JP6962860B2 - Rolling machine plate thickness control device and its method and rolling system - Google Patents

Description

The present invention relates to a plate thickness control device and a plate thickness control method for a rolling mill that automatically controls the thickness of a rolled material rolled by the rolling mill. The present invention relates to a rolling system including such a plate thickness control device.

Conventionally, when rolling a rolled material such as a film or a steel plate by using a rolling mill, the length of a gap (roll gap length) between a pair of work rolls provided in the rolling mill is adjusted. The plate thickness control device is used to control the thickness (plate thickness) of the rolled material on the output side of the pair of work rolls so as to match a desired target value (set value). Various methods such as a feedforward plate thickness control method, a mass flow plate thickness control method, and a monitor plate thickness control method are known for this plate thickness control.

For example, the automatic sheet thickness control method for a rolling mill disclosed in Patent Document 1 is a method for automatically controlling a sheet thickness using a mill constant obtained by a mill constant formula created by a method for creating a mill constant formula for a rolling mill. The method for creating the mill constant formula of the rolling mill is an operation of measuring the rolling force at a plurality of roll openings while narrowing the roll opening and an operation of measuring the rolling force at a plurality of roll openings while increasing the roll opening. By continuously repeating the above, data showing the relationship between the roll opening and the rolling force is obtained, and using these data, the roll opening is given to the rolling force by an nth-order equation (n is a natural number of 3 or more). An approximate relational expression is obtained, and the relational expression is differentiated with respect to the roll opening to create a mill constant equation that gives a mill constant to the rolling force.

Japanese Unexamined Patent Publication No. 07-178426

The output side plate thickness in the rolled material rolled by the rolling mill cannot be realized only by matching the roll gap length of the pair of work rolls with the target value of the output side plate thickness, and the plastic constant of the rolled material and the said It depends on the mill constant of the work roll. Therefore, it is necessary to control the roll gap length in consideration of the deformation of the work roll (mill constant) according to the plastic constant of the rolled material. Therefore, conventionally, as in Patent Document 1, for example, the mill constant is obtained more accurately, and the roll gap command value is obtained using the obtained mill constant to control the roll gap length, thereby achieving plate thickness accuracy. Improvements were being made.

However, if the roll gap command value is set to an inappropriate value, the roll gap command value may include a large error, or control may take a long time.

The present invention has been made in view of the above circumstances, and an object of the present invention is a plate thickness control device and a plate thickness control method for a rolling mill capable of setting a roll gap command value to a more appropriate value, and the plate thickness control. It is to provide a rolling system equipped with an apparatus.

As a result of various studies, the present inventor has found that the above object can be achieved by the following invention. That is, the plate thickness control device of the rolling mill according to one aspect of the present invention is a device that controls the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value, and is a device of the rolled material. A gap control unit that controls the roll gap length in a pair of work rolls for rolling the rolled material so that the thickness becomes a target value, and the gap control unit controls the roll gap command value from a predetermined reference value to a predetermined control amount. A mill constant adjusting unit for adjusting the mill constant of the work roll is provided so as to control the roll gap length by changing with. Preferably, in the plate thickness control device of the rolling mill described above, the gap control unit controls the roll gap length by a feedforward plate thickness control method. Preferably, in the plate thickness control device of the rolling mill described above, the gap control unit controls the roll gap length by a mass flow plate thickness control method.

Since the plate thickness control device of such a rolling mill can adjust the mill constant of the work roll, it is not possible to adjust the mill constant of the work roll when the roll gap command value can be set to an inappropriate value. Since an appropriate roll gap command value can be avoided, the roll gap command value can be set to a more appropriate value.

In another aspect, in the plate thickness control device of the rolling mill described above, the roll gap length measuring unit for measuring the roll gap length of the pair of work rolls and the roll gap length measured by the roll gap length measuring unit are used. The mill constant adjusting unit further includes an actual value calculation unit that obtains a subtracted value obtained by subtracting the target value as an actual roll gap command value, and the mill constant adjusting unit has the actual roll gap command value obtained by the actual value calculation unit. When the upper limit value in the predetermined reference range including the predetermined reference value is exceeded, the mill constant of the work roll is adjusted so that the mill constant of the work roll becomes large, and the actual result obtained by the actual value calculation unit. When the roll gap command value of is less than the lower limit value in the predetermined reference range including the predetermined reference value, the mill constant of the work roll is adjusted so that the mill constant of the work roll becomes smaller.

Such a rolling mill plate thickness control device is appropriate because it adjusts the mill constant of the work roll according to the actual roll gap command value (measured roll gap deviation value) based on the measured roll gap length. The roll gap command value can be maintained.

In another aspect, in the plate thickness control device of the rolling mill described above, at least one of the pair of work rolls is further provided with a force applying portion for applying a force toward the shaft from the outside of the work rolls, and the mill constant. The adjusting unit adjusts the magnitude of the force applied to the work roll from the outside with respect to the force applying unit in order to adjust the mill constant of the work roll.

According to this, it is possible to provide a plate thickness control device for a rolling mill that adjusts the mill constant of a work roll by applying a force from the outside of the work roll.

The method for controlling the plate thickness of the rolling mill according to another aspect of the present invention is a method of controlling the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value, and is a method of controlling the rolling mill. In the gap control step of controlling the roll gap length in a pair of work rolls for rolling the rolled material so that the thickness becomes the target value, and in the gap control step, the roll gap command value is controlled from a predetermined reference value to a predetermined control amount. It is provided with a mill constant adjusting step of adjusting the mill constant of the work roll so as to control the roll gap length by changing with. Preferably, the above-mentioned method for controlling the plate thickness of the rolling mill includes a plurality of work rolls having different mill constants in advance, and the mill constant adjusting step transfers a work roll selected from the plurality of work rolls to the rolling mill. By attaching, the mill constant of the work roll is adjusted.

Since the plate thickness control method of such a rolling mill can adjust the mill constant of the work roll, it is not possible to adjust the mill constant of the work roll when the roll gap command value can be set to an inappropriate value. Since an appropriate roll gap command value can be avoided, the roll gap command value can be set to a more appropriate value.

The rolling system according to another aspect of the present invention comprises a rolling mill and a plate thickness control device for the rolling mill that controls the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value. The plate thickness control device of the rolling mill is the plate thickness control device of any of the above-mentioned rolling mills.

According to this, it is possible to provide a rolling system including a plate thickness control device for any of the above-mentioned rolling mills. In such a rolling system, the roll gap command value can be set to a more appropriate value.

In the plate thickness control device and the plate thickness control method of the rolling mill according to the present invention, the roll gap command value can be set to a more appropriate value. Then, according to the present invention, it is possible to provide a rolling system including a plate thickness control device for such a rolling mill.

It is a figure which shows the structure of the rolling system in embodiment. It is a figure which shows the structure of the rolling mill more detailed than FIG. 1 in the rolling system. It is a figure for demonstrating the appropriateness of a roll gap command. It is a flowchart which shows the operation about the adjustment of a mill constant in the rolling system.

Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. It should be noted that the configurations with the same reference numerals in each figure indicate that they are the same configurations, and the description thereof will be omitted as appropriate. In the present specification, when they are generically referred to, they are indicated by reference numerals without subscripts, and when they refer to individual configurations, they are indicated by reference numerals with subscripts.

FIG. 1 is a diagram showing a configuration of a rolling system according to an embodiment. FIG. 2 is a diagram showing a more detailed configuration of the rolling mill than FIG. 1 in the rolling system. FIG. 3 is a diagram for explaining the appropriateness of the roll gap command. 3A, 3C and 3E show roll gap command values, and FIGS. 3B, 3D and 3F show actual roll gap command values. The horizontal axis of each figure is the elapsed time, and the vertical axis of each figure is the position of the roll gap with the target value of the roll gap length S as a reference (0).

The rolling system in the embodiment is a system for automatically rolling a rolled material to be rolled so as to have a predetermined target thickness (plate thickness), and the rolling mill and the rolled material rolled by the rolling mill. The rolling mill is provided with a plate thickness control device for controlling the rolling mill so that the thickness becomes a target value (set value). In the plate thickness control device of the rolling mill, a gap control unit that controls the roll gap length in a pair of work rolls for rolling the rolled material and the gap control unit are used so that the thickness of the rolled material becomes a target value. A mill constant adjusting unit for adjusting the mill constant of the work roll is provided so as to control the roll gap length by changing the roll gap command value from a predetermined reference value by a predetermined control amount.

More specifically, as shown in FIG. 1, such a rolling system S includes a rolling mill 1, a plate thickness control unit 2, a first speedometer 4, a first thickness meter 5, and a first. A strip-shaped rolled material WK provided with a two-speedometer 6, a second thickness meter 7, a first deflector roll 8, and a second deflector roll 9, for example, wound around the first and second reels R1 and R2. , The rolling mill 1 arranged between the first and second reels R1 and R2 rolls. The plate thickness of the rolled product produced by this rolling system S may be arbitrary, but in view of recent thinning, it is preferably in a region of, for example, several hundred microns or less or 100 μm or less.

The rolling mill 1 is an apparatus in which a rolled material WK is passed between a pair of work rolls and deformed by receiving a force from the pair of work rolls to reduce the thickness and form the target thickness. The rolling mill 1 includes a plurality of the pair of work rolls corresponding to each of the plurality of passes, and the rolled material WK is sequentially passed between each of the pair of work rolls (each pass) to obtain a thickness thereof. It may be a tandem type rolling mill that reduces the amount of rolling material to the target thickness, but in the present embodiment, the pair of work rolls is provided, and the rolled material WK is placed between the pair of work rolls in the positive direction. This is a reverse rolling mill that sequentially reduces the thickness of each pass (each pass) by passing the rolling mill one or more times in the opposite direction, and forms the rolling mill to the target thickness. That is, the pair of work rolls that perform a plurality of passes may be different or the same.

In the present embodiment, more specifically, as shown in FIGS. 1 and 2, for example, the rolling mill 1 passes the rolled material WK through the rolled material WK while applying a force between the reduction device 13 and the reduction device 13. A pair of first and second work rolls 11-1 and 11-2 for rolling and a pair of first and second backups supporting the pair of first and second work rolls 11-1 and 11-2, respectively. Rolls 12-1 and 12-2, a roll gap length measuring unit 14 for measuring the roll gap length in the pair of first and second work rolls 11-1 and 11-2 adjusted by the rolling device 13, and a roll gap length measuring unit 14. A force toward the axis is applied to at least one of the pair of first and second work rolls 11-1 and 11-2, and in the present embodiment, to the first work roll 11-1 from the outside of the first work roll 11. The upper housing HSa that houses and supports the first work roll 11-1 and the first backup roll 12-1 and the second work roll 11-2 and the second backup roll 12-2 are housed. And the supporting lower housing HSb, these pair of first and second work rolls 11-1, 11-2, pair of first and second backup rolls 12-1, 12-2, rolling gear 13, roll gap. It includes a length measuring unit 14, a force applying unit 15, an upper housing HSa, and a rolling mill housing HS accommodating the lower housing HSb. In the example shown in FIG. 1, one work roll 11 is supported by one backup roll 12, but may be supported by a plurality of backup rolls 12. That is, the rolling mill 1 may be a multi-stage rolling mill such as a vertical mill or a cluster mill.

The reduction device 13 is connected to the plate thickness control unit 2, and one of the pair of first and second work rolls 11-1 and 11-2 is close to the other according to the control of the plate thickness control unit 2. By moving or moving apart, the pair of first and second work rolls 11-1 and 11-2 adjust the length of the gap (roll gap length), and the pair of first and second work rolls 11-1 and 11-2. It is a device that presses the work rolls 11-1 and 11-2. In the present embodiment, the reduction device 13 increases the roll gap length by, for example, moving the lower housing HSb accommodating the second work roll 11-2 in contact with or away from the cylinder rod from the viewpoint of high responsiveness. It is a hydraulic reduction device to adjust. The roll gap length measuring unit 14 is connected to the plate thickness control unit 21 and outputs the measured roll gap length to the plate thickness control unit 2. In the present embodiment, the roll gap length measuring unit 14 includes, for example, a position sensor that detects the position of the cylinder rod of the reduction device 13. The position is obtained by bringing the second work roll 11-2 into contact with the first work roll 11-1 by the reduction device 13 and calibrating the sensor output of the position sensor to zero (0) when the so-called backlash is killed. The sensor output of the sensor becomes the roll gap length. For example, in the present embodiment, the force applying unit 15 is connected to the plate thickness control unit 2 and has a balance pressure adjusting cylinder that applies downward pressure to the first backup roll 12-1 according to the control of the plate thickness control unit 2. By applying a downward pressure to the first backup roll with the balance pressure adjusting cylinder, a force toward the axis is applied to the first work roll 11-1 from the outside of the first work roll 11-1. In such a force applying unit 15, when the downward pressure applied to the first backup roll 12-1 increases, the mill constant of the work roll 11 increases, while the downward pressure applied to the first backup roll 12-1 increases. As the pressure decreases, the mill constant of the work roll 11 decreases.

The first deflector roll 8 is a columnar member that can rotate around a predetermined axis and is arranged on one side of the rolling mill 1 at a position separated from the rolling mill 1 by a predetermined distance. The second deflector roll 9 is a columnar member that can rotate around a predetermined axis and is arranged on the opposite side of the rolling mill 1 at a position separated from the rolling mill 1 by a predetermined distance.

The first speedometer 4 is an apparatus for measuring the moving speed of the rolled material WK between the rolling mill 1 and the first deflector roll 8. The first speedometer 4 is connected to the plate thickness control unit 2, and outputs the measured moving speed of the rolled material WK to the plate thickness control unit 2. In the present embodiment, the first speedometer 4 is, for example, a pulse generator that measures the rotational speed of the first deflector roll 8. The second speedometer 6 is an apparatus for measuring the moving speed of the rolled material WK between the rolling mill 1 and the second deflector roll 9. The second speedometer 6 is connected to the plate thickness control unit 2, and outputs the measured moving speed of the rolled material WK to the plate thickness control unit 2. In the present embodiment, the second speedometer 6 is, for example, a pulse generator that measures the rotational speed of the second deflector roll 9.

The first thickness gauge 5 is an apparatus for measuring the thickness (plate thickness) of the rolled material WK between the rolling mill 1 and the first deflector roll 8. The first thickness gauge 5 is connected to the plate thickness control unit 2, and outputs the measured plate thickness of the rolled material WK to the plate thickness control unit 2. In the present embodiment, the first thickness gauge 5 is, for example, an X-ray transmission type thickness gauge disposed between the rolling mill 1 and the first deflector roll 8. The second thickness gauge 7 is an apparatus for measuring the thickness (plate thickness) of the rolled material WK between the rolling mill 1 and the second deflector roll 9. The second thickness gauge 7 is connected to the plate thickness control unit 2, and outputs the measured plate thickness of the rolled material WK to the plate thickness control unit 2. In the present embodiment, the second thickness gauge 7 is, for example, an X-ray transmission type thickness gauge disposed between the rolling mill 1 and the second deflector roll 9.

Here, since the sampling time interval is known in advance by measuring the speed of the rolled material WK with the first and second speed meters 4 and 6, the plate thickness control unit 2 uses the first and second thickness meters 5 The position in the longitudinal direction in the rolled material WK with respect to the thickness measured in No. 7 can be obtained, and the thickness measured in the first and second thickness gauges 5 and 7 and the position in the longitudinal direction in the rolled material WK are associated with each other. be able to. That is, the plate thickness control unit 2 can track the plate thickness of the rolled material WK in the longitudinal direction thereof.

The first and second speedometers 4 and 6 are not limited to the pulse generator, respectively, and may be other speedometers. For example, the first speedometer 4 may be a laser Doppler speedometer or the like arranged between the rolling mill 1 and the first deflector roll 8, and the second speedometer 6 may be the rolling mill 1 and the second deflector. A laser Doppler speedometer or the like arranged between the roll 9 and the like may be used. In particular, in the case of mass flow plate thickness control, the detection accuracy of the plate speed affects the plate thickness accuracy. Therefore, laser Doppler speedometers having higher detection accuracy are preferable for the first and second speedometers 4 and 6, respectively. be. The first and second thickness gauges 5 and 7 are not limited to the X-ray transmission type thickness gauges, respectively, and may be other thickness gauges. For example, the first and second thickness gauges 5 and 7 may be a laser type thickness gauge, a contact type thickness gauge, or the like, respectively.

In the case of a path in which the rolled material WK moves in the positive direction indicated by the arrow (→) in FIG. 1 (in FIG. 1, the direction from the left side to the right side of the paper surface), the first and second reels R1, R2, first and first The two speedometers 4, 6, the first and second thickness gauges 5, 7, the roll gap length measuring unit 14, and the first and second deflector rolls 8 and 9 function as follows. That is, the first reel R1 serves as an entry-side reel and supplies the wound rolled material WK to the rolling mill 1. The first deflector roll 8 changes the direction of the rolled material WK drawn from the first reel R1 to the horizontal direction. The first speedometer 4 serves as an entry-side speedometer, measures the moving speed (entry-side plate speed) of the rolled material WK on the entry side of the rolling mill 1, and outputs the measured entry-side plate speed to the plate thickness control unit 2. .. The first thickness gauge 5 serves as an entry-side thickness gauge, measures the thickness of the rolled material WK on the entry side of the rolling mill 1, and outputs the measured entry-side plate thickness to the plate thickness control unit 2. The roll gap length measuring unit 14 measures the roll gap lengths of the pair of first and second work rolls 11-1 and 11-2, and outputs the measured roll gap length to the plate thickness control unit 2. The second deflector roll 9 changes the horizontal rolled material WK sent from the rolling mill 1 in the direction of the second reel R2. The second reel R2 serves as an output reel, and winds and accommodates the rolled material WK rolled by the rolling mill 1. The second speedometer 6 serves as an output side speedometer, measures the moving speed (exit side plate speed) of the rolled material WK on the output side of the rolling mill 1, and outputs the measured output side speed to the plate thickness control unit 2. .. The second thickness gauge 7 serves as an output side thickness gauge, measures the thickness of the rolled material WK (outside plate thickness) on the output side of the rolling mill 1, and outputs the measured output side plate thickness to the plate thickness control unit 2.

On the other hand, in the case of a path in which the rolled material WK moves in the direction opposite to the forward direction indicated by the arrow (→) in FIG. 1 (the direction from the right side to the left side of the paper surface in FIG. 1), the first and second reels R1 , R2, 1st and 2nd speedometers 4 and 6, 1st and 2nd thickness gauges 5 and 7, roll gap length measuring unit 14 and 1st and 2nd deflector rolls 8 and 9 are as follows. Function. That is, the second reel R2 serves as an entry-side reel and supplies the wound rolled material WK to the rolling mill 1. The second deflector roll 9 changes the direction of the rolled material WK drawn from the second reel R2 to the horizontal direction. The second speedometer 6 serves as an entry-side speedometer, measures the entry-side plate speed of the rolled material WK on the entry side of the rolling mill 1, and outputs the measured entry-side plate speed to the plate thickness control unit 2. The second thickness gauge 7 serves as an entry-side thickness gauge, measures the entry-side plate thickness of the rolled material WK on the entry side of the rolling mill 1, and outputs the measured entry-side plate thickness to the plate thickness control unit 2. The roll gap length measuring unit 14 measures the roll gap lengths of the pair of first and second work rolls 11-1 and 11-2, and outputs the measured roll gap length to the plate thickness control unit 2. The first deflector roll 8 changes the horizontal rolled material WK sent from the rolling mill 1 in the direction of the first reel R1. The first reel R1 serves as an output reel, and winds and accommodates the rolled material WK rolled by the rolling mill 1. The first speedometer 4 serves as a discharge side speedometer, measures the discharge side plate speed of the rolled material WK on the output side of the rolling mill 1, and outputs the measured output side plate speed to the plate thickness control unit 2. The first thickness gauge 5 serves as an output side thickness gauge, measures the output side plate thickness of the rolled material WK on the output side of the rolling mill 1, and outputs the measured output side plate thickness to the plate thickness control unit 2.

The plate thickness control unit 2 is a device that controls the rolling mill 1 so that the thickness of the rolled material WK rolled by the rolling mill 1 becomes a target value (final target value) after the end of rolling, and is a device of the plate thickness control device. Corresponds to one example. In the present embodiment, the plate thickness control device 2 controls the rolling mill 1 by adjusting the roll gap length of the work roll 11 via the reduction device 13 by the feed forward plate thickness control and the mass flow plate thickness control. At this time, in the present embodiment, the plate thickness control unit 2 controls the roll gap length by changing the roll gap command value from a predetermined reference value by a predetermined control amount. Adjust the constant. The plate thickness control unit 2 includes, for example, a CPU (Central Processing Unit), a storage element (ROM (Read Only Memory), an EEPROM (Electrically Erasable Program Memory), a Memory such as a RAM (Random Memory), and a RAM (Rand) peripheral. The CPU is functionally provided with a control unit 21, a gap control unit 22, and a mill constant control unit 23 by executing a program stored in the storage element. The plate thickness control unit 21 may be configured to include a PLC (Programmable Logical Controller).

The control unit 21 controls each part 1, 2, 4 to 9 of the rolling system S according to the function of each part, and controls the entire rolling system S.

The gap control unit 22 controls the roll gap length of the work roll 11 in the rolling mill 1 by feedforward plate thickness control or mass flow plate thickness control.

The feedforward plate thickness control is a plate thickness control method in which the roll gap length is changed so that the exit side plate thickness deviation becomes zero based on the input side plate thickness. In such feedforward plate thickness control, the roll gap command value is ΔS, the input side plate thickness deviation is ΔH, the mill constant of the rolling mill 1 is M, the plastic constant of the rolled material WK is m, and the control gain is controlled. When C is, the control is generally performed by the following equation (1).
ΔS = C × (m / M) × ΔH ・ ・ ・ (1)

On the other hand, the mass flow plate thickness control is a plate thickness control method in which an estimated value of the exit side plate thickness is obtained based on the entrance side plate speed, the exit side plate speed, and the entrance side plate thickness, and the roll gap length is changed so that the exit side plate thickness deviation becomes zero. Is. This mass flow plate thickness control can be suitably used in a plate thickness in which the spread of the exit side plate width W2 with respect to the entry side plate width W1 can be ignored, that is, a plate thickness in which W1 = W2 holds. In such mass flow plate thickness control, when the inlet plate thickness is H, the outlet plate thickness is h, the outlet plate speed is V1, the outlet plate speed is V2, and the control gain is C, the following equation is generally used. It is controlled by 2).
ΔS = C × {(M + m) / M} × {H × (V1 / V2) −h} ・ ・ ・ (2)

In the mill constant control unit 23, the work roll is controlled by the force application unit so that the gap control unit 22 controls the roll gap length by changing the roll gap command value ΔS from a predetermined reference value Ref by a predetermined control amount dS. It adjusts the mill constant of 11. More specifically, the mill constant control unit 23 obtained a subtraction value obtained by subtracting the target value from the roll gap length S measured by the roll gap length measuring unit 14 as the actual roll gap command value ΔSc, and obtained this value. When the actual roll gap length command value ΔSc exceeds the upper limit value β in the predetermined reference range (range of α to β, α ≦ Ref ≦ β) including the predetermined reference value Ref, the work roll 11 The mill constant M of the work roll 11 is adjusted by adjusting the magnitude of the force applied to the work roll 11 from the outside by the force applying portion 15 so that the mill constant M becomes large, and the roll gap command of the obtained result is obtained. When the value ΔSc is less than the lower limit value α in the predetermined reference range (range of α to β) including the predetermined reference value Ref, a force is applied so that the mill constant M of the work roll 11 becomes smaller. The mill constant M of the work roll 11 is adjusted by adjusting the magnitude of the force applied to the work roll 11 from the outside by the portion 15.

The predetermined reference value Ref is a control amount (change amount) dS and a roll gap command for adjusting the roll gap command value ΔS in one plate thickness control in the plate thickness control repeatedly executed at the predetermined time interval Tc. The time until the error ε included in the value ΔS and the roll gap command value ΔS reach the predetermined reference value Ref and the like are taken into consideration, and the values are appropriately set in advance.

For example, when the control amount dS is 1 μm according to the specifications of the rolling system S such as the detection accuracy of the roll gap length (detection accuracy of the position sensor as the roll gap length measuring unit 14) (dS = 1 μm), the figure. As shown in 3C, when the predetermined reference value Ref is set to 1 μm (Ref = 1 μm), the roll gap command value ΔS is set to the predetermined reference by one plate thickness control as shown in FIG. 3D. The value reaches 1 μm. For example, when the predetermined time interval Tc is 0.001 seconds according to the specifications of the rolling system S (Tc = 0.001 seconds), the roll gap command value ΔS is 0.001 seconds (= 0.001 seconds). At × 1), the predetermined reference value of 1 μm is reached (Tref = 0.001 seconds). However, since the roll gap command value ΔS may vibrate with the control amount of 1 μm in order to converge to this reference value of 1 μm, an error ε of ± 100% (= (± 1/1) × 100) is set. It will be included (ε = 100%).

On the other hand, in order to reduce this error ε, when the predetermined reference value Ref is set to 30 μm (Ref = 30 μm) as shown in FIG. 3E, the roll gap command value ΔS is shown in FIG. 3F. Will include an error ε of ± about 3.3% (= (± 1/30) × 100) (ε = ± about 3.3%) in order to converge to this reference value of 30 μm. ε is significantly reduced as compared to the cases of FIGS. 3C and 3D. However, the roll gap command value ΔS reaches the predetermined reference value of 30 μm by controlling the plate thickness 30 times, and in the above example, the roll gap command value ΔS reaches the predetermined reference value of 30 μm. It takes 0.03 seconds (= 0.001 × 30) to reach it (Tref = 0.03 seconds).

As described above, there is a so-called trade-off relationship between the error ε included in the roll gap command value ΔS in the controlled variable dS and the time Tref until the roll gap command value ΔS reaches the predetermined reference value Ref. .. Therefore, in the present embodiment, the predetermined reference value Ref is set in advance so that the time Tref becomes the shortest within the range of the error ε allowed by the rolling system S. As in the above example, when the control amount dS is 1 μm (dS = 1 μm), the predetermined reference value Ref is appropriately set in advance to 10 μm, 12 μm, 15 μm, or the like. For example, as shown in FIG. 3A, when the predetermined reference value Ref is set to 10 μm (Ref = 10 μm), the error ε is ± 10% (= (1/10)) as shown in FIG. 3B. × 100), which is better than the case where the predetermined reference value Ref shown in FIGS. 3C and 3D is set to 1 μm, and the time terf is 0.01 seconds (= 0.001 × 10). Therefore, it is better than the case where the predetermined reference value Ref shown in FIGS. 3E and 3F is set to 30 μm. In this way, the predetermined reference value Ref is set.

From this point of view, the lower limit value α and the upper limit value β of the reference range are also set in advance, and in the above example, for example, α = 10 μm and β = 15 μm.

In the present embodiment, the mill constant control unit 23 is a performance value calculation unit that obtains a subtraction value obtained by subtracting the target value from the roll gap length measured by the roll gap length measurement unit as a performance roll gap command value. Corresponding to one example, the roll gap length measuring unit 14 functions as the actual value calculation unit, and a subtraction value obtained by subtracting the target value from the measured roll gap length is obtained as the actual roll gap command value, and this is obtained. The actual roll gap command value may be output to the plate thickness control unit 2. Further, in the present embodiment, the mill constant control unit 23 and the force application unit 15 control the roll gap length by the gap control unit changing the roll gap command value from a predetermined reference value by a predetermined control amount. As described above, it corresponds to an example of a mill constant adjusting unit for adjusting the mill constant of the work roll.

Next, the operation of this embodiment will be described. FIG. 4 is a flowchart showing an operation related to the adjustment of the mill constant in the rolling system.

In such a rolling system S, when the power is turned on, necessary initialization of each part is executed and the operation is started. Then, for example, by executing the program, the CPU of the plate thickness control unit 2 is functionally configured with the control unit 21, the gap control unit 22, and the mill constant control unit 23.

Then, in the plate thickness control of the rolled material WK, for example, when the feedforward plate thickness control is used, the gap control unit 22 repeats at a predetermined control interval (sampling interval), and the input is measured by the input side thickness meter. The roll gap command value ΔS is obtained according to the above equation 1 using the entry side plate thickness deviation ΔH based on the side plate thickness, and the obtained roll gap command value ΔS is output to the rolling mill 13. Further, for example, when mass flow plate thickness control is used, the gap control unit 22 repeats at a predetermined control interval (sampling interval), and the entry-side thickness gauge, the entry-side speedometer, the exit-side thickness gauge, and the exit-side are repeated. Using the entry-side plate thickness H, entry-side speed V1, exit-side plate thickness h, and exit-side speed V2 measured by each speedometer, the roll gap command value ΔS was obtained according to the above equation 2, and the obtained roll gap command value was obtained. ΔS is output to the reduction device 13. In this case, the mill constant M of the rolling mill 1 in the formulas 1 and 2 is the value of the mill constant of the work roll 11 adjusted by the mill constant control unit 23 via the force application unit 15 as described later. be.

During the execution of such feedforward plate thickness control and mass flow plate thickness control, the following operations related to the adjustment of the mill constant are executed by repeating at a predetermined control interval (sampling interval).

More specifically, in FIG. 4, the plate thickness control unit 2 reads the roll gap length S measured by the roll gap length measurement unit 14 by the control unit 21 from the roll gap length measurement unit 14, and the mill constant control unit 2. 23 obtains a subtraction value obtained by subtracting the target value from the roll gap length S measured by the roll gap length measuring unit 14 as an actual roll gap command value ΔSc (S11).

Next, the plate thickness control unit 2 determines whether or not the actual roll gap command value ΔSc obtained in the process S11 is within a predetermined reference range including the predetermined reference value Ref by the mill constant control unit 23. (Α ≦ ΔSc ≦ β or S12). In the above example, α = 10 μm and β = 15 μm.

As a result of the determination in the process S12, when the actual roll gap command value ΔSc is within the predetermined reference range (α ≦ ΔSc ≦ β, Yes), it is necessary to adjust the mill constant M of the work roll 11. The plate thickness control unit 2 returns the process to the process S11. On the other hand, as a result of the determination in the process S12, when the actual roll gap command value ΔSc is not within the predetermined reference range (α> ΔSc or ΔSc> β, No), the plate thickness control unit 2 , The mill constant control unit 23 determines whether or not the actual roll gap command value ΔSc obtained in the process S11 exceeds the upper limit value in the predetermined reference range (S13).

As a result of the determination in the process S13, when the actual roll gap command value ΔSc exceeds the upper limit value β (ΔSc> β, Yes), the mill constant M of the work roll 11 is increased to increase the roll gap command value. Since it is necessary to reduce ΔS, the plate thickness control unit 2 then executes the process S16 after executing the process S14. On the other hand, as a result of the determination in the process S13, when the actual roll gap command value ΔSc does not exceed the upper limit value β, that is, when the actual roll gap command value ΔSc is less than the lower limit value α (α> Δ). For Sc and No), it is necessary to reduce the mill constant M of the work roll 11 and increase the roll gap command value ΔS. Therefore, the plate thickness control unit 21 next executes the process S15 and then processes S16. To execute.

In this process S14, the mill constant control unit 23 increases the mill constant M of the work roll 11 by the preset change amount ΔM of the mill constant (M ← M + ΔM) to the force application unit 15. On the other hand, a first control signal for adjusting the magnitude of the force applied to the work roll 11 from the outside is output to the force applying unit 15 to adjust the mill constant M of the work roll 11. Upon receiving the first control signal, the force applying unit 15 applies the force to the work roll 11 from the outside with a force having a magnitude according to the first control signal. As a result, the mill constant M of the work roll 11 increases by the change amount ΔM of the mill constant, and as a result, the roll gap command value ΔSc decreases by the amount according to the change amount ΔM of the mill constant. The change amount ΔM of the mill constant is an amount for adjusting or adjusting the mill constant of the work roll 11 by one plate thickness control in the plate thickness control repeatedly executed at the predetermined time interval Tc, and is appropriately set in advance. NS.

In the process S15, the mill constant control unit 23 reduces the mill constant M of the work roll 11 by the amount of change ΔM of the mill constant (M ← M−ΔM) with respect to the force applying unit 15. A second control signal for adjusting the magnitude of the force applied to the work roll 11 from the outside is output to the force applying unit 15 to adjust the mill constant M of the work roll 11. Upon receiving the second control signal, the force applying unit 15 applies the force to the work roll 11 from the outside with a force having a magnitude according to the second control signal. As a result, the mill constant M of the work roll 11 is reduced by the change amount ΔM of the mill constant, and as a result, the roll gap command value ΔSc is increased by the amount according to the change amount ΔM of the mill constant.

In the process S16, the plate thickness control unit 2 determines whether or not the plate thickness control is continued by the control unit 21. As a result of this determination, for example, when the plate thickness control such as acceptance of the operation stop instruction is not continued, the plate thickness control unit 2 ends this process, and on the other hand, as a result of the determination, the plate thickness control is continued. In that case, the plate thickness control unit 2 returns the process to the process S11.

In this way, the mill constant M of the work roll 11 is adjusted, and the roll gap length is controlled by changing the roll gap command value ΔS from the predetermined reference value Ref with a predetermined control amount dS. In one example, in feedforward plate thickness control, when the output side plate thickness deviation Δh is 5 μm, the mill constant M of the work roll 11 is 200 ton / mm, and the plastic constant m of the rolled material WK is 200 ton / mm. The roll gap command value ΔS is 10 μm (= ((200 + 200) / 200) × 5), which is appropriate. As a result of performing a plurality of passes, when the output side plate thickness deviation Δh becomes 1 μm, the mill constant M of the work roll 11 remains 200 ton / mm, and the plastic constant m of the rolled material WK becomes 1000 ton / mm. The roll gap command value ΔS is 6 μm (= ((200 + 1000) / 200) × 1), which is not appropriate. Therefore, when the mill constant M of the work roll 11 is adjusted to 111.1 ton / mm by the above operation, it becomes about 10 μm (= ((111.1 + 1000) /111.1) × 1), which is appropriate.

As described above, the plate thickness control unit 2 as an example of the plate thickness control device in the present embodiment and the plate thickness control method mounted on the plate thickness control unit 2 can adjust the mill constant M of the work roll 11, and thus the roll gap command. When the value ΔS can be set to an inappropriate value, the improper roll gap command value ΔS can be avoided by adjusting the mill constant M of the work roll, so that the roll gap command value ΔS is more appropriate. Can be set to any value.

Since the plate thickness control device and the plate thickness control method adjust the mill constant M of the work roll 11 according to the actual roll gap command value ΔSc, an appropriate roll gap command value ΔS can be maintained.

According to the present embodiment, it is possible to provide the plate thickness control device 2 of the rolling mill 1 that adjusts the mill constant M of the work roll 11 by applying a force from the outside of the work roll 11.

Then, according to this embodiment, a rolling system S provided with such a plate thickness control device and a plate thickness control method is provided. Since this rolling system S includes the plate thickness control device and the plate thickness control method, the roll gap command value ΔS can be set to a more appropriate value.

In the above-described embodiment, the mill constant M of the work roll 11 is adjusted by applying a force from the outside of the work roll 11 by the force applying portion 15, but a plurality of work rolls 11 having different mill constants M are used. By attaching the work roll 11 selected in advance from the plurality of work rolls 11 to the rolling mill 1 according to the type of the rolled material WK, the path (the rolled material WK becomes hard when the paths are overlapped), and the like. The mill constant M of the work roll 11 may be adjusted.

In order to express the present invention, the present invention has been appropriately and sufficiently described through the embodiments with reference to the drawings above, but those skilled in the art can easily change and / or improve the above embodiments. It should be recognized that it can be done. Therefore, unless the modified or improved form implemented by a person skilled in the art is at a level that deviates from the scope of rights of the claims stated in the claims, the modified form or the improved form is the scope of rights of the claims. It is interpreted as being comprehensively included in.

S Rolling system 1 Rolling machine 2 Plate thickness control unit 4 1st speedometer 5 1st thickness meter 6 2nd speedometer 7 2nd thickness meter 11 (11-1, 11-2) Work roll 12 (12-1, 12) -2) Backup roll 13 Rolling device 14 Roll gap length measuring unit 15 Force application unit 21 Control unit 22 Gap control unit 23 Mill constant control unit

Claims (5)

A plate thickness control device for a rolling mill that controls the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value.
A gap control unit that controls the roll gap length in a pair of work rolls for rolling the rolled material so that the thickness of the rolled material becomes a target value.
The gap control unit includes a mill constant adjusting unit that adjusts the mill constant of the work roll so that the roll gap length is controlled by changing the roll gap command value from a predetermined reference value by a predetermined control amount. ,
Plate thickness control device for rolling mills. A roll gap length measuring unit for measuring the roll gap length of the pair of work rolls, and a roll gap length measuring unit.
Further provided with an actual value calculation unit that obtains a subtracted value obtained by subtracting the target value from the roll gap length measured by the roll gap length measuring unit as an actual roll gap command value.
When the actual roll gap command value obtained by the actual value calculation unit exceeds the upper limit value in the predetermined reference range including the predetermined reference value, the mill constant adjusting unit determines the mill constant of the work roll. When the actual roll gap command value obtained by the actual value calculation unit is less than the lower limit value in the predetermined reference range including the predetermined reference value by adjusting the mill constant of the work roll so as to be large. , Adjust the mill constant of the work roll so that the mill constant of the work roll becomes small.
The plate thickness control device for a rolling mill according to claim 1. At least one of the pair of work rolls is further provided with a force applying portion that applies a force toward the axis from the outside of the work roll.
The mill constant adjusting unit adjusts the magnitude of the force applied to the work roll from the outside with respect to the force applying unit in order to adjust the mill constant of the work roll.
The plate thickness control device for a rolling mill according to claim 1 or 2. It is a plate thickness control method of a rolling mill that controls the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value.
A gap control step of controlling the roll gap length in a pair of work rolls for rolling the rolled material so that the thickness of the rolled material becomes a target value, and
The gap control step includes a mill constant adjusting step of adjusting the mill constant of the work roll so as to control the roll gap length by changing the roll gap command value from a predetermined reference value by a predetermined control amount. ,
How to control the plate thickness of a rolling mill. A rolling system including a rolling mill and a plate thickness control device for the rolling mill that controls the rolling mill so that the thickness of the rolled material rolled by the rolling mill becomes a target value.
The plate thickness control device for the rolling mill is the plate thickness control device for the rolling mill according to any one of claims 1 to 3.
Rolling system.

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