JPH05195184A - Method for correcting meandering of strip in continuous hot-dip metal coating line and device therefor - Google Patents

Abstract

PURPOSE:To effectively prevent the meandering of a strip by synchronizing the peripheral speed of a sink roll with the strip speed and making the sink roll controllable to tilt. CONSTITUTION:A computing element 16 operates the meandering quantity, meandering speed and meandering direction from the detected value of a strip edge sensor 5 and a strip width signal W. A rotating angle of a motor 7 for tilting the sink roll 2 necessary for this meandering correction is calculated from the detected value in an encoder 9 and the meandering quantity, and further, the inclining direction of the strip 1 is calculated from the detected value in the edge sensor 5. In this way, the traveling position of the strip is always detected and controlled so that the strip can travel the prescribed traveling position.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a plating apparatus used in a continuous hot metal plating line, a strip 1 which has progressed from a reduction annealing furnace (not shown) to a plating bath 3 is immersed in the plating bath 3 as shown in FIG. After that, the sink roll 2 is arranged in the plating bath 3 in order to change the traveling direction and draw the plating bath 3 almost vertically.

Conventionally, this sink roll 2 is a strip 1
An idle roll that is driven to rotate by the above-described method has been used, and the roll body has a groove 4 (referred to as a groove) as shown in FIG. 5 to suppress and prevent the meandering of the strip 1. For this reason, there is a problem that marks of the grooves 4 (referred to as groove marks) are formed on the surface of the strip 1 on the side in contact with the sink roll 2, which deteriorates the plating quality.

Therefore, as one of the measures to eliminate these groove marks, in Japanese Utility Model Laid-Open No. 3-74656, a sink roll is arranged as close to the plating bath surface as possible in order to eliminate the grooves, and a transmission shaft is provided from outside the plating bath. There has been proposed a device that is driven by. However, it is the actual situation that the meandering cannot be suppressed or prevented only by driving the grooveless roll having a flat roll body.

Further, in Japanese Patent Laid-Open No. 1-287262, a pretreatment furnace, a melting pot, and a molten metal basis weight adjusting device are provided as a method for producing a molten metal plated steel strip while controlling the meandering of the steel strip. In a method for continuously producing a hot-dip galvanized steel strip with a hot-dip galvanizing apparatus, a steering roll device is provided at the rear of the pretreatment furnace and a steel strip meandering detector is provided on the steel strip exit side of the roll device, and the strip is run. A method for producing a continuous hot-dip galvanized steel strip, characterized by continuously detecting the meandering state of the steel strip and manufacturing the hot-dip galvanized steel strip while steering the steel strip with a steering roll device according to the detected value. Is proposed. However, this method does not work effectively against meandering caused by rolls in the bath and is not sufficient to control strip position at the gas wiping point.

Further, in Japanese Utility Model Laid-Open No. 55-142576, the inside of a sink roll that rotatably supports a strip is divided into a plurality of chambers, and holes or slits are formed in the peripheral surface of the sink roll so that liquid can flow in. A strip meandering correction device by sink roll internal pressure control, characterized in that a liquid suction and supply device is connected to the shaft of the sink roll so that the plurality of chamber pressures can be independently controlled is proposed. Has been done. However, this device requires a large-scale device for pumping molten zinc and controlling it, and the control response is not sufficient. Further, when the threading tension changes, the control response changes greatly, so delicate control is difficult.

[0007]

As described above, in order to eliminate the groove marks and improve the plating surface quality, it is necessary to eliminate the grooves provided on the sink roll. Even if it is driven, even if it is driven, the meandering of the strip occurs in this sink roll part, stable operation cannot be performed, productivity lowering such as strip cutting due to meandering, deterioration of plating surface quality and cost increase. There's a problem.

It is an object of the present invention to provide a method and a device capable of effectively preventing the meandering of the strip in the sink roll portion, thereby making it possible to use a grooveless sink roll.

[0009]

According to the method of the present invention, the peripheral speed of a sink roll is driven in synchronization with the strip speed, and the meandering amount, meandering speed and meandering method occurring in the strip near the sink roll are controlled. A method for correcting the meandering of a strip in a continuous hot-dip galvanizing line, which comprises detecting and tilting the sink roll in a direction to correct them according to the detected values to correct the meandering of the strip in the sink roll part. In addition, it is characterized by using a gravel roll as a sink roll.

The device of the present invention comprises a device for tiltably supporting the sink roll, a drive device for the sink roll, a control system for driving the sink roll in synchronization with the peripheral speed of the strip roll, and the vicinity of the sink roll. Detects the meandering amount, meandering speed and meandering direction that occur in the strip, and according to these detection values, tilts the sink roll in the direction to correct them and controls to correct the strip meandering in the sink roll part. It is a strip meandering correction device in a continuous hot-dip galvanizing line characterized by having a system, and is characterized by using a gravel roll as a sink roll.

[0011]

[Operation] The present inventors conducted various experiments and studies on strip meandering correction control in the sink roll section using a grooveless sink roll by using an experimental apparatus capable of simulating a plating operation on an actual line. It was as a result,
The grooveless sync is achieved by driving the sync roll peripheral speed (SS) and the strip speed (LS) in the condition of SS ≧ LS and tilting the sync roll in a direction to correct the meandering amount and the meandering direction. It has been found that it is possible to correct the meandering of the strip on the roll portion and to drive the strip at a predetermined position.

On the other hand, when the sync roll is used as a conventional idle roll, the meandering of the strip cannot be corrected, it cannot be controlled, and the sync roll is driven in synchronization with the traveling speed of the strip. However, even if it is only a slight deviation in the shape of the strip, the strip is likely to meander. And so on could be confirmed in this experiment.

The present invention has been completed based on the above findings. The principle of the present invention will be described below. The present invention is
The sync roll is driven in synchronism with the strip speed, and the sync roll is tilted in a direction that corrects these depending on the amount of meandering, the meandering speed and the meandering method that are occurring. It is intended to make a prompt correction and drive the vehicle to a predetermined position.

FIG. 2 schematically shows a method of correcting the meandering of the strip 1 generated in the sink roll 2, for example, when the strip 1 is meandering to the right side (R side), the right tension of the strip 1 In order to correct the meandering by tilting the sink roll 2 to the right so as to become even larger, the tilting amount and tilting speed are controlled according to the meandering amount, the meandering speed and the meandering direction of the strip 1. As a more specific meandering control, even when the strip 1 meanders to the right side (R side), if the direction in which the strip 1 is about to move at this time is the left side (L side), the sync roll depends on the meandering speed. The sink roll 2 is operated in a direction to alleviate the tilt of the right slant 2 (a direction in which it is raised to the right) to control the tilt of the sink roll 2 when the strip returns to the predetermined traveling position. However, if the strip 1 is on the right side without such control and the sink roll 2 is kept on the right side, the strip 1 has passed the predetermined traveling position and the left side (L
Side) meandering and cannot control.

[0015]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the meandering control device of the present invention. In FIG. 1, the strip edge sensor 5 detects the traveling position of the strip 1 and outputs it to the calculator I6. The calculator I6 calculates the meandering amount, the meandering speed and the meandering direction from the detected value of the strip edge sensor 5 and the strip width signal W, and the rotation angle of the sink roll 2 tilting motor 7 (which is necessary to correct the meandering). The amount of rotation corresponding to the tilt angle of the sync 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. Output to the controller I8.

The controller I8 controls the amount of rotation and the 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 moving the sink roll supporting shaft 17 up and down (when the right supporting shaft 17 is lowered, the left supporting shaft 17 is moved). Can be raised).

As described above, the running position of the strip is constantly detected, and the strip is controlled to run at a predetermined running position by using the meandering amount, the meandering speed, the meandering direction, and the tilt amount of the sink roll. On the other hand, the rotation speed of the motor 10 that rotationally drives the sync roll 2 is detected by the encoder 11 and output to the calculator II12. Strip speed L for calculator II12
After calculating the sync roll 2 peripheral speed SS from S and the sync roll 2 rotational speed detected by the encoder 11, these are compared and the sync roll 2 rotational speed at which the sync roll peripheral speed SS becomes the same speed as the strip speed LS is calculated. And the controller II
Output to 13. The controller II13 controls the rotation speed of the motor 10.

It should be noted that although an example in which a gear mechanism is driven by a motor is used as the actuator for tilting the sink roll has been described here, it is also possible to use an electric or pneumatic cylinder other than this. .. Further, as the strip edge sensor, an optical type of light emitting and receiving type, an eddy current type, or a touch roll type (one in which a roll is constantly brought into contact with the strip edge to detect the displacement of the roll), the entire width of the strip or Any method such as capturing a part of the image and processing the image to detect the amount of meandering may be used.

Further, the strip meandering control has been described by the method of moving the sink roll up and down, but a method of tilting the sink roll in a horizontal plane or in a plane inclined at an arbitrary angle as shown in FIG. 3 may be used.

[0020]

The following effects can be obtained by the strip meandering control in the sink roll section to which the present invention is applied. (1) Since it is possible to use a grooveless sink roll, it is possible to manufacture a product with excellent plating quality without groove marks. (2) Since it is possible to use a grooveless sink roll, it is possible to replace the plating equipment and eliminate maintenance costs due to the clogging of the groove that has occurred in the conventional sink roll, and it is possible to reduce costs.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram that schematically shows the meandering control in the sink roll unit in the present invention.

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

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

FIG. 5 is an explanatory diagram of a group of conventional sink roll bodies.

[Explanation of symbols]

 1 strip 2 sink roll 3 plating bath 4 sink roll body groove 5 strip edge sensor 6 calculator I 7 motor 8 controller I 9 encoder 10 motor 11 encoder 12 calculator II 13 controller II 14 transmission 15 intermediate shaft 16 gear 17 Support shaft SS Sync roll peripheral speed LS Strip speed W Strip width L Left side R Right side

Claims (4)

[Claims] 1. The peripheral speed of the sync roll is driven in synchronization with the strip speed, and the meandering amount, meandering speed and meandering method occurring in the strip in the vicinity of the sync roll are detected, and in accordance with these detected values. A method for correcting strip meandering in a continuous hot-dip galvanizing line, which comprises tilting a sink roll in a direction to correct these and correcting strip meandering in the sink roll part. 2. The method for correcting the meandering of a strip in a continuous hot-dip galvanizing line according to claim 1, wherein a gray bless roll is used as the sink roll. 3. A control system that includes a device for tiltably supporting the sink roll, a drive device for the sink roll, and drives the sink roll in synchronization with the peripheral speed of the sink roll and the strip speed. The meandering amount, meandering speed, and meandering direction are detected, and the sink roll is tilted in a direction to correct them according to the detected values.
A strip meandering correction device in a continuous hot-dip galvanizing line, comprising a control system for correcting strip meandering in a sink roll section. 4. The strip meandering correction device in a continuous hot-dip galvanizing line according to claim 3, wherein a gray bless roll is used as the sink roll.