JP5765456B1 - Control device and control method for rolling mill - Google Patents

Abstract

An object of the present invention is to meander a rolled material in both cases where the rolled material does not have camber but the rolled material is entirely off-center and when the rolled material has camber. To suppress it. A control apparatus 101 is configured to control a finish first stand 3a based on an off-center amount measured by an off-center amount measuring device 102 until a leading end of a material to be rolled passes the finish first stand 3a. A reduction leveling amount is set, and after the tip of the material to be rolled has passed through the finishing first stand 3a, the reduction leveling amount of the finishing first stand 3a is adjusted according to the camber amount measured by the camber amount measuring device 103. For the rolling stands after the finishing second stand 3b, the reduction position is adjusted so that the gaps between the work rolls are equal on the working side and the driving side based on the rolling conditions and the difference in the left and right mill rigidity of each stand. [Selection] Figure 1

Description

  The present invention relates to a control device and a control method for a rolling mill in a hot rolling line.

  When rolling a material to be rolled such as a steel plate, the material to be rolled is not stably present at the center in the width direction of the rolling mill, and moves to the end in the width direction of the rolling mill as the rolling proceeds. May occur. This phenomenon is generally called “meandering”.

  When the material to be rolled is meandering, the tail end portion of the material to be rolled collides with the side guide when it exits the upstream rolling mill, and the downstream side rolling with the width direction end portion of the material to be rolled folded. By rolling with a mill, a defect called narrowing may occur.

  In addition, when the material to be rolled is off-centered by meandering during rolling (the center position in the width direction moves to the driving side or the working side), the load balance changes to change the gap between the rolling rolls in the left-right direction (driving side / work Side), the off-center amount of the material to be rolled is further increased, and the meandering is expanded.

  Against this background, techniques for preventing meandering of the material to be rolled have been proposed.

  Specifically, in Patent Document 1, a meandering amount of a material to be rolled is detected using a meandering detector installed on one or both of the entry side and the exit side of a rolling mill, and detected by the meandering detector. A technique for controlling the rolling leveling amount of the rolling mill based on the meandering amount is described.

  Patent Document 2 describes a technique for measuring or estimating a camber amount and a thickness wedge amount of a material to be rolled on the entry side of a rolling mill, and setting a rolling leveling amount of the rolling mill based on the measurement or estimation result. Has been.

JP-A-8-318305 JP 2002-126913 A

  When meandering occurs on the entry side or exit side of the rolling mill, no bending in the longitudinal direction (hereinafter referred to as camber) occurs in the material to be rolled, but the material to be rolled is off-center as a whole. There is a case where the camber is generated in the material to be rolled and a case where the material is rolled.

  The technique described in Patent Document 1 is considered to work appropriately for the former case. However, according to the technique described in Patent Document 1, in the latter case, depending on whether the shape of the camber is an arc shape or an S-shaped bend, depending on the meandering amount of the material to be rolled on the entrance side of the rolling mill Further, there is a possibility that control of the amount of reduction leveling may be inappropriate for subsequent meandering control at the position of the material to be rolled.

  On the other hand, the technique described in Patent Document 2 does not have a control effect for the former case, that is, no camber is generated in the material to be rolled, but the material to be rolled is entirely off-center.

  The present invention has been made in view of the above-mentioned problems, and its purpose is that no camber is generated in the material to be rolled, but the material to be rolled is entirely off-center and the camber in the material to be rolled. It is an object of the present invention to provide a control device and a control method for a rolling mill that can prevent the material to be rolled from meandering in any case.

  The inventors of the present invention, in order to suppress the meandering of the material to be rolled in the finish rolling mill, the influence of the off-center amount of the material to be rolled with respect to the meander, the relationship between the camber amount and the off-center amount of the material to be rolled As a result of intensive studies on the meandering characteristics at each stand of the finishing mill, it has been found that there is an optimal control method.

  The rolling mill control device according to the present invention conceived based on the above knowledge includes an off-center amount measuring means for measuring the off-center amount of the tip of the material to be rolled on the first stand entry side of the finishing mill, rough rolling The camber amount measuring means for measuring the camber amount at each position in the longitudinal direction of the subsequent rolled material, and the off-center amount measured by the off-center amount measuring means until the leading end of the rolled material passes through the first stand. Based on the center amount, the leveling amount of the first stand is set, and after the tip of the material to be rolled has passed through the first stand, the first stand is set according to the camber amount measured by the camber amount measuring means. For the rolling stands after the second stand of the finishing mill with the reduction leveling amount adjusted, the work side is based on the rolling conditions and the difference in the left and right mill rigidity of each stand. And control means for adjusting the pressing position such that a gap of the rolling roll is equal at the drive side, characterized in that it comprises a.

  The rolling mill manufacturing apparatus according to the present invention includes, in the above invention, temperature measuring means for measuring a temperature distribution in the width direction of the material to be rolled on the first stand entrance side of the finish rolling mill, and the control means includes: Based on the off-center amount measured by the off-center amount measuring means and the temperature distribution in the width direction of the material to be rolled measured by the temperature measuring means until the tip of the material passes through the first stand. A reduction leveling amount of the first stand is set.

  The control method of the rolling mill according to the present invention conceived based on the above knowledge includes an off-center amount measuring step for measuring the off-center amount of the tip portion of the material to be rolled on the first stand entrance side of the finish rolling mill, Measured in the camber amount measuring step for measuring the camber amount at each position in the longitudinal direction of the rolled material after rolling and in the off-center amount measuring step until the tip of the rolled material passes through the first stand. Based on the off-center amount, the leveling amount of the first stand is set, and after the leading end of the material to be rolled has passed through the first stand, the first stand according to the camber amount measured in the camber amount measuring step. For rolling stands after the second stand of the finishing mill, the rolling conditions and the left and right mill rigidity of each stand are adjusted. Characterized in that it comprises a control step of adjusting a pressing position such that a gap of the rolling roll is equal at the working side and the driving side on the basis of.

  The rolling mill manufacturing method according to the present invention includes, in the above invention, a temperature measurement step of measuring a temperature distribution in a width direction of the material to be rolled on the first stand entrance side of the finish rolling mill, and the control step includes: Based on the off-center amount measured in the off-center amount measuring step and the temperature distribution in the width direction of the material to be rolled measured in the temperature measuring step until the tip of the material passes through the first stand. The method includes a step of setting a reduction leveling amount of the first stand.

  According to the control device and control method for a rolling mill according to the present invention, no camber is generated in the material to be rolled, but camber is generated in the material to be rolled when the material to be rolled is off-center as a whole. In any case, the meandering of the material to be rolled can be suppressed.

FIG. 1 is a schematic diagram showing a configuration of a hot rolling line to which a rolling mill control method according to an embodiment of the present invention is applied. FIG. 2 is a schematic diagram showing a configuration of a rolling mill that constitutes the finishing mill shown in FIG. FIG. 3 is a schematic diagram for explaining a mechanism in which the material to be rolled meanders. FIG. 4 is a diagram showing the definition of the camber amount when the material to be rolled is bent in an arc shape around the work side. FIG. 5 is a diagram showing the definition of the camber amount when the material to be rolled is bent in an S shape. FIG. 6 is a diagram illustrating an example of the camber amount measured on the exit side of the rough rolling mill. FIG. 7 is a diagram showing the meandering amount of the material to be rolled at each stand in the invention example and the comparative example. FIG. 8 is a diagram showing the rate of occurrence of meandering trouble when 20 materials to be rolled are rolled in the invention example and the comparative example.

  Hereinafter, with reference to drawings, the control method of the rolling mill which is one embodiment of the present invention is explained in detail.

[Configuration of hot rolling line]
First, a configuration of a hot rolling line to which a rolling mill control method according to an embodiment of the present invention is applied will be described.

  FIG. 1 is a schematic diagram showing a configuration of a hot rolling line to which a rolling mill control method according to an embodiment of the present invention is applied. As shown in FIG. 1, a hot rolling line 1 to which a rolling mill control method according to an embodiment of the present invention is applied includes a rough rolling mill along a conveyance direction (rolling direction) of a material to be rolled indicated by an arrow. 2 and a finishing mill 3.

  The rough rolling mill 2 includes three rolling stands, a rough first stand 2a, a rough second stand 2b, and a rough third stand 2b, and a material to be rolled up to the intermediate thickness is heated using these three rolling stands. Squeeze.

  The finish rolling mill 3 includes seven rolling stands, a finish first stand 3a to a finish seventh stand 3g, and uses the seven rolling stands to reduce the material to be rolled by the rough rolling mill 2 to a finish thickness. .

[Configuration of rolling mill]
Next, with reference to FIG. 2, the structure of the rolling mill which comprises the said finishing 1st stand 3a-the finishing 7th stand 3g is demonstrated.

  FIG. 2 is a schematic diagram showing a configuration of a rolling mill that constitutes the finishing first stand 3a to the finishing seventh stand 3g. As shown in FIG. 2, the rolling mill 10 constituting the finishing first stand 3a to the finishing seventh stand 3g is constituted by a rolling mill having a four-stage roll arrangement, and has two upper and lower work rolls 11a and 11b. And two upper and lower backup rolls 12a and 12b that support the work rolls 11a and 11b from above and below.

  The drive side and work side of the backup rolls 12a and 12b are rotatably supported by roll chocks 13a and 13b, respectively. The roll chocks 13a and 13b are respectively connected with reduction devices 14a and 14b configured by hydraulic cylinders, electric screws or the like. By applying a rolling force (also referred to as a sum load or simply a load) to the roll chock 13a, 13b from the rolling devices 14a, 14b, the material to be rolled S between the work rolls 11a, 11b can be rolled down.

  Reference numerals 15a and 15b in FIG. 2 indicate drive-side and work-side load cells for measuring the reduction force of the reduction devices 14a and 14b, respectively, and reference numerals 16a and 16b indicate drive-side and work-side housings, respectively. ing. Moreover, in this specification, the drive side means the width direction edge part side of the backup roll 12a, 12b connected with the electric motor for rotationally driving the backup roll 12a, 12b. The work side means the width direction end portion side of the backup rolls 12a and 12b on the opposite side to the drive side.

[Mechanism of meandering]
Next, with reference to FIG. 3, the mechanism by which the to-be-rolled material S meanders is demonstrated. In the following description, the amount of reduction by the reduction devices 14a and 14b is assumed to be zero when the work rolls 11a and 11b are in close contact with each other, and the amount of change in the reduction amount of the reduction devices 14a and 14b from there is tightened. Defined as quantity. Further, the tightening amounts on the driving side and the working side are defined as Ldr and Lop, respectively, and the deviation between the tightening amounts Ldr and Lop on the driving side and the working side is defined as the reduction leveling amount.

  If the thickness of the material to be rolled S is equal in the left-right direction (drive side / working side), the material to be rolled S is also left and right by setting the tightening amounts Ldr and Lop on the drive side and work side to the same size. The loads Pdr, Pop applied to the roll chocks 13a, 13b on the driving side and the working side are also equalized by being uniformly reduced. However, when the material to be rolled S is off-center during rolling, the load balance changes due to the balance of forces in the left-right direction.

  For example, referring to FIG. 3, when the center position Sc in the width direction of the material S to be rolled moves to the drive side relative to the center position Mc in the width direction of the work rolls 11a and 11b, it is added to the roll chock 13b on the work side. Load Pop becomes larger than the load Pdr applied to the roll chock 13a on the driving side, and the gap between the work rolls 11a and 11b becomes wider on the driving side. For this reason, the side with the smaller roll gap of the material to be rolled S, that is, the working side is rolled thinly. As a result, the elongation in the longitudinal direction on the work side of the material to be rolled S is increased. Furthermore, it moves to the drive side. This is the mechanism by which the material to be rolled S meanders.

[Rolling mill control method]
Next, the control method of the rolling mill which is one Embodiment of this invention is demonstrated. In the following, the camber amount of the camber bent in an arc shape with the work side as the center is the center position in the width direction with the center position Sc in the width direction of the tip portion of the material S to be rolled as a reference position, as shown in FIG. The deviation Cx is defined. Similarly, the camber amount of the camber bent in an S shape is defined by a deviation Cx in the width direction center position with the width direction center position Sc of the tip of the material S to be rolled as a reference position, as shown in FIG. .

  In FIG. 3, when the off-center amount of the material to be rolled S is defined by the deviation Yc between the width direction center position Mc of the work rolls 11a and 11b and the width direction center position Sc of the material to be rolled S, it is added to the roll chock 13a on the driving side. The deviation (difference load) Pdef between the applied load Pdr and the load Pop applied to the work side roll chock 13b is expressed as the following formula (1). Here, P represents a rolling load, and L represents a distance between the rolling devices 14a and 14b (see FIG. 2) for rolling down the roll chock 13a and 13b.

  The reduction leveling amount ΔL, which is the adjustment amount of the reduction position between the driving side and the working side, is expressed by the following equation (2) when the tightening amounts in the reduction devices 14a and 14b are expressed as Ldr and Lop, respectively. It is expressed as Here, if the tightening amount in the reduction devices 14a and 14b is increased, the gap between the work rolls 11a and 11b is reduced.

  On the other hand, the ratio between the reduction leveling amount ΔL and the differential load Pdef is defined as parallel stiffness K, and is expressed as the following formula (3).

  Therefore, when the off-center amount Yc occurs in the material to be rolled S, the reduction leveling amount ΔL necessary for preventing the material to be rolled S from meandering further (the off-center amount does not increase) is expressed by the following equation (4). It becomes like this. In addition, the value of the parallel rigidity K1 and the distance L in Formula (4) can be calculated in advance according to the type of the rolling mill 10, and the rolling load P is a deformation resistance, a rolling reduction rate, etc. of the material S to be rolled. Predictive calculation can be performed before rolling according to rolling conditions.

  Then, in the control method of the rolling mill which is one embodiment of the present invention, as shown in FIG. 1, the control device 101 before the tip of the material to be rolled S reaches the finishing first stand 3a, The off-center amount Yc of the material to be rolled S on the entry side of the finishing first stand 3a is measured using the off-center amount measuring device 102 installed on the entry side of the finishing first stand 3a, and the measured off-center amount is measured. The reduction leveling amount ΔL is calculated by substituting Yc into the above equation (4). Then, the control device 101 sets the reduction leveling amount ΔL of the finishing first stand 3a to the calculated reduction leveling amount ΔL.

  In addition, when there exists temperature distribution in the width direction of the to-be-rolled material S, since the deformation resistance of the to-be-rolled material S changes in the width direction, when the differential load Pdef occurs, the reduction leveling amount ΔL is affected. Therefore, it is desirable to measure the temperature distribution in the width direction of the material to be rolled S using the temperature measuring device 104 and set the reduction leveling amount ΔL based on the measured temperature distribution.

  Specifically, assuming that the temperature distribution in the width direction of the material S to be rolled and the distribution of deformation resistance caused by this temperature distribution change linearly, the differential load Pdef due to the temperature distribution in the width direction is expressed by the following formula (5 ). Here, in Equation (5), b represents the sheet width of the material to be rolled S, KFop represents the deformation resistance of the work side end of the material to be rolled S, and KFdr represents the deformation resistance of the end of the drive side of the material to be rolled S. ing.

  In general, as the value of the deformation resistance of the material to be rolled S in the hot rolling operation, a value calculated and set by a model equation or a table that parameters the chemical composition or temperature of the material to be rolled S is used. Therefore, the value of the parameter KFdr / KFop in Equation (5) can be calculated using the chemical composition of the material to be rolled S and the temperature distribution in the width direction of the material to be rolled S measured by the temperature measuring device 104. .

  Therefore, when there is a temperature distribution in the width direction of the material S to be rolled, the differential load due to the temperature distribution in the width direction calculated by Equation (5) is added to the differential load Pdef due to off-center calculated by Equation (1). A value obtained by adding Pdef may be used. That is, the reduction leveling amount ΔL at this time is expressed as the following formula (6).

  Furthermore, when a camber occurs in the material S to be rolled, an off-center occurs at the finishing first stand 3a as the rolling progresses. It is possible to measure the off-center at the entrance side of the finishing first stand 3a and control the reduction leveling amount. In this case, however, an uncontrolled part occurs due to a time delay from measurement to control, and the rolling speed is particularly high. The effect becomes significant in the fast steady part.

  So, in the control method of the rolling mill which is one embodiment of the present invention, the control device 101 is set to the exit side of the rough rolling mill 2 after the leading end of the material S to be rolled passes through the finishing first stand 3a. The camber amount Cx at each position in the longitudinal direction of the material S after rough rolling is measured using the measured camber measuring device 103, and the measured camber amount Cx is substituted into the following equation (7). To calculate a reduction leveling amount ΔL ′. Then, the control device 101 controls the reduction leveling amount of the finishing first stand 3a according to the calculated reduction leveling amount ΔL ′.

  That is, the control device 101 finishes according to the off-center amount Yc of the center position Sc in the width direction of the tip end of the material to be rolled S until the tip end of the material to be rolled S reaches the finishing first stand 3a. A reduction leveling amount ΔL of the first stand 3a is set. And after the front-end | tip part of the to-be-rolled material S passes the finishing 1st stand 3a, the control apparatus 101 finishes 1st according to the camber amount Cx in each position of the longitudinal direction of the to-be-rolled material S after rough rolling. The reduction leveling amount of the stand 3a is adjusted to the reduction leveling amount ΔL ′. On the other hand, for the finishing second stands 3b to 3g, the control device 101 makes the gaps between the work rolls 11a and 11b equal on the working side and the driving side based on the rolling conditions and the left and right mill rigidity differences between the stands. Adjust the reduction position. Thereby, the to-be-rolled material S can be rolled down, suppressing meandering, without generating the uncontrolled part by time delay. Here, in this embodiment, the reduction position is adjusted so that the gap between the work rolls 11a and 11b is equal on the work side and the drive side, but the gap between the work rolls 11a and 11b is different between the work side and the drive side. Need not be exactly equal. That is, the gap between the work rolls 11a and 11b may be slightly different between the work side and the drive side as long as the meandering amount of the material to be rolled S is within the allowable range. It is good if they are equal.

  The camber measuring device 103 has an imaging device that measures the position in the width direction of the material to be rolled S at three positions in the longitudinal direction of the material to be rolled S, and the curvature of the material to be rolled S along with the conveyance of the material to be rolled S. It is desirable to use the one that calculates the camber amount at each position in the longitudinal direction of the material to be rolled S by measuring. In addition, when there is a difference in the left and right mill rigidity of the rolling mill, the following is shown in order to adjust the reduction position to the same work roll gap on the working side and the driving side based on the difference in the left and right mill rigidity of the rolling mill. The reduction leveling amount ΔL may be adjusted by using a conventionally used mathematical expression as represented by the mathematical expression (8). In Equation (8), Kdr and Kop indicate the driving and working mill constants, respectively.

  As is apparent from the above description, in the control method for a rolling mill according to an embodiment of the present invention, the control device 101 is in a period until the leading end of the material to be rolled S reaches the finishing first stand 3a. After setting the reduction leveling amount of the finishing first stand 3a based on the off-center amount measured by the off-center amount measuring device 102, the camber amount is reached after the tip of the material S reaches the finishing first stand 3a. The reduction leveling amount of the finishing first stand 3a is adjusted according to the camber amount measured by the measuring device 103. For the rolling stands after the finishing second stand 3b, the rolling conditions and the difference in the left and right mill rigidity of each stand are used. Thus, the reduction position is adjusted so that the gaps between the work rolls are equal on the work side and the drive side. Thereby, although the camber has not generate | occur | produced in the to-be-rolled material S, although the to-be-rolled material S is entirely off-center, and the case where the camber has generate | occur | produced in the to-be-rolled material S The material S can be prevented from meandering.

  An embodiment in which the present invention is applied to a finishing mill consisting of 7 stands will be described. The diameter and trunk length of the work roll of the finishing mill in this example are 800 mm and 2000 mm, respectively, and the diameter and trunk length of the backup roll are 600 mm and 2000 mm, respectively. The distance between the load fulcrums is 3000 mm. In addition, a sensor for measuring the off-center amount at the front end of the material to be rolled and a temperature measuring device for measuring the temperature distribution in the width direction of the material to be rolled are installed on the entrance side of the finishing mill. A sensor for measuring the amount of camber of the material to be rolled is installed on the exit side of the rolling mill. The conditions such as the mill constant of the finish rolling mill are as shown in Table 1 below.

  Further, the material to be rolled is a low carbon steel plate having a plate width of 1500 mm, the inlet side plate thickness and the outgoing side plate thickness are set to 40 mm and 2 mm, respectively, and 20 to 40% of rolling is performed in each stand. At this time, the rolling load is predicted to be 20000 kN according to a theoretical rolling formula that is practically used in industry, and the parallel rigidity K1 is 4000 kN / mm. Note that the camber amount of the material to be rolled measured by a sensor installed on the exit side of the roughing mill was as shown in FIG. Moreover, the off-center amount of the front-end | tip part of the to-be-rolled material measured by the sensor installed in the entrance side of a finishing mill was 20 mm to the drive side. Further, the temperature distribution in the width direction of the material to be rolled is about 30 ° C. between the working side end and the driving side end, and the deformation resistance KFdr at the driving side end of the material to be rolled S and the working side of the material to be rolled. The ratio KFdr / KFop to the end portion deformation resistance KFop was 1.05. Hereinafter, the meandering amount is positive when it is off-centered on the driving side.

[Invention Example]
In Invention Example 1, the reduction leveling amount at the finishing first stand was set according to the following procedure. That is, first, the rolling load when the material to be rolled was rolled was predicted. The rolling load should be calculated using the rolling load calculation model formula used industrially, with the material conditions such as the chemical composition and temperature of the material to be rolled and the rolling conditions such as the rolling roll diameter and rolling speed as input information. Can do. Next, in Invention Example 1, the reduction leveling amount ΔL1 of the finishing first stand (main) from the off-center amount of the leading end of the material to be rolled measured on the entry side of the finishing mill using the above-described formula (4). In the example, 0.067) was calculated. Further, in Invention Example 2, the reduction leveling amount −0.02 based on the temperature distribution in the width direction of the material to be rolled was calculated using Equation (6).

  Next, the leveling amount ΔL2 (0.057 in this example) for compensating for the elastic deformation on the driving side and the working side of the finishing first stand was calculated using the above formula (8). Next, the reduction leveling amount of the finishing first stand was set to the sum of the reduction leveling amount L1 and the reduction leveling amount ΔL2 (0.124 in this example). Next, after the finishing second stand, the reduction leveling amount was set based on the rolling load of each stand and the spring constant difference of the housing of each stand. And during rolling, the reduction leveling amount of the finishing first stand was adjusted using the above-mentioned equation (7) according to the camber amount measured on the exit side of the roughing mill. In addition, after the second finishing stand, the reduction position was adjusted so that the gaps between the work rolls were equal on the drive side and the work side based on the difference between the left and right mill rigidity of the rolling mill.

[Comparative Example 1]
In Comparative Example 1, the reduction leveling amount was proportionally controlled so as to compensate for the difference in stiffness between the left and right sides based on the mill constant of each stand. The rolling load at each stand was calculated using a rolling load calculation model formula as in the invention example. In addition, the reduction leveling amount was not set or adjusted according to the off-center amount of the front end portion of the material to be rolled on the entry side of the finishing mill.

[Comparative Example 2]
In Comparative Example 2, no control was performed while the reduction leveling amount was set so that the difference between the left and right work roll openings was equal.

[Evaluation]
FIG. 7 is a view showing a meandering state of the material to be rolled at each stand in Invention Examples 1 and 2 and Comparative Examples 1 and 2. In addition, the amount of meandering has shown the locus | trajectory of the width direction center position of the tail end part of the to-be-rolled material image | photographed with the television camera installed above between stands. As shown in FIG. 7, in Comparative Example 2, meandering started with the progress of the material to be rolled, and the amount of meandering increased as it was. In Comparative Example 2, the material to be rolled contacted the side stand after the finishing third stand, and the edge portion was folded. Similarly, the amount of meandering in Comparative Example 1 was smaller than that in Comparative Example 2, but the amount of meandering increased as the finisher stand was reached. On the other hand, in Invention Example 1, the initial off-center amount was maintained, and the meandering was hardly performed thereafter. In Invention Example 2, since the influence of the temperature distribution in the width direction of the material to be rolled could be removed, the meandering was further suppressed.

  FIG. 8 is a diagram showing the rate of occurrence of meandering troubles when 20 materials to be rolled are rolled in Invention Examples 1 and 2 and Comparative Examples 1 and 2, respectively. Here, the occurrence of a meandering trouble means that a quality trouble or a bending of the rolled material has occurred due to the end in the width direction of the rolled material contacting the side guide. As shown in FIG. 8, meandering troubles occurred in Comparative Examples 1 and 2, whereas no meandering troubles occurred in Invention Examples 1 and 2.

  From the above, according to the present invention, no camber is generated in the material to be rolled, but either the case where the material to be rolled is off-center as a whole or the case where camber is generated in the material to be rolled. In some cases, it was confirmed that the material to be rolled can be prevented from meandering.

  The embodiment to which the invention made by the present inventors is applied has been described above, but the present invention is not limited by the description and the drawings that constitute a part of the disclosure of the present invention. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Hot rolling line 2 Rough rolling mill 3 Finish rolling mill 10 Rolling mill 11a, 11b Work roll 12a, 12b Backup roll 13a, 13b Roll chock 14a, 14b Rolling device 15a, 15b Rolling device 16a, 16b Housing 101 Control device 102 Off center Quantity measuring instrument 103 Camber quantity measuring instrument 104 Temperature measuring instrument S Rolled material

Claims (4)

Off-center amount measuring means for measuring the off-center amount of the tip of the material to be rolled on the first stand entrance side of the finishing mill,
A camber amount measuring means for measuring a camber amount at each position in the longitudinal direction of the material to be rolled after rough rolling;
The rolling leveling amount of the first stand is set based on the off-center amount measured by the off-center amount measuring means until the tip portion of the material to be rolled passes through the first stand, and the tip of the material to be rolled is After the section has passed the first stand, the leveling amount of the first stand is adjusted according to the camber amount measured by the camber amount measuring means, and the rolling stands after the second stand of the finishing mill are rolled. Control means for adjusting the reduction position so that the gap between the rolling rolls is equal on the working side and the driving side based on the conditions and the difference in the left and right mill rigidity of each stand;
A control device for a rolling mill, comprising:   The temperature measuring means for measuring the temperature distribution in the width direction of the material to be rolled on the first stand entrance side of the finish rolling mill is provided, and the control means is provided until the tip of the material to be rolled passes through the first stand. The reduction leveling amount of the first stand is set based on the off-center amount measured by the off-center amount measuring unit and the temperature distribution in the width direction of the material to be rolled measured by the temperature measuring unit. The control apparatus of the rolling mill of Claim 1. An off-center amount measuring step for measuring the off-center amount of the tip of the material to be rolled on the first stand entrance side of the finishing mill;
A camber amount measuring step for measuring the camber amount at each position in the longitudinal direction of the material to be rolled after rough rolling;
A rolling leveling amount of the first stand is set based on the off-center amount measured in the off-center amount measuring step until the tip portion of the material to be rolled passes through the first stand, and the tip of the material to be rolled is After the section has passed the first stand, the leveling amount of the first stand is adjusted according to the camber amount measured in the camber amount measuring step, and the rolling stands after the second stand of the finishing mill are rolled. A control step of adjusting the reduction position so that the gaps of the rolling rolls are equal on the working side and the driving side based on the conditions and the left and right mill rigidity differences of each stand;
A control method for a rolling mill, comprising:   A temperature measurement step of measuring a temperature distribution in a width direction of the material to be rolled on the first stand entrance side of the finishing mill, wherein the control step is performed until the tip of the material to be rolled passes through the first stand. Including a step of setting a reduction leveling amount of the first stand based on the off-center amount measured in the off-center amount measuring step and the temperature distribution in the width direction of the material to be rolled measured in the temperature measuring step. The method of controlling a rolling mill according to claim 3, wherein

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