JP2015160959A - Non-contact control device for metal strip and production method for hot-dip galvanized metal strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variance in coating weight of hot-dip metal coating in a metal strip width direction by increasing correction force in the width-direction center where a metal strip warps most.SOLUTION: A non-contact control device for a metal strip includes: electromagnets which are arranged on both surfaces of a metal strip and provided in the width-direction center and at right and left edges of the metal strip; non-contact position sensors which are arranged on both surfaces or one surface of the metal strip and near the electromagnets in the width-direction center and at right and left edges, and which detect the position of the metal strip; and a control device which controls magnetic force of the electromagnets by adjusting currents flowing to the electromagnets to thereby control the vibration and the position of the metal strip. Each of the electromagnets has an electromagnet for vibration control and an electromagnet for position control, and the electromagnets for vibration control are configured in such a way that the electromagnet in width-direction center and the electromagnets at the right and left edges have equal number N1 of turns, and the electromagnets for position control are configure in such a way that the number N2 of turns of the electromagnet in the width-direction center is larger than the number N3 of turns of the electromagnets provided at the right and left edges.

Description

  The present invention relates to a non-contact control device for a metal band and a method for manufacturing a hot-dip metal band by controlling external vibration and warpage of the metal band by applying an external force to the metal band in a non-contact manner by an electromagnet in a hot-dip metal band manufacturing facility. About.

  Conventionally, as a method for continuously plating a metal strip, a continuous molten metal plating method in which the metal strip is immersed in a molten metal and plating is performed on the surface of the metal strip is known. When hot dip galvanizing is applied to the metal strip using this continuous hot metal plating method, the metal strip (thin steel plate) is introduced into the hot dip zinc bath and the metal strip is placed on the sink roll provided in the bath. Wrapping and passing the metal strip through a molten zinc bath in a substantially V-shaped path, the molten zinc adheres to the surface of the metal strip. Then, a wiping gas is sprayed from the gas wiping nozzle onto both surfaces of the metal strip immediately after being drawn out from the molten zinc bath, and the excess molten metal is wiped off to adjust the adhesion amount of the molten galvanizing.

  In such a continuous hot dip plating method, when the metal band has a defective shape such as C warp or ear wave, or the metal band vibrates, the distance between the gas wiping nozzle and the metal band is the longitudinal direction of the metal band. And it changes to the width direction and the adhesion amount of hot dip galvanization cannot be controlled appropriately.

  In response to such a problem, a technique has been developed to control warpage and vibration of a metal band by applying an external force to the metal band in a non-contact manner.

  Patent Document 1 discloses that an electromagnet that controls the position and vibration of both edges of a metal band edge is moved in the width direction of the metal band according to the width of the metal band.

  In Patent Document 2, there are two systems: a vibration control coil (electromagnet) for controlling the vibration of the metal band and a position correction coil (electromagnet) for controlling the position of the metal band, which has more turns than the vibration control coil. It is disclosed to provide the coil.

Japanese Patent Laid-Open No. 2001-150015 JP 2011-183438 A

  In the metal band, warpage becomes large at the center in the width direction, and therefore it is necessary to increase the correction force at the center in the width direction of the metal band. However, Patent Documents 1 and 2 do not disclose any device for increasing the correction force at the center in the width direction of the metal band, and cannot sufficiently correct the warp of the metal band.

The present invention has the following features in order to solve the above-described problems.
[1] An electromagnet disposed on both surfaces of the metal band and provided at the center in the width direction and the left and right edges of the metal band;
A non-contact position sensor that is disposed in the vicinity of the electromagnet at the center in the width direction and the left and right edges on both sides or one side of the metal band, and detects the position of the metal band;
A controller for controlling the magnetic force of the electromagnet by adjusting the current flowing through the electromagnet, and controlling the vibration and position of the metal strip, and
The electromagnet includes a vibration control electromagnet and a position control electromagnet,
The vibration control electromagnet has the same number of turns N1 of the electromagnet at the center in the width direction and the left and right edges,
The position control electromagnet is a non-contact control device for a metal band in which the number of turns N2 of the electromagnet at the center in the width direction is larger than the number of turns N3 of the electromagnet provided at the left and right edges.
[2] The number of turns N2 of the electromagnet in the center in the width direction of the electromagnet for position control and the number of turns N3 of the electromagnet provided on the left and right edges are larger than the number N1 of turns of the electromagnet for vibration control. [1] Non-contact control device for metal strips as described in 1.
[3] The number of turns N1 of the electromagnet for vibration control is less than half of the number of turns N2 of the electromagnet at the center in the width direction of the electromagnet for position control and the number of turns N3 of the electromagnet provided at the left and right edges. [2] A non-contact control device for a metal strip according to [2].
[4] Electromagnets provided on the left and right edges of the vibration control electromagnet and the position control electromagnet move following the positions of the left and right edges of the metal strip, among [1] to [3] The non-contact control apparatus of the metal strip in any one.
[5] A baffle plate that prevents collision of wiping gases ejected from gas wiping nozzles disposed opposite to both surfaces of the metal strip on both sides in the width direction of the metal strip,
The baffle plate moves following the positions of the left and right edges of the metal strip,
The non-contact control device for a metal strip according to [4], wherein the electromagnets provided on the left and right edges are installed on the baffle plate.
[6] A method for producing a hot dipped metal strip using the non-contact control device for a metal strip according to any one of [1] to [5].

  According to the present invention, the center of the width direction in which the warp of the metal strip is the largest by increasing the number of turns N2 of the center electromagnet of the position control electromagnet to the number of turns N3 of the electromagnet provided on the left and right edges. The correction force in can be increased. Thereby, the precision of the position control of a metal strip can be improved and the dispersion | variation in the adhesion amount of the molten metal plating in a metal strip width direction can be reduced.

It is a figure which shows the non-contact control apparatus of the metal strip which concerns on embodiment of this invention. It is a figure which shows the structure of the electromagnet for vibration control of the non-contact control apparatus of the metal strip which concerns on embodiment of this invention, and the electromagnet for position control. It is a figure which shows operation | movement of the electromagnet for position control of the non-contact control apparatus of the metal strip which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a non-contact control device for a metal strip according to an embodiment of the present invention. In FIG. 1, the metal strip 1 (steel strip) coming out of the molten metal plating bath moves on a pass line indicated by a one-dot chain line from the lower side to the upper side of the drawing. A gas wiping nozzle 2 is provided on the outlet side of the molten metal plating bath, and a wiping gas is sprayed from both sides of the metal band 1 to wipe away the excessive molten metal adhering to the metal band 1, and the amount of molten metal deposited Is adjusted.

  The metal band non-contact control device has a non-contact position sensor 3, an electromagnet 4, and a control device 5. The gas wiping nozzle 2, the non-contact position sensor 3, and the electromagnet 4 are respectively provided on both surfaces of the metal band 1 and are disposed to face each other with the metal band 1 interposed therebetween. The gas wiping nozzle 2, the non-contact position sensor 3, and the electromagnet 4 are sequentially arranged in the moving direction of the metal strip 1.

  The non-contact position sensor 3 detects the distance from the metal strip 1 in a non-contact manner. As will be described later, the non-contact position sensor 3 is provided at each of the center in the width direction and the left and right edges of the metal strip 1. The non-contact position sensor 3 detects the position of the metal strip 1 in the thickness direction. The position information of the metal band 1 is sent to the control device 5. The position of the non-contact position sensor 3 is not limited to the arrangement shown in FIG. The position of the non-contact position sensor 3 should just be provided in the longitudinal direction and the width direction of the metal strip 1 of the electromagnet 4. The non-contact position sensor 3 may be configured to be provided only on one side of the metal band 1.

  The electromagnet 4 controls the vibration and warpage of the metal band 1 by applying an external force to the metal band in a non-contact manner by magnetic force. The electromagnet 4 includes a vibration control electromagnet 41 that controls the vibration of the metal strip 1 and a position control electromagnet 42 that controls the position of the metal strip 1 in the thickness direction. The vibration control electromagnet 41 and the position control electromagnet 42 are sequentially arranged along the moving direction of the metal strip 1.

  Of the electromagnet 41 for vibration control and the electromagnet 42 for position control, the electromagnet provided at the left and right edges is preferably configured to move following the positions of the left and right edges of the metal strip 1. Thereby, the vibration and the curvature of the left and right edges of the metal band 1 can be corrected with high accuracy. Note that the positions of the left and right edges of the metal strip 1 may be detected by the non-contact position sensor 3 or may be detected by another sensor.

  The vibration control electromagnet 41 and the position control electromagnet 42 may be installed on the baffle plate. The baffle plate is disposed opposite to both ends of the metal strip 1 in order to prevent generation of turbulent flow of wiping gas due to collision of wiping gases ejected from the gas wiping nozzles 2 disposed opposite to both surfaces of the metal strip 1. The gas wiping nozzles 2 are arranged. The baffle plate moves following the positions of the left and right edges in the width direction of the metal strip 1. Therefore, if the vibration control electromagnet 41 and the position control electromagnet 42 are installed on the baffle plate, a new drive mechanism for the vibration control electromagnet 41 and the position control electromagnet 42 is not provided, and the left and right sides of the metal band 1 are arranged. It is possible to follow the edge.

  The control device 5 controls the magnetic force of the electromagnet 4 based on the position in the thickness direction of the metal strip 1 detected by the non-contact position sensor 3. The control device 5 adjusts the current flowing through the electromagnet 4 and controls the magnetic force of the electromagnet 4 to reduce the vibration of the metal band 1 and correct the warp of the metal band 1. By making the distance between the metal strip 1 uniform in the longitudinal direction and the width direction of the metal strip 1, the amount of plating attached to both surfaces of the metal strip 1 is controlled uniformly.

  FIG. 2 is a diagram showing a configuration of a vibration control electromagnet and a position control electromagnet of the non-contact control device for a metal strip according to the embodiment of the present invention.

  FIG. 2 is a view of the vibration control electromagnet 41 and the position control electromagnet 42 provided on one side of the metal strip 1 from the metal strip 1. The vibration control electromagnet 41 and the position control electromagnet 42 provided on the other surface of the metal strip 1 also have the same configuration as FIG.

  The vibration control electromagnet 41 and the position control electromagnet 42 are provided at the center in the width direction of the metal strip 1 and at the left and right edges, respectively.

  In the electromagnet 41 for vibration control, the number of turns of the electromagnet at the center in the width direction and the left and right edges of the metal strip 1 is N1 and the same.

  On the other hand, in the position control electromagnet 42, the winding number N2 of the electromagnet 42a at the center in the width direction of the metal band 1 is larger than the winding number N3 of the electromagnet 42b at the left and right edges. Specifically, the number of turns N2 of the electromagnet 42a at the center in the width direction of the metal band 1 is preferably about 1.5 to 2 times the number of turns N3 of the electromagnet 42b at the left and right edges. By making the winding number N2 1.5 times or more of the winding number N3, the shape of the steel sheet can be corrected efficiently. Moreover, the response of shape correction can be improved by setting the number of turns N2 to be equal to or less than twice the number of turns N3.

  Further, the number of turns N3 of the electromagnets 42b at the left and right edges of the position control electromagnet 42 is larger than the number of turns N1 of the vibration control electromagnet 41. That is, the winding numbers N1 to N3 satisfy the relationship N1 <N3 <N2. The number of turns N1 of the vibration control electromagnet 41 is preferably less than half the number N2 of turns of the center electromagnet 42a and the number of turns N3 of the left and right electromagnets 42b of the position control electromagnet 42. The responsiveness of vibration control can be improved by setting the number of turns N1 to half or less of the number of turns N2 and N3.

  Non-contact position sensors 3 are provided in the immediate vicinity of the center in the width direction and the upstream side of the vibration control electromagnet 41 at the left and right edges, respectively. By disposing the non-contact position sensor 3 immediately before each vibration control electromagnet 41, it is possible to improve the accuracy of vibration control by the vibration control electromagnet 41 and position control by the position control electromagnet 42.

  FIG. 3 is a diagram showing the operation of the position control electromagnet of the non-contact control device for a metal strip according to the embodiment of the present invention. FIG. 3 is a view of the position control electromagnets 42 a and 42 b as viewed from above, and the left-right direction on the paper surface corresponds to the width direction of the metal strip 1. In FIG. 3, a center line C (dashed line) indicates an intermediate position between the position control electromagnets 42 a and 42 b arranged opposite to each other with the metal band 1 interposed therebetween.

  The dotted line shows the metal band 1 in a state before shape correction by the position control electromagnets 42a and 42b. The metal band 1 indicated by the dotted line is in a state where the center in the width direction is convex upward in the drawing, and so-called C warpage occurs.

  As described above, when the metal band 1 is warped, the control device 5 controls the magnetic force of the central position control electromagnet 42a and the left and right edge position control electromagnets 42b to thereby control the metal band 1. An external force is applied to each of the center and left and right edges. At this time, the distance from the center line C of the central portion of the metal band 1 is larger than the distance from the center line C of the left and right edges of the metal band 1. Therefore, it is necessary to make the magnetic force of the position control electromagnet 42a at the center of the metal band 1 larger than the magnetic force of the left and right edge position control electromagnets 42b. Specifically, it is necessary to apply a large external force toward the lower side (arrow direction) to the center in the width direction of the metal band 1 and a small external force toward the upper side (arrow direction) to the left and right edges of the metal band 1. is there.

  In the present embodiment, the number of turns N2 of the position control electromagnet 42a at the center in the width direction of the metal strip 1 that requires a larger external force is made larger than the number of turns N3 of the position control electromagnet 42b at the left and right edges, A large magnetic force can be generated at the center in the width direction.

  By applying such an external force, the metal band 1 becomes substantially linear as shown by a solid line, and the metal band 1 is corrected to the center line C over the entire width direction of the metal band 1. As a result, the distance from the gas wiping nozzle 2 is uniform over the entire width direction of the metal strip 1, and variations in the amount of plating can be reduced.

  As described above, in the metal band non-contact control device according to the embodiment, the number N2 of turns of the position control electromagnet 42a at the center in the width direction is determined by the warp of the metal band 1 and the positions of the left and right edges of the metal band 1 The number of turns N3 of the control electromagnet 42b is set larger. Thereby, the magnetic force of the position control electromagnet 42a at the center in the width direction where the greatest correction force is required can be increased, and an appropriate external force can be applied according to the position of the metal strip 1. Thereby, the distance with the gas wiping nozzle 2 becomes uniform over the width direction of the metal strip 1, and the variation in the amount of plating can be reduced.

  In the present embodiment, the vibration control electromagnet 41 is disposed in front of the position control electromagnet 42a, so that the vibration is reduced by the vibration control electromagnet 41 and then the shape correction is performed by the position control electromagnet 42a. Therefore, the accuracy of shape correction by the position control electromagnet 42a can be improved.

  In the above description, the non-contact control device for the metal band has been described. However, the present invention may be implemented as a method for manufacturing the metal band using the non-contact control device for the metal band as described above.

DESCRIPTION OF SYMBOLS 1 Metal strip 2 Gas wiping nozzle 3 Non-contact position sensor 4 Electromagnet 41 Electromagnet for vibration control 42 Electromagnet for position control 5 Controller N1 Number of windings of electromagnet for vibration control N2 Number of windings of electromagnet in the center of electromagnet for position control N3 Position control Number of electromagnets on the left and right edges of the electromagnet C

Claims (6)

An electromagnet arranged on both sides of the metal strip, provided at the center in the width direction and the left and right edges of the metal strip,
A non-contact position sensor that is disposed in the vicinity of the electromagnet at the center in the width direction and the left and right edges on both sides or one side of the metal band, and detects the position of the metal band;
A controller for controlling the magnetic force of the electromagnet by adjusting the current flowing through the electromagnet, and controlling the vibration and position of the metal strip, and
The electromagnet includes a vibration control electromagnet and a position control electromagnet,
The vibration control electromagnet has the same number of turns N1 of the electromagnet at the center in the width direction and the left and right edges,
The position control electromagnet is a non-contact control device for a metal band in which the number of turns N2 of the electromagnet at the center in the width direction is larger than the number of turns N3 of the electromagnet provided at the left and right edges.   The winding number N2 of the electromagnet in the center in the width direction of the electromagnet for position control and the winding number N3 of the electromagnet provided at the left and right edges are larger than the winding number N1 of the electromagnet for vibration control. Non-contact control device for metal strip.   The number N1 of windings of the electromagnet for vibration control is less than half of the number N2 of windings of the electromagnet at the center in the width direction of the electromagnet for position control and the number of windings N3 of the electromagnet provided at the left and right edges. Non-contact control device of the metal strip described.   The electromagnet provided on the left and right edges of the vibration control electromagnet and the position control electromagnet moves following the positions of the left and right edges of the metal strip, according to any one of claims 1 to 3. Non-contact control device for metal strip. On both sides in the width direction of the metal strip, there is a baffle plate that prevents collision between wiping gases ejected from gas wiping nozzles arranged opposite to both surfaces of the metal strip,
The baffle plate moves following the positions of the left and right edges of the metal strip,
The non-contact control apparatus of the metal strip of Claim 4 with which the electromagnet provided in the said right and left edge is installed in the said baffle plate.   A method for producing a hot dipped metal strip using the non-contact control device for a metal strip according to any one of claims 1 to 5.

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