JPH10263656A - Method for rolling plate and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for rolling plate and device therefor to execute rolling operation so that the elongation percentage of rolling stock becomes equal on the left and right sides in rolling metal plate. SOLUTION: In the rolling method using >=4-high multiroll mill, from the measured value of thrust reaction force in the direction of roll shaft on all the rolls except at least back-up rolls under the tightened state of kiss rolls and from the measured value of reaction force of back-up rolls effecting in the direction of reduction at each of the rolling-down supporting points of upper and lower back-up rolls either or both of the zero point of rolling-down units and the deformation characteristic of rolling mill are obtained. Based on the obtained matter, the rolling-down position at the time of operation of rolling is set and controlled, or using the measured values at the time of rolling of the thrust reaction force of rolls except the back-up rolls and the reaction force of back-up rolls, the rolling-down position is set and controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling method for rolling a metal plate such as steel, and a rolling mill facility.

[0002]

2. Description of the Related Art One of the important issues in the rolling operation of a metal sheet material is to make the elongation rate of the rolled material equal between the working side and the driving side. In the following, the working side and the driving side will be referred to as left and right for simplicity of notation. When the elongation rate becomes uneven left and right, not only the planar shape and dimensional accuracy of a rolled material such as a camber and a plate thickness wedge are deteriorated, but also a passing trouble such as meandering and tail drawing may occur.

[0003] As an operating means for equalizing the right and left elongation rates, there is used a right and left difference of a rolling position of a rolling mill, that is, a rolling leveling operation. Normally, the operation of rolling leveling, setting before rolling, the operation during rolling, in most cases, the operator is operating while carefully observing the rolling operation, but the above-mentioned poor quality of the camber and the thickness wedge and It cannot be said that threading troubles have been sufficiently controlled.

Japanese Patent Publication No. 58-51771 discloses a technique for performing a rolling leveling control based on the ratio of the load cell load of a rolling mill to the sum of the left and right differences. Includes various disturbances in addition to the influence of the meandering amount of the rolled material, and the control based on the ratio of the left-right difference may be a control that promotes the meandering, and provides a sufficient effect. Not yet.

Japanese Unexamined Patent Publication (Kokai) No. 59-191510 discloses a technique for operating the rolling leveling by directly detecting the displacement of the rolled material on the entry side of the rolling mill, that is, the meandering amount. However, during rolling of long material or tandem rolling, even if rolling leveling is inappropriate, depending on the weight of the rolled material on the upstream side of the rolling mill and the restraining conditions of the rolling mill on the upstream side, the actual level may be reduced. In many cases, meandering does not occur in the rolled material on the side. In such a case, the meandering amount cannot be detected even though there is poor rolling leveling. It cannot be used as a means for controlling Further, for example, even when the meandering amount on the rolled material exit side is detected, the detected value includes the difference between the left and right material speeds on the exit side of the rolling mill and the width due to the movement of the rolled material camber already existing on the rolling mill exit side. Since the directional displacements are superimposed, it is difficult to use the optimization of the rolling leveling control for equalizing the elongation rate of the rolled material in the roll bite of the rolling mill at the time when the meandering amount is measured. is there.

[0006]

As described above, the method of directly detecting the amount of meandering is not capable of optimizing the reduction leveling by itself, and the method of directly detecting the phenomenon occurring in the roll bite. Since the measurement is not performed, there is an essential drawback that disturbance is likely to occur, and that the rolling leveling control is delayed.

[0007] On the other hand, the difference between the left and right of the rolling load conveys information on the asymmetry of the phenomenon occurring in the roll bite without time delay, and can be the most important information for the optimal control of the rolling leveling. Therefore, in the present invention, the disturbance included in the left-right difference of the rolling load detected from the load cell is specified, and the right-left difference of the rolling phenomenon occurring between the rolled material and the work roll is accurately estimated to optimize the reduction leveling. And a sheet rolling machine for realizing the method.

[0008]

As a result of close investigation and analysis, the inventors of the present application have found that the difference between the left and right of the rolling load measured by the load cell of the rolling mill is the distribution of the rolling load between the rolled material and the work roll. In addition to the left-right asymmetry regarding the mill center, for example, in the case of a four-high rolling mill, between a work roll and a reinforcing roll, in the case of a six-high rolling mill, a work roll and an intermediate roll,
It was found that the thrust force acting in the roll axis direction between the intermediate roll and the reinforcing roll was included as the largest factor. The thrust force acting between these rolls gives an extra moment to the rolls, and the difference between the left and right rolling loads changes to balance this moment. -It is a serious disturbance for the purpose of grasping the left-right asymmetry of the rolling load distribution generated between the work rolls.
Further, since the inter-roll thrust force is not only its magnitude during the rolling operation but also sometimes reverses even in the direction, it is very difficult to accurately estimate in advance. In most cases, the rolling zero adjustment of the rolling mill is performed by tightening the kiss rolls to a predetermined zero adjustment load by tightening the kiss rolls. Is added as a disturbance. In the adjustment of the rolling zero, the rolling position is reset so that the load measured by the load cells on the working side and the driving side becomes equal to a predetermined load, and the zero of the rolling leveling is also reset at the same time. At this time, if disturbances are included in the left-right difference of the load cell load due to the above-described thrust force between the rolls acting, the zero adjustment of the accurate reduction leveling cannot be performed, and the subsequent reduction leveling setting is always performed. The error of this zero point will be included. Furthermore, a kiss roll tightening test is also performed when grasping the rigidity of the rolling mill, that is, the lateral asymmetry with respect to the mill center of the deformation characteristics of the rolling mill as disclosed in JP-A-6-182418, but in this case, However, the above-described thrust force between rolls causes a serious error.

The present invention has solved the above-mentioned various problems, and the gist thereof is as follows. (1) In a rolling method using a multi-stage rolling mill of four or more stages, measured values of the axial thrust reaction force acting on at least all the rolls other than the reinforcing rolls in the kiss roll tightened state, and each of the upper and lower reinforcing rolls From the measured value of the reinforcing roll reaction force acting in the rolling direction at the rolling fulcrum position,
A sheet rolling method characterized in that one or both of a zero point of a rolling device and a deformation characteristic of a rolling mill are obtained, and a rolling position is set and / or controlled at the time of rolling, based on this.

(2) In a rolling method using a multi-high rolling mill having four or more stages, at least one of the upper and lower, preferably both upper and lower roll assemblies, the axial thrust counteracting on all the rolls other than the reinforcing rolls. From the measured value of the force and the measured value of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position of the reinforcing roll, a target value of the rolling position operation amount of the rolling mill is calculated, and the target of the rolling position operation amount is calculated. A sheet rolling method, wherein a rolling position control is performed based on a value.

(3) In a rolling method using a multi-high rolling mill having four or more stages, at least one of the upper and lower, preferably both upper and lower roll assemblies, the axial thrust reaction acting on all the rolls other than the reinforcing rolls. From the measured value of the force and the measured value of the reaction force of the reinforcing roll acting in the rolling direction at each rolling fulcrum position of the reinforcing roll, at least the asymmetry with respect to the mill center of the distribution of the load acting between the rolled material and the work roll in the roll axis direction. Plate rolling, wherein a target value of a rolling position operation amount of a rolling mill is calculated based on the calculation result, and a rolling position control is performed based on the target value of the rolling position operation amount. Method.

(4) An apparatus for measuring a thrust reaction force in the roll axial direction acting on all the rolls other than the reinforcing rolls in a multi-stage plate rolling mill having four or more stages, and a roll-down thrust force acting at each lowering fulcrum position of upper and lower reinforcing rolls. A sheet rolling mill comprising: a reinforcing roll reaction force measuring device; (5) A device for measuring the axial thrust reaction force acting on all the rolls other than the reinforcing rolls in a multi-stage plate rolling mill of four or more stages, and a reinforcing roll acting in a rolling direction at the position of each rolling fulcrum of the upper and lower reinforcing rolls. A reaction force measuring device and at least the thrust reaction force measurement value and the reinforcing roll reaction force measurement value as input data, and at least the asymmetry with respect to the mill center of the roll axial distribution of the load acting between the rolled material and the work roll. Or a calculation device for calculating the asymmetry of the distribution of the load acting between the upper and lower work rolls in the roll axis direction with respect to the mill center.

(6) A roll bending device is provided for at least one set of rolls other than the reinforcing roll, and at least one of the rolls having the roll bending device is provided with a roll chock for supporting a radial load; The device according to claim 2, wherein the device is configured to be separated into a roll chock that supports an axial thrust reaction force, and a device for measuring a thrust reaction force acting on the thrust reaction force supporting roll chock is provided. Plate rolling machine.

(7) A roll bending device is provided on at least one set of rolls other than the reinforcing roll, and the roll bending device has a mechanism capable of adding a vibration component having a frequency of 5 Hz or more to a set roll bending force. The plate rolling mill according to claim 4, characterized in that: (8) At least one set of rolls other than the reinforcing roll is provided with a roll bending device, and a slide having a degree of freedom in a roll axis direction between a load application portion of the roll bending device and a roll chock contacting the load application portion. 2. The plate rolling mill according to claim 1, further comprising a bearing mechanism.

(9) A roll bending device is provided on at least one set of rolls other than the reinforcing roll, and an elasticity against out-of-plane deformation is provided between a load application portion of the roll bending device and a roll chock contacting the load application device. The sheet rolling according to claim 1, characterized in that the sheet rolling has a load transmitting portion in which a liquid is sealed in a closed space at least partially covered with a thin outer skin having a deformation resistance of 5% or less of the maximum value of the roll bending force. Machine.

(10) A mechanism for shifting the roll in the axial direction to at least one set of rolls other than the reinforcing roll,
2. The sheet rolling mill according to claim 1, wherein the shift mechanism has a function of giving a minute shift swing having an amplitude of 1 mm or more and a cycle of 30 seconds or less.

The first aspect of the present invention discloses a means for separating disturbance caused by a thrust force between rolls, particularly when adjusting a rolling reduction zero point by tightening a kiss roll and extracting left-right asymmetry of deformation characteristics of a rolling mill. . In the first aspect, the thrust reaction force acting on the rolls other than the reinforcing roll and the reinforcing roll reaction force acting on the lowering fulcrum positions of the upper and lower reinforcing rolls when the kiss roll is tightened are measured. Here, the thrust reaction force is to maintain the rolls in a fixed position against the resultant force of the thrust forces generated by the presence of a small cross angle between the rolls mainly on the contact surface of each roll body, with respect to each roll. Usually, the reaction force is generated on the keeper plate via a roll chock. However, in the case of a rolling mill having a roll axial shift device, it is generated on the shift device. In addition, the reaction force of the reinforcing roll acting on each lowering fulcrum position of the upper and lower reinforcing rolls is usually measured by a load cell. However, when a hydraulic pressure lowering device is provided, a method of calculating from the measured value of the pressure in the lowering cylinder may be used. By measuring the thrust reaction force and the reinforcement roll reaction force, for example, in the case of a four-high rolling mill, the unknowns of the forces acting on the respective rolls and the forces involved in the equilibrium condition of the moment are as follows: Becomes

[0018] ^T _B T: thrust reaction force acting on the top back up roll chock ^T _WB T: thrust force acting between the upper work roll-up roll T _WW: thrust force T _WB ^B acts between the upper and lower work rolls: lower work thrust T _B ^B acting between the rolls - rolls: thrust counterforces acting on the lower reinforcing roll chocks p ^df _WB ^T: top work roll - reinforcing laterality p ^df _WB line load distribution between rolls ^B: lower work rolls ^-Left- right difference in line load distribution between reinforcing rolls p ^df _WW : Left-right difference in line load distribution between upper and lower work rolls Here, the linear load distribution is the distribution of the tightening load acting on each roll body in the roll axis direction. The load per unit body length is called a linear load. If it is possible to measure the thrust reaction force acting on the roll chock of the reinforcing roll, it is obvious that more accurate calculation is possible and it is preferable, but the roll chock of the reinforcement roll generates a much larger reinforcement roll reaction force than the thrust reaction force. Since the thrust reaction force is measured at the same time, it is generally not easy to measure the thrust reaction force. Here, it is assumed that the measured value of the thrust reaction force of the reinforcing roll cannot be used. If the thrust reaction force of the reinforcing roll could be measured, the number of equations would be larger than the number of unknowns in the following explanation. It will be better.

The equations that can be used to determine the eight unknowns are a total of eight equations: four equilibrium conditions for the force in the roll axis direction of each roll and four equilibrium conditions for the moment of each roll. . Here, it is assumed that the equilibrium condition of the vertical force of each roll has already been taken into consideration, and the factors related to the equilibrium condition of the vertical force are also excluded from the unknowns. By solving the equilibrium conditional expression of the force and moment of each roll with respect to the above eight unknowns, it becomes possible to obtain all the above unknowns.

By obtaining all the forces related to the left-right asymmetry regarding the mill center as described above,
It is possible to accurately calculate the roll deformation including the left-right asymmetry, and by independently subtracting the contribution of the roll deformation from the mill stretch amount obtained from the relationship between the tightening load when tightening the kiss roll and the rolling position, left and right independently It is possible to accurately determine the deformation characteristics of the left and right housing / press-down systems.

On the other hand, with respect to the zero point of the rolling-down device, the true right and left uniform reduction when the thrust force between the rolls is not generated by the right-left difference of the roll flatness caused by the right-left difference of the line load distribution acting between the rolls. Since the position is deviated from the position, the error amount may be always corrected at the time of setting the rolling down, or more practically, the zero point itself may be corrected in consideration of the error amount. In any case, it is necessary to measure the reaction force of the reinforcement roll at the position of each of the rolling fulcrums of the reinforcement roll and the thrust reaction force of the parts other than the reinforcement roll to estimate the difference between the left and right line load distribution between the rolls. Even if any of the above measured values are missing, the unknowns become eight or more, and it becomes impossible to estimate the left-right difference in the linear load distribution between rolls.

When the rolling mill is not a four-high rolling mill and the number of intermediate rolls increases, the contact area between the rolls increases by one each time the number of intermediate rolls increases.
If the thrust reaction force of the intermediate roll is measured, the increasing unknowns are the two of the thrust force acting on the added contact area and the left-right difference of the linear load distribution. The two equations, ie, the axial force equilibrium condition equation and the moment force equilibrium equation, are increased, and all the solutions can be obtained by simultaneous equations with other roll-related equations. In this way, even in the case of a rolling mill with four or more stages, by measuring the thrust reaction force acting on at least all the rolls except the reinforcing roll,
It is possible to accurately determine the difference between the left and right of the line load distribution acting on all rolls in the kiss roll state, and to accurately perform the zero adjustment of the rolling device and the deformation characteristics of the rolling mill, especially including the left and right asymmetry Becomes possible.

[0023] Claims 2 and 3 disclose a sheet rolling method in which rolling leveling control during rolling is accurately performed based on a measured value of a rolling reaction force. For example,
In a normal four-high rolling mill, by measuring the roll axial thrust reaction force acting on the upper work roll and the reinforcement roll reaction force acting in the reduction direction at each reduction fulcrum position of the upper reinforcement roll, the upper work roll and the upper work roll are measured. The unknowns among the forces involved in the equilibrium conditional expression of the force and moment in the roll axis direction acting on the upper reinforcing roll are the following four.

[0024] T _B ^T: thrust counterforces acting on the upper roll chock T _WB ^T: thrust force acting between the upper work roll-backup rolls p ^df _WB ^T: left and right line load distribution between the upper work roll-backup rolls Difference p ^df : Left and right difference in linear load distribution between rolled material and work roll The above unknowns do not include the thrust force acting between the rolled material and work roll, for the following reason.

The thrust reaction force between the rolls is due to the contact between the elastic bodies, and the peripheral speeds of the rolls at the contact surface are almost the same. When a mismatch occurs in the component of the circumferential velocity vector in the roll axis direction, the friction force vector is in the direction along the roll axis direction.For example, even at a small cross angle of about 0.2 °, the ratio of the roll axial thrust force to the rolling load is It is around 30%, which is almost equal to the coefficient of friction. On the other hand, in the case of the thrust force acting between the rolled material and the work roll, at a position other than the neutral point in the roll bite, the speed of the rolled material does not match the work roll circumferential speed itself, Even when a cross angle of about 1 ° is given as in a roll cross mill, the direction of the friction force vector does not match the roll axis direction, and therefore, the roll axis direction component of the friction force vector in the roll bite is integrated. The obtained thrust force is about 5%, which is much smaller than the coefficient of friction. From the above, in the case of a normal rolling mill in which the work rolls are not positively crossed, the cross angle that can be caused by the gap between the roll chock and the housing window is usually 0.1 ° or less, so the thrust between the rolled material and the work rolls is You can see that the power can be ignored.

The equations that can be used to determine the above-mentioned four unknowns include two conditions for balancing the forces in the roll axis direction of the work roll and the reinforcing roll, and two conditions for the moment of the work roll and the reinforcing roll. Is a total of four,
By solving these simultaneously, it is possible to find all unknowns. If the above unknowns are obtained, the deformation of the upper roll system can be accurately calculated including the left-right asymmetric deformation.

Next, for the lower roll system,
The left and right difference of the linear load distribution between work rolls is required,
Since this is equal to the upper and lower sides of the equilibrium condition of the force acting on the rolled material, if the difference between the left and right of the linear load distribution between the lower work roll and the reinforcing roll is obtained, it is possible to calculate the deformation of the lower roll system including the asymmetric deformation. It becomes possible. In solving this problem, the following equation systems can be used: two equilibrium conditional expressions for forces in the roll axis direction of the lower working roll and the lower reinforcing roll, and two equilibrium conditional expressions for the moment of the lower working roll and the lower reinforcing roll.
The total number of unknowns is four, for example, the following five unknowns related to the above equation system when neither the thrust reaction force nor the reinforcing roll reaction force of the lower roll system can be measured.

T_B ^B : Anti-thrust acting on lower reinforcement roll chock
Force T_WB ^B ： Slur acting between lower work roll and reinforcing roll
Strike force T_W ^B : Anti-thrust acting on lower work roll chock
Power p^df _WB ^B： Line load distribution between lower work roll and reinforcing roll
Left-right difference P^dfB ： Reinforcement roll at lower fulcrum roll support point
Of the above unknowns, a well-managed rolling mill
Left and right difference p in line load distribution between work roll and reinforcing roll^df _WB ^B
Is the right and left difference p of the linear load distribution between the rolled material and the work roll ^dfCompared to
May be negligibly small, in which case p
^df _WB ^BFind all remaining unknowns by setting = 0
It becomes possible. If these conditions do not hold,
Also assume that at least one of the above unknowns is known
Or find all remaining unknowns by actual measurement
It becomes possible. More preferably, the lower roll system is used.
The thrust reaction force of the work roll and the reaction force of the reinforcement roll
If the right difference can be measured, the number of unknowns is less than the number of equations
More accurate by finding the least squares solution
Calculation becomes possible. If the above unknowns are found, lower row
Accurately calculate the deformation of the system including the asymmetric deformation
Roll deformation of the upper and lower rolls
Measured as a function of the reinforcing roll reaction force.
The deformation of the housing / rolling system is superimposed to determine the current rolling position.
By considering the gap between the upper and lower work rolls
It is possible to calculate the symmetry accurately, and the rolling mill deformation
The resulting thickness wedge can be calculated. More than
After making preparations, the viewpoint of meandering or camber control
To achieve the target value of the thickness wedge required by
The target value of the reduction position operation amount, especially the reduction level operation amount
It is possible to calculate, and according to this target value
Position control may be performed. In the above description,
Even if the lower roll system is replaced, the present invention
It goes without saying that it can be applied.

In the above description, asymmetry of the linear load distribution between the rolled material and the work roll is considered in consideration of only the left-right difference of the linear load, but the asymmetry of the linear load distribution in the roll axis direction is considered. In addition to the above-described asymmetry of the linear load, a phenomenon in which the center of the rolled material is passed at a position different from the mill center may be considered. In the present invention, the distance between the center of the rolled material and the mill center is referred to as an off-center amount. The off-center amount is basically controlled to be within a certain allowable amount by a side guide on the rolling mill entry side. If the off-center amount that can still occur cannot be ignored, it is preferable to estimate the off-center amount from a meandering sensor on the entrance or exit of the rolling mill, for example. In a case where such a sensor cannot be installed and an off-center amount that cannot be ignored can occur, for example, the following method is adopted.

It is impossible to separate and extract two unknowns, namely, the off-center amount and the left-right difference of the line load distribution between the rolled material and the work roll from the equilibrium condition formula of the moment of the work roll. Therefore, there are two cases, as described above, where the off-center amount is zero and only the left-right difference of the line load is unknown, and the left-right difference of the line load is zero and the off-center amount is unknown.
In each case, the target value of the rolling leveling operation amount is calculated, and for example, the target value of the actual rolling leveling operation amount is determined by the weighted average of the calculation results of the two. This weighting method will be adjusted as appropriate while observing the rolling situation, but as a general theory, a larger weight is assigned to the side with a smaller rolling level operation amount, and the value of the smaller operation amount is adopted. However, a more practical method is to multiply this by a tuning factor of usually 1.0 or less to obtain a control output.

In the above description, a four-high rolling mill has been described as an example. However, in the case of a rolling mill model having an increased number of intermediate rolls,
Each time the intermediate roll increases, the contact area between the rolls increases by one, and if the thrust reaction force of the intermediate roll is measured,
The increasing unknowns are the thrust force acting on the added contact area and the left-right difference of the linear load distribution. On the other hand, the available equations are the equilibrium condition equation and the moment equilibrium equation for the force in the roll axis direction of the roll. Is increased, and simultaneous with equations relating to other rolls, all solutions can be obtained. In this way, even in the case of a rolling mill with four or more stages, by measuring the thrust reaction force acting on at least all the rolls other than the reinforcing roll, the right and left difference in the linear load distribution acting between the rolls during the rolling can be calculated. It is possible to obtain all unknowns including the rolling reduction, and it is possible to calculate the optimum amount of rolling leveling operation as in the case of the four-high rolling mill.

Next, the case of a roll cross type plate rolling mill typified by a pair cross mill will be described. As described above, in the roll cross rolling mill, the traveling direction of the rolled material generally does not coincide with the direction of the peripheral speed vector of the work roll, and an angle is formed by a roll cross angle of about 1 °. As a result, a thrust force of about 5% of the rolling load is generated. Although this thrust force can be predicted with a certain degree of accuracy in advance, it is difficult to calculate an accurate value in advance because it is affected by the surface properties of the roll and the temperature and deformation characteristics of the rolled material. Therefore, in order to perform accurate rolling leveling control, it is necessary to obtain the thrust force acting between the rolled material and the work roll as an unknown. In this case, the number of equations is insufficient if only the equation system relating to one of the upper and lower roll assemblies is used as in the case of the normal four-high rolling mill as described above. It is necessary to use the equilibrium condition formula of the force in the roll axis direction and the equilibrium condition formula of the moment of all the upper and lower rolls. The number of equations in this case is
In the case of a four-high rolling mill, the number is eight, and the unknowns are the following eight.

[0033] T _B ^T: thrust counterforces acting on the upper roll chock T _WB ^T: thrust force acting between the upper work roll-backup roll T _MW: thrust force T _WB ^B acting between the rolled material - the work rolls: thrust T _B ^B acting between the lower work roll-backup roll: a thrust reaction force acting on the lower reinforcing roll chocks p ^df _WB ^T: difference between right and left of the line load distribution between the upper work roll-backup rolls p ^df _WB ^B: lower Left and right difference of line load distribution between work roll and reinforcing roll p ^df : Left and right difference of line load distribution between rolled material and work roll By solving these unknowns by the above equation system, between rolled material and work roll and between rolls It is possible to determine the difference between the left and right of the linear load distribution of the roll, and by using these calculated values, the roll deformation can be accurately determined for the left and right asymmetry of the roll gap, and the rolling leveling operation Target value can be calculated for.

A fourth aspect of the present invention discloses a sheet rolling mill for implementing the above-mentioned rolling method of the first, second and third aspects. As described above, in order to carry out the rolling method according to claims 1, 2, and 3, the rolling mill is provided with a measuring device for a roll axial thrust reaction force acting on all rolls other than a reinforcing roll, A measuring device for measuring the reaction force of the reinforcing roll acting in the rolling-down direction at each position of the rolling support point of the reinforcing roll must be provided. Here, the roll axial thrust reaction force measuring device is, for example, a device that detects a load acting on a keeper plate that restrains axial movement of the roll via a roll chock or a stud bolt that restrains the keeper plate. In the case of a rolling mill having a roll axial shift function, it is a device that detects a load applied to the shift device, and further, is mounted in a roll chock to directly detect a thrust force acting on an outer race of a thrust bearing. It may be a device that performs. In addition, the measurement device of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position of the upper and lower reinforcing rolls is generally a load cell arranged at the rolling fulcrum position, for example, a rolling mill having a hydraulic rolling device. In this case, a method of calculating from a measured value of the oil pressure in the reduction cylinder or a pipe directly connected to the reduction cylinder may be used. However, in this case, when the hydraulic pressure is rapidly changing the rolling position, a large error will occur in the measured value.Therefore, when collecting pressure data, take measures such as temporarily maintaining the rolling position. It is.

Claim 5 discloses a more specific form of a plate rolling mill for carrying out the rolling method of claims 1, 2, and 3. Claims 1, 2, and 3 have already been described.
In order to carry out the rolling method of (1), a roll axial direction thrust reaction force measuring device acting on a roll other than the reinforcing roll disclosed in claim 4, and a reinforcing device acting in a rolling direction at each rolling fulcrum position of the upper and lower reinforcing rolls. In addition to the roll reaction force measuring device, at least these measured values are input and the linear load distribution and asymmetry of the thrust force acting between the rolls or the linear load distribution and the thrust force acting between the rolled material and the work roll are input. An arithmetic unit for calculating the asymmetry of is required. Here, what is indispensable for the left-right asymmetric deformation analysis of the roll system, which must be finally performed for the reduction leveling setting control, is the asymmetry of the distribution of the load acting between the rolled material and the work roll in the roll axis direction with respect to the mill center. sex,
Alternatively, in the case of the kiss roll state, the roll axis distribution of the load acting between the upper and lower work rolls is asymmetry with respect to the mill center. An arithmetic unit that calculates as input data the measured value of the directional thrust reaction force and the measured value of the reinforcing roll reaction force acting in the rolling direction at the position of each rolling support point of the upper and lower reinforcing rolls is an essential requirement.

When measuring the thrust reaction force acting on the rolls other than the reinforcing rolls, in the above-described example of the measuring device, the measurement of the load applied to the outer race of the thrust bearing in the roll chock is performed. Excluding the device, an external force for holding the roll chock in the roll axis direction is measured. When a thrust reaction force measuring device of this type is used, a roll axial frictional force caused by a roll balance force or a roll bending force acting on each roll becomes a large disturbance of the measured thrust reaction force. That is, the roll moves slightly in the direction of the thrust force due to the resultant force of the thrust force acting on the body of each roll, and this slight displacement causes the elasticity of the keeper plate or the roll shift device that restrains the roll chock in the roll axis direction. The thrust reaction force is measured by inducing deformation, but when the roll chock is slightly displaced, the displacement of the roll chock from the load loading part of the roll bending device or roll balance device that is in contact with the roll chock is measured. Friction acts. Since the frictional force itself is generally difficult to measure, it becomes a disturbance of the measured thrust force. Claims 6 to 1
No. 0 discloses a sheet rolling mill that solves this problem.
In the following description and claims of the present invention, for simplicity of expression, they are collectively referred to as a roll bending device and a roll bending force, including a roll balancing force. According to claim 6, a roll bending device is provided on at least one set of rolls other than the reinforcing roll, and a roll chock of at least one of the rolls having the roll bending device, for example, a roll chock of an upper work roll, is provided with a roll bending. Roll chock that supports a radial load in the rolling direction such as force and a roll chock that supports a thrust reaction force in the roll axis direction, and a device for measuring the thrust reaction force acting on the roll chock for supporting the thrust reaction force. Is provided. In this case, the radial load supporting roll chock can have a structure that does not receive a thrust force by, for example, fitting the inner race of the bearing and the roll shaft with a clearance or using a cylindrical roller bearing that does not employ the inner race. With such a structure, even in the state where the roll bending force is acting, a slight displacement in the axial direction of the upper work roll is transmitted only to the thrust reaction force supporting chocks. Is negligibly small. on the other hand,
When the lower work roll has a structure in which the chocks are not separated like the upper work roll, and a thrust force acts on the lower work roll, a friction force corresponding to the roll bending force acts between the lower work roll and the upper work roll chock. Since the upper work roll chock does not support the thrust force, the upper work roll chock is slightly displaced in the direction in which the thrust force acts together with the lower work roll chock, and the reaction force of the thrust force acting on the lower work roll is also accurately determined via the lower work roll chock. Can be detected.

A seventh aspect of the present invention discloses a sheet rolling mill provided with a mechanism capable of applying a vibration component having a frequency of 5 Hz or more to the roll bending force. In this way, by superimposing the vibration component in addition to the predetermined force on the roll bending force, the frictional force between the load application portion of the roll bending force and the roll chock is greatly reduced, and the measurement accuracy of the measured thrust force value is improved. Significantly improved. This is because when the thrust force acts on the work roll as described above, the work roll is slightly displaced in the roll axis direction to measure the thrust force, but when the roll bending force is vibrating, This is because the work roll is displaced in the roll axis direction at the moment when the roll bending force becomes the smallest, thereby transmitting the thrust force. The frequency of the added vibration component is 5H
If it is less than z, the work roll deflection itself changes greatly in response to the vibration of the roll bending force, which has an adverse effect on the sheet crown and shape, and also reduces the effect of reducing the frictional force in the roll axis direction. The component is 5
Hz or more, preferably 10 Hz or more is appropriate.

An eighth aspect of the present invention discloses a plate rolling mill in which a slide bearing mechanism having a degree of freedom in the roll axis direction is provided between a load application portion of a roll bending device and a roll chock. Due to the existence of such a slide bearing mechanism, the frictional force between the load portion of the roll bending force and the roll chock is greatly reduced, and the measurement accuracy of the measured value of the thrust reaction force is greatly improved.

According to the ninth aspect, at least a portion of the outer wall between the load application portion of the roll bending device and the roll chock is covered with a thin outer skin having an elastic deformation resistance against out-of-plane deformation of 5% or less of the maximum value of the roll bending force. Disclosed is a plate rolling mill in which a load transmitting unit having a configuration in which a liquid is sealed in a closed space is inserted. The load transmitting part is narrowed between the load applying part of the roll bending device and the roll chock, but the thin outer skin has sufficient strength so that the internal liquid film does not break, and the thin outer skin has Resistance to out-of-plane deformation is 5% of maximum roll bending force
Because of the following, it is possible to sufficiently reduce the apparent frictional force acting from the load application portion of the roll bending device with respect to the minute displacement of the roll chock in the roll axis direction. If such a load transmitting section is not provided, the load loading section of the roll bending device and the roll chock come into solid contact with each other.
Before and after. On the other hand, when this load transmitting portion is inserted, the shear deformation resistance of the internal liquid film is almost negligible, so that the apparent frictional force is 5% or less of the maximum value of the roll bending force. The measurement accuracy of the reaction force measurement value is greatly improved.

According to a tenth aspect of the present invention, there is disclosed a plate rolling mill provided with a function of imparting a minute shift swing of an amplitude of 1 mm or more and a cycle of 30 seconds or less when a roll shift mechanism is provided on a roll other than the reinforcing roll. doing. In this way, the swing function is given to the roll shift mechanism, and by actually swinging, the direction of the frictional force acting between the load application part of the roll bending device and the roll chock is reversed. By taking the average value of the thrust reaction force, an accurate thrust reaction force can be measured. Here, the amplitude of 1 mm or more is 1 mm
If the amplitude is smaller than the above, the swing is absorbed by the play in the roll axis direction of the roll chocks and bearings and the deformation in the roll axis direction of the load application part of the roll bending device, so that the direction of the friction force does not reverse. It is. In addition, as for the oscillation cycle, one point of thrust reaction force data can be obtained only by taking an average value in this cycle, and the reduction position control corresponding thereto can be performed. The cycle time for performing the control is determined to be 30 seconds or less.

[0041]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following, for the sake of simplicity, all four-high rolling mills will be described as an example. However, as described above, the present invention similarly applies to five- or six-high rolling mills in which an intermediate roll is further added. Applicable.

FIG. 1 is a diagram showing an algorithm of a preferred embodiment for adjusting a rolling zero point of a four-high rolling mill in the sheet rolling method according to the first aspect of the present invention. The rolling zero point adjustment is performed after the roll change, and usually the kiss roll is tightened until the reinforcing roll reaction force reaches a predetermined zero adjustment load. At this time, the reduction level is also adjusted so that the reaction force of the left and right reinforcing rolls becomes equal, and then the reduction position is temporarily reset to zero. As the reinforcing roll reaction force, the reaction force of the upper or lower reinforcing roll may be used alone, or, for example, the average value of the reaction force of the upper and lower reinforcing rolls may be used. FIG.
In this state, the upper and lower and left and right reinforcing roll reaction forces and the thrust reaction force of the upper and lower work rolls are measured in this state, and the equilibrium equation for the axial force acting on the reinforcement roll and the work roll and the moment equilibrium condition From the formula, the thrust reaction force of the reinforcing rolls, the thrust force acting between the rolls, and the left / right difference in the linear load distribution are calculated. A specific example of this calculation method will be described below.

FIG. 2 schematically shows the force acting on each roll in the roll axis direction and the force related to the moment of each roll. Here, for the vertical force, only the left-right asymmetric component related to the moment of the roll is considered, and in order to further simplify the description, the width direction of the left-right asymmetric component of the linear load distribution acting between the rolls is considered. Coordinate 1
Only the following formula components are considered. In the case of actual application, the width direction coordinate 3
It is also possible to employ an asymmetric component obtained by superimposing the following components. Of the force components shown in FIG. 2, the measured values are available for the following four components.

P ^dfT : Reinforcement roll reaction force left / right difference at the position of the upper reinforcement roll ^pressing down point P ^dfB : Reinforcement roll reaction force left / right difference at the position of the lower reinforcing roll ^pressing down point T _W ^T : Thrust reaction force acting on the upper work roll T _W ^B : Thrust reaction force acting on the lower work roll The unknowns are the following eight variables.

[0045] ^T _B T: thrust reaction force acting on the top back up roll chock ^T _WB T: thrust force acting between the upper work roll-up roll T _WW: thrust force T _WB ^B acts between the upper and lower work rolls: lower work thrust T _B ^B acting between the rolls - rolls: thrust counterforces acting on the lower reinforcing roll chocks p ^df _WB ^T: top work roll - reinforcing laterality p ^df _WB line load distribution between rolls ^B: lower work rolls ^-Left- right difference in line load distribution between reinforcing rolls p ^df _WW : Left-right difference in line load distribution between upper and lower work rolls Note that the position of the point of application of the thrust reaction force acting on the reinforcing roll and the axial center position of the reinforcing roll in FIG. Distance h _B ^T and h
_B ^B, for example, it is assumed in advance identified by observing the rolls change in reaction force giving a known thrust force. In FIG. 2, the position of the point of application of the thrust reaction force of the work roll acts on the center position of the work roll. However, the position may be shifted from the position of the roll center depending on the type of work roll chock and the support mechanism. In such a case, the thrust reaction force position is identified by a method such as applying a known thrust force to the work roll.

From FIG. 2, the upper reinforcing roll, the upper working roll,
The equilibrium conditional expressions for the forces in the roll axis direction of the lower work roll and the lower reinforcing roll are as follows. _{^{-T WB T = T B T (}} 1) T WB T -T WW = T W T (2) T WW -T WB B = T W B (3) T WB B = T B B (4) The upper The equilibrium condition of the moment of the reinforcing roll, the upper working roll, the lower working roll, and the lower reinforcing roll is given by the following equation.

[0047] _{^{T WB T · (D B T}} / 2 + h B T) + p df WB T (l WB T) 2/12 = P df T · a B T / 2 (5) T WB T · D W T / 2 + T ^{_{WW · D W T / 2-}} p df WB T (l WB T) 2/12 + p df WW (l WW) 2/12 = 0 (6) T WB B · D W B / 2 + T WW · D W B / _{^{2 + p df WB B (l}} WB B) 2/12 -p df WW (l WW) 2/12 = 0 (7) T WB B · (D B B / 2 + h B B) -p df WB B (l WB B _{^{) 2/12 = -P df B}} · a B B / 2 (8) _{^{wherein, D B T, D B B}} , D W T, D W B , respectively upper and lower rolls diameter, there upper and lower work rolls diameter , L _WB
^T, l _WW, l _WB ^B, respectively on the rolls - the work rolls contact area, the upper and lower work rolls contact area, the lower back-up rolls -
This is the length of the work roll contact area in the roll axis direction. In addition,
In equations (5) and (8), T _B is calculated using equations (1) and (4).
And to erase the ^T and T _{^B B.} By simultaneously solving the above eight equations, all the eight unknowns can be obtained.

In the following procedure shown in FIG. 1, the right and left difference of the roll deformation amount in the zero roll state is calculated by using the above calculation result, and the left / right difference is converted into the position of the rolling fulcrum to correct the zero position of the rolling reduction. Calculate the quantity. The left-right difference in the roll deformation amount is mainly caused by the left-right asymmetric component of the linear load distribution acting between the rolls, and the main cause is the left-right difference in the roll flat deformation amount, which is already obtained p ^df _WB ^T , p ^df _WB ^B ,
It can be calculated immediately from p ^df _WW . By extrapolating the right and left difference of the total flat deformation amount at the roll body end position obtained from the calculation result to the position of the reduction roll fulcrum of the reinforcing roll, the correction amount of the zero reduction position can be calculated. When extrapolating the flat deformation, it is preferable to consider the asymmetry of roll deflection and the asymmetry of roll neck deformation.

The thrust force between the rolls generated at the time of zero adjustment is
Since it is unlikely that the same occurs during rolling, it is preferable that the rolling zero point serving as a reference for the rolling position is based on a state where the thrust force between the rolls is zero. For this reason, it is desired that an ideal state in which the left-right asymmetric load caused by the above-described thrust force between rolls does not occur be set as a true rolling zero point. That is, the position where the rolling position is moved in the direction to eliminate the left-right asymmetry amount of the roll deformation amount calculated above is set as a true zero point. By setting the rolling position zero point in this way, it is possible to perform accurate rolling setting in consideration of the left-right asymmetric load and deformation that occur during actual rolling.

In order to obtain the same effect, instead of correcting the rolling-down zero point as shown in FIG. 1, such a roll asymmetric deformation itself at the time of zero adjustment is stored. However, it is also possible to cope with a method of always correcting the amount when setting the actual reduction. Even with such a method, the zero point is substantially corrected at the time of the calculation of the reduction setting, and it is apparent that this embodiment is another embodiment of the present invention. Although only the left-right asymmetric deformation has been described here, there is a difference between the left-right total value of the reinforcing roll reaction force at the time of actual zero adjustment, that is, the right-left total value of the zero adjustment load and its target value. It is also important from the viewpoint of plate thickness accuracy to correct the rolling zero point including this left-right symmetric component. However, in this case, it is also possible to store the actual zero adjustment load and always use the actual zero adjustment load as a reference when calculating the rolling reduction. By the way, it is general that the zero load is basically aimed at the right and left difference of zero. However, when a significant left and right difference is generated in the actual zero load, as described above, the right and left difference is also included. It is possible to handle this by always using the actual zero adjustment load including this left-right difference as a reference when calculating the rolling reduction, but it is not possible to use the actual zero adjustment load when calculating the rolling reduction It is necessary to correct not only the right and left difference of the roll deformation amount as shown in FIG. 1 but also the left and right difference of the deformation amount of the housing / press-down system caused by the right and left difference of the reinforcing roll reaction force.

FIG. 3 shows a data collection procedure for determining the deformation characteristics of a four-high rolling mill in the sheet rolling method according to the first aspect of the present invention. The deformation characteristic referred to herein is a so-called mill stretch, which means a change in a gap between upper and lower work rolls as a result of elastic deformation of a rolling mill when a rolling load is applied. When grasping this mill stretch, the deformation of the roll system can be obtained with high accuracy by the existing method, but the deformation characteristics of the housing and rolling system other than the roll system include many elastic contact surfaces, so it is theoretically possible. It is generally difficult to grasp accurately. Therefore, in Japanese Patent Publication No. 4-74084, a kiss roll tightening test is performed in advance before the rolling operation, and the amount of deformation of the roll system is calculated and separated from the amount of deformation for each tightening load at that time, and separated.
A method for separating the deformation characteristics of the housing and the screw-down system is disclosed. Japanese Patent Application Laid-Open No. Hei 6-182418 discloses a method for independently separating the deformation characteristics of the left and right housing and the screw-down system. However, in the method of Japanese Patent Application Laid-Open No. 6-182418, since the effect of the thrust force acting between the rolls is not considered at all, sufficient accuracy is obtained when the thrust force between the rolls becomes a certain value or more. There was no problem. Claim 1 of the present invention is a technique capable of solving this problem, as shown in FIG. 3, when the kiss roll tightening test is carried out, the upper and lower, left and right reinforcing roll reaction forces and the upper and lower work roll thrust reaction forces are measured. I do. In general, the deformation characteristics of the housing / rolling system change with the rolling load.
In the kiss roll tightening test shown in (1), data is collected for a plurality of rolling positions and tightening load levels. Although it is better to increase the number of the rolling position levels, a practical rolling mill can obtain practical accuracy if data of about 10 to 20 points can be collected. However, at this time, a so-called mill hysteresis often occurs, which causes a difference in the tightening load between the direction in which the screw-down device is tightened and the direction in which the screw-down device is opened. In such a case, at least the tightening direction and the opening direction are different. It is preferable to collect data for one reciprocating operation and perform an operation such as averaging both measured data.

FIG. 4 shows an algorithm for calculating and extracting the deformation characteristics of the housing / press-down system independently on the left and right sides using the data collected according to the procedure of FIG.
First, the measured values of the vertical and horizontal reinforcing roll reaction forces and the thrust reaction force of the upper and lower work rolls for each rolling position condition are extracted. Next, the thrust reaction force of the upper and lower reinforcing rolls and each of the thrust reaction forces of the upper and lower reinforcing rolls are calculated in the same manner as in the case of the above-described rolling zero point adjustment, from the equilibrium condition formula of the force in the roll axis direction and the equilibrium condition formula of the moment acting on the reinforcing roll and the work roll. The left-right difference between the thrust force and the linear load distribution acting between the rolls is calculated. If the load distribution between these rolls is obtained, the flexural deformation and the flat deformation of the reinforcing roll and the work roll can be calculated including the left-right difference by the method disclosed in Japanese Patent Publication No. 4-74084, etc. It is possible to calculate the displacement that occurs at the fulcrum position of the reinforcing roll as a result of these deformations. Finally, since the deformation amount of the entire mill is evaluated based on the change in the rolling position, the deformation amount of the roll system at the position of the rolling fulcrum is subtracted therefrom, and the deformation characteristics of the housing / rolling system are independently calculated left and right. By performing the roll deformation calculation based on the accurate identification of the inter-roll thrust force, it is possible to accurately grasp the deformation characteristics of the housing / press-down system, including the left-right difference. When this method is applied to a rolling mill in which the thrust force between rolls is considerably large, a significant difference occurs in the reaction force between the upper and lower reinforcement rolls, and the effect of the difference in the reaction force between the upper and lower reinforcement rolls on the deformation characteristics of the housing / press-down system. However, in such a case, various vertical roll reaction force differences are generated by, for example, giving a small cross angle between the rolls, and the housing / roll-down system is made in accordance with the above procedure. By identifying the deformation characteristics of the rolling mill and arranging this as a function of the vertical reaction force difference, it is possible to accurately identify the deformation characteristics of the rolling mill.

FIG. 5 shows an algorithm of a preferred embodiment of the rolling position control of the pair-cross type four-high rolling mill in the sheet rolling method according to claims 2 and 3 of the present invention. First, the reinforcing roll reaction force acting on the lowering fulcrum position of the upper and lower reinforcing rolls during rolling and the thrust reaction force of the upper and lower work rolls are measured. Next, the thrust reaction force of the reinforcing roll, the thrust force acting between the reinforcing roll and the work roll, and the linear load distribution are obtained from the equilibrium conditional expression of the axial force acting on the reinforcing roll and the work roll and the equilibrium conditional expression of the moment. And the left-right difference between the thrust force acting between the work roll and the rolled material and the linear load distribution. In this example, since the off-center amount of the rolled material is known as a value measured by a sensor or the like, the above-described calculation procedure can be executed in the same manner as in the case of the zero reduction adjustment in FIG. Using the load distribution between the rolls and the rolled material to the work roll obtained as a result of this calculation, the bending deformation and the flat deformation of the reinforcement roll and the work roll are calculated including the left-right difference, and further as a function of the reinforcement roll reaction force. Calculate the deformation of the housing / press-down system and calculate the current thickness distribution. At this time, it is preferable to use the deformation characteristics of the housing / press-down system identified by the method shown in FIG. Then, a target value of the rolling position operation amount for achieving the target value is calculated from the thickness distribution predetermined as a target in the rolling operation and the estimated value of the calculated current thickness distribution result. Then, the rolling position control is performed based on the target value. By this method, it is possible to accurately and without time delay asymmetry of the thickness distribution occurring immediately below the roll bite, particularly in a hot strip finish rolling where quick and appropriate rolling position control is required. A large effect can be obtained on the stability of threading at the time of threading and tail end threading. In addition, the information obtained from the rolling mill alone as described above is used to detect the input / output side of the rolling mill such as a meandering sensor and a looper load cell, and further, in the case of tandem rolling, other rolling mills on the upstream and downstream sides. It is also effective to perform comprehensive control by combining information from the system. FIG. 5 shows a control method in consideration of the thrust force acting between the work roll and the rolled material for the pair cross rolling mill. However, in the case of a normal four-high rolling mill other than the pair cross rolling mill, as described above, Since the thrust force between the work roll and the rolled material is so small that it can be ignored, the same control as in FIG. 5 can be performed by using only the information on one of the upper and lower rolls, and it is possible to use all the upper and lower measured values. If possible, the number of unknowns will be reduced by one. Therefore, it is possible to obtain a more accurate solution by obtaining the least squares solution using all the equilibrium conditional expressions for the force in the roll axis direction and the equilibrium conditional expressions for the moment. Become.

FIG. 6 shows a plate rolling mill according to claim 4 of the present invention.
1 shows a preferred embodiment of a four-high rolling mill having a roll shift mechanism. Work rolls 1a, 1b, reinforcing rolls 2a, 2
b, a reinforcing roll reaction force measuring device, that is, load cells 6a, 6b, 6c, and 6d, are provided at left and right rolling fulcrum positions of the upper and lower reinforcing rolls, respectively. The work rolls 1a, 1b are connected to the work roll axial shift devices 8a, 8b, and are located between the chocks 4b, 4d for supporting the thrust reaction force acting on the work rolls and the work roll shift devices 8a, 8b. Is a load cell 7 for measuring a thrust reaction force acting on a work roll.
a and 7b are provided. By using a four-high rolling mill having such a configuration, the vertical and horizontal reinforcing roll reaction forces and all the rolls other than the reinforcing rolls, that is, FIG.
In the case of the example, the thrust reaction force acting on the upper and lower work rolls can be measured, and the plate rolling method according to claims 1 to 3 of the present invention can be performed. When the actuator of the work roll shift device is a hydraulic cylinder, the work roll thrust reaction force measuring device is a pressure measuring device that measures the pressure in the hydraulic cylinder or a hydraulic pipe directly connected to the hydraulic cylinder instead of the load cells 7a and 7b. It may be substituted. In addition, when the work roll shift device is not provided, as described above, the load acting on the thrust reaction force measuring device provided in the work roll roll chock and the keeper plate that restrains the work roll chock in the roll axis direction is measured. What is necessary is just to employ | adopt the apparatus which performs.

FIG. 7 shows a plate rolling mill according to claim 5 of the present invention.
A preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism is shown. In FIG. 7, in addition to the plate rolling mill of FIG.
At least the measured values from the load cells 6a to 6d for measuring the reaction force of the upper and lower and left and right reinforcing rolls and the measured values from the load cells 7a and 7b for measuring the thrust reaction force of the upper and lower work rolls are used as input data. The arithmetic unit 10 has the asymmetry of the roll center distribution of the load acting on the mill center with respect to the mill center or the asymmetry of the roll center distribution of the load acting between the upper and lower work rolls on the mill center as output data 11. . By using a plate rolling mill having such a configuration, the present invention claims 1 to 1.
The plate rolling method 3 can be performed. In addition, although a process computer is normally used as the arithmetic device 10, this arithmetic device does not need to be an independent computer, and among computers having more comprehensive functions,
If there is a part of the program that performs the functions described above,
A part of the program and the computer are regarded as the arithmetic device 10.

FIG. 8 shows a sheet rolling mill according to claim 6 of the present invention.
A preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism is shown. 8, the work roll chocks 4a, 4b, 4c, and 4d have a structure that supports only a radial load acting in the vertical direction or the rolling direction, and the thrust force in the roll axis direction is a special thrust. It is structured to be supported by the reaction force supporting chocks 13a and 13b. Generally, a roll bending force is applied to the work roll chock, and a frictional force acts in the roll axis direction between the load application portions 12a, 12b of the roll bending device and the work roll chocks 4a, 4b, and the thrust reaction is generated. This is a disturbance to the thrust reaction force measurement value by the force measurement load cells 7a and 7b. However, the frictional force acting in the roll axis direction described above can be minimized by providing a structure in which the work roll chock supporting the roll bending force does not receive the thrust force as in the embodiment of FIG. Thus, the measurement accuracy of the thrust reaction force is dramatically improved. By the way, when a work roll shift mechanism is provided as shown in FIG.
Normally, the working roll shift direction is opposite, so that the radial load supporting chocks 4a, 4b, 4c, 4d are preferably restrained by a keeper plate (not shown) so as not to move in the axial direction.

In FIG. 8, the load cells 7a and 7b for measuring the thrust reaction force are provided in the work roll shift devices 8a and 8b. However, in the case of a rolling mill having no work roll shift device, the thrust reaction force support load cells are used. Chocks 13a, 13
b is constrained in the roll axis direction by a keeper plate or the like via the thrust reaction force measurement load cells 7a and 7b. further,
In the case of a rolling mill without a work roll shift device, the amount of movement in the roll axis direction is extremely small, so as described above, only one of the upper and lower work roll chock is used for supporting the radial load and the thrust reaction force supporting chock. The same effect can be obtained by simply separating the two.

FIG. 9 shows a plate rolling mill according to claim 7 of the present invention.
A preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism is shown. The plate rolling mill shown in FIG. 9 has a work roll bending device of a hydraulic servo system, and has a function of superimposing a vibration component of a frequency of 10 Hz on a predetermined work roll bending force. As described above, when such a plate rolling mill is used to measure the thrust reaction force, the measurement accuracy of the thrust reaction force can be increased by superimposing a vibration component on a predetermined roll bending force.

FIG. 10 shows a preferred embodiment in the case of a four-high rolling mill according to claim 8 of the present invention. FIG.
In the zeroth embodiment, thrust bearing mechanisms 15a, 15b having a degree of freedom in the roll axis direction are provided between the load application parts 12a, 12b of the roll bending device and the upper work roll chocks 4a, 4b. With such a configuration, even when the roll bending force is acting, the load applying portion 15 of the roll bending device can be used.
The frictional force acting between the a and 15b and the work roll chock in the roll axis direction is negligibly small, and the work roll thrust reaction force can be accurately measured.
The slide bearing mechanism has a limit in its operation range. At the operation limit position, the effect of reducing the frictional force in the direction exceeding the operation limit is lost. For example, when no load is applied by a spring mechanism or the like, the slide bearing mechanism returns to the center position in the operation range. It is preferable to provide such a mechanism and periodically perform a kiss roll tightening operation to release the roll bending force and return the slide bearing mechanism to the center position of the operation range. However, the restoring force of this spring mechanism must be sufficiently weaker than the thrust force acting on the roll, and must be stronger than the operating resistance of the slide bearing at no load.
Further, in FIG. 10, the slide bearing mechanisms 15a and 15b are provided on the upper chock side and the roll bending devices 12a and 12b are provided on the lower chock side. It may be provided on the load side. further,
Although the plate rolling mill in FIG. 10 does not have the function of shifting the work roll in the axial direction, the slide bearing mechanism can be applied even when the work roll shift mechanism is provided. However, when the work roll position is changed using the work roll shift device, the slide bearing mechanism may reach the operation limit position. In such a case, it is preferable to return the slide bearing mechanism to the center position of the operation range by performing an operation such as releasing the work roll bending force as described above.

FIG. 11 shows a preferred embodiment in the case of a four-high rolling mill according to the ninth aspect of the present invention. FIG.
In 1, the load roll portions of the work roll bending devices 12 a and 12 b and the work roll chock 4 that abuts against the load load portion.
The liquid is sealed between c and 4d in a closed space at least partially covered with a thin outer skin having an elastic deformation resistance against out-of-plane deformation of 5% or less of the maximum value of the roll bending force,
The load transmitting portions 16a, 1 configured so that the liquid film is not broken even with respect to the maximum value of the roll bending force.
6b. FIG. 12 or FIG. 13 shows a specific example of the load transmitting unit. In the example of FIG. 12, the roll chock 4c and the metal plate 19 are provided above the lower work roll chock 4c.
A load transmitting portion 16a is provided in which a liquid is sealed in a space surrounded by the thin outer shell 17 and the load transmitting portion 16a. As a material of the thin skin 17, for example, a high-strength polymer material, a composite material in which a woven fabric of carbon fibers is provided with a lining to prevent liquid outflow, or the like can be used. By adopting the outer skin having sufficient strength even with a thin wall as described above, even if the load applying part 12a of the roll bending force and the work roll chock 4c are slightly displaced in the roll axis direction, the load from the load applying part 16a is reduced. The generated shear deformation resistance, that is, the apparent coefficient of friction, can be made almost negligible. Further, as the internal liquid, a liquid having a rust-preventing effect is preferable, and for example, oils and fats, grease and the like may be used.
FIG. 13 shows another form of the load transmitting portion 16a. The load transmitting portion 16a in the example of FIG. 13 has a structure in which the liquid 18 is sealed in a bag-shaped closed space constituted by the thin outer skin 17. By adopting such a structure, it is possible to easily replace the load transmitting portion even if it deteriorates with time. By the way, the plate rolling mill in FIG. 11 does not have the function of shifting the work roll in the axial direction. However, even if it has a work roll shift mechanism, the load transmission unit of the type shown in FIG. 12 can be used. However, in this case, it is preferable to implement a mechanism and an operation for returning the operation limit position to the center similarly to the slide bearing mechanism described with reference to FIG. In FIG. 11, the roll bending devices 12a and 12b are provided on the upper work roll chock side, and the load transmitting units 16a and 1 are provided on the lower work roll chock side.
Although 6b is provided, it may be replaced upside down, or the load transmitting portion may be provided on the load loading portion side of the roll bending device.

FIG. 14 shows a preferred embodiment in the case of a four-high rolling mill according to the tenth aspect of the present invention. FIG.
In the fourth embodiment, work roll shift devices 8a and 8b for shifting the work roll in the roll axis direction are provided, and work roll chocks 4b and 4d for supporting a thrust reaction force acting on the work roll and a work roll shift. Thrust reaction force measurement load cell 7 between devices 8a and 8b
a and 7b are provided. The work roll shift device 8
A and 8b are provided with a function capable of giving, in addition to movement to a predetermined work roll position, minute shift oscillations 23a and 23b having an amplitude of 1 mm or more and a cycle of 30 seconds or less in the roll axis direction. Such a function is, for example, in the case of a work roll shift device of a hydraulic servo system, in the control device of the shift device, a signal corresponding to a predetermined swing is superimposed by a function generator on an input signal giving a target roll shift position. It can be realized by doing. At the time of collecting data of the work roll thrust reaction force using such a work roll shift device, it is preferable to apply a small shift swing of a sine wave pattern at ± 3 mm and a cycle of about 5 seconds, and to perform thrust reaction for at least one cycle. The measured force values are averaged to obtain a thrust reaction force value when the rolling method according to claims 1 to 3 is performed. By doing so, the direction of the frictional force acting between the load application parts 12a, 12b of the work roll bending device and the work roll chocks 4a, 4b is reversed, the thrust reaction force is measured, and this is averaged. This makes it possible to eliminate the influence of the frictional force. In addition, for this amplitude, an optimal value should be selected according to the mechanical accuracy of the work roll shift device. For example, when the mechanical play is larger than 6 mm, at least about ± 4 mm of swing is given. Otherwise, effective swinging of the work roll cannot be performed, and the frictional force between the load application portion of the roll bending device and the work roll chock cannot be reversed. Further, if the amplitude is too large, the rolling operation itself is affected. Therefore, it is preferable to employ a minimum amplitude at which the frictional force is reversed. The frequency of the oscillation is preferably shorter from the viewpoint of the measurement cycle of the thrust reaction force. However, if the frequency is too short, the peak value of the thrust reaction force becomes excessively large, which affects the rolling operation or causes the work roll shift. Since the load limit of the apparatus may be exceeded, in such a case, it is preferable to lengthen the swing cycle up to the required measurement cycle of the thrust reaction force.

[0062]

According to the present invention, the rolling level setting and control of the rolling mill, which has conventionally relied on the operator, can be automated, and the rolling level can be set and controlled more accurately and appropriately than before. Significantly reduces the frequency of occurrence of meandering and threading troubles, and also significantly reduces the rolled material camber and thickness wedge, so that the cost reduction and quality improvement required for rolling can be achieved at the same time. Will be possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing an algorithm of a preferred embodiment of a method for adjusting a rolling reduction zero point in the case of a four-high rolling mill in the sheet rolling method according to claim 1 of the present invention.

FIG. 2 is a schematic diagram showing left-right asymmetric components of a force in a roll axis direction and a force in a vertical direction acting on each roll of a four-high rolling mill.

FIG. 3 is a diagram showing an example of a procedure of actual machine data measurement for identifying deformation characteristics in the case of a four-high rolling mill in the sheet rolling method according to claim 1 of the present invention.

FIG. 4 is a view showing an algorithm of a preferred embodiment of a deformation characteristic calculation in the case of a four-high rolling mill in the sheet rolling method according to claim 1 of the present invention.

FIG. 5 is a diagram showing an algorithm of a preferred embodiment of a rolling position control in the case of a pair cross type four-high rolling mill in the sheet rolling method according to claims 2 and 3 of the present invention.

FIG. 6 is a view showing a preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism in the plate rolling mill according to claim 4 of the present invention.

FIG. 7 is a view showing a preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism in the plate rolling mill according to claim 5 of the present invention.

FIG. 8 is a view showing a preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism in the plate rolling mill according to claim 6 of the present invention.

FIG. 9 is a view showing a preferred embodiment in the case of a four-high rolling mill having a roll shift mechanism in the plate rolling mill according to claim 7 of the present invention.

FIG. 10 is a view showing a preferred embodiment in the case of a four-high rolling mill in the plate rolling mill according to claim 8 of the present invention.

FIG. 11 is a view showing a preferred embodiment in the case of a four-high rolling mill according to the ninth aspect of the present invention.

FIG. 12 is a view showing a specific example of a load transmitting section used in the plate rolling mill according to claim 9 of the present invention.

FIG. 13 is a view showing another specific example of the load transmitting section used in the plate rolling mill according to claim 9 of the present invention.

FIG. 14 is a view showing a preferred embodiment in the case of a four-high rolling mill according to the tenth aspect of the present invention.

[Explanation of symbols]

1a, 1b Work roll 2a, 2b Reinforcement roll 3 Rolled material 4a, 4b, 4c, 4d Work roll chock 5a, 5b, 5c, 5d Reinforcement roll chock 6a, 6b, 6c, 6d Reinforcement roll reaction force measurement Load cells 7a, 7b ... Load cells for measuring thrust reaction force 8a, 8b ... Work roll shift devices 9a, 9b ... Roll-down devices 10 ... Computing devices 11 ... Outputs of computing devices 10 12a, 12b ... Work roll bending devices 13a, 13b ... Thrust reaction devices Working roll chock for force support 14a, 14b ... Keeper plate 15a, 15b ... Slide bearing mechanism 16a, 16b ... Load transmitting part filled with liquid 17 ... Thin outer skin 18 ... Liquid 19a, 19b, 19c, 19d ... Reinforcement roll reaction force 20 ... Line load distribution between upper work roll and reinforcing roll Le between line load distribution 22 ... lower work rolls - rolls between line load distribution 23a, 23b ... small shift swinging direction

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B21B 37/00 B21B 37/00 113A (72) Inventor Taku Kawaguchi 5-3 Tokaicho, Tokai-shi, Aichi Nippon Steel Corporation Nagoya Works (72) Inventor Koji Kawakami 5-3 Tokai-cho, Tokai City, Aichi Prefecture Inside Nagoya Works, Nippon Steel Corporation

Claims (10)

[Claims] In a rolling method using a multi-stage rolling mill having four or more stages, measured values of a roll axial thrust reaction force acting on at least all rolls other than a reinforcing roll in a kiss roll tightened state, and a vertical reinforcing roll From the measured value of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position, one or both of the zero point of the rolling device and the deformation characteristics of the rolling mill are obtained, and based on this, the rolling reduction during rolling is performed. A sheet rolling method comprising performing position setting and / or control. 2. A roll axial thrust reaction force acting on all rolls other than reinforcing rolls in at least one of upper and lower roll assemblies, preferably both upper and lower roll assemblies in a rolling method using a multi-high rolling mill of four or more stages. From the measured value of the reinforcing roll and the measured value of the reaction force of the reinforcing roll acting in the rolling direction at each rolling fulcrum position of the reinforcing roll, the target value of the rolling position operation amount of the rolling mill is calculated, and the target value of the rolling position operation amount is calculated. A sheet rolling method, wherein a rolling position control is performed based on the following. 3. A roll axial thrust reaction force acting on all rolls other than reinforcing rolls in at least one of upper and lower roll assemblies, preferably both upper and lower roll assemblies in a rolling method using a multi-high rolling mill of four or more stages. From the measured value of the roll and the measured value of the reaction force of the reinforcing roll acting in the rolling direction at each rolling fulcrum position of the reinforcing roll, the asymmetry with respect to the mill center of at least the roll axial distribution of the load acting between the rolled material and the work roll Is calculated, based on the calculation result, the target value of the rolling position operation amount of the rolling mill is calculated,
A sheet rolling method, wherein a rolling position control is performed based on a target value of the rolling position operation amount. 4. A roll axial thrust reaction force measuring device acting on all rolls other than a reinforcing roll in a multi-stage plate rolling mill having four or more stages, and acting in a rolling direction at respective pressing-down fulcrum positions of upper and lower reinforcing rolls. A sheet rolling mill comprising a reinforcing roll reaction force measuring device. 5. An apparatus for measuring a thrust reaction force in a roll axial direction acting on all rolls other than a reinforcing roll in a multi-stage plate rolling mill having four or more stages, and acting in a rolling-down direction at respective rolling fulcrum positions of upper and lower reinforcing rolls. A reinforcing roll reaction force measuring device, and at least the thrust reaction force measurement value and the reinforcement roll reaction force measurement value as input data, and at least a mill center of a roll axial distribution of a load acting between a rolled material and a work roll. A calculating device for calculating the asymmetry or the asymmetry regarding the mill center of the distribution of the load acting between the upper and lower work rolls in the axial direction of the roll. 6. A roll bending device is provided on at least one set of rolls other than a reinforcing roll, and at least one of the rolls having the roll bending device has a roll chock that supports a radial load and a roll shaft. 5. The apparatus according to claim 4, wherein the thrust reaction force supporting roll chocks are separated from each other, and a device for measuring the thrust reaction force acting on the thrust reaction force supporting roll chock is provided. A sheet rolling mill as described. 7. A roll bending device is provided on at least one set of rolls other than the reinforcing roll, and the roll bending device is configured to apply a set roll bending force to the roll bending device.
The plate rolling mill according to claim 4, further comprising a mechanism capable of adding a vibration component having a frequency of 5 Hz or more. 8. A roll bending device is provided on at least one set of rolls other than the reinforcing roll, and a degree of freedom in a roll axis direction is provided between a load application portion of the roll bending device and a roll chock contacting the load application device. The plate rolling mill according to claim 4, further comprising a slide bearing mechanism having the slide bearing mechanism. 9. A roll bending device is provided on at least one set of rolls other than a reinforcing roll, and an elastic deformation against an out-of-plane deformation is provided between a load application portion of the roll bending device and a roll chock contacting the load application device. 5. The load transmitting section according to claim 4, wherein the load transmitting section has a configuration in which a liquid is sealed in a closed space at least partially covered with a thin outer skin having a resistance of 5% or less of the maximum value of the roll bending force. Plate rolling machine. 10. A mechanism for axially shifting a roll to at least one set of rolls other than a reinforcing roll, the shift mechanism having a function of giving a minute shift swing having an amplitude of 1 mm or more and a cycle of 30 seconds or less. The plate rolling mill according to claim 4, wherein the rolling is performed.