Technical field
[0001]The present invention is, cross angle identification method of identifying a roll-to-roll cross angle in a rolling mill for rolling metal plate, the cross angle identification device, and to a rolling mill having the same.
BACKGROUND
[0002]As a phenomenon as a result of passing plate trouble in hot rolling process, for example, a meandering of the steel sheet. Steel sheet (also referred to as a roll skew.) Roll between small cross rolling apparatus one of the factors that meandering there is a thrust force generated, it is difficult to measure the thrust force directly. Therefore, the thrust force generated conventionally between rolls (hereinafter, also referred to as "roll between the thrust force".) To measure the thrust reaction force detected as reaction force of the sum of, or cause the occurrence of thrust force measuring the cross angle between the rolls, to identify the thrust force between the rolls on the basis of the thrust counterforces or the cross angle, it has been proposed to carry out the meander control of the steel sheet.
[0003]For example, Patent Document 1, to measure the load of thrust counterforces and the pressing direction of the roll barrel length direction, obtains one or both of the deformation characteristics of the pressing position zero point and the rolling machine, rolling position setting during rolling run plate rolling method for rolling control is disclosed. Further, Patent Document 2 calculates a thrust force generated in the roll based on the inter-roll small cross angle measured with the distance sensor provided in the interior of the rolling mill (roll skew angle), to the thrust force controlled reduction leveling by calculating the difference between the load component of the winding due from the measured load in the pressing direction on the basis of, meander control method is disclosed. Further, Patent Document 3, in controlling the meandering of the rolled material by the driving side detects the load difference on the operating side, independently operating the pressing position of the drive side and operating side on the basis of the load difference detected, by estimating the difference load caused by the thrust during rolling, the difference between the load during rolling are separated into those caused by the thrust and due to the meandering of the rolled material, the drive side based on the difference load that these separated control method of a rolling mill operating the pressing position of the operation side is disclosed a.
CITATION
Patent Document
[0004]
Patent Document 1: Japanese Patent No. 3499107
Patent Document 2: JP 2014-4599 JP
Patent Document 3: Japanese Patent No. 4962334
Summary of the Invention
Problems that the Invention is to Solve
[0005]
　However, in the technology described in Patent Document 1, since the measurement of the thrust reaction forces of the roll other than the rolls is required, carrying out the plate-rolling method of Patent Document 1 when there is no device for measuring thrust counterforces It can not be. Further, in the technology described in Patent Document 2, seeking roll skew angle from the horizontal distance of the rolls measured by the distance sensor of an eddy current type or the like. However, the roll vibrates in the horizontal direction by the eccentricity or the cylindricity or the like machining accuracy of the roll barrel length portion, also, since the chock position in the horizontal direction varies due to impact or the like when biting at the start of rolling, the thrust force it is difficult to measure the horizontal displacement of the generator due to become roll accurately. Further, the friction coefficient of the roll, the roll roughness as the number of rolled increases from changing over time, changes from moment to moment. Therefore, it is impossible to accurately calculation of thrust force without identification of the friction coefficient only roll skew angle measurements.
[0006]
　Further, in the technique described in Patent Document 3, before rolling, the bending force was applied while driving the roll in a state in which the upper and lower rolls are not in contact, determined from the load difference between the drive side and work side generated when the estimates the difference load caused by the thrust from the thrust coefficient or skew amount. From measurements at one rotational state of the Patent Document 3, the upper and lower rolls have identified thrust coefficient or skew amount. Therefore, displacement of the zero point of the load detection device, or if the effect of the frictional resistance between the housing and the roll chock are different on the left and right, possibly asymmetrical error in the measurement value of the driving side and the measured value of the work side is there. In particular, when the load level is low as the load of bending force, such error can be a fatal error in the identification of the thrust coefficient or amount of skew. In Patent Document 3, it is impossible to identify the thrust coefficient or skew amount to be given a role COF. Furthermore, Patent Document 3, a thrust reaction force of the backup roll is then to act on the roll axis position, it does not consider a change in the point position of the thrust reaction forces. Usually, since the chock of the backup roll is supported on the pressure device or the like, the action point of the thrust reaction force is not necessarily located in the roll axis. Therefore, errors without the thrust force between the rolls determined from the load difference between the pressure direction load of the working side and the rolling direction load on the drive side, to the thrust coefficient or skew amount is calculated based on the thrust force between the rolls error It occurs.
[0007]
　The present invention has been made in view of the above problems, it is an object of the present invention, which can be identified accurately cross angle between the rolls, new and improved cross angle identification method, and to provide a cross angle identification device, and the rolling mill.
Means for Solving the Problems
[0008]
　In order to solve the above problems, according to an aspect of the present invention, there is provided a cross angle identification method of identifying a roll-to-roll cross angle of the rolling mill, rolling mill, at least one pair of work rolls and a pair of backup rolls including a four or more rolling mill comprising a plurality of rolls, during non-rolling, while the roll gap of the work rolls in an open state, between the rolls system rolls above containing upper work roll and lower a roll bending force load step of loading the roll bending force to a load between the lower roll system of rolls including work rolls, one of the at least one of the upper rolls or lower reinforcing roll, working side and a load detection step for detecting a pressing direction load applied to the pressing direction at the pressure support position of the drive side, reduction of the pressure direction load of the detected working side driving side A load difference calculation step of calculating the load difference between the direction the load, based on the load difference comprises the identification step of identifying a cross angle between the rolls, and a load detection step, the rotation of the forward rotation and reverse rotation or roll of the roll and performing one of stopping to detect the rolling direction load of the working side and the drive side in the rotational state of the respective rolls, cross angle identification method is provided.
[0009]
　A load detecting step sets the roll bending force to the load in the opened state of the roll gap at least two levels higher, and detects the pressing direction load at each level, in the identification step, the roll between the friction coefficient, or, thrust reaction of rolls it may further identify the point position of the force.
[0010]
　Further, in the load detection step, the roll bending force to the load in the opened state of the roll gap set at least three levels or more to detect the rolling direction load at each level, in the identification step, the roll between the friction coefficient and the back-up roll it may further identify the point position of the thrust reaction forces.
[0011]
　In order to solve the above problems, according to another aspect of the present invention, there is provided a cross angle identifying device for identifying the roll between the cross angle of the rolling mill, rolling mill, at least one pair of work rolls and a pair of and a backup roll, a four or more rolling mill comprising a plurality of rolls, cross angle identification device, one of the at least one of the upper rolls or lower reinforcing rolls, the working side and the driving side based on the pressing direction load applied to the pressing direction at the pressure support position, the difference between the load calculation unit for calculating a load difference between the pressing direction load and the drive side of the rolling direction load of the working side, based on the load difference, between the rolls includes a identification processing unit for identifying the cross angle, a rolling direction load and pressure direction load on the drive side of the working side that is input to differential load calculation unit, during non-rolling, the roll gap of the work rolls in an open state, One, in a state loaded with a roll bending force to a load between the lower roll system of rolls comprising a roll system inter-roll and lower work roll of the above containing upper work roll, forward and reverse rotation of the roll or implement one of the rotation and stopping of the roll, a value detected in the rotation state of the respective rolls, cross angle identification device is provided.
[0012]
　Rolling direction load on the basis of the roll bending force to the load in the opened state of the roll gap are detected by setting at least two levels above the load difference of the detected pressure direction load at each level, roll the friction coefficient between, or it may be further identified the action point of the thrust reaction forces rolls.
[0013]
　Further, the pressing direction load, based on the roll bending force to the load in the opened state of the roll gap are detected by setting at least three levels or more, the load difference of the pressing direction load detected in each level, between the rolls of friction coefficients, and may further identify the point position of the thrust reaction forces rolls.
[0014]
　Furthermore, in order to solve the above problems, according to another aspect of the present invention comprises at least a pair of work rolls and a pair of backup rolls, a four or more rolling mill comprising a plurality of rolls, working load device and for loading the roll bending force to a load between the lower roll system roles, including in the open state of the roll gap of the roll roll system inter-roll and lower work roll of the above containing upper work roll , and a cross angle identification device of the rolling mill is provided.
Effect of the invention
[0015]
　According to the present invention described above, by identifying accurately cross angle between the rolls, for example by reducing the thrust force between the rolls, it is possible to suppress the meandering and the occurrence of the camber of the rolled material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
[1] rolling mill for explaining the thrust force and the thrust reaction force generated between the rolls of at the time of rolling, which is a schematic side view and a schematic front view of a rolling mill.
[Figure 2] for explaining the thrust force and the thrust reaction force generated between the rolls in the rolling mill of the kiss roll state, shows a schematic side view and a schematic front view of a rolling mill.
[Figure 3A] A schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification, showing a state when the roll forward.
[Figure 3B] A schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification, showing a state when the roll reversal.
In [4] the rolling mill in the state of FIG. 3A and 3B, it is an explanatory diagram showing a difference between the obtained pressure direction load between when reversed and when rotated forward the lower roll.
5 is a schematic side view and a schematic front view showing an example other operating states of the state of the rolling mill during roll between cross angle identified.
In [6] rolling mill in the state of FIG. 5 is an explanatory diagram showing a difference has been rolling direction load obtained in the case of rotating the case of stopping the lower roll.
[7] and rolling mill according to a first embodiment of the present invention, is an explanatory diagram showing a configuration of a device for controlling the rolling mill.
8 is a flowchart illustrating the inter-roll cross angle identification processing according to the embodiment.
9 is an explanatory view for explaining the thrust force between the rolls which occurs during ink-bending force load on the lower roll system.
FIG. 10 is a flowchart showing the inter-roll cross angle identification processing according to the second embodiment of the present invention.
11 is a flowchart illustrating the identification process according to a third embodiment of the present invention.
It is a schematic front view showing the FIG. 12 of the 6-high mill configuration.
[Figure 13] A schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification of the intermediate rolls and backup rolls, using the bending device of the intermediate rolls, the working shows a state during identification by the intermediate roll forward reverse accompanying forward reverse roles.
[Figure 14] A schematic side view and a schematic front view showing a drive state of the rolling mill in the states of the inter-roll cross angle identification of the intermediate rolls and backup rolls, using the bending device of the intermediate rolls, all It shows the role of a stop state, a state at the time identified by the intermediate roll rotation caused by the rotation of the work rolls.
[Figure 15] A schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification of the work roll and the intermediate roll, using a bending device of the work roll, work It shows the state at the time of identification by roll forward reverse.
[Figure 16] A schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification of the work roll and the intermediate roll, using a bending device of the work roll, work It shows a state during identification by the roll stops rotating.
DESCRIPTION OF THE INVENTION
[0017]
　Reference will now be described in detail preferred embodiments of the present invention. In the specification and the drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0018]
　<1. Purpose>
　In describing in detail the cross angle identification apparatus according to an embodiment of the present invention, first, with reference to FIGS. 1 to 7, explain the purpose of identifying the cross angle between the rolls.
[0019]
　The present invention, in the rolling of the rolled material by the rolling mill, to identify the roll between cross angle occurring between the rolls, by adjusting the cross angle between the rolls based on the identification result, eliminating the thrust force generated between the rolls , no meandering and camber or meandering and camber, is intended to stably produce a very minor product. In the present invention, a pair of work rolls, having at least a pair of rolls which each work roll is supported respectively directed to the four or more stages of the mill. For 4-high rolling mill, in order to thrust force is not generated between the rolls between the work rolls and backup rolls in contact with each other, between rolls cross angle is identified. For 6-high rolling mill, in order to thrust force is not generated between the rolls, the roll between the cross angle is identified during, and between the intermediate rolls rolls between the work rolls and the intermediate rolls in contact with each other .
[0020]
　Roll between the thrust force generates a surplus moment to the roll, asymmetrical roll deformation is contribute to unstable rolling in due, for example, cause meander or camber. The inter-roll thrust force, for example, in the case of 4-high rolling mill, generated by the deviation in the roll body length direction in the work roll and the backup roll occurs. Therefore, in the present invention, to identify the roll between cross angle to generate a thrust force between the rolls, the roll between the cross angle by adjusting the roll position so that the zero, so as not to generate a thrust force between the rolls.
[0021]
　Here, the inter-roll cross angle is difficult to measure directly. Therefore, in the present invention, the pressing direction of the load (hereinafter, referred to also as "pressing direction load".) For the role by using the load detection device detects, identifies the roll between cross angle from the change in the pressing direction load. When the roll between the cross angle is not zero, the difference load between rolling direction load of the working side of the roll and the pressing direction load on the drive side is generated. Therefore, it is possible to identify the inter-roll cross angle from the difference between the load of the pressing direction load. At this time, based on the pressing direction load detected by the roll gap of the work rolls in the open state, to identify cross angle between the rolls. The reason for this is as follows.
[0022]
(The difference between the load of the pressing direction load during rolling)
　First, to describe the difference between the load of the thrust force and the pressing direction load generated during rolling, the difference load pressure direction load caused by the roll between the thrust force during rolling, the upper roll of systems and lower roll system, occurs only on the side between rolls cross angle has occurred, not almost occur on the side of the roll between the cross angle is not generated.
[0023]
　Figure 1 shows a thrust force and for explaining the thrust counterforces, schematic side view and a schematic front view of the rolling mill occurring rolling mill rolls during rolling of the rolled material S. Incidentally, as shown in FIG. 1, the following represents the working side of the roll barrel length direction WS (Work Side), the drive side DS (Drive Side).
[0024]
　Rolling machine shown in FIG. 1, a pair of work rolls having upper work roll 1 and the lower work roll 2 which, the rolls 3 and the lower work roll 2 on supporting the upper work roll 1 in the rolling direction (Z-direction) and a pair of backup rolls made of the lower backup roll 4 which supports. A plurality of rolls which constitute the rolling mill in the present invention also referred to as a roll group. In the case of 4-high rolling mill shown in FIG. 1, roll group, the upper work roll 1, the lower work roll 2, consisting of four rolls of the upper backup roll 3 and the lower backup roll 4. Mill, by rolling through the rolled material S between the work rolls, to a thickness of a predetermined thickness of the rolled material S. The rolling mill, in the pressing direction (Z-direction), a work roll 1 and the upper backup roll 3 on which is arranged on the upper side of the rolled material S (i.e., the upper roll comprising an upper work roll of the rolls load detection device 9a on detecting the rolling direction load according to a a) upper roll system system, 9b is provided. Similarly, the rolling mill consists of the lower work roll 2 and a lower backup roll 4 arranged on the lower side of the rolled material S (i.e., is a lower roll system comprising the lower work roll of the rolls ) under load detector 10a for detecting a pressing direction load applied to the lower roll system, 10b are provided. Top load detection device 9a and the lower load detector 10a detects the pressing direction load in the working side, the upper load detection device 9b and the lower load detector 10b detects the pressing direction load at the drive side.
[0025]
　Upper work roll 1, the lower work roll 2, the upper backup roll 3 and the lower rolls 4, so as to be perpendicular to the conveying direction of the rolled material S, is disposed parallel to the barrel length direction of each roll. However, the roll is slightly rotated axis parallel (Z axis) in the pressing direction, the upper work roll 1 and the upper backup roll 3, or the deviation of the barrel length direction is generated in the lower work roll 2 and a lower backup roll 4 If, between the work rolls and backup rolls, a thrust force acting on the torso length direction of the roll is generated. For example, as shown in FIG. 1, barrel length direction of displacement between the lower work roll 2 and a lower backup roll 4 is caused to roll between the cross angle occurs. At this time, the thrust force is generated between the lower work roll 2 and a lower backup roll 4, as a result, moment is generated in the lower backup roll 4. Load distribution is changed between the lower work roll 2 and a lower backup roll 4 by the moment balanced by receiving a reaction force from the housing (not shown.) Side. As a result, the load applied to the lower load detector 10b of the drive side becomes larger than the load applied to the lower load detector 10a of the working side, the difference load occurs.
[0026]
　On the other hand, receives a thrust force of the lower roll systems, thrust in between the lower work roll 2 to be rolled material S (hereinafter,. - also referred to as "roll material between the thrust force") is applied. However, this role - between materials thrust force are those caused by small roll crossing, for example, actively roll as Kurosumiru - unlike the case of setting the cross angle between the material, the roll - between materials thrust force It is alleviated by the presence of developed area and backward area in the roll bite. Therefore, the roll between the thrust force generated by the roll-to-roll cross angle of the lower roll system does not substantially affect the roll system pressure direction load on detected above the load detector 9a, by 9b. Thus, the difference between the load of the rolling direction load caused by the roll between the thrust force during rolling, of the upper roll system and a lower roll system, occurs only on the side between rolls cross angle is occurring between the rolls cross angle the side that does not occur is not almost occur.
[0027]
(The difference between the load of the pressing direction load at kiss roll state)
　Next, the difference load thrust force and the pressing direction load generated in the kiss roll state of being in contact with a pair of work rolls will be described. The kiss roll state, unlike the time of rolling, of the upper roll system and a lower roll system, roll between the thrust force generated on the side between rolls cross angle occurs, through between the upper and lower work rolls, roll between cross angle There is transferred to the side does not occur.
[0028]
　Figure 2 shows for explaining the thrust force and the thrust reaction force generated between the rolls in the rolling mill of the kiss roll state, a schematic side view and a schematic front view of a rolling mill. For example, as shown in FIG. 2, the roll between a cross angle between the lower work roll 2 and a lower backup roll 4 has occurred. At this time, the thrust force is generated between the lower work roll 2 and a lower backup roll 4, as a result, moment is generated in the lower backup roll 4. By the moment load applied to the lower load detector 10b of the drive side becomes larger than the load applied to the lower load detector 10a of the working side, the difference load occurs. On the other hand, are in contact with the lower work roll 2 and the upper work roll 1, the roll between the thrust force generated in the lower roll system, because it is due to contact between the elastic member, the lower work roll 2 and the upper work roll 1 also act between, to generate a thrust force between the upper and lower work rolls. Thus, also generated moment is in the upper work roll 1, by the moment load applied on the load detection device 9a of the work side, it becomes larger than the load applied to the load detection device 9b on the drive side, the difference load occur.
[0029]
　Thus, in the kiss roll state, between rolls thrust force generated on the side between rolls cross angle occurs, through between the upper and lower work rolls, will be transmitted to the side between rolls cross angle does not occur , different from the behavior during rolling. Therefore, in the kiss roll state, from the detection result of the load detection device, it is difficult to quantitatively identify the inter-roll cross angle occurring between the rolls.
[0030]
(The difference between the load of the pressing direction load at the roll gap open state)
　As described above, in the rolling in and kiss roll state, it is difficult to identify the cross angle between the rolls from the change in the pressing direction load. Accordingly, the inventors of these and to study the different methods performs experimental study using a small rolling mill, have found a new knowledge below. That is, in the present invention, in order not to affect the pressing direction load roll between the thrust force on the side of the roll between the cross angles as kiss roll state of the above has occurred is detected by the other side, upper roll system independently identify and lower roll system and. Therefore, apart from the upper work roll 1 and the lower work roll 2, the roll gap the open state, to detect the cross angle between the rolls. Thus, for example, there are inter-roll cross angle in upper roll system, when the roll between the thrust force moment occurs also occurs, since the upper work roll 1 and the lower work roll 2 is not in contact, the upper between rolls thrust force generated by the roll system is not transmitted to the lower roll system. Accordingly, the pressing direction load detected by the lower load detector becomes affected by the roll between the thrust force of the upper roll system is eliminated values.
[0031]
　Specific examples of the roll between the cross angle identification method according to the present invention shown in FIGS. 3A ~ 6. Figure 3A is a schematic side view and a schematic front view showing the driving states of the state of the rolling mill during the cross angle identified between rolls of a specific example of the present invention, showing a state when the roll forward. Figure 3B is a schematic side view and a schematic front view showing a drive state of the state of the rolling mill during roll between cross angle identification, showing a state when the roll reversal. Figure 4 is the rolling mill in the state of FIG. 3A and 3B, it is an explanatory diagram showing a difference has been rolling direction load obtained in the case where reversed and when rotated forward the lower roll. Figure 5 is a schematic side view and a schematic front view showing the driving states of the state of the rolling mill during the cross angle identified between rolls showing another embodiment of the present invention. 6, in the rolling mill in the state of FIG. 5 is an explanatory diagram showing a difference has been rolling direction load obtained in the case of rotating the case of stopping the lower roll.
[0032]
Between rolls cross angle identified by (a) the roll forward reverse
　as an example of the cross angle identification method between rolls according to the present invention, the roll gap of the work rolls as the open state, and if reversed and when rotated forward roll detecting the pressure direction load, there is a method of identifying a cross angle between the rolls on the basis of the difference load. In the work rolls and backup rolls of interest, if the zero roll between cross angle, the difference load between the pressing direction load detected by the working side and the pressing direction load detected by the drive side is zero. On the other hand, if the inter-roll cross angle is not zero, the moment the roll is generated, a difference in the pressing direction load detected by the drive side and the work side is generated. Further, in the time of roll forward when the roll reverse, since the direction of the moment generated in the roll is opposite, it is opposite the magnitude of the pressing direction load detected by the drive side and the working side. Therefore, based on the difference load between when rolling forward during a roll reverse, identifying cross angle between the rolls.
[0033]
　For example, as shown in FIGS. 3A and 3B, spaced from the pair of work rolls 1 and 2, the rolling mill having a pair of rolls 3 and 4 for supporting this, the upper work roll 1 and the lower work rolls 2 and, to the roll gap between the work rolls 1, 2 in the open state. Incidentally, the upper work roll 1, the working side upper work roll chock 5a, is supported driven side by the top work roll chock 5b, the lower work roll 2, the working side and the lower work roll chock 6a, driving side is supported by the lower work roll chock 6b there. The upper backup roll 3, the working side the upper roll chock 7a, the driving side is supported by the upper roll chock 7b, the lower backup roll 4, working side and the lower reinforcing roll chocks 8a, the driving side is supported by the lower roll chock 8b there. Top work roll chock 5a, 5b and the lower work roll chock 6a, the 6b, in a state in which the work rolls 1, 2 are spaced apart from each other, increase-bending force is applied by the ink-bending device (not shown.).
[0034]
　As shown in FIGS. 3A and 3B, the roll between the cross angle rotates each roll in a state occurring between the lower work roll 2 and a lower backup roll 4, the lower work roll 2 and a lower backup roll 4 thrust force is generated, moment is generated in the lower backup roll 4 between the. In the present embodiment, to detect the rolling direction load in the case where rotated forward roll if reversed (FIG. 3A) (Figure 3B). For example, reduction of when the respective time of the roll rotating forward and when the roll reverse, rotated about parallel to the pressing direction of the lower work roll by a predetermined cross angle change portion axis (Z axis), by changing the cross angle between the rolls the result of the detection of direction load shown in FIG. Figure 4 is a work in roll diameter 80mm small rolling mill, the time during roll forward and roll reverse when the 0.1 ° change to face roll between cross angle of the lower work roll on the outlet side of the drive side detects a change in difference load in the pressing direction load is one measurement result. -Bending force loaded to each work roll chock was 0.5tonf / chock.
[0035]
　Looking at the detection result, the difference load between the pressing direction load between rolling direction load of the drive side acquired during roll forward working side, compared with the front roll between the cross angle change, increases in the negative direction . On the other hand, the difference load between rolling direction load of the drive side acquired during roll reverse the working side of the rolling direction load, compared to the previous inter-roll cross angle change, increases in the positive direction. In this way, the way a manifestation of the difference load is the opposite in that during roll forward at the time and role reversal.
[0036]
　In the present invention, based on the difference load at the time of the roll reverse roll forward, identifying roll between cross angle occurring when the difference load occurs. Then, between rolls cross angle identified that by adjusting such that the zero, without occurrence of the roll between the thrust force, no meandering and camber, or it is possible to stably produce a very minor product. In the example shown in FIG. 4 has appeared difference load from before the change of the roll between the cross angle. This shift of the zero point or the like of the load detection device or housing - due to the influence of the frictional resistance or the like between the chock, presumably because asymmetrical error enters the value detected by the load detecting device. Housing - For the frictional resistance between the chocks, the frictional resistance is to affect the detection result of the act counter to the closing direction of the pressing position load detection device, when the friction coefficient is left-right difference is in the pressing direction load It can be the error of the difference load. Such errors, especially when the load level as the load of the bending force is small, can be fatal in the identification of the roll between the cross angle. In the method according to the present invention, by comparing the time of roll forward when the roll reverse be to identify the cross angle between the rolls, it is possible to exclude the influence of the disturbance, and the change amount of the difference load identification accuracy twice. Therefore it can be expected to be improved.
[0037]
(B) roll rotation stop and the roll rotation and the roll between the cross angle identified by
　As another example of the cross angle identification method between rolls according to the present invention, the open state of the roll gap of the work rolls, and when the roll is stopped rotating detect the rolling direction load of the case is, there is a method of identifying a cross angle between the rolls on the basis of the difference load. If in the above example, the rolling mill but is required to be configured to be able to forward and reverse roll method described in the present embodiment, the rolling mill is rotatable roll in only one direction It can also be applied.
[0038]
　If the role is not rotating, i.e. when the roll is stopped, the driving force by the speed component of the roll barrel length direction between rolls does not occur, the thrust force is not generated between the rolls. Therefore, the difference load pressing direction load detected while stopping the rolls by comparing the difference between the load of the pressing direction load detected by rotating the roll, the roll between the cross angle generated by the thrust force between the rolls it can be identified.
[0039]
　For example, as shown in FIG. 5, in the rolling mill having the same configuration as FIGS. 3A and 3B, and separating the upper work roll 1 and the lower work roll 2, and an open state roll gap between the work rolls 1, 2 to. Top work roll chock 5a, 5b and the lower work roll chock 6a, the 6b, in a state in which the work rolls 1, 2 are spaced apart from each other, increase-bending force is applied by the ink-bending device (not shown.).
[0040]
　As roll-to-roll cross angle between the lower work roll 2 and a lower backup roll 4 is generated, by rotating the lower work roll 2 and a lower backup roll 4, as shown in FIG. 5, the lower work roll 2 thrust force is generated between the lower backup roll 4, moment is generated in the lower backup roll 4. By the moment load applied to the lower load detector 10b of the drive side becomes larger than the load applied to the lower load detector 10a of the working side, the difference load occurs. On the other hand, when stopping the rolls, since no relative slippage of roll barrel length direction between the lower work roll 2 and a lower backup roll 4, the thrust force is not generated between the rolls. Thus, the lower load detector 10a, the 10b, the pressing direction load that is not affected by the roll between the thrust force is detected.
[0041]
　6, in the time of roll stop and roll rotation, showing the change in the difference load in the pressing direction load detected by the drive side and the working side. In this example, the predetermined roll-to-roll cross angle provided to detect the rolling direction load in a state of stopping the roll, rolling direction load by subsequently rotating the rolls between the lower work roll 2 and a lower backup roll 4 It was detected. 6, the work in the roll diameter 80mm small rolling mill, the time during roll forward and roll reverse when the 0.1 ° change to face roll between cross angle of the lower work roll on the outlet side of the drive side detects a change in difference load in the pressing direction load is one measurement result. -Bending force loaded to each work roll chock was 0.5tonf / chock. As shown in FIG. 6, the difference load when rotating the rolls is increased in the negative direction than the difference load at the roll stop. Thus, the difference load differs in that during the roll stop and roll rotation.
[0042]
　In the present invention, based on the difference load between when rolling stop and roll rotation, to identify cross angle between the rolls. Then, between rolls cross angle identified that by adjusting such that the zero, without occurrence of the roll between the thrust force, no meandering and camber, or it is possible to stably produce a very minor product. Incidentally, a difference load appearing during roll stops in the example shown in FIG. This is similar to FIG. 4, the deviation of the zero point or the like of the load detection device or housing - due to the influence of the frictional resistance or the like between the chock, presumably because the asymmetric error value detected fall by the load detection device . Such errors, especially when the load level as the load of the bending force is small, can be fatal in the identification of the roll between the cross angle. In the method according to the present invention, by comparing the time of the roll stop and roll rotation by identifying cross angle between the rolls, it is possible to exclude the influence of the disturbance.
[0043]
　The above (a), in either case of (b), for detecting the rolling direction load by the roll gap opened between the work rolls 1 and 2, the upper roll system and a lower roll system and each roll it can be identified independently between cross angle. Identification process, upper roll system, may be sequentially performed on the lower roll systems, the upper roll system and a lower roll system may be performed simultaneously.
[0044]
　As described above, according to the present invention, the open state of the roll gap between the work rolls, detects the roll between cross angle between the work roll and backup rolls. Thus, since one to have inter-roll cross angle, when the thrust force moment occurs generated between the work rolls and backup rolls also, the upper work roll and lower work rolls are not in contact, roll between the thrust force is not transmitted to the other. Thus, while the resulting calculated thrust force difference load based on the pressure direction load that eliminates the influence of the rolls, by identifying a cross angle between the rolls, is possible to more accurately identify the cross angle between the rolls it can. Then, by roll between cross angle identified is adjusted to be zero, it is possible to eliminate the occurrence of the roll between the thrust force by the roll-to-roll cross angle during rolling, without meandering and camber, or a very minor product it is possible to manufacture stably. Hereinafter, the (a), illustrating the embodiment of the present invention relates to the case of (b).
[0045]
　<2. First Embodiment>
　based on FIGS. 7 to 9, the configuration of the first rolling mill according to the embodiment and a device for controlling the rolling mill of the present invention will be described cross angle identification method between rolls . First embodiment, the shown in (a), relates to methods of identifying the roll between the cross angle by the roll forward reverse.
[0046]
　[2-1. Construction of the rolling mill]
　First, based on FIG. 7, illustrating a rolling mill according to the present embodiment, a device for controlling the rolling mill. Figure 7 is an explanatory diagram showing a rolling mill according to the present embodiment, the configuration of the device for controlling the rolling mill. Incidentally, the rolling machine shown in FIG. 7, and shows a state viewed from the work side of the roll barrel length direction.
[0047]
　Rolling machine shown in FIG. 7, a pair of work rolls 1 and 2, a rolling mill of 4 stages and a pair of backup rolls 3,4 for supporting this. Upper work roll 1 is supported by the upper work roll chock 5, the lower work roll 2 is supported by a lower work roll chock 6. Incidentally, the upper work roll chock 5 and the lower work roll chock 6, 7 are provided as well to verso side (driving side), the work on each roll 1, and supports the lower work rolls 2. Upper work roll 1 and the lower work roll 2 is rotationally driven by the driving motor 16. Further, the upper back-up roll 3 is supported by the upper roll chock 7, the lower backup roll 4 is supported by the lower roll chock 8. Upper roll chock 7 and lower reinforcing roll chocks 8 also provided as well to FIG. 7 verso side (driving side), respectively on the rolls 3 and supports the lower back-up roll 5. Upper work roll chock 5, the lower work roll chock 6, the upper roll chock 7 and lower reinforcing roll chocks 8, is held by the housing 11.
[0048]
　In the pressing direction, the pressure support position 30a between the upper roll chock 7 and the housing 11, the upper rolling direction load detection devices 9 and screw down device 18 is provided, reduction fulcrum between the lower roll chock 8 and the housing 11 the position 30b is the lower pressure direction load detection device 10 is provided. Upper pressing direction load detection device 9 and the lower pressing direction load detection device 10 is provided similarly to FIG. 7 verso side (driving side). In addition, the project blocks between the upper work roll chock 5 and the housing 11, inlet-side on-bending apparatus 13a and the exit-side on-bending device 13b is provided between the lower work roll chock 6 and the housing 11 between ink under inlet side bending device 14a and the exit-side under-bending apparatus 14b. Inlet-side on-bending apparatus 13a, the exit side on-bending apparatus 13b, the inlet side under-bending apparatus 14a and the exit-side under-bending device 14b, is similar to Figure 7 verso side (driving side) It is provided to.
[0049]
　Each-bending apparatus, applying an ink-bending force for increasing the contact load between the work rolls and backup rolls in the work roll chock. Furthermore, the rolling mill is decrease-bending device 23a for imparting decrease-bending force to reduce the contact load between the work rolls and backup rolls in the work roll chock, 23b, 24a, it may be provided with a 24b.
[0050]
　Mill, a device for controlling the rolling mill, for example, as shown in FIG. 7, having an ink-bending control device 15, a driving motor control unit 17, and a roll between the cross angle identification device 21.
[0051]
　-Bending control device 15 is a device for controlling the entry side on-bending apparatus 13a, the exit side on-bending apparatus 13b, the inlet side under-bending apparatus 14a, and the outlet side under-bending apparatus 14b . -Bending control device 15 according to this embodiment, based on an instruction from the roll between the cross angle identification device 21 to be described later, to provide an ink-bending force to the work roll chock, and controls the increase-bending device. The ink-bending control device 15, even except when performing the inter-roll cross angle identification processing according to the present embodiment, even when performing crown control or shape control of the rolled material, the increase-bending device control may be.
[0052]
　Driving motor control unit 17 controls the driving motor 16 for rotating the upper work roll 1 and the lower work roll 2. Drive motor control device 17 according to this embodiment, based on an instruction from the roll between the cross angle identification device 21 described later, and controls the drive of the upper work roll 1 and the lower work roll 2. Specifically, the driving motor control unit 17, the upper work roll 1 and the lower work roll 2 performs a rotation state switching control of the stop state, the rotational driving control of the rotational direction and rotational speed. Incidentally, the driving motor control unit 17, even except when running roll between cross angle identification processing according to the present embodiment may control the upper work roll 1 and the lower work roll 2.
[0053]
　Between rolls cross angle identification device 21, during non-rolling, on the basis of the detection result of the working side and on which are provided respectively on the driving side pressing direction load detection device 9 or the lower pressing direction load detection device 10, detects a rolling direction load identifying the side of the work roll and roll-to-roll cross angle that exists between the rolls. Between rolls cross angle identification device 21, between a roll system on having upper work roll 1 and the upper back-up roll, for the lower roll system composed of the lower work roll 2 and a lower backup roll 4, respectively the work rolls and backup rolls to identify independently cross angle between the roles that are occurring in.
[0054]
　Between rolls cross angle identification device 21, identified target to the side of the rolling direction load detection upper difference load calculating section 19 and a lower difference load calculates a difference load pressure direction load of the detected working side and the driving side by the device having an arithmetic unit 20, and a identification processing unit 22 to identify the cross angle between the rolls. Upon acquisition of the rolling direction load, roll between cross angle identification device 21, the ink-bending control device 15, loaded with a predetermined increase-bending force to act a predetermined force between the work rolls and backup rolls an instruction to perform. Moreover, inter-roll cross angle identification device 21, to the screw down device 18, an instruction to adjust the distance between the upper work roll 1 and the lower work roll 2 to the roll gap opened. Moreover, inter-roll cross angle identification device 21, instructs the work roll drive state driving motor control unit 17 when detecting a pressing direction load, thereby controlling the driving state of the working rolls. For example, in the present embodiment, for detecting the rolling direction load on the reverse rotation and forward rotation of the work roll, the roll between the cross angle identification device 21 forward the work rolls with respect to the driving motor control device 17, and outputs an instruction to reverse. The roll bending force load processing is performed by the identification processing unit 22.
[0055]
　When rolling direction load of the working side and the driving side by the pressing direction load detection device is detected, the upper difference load computing unit 19 for upper roll system, the difference load by the lower difference load computing unit 20 for lower roll system operation It is. Identification processing unit 22, based on the difference load input from the upper differential load calculation unit 19 or the lower difference load calculating unit 20, to identify the cross angle between the rolls. Between rolls cross angle identification device 21, when the roll between the cross angle is not zero, the cross angle between the identified roles to zero, the work roll chock or housing side of the shim, the adjustment of the liner or the like performed. Alternatively, if having a roll cross angle adjusting device or the like, between rolls cross angle, which is identified as a zero, instructs the controller the angle adjustment by roll cross angle adjusting device. A detailed description of the role between the cross angle identification process will be described later.
[0056]
　[2-2. Between rolls cross angle identification processing]
　Based on FIGS. 8 and 9, illustrating a roll-to-roll cross angle identification processing according to the present embodiment. Incidentally, FIG. 8 is a flowchart illustrating the inter-roll cross angle identification processing according to the present embodiment. Figure 9 is an explanatory view illustrating a roll-to-roll thrust force generated during load-bending force to the lower roll system. In the following, a description is given of a case of identifying a roll-to-roll cross angle of the lower roll systems, the same applies to the case of identifying a roll-to-roll cross angle of the upper roll system.
[0057]
(Default: S100 ~ S102)
　In performing inter-roll cross angle identification process, first, inter-roll cross angle identification device 21, the ink-bending control device 15, predetermined increase-bending force by-bending device the instructed to load the work roll chock (S100). -Bending control device 15 controls each-bending apparatus based on the instruction, the load on the work roll chock predetermined increase-bending force.
[0058]
　Moreover, inter-roll cross angle identification device 21, to the screw down device 18, instructs the roll gap between the work rolls such that the open state, to adjust the distance between the upper work roll 1 and the lower work roll 2 (S102). Thus, the reduction direction load a detectable state. Note that the steps S100 and step S102, both the may be performed first.
[0059]
(Pressing direction load obtaining a differential load calculation: S104 ~ S114)
　and then calculates the acquisition and the difference load pressure direction load required to identify the cross angle between the rolls. In the present embodiment, at the time of roll forward rotation and the time of roll reverse, to detect the pressing direction load of the work side and drive side. Here, the coefficient n representing the rotation state of the rolls, the time the roll forward 1 to the time the roll reversal and 2.
[0060]
　First, to detect the pressing direction load during the roll forward. Between rolls cross angle identification device 21, the coefficient n as 1 (S104), sets the rotational speed and rotational direction of the work roll as roll rotation condition (S106). The inter-roll cross angle identification device 21, to the driving motor control unit 17, and outputs the rotational speed and rotational direction of the work roll set, to rotate the work rolls in the roll rotation condition (S108). When the work rolls are rotated, to detect the rolling direction load of the work side and drive side of the roll system is the identification target by the load detection device, it calculates the difference load by the difference load computing unit (S110). Difference load during obtained rolled forward is input to the inter-roll cross angle identification device 21. Then, 1 is added to the coefficient n (S112).
[0061]
　Then, the roll between the cross angle identification device 21 determines whether the coefficient n is 2 (S114). The case coefficient n is 2, is a case of detecting the rolling direction load during the roll reversal. That is, in step S114, it is determined whether to execute processing for detecting the rolling direction load during the roll reversal. When the coefficient n is 2, the roll between the cross angle identification device 21 returns to step S106, the time roll reverse, executes the processing of steps S106 ~ S110. Since such processing is the same as when the roll forward, the description thereof is omitted. Then, the difference between the load at the time of the roll reversal is obtained, is input to the inter-roll cross angle identification device 21, further one is added to the coefficient n (S112). Therefore, when the difference load at the time of roll forward and roll reversal is obtained, the coefficient n has a 3.
[0062]
　Then, in the determination of the coefficient n in step S114, when the coefficient n is 2 is not satisfied, i.e., when the time rolls forward and difference load during the roll reversal is obtained, inter-roll cross angle identification device 21 performs the process of step S116.
[0063]
(Inter-roll cross angle identified: S116)
　roll between cross angle identification device 21, based on the difference between load at the roll rotating forward and when the roll reverse, identifying cross angle between the rolls (S116). Hereinafter, based on FIG. 9, illustrating the identification of the roll between the cross angle. Here, a case will be described of identifying roll between cross angle of the lower roll system. Incidentally, the identification between the upper roll system of the roll cross angle also may be performed in the same manner.
[0064]
Relationship acquisition of the difference load and roll between the thrust force of (A) reduction direction load
　in Figure 9, showing a relationship diagram between rolls thrust force generated when was loaded-bending force to the work roll chock in the lower roll system . Working under roll system Roll - thrust T between the rolls roll WB B and, load difference P of the pressing direction df B relationship with is expressed by the following formula (1). Here, D W B is lower work rolls diameter, D B B under rolls diameter, h B B is the point position of the thrust reaction forces of the lower rolls, a B B is the distance between the supports of the lower roll system . Formula (1), as described in Patent Document 1, the following formula (1-1), the equilibrium condition of the moments of the lower work rolls and the lower rolls of the formula (1-2) It is derived. In this case, the thrust forces T acting between the upper work roll and the lower work roll WW , the roll body length direction of the contact area between the upper work roll and the lower work roll length l WW , linear load distribution between the upper and lower work rolls the difference p of the working side and the driving side Df WWBecomes zero since the roll gap between the work rolls is in the open state. Then, the difference between the working side of the line load amount between the lower work roll and the lower backup roll is unknown drive side p df WB B and the roll body length direction length l of the contact area of the inter-lower work rolls and the lower rolls WB B by the erase the equation (1-1) and (1-2), the following equation (1) is obtained.
[0065]
[Number 1]

[0066]
　Incidentally, a thrust reaction force acting point position h of the lower backup roll B B , as shown in FIG. 9, be the point position when regarded a thrust reaction force acting on the lower roll system rolls the concentrated load , when the direction away from the rolled material and the positive in the vertical direction is defined as the distance from the axis of the rolls. Again, the thrust forces T acting between the lower work roll and the lower backup roll B B and the aforementioned thrust counterforces T WB B so balance the axial forces, T B B = T WB B holds true . Such reduction device when roll chock is a load of pressing directions is acting (hereinafter, also referred to as "pressure system".) Since it is supported by the thrust reaction force acting on the rolls, only the axis of the rolls It is likely to be supported by the pressure system not. In the present invention, in the vertical direction, the thrust reaction force acting on the backup rolls is the distance between the position of the axial center position and backup rolls acting, defined as the point position of the thrust reaction forces rolls. This makes it possible to accurately calculate the thrust force between the rolls from the load difference pressing direction, as a result, it is possible to accurately identify the cross angle between the rolls. For even working point position of the thrust reaction forces rolls of upper roll system, it can be defined as the action point of the thrust reaction forces of rolls of the lower roll system.
[0067]
　In general, the thrust force T generated by the roll-to-roll cross angle between the work roll and backup rolls WB is represented by the following formula (2).
[0068]
[Number 2]

[0069]
　Here, the pressing direction load acting between the P reinforcing the work roll rolls, mu T is thrust coefficient. Thrust coefficient mu T is a coefficient representing the occurrence ratio of the roll between the thrust force with respect to the load, for example, the relative cross angle between the street and the work rolls and backup rolls represented by the formula of Patent Document 2 (2) phi, between rolls friction coefficient mu, inter-roll line load p, the Poisson's ratio of the rolls [nu, modulus G, the work roll diameter D W , reinforcing roll diameter D B expressed as a function of. Here, it is assumed that the title above formula (2) as the following formula (3).
[0070]
[Number 3]

[0071]
　In this embodiment, the roll gap between the upper work roll and lower work rolls in an open state, thinking about the occurrence of the roll between the thrust force generated when loaded with ink-bending force. Accordingly, the pressing direction load P is increase-bending force F acting per work roll chock B 2 fold (P = 2F B becomes). Than this, the equation (2) is represented by the following formula (4).
[0072]
[Formula 4]

[0073]
　Then, P load difference between the pressing direction during the roll forward of the lower roll system df1 B , between rolls thrust force T generated by the roll-to-roll cross angle between the work roll and backup rolls WB1 B , the increase-bending force F B1 Then, from the formula (1) to (4), the relational expression between the difference load and roll between the thrust force of the pressing direction load represented by the following formula (5) is obtained.
[0074]
[Formula 5]

[0075]
Here, p 1 = 2F B1 / L WB B is, L WB B shows the contact length between the lower work roll and the lower backup roll. In the formula (5), P df1 B , F B1 measured value, mu, L WB B , [nu, G, D W B , D B B , h B B when the known values, the roll between the cross is unknown it is possible to find the angle φ. Incidentally, mu, [nu, for G, and giving as a common upper roll system and a lower roll system, when the characteristic in the work rolls and backup rolls are different, or if the characteristic upper and lower roll systems are different, separate it may be given to.
[0076]
Identification between (B) roll cross angle
　in the present embodiment, by comparing the value of the difference between the load at the time when the roll reverse roll forward, identifying the role between cross. In the above formula (5), the roll but showing the relationship between the difference load and roll between the thrust force of the pressing direction load during forward rotation, similarly, the difference load and roll between the thrust force of the pressing direction load during the roll reversal and relationship is as shown in the following equation (6). Incidentally, the load difference of the pressing direction of the lower roll system during roll reverse P df2 B , the work roll and the roll between the thrust force T generated by the roll-to-roll cross angle between the rolls WB2 B , the increase-bending force F B2 and to.
[0077]
[Number 6]

[0078]
　Here, the increase-bending force at the time of roll rotation when the roll reversal is assumed to be the same value, the roll between the thrust force becomes the roll rotation during the roll reverse rotation and the magnitude is the same code different values . Than this, the following equation (7) is obtained.
[0079]
[Number 7]

[0080]
　Then, the equation (5), taking the difference of Equation (6) and substituting into the equation (7), the following equation (8) is obtained.
[0081]
[Number 8]

[0082]
　As described above, by comparing the difference value load in a time of roll forward rotation time and the roll reverse, allows identification of the roll between the cross angle between the work roll and backup rolls. Since using the relative change in the difference load between when rolling forward when the roll reverses identifying cross angle between the rolls, it is possible eliminate the effect of disturbances, such as the zero point of the measured load is shifted, Further, since the large change in the difference load is effective in the case-bending force is small.
[0083]
　Referring back to FIG. 8, when the inter-roll cross angle by the above operation is identified in step S116, inter-roll cross angle identification device 21 based on the identification result of the inter-roll cross, roll between the cross angle to zero so that, the work roll chock or housing side of the shim, the adjustment of the liner or the like performed. Alternatively, if having a roll cross angle adjusting device or the like, the roll between the cross angle identification device 21, between rolls cross angle, which is identified as a zero, performing the angular adjustment relative to the roll cross angle adjusting device or the like and outputs an instruction. This eliminates the cross angle between the rolls, it can be eliminated asymmetrical deformation due to the thrust force between the rolls. As a result, no meandering and camber, or a very minor product of meandering and camber can be produced stably.
[0084]
　<3. Second Embodiment>
　Next, a description will roll between the cross angle identification method according to the second embodiment of the present invention. Second embodiment, the indicated (b), the relates to a method identifying the roll between the cross angle using a load difference between the time of roll rotation stopped and roll rotation. Incidentally, an apparatus for controlling a rolling mill and the rolling mill according to the present embodiment is the same as that of the first embodiment shown in FIG. 7, a description thereof will be omitted.
[0085]
　Based on Figure 10, illustrating a roll-to-roll cross angle identification processing according to the present embodiment. Figure 10 is a flow chart showing the inter-roll cross angle identification processing according to the present embodiment. In the present embodiment, the following case is described where the identification of the roll between the cross angle of the lower roll systems, the same applies to the case of identifying a roll-to-roll cross angle of the upper roll system.
[0086]
(Default: S200 ~ S202)
　In performing inter-roll cross angle identification process, first, inter-roll cross angle identification device 21, the ink-bending control device 15, predetermined increase-bending force by-bending device a an instruction to load the work roll chock (S200). -Bending control device 15 controls each-bending apparatus based on the instruction, the load on the work roll chock predetermined increase-bending force.
[0087]
　Moreover, inter-roll cross angle identification device 21, to the screw down device 18, instructs the roll gap between the work rolls such that the open state, to adjust the distance between the upper work roll 1 and the lower work roll 2 (S202). Thus, the reduction direction load a detectable state. Note that the steps S200 and step S202, both the may be performed first. Thus, the process of step S200, S202 is performed similarly to step S100,102 in the roll between the cross angle identification process of the first embodiment.
[0088]
(Pressing direction load obtaining a differential load calculation: S204 ~ S214)
　and then calculates the acquisition and the difference load pressure direction load required to identify the cross angle between the rolls. In the present embodiment, in the time of roll stop and roll rotation, it detects a rolling direction load of the work side and drive side. Here, the coefficient n representing the rotation state of the rolls, the time the roll is stopped 0, the time the roll rotation 1.
[0089]
　First, to detect the pressing direction load during the roll rotation. Between rolls cross angle identification device 21, the coefficient n as 1 (S204), sets the rotational speed of the work rolls as roll rotation condition (S206). The inter-roll cross angle identification device 21, to the driving motor control unit 17, and outputs the rotational speed of the work roll set, to rotate the work rolls in the roll rotation condition (S208). When the work rolls are rotated, to detect the rolling direction load of the work side and drive side of the roll system is the identification target by the load detection device, the difference load is calculated by the difference load computing unit (S210). Difference load during acquired roll rotation is input to the inter-roll cross angle identification device 21. Then, 1 is subtracted from the coefficient n (S212).
[0090]
　Then, the roll between the cross angle identification device 21 determines whether the coefficient n is 0 (S214). The case coefficient n is 0, is a case of detecting the rolling direction load during the roll stop. That is, in step S214, the it is determined whether to execute processing for detecting the rolling direction load during the roll stop. When the coefficient n is 0, the roll between the cross angle identification device 21 returns to step S206, the time the roll is stopped, and executes the processing of steps S206 ~ S210. In the detection of the pressing direction load during the roll stop, the rotational speed of the work rolls to be set in step S206 is zero. Therefore, the work roll is not rotated in step S208. In this state, is detected rolling direction load between the drive-side step S210 the working side, the difference load is computed. Then, the difference between load at the roll stop is acquired, is input to the inter-roll cross angle identification device 21, an additional 1 is subtracted from the coefficient n (S212). Therefore, when the time of roll rotation and difference load during the roll stop is acquired, the coefficient n has a -1.
[0091]
　Then, in the determination of the coefficient n in step S214, the when the coefficient n is not 0 determined, i.e., when the time of roll rotation and difference load during the roll stop is acquired, inter-roll cross angle identification device 21, the process of step S216 is executed.
[0092]
(Inter-roll cross angle identified: S216)
　roll between cross angle identification device 21, based on the difference between load at the time and roll stop roll rotation, to identify cross angle between the rolls (S216). Here, based on FIG. 9, illustrating the identification of the roll between the cross angle. Here, a case will be described of identifying roll between cross angle of the lower roll system. Incidentally, the identification between the upper roll system of the roll cross angle also may be performed in the same manner.
[0093]
　In this embodiment, as in the first embodiment, first, the relationship between the difference load pressure direction load and the roll between the thrust force is obtained. This processing is the same as the calculation processing described in "(A) relationship acquisition of the difference load and roll between the thrust force of the pressing direction load" of the first embodiment, the description thereof is omitted here.
[0094]
　The relationship between the differential load and roll between the thrust force of the pressing direction load during the roll rotation is expressed by the relationship between the equation (5) the difference between the load of the rolling direction load represented by the roll between the thrust force. On the other hand, at the time the roll is stopped, it is not generated thrust force between the rolls even when the roll between the cross angle is present. From this, it holds the relationship of the following formula (9).
[0095]
[Number 9]

[0096]
　When the increase-bending force at the time of the roll stop and the roll rotation is assumed to be the same value, a relational expression between the difference load and roll between the thrust force of the pressing direction load during the roll stops, the equation (1), equation (5), the equation (9) becomes the following equation (10). Incidentally, P the pressure direction load difference at the time of the roll stop of the lower roll system df0 B , between rolls thrust force T generated by the roll-to-roll cross angle between the work roll and backup rolls WB0 B , the increase-bending force F B0 and .
[0097]
[Formula 10]

[0098]
　As described above, by comparing the difference value load in the time the roll is stopped at a roll rotation, allows identification of the roll between the cross angle between the work roll and backup rolls. To identify the roll between cross angle by using the relative change in the difference load between when rolling stop and roll rotation, it is possible to eliminate the influence of disturbances such as the zero point of the measured load is shifted. In comparison with the first embodiment, since the measurement to change the work roll rotational direction becomes unnecessary, it is possible to shorten the identification work. In the above description, the roll during the roll rotation has been described as being forward, the same effect even when the roll is reversed during the roll rotation is obtained of course.
[0099]
　Referring back to FIG. 10, the inter-roll cross angle by the above operation is identified in step S216, inter-roll cross angle identification device 21 based on the identification result of the inter-roll cross, roll between the cross angle to zero so that, the work roll chock or housing side of the shim, the adjustment of the liner or the like performed. Alternatively, if having a roll cross angle adjusting device or the like, the roll between the cross angle identification device 21, between rolls cross angle, which is identified as a zero, performing the angular adjustment relative to the roll cross angle adjusting device or the like and outputs an instruction. This eliminates the cross angle between the rolls, it can be eliminated asymmetrical deformation due to the thrust force between the rolls. As a result, no meandering and camber, or a very minor product of meandering and camber can be produced stably.
[0100]
　<4. Third Embodiment>
　Next, a description will roll between the cross angle identification method according to a third embodiment of the present invention. This embodiment, in addition to the cross angle between the rolls, but further roll between the friction coefficient, relates to a method of identifying a possible action point of the thrust reaction forces of the rolls. In this embodiment, similarly to the first and second embodiments, and the roll gap between the work rolls in the open state, in a state loaded with the ink-bending force to the work roll chock, the rotational state of the two rolls (e.g. obtaining a difference load rolling direction load in forward and reverse, or rotation and stop). At this time, by changing the increase-bending force, to obtain the difference load pressure direction load at multiple levels. Thus, not only the inter-roll cross angle, it becomes possible to identify other unknown.
[0101]
　Based on Figure 11, illustrating the identification process according to the present embodiment. Figure 11 is a flowchart illustrating the identification process according to the present embodiment. Incidentally, an apparatus for controlling a rolling mill and the rolling mill according to the present embodiment is the same as that of the first embodiment shown in FIG. 7, a description thereof will be omitted. In the present embodiment, the roll between the cross angle of the lower roll system, there will be described a case of identifying the roll between the friction coefficient, and the working point position of the thrust reaction forces of rolls, the same applies to the case where the identification with respect to the lower roll system . Further, in the present embodiment, the detection of the pressing direction load, as in the first embodiment, is performed at the time of roll forward rotation and the time of roll reverse, the present invention is not limited to such an example, the second embodiment as in, it may be carried out in the time of roll stop and roll rotation.
[0102]
(Default: S300 ~ S302)
　In performing inter-roll cross angle identification process, first, inter-roll cross angle identification device 21, to the screw down device 18, adjusting the distance between the upper work roll 1 and the lower work roll 2 an instruction to (S300). Moreover, inter-roll cross angle identification device 21, the number of levels to set the M-bending force is output to the ink-bending control device 15 (S302). The number of levels increase-bending force is set according to the number of values to be identified. For example, to identify the inter-roll cross angle and roll between the friction coefficient, when M is identified 2, and inter-roll cross angle, roll between friction coefficient and the working point position of the thrust reaction forces of the backup rolls, M is 3 become.
[0103]
(Pressing direction load obtaining a differential load calculation: S304 ~ S322)
　and then calculates the acquisition and the difference load pressure direction load required to identify the cross angle between the rolls. In the present embodiment, the ink-bending force loaded to the work roll chock by multiple levels changed, detects a rolling direction load of the work side and drive side at the time of roll forward rotation time and the roll reversal. Here, the coefficient n representing the rotation state of the rolls, the time the roll forward 1 to the time the roll reversal and 2. The coefficient m is a positive integer representing the level of increase-bending force (1 ~ M). In this embodiment M is 3.
[0104]
　First, to detect the pressing direction load at 1 level th roll forward. Between rolls cross angle identification device 21, the coefficient n as 1 (S304), the coefficient m and 1 (S306). The ink-bending control device 15, level 1 th-bending force F B of (1) to load the work roll chock (S308). Thus, the reduction direction load a detectable state. Moreover, inter-roll cross angle identification device 21 sets the rotational speed and rotational direction of the work roll as roll rotation condition (S310), the driving motor control unit 17 rotates the work rolls in the roll rotation condition (S312 ). When the work rolls are rotated, to detect the rolling direction load of the work side and drive side of the roll system is the identification target by the load detection device, it calculates the difference load by the difference load computing unit (S314). Difference load during obtained rolled forward is input to the inter-roll cross angle identification device 21. Then, 1 is added to the coefficient m (S316).
[0105]
　Then, the roll between the cross angle identification device 21, the coefficient m is equal to or greater than M (S318). If the coefficient m is greater than M is a case where the difference load rolling direction load is acquired in-bending force M levels set in step S302. That is, in step S318, the difference load rolling direction load at all levels is set is confirmed whether acquired. If the coefficient m is less than M, the process returns to step S308, the increase-bending control device 15, two levels th-bending force F B (2) were loaded on the work roll chock (S308), when the roll forward operation is performed and detection of the difference load of rolling direction load (S314).
[0106]
　Thereafter, further one is added to the coefficient m (S316), m is three. Between rolls cross angle identification device 21, since that does not meet the determination requirements at step S318, the process returns to step S308, the increase-bending control device 15, three levels th-bending force F B and (3) Then, 1 is added to the coefficient m (S316), when m is 4, since it meets the determination requirement at step S318, an inter-roll cross angle identification device 21 proceeds to step S320, the 1 to coefficient n adding (S320). The inter-roll cross angle identification device 21 determines whether the coefficient n is 2 (S322).
[0107]
　In step S322, it is determined whether to execute processing for detecting the rolling direction load during the roll reversal. When the coefficient n is 2, the roll between the cross angle identification device 21 returns to step S306, after resetting the coefficient m to 1, the time of roll reverse, executes the processing of steps S308 ~ S320. Since such processing is the same as when the roll forward, the description thereof is omitted. When the difference between the load at the time of the roll reversal is three levels acquired, further one is added to the coefficient n (S320). Therefore, when the difference load at the time of roll forward and roll reversal is obtained, the coefficient n has a 3.
[0108]
　Then, in the determination of the coefficient n in step S322, when the coefficient n is 2 is not satisfied, i.e., when the time rolls forward and difference load during the roll reversal is obtained, inter-roll cross angle identification device 21 performs the process of step S324.
[0109]
(Inter-roll cross angle identified: S324)
　roll between cross angle identification device 21, based on the difference between load at the time of roll forward and roll reverse roll between the cross angle, roll between friction coefficient and the back-up roll thrust reaction force identifying the point position (S324). Hereinafter, based on FIG. 9, the roll between the cross angle, roll between friction coefficient and the identification of the action point of the thrust reaction forces of rolls will be described. Here is described a case of identifying the values of the lower roll systems, the identification of the value of the upper roll system also may be carried out in the same manner. In the processing flow of FIG. 11, there is shown a case in which the acquisition of the differential load for-bending force of three levels (M = 3), in the following description, more generically two levels or more ( It shows the case of M ≧ 2).
[0110]
　In this embodiment, as in the first embodiment, first, the relationship between the difference load pressure direction load and the roll between the thrust force is obtained. This processing is the same as the calculation processing described in "(A) relationship acquisition of the difference load and roll between the thrust force of the pressing direction load" of the first embodiment, the description thereof is omitted here. Then, the increase-bending force M levels to be loaded at the time when the roll forward and roll reverse F B1 (1) ~ F B1 (M), F B2 (1) ~ F B2 When (M), the formula (8), the relational expression between the relative change and, between rolls thrust force generated by the roll between the cross angle between the work roll and backup rolls at the time of the time the roll forward and roll reverse at each level of the increase-bending force group can be expressed as the following equation (11) below.
[0111]
[Number 11]

[0112]
　Here, P df1 B (1) -P df2 B (1) ~ P df1 B (M) -P df2 B (M), when loaded with the ink-bending force of each level (m = 1 ~ M) roll forward when the difference load pressure direction load and when the roll reversal, T WB1 B (1) ~ T WB1 B (M) is loaded with the ink-bending force of each level (m = 1 ~ M) roll between the thrust force when, p 1 (1) ~ p 1 (M) is a roll-to-roll line load when loaded with the ink-bending force of each level (m = 1 ~ M).
[0113]
　From equation (11), if you set the increase-bending force two levels (M = 2) or more, the number of equations is 2 or more. Therefore, as the unknowns, the other roll between the cross angle, of the action point of the thrust reaction forces of the roll between the friction coefficient or the backup rolls, it is possible to set two or more, including at least one. If you set the increase-bending force three levels (M = 3) or more, the number of equations is three or more. Therefore, as the unknowns, the other roll between the cross angle, it is possible to set three or more, including the action point of the roll between the friction coefficient and thrust counterforces of rolls. Note, if you set more than three levels of increase-bending force, the number of equations relative to the number of unknowns exceeds but in this case can be solved by determining the least square solution.
[0114]
　As described above, in the present embodiment, increasing the load level-bending force, by comparing the difference value load at the time of the roll reverse roll forward, in addition to the identification of the roll between the cross angle, roll during the friction coefficient, it is possible to identify the point position of the thrust reaction forces rolls. Because be identified these values ​​change over time, it is possible to identify more accurately the roll between cross angle.
[0115]
　Referring back to FIG. 11, in step S324, by comparing the difference between load at the time of roll forward when the roll reverses the increase-bending force obtained by setting the three levels (M = 3), by the above calculation, between rolls cross angle, identifying the roll between the friction coefficient, and the working point position of the thrust reaction forces of the rolls. Between rolls cross angle identification device 21 based on the identification result of the roll between the cross, so that roll between the cross angle becomes zero, the work roll chock or housing side of the shim, the adjustment of the liner or the like performed. Alternatively, if having a roll cross angle adjusting device or the like, the roll between the cross angle identification device 21, between rolls cross angle, which is identified as a zero, performing the angular adjustment relative to the roll cross angle adjusting device or the like and outputs an instruction. This eliminates the cross angle between the rolls, it can be eliminated asymmetrical deformation due to the thrust force between the rolls. As a result, no meandering and camber, or a very minor product of meandering and camber can be produced stably.
Example 1
[0116]
　Fifth to seventh stand of the hot finish rolling mill having the structure shown in FIG. 7, with respect to reduction leveling set in consideration of the influence of the roll between the thrust force by the inter-roll cross angle, compared with the method of the conventional method and the present invention went.
[0117]
　First, in the conventional method, periodically to exchange the housing liner and chock liners were facility management as cross angle does not occur between the rolls. As a result, the timing of the exchange immediately preceding the housing liner, side thickness 1.2mm out as the material being rolled, when rolling a thin wide material width 1200 mm, with a thickness wedge and camber occurs, meandering in the sixth stand Filter by occurs.
[0118]
　On the other hand, in the method of the present invention, the roll bending force loaded to the work roll chock of the roll gap the open state during non-rolling, per the time when the roll reverse roll forward, the difference in pressure direction load of the working side and the driving side It compares the load, to identify the cross angle between the rolls. Then, based on the identification results, insert the shim or the like between the work roll chock side liner and work roll chock, it was adjusted so that the roll between the cross angle is reduced. As a result, even in the time of exchange immediately preceding the housing liner, conventional methods in side thickness 1.2mm out narrowing occurs, even when rolling a thin wide material width 1200 mm, less occurrence of thickness wedge and camber, the It could be Tsuban straight the rolled material in the rolling line.
[0119]
　As described above, in the method of the present invention does not require a thrust reaction force measuring device, it is possible to identify the cross angle between the rolls. Further, by adjusting the cross angle between the rolls based on the identification result, it eliminates the asymmetrical deformation due to roll between the thrust force generated due to the cross angle between the rolls, without meandering and camber or meandering and camber, There very minor metal plate, can be manufactured stably.
Example 2
[0120]
　The hot slab rolling mill having the structure shown in FIG. 7, with respect to reduction leveling set in consideration of the influence of the thrust force by the inter-roll cross angle, and compared with the methods of the prior art and the present invention.
[0121]
　First, in the conventional method, periodically to exchange the housing liner and chock liners were facility management as cross angle does not occur between the rolls.
[0122]
　On the other hand, in the method of the present invention, the roll gap during non-rolling the open state, to set the roll bending force of the two levels, per the time of the roll stop and roll rotation, the difference in pressure direction load of the working side and the driving side by comparing the load were identified cross angle and roll COF between the rolls. Then, based on the identification results, insert the shim or the like between the work roll chock side liner and work roll chock, it was adjusted so that the roll between the cross angle is reduced.
[0123]
　Table 1, for the present invention and the conventional method, shows the actual value of the camber generating the representative number of rolled. Of camber actual value per tip 1m of the rolled material, when viewing the rolls recombinant immediately before and housing liner replacement value immediately before, in the present invention, is suppressed to a relatively small value of 0.12 mm / m . If the conventional method with respect to this, in the timing of rolls recombinant immediately before and housing liner replacement immediately before the camber actual value as compared with the case of the present invention is increased.
[0124]
　As described above, in the apparatus of the present invention does not require a thrust reaction force measuring device, the identifying cross angle between the rolls, are also possible identification of time-varying roll between friction coefficient, identified values to by adjusting the cross angle between the rolls on the basis, it is possible to eliminate the asymmetrical deformation due to roll between the thrust force generated due to the cross angle between the rolls, without meandering and camber, or serpentine and very minor camber the metal sheet can be produced stably.
[0125]
[Table 1]

[0126]
　Having described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to such an example. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes and modifications , also such modifications are intended to fall within the technical scope of the present invention.
[0127]
　For example, in the above embodiment, when the identification of the inter-roll cross angle, had been the state gave a predetermined load to the work roll chock by-bending apparatus, the present invention is not limited to such an example. For example, a constant-bending force, while given a predetermined load between the work rolls and backup rolls by decrease-bending device, may be performed to identify the inter-roll cross angle.
[0128]
　Further, in the above embodiment, the load detection apparatus for pressing direction had to have been arranged both above and below, the present invention is not limited to such an example. Between rolls cross caused by progressive wear of the liner such as the chocks and the housing is expected to vary around the same time also the upper and lower. Therefore, when the load detection device is arranged on one vertical also performs the identification of the roll between the cross angle of the arrangement has been that side, based on the identification result, for example, the both upper and lower work roll chocks side liner work by replacing the same time a shim or the like between the roll chocks, it is possible to carry out the reduction of the roll-to-roll cross angle of the upper and lower both. From this, as in the case where the load detection device pressing direction both above and below are arranged, without meandering and camber, or serpentine and very minor metal plate camber can be produced stably.
[0129]
　Further application, in the above embodiment, a pair of work rolls, have been described rolling mill of 4 stages and a pair of backup rolls, for the present invention is not limited to this example, four or more high mill possible it is. For example, as shown in FIG. 12, it can also be applied to 6-high rolling mill intermediate rolls 41 and 42 are provided respectively between the work rolls 1, 2 and the backup rolls 3,4. Upper intermediate roll 41 is supported on the intermediate roll chocks 43a and the drive side on a work-side intermediate roll chocks 43b. Lower intermediate roll 42 is supported on the intermediate roll chocks 44b of the intermediate roll chocks 44a and the driving side of the working side.
[0130]
　For 6-high rolling mill, for example, as shown in FIGS. 13 and 14, the roll gap is opened between the roll gap and the work roll and the intermediate roll 42 between the work roll 1 and the intermediate roll 41, intermediate rolls 41, 42 by using the bending device, between the intermediate roll 41 and the backup rolls 3, and, to a load between the intermediate rolls 42 and backup rolls 4. In this case, the bending device of the work rolls 1 and 2, the extent to cancel the weight of the work roll, or working roll rotation and load to the extent that convey the intermediate rolls (load forces is not shown.) load between the working rolls and the intermediate rolls is adjusted in a state that does not act. In this state, the roll between the cross angle of the intermediate rolls 41 and backup rolls 3, and the identification of the roll between the cross angle of the intermediate rolls 42 and backup rolls 4 are performed.
[0131]
　Roll-to-roll cross angle between the intermediate roll 41 and the backup rolls 3, and the identification of the roll between the cross angle of the intermediate rolls 42 and backup rolls 4, for example, as shown in FIG. 13, is rotated forward the work rolls 1, 2 Te If the intermediate rolls 41 and 42 is rotated (FIG. 13 upper), respectively rolling direction load for the case of rotating the intermediate rolls 41 and 42 by reversing the work rolls 1, 2 (FIG. 13 bottom) detected may be identified based on the difference load. Alternatively, as shown in FIG. 14, when all of the roll is stopped (FIG. 14 upper), when rotating the intermediate rolls 41, 42 by rotating the work roll 1 and 2 (FIG. 14 bottom) and for each detecting a pressing direction load may be used to identify cross angle between the rolls on the basis of the difference load.
[0132]
　Thus, the roll between the cross angle of the intermediate rolls 41 and backup rolls 3, and, by carrying out the identification of the roll between the cross angle of the intermediate rolls 42 and backup rolls 4, intermediate rolls 41, 42 and backup rolls 3, 4 to coordinate with is done. Then, using the bending apparatus of the embodiment similarly to the work rolls 1 and 2, between the work roll 1 and the intermediate roll 41, and the load was loaded between the work rolls 2 and the intermediate roll 42, the work identifying roll between cross angle between the roll and the intermediate roll.
[0133]
　Roll-to-roll cross angle between the work roll 1 and the intermediate rolls 41, and, the identification of the roll between the cross angle between the work roll and the intermediate roll 42, for example, as shown in FIG. 15, is rotated forward the work rolls 1, 2 and if when reversed (Figure 15 top) and the work rolls 1 and 2 to detect each pressure direction load on (FIG. 15 bottom), may be identified based on the difference load. Alternatively, as shown in FIG. 16, to detect each pressure direction load for all roles and when stopped when rotating (Fig. 16 upper) and the work rolls 1 and 2 (FIG. 16 bottom), the it may be identified cross angle between the rolls based on the difference load. The roll-to-roll cross angle between the work roll 1 and the intermediate rolls 41, and, after carrying out the identification of the roll between the cross angle between the work roll and the intermediate roll 42, the work rolls 1, 2 and the intermediate roll 41, 42 it may be carried out of adjustment. Incidentally, the load distribution between the rolls with the change of the direction of the thrust force between the rolls also vary, since the figure becomes complicated when shown in FIGS. 13 to 16, is omitted from the description thereof.
[0134]
　Roll-to-roll cross angle between the intermediate roll and the rolls, and, when the identification of the roll between the cross angle between the work roll and the intermediate roll, in particular, to the backup rolls and the work rolls described in each embodiment described above for each formula, intermediate rolls and backup rolls may be derived by assuming respectively the work rolls and intermediate rolls. By thus performing the identification of the roll between the cross angle in turn, be adjusted in each roll on the basis of the inter-roll cross angle identified as in the case of 4-high rolling mill in the case of six-high rolling mill it can. As a result, no meandering and camber, or serpentine and very minor metal plate camber can be produced stably.
DESCRIPTION OF SYMBOLS
[0135]
　1 the upper work roll
　2 lower work rolls
　3 upper backup roll
　4 under rolls
　on 5a work roll chock (working
　side) 5b on the work roll chock (driving
　side) 6a under work roll chock (working
　side) 6b under work roll chock (driving
　side) on 7a roll chock (working
　side) 7b on roll chock (driving side)
　8a under roll chock (working
　side) 8b under roll chock (drive
　side) 9a on the load measuring device (working
　side) 9b on the load measuring device (drive
　side) 10a under load measuring device (working
　side) 10b under a load measuring device (drive
　side) 11 housing
　13a inlet side on-bending apparatus
　13b outlet side on-bending apparatus
　14a inlet side under the ink lease Ben Funding apparatus
　14b outlet side under-bending apparatus
　15-bending control device
　16 driving electric motor
　17 for driving motor control unit
　18 screw down device
　19 above difference load calculating section
　[subtracter] 20 lower difference load calculating section
　[subtracter] 21 roll during cross angle identification device
　23 inlet side on decrease-bending device
　23b outlet side on decrease-bending device
　24a inlet-side lower decrease-bending device
　24b exit-side lower decrease-bending device
　30a, 30b rolling support position
　41 on intermediate roll
　42 under the intermediate roll
　43a on the intermediate roll chocks (working
　side) 43 b on the intermediate roll chocks (driving
　side) 44a under the intermediate roll chocks (working
　side) 44b under the intermediate roll chocks (drive side)

The scope of the claims
[Requested item 1]
A cross angle identification method of identifying a roll-to-roll cross angle of the rolling mill,
　the rolling mill comprises at least a pair of work rolls and a pair of backup rolls, is 4 or more stages of a rolling mill comprising a plurality of rolls ,
　during non-rolling, while the roll gap of the work rolls in the open state, the load between the lower roll system roles, including between the rolls system rolls and lower the work rolls of the above containing upper side of the work roll a roll bending force load step of loading the roll bending force to the load,
　one of the at least one of the upper the rolls or the lower the rolls of, the pressing direction at the pressure support position of the work side and drive side a load detection step for detecting a pressing direction load applied,
　and the rolling direction load of the detected said working side the drive side and the rolling direction load A load difference calculation step of calculating the weight difference,
　on the basis of the load difference, and identification step of identifying a cross angle between the rolls
comprises,
　in the load detection step, the roll forward and reverse or of the roll rotation and implemented either stop, detecting the rolling direction load of the working side and the drive side in the rotational state of each of the roll, the cross angle identification method.
[Requested item 2]
　In the load detection step, the roll bending force to the load in the opened state of the roll gap set at least two levels higher, and detects the pressing direction load at each level,
　in the identification step, the roll between the friction coefficient, or the reinforcing further identifying the point position of the thrust reaction forces of the roll cross angle identification method of claim 1.
[Requested item 3]
　In the load detection step, the roll bending force to the load in the opened state of the roll gap set at least three levels or more to detect the rolling direction load at each level,
　in the identification step, the roll between the friction coefficient, and the reinforcement further identifying the point position of the thrust reaction forces of the roll cross angle identification method of claim 1.
[Requested item 4]
　A cross angle identifying device for identifying the roll between the cross angle of the rolling mill,
　the rolling mill comprises at least a pair of work rolls and a pair of backup rolls, is 4 or more stages of a rolling mill comprising a plurality of rolls ,
　the cross angle identification device,
　one of the at least one of the upper the rolls or the lower the rolls of, based on the pressing direction load applied to the pressing direction at the pressure support position of the work side and drive side, the difference load calculating unit for calculating a load difference between the rolling direction force of the rolling direction force and the driving side of the working side,
　and the identification processing unit based on said load difference to identify cross angle between the rolls,
comprising a
　said rolling direction load of the rolling direction force and the driving side of the working side that is input to the differential load calculation unit,
　during non-rolling, the roll gap of the work rolls open state And, and, in a state loaded with a roll bending force to a load between the lower roll system of rolls comprising a roll system of the work rolls of the roll and between the lower top including an upper of the work roll,
　the roll forward and reverse or implement one of the rotation and stopping of the roll, a value detected in the rotational state of each of the roll, the cross angle identification device.
[Requested item 5]
　The pressing direction load, the roll bending force to the load in the opened state of the roll gap being detected by setting at least two levels higher,
　based on the load difference of the rolling direction load detected in each level, roll during the friction coefficient or, further to identify the point position of the thrust reaction forces of the rolls, cross angle identification apparatus according to claim 4.
[Requested item 6]
　The pressing direction load, the roll bending force to the load in the opened state of the roll gap being detected by setting at least three levels or more,
　based on the load difference of the rolling direction load detected in each level, roll during the friction coefficient, and further to identify the point position of the thrust reaction forces of the rolls, cross angle identification apparatus according to claim 4.
[Requested item 7]
　And at least a pair of work rolls and a pair of backup rolls, a four or more rolling mill comprising a plurality of rolls,
　the roll system above containing upper side of the work roll in the opened state of the roll gap of the work rolls a load device for loading the roll bending force to a load between the lower roll system of rolls comprising the work rolls of the roll and between the lower,
　cross angle of any one of the preceding claims 4-6 and identification apparatus,
comprising a rolling mill.