JPS63212007A - Non-interfering control method for sheet thickness and shape in multiroll rolling mill - Google Patents

Abstract

PURPOSE:To improve the sheet shape accuracy as well as the sheet thickness accuracy by controlling shift quantity of a taper roll by controlling pressing increments of a backup roll, calculating predictive sheet thickness variation amounts, and also controlling rolling roll drafts. CONSTITUTION:A sheet thickness controller 8 calculates a rolling roll drafting quantity based on a signal (a) from a thickness gage 7 and a signal (b) from a rolling load detection means, outputs a signal (c), and controls a roll drafting means. On the other hand, a shape controller 9 calculates a pressing increment quantity of a backup roll and a shift quantity of a taper roll based on a signal (d) from a shape detector 6, outputs control signals (e), (f), and controls a backup roll pressing means and a taper roll shifting means to the extent of the above calculation quantity. A noninterfering controller 10 calculates a predictive sheet thickness variation amount based on the signal (b) from the rolling load detection means and the control signal (e) for the pressing increment from the controller 9. The noninterfering controller 10 outputs a control signal (g) based on the calculated thickness variation quantity to draft the rolling roll.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to the control of sheet thickness and shape in a multi-high rolling mill that performs automatic sheet thickness control and automatic shape control during thin sheet rolling using, for example, a 12-high or 20-high rolling mill. It is related to non-interference control methods.

(Conventional technology) In recent years, in rolling thin plates of copper alloys, etc., in order to meet the demand for product thickness accuracy, not only automatic plate thickness control is performed in multi-high rolling mills, but also shape (flatness) ) Automatic shape control methods have been developed to meet the growing demand for high accuracy. However, shape control using this method also involves changes in plate thickness, so non-interference (compensation) control between plate thickness and shape is required.

By the way, regarding conventional four-high rolling mills or six-high rolling mills in which the push amount of the backup roll and the shift amount of the tapered roll can be changed, the following two control methods intended for the above-mentioned non-interference control are known.

The first method is to predict the change in plate thickness due to roll bending in a rolling mill equipped with a roll bending mechanism, and control the rolling reduction amount of the rolling mill using a predetermined calculation formula.
This is designed to correct changes in plate thickness due to roll bending (Japanese Patent Laid-Open No. 60-96319).

The second method is to detect the pushing force or amount of extrusion applied to the work roll by the horizontal bending device in a rolling mill equipped with a horizontal bending device, and based on this detection result, set the pressure on the piston for back-up roll pressure. The position is corrected (Japanese Unexamined Patent Publications Nos. 60-3908 and 60-3909).

(Problems to be solved by the invention) No. 1 above. Considering the case where the second method is applied to a multi-high rolling mill, in the first method, there are several places (4
~6 locations), it is not possible to make predictions based on the amount of bending.

Furthermore, in the second method, there is a problem in that the maintenance of each sensor and the signal processing become complicated if the pressing force or its amount is detected and controlled for each pressing amount.

(Means for Solving the Problems) In order to solve the above problems, the present invention uses a plate thickness control device to control the roll reduction, and a shape control device to control the movement of the tapered roll and the increment of pushing of the backup roll. At the same time, the non-interference control device calculates the predicted plate thickness change amount Δh based on the above control using a predetermined arithmetic formula, and performs roll reduction control by this predicted plate thickness change amount Δh in addition to the above control. did.

(Example) Next, an example of a method for non-interfering control of plate thickness and shape in a multi-high rolling mill according to the present invention will be described.

1 and 2 show a 20-high rolling mill to which the control method according to the first embodiment of the present invention is applied. A first intermediate roll 3, which is a tapered roll, and a second intermediate roll 4. A backup roll 5 is provided, and a shape detector 6 and a plate thickness gauge 7 are provided above and below the rolled material 1 at a position slightly downstream from the roll group.

and plate thickness control device 8. The shape control device 9 and the non-interference control device IO are configured to perform non-interference control of plate thickness and shape as described below.

Next, details of control by each of the above-mentioned control devices will be explained.

First, the plate thickness control device 8 calculates the amount of reduction required by the roll group reduction means (not shown) based on the signal a from the plate thickness gauge 7 and the signal from the rolling load detection means (not shown).
The control signal C is outputted to control the roll group lowering means to operate by this amount.

On the other hand, the shape control device 9 determines, based on the signal d from the shape detector 6, the pushing increment amount ΔxH (i=1
. . . n) and the backup roll pushing means, the taper roll moving means (also not shown) is calculated so as to calculate the movement amount Δ2 required for the tapered roll moving means (not shown), output the control signals e and f, and operate by the above calculated amount. Controls the roll movement means.

Further, the non-interference control device IO controls the rolling wedge, which is the roll group rolling means (not shown), based on the signal e from the rolling load detection means and the control signal e regarding the increment amount ΔXi of pushing from the shape control device 9. amount of reduction,
That is, the predicted plate thickness change amount Δh1 is calculated using the following formula.

Δh,=ΣF,(P,W)−Δxi=−(1)i=
In addition, P: Rolling load corresponding to the above-mentioned signal W: Strip width Further, the functions F and (P, W) are determined theoretically or experimentally.

The predicted plate thickness change amount Δh+ is a predicted plate thickness change amount that varies according to the control of the backup roll 5 described above, and the non-interference control device 10 outputs a control signal g based on equation (1). Then, the reduction wedge is used to reduce the thickness by the predicted plate thickness change amount Δh. That is, by rolling down the rolling wedge, automatic shape control is performed independently of automatic plate thickness control, and plate thickness fluctuations do not occur.

FIG. 3 shows the relationship between the pushing amount of the backup roll 5 and the increased plate thickness.Compared to the broken line indicating the case where no control is performed by the non-interference control device 10, the solid line indicating the case where the control is performed shows the plate thickness. Almost no changes have occurred.

FIG. 4 shows the relationship between the pushing amount of the backup roll 5 and the increased rolling load, and the solid line showing the case where the control is performed has almost no rolling load compared to the broken line showing the case where the control by the non-interference control device 1O is not performed. There is no fluctuation, and therefore there is almost no interference with automatic plate thickness control.

FIG. 5 shows a control method according to a second embodiment of the present invention.
This figure shows a 0-high rolling mill, and is substantially the same as in FIG. 1 except for some of the contents of the control signals, so corresponding parts are given the same numbers and their explanation will be omitted.

That is, in this second embodiment, the control signal e is input manually to the non-interference control device lO, and the deformation resistance R and the rolling reduction rate γ of the rolled material l are controlled by means not shown.
is input into the non-interference control device 10 by the work sound or automatically, and the predicted plate thickness change amount Δh is calculated using the following calculation formula.

Δh,=ΣFi(Z,W)−Δxi=−(2)i=direction,Z=RXγ Furthermore, the functions F and (Z, W) are determined theoretically or experimentally.

Then, based on this predicted plate thickness change amount Δh, the reduction wedge is controlled in the same manner as in the first embodiment.

(Effects of the Invention) As is clear from the above description, according to the present invention, the plate thickness control device controls the roll reduction, and the shape control device controls the movement of the tapered roll and the increment of pushing of the backup roll. The predicted plate thickness change amount Δh based on the above-mentioned control is calculated by a non-interference calculating machine using a predetermined calculation formula, and the roll reduction control is performed in addition to the above-described control by this predicted plate thickness change amount Δh.

For this reason, automatic shape control is performed independently of automatic plate thickness control.
In addition, it is possible to prevent plate thickness fluctuations, and as a result, it is possible to freely increase the pushing amount of the backup roll even during rolling, and to improve the plate thickness accuracy and shape (flatness) accuracy of the rolled plate through rapid and wide-ranging shape control. This has the effect of improving both.

[Brief explanation of the drawing]

FIG. 1 shows the control method according to the first embodiment of the present invention.
A block diagram of the 0-high rolling mill, Figure 2 is a schematic partial cross-sectional view of Figure 1, Figure 3 is a diagram showing the relationship between the amount of push-in of the backup roll and the increased plate thickness, and Figure 4 is the amount of push-in of the backup roll. FIG. 5 is a block diagram of a 20-high rolling mill to which the control method according to the second embodiment of the present invention is applied. 3... First intermediate roll, 5... Backup roll, 8... Thickness control device, 9... Shape control device, IO.
...Non-interference control device. Patent Applicant: Kobe Steel, Ltd. Agent Patent Attorney: 2 persons, Figure 1, Section 2, Section 4, Section 5

Claims (3)

[Claims] (1) While the thickness control device controls the roll reduction, the shape control device controls the movement of the tapered roll and the increment of push of the backup roll, and the non-interference control device controls the predicted thickness change Δh based on the above control. Calculated using a predetermined calculation formula, this predicted plate thickness change amount Δ
A method for non-interfering control of plate thickness and shape in a multi-high rolling mill, characterized in that in addition to the above control, control is performed to reduce the roll by h. (2) Claim 1, characterized in that the above calculation formula is Δh=Σ_iF_i(P,W)·Δx_i F_i(P,W): a function of the detected rolling load P and plate width W. A non-interferential control method for plate thickness and shape in a multi-high rolling mill described in . (3) The above calculation formula is Δh=Σ_iF_i(Z,W)・Δx_i F_i(Z,W): Product of deformation resistance R of rolled material and rolling reduction rate γ Z=R×γ and a function of sheet width W A method for non-interfering control of plate thickness and shape in a multi-high rolling mill according to claim 1.