JPS606214A - Method and device for preventing snaking in plate rolling - Google Patents

Abstract

PURPOSE:To detect exactly generation of snaking in an initial state and to prevent surely and easily the snaking by preventing the uneven elongation of a rolled material having a correlation with the shifting rate of a plate owing to snaking. CONSTITUTION:The asymmetrical component DELTAlambda(=lambdaW-lambdaD; lambdaW, lambda are the difference in elongation rate between operating and driving sides) relative to the center of the width of a plate of a difference in the elongation rate of a rolled a material 1 is detected with a shape detector 3 and is outputted to a discriminator 6. Control is required when DELTAlambdanot equal to 0 and the plate shifts to the driving side if DELTAlambda>0 and to the operating side if DELTAlambda<0. These values are thereupon outputted to a calculator 7A and the calculation for control is executed in an arithmetic means 20. The gap of work rolls 12 in the transverse direction of the plate is thus adjusted by a control means 8 (screw-down and roll bending devices).

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a method and device for preventing meandering in plate rolling.
In particular, the present invention relates to a method and apparatus for preventing meandering in the rolling of a shingle plate, which can quickly and reliably prevent meandering by considering the one-sided elongated shape of a rolled material as a condition for preventing meandering.

[Background of the invention]

In recent years, efforts have been made to improve the widthwise distribution of plate thickness and the crown of the plate in order to improve operability, product quality, and yield during plate rolling, and a considerable degree of flattening of the plate crown has been achieved. It is now possible to do so.

However, with the improvement of the plate crown, the meandering of the rolled material,
In other words, preventing the misalignment between the center of the mill and the center of the sheet width has become a major operational problem. In other words, the more uniform the plate thickness becomes due to flattening of the plate crown, the more factors such as the uneven gap of the work roll in the width direction of the plate and the asymmetry of the thickness distribution on the entrance side of the rolled material (wedge material) will have a greater influence. This makes it easy to meander. As a result, the rolling work is hindered due to collisions of the rolled material with the side guides, poor squeezing into the rolls, squeezing, etc. In addition, due to this meandering, the rolling mill is damaged and often This has become a major problem as rolling operations have to be interrupted.

Conventionally, various efforts have been made to solve this problem, but the meandering prevention function is impaired by disturbances, and sufficient effects have not been achieved.

[Purpose of the invention]

An object of the present invention is to provide a method and apparatus for preventing meandering in plate rolling, which can accurately detect the occurrence of meandering in an initial state and can reliably and easily prevent meandering.

[Summary of the invention]

The present invention was made based on the newly discovered result that the amount of sheet deviation due to meandering has a phase relationship corresponding to the asymmetric component of the elongation rate difference of the rolled material with respect to the sheet width center, that is, the one-sided elongation shape. be.

That is, as shown in FIGS. 1 and 2, the amount of sheet deviation due to meandering is expressed by the distance Δd between the mill center A and the sheet width center B of the rolled material 1 between the work rolls 12.

As shown in FIG. 1, the plate deviation amount Δd is at a position b/2 from the center of the plate width of the rolled material 1 and both ends in the width direction of the pick plate.

The inventors have studied the occurrence of the amount of plate deviation Δd from various angles, and as shown in FIG. 3, the amount of plate deviation Δd
d and the asymmetric component Δλ of the left and right elongation rate difference with respect to the center of the plate width
It was discovered that y and y occur with the same tendency. That is, the solid line curve Δd in FIG. 3 shows the change over time in the amount of sheet deviation, and the broken line curve Δλ shows the change over time in the elongation rate difference in the width direction of the rolled material. From this figure, it can be seen that the amount of sheet deviation Δd and the asymmetric component Δλ of the elongation rate difference change with a constant correlation.

In the method and device for preventing meandering in plate rolling according to the present invention, when sheet displacement of a rolled material occurs due to meandering, an asymmetrical component of the elongation rate difference of the rolled material with respect to the center of the sheet width occurs. A detector detects this and adjusts the gap between the rolls so as to eliminate the asymmetric component of the tooth strip elongation shape before sheet deviation actually occurs.

Specifically, the gap adjustment is performed by operating a rolling device or a roll bending device. - [Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to FIG.

First, the meandering prevention device will be explained.

A plurality of optical sensors 2 for viewing the surface shape of the rolled material 1 are arranged in the width direction near the exit side of the work roll 12.

Each sensor 2 is connected to a shape detector 3, and the rolled material 10
The asymmetrical component of the elongation rate difference of the rolled material 1 with respect to the center of the plate width is detected based on the one-sided elongation shape, that is, the difference in the degree of unevenness between the left and right sides of the surface of the rolled material 1. Shape detector 3 is connected to calculation means 20. The calculation means 2o is a discriminator 6
, seven computing units and an integrator 7B. The discriminator 6 is configured to discriminate the phase state in which plate displacement occurs based on the asymmetric component Δλ of the elongation rate difference detected by the shape detector 3. The computing unit 7A calculates the amount of adjustment of the gap between the poles, for example, the amount of adjustment of the roll reduction position, which is necessary to remove the asymmetric component of the elongation rate difference, based on the discriminant value a of the phase state determined by the discriminator 6. It has become. Further, the integrator 713 inputs and integrates the roll-down position adjustment amount ΔS calculated by the calculator 7A, and calculates the roll-down position adjustment amount ΔSw on the operating side and drive side of the rolling mill.

ΔSD is respectively integrated. Furthermore, discriminator 6
A plate deviation amount detector 5 is connected to the plate deviation amount detector 5 which detects the actual plate deviation amount and plate deviation direction based on the position signal of the rolled material 1 from the optical sensor 4. Based on this plate deviation amount Δd, a shape detector 3, the correspondence relationship between the one-sided elongation and the direction of sheet slippage is checked.

Further, a pair of roll lowering devices 8 are connected to the integrator 7B as control means for adjusting the gap between the rolls.

Each of the rolling devices 8 has a rolling position control device 9 incorporated therein, and is adapted to correct the rolling amount based on the inter-roll gap adjustment signals ΔSw and ΔSD on the operating side and the driving side from the integrator 7B. It has become. 10 and 11 indicate the hydraulic power source and hydraulic cylinder of the lowering device 8, respectively.
13 indicates a pressure roll.

Next, the method will be explained. In the meandering prevention method according to this embodiment, the elongation rate difference (shape) detected by the shape detector 3
The left and right rolling down devices 8 are operated to remove the asymmetrical component Δλ, and the gap in the width direction of the work roll 12 is adjusted to prevent the rolled material 1 from meandering.

To be more specific, the shape detector 3 detects the asymmetric component Δλ (=, λW−λD) of the elongation rate difference of the rolled material 1 with respect to the plate width and δ.
is detected and output to the discriminator 6. Here, λW and λD are the elongation rate differences between the operating side and the driving side as described above. Δ
If λ=0, there is no need for control. If ΔλNO, control is required. In this case, if Δλ〉0, λW is large, so the plate slides toward the drive side where the elongation rate difference is small, and conversely, if Δλ〈0, λD is large, so the plate slides toward the operating side. becomes. Therefore, control calculations are performed by outputting these values to seven calculation units.

In this embodiment, the actual direction of the plate deviation is checked using the plate deviation amount detector 5. That is, the deviation amount Δd of the center of the plate width from the center of the mill (the case where the rolled material deviates toward the operation side of the rolling mill is positive) is detected, and this detected value is also output to the discriminator 6. The discriminator 6 receives the signals Δλ and Δd and first performs the following discrimination necessary to check the correspondence between Δλ and Δd.

a=Δλ・Δd・Old... (1) a) If O, there is no need to perform control. That is, Δλ
〉0. This is because if Δd)Q or Δλ<o, Δd<0, no sheet deviation actually occurs.

On the other hand, if a<o, the measured value based on the elongation rate difference and the actual plate shear direction match, and sheet shear occurs, so the asymmetric component Δλ of the elongation rate difference is further canceled by seven calculators. The work roll gap difference ΔSλ (=Sw-8
o, where Sv and So are the gaps on the operation side and drive side of the work roll 12, respectively) and output the results to the integrator 7B. The calculation formula is based on the following formula.

αL ΔS, = Δh□ River... (2) K, b, h Here, Δh is the difference in plate thickness in the width direction, and α is the correction coefficient for error (9). For example, the influence of the material of the rolled material, etc. What to correct, L is the distance between the operation side and drive side rolled down position, K is the spring coefficient of the roll (parallel stiffness coefficient), and bl is the distance between the position λW and 20 that defines the asymmetric component Δλ of the elongation rate difference. be.

Δh and in equation (2) are expressed by the following equation.

Δh (=hw ha)= [:h-K-btaA(1
-ξ)]Δλ ・(3) Here, h is the plate thickness at the center of the plate width, K a h is the plate crown correction coefficient, t4 is the contact projection length, and ξ is the strain difference ratio (33rd plasticity M is the plasticity coefficient of the rolled material, b is the plate width, KM is the spring constant of the housing, Kmw is the spring constant between the rolls, LR is the roll body It is long.

The integrator 7B receives the signal ΔSJ from the arithmetic unit 7A, and
In order to perform more stable control, perform the following product (10).

ΔBS=Δ8J +/ΔS, dt (5
) Furthermore, using ΔS'□, the amount of adjustment of the reduction position on the operation side and the drive side is calculated and outputted to each reduction position control device 9.

The rolling down position control device 9 always performs good meandering prevention by correcting the operating side and drive side rolling down devices by ΔSv and ΔSD, respectively.

Note that the arithmetic unit 7A and the integrator 7B in the embodiment of the present invention may be replaced with a single arithmetic unit to perform a series of calculations over the formulas (1) 2 to (ζ).

According to the method and device for preventing meandering control in plate rolling according to the present embodiment, the initial state of meandering, which is the detection of a one-sided elongated shape, is detected and the meandering prevention action by adjusting the rolling reduction is immediately performed before meandering begins. , it is possible to achieve a reliable and quick meandering prevention effect.

(11) In particular, when it is based on shape detection, it is less affected by external disturbances, and meandering can be prevented with minute steps. In addition, the rolling position adjustment to remove the one-sided elongated shape is performed by raising either the operating side or the driving side and lowering the other side, so that the operation is performed in opposite directions.
There is also the effect that a predetermined plate thickness can always be obtained at the center position of the plate width.

In addition, in the above embodiment, the meandering direction based on the shape detection is checked based on the actual amount of sheet deviation, but this is done to ensure the most reliable grasp of the directionality. Of course, the present invention can also be practiced without measuring the amount of plate deviation.

Further, in the above embodiment, the roll-down device is used as the adjustment means for the gap between rolls, but it may also be a roll bending device. FIG. 5 shows an embodiment using a roll bending device. That is, the discriminator 6 uses a paran ( 12) Calculate ta a by the above equation (13). If a is 0, calculate the difference ΔF( -FW Fl),
Here, FW and FD are the roll pending forces on the operating side and the driving side, and the direction in which the work roll gap is increased is positive, and the direction in which it is decreased is negative) can be calculated using the following equation.

ΔF (F=Fw Fo)= (ft+f2b+f3b2
)-") Here, fI-f3 is a coefficient determined by the dimensions of the rolling mill, the quality of the material to be rolled, etc., and b is the width of the plate.

The integrator 7B/ receives the signal ΔF from the arithmetic unit 7A' and performs the following integration in order to perform stable control.

Δp/=ΔF+fΔpdt ...... (?) Furthermore, using this ΔF', the roll-down position adjustment amount (13) on the operation side and drive side is calculated to control the roll pending force of each roll bending device 15. Output to device 14. The roll pending force control device 14 controls the roll pending forces on the operation side and the drive side respectively at ΔFW.

Correct only ΔFo. It should be noted that other configurations and methods are substantially the same as those of the embodiment described above, so corresponding parts in the figures are denoted by the same reference numerals and redundant explanations will be omitted. In this embodiment as well, good meandering control can always be performed as in the previous embodiment, except that the means for adjusting the inter-roll gap is different.

〔Effect of the invention〕

As described above, according to the present invention, since the one-sided elongation shape of the rolled material in the initial state of meandering, which has a large meandering prevention effect, is regarded as the meandering prevention condition, it is possible to effectively prevent meandering, and as a result, This provides excellent effects such as improving rolling efficiency and operational stability, and reducing equipment damage.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view showing the occurrence of plate shear, Figure 2 is a plan view of the same, and Figure 3 is the correspondence between the (14) asymmetric component of the elongation rate difference of the rolled material and the plate shear due to meandering. FIG. 4 is a system diagram showing one embodiment of the present invention, and FIG. 5 is a system diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Rolled material, 3... Shape detector, End... Sheet deviation amount detector, 20... Calculating means, 6... Discriminator, 7A,
7A'...Arithmetic unit, 7B, 7B'...Integrator, 8.
14... Control means (rolling device, roll bending device), 12... Work roll. Agent Patent Attorney Tatsuyuki Unuma (15) Condolences 1 Diagram ■ Continued from page 1 0 Invention Person Assistance - 3-1-1 Saiwai-cho, Yahitachi-shi Stock % formula % Hitachi University University Mika-cho 5-2-1 Hitachi, Ltd., Inumika Factory ■Applicant: Hitachi, Ltd., 5-1 Marunouchi-chome, Chiyoda-ku, Tokyo

Claims (1)

[Claims] 1. In rolling a plate, a shape detector detects an asymmetrical component of the elongation rate difference with respect to the center of the plate width, which causes plate displacement, and removes the detected asymmetrical component. A method for preventing meandering in plate rolling, characterized by: adjusting the gap between work rolls in the width direction of the plate. 2. The method for preventing meandering in plate rolling according to claim 1, wherein the detection of the direction of sheet deviation based on the non-target component detected by the shape detector is checked using the actual measured value of sheet deviation. 3. The method for preventing meandering in sheet rolling according to claim 1, wherein the gap adjustment in the sheet width direction of the work rolls is performed by roll bending or roll rolling. 4. A shape detector that detects an asymmetrical component of the difference in elongation rate of the rolled material with respect to the center of the plate width, and based on the asymmetrical component of the difference in elongation rate, determines a phase state in which plate displacement occurs;
a calculation means for calculating the inter-roll gap adjustment amount necessary to remove the asymmetric component of the elongation difference based on the discrimination value; 1. A meandering prevention device for sheet rolling, comprising: control means for controlling a gap between work rolls necessary for removing an asymmetrical component of a difference in elongation rate. 5. In plate rolling according to claim 4, wherein the calculating means is connected to a plate deviation detector for checking the correspondence between the one-sided elongation measured by the shape detector and the plate deviation direction. Meandering prevention device. 6. The meandering prevention device in plate rolling according to claim 4, wherein the control means is a roll rolling device or a roll bending device.