JP7200859B2 - Rolling shape control device - Google Patents

Description

The present application relates to a rolling shape control device.

In shape control of a rolled material, a plurality of measurement zones are divided in the lengthwise direction of the sensor roll of the shape meter. During rolling, the actual shape of each of the plurality of measurement zones is measured by a shape meter. A shape deviation is calculated as a difference between the measured actual shape of each measurement zone and a preset target shape of each measurement zone. The manipulated variable of the shape control actuator is obtained so that the shape deviation is minimized.

Types of shape control actuators include "low-order shape control actuators" capable of correcting low-order shape deviations and "high-order shape control actuators" capable of correcting high-order shape deviations. . High-order shape control actuators can correct relatively higher-order shape deviations than low-order shape control actuators.

Examples of low-order shape control actuators include roll benders and levelers. A roll bender is an actuator that bends a roll so as to bend the central axis of the roll. Leveling is the actuator that manipulates the left and right roll gap differential.

High-order shape control actuators include, for example, spot coolant equipment. The spot coolant system is designed to individually control the flow rate of multiple coolant sprays installed in the width direction of the strip. Spot coolant installations can take advantage of local work roll thermal expansion changes to correct for higher order shape deviations.

A technique disclosed in Japanese Patent Application Laid-Open No. 1-306008 is known. In the technique disclosed in the publication, using the shape influence coefficient of the actuator in each shape meter measurement zone, the manipulated variables of the roll bender and leveling are calculated so as to minimize the shape deviation based on the method of least squares.

However, with the shape control technology disclosed in Japanese Patent Application Laid-Open No. 1-306008, it is difficult to correct a specific type of shape defect such as a locally stretched shape at the ends of the rolled material. This particular type of shape defect is caused by the low thermal expansion of the work rolls at the ends of the strip. At the center of the rolled strip, the work roll thermally expands due to the heat generated by the rolling strip. small swelling. As a result, the roll gap at the ends of the rolled material becomes larger than the inside, and the tension is locally increased.

When the particular type of shape defect described above occurs, not only is the strip edge stretched, but several zones inside the strip edge are stretched beyond the desired shape. This is the result of controlling complex high-order shape defects at the ends of the rolled material by roll bending and leveling. With the shape control technology disclosed in Japanese Patent Application Laid-Open No. 1-306008, even if the spot coolant flow rate is changed up to the upper and lower limit of the equipment, the above specific type of shape defect cannot be completely corrected. When the above specific type of shape defect occurs, sheet breakage due to high tension at the ends of the rolled material and quarter elongation inside the ends lead to a decrease in yield and product quality.

For this reason, shape control has been developed in the past aimed at improving the specific types of shape defects mentioned above. For example, in Japanese Patent No. 4449789, a target shape (first target shape) for calculating the operation amount of a roll bender, etc., and a target shape (second target shape) for calculating the operation amount of the spot coolant equipment are set to different shapes from each other. According to this method, by intentionally increasing or decreasing the coolant spray flow rate at the point where the target shape is changed to create a shape deviation, the tension of the plate edge can be effectively improved when combined with a roll bender. can do.

JP-A-1-306008 Japanese Patent No. 4449789

In the technique disclosed in Japanese Patent No. 4449789, different target shapes are set according to the types of actuators, thereby effectively reducing shape defects caused by stretched ends of the rolled material. However, the technique disclosed in the above publication has a problem that it is actually difficult to adjust the second target shape set for the spot coolant facility.

The shape of the rolled material is ultimately determined not only by the influence of the spot coolant equipment, but also by the combination of the influence of the spot coolant equipment and the influence of the roll bender and leveling. How to set the second target shape for the spot coolant facility cannot be known unless the second target shape is actually changed and the control result is confirmed. Therefore, there is an inconvenience that the operator needs time and effort for trial and error.

In addition, with the technology disclosed in the above publication, it is difficult to apply only one type of target shape to all types of rolled material. Therefore, it is necessary to make adjustments according to individual conditions including the properties, thickness and width of the rolled material. Whether or not the degree of adjustment is necessary when creating a new target shape must also be determined with the knowledge of an expert. There is a problem that such work requires skill of the coordinator.

The present application has been made to solve the above-described problems, and provides a rolling shape control device capable of improving the shape defects of the ends of the rolled material without depending on the skill level of the operator. .

The first rolling shape control device according to the present application is
shape deviation calculation means for calculating a shape deviation between the actual shape and the target shape of the rolled material along the strip width direction;
actuator operation amount calculation means for calculating an actuator operation amount for operating a roll actuator that changes at least one of a roll position and a roll shape;
a first coolant manipulated variable calculation means for calculating a first manipulated variable for manipulating the spray injection of the spot coolant equipment according to the magnitude of the shape deviation;
Based on an evaluation function that predetermines the relationship between the shape deviation and the amount of operation of each of the roll actuator and the spot coolant equipment, the spot coolant is adjusted so that the shape deviation is equal to or less than a predetermined deviation in the evaluation function. a second coolant manipulated variable calculation means for calculating a second manipulated variable for manipulating the spray injection of the equipment;
A shape difference, which is a difference between a first actual shape of an end portion of the rolled material along the width direction of the strip and a second actual shape of a portion of the rolled material inside the end portion, is calculated, and the shape difference is calculated. and a predetermined threshold value to determine whether or not the end of the rolled material has a predetermined stretched shape, and if the end of the rolled material does not have the stretched shape selects the first manipulated variable and selects the second manipulated variable when the end of the rolled material is in the stretched shape;
a coolant flow rate control device that controls the spot coolant facility based on the manipulated variable selected by the plate end shape monitoring means from the first manipulated variable or the second manipulated variable;
Prepare.

The "roll actuator" may be one or more actuators selected from the group consisting of work roll benders, leveling, intermediate roll benders, roll shifts and variable crown rolls.

Each of the first manipulated variable and the second manipulated variable for manipulating the spray injection of the spot coolant facility may include at least one of spray flow rate, spray on-off, and coolant flow rate.

According to the first rolling shape control device, it is possible to switch the calculation contents of the spot coolant operation amount depending on whether or not the end shape of the rolled material has become a taut shape. When a tense shape occurs, a second manipulated variable for obtaining a high-order shape deviation improvement effect calculated by the evaluation function is used. Otherwise, the first manipulated variable corresponding to the shape deviation is used. Since the second manipulated variable calculated by the evaluation function is automatically used as necessary, it eliminates shape defects caused by local tension at the ends of the rolled material without depending on the skill level of the operator. can be suppressed.

It is a figure which shows the structure of the rolling shape control apparatus concerning embodiment. 7 is a graph for explaining a technique for determining whether or not there is a tension shape in the rolled shape control device according to the embodiment; It is a figure which shows the structure of the rolling shape control apparatus concerning the modification of embodiment. It is a figure which shows the structure of the rolling shape control apparatus concerning the reference example of embodiment. It is a figure which shows the structure of the rolling shape control apparatus concerning the reference example of embodiment.

(System configuration)
FIG. 1 is a diagram showing the configuration of a rolling shape control device 5 according to an embodiment. As an example, the rolling mill according to the embodiment is assumed to be a four-high cold rolling mill. FIG. 1 also shows a four-high cold rolling mill system 100 in which the rolling shape control device 5 is mounted.

A four-high cold rolling mill system 100 includes a rolling mill 1 for rolling a strip 2, a shape meter 4, a rolling shape control device 5, a setting device 7, a roll actuator 12, and a spot coolant sprayer 15a. A coolant facility 15 is provided.

A rolling mill 1 rolls a strip 2 in a rolling direction 3 . The flatness of the rolled material 2 rolled by the rolling mill 1 is measured by a shape meter 4 installed on the delivery side of the rolling mill. Specifically, a plurality of measurement zones are divided in the sensor roll body length direction of the shape meter 4 . During rolling, the actual shape of each of the plurality of measurement zones is measured by the shape meter 4 . The flatness of the rolled material 2 is measured by measuring the shape for each shape measurement zone of the sensor roll divided in the strip width direction of the shape meter 4 .

The flatness measured by the shape meter 4 is transmitted to the rolling shape control device 5 as an actual shape. The target shape of each shape measurement zone is preset in the setting device 7 .

The roll actuator 12 changes at least one of roll position and roll shape, and in the embodiment, it is assumed to be a work roll bender and leveling.

Here, the actuator used to control the shape of the rolled material 2 will be described in detail. The shape control actuators include a "low-order shape control actuator" capable of correcting low-order shape deviations and a "high-order shape control actuator" capable of correcting high-order shape deviations. The terms "lower order" and "higher order" mean whether the polynomial approximation of the shape deviation in the strip width direction of the rolled material 2 is higher or lower than a predetermined order (for example, the fourth order). High-order shape control actuators can correct relatively higher-order shape deviations than low-order shape control actuators.

The low-order shape control actuator can correct a low-order shape deviation up to, for example, the fourth order when the shape deviation is polynomial-approximated in the strip width direction of the rolled material 2 . The low-order shape control actuator is, for example, a roll actuator 12 that controls at least one of the roll position and the roll shape.

Examples of roll actuators 12 include roll benders and levelers. A roll bender is an actuator that bends a roll so as to bend the central axis of the roll. Leveling is the actuator that manipulates the left and right roll gap differential. Other examples of roll actuators 12 include intermediate roll benders, roll shifts and variable crown rolls.

Embodiments illustrate roll actuators 12 that include work roll benders and levelers. In alternate embodiments, roll actuator 12 is modified to be one or more actuators selected from any of the group consisting of work roll benders, leveling, intermediate roll benders, roll shifts, and variable crown rolls. may

In the embodiment, a spot coolant facility 15 is used as an actuator for high-order shape control. The spot coolant equipment 15 individually controls the flow rate of a plurality of spot coolant sprays 15a installed in the strip width direction of the rolled material 2 . The spot coolant facility 15 can take advantage of local work roll thermal expansion changes to correct for higher order shape deviations.

The operation amount of the spot coolant equipment 15 is a control amount for operating the spray injection of the spot coolant spray 15a. The amount of operation of the spot coolant facility 15 has several variations depending on the specific configuration of the spot coolant facility 15 .

For example, as the first spot coolant facility 15, one that can change the spray flow rate of the spot coolant spray 15a in multiple steps or continuously may be used. In this facility, the spray flow rate of the spot coolant spray 15a may be finely increased or decreased according to the shape deviation. The manipulated variable of the spot coolant equipment 15 in this case is the spray flow rate.

The second spot coolant facility 15 may be a spot coolant facility 15 in which the spot coolant spray 15a can only be selectively switched ON/OFF. In this case, ON/OFF of the spot coolant spray 15a may be switched depending on whether the shape deviation in the vicinity of each of the plurality of spot coolant sprays 15a exceeds a predetermined threshold value. The operation amount of the spot coolant facility 15 in this case is the ON/OFF of the spot coolant spray 15a.

Alternatively, in the second spot coolant facility 15 described above, ON/OFF control may be performed according to the coolant flow rate (%). The coolant flow rate (%) is a value obtained by multiplying 100 by a preset ratio (τ _ON /T _CL ) between the coolant control period (T _CL ) and the ON time (τ _on ). The manipulated variable of the spot coolant equipment 15 in this case is also the "on time ratio" of the spot coolant spray 15a. The spot coolant spray 15a may be controlled by so-called duty control such that fine spray injection is repeated within a minute period. In this case, the on-time ratio corresponds to the duty-on ratio (%).

As described above, in the embodiment, the rolling mill using the roll actuator 12 and the spot coolant equipment 15 as the shape control actuators will be described. The operation amount of each of the roll actuator 12 (that is, roll bender, leveling) and the spot coolant facility 15 is calculated for each constant control cycle. Thereby, the shape deviation is suppressed over the entire length of the rolled material 2 .

(Configuration of rolling shape control device)
As shown in FIG. 1, the rolling shape control device 5 includes a shape deviation calculation means 6, an actuator operation amount calculation means 8, a first coolant operation amount calculation means 9, a second coolant operation amount calculation means 10, a roll It includes an actuator control device 11 that controls the actuator 12 , plate edge shape monitoring means 13 , and a spot coolant flow rate control device 14 .

The shape deviation calculating means 6 calculates the shape deviation between the actual shape and the target shape of the rolled material 2 along the strip width direction. The shape deviation calculating means 6 calculates the shape deviation, which is the difference between the actual shape from the shape meter 4 and the target shape from the setting device 7, for each shape measurement zone at each predetermined control cycle.

The shape deviation calculated by the shape deviation calculation means 6 is transmitted to the actuator operation amount calculation means 8 , the first coolant operation amount calculation means 9 and the second coolant operation amount calculation means 10 .

Actuator operation amount calculation means 8 calculates an actuator operation amount for operating the roll actuator 12 . Specifically, the actuator operation amount calculation means 8 calculates the actuator operation amount of the roll actuator 12 (that is, the work roll bender and leveling) so that the shape deviation in each shape measurement zone received from the shape deviation calculation means 6 is minimized. to calculate

As an example of specific control contents of the actuator manipulated variable calculation means 8, the technique disclosed in Japanese Patent Application Laid-Open No. 1-306008 may be used. As described in the publication, the operation amount of the roll actuator 12 is calculated so as to minimize the shape deviation based on the least squares method using the shape influence coefficient of the actuator in each shape meter measurement zone. good too.

Further, as another example of the actuator operation amount calculating means 8, a function may be created by omitting elements related to the spot coolant from formulas (1) to (5) described later. The actuator operation amount calculation means 8 may calculate the operation amount of the roll actuator 12 according to this function. Specific control contents of the actuator manipulated variable calculating means 8 are not novel matters since various known techniques can be used, so detailed description thereof will be omitted.

The actuator operation amount calculated by the actuator operation amount calculation means 8 is transmitted to the actuator control device 11 . The actuator control device 11 controls the roll actuators 12 of the rolling mill 1 based on the transmitted manipulated variables.

The first coolant manipulated variable calculation means 9 calculates the manipulated variable of the spot coolant equipment 15 according to the magnitude of the shape deviation.

The second coolant operation amount calculation means 10 performs a second operation for operating the spot coolant equipment 15 based on an evaluation function that predetermines the relationship between the shape deviation and the respective operation amounts of the roll actuator 12 and the spot coolant equipment 15. Calculate quantity. The second coolant manipulated variable calculation means 10 is, so to speak, spot coolant manipulated variable calculation means at the time of shape defect.

Hereinafter, for the sake of distinction, the manipulated variable calculated by the first coolant manipulated variable calculation means 9 is also referred to as the "first manipulated variable" for convenience, and the manipulated variable calculated by the second coolant manipulated variable calculation means 10 is referred to as the "second It is also called "two-manipulated variable".

The strip end shape monitoring means 13 detects a shape difference, which is the difference between the first actual shape of the end portion of the rolled material 2 along the strip width direction and the second actual shape of the portion inside the end portion of the rolled material 2. Calculate The strip end shape monitoring means 13 determines whether or not the end portion of the rolled material 2 has a predetermined stretched shape based on a comparison between the shape difference and a predetermined threshold value. Specifically, when the shape difference is larger than the threshold, it is determined that the end portion of the rolled material 2 has a stretched shape. The strip edge shape monitoring means 13 selects the first manipulated variable when the edge of the rolled material 2 is not in the taut shape. The strip edge shape monitoring means 13 selects the second manipulated variable when the edge of the rolled material 2 is in a stretched shape.

The spot coolant flow control device 14 controls the spot coolant equipment 15 based on the manipulated variable selected by the plate end shape monitoring means 13 from among the first manipulated variable and the second manipulated variable.

(Calculation method of operation amount in spot coolant equipment)
Next, the operation amount of the spot coolant equipment 15 according to the embodiment will be specifically described. In the embodiment, the first coolant operation amount calculation means 9 calculates the first operation amount of the spot coolant equipment 15 , and the second coolant operation amount calculation means 10 calculates the second operation amount of the spot coolant equipment 15 .

The first coolant operation amount calculation means 9 according to the embodiment calculates the first operation amount of the spot coolant equipment 15 according to the magnitude of the shape deviation of each shape measurement zone received from the shape deviation calculation means 6 . The calculated first manipulated variable is transmitted to the plate end shape monitoring means 13 . The specific control content of the first coolant manipulated variable calculation means 9 can use already known various techniques, and is not a new matter, so detailed description will be omitted.

The second coolant manipulated variable calculation means 10 according to the embodiment calculates the second manipulated variable so that the shape deviation becomes the minimum value in the evaluation function. However, as a modification, the second manipulated variable may be calculated so that the shape deviation in the evaluation function is equal to or less than a predetermined deviation. This predetermined deviation is set so that the quality of the shape deviation of the rolled material falls within the allowable range.

Specifically, the second coolant operation amount calculation means 10 according to the embodiment uses the shape deviation of each shape measurement zone received from the shape deviation calculation means 6, and the evaluation represented by the following formula (1) A second manipulated variable of the spot coolant equipment 15 is calculated for each control cycle so that the function J is minimized. This is for the purpose of improving the shape defect in which the shape of the ends of the rolled material is locally stretched. The second manipulated variable calculated here is transmitted to the plate end shape monitoring means 13 .

Here, the meanings of the symbols in each formula are as follows. Add the units in parentheses. N is the number [-] of spot coolant sprays 15a. j is the identification number [-] of the spot coolant spray 15a.

i is the measurement zone number [-] of the shape meter 4; _nS is the first zone number [-] of the measurement zones covered by the plate of the shape meter 4; n _E is the last zone number [-] of the measurement zones covered by the plate of the shape meter 4; ε _j is the shape deviation [I-unit]. α _i ^SC is a weighting factor [-] when calculating the amount of operation of the spot coolant.

∂β _i /∂P _WRB is the shape influence factor of the work roll bender [I-unit/(kN/chock)]. ∂β _i /∂S _LVL is the shape influence factor of leveling [I-unit/mm]. ∂β _i /∂L _j is the shape influence factor [I-unit/%] of the spot coolant equipment 15 .

ΔP _WRB ^SC is the work roll bender operation amount [kN/chock] when calculating the second operation amount of the spot coolant equipment 15 . ΔS _LVL ^SC is the leveling manipulated variable [mm] when calculating the second manipulated variable of the spot coolant equipment 15 .

ΔL _j is the second operation amount [%] of the spot coolant facility 15 . As described above, the second operation amount of the spot coolant equipment 15 is the spray flow rate of the spot coolant spray 15a, the on/off of the spot coolant spray 15a (that is, flow rate 0% or 100%), and the coolant flow rate of the spot coolant spray 15a ( ON time ratio) and at least one of Therefore, ΔL _j shall represent at least one of these flow parameters.

P is the rolling load [kN]. B is the plate width [mm] of the rolled material. h is the product plate thickness [mm]. _lj is the position [mm] of the spot coolant spray 15a in the spot coolant equipment 15 from the center of the mill. L _j ^ACT is the actual flow rate [%] of the spot coolant spray 15 a in the spot coolant facility 15 .

The shape influence coefficient is a model of the amount of change in shape when the actuator is operated. The shape influence factor is adjusted in advance by simulation or experiment.

Equation (1) is the evaluation function J based on the method of least squares. According to equation (1), the second manipulated variable of the roll actuator 12 and each spot coolant installation 15 that minimizes the shape deviation in each shape measurement zone is calculated using the shape influence coefficient.

The amount of shape correction when operating the spot coolant facility 15 corresponds to Equation (2). A second manipulated variable of each spot coolant installation 15 arranged in the strip width direction is calculated individually.

Here, in the spot coolant control applied to the first coolant manipulated variable calculation means 9, according to the first manipulated variable, the spray is turned ON/OFF according to the magnitude of the shape deviation in the vicinity of each shape measurement zone, or the spray A change in flow rate is made. In this case, for example, if there is a specific measurement zone in which the actual shape is longer than the target shape, the spot coolant spray 15a of the specific measurement zone is turned on or the flow rate is increased.

In contrast, when the roll actuator 12 is taken into account in the manipulated variable calculation of the spot coolant installation 15 based on equations (3) and (4), it does not necessarily turn on or increase the flow rate. . Using the evaluation function J, a second manipulated variable of the spot coolant installation 15 that minimizes the shape deviation when the spot coolant installation 15 and the roll actuator 12 are combined is calculated.

In addition, in the embodiment, if it is desired to eliminate the shape deviation at the end portion of the rolled material 2 with priority, the weight of the measurement zone corresponding to the end portion of the rolled material 2 may be set large. By doing so, the second manipulated variable that gives priority to the control accuracy of the end portion of the rolled material 2 may be calculated.

(Tension shape determination technology)
FIG. 2 is a graph for explaining a technique for determining whether or not there is a stretched shape in the rolled shape control device 5 according to the embodiment. FIG. 2 is a schematic diagram showing a shape defect in which the shape of the end portion of the rolled material is locally stretched. The plus side of the vertical axis in FIG. 2 indicates the extension, and the minus side indicates the tension shape. Hereinafter, a shape defect in which the shape of the end portion of the rolled material 2 is locally stretched is also referred to as a "specific type of shape defect".

Based on the actual shape received from the shape meter 4, the plate edge shape monitoring means 13 calculates the flatness difference at the edge of each of the work side (WS) and the drive side (DS). The work side (WS) and the drive side (DS) mean both ends of the rolled material 2 in the strip width direction, and the drive side (DS) is the side on which an electric motor (not shown) for driving the rolls is arranged. and workside (WS) means the opposite side. The flatness difference at the edge is the flatness difference between the measurement zone at the edge of the rolled material 2 and the measurement zone one inside from the measurement zone at the edge.

The plate edge shape monitoring means 13 determines whether both the WS flatness difference and the DS flatness difference simultaneously (that is, in the same control step) exceed preset threshold values. This determination is made based on the following equations (6) and (7).
β _nS+1 −β _nS ≧β ^TH (6)
β _nE−1 −β _nE ≧β ^TH (7)

Here, the symbols in formulas (6) and (7) have the following meanings. β _nS is the actual shape [I-unit] of the first measurement zone covered by the plate of the shape meter 4; β _nS+1 is the actual shape [I-unit] of the zone one inside the first measurement zone covered by the plate of the shape meter 4 . β _nE is the actual shape [I-unit] of the last measurement zone covered by the plate of the shape meter 4; β _nE−1 is the actual shape [I-unit] of the zone one inside the last measurement zone covered by the plate of the shape meter 4 . β _TH is the flatness difference threshold [I-unit]. β _TH is a predetermined threshold.

As shown in FIG. 2, a particular type of shape defect is where the measurement zone at the end of the strip varies in the tension direction from the inner zone. Therefore, based on equations (6) and (7), a specific type of shape defect occurs when the difference in flatness between the measurement zone at the end of the rolled material and the measurement zone one inside exceeds a threshold value. It is determined that It is determined that a specific type of shape defect has occurred when equations (6) and (7) are satisfied at the same time. If at least one of the formulas (6) and (7) is not satisfied, it is determined that the specific type of shape defect has not occurred.

If the equations (6) and (7) are not satisfied at the same time, the plate edge shape monitoring means 13 sets the first manipulated variable calculated by the first coolant manipulated variable calculating means 9 to the spot coolant flow rate controller 14. transmit to

When it is determined that the equations (6) and (7) are satisfied at the same time, the plate edge shape monitoring means 13 sets the second manipulated variable calculated by the second coolant manipulated variable calculating means 10 to the spot coolant flow rate control. Transmit to device 14 . This is to improve the shape defect in which the end shape of the rolled material 2 is locally stretched.

The spot coolant flow rate control device 14 controls the spot coolant spray 15 a based on the first manipulated variable or the second manipulated variable received from the plate edge shape monitoring means 13 .

According to the embodiment described above, it is possible to switch the calculation contents of the spot coolant manipulated variable depending on whether or not the end shape of the rolled material 2 has become a taut shape. When a tense shape occurs, a second manipulated variable for obtaining a high-order shape deviation improvement effect calculated by the evaluation function is used. Otherwise, the first manipulated variable corresponding to the shape deviation is used. Since the second manipulated variable calculated by the evaluation function is automatically used as necessary, the shape of the end portion of the rolled material 2 is locally stretched without depending on the skill level of the operator. Shape defects can be suppressed.

By the way, by minimizing the evaluation function J of the formula (1), the second operation amount of the spot coolant equipment 15 and the operation amount of the work roll bender and leveling in the roll actuator 12 can be obtained.

However, the work roll bender and leveling manipulated variables obtained from the evaluation function J are not used for actual control. The reason is as follows. Since the time constant of the roll actuator 12 is shorter than that of the spot coolant equipment 15, if the operation amount of the work roll bender and leveling obtained by minimizing the equation (1) is used for control, the spot coolant equipment 15 should be changed. There is a problem that the change in shape that should be done cannot catch up, and it appears as a shape deviation.

In order to avoid this problem, in the embodiment, the calculation result (actuator operation amount) by the actuator operation amount calculation means 8, which does not consider the effect of the spot coolant equipment 15, is always used as the operation amount of the roll actuator 12. be. With this function, even if a shape defect occurs in which the ends of the rolled material are stretched, it can be improved by combining the spot coolant equipment 15 and the roll actuator 12 . Furthermore, the realizable operating amount of the spot coolant equipment 15 can be easily and automatically calculated without depending on the skill level of the adjuster.

As described above, the actuator control device 11 according to the embodiment has the shape The value of the operation amount of the roll actuator 12 determined as the solution of the evaluation function when the second operation amount is calculated so that the deviation is equal to or less than the predetermined deviation is not used. Instead, the actuator control device 11 controls the roll actuator 12 based on the actuator operation amount calculated by the actuator operation amount calculation means 8 .

Thereby, in the embodiment, it is possible to appropriately divide roles between the roll actuator 12 and the spot coolant facility 15 . That is, the roll actuator 12 can only control low-order shape deviations. Since the shape defect at the end of the rolled material 2 is a high-order shape deviation, it is not detected as a control target on the roll actuator 12 side. If the spot coolant operation amount is not adjusted based on the evaluation function, the roll actuator 12 may continue to maintain the current status erroneously.

In this regard, in the embodiment, the spot coolant facility 15 can add a variable factor to the actual shape so that the roll actuator 12 side does not continue to maintain the wrong status quo. By summing the shape deviation created by the shape control of the spot coolant equipment 15 and the result of the shape control of the roll actuator 12, it is possible to obtain a preferable shape close to the target shape as a whole. As described above, the configuration according to the embodiment is not a mere addition or combination of constituent elements, but realizes high-dimensional division of roles between the roll actuator 12 and the spot coolant facility 15 .

FIG. 3 is a diagram showing the configuration of a rolling shape control device 5 according to a modification of the embodiment. A four-high cold rolling mill system 101 according to the modification of FIG. 3 has a hot coolant facility 18 in addition to the roll actuator 12 and the spot coolant facility 15 as shape control actuators. In the modification of FIG. 3, a hot coolant flow controller 17 for controlling the hot coolant equipment 18 is also added.

In the modified example of FIG. 3 , the second coolant manipulated variable calculating means 10 is replaced with a second coolant manipulated variable calculating means 16 . The following description will focus on the operations that differ from the configuration of FIG. 1, and the description of the points that are the same as those of the configuration of FIG. 1 will be omitted or simplified.

A plurality of hot coolant facilities 18 are installed in the plate width direction in the same manner as the spot coolant facilities 15 . The hot coolant facility 18 has a coolant setting temperature higher than that of the spot coolant facility 15 . Hot coolant equipment 18 and spot coolant equipment 15 have opposite effects on the plate flatness. That is, when the hot coolant equipment 18 is turned on, the work roll is locally warmed and the shape of the corresponding shape measurement zone is elongated.

In the second coolant manipulated variable calculation means 16 according to the modification, the evaluation function J further includes a term corresponding to the manipulated variable of the hot coolant equipment 18 . The second coolant operation amount calculation means 16 calculates the second operation amount for operating the spot coolant equipment 15 and the hot water so that the shape deviation in the evaluation function J after deformation is equal to or less than a predetermined deviation (preferably the minimum value). A third manipulated variable for operating the coolant installation 18 is calculated.

More specifically, the second coolant manipulated variable calculation means 16 according to the modification uses the shape deviation of each shape measurement zone received from the shape deviation calculation means 6 to determine the evaluation function J represented by Equation (8) as Calculate to minimize. As a result of this calculation, the second manipulated variable of the spot coolant equipment 15 and the third manipulated variable of the hot coolant equipment 18 are obtained for each control cycle. These calculated manipulated variables are transmitted to the strip end shape monitoring means 13 .

The shape influence factor of the above formula (9) is calculated by the following formula (10).

Here, each symbol in the above formula has the following meaning. k is the identification number [-] of the hot coolant spray 18a. M is the number [-] of hot coolant sprays 18a. ∂β _i /∂L _k ^HC is the hot coolant shape influence coefficient [I-unit/%].

ΔL _k ^HC is the manipulated variable [%] of the hot coolant equipment 18 and corresponds to the "third manipulated variable" described above. The operation amount of the hot coolant equipment 18 is also the same as that of the spot coolant equipment 15 . That is, ΔL _k ^HC represents at least one of the spray flow rate of the hot coolant spray 18a, the on/off state of the hot coolant spray 18a, and the coolant flow rate (on time ratio) of the hot coolant spray 18a.

l _k ^HC is the position [mm] of the hot coolant spray 18a of the hot coolant equipment 18 from the center of the mill. L _k ^HC_ACT is the actual flow rate [%] of the hot coolant spray 18 a of the hot coolant equipment 18 .

The evaluation function J of formula (8) according to the modification of the embodiment includes the term ε _Ci ^HC based on formula (9) in the evaluation function J of formula (1) of the first embodiment. Equation (9) calculates the shape correction amount when the hot coolant equipment 18 is operated.

When the equations (6) and (7) are satisfied at the same time, the plate end shape monitoring means 13 calculates the second manipulated variable and the third manipulated variable calculated by the second coolant manipulated variable calculating means 16 as spot coolant It is transmitted to the flow controller 14 and the hot coolant flow controller 17 .

The spot coolant flow control device 14 controls the spot coolant spray 15a according to the transmitted second manipulated variable. The hot coolant flow control device 17 controls the hot coolant spray 18a based on the transmitted third manipulated variable.

As a result, even if a shape defect occurs in which the ends of the rolled material are stretched, the operation amount can be calculated by further combining the hot coolant equipment 18, which is highly effective in improving the stretched shape of the ends of the rolled material. As a result, it is possible to easily obtain the operation amount of each of the spot coolant equipment 15 and the hot coolant equipment 18 that can improve a specific type of shape defect.

As described above, according to the modification of the embodiment, the operation amount of the hot coolant equipment 18, which is highly effective in improving the tension shape of the end portion of the rolled material 2, is combined with the roll actuator 12 and the spot coolant equipment 15. can be calculated. As a result, it is possible to more effectively suppress shape defects caused by local tension in the shape of the ends of the rolled material 2 . As a result, the effect of reducing plate breakage is further enhanced, and stable rolling can be performed.

Although the four-high cold rolling mill is illustrated in the embodiment, the rolling shape control device 5 according to the embodiment may be applied to other rolling mills regardless of the number of stages. Regardless of the type of rolling mill, a shape meter, a low-order shape control actuator for correcting low-order shape defects such as roll benders and leveling, and spot coolant equipment 15 and hot coolant equipment 18 as shape control actuators. The rolling shape control device 5 according to the embodiment can be applied to any rolling mill having a high-order shape control actuator for correcting a high-order shape defect.

4 and 5 are diagrams showing configurations of four-high cold rolling mill systems 100 and 101 according to reference examples of the embodiment. As shown in FIGS. 4 and 5, as a reference example of the embodiment, the first coolant operation amount calculation means 9 and the plate end shape monitoring means 13 are omitted, and the second coolant operation amount calculation means 10 is always used. A coolant manipulated variable calculation may be performed. In such a modified example as well, the above-described evaluation function can be used to calculate the spot coolant manipulated variable and the hot coolant manipulated variable for obtaining a high-order shape deviation improvement effect. By using the spot coolant manipulated variable and the hot coolant manipulated variable calculated by the evaluation function described above, it is possible to effectively eliminate shape defects even when the end shape of the rolled material becomes a stretched shape. As a result, it is possible to suppress shape defects caused by local tension in the shape of the ends of the rolled material, without depending on the skill level of the operator.

1 Rolling Mill 2 Rolled Material 3 Rolling Direction 4 Shape Meter 5 Rolling Shape Control Device 6 Shape Deviation Calculation Means 7 Setting Device 8 Actuator Operation Amount Calculation Means 9 First Coolant Operation Amount Calculation Means 10 Second 2 Coolant manipulated variable calculation means 11 Actuator control device 12 Roll actuator (work roll bender, leveling) 13 Plate end shape monitoring means 14 Spot coolant flow control device 15 Spot coolant equipment 15a Spot coolant spray 16 Second 2 coolant operation amount calculation means, 17 hot coolant flow control device, 18 hot coolant equipment, 18a hot coolant spray, 100, 101 four-high cold rolling mill system

Claims (4)

shape deviation calculation means for calculating a shape deviation between the actual shape and the target shape of the rolled material along the strip width direction;
actuator operation amount calculation means for calculating an actuator operation amount for operating a roll actuator that changes at least one of a roll position and a roll shape;
a first coolant manipulated variable calculation means for calculating a first manipulated variable for manipulating the spray injection of the spot coolant equipment according to the magnitude of the shape deviation;
Based on an evaluation function that predetermines the relationship between the shape deviation and the amount of operation of each of the roll actuator and the spot coolant equipment, the spot coolant is adjusted so that the shape deviation is equal to or less than a predetermined deviation in the evaluation function. a second coolant manipulated variable calculation means for calculating a second manipulated variable for manipulating the spray injection of the equipment;
A shape difference, which is a difference between a first actual shape of an end portion of the rolled material along the width direction of the strip and a second actual shape of a portion of the rolled material inside the end portion, is calculated, and the shape difference is calculated. and a predetermined threshold value to determine whether or not the end of the rolled material has a predetermined stretched shape, and if the end of the rolled material does not have the stretched shape selects the first manipulated variable and selects the second manipulated variable when the end of the rolled material is in the stretched shape;
a coolant flow rate control device that controls the spot coolant facility based on the manipulated variable selected by the plate end shape monitoring means from the first manipulated variable or the second manipulated variable;
A rolling shape control device comprising: The evaluation function further includes a term corresponding to a third manipulated variable for manipulating the spray injection of the hot coolant equipment,
The second coolant manipulated variable calculation means is configured to operate the spot coolant facility and the hot coolant facility such that the shape deviation is equal to or less than the predetermined deviation in the evaluation function. calculate the amount of
2. The rolling shape control device according to claim 1, further comprising a hot coolant flow control device for controlling said hot coolant equipment based on said third manipulated variable. 3. The rolling shape control apparatus according to claim 1, wherein said second coolant manipulated variable calculating means calculates said second manipulated variable such that said shape deviation becomes a minimum value in said evaluation function. An actuator control device that controls the roll actuator,
In the actuator control device, the shape deviation in the evaluation function is equal to or less than the predetermined deviation even when the strip end shape monitoring means determines that the end portion of the rolled material has the stretched shape. The actuator operation amount calculated by the actuator operation amount calculation means without using the value of the operation amount of the roll actuator determined as the solution of the evaluation function when the second operation amount is calculated so that The rolling shape control apparatus according to any one of claims 1 to 3, wherein the roll actuator is controlled based on.

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