JPS62292211A - Automatic shape control method for rolling material - Google Patents

Abstract

PURPOSE:To prevent a bias elongation of a rolling material and to obtain an excellent shape of the rolling material by controlling the shape of the rolling material based on conditions of a coil weight and a winding tension. CONSTITUTION:According to an elongation percentage in the width direction detected by a shape detector 6, A1 indicating a size of a primary component and A2 indicating a size of a secondary component are acquired by a shape arithmetic unit 8. Then, by a controller 9b and a roll bending device 4, a bending force of work rolls 3 is controlled to make A2 to zero. As for A1, by a correcting arithmetic unit 13, the coil weight W wound on a winding reel 7 is calculated momentarily from a plate velocity (v) detected by a plate velocimeter 11, the plate width B and a finished plate thickness (h). From a tension T detected by a tension meter 12 and the value of A1 caused by a deflection of the winding reel 7 generated by the coil weight W are calculated to make this value as AS. Admitting the obtained AS as a target value, a working side and a driving side of the rolling reducing apparatus 5 is controlled by a controller 9a to allow to equalize the primary component A1 obtained by the shape arithmetic unit 8 with AS.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a control method for automatically controlling the shape of a rolled material rolled by a rolling mill.

<Prior Art> A conventional automatic shape control method will be explained based on FIG. 4, which is a block diagram of an automatic shape control device installed in a four-high rolling mill.

In the figure, 1 is a rolling mill, 2 is a backup roll, and 3 is a rolling mill.
4 is a work roll, and 4 is a roll bending device that applies a pending force to the work roll 3 to control the shape of the rolled material 10. 5 is a reduction device, 6 is a shape detector, and 7 is a take-up reel. Further, 8 is a shape calculation device, and the tension distribution σ in the width direction of the rolled material 10 detected by the shape detector 6
1, the elongation weight distribution βm is determined by the following equation (1).

β1 = Gi Nishi ...... (1) E β, 2 radial stretch in the width direction Sufficient fabric 017 Tension distribution in the width direction kg/mm20: Average tension kg/mm"E: Young's modulus kg
/IIl[12 Next, the magnitude AI of the first-order component and the magnitude A2 of the second-order component are determined from β1. As shown in the figure, A□ represents asymmetrical elongation, and A2 represents symmetrical elongation. A method for finding A, , A2 from β1 is, for example, a method of finding them using orthogonal functions (Japanese Patent Application No. 6O-9798
0), and a method of calculating using a power series (Japanese Patent Application Laid-open No. 1983
-19401). Further, numeral 98 in the figure is a controller, which drives the lowering device 5 so that the above-mentioned A becomes zero. For example, if the elongation on the driving side and the working side are asymmetrical and the elongation on the driving side is large, the reduction on the driving side is released and the working side is reduced so that A1 becomes O. 9b is also a controller, and the above-mentioned A
The roll bending device 4 is driven so that 2 becomes 0. For example, in the case of edge elongation in which both ends of the rolled material IO are too elongated, the roll bending device 4 is driven in the direction of increasing the convex crown of the work roll 3, and controlled so that A2 becomes 0 to create a flat shape. obtain.

<Problem that the invention seeks to solve> The automatic shape control device described above has the following drawbacks.

That is, as shown in FIG. 5, the take-up reel 7 receives the weight of the coil 7a by supporting the mandrel 7b with a bearing 7C and a tip support 7d, but the tip support 7d is retracted when the coil 7a is extracted. Because of this structure, as shown in the figure, there is a gap between the tip support 7d and the mandrel 7b, so that it is not a completely rigid body.

Therefore, due to the weight of the coil 7a, which is normally about 20 to 40 tons, the mandrel 7b bends approximately as a cantilever beam with the bearing 7C as a fulcrum. As a result, as shown in FIG. 6, the tension distribution on the working side and the driving side is no longer uniform. Since the shape detector 6 calculates the elongation weight distribution using Equation 11 as described above, it recognizes the tension difference due to the deflection H of the winding rule 7 as one-sided elongation, and the automatic shape control device calculates the elongation weight distribution as described above. In order to drive the lowering device 5 so that A1 becomes O,
As a result, the working side is slightly stretched to make the tension distribution uniform.

Further, the amount of one-sided elongation increases with the weight of the coil 7a, that is, with the rolling time. According to the actual measurement data, the weight of the coil 7a is 1
With a change of 5 tons, the AI increases at a rate of approximately tx+o-', which is a value that cannot be ignored. Furthermore, deflection due to the (constant) tension acting on the take-up reel 7 has a similar effect.

A shape detector 6 installed between the rolling mill 1 and the take-up reel 7
In the rolling mill 1, which automatically controls the shape of the rolled material 10 using signals, when the take-up reel 7 is deflected due to the weight of the coil 7a and the winding tension, the shape detector 6 detects that the actual rolled material 10 is flat. Even if there is one, it is detected as a one-sided extension signal. As a result, this signal is fed back to the shape detector 6, and the rolled material IO that is elongated on one side is rolled instead.

The present invention has been made in view of the above circumstances, and provides an automatic shape control method for controlling the shape of a rolled material based on the state of the coil weight and winding tension. The purpose is to eliminate detection errors caused by deflection of the take-up reel and obtain a good rolled material shape.

<Means for Solving the Problems> The method of the present invention for achieving the above object detects the shape of the rolled material using a signal from a shape detector of the rolled material installed between the rolling mill and the coil winding machine. In an automatically controlled rolling mill, the shape detection error of the rolled material due to the coil weight and winding tension is calculated, and the calculation result is applied to the automatic control system of the rolled material in order to prevent one-sided elongation of the rolled material. It is characterized in that it is input as a correction signal to.

Determine the instantaneous values of the coil weight and take-up tension, and use these values to determine the amount and direction of deflection of the take-up reel. Furthermore, the momentary value of the amount of one-sided elongation of the rolled material due to the deflection of the take-up reel is determined, and this value is used as a correction signal for the automatic shape control system.

<Embodiment> Fig. 1 is a block diagram of an automatic shape control device in a four-high rolling mill that implements an embodiment of the method of the present invention, and Fig. 2 is a conceptual diagram showing the load acting on the take-up reel. , FIG. 3 is a conceptual diagram showing the deflection of the take-up reel. Incidentally, the same members as those shown in FIG. 4 are given the same reference numerals and redundant explanations will be omitted.

In the figure, reference numeral 14 denotes a one-sided elongation prevention device, which is composed of a plate speed meter 11 attached to the shape detector 6, a tension meter 12 that calculates the tension of the rolled material from the current of the take-up reel 7, and a correction calculation device 13. has been done.

The operation of this device is based on the elongation weight distribution in the board width direction detected by the shape detector 6, and the shape calculating device 8 calculates A1 representing the magnitude of the first-order component and A1 representing the magnitude of the second-order component.
Find 2. Here, A and A2 are determined by orthogonal functions and power series. Next, the pending force of the work roll 3 is controlled by the controller 9b and the roll bending device 4 so that A2 becomes zero. Regarding A1, the correction calculation device 13 momentarily calculates the coil weight IIW wound on the take-up reel 7 from the plate speed V detected by the plate speed meter 11, the plate width B, and the finished plate thickness, and also calculates the coil weight IIW wound on the take-up reel 7 from time to time. Tension T and coil weight W detected by 12
The amount of A1 caused by the deflection of the take-up reel 7 caused by is calculated from time to time, and this (ff is assumed to be A8. Tension T
To obtain A8 from the coil weight W, as shown in FIG. 2, the tension T and the coil weight '! T-direction component W° of lW
From this, the difference δ8-δ0 between the working side and the driving side in the amount of deflection of the take-up reel 7 in the W' direction is determined as shown in FIG. That is,
Assuming that the deflection of the mandrel 7b of the take-up reel 7 is approximately a straight line as shown in FIG.
W−δD can be obtained.

δ0−δo=−L6δ0 lc =1−・k, ・(W' −T) 1c −AL−・k, ((W+Wo) sin θ−T) Lc =1 + ((Shingomushi dt+Wo) Sinθ−T ))−
11) iLc60X 10 where lc is the distance to the center of mandrel 7b, B is the plate width, and δ. Let be the bending acid at the center of the mandrel 7b, kl be the bending stiffness at the center of the mandrel 7b, θ be the angle between W and Wo, and Wo be the own weight of the mandrel 7b.

Here, θ changes depending on the coil diameter, but is approximately a constant value.

When the distance between the shape detector 6 and the take-up reel 7 is L, the elongation rate difference A8 between the working side and the driving side can be expressed by equation (2).

However, let α be the gain adjusted to the optimum value through experiment.

That is, the distance J to the center of the mandrel 7b is a constant.
2c, the bending rigidity at the center of the mandrel 7b is 1, and the dead weight of the mandrel 7b is W. , by giving the angle θ between W and Wo in advance, giving the plate width B and finished plate thickness of the rolled material IO as the rolling conditions, and giving the momentary values of the plate speed V and the winding tension T, (11 , +21 equation, the elongation rate difference between the working side and the driving side can be determined from time to time.

For simplicity, we have assumed that θ formed by W and Wo is a constant value, but this can be done by calculating the coil diameter from time to time from the sill plate thickness and plate speed V. You can also find it and use it.

As obtained in the above manner, As is set as a target value, and the controller 9a controls the amount of reduction on the work side and drive side of the reduction device 5 so that the primary component A1 obtained by the shape calculation device 8 becomes equal to A8. That is, the weight of the coil increases with the passage of rolling time, resulting in a difference δ in the amount of deflection between the working side and the driving side. Even if -δ0 increases, δW-δ can be maintained by giving A8 obtained by equation (2) as the target value. It is possible to generate a tension difference corresponding to . In other words, δ
W-δ. = 0, rolling can be performed to obtain a flat rolled material lO.

Although the above-mentioned embodiment shows an example of a four-high rolling mill, the present invention is not limited to a four-high rolling mill and can be applied to a general rolling mill.

<Effects of the Invention> The automatic shape control method for a rolled material of the present invention controls the shape of the rolled material based on the coil weight and the state of the winding tension. Detection errors caused by deflection of the reel can be eliminated. As a result, it is possible to prevent one-sided elongation of the rolled material and to obtain a good shape of the rolled material.

[Brief explanation of the drawing]

Figure 1 is a block diagram of an automatic shape control device in a four-high rolling mill that implements an embodiment of the method of the present invention, Figure 2 is a conceptual diagram showing the load acting on the take-up reel, and Figure 3 is a A conceptual diagram showing the deflection of the reel, Fig. 4 is a block diagram of the automatic shape control device in a conventional four-high rolling mill, Fig. 5 is a structural diagram of the take-up reel, and Fig. 6 shows the tension due to the deflection of the take-up reel. It is a conceptual diagram showing distribution. In the drawings, 1 is a rolling machine, 2 is a backup roll, 3 is a work roll, 4 is a roll bending device, 5 is a rolling device, 6 is a shape detector, 7 is a take-up reel, 8 is a shape calculation device, 10 is a rolling machine 11 is a plate speed meter, 12 is a tension meter, and 13 is a correction calculation device.

Claims (1)

[Claims] In a rolling mill in which the shape of the rolled material is automatically controlled by a signal from a shape detector of the rolled material installed between the rolling mill and the coil winder, the shape of the rolled material due to the coil weight and winding tension is An automatic shape control method for a rolled material, comprising calculating a shape detection error and inputting the calculation result as a correction signal to an automatic shape control system for the rolled material in order to prevent uneven elongation of the rolled material.