JPH05214449A - Meandering correction method of strip continuous treatment line - Google Patents

Abstract

PURPOSE:To securely and efficiently correct the meandering of the strip by controlling the meandering correction of the upstream side steering roll by taking into consideration the meandering quantity of the inlet side and the downstream side meandering quantity. CONSTITUTION:In the strip continuous treatment line to achieve the treatment such as the heat treatment of the strip 5 to be supportingly carried by a carrying roll 6, two or more steering rolls 1, 2 are arranged on the upstream and downstream side to correct the meandering of the strip 5. Meandering detectors 10, 11, 20, 21 are arranged to the specified positions respectively on the upstream and downstream sides for these steering rolls 1, 2, and the detected meandering quantity is outputted to arithmetic units 3, 4. Here, the meandering quantity of the strip is operated on the basis of these outputted values. In addition, the meandering correction of the steering roll 1 is controlled so that the subtraction of the meandering quantity on the inlet side from the meandering correction to be corrected may be approximately equal to the absolute value of the meandering quantity on the inlet side of the downstream side steering roll 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a meandering correction method in a continuous strip processing line.

[0002]

2. Description of the Related Art Strips such as thin steel plates and plastic films are continuously transported while being supported by a number of transport rolls, and are continuously processed by heat treatment or surface treatment. Due to a defective shape of the strip, a defective shape of the strip that occurs during processing, and a defective connection of the strip, a meandering phenomenon in which the strip deviates from the center of the transport path line often occurs. Such meandering hinders the normal conveyance of the strip, and when the meandering amount exceeds a certain value, various problems such as breakage of the strip may occur and the conveyance may become impossible.

Therefore, various methods for correcting the meandering of the strip have been proposed in the continuous strip processing line. As a typical method thereof, there is a method of correcting meandering using a strip meandering correcting device, which is generally called a steering roll, and which includes a conveying roll and a mechanism for tilting the conveying roll.

6 to 8 show various types of steering rolls, each of which has a fulcrum 7 as shown.
A roll 9 is fixed and supported on a pedestal 8 that tilts about the roll 8, and the pedestal 8 is tilted while the strip 5 is orbiting on the roll 9, and the passing position of the strip 5 in the width direction is changed by the tilting operation. For example, in the heating furnace of the continuous annealing line, as shown in FIG.
It is installed together with the meandering detectors 12 and 22 at a ratio of one to ten. In such a device configuration, first, the meandering detectors 12 and 22 detect the actual meandering, and the detected values of the meandering detectors 12 and 22 and the control target value (pass line) are detected for each steering roll 1 and 2. The feedback control has been performed in which the deviation from the center is calculated, the deviation is input to the steering roll driving device, and the steering roll is driven so that the deviation becomes zero.

[0005]

By the way, the meandering amount of the strip normally increases as it goes downstream of the pass line. For this reason, in the above-described conventional method in which a plurality of steering rolls are used and the meandering correction is controlled separately, there are many cases where the meandering correction of the strip cannot be sufficiently performed in the downstream steering roll. As an example of this, using the case of the heating furnace of the continuous annealing line shown in FIG. 9 above, strip: thickness
Under the conditions of 1.2 mm, width: 1500 mm, its conveying speed: 5 m / s, and maximum steering roll meandering correction amount: 100 mm, the strip meandering condition is as shown in FIG. In the figure, the dotted line C shows the meandering situation when the steering roll is not used, the solid line B shows the meandering situation when the steering roll is used, or the upstream steering roll 1 and the downstream steering roll 2 The position is shown. As shown in the figure, the meandering amount is as small as 20 mm at the entrance of the meandering control section (the origin of the horizontal axis in the figure). Looking at the meandering situation when the steering roll 1 on the upstream side is not used, the meandering amount tends to increase toward the downstream side of the pass line as described above, and the meandering amount tends to increase on the inlet side of the steering roll 2 on the downstream side. It is as large as 200 mm and is in a dangerous condition on the strip. Next, looking at the meandering situation when the upstream steering roll 1 is used on the same strip passing plate, the amount of meandering immediately before the upstream steering roll 1 is 30 mm, and the maximum meandering correction capability is 100 mm. In the steering roll 1, the strip is controlled to meander in the center of the pass line. But,
On the downstream side of the upstream steering roll 1, the meandering amount tends to increase again, and the meandering amount at the position immediately before the downstream steering roll 2 is 170 mm. Since the maximum meandering correction amount of the downstream side steering roll 2 is 100 mm, which is the same as that on the upstream side, the meandering correction ability is insufficient, and a meandering of 70 mm occurs on the exit side of the steering roll 2. As described above, in the conventional meandering control method, there are many cases where the meandering cannot be completely corrected.

To address this problem, it is conceivable to add a large number of steering rolls in the line to shorten the distance between the steering rolls, but since the steering rolls are expensive, the number of installed steering rolls is limited as described above. Due to restrictions, it is currently difficult to solve the above problems.

Further, focusing on the usage conditions of the upstream and downstream steering rolls, in the above conventional method,
There is also a problem that the amount of correction of the meandering of the steering rolls of both becomes unbalanced. That is, when this is also explained using the above example, in the steering roll 1 on the upstream side,
The maximum meandering correction amount is 100 mm, while the actual correction amount is 3
It is only 0 mm and the steering ability is not fully utilized.
On the other hand, the steering roll 2 on the downstream side has a meandering amount greater than the required meandering correction amount, and the steering ability is insufficient. In this way, the meandering correction ability of both steering rolls is unbalanced.

The present invention intends to provide a meandering correction method capable of fully utilizing the meandering correction capability of the steering roll on the upstream side and preventing the strip meandering on the downstream side of the pass line from becoming dangerous. It is what

[0009]

FIG. 5 is a graph showing a general relationship between the amount of strip meandering and the distance in the pass line direction. In the figure, the solid line C is the meandering condition when the steering roll is not used, is the steering roll on the upstream side,
Indicate the positions of the steering rolls on the downstream side. As shown in the figure, although the strip meandering amount increases toward the downstream side, conventionally, as described above, the strip is simply corrected to the center of the pass line in the steering roll on the upstream side. D2
Will be).

However, in such an upstream steering roll control method, as shown in FIG. 10, the meandering correction cannot be caught up in the downstream steering roll.

Therefore, the present inventors first paid attention to the meandering correction amount of the downstream steering roll, and controlled the correction amount of the upstream steering roll so as to suppress the meandering of the downstream side within the maximum correction amount. The present invention was devised.

That is, according to the present invention, the meandering correction amount of the steering roll is an amount obtained by subtracting the meandering amount on the steering roll entry side from the correction amount to be corrected, and another steering roll immediately downstream of the steering roll. It is characterized in that the absolute value of the strip meandering amount on the entry side of is controlled to be substantially the same. Figure 5
In the present invention, the correction reference of the steering roll on the upstream side is not set to the center of the pass line, but the correction amount (X) to be corrected for meandering is used to determine the meandering amount (D2) on the steering roll entrance side. The subtracted amount (X1),
The absolute value with respect to the strip meandering amount (X2) on the inlet side of the steering roll on the downstream side is controlled to be substantially the same. The strip meandering after such control is as shown by the dotted line A, and the correction amount required by the steering wheel on the downstream side is at least smaller than the correction amount on the upstream side, and can sufficiently catch up with the meandering increasing on the downstream side. Has become.

Further, in the present invention, the meandering amount (D2) on the upstream side of the steering roll on the upstream side from the correction amount X to be corrected for meandering.
Since the absolute value of the subtracted amount (X1) and the strip meandering amount (X2) on the downstream side of the steering roll are substantially the same, the strip meandering amount (D) is detected in advance,
It is necessary to grasp the meandering condition represented by the solid line C in the figure. Therefore, two or more meandering detectors are arranged at a predetermined distance on the strip continuous processing line, and based on the output value of the meandering detector, it is optional. A configuration is adopted in which the strip meandering amount at a location is calculated by, for example, an arithmetic device. Although the number of meandering detectors and the installation location can be variously considered, it is preferable to arrange the installation location on the upstream side of the steering roll in order to quickly correct the meandering of the strip. It is desirable that the meandering detector (1) is installed so as to satisfy the following formula (1) in order to secure a delay time until the steering roll performs meandering control. Explaining this equation, the right side is changed from the swing angle 0 of the steering roll to the maximum swing angle on one side (H / 2), that is, from the correction amount 0 of the steering roll to (H / 2). Time (H / 2v + Δ) that is the sum of the time required for ((H / 2) / v) and the time required for the operation of the control system (Δt)
Since it is the product of t) and the strip transport speed, it is the distance that the strip moves within the unit time (H / 2v + Δt). Therefore, in order to secure the time to actually drive the steering roll to the maximum swing angle after the meandering detector on the upstream side detects the meandering, the meandering detector on the more upstream side has a distance equal to or more than the right side from the steering roll, that is, It would be desirable to place it at a distance of S.

[0014]

[Equation 1]

Further, when the strip meandering amount increases in proportion to the distance in the pass line direction as shown in FIG. 5 or has a relationship close thereto, the strip meandering amount is the upstream side steering roll and the downstream side steering roll. If the steering roll on the upstream side is controlled so as to be 0 at an intermediate position (L / 2) between and, the absolute values of (X1) and (X2) will be the same or substantially the same. This indicates that the upstream steering roll may be corrected by meandering by (X) and moved in parallel so that the strip meandering state becomes from the solid line C to the dotted line A in FIG. Under the condition that the amount of meandering is 0 at the position of L / 2),
The steering roll meandering correction amount (X) on the upstream side is obtained by the following equation (2) which is a function of (S), (D1), (D2) and (L) shown below.

[0016]

[Equation 2]

When the meandering correction according to the equation (2) is performed, the strip meandering amount D3 'on the downstream steering roll entrance side after the meandering correction is obtained by the following equation (3). Therefore, from the output of the meandering detector. By constantly comparing the calculated value of D3 with D3 'calculated from the following equation (3), it is possible to perform correction so as to increase the accuracy of calculation of the meandering correction amount. The arithmetic processing as described above is usually performed using an arithmetic device.

[0018]

[Equation 3]

In addition, in the present invention, minute fluctuations in the output of the meandering detector caused by minute meandering of the strip to such an extent that it does not cause a problem on the threading of the strip, ear alignment of the strip, and the like cause disturbance of the meandering control system. In order to prevent the above-mentioned action, the output of the meandering detector may be subjected to a moving average process in the arithmetic unit to increase the accuracy of detecting the meandering amount of the strip.

The terms "upstream" and "downstream" used in the present invention indicate the positional relationships among the steering rolls, between the meandering detectors, and between the steering rolls and the meandering detectors. It does not indicate that it is upstream or downstream of itself.

[0021]

Embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following examples.

FIG. 1 shows an example of the construction of an apparatus in a continuous annealing line heating furnace capable of carrying out the method of the present invention. In the figure, 1 is an upstream steering roll, 2 is a downstream steering roll, 10, 11, 20. 21 is a meandering detector, 3 and 4 are arithmetic units,
5 is a strip and 6 is a transport roll. In addition, this embodiment is an example of correction of meandering caused by an ear wave, and its execution conditions are exactly the same as those of the conventional example shown in FIG. 10, that is, strip: thickness 1.2 mm, width: 1500 mm, and its conveying speed: 5 m / s. ,
The maximum amount of meandering correction of the steering roll is 100 mm.

The meandering detectors 10 and 11 are steering rolls 1.
Two upstream side meandering detectors are installed.
10 is disposed at a position where the distance (S) from the steering roll 1 is 20 m. This satisfies the above formula (1), and is a sufficient distance to secure the delay time until the steering roll 1 performs the meandering control.

The meandering detector 11 on the downstream side is arranged at a position within (S / 2) from the steering roll 1. This is because it is preferable to set a certain distance between the meandering detectors 10 and 11 in order to calculate the strip meandering amount at an arbitrary position.

The meandering detectors 20 and 21 of the downstream side steering roll 2 have the same structure.

FIG. 2 shows the meandering condition in the above-mentioned device configuration.

In FIG. 2, the horizontal axis is the length in the pass line direction, and the vertical axis is the deviation from the center of the pass line, that is, the amount of meandering. The symbol Δ in the figure indicates the position of the transport roll, and the symbol indicates the position of the steering roll.

Further, the strip conveying direction is the direction of the arrow, and the dotted line B in the figure shows the meandering condition when the steering roll is used in the conventional control method.

As shown in the figure, in this embodiment, the meandering amount of the strip and the distance in the pass line direction are in a proportional relationship, and the steering rolls 1, 2 are calculated by using the above equation (2).
The meandering control of. Numerical values are D1: 0.02m, D respectively
It was 2: 0.03 m, S: 20 m, L: 280 m. Above (2)
The calculation of the formula was performed by a calculation device.

As a result, the meandering condition shown by the solid line A in the figure is reached, and the meandering generated immediately after the steering roll is 5 mm at maximum.
Controlled to the value of 70 mm in the conventional method of FIG.
It has been greatly reduced. Furthermore, focusing on the usage conditions of the steering rolls, the steering amounts of the steering rolls 1 and 2 (symbols in FIG. 2) were both 100 mm, which was well balanced.

The above-mentioned effects were similarly observed in other portions of the continuous annealing line and the continuous hot-dip galvanizing line. Fig. 3 is a schematic diagram of the continuous annealing line. As a result of testing the inlet side loop tower portion, heating zone portion, cooling zone portion, overaging zone portion and outlet side loop tower portion in the same figure, strip passing Not only when the speed is high, but also when the strip conveying speed is changed or the annealing temperature is changed, the meandering amount of the strip can be reduced to about 50% compared to the conventional case, and the strip running stability is significantly improved.

FIG. 4 is a schematic diagram of the continuous hot-dip galvanizing line. Tests were performed at the inlet side loop tower portion, heating zone portion, soaking zone, cooling zone portion, and outlet side loop tower portion in the figure. As a result, similar to the above example, when the strip running speed is high, the meandering control effect is remarkably exhibited, the maximum meandering amount is reduced to about 50% of the conventional average, and the strip breakage, which is considered to be directly caused by the meandering, does not occur. lost. As a result, the strip running stability is improved and the operation efficiency of the line is about 1
It improved by 0%.

Further, the present invention can be applied to any equipment that employs a steering roll for controlling the meandering of the strip, so that the strip is not limited to a continuous hot dip galvanizing line or a continuous annealing line, It can be applied to painting and printing lines.

When the present invention is applied, the existing steering roll device can be used as it is, which is of course economically advantageous.

[0035]

As described above, according to the meandering correcting method of the present invention, the meandering correcting ability of the steering roll on the upstream side is fully utilized, and the strip meandering on the downstream side of the pass line is in a dangerous state. Things can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a device configuration in a continuous annealing line heating furnace capable of carrying out the present invention.

FIG. 2 is a graph showing a strip meandering condition in the configuration of FIG.

FIG. 3 is a schematic diagram showing the entire continuous annealing line.

FIG. 4 is a schematic diagram showing an entire continuous hot-dip galvanizing line.

FIG. 5 is a graph showing a general relationship between the strip meandering amount and the distance in the pass line direction.

FIG. 6 is an explanatory diagram showing a device configuration of a steering roll.

FIG. 7 is an explanatory diagram showing a device configuration of a steering roll.

FIG. 8 is an explanatory diagram showing a device configuration of a steering roll.

FIG. 9 is a schematic view showing the arrangement of conventional steering rolls in a continuous annealing line heating furnace.

FIG. 10 is a graph showing a strip meandering situation in the configuration of FIG.

[Explanation of symbols]

 1 Upstream-side steering roll 2 Downstream-side steering roll 3, 4 Computing device 5 Strip 6 Conveyor roll

Claims (2)

[Claims] 1. A strip continuous processing line is provided with two or more meandering detectors at a predetermined distance, and a strip meandering amount at an arbitrary position is calculated based on an output value of the meandering detector. The steering roll meandering correction amount is an amount obtained by subtracting the meandering amount on the steering roll entrance side from the correction amount to be meandered and the strip meandering quantity on the entrance side of another steering roll immediately downstream of the steering roll. A meandering correction method for a continuous strip processing line, characterized in that the absolute values are controlled to be substantially the same. 2. A meandering detector that satisfies at least the following expression (1) as an installation location on the upstream side of the steering roll arranged in the strip continuous processing line, the meandering detector and the steering roll. With other meandering detectors located between, and based on the output value of the meandering detector,
A meandering correction method for a strip continuous processing line, characterized in that the meandering strip amount at an arbitrary position is calculated and the steering roll meandering correction amount is controlled using the following equation (2). [Equation 1] [Equation 2]