JP2633430B2 - Method and apparatus for correcting meandering of strip in continuous hot metal plating line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for correcting meandering of a strip in a continuous hot-dip metal plating line.

[0002]

2. Description of the Related Art In a plating apparatus used in a continuous hot-dip metal plating line, as shown in FIG. 4, a strip 1 advanced from a reduction annealing furnace (not shown) to a plating bath 3 is immersed in the plating bath 3. Thereafter, the sink roll 2 is disposed in the plating bath 3 so as to be pulled out of the plating bath 3 almost vertically while changing its traveling direction.

Conventionally, this sink roll 2 has a strip 1
An idle roll that is rotationally driven by the roller 1 is provided with a groove 4 (referred to as a groove) as shown in FIG. For this reason, there is a problem that traces (referred to as groove marks) of the grooves 4 are formed on the surface of the strip 1 on the side in contact with the sink roll 2, and the plating quality is deteriorated.

In order to eliminate these groove marks, Japanese Utility Model Laid-Open Publication No. Hei 3-74656 discloses that a sink roll is arranged as close as possible to the plating bath surface to eliminate the groove, and is provided via a transmission shaft from outside the plating bath. There has been proposed a device which is driven by a motor. However, it has not been possible to control or prevent meandering only by driving a grooveless roll having a flat roll body.

JP-A-1-287262 discloses a method for producing a hot-dip metal-coated steel strip while controlling the meandering of the steel strip, which includes a pretreatment furnace, a hot-dip pot, and a molten metal weight control device. In a method for continuously producing a hot-dip metal-plated steel strip with a hot-dip metal plating apparatus, a steering roll device is provided at a rear portion of the pretreatment furnace and a steel strip meandering detection device is provided at a steel strip exit side of the roll device, and the vehicle is run. A method for manufacturing a continuous hot-dip metal-plated steel strip, comprising continuously detecting a meandering state of a steel strip, and manufacturing a hot-dip metal-plated steel strip while steering-controlling the steel strip with a steering roll device according to the detected value. Has been proposed. However, this method does not work effectively for meandering caused by rolls in the bath and is not enough to control the strip position at the gas wiping point.

In Japanese Utility Model Application Laid-Open No. 55-142576, the inside of a sink roll for rotatably supporting a strip is divided into a plurality of chambers, and a hole or a slit is formed in a peripheral surface of the sink roll so that a liquid can flow therethrough. A strip meandering correction device by sink roll internal pressure control, wherein a liquid suction and supply device is connected to a shaft of the sink roll so that the plurality of indoor pressures can be controlled independently of each other. Have been. However, this device requires the pumping of molten zinc and a large-scale device for controlling the same, and the control response is not sufficient. Further, if the threading tension changes, the control response greatly changes, so that it is difficult to perform delicate control.

[0007]

As described above, in order to eliminate the groove mark and improve the quality of the plated surface, it is necessary to eliminate the groove provided on the sink roll. Even if the sink roll is driven, even though the sink roll is driven, the meandering of the strip occurs at the sink roll portion, and stable operation cannot be performed, which causes a decrease in productivity such as cutting of the strip due to the meandering, a reduction in plating surface quality and an increase in cost. There's a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus which can effectively prevent the strip from meandering at a sink roll portion, and thereby make it possible to use a grooveless sink roll.

[0009]

According to the method of the present invention, a grooveless roll is used as a sink roll, and the peripheral speed of the sink roll is driven by a sink roll driving device in synchronization with the strip speed. The meandering amount, meandering speed and meandering direction occurring in the strip in the vicinity are detected, and in accordance with these detected values, the sink roll is tilted in a direction to correct them, and the meandering of the strip in the sink roll part is corrected. A meandering correction method for a strip in a continuous molten metal plating line, characterized in that: The device of the present invention includes a sink roll that is a grooveless roll, a device that tiltably supports the sink roll, and a drive device for the sink roll, and a control system that drives the peripheral speed of the sink roll in synchronization with the strip speed. And, the meandering amount, meandering speed and meandering direction occurring in the strip near the sink roll are detected, and in accordance with these detected values, the sink roll is tilted in a direction to correct them,
A control system that corrects the meandering of the strip in the sink roll part. A device for correcting the meandering of a strip in a continuous molten metal plating line.

The apparatus of the present invention includes a device for tiltably supporting a sink roll, a drive device for the sink roll, a control system for driving the peripheral speed of the sink roll in synchronization with the strip speed, and a vicinity of the sink roll. Control to detect the amount of meandering, meandering speed and meandering direction occurring in the strip, tilt the sink roll in a direction to correct them according to these detected values, and correct the meandering of the strip at the sink roll part. A meandering correction device for a strip in a continuous hot-dip metal plating line characterized by comprising a system, and a gravure roll is used as a sink roll.

[0011]

[Operation] The present inventors conducted various experiments and examinations on a meandering correction control of a strip in a sink roll portion using a grooveless sink roll by using an experimental device capable of simulating a plating operation of a real line. Was. as a result,
The grooveless sink is driven by driving the sink roll peripheral speed (SS) and the strip speed (LS) in a state of SS ≧ LS and tilting the sink roll in a direction to correct the meandering amount and meandering direction according to the meandering amount and meandering direction. It has been found that it is possible to correct the meandering of the strip in the roll section and to run the strip at a predetermined position.

On the other hand, when the sink roll is used as a conventional idle roll, the meandering of the strip cannot be corrected and cannot be controlled, and the sink roll is driven in synchronization with the running speed of the strip. If it is only performed, the strip is likely to meander even due to a very small strip shape defect, and once the meandering occurs, the strip will come off from the roll body instantly (the roll is disengaged), and it will not be practically used. This was also confirmed in this experiment.

The present invention has been completed based on the above findings. Hereinafter, the principle of the present invention will be described. The present invention
While driving the sink roll in synchronization with the strip speed, tilting the sink roll in a direction to correct these according to the amount of meandering, meandering speed and meandering direction that is occurring,
Therefore, the meandering of the strip in the grooveless sink roll portion is quickly corrected and the strip is run at a predetermined position.

FIG. 2 schematically shows a method of correcting the meandering of the strip 1 generated in the sink roll 2 portion. For example, when the strip 1 is meandering to the right (R side), the right tension of the strip 1 is adjusted. In order to correct the meandering by tilting the sink roll 2 to the right so that is larger, the tilting amount and the tilting speed are controlled according to the meandering amount, meandering speed and meandering direction of the strip 1. As a more specific meandering control, even when the strip 1 is meandering to the right (R side), if the direction in which the strip 1 is to move at this time is the left side (L side), the sink roll is adjusted according to the meandering speed. 2 is operated in a direction to alleviate the rightward tilting (rightward upward direction) to control the sink roll 2 to maintain the tilting when the strip returns to the predetermined running position. However, without such control, if the sink roll 2 is kept right-down just because the strip 1 is on the right side, the strip 1 has gone beyond a predetermined running position and is now on the opposite left side (L
Side) and cannot be controlled.

[0015]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the meandering control device of the present invention. In FIG. 1, a strip edge sensor 5 detects a traveling position of the strip 1 and outputs the detected traveling position to a calculator I6. The arithmetic unit I6 calculates the meandering amount, meandering speed, and meandering direction from the detection value of the strip edge sensor 5 and the strip width signal W, and calculates the rotation angle of the motor 7 for tilting the sink roll 2 necessary for correcting the meandering. The rotation amount corresponding to the tilt angle of the sink roll 2) is calculated from the value detected by the encoder 9 and the meandering amount of the strip 1 at that time, and the tilt direction of the strip 1 is calculated from the value detected by the strip edge sensor 5. And outputs it to the controller I8.

The controller I8 controls the amount and direction of rotation of the motor 7 for tilting the sink roll 2 based on a command from the calculator I6. The driving force output from the motor 7 rotates the sink roll tilting gear 16 via the transmission 14 and the intermediate shaft 15, thereby raising and lowering the sink roll support shaft 17 (when the right support shaft 17 is lowered, the left support shaft 17 Is raised).

As described above, the running position of the strip is constantly detected, and control is performed so that the strip can run at the predetermined running position using the meandering amount, meandering speed, meandering direction, and tilt amount of the sink roll. On the other hand, the rotation speed of the motor 10 for rotating and driving the sink roll 2 is detected by the encoder 11 and output to the computing unit II12. In the arithmetic unit II12, the strip speed L
After calculating the sink roll 2 peripheral speed SS from S and the sink roll 2 rotational speed detected by the encoder 11, these are compared to calculate the sink roll 2 rotational speed at which the sink roll peripheral speed SS becomes the same as the strip speed LS. And controller II
Output to 13. The controller II13 controls the rotation speed of the motor 10.

Although an example in which the sink roll is tilted and driven by a motor and uses a gear mechanism has been described as an actuator for tilting the sink roll, an electric or pneumatic cylinder or the like may be used instead. . As the strip edge sensor, an optical type of light emitting / receiving type, an eddy current type, or a touch roll type (a device in which a roll is constantly brought into contact with a strip edge and the displacement of the roll is detected) is used. Any method may be used, such as photographing a part and performing image processing to detect the meandering amount.

Further, the meandering control of the strip has been described by a method of tilting the sink roll in the vertical direction.
As shown in (1), the sink roll may be tilted in a horizontal plane or in a plane inclined at an arbitrary angle.

[0020]

The following effects can be obtained by controlling the meandering of the strip in the sink roll section to which the present invention is applied. (1) A grooveless sink roll can be used, and a product with excellent plating quality without groove marks can be manufactured. (2) Grooveless sink rolls can be used, and plating equipment can be replaced and maintenance costs can be eliminated due to groove clogging that has occurred with conventional sink rolls, thereby reducing costs.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the apparatus of the present invention.

FIG. 2 is an explanatory diagram schematically showing meandering control in a sink roll unit according to the present invention.

FIG. 3 is an explanatory diagram showing an application example of meandering control of the present invention.

FIG. 4 is an explanatory view of a conventional typical plating apparatus.

FIG. 5 is an explanatory view of a groove of a conventional sink roll body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Strip 2 Sink roll 3 Plating bath 4 Groove of sink roll body 5 Strip edge sensor 6 Computing unit 7 Motor 8 Controller I 9 Encoder 10 Motor 11 Encoder 12 Computing unit II 13 Controller II 14 Transmission 15 Intermediate shaft 16 Gear 17 Support shaft SS Sink roll peripheral speed LS Strip speed W Strip width L Left side R Right side

Claims (2)

(57) [Claims] 1. A grooveless roll is used as a sink roll, a peripheral speed of the sink roll is driven by a sink roll driving device in synchronization with a strip speed, and a meandering amount generated in the strip near the sink roll is determined. A continuous molten metal plating line characterized by detecting a meandering speed and meandering direction, inclining a sink roll in a direction to correct them according to the detected values, and correcting meandering of a strip at a sink roll part. Correction method of strip meandering in 2. A sink roll, which is a grooveless roll, a device that tiltably supports the sink roll, and a control system that includes a sink roll driving device and drives the peripheral speed of the sink roll in synchronization with the strip speed. The meandering amount, meandering speed and meandering direction occurring in the strip near the sink roll are detected, and in accordance with these detected values, the sink roll is tilted in a direction to correct them, and the strip at the sink roll part is tilted. A meandering correction device for a continuous hot-dip metal plating line, comprising: a control system for correcting meandering.