JPS61182815A - Sheet width control method in hot, reversing, rough milling of steel sheet - Google Patents

Abstract

PURPOSE:To improve the accuracy of sheet width by detecting the rolling reaction of an edger located at the inlet side of a mill as well as detecting the sheet width from the opening of an edger located at the downstream side and controlling further the rolling reduction of the inlet side edger based on a specific equation. CONSTITUTION:Edgers 1, 3 are arranged at the inlet and outlet sides of a reversing mill 2, and rolling load detectors 6, 7 are provided to the edgers 1, 3 respectively. The reference opening of inlet-side edger 1 is previously inputted to an opening command part 8 from an outlet-side aimed sheet-width, after confirming the (i)th pass by an inlet-side sensor 4. The load detector 6 detects a load at the time when the inlet-side edger 1 is turned on to input the detected load to an adder 18 through a feedback part 13 and a multipiler 17. The arithmetic of a feed-forward part 14 is also inputted to the adder 18 through the multiplier 17. The adder 18 adds the operated results of a monitor part 15 to obtain the arithmetic results of an equation I in order to control the edge-opening command part 8. In this way, the accuracy of sheet width is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is for rough rolling a hot-rolled steel plate in a single-lever mill so that the width of the steel plate after rolling is made constant over the entire length as per a target value. The present invention relates to a high-precision automatic board width control method.

[Conventional technology]

A conventional single-lever mill for rolling hot-rolled steel sheets has vertical rolling mills (hereinafter referred to as edgers) 1 and 3 arranged before and after a horizontal rolling mill 2, as shown in FIG. V-H-
It has a V-rolled structure.

Conventional automatic plate width control in such mills is performed using the following two methods.

The first method is the 1975 Spring Lecture on Plasticity Working Proceedings (
This is a method that applies the method shown for pH 7 to pH 120), and uses the edger load detected in the vertical rolling mill 28 further upstream than the single-lever mill shown in FIG. This is a method of controlling the strip width using the die rolling mill 1.

That is, as shown in FIG. 3, the rolling load is detected by the rolling load detector 30 of the vertical rolling mill 28 and input to the load detecting section 31. This input rolling load is calculated by the gauge meter plate width calculation section 3.
2 is converted into a gauge meter plate width, and the vertical rolling mill 1 opening degree control section 33 executes feedforward automatic plate width control.

In the second method, as shown in Japanese Patent Application Laid-open No. 58-148002 by the present applicant, when the tip of the steel plate reaches the rolling downstream edger, A light rolling force of around several tons is applied to the edger on the downstream side of rolling, and the rolling reaction force of the edger on the downstream side of rolling is detected by a rolling load detector. - The width of the steel plate is measured by moving the roll opening degree and understanding the opening degree (constant pressure control), and the width of the steel plate detected as described above at the time when the width control is executed in the next pass. Perform feedforward automatic plate width control using .

In addition, instead of measuring the width of the steel plate using the constant pressure control described above, the opening degree of the edger on the downstream side of rolling is kept constant, the rolling reaction force of the edger on the downstream side of rolling is detected by a rolling load detector, and a gauge meter is used to detect the rolling reaction force of the edger on the downstream side of rolling. The same holds true for constant opening control, which is measured as the plate width.

Furthermore, in addition to feeding forward the plate width of the steel plate measured by the rolling downstream edger described above to the rolling upstream edger of the next pass, (It is also possible to perform feedforward strip width control using the strip width of the steel plate measured by the edger on the downstream side of rolling in the previous pass) as a monitor value.

Conventional automatic sheet width control using a single-lever smill for rolling hot-rolled steel sheets is performed by the two methods described above.

[Problems to be solved by the present invention]

The conventional technology described above has the following three problems.

In the method (1) if, the width control of a steel plate in a single-lever mill can only be performed in the first pass.

(2) In the second method, the width of the steel sheet measured by the edger on the downstream side of rolling in the previous pass does not exist in the first pass, so the sheet width cannot be controlled.

Therefore, in order to control the board width over all passes, the first method and the second method described above may be used together.

However, in a hot-rolled steel mill without the vertical rolling mill 28 shown in FIG. 3, the strip width cannot be controlled in the first pass.

Therefore, the first object of the present invention is to control the strip width from the first pass using only a hot-rolled steel mill without the vertical rolling mill 28 shown in FIG. 3, that is, a single-lever mill shown in FIG. The goal is to provide a way to learn.

In addition, the third problem with the conventional technology is that (3) both the first method and the second method measure the width of the steel plate from the edger load and perform feedforward control. Although low frequency components such as skid marks in the width fluctuation waveform can be removed, other high frequency components cannot be removed.

In Fig. 4, ■ is the strip width variation before strip width control is implemented, and ■ is the strip width variation after the final pass of implementing the above-mentioned second method. Although frequency fluctuations are removed, high frequency fluctuations cannot be removed (the same applies to the first method).

A second objective of the invention is to eliminate this high frequency fluctuation.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention aims to solve the above-mentioned problems.

Strip width control is performed from the first pass only in a single-lever mill to remove high-frequency components of strip width fluctuations.

In addition to the conventional feedforward control and monitor control, the present invention is characterized by load detection type feedback that controls the edger opening by detecting the rolling reaction force of the edger itself that performs strip width control. It is to carry out control.

This load detection type feedback control can be executed from the first pass of the single-lever smilling, and when combined with feedforward control, highly accurate strip width control is possible. That is, feedforward control allows removal of low-frequency board width fluctuations with respect to skid marks, and feedback control allows removal of high-frequency board width fluctuations. The present invention will be explained in detail below.

First, the principle of the load detection type feedback control of the present invention will be explained.

Before the hot-rolled steel plate (bar) enters the single-lever mill shown in Fig. 1a, the initial opening E □ of the edger on the rolling entry side is
(+on) is determined in advance from the target sheet width after single-lever mill rolling. The hot-rolled steel plate enters the rolling entry edger, and the rolling load P is detected by the load detector 6 of the rolling entry edger. (ton) is detected, and from now on, this Po is used as the reference load.

After that, the load detected by the load detector 6 is set to P(t, on
), the width reduction amount ΔECIIIm] by the edger on the rolling entry side is calculated from the following equations (1) and (2).

ΔE= (Gp/M)ΔP+ (G, /l1d)
(1/S)ΔP+ (G o /1ld)SΔP (
mm)” (1) M: Edger-Mill constant (To/
[Second]Hd: Horizontal rolling mill exit side plate thickness [ml11]ΔE:
Edge reduction amount [City] GP: Proportional gain GI: Integral gain Go: Differential gain 1/S: Integral operator S: Differential operator ΔP: Load deviation (Ton) ΔP=P
Pa (Ton: l” (2) P: Load detected by the load detector PO: Reference load In equation (1), the first term is a proportional term of the load deviation obtained from equation (2). This proportional term Since a response delay will occur if only the third term is used, a third differential term is provided to ensure a high response.The second term is an integral term to absorb the control offset.

Now, the basic arithmetic expression of the present invention, which combines the above-mentioned feedforward control, monitor control, and above-mentioned load detection type feedback control, is shown by equation (3).

ΔE=α((Gp/M) + (G r /Hd) (
1/S) + (G o /Hd)S)ΔP+(1-a
)CWi-1/aim)/(IQ)+ΔvII+・
...(3) α: Control weight coefficient (0≦α≦1).

M: Edger Mill constant [Ton/mm] rlid:
Horizontal rolling machine outlet plate thickness.

GP biproportional gain.

Gz: Integral gain.

' Go: Differential gain.

Sui: Strip width (11 m) measured by the edger on the downstream side of the previous pass rolling using the second method of the prior art.

Waim: Target board width (mm).

η Bow width return amount (0 < η × 1).

ΔWm: Monitor correction amount described in the second method of the prior art.

S: Differential operator.

The first term is the load detection type feedback term unique to the present invention, the second term is the feedforward control term described in the second method of the conventional technique, and the third term is the monitor described in the second method of the conventional technique. This is the amount of correction due to control.

Here, Wi is the strip width measured at the edger on the downstream side of rolling in the previous pass described in the second method. As mentioned above, in feedforward control that uses the strip width measured at the edger on the downstream side of rolling, the width fluctuations of high frequency components are removed by rotation, and only the low frequency components due to skid marks of 2 to 3 Hz can be removed. do not have.

Therefore, feedforward control mainly absorbs low frequency width fluctuations such as skid marks.

Width fluctuations at higher frequencies than this are absorbed by utilizing the load detection type feedback ring of the first term, especially the differential term.

Furthermore, in the first pass, by setting α=1 in equation (3), plate width control is possible using only the load detection type feedback ring.

[Effect]

FIG. 1a schematically shows an apparatus configuration for carrying out one embodiment of the present invention. Since this is a single-lever mill, the steel plate flows in two ways in the figure: from left to right and from right to left, but for simplicity, the i-th pass from left to right (i = 1.2, 3, etc.) is used.・
... n arbitrary, n is the final bus).

When the input side sensor 4 is turned on, it is recognized that the rolling direction is from left to right in the figure, and that it is the i-th pass based on the number of times the sensor is turned on. Also, when the inlet sensor 4 is on, the inlet edger reference opening degree E is determined from the i-pass outlet target plate width. [mm] is input to the edger opening command section 8 in advance. From now on, the edger opening command section 8 will control this E.
, is the standard opening, and by adding ΔE obtained by equation (3), the Ezier opening command is Eo + ΔE.
Output to.

When the rolling entry side edger 1 is turned on, the rolling load is detected by the rolling load detector 6 and inputted to the load detection type feedback section 13.

The calculation result of the load detection type feedback section 13 [namely, (
1) is multiplied by α by the multiplier 16 and input to the adder 18. Further, the result calculated by the feedforward section 14 is multiplied by (1-α) by the multiplier 17 and input to the adder 18 . The adder 18 adds the above-mentioned two calculation results and the result calculated by the monitor part 15, and outputs the result as ΔE to the edger opening command section 8, and the edger opening command section 8 controls the edger opening. move the degree.

Further, at the time when rolling of the steel plate is started by the rolling downstream edger 3, the width measurement by the rolling downstream edger described in the second method of the prior art is performed. The detailed contents are described in Japanese Unexamined Patent Publication No. 148002/1982, so they will be omitted, but only the outline will be briefly described.

While the rolling load detector 7 detects the rolling load, the constant load control section 11 sends a command to the edger opening command section 9, and the strip width measuring section 12 reads the signal from the edger opening detector 10 and determines the strip width. is measured, stored in the sheet width information storage section 19, and also inputted to the monitor section 15. Further, the feedforward unit 14 extracts the board width data of the previous pass from the board width information storage unit 19 and uses it.

Even during reverse rolling, control can be performed in the same manner as described above by simply switching the edger 1 and edger 3 as shown in FIG. 1a.

A specific circuit of the load detection type feedback section 13 which characterizes the present invention in FIG. 1a is shown in FIG. 1b.

When the steel plate enters the rolling input edger 1, that is, the input sensor 4 is on and the rolling load detector 6 detects the rolling load P o
When (t, on) is detected, PO is stored in the memory 27.

After that, the load P measured by the rolling load detector 6 from time to time
The subtracter 20 calculates the difference between PO and the content PO of the memory 27, and inputs the result to each of the multipliers 21-23. The multiplier 21 multiplies the signal by G p /M and inputs it to the adder 26 . The multiplier 22 multiplies the signal by Gz/Hd, passes through the integrator 24, and then inputs the signal to the adder 26. The multiplier 23 multiplies the signal by Go/Hd, passes through the differentiator 25, and then inputs the signal to the adder 26. Adder 26 outputs to multiplier 16.

〔Example〕

The results of implementing the present invention and the results of implementing the conventional method are shown in FIG. 1c.

In Figure 1c, the left side is the steel plate top part, the right side is the steel plate bottom part, bar thickness 28cm, par width 1243Ill.
FIG. 2 is a diagram illustrating changes in the width of a steel plate after single-lever rolling for a steel plate having a p-bar length of 1243n+m. The solid line is the result obtained by the present invention, and the broken line is the result obtained by the conventional method.

As can be seen from FIG. 1c, the accuracy of the present invention is much higher. In particular, high frequency components are removed very well.

〔Effect of the invention〕

As explained above, according to the present invention, by combining conventional control with load inspection type feedback control in a single lever smill, strip width control can be executed from the first pass, and highly accurate strip control can be achieved. This can contribute to reducing the amount of width margin, that is, improving yield.

[Brief explanation of the drawing]

FIG. 1a is a block diagram showing the configuration of a device that implements the strip width control of the present invention in one embodiment, FIG. 1b is a block diagram showing the configuration of the load detection type feed forward section shown in FIG. 1a, and FIG. 1c 2 is a graph showing the implementation results of the present invention and the implementation results of the conventional example, FIG. 2 is an explanatory diagram of the configuration of a single lever rough rolling mill, and FIG. 3 is an explanatory diagram of rough control in conventional lever rough rolling. It is. 1.3: Edger 2 double flat rolling mill 4: Inlet sensor 5: Outlet sensor 6: Load detector 7: Rolling load detector 8: Edger opening command section 9: Edger opening command section 10 : Edger opening detector 11D Constant load control section 1
2: Plate width measuring section 13: Load detection type feedback section 14 Nib feed forward section 15: Monitor part 16:
Multiplier 17: Multiplier 18: Adder
19: Board width information storage section 20: Subtractor 21, 2
2, 23: Multiplier 24: Integrator 25: Differentiator 26: Adder 27: Memory 28:
Vertical rolling mill 29: Horizontal rolling mill 30: Rolling load detector 31: Load detection section 32: Gauge meter plate width calculation section 33: Vertical rolling machine speed control section Foil 1a■ 1b Second country procedure correction band ( ) 1. Display of case 1985 patent application No. 023311 2
, Title of the invention Plate width control method 3 in hot reverse rough rolling of steel plates, Relationship with the amended case Patent applicant address 2-6-3 Otemachi, Chiyoda-ku, Tokyo Name (665) Nippon Steel Corporation Co., Ltd. Representative Takeshi 1
) Yutaka 4, Agent 103 Telephone 03-864-6
052 Address 2-27-6-5 Higashi Nihonbashi, Chuo-ku, Tokyo, Subject of amendment Detailed explanation of the invention in the specification. Brief description of drawings and drawing 6, contents of amendments (1) “Bar length 1243 mmJ” in page 14, line 6 of the specification.
"The bar length is corrected to 41.7 mJ." (2) "This is an explanatory diagram of." on page 15, line 8 of the specification is corrected as follows. Figure 4 is a graph showing strip width fluctuations according to the conventional method. (3) Correct figures 1a and 1b[l as shown in the attached appendix, and add figure 4. 7. Inventory drawing of attached documents... Mitsuba Sou 1a Wing 1bl

Claims (1)

[Scope of Claims] In a single lever rough rolling facility having edgers on both the entry side and exit side of the reverse rough rolling mill, the rolling reaction force of the edger that controls the strip width on the entry side of the reverse rolling mill is detected, and A plate in hot reverse rough rolling of a steel plate, characterized in that the plate width of the material to be rolled is detected from the opening degree of the edger on the downstream side of rolling, and the plate width of the edger on the entry side of the reverse rolling mill is controlled by the following formula: Width control method: ΔE=α [(Gp/M)+(G_I/Hd)(1/S)
+(G_D/Hd)S]ΔP+(1-α)(Wi-Wa
im)/(1-η)+ΔWm In the formula, ΔE: Reduction amount of the entrance edger (mm), α: Control weight coefficient (0≦α≦1)
, M: Edger mill constant (tons/mm), Hd: Horizontal rolling mill outlet side plate thickness (mm), Gp: Proportional gain, G_I: Integral gain, G_D: Differential gain, Wi: Opening degree of edger on the downstream side of rolling, Vaim: Target board width, η: Width return rate (0<η<1), and ΔWm: Monitor correction amount.