JP7258790B2 - Rolling control system and rolling control method - Google Patents

Description

The present invention relates to a rolling control system and a rolling control method.

In the rolling operation, it is known that the tail end of the material to be rolled is not stable at the center position in the width direction of the rolling roll, and the tail end moves toward the end in the width direction. Such a phenomenon is called "meandering" of the tail tip.

Japanese Patent Laid-Open No. 2010-247177 discloses a conventional technique for suppressing meandering of the tail end. This conventional technique is a technique for suppressing meandering during rolling in a finishing mill. In this prior art, control (differential load control) is performed based on the difference between the load on the operation side (work side) of the finishing mill and the load on the drive side of the finishing mill.

JP 2010-247177 A

By the way, a winder for winding the material to be rolled is installed downstream of the finishing mill. A pair of pinch rolls is installed between the finishing mill and the winder. Here, the role of a general pinch roll is to guide the material to be rolled sent out from the finishing mill to the winder.

The differential load control of the above prior art is applied to the rolling rolls of the finishing mill. Therefore, while the finishing rolling mill is feeding the material to be rolled, execution of this differential load control is expected to suppress meandering. However, after the trailing edge exits the finishing mill, only the pinch rolls apply the load to the rolled material. Therefore, there was a possibility that the tail tip meandered during this period.

The present invention has been made in view of the above problems, and an object thereof is to provide a technique for suppressing meandering of the tail end of a material to be rolled after it exits the finishing mill.

A first invention is a rolling control system having the following features.
The rolling control system includes a finishing mill, a winder, a pair of pinch rolls, a pinch roll load gauge, and a controller.
The winder winds up the material to be rolled sent out from the finishing mill.
The pinch rolls are provided between the finishing mill and the winder.
The pinch roll load cell measures first and second loads. The first load is the load on the work side of the pinch roll. The second load is the load on the drive side of the pinch roll.
The controller controls the gap between the pinch rolls.
The control device controls a load target value and an adjustment gain during a period from the timing when the tip of the material to be rolled enters the pinch roll to the timing when the tail end of the material to be rolled exits the finishing mill. Feedforward control is performed to output the calculated gap command value to the pinch roll, and after the timing at which the tail end exits the finishing mill , from the execution of the feedforward control, the first and second The execution of feedback control is switched to output to the pinch roll a gap command value calculated based on the difference between the load measurement values and the adjustment gain .

A second invention is a rolling control method having the following features.
The rolling control method is a method of controlling a gap between a pair of pinch rolls provided between a finishing mill and a winder for winding the material to be rolled sent out from the finishing mill.
In the rolling control method, first and second loads are measured. The first load is the load on the work side of the pinch roll. The second load is the load on the drive side of the pinch roll.
In the rolling control method, feedforward control of outputting the gap command value calculated based on the target value of the load and the adjustment gain to the pinch roll, and the difference between the measured values of the first and second loads Feedback control is executed to output the gap command value calculated by the above to the pinch roll. The feedforward control is executed between the timing when the leading end of the material to be rolled enters the pinch rolls and the timing when the tail end of the material to be rolled exits the finishing mill. The feedback control is executed after switching from the execution of the feedforward control after the timing at which the tail end exits the finishing mill .

According to the first or second invention, from the timing when the tip of the material to be rolled enters the pinch rolls to the timing when the tail end of the material to be rolled exits the finishing mill, the target value of the load and the adjustment gain are Feedforward control is performed to output the gap command value calculated based on to the pinch roll. Further, after the timing when the tail end of the material to be rolled leaves the finishing mill , the gap command value calculated based on the difference between the measured values of the first and second loads is pinched from the execution of this feedforward control. Switched to execution of feedback control output to roll. Therefore, it is possible to suppress meandering of the tail end of the rolled material not only before the timing when the tail end of the material to be rolled leaves the finishing rolling mill, but also after the timing when the tail end exits the finishing rolling mill. becomes. Therefore, it is possible to improve the shape of the material to be rolled which is wound by the winding machine and to improve the quality of the product.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example of the rolling control system which concerns on embodiment of this invention. It is a block diagram showing an example of the control configuration of the pinch roll in the embodiment.

Hereinafter, a rolling control system and a rolling control method according to embodiments of the present invention will be described with reference to the drawings.

1. Configuration of Rolling Control System FIG. 1 is a diagram showing a configuration example of a rolling control system (hereinafter also simply referred to as "system") according to an embodiment of the present invention. A system 100 shown in FIG. 1 includes rolling stands 20 and 30, pinch rolls 40, a winder 50, and a control device 60 as equipment for manufacturing a material 10 to be rolled such as a steel plate.

Rolling stands 20 and 30 constitute a finishing mill. A finishing mill has at least two rolling stands. Rolling stand 20 is the most upstream of these stands. Rolling stand 30 is the most downstream of these stands. The rolling stand 30 is a so-called last stand.

The rolling stand 20 comprises an upper rolling roll 21 and a lower rolling roll 22 . The material 10 to be rolled is crushed by these rolling rolls. The rolling stand 20 also comprises a roll-down device 23 that rolls down the upper rolling roll 21 . A load meter 24 is attached to the rolling stand 20 . The load meter 24 measures the load FMR in the width direction of the upper roll 21 . The load FMR includes a workside load FMR_WS and a driveside load FMR_DS. The "work side" means one end in the width direction, and the "drive side" means the other end in the width direction.

The rolling stand 30 comprises an upper rolling roll 31 and a lower rolling roll 32 . The rolling stand 30 also comprises a roll-down device 33 that rolls down the upper rolling roll 31 . These configurations are the same as those of the rolling stand 20 . A load meter 34 is attached to the rolling stand 30 . The load cell 34 has the same configuration as the load cell 24 . The material to be rolled 10 flowing downstream of the rolling stand 30 is also called a "strip".

The pinch roll 40 includes an upper pinch roll 41 and a lower pinch roll 42 . The pinch rolls 40 are also equipped with a roll-down device 43 that rolls down the upper pinch rolls 41 . These configurations are basically the same as those of the rolling stand 20 . A load cell 44 is attached to the pinch roll 40 . The load meter 44 measures the load FPR in the width direction of the upper pinch roll 41 . The load FPR includes a work side load FPR_WS and a drive side load FPR_DS.

The winder 50 winds up the material to be rolled 10 (that is, strip) delivered from the finishing mill.

Controller 60 is typically a computer including a processor, memory, input/output interfaces, and the like. The processor executes various rolling controls according to programs stored in the memory. Various types of rolling control include load control and position control, which will be described later. Load cells 24, 34 and 44 are connected to the input interface. The screw down devices 23, 33 and 43 are connected to the output interface.

2. Load Control and Position Control Load control is performed for the purpose of suppressing meandering of the tail end of the material 10 to be rolled. Load control includes first load control and second load control. The first load control is performed while the tail end of the material 10 to be rolled is located between the rolling stand 20 and the rolling stand 30 . A second load control is performed while this tail end is located between the roll stand 30 and the pinch rolls 40 .

In the first load control, the roll gap TMS_GAP of the rolling stand TMS located immediately downstream of the tail end of the material 10 to be rolled is controlled. “Rolling stand TMS” means a rolling stand of a finishing mill that is located downstream of the tail end of the material to be rolled 10 and that is the shortest distance from the tail end. "Roll gap TMS_GAP" means a gap between a pair of rolling rolls of rolling stand TMS.

Control of the roll gap TMS_GAP is performed as feedback control based on the difference between the load FMR_WS measured at the rolling stand TMS and the load FMR_DS (hereinafter also referred to as "differential load DFMR"). This feedback control is differential load control in the rolling stand TMS. In this feedback control, the differential load DFMR is multiplied by an adjustment gain. This adjustment gain is a gain for converting the differential load DFMR into a roll gap.

In this feedback control, the differential load DFMR after conversion is also added to the current roll gap target value REF_MR_GAP in the rolling stand TMS. The target value REF_MR_GAP includes a work-side target value REF_MR_GAP_WS and a drive-side target value REF_MR_GAP_DS. The target value REF_MR_GAP to which the differential load DFMR is added is input to the reduction device of the rolling stand TMS as a gap command value. Note that the feedback control based on the differential load DFMR is not limited to the control described here, and known control may be applied.

In the first load control, the roll gap PR_GAP of the pinch rolls 40 is also controlled. “Roll gap PR_GAP” means the gap between the upper pinch roll 41 and the lower pinch roll 42 . Control of the roll gap PR_GAP is performed as feedforward control. In this feedforward control, the target value REF_PR_F of the load is multiplied by the adjustment gain. This adjustment gain is a gain for converting the load into the roll gap. The converted target value REF_PR_F is input to the screw down device 43 as a gap command value.

However, control of the roll gap PR_GAP is performed after the timing at which the tip of the material 10 to be rolled enters the pinch rolls 40 . Position control of the upper pinch roll 41 is performed before the tip of the material 10 to be rolled enters the pinch roll 40 . Prior to this timing, the tip of the material 10 to be rolled is located upstream of the pinch rolls 40 . Therefore, the position of the upper pinch roll 41 should be at an appropriate position, and therefore this position control is executed as feedforward control. In this feedforward control, the roll gap target value REF_PR_GAP is input to the screw down device 43 as a gap command value.

The first load control described here is an example of conventional rolling control for the purpose of suppressing meandering of the tail end of the material 10 to be rolled. A feature of this embodiment resides in the second load control described below.

Similar to the first load control, the second load control controls the roll gap PR_GAP. However, in the second load control, the roll gap PR_GAP is controlled as a feedback control based on the difference between the load FPR_WS measured by the load meter 44 and the load FPR_DS (hereinafter also referred to as "differential load DFPR"). executed. This feedback control is differential load control in the pinch rolls 40 . In this feedback control, the differential load DFPR is multiplied by the adjustment gain. This adjustment gain is a gain for converting the differential load DFPR into a roll gap.

In this feedback control, the differential load DFPR after conversion is added to the current roll gap target value REF_PR_GAP. The target value REF_PR_GAP includes a work-side target value REF_PR_GAP_WS and a drive-side target value REF_PR_GAP_DS. The target value REF_PR_GAP to which the converted differential load DFPR is added is input to the screw-down device 43 as a gap command value.

3. Rolling Control in Pinch Rolls Hereinafter, a detailed description will be given focusing on the rolling control with the pinch rolls 40 as the control target. FIG. 2 is a block diagram showing an example of the control configuration of pinch rolls 40 in the embodiment.

A target value REF_PR_F shown in the second row of FIG. 2 is a target value of the load FPR of the pinch rolls 40 and is input to the divider 61a. The divider 61a divides the input value by 2 to equally divide the target value REF_PR_F for the work side and the drive side.

The two target values after division processing are input to the multiplier 62a. The multiplier 62a multiplies these input values by the adjustment gain GAIN. This adjustment gain GAIN is a gain for converting a load into a roll gap.

The two target values after multiplication are input to the limiter 63a. If the work-side input value exceeds the upper limit of the target value REF_PR_F, the limiter 63a outputs the upper limit to the adder 64a. If this input value is below the lower limit of target value REF_PR_F, limiter 63a outputs the lower limit to adder 64a. When this input value is between the upper limit and the lower limit, the limiter 63a outputs the input value as it is to the adder 64a. The processing for the input value for the drive side is the same as the processing described above, except that the output destination is replaced with the adder 64b.

The adder 64a calculates the target value REF_PR_GAP_WS based on the input value. Adder 64b calculates a target value REF_PR_GAP_DS based on the input value. These target values are input to the screw-down device 43 as gap command values.

The load difference DFPR shown in the fifth row in FIG. 2 is a value obtained by subtracting the load FPR_DS on the drive side from the load FPR_WS on the work side (DFPR=FPR_WS-FPR_DS), and is input to the divider 61b. The divider 61b divides the input value by 2 so as to equally divide the differential load DFPR for the work side and the drive side.

The difference load DFPR after division processing is input to the multiplier 62b. The multiplier 62b multiplies the input value by the adjustment gain GAIN. This adjustment gain GAIN is a gain for converting a load into a roll gap.

The differential load DFPR after multiplication processing is input to the limiter 63b. The limiter 63b outputs the upper limit to the adder 64c when the input value for the work side exceeds the upper limit of the differential load DFPR. If this input value is below the lower limit of the differential load DFPR, the limiter 63b outputs the lower limit to the adder 64c. When this input value is between the upper limit and the lower limit, the limiter 63b outputs the input value as it is to the adder 64c. The processing of the input value for the drive side is the same as the processing described above, except that the output destination is replaced with the multiplier 62c.

Adder 64c calculates a target value REF_PR_GAP_WS based on the input value. The multiplier 62c multiplies the input value by -1 and outputs the result to the adder 64d. Adder 64d calculates a target value REF_PR_GAP_DS based on the input value. These target values are input to the screw-down device 43 as gap command values.

The switches 66a to 66c switch between ON and OFF based on the trigger signal Metal_In from the trigger circuit 65a. The trigger signal Metal_In is output when the load meter 44 detects the load of the upper pinch roll 41 in the width direction. Before outputting the trigger signal Metal_In, the switch 66a is in the ON state, and the switches 66b and 66c are in the OFF state. When the trigger signal Metal_In is output, the switch 66a is switched from ON to OFF, and the switches 66b and 66c are switched from OFF to ON.

That is, before the trigger signal Metal_In is output, the target value REF_RP_GAP shown in the third stage of FIG. 2 is input to the adders 64a and 64b via the switch 66a. On the other hand, the output from the limiter 63a is cut off by the switch 66b. After the timing at which the trigger signal Metal_In is output, the target value REF_RP_GAP is blocked by the switch 66a. On the other hand, the output from limiter 63a is input to adders 64a and 64b via switch 66b. With such a control configuration, execution of two types of feedforward control is switched before and after the timing at which the trigger signal Metal_In is output.

The switches 66d and 66e switch ON and OFF based on the trigger signal Metal_Out from the trigger circuit 65b. The trigger signal Metal_Out is output when the load meter 34 detects the load of the upper rolling roll 31 in the width direction. Before outputting the trigger signal Metal_Out, the switches 66d and 66e are in the OFF state. When the trigger signal Metal_Out is output, these switches are switched from OFF to ON.

That is, before the trigger signal Metal_Out is output, the differential load DFPR is not input to the divider 61b. Therefore, the output from the limiter 63b is not input to the adder 64c and the multiplier 62c until the trigger signal Metal_Out is output after the trigger signal Metal_In is output. Therefore, during this period, feedforward control is performed based on the output from the limiter 63a. After the timing at which the trigger signal Metal_Out is output, feedback control is performed in which the output from the limiter 63a is corrected by the adders 64c and 64d. With such a control configuration, the feedforward control is executed before the timing at which the trigger signal Metal_Out is output, and the execution is switched to the feedback control after this timing.

4. Effect of Embodiment According to the embodiment described above, the first load control is performed while the tail end of the material to be rolled 10 is positioned between the rolling stand 20 and the rolling stand 30 . After the timing at which the tail end of the material 10 to be rolled leaves the rolling stand 30, the second load control is performed in a manner that switches from the execution of the first load control. As described above, the first load control has conventionally been performed for the purpose of suppressing meandering of the tail end of the material 10 to be rolled. Therefore, by performing the second load control by switching from the first load control, the material to be rolled 10 is controlled not only before the timing when the tail end of the material to be rolled 10 exits the rolling stand 30 but also after this timing. It is possible to suppress meandering of the tail end of the . Therefore, it is possible to improve the shape of the strip wound by the winder 50 and improve the quality of the product.

10 Material to be rolled 20, 30 Rolling stand 21, 31 Upper rolling roll 22, 32 Lower rolling roll 23, 33, 43 Reduction device 24, 34, 44 Load cell 40 Pinch roll 41 Upper pinch roll 42 Lower pinch roll 50 Winder 60 control device 100 rolling control system

Claims (2)

a finishing rolling mill;
a winding machine for winding the material to be rolled sent out from the finishing rolling mill;
A pair of pinch rolls provided between the finishing rolling mill and the winding machine;
a pinch roll load meter that measures a first load that is the load on the work side of the pinch roll and a second load that is the load on the drive side of the pinch roll;
a controller for controlling the gap between the pinch rolls;
A rolling control system comprising:
Based on the target value of the load and the adjustment gain, the control device controls the period from the timing when the leading edge of the material to be rolled enters the pinch roll to the timing when the trailing edge of the material to be rolled exits the finishing mill. Feedforward control is performed to output the calculated gap command value to the pinch roll, and after the timing at which the tail end exits the finishing mill , from the execution of the feedforward control, the first and second Switching to execution of feedback control for outputting to the pinch roll a gap command value calculated based on the difference between the load measurement values and the adjustment gain
A rolling control system characterized by: A rolling control method for controlling a gap between a pair of pinch rolls provided between a finishing rolling mill and a winding machine for winding a material to be rolled sent out from the finishing rolling mill,
Measure a first load that is a load on the work side of the pinch roll and a second load that is a load on the drive side of the pinch roll,
Between the timing when the tip of the material to be rolled enters the pinch roll and the timing when the tail end of the material to be rolled exits the finishing mill, a gap command calculated based on the target value of the load and the adjustment gain Execute feedforward control that outputs a value to the pinch roll,
After the timing at which the tail end exits the finishing mill, the gap command value calculated based on the difference between the measured values of the first and second loads and the adjustment gain is changed from the execution of the feedforward control. Switch to execution of feedback control output to the pinch roll
A rolling control method characterized by:

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