by a roll 15 of the roller table and by the lower driver roll 4 of the driver 2. For achieving a bending affect, the roll 16 is swung under the pass line. Fig. 15 schematically shows an advantageous arrangement of the stretcher-leveller rolls shortly before the strip end leaves the finishing train. In this arrangement, the stretcher-leveller roll 7, for example, of the first type, is pressed against a roll 17 arranged therebelow in order to maintain the necessary backward tension. If no roll 17 is provided, a greater immersion depth or a greater bending dimension of the stretcher-leveller roll is selected in order to maintain the bending and stretching process when the strip end leaves the finishing train. The method and the installation according to the present invention can be used generally in the manufacture of metal products. The invention is particularly intended for processing steels and aluminum. While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. WE CLAIM 1. Method of reshaping metal strip in a hot strip rolling mill, wherein the rolling strip after running through a finishing train and a cooling path is fed by way of a driver, which consists of an upper and a lower driver roller, to a coiling device, wherein the metal strip (1) in a region between the end of the cooling path and the coiling device is led in alternation above and below at least two stretch-levelling work rolls (7, 8), which are arranged one after the other, with formation of a strecher-leveller zone (6) and wherein the stretcher-leveller work rolls (7, 8) are so arranged offset relative to one another that the metal strip is deflected at each strecher-leveller work rolls (7, 8), characterised in that the strip is subjected to a stretching process between driver (2) and reel (5) by means of the arrangement of strecher-leveller work rolls (7, 8) behind the driver (2). 2. Plant for reshaping metal strip, consisting of a rolling train with downstream cooling path, driver and reel for carrying out the method as claimed in claim 1, characterised in that two strecher-leveller work rolls of a common type are provided in the region between the driver (2) and the reel (5). 3. Plant as claimed in claim 2, wherein in each instance two strecher-leveller work rolls of one type are used in combination with a strecher-leveller rolls of another type. 4. Plant as claimed in claim 2, wherein in each instance two strecher-leveller work rolls of one type are used in common with an additional strecher-leveller work rolls of the same type. 5. Plant as claimed in any one of claims 2 to 4, wherein the strecher-leveller work rolls (7) of a first type are cylindrical. 6. Plant as claimed in any one of claims 2 to 4, wherein the stirecher-leveller work rolls of a second type (8) has a negative or positive roll crown (8a). 7. Plant as claimed in claim 6, wherein the strecher-leveller work rolls of the second type (8b) is composed of two stretcher rolls bodies (9) which are separated from one another and fixedly mounted or are mounted on a shaft (10) to be oscillating, the stretch roller bodies each being displaceable oriented with respect to the strip edge. 8. Plant as claimed in claims 2 to 7, wherein the lower roll of the driver (3) is used as a strecher-leveller rolls of the first type (7). 9. Plant as claimed in any one of claims 2 to 8, wherein the strecher-leveller work rolls (7, 8) are independently drivable. 10. Plant as claimed in any one of claims 2 to 9, wherein the strecher-leveller work rolls (7, 8) of the first and second type are provided with mechanical setting elements such as roll bending means, adjustable backing rolls and inflatable rolls. 11. Plant as claimed in any one of claims 2 to 10, wherein a strip zone cooling unit (9a), particularly a water cooling, is provided in the strecher-leveller zone (6). 12. Plant as claimed in any one of claims 2 to 10, wherein a cooling system (9b) is provided for application of a lubricant to the strip. 13. Plant for reshaping metal strip, consisting of a rolling train with downstream cooling path, driver and reel for carrying out the method as claimed in claim 1, characterised in that the upper and lower rolls of the driver (3, 4) take over the function of stretcher-leveller work rolls by pivotation of the upper driver roll laterally downwardly. 14. Plant as claimed in any one of the preceding claims, wherein a planarity measuring roller is arranged after the stretcher-leveller zone (6) as seen in strip running direction. 15. Plant as claimed in any one of the preceding claims, wherein one stretcher-leveller rolls (7, 8) is constructed as a segmented tension measuring roller. 16. Plant as claimed in any one of the preceding claims, wherein at least one driver device, which consists of two rolls, for increase in tension stress is provided in front of the stretcher-leveller zone as seen in strip running direction. 17. Method as claimed in claim 1, wherein the adjustment of the stretcher-leveller rolls relative to one another and to the strip is regulated in dependence on the strip characteristics and/or on the characteristics of the driver rolls or stretcher-leveller work rolls by means of a first regulating circuit. 18. Method as claimed in claim 1, wherein the settings of the cooling stretch are regulated in dependence on the strip characteristics and/or on the characteristics of the driver rolls or strecher-leveller work rolls by means of a second regulating circuit. 19. Method as claimed in claim 1, wherein the mechanical setting elements of the stretcher-leveller work rolls are regulated in dependence on the strip characteristics by means of a third control circuit. 20. Method as claimed in claim 1, wherein the level of strip tension is regulated in dependence on the strip characteristics and/or on the characteristics of the driver rolls or stretcher-leveller work rolls by means of a fourth control circuit. 21. Method as claimed in claims 17 to 20, wherein the first and/or the second and/or the third and/or the fourth control circuits are coupled together and refer back to common desired values. 22. Method as claimed in any one of claims 17 to 20, wherein the strip contour, the strip temperature, the strip thickness and width, the strip tension distribution and/or the planarity characteristic of the strip after running through the stretcher-leveller zone come into play as strip characteristics. 23. Method as claimed in any one of claims 17 to 20, wherein the driver rolls stiffness, force and shape and/or the thermal and/or wear properties of the stretcher-leveller rolls come into play as characteristics of the driver rolls or strecher-leveller work rolls. 24. Method of reshaping metal strip in a hot rolling mill, substantially as herein described with reference to the accompanying drawings. 25. Plant for reshaping metal strip, substantially as herein described with reference to the accompanying drawings.

Documents:

2189-mas-1998 abstract.jpg

2189-mas-1998 abstract.pdf

2189-mas-1998 claims-duplicate.pdf

2189-mas-1998 claims.pdf

2189-mas-1998 correspondence-others.pdf

2189-mas-1998 correspondence-po.pdf

2189-mas-1998 description (complete)-duplicate.pdf

2189-mas-1998 description (complete).pdf

2189-mas-1998 drawings-duplicate.pdf

2189-mas-1998 drawings.pdf

2189-mas-1998 form-19.pdf

2189-mas-1998 form-2.pdf

2189-mas-1998 form-26.pdf

2189-mas-1998 form-4.pdf

2189-mas-1998 form-6.pdf

2189-mas-1998 others.pdf

2189-mas-1998 petition.pdf