JPS63119920A - Method and device for controlling plate rolling shape - Google Patents

Abstract

PURPOSE:To control the deflection amt. of a work roll properly and to obtain a good plate shape by finding the roll deflection amt. from the roll gap detection amt. of an edge part and the roll gap amt. of the center part calculated from rolling conditions. CONSTITUTION:A plate stock 12 is rolled by giving deflection in the plate width direction to work rolls 14A, 14B by work roll bending device 18, 18B and the roll gap amt. of the edge part of the rolls 14A, 14B is detected by detectors 22A, 22B. On the other hand the roll gap amt. at the center part of the rolls 14A, 14B is calculated from the rolling conditions by the roll center gap amt. computing element 24 of a plate rolling shape control device 11. The roll deflection amt. is calculated from the detection value and calculation value by a computing element 28, compared with a preset target deflection amt. by an adder 30 and based on this result the bending devices 18, 18B are controlled by a work roll bender controller 32. The necessary deflection in the plate width direction is thus given to the rolls 14A, 14B.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a sheet rolling shape control method and apparatus, and in particular,
This invention relates to improvements in a rolling plate shape control method and device suitable for use in appropriately controlling the exit side shape of a plate when a plate shape (flatness) detection means is not provided on the rolling mill exit side. .

[Conventional technology]

One of the important quality control items for plate material, which is a rolled product, is the cross-sectional shape (plate shape) of the plate. Therefore, in plate rolling, in order to obtain a good plate shape, roll deflection in the width direction of the plate must be set to an appropriate value. It is necessary to maintain Regarding such roll deflection, in conventional rolling mill plate shape control, if a plate shape (flatness) detector is provided on the exit side of the rolling machine, the output of the detector is used to control the roll width in the strip width direction. A good plate shape can be obtained by correcting the deflection to an appropriate value. On the other hand, if there is no plate shape detector on the exit side of the rolling mill, the relationship between rolling load changes, which are the main disturbances to the plate shape, and roll deflection changes (or changes in appropriate plate shape parameters) is usually first determined. and a relational expression showing the relationship between the plate shape operation amount for the rolling mill and the roll deflection change, and then predict the plate shape operation amount to eliminate the roll deflection change caused by the rolling load fluctuation. This is inputted into the plate shape control end of the rolling control device of the rolling mill to prevent plate shape defects from occurring. For example, Japanese Patent Application Laid-Open No. 59-64111 discloses an inter-stand shape MD9 method in a tandem mill in which the control amount of the shape i control means is changed in a cylindrical manner in response to changes in rolling conditions regarding the rolled plate shape i control as described above. It is shown. In this shape control method, first, the plate width B and the rolling 7y
Roll deflection change ΔCP in sheet width direction relative to weight change ΔP
A relational expression showing the relationship is obtained as shown in the following equation (1). ΔCp=r 1 (B, ΔB) ... (1) And roll deflection change ΔC in the board width direction with respect to board width B and deflection force (pending force) change ΔB to the work roll
A relational expression representing the relationship between e is obtained as shown in the following equation (2). ΔC5=fz(B, ΔB) ... (2) (1), (
2) The deflection force whose absolute values of the deflection changes ΔcP and ΔCe obtained from the formula are equal and opposite in sign (-Δ(p=ΔCs)) is predictively output to the bending mechanism 81 of the work roll, and the plate crown is The shape of the plate is controlled by changing it.

[5! , the problem that Ming tries to solve] However,
In the conventional plate shape control method as described above, firstly, when the above-mentioned relational expression is experimentally determined, there is a large variation in the experimental data, and when the above-mentioned relational expression is determined using simulation, there is a large variation in the experimental data. The response is unclear,
Furthermore, highly accurate sheet shape controllability could not be expected because there are many factors to consider, such as sheet width, rolling load, work roll curve, and sheet thickness. That is, in the plate shape control method, the final plate shape control amount does not depend on the amount of roll deflection in the width direction of the plate, which has a direct relationship with the plate shape, but rather controls the plate shape using indirect quantities such as roll deflection force. Therefore, the above reasons have been an obstacle to improving the reliability of control. Furthermore, as a technology related to r'A of the present invention, Japanese Patent Application Laid-Open No. 57-1
There is a roll gap measuring device for rolling mill work rolls proposed in Japanese Patent No. 37012 for accurately measuring the roll gap. In this measuring device, a contact type distance detector is used as a roll gap detector, and this detector is mounted with a ring band at a position sufficiently close to the roll barrel portion, which is the original measurement point, and the detector is mounted By holding the part so that it does not change with respect to the upper and lower rolls, the roll gap is measured while minimizing the effects of roll bending and rattling on measurement accuracy. However, the above measuring device only detects the roll gap with a contact distance detector attached to the work roll 0, and is not a technology for detecting the amount of roll deflection, but a technology for appropriately controlling the strip plate shape. It wasn't.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned conventional problems, and it is possible to give a work roll a desired deflection in the sheet width direction even when rolling conditions change, and therefore, a good sheet shape can be achieved. It is an object of the present invention to provide a method and apparatus for controlling a rolled plate shape that can obtain the following properties.

[Means to solve the problem]

The present invention detects the roll gap amount at the edge portion of the work roll when rolling a plate using a rolling mill in which the work roll is bent in the width direction of the work roll by a bending means,
From the rolling conditions of the rolling mill, calculate the amount of roll gap in the inner part in the sheet width direction from the edge portion, calculate the amount of deflection of the work roll in the sheet width direction from the detected roll gap amount and the calculated roll gap amount, The above object is achieved by performing the bending ats to give the work roll a desired deflection in the sheet width direction based on the calculated deflection amount. The present invention also provides a plate rolling shape control device for controlling the shape of a plate when rolling a plate using a rolling mill in which a work roll is bent in the width direction of the work roll by a bending means. means for detecting the roll gap amount of the work roll from the rolling conditions of the rolling mill; means for calculating the roll gap amount at the center of the work roll from the rolling conditions of the rolling mill; means for calculating the deflection amount in the sheet width direction; means for comparing the calculated deflection amount with a preset target deflection amount; The above object is also achieved by comprising means for controlling the bending means.

[Effect]

In the present invention, when controlling the rolling shape of the plate M, the roll gap amount at the edge portion of the work roll of the rolling mill is detected, and the inner part of the work roll in the plate width direction is detected from the rolling conditions of the rolling mill. Calculate the roll gap amount of
From the detected roll gap amount and calculated roll gap amount,
The deflection in the width direction of the work roll is calculated, and based on the calculated amount of deflection, the bending tap of the rolling mill is adjusted to give the work roll a desired deflection in the width direction.
tat control. Therefore, since the roll deflection of the work roll is calculated from the detected roll gap amount at the edge portion and the calculated roll gap amount at the inner portion in the strip width direction, it is not necessary to install a strip shape detector on the exit side of the rolling machine. In both cases, the roll deflection in the sheet width direction can be obtained with high precision, and if the work roll is deflected based on the obtained roll deflection, the desired sheet width direction deflection can be obtained in the work roll, resulting in a good sheet shape. It is possible to realize this. Furthermore, since it is not necessary to provide a plate shape detector on the exit side of the rolling mill, the device configuration is simplified, the reliability of the device is increased, and a highly responsive ADMI system can be realized. Further, although the plate shape detector is generally expensive, the measuring device for detecting the roll gap amount at the edge portion is generally inexpensive, so that the price of the entire device can be reduced.

[Embodiment 8ilI] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view, including a partial block diagram, showing the configuration of a rolling mill 10 and a plate rolling shape control device 11 according to this embodiment. In order to control the plate shape, this rolling IIO mainly includes the plate rolling shape control device 11, work roll bending devices W118A and 18B described later, and upper and lower work rolls 14A and 14B for rolling with inserting, and the workpiece. upper and lower backup rolls 16A, 16B for sandwiching and pressurizing the rolls 14A, 14B from above and below; a work roll bending device M18A for applying a bending force (pending force) to the roll chock 15A to bend the work rolls 14A, 14B; 18B, load cells 20A, 20B for detecting rolling load P, and roll chocks 17A, 1 of the backup roll 16A.
Roll gap detectors 22A and 22B are provided at the work rolls 7B for detecting the roll gap ρE' between the edge portions of the work rolls 14A and 14B. Note that, for example, Magnescale can be used for the roll gap detectors 22A and 22B. Also, 23 in the figure
is the frame of the rolling mill 10, 25 is the backup roll 1
This is a spring for applying pressure to 6A and 16B. The plate rolling shape control device 11 includes the load cell 20.
A, from the rolling load ff1P from 2013, the detected values ρE' of the roll gap detectors 22A and 22B, and the actual value of the work roll deflection force (pending force) Fw of the work roll bending devices 18A and 18B, the work roll A roll center gap amount calculation unit 24 is provided for calculating the roll gap at the center of the rollers 14A and 14B. This roll center gap amount calculator 24 includes a rolling condition setting device 26 for setting rolling conditions such as sheet width and roll crown in order to read the rolling conditions! a
Being pillowed. The output of the roll center gap amount calculator 24 is input to a roll deflection 2 calculator 28 for calculating the deflection amount of the work rolls 14A, 14B. The roll deflection 2 computing unit 28 is connected to the roll gap detector 22A.
, 22B are input, and the roll deflection amount Δρ is calculated from the input roll gap amounts at the center gap base and the edge portion. The calculated roll deflection amount Δρ is the target roll deflection amount Δρ and an additional point of 30
are compared and their difference is taken and input to the work roll bender controller 32. The work roll vendor f1i
The till device 32 controls the pending force of the work roll bending devices ff18A, 18B to change the amount of deflection of the work rolls 14A, 14B. The effects of the embodiment will be explained below. When rolling the plate material 12 in the rolling mill 10 according to this embodiment, the edge roll gap detectors 22A and 22B detect the distance between the backup roll chocks 17A and 17B and the work roll chocks 15A and 15B, and the roll gap at the edge part is detected. Detect ρE′. By the way, when a rolling load f (P is applied to the central part of the work rolls 14A and 14B in the width direction, as shown in rolling 1ffilo in FIG. 2, the backup roll 1
The following formula (
3), roll flatness Δ1 and Δ2 shown in (4) occur, and roll deflection δ occurs. Δ1 ” P 1 (Cr B r Cr W *
P + FW +B, r,...) ・-(
3”)Δ2=Pz(P,B)・−(4)δ”
f (Cr B * Cr W * P + F
W e B + ",...) ...(
5) However, crs is backup roll crown, cr
w is the work roll crown, Fw is the work roll pending force, B is the plate width, and `` is the roll material. Therefore, the center portion in the width direction of the plate applied toward the top of the mill with the kiss roll state of the work rolls 14A and 14B as the reference state. The roll gap change ρC is calculated by the following equation (6): ρC=Δ1+Δ2+δ (6) On the other hand, from the detected values ρε′ detected by the edge roll gap detectors 22A and 22B, The roll gap amount ρE at the edge portion is calculated by subtracting the roll gap detection value ρε0 in a certain kiss roll state as shown in the following equation (7). Then, from the roll gap change ρC and the calculated roll gap amount ρE, the following equation (8) is the roll deflection in the sheet width direction Δ
ρ is required. ρE=ρE'-ρEO・-(7) Δρ=ρE-ρC...(8) The obtained sheet width direction roll deflection Δρ is the target deflection amount Δ
Work roll bender controller 3 to match ρX
2, the work roll bending devices 18A and 18B are
By manipulating the pending force on the work rolls 14A and 14B, it is possible to keep the roll deflection of the work rolls 14A and 14B constant in the board width direction. Note that the appropriate target roll deflection amount ΔρX can be given experimentally or analytically. Here, further explanation will be given regarding the procedure for IC controlling the roll deflection Δρ in the sheet width direction. First, before starting rolling, the rolls are placed in a kissing state, and the roll gap detectors 22A and 22B in the joint part detect the reference value ρEo of the roll gap, and the reference value ρ2G is recorded in the roll deflection total wave counter 28. The reference value ρε0 can not only be detected as described above, but also determined from the mechanical dimensions of the rolling mill 10, such as the diameters of the backup rolls 16A and 16B and the work rolls 14A and 14B. When rolling is started, the specifications of the rolling mill 10, strip width B, each roll crown Cr date, CrW are input from the rolling condition setting device 26.
Roll center gap amount calculation unit 24 calculates the rolling conditions such as
Then, the roll center gap amount calculation unit 2
4 is the read rolling conditions, the input rolling imp;
And from the actual value of the pending force Fw of the work roll,
The roll gap change ρC at the center in the sheet width direction is determined. The determined roll gap change ρC is input to the roll deflection full wave counter 28. The roll deflection full wave calculator 28 calculates the plate using the equations (7) and (8) from the roll gap change ρG and the roll gap detection value ρε' detected and input by the roll gap detectors 22A and 22B. Width direction roll deflection Δρ
Calculate. The calculated roll deflection foot Δρ is an additional point of 3
Compare with the target roll deflection amount of 69 troops at 0. As a result of the comparison, if the calculated roll deflection amount Δρ is larger than the target roll deflection amount Δρ East, the work rolls 14A and 14B have a narrower roll gap at the center in the sheet width direction than the target roll deflection amount 69, and therefore the plate material 12 is a belly stretch. Therefore, in this case, the work roll bender controller 32 creates a command to reduce the pending force, and outputs the command to the work roll benders 18A, 18B to narrow the roll gap at the edge. This prevents the belly from stretching. On the other hand, if the calculated roll deflection amount Δρ becomes smaller than the target roll deflection amount Δρ East, the actual roll gap becomes narrower than the target roll gap at the edge portion of the plate material 12, so that the plate material 12 is in an edge-stretched state. Become. Therefore, in this case, the work roll bender controller 32 creates a command to increase the pending force of the work rolls 14A, 14B and outputs it to the work roll benders 18A, 18B to widen the roll gap at the edge. This prevents the above-mentioned edge elongation. Next, the results of plate rolling shape control according to the present invention are as follows.
Based on the drawings, a comparison will be made with sheet rolling shape control according to the prior art. Fig. 3 shows the results of control using the conventional technology, and Fig. 4 shows the results of control using the present invention. Figs. Deflection amount δ (both figures (A)) and plate shape A
2 (both figures (B)), the plate shape Δ2 is plate material 1.
2. Difference in elongation rate between the center part and the plate edge part. The plate shape Δ2=0 indicates that the plate shape is flat, the plate shape 2>0 indicates that the plate has an edge elongation, and the plate shape A2×0 indicates that it has a belly elongation. In conventional control, as shown in Fig. 3 (A), when the target roll deflection amount 69 changes, the actual roll deflection amount δ matches the target roll deflection amount 69 due to a problem with the beginning of the relational expression. As a result, the predicted plate shape change ff1A2'' does not match the actual plate shape change RAz', as shown in FIG. As shown in Fig. 4 (A), the actual roll deflection amount δ can be made to match the target deflection amount 69, and as shown in Fig. 4 (B), the predicted plate shape change ff1A2x and the actual plate The shape changes of the whole body 2' are consistent in the steady state except for the rising part. From the above, controlling the rolled plate shape using the present invention is more effective in maintaining the plate shape in a good condition than the conventional technology. In the above embodiment, two changes in the roll gap at the center in the sheet width direction were determined based on the detected edge roll gap ρε, but when applying the present invention, The roll gap is not limited to the central part in the width direction of the board, but the amount of roll gap at an appropriate position inside the edge part in the width direction of the board is determined, and the work roll bending device is controlled more precisely to form the board in the desired shape. In addition, in the embodiment, the edge roll gap detectors 22A, 22B are connected to the backup rolls 16A, 16.
Magnescale was exemplified as the type of backup roll chocks 17A and 17B of B, but the position and type of the roll gap detector is not limited to those mentioned above, and the roll gap detector is installed on the roll at the edge of the work roll. Other positions and other types of roll gap detectors can be used as long as gaps can be detected. Furthermore, in the embodiment described above, a case was disclosed in which a four-stage rolling mill 11110 as shown in FIG. Machine and plate rolling shape rr! 11
The 1I apparatus is not limited to the structure described above, and other rolling mills and sheet rolling shape intervening apparatuses may also be used.

【Effect of the invention】

As explained above, according to the present invention, the deflection amount of the work roll in the width direction is calculated by detecting the roll gap 7ffi at the edge portion of the work roll. There is no need to provide a work roll, and the roll deflection in the plate direction can be obtained with high accuracy.If the work roll is deflected based on the obtained roll rope h, a plate material with a good plate shape can be obtained. Further, since there is no need to provide the plate shape detector, the device configuration becomes simple, the reliability of the device increases, and it is possible to realize a control system with high responsiveness. Further, excellent effects such as being able to construct a control device at low cost without using a generally expensive plate shape detector and reducing the cost of the entire device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram including a partial view showing the actual IMPJ of the plate rolling and shaping apparatus according to the present invention, and FIG. Figures 3 (A) and 3 (B) are diagrams showing examples of roll deflection and plate shape changes, showing control results according to the prior art when the target roll deflection amount is changed; FIGS. 4A and 4B are diagrams showing examples of roll deflection and plate shape change when controlled by the method of the present invention. DESCRIPTION OF SYMBOLS 10... Rolling mill, 11... Plate rolling shape 11 control device, 12... Plate material, 14A, 14B... Work roll, 16A, 16B... Backup roll, 18A, 1
8B... Work roll bending device. 20A, 20B... Load cell, 22A, 22B... Edge roll gap detector. 24...Roll center gap amount calculator, 26...
Rolling condition setter, 28... Roll deflection full wave calculator, 30... Addition point, 32... Work roll bender controller.

Claims (2)

[Claims] (1) When rolling a plate using a rolling mill in which the work roll is bent in the width direction of the plate by a bending means, detect the roll gap amount at the edge portion of the work roll, and calculate the amount of roll gap at the edge portion of the work roll from the rolling conditions of the rolling mill. Calculate the amount of roll gap at the inner part in the width direction of the work roll, calculate the amount of deflection of the work roll in the width direction of the work roll from the detected roll gap amount and the calculated roll gap amount, and place the desired board on the work roll based on the calculated amount of deflection. A method for controlling rolled sheet shape, characterized in that the bending means is controlled to give a deflection in the width direction. (2) In a plate rolling shape control device for controlling the shape of a plate when rolling a plate using a rolling mill in which a work roll is bent in the width direction of the plate by a bending means, a roll gap at an edge portion of the work roll is provided. means for calculating the amount of roll gap at the center of the work roll from the rolling conditions of the rolling mill; and means for calculating the amount of deflection in the width direction of the work roll from the detected roll gap amount and the calculated roll gap amount. means for comparing the calculated deflection amount with a preset target deflection amount, and controlling the bending means to give the work roll a desired deflection in the sheet width direction based on the comparison result. A plate rolling shape control device comprising: means;