JP5637637B2 - Plate thickness control device, plate thickness control method, plate thickness control program - Google Patents

Description

  The present invention relates to plate thickness fluctuation caused by so-called roll eccentricity, etc., which occurs in relation to the rotation position of a work roll or the like in a plate thickness control device, plate thickness control method, plate thickness control program in a metal material rolling mill. The present invention relates to a plate thickness control device, a plate thickness control method, and a plate thickness control program.

  One of quality control in thin plate rolling and thick plate rolling is plate thickness control (Automatic Gage Control: AGC) for controlling the plate thickness of the central means in the width direction of the rolled material. The thickness control method includes a monitor AGC that feeds back the measured value of the thickness gauge installed on the exit side of the rolling mill, and a gauge that uses the gauge meter thickness estimated from the rolling load and roll gap (gap between the upper and lower work rolls). There are a meter AGC (GM-AGC), a mill constant variable control (MMC) by rolling load, and the like.

  Disturbances that hinder the improvement in sheet thickness accuracy include temperature fluctuations of the rolled material in hot rolling. Disturbances common to hot and cold rolling include other controls such as tension fluctuation due to deterioration of tension control, changes in speed and roll gap due to operator intervention, roll structure and roll polishing due to poor system There is eccentricity.

  Among these, roll eccentricity is caused by the shaft moving up and down when the keyway in a backup roll having an oil bearing receives a large rolling load of several hundred tons to a few thousand tons. As a result, roll gap fluctuations occur. However, even in a roll without a key groove, a roll gap variation depending on roll rotation occurs due to, for example, asymmetry during roll polishing and uneven thermal expansion.

  In addition, even in the case of a so-called 2Hi mill composed of only two upper and lower work rolls, even in the case of a so-called 4Hi mill composed of two upper and lower work rolls and two backup rolls, two upper and lower work rolls, Even in the case of a so-called 6Hi mill composed of six intermediate rolls and two backup rolls, the following can be considered similarly. For the sake of expression, the work roll is called a work roll (sometimes abbreviated as “Work Roll: WR”), and the backup roll is called a backup roll (sometimes abbreviated as “BACK UP Roll: BUR”). I will decide.

  Disturbances that depend on roll shaft runout such as roll eccentricity cannot be detected by the roll gap detector. The apparatus for setting the roll gap is controlled by feeding back the detection value by the roll gap detector so as to be a given gap. However, since the roll axis fluctuation does not appear in the detection value, it cannot be controlled. However, disturbances that depend on roll axis runout appear in the rolling load because they change the actual roll gap. For this reason, it becomes big disturbances, such as said MMC using a rolling load, GM-AGC.

  In order to reduce disturbance due to roll shaft runout such as roll eccentricity, for example, it is provided in a rolling mill that rolls a metal material, resulting from roll eccentricity of the upper and lower work rolls and upper and lower backup rolls of the rolling stand. It is a plate thickness control device that controls fluctuations in plate thickness, which is detected by a rolling load detector that detects the kiss roll load and rolling load, and a rolling load detector at multiple rotational positions of the upper and lower work rolls and the upper and lower backup rolls. Based on the kiss roll load, the fluctuation component of the kiss roll load due to the eccentricity of the upper work roll and the upper backup roll at each rotational position, and the lower work roll and the lower backup roll at each rotational position. Kiss roll load fluctuation extracting means for separately extracting fluctuation components caused by roll eccentricity; The upper work roll and the upper backup roll at each rotational position of the rolling load detected by the rolling load detector at each rotational position based on each fluctuation component of the load at the time of kiss roll extracted separately by the load fluctuation extracting means at the time of roll Rolling load vertical fluctuation extracting means for separately extracting the fluctuation component caused by roll eccentricity and the fluctuation component caused by roll eccentricity of the lower work roll and the lower backup roll at each rotational position, and rolling load vertical An operation amount for calculating a roll gap command value corresponding to each rotational position so as to reduce the plate thickness variation of the rolled metal material based on each variation component of the rolling load extracted separately by the variation extracting means. Based on the roll gap command value calculated by the calculation means and the operation amount calculation means, the rotation corresponding to each rotational position is performed. Roll gap operating means for operating the gap, and accurately separating and separating the rolling load fluctuation caused by the rotation of the upper roll and the rolling load fluctuation caused by the rotation of the lower roll. A plate thickness control device that controls the roll gap according to each rolling load variation has been proposed (see, for example, Patent Document 1).

International Publication No. 2008/090596

  By the way, when there is a difference in diameter between the upper and lower backup rolls, a so-called beat or beat phenomenon occurs due to a difference in rotational speed between the upper and lower backup rolls, resulting in deterioration of control performance.

Here, the occurrence of beats or beats will be described. The upper and lower backup roll diameters are different, the upper backup roll rotation frequency is ω _T [rad / s] and the lower backup roll rotation frequency is ω _B [rad / s]. If there is no initial phase difference, the signal Y after superimposing the rotation of the upper and lower backup rolls is as follows.

The frequency of the sine wave (sin) is ω _T + ω _B [rad / s], and the frequency is high, that is, a short period and fine vibration appear. On the other hand, the frequency of the cosine wave (cos) is ω _T −ω _B [rad / s], and the frequency is low, that is, a long period and a large vibration appear.

FIG. 8A shows examples of waveforms of sin (w _T t) (solid line) and sin (w _B t) (dotted line). The frequencies were set to w _T = 5 rad / s and w _B = 4 rad / s. FIG. 8B shows an example of a waveform of sin (w _T t) and sin (w _B t) superimposed (solid line) and cos {(w _T −w _B ) t / 2} (dashed line). Show. The horizontal axis is time (s). It can be seen that the envelope of the superimposed waveform is represented by a long-period wave (broken line).

  However, in the sheet thickness control device described in Patent Document 1, both the so-called kiss roll load that causes the upper and lower work rolls to come into contact with each other when not rolling, and the rolling load that occurs when rolling is performed. , The roll eccentric component generated in the upper backup roll and the roll eccentric component generated in the lower backup roll were separated, so the kiss roll load was measured when not rolling. There was a problem that it was necessary and it took time and effort.

  Therefore, in the present invention, a plate thickness control device, a plate thickness control method, and a plate thickness control program capable of operating the roll gap of the rolling stand using a rolling load measured during rolling without using a kiss roll load. The purpose is to provide.

In order to achieve the above object, the first feature of the plate thickness control apparatus according to the present invention is that an upper roll set of an upper work roll and an upper backup roll , a lower roll set of a lower work roll and a lower backup roll, A sheet thickness control device for controlling a variation in sheet thickness of a rolled material produced by rolling a metal material between, a rolling load detection means for detecting a rolling load on the metal material, and the rolling load detection means The rolling load detected by the upper and lower rolling loads distributed up and down based on the ratio of the upper rolling load generated in the upper roll set and the lower rolling load generated in the lower roll set. Based on the rolling load of the upper roll set and the lower roll set distributed up and down by the distribution means and the rolling load vertical distribution means, Rolling load vertical fluctuation value extracting means for extracting the upper rolling load fluctuation value and the lower rolling load fluctuation value generated in relation to the rotational position of the upper roll set and the lower roll set, and the rolling load vertical fluctuation value extraction Based on the upper rolling load fluctuation value and the lower rolling load fluctuation value extracted by the means, an operation amount calculating means for calculating a work roll gap command value between the upper work roll and the lower work roll; A roll gap operating means for operating a work roll gap between the upper work roll and the lower work roll based on the work roll gap command value calculated by the operation amount calculating means. .

In order to achieve the above object, a second feature of the sheet thickness control apparatus according to the present invention is that the operation amount calculation means is configured to perform the rolling until the upper roll set and the lower roll set rotate for a predetermined time or more. Based on the upper rolling load fluctuation value and the lower rolling load fluctuation value extracted by the load up and down fluctuation value extraction means, the work roll gap command value between the upper work roll and the lower work roll is calculated,
When the upper roll set and the lower roll set are rotated for a predetermined time or more, the upper backup roll and the lower backup are based on an integrated value of the rolling load fluctuation value calculated by the rolling load up / down fluctuation value extracting means. identified roll eccentricity of the roll, calculating the work roll gap command value between the lower work roll and the upper work roll on the basis of the identified roll eccentricity lies in.

To achieve the above object, a third aspect of the gauge control apparatus according to the present invention, the rolling load vertical distribution means, a ratio to distribute the rolling load detected by said rolling load detecting means up and down, the Immediately after exchanging the upper backup roll and the lower backup roll , set to 0.5, after exchanging the upper backup roll and the lower backup roll, after the next rolled material, the operation amount calculating means of the current rolled material The setting is based on the deviation of the rolling load.

To achieve the above object, a fourth aspect of the gauge control apparatus according to the present invention, the rolling load vertical distribution means, a ratio to distribute the rolling load detected by said rolling load detecting means up and down, the Immediately after exchanging the upper backup roll and the lower backup roll , set to 0.5, after exchanging the upper backup roll and the lower backup roll, after the next rolled material, the operation amount calculating means of the current rolled material The amplitude of the periodic function is identified using the integrated value of the rolling load fluctuation value, and the ratio to the total value of the amplitude for the upper roll set and the amplitude for the lower roll set is set.

In order to achieve the above object, the thickness control method according to the present invention is characterized in that an upper roll set of an upper work roll and an upper backup roll , and a lower roll set of a lower work roll and a lower backup roll. A sheet thickness control method for controlling a sheet thickness variation of a rolled material produced by rolling a metal material, the step of detecting a rolling load on the metal material, and the detected rolling load being detected by the upper roll set Based on the ratio of the upper rolling load generated in the lower roll load generated in the lower roll set, the step of distributing up and down, the upper roll set distributed up and down and the Based on the rolling load of the lower roll set, upper rolling occurs in relation to the rotational position of the upper roll set and the lower roll set. A step of extracting a heavy fluctuation value and a lower rolling load fluctuation value, and between the upper work roll and the lower work roll based on the extracted upper rolling load fluctuation value and lower rolling load fluctuation value. Calculating a work roll gap command value, and operating a work roll gap between the upper work roll and the lower work roll based on the calculated work roll gap command value. Is to have.

In order to achieve the above object, the thickness control program according to the present invention is characterized in that an upper roll set of an upper work roll and an upper backup roll , and a lower roll set of a lower work roll and a lower backup roll. A plate thickness control program for causing a computer to control a plate thickness variation of a rolled material manufactured by rolling a metal material, the step of detecting a rolling load on the metal material, detected Distributing the rolling load up and down based on the ratio of the upper rolling load generated in the upper roll set and the lower rolling load generated in the lower roll set, and distributing up and down Based on the rolling load of the upper roll set and the lower roll set, the upper roll set and the lower side Extracting the upper rolling load fluctuation value and the lower rolling load fluctuation value generated in relation to the rotational position of the roll set, based on the extracted upper rolling load fluctuation value and the lower rolling load fluctuation value, A step of calculating a work roll gap command value between the upper work roll and the lower work roll, and based on the calculated work roll gap command value, between the upper work roll and the lower work roll. And a step of manipulating the work roll gap between them.

  According to the present invention, the rolling load fluctuation component generated in relation to the roll rotation position such as roll eccentricity using the rolling load measured during rolling of the metal material without using the kiss roll load, that is, the roll A rolling load fluctuation component due to eccentricity or the like is extracted, and the roll gap of the rolling stand can be manipulated so as to reduce the rolling load fluctuation.

It is a whole lineblock diagram showing the board thickness control device concerning a 1st embodiment of the present invention. It is a figure which shows the concept of the rolling load measured in the plate | board thickness control apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the relationship between the division | segmentation of the upper-lower side backup roll with which the plate | board thickness control apparatus which concerns on the 1st Embodiment of this invention was equipped, and the upper-lower side work roll. It is a figure which shows an example of the method of extracting a rolling load fluctuation part by a mode that a rolling load changes with the change of a backup roll rotation angle, and roll eccentricity. It is a block diagram which shows in detail the structural example of the rolling load up-and-down fluctuation extraction means and the operation amount calculating means with which the plate | board thickness control apparatus which concerns on the 1st Embodiment of this invention was equipped. It is a figure for demonstrating the mode of rotation of an up-and-down side backup roll. It is explanatory drawing which shows the change of the value stored in the adder of the upper side backup roll in the plate | board thickness control apparatus which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the state of a beat.

BEST MODE FOR CARRYING OUT THE INVENTION

(First embodiment)
FIG. 1 is an overall configuration diagram showing a plate thickness control apparatus according to a first embodiment of the present invention.

  In FIG. 1, a plate thickness control apparatus according to a first embodiment of the present invention is a control apparatus including a rolling mill that rolls a rolled material 1 made of a metal material, and includes a housing 2, an upper work roll 3a, and a lower work roll 3a. The work roll constituted by the side work roll 3b, the backup roll 4 constituted by the upper backup roll 4a and the lower backup roll 4b, the rolling means 5 for applying the rolling load to the rolled material 1, and the rolling load are detected. Rolling load detection means 6, a roll rotation number detector 7 for detecting the rotation number of the roll, a roll reference position detector 8 for detecting a predetermined reference position every time the backup rolls 4a and 4b make one rotation, and a work roll A roll gap detector 9 that detects a gap between 3a and 3b, that is, a roll gap, is provided. Here, while the upper work roll 3a and the upper backup roll 4a constitute the upper roll set of the present invention, the lower work roll 3b and the lower backup roll 4b constitute the lower roll set of the present invention.

  Further, as shown in FIG. 1, the sheet thickness control apparatus according to the first embodiment of the present invention includes a rolling load vertical distribution means 10, a rolling load vertical fluctuation extraction means 11, an operation amount calculation means 12, Roll gap operating means 13.

  The rolling load up-and-down distribution means 10 uses the upper work roll 3a and the upper backup, which are upper roll sets, to detect the rolling load detected by the rolling load detection means 6 at a plurality of rotational positions of the work rolls 3a and 3b and the backup rolls 4a and 4b. Based on the ratio between the upper rolling load generated in the roll 4a and the lower rolling load generated in the lower work roll 3b and the lower backup roll 4b as the lower roll set, the upper and lower rolling loads are distributed vertically.

  The rolling load up / down variation extracting means 11 relates to the rotational positions of the upper roll set and the lower roll set based on the rolling load of the upper roll set and the lower roll set distributed up and down by the rolling load up / down distribution means 10. Thus, the upper rolling load fluctuation value and the lower rolling load fluctuation value generated are extracted.

  The operation amount calculation means 12 is based on the fluctuation components above and below the rolling load separately extracted by the rolling load vertical fluctuation extraction means 11 so as to reduce the plate thickness fluctuation of the rolled material 1 being rolled. A roll gap command value corresponding to each rotational position is calculated.

  The roll gap operating means 13 is for operating the roll gap corresponding to each rotational position based on the roll gap command value calculated by the operation amount calculating means 12. Further, the roll gap operation means 13 uses, for example, a value obtained by adding the roll gap correction amount calculated by the operation amount calculation means 12 to the roll gap amount obtained by MMC or GM-AGC as a set value of the roll gap. , Controlling the reduction means 5.

  In the following description, as an example, a case of a 4Hi mill constituted by four upper and lower work rolls 3a and 3b and two upper and lower backup rolls 4a and 4b will be described. However, the present invention is not limited to this. Rather, even in the case of a so-called 2Hi mill composed of only two upper and lower work rolls, even in the case of a so-called 6Hi mill composed of two upper and lower work rolls, two intermediate rolls and two backup rolls. In other cases, the same can be considered.

  The plate thickness control apparatus according to the first embodiment of the present invention is configured as described above, and the roll gap and speed are appropriately adjusted so that the rolled material 1 has a desired plate thickness on the exit side. The work rolls 3a and 3b are rolled. Here, the work rolls 3a and 3b are supported by the upper backup roll 4a from above and the lower work rolls 3a and 3b are supported from below by the lower backup roll 4b. It is configured so that there is less deflection. Further, the backup rolls 4 a and 4 b are rotatably supported with respect to the rolling mill housing 2 and have a structure that can sufficiently withstand a rolling load applied to the rolled material 1.

  There are two types of reduction means 5, one based on electric motor control (referred to as electric pressure reduction) and one based on hydraulic control (referred to as hydraulic pressure reduction), but it is easier to obtain a high-speed response with hydraulic pressure reduction. For this reason, in order to perform rolling load control corresponding to a wave component having a short period such as disturbance due to roll eccentricity, generally, hydraulic pressure reduction capable of high-speed response is employed. Further, the gap between the work rolls 3 a and 3 b, that is, the roll gap is adjusted by the reduction means 5.

  The rolling load detection means 6 is, for example, a method of directly measuring a rolling load with a load cell (Load Cell) embedded between the rolling mill housing 2 and the reduction means 5 or a pressure detected by the hydraulic reduction means. The rolling load is detected by a method of calculating the rolling load.

  The roll rotation number detector 7 is provided on the work rolls 3a and 3b and the shaft (not shown) of the electric motor that drives the work rolls 3a and 3b, and detects the rotation number of the work rolls 3a and 3b. . Here, the roll rotation number detector 7 detects, for example, a pulse output unit that outputs a pulse corresponding to the rotation angle of the work rolls 3a and 3b, and a pulse output from the pulse output unit to detect the work rolls 3a and 3b. Is provided so as to be able to detect a more detailed rotation angle as well as the rotation number of the work rolls 3a and 3b. In addition, when the ratio of the diameters of the work rolls 3a and 3b and the backup rolls 4a and 4b is known, based on the rotation speed and rotation angle of the work rolls 3a and 3b detected by the roll rotation speed detector 7, The rotational speed and rotational angle of the backup rolls 4a and 4b when there is no slip between the work rolls 3a and 3b and the backup rolls 4a and 4b can be easily calculated.

  The roll reference position detector 8 detects the reference position by, for example, detecting a detection object provided on the backup rolls 4a and 4b by a sensor such as a proximity switch every time the backup rolls 4a and 4b make one rotation. To do. Further, for example, by using a pulse generator, a pulse depending on the rotation angle of the backup rolls 4a and 4b is taken out, and the reference position is detected by detecting the rotation angle of the backup rolls 4a and 4b. . Although FIG. 1 shows the case where the roll reference position detector 8 is attached only to the upper backup roll 4a, the roll reference position detector 8 is attached to the backup rolls 4a and 4b, and each of the backup rolls 4a and 4b. You may comprise so that a reference position may be detected.

  The roll gap detector 9 is provided between, for example, the backup rolls 4a and 4b and the rolling-down means 5, and detects a roll gap that is indirectly formed between the work rolls 3a and 3b.

  Next, with reference to FIG. 2 to FIG. 6, the operation of the sheet thickness control apparatus according to the first embodiment, particularly, the rolling load vertical distribution means 10, the rolling load vertical fluctuation extraction means 11, the operation amount calculation means. Each of the 12 configurations and operations will be specifically described.

  FIG. 2 is a diagram showing a concept of rolling load measured by the plate thickness control apparatus according to the first embodiment. FIG. 2 shows a rolling load 101 when roll eccentricity does not occur, and a rolling load 102 when roll eccentricity occurs, and 1 in the backup rolls 4a and 4b from time t1 to time t2. This is the amount of rotation.

  As shown in FIG. 2, the rolling load 101 is time t, that is, the rotation of the roll, due to the temperature change or the plate thickness change of the rolled material 1 even when the roll eccentricity does not occur in the backup rolls 4a and 4b. Fluctuates with.

  On the other hand, when roll eccentricity has occurred in the backup rolls 4a, 4b, etc., the rolling load 102 is obtained by superimposing the rolling load fluctuation due to other than roll eccentricity on the rolling load fluctuation component due to roll eccentricity. expressed. In addition, the specific control in the plate thickness control apparatus described below accurately separates the rolling load fluctuation due to roll eccentricity and the rolling load fluctuation due to other than roll eccentricity, and the rolling load fluctuation due to roll eccentricity is separated from the main plate. It is a basic idea to control with a thickness control device and to control rolling load fluctuations other than roll eccentricity with the MMC or GM-AGC.

  Next, based on FIG. 3, items necessary for describing each configuration and operation of the rolling load up / down fluctuation extracting means 11 and the like will be described.

  FIG. 3 is a diagram for explaining the positional relationship between the work rolls (WR) 3a and 3b and the backup rolls (BUR) 4a and 4b.

  As shown in FIG. 3, the backup rolls (BUR) 4a and 4b are provided with a position scale 14 for detecting the rotational position. Further, a reference position 4c that is preset in a part of the backup rolls (BUR) 4a and 4b and rotates in conjunction with the rotation of the backup rolls (BUR) 4a and 4b is shown.

  The position scale 14 is provided, for example, immediately outside the backup rolls (BUR) 4a and 4b so as to surround the backup rolls (BUR) 4a and 4b, and the entire circumference of the backup rolls (BUR) 4a and 4b is n. A scale is provided so as to be equally divided, that is, every predetermined angle (360 / n degrees) around the rotation axis of the backup rolls (BUR) 4a and 4b. Then, the reference position 14a (fixed reference position) of the position scale 14 is set to 0, and numbering is performed up to the (n-1) th. Note that n is set to a value of about n = 30 to 40, for example. Here, the position scale 14 is provided to explain the rolling load up / down fluctuation extracting means 11 and the like, and the scale itself may not be attached to actual equipment.

Here, θ _WT0 is the rotation angle of the work roll 3 when the reference position 4c of the backup rolls (BUR) 4a, 4b coincides with the fixed reference position 14a, and θ _WT is the backup roll (BUR) 4a, 4b is the rotation angle of the work roll 3 after rotating by _θBT . Here, θ represents an angle, the left side W of the subscript represents the work roll 3, B represents the backup roll 4, the right side T of the subscript represents the upper side, and B represents the lower side. In the following, the rotation angles of the backup rolls (BUR) 4a, 4b are the reference positions 4c of the backup rolls (BUR) 4a, 4b from the fixed reference position 14a to the backup rolls (BUR) 4a, 4b. It shall represent the angle that moves in conjunction with the rotation. For example, if the rotation angle of the backup rolls (BUR) 4a and 4b is 90 degrees, the reference position 4c of the backup rolls (BUR) 4a and 4b is changed from the fixed reference position 14a to the backup rolls (BUR) 4a and 4b. It shows that it is in a position rotated 90 degrees in the direction of rotation. Further, the state in which the rotation angle of the backup rolls (BUR) 4a, 4b is at the closest scale of the position scale 14 (for example, the jth scale of the position scale 14) is the rotation angle of the backup rolls (BUR) 4a, 4b. A description will be given assuming that the number is j.

  In addition, by embedding a sensor such as a proximity sensor and a detected object detected by the sensor in the reference position 4c and the fixed reference position 14a of the backup rolls (BUR) 4a and 4b, the sensor and the detected object are detected. The roll reference position detector 8 may be configured by a body. In this case, for example, the proximity sensor provided at the reference position 4c of the backup rolls (BUR) 4a, 4b is embedded in the reference position 14a by rotating together with the backup roll 4 and reaching the fixed reference position 14a. The detected object is detected by the proximity sensor. That is, it is recognized that the reference position 4c of the backup rolls (BUR) 4a and 4b has passed the fixed reference position 14a. The roll reference position detector 8 is not essential for the present invention.

The division positions from the fixed reference positions 0 to n-1 are set equal to the division of the rolling load recording area (P _{0 to} P _{n-1 in} FIG. 5) in FIG. The rolling load at is stored in the recording area. Generally, a value of about n = 30 to 90 is used. In order to increase n, the calculation processing capability of the controller must be high, so it is necessary to pay attention to the contradictory relationship between the fineness of control and the calculation capability.

  Hereinafter, the backup roll rotation angle represents an angle at which the backup roll reference position moves from the fixed reference position according to the rotation of the backup rolls 4a and 4b. For example, the backup roll rotation angle being 90 degrees indicates that the backup roll reference position is 90 degrees in the rotation direction of the backup rolls 4a and 4b from the fixed reference position. Further, when the backup roll rotation angle is at a position closest to the position scale (for example, the i-th position scale), it is assumed that the backup roll rotation angle number is i.

  Next, based on FIG. 4, the method to extract the fluctuation | variation component resulting from roll eccentricity of a rolling load is demonstrated.

FIG. 4 is a diagram showing a change in rolling load accompanying a change in the rotation angle of the backup roll. In FIG. 4, when the reference position 4c of the backup roll 4 is at the reference position 14a, that is, when the rotation angle number of the backup roll 4 is 0, the rolling load indicates P10, and the rotation angle number of the backup roll 4 is The rolling load changes as P ₁₁ , P ₁₂ , P ₁₃ ,. Then, when the backup roll 4 makes one rotation, the rotation angle number becomes 0 again from (n−1), and the rolling loads P ₁₀ and P ₂₀ are connected by the straight line 103 when the rolling load P ₂₀ is collected, This straight line 103 can be regarded as a rolling load excluding a rolling load fluctuation due to roll eccentricity. Therefore, the rolling load fluctuation due to roll eccentricity can be obtained from the difference between the rolling load P ₁₁ , P ₁₂ , P ₁₃ ... P ₂₀ measured at each rotation angle number and the straight line.

The actually measured value (actual value) of the rolling load P _ij includes a noise component in addition to the rolling load fluctuation due to temperature fluctuation, plate thickness fluctuation, tension fluctuation, etc., and rolling load fluctuation due to roll eccentricity. There are many cases. For this reason, the actual value of the actual rolling load P _ij is not distributed on a gentle curve as shown in FIG. 4, but the rolling load P _{i0 at the} starting point and the rolling load P at the end point to be connected to obtain the straight line. _It may be difficult to specify _{(i + 1) 0} . Therefore, assuming that the change between the rolling load P _i0 and the rolling load P _{(i + 1) 0} is not large, the measured rolling loads P _i0 , P _i1 , P _i2 , P _i3 ... P _{(i + 1) 0,} regarded as a variation component of the difference [Delta] P _ij between the n average value of rolling load _{P i0, P i1, P i2} , P i3 ... P i (n-1), due to roll eccentricity rolling force be able to. The advantage of this method is that the collection of the actual value of the rolling load can be reduced to the (n-1) th section, and it is also strong against fluctuations in the rolling load due to noise or the like. Note that it is also an effective means to reduce the noise component by filtering the actual value of the rolling load.

<Operation of plate thickness control device>
A plate thickness control apparatus according to a first embodiment of the present invention will be described.

  In the plate thickness control apparatus according to the first embodiment of the present invention, the rolled material 1 is an upper and lower work roll 3a whose gap and speed are appropriately adjusted so that a desired thickness is obtained on the exit side of the present apparatus. , 3b. The work rolls 3a and 3b are supported by the backup rolls 4a and 4b so as to reduce the deflection in the roll width direction. The backup rolls 4 a and 4 b are supported by the rolling mill housing 2 and have a structure that can withstand the rolling load of the rolled material 1.

  The gap between the upper and lower work rolls 3 a and 3 b is adjusted by the reduction means 5. There are two types of reduction means 5, one based on electric motor control (referred to as electric pressure reduction) and one based on hydraulic control (referred to as hydraulic pressure reduction), but the latter tends to obtain a high-speed response. In general, hydraulic pressure reduction is often used because a high-speed response is required to control disturbance such as roll eccentricity with a short cycle.

  The rolling load detection means 6 detects the rolling load. As a method for detecting the rolling load, a method of using a load cell embedded between the rolling mill housing 2 and the rolling-down means 5 and directly measuring the rolling load, or a rolling load from the pressure detected by the hydraulic rolling-down means. There is a way to calculate

  The roll speed detector 7 is attached to the work rolls 3a and 3b or the motor shaft that drives the work rolls 3a and 3b, and detects the roll speed. Some can output a pulse corresponding to the roll rotation angle, and may be used to detect the roll rotation angle. If the ratio of the diameters of the work rolls 3a, 3b and the backup rolls 4a, 4b is known, if there is no slip between the work rolls 3a, 3b and the backup rolls 4a, 4b, the rotation speed and rotation angle of the work rolls 3a, 3b The rotation speed and rotation angle of the backup rolls 4a and 4b can be easily obtained.

Next, the roll reference position detector 8 detects the reference position by a proximity switch or the like every time the backup rolls 4a and 4b make one rotation. Alternatively, a pulse generator or the like may be attached to extract a pulse depending on the rotation angle, and the rotation angle itself may be detected, but it is possible to detect at least a reference position for each rotation. FIG. 1 shows the case where the backup rolls 4a and 4b are attached to either or both of them. However, even if the roll reference position detector 8 is not attached, if the rotation angle of the work rolls 3a, 3b is known, the diameter ratio of the work rolls 3a, 3b and the backup rolls 4a, 4b can be determined from the diameter ratio of the backup rolls 4a, 4b. The rotation angle can be calculated from the following equation.

Here, the theta _B, backup roll 4a, the rotation angle of 4b [rad], θ _W is the work rolls 3a, the rotation angle of 3b [rad], _{D B} is the backup roll 4a, 4b with a diameter [mm], D _W is the diameter [mm] of the work rolls 3a and 3b. As described above, the roll reference position detector 8 in FIG. 1 is not essential to the present invention.

  Next, the roll gap detector 9 is installed between the backup rolls 4a and 4b and the reduction means 5, and indirectly detects the gap between the work rolls 3a and 3b.

The rolling load upper and lower distribution means 10 assumes that the rolling load P detected by the rolling load detection means 6 is generated separately for the upper backup roll 4a and the lower backup roll 4b, and the upper backup roll. The rolling load _PT generated in 4 a and the rolling load P _B generated in the lower backup roll 4 b are separated and output to the rolling load vertical fluctuation extracting means 11.

  Next, specific configurations and operations of the rolling load up / down fluctuation extracting means 11 and the operation amount calculating means 12 will be described with reference to FIG.

  FIG. 5 is a block diagram showing in detail a configuration example of the rolling load up / down fluctuation extracting means 11 and the manipulated variable calculating means 12 of the sheet thickness control apparatus according to the first embodiment.

  In FIG. 5, the rolling load up / down fluctuation extracting means 11 includes an upper load fluctuation extracting means 111 and a lower load fluctuation extracting means 112.

Based on the rolling load _PT separated by the rolling load up-and-down distribution unit 10, the upper load fluctuation extracting unit 111 _calculates fluctuation components caused by roll eccentricity of the rolling load _PTj at a plurality of rotational positions of the upper backup roll 4a. To extract.

The lower load fluctuation extraction unit 112 is based on the rolling load P _B separated by the rolling load up-and-down distribution unit 10 and changes due to roll eccentricity of the rolling load P _Bj at a plurality of rotational positions of the lower backup roll 4b. The component is extracted.

  The upper load fluctuation extracting unit 111 includes a rolling load recording unit 111a, an average value calculating unit 111b, and a deviation calculating unit 111c. Similarly, the lower load fluctuation extracting unit 112 includes a rolling load recording unit 112a, an average value calculating unit 112b, and a deviation calculating unit 112c.

The rolling load recording means 111a is n rolling load recording means provided corresponding to the respective rotation angle numbers of the backup rolls 4a and 4b. Each rolling load recording means 111a, backup rolls 4a, 4b is rolling load P _Tj when reaching the rotation angle number corresponding is recorded a predetermined time period.

Based on the rolling load _PTj recorded in each rolling load recording means 111a, the average value calculating means 111b includes n rolling loads _PTj (j = 0) detected while the backup rolls 4a and 4b make one rotation. (N-1)) is calculated.

The deviation calculating means 111c is provided corresponding to each rolling load recording means 111a, respectively, and the deviation ΔP _Tj from the average value of the rolling load _PTj recorded in the corresponding rolling load recording means 111a is calculated as a backup roll. Every time 4a and 4b rotate, it calculates and outputs. The same applies to the rolling load recording means 112a, the average value calculating means 112b, and the deviation calculating means 112c of the lower load fluctuation extracting means 112.

  The operation amount calculation unit 12 includes an upper addition unit 121, a lower addition unit 122, an upper switch 123, a lower switch 124, and a roll gap correction amount calculation unit 125.

The upper addition means 121 adds the fluctuation component due to roll eccentricity of the rolling load _PTj output from the upper load fluctuation extraction means 111 for each rotation angle number.

The lower addition means 122 adds the fluctuation component due to roll eccentricity of the rolling load P _Bj output from the lower load fluctuation extraction means 112 for each rotation angle number.

Upper switch 123 has been added for each rotation angle numbers by an upper adder means 121, the fluctuation component due to roll eccentricity of a rolling load P _Tj, i.e. the upper rolling load variation value of the backup roll 4a which is a deviation of the rolling load P _Tj It is output according to the rotation angle number.

The lower switch 124 backs up the fluctuation component due to roll eccentricity of the rolling load P _Bj added by the lower addition means 122 for each rotation angle number, that is, the lower rolling load fluctuation value that is the deviation of the rolling load P _Bj. This is output according to the rotation angle number of the roll 4b.

  The roll gap correction amount calculation means 125 calculates a roll gap correction amount according to the rotation angle number of the backup rolls 4a and 4b based on the output value of the upper switch 123 and the output value of the lower switch 124. is there.

Here, the upper addition means 121 and the lower addition means 122, and the upper switch 123 and the lower switch 124 have the same configuration. For example, the upper addition means 121 includes a limit 121a, a switch 121b, and an adder 121c. Here, the limit 121a checks the upper and lower limits of the deviation ΔP _Tj input from each deviation calculating means 111c. The switch 121b is turned on every time the upper backup roll 4a makes one revolution, that is, every time the average value calculation means 111b finishes calculating, and simultaneously outputs the deviation ΔP _Tj input from the limit 121a. . The adder 121c is provided corresponding to each rotation angle number of the upper backup roll 4a, and adds a deviation output from the switch 121b for each rotation angle number. The upper switch 123 and the lower switch 124 have the same configuration.

  Next, operations of the rolling load up / down fluctuation extracting means 11 and the operation amount calculating means 12 shown in FIG. 5 will be described.

The rolling load detection means 6 can only collect one value as the rolling load for one stand. Therefore, the rolling load vertical distribution means 10 generates the rolling load P detected by the rolling load detection means 6 by the following formula, for example, by the rolling load _PT generated in the upper backup roll 4a and the lower backup roll 4b. to separated into a rolling load P _B.

here,
P _T : Rolling load generated in the upper backup roll 4a P _B : Rolling load generated in the lower backup roll 4b P: Total rolling load actual value (detected value by the rolling and rolling load detecting means)
R: Ratio of the total rolling load P to be distributed to the rolling load _PT generated in the upper backup roll 4a.

Here, in the first embodiment, as a specific value, the ratio R to the total rolling load P to be distributed to the rolling load _PT generated in the upper backup roll 4a is a value in the vicinity of 0.5, that is, When the total rolling load actual value P is allocated to the rolling load generated in the backup rolls 4a and 4b, a value close to 1/2 of P is allocated to each of the upper and lower sides. Thus, the rolling load fluctuation component due to roll eccentricity or the like by the other backup rolls 4a and 4b can be almost canceled by the upper and lower adders 121c and 122c. The reason for this will be described later.

Next, in the rolling load up / down fluctuation extracting means 11, the rolling load recording means 111a holds the rolling load at the backup roll rotation angle numbers 0, 1, 2,..., N−1 while the upper backup roll 4a makes one rotation. Then, the average value calculation means 111b calculates the average value when the rotation angle number n-1 is reached. And the deviation calculating means 111c is the manipulated variable calculating means 12 with the difference between the rolling load at the backup roll rotation angle numbers 0, 1, 2,..., N−1 and the average value as the rolling load fluctuation due to roll eccentricity or the like. Output to. In this case, instead of taking the difference from the average value, a straight line expression may be calculated from P _{0 at} the start point and P _{n at the} end point, and the difference between the straight line and the rolling load at each position may be calculated.

Rolling load fluctuations due to roll eccentricity at the backup roll rotation angle number are checked with upper and lower limits at the limits 121a and 122a, and when the calculation of the average value is completed, the switches 121b and 122b are simultaneously turned on to determine the deviation of the rolling load. A certain rolling load fluctuation value ΔP ₀ , ΔP ₁ ,..., ΔP _n−1 is sent to adders (Σ ₀ , Σ ₁ , Σ ₂ ,..., Σ _n−1 ) 121 c and 122 c and added together.

here,
Zj: Value of adder Σj
k: Number of additions (generally coincides with the rotation speed of the backup rolls 4a and 4b)
j = 0 to n−1
The adders (Σ ₀ , Σ ₁ , Σ ₂ ,..., Σ _n-1 ) 121c and 122c are cleared to zero before the rolled material 1 is rolled, and the backup rolls 4a and 4b rotate once to calculate an average value. Every time is completed, the deviation of the rolling load is added once. This procedure is performed by the upper addition means 121 and the lower addition means 122.

Switch 123 and 124, respectively, the backup rolls 4a, upper rolling load variation [Delta] P _AT to the rotation angle of 4b which is a deviation of rolling force which is added to correspond to take out the lower rolling load variation [Delta] P _BT.

That is, when the backup roll reference position has passed the reference position 0, which is fixed, only the SW ₀ is ON, [Delta] P _A0 is retrieved from sigma ₀ of the adder 121c. When the backup roll reference position reaches the rotation angle number 1, only SW ₁ is turned ON, and ΔP _A1 is extracted from Σ _{1 of the} adder 121c. This operation is repeated in the switches 123 and 124 of the rolling load fluctuation values due to roll eccentricity corresponding to the backup roll rotation angle.

  Note that the addition at each position can be easily derived from a general control law. That is, as in the case of this control target, when there is no integration system in the control target, it is reasonable from the viewpoint of the control law to insert an integrator on the controller side and remove the steady deviation. Since the controlled object is not a continuous system but a discrete value system, adders 121c and 122c are used instead of integrators.

The upper addition means 121 and the upper switch 123 constituting the operation amount calculation means 12 in FIG. 5 calculate the rolling load deviation (upper rolling load fluctuation value) ΔP _AT by the upper backup roll 4a, while the lower addition means 122. The lower switch 124 calculates a rolling load deviation (lower rolling load fluctuation value) ΔP _BT by the lower backup roll 4b, and the roll gap correction amount calculation means 125 calculates the upper backup roll for the upper backup roll by the following equations 6 and 7. and low gap correction amount [Delta] S _T, calculates a lower row the gap correction amount for side backup roll [Delta] S _B.

The roll gap correction amount [Delta] S is a manipulated variable, since the roll gap can not be vertically separately operated, the roll gap correction amount calculating means 125, as in the following equation 8, and the upper and lower rows gap correction amount [Delta] S _T, Add ΔS _B and output.

here,
M: Mill constant
Q: Plasticity factor of rolled material
K _T : Adjustment coefficient
ΔS _T: for the upper backup roll low gap correction amount
ΔS _B: low gap correction amount for the lower backup roll
ΔS: Low gap correction amount
ΔP _AT : Rolling load deviation due to upper backup roll (upper rolling load fluctuation value)
ΔP _BT : Deviation of rolling load by lower backup roll (lower rolling load fluctuation value)
Then, the roll gap operation means 13 gives the low gap correction amount ΔS according to the equation 8 to the reduction means 5 in addition to the roll gap amount such as MMC or GM-AGC.

Next, the validity of setting the ratio R to the total rolling load P to be distributed to the rolling load _PT generated in the upper backup roll 4a as a value in the vicinity of 0.5 will be described.

Assuming that the rotation frequencies of the backup rolls 4a and 4b are ω _T and ω _B [rad / s] and the rotation periods are T _T and T _B [s],

Further, r is a ratio represented by the following formula 10.

Here, it is assumed that D _T <D _B , that is, r <1. However, this assumption does not limit the validity of setting R to a value in the vicinity of 0.5, and r> 1 may be used. This is for convenience of explanation.

Assuming that the roll eccentric amounts of the backup rolls 4a and 4b are y ₁ and y ₂ [mm], the phase difference is θ _2, and the amplitude is 1.0 for simplicity, the following equation 11 can be written.

  Hereinafter, although it considers with an axial center moving distance, since an axial center moving distance is directly linked with the fluctuation | variation of a rolling load, it can also consider replacing with a rolling load fluctuation | variation.

  Next, the relationship of Equation 11 is shown in FIG.

FIG. 6 is a diagram illustrating an example of temporal changes in roll eccentric amounts y ₁ and y ₂ [mm] of the backup rolls 4a and 4b.

When the time when the upper backup roll rotation angle starts from the fixed reference position and reaches the rotation angle number j (j = ₀ to n−1) is T ₀ , T ₀ is expressed by the following equation.

The value accumulated in the upper roll adder 121c is the integrated value Y _T (j) of the axial movement amount of the upper backup roll 4a at the position j of the upper backup roll 4a and the lower value at the position j of the upper backup roll 4a. This is the sum of the integrated values Y _B (j) of the amount of axial movement of the side backup roll 4b. Since Y _T (j) is an integrated value of the period T _T with T ₀ as an initial value, it is calculated by the following equation (13).

Similarly, Y _B (j) is also an integrated value of the period T _T with T ₀ as an initial value, and is therefore calculated by the following equation 14 and more specifically by the following equation 15.

here,

Assuming that an integer m can be determined, substituting equation 16 into equation 15, equation 15 becomes the following equation 17.

Here, the integrated value of sin of the angle obtained by multiplying the full-angle 2π [rad] of the circle by −1 / n and adding to α is zero. That is, every time m sin values are integrated, the integrated value Y _B (j) of the axial movement amount of the lower backup roll 4b becomes zero.

In Expression 16, 1 / (1-r) is not necessarily an integer depending on the ratio of the diameters of the backup rolls 4a and 4b, but when 1 / (1-r) is a value close to an integer, Y _B (j) becomes a value close to zero each time the sin value is integrated.

Further, here, the beat Y, which is a superposition of y ₁ and y ₂ , is expressed by the following Expression 18 as in Expression 1.

In the case of ω _T > ω _B , the long period frequency (ω _T −ω _B ) / 2 is T _B = T _T / r,

It becomes.

That is, m in Equation 16 gives the beat long cycle m · T _T, and the integrated value Y _B (j) of the axial movement amount of the lower backup roll 4b becomes zero for each m · T _T.

Further, from Equation 13, the integrated value Y _T (j) of the axial center movement amount of the upper backup roll 4a is monotonously increased without the roll eccentricity control, and the lower backup roll 4a rotates each time the upper backup roll 4a rotates. Since the specific gravity of the integrated value Y _B (j) of the axis 4 of the roll 4b with respect to Y _T (j) decreases, the upper roll eccentricity of the upper backup roll 4a is added to the upper roll adder 121c shown in FIG. The components are mainly accumulated.

  Based on the same idea, the roll eccentric component of the lower backup roll 4b is mainly accumulated in the lower roll adder 122c.

Accordingly, the ratio R to the total rolling load P to be allocated to the upper rolling load _PT is a value in the vicinity of 0.5, that is, when the total rolling load actual value P is allocated to the rolling load generated in the backup rolls 4a and 4b. It can be seen that a value close to ½ of P may be distributed vertically.

  As described above, according to the plate thickness control apparatus of the first embodiment, roll rotation, such as roll eccentricity, is performed using a rolling load measured during rolling of a metal material without using a kiss roll load. The rolling load fluctuation component generated in relation to the position, that is, the rolling load fluctuation component due to roll eccentricity or the like is extracted, and the roll gap of the rolling stand can be manipulated so as to reduce the rolling load fluctuation.

  Thereby, according to the board thickness control apparatus of 1st Embodiment, when there exists fluctuation | variation of the rolling load by roll eccentricity etc., the rolling load fluctuation | variation can be suppressed and the board thickness fluctuation | variation by rolling load fluctuation | variation can be suppressed. Can control variable components that can not be analyzed by frequency analysis when not rolling, no thickness gauge is required, and there is no deterioration in accuracy due to tracking errors, and even if there is a difference in diameter between the backup rolls 4a and 4b, high accuracy In addition, there is no need to measure the kiss roll load. As a result, according to the plate thickness control device of the embodiment, it is possible to provide a high-precision plate thickness control device, plate thickness control method, and plate thickness control program that facilitates roll management and that does not have equipment restrictions. .

In particular, according to the plate thickness control apparatus of the first embodiment, the ratio R to the total rolling load P to be distributed to the rolling load _PT generated on the upper backup roll 4a is set to a value in the vicinity of 0.5. Therefore, when the total rolling load actual value P is allocated to the rolling load generated in the backup rolls 4a and 4b, a value close to 1/2 of P is allocated to each of the upper and lower sides. The rolling load fluctuation components due to roll eccentricity by the other backup rolls 4a and 4b can be almost canceled by the vessels 121c and 122c.

(Second Embodiment)
After the backup rolls 4a and 4b have sufficiently rotated, the adders 121c and 122c in the upper addition means 121 and the lower addition means 122 in FIG. 5 correspond to the eccentricity of the upper backup rolls 4a and 4b. It is clear that the accumulated value is accumulated.

  That is, the fact that a large value is stored in the j-th adder 121c means that the eccentricity amount at the j-th position is large. The same applies to the lower adder 121c.

  Therefore, in the plate thickness control apparatus according to the second embodiment of the present invention, after this, after the backup rolls 4a and 4b have sufficiently rotated, the values of the upper and lower adders 121c and 122c, that is, the upper and lower The roll eccentricity of each backup roll 4a, 4b is identified, and the frequency and period of roll eccentricity are calculated from the rotational speed based on this.

  FIG. 7 is an explanatory diagram showing a change in the value stored in the adder 121 c of the upper addition means 121.

  In FIG. 7, the horizontal axis represents the number of the adder in the adder 121c, the vertical axis represents the value of each adder in the adder 121c, the value 201 (bar graph) of each adder in the adder 121c, and each position. The sine wave 202 identified from the addition value in FIG.

  Each adder 121c may include noise or the like, and a sine wave can be obtained by a least square method or the like.

  Then, the operation amount calculation means 12 uses the load value stored in the adder 121c to calculate the upper work roll 3a and the lower work using the equation 8 for converting the load into the roll gap according to the second embodiment. The work roll gap command value between the roll 3b is calculated, and the roll gap operation means 13 is based on the work roll gap command value calculated by the operation amount calculation means 12, and the upper work roll 3a and the lower work roll 3b Manipulate the work roll gap between.

  As described above, according to the plate thickness control apparatus of the second embodiment, the rolling load measured during the rolling of the metal material can be obtained without using the kiss roll load, similarly to the first embodiment. The rolling stand is used to extract the rolling load fluctuation component generated in relation to the roll rotation position, such as roll eccentricity, that is, the rolling load fluctuation component due to roll eccentricity, etc., and to reduce the rolling load fluctuation. The roll gap can be manipulated.

In particular, in the plate thickness control apparatus of the second embodiment, after the backup rolls 4a and 4b have sufficiently rotated, the values of the upper and lower adders 121c and 122c, that is, the upper and lower backup rolls 4a and 4b, respectively. Roll eccentricity amount can be identified, and since the frequency and cycle of roll eccentricity are calculated from the rotational speed of the backup rolls 4a and 4b, the frequency and cycle of roll eccentricity can be easily obtained, The roll gap of the rolling stand can be manipulated so as to reduce the rolling load fluctuation, and the ratio R to the total rolling load P to be distributed to the upper rolling load _PT is set to a value in the vicinity of 0.5. Since the total rolling load actual value P is distributed to the rolling load generated in the backup rolls 4a and 4b, A value close to ½ is allocated to each of the upper and lower sides, and the rolling load fluctuation component due to roll eccentricity or the like by the other backup rolls 4a and 4b can be almost canceled by the upper and lower adders 121c and 122c. .

(Third embodiment)
In the third embodiment of the present invention, immediately after replacement of the backup rolls 4a and 4b, R, which is a ratio to the total rolling load P to be distributed to the upper rolling load _PT , is set to 0.5, but the backup roll 4a , 4b after sufficient rotation, for example, after rolling one rolled material, the upper and lower backup rolls 4a, 4b roll eccentricity amount is a periodic function such as a sine wave as described above. Therefore, the ratio of the amplitude of the sine wave after the identification of the backup rolls 4a and 4b is used as the ratio of the next material as R.

  For example, as a result of rolling immediately after replacement of the backup rolls 4a and 4b, the amplitude of the sine wave identified by the adder 121c of the upper backup roll 4a is 0.9, and the amplitude of the sine wave identified by the adder 121c of the lower backup roll 4b Is 1.1, the ratio R = 0.9 / (0.9 + 1.1) = 0.45 can be used for the next material.

  Moreover, the ratio of the roll eccentricity of the backup rolls 4a and 4b can be obtained by calculating the absolute value of the value stored in the addition without identifying with a periodic function. For example, as a result of rolling immediately after replacement of the backup rolls 4a and 4b, the absolute value of the values at the respective positions of the backup rolls 4a and 4b of the adder 121c of the upper backup roll 4a is, for example, 9.0. If the result of adding the absolute values of the values at the respective positions of the backup rolls 4a and 4b of the adder 121c of 4b is 11.0, for example, the ratio R = 9 / (9 + 11) = 0.45 is used as the next material. Can be used.

That is, in the third embodiment, the rolling load up / down distribution means 10 sets the ratio R for distributing the rolling load detected by the rolling load detection means 6 up and down to 0.5 immediately after the backup roll replacement, After the replacement of the backup roll, after the next rolled material, the periodic function is calculated using the integrated values of the upper and lower rolling load fluctuation values ΔP _AT and ΔP _BT which are deviations of the rolling load in the operation amount calculation means 12 for the current rolled material. The amplitude may be identified, and the ratio of the amplitude for the upper work roll 3a and the upper back-up roll 4a and the sum of the amplitudes for the lower work roll 3b and the lower back-up roll 4b may be set, or rolling The ratio R for allocating the rolling load detected by the load detecting means 6 up and down is set to 0.5 immediately after the backup roll replacement, After the exchange of the roll-up roll, after the next rolled material, it may be set based on rolling load fluctuation values ΔP _AT and ΔP _BT which are deviations of the rolling load in the operation amount calculation means 12 of the current rolled material.

Of course, since this ratio may contain noise, it is also possible to reduce the influence of noise by using a filter as shown in the following equation (20).

Here, in Equation 20,
k: an index indicating the present k + 1: an index indicating that it should be used next time k-1: an index indicating one time before the present c: a gain for filtering.

As described above, according to the plate thickness control apparatus of the third embodiment, a metal material is measured during rolling without using a kiss roll load, as in the first and second embodiments. The rolling load can be used to extract the rolling load fluctuation component generated in relation to the roll rotation position, such as roll eccentricity, and to operate the roll gap of the rolling stand so as to reduce this rolling load fluctuation. In addition, immediately after the replacement of the backup rolls 4a and 4b, R, which is a ratio to the total rolling load P to be distributed to the upper rolling load _PT , is set to a value in the vicinity of 0.5. When P is allocated to the rolling load generated in the backup rolls 4a and 4b, a value close to 1/2 of P is allocated to each of the upper and lower sides, and one of the upper and lower adders 121c and 122c. The rolling load fluctuation component due to roll eccentricity by the other backup rolls 4a and 4b can be almost canceled.

In particular, in the plate thickness control apparatus according to the third embodiment of the present invention, immediately after replacement of the backup rolls 4a and 4b, R, which is a ratio to the total rolling load P to be distributed to the upper rolling load _PT , is 0.5. After the backup rolls 4a and 4b are sufficiently rotated, for example, after rolling one rolled material, the roll eccentricity of the upper and lower backup rolls 4a and 4b is set to the value of the upper and lower adder 121c group. Since it can be identified by a periodic function such as a sine wave, the ratio of the amplitude of the sine wave after identification of the backup rolls 4a and 4b can be used as the ratio of the next material, and roll eccentricity can be easily performed. And the roll gap of the rolling stand can be manipulated so as to reduce rolling load fluctuations.

DESCRIPTION OF SYMBOLS 3 ... Work roll 3a ... Upper work roll 3b ... Lower work roll 4 ... Backup roll 4a ... Upper backup roll 4b ... Lower backup roll 5 ... Lowering means 6 ... Rolling load detection means 7 ... Roll rotation speed detector 8 ... Roll Reference position detector 9 ... Roll gap detector 10 ... Rolling load vertical distribution means 11 ... Rolling load vertical fluctuation extraction means 12 ... Manipulation amount calculation means 13 ... Roll gap operation means

Industrial applicability

  The present invention can be applied to a hot rolling apparatus for rolling a metal material hot.

Claims (6)

Controls the thickness variation of the rolled material produced by rolling the metal material between the upper roll set of the upper work roll and the upper backup roll and the lower roll set of the lower work roll and the lower backup roll. A plate thickness control device,
Rolling load detection means for detecting a rolling load on the metal material;
The rolling load detected by the rolling load detection means is increased or decreased based on the ratio of the upper rolling load generated in the upper roll set and the lower rolling load generated in the lower roll set. Rolling load up and down distribution means to distribute,
Based on the rolling load of the upper roll set and the lower roll set distributed up and down by the rolling load vertical distribution means, the upper side generated in relation to the rotational position of the upper roll set and the lower roll set Rolling load vertical fluctuation value extracting means for extracting rolling load fluctuation value and lower rolling load fluctuation value;
A work roll gap command value between the upper work roll and the lower work roll is calculated based on the upper rolling load fluctuation value and the lower rolling load fluctuation value extracted by the rolling load vertical fluctuation value extracting means. An operation amount calculation means to perform,
Roll gap operating means for operating a work roll gap between the upper work roll and the lower work roll based on the work roll gap command value calculated by the operation amount calculating means;
A plate thickness control device comprising: In the board thickness control device according to claim 1,
The operation amount calculation means includes
Until the upper roll set and the lower roll set rotate for a predetermined time or more, based on the upper rolling load fluctuation value and the lower rolling load fluctuation value extracted by the rolling load vertical fluctuation value extraction means, Calculate the work roll gap command value between the work roll and the lower work roll,
When the upper roll set and the lower roll set are rotated for a predetermined time or more, the upper backup roll and the lower backup are based on an integrated value of the rolling load fluctuation value calculated by the rolling load up / down fluctuation value extracting means. identified roll eccentricity of the roll, calculating the work roll gap command value between the lower work roll and the upper work roll on the basis of the identified roll eccentricity,
Thickness control device characterized by the above. In the plate thickness control apparatus according to any one of claims 1 and 2,
The rolling load vertical distribution means is:
The ratio of distributing the rolling load detected by the rolling load detection means up and down is set to 0.5 immediately after the upper backup roll and the lower backup roll are replaced, and the upper backup roll and the lower backup roll are replaced. After the next rolled material is set based on the deviation of the rolling load in the operation amount calculation means of the current rolled material,
Thickness control device characterized by the above. In the plate thickness control apparatus according to any one of claims 1 and 2,
The rolling load vertical distribution means is:
The ratio of distributing the rolling load detected by the rolling load detection means up and down is set to 0.5 immediately after the upper backup roll and the lower backup roll are replaced, and the upper backup roll and the lower backup roll are replaced. Then, after the next rolled material, the amplitude of the periodic function is identified using the integrated value of the rolling load fluctuation value in the operation amount calculation means of the current rolled material, the amplitude for the upper roll set, and the lower roll set Set the ratio of the sum to the amplitude to
Thickness control device characterized by the above. Controls the thickness variation of the rolled material produced by rolling the metal material between the upper roll set of the upper work roll and the upper backup roll and the lower roll set of the lower work roll and the lower backup roll. A plate thickness control method,
Detecting a rolling load on the metal material;
Distributing the detected rolling load up and down based on the ratio of the upper rolling load generated in the upper roll set and the lower rolling load generated in the lower roll set;
Based on the rolling load of the upper roll set and the lower roll set distributed above and below, the upper rolling load fluctuation value generated in relation to the rotational position of the upper roll set and the lower roll set and the lower Extracting a side rolling load fluctuation value;
Based on the extracted upper rolling load fluctuation value and lower rolling load fluctuation value, calculating a work roll gap command value between the upper work roll and the lower work roll;
Based on the calculated work roll gap command value, operating a work roll gap between the upper work roll and the lower work roll;
A sheet thickness control method comprising: Controls the thickness variation of the rolled material produced by rolling the metal material between the upper roll set of the upper work roll and the upper backup roll and the lower roll set of the lower work roll and the lower backup roll. A thickness control program for causing a computer to execute
Detecting a rolling load on the metal material;
Distributing the detected rolling load up and down based on the ratio of the upper rolling load generated in the upper roll set and the lower rolling load generated in the lower roll set;
Based on the rolling load of the upper roll set and the lower roll set distributed above and below, the upper rolling load fluctuation value generated in relation to the rotational position of the upper roll set and the lower roll set and the lower Extracting a side rolling load fluctuation value;
Based on the extracted upper rolling load fluctuation value and lower rolling load fluctuation value, calculating a work roll gap command value between the upper work roll and the lower work roll;
Based on the calculated work roll gap command value, operating a work roll gap between the upper work roll and the lower work roll;
Thickness control program for causing a computer to execute.

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