JP4213912B2 - Automatic operation method and apparatus for reverse rolling mill and its front and rear transfer table - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rolling mill that performs reverse rolling consisting of a plurality of passes, an automatic operation method of a front and rear conveyance table, and an apparatus thereof.
[0002]
[Prior art]
When a rolling mill that performs reverse rolling consisting of multiple passes, such as hot rolling of steel plates for thick plates, and its front and rear transfer table are operated automatically, conventionally, the rolling mill motor and the front and rear transfer table motor are synchronized to perform rolling. In general, control is performed so that the steel plate speed on the machine entry / exit side is always equal to the peripheral speed of the transfer table, that is, the steel plate does not slide on the table.
[0003]
In order to realize this control, it is necessary to make the acceleration / deceleration rates of the rolling mill motor and the conveyance table motor equal. However, due to economic restrictions, in general, the response of the conveyance table motor is higher than the response of the rolling mill motor. It is set low. That is, the number of motors of the front and rear transfer tables is several tens for one rolling mill motor, and in order for all of them to have the same responsiveness as the rolling mill motor, the equipment cost must be enormous. This is because there is not.
[0004]
Therefore, it has been a general method to determine the acceleration / deceleration rate of the rolling mill motor in accordance with the maximum acceleration / deceleration rate of the conveyance table having poor responsiveness within a range that does not significantly impair the production efficiency.
[0005]
[Problems to be solved by the invention]
FIG. 1 shows a conceptual diagram of the configuration of work flow and rolling time of each rolling pass for reverse rolling consisting of a plurality of passes. Here, the time between passes refers to the time during which the steel sheet passes through the rolling mill and is subjected to a rolling load, and the time between passes refers to the time during which the steel plate is separated from the rolling mill and is not subjected to a rolling load.
[0006]
As shown in FIG. 1, in the conventional method, in order to adapt the acceleration / deceleration rate of the rolling mill motor to the maximum acceleration / deceleration rate of the conveyance table with poor responsiveness, the time between passes is determined by the maximum acceleration / deceleration rate of the conveyance table. There was a wait. In this method, it cannot be said that the efficiency of the rolling process is maximized by making the best use of the capacity of the rolling mill.
[0007]
[Means for Solving the Problems]
The inventor inevitably occurs due to the difference between the steel plate speed of the rolling mill and the front and rear surface transfer table speed when the response of the front and rear surface transfer table motor is inferior to that of the rolling mill motor. The amount of slip of the steel sheet was measured for various rolling conditions and materials, and the amount of slip was found to be determined by the temperature of the steel sheet in addition to the size and speed of the steel sheet. A method of calculating the acceleration / deceleration rate and timing of the rolling mill and the front / rear conveyance table that minimizes the rolling time while maintaining stability was devised, and the present invention was achieved.
[0008]
  That is, the present invention
  (1) In the operation of a rolling mill that performs reverse rolling and its front and rear conveying tables, the steel sheet speed on the entry side or the exit side of the rolling mill, and the slip amount of the steel sheet due to the difference between the steel sheet speed and the conveying table speedIn order to maintain the required rolling stability, at least the biting idle running distance, biting acceleration length, and biting deceleration lengthSteel plate size, speed,Steel grade,temperatureEach optimum value is experimentally determined for each, and the biting idle running distance, biting acceleration length, and biting deceleration length obtained according to the size, speed, steel type, and temperature of the steel sheet to be rolled. Using the respective optimum values, the acceleration / deceleration rate and timing of the rolling mill and the front and rear surface transport table, that is, the time series change of the speed of the rolling mill and the front and rear surface transport table are temporarily determined and calculated from the speed of the rolling mill. While maintaining the required rolling stability while maintaining the required rolling stability, the amount of slip of the steel sheet obtained by integrating the difference between the steel plate speed and the front and rear surface conveying table speed over time,An automatic operation method for a rolling mill and a front / rear surface conveyance table, characterized by calculating an optimum acceleration / deceleration rate and timing of the rolling mill and the front / rear surface conveyance table that minimize the rolling time.
    However,
      Chewing idle distance: Distance from steel plate to metal stop until stopping
      Biting acceleration length: Necessary to reach the speed at which the steel plate bites into the rolling mill from a stopped state
      Distance
      Biting deceleration length: Distance required to stop from the biting speed of the rolled steel sheet
(2) An automatic operation device for a rolling mill and a front / rear surface transport table motor to which the rolling mill and the front / rear surface transport table automatic operation method described in (1) are applied, and a rolling mill for performing reverse rolling, and front / rear surfaces thereof A rolling mill speedometer for detecting a roll peripheral speed of a rolling mill for obtaining a speed of a rolled steel sheet, a transport table speedometer for detecting a roll peripheral speed of the front and rear surface transport table, Slip amount of steel plate from the peripheral speed of the rolling mill and the peripheral speed of the transfer tableIn order to maintain the required rolling stability, use the optimum values determined for each steel size, speed, steel type, and temperature for at least the idle running distance, the biting acceleration length, and the biting deceleration length. , Accelerating / decelerating rate and timing of the rolling mill and the front / rear surface transport table, that is, temporally determining the time series change of the speed of the rolling mill and the front / rear surface transport table, and calculating the steel plate speed and the front / rear speed calculated from the speed of the rolling mill While maintaining the stability of rolling where the slip amount of the steel sheet obtained by integrating the difference with the surface transfer table speed over time is required,An automatic operation device for a rolling mill and a front / rear surface conveyance table, comprising an arithmetic device for calculating an acceleration / deceleration rate and timing of the rolling mill and the front / rear surface conveyance table that minimize the rolling time.
[0009]
One embodiment of the automatic driving apparatus of the present invention is shown in FIG. Furthermore, the calculation flow of the acceleration / deceleration rate and timing of the rolling mill and the front / rear surface conveyance table is shown in FIG.
[0010]
The steel plate shown in FIG. 3 is rolled by a rolling mill from the left to the right in the figure, and after rolling is finished, it is placed on the right conveyance table, and then conveyed from the right to the left by the conveyance table and rolled again. The rolling mill and the conveyance table are each provided with a speedometer such as PLG. Each speedometer is connected to a computing device, and the computing device obtains the steel plate speed and position, and further obtains the speed difference between the steel plate speed and the conveyance table. Thereby, the slip amount of the steel sheet is calculated, and the acceleration / deceleration rate and timing of the rolling mill and the conveyance table are obtained from the calculated value. The result is instructed to each rolling mill motor or conveyance table motor.
Details of the calculation method of the acceleration / deceleration rate and timing of the rolling mill and the front and rear surface transfer table will be described below.
[0011]
  The acceleration start position (biting idle running distance) corresponding to the work on the entry side is set as follows.
  (1) Initial pathAcceptance position by work at the time of acceptance
                Code Work distance
                  0 None 5m
                  1 Temperature measurement 10m
                2 Descale 5 m
  (2) After the second pass, the target bite amount of the previous pass
         Determined by reflecting prediction error, position change by manual intervention, etc.
[0012]
  A target biting position (biting idle running distance) corresponding to the work on the exit side is determined as follows.
  (1) With delivery workNo-exit-side work-specific biting distanceSeparation
              Code Work distance
                0 None Free
                1 Temperature measurement 10m
                2 Descale 5m
              3 γ-ray measurement 12 m
  (2) No exit work (biting free running distance)
  When there is no restriction on the chewing idle running distance according to the delivery work, the target chewing idle running distance is determined with reference to the table having the following structure. From the viewpoint of the rolling operation stability and the surface properties of the steel sheet, the thickness and type of steel(However, temperature is included)The optimum value for each layer was experimentally determined in consideration of whether or not the steel plate and the conveying table roll were slid and the dynamic friction coefficient between the steel plate and the table roll when the steel plate was sliding.
  Table structure: [Thickness (15) x Steel grade (15)]
  By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28, <32,
                            <40, <60, <90,90 ≦
  By steel grade: (40K, 50K, etc.) ×By temperature layer:(<700, <750, <800, <850,850 ≦)
[0013]
  The mill speed (m / S) is determined by referring to a table having the following structure.
  Optimum value for each layer, considering the stability of rolling work and the surface properties of the steel sheet, considering whether or not the steel sheet and the conveying table roll slide depending on the plate thickness and steel type, and the dynamic friction coefficient of the steel sheet and table roll when the steel sheet slides Was experimentally determined.
(1) Steady: Determine the mill speed by referring to the table.
(2) Biting: Determine the biting acceleration rate by referring to the table.
              Biting speed = steady speed × (1-biting acceleration rate / 100)
(Three) Biting: Determine the biting deceleration rate by referring to the table.
              Biting speed = steady speed × (1−biting deceleration rate / 100)
      Table structure: [Thickness (15) x Steel grade (15)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By steel grade: (40K, 50K, etc.) ×By temperature layer:(<700, <750, <800, <850,850 ≦)
[0014]
  The material speed (m / S) during material biting is calculated as follows.
  However, hi: incoming side plate thickness, ho: outgoing side plate thickness, fs: advanced rate
  (1) Incoming 1) Steady Steady Mill Speed x (1 + fs) x ho / hi
              2) Biting Biting mill speed x (1 + fs) x ho / hi
              3) Chewing Chewing mill speed x (1 + fs) x ho / hi
  (2) Delivery side 1) Steady steady mill speed x (1 + fs)
              2) Biting Biting mill speed x (1 + fs)
              3) Chewing Chewing mill speed x (1 + fs)
[0015]
  The table speed (m / S) correction amount during material biting is determined as follows. Considering the stability of the rolling operation and the inertia of the steel plate, the optimum values for each layer thickness and width were experimentally determined. On the entry side, the table speed ≦ the steel plate speed, and on the exit side, the thin material in which the steel plate warping is a problem.
  (1) Input side Input side speed correction (-lag speed) is determined by referring to the table.
  (2) Delivery side Delivery side speed correction (+ lead speed [thin] or -lag speed [thick] is determined by referring to the table.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
      Input side table speed (steady state / engagement / extraction) = input side material speed × (1 + table speed correction / 100)
      Outlet table speed (steady state / engagement / extraction) = outside material speed × (1 + table speed correction / 100)
[0016]
  Table maximum acceleration / deceleration rate (m / S²) Is calculated. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
  (1) Acceleration The acceleration rate is determined by referring to the table.
  (2) Deceleration Decide the deceleration rate by referring to the table.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
[0017]
  In the following, the table acceleration rate calculated above is checked and corrected if necessary.
  (1) Min acceleration time (S) / Min acceleration distance (m)
        Min acceleration time = table biting speed / table maximum acceleration rate
        Min acceleration distance = table maximum acceleration rate x Min acceleration time²/ 2
                     = Table biting speed²/ Table maximum acceleration rate / 2
  (2) Biting idle distance <Min acceleration distance → Biting speed correction
        Correction table biting speed = (2 x biting idle running distance x table maximum acceleration rate)^1/2
Table acceleration rate = Table maximum acceleration rate
        Correction material biting speed = Correction table biting speed
        Correction mill biting speed = correction material biting speed / (1 + fs) × hi / ho
        Corrected mill bite acceleration = Mill steady state speed-Corrected mill bite speed
  (Three) Biting idle running distance ≥ Min acceleration distance → Acceleration rate determination
        Table acceleration rate = Table biting speed²/ Biting idle distance / 2
[0018]
The table acceleration start point (S) (input / output table acceleration start time interval) is calculated as follows.
Table acceleration start point = (Outgoing table speed-Incoming table speed) / Table acceleration rate
[0019]
  The mill acceleration rate (m / S²) Is calculated. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
      The mill acceleration rate is determined based on the table.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
[0020]
The mill acceleration start point (S) (entry table / mill acceleration start time interval) is calculated as follows.
Mill acceleration start point = entry table biting speed / table acceleration rate-mill biting speed / mill acceleration rate
[0021]
  From the following, the biting acceleration length (m) and the acceleration rate (m / S²) Is calculated.
  (1) Acceleration length
  The biting acceleration length is determined by referring to the table. Optimum value for each layer, considering the stability of rolling work and the surface properties of the steel sheet, considering whether or not the steel sheet and the conveying table roll slide depending on the plate thickness and steel type, and the dynamic friction coefficient of the steel sheet and table roll when the steel sheet slides Was experimentally determined.
      Table structure: [Thickness (15) x Steel grade (15)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By steel grade: (40K, 50K, other) ×By temperature layer:(<700, <750, <800, <850,850 ≦)
  (2) Acceleration rate
        Mill biting acceleration = Mill steady state speed-Mill biting speed
        Biting acceleration rate = Mill biting acceleration²/ Biting acceleration length / 2
  (Three) Acceleration rate check
  Determine the mill acceleration rate by referring to the table. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
      1) Biting acceleration rate> Mill acceleration rate → Biting acceleration length correction.
          Biting acceleration length = Mill biting acceleration²/ Mill acceleration rate / 2
      2) Bite acceleration rate ≤ Mill acceleration rate → No correction.
[0022]
  By the following, the biting deceleration length (m) and the deceleration rate (m / S²) Is calculated.
  (1) Deceleration length
  The biting deceleration length is determined by referring to the table. Optimum value for each layer, considering the stability of rolling work and the surface properties of the steel sheet, considering whether or not the steel sheet and the conveying table roll slide depending on the plate thickness and steel type, and the dynamic friction coefficient of the steel sheet and table roll when the steel sheet slides Was experimentally determined.
      Table structure: [Thickness (15) x Steel grade (15)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By steel grade: (40K, 50K, etc.) ×By temperature layer:(<700, <750, <800, <850,850 ≦)
  (2) Deceleration rate
      Mill feeding deceleration = Mill steady speed-Mill feeding speed
      Biting deceleration rate = Mill biting deceleration²/ Chewing deceleration length / 2
  (Three) Deceleration rate check
  Determine the mill deceleration rate by referring to the table. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                  <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
      1) Chewing deceleration rate> Mill deceleration rate → Chewing deceleration length correction.
            Biting deceleration length = Mill biting deceleration²/ Mill deceleration rate / 2
      2) Biting deceleration rate ≤ Mill deceleration rate → No correction.
[0023]
  The control amount in the next pass is calculated as follows.
  (1) No work on exit side → Calculate the following 1) to 6) in the next pass by the method of paragraphs [0013] to [0018] above.
      1) Next pass mill speed (1) Stationary paragraph [0013]-(1)
                            (2) Biting Above paragraph [0013]-(2)
      2) Advanced rate of next path prediction
      3) Next pass entry side material speed (1) Stationary paragraph [0014]-(1-1)
                            (2) Biting Above paragraph [0014]-(1-2)
      4) Next pass entry side table speed (1) Entry side above paragraph [0015]-(1)
                               (2) Outgoing paragraph [0015]-(2)
      5) Next pass table acceleration rate Paragraphs [0016] and [0017] above
      6) Next path table acceleration start point Paragraph [0018] above
  (2) With delivery work → Set all of 1) to 6) below to 0 in the next pass.
      1) Next pass mill speed (1) Steady state 0
                              (2) Biting 0
      2) Next path prediction advanced rate 0
      3) Next pass entry side material speed (1) Steady state 0
                              (2) Biting 0
      4) Next pass entry table speed 0
      5) Next pass table acceleration rate (1) Entry side 0
                              (2) Exit side 0
      6) Next path table acceleration start point 0
[0024]
  The allowable table deceleration start point (S) is determined by referring to the table as follows. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
[0025]
The Min deceleration time (S) and the Min deceleration distance (m) are calculated as follows.
Min deceleration time = table biting speed / table maximum deceleration rate
Min deceleration distance = Table maximum deceleration rate x Min deceleration time²/ 2
= Table biting speed²/ Table maximum deceleration rate / 2
[0026]
  The table deceleration start point and the deceleration rate are corrected as follows.
Case I: Target chewing idle running distance = 0 → When the delivery side table does not synchronize with the steel plate speed
        (Slip deceleration)
  (1) Expected material deceleration rate
  Predicted material deceleration rate is determined by referring to the table. Considering the stability of the rolling operation and the inertia of the cross section of the steel sheet, the optimum values for each thickness and width of the sheet were experimentally determined.
      Table structure: [Thickness (15) xBoard width (Five)]
      By thickness (thickness for each pass): <6, <8, <10, <12, <14, <16, <18, <20, <24, <28,
                                <32, <40, <60, <90,90 ≦
      By sheet width layer: <1600, <2400, <3200, <4000,4000 ≦
  (2) Expected material deceleration time
        Predicted deceleration time = Material biting speed / Predicted material deceleration rate
  (Three) Predicted material deceleration distance
        Predicted deceleration distance = Predicted material deceleration rate x Predicted material deceleration time²/ 2
                    = Material biting speed²/ Predicted material deceleration rate / 2
  (Four) Table deceleration rate (m / S²)
          Table deceleration rate = Maximum table deceleration rate
  (Five) Outside table deceleration start point (S) (Outside table deceleration start to metal-off time interval)
        Outlet table deceleration start point = Outlet table speed / Table maximum deceleration rate
  (6) Incoming table deceleration start point (S) (Incoming table deceleration start to metal off time interval)
        Entry table deceleration start point = entry table speed / table maximum deceleration rate-start point
                      Correction-(Predicted material deceleration time-Next path table acceleration start point)

  (7) Checking / correcting the deceleration table on the entry / exit side
        Clamp the input / output table deceleration start point at the allowable table deceleration start point.
        Input table deceleration start point> Allowable table deceleration start point
                → Input table deceleration start point = Allowable table deceleration start point
        Outlet table deceleration start point> Allowable table deceleration start point
                → Delivery table deceleration start point = Allowable table deceleration start point
[0027]
Case II: Aiming idle running distance ≠ 0 and Aiming idle running distance <Min Deceleration distance
  (1) Target table deceleration start point (S)
       Target table deceleration start point = Min deceleration time × (1− (Target biting idle running distance /
                        Min deceleration distance)^{1 / 2})
  (2) Delivery table deceleration start point (S)
        Target table deceleration start point> Allowable table deceleration start point
                → Delivery table deceleration start point = Allowable table deceleration start point
        Target table deceleration start point <Allowable table deceleration start point
               → Delivery side table deceleration start point = Target table deceleration start point
  (Three) Incoming table deceleration start point (S)
        Incoming table deceleration start point = Outgoing table deceleration start point
  (Four) Correction aiming bite running distance (m)
        Corrected biting idle running distance = table maximum acceleration rate
                × (Min deceleration time-delivery table deceleration start point)²/ 2
  (Five) Each speed correction
        Correction table biting speed = (2 x correction aim biting distance x table maximum reduction
        (Rate) 1/2
        Table deceleration rate = Maximum table deceleration rate
               Correction material biting speed = Correction table biting speed
               Corrected mill biting speed = corrected material biting speed / (1 + fs)
               Corrected mill bite deceleration = mill steady speed-corrected mill bite speed
[0028]
Case III: Target biting idle running distance ≠ 0 and target biting idle running distance ≥ Min deceleration distance
  (1) Outward table deceleration start point (S) = 0
  (2) Incoming table deceleration start point (S) = 0
  (Three) Table deceleration rate = Table biting speed²/ Chewing idle distance / 2
[0029]
The control timing of the table and the rolling mill is calculated as follows.
(1) Mill deceleration timing
Vmm [m / s]: Mill steady state speed
Vmo [m / s]: Mill biting speed
Vpm [m / s]: Stationary material steady speed
Vpo [m / s]: Outgoing material biting speed
αmo [m / s²]: Mill biting deceleration rate
αpo [m / s²]: Outlet material biting deceleration rate
Lpom [m]: Mill biting deceleration length
fs [-]: Advanced rate
Δtm [sec]: Mill biting deceleration time
Vpm = (1 + fs) Vmm
Vpo = (1 + fs) Vmo
αpo = (1 + fs) αmo
Δtm = (Vpm−Vpo) / αpo = (Vmm−Vmo) / αmo
Lpom = (Vpm + Vpo) Δtm / 2
= (1 + fs) (Vmm + Vmo) (Vmm-Vmo) / (2αmo)
= (1 + fs) (Vmm²-Vmo²) / (2αmo)
The mill deceleration start is performed at the timing when the target (predicted) rolling length (P / C setting) −delivery side rolling length record (PLC calculation) ≦ Lpom. Therefore, the distance Lpom required for deceleration corresponds to the hatched area shown in FIG.
Here, the delivery side roll length record L (see FIG. 3) is calculated by the following equation.
L = ∫ (1 + fs) Vm dt − (ΔLf / 100)
[0030]
(2) Table deceleration timing
Vmm [m / s]: Mill steady state speed
Vmo [m / s]: Mill biting speed
Vpm [m / s]: Stationary material steady speed
Vpo [m / s]: Outgoing material biting speed
αmo [m / s²]: Mill biting deceleration rate
αpo [m / s²]: Outlet material biting deceleration rate
Lpot [m]: Table biting speed reduction
fs [-]: Advanced rate
Δtt [sec]: Table biting deceleration time
Δtm [sec]: Mill biting deceleration time
Vpm = (1 + fs) Vmm
Vpo = (1 + fs) Vmo
αpo = (1 + fs) αmo
Δtm = (Vpm−Vpo) / αpo = (Vmm−Vmo) / αmo
Lpot = VpmΔtt− (Vpm−Vpo) Δtm / 2
= (1 + fs) VmmΔtt- (1 + fs) (Vmm-Vmo)²/ (2αmo)
The table deceleration start is performed at the timing when the target (predicted) rolling length (P / C setting) −delivery side rolling length result (PLC calculation) ≦ Lpot. Since the distance Lpot required for deceleration on the transfer table side is poor in response, as shown in FIG. 5, it corresponds to the area of the hatched portion in which a rectangle is further added to the trapezoid.
[0031]
【Example】
FIG. 4 is a conceptual diagram of the configuration of the work flow and rolling time of each rolling pass when the acceleration / deceleration rate and acceleration / deceleration start timing of the rolling mill and the conveyance table are determined for reverse rolling consisting of a plurality of passes based on the present invention. It is shown in FIG. By realizing the optimum acceleration / deceleration rate and acceleration / deceleration timing according to the material size and steel type, it is possible to maximize the efficiency of the rolling operation while maintaining sufficient stability of the rolling operation.
[0032]
Examples of controlling the speed and position of a rolling mill, a table, and a steel plate in the case where no material slip is generated for a material with particularly strict rolling stability on the rolling mill exit side are shown in FIGS.
[0033]
Examples of controlling the speed and position of the rolling mill, table, and steel plate when sliding the material on the rolling mill exit side, reducing table acceleration / deceleration responsiveness loss, and reducing the time between passes are shown in FIGS. Show.
[0034]
Roller and table when reducing table acceleration / deceleration loss by reducing table acceleration / deceleration loss by setting table speed <material speed during biting under conditions that do not cause material slip after biting on the rolling mill exit side. Examples of controlling the speed and position of the steel sheet are shown in FIGS.
[0035]
Example of controlling the speed and position of a rolling mill, table, and steel sheet when the sliding friction of the material is utilized to the maximum on the delivery side of the rolling mill, and the time between passes is minimized by stopping the steel sheet near the rolling mill. Shown in FIGS.
[0036]
【The invention's effect】
When a rolling mill that performs reverse rolling consisting of multiple passes, such as hot rolling of steel plates for thick plates, and its front and rear transfer table are operated automatically, conventionally, the rolling mill motor and the front and rear transfer table motor are synchronized to perform rolling. In general, control is performed so that the steel plate speed on the machine entry / exit side is always equal to the peripheral speed of the transfer table, that is, the steel plate does not slide on the table.
To achieve this control, it is necessary to equalize the acceleration / deceleration rates of the rolling mill motor and the transfer table motor. However, due to economic constraints, the response of the transfer table motor is generally lower than the response of the rolling mill motor. Is set. In other words, the number of motors of the front and rear transfer tables is several tens for one rolling mill motor, and the equipment cost must be enormous for all of them to have the same responsiveness as the rolling mill motor. It is. Therefore, it has been a general method to determine the acceleration / deceleration rate of the rolling mill motor in accordance with the maximum acceleration / deceleration rate determined from the specifications of the conveyance table with poor responsiveness within a range that does not significantly impede the production efficiency.
However, this method does not maximize the efficiency of the rolling process by making the best use of the capacity of the rolling mill.
[0037]
Therefore, the present inventor inevitably occurs due to the difference between the steel plate speed on the entry / exit side of the rolling mill and the front / rear transport table speed when the response of the front / rear transport table motor is inferior to that of the rolling mill motor. The amount of slip of the steel sheet to be measured was measured for various rolling conditions and materials, and the amount of slip was found to be determined by the temperature of the steel sheet in addition to the size and speed of the steel sheet. The method of calculating the acceleration / deceleration rate and timing of the rolling mill and the front and rear conveyance tables that minimize the rolling time while maintaining the stability of the present invention has been found.
As a result, the optimum acceleration / deceleration rate and acceleration / deceleration timing are realized in accordance with the size of the material and the steel type, and automatic rolling that maximizes the efficiency of the rolling operation is possible while sufficiently maintaining the stability of the rolling operation.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a configuration of work flow and rolling time of each rolling pass in reverse rolling.
FIG. 2 is a conceptual diagram showing an embodiment of the present invention.
FIG. 3 is a diagram showing a calculation flow of acceleration / deceleration rates and timings of a rolling mill and front and rear surface transfer tables.
FIG. 4 is a diagram showing a distance (Lpom) required for deceleration at the mill deceleration timing.
FIG. 5 is a diagram showing a distance (Lpot) required for deceleration at a conveyance table deceleration timing.
FIG. 6 is a conceptual diagram showing the configuration of the work flow and rolling time for each rolling pass when the acceleration / deceleration rate and the acceleration / deceleration start timing of the rolling mill and the conveyance table are determined.
FIG. 7 is a diagram showing an embodiment for controlling the speed and position of a rolling mill, a table, and a steel plate when no material slip occurs.
FIG. 8 is a diagram showing details of the normal rotation direction in the embodiment of the control method shown in FIG. 7;
9 is a diagram showing a relationship between time and a steel plate position in the embodiment of the control method shown in FIG.
FIG. 10 is a diagram showing an embodiment for controlling the speed of a rolling mill, a table, and a steel plate when a material is slid on the exit side of the rolling mill to reduce the acceleration / deceleration response loss of the table and shorten the pass time. .
FIG. 11 is a diagram showing details of the normal rotation direction in the embodiment of the control method shown in FIG. 10;
12 is a control method shown in FIG.Examples ofThe figure which shows the relationship between the time in steel, and a steel plate position.
[Fig. 13] Reduces the acceleration / deceleration responsiveness loss of the table with the table speed <material speed during biting under the condition that the material does not slip after biting on the rolling mill exit side, and shortens the pass time. The figure which shows the Example which controls the speed | rate of a rolling mill, a table, and a steel plate in the case of.
FIG. 14 is a diagram showing details of the normal rotation direction in the embodiment of the control method shown in FIG. 13;
FIG. 15 is a diagram showing a relationship between time and a steel plate position in the embodiment of the control method shown in FIG. 13;
FIG. 16 shows the speed and position of the rolling mill, table, and steel plate when the sliding friction of the material is utilized to the maximum on the delivery side of the rolling mill and the time between passes is minimized by stopping the steel plate in the vicinity of the rolling mill. The figure which shows the Example which controls.
FIG. 17 is a diagram showing details of the normal rotation direction in the embodiment of the control method shown in FIG. 16;
18 is a diagram showing a relationship between time and a steel plate position in the embodiment of the control method shown in FIG.

Claims (2)

In the operation of a rolling mill that performs reverse rolling and its front and rear conveyance tables, the steel plate speed on the entry side or the exit side of the rolling mill and the slip amount of the steel sheet due to the difference between the steel plate speed and the conveyance table speed are required. In order to maintain rolling stability, the optimum values for each of the steel sheet size, speed, steel type, and temperature are experimentally determined at least for the idle running distance, the biting acceleration length, and the biting deceleration length , Using the optimum values of the biting idle running distance, biting acceleration length, and biting deceleration length obtained according to the size, speed, steel type, and temperature of the steel sheet to be rolled, the rolling mill and the front and rear surface transfer table Acceleration / deceleration rate and timing, i.e., the time series change of the speed of the rolling mill and the front and rear conveyance table is temporarily determined, and the difference between the steel plate speed calculated from the speed of the rolling mill and the front and rear conveyance table speed is determined. On time Characterized in that the slip of the steel sheet which is obtained by integrating the while the range to keep the rolling stability required to calculate the optimal acceleration and deceleration rate and timing of the rolling mill and the front and rear surfaces conveying table for the rolling time the shortest Te An automatic operation method of the rolling mill and the front and rear transfer table.
However,
Chewing idle distance: Distance from steel plate to metal stop until stopping
Biting acceleration length: Necessary to reach the speed at which the steel plate bites into the rolling mill from a stopped state
Distance
Biting deceleration length: Distance required to stop from the biting speed of the rolled steel sheet An automatic operation device for a rolling mill and a front / rear surface transport table motor to which the rolling mill and the front / rear surface transport table automatic operation method according to claim 1 are applied, the rolling mill performing reverse rolling, and the front / rear surface transport table. A rolling mill speedometer for detecting the rolling peripheral speed of the rolling mill for obtaining the speed of the rolled steel sheet, a transport table speedometer for detecting the roll peripheral speed of the front and rear surface transporting table, and the rolling mill peripheral speed. The size and speed of the steel plate at least about the idle running distance, the biting acceleration length, and the biting deceleration length so as to maintain the rolling stability that requires the slip amount of the steel plate from the speed and the peripheral speed of the transfer table Using the optimum values obtained for each steel type and temperature, the acceleration / deceleration rate and timing of the rolling mill and the front / rear surface transport table, that is, the time series change of the speed of the rolling mill and the front / rear surface transport table are temporarily The amount of slip of the steel sheet obtained by integrating the difference between the steel plate speed calculated from the speed of the rolling mill and the front and rear surface transport table speed with respect to time is within a range that maintains the stability of the rolling. An automatic operation device for a rolling mill and a front / rear surface transport table, comprising: a rolling mill that minimizes the rolling time; and an arithmetic unit for calculating acceleration / deceleration rates and timings of the front / rear surface transport table.

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