JPH0390207A - Meandering control method of plate rolling time - Google Patents

Abstract

PURPOSE:To constrain a meandering and to improve the quality of a product by operating such a levelling change quantity that a meandering quantity comes in an allowable range after the lapse of a specific time based on the meandering quantity and the time derivation thereof and controlling a rolling mill based on this levelling change quantity. CONSTITUTION:A meandering quantity processing arithmetic part 4 operates and measures the meandering quantity of a rolled stock 2 and the time derivation thereof by receiving a detection signal transmitted from a meandering detector 3. A levelling change quantity arithmetic part 5 operates a specified levelling change quantity so that the meandering quantity of the rolled stock 2 comes in an allowable range after the specific time lapse based on the measurement result fed from the meandering quantity processing arithmetic part 4. The arithmetic result by the arithmetic part 5 is transmitted to the rolling reduction system control device 1c of a rolling mill 1, the levelling output is executed by a screw down device 1b and the meandering quantity of the rolled stock 2 is controlled with the control of the rolling mill 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling both the meandering state and the camber during rolling of a plate material.

[Prior Art] When rolling a plate material, a phenomenon may occur in which the plate material escapes from the center of the mill during rolling. When this plate escape phenomenon occurs, the plate material hits the side guide and squeezes, causing damage to the roll and a difference in thickness between the left and right width edges of the plate.
This will lead to deterioration of product quality and decreased productivity.

This phenomenon tends to occur when the plate material is pulled out, that is, when there is no tension on the entry side.

Conventional control means include means for measuring the meandering equivalent amount and manipulating the leveling amount proportional to that amount, and means for manipulating the leveling amount corresponding to the sum of the meandering equivalent amount and the differential value. . Further, as means for measuring the amount of meandering, methods have been proposed, such as means for measuring the difference in load between the left and right sides of the rolling mill, and means for measuring the movement of the left and right width edges using sensors.

On the other hand, as a means to control the amount of camber of a plate material, conventionally a camber meter is installed on the entrance side of a rolling mill.

Means is used to measure the amount of camber of the incoming plate material and change the amount of leveling. This method is mainly applied to thick plate rolling.

[Problems to be Solved by the Invention] Incidentally, the amount of meandering and the amount of camber influence each other, and the conventional control means described above only focus on suppressing the amount of meandering or camber. If one is controlled, the other will be sacrificed. Particularly, when hot rolling is performed in a region where the thickness of the sheet material is thin, the contradiction between the two controls increases.

The present invention aims to solve the above-mentioned problems, and is a meandering control method during sheet rolling that improves product quality by simultaneously suppressing meandering and camber of the rolled sheet material. The purpose is to provide

[Means for Solving the Problems] In order to achieve the above-mentioned object, the method for controlling meandering during rolling of a plate according to the present invention (Claim 1) controls the amount of meandering of a plate material at the entrance or exit side of a rolling mill. Measure the time differential value of meandering amount,
Based on the measured meandering amount and its time differential value, a certain leveling change amount is calculated so that the meandering amount of the plate material falls within an allowable range after a predetermined period of time has elapsed, and the leveling change amount is sent to the rolling system control device of the rolling mill. The feature is that the amount of meandering is controlled by controlling the amount of meandering.

Further, the meandering control method (claim 2) during plate rolling of the present invention is based on the meandering amount of the plate material and the time differential value of the meandering amount so that the meandering amount of the plate material falls within an allowable range after a predetermined period of time has elapsed. After calculating a certain amount of leveling change in advance and storing the calculation results as a table, measuring the amount of meandering of the plate material at the entrance or exit side of the rolling mill and the time differential value of the amount of meandering, Obtaining a constant leveling change amount based on the measured meandering amount and its time derivative value and the table,
It is characterized in that the meandering amount is controlled by sending the leveling change amount to a rolling system control device to control the rolling mill.

Furthermore, the meandering control method during plate rolling of the present invention (claim 3)
The method according to claim 1 or 2 is characterized in that the input side wedge amount of the plate material is actually measured, and the actually measured input side wedge amount is used when calculating the constant leveling change amount.

[Function] In the method of claim 1 described above, first, the amount of meandering of the plate material and its time differential value are measured, and based on the measurement results,
The input side wedge amount of the plate material, the leveling offset amount of the rolling mill, etc. are calculated, and using the calculation results,
A certain amount of leveling change is calculated so that the amount of meandering will be within the allowable range at a future specified time (after a predetermined time has elapsed). Then, based on this leveling change amount, the rolling mill is controlled by the rolling system control device, and the meandering amount of the plate material is suppressed and controlled.

In the above-mentioned method of claim 2, before actual control is performed, the meandering amount of the plate material falls within an allowable range after a predetermined period of time according to the meandering amount of the plate material and the time differential value of the meandering amount. A certain leveling change amount is calculated in advance and stored as a table. Then, meandering control is performed in the same way as the method described at the top of the claim, but when calculating a constant leveling change amount, the measured meandering amount and its time derivative are applied to a stored table to achieve a constant leveling change. I'm getting quantity.

Furthermore, in the methods described in claims 1 and 2, by actually measuring the wedge amount of the plate material determined by calculation, it becomes possible to calculate the constant leveling change amount more precisely (il claim).

[Embodiment of the Invention] A meandering control method during plate rolling as an embodiment of the present invention will be explained below with reference to the drawings. Fig. 1 is a block diagram showing the configuration of an apparatus for carrying out the method of the present invention. ,
In FIG. 1, 1 is a rolling mill, 1a is a rolling roll of the rolling mill 1, 1b is a rolling device which is controlled by a rolling system control bag W11c and performs leveling adjustment in the rolling mill 1, and 2 is a rolling mill. The rolled material (plate material) enters into the rolling mill 1 and is rolled. 3 is a meandering detector that measures the meandering amount of the rolled material 2 on the one-man side of the rolling mill. 4 receives the detection signal from the meandering detector 3 and detects the rolled material. The meandering amount processing calculation unit 5 that calculates and measures the meandering amount and its time differential value in step 2 calculates the calculation formulas (7) to (1) described later based on the measurement results from the meandering amount processing calculation unit 4.
0) is used to calculate a constant leveling change amount ΔSc so that the meandering amount of the rolled material 2 falls within the allowable range after a predetermined period of time has elapsed.The calculation result (ΔSc) by this calculation unit 5 is The information is sent to the rolling system control device 1c of the rolling mill 1, and leveling is output by the rolling device 1b.
By controlling the amount of meandering of the rolled material 2, the amount of meandering of the rolled material 2 is controlled.

Next, the calculation formula used in the leveling change amount calculation section 5 will be explained. First, the input side wedge amount of the rolled material 2 (the difference in plate thickness between the left and right sheet width ends of the rolled material 2) is ΔH1, the input side meandering amount is Δy0, and the leveling offset amount of the rolling mill 1 is ΔS0.
, the operated leveling amount is ΔS, the output side wedge amount of the rolled material 2 is Δh, and the difference in the left and right rolling reduction ratio is Δr, then this difference in the rolling reduction ratio between the left and right sides Δr is given by the following equation (1).

Δ r:AHΔH+AvΔy−As(ΔS0+ΔS)
-<1) Here -Ale AY+
As is a positive coefficient, and Δr.

ΔH is positive when the work side increases, Δy is positive when the rotation side relief is positive, and ΔS is positive when the work side opens.

Further, the meandering amount Δy is given by the following equation (2).

Δy"KE f'f"Δr dtdt+Δy o
-(2)G.

By substituting equation (1) into equation (2), equation (3) is obtained, and by differentiating both sides thereof by 21W, equation (4) is obtained.

Δy=Kp: f'f'(AHΔH+AyΔy−
As(ΔSQ+ΔS)]dtdtG 1Δy8 ...(3) ...(4) As a general solution to equation (4), which is a 2N differential equation, α=
When Q is assumed, the following equation (5) is obtained.

Δy==I)exp(at)+F・exp(−at)
= (5) In the above formulas (2) to (5), KE, D,
Both F are coefficients.

Now, as a practical matter, the change in ΔH is of a negligible order, so assuming that ΔH is constant and ΔS is constant, the special solution to equation (4) is expressed by the following equation (6). .

Here, C2, C3, and C are coefficients determined by knowing the amount of meandering on the entry side of the rolled material 2.

The solution of Δy including the special solution is the following equation (7) using equations (5) and (6).

here, and replace it with 1=1. So Δy=Δyl,, Δy view ΔVh+ at 1 = 1 engineering dΔy/dt−aΔy1 and Then.

From the above formula (7), K.E.A.

+□(ΔS+Δ, S,)+C(to) α2...(8) EAH Δy,=Dexp(αt,)+F'exp(-αt,
)−□ΔHα2. Here, if it is set, then F and V are determined as unknowns from the above equations (8) to (lO). A constant leveling change amount ΔSc that makes Δy = ΔyA at time t=tA, that is, a constant leveling change amount ΔSc that causes the meandering amount Δy of the rolled material 2 to fall within the allowable range ΔyA after a predetermined time tA has been determined. It is obtained by substituting the unknowns, F, and V into equation (7). In addition, in the above formulas (8) to (10), ΔyotΔy1
+aΔy1 is the meandering detector 3 in this embodiment.
and known values calculated and measured by the meandering amount processing calculation unit 4. Further, the calculation of the leveling change amount ΔSc using equations (7) to (10) is performed by the leveling change amount calculation unit 5.
It will be held at

In addition, in this example, the entrance wedge amount ΔH of the rolled material 2 is included in V as an unknown quantity, and is calculated as a solution to equations (8) to (10). If measured, it is possible to obtain a more strictly constant leveling change amount ΔSc in equation (6) and equation (7) derived from equation (6).

In the device of the present embodiment, which is equipped with the leveling change amount calculation unit 5 having the calculation function as described above, the meandering detector 3 determines that time 1=1. Detect the meandering amount Δy0 of the rolled material 2 at
It is stored in the meandering amount processing calculation section 4. Similarly, the meandering amount Δyy of the rolled material 2 after a minute time has elapsed (t=tt) is detected and transmitted to the meandering amount processing calculation unit 4, and the meandering amount Δy o
Time differential value dΔy/dt of meandering amount based on kΔy1
= aΔy is calculated from the meandering amount processing calculation section 4, which calculates the meandering amount Δ3' o eΔy and its time differential value aΔ
y is sent to the leveling change amount calculation unit 5, and the leveling change amount ΔS is calculated using equations (7) to (10) as described above.
Compute c. Then, the calculated leveling change amount Δ
Based on So, the rolling device 1b of the rolling mill 1 is controlled by the rolling system control device 1c, and the meandering amount of the rolled material 2 is suppressed and controlled.

The specific effects of the apparatus of this embodiment are shown in FIGS. 2(a) to 2(c) in comparison with conventional control and non-control cases.

Each figure shows changes in camber curvature, plate meandering amount, and plate wedge amount, and as is clear from each figure, by using the device of this example, camber curvature, plate meandering amount, and plate wedge amount All changes in wedge amount become smaller.

As described above, according to the meandering control method of this embodiment, it is possible to reliably suppress the meandering of the rolled material 2 within the permissible range during plate rolling, and at the same time, it is possible to suppress the camber and wedge amount of the rolled material 2. Therefore, rolling troubles in the rolling process and subsequent processes can be significantly reduced, and product quality can be greatly improved.

By the way, in the above-mentioned embodiment, a constant leveling change amount ΔSc is calculated in real time in the leveling change amount calculation unit 5 using equations (7) to (10) based on data measured during actual meandering control. However, claim 2
According to the described method, before performing actual meandering control, the meandering amount Δy of the rolled material 2 and its time differential value δΔy are appropriately classified, and for each classification, the meandering amount of the rolled material 2 is calculated after a predetermined period of time has elapsed. Constant leveling change amount Δ that falls within the acceptable range
Sc may be calculated in advance and stored in a memory (not shown) as a leveling change table as shown in Table 1 below.

When creating this table, a constant leveling change amount ΔSc for which the meandering amount Δy falls within the allowable range after a predetermined time has elapsed for the standard path of the standard steel type is determined by the time differential value δΔy divided into five ranges a Nd of the meandering amount Δy. Each of the 20 categories is calculated in advance based on the above-mentioned equations (7) to (10) and stored in a table as shown in Table 1 below.

Note that the range a = d of the meandering amount Δy is determined, for example, as shown in FIGS. 3(a) and 3(b). Moreover, the arrow in FIG. 3(a) indicates a time differential vector.

Table 1 Note that for range symbols b-d, the meandering amount range is negative (-
) side also has a table.

When calculating a constant leveling change amount ΔSc during actual meandering control, the meandering amount Δy and its time differential value δΔy calculated and measured by the meandering detector 3 and meandering amount processing calculation unit 4 are stored. These values Δy and aΔy correspond to the standard leveling change amount ΔSC.

Select. Furthermore, in the leveling change amount calculation unit 5, the following (11) is applied to the selected standard leveling change amount ΔSCo using the steel type correction coefficient K K + plate thickness correction coefficient KA and rolling speed correction coefficient X<S of the rolled material 2. By performing correction processing based on the formula, a constant leveling change amount Δ
I'm looking for Sc.

The constant leveling change amount ΔSc obtained in this way
Based on this, the rolling device 1b of the rolling mill 1 is controlled by the rolling system control device 1c, and the meandering amount of the rolled material 2 is suppressed and the same effect as in the above embodiment can be obtained.

In the above embodiment, the meandering amount of the rolled material 20 on the inlet side of the rolling material 20 is measured by the meandering detector 3 installed on the inlet side of the rolling mill 1, but the meandering amount of the rolled material 2 on the exit side of the rolling mill 1 or the rolling It goes without saying that the control method of the present invention can also be implemented by measuring the amount of meandering of the rolled material 2 directly under the roll la.

[Effects of the Invention] As detailed above, according to the meandering control method during plate rolling of the present invention (claims 1 and 2), the meandering amount of the plate material is controlled after a predetermined period of time based on the meandering amount and its time differential value. Since the rolling mill is controlled based on this leveling change, it is possible to reliably suppress the meandering of the plate material within the allowable range, and at the same time prevent the camber and wedge of the plate material. This has the effect of significantly reducing rolling troubles in the rolling process and subsequent processes, as well as significantly improving product quality.

In addition, by using the actual measurement result of the input side wedge amount of the plate material when calculating the - constant leveling change amount (claim 3), the constant leveling change amount can be determined extremely strictly, and the control accuracy can be improved. There are also effects that can be further improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an apparatus for implementing a meandering control method during plate rolling as an embodiment of the present invention, and FIG.
Figures (a) to (c) are graphs for explaining the effects of the above embodiment, and Figure 3 (a). (b) is a diagram for explaining range symbols of meandering amounts. In the figure, 1-rolling mill, 1a-rolling roll, 1b-rolling device, 1c-rolling system control device, 2-rolling material (plate material),
3-meandering detector, 4-meandering amount processing calculation section, 5-leveling change amount calculation section.

Claims (3)

[Claims] (1) Measure the meandering amount of the plate material on the entry side or exit side of the rolling mill and the time differential value of the meandering amount, and based on the measured meandering amount and its time derivative value, the plate material will be removed after a predetermined period of time. A constant leveling change amount is calculated so that the meandering amount is within an allowable range, and the leveling change amount is sent to a rolling system control device of the rolling mill to control the meandering amount of the plate material. A meandering control method during plate rolling, characterized by: (2) Calculate in advance a certain leveling change amount according to the meandering amount of the plate material and the time differential value of the meandering amount so that the meandering amount of the plate material falls within the allowable range after a predetermined period of time has elapsed, and calculate the calculation result. After storing it as a table, measure the meandering amount of the plate material and the time differential value of the meandering amount at the entrance or exit side of the rolling mill, and record the measured meandering amount and its time derivative value in the table. During plate rolling, the meandering amount of the plate material is controlled by obtaining a certain leveling change amount based on the leveling change amount and sending the leveling change amount to a rolling system control device of the rolling mill to control the rolling mill. meandering control method. (3) The meandering control method during plate rolling according to claim 1 or 2, characterized in that the wedge amount of the plate material is actually measured and the measured wedge amount is used when calculating the constant leveling change amount.