STRETCHING-BENDING-STRAIGHTENING SYSTEM AND METHOD OF THE ACTUATION THEREOF

Abstract

In a stretching-bending-straightening system and a method for the actuation thereof, material in strip form is fed to a high-tension region (50) and a low-tension region (52), wherein the low-tension region (52) is arranged downstream of the high-tension region (50). A bending-straightening unit is arranged in the high-tension region (50). A measuring system determines first measured values in the high-tension region (50). A controller (C) is intended and suitable for determining a deviation of the first measured values from a setpoint value of the bending-straightening result and for determining at least one manipulated variable for the bending-straightening unit in dependence on the determined deviation within a first closed control loop. By additionally providing at least one measuring system for determining second measured values in the low-tension region, by having a controller (C) intended and suitable for determining a deviation of the second measured values from the setpoint value of the bending-straightening result and for determining the at least one manipulated variable in dependence on the determined deviation within a second closed control loop, and by providing selecting means that are intended and suitable for selecting the first or second closed control loop for reducing the deviation of the first and/or second measured values from the predetermined or predeterminable setpoint value, a stretching-bending-straightening system and a method for the actuation thereof are designed in such a way that the quality of the strips processed thereby is increased.

Claims

1.-16. (canceled)

17. A stretching-bending-straightening system, having a feed means for feeding a material in strip form in a movement direction into a high-tension region and a low-tension region, wherein the low-tension region is arranged downstream of the high-tension region in the movement direction, a bending-straightening apparatus, which is situated in the high-tension region, at least one measuring system for determining first measured values in the high-tension region, a controller, which is intended and suitable for determining a deviation of the first measured values from a predefined or predefinable desired value of the bending-straightening result and for determining at least one manipulated variable for the bending-straightening apparatus depending on the determined deviation within a first closed control loop, an adjustment means for influencing the manipulated variable, wherein there is provided in addition at least one measuring system for determining second measured values in the low-tension region, wherein a controller is intended and suitable for determining a deviation of the second measured values from the predefined or predefinable desired value of the bending-straightening result and for determining the at least one manipulated variable depending on the determined deviation within a second closed control loop, and wherein selection means are provided and are intended and suitable for selecting the first closed control loop or the second closed control loop in order to reduce the deviation of at least one of the first or second measured values from the predefined or predefinable desired value.

18. A stretching-bending-straightening system in accordance with claim 17, wherein the controller is one single controller, which is intended and suitable for determining simultaneously the deviation of the first and the second measured values from the predefined or predefinable desired value, and in that the selection means are intended and suitable for selecting the first or the second closed control loop alternatively.

19. A stretching-bending-straightening system in accordance with claim 17, wherein at least one analysis unit for analysing at least one of the first or the second measured values is provided, and wherein the selection means are intended and suitable for selecting the first or the second closed control loop depending on the analysis.

20. A stretching-bending-straightening system in accordance with claim 17, wherein display means for displaying the first and second measured values are provided.

21. A stretching-bending-straightening system in accordance with claim 17, wherein the selection means are provided for manual selection by an operator.

22. A stretching-bending-straightening system in accordance with claim 17, wherein the at least one measuring system for determining the first measured values in the high-tension region is formed by a measuring roller arranged after the bending-straightening apparatus.

23. A stretching-bending-straightening system in accordance with claim 22, wherein a roller of a tension S-block is replaced by the measuring roller having sensors deployed on its circumference, the running surface of the measuring roller being covered by a resilient coating.

24. A stretching-bending-straightening system in accordance with claim 17, wherein the at least one measuring system for determining the second measured values is formed by a measuring roller arranged after the bending-straightening apparatus and after the tension S-block in the low-tension region).

25. A stretching-bending-straightening system in accordance with claim 24, wherein the measuring roller has adjacently arranged measuring segments having at least one sensor.

26. A stretching-bending-straightening system in accordance with claim 25, wherein the at least one sensor comprises two force sensors.

27. A stretching-bending-straightening system in accordance with claim 17, wherein storage means for storing the operating parameters adjusted as a result of the first or second closed control loop are provided, and wherein a data bank is provided, which is intended and suitable for storing these operating parameters together with data regarding the material processed by these operating parameters.

28. A method for operating a stretching-bending-straightening system, said method comprising the steps: feeding a material in strip form in a movement direction into a high-tension region and a low-tension region, wherein a bending-straightening apparatus is arranged in the high-tension region, and wherein the low-tension region is arranged downstream of the high-tension region in the movement direction, determining first measured values in the high-tension region, determining a deviation of the first measured values from a predefined or predefinable desired value of the bending-straightening result, determining at least one manipulated variable for the bending-straightening apparatus depending on the determined deviation within a closed control loop, determining second measured values in the low-tension region, determining a deviation of the second measured values from the predefined or predefinable desired value of the bending-straightening result, determining the at least one manipulated variable depending on the determined deviation within a second closed control loop, selecting the first or the second closed control loop in order to reduce the deviation of at least one of the first or second measured values from the predefined or predefinable desired value.

29. A method in accordance with claim 28, wherein the deviation of the first and the second measured values from the predefined or predefinable desired value is determined simultaneously by means of one single controller, and wherein the first closed control loop or the second closed control loop is selected alternatively.

30. A method in accordance with claim 28, wherein the first and the second measured values are analyzed on the basis of predetermined criteria in view of achieving a bending-straightening result, and wherein the first or the second closed control loop is selected depending on the analysis.

31. A method in accordance with claim 28, wherein the first and second measured values are displayed to an operator simultaneously.

32. A method in accordance with claim 28, wherein the first closed control loop or the second closed control loop is selectable manually by an operator.

33. A method in accordance with claim 28, wherein the method is operated initially on the basis of the first measured values from the high-tension region in the first closed control loop, until the straightened material in strip form reaches the measuring roller in the low-tension region, and wherein a switch is then made to the second closed control loop in the low-tension region.

34. A method in accordance with claim 28, including storing, in a data bank, operating parameters already determined in advance during operation of the stretching bending-straightening system, jointly with data regarding the material processed with said operating parameters, and using the stored data for the processing of comparable materials.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0029] The invention will be explained in greater detail hereinafter with reference to an exemplary embodiment of the invention illustrated in the drawings, in which:

[0030] FIG. 1 shows a schematic illustration of the arrangement according to the invention of the components of the invention;

[0031] FIG. 2 shows a schematic course of the method according to the invention;

[0032] FIG. 3 shows a schematic course of a stretching-bending-straightening system according to the prior art;

[0033] FIG. 4a, 4b show a three-dimensional illustration of edge undulations and associated fiber lengths on a material to be processed;

[0034] FIGS. 5a to 5d show illustrations of middle undulations, edge undulations, edge undulations on one side, and a combination of edge and middle undulations on a material to be processed;

[0035] FIG. 6 shows a schematic illustration of a straightening process according to the prior art;

[0036] FIG. 7a, 7b show an end-side view and a side view of straightening rollers and support rollers in a straightening process according to FIG. 6;

[0037] FIG. 8 shows a schematic illustration of an unflatness measuring system for the low-tension region according to the prior art;

[0038] FIG. 9 shows a schematic illustration of a flatness measuring system according to DE 10 2004 043 150 A1.

DETAILED DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS

[0039] The invention will now be explained in greater detail with reference to the accompanying drawings. The exemplary embodiments, however, are merely examples not intended to limit the inventive concept to a certain arrangement. Before the invention is described in detail, it is noted that the invention is not limited to the various components of the device or the various method steps, since these components and methods may vary. The terms used here are merely intended to describe particular embodiments and are not used in a limiting sense. In addition, if the singular or an indefinite article are used in the description or in the claims, this also refers to the plurality of these elements, provided the overall context does not clearly indicate otherwise.

[0040] In accordance with the invention, both measuring systems for the high-tension and low-tension regions are combined for the first time. This system is characterized preferably by the use of a single controller C, however a plurality of controllers may be used in principle. This, preferably one, controller C is able to analyze the flatness measured values of the measuring roller 40 in the high-tension region 50 and of the measuring roller 36 in the low-tension region 52. The supports of the straightening movement are adjusted on the basis of these values.

[0041] The analysis units 34 of the two measuring units are connected to the controller. This receives the flatness values of the two units and, using the measured values of the active measuring unit, calculates the optimal parameters for the straightening process. The system operator preferably determines which of the two measuring units should be used as a basis for controlling the straightening process. The operator is therefore able to use the measuring unit that is better suited according to the requirements and material and may also change the measuring unit during a process. So as to be able to compare the two units with one another for the process currently underway, it is possible to visualize the flatness measured values. To this end, the measured values of the measuring roller 36 in the low-tension region and of the measuring roller 40 in the high-tension region 50 are displayed in graphic form and/or as numerical values, preferably at the same time on a display unit 46.

[0042] A more precise adaptation of the supports to the areas of unflatness of the strip is thus achieved by the system according to the invention. In addition it is now possible to use the system that is better suited according to material requirements, material alloy and/or material thickness, and thus to attain optimal straightening results.

[0043] In the case of very thin and soft materials, such as aluminum, it could be that areas of unflatness may not be clearly detected due to the high tension. This may be caused by the resilient properties of the strips. If the strip is stretched with the high tension to such an extent that it appears to be flat, areas of unflatness at this moment might not be measurable and might reappear after reduction of the tension as a result of the elastic recovery. In this case it would be possible to change the measuring system during the process and thus improve the process.

[0044] A further advantage is that the waste of materials with which better straightening results are attained with the measuring roller 36 in the low-tension region 52 may be permanently reduced. To this end the measuring roller 40 in the high-tension region 50 is firstly activated and is switched over to the measuring roller 36 in the low-tension region 52 after the dead space.

[0045] The measuring roller 40 in the high-tension region, by contrast, is suitable for example for high-strength materials. Since the strip is much stronger, the areas of unflatness are not falsified by the high tension. Thus, the measuring roller 40 in the high-tension region 50 may be used for this situation, and the advantage of the much shorter dead space also utilized.

[0046] Once the material 10 in strip form has been threaded in, the system may be started. The controller C initially operates with the values of the high-tension measuring roller 40, since the dead space thereof is much smaller. The dead space is understood here to mean the material length that is necessary, due to the control system from an adjustment means, i.e. the bending-straightening apparatus 26, to the measuring point, before a detected unflatness leads to an influencing of the detected unflatness as a result of a control intervention at the bending-straightening apparatus 26. The controller C adjusts the bending-straightening apparatus 26 in accordance with the calculated parameters so as to attain the optimal straightening result. Once the straightened strip has reached the low-tension measuring roller 36, the controller C automatically switches over from the high-tension measuring roller 40 to the low-tension roller 36 and controls the support rollers 32 of the bending-straightening apparatus with the measured values of the low-tension measuring roller 36, provided no other adjustment is specified by the operator by way of the input means 49 or by the stretching bending-straightening system, for example on the basis of results already made known to the movement earlier.

[0047] The system operator may at any time intervene manually by way of input means 49 and may adjust the controller C as needed. The operator may also use the input means 49 to input and specify process data. Furthermore, the system operator may create a data bank 44, in which parameters for the process may be stored, for example for specified materials or materials already straightened before on the system. The controller C may thus select the optimal measuring roller 36 or measuring roller 40 automatically in the case of repeated jobs.

[0048] Besides the data regarding processes already performed on the system, further data may also be stored in the data bank 44, for example an allocation of certain operating parameters to certain materials or also expert knowledge. Expert knowledge constitutes information relating to how an experienced operator would operate the stretching-bending-straightening system and with which parameters the operator would work in order to attain a good result. Further physical properties may also be specified here, such as the operating speed or temperature-dependent properties.

[0049] Since both the measuring roller 40 in the high-tension region 50 and the measuring roller 36 in the low-tension region 52 are engaged and display their measured values, it is possible to interpolate the measured values of the two measuring devices and to compare them with one another by the software. This is made possible for example by forming a mean value for each measuring device and determining this mean value with defined limits with an interval of 50 control cycles, for example. Depending on the result and analysis of the software, the controller C may then decide independently which measuring system is the more suitable one. This switchover may be implemented automatically, or a recommendation may be expressed to the system operator.

[0050] FIG. 2 shows schematically a method sequence. In the step 100, material 10 in strip form is fed to a high-tension region 50 and to a low-tension region 52. The material thus fed is measured in step 101 by means of a measuring device in the high-tension region, wherein flatness deviations are determined as first measured values. After the high-tension region the material in strip form passes into the low-tension region 52, and the flatness deviations are likewise measured there in step 102. This leads to the second measured values.

[0051] In step 103 the flatness deviations are compared with a desired value for the flatness deviations. If the flatness deviation is less than or equal to the desired value, the stretching bending-straightening system is operated with these operating parameters. If the desired value is not observed, a choice is made in step 104, preferably on the basis of predefined criteria, whether the result, and thus the flatness deviation, should be influenced with the control system in the high-tension region or in the low-tension region. Depending on which system is selected, the manipulated variable for the high-tension region 50 or the low-tension 52 is calculated either in step 105 or in step 106. The manipulated variable is then applied in step 107 to the bending-straightening apparatus 26, and the method then jumps back to step 101 and 102, so as to measure the flatness deviations in the high-tension region 50 or in the low-tension region 52. The method then starts again.

[0052] Information originating from a data bank 44, into which operating parameters from earlier processes, material characteristic values or also expert knowledge have been input, may also be applied for the selection of the control system in step 104 and the determination of the manipulated variable in steps 105 and 106.

[0053] It is self-evident that this description may be subject to a very wide range of modifications, alterations and adaptations which lie within the scope of equivalents to the accompanying claims.

LIST OF REFERENCE NUMERALS

[0054] 10 material in strip form [0055] 12 undulation [0056] 13 middle undulation [0057] 14 edge undulation [0058] 16 brake S-block [0059] 18 tension S-block [0060] 20 decoiler [0061] 22 measuring device [0062] 24 movement direction [0063] 26 bending-straightening apparatus [0064] 28 recoiler [0065] 30 straightening roller [0066] 32 support roller [0067] 34 analysis unit [0068] 36 measuring roller [0069] 36a measuring segment [0070] 38 position control unit [0071] 40 measuring roller in the high-tension region [0072] 42 dead space [0073] 44 data bank [0074] 46 display unit [0075] 48 selection means [0076] 49 input unit [0077] 50 high-tension region [0078] 52 low-tension region [0079] L.sub.ref reference length [0080] ΔL length difference [0081] C controller [0082] SPS memory-programmed control assembly [0083] 100 to 108 method steps