JP2018051628A - Rolling control method, steel plate manufacturing method, rolling controller and steel plate manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling control method by which a plate crown can be controlled over the entire length of a rolled material, a steel plate manufacturing method, a rolling controller and a steel plate manufacturing device.SOLUTION: A rolling control method is the rolling control method for a rolling machine 1 which comprises work roll benders 13, 14 which can control a plate crown which indicates plate thickness distribution of a rolled material W in a width direction, and a plate thickness meter 18 which is located on an outlet side of the rolling machine 1, and measures the plate crown on the outlet side of the rolling machine 1 by measuring plate thicknesses of at least two points in the width direction of the rolled material W. According to this method, in the case that there is a difference between a preset target value of the plate crown and a measurement value of the plate crown which is measured by the plate thickness meter 18 during rolling by the rolling machine 1, a control volume when the work roll benders 13, 14 control the plate crown in a same rolling pass is changed by a control change volume calculated based on the difference.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling control method and a steel plate manufacturing method using the same, a rolling control device and a steel plate manufacturing device using the same.

  Control of the sheet crown in rolling is an important elemental technology that determines not only the sheet thickness control of the material to be rolled (steel plate) but also the flatness (shape) of the material to be rolled. Here, the “plate crown” is a plate thickness distribution in the width direction of the material to be rolled. Specifically, the plate thickness at the center in the width direction of the material to be rolled and the plate thickness at the end in the width direction. Showing the difference. Further, “flatness” indicates the distribution in the width direction of the difference in the plate length of the material to be rolled, and is specifically defined by the elongation difference rate [%] or the like.

  Conventionally, a technique for controlling a sheet crown of a material to be rolled has been proposed. For example, a method of compensating for deflection of a work roll by giving a convex curve to the work roll, and applying pressure to a work roll chock A method using a work roll bender that controls the deflection of the work roll, or a plate crown control actuator that controls the deflection of the work roll by narrowing the region where the reaction force from the backup roll acts (for example, a work roll shift or the like) ) Has been proposed.

  Further, the flatness of the material to be rolled is one of the elements having an important meaning in the subsequent processes, and conventionally, the plate crown is controlled for the purpose of controlling the flatness. For example, in Patent Documents 1 to 3 shown below, a method for measuring the actual flatness of a material to be rolled after rolling with a sensor and controlling the plate crown control actuator so that the flatness shape becomes a target. Has been proposed.

JP 2000-94020 A JP 2005-319492 A JP 2006-272460 A

  Recently, particularly in the field of shipbuilding materials, it is desired to use a steel plate that is as thin as possible within the tolerance range, that is, a light steel plate, in order to improve the fuel efficiency of the ship. Therefore, it is necessary to build not only the flatness of the material to be rolled but also a desired plate crown over the entire length of the material to be rolled. However, since the control methods disclosed in Patent Documents 1 to 3 are intended only to control the flatness of the material to be rolled, the plate crown cannot be controlled over the entire length of the material to be rolled.

  The present invention has been made in view of the above, and provides a rolling control method, a steel plate manufacturing method, a rolling control device, and a steel plate manufacturing device capable of controlling a sheet crown over the entire length of a material to be rolled. With the goal.

  In order to solve the above-described problems and achieve the object, a rolling control method according to the present invention includes a plate crown control mechanism capable of controlling a plate crown indicating a plate thickness distribution in the width direction of a material to be rolled, and a rolling mill. Rolling control of a rolling mill comprising: a sheet thickness meter that is installed on the exit side and measures the sheet crown on the exit side of the rolling mill by measuring at least two sheet thicknesses in the width direction of the material to be rolled In the method, when there is a difference between a preset target value of the plate crown and a measured value of the plate crown measured by the plate thickness meter during rolling by the rolling mill, The control amount when the plate crown control mechanism controls the plate crown is changed by a control change amount calculated based on the difference.

  In the rolling control method according to the present invention, in the above-described invention, a preset target value of the plate crown and a measured value of the plate crown measured by the plate thickness meter are set in the same rolling pass. If there is a difference between them, the control amount when the plate crown control mechanism controls the plate crown and the control change amount calculated based on the difference are both affected by the width of the material to be rolled. Is corrected.

  Further, in the rolling control method according to the present invention, in the above invention, the influence due to the breadth of the material to be rolled is corrected in consideration of at least the plate thickness, the sheet width, the deformation resistance and the rolling reduction of the material to be rolled. It is characterized by becoming.

In the rolling control method according to the present invention, in the above-described invention, a preset target value of the plate crown and a measured value of the plate crown measured by the plate thickness meter are set in the same rolling pass. When there is a difference between them, the control change amount ΔP _{B represented} by the following equation (2) is added to the control amount P _B represented by the following equation (1).

（但し、上記式（１）および上記式（２）において、Ｃｒ_ｉは圧延機の出側における板クラウンの目標値、Ｃｒ_ｉ−１は圧延機の入側における板クラウンの計算値または実績値、ΔＣｒは被圧延材の幅広がりによる影響を補正する板クラウン補正項、αはワークロールの幅方向に均一荷重が作用した際のワークロールのたわみが圧延後の板クラウンに及ぼす影響比率、βは圧延前の板クラウンが圧延後の板クラウンに及ぼす影響比率、Ｉｃ_Ｐは圧延荷重によってワークロールがたわむ影響係数、Ｐ_Ｒは圧延荷重、Ｉｃ_Ｂは板クラウン制御機構によってワークロールがたわむ影響係数、ＷＲ_{ｐｒｏｆｉｌｅ}は無負荷時のワークロールプロフィル、Ｉｃ_Ｗは無負荷時のワークロールプロフィルが圧延後の板クラウンに及ぼす影響係数、である。また、上記式（２）において、Ｃｒ_Ｆｂは板厚計によって測定された圧延後の板クラウンの測定値である）

(However, in the above formula (1) and the formula (2), Cr _i is the target value of strip crown on delivery side of the rolling mill, Cr _i-1 calculated values or actual value of the strip crown at the entry side of the rolling mill , ΔCr is a sheet crown correction term that corrects the influence of the spread of the material to be rolled, α is an influence ratio of the deflection of the work roll when a uniform load is applied in the width direction of the work roll on the sheet crown after rolling, β effect ratios strip crown before rolling on the strip crown after rolling, Ic _P influence coefficient bend the work roll by the rolling load, P _R is the rolling load, influence coefficient Ic _B is the work roll bends the strip crown control mechanism , WR _profile is a work roll profile under no load, and Ic _W is an influence coefficient of the work roll profile under no load on the sheet crown after rolling. In the above formula (2), Cr _Fb is a measured value of the rolled sheet crown measured by a sheet thickness meter)

  In order to solve the above-described problems and achieve the object, a method for manufacturing a steel sheet according to the present invention includes the rolling control method described above.

  In order to solve the above-described problems and achieve the object, a rolling control apparatus according to the present invention includes a plate crown control mechanism capable of controlling a plate crown indicating a plate thickness distribution in the width direction of a material to be rolled, and a rolling mill. Rolling control of a rolling mill comprising: a sheet thickness meter that is installed on the exit side and measures the sheet crown on the exit side of the rolling mill by measuring at least two sheet thicknesses in the width direction of the material to be rolled In the apparatus, when there is a difference between the preset target value of the plate crown and the measured value of the plate crown measured by the plate thickness meter during rolling by the rolling mill, The control amount when the plate crown control mechanism controls the plate crown is changed by a control change amount calculated based on the difference.

  Further, in the above invention, the rolling control device according to the present invention includes a preset target value of the plate crown and a measured value of the plate crown measured by the thickness gauge in the same rolling pass. If there is a difference between them, the control amount when the plate crown control mechanism controls the plate crown and the control change amount calculated based on the difference are both affected by the width of the material to be rolled. Is corrected.

  Further, in the rolling control device according to the present invention, in the above invention, the influence due to the breadth of the material to be rolled is corrected in consideration of at least a plate thickness, a plate width, a deformation resistance, and a reduction ratio of the material to be rolled. It is characterized by becoming.

Further, in the above invention, the rolling control device according to the present invention includes a preset target value of the plate crown and a measured value of the plate crown measured by the thickness gauge in the same rolling pass. When there is a difference between them, the control change amount ΔP _{B represented} by the following equation (2) is added to the control amount P _B represented by the following equation (1).

（但し、上記式（１）および上記式（２）において、Ｃｒ_ｉは圧延機の出側における板クラウンの目標値、Ｃｒ_ｉ−１は圧延機の入側における板クラウンの計算値または実績値、ΔＣｒは被圧延材の幅広がりによる影響を補正する板クラウン補正項、αはワークロールの幅方向に均一荷重が作用した際のワークロールのたわみが圧延後の板クラウンに及ぼす影響比率、βは圧延前の板クラウンが圧延後の板クラウンに及ぼす影響比率、Ｉｃ_Ｐは圧延荷重によってワークロールがたわむ影響係数、Ｐ_Ｒは圧延荷重、Ｉｃ_Ｂは板クラウン制御機構によってワークロールがたわむ影響係数、ＷＲ_{ｐｒｏｆｉｌｅ}は無負荷時のワークロールプロフィル、Ｉｃ_Ｗは無負荷時のワークロールプロフィルが圧延後の板クラウンに及ぼす影響係数、である。また、上記式（２）において、Ｃｒ_Ｆｂは板厚計によって測定された圧延後の板クラウンの測定値である）

(However, in the above formula (1) and the formula (2), Cr _i is the target value of strip crown on delivery side of the rolling mill, Cr _i-1 calculated values or actual value of the strip crown at the entry side of the rolling mill , ΔCr is a sheet crown correction term that corrects the influence of the spread of the material to be rolled, α is an influence ratio of the deflection of the work roll when a uniform load is applied in the width direction of the work roll on the sheet crown after rolling, β effect ratios strip crown before rolling on the strip crown after rolling, Ic _P influence coefficient bend the work roll by the rolling load, P _R is the rolling load, influence coefficient Ic _B is the work roll bends the strip crown control mechanism , WR _profile is a work roll profile under no load, and Ic _W is an influence coefficient of the work roll profile under no load on the sheet crown after rolling. In the above formula (2), Cr _Fb is a measured value of the rolled sheet crown measured by a sheet thickness meter)

  In order to solve the above-described problems and achieve the object, a steel sheet manufacturing apparatus according to the present invention includes the rolling control apparatus.

  According to the present invention, in the same rolling pass of the material to be rolled, when a difference occurs between the target value and the measured value of the plate crown, each time, in order to correct the control amount of the plate crown control mechanism, It can control so that it may become a desired board crown over the full length of a to-be-rolled material.

FIG. 1 is a schematic view schematically showing a configuration of a steel sheet manufacturing apparatus including a rolling control apparatus according to an embodiment of the present invention. FIG. 2 is a flowchart for explaining a rolling control method using the rolling control device according to the embodiment of the present invention. FIG. 3 is a graph showing the relationship between the plate crown and the plate length in an example for confirming the effect of the rolling control method using the rolling control device according to the embodiment of the present invention.

  A rolling control method, a steel plate manufacturing method, a rolling control device, and a steel plate manufacturing device according to the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Steel plate manufacturing equipment]
A steel plate manufacturing apparatus according to an embodiment of the present invention manufactures a steel plate whose plate crown is controlled, and includes a rolling mill 1 and a control device 2 as shown in FIG. The rolling mill 1 includes work rolls 11 and 12, work roll benders 13 and 14, backup rolls 15 and 16, a load cell 17, and a thickness gauge 18.

  The work rolls 11 and 12 are arranged so as to face the thickness direction of the material to be rolled W across a conveyance path for conveying the material to be rolled W in the conveyance direction (longitudinal direction). The work rolls 11 and 12 continuously roll the material to be rolled W by rotating (spinning) the material to be rolled W that is sequentially transported along the transport path while being sandwiched in the thickness direction.

  Work roll benders (plate crown control mechanisms) 13 and 14 control the plate crown of the material W to be rolled. Specifically, the work roll benders 13 and 14 perform a roll bending operation of bending the work rolls 11 and 12 in the thickness direction of the material to be rolled W for the purpose of controlling the sheet crown of the material W to be rolled. The work roll vendors 13 and 14 are arranged in the work rolls 11 and 12, respectively.

  Specifically, the work roll bender 13 imparts a bending force in the thickness direction of the material to be rolled W to the work roll 11 while rotatably supporting a roll shaft (not shown) of the work roll 11. At that time, the direction of the bending force applied to the work roll 11 (upward) is opposite to the direction of the load applied from the backup roll 15 to the work roll 11 (downward). Further, the magnitude of the bending force applied to the work roll 11 is determined based on the control amount of the work roll bender pressure calculated by the control amount calculation unit 21 described later. The operation of the work roll bender 13 is controlled by a control unit 23 described later based on a control amount of the work roll bender pressure calculated by the control amount calculation unit 21 described later.

  In addition, the work roll bender 14 specifically applies a bending force in the thickness direction of the material to be rolled W to the work roll 12 while rotatably supporting a roll shaft (not shown) of the work roll 12. . At that time, the direction of the bending force applied to the work roll 12 (downward) is opposite to the direction of the load applied from the backup roll 16 to the work roll 12 (upward). The magnitude of the bending force applied to the work roll 12 is determined based on the control amount of the work roll bender pressure calculated by the control amount calculation unit 21 described later. The operation of the work roll bender 14 is controlled by a control unit 23 described later based on a control amount of the work roll bender pressure calculated by the control amount calculation unit 21 described later.

  The backup rolls 15 and 16 are disposed so as to face each other with the pair of work rolls 11 and 12 interposed therebetween. The upper backup roll 15 contacts the outer peripheral surface of the upper work roll 11 from above and presses the work roll 11 downward. Thereby, the backup roll 15 gives the work roll 11 a load required for rolling the material to be rolled W. Further, the lower backup roll 16 contacts the outer peripheral surface of the lower work roll 12 from below and presses the work roll 12 upward. Thereby, the backup roll 16 gives the work roll 12 a load required for rolling the material to be rolled W.

  The load cell 17 is provided on the backup roll 15 and detects a rolling load applied to the material W to be rolled. Then, the load cell 17 outputs the detected rolling load to the control device 2 (specifically, the control amount calculation unit 21 and the control change amount calculation unit 22).

  The thickness gauge 18 measures the crown of the material W to be rolled. The thickness gauge 18 is installed on the exit side of the rolling mill 1, and measures the sheet thickness of at least two points in the width direction of the material to be rolled W to measure the sheet crown (of the material W to be rolled) on the exit side of the rolling mill 1. The difference between the plate thickness at the center in the width direction and the plate thickness at the end in the width direction is measured. The thickness gauge 18 then outputs the measured value of the plate crown to the control device 2 (specifically, the control amount calculation unit 21 and the control change amount calculation unit 22).

The thickness gauge 18 may be provided on the entry side of the rolling mill 1 in addition to the exit side of the rolling mill 1. By arranging the rolling mill 1 of the ingress even thickness gauge 18, the below-described formula (1) and (2), the actual value of the strip crown at the entry side of the rolling mill 1 (Cr _{i- Since} the control amount P _B and the control change amount ΔP _B of the work roll bender pressure can be calculated while adding ₁ ), the accuracy is improved.

[Rolling control device]
The control device 2 constituting the rolling control device according to the embodiment of the present invention is specifically realized by a general-purpose information processing device such as a personal computer or a workstation, and includes, for example, a CPU, a ROM, a RAM, and the like. Main components. The control device 2 includes a control amount calculation unit 21, a control change amount calculation unit 22, and a control unit 23.

  The control amount calculation unit 21 calculates the control amount of the work roll bender pressure by the work roll benders 13 and 14 when controlling the sheet crown of the material W to be rolled. The control amount calculation unit 21 calculates the control amount of the work roll bender pressure in each scene before starting the rolling of the material W to be rolled and during rolling.

For example, the control amount calculation unit 21 calculates the control amount P _B of the work roll bender pressure based on the following formula (1) before the rolling of the workpiece W is started. Then, the control amount calculation unit 21 outputs the calculated control amount P _B of the work roll bender pressure to the control unit 23.

Here, in the above formula (1), Cr _i is the target value of strip crown on delivery side of the rolling mill 1, Cr _i-1 calculated values or actual value of the strip crown at the entry side of the rolling mill 1, [Delta] CR is the A plate crown correction term for correcting the influence of the breadth of the rolled material W, α is a transfer rate, and the deflection of the work rolls 11 and 12 when a uniform load is applied in the width direction of the work rolls 11 and 12 effect ratio on plate crown, beta is a genetic factor, the effect ratios of the strip crown before rolling on the strip crown after rolling, Ic _P is the work rolls 11 and 12 deflected by the rolling load influence coefficient, P _R is the rolling Load, Ic _B is an influence coefficient that the work rolls 11 and 12 are deflected by the work roll benders 13 and 14, WR _profile is a work roll profile when there is no load, and Ic _W is when there is no load Is an influence coefficient of the work roll profile of the present invention on the rolled sheet crown.

Incidentally, the above-mentioned Cr _i is input by referring to a table or the like for the previously prepared target value. In addition, the above-described Cri _-1 is an exit-side plate crown in the previous pass when the thickness gauge 18 is not provided on the entry side of the rolling mill 1, and a calculated value obtained in advance is input. On the other hand, when the plate thickness meter 18 is provided on the entry side of the rolling mill ₁ , the above-mentioned Cri _-1 is input with the actual value (measured value) of the plate crown measured by the plate thickness meter 18. The Further, the above-described ΔCr, α, β, Ic _P , Ic _B , WR _profile , and Ic _W are obtained in advance by calculation based on rolling conditions and the like. Further, the P _R, 0 for a pre-rolling is input.

The control amount calculation unit 21 calculates the control amount P _B of the work roll bender pressure at a predetermined control cycle based on the above formula (1) after the rolling mill 1 starts rolling the material to be rolled W. To do. At this time, the control amount calculation unit 21 obtains the rolling load P _R during rolling from the load cell 17, by substituting the above equation (1), the control amount of the work roll bender pressure in consideration of the rolling load P _R P _B is calculated. Then, the control amount calculation unit 21 outputs the calculated control amount P _B of the work roll bender pressure to the control unit 23.

Furthermore, the control amount calculation unit 21, as described later, during the rolling of the rolled material W by the rolling mill 1 (the same rolling path), the target value Cr _i of the strip crown has been measured by the thickness gauge 18 When there is a difference between the measured value Cr _Fb of the plate crown, the workpiece calculated by the control change amount calculation unit 22 described later with respect to the control amount P _B of the work roll bender pressure calculated by the above formula (1). The roll bender pressure control change amount ΔP _B is added. Then, the control amount calculation unit 21 outputs the calculated control amount P _B + ΔP _B of the work roll bender pressure to the control unit 23. A method for calculating the control change amount ΔP _B will be described later.

Control correction amount calculation unit 22, during the rolling of the rolled material W by the rolling mill 1 (the same rolling path), the target value Cr _i of the strip crown, measurements Cr strip crown measured by the thickness gauge 18 determining whether a difference there is between _fb, if there is a difference _(| Cr _{i -Cr} Fb | if a> 0), in accordance with the following equation (2), the control changes to work roll bender pressure The amount ΔP _B is calculated. Then, the control change amount calculation unit 22 outputs the calculated control change amount ΔP _B of the work roll bender pressure to the control amount calculation unit 21.

Here, in the above formula (2), Cr _Fb is a measured value of the sheet crown after rolling measured by the sheet thickness meter 18.

The control unit 23 controls the work roll bender pressure of the work roll benders 13 and 14 based on the control amount input from the control amount calculation unit 21. Specifically, the control unit 23 is based on the control amount P _B calculated by the control amount calculation unit 21 at a predetermined control cycle during rolling of the material W to be rolled by the rolling mill 1 (within the same rolling pass). Control the work roll bender pressure. The control unit 23, during the rolling of the rolled material W by the rolling mill 1 (the same rolling path), the target value Cr _i of the strip crown, measurements Cr _Fb strip crown measured by the thickness gauge 18 , The work roll bender pressure is controlled based on the control amount P _B + ΔP _B calculated by the control amount calculation unit 21.

The work roll bender pressure control amount P _B and the control change amount ΔP _B described above are calculated in consideration of the plate crown correction term ΔCr, as shown in the above equations (1) and (2). Therefore, both the control amount P _B and the control change amount ΔP _B are values in which the influence due to the breadth of the material to be rolled W is corrected. The above-described plate crown correction term ΔCr is set in consideration of at least the plate thickness, plate width, deformation resistance, and rolling reduction of the material to be rolled. Therefore, the influence of the width of the material to be rolled W on the control amount P _B and the control change amount ΔP _B is corrected in consideration of at least the plate thickness, plate width, deformation resistance and rolling reduction of the material to be rolled.

[Rolling control method]
A rolling control method using the rolling control apparatus according to the present embodiment will be described with reference to FIG. As shown in the figure, among steps S1 to S7 included in the rolling control method, steps S1 and S2 are performed before starting rolling by the rolling mill 1, and steps S3 to S7 are during rolling by the rolling mill 1 ( In the same rolling pass and at a predetermined control cycle after the start of rolling).

First, the control unit 2, the start rolling before the rolled material W, with reference to the previously prepared table or the like, to determine the desired strip crown (target strip crown) Cr _i (step S1). Subsequently, the control amount calculation unit 21 of the control device 2 calculates the control amount P _B of the work roll bender pressure based on the above-described equation (1) (step S2).

Subsequently, after the rolling of the material to be rolled W is started, the control unit 23 of the control device 2 performs the work rolls of the work roll benders 13 and 14 based on the control amount P _B input from the control amount calculation unit 21. The bender pressure is controlled (step S3). Subsequently, the plate thickness meter 18 measures a plate crown (measured value of the plate crown) Cr _Fb on the exit side of the rolling mill 1 (step S4).

Subsequently, the control correction amount calculation unit 22 of the control device 2, there is a difference between the target value Cr _i strip crown determined in step S1, a measured value Cr _Fb of the measured strip crown in step S4 Or not (| Cr _i -Cr _Fb |> 0) is determined (step S5).

If there is no difference between the target value Cr _i and measured values _{Cr Fb} strip crown of the strip crown (No in step S5), and ends the process. On the other hand, if there is a difference between the target value Cr _i and plate measurement _{Cr Fb} crown strip crown (Yes in step S5), and the control correction amount calculation unit 22, based on the equation (2), A control change amount ΔP _B of the work roll bender pressure is calculated (step S6).

Subsequently, the control amount calculation unit 21 of the control device 2 adds the control change amount ΔP _B calculated in step S6 to the control amount P _B calculated in step S2, thereby obtaining the work roll bender pressure. The control amount is recalculated (step S7). Then, returning to step S3, the work roll bender pressures of the work roll benders 13 and 14 are controlled based on the recalculated control amount P _B + ΔP _B. Thereafter, steps S3 to S7 are repeated at a predetermined control cycle.

[Steel plate manufacturing method]
Here, in FIG. 2, the steps included in the rolling control method using the rolling control apparatus have been described. However, in addition to these steps, a rolling step by the rolling mill 1 is included, so that the steel plate manufacturing method is implemented. Is also possible.

According to the rolling control method, the steel plate manufacturing method, the rolling control device, and the steel plate manufacturing device according to this embodiment as described above, the plate crown is measured during rolling of the material W and the measured value is used. Then, control (dynamic control) is performed to reflect the change in rolling conditions on the tail end side (the tail end side from the measurement point of the plate crown) in the same material to be rolled W. That is, in the same rolling path of the rolled material W, when the difference occurs between the target value Cr _i of the strip crown and the measured value Cr _Fb, each time, correcting the control amount of the work roll bender 13 To do. Therefore, according to the rolling control method, the steel plate manufacturing method, the rolling control device, and the steel plate manufacturing device according to this embodiment, control can be performed so that a desired plate crown is obtained over the entire length of the material to be rolled W.

  Hereinafter, the present invention will be described more specifically with reference to examples. In this example, two steel plates having the same dimensions (plate thickness 7.88 mm, plate width 3220 mm) and the same deformation resistance were prepared, rolled to the same thickness with a roughing mill, conveyed to a finishing mill, Was rolled at a target value of 0.040 mm. Then, after rolling, the difference between the plate thickness at the center in the width direction and the plate thickness at the end in the width direction of each steel plate is measured by a γ-ray plate thickness meter arranged at the position of the exit side 14 m of the finish rolling mill, The crown was evaluated.

  FIG. 3A is a full length chart of the plate crown when only the conventional rolling control method, that is, steps S1 to S3 of the steps described in FIG. 2 are performed. FIG. 3B is a full length chart of the plate crown when the rolling control method according to the present invention (see FIG. 2) is performed. In FIGS. 3A and 3B, the vertical axis represents the plate crown, and the horizontal axis represents the plate length.

  As shown in FIG. 3A, it can be seen that in the conventional rolling control method, the plate crown is not properly controlled, and the plate crown increases as the plate length increases. On the other hand, as shown in FIG. 3B, in the rolling control method according to the present invention, the plate crown is within a substantially constant range regardless of the plate length, and the plate crown can be appropriately controlled. Recognize.

  As described above, the rolling control method, the steel sheet manufacturing method, the rolling control apparatus, and the steel sheet manufacturing apparatus according to the present invention have been specifically described by the embodiments and examples for carrying out the invention. It is not limited to the description, but should be interpreted broadly based on the description of the scope of claims. Needless to say, various changes and modifications based on these descriptions are also included in the spirit of the present invention.

  For example, in the above-described rolling control device and steel plate manufacturing device, as shown in FIG. 1, the work roll benders 13 and 14 are shown as an example of the plate crown control mechanism, but the plate crown control mechanism can control the plate crown. It only has to be configured. The plate crown control mechanism may be composed of, for example, a plurality of actuators divided in the axial direction of the work rolls 11 and 12.

1 Rolling mill 11, 12 Work roll 13, 14 Work roll bender (plate crown control mechanism)
DESCRIPTION OF SYMBOLS 15,16 Backup roll 17 Load cell 18 Plate thickness meter 2 Control apparatus 21 Control amount calculation part 22 Control change amount calculation part 23 Control part W Rolling material

Claims (10)

A plate crown control mechanism capable of controlling a plate crown indicating a plate thickness distribution in the width direction of the material to be rolled;
A thickness meter that is installed on the exit side of the rolling mill and measures the sheet crown on the exit side of the rolling mill by measuring the thickness of at least two points in the width direction of the material to be rolled;
In a rolling control method of a rolling mill comprising:
When there is a difference between the preset target value of the plate crown and the measured value of the plate crown measured by the plate thickness meter during rolling by the rolling mill, in the same rolling pass, A rolling control method, wherein a control amount when the plate crown control mechanism controls the plate crown is changed by a control change amount calculated based on the difference.   If there is a difference between a preset target value of the plate crown and a measured value of the plate crown measured by the plate thickness meter in the same rolling pass, the plate crown control mechanism 2. The control amount when controlling the crown and the control change amount calculated based on the difference are both corrected for the influence due to the breadth of the material to be rolled. Rolling control method.   The rolling control method according to claim 2, wherein the influence due to the breadth of the material to be rolled is corrected in consideration of at least a plate thickness, a plate width, a deformation resistance, and a reduction ratio of the material to be rolled. . When there is a difference between the preset target value of the plate crown and the measured value of the plate crown measured by the plate thickness meter in the same rolling pass, the following formula (1) is given. the control quantity P _B, the rolling control method as claimed in any one of claims 3, characterized by adding a controlled change amount [Delta] P _B represented by the following formula (2).

(However, in the above formula (1) and the formula (2), Cr _i is the target value of strip crown on delivery side of the rolling mill, Cr _i-1 calculated values or actual value of the strip crown at the entry side of the rolling mill , ΔCr is a sheet crown correction term that corrects the influence of the spread of the material to be rolled, α is an influence ratio of the deflection of the work roll when a uniform load is applied in the width direction of the work roll on the sheet crown after rolling, β effect ratios strip crown before rolling on the strip crown after rolling, Ic _P influence coefficient bend the work roll by the rolling load, P _R is the rolling load, influence coefficient Ic _B is the work roll bends the strip crown control mechanism , WR _profile is a work roll profile under no load, and Ic _W is an influence coefficient of the work roll profile under no load on the sheet crown after rolling. In the above formula (2), Cr _Fb is a measured value of the rolled sheet crown measured by a sheet thickness meter)   The manufacturing method of the steel plate characterized by including the rolling control method as described in any one of Claims 1-4. A plate crown control mechanism capable of controlling a plate crown indicating a plate thickness distribution in the width direction of the material to be rolled;
A thickness meter that is installed on the exit side of the rolling mill and measures the sheet crown on the exit side of the rolling mill by measuring the thickness of at least two points in the width direction of the material to be rolled;
In a rolling control device of a rolling mill comprising:
When there is a difference between the preset target value of the plate crown and the measured value of the plate crown measured by the plate thickness meter during rolling by the rolling mill, in the same rolling pass, A rolling control apparatus, wherein a control amount when the plate crown control mechanism controls the plate crown is changed by a control change amount calculated based on the difference.   If there is a difference between a preset target value of the plate crown and a measured value of the plate crown measured by the plate thickness meter in the same rolling pass, the plate crown control mechanism The control amount for controlling the crown and the control change amount calculated based on the difference are both corrected for the influence of the breadth of the material to be rolled. Rolling control device.   The rolling control according to claim 7, wherein the influence of the breadth of the material to be rolled is corrected in consideration of at least a plate thickness, a plate width, a deformation resistance, and a rolling reduction rate of the material to be rolled. apparatus. When there is a difference between the preset target value of the plate crown and the measured value of the plate crown measured by the plate thickness meter in the same rolling pass, the following formula (1) is given. the control quantity P _B, the rolling control apparatus according to any one of claims 8 from claim 6, wherein the adding a control change amount [Delta] P _B represented by the following formula (2).

(However, in the above formula (1) and the formula (2), Cr _i is the target value of strip crown on delivery side of the rolling mill, Cr _i-1 calculated values or actual value of the strip crown at the entry side of the rolling mill , ΔCr is a sheet crown correction term that corrects the influence of the spread of the material to be rolled, α is an influence ratio of the deflection of the work roll when a uniform load is applied in the width direction of the work roll on the sheet crown after rolling, β effect ratios strip crown before rolling on the strip crown after rolling, Ic _P influence coefficient bend the work roll by the rolling load, P _R is the rolling load, influence coefficient Ic _B is the work roll bends the strip crown control mechanism , WR _profile is a work roll profile under no load, and Ic _W is an influence coefficient of the work roll profile under no load on the sheet crown after rolling. In the above formula (2), Cr _Fb is a measured value of the rolled sheet crown measured by a sheet thickness meter)   A steel plate manufacturing apparatus comprising the rolling control apparatus according to any one of claims 6 to 9.

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