Title of the invention: Rolling machine and setting method of rolling machine
Technical field
[0001]
　The present invention relates to a rolling mill for rolling a material to be rolled and a method for setting the rolling mill.
Background technology
[0002]
　As a phenomenon that causes a sheet passing trouble in the hot rolling process, for example, there is meandering of a steel plate. One of the factors that cause the steel sheet to meander is the thrust force generated by a minute cloth (also referred to as roll skew) between the rolls of the rolling mill, but it is difficult to directly measure the thrust force. Therefore, the thrust reaction force conventionally detected as the reaction force of the total value of the thrust forces generated between the rolls is measured, or the cross angle between the rolls that causes the thrust force is measured, and the thrust reaction force or the thrust reaction force or It has been proposed to identify the thrust force generated between the rolls based on the cross angle to control the meandering of the steel plate.
[0003]
　For example, in Patent Document 1, the thrust reaction force in the roll axis direction and the load in the rolling direction are measured, one or both of the rolling zero and the deformation characteristics of the rolling mill are obtained, and the rolling position is set at the time of rolling. A plate rolling method for rolling control is disclosed. Further, in Patent Document 2, the thrust force generated in the roll is calculated based on the minute cross (skew angle) between rolls measured by using the distance sensor provided inside the rolling mill, and the reduction is performed based on the thrust force. A meandering control method is disclosed in which a difference load component due to meandering is calculated from a load measurement value in a direction to control reduction leveling. Further, Patent Document 3 discloses a cross point correction device for correcting a deviation of a point (cross point) where the central axes of the upper and lower rolls intersect in the horizontal direction in a pair cross rolling mill. Such an apparatus includes an actuator that absorbs play generated between the crosshead and the roll chock, and a detector that detects the roll chock position, and corrects the deviation of the cross point based on the roll chock position.
[0004]
　Further, in Patent Document 4, when the load difference between the driving side and the operating side is detected and the meandering of the rolled material is controlled by independently operating the rolling position between the driving side and the operating side based on the detected load difference. By estimating the differential load due to the thrust during rolling, the differential load during rolling is separated into the one caused by the meandering of the rolled material and the one caused by the thrust, and the driving is performed based on these separated differential loads. A method of controlling a rolling mill that operates the rolling position on the side and the operating side is disclosed.
Prior art literature
Patent documents
[0005]
Patent Document 1:
Japanese Patent Application Laid-Open No. 3499107 Patent Document 2: Japanese Patent Application Laid-Open No. 2014-4599
Patent Document 3: Japanese Patent Application Laid-Open No. 8-294713
Patent Document 4: Japanese Patent Application Laid-Open No. 4962334
Outline of the invention
Problems to be solved by the invention
[0006]
　However, in the technique described in Patent Document 1, it is necessary to measure the thrust reaction force of a roll other than the reinforcing roll at the time of zero adjustment of the rolling position and during rolling, but when measuring the thrust reaction force during rolling, rolling. Depending on the change in rolling conditions such as load, the characteristics such as the point of action of the thrust reaction force may change, and the asymmetric deformation due to the thrust force may not be correctly specified. Therefore, it may not be possible to accurately perform the reduction leveling control.
[0007]
　Further, in the technique described in Patent Document 2, the roll skew angle is obtained from the horizontal distance of the roll measured by a distance sensor such as a vortex flow type. However, the roll vibrates in the horizontal direction due to machining accuracy such as eccentricity or cylindricity of the roll body length part, and the chock position in the horizontal direction fluctuates due to the impact at the time of biting at the start of rolling. It is difficult to accurately measure the horizontal displacement of the roll due to. Further, the coefficient of friction of the roll changes from moment to moment because the roughness of the roll changes with time as the number of rolled rolls increases. Therefore, it is not possible to accurately calculate the thrust force only from the roll skew angle measurement without identifying the friction coefficient.
[0008]
　Further, in the technique described in Patent Document 3, the cross angle between rolls is caused by the relative cross between rolls, and the roll bearing or the like also has play. Therefore, each roll chock position is individually controlled in the rolling direction. However, the relative positional relationship of the roll itself is not eliminated. Therefore, the thrust force generated by the cross angle between rolls cannot be eliminated.
[0009]
　Further, in the technique described in Patent Document 4, prior to rolling, a bending force is applied while driving the rolls in a state where the upper and lower rolls do not contact each other, and the bending force is obtained from the load difference between the driving side and the working side generated at that time. The differential load due to thrust is estimated from the thrust coefficient or skew amount. In Patent Document 4, the thrust coefficient or the skew amount is identified only from the measured value in one rotation state of the upper and lower rolls. Therefore, if the zero point of the load detector is displaced or the influence of the frictional resistance between the housing and the roll chock is different on the left and right, a left-right asymmetric error may occur between the measured value on the driving side and the measured value on the working side. is there. In particular, when the load level is small, such as bending force, such an error can be a fatal error in identifying the thrust coefficient or skew amount.
[0010]
　Further, in Patent Document 4, the thrust coefficient or the skew amount cannot be identified unless the friction coefficient between rolls is given. Further, in Patent Document 4, the thrust reaction force of the backup roll acts on the position of the roll axis, and the change in the position of the action point of the thrust reaction force is not considered. Normally, the chock of the backup roll is supported by a reduction device or the like, so the position of the point of action of the thrust reaction force is not always located at the center of the roll axis. For this reason, an error occurs in the thrust force between rolls obtained from the load difference between the downward load on the drive side and the downward load on the work side, and the thrust coefficient or skew amount calculated based on the thrust force between rolls also has an error. Occurs. When an error occurs in the thrust coefficient or the skew amount in this way, the accuracy of meandering control of the material to be rolled is lowered due to the influence of the error.
[0011]
　Further, as a normal preparatory work before rolling, after the work roll is rearranged, the zero point of the rolling position in the kiss roll state is adjusted by the operator based on the values ​​of the rolling load on the working side and the driving side. At this time, if an inter-roll thrust force is generated by the inter-roll minute cloth, the load in the reduction direction differs between the work side and the drive side, and the reduction position zero point adjustment may not be performed correctly. However, with the techniques described in any of the patent documents shown above, it is not possible to reduce the inter-roll thrust force before adjusting the reduction position zero point.
[0012]
　Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the thrust force generated between the rolls before the adjustment of the zero point of the rolling position or before the start of rolling. It is an object of the present invention to provide a new and improved rolling mill and a method for setting a rolling mill capable of suppressing the occurrence of meandering and camber of a material to be rolled.
Means to solve problems
[0013]
　In order to solve the above problems, according to a certain viewpoint of the present invention, a rolling mill having four or more stages including a plurality of rolls including at least a pair of working rolls and a pair of reinforcing rolls supporting the working rolls. , Using any one of the rolls arranged in the rolling direction as a reference roll, load detection for detecting the rolling rolling load acting in the rolling direction at the rolling fulcrum positions on the working side and the driving side of the reinforcing roll. An apparatus and a pressing device provided on either the entry side or the exit side in the rolling direction of the material to be rolled to press the roll chock in the rolling direction with respect to the roll chock of a roll other than the reference roll, and at least a roll other than the reference roll. A drive device that is provided so as to face the pressing device in the rolling direction and moves the roll chock in the rolling direction, and a load detection device on the working side that fixes the rolling direction position of the roll chock of the reference roll as a reference position. Drive the drive device so that the difference in rolling load, which is the difference between the rolling load detected by and the rolling load detected by the load detection device on the drive side, is within the permissible range. Provided is a rolling mill comprising a position control device for controlling the position of a roll chock of a roll other than the roll in the rolling direction.
[0014]
　Of the plurality of rolls, the roll located at the bottom or the top in the rolling direction may be used as the reference roll.
[0015]
　Further, a bending device that applies a bending force to the roll may be provided. At this time, the position control device opens the roll gap between the work rolls, and applies a bending force to the work roll chock on the roll side to be adjusted by the bending device.
[0016]
　The drive device may be a hydraulic cylinder provided with a roll chock position detection device.
[0017]
　Further, in order to solve the above problem, according to another viewpoint of the present invention, in the method of setting the rolling mill, the rolling mill has at least a pair of working rolls and a pair of reinforcing rolls supporting the working rolls. It is a rolling mill having four or more stages, including a plurality of rolls including, and a load detecting device for detecting a rolling load acting in the rolling direction at the rolling fulcrum positions on the working side and the driving side of the reinforcing roll. The rolling load detected by the load detection device on the working side and the load on the driving side are detected using any one of the rolls arranged in the rolling direction as a reference roll, which is carried out before adjusting the zero point or before the start of rolling. The reduction direction load difference, which is the difference from the reduction direction load detected by the device, is calculated, and the rolling direction position of the roll chock of the reference roll is fixed as the reference position so that the reduction direction load difference is within the allowable range. Further, a method for setting a rolling mill is provided, in which the position of the roll chock is adjusted by moving the roll chock of a roll other than the reference roll in the rolling direction of the material to be rolled.
[0018]
　Of the plurality of rolls, the roll located at the bottom or the top in the rolling direction may be used as the reference roll.
[0019]
　In a four-stage rolling mill, a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are used as an upper roll system, and a plurality of rolls provided on the lower side in the rolling direction with respect to the material to be rolled are used as a lower roll system. With the roll gap of the work roll open and the bending force applied to the roll chock of the work roll by the bending device, the roll chock of the work roll and the roll chock of the reinforcing roll are used for each of the upper roll system and the lower roll system. A first step of adjusting the position and a second step of adjusting the positions of the roll chocks of the upper roll system and the lower roll system by putting the work roll in the kiss roll state after completing the first step are carried out. In the first step, the roll is rotated in a predetermined rotation direction, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction load on the work side and the drive side are detected. The first reference value calculation step for calculating the first reference value based on the reduction load difference, which is the difference from the reduction load, and the rotation direction of the roll are reversed for each of the upper roll system and the lower roll system. , The reduction direction load on the work side and the drive side is detected, and the first is based on the deviation between the reduction direction load difference and the first reference value, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side. The roll chock of the work roll of the roll system on the reference roll side so that the first control target value calculation step for calculating the control target value and the reduction load difference are within the allowable range of the first control target value. Alternatively, the first adjustment step of moving the roll chock of either the work roll or the reinforcing roll of the roll system opposite to the reference roll in the rolling direction to adjust the position of the roll chock is carried out, and the second adjustment step is performed. In the step, the work roll is put into a kiss roll state, the roll is rotated in a predetermined rotation direction, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction direction on the work side is detected. The second reference value calculation step, which calculates the second reference value based on the reduction load difference, which is the difference between the load and the reduction load on the drive side, and the roll rotation direction are reversed to move up.For each of the roll system and the lower roll system, the reduction direction load on the work side and the drive side is detected, and the reduction direction load difference, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side, and the second reference value. The upper roll system or the upper roll system so that the load difference in the reduction direction is within the permissible range of the second control target value and the second control target value calculation step for calculating the second control target value based on the deviation from and. A second roll system in which one of the lower roll systems is used as a reference roll system and the roll chocks of each roll of the other roll system are controlled simultaneously and in the same direction while maintaining the relative positions between the roll chocks to adjust the position of the roll chocks. Adjustment steps and may be performed.
[0020]
　Further, in a 6-stage rolling mill having intermediate rolls between the working roll and the reinforcing roll, a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are applied to the upper roll system and the material to be rolled. With a plurality of rolls provided on the lower side in the rolling direction as the lower roll system, the roll gap of the working roll is opened, and the bending force is applied to the roll chock of the intermediate roll by the bending device, the upper roll system and the lower roll system are used. For each roll system, the first step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the reinforcing roll, and after the first step, the roll gap of the work roll is maintained in an open state, and the work roll The second step and the second step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the work roll for each of the upper roll system and the lower roll system while the bending force is applied to the roll chock of the above roll by the bending device. After completing the steps, the work roll is put into a kiss roll state, and the third step of adjusting the positions of the roll chocks of the upper roll system and the lower roll system is carried out, and in the first step, the rolls are rolled in a predetermined rotation direction. Is rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction load difference, which is the difference between the reduction load on the work side and the reduction load on the drive side. The first reference value calculation step for calculating the first reference value based on the above, and the rotation direction of the roll are reversed to detect the reduction load on the working side and the driving side for each of the upper roll system and the lower roll system. The first control target value calculation that calculates the first control target value based on the deviation between the reduction direction load difference, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side, and the first reference value. The roll chock of the intermediate roll of the roll system on the reference roll side and the intermediate roll of the roll system on the opposite side of the reference roll so that the load difference between the step and the reduction direction is within the allowable range of the first control target value. Move either the roll chock or the roll chock of the reinforcing roll in the rolling direction to adjust the position of the roll chock.The first adjustment step is performed, and in the second step, the roll is rotated in a predetermined rotation direction, and the reduction load on the working side and the driving side is detected for each of the upper roll system and the lower roll system. , The second reference value calculation step that calculates the second reference value based on the reduction load difference, which is the difference between the reduction load on the work side and the reduction load on the drive side, and the rotation direction of the roll are reversed. For each of the upper roll system and the lower roll system, the reduction direction load on the work side and the drive side is detected, and the reduction direction load difference, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side, and the second reduction direction load. The second control target value calculation step for calculating the second control target value based on the deviation from the reference value, and the reference roll so that the reduction load difference is within the allowable range of the second control target value. Adjust the position of the roll chock by moving either the roll chock of the work roll of the side roll system and the roll chock of the work roll of the roll system opposite to the reference roll or the roll chock of the intermediate roll and the reinforcing roll in the rolling direction. The second adjustment step and the second adjustment step are carried out, and in the third step, the work roll is put into a kiss roll state, the roll is rotated in a predetermined rotation direction, and the work side and the lower roll system are respectively driven. A third reference value calculation step that detects the reduction load on the side and calculates a third reference value based on the reduction load difference, which is the difference between the reduction load on the work side and the reduction load on the drive side. By reversing the rotation direction of the roll, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and it is the difference between the reduction load on the work side and the reduction load on the drive side. The third control target value calculation step for calculating the third control target value based on the deviation between the reduction direction load difference and the third reference value, and the reduction direction load difference are within the allowable range of the third control target value. The roll chocks of each roll of the other roll system are controlled simultaneously and in the same direction while maintaining the relative positions between the roll chocks, with one of the upper roll system and the lower roll system as the reference roll system so as to be a value. , A third adjustment to adjust the position of the roll chockYou may carry out with Tep.
[0021]
　Alternatively, in a four-stage rolling mill, a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are rolled up, and a plurality of rolls provided on the lower side in the rolling direction with respect to the material to be rolled are rolled down. As a system, the roll gap of the work roll is opened, and the bending force is applied to the roll chock of the work roll by the bending device. The first step of adjusting the position of the and, and the second step of adjusting the positions of the roll chocks of the upper roll system and the lower roll system by putting the work roll in the kiss roll state after completing the first step. In the first step, with the rotation of the roll stopped, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction load and the drive on the work side are detected. With the first control target value calculation step of calculating the first reference value based on the reduction direction load difference which is the difference from the side reduction direction load and setting the first control target value based on the first reference value. , The roll is rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction direction is the difference between the reduction load on the work side and the reduction load on the drive side. The roll chock or reference of the work roll of the roll system on the reference roll side so that the first load difference step for calculating the load difference and the reduction load difference are within the allowable range of the first control target value. The first adjustment step of moving the roll chock of the roll system work roll or the reinforcing roll on the opposite side of the roll in the rolling direction to adjust the position of the roll chock is carried out, and in the second step, the work roll is kissed and rolled. In this state, with the rotation of the roll stopped, the downward load on the work side and the reduction direction on the drive side are detected for each of the upper roll system and the lower roll system, and the reduction direction load on the work side and the reduction direction load on the drive side are detected. The second control target value calculation step for calculating the second reference value based on the reduction load difference, which is the difference between the two, and setting the second control target value based on the second reference value, and the roll.Is rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction load difference, which is the difference between the reduction load on the work side and the reduction load on the drive side. With the upper roll system or the lower roll system as the reference roll system, one of the upper roll system and the lower roll system is used as a reference roll system so that the second load difference calculation step for calculating A second adjustment step of adjusting the position of the roll chock may be performed by controlling the roll chock of each roll of the other roll system at the same time and in the same direction while maintaining the relative position between the roll chocks.
[0022]
　Further, in a 6-stage rolling mill having intermediate rolls between the working roll and the reinforcing roll, a plurality of rolls provided on the upper side in the reduction direction with respect to the material to be rolled are applied to the upper roll system and the material to be rolled. With a plurality of rolls provided on the lower side in the rolling direction as the lower roll system, the roll gap of the working roll is opened, and the bending force is applied to the roll chock of the intermediate roll by the bending device, the upper roll system and the lower roll system are used. For each of the roll systems, the first step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the reinforcing roll, and after completing the first step, the roll gap of the working roll is maintained in an open state, and the working roll The second step and the second step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the work roll for each of the upper roll system and the lower roll system with the bending force applied to the roll chock of the above. After completing the steps, the work roll is put into the kiss roll state, and the third step of adjusting the positions of the roll chocks of the upper roll system and the lower roll system is carried out, and in the first step, the rotation of the roll is stopped. In this state, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the difference in the reduction load, which is the difference between the reduction load on the work side and the reduction load on the drive side, is calculated. Based on the first control target value calculation step in which the first reference value is calculated and the first control target value is set based on the first reference value, and the roll is rotated to rotate the upper roll system and the lower roll system, respectively. The first load difference calculation step, which detects the reduction load on the work side and the drive side and calculates the reduction load difference between the reduction load on the work side and the reduction load on the drive side, and the reduction The roll chock of the intermediate roll of the roll system on the reference roll side and the roll chock or reinforcement of the intermediate roll of the roll system on the opposite side of the reference roll so that the directional load difference is within the allowable range of the first control target value. Perform the first adjustment step of moving any of the rolls in the rolling direction to adjust the position of the roll chock.In the second step, with the rotation of the roll stopped, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction load on the work side and the reduction load on the drive side are detected. The second control target value calculation step of calculating the second reference value based on the reduction direction load difference from the reduction direction load and setting the second control target value based on the second reference value, and rotating the roll. For each of the upper roll system and the lower roll system, the reduction direction load on the work side and the drive side is detected, and the reduction direction load difference, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side, is calculated. The roll chock of the work roll of the roll system on the reference roll side and the side opposite to the reference roll so that the second load difference calculation step and the reduction load difference are within the allowable range of the second control target value. A second adjustment step of moving either the roll chock of the work roll or the roll chock of the intermediate roll and the reinforcing roll in the rolling direction to adjust the position of the roll chock is carried out, and in the third step, With the work roll in the kiss roll state and the rotation of the roll stopped, the reduction load on the work side and the drive side are detected for each of the upper roll system and the lower roll system, and the reduction load on the work side and the drive side are detected. A third control target value calculation step for calculating a third reference value from the reduction direction load difference, which is the difference from the reduction direction load, and setting a third control target value based on the third reference value, and a roll. Is rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction load difference, which is the difference between the reduction load on the work side and the reduction load on the drive side. With the upper roll system or the lower roll system as the reference roll system, one of the upper roll system and the lower roll system is used as the reference roll system so that the third load difference calculation step for calculating A third adjustment step of adjusting the position of the roll chock may be performed by controlling the roll chock of each roll of the other roll system at the same time and in the same direction while maintaining the relative position between the roll chocks.
The invention's effect
[0023]
　As described above, according to the present invention, it is possible to reduce the thrust force generated between the rolls before the reduction position zero adjustment or the start of rolling, and to suppress the meandering and camber of the material to be rolled. It becomes.
A brief description of the drawing
[0024]
FIG. 1 is a schematic side view and a schematic front view of the rolling mill for explaining the thrust force and the thrust reaction force generated between the rolls of the rolling mill during rolling.
FIG. 2 is an explanatory diagram showing a configuration of a rolling mill according to the first embodiment of the present invention and an apparatus for controlling the rolling mill.
FIG. 3A is a flowchart illustrating a method of setting a rolling mill that adjusts the roll chock position based on a rolling load in the rolling direction and a roll reversing according to the same embodiment, wherein the first roll gap is open. Explains the adjustment.
[Fig. 3B] Fig. 3B is a flowchart illustrating a setting method of a rolling mill that adjusts the roll chock position based on the rolling load in the rolling direction and the roll reversing according to the same embodiment, wherein the second adjustment in the kiss roll state is performed. Explaining.
[Fig. 4A] Fig. 4A is an explanatory diagram showing a procedure for adjusting the roll chock position in the method of setting the rolling mill according to the same embodiment, showing the position adjustment in the roll gap open state.
FIG. 4B is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the same embodiment, showing the position adjustment in the kiss-roll state.
FIG. 5 is a schematic side view and a schematic front view showing an example of the driving state of the rolling mill state when the cross angle between rolls is identified.
FIG. 6 is an explanatory view showing the difference in rolling load obtained in the rolling mill in the state of FIG. 5 between the case where the lower roll is rotated forward and the case where the lower roll is reversed.
FIG. 7A is a flowchart illustrating a method of setting a rolling mill that adjusts a roll chock position based on a rolling load during roll stop and roll rotation according to a second embodiment of the present invention, in a roll gap open state. The first adjustment in is explained.
FIG. 7B is a flowchart for explaining a setting method of a rolling mill that adjusts the roll chock position based on the rolling load when the roll is stopped and when the roll is rotated according to the same embodiment, and describes the second adjustment in the kiss roll state. doing.
FIG. 8A is an explanatory diagram showing a procedure for adjusting the roll chock position in the method of setting the rolling mill according to the same embodiment, showing the position adjustment in the roll gap open state.
FIG. 8B is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the same embodiment, showing the position adjustment in the kiss-roll state.
FIG. 9 is a schematic side view and a schematic front view showing another example of the driving state of the rolling mill state when the cross angle between rolls is identified.
FIG. 10 is an explanatory diagram showing a difference in rolling load obtained in the rolling mill in the state of FIG. 9 when the lower roll is stopped and when the lower roll is rotated.
FIG. 11 is an explanatory view showing the arrangement of working rolls and reinforcing rolls of a rolling mill in which the roll gap is open.
FIG. 12 is an explanatory diagram showing a definition of a cross angle between rolls.
FIG. 13 is a graph showing one relationship between the reinforcing roll cross angle and the reduction load difference in the roll gap open state shown in FIG.
FIG. 14 is an explanatory view showing the arrangement of the working rolls and the reinforcing rolls of the rolling mill in the kiss roll state, and shows the state with the pair cloth.
15 is a graph showing one relationship between the reinforcing roll cross angle in the kiss roll state shown in FIG. 14 and the load difference in the reduction direction.
FIG. 16 is an explanatory diagram showing an example in which a servomotor with a rotation angle detection function is applied instead of a hydraulic cylinder provided with a roll chock position detection device.
FIG. 17A is an explanatory diagram showing a procedure (first adjustment) for adjusting the roll chock position when the setting method of the rolling mill shown in FIG. 4A or FIG. 8A is applied to the 6-stage rolling mill.
FIG. 17B is an explanatory diagram showing a procedure (second adjustment) of roll chock position adjustment when the setting method according to the present embodiment is applied to a 6-stage rolling mill.
FIG. 17C is an explanatory diagram showing a procedure (third adjustment) of roll chock position adjustment when the setting method of the rolling mill shown in FIG. 4B or FIG. 8B is applied to a 6-stage rolling mill.
Mode for carrying out the invention
[0025]
　Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.
[0026]
　<1. Objective> In the
　method of setting the rolling mill according to the embodiment of the present invention and the rolling mill of the rolling mill, the thrust force generated between the rolls is eliminated, and a product without meandering and camber or with extremely slight meandering and camber is stabilized. The purpose is to manufacture. FIG. 1 shows a schematic side view and a schematic front view of the rolling mill for explaining the thrust force and the thrust reaction force generated between the rolls of the rolling mill when the material S to be rolled is rolled. In the following, as shown in FIG. 1, the working side in the roll body length direction is referred to as WS (Work Side), and the driving side is referred to as DS (Drive Side).
[0027]
　The rolling mill shown in FIG. 1 has a pair of working rolls including an upper working roll 1 and a lower working roll 2, and an upper reinforcing roll 3 and a lower working roll 2 that support the upper working roll 1 in the rolling direction (Z direction). It has a pair of reinforcing rolls including a supporting lower reinforcing roll 4. By passing the material S to be rolled between the work rolls and rolling, the plate thickness of the material S to be rolled is made a predetermined thickness. In the rolling mill, in the rolling direction (Z direction), the rolling down load for detecting the rolling down load related to the upper roll system composed of the upper working roll 1 and the upper reinforcing roll 3 arranged on the upper surface side of the material S to be rolled. The detection devices 28a and 28b, and the lower rolling downward load detecting devices 29a and 29b for detecting the lower rolling load related to the lower roll system including the lower working roll 2 and the lower reinforcing roll 4 arranged on the lower surface side of the material S to be rolled. Is provided. The upper pressure lower load detection device 28a and the lower pressure lower load detection device 29a detect the reduction load on the working side. The upper pressure lower load detection device 28b and the lower pressure lower load detection device 29b detect the reduction load on the drive side.
[0028]
　The upper work roll 1, the lower work roll 2, the upper reinforcing roll 3 and the lower reinforcing roll 4 are arranged so that the body length directions of the rolls are parallel to each other so as to be orthogonal to the conveying direction of the material S to be rolled. However, the roll rotates slightly around an axis (Z axis) parallel to the reduction direction, and the upper work roll 1 and the upper reinforcement roll 3 are displaced in the body length direction, or the lower work roll 2 and the lower reinforcement roll 4 When the displacement in the body length direction of the roll occurs, a thrust force acting in the body length direction of the roll is generated between the work roll and the reinforcing roll. The inter-roll thrust force causes a moment in the roll, which is one of the causes of unstable rolling due to asymmetric roll deformation, and causes, for example, meandering or camber. This inter-roll thrust force is generated when the work roll and the reinforcing roll are displaced in the roll body length direction and a cross angle between the rolls is generated. For example, if a cross angle between rolls is generated between the lower work roll 2 and the lower reinforcing roll 4, a thrust force is generated between the lower work roll 2 and the lower reinforcing roll 4, and as a result, the lower reinforcing roll 4 is generated. A moment is generated in the roll 4, and the load distribution between the rolls changes so as to be balanced with this moment, resulting in asymmetric roll deformation. Rolling becomes unstable due to meandering or camber caused by such asymmetrical roll deformation.
[0029]
　Therefore, in the present invention, in rolling of the material to be rolled by the rolling mill, by adjusting the roll chock position of each roll so that the thrust force between the rolls generated is eliminated, there is no meandering and camber, or meandering and camber The purpose is to stably manufacture extremely light products. In particular, the present invention proposes a method of adjusting the roll chock position of each roll so that the inter-roll thrust force generated between the rolls is eliminated even when the thrust reaction force applied to the rolls cannot be measured.
[0030]
　<2. First Embodiment>
　Based on FIGS. 2 to 4B, the configuration of the rolling mill according to the first embodiment of the present invention, the apparatus for controlling the rolling mill, and the setting method of the rolling mill will be described. In the first embodiment, before the reduction position zero adjustment or before the start of rolling, the cross angle between the rolls of the reference reinforcing roll and the other roll is adjusted to be zero, and rolling without thrust force is realized. Is what you do. The rolling mill according to the present embodiment is not provided with a thrust reaction force measuring device for measuring the thrust reaction force, and the cross between rolls can be adjusted even when the thrust reaction force applied to the rolls cannot be measured. is there.
[0031]
　[2-1. Configuration of Rolling Machine]
　First, a rolling machine according to the present embodiment and an apparatus for controlling the rolling machine will be described with reference to FIG. FIG. 2 is an explanatory diagram showing a configuration of a rolling mill according to the present embodiment and an apparatus for controlling the rolling mill. It is assumed that the rolling mill shown in FIG. 2 shows a state seen from the working side in the roll body length direction, and the rolling direction is from the left to the right of the paper surface. Further, FIG. 2 shows a configuration when the lower reinforcing roll is used as a reference roll. In the invention according to the present embodiment, any one of the rolls arranged in the rolling direction may be set as the reference roll. The reference roll is preferably a roll located at the bottom or top where the contact area between the chock and the housing is large and the position is stable.
[0032]
　The rolling mill shown in FIG. 2 is a four-stage rolling mill having a pair of working rolls 1 and 2 and a pair of reinforcing rolls 3 and 4 supporting the rolling mills 1 and 2. In the four-stage rolling mill, the upper working roll 1, the lower working roll 2, the upper reinforcing roll 3 and the lower reinforcing roll 4 are a plurality of rolls arranged in the rolling direction. The upper work roll 1 is supported by the upper work roll chock 5, and the lower work roll 2 is supported by the lower work roll chock 6. The upper work roll chock 5 and the lower work roll chock 6 are also provided on the back side (drive side) of FIG. 2 in the same manner, and support the upper work roll 1 and the lower work roll 2, respectively. The upper work roll 1 and the lower work roll 2 are rotationally driven by the drive electric motor 21. Further, the upper reinforcing roll 3 is supported by the upper reinforcing roll chock 7, and the lower reinforcing roll 4 is supported by the lower reinforcing roll chock 8. The upper reinforcing roll chock 7 and the lower reinforcing roll chock 8 are similarly provided on the back side (driving side) of FIG. 2, and support the upper reinforcing roll 3 and the lower reinforcing roll 4, respectively. The upper work roll chock 5, the lower work roll chock 6, the upper reinforcing roll chock 7, and the lower reinforcing roll chock 8 are held by the housing 30. The upper work roll chock 5, the lower work roll chock 6, the upper reinforcing roll chock 7, and the lower reinforcing roll chock 8 may be simply referred to as roll chocks.
[0033]
　The upper work roll chock 5 is provided on the rolling direction entry side and is provided on the upper work roll chock pressing device 9 for pressing the upper work roll chock 5 in the rolling direction, and is provided on the rolling direction exit side to detect the position in the rolling direction and move up. An upper working roll chock position detecting function driving device 11 for driving the working roll chock 5 in the rolling direction is provided.
[0034]
　Similarly, the lower work roll chock 6 is provided on the lower work roll chock pressing device 10 provided on the rolling direction entry side and presses the lower work roll chock 6 in the rolling direction, and is provided on the rolling direction exit side to detect the position in the rolling direction. A drive device 12 with a lower work roll chock position detection function that drives the lower work roll chock 6 in the rolling direction is provided. For example, a hydraulic cylinder is used for the drive device 11 with the upper work roll chock position detection function, the drive device 12 with the lower work roll chock position detection function, the drive mechanism of the upper work roll chock pressing device 9, and the drive mechanism of the lower work roll chock pressing device 10. Be done. In FIG. 2, the upper and lower work roll chock position detection function drive devices 11 and 12 and the upper and lower work roll chock pressing devices 9 and 10 display only the work side, but on the back side (drive side) of the paper surface. Is also provided in the same way.
[0035]
　The upper reinforcing roll chock 7 is provided on the outer side of the rolling direction and presses the upper reinforcing roll chock 7 in the rolling direction. An upper reinforcing roll chock position detecting function driving device 14 for driving the reinforcing roll chock 7 in the rolling direction is provided. For example, a hydraulic cylinder is used as the drive mechanism of the drive device 14 with the upper reinforcement roll chock position detection function and the upper reinforcement roll chock pressing device 13. In FIG. 2, the drive device 14 with the upper reinforcement roll chock position detection function and the upper reinforcement roll chock pressing device 13 display only the work side, but are also provided on the back side (drive side) of the paper surface. ..
[0036]
　On the other hand, the lower reinforcing roll chock 8 is a reference reinforcing roll chock because the lower reinforcing roll 4 is used as a reference roll in the present embodiment. Therefore, since the lower reinforcing roll chock 8 is not driven to adjust the position, it is not always necessary to have a driving device and a position detecting device like the upper reinforcing roll chock 7. However, in order to prevent the position of the reference reinforcing roll chock used as the reference for position adjustment from changing, for example, a lower reinforcing roll chock pressing device 40 or the like is provided on the entry side or the exit side in the rolling direction to suppress the rattling of the lower reinforcing roll chock 8. You may. In FIG. 2, the lower reinforcing roll chock pressing device 40 displays only the working side, but is also provided on the back side (driving side) of the paper surface.
[0037]
　The upper work roll chock pressing device 9, the lower working roll chock pressing device 10, the upper reinforcing roll chock pressing device 13, and the lower reinforcing roll chock pressing device 40 are provided on either the entry side or the exit side in the rolling direction of the material to be rolled, and roll chock. It is a pressing device that presses in the rolling direction, and is sometimes simply called a pressing device. The pressing device may be provided for at least a roll chock of a roll other than the reference roll. Further, the upper work roll chock position detection function drive device 11, the lower work roll chock position detection function drive device 12, and the upper reinforcement roll chock position detection function drive device 14 are provided so as to face the pressing device in the rolling direction. Is a driving device that moves in the rolling direction, and is sometimes simply called a driving device. The drive device may also be provided for at least a roll chock of a roll other than the reference roll.
[0038]
　The rolling mill according to the present embodiment includes an inlet upper incremental bending device 24a and an outgoing upper incremental bending device 24b in a project block between the upper working roll chock 5 and the housing 30. Further, the rolling mill is provided with an inlet lower incremental bending device 25a and an outer lower incremental bending device 25b in the project block between the lower working roll chock 6 and the housing 30. The inlet upper ink lease bending device 24a, the exit side upper ink lease bending device 24b, the inlet lower ink lease bending device 25a, and the exit side lower ink lease bending device 25b are the same on the back side (drive side) of FIG. It is provided in. Each increase bending device applies an increase bending force for applying a load to the upper work roll 1 and the upper reinforcement roll 3, the lower work roll 2 and the lower reinforcement roll 4 to the work roll chock. The inlet upper ink lease bending device 24a, the exit side upper ink lease bending device 24b, the inlet lower ink lease bending device 25a, and the exit side lower ink lease bending device 25b are bending devices that apply a bending force to the roll. , Sometimes simply referred to as a bending device.
[0039]
　As devices for controlling the rolling mill, for example, as shown in FIG. 2, a roll chock rolling direction force control device 15, a roll chock position control device 16, a drive electric motor control device 22, and an inter-roll cross control device are used. 23 and an increase bending control device 26.
[0040]
　The roll chock rolling direction force control device 15 controls the pressing force in the rolling direction of the upper work roll chock pressing device 9, the lower working roll chock pressing device 10, the upper reinforcing roll chock pressing device 13, and the lower reinforcing roll chock pressing device 40. The roll chock rolling direction force control device 15 is based on the control instruction of the inter-roll cross control device 23, which will be described later, and is the upper work roll chock pressing device 9, the lower work roll chock pressing device 10, and the upper reinforcing roll chock pressing, which are the objects to be controlled at the chock position. By driving the device 13 and applying a predetermined pressing force, a state in which the chock position can be controlled is formed.
[0041]
　The roll chock position control device 16 controls the drive of the upper work roll chock position detection function drive device 11, the lower work roll chock position detection function drive device 12, and the upper reinforcement roll chock position detection function drive device 14. The roll chock position control device 16 is also simply referred to as a position control device. Based on the control instruction of the inter-roll cross control device 23, the roll chock position control device 16 makes the reduction direction load difference, which is the difference between the reduction direction load on the working side of the roll and the reduction direction load on the drive side, within a predetermined range. The drive device 11 with the upper work roll chock position detection function, the drive device 12 with the lower work roll chock position detection function, and the drive device 14 with the upper reinforcement roll chock position detection function are driven. The drive devices 11, 12, and 14 with a position detection function are arranged on both the work side and the drive side, and the same amount of the positions in the rolling direction on the work side and the drive side are reversed on the work side and the drive side. By controlling, only the roll cross angle can be changed without changing the average rolling direction positions on the working side and the driving side.
[0042]
　The drive electric motor control device 22 controls the drive electric motor 21 that rotationally drives the upper work roll 1 and the lower work roll 2. The drive motor control device 22 according to the present embodiment controls the drive of the upper work roll 1 or the lower work roll 2 based on the instruction from the inter-roll cross control device 23.
[0043]
　The inter-roll cross control device 23 is provided with respect to the upper work roll 1, the lower work roll 2, the upper reinforcing roll 3, and the lower reinforcing roll 4 constituting the rolling mill so that the cross angle between the rolls becomes zero. Control the position. The inter-roll cross control device 23 is a roll chock rolling direction force control device 15 and a roll chock so that the reduction direction load difference, which is the difference between the reduction direction load on the working side of the roll and the reduction direction load on the drive side, is within a predetermined range. A control instruction is given to the position control device 16 and the drive electric motor control device 22 so that the cross generated between the rolls disappears. The details of the setting method of the rolling mill will be described later.
[0044]
　The increase bending control device 26 is a device that controls an entry side upper increase bending device 24a, an exit side upper increase bending device 24b, an entry side lower increase bending device 25a, and an exit side lower increase bending device 25b. .. The increase bending control device 26 controls the increase bending device so as to apply the increase bending force to the working roll chock based on the instruction from the inter-roll cross control device 23. The oil lease bending control device 26 controls the oil lease bending device not only when the cross between rolls according to the present embodiment is adjusted, but also when, for example, crown control or shape control of the material to be rolled is performed. You may go.
[0045]
　Further, the rolling mill is provided with a rolling mill 27. The reduction device 27 is a device that is installed above the uppermost roll (upper reinforcement roll 3 in FIG. 2) and presses the roll downward. By reducing the rolls from above to below by the reduction device 27, the position of each roll in the reduction direction can be adjusted. For example, when the upper work roll 1 and the lower work roll 2 are put into a kiss roll state, their positions are adjusted by applying a predetermined load to the upper work roll 1 and the lower work roll 2 by the reduction device 27. ..
[0046]
　In the reduction direction, the upper reduction downward load detecting devices 28a and 28b and the reduction device 27 are provided at the reduction fulcrum position 30a between the upper reinforcement roll chock 7 and the housing 30, and between the lower reinforcement roll chock 8 and the housing 30. At the reduction fulcrum position 30b, reduction reduction downward load detecting devices 29a and 29b are provided. Although only the upward / downward load detecting device 28a and the downward downward load detecting device 29a on the working side are shown in FIG. 2, as shown in FIG. 1, on the driving side on the back side of the paper in FIG. Is provided with an upper pressure downward load detecting device 28b and a lower pressure downward load detecting device 29b. The upper and lower pressure downward load detection devices 28a and 28b and the lower pressure lower load detection devices 29a and 29b are devices that are arranged at the lower pressure fulcrum positions of the upper and lower reinforcing roll chocks and detect the lower pressure downward load acting in the lower pressure direction. The load detection devices 28a and 28b detect the reduction load related to the uppermost roll, and the lower reduction load detection devices 29a and 29b detect the reduction load related to the lowermost roll.
[0047]
　The upper-downward load difference calculation unit 32 calculates the down-down load difference, which is the difference between the down-down load on the working side and the down-down load on the drive side, which is detected by the up-down down load detecting devices 28a and 28b. The lower reduction downward load difference calculation unit 33 calculates the lower reduction load difference, which is the difference between the lower reduction load on the working side and the lower reduction load on the drive side, which is detected by the lower reduction downward load detecting devices 29a and 29b. The reduction load difference calculated by the upper pressure lower load difference calculation unit 32 and the lower pressure lower load difference calculation unit 33 is output to the inter-roll cross control device 23. The inter-roll cross control device 23 recognizes the state of the inter-roll cross based on the input reduction load difference.
[0048]
　In the above example, for the working roll chocks 5 and 6, the drive devices 11 and 12 with a position detection function are on the outlet side of the rolling mill, the pressing devices 9 and 10 are on the inlet side, and the upper reinforcing roll chock 7 is of the rolling mill. Regarding the drive device 14 with a position detection function on the entry side, the pressing device 13 on the exit side, and the lower reinforcing roll chock 8, an example in which the pressing device 40 is provided on the exit side of the rolling mill has been described, but the present invention is limited to such an example. Not done. For example, these arrangements may be installed in reverse on the entry side and the exit side of the rolling mill, or may be installed in the same direction by the working roll and the reinforcing roll. Further, although the examples in which the drive devices 11, 12, and 14 with the position detection function are arranged on both the working side and the drive side and the positions are controlled respectively, the present invention is not limited to such an example. It is possible to control the roll cross angle by arranging these devices on only one side of the work side and the drive side, or by operating only one side and controlling the position with the other side as a fulcrum of rotation. Needless to say, the same effect of reducing the cross between rolls can be obtained. Further, FIG. 2 shows an example in which only the pressing device 40 is provided on the lower reinforcing roll chock 8 of the lower reinforcing roll 4, which is a reference roll, but the present invention is not limited to this example, and the entry side of the lower reinforcing roll chock 8 is not limited to this. A drive device with a position detection function may be provided in the vehicle so as to be controllable by the roll chock position control device 16. As a result, when the right-angled relationship between the reference roll axis and the rolling direction is extremely deviated due to wear of the liner, for example, the roll chock position control device 16 drives the reference reinforcing roll chock to finely adjust the position of the reference roll. It will be possible. Further, by arranging the drive device with the position detection function on all rolls, the reference roll may be changed according to the situation, and control may be performed based on the changed reference roll.
[0049]
　[2-2. Setting method of rolling mill]
　Hereinafter, the setting method of the rolling mill according to the present embodiment will be described with reference to FIGS. 3A to 6. 3A and 3B are flowcharts illustrating a method of setting a rolling mill that adjusts the roll chock position based on the rolling load in the rolling direction and the rolling reversing according to the present embodiment. FIG. 4A is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the present embodiment, and shows the position adjustment in the roll gap open state. FIG. 4B is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the present embodiment, and shows the position adjustment in the kiss roll state. In FIGS. 4A and 4B, the description of the load distribution acting between the rolls is omitted. FIG. 5 is a schematic side view and a schematic front view showing an example of the driving state of the rolling mill state when the cross angle between rolls is identified. In FIG. 5, the load distribution also changes with the change in the direction of the thrust force between the lower working roll 2 and the lower reinforcing roll 4 when the rolls are forward and reverse, but this is a slight change. Is not specified. FIG. 6 is an explanatory view showing the difference in the rolling reduction load acquired between the case where the lower roll is rotated forward and the case where the lower roll is reversed in the rolling mill in the state of FIG. In this example, the lower reinforcing roll 4 is described as a reference roll, but the reference roll may be either the uppermost roll or the lowermost roll in the rolling direction, and the upper reinforcing roll 3 may be the reference roll. is there.
[0050]
　In the method of setting the rolling mill according to the present embodiment, the upper and lower load detecting devices 28a and 28b are used for the case where the roll gap between the upper work roll 1 and the lower work roll 2 is opened and the case where the roll gap is set to the kiss roll state. The reduction direction load difference is calculated from the detected reduction direction load between the drive side and the work side, and the reduction direction load difference from the reduction direction load between the drive side and the work side detected by the reduction reduction direction load detection devices 29a and 29b. Is calculated. Then, the position of the roll chock is adjusted based on the calculated load difference in the rolling direction, and the cross between the rolls of each roll of the rolling mill is set within a predetermined range. At this time, the rolling direction position of the roll chock of the reference roll is fixed as the reference position, and the position of the roll chock of the roll other than the reference roll in the rolling direction is moved to adjust the position of the roll chock. The details will be described below.
[0051]
(A) First adjustment: Position adjustment when the roll gap is open (S100 to S116) In
　the first adjustment where the position is adjusted when the roll gap is open, the upper work roll and the lower work roll are opened and the ink lease is performed. A bending force is applied to apply a load between the work roll and the reinforcing roll, and the upper and lower work roll chock positions are controlled so that the difference in the downward load generated by the thrust force between the rolls becomes a predetermined target value. .. First, as shown in FIG. 3A, the inter-roll cross control device 23 is in an open state with respect to the reduction device 27 so that the roll gap between the upper work roll 1 and the lower work roll 2 has a predetermined gap. The roll position in the rolling direction is adjusted (S100). The reduction device 27 applies a predetermined load to the rolls based on the instruction, and opens the roll gaps of the work rolls 1 and 2.
[0052]
　Further, the inter-roll cross control device 23 instructs the increase bending control device 26 to apply a predetermined increase bending force to the work roll chocks 5 and 6 by the increase bending devices 24a, 24b, 25a and 25b. (S102). The increase bending control device 26 controls each of the increase bending devices 24a, 24b, 25a, 25b based on the instruction, and applies a predetermined increase bending force to the working roll chocks 5 and 6. As a result, a predetermined load can be applied only between the upper and lower work rolls and the reinforcing roll without applying a load between the upper and lower work rolls. When the increase bending device has a balancer function for lifting the weight of the work roll, the order of steps S100 and S102 is reversed, that is, the upper and lower work rolls are subjected to the increase bending force. The gap may be adjusted.
[0053]
　Next, the inter-roll cross control device 23 instructs the drive electric motor control device 22 to drive the drive electric motor 21 to rotate the work roll at a predetermined rotation speed and a predetermined rotation direction (S104). The rotation speed and rotation direction, which are roll rotation conditions, are set in advance, and the drive electric motor control device 22 rotates the upper work roll 1 and the lower work roll 2 under the set roll rotation conditions. The rotation direction of each work roll 1 and 2 in step S104 is set to the normal rotation direction. When the work roll is rotated, the upward and downward load detecting devices 28a and 28b and the downward and downward load detecting devices 29a and 29b detect the downward load on the working side and the driving side, respectively, and the upward and downward load difference calculation unit 32 And, it is output to the lower pressure lower load difference calculation unit 33. Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. Calculate the difference. The calculated load difference in the rolling direction at the time of forward rotation of the roll is input to the cross control device 23 between rolls and is set to a reference value 1 (corresponding to the "first reference value" of the present invention) (S106).
[0054]
　When the reference value 1 is calculated, the rotation direction of the work roll is then reversed, and the process at the time of roll reversal is started. The inter-roll cross control device 23 drives the drive motor 21 by the drive motor control device 22 to rotate the work roll at a predetermined rotation speed and a predetermined rotation direction (S108). When the work roll is rotated, the down pressure downward load detection devices 28a and 28b and the down pressure down load detection devices 29a and 29b detect the down pressure downward load on the work side and the drive side, respectively, as in the case of normal rotation of the roll. It is output to the upper pressure lower load difference calculation unit 32 and the lower pressure lower load difference calculation unit 33. The rotation direction of each work roll 1 and 2 in step S108 is set to the reverse direction.
[0055]
　Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. The difference is calculated, and the calculated difference load at the time of roll reversal is output to the inter-roll cross control device 23. Then, the inter-roll cross control device 23 sets the first control target for each of the upper roll system and the lower roll system based on the deviation between the load difference in the reduction direction at the time of roll reversal and the reference value 1 calculated in step S106. Calculate the value (S110). The first control target value is preferably a value that is half the deviation from the reference value 1. In addition, due to the influence of sliding resistance between the roll chock and the housing, bearing backlash, etc., there may be a difference in the characteristics of the load difference in the rolling direction in the direction of action of the thrust force during forward rotation and reverse rotation. In this case, the first control target value may be set according to the degree of difference in the magnitude of the reduction load difference between the normal rotation and the reverse rotation based on the result identified in advance. That is, the first control target value may be a value other than half of the deviation from the reference value 1.
[0056]
　Even after the first control target value is calculated, the reduction load on the working side and the reduction load on the drive side at the time of roll reversal are measured for each of the upper roll system and the lower roll system, and the difference is the reduction. The directional load difference is calculated (S112). Then, the inter-roll cross control device 23 compares the reduction load difference at the time of roll reversal calculated in step S112 with the first control target value calculated in step S110, and confirms that they match. Whether or not it is determined (S114). In the determination in step S114, not only when the reduction load difference at the time of roll reversal and the first control target value completely match, but also at the first control target value of the reduction direction load difference at the time of roll reversal. It shall also include the case where the deviation from is within the permissible range. The permissible range is, for example, in advance in the actual hot rolling process, the meandering amount (mm) at the tail end or the actual camber value (mm / m) per 1 m at the tip end and the load difference in the rolling direction at the time of roll reversal. After converting the asymmetric deformation amount obtained by roll deformation analysis etc. into the rolling down leveling amount, the relationship with the deviation from the first control target value, that is, the relationship with the minute cross between rolls is obtained, and meandering, The camber may be set to be below the standard required for the product. When it is determined in step S114 that the reduction load difference at the time of roll reversal is not the first control target value or is not within the allowable range, the inter-roll cross control device 23 refers to the roll chock position control device 16. Then, it is instructed to adjust the position of the working roll chock of the roll system that does not satisfy the requirement of step S114 (S116). Then, when the position of the work roll chock is adjusted, the process from step S112 is executed again. At this time, the position of the upper reinforcing roll chock instead of the upper working roll chock may be controlled so that the differential load generated by the thrust force between the upper working roll and the reinforcing roll is reduced.
[0057]
　When it is determined in step S114 that the load difference in the rolling direction at the time of roll reversal matches the first control target value or is within the permissible range thereof, the inter-roll cross control device 23 is shown in FIG. 3B. Move to processing.
[0058]
(Calculation of Reference Value 1 and First Control Target Value)
　Here, the calculation of the reference value 1 and the first control target value will be described in detail based on FIG. 4A. First, as shown on the upper side of FIG. 4A, in the roll gap open state, the upper roll system composed of the upper working roll 1 and the upper reinforcing roll 3 and the lower roll system composed of the lower working roll 2 and the lower reinforcing roll 4 are used. , Each rolls forward. At this time, since the upper work roll 1 and the lower work roll 2 are separated from each other, each roll system is in an independent state. In this roll normal rotation state, the reduction direction load on the working side and the reduction direction load on the drive side of the upper roll system, and the reduction direction load on the work side and the reduction direction load on the drive side of the lower roll system are measured. Then, from these measured values, the reduction load difference, which is the difference between the reduction load on the working side and the reduction load on the drive side, is calculated for each of the upper roll system and the lower roll system (P11 in FIG. 4A, P11, P12). The reduction load difference of each roll system is calculated by the following equation (1).
[0059]
[Number 1]

[0060]
　Here, P df1 T is the difference between the measured values ​​of the load in the downward direction between the working side and the drive side of the upper roll system in the roll normal rotation state (upper reference value 1 T ), and P df1 B is the roll normal rotation state. This is the difference between the measured values ​​of the load in the rolling direction between the working side and the driving side of the lower roll system (lower reference value 1 B ). The reference value 1 in step S106 refers to the upper reference value 1 T and the lower reference value 1 B. Also, P W T is upper roll system of the working side of the rolling direction measured load, P in the roll forward state W B is the rolling direction measured load of the working side of the lower roll system in the roll forward state. Then, P D T is upper roll system drive side pressure direction load measurement, P in the roll forward state D B is the rolling direction measured load on the drive side of the lower roll system in the roll forward state.
[0061]
　Next, the first control target value is calculated from the measured values ​​on the working side and the driving side of the vertical load in the vertical reduction direction measured in the roll reversal state and the reference value 1 calculated by the above equation (1).
[0062]
　Here, in the calculation of the first control target value, the relationship of the reduction direction load difference, which is the difference between the reduction direction load between the working side and the drive side, between the forward rotation and the reverse rotation of the roll was investigated. In this study, for example, as shown in FIG. 5, in a rolling mill having a pair of working rolls 1 and 2 and a pair of reinforcing rolls 3 and 4 supporting them, the upper working roll 1 and the lower working roll 2 are used. The roll gap between the working rolls 1 and 2 was opened. The upper work roll 1 is supported by the upper work roll chock 5a on the work side and the upper work roll chock 5b on the drive side. Further, the lower work roll 2 is supported by a lower work roll chock 6a on the work side and a lower work roll chock 6b on the drive side. Further, the upper reinforcing roll 3 is supported by the upper reinforcing roll chock 7a on the working side and the upper reinforcing roll chock 7b on the driving side. Further, the lower reinforcing roll 4 is supported by a lower reinforcing roll chock 8a on the working side and a lower reinforcing roll chock 8b on the driving side. An increase bending force is applied to the upper work roll chock 5a and 5b and the lower work roll chock 6a and 6b by an increase bending device (not shown) in a state where the work rolls 1 and 2 are separated from each other.
[0063]
　As shown in FIG. 5, when each roll is rotated in a state where a cross angle between the rolls is generated between the lower work roll 2 and the lower reinforcement roll 4, the space between the lower work roll 2 and the lower reinforcement roll 4 is formed. A thrust force is generated in the lower reinforcing roll 4, and a moment is generated in the lower reinforcing roll 4. In such a state, in this verification, the downward load was detected in the case where the roll was rotated forward and the case where the roll was reversed. For example, as shown in FIG. 6, the lower working roll is rotated around an axis (Z axis) parallel to the rolling direction by a predetermined cross angle change section at the time of roll forward rotation and roll reverse rotation, respectively, and the cross angle between rolls is adjusted. The reduction load when changed was detected. FIG. 6 shows the roll forward rotation and the roll reverse rotation when the cross angle between the rolls of the lower work roll is changed by 0.1 ° so as to face the exit side of the drive side in a small rolling mill having a work roll diameter of 80 mm. This is a measurement result in which a change in the load difference in the rolling direction is detected. The increment bending force applied to each work roll chock was 0.5 tonf / chuck.
[0064]
　Looking at the detection results, the reduction load difference, which is the difference between the reduction load on the drive side and the reduction load on the work side, acquired during normal roll rotation, is negative compared to before the cross angle between rolls was changed. It increases in the direction of. On the other hand, the reduction load difference, which is the difference between the reduction load on the drive side and the reduction load on the work side, acquired at the time of roll reversal, becomes larger in the positive direction than before the cross angle between the rolls is changed. As described above, the magnitude of the load difference in the rolling direction is substantially the same between the forward rotation of the roll and the reverse rotation of the roll, but the directions are opposite.
[0065]
　Therefore, based on the above relationship, the difference in the downward load at which the thrust force between the upper and lower working rolls and the reinforcing roll becomes zero is 1/2 of the deviation from the reference in the roll reverse state with the roll forward rotation state as a reference. The control target value (first control target value) of. The first control target value can be expressed by the following equation (2).
[0066]
[Number 2]

[0067]
　Here, P ' DFT1 T the first control target value of the upper roll system, P ' DFT1 B is first control target value of the lower roll system. Also, P ' W T is upper roll system tasks lateral pressure downward measured load, P in the roll reversal state ' W B is a working side pressure downward load measurements of lower roll system in the roll reversal state. Then, P ' D T is the pressing direction measured load on the drive side of the upper roll system in roll reversal state, P ' D B is the pressing direction measured load on the drive side of the lower roll system in roll reversal state, P ' df T is the difference of the work side and drive side of the rolling direction measured load of the upper roll system in roll reversal state, P ' df B is the working side and the driving side of the rolling direction measured load of the lower roll system in the roll reversal state The difference. In this way, the first control target values ​​of the upper roll system and the lower roll system can be calculated.
[0068]
　Here, the equation (2) is defined assuming that the magnitude of the load difference in the rolling direction is substantially the same between the normal roll rotation and the reverse roll rotation, but the sliding resistance between the roll chock and the housing, bearing backlash, etc. Due to the influence of, there may be a difference in the characteristics of the load difference in the rolling direction in the acting direction of the thrust force at the time of normal rotation and reverse rotation. In this case, the first control target value may be set according to the degree of difference in the magnitude of the reduction load difference between the normal rotation and the reverse rotation based on the result identified in advance. That is, the first control target value may be a value other than half of the deviation from the reference value 1.
[0069]
　The drive of the roke chock position at the time of roll reversal is for roll chock of rolls other than the reference roll. That is, for the upper roll system, the position of the upper working roll chock may be controlled as shown in the center of FIG. 4A (P13), or the position of the upper reinforcing roll chock may be controlled as shown in the lower side of FIG. 4A. Good (P15). On the other hand, regarding the lower roll system, the lower reinforcing roll 4 does not move because it is a reference roll, and the positions of the lower working roll chock are controlled as shown in the center and the lower side of FIG. 4A (P14, P16).
[0070]
(B) Second adjustment: Position adjustment in the kiss
　roll state (S118 to S134) Returning to the explanation of the flowchart, when the position adjustment in the open state of the roll gap shown in FIG. 3A is completed, the inter-roll cross control device 23 is next. As shown in FIG. 3B, causes the reduction device 27 to adjust the roll position in the reduction direction so that the roll gap between the upper work roll 1 and the lower work roll 2 is in a predetermined kiss roll state (S118). .. The reduction device 27 applies a predetermined load to the rolls based on the instruction, and brings the working rolls 1 and 2 into contact with each other to bring them into a kiss roll state.
[0071]
　Next, the inter-roll cross control device 23 drives the drive motor 21 by the drive motor control device 22 to rotate the work roll at a predetermined rotation speed and a predetermined rotation direction (S120). As described above, the rotation speed and the rotation direction, which are the roll rotation conditions, are set in advance, and the drive electric motor control device 22 rotates the upper work roll 1 and the lower work roll 2 under the set roll rotation conditions. The rotation direction of each work roll 1 and 2 in step S120 is the normal rotation direction. When the work rolls 1 and 2 are rotated, the downward load detection devices 28a and 28b and the downward downward load detection devices 29a and 29b detect the downward load on the work side and the drive side, respectively, and the difference between the upward and downward loads. It is output to the calculation unit 32 and the lower pressure downward load difference calculation unit 33.
[0072]
　Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. Calculate the difference. The calculated load difference in the rolling direction at the time of normal rotation of the roll is input to the cross control device 23 between rolls and is set to a reference value 2 (corresponding to the "second reference value" of the present invention) (S122).
[0073]
　When the reference value 2 is calculated, the rotation direction of the work roll is then reversed, and the process at the time of roll reversal is started. The inter-roll cross control device 23 drives the drive motor 21 by the drive motor control device 22 to rotate the work roll at a predetermined rotation speed and a predetermined rotation direction (S124). When the work roll is rotated, the down pressure downward load detection devices 28a and 28b and the down pressure down load detection devices 29a and 29b detect the down pressure downward load on the work side and the drive side, respectively, as in the case of normal rotation of the roll. It is output to the upper pressure lower load difference calculation unit 32 and the lower pressure lower load difference calculation unit 33. The rotation direction of each of the work rolls 1 and 2 in step S124 is set to the reverse direction.
[0074]
　Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. The difference is calculated, and the calculated load difference in the rolling direction at the time of roll reversal is output to the inter-roll cross control device 23. Then, the inter-roll cross control device 23 sets a second control target for each of the upper roll system and the lower roll system based on the deviation between the reduction load difference at the time of roll reversal and the reference value 2 calculated in step S122. Calculate the value (S126). The second control target value is, for example, half the deviation of the reference value 2. In addition, due to the influence of sliding resistance between the roll chock and the housing, bearing backlash, etc., there may be a difference in the characteristics of the load difference in the rolling direction in the direction of action of the thrust force during forward rotation and reverse rotation. In this case, the second control target value may be set according to the degree of difference in the magnitude of the reduction load difference between the normal rotation and the reverse rotation based on the result identified in advance. That is, the second control target value may be a value other than half the deviation from the reference value 2.
[0075]
　Even after the second control target value is calculated, the reduction load on the working side and the reduction load on the drive side at the time of roll reversal are measured for each of the upper roll system and the lower roll system, and the difference is the reduction. The directional load difference is calculated (S128). Then, the inter-roll cross control device 23 compares the reduction load difference at the time of roll reversal calculated in step S128 with the second control target value calculated in step S126, and confirms that they match. Whether or not it is determined (S130). In the determination in step S130, not only when the reduction load difference at the time of roll reversal and the second control target value completely match, but also at the second control target value of the reduction direction load difference at the time of roll reversal. It shall also include the case where the deviation from is within the predetermined range. When it is determined in step S130 that the load difference in the rolling direction at the time of roll reversal is not the second control target value or is not within the allowable range, the inter-roll cross control device 23 refers to the roll chock position control device 16. Then, it is instructed to adjust the position of the work roll chock of the roll system that does not satisfy the requirement of step S130 (S132). Then, when the position of the work roll chock is adjusted, the process from step S128 is executed again.
[0076]
　When it is determined in step S130 that the load difference in the rolling direction at the time of roll reversal matches the second control target value or is within the permissible range thereof, the inter-roll cross control device 23 determines that the upper reinforcing roll 3 Assuming that the cross between the rolls of the upper work roll 1, the lower work roll 2 and the lower reinforcement roll 4 is adjusted within the permissible range, the roll gap between the upper work roll 1 and the lower work roll 2 is predetermined with respect to the reduction device 27. It is adjusted so as to have the size of (S134). After that, the reduction position zero point adjustment or the rolling of the material to be rolled by the rolling mill is started.
[0077]
(Calculation of Reference Value 2 and Second Control Target Value)
　Here, the calculation of the reference value 2 and the second control target value will be described in detail based on FIG. 4B. In the second adjustment, the tightening load is applied in the kiss roll state in which the upper and lower work rolls are in contact with each other, and the reduction load difference generated by the thrust force between the upper and lower work rolls in that state becomes a predetermined target value. Control the work roll and reinforcement roll chock positions on the opposite side of the reference roll.
[0078]
　First, as shown on the upper side of FIG. 4B, in the kiss roll state, the upper roll system composed of the upper work roll 1 and the upper reinforcement roll 3 and the lower roll system composed of the lower work roll 2 and the lower reinforcement roll 4, respectively. Rotate the roll forward. Then, the reduction direction load on the working side of the upper roll system and the reduction direction load on the drive side, and the reduction direction load on the work side of the lower roll system and the reduction direction load on the drive side are measured. From these measured values, the reduction load difference, which is the difference between the reduction load on the working side and the reduction load on the drive side, is calculated for each of the upper roll system and the lower roll system (P21, P22). The reduction load difference of each roll system is calculated by the following equation (3).
[0079]
[Number 3]

[0080]
　Here, P df2 T is the difference between the measured values ​​of the load in the downward direction between the working side and the driving side of the upper roll system in the roll normal rotation state in the kiss roll state (upper reference value 2 T ), and P df2 B is the kiss roll state. This is the difference (lower reference value 2 B ) between the working side and the driving side of the lower roll system in the roll normal rotation state in the rolling direction . Step reference value 2 of the S122, the upper reference value 2 T and the lower reference value 2 B points to.
[0081]
　Next, the rotation of the roll is reversed in the kiss roll state, and the second control is performed from the measured values ​​of the upper and lower reduction load on the working side and the driving side and the reference value 2 calculated by the above equation (3). Calculate the target value. Similar to the first control target value, the second control target value also has 1/2 of the deviation from the reference in the roll reverse state when the roll forward rotation state is used as a reference, between the upper and lower work rolls and the reinforcing roll. It can be set as a control target value (second control target value) of the difference in the downward load at which the thrust force of the is zero. That is, the second control target value can be expressed by the following equation (4).
[0082]
[Number 4]

[0083]
　Here, P ' dft2 T second control target value of the upper roll system, P ' dft2 B is the second target control value of the lower roll system. In this way, the second control target values ​​of the upper roll system and the lower roll system can be calculated. In the above calculation, a method of calculating the load in both the upper and lower reduction directions was shown, but in the second adjustment, it is generated by the thrust force between the upper and lower work rolls in the kiss roll state in which the upper and lower work rolls are in contact with each other. Since it is the difference in the load in the rolling direction, the effect of this cross between rolls appears on both the top and bottom as well. Therefore, in this case, the work roll and the reinforcing roll chock position on the side opposite to the reference roll may be controlled by using at least one of the upper and lower values ​​(P23 in FIG. 4B).
[0084]
　Here, the equation (4) is defined assuming that the magnitude of the load difference in the rolling direction is substantially the same between the normal roll rotation and the reverse roll rotation, but the sliding resistance between the roll chock and the housing, bearing backlash, etc. Due to the influence of, there may be a difference in the characteristics of the load difference in the rolling direction in the acting direction of the thrust force at the time of normal rotation and reverse rotation. In this case, the second control target value may be set according to the degree of difference in the magnitude of the reduction load difference between the normal rotation and the reverse rotation based on the result identified in advance. That is, the second control target value may be a value other than half the deviation from the reference value 2.
[0085]
　[2-3. Summary] The
　rolling mill according to the first embodiment of the present invention and the setting method of the rolling mill have been described above. According to the present embodiment, the magnitude of the load difference in the rolling direction is substantially the same between the forward rotation of the roll and the reverse rotation of the roll, but the directions are opposite to each other. The control target value for setting the angle to zero is calculated and set, and the first adjustment and the second adjustment are performed before the reduction position zero adjustment or before the start of rolling. As a result, the material to be rolled is rolled with the cross angle between the rolls eliminated, so that the meandering and camber of the material to be rolled can be suppressed.
[0086]
　<3. Second Embodiment>
　Next, a method of setting the rolling mill according to the second embodiment of the present invention will be described based on FIGS. 7A to 8B. Similar to the first embodiment, the present embodiment is adjusted so that the cross angle between the rolls of the reference reinforcing roll and the other rolls is zero before the rolling reduction position zero point is adjusted or before the start of rolling, and the thrust force is adjusted. This is to realize rolling that does not generate. Similar to the first embodiment, the rolling mill according to the present embodiment can also adjust the cross between rolls even when the thrust reaction force cannot be measured. The rolling mill according to the present embodiment and the apparatus for controlling the rolling mill can be configured in the same manner as the rolling mill according to the first embodiment shown in FIG. 2 and the control device thereof. Therefore, detailed description of these will be omitted in the present embodiment.
[0087]
　[3-1. Setting method of rolling mill]
　FIGS. 7A and 7B are flowcharts for explaining the setting method of the rolling mill according to the present embodiment, in which the position is adjusted based on the rolling load at the time of rolling stop and the time of rolling rotation. An example of is shown. FIG. 8A is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the present embodiment, and shows the position adjustment in the roll gap open state. FIG. 8B is an explanatory diagram showing a procedure for adjusting the roll chock position in the method for setting the rolling mill according to the present embodiment, and shows the position adjustment in the kiss roll state. In FIGS. 7A and 7B, the description of the load distribution acting between the rolls is omitted. Further, in this example, the lower reinforcing roll 4 is described as a reference roll, but the reference roll may be either the uppermost roll or the lowermost roll in the rolling direction, and the upper reinforcing roll 3 is the reference roll. In some cases.
[0088]
　In the method of setting the rolling mill according to the present embodiment, the upper and lower load detecting devices 28a and 28b are used for the case where the roll gap between the upper work roll 1 and the lower work roll 2 is opened and the case where the roll gap is set to the kiss roll state. The reduction direction load difference is calculated from the detected reduction direction load between the drive side and the work side, and the reduction direction load difference from the reduction direction load between the drive side and the work side detected by the reduction reduction direction load detection devices 29a and 29b. Is calculated. Then, the position of the roll chock is adjusted based on the calculated load difference in the rolling direction, and the cross between the rolls of each roll of the rolling mill is set within a predetermined range. At this time, the control target value for adjusting the position of the roll chock is derived using the reduction load on the working side and the driving side of the upper roll system and the lower roll system, which are measured when the roll is stopped and when the roll is rotated. To. At this time, the rolling direction position of the roll chock of the reference roll is fixed as the reference position, and the position of the roll chock of the roll other than the reference roll in the rolling direction is moved to adjust the position of the roll chock. The details will be described below.
[0089]
(A) First adjustment: Position adjustment when the roll gap is open (S200 to S214) In
　the first adjustment where the position is adjusted when the roll gap is open, the upper work roll and the lower work roll are opened and the ink lease is performed. A bending force is applied to apply a load between the work roll and the reinforcing roll, and the upper and lower work roll chock positions are controlled so that the difference in the downward load generated by the thrust force between the rolls becomes a predetermined target value. .. First, as shown in FIG. 7A, the inter-roll cross control device 23 is in an open state with respect to the reduction device 27 so that the roll gap between the upper work roll 1 and the lower work roll 2 has a predetermined gap. The roll position in the rolling direction is adjusted (S200). The reduction device 27 applies a predetermined load to the rolls based on the instruction, and opens the roll gaps of the work rolls 1 and 2.
[0090]
　Further, the inter-roll cross control device 23 instructs the increase bending control device 26 to apply a predetermined increase bending force to the work roll chocks 5 and 6 by the increase bending devices 24a, 24b, 25a and 25b. (S202). The increase bending control device 26 controls each of the increase bending devices 24a, 24b, 25a, 25b based on the instruction, and applies a predetermined increase bending force to the working roll chocks 5 and 6. As a result, a predetermined load can be applied only between the upper and lower work rolls and the reinforcing roll without applying a load between the upper and lower work rolls. When the increase bending device has a balancer function for lifting the weight of the work roll, the order of steps S200 and S202 is reversed, that is, the upper and lower work rolls are subjected to the increase bending force. The gap may be adjusted.
[0091]
　Next, the inter-roll cross control device 23 puts the rolls in a state of being stopped in rotation (S204). Then, in the roll stopped state, the downward load detection devices 28a and 28b and the downward downward load detection devices 29a and 29b detect the downward load on the working side and the drive side, respectively, and the upward and downward load difference calculation unit 32 and It is output to the lower pressure lower load difference calculation unit 33. Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. Calculate the difference. The calculated load difference in the rolling direction when the roll is stopped is input to the inter-roll cross control device 23 to be set as a reference value 1 (corresponding to the "first reference value" of the present invention), and is set to the reference value 1. Based on this, the first control target value is calculated (S206).
[0092]
　When the first control target value is calculated, the upper work roll 1 and the lower work roll 2 are then rotated, and the processing at the time of roll rotation is started. The inter-roll cross control device 23 drives the drive motor 21 by the drive motor control device 22 to rotate the work roll at a predetermined rotation speed and a predetermined rotation direction (S208). When the work roll is rotated, the upward and downward load detecting devices 28a and 28b and the downward and downward load detecting devices 29a and 29b detect the downward load on the working side and the driving side, respectively, and the upward and downward load difference calculation unit 32 And, it is output to the lower pressure lower load difference calculation unit 33. Upon receiving the input of the downward load, the upper reduction downward load difference calculation unit 32 and the lower reduction downward load difference calculation unit 33 receive the reduction direction load, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, respectively. The difference is calculated, and the calculated load difference in the rolling direction during roll rotation is output to the inter-roll cross control device 23 (S210).
[0093]
　The inter-roll cross control device 23 compares the reduction load difference during roll rotation calculated in step S210 with the first control target value calculated in step S206, and determines whether or not they match. Is determined (S212). In the determination in step S212, not only when the reduction load difference during roll rotation and the first control target value completely match, but also the first control target value of the reduction direction load difference during roll rotation. It shall also include the case where the deviation from is within the predetermined range. When it is determined in step S212 that the load difference in the rolling direction during roll rotation is not the first control target value or is not within the allowable range, the inter-roll cross control device 23 refers to the roll chock position control device 16. Then, it is instructed to adjust the position of the work roll chock of the roll system that does not satisfy the requirement of step S212 (S214). Then, when the positions of the upper and lower work roll chocks are adjusted, the process from step S210 is executed again. At this time, the position of the upper reinforcing roll chock may be controlled instead of the upper working roll chock so that the differential load generated by the thrust force between the upper working roll and the reinforcing roll is reduced.
[0094]
　When it is determined in step S212 that the reduction load difference at the time of roll reversal matches the first control target value or is within the permissible range thereof, the inter-roll cross control device 23 is shown in FIG. 7B. Move to processing.
[0095]
(Calculation of Reference Value 1 and First Control Target Value)
　Here, the calculation of the reference value 1 and the first control target value will be described in detail based on FIG. 8A. First, as shown on the upper side of FIG. 8A, in the roll gap open state, the upper roll system composed of the upper working roll 1 and the upper reinforcing roll 3 and the lower roll system composed of the lower working roll 2 and the lower reinforcing roll 4 are used. , Each stop the rotation of the roll. At this time, since the upper work roll 1 and the lower work roll 2 are separated from each other, each roll system is in an independent state. In this roll stopped state, the reduction direction load on the working side of the upper roll system and the reduction direction load on the drive side, and the reduction direction load on the work side of the lower roll system and the reduction direction load on the drive side are measured. Then, from these measured values, the reduction load difference, which is the difference between the reduction load on the working side and the reduction load on the drive side, is calculated for each of the upper roll system and the lower roll system (P31, P32). The reduction load difference of each roll system is calculated by the following equation (5).
[0096]
[Number 5]

[0097]
　Here, P 0 df1 T is the difference between the measured values ​​of the load in the downward direction between the working side and the drive side of the upper roll system in the roll stopped state (upper reference value 1 T ), and P 0 df1 B is the roll stopped state. It is the difference (lower side reference value 1 B ) of the reduced load measurement value between the working side and the driving side of the lower roll system in . Step reference value 1 of the S206, the upper reference value 1 T and the lower reference value 1 B points to. Also, P 0 W T is upper roll system of the working side of the rolling direction measured load, P in the roll stop state 0 W B is the rolling direction measured load of the working side of the lower roll system in roll standstill. Then, P 0 D T is upper roll system drive side pressure direction load measurement, P in the roll stop state 0 D B is the rolling direction measured load on the drive side of the lower roll system in roll standstill.
[0098]
　Then, the first control target value is set based on the reference value 1. Here, in calculating the first control target value, the relationship between the load difference in the rolling direction when the roll is stopped and when the roll is rotated is investigated. In this study, for example, as shown in FIG. 9, in a rolling mill having the same configuration as that of FIG. 5, the upper working roll 1 and the lower working roll 2 are separated from each other to open a roll gap between the working rolls 1 and 2. It was in a state. An increase bending force is applied to the upper work roll chock 5a and 5b and the lower work roll chock 6a and 6b by an increase bending device (not shown) in a state where the work rolls 1 and 2 are separated from each other.
[0099]
　Assuming that a cross angle between the rolls is generated between the lower work roll 2 and the lower reinforcement roll 4, when the lower work roll 2 and the lower reinforcement roll are rotated, as shown in FIG. 9, the lower work roll 2 and the lower A thrust force is generated between the reinforcing roll 4 and the lower reinforcing roll 4, and a moment is generated in the lower reinforcing roll 4. Due to this moment, the load applied to the downward load detecting device 10b on the driving side becomes larger than the load applied to the downward load detecting device 10a on the working side, and a reduction load difference occurs. On the other hand, in the state where the rolls are stopped, the relative slip in the roll axial direction does not occur between the lower work roll 2 and the lower reinforcing roll 4, so that no inter-roll thrust force is generated. Therefore, the downward load detection devices 10a and 10b detect the downward load that is not affected by the thrust force between the rolls.
[0100]
　FIG. 10 shows a change in the reduction load difference, which is the difference between the reduction load detected on the drive side and the work side, when the roll is stopped and when the roll is rotated. A predetermined cross angle between the rolls was provided between the lower working roll 2 and the lower reinforcing roll 4, a reduction load was detected when the roll was stopped, and then the roll was rotated to detect the reduction load. FIG. 10 shows a small rolling mill having a working roll diameter of 80 mm, when the cross angle between rolls of the lower working roll is changed by 0.1 ° so as to face the exit side on the drive side, and when the roll is forward and reverse. This is a measurement result in which a change in the load difference in the rolling direction is detected. The increment bending force applied to each work roll chock was 0.5 tonf / chuck. As shown in FIG. 10, the reduction load difference when the roll is rotated becomes larger in the negative direction than the reduction load difference when the roll is stopped. In this way, the load difference in the rolling direction is different between when the roll is stopped and when the roll is rotated.

The scope of the claims
[Claim 1]
　A four-stage or higher rolling mill having a plurality of rolls, including at least a pair of working rolls and a pair of reinforcing rolls supporting the working rolls, and
　any one of the rolls arranged in the rolling direction. As a reference roll,
　a load detecting device that detects a
　rolling load acting in the rolling direction of the roll at the rolling fulcrum positions on the working side and the driving side of the reinforcing roll, and at least a roll chock of the roll other than the reference roll. On the other hand, with respect to a pressing device provided on either the entry side or the exit side of the material to be rolled in the rolling direction to press the roll chock in the rolling direction, and
　at least the roll chock of the roll other than the reference roll, the rolling direction. The drive device that is provided so as to face the pressing device and moves the
　roll chock in the rolling direction, and the rolling direction position of the roll chock of the reference roll are fixed as reference positions and detected by the load detecting device on the working side. The driving device is driven so that the rolling reduction load difference, which is the difference between the rolled rolling load and the rolling load detected by the load detecting device on the driving side, is within an allowable range, and the reference is made. A rolling mill comprising a position control device for controlling the position of the roll chock of the roll other than the roll in the rolling direction
.
[Claim 2]
　The rolling mill according to claim 1, wherein the roll located at the bottom or the top of the plurality of rolls in the rolling direction is the reference roll.
[Claim 3]
　A bending device for applying a bending force to the roll is provided, and the
　position control device opens a roll gap between the working rolls and the bending device with respect to the roll chock on the roll side to be adjusted. The rolling mill according to claim 1 or 2, wherein a bending force is applied by the rolling mill.
[Claim 4]
　The rolling mill according to any one of claims 1 to 3, wherein the driving device is a hydraulic cylinder provided with a roll chock position detecting device.
[Claim 5]
　A method of setting a rolling mill,
　wherein the rolling mill includes a plurality of rolls including at least a pair of working rolls and a pair of reinforcing rolls supporting the working rolls, and rolling fulcrums on the working side and the driving side of the reinforcing rolls. It is a rolling mill having four or more stages equipped with a load detecting device for detecting a load in the rolling direction acting in the rolling direction of the roll at a position, and is
　carried out before adjusting the zero point of the rolling position or before starting rolling,
　and is arranged in the rolling direction. Using any one of the rolls as a reference roll, the rolling
　reduction is the difference between the rolling down load detected by the load detecting device on the working side and the rolling down load detected by the load detecting device on the driving side. The directional load difference is calculated,
　and the rolling direction position of the roll chock of the reference roll is fixed as the reference position so that the reduction load difference is within the allowable range, and the roll chock of the roll other than the reference roll is fixed. A
method for setting a rolling mill, which adjusts the position of the roll chock by moving the roll chock in the rolling direction of the material to be rolled .
[Claim 6]
　The method for setting a rolling mill according to claim 5, wherein the roll located at the lowest end or the uppermost portion in the rolling direction among the plurality of rolls is the reference roll.
[Claim 7]
　In the four-stage rolling mill,
　a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are placed on the upper roll system, and a plurality of rolls provided on the lower side in the rolling direction with respect to the material to be rolled are lowered. As the roll system, the
　work roll is opened for each of the upper roll system and the lower roll system in a state where the roll gap of the work roll is opened and a bending force is applied to the roll chock of the work roll by a bending device.
　After completing the first step of adjusting the positions of the roll chock and the roll chock of the reinforcing roll and the first step, the working roll is put into a kiss roll state, and the upper roll system and the lower roll system The second step of adjusting the position of the roll chock
is carried out, and in
　the first step, the
　roll is rotated in a predetermined rotation direction, and the work is performed on each of the upper roll system and the lower roll system. A first reference that detects the rolling load on the side and the driving side and calculates the first reference value based on the rolling load difference, which is the difference between the rolling load on the working side and the rolling load on the driving side.
　By reversing the rotation direction of the roll in the value calculation step, the rolling load on the working side and the rolling direction on the driving side are detected for each of the upper roll system and the lower roll system, respectively, and the rolling direction load on the working side is used. A first control target value calculation step for calculating a first control target value based on a deviation between the rolling down load difference, which is the difference from the rolling reduction load on the drive side, and the first reference value.
　The roll chock of the work roll of the roll system on the reference roll side or the roll system on the opposite side of the reference roll so that the load difference in the reduction direction is within the allowable range of the first control target value. The first adjustment step of moving the roll chock of the work roll or the reinforcement roll in the rolling direction to adjust the position of the roll chock
is carried out, and in
　the second step, the work roll is kissed. In this state, the
　roll is rotated in a predetermined rotation direction to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction load on the work side and the reduction direction load are described. The
　upper roll system and the said upper roll system and the said by reversing the rotation direction of the roll and the second reference value calculation step which calculates the second reference value based on the reduction direction load difference which is the difference from the reduction direction load on the drive side. For each of the lower roll systems, the reduction direction load on the work side and the drive side is detected, and the reduction direction load difference, which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side, and the second reference value. The second control target value calculation step for calculating the second control target value based on the deviation from the
　above, and the above so that the reduction load difference is within the allowable range of the second control target value. With one of the roll system or the lower roll system as the reference roll system, the roll chocks of each roll of the other roll system are controlled simultaneously and in the same direction while maintaining the relative positions between the roll chocks, and the positions of the roll chocks are controlled. The
method for setting the rolling mill according to claim 6, wherein the second adjusting step for adjusting the above and the second adjusting step are carried out.
[Claim 8]
　In the six-stage rolling mill having intermediate rolls between the working roll and the reinforcing roll,
　a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are used as an upper roll system and the material to be rolled. With a plurality of rolls provided on the lower side in the rolling direction as the lower roll system,
　the roll gap of the working roll is opened, and a bending force is applied to the roll chock of the intermediate roll by a bending device. For each of the upper roll system and the lower roll system, the first step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the reinforcing roll, and the
　operation after completing the first step. With the roll gap of the roll kept open and the bending force applied by the bending device to the roll chock of the working roll, the roll chock of the intermediate roll is applied to each of the upper roll system and the lower roll system.
　After completing the second step of adjusting the position of the work roll with the roll chock and the second step, the work roll is put into a kiss roll state, and the roll chocks of the upper roll system and the lower roll system are placed. a third step of adjusting the position,
carried out,
　wherein in the first step,
　by rotating the roll in a predetermined rotational direction, each said upper roll system and the lower roll systems, the work side and drive The first reference value calculation step of detecting the rolling load on the side and calculating the first reference value based on the rolling load difference which is the difference between the rolling load on the working side and the rolling load on the driving side. When,
　By reversing the rotation direction of the roll, the reduction direction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction direction load on the work side and the reduction direction load on the drive side are detected. The first control target value calculation step for calculating the first control target value based on the deviation between the reduction direction load difference and the first reference value, and the
　reduction direction load difference are the first. The roll chock of the intermediate roll of the roll system on the reference roll side, and the roll chock or reinforcement of the intermediate roll of the roll system on the opposite side of the reference roll so as to be within the allowable range of the control target value. A first adjustment step of moving any of the roll chocks of the roll in the rolling direction to adjust the position of the roll chock
is performed, and in
　the second step, the
　roll is rotated in a predetermined rotation direction. For each of the upper roll system and the lower roll system, the reduction direction load on the work side and the drive side is detected, and the reduction direction which is the difference between the reduction direction load on the work side and the reduction direction load on the drive side. The second reference value calculation step for calculating the second reference value based on the load difference and
　the rolling direction of the roll are reversed to reduce the working side and the driving side for the upper roll system and the lower roll system, respectively. The directional load is detected, and the second control target value is calculated based on the deviation between the reduction direction load difference, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, and the second reference value. The second control target value calculation step to be performed,
　The roll chock of the work roll of the roll system on the reference roll side and the roll system on the opposite side of the reference roll so that the load difference in the reduction direction is within the allowable range of the second control target value. A second adjustment step of moving either the roll chock of the work roll or the roll chock of the intermediate roll and the roll chock of the reinforcing roll in the rolling direction to adjust the position of the roll chock
is carried out, and the first adjustment step is performed
　. In step 3, the work roll is put into a kiss roll state, the
　roll is rotated in a predetermined rotation direction, and the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system. The third reference value calculation step for calculating the third reference value based on the reduction load difference, which is the difference between the reduction load on the working side and the reduction load on the drive side, and
　the rotation direction of the roll. By reversing, the reduction load on the work side and the drive side is detected for each of the upper roll system and the lower roll system, and the reduction is the difference between the reduction load on the work side and the reduction load on the drive side. The third control target value calculation step for calculating the third control target value based on the deviation between the directional load difference and the third reference value, and the
　reduction direction load difference is the allowable range of the third control target value. The roll chocks of each roll of the other roll system are simultaneously and the same while maintaining the relative positions between the roll chocks, with one of the upper roll system and the lower roll system as the reference roll system so as to have a value within. The
method for setting a rolling mill according to claim 6 , wherein a third adjustment step of adjusting the position of the roll chock by controlling the direction is performed.
[Claim 9]
　In the four-stage rolling mill,
　a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are placed on the upper roll system, and a plurality of rolls provided on the lower side in the rolling direction with respect to the material to be rolled are lowered. As the roll system, the
　work roll is opened for each of the upper roll system and the lower roll system in a state where the roll gap of the work roll is opened and a bending force is applied to the roll chock of the work roll by a bending device.
　After completing the first step of adjusting the positions of the roll chock and the roll chock of the reinforcing roll and the first step, the working roll is put into a kiss roll state, and the upper roll system and the lower roll system The second step of adjusting the position of the roll chock
is carried out, and in
　the first step, with
　the rotation of the roll stopped, the working side of each of the upper roll system and the lower roll system And the rolling load on the driving side is detected, and the first reference value is calculated based on the rolling load difference which is the difference between the rolling load on the working side and the rolling load on the driving side, and the first reference value is calculated. The first control target value calculation step for setting the first control target value based on the reference value, and the
　rolling direction of the working side and the driving side for each of the upper roll system and the lower roll system by rotating the roll. The first load difference calculation step of detecting the load and calculating the rolling load difference, which is the difference between the rolling load on the working side and the rolling load on the driving side,
　The roll chock of the working roll of the roll system on the reference roll side or the roll system on the opposite side of the reference roll so that the load difference in the reduction direction is within the allowable range of the first control target value. The first adjustment step of moving the roll chock of the work roll or the reinforcement roll in the rolling direction to adjust the position of the roll chock
is carried out, and in
　the second step, the work roll is kissed. In this state, with
　the rotation of the roll stopped, the reduction load on the working side and the driving side is detected for each of the upper roll system and the lower roll system, and the reducing load on the working side and the driving With the second control target value calculation step of calculating the second reference value from the reduction direction load difference which is the difference from the side reduction direction load and setting the second control target value based on the second reference value. , The
　roll is rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction load on the work side and the reduction load on the drive side. The
　upper roll system or the lower portion so that the second load difference calculation step for calculating the reduction load difference, which is the difference, and the reduction direction load difference are within the allowable range of the second control target value. A second roll system in which one of the roll systems is used as a reference roll system and the roll chocks of each roll of the other roll system are controlled simultaneously and in the same direction while maintaining the relative positions between the roll chocks to adjust the position of the roll chocks. The
method for setting the rolling mill according to claim 6 , wherein the adjustment step of
[Claim 10]
　In the six-stage rolling mill having intermediate rolls between the working roll and the reinforcing roll,
　a plurality of rolls provided on the upper side in the rolling direction with respect to the material to be rolled are used as an upper roll system and the material to be rolled. With a plurality of rolls provided on the lower side in the rolling direction as the lower roll system,
　the roll gap of the working roll is opened, and a bending force is applied to the roll chock of the intermediate roll by a bending device. For each of the upper roll system and the lower roll system, the first step of adjusting the positions of the roll chock of the intermediate roll and the roll chock of the reinforcing roll, and the
　operation after completing the first step. With the roll gap of the roll maintained in an open state and a bending force applied by a bending device to the roll chock of the working roll, the roll chock of the intermediate roll is applied to each of the upper roll system and the lower roll system.
　After completing the second step of adjusting the position of the work roll with the roll chock and the second step, the work roll is put into a kiss roll state, and the roll chocks of the upper roll system and the lower roll system are placed. In 　the first step 　, the working side and the driving side of the upper roll system and the lower roll system, respectively, with the rotation of the roll stopped ,
are carried out. The first reference value is calculated from the difference in the rolling direction, which is the difference between the rolling load on the working side and the rolling load on the driving side, and based on the first reference value. The first control target value calculation step for setting the first control target value, and

　By rotating the roll, the reduction load on the working side and the driving side is detected for each of the upper roll system and the lower roll system, and the difference between the reducing load on the working side and the reducing load on the driving side. The first load difference calculation step for calculating the
　reduction direction load difference, and the roll system on the reference roll side so that the reduction direction load difference is within the allowable range of the first control target value. A first method of adjusting the position of the roll chock by moving either the roll chock of the intermediate roll and the roll chock or the reinforcing roll of the intermediate roll of the roll system opposite to the reference roll in the rolling direction. in the adjusting step,
carried out,
　and in the second step,
　in a state where the rotation of the roll is stopped, for each of the upper roll system and the lower roll system, detecting the pressure direction load of the working side and the driving side Then, the second reference value is calculated from the reduction direction load difference, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, and the second control target value is calculated based on the second reference value. The second control target value calculation step for setting and the
　roll are rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, and the reduction on the work side. A second load difference calculation step for calculating the reduction direction load difference, which is the difference between the directional load and the reduction direction load on the drive side, and
　The roll chock of the work roll of the roll system on the reference roll side and the roll system on the opposite side of the reference roll so that the load difference in the reduction direction is within the allowable range of the second control target value. A second adjustment step of moving either the roll chock of the work roll or the roll chock of the intermediate roll and the roll chock of the reinforcing roll in the rolling direction to adjust the position of the roll chock
is performed , and the first adjustment step is performed
　. In step 3, the working roll is put into a kiss roll state, and in a state where
　the rotation of the roll is stopped, the downward load on the working side and the driving side is detected for each of the upper roll system and the lower roll system. The third reference value is calculated from the reduction direction load difference, which is the difference between the reduction direction load on the working side and the reduction direction load on the drive side, and the third control target value is set based on the third reference value. The third control target value calculation step and the
　roll are rotated to detect the reduction load on the work side and the drive side for each of the upper roll system and the lower roll system, respectively, and the reduction load on the work side. The third load difference calculation step for calculating the reduction load difference, which is the difference between the reduction direction load and the reduction direction load on the drive side, and the
　reduction direction load difference are values ​​within the allowable range of the third control target value. As described above, one of the upper roll system and the lower roll system is used as a reference roll system, and the roll chocks of each roll of the other roll system are controlled simultaneously and in the same direction while maintaining the relative positions between the roll chocks. The
method for setting the rolling mill according to claim 6 , wherein the third adjustment step of adjusting the position of the roll chock is carried out.