JPH0653283B2 - Adaptive control method in rolling mill - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adaptive control method in a rolling mill, and in particular,
The present invention relates to an adaptive control method suitable for rolling an ultrathin plate.

[Conventional technology]

As described in Japanese Patent Publication No. 49-2273, a conventional rolling load type adaptive control method first performs a rolling load prediction calculation using formula (1), However, P _Ci ; rolling load calculation (prediction) value K _fi ; average deformation resistance b _i ; strip width R ′ _i ; flat roll radius Δh _i ; reduction amount Q _i ; reduction force coefficient (note index i is the i-th A stand is shown. The same applies to the following.) The rolling position S _i of the work roll is calculated by the following formula (2) from the predicted rolling load, and is set in the rolling mill controller.

However, h _i; rolling mill exit side thickness P _Ci; rolling load prediction value S _0i; pressure at the zero adjustment position Next, results when actually rolled (rolling reduction, roll speed, etc.) (1) to By substituting the calculated rolling load value P _CAi , the ratio Z _i between the calculated rolling load value P _CAi and the actual rolling load value P _Ai is calculated by the equation (3).

The expression (1) usually includes deformation resistance, an error in the friction coefficient, etc., and Z _i in the expression (3) does not become 1,0.

When rolling the next material with the same steel type, Z _i obtained by the equation (3) is used and the rolling load predicted value P _Ci is obtained by the equation (4).

However, Z _i ; the correction coefficient obtained by the equation (3) was calculated by substituting the rolling load predicted value P _Ci obtained by the equation (4) into the equation (2), and the rolling position S _i was obtained and set.

FIG. 2A shows a state where the work rolls 1 of the rolling mill are not in contact with each other. Equations (1) and (4) are
This is a calculation formula calculated on the assumption that the product is rolled in this state.

[Problems to be solved by the invention]

However, in the case of ultra-thin sheet rolling, the end portions of the work rolls may come into contact with each other, as shown in Fig. 2 (b). In this case, the sum of the load applied to the plate and the contact load between the work rolls is measured as the rolling load, and (3)
Z _{i in the} equation became larger than the original value, and became a disturbance of adaptive control.

[Object of the Invention]

An object of the present invention is to provide an adaptive control method in a rolling mill which can perform a highly accurate set-up of a rolling position.

[Means for solving problems]

The present invention provides a device for measuring the contact length between the work rolls, estimates the work roll contact load according to the contact length between the work rolls measured by the device, considering the estimated load, the rolling load The adaptive control was performed to eliminate the conventional defects.

That is, the present invention, the rolling position and the work roll rotation speed derived by a certain relational expression is rolled as the first set value, the inlet and outlet plate thickness of the rolling mill is measured or estimated, and the rolling load is measured. In order to correct the calculation formula of the rolling load included in the relational expression of the rolling position from the measured value of the rolling load, the signal of the work roll contact length measured by the contact length measuring device between the work rolls provided in the rolling mill is used. It is characterized in that the method of correcting the rolling load calculation formula is changed according to.

〔Example〕

 Examples of the present invention will be described below.

FIG. 1 shows an embodiment of the present invention.

FIG. 1 is an example in which the present invention is applied to a single stand mill, and the rolling mill is composed of a pair of work rolls 1 and back up rolls 3, respectively. A rolling control device 4 for controlling the roll opening, a roll speed setting device 5 for controlling the rolling roll speed, a roll peripheral speed detecting device 6 for detecting the roll peripheral speed, a rolling load detector 7, an inlet side plate thickness measuring device 8, A delivery side plate thickness measuring device 9 and a work roll contact length measuring device 10 are provided.

(1) Setting of rolling position S and roll speed N First, based on the rolling command, the set-up calculation device SET
Then, the rolling load predicted value P ′ _C is calculated by using the following formula, and Z = 1.0.
Calculate as.

However, Z: adaptive correction coefficient K _f ; average deformation resistance b; strip width R '; flat roll radius Δh; target reduction amount; expected contact length between work rolls (values preset in stages and set in a table) (Value selected from among them) x: Roll-to-roll contact load per unit width contact length at both ends of the work roll Next, using the rolling load P _C ′ calculated above, the rolling position S is calculated by the formula (6). The roll rotation speed N to (7)
It is calculated by a formula and sent to the rolling reduction device 4 and the roll speed setting device 5, respectively.

Here, h: Target strip thickness at the outlet side P _C ′; Predicted rolling load value calculated by the equation (5) K: Stiffness of rolling mill S ₀ ; Rolling position during zero adjustment R; Work roll radius V ₀ ; Outlet plate Speed target value f _C ; Advance rate calculated value f _C is expressed by the following formula.

f _C = f (Hi, hi, Ki, Ti, μi) However, Hi: rolling mill plate thickness Ti: tension μi: friction coefficient Specifically, it is calculated using the known Bland & Ford equation.

(2) Adaptive correction calculation of rolling load During rolling and when the rolling speed becomes almost constant, rolling load detector 7, inlet side plate thickness measuring device 8, outlet side plate thickness measuring device 9, work roll contact length measuring device Actually measured rolling load P _A , actual input side plate thickness value H _A , and output side plate thickness actual value h, which were measured in 10 respectively.
_A and the work roll contact length actual value _A are input to the adaptive correction coefficient calculation device CAL, and the adaptive correction coefficient Z _A of the rolling load is calculated by the following formula.

As shown in FIG. 3, the work roll contact length measuring device 10 measures the work roll contact length depending on the presence or absence of light passage between the rolls.

Here, P _A : Actual rolling load _A : Work roll contact length actual value Δh _A : Reduction amount actual value (= H _A −h _A ) b; Coil width x; Contact load per unit width contact length at both ends of work roll The work roll contact load x per unit width used in the formula (8) is obtained by rolling plates having different widths under the same conditions (the same thicknesses of the inlet side plate and the outlet side plate), rolling load and both ends of the work roll. It can be obtained in advance by actually measuring the contact length of.

There are errors in the various actual values used when calculating Z _A in the equation (8), while the deformation resistance K _f of the rolled material also has
It is not a good idea to use this Z _A for the setting calculation of the next material due to reasons such as variations.

The adaptive correction coefficient Z of the rolling load used for the set-up calculation of the next rolled material is obtained from Z _A obtained by the equation (8) using a known exponential smoothing method.

^{Z = Z -1 + δ · (} Z A -Z -1) ... (9) ^{However, Z -1;} preceding value of the adaptive correction coefficient Z of rolling load (. When there is no previous value, and 1.0) Z _A Value δ calculated by the equation (8); exponential smoothing coefficient The adaptive correction coefficient Z of the rolling load obtained by the equation (9) is sent to the set-up calculation device SET.

(3) Sub-pressure material setting calculation In the set-up calculation device SET, if the steel types of the previously rolled material and the currently rolled material are the same, the adaptive correction coefficient Z of the rolling load obtained by equation (9) and the equation (5) Is used to calculate the rolling load predicted value P _C ′. The subsequent steps are as described above.

On the other hand, if the steel types of the next rolled material and this rolled material are different,
In formula (5), the rolling load is predicted and calculated by setting the adaptive correction coefficient Z to 1.0.

〔The invention's effect〕

As described above, according to the present invention, according to the measured work roll contact length, the adaptive correction calculation of the rolling load is performed, so that the rolling load can be accurately predicted and calculated, and accordingly, the highly accurate rolling calculation can be performed. You can set up.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a single stand mill, FIG. 2 is a diagram showing a state of work rolls during rolling, and FIG. 3 is a diagram showing a state of measuring a contact length between rolls. is there. 1 ... Work roll, 2 ... Plate, 3 ... Back up roll, 4 ... Roll-down control device, 5 ... Roll speed setting device, 6 ... Roll peripheral speed detection device, 7 ... Rolling load detector, 8 …… Incoming side thickness gauge, 9 …… Outside thickness gauge, 1
0: Work roll contact length measuring device, SET: Set-up calculation device, CAL: Adaptive correction coefficient calculation device.

Claims (1)

[Claims] 1. Rolling is performed with a rolling position and a work roll rotational speed, which are derived from a constant relational expression, as initial setting values, and the inlet and outlet plate thicknesses of the rolling mill are measured or estimated to measure the rolling load. In an adaptive control method in a rolling mill that corrects the calculation formula of the rolling load included in the relational expression of the rolling position from the measured value of the rolling load, the work measured by a contact length measuring device between work rolls provided in the rolling mill. An adaptive control method for a rolling mill, characterized in that a correction amount of a rolling load calculation formula is changed according to a roll contact length signal.