JP6797696B2 - Rolling machine plate thickness control device and its method and rolling mill - Google Patents

Description

The present invention relates to a technique for feedback-controlling the plate thickness of a rolled material (thickness of a rolled material) in the longitudinal direction of the rolled material when the rolled material is rolled by a rolling mill.

A rolling machine is generally a machine provided with a pair of work rolls having a roll gap, and when the rolled material passes through the roll gap, the rolled material is pressed by the pair of work rolls to be thinly rolled.

When the rolling mill rolls the rolled material, the plate thickness of the rolled material is controlled to be a target value in the longitudinal direction of the rolled material. As such control, monitor plate thickness control, mass flow plate thickness control, feedforward plate thickness control, and the like are known. Of these, the monitor plate thickness control measures the plate thickness of the rolled material that has passed through the roll gap at a measurement position downstream of the roll gap position, and feedback that adjusts the size of the roll gap based on this measured value. It is control.

As the monitor plate thickness control, for example, in Patent Document 1, the output side plate thickness deviation of the rolled material is detected on the output side of the rolling mill, and the detected output side plate thickness deviation value is used as an input signal to control the controller based on a predetermined control operation. In the automatic plate thickness control method in which the output calculated in 1 is input to the rolling mill reduction control device to adjust the roll gap of the rolling mill, the output side plate thickness deviation value is compared with the output value of the controller. Discloses an automatic plate thickness control method for a rolling mill, which comprises reducing the control gain of the controller when both cycles are synchronous.

Japanese Unexamined Patent Publication No. 2000-84609

Rolled products are used in various fields. For example, rolled products mounted on electronic devices are required to be ultra-thin as the electronic devices become smaller and lighter. In the case of an ultra-thin rolled product, since the plate thickness of the rolled product is small, the deviation of the required plate thickness is also extremely small (for example, 1 μm or less).

An object of the present invention is a plate thickness control device for a rolling mill, a method thereof, and a rolling mill capable of controlling the plate thickness of the rolled material with high accuracy when the plate thickness of the rolled material is feedback-controlled in the longitudinal direction of the rolled material. Is to provide.

The plate thickness control device for the rolling mill according to the first aspect of the present invention is a plate thickness control device for the rolling mill that rolls the rolled material at the first position, and is located at the second position downstream from the first position. When the plate thickness of the rolled material is measured, the rolling at the first position is controlled based on the deviation of the measured value, which is the measured value, so that the rolled material can be rolled in the longitudinal direction. When the plate thickness of the rolled material is measured at the first control unit that feedback-controls the plate thickness of the rolled material and the second position, the deviation of the plate thickness of the rolled material at the first position is measured. In the calculation unit that calculates the predicted value at the time of the measurement, which is the value predicted at the time point, and the deviation of the measured value and the predicted value, one is a positive value and the other is a negative value. At a certain time, the first control unit includes a second control unit that stops the feedback control.

The feedback control executed by the first control unit is the plate of the rolled material rolled at the first position at the present time when the deviation of the plate thickness (measured value) of the rolled material measured at the second position is a positive value. The thickness deviation is considered a positive value and rolling is controlled. As a result, thereafter, the deviation of the plate thickness of the rolled material rolled at the first position is converged from a positive value to zero. The feedback control executed by the first control unit is the plate of the rolled material rolled at the first position at the present time when the deviation of the plate thickness (measured value) of the rolled material measured at the second position is a negative value. The thickness deviation is considered a negative value and rolling is controlled. As a result, thereafter, the deviation of the plate thickness of the rolled material rolled at the first position is converged from a negative value to zero.

There is a second position downstream from the first position, and the first position and the second position do not match. From this, the present inventor presents the deviation of the plate thickness of the rolled material rolled at the first position at present when the deviation of the plate thickness (measured value) of the rolled material measured at the second position is a positive value. We found that is not always a positive value and can be a negative value. Further, in the present inventor, when the deviation of the plate thickness (measured value) of the rolled material measured at the second position is a negative value, the deviation of the plate thickness of the rolled material rolled at the first position is present at the present time. We have found that it is not always a negative value, but may be a positive value.

In these cases, when the first control unit executes feedback control, the deviation of the plate thickness of the rolled material does not converge to zero and becomes larger (so-called hunting occurs). Ideally, the plate thickness of the rolled material is measured at the first position, but due to the structure of the rolling mill, the plate thickness of the rolled material cannot be measured at the first position and is downstream from the first position. The measurement is performed at the second position.

Therefore, the plate thickness control device of the rolling mill according to the first aspect of the present invention stops the feedback control in those cases. The stop of the feedback control means that the feedback control is stopped when the footback control is performed at the present time, and the stop is continued when the feedback control is stopped at the present time.

Therefore, according to the plate thickness control device of the rolling mill according to the first aspect of the present invention, when the plate thickness of the rolled material is feedback-controlled in the longitudinal direction of the rolled material, the plate thickness of the rolled material is controlled with high accuracy. it can.

The first position is, for example, the position of a gap formed by a pair of work rolls provided in the rolling mill. The rolled material is rolled by being pressed by a pair of work rolls. The rolling of the rolled material is controlled by changing the size of the gap by the feedback control.

In the above configuration, the calculation unit uses the deviation of the measured value to generate the first data indicating the deviation of the plate thickness of the rolled material measured along the longitudinal direction of the rolled material. And a second generation unit that generates a second data indicating the periodic change of the deviation based on the first data, and the predicted value is calculated using the second data.

This configuration is an example of the calculation unit. For example, the second data may be data (waveform data) indicating the fundamental frequency obtained by Fourier transforming the first data, or data (waver data) indicating the median deviations constituting the first data. However, the data (waveform data) obtained by moving averaging the first data may be used.

In the above configuration, when the deviation of the measured value and the predicted value are both positive values or both are negative values, the first control unit gives the feedback. When the control is performed, the first control unit continues the feedback control, and when the first control unit stops the feedback control, the first control unit restarts the feedback control.

Hunting does not occur when both the measured deviation and the predicted value are positive or both are negative. Therefore, the second control unit causes the first control unit to continue the feedback control when the first control unit is performing feedback control, and when the first control unit stops the feedback control, the first control unit To resume feedback control.

The method for controlling the plate thickness of the rolling mill according to the second aspect of the present invention is the method for controlling the plate thickness of the rolling mill for rolling the rolled material at the first position, at the second position located downstream from the first position. When the plate thickness of the rolled material is measured, the rolling at the first position is controlled based on the deviation of the measured value, which is the measured value, so that the rolled material can be rolled in the longitudinal direction. When the plate thickness of the rolled material is measured at the first control step of feedback-controlling the plate thickness of the rolled material and the second position, the deviation of the plate thickness of the rolled material at the first position is measured. In the calculation step of calculating the predicted value at the time of the measurement, which is the value predicted at the time point, and the deviation of the measured value and the predicted value, one is a positive value and the other is a negative value. At some point, it comprises a second control step that stops the feedback control.

The method for controlling the plate thickness of the rolling mill according to the second aspect of the present invention defines the plate thickness control device for the rolling mill according to the first aspect of the present invention from the viewpoint of the method, and relates to the first aspect of the present invention. It has the same effect as the plate thickness control device of a rolling mill.

The rolling mill according to the third aspect of the present invention is a rolling mill provided with a plate thickness control device for the rolling mill.

The rolling mill according to the third aspect of the present invention defines the plate thickness control device of the rolling mill according to the first aspect of the present invention from the viewpoint of the rolling mill, and the plate of the rolling mill according to the first aspect of the present invention. It has the same effect as the thickness control device.

According to the present invention, when the plate thickness of the rolled material is feedback-controlled in the longitudinal direction of the rolled material, the plate thickness of the rolled material can be controlled with high accuracy.

It is a block diagram which shows the structure of the rolling system in embodiment. It is a graph which shows an example of the deviation data. It is a graph which shows the waveform of the fundamental frequency obtained by Fourier transforming the deviation data. It is a flowchart explaining operation of a rolling system in an embodiment. It is explanatory drawing explaining the principle of monitor plate thickness control. It is a schematic diagram which shows the plane and the side surface of a part of a rolled material.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the configurations with the same reference numerals indicate that they are the same configuration, and the description of the configurations already described will be omitted. In the present specification, when they are collectively referred to, they are indicated by reference numerals without subscripts (for example, work roll 101), and when they refer to individual configurations, they are indicated by reference numerals with subscripts (for example, work roll 101). -1).

FIG. 5 is an explanatory diagram illustrating the principle of monitor plate thickness control. A predetermined gap is provided between the work roll 101-1 and the work roll 101-2. This gap is referred to as the roll gap RG. The rolled material WK is sent toward the roll gap RG in the direction of arrow D1 (direction from left to right when viewed from the top of FIG. 5), and is pressed by a pair of work rolls 101 as it passes through the roll gap RG. And rolled thinly. The rolled material WK that has passed through the roll gap RG is sent to the measurement position P2 (an example of the second position) downstream from the roll gap position P1 (an example of the first position). A thickness gauge 102 is arranged at the measurement position P2. The thickness gauge 102 measures the plate thickness of the rolled material WK (thickness of the rolled material WK) passing through the measurement position P2 at a predetermined time interval (for example, 1 msec interval). As a result, the plate thickness of the rolled material WK is measured along the longitudinal direction of the rolled material WK.

This measurement will be described in detail. FIG. 6 is a schematic view showing a flat surface and side surfaces of a part of the rolled material WK. The upper side of FIG. 6 shows the plane of the rolled material WK, and the lower side shows the side surface of the rolled material WK along the longitudinal direction. With reference to FIGS. 5 and 6, the rolled material WK is fed in the arrow D1 direction, and the thickness gauge 102 sequentially measures the plate thickness Th of the rolled material WK along the longitudinal direction D2 of the rolled material WK. To do. There are a number of measurement points p along the longitudinal direction D2 of the rolled material WK. The measurement point p indicates the location of the rolled material WK in which the plate thickness Th of the rolled material WK was measured by the thickness gauge 102. Since the measurement point p needs to be illustrated, the measurement point p is indicated by a black point, but such a black point does not actually exist on the rolled material WK.

With reference to FIG. 5, the monitor plate thickness control was rolled at the roll gap position P1 at the present time when the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a positive value. The deviation of the plate thickness of the rolled material WK is regarded as a positive value, and the roll gap RG is controlled to be reduced. As a result, thereafter, the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 is converged from a positive value to zero. In the monitor plate thickness control, when the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a negative value, the plate thickness of the rolled material WK rolled at the roll gap position P1 is currently controlled. The deviation is regarded as a negative value, and the roll gap RG is controlled to be increased. As a result, thereafter, the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 is converged from a negative value to zero.

The measurement position P2 is located downstream of the roll gap position P1, and the roll gap position P1 and the measurement position P2 do not match. From this, the present inventor presents a plate of the rolled material WK rolled at the roll gap position P1 at present when the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a positive value. We found that the thickness deviation is not always a positive value and may be a negative value. Further, when the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a negative value, the present inventor presents the plate thickness of the rolled material WK rolled at the roll gap position P1 at present. We found that the deviation of is not necessarily a negative value, but may be a positive value.

When the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a positive value, the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 is a negative value at present. Consider the case. In this case, if the roll gap RG is controlled to be reduced based on the fact that the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a positive value, the roll gap position P1 is subsequently controlled. The deviation of the plate thickness of the rolled material WK rolled in 1 does not converge to zero and increases in the negative direction, so that the deviation further increases (so-called hunting occurs).

When the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 is a negative value, the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 is a positive value at present. Consider the case. In this case, if the roll gap RG is controlled to be increased based on the deviation of the plate thickness (measured value) of the rolled material WK measured at the measurement position P2 being a negative value, then the roll gap position P1 The deviation of the plate thickness of the rolled material WK rolled in 1 does not converge to zero and increases in the positive direction, so that the deviation further increases (hunting occurs).

Ideally, the plate thickness of the rolled material WK is measured at the roll gap position P1, but due to the structure of the rolling mill, the plate thickness of the rolled material WK cannot be measured at the roll gap position P1 and the roll gap. The measurement is performed at the measurement position P2 downstream from the position P1.

The present inventor created an embodiment based on the above findings.

FIG. 1 is a block diagram showing a configuration of a rolling system S according to an embodiment. The rolling system S is a cold rolling system, but is not limited to this, and a hot rolling system may be used. There are tandem type and reverse type rolling mills. In the tandem type, the rolled material is rolled in order by a plurality of rolling mills arranged in the tandem. In the reverse type, the rolled material is reciprocated once or more by two reels, and the rolled material is rolled by one rolling mill. In the embodiment, the reverse type will be described as an example.

The rolling system S in the embodiment is a system that automatically rolls the rolled material WK to be rolled so as to have a predetermined target thickness (plate thickness). For example, as shown in FIG. 1, the rolling mill 1 A first length gauge 4, a first thickness gauge 5, a second length gauge 6, a second thickness gauge 7, a first deflector roll 8, and a second deflector roll 9, for example, a first reel. The strip-shaped rolled material WK wound around R1 and the second reel R2 is rolled by the rolling mill 1 disposed between the first reel R1 and the second reel R2. 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, for example, several hundred microns or less.

The rolling mill 1 includes a pair of work rolls 11, a pair of backup rolls 12, a reduction device 13, and a plate thickness control device 2.

The work roll 11-1 presses the rolled material WK from above. The work roll 11-2 presses the rolled material WK from below. A roll gap RG is formed between the work roll 11-1 and the work roll 11-2.

The backup roll 12-1 supports the work roll 11-1 in order to suppress elastic deformation and the like of the work roll 11-1. The backup roll 12-2 supports the work roll 11-2 in order to suppress elastic deformation and the like of the work roll 11-2. 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 a plate thickness control unit 21 provided in the plate thickness control device 2, and one of the pair of work rolls 11 is moved closer to the other according to the control of the plate thickness control unit 21. It is a device that reduces a pair of work rolls 11 while adjusting the size of the roll gap RG by moving them apart. In the embodiment, the reduction device 13 is, for example, a hydraulic reduction device from the viewpoint of high responsiveness.

The first deflector roll 8 is a columnar member that is arranged between the rolling mill 1 and the first reel R1 and can rotate around a predetermined axis. The second deflector roll 9 is a columnar member that is arranged between the rolling mill 1 and the second reel R2 and can rotate around a predetermined axis.

When the rolled material WK is fed in the direction of arrow D1 in FIG. 1, the first reel R1, the second reel R2, the first deflector roll 8 and the second deflector roll 9 function as follows. 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 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.

When the rolled material WK is fed in the direction opposite to the direction of arrow D1 in FIG. 1, the first reel R1, the second reel R2, the first deflector roll 8 and the second deflector roll 9 function as follows. 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 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 length measuring meter 4 measures the rotation speed of the first deflector roll 8 and measures the length of the rolled material WK wound around the first reel R1 based on the measured rotation speed. The first length measuring meter 4 includes, for example, a rotary encoder that measures the rotation speed of the first deflector roll 8 and a microcomputer that calculates the length of the rolled material WK using the measured rotation speed. The first length measuring meter 4 outputs the length information LI indicating the length of the measured rolled material WK to the deviation data generation unit 221 provided in the plate thickness control device 2, which will be described later.

The second length measuring meter 6 measures the rotation speed of the second deflector roll 9, and measures the length of the rolled material WK wound around the second reel R2 based on the measured rotation speed. The second length measuring meter 6 includes, for example, a rotary encoder that measures the rotation speed of the second deflector roll 9, and a microcomputer that calculates the length of the rolled material WK using the measured rotation speed. The second length measuring meter 6 outputs the length information LI indicating the length of the measured rolled material WK to the deviation data generation unit 221. The first length measuring meter 4 and the second length measuring meter 6 may measure the moving speed and time of the rolled material WK, and based on this, measure the length of the rolled material WK.

The first thickness gauge 5 measures the plate thickness of the rolled material WK between the rolling mill 1 and the first deflector roll 8. The first thickness gauge 5 outputs the thickness information TI indicating the measured plate thickness of the rolled material WK to the plate thickness control unit 21 and the deviation data generation unit 221. In the embodiment, the first thickness gauge 5 is, for example, an X-ray transmission type thickness gauge arranged between the rolling mill 1 and the first deflector roll 8.

The second thickness gauge 7 measures the plate thickness of the rolled material WK between the rolling mill 1 and the second deflector roll 9. The second thickness gauge 7 outputs the thickness information TI indicating the measured plate thickness of the rolled material WK to the plate thickness control unit 21 and the deviation data generation unit 221. In the 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.

The first thickness gauge 5 and the second thickness gauge 7 are not limited to the X-ray transmission type thickness gauge, respectively, and may be other thickness gauges. For example, the first thickness gauge 5 and the second thickness gauge 7 may be a laser type thickness gauge, a contact type thickness gauge, or the like, respectively.

The first length measuring meter 4 and the first thickness measuring meter 5 measure the length of the rolled material WK and measure the plate thickness of the rolled material WK, respectively, when they are located on the outlet side of the rolling mill 1. The second length measuring meter 6 and the second thickness measuring meter 7 measure the length of the rolled material WK and measure the plate thickness of the rolled material WK, respectively, when they are located on the outlet side of the rolling mill 1. In the example shown in FIG. 1, the rolled material WK is sent in the direction of arrow D1 (that is, the rolled material WK is sent from the first reel R1 to the rolling mill 1, and the rolled material WK rolled by the rolling mill 1 is the first. It is wound on a 2-reel R2). Therefore, the second length gauge 6 and the second thickness gauge 7 are located on the outlet side of the rolling mill 1. When the rolled material WK is sent in the direction opposite to the arrow D1 direction (that is, the rolled material WK is sent from the second reel R2 to the rolling mill 1, and the rolled material WK rolled by the rolling mill 1 is the first reel R1. The first length gauge 4 and the first thickness gauge 5 are located on the outlet side of the rolling mill 1.

The plate thickness control device 2 has a function of controlling the monitor plate pressure of the rolling mill 1. The plate thickness control device 2 is a microcomputer realized by hardware (CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), etc.), software, and the like. Is. The plate thickness control device 2 includes a plate thickness control unit 21, a predicted value calculation unit 22, and a stop / continuation / restart control unit 23 as functional blocks.

The plate thickness control unit 21 (an example of the first control unit) is a rolled material WK output from the first thickness gauge 5 when the first length gauge 4 and the first thickness gauge 5 are located on the outlet side of the rolling mill 1. The thickness information TI indicating the plate thickness of the rolled material WK is received, the thickness deviation Δh2 indicated by this information (that is, the deviation of the plate thickness (measured value) of the rolled material WK measured by the first thickness gauge 5) is calculated, and this deviation And the calculation formula of PID (Proportional-Integral-Differential) control are used to calculate the amount ΔS that changes the roll gap RG. As the calculation formula for PID control, a known calculation formula can be used. The plate thickness control unit 21 outputs an amount ΔS that changes the roll gap RG to the reduction device 13. The reduction device 13 adjusts the roll gap RG based on this amount. When the second length gauge 6 and the second thickness gauge 7 are located on the outlet side of the rolling mill 1, the plate thickness control unit 21 outputs the first thickness gauge 5 with respect to the thickness information TI output by the second thickness gauge 7. The same processing as in the case of the thickness information TI is performed.

As described above, when the plate thickness of the rolled material WK is measured at the measurement position P2 located downstream from the roll gap position P1, the plate thickness control unit 21 determines the deviation of the measured value, which is the measured value. Based on this, by controlling the rolling at the roll gap position P1, the plate thickness of the rolled material WK is controlled by the monitor plate thickness in the longitudinal direction of the rolled material WK.

The predicted value calculation unit 22 (an example of the calculation unit) predicts the deviation of the thickness of the rolled material WK at the roll gap position P1 when the plate thickness of the rolled material WK is measured at the measurement position P2. Calculate the value. The prediction value calculation unit 22 includes a deviation data generation unit 221 and a waveform data generation unit 222.

The deviation data generation unit 221 (an example of the first generation unit) is a rolled material WK output from the second length measuring meter 6 when the second length measuring meter 6 and the second thickness meter 7 are located on the outlet side of the rolling mill 1. The length information LI indicating the length of the rolled material and the thickness information TI indicating the plate thickness of the rolled material WK output from the second thickness meter 7 are received, and the deviation data DD (first data) is based on these information. An example) is generated. The deviation data generation unit 221 updates the deviation data DD every time the length information LI and the thickness information TI are received (in other words, every time the second thickness gauge 7 measures the plate thickness of the rolled material WK).

FIG. 2 is a graph showing an example of deviation data DD. The vertical axis of the graph shows the deviation of the plate thickness of the rolled material WK. The horizontal axis of the graph indicates the position of each part of the rolled material WK. Each point (each measurement point p shown in FIG. 6) is lined up along the longitudinal direction of the rolled material WK. The deviation data DD is data showing the deviation of the plate thickness of the rolled material WK measured along the longitudinal direction of the rolled material WK. In other words, the deviation data DD is data indicating the deviation of the thickness of each portion of the rolled material WK in the longitudinal direction of the rolled material WK.

With reference to FIG. 1, the distance between the roll gap position P1 and the measurement position P2 is, for example, 2 m. The distance between the measurement position P2 and the second deflector roll 9 is, for example, 0.5 m. At present, the second thickness of the rolled material WK being rolled at the roll gap position P1 when the length of the rolled material WK (for example, 100 m) + 2 m measured by the second length measuring meter 6 at the present time is measured. A total of 7 measures the thickness of the portion. The deviation data generation unit 221 calculates the deviation of the thickness of the portion, sets the position where the longitudinal direction of the rolled material WK is 102.5 m from the tip of the rolled material WK as the location, and the deviation of the thickness of the portion and 102.5 m And are stored in association with each other. The collection of these becomes the deviation data DD.

The waveform data generation unit 222 (an example of the second generation unit) generates second data indicating the periodic change of the deviation constituting the deviation data DD based on the deviation data DD (an example of the first data). .. For example, the waveform data generation unit 222 Fourier transforms the deviation data DD to generate the waveform data WD of the fundamental frequency (an example of the second data). The predicted value calculation unit 22 calculates the predicted value of the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 at the present time by using the waveform data WD of the fundamental frequency.

This will be described in detail. FIG. 3 is a graph showing a waveform (waveform data WD) of the fundamental frequency obtained by Fourier transforming the deviation data DD. The graph above shows the waveform of the fundamental frequency obtained by Fourier transforming the first example of the deviation data DD. The graph in the middle shows the waveform of the fundamental frequency obtained by Fourier transforming the second example of the deviation data DD. The graph below shows the waveform of the fundamental frequency obtained by Fourier transforming the third example of the deviation data DD. The vertical axis of these graphs shows the deviation of the plate thickness of the rolled material WK, and the horizontal axis shows the distance from the roll gap position P1. The position at a distance d from the roll gap position P1 is the measurement position P2.

The solid line SL-1 of the graph is the waveform (waveform data WD) of the fundamental frequency obtained by Fourier transforming the first example of the deviation data DD. The solid line SL-2 of the graph is the fundamental frequency waveform (waveform data WD) obtained by Fourier transforming the second example of the deviation data DD. The solid line SL-3 of the graph is the waveform (waveform data WD) of the fundamental frequency obtained by Fourier transforming the third example of the deviation data DD. Since the solid line SL changes periodically, the prediction value calculation unit 22 predicts the waveform from the roll gap position P1 to the measurement position P2 using the solid line SL. The dotted line DL-1 in the graph is the waveform predicted using the solid line SL-1. The dotted line DL-2 in the graph is the waveform predicted using the solid line SL-2. The dotted line DL-3 in the graph is the waveform predicted using the solid line SL-3.

Therefore, referring to FIGS. 1 and 3, when the deviation data DD is the first example, the predicted value calculation unit 22 uses the dotted line DL-1 to roll the rolled material at the roll gap position P1 at the present time. The predicted value Δh1 of the deviation of the plate thickness of WK is calculated. Let this predicted value be Δh1-1. When the deviation data DD is the second example, the predicted value calculation unit 22 calculates the predicted value Δh1 of the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 at the present time by using the dotted line DL-2. To do. Let this predicted value be Δh1-2. When the deviation data DD is the third example, the predicted value calculation unit 22 calculates the predicted value Δh1 of the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 at present by using the dotted line DL-3. To do. Let this predicted value be Δh1-3.

With reference to FIG. 1, the predicted value calculation unit 22 determines the plate thickness of the rolled material WK rolled at the roll gap position P1 at the present time each time the second thickness gauge 7 measures the plate thickness of the rolled material WK. The predicted deviation value Δh1 is calculated.

When the first length gauge 4 and the first thickness gauge 5 are located on the outlet side of the rolling mill 1, the predicted value calculation unit 22 outputs the length information LI output by the first length gauge 4 and the first thickness gauge 5. With respect to the thickness information TI, the same processing as in the case of the length information LI output by the second length gauge 6 and the thickness information TI output by the second thickness gauge 7 is performed to calculate the predicted value Δh1.

The stop / continue / restart control unit 23 has a predicted value Δh1 of the deviation of the plate thickness of the rolled material WK calculated by the predicted value calculation unit 22 and a plate thickness (measurement) of the rolled material WK calculated by the plate thickness control unit 21. When both are positive values or both are negative values with respect to the deviation Δh2 of the value), the following control is performed. When the plate thickness control unit 21 controls the monitor plate thickness, the stop / continue / restart control unit 23 causes the plate thickness control unit 21 to continue the control, and the plate thickness control unit 21 stops the monitor plate thickness control. If so, the plate thickness control unit 21 restarts the monitor plate thickness control.

The deviation Δh2 calculated by the plate thickness control unit 21 is the WK of the rolled material measured by the first thickness gauge 5 when the first length gauge 4 and the first thickness gauge 5 are located on the outlet side of the rolling mill 1. When the deviation Δh2 of the plate thickness (measured value) of the second thickness gauge 6 and the second thickness gauge 7 are located on the outlet side of the rolling mill 1, the WK plate of the rolled material measured by the second thickness gauge 7 The thickness (measured value) deviation Δh2.

The stop / continuation / restart control unit 23 (an example of the second control unit) is positive in the predicted value Δh1 of the deviation of the plate thickness of the rolled material WK and the deviation Δh2 of the plate thickness (measured value) of the rolled material WK. When the value of is negative and the other is a negative value, the following control is performed. When the plate thickness control unit 21 controls the monitor plate thickness, the stop / continuation / restart control unit 23 stops the monitor plate thickness control by the plate thickness control unit 21, and the plate thickness control unit 21 controls the monitor plate thickness. When is stopped, the plate thickness control unit 21 continues to do so. The reason why the monitor plate thickness control is stopped is that, as described above, the deviation of the plate thickness of the rolled material WK does not converge to 0, and the deviation becomes larger (hunting occurs).

With reference to FIGS. 1 and 3, for example, the predicted value Δh1-1 of the deviation of the plate thickness of the rolled material WK and the deviation Δh2-1 of the plate thickness (measured value) of the rolled material WK are both positive values. Is. When the plate thickness control unit 21 controls the monitor plate thickness, the stop / continue / restart control unit 23 causes the plate thickness control unit 21 to continue the control, and the plate thickness control unit 21 stops the monitor plate thickness control. If so, the plate thickness control unit 21 restarts the monitor plate thickness control. The predicted value Δh1-2 of the deviation of the plate thickness of the rolled material WK and the deviation Δh2-2 of the plate thickness (measured value) of the rolled material WK are both negative values. The stop / continuation / restart control unit 23 performs the same processing as in the case of both positive values.

For example, the predicted value Δh1-3 of the deviation of the plate thickness of the rolled material WK is a negative value, and the deviation Δh2-3 of the plate thickness (measured value) of the rolled material WK is a positive value. When the plate thickness control unit 21 controls the monitor plate thickness, the stop / continuation / restart control unit 23 stops the monitor plate thickness control by the plate thickness control unit 21, and the plate thickness control unit 21 controls the monitor plate thickness. When is stopped, the plate thickness control unit 21 continues to do so.

The operation of the rolling system S in the embodiment will be described by exemplifying a case where the second length measuring meter 6 and the second thickness meter 7 are on the exit side of the rolling mill 1. FIG. 4 is a flowchart illustrating the operation. With reference to FIGS. 1 and 4, the rolled material WK is supplied from the first reel R1 to the rolling mill 1, rolled by the rolling mill 1, and wound on the second reel R2.

The second thickness gauge 7 measures the plate thickness of the rolled material WK coming out of the rolling mill 1 at predetermined time intervals, and the second length measuring meter 6 measures the thickness of the rolled material WK wound on the second reel R2. The length is measured at the above time intervals (step S1). The second thickness gauge 7 outputs the thickness information TI indicating the measured plate thickness of the rolled material WK to the plate thickness control unit 21 and the deviation data generation unit 221. The second length measuring meter 6 outputs the length information LI indicating the length of the measured rolled material WK to the deviation data generation unit 221.

The plate thickness control unit 21 receives the thickness information TI output by the second thickness gauge 7, and calculates the thickness deviation Δh2 (that is, the deviation of the measured value measured by the second thickness gauge 7) indicated by the thickness information TI. (Step S2). Then, the plate thickness control unit 21 calculates the amount ΔS that changes the roll gap RG by using the deviation Δh2 and the calculation formula of the PID control (step S3).

The deviation data generation unit 221 receives the length information LI output by the second length measuring meter 6 and the thickness information TI output by the second thickness meter 7, and outputs these information and the rolled material WK so far. Deviation data DD is generated using the length information LI and the thickness information TI (step S4). The waveform data generation unit 222 generates waveform data WD using the deviation data DD (step S5).

The predicted value calculation unit 22 calculates the predicted value Δh1 of the deviation of the plate thickness of the rolled material WK rolled at the roll gap position P1 at present based on the waveform data WD (step S6).

The stop / continue / restart control unit 23 has both the predicted value Δh1 of the plate thickness deviation of the rolled material WK calculated in step S6 and the plate thickness deviation h2 of the rolled material WK calculated in step S2. It is determined whether or not the condition that is a positive value is satisfied (step S7).

When the stop / continue / restart control unit 23 determines that the above conditions are satisfied (Yes in step S7), the stop / continue / restart control unit 23 is in the case where the plate thickness control unit 21 controls the monitor plate thickness. , The plate thickness control unit 21 continues it, and when the plate thickness control unit 21 has stopped the monitor plate thickness control, the plate thickness control unit 21 restarts the monitor plate thickness control (step S8). As a result, the reduction device 13 adjusts the size of the roll gap RG by the amount ΔS that changes the roll gap RG calculated in step S3. Then, the rolling system S returns to the process of step S1.

When the stop / continue / restart control unit 23 determines that the above conditions are not satisfied (No in step S7), the predicted value Δh1 of the deviation of the thickness of the rolled material WK calculated in step S6 and the predicted value Δh1 calculated in step S2. With respect to the deviation h2 of the plate thickness of the rolled material WK, it is determined whether or not both satisfy the conditions of negative values (step S9).

When the stop / continue / restart control unit 23 determines that the above conditions are satisfied (Yes in step S9), the stop / continue / restart control unit 23 controls step S8. Then, the rolling system S returns to the process of step S1.

When the above condition is not satisfied, one of the predicted value Δh1 of the plate thickness deviation of the rolled material WK calculated in step S6 and the plate thickness deviation h2 of the rolled material WK calculated in step S2 are positive. Is the value of, and the other is a negative value. When the stop / continue / restart control unit 23 determines that the above conditions are not satisfied (No in step S9), the plate thickness control unit 21 controls the monitor plate thickness of the stop / continue / restart control unit 23. In this case, the plate thickness control unit 21 stops the monitor plate thickness control, and when the plate thickness control unit 21 stops the monitor plate thickness control, the plate thickness control unit 21 continues it (step S10). Stopping the monitor plate thickness control means that the plate thickness control unit 21 adjusts the size of the roll gap RG so that the pair of work rolls 11 do not come into contact with the rolled material WK (so as not to press the rolled material WK). Is. Therefore, the rolled material WK is supplied from the first reel R1 to the rolling mill 1 and wound on the second reel R2 even when the monitor plate thickness control is stopped.

When the first length gauge 4 and the first thickness gauge 5 are on the exit side of the rolling mill 1, the measurement position P2 becomes the position of the first thickness gauge 5, and the same processing as in steps S1 to S10 is performed.

The main effects of the embodiments will be described. In the embodiment, when one of the predicted value Δh1 and the deviation Δh2 of the measured value is a positive value and the other is a negative value (No in step S9), the monitor plate thickness control is stopped (step). S10). Therefore, according to the embodiment, when the plate thickness of the rolled material WK is controlled by the monitor plate thickness in the longitudinal direction of the rolled material WK, the plate thickness of the rolled material WK can be controlled with high accuracy.

Although the monitor plate thickness control has been described as an example of the feedback control, other feedback controls can also be applied to the embodiment.

1 Roller 4 1st length gauge 5 1st thickness gauge 6 2nd length gauge 7 2nd thickness gauge 8 1st deflector roll 9 2nd deflector roll 11-1, 11-2 Work roll 12-1, 12-2 Backup Roll DD deviation data d Distance from roll gap position LI Length information indicating the length of rolled material P1 Roll gap position P2 Measurement position p Measurement point of plate thickness of rolled material R1 1st reel R2 2nd reel RG Roll gap S Rolling system Th Plate thickness of rolled material TI Thickness information indicating the thickness of rolled material WD Waveform data WK Rolled material

Claims (5)

A plate thickness control device for a rolling mill that rolls a rolled material at the first position.
When the plate thickness of the rolled material is measured at the second position located downstream from the first position, the rolling at the first position is controlled based on the deviation of the measured value which is the measured value. By doing so, in the longitudinal direction of the rolled material, a first control unit that feedback-controls the plate thickness of the rolled material and
When the thickness of the rolled material at the second position is measured, the predicted value of the rolled material of thickness deviation at said first position at the time of a value obtained by prediction is the measurement at the time of the measurement And the calculation unit that calculates
When one of the deviation of the measured value and the predicted value is a positive value and the other is a negative value, the second control unit stops the first control unit from performing the feedback control. And, a rolling mill plate thickness control device. The calculation unit includes a first generation unit that generates first data indicating a deviation of the plate thickness of the rolled material measured along the longitudinal direction of the rolled material using the deviation of the measured value, and the first generation unit. The first aspect of claim 1, wherein the second generation unit for generating the second data indicating the periodic change of the deviation based on the one data is provided, and the predicted value is calculated using the second data. The plate thickness control device for the rolling mill described. In the second control unit, when both the deviation of the measured value and the predicted value are positive values or both are negative values, the first control unit performs the feedback control. If the feedback control is continued, the first control unit is allowed to continue the feedback control, and if the first control unit is stopped, the first control unit is allowed to restart the feedback control. The plate thickness control device for the rolling mill described in 1. This is a method for controlling the plate thickness of a rolling mill that rolls a rolled material at the first position.
When the plate thickness of the rolled material is measured at the second position located downstream from the first position, the rolling at the first position is controlled based on the deviation of the measured value which is the measured value. By doing so, in the longitudinal direction of the rolled material, the first control step of feedback-controlling the plate thickness of the rolled material and
When the thickness of the rolled material at the second position is measured, the predicted value of the rolled material of thickness deviation at said first position at the time of a value obtained by prediction is the measurement at the time of the measurement And the calculation step to calculate
The plate thickness of the rolling mill provided with a second control step for stopping the feedback control when one is a positive value and the other is a negative value in the deviation of the measured value and the predicted value. Control method. A rolling mill provided with a plate thickness control device for the rolling mill according to any one of claims 1 to 3.

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