Rolling mill, and device and method for determining the rolling or guiding gap of the roll stands or guide stands in a multi-stand rolling mill

Abstract

A method for determining the rolling or guiding gap of the roll stands or guide stands in a multi-stand rolling mill positions a comparison scale at at least one stand, preferably at the first and the last stand, and subsequently the rolling or guiding gap of the respective stand is determined. In this method, a camera is arranged at one of the input or output sides and a transmitter for a reference device, a reference transducer and/or a reference scale is arranged at the other of the input or output sides before the comparison scale is positioned, such that adjustment operations at the camera can subsequently be avoided.

Claims

1. Rolling mill comprising: an arrangement of stands comprising at least a first stand and a last stand, the first stand and the last stand selected from a group consisting of roll stands comprising rolls and guide stands comprising guides, said arrangement being arranged along a center line of the rolling mill disposed in a rolling direction, a camera configured to determine rolling gaps of the rolls or guiding gaps of the guides, and a background light that uses a light plate having filter films or LEDs which are collimated and an exit angle from the light plate is reduced which minimizes scattered light from the light plate, and a comparison scale displaced on a support tube positioned between the camera and the light plate of the background light, wherein the rolling mill has an input side and an output side, wherein the camera is fixedly disposed and optically aligned along the center line of the rolling mill at one of the input side and the output side when determining the rolling gaps of the rolls or guiding gaps of the guides, wherein the background light is disposed at the other of the input side and the output side, and wherein the background light is provided on the input side or the output side opposite that of the camera; wherein the camera has an optical device having a depth of field that reaches over an entirety of the arrangement of stands; and wherein an image processing apparatus that follows the camera is configured to determine a contour of roll surfaces of the rolls or guide surfaces of the guides, and wherein the disposition of the camera having said optical device relative to the rolling mill is such that imaging inaccuracies that are caused by a shift in focus and a related movement of the camera optics is avoided.

2. Rolling mill according to claim 1, comprising a light transmitter for a reference device disposed on the other of the input side or the output side opposite that of the camera.

3. Rolling mill according to claim 1, comprising the comparison scale with scale positions in a reference plate that can be disposed in front of or in each roll stand, proceeding from the background light and/or a transmitter toward the camera on the input side or the output side opposite that of the camera.

4. Rolling mill according to claim 1, wherein a holder for the support tube of the comparison scale is disposed at the other of the input side or the output side.

5. Rolling mill according to claim 4, wherein the support tube reaches from the holder to at least through one stand of the arrangement of stands.

6. Rolling mill according to claim 4, wherein the comparison scale can be displaced along the rolling direction.

7. Rolling mill according to claim 4, wherein the support tube is attached centered on the comparison scale.

8. Rolling mill according to claim 4, comprising the comparison scale having at least one translucent region.

9. Rolling mill according to claim 4, comprising the comparison scale having at least two discrete scale positions.

10. Rolling mill according to claim 9, wherein at least one of the scale positions is configured to be circular.

11. Rolling mill according to claim 9, wherein at least one of the scale positions is configured to be transparent or translucent.

12. Rolling mill according to claim 1, wherein the background light is provided on the output side, and the camera is provided on the input side.

13. Rolling mill according to claim 12, wherein the image processing apparatus is provided on the input side.

14. Rolling mill according to claim 1, comprising the comparison scale which is measured only in the region of the background light or at the first stand of said arrangement of stands and/or at the last stand of said arrangement of stands, in order to then be able to extrapolate or interpolate a scale for the other stands.

15. Rolling mill according to claim 14, wherein said interpolation or extrapolation is done by triangulation of measured points on the rolling components of the guide stands or the rolling stands or reference means in the rolling mill and the relative positions of the acquired measured points along the rolling mill with respect to a reference device or by way of beam sets.

16. Rolling mill according to claim 1, said image processing apparatus determining the rolling gaps of the rolls or guiding gaps of the guides, in each instance, from an image of a reference means taken by the camera, the comparison scale, and at least one roll or guide of the rolling mill, wherein the position of the reference means in the image is determined and equated with the center line of the rolling mill, and proceeding from this, the position of the roll or guide is determined by way of the comparison scale.

17. Rolling mill according to claim 16, wherein said reference means is located on the background light, or said rolls or said guides, for example of the first stand or the last stand of the arrangement of stands, are used as a reference scale.

18. Rolling mill according to claim 1, wherein a reference means is located on the background light, or said rolls or said guides, for example of the first stand or the last stand of the arrangement of stands are used as a reference scale.

19. Rolling mill according to claim 1, wherein roll positions of said rolls or guide positions of said guides are determined on-line, by way of measurement value generators, and the measurement value generators are previously calibrated in-line.

20. Rolling mill according to claim 1, wherein said background light is radiating a sufficiently uniform light to said camera so that contours of the rolls or the guides to be measured, in each instance, stand out clearly in front of the background light without repositioning said background light.

21. Rolling mill according to claim 1, comprising reference means being provided at the first and/or the last roll stand, in the region of the background light, or on the background light.

22. Rolling mill comprising: an arrangement of stands comprising at least a first stand and a last stand, the first stand and the last stand selected from a group consisting of roll stands comprising rolls and guide stands comprising guides, said arrangement being arranged along a center line of the rolling mill disposed in a rolling direction, a camera configured to determine the rolling gaps of the rolls or guiding gaps of the guides, and a background light that uses a light plate having filter films or LEDs which are collimated and an exit angle from the light plate is reduced which minimizes scattered light from the light plate, wherein the rolling mill has an input side and an output side, wherein the camera is fixedly disposed and optically aligned along the center line of the rolling mill at one of the input side and the output side when determining the rolling gaps of the rolls or guiding gaps of the guides, wherein the background light is disposed at the other of the input side and the output side, and wherein the background light is provided on the input side or the output side opposite that of the camera; wherein the camera has an optical device having a depth of field that reaches over an entirety of the arrangement of stands; and wherein an image processing apparatus that follows the camera is configured to determine a contour of roll surfaces of the rolls or guide surfaces of the guides, and wherein the disposition of the camera having said optical device relative to the rolling mill is such that imaging inaccuracies that are caused by a shift in focus and a related movement of camera optics can be are avoided; a comparison scale with scale positions that is disposed in front of or in each roll stand, proceeding from the background light or a transmitter; and a support tube for support of the comparison scale is disposed at the other of the input side or the output side.

23. Rolling mill comprising: an arrangement of stands comprising at least a first stand and a last stand, the first stand and the last stand selected from a group consisting of roll stands comprising rolls and guide stands comprising guides, said arrangement being arranged along a center line of the rolling mill disposed in a rolling direction, a camera configured to determine the rolling gaps of the rolls or guiding gaps of the guides, and a background light being always outside of the roll stands; wherein the rolling mill has an input side and an output side, wherein the camera is fixedly disposed at one of the input side and the output side, when determining the rolling gaps of the rolls or guiding gaps of the guides, wherein the background light is disposed at the other of the input side and the output side, and wherein the background light is provided on the input side or the output side opposite that of the camera; wherein the camera has an optical device having a depth of field that reaches over an entirety of the arrangement of stands; and wherein an image processing apparatus that follows the camera is configured to determine a contour of roll surfaces of the rolls or guide surfaces of the guides, and wherein the disposition of the camera having said optical device relative to the rolling mill is such that imaging inaccuracies that are caused by a shift in focus and a related movement of the camera optics are avoided; wherein said background light radiates sufficiently uniform light to the camera so that contours of the rolls or the guides to be measured, stand out clearly in front of said background light, a comparison scale with scale positions that is disposed in front of or in each roll stand, proceeding from the background light or a transmitter.

24. Rolling mill comprising: an arrangement of stands comprising at least a first stand and a last stand, the first stand and the last stand selected from a group consisting of roll stands comprising rolls and guide stands comprising guides, said arrangement being arranged along a center line of the rolling mill disposed in a rolling direction, a camera configured to determine the rolling gaps of the rolls or guiding gaps of the guides, and a background light that uses a light plate having a distance of the light plate to the stands being sufficiently high, and the background light is always outside of the roll stands; wherein the rolling mill has an input side and an output side, wherein the camera is fixedly disposed at one of the input side and the output side, when determining the rolling gaps of the rolls or guiding gaps of the guides, wherein the background light is disposed at the other of the input side and the output side, and wherein the background light is provided on the input side or output side opposite that of the camera; wherein the camera has an optical device having a depth of field that reaches over an entirety of the arrangement of stands; and wherein an image processing apparatus that follows the camera is configured to determine a contour of roll surfaces of the rolls or guide surfaces of the guides, and wherein the disposition of the camera having said optical device relative to the rolling mill is such that imaging inaccuracies that are caused by a shift in focus and a related movement of camera optics are avoided; a comparison scale with scale positions that is disposed in front of or in each roll stand, proceeding from the background light or a transmitter; and a support tube for support of the comparison scale is disposed at the other of the input side or the output side.

Description

(1) Further advantages, goals, and properties of the present invention will be explained using the following description of exemplary embodiments, which are particularly shown also in the attached drawing. The drawing shows:

(2) FIG. 1 a first rolling mill in a schematic side view;

(3) FIG. 2 a comparison scale in a schematic front view;

(4) FIG. 3 a second rolling mill in a schematic side view;

(5) FIG. 4 a third rolling mill in a schematic side view; and

(6) FIG. 5 a fourth rolling mill in a schematic side view.

(7) The rolling mills 1, 2, 3, and 4 shown in FIGS. 1 to 5 comprise roll stands 10, in each instance, which are disposed between an input side 12 and an output side 13, and carry rolls 15, in each instance. In deviation from the rolling mills 1 to 3, which comprise multiple such roll stands 10, in each instance, in the rolling mill 4 only one roll stand and two conical rolls 15, disposed at a slant, and related Diescher disks 16 are disposed on the roll stand 15, whereby furthermore, a plurality of guides 17, which are disposed on guide stands 18, in each instance, and carry a mandrel bar 19, are provided in the rolling mill 4. The guides 17 are successively opened radially with regard to every guide stand 18, when a work piece, driven by way of the mandrel bar 19, reaches the guide stand 18, in each instance. The guides 17 are configured as round disks, whereby it is not absolutely necessary but might be practical if they can also roll, as rolls.

(8) Each of the rolling mills 1 to 4 comprises a center line 20 that ultimately corresponds to the intended pass-through center of a work piece to be rolled, such as, for example, of a pipe, a billet or a rod. To measure the gap, a camera 60 that is connected with an image processing apparatus 70 is placed on the center line 20 with its optical axis or also as defined in some other way, whereby ultimately, it is preferably important that the identical region of the camera 60 detects the center line 20 for each of the stands 10, 18, in each instance, within the scope of measurement accuracy. This has the advantage that no further adjustment measures of the camera 60 or complex and therefore error-prone correction calculations are then required. The latter is furthermore eliminated, in another respect, if the depth of field of the camera 60 is selected in such a manner that it reaches over all the stands 10, 18, because then, adjustments of the optical arrangement of the camera for focusing can also be eliminated. Sufficient depth of field is achieved if the image processing apparatus 70 or a corresponding computer program that runs there can determine a contour of the rolls 15, the guides 17 or also possible scales for each stand 10, 18, using the pictures taken, with sufficient accuracy.

(9) In the present exemplary embodiments, background lighting 55 is preferably provided on the output side, in each instance, in other words on the side opposite the camera 60, which radiates a sufficiently uniform light to the camera 60, so that the contours of the rolls 15 or guides 17 to be measured, in each instance, stand out clearly in front of the background lighting 55. Depending on the concrete embodiment, the background lighting 55 itself can have a scale position, which can take place by means of a hole or by means of a cover, for example, as shown in FIGS. 4 and 5 as an example. Likewise, a separate scale can be provided, which can be utilized as a reference scale. Corresponding scales are explained below, as examples, using FIGS. 1 to 3.

(10) A light plate, preferably with filter films or with LEDs, which might be collimated, and reduce the exit angle from the light plate in order to minimize scattered light, is particularly used as background lighting 55.

(11) In the exemplary embodiments shown in FIGS. 1 to 3, a scale that is configured by means of scale positions 46 in a reference plate, which is utilized as a comparison scale 40, serves as a reference scale. The comparison scale 40 can be displaced on a support 50, which is configured as a support tube 52 in this exemplary embodiment, proceeding from the background lighting 55 in the direction of the camera 60, toward all the roll stands 10 orif corresponding guides and guide stands, as they are explained using the rolling mill 4 in FIG. 5, are presenttoward all the guide stands 18, whereby this is implemented in essentially self-supporting manner, by means of a holder 53 provided in the region of the background lighting 55, whereby a separate holder 53 (see FIG. 3), which is disposed in front of or also behind the background lighting 55, can also be used, depending on the concrete implementation.

(12) A reference dimension can be made available, with relatively great precision, per stand 10, 18, by means of such a comparison scale 40, in each instance, so that the contour of a roll 15 or guide 17 that is determined can also be provided with known dimensions, accordingly. This then allows the image processing to make a statement concerning the precise position of the roll 15 or guide 17, in each instance.

(13) In alternative embodiments, particularly if such a separate comparison scale 40 is eliminated, a corresponding reference dimension can be calculated, for example, from the beam set and one or two scales that are pre-set on the input side or output side, in each instance. Thus, the scale positions 56 of the background lighting 55 can be used as a corresponding reference scale. Likewise, the rolls 15 of the first and last roll stand 10 or the guides 17 of the first and last guide stand 18 can serve as a reference dimension, for example, because these are generally more easily accessible from the outside. It is also understood that a comparison scale can be provided on the input side 12 or the output side 13, in each instance, which scale can be affixed there in some way, in sufficiently defined manner. Ultimately, a long support 50 that can reach through all the stands 10, 18 is not absolutely necessary for this.

(14) In order to facilitate alignment of the camera 60 and/or of the comparison scale 40, or to image the center line 20 in the camera 60 in simple manner, the rolling mills 1 and 2 in FIGS. 1 to 4 have reference means 30, in each instance, having a transmitter 35, which is configured as a laser in this exemplary embodiment. Possibly, LEDs, for example LEDs having different colors, or other kinds of markings, similar to the scale positions 46 and 56 can be used for this purpose. Likewise, rolls 15 or guides 18 that have already been measured with sufficient accuracy elsewhere could be used as reference means 30, for example in that they are suitably applied and then illuminated by the background lighting 55 as a transmitter for the reference means 30, in order to align the camera 60 with regard to the center line 20 in this manner. Likewise, other markers that can be applied to the stands 10 or 18 or other frames, such as, for example, on stand supports or fixed points in the building, can serve this purpose. Such markers can particularly be telescoping rods or bridges with bores or measurement brackets having measurement edges that represent the center line 20.

REFERENCE SYMBOL LIST

(15) 1 rolling mill 2 rolling mill 3 rolling mill 4 rolling mill 10 roll stand 12 input side 13 output side 15 roll (numbered as an example) 16 Diescher disk 17 guide (numbered as an example) 18 guide stand (numbered as an example) 19 mandrel bar 20 center line 30 reference means 35 transmitter for reference means 40 comparison scale 45 reference plate 46 scale position (numbered as an example) 50 support 52 support tube 53 holder 55 background lighting 56 scale position (numbered as an example) 60 camera 70 image processing apparatus