US20110318991A1

US20110318991A1 - Method and device for honing metal strips of arbitrary width in continuous motion

Info

Publication number: US20110318991A1
Application number: US13/126,230
Authority: US
Inventors: Gaël Imbert; Jean-Pierre Rivollier; Anne-Marie Rivollier; Alexandra Teissier; Arnaud Rivollier
Original assignee: Siemens VAI Metals Technologies SAS
Current assignee: Clecim SAS
Priority date: 2008-10-27
Filing date: 2008-10-27
Publication date: 2011-12-29
Also published as: EP2349641A1; CN102196885A; BRPI0823205A2; RU2492039C2; RU2011121358A; WO2010049596A1

Abstract

A method and device for honing a metal strip of arbitrary width in continuous motion, allow honing of a suspended portion of at least one side of a metal strip, being free of artifacts and automated. The device includes a device for vertically positioning an abrasive element at the surface of the strip. A device for horizontally moving the abrasive element transversely to the motion of the strip can be coupled to the vertical-positioning device and moved back and forth from one edge of the strip to the other. A first device allows uniform pressure to be applied to press the abrasive element against the strip. The first device allows a uniform pressure to be applied to a suspended portion of the strip in motion and can be coupled to a second device allowing the pressure to be adjusted according to the longitudinal tension of the suspended portion of strip.

Description

The present invention relates to a method and a device for honing suspended metal strips of arbitrary width and in continuous motion, according to the preambles of claims 1 and 13.
In particular, the invention relates to automated honing based on a selective abrasion technique for revealing surface defects of cold rolled metal strips, said honing being carried out on continuously moving suspended metal strips being processed in a processing plant.
Rolled metal strip processing plants such as e.g. cold rolling mills or continuous coating lines may produce, on the surface of the strips, defects resulting in rejects or expensive downgradings. These defects are essentially the result of rolling operations, even with slight thickness reduction as in the case of skin-pass rolling, or of foreign body indentations when the strips are subject to traction on tensioner or deflector rollers. In all cases, the marks produced on the strip are cyclic in nature and recur on each revolution of the roll or roller.
In order to be able to detect and assess such defects quickly and eliminate their causes, it is customary to carry out a visual inspection of one or both sides of a portion of strip of sufficient length to show up any cyclic defects. Said length is generally selected as a function of the longest step of the cycle, e.g. the design length of the work rolls of the first rolling stand multiplied by the reduction in thickness, or else the design length of the largest tensioner or deflector roller.
The honing technique, which consists of rubbing an abrasive stone over the strip surface, allows discrete defects to be revealed that are difficult to detect by visual inspection even using oblique light. As a result of honing, the most raised-up parts such as, for example, wave peaks, indentation burrs, or scale, undergo slight abrasion which suffices, by contrast, to make them more easily detectable by visual inspection.
This honing operation is generally performed manually by an operator who has to move across the entire width of the strip (which may be as much as two meters wide) and along the entire length of the sample (ranging from 5 to 15 meters as the case may be). As these movements have to be performed with the greatest of care so that they do not themselves cause defects, the operators proceed on their hands and knees. Such an operation is only possible if the portion of strip to be inspected is stationary. Its use is therefore limited to dedicated inspection lines and to samples inspected off-line. On the other hand, it requires the strip to be resting on a support such as a table or a conveyor which may, in certain cases, create “false defects” due to the reaction of the support to the honing of the strip.
A device for automating an inspection by honing of a continuous steel strip surface is disclosed in KR2003-0077104. Said device comprises among other things:

- a means of horizontally displacing an abrasive element transversely to the rolling direction of the strip, said means being capable of moving the abrasive element back and forth from one edge of the strip of fixed width to the other,
- a means of enabling the abrasive element to apply uniform pressure to the metal strip supported by a system of rollers.

However, the present invention does not relate to honing performed for a metal strip of fixed width and supported by a system of rollers, but, on the contrary, to honing for a strip of arbitrary width that is applied to a portion of strip suspended between at least two modules of a processing plant. Moreover, the device according to KR2003-0077104 is an installation dedicated to inspecting metal strips after processing of the strip, whereas the present invention applies to strips in the course of processing in a processing plant.
One object of the present invention is to propose an artifact-free and automated method of honing at least one side of a continuously moving metal strip for which said honing is performed on a suspended portion of strip, e.g. between two metal rollers supporting the strip.
Another object of the invention is to allow said honing to be performed over a maximum surface of a metal strip of arbitrary width during processing in a processing plant.
In order to be able to implement the method according to the invention, it is also intended to propose a honing device.
To this end, a device and a method are set forth in claims 1 and 13.
Based on a method for honing at least one side of a continuously moving metal strip, said honing being designed to increase the surface roughness in a contact zone defined by contact of an abrasive element with the strip, and comprising the following steps:

- placing of the abrasive element in contact with the metal strip,
- motorized alternating transverse displacement of the abrasive element in contact with the strip, said transverse movement being perpendicular to the rolling direction of the strip and fixed with respect to the motion of the strip,
- abrasive element pressure limited to a portion of strip throughput,
  the method according to the invention comprises a variable adjustment of said pressure as a function of a longitudinal tension of the suspended portion of strip of arbitrary width.

In particular, the method according to the invention is characterized in that the honing is performed for a specified duration for a strip of arbitrary width in the course of processing in a processing plant. The duration of honing can advantageously be linked to the time interval separating the appearances of a cyclic defect; in particular, this duration can be determined as a function of the roller or rollers having the lowest angular speed of the processing plant, in order to assess defects possibly resulting from any other roller having a higher angular speed. Another advantage relating to controlling the honing duration is the ability to identify which element of the processing plant is the cause of the defect using a deconvolution process based on the honing duration and the position of the defect on the abraded portion of strip.
On the other hand, the method according to the invention advantageously relates to metal strips of arbitrary width. Indeed, the method according to the invention is characterized by transverse movement of the abrasive element matched to the arbitrary width of the strip by detecting the edges of the strip in its transverse direction. Said detection enables limits to be placed on the transverse movement of the abrasive element. Said detection can take place continuously as the strip moves through in the course of processing but also, simply, at the start of a honing cycle or at roll-in of a new strip. The strip width would thus be memorized (recording of the abscissae of the strip edges) at the start of the honing operation and for its entire duration. At the end of a honing cycle, or when a new strip is rolled in, a new strip width measurement can be performed automatically.
The method according to the invention is also characterized in that the establishment of contact is effected from at least one idle position to at least one operating position of the abrasive element. Said idle position advantageously ensures that the abrasive element can be safely accessed by an operator. Indeed, this is an off-line position, outside the reach of the strip, which allows e.g. visual inspection of the abrasive element, or even rapid manual/automated changing of the abrasive element if the degree of wear exceeds a threshold value. The actual operating position of the abrasive element is above the strip, characterized by at least one in-contact state of the abrasive element with the strip, as well as at least one out-of-contact state of the abrasive element above the strip. Ideally, a horizontal transfer allows the abrasive element to be moved from its idle position to its operating position above the strip, preferably in the center axis thereof. A vertical transfer then allows the abrasive element to go from an out-of-contact state to an in-contact state with the strip, said in-contact state permitting abrasion work proper to be carried out by the abrasive element in contact with the strip.
In this context, the method according to the invention is characterized in that the pressure is adjustable in the idle position or/and in the operating position. This makes it possible, for example, to preset the honing operation for metal strips of known characteristics in the idle position, but also to adjust the pressure in the course of honing in the operating position when the strip characteristics are new. In particular, the method according to the invention is characterized by a pressure adjustable as a function of the longitudinal tension of the strip by adding at least one constraint to a vertical degree of freedom of the abrasive element. A simple example of constraint would be in this case an addition of at least one mass to a mechanism allowing vertical displacement of the abrasive element. Another example would be a manual/automated biasing of at least one spring involved in the application of the pressure of the abrasive element to the surface of the strip. Adjusting this pressure would advantageously enable a quality of contact with the surface of the strip to be maintained that is close to human practice, with a honing force ideally varying between 5 and 50 N for a surface of 150×50 mm.
The method according to the invention is also characterized in that a correlation between a rolling speed of the strip and a transverse movement speed of the abrasive element regulates the movement of the abrasive element. In particular, the transverse movement speed of the abrasive element is defined as a function of a contact zone geometry, a strip geometry and the rolling speed of the strip. Ideally, in the case of a rectangular shaped abrasive element of length (Lp) in the rolling direction of the strip and of width (lp), the transverse movement speed is fixed to a value equal to the quotient [Vb·(lb−2r−lp)]/Lp, defined by a width (lb) of the strip, the rolling speed (Vb) of the strip and a setback distance (r) of an edge of the strip with respect to a parallel and nearest edge of the abrasive element at each extremity of its transverse movement. This correlation advantageously allows honing of the entire surface of the strip included at a setback distance (r) from the strip edges. In addition, the method according to the invention advantageously includes adjusting the rolling speed (Vb) of the strip in at least part of the processing plant as a function of the transverse movement speed of the abrasive element. This characteristic allows the rolling speed of the strip to be adapted to the capabilities of the honing device and/or vice versa.
In this context, the method according to the invention is in particular characterized in that initiation of the honing method and the duration of honing are configured as a function of an availability and a total or residual storage capacity of at least one strip accumulator device located upstream of the abrasive element in the processing plant with respect to the rolling direction of the strip. Indeed, in the case where, for example, the transverse movement speed of the honing tool would not allow the entire width of the strip to be swept in time with the rolling speed of the strip in the processing plant, it would then be necessary to reduce the speed of the strip in the honing zone via the strip accumulator device. A bidirectional exchange of information between at least one accumulator device, a plant monitoring unit and a honing device monitoring unit can advantageously allow manual or even automatic configuration and/or manual or even automatic adjustment of the parameters ensuring an effective and functional honing operation.
In particular, the method according to the invention is characterized in that an exceedance of a wear threshold of the abrasive element is detected, indicated and capable of causing honing to be interrupted. Ideally, in the event of said interruption, the abrasive element is moved vertically out of contact with the strip, then horizontally to its idle position where, for example, an operator could safely check the state of wear of the abrasive element and replace it if necessary. In the case of complete automation of the honing method, the replacement of the abrasive element could be automated and, in particular, linked to the strip accumulator device in order to slow down the throughput of the strip in the course of processing while the worn abrasive element is replaced. The underlying advantage of the method is, on the one hand, that of not interrupting the processing of the strip when replacing the abrasive element, and also, on the other hand, that of minimizing the unhoned surface by reducing the rolling speed of the strip in the case of linkage with a strip accumulator device.
The method according to the invention is further characterized in that honing is performed upstream of a visual inspection station. This can be, for example, a purely visual inspection, or even a visual inspection aided by video scanning. The assessment, or even the result, of said inspection can be, for example, directly reflected in the operation of the processing plant, requiring e.g. an interruption of the processing of the strip, or its slowing down (via accumulation of the strip in an accumulator device), or even checking of some of the elements of the processing plant in direct contact with the strip, in order to determine the cause of the strip defects observed at the time of inspection and to eliminate them.
Based on a device for honing at least one side of a continuously moving metal strip, comprising:

- a means of vertically positioning an abrasive element at the surface of said strip,
- a means of horizontally displacing the abrasive element transversely with respect to the motion of the strip, said means being linkable to the vertical positioning means and capable of effecting an alternating movement from one edge of the strip to the other,
- a first means allowing a uniform pressure of the abrasive element to be applied to the metal strip,
  the device according to the invention is characterized in that said first means allows a uniform pressure to be applied to a suspended portion of moving strip of arbitrary width, and can be linked to a second means allowing said pressure to be adjusted as a function of the longitudinal tension of the suspended portion of strip.

In particular, the device according to the invention is characterized in that said honing device can be incorporated in a processing plant for metal strips of arbitrary width in order to perform said honing for a specified duration on a strip undergoing processing. Combined with a visual inspection station, e.g. observation of strip defects by an operator, with or without the aid of video scanning means, the honing device obviates the need for space-occupying ancillary equipment dedicated specifically to inspection (by honing) of processed metal strips. In addition, as it performs real-time honing on a strip in the course of processing, the device has the advantage of reducing the reaction time before the observation of defects in a metal strip, thereby allowing, for example, the amount of rejects of strip not compliant with rolling tolerances to be reduced, and providing cost and material savings.
In addition, the device according to the invention is characterized in that said horizontal displacement means allows the abrasive element to be moved from at least one idle position to at least one operating position, said idle position being located out of range of the strip in order to enable the abrasive element to be safely serviced by an operator, and said operating position being located above the strip and including at least one state in which the abrasive element is in contact with the strip, as well as at least one state in which the abrasive element is out of contact with the strip. The idle position, off-line, of the abrasive element allows an operator to check its state with absolute safety, but also to monitor at least part of the horizontal displacement means. These operations, checking and/or monitoring, have the advantage of being implemented without disturbing the processing of the strip.
In particular, the device according to the invention is characterized in that said horizontal displacement means comprises at least one horizontal carriage capable of moving transversely with respect to the strip over a distance greater than the width thereof and including said idle and operating positions. Said vertical positioning means comprises at least one vertical transfer unit disposed between the carriage and a tool holder, said tool holder having a fixed vertical position during honing and supporting the first and second pressure applying means. Ideally, the vertical transfer unit comprises at least one jack acting on a set of hinged rods arranged in a deformable parallelogram.
The device according to the invention is in particular characterized in that said first pressure applying means comprises at least one tool mounting plate supporting the honing element and incorporated in said tool holder by means of at least one vertical slide in which the tool mounting plate can slide freely. The first pressure applying means allows the abrasive element to be placed in contact with the strip, while the second pressure applying means allows said pressure to be adjusted to the longitudinal tension of the portion of strip. This honing device is therefore characterized by an adjustable pressure that can be supported solely by the tension of the strip as it passes, for example, between at least two devices capable of supporting the strip, such as e.g. a tensioner or deflector device upstream of honing and a downstream coiler device. The advantage of such a device is the prevention of artifacts due to honing performed on a strip resting on a support such as a table, a conveyor or rollers. Indeed, the resting of the strip on a support during honing generally creates false defects due to the reaction of the support to the honing of the strip. Moreover, automatic honing is less onerous for the operator who can then concentrate on the strip processing quality.
In particular, the device according to the invention is characterized in that a detection system detects the edges of the strip and transmits a signal reporting said detection to the horizontal displacement means in order advantageously to adapt said movement of the abrasive element to the arbitrary width of the strip. Ideally, the horizontal movement is limited to a travel of a value equal to (Lb)−((lp)+(2r)), defined by a difference between the strip width (Lb) and the sum of a width (lp) of the abrasive element and a distance (2 r) equal to twice a setback distance (r) of an edge of the strip in relation to a parallel and nearest edge of the abrasive element at each extremity of its transverse movement. The detection system can in particular continuously measure the strip width on a strip in the course of processing, but also at the beginning of a honing cycle of a specified duration, or at the start of a strip, or even on demand following an operator decision. Ideally, said detection system comprises at least one detector, in particular a contactless remote detector, capable of detecting the edges of the strip during the transverse movement of the abrasive element, said detector being incorporated in an element having a fixed vertical position during honing and forming part of the vertical positioning means. Advantageously, said element having a fixed vertical position can be the tool holder.
In addition, the device according to the invention is characterized in that the second pressure applying means comprises at least one detector, in particular a contactless remote detector for detecting the horizontal level of the abrasive element, said detector being incorporated in an element having a fixed vertical position during honing and ideally forming part of the vertical positioning means. Said detection in particular provides a simple means of monitoring abrasive element wear by comparing the horizontal level measured with a threshold value characterizing a reference level. Ideally, a detection system detects and signals abrasive element wear approaching the threshold value, and, if necessary, interrupts honing if said threshold value is exceeded. In particular, in the event of honing being interrupted because of abrasive element wear, said abrasive element returns to its idle position where it will be exchanged for a new abrasive element, either manually by an operator or in an automated manner.
In particular, the device according to the invention is characterized in that an adjustment system correlates a rolling speed of the strip with a transverse movement speed of the abrasive element in order to adapt (automatically) the rolling speed of the strip to the honing capability of the honing device in at least part of the processing plant. Ideally, said adjustment is characterized by at least one exchange of at least one adjustment signal between a monitoring system of the plant and said honing device. Advantageously, the adjustment system would allow, for example, the rolling speed of the strip to be reduced using a strip accumulator device upstream of honing in order to permit detailed visual inspection of the strip or changing of a worn-out abrasive element.

Finally, an exemplary embodiment and application will be described with reference to the accompanying drawing in which:

FIG. 1 shows an exemplary embodiment of the device for honing a suspended strip of arbitrary width.

By way of example, FIG. 1 shows a device (7) for honing at least one side of a continuous suspended metal strip (1), comprising:

- a means (73) of vertically positioning an abrasive element (71) on the surface of said strip,
- a means (74) of horizontally moving the abrasive element (71) transversely to the motion of said strip, said means (74) being linkable to the vertical positioning means (73) and capable of effecting an alternating movement from one side of the strip to the other,
- a first means (72) of applying uniform abrasive element pressure to the metal strip,
  characterized in that said first means (72) allows a uniform pressure to be applied to a suspended portion of moving strip and can be linked to a second means (75) for adjusting said pressure as a function of the longitudinal tension of the suspended portion of strip.

In particular, the horizontal displacement means (74) comprises a horizontal carriage capable of moving transversely with respect to the strip over a distance greater than the width thereof and including an idle and an operating position. The vertical positioning means (73) comprises a vertical transfer unit (732) disposed between the carriage and a tool holder (731), said tool holder having a fixed vertical position during honing and supporting the first (72) and second (75) pressure applying means. The first pressure applying means (72) comprises a tool mounting plate (721) supporting the honing element and incorporated in said tool holder (731) by means of at least one vertical slide (722) in which the tool mounting plate can slide freely. An in-contact operating position of the abrasive element on the surface is illustrated by the honing device (7), whereas the honing device (8) illustrates an operating position of the abrasive element out of contact with the strip.
In short, the method and the device according to the invention offer several advantages compared to the existing methods and devices in that:

- they provide automated honing, free of artifacts caused by a strip support positioned below the abrasive element,
- they provide honing over a portion of strip suspended below the abrasive element, said portion of strip being held taut between at least one module upstream and one module downstream of the abrasive element,
- they require little space as no other equipment is necessary for uncoiling/coiling a strip in an ancillary inspection-by-honing station,
- they allow the pressure of the abrasive element on the surface of the strip to be adjusted as a function of the longitudinal tension of the suspended portion of strip,
- they allow safe monitoring of the state of the abrasive element by an operator,
- they allow honing to be performed on a strip in the course of processing, as well as enabling at least part of the honing device to be monitored or maintained while the abraded strip is undergoing processing, thereby minimizing the effect on the throughput of the strip,
- they allow the transverse movement of the abrasive element to be adapted to arbitrary strip widths,
- they make it possible, in at least one part of the processing plant, to adapt the rolling speed of the strip to the honing capabilities of the honing device, in particular to correlate the rolling speed of the strip and the transverse movement speed of the abrasive element, in order to implement e.g. honing that will allow reliable inspection of the strip defects,
- they allow honing of a specified duration and pressure to be performed for a strip in the course of processing,
- they reduce costly strip downgradings by allowing strip defects to be corrected quickly,
- they provide, sequentially, the motorized horizontal displacement of the honing element from an idle position to an operating position above the strip, the motorized vertical displacement of the honing element from its operating position above the strip to its operating position in contact with the strip, an alternating transverse movement of the abrasive element from one edge of the strip to the other for a specified duration and between two limits of travel fixed by a strip edge detection system, vertical displacement of the abrasive element out of contact with the strip e.g. at the end of the honing period, and finally, returning of the abrasive element to its idle position by horizontal displacement from its operating position above the strip.

Claims

1-23. (canceled)

24. A method for honing at least one side of a continuous metal strip to increase surface roughness in a contact zone defined by contact of an abrasive element with the strip, the method comprising the following steps:

placing the abrasive element in contact with the metal strip;

motorized alternatingly transversely displacing the abrasive element in contact with the strip with a transverse movement perpendicular to a rolling direction of the strip and fixed relative to a motion of the strip;

applying pressure to the abrasive element limited to a portion of a throughput of the strip; and

variably adjusting the pressure as a function of a longitudinal tension of a suspended portion of the strip.

25. The method according to claim 24, which further comprises carrying out the honing for a specified duration on a strip of arbitrary width in a course of processing in a processing plant.

26. The method according to claim 24, which further comprises:

adapting the transverse movement of the abrasive element to the arbitrary width of the strip by detecting edges of the strip in its transverse direction;

setting transverse movement limits using the detection; and

performing the detection at a start of a honing cycle.

27. The method according to claim 24, which further comprises:

providing the contact by moving the abrasive element from at least one idle position to at least one operating position;

providing an operator with safe access to the abrasive element in the idle position; and

providing at least one in-contact state of the abrasive element with the strip as well as one out-of-contact state of the abrasive element above the strip in the operating position.

28. The method according to claim 27, which further comprises adjusting the pressure in at least one of the idle position or the operating position.

29. The method according to claim 24, which further comprises adjusting the pressure as a function of the longitudinal tension of the strip by adding at least one constraint to a vertical degree of freedom of the abrasive element.

30. The method according to claim 29, which further comprises carrying out the step of adding the at least one constraint by an addition of at least one mass to a mechanism allowing the abrasive element to be displaced vertically.

31. The method according to can 24, which further comprises regulating the displacement of the abrasive element by a correlation between a rolling speed of the strip and a transverse movement speed of the abrasive element.

32. The method according to claim 24, which further comprises defining a transverse movement speed of the abrasive element as a function of a contact zone geometry, a strip geometry and a rolling speed of the strip.

33. The method according to claim 32, which further comprises fixing the transverse movement speed of a rectangularly shaped abrasive element with a length Lp in the rolling direction of the strip and a width lp, to a value equal to a quotient [Vb·(lb−2r−lp)]/Lp, defined by a width lb of the strip, the rolling speed Vb of the strip and a setback distance r of an edge of the strip relative to a parallel and nearest edge of the abrasive element at each extremity of its transverse movement.

34. The method according to claim 33, which further comprises adjusting the rolling speed of the strip in at least part of a processing plant as a function of the transverse movement speed of the abrasive element.

35. The method according to claim 24, which further comprises:

providing at least one strip accumulator device upstream of the abrasive element in a processing plant relative to the rolling direction of the strip; and

determining an initiation of the honing method and a duration of honing as a function of an availability and storage capacity of the at least one strip accumulator device.

36. The method according to claim 24, which further comprises detecting and signaling an exceeding of a wear threshold of the abrasive element for causing honing to be interrupted.

37. The method according to claim 24, which further comprises performing the honing upstream of a visual inspection station.

38. A device for honing at least one side of a continuously moving metal strip, the device comprising;

an abrasive element;

a device for vertically positioning said abrasive element at a surface of the strip;

a device for horizontally displacing said abrasive element transversely to a motion of the strip, said horizontal displacing device configured to be linked to said vertical positioning device and configured to be capable of effecting an alternating movement from one side of the strip to another;

a first device for allowing a uniform abrasive element pressure to be applied to a moving suspended portion of the strip; and

a second device configured to be linked to said first device for allowing the pressure to be adjusted as a function of a longitudinal tension of the moving suspended portion of the strip.

39. The device according to claim 38, wherein the honing device is configured to be incorporated in a processing pant for metal strips of arbitrary width in order to perform honing for a specified duration on a strip in a course of processing.

40. The device according to claim 38, wherein:

said horizontal displacement device allows the abrasive element to be moved from at least one idle position to at least one operating position;

said idle position is located out of range of the strip in order to allow the abrasive element to be safely maintained by an operator; and

said operating position is located above the strip and includes at least one state in which the abrasive element is in contact with the strip as well as at least one out-of-contact state of the abrasive element above the strip.

41. The device according to claim 40, wherein:

said horizontal displacement device includes at least one horizontal carriage capable of moving transversely relative to the strip over a distance greater than a width of the strip including said idle and operating positions;

said vertical positioning device includes a tool holder and at least one vertical transfer unit disposed between said carriage and said tool holder; and

said tool holder has a fixed vertical position during honing and supports said first and second pressure applying devices.

42. The device according to claim 41, wherein said at least one vertical transfer unit includes at least one jack actuating a set of hinged rods disposed in a deformable parallelogram.

43. The device according to claim 38, wherein said first device for applying pressure includes at least one tool mounting plate supporting said abrasive element and at least one vertical slide incorporating said at least one tool mounting plate in said tool holder, said at least one tool mounting plate configured to freely slide in said at least one vertical slide.

44. The device according to claim 38, which further comprises a detection system detecting edges of the strip and transmitting a signal reporting the detection to said horizontal displacement device for adapting a displacement of the abrasive element to an arbitrary width of the strip.

45. The device according to claim 44, wherein the horizontal displacement is limited to a travel having a value equal to Lb−(lp+2r), defined by a difference between a strip width Lb and a sum of a width lp of the abrasive element and a distance 2 r equal to twice a setback distance r of an edge of the strip with respect to a parallel and nearest edge of the abrasive element at each end of its transverse movement.

46. The device according to claim 44, wherein said detection system includes at least one detector capable of detecting the edges of the strip during the transverse movement of the abrasive element, said detector being incorporated in an element having a fixed vertical position during honing and forming part of said vertical positioning device.

47. The device according to claim 38, wherein said second pressure applying device includes at least one detector for detecting a horizontal level of the abrasive element, said detector being incorporated in an element having a fixed vertical position during honing.

48. The device according to claim 38, which further comprises a detection system detecting and signaling abrasive element wear approaching a threshold value and interrupting honing if said threshold value is exceeded.

49. The device according to claim 38, which further comprises an adjustment system correlating a rolling speed of the strip with a transverse movement speed of the abrasive element for adapting the rolling speed of the strip to honing capabilities of the honing device in at least part of a processing plant.