Method and computer program product for setting the bending of at least one straightening roller of a roller straightening machine

Abstract

In a method for setting bending of at least one straightening roller in a roller straightening machine, the straightening roller is supported by a plurality of supporting roller devices arranged beside one another in the axial direction, wherein each supporting roller device can be adjusted by an actuating device such that stresses are produced in the straightening roller. To control the actuating device, a control system is provided, by which the adjustment of the supporting roller device can be set manually. Limiting values (vMA, vMI) with respect to the stresses produced in the straightening roller are stored in the control system. In the event of adjustment of one of the supporting roller devices, maxima (MA) and minima (MI) of the stresses produced in the straightening roller are calculated and it is checked whether the maxima (MA) and minima (MI) lie within the limiting values (vMA, vMI).

Claims

1. A method for adjusting a roller straightening machine, comprising: arranging lower straightening rollers to be spaced apart from each other in a transport direction, lower supporting rollers situated under the lower straightening rollers, and actuating devices for adjusting the lower supporting rollers such that stresses are produced in the lower straightening rollers, arranging upper straightening rollers to be spaced apart from each other in the transport direction above the lower straightening rollers, and upper supporting rollers situated above the upper straightening rollers, adjusting and controlling the lower supporting rollers by the actuating devices such that stresses are produced in the lower straightening rollers, storing in a control system limiting values (vMA, vMI) with respect to the stresses produced in the lower straightening rollers, actuating the lower supporting rollers to obtain an actual stress curve showing a profile of stresses produced by the upper and lower straightening rollers under an elastic deformation resistance of the upper and lower straightening rollers, calculating an actual bending line from the actual stress curve under consideration of the elastic deformation resistance of the upper and lower straightening rollers, and running the lower supporting rollers within the limiting values (vMA, vMI), wherein, in an event of a change in an adjustment of one of the lower supporting rollers, maxima (MA) and minima (MI) of the stresses produced in the lower straightening rollers are calculated and it is checked whether the maxima (MA) and minima (MI) lie within the limiting values (vMA, vMI) and, if this is not the case, a further adjustment of at least one of the supporting rollers is changed automatically in accordance with a predefined algorism stored in the control system such that the stresses produced in the straightening rollers remain within the limiting values (vMA, vMI).

2. The method according to claim 1, wherein torsional stresses brought about by a drive of the upper and lower straightening rollers are superposed in order to calculate the stresses.

3. The method according to claim 1, wherein each of the actuating devices comprises two wedges displaceable relative to one another, on which a holding device receiving each of the lower supporting rollers is supported, and wherein a change to the adjustment is brought about by a displacement of at least one of the wedges relative to the holding device.

4. The method according to claim 1, wherein each of the lower straightening rollers is supported on the supporting rollers with two intermediate rollers arranged in between.

5. The method according to claim 1, wherein the lower supporting rollers include intermediate rollers disposed between the lower supporting rollers and the lower straightening rollers.

6. The method according to claim 1, wherein the maxima (MA) and minima (MI) of the actual stress curve are stored in the control system and are given for an adjustment of the actuating devices and/or a sheet metal guided between the upper and lower straightening rollers.

7. The method according to claim 1, wherein the lower straightening rollers have a cylindrical shape and are arranged perpendicular to the transport direction, and the upper straightening rollers have a cylindrical shape and are arranged perpendicular to the transport direction.

8. The method according to claim 1, wherein the lower straightening rollers are cambered by the actuating devices, while the upper straightening rollers are not cambered.

9. A computer program product for adjusting bending of at least one straightening roller of a roller straightening machine, comprising: computer instructions for carrying out the method of claim 1 stored on a computer-readable storage medium which, when executed, prompt the control system to carry out the computer instructions on the roller straightening machine.

Description

(1) Exemplary embodiments of the invention will be explained in greater detail hereinafter with reference to the drawings, in which:

(2) FIG. 1 shows a perspective view of a roller straightening machine,

(3) FIG. 2 shows a perspective view of a lower roller mill,

(4) FIG. 3 shows a schematic, partial sectional view of the roller straightening machine according to FIG. 1,

(5) FIG. 4 shows a perspective view of an actuating device,

(6) FIG. 5 shows the stress profile of an actual stress curve and of a bending line over a width of a straightening roller,

(7) FIG. 6 shows a schematic flow diagram of a computer program product,

(8) FIG. 7 shows a display for operating the computer program product according to FIG. 6, and

(9) FIGS. 8-1 to 8-13 show deviations of the equations for the equilibriums of moments, the stresses in the straightening roller, and for superposition of the torsional stress.

(10) The roller straightening machine shown in FIG. 1 has a lower roller mill 1 and an upper roller mill 2. Reference sign 3 denotes actuating drives by means of which lower straightening rollers (not shown), or rather straightening rollers of the lower roller mill 1 are adjustable. The arrow T denotes a transport direction of a sheet metal strip (not shown here) through a straightening gap formed between the lower mill 1 and the upper roller mill 2. The arrow A denotes an axial direction which runs parallel to the axes of the straightening rollers (not shown here). The arrow V denotes a vertical direction running perpendicularly to the transport direction T and to the axial direction A.

(11) FIG. 2 shows a schematic view of the lower roller mill 1. Reference sign 4 denotes supporting roller devices which extend in the transport direction T. Each of the supporting roller devices 4 has a holding device 5, on which a plurality of supporting rollers 6 are received in pairs one behind the other in the transport direction T. Reference sign 7 denotes a lower straightening roller or a straightening roller. For the sake of clarity, merely one straightening roller 7 is shown here. Intermediate rollers, which are arranged between the supporting rollers 6 and the straightening roller 7, have also been omitted.

(12) FIG. 3 shows a schematic sectional view through the lower roller mill 1 and the upper roller mill 2. The supporting rollers 6 received on the holding device 5 are movable in the lower roller mill 1 in the vertical direction V by means of an actuating device (not visible here). Reference sign 8 denotes intermediate rollers, which are supported on the supporting rollers 6. The lower straightening rollers 7 are in turn supported on the intermediate rollers 8.

(13) The upper roller mill 2 comprises upper straightening rollers 9, which are arranged in the transport direction T offset from the lower straightening rollers 7. The upper straightening rollers 9 are supported via further intermediate rollers 10 on further supporting rollers 11. In the present exemplary embodiment the further supporting rollers 11 are not adjustable. Reference sign 12 denotes a straightening gap formed between the lower straightening rollers 7 and the upper straightening rollers 9.

(14) FIG. 4 shows a schematic view of actuating devices 13 for moving holding devices 5 (not shown here) supported thereon in the vertical direction V. Each of the actuating devices 13 comprises an actuating drive 3, by means of which two lower wedges 14 are displaceable relative to one another. An upper double wedge 15, which performs a vertical movement when the distance between the lower wedges 14 changes, is supported on the lower wedges 14.

(15) In FIG. 5, a calculated actual stress curve is shown by reference sign IS, which curve shows the profile of the stresses produced in a straightening roller 7, 9. In the present example the predefined limiting values stored in the control system are vMA+1.5*10.sup.8 PA and vMI−1.5*10.sup.8 Pa. The maxima MA and minima MI of the actual stress curve IS are given by the adjustment of an actuating device and/or the sheet metal guided through between the straightening rollers 7, 9. Under consideration of an elastic deformation resistance of the lower straightening roller 7, the bending line B shown in FIG. 5 is given by calculation from the actual stress curve IS. If the actual stress curve IS changes, this being brought about for example by adjustment of one of the actuating devices 13, the bending line B changes.

(16) An upper limiting value vMA and a lower limiting value vMI are stored in the computer program of the control system. If a minimum MI or a maximum MA of the actual stress curve lies outside the limiting values vMA, vMI, an adjustment of further actuating devices 13 is changed iteratively until the predefined limiting values vMA, vMI are complied with.

(17) The method according to the invention will now be explained in greater detail with reference to the flow diagram in FIG. 6:

(18) At the start of the method, a manual change is made to an adjustment of one of the supporting roll devices 4. Such a manual adjustment is performed by an operator, for example if a planarity error is observed in the sheet metal strip running out from the roller straightening machine. As a result of the change to the adjustment nj, the current actual stress curve is calculated over the width of the straightening roller. The maxima MA and the minima MI of the current actual stress curve IS are then calculated. If all maxima MA and minima MI are within the predefined limiting values vMA, vMI, the routine is ended.

(19) If a maximum MA or a minimum MI are not within the predefined limiting values vMA, vMI, the adjustment is firstly changed step-by-step in accordance with the algorithm in a directly adjacent actuating device, and the current actual stress curve over the straightening roller is then calculated. The maxima MA and minima MI of the actual stress curve are then, in turn, calculated, and by repeating the routine it is checked whether they lie within the upper limiting value vMA and the lower limiting value vMI. If this is not the case, the routine is repeated for all further adjacent actuating devices until the predefined upper limiting value vMA and the lower limiting value vMI are complied with.

(20) Although in the above exemplary embodiment the method according to the invention has been explained with use of a calculated actual stress curve, it is also possible to omit the calculation of such an actual stress curve. In order to carry out the method according to the invention, a calculation of the current maxima MA and minima MI as well as a comparison of the current maxima MA and minima MI with the predefined upper vMA and lower limiting value vMI are sufficient.

(21) FIG. 7 shows a display operating the computer program according to FIG. 6. Each supporting roller device 4 is assigned 2 first buttons 16. By actuating one of the first buttons 16, an adjustment of the corresponding supporting roller device 4 may be increased. The resultant target and actual values of the adjustment may be deduced from a display field 17 arranged above. The target and actual values are shown graphically once more below the first buttons 16. Next to the graphical representation of the target and actual values, there are two “tilt” buttons 18. By actuating the second buttons 18, actuating devices 4 may be adjusted in accordance with a “tilt” adjustment mode provided in the algorithm such that the width of the straightening gap 12 over the axial direction A is changed in some sections. In principle, the method explained in FIG. 6 may also be carried out in the “tilt” adjustment mode, i.e. in this case too there is an iterative adjustment of the actuating devices 4 in such a way that the resultant maxima MA and minima MI are kept within the predefined upper limiting value vMA and lower limiting value vMI.

(22) Although it is not shown in FIG. 7, further first buttons are provided in the display below the graphical presentation of the target and actual positions and may be used to decrease an adjustment of the actuating devices 4. The further first buttons have been left out for the sake of clarity. They correspond to the first buttons 16 in respect of their design, although the direction arrows are reversed.

(23) FIGS. 8-1 to 8-13 show deviations of the equations for the equilibriums of moments. The equation systems 1 to 11 shows the equations for the equilibriums of moments.

(24) The advantageous consideration of the torsional stresses of the straightening rollers is shown after the equation system 1 to 11. The abbreviation “GEH” means “design modification hypothesis”.

LIST OF REFERENCE SIGNS

(25) 1 lower roller mill 2 upper roller mill 3 actuating drive 4 actuating device 5 holding device 6 supporting roller 7 (lower) straightening roller 8 intermediate roller 9 upper straightening roller 10 further intermediate roller 11 further supporting roller 12 straightening gap 13 actuating device 14 lower wedge 15 upper double wedge 16 first button 17 display field 18 second button A axial direction B bending line IS actual stress curve MA maximum MI minimum T transport direction V vertical direction vMA upper limiting value vMI lower limiting value