JP5598132B2 - Steel plate passing method and steel plate conveying device in continuous processing line - Google Patents

Description

  The present invention relates to a method and apparatus for stably passing a sheet on a transport roll that first comes into contact with a steel plate after passing through a treatment liquid in a continuous processing line of the steel plate in which the steel plate is subjected to processing such as plating, cleaning, and water cooling. About.

  In continuous processing lines for steel sheets such as pickling lines, plating lines, and annealing lines, the steel sheet has various processes such as plating, cleaning, water cooling, etc., that is, a process in which the steel sheet is immersed in a processing solution. . In such a process, the steel sheet is often pulled up from the treatment liquid after passing through the treatment liquid (see FIG. 1). Since the accompanying treatment liquid adheres to the surface of the steel sheet immediately after passing through the treatment liquid, the steel sheet and the conveyance roll A film of the processing liquid (liquid film) is formed between the two. When the liquid film is formed thick, the grip force between the steel plate and the transport roll is reduced.

  Increasing the conveying speed is advantageous in terms of improving productivity. However, the liquid film changes depending on the amount of the accompanying liquid, and the amount of the accompanying liquid increases as the conveying speed increases, and the grip force between the steel plate and the conveying roll decreases. When the grip force is weak, the steel plate is likely to meander, and stable plate passing becomes difficult.

  In addition, the continuous processing line is equipped with various equipment such as welding equipment and finishing equipment, and depending on the situation, it may be transported at a low speed, so that even if the transport speed decreases, it can be stably fed. desirable. On the other hand, the slower the transport speed, the smaller the amount of liquid that accompanies and the grip force between the steel plate and the transport roll increases. If the grip force is excessive, wrinkles are likely to occur in the steel sheet, making it difficult to stably pass the plate.

  As a technique for stably passing a steel plate, Patent Document 1 discloses that a pressing roll is installed on a transport roll in a processing liquid, and the liquid film thickness formed during high-speed passing is smaller than the transport roll surface roughness Rmax. A technique for preventing meandering by setting the pressing pressure of the pressing roll is proposed. Patent Document 2 proposes a method for managing the surface roughness of the transport roll.

JP 09-87816 A JP 2008-156695 A

  Patent Document 1 is a stable plate passing technique in a transport roll arranged in a processing liquid, and a stable plate passing technique for a steel plate in a transport roll after being pulled up from the processing liquid is not proposed.

  Patent Document 2 is effective when the conveyance speed is limited to some extent, but cannot sufficiently exhibit the effect in a line where the conveyance speed changes in a wide range. For example, if the management range of the surface roughness is set according to the liquid film thickness in the area where the conveyance speed is high, meandering due to insufficient grip can be prevented in the area where the conveyance speed is high, but the grip force is excessive in the area where the conveyance speed is low. As a result, wrinkles are generated in the steel sheet, resulting in poor sheet passing.

  The present invention solves the above-described problems and is a continuous processing line that can stably pass even if the transfer speed is high, or can stably pass regardless of the transfer speed even if the transfer speed is changed in a wide range from low speed to high speed. It is an object of the present invention to provide a sheet passing method and a sheet passing device.

  Means of the present invention for solving the above problems are as follows.

[1] In a continuous processing line of a steel plate having a step of immersing the steel plate in the processing liquid and performing the processing, after passing through the processing liquid, the transport roll that first comes into contact with the steel plate pulled up from the processing liquid And one or more pressing forces arranged to face the steel plate contact portion of the transport roll and allowing the pressure roll to be adjusted,
A steel plate passing method in a continuous processing line, wherein the pressing force of the pressing roll is increased according to the steel plate transport speed when the steel plate transport speed becomes equal to or higher than a predetermined speed (v0) determined in advance.

  [2] Further, before the steel plate pulled up from the treatment liquid is brought into contact with the transport roll, the continuous processing line has a surface on the side in contact with the transport roll of the steel plate, or further, the steel plate and the pressing roll. The continuous surface according to [1], wherein a spray capable of ejecting a liquid is provided on a surface on the contact side, and the liquid is ejected from the spray when a steel plate conveyance speed is equal to or lower than a predetermined speed (v1). Steel plate passing method in the processing line.

  [3] It is arranged in a continuous processing line of a steel plate having a step of immersing the steel plate in the processing liquid and performing the processing, and a steel roll pulled up from the processing liquid first comes into contact with the steel plate contact portion of the transporting roll. One or more pressing rolls arranged facing each other, pressure adjusting means for adjusting the pressing force of the pressing roll, and calculating the pressing force of the pressing roll based on the steel sheet conveying speed, A steel plate conveying apparatus comprising: a control device that commands the pressure adjusting means.

  [4] Further, on the treatment liquid side of the contact portion between the steel plate pulled up from the treatment liquid and the transport roll, on the side where the transport roll contacts the steel plate, or further on the side where the pressing roll contacts the steel plate A spray for injecting a liquid, and an adjusting means for injecting and stopping the spray.The control device further determines spray injection or stop based on a steel plate conveyance speed, and determines the result of the determination. The steel sheet conveying apparatus according to [3], further comprising means for instructing an injection adjusting means.

  According to the present invention, when the conveying speed becomes high, the pressurizing force of the pressing roll is increased according to the conveying speed, thereby preventing an increase in the liquid film thickness between the conveying roll and the steel sheet. Even if the conveyance speed becomes high, stable feeding can be performed. Furthermore, when the transport speed becomes low, it is possible to prevent a decrease in the liquid film thickness between the transport roll and the steel sheet by spraying the spray installed before the transport roll, even if the transport speed decreases. Stable threading is possible.

It is the schematic explaining the principal part of a steel plate conveying apparatus provided with a conveyance roll and a pressing roll. It is explanatory drawing which shows this invention by contrast with the prior art the relationship between a conveyance speed, the liquid film thickness between a steel plate, and a conveyance roll, the relationship between a conveyance speed, a pressing roll pressure, a conveyance speed, and spray injection. It is a figure explaining the steel plate conveyance apparatus which concerns on embodiment of this invention. It is a figure explaining another arrangement | positioning form of the pressing roll of the steel plate conveying apparatus which concerns on embodiment of this invention. It is a figure explaining the effect of this invention.

  Hereinafter, embodiments of the present invention will be described.

  In FIG. 2, (a) is a conceptual diagram explaining the relationship between the conveyance speed and the liquid film thickness between the steel plate and the conveyance roll, (b) is a diagram explaining the relationship between the conveyance speed and the pressing roll pressure, and (c) is The figure explaining the relationship between a conveyance speed and the presence or absence of spray injection, and the figure which shows the relationship between pressing roll pressure, A solid line is this invention and a broken line is a prior art.

  The operation of the present invention will be described with reference to FIG.

  In the prior art, the pressure of the pressing roll is a constant pressure, and the liquid is not sprayed by the spray before contacting the transport roll. The liquid film thickness between the steel plate and the transport roll tends to be thicker as the transport speed is faster, and thinner as the transport speed is slower. Therefore, the grip force between the steel plate and the transport roll decreases as the transport speed increases. Threading such as meandering is more likely to occur. Further, when the conveyance speed is low, the grip force between the steel sheet and the conveyance roll increases, and there is a problem that wrinkles (squeezing) are generated due to the small meandering of the steel sheet that is inevitably generated, resulting in poor sheet passing. (See the broken lines in FIGS. 2A to 2C)

  In the present invention, a threshold speed v0 for switching the pressing roll pressure from a constant pressure control to a control for increasing the pressing roll pressure in accordance with an increase in the conveying speed, and a threshold speed v1 for spraying below the conveying speed are determined in advance. Further, a method for applying the pressing roll pressure to be increased corresponding to the increase in the conveyance speed in the speed region of the threshold speed v0 or higher is determined. The pressure applied to the pressing roll in the speed range of the threshold speeds v0, v1 and the threshold speed v0 or higher is determined to be an appropriate value by observing and investigating the meandering and wrinkle generation conditions of the steel sheet transporting the continuous processing line. be able to.

  For example, a limit speed at which no meandering occurs is obtained in advance, and a speed of about 70% of the speed may be set as the threshold speed v0. By handling from a speed slower than the limit speed at which the meandering does not occur, stable passage can be performed more reliably. Further, a limit speed at which no wrinkle is generated is set in advance, and a speed of about 100 to 120% of the speed may be set as the threshold speed v1. By dealing with the limit speed at which the wrinkles do not occur or a speed higher than this speed, stable threading can be performed reliably.

  In order to obtain the above limit speed, for example, the speed may be changed at a pitch of about 1/5 to 1/20 of the maximum speed of the target continuous processing line, and the state of meandering or wrinkling may be observed. .

  Moreover, what is necessary is just to make it increase the pressurizing force of the pressing roll at the speed more than said v0 according to the increase in a steel plate conveyance speed. In addition, if a pressing force (Fmax) at which the meandering does not occur at the maximum plate speed of the continuous processing line is obtained in advance and it can be confirmed that no trouble occurs by applying the pressing force at v0, the pressing force (above v0) Fmax) may be given.

The pressing roll pressure is kept constant until the transport speed reaches a preset threshold speed v0. In the range of the speed, the roll pressure may be a pressure that is usually employed. When the transport speed is equal to or higher than the threshold speed v0, the roll pressure is increased according to the transport speed. In the speed region of the threshold speed v0 or higher, even if the transport speed is increased, an increase in the liquid film thickness between the steel plate and the transport roll is suppressed, and a plate passing defect due to meandering due to insufficient grip is eliminated.
In addition, a spray capable of injecting liquid is disposed on the surface on the side where the steel plate pulled up from the treatment liquid comes into contact with the transport roll before the transport roll (steel plate entrainment side), and the transport speed is set to a preset threshold speed v1 or less. In this case, a liquid may be sprayed on the steel plate before the transport roll to increase the liquid film thickness between the steel plate and the transport roll. As a result, it is possible to solve the problem of wrinkle generation due to insufficient liquid film thickness between the steel sheet and the transport roll in the speed region below the threshold speed v1. (Refer to the solid line in FIGS. 2A to 2C)

  In addition, by controlling the thickness of the liquid film as described above, even if the surface roughness of the transport roll is worn and reduced to some extent, a stable plate can be passed without replacing the roll.

  In addition, you may make it spray a liquid similarly to the above to the other surface of a steel plate, ie, the surface where the steel plate pulled up from the process liquid contacts the pressing roll.

  In addition to the spraying method, for example, a method of controlling the amount of liquid accompanying the steel sheet by raising and lowering the liquid level is conceivable, but the response to changes in the conveyance speed is also conceivable. Considering this, spray is preferable.

  FIG. 3 shows a steel plate conveying apparatus according to an embodiment of the present invention. In FIG. 3, 1 is a transport roll, 2 is a processing liquid, 3 is a steel plate, 4 is a pressing roll, 5 is an air cylinder, 6 is a spray, 7 is an air pipe, 8 is a pressure regulating valve, 9 is a liquid pipe, An electromagnetic valve 11 is a control device.

  The pressing roll 4 is arranged at a winding start portion of the steel plate 3 around the conveying roll 1, and adjusts the pressure of the air cylinder (pressure adjusting means) 5 supplied from the air pipe 7 with a pressure adjusting valve (pressure adjusting means) 8. By doing so, it is possible to adjust the pressure applied to the steel plate 1.

  The spray 6 is a steel plate pulled up from the treatment liquid before the conveyance roll 1 comes into contact with the steel plate (steel plate entrainment side), that is, closer to the treatment liquid side than the contact portion between the steel plate 3 pulled up from the treatment liquid and the conveyance roll 1. 3 is arranged on the side in contact with the transport roll 1 and the pressing roll 4 is in contact with the steel plate 3, and the liquid supplied from the liquid pipe 7 is opened and closed on both sides of the steel plate by opening and closing the electromagnetic valve (adjusting means) 10. Spray liquid or stop spraying.

  The control device 11 holds the relationship between the conveying speed and the corresponding pressing roll pressure as shown by the solid line in FIG. 2B, and the threshold speed v1 of the conveying speed at which spraying is performed as shown in FIG. 2C. Yes. In addition, the control apparatus 11 is input with the conveyance speed information of the steel sheet to be conveyed.

  The control device 11 obtains a pressure to be applied to the pressing roll 4 based on the input steel plate conveyance speed, and commands the obtained pressure to the pressure adjusting valve 8. Further, when the conveyance speed is equal to or lower than the threshold speed v1, the electromagnetic valve 10 is set to “ON (open)”, and when the conveyance speed exceeds the threshold speed v1, the electromagnetic valve 10 is commanded to be set to “OFF (closed)”. .

  In the apparatus shown in FIG. 3, spraying is performed on both sides of the steel plate, but spraying may be performed only on one side of the steel plate. In this case, it is necessary to arrange the spray before the contact between the transport roll and the steel plate, and to spray the liquid onto the steel plate surface on the side in contact with the transport roll.

  The pressing roll controls the amount of liquid drained along the steel plate surface. In addition to the pressing roll, for example, there is a method in which air is blown and blown away. However, since the liquid film in the width direction of the steel sheet is difficult to be uniform, it is better to use the pressing roll.

  The liquid sprayed onto the steel plate surface is preferably the same type as the liquid accompanying the steel plate surface, but it may not be the same type as long as it does not interfere with the equipment, and for example, water may be used.

  In the apparatus of FIG. 3, there is one pressing roll, but two or more pressing rolls may be arranged. In the case of two, the 1st pressing roll is arrange | positioned in the position similar to FIG. 3, and the 2nd pressing roll is arrange | positioned in the position from which a conveyance roll center angle becomes 90 degree | times or more with respect to a 1st pressing roll. It is preferable (see FIG. 4). The control of the roll pressure of each pressing roll may be the same configuration and method as those described in the apparatus of FIG.

  In an electroplating line equipped with a vertical plating facility in which a plurality of energizing rolls are arranged on the plating bath in the direction of travel of the steel plate, a pressing roll and a spray are arranged on the energizing roll (conveying roll) arranged on the plating bath. The configuration and operation are as described in FIG. The energizing roll diameter is 600 mmφ, and the pressing roll is made of rubber and has a diameter of 300 mmφ.

Using this apparatus, a steel plate having a thickness of 0.15 to 0.30 mm and a width of 800 to 1100 mm was passed through and electroplated. Conventionally, in this electroplating line, the maximum conveying speed of the equipment specification is 1000 mpm, but meandering is recognized when the conveying speed is 800 mpm or more, and meandering is not observed when the conveying speed is 600 mp or less. 600 mpm. Further, there was no problem of wrinkle generation up to the conveyance speed of 100 mpm, and 100 mpm was the limit speed of wrinkle generation. In the present invention, the threshold speed v1 is set to 100 mpm to prevent wrinkling. In order to prevent the sheet passing failure due meandering, the threshold speed v0 and 400mpm, 1.2kgf ^/ cm 2 pressure until 400Mpm given to the roll pressing, 400Mpm exceeded so as to be 2.0 kgf / cm ² at 1000mpm The pressure applied to the pressing roll was linearly increased corresponding to the increase in the conveyance speed. In addition, water was used as the liquid sprayed from the spray 6, and 12 sprays in total, 6 per side of the steel sheet, were arranged in the width direction of the steel sheet, and water was sprayed onto the steel sheet at an injection rate of about 10 L / min.

  FIG. 5 shows the wrinkle generation rate at low speed and the meandering generation rate at high speed in comparison with the prior art when the present invention is implemented for about one year. It can be seen that the present invention solves the problems of wrinkling at low speed and meandering at high speed, which were problems of the prior art.

  In the present invention, since the problem of meandering at high speed is eliminated, the maximum conveyance speed can be increased up to 1000 mpm.

  According to the present invention, the steel plate can be passed through a continuous processing line that can be stably threaded even if the transport speed is high, or can be stably threaded regardless of the transport speed even if the transport speed is changed in a wide range from low speed to high speed. A method and a steel plate threading device can be provided.

DESCRIPTION OF SYMBOLS 1 Transfer roll 2 Processing liquid 3 Steel plate 4 Pressing roll 5 Air cylinder 6 Spray 7 Air piping 8 Pressure adjustment valve 9 Liquid piping 10 Electromagnetic valve 11 Controller

Claims (4)

In a continuous processing line of a steel plate having a step of immersing the steel plate in the processing liquid and performing the processing, after passing through the processing liquid, the steel roll pulled up from the processing liquid is first brought into contact with the transport roll after the pulling and the transport When passing between the pressing rolls that can adjust one or more pressing forces arranged to face the steel plate contact portion of the roll,
A steel plate passing method in a continuous processing line, wherein the pressing force of the pressing roll is increased according to the steel plate transport speed when the steel plate transport speed becomes equal to or higher than a predetermined speed (v0) determined in advance. Furthermore, before the steel plate pulled up from the treatment liquid is in contact with the transport roll, the continuous processing line is a surface on the side of the steel plate in contact with the transport roll, or further on the side of the steel plate in contact with the pressing roll. A spray capable of ejecting liquid is provided on the surface of the sheet, and when the steel plate transport speed is equal to or lower than a predetermined speed (v1) which is a speed smaller than v0 , the liquid is ejected from the spray. A steel plate passing method in the continuous processing line according to claim 1. It is arranged in the continuous processing line of the steel plate which has a process of immersing the steel plate in the processing liquid and performing the processing, and the steel sheet pulled up from the processing liquid first comes into contact with the steel sheet contact portion of the transport roll. One or more arranged pressing rolls, pressure adjusting means for adjusting the pressing force of the pressing roll, and calculating the pressing force of the pressing roll based on the steel sheet conveyance speed, and calculating the calculated pressing force by the pressure adjustment And a control device that commands the means. Furthermore, the liquid is supplied to the treatment liquid side from the contact portion between the steel plate pulled up from the treatment liquid and the transport roll, the side where the transport roll contacts the steel plate, or the side where the pressing roll contacts the steel plate. In addition to the spray to be sprayed, the controller further includes adjusting means for spraying / stopping the spray, and the control device further determines and determines spray spraying or stopping based on a preset threshold speed of the steel plate conveyance speed. results steel conveying device according to claim 3, wherein the Turkey to command the adjustment means to perform injection and stopping the spray.

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