JP7716484B2 - Leveling control device, rolling equipment equipped with same, and leveling control method - Google Patents

Description

The present invention relates to a leveling control device, a rolling mill equipped with the same, and a leveling control method.

Patent Document 1 describes an example of a method for controlling strip bow in a tandem mill that enables comprehensive, integrated control of the tandem mill, thereby reliably preventing strip bowing not only at the exit of the final rolling mill stand but also throughout the entire mill. It describes a method for controlling strip bow in a tandem mill in which the strip is inserted sequentially through multiple rolling mill stands arranged in series, with rolling performed simultaneously in each rolling mill stand, and the left and right reduction amounts of each rolling mill stand adjusted based on the detected value of the left and right tension deviation of the strip between each rolling mill stand to eliminate the left and right tension deviation of the strip between each rolling mill stand. The method describes that the reduction amount of each rolling mill stand is adjusted based on the detected value of the left and right tension deviation of the strip exiting that rolling mill stand, ahead of the detection position, and this adjustment operation is carried out sequentially toward the entry rolling mill stand.

Special Publication No. 63-29605

It is well known that in rolling equipment with high rolling speeds, large curvatures in strips can occur due to differences in the reduction amount between the left and right sides of the rolling mill, or differences in thickness between the left and right sides of the material. When such bending occurs, product quality is compromised, so there is a strong demand for the development of control methods to prevent this bending.

One method for preventing strip bending is described in Patent Document 1, for example. Patent Document 1 discloses that based on the tension deviation between the left and right sides of the strip between each rolling mill stand, the roll reduction is controlled in the stand ahead of the tension detection position, and this control is then carried out sequentially toward the entry side.

However, since the allowable tension deviation varies depending on the plate width and tension deviation includes measurement errors, it became clear that there is a risk of accuracy decreasing if the measured tension deviation is used directly for roll reduction control, and that there is room for improvement.

The present invention provides a leveling control device that can improve the accuracy of roll control for each stand in a hot rolling line in which multiple rolling stands are arranged compared to conventional methods, as well as rolling equipment equipped with the same and a leveling control method.

The present invention includes a plurality of means for solving the above-mentioned problems. One example of such a means is a leveling control device for a hot rolling line in which a plurality of rolling stands are arranged, the leveling control device comprising: a torque acquisition unit that determines a torque distribution applied in the width direction of a steel sheet between each of the plurality of rolling stands from torque measured by each shapemeter provided between the plurality of rolling stands; a first-order component calculation unit that determines a tension distribution in the width direction from the determined torque distribution and determines a first-order component when the tension distribution of the steel sheet is expressed as a polynomial from the tension distribution; and a first-order component calculation unit that calculates a leveling correction amount for the rolling stands provided on the upstream side of rolling among the plurality of rolling stands, the first rolling stand being one stage upstream from the final stage excluding the final rolling stand, based on the determined first-order component. and a leveling amount changing unit that changes the leveling amount in sequence from the rolling stand one stage upstream of the final stand among the plurality of rolling stands toward the rolling upstream side, excluding the final rolling stand , based on the leveling correction amount calculated for each stage , wherein the torque obtaining unit obtains a torque distribution applied in the width direction of the steel plate downstream of the final stand from the torque of the steel plate obtained by a shape meter provided downstream of the final stand among the plurality of rolling stands, and the leveling amount changing unit also changes the leveling amount of the final stand before the rolling stand one stage upstream of the final stage .

The present invention makes it possible to improve the accuracy of roll gap control for each stand in a hot rolling line with multiple rolling stands compared to conventional methods. Other issues, configurations, and effects will become clearer in the following description of the examples.

1 is a schematic diagram showing the configuration of a rolling facility equipped with a leveling control device according to a first embodiment of the present invention; 5 is a diagram showing an example of a method for determining the allowable range of a first-order component in the leveling control device of the first embodiment. FIG. 4 is a flowchart showing an example of a flow of correction control of a leveling amount in the leveling control device of the first embodiment. FIG. 5 is a schematic diagram showing the configuration of a rolling facility equipped with a leveling control device according to a second embodiment of the present invention. 10 is a flowchart showing an example of a flow of correction control of a leveling amount in the leveling control device according to the second embodiment. FIG. 10 is a schematic diagram showing the configuration of a rolling facility equipped with a leveling control device according to a third embodiment of the present invention. 10 is a flowchart showing an example of a flow of correction control of a leveling amount in the leveling control device according to the third embodiment.

Below, examples of the leveling control device of the present invention, the rolling equipment equipped with the same, and the leveling control method are described with reference to the drawings.

In the drawings used in this specification, identical or corresponding components are designated by the same or similar symbols, and repeated explanations of these components may be omitted.

In addition, the material to be rolled in this invention is not limited to steel plate, but can generally be a strip of metal material that can be rolled, and the type is not particularly limited; in addition to steel plate, non-ferrous materials such as aluminum and copper can also be used.

Example 1
A first embodiment of a leveling control device, a rolling mill equipped with the same, and a leveling control method according to the present invention will be described with reference to FIGS. 1 to 3. FIG.

First, the overall configuration of the rolling equipment, including the leveling control device, will be explained using Figure 1. Figure 1 is a schematic diagram showing the configuration of the rolling equipment equipped with the leveling control device of this embodiment 1.

The rolling equipment 200 shown in Figure 1 is a finishing rolling equipment for rolling steel plate 1, and is equipped with F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, F7 stand 70, cameras 81, 82, 83, 84, 85, 86, shape meters 91, 92, 93, 94, 95, 96, 97, a leveling control device 150, etc.

The rolling equipment 200 is not limited to having seven rolling stands as shown in Figure 1, but may have a minimum of three stands or more.

Each of F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 is a rolling mill equipped with an upper work roll, a lower work roll, an upper backup roll that contacts and supports the upper work roll and the lower work roll, and screw-down devices 11, 21, 31, 41, 51, 61, 71 installed above the upper backup rolls, and load detectors 12, 22, 32, 42, 52, 62, 72. Information on the rolling load measured by load detectors 12, 22, 32, 42, 52, 62, 72 is transmitted to leveling control device 150 via communication line 110.

In addition, a six-stage configuration can be achieved by providing upper and lower intermediate rolls between each of the upper and lower work rolls and each of the upper and lower backup rolls. The roll configuration of a rolling mill is not limited to the above-mentioned form, and it is sufficient to have at least upper and lower work rolls.

Shape meters 91, 92, 93, 94, 95, and 96 are measuring instruments that are installed between F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70, respectively, and measure the torque of steel plate 1. They are also capable of detecting the tension distribution in the plate width direction and are capable of detecting the position of steel plate 1.

Information on the surface shape of the steel sheet 1 at the exit side of F1 stand 10 (entrance side of F2 stand 20) measured by the shape meter 91 is transmitted to the leveling control device 150 via the communication line 110. Information on the surface shape of the steel sheet 1 at the exit side of F2 stand 20 (entrance side of F3 stand 30) measured by the shape meter 92 is transmitted to the leveling control device 150 via the communication line 110. Information on the surface shape of the steel sheet 1 at the exit side of F3 stand 30 (entrance side of F4 stand 40) measured by the shape meter 93 is transmitted to the leveling control device 150 via the communication line 110. Information on the surface shape of the steel sheet 1 at the exit side of F4 stand 40 (entrance side of F5 stand 50) measured by the shape meter 94 is transmitted to the leveling control device 150 via the communication line 110. Information on the surface shape of the steel sheet 1 at the exit side of F5 stand 50 (entrance side of F6 stand 60) measured by the shape meter 95 is transmitted to the leveling control device 150 via the communication line 110. Information on the surface shape of the steel sheet 1 at the exit side of F6 stand 60 (entrance side of F7 stand 70) measured by the shape meter 96 is transmitted to the leveling control device 150 via the communication line 110.

Like the shape meter 91, the shape meter 97 is a measuring device that measures the surface shape of the steel plate 1 and is installed on the outlet side of the F7 stand 70. Information on the surface shape of the steel plate 1 at the outlet side of the F7 stand 70 measured by the shape meter 97 is transmitted to the leveling control device 150 via the communication line 110.

Camera 81 is located at a position where it can capture images including the steel sheet 1 on the exit side of F1 stand 10 and the entry side of F2 stand 20. Camera 82 is located at a position where it can capture images including the steel sheet 1 on the exit side of F2 stand 20 and the entry side of F3 stand 30. Camera 83 is located at a position where it can capture images including the steel sheet 1 on the exit side of F3 stand 30 and the entry side of F4 stand 40. Camera 84 is located at a position where it can capture images including the steel sheet 1 on the exit side of F4 stand 40 and the entry side of F5 stand 50. Camera 85 is located at a position where it can capture images including the steel sheet 1 on the exit side of F5 stand 50 and the entry side of F6 stand 60. Camera 86 is located at a position where it can capture images including the steel sheet 1 on the exit side of F6 stand 60 and the entry side of F7 stand 70.

These cameras 81, 82, 83, 84, 85, and 86 capture images including the steel plate 1, for example, from directly above the steel plate 1 or from diagonally above, preferably in video format, at intervals shorter than 0.1 seconds, and the data of the captured images is transmitted to the leveling control device 150 via communication line 110.

The leveling control device 150 is a device composed of a computer and other components that control the operation of each piece of equipment within the rolling equipment 200, and has a torque acquisition unit 161, a primary component calculation unit 162, a leveling correction amount calculation unit 163, a leveling amount change unit 164, a meandering amount calculation unit 165, and a memory unit 166.

The torque acquisition unit 161 determines the torque distribution applied in the width direction of the steel sheet 1 between each of the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 from the torque measured by each of the shape meters 91, 92, 93, 94, 95, and 96 installed between the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70. This torque acquisition unit 161 is preferably the entity that executes the torque acquisition process.

In addition, the torque acquisition unit 161 calculates the torque distribution applied in the width direction of the steel plate 1 downstream of the rolling of the final F7 stand 70 from the torque of the steel plate 1 acquired by the shape meter 97 provided downstream of the rolling of the final F7 stand 70.

The meandering amount calculation unit 165 calculates the amount of deviation between the widthwise center of the steel plate 1 and the rolling center between each of F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 from the results measured by each plate position detector installed between F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70.

The plate position detectors that obtain the measurement results used by the meandering amount calculation unit 165 are the above-mentioned cameras 81, 82, 83, 84, 85, and 86, or shape meters 91, 92, 93, 94, 95, 96, and 97.

The primary component calculation unit 162 calculates the tension distribution in the width direction of the steel plate 1 from the torque distribution calculated by the torque acquisition unit 161. It also calculates the primary component when the tension distribution of the steel plate 1 is expressed as a polynomial from the calculated tension distribution. In this case, the primary component calculation unit 162 can correct the torque distribution in the width direction of the steel plate 1 based on the deviation amount (meandering amount ΔYc in Figure 2) calculated by the meandering amount calculation unit 165. This primary component calculation unit 162 preferably performs the primary component calculation process.

The leveling correction amount calculation unit 163 calculates the leveling correction amount for the rolling stands 10, 20, 30, 40, 50, and 60 immediately upstream of the rolling line based on the primary components calculated by the primary component calculation unit 162. It is also desirable that the leveling correction amount calculation unit 163 calculates the leveling correction amount for the F7 stand 70 based on the primary components calculated by the primary component calculation unit 162. This leveling correction amount calculation unit 163 is preferably the entity that executes the leveling correction amount calculation process.

More specifically, the leveling correction amount calculation unit 163 performs leveling correction for the F6 stand 60 using the first-order component of the tension distribution calculated from the torque of the steel plate 1 measured by the shapemeter 96 provided on the delivery side of the F6 stand 60. This process is performed sequentially toward the upstream side of the rolling.

Here, changing the leveling at each stand changes both the first-order components on the entry and exit sides of each stand, so it is desirable to determine the adjustment amount using the first-order component on the exit side of the final F7 stand 70. Therefore, it is desirable to correct the leveling of F7 stand 70 using the first-order component of the tension distribution calculated from the torque of the steel plate 1 measured by the shape meter 97 installed on the exit side of F7 stand 70.

In addition, if leveling is corrected upstream, the effect propagates downstream, so it is desirable to feedback control the leveling amount of each stand so that the plate wedge ratio remains constant, i.e., the first-order component is zero.

Furthermore, when the tail end (finest plate end) of the steel plate 1 reaches the shape meter 94 on the inlet side of F5 stand 50, the shape meter 96 of F7 stand 70 begins to descend vertically downward (starts to move away from the steel plate 1), and from this point on, it is desirable to correct the leveling of F6 stand 60 and F7 stand 70 using the amount of meandering of the steel plate 1 input from the camera 85 in front of F6 stand 60 and the camera 86 in front of F7 stand 70. More specifically, it is desirable to correct the leveling of F6 stand 60 using the amount of off-center between F5 stand 50 and F6 stand 60, and to correct the leveling of F7 stand 70 using the off-center between F6 stand 60 and F7 stand 70.

Furthermore, since the amount of meandering cannot be measured once the tail end of the steel plate 1 passes below the camera 86 in front of the F7 stand 70, it is desirable to switch to lock-on control of the differential load of the F7 stand 70.

Here, the leveling correction amount calculation unit 163 can calculate the leveling correction amount so that the calculated first-order component is within the allowable range.

Figure 2 shows an example of a method for determining the allowable range of a first-order component.

Figure 2 shows the timing when the tail end of steel plate 1 leaves F6 stand 60. As steel plate 1 leaves F6 stand 60, only F7 stand 70 is exerting left and right restraining force on steel plate 1, which may cause steel plate 1 to meander significantly.

Let H be the average thickness of steel plate 1 on the entry side of F7 stand 70, ΔH be the difference in thickness between both ends of steel plate 1 on the entry side, h be the average thickness of steel plate 1 on the exit side of F7 stand 70, and Δh be the difference in thickness between both ends of steel plate 1 on the exit side. The difference between the center of F7 stand 70 in the width direction and the center of steel plate 1 in the width direction, i.e., the amount of meandering of steel plate 1, be ΔYc. The amount of meandering ΔYc can be calculated using the plate rotation angular velocity at the tail end and the plate speed moving in the width direction. Furthermore, these plate rotation angular velocity and plate speed can be calculated using the plate wedge ratio change (Δh/h - ΔH/H). Furthermore, when the tension distribution of steel plate 1 is expressed as a polynomial, the first-order component (elongation differential rate) is correlated with the plate wedge ratio change (Δh/h - ΔH/H), and the leveling amount (difference in rolling reduction) is also correlated with ΔH and Δh, and can be calculated numerically. From the results, by determining the maximum value of the allowable amount of meandering ΔYc (for example, the amount of meandering ΔYc in the F7 stand 70 when the tail end of the steel sheet 1 comes into contact with a side guide (not shown in the drawings)), it is possible to calculate the magnitude of the first-order component of the torque distribution applied in the width direction of the steel sheet 1 on the outlet side of the F7 stand 70 when the allowable amount of meandering ΔYc is at its maximum value.

Therefore, the leveling correction amount calculation unit 163 can calculate the leveling correction amount so that the first-order component calculated by the first-order component calculation unit 162 falls within the allowable range, using the range of the first-order component of the torque distribution that can keep the meandering amount ΔYc within the allowable range as the allowable range.

Based on the leveling correction amount calculated by the leveling correction amount calculation unit 163, the leveling amount change unit 164 changes the leveling amount of the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 in order, starting from the (last-1) stage stand toward the upstream side of the rolling. It is also desirable that the leveling amount change unit 164 also changes the leveling amount of the F7 stand 70 before changing the leveling amount of the (last-1) stage stand. This leveling amount change unit 164 is preferably the entity that executes the leveling amount change process.

The leveling amount change unit 164 outputs control parameter information for the calculated leveling amount to each of the screw-down devices 11, 21, 31, 41, 51, 61, and 71 via the communication line 120, and each of the screw-down devices 11, 21, 31, 41, 51, 61, and 71 operates to realize the input leveling amount.

The memory unit 166 is a memory device of the computer that constitutes the leveling control device 150, and is preferably composed of an SSD or HDD.

The leveling control device 150 controls the operation of each device, and the operation of the torque acquisition unit 161, primary component calculation unit 162, leveling correction amount calculation unit 163, leveling amount change unit 164, meandering amount calculation unit 165, etc. is controlled based on various programs recorded in the memory unit 166.

The control processing of the operations executed by the leveling control device 150 may be integrated into a single program, separated into multiple programs, or a combination of these. Furthermore, some or all of the programs may be implemented using dedicated hardware or may be modularized.

Next, a leveling control method for a hot rolling line in which F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 are arranged, which is preferably performed by the leveling control device 150 according to this embodiment, will be described with reference to Figure 3. Figure 3 is a flowchart showing an example of the flow of correction control of the leveling amount in the leveling control device of this embodiment 1.

As shown in Figure 3, first, the torque of the steel plate 1 at the exit side of F7 stand 70 (final stand) is measured using a shapemeter 97, and the torque acquisition unit 161 of the leveling control device 150 calculates the torque distribution in the width direction of the steel plate 1, and the primary component calculation unit 162 calculates the primary component in the width direction of the steel plate 1 (step S101).

Next, the leveling correction amount calculation unit 163 of the leveling control device 150 calculates the leveling correction amount of the F7 stand 70 taking into account the first-order component obtained in step S101, and the leveling amount change unit 164 changes the leveling amount (step S102).

Then, the first-order component of the tension distribution of the steel plate 1 between the F6 stand 60 and the F7 stand 70 is determined in the same way as in the case of the exit side of the F7 stand 70 (final stand) (step S103).

Then, the leveling correction amount calculation unit 163 calculates the leveling correction amount of the F6 stand 60 taking into account the first-order component obtained in step S103, and the leveling amount change unit 164 changes the leveling amount (step S104).

Processing similar to steps S101 and S102, or steps S103 and S104, is also performed on F5 stand 50, F4 stand 40, F3 stand 30, F2 stand 20, and F1 stand 10 (corresponding to steps S105, S106, S107, S108, S109, S110, S111, S112, S113, and S114, respectively (calculating the leveling correction amount for F1 taking into account the first-order component, and changing the leveling)).

Here, if leveling is corrected on the upstream side, the effect will be propagated to the downstream side, so it is desirable to calculate the leveling correction amount for F7 stand 70 by assuming the plate wedge ratio to be constant for the leveling correction amount for F6 stand 60 (step S121) and reflect this in the processing in step S102.

The processing of step S121 is the same for the F5 stand and others, and the correction amounts for F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, and F6 stand 60 are calculated with the plate wedge ratio kept constant, and the leveling correction amount for each stand is calculated (corresponding to steps S122, S123, S124, S125, and S126), which can be reflected in the processing of step S102, etc.

In order to avoid constant looping due to the above-mentioned step S121, etc., it is desirable to record the number of times step S121 is executed, and stop the execution of steps S121, ..., S126 when it has been executed a predetermined number of times, or stop the execution after a certain time has elapsed since the first execution, or stop the execution of the process when the amount of correction in steps S121, ..., S126 falls below a specified value.

Then, it is determined whether the primary component of the tension distribution of the steel plate 1 at each outlet of all stands satisfies the allowable value (step S130), and if it is determined that it does, the processing is completed (the control parameter information of the determined leveling amount is output to each screw down device 11, 21, 31, 41, 51, 61, 71). On the other hand, if it is determined that it does not satisfy the allowable value at any one stand, the processing returns to step S101, and the processing of determining the control parameter of the leveling amount continues until the allowable value is satisfied at the outlet of all stands.

It is also desirable to continuously perform the process shown in Figure 3 during rolling. In other words, it is desirable to perform the process again from the beginning after the process is completed.

Of the above steps, steps S101 and S103 correspond to the torque acquisition process and the first-order component calculation process, and steps S102, S104, S114, and S126 correspond to the leveling correction amount calculation process and the leveling amount change process.

Next, we will explain the effects of this embodiment.

The leveling control device 150 in the rolling equipment 200 of the above-described embodiment 1 of the present invention calculates the torque amount applied in the width direction of the steel sheet 1 between each of the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 from the torque measured by each of the shape meters 91, 92, 93, 94, 95, and 96 installed between the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70. a first-order component calculation unit 162 that calculates the tension distribution in the width direction from the calculated torque distribution and calculates the first-order component when the tension distribution of the steel plate 1 is expressed as a polynomial from the tension distribution; a leveling correction amount calculation unit 163 that calculates the leveling correction amounts for the rolling stands 10, 20, 30, 40, 50, and 60 immediately preceding the upstream rolling side based on the calculated first-order components; and a leveling amount change unit 164 that changes the leveling amounts in order from stand F6 60 toward the upstream rolling side based on the calculated leveling correction amounts.

This makes it possible to calculate the appropriate leveling amount taking into account the type of steel plate 1 width and measurement errors, thereby improving the accuracy of roll reduction control compared to conventional methods.

In addition, the leveling correction amount calculation unit 163 calculates the leveling correction amount so that the calculated primary component is within the allowable range, thereby reducing the primary component and making the plate wedge ratio closer to constant. This results in the effect of allowing rolling while maintaining the plate wedge and reducing the meandering of the steel plate 1, thereby achieving more stable rolling.

Furthermore, since changing the leveling changes the primary components on both the entry and exit sides of each stand, the torque acquisition unit 161 determines the torque distribution applied in the width direction of the steel plate 1 downstream of the rolling of the F7 stand 70 from the torque of the steel plate 1 acquired by the shape meter 97 provided downstream of the rolling of the F7 stand 70, and the leveling amount change unit 164 also changes the leveling amount of the F7 stand 70 before the (final -1) stage stand, thereby further improving the accuracy of the roll down control.

In addition, since it is difficult to accurately measure the left-right tension deviation when the plate is deviated from the rolling center, the system further includes a meandering amount calculation unit 165 that calculates the amount of deviation between the widthwise center of the steel plate 1 and the rolling center between F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 based on the results of measurements by the plate position detectors installed at each of the F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70. The primary component calculation unit 162 corrects the torque distribution in the widthwise direction based on the amount of deviation calculated by the meandering amount calculation unit 165, thereby correcting the torque difference by the amount of deviation and more accurately calculating the primary component. This further improves the accuracy of roll gap control.

Example 2
A leveling control device, a rolling mill equipped with the same, and a leveling control method according to a second embodiment of the present invention will be described with reference to Figures 4 and 5. Figure 4 is a schematic diagram showing the configuration of a rolling mill equipped with the leveling control device of the second embodiment, and Figure 5 is a flowchart showing an example of the flow of correction control of the leveling amount.

The rolling equipment 200A of this embodiment shown in Figure 4 is equipped with a plate wedge amount measuring device 98 that measures the thickness distribution in the width direction of the steel plate 1, instead of the shape meter 97 provided on the outlet side of the F7 stand 70 in the rolling equipment 200 of the above-mentioned embodiment 1. Note that the plate wedge amount measuring device 98 may be a plate thickness gauge or a profile meter, as long as it is a measuring device that can measure data that can be used to calculate the plate wedge amount.

In addition to the leveling control device 150 of Example 1, the leveling control device 150A further includes a plate wedge amount acquisition unit 167A.

The plate wedge amount acquisition unit 167A calculates the plate wedge amount of the steel plate 1 downstream of the rolling of the F7 stand 70 from the widthwise plate thickness distribution measured by the plate wedge amount measuring device 98 installed downstream of the rolling of the F7 stand 70.

In addition, the leveling correction amount calculation unit 163A calculates the leveling correction amount for the F7 stand 70 based on the plate wedge amount calculated by the plate wedge amount acquisition unit 167A, and the leveling amount change unit 164A also changes the leveling amount for the F7 stand 70 before the (final -1) stage stand.

When rolling at F7 stand 70 of rolling equipment 200A, the plate wedge transfer rate is considered to be nearly 0, and the plate wedge (plate wedge ratio) before rolling is considered to be inherited as is. After rolling, the leveling correction amount for F7 stand 70 is calculated from the actual measured value of the plate wedge on the outlet side, and the oil column difference between the drive side and work side screw-down device 71 is adjusted.

Next, the leveling control method, which is preferably performed by the leveling control device 150A of this embodiment, will be explained with reference to Figure 5.

As shown in Figure 5, first, the plate wedge of the steel plate 1 on the outlet side of the F7 stand 70 is measured using the plate wedge amount measuring device 98 and the plate wedge amount acquisition unit 167A of the leveling control device 150A (step S201).

Next, the leveling correction amount calculation unit 163A of the leveling control device 150A calculates the leveling correction amount for the F7 stand 70 taking into account the plate wedge determined in step S101, and the leveling amount change unit 164 changes the leveling amount (step S202). Any known method may be used to calculate the leveling correction amount from the determined plate wedge.

The subsequent processing of steps S203 to S230 is the same as the processing of steps S103 to S130 in Figure 3 above, and details will be omitted.

The other configurations and operations are approximately the same as those of the leveling control device, rolling equipment equipped with it, and leveling control method of Example 1 described above, and details will be omitted.

The leveling control device of Example 2 of the present invention, the rolling equipment equipped therewith, and the leveling control method also achieve substantially the same effects as the leveling control device of Example 1 described above, the rolling equipment equipped therewith, and the leveling control method.

The system further includes a plate wedge amount acquisition unit 167A that determines the plate wedge amount of the steel plate 1 downstream of the rolling of the F7 stand 70 from the widthwise plate thickness distribution measured by a plate wedge amount measuring device 98 provided downstream of the rolling of the F7 stand 70. The leveling correction amount calculation unit 163A determines the leveling correction amount of the F7 stand 70 based on the plate wedge amount determined by the plate wedge amount acquisition unit 167A, and the leveling amount change unit 164A also changes the leveling amount of the F7 stand 70 before the (final -1) stage stand, thereby further improving the accuracy of the roll-down control even when shape data is not available at the exit side of the F7 stand 70.

Example 3
A leveling control device, a rolling mill equipped with the same, and a leveling control method according to a third embodiment of the present invention will be described with reference to Figures 6 and 7. Figure 6 is a schematic diagram showing the configuration of a rolling mill equipped with the leveling control device of this third embodiment, and Figure 7 is a flowchart showing an example of the flow of correction control of the leveling amount.

The rolling equipment 200B of this embodiment shown in Figure 6 does not have the shape meter 97 in the rolling equipment 200 of Example 1 or the plate wedge amount measuring device 98 in the rolling equipment 200A of Example 2, and is configured to estimate the plate wedge amount and tension distribution of the steel plate 1 at the outlet of the final stage, F7 stand 70, using calculated values when data cannot be obtained.The leveling control device 150B further has a plate wedge amount calculation unit 168B that calculates the plate wedge amount of the steel plate 1 on the upstream side of F7 stand 70 based on the rolling load and leveling amount from the upstream side of rolling to the (final - 1) stage stand among F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70.

In addition, the leveling correction amount calculation unit 163B of the leveling control device 150B calculates the leveling correction amount for the F7 stand 70 based on the plate wedge amount calculated by the plate wedge amount calculation unit 168B, and the leveling amount change unit 164B also changes the leveling amount for the F7 stand 70 before the (final - 1)th stand.

In rolling facilities with multiple stands, in the front-stage F1 stand 10 and F2 stand 20, the strip wedge is formed in a manner that roughly follows leveling, i.e., transcription prevails. In contrast, in the rear-stage F3 stand 30 and subsequent stands, in order to avoid large deformations in the shape, the wedge (ratio) that enters the rolling stand is also seen on the exit side, i.e., inheritance prevails.

Therefore, based on this phenomenon, it is possible to estimate the plate wedge at the exit of each stand. Therefore, once the plate wedge at the entrance of the final stand, F7 stand 70, can be calculated, if the leveling of F7 stand 70 is changed based on the calculated plate wedge amount at the exit of F6 stand 60, this will have an effect on the upstream side, changing the tension of shape meters 91, 92, 93, 94, 95, and 96. Thereafter, as in Examples 1 and 2, it is possible to change and control the leveling amount upstream.

However, since changing the leveling upstream also affects the calculated value of the plate wedge on the inlet side of F7 stand 70, it is desirable for each stand to control its own leveling amount and calculate the plate wedge independently.For example, the calculation of the plate wedge in steps S301 to S306 is performed continuously, and the leveling change processing in steps S307 to S330 is performed between the start and end.

Next, the leveling control method, which is preferably performed by the leveling control device 150B of this embodiment, will be explained with reference to Figure 7.

As shown in Figure 7, first, the plate wedge amount calculation unit 168B of the leveling control device 150B calculates the plate wedge on the outlet side of F1 stand 10 using the measured rolling load P at F1 stand 10, the predicted roll profile value Cw, and the measured leveling ΔS (step S301).

Next, in the plate wedge amount calculation unit 168B, the plate wedge at the exit side of F2 stand 20 is calculated using the calculated plate wedge value at the exit side of F1 stand 10 obtained in the previous step S301, the measured rolling load P of F2 stand 20, the predicted roll profile value Cw, and the measured leveling ΔS (step S302).

Processing similar to steps S301 and S302 is also performed for F3 stand 30, F4 stand 40, F5 stand 50, and F6 stand 60 (corresponding to steps S303, S304, S305, and S306, respectively).

Thereafter, as described above, since the plate wedge transfer rate is considered to be approximately 0 during rolling at F7 stand 70, the leveling correction amount calculation unit 163B of the leveling control device 150B calculates the leveling correction amount for F7 stand 70 taking into account the plate wedge (plate wedge ratio) at the outlet side of F6 stand 60 calculated in the step corresponding to step S306 before rolling, and the leveling amount change unit 164B changes the leveling amount (step S307).

The subsequent steps from step S308 onwards are essentially the same as the steps S103 to S130 in Figure 3 above, and so details will be omitted. The difference is that if it is determined in step S330 that any one of the stands is not satisfied, the process returns to step S307, and the process of determining the leveling amount control parameters continues until all stands are satisfied.

The other configurations and operations are approximately the same as those of the leveling control device, rolling equipment equipped with it, and leveling control method of Example 1 described above, and details will be omitted.

The leveling control device of Example 3 of the present invention, the rolling equipment equipped with the same, and the leveling control method also achieve effects substantially similar to those of the leveling control device of Example 1, the rolling equipment equipped with the same, and the leveling control method described above.

The system further includes a plate wedge amount calculation unit 168B that calculates the plate wedge amount of the steel plate 1 on the upstream side of rolling of F7 stand 70 based on the rolling load and leveling amount of F1 stand 10, F2 stand 20, F3 stand 30, F4 stand 40, F5 stand 50, F6 stand 60, and F7 stand 70 from the upstream side of rolling to the (final - 1)th stand.The leveling correction amount calculation unit 163B calculates the leveling correction amount of F7 stand 70 based on the plate wedge amount calculated by the plate wedge amount calculation unit 168B, and the leveling amount change unit 164B also changes the leveling amount of F7 stand 70 before the (final - 1)th stand, thereby further improving the accuracy of roll down control even when various data is not available at the outlet side of F7 stand 70.

<Others>
It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications. The above-described embodiment has been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

It is also possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace part of the configuration of each embodiment with the configuration of another embodiment.

1...Steel plate 10...F1 stand 11, 21, 31, 41, 51, 61, 71...Screwing down device 12, 22, 32, 42, 52, 62, 72...Load detector 20...F2 stand 30...F3 stand 40...F4 stand 50...F5 stand 60...F6 stand 70...F7 stand 81, 82, 83, 84, 85, 86...Cameras 91, 92, 93, 94, 95, 96, 97...Shape meter 98...Plate web Wedge amount measuring devices 110, 120... communication lines 150, 150A, 150B... leveling control device 161... torque acquisition unit 162... primary component calculation unit 163, 163A, 163B... leveling correction amount calculation unit 164, 164A, 164B... leveling amount change unit 165... meandering amount calculation unit 166... storage unit 167A... plate wedge amount acquisition unit 168B... plate wedge amount calculation unit 200, 200A, 200B... rolling equipment

Claims (5)

A leveling control device for a hot rolling line in which a plurality of rolling stands are arranged,
a torque acquisition unit that determines a torque distribution applied in the width direction of the steel sheet between each of the plurality of rolling stands from torques measured by each shapemeter provided between the plurality of rolling stands;
a first-order component calculation unit that calculates a tension distribution in the width direction from the calculated torque distribution, and calculates a first-order component when the tension distribution of the steel sheet is expressed as a polynomial from the tension distribution;
a leveling correction amount calculation unit that calculates the leveling correction amounts of the rolling stands provided on the rolling upstream side among the plurality of rolling stands, in order from the rolling stand immediately upstream of the final stage toward the rolling upstream side, excluding the final stage rolling stand, based on the calculated first-order component;
a leveling amount changing unit that changes the leveling amount in sequence from the rolling stand immediately upstream of the final stage among the plurality of rolling stands, excluding the final rolling stand, toward the rolling upstream side, based on the leveling correction amount found for each stage ,
the torque acquisition unit determines a torque distribution applied in a width direction of the steel plate on the rolling downstream side of a final stand from the torque of the steel plate acquired by a shape meter provided on the rolling downstream side of a final stand among the plurality of rolling stands,
The leveling control device , wherein the leveling amount changing unit also changes the leveling amount of the final stand before the rolling stand immediately upstream of the final stage . 2. The leveling control device according to claim 1,
The leveling control device, wherein the leveling correction amount calculation unit calculates the leveling correction amount so that the calculated first-order component falls within an allowable range. 3. The leveling control device according to claim 1 ,
a meandering amount calculation unit that calculates a deviation amount between a center of the steel plate in the width direction and a rolling center between each of the plurality of rolling stands from results of measurement by each plate position detector provided between the plurality of rolling stands,
The leveling control device, wherein the primary component calculation unit corrects the torque distribution in the width direction based on the deviation amount calculated by the meandering amount calculation unit. A leveling control device according to any one of claims 1 to 3 ;
a plurality of rolling stands for rolling the steel plate;
a shape meter provided between each of the plurality of rolling stands. A leveling control method for a hot rolling line in which a plurality of rolling stands are arranged, comprising the steps of:
a torque obtaining step of obtaining a torque distribution applied in the width direction of the steel sheet between each of the plurality of rolling stands from torques measured by each shapemeter provided between the plurality of rolling stands;
a first-order component calculation step of calculating a tension distribution in the width direction from the calculated torque distribution, and calculating a first-order component when the tension distribution of the steel sheet is expressed as a polynomial from the tension distribution;
a leveling correction amount calculation step of calculating the leveling correction amounts of the rolling stands provided on the rolling upstream side among the plurality of rolling stands, in order from the rolling stand immediately upstream of the final stage toward the rolling upstream side, excluding the final stage rolling stand, based on the calculated first-order component;
a leveling amount changing step of changing the leveling amount in sequence from the rolling stand immediately upstream of the final stage among the plurality of rolling stands, excluding the final rolling stand, toward the rolling upstream side, based on the leveling correction amount determined for each stage ,
In the torque obtaining step, a torque distribution applied in the width direction of the steel plate on the rolling downstream side of the final stand is obtained from the torque of the steel plate obtained by a shape meter provided on the rolling downstream side of the final stand among the plurality of rolling stands,
the leveling amount changing step also changes the leveling amount of the final stand before the rolling stand immediately upstream of the final stage .