JPS5994513A - Method and equipment for controlling automatically sheet width - Google Patents

Abstract

PURPOSE:To control automatically the sheet width of a rolling material, by calculating in sequence a tuning factor in a gauge meter system basing on the dimensional extents of work, the target sheet widths, the sheet thicknesses, the informations about a kind of steel, and the temperatures of a rolling material at vertical rolls and horizontal rolls, and controlling a roll gap of the vertical mill, in a steel sheet rolling equipment. CONSTITUTION:A steel sheet rolling equipment is constituted by incorporating the following items into a control circuit, i.e. a thermometer 9 of a rolling material located just below vertical rolls 2, a host computor 11 which outputs the dimensional extents of work of a vertical mill 2 and a horizontal mill 3 located at the downstream of the mill 2, the target sheet width, sheet thickness, and information of a kind of steel of a rolling material 1, and a turning factor arithmetic setter 10 which calculates in sequence a tuning factor in a gauge meter system by a model method basing on the information of the thermometer 9 and the host computor 11 to output the result to a roll gap correcting value arithmetic device 7. A signal outputted from a load meter 4 is stored in an arithmetic device 6, and is outputted as a load deviation signal to an arithmetic device 7 to calculate a tuning factor optimum for both rolling mills 2, 3 thereby the roll gap of the mill 2 is controlled to control automatically the sheet width of the material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatically controlling the width of a rolled material.

The width accuracy of hot-rolled steel sheets has a significant impact on yield in terms of reducing cold trim allowance and reducing downgrades due to insufficient width, but in recent years, the continuous casting slab ratio has increased, and the slab width has increased. With the adoption of large-width reduction rolling, low-temperature extraction rolling, etc. due to consolidation, the number of factors that worsen strip width accuracy has increased, and the role of strip width control has become extremely important. Factors that cause plate width variations include those based on material properties such as slab care;
Causes include temperature unevenness in heating furnace skid marks, uneven mask rows at the leading and trailing edges caused by width reduction, tension fluctuations between finishing tandem mills, tension fluctuations when winding around the winder, etc., and sheet width. The mechanism by which fluctuations occur is complex. Techniques to prevent such plate width fluctuations include assembly width control (hereinafter referred to as R-AWC) by vertical rolling mill roll width reduction control (hereinafter referred to as R-AWC) in the rough rolling stage and tension control between finishing rolling stands (hereinafter referred to as F-AWC). In response to the recent increase in width variation due to wide width reduction rolling and low temperature extraction rolling, R-AWC with a wide strip width control range is being actively developed.

One of the conventional R-AWC control methods is a gauge meter feedback (hereinafter referred to as GM-FB) method. The GM-FB method will be explained below with reference to FIG. In FIG. 1, numeral 1 indicates a rolled material that progresses in the direction of the arrow. 2 is a vertical roll of a vertical rolling mill, 3 is a horizontal roll of a horizontal rolling mill, 4 is a load meter installed on the vertical roll 2, and 5 is a position detector for measuring the roll opening degree of the vertical roll 2.

The GM-FB method is a gauge meter type W=S+F/M. However, W: Output plate width S: Initial roll gear rough value M: Rolling mill rigidity F: From the load, change the output side plate width variation ΔW from the change in load l. ΔW=-ΔF However, α: Tuning rate ΔF is calculated as the load deviation from the lock-on value, and the roll gear is corrected by ΔW. In Fig. 1, the signal from the load cell 4 is
is inputted into the core device 6 for a certain period of time (
After the lock-on time), the deviation from the stored value is calculated and outputted to the calculation device 7 as a load deviation signal.

In the calculation device 7, the load deviation signal is multiplied by α7M, which is a constant value for plate meat, and the calculation result is outputted to the calculation device 8 as a daily gap correction value.

The arithmetic device 8 adjusts the output of the arithmetic device 7 and the signal from the position detector 5 to control the vertical rolling mill roll opening degree. In such GM-FB method sheet width control, the amount of width reduction on the exit side of the vertical rolls is determined by taking into consideration the deformation in the width direction due to the reduction in the thickness direction by the horizontal rolls 3 located downstream of the vertical rolls. Control. Normally, considering the width expansion after rolling by the horizontal roll 3 and the dogbone width reversal, the tuning rate α is set to 1 so that the pattern of the plate width drive on the vertical roll exit side is opposite to that on the vertical roll 2 side. Set it larger,
Performs minus mill constant control.

However, the biggest problem with the above-mentioned GM-FB method is that the tuning rate α is set to be constant for the plate. In other words, the width fluctuations that occur during thickness rolling by the horizontal rolls 3 following the width rolling by the vertical rolls 2 include width expansion and dogbone width reversal, and both factors depend on the temperature, absolute width, and thickness of the rolled material. It is a complex function of width reduction, steel type, etc. For example, regarding the width expansion rate (width expansion amount/horizontal reduction f), the plate width ratio (absolute width/thickness)
As the temperature increases, the width expansion rate decreases, and as the temperature increases, the width expansion rate increases. Regarding width retraction, as the plate width ratio and width reduction amount increase, the width retraction amount increases, and as the temperature increases, the width retraction amount tends to decrease. For this reason, if there is a temperature change in the plate thickness, the amount of width expansion, de, and back width will vary, so in tuning rate setting control with a constant plate thickness, the plate width after horizontal roll rolling is adjusted to corner accuracy. difficult to control.

The present invention has been made to advantageously solve these problems, and its gist is to control the amount of width reduction of the vertical rolling mill based on the signal from the load cell installed in the vertical rolling mill. In feedback automatic strip width control, which calculates the tuning rate using a gauge meter method, the tuning rate in the gauge meter method is calculated based on the signal from the thermometer that measures the temperature of the rolled material directly below the vertical rolling mill, and the signal from the vertical rolling mill and downstream thereof. An automatic plate width control method, which calculates using a model formula based on the amount of dimensional processing in a horizontal rolling mill located, the target plate width, plate thickness, and steel type of the rolled material, and sequentially changes and sets the plate thickness. , and a feedback automatic strip width control device that calculates the width reduction control amount of the vertical rolling mill using a gauge meter method based on signals from a load cell installed in the vertical rolling mill. A thermometer that measures the temperature of the rolled material, a host computer that outputs the dimensional processing amount of the vertical rolling mill and the horizontal rolling mill located downstream thereof, the target strip width, thickness, and steel type information of the rolled material, and the thermometer. signal and
The present invention relates to an automatic plate width control device characterized by being provided with a tuning rate calculation setting device that sequentially calculates the tuning rate in a gauge meter type using a model type based on information from a host computer.

In other words, in summary, the present invention focuses on the fact that when there is a temperature fluctuation in the plate thickness, the amount of width expansion and dogbone width retraction differs, and the amount of dimensional processing with vertical rolls and horizontal rolls,
In addition to the target plate width, plate thickness, and steel type information, the temperature of the rolled material is added to the model formula as a factor, and the tuning rate in the gauge meter formula is calculated sequentially, and the vertical roll opening in the plate thickness is calculated based on the results. It is configured to perform changing control. Next, embodiments of the present invention will be explained with reference to the drawings.

FIG. 2 shows the configuration of an apparatus according to an embodiment of the present invention, and since the numbers 1 to 8 in the figure are the same as those in FIG. 1, their explanation will be omitted. However, in the example of the present invention, there is a thermometer 9 that measures the temperature of the rolled material directly below the vertical roll 2, the dimensional processing amount of the vertical rolling mill 2 and the horizontal rolling ta3 located downstream thereof, the target width of the rolled material, and the thickness of the rolled material. ,
Tuning that sequentially calculates the tuning rate in the gauge meter type using a model formula based on the information from the host computer 11 that outputs steel type information, the thermometer 9, and the host computer 11, and outputs it to the roll gap correction value calculation device 7. The rate calculation setting device 10 is incorporated into a control circuit. Load cell 4
The load signal is stored in the arithmetic unit 6 after a certain period of time after the start of rolling, and thereafter the load deviation from the stored value is calculated and output to the arithmetic unit 7 as a load deviation signal. In the calculation device 7, α7M is used as the load deviation signal.
The tuning rate is multiplied in the form (M' is the estimated rolling mill stiffness IrIL). This tuning rate is set by the tuning rate calculation setting device 10, which receives the signal from the thermometer 9 that measures the temperature of the rolled material directly below the vertical roll 2 and the rolled material given from the host computer 11. The optimum tuning rate is calculated using a model formula from the target plate width, plate thickness, steel type, width and thickness reduction amount in the vertical rolling mill 2 and the horizontal rolling mill 3 located downstream thereof, and is set sequentially based on the plate thickness. Control board width.

Here, the model equation in the tuning rate calculation setting device 10 will be explained.

In order to control the strip width, the vertical roll gap is changed to change the etching amount ΔE, but the strip width after horizontal roll rolling can be changed with a certain influence coefficient depending on the etching amount ΔE.

ΔW=Kt·ΔF (where ΔW is the amount of change in strip width after horizontal roll rolling) The amount of strip width change to be controlled can be determined by the following formula in the case of the gauge meter method.

ΔW = K 2 · ΔF (ΔF: Vertical roll rolling load change amount) The etching amount ΔE obtained from the above two formulas is 2 ΔE = -ΔF 1 The Km/Kl of the above formula is the tuning rate in the gauge meter method. becomes. 1 for the influence coefficient is temperature, rolled material size,
It is a function of steel type, etc., and the simplest example is 1 = (A1 + A2 '1' + As ''/H + A4
Ceq ), and it can be seen that the tuning rate is expressed as a function of temperature, rolled material dimensions, and M types.

Also, consider the case where a vertical rolling mill and a horizontal rolling mill that do not perform AIC are installed downstream. The amount of width variation ΔW' caused by rolling in the downstream stand is expressed as ΔW' = KsΔF. Here, the constraint is expressed as a function of temperature, rolled material dimensions, steel type, and amount of etching in the downstream stand.To give the simplest example, 3 = (Bt + B2 T + B3 W/H + B4
Ceq +BsΔE').

Summarizing the above equation and the above-mentioned equation, it can be seen that the required etching amount is ΔW+ΔW'=KtΔE×ΔF, and the tuning rate is calculated based on the temperature, material dimensions, steel type, etching amount of the downstream stand, etc. The output of the calculation device 7 is inputted to the calculation device 8 as a roll gap correction value, and compared with the signal from the vertical roll position detector 5, the opening degree of the vertical roll 2 is automatically controlled by the deviation, thereby improving accuracy. High plate width control is performed.

Further, in the case where vertical rolls and horizontal rolls that are not subject to automatic strip width control are installed further downstream of the strip width control vertical rolls and horizontal rolls, and it is desired to obtain a predetermined strip width after rolling by them, Qi-Yung rate calculation setting device 1
When calculating the optimum tuning rate at 0, the upper level calculator 11 calculates the optimum tuning rate by taking into consideration the width reduction amount and thickness reduction amount in the downstream vertical rolls and horizontal rolls, and sends the result to the calculation device 7. By setting this, highly accurate board width control becomes possible.

Although described in detail above, the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention. Therefore, the present invention can significantly improve the strip width control accuracy compared to the conventional control method and device, and can improve the yield of hot rolled steel plates accordingly, and requires only a small amount of equipment in the conventional side leg device. It can be easily implemented by adding improvements through investment.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view showing a conventional gauge meter feedper method and apparatus for controlling sheet width, and FIG. 2 is an explanatory view showing a control method and apparatus according to the present invention. l: Rolled material, 2: Vertical roll, 3: Horizontal roll, 4: Load cell, 5: Position detector, 6: Arithmetic device, 7: Arithmetic device, 8
: Arithmetic device, 9: Thermometer, 10: Tuning rate calculation setter, 11: Upper level computer. Applicant Nippon Steel Corporation

Claims (2)

[Claims] (1) In feedback automatic strip width control that calculates the width reduction control amount of the vertical rolling mill using the gauge meter method based on the signal from the load cell installed in the vertical rolling mill, the tuning rate in the gauge meter method is used. , the signal of a thermometer that measures the temperature of the rolled material fA directly below the vertical rolling mill, the amount of dimensional processing in the vertical rolling mill and the horizontal rolling mill located downstream thereof, the target strip width of the rolled material, and the An automatic plate width control method characterized by calculating using a model formula based on the thickness and steel type, and sequentially changing and setting the plate thickness. (2) In the feedback automatic strip width control device that calculates the width reduction control amount of the vertical rolling mill using a gauge meter method based on the signal from the load cell installed in the vertical rolling mill, A thermometer that measures the temperature of the rolled material, a vertical rolling mill, a horizontal rolling mill located downstream thereof, a host computer that outputs the dimensional processing amount, target width, thickness, and steel type information of the rolled material, and the temperature An automatic sheet width control device characterized by being provided with a tuning rate calculation setting device that sequentially calculates the tuning rate in a gauge meter type using a model type based on a gauge signal and information from a host computer.