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
  • B21B37/28—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
• • 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
  • B21B13/023—Metal-rolling stands, i.e. an assembly composed of a stand frame, rolls, and accessories with axes of rolls arranged horizontally the axis of the rolls being other than perpendicular to the direction of movement of the product, e.g. cross-rolling

Definitions

• the power can be controlled on the assumption that the upper and lower mill stiffness is equal. Due to the detected load deviation due to the condition of the contact surface of the rack, the condition of the bearing maintenance, etc. There is a problem that the unbalance of the detected load cannot be separated strictly from an eccentric load due to thrust or an eccentric load due to the deformation behavior of the material to be rolled.
• the present invention has been achieved in view of the above problems. That is, the first object of the present invention is to control the thickness and the edge with high precision by automatically separating and canceling the load imbalance described above in the case of automatically controlling the thickness. It is to be.
• a second object of the present invention is to accurately control the sheet material while grasping the condition of the above-mentioned material to be rolled in the middle of the pass when automatically controlling the sheet crown and shape, and correcting and calculating each pass.
• the purpose is to make it possible to control the shape of the object by predicting its shape.
• the gist of the present invention is as follows.
• a roll set having upper and lower backup rolls and work rolls, each intersecting relatively in a plane parallel to the rolled material, and having a roll bending control device at each end of the roll.
• the upper roll set and the lower roll set are used to reverse the sheet material by a reverse rolling mill having a control device that relatively intersects in a plane parallel to the rolled material.
• determining the pass schedule for rolling Calculate the area that satisfies both the mechanical crown allowable range judged from the shape and the mechanical crown allowable range judged from the equipment capacity, and sequentially pile up from the bottom so that the maximum allowable rolling load is obtained.
• a method for determining a reverse rolling schedule of a pair-aque mill comprising determining a sheet thickness schedule, and simultaneously determining a rolling and crossing angle schedule of the shortest number of passes satisfying a shape.
• FIG. 3 is a flowchart showing the contents of the path schedule determination method of the present invention.
• FIG. 4 is a graph showing a chamber generated in the conventional thick plate rolling and a chamber generated in the embodiment of the present invention.
• FIG. 5 is a block diagram showing components of a rolling mill and a controller according to one embodiment of the present invention.
• FIG. 7 is a flowchart showing the contents of the previous path actual calculation and learning calculation processing of the adaptive control calculation processing section 11B shown in FIG.
• FIG. 8 is a flowchart showing the next path setting calculation processing of the adaptive control calculation processing section 11B shown in FIG.
• FIG. 9 is a block diagram showing the contents of the dynamic shape control processing of the plant controller 13 shown in FIG.
• FIG. 10 shows the dynamics of the plant controller 13 shown in Fig. 5.
• FIG. 4 is a block diagram showing a configuration of a lock shape control function.
• FIG. 11 is a time chart showing the timing of various arithmetic processes included in the shape control of the present invention.
• FIG. 12 is a graph showing (a) the actual crown ratio value and (b) the cross angle setting value according to the present invention and the conventional shape control.
• FIG. 13 is a graph showing the frequency of occurrence of the crown ratio change amount of the final pass by (a) the present invention and (b) the conventional shape control.
• FIG. 14 is a graph showing the number of passes, (a) rolling load, (b) cross angle, and (c) crown ratio of the present invention and the conventional method.
• the first invention of the present invention is based on the detection results of the vertical load detection opening cell and the thrust load detection load cell, and the actual rolling actual load excluding the influence of the thrust load and the left and right
• the load difference is calculated, and the sheet thickness and the camber are controlled based on the detected value and the calculated value.
• FIG. 1 shows the front view of the pair cross rolling mill and the load acting on the rolling mill and rolls during material rolling.
• Thrust load in the roll axis direction F
• the loads P and F generated from these materials are detected by the load cells 1 and 6 via a single crawl 5 to a knock-up roll 2 or a work roll 5 to a work roll chick 4, respectively.
• the material 7 to be rolled moves in the roll axis direction.
• P is not always distributed equally to the left and right because the center position deviates by a or the material has a left-right plastic resistance deviation.
• the basic formulas (1) to (8) are established from the load balance formula and the rotational moment formula centered on the point A between the left and right load cells.
• PT DS -PTws F-(1 / L) (2 d (I-a- ⁇ ) + DB (1 —)
• PT DS -PTWS FTWR (DW / LK 4-3 ⁇ ) / ⁇ + (2 Pa / L)
• F (3 ⁇ P m / 2) + (3 F WR / 4) (20) becomes, for example, the F ⁇ 375ton when the.
• the thrust load on backup roll 2 (BUR) is
• ⁇ 4 / [6 (A Pm ZFwR) +3] (26) can be obtained by such an operation.
• a vertical load and a lateral load are detected by using a rolling load detecting opening / closing cell 1 arranged on the upper, lower, left and right sides and a thrust load detecting load cell 6 acting on the work roll 2.
• the true load P received from the material 7 and the left-right load difference P REF are calculated according to the above equations (22) to (26), and the thrust load F and the like are calculated.
• the reflection (feedback: FB) of the calculated load, etc. on the sheet thickness and edge control is shown below.
• the FB for control can be broadly divided into two from control timing.
• Fig. 2 shows the system configuration that performs this preset control.
• the process computer 11 which receives the information required for rolling by the business computer 12, first determines the rolling schedule for all passes in advance (pass schedule calculation unit).
• the “adaptive control calculation unit” calculates preset information for controlling the rolling mill for each pass, and transmits the information to the sequencer 10.
• the sequencer 10 receives the set value for each pass from the process computer 11 and converts it into a signal for performing the actual rolling position control, drives the hydraulic equipment and the electric motor of the rolling mill, Set to pressure.
• the above is the outline of the preset control.
• the process computer 11 stores the rolling results and sensor detection values of the immediately preceding pass or the pass including the previous pass, and the learning calculation unit and the roll to reflect the results in the setting calculation of this pass. It has a roll profile calculator for estimating changes over time due to wear and thermal expansion.
• the process computer 11 that has received the detection information of the load cells 1 and 6 in the previous pass calculates the true load from the material in the previous pass from the equations (22) to (26) shown above. I do.
• Thrust load error E F F ac / F cal
• the above is the content to learn and correct the setting calculation for the next material from the pass information (rolling actual value & detected value) of the previous pass.
• the load that the material actually applies to the rolling mill is fed back to the thickness control, and the reliability of the set values for the thickness control after the next pass increases.
• the accuracy of the rolled sheet thickness increases.
• Equation (30) calculates the difference in mill elongation due to the load imbalance using Equation (30). Calculate and set in advance the left and right roll gaps so that the mill elongation deviation is canceled by a preset. This significantly reduces the number of members.
• the second and third inventions of the present invention achieve a predetermined plate crown for flattening the final shape of the plate material in recalculating the roll gap setting value when rolling the material.
• the actual plate crown is calculated in real time in accordance with the rolling load fluctuations in the plate, and a single-pending control is performed.At the end of the pass, the plate crown is calculated from the actual roll banding amount of the previous pass. This is to control the shape of the plate by correcting the calculation amount of the pattern and reflecting it on the set value of the cross angle after the next pass.
• the shape prediction value of the path is corrected based on the actual roll bending amount of the pass, and
• the plate shape is controlled by correcting the plate crown prediction value, recalculating the target mechanical crown amount after the next pass, and reflecting it in the cross angle setting value.
• the crown estimation error caused by the preset control of the cross angle based on the predicted load is measured by real-time measurement of the actually measured load while controlling the inside of the bar by roll bending. It is possible to perform absorption and capture, and it is possible to perform accurate crank control.
• the fourth invention of the present invention when determining the pass schedule for rolling a sheet by a reverse rolling mill having a function of crossing the upper and lower rolls in pairs, a conventional “load-constraining path for shape adjustment” + The concept of separating the "pass rolling at full load” or the concept of adjusting the load distribution for shape adjustment by setting the number of passes in advance is eliminated.
• the shape, crown and load (reduction) schedule of the rolled material are calculated and determined at the same time for each pass. Determine the pass schedule that can be rolled at the maximum value. Since the number of passes is automatically adjusted in accordance with the shape control ability, the ability to vary the number of passes in the reverse rolling mill can be sufficiently exhibited.
• the upper and lower limits of the permissible steepness of the pass and the target values are given from the strip width and the exit thickness of the rolled material.
• the values of I a and m are basically 0, and the values of I ma , and ⁇ min are parameters representing the allowable range of the shape for each rolled material size, and are determined according to the operating conditions or the required flatness of the steel sheet. Determined empirically. Using this ⁇ value,
• Ch c l-P + c 2-F B + E + C 3 (34)
• E amount of mechanical crown formed by roll crossing angle
• c1 mechanic crown influence coefficient by rolling load
• c 2 mechanical crown influence coefficient by bending load
• c 3 mechanical crown amount formed by roll profile
• the range that satisfies both the mechanical crown restriction range from the shape according to Eq. (33) and the mechanical crown allowable range from the equipment load according to Eq. (34) is the true mechanical crown allowable range for this path. Is determined. Furthermore, the MCK aim is corrected so as to be within this range, and the true mechanical crown aim value MC aim is determined (S30).
• MC aim c 1 ⁇ fp ( r) + c 2 - F B + fe (2 ⁇ ) because a + c 3,
• reduction ratio r is 2 theta pent '' can be searched determined by I ing load F B.
• the bending efficiency FB is determined to be 20 so that the rolling reduction r is maximized in order to favor high-efficiency rolling in operation. It is also possible to reflect the other operating conditions using an evaluation function or the like, and to find the optimal combination by a linear programming method or the like.
• the pass schedule determination method determines whether the scheduled thickness at the start of rolling cannot be changed during the preparation of this pass schedule. If the scheduled thickness at the start of rolling cannot be changed during the preparation of this pass schedule, load distribution correction calculation is performed as necessary, the thickness schedule is corrected, the calculation is completed, and all pass schedules are changed. decide.
• the shape of the rolled material, the crown, and the load (reduction) schedule are simultaneously calculated and determined for each pass in accordance with the shape control capability that is assumed to minimize the cross angle in the final stage.
• the stacking calculation with the optimum value, it is possible to determine the pass schedule that can satisfy the shape consistently for all passes and can roll at the maximum value of the rolling equipment capacity.
• the number of passes is automatically adjusted according to the above-described shape control ability, the ability to vary the number of passes in a reversible rolling mill can be sufficiently exhibited.
• the learning value was determined as follows.
• the negative of the second term is a characteristic of reverse rolling.
• the actual rolling load is such that the differential load of DS-WS is reversed between upper and lower sides during forward rotation and reverse rotation
• Mill elongation deviation occurs alternately in the forward and reverse directions as S R E F.
• the camber is generated in the direction in which the front part of the plate is bent toward the WS side during the normal rotation of the mill, and repeatedly bent toward the DS side during the reverse rotation. As the rolling pass progresses, this bending diverges in the direction of the maximum, and in the conventional rolling, the camber becomes larger as shown by the solid line in FIG.
• the S REF shown in Table 1 is predicted for each pass immediately before each pass as in this embodiment, and the amount is determined in advance as a roll gap unbalance value, so that the camber can be reduced. As shown by the dotted line in FIG.
• FIG. 5 is a block diagram showing a configuration of a control system for realizing the shape control of the present invention.
• Process computer 11 is a business computer 12 Before the start of rolling, the schedule of thickness, temperature, etc. for each pass is calculated in advance to determine the processing content of the entire finish rolling pass, and information on the actual results between passes is next calculated.
• Finishing path schedule calculation unit 11 A for performing learning calculation to feed-forward to the pass, and a plate is actually rolled for each pass according to the schedule obtained by the pass schedule calculation unit 11 A.
• it comprises a finish adaptive control calculation unit 11B that controls work roll bending in real time according to the detected value during rolling and the operator input value.
• FIG. 6 shows a side view of the rolling mill shown in FIG.
• the radiation thermometer 15 T (FIG. 5) detects the surface temperature of the material 7 to be rolled during rolling, and the a-line thickness gauge 15 H measures the thickness crown.
• the table roll 16 is located on the front and rear surfaces of the rolling mill and transports the material 7 to be rolled in synchronization with the rolling mill speed.
• the peripheral surface of the work roll 5 is supported by a backup roll 2, and the backup roll 2 is supported by a bearing 3.
• the work roll bending device (hereinafter referred to as WRB) 9 A adjusts the distance between the work roll bearing 4 and the bearing 3 to bend the work roll.
• the setting device 9B is a controller of the device 9A for setting the bending amount. Hydraulic screw-down device (hereinafter referred to as AG C) 8 A
• the screw down setting device 8B determines the screw down position. That is, the setting device 8B is a control device of the device 8A.
• the load cell 1 detects the rolling load while the material to be rolled 7 is rolled into a rolling mill.
• 18 is the bearing support frame of the cross device that sets the crossing angle (twice the cross angle) of the upper and lower sets of rotating shafts by setting the backup roll and the work roll as a set on the upper and lower sides, respectively. It is.
• the support frame 18 is connected to the screw 8 and is driven in the horizontal direction (left and right in FIG. 6) by its rotation.
• Pull back cylinder 19 is attached to support frame 18 It always applies a force in the evacuation direction, and suppresses displacement due to backlash when the support frame 18 is driven by the screw 8.
• the cross angle setting device 17 (Fig. 5) is a controller that biases this cross angle adjustment mechanism.
• Fig. 7 shows the contents of the previous path actual calculation and the learning calculation based on it, which are the premise of the next path setting calculation using the shape control of the present invention
• Fig. 8 shows the contents of the next path setting calculation .
• the finishing path schedule calculation processing unit 11A of the process computer 11 stores the sensor detection value of the path (hereinafter referred to as the previous path) held by the adaptive control calculation unit 11B.
• the actual values (rolling conditions and rolling results) are extracted (S1).
• the schedule calculation processing unit 11A uses a gauge meter formula based on the actual roll gap S act and the measured load cell load P act
• shape learning which is a feature of the present invention, is performed in S10 and S11.
• the shape of the material to be rolled is evaluated by wave height / wave pitch, and when expressed as steepness, the shape is generally sinusoidal
• ⁇ Expressed as the coefficient of influence of the crown ratio on the shape (hereinafter referred to as the shape change coefficient).
• Is known and the actual shape of the previous pass is calculated; Igage is calculated ( S10 ) 0
• the output shape of the actual result is flat
• next path setting calculation shows a calculation processing flow in which the learning result determined in FIG. 7 is actually reflected in the next path setting calculation.
• the target thickness and crown shape are set according to the schedule calculation set in advance (S12).
• the initial value of the next pass WRB load is set to a neutral point, and the shape and crown are set.
• the crown control should be reflected in the cross angle setting with a large control ability.
• the temperature of the next pass is estimated from the predicted time to the next pass (S13), and the load learning value P up to the previous pass is estimated based on the temperature. Estimate the predicted load Pesl of the next pass using fs ' ( S14 ).
• the target crown value of the next pass is corrected in consideration of the shape tolerance from the crown ratio of the previous pass (S15). That is,
• next path setting roll gap value is calculated, and the next path setting calculation ends.
• FIG. 9 shows an outline of a calculation process of the dynamic shape control process of the plant controller 13 shown in FIG. 5, and FIG. 10 shows a functional configuration for performing the calculation process.
• FIG. 9 and FIG. 10 the following actual values are grasped in real time during the c- roll byte, which describes a method for dynamically controlling the plate shape during the roll byte of the WRB.
• the finishing pass schedule calculation processing unit 11A sends the information to the adaptive control calculation unit 11B.
• the following data is transmitted.
• Adaptive control calculation unit 11 B calculates the actual calculation click la c down amount C real in Rorubai up by internal calculation in real time, sequentially recognizes the error Deruta_ ⁇ between the target value C ai ra. Tuning gain is applied to the AC (error), converted to WRB feedback correction amount ⁇ F WB , and interference with AGC (Automatic Gauge Control) is removed to set WRB Automatically make corrections to In other words, the calculation of the actual crown amount C real—the calculation of the error AC—the correction amount of the WRB ⁇ F WB— the correction of the set value of the WRB is repeated over a feedback buckle.
• AGC Automatic Gauge Control
• correction amount by the operator can be reflected outside the above-mentioned feedback loop, and the shape correction machine by the operator can be used. Function (“WRB correction amount” in Fig. 10).
• FIG. 11 shows execution timings of the above-mentioned various operations of the process computer 11.
• the correction correction of the operator in addition to the closed loop of the automatic control of the WRB, the correction correction of the operator can be reflected without disturbance, and the result of the inter-pass preset after the roll byte is obtained.
• the conventional method is an example in which the automatic control function of the WRB is provided, but the feedback of the actual value including the operator's correction is not reflected in the cross angle setting.
• the pass schedule of the rolled material was calculated under the following preconditions.
• Finishing temperature of the final pass 750 ° C (finish in the rear direction)
• the rolling schedule and the roll crossing angle schedule were determined simultaneously for each angular pass from the downstream pass toward the upstream pass.
• the calculation process for the last one pass (calculation start pass) is shown by numerical examples.
• the shape adjustment ability by the roll cross function is the same, but the conventional pass schedule does not allow the rolling load on the upstream side to reach the maximum equipment capacity, resulting in an increase in the number of passes.
• the schedule calculation is performed by searching for the allowable maximum rolling load under the cross constraint condition, so that the shape is maintained even when the cross angle at the final stage is minimized. The shortest number of passes can be achieved.
• the pass schedule of the rolled material was calculated under the following preconditions.
• the pass schedule of the rolled material was calculated under the following preconditions.
• the load actually applied to the rolling mill by the material is fed back to the plate thickness and the edge control, and the rolled plate thickness accuracy is improved.
• the members are greatly suppressed.
• the present invention enables rolling with a constant crown ratio over all passes, and improves the flatness shape.
• the shape of the rolled material, the crown and the load (reduction) schedule are determined simultaneously for each pass, and the shape is satisfied consistently for all passes. It is possible to determine the pass schedule that allows rolling at the maximum capacity.

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• Mechanical Engineering (AREA)
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Citations (3)

• 1993
  • 1993-11-10 GB GB9412120A patent/GB2278464B/en not_active Expired - Fee Related
  • 1993-11-10 WO PCT/JP1993/001644 patent/WO1994011129A1/ja active Application Filing
  • 1993-11-10 KR KR1019940702370A patent/KR0148612B1/ko not_active IP Right Cessation
• 1994
  • 1994-06-29 SE SE9402305A patent/SE505470C2/sv not_active IP Right Cessation

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