SENSOR ROLLER

Abstract

A sensor roller for determining planarity errors and/or for determining the tension of a strip tangentially engaging the roller has a roller body rotatable about an axis, having an outer surface, and formed with a plurality of radially outwardly open recesses axially spaced on the surface. Rigid sensor bodies each in a respective one of the recess each have an outer surface generally flush with the outer surface of the roller body. Each sensor body forms with a side surface of the respective recess a peripheral circumferentially fully extending gap. Respective force-measuring sensors in the recesses are each braced between a respective one of the sensor bodies and the roller body radially inward of the respective sensor body. An annular weld seam of welding compound is formed in each of the gaps

Claims

1. A sensor roller for determining planarity errors and/or for determining the tension of a strip tangentially engaging the roller, the roller comprising: a roller body rotatable about an axis, having an outer surface, and formed with a plurality of radially outwardly open recesses axially spaced on the surface; rigid sensor bodies each in a respective one of the recess, each having an outer surface generally flush with the outer surface of the roller body, and each forming with a side surface of the respective recess a peripheral circumferentially fully extending gap; respective force-measuring sensors in the recesses each braced between a respective one of the sensor bodies and the roller body radially inward of the respective sensor body; and an annular weld seam of welding compound in each of the gaps generally at the outer surfaces of the roller body and respective sensor body.

2. The sensor roller defined in claim 1, wherein the weld seam extends into the peripheral gap.

3. The sensor roller defined in claim 1, wherein the surface of the roller body at least in the region of the sensors is provided with a weld coating made by deposition welding and that covers the peripheral gaps.

4. The sensor roller defined in claim 3, wherein the hard coating overlies the weld seam and the outer surfaces of the roller and sensor bodies.

5. The sensor roller defined in claim 3, wherein the weld coating has a thickness of from 0.5 mm to 5 mm.

6. The sensor roller defined in claim 1, wherein an edge of the sensor body facing toward the respective gap at the outer surface of the roller body is beveled to form a chamfer.

7. The sensor roller defined in claim 1, wherein an edge of the roller body facing the gap at the outer surface of the roller body is beveled to form a chamfer.

8. The sensor roller defined in claim 1, wherein the weld seam in the gap has a depth of from 0.5 mm to 5 mm.

9. The sensor roller defined in claim 1, wherein the welding compound is of the same material as the roller body and/or the sensor body.

10. The sensor roller defined in claim 9, wherein the weld seam, roller body, and sensor bodies are of steel.

11. A method of making a sensor roller comprising the steps of: inserting into each of a plurality of radially outwardly open and axially spaced recesses of a roller body rotatable about an axis and having a substantially cylindrical outer surface a respective sensor body with an outer surface of each sensor body generally flush with the roller outer surface and each sensor body being peripherally and fully circumferentially spaced by a peripheral gap from an inner surface of the respective recess; providing radially between each sensor body and a floor surface of the respective recess a piezoelectric force-measuring sensor; and forming at the surfaces in the gap between the sensor bodies and the roller body a weld seam of welding compound closing the gap and angularly and axially supporting the sensor bodies in the respective recess while permitting limited radial movement of the sensor bodies in the respective recesses.

12. The method defined in claim 11, wherein the weld seam is introduced into the peripheral gap and/or the outer surface of the roller body is provided with a weld coating of the welding compound by deposition welding that covers the peripheral gap.

13. The method defined in claim 11, further comprising the step of: beveling an edge of the sensor body facing toward the gap to form a chamfer before formation of the weld seam, or beveling an edge of the roller body facing toward the gap to form a chamfer before formation of the weld seam.

14. The method defined in claim 13, wherein both edges are beveled and the weld seam is made of triangular cross section.

15. The method defined in claim 11, further comprising the step of: forming a hard coating over the welding compound.

16. The method defined in claim 15 wherein the hard coating is formed by thermal spraying.

17. The method defined in claim 15, wherein the hard coating is applied to the entire outer surface of the roller body as well as the outer surfaces of the sensor bodies.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0034] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0035] FIG. 1 is a simplified radial view of a sensor roller for determining and/or monitoring the planarity of a strip,

[0036] FIG. 2 is a section through the sensor roller according to line II-II of FIG. 1,

[0037] FIG. 3 is a section through the sensor roller according to line FIG. 2,

[0038] FIG. 4 is a section through the object according to line A-A of FIG. 1 of a second embodiment of the invention, and

[0039] FIG. 5 is a section through the sensor roller according to line V-V of FIG. 4.

SPECIFIC DESCRIPTION OF THE INVENTION

[0040] As seen in the drawing, a sensor roller 1 that serves as a planarity-sensor roller for determining and/or monitoring planarity errors and/or the planarity of a strip, particularly of a metal strip is rotatable during operation about a normally horizontal axis R, although it is not normally driven. It can for example be part of a strip-treatment or strip-processing line where the strip passes horizontally above and perpendicular to the roller axis R. The unillustrated strip is under a predetermined tension over its entire width and therefore tensioned, and wraps around the planarity-sensor roller at a predetermined small wrap angle that can for example be 2 to 10. The determination of the strip planarity and/or the identification of planarity errors is done indirectly using the sensor roller 1 by measuring the of tension at a plurality of locations spaced transversely across the width of the strip, that is perpendicular to the horizontal strip-travel direction and to a vertical plane including the roller rotation axis R.

[0041] For this purpose, the sensor roller 1 has a roller body 2 and a plurality of sensors 3 distributed over the cylindrical roller outer (or peripheral) surface axially and/or angularly and integrated into the roller body 2. Each of these sensors 3 has a sensor body 4 that is flush with the roller body 2 and fits in a respective radially outwardly open recess 5 in the roller body 2, so as to form a peripheral gap 6 between the sensor body 4 on the one hand and the roller body 2 on the other. The sensors 3 are set in the respective recesses 5 on one or more piezoelectric force-measuring sensors 7. In the illustrated embodiment, the sensor bodies 2 are pressed against the roller body 2 by for example mounting screws 8 to cover and press the sensors 7 radially inward against the floors of the respective recesses 5. Alternatively, however, bracing with tie rods in a manner known per se can also be considered, in which case two sensors diametrally opposite one another and exposed at the surface of the roller can be braced against one another using tie rods. The roller body 2 is also provided with through holes 14 under the sensor body 4, for example for passing connector cables through to the sensors 7. Such cables lead off to a monitoring computer.

[0042] The drawing shows embodiments in which the sensors 4 are elongated and extend with their longitudinal direction running in the strip travel direction and angularly of the roller surface when seen in a view of the roller surface radially perpendicular to the roller axis R, with it being possible for a plurality of measurements to be made by the sensors 3 for each revolution of the roller for the respective axial or transverse position on the roller body 2. In the illustrated embodiments, the individual sensors 3 are thus correlated with individual axial positions, so that a measurement is performed with each individual measuring bar 4 at a specific axial position of the metal strip, thereby realizing a solution according to U.S. Pat. No. 9,784,574.

[0043] According to the invention, the peripheral gap 6 is sealed or covered with a welding compound.

[0044] In this regard, FIGS. 2 and 3 show a first embodiment in which a peripheral weld seam 9 made of the welding compound is introduced into the radial outer edge of the peripheral gap 6. The edge of the sensor body 4 facing toward the gap 6 is beveled in order to form a first chamfer 11. Furthermore, in the illustrated embodiment, the edge of the roller body 2 facing toward the gap is beveled in order to form a second chamfer 12. These chamfers 11, 12 serve as preparation for the triangular-section weld seam 9 that seals the peripheral gap 6 near the surface of the roller body before the welding compound is applied. A completely closed roller surface is thus formed by this weld seam 9 that allows flawless measurements to be made without damaging the metal strip. In the illustrated embodiment, a radial depth T along the depth of the gap is for example from 1 mm to 3 mm.

[0045] After formation of the weld seam 9, it is advantageous to polish the roller surface during manufacture of the sensor roller shown in the drawing. It is then possible to optionally apply a completely closed shell to the surface of the roller body 2 (including the surface of the sensor body 4) in the form of a hard coating 13 that can for example be done by thermal spraying and has for example a thickness of only 0.05 mm to 0.2 mm.

[0046] FIGS. 4 and 5 show a second embodiment of the invention where the surface of the roller body 2 is provided at least in the region of the sensors 3, but preferably over the entire surface, with a weld coating 10 of the welding compound that is made by deposition welding and covers the peripheral gap 6. In this embodiment, the radial thickness D of this weld coating 10 can for example be 1 mm to 3 mm. In this embodiment as well, it is advantageous for the roller surface to be polished after application of the weld coating 10. Again, a hard coating 13 can then be optionally applied in the manner described above. In any case, in the embodiment according to FIGS. 4 and 5 as well, the peripheral gap is sealed by a very thin cover layer of the welding compound to form a closed roller surface without falsification of the measurement results due to force deflection.

[0047] The figures show an embodiment with sensors that extend perpendicular to the roller axis. However, the invention can be implemented in equal measure in other known embodiments, such as those with singular, round sensors or with measuring bars that extend for example oblique to the roller axis. Furthermore, the invention can also be implemented in connection with a tension-measuring bar such as that known for example from U.S. Pat. No. 8,132,475 where the sensor roller can also determine the tension of a strip.