PLATE CROSSBOW CORRECTION DEVICE AND PLATE CROSSBOW CORRECTION METHOD

Abstract

Each of the moving blocks of the plate crossbow correction device includes distance sensors and electromagnets, and plate crossbow is corrected by adjusting electromagnetic force by the electromagnets in accordance with distances to strips. The moving blocks are movable in the horizontal direction and ratios of moving distances of the moving blocks are adjusted to be constant when seen from a central position.

Claims

1. A plate crossbow correction device including: a correction mechanism on a front surface side disposed on a front surface side of a conveyed steel plate which adjusts electromagnetic force applied to the steel plate in accordance with a distance to the steel plate and corrects crossbow of the steel plate, and a correction mechanism on a back surface side disposed on a back surface side of the conveyed steel plate which adjusts electromagnetic force applied to the steel plate in accordance with a distance to the steel plate and corrects crossbow of the steel plate, wherein the correction mechanism on the front surface side and the correction mechanism on the back surface side respectively comprise a plurality of moving blocks comprised with distance sensors detecting a distance to the steel plate and electromagnets applying electromagnetic force to the steel plate, a guide structure supporting the plurality of blocks to be movable along a plate width direction of the steel plate, and a moving structure moving a moving block close to an end portion of the steel plate from among the plurality of moving blocks along the guide structure and moving the remaining blocks along the guide structure following the moving block close to the end portion of the steel plate.

2. The plate crossbow correction device according to claim 1, wherein the moving mechanism includes a servomotor and a rack and pinion mechanism transmitting driving force of the servomotor to the plurality of moving blocks and moving the plurality of moving blocks.

3. The plate crossbow correction device according to claim 2, wherein the rack and pinion mechanism is arranged in that the gear ratio is determined such that moving distances each of the moving blocks move when seen from a central position of the plate crossbow correction device become a distance which is in accordance with a preliminarily determined stroke ratio.

4. The plate crossbow correction device according to claim 1, further comprising a plate edge sensor detecting plate width edge positions which are positions at ends in the plate width direction of the steel plate, and a control unit controlling moving operations of the moving mechanism such that a moving block close to an end portion of the steel plates from among the plurality of moving blocks opposes the plate width edge position.

5. A plate crossbow correction device further including an overall moving mechanism on the front surface side moving the correction mechanism on the front surface side according to claim 1 along the plate width direction of the steel plate, and an overall moving mechanism on the back surface side moving the correction mechanism on the back surface side according to claim 1 along the plate width direction of the steel plate.

6. A plate crossbow correction method by a plate crossbow correction device, wherein a correction mechanism on a front surface side disposed on a front surface side of a conveyed steel plate which adjusts electromagnetic force applied to the steel plate in accordance with a distance to the steel plate and corrects crossbow of the steel plate, and a correction mechanism on a back surface side disposed on a back surface side of the conveyed steel plate which adjusts electromagnetic force applied to the steel plate in accordance with a distance to the steel plate and corrects crossbow of the steel plate, respectively include a plurality of moving blocks comprised with distance sensors detecting a distance to the steel plate and electromagnets applying electromagnetic force to the steel plate, and a guide structure supporting the plurality of blocks to be movable along a plate width direction of the steel plate, wherein a moving block close to an end portion of the steel plate from among the plurality of moving blocks is moved along the guide structure and the remaining moving blocks are moved along the guide structure following movements of the moving block close to the end portion of the steel plate.

7. The plate crossbow correction method according to claim 6, wherein the plurality of moving blocks are moved such that moving distances each of the moving blocks move when seen from a central position of the plate crossbow correction device become a distance which is in accordance with a preliminarily determined stroke ratio.

8. The plate crossbow correction method according to claim 6, wherein plate width edge positions which are positions at ends in the plate width direction of the steel plate are detected, and a moving block close to an end portion of the steel plate from among the plurality of moving blocks is moved to a position opposing the plate width edge position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG. 1 is a front view showing a hot-dip galvanizing line comprising the plate crossbow correction device according to the first embodiment of the present invention.

[0064] FIG. 2 is a side view showing the hot-dip galvanizing line comprising the plate crossbow correction device according to the first embodiment of the present invention.

[0065] FIG. 3 is a front view when a correction mechanism on a front surface side in a widened state is seen from the strip side.

[0066] FIG. 4 is a front view when the correction mechanism on the front surface side in a narrowed state is seen from the strip side.

[0067] FIG. 5 is a sectional view including an A-A section of FIG. 3.

[0068] FIG. 6 is a sectional view including a B-B section of FIG. 3.

[0069] FIG. 7A is a plan view showing a moving mechanism in a widened state.

[0070] FIG. 7B is a plan view showing a moving mechanism in a widened state.

[0071] FIG. 8 A is a plan view showing the moving mechanism in a narrowed state.

[0072] FIG. 8 B is a plan view showing the moving mechanism in a narrowed state.

[0073] FIG. 9 is a characteristic diagram showing a crossbowed state of a strip at a position at which a distance sensor is disposed in the first embodiment.

[0074] FIG. 10 is a characteristic diagram showing a crossbowed state of a strip at a position at which a wiping nozzle is disposed in the first embodiment.

[0075] FIG. 11 is a characteristic diagram showing a crossbowed state of a strip after crossbowing correction at the position at which the distance sensor is disposed in a plate crossbow correction device comprising five pairs of electromagnets.

[0076] FIG. 12 is a characteristic diagram showing a crossbowed state of a strip after crossbowing correction at the position at which the wiping nozzle is disposed in the plate crossbow correction device comprising five pairs of electromagnets.

[0077] FIG. 13 is a characteristic diagram showing a relationship between numbers of pairs of electromagnets and plate crossbow at the position at which the wiping nozzle is disposed.

[0078] FIG. 14 is a plan view showing the plate crossbow correction device according to the second embodiment of the present invention.

[0079] FIG. 15 is a front view when the plate crossbow correction device according to the second embodiment of the present invention is seen from the strip side.

[0080] FIG. 16 is a front view showing a hot-dip galvanizing line comprising the plate crossbow correction device of the prior art.

[0081] FIG. 17 is a side view showing the hot-dip galvanizing line comprising the plate crossbow correction device of the prior art.

[0082] FIG. 18 is a characteristic diagram showing a crossbowed state of a strip at a position at which a distance sensor is disposed according to the prior art.

[0083] FIG. 19 is a characteristic diagram showing a crossbowed state of a strip at a position at which a wiping nozzle is disposed according to the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0084] Embodiments of the present invention will now be explained in details based on examples thereof.

First Embodiment

[0085] A hot-dip galvanizing line 10a comprising a plate crossbow correction device 100 according to the first embodiment of the present invention will be explained with reference to FIG. 1 which is a front view and FIG. 2 which is a side view.

[0086] In the hot-dip galvanizing line 10a, strips 2 successively infiltrated into molten metal 1 are wound around a sink roll 3 and the running direction is changed into an upward direction, similarly to the hot-dip galvanizing line 10 shown in FIG. 16 and FIG. 17. After making in-bath rolls 4a 4b contact both surfaces of the strips 2, the strips 2 are pulled out from the molten metal 1, and air is sprayed from a wiping nozzle 5 towards both surfaces of the strips 2 to remove excess molten metal. A plate crossbow correction device 100 according to the present embodiment is disposed upward of the wiping nozzle 5, and the strips 2 run upward upon passing the plate crossbow correction device 100.

[0087] Explaining the outline of the plate crossbow correction device 100, the plate crossbow correction device 100 includes a correction mechanism 100F on the front surface side disposed to be apart from the front surface of a strip 2 and a correction mechanism 100B on the back surface side disposed to be apart from the back surface of the strip 2.

[0088] The correction mechanism 100F on the front surface side comprises a plurality of (in this example, four) electromagnets M aligned in the plate width direction and a plurality of (in this example, four) distance sensors S aligned in the plate width direction. Similarly to the correction mechanism 100F on the front surface side, the correction mechanism 100B on the back surface side also comprises a plurality of (in this example, four) electromagnets M aligned in the plate width direction and a plurality of (in this example, four) distance sensors S aligned in the plate width direction. Moreover, the electromagnets M provided in the correction mechanism 100F on the front surface side and the electromagnets M provided in the correction mechanism 100B on the back surface side are respectively disposed to oppose each other with the strips 2 being interposed between.

[0089] Namely, the plate crossbow correction device 100 comprises four pairs of electromagnets M. While details will be explained later, the four pairs of electromagnets M are arranged to move in the plate width direction (horizontal direction) of the strips 2 in accordance with meanderings or changes in plate widths of the strips 2 in order to suitably correct crossbowing of the strips 2.

[0090] In this respect, when the distance sensors S on the front surface side and the distance sensors S on the back surface side perform measurement at identical positions in the plate width direction, it is also possible to omit either ones on one side of the distance sensors S on the front surface side and the distance sensors S on the back surface side.

[0091] A plate edge sensor 20 is disposed at an upward position of the plate crossbow correction device 100. The plate edge sensor 20 detects plate edge positions which are positions on one end (right end in the example of FIG. 1) in the plate width direction of the strips 2.

[0092] As it will be described later, a control device 30 controls positions in the plate width direction of the four pairs of electromagnets M of the plate crossbow correction device 100 in accordance with plate width edge positions detected by the plate edge sensor 20.

[0093] Next, details of the plate crossbow correction device 100 will be explained.

[0094] FIG. 3 is a front view of the correction mechanism 100F on the front side in a widened state seen from the strip side, FIG. 4 is a front view of the correction mechanism 100F on the front side in a narrowed state seen from the strip side, FIG. 5 is a sectional view including an A-A section of FIG. 3, and FIG. 6 is a sectional view including a B-B section of FIG. 3. In this respect, for easy understanding, components which are not illustrated in FIG. 3 are shown in FIG. 5 and FIG. 6.

[0095] In this respect, since machine configurations of the correction mechanism 100F on the front side and the correction mechanism 100B on the back side are identical, explanations will be made of the detailed configuration of the correction mechanism 100F on the front side only while explanations of the detailed configuration of the correction mechanism 100B on the back side will be omitted.

[0096] As shown in FIG. 3 to FIG. 6, a frame 102 extending in the plate width direction (horizontal direction) of the strips 2 is fixedly installed at a support beam 101.

[0097] The frame 102 is provided with four moving blocks 110-1, 110-2, 110-3 and 110-4 aligned in the horizontal direction. While details will be explained later, the moving blocks 110-1 to 110-4 are provided to be movable in the horizontal direction along the frame 102. In this respect, reference numeral 110 is used when the four moving blocks 110-1 to 110-4 are to be collectively referred to.

[0098] Each moving block 110 is provided with an electromagnet M and a distance sensor S of eddy current type. Namely, the electromagnet M is provided on a lower side of a support pole 111 of the moving block 110 and the distance sensor S is provided on an upper side of the support pole 111 (see FIG. 6). Namely, the distance sensor S is disposed at an upward position of the electromagnet M.

[0099] A lower support plate 112 is fixed to an upper end portion of the support pole 111 and an upper support plate 113 is disposed at an upward position of the lower support plate 112. The upper support plate 113 is attached to the lower support plate 112 via gears (pinions or the like) to be described later.

[0100] A linear rail 103 extending in the horizontal direction is provided on a lower surface of the frame 102. A linear slider 104 is attached on an upper surface of the upper support plate 113 of each moving block 110. The linear slider 104 of the moving blocks 110 engages with the linear rail 103 in a freely sliding manner, and the linear rail 103 and the linear sliders 104 constitute a linear guide (guide structure).

[0101] The moving blocks 110 are made movable in the horizontal direction by the thus arranged linear guide (guide structure).

[0102] In this respect, the wiping nozzle 5 is attached to the frame 102 via a support body 50 and is disposed at a downward position of the moving blocks 110.

[0103] Next, a moving mechanism 200 for moving the moving blocks 110 in the horizontal direction will be explained.

[0104] The moving mechanism 200 is arranged to transmit driving force of a servomotor to the moving blocks 110 using a rack and pinion mechanism for moving the moving blocks 110. Moreover, the rack and pinion mechanism is comprised of gear elements in mesh with other gear elements on an upper plane and gear elements in mesh with other gear elements on a lower plane with respect to the vertical direction.

[0105] In the following explanations, gear elements in mesh with other gear elements on the upper plane are marked with reference numerals which are numbers added with while gear elements in mesh with other gear elements on the lower plane are marked with reference numerals which are numbers added with .

[0106] FIG. 7A and FIG. 7B are plan views showing the moving mechanism 200 provided in the correction mechanism 100F of the plate crossbow correction device 100 in a widened state, and FIG. 8A and FIG. 8B are plan views showing the moving mechanism 200 provided in the correction mechanism 100F of the plate crossbow correction device 100 in a narrowed state.

[0107] Further, in FIG. 7A and FIG. 8A, gear elements in mesh with other gear elements on the upper plane are shown by solid lines while gear elements in mesh with other gear elements on the lower plane are shown by dotted lines. In FIG. 7B and FIG. 8B, gear elements in mesh with other gear elements on the lower plane are shown by solid lines while gear elements in mesh with other gear elements on the upper plane are shown by dotted lines.

[0108] A driving source unit 205 is attached to the frame 102 at a central portion in the horizontal direction of the correction mechanism 100F of the plate crossbow correction device 100. The driving source unit 205 comprises a servomotor 206, and a drive gear 201 is provided at a rotating shaft of the servomotor 206. The driving source unit 205 is provided with a pinion gear 202 and a pinion gear 203 which mesh with the drive gear 201.

[0109] The moving block 110-1 is provided with a pinion gear 211, an idler gear 212 which is in mesh with the pinion gear 211 and a speed-increasing pinion gear 213 which is a two-stage gear formed of a small-diameter gear and a large-diameter gear. The idler gear 212 is in mesh with the small-diameter gear of the speed-increasing pinion gear 213.

[0110] Lower end sides of rotating shafts of these gears 211, 212 and 213 are supported by the lower support plate 112 through bearings and upper end sides of the rotating shafts are supported by the upper support plate 113 through bearings.

[0111] The moving block 110-1 is provided with a movable rack 214 projecting to the driving source unit 205 side, and the movable rack 214 is in mesh with the pinion gear 202. Moreover, the movable rack 214 is supported at the frame 102 in a movable manner by means of a linear guide for movable racks.

[0112] Moreover, a fixed rack 215 is fixed to the frame 102 proximate of the moving block 110-1. The fixed rack 215 is in mesh with the pinion gear 211.

[0113] The moving block 110-2 is provided with a movable rack 221 projecting to the moving block 110-1 side and the movable rack 221 is in mesh with the large-diameter gear of the pinion gear 213. Further, the movable rack 221 is supported at the frame 102 in a movable manner by means of the linear guide for movable racks.

[0114] The moving block 110-3 is provided with a pinion gear 231, an idler gear 232 which is in mesh with the pinion gear 231 and a speed-increasing pinion gear 233 which is a two-stage gear formed of a small-diameter gear and a large-diameter gear. The idler gear 232 is in mesh with the small-diameter gear of the speed-increasing pinion gear 233.

[0115] Lower end sides of rotating shafts of these gears 231, 232 and 233 are supported by the lower support plate 112 through bearings and upper end sides of the rotating shafts are supported by the upper support plate 113 through bearings.

[0116] The moving block 110-3 is provided with a movable rack 234 projecting to the driving source unit 205 side, and the movable rack 234 is in mesh with the pinion gear 203. Moreover, the movable rack 234 is supported at the frame 102 in a movable manner by means of the linear guide for movable racks.

[0117] Moreover, a fixed rack 235 is fixed to the frame 102 proximate of the moving block 110-3. The fixed rack 235 is in mesh with the pinion gear 231.

[0118] The moving block 110-4 is provided with a movable rack 241 projecting to the moving block 110-3 side and the movable rack 241 is in mesh with the large-diameter gear of the pinion gear 233. Moreover, the movable rack 241 is supported at the frame 102 in a movable manner by means of the linear guide for movable racks.

[0119] In the moving mechanism 200, the diameter of the pinion gears 202, 203, 211 and 231 is D1, and in the speed-increasing pinion gears 213, 233, the diameter of the large-diameter gears is D1 while the diameter of the small-diameter gears is D2. Namely, the gear ratio of the rack and pinion mechanism of the moving mechanism 200 is determined by the diameter D1 and the diameter D2.

[0120] Next, operations of moving the moving blocks 110 in the horizontal direction by driving the moving mechanism 200 will be explained.

[0121] When the driving gear 201 is rotated leftward by the servomotor 206 of the driving source unit 205 in the widened state as shown in FIG. 7A and FIG. 7B , the pinion gear 202 is rotated rightward and pulls the movable rack 214 to the driving source unit 205 side. With this arrangement, the moving block 110-1 moves to the left.

[0122] When the moving block 110-1 moves to the left, the pinion gear 211 a in mesh with the fixed rack 215 rotates leftward, the idler gear 212 rotates rightward and the speed-increasing pinion gear 213 rotates leftward. The leftward rotation of the speed-increasing pinion gear 213 pulls the movable rack 221 to the moving block 110-1 side. With this arrangement, the moving block 110-2 moves to the left.

[0123] Further, when the driving gear 201 is rotated leftward by the servomotor 206 of the driving source unit 205 in the widened state as shown in FIG. 7A and FIG. 7B , the pinion gear 203 is rotated rightward and pulls the movable rack 234 to the driving source unit 205 side. With this arrangement, the moving block 110-3 moves to the right.

[0124] When the moving block 110-3 moves to the right, the pinion gear 231 in mesh with the fixed rack 235 rotates leftward, the idler gear 232 rotates rightward and the speed-increasing pinion gear 233 rotates leftward. The leftward rotation of the speed-increasing pinion gear 233 pulls the movable rack 241 to the moving block 110-3 side. With this arrangement, the moving block 110-4 moves to the right.

[0125] In this manner, with the moving blocks 110-1, 110-2 moving to the left and the moving blocks 110-3, 110-4 moving to the right, the narrowed state as shown in FIG. 8A and FIG. 8B is achieved.

[0126] When the driving gear 201 is rotated rightward by the servomotor 206 of the driving source unit 205 in the narrowed state as shown in FIG. 8A and FIG. 8B , the gear elements move in reverse directions to make the moving blocks 110-1, 110-2 move to the right and the moving blocks 110-3, 110-4 move to the left to achieve the widened state as shown in FIG. 7A and FIG. 7B.

[0127] With respect to the plate width direction (horizontal direction) of the strips, in the widened state of FIG. 3, when the distance from the central position CL of the plate crossbow correction device 100 to the moved position of the moving block 110-1 is defined as L12 and the distance from the central position CL to the moved position of the moving block 110-2 is defined as L22, and in the narrowed state of FIG. 4, when the distance from the central position CL to the moved position of the moving block 110-1 is defined as L11 and the distance from the central position CL to the moved position of the moving block 110-2 is defined as L21, the stroke ratio of the moving block 110-1 and the moving block 110-2 can be expressed by the following equation (1).

Stroke ratio=1+(D1/D2)=(L22L21)/(L12L11) (1)

[0128] Similarly, the stroke ratio of the moving block 110-3 and the moving block 110-4 can also be expressed by the equation (1).

[0129] Ultimately, the ratio of the moving distance of the moving blocks 110-2, 110-4 with respect to the moving distance of the moving blocks 110-1, 110-3 is constant (a preliminarily determined constant ratio).

[0130] Namely, the gear ratio of the rack and pinion mechanism of the moving mechanism 200 is determined such that the moving distances of the moving blocks 110-1, 110-2, 110-3 and 110-4, when seen from a central position of the plate crossbow correction device, become a distance which is in correspondence with a preliminarily determined stroke ratio.

[0131] In this respect, in FIG. 3, W indicates a widened strip width and in FIG. 4, W indicates a narrowed strip width.

[0132] A plate width edge position which is a position of one end in the plate width direction of the strip 2 detected by the plate edge sensor 20 is input to the control device 30.

[0133] In that case, the control device 30 controls the servomotor 206 to move the moving blocks 110-4 of the correction mechanisms 100F, 100B such that from among the plate crossbow correction device 100, a pair of electromagnets at which one end side in the plate width direction of the strip 2 is located, more particularly, an electromagnet M provided in the moving block 110-4 which is a moving block close to an end portion of the steel plate (strip 2) from among the moving blocks 110 of the correction mechanism 100F and an electromagnet M provided in the moving block 110-4 which is a moving block close to an end portion of the steel plate (strip 2) from among the moving blocks 110 of the correction mechanism 100B, opposes the one end portion of the strip 2.

[0134] Accompanying movements of the moving blocks 110-4, the other moving blocks 110-1, 110-2 and 110-3 are also moved while maintaining the relationship of the stroke indicated by the equation (1).

[0135] Simultaneously, the control device 30 controls a current value supplied to the electromagnets M such that the distances detected by the distance sensors S become a set distance to thereby adjust the electromagnetic force of the electromagnets M applied to the strip 2. With this arrangement, crossbow of the strips 2 is correct in a contactless manner and vibration of the strips 2 is suppressed.

[0136] Therefore, even when the strips 2 meander or their plate width changes, a pair of electromagnets M on one end side of the plate crossbow correction mechanism 100 and a pair of electromagnets M on the other end side correctly oppose the one end portion and the other end portion of the strip 2.

[0137] FIG. 9 shows a crossbowed state of the strip 2 at a position at which the distance sensor S of the plate crossbow correction device 100 is disposed, wherein the horizontal axis shows the plate width direction position while the vertical axis shows the plate shape (amount of crossbow). The solid line in FIG. 9 shows a crossbowed state of a strip 2 after crossbow correction and the dotted line in FIG. 9 shows a crossbowed state of a strip 2 when no crossbow correction has been performed.

[0138] FIG. 10 shows a crossbowed state of the strip 2 at a position at which the wiping nozzle 5 of the plate crossbow correction device 100 is disposed, wherein the horizontal axis shows the plate width direction position while the vertical axis shows the plate shape (amount of crossbow). The solid line in FIG. 10 shows a crossbowed state of a strip 2 after crossbow correction and the dotted line in FIG. 10 shows a crossbowed state of a strip 2 when no crossbow correction has been performed.

[0139] As shown by the solid lines in FIG. 9 and FIG. 10, when performing plate crossbow correction using electromagnets M in the plate crossbow correction device 100 according to the first embodiment, at least a pair of electromagnets M on one end side will correctly oppose an end portion of the strip 2 so that crossbow at both side portions of the strip 2 can be suppressed.

[0140] Further, since the moving positions of the moving blocks move while maintaining the relationship indicated by the equation (1) at the time the moving blocks 110 move, the disposing positions of the electromagnets M of the moving blocks 110 will be suitable, and plate crossbow of the strip 2 can be reliably suppressed also at positions other than both end portions of the strip 2.

[0141] In the above first embodiment, while the plate crossbow correction device 100 is provided with four pairs of electromagnets M, it might also be provided with five pairs of electromagnets M and also six or more pairs of electromagnets M.

[0142] When the number of pairs of electromagnets M is an odd number, a configuration is employed in which electromagnets M at a central position (a block provided with electromagnets) are not moved.

[0143] FIG. 11 shows a crossbowed state of a strip at the time of crossbow correction at a position at which a distance sensor is disposed in the plate crossbow correction device provided with five pair of electromagnets.

[0144] FIG. 12 shows a crossbowed state of a strip at the time of crossbow correction at a position at which the wiping nozzle is disposed in a plate crossbow correction device provided with five pair of electromagnets.

[0145] As shown in both drawings, it can be understood that crossbow can be further suppressed at particularly the central portion in the plate width direction by increasing the number of pairs of electromagnets.

[0146] FIG. 13 is a characteristic diagram showing a relationship between numbers of pairs of electromagnets and plate crossbow at the position at which the wiping nozzle is disposed.

[0147] As shown in FIG. 13, it can be understood that plate crossbow can be effectively suppressed when four or more pairs of electromagnets are provided.

[0148] In this respect, while the hot-dip galvanizing line 10a comprised with the plate crossbow correction device 100 of the above-described first embodiment comprises in-bath rolls 4a, 4b, it is also possible to configure a hot-dip galvanizing line without in-bath rollers when plate crossbow correction can be reliably performed using the plate crossbow correction device 100.

Second Embodiment

[0149] A plate crossbow correction device 1000 according to the second embodiment will be explained with reference to FIG. 14 which is a plan view and FIG. 15 which is a front view when the device on the front surface side is seen from the strip side.

[0150] In FIG. 14 and FIG. 15, the configuration of the correction mechanism 100F on the front surface side and the correction mechanism 100B on the back surface side are identical to that shown in the first embodiment.

[0151] The correction mechanism 100F on the front surface side is arranged to be movable along the plate width direction of the strip by means of an overall moving mechanism 1100 on the front surface side. The correction mechanism 100B on the back surface side is arranged to be movable along the plate width direction of the strip by means of an overall moving mechanism 1200 on the back surface side.

[0152] The overall moving mechanism 1100 on the front surface side is comprised of a main frame 1101 and moving and supporting devices 1102, 1103 for supporting the main frame 1101 at both ends of the main frame 1101 to be movable along the plate width direction of the strip. The main frame 1101 supports the correction mechanism 100F.

[0153] Therefore, when the main frame 1101 moves along the plate width direction of the strip, the correction mechanism 100F moves as a whole in the same direction.

[0154] The overall moving mechanism 1200 on the back surface side is comprised of a main frame 1201 and moving and supporting devices 1202, 1203 for supporting the main frame 1201 at both ends of the main frame 1201 to be movable along the plate width direction of the strip. The main frame 1201 supports the correction mechanism 100B.

[0155] Therefore, when the main frame 1201 moves along the plate width direction of the strip, the correction mechanism 100B moves as a whole in the same direction.

[0156] In this case, moving operations of the moving and supporting devices 1102, 1103, 1202, and 1203 are controlled such that moving directions and moving distances of the main frame 1101 and the main frame 1201 become identical.

[0157] In the second embodiment, since the correction mechanisms 100F, 100B can be moved in the plate width direction of the strip as a whole, the correction mechanisms 100F, 100B can be moved in accordance therewith even if the strips largely meander so that crossbow of the strips can be reliably suppressed.

INDUSTRIAL APPLICABILITY

[0158] The present invention can be used for correcting crossbow of strips in molten metal plating facilities.