JPS6015405B2 - Shape control method in strip rolling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shape control method in rolling a strip, and particularly to a method for controlling the shape by setting an arbitrary target shape in a shape control device.

Conventionally, when shape control is performed in strip rolling of thin steel sheets, etc., the goal of control has usually been to always obtain a flat strip.

However, in actual operations, it is not always possible to obtain a flat plate over the entire length of the strip due to the responsiveness of the control system and the accuracy of the mathematical model used, and this results in a considerable amount of rolled products being missed. This may result in a disqualification. In view of the above-mentioned problems, the present invention has been developed by
A method is provided in which a target shape is set within an allowable range depending on the intended use of the rolled product, and the shape is controlled to match the arbitrarily set target shape. Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the shape control device of the present invention, in which 1 is a strip, 2 is a rolling mill, 3 is a winder, 4 is a roll bender, 5 is a deflector roll, and 6
1 is a shape detector, 7 is a signal processing circuit, 8 is a target shape setter, 9 is a shape signal correction circuit, 10 is a shape determination circuit, 11 is a control output circuit, and 12 is a timing control circuit. The shape detector 6 is provided with nine electromagnetic pickups in the width direction of the strip 1, and detects vibrations that are correlated with the shape of the strip 1.

The output signal of the shape detector 6 is applied to the signal processing circuit 7 in nine channels, and these nine channels are applied to the signal processing circuit 7 from one side to the other in the width direction of the strip.
3, D4, C, W4, W3, W2, W,.

An example of the distribution of the output signal of the shape detector is shown in FIG. 2. If the shape of the d strip is expressed as a steepness, the steepness can be expressed by the following equation. QX=kノ(magazine;)2-point2...
......m Here, Sx is the shape detector output signal, Sm
in is the minimum value in the signal Sx, k is a constant, and the subscript x is the position in the strip width direction (channels D, D2, D3, D4
, C, W4, W3, W2, W,). The signal processing circuit 7 calculates the above-mentioned formula [1-] and outputs the result Qx as a shape signal. When the above equation {1-- is calculated from the output signal of the shape detector shown in FIG. 2, the steepness distribution of the strip as shown in FIG. 3 is obtained. Since the present invention sets an arbitrary target shape and performs shape control to match the target shape, in this embodiment, a target shape setting device 8 and a shape signal correction circuit 9 are provided.
From the output signal of each shape detector, the steepness (shape signal) obtained by formula 1 is corrected according to the target shape, and the strip shape is determined from the distribution pattern of the corrected steepness (corrected shape signal) in the strip width direction. is determined, and the operating end of the control is operated based on this determination result.

That is, as the target shape of the strip, relative shape coefficients (relative coefficients regarding steepness in this example) for portions corresponding to each layer (in this example, 9 layers) in the width direction of the strip are determined. is set in the target shape setter 8,
The shape signal correction circuit 9 calculates the shape coefficient as shown in the following equation to obtain the corrected steepness Q'x. Shape coefficients (steepness correction coefficients) k, , k2, k3, k4, k5 are k. <1
, k2=k3=k4=k5=1, and for example, if the middle elongation is relaxed, k,=k2=k
3=k4:1, k5<1.

These shape factors are set by the operator of the rolling mill in a target shape setting device 8 such as a digital switch.

The shape determination circuit 10 holds the output to the control output circuit 11 up to that point if the maximum value (Qmax) of the corrected steepnesses Qx determined by the shape signal correction circuit 9 is within a certain level. When the maximum steepness Qmax exceeds the predetermined level, the shape pattern is determined as follows, and the determination result is output to the control output circuit 11. In other words, when the maximum steepness Q'max exceeds a certain level,
Set a value Q' (n-,) slice levels that are obtained by deviating Qmax by a certain appropriate number n (a natural number of about 3 to 5),
Each corrected steepness Q'x is sliced at each slice level to create a steepness pattern in the strip width direction shown in Table 1 from the corrected steepness distribution shown in FIG.

Table 1 Note that in this embodiment, n=5, and steepness patterns of ranks A to E are created in descending order of steepness.

Although it is possible to immediately determine the pattern of the shape from the steepness pattern in Table 1, in this example, the responsiveness of control operations (for example, roll pending control, adjustment of the movement of the intermediate roll in the bag direction, rolling force control, etc.) is Taking into consideration, only those exceeding an appropriate rank (for example, rank D) among ranks A to E are extracted to create a steepness pattern to be controlled, and the shape is determined by logical judgment as shown in Table 2. judge. Table 2 In Table 2, for example, if the steepness exceeding rank D is only in the center of the strip (hatterns 1 to 5)
If it is determined to be mid-length and only in the thick part of the strip (
Patterns 11 to 13) are determined to be ear waves, and later in the same machine, it is determined to be a one-sided extension (patterns 21 to 23), a simultaneous shape of an ear wave and a middle extension (patterns 31 to 33), etc.

The shape determination circuit 1 outputs Makoto's determination results to the control output circuit 11, and depending on the shape determination results, performs, for example, (a) shape control using a roll bender when an ear wave or mid-elongation occurs alone. In this case, the shape is controlled by rolling down and leveling, and when both the ear wave and middle elongation occur, the output is sent to each control operation terminal (not shown) to perform a combination of control by roll bender and rolling force control.

In actual control operations, when determining the shape from the steepness pattern, it is most effective if the shape is determined from rank A with the highest steepness to ranks B, C, etc., and the control is performed in this order. Shape control is performed sequentially starting from a portion with a large steepness (a portion with a large shape defect), and accurate shape control can be performed. The timing control circuit 12 shown in FIG. 1 is for performing sampling control so as to obtain stable shape control, taking into account the time required for transporting the strip 1 from the rolling mill 2 to the shape detector 6. As described above, in strip rolling, when setting a target shape and controlling the shape, the present invention corrects the shape signal obtained from the output signal of the shape detector on the exit side of the rolling machine according to the arbitrarily set target shape. However, the shape of the strip is determined and controlled from this corrected shape signal, and has the excellent effect that an appropriate target shape can be set and controlled by adding a relatively simple control circuit.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the overall configuration of a control device implementing the present invention, Fig. 2 is a diagram showing an example of the distribution of the shape detector output signal in the strip width direction, and Fig. 3 is a diagram showing the distribution of the shape signal (steepness). FIG. 4 is a diagram showing an example of the distribution of the corrected shape signal (corrected steepness) in the strip width direction. 1... Strip, 2... Rolling mill, 3
... Winding machine, 4 ... Roll bender, 5 ... Deflector roll, 6 ... Shape detector, 7 ... Signal processing circuit, 8 ... Target shape setting device, 9. ...Shape signal correction circuit, 10...Shape determination circuit, 11...
... Control output circuit, 12... Timing control circuit. Figure 1 Figure 2 Figure 8 Figure 4

Claims (1)

[Claims] 1. A method for controlling the shape of a strip during rolling based on an output signal from a shape detector provided on the exit side of a rolling machine, in which the shape of the strip is detected at at least three points in the width direction of the strip. A shape detector is provided, and a relative shape factor is set for each portion corresponding to each position in the width direction of the strip as the target shape of the strip, and is expressed by the following equation from the output signal of the shape detector and the shape factor. The shape signal Qx at each position in the strip width direction and its corrected shape signal Q'x are calculated as follows: Qx=K√((1)/(Smin)
)^2-((1)/(Sx)^2 Q'x=KiQx
Sx: Shape detector output signal Smim: Minimum value in Sx K: Constant Ki: Shape coefficient (i=1, 2,...) Operating the operating end for shape control based on the corrected shape signal. A shape control method in strip rolling characterized by: