JPS6082212A - Method for controlling camber of material to be rolled - Google Patents

Abstract

PURPOSE:To control exactly a camber by determining the respective strain amounts on the working side and driving side of a rolling mill during rolling, determining the camber amt. from the strain amt. and changing the roll gap. CONSTITUTION:When the front end of a steel plate 5 bites to a rolling mill 7, a camber control device 4 reads the signals from a roll gap measuring device 1, a load cell 2 and a thickness gage 3. The control device estimates the camber amt. of the steel plate by calculating said amt. from the read values. The control device emits the command for the roll gap to a draft control device 8 on the working side of the mill 7 or a draft control device 9 on the driving side from the estimated camber amt. of the steel plate to control the target roll gap thereby controlling the camber.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for controlling camber generated in a rolled material during a rolling process.

Conventional technology and problems A rolling mill that rolls materials to be rolled such as steel plates requires 1ul of work.
A rolling reaction force detector such as a load cell, a roll opening measuring device, and a plate thickness detector (also called a thickness gauge) are installed on each of the l (WS) and drive side (DS), and these are used to control plate thickness. etc. will be carried out.

For rolling work, after completing the roll opening and rolling mill speed settings, align the steel plate center with the rolling mill center using side guides, and then blow the steel plate into the rolling mill. At this time, the steel plate center and rolling mill center are Due to misalignment, difference in temperature distribution in the width direction of the steel sheet, difference in abrasive quality in the width direction of the steel sheet, and difference in rigidity between the WS and DS of the rolling mill, the rolled steel sheet may have a canon (left side).

A right turn occurs.

In recent years, a camber control device for reducing the amount of camber generated during rolling has been put into practical use in order to improve the yield in the rolling process. The conventional camber control device is either an optical type as a steel sheet cantilever detector, or a device that detects the difference between WS, DS and rolling resistance.
Or, they only use a device that detects the thrust force in the width direction of the steel plate, and the environmental conditions of the rolling mill and the WS-D during rolling
Due to the presence of S interaction, etc., it was not reliable enough as a camber control device.

OBJECTS OF THE INVENTION The present invention has been made to eliminate the drawbacks of the conventional method, and to provide a canner control method that can sufficiently prevent the occurrence of camber and can be easily applied to existing rolling mills. purpose.

Composition of the Invention The camber control method of the present invention calculates the amount of strain on the working side and drive side of the rolling mill during rolling, and calculates the amount of camber generated in the material to be rolled from the strain amount. The present invention is characterized in that the opening degree of the working side or driving side roll of the rolling mill is changed according to the camber amount to reduce the camber amount, which will be explained in detail next.

Embodiments of the Invention First, the present invention will be explained in detail (Type 11 is the conventional AG
This defines the C operation.

Here, Sl: Roll opening M; Mill constant F: Rolling reaction force HO: Fj, plate thickness In the present invention, the cause of camber generation is considered to be the difference in the rolling reduction ratios of WS and DS. Therefore, (11 equations are 1) 3
．． Separate ws, and set the Mill constant M in the next horizontal row.
M12 M21 M22: M matrix elements FD, Fw
: Rolling reaction force Sl of each DS and WS ”+w' DS
+ WS each roll opening degree Ho, HoW: D S
, WS Each steel plate thickness ()-' : D"' indicating the inverse matrix M21 shows the change in WS due to the change in DS rolling reaction force.
This term indicates the change in steel plate thickness. Under normal rolling conditions, the value of M1□M2□ does not become zero due to a misalignment between the center of the steel plate and the center of the rolling machine or a defective cross-sectional shape of the steel plate. Furthermore, M
The elements of the matrix are not constants, but are measured during rolling and the values at that point are calculated.

In the present invention, the amount of camber of the steel sheet is calculated using the M matrix defined by equation (2). This utilizes the fact that there is a correlation between the steel sheet camber amount, the DS rolling mill strain amount, and the WS rolling mill strain (2). Equation (3) shows the DS rolling mill strain m occurring from a certain time t1 to time t2, and equation (4) shows the WS rolling mill strain amount from a certain time t1 to time [2].

Here: Conversion coefficient ΔHD 2 ”” HOD2 '5ID2ΔHD I
"" ODI-51131 subscript 1.2 is time t+, t
Indicates the value at z.

ΔCDs: DS steel plate camber amount Here: Conversion coefficient Δ Summer (W 2 = HOWZ 5IW2ΔHw+ =
How1SIWI Subscript 1.2 indicates the values at times tl and t2.

ΔCws: WS WI board camber amount above (31
, (The reason why 41 is obtained is as follows.

ΔCp5=K (Fp 2 FD r ) / (ΔH
D2-ΔHDI) is a defining formula, and the DS rolling mill strain amount ΔCDS is defined in this way. The same applies to the WS side. To explain why the right-hand side holds true, at time t+,
The above equation (2) at t2 becomes the following equations (el, (fl).

Note that the M matrix elements in the interval from time t1 to L2 do not change. (eL (f1 formula ΔHDI=H5ll) 1゜01 ΔHD 2 ”” Ho1)2 , 31+)2 +ΔH
When transformed as WI = HOWI 5IWI r ΔHW 2 ''' ll0W2 5IW2, the following formula +ffF (hl) is obtained.

Adding the elements of the M matrix from this, we get 1 S 1 = Δ tr D , Δ HW2 −
Δ HD2 Δ Hw.

Here ΔHw, -ΔHw2. If Fw+ = FW2, Mll M2+ = (FD2 FDI)/(ΔH
D2-ΔHDI), and the above formula (31) holds true.Similarly, ΔHDI=Δ
HD2. If FDI = FD2, then M22 M+2 = (FW2 FWI) / (Δ
HW2-ΔHw+), and the above formula (4) is established. These equations (3) (
Using the formula 4), the amount of camber of the steel plate is determined by the camber convex to the DS side.
1 Here, N: Number of sections of steel plate length ΔCDs DS steel plate camber amount ΔCw in two sections ■
8: Amount of WS steel plate camber in section I C: Amount of steel plate camber Mll-M22: Value of Mll to M22 in section I The camber amount of the steel plate estimated from equation (5) is calculated when the tip of the steel plate touches the rolling mill work roll. It is measured as a deviation from the standard value in the form of a time series with the time of biting as the standard. The control method for preventing the occurrence of camber is based on the value of the steel plate camber amount estimated from equation (5), and the WS roll opening or DS
This is done by controlling the roll opening sound.

Examples will be described below. The rolling mill configuration and camber control device configuration are not shown in the drawing. Normally, a rolling mill has a detector 1 that measures the roll opening degree and a load cell 2 that measures the rolling reaction force.
and a thickness gauge 3 for measuring the thickness of the steel plate. The camber control device 4 receives the signals from these detectors 1 to 3, and calculates equations (3), (4), and (5),
The output signal is sent to the rolling mill WS or DS rolling control device 8 or 9.
and control the roll opening. 5 is a steel plate, 6 is a table roll, 7 is a rolling machine, 10 is its work roll,
11 is a bank up roll, and 12 is a drive device for a reduction screw 13.

To explain the operation, when the tip of the steel plate 5 bites into the rolling mill 7, the camber control device 4 reads the signals from the roll opening degree measuring device 1, the load cell 2, and the thickness gauge 3. From this read value, elements M1□~M2□ of M matrix defined by formula (2)
From the values of M matrix elements calculated by calculating the value of (3) and (4)
) Using equation (5), 1liIF! Estimate the amount of camber. Based on the IIE determined steel sheet camber amount, the WSS rolling control device 8 of the rolling mill 7 issues a roll opening command to the DS rolling control device 9 of the rolling mill 7 to control the target roll opening, and formula (5) is obtained. Camber control is performed by setting the value to 0.

In addition, in the above, rolling mill strain amount ΔCDS and ΔCWS are +
3) and +4), but it may also be measured by actual measurement.

Effects of the Invention In the present invention, camber control is performed according to the values of the elements of the M matrix obtained by measuring every moment during rolling, so it is possible to fully take into account the environmental conditions of the rolling mill and the WS-DS interaction during rolling. It is possible to perform accurate camber control. Further, the various detection terminals used for this control are already installed, and only the camber control device 4, that is, the arithmetic unit, is newly added, so there is an advantage that it can be easily implemented in an existing rolling mill.

[Brief explanation of the drawing]

The drawing is an explanatory diagram showing the configuration of a rolling mill and a camber control device. 1... Roll opening measuring device 2... Load cell 3.
... Thickness gauge 4... Camber control device 5... Steel plate 6... Table roll 7... Rolling machine 8...
・WS reduction control device 9...DS reduction control device 10
...Work role 11...Backup role
12...Reduction screw drive device I3...Reduction screw Applicant: Nippon Steel Corporation Representative Patent Attorney Minoru Aoyanagi

Claims (2)

[Claims] (1) Calculate the amount of strain on the working side and drive side of the rolling mill while rolling the material to be rolled, calculate the amount of camber generated in the material to be rolled from the amount of strain, and calculate the amount of camber generated in the material to be rolled from the amount of strain, and use the amount of camber to determine the amount of strain on the working side of the rolling mill. Alternatively, a camber control method for a rolled material, characterized by reducing the amount of camber by changing the opening degree of the drive side roll. (2) The amount of strain on the working side and drive side of the rolling mill, each rolling reaction force on the working side and drive side of the rolling mill, the opening degree of the working side drive side roll,
and a work side driving side number, the thickness of the rolled material is measured, a mill constant is calculated from the measurement result, and the mill constant is calculated from a time series of the mill constant. How to control the camber of the moon.