Flatness-measuring device, hot-rolling mill and method for operating a flatness-measuring device

Abstract

A flatness-measuring device for a hot-rolled strip within a hot-rolling mill includes an entry-side deflection roller and an exit-side deflection roller. A central deflection roller is arranged between the entry-side deflection roller and the exit-side deflection roller. The central deflection roller is used as a flatness-measuring roller. To prevent the hot-rolled strip from departing laterally during a flatness measurement, the flatness-measuring device has a sensing apparatus for sensing an actual position of the hot-rolled strip. An adjusting apparatus is connected to the sensing apparatus and to at least one of the deflection rollers. The flatness-measuring device is designed to vary an angle between a longitudinal central axis of the deflection roller respectively connected to the adjusting apparatus and a longitudinal axis of the flatness-measuring device based on a deviation of the actual position of the hot-rolled strip from a predefined target position.

Claims

1.-15. (canceled)

16. A flatness-measuring device (1) for measuring flatness of a hot-rolled strip (2) within a hot-rolling mill, comprising: an entry-side deflection roller (3) for contacting a first large side of the hot-rolled strip (2); an exit-side deflection roller (5) for contacting the first large side of the hot-rolled strip (2); a central deflection roller (7) arranged between the entry-side deflection roller (3) and the exit-side deflection roller (5) with respect to a strip running direction (6) of the hot-rolled strip (2), wherein the central deflection roller (7) is configured to placed against a second large side of the hot-rolled strip (2) opposite from the first large side of the hot-rolled strip (2), and wherein the central deflection roller (7) is used as a flatness-measuring roller; a sensing apparatus (8) for sensing an actual position (L.sub.Ist) of the hot-rolled strip (2); and an adjusting apparatus (9) that is connected to the sensing apparatus (8) and to one of the deflection rollers (3, 5, 7) and is designed to vary an angle (α) between a longitudinal central axis (10) of the one of the deflection rollers (3, 5, 7) connected to the adjusting apparatus (9) and a longitudinal axis (11) of the flatness-measuring device (1) running transversely to the deflection rollers (3, 5, 7) based on a deviation of the actual position (L.sub.Ist) of the hot-rolled strip (2) from a predefined target position (L.sub.Soll) of the hot-rolled strip (2).

17. The flatness-measuring device (1) according to claim 16, wherein the adjusting apparatus (9) is designed to determine an actual position (P.sub.Ist) of the one of the deflection rollers (3, 5, 7) connected to the adjusting apparatus (9), to determine a target position (P.sub.Soll) of the one of the deflection rollers (3, 5, 7) from the deviation of the actual position (L.sub.Ist) of the hot-rolled strip (2) from the predefined target position (L.sub.Soll) of the hot-rolled strip (2), and to determine a target adjustment speed value (V.sub.Soll) for adjusting the angle (α) between the longitudinal central axis (10) of the one of the deflection rollers (3, 5, 7) and the longitudinal axis (11) of the flatness-measuring device (1) based on a deviation of the actual position (P.sub.Ist) of the one of the deflection rollers (3, 5, 7) from the target position (P.sub.Soll) of the one of the deflection rollers (3, 5, 7).

18. The flatness-measuring device (1) according to claim 17, wherein the adjusting apparatus (9) is designed to determine a speed of a lateral movement of the hot-rolled strip (2) and to determine the target adjustment speed value (V.sub.Soll) based on the speed of the lateral movement of the hot-rolled strip (2).

19. The flatness-measuring device (1) according to claim 16, wherein the adjusting apparatus (9) is designed to pivot the one of the deflection rollers (3, 5, 7) connected to the adjusting apparatus (9) and/or another of the deflection rollers (3, 5, 7) in a plane that is arranged perpendicular to the longitudinal axis (11) of the flatness-measuring device (1), and to carry out the pivoting of the respective deflection roller (3, 5, 7) in the plane based on an angular value by which the angle (α) between the longitudinal central axis (10) of the one of the deflection rollers (3, 5, 7) and the longitudinal axis (11) of the flatness-measuring device (1) can be varied by the adjusting apparatus (9).

20. The flatness-measuring device (1) according to claim 16, wherein the one of the deflection rollers (3, 5, 7) connected to the adjusting apparatus (9) is arranged displaceably about an axis of rotation running perpendicularly to a strip section of the hot-rolled strip (2) that can be fed to the one of the deflection rollers (3, 5, 7), wherein the axis of rotation is arranged through a center of the one of the deflection rollers (3, 5, 7) or offset to the longitudinal axis (10) of the one of the deflection rollers (3, 5, 7) from the center of the one of the deflection rollers (3, 5, 7).

21. The flatness-measuring device (1) according to claim 16, further comprising an electromechanical drive connected to the one of the deflection rollers (3, 5, 7) connected to the adjusting apparatus (9), or a hydraulic actuating cylinder connected to the one of the deflection rollers (3, 5, 7).

22. The flatness-measuring device (1) according to claim 16, further comprising a holding frame on which the entry-side deflection roller (3), the exit-side deflection roller (5), and/or the central deflection roller (7) are or is rotatably mounted, wherein the adjusting apparatus (9) is connected to the one of the deflection rollers (3, 5, 7) via the holding frame and the holding frame is displaceable together with the one of the deflection rollers (3, 5, 7) connected thereto.

23. The flatness-measuring device (1) according to claim 16, wherein at least one of the deflection rollers (3, 5, 7) has a bale surface with increased roughness relative to another of the deflection rollers (3, 5, 7).

24. The flatness-measuring device (1) according to claim 16, wherein at least one of the deflection rollers (3, 5, 7) has a wear-resistant bale coating.

25. The flatness-measuring device (1) according to claim 16, wherein the sensing apparatus (8) is arranged and designed in such a manner as to sense an entry-side actual position (L.sub.Ist) of the hot-rolled strip (2) or an exit-side actual position (L.sub.Ist) of the hot-rolled strip (2).

26. A hot-rolling mill comprising the flatness-measuring device (1) according to claim 16.

27. A method for operating a flatness-measuring device (1) for measuring flatness of a hot-rolled strip (2) within a hot-rolling mill, wherein the flatness-measuring device (1) has an entry-side deflection roller (3) for contacting a first large side of the hot-rolled strip (2), an exit-side deflection roller (5) for contacting the first large side of the hot-rolled strip (2), and a central deflection roller (7), which is arranged between the entry-side deflection roller (3) and the exit-side deflection roller (5) with respect to a strip running direction (6) of the hot-rolled strip (2), wherein the central deflection roller (7) is configured to placed against a second large side of the hot-rolled strip (2) opposite from the first large side of the hot-rolled strip (2), and wherein the central deflection roller (7) is used as a flatness-measuring roller, the method comprising: sensing an actual position (L.sub.Ist) of the hot-rolled strip (2); and varying an angle (α) between a longitudinal central axis (10) of one of the deflection rollers (3, 5, 7) and a longitudinal axis (11) of the flatness-measuring device (1) based on a deviation of the actual position (L.sub.Ist) of the hot-rolled strip (2) from a predefined target position (L.sub.Soll) of the hot-rolled strip (2).

28. The method according to claim 27, further comprising: determining an actual position (P.sub.Ist) of the one of the deflection rollers (3, 5, 7), the position of which can be varied; determining a target position (P.sub.Soll) of the one of the deflection rollers (3, 5, 7) from the deviation of the actual position (L.sub.Ist) of the hot-rolled strip (2) from the predefined target position (L.sub.Soll) of the hot-rolled strip (2); and determining a target adjustment speed value (V.sub.Soll) for adjusting the angle (α) between the longitudinal central axis (10) of the one of the deflection rollers (3, 5, 7) and the longitudinal axis (11) of the flatness-measuring device (1) based on a deviation of the actual position (P.sub.Ist) of the one of the deflection rollers (3, 5, 7) from the target position (P.sub.Soll) of the one of the deflection rollers (3, 5, 7).

29. The method according to claim 28, further comprising: determining a speed of a lateral movement of the hot-rolled strip (2); and determining the target adjustment speed value (V.sub.Soll) based on the speed of the lateral movement of the hot-rolled strip (2).

30. The method according to claim 27, further comprising: pivoting the one of the deflection rollers (3, 5, 7), the position of which can be varied, and/or another one of the deflection rollers (3, 5, 7) in a plane that is perpendicular to the longitudinal axis (11) of the flatness-measuring device (1), wherein the pivoting of the one of the deflection rollers (3, 5, 7) in the plane is carried out based on an angular value by which the angle (α) between the longitudinal central axis (10) of the one of the deflection rollers (3, 5, 7) and the longitudinal axis (11) of the flatness-measuring device (1) can be varied.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1A is a schematic top view of an exemplary embodiment of a flatness-measuring device;

[0043] FIG. 1B is a schematic side view of the flatness-measuring device shown in FIG. 1A; and

[0044] FIG. 2 is a flow chart of an exemplary embodiment of a method for operating a flatness-measuring device.

DETAILED DESCRIPTION

[0045] In the figures, identical or functionally identical components are given the same reference signs. A repeated description of these components can be omitted.

[0046] FIG. 1A shows a schematic top view of an exemplary embodiment of a flatness-measuring device 1 for measuring the flatness of a hot-rolled strip 2 within a hot-rolling mill (not shown).

[0047] The flatness-measuring device 1 has an entry-side deflection roller 3 for contacting a first large side in the form of a lower side of the hot-rolled strip 2. The entry-side deflection roller 3 is part of an entry-side roller table, of which two further guide rollers 4 are shown. The entry-side deflection roller 3 can have a bale surface with increased roughness. In addition, the entry-side deflection roller 3 can have a wear-resistant bale coating (not shown).

[0048] In addition, the flatness-measuring device 1 has an exit-side deflection roller 5 for contacting the first large side in the form of the lower side of the hot-rolled strip 2. The exit-side deflection roller 5 is part of an exit-side roller table, of which another guide roller 4 is shown. The exit-side deflection roller 5 can have a bale surface with increased roughness. In addition, the deflection roller 5 on the exit side can have a wear-resistant bale coating (not shown).

[0049] Furthermore, the flatness-measuring device 1 has a central deflection roller 7 arranged with respect to a strip running direction 6 of the hot-rolled strip 2 between the entry-side deflection roller 3 and the exit-side deflection roller 5 and adjustable against a second large side opposite from the first large side of the hot-rolled strip 2 in the form of an upper side of the hot-rolled strip 2. The central deflection roller 7 is used as a flatness-measuring roller and can have a bale surface with increased roughness. In addition, the central deflection roller 7 can have a wear-resistant bale coating (not shown).

[0050] In addition, the flatness-measuring device 1 has a sensing apparatus 8 for sensing an actual position of the hot-rolled strip 2. The sensing apparatus 8 can have at least one optical sensor (not shown), for example a camera.

[0051] The flatness-measuring device 1 also has an adjusting apparatus 9 connected to the sensing apparatus 8, the entry-side deflection roller 3 and the central deflection roller 7. The adjusting apparatus 9 is designed to vary an angle α between a longitudinal central axis 10 of the entry-side deflection roller 3 and a longitudinal axis 11 of the flatness-measuring device 1 running transversely to the deflection rollers 3, 5 and 7 in accordance with a deviation of the actual position of the hot-rolled strip 2 from a predefined target position of the hot-rolled strip 2. For explanatory purposes, the entry-side deflection roller 3 is shown in two pivot positions, once in solid lines and once in dashed lines, wherein the horizontal pivot capability of the entry-side deflection roller 3 is indicated by a double arrow 12. For this purpose, the entry-side deflection roller 3 is arranged so as to be displaceable about an axis of rotation, which is not shown and runs perpendicular to a strip section of the hot-rolled strip 2 fed to the entry-side deflection roller 3 and perpendicular to the drawing plane, wherein the axis of rotation is arranged in a manner offset to the center of the entry-side deflection roller 3 with respect to the longitudinal axis 10 of the entry-side deflection roller 3. The adjusting apparatus 9 has an electromechanical drive (not shown) connected to the entry-side deflection roller 3 or a hydraulic adjusting cylinder connected to the entry-side deflection roller 3.

[0052] The adjusting apparatus 9 is designed to determine an actual position of the entry-side deflection roller 3, determine a target position of the entry-side deflection roller 3 from the deviation of the actual position of the hot-rolled strip 2 from the predefined target position of the hot-rolled strip 2 and determine a target adjustment speed value for adjusting the angle α between the longitudinal central axis 10 of the entry-side deflection roller 3 and the longitudinal axis 11 of the flatness-measuring device 1 in accordance with a deviation of the actual position of the entry-side deflection roller 3 from the target position of the entry-side deflection roller 3. In addition, the adjusting apparatus 9 is designed to determine a speed of a lateral movement of the hot-rolled strip 2 and to determine the target adjustment speed value in accordance with the speed of the lateral movement of the hot-rolled strip 2.

[0053] The adjusting apparatus 9 is further designed to pivot the central deflection roller 7 in a plane perpendicular to the longitudinal axis 11 of the flatness-measuring device 1 and perpendicular to the drawing plane. Furthermore, the adjusting apparatus 9 is designed to carry out the pivoting of the central deflection roller 7 in the plane in accordance with an angular value by which the angle α between the longitudinal central axis 10 of the entry-side deflection roller 3 and the longitudinal axis 11 of the flatness-measuring device 1 can be varied by means of the adjusting apparatus 9.

[0054] The flatness-measuring device 1 can have a holding frame (not shown) and on which the entry-side deflection roller 3, the exit-side deflection roller 5 and/or the central deflection roller 7 are or is, as the case may be, rotatably mounted, wherein the adjusting apparatus 9 is connected via the holding frame to the respective deflection rollers 3, 5 or 7 and the deflection rollers 3, 5 or 7 and the holding frame is displaceable together with the deflection rollers 3, 5 or 7 connected thereto.

[0055] FIG. 1B shows a schematic side view of the flatness-measuring device 1 shown in FIG. 1A. The vertical pivot capability of the center deflection roller 7 is shown, once in solid lines and once in dashed lines, wherein the vertical pivot capability of the center deflection roller 7 is indicated by a double arrow 13.

[0056] FIG. 2 shows a flow chart of an exemplary embodiment of a method for operating a flatness-measuring device for measuring the flatness of a hot-rolled strip within a hot-rolling mill. The flatness-measuring device can be formed according to the exemplary embodiment shown in FIGS. 1A and 1B.

[0057] First, an actual position L.sub.Ist of the hot-rolled strip is sensed. A difference is formed from the actual position L.sub.Ist and a predefined target position L.sub.Soll of the hot-rolled strip by means of a subtracting element D1 of the adjusting apparatus, which is fed to a center controller M of the adjusting apparatus of the flatness-measuring device. In accordance with the difference, the center controller M generates a target position P.sub.Soll of the deflection roller connected to the adjusting apparatus, which optimizes the strip run of the hot-rolled strip. In addition, an actual position P.sub.Ist of the deflection roller connected to the adjusting apparatus is sensed. The actual position P.sub.Ist of the deflection roller and the target position P.sub.Soll of the deflection roller are used to form a further difference by means of a further subtracting element D2 of the adjusting apparatus, which is fed to a pivot controller S of the adjusting apparatus of the flatness-measuring device. The pivot controller S generates an adjustment speed value in accordance with the difference D2 for adjusting the angle between the longitudinal central axis of the deflection roller connected to the adjusting apparatus and the longitudinal axis of the flatness-measuring device. The difference generated by means of the subtracting element D1 is also fed to a differential controller D of the adjusting apparatus, which determines a speed of a lateral movement of the hot-rolled strip and uses such speed to determine an additional value for the adjustment speed. The adjustment speed value generated by the pivot controller S and the additional value generated by the differential controller D are added by means of an adding element A of the adjusting apparatus, resulting in a target position adjustment speed value V.sub.Soll, which can be used to control actuators of the adjusting apparatus.

[0058] Consequently, in accordance with the method, an angle between a longitudinal central axis of the deflection roller connected to the adjusting apparatus and a longitudinal axis of the flatness-measuring device running transversely to the deflection rollers is varied in accordance with a deviation of the actual position L.sub.Ist of the hot-rolled strip from a predefined target position L.sub.Soll of the hot-rolled strip. Thereby, in accordance with the method, an actual position P.sub.Ist of the deflection roller connected to the adjusting apparatus, the position of which can be varied accordingly, is determined, a target position P.sub.Soll of the deflection roller connected to the adjusting apparatus is determined from the deviation of the actual position L.sub.Ist of the hot-rolled strip from the predefined target position L.sub.Soll of the hot-rolled strip, and a target adjustment speed additional value for adjusting the angle between the longitudinal central axis of the deflection roller connected to the adjusting apparatus and the longitudinal axis of the flatness-measuring device is determined in accordance with a deviation of the actual position P.sub.Ist of such deflection roller from the target position P.sub.Soll of such deflection roller. In addition, in accordance with the method, a speed of a lateral movement of the hot-rolled strip is determined and the target adjustment speed additional value is determined in accordance with the speed of the lateral movement of the hot-rolled strip.

[0059] In order to compensate for a change in the geometry of the clamping of the hot-rolled strip in the flatness-measuring device caused by an adjustment of the deflection roller connected to the adjusting apparatus, the deflection roller, the position of which can be varied accordingly, or another deflection roller of the flatness-measuring device can be pivoted in a plane that is arranged in a manner perpendicular to the longitudinal axis of the flatness-measuring device. The pivoting of such deflection roller in the plane can be carried out in accordance with an angular value by which the angle between the longitudinal central axis of the deflection roller, the pivoting of which has caused the change in geometry, and the longitudinal axis of the flatness-measuring device can be varied.

LIST OF REFERENCE SIGNS

[0060] 1 Flatness-measuring device [0061] 2 Hot-rolled strip [0062] 3 Entry-side deflection roller [0063] 4 Guide roller [0064] 5 Exit-side deflection roller [0065] 6 Strip running direction [0066] 7 Central deflection roller [0067] 8 Sensing apparatus [0068] 9 Adjusting apparatus [0069] 10 Longitudinal central axis of 3 [0070] 11 Longitudinal axis from 1 [0071] 12 Double arrow (pivot capability of 3) [0072] 13 Double arrow (pivot capability of 7) [0073] A Adding element [0074] D Differential controller [0075] D1 Subtracting element [0076] D2 Subtracting element [0077] L.sub.Ist Actual position of 2 [0078] L.sub.Soll Target position of 2 [0079] M Center controller [0080] P.sub.Ist Actual position of 3, 5, 7 [0081] P.sub.Soll Target position of 3, 5, 7 [0082] S Pivot controller [0083] V.sub.Soll Target position speed value [0084] α Angle between 10 and 11