JPS62148011A - Plate width control device for hot strip mill - Google Patents

Abstract

PURPOSE:To reduce variations in the plate width of a rolled stock by installing a range finder in each outlet side of a vertical and a horizontal rolling mill and separately evaluating errors in the width reducing model and the width spreading model. CONSTITUTION:Plate width meters (range finders) 7, 8, and 4 are installed at opposite sides of a rolling stock 1 to face each other in each outlet side of a vertical rolling mill 3 and a horizontal rolling mill 2 of a hot strip mill consisting of the mills 3 and 2. Variations in the plate width in the outlet side of the mill 3 are obtained at every constant sampling time based on measurements from the meters 7, 8, and 4 and the set plate, thickness. A width reducing model parameter and a width model spreading parameter are separately determined based on the above variations and a roll opening changing amount of the rolling mill is corrected. In this mechanism, the quality of rolled stocks is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control device for plate #A of a hot strip mill.

<Prior Art> Fig. 2 shows a part of a conventional hot strip mill rough rolling mill row. As shown in the figure, the rolled material 1 is fed in the direction of the arrow and rolled down in the width direction by a vertical rolling mill 3, and then rolled down in the thickness direction by a horizontal rolling mill 2.

When a rolled material 1 having a rectangular planar shape is rolled by a vertical rolling mill 3 and a horizontal rolling mill 2, as shown in FIG. A width variation occurs in which the rear end width spreads 12 are superimposed. Width control is a circle that takes into account width fluctuations or temperature fluctuations on the entrance side of the vertical rolling mill, and the deformed layer is predicted from a width drop model and a width widening model, and the vertical rolling mill roll opening degree is changed over the entire length of the rolled material. It is. Conventionally, in order to improve the accuracy of the model, a method has been adopted in which the model is corrected using the detection results of the strip width meter 4 installed on the exit side of the horizontal rolling mill.

<Problems to be Solved by the Invention> However, as shown in Figure 3, the width variation at the exit side of the horizontal rolling mill is a combination of width drop and width widening, so the accuracy of the width drop model and width widen model is low. It is difficult to distinguish and evaluate these.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a strip width control device for a pot strip mill that can reduce unsteady cotton strip width fluctuations, thereby improving the quality of rolled material.

<Means for Solving the Problems> The configuration of the present invention for achieving the above object includes a vertical rolling mill and a horizontal rolling mill.In the hot strip, a measuring device for measuring the vertical distance from the side surface of the rolled material is installed. It is characterized in that the vertical rolling mill and the horizontal rolling mill are installed facing each other on the outlet side with the rolled material sandwiched therebetween.

<Operation> The measuring instruments installed on the exit side of the vertical rolling mill and horizontal rolling loss detect the strip width fluctuations on the exit side of the vertical rolling mill and horizontal rolling mill, so the width drop model and width widening model are corrected. By adjusting the amount of change in the roll opening of the vertical rolling mill, unsteady cotton board width fluctuations can be reduced.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Incidentally, the same parts as those in the prior art described above are given the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows an embodiment of the present invention. As shown in the figure, on the exit side of the vertical rolling mill 3, plate width gauges 7 and 8 are installed on the rolled material 1.
They are arranged vertically facing each other with the two sides in between.

FIG. 4 shows an example of the signal from the strip width meter on the outlet side of the vertical rolling mill 3. 13
14 is a signal when the vertical rolling mill roll opening is constant, ie, width control is not performed, and 14 is a signal when width control is performed. Reference numeral 15 indicates an unsteady portion at the leading end, numeral 17 represents an unsteady portion at the rear end, and numeral 16 represents a regular portion that does not cause drop-off or widening. Leading and trailing end width drop amounts ΔW, ΔW and leading and trailing end width expansion amounts Δω1. The width reduction model and width expansion model for predicting Δω8 are given by the following equations.

ΔW = Fu, (Wo, W,, To, D,) ・・−
(1) ΔW, = Fo (Wo, Wl, To, DE) ・
...(2)ΔωT=F T (W2"TO'
T3' DH) ... (3) ΔωB" F B
(W2', TO'T3"H)...(
4) However, Wo is the strip width at the entrance of the vertical rolling mill, W is the roll opening preset value of the vertical rolling mill, %'l is the strip width at the entrance of the horizontal rolling mill, To is the strip thickness at the entrance of the vertical rolling mill, and T3 is the horizontal rolling mill. The exit plate thickness, D6 is the vertical rolling mill roll diameter, and DH is the horizontal rolling mill roll diameter.

When width control is not performed, the above-mentioned ΔW and ΔWI.

can be directly detected as 18.19 shown in FIG. 4 using the board width gauges 7 and 8. Normally, the values of the parameters included in formulas (1) to (4) are determined by stratification based on steel type, plate thickness, plate width, etc. Example: For a round bar, the amount of width drop detected with a total board width of 7°8 and Wo
, Wl, To, Dll: can be determined by stratifying and accumulating the setting values and performing regression. In addition, since the width expansion is given by the difference between the strip width on the exit side of the horizontal rolling mill and the strip width on the input side, the detection result of the strip width meter 5.7.8 and T.

T3. The width spread model parameters are determined by regression from the set value of D. Since the amount of width drop is the difference in plate width between the leading and trailing edges of the steady part and the unsteady part when the vertical rolling mill roll opening is constant, the above value cannot be directly detected when width control is performed. Therefore, the width drop model parameter 7 is determined by fitting the sheet width actual value at each point of the unsteady part detected at every fixed sampling time with the following function.

X Fu, (wo(il, W, (i), ′rO,
D, )However, LT has a longer tip width and length (Fig. 4 15), L
B is the width drop length at the rear end (Fig. 4, 17), Lo is the total length of the rolled material, is the vertical rolling mill roll opening actual value, and 1 is the sample number.

In addition, the width expansion model parameters are determined in a similar manner.

<Effects of the Invention> As explained above in detail based on the examples, the strip width control system of the hot strip mill of the present invention detects strip width fluctuations on the exit side of the vertical rolling mill, and uses the width drop model and Since errors in the width expansion model can be distinguished and evaluated, fluctuations in the width of the rolled material can be reduced. As a result, the quality of the rolled material can be improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of a conventional hot strip mill, Fig. 3 is an explanatory diagram of width drop and width widening, and Fig. 4 is an explanatory diagram of the width gauge signal. Figure 2 is a graph showing an example. In the drawing, 1 is a rolled material, 2 is a horizontal rolling mill, 3 is a vertical rolling mill, 4.5 and 7.8 are plate width gauges, and 6 is a thermometer.

Claims (1)

[Claims] In a hot strip consisting of a vertical rolling mill and a horizontal rolling mill, a measuring device for measuring the vertical distance from the side surface of the rolled material is inserted between the rolled material on the exit side of each of the vertical rolling mill and the horizontal rolling mill. A strip width control device for a hot strip mill characterized by being installed facing each other.