Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/68—Camber or steering control for strip, sheets or plates, e.g. preventing meandering
• • 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
  • B21B2261/10—Cross-sectional area
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
  • B21B37/58—Roll-force control; Roll-gap control
  • B21B37/62—Roll-force control; Roll-gap control by control of a hydraulic adjusting device
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B39/00—Arrangements for moving, supporting, or positioning work, or controlling its movement, combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
  • B21B39/02—Feeding or supporting work; Braking or tensioning arrangements, e.g. threading arrangements
  • B21B39/10—Arrangement or installation of feeding rollers in rolling stands

Definitions

• the invention relates to a method for operating a roll stand for rolling a metal strip.
• the roll stand has lateral guide rails arranged on at least one of the two sides at the inlet and/or outlet--seen in the direction of transport of the metal strip--for guiding the metal strip.
• EP 698428 B1 discloses a method for thickness control based on a position measurement in the bending cylinders of the roll stand.
• the international patent application WO 03/053604 describes a method for controlling the roll gap of the roll stand, it being recommended that a position or travel sensor be assigned to each bending cylinder in the roll stand.
• the measured values provided by the position or displacement encoder enable the roll gap to be set more precisely in order to achieve optimum threading in or out of the metal strip and optimum rolling of the rolled metal strip with a desired flatness and a required profile.
• the application explains the connection between the inclined position of the roll gap and the lateral running of the metal strip to be rolled out of the roll gap of the roll stand.
• the international publication WO 2006/119984 discloses a method of a device for specifically influencing the geometry of the pre-strip in a roll stand.
• this patent application claims a method for hot rolling of rolling stock, with both a swivel control with a dynamic adjustment of the roughing stand and a position and force control of lateral guides being proposed for the course control of the rolling stock upstream and downstream of a roughing stand.
• the regulation of the employment and the regulation of the employment of the lateral guides are linked in such a way that a saber-shaped or wedged slab is formed into a straight and wedge-free pre-strip in one or more passes in a targeted manner, reversing or in continuous operation.
• the object of the invention is to further develop a known method for operating a roll stand with an inclined position control and a force or position control coupled thereto for the control of lateral guides so that the force or position setpoints for the control of both the adjustment and of the lateral guide rails can be better determined with a view to avoiding sagging in the metal strip at the outlet of the roll stand.
• the solution to the task is that the force or position setpoints for the control of the lateral guides according to the for Pivot position control already determined actual wedge quality and / or calculated according to the determined actual offset.
• the claimed basic control loop in the form of the swivel control is used to detect and eliminate a wedge shape of the metal strip to be rolled. Any wedge shape in the incoming metal strip is compensated for by a swivel specification, i.e. the adjusting cylinders of the roll stand are given different values with regard to their setting position or their setting force, in order to compensate for different thickness values of the metal strip in its width direction.
• a swivel specification i.e. the adjusting cylinders of the roll stand are given different values with regard to their setting position or their setting force, in order to compensate for different thickness values of the metal strip in its width direction.
• the claimed method enables resource-efficient production in hot rolling mills for flat products. It enables an increase in productivity and material output by reducing downtimes.
• the properties and quality of the metal strip to be rolled are optimized and the plant operator is relieved of the burden of controlling the strip run.
• the claimed coupling step is only carried out if either the determined actual wedgeness is greater than a specified maximum permissible wedgeness and/or when the determined actual offset of the metal strip after rolling is inadmissible because it is greater than a specified maximum permissible eccentricity .
• the claimed position or force regulation of the lateral guides activated in addition to the claimed swivel regulation.
• the lateral guides are also adjusted with a correction value with regard to a specified target position or a specified target force, depending on the current actuator of the lateral guides.
• the side guides should be individually controllable on each side.
• the aim of the pivoting control is that the control difference between the ascertained actual angularity of the metal strip and the specified desired angularity becomes as close to zero as possible. This means that the thickness of the metal strip to be rolled should be the same on the drive side and the operating side of the roll stand, ie on the left and right edge, if possible, unless certain deviations are tolerated.
• the actual keyness and/or the actual offset are determined indirectly by deriving these actual values from at least one of the following directly measurable variables.
• This is, for example, the difference between the rolling force, ie the difference between the rolling force on the drive side and the rolling force on the operator side, recorded by pressure measurement, on the adjusting cylinders of the roll stand.
• the actual positions of the adjusting cylinders and finally the measurement of the position of the bending cylinders in the roll stand close to the roll gap are also directly comparable as measured variables.
• measuring the position of the bending cylinders close to the roll gap enables a very precise statement to be made about the derivation of the actual wedge shape.
• the wedgeness can be measured directly. At least one of the four measurements mentioned must be carried out in order to be able to derive any statement about the actual keyness from these measured values. Because the measured values mentioned also provide information about the centric or eccentric position of the metal strip in the rolling dispute, a statement about the central position or the actual offset of the metal strip can also be derived in addition or as an alternative.
• pairs of values can be stored in tabular form, so that, for example, a wedge value of x mm is assigned a displacement of the ruler by y mm (nominal position); or - an xy steep curve can be stored in an alternative embodiment, which is based on a calculation formula taking into account
• Forming of the metal strip in the roll stand is taken into account for the inlet-side conditions to be set.
• the invention primarily provides that the cornering guides are simply controlled via actuators with the previously specified desired values (without a feedback control loop). Alternatively, however, the control can also take place in the form of a position or force control loop.
• the method according to the invention can be used both for roughing mills and for finishing mills.
• the description is accompanied by a figure which schematically illustrates the method according to the invention.
• the top half of the figure contains an illustration of the swivel control 100 and the bottom half of the figure shows the actuation 300 of the lateral guide rails 350 .
• the swivel control 100 and the control 300 of the lateral guide rails are coupled via a block 170 for deriving or calculating the actual Wedge of the metal strip and/or its actual offset from directly measured values and an admissibility query 200.
• Panning control 100 is represented by a classic control loop. This consists of a calculation unit 110 for calculating a specified target wedge size or a target swivel value of the work rolls for setting the roll gap in roll stand 150. As part of the swivel control, the calculated target wedge size is compared with the actual value calculated in block 170 - keenness. The difference between the desired keying and the actual keying is determined in the comparator 120 and output to a downstream controller 130 as the so-called control difference e. The controller 130 calculates an actuating signal for an actuator 140 from the control difference e as an input variable; here, in the swivel control, the actuator is formed by the adjusting cylinders of the work rolls in the roll stand.
• Said swivel control 100 is characterized by feedback, in which, in a further method step, the position of the adjusting cylinders (step 160-2) and/or the position of the bending cylinders of the roll stand (method step 160-1) and/or the differential force of the adjusting cylinders ( Method step 160-3) is measured directly in order to derive the actual wedge quality and/or the actual offset from this in the said block 170 by calculation, i.e. to record it indirectly.
• the actual keyness can be obtained from a direct measured value acquisition on the metal strip (160-4). The same applies to measuring the eccentricity of the metal strip (160-5)
• a subsequent query step 200 the ascertained actual offset and/or the ascertained actual keyness are checked to see whether they are permissible, ie whether they are each below predetermined maximum limit values. If both actual values are permissible in this respect, there is no special activation of the lateral guide rails 350 according to the invention; but these remain rather in permanently set guide positions for central guidance of the strip in the roll gap. If the admissibility query is answered in the affirmative, this means that no impermissibly large sagging is detected or expected in the metal strip exiting the roll stand 150 and that therefore no correction of the strip run of the metal strip by the side guides is required.
• the situation is different if one of the two actual values, i.e. the determined actual wedgeness or the determined actual offset of the outgoing metal strip, exceeds the specified maximum permissible limit value. Then a correction of the strip run of the metal strip is required by the lateral guides.
• the lateral guide rails 350 can be controlled by position or by force. For this purpose, a position setpoint is calculated in a position calculation unit 310, to which the cornering guide 350 is adjusted with the aid of an actuator 340, for example a hydraulic cylinder.
• a force calculation unit 310' can be used to calculate a force setpoint for a cornering ruler 350, with the ruler 350 then being adjusted or turned to the force setpoint with the aid of the actuator 340.
• the adjustment or control of the lateral guides 350 takes place without feedback, i.e. within the framework of a simple control as just described.
• the adjustment of the lateral guide rails 350 can also take place in the form of a position control or a force control.
• position control the calculated target position of the respective cornering guide would be compared with an actual position of cornering guide 350 previously measured in a method step 360 in order to determine a position control difference e p therefrom.
• the position control difference would be given as an input variable to a position controller 330, which uses it to determine a position control signal for the actuator 340.
• the actuator 340 would then become the cornering ruler 350 according to the determined position control signal.
• the setpoint force calculated in calculation step 310' would be compared with an actual force previously determined by measurement in a measuring step 360' in a comparison device 320' in order to calculate a force control difference bk therefrom.
• This force control difference would be given as an input variable to a force controller 330 ′, which uses it to determine a force control signal for the actuator 340 .
• This actuator 340 then controls the lateral guide 350 according to the said force control signal.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Control Of Metal Rolling (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=82067515

Family Applications (1)

Country Status (5)

Family Cites Families (6)

• 2021
  • 2021-05-21 DE DE102021205275.4A patent/DE102021205275A1/de active Pending
• 2022
  • 2022-05-19 EP EP22730726.1A patent/EP4341016A1/de active Pending
  • 2022-05-19 CN CN202280036178.4A patent/CN117500618A/zh active Pending
  • 2022-05-19 JP JP2023571876A patent/JP2024519382A/ja active Pending
  • 2022-05-19 WO PCT/EP2022/063555 patent/WO2022243425A1/de active Application Filing

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