JPS6257704A - Method for controlling shape in sheet rolling - Google Patents

Abstract

PURPOSE:To considerablely expand a range for changing a sheet thickness and width by preliminarily setting a mechanical sheet crown model equation, calculating the manipulated variable of a control device by set equation and controlling the shape of a rolling sheet at a prescribed timing. CONSTITUTION:The mechanical sheet crown model equation which exhibits the relation between a sheet thickness distribution and rolling conditions in the case of the load distribution made uniform in the transverse direction is preliminarily set in the case of using a rolling mill having a control device which can control the transverse sheet thickness distribution of the rolling sheet. The manipulated variable at the operation end of the control device for the rolling mill near a joint part is calculated by using such equation. More specifically the relation of the target sheet thickness and crown is made equal to the relation of the sheet thickness and crown of the model equation; therefore, the crown quantity is determined by a reverse calculation. The timing for the change over is changed over simultaneously with the transfer of the joint part in the case of the control end having excellent responsiveness. The range for changing the sheet width and thickness is thus considerably expanded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to continuous rolling of materials having different thicknesses or widths, or materials having different thicknesses and widths, connected by welding or the like. This invention relates to a shape control method when Regarding plate thickness, there are two possible cases: the thickness of the rolled original plate is different, and the finished plate thickness is changed by changing the running plate thickness even though the thickness of the rolled original plate is the same. It can also be applied to cases where

[Conventional technology and its problems]

When continuously rolling materials having different thicknesses and widths, there is a problem in that the shape of the rolled material deteriorates due to sudden changes in rolling conditions. Therefore, in conventional rolling methods, the thickness of the plate must be adjusted to avoid such deterioration of the plate shape.

In rolling operations, the amount of change in sheet width was limited to a very narrow range, and work rolls were often rearranged. Regarding this point, the main applicant discloses the method of rolling a plate material in Japanese Patent Publication No. 60-7561 [Method of rolling plate material j], in which the connection part of the material and its vicinity is adjusted while adjusting the contact position of the work roll support member with the work roll and the roll bending force. An invention relating to a method for rolling plate materials characterized by rolling has been proposed.

According to this publication, the basic concept of a rolling method that enables a greater change in strip width than in the prior art was disclosed. The present invention is based on such a basic concept, and goes one step further to improve the shape of the sheet when changing the sheet thickness or width using a device that can generally control the sheet thickness distribution in the width direction, that is, a rolling mill having a shape control end. The purpose of the present invention is to provide guidelines for a rational determination method for the amount of control end operation, and to enable rolling of a good plate shape even when the plate thickness and width are significantly changed.

[Means for solving problems]

In order to solve the above-mentioned problems, according to the present invention, a rolling mill equipped with a thickness distribution control device having an operating end that can control the thickness distribution in the width direction of the rolled plate is used. Method of continuous rolling by connecting materials with different widths or both widths K A mechanical plate crown model formula is set in advance, and the operation amount of the operating end of the plate thickness distribution control device at the material joint and its vicinity is calculated using this mechanical plate crown model formula, and the calculated value is The feature is that the shape of the rolled plate is controlled at a predetermined timing based on the method.

Furthermore, according to another aspect of the present invention, materials having different thicknesses are connected using a rolling mill equipped with a thickness distribution control device having an operating end that can control the thickness distribution in the width direction of the rolled plate. In the continuous rolling method, the target mechanical plate crown value at the leading end of the succeeding material is calculated based on the original plate profile of the preceding material, the original plate profile of the succeeding material, and the respective rolling schedules, and this target value is applied to the rolling plate and the rolling process. Substituting it into the mechanical plate crown model equation that shows the relationship between the thickness distribution in the bias direction and the rolling conditions when the widthwise load distribution between the rolls and the rolls is uniform, the above widthwise plate thickness at the material joint and its vicinity can be calculated. The present invention is characterized in that the operation amount of the distribution control device is calculated, and the shape of the rolled plate is controlled at a predetermined timing based on the calculated value of the pattern.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail.

In addition, the control device for widthwise plate thickness distribution referred to in the present invention is a device that can control the widthwise plate thickness distribution even under the condition that the rolling load is constant, and includes a roll bending device, a variable crown roll, and a work roll shift.

Roll cross, intermediate roll shift of 6-high rolling mill.

Sleeve shift function of rolling mills with sleeves arranged on reinforcing rolls, horizontal bending of work rolls or intermediate rolls of five-high rolling mills, eccentric adjustment function of split reinforcing rolls of multi-high cluster rolling mills, etc. This means the so-called crown shape control end.

The plate thickness distribution achieved when the load distribution in the width direction between the rolling plate and the work rolls is uniform is determined by the type and dimensions of the rolling mill, the setting conditions of the crown/shape control end, the rolling load, and the thickness of the rolled material. If rolling conditions such as sheet width are given, it is determined only by the deformation characteristics of the rolling mill, regardless of other deformation characteristics of the rolled material. The plate crown determined from such a plate thickness distribution is hereinafter referred to as a mechanical plate crown.

The applicant filed a patent on October 20, 1981 entitled "Rolling Control Method." In this invention, it is disclosed that mechanical plate crowns can be modeled with high precision without numerical calculations, and as an example, a model formula for calculating the mechanical plate crown of a four-high rolling mill with roll bending equipment fle'z is disclosed. The following equation was derived.

C=2(C8,-α(CB,-C,,)1-2(1+α
) C, -2αCia"2Cr Each term in equation (1) is doubled to take into account the vertical roll, and is based on the precondition of vertical symmetry. In the case of vertical asymmetry, All you have to do is calculate the amount for each roll and add them together.

C8W is the work roll deflection calculated assuming that the load distribution between the work roll and the reinforcing plate is uniform in the width direction, converted to the plate crown definition point (reference point), 066t
; are obtained by converting the reinforcing roll deflection determined based on the same assumption into the plate crown definition point, and are given by the following formulas.

However, work is the second moment of inertia of the roll, S is the cross-sectional area of the roll body, a is WS <Work 4JJA), DS (!X
AX fibrillation distance between ticks, E is Young's modulus of roll, G
is the transverse elastic modulus of the roll, and the subscripts W and S represent the work roll and the reinforcing roll, respectively. Also! is the roll body length, and strictly speaking it means the contact width between the work roll and the reinforcing roll. b is the plate width, β is the distance from the plate edge to the plate crown definition point, P is the rolling load, F is the roll bending force of 1 piece ζ, and the increase pending force is positive/daily penting. force is defined as negative. Cl@CRe1 in formula (1) is the roll crown of the work roll and the reinforcing roll, respectively, converted into a plate crown definition point, and the convex crown side is set as positive in radius expression. Further, C2 is the effect of the flattening deformation of the work roll due to contact with the rolled material on the mechanical plate crown), and can be determined by the following equation.

However, L is the projected contact arc length, ψ is the bore-den ratio, π multiplied by pi, d is DW d=-(51), DW is the working rail diameter, and e is the base of the natural logarithm (e=2.718282 ...).α is (1)
This is the key parameter of the equation and is called the nonlinear load distribution correction coefficient.0 This is the work roll (work roll) WR,! = m strong roll (backup roll) SU
Corrects the non-linearity of the load distribution caused by the difference between the work roll deflection and the reinforcement deflection, which is calculated assuming that the load distribution between the R and R is uniform, and the non-linearity of the load distribution caused by the mismatch between the work roll crown and the reinforcement roll crown. Therefore, by assuming that the change in work roll deflection caused by the influence of this nonlinearity is a quadratic equation, the following equation is obtained.

α” Aw/ (1+ A, + All)
1G) However, the symbol is the roll diameter, k is the work roll-reinforcement is the spring constant per unit body length of roll flattening deformation between one roll, and π is pi.

4-high rolling mill with variable crown roll arranged on reinforcing roll,
For work roll shift type 4fBt rolling mills, roll cross type 4-high rolling mills, or 4-high rolling mills with sleeves on reinforcing rolls, etc., the following formulas are added to the mechanical plate crown model formula of the 4-high EE rolling mill described above. It is sufficient to consider the effect of the crown shape control function.

In the case of a 6-high rolling mill with an intermediate roll shift system, which is currently the most typical strong crown/shape control mill, the concept of nonlinear load distribution correction coefficient is somewhat complicated due to the presence of intermediate sails, but the following model can be used. Can be formulated.

C= 2(Cat-CB+(::r-"rw('aw"
cl+cRI)-(IB(C*t"C1a-Can)]
Note that π work v is an apparent nonlinear load distribution correction coefficient that represents the influence of the gap between the work roll and the intermediate roll on the deflection of the work roll WR, and 'iiiI 8 is the gap between the intermediate roll and the reinforcement roll that is WR These are apparent nonlinear load distribution correction coefficients representing the influence of deflection K, and are given by the following equations.

α!・=1−α11. α16 );-1 effect (11) y α, = − (12) 1 +A, +AI.

AIW (13) 11w-10AW+AfW The subscript is the intermediate roll (IMR), and the IW is WR~IM
The contact portion of R, IB means the amount related to the contact portion of BUR to IMR.

cRecRl fclI8 is a result of converting the roll crowns of the work roll, intermediate roll, and reinforcing roll into plate crown definition points, with the convex crown side being positive in radius display.

C in formula (9) is calculated assuming that the load distribution between the work roll and the intermediate roll is a linear distribution in the sheet width direction, and is calculated by converting the large work roll deflection to the sheet crown definition point % C6
B is the reinforcing roll deflection obtained on the assumption that the load distribution between the intermediate roll and the reinforcing roll is a linear distribution in the width direction of the board, converted to the board crown definition point, and is given by the following equations.

Tsu-β)...F' (19) Just 21), and XTW is the coordinate that indicates the position of the midpoint of the contact range between the work roll and the intermediate roll in the coordinate system taken in the sheet width direction with the mill center as the origin. .

The body lengths of the work roll, intermediate roll, and reinforcing roll are all l.
Alternatively, when the roll shift is performed only on the intermediate roll and the shift amount is S, equations (19) to (211) can also be expressed as in the following equations.

C2 in formula (9) is exactly the same as that in formula (1),
The flattening deformation of the work roll due to contact with the rolling material has an effect on the mechanical plate crown. Formula (4) % formula I was able to get it.

Next, an example of the accuracy verification results of the mechanical plate crown model explained above will be shown. The method of accuracy verification is to divide the roll body into 40 parts in the width direction and compare the results calculated by a program that numerically calculates the roll deformation with the results calculated by the mechanical plate crown model formula.

Tables 1 and 2 show the four-high rolling mills used in the calculations.

The mill dimension of a 6-high rolling mill is shown. Board width is 840
Two types: m+a and 1344-, plate thickness is entry side plate thickness 5.0
The rolling load was as shown in Table 3.

Table 2. 6-tier mill Dimenzi carbon (Unit: mm) Table 3. Rolling load conditions For a 4-tier mill, the roll bending force is '6-ioo.

0, 10 (3 types of ltcn/cbook, roll bending force -50, 0, 50 for 6-tier mill)
3at type of ton/chock, intermediate roll shift amount is 0 and 336m when plate width is 84〇-, plate width is 1344m
0 and 168III11, respectively, were classified as Class 2ai.

Figures 1 and 2 show the calculation results for a 4-high mill and a 6-high mill, respectively. Under all conditions, the difference between the calculation results for the split model and the mechanical plate crown Sodel formula is on the order of several μm, and this It can be seen that the mechanical plate crown model formula explained above has extremely high accuracy.

Now, in order to perform shape flat throat rolling, the entrance plate crown ratio is calculated by dividing the entrance plate crown q by the input plate thickness H, and the exit plate crown Ch is divided by the exit plate thickness [7]. It is widely accepted that this is a good thing. That is, it is sufficient if the following holds true. When formula (25) holds true, the distribution of rolling reduction in the width direction of the plate is uniform, so if the deformation resistance of the rolled material is uniform in the width direction, the distribution of rolling load in the width direction is also uniform. It is thought that it will become. Therefore, the outlet plate crown Ch at this time is equal to that of the mechanical plate crown, and the conditions for performing shape flat rolling can be expressed as follows. Since the right-hand side of equation (26) is data that can be estimated in advance, the setting of the widthwise plate thickness distribution control device for performing profile flavut rolling is performed from equation (26) using the model equation of C that has been explained so far. You can find the value. Note that if the deformation resistance distribution in the width direction cannot be considered uniform, a correction term thereof may be introduced into equation (26). It was confirmed by numerical calculation whether formula (26) guarantees shape flat rolling, and the results are shown in FIG.

The vertical axis of Figure 3 is the plate shape calculated using a numerical calculation program that can calculate the shape of a cold-rolled plate, expressed by the tension difference A4 at a point separated by the center of the plate and the width of the plate, and the horizontal axis. The difference between the entry side plate crown ratio and the mechanical plate crown ratio (mechanical plate crown divided by the exit side plate thickness) is taken for the axis, and the position of horizontal axis 0 is the point where equation (26) holds. be. In this respect, A4 has a slightly negative value, but A4 is 0 regardless of the plate thickness, and a very good shape has been achieved.

Materials with different thickness or width, or thickness.

When connecting and continuously rolling materials with different widths, the rolling conditions change significantly at the joint, so (2
6) The mechanical plate crown on the left side of the equation is also large! , and the right-hand side may also change depending on the case.
) no longer holds true and the plate shape becomes disordered.

With conventional technology, although it is possible to predict the change on the right side of equation (26), it is not possible to accurately predict the change on the left side using a process computer and furthermore calculate the amount of operation at the control end to compensate for this. Although this is possible, the present invention has made this possible by using the mechanical plate crown model formula presented so far. The present invention will be explained in more detail below by taking cold tandem rolling of a steel plate as an example.

In tandem cold rolling of steel plates, even if rolling with a constant crown ratio is no longer possible in the intermediate stand, the unevenness of the rolling reduction in the width direction will not appear in the width expansion υ, but will almost always result in a difference in elongation rate in the longitudinal direction. In other words, since this appears as a disturbance in the plate shape, the crown ratio of the plate when the shape is finally made flat will be equal to the crown ratio of the original plate. Therefore, no matter which stand of the tandem rolling mill is used, rolling should be carried out so that the mechanical plate crown ratio (I:1/h1) of the original plate crown ratio CM/H is matched with ζ.However, 1 is the stand number.Therefore, The shape flat condition in the case of tandem rolling is expressed by the following equation.

Now, it is only necessary that the following equations hold true when the quantities of the preceding material are represented by subscript 1 and the following material is represented by subscript 2, and the information on the crown of the original sheet is accurate, and the roll profile due to thermal expansion and wear during rolling is correct. If the change in can also be estimated accurately, (2
8) A widthwise plate thickness distribution control device such as a roll bending machine may be operated to change the equation (7) C to the equation (29) No. Ci2 at the joint portion. The amount of operation at this time is
The information on the 0 general KyX plate crown, which can be easily calculated backwards from the mechanical plate crown model formula, has become quite reliable due to the spread of online profile meters in hot rolling mills in recent years.
Since H is always large compared to , the influence of the error in No. (27) 2 is relatively small, and becomes even smaller in the later stages of the tandem rolling mill where the plate shape is a problem. On the other hand, changes in the roll profile during rolling depend on pure calculation results since there is no direct detection end, and the effects directly appear on each stand, so we have not explained them so far. This is the biggest problem when applying the shape control method. Next, a control method that takes into consideration such roll profile estimation errors will be described.

The mechanical plate crown model formula is rolling technique iPi.

When sorted by the factor of roll bending force F11 plate crown CR1 converted to plate crown definition point, C1=c,'-p,+C-・Fi+CR'・Cat
(30) can be expressed in the form. However, C,1, C,i.

C and i are model coefficients determined from mill dimensions and the like.

It is now assumed that in the latter half of rolling the preceding material, steady rolling has been achieved with a good shape as a result of automatic shape control or manual intervention by the operator. Actual rolling load measurement value P, □ collected during this collection. , when the mechanical plate crown obtained by substituting the measured roll bending force value F11° and the estimated roll crown value CR11 into equation (30) is C0, C
1° generally does not satisfy equation (28), ctt+ε,=h,, 珈=(31)H.

An error term ε1 appears as follows. Most of this C1 is thought to be due to the estimation error of the role profile, so
From C1 6□=(1・ΔCox (32)
Therefore, the roll crown correction term △Cyu1. is obtained. ★ CRj to the stock + the plate crown definition point of the preceding material.

Since this is a corresponding roll crown correction term, generally when considering the control of trailing materials having different sheet widths, ΔCR11 must be expanded and learned in the roll body length direction. This expansion method is considered to be most basic in that the distribution of the roll profile correction amount in the torso length direction is a parabolic (quadratic) distribution.

The exponent should be a variable constant so that quartic expressions can also be selected! Delicious. If this index is n, the distribution of the cello profile correction amount ΔCW1 in the trunk length direction is ΔC1l = f1 ・x
n(33) where X is a coordinate in the body length direction with the origin at the center of the roll body length. Therefore, when the plate width of the preceding material is b and the plate crown reference point is β from the plate edge, the roll profile correction term fit obtained from the rolling results of the preceding material is
Accordingly, the roll crown C312 when calculating the mechanical plate crown of the trailing material is CR12=CIH2" fl ・(bz - β)"
0 but CRI□ which can be found by (35)
is the roll crown calculated by adding the temporal change of the four-wheel profile to the initial roll curve using a mathematical model and converting it to the plate crown definition point of the trailing material, and fl is f in equation (34).
it 1r, may be used as is, but after role reshuffling,
The learning gain G (general V
Multiplying CO<'G<l'l and updating the previous value 11n using the following formula, use fl, and set G according to the situation.
It would be practical to chain the values of and n.

After clIts is determined by equation (35), the operation amount and operation timing of the widthwise plate thickness distribution control device, such as a roll bending machine, may be determined so that equation (29) holds true with the joint as a boundary. According to this method, when the amount of change in the roll profile is relatively small, C,...
It is also possible to use the initial roll carp itself.

Next, we will explain the shape control method when only the plate thickness changes without changing the plate width. ○If the plate width does not change,
In the roll crown, the leading material and the trailing material can be considered to be equal, and there is no need to learn by expanding the roll crown in the roll body length direction as explained above. In other words, (3
Since the nine error terms e shown in equation 1) can be considered to be equal for the preceding material and the following material, it is sufficient to make the amount of change on the left side of the shape flat condition condition (27) equal to the amount of change on the right side.

Therefore, the target mechanical plate crown is 1! can be found. In other words, the amount of change in the mechanical plate crown can be determined from the change in the original plate crown ratio and the change in the reduction schedule, and the target mechanical plate crown "12" calculated based on this change amount is realized using the joint as the boundary. What is necessary is to find the operation amount and operation timing of the width direction plate thickness distribution control device such as roll bending force.

Up to now, the method for calculating the operation amount of the six-direction plate thickness distribution control device has been explained, and next, the method for determining the operation timing will be explained. If the widthwise plate thickness distribution control device has sufficient responsiveness and can immediately reach a setting value that allows the target mechanical plate crown of the succeeding material to be easily achieved from the setting value of the preceding material at the material joint, the relevant It is sufficient to switch to the set value for the trailing material at the same time that the stand starts rolling the material joint, and there is no need to pay special attention to the operation timing as long as the joint is accurately tracked. Examples of such control ends with excellent responsiveness include roll bending devices and variable crown rolls. However, the response speed of the control end of the roll cross, work roll cross, intermediate roll shift of a six-high rolling mill, and sleeve shift of a rolling mill with a sleeve on the reinforcing roll is generally slow, and the It is often impossible to terminate the operation of these control ends at the joint. The concept of operation timing in such a case will be explained using a six-high rolling mill having an intermediate roll shift function as an example.

In general, even rolling mills with control ends with slow response speeds such as those mentioned above, without exception, have control ends with excellent responsiveness called roll bending devices, and while the control end with slow response speeds does not reach the target position The aim is to achieve the target mechanical plate crown by compensating with a four-wheel bending device. Figure 5 shows a method of controlling a specific stand when moving from a leading material with a large width to a succeeding material with a small width in a six-high rolling mill with an intermediate roll shift function. . Figure 5a shows the four-wheel pending force F and the intermediate roll position δ (plate @ intermediate roll 2 located at a short distance from the end) to maintain the current mechanical plate crown obtained from the rolling results of the rear end of the preceding material. If the intermediate roll body end is inside the rolled material at the distance to the body end of the intermediate roll body, it takes a negative sign. Fig. 17 shows the relationship between F and δ for the pipe, and Fig. 14 schematically shows the method of controlling the material joints (1 is the backup roll, 2 is the intermediate roll , 3 indicates a work roll, and 4 indicates a rolled material.The mechanical plate crown constant curve of the preceding material is given by equation (31) and the mechanical plate crown model equation, and the mechanical plate crown constant curve of the succeeding material is given by (29). In the formula and roll crown section (35)
It is given by the nine mechanical plate crown model equation using equation C612. The positional relationship of these curves is affected by the amount of change in the original plate crown and reduction schedule, as well as the current roll profile, so various cases can be considered, but we do not want to cover all of them here, and we will focus on typical cases. The basic concept and implementation will be explained using an example.

Both the leading material and the trailing material can be rolled in a good shape at any point on the mechanical plate crown constant curve shown in Figure 5a, but in actual operation, the intermediate roll position is There are demands to make the roll bending force as large as possible in terms of the contact stress acting on the roll, and to leave as much margin as possible in the roll bending force to prepare for fluctuations in rolling conditions. Therefore, point A is selected as the optimal control point for the preceding material, and rolling is currently being carried out at this point, and point B for the succeeding material is selected as the optimal control point.
Assume that the point is selected as the optimal control point. If the joint is rolled in the state at point A, the width of the plate will increase at the intermediate roll position Kyop -! −(b, −b, )
becomes larger, and the control point moves to 0 point.

Matadasu 1. b is the plate width of the leading material and the trailing material, respectively. At point 0, the target mechanical plate crown of the trailing material is not achieved and a defective shape occurs, so at the same time as rolling of the joint begins, the roll bending force is increased to the increase side and the control point is set to B" In this method, the roll bending force at point B'' will be extremely large, and in some cases, it may not be possible to move to point B due to equipment capacity constraints. There is also the problem that it takes time to reach point B from point B to point K, and that it takes time for the succeeding material to enter the steady rolling state. The following button can be used to alleviate this difficulty. First, the intermediate roll shift amount from point A to point B is calculated, and the time Δt required to shift by that amount is determined. The intermediate roll shift is started Δt/2 before the joint reaches the rolling mill, and at the same time the roll bending force is controlled to maintain the mechanical plate crown. When this point is reached, the rolling of the joint begins.
By controlling the roll bender, the mechanical plate of the trailing material is brought to the point B along a constant curve of the crown.
Just bring it to the point. FIG. 5b is a diagram showing this control method along the rolled material, and shows the preceding material 5 and the trailing material 6.
The trajectory of the intermediate roll body end, the intermediate roll position, and the control pattern of the roll bending force in the vicinity of the joint are shown.

Contrary to FIG. 5, FIG. 6 shows a control method when the width of the succeeding material is larger than that of the preceding material.

If it enters the joint while remaining at point A in Figure 6a, then B
Since the control point moves to the ``point, δ〈0'', special KA!
At the final stand, problems may arise with the surface quality of the finished product. Therefore, even in this case, it is desirable to start the intermediate roll shift before starting rolling of the joint part and control it along the path A-A-B'-B. In either case, if control is performed so that the material joint is located approximately in the center of the material to be rolled from the start of the intermediate roll shift to the end of the shift, the following material can be rolled without greatly deviating from the control conditions during steady rolling of the preceding material. The target control conditions can be reached.

When operating the intermediate roll shift and roll bending force, the mill stretch also changes, so the rolling down device must be controlled so that the thickness of the outlet side of the stand does not change.

In addition, when performing the control described above on a low-level computer with small capacity, rather than calculating directly using the mechanical plate crown model, mechanical calculations such as those shown in Figures 5a and 6a A more practical method is to calculate a constant board 2-un curve on a higher-level computer and use this curve in a lower-level computer to perform control.

In the above explanation, as an example of the mechanical plate crown model formula, formulas theoretically obtained for a 4-high rolling mill and a 6-high rolling mill were shown, but for any other type of rolling mill, No matter what method is used to obtain the formula, as long as it has sufficient accuracy for practical use, and the effects of factors such as the roll curve, the setting value of the widthwise plate thickness distribution control end, and the rolling load can be separated, the present invention is applicable. Needless to say, can be applied in exactly the same way.

〔Effect of the invention〕

As described above, by applying the present invention, the allowable range of changes in plate thickness and width in continuous rolling is dramatically expanded, and roll changes due to plate shape can be largely omitted. It is possible to obtain great effects such as cost reduction by improving the operating rate of the equipment, and improvement in quality and yield by improving the shape of the plate at the tip of the rolled material.

[Brief explanation of drawings]

Figures 1 and 2 compare the mechanical plate crown calculation results obtained by numerical calculations using the mechanical plate crown model formula and the split model. Figure 2 shows the case of a 6-high rolling mill, Figure 3 shows the relationship between the difference between the entrance plate crown ratio and the mechanical plate crown ratio and the plate shape, investigated by chimieresis, and Figure 4 shows the case of a 6-high rolling mill. Schematic diagram of Fig. 5a, Fig. 5b, Fig. 6
Figures a and 6b are diagrams showing an embodiment when rolling the vicinity of joints of materials of different thicknesses and widths using a six-high rolling mill with an intermediate cylinder shift system. Figures 6a and 6b are diagrams showing the transition from a narrow material to a wide material. 1...Reinforcement roll, 2...Intermediate roll, 3...Work roll, 4...Rolled material,
5... Leading rolled material, 6... Following rolling material, 7... Locus of intermediate roll gli11 end. S=OS-OS=OS=Smax Roll bending force F (torvC?ock) Intermediate roll shift amount S (mm) Crown ratio deviation C1, I/H-c/h (163) 3rd
Figure 4Fi2'I Figure 5b

Claims (1)

[Claims] 1. Using a rolling mill equipped with a plate thickness distribution control device having an operating end that can control the thickness distribution in the width direction of a rolled plate, the plate thickness or plate width, or the plate thickness or plate width. Mechanical plate crown model showing the relationship between the widthwise plate thickness distribution and rolling conditions when the widthwise load distribution between the rolling plate and work roll is uniform when connecting and continuously rolling materials that are different in both sides. A formula is set in advance, and the mechanical plate crown model formula is used to calculate the operation amount of the operating end of the plate thickness distribution control device at the material joint and its vicinity, and based on the calculated value, the operation amount is calculated at a predetermined timing. A shape control method in plate rolling, characterized by controlling the shape of a rolled plate. 2. The control method according to claim 1, wherein the operating end has at least a roll bending force. 3. The control method according to claim 1, wherein a rolling mill having shift rolls has at least a roll shift position as an operating end. 4. The mechanical crown amount expressed by the mechanical plate crown model formula is constituted by factors representing the roll curve, the set value of the width direction plate thickness distribution control end, and the rolling load. Control method described in section. 5. When connecting and continuously rolling materials with different thicknesses using a rolling mill equipped with a thickness distribution control device having an operating end that can control the thickness distribution in the width direction of the rolled plate, the original plate of the preceding material The target mechanical plate crown amount at the tip of the trailing material is calculated based on the profile and the original plate profile of the trailing material and the respective rolling schedules. By substituting into the mechanical plate crown model equation which shows the relationship between the width direction plate thickness distribution and rolling conditions in the case of uniformity, the operation amount of the width direction plate thickness distribution control device at the material joint and its vicinity is calculated. A shape control method in plate rolling, characterized by controlling the shape of a rolled plate at a predetermined timing based on a calculated value. 6. The control method according to claim 5, characterized in that when setting the target value, rolling performance data of the preceding material is added. 7. The control method according to claim 6, wherein when calculating the target value, a correction amount of the roll crown amount according to the amount of plate thickness change is further taken into account from the actual value of the preceding material.