JP5734112B2 - Thickness control method in rolling mill - Google Patents

Description

  The present invention relates to a plate thickness control method in a rolling mill.

When rolling a rolled material using a rolling mill, it is necessary to accurately control the thickness of the rolled material. The plate thickness is one of the evaluation criteria for the final product in the rolling mill, and various control technologies (plate thickness control technologies) have been developed to make the plate thickness appropriate.
In these plate thickness control technologies, the roll gap of the rolling roll is predicted using a gauge meter type, and the rolling roll of the rolling mill is set up so as to satisfy the predicted roll gap, and the rolling roll during rolling is set. The thickness of the rolled material is controlled.

Patent Document 1 uses a gauge meter plate thickness model obtained by correcting the above-mentioned gauge meter formula to set the work side and drive side reduction positions independently, and the plate thickness at both ends in the plate width direction of the rolled material is the target. A plate thickness control method for controlling to be a value is disclosed.
In the sheet thickness control method disclosed in Patent Document 1, the reduction positions of the work side and the drive side of the rolling mill are independently set so that the sheet thickness at both ends in the sheet width direction of the sheet material satisfies a predetermined target value. In setting, the relationship between the deformation amount of the work side and drive side housing with respect to the total rolling load, the deformation amount of the center position of the work roll cylinder and the amount of plate crown, the diameter of each roll at the center position of the work roll and backup roll cylinder The work side and drive side reduction positions are respectively set using a gauge meter plate thickness model of a plate thickness profile in the plate width direction, which is composed of a change amount and a correction amount for the plate thickness at both ends of the plate width.

  By the way, in the rolling process, for example, when the heating state of the rolled material (particularly the heating bias, that is, the biased heat) changes, the rolling load difference changes between the work side and the drive side, and the estimated value of the rolling load difference inevitably. An error occurs. Since this error reduces the accuracy of sheet thickness control, it is difficult to accurately estimate the reduction positions on both the work side and the drive side using the estimated value of the rolling load difference.

  Therefore, the sheet thickness control method disclosed in Patent Document 1 does not use the estimated value of the rolling load difference, but rolls such as the sheet thickness at the center of the sheet width, the sheet crown, the work side and the drive side housing deformation amount. The asymmetry of the machine is calculated. After that, based on these calculated plate thickness, plate crown, asymmetry, and total rolling load, calculate the plate thickness at both ends of the rolled material, and set the rolling side work side and drive side reduction positions respectively. It is set independently.

  In this way, the thickness of both ends of the rolled material can be controlled using the total rolling load without using the rolling load difference, which has been indispensable up to now and has been a factor causing errors.

JP 2000-254720 A

As described above, in the plate thickness control method disclosed in Patent Document 1, the gauge meter plate thickness is calculated using the total rolling load, and rolling is performed so that the plate thicknesses at both ends in the plate width direction of the rolled material become target values. The work side and drive side reduction positions of the machine are set independently.
However, setting the work side and drive side reduction positions independently means that the zero adjustment of the reduction position accompanying switching of the rolling rolls, as well as the left-right asymmetry in the width direction of the rolling rolls caused by roll wear and thermal crown It is difficult to perform accurately because it is affected by the roll shift depending on the nature.

Due to these effects, the plate thickness control method disclosed in Patent Document 1 lacks the reliability of the leveling measurement value, which is the difference in the reduction position between the work side and the drive side, and the accuracy of the plate thickness control decreases. Has the problem. In the first place, if Δs representing the difference in the reduction position and the difference between the left and right roll gaps is used, the accuracy of the plate thickness control decreases as described later.
Therefore, in view of such a problem, the present invention provides a plate thickness control method for controlling the plate thickness while reliably preventing the plate thickness of the end portion on the thin side from falling below the target value in the rolled material having a wedge. The purpose is to do.

In order to achieve the above-described object, the present invention takes the following technical means.
The sheet thickness control method in the rolling mill of the present invention is a sheet thickness control method for a rolled material that is being rolled by a rolling mill equipped with a work roll, and a rolling load difference that is a difference in rolling load at both ends in the width direction of the work roll. and ([Delta] P), a wedge amount is a plate thickness difference in the width direction at both ends of the rolled material, by using the entry side wedge amount ([Delta] H _W) is a wedge amount in the work roll entry side, the work Calculate the exit side wedge amount (Δh _W ) that is the amount of wedge on the roll exit side, and use the calculated exit side wedge amount (Δh _W ) to determine the plate end that is the thickness of the end portion in the width direction of the rolled material Based on the obtained plate end thickness (h _G ) and gauge meter formula, the roll gap (s) of the work roll is obtained, and the obtained roll gap is applied to a rolling mill for rolling. The thickness of the material is controlled.

Furthermore, in the above-described sheet thickness control method, the center sheet thickness of the rolled material is calculated from the sheet thickness h _C at the center in the width direction of the rolled material obtained by a gauge meter method and the sheet crown Δh _{Cr of the} rolled material, The plate thickness (h _G ) at the plate end may be obtained by adding the exit side wedge amount Δh _W to the calculated center plate thickness (h _C + Δh _Cr ).
Such technical means in the present invention have been taken by the inventors of the present invention after obtaining the knowledge described below.

That is, the inventor of the present application, as shown in the gauge meter formula of Formula (1), shows the mill elongation h _C or the plate crown representing the rigidity of the rolling mill constituting the conventional gauge meter formula for determining the center plate thickness of the rolled material. In addition to terms such as the minute Δh _Cr , if the plate wedge portion Δh _W , which has not been studied in the past, is considered as an element for adjusting the accuracy of the gauge meter type, the accuracy of the gauge meter type can be improved. I have learned that I can do it. Note that the plate thickness h _C at the center in the width direction of the rolled material is calculated from the set gap, the elongation associated with the mill rigidity of the rolling mill, the thermal crown, and the amount of crown wear of the work roll.

As shown in FIG. 3, the actual shape of the rolled material is a shape in which a plate wedge that is asymmetric in the width direction and a plate crown that is symmetric are combined.
The plate wedge indicates that the plate thicknesses at both ends of the rolled material in the width direction of the work roll are different from each other, and the plate thickness distribution of the rolled material is asymmetric with respect to the center in the width direction. , Material factors, and measurement factors.

The mill factor is the difference between the left and right mill constants during normal rotation and reverse rotation, the asymmetry of the roll profile due to thermal, wear, and shift, the oblique incidence of rolling material, camber, and side guide due to side guides. It is a factor affected by off-center and work roll leveling.
The material factor is a factor that is influenced by uneven heat of the rolled material, a plate wedge on the work roll entrance side of the rolled material, and the like.

The measurement factor is a factor that is influenced by the γ-ray measurement position, such as a measurement abnormality of the γ-ray and a plate off-center during measurement.
Of these factors, considering the mill factors and material factors that are directly related to rolling, the plate wedge portion Δh _W , which is a term indicating the asymmetry of the rolled material, is assumed as shown in Equation (2). Can do.

As a result, the inventor of the present application added a plate that is an asymmetric term to a conventional gauge meter type that is composed of only a symmetric term on the assumption that the thickness distribution of the rolled material is symmetric with respect to the center in the width direction. The present invention was completed by adding the wedge amount Δh _W.

  According to the plate thickness control method according to the present invention, in a rolled material having a wedge, the plate thickness can be controlled while reliably preventing the plate thickness of the end portion on the thin side from falling below the target value.

It is the schematic which shows the structure of the rolling apparatus by embodiment of this invention. It is explanatory drawing of the shape of the rolling material by embodiment of this invention. It is a figure which shows the flowchart of the board thickness control method by embodiment of this invention. Is a diagram showing a histogram representing the prediction error of the thickness h _G of the plate edge in the model A~ model C according to an embodiment of the present invention, (a) shows the histogram of model A, the (b) Model B histogram, ( c) shows the histogram of model C. It is a figure which shows the structure used as the premise which derives | leads-out the model A-model C by embodiment of this invention.

Hereinafter, a rolling mill to which a sheet thickness control method according to an embodiment of the present invention can be applied will be described.
FIG. 1 is a diagram illustrating a sheet thickness control method and a rolling apparatus of a rolling mill according to an embodiment of the present invention.
As shown in FIG. 1, the rolling device 1 is for rolling a thick steel plate or a thin steel plate, and includes a rolling mill 4 and a control unit 9 that controls the rolling mill 4.

  The rolling mill 4 includes a work roll 2 through a pair of upper and lower work rolls 2 and 2, a pair of backup rolls 3 and 3 that support the work rolls 2 and 2, and an upper backup roll 3. There are gap changing means for making the roll gap variable, and load measuring means for measuring and outputting the rolling load. The gap changing means is constituted by a hydraulic cylinder 6, and the load measuring means is constituted by a load cell 10 or the like.

  The gap changing means can independently drive the chock portions 11 that support both ends of the work roll 2. One end side of the work roll 2 is connected to a drive motor that drives the work roll 2 and is a drive side. The other end side of the work roll 2 is not connected to a drive motor, and is a work side in which a space for an operator to work is secured.

Since the structure of the chock part 11 and the framework of the rolling mill 4 that supports the chock part 11 are largely different depending on whether the drive motor is connected or not, the rigidity (mill rigidity) of the rolling mill 4 differs between the drive side and the work side. It has become.
A rolling material 5 serving as a base plate is introduced into the rolling mill 4 and subjected to rolling, and then sent to a lower process. An entry side thickness gauge 7 for measuring the entry side thickness H of the rolled material 5 is installed on the entry side of the rolling mill 4, and an exit side thickness h of the rolling material 5 is measured on the exit side of the rolling mill 4. A side plate thickness gauge 8 (not shown) is installed. As the entrance side thickness gauge 7 and the exit side thickness gauge 8, a γ-ray thickness gauge or the like can be employed.

In addition, when there is no space for providing the entrance side thickness gauge 7, the exit side thickness of the rolling mill in the upper process can be adopted as the entry side thickness.
Furthermore, the rolling device 1 is provided with a control unit 9 that controls the rolling load P and the roll gap amount s of the rolling mill 4.
The control unit 9 has a plate thickness control function for controlling the rolling mill 4 so that the outlet side plate thickness h of the rolled material 5 falls within a predetermined range or is constant. As a control method performed in the control unit 9, a plate thickness control method according to the present invention to be described later is adopted, but other known methods can be adopted, and feedforward AGC, BISRA AGC, monitor AGC, mass flow can be adopted. AGC, tension AGC, etc. are applicable. Information such as the entry side plate thickness H, rolling load P, and rolling material tension of the rolling mill 4 is input to the control unit 9, and the roll gap amount s and roll speed of the rolling mill 4 are based on the input information. Is calculated and output.

The control unit 9 described above is realized by a process computer or PLC.
Hereinafter, the sheet thickness control method of the rolling mill 4 performed by the control unit 9 of the present embodiment will be described with reference to FIGS.
In the plate thickness control method according to the present embodiment, the plate width cross-sectional shape that is the cross-sectional shape in the plate width direction of the rolled material 5 is an asymmetrical cross-sectional shape that is an actual cross-sectional shape as shown in FIG. This is particularly beneficial for (shape).

  However, the gauge meter formula (formula (3)) conventionally used is established on the premise that the cross-sectional shape of the strip width on the exit side of the rolled material 5 is bilaterally symmetric. Using the rolling load P, the relationship between the outlet side thickness h at the center of the plate width and the roll gap s for obtaining the outlet side thickness h at the center of the plate width is shown.

When the exit side plate thickness h at the center of the plate width is referred to as the center plate thickness h _C in the following description, Equation (3) can be rewritten as Equation (4).

However, the cross-sectional shape of the actual rolled material 5 is affected by the deflection of the work roll 2 and the like. As a result, the actual rolled material 5 also includes a shape component Δh _Cr called a plate crown in which the plate thickness increases from the end portion (plate end) in the plate width direction toward the center of the plate width. Correct to (h _C + Δh _Cr ).
In this way, by adding the plate crown component Δh _Cr to the central plate thickness hc shown in the equation (4), the plate width in the left-right symmetric shape shown as “gauge meter type + plate crown” in FIG. The center delivery thickness (h _C + Δh _Cr ) can be predicted.

If the sheet width cross-sectional shape of the rolled material 5 is bilaterally symmetric as described above, the roll gap of the rolling mill 4 can be predicted by the center thickness (h _C + Δh _Cr ) on the outlet side and the gauge meter formula. The thickness of the plate edge of the rolled material 5 can be predicted and compensated based on the central plate thickness.
However, the actual sheet width cross-sectional shape of the rolled material 5 is “wedge shape in which the thickness of one plate end is thinner than the thickness of the other plate end” as shown as “plate wedge” in FIG. It contains asymmetrical components.

That is, the rolled material 5 has a left-right asymmetric shape (actual rolling shape) as shown in FIG. 2 as a shape combining a left-right asymmetric component such as a plate wedge shape and a left-right asymmetric component such as a plate crown shape. May have.
In such an actual rolling shape that is not symmetrical, when the rolling mill 4 is controlled by applying the center thickness (h _C + Δh _Cr ) on the outlet side to the gauge meter type, one of the rolled material 5 is controlled. There may be a problem that the thickness of the end of the plate becomes smaller than the target (predicted) thickness. In order to avoid this problem, at present, the thickness is larger than the center thickness (h _C + Δh _Cr ) on the exit side, that is, the roll gap of the work rolls 2 and 2 corresponding to the predicted thickness. The actual roll gap is increased and the rolled material 5 is rolled thicker.

Therefore, the plate thickness control method according to the present embodiment includes the center plate thickness (h _C + Δh _Cr ) and the amount of “plate wedge” (the amount of the outgoing plate wedge Δh _W ) as shown in the equation (5). by modifying the center thickness, it obtains the thickness h _G of the plate end with a plate thickness of the end portion in the plate width direction.

If the roll gap obtained by the gauge meter type using the plate thickness h _G of the plate end is applied to the rolling mill 4 by reflecting the plate wedge portion Δh _W in the plate thickness h _G of the plate end in this way, the rolled material 5 It is possible to control the thickness of the plate end of the sheet, and it is possible to avoid the problems of the plate thickness control by the conventional gauge meter type.
In addition, the plate thickness h _G obtained by the equation (5) is obtained by adding the plate wedge Δh _W to the plate thickness (h _C + Δh _Cr ) at the center of the plate width, and predicting the actual thickness of the plate end. it seems to do.

By the way, the cause of the left-right asymmetric component, in other words, the factors affecting the output side plate wedge Δh _W are the difference in mill constant (f ₁ ) between the drive side and the work side with respect to the total load in the rolling mill 4, the rolling mill. 4, the load difference (f ₂ ) between the drive side and the work side at 4, the entry side wedge (f ₃ ) which is the difference between the left and right plate thicknesses at the entry side of the rolled material 5 into the rolling mill 4, the drive side of the work roll 2 and the work A leveling amount (f ₄ ) that is a difference between the rolling positions on the side, a roll profile that is the shape of the work roll 2, and a heat deviation of the rolled material 5 (f ₅ ) are assumed.

Therefore, Equation (6) can be assumed as the exit side plate wedge Δh _W.

The inventor of the present application, through various experiments and considerations, among these elements, the left and right load difference (f ₂ ) and the entry side wedge (f ₃ ) are important elements for controlling the exit side plate wedge Δh _W. I came to know that there was.
Therefore, equation (6) was approximated to obtain equation (7).

The formula (8) specifically shows the formula (7).
Equation (8) is a model that expresses the exit side plate wedge Δh _W using the left-right load difference ΔP of the rolling mill 4 and the entry side wedge ΔH _W of the rolled material 5, and hereinafter, equation (8) is expressed as model A And Details of the derivation of model A will be described later. Note that this ΔH _W may be measured using the entry side thickness gauge 7, and the exit side thickness of the rolling mill in the upper process may be employed. The left-right load difference ΔP can be measured using load measuring means.

The exit side plate wedge Δh _W is predicted by the model A expressed by the equation (8), and the estimated exit side plate wedge Δh _W is applied to the equation (5) to calculate the plate thickness h _G of the plate end. The plate thickness h _G of the obtained plate-end delivery side thickness h of the gauge meter equation of formula (3), or when applied to the plate thickness h _C in equation (4) can guide the roll gap s. Needless to say, the roll gap s derived at this time is the roll gap at the center position of the work rolls 2 and 2.

The roll gap s thus guided is applied, and the controller 9 adjusts the roll gap between the work rolls 2 and 2.
Here, the above-described operation of the control unit 9 will be described with reference to the flowchart of FIG.
First, in S1, the control unit 9 calculates a rolling load difference ΔP (ΔP = | P1−P2 |) from the work-side rolling load P1 and the drive-side rolling load P2 detected by the load cell 10 while rolling. The entrance side wedge ΔH _W is acquired by the entrance side thickness gauge 7.

In addition, by calculating the rolling load difference ΔP using the rolling loads P1 and P2 measured in this way, it is possible to perform control with higher accuracy than using the rolling load difference ΔP predicted at the time of setup calculation. Become.
Next, in S2, the exit side plate wedge Δh _W is calculated by the model A shown in the equation (8).
In S3, the calculated exit side plate wedge Δh _W is applied to the equation (5) to calculate the plate thickness h _G of the plate end.

In S4, by applying the plate thickness h _G of the plate end delivery side thickness h of the gauge meter equation of formula (3), or the plate thickness h _C in equation (4), calculates the roll gap s.
In S5, the calculated roll gap s is applied to the rolling mill 4, and the roll gap between the work rolls 2 and 2 is adjusted. At this time, it is preferable that the amount of reduction on the work side and that on the drive side be the same while interlocking. However, it is also possible to independently control (for example, increase) the amount of reduction corresponding to the end portion on the thick side of the rolled material as long as the calculated roll gap s is maintained without causing the meander of the rolled material. .

Thus to calculate the plate wedge Delta] h _W out adopts a model A shown in Equation (8), by obtaining the thickness h _G of the plate end by using the calculated delivery side wedge Delta] h _W, rolled shape asymmetrical It is possible to control the thickness of the plate end of the rolled material 5 having the following.
Next, the effect of the thickness control method of the present invention will be described with reference to FIG.
As described above, the sheet thickness control method of the present invention predicts the exit side wedge Δh _W using the model A (equation (8)), and applies the predicted exit side wedge Δh _W to the equation (5) to obtain the center. The plate thickness h _G was obtained by correcting the plate thickness (h _C + Δh _Cr ). For comparison and verification, the input side wedge ΔH _W and the left and right sides as shown in Equation (9) A prediction model (model B) of the exit side plate wedge Δh _W based on the leveling amount Δs which is a roll gap difference was considered. Here, with respect to the mill constant M, assuming that there is no difference between the mill constant M ₁ on the left and right sides of the rolling roll and the mill constant M ₂ on the other side, or sufficiently small, M = M ₁ = M ₂ To do.

Further, a prediction model (model C) of the outlet plate wedge Δh _W based on the left-right load difference ΔP and the leveling amount Δs as shown in the equation (10) was considered.

Figure 4 shows the prediction error of the thickness h _G of the plate end predicted based on plate wedge Delta] h _W out obtained with each model A~ model C in the histogram, (a) represents the model A (B) shows the histogram of the model B, and (c) shows the histogram of the model C.
With reference to FIG. 4, the effect of each model is compared.

In each histogram in FIG. 4, the horizontal axis indicates the error amount, and the vertical axis indicates the ratio of the error amount to the whole. That is, in the histogram of FIG. 4, it can be said that the prediction accuracy is higher as the width of the base is smaller and the height in the vicinity of the error 0 is higher.
In the histogram of model A shown in FIG. 4A, the standard deviation is 50, but in the histogram of model B shown in FIG. 4B, the standard deviation is 60.5, and the histogram of model C shown in FIG. The standard deviation is 76.1. Therefore, it can be seen that when model A is employed, the variation in prediction error is smaller than when models B and C are employed.

  Further, in the vicinity of the error 0, in the model A of FIG. 4A, the ratio shown on the vertical axis takes a value of 5% to 11%, but the ratio of the vertical axis in the model B of FIG. Is a value of 3% to 9%, and the ratio of the vertical axis in the model C of FIG. 4C is a value of 4% to 7%. Therefore, it can be seen that when model A is employed, rolling with a small prediction error can be performed with higher probability than when models B and C are employed.

  Both the model B shown in the equation (9) and the model C shown in the equation (10) use a leveling amount Δs that is a roll gap difference between the work side and the drive side. As compared with the model B and the model C using the leveling amount Δs as in the plate thickness control method described in Patent Document 1, the prediction accuracy of the model A is higher. This indicates that the prediction accuracy in the model A employed in the present embodiment is the highest in the histogram shown in FIG.

However, even when Model B and Model C are adopted instead of Model A, the thickness of the plate end of the rolled material 5 can be controlled by controlling the plate thickness at the center of the plate width. The model for this is not limited to the model A, but may be a model B and a model C.
The procedure for deriving models A to C will be described below with reference to FIG.
In FIG. 5, work rolls 2 and 2, a rolled material 5 rolled by the work rolls 2 and 2, and a support system that supports both ends of the work rolls 2 and 2 (support constituted by a hydraulic cylinder 6 and a rolling mill framework). System). The cross-sectional shape of the rolled material 5 in the sheet width direction is a wedge-shaped wedge shape, and the upper work roll 2 is inclined obliquely with respect to the lower work roll 2 in the horizontal state.

A rolling load P ₁ is applied to the left end of the upper work roll 2 in the drawing, the mill constant is M ₁ , and the roll gap is S ₁ . Further, a rolling load P ₂ is applied to an end portion on the right side of the upper work roll 2 in the drawing, the mill constant is M ₂ , and the roll gap is S ₂ . The rolled material 5 is offset rightward from the roll center of the lower work roll 2 by an off-center amount Δ toward the paper surface. The load distribution q (x) in the sheet width direction for the rolled material 5 is approximated by a linear function (q (x) = a · x + b; a and b are coefficients). Each model is derived assuming that the balance is maintained in this state.
(Model A)
First, the procedure for deriving the model A according to this embodiment will be described.

  In the state of FIG. 5, when a force balance equation is considered, equation (11) is obtained.

  Next, equation (12) can be considered as a moment balance equation.

  Here, Formula (13) is considered about the variation | change_quantity of load distribution q (x).

  From this equation (13), the slope a of the load distribution q (x) shown in equation (14) is obtained.

  If the exit side plate thickness difference at the sheet width end of the rolled material 5 is Δh, the exit side plate thickness difference Δh can be expressed as in equation (15), taking into account ΔP obtained in equation (12). .

The exit side plate thickness difference Δh obtained by Expression (15) is model A (the present invention model).
That is, since it is the exit side plate wedge Δh _W in the embodiment of the present invention and the entrance side plate thickness difference ΔH is the entrance side plate wedge ΔH _W, it is possible to obtain the model A shown in the equations (15) to (8). .
(Model B)
Next, a procedure for deriving the model B disclosed as a comparative example will be described.

Similar to the above-described model A, in the state of FIG. 5, the equations (11) and (12) can be considered as the force balance equation and the moment balance equation.
Here, the plate thickness at the position x in the plate width direction of the rolled material 5 can be expressed by Expression (16).

  From the equations (11) and (12) of the force balance equation and the moment balance equation, and the equation (16), the leveling amount Δδs corrected by the mill rigidity can be expressed as the equation (17). it can.

  Here, the rolling load difference ΔP can be expressed as in Equation (18),

Similarly to the model A, the load distribution q (x) can be expressed by Expression (13), and the slope a of the load distribution q (x) can be expressed by Expression (14).
Moreover, since the sum load P which is a total rolling load can be expressed as shown in Expression (19),

The slope a of the load distribution q (x) is expressed as shown in Expression (20) based on Expression (19), Expression (14), and Expression (17).

  By modifying such equation (20), the slope a of the load distribution q (x) can be obtained as shown in equation (21).

  Here, assuming that the exit side plate thickness difference at the sheet width end of the rolled material 5 is Δh, the exit side plate thickness difference Δh is expressed as in Formula (22) through the assumption in Formula (15) as in Model A. be able to.

Here, assuming that there is no difference between the left and right mill constants (M ₁ = M ₂ ), Expression (23) is established based on Expression (17).

  As a result, the equation (22) is calculated as shown in the following equation (24) to obtain the outlet side plate thickness difference Δh.

The exit side plate thickness difference Δh obtained by Expression (24) is model B (comparison model).
Since this is the exit side plate wedge Δh _W in the embodiment of the present invention and the entrance side plate thickness difference ΔH is the entrance side plate wedge ΔH _W , the model B shown in the equations (24) to (9) is obtained. be able to.
(Model C)
Next, the procedure for deriving the model C will be described.

  In deriving the model C, first, the model A shown in the equation (8) is deformed to obtain the equation (25).

  By substituting this equation (25) into the model B shown in equation (9), an exit side plate thickness difference Δh is obtained as shown in equation (26).

The delivery side plate thickness difference Δh obtained by Expression (26) is model C (comparison model).
Since this is the exit side plate wedge Δh _W in the embodiment of the present invention, and the entrance side plate thickness difference ΔH is the entrance side plate wedge ΔH _W , the model C shown in the equations (26) to (10) is obtained. be able to.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. In particular, in the embodiment disclosed this time, matters that are not explicitly disclosed, for example, operating conditions and operating conditions, various parameters, dimensions, weights, volumes, and the like of a component deviate from a range that a person skilled in the art normally performs. Instead, values that can be easily assumed by those skilled in the art are employed.

DESCRIPTION OF SYMBOLS 1 Rolling apparatus 2 Work roll 3 Backup roll 4 Rolling mill 5 Rolled material 6 Hydraulic cylinder 7 Entry side thickness gauge 8 Delivery side thickness gauge 9 Control part 10 Load cell 11 Chock part

Claims (2)

In the sheet thickness control method for the rolled material being rolled by a rolling mill equipped with a work roll,
A rolling load difference (ΔP) that is a difference in rolling load at both ends in the width direction of the work roll, and a wedge amount that is a difference in sheet thickness at both ends in the width direction of the rolled material, the wedge amount at the work roll entry side And calculating the exit side wedge amount (Δh _W ), which is the wedge amount on the exit side of the work roll , using the entrance side wedge amount (ΔH _W ) ,
Using the calculated exit side wedge amount (Δh _W ), the plate thickness of the plate end that is the plate thickness of the width direction end of the rolled material is obtained,
Based on the obtained plate end thickness (h _G ) and gauge meter formula, the roll gap (s) of the work roll is obtained,
A method for controlling the thickness of a rolling mill, wherein the obtained roll gap is applied to a rolling mill to control the thickness of the rolled material. The center plate thickness of the rolled material is calculated from the plate thickness (h _C ) at the center in the width direction of the rolled material obtained by a gauge meter method and the plate crown (Δh _Cr ) of the rolled material,
The calculated median thickness (h C ₊ Δh _Cr), the amount of exit-side wedge (Delta] h _W) by adding the, according to claim 1, wherein the determination of the thickness of the plate end (h _G) Thickness control method for rolling mills.