JP3088881B2 - Method of setting reduction of hot plate rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling operation using a hot plate rolling mill having a rolling load measuring device. The present invention relates to a method for setting a rolling reduction.

[0002]

2. Description of the Related Art At present, the rolling reduction of a sheet rolling mill is basically basically set by a computer in accordance with an algorithm shown in FIG. The left and right values are basically the same. In the following description, the expression “left and right” is often used, but unless otherwise specified, this means the driving side and the working side of the rolling mill. The operation mode at this time is that the operator has changed this so that a stable threading state can be realized while observing the threading state of the rolled material. In fact, it is completely up to the operator in terms of leveling. Such an operation by an operator requires a high degree of skill,
Since it is not based on quantitative data, there is an individual difference, and since it is post-processing, it is impossible to completely prevent the occurrence of a threading accident or a wedge camber of rolled material.

[0003] The following two types of methods are usually used to adjust the zero point of the screw-down device after the roll is replaced, which is important in terms of the standard of the left-right difference in the set value. The upper and lower work rolls are contacted and tightened (kiss roll tightening) so that the output of the rolling load measuring device is the same on the left and right, and the reduction setting state at that time is set to zero. A copper rod or aluminum plate is tightened between upper and lower work rolls, and the zero point of the reduction setting is corrected from the difference in thickness between the left and right sides.

[0004] Of the above two methods, the method is very simple and clear and can be easily automated by a computer. However, since the absolute value of the output of the rolling load measuring device is used, the zero point of the rolling load measuring device is used. Optimum zero adjustment is not possible unless the output of the rolling load measuring device during the kiss roll tightening is prevented from having industrially significant disturbance. This method is performed to correct this, but this method requires time by hand, and even if the roll opening degree near the zero-point adjustment load is optimized, one by one rolling It is almost impossible to optimize the leveling for all rolling loads that take various values for each material.

[0005]

Conventionally, as described above, the leveling setting method basically relies entirely on the operator, and a scientific setting method based on quantitative data is not used. Not established. Therefore, in the present invention, first, a method for accurately adjusting the zero point of the rolling device based on the rolling load measuring device is disclosed, and further, a method for setting a rolling reduction in consideration of the asymmetry of the rolling mill itself is disclosed.

[0006]

SUMMARY OF THE INVENTION The first gist of the present invention for solving the above-mentioned problems is to provide a multi-stage hot plate rolling mill having a rolling load measuring device, a work roll, and a reinforcing roll. In the reduction setting method, the lubricating oil is supplied to the contact portion between the rolls, and while rotating the rolls, the lowering device is operated in a non-rolling state to bring the upper and lower work rolls into contact with each other, and the lowering device is further tightened. In order that the load acting between the work rolls is evenly distributed to the work side and the drive side, after performing zero adjustment of the reduction device according to the output of the rolling load measurement device, the work side and the drive side of the reduction device are adjusted. In the method of setting the rolling reduction of a hot plate rolling mill characterized by setting

The gist of the second invention is to provide a hydraulic work roll bending device, a rolling load measuring device, and a method for setting a rolling reduction of a multi-stage hot plate rolling mill having a work roll and a reinforcing roll. When the gap between the upper and lower work rolls is open at the time of non-rolling, the work roll bending device applies two or more levels of load in the direction of opening the upper and lower work roll gaps, and a pressure measuring device for the supply oil to the working cylinder of the work roll bending device Analysis of the hydraulic pressure detected by the above, the effective cross-sectional area of the working cylinder, the roll bending force calculated from the configuration and number of working cylinders, and the output of the rolling load measuring device for measuring the load of the rolling-down device Then, from the correlation between the two, calibrate the zero point or both the zero point and the sensitivity of the rolling load measuring device, With the lubricating oil supplied to the contact part, rotate the roll and operate the rolling device in a non-rolled state to bring the upper and lower work rolls into contact, further tighten the lowering device, and the load acting between the upper and lower work rolls The method according to claim 1, further comprising adjusting the zero point of the rolling-down device according to the output of the rolling load measuring device so that the working-side and the driving-side rolling device are evenly distributed. In the method of setting the reduction of the strip rolling mill,

The gist of the third invention is to provide a rolling load measuring device and a method for setting a rolling reduction of a multi-stage hot plate rolling mill having a work roll and a reinforcing roll, wherein lubricating oil is applied to a contact portion between the rolls. In the supplied state, the rolling device is operated in a non-rolling state while rotating the roll to bring the upper and lower work rolls into contact with each other, further tightening the rolling device, and at a plurality of points in the course of the process, the working side and the driving side And the output of the rolling load measuring device are sampled at the same time, the deformation characteristics of the roll system corresponding to the conditions at each time point are calculated and separated, and the working side of the resulting deformation characteristics of the housing and the rolling system is determined. A method for calculating a reduction in a hot-rolling rolling mill, wherein a difference between a reduction setting value on a working side and a reduction value on a driving side is calculated using data on asymmetry on the driving side.

FIG. 1 shows an algorithm of the rolling reduction method according to the first invention. The difference from the zero point adjustment operation of the rolling device performed in the normal operation of the hot plate rolling mill is that lubricating oil is supplied to the contact portion between the rolls. this is,
For the following reasons:

The adjustment of the zero point of the rolling-down device based on the difference between the left and right of the output of the rolling load measuring device when the kiss roll is tightened is based on the symmetry of the gap between the upper and lower working rolls based on the difference between the left and right of the output of the rolling load measuring device. Is reflected in the idea. However, even if the upper and lower work roll axes are parallel in a vertical plane including the roll axis, when the roll axis is not parallel when projected on a horizontal plane, that is, when the roll is in a roll cross state, when the roll rotates. As shown in FIG. 4, the peripheral velocity vectors do not coincide on the upper and lower work roll contact surfaces, and a relative velocity 17 along the roll axis direction occurs. This relative speed generates a thrust force in the roll axis direction, which is transmitted to the keeper plate or the reduction device through the roll chock to generate a thrust reaction force, and the thrust reaction force and the thrust force generated between the rolls are generated. As a result, a left-right difference occurs in the output of the rolling load measuring device (hereinafter simply referred to as a load cell) so as to balance the moment.

FIG. 5 is an explanatory view showing an example in which upper and lower work rolls cross each other in a four-high rolling mill having a load cell on the lower roll side. The work roll chock on the work side (WS) is such that the lower roll is on the near side of the drawing. The upper roll is roll-crossed so as to be on the other side of the paper surface, and the roll rotation direction is such that the peripheral speed vector of the upper and lower work roll contact portions is on the other side of the paper surface as shown in the side view. In this case, a thrust force 18 from the work side (WS) toward the drive side (DS) acts on the lower work roll. In the case of the example of FIG. 5, since it is assumed that only the work roll has a cross angle with respect to a direction perpendicular to the rolling direction, the relative roll cross also occurs between the reinforcing roll and the work roll. Therefore, the thrust force generated on the upper and lower work roll contact surfaces is transmitted to the reinforcing roll,
It is supported by the housing via a rolling device, a reinforcing roll chock, and a keeper plate. The thrust force as a reaction force at this time is expressed by a vector 19 or a vector 20. Therefore, the thrust force 18 generated between the upper and lower work rolls and these thrust reaction forces 19 or 20 constitute a couple and generate a moment. Will balance with the moment. In general hot plate rolling mill, the moment arm i.e. h _B or h _L distance between fulcrums a thrust force shown in Figure 5, equal to or, because a is degree slightly larger thrust force and the same degree of A load cell output left / right difference will occur.

As described above, when there is a cross between rolls, even if the gap between the upper and lower work rolls corresponding to the thickness distribution of the rolled material is symmetrical, a difference in the load cell output occurs in the kiss roll state. become. Therefore,
If the zero adjustment of the screw-down device is performed so that the output of the load cell becomes the same on the left and right while including the load left-right difference caused by the roll cross, the wrong zero adjustment is performed from the original purpose of obtaining a symmetrical thickness distribution. Will be implemented.

Since the difference between left and right is caused by the rotation of the roll, it can be avoided by tightening the kiss roll without rotating the roll. However, in order to minimize the error caused by the rolling load, it is preferable to select a load close to the rolling load used in the actual operation. Often this is not permissible due to the durability of the roll. Further, when an oil film bearing which cannot apply a large load in a mechanically stationary state is employed, even if the kiss roll is tightened with a low load, a significant error may occur in the left and right oil film thicknesses, which is not preferable. Therefore, it is customary that the kiss roll tightening at the time of zero point adjustment is performed in a roll rotating state, and the present invention is also based on this.

Usually, the roll chock is constrained by the housing window so that the cross between rolls as described above does not occur, but a gap of about 1 to 2 mm exists between the roll chock and the housing window. It is customary. This may be due to the aging of the rolling mill, but it is necessary to have a certain gap for the roll change. Although the roll cross angle that can occur in the range of such a small gap is as small as 0.1 ° or less, it has been found that the thrust force generated by the cross between rolls is considerably large even at such a roll cross angle. I have. FIG. 6 shows the relationship between the roll cross angle and the thrust coefficient (the value obtained by dividing the thrust force by the tightening load) determined by the experiment. According to the water lubrication data shown in FIG. 6, it is understood that the thrust coefficient is 0.1 or more even at the roll cross angle of 0.05 °. This means that when the tightening load is 1000 tonf, a thrust force of 100 tonf or more is generated at a cross angle of 0.05 °, which indicates that a very large moment is generated.

FIG. 6 also shows data of 0.1% emulsion lubrication and 1.0% emulsion lubrication using hot rolled lubricating oil in addition to water lubrication. In this case, the thrust coefficient decreases to about 0.02 even at a cross angle of 0.05 °. Thus, it can be seen that the thrust coefficient in the roll kiss state is significantly reduced by performing lubrication, and the left-right difference in load cell output caused by the roll cross in the kiss roll tightened state is also significantly reduced. By the way, the conventional hot rolling mill operation method is to supply lubricating oil only during rolling without using a lubricating oil in order to avoid slip between rolls in a non-rolling state, that is, when the roll is idling, but it is necessary to adjust the zero point of the rolling reduction. The point of the present invention is to supply the lubricating oil while paying attention to the lubrication of the contact portion between the rolls even when tightening the kiss roll. Zero point adjustment work by tightening the kiss roll (see FIG. 1)
The work enclosed by a dashed line is normally performed at an appropriate time during roll change or subsequent non-rolling, and a reduction setting work (indicated by a broken line in FIG. 1) performed for each rolled material. Less frequency than the enclosed work) is sufficient.

When the zero point adjustment of the screw-down device is performed by the method shown in FIG. 1, the accuracy of the load cell becomes very important. Therefore, in the second invention of the present application, the load cell is calibrated using a roll bending device as shown in the algorithm in FIG. 2, and the accuracy is compensated for. Then, according to the procedure of the first invention of the present application, the zero adjustment of the screw-down device is performed. And a method of performing the reduction setting is disclosed.

FIG. 7 shows an example of a side view of a typical hot plate rolling mill. The rolling mill shown in FIG. 7 is a four-high rolling mill, in which the work rolls 8-1 and 8-2 are supported by reinforcing rolls 9-1 and 9-2. -1, 6-2, the load cell 1 and the screw-down device 1
2 and is configured to follow the movement of the screw-down device. Also, the increment work roll bending devices 2-1 and 2-2 and 3-1 and 3-2 also have a role of a roll balance, and work rolls 8-1 through work roll chock 10-1 and 10-2. And 8-2 are pressed against the reinforcing rolls 9-1 and 9-2.

FIG. 7 also shows a roll-bending device 4-1, 4-2 and 5-1, 5-2 for applying a force in a direction opposite to the roll balance for reference. It is assumed that a roll bending force in the direction of opening the upper and lower work roll gaps is applied as a resultant force, and a decrease work roll bending device is not an essential requirement. Note that the work roll bending device shown in FIG.
The side work roll bending devices 2-1 and 2-2 include:
It is assumed that a pressure measuring device 14 for the working oil supplied to the working cylinder is provided.

FIG. 7 shows a non-rolling state in such a rolling mill.
With the upper and lower work roll gaps open as described above, a load of two or more levels is applied by the roll bending devices 2-1 and 2-2, the actual value of the oil pressure by the pressure measurement device 14, the effective sectional area of the working cylinder, and the The work roll bending force is calculated from the number, and the correspondence between the work roll bending force and the load measured by the load cell 1 is obtained as data. When the roll gap is opened, the work roll body is unloaded, and the load applied by the work roll bending device is directly transmitted to the load cell 1 except for the weight of the roll and the spindle. Therefore, the applied roll bending force and the value measured by the load cell 1 should ideally coincide except for the bias due to the weight of the roll and the spindle, and from this viewpoint, the zero point or the zero point of the load cell 1 and the sensitivity are considered. Calibrating both is the basic concept of the load cell calibration method which is a constituent feature of the second invention of the present application.

FIG. 8 shows the actual hot strip mill finish rolling mill No. An example of data obtained by the above method using six stands is shown. FIG. 8 shows five levels of roll bending force loads, and plots all data at the time of loading and unloading. In the figure, there is data with a significant difference in the output of the load cell for almost the same value of the roll bending force.This is the difference between when the load is applied and when the load is unloaded, and the hysteresis due to the frictional force between the roll chock and the housing is reduced. It is thought that it became apparent. As one of the prior arts, there is a method of adjusting the zero point of the load cell by applying a constant roll balance force. When checking the zero point of the load cell, the maximum value of the hysteresis as shown in FIG. There is a risk of zero error. On the other hand, as shown in FIG. 8, data for a plurality of load levels is collected and subjected to data processing of linearly approximating the data by, for example, the method of least squares, thereby minimizing the influence of such hysteresis. It becomes possible.

Generally, the pressure sensor of the hydraulic circuit used in the pressure measuring device 14 is much smaller and less expensive than the load cell 1, and the pressure sensor whose accuracy has been sufficiently checked is periodically replaced. Also, it is easy to introduce a plurality of sensors into the same hydraulic circuit and check the accuracy with each other, which makes it very easy to control the accuracy. Therefore, there is a great advantage that accuracy control of a load cell which is very expensive and cannot be easily replaced by using it can be performed.

In FIG. 8, the least squares approximation of the data including the gradient of the straight line is performed for the purpose of calibrating both the zero point and the sensitivity of the load cell. A linear approximation with a fixed gradient of 1 as in FIG. For example, when both the zero point and the sensitivity are calibrated, the following equation is obtained by linear approximation of the data in FIG. P _W = 1.039F-59.6 ………………… (1) P _D = 1.022F-82.9 , P _W , and P _D are the output values of the load cells on the working and drive sides, respectively, F is the roll bending force, and the unit is tonf. In the present invention, since the value of F is considered to be a sufficiently calibrated and accurate value, values obtained by evaluating the true load applied between the upper and lower work rolls on the working side and the driving side are Q _W and Q _D. , Then, from equations (1) and (2), Q
_W and Q _D are obtained from the measured values P _W and P _D by the following equations. Q _W = (P _X +59.6) /1.039 (3) Q _D = (P _D +82.9) /1.022 (4)

Since the values of Q _W and Q _D during the rolling measured and calculated in this way include the roll bending force F, the true force acting between the rolled material and the work rolls is obtained. If it is desired to estimate the load, the measured value of the roll bending force F at that time may be subtracted from the values of Q _W and Q _D. Further, instead of performing the calculations as in the equations (3) and (4), substantially the same sensitivity and bias adjustment may be electrically performed.

For the purpose of zero point calibration only, FIG.
The following relationship is obtained from the linear approximation in which the gradient is fixed to 1. P _W = F−55.1 …………………… (5) P _D = F−80.4 ………………… ( 6) Therefore, the true loads Q _W , Q including the roll bending force
_D is obtained from the measured loads P _W and P _D by the following formula. Q _W = P _W +55.1 ……………… (7) Q _D = P _D +80.4 …………………… ( 8)

In the above procedure, the weight of the roll, the spindle, etc. is not mentioned at all, but physically, between the roll bending force F and the detected value of the load cell 1, the weight of the roll, the spindle, etc. There should be a bias. However, since this value is constant unless the roll is replaced, this bias is absorbed by the load cell's own bias in accordance with the original purpose of rolling load detection, which is to detect the load acting between the upper and lower work rolls. Takes the idea. Of course, it is possible to describe the relationship between the roll bending force F and the true loads Q _W and Q _D by accurately considering the weight of the roll and the spindle, etc., but even in that case, the basics of the above procedure are the same. It is.

By the way, when the roll is replaced after the load cell is calibrated by the above-described method, the zero point of the rolling load theoretically changes by the weight difference of the rolls because the weight of the rolls differs. become. To cope with this, the load cell should be calibrated by the above-described method again immediately after the roll change. This makes it possible to maintain the same accuracy of the load cell as before the roll change.

After the load cell is calibrated in accordance with the above procedure, the rolling device is operated in a non-rolling state while rotating the rolls while lubricating oil is supplied to the contact portion between the rolls, and the upper and lower work rolls are operated. And further tighten the screw-down device, and adjust the zero point of the screw-down device according to the output of the rolling load measuring device so that the true load acting between the upper and lower work rolls is evenly distributed to the working side and the drive side. After that, by setting the pressing devices on the working side and the driving side, it becomes possible to remarkably improve the passability of the rolled plate. In addition, the calibration work of the load cell as above,
It is preferable to carry out each time the roll is changed, but if the change in the weight of the roll is very small and the aging of the load cell output is considered to be small, the frequency may be further reduced.

Even when the load cell is sufficiently calibrated as described above and the zero point adjustment of the rolling device is accurately performed, if the deformation characteristics of the rolling mill itself have asymmetry between the working side and the driving side, As a result, a leveling error occurs due to the difference between the zero-point adjustment load of the screw-down device and the actual rolling load. The solution to this problem is the third invention of the present application,
The algorithm is shown in FIG. In the present invention, a kiss roll tightening test is performed after the roll is changed and before the rolling operation is started, or in a non-rolled state such as an idle time at a break in the rolling operation. Then, at a plurality of points in the course of the process, the pressure setting positions on the working side and the driving side and the load cell output are simultaneously sampled. The data obtained as a result is obtained by setting the reduction values of the working side and the driving side to g _W and g, respectively.
_D , the output of the load cell is P _W ,
When P _D is used, it can be interpreted as a discrete expression of a functional relationship such as the following equation. g _W = g _W (P _W , P _D ) ... (9) g _D = g _D (P _W , P _D ) ………………………… …… (10)

By the way, the equations (9) and (10) require data up to a large load equivalent to the rolling load when collecting data of the rolling mill. Therefore, the kiss roll is tightened while the roll is rotating. At this time, there is a possibility that the thrust force caused by the minute cross between the rolls may cause disturbance of the load cell output. Therefore, even when collecting this data, accurate data collection can be performed only by supplying lubricating oil to the contact portion between the rolls.

Since the roll gap between the upper and lower working rolls remains zero during the contact between the upper and lower rolls, the deformation of the roll / rolling system and the housing, that is, the deformation of the entire rolling mill, That is, This amount of deformation is calculated, excluding the amount of deformation of the roll system, the work side and drive side of the housing and pressure system of the deformation amount Δ _O ^w, Δ _O ^D work side and drive side respectively applied load P _W, P _It can be expressed as the following function as a discrete function of _D. Δ _O ^w = Δ _O ^w (P _W ) ……………… (11) Δ _O ^D = Δ _O ^D (P _D ) ………………………………… … (12)

If the deformation characteristics of the working side and the drive side can be obtained independently as in the equations (11) and (12), the asymmetry of the rolling mill mainly including the asymmetry of the shape of the elastic contact surface is included. As a result, the deformation characteristics of the housing and the rolling system can be estimated based on the actual measurement data. Based on the deformation characteristics of the housing and the rolling system in the equations (11) and (12), the upper and lower work rolls by the rolling load during rolling are obtained. Calculate the amount of change between gaps, that is, mill stretch,
What is necessary is just to determine the rolling reduction values on the working side and the driving side so that a predetermined plate thickness distribution is obtained.

The above-described operation is performed every time the reinforcing roll is replaced, and the deformation characteristics of the housing and the pressing system are extracted, whereby the deformation of the elastic contact surface between the reinforcing roll chock and the pressing screw or the liner due to the changing of the roll is performed. A change in characteristics can be immediately detected and compensated.

[0033]

【Example】

Example 1 Using a four-high rolling mill having a working roll diameter of 800 mm, a reinforcing roll diameter of 1600 mm, and a distance between reduction fulcrums of 2940 mm as shown in FIG. In this state, the lowering device was operated to bring the upper and lower work rolls into contact with each other, and the lowering device was further tightened.The lowering device was adjusted so that the load acting between the upper and lower work rolls was equal to 500 ton on the working side and the drive side. The position was taken as the zero point of the screw down device. When rolling was started on the basis of this zero point, all rolled materials were considerably bent. Then, when a 1.0% emulsion of hot lubricating oil was supplied in a non-rolled state and the kiss roll was tightened until the load cell load became 500 tonf on the left and right, a difference of 87 tonf was generated between the load cell on the left and right. Next, in order to eliminate this load difference, the rolling device was operated again so that the load cell load became 500 tonf on both the left and right sides, and that point was reset as the zero point of the rolling device. In the rolling operation after the resetting of the zero point, the bending of the rolled material was almost completely eliminated.

The fulcrum distance a = 2940 mm shown in FIG.
When a moment arm h _B = 1600 mm when the thrust force f is received by the keeper plate of the reinforcing roll is used, 0.5P _df · a = f · h _B ... ... (13) holds. Accordingly, the left-right difference P _df = 87 ton of the load cell load between the initial water lubrication state and the state in which the lubricating oil is supplied.
Is equivalent to 80 tonf when converted to a change in thrust force,
It is estimated that the load cell load was disturbed due to the thrust force. As described above, it is understood that it is important to perform the kiss roll tightening test for setting the zero point of the screw-down device while supplying the lubricating oil.

Example 2 FIG. 10 shows the actual hot strip mill finish rolling mill No. 7
In the stand (four-high rolling mill), data on the relationship between the roll bending force and the load cell is collected in accordance with the load cell calibration method shown in FIG. FIG.
Now, the gradient is set to 1 only for the purpose of zero adjustment of the load cell.
The true loads Q _W and Q _D are calculated by the following equations from these approximate straight lines. Q _W = P _W +90.5 (14) Q _D = P _D +59.7 (15) Q _D = P _D +59.7

On the other hand, FIG. 11 shows data collected after six months from the same rolling mill, from which the following correction formula is obtained. Q _W = P _W +59.6 (16) Q _D = P _D +131.1 (17)

Therefore, when the corrections of the equations (14) to (17) are not performed, the difference between the rolling load on the working side and the rolling load on the working side is (90.5-59.7)-(59.6) within six months. -13
1.1) = 102.3 tonf change.
It is clear that if the zero adjustment of the screw-down device is performed based on the load cell output while keeping such a change and the leveling setting is performed, it will have a serious adverse effect on the threading work. Turns out to be very important.

Example 3 FIG. 12 is an example of the relationship between the set value obtained by the kiss roll tightening test and the measured load. FIG. 13 is a diagram showing the deformation of the roll system from the data of FIG. This is an extraction of the deformation characteristics of the rolling system. In FIG. 13, the vertical axis is twice the measured load in order to associate the deformation characteristics of the working side and the drive side housing and the rolling system with the rolling load defined as the sum of the outputs of the left and right load cells. And expressed as rolling load. According to the data of FIG. 13, the rolling load is 1000 to
The left-right difference (working side-driving side) of the amount of deformation of the housing / pressing system when nf changes is -58 μm, and there is a non-negligible left / right difference in the deformation characteristics of the housing / pressing system.
It can be seen that it is important to correct this based on the data in FIG.

[0039]

By using the method for setting the rolling reduction of a sheet rolling mill according to the present invention, the optimum leveling setting can always be realized.
As a result, there is almost no accident at the time of passing the board,
The working rate and yield can be greatly improved, and defects in dimensional accuracy, such as a thickness wedge of a rolled material and a camber, can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an algorithm of a method for setting a rolling reduction of a hot plate rolling mill according to the first invention of the present application.

FIG. 2 is a diagram showing an algorithm of a method for setting a rolling reduction of a hot plate rolling mill according to the second invention of the present application.

FIG. 3 is a diagram showing an algorithm of a method for setting a rolling reduction of a hot plate rolling mill according to the third invention of the present application.

FIG. 4 is a plan view showing a relationship between a roll and a peripheral speed vector when a roll cross occurs.

FIG. 5 is a front view and a side view when a vertical work roll of a four-high rolling mill, which is a typical hot plate rolling mill, crosses by a small angle.

FIG. 6 is a diagram in which the relationship between a roll cross angle and a thrust coefficient (a value obtained by dividing a thrust force and a tightening load) obtained in an experiment is arranged for three types of lubrication states.

FIG. 7 is a schematic view showing a side surface of a four-high rolling mill which is a typical hot plate rolling mill.

FIG. 8: Actual hot strip mill finishing mill No. The figure which applied the roll bending force at the time of no load in 6 stands, plotted the correspondence with the output of the rolling load measuring device, and approximated the data linearly by the least square method.

FIG. 9 is a diagram in which data is approximated by a straight line having a slope of 1 with respect to the same data as in FIG. 8;

FIG. 10 shows an actual hot strip mill finishing mill No. The figure which applied the roll bending force at the time of no load in 7 stands, plotted the corresponding relationship with the output of the rolling load measuring device, and approximated the data with the straight line of the gradient 1.

11 is a diagram in which the same data is collected by the same rolling mill as in FIG. 10 half a year after the data collection in FIG. 8, and the data is approximated by a straight line having a gradient of 1.

FIG. 12 is a diagram showing the relationship between the rolling reduction value obtained by the kiss roll tightening test and the load measured by the rolling load measuring device separately for the working side (WS) and the driving side (DS).

FIG. 13 calculates the deformation of the roll system from the data of FIG.
FIG. 11 is a diagram showing the deformation characteristics of the housing / rolling system obtained by separating the WS / DS separately in relation to the amount of deformation of the housing / rolling system and the rolling load.

FIG. 14 is a diagram showing an algorithm of a conventional rolling reduction method of a hot plate rolling mill.

[Explanation of symbols]

1 Rolling load measuring device 2-1 and 2-2 Increase work roll bending device 3-1 and 3-2 Increase work roll bending device 4-1 and 4-2 Decrease work roll bending device 5-1 and 5- 2 Decrease work roll bending device 6-1 and 6-2 Reinforcement roll balance device 7-1, 7-2 Reinforcement roll balance device 8-1, 8-2 Work roll 9-1, 9-2 Reinforcement roll 10-1 , 10-2 Work roll chock 11-1, 11-2 Reinforcement roll chock 12 Roll-down device 13 Housing 14 Work roll bending device Working oil pressure measurement device 15 Peripheral velocity vector at upper roll upper and lower roll contact surfaces 16 At lower roll upper and lower roll contact surfaces Circumferential velocity vector 17 Relative velocity vector on upper and lower roll contact surfaces 18 Draft Thrust force vector acting as a reaction force to the thrust force vector 20 rolling load measuring device in a mill bottom (load cell) acting as a thrust force vector 19 counterclockwise via the lower reinforcing roll chocks force acting on the roll

Claims (3)

(57) [Claims] A rolling load measuring device and a work roll;
In the method of setting the rolling reduction of a multi-stage hot plate rolling mill having a reinforcing roll, in a state where lubricating oil is supplied to a contact portion between the rolls, operating a drafting device in a non-rolling state while rotating the rolls, and operating the upper and lower work rolls And the screw-down device was further tightened, and the zero point adjustment of the screw-down device was performed according to the output of the rolling load measuring device so that the load acting between the upper and lower work rolls was evenly distributed to the working side and the drive side. A method for setting a rolling reduction of a hot strip rolling mill, wherein the setting of a rolling device on a working side and a driving side is performed above. 2. A method according to claim 1, wherein a hydraulic work roll bending device, a rolling load measuring device, and a method for setting a rolling reduction of a multi-stage hot plate rolling mill having a work roll and a reinforcing roll are provided. In the state,
The work roll bending device applies two or more levels of load in the direction of opening the upper and lower work roll gaps, and the hydraulic pressure detected by the pressure measuring device for the supply oil to the working cylinder of the work roll bending device and the effective disconnection of the working cylinder The roll bending force calculated from the area and the configuration and number of working cylinders, and the corresponding relationship between the output of the rolling load measuring device that measures the load of the rolling-down device is analyzed, and the rolling load measuring device of the rolling load measuring device is analyzed from the correlation between the two. Calibrate the zero point or both the zero point and the sensitivity, and with the lubricating oil supplied to the contact between the rolls, operate the drafting device in a non-rolling state while rotating the rolls to contact the upper and lower work rolls,
After further tightening the screw-down device, the zero-point adjustment of the screw-down device is performed according to the output of the rolling load measuring device so that the load acting between the upper and lower work rolls is evenly distributed to the working side and the drive side. Setting method for a hot plate rolling mill, wherein setting of a pressing device on a side and a driving side is performed. 3. A rolling load measuring device and a work roll,
In the method of setting the rolling reduction of a multi-stage hot plate rolling mill having a reinforcing roll, in a state where lubricating oil is supplied to a contact portion between the rolls, operating a drafting device in a non-rolling state while rotating the rolls, and operating the upper and lower work rolls , And further tighten the screw-down device, at several points in the course of the process,
The output of the rolling load measuring device and the rolling set position on the working side and the driving side are simultaneously sampled, the deformation characteristics of the roll system corresponding to the conditions at each time are calculated and separated, and the resulting housing and rolling system A reduction setting method for a hot strip rolling mill, wherein a difference between a reduction setting value on a working side and a reduction value on a driving side is calculated using data on the asymmetry between the working side and the driving side of the deformation characteristics.