STRAIGHTENING MACHINE AND METHOD FOR STRAIGHTENING A METAL STRIP OR A FLAT METAL PART

Abstract

A straightening machine (1) and a method for straightening a metal strip or a flat metal part (16) by the straightening machine, having upper straightening rollers (3) in an upper roller mill (2) and lower straightening rollers (6) in a lower roller mill (5). The upper and lower straightening rollers form upper and lower roller mill planes with a straightening gap therebetween and act on the metal strip to be straightened. In a working position, the upper roller mill plane forms an operating angle to the lower roller mill plane. The straightening gap (11) is changed by adjusting the upper roller mill plane relative to the lower roller mill plane. Before or at the start of a straightening process, the upper and/or lower roller mill is put in a starting position with a widened straightening nip, at least until a front end of the material strip has entered the inlet of the working region and for the rest of the straightening process, the upper and/or lower roller mill is put in the working position.

Claims

1. A method for straightening a material strip or a flat material part composed of a material which is plasticizable using a straightening machine (1) with a number of upper straightening rollers (3) in an upper roller mill (2) and a number of lower straightening rollers (6) in a lower roller mill (5), which form a straightening gap (11) between an inlet (12) and an outlet (13) of the straightening machine (1) in an operating region between the upper and the lower roller mill (2, 5), the upper and the lower straightening rollers (3, 6) in an operating position of the upper and lower roller mill (2, 5) act at least temporarily from top to bottom on the material strip or material part to be straightened and guide the material strip or part in an operating direction (14) from the inlet (12) to the outlet (13) of the operating region through the straightening machine (1), at least a part of axes (9) of the upper straightening rollers (3) form an upper roller mill plane (4) and at least a part of axes (9) of the lower straightening rollers (6) forms lower roller mill plane (7), which in the operating position are parallel or at a predetermined operating angle (8) to one another, the method comprising: in order to change the straightening gap (11), at least one of adjusting the upper roller mill (2) relative to the lower roller mill (5) or adjusting the lower roller mill (5) relative to the upper roller mill (2); and prior to or at a start of a straightening process, placing at least one of the upper or lower roller mill (2, 5) into a starting position at least until a front end of the material strip or material part has run into the inlet (12) of an operating region of the straightening machine (1) by widening the straightening gap (11) to a greater extent that at the outlet (13), widening the straightening gap (11) to a greater extent at the outlet (13) than at the inlet (12); and for the further straightening process, advancing at least one of the upper or lower roller mill (2, 5) into an operating position.

2. The method as claimed in claim 1, wherein the straightening gap (11) during placing into the starting position is widened to a greater extent at the inlet (12) than at the outlet (13) if the operating angle (8) opens toward the outlet (13) or the upper roller mill plane (4) is parallel to the lower roller mill plane (7), or the straightening gap (11) during placing into the starting position is widened to a greater extent at the outlet (13) than at the inlet (12) if the operating angle (8) opens toward the inlet (12).

3. The method as claimed in claim 1, further comprising the method steps: (A) placing at least one of the upper or lower roller mill (2, 5) into the starting position; and (B) advancing at least one of the upper or lower roller mill (2, 5) into the operating position, wherein method step B is performed when or after the front end (17) of the material strip or material part (16) has reached a predetermined position (15) in the operating region.

4. The method as claimed in claim 3, wherein a region of the inlet (11), or a location of one of the lower or upper straightening rollers (3, 6) is used as the predetermined position (15).

5. The method as claimed in claim 3, wherein the front end (17) of the material strip or material part is detected by a sensor (18).

6. The method as claimed in claim 5, wherein the sensor (18) is arranged at the predetermined position (15) and method step B is performed immediately after detection of the front end (17) of the material strip or material part (16) by the sensor (18).

7. The method as claimed in claim 5, wherein the sensor (18) is arranged at a spacing (19) upstream of the predetermined position (15) in the operating direction (14), and the method further comprises determining a time delay until the predetermined position (15) of the front end (17) of the material strip or material part (16) is reached from a conveying speed of the material strip or material part and the spacing (19) between the sensor (18) and the predetermined position (15), and method step B is performed with or after the end of the time delay after detection of the front end (17) of the material strip or material part by the sensor (18).

8. The method as claimed in claim 1, wherein at least one of a) the placing of at least one of the upper or lower roller mill (2, 5) into the starting position is performed such that the straightening gap (11) in a region of the inlet (12) corresponds at least to a thickness of the material strip or material part (16) or b) the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed such that the straightening gap (11) in a region of the outlet (13) corresponds substantially to the thickness of the material strip or material part (16).

9. The method as claimed in claim 1, wherein at least one of a) the placing of at least one of the upper or lower roller mill (2, 5) into the starting position is performed such that the straightening gap (11) in a region of the outlet (13) corresponds at least to a thickness of the material strip or material part (16) or 12) the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed such that the straightening gap (11) in a region of the inlet (12) corresponds substantially to the thickness of the material strip or material part (16).

10. The method as claimed in claim 1, wherein the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed continuously.

11. The method as claimed in claim 1, wherein the advancing of at least one of the upper or lower roller mill (2, 5) into the operating position is performed in an incremental manner.

12. The method as claimed in claim 11, wherein one step of the advancing is performed with or after passing at least one of one said lower or upper straightening roller (3, 6), and the advancing is performed in the step such that the spacing of the upper and lower straightening rollers (3, 6) at a downstream said upper and/or lower straightening roller (3, 6) corresponds substantially to the thickness of the material strip or material part (16).

13. The method as claimed in claim 1, wherein at least one of the upper roller mill (2) or the lower roller mill (5) is moved at least partially via a pivoting movement into at least one of the starting position or the operating position.

14. A straightening machine (1) for straightening a material strip or a flat material composed of a material which can be plasticized, the straightening machine comprising: a number of upper straightening rollers (3) in an upper roller mill (2); a number of lower straightening rollers (6) in a lower roller mill (5); a straightening gap formed between an inlet (12) and an outlet (13) of the straightening machine (1) in an operating region between the upper and the lower roller mills (2, 5), the straightening gap (11), in an operating position of the upper and lower roller mills (2, 5) being configured to act at least temporarily from top to bottom on the material strip or material part to be straightened and guide the material strip or material part in an operating direction (14) from the inlet (12) to the outlet (13) of the working region through the straightening machine (1); at least a part of axes (9) of the upper straightening rollers (3) form an upper roller mill plane (4) and at least a part of axes (9) of the lower straightening rollers (6) form a lower roller mill plane (7) which in the operating position are parallel or at a predetermined operating angle (8) to one another; in order to change the straightening gap (11), the upper roller mill (2) and the lower roller mill (5) are adjustable relative to one another, and are placeable at least into a starting position with a widened straightening gap (11) and are advanceable into the starting position; a controller (22) configured to adjust the upper and lower roller mills (2, 5) with respect to one another; a sensor (18) for detection of a front end (17) of the material strip or material part (16) to be straightened, the sensor configured to output a sensor signal to the controller (22); the controller (22) being further configured to adjust at least one of the upper or lower roller mill (2, 5) from the starting position into the operating position immediately after or with a time delay to the sensor signal; and the upper roller mill (2) and the lower roller mill (5) are adjustable relative to one another such that the straightening gap (11) during placing into the starting position is widened to a greater extent at the inlet (12) than at the outlet (13), or is widened to a greater extent at the outlet (13) than at the inlet (12).

15. The straightening machine as claimed in claim 14, wherein the controller (22) is configured to widen the straightening gap (11) during placing into the starting position at the inlet (12) to a greater extent than at the outlet (13) if the operating angle (8) opens toward the outlet (13) or the upper roller mill plane (4) is parallel to the lower roller mill plane (7), or to widen the straightening gap (11) during placing into the starting position at the outlet (13) to a greater extent than at the inlet (12) if the operating angle (8) opens toward the inlet (12).

16. The straightening machine as claimed in claim 14, wherein the upper roller mill plane (4) encloses a starting angle (10) to the lower roller mill plane (7) in the starting position, and said starting angle (10) is not equal to the operating angle (8).

17. The straightening machine as claimed in claim 14, wherein the sensor (18) is arranged at a height of a predetermined position (15), or upstream in the operating direction (14) at a spacing (19) in front of the predetermined position (15), wherein the predetermined position (15) lies in a region of the inlet (12), or corresponds to a location of one of the lower or upper straightening rollers.

18. The straightening machine as claimed in claim 17, wherein the controller (22) is configured such that the time delay for the adjustment of at least one of the upper or lower roller mill (2, 5) into the operating position is determined from a conveying speed of the material strip or material part and the spacing (19) between the sensor (18) and the predetermined position (15).

19. The straightening machine as claimed in claim 14, wherein the sensor (18) is a physical sensor.

20. The straightening machine as claimed in claim 14, wherein at least one of a) the upper roller mill (2) is pivotable with respect to the lower roller mill (5) or b) the lower roller mill (5) is pivotable with respect to the upper roller mill (2) about a pivot axis, and the pivot axis lies outside an operating region of the straightening machine (1).

21. The straightening machine as claimed in claim 14, wherein the upper roller mill (2) is retained in guides (20) of the straightening machine (1) and is movable up and down on the guides (20) relative to the lower roller mill (3), and the guides (20) are formed such that the upper roller mill (2) is at least one of adjustable or pivotable asymmetrically on the guides (20).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] An exemplary embodiment of a straightening machine configured according to the invention, on the basis of which an exemplary embodiment of a method according to the invention is also explained, is described below on the basis of the enclosed drawings. In the drawings:

[0052] FIG. 1 shows a schematic side view of the straightening machine in the starting position; and

[0053] FIG. 2 shows a schematic side view of a straightening machine in the operating position.

DETAILED DESCRIPTION

[0054] A straightening machine 1 according to the invention is represented schematically in a side view in a starting position in FIG. 1. The straightening machine 1 comprises an upper roller mill 2 on which a multiplicity of upper straightening rollers 3, in the present case four upper straightening rollers 3, is arranged. A lower roller mill 5 which also comprises a multiplicity of lower straightening rollers 6, in the present case five lower straightening rollers 6, is arranged opposite the upper roller mill 2. The upper and lower straightening rollers 3, 6 are in the upper and lower roller mill 2, 5 equidistant and arranged in such a manner that an upper straightening roller 3 engages into the region of the space between two lower straightening rollers 6.

[0055] A lower roller mill plane 7 runs through the axes 9 of the lower straightening rollers 6; an upper roller mill plane 4 runs in an analogous manner through the axes 9 of the upper straightening rollers 3. Alternatively, the upper roller mill plane 4 can only partially comprise the axes 9 of the upper straightening rollers 3, in particular if a first upper straightening roller 3 in the operating direction 14 is raised with respect to the further upper straightening rollers 3. The lower roller mill plane 7 can likewise only partially comprise the axes 9 of the lower straightening rollers 6 in particular if a last lower straightening roller 6 in the operating direction is lowered.

[0056] The upper roller mill 2 is guided on four guides 20 which are configured as stud bolts, and it can be moved along these guides 20 translationally to the lower roller mill 5 and moved away therefrom. The upper roller mill 2 is guided in the guides 20 in such a manner that the upper roller mill 5 is adjustable within the guides 20 asymmetrically between inlet 12 and outlet 13 of the straightening machine 1 and/or is pivotable about an axis which runs parallel to the roller mill planes 4, 7.

[0057] For this purpose, there is arranged on the upper roller mill 2 a pivoting apparatus 21, by means of which the upper roller mill 2 is pivotable with respect to the lower roller mill 5 about a pivot axis, as a result of which the upper roller mill plane 4 is also changed with respect to the lower roller mill plane 7. The pivoting apparatus 21 is in this case operatively connected to the guides 20, arranged at the outlet 13, of the straightening machine 1. In addition to the pivoting apparatus 21, the upper roller mill 2 can be moved up and down with respect to the lower roller mill 5 in the guides 20 parallel to the lower roller mill 5.

[0058] In the starting position of the straightening machine 1, as is represented in FIG. 1, the lower roller mill plane 7 and the upper roller mill plane 4 enclose a starting angle 10 which opens toward the outlet 13. This starting angle 10 between the upper and lower roller mill plane 4, 7 in the starting position is formed in this case so that it is smaller than an operating angle 8 in the operating position (FIG. 2), i.e. the straightening gap 11 is widened to a greater extent in comparison with the operating position at the inlet 12 than at the outlet 13. With a pivoting of the upper roller mill 2 with respect to the lower roller mill 5 about the pivot axis, the straightening gap 11 is widened along the operating region of the straightening machine 1 between inlet 12 and outlet 13 so that the spacing of the upper straightening rollers 3 with respect to the lower straightening rollers 6 is also increased overall in comparison with the operating position. In the starting position, the straightening gap 11 in the region of the inlet 12 is formed in such a manner that it corresponds at least to the thickness of the metal part 16 to be straightened. For further widening of the inlet 12 of the straightening machine 1, the upper roller mill 2 can, in addition to the pivoting movement about the pivot axis, also additionally be displaced parallel along the guides 20. The movement of the upper roller mill 2 is controlled or regulated via a controller 22. In addition to the upper roller mill 2, the pivoting apparatus 21 is also operatively connected to the controller 22.

[0059] For the straightening of the metal part 16, the straightening machine 1 is firstly brought into the starting position, as represented in FIG. 1, in which the straightening machine 1 has a widened straightening gap 11 and a starting angle 10 between the upper and lower roller mill plane 4, 7 which opens toward the outlet 13, but is formed to be smaller than the operating angle 8.

[0060] A flat metal part 16 to be straightened firstly passes a sensor 18 during transport into the straightening machine 1 in operating direction 14, which sensor 18 detects a front end 17 of the metal part 16. The sensor 18 is formed in the present case as a light barrier and is arranged in a region upstream of the inlet 12 in operating direction 14. As a result of the arrangement outside the straightening machine 1, the sensor 18 is easily accessible in comparison with an installation of the sensor 18 within the straightening machine 1 and enables fault-free detection of the front end 17 of the metal part 16. The sensor 18 arranged in such a manner can furthermore where necessary be adapted flexibly and quickly to different metal strips or parts to be straightened, in particular of a different thickness. Alternatively, it is also possible that the sensor 18 is arranged within the straightening machine 1, in particular in the region of the inlet 12 or one of the first upper or lower straightening rollers 3, 6. The sensor 18 is also operatively connected to the controller 22 and outputs a corresponding sensor signal to the controller 22 during detection of the front end 17 of the metal part 16.

[0061] The front end 17 of the metal part 16 firstly runs through the inlet 12 of the straightening machine 1 along the conveying path of the metal part 16 into the straightening machine 1, along which the metal part 16 is conveyed with a constant speed. By widening the straightening machine 1 in the region of the inlet 12 at least into the region of the material thickness of the metal part 16 by pivoting the upper roller mill 2 with respect to the lower roller mill 5, it is ensured that the front end 17 of the metal part 16 does not collide with an upper straightening roller 3 or the upper roller mill 2. Moreover, during entry into the straightening machine 1, the region around the front end 17 of the metal part 16 initially does not experience any forces which could lead to a deformation of the front end 17, in particular to crushing. As soon as the front end 17 of the metal part 16 has reached or passed a predetermined position 15 which in the present case corresponds to the location of the axis 9 of the second upper straightening roller in operating direction 14, the upper roller mill 2 is moved incrementally from the starting position, as is represented in FIG. 1, into the operating position, as is represented in FIG. 2.

[0062] In the operating position, the upper roller mill plane 4 and the lower roller mill plane 7 enclose an operating angle 8 to one another. A straightening gap 11 is formed between the upper and lower straightening rollers 3, 6 in the operating position over the operating region between inlet 12 and outlet 13, in which straightening gap 11 corresponding forces are exerted at least temporarily via the upper and lower straightening rollers 3, 6 from top to bottom on the metal part 16 to be straightened. In this case, the metal part 16 is bent between the upper and lower straightening rollers 3, 6 arranged offset to one another, wherein a more pronounced bending of the metal part 16, beyond its yield point, occurs in the region of the inlet 12. As a result of the bending of the metal part 16 in the straightening gap 11, bending and tension in the metal part 16 are reduced. A lower degree of bending of the metal part 16 occurs at each subsequent upper or lower straightening roller 3, 6 in operating direction 14 so that a straightened and flat metal part 16 is conveyed out of the straightening machine 1 at the outlet 13. The further processing of the metal part 16 is significantly simplified and improved by the straightening.

[0063] In the operating position, the operating angle 8 between the upper and lower roller mill plane 4, 7 is formed in such a manner that, in the region of the outlet 13, the straightening gap 11 corresponds substantially to the material thickness of the metal part 16 to be straightened and that, in the region of the inlet 12, the upper and lower straightening rollers 3, 6 in the straightening gap 11 have a spacing smaller than the material thickness of the metal part 16.

[0064] The axes 9 of the lower straightening rollers 6 lie here in the lower roller mill plane 7 and the axes 9 of the upper straightening rollers 3 span the upper roller mull plane 4, which opens toward the outlet 13. As a result of this, it is achieved that the metal part 16 to be straightened in the straightening machine 1 is bent to a lesser extent toward the outlet 13 and is only slightly deformed.

[0065] The movement or advancing of the upper roller mill 2 from the starting position, as represented in FIG. 1, into the operating position, as represented in FIG. 2, is primarily performed via a pivoting movement of the upper roller mill 2 by means of the pivoting apparatus 21. The pivoting movement is performed incrementally in several steps so that it can be ensured that the front end 17 of the metal part 16 does not collide with one of the upper straightening rollers 3 during conveying into the straightening machine 1. As a result of the incremental movement of the upper roller mill 2 into the operating position, it is furthermore ensured that no crushing occurs in the region of the front end 17 of the metal part 16.

[0066] The incremental advancing from the starting position into the operating position is performed as a function of the conveying of the metal part 16 through the straightening machine 1. A step of further advancing into the operating position is thus triggered by virtue of the fact that the front end 17 of the metal part 16 passes an upper straightening roller 3 arranged after the predetermined position 15. The advancing is performed in the respective step by virtue of the fact that the upper roller mill 2 is pivoted so that an upper straightening roller 3 downstream of the passed upper straightening roller 3 is positioned in such a manner that a spacing to the lower straightening rollers 6 arises which corresponds substantially to the material thickness of the metal part 16. It is thus ensured at all times that the front end 17 of the metal part 16 does not collide with one of the upper straightening rollers 3. The incremental advancing is performed until the front end 17 of the metal part has reached the outlet 13 and the straightening gap 11 in the region of the outlet 13 corresponds substantially to the material thickness of the metal part 16. The straightening gap 11 in the region toward the inlet 12 is furthermore advanced to a greater extent with each step, hence corresponding forces already act on the metal part 16 during advancing, as a result of which the straightening result is improved.

[0067] The movement of the upper roller mill 2 into the operating position is started after the front end 17 of the metal part 16 reaches the predetermined position 15. As represented in FIG. 1, the predetermined position 15 is located within the straightening machine 1 at the height of the axis 9 of the second upper straightening roller 3 downstream in the operating direction 14. As a result of the location of the predetermined position 15 within the straightening machine 1 in the vicinity of the inlet 12, it is likewise ensured that the front end 17 of the metal part 16 is not crushed and rolled out by excessive straightening forces and nevertheless the metal part 16 is optimally straightened. It is achieved in particular as a result of the pivoting movement of the upper roller mill 2 into the operating position that straightening forces are exerted at least partially on the region of the metal part 16 adjoining the front end 17 of the metal part 16, and indeed immediately after the predetermined position 15 has been passed by the front end 17 and the advancing into the operating position has been performed. Alternatively, the predetermined position 15 can lie e.g. also directly at the inlet 12 into the straightening machine 1.

[0068] As also represented in FIG. 1, the sensor 18 for detecting the front end 17 of the metal part 16 is not arranged directly at the predetermined position 15, but rather has a spacing 19 upstream in operating direction 14 to the predetermined position 15. In order to determine the point in time at which the front end 17 of the metal part 16 reaches the predetermined position 15, a time delay is determined via the spacing 19 and the conveying speed of the metal part 16, after which time delay the front end 17 has reached the predetermined position 15 after detection of the corresponding sensor signal by the sensor 18 and the upper roller mill 2 is then adjusted incrementally from the starting position into the operating position.

LIST OF REFERENCE NUMBERS

[0069] 1 Straightening machine [0070] 2 Upper roller mill [0071] 3 Upper straightening roller [0072] 4 Upper roller mill plane [0073] 5 Lower roller mill [0074] 6 Lower straightening roller [0075] 7 Lower roller mill plane [0076] 8 Operating angle [0077] 9 Axis (of 3, 6) [0078] 10 Starting angle [0079] 11 Straightening gap [0080] 12 Inlet [0081] 13 Outlet [0082] 14 Operating direction [0083] 15 Predetermined position [0084] 16 Metal part [0085] 17 Front end [0086] 18 Sensor [0087] 19 Spacing [0088] 20 Guide [0089] 21 Pivoting apparatus [0090] 22 Controller