Straightening device, its tension roll set, leveler and method of operating a straightening device

Abstract

The invention relates to a tensioning roller set for a straightening device for straightening strip material or for a smoothing device for finishing strip material, comprising a first tensioning roller having a first roller axis and at least one second tensioning roller having a second roller axis, wherein the first tensioning roller is a flatness measuring roller, has a force sensor for measuring a radial force applied to the circumferential surface of the flatness measuring roller, and the second tensioning roller is provided with a drive by means of which a torque about the second roller axis can be applied to the second tensioning roller, wherein either the first tensioning roller is embodied without a drive or an auxiliary drive is provided for the first tensioning roller by means of which a torque about the first roller axis can be applied to the first tensioning roller, wherein the auxiliary drive for the first tensioning roller is embodied significantly weaker than the drive for the second tensioning roller.

Description

TECHNICAL FIELD

[0001] The present invention relates to a tensioning roller set of a straightening device for straightening a strip. The present invention also relates to a straightening device for straightening a strip. The present invention also relates to a levelling device for finishing a strip. The present invention also relates to a method for operating a straightening device or a levelling device. BACKGROUND

[0002] Increasingly high demands are placed on the quality of products and semi-finished products made from sheet metal and strip. Different customers require very small-tolerance sheet metal products based on visual and process-technological reasons. The main quality feature of such sheet metal products is its flatness. The flatness requirements are often not met during the rolling, which is determined by different influences. In order to eliminate the unevenness, a strip straightening method is therefore used subsequently. Length compensation is achieved by plastically stretching shorter strip sections in the strip. Thereby, for example, intermediate or edge waves can be eliminated. This results in the partial wave-like strip sections being plastically elongated to different degrees before the straightening process.

[0003] For straightening strips, continuous operating straightening processes are generally used, which act in the manner of stretch bending straightening, stretching or a combination of stretching and stretch bending straightening. All three have in common that they have

[0004] • an entry into the tensioning roller set, in which the strip tension is higher than in the strip tension in the production line,

[0005] • a stretching zone or a bending stand, and

[0006] • an exit from the tensioning roller set, in which the strip tension is again reduced to the production line level.

[0007] In order to be able to set the stretching zone or / and the bending stand optimally, it is necessary to measure the flatness of the strip continuously.

[0008] In general, the installation space in the stretching zone or before or after the bending stand is very narrow. The installation space between the exit from the tensioning roller combination and, for example, the coiler is also narrow.

[0009] From EP 1 789 211 B1 a strip processing device with a tensioning roller pair is known, in which the strip is guided over the tensioning rollers of the tensioning roller pair and the tension of the strip is increased or decreased by the tensioning rollers between the entry of the tensioning roller and the exit of the tensioning roller, wherein the tensioning rollers have at least one measuring sensor arranged on the periphery of the tensioning roller, which is used to detect the stress distribution in the strip.

[0010] A stretch-bend levelling plant with a supply device for introducing a strip material into a high-tension region and a low-tension region in the direction of movement is known from DE 10 2018 111 627 A1, wherein the low-tension region is arranged downstream of the high-tension region in the direction of movement. The known bend levelling plant is provided with a bend levelling device which is arranged in the high-tension region. At least one measuring system for determining a first measured value in the high-tension region is also known. At least one measuring system for determining a second measured value in the low-tension region is also provided. SUMMARY

[0011] In this context, it is an object of the present application to propose a levelling device for levelling strip material or a tensioning roller set for a temper mill, which can better level strip material when it is used in a levelling device or which can better perform temper rolling when it is used in a temper mill.

[0012] The object of the present application is achieved by the tensioning roller set, the levelling device, the temper mill according to the present application and the method according to the present application.

[0013] The basic idea underlying the present application is to configure the tensioning rollers of a tensioning roller set as proposed in EP 1 789 211 B1 as flatness measuring rollers, wherein the tensioning roller set is improved according to the present application in such a way that although a second tensioning roller is provided with a drive by means of which a torque about the second roller axis can be applied to the second tensioning roller, the first tensioning roller is embodied according to the present application without a drive or although the first tensioning roller is provided with an auxiliary drive by means of which a torque about the first roller axis can be applied to the first tensioning roller, this auxiliary drive for the first tensioning roller is embodied more weakly than the drive for the second tensioning roller.

[0014] It has been found that in a tensioning roller provided with a drive, the required torque is usually provided on one side via the main journal of the tensioning roller. When the strip tension is applied, the torque applied to the stretching roller via the drive acts against the strip retraction, which causes the roller body of the stretching roller and possibly the coating material present to be deformed or twisted in the elastic range at this time. This deformation of the roller body of the tensioning roller and possibly the coating material present falsifies the measurement of the force sensor.

[0015] This measurement error can now be avoided or reduced according to the present application by embodying the first tensioning roller as a flatness measuring roller or by embodying it without a drive or only with a weaker auxiliary drive. Thereby, it is possible to better level strip material when using such a tensioning roller set in a levelling device, since the measurement of the flatness measuring roller is better. It is also possible to better perform temper rolling when using such a tensioning roller set in a temper mill, since the measurement of the flatness measuring roller is better.

[0016] The invention relates to a tensioning roller set of a straightening device for straightening strip material. It is intended that the advantages of the invention are already achieved in a roller set having only a first tensioning roller and a second tensioning roller. Preferably, however, the tensioning roller set according to the invention has a first tensioning roller, a second tensioning roller and a third tensioning roller, particularly preferably also a fourth tensioning roller, more preferably also a fifth tensioning roller, very particularly preferably also a sixth tensioning roller.

[0017] As is also proposed in EP 1 789 221 B1, the first tensioning roller is a flatness measuring roller which has a force sensor for measuring the radial force exerted on the circumferential surface of the flatness measuring roller.

[0018] Embodiments are conceivable in which the tensioning roller set has a plurality of flatness measuring rollers, as is described, for example, in DE 10 2019 006 788. In the preferred embodiment, however, the tensioning roller set has only one flatness measuring roller. By limiting the flatness measuring roller to one within the tensioning roller set, the costs for the tensioning roller set can be reduced.

[0019] The flatness measuring roller can be embodied according to the type of measuring roller described in DE 42 36 657 A1 or according to the type of measuring roller described in DE 196 16 980 A1 or according to the type of measuring roller described in DE 102 07 501 C1 or according to the type of measuring roller described in DE 20 20 07 00 106 U1 or according to the type of measuring roller described in EP 1 469 955 B1. The measuring roller can also be embodied according to the type of measuring roller described in WO 2020 / 120328 A1 or WO 2020 / 120329 A1.

[0020] The measuring roller has a measuring roller body. Preferably, the measuring roller body has a closed circumferential surface. In the preferred embodiment, the measuring roller body is a solid roller which extends along a longitudinal axis. A solid roller is understood to mean a measuring roller body which is made in one piece and which is made to its shape by means of a deformation method, for example casting, and / or which is made to its geometry from a one-piece semi-finished product by a separating method, in particular by cutting, in particular by turning, drilling, milling or grinding. In the preferred embodiment, the measuring roller necks for rotatably supporting the measuring roller in, for example, a ball bearing, which are respectively arranged at the end sides of the measuring roller, are also part of the one-piece body in such a measuring roller body which is constructed as a solid roller. It is also conceivable, however, as is shown, for example, in DE 20 2014 006 820 U1, in which the main part of the measuring roller body is embodied as a cylindrical solid roller which has a cover plate arranged at the end side on which the measuring roller necks are embodied. The measuring roller body can also be embodied, for example, as shown in DE 20 2014 006 820 U1, in which the main part of the measuring roller body is embodied as a cylindrical solid roller which has a cover plate arranged at the end side on which the measuring roller necks are embodied. Figure 2 Figure 3 ​The measuring roller body in the embodiment is configured in the same way as in which the measuring roller body is configured with molded journal and the cover tube is pushed onto the measuring roller body. But in the particularly preferred embodiment the measuring roller has no cover tube, but is embodied as a solid roller. Embodiments are conceivable in which the measuring roller body is formed from individual disks arranged side by side, as shown for example in DE 26 30 410 C2.

[0021] The measuring roller body of the measuring roller preferably has a closed circumferential surface. This can be achieved for example in that the measuring roller body is configured as a solid roller and all recesses provided in the measuring roller body are configured in such a way that no recess leads from a recess to the circumferential surface. The recesses are particularly preferably embodied axially in this embodiment and have an opening on one end side of the measuring roller body or are provided with a transverse channel within the measuring roller body, which leads further radially into the interior of the measuring roller body starting from the recess, for example to a collection channel in the middle of the measuring roller body. The closed circumferential surface of the measuring roller body can also be achieved in that the recesses in the embodiment with the recesses directed in the direction of the circumferential surface are closed by a closure element. Such a closure element can be a cover tube that completely surrounds the base body of the measuring roller body, as shown for example in DE 10 2014 012 426 A1 Figure 3 and in Figure 4. But the closure element can also be configured according to the type of the cover shown in DE 197 47 655 A1. But in the preferred embodiment the measuring roller has no cover tube, but is embodied as a solid roller, or no recess leads from a recess to the circumferential surface or such or the recesses are directed in the direction of the circumferential surface, but are closed by a closure element, for example a cover. It is also conceivable that the circumferential surface of the solid roller or the circumferential surface of the cover tube is coated, for example for reducing friction or for protecting the strip-shaped material that needs to be guided over the measuring roller.

[0022] At least one recess is provided in the measuring roller body of the measuring roller. It has been found that the advantages of the present application can already be achieved by a single recess in the measuring roller body. Thus it is conceivable in the flatness measurement to provide information about the flatness of the strip-shaped material guided over the measuring roller per revolution of the measuring roller.

[0023] In a preferred embodiment, the measurement roller body has a plurality of recesses. In a preferred embodiment, the recesses are equally spaced in the radial direction from the longitudinal axis of the measurement roller body. In a preferred embodiment, all recesses are arranged equidistantly from one another in the circumferential direction. However, it is also conceivable to provide a first group of recesses which is particularly preferably equally spaced in the radial direction from the longitudinal axis and arranged equidistantly in the circumferential direction, and at least one further recess in addition to the first group of recesses, the radial spacing of which from the longitudinal axis is different from that of the recesses of the first group and / or which is not equidistant in the circumferential direction from the remaining recesses as the remaining recesses are from one another. Thus, for example, it is conceivable for the measurement roller to be embodied in terms of flatness measurement as a measurement roller of the prior art, for example as a solid roller as known from DE 102 07 501 or as a measurement roller as known from DE 102 014 012 426 A1, but then for the further configuration, the measurement roller of the prior art is provided with a further recess which is embodied outside the scope, by means of which further measurement is carried out, for example. Preferably, the recesses mentioned in this paragraph are recesses which extend in the axial direction of the measurement roller body. It is also conceivable for the measurement roller to have a single recess and for all force sensors of the measurement roller to be arranged in the single recess, for example a single recess which extends axially.

[0024] In a preferred embodiment, the measurement roller body has a closed circumferential surface and is closed on the end sides respectively by an end side.

[0025] In a preferred embodiment, the measurement roller has a main journal. In a preferred embodiment, the main journal is configured on the end side in embodiments of the measurement roller in which the measurement roller has an end side.

[0026] In a preferred embodiment, the measurement roller body is embodied cylindrically.

[0027] In a preferred embodiment, the measurement roller has at least one recess in the measurement roller body, the at least one recess being arranged spaced apart from the circumferential surface, wherein the recess is not open towards the circumferential surface or does not continue from the recess with a further recess, for example a hole, which leads to the circumferential surface. In an alternative preferred embodiment, the recess leads from the circumferential surface into the interior of the measurement roller body, but is closed by a closure element. In a preferred embodiment, in embodiments in which the measurement roller has a plurality of recesses in the measurement roller body which are arranged spaced apart from the circumferential surface, either all recesses are embodied such that no recess or no hole leads from the recess to the circumferential surface (neither the recess itself leads to the circumferential surface), or several recesses are embodied such that no recess leads from the respective recess to the circumferential surface, while in the other recesses a recess is provided which leads in the direction towards the circumferential surface, but which is closed by a closure element. The closure element is a cover or, for example, a cover tube as described previously.

[0028] In preferred embodiments, the recess of the measuring roller body extends in a direction parallel to the longitudinal axis of the measuring roller body. According to preferred embodiments, if a plurality of recesses are provided in the measuring roller body, it is preferred that all recesses of the measuring roller body each extend in a direction parallel to the longitudinal axis of the measuring roller body. In preferred embodiments, the respective recess opens at least at one end thereof, preferably at both ends thereof, into an end face of the measuring roller body. A recess which terminates on one end side of the measuring roller body can be closed by an end cap, wherein the end cap only closes the recess. It is also conceivable that the end side of the measuring roller body as shown in Fig. 4, for example, in DE 10 2014 012 426 Al or Fig. 4 is entirely closed by a cover plate. Figure 1 and Figure 2 or the embodiment of the measuring roller body as shown in Fig. 4, for example, in DE 10 2014 012 426 Al or Fig. 4 is entirely closed by a cover plate.

[0029] In preferred embodiments, the recess is embodied in a longitudinal extension, wherein "longitudinal extension" is understood as the recess extending in a first direction (in the longitudinal direction of the recess) more than in a direction perpendicular thereto. In preferred embodiments, the extension of the recess in the longitudinal direction is twice as large or, particularly preferably, more than twice as large in the direction perpendicular thereto. In preferred embodiments, the longitudinal direction of the recess encloses an angle with the longitudinal direction of the measuring roller body which is less than 75°, particularly preferably < 45°, particularly preferably < 30°, particularly preferably < 10°, particularly preferably less than 5°. In preferred embodiments, the longitudinal direction of the recess is not perpendicular to the longitudinal axis of the measuring roller body. If it is conceivable in an embodiment that the longitudinal axis of the recess and the longitudinal axis of the measuring roller body do not intersect, the aforementioned design rule applies to the projection of the longitudinal axis of the recess onto the plane containing the longitudinal axis of the measuring roller body. The longitudinal axis of the recess is thus embodied in these embodiments in such a way that the projection of the angle which the longitudinal axis of the recess encloses with the longitudinal direction of the measuring roller body is less than 75°, particularly preferably < 45°, particularly preferably < 30°, particularly preferably < 10°, particularly preferably < 5°. In preferred embodiments in which the recess extends parallel to the longitudinal axis of the measuring roller body, the longitudinal axis of the recess obviously does not intersect the longitudinal axis of the measuring roller body, and the projection of the longitudinal axis onto the plane containing the longitudinal axis of the measuring roller body also does not intersect the longitudinal axis of the measuring roller body. A measuring roller with a recess embodied in longitudinal extension is shown, for example, in DE 20 2007 001 066 U1.

[0030] In preferred embodiments, the flatness measuring roller has an axial bore which extends parallel to the first roller axis, wherein the force sensor is arranged in the axial bore. According to the application, the flatness measuring roller is no longer or only to a low extent subjected to a torsional force. Thereby, it is also possible to use a roller embodiment in which the sensor is not only mounted in a radial bore but also in an axial bore as described, for example, in EP 1 469 955 Al.

[0031] In a preferred embodiment, the flatness measuring roller has a surface coating. Especially preferably, the flatness measuring roller has a coating consisting of tungsten carbide or chromium. The surface coating can also be embodied as a rubber or polyurethane coating.

[0032] In the present description, the first and the second tensioning roller of the tensioning roller set are mentioned and, in the context of the preferred embodiment, the third and the fourth tensioning roller are mentioned and, in part, the fifth and the sixth tensioning roller. The use of the ordinal numbers "first", "second", "third", "fourth", "fifth" and "sixth" is not mandatory, but only in the preferred embodiment the strip is guided in the order of its ordinal number over the existing tensioning rollers of the tensioning roller set, i.e. first over the first tensioning roller, then over the second tensioning roller, etc. The present invention first of all relates to the provision of a tensioning roller having a drive within the tensioning roller set, the so-called "second tensioning roller", and also to a flatness tensioning roller, called "first tensioning roller", which is designed without a drive or with an auxiliary drive. The present invention first of all does not determine in which spatial position the first and the second tensioning roller are located relative to each other. It is not necessary for the achievement of the advantages of the present invention that the flatness measuring roller ("first tensioning roller") is the first tensioning roller in space over which the strip runs when it enters the tensioning roller set. It is also not necessary for the achievement of the advantages of the present invention that the "second tensioning roller" is the tensioning roller which is arranged immediately behind the flatness measuring roller ("first tensioning roller") in the direction of travel of the strip. Embodiments are therefore also conceivable in which the flatness measuring roller ("first tensioning roller") is the last tensioning roller of the tensioning roller set or is arranged between the first and the last tensioning roller of the tensioning roller set. Embodiments are also conceivable in which further tensioning rollers, which can be driven or can not be driven, are arranged between the flatness measuring roller ("first tensioning roller") and the driven second tensioning roller.

[0033] In a preferred embodiment, however, the second tensioning roller is the tensioning roller of the set of tensioning rollers over which the strip is guided after it has left the first tensioning roller which is embodied as a flatness measuring roller. In this very particularly preferred embodiment, the first tensioning roller which is embodied as a flatness measuring roller is the tensioning roller of the set of tensioning rollers over which the strip is first run when it enters the set of tensioning rollers. In the preferred embodiment provided with a third tensioning roller, the third tensioning roller is arranged behind the second tensioning roller in the direction of travel of the strip, particularly preferably directly behind the second tensioning roller. In the preferred embodiment provided with a fourth tensioning roller, the fourth tensioning roller is arranged behind the third tensioning roller in the direction of travel of the strip, particularly preferably directly behind the third tensioning roller. In the preferred embodiment provided with a fifth tensioning roller, the fifth tensioning roller is arranged behind the fourth tensioning roller in the direction of travel of the strip, particularly preferably directly behind the fourth tensioning roller. In the preferred embodiment provided with a sixth tensioning roller, the sixth tensioning roller is arranged behind the fifth tensioning roller in the direction of travel of the strip, particularly preferably directly behind the fifth tensioning roller.

[0034] The preferred arrangement of the individual tensioning rollers described in the preceding paragraph is particularly suitable for embodiments in which the set of tensioning rollers according to the application is arranged behind the stretching zone or behind the bending stand and is intended to indicate at which flatness quality the strip leaves the stretching zone or the bending stand. The preferred arrangement is also suitable for a set of tensioning rollers which is arranged behind the uncoiler and is intended to indicate at which flatness quality the strip leaves the capstan.

[0035] In a preferred alternative embodiment, however, the first tensioning roller which is embodied as a flatness measuring roller is the tensioning roller over which the strip is guided after it has left the second tensioning roller. In this very particularly preferred embodiment, the first tensioning roller which is embodied as a flatness measuring roller is the last tensioning roller of the set of tensioning rollers over which the strip leaves when it exits the set of tensioning rollers. In this preferred embodiment, the first tensioning roller which is embodied as a flatness measuring roller is therefore the last tensioning roller of the set of tensioning rollers. In the preferred embodiment provided with a third tensioning roller, the third tensioning roller is arranged in front of the second tensioning roller in the direction of travel of the strip, particularly preferably directly in front of the second tensioning roller. In the preferred embodiment provided with a fourth tensioning roller, the fourth tensioning roller is arranged in front of the third tensioning roller in the direction of travel of the strip, particularly preferably directly in front of the third tensioning roller. In the preferred embodiment provided with a fifth tensioning roller, the fifth tensioning roller is arranged in front of the fourth tensioning roller in the direction of travel of the strip, particularly preferably directly in front of the fourth tensioning roller. In the preferred embodiment provided with a sixth tensioning roller, the sixth tensioning roller is arranged in front of the fifth tensioning roller in the direction of travel of the strip, particularly preferably directly in front of the fifth tensioning roller.

[0036] The preferred arrangement of the individual tensioning rolls described in the preceding paragraph is particularly suitable for embodiments of the tensioning roll set according to the application which are to be arranged before the coiler and are intended to indicate with which flatness quality the strip is wound onto the coiler. The preferred arrangement is also suitable for tensioning roll sets which are to be arranged before the stretching zone or the bending stand and are intended to indicate with which flatness quality the strip enters the stretching zone or the bending stand.

[0037] The application provides a drive for the second tensioning roll, by means of which a torque about the second roll axis can be applied to the second tensioning roll. This drive is particularly preferably provided with an electric motor and a transmission, by means of which an adjustable torque can be generated. The drive applies the torque particularly preferably to one of the main journal of the tensioning roll on one side. In a preferred embodiment, the drive is embodied to apply a maximum torque in the range of 1-100 kNm to the tensioning roll.

[0038] In a preferred embodiment, the first tensioning roll is embodied without a drive and all the remaining existing tensioning rolls are embodied to be driven. In a preferred embodiment, the first tensioning roll has an auxiliary drive and all the remaining existing tensioning rolls are embodied to be driven.

[0039] In the tensioning roll set according to the application, the first tensioning roll embodied as a flatness measuring roll is embodied without a drive according to the first embodiment. In this embodiment of the tensioning roll set according to the application, no drive is provided for the first tensioning roll which can apply a torque about the first roll axis to the first tensioning roll. Thus, the first tensioning roll is embodied as an idler roll.

[0040] In an alternative according to the application, although an auxiliary drive is provided for the first tensioning roll, by means of which a torque about the first roll axis can be applied to the first tensioning roll. However, the auxiliary drive for the first tensioning roll is embodied to be weaker than the drive for the second tensioning roll. The drive for the second tensioning roll is embodied such that it can follow the basic idea of the tensioning roll set for increasing or decreasing the strip tension, can make it necessary for the auxiliary drive for the first tensioning roll to rotate the first tensioning roll and to thread the strip through and to accelerate and brake the roll when required at high speed of the straightening device. However, such an auxiliary drive is not required for the actual operation of the straightening device and is switched off or adjusted to a torque of 0 Nm after the start-up phase in a preferred embodiment of the method according to the application.

[0041] In a preferred embodiment, the auxiliary drive is one order of magnitude weaker than the drive of the second tensioning roll. In a preferred embodiment, the auxiliary drive generates a maximum torque in the range of 0.03 to 0.3 kNm.

[0042] In a preferred embodiment, the third tensioning roller is provided with a third roller axis. It is particularly preferred that the third tensioning roller is provided with a drive by means of which a torque about the third roller axis can be applied to the third tensioning roller. In a preferred embodiment, the drive for the third tensioning roller can generate a maximum torque which is at least twice as large as the maximum torque which can be generated by the drive for the second tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the third tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the second tensioning roller. In a preferred embodiment, the maximum torque which can be generated by the drive for the third tensioning roller is at least half as large as the maximum torque which can be generated by the drive for the second tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the second tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the third tensioning roller.

[0043] In a preferred embodiment, the fourth tensioning roller is provided with a fourth roller axis. It is particularly preferred that the fourth tensioning roller is provided with a drive by means of which a torque about the fourth roller axis can be applied to the fourth tensioning roller. In a preferred embodiment, the drive for the fourth tensioning roller can generate a maximum torque which is at least twice as large as the maximum torque which can be generated by the drive for the third tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the fourth tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the third tensioning roller. In a preferred embodiment, the maximum torque which can be generated by the drive for the fourth tensioning roller is at least half as large as the maximum torque which can be generated by the drive for the third tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the third tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the fourth tensioning roller.

[0044] In a preferred embodiment, the fifth tensioning roller is provided with a fifth roller axis. It is particularly preferred that the fifth tensioning roller is provided with a drive by means of which a torque about the fifth roller axis can be applied to the fifth tensioning roller. In a preferred embodiment, the drive for the fifth tensioning roller can generate a maximum torque which is at least twice as large as the maximum torque which can be generated by the drive for the fourth tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the fifth tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the fourth tensioning roller. In a preferred embodiment, the maximum torque which can be generated by the drive for the fifth tensioning roller is at least half as large as the maximum torque which can be generated by the drive for the fourth tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the fourth tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the fifth tensioning roller.

[0045] In a preferred embodiment, the sixth tensioning roller is provided with a sixth roller axis. It is particularly preferred that the sixth tensioning roller is provided with a drive by means of which a torque about the sixth roller axis can be applied to the sixth tensioning roller. In a preferred embodiment, the drive for the sixth tensioning roller can generate a maximum torque which is at least twice as large as the maximum torque which can be generated by the drive for the fifth tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the sixth tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the fifth tensioning roller. In a preferred embodiment, the maximum torque which can be generated by the drive for the sixth tensioning roller is at least half as large as the maximum torque which can be generated by the drive for the fifth tensioning roller. This is particularly suitable for applications in which the sequence in which the strip material runs over the tensioning rollers is such that the fifth tensioning roller is closer to the stretching zone, the bending stand or the levelling stand than the sixth tensioning roller.

[0046] In a preferred embodiment, the drive for the second tensioning roller applies a maximum torque T2 about the second roller axis to the second tensioning roller and the auxiliary drive for the first tensioning roller can apply a maximum torque T1 about the first roller axis to the first tensioning roller, wherein T1 is equal to or smaller than 7 / 8 of T2, particularly preferably equal to or smaller than 3 / 4 of T2, very particularly preferably equal to or smaller than half of T2, very particularly preferably equal to or smaller than 1 / 8 of T2, very particularly preferably equal to or smaller than 1 / 10 of T2.

[0047] In a preferred embodiment, the second tensioning roller is arranged relative to the first tensioning roller such that, seen in the direction of the running direction in which the strip material needs to run onto the tensioning roller group according to the application, a plane which is perpendicular to the horizontal plane and which contains the second roller axis is located

[0048] • perpendicular to the horizontal plane,

[0049] • arranged behind the first roller axis of the first tensioning roller in the running direction and

[0050] • running tangentially to the surface of the first tensioning roller

[0051] before a plane which is perpendicular to the horizontal plane,

[0052] In a preferred embodiment, the second roller axis is arranged in a horizontal plane which lies below the horizontal plane in which the first roller axis lies.

[0053] In a preferred embodiment comprising a third tensioning roller, the second tensioning roller and the third tensioning roller are arranged relative to the first tensioning roller such that

[0054] • such that a plane which is perpendicular to the horizontal plane and which contains the second roller axis is located on one side of a plane which is perpendicular to the horizontal plane and which runs tangentially to the surface of the first tensioning roller, and

[0055] • such that a plane which is perpendicular to the horizontal plane and which contains the third roll axis is located on the other side of the plane which is perpendicular to the horizontal plane and which runs tangentially to the surface of the first tensioning roll.

[0056] It is particularly preferred in this embodiment that a fourth tensioning roll is additionally provided, wherein the fourth tensioning roll is particularly preferably arranged between the first roll axis and the third roll axis as viewed in the horizontal direction.

[0057] In a preferred embodiment, the first roll axis and the second roll axis are parallel to one another. In a preferred embodiment, all of the roll axes of the tensioning rolls of the tensioning roll group are embodied parallel to one another. In a preferred embodiment, the second roll axis is embodied before the first roll axis and the fourth roll axis is embodied after the first roll axis and the third roll axis is embodied after the fourth roll axis as viewed in the horizontal direction. In a particularly preferred embodiment, a fifth roll axis is arranged after the third roll axis. In a particularly preferred embodiment, a sixth roll axis is arranged between the fifth roll axis and the third roll axis.

[0058] In the straightening device for straightening a strip according to the application, a front tensioning roll group and a rear tensioning roll group are provided. A stretching zone can be provided between the front tensioning roll group and the rear tensioning roll group. A bending stand can be provided between the front tensioning roll group and the rear tensioning roll group. A stretching zone and a bending stand can be provided between the front tensioning roll group and the rear tensioning roll group.

[0059] According to the application, the front tensioning roll group can be embodied as a tensioning roll group according to the application or the rear tensioning roll group can be embodied as a tensioning roll group according to the application. According to the application, the front tensioning roll group and the rear tensioning roll group can also both be embodied as a tensioning roll group according to the application.

[0060] In a preferred embodiment, a further flatness measuring roll is provided before the front tensioning roll group and / or after the front tensioning roll group and / or before the rear tensioning roll group and / or after the rear tensioning roll group. In a particularly preferred alternative, no further flatness measuring roll is provided before the front tensioning roll group and / or after the front tensioning roll group and / or before the rear tensioning roll and / or after the rear tensioning roll.

[0061] If the first tensioning roll embodied as a flatness measuring roll is the first tensioning roll on which the strip of the rear tensioning roll group runs as it exits the stretching zone or the bending stand, the flatness of the strip can be determined immediately after exiting the stretching zone or immediately after exiting the bending stand. If the first tensioning roll embodied as a flatness measuring roll according to the application is embodied as the last tensioning roll on which the strip of the front tensioning roll group runs before it exits the front tensioning roll group, the flatness of the strip can be determined immediately before the strip enters the stretching zone or immediately before the strip enters the bending stand by means of this arrangement.

[0062] But embodiments are also conceivable in which it is desired that the strip enters the straightening device according to the application with a certain flatness or leaves the straightening device according to the application with a certain flatness. It is therefore suitable if the first tensioning roller, which is embodied as a flatness measuring roller, is the first tensioning roller onto which the strip runs when it enters the front tensioning roller set. In this embodiment the flatness of the strip can be determined by means of the flatness measuring roller according to the application as it leaves the capstan. It can also be suitable if the first tensioning roller, which is embodied as a flatness measuring roller, is the last tensioning roller onto which the strip runs before it leaves the rear tensioning roller set. By means of this arrangement of the flatness measuring roller the flatness of the strip can be determined before it runs onto the capstan.

[0063] It is particularly preferred if the application is embodied according to one of the embodiments listed below:

[0064] In this connection the following table shows:

[0065] none = no flatness measuring roller at this location

[0066] one = one flatness measuring roller at this location

[0067] (1) = the first tensioning roller of the tensioning roller set is embodied as a flatness measuring roller, the first tensioning roller being arranged at an arbitrary position of the tensioning roller set

[0068] (2) = the first tensioning roller of the tensioning roller set is embodied as a flatness measuring roller, the first tensioning roller being the tensioning roller onto which the strip first runs

[0069] (3) = the first tensioning roller of the tensioning roller set is embodied as a flatness measuring roller, the first tensioning roller being the last tensioning roller of the tensioning roller set onto which the strip runs

[0070] (4) = the tensioning roller set has two tensioning rollers embodied as flatness measuring rollers

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082] The combination of a flatness measuring roller arranged in the set of tensioning rollers and a flatness measuring roller supported before and / or after the set of tensioning rollers has the disadvantage that more structural space is required for these embodiments, but the provision of a separate tensioning roller in addition to the tensioning rollers arranged in the set of tensioning rollers can provide the advantage that the flatness measuring roller in the set of tensioning rollers can be calibrated.

[0083] In a preferred embodiment, the strip is guided over the first tensioning roller and over the second tensioning roller, wherein

[0084] • the strip is wound around the first tensioning roller with a contact angle of at least 90°, particularly preferably at least 125°, particularly preferably at least 130°, particularly preferably at least 145°, particularly preferably at least 180°;

[0085] • and / or the strip is wound around the second tensioning roller with a contact angle of at least 90°, particularly preferably at least 125°, particularly preferably at least 130°, particularly preferably at least 145°, particularly preferably at least 180°.

[0086] In a preferred embodiment of the straightening device according to the application, the same number of driven tensioning rollers is arranged in the set of tensioning rollers in the front as in the set of tensioning rollers in the rear. In a preferred embodiment, the set of tensioning rollers in the front and the set of tensioning rollers in the rear have the same number of tensioning rollers, wherein the first tensioning roller, which is embodied as a flatness measuring roller, is embodied without a drive and is either arranged in the set of tensioning rollers in the front or in the set of tensioning rollers in the rear, the other set of tensioning rollers has no flatness measuring roller, but instead of a flatness measuring roller has an idler roller, the remaining tensioning rollers of the respective set of tensioning rollers being driven, so that the same number of driven tensioning rollers is arranged in the set of tensioning rollers in the front as in the set of tensioning rollers in the rear.

[0087] In a preferred embodiment, the set of tensioning rollers in the rear of the straightening device is a set of tensioning rollers according to the application, wherein the first tensioning roller is the first tensioning roller of the set of tensioning rollers onto which the strip drives after leaving the stretching zone and / or the bending stand. In addition or alternatively, the set of tensioning rollers in the front of the straightening device is a set of tensioning rollers according to the application, wherein the first tensioning roller is the tensioning roller of the set of tensioning rollers from which the strip enters the stretching zone and / or the bending stand. Alternatively, in another preferred embodiment, the set of tensioning rollers in the front of the straightening device is a set of tensioning rollers according to the application, wherein the first tensioning roller is the tensioning roller of the set of tensioning rollers onto which the strip drives from the uncoiler.

[0088] With the straightening device according to the application flatness measurements can be carried out after the stretching zone or the bending stand at the smallest possible distance. Thereby the dead zone distance is minimized. The application enables flatness measurement rolls in the high tension area without interference from the roll drives. Flatness measurements can be carried out in the straightening device in the tension area with only one measurement roll. The straightening device according to the application enables the flatness measurement roll diameter to be implemented with the same size as the remaining tensioning rolls of the tensioning roll stand. Thereby the bending stresses are minimized when the strip material changes direction around the roll body.

[0089] The tensioning roll stand according to the application can also be applied in a levelling device for finishing the strip material. The levelling device has:

[0090] a. a front tensioning roll stand,

[0091] b. a rear tensioning roll stand,

[0092] c. a levelling stand arranged between the front tensioning roll stand and the rear tensioning roll stand,

[0093] wherein

[0094] • the front tensioning roll stand is implemented as a tensioning roll stand according to the application,

[0095] and / or

[0096] • the rear tensioning roll stand is implemented as a tensioning roll stand according to the application.

[0097] The aforementioned disclosure for the embodiments of the straightening device according to the application can also be used as disclosure for the embodiments of the levelling device according to the application, wherein the disclosure for the levelling device is constituted by the terms "straightening device" being replaced by "levelling device" and the term "stretching zone" being replaced by a rolling stand and the term "bending stand" being replaced by a rolling stand.

[0098] The method according to the application for operating a straightening device according to the application having a bending stand with settable bending rolls and a control device proposes that the control device carries out a control intervention at at least one actuator of the straightening device, for example a settable bending roll or a tensioning roll stand, based on the measurement results of the force sensors.

[0099] The method according to the application for operating a levelling device according to the application having settable rolls and a control device proposes that the control device carries out a control intervention at at least one actuator of the straightening device, for example a settable bending roll or a tensioning roll stand, based on the measurement results of the force sensors.

[0100] As a supplement or alternative, the method according to the application for operating a straightening device according to the application or a levelling device according to the application, the straightening device or the levelling device is embodied such that an auxiliary drive is provided for the first tensioning roller, by means of which an around the first roll axis torque can be applied to the first tensioning roller, wherein the auxiliary drive for the first tensioning roller is embodied more weakly than the drive for the second tensioning roller, the auxiliary drive for the first tensioning roller is disconnected or adjusted to a drive torque of 0 Nm after a start-up phase and / or after the establishment of the strip tension.

[0101] The start-up phase in particular comprises the threading-in of the strip and the acceleration of the device up to the operating speed.

[0102] The method according to DE 10 2019 006 788 can be carried out by means of the tensioning roller set according to the application.

[0103] The application is particularly preferably applied in the straightening and / or levelling of strip material, preferably metal strips or sheets. BRIEF DESCRIPTION OF DRAWINGS

[0104] The application is described in detail below on the basis of the drawings, which show an embodiment of the application. Shown are:

[0105] Figure 1 A schematic side view of a straightening device according to the application is shown;

[0106] Figure 2 A schematic side view of a further straightening device according to the application is shown;

[0107] Figure 3 A schematic view of the forces acting on the measuring roller is shown. DETAILED DESCRIPTION

[0108] Figure 1 The straightening device 1 for straightening a strip 2 shown in Fig. 1 has a front tensioning roller set 3 and a rear tensioning roller set 4. Between the front tensioning roller set 3 and the rear tensioning roller set 4 a bending stand 5 is provided. In front of the front tensioning roller set 3 a capstan 6 is provided. In rear of the rear tensioning roller set 4 a capstan 7 is provided.

[0109] The strip 2 is unwound from the capstan 6, passes through the front tensioning roller set 3, through the bending stand 5, through the rear tensioning roller set 4 and is wound up by the capstan 7. The strip tension acting on the strip 2 is increased in the front tensioning roller set 3 and decreased in the rear tensioning roller set 4, so that the strip tension acting on the strip 2 is higher in the region of the bending stand 5 than before the front tensioning roller set 3 and after the rear tensioning roller set 4.

[0110] The rear tensioning roller set 4 has

[0111] • a first tensioning roller 8 having a first roller axis,

[0112] • a second tensioning roller 9 having a second roller axis,

[0113] • a third tensioning roller 10 having a third roller axis,

[0114] • a fourth tensioning roller 11 having a fourth roller axis,

[0115] wherein the first tensioning roller 8 is a flatness measuring roller having a force sensor for measuring a radial force (FR,1) applied to the circumferential surface of the flatness measuring roller.

[0116] A (not shown in detail) drive for the second tensioning roller 9 is provided, by means of which a torque about the second roller axis can be applied to the second tensioning roller 9. A (likewise not shown in detail) drive for the third tensioning roller 10 is also provided, by means of which a torque about the third roller axis can be applied to the third tensioning roller 10. A (likewise not shown in detail) drive for the fourth tensioning roller 11 is also provided, by means of which a torque about the fourth roller axis can be applied to the fourth tensioning roller 11.

[0117] The first tensioning roller 8 is implemented without a drive.

[0118] The front tensioning roller group 3 has

[0119] • a first tensioning roller 14 having a first roller axis,

[0120] • a second tensioning roller 15 having a second roller axis,

[0121] • a third tensioning roller 16 having a third roller axis,

[0122] • a fourth tensioning roller 17 having a fourth roller axis.

[0123] A (not shown in detail) drive for the second tensioning roller 15 is provided, by means of which a torque about the second roller axis can be applied to the second tensioning roller 15. A (likewise not shown in detail) drive for the third tensioning roller 16 is also provided, by means of which a torque about the third roller axis can be applied to the third tensioning roller 16. A (likewise not shown in detail) drive for the fourth tensioning roller 17 is also provided, by means of which a torque about the fourth roller axis can be applied to the fourth tensioning roller 17.

[0124] The first tensioning roller 14 is implemented without a drive.

[0125] In the straightening device 1 shown in Figure 2 Figure 1 ​The difference in the straightening device 1 shown is the construction of the rear tension roller group 4 and the construction of the front tension roller group 3. In addition to the first tension roller 8, the second tension roller 9, the third tension roller 10 and the fourth tension roller 11, the rear tension roller group 4 also has a fifth tension roller 12 and a sixth tension roller 13.

[0126] A driver (not shown in detail) is provided for the second tension roll 9, by means of which torque about the axis of the second roll is applied to the second tension roll 9. A driver (also not shown in detail) is also provided for the third tension roll 10, by means of which torque about the axis of the third roll is applied to the third tension roll 10. A driver (also not shown in detail) is also provided for the fourth tension roll 11, by means of which torque about the axis of the fourth roll is applied to the fourth tension roll 11. A driver (also not shown in detail) is also provided for the fifth tension roll 12, by means of which torque about the axis of the fifth roll is applied to the fifth tension roll 12.

[0127] The first tension roll 8 and the sixth tension roll 13 are implemented without a driver.

[0128] exist Figure 2 In the embodiment, the front tensioning roller group 3 has

[0129] • The first tension roll 14 having the first roll axis,

[0130] • The second tension roll 15, which has a second roll axis,

[0131] • The third tension roll 16, which has a third roll axis,

[0132] • The fourth tensioning roll 17 has a fourth roll axis.

[0133] A driver (not shown in detail) is provided for the second tension roller 15, by means of which torque about the axis of the second roller is applied to the second tension roller 15. A driver (also not shown in detail) is also provided for the third tension roller 16, by means of which torque about the axis of the third roller is applied to the third tension roller 16. A driver (also not shown in detail) is also provided for the fourth tension roller 17, by means of which torque about the axis of the fourth roller is applied to the fourth tension roller 17. A driver (also not shown in detail) is also provided for the first tension roller 14, by means of which torque about the axis of the first roller is applied to the first tension roller 14.

[0134] Figure 3 The force applied to the measuring roller by a metal strip under tension, partially wound around it, is illustrated. A quartz force sensor arranged in a recess within the measuring roller generates an electric charge. The charge is proportional to the force applied to the quartz.

[0135] The strip length deviation, generally expressed as strip flatness, typically measured in I-Units, can be calculated based on the following relationship:

[0136] Local tensile stress in strip section i

[0137]

[0138] where,

[0139] F_R,i = Local radial force (sensor force) in N

[0140] r_Roll = Radius of measuring roll

[0141] A_Sensor = Area of sensor or area of cover plate on sensor in contact with strip

[0142] d = Strip thickness.

[0143] The strip section deviation from the strip section with the maximum tensile stress:

[0144]

[0145] where,

[0146]

[0147] Local strip length deviation (flatness):

[0148]

[0149] where,

[0150] E = E modulus.

[0151] Example:

[0152] FR,i = 500 N

[0153] r_Roll = 300 mm

[0154] A_Sensor = 707 mm 2

[0155] d = 0.5 mm

[0156]

[0157]

[0158]

[0159] E = 206 GPa

[0160] ΔL / Li = 27.1 μm / m = 2.71 I-Units.

Claims

1. A tension roll assembly (3, 4) for a straightening device (1) for straightening strip (2) or for a leveling device for finishing strip, wherein, The tensioning roller group (3, 4) has • The first tensioning roll (8) with the first roll axis and • At least one second tension roll (9) having a second roll axis, The first tension roller (8) is a flatness measuring roller, which has a force sensor for measuring the radial force applied to the circumferential surface of the flatness measuring roller, and A driver is provided for the second tension roller (9), by means of which torque about the axis of the second roller can be applied to the second tension roller (9). Its features are, The first tension roller (8) is implemented without a driver.

2. The tensioning roller assembly (3, 4) according to claim 1, characterized in that, It includes a third tension roll (10) with a third roller axis and a fourth tension roll (11) with a fourth roller axis, wherein, a. A driver is provided for the third tension roller (10), by means of which torque about the axis of the third roller can be applied to the third tension roller (10). and / or b. A driver is provided for the fourth tension roller (11), by means of which torque about the axis of the fourth roller is applied to the fourth tension roller (11).

3. The tensioning roller assembly (3, 4) according to claim 2, characterized in that, It includes a fifth tension roll (12) having a fifth roller axis, wherein a driver is provided for the fifth tension roll (12) by means of which torque about the fifth roller axis can be applied to the fifth tension roll (12).

4. The tensioning roller assembly (3, 4) according to any one of claims 1 to 3, characterized in that, The flatness measuring roller has an axial hole extending parallel to the axis of the first roller, and the force sensor is arranged in the axial hole.

5. The tensioning roller assembly (3, 4) according to any one of claims 1 to 3, characterized in that, The flatness measuring roller has a surface coating.

6. The tensioning roller assembly (3, 4) according to any one of claims 1 to 3, characterized in that, The strip (2) is guided via the first tension roller (8) and via the second tension roller (9), and the strip (2) is wound around the first tension roller (8) with a contact angle of at least 90° and / or the strip (2) is wound around the second tension roller (9) with a contact angle of at least 90°.

7. A straightening device (1) for straightening a strip (2), the straightening device (1) having a. The front tensioning roller group (3), b. The rear tensioning roller assembly (4), c. A tension zone provided between the front tension roller group (3) and the rear tension roller group (4) and / or a bending frame (5) provided between the front tension roller group (3) and the rear tension roller group (4), Its features are, • The front tensioning roller assembly (3) is the tensioning roller assembly according to any one of claims 1 to 6. and / or • The rear tensioning roller group (4) is the tensioning roller group according to any one of claims 1 to 6.

8. The straightening device (1) according to claim 7, characterized in that, a. The rear tension roller group (4) is the tension roller group according to any one of claims 1 to 6, and the first tension roller (8) is the tension roller when the strip (2) first travels onto the tension roller group. and / or b. The front tensioning roller group (3) is a tensioning roller group according to any one of claims 1 to 6 and the first tensioning roller (8) is the tensioning roller when the strip (2) last leaves the tensioning roller group.

9. A leveling device for finishing rolled strip (2), said leveling device having a. The front tensioning roller group (3), b. The rear tensioning roller assembly (4), c. A leveling frame is set between the front tension roller group (3) and the rear tension roller group (4). Its features are, • The front tensioning roller assembly (3) is the tensioning roller assembly according to any one of claims 1 to 6. and / or • The rear tensioning roller group (4) is the tensioning roller group according to any one of claims 1 to 6.

10. A method for operating the straightening device (1) according to claim 7 or 8, wherein, The straightening device (1) has a bending frame (5) including a bendable roller and a control device, characterized in that the control device performs control intervention on at least one actuator of the straightening device based on the measurement results of a force sensor.

11. A method for operating the leveling equipment according to claim 9, wherein, The leveling equipment has settable rollers and a control device, characterized in that the control device performs control intervention on at least one actuator of the leveling equipment based on the measurement results of a force sensor.

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