EP1917113B1 - Inspection method - Google Patents

Inspection method Download PDF

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Publication number
EP1917113B1
EP1917113B1 EP06794198A EP06794198A EP1917113B1 EP 1917113 B1 EP1917113 B1 EP 1917113B1 EP 06794198 A EP06794198 A EP 06794198A EP 06794198 A EP06794198 A EP 06794198A EP 1917113 B1 EP1917113 B1 EP 1917113B1
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EP
European Patent Office
Prior art keywords
strip
length
inspection
rolling
pass
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
EP06794198A
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German (de)
French (fr)
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EP1917113A1 (en
Inventor
Jean Perret
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Clecim SAS
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Siemens VAI Metals Technologies SAS
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Publication of EP1917113A1 publication Critical patent/EP1917113A1/en
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/30—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process
    • B21B1/32—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process in reversing single stand mills, e.g. with intermediate storage reels for accumulating work
    • B21B1/36—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a non-continuous process in reversing single stand mills, e.g. with intermediate storage reels for accumulating work by cold-rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B13/00—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories
    • B21B13/02—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories with axes of rolls arranged horizontally
    • B21B2013/025—Quarto, four-high stands
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B15/00—Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B2015/0057—Coiling the rolled product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B15/00—Arrangements for performing additional metal-working operations specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B2015/0064—Uncoiling the rolled product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2261/00—Product parameters
    • B21B2261/02—Transverse dimensions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B38/00—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product
    • B21B38/02—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring flatness or profile of strips

Definitions

  • the invention relates to rolling mills. More particularly, the subject of the invention is a method and an installation for inspecting the quality of a sheet metal strip after rolling.
  • the laminated sheet metal strip may have certain appearance defects which may be due, for example, to a slight variation in thickness in the transverse direction, resulting from the deformation and the wear of the rolls and / or the cedar cage, or marks left by the working rolls, some defects may also be due to the support rolls or the cage itself.
  • the length of inspection corresponds to the period of the marks produced in the cage furthest upstream, from which band undergoes the greatest elongation by passing into the following cages.
  • the inspection can be done in a particular installation where are made some reels to inspect, after their production by the rolling mill.
  • the inspection facility includes an inspection and a horizontal table for unrolling a length of product corresponding to the length of inspection, on which the operator can perform the observation, the tracking, the layout or any another operation to take into account the marks on both sides of the sample used for the inspection.
  • Such an inspection facility is expensive to produce and also to operate. Indeed, it is necessary to remove a reel from the produced batch, to convey it towards the inspection facility, then to inspect it before continuing its routing. However, the rolling mill continues to produce during the inspection of a rolled strip sample, and the detection of a large defect then results in the rolled sheet strips produced in the gap being subsequently discarded.
  • the winding installation usually comprises at least two cores operating alternately, for example on a carousel-type winder, and the band is cut in flight, at the end of the winding on a mandrel, to continue winding on another mandrel. Two successive cuts can then be made which are spaced so as to take an inspection length, which is then conveyed to an inspection table by means of switching and drive systems. This length of inspection has undergone all rolling stages, as the rest of the band and its surface condition is therefore well representative of that of the band.
  • Such a method is, however, not applicable to a reversible rolling mill comprising at least one rolling stand disposed between two winder / unwinder devices between which the band alternately circulates in one direction and the other each winder device / unwinder serving, according to the direction of rolling, the winder downstream of the upstream rolling and uncoiling shaft.
  • the rolling is not continuous, it is not useful to have a carousel winder, with cutting theft of the tape.
  • the downstream winder at the end of the last pass, can be placed on one side or the other of the rolling mill.
  • the length of inspection is simply taken on the band at the end of the last pass, on one side or the other of the rolling mill.
  • this length of service used to tension the strip consists of an extension welded to each end of the strip. This can then be rolled practically over its entire length, but the welding of the two extensions and their removal takes a certain time and decreases the productivity of the installation.
  • the coil is of great length, it seems It is preferable to sacrifice at each end of the strip a service length which is not rolled to the desired thickness and must therefore be discarded.
  • such a reversible rolling plant comprises, in addition to the two devices winder / unwinder, a so-called "first pass" unwinder capable of taking coils wound on themselves and without traction.
  • a coil being placed on the first pass unroller the product is unrolled from it in a first direction of travel, by passing his head in the cage to engage on the device winder / unwinder placed of the other side of the cage and thus serving, of coiler.
  • the product is then wound almost completely on this winder until its end, forming the tail of the strip, leaves the unroller, this first pass being made, therefore, without rolling.
  • the rolling can then be performed alternately in one direction and the other between the two winders / unwinders that serve, alternately, winder and uncoiler, but, to maintain each pass the tension necessary for rolling, it is necessary to keep on each mandrel a length of service that is not laminated. At the end of the last pass, it is necessary to eliminate the length of service at the tail of the tape and which do not have the required qualities. Similarly, the service length at the head of the strip and wound inside the coil, should be eliminated at the end of the course of the latter.
  • a rolled coil is therefore laminated to the desired thickness only on a central useful portion framed by two non-rolled service lengths, which represent a loss called "put to the mile".
  • this inspection loss usually has to be added to the length of inspection which is taken from the useful part of the strip having the required qualities. Such an inspection process therefore increases the feathering.
  • the object of the invention is to overcome these drawbacks in a reversible rolling mill by means of a new method allowing an on-line inspection while maintaining a high production yield, the rejected length not exceeding the two lengths of service which must remain wound. on each mandrel and therefore do not have the required thickness.
  • the invention also covers a rolling plant for carrying out the method.
  • the invention therefore applies, in a general manner, to a reversible rolling installation, comprising at least one rolling stand disposed between two reel / unwinder devices each having a mandrel on which a service length of the strip is wound. in several turns for the tensioning of the strip, the rolling being carried out in several passes with maintenance of the winding, on each mandrel, of the length of service, the strip being laminated to the desired thickness on a useful part lying between the two lengths of service.
  • the length of upstream service is completely unrolled from the upstream uncoiler and is subjected to at least one rolling pass, the strip then being cut near the end of its useful part, so as to release, at its rear end in the direction of the last passes, a length at least equal to a necessary inspection length, at least a portion of which corresponds to the upstream service length which has been laminated at least once and thus gives an image of the appearance defects of the useful part.
  • the roll to be rolled is often laid first on a simple unwinder placed on one side of the rolling mill and from which the strip is unwound to pass into the rolling mill and attach to the winder / unwinder placed the other side.
  • the band goes to the side of the unroller. It is advantageous, at the end of the rolling of the upstream service length, that the rear end thereof is kept tight between the working rolls and that the direction of rotation of said rolls is reversed so as to return back a strip length sufficient to take an inspection length separated from the strip by the cutting thereof upstream of the cage, in the direction of the last pass, said length taken being placed on an inspection table and the band is returned in the direction of the last pass to completely wind on the downstream winder.
  • the inspection length is rolled twice, first in the direction of the last pass and then in the opposite direction, before being cut and sent to the inspection table which is placed on the opposite side to the unroller, compared to the rolling mill.
  • the downstream coil on which the strip is wound is placed on the same side of the rolling mill as the inspection table.
  • the strip can then be cut at a distance from its rear end corresponding to the desired inspection length, this inspection length being laminated once and sent directly to the inspection table placed on the same side of the rolling mill.
  • the invention thus makes it possible to take from the strip an inspection length of which at least the greater part corresponds to one of the two lengths of service which remains wound on the mandrels of each of the reels / unwinders, this length of service passing at least once between the rolls of the mill, which is sufficient to give an image of possible defects produced by said rolls on the useful length of the strip.
  • the inspection length is not taken on the useful part but on the tail of the strip which, in any case should have been discarded since it had not been laminated to the thickness required.
  • the invention applies to any reversible mill comprising at least one cage placed between two winder / unwinder devices, but it is particularly advantageous in the case of a reversible rolling mill with two rolling stands apart. one in the other because, in this case, the feathering is increased by the fact that the length of the tape included at the end of each pass, between the two cages has been rolled only once in the cage upstream and is therefore not at the required thickness.
  • the length to be discarded then comprises the remaining service length wound on the mandrel to which is added the distance between the two cages and the total length to be rejected is normally greater than the length of inspection required, which can, thus, be easily removed from the tail of the rolled strip at least once at the last pass.
  • the invention thus makes it possible to carry out an online inspection without taking an inspection length on the useful part of the strip and, consequently, to keep a high production yield.
  • the implementation of the method can be done at a reduced cost and on existing reversible rolling mills since cutting, routing and inspection means are used which, in any case, were necessary.
  • the invention also covers an improved rolling mill installation for implementing the method according to the invention.
  • the figure 1 represents a rolling mill with two reversible cages, wherein the rolling mill 1 comprises two rolling stands 3 and 5 spaced apart from each other and placed between two winder / unwinder devices, respectively 12 and 13.
  • the rolling mill 1 is therefore a rolling mill reversible for rolling a strip of sheet metal in both directions of scrolling ie from right to left in a first direction of travel and from left to right in the opposite direction.
  • the rolling mill 1 is, in addition, associated with a first-pass unroller 11 adapted to receive a coil 21.
  • This coil 21 is constituted by a sheet metal strip having an initial thickness that it is desired to reduce by rolling to obtain a sheet metal strip having a required final thickness.
  • the sheet metal strip is wound on itself to form the coil 21 and is first placed on the unroller 11 which has no mandrel.
  • Means 31 make it possible to grip the head of the sheet metal strip and to guide it to pass between the rolls of the two stands 3 and 5 while proceeding to the left, the head of the band being fixed on the reel / unwinder 12 placed on the second side of the mill 1 and which then serves as a winder for winding the sheet metal strip.
  • second rewinder second pass 13 is disposed between the first unwinding machine 11 and the input of the rolling mill 1.
  • the direction of rotation of the working rolls of the two stands 3 and 5 is then reversed to make scroll the band from left to right, in a second pass.
  • the upstream winder / unwinder 12 which operates uncoiler, is braked so as to tension the strip driven by the cylinders of the two stands 5 and 3.
  • the rolling can start at this second pass.
  • the rolling is then carried out alternately in the first direction of movement from the right to the left, for the odd passes, and in the second direction, from left to right, for the even passes, the number of passes depending on the conditions of the rolling and the final thickness required.
  • an upstream decontamination device 31 of the strip and upstream cutting shears 32 are located just upstream of the rolling mill 1, in the first direction of travel.
  • the upstream cage 3 comprises presses 33 making it possible to engage the leading end of the strip to be rolled between the roll trains of the upstream cage 3.
  • the stands 3 and 5 are of the quarto type, that is to say that they respectively comprise two working cylinders 30, 50 of small radius and two retaining cylinders 39, 59 of large radius.
  • the figure 1 has been simplified for the sake of clarity, but the rolling mill 1 also comprises all known means for rolling, such as means for cooling the rolls, measuring the tension of the strip, cooling the strip or maintain it, as well as deflecting rolls 45 for guiding the band.
  • means for rolling such as means for cooling the rolls, measuring the tension of the strip, cooling the strip or maintain it, as well as deflecting rolls 45 for guiding the band.
  • the downstream cage 5 is identical to the upstream cage 3, except that the decontamination device 51 and the engagement presses of the band 53 are arranged in downstream of the second cage 5, to allow the operation of the rolling mill in the opposite direction.
  • a switching device 60 guides the strip first to an overhead conveyor, then to an inspection conveyor constituting the inspection table 62. Possibly air conveyors and inspection are joined by an intermediate conveyor passage . When the sheet is on the inspection table 62, the actual inspection step is performed by a qualified person with the necessary means.
  • the rolling installation Downstream of the inspection table 62, the rolling installation comprises a tumbler type turning device 65 for returning the sample to inspect it on its other side.
  • the inspected sample is discarded in a bucket 69, if necessary after being cut into pieces by means of downstream shears 68.
  • the coils 11, 13 and 12 are carried by jacks allowing their loading and unloading.
  • the entire installation is based on concrete foundations.
  • a metal frame allows to maintain and support the various components of the installation.
  • FIG. 2a to 2j schematically shows the rolling plant of the figure 1
  • the reference figures have been included to indicate the same constituent elements.
  • the upstream 3 and downstream 5 cages (in the first direction of travel) are of the quarto type comprising two working cylinders and two support cylinders but could be of any other type.
  • the first winder passes 12 and the second winder 13 passes are schematized with their mandrel unlike the unroller first pass 11 which does not.
  • the coils 21, 22 and 23 are shown at different stages of the inspection process according to the invention.
  • a roll of sheet metal 21 is disposed on the unrolling first pass 11 and unwound.
  • the leading end 101 corresponding to the front end of the sheet metal strip 100 is engaged between the working rolls of the upstream stand 3. Once the band 100 is engaged, the working rolls of the upstream stand 3 are used to to apply a friction force for driving the band 100.
  • the leading end 101 then moves in a first direction of travel towards the downstream cage 5 as indicated by the arrow, that is to say say from right to left.
  • the leading end 101 after engagement between the rolls of the second stand 5, has been conventionally fixed to the mandrel of the first pass winder 12.
  • the work rolls of stands 3 and 5 are clamped on the band and driven in rotation to control the unwinding of the sheet metal strip 100 which, at the same time, is wound around the mandrel of the first pass winder 12 ( Figure 2c ).
  • the coil 21 is unwound while the coil 22 is wound.
  • the first unrolling pass 11 having no mandrel, it is impossible to apply a tension on the band 100 during the first pass. Consequently, the desired reduction rate can not be achieved during this first scrolling pass.
  • the figure 2d schematically represents the end of the first pass.
  • the reel 21 is completely unwound and the sheet metal strip 100 is wound around the mandrel of the first rewinder 12 forming a reel 22.
  • the first pass ends when the tail end 102 of the web 100 is near the upstream cage 3. It is advantageous not to disengage the tail end 102 at the end of the first pass. By disengagement, it is meant that the tail end 102 goes beyond the downstream cage 5.
  • the first pass is stopped at least when the tail end 102 is between the cages. Of preferably, the first pass is stopped when the tail end 102 is still upstream of the upstream cage 3.
  • the operating direction of the mill 1 is then reversed so as to control the running of the sheet metal strip 100 in the opposite direction indicated by the arrow shown on ia figure 2e .
  • the working rolls of cages 3 and 5 are simply tightened to control the movement of web 100 from left to right until its front end 102 can be fixed to the mandrel of the machine.
  • second pass winder 13 is simply tightened to control the movement of web 100 from left to right until its front end 102 can be fixed to the mandrel of the machine.
  • the number N of passes of the rolling cycle depends on the reduction rate to be achieved in order to obtain the desired final thickness.
  • the inspection will be carried out on a section taken on one of these two lengths of service which should, in any case, be rejected. It must, however, that this section is an image of the useful part to present the same aspect and, in particular, the same marks and imprints of the cylinders.
  • the remaining portion 105 of the strip which has remained tight between the rolls of cages 3 and 5, is driven to the left, that is to say in the first direction of movement and directed by a switch to the inspection table 62 shown on the figure 1 .
  • This section 105 corresponding, at least for the most part, to the length of service, is passed twice between the working cylinders, respectively in the first direction of movement from left to right, on the figure 2g and in the second direction of scrolling, from the right to the left, on the Figures 2h, 2i .
  • the band has remained energized, in one direction or the other, between the two stands 5 and 3.
  • This part 105 therefore undergoes, when its passage between the cylinders, the same marks as the useful part of the band, these marks reproducing identically to each pass.
  • the sampled section 105 therefore has the same appearance as the strip, which makes it possible to check the quality of the latter.
  • the sample 105 is positioned on the inspection table where the actual inspection takes place, possibly on both sides by turning the sample 105. Meanwhile, the coil 23 is removed from the rolling installation and brought to, for example, another installation for further processing. Similarly, during the inspection of the sample 105, a new coil 21 'consisting of a new strip of sheet metal 100' to be rolled is loaded onto the first pass unroller 11 and its leading end 101 'is engaged in the rolling mill 1 so as to prepare the next rolling cycle.
  • the inspection method according to the invention therefore takes advantage of the fact that the non-rolled service length, which must be rejected in any case, is used as an inspection sample because it comprises the marks and impressions of the rolls. Indeed, although not rolled to the right thickness, the unlaminated length passes between the cylinders which leave their marks on both sides.
  • the length of inspection shall be chosen to include at least one period of each of the rolling mill roll marks: Thus, the length of inspection shall include at least the unlaminated length, but may also be greater if the period of one of the roll trains requires it.
  • the invention thus makes it possible to inspect the quality of rolling on-line by minimizing the losses of rolled material to the desired thickness, since the inspection is carried out on a part of the sheet that should have been discarded, whatever happens. not being the right thickness.
  • the inspection operation does not consume time. Indeed, as shown in figure 2j when the inspection of the rolling of a first cycle takes place, the following rolling cycle can be prepared by engaging for example the leading end 101 'of the next coil 21'. The handling of the coil 23 produced is also done synchronously with the inspection step.
  • the implementation of the inspection method as described above does not require or few modifications of existing facilities.
  • shears may be located upstream or downstream of the rolling mill, possibly between the stands of the rolling mill.
  • shears are disposed only downstream of the mill 1
  • the mill can no longer serve as a means of driving the sheet. sample to the inspection table. It would then be necessary to have own drive means capable of moving the sample on the inspection table.
  • the inspection table may be located downstream of the rolling mill 1 in the first direction of travel, and will inspect a sample corresponding to the length of service wound on the reel / unwinder 13 and, being in line in the first direction of travel.
  • the inspection table can be placed on the same side as the winder 12 on which the band is wound. If there is a shear between the second cage 5 and the winder 12, the latter can cut the strip at a distance from its rear end 102 at least equal to the required inspection length. The strip can then be wound completely on the reel 12 and its rear part, which constitutes the inspection length, remains tight between the rolls of the stands 5 and 3 which drive it to the left, in the first direction of travel so that to direct him to the inspection table. In this case, the inspection section only passes once between the rolls of the two stands 5 and 3, but this passage is sufficient for the rolls to print and the inspection length has a representative appearance of that of the useful part of the band.
  • the method according to the invention is, however, applicable to a rolling mill comprising a single reversible cage.
  • the rear portion of the strip is no longer energized but the passage between the working rolls which remain tight on the strip, allows to print the same marks on the two faces thereof, the inspection length taken from the rear end of the strip and constituting the length of service, having the same appearance as the useful part of the strip.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Winding, Rewinding, Material Storage Devices (AREA)

Abstract

The invention concerns a method for inspecting a strip in a reversible rolling device (1, 3, 5) comprising a cage arranged between two winding/unwinding devices (12, 13) having each a mandrel. The rolling is performed in several passes until the desired thickness is obtained over the entire length of a useful part included between two service lengths maintained wound on each of the mandrels. The invention is characterized in that at the end of the last pass between a winder/unwinder placed upstream of the cage (3, 5) in the rolling direction and acting as unwinding device, and a downstream winder/unwinder acting as winding device, the upstream service length is completely unwound from the unwinding device, then subjected to a rolling pass; the strip is then cut in the vicinity of its useful part to release, at its rear end in the direction of the last pass, a length of inspection part of which corresponds to the upstream service length rolled once.

Description

L'invention est relative aux laminoirs. Plus particulièrement, l'invention a pour objet un procédé et une installation d'inspection de la qualité d'une bande de tôle après laminage.The invention relates to rolling mills. More particularly, the subject of the invention is a method and an installation for inspecting the quality of a sheet metal strip after rolling.

On sait que, à l'issue du laminage, la bande de tôle laminée peut présenter certains défauts d'aspect qui peuvent être dus, par exemple, à une légère variation d'épaisseur dans le sens transversal, provenant de la déformation et de l'usure des cylindres et/ou du cédage de la cage, ou bien de marques laissées par les cylindres de travail, certains défauts pouvant aussi être dûs aux cylindres de soutien ou à la cage elle-même.It is known that, at the end of the rolling, the laminated sheet metal strip may have certain appearance defects which may be due, for example, to a slight variation in thickness in the transverse direction, resulting from the deformation and the wear of the rolls and / or the cedar cage, or marks left by the working rolls, some defects may also be due to the support rolls or the cage itself.

Ces défauts d'aspect se reproduisent sur chaque face, dans la direction longitudinale de laminage, avec une période correspondant au développement, dans cette direction, de la circonférence des cylindres de travail.These defects of appearance are reproduced on each face, in the longitudinal direction of rolling, with a period corresponding to the development, in this direction, of the circumference of the working rolls.

Or, il est de plus en plus nécessaire de livrer des tôles ayant une qualité de surface et, d'une façon générale, un aspect aussi parfaits que possible. Pour cela, il faut donc vérifier l'état de surface de la bande de tôle à l'issue du laminage, en particulier, pour observer les marques laissées périodiquement sur la bande par le passage entre les cylindres de travail.However, it is increasingly necessary to deliver sheets having a surface quality and, in general, an aspect as perfect as possible. For this, it is necessary to check the surface condition of the sheet metal strip after the rolling, in particular, to observe the marks left periodically on the strip by the passage between the working rolls.

De façon connue, on peut, par exemple prélever une section de la bande de tôle sortant du laminoir, afin d'en inspecter les deux faces. L'inspection se fait sur une longueur de bande, dite longueur d'inspection permettant d'observer les marques ou empreintes laissées par les cylindres du laminoir et la longueur d'inspection correspond donc à la plus grande des périodes des marques des différents cylindres. Dans un laminoir tandem à plusieurs cages, la longueur d'inspection correspond à la période des marques produites dans la cage la plus en amont, à partir de laquelle la bande subit le plus grand allongement en passant dans les cages suivantes.In a known manner, it is possible, for example, to take a section of the strip of sheet metal coming out of the rolling mill, in order to inspect both faces. The inspection is carried out on a strip length, the so-called inspection length making it possible to observe the marks or impressions left by the rolls of the rolling mill, and the length of inspection therefore corresponds to the largest period of the marks of the different rolls. In a multi-cage tandem mill, the length of inspection corresponds to the period of the marks produced in the cage furthest upstream, from which band undergoes the greatest elongation by passing into the following cages.

De façon connue, l'inspection peut se faire dans une installation particulière où sont apportées certaines bobines à inspecter, après leur production par l'installation de laminage. L'installation d'inspection comporte une dérouleuse dite d'inspection et une table horizontale permettant de dérouler une longueur de produit correspondant à la longueur d'inspection, sur laquelle l'opérateur peut réaliser l'observation, le repérage, le calepinage ou toute autre opération de prise en compte des marques présentes sur les deux faces de l'échantillon servant à l'inspection.In known manner, the inspection can be done in a particular installation where are made some reels to inspect, after their production by the rolling mill. The inspection facility includes an inspection and a horizontal table for unrolling a length of product corresponding to the length of inspection, on which the operator can perform the observation, the tracking, the layout or any another operation to take into account the marks on both sides of the sample used for the inspection.

Une telle installation d'inspection est coûteuse à réaliser et, aussi, à exploiter. En effet, il faut retirer une bobine du lot produit, la convoyer vers l'installation d'inspection, puis l'inspecter avant de poursuivre son acheminement. Cependant, l'installation de laminage continue à produire pendant l'inspection d'un échantillon de bande laminée, et la détection d'un défaut important conduit donc à rebuter ensuite les bandes de tôle laminées produites dans l'intervalle.Such an inspection facility is expensive to produce and also to operate. Indeed, it is necessary to remove a reel from the produced batch, to convey it towards the inspection facility, then to inspect it before continuing its routing. However, the rolling mill continues to produce during the inspection of a rolled strip sample, and the detection of a large defect then results in the rolled sheet strips produced in the gap being subsequently discarded.

Il est possible d'éviter cet inconvénient dans les installations de laminage en continu comportant plusieurs cages successives fonctionnant en tandem, la bande laminée étant enroulée en bobine après la sortie de la dernière cage. Dans ce cas, en effet, l'installation d'enroulement comporte habituellement au moins deux mandrins fonctionnant alternativement, par exemple sur une bobineuse de type carrousel, et la bande est coupée au vol, à la fin de l'enroulement sur un mandrin, pour continuer l'enroulement sur un autre mandrin. On peut alors réaliser deux coupes successives qui sont espacées de manière à prélever une longueur d'inspection, celle-ci étant ensuite acheminée vers une table d'inspection grâce à des systèmes d'aiguillage et d'entraînement. Cette longueur d'inspection a subi toutes les étapes de laminage, comme le reste de la bande et son état de surface est donc bien représentatif de celui de la bande.It is possible to avoid this disadvantage in continuous rolling installations comprising several successive cages operating in tandem, the rolled strip being wound into a reel after the exit of the last stand. In this case, in fact, the winding installation usually comprises at least two cores operating alternately, for example on a carousel-type winder, and the band is cut in flight, at the end of the winding on a mandrel, to continue winding on another mandrel. Two successive cuts can then be made which are spaced so as to take an inspection length, which is then conveyed to an inspection table by means of switching and drive systems. This length of inspection has undergone all rolling stages, as the rest of the band and its surface condition is therefore well representative of that of the band.

Un tel procédé n'est, cependant, pas applicable à une installation de laminage réversible comportant au moins une cage de laminage disposée entre deux dispositifs enrouleur/dérouleur entre lesquels la bande circule alternativement dans un sens et dans l'autre chaque dispositif enrouleur/dérouleur servant, selon le sens de laminage, de bobineuse en aval de la cage de laminage et de débobineuse en amont.Such a method is, however, not applicable to a reversible rolling mill comprising at least one rolling stand disposed between two winder / unwinder devices between which the band alternately circulates in one direction and the other each winder device / unwinder serving, according to the direction of rolling, the winder downstream of the upstream rolling and uncoiling shaft.

En effet, le laminage n'étant pas continu, il n'est pas utile de disposer d'une bobineuse carrousel, avec coupe au vol de la bande.Indeed, the rolling is not continuous, it is not useful to have a carousel winder, with cutting theft of the tape.

De plus, selon le nombre de passes, la bobineuse aval, à la fin de la dernière passe, peut être placée d'un côté ou de l'autre du laminoir.In addition, depending on the number of passes, the downstream winder, at the end of the last pass, can be placed on one side or the other of the rolling mill.

Dans ce cas, habituellement, la longueur d'inspection est simplement prélevée sur la bande à la fin de la dernière passe, d'un côté ou de l'autre du laminoir.In this case, usually, the length of inspection is simply taken on the band at the end of the last pass, on one side or the other of the rolling mill.

Bien entendu, cette longueur d'inspection doit être, ensuite, rebutée. Or, dans le laminage réversible, il est déjà nécessaire de rebuter une longueur non négligeable de la bande.Of course, this inspection length must then be rejected. However, in reversible rolling, it is already necessary to discard a non-negligible length of the strip.

En effet, pour permettre une mise en traction de la bande, pendant le laminage, dans un sens ou dans l'autre, il est nécessaire: qu'une certaine longueur de bande que l'on peut appeler « longueur de service » soit enroulée en plusieurs spires sur chaque mandrin.Indeed, to allow a traction of the band, during rolling, in one direction or the other, it is necessary: that a certain length of tape that can be called "length of service" is wound in several turns on each mandrel.

Dans certains cas, cette longueur de service servant à la mise en tension de la bande, est constituée d'une rallonge soudée à chaque extrémité de la bande. Celle-ci peut alors être laminée pratiquement sur toute sa longueur mais la soudure des deux rallonges puis leur retrait demande un certain temps et diminue la productivité de l'installation. Lorsque la bobine est de grande longueur, il semble donc préférable de sacrifier, à chaque extrémité de la bande, une longueur de service qui n'est pas laminée à l'épaisseur souhaitée et doit donc être rebutée.In some cases, this length of service used to tension the strip, consists of an extension welded to each end of the strip. This can then be rolled practically over its entire length, but the welding of the two extensions and their removal takes a certain time and decreases the productivity of the installation. When the coil is of great length, it seems It is preferable to sacrifice at each end of the strip a service length which is not rolled to the desired thickness and must therefore be discarded.

Habituellement, une telle installation de laminage réversible comporte, en plus des deux dispositifs enrouleur/dérouleur, une dérouleuse dite « première passe » capable de reprendre des bobines enroulées sur elles-mêmes et sans traction. Une bobine étant posée sur la dérouleuse première passe, le produit est déroulé à partir de ceile-ci, dans un premier sens de défilement, en faisant passer sa tête dans la cage pour l'engager sur le dispositif enrouleur/dérouleur placé de l'autre côté de la cage et servant donc, de bobineuse. Le produit est alors enroulé presque complètement sur cette bobineuse jusqu'à ce que son extrémité, formant la queue de la bande, quitte la dérouleuse, cette première passe s'effectuant, donc, sans laminage.Usually, such a reversible rolling plant comprises, in addition to the two devices winder / unwinder, a so-called "first pass" unwinder capable of taking coils wound on themselves and without traction. A coil being placed on the first pass unroller, the product is unrolled from it in a first direction of travel, by passing his head in the cage to engage on the device winder / unwinder placed of the other side of the cage and thus serving, of coiler. The product is then wound almost completely on this winder until its end, forming the tail of the strip, leaves the unroller, this first pass being made, therefore, without rolling.

On fait alors marche arrière pour engager la queue de la bande sur le second dispositif enrouleur/dérouleur placé du même côté que la dérouleuse première passe et sur lequel ladite extrémité est fixée puis enroulée en spires superposées. Cependant, l'enrouleur/dérouleur placé en amont du laminoir, est freiné de façon de la bande, entraînée par la rotation des cylindres, soit mise sous tension, ce qui permet de commencer le laminage qui est, donc, effectué dans le sens inverse du premier sens de défilement au cours de cette deuxième passe.It is then back to engage the tail of the band on the second winder / unwinder device placed on the same side as the first pass rewinder and on which said end is fixed and then wound in superimposed turns. However, the winder / unwinder placed upstream of the mill, is braked so the band, driven by the rotation of the rolls, is energized, which allows to start the rolling which is, therefore, carried out in the opposite direction the first direction of scrolling during this second pass.

Le défilement de la bande est, cependant arrêté avant la fin du déroulement de façon à laisser, sur le mandrin de la débobineuse, en amont de la cage, une longueur minimale enroulée correspondant au nombre de spires nécessaires au maintien en tension de la bande et que l'on appellera « longueur de service ».The running of the strip is, however, stopped before the end of the unwinding so as to leave, on the mandrel of the uncoiler, upstream of the cage, a minimum wound length corresponding to the number of turns required to maintain tension in the strip and which will be called "service length".

Le laminage peut alors être effectué alternativement dans un sens et dans l'autre entre les deux enrouleurs/dérouleurs qui servent, alternativement, de bobineuse et de débobineuse, mais, pour maintenir à chaque passe la tension nécessaire au laminage, il est nécessaire de conserver sur chaque mandrin une longueur de service qui n'est donc pas laminée. A la fin de la dernière passe, il faut donc éliminer la longueur de service se trouvant à la queue de la bande et qui ne présenter pas les qualités requises. De même, la longueur de service se trouvant à la tête de la bande et enroulée à l'intérieur de la bobine, devra être éliminée à la fin du déroulement de celle-ci.The rolling can then be performed alternately in one direction and the other between the two winders / unwinders that serve, alternately, winder and uncoiler, but, to maintain each pass the tension necessary for rolling, it is necessary to keep on each mandrel a length of service that is not laminated. At the end of the last pass, it is necessary to eliminate the length of service at the tail of the tape and which do not have the required qualities. Similarly, the service length at the head of the strip and wound inside the coil, should be eliminated at the end of the course of the latter.

Une bobine laminée n'est donc laminée à l'épaisseur souhaitée que sur une partie utile centrale encadrée par deux longueurs de service non laminées, qui représentent une perte appelée « mise au mille ». Comme indiqué plus haut, il faut ajouter habituellement, à cette perte, la longueur d'inspection qui, est prélevée sur la partie utile de la bande présentant les qualités requises. Un tel procédé d'inspection augmente donc la mise au mille.A rolled coil is therefore laminated to the desired thickness only on a central useful portion framed by two non-rolled service lengths, which represent a loss called "put to the mile". As indicated above, this inspection loss usually has to be added to the length of inspection which is taken from the useful part of the strip having the required qualities. Such an inspection process therefore increases the feathering.

L'invention a pour objet, dans un laminoir réversible, de remédier à ces inconvénients grâce à un nouveau procédé permettant une inspection en ligne en conservant un rendement de production élevé, la longueur rebutée ne dépassant pas les deux longueurs de service qui doivent rester enroulées sur chaque mandrin et ne présentent donc pas l'épaisseur requise.The object of the invention is to overcome these drawbacks in a reversible rolling mill by means of a new method allowing an on-line inspection while maintaining a high production yield, the rejected length not exceeding the two lengths of service which must remain wound. on each mandrel and therefore do not have the required thickness.

L'invention couvre également une installation de laminage pour la mise en oeuvre du procédé.The invention also covers a rolling plant for carrying out the method.

L'invention s'applique donc, d'une façon générale, à une installation de laminage réversible, comportant au moins une cage de laminage disposée entre deux dispositifs enrouleurs/dérouleurs ayant chacun un mandrin sur lequel une longueur de service de la bande est enroulée en plusieurs spires pour la mise en tension de la bande, le laminage étant réalisé en plusieurs passes avec maintien de l'enroulement, sur chaque mandrin, de la longueur de service, la bande étant laminée à l'épaisseur souhaitée sur une partie utile comprise entre les deux longueurs de service.The invention therefore applies, in a general manner, to a reversible rolling installation, comprising at least one rolling stand disposed between two reel / unwinder devices each having a mandrel on which a service length of the strip is wound. in several turns for the tensioning of the strip, the rolling being carried out in several passes with maintenance of the winding, on each mandrel, of the length of service, the strip being laminated to the desired thickness on a useful part lying between the two lengths of service.

Conformément à l'invention, à la fin de la dernière passe de laminage entre un enrouleur/dérouleur placé en amont de la cage, dans le sens de laminage et servant de débobineuse, et un enrouleur/dérouleur aval servant de bobineuse, la longeur de service amont est complètement déroulée de la débobineuse amont et est soumise à au moins une passe de laminage, la bande étant ensuite coupée au voisinage de la fin de sa partie utile, de façon à libérer, à son extrémité arrière dans le sens de la dernière passe, une longueur au moins égale à une longueur d'inspection nécessaire, dont au moins une partie correspond à la longueur de service amont qui a été laminée au moins une fois et donne ainsi une image des défauts d'aspect de la partie utile.According to the invention, at the end of the last rolling pass between a winder / unwinder positioned upstream of the cage, in the rolling direction and serving as a uncoiler, and a downstream winder / unwinder serving as winder, the length of upstream service is completely unrolled from the upstream uncoiler and is subjected to at least one rolling pass, the strip then being cut near the end of its useful part, so as to release, at its rear end in the direction of the last passes, a length at least equal to a necessary inspection length, at least a portion of which corresponds to the upstream service length which has been laminated at least once and thus gives an image of the appearance defects of the useful part.

Comme indiqué plus haut, la bobine à laminer est souvent posée d'abord sur une simple dérouleuse placée sur un côté du laminoir et à partir de laquelle la bande est déroulée pour passer dans le laminoir et se fixer sur l'enrouleur/dérouleur placé de l'autre côté.As indicated above, the roll to be rolled is often laid first on a simple unwinder placed on one side of the rolling mill and from which the strip is unwound to pass into the rolling mill and attach to the winder / unwinder placed the other side.

Dans le cas où la dernière passe réversible est une passe paire, la bande se dirige du côté de la dérouleuse. Il est avantageux, à la fin du laminage de la longueur de service amont, que l'extrémité arrière de celle-ci soit maintenue serrée entre les cylindres de travail et que le sens de rotation desdits cylindres soit inversé de façon à renvoyer en arrière une longueur de bande suffisante pour y prélever une longueur d'inspection séparée de la bande par la coupe de celle-ci en amont de la cage, dans le sens de la dernière passe, ladite longueur prélevée étant placée sur une table d'inspection et la bande étant renvoyée dans le sens de la dernière passe pour s'enrouler complètement sur la bobineuse aval.In the case where the last reversible pass is an even pass, the band goes to the side of the unroller. It is advantageous, at the end of the rolling of the upstream service length, that the rear end thereof is kept tight between the working rolls and that the direction of rotation of said rolls is reversed so as to return back a strip length sufficient to take an inspection length separated from the strip by the cutting thereof upstream of the cage, in the direction of the last pass, said length taken being placed on an inspection table and the band is returned in the direction of the last pass to completely wind on the downstream winder.

Dans ce cas, la longueur d'inspection est laminée deux fois, d'abord dans le sens de la dernière passe puis dans le sens inverse, avant d'être coupée et envoyée vers la table d'inspection qui est placée du côté opposé à la dérouleuse, par rapport au laminoir.In this case, the inspection length is rolled twice, first in the direction of the last pass and then in the opposite direction, before being cut and sent to the inspection table which is placed on the opposite side to the unroller, compared to the rolling mill.

En revanche, dans ie cas où ia dernière passe réversible est une passe impaire, la bobine aval sur laquelle s'enroule la bande est placée du même côté du laminoir que la table d'inspection. La bande peut alors être coupée à une distance de son extrémité arrière correspondant à la longueur d'inspection souhaitée, cette longueur d'inspection étant laminée une seule fois et envoyée directement vers la table d'inspection placée du même côté du laminoir.On the other hand, in the case where the last reversible pass is an odd pass, the downstream coil on which the strip is wound is placed on the same side of the rolling mill as the inspection table. The strip can then be cut at a distance from its rear end corresponding to the desired inspection length, this inspection length being laminated once and sent directly to the inspection table placed on the same side of the rolling mill.

L'invention permet ainsi de prélever sur la bande une longueur d'inspection dont au moins la plus grande partie correspond à une des deux longueurs de service qui reste enroulées sur les mandrins de chacun des enrouleurs/dérouleurs, cette longueur de service passant au moins une fois entre les cylindres du laminoir, ce qui est suffisant pour donner une image de défauts éventuels produits par lesdits cylindres sur la longueur utile de la bande.The invention thus makes it possible to take from the strip an inspection length of which at least the greater part corresponds to one of the two lengths of service which remains wound on the mandrels of each of the reels / unwinders, this length of service passing at least once between the rolls of the mill, which is sufficient to give an image of possible defects produced by said rolls on the useful length of the strip.

Grâce à l'invention, la longueur d'inspection n'est donc pas prélevée sur la partie utile mais sur la queue de la bande qui, de toute façon aurait dû être rebutée puisqu'elle n'avait pas été laminée à l'épaisseur requise.Thanks to the invention, the inspection length is not taken on the useful part but on the tail of the strip which, in any case should have been discarded since it had not been laminated to the thickness required.

D'une façon générale, l'invention s'applique à tout laminoir réversible comportant au moins une cage placée entre deux dispositifs enrouleurs/dérouleurs, mais elle est particulièrement avantageuse dans le cas d'un laminoir réversible à deux cages de laminage écartées l'une de l'autre car, dans ce cas, la mise au mille est augmentée par le fait que la longueur de bande comprise à la fin de chaque passe, entre les deux cages n'a été laminée qu'une seule fois dans la cage amont et n'est donc pas à l'épaisseur requise. La longueur à rebuter comprend alors la longueur de service restant enroulée sur le mandrin à laquelle s'ajoute la distance entre les deux cages et la longueur totale à rebuter est donc, normalement, supérieure à la longueur d'inspection nécessaire, celle-ci pouvant, ainsi, être facilement prélevée sur la queue de la bande laminée au moins une fois à la dernière passe.In general, the invention applies to any reversible mill comprising at least one cage placed between two winder / unwinder devices, but it is particularly advantageous in the case of a reversible rolling mill with two rolling stands apart. one in the other because, in this case, the feathering is increased by the fact that the length of the tape included at the end of each pass, between the two cages has been rolled only once in the cage upstream and is therefore not at the required thickness. The length to be discarded then comprises the remaining service length wound on the mandrel to which is added the distance between the two cages and the total length to be rejected is normally greater than the length of inspection required, which can, thus, be easily removed from the tail of the rolled strip at least once at the last pass.

L'invention permet donc de réaliser une inspection en ligne sans prélever une longueur d'inspection sur la partie utile de la bande et, par conséquent de conserver un rendement de production élevée.The invention thus makes it possible to carry out an online inspection without taking an inspection length on the useful part of the strip and, consequently, to keep a high production yield.

Par ailleurs, la mise en oeuvre du procédé peut se faire à un coût réduit et sur des installations existantes de laminage réversible puisque l'on utilise des moyens de coupe, d'aiguillage et d'inspection qui, de toute façon, étaient nécessaires.Furthermore, the implementation of the method can be done at a reduced cost and on existing reversible rolling mills since cutting, routing and inspection means are used which, in any case, were necessary.

L'invention couvre également une installation de laminoir perfectionnée pour la mise en oeuvre du procédé selon l'invention.The invention also covers an improved rolling mill installation for implementing the method according to the invention.

Mais d'autres caractéristiques et avantages de l'invention apparaîtront dans la description qui va suivre d'un mode de réalisation particulier de l'invention, donnés uniquement à titre illustratif et non limitatif, en référence aux dessins annexés sur lesquels :

  • la figure 1 est une représentation schématique d'une installation de laminage réversible selon l'invention pour la mise en oeuvre du procédé d'inspection selon l'invention ;
  • les figures 2a à 2j sont des vues schématiques du laminoir de la figure 1 dans différentes étapes du procédé selon l'invention.
But other features and advantages of the invention will appear in the following description of a particular embodiment of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings in which:
  • the figure 1 is a schematic representation of a reversible rolling plant according to the invention for carrying out the inspection method according to the invention;
  • the Figures 2a to 2j are schematic views of the rolling mill of the figure 1 in different stages of the process according to the invention.

La figure 1 représente une installation de laminage à deux cages réversibles, dans laquelle le laminoir 1 comporte deux cages de laminage 3 et 5 écartées l'une de l'autre et placées entre deux dispositifs enrouleurs/dérouleurs, respectivement 12 et 13. Le laminoir 1 est donc un laminoir réversible permettant de laminer une bande de tôle dans les deux sens de défilement à savoir de droite à gauche dans un premier sens de défilement et de gauche à droite dans le sens inverse.The figure 1 represents a rolling mill with two reversible cages, wherein the rolling mill 1 comprises two rolling stands 3 and 5 spaced apart from each other and placed between two winder / unwinder devices, respectively 12 and 13. The rolling mill 1 is therefore a rolling mill reversible for rolling a strip of sheet metal in both directions of scrolling ie from right to left in a first direction of travel and from left to right in the opposite direction.

Dans le mode de réalisation représenté sur les figures, le laminoir 1 est, en outre, associé à une dérouleuse première passe 11 apte à recevoir une bobine 21.In the embodiment shown in the figures, the rolling mill 1 is, in addition, associated with a first-pass unroller 11 adapted to receive a coil 21.

Cette bobine 21 est constituée par une bande de tôle ayant une épaisseur initiale que l'on souhaite réduire par laminage pour obtenir une bande de tôle ayant une épaisseur finale requise. La bande de tôle est enroulée sur elle-même pour former la bobine 21 et est d'abord placée sur la dérouleuse 11 qui ne comporte pas de mandrin. Des moyens 31 permettent de saisir la tête de la bande de tôle et de la guider pour passer entre les cylindres des deux cages 3 et 5 en se déroulant vers la gauche, la tête de la bande étant fixée sur l'enrouleur/dérouleur 12 placé sur le second côté du laminoir 1 et qui sert alors de bobineuse pour bobiner la bande de tôle. Celle-ci défile donc de la droite vers la gauche dans cette première passe de défilement qui s'effectue sans laminage jusqu'à déroulement complet de la bande dont l'extrémité arrière, formant la queue, reste serrée entre les cylindres de travail des deux cages 3 et 5, de la façon représentée schématiquement sur la figure 2d.This coil 21 is constituted by a sheet metal strip having an initial thickness that it is desired to reduce by rolling to obtain a sheet metal strip having a required final thickness. The sheet metal strip is wound on itself to form the coil 21 and is first placed on the unroller 11 which has no mandrel. Means 31 make it possible to grip the head of the sheet metal strip and to guide it to pass between the rolls of the two stands 3 and 5 while proceeding to the left, the head of the band being fixed on the reel / unwinder 12 placed on the second side of the mill 1 and which then serves as a winder for winding the sheet metal strip. This scrolls from the right to the left in this first scrolling pass that occurs without rolling until complete unwinding of the band whose rear end, forming the tail, remains tight between the working rolls of the two cages 3 and 5, as shown diagrammatically on the figure 2d .

Comme habituellement, un deuxième enrouleur/dérouleur amont encore appelé bobineuse deuxième passe 13 est disposé entre la dérouleuse première passe 11 et l'entrée du laminoir 1. Le sens de rotation des cylindres de travail des deux cages 3 et 5 est alors inversé pour faire défiler la bande de la gauche vers la droite, dans une seconde passe.As usual, a second reel / unwinder upstream called second rewinder second pass 13 is disposed between the first unwinding machine 11 and the input of the rolling mill 1. The direction of rotation of the working rolls of the two stands 3 and 5 is then reversed to make scroll the band from left to right, in a second pass.

L'extrémité droite de la bande, devenue la tête de celle-ci, est engagée sur le mandrin de l'enrouleur/dérouleur 13 qui fonctionne alors en bobineuse deuxième passe (figure 2e).The right end of the band, which became the head thereof, is engaged on the mandrel of the winder / unwinder 13, which then operates in a second pass winder ( figure 2e ).

L'enrouleur/dérouleur amont 12 qui fonctionne en débobineuse, est freiné de façon à mettre sous tension la bande entraînée par les cylindres des deux cages 5 et 3. Le laminage peut donc commencer à cette seconde passe.The upstream winder / unwinder 12 which operates uncoiler, is braked so as to tension the strip driven by the cylinders of the two stands 5 and 3. The rolling can start at this second pass.

Le laminage est ensuite effectué alternativement dans le premier sens de défilement de la droite vers ia gauche, pour les passes impaires, et dans le second sens, de la gauche vers la droite, pour les passes paires, le nombre de passes dépendant des conditions de laminage et de l'épaisseur finale requise.The rolling is then carried out alternately in the first direction of movement from the right to the left, for the odd passes, and in the second direction, from left to right, for the even passes, the number of passes depending on the conditions of the rolling and the final thickness required.

Cependant, pour permettre la mise en tension de la bande, une longueur de service reste enroulée sur l'enrouleur/dérouleur 13 servant de débobineuse pour les passes impaires ainsi que sur l'enrouleur/dérouleur 12 servant de débobineuse pour les passes paires.However, to allow the tensioning of the band, a length of service remains wound on the reel / unwinder 13 serving uncoiler for odd passes and the reel / unwinder 12 serving uncoiler for even passes.

De façon connue, un dispositif de décintrage amont 31 de la bande ainsi que des cisailles amont 32 de coupe sont situés juste en amont du laminoir 1, dans le premier sens de défilement.In a known manner, an upstream decontamination device 31 of the strip and upstream cutting shears 32 are located just upstream of the rolling mill 1, in the first direction of travel.

De même, la cage amont 3 comporte des presses 33 permettant d'engager l'extrémité de tête de la bande à laminer entre les trains de cylindres de la cage amont 3.Similarly, the upstream cage 3 comprises presses 33 making it possible to engage the leading end of the strip to be rolled between the roll trains of the upstream cage 3.

De préférence, les cages 3 et 5 sont du type quarto, c'est-à-dire qu'elles comportent respectivement deux cylindres de travail 30, 50 de petit rayon et deux cylindres de maintien 39, 59 de grand rayon.Preferably, the stands 3 and 5 are of the quarto type, that is to say that they respectively comprise two working cylinders 30, 50 of small radius and two retaining cylinders 39, 59 of large radius.

La figure 1 a été simplifiée pour des raisons de clarté, mais le laminoir 1 comporte également tous moyens connus pour le laminage, comme des moyens pour refroidir les cylindres, mesurer la tension de la bande, refroidir la bande ou la maintenir, ainsi que des cylindres déflecteurs 45 pour le guidage de la bande.The figure 1 has been simplified for the sake of clarity, but the rolling mill 1 also comprises all known means for rolling, such as means for cooling the rolls, measuring the tension of the strip, cooling the strip or maintain it, as well as deflecting rolls 45 for guiding the band.

La cage aval 5 est identique à la cage amont 3, à l'exception du fait que le dispositif de décintrage 51 ainsi que les presses d'engagement de la bande 53 sont disposés en aval de la deuxième cage 5, afin de permettre le fonctionnement du laminoir dans le sens inverse.The downstream cage 5 is identical to the upstream cage 3, except that the decontamination device 51 and the engagement presses of the band 53 are arranged in downstream of the second cage 5, to allow the operation of the rolling mill in the opposite direction.

Un dispositifs d'aiguillage 60 permet de guider la bande d'abord vers un convoyeur aérien, puis vers un convoyeur d'inspection constituant la table d'inspection 62. Eventuellement des convoyeurs aériens et d'inspection sont réunis par un convoyeur intermédiaire de passage. Lorsque la tôle est sur la table d'inspection 62, l'étape d'inspection proprement dite est réalisée par une personne qualifiée disposant des moyens nécessaires.A switching device 60 guides the strip first to an overhead conveyor, then to an inspection conveyor constituting the inspection table 62. Possibly air conveyors and inspection are joined by an intermediate conveyor passage . When the sheet is on the inspection table 62, the actual inspection step is performed by a qualified person with the necessary means.

En aval de la table d'inspection 62, l'installation de laminage comporte un dispositif de retournement 65 du type à tambour permettant de retourner l'échantillon pour l'inspecter sur son autre face.Downstream of the inspection table 62, the rolling installation comprises a tumbler type turning device 65 for returning the sample to inspect it on its other side.

A l'issue de l'étape d'inspection, comme cela sera décrit ci-dessous en référence aux figures 2, l'échantillon inspecté est rebuté dans une benne 69, le cas échéant après avoir été découpé en morceaux au moyen de cisailles aval 68.At the end of the inspection step, as will be described below with reference to figures 2 the inspected sample is discarded in a bucket 69, if necessary after being cut into pieces by means of downstream shears 68.

Par ailleurs, les bobines 11, 13 et 12 sont portés par des vérins permettant leur chargement et leur déchargement. L'ensemble de l'installation repose sur des fondations en béton. Un bâti métallique permet de maintenir et de supporter les différents éléments constitutifs de l'installation.Moreover, the coils 11, 13 and 12 are carried by jacks allowing their loading and unloading. The entire installation is based on concrete foundations. A metal frame allows to maintain and support the various components of the installation.

Sur chacune des figures 2a à 2j on a représenté schématiquement l'installation de laminage de la figure 1, les chiffres de références ayant été repris pour indiquer les mêmes éléments constitutifs. Dans l'exemple représenté, les cages amont 3 et aval 5 (dans le premier sens de défilement) sont du type quarto comportant deux cylindres de travail et deux cylindres de soutien mais pourraient être de tout autre type. La bobineuse première passe 12 et la bobineuse deuxième passe 13 sont schématisées avec leur mandrin contrairement à la dérouleuse première passe 11 qui n'en comporte pas. Les bobines 21, 22 et 23 sont représentées à différentes étapes du procédé d'inspection selon l'invention.On each of Figures 2a to 2j schematically shows the rolling plant of the figure 1 , the reference figures have been included to indicate the same constituent elements. In the example shown, the upstream 3 and downstream 5 cages (in the first direction of travel) are of the quarto type comprising two working cylinders and two support cylinders but could be of any other type. The first winder passes 12 and the second winder 13 passes are schematized with their mandrel unlike the unroller first pass 11 which does not. The coils 21, 22 and 23 are shown at different stages of the inspection process according to the invention.

Sur la figure 2a, une bobine de tôle à laminer 21 est disposée sur la dérouleuse première passe 11 puis déroulée. L'extrémité de tête 101 correspondant à l'extrémité avant de la bande de tôle 100 est engagée entre les cylindres de travail de la cage amont 3. Une fois la bande 100 engagée, les cylindres de travail de la cage amont 3 sont utilisés afin d'appliquer une force de friction permettant l'entraînement de la bande 100. L'extrémité de tête 101 se déplace alors dans un premier sens de défilement en direction de la cage aval 5 comme l'indique la flèche, c'est-à-dire de droite à gauche.On the figure 2a , a roll of sheet metal 21 is disposed on the unrolling first pass 11 and unwound. The leading end 101 corresponding to the front end of the sheet metal strip 100 is engaged between the working rolls of the upstream stand 3. Once the band 100 is engaged, the working rolls of the upstream stand 3 are used to to apply a friction force for driving the band 100. The leading end 101 then moves in a first direction of travel towards the downstream cage 5 as indicated by the arrow, that is to say say from right to left.

Sur la figure 2b, l'extrémité de tête 101, après engagement entre les cylindres de la deuxième cage 5, a été fixée de manière conventionnelle sur le mandrin de la bobineuse première passe 12. Les cylindres de travail des cages 3 et 5 sont serrés sur la bande et entraînés en rotation pour commander le déroulement de la bande de tôle 100 qui, en même temps, est enroulée autour du mandrin de la bobineuse première passe 12 (figure 2c). Au cours de cette première passe, la bobine 21 est débobinée tandis que la bobine 22 est bobinée. La dérouleuse première passe 11 ne comportant pas de mandrin, il est impossible d'appliquer une tension sur la bande 100 lors de la première passe. En conséquence, le taux de réduction souhaité ne peut être réalisé au cours de cette première passe de défilement.On the figure 2b the leading end 101, after engagement between the rolls of the second stand 5, has been conventionally fixed to the mandrel of the first pass winder 12. The work rolls of stands 3 and 5 are clamped on the band and driven in rotation to control the unwinding of the sheet metal strip 100 which, at the same time, is wound around the mandrel of the first pass winder 12 ( Figure 2c ). During this first pass, the coil 21 is unwound while the coil 22 is wound. The first unrolling pass 11 having no mandrel, it is impossible to apply a tension on the band 100 during the first pass. Consequently, the desired reduction rate can not be achieved during this first scrolling pass.

La figure 2d représente schématiquement la fin de la première passe. La bobine 21 est entièrement dévidée et la bande de tôle 100 est enroulée autour du mandrin de la bobineuse première passe 12 formant une bobine 22. La première passe s'achève lorsque l'extrémité de queue 102 de la bande 100 est à proximité de la cage amont 3. Il est avantageux de ne pas désengager l'extrémité de queue 102 en fin de première passe. Par désengagement, il faut entendre que l'extrémité de queue 102 va au-delà de la cage aval 5. La première passe est donc arrêtée au moins lorsque l'extrémité de queue 102 se situe entre les cages. De préférence, la première passe est arrêtée lorsque l'extrémité de queue 102 est encore en amont de la cage amont 3.The figure 2d schematically represents the end of the first pass. The reel 21 is completely unwound and the sheet metal strip 100 is wound around the mandrel of the first rewinder 12 forming a reel 22. The first pass ends when the tail end 102 of the web 100 is near the upstream cage 3. It is advantageous not to disengage the tail end 102 at the end of the first pass. By disengagement, it is meant that the tail end 102 goes beyond the downstream cage 5. The first pass is stopped at least when the tail end 102 is between the cages. Of preferably, the first pass is stopped when the tail end 102 is still upstream of the upstream cage 3.

Le sens de fonctionnement du laminoir 1 est alors inversé de manière à commander le défilement de la bande de tôle 100 dans le sens inverse indiqué par la flèche représentée sur ia figure 2e. Dans un premier temps, les cylindres de travail des cages 3 et 5 sont simplement serrés pour commander le déplacement de la bande 100 de la gauche vers la droite jusqu'à ce que l'on puisse fixer son extrémité avant 102 sur le mandrin de la bobineuse deuxième passe 13.The operating direction of the mill 1 is then reversed so as to control the running of the sheet metal strip 100 in the opposite direction indicated by the arrow shown on ia figure 2e . In a first step, the working rolls of cages 3 and 5 are simply tightened to control the movement of web 100 from left to right until its front end 102 can be fixed to the mandrel of the machine. second pass winder 13.

On peut alors commencer la deuxième passe, illustrée par la figure 2f, la bande 100 se déroulant à partir de la bobine 22 qui fonctionne donc en débobineuse mais peut être freinée de façon à mettre la bande sous tension et réaliser le laminage entre les cylindres des deux cages 5 et 3, l'écartement entre les cylindres étant réglé pour atteindre un taux de réduction adapté. La bande est enroulée pour former une bobine 23 sur l'enrouleur/dérouleur 13 servant de bobineuse. On peut alors réaliser le laminage par passes successives entre les deux bobineuses, première passe 12 et deuxième passe 13, qui sont équipées des moyens nécessaires permettant l'application d'un couple sur leurs mandrins respectifs afin de maintenir la bande de tôle 100 sous tension. Des taux de réduction importants peuvent ainsi être atteints dès la deuxième passe.We can then start the second pass, illustrated by the figure 2f , the strip 100 unwinding from the reel 22 which thus functions as a de-borer but can be braked so as to put the strip under tension and carry out the rolling between the rolls of the two stands 5 and 3, the spacing between the rolls being set to achieve a suitable reduction rate. The strip is wound to form a coil 23 on the reel / unwinder 13 serving as a winder. It is then possible to carry out the rolling in successive passes between the two winders, first pass 12 and second pass 13, which are equipped with the necessary means allowing the application of a torque on their respective mandrels in order to keep the sheet metal strip 100 under tension. . Significant reduction rates can be achieved in the second pass.

Le nombre N de passes du cycle de laminage dépend du taux de réduction à réaliser afin d'obtenir l'épaisseur finale souhaitée.The number N of passes of the rolling cycle depends on the reduction rate to be achieved in order to obtain the desired final thickness.

Cependant, comme indiqué plus haut, seule la partie centrale utile de la bande est laminée à cette épaisseur, les deux longueurs de service qui doivent rester enrouler sur les mandrins des deux enrouleurs/dérouleurs 12, 13 n'étant pas laminés à chaque passe.However, as indicated above, only the useful central portion of the strip is laminated to this thickness, the two lengths of service which must remain wound on the mandrels of the two reels / unwinders 12, 13 not being rolled at each pass.

Selon l'invention, l'inspection va être réalisée sur une section prélevée sur l'une de ces deux longueurs de service qui devraient, de toute façon, être rebutées. Il faut, cependant, que cette section soit une image de la partie utile afin d'en présenter le même aspect et, en particulier, les mêmes marques et empreintes des cylindres.According to the invention, the inspection will be carried out on a section taken on one of these two lengths of service which should, in any case, be rejected. It must, however, that this section is an image of the useful part to present the same aspect and, in particular, the same marks and imprints of the cylinders.

Pour cela, comme le montre schématiquement la figure 2g, à la fin de la dernière passe qui, dans l'exemple représenté, est une passe paire, le laminage est poursuivi entre les cylindres des deux cages 5 et 3, jusqu'à ce que l'extrémité arrière 101, dans ce second sens de défilement de la bande, se libère du mandrin de la débobineuse 12 et arrive à proximité de la cage 5.For that, as schematically shows the figure 2g at the end of the last pass which, in the example shown, is an even pass, the rolling is continued between the rolls of the two stands 5 and 3, until the rear end 101, in this second direction of the strip, is released from the mandrel of the uncoiler 12 and arrives near the cage 5.

La bande restant ainsi serrée entre les cylindres des deux cages 5 et 3, le sens de rotation desdits cylindres est inversé de façon à faire repartir la bande dans le premier sens de défilement, c'est-à-dire de la droite vers la gauche, sur la figure 2h.The band thus remaining clamped between the rolls of the two stands 5 and 3, the direction of rotation of said rolls is reversed so as to restart the band in the first direction of movement, that is to say from right to left , on the figure 2h .

Le défilement, de la droite vers la gauche, est poursuivi jusqu'à ce que l'extrémité de queue 101 de la bande, qui est l'extrémité avant dans ce premier sens de défilement, se trouve à une distance de la cisaille 32, placée en amont de la première cage 3, au moins égale à la longueur d'inspection nécessaire. En pratique, cette longueur d'inspection est, généralement, un peu supérieure à la longueur de service et la bande peut alors être coupée par la cisaille 32, de la façon indiquée sur la figure 2h, suivant une ligne se trouvant dans la partie utile de la bande mais à proximité de son extrémité arrière. Cette partie utile peut donc être enroulée complètement sur la bobineuse 13 pour former la bobine 23 dont seule la tête formant les premières spires enroulées sur le mandrin, devra être rebutée puisqu'elle correspond à la longueur de service non laminée (Figure 2i).The scrolling, from right to left, is continued until the tail end 101 of the strip, which is the front end in this first direction of travel, is at a distance from the shear 32, placed upstream of the first cage 3, at least equal to the required length of inspection. In practice, this inspection length is generally slightly greater than the service length and the band can then be cut by the shear 32, as indicated on the drawing. figure 2h following a line in the useful part of the strip but close to its rear end. This useful part can therefore be wound completely on the winder 13 to form the coil 23, of which only the head forming the first turns wound on the mandrel, will have to be rejected since it corresponds to the non-rolled service length ( Figure 2i ).

La partie restante 105 de la bande, qui est restée serrée entre les cylindres des cages 3 et 5, est entraînée vers la gauche, c'est-à-dire dans le premier sens de défilement et dirigée par un aiguillage vers la table d'inspection 62 représentée sur la figure 1.The remaining portion 105 of the strip, which has remained tight between the rolls of cages 3 and 5, is driven to the left, that is to say in the first direction of movement and directed by a switch to the inspection table 62 shown on the figure 1 .

Cette section 105 correspondant, au moins pour sa plus grande partie, à la longueur de service, est passée deux fois entre les cylindres de travail, respectivement dans le premier sens de défilement de la gauche vers la droite, sur la figure 2g et dans le second sens de défilement, de la droite vers !a gauche, sur les figures 2h, 2i. De plus, même si l'extrémité arrière 101 s'est libérée de la débobineuse 12, la bande est restée sous tension, dans un sens comme dans l'autre, entre les deux cages 5 et 3. Cette partie 105 subit donc, lors de son passage entre les cylindres, les mêmes marques que la partie utile de la bande, ces marques se reproduisant à l'identique à chaque passe. La section prélevée 105 présente donc le même aspect que la bande, ce qui permet de vérifier la qualité de celle-ci.This section 105 corresponding, at least for the most part, to the length of service, is passed twice between the working cylinders, respectively in the first direction of movement from left to right, on the figure 2g and in the second direction of scrolling, from the right to the left, on the Figures 2h, 2i . In addition, even if the rear end 101 has been released from the uncoiler 12, the band has remained energized, in one direction or the other, between the two stands 5 and 3. This part 105 therefore undergoes, when its passage between the cylinders, the same marks as the useful part of the band, these marks reproducing identically to each pass. The sampled section 105 therefore has the same appearance as the strip, which makes it possible to check the quality of the latter.

Sur la figure 2j, l'échantillon 105 est positionné sur la table d'inspection où a lieu l'inspection proprement dite, éventuellement sur les deux faces par retournement de l'échantillon 105. Parallèlement, la bobine 23 est retirée de l'installation de laminage et amenée vers, par exemple, une autre installation pour un traitement ultérieur. De même, pendant l'inspection de l'échantillon 105, une nouvelle bobine 21' constituée d'une nouvelle bande de tôle 100' à laminer est chargée sur la dérouleuse première passe 11 et son extrémité de tête 101' est engagée dans le laminoir 1 de manière à préparer le cycle de laminage suivant.On the figure 2j , the sample 105 is positioned on the inspection table where the actual inspection takes place, possibly on both sides by turning the sample 105. Meanwhile, the coil 23 is removed from the rolling installation and brought to, for example, another installation for further processing. Similarly, during the inspection of the sample 105, a new coil 21 'consisting of a new strip of sheet metal 100' to be rolled is loaded onto the first pass unroller 11 and its leading end 101 'is engaged in the rolling mill 1 so as to prepare the next rolling cycle.

Le procédé d'inspection selon l'invention tire donc partie du fait que la longueur de service non laminée, qui doit être rebutée de toute façon, est utilisée comme échantillon d'inspection car elle comporte les marques et empreintes des cylindres. En effet, bien que n'étant pas laminée à la bonne épaisseur, la longueur non laminée passe entre les cylindres qui laissent donc leurs marques sur les deux faces.The inspection method according to the invention therefore takes advantage of the fact that the non-rolled service length, which must be rejected in any case, is used as an inspection sample because it comprises the marks and impressions of the rolls. Indeed, although not rolled to the right thickness, the unlaminated length passes between the cylinders which leave their marks on both sides.

La longueur d'inspection doit être choisie de manière à comporter au moins une période de chacune des marques des trains de cylindres des cages du laminoir: Donc la longueur d'inspection comporte au moins la longueur non laminée, mais peut également être plus importante si la période d'un des trains de cylindres le nécessite.The length of inspection shall be chosen to include at least one period of each of the rolling mill roll marks: Thus, the length of inspection shall include at least the unlaminated length, but may also be greater if the period of one of the roll trains requires it.

L'invention permet donc d'inspecter en ligne la qualité du laminage en minimisant les pertes de matière laminée à l'épaisseur souhaitée, puisque l'inspection est réalisée sur une partie de la tôle qui aurait du être rebutée quoiqu'il arrive, n'étant pas à la bonne épaisseur. Par ailleurs, l'opération d'inspection ne consomme pas de temps. En effet, comme le montre la figure 2j, lorsque l'inspection du laminage d'un premier cycle a lieu, le cycle de laminage suivant peut être préparé en engageant par exemple l'extrémité de tête 101' de la bobine 21' suivante. La manutention de la bobine 23 produite est également faite de manière synchrone avec l'étape d'inspection. De plus, la mise en oeuvre du procédé d'inspection selon ce qui vient d'être décrit ne nécessite pas ou peu de modifications des installations existantes.The invention thus makes it possible to inspect the quality of rolling on-line by minimizing the losses of rolled material to the desired thickness, since the inspection is carried out on a part of the sheet that should have been discarded, whatever happens. not being the right thickness. In addition, the inspection operation does not consume time. Indeed, as shown in figure 2j when the inspection of the rolling of a first cycle takes place, the following rolling cycle can be prepared by engaging for example the leading end 101 'of the next coil 21'. The handling of the coil 23 produced is also done synchronously with the inspection step. In addition, the implementation of the inspection method as described above does not require or few modifications of existing facilities.

D'autres variantes de réalisation du procédé selon l'invention ainsi que de l'installation de laminage sont possibles.Other alternative embodiments of the method according to the invention as well as the rolling installation are possible.

Par exemple, des cisailles peuvent être situées en amont ou en aval du laminoir, éventuellement entre les cages du laminoir. Dans le cas où des cisailles seraient disposées seulement en aval du laminoir 1, une fois que l'échantillon d'inspection a été séparé du reste de la bande de tôle 100, le laminoir ne pourrait plus servir de moyen d'entraînement de l'échantillon vers la table d'inspection. Il faudrait alors disposer de moyens d'entraînement propres, aptes à déplacer l'échantillon sur la table d'inspection.For example, shears may be located upstream or downstream of the rolling mill, possibly between the stands of the rolling mill. In the case where shears are disposed only downstream of the mill 1, once the inspection sample has been separated from the remainder of the sheet metal strip 100, the mill can no longer serve as a means of driving the sheet. sample to the inspection table. It would then be necessary to have own drive means capable of moving the sample on the inspection table.

Dans ce cas, cependant, si un nombre impair de passes est requis, la table d'inspection pourra être située en aval du laminoir 1 dans le premier sens de défilement, et permettra d'inspecter un échantillon correspondant à la longueur de service enroulée sur l'enrouleur/dérouleur 13 et, se trouvant en queue dans le premier sens de défilement.In this case, however, if an odd number of passes is required, the inspection table may be located downstream of the rolling mill 1 in the first direction of travel, and will inspect a sample corresponding to the length of service wound on the reel / unwinder 13 and, being in line in the first direction of travel.

Dans ce cas, en effet, la table d'inspection peut être placée du même côté que la bobineuse 12 sur laquelle s'enroule la bande. Si l'on dispose d'une cisaille entre la seconde cage 5 et la bobineuse 12, celle-ci peut couper la bande à une distance de son extrémité arrière 102 au moins égale à la longueur d'inspection nécessaire. La bande peut alors être enroulée complètement sur la bobineuse 12 et sa partie arrière, qui constitue la longueur d'inspection, reste serrée entre les cylindres des cages 5 et 3 qui l'entraînent vers la gauche, dans le premier sens de défilement de façon à l'aiguiller vers la table d'inspection. Dans ce cas, la section d'inspection ne passe qu'une seule fois entre les cylindres des deux cages 5 et 3 mais ce seul passage est suffisant pour que les cylindres impriment leurs marques et que la longueur d'inspection présente un aspect représentatif de celui de la partie utile de la bande.In this case, indeed, the inspection table can be placed on the same side as the winder 12 on which the band is wound. If there is a shear between the second cage 5 and the winder 12, the latter can cut the strip at a distance from its rear end 102 at least equal to the required inspection length. The strip can then be wound completely on the reel 12 and its rear part, which constitutes the inspection length, remains tight between the rolls of the stands 5 and 3 which drive it to the left, in the first direction of travel so that to direct him to the inspection table. In this case, the inspection section only passes once between the rolls of the two stands 5 and 3, but this passage is sufficient for the rolls to print and the inspection length has a representative appearance of that of the useful part of the band.

Comme indiqué plus haut, du fait que l'on utilise deux cages réversibles écartées l'une de l'autre, la longueur d'inspection reste tendue entre les deux cages, même après la coupe de la bande.As indicated above, since two reversible cages are used spaced from each other, the inspection length remains tight between the two cages, even after cutting the strip.

Le procédé selon l'invention est, cependant, applicable, à un laminoir comportant une seule cage réversible. Dans ce cas, après s'être libérée de la débobineuse, la partie arrière de la bande n'est plus mise sous tension mais le passage entre les cylindres de travail qui restent serrés sur la bande, permet d'imprimer les mêmes marques sur les deux faces de celle-ci, la longueur d'inspection prélevée sur l'extrémité arrière de la bande et constituant la longueur de service, présentant le même aspect que la partie utile de la bande.The method according to the invention is, however, applicable to a rolling mill comprising a single reversible cage. In this case, after being released from the uncoiler, the rear portion of the strip is no longer energized but the passage between the working rolls which remain tight on the strip, allows to print the same marks on the two faces thereof, the inspection length taken from the rear end of the strip and constituting the length of service, having the same appearance as the useful part of the strip.

Bien que l'invention ait été décrite en référence à un mode de réalisation particulier, elle n'est nullement limitée à ce mode de réalisation. Elle comprend tous les équivalents techniques des moyens décrits ainsi que leurs combinaisons qui entrent dans le cadre de l'invention.Although the invention has been described with reference to a particular embodiment, it is in no way limited to this embodiment. It includes all the technical equivalents of the means described as well as their combinations which come within the scope of the invention.

Claims (14)

  1. Method for inspecting a rolled strip in a reversible rolling plant comprising at least one roll stand (3,5) arranged between two winding/unwinding devices (12, 13) each having a mandrel whereon strip service length is wound into several coils for tensioning the strip, the rolling being performed in several passes until the requested thickness is obtained over the whole length of a useful part between two service lengths maintained wound, at each pass on each of the mandrels,
    characterised in that, at the end of the last roll pass between a winder/unwinder (12) placed upstream of the roll stand in the rolling direction and acting as a decoiler, and a downstream winder/unwinder (13) acting as a coiler, the upstream service length is completely unwound from the upstream decoiler and is subjected to at least one roll pass, the strip being then cut in the vicinity of the end of its useful part, so as to release, at its rear end in the direction of the last pass, a length at least equal to a necessary inspection length (105), at least one part of said inspection length (105) corresponding to the upstream service length which has been rolled at least once and thus providing a picture of the aspect defects of the useful part.
  2. Method according to claim 1, characterised in that, at the end of the rolling of the upstream service length, the rear end thereof is maintained clamped between the working rolls and the rotational direction of said cylinders is then reversed so as to send backwards a sufficient length of strip to sample therein an inspection length (105) separated from the strip by cutting it upstream of the roll stand, in the direction of the last pass, said sampled length being placed on an inspection table and the strip being returned in the direction of the last pass to wind completely on the downstream coiler (13).
  3. Method according to claim 1, characterised in that, at the end of the last roll pass, the strip (100) is cut downstream of the rolling mill (1) at a distance from its rear end corresponding to the inspection length (105) and it is then wound completely on the downstream coiler (13) while leaving an inspection length rolled once which is sent towards the inspection means.
  4. Method according to any one of claims 1 to 3, characterised in that, the roll plant includes a reversible mill having at least one roll stand (2, 3) capable of operating for odd passes in a first rolling direction and for even passes in a reverse direction, said method including the steps wherein:
    - (a) from a reel (21) placed on a first side of the rolling mill, the strip is unwound in a first running direction while passing through the open roll stand and (b) a first end of the leading end of the strip is fastened to a winder-unwinder (12) placed on a second side of the rolling mill and operating as a coiler;
    - (c) during this first pass, the strip is clamped between two working rolls of the roll stand which are driven into rotation in the first running direction for winding the strip on the coiler of the second side of the roll stand, (d) until a second end, at the trailing end of the strip (102), arrives close to the roll stand;
    - (e) the rotational direction of the cylinders is reversed to control the running of the strip in the reverse direction and said second end of the strip is fastened to a winder-unwinder (13) placed on the first side of the rolling mill;
    - the strip is wound on said winder-unwinder (13) of the first side which operates as a coiler, the winder-unwinder (12) of the second side operating as a decoiler and, when a first service length is wound into several coils on said coiler of the first side, the strip is tensioned so as to conduct a rolling of the strip during this second pass (f);
    - the running of the strip is stopped so as to maintain a second service length wound into several coils on the winder-unwinder (12) of the second side;
    - the running direction is still reversed, the winder/unwinder (12) of the second side operating then as a coiler for a third pass with rolling of the strip in the first running direction;
    - the rolling is performed in a plurality of passes, alternately odd in the first running direction and even in the reverse direction, a service length being maintained wound, at each end of the strip, on each of the winders-unwinders,
    - after the end of the last roll pass between a decoiler placed upstream of the rolling mill and a coiler placed downstream, the rolling is continued during this last pass, until the upstream service length placed at the trailing end of the strip, in the direction of this last pass, is released from the upstream decoiler (12) and is rolled at least once (g),
    - (i) the strip is cut at a distance from its rear end at least equal to an inspection length (105), at least one part of said inspection length (105) corresponding to said upstream service length rolled at least once,
    - (j) the inspection length is sent towards inspection means,
    - the strip is wound completely on the downstream coiler (13).
  5. Method according to claim 4, characterised in that it includes, after a first rolling of the upstream service length, the following steps:
    - (g) stopping the rolling before the passage of the rear end (101) of the strip (100) and maintaining it clamped between the working rolls;
    - (h) reversal of the rotational direction of said cylinders for returning the strip upstream,
    - (i) cutting the strip at a distance from its rear end, in the direction of the last pass, at least equal to an inspection length (105),
    - (j) complete winding of the remaining strip on the downstream coiler (13), in the direction of the last pass,
    - sending the inspection length towards inspection means.
  6. Method according to any one of the preceding claims, characterised in that, after the step of releasing one end (101) and before the step consisting in unwinding an inspection length (105), said released end is not totally disengaged from said rolling mill (1).
  7. Method according to any one of the preceding claims, characterised in that said step of unwinding an inspection length (105) is performed by using said rolling mill (1) as a driving means of the sheet metal strip (100).
  8. Method according to any one of the preceding claims, characterised in that said inspection length (105) is conveyed on an inspection table (62) associated with the rolling mill (1) .
  9. Method according to claim 8, characterised in that for inspecting both faces of the inspection length (105), the latter is turned over using a drum (65) placed at one end of said inspection table (62).
  10. Method according to any one of the preceding claims, characterised in that the step of inspecting said inspection length (105) and the step of rejecting the inspection length are performed in parallel with the step of re-winding the strip (100) on the coiler (13) of the last pass.
  11. Method according to any one of the preceding claims, characterised in that it comprises an additional step of positioning a reel (21) of strip to be rolled on said first pass decoiler (11), and in that the step of positioning a reel to be rolled and the engaging step of the leading end (101') for a new rolling cycle are performed in parallel with the step of inspecting the inspection length (105) and the step of rejecting the inspection length of the preceding rolling cycle.
  12. Method according to any one of the preceding claims, characterised in that said inspection length (105) is at a minimum equal to a length enabling to observe at least one period of the marks left by the trains of rolls provided on said rolling mill (1).
  13. Method according to any one of the preceding claims, characterised in that the roll plant is fitted with shears (32), and in that the step of cutting said inspection length (105) is performed when, in the step of unwinding an inspection length, the distance between said released end and said shears is equal to the necessary inspection length.
  14. Method according to any one of the preceding claims, characterised in that it applies to a reversible rolling mill (11) including two rolling roll stands (2, 3) spaced apart from one another, the assembly of both roll stands being placed between two winding/unwinding devices (12, 13) acting alternately as a decoiler and as a coiler.
EP06794198A 2005-07-22 2006-07-21 Inspection method Expired - Fee Related EP1917113B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0552283A FR2888763B1 (en) 2005-07-22 2005-07-22 INSPECTION METHOD AND ASSOCIATED INSTALLATION
PCT/FR2006/001793 WO2007010148A1 (en) 2005-07-22 2006-07-21 Inspection method

Publications (2)

Publication Number Publication Date
EP1917113A1 EP1917113A1 (en) 2008-05-07
EP1917113B1 true EP1917113B1 (en) 2010-03-03

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EP06794198A Expired - Fee Related EP1917113B1 (en) 2005-07-22 2006-07-21 Inspection method

Country Status (8)

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US (1) US7980109B2 (en)
EP (1) EP1917113B1 (en)
CN (1) CN101227985B (en)
BR (1) BRPI0613609A2 (en)
DE (1) DE602006012689D1 (en)
ES (1) ES2339279T3 (en)
FR (1) FR2888763B1 (en)
WO (1) WO2007010148A1 (en)

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DE102007031333A1 (en) * 2007-07-05 2009-01-15 Siemens Ag Rolling of a strip in a rolling train using the last stand of the rolling train as Zugverringerer
JP5028496B2 (en) * 2008-10-17 2012-09-19 三菱日立製鉄機械株式会社 Strip front and back inspection apparatus and inspection method
EP2527052A1 (en) * 2011-05-24 2012-11-28 Siemens Aktiengesellschaft Operating method for a mill train
DE102011078150A1 (en) * 2011-06-08 2012-12-13 Sms Siemag Ag Method, computer program and rolling mill for rolling a metal strip
DE102011078829A1 (en) * 2011-07-07 2013-01-10 ACHENBACH BUSCHHüTTEN GMBH Process for the production of magnesium tape
EP2664390B1 (en) * 2012-05-15 2015-11-18 Cockerill Maintenance & Ingenierie S.A. Installation and output method of tandem mill with winding carousel coupled with in-line inspection
BE1021536B1 (en) * 2012-02-06 2015-12-09 Cockerill Maintenance & Ingenierie S.A. INSTALLATION AND METHOD OF TANDEM ROLLER OUTPUT WITH COUPLED WINDING CARROUSEL WITH ONLINE INSPECTION (I)
EP3099431B1 (en) * 2014-01-27 2019-11-20 Danieli & C. Officine Meccaniche S.p.A. Station for inspecting rolled strips wound in coils
CN104985007B (en) * 2015-07-24 2017-05-17 东北大学 Prediction method for flaw length of Cu-Al sandwich rolling-bonded band head
CN105081985B (en) * 2015-08-19 2018-07-10 秦皇岛树诚科技有限公司 A kind of steel band mechanical scale-removing apparatus

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DE19549208A1 (en) * 1995-12-30 1997-07-03 Schloemann Siemag Ag Process and plant for hot rolling strips
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Also Published As

Publication number Publication date
US20080165351A1 (en) 2008-07-10
CN101227985B (en) 2011-06-08
FR2888763A1 (en) 2007-01-26
US7980109B2 (en) 2011-07-19
ES2339279T3 (en) 2010-05-18
FR2888763B1 (en) 2008-10-03
CN101227985A (en) 2008-07-23
DE602006012689D1 (en) 2010-04-15
BRPI0613609A2 (en) 2011-05-17
EP1917113A1 (en) 2008-05-07
WO2007010148A1 (en) 2007-01-25

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