WO2018167029A1 - Method for operating a roller straightener, and roller straightener - Google Patents

Abstract

The invention relates to a method for operating a roller straightener (1), which has a number of upper straightening rolls (2, 3, 4, 5) and a number of lower straightening rolls (6, 7, 8, 9), wherein a flat metal material (10) to be straightened is guided in a conveying direction (F) between the straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) and is straightened in the process. In order to improve the result of the straightening operation and specifically to achieve a greater degree of planarity, the invention provides for the method to have the following steps of: a) determining individual parameters of the flat material (10) to be straightened and specifying same to a computer system (11); b) carrying out a simulation calculation using a technological setting model stored in the computer system (11) on the basis of the individual parameters and defining a straightening strategy from the calculated data; c) carrying out the straightening operation in the roller straightener (1) using the defined straightening strategy as a basis. The invention further relates to a roller straightener.

Description

 Method for operating a roller leveler and roller leveler

The invention relates to a method for operating a roller leveler, which has a number of upper straightening rollers and a number of lower straightening rollers, wherein between the straightening rollers to be straightened metallic flat material, in particular a steel strip, guided in a conveying direction and this is directed. Furthermore, the invention relates to a roller leveler.

A method of the type mentioned and a corresponding roller leveler are known from EP 0 551 658 B1. In this solution, it is provided that individual straightening rollers are targeted to realize the required position of the rollers for the straightening process. In the solution described here, the maximum hyperextension is realized on only one straightening roller. Not all roles are involved in the straightening process, but only a selection thereof, there are various roles held in reserve.

A similar solution is disclosed in US 2013/0327109 A1. Here, the individual straightening rollers are driven by a common drive.

Another solution is described in EP 2 988 885 A1, wherein it is again provided that a group drive is provided for the common drive of the straightening rollers. This solution seeks to provide change cassettes for different straightening tasks, which are completely replaced as complete modules, so that cassettes can be kept with large roll diameters and cassettes with small roll diameters. The previously known standard directional strategy directs the necessary hyperextension, which leads to plasticization, only at the first two straightening rollers in the to be straightened workpiece. Subsequently, the hyperextension is steadily withdrawn to obtain a flat workpiece. Thus, the maximum possible plasticization is only entered from one side into the material, if only the first two straightening rollers bring the maximum hyperextension. Consequently, the introduction of a defined state of stress, in particular a voltage profile, with the previously known solutions only partially possible.

Particularly in the treatment of complex or even superimposed flatness errors, the previously known solutions provide only qualitatively unsatisfactory straightening results or a relatively large number of roughing passes are required in order to achieve a satisfactory result.

The invention is therefore based on the invention, a method of the type mentioned in such a way that even with complex flatness errors with a few punctures a flat material with a high degree of flatness or flatness can be produced.

The solution to this problem by the invention is characterized in that the method comprises the steps:

Determining individual parameters of the sheet to be straightened and providing it to a computing system; b) carrying out a simulation calculation on the basis of the individual parameters and determining a straightening strategy on the basis of the calculated data using a technological setting model stored in the computing system; c) Execution of the straightening process in the roller straightening machine on the basis of the defined straightening strategy. The determination of the individual parameters according to step a) above can include measuring unevenness of the flat material. It may also include (additive or alternative) an inspection of the sheet by an operator of the roll leveler. Furthermore, it may include detecting material data of the sheet. Furthermore, it can be provided that the determination comprises a definition of properties of the flat material after the straightening process, in particular a target tension profile in the flat material after the straightening process. The execution of the straightening process according to the above step c) may comprise a defined setting of the leveling rolls.

The straightening strategy according to the above step b) may include straightening the sheet with a plurality of roughing passes.

The straightening strategy can also be determined on the basis of a straightening process in which a maximum overstretching is introduced when straightening in the flat material as a result of the application of the straightening rolls, wherein the maximum overstretching is introduced by at least two adjoining straightening rolls following one another in the conveying direction.

The maximum hyperextension can be introduced through the first straightening roller and the adjacent straightening roller following in the conveying direction. The maximum hyperextension can also be introduced by the first straightening roller, the adjacent straightening roller following in the conveying direction and the adjacent straightening roller which continues in the conveying direction.

The maximum hyperextension can also be achieved by the first straightening roller, the adjacent straightening roller following in the conveying direction, which continues in the conveying direction following adjacent straightening roller and the next adjacent straightening roller in the conveying direction are introduced.

Preferably, all straightening rollers are brought by means of a separate Anstellelements in a predetermined individual delivery position.

Furthermore, it can be provided that all straightening rollers are acted upon by means of an individual rotary drive with a defined torque and / or driven with an individual rotational speed.

The adjusting elements and / or the rotary drives of all straightening rollers are actuated by a control or regulating device.

The proposed roller leveler, which has a number of upper straightening rollers and a number lower straightening rollers, wherein between the straightening rollers to be straightened metallic flat material in a conveying direction and this can be directed, is characterized according to the invention in that all straightening rollers an individual Anstellelement and a have individual rotary drive, with which all straightening rollers can be made and rotated independently.

The proposed procedure therefore depends on the consideration, in the implementation of the straightening process, first of all to determine relevant data relating to the good to be straightened and to read it into the machine control system or to enter it. Then the determination of a straightening strategy for the material to be straightened takes place. Finally, the straightening process is carried out by employing machine functionalities for carrying out the straightening process in accordance with the determined straightening strategy. The straightening strategy is determined or calculated by a technological adjustment model. The determined or measured material data of the material to be straightened is, in particular, the type of alloying of the material; The thickness and the strength of the material are to be understood by this. Preferably, the material is steel mesh or tapes. It is also possible to record and input error types or error types that have been determined or determined by measurement or testing by a person. The reading of the data set can be based on theoretical calculation or, as mentioned, by measurements or manual inputs. The data set may include target specifications for the state of the item to be straightened after straightening. In this case, a target voltage profile as well as previous and / or subsequent processing steps of the material can be taken into account.

The determination of the straightening strategy can be carried out on the basis of the entered error types. In this case, the straightening strategy can be calculated separately or together for only one straightening process or even for several straightening stitches. The directional strategy of a single asset to be directed can vary between two directives; It can take into account previous and subsequent processing steps. If necessary, the straightening strategy can also be changed by the operating personnel.

When straightening the metallic flat material, the use of an even number of maximum hyperextensions has proven itself. Said maximum overexpansion can preferably take place on the second and third straightening rollers, and additionally also on the fourth straightening roller. The topic of hyperextension as such is known and explained in the above-mentioned EP 0 551 658 B1, which is expressly incorporated herein by reference.

In that regard, it is envisaged that several straightening rollers in a row each realize the maximum hyperextension. The adjustment of the straightening rollers takes place so that the voltage peaks over the thickness of the flat material to be straightened as possible have a constant height.

The mentioned machine functionalities are mainly concerned with the main position of the rollers, their tilting and pivoting and the bending, expansion and compression compensation.

In particular, the single straightening roller adjustment is provided as well as an individual drive of each straightening roller (in terms of their driving torque and speeds). The straightening rollers are accordingly preferably individually adjustable and individually driven.

With regard to the aforementioned adjustment model, it should be mentioned that this first consists of a material database and of the necessary inputs in order to carry out a numerical simulation of the deformation behavior of the metallic flat material under the influence of the straightening rollers. For such a simulation only a short time of less than 1 second is needed. The proposed roller straightening machine is characterized in that a control device for individual control of the existing machine functions is provided, which sets the functionalities based on a previously determined straightening strategy. Accordingly, in the context of the straightening strategy, in particular the number and straightening roll sequence is allowed or determined, which permits overstretching, in particular on the basis of further data records that go beyond the material data, such as defect type and production properties. The guideline strategy is ultimately a combination of specifications for the employment of machine functionalities, which is based on the calculation of the based on technological model. In the case of several required straight passes and / or complex and / or superimposed errors, the straightening strategy for the respective required straight passes of a single workpiece may differ from one another and only lead to the optimum straightening result in total.

With regard to the machine functionality, it should be noted that this includes the actuators for setting and / or regulating Umformparametern, in particular the speed and torque of the individual straightening rollers, the immersion depth of the individual straightening rollers, the contact force of the individual straightening rollers, the position specifications (panning / bending) the individual straightening rollers and the main job of all straightening rollers is to call.

With regard to the flatness defects (flatness defects) of the flat material, these can be distinguished as follows:

Elemental (uniaxial) flatness defects are the coil set (different lengths of fiber on the top of the belt or underside of the belt), the crossbow (different lengths of fiber in the transverse direction (top / bottom)), the twist (different fiber lengths in the longitudinal direction (top / bottom) unevenly over the bandwidth).

Complex (multiaxial) flatness errors are edge waves (different fiber lengths from the belt edge to the belt center), center buckles (different fiber lengths from the belt center to the belt edge), quarter buckles (different fiber lengths in the longitudinal direction (stripes)) and short wave or long wave appearance of the waves.

The present invention thus relies centrally on a technological adjustment model which essentially consists of a material database and which, by means of further inputs, forms a complex calculation of the Can make straightening. Especially the consideration of the further inputs leads to a substantial improvement of the straightening process.

Other inputs in this sense are primarily information about the nature and location of the errors to be corrected. Knowing the errors in particular, the technological model can make the calculations that lead to an effective and tailor-made alignment strategy. It may be that for the correction of errors several top stitches, ie passes through the leveler, are necessary, in which the errors are eliminated altogether. It may well happen that in a straightening process (righting stitch), an error is corrected, which leads to an amplification of another error, which is then compensated in another topping stitch. It is not inevitable that all errors are rectified evenly and together in one go-to-stitch. The straightening strategy takes into account the overall result to be achieved and defines the necessary steps.

In addition, the calculation of the technological adjustment model can be extended by the consideration of previous production steps. If residual voltage distributions of previous processing steps are known, these are also included in the technological calculations. This is especially true for cooling, where also in the workpiece surface (edges to center) different distributions are taken into account. These result from physically necessary variable temperature distribution and thus different structural components resulting from many steel brands. The information about this can be done via any data transfer, such. B. by means of a coupling with a cooling model.

The same applies to the provision of data from previous rolling programs, which can often provide microstructural constituents (eg austenite composition), particle size distributions and dislocation densities. The information can also take place here via any data transfer, such. B. a coupling to a rolling model.

The residual stress and strain distributions known from previous process steps are used to establish the minimum required plasticization in the following straight stitch.

The technological adjustment model can also incorporate specifications that take into account the following processing steps. If the straightening process another processing step, eg. B. welding or bending, should follow, it can be set to maintain the flatness in these subsequent steps, the necessary voltage profiles in the workpiece targeted by specifying the straightening strategy in the individual roughing passes. Thus, an individual calculation is made for each workpiece, which not only based on the pure material specifications (such as alloy, thickness, width, general strength), but much more.

The straightening strategy converts the calculations generated from the technological setting model into specifications for the implementation of the respective topping stitch, by creating a combination of specifications for setting up machine functionalities. The relevant machine functions are (as mentioned above) the main job for all straightening rollers in common (including tilting and swiveling), the single straightening roller adjustment (for bending-expansion and compression compensation), the determination of the drive torques of each straightening roller and the straightening roller bending.

In particular, the single straightening roller adjustment can adjust the individual immersion depth and thus provide a targeted straightening strategy within a roughing pass. The single drive of each straightening roller allows the individual provision of torque for the straightening process. Aspects of the straightening strategies are:

The maximum hyperextension is realized (as in the prior art) on the first straightening roller.

The maximum hyperextension is realized on more than one straightening roller and preferably set an even number of maximum hyperextensions; Thus, the number of plastic strains and compressions for both surfaces of the workpiece is the same. The remaining guide triangles are used to minimize the residual voltage level.

There is a hiring of straightening rollers such that the voltage peaks on the sheet thickness have a constant height.

There is a hiring of straightening rollers such that the voltage peaks from the center of the workpiece thickness decrease towards the surface.

There is a hiring of the first straightening rollers so that the maximum hyperextension on the first and second straightening roller is achieved (or continue on a subsequent straightening roller).

Alternatively, multiple rollers can be used to build the maximum hyperextension. This reduces at the same value of the maximum hyperextension (or maximum value of the plasticization) the required employment (intermeshing) of the roles. The otherwise required extreme jobs of the first rolls in the direction of the topping are drastically reduced with this method: setting the first straightening rollers so that the maximum overstretching is achieved at the second and third straightening roller. Adjusting the first straightening rollers so that the maximum hyperextension is achieved at the first, the second and the third straightening roller. Adjusting the first straightening rollers so that the maximum hyperextension is achieved at the first, the second, the third and the fourth straightening roller.

Adjusting the first straightening rollers so that the maximum hyperextension is achieved at the second, the third and the fourth straightening roller.

Adjusting the first straightening rollers so that the maximum hyperextension is achieved at the third and fourth straightening roller.

It can also be a smoothing pass (special job for straightening a thick sheet) done in which is switched after straightening to reduced number of rolls or to a straightening with maximum straightening roll number.

With the appropriate straightening strategy, the number of necessary punctures can be reduced.

With the appropriate straightening strategy, the achievable flatness can continue to be tailor-made for every workpiece, even with complex flatness errors. The introduction of the maximum hyperextension can be carried out selectively on both sides of the workpiece or specifically on the workpiece top or on the underside of the workpiece.

In the drawing, an embodiment of the invention is shown. Fig. 1 shows schematically a roller leveler in which a metallic strip is directed,

Fig. 2 schematically shows the roll straightening machine, the control of which is illustrated by a block diagram, and schematically shows the forming ratios of a metallic strip passing through the roll straightening machine. FIG. 1 schematically shows a roller leveling machine 1 which has a plurality of upper straightening rollers and a plurality of lower straightening rollers. The upper straightening rollers follow one another in the conveying direction F, namely the straightening rollers 2, 3, 4 and 5. The lower straightening rollers are offset in the conveying direction F to the upper straightening rollers and equally follow one another in the conveying direction, namely the straightening rollers 6, 7, 8 and 9. A sheet 10 to be straightened is conveyed by the roller straightening machine 1 when the straightening rollers are fed to the sheet 10 and rotated. The drive of the straightening rollers is shown schematically in the form of arrows (A). Also not visible is accordingly that for each of the straightening rollers 2 to 9, a separate drive is present, which operates independently of the drives of the other straightening rollers and for each of the straightening rollers specifies an individual torque for driving the roller or an individual speed. Similarly, each of the straightening rollers 2 to 9 on a Anstellelement, wherein those Anstellelemente are denoted by 12, which act on the upper straightening rollers 2, 2, 3 and 5, and those Anstellelemente are denoted by 13, the lower straightening rollers 6, 7, 8 and 9 apply. It can be seen in FIG. 3 how preferably the loading of the flat material 10 takes place through the leveling rolls in order to direct it. In this It can be seen that the first upper straightening rollers 2 following in the conveying direction F are delivered in such a way that the flat material 10 to be straightened is plastically deformed. Below the straightening rollers 2, a region P _{s of} the plastic compression on the upper side of the flat material 10 is marked and a region P _{D of} the plastic strain on the underside of the flat material 10. In the region of the neutral fiber of the flat material 10 is an elastic region E.

The following in the conveying direction F lower straightening rollers 7 is delivered so that here on the flat material 10 an equally large forming force is exerted, so that in turn arise areas of plastic compression P _s or the plastic strain P _D , but now on each other sides of the flat material 10. The concrete procedure for straightening the flat material 10 results from FIG. 2.

It can be seen here that flatness 10 of the flat material 10 is detected by a suitable sensor system 15 before the straightening process, and the measured values are made available in a region 16 as read-in or analyzed data. Said area 16 still receives additional information through a data record 14, which contains data about the material and geometry of the flat material 10 to be straightened. Thus, comprehensive information is available in area 16, which provides information on the type, geometry and degree of flatness of the flat material 10.

These data are made available to a computing system 11 in which a technological setting model 17 is stored. The positioning model 17 is a mechanical replacement model for the flat material 10 to be straightened, in which the geometry is calculated by means of numerical simulation, which results when the straightening rolls are subjected to the straightening process results. Such simulation systems for the deformations of the material are known in the art as such and therefore need not be described in detail here. One of the possibilities in question is the calculation of the geometry and the stresses in the flat material 10 after completion of the straightening process by means of finite elements.

By appropriate calculation can thus be determined a straightening strategy, which is made available after performing the simulation calculation in the area 18. This straightening strategy includes requirements for the execution of the straightening process for all intended stabs. This also gives the required data for the positioning of the straightening rollers and the actuation of the drives of the same.

From this, the data for setting the straightening rollers are then generated in the area 19, which also include the corresponding values for the rotary drive of the rollers (A). These data are then passed on to the adjusting elements 12, 13, which is shown schematically in Figure 2.

Thus, in summary, the roller leveler 1 comprises a number of (1 to n) straightening rollers 2 to 9 for straightening the workpiece 10. The errors (flatness error) of the workpiece are determined before straightening. This determination can be made by measuring immediately before the straightening process, but the error detection can also be done in other places before. A dataset including geometrical dimensions of the workpiece, material data of the workpiece, but also information on the nominal state of the workpiece, taking into account the entire straightening process, including all the planned finishing stitches belonging to the flat material (workpiece) 10 (possibly including manual inputs and possibly also data of the system state) additionally available. The data of the flatness errors (measured by means of the sensor system 15) and the general data set 14 are read in and analyzed and formatted as required, so that the technological setting model 17 can generate the calculations for the straightening strategy. The result of the calculation is the straightening strategy 18, which can, but does not have to, be distributed over various straight stitches. The determination of the necessary number of corrective stitches is also part of the straightening strategy.

To implement the guideline strategy, the setting of machine functionalities is necessary for each associated roughing pass. In particular, the individual employment and the corresponding individual drive (for adjusting the individual torque) of the straightening rollers 2 to 9 provide the flexibility which allows the adjustment of different straightening strategies and thus an optimal treatment of the sheet 10. In particular, the setting of an even number of hyperextensions (s Figure 3) and the selection of straightening rollers that generate the hyperextension, can be done so.

The machine functions are very diverse; they are shown only schematically in FIG. 2 (as an effect on the positioning elements 12, 13). This generally means that all functionalities of the employment are taken into account.

LIST OF REFERENCE NUMBERS

1 roller straightening machine

 2 upper straightening roller

 3 upper straightening roller

 4 upper straightening roller

 5 upper straightening roller

6 lower straightening roller

 7 lower straightening roller

 8 lower straightening roller

 9 lower straightening roller

 10 flat material to be straightened

1 1 computing system

 12 positioning element

 13 setting element

 14 record

 15 Sensor for recording flatness errors 16 read-in data / analyzed data

17 technological adjustment model

 18 identified straightening strategy for all punctures

19 Data for adjusting straightening rollers F Flow direction

P _s range of plastic compression

P _D range of plastic strain

 E elastic range

A drive

Claims

claims: 1 . Method for operating a roller leveling machine (1) comprising a number of upper straightening rollers (2, 3, 4, 5) and a number of lower straightening rollers (6, 7, 8, 9), wherein between the straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) a metallic flat material (10) to be straightened is guided in a conveying direction (F) and thereby directed, characterized in that the method comprises the steps of: a) determining individual parameters of the to be straightened Flat material (10) and pretending the same to a computing system (1 1); b) performing a simulation calculation on the basis of the individual parameters and determining a straightening strategy on the basis of the calculated data using a technological setting model stored in the computing system (11); c) carrying out the straightening process in the roller straightening machine (1) on the basis of the specified straightening strategy. 2. The method according to claim 1, characterized in that the determination of the individual parameters according to step a) of claim 1 comprises a measurement of unevenness of the flat material (10). A method according to claim 1, characterized in that the determination of the individual parameters according to step a) of claim 1 comprises a visual inspection of the sheet (10) by an operator of the roller leveler (1). Method according to one of claims 1 to 3, characterized in that the determination of the individual parameters according to step a) of claim 1 comprises a determination of material data of the sheet (10). Method according to one of claims 1 to 4, characterized in that the determination of the individual parameters according to step a) of claim 1 defining a properties of the flat material (10) after the straightening process, in particular a target voltage profile in the flat material (10) after straightening , Method according to one of claims 1 to 5, characterized in that the implementation of the straightening process according to step c) of claim 1 comprises a defined setting of the leveling rolls (2, 3, 4, 5, 6, 7, 8, 9). Method according to one of claims 1 to 6, characterized in that the straightening strategy according to step b) of claim 1 comprises straightening the flat material (10) with a plurality of roughing passes. Method according to one of claims 1 to 7, characterized in that the straightening strategy according to step b) of claim 1 is determined on the basis of a straightening process in which when straightening in the flat material (10). as a result of the application of the straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) a maximum overstretching is introduced, the maximum hyperextension being determined by at least two adjacent straightening rollers (2, 3) following one another in the conveying direction (F). 3, 4, 5, 6 7, 8, 9) is introduced. 9. The method according to claim 8, characterized in that the maximum hyperextension by the first straightening roller (6) and in the conveying direction (F) following adjacent straightening roller (2) is introduced. A method according to claim 8, characterized in that the maximum hyperextension by the first straightening roller (6), in the conveying direction (F) following adjacent straightening roller (2) and in the conveying direction further adjacent straightening roller (7) is introduced. A method according to claim 8, characterized in that the maximum hyperextension by the first straightening roller (6), in the conveying direction (F) following adjacent straightening roller (2), in the conveying direction further adjacent straightening roller (7) and the further adjacent in the conveying direction adjacent Straightening roller (3) is introduced. Method according to one of claims 1 to 1 1, characterized in that all straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) are brought by means of a separate Anstellelements (12, 13) in a predetermined individual feed position. 3. The method according to any one of claims 1 to 12, characterized in that all straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) acted upon by means of an individual rotary drive with a defined torque and / or with an individual rotational speed are driven. 4. The method according to claim 12 or 13, characterized in that the adjusting elements (12, 13) and / or the rotary drives of all straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) by a control or regulating device be operated. 5. roll straightening machine (1) having a number of upper straightening rolls (2, 3, 4, 5) and a number of lower straightening rolls (6, 7, 8, 9), wherein between the straightening rolls (2, 3, 4, 5, 6, 7, 8, 9) to be straightened metallic flat material (10), in particular a steel strip, guided in a conveying direction (F) and this can be directed to carry out the method according to one of claims 1 to 14, characterized in that all straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) have an individual positioning element (12, 13) and an individual rotary drive with which all straightening rollers (2, 3, 4, 5, 6, 7, 8, 9) can be made and rotated independently of each other.