JPH0246283B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the shape of a plate in a multi-stage cluster rolling mill.

When rolling a metal plate material, the shape of the rolled plate, that is, the flatness, will be impaired if the elongation in the longitudinal direction per unit width of the rolled material is not uniform in the width direction.

There are multiple forms of this shape defect, as shown in Figure 1a, edge elongation 1a where only both ends of the board are wavy
In the case of , as shown in Figure 1b, in addition to the case of medium elongation 1b in which only the center of the board is wavy, as shown in Figure 1c, there is a quarter-bend in which waves are formed at one quarter of the board. There are two cases, such as the case of a double wave 1c, and the case of a double wave 1d, in which waves are formed at both the center and both ends of the plate, as shown in FIG. 1d.

In order to control and flatten these board shape defects during rolling, multi-stage cluster rolling mills are usually equipped with multiple boards, such as a back-up roll crown adjustment device, a work roll bending device, and an intermediate roll bending device. Equipped with a shape correction device.

However, in order to eliminate plate shape defects, it is necessary to select and control the most effective plate shape correction device among the plurality of above-mentioned devices in response to various types of defects.

In view of the above, an object of the present invention is to provide a method for controlling the shape of a plate in a multi-stage cluster rolling mill, which can reduce defects in the shape of the plate. To achieve this objective, the present invention provides a multi-stage cluster rolling mill equipped with a plurality of shape correction devices such as a back-up roll crown adjustment device, a work roll bending device, an intermediate roll bending device, etc. 1 with the corresponding displacement in the plate width direction as a variable
Each of the following four-order functions is defined, and the deviation signal between the detection signal from the shape detector that detects the plate shape on the exit side of the rolling machine and the target shape setting value is expressed as a fourth-order orthogonal relationship consisting of the above functions. A shape modification device to be operated is selected according to the amount of each component, and the shape of the plate is modified according to the amount of the component.

The present invention will be described below with reference to the drawings.

FIG. 2 shows an embodiment of the present invention, in which 1 is a rolled material, 2 is a multi-stage cluster rolling mill (hereinafter referred to as a rolling mill), and the rolling mill 2 includes a rolling device 3 having a leveling function, A back-up roll crown adjustment device 4, a work roll bending device 5, and an intermediate roll bending device 6 are provided. For such a rolling mill 2, a shape detector 7 for detecting the plate shape is installed on the exit side of the rolling mill, and signals A to D are output for instructing the operation of each of the plate shape correction devices 3 to 6. A calculation device 8 is provided. This arithmetic device 8 is a host computer 9 or an operation panel 1.
Approximate the deviation signal between the target shape setting value E set at 0 and the detection signal F from the shape detector 7 by an orthogonal function regarding the amount of displacement in the board width direction, and calculate each component of the orthogonal function. By outputting one or all of the modified signals A to D, the modified signals A to D are output.
By outputting one or all D, the various plate shape correction devices 3 to 6 are operated individually or simultaneously.

Here, considering the form of shape defects, for the displacement x in the board width direction, ₀ (x) = a ₁ (x) = bx ₂ (x) = Cx ² + d ₃ (x) = ex ³ + fx ₄ (x)=gx ⁴ +hx ² +k ...Formula (1) (where a to k are constants) Define the following functions, and calculate the deviation signal α(x) using these functions α(x)f(x)= C _{0 0} (x) + C _{1 1} (x) + C _{2 2} (x) + C _{3 3} (x) + C _{4 4} (x) ...Equation (2) Fourth-order orthogonal function f(x) shown in Equation (2) It is assumed that it is approximated by

In formula (2), the zero-order component C _{0 0} (x) is related to the average plate thickness deviation, but the first to fourth order components are related to shape defects. That is, (1) the first-order component C _{1 1} (x) indicates that the rolled material has a one-sided elongation, and it is effective to correct the shape by controlling the leveling of the rolling reduction.

(2) The secondary component C _{2 2} (x) is the edge elongation (first
Figure a) or middle elongation (Figure 1 b) is shown. To correct these shapes, any one of the back-up roll crown adjustment device 4, work roll bending device 5, and intermediate roll bending device 6 is used. It is effective to operate one or more in combination.

(3) The third-order component C _{3 3} (x) indicates the degree of asymmetric waves such as when waves occur only at one end of the rolled material, and
The next component C _{4 4} (x) indicates the degree of quarterbuckling (Fig. 1 C) or double wave (Fig. 1 d) in the rolled material. To correct these shapes, leveling of the rolling device 3, Among the back-up roll crown adjustment device 4, the work roll bending device 5, and the intermediate roll bending device 6,
It is effective to operate either one or a combination of them.

To further explain the selection operations of the various shape modification devices 3 to 6, each component of the fourth-order orthogonal function is
C _{0 0} (x), C _{1 1} (x), C _{2 2} (x), C _{3 3} (x)
as well as
When C _{4 4} (x) is calculated, for example, the first-order component C _{1 1}
If the value of (x) is larger than the other component values, a correction signal A is output in accordance with the primary component value to operate the leveling of the rolling down device 3. Also, the secondary component
If the value of C _{2 2} (x) is large compared to other component values, a correction signal B is output in accordance with the secondary component value to operate the back-up roll crown adjustment device. Furthermore, each component C _{0 0} (x) ~ C _{4 4} (x)
If there is no extreme difference in the values, correction signals A to D are output depending on the magnitude of each component value, and the lowering device 3, back-up roll crown adjustment device 4, work roll bending device 5, and intermediate roll bending device 6 may be operated singly or in combination. These operations are performed periodically or continuously during rolling.

In the above description, the back-up roll crown adjustment device 4 and the work roll bending device 5 are used as shape correction devices for second to fourth order components.
and an intermediate roll bending device 6 was used,
This may be done by operating other devices such as a work roll shift device or an intermediate roll shift device. Further, the relationship between the order of the component and the corresponding one or a plurality of shape modifying devices to be combined may be determined as appropriate depending on the actual situation.

As explained above, according to the present invention, the deviation signal between the detection signal from the shape detector and the target setting value is developed into a fourth-order orthogonal function, and each of the first to fourth orders corresponding to the form of the shape defect is developed. Since the shape modification device to be operated is selected based on the component value, and the shape modification amount corresponding to the component value is performed using the selected shape modification device, not only effective plate shape control can be performed, but also quarter and double Complex elongations such as waves can also be controlled reliably.
This greatly improves the quality and yield of rolled material.

[Brief explanation of drawings]

FIGS. 1A to 1D are explanatory diagrams showing examples of forms of defective shapes, and FIG. 2 is a configuration diagram according to an embodiment of the present invention. In the drawings, 1 is a rolled material, 2 is a multi-stage cluster rolling machine, 3 is a rolling device with a leveling function, 4 is a back-up roll crown adjustment device, 5 is a work roll bending device, 6 is an intermediate roll bending device, 7 is a shape detector, 8 is a calculation device,
9 is a host computer, 10 is an operation panel, A to D are correction signals, E is a target shape setting value, and F is a shape detection signal.

Claims (1)

[Claims] 1 In a multi-stage cluster rolling mill equipped with multiple shape correction devices such as a back-up roll crown adjustment device, a work roll bending device, and an intermediate roll bending device, the amount of displacement in the width direction of the sheet can be changed as a variable in response to the form of shape defects. Each of the first to fourth order functions is determined, and the deviation signal between the detection signal from the shape detector that detects the plate shape on the exit side of the rolling machine and the target shape setting value is expressed as the fourth order function consisting of the above-mentioned functions. Plate shape control for a multi-stage cluster rolling mill characterized by expanding into an orthogonal function, selecting a shape correction device to be operated according to the component amount of each order, and correcting the plate shape by operating according to the component amount. Method.