JPH06304622A - Method for estimating roll profile to set leveling of hot finishing rolling mill and setting method therefor - Google Patents

Abstract

PURPOSE:To easily estimate a quantity of expansion, a quantity of wear by measuring a difference load in a zero checking time for rolling down and leveling after work rolls are recombined, storing it as an initial value, reproducing a kiss roll state at a zero checking time in an idle time and calculating a roll profile through a difference between the difference load and the initial value at that time. CONSTITUTION:The difference load at the zero checking time for the rolling down and leveling is measured after the work rolls are recombined in a hot finishing rolling mill 1 and this is stored as the initial value. The kiss roll state at the zero checking time is reproduced in the idle time after an arbitrary number of sheets are rolled, the difference load at that time is measured and stored and further a roll profile change in the width direction is calculated by a difference from the previously stored initial value. In this way, the roll profiles on the work side WS and the drive side DS in a rolling time can be detected without using a special measuring apparatus and the thickness, crown and shape of a rolled sheet can be improved in accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll profile prediction method for setting the leveling of a hot rolling finish rolling mill and a leveling setting using the same.

[0002]

2. Description of the Related Art Conventionally, since the work roll profile of a hot rolling finish rolling mill shows a complicated change due to wear and thermal expansion during rolling operation, the work roll profile data of a known roll is used to calculate the work roll profile of the rolling mill. If the operating conditions are determined, errors due to the work roll profile estimation error will occur in the plate thickness, plate crown, and shape. Therefore, in order to avoid such an error, it is necessary to estimate the work roll profile, but conventionally, using the roll wear calculation formula and the roll thermal expansion calculation formula, from the rolling operation conditions, There are a method of calculating and estimating a work roll profile at an arbitrary time point and a method of directly measuring the work roll profile using a contact type or non-contact type displacement meter.

Further, as disclosed in Japanese Patent Laid-Open No. 63-29509, for the purpose of measuring the work roll profile without using the above-mentioned dedicated measuring device for direct measurement, the rolling-down device during the interruption period of the rolling operation. By contacting the upper and lower work rolls, and the relationship between the rolling set value obtained by further tightening and the rolling reaction force device value by the rolling reaction force measuring device, compared with the same relationship when incorporating the work roll, analysis By doing so, a roll profile detection method is known in which the amount of change in the work roll profile from the time of incorporation is calculated and calculated.

[0004]

In the above-mentioned prior art, since the roll thermal expansion amount is predicted by the change from the initial value of the kiss roll sum load during idling, only the average thermal expansion amount in the width direction is known, It is not useful for leveling control because it is not expanded in the width direction. In addition, since it is an expensive facility for online measurement using a roll profile measuring device, and it is a precision measuring device that is used in a bad environment, it requires a large amount of acquisition and cost to maintain and maintain the precision. In addition, there is a problem that it becomes a factor that deteriorates the workability of normal rolling work such as work roll change. Therefore, the present invention, without using a dedicated measuring device as described above,
The purpose is to easily predict the amount of expansion and the amount of wear in the width direction.

[0005]

In order to achieve the above object, the present invention provides: (1) In a hot rolling finish rolling mill, a differential load at the time of reduction and leveling zero adjustment after changing work rolls is applied. Measure and store this as an initial value, reproduce the kiss roll state during zero adjustment at idle after rolling an arbitrary number of strips, measure and store the differential load at that time, and further by the difference from the initial value stored earlier. Roll profile prediction method for leveling setting of hot rolling finish rolling mill, characterized by calculating roll profile change in width direction (2), Roll for setting leveling of hot rolling finish rolling mill according to (1) According to another aspect of the present invention, there is provided a leveling setting method for a hot rolling finish rolling mill, which comprises setting a roll gap based on a profile prediction and performing leveling.

[0006]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic view showing a reduction control mechanism of a hot rolling finish rolling mill. As shown in FIG. 1, a rolling mill 1 is a four-high rolling mill having upper and lower work rolls 2 for biting and rolling a plate material and upper and lower backup rolls 3 for sandwiching and pressing the upper and lower work rolls 2 from above and below. It is composed of Then, the reduction device 4 and the work roll 2 which are provided on the roll chock of the backup roll and apply a rolling load.
A roll-down position detector 5 for detecting the roll gap between the edge portions and a load detector 6 for detecting the roll-down load are provided on each of the work side (WS) and the drive side (DS) for leveling. For setting, a controller 7 for controlling each of the reduction device 4 and the load detector 6 for detecting the reduction load, for example, the reduction position detector 5 for detecting the reduction load from the load cell and the roll gap. And an arithmetic unit 8 with a memory.

FIG. 2 is an explanatory view showing a reduction control system of a hot rolling finish rolling mill according to the present invention. As shown in FIG. 2, the differential load between the work side (WS) and the drive side (DS) after changing the work rolls and at the time of leveling zero adjustment is measured in the arithmetic unit 8, and this is used as the initial roll profile, Also, the kiss roll state during zero adjustment is reproduced during idle after any number of plate pressures, the differential load between the work side and drive side at that time is measured, and the roll profile changes in the width direction due to the difference from the initial value. The level is corrected by the minute. At this time, since the mill rigidity on the work side is different from that on the drive side, the appearance of the differential load may differ in the rolling load area.Therefore, the predicted load of the next plate is received from the host computer, and it becomes close to the predicted load. It is also necessary to tighten the roll gap to the gap and obtain the differential load.

FIG. 3 is a diagram showing a flowchart of the control system according to the present invention. First, a signal from each of a roll-down value detector for detecting a roll gap and a load detector for detecting a roll-down load is used as a work-side roll-down value S.
_W , drive-side reduction value S _D and work-side load P
_As the signal composition of _W and the drive side load P _D , the center rolling reduction value S _C = (S _W + S _D ) / 2, the leveling ΔS
= S _W -S _D, the sum load P _T = P _D -P _W, the difference load △ P =
The P _D -P _W. And reduction zero P _T = P _TO (constant)
When S _CO = 0 and ΔS ₀ = 0 at times, ΔP ₀ = P _D0 −P _W0 as a differential load measurement and memory at the time of zero rolling reduction, while a kiss roll at zero time at idle after rolling an arbitrary number of strips. The state is reproduced so that S _C = 0 and ΔS = 0. Then the kiss roll time difference load measurement and storage _{△ P n = P Dn -P Wn} ,
(N = 1, 2 ...)

Further, due to the difference from the previously stored initial value
Predict roll profile changes across the width. That is,
Differential load fluctuation X_n= △ P_n-△ P₀, Roll profile change
R _n= X_n/ MM (however, MM: mill rigidity)
Leveling at Rm / 2 based on the profile prediction
And roll the plate, and after the rolling is completed,
Measurement.

[0010]

[Example] The differential load during the reduction and leveling zero adjustment after changing the work rolls is measured and used as the initial value. The values at that time, after rolling an arbitrary number of strips, and after a certain rolling progress, were as shown in Table 1.

[0011]

[Table 1]

ΔS _B = α (B-A) (where α: coefficient), the reduction of Ds is tightened by 0.04 mm, and ΔS _C = α (C-B). As a result, the amount of thermal expansion and the amount of wear in the width direction can be predicted easily, and the accuracy of the rolled plate thickness, plate crown, and shape was improved.

[0013]

As described above, by carrying out the present invention, it becomes possible to detect the roll profile on the work side and the drive side during the rolling operation without using a special measuring device, and It has an extremely excellent effect that the accuracy of the plate thickness, the plate crown, and the shape can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing a reduction control mechanism of a hot rolling finish rolling mill,

FIG. 2 is an explanatory view showing a reduction control system of a hot rolling finish rolling mill according to the present invention,

FIG. 3 is a diagram showing a flowchart of a control system according to the present invention.

[Explanation of symbols]

 1 Rolling mill 2 Work roll 3 Backup roll 4 Rolling down device 5 Rolling down position detector 6 Load detector 7 Controller 8 Computing device with memory

Claims (2)

[Claims] 1. A hot rolling finish rolling mill is used to measure the differential load during reduction and leveling zero adjustment after changing work rolls,
This is stored as an initial value, the kiss roll state at the time of zero adjustment is reproduced at the time of idling after rolling an arbitrary number of sheets, the differential load at that time is measured and stored, and the difference in the width direction due to the difference with the initial value stored earlier is stored. A roll profile prediction method for setting the leveling of a hot rolling finish rolling mill, characterized by calculating a roll profile change. 2. A leveling setting method for a hot rolling finish rolling mill, which comprises setting a roll gap and performing leveling based on a roll profile prediction for setting the leveling of the hot rolling finish rolling mill according to claim 1. .