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
  • B21B2263/00—Shape of product
  • B21B2263/02—Profile, e.g. of plate, hot strip, sections
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2263/00—Shape of product
  • B21B2263/04—Flatness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B2273/00—Path parameters
  • B21B2273/04—Lateral deviation, meandering, camber of product
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B31/00—Rolling stand structures; Mounting, adjusting, or interchanging rolls, roll mountings, or stand frames
  • B21B31/16—Adjusting or positioning rolls
  • B21B31/18—Adjusting or positioning rolls by moving rolls axially
  • B21B31/185—Adjusting or positioning rolls by moving rolls axially and by crossing rolls
• • 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
  • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
• • 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
  • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
  • B21B37/38—Control of flatness or profile during rolling of strip, sheets or plates using roll bending
• • 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
• • 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
• • 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
  • B21B38/04—Methods or devices for measuring, detecting or monitoring specially adapted for metal-rolling mills, e.g. position detection, inspection of the product for measuring thickness, width, diameter or other transverse dimensions of the product

Definitions

• the invention relates to a concept for a model-based stripline control for a hot strip mill, in particular a finishing train.
• a hot strip mill in particular a finishing train, comprises a plurality of rolling stands Gi, G2, G3,... G n, which are to be rolled, typically a metal strip such as a steel, aluminum, copper or generally a non-ferrous metal strip , wherein it can be achieved by means of conventional control methods that the rolled strip has a desired final temperature and a desired final thickness.
• Other relevant parameters for assessing the rolling quality are, for example, the profile, the contour and the flatness of the strip. In this context, the
• the band profile or the “profile value” of the band indicates the deviation of the band thickness at the band edges from the band thickness in the band center.
• the term “tape thickness contour” is understood to mean the strip thickness profile over the strip width minus the strip thickness in the middle of the strip.
• the strip thickness contour can be split into one with respect to the center of the strip symmetrical and one asymmetric portion.
• the asymmetric component is called “tape thickness wedge”.
• flatness is used synonymously with the internal stresses prevailing in the strip, regardless of whether or not these internal stresses lead to visible distortions of the metal strip.
• the tape may have a temperature gradient across the tape, the tape may enter the nip off-center, or the nip itself may be wedge-shaped. Also combinations of these (and other) causes are possible.
• the strip shape in the following intermediate stand section between the stands G ⁇ and Gi + i will generally not be straight but saber-shaped.
• the saber-shaped course depends on whether the band is clamped on only one side in a scaffold (when threading in or out of the scaffold) or on both sides of two successive scaffolds (when rolling the main part of the tape, ie with the exception of tape head and tape foot).
• the stripline control actuators are used on the individual stands G ⁇ the rolling mill, which influence the shape of the roll gap - and thus the strip thickness profile - asymmetrically over the bandwidth with respect to the center of the frame or the center of the belt.
• Such actuators are, for example, pivoting and asymmetric bending forces.
• symmetrical actuators are provided, for example. Symmetrical bending forces, means for the axial displacement of so-called. CVC work rolls (rolls with S-shaped cut) and / or so-called. "Pair crossing". These symmetrical actuators are used for profile and flatness control.
• An automatic, model-based method or a device for profile and flatness control is disclosed in DE 102 11 623 AI.
• a concept of a complete, model-based control method for the stripline control of the rolling train is given.
• a method is presented that can be used to calculate the setpoint values of the asymmetrical rolling stand actuators for the stripline control.
• the process is an iterative process, which has five individual steps per process cycle:
• Speed wedges (v 'fk)) are compared with the desired speed wedges fk)) specified in the first step,
• G ⁇ applied rolling force distributions f ⁇ (z; k) are determined for each framework by means of material flow models, whereby each framework G ⁇ is assigned a material flow model.
• the target contour Ki (z; k) is determined for the tape drive actuators, wherein
• the actuator setpoint values are calculated from the target contour Ki (z; k).
• the band thickness contour ⁇ ⁇ (z; k) is measured after the last framework G n ,
• the setpoint speed wedges v.sub.10 (k) to be specified are determined in a control loop from the setpoint
• the following data is supplied to the band flatness model assigned to the framework G ⁇ :
• the same data is fed to the material flow models as the band flatness models. Additionally serve as input variables of the material flow models friction parameters R serve, which describe the friction conditions in the longitudinal and transverse direction in the nip.
• friction parameters R serve, which describe the friction conditions in the longitudinal and transverse direction in the nip.
• the thus corrected residual strip thickness profile is subsequently used to determine the target contour Ki (z; k).
• a computer program product according to the invention for carrying out the method according to the invention is proposed as well as a control computer programmed for the computer program product for a rolling train with at least two rolling stands G ⁇ .
• the inventive solution bpsw. the advantages that, after successful piloting of a plant for downstream plants, shorter commissioning and service times are required and that a better extrapolability to a new product range is possible.
• Figure 1 is a schematic representation of a
• Figure 2 is a schematic representation of the rolling mill for
• Figure 3 is a schematic representation of the rolling mill for
• Figure 4 is a schematic representation of the rolling mill for
• Figure 5 is a schematic representation of the rolling mill for
• the rolling train should have n stands, of which only the first two stands Gi, G 2 and the last two stands G n -i and G n are shown.
• a rolling train 1 for rolling a metal strip 10 is controlled by a control computer 2.
• the mode of operation of the control computer 2 is determined by a computer program product 2 ', with which the control computer 2 is programmed.
• the following is based on a Cartesian coordinate system, wherein the x-axis of the coordinate system corresponds to the running direction of the belt 10, the y-axis indicates the belt thickness direction and the z-axis in the direction across the belt 10 and in the direction of the longitudinal axes of the rollers 21 ⁇ the frameworks G ⁇ is oriented.
• the belt 10 is in the rolling mill 1 in a Rolling direction x rolled.
• Each gantry G ⁇ has at least work rolls 21i and possibly (in FIG. 1 but not shown) also support rolls.
• each scaffolding Gi a scaffold controller 30 ⁇ is provided setpoints for only indicated in Figure 1 asymmetric actuators 22i or "actuators" specified, which ultimately act on the rollers 21i and so the desired target shape or To realize the contour of the respective roll gap.
• the frame controllers 30 ⁇ regulate the actuators 22 ⁇ according to the specified setpoints. The basic interaction between the actuators 22i or actuators, the rollers and the resulting nip can be assumed to be known.
• the nominal values for each rolling stand G ⁇ influence an outlet-saprificed nip course which is established between the work rolls 21i - in interaction with the metal strip located between the work rolls.
• the outlet-side roll gap course corresponds to a run-out contour of the strip 10.
• the setpoint values for the actuators 22 ⁇ must therefore be determined in such a way that the roll gap curve, which corresponds to the desired outlet-soaping strip thickness contour, results.
• control calculator 2 determines the setpoint values from the input variables supplied to it.
• the strip thickness contour ⁇ ( ⁇ ) which, depending on the position z, indicates the thickness of the strip 10, ie its extension in the y direction minus the strip center thickness, can be approximately approximated by a second degree polynomial, with the exception of the strip edges:
• the coefficient ⁇ describes the wedging of the band 10 or the band thickness contour.
• the coefficient v- describes a speed wedge or a material flow wedging, which leads to the initially described saber formation of the band 10, while the coefficient vi 2) is a measure of the flatness or unevenness of the band 10.
• vi 2) > 0 edge waves
• vi 2) ⁇ 0 means center waves.
• a calculation cycle k of the iterative method according to the invention has five individual steps 1) to 5), which are executed, for example, with the aid of a computer program on the control computer 2 (in the figures, the parameters "k" and "z” used hereinafter are for the sake of clarity not listed) : Step 1)
• the eccentricity d ⁇ _i of the strip 10 before each gantry G ⁇ is preferably measured optically, for example by means of a laser or camera system.
• the eccentricity d n of the strip after the last stand G n no additional measuring device is required, because this size can be determined by means of the (usually traversing) strip thickness contour measuring device after the last stand.
• band thickness contour ⁇ ( ⁇ ) in front of the first gantry Gi is either measured online or estimates are used for ⁇ ( ⁇ ), which are based, for example, on isolated offline or hand measurements.
• Velocity equations calculated at the effluents of the frameworks G ⁇ , where each framework G ⁇ is assigned a model 40 ⁇ .
• Models 40 ⁇ as well as other models used below are implemented in the computer program.
• the model 40 ⁇ is an extension of the model described in DE 102 11 623 A1 and designated there as "flatness estimator” or its approximation function with additional consideration of asymmetric effects.
• the model 40 ⁇ associated with framework G ⁇ is supplied with the following data:
• this comparison shows that the computation values for the velocity profiles Vi (z; k) are not within a tolerance range, ie between a maximum and a minimum value, around these nominal values, the band thickness contours ⁇ ( ⁇ ) to 0 n -i (z; k) is modified until the comparison gives a sufficient match.
• the comparison reveals that the calculated values for the velocity profiles v ⁇ (z; k) are actually within the tolerance range around the target values, the method goes to step 3), where the band thickness contours determined in the context of the described comparison 9 ⁇ ( z; k) continue to be used.
• Each framework G ⁇ is a physical material flow model 50i (or a look-up table) of a such material flow model) to which the same data as the model 40 ⁇ in step 2) are supplied.
• the material flow model 50 ⁇ receives as input variables from a unit 51 friction parameters R, which describe the different friction conditions in the longitudinal and transverse direction in the roll gap.
• the friction parameters R are model adaptation parameters that are determined so that the overall algorithm predicts the measured strip thickness contour and the measured strip flatness after the last stand as well as possible.
• the material flow models 50 ⁇ model the physical behavior of the belt 10 in the nip of the gantry G ⁇ .
• the material flow models 50 ⁇ are used to determine the rolling force distributions fi (z; k) based on the above input data.
• the respective material flow model 50i determines for a gantry G ⁇ the line load distribution f ⁇ (z) between strip and work rolls.
• the integral of f ⁇ (z) over the bandwidth gives the rolling force in the framework G ⁇ .
• the friction parameters R are therefore the main Model1 adaptation parameters.
• FIG. 4 shows the further processing of the rolling force distributions fi (z; k) determined in step 3) of the cycle k.
• These rolling force distributions are supplied for each framework G ⁇ a computing unit 70 associated with the stand G ⁇ in which the flattening Ai (z, k) of the work rolls in the framework G ⁇ connected to the rolling force distributions f ⁇ (z) is determined by means of a work roll flattening model 71 is calculated.
• This flattening Ai (z; k) is subtracted from the strip thickness contour 9 ⁇ (z; k) at the outlet of the stand G ⁇ in a subtracter 72, ie in the subtracter 72 ⁇ a residual strip thickness profile ⁇ ⁇ (z; k ) - ⁇ (z; k).
• 73 ⁇ 75 ⁇ correction values a ⁇ (z; k), b ⁇ (z; k), c ⁇ (z; k) can be subtracted in further subtractors, where a ⁇ (z; k) the initial contour of the work rolls (ie, the finish), b ⁇ (z; k) represents the current calculated thermal and wear crown, and c ⁇ (z; k) describes the contour of the symmetrical profile and planarity actuators of the stand Gi.
• the current eccentricity d ⁇ (k) of the band is taken into account.
• the remaining band thickness contour is the target contour Ki (z; k) to be adjusted by means of the band-winder actuators 22 ⁇ of the gantry G ⁇ .
• the arithmetic unit 70 ⁇ thus ultimately supplies this target contour K ⁇ (z; k).
• Tape running actuators are present, for example. Panning and asymmetric bending, can in the optimization step
• Step 5 the optimal combination of these actuators are determined.

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Publications (1)

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Citations (3)

• 2009
  • 2009-09-29 DE DE102009043400A patent/DE102009043400A1/de not_active Withdrawn
• 2010
  • 2010-08-06 WO PCT/EP2010/061516 patent/WO2011038965A1/de active Application Filing
  • 2010-08-06 CN CN201080043473XA patent/CN102510779A/zh active Pending
  • 2010-08-06 EP EP10742814A patent/EP2483005A1/de not_active Withdrawn
  • 2010-08-06 BR BR112012007100A patent/BR112012007100A2/pt not_active IP Right Cessation
• 2012
  • 2012-03-06 IN IN2028DEN2012 patent/IN2012DN02028A/en unknown

Patent Citations (3)

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