JP2018134673A - Tandem rolling mill control device and tandem rolling mill control method - Google Patents

Abstract

An object of the present invention is to maintain a good load balance set up in advance even when a material to be rolled is being rolled.
A tandem rolling mill control device 100 sets up a set rolling load and a set rolling position prior to rolling a steel plate 163, and a set load ratio that calculates a set load ratio of each rolling stand 161. And a deviation between the actual load ratio calculation unit 904 that calculates the actual load ratio of each rolling stand 161 and the actual load ratio and the set load ratio in the downstream stand 902 during rolling of the steel plate 163. A reduction position control unit that controls the reduction position of the upstream stand 901 adjacent to the downstream stand 902.
[Selection] Figure 9

Description

  The present invention relates to a tandem rolling mill control device and a tandem rolling mill control method.

  In tandem rolling, it is important to roll the material to be rolled with a proper balance of the load of each rolling stand. Here, the value obtained by dividing the load of each rolling stand by the sum of the loads of all rolling stands is called the load ratio of each rolling stand, and the load ratio of each rolling stand from the entry-side rolling stand to the final exit-side rolling stand. The pattern consisting of is called load balance.

  In tandem rolling, various problems arise if this load balance is not good. For example, when the material to be rolled is caught in each rolling stand, the behavior becomes unstable, the shape of the material to be rolled is disturbed between the rolling stands and on the exit side of the final rolling stand, or the tension fluctuation between the rolling stands Becomes abnormally large. Therefore, in order to perform tandem rolling satisfactorily, it is important to perform rolling under an appropriate load balance.

  For example, Patent Literature 1 and Patent Literature 2 disclose examples of techniques for performing tandem rolling under an appropriate load balance. Patent Document 1 discloses a method for realizing a schedule in consideration of the balance of rolling load between adjacent rolling stands by a simple process by calculation (setup control) prior to rolling. Specifically, the load balance to be set up is determined by moving average the learning values between adjacent rolling stands against the problem that the variation in the learning values due to the rolling load prediction model of each rolling stand deteriorates the load balance. Smooth load balance can be achieved.

  Further, Patent Document 2 evaluates the rolling load balance of each rolling mill by calculation prior to rolling, and automatically detects this when an inappropriate load balance such as a heavy load on a specific rolling stand is detected. A technique is shown that is modified to obtain the ideal load balance setup value. Specifically, first, the total rolling load of each rolling stand is calculated, and the rolling load is summed with the ideal load distribution coefficient stratified by steel type, target plate thickness and target plate width in advance. Calculate the ideal rolling load of the stand. And while ensuring the delivery target thickness of the final stage rolling stand, correction calculation of the entry side thickness is performed for each rolling stand from the final rolling stand toward the upstream rolling stand so as to achieve the ideal rolling load. As a result, an ideal load balance is obtained.

Japanese Patent Laid-Open No. 2006-74008 Japanese Patent Laid-Open No. 9-192715

  According to the techniques disclosed in Patent Document 1 and Patent Document 2, the rolling load of each rolling stand set up prior to rolling of the material to be rolled can surely have a good load balance. However, when the material to be rolled is actually rolled, sufficient consideration is not always given to maintaining the set load balance.

  In fact, the material to be rolled during rolling changes in temperature and hardness in the longitudinal direction. Further, as a result of the setup control, a plate thickness deviation more than expected may occur. In such a case, since automatic thickness control (AGC) operates in each rolling stand during rolling, the rolling load at each rolling stand during rolling changes. That is, the load balance between the rolling stands changes.

  For example, when the actual plate thickness measured on the exit side of the final stage rolling stand is different from the target plate thickness, plate thickness control called monitor AGC is performed in order to make the actual plate thickness coincide with the target plate thickness. In this monitor AGC, the reduction position is controlled in the closing direction when the thickness deviation is thick, and is controlled in the opening direction when the thickness deviation is thin. In the monitor AGC, from the consideration of responsiveness, most of the operation amount is usually distributed to the latter stage rolling stand (especially the last stage rolling stand). For this reason, when there is a large thickness deviation at the tip of the material to be rolled, only the load of the subsequent rolling stand changes greatly, and the load of the preceding rolling stand hardly changes, and the overall load balance is impaired. Become.

  In addition, in hot rolling, the temperature of the rough material of the material to be rolled when entering the tandem rolling mill gradually decreases. Therefore, the material to be rolled (coarse material) rolled at the upstream rolling stand becomes gradually harder during rolling. At this time, in order to keep the exit side plate thickness of each rolling stand constant, a plate thickness control called BISRA-AGC works, so the load on the upstream rolling stand also gradually increases. On the other hand, the temperature of the material to be rolled on the delivery side of the tandem rolling mill is maintained at a substantially constant temperature by appropriately increasing or decreasing the cooling water between the rolling stands. For this reason, the hardness of the material to be rolled at the downstream rolling stand hardly changes, and the load does not increase. As a result, the set-up load balance changes.

  As described above, even if a load considering the load balance is set up in each rolling stand, the load balance changes due to various factors during rolling of the material to be rolled. Like the techniques disclosed in Patent Document 1 and Patent Document 2, in the prior art, sufficient consideration is not given to the change in load balance during rolling of the material to be rolled. Therefore, due to the influence of the load balance disturbed during rolling, the shape and width of the material to be rolled between the rolling stands and on the exit side of the rolling stand at the final stage are disturbed, the quality is deteriorated, and the stability of rolling is impaired. There was something to do.

  An object of the present invention is to provide a tandem rolling mill control device and a tandem rolling mill control method capable of maintaining a good load balance set up in advance even while a material to be rolled is being rolled.

The tandem rolling mill control device according to the present invention is a tandem rolling mill control device that controls a tandem rolling mill that continuously rolls a material to be rolled by a plurality of rolling stands, and prior to rolling the material to be rolled, For each of the plurality of rolling stands, a set-up control unit that sets a set rolling load and a setting reduction position for realizing a target plate thickness of the material to be rolled, and at least one rolling selected from the plurality of rolling stands About the 1st rolling stand which is a stand, based on the set rolling load set to the 1st rolling stand and the set rolling load set to each of the plurality of rolling stands, the 1st rolling stand A set load ratio calculation unit for calculating a set load ratio for the above-mentioned, obtained from the first rolling stand during rolling of the material to be rolled. An actual load ratio calculating unit for calculating an actual load ratio for the first rolling stand based on the actual rolling load obtained from each of the plurality of rolling stands, and during rolling of the material to be rolled In addition, the reduction for controlling the reduction position of the second rolling stand located upstream of the first rolling stand so that the deviation of the actual load ratio in the first rolling stand from the set load ratio becomes small. A position control unit;
It is characterized by providing.

  ADVANTAGE OF THE INVENTION According to this invention, the tandem rolling mill control apparatus and tandem rolling mill control method which can maintain the favorable load balance set up previously even while rolling a to-be-rolled material are provided.

The figure which showed the example of the structure of the tandem rolling mill control apparatus which concerns on the 1st Embodiment of this invention, and its control object. The figure which showed the example of the processing flow of the setup control process performed by the setup control part. The figure which showed the example of the structure of the draft schedule table memorize | stored in a draft schedule memory | storage part. The figure which showed the example of the structure of the speed pattern table memorize | stored in a speed pattern memory | storage part. The figure which showed the example of the processing flow of the setting load ratio calculation process performed by the setting load ratio calculation part. The figure which showed the example of the processing flow of the influence coefficient calculation process performed by the influence coefficient calculation part. The figure which showed the example of the processing flow of the load balance maintenance process performed by the load balance maintenance part. The figure which showed the example of the processing flow of the reduction position control process performed by the reduction position control part. The figure which showed typically the example of the process structure in a load balance maintenance part. The figure which showed the example of the structure of the tandem rolling mill control apparatus which concerns on the 2nd Embodiment of this invention centering on the process structure in a load balance maintenance part. The figure which showed the example of the structure of the control parameter table memorize | stored in the control parameter memory | storage part which concerns on the 2nd Embodiment of this invention. The figure which showed the example of the structure of the control parameter search auxiliary table memorize | stored in the control parameter search auxiliary storage part which concerns on the 2nd Embodiment of this invention. The figure which showed the example of the processing flow of the control parameter extraction process which the control parameter extraction part which concerns on the 2nd Embodiment of this invention performs. The figure which showed the example of the structure of the control parameter search auxiliary table memorize | stored in the control parameter search auxiliary storage part which concerns on the modification of the 2nd Embodiment of this invention. The figure which showed the example of the processing flow of the control parameter extraction process which a control parameter extraction part performs in the modification of the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to a common component and the overlapping description is abbreviate | omitted.

<< First Embodiment >>
FIG. 1 is a diagram showing an example of the configuration of a tandem rolling mill control device 100 and its control object 150 according to the first embodiment of the present invention. As shown in FIG. 1, the tandem rolling mill control device 100 according to the first embodiment receives various signals from the control target 150 and outputs various control signals to the control target 150 accordingly.

In the present embodiment, the control target 150 is a hot tandem rolling mill provided with a finishing mill 160. The finishing mill 160 is constituted by a plurality of rolling stands 161, and in the present embodiment, seven rolling stands 161 (F _{1 to} F ₇ ) are continuously arranged. This configuration is a general configuration of a hot tandem rolling mill.

  In FIG. 1, a steel plate 163 that is a material to be rolled moves from left to right, and a thin steel plate 165 is rolled by rolling a rough material 165 having a thickness of about 30 to 40 mm that has been rolled by a roughing mill that is the previous step. 163 is produced. The coarse material 165 may be called by a name such as a coarse bar, an incoming bar, or a transfer bar.

The coarse material 165 is rolled at each rolling stand 161 of the finishing mill 160 and is processed to be thin. The steel plate 163 has a thickness of about 1.6 mm to 15 mm on the exit side of the final rolling stand 161 (F ₇ ). As paid out. In finishing mill 160, it is work roll 162 of each rolling stand 161 that directly rolls coarse material 165 and steel plate 163. In this specification, the roll speed means the peripheral speed of the work roll 162.

Further, in the present embodiment, as a detector for recognizing the state of the steel sheet 163 is rolled, the plate thickness of the steel sheet 163 to the outlet side of the final stage of the rolling stand 161 of the finishing mills 160 (F _7), the plate width, A multi-gauge 164 for measuring temperature and the like is provided. In addition, although illustration is abbreviate | omitted here, the crop which measures the image of the shape meter which measures the flatness of the steel plate 163, the surface wrinkle meter which detects a surface flaw, and the rough material 165 actually. Various detectors such as a profile meter are provided in various places as appropriate.

<Overall Configuration of Tandem Rolling Mill Control Device 100>
Next, the configuration of the tandem rolling mill control device 100 will be described with reference to FIG. The tandem rolling mill control apparatus 100 includes processing function blocks such as a setup control unit 101, a set load ratio calculation unit 104, an influence coefficient calculation unit 105, a reduction position control unit 106, a rolling performance collection unit 107, and a speed control unit 108. Composed. The tandem rolling mill control device 100 includes storage function blocks such as a draft schedule storage unit 102 and a speed pattern storage unit 103.

Prior to rolling the steel plate 163 (coarse material 165), the setup control unit 101 calculates a rolling load, a reduction position, and a roll speed to be output to each rolling stand 161 (F _{1 to} F ₇ ), and sets and rolls them. Set as load, set reduction position, and set roll speed. That is, the setup control unit 101 receives the rolling specifications (steel type, target plate thickness, target plate width, etc.) of the steel plate 163 transmitted from the host computer 50. Then, according to the received rolling specifications, the draft schedule storage unit 102 and the speed pattern storage unit 103 are referred to, and the rolling load and reduction of each rolling stand 161 (F _{1 to} F ₇ ) for realizing the target plate thickness. Calculate the position and roll speed. And the rolling load, reduction position, and roll speed obtained by the calculation are set (set up) as the set rolling load, the set reduction position, and the set roll speed.

The rolling record collecting unit 107 is the actual value of the rolling state transmitted from the control object 150 (such as the detection value of the multigauge 164), or the actual value of the control command actually output to the control object 150 by the tandem rolling mill control device 100. Collect etc. The reduction position control unit 106 uses the setup control unit 101 so that the exit side plate thickness of the rolling stand 161 (F ₇ ) at the final stage becomes the target plate thickness based on various performance values collected by the rolling performance collection unit 107. The set rolling reduction position of the set rolling stand 161 (F _{1 to} F ₇ ) is corrected. Further, the speed control unit 108 corrects the set roll speed of each rolling stand 161 (F _{1 to} F ₇ ) set by the setup control unit 101 based on various performance values collected by the rolling performance collection unit 107. .

  By the way, the rolling position control unit 106 automatically corrects the set rolling position of each rolling stand 161 set up in advance by the setup control unit 101 according to the rolling state during rolling of the steel plate 163 (hereinafter, referred to as “rolling position control”). (Also called AGC) function. In the present embodiment, the AGC function is realized by, for example, the BISRA AGC 111, the gauge meter AGC 112, and the monitor AGC 113.

In addition, these AGC techniques are well-known techniques, for example, BISRA AGC111 suppresses the dispersion | variation in the outgoing side plate | board thickness of each rolling stand 161 along a steel plate longitudinal direction. Further, the gauge meter AGC 112 corrects the rolling position of each rolling stand 161 so that the estimated delivery side plate thickness of each rolling stand 161 matches the desired plate thickness. The monitor AGC 113 corrects the reduction position of the subsequent rolling stand (mainly the final rolling stand 161 (F ₇ )) so that the actual plate thickness of the steel plate 163 detected by the multi-gauge 164 matches the target plate thickness. To do.

  In addition to this, various forms of AGC such as a gauge meter AGC to which a Smith compensator is added are known as AGC. In the reduction position control unit 106, the above AGC can be used in appropriate combination.

  The rolling position control unit 106 includes a load balance maintaining unit 110 for maintaining the load ratio of each rolling stand 161 at a set load ratio set in advance by the setup control unit 101 during rolling of the steel plate 163. The reduction position control unit 106 adds the outputs of the BISRA AGC 111, gauge meter AGC 112, monitor AGC 113, and load balance maintenance unit 110 to the reduction position of each rolling stand 161 set by the setup control unit 101. Then, the reduction position obtained by this addition is output to the finishing mill 160 as a control command for the reduction position to each rolling stand 161.

  The tandem rolling mill control device 100 having the above configuration can be realized by a general computer including at least an arithmetic processing device and a storage device. In that case, the function of each part which comprises the tandem rolling mill control apparatus 100 is implement | achieved when the arithmetic unit of a computer runs the program memorize | stored in the memory | storage device. However, the draft schedule storage unit 102 and the speed pattern storage unit 103 are configured as information stored on the storage device. The storage device stores various information used when executing the program.

  Next, functions and operations of each part constituting the tandem rolling mill control device 100 will be described in detail.

<Setup control unit 101>
As described above, the setup control unit 101 transmits the rolling specifications (steel type, target plate thickness, target plate width, etc.) of the steel plate 163 to be rolled next, which is transmitted from the host computer 50 prior to the rolling of the steel plate 163. Receive. And according to the received rolling specification, control commands, such as a setting rolling load, a setting reduction position, and a setting roll speed, for each rolling stand 161 (F _{1 to} F ₇ ) are calculated. Control commands such as the set rolling load, the set reduction position, and the set roll speed are corrected as appropriate and output to the finishing mill 160 of the control target 150.

By the way, when the steel plate 163 is rolled by the finishing mill 160, the front end portion of the steel plate 163 is rolled according to the control command output from the setup control unit 101. Therefore, in order to obtain a desired plate thickness (target plate thickness) from the tip of the rolled steel plate 163, the set rolling load and the set roll-down position of the work roll 162 in each rolling stand 161 (F _{1 to} F ₇ ) are: Must be determined appropriately. Further, in order to stabilize the behavior when the steel plate 163 is caught in the downstream rolling stand 161, the set roll speed of each rolling stand 161 (F _{1 to} F ₇ ) is set to the mass flow (the thickness of the steel plate 163). The product of the plate speed must be balanced without any disturbance. In addition, about the method of calculating these appropriate setting reduction positions and setting roll speeds, including the calculation formula, it mentions later.

Furthermore, during the rolling of the steel plate 163, the rolling position control unit 106 and the speed control unit 108 are based on the actual values such as the plate thickness of the steel plate 163 detected by the multigauge 164, and the rolling stands 161 (F _{1 to} F ₇ ) Correct the reduction position and roll speed output to step ₇ ). Under the influence of this correction, the rolling load at each rolling stand 161 (F _{1 to} F ₇ ) may change, and the load balance between the rolling stands 161 (F _{1 to} F ₇ ) may be lost. Therefore, in this embodiment, the load balance maintenance unit 110 even after this correction has been made, based on the set rolling load of each rolling stand 161 which is set by the setup controller 101 _(F 1 ~F ₇₎ Control to maintain the load balance.

  FIG. 2 is a diagram illustrating an example of a process flow of the setup control process executed by the setup control unit 101. As shown in FIG. 2, the setup control unit 101 first acquires the rolling specifications (steel type, target plate thickness, target plate width) of the steel plate 163 to be rolled next, which is transmitted from the host computer 50 (step S20). . Next, the setup control unit 101 refers to the draft schedule storage unit 102 and acquires a draft schedule corresponding to the rolling specification (step S21). Here, the draft schedule is information representing how much the thickness of the coarse material 165 or the steel plate 163 is reduced in each rolling stand 161.

FIG. 3 is a diagram showing an example of the configuration of the draft schedule table 102T stored in the draft schedule storage unit 102. In the draft schedule table 102T of FIG. 3, the information in each item column of “steel type”, “target plate thickness”, and “target plate width” is information for stratifying the rolling specifications of the steel plate 163 to be rolled. Moreover, the information in the item column of “F ₁ ” to “F ₇ ” indicates the rolling reduction (percentage) at which the steel plate 163 is rolled in each rolling stand 161 (F _{1 to} F ₇ ) for each layer of the rolling specification. Information. The rolling reduction means the ratio of the difference in plate thickness between the inlet side and the outlet side with respect to the inlet side plate thickness.

  For example, a draft schedule in the case of rolling a rough material 165 having a steel grade of SS400 and a plate thickness of 35 mm to a steel plate 163 having a target plate thickness of 2.5 mm and a target plate width of 900 mm is the draft schedule table 102T in FIG. Corresponds to the data in the first row. That is, the steel plate 163 having a target plate thickness of 2.5 mm and a target plate width of 900 mm corresponds to a rolling specification in which the steel type is SS400, the target plate thickness is 2.0 to 3.0 mm, and the target plate width is 1000 mm or less.

Furthermore, according to the data in the first row of the draft schedule table 102T, in the rolling stand 161 (F ₁ ), the coarse material 165 having a thickness of 35 mm is rolled by 14 mm corresponding to 40% of the thickness. The side plate thickness is 21 mm. In addition, in the rolling stand 161 (F ₂ ), the steel plate 163 having the inlet side plate thickness of 21 mm is rolled to a thickness corresponding to 35% of the plate thickness, resulting in an outlet plate thickness of 13.65 mm.

Thereafter, rolling is performed in the same manner. Then, a steel plate 163 having a target plate thickness of 2.5 mm is paid out from the final rolling stand 161 (F ₇ ). In addition, when the deviation from the target plate thickness of 2.5 mm occurs in the exit side plate thickness of the final stage rolling stand 161 (F ₇ ) obtained as described above, the other rolling stands 161 according to the deviation. the rolling reduction of _(F 1 ~F ₆₎ may be appropriately adjusted.

  Returning to FIG. 2, the description of the setup control process will be continued. Next, the setup control unit 101 refers to the speed pattern storage unit 103 and acquires the speed pattern of the steel plate 163 corresponding to the rolling specifications (steel type, target plate thickness, target plate width) transmitted from the host computer 50. (Step S22).

  FIG. 4 is a diagram showing an example of the configuration of the speed pattern table 103T stored in the speed pattern storage unit 103. As shown in FIG. 4, the data in each row of the speed pattern table 103T is a rolling speed (also referred to as a plate speed) set in advance according to the rolling specifications (steel type, target plate thickness, target plate width) of the steel plate 163 to be rolled. ) Or the acceleration information.

Here, the initial speed is the steel plate speed when the tip of the steel plate 163 is paid out from the final rolling stand 161 (F ₇ ). Further, the first acceleration is an acceleration when the steel plate speed gradually increases from the initial speed, and the second acceleration is a steady state after the steel plate 163 is bitten by a downcoiler (not shown) which is a subsequent facility. Acceleration to reach speed. The deceleration is a negative acceleration when the steel plate 163 is decelerated from the steady speed to the final speed so that the steel plate 163 can stably pass through the rolling stands 161 (F _{1 to} F ₇ ). The final speed is the steel sheet speed when the tail end of the steel sheet 163 is paid out from the final rolling stand 161 (F ₇ ).

  According to FIG. 4, when the steel type of the steel plate 163 to be rolled is SS400, the plate thickness is 1.2 to 1.4 mm, and the plate width is 1000 mm or less, the initial speed is 650 mpm, the steady speed is 1100 mpm, and the final speed is 700 mpm. It becomes. Then, 2 mpm / s is set as the first acceleration, 12 mpm / s is set as the second acceleration, and 6 mpm / s is set as the deceleration.

Returning to FIG. 2 again, the description of the setup control process will be continued. The setup control unit 101 estimates the rolling temperature of the steel plate 163 in each rolling stand 161 (F _{1 to} F ₇ ) (step S23). That is, the set-up control unit 101 has a temperature obtained from thermometers (not shown) installed at various locations of the controlled object 150, heat radiation from the steel plate 163, processing heat generation, and a roll taken through the work roll 162. The temperature of the steel plate 163 during rolling is estimated in consideration of contact heat transfer and the like.

  Many methods of temperature estimation in this case are introduced in various thermodynamic literatures. In particular, the temperature change during rolling is described in detail in Chapter 6 (Temperature change in rolling) of "Theory and practice of plate rolling (Japan Iron and Steel Institute)", for example.

  Next, the setup control unit 101 calculates a deformation resistance that is a value corresponding to the hardness of the steel plate 163 rolled at each rolling stand 161 (step S24). The method for obtaining the deformation resistance is also described in various documents, and is described in detail in Chapter 7 (deformation resistance) of "Theory and Practice of Sheet Rolling (Japan Iron and Steel Institute)".

As a typical calculation formula of the deformation resistance kf, for example, there is the following formula (1) calculated using the steel plate temperature T at the time of rolling (refer to formula 7.54 in “Theory and practice of plate rolling”). .

kf = Kε ⁿ (dε / dt) ^m exp (A / T) (1)
Where ε: strain
(dε / dt): Strain rate
K, n, m, A: Constants determined by steel type

Next, the setup control unit 101 calculates a roll speed Vr _i of the rolling stand 161 _(F 1 ~F _{7) (step} S25). Since the speed pattern data acquired in step S22 is the exit side plate speed (rolling speed) of the rolling stand 161 (F ₇ ) at the final stage, each rolling stand 161 (F _{1 to} F ₇ is used by using this exit side plate speed. the roll speed Vr _i) of is calculated by the following procedure 1 and procedure 2.

(Procedure 1) The setup control unit 101 calculates the exit side plate speed Vs _i (i = ₁ to ₇ ) of each rolling stand 161 (F _{1 to} F ₇ ) using the following equation (2).

Vs _i = Vs ₇ × h _i / h ₇ (2)
Here, Vs _i : the exit side plate speed of the rolling stand (F _i )
h _i : Outboard thickness of the rolling stand (F _i )
h ₇ : Outboard thickness of the rolling stand (F ₇ ) (final stage rolling stand)

(Step 2) setup controller 101, using the side plate speed Vs _i and advanced rate _{f i} out of the rolling stand 161 _(F 1 to F _7), according to the following equation (3), the rolling stand 161 ( The roll speed Vr _i (i = ₁ to ₇ ) of F _{1 to} F 7) is calculated.

Vr _i = Vs _i / f _i (3)
Here, Vr _i : Roll speed of the rolling stand (F _i )
f _i : Advanced rate of rolling stand (F _i )

Here, the forward slip f, a value corresponding to the ratio of the side plate speed Vs _i out of the steel sheet 163 is rolled by the peripheral speed and the work rolls 162 of the work roll 162, for example, a function such as equation (4) It is known that The details are shown in “Theory and Practice of Sheet Rolling” (edited by the Japan Iron and Steel Institute).

f = F (H, h, R ′, Kp, tb, tf) (4)
Where H: Thickness on the entry side
h: Outboard thickness
R ′: flat roll diameter,
Kp: Deformation resistance
tb: entry side tension
tf: exit side tension (parameter symbols H, h, R ′, Kp, tb, tf have the same meanings in the following formulas (5) and below. Also, formulas (4), (5), (6) ), The symbol i identifying the rolling stand (F _i ) is omitted.)

Therefore, the setup controller 101, and thus obtaining the roll speed Vr _i of each rolling stand 161 on which to calculate the forward slip _{f i} for each rolling stand 161.

Next, the setup control unit 101 calculates a set rolling load P _{set_i} of each rolling stand 161 (F _{1 to} F ₇ ) (step S26). The details of the calculation formula of the rolling load P are shown in “Theory and Practice of Plate Rolling” (edited by the Japan Iron and Steel Institute), and are expressed, for example, by the following formula (5).

P = G (w, Kp, Qp, tf, tb, R ′, H, h, μ) (5)
Where w: board width
Kp: Deformation resistance
Qp: Rolling force function
μ: Friction coefficient

Finally, the setup control unit 101, the pressing position of the work roll 162 (roll gap) _{S i} of the rolling stand 161 _(F 1 ~F ₇₎ is calculated and a set pressing position S _{Set_i} this (step S27) . The reduction position S _i can be basically calculated using the following equation (6). In practice, however, various correction terms such as a bender pressure for controlling the deflection of the roll are often added in order to increase the accuracy of the calculation, but are omitted here.

S = h−P / K (6)
Where S: Rolling position
P: Rolling load
K: Mill spring constant

Setup controller 101, above manner set pressing position S _{Set_i} and roll speed Vr _i work roll 162 of the rolling stand 161 _(F 1 ~F ₇₎ which is calculated, then the control to the steel sheet 163 is rolled Output as a command.

<Set load ratio calculation unit 104>
FIG. 5 is a diagram illustrating an example of a processing flow of a set load ratio calculation process executed by the set load ratio calculation unit 104. As shown in FIG. 5, the set load ratio calculation unit 104 calculates the sum P _{total_set} of the set rolling loads P _{set_i} for each rolling stand 161 (F _{1 to} F ₇ ) by the following equation (7) (step) S51).

_{P total_set = P set_1 + P set_2} + P set_3 + P set_4 + P set_5 + P set_6 + P set_7 (7)
Here, P _{set_i} : set rolling load of the rolling stand (F _i )

Subsequently, the set load ratio calculation unit 104 calculates the set load ratio Pr _{set_i} of the rolling stand 161 (F _i ) by the following equation (8) (step S52).

Pr _{set_i} = P _{set_i} / P _{total_set} (8)

Next, the set load ratio calculation unit 104 determines whether or not the calculation of the set load ratio Pr _{set_i} has been completed for all of the rolling stands (F _{1 to} F ₇ ) (step S53). (No in step S53), the process of step S52 is executed again. _Further , when the calculation of the set load ratio Pr _{set_i} is completed for all of the rolling stands (F _{1 to} F ₇ ) (Yes in step S53), the set load ratio calculation process is ended.

The set load ratio Pr _{set_i} calculated as described above is calculated based on an appropriate set rolling load of each rolling stand (F _{1 to} F ₇ ) set by the setup control unit 101. Therefore, it can be said that the set load ratio Pr _{set_i} represents information indicating a preferable load balance between the rolling stands (F _{1 to} F ₇ ).

<Influence coefficient calculation unit 105>
FIG. 6 is a diagram illustrating an example of a processing flow of an influence coefficient calculation process executed by the influence coefficient calculation unit 105. As shown in FIG. 6, the set load ratio calculation unit 104 calculates the influence coefficient φ _{coef_i} of the rolling stand 161 (F _i ) by the following equation (9) (step S61).

φ _coef — _i = ( _{∂S i} / ∂P _i ) (∂P _i / ∂h _i ) (∂H _{i + 1} / ∂P _{i + 1} ) (9)
Here, S _i : Rolling position of rolling stand (F _i )
P _i : Rolling load of the rolling stand (F _i )
h _i : Entrance side plate thickness of the rolling stand (F _i )
H _i : Outboard thickness of the rolling stand (F _i ) (where H _{i + 1} = h _i )

Incidentally, the influence coefficient phi _{Coef_i,} pressing position correction amount of the rolling stands 161 _{(F i)} for a unit amount correction load ratio of the downstream rolling stand 161 (F _{i + 1)} of the rolling stand 161 _{(F i)} It can be said. Therefore, the influence coefficient φ _{coef_i} can be calculated for the rolling stand (F _{1 to} F ₆ ), but is not defined for the rolling stand (F ₇ ) in the final stage.

Further, in the formula _{(9) (∂S i / ∂P} i) can be calculated by partially differentiating Equation (6) in _{P i.} Similarly, (∂P _i / ∂h _i ) and (∂H _{i + 1} / ∂P _{i + 1} ) can be calculated by partial differentiation of equation (5) with h _i .

Next, the set load ratio calculation unit 104 determines whether or not the calculation of the influence coefficient φ _{coef_i} has been completed for all of the rolling stands (F _{1 to} F ₆ ) (step S62). (No in step S62), the process of step S61 is executed again. When the calculation of the influence coefficient φ _{coef_i} is completed for all of the rolling stands (F _{1 to} F ₆ ) (Yes in step S62), the influence coefficient calculation process is ended.

<Rolling position control unit 106>
As described above, the processes of the setup control unit 101, the set load ratio calculation unit 104, and the influence coefficient calculation unit 105 described so far are performed before the steel plate 163 is rolled by the finishing mill 160. And when the front-end | tip part of the steel plate 163 is bitten by each rolling stand 161, the reduction position control part 106 controls the reduction position of the work roll 162 according to the setting reduction position output from the setup control part 101. . Similarly, the speed control unit 108 controls the roll speed of the work roll 162 according to the set roll speed output from the setup control unit 101 when the tip of the steel plate 163 is bitten into each rolling stand 161. .

  On the other hand, when the rolling of the steel plate 163 is started and the acquisition of the rolling record by the rolling record collecting unit 107 is started, the reduction position of each rolling stand 161 is corrected by the load balance maintaining unit 110 and the three AGCs 111 to 113. . Therefore, the reduction position control unit 106 executes a process of correcting the reduction position at a constant cycle (for example, at intervals of 1 second), and corrects the set reduction position obtained by the setup control unit 101 each time. Then, the reduction position obtained by the correction is output to finishing mill 160.

  In the following, among the processes of the reduction position control unit 106, first, the processing of the load balance maintaining unit 110 will be described, and then the processing of the entire reduction position control unit 106 will be described.

FIG. 7 is a diagram illustrating an example of a processing flow of the load balance maintenance process executed by the load balance maintenance unit 110. In the load balance maintenance process, the set reduction position is corrected only for the rolling stand 161 (F _{1 to} F ₆ ) in which another rolling stand 161 exists downstream. Therefore, the process of FIG. 7 is performed for i = 1 to 6.

As shown in FIG. 7, the load balance maintenance unit 110 first calculated in set load ratio calculating unit 104, downstream of the set load of the rolling stands 161 (F _{i + 1)} of the rolling stands 161 _{(F i)} The ratio Pr _{set_i + 1} is acquired (step S71). Next, the load balance maintenance unit 110 acquires the influence coefficient φ _{coef_i} of the rolling stand 161 (F _i ) calculated by the influence coefficient calculation unit 105 (step S72).

Next, the load balance maintenance unit 110, via the rolling track record collection unit 107, acquires the respective results rolling load Pr _{Act_i} of the rolling stand _{161 (F 1 ~F 7) (} i = 1~7) ( step S73). Then, according to the following equation (10), calculates the actual load ratio _Pr act_i _{+ 1} downstream of the rolling stand 161 of the rolling stands _{161 (F i) (F i} + 1) ( step S74).

Pr _{act_i + 1} = P _{act_i + 1} / P _{total_act} (10)
Here, _{Ptotal_act} = _{Pact_1} + _{Pact_2} + _{Pact_3} + _{Pact_4} + _{Pact_5} + _{Pact_6} + _{Pact_7}
P _{act_i + 1} : Actual rolling load of the downstream rolling stand (F _{i + 1} )

Next, the load balance maintaining unit 110, in accordance with the following equation (11), the rolling stand 161 to maintain load balance of the downstream roll stand 161 of the rolling stands _{161 (F i) (F i} + 1) A reduction position correction amount _{Dr_i} for (F _i ) is calculated (step S75).

_{D r_i = φ coef_i · ΔPr i} + 1 · Kp i · (1 + 1 / (T i · s)) (11)
Here, ΔPr _{i + 1} = Pr _act — _{i + 1} −Pr _set — _{i + 1}
Kp _i : Proportional gain
T _i : Integration time
s: Laplace operator

In Expression (11), ΔPr _{i + 1} is a deviation of the actual load ratio Pr _{act_i + 1 from} the set load ratio Pr _{set_i + 1 in} the downstream rolling stand 161 (F _{i + 1} ). Therefore, the load balance maintenance unit 110 corrects the set reduction position S _{set_i} of the rolling stand 161 (F _i ) in a direction to reduce the deviation ΔPr _{i + 1} .

In addition, Formula (11) is an example at the time of assuming proportional integral control, and in this case, the load balance maintenance part 110 calculates proportional gain Kp _i and integral time Ts _{i for} every rolling stand 161 (F _i ). Proportional integral control will be performed. Further, when calculating the reduction position correction amount _{Dr_i} , control of only proportional or integral may be assumed. Further, when considering the uniformity of the correction amount response, the reduction position correction amount is calculated according to a calculation formula including the speed of the steel plate 163 between the rolling stands 161, the distance between the rolling stands 161, the sampling period of the actual rolling value, and the like. D _{r — i} can also be calculated.

Next, the load balance maintenance unit 110, the rolling stands (F 1 _{to F 6)} determines whether the calculation of the reduction position correction amount D _{r_i} been completed for all (step S76), if not finished (No in step S76), the process from step S71 onward is executed again. Further, if all the calculation of rolling position correction amount D _{r_i} the rolling stands _(F 1 _{~F 6)} has been completed (Yes in step S76), and finishes the load balance keeping process.

  FIG. 8 is a diagram illustrating an example of a processing flow of the reduction position control process executed by the reduction position control unit 106. This reduction position control process is activated and executed at a constant cycle (for example, 1 second cycle).

The reduction position control unit 106 first acquires the set reduction position S _{set_i} of each rolling stand (F _i ) calculated by the setup control unit 101 prior to rolling of the steel plate 163 (step S81).

Next, the rolling position control unit 106 determines the rolling start of the steel plate 163 (step S82), and when the rolling has not started (No in step S82), repeatedly executes the rolling start determination process in step S82. To do. On the other hand, when the rolling of the steel plate 163 is started (Yes in step S82), the reduction position control unit 106 calculates the BISRA AGC for each rolling stand 161 (F _{1 to} F ₇ ), thereby The resulting reduction position correction amount D _{bsr_i} is calculated (step S83).

The BISRA AGC is an AGC function for compensating for the hardness unevenness and thickness deviation in the longitudinal direction of the steel plate 163 and obtaining a uniform thickness. The calculation formula of the reduction position correction amount D _{bsr — i} based on this BISRA AGC is shown in various documents, and for example, there is the following formula (12).

D _bsr — _i = A 1 — _i (P _{act — i} −P _{lock — i} ) (12)
Here, P _{lock_i} : Actual load when locking on at the tip of the steel plate 163
A _{1_i} : Proportional coefficient

Next, the reduction position control unit 106 calculates a gauge meter AGC for each rolling stand 161 (F _{1 to} F ₇ ), and calculates a reduction position correction amount D _{gmt_i} generated thereby (step S84). The gauge meter AGC is an AGC function for reducing a deviation from a desired delivery thickness of each rolling stand 161 (F _{1 to} F ₇ ) estimated by a gauge meter formula. The calculation formula of the reduction position correction amount D _{gmt_i} based on the gauge meter AGC is shown in various documents. For example, there is the following formula (13).

D _{gmt_i} = A 2 — _i (h _{target — i} −h _{est — i} ) (13)
Here, h _est — _i = S _act — _i + P _{act —i} / K _i + ΔD _i
h _{target_i} : Desirable exit side thickness of the rolling stand (F _i )
h _{est_i} : _{Estimated delivery} side thickness of the rolling stand (F _i )
S _{act_i} : _Actual rolling position of the rolling stand (F _i )
ΔD _i : Correction coefficient
K _i : Spring coefficient of the rolling stand (F _i )
A _{2_i} : Coefficient

Next, the reduction position control unit 106 calculates the monitor AGC for each rolling stand 161 (F _{1 to} F ₇ ), and calculates the reduction position correction amount D _{mnt_i} generated thereby (step S85). The monitor AGC is an AGC function for reducing the deviation of the exit side plate thickness of the rolling stand 161 (F ₇ ) detected by the multigauge 164 from the target plate thickness. The calculation formula of the reduction position correction amount D _{mnt_i} based on the monitor AGC is shown in various documents. For example, there is the following formula (14).

D _mnt — _i = A ₃ — _i (h _{target — 7} −h _{act — 7} ) (14)
Here, h _{target — 7} : Desirable exit side thickness (target thickness) of the rolling stand (F _i )
h _{act — 7} : _{Actual delivery} side thickness of the rolling stand (F _i ),
A _{3_i} : Coefficient

Next, the reduction position control unit 106 acquires a reduction position correction amount _{Dr_i} for maintaining the load balance calculated in the load balance maintenance process (see FIG. 7) by the load balance maintenance unit 110 (step S86). Then, the reduction position correction amounts D _{bsr_i} , D _{gmt_i} , D _{mnt_i} , D _{r_i} obtained in steps S83 to _S86 are _added to the set reduction position S _{set_i} obtained in step S81, and the reduction position S obtained by the addition. _i is output to each rolling stand 161 of the finishing mill 160 (step S87).

  Next, the reduction position control unit 106 determines whether or not the rolling of the steel plate 163 is finished (step S88), and when the rolling of the steel plate 163 is not finished (No in step S88), the steps S83 to S87 are performed. Repeat the process. On the other hand, when the rolling of the steel plate 163 is finished (Yes in step S88), the reduction position control process is finished.

FIG. 9 is a diagram schematically illustrating an example of a processing configuration in the load balance maintaining unit 110. That is, in FIG. 9, pressing position of the downstream stand 902 (F _{i + 1)} of the actual load ratio _Pr act_i _{+ 1} is set load ratio _Pr set_i _{+ 1} upstream so as to close to the stand 901 _{(F i)} S A processing configuration of the load balance maintaining unit 110 for controlling _i is shown.

As shown in FIG. 9, the load balance maintaining unit 110 is provided inside the reduction position control unit 106. In addition, an actual load ratio calculation unit 904 and a reduction position correction amount calculation unit 906 are provided inside the load balance maintenance unit 110. Here, the actual load ratio calculation unit 904 uses the actual rolling load P _{act_i} of each rolling stand 161 (F _{1 to} F ₇ ) acquired through the rolling actual result collection unit 107 to use each rolling stand 161 (F ₁ calculating the actual load ratio Pr _{Act_i} of to F _7). Further, the reduction position correction amount calculation unit 906 sets the influence coefficient φ _{coef_i} in the upstream stand 901 (F _i ) and the set load ratio Pr _{set_i + 1} of the actual load ratio Pr _{act_i + 1 in} the downstream stand 902 (F _{i + 1} ). the deviation? Pr _{i + 1} from, for calculating a pressing position correction amount D _{r_i} upstream stand 901 _{(F i)} on the basis of.

That is, the reduction position correction amount D _{r_i} obtained in this way is used to eliminate the deviation ΔPr _{i + 1} of the actual load ratio Pr _{act_i + 1 from} the set load ratio Pr _{set_i + 1} in the downstream stand 902 (F _{i + 1} ). It can be said that this is the correction amount of the reduction position. In other words, pressing position correction amount D _{r_i} the upstream stand 901 _{(F i),} the actual load ratio _Pr act_i _{+ 1} at the downstream stand 902 (F _{i + 1),} so as not to change the setting load ratio _Pr set_i _{+ 1} It can be said that the amount of correction of the reduction position for maintaining the above.

The output 910 from the reduction position correction amount calculation unit 906 is set by the setup control unit 101 after being added to the outputs from the BISRA AGC 111, the gauge meter AGC 112, and the monitor AGC 113 (not shown in FIG. 1). Correct the reduction position. Then, the corrected reduction position is output to the upstream stand 901 (F _i ).

In addition, since there is no thing corresponding to the downstream stand 902 (F _{i + 1} ) in FIG. 9 regarding the final rolling stand 161 (F ₇ ), the load balance maintaining unit 110 is not provided. In this case, the output 910 from the reduction position correction amount calculation unit 906, that is, the reduction position correction amount _{Dr_7} is regarded as zero.

As described above, according to the first embodiment of the present invention, the set load in which the actual load ratio Pr _{act_i + 1} of the downstream stand 902 (F _{i + 1} ) is appropriately set in advance during the rolling of the steel plate 163. The reduction position S _i of the upstream stand 901 (F _i ) is controlled so as to be the same as the ratio Pr set — _{i + 1} . That is, the control is performed so that the actual load ratio Pr _{act_i} approaches the set load ratio Pr _{set_i + 1} . Therefore, in the embodiment according to the present invention, an appropriate load balance set up in advance can be maintained even while the steel plate 163 is being rolled. As a result, the stability of the rolling operation is improved, so that the shape, width, and thickness of the steel plate 163 to be manufactured can be prevented from being disturbed, and the quality of the steel plate 163 as a product is improved.

<< Second Embodiment >>
FIG. 10 is a diagram showing an example of the configuration of the tandem rolling mill control device 100a according to the second embodiment of the present invention, centering on the processing configuration in the load balance maintaining unit 110. The tandem rolling mill control device 100a according to the second embodiment is the tandem according to the first embodiment only in that a control parameter extraction unit 1001, a control parameter storage unit 1002, and a control parameter search auxiliary storage unit 1003 are added. Different from the rolling mill control device 100.

The control parameter extraction unit 1001 obtains a value suitable for the steel plate 163 to be rolled next time for the proportional gain Kp _i and the integration time T _i that are control parameters used in the reduction position correction amount calculation unit 906. Then, the obtained values of the proportional gain Kp _i and the integration time T _i are output to the reduction position correction amount calculation unit 906 prior to rolling the steel plate 163. In obtaining this control parameter, the control parameter extraction unit 1001 refers to the control parameter storage unit 1002 and the control parameter search auxiliary storage unit 1003, details of which will be described later.

FIG. 11 is a diagram showing an example of the configuration of the control parameter table 1002T stored in the control parameter storage unit 1002 according to the second embodiment of the present invention. As shown in FIG. 11, in the control parameter table 1002T, the values of the control parameters used in the load balance maintenance unit 110 for each rolling stand 161 (F _{1 to} F ₆ ) are stored in association with the rolling specification number. . Here, the control parameter refers to the proportional gain Kp _i and the integration time T _i included in the equation (11).

Note that the rolling stands 161 _{(F 7),} since the downstream of the rolling stand 161 is not present, the load balance maintenance unit 110 is not provided. Therefore, there is no control parameter set for the rolling stand 161 (F ₇ ) in the control parameter table 1002T.

In the example of the control parameter table 1002T of FIG. 11, when the rolling specification number is “1-4”, the proportional gain Kp _i and the integration time T _i for each of the rolling stands 161 (F _i ) of i = 1 to 6 are used. Value is stored. This means that the rolling position correction process for maintaining the load balance is performed in all of the rolling stands 161 (F _{1 to} F ₆ ).

On the other hand, when the rolling specification number is “5”, the values of the proportional gain Kp ₆ and the integration time T ₆ are stored for the rolling stand 161 (F ₆ ), but the rolling stand 161 (F ₁ -F ₅ ) is not stored (the symbol "-" in the figure represents a blank). This means that the reduction position correction process for maintaining the load balance is performed only on the rolling stand 161 (F ₆ ) and not on the rolling stand 161 (F _{1 to} F ₅ ). Note that when the reduction position correction process is not performed, the output 910 from the reduction position correction amount calculation unit 906 may be set to zero.

In general, the rolling stand 161 in which the load ratio is most likely to vary and has the greatest influence on the quality of the steel plate 163 is the final rolling stand 161 (F ₇ ). For example, in the example of the rolling specifications numbers "5", only the actual load ratio Pr _{ACT_7} in the rolling stand 161 of the final stage (F _7), so as to maintain the set load ratio Pr _{Set_7} set by the setup controller 101 To do. Then, the rolling position correction for maintaining the load balance is performed only by the rolling stand 161 (F ₆ ). In this case, in the rolling stand 161 (F _{1 to} F ₅ ), the correction amount of the reduction position is small, so that the fluctuation of the reduction position is suppressed correspondingly, and the effect of stabilizing the rolling operation is also expected. can do.

When the rolling specification number is “6”, the control parameter table 1002T stores the values of the proportional gain Kp ₆ and the integration time T ₆ only for the two rolling stands 161 (F ₅ , F ₆ ). . In this case, the rolling stand 161 (F _{1 to} F ₄ ) does not perform the reduction position correction process for maintaining the load balance. Hereinafter, similarly, the three or more downstream rolling stands 161 may be appropriately subjected to a reduction position correction process for maintaining a load balance.

As described above, in this embodiment, by introducing the control parameter table 1002T, load balance maintenance control between two adjacent rolling stands 161 (F _i , F _{i + 1} ) By changing, it can be easily changed into various forms. Moreover, the change can be applied to load balance maintenance control in all the rolling stands 161 (F _{1 to} F ₆ ), and the load only between specific rolling stands 161 (F _i , F _{i + 1} ). It can also be applied to balance maintenance control.

  FIG. 12 is a diagram showing an example of the configuration of the control parameter search auxiliary table 1003T stored in the control parameter search auxiliary storage unit 1003 according to the second embodiment of the present invention. As shown in FIG. 12, the control parameter search auxiliary table 1003T is configured such that rolled steel plates 163 are stratified by steel type, plate thickness, and plate width, and rolling specification numbers are associated with the steel plates 163 for each layer. Is done.

  For example, when the steel type of the steel plate 163 to be rolled is “SS400”, the target plate thickness is “2.5 mm”, and the target plate width is “900 mm”, the steel plate 163 has a steel type “SS400” and a target plate thickness “ This corresponds to each layer of “2.0 to 3.0 mm” and a target plate width of “˜1000 mm”. Therefore, the rolling specification number of the steel plate 163 in this case is “3”.

  FIG. 13 is a diagram illustrating an example of a process flow of a control parameter calculation process executed by the control parameter extraction unit 1001 according to the second embodiment of the present invention. As shown in FIG. 13, the control parameter extraction unit 1001 is information transmitted from the host computer 50 via the setup control unit 101, and the steel type, target plate thickness, target plate of the steel plate 163 to be rolled next. The width is acquired (step S131). Next, the control parameter extraction unit 1001 refers to the control parameter search auxiliary table 1003T of FIG. 12 and extracts the rolling specification number associated with the steel type, target plate thickness, and target plate width of the steel plate 163 ( Step S132).

Next, the control parameter extraction unit 1001 extracts a control parameter associated with the extracted rolling specification number with reference to the control parameter table 1002T of FIG. 11 (step S133). At this time, control parameters corresponding to each of the rolling stands 161 _(F 1 ~F _{6) (proportional} gain _Kp 1 ~Kp ₆ and integral time _T 1 through T ₆₎ is extracted. Therefore, the control parameter extraction unit 1001 outputs the extracted control parameters to the rolling position correction amount calculation unit 906 of the corresponding rolling stand 161 (F _{1 to} F ₆ ) (step S134).

It should be noted that the following relationship is assumed between the rolling specifications of the rolled steel sheet 163 and the control parameters, which are related by the control parameter table 1002T and the control parameter search auxiliary table 1003T in FIGS. it can. For example, when the target plate thickness is thick, the rolling speed is slow, so the proportional gain Kp is reduced and the integration time T is set larger. Further, when the steel type of the steel plate 163 is a hard material, the proportional gain of the rolling stand 161 (F ₆ ) is set to be small so as to prevent the rolling from becoming unstable, considering that the load is not predicted at the tip.

  In the present embodiment, the load balance is controlled with the same combination of control parameters over the entire length of the steel plate 163. However, when the front end portion and the tail end portion of the steel plate 163 are rolled, the other portions are rolled. You may control by the combination of a different control parameter from time to time. For example, the proportional gain Kp is set small at the tip of the steel plate 163 in consideration of rolling stability, but the proportional gain Kp may be set at a slightly larger value in consideration of responsiveness at other portions. . Alternatively, such a setting is limited to the case where the steel plate 163 is a thin plate, and the same proportional gain Kp is used for the tip portion and other portions when the steel plate 163 is a thick plate where rolling is not likely to be unstable. The same integration time T may be set.

Further, the distal end portion of the steel plate 163, and controls the load balancing is limited to downstream of the rolling stand _{161 (F 5, F 6)} , the rolling of the tip ends, all the rolling stands 161 _(F 1 to F _The load balance may be controlled for ₆ ).

Further, the load balance maintaining unit 110 may be operated over the entire length of the steel plate 163, or may be operated after the tip portion of the steel plate 163 is rolled for a certain length or a certain time, or after the steel plate 163 has been rolled for a certain length or a certain time. The operation may be terminated before. Further, these controls may be different for each of the rolling stands 161 (F _{1 to} F ₆ ). For example, in the rolling stand 161 (F _{1 to} F ₅ ), the load balance maintaining unit 110 is operated over the entire length of the steel plate 163, and in the rolling stand 161 (F ₆ ), the load balance maintaining unit 110 is operated in a portion excluding the tip portion of the steel plate 163. May be. In the present embodiment, the above control can be easily realized by appropriately switching the rolling specification number in the longitudinal direction of the steel plate 163.

  In this embodiment, the control parameter extraction unit 1001 sets both the proportional gain Kp and the integration time T included in the reduction position correction amount calculation unit 906, but only one of them is set. Also good. Alternatively, the control parameter extraction unit 1001 may further set other control parameters such as a differential time.

  In the second embodiment as well, as in the first embodiment, it is possible to maintain a load balance set up in advance even during rolling. Furthermore, since the control parameter extraction unit 1001, the control parameter storage unit 1002, and the like are provided, the flexibility and diversity of control in the load balance maintenance unit 110 can be improved.

<< Modification of Second Embodiment >>
FIG. 14 is a diagram showing an example of the configuration of the control parameter search auxiliary table 1003Ta stored in the control parameter search auxiliary storage unit 1003 according to the modification of the second embodiment of the present invention. In the present modification, the configuration of the control parameter table 1002T is the same as that shown in FIG.

  In the control parameter search auxiliary table 1003Ta, the rolling specification number corresponds to each layer divided by the steel type difference, the target plate thickness difference, and the target plate width difference between the rolled steel plate 163 and the next rolled steel plate 163. Attached and configured. According to FIG. 14, for example, when the steel type difference between the rolled steel plate 163 and the next rolled steel plate 163 is “different steel type”, and the target plate thickness difference and target plate width difference are both “0”. Is associated with “3” as the rolling specification number. When the steel type difference is “different steel type”, the plate thickness difference is “7%”, and the plate width difference is “12%”, “4” is associated as the rolling specification number.

  FIG. 15 is a diagram illustrating an example of a process flow of a control parameter calculation process executed by the control parameter extraction unit 1001 in the modification of the second embodiment of the present invention. As shown in FIG. 15, the control parameter extraction unit 1001 first transmits the steel type difference between the steel plate 163 that has been rolled and the steel plate 163 that is to be rolled next, which is transmitted from the host computer 50 via the setup control unit 101. A target plate thickness difference and a target plate width difference are acquired (step S151). Next, the control parameter extraction unit 1001 refers to the control parameter search auxiliary table 1003Ta in FIG. 14 and extracts the rolling specification number associated with the steel type difference, the target plate thickness difference, and the target plate width difference ( Step S152).

Next, the control parameter extraction unit 1001 extracts a control parameter associated with the extracted rolling specification number with reference to the control parameter table 1002T of FIG. 11 (step S153). At this time, control parameters corresponding to each of the rolling stands 161 _(F 1 ~F _{6) (proportional} gain _Kp 1 ~Kp ₆ and integral time _T 1 through T ₆₎ is extracted. Therefore, the control parameter extraction unit 1001 outputs the extracted control parameters to the rolling position correction amount calculation unit 906 of the corresponding rolling stand 161 (F _{1 to} F ₆ ) (step S154).

It should be noted that the following relationship can be assumed between the steel type difference, the plate thickness difference, the plate width difference, and the control parameter between the rolled steel plate 163 and the next rolled steel plate 163. For example, when the steel type difference is a different steel type, the plate thickness deviation at the tip of the steel plate 163 becomes large. In order to eliminate this, the reduction position of the rolling stand 161 (F ₇ ) is corrected by the monitor AGC 113. The frequency of movement increases. Therefore, in such a case, it is preferable to set a small value as the proportional gain Kp and a large value as the integration time T in order to allow the leading end of the steel plate 163 to pass through stably. In addition, when the plate thickness difference is large, the plate thickness deviation at the tip of the steel plate 163 may be further increased. Therefore, it is preferable to set the proportional gain Kp smaller and the integration time T larger.

  Further, in the modification of the present embodiment, the difference in the steel type is stratified according to whether it is “same steel type” or “different steel type”, but further, the difference in steel type can be stratified more precisely by using “strength difference” or the like. Good.

  Even in the modification of the second embodiment, the same effect as that of the second embodiment can be obtained.

  The present invention is not limited to the embodiments and modifications described above, and includes various modifications. For example, the above-described embodiments and modifications have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. In addition, a part of the configuration of an embodiment or modification can be replaced with the configuration of another embodiment or modification, and the configuration of another embodiment or modification can be replaced with another embodiment or modification. It is also possible to add the following configuration. In addition, with respect to a part of the configuration of each embodiment or modification, the configuration included in another embodiment or modification may be added, deleted, or replaced.

DESCRIPTION OF SYMBOLS 50 High-order computer 100,100a Tandem rolling mill control apparatus 101 Setup control part 102 Draft schedule memory | storage part 102T Draft schedule table 103 Speed pattern memory | storage part 103T Speed pattern table 104 Set load ratio calculation part 105 Influence coefficient calculation part 106 Rolling-down position control part 107 Rolling record collection unit 108 Speed control unit 110 Load balance maintenance unit 111 BISRA AGC
112 gauge meter AGC
113 Monitor AGC
150 Control target 160 Finishing mill 161 Rolling stand 162 Work roll 163 Steel plate (rolled material)
164 Multi-gauge 165 Rough material (rolled material)
901 Upstream stand (second rolling stand)
902 Downstream stand (first rolling stand)
904 Actual load ratio calculation unit 906 Reduction position correction amount calculation unit 910 Output of reduction position correction amount calculation unit 1001 Control parameter extraction unit 1002 Control parameter storage unit 1003 Control parameter search auxiliary storage unit 1002T Control parameter table 1003T, 1003Ta Control parameter search auxiliary Table P _{set_i} Rolling stand (F _i ) Setting rolling load P _{act_i} Rolling stand (F _i ) Actual rolling load Pr _{set_i} Rolling stand (F _i ) Setting load ratio Pr _{act_i} Rolling stand (F _i ) Actual load ratio ΔPr _i rolling stands _{(F i)} set pressing position S _{Act_i} rolling stands pressing position S _{Set_i} rolling stands of the deviation S _i roll stand from set load ratio of actual load ratio _{(F i) (F i)} of the _{(F i)} influence coefficient D _{r_i} under actual pressing position phi _{Coef_i} rolling stands _{(F i)} Rolling stands (F _{i + 1)} pressing position correction amount D _{Gmt_i} rolling based on BISRA AGC of rolling position correction amount D _{Bsr_i} rolling stand of the rolling stand upstream to maintain a load balance _{(F i) (F i)} of the stand pressing position correction amount based on the monitoring of AGC _{(F i)} of the pressing position correction amount D _{Mnt_i} rolling stand based on the gauge meter AGC _{(F i)}

Claims (11)

A tandem rolling mill control device for controlling a tandem rolling mill that continuously rolls a material to be rolled by a plurality of rolling stands,
Prior to rolling the material to be rolled, for each of the plurality of rolling stands, a set-up control unit that sets a set rolling load and a set reduction position for realizing the target plate thickness of the material to be rolled,
For the first rolling stand that is at least one rolling stand selected from the plurality of rolling stands, the set rolling load set for the first rolling stand and the set for each of the plurality of rolling stands Based on a set rolling load, a set load ratio calculating unit that calculates a set load ratio for the first rolling stand;
The actual load ratio for the first rolling stand based on the actual rolling load obtained from the first rolling stand and the actual rolling load obtained from each of the plurality of rolling stands during the rolling of the material to be rolled. An actual load ratio calculation unit for calculating
A second rolling stand located upstream of the first rolling stand so that a deviation from the set load ratio of the actual load ratio in the first rolling stand is reduced during rolling of the material to be rolled. A reduction position control unit for controlling the reduction position of
A tandem rolling mill control device comprising: The first rolling stand is
Of the plurality of rolling stands, the rolling stage in the last stage located on the most downstream side in the direction in which the material to be rolled is rolled, or the rolling in the first stage located in the most upstream, including the rolling stand in the last stage. The tandem rolling mill control device according to claim 1, wherein the tandem rolling mill control device is a plurality of adjacent rolling stands that do not include a stand. The second rolling stand is
The tandem rolling mill control device according to claim 2, wherein the tandem rolling mill control device is a rolling stand adjacent to the upstream side of the first rolling stand. The set load ratio calculation unit
A value obtained by dividing the set rolling load set for each of the plurality of rolling stands by the sum of the set rolling loads set for each of the plurality of rolling stands is calculated as a set load ratio for each of the plurality of rolling stands,
The actual load ratio calculation unit
A value obtained by dividing the actual rolling load obtained by each of the plurality of rolling stands by the sum of the actual rolling loads obtained by each of the plurality of rolling stands is calculated as the actual load ratio of each of the plurality of rolling stands. The tandem rolling mill control device according to claim 1. The reduction position controller is
An influence coefficient calculated as a reduction position correction amount of the second rolling stand necessary for correcting the load ratio of the first rolling stand by a unit amount, the actual load ratio in the first rolling stand, and the 4. The tandem rolling mill control device according to claim 3, further comprising a load balance maintaining unit that calculates a correction position correction amount of the second rolling stand based on a deviation from a set load ratio. 5. For each rolling specification of the material to be rolled, a control parameter storage unit that stores control parameters used in calculation of a reduction position correction amount in the load balance maintaining unit,
Prior to rolling the material to be rolled, a control parameter extracting unit that extracts a control parameter corresponding to the rolling specification of the material to be rolled from the control parameter storage unit and outputs the extracted control parameter to the load balance maintaining unit. When,
The tandem rolling mill control device according to claim 5, further comprising: In the control parameter storage unit, for each rolling specification of the material to be rolled, a rolling position correction amount of the rolling stand is calculated for each rolling stand excluding the final rolling stand among the plurality of rolling stands. Information indicating whether or not
The tandem rolling mill according to claim 6, wherein the load balance maintaining unit calculates a rolling position correction amount of the rolling stand only when the instructed information is information instructing calculation. Control device. A computer that controls a tandem rolling mill that continuously rolls a material to be rolled by a plurality of rolling stands,
Prior to rolling the material to be rolled, for each of the plurality of rolling stands, a first step of setting a set rolling load and a set reduction position for realizing the target plate thickness of the material to be rolled;
For the first rolling stand that is at least one rolling stand selected from the plurality of rolling stands, the set rolling load set for the first rolling stand and the set for each of the plurality of rolling stands A second step of calculating a set load ratio for the first rolling stand based on a set rolling load;
The actual load ratio for the first rolling stand based on the actual rolling load obtained from the first rolling stand and the actual rolling load obtained from each of the plurality of rolling stands during the rolling of the material to be rolled. A third step of calculating
A second rolling stand located upstream of the first rolling stand so that a deviation from the set load ratio of the actual load ratio in the first rolling stand is reduced during rolling of the material to be rolled. A fourth step of controlling the reduction position of
A tandem rolling mill control method characterized in that The first rolling stand is
Of the plurality of rolling stands, the rolling stage in the last stage located on the most downstream side in the direction in which the material to be rolled is rolled, or the rolling in the first stage located in the most upstream, including the rolling stand in the last stage. The tandem rolling mill control method according to claim 8, wherein the tandem rolling mill control method is a plurality of adjacent rolling stands that do not include a stand. The second rolling stand is
The tandem rolling mill control method according to claim 9, wherein the rolling stand is adjacent to the upstream side of the first rolling stand. The computer
In the second step,
A value obtained by dividing the set rolling load set for each of the plurality of rolling stands by the sum of the set rolling loads set for each of the plurality of rolling stands is calculated as a set load ratio for each of the plurality of rolling stands,
In the third step,
A value obtained by dividing the actual rolling load obtained by each of the plurality of rolling stands by the sum of the actual rolling loads obtained by each of the plurality of rolling stands is calculated as the actual load ratio of each of the plurality of rolling stands. The tandem rolling mill control method according to claim 8.

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