Control device for rolling device, rolling equipment, and method for operating rolling device

Abstract

A control apparatus for controlling a rolling mill apparatus including a pair of mill rolls for rolling a metal plate includes: a first strip-edge detection part configured to detect a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection part configured to detect a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a leveling adjustment part configured to adjust leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected by the first strip-edge detection part and a second strip-edge position of the metal plate detected by the second strip-edge detection part.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control apparatus for a rolling mill apparatus, a rolling mill facility, and a method for operating a rolling mill apparatus.BACKGROUND ART

[0002] In rolling of a metal plate using a rolling mill including a pair of mill rolls, the metal plate may be rolled in a strip head-end tensionless state where no tension is applied to the rolling mill exit side of the metal plate before the head end portion of the metal plate is rewound by a rewinder in order to improve the yield (strip head-end tensionless rolling).

[0003] Patent Document 1 discloses a rolling mill facility including a strip-edge detection part disposed on each of the entry side and the exit side of the pair of mill rolls (rolling mills). In the rolling mill facility, it is determined whether the metal plate is parallel to the conveyance direction (pass line) on the basis of the strip-edge position in the strip width direction at the entry side and the exit side of the mill roll detected by a strip-edge detection part, and the strip head-end tensionless rolling is started if the metal plate is substantially parallel to the conveyance direction. Furthermore, after rolling of the metal plate is started, the leveling is adjusted on the basis of the strip-edge position in the strip width direction on the exit side of the rolling mill, and inclination of the metal plate with respect to the conveyance direction is suppressed. Accordingly, the head end of the metal plate is guided to the rewinder while suppressing inclination of the metal plate.Citation ListPatent Literature

[0004] Patent Document 1: JP7150994BSUMMARYProblems to be Solved

[0005] However, in the rolling mill facility of Patent Document 1, the strip head-end tensionless rolling is started after the orientation of the metal plate is adjusted to be substantially parallel to the conveyance direction, and thus it requires time for adjusting orientation of the metal plate before rolling is started. Thus, there is room for improvement in terms of production efficiency.

[0006] In view of the above, an object of at least one embodiment of the present invention is to provide a control apparatus for a rolling mill apparatus, a rolling mill facility, and a method for operating a rolling mill apparatus capable of quickly starting rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling).Solution to the Problems

[0007] A control apparatus for controlling a rolling mill apparatus according to at least one embodiment of the present invention is a control apparatus for controlling a rolling mill apparatus including a pair of mill rolls for rolling a metal plate, and includes: a first strip-edge detection part configured to detect a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection part configured to detect a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a leveling adjustment part configured to adjust leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected by the first strip-edge detection part and a second strip-edge position of the metal plate detected by the second strip-edge detection part.

[0008] Furthermore, a rolling mill facility according to at least one embodiment of the present invention includes: a rolling mill apparatus including a pair of mill rolls for rolling a metal plate; and the control apparatus described above configured to control the rolling mill apparatus.

[0009] Furthermore, a method for operating a rolling mill apparatus according to at least one embodiment of the present invention is a method for operating a rolling mill apparatus including a pair of mill rolls for rolling a metal plate, and the method includes: a first strip-edge detection step of detecting a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection step of detecting a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a step of adjusting leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected in the first strip-edge detection step and a second strip-edge position of the metal plate detected in the second strip-edge detection step.Advantageous Effects

[0010] According to at least one embodiment of the present invention, it is possible to provide a control apparatus for a rolling mill apparatus, a rolling mill facility, and a method for operating a rolling mill apparatus capable of quickly starting rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling).BRIEF DESCRIPTION OF DRAWINGS

[0011] FIG. 1 is a schematic configuration diagram of a rolling mill facility including a control apparatus according to an embodiment. FIG. 2 is a schematic configuration diagram of a control apparatus according to an embodiment. FIG. 3 is a schematic planar view of a metal plate in a rolling mill facility. FIG. 4 is a schematic planar view of a metal plate in a rolling mill facility. FIG. 5 is a flowchart showing an example of a method for operating a rolling mill apparatus according to an embodiment. FIG. 6 is a flowchart showing an example of a method for operating a rolling mill apparatus according to an embodiment. FIG. 7 is a graph showing an example of correlation between the difference δ between the first strip-edge position and the second strip-edge position and the offset amount D. FIG. 8 is a graph showing an example of correlation between the difference δ between the first strip-edge position and the second strip-edge position and the offset amount D. DETAILED DESCRIPTION

[0012] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is intended, however, that unless particularly identified, dimensions, materials, shapes, relative positions and the like of components described in the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention.(Configuration of the rolling mill facility and the control apparatus)

[0013] FIG. 1 is a schematic configuration diagram of a rolling mill facility including a control apparatus according to an embodiment. FIG. 2 is a schematic configuration diagram of a control apparatus according to an embodiment.

[0014] As depicted in FIG. 1, the rolling mill facility 1 includes a rolling mill apparatus 2 for rolling a metal plate S and a control apparatus 100 for controlling the rolling mill apparatus 2. In some embodiments, the rolling mill apparatus 2 may include a single rolling mill 10 as depicted in FIG.1, or may include a plurality of rolling mills arranged in the conveyance direction of the metal plate.

[0015] The rolling mill apparatus 2 depicted in FIG. 1 is a rolling mill apparatus which causes the metal plate S inserted between the pair of mill rolls 15, 16 to reciprocate and rolls the metal plate S (reverse mill). The rolling mill apparatus 2 depicted in FIG. 1 includes a rolling mill 10 including a pair of mill rolls (work rolls) 15, 16 disposed so as to sandwich the metal plate S being a material to be rolled, an unwinder 4 disposed at the entry side of the mill rolls 15, 16 in the traveling direction of the metal plate S, and a rewinder 14 disposed on the exit side of the mill rolls 15, 16 in the traveling direction of the metal plate S, and is configured to roll the metal plate S with the pair of mill rolls 15, 16.

[0016] The rolling mill 10 includes, in addition to the pair of mill rolls (work rolls) 15, 16, a pair of intermediate rolls 17, 18 and a pair of backup rolls 19, 20 disposed opposite to the metal plate S across the pair of mill rolls 15, 16, respectively. The intermediate rolls 17, 18 and the backup rolls 19, 20 are configured to support the mill rolls 15, 16. Furthermore, the rolling mill10 includes a rolling reduction device 22 for rolling down the metal plate S sandwiched by the pair of mill rolls 15, 16 by applying a load to the pair of mill rolls 15, 16. The rolling reduction device 22 may include a hydraulic cylinder.

[0017] A motor (not depicted) is connected to the work rolls 15, 16 via a spindle (not depicted) or the like, such that the mill rolls 15, 16 are rotary driven by the motor. When the metal plate S is rolled, the motor rotates the mill rolls 15, 16 while the rolling reduction device 22 rolls down the metal plate S, and thereby a friction force is generated between the mill rolls 15, 16 and the metal plate S. The friction force sends the metal plate S to the output side of the mill rolls 15, 16.

[0018] The unwinder 4 is configured to unwind the metal plate S toward the rolling mill 10. The rewinder 14 is configured to rewind the metal plate S from the rolling mill 10. The unwinder 4 and the rewinder 14 are each driven by a motor (not depicted).

[0019] The unwinder 4 is configured to apply an entry-side tension to the metal plate S when the metal plate S is rolled. Furthermore, the rewinder 14 is configured to apply an exit-side tension to the metal plate S when the metal plate S is rolled. That is, by driving the unwinder 4 and the rewinder 14 appropriately with the motor, an entry side tension and an exit-side tension are applied to the metal plate S. By applying an entry side tension and an exit-side tension to the metal plate S, it is possible to suppress meandering of the metal plate S at the time of rolling.

[0020] Meanwhile, rolling is stopped immediately before the tail end of the metal plate S unwound from the unwinder 4, and once an even number of rolling (e.g., the first path) is completed while the metal plate S is rolled down by the mill rolls 15, 16, then, the metal plate S is unwound from the rewinder 14 toward the rolling mill 10, and the rewinder 14 rewinds the metal plate S while the metal plate S advances in the traveling direction opposite to the previous direction, and thereby rolling of an even number time (e.g., 2nd path) is performed. That is, the roles of the unwinder 4 and the rewinder 14 switch with one another in accordance with the traveling direction of the metal plate S.

[0021] The rolling mill apparatus 2 depicted in FIG. 1 includes an entry side pinch roll 6 and a side guide 8 for guiding the metal plate S introduced into the rolling mill 10 from the unwinder 4, and an exit side pinch roll 12 for guiding the metal plate S sent to the rewinder 14 from the rolling mill 10.

[0022] As depicted in FIG. 1, the control apparatus 100 for controlling the rolling mill apparatus 2 includes a first strip-edge detection part 32 and a second strip-edge detection part 34 for detecting the strip-edge position, in the strip width direction, of the metal plate S, and a controller 40 configured to control operation of the rolling mill apparatus 2 on the basis of the detection result of the first strip-edge detection part 32 and the second strip-edge detection part 34.

[0023] Herein, FIGs. 3 and 4 are each a schematic planar view of the metal plate S in the rolling mill facility 1. In the example illustrated in FIGs. 3 and 4, the metal plate S has a head end St, as well as strip edges Se A , Se B in the strip width direction. In FIGs. 3 and 4, the metal plate S at the time of arriving at the rewinder 14 is illustrated in two-dotted chain line. In FIG. 3, the orientation of the metal plate S (longitudinal direction of the metal plate S) is substantially parallel to the conveyance direction, and the position of the strip edge Se A is substantially the same as the target strip-edge position X A . In FIG. 4, orientation of the metal plate S is oblique with respect to the conveyance direction. Furthermore, in FIGs. 3 and 4, the position of the mill rolls 15, 16 in the conveyance direction of the metal plate S is indicated as 1x0, and the position of the rewinder 14 is indicated as lx3.

[0024] The first strip-edge detection part 32 is configured to detect the first strip-edge position x1 being the strip-edge position, in the strip width direction, of the metal plate S at the first position 1x1 on the exit side of the pair of mill rolls 15, 16 in the conveyance direction of the metal plate S (see FIGs. 3 and 4; the same applies hereinafter). The second strip-edge detection part 34 is configured to detect the second strip-edge position x2 being the strip-edge position, in the strip width direction, of the metal plate S at the second position lx2 downstream of the first position 1x1 in the conveyance direction. That is, the first position 1x1 and the second position lx2 are both positions on the exit side of the pair of mill rolls 15, 16 in the conveyance direction.

[0025] The control apparatus 100 may include an offset amount detection part 36 for detecting an offset amount D (see FIG. 4) being the difference between the strip-edge position x3 and the target strip-edge position X A of the metal plate S at the rewinder 14. The offset amount D may be the difference between the strip-edge position x3 of the head end St' of the metal plate S at the time when the head end of the metal plate S arrives at the rewinder 14 and the target strip-edge position X A (see FIG. 4).

[0026] The offset amount detection part 36 may include a camera capable of capturing an image of a mark or the like indicating the strip-edge position, in the strip width direction, of the metal plate S wound by the rewinder 14, and / or the target strip-edge position X A . The mark indicating the target strip-edge position X A may be disposed on the rewinder 14. The offset amount detection part 36 may be configured to acquire the above described offset amount D from an image or the like acquired by the camera.

[0027] The controller 40 is configured to receive signals indicating the first strip-edge position x1, the second strip-edge position x2, and / or the offset amount D from the first strip-edge detection part 32, the second strip-edge detection part 34, and / or the offset amount detection part 36, and control operation of the rolling reduction device 22 or the motor for driving the mill rolls 15, 16 on the basis of the detection results of the above.

[0028] The controller 40 may include a processor (CPU or the like), a memory (RAM), an auxiliary storage part, and an interface, for instance. The controller 40 is configured to receive signals from the first strip-edge detection part 32 and the second strip-edge detection part 34 via the interface. The processor is configured to process the accordingly received signals. Furthermore, the processor is configured to process the program expanded in the memory.

[0029] The content of process at the controller 40 may be implemented as programs to be executed by the processor, and stored in the auxiliary storage part. When the programs are executed, the programs are expanded in the memory. The processor is configured to read out the programs from the memory, and execute the orders contained in the programs.

[0030] As depicted in FIG. 2, the controller 40 constituting the control apparatus 100 according to an embodiment includes a leveling adjustment part 42. Furthermore, the controller 40 may include a target value acquisition part 44, a data acquisition part 46, and / or a correlation acquisition part 48.

[0031] The leveling adjustment part 42 is configured to adjust leveling of the pair of mill rolls 15, 16 rolling the metal plate S in a state where the exit-side tension of the metal plate S is zero (that is, in a strip head-end tensionless state) on the basis of the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32, the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34, and / or the offset amount D detected by the offset amount detection part 36. Herein, the leveling of the pair of mill rolls 15, 16 is the difference of the roll gaps at both end portions of the pair of mill rolls 15 ,16. The leveling adjustment part 42 may be configured to adjust the leveling of the mill rolls 15, 16 by adjusting the rolling reduction amount by the rolling reduction device 22.

[0032] The target value acquisition part 44 is configured to acquire the difference δ between the first strip-edge position x1 and the second strip-edge position x2 at which the offset amount D becomes a predetermined value as a target value δtgt related to the difference δ, on the basis of the correlation between the difference δ between the first strip-edge position x1 detected by the first strip-edge detection part 32 and the second strip-edge position x2 detected by the second strip-edge detection part 34 (see FIG. 4) and the above described offset amount D. The above described correlation may be acquired by the correlation acquisition part 48 described below.

[0033] The data acquisition part 46 is configured to acquire, over a plurality of times, each of the difference δ between the first strip-edge position x1 and the second strip-edge position x2, and the above described offset amount D corresponding to the difference δ.

[0034] The correlation acquisition part 48 is configured to acquire the correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the above described offset amount D, on the basis of a plurality of differences δ and a plurality of offset amounts D acquired by the data acquisition part 46.(Flow of operation control for the rolling mill apparatus)

[0035] In the following description, the operation control for the rolling mill apparatus 2 using the above described control apparatus 100 will be described. Nevertheless, a part or all of the processes performed by the control apparatus 100 described below may be performed manually to operate the rolling mill apparatus 2.

[0036] FIGs. 5 and 6 are each a flowchart showing an example of a method for operating a rolling mill apparatus according to an embodiment.

[0037] In the operation method illustrated in the flowchart of FIG. 5, firstly at the rolling mill apparatus 2, rolling of the metal plate S in a state where the exit-side tension of the metal plate S is zero (strip head-end tensionless rolling) is started (S2). During the strip head-end tensionless rolling, the head end St of the metal plate S is positioned downstream of the mill rolls 15, 16 in the conveyance direction, and at the upstream side of the rewinder 14 (see FIGs. 3 and 4).

[0038] Next, the first strip-edge detection part 32 detects the first strip-edge position x1 of the metal plate S at the first position 1x1 in the conveyance direction, and the second strip-edge detection part 34 detects the second strip-edge position x2 of the metal plate S at the second position lx2 in the conveyance direction (S4). The controller 40 acquires the first strip-edge position x1 and the second strip-edge position x2.

[0039] Next, the leveling adjustment part 42 adjusts leveling of the pair of mill rolls 15, 16 rolling the metal plate S in a state where the exit-side tension of the metal plate S is zero on the basis of the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32 and the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34 (S6 to S10).

[0040] More specifically, the leveling adjustment part 42 acquires the difference δ (δ = x2-x1; see FIG. 4) between the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32 and the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34 (S6).

[0041] Furthermore, the leveling adjustment part 42 determines whether the difference δ between the first strip-edge position x1 and the second strip-edge position x2 is within a predetermined range (S8). Then, if the above described difference δ is not within the predetermined range (No in step S8), the leveling adjustment part 42 changes the leveling of the mill rolls 15, 16 so that the difference δ falls within the predetermined range (S10).

[0042] Alternatively, in an embodiment, instead of the above described steps S8 to S10, the difference δ between the first strip-edge position x1 and the second strip-edge position x2 may be acquired, and the leveling of the mill rolls 15, 16 may be adjusted so that the difference δ becomes smaller (that is, so that the difference δ between the first strip-edge position x1 and the second strip-edge position x2 becomes smaller).

[0043] According to the above described embodiment, while rolling in a state where the exit-side tension of the metal plate S is zero (strip head-end tensionless rolling), the leveling is adjusted on the basis of the detection result of the strip-edge positions (the first strip-edge position x1 and the second strip-edge position x2) at a plurality of positions (the first position 1x1 and the second position Ix2) on the exit side of the pair of mill rolls 15, 16. Thus, even if the metal plate S is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling as illustrated in FIG. 4, it is possible to resolve the inclination of the metal plate S while rolling the metal plate S by the above described leveling adjustment. Accordingly, it is possible to guide the head end St of the metal plate S to the rewinder 14 while maintaining the straight-moving property of the metal plate S during the strip head-end tensionless rolling, and rewind the metal plate S with the rewinder 14 appropriately. Therefore, it is possible to omit adjustment of the orientation of the metal plate S at the time of start of the strip head-end tensionless rolling, and thus it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0044] In the operation method illustrated in the flowchart of FIG. 6, firstly at the rolling mill apparatus 2, rolling of the metal plate S in a state where the exit-side tension of the metal plate S is zero (strip head-end tensionless rolling) is started (S22; similar to step S2 in FIG. 5).

[0045] Next, the target value acquisition part 44 acquires the correlation between the difference δ between the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32 and the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34 and the offset amount D being a difference between the strip-edge position x3 of the metal plate S at the rewinder 14 and the target strip-edge position X A . Furthermore, the target value acquisition part 44 acquires a target value δtgt related to the above described difference δ between the first strip-edge position x1 and the second strip-edge position x2 at which the offset amount D becomes a predetermined value (typically, zero) from the correlation (S24).

[0046] The correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D may be acquired by the correlation acquisition part 48 on the basis of the data of the first strip-edge position x1, the second strip-edge position x2, and the offset amount D acquired by the data acquisition part 46.

[0047] FIGs. 7 and 8 are each a graph showing an example of correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 (x-axis) and the offset amount D (y-axis).

[0048] The correlation acquisition part 48 may obtain an approximate curve (curve L in FIGs. 7 and 8) of the plot indicating a combination of the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D, and acquire the approximate curve L as the correlation between the above described difference δ and the offset amount D. Furthermore, the target value acquisition part 44 may acquire the value of δ at an intersection of the above described approximate curve L and x-axis indicating δ, as the target value δtgt related to the above difference δ at which the offset amount D becomes zero as a predetermined value.

[0049] If there is no measurement error or installment error of the first strip-edge detection part 32, the second strip-edge detection part 34, and / or the offset amount detection part 36, the approximate curve L indicating the correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D passes through the origin point as shown in FIG. 7 (that is, when the offset amount D is zero, the difference δ between the first strip-edge position x1 and the second strip-edge position x2 is zero). In this case, the target value δtgt related to the difference δ between the first strip-edge position x1 and the second strip-edge position x2 at which the offset amount D becomes zero (the predetermined value) is zero.

[0050] In practice, due to a measurement error or an installment error of the first strip-edge detection part 32, the second strip-edge detection part 34, and / or the offset amount detection part 36, when the offset amount D is zero in the correlation between the above described difference δ and the offset amount D, the difference δ between the first strip-edge position x1 and the second strip-edge position x2 may become offset from zero by δa, as shown in FIG. 8. In this case, the target value δtgt related to the difference δ between the first strip-edge position x1 and the second strip-edge position x2 at which the offset amount D becomes a predetermined value is δa.

[0051] Next, the first strip-edge detection part 32 detects the first strip-edge position x1 of the metal plate S at the first position 1x1 in the conveyance direction, and the second strip-edge detection part 34 detects the second strip-edge position x2 of the metal plate S at the second position lx2 in the conveyance direction (S26; similar to step S4 in FIG. 5). The controller 40 acquires the first strip-edge position x1 and the second strip-edge position x2.

[0052] Next, the leveling adjustment part 42 adjusts leveling of the pair of mill rolls 15, 16 rolling the metal plate S in a state where the exit-side tension of the metal plate S is zero using the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32, the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34, and the above described offset amount D (S28 to S30).

[0053] More specifically, the leveling adjustment part 42 acquires the difference δ between the first strip-edge position x1 of the metal plate S detected by the first strip-edge detection part 32 and the second strip-edge position x2 of the metal plate S detected by the second strip-edge detection part 34 (S28).

[0054] Then, the leveling adjustment part 42 adjusts leveling of the mill rolls 15, 16 so that the difference δ between the first strip-edge position x1 and the second strip-edge position x approaches the target value δtgt acquired in step S24 (that is, the target value δtgt acquired on the basis of the correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D) (S30).

[0055] As a result of intensive research conducted by the present inventors, it was found that, even if there is in practice no difference between the strip-edge positions at the first position 1x1 and the second position lx2 (the first strip-edge position x1 and the second strip-edge position x2), a difference may occur in the detection results (measurement values) of the first strip-edge position x1 and the second strip-edge position x2 detected by the first strip-edge detection part 32 and the second strip-edge detection part 34, due to a measurement error or an installment error of the strip-edge detection parts. In this regard, according to the above described embodiment, in addition to the detection results by the first strip-edge detection part 32 and the second strip-edge detection part 34 (the first strip-edge position x1 and the second strip-edge position x2), by adjusting leveling using the offset amount D being a difference between the strip-edge position x3 of the metal plate S at the position of the rewinder 14 and the target strip-edge position X A , it is possible to resolve inclination of the metal plate S with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0056] For instance, as described above, by acquiring the target value δtgt corresponding to a predetermined offset amount D (e.g. zero) on the basis of the correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the above described offset amount D as described above, and adjusting leveling so that the difference δ between the first strip-edge position x1 and the second strip-edge position x2 approaches the target value δtgt, it is possible to bring the offset amount D closer to the predetermined value (e.g. zero). Accordingly, it is possible to resolve inclination of the metal plate S with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0057] In some embodiments, the data acquisition part 46 is configured to acquire the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D repetitively, and the correlation acquisition part 48 is configured to reacquire the correlation between the difference δ and the offset amount D (e.g., the above described approximate curve L) each time the data acquisition part 46 acquires the above described difference δ and the offset amount D.

[0058] The correlation between the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the above described offset amount D may change depending on the operation time, the operation state, or the like of the rolling mill facility 1. In this regard, according to the above described embodiment, the data related to the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D corresponding to the difference δ is acquired repetitively during operation of the rolling mill facility 1, and the above described correlation is reacquired using the newly acquired data (that is, the correlation is updated). Accordingly, it is possible to adjust leveling on the basis of the above described correlation corresponding to the state of the rolling mill facility 1, and thus it is possible to resolve inclination of the metal plate S with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0059] In some embodiments, the correlation acquisition part 48 is configured to acquire the correlation using newer ones selected from a plurality of above described differences δ and a plurality of offset amounts D acquired by the data acquisition part 46.

[0060] According to the above described embodiment, the above described correlation is acquired using latest ones from the data related to the difference δ between the first strip-edge position x1 and the second strip-edge position x2 and the offset amount D corresponding to the difference δ acquired during operation of the rolling mill facility 1, and thus it is possible to adjust leveling on the basis of the above described correlation corresponding to the latest state of the rolling mill facility 1. Thus, it is possible to resolve inclination of the metal plate S with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0061] The contents described in the above respective embodiments can be understood as follows, for instance. (1) A control apparatus (100) for controlling a rolling mill apparatus according to at least one embodiment of the present invention is a control apparatus for controlling a rolling mill apparatus (2) including a pair of mill rolls (15, 16) for rolling a metal plate (S) and includes: a first strip-edge detection part (32) configured to detect a strip-edge position, in a strip width direction, of the metal plate at a first position (lx1) on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection part (34) configured to detect a strip-edge position, in the strip width direction, of the metal plate at a second position (lx2) downstream of the first position in the conveyance direction; and a leveling adjustment part (42) configured to adjust leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position (x1) of the metal plate detected by the first strip-edge detection part and a second strip-edge position (x2) of the metal plate detected by the second strip-edge detection part.

[0062] According to the above configuration (1), during rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling), the leveling is adjusted on the basis of the detection result of the strip-edge positions (the first strip-edge position and the second strip-edge position) at a plurality of positions (the first position and the second position) on the exit side of the pair of mill rolls. Thus, even if the metal plate is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling, it is possible to resolve the inclination of the metal plate while rolling the metal plate, by the above described leveling adjustment. Accordingly, it is possible to guide the head end of the metal plate to the rewinder while maintaining the straight-moving property of the metal plate during the strip head-end tensionless rolling, and rewind the metal plate with the rewinder appropriately. Therefore, it is possible to omit adjustment of the orientation of the metal plate at the time of start of the strip head-end tensionless rolling, and thus it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0063] (2) In some embodiments, in the above configuration (1), the leveling adjustment part is configured to adjust the leveling such that a difference (δ) between the first strip-edge position and the second strip-edge position falls within a predetermined range.

[0064] According to the above configuration (2), during rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling), the leveling is adjusted so that the difference between the first strip-edge position and the second strip-edge position falls within a predetermined range. Thus, even if the metal plate is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling, it is possible to resolve the inclination of the metal plate appropriately while rolling the metal plate, by the above described leveling adjustment. Therefore, as described in the above (1), it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0065] (3) In some embodiments, in the above configuration (1) or (2), the leveling adjustment part is configured to adjust the leveling such that a difference between the first strip-edge position and the second strip-edge position becomes smaller.

[0066] According to the above configuration (3), during rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling), the leveling is adjusted so that the difference between the first strip-edge position and the second strip-edge position becomes smaller (that is, so that the difference between the first strip-edge position and the second strip-edge position approaches zero). Thus, even if the metal plate is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling, it is possible to resolve the inclination of the metal plate appropriately while rolling the metal plate, by the above described leveling adjustment. Therefore, as described in the above (1), it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0067] (4) In some embodiments, in the above configuration (1), the leveling adjustment part is configured to adjust the leveling using an offset amount (D) being a difference between a strip-edge position (x3) of the metal plate at a rewinder (14) for rewinding the metal plate rolled by the pair of mill rolls and a target strip-edge position (X A ).

[0068] As a result of intensive research conducted by the present inventors, it was found that, even if in practice there is no difference in the strip-edge positions at the first position and the second position, a difference may occur in the detection results (measurement values) of the first strip-edge position and the second strip-edge position detected by the first strip-edge detection part and the second strip-edge detection part, due to a measurement error or an installment error of the strip-edge detection parts. According to the above described configuration (4), in addition to the detection results by the first strip-edge detection part and the second strip-edge detection part (the first strip-edge position and the second strip-edge position), by adjusting leveling using the offset amount being a difference between the strip-edge position of the metal plate at the position of the rewinder and the target strip-edge position, it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0069] (5) In some embodiments, in the above configuration (4), the leveling adjustment part is configured to adjust the leveling on the basis of correlation between a difference between the first strip-edge position and the second strip-edge position and the offset amount.

[0070] As a result of intensive research conducted by the present inventors, it was found that there is a correlation between the difference between the first strip-edge position (detection result by the first strip-edge detection part) and the second strip-edge position (detection result by the second strip-edge detection part) and the above described offset amount. According to the above configuration (5), the leveling is adjusted on the basis of the correlation between the difference between the first strip-edge position and the second strip-edge position and the above described offset amount, it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0071] (6) In some embodiments, in the above configuration (5), the control apparatus includes a target value acquisition part (44) configured to acquire, as a target value (δtgt), the difference between the first strip-edge position and the second strip-edge position at which the offset amount becomes a predetermined value, on the basis of the correlation. The leveling adjustment part is configured to adjust the leveling so that the difference between the first strip-edge position and the second strip-edge position approaches the target value.

[0072] According to the above configuration (6), the difference between the first strip-edge position and the second strip-edge position at which the above described offset amount becomes a predetermined value (e.g. zero) is acquired as a target value from the correlation between the difference between the first strip-edge position and the second strip-edge position and the above described offset amount, and the leveling is adjusted so that the difference between the first strip-edge position and the second strip-edge position approaches the target value. Thus, it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0073] (7) In some embodiments, in any one of the above configurations (4) to (6), the control apparatus includes: an offset amount detection part (36) for detecting the offset amount; a data acquisition part (46) configured to acquire, over a plurality of times, each of a difference between the first strip-edge position and the second strip-edge position and the offset amount corresponding to the difference; and a correlation acquisition part (48) configured to acquire the correlation on the basis of a plurality of differences and a plurality of offset amounts acquired by the data acquisition part.

[0074] According to the above configuration (7), the difference between the first strip-edge position and the second strip-edge position and the offset amount corresponding to the difference are acquired repetitively during operation of the rolling mill facility, and the correlation between the difference between the first strip-edge position and the second strip-edge position and the above described offset amount is acquired on the basis of the acquired data. Accordingly, it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately by adjusting leveling on the basis of the above described correlation.

[0075] (8) In some embodiments, in the above configuration (7), the data acquisition part is configured to acquire the difference and the offset amount repetitively, and the correlation acquisition part is configured to reacquire the correlation each time the data acquisition part acquires the difference and the offset amount.

[0076] The correlation between the difference between the first strip-edge position and the second strip-edge position and the above described offset amount may change depending on the operation time, the operation state, or the like of the rolling mill facility. According to the above configuration (8), the data related to the difference between the first strip-edge position and the second strip-edge position and the offset amount corresponding to the difference is acquired repetitively during operation of the rolling mill facility, and the above described correlation is reacquired using the newly acquired data (that is, the correlation is updated). Accordingly, it is possible to adjust leveling on the basis of the above described correlation corresponding to the state of the rolling mill facility, and thus it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0077] (9) In some embodiments, in the above configuration (7) or (8), the correlation acquisition part is configured to acquire the correlation using newer ones selected from the plurality of differences and the plurality of offset amounts acquired by the data acquisition part.

[0078] According to the above configuration (9), the above described correlation is acquired using latest ones from the data related to the difference between the first strip-edge position and the second strip-edge position acquired during operation of the rolling mill facility and the offset amount corresponding to the difference, and thus it is possible to adjust leveling on the basis of the above described correlation corresponding to the latest state of the rolling mill facility. Thus, it is possible to resolve inclination of the metal plate with respect to the conveyance direction during strip head-end tensionless rolling more appropriately.

[0079] (10) A rolling mill facility (1) according to at least one embodiment of the present invention includes: a rolling mill apparatus (2) including a pair of mill rolls for rolling a metal plate; and the control apparatus according to any one of the above (1) to (9) configured to control the rolling mill apparatus.

[0080] According to the above configuration (10), during rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling), the leveling is adjusted on the basis of the detection result of the strip-edge positions (the first strip-edge position and the second strip-edge position) at a plurality of positions (the first position and the second position) on the exit side of the pair of mill rolls. Thus, even if the metal plate is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling, it is possible to resolve the inclination of the metal plate while rolling the metal plate, by the above described leveling adjustment. Accordingly, it is possible to guide the head end of the metal plate to the rewinder while maintaining the straight-moving property of the metal plate during the strip head-end tensionless rolling, and rewind the metal plate with the rewinder appropriately. Therefore, it is possible to omit adjustment of the orientation of the metal plate at the time of start of the strip head-end tensionless rolling, and thus it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0081] (11) A method for operating a rolling mill apparatus according to at least one embodiment of the present invention is a method for operating a rolling mill apparatus including a pair of mill rolls for rolling a metal plate, and includes: a first strip-edge detection step (S4, S26) of detecting a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection step (S4, S26) of detecting a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a step (S8-S10, S30) of adjusting leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected in the first strip-edge detection step and a second strip-edge position of the metal plate detected in the second strip-edge detection step.

[0082] According to the above method (11), during rolling in a state where the exit-side tension of the metal plate is zero (strip head-end tensionless rolling), the leveling is adjusted on the basis of the detection result of the strip-edge positions (the first strip-edge position and the second strip-edge position) at a plurality of positions (the first position and the second position) on the exit side of the pair of mill rolls. Thus, even if the metal plate is inclined with respect to the conveyance direction at the time of start of the strip head-end tensionless rolling, it is possible to resolve the inclination of the metal plate while rolling the metal plate, by the above described leveling adjustment. Accordingly, it is possible to guide the head end of the metal plate to the rewinder while maintaining the straight-moving property of the metal plate during the strip head-end tensionless rolling, and rewind the metal plate with the rewinder appropriately. Therefore, it is possible to omit adjustment of the orientation of the metal plate at the time of start of the strip head-end tensionless rolling, and thus it is possible to start the strip head-end tensionless rolling quickly, which improves the production efficiency.

[0083] Embodiments of the present invention were described in detail above, but the present invention is not limited thereto, and various amendments and modifications may be implemented.

[0084] In the present specification, an expression of relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function. For instance, an expression of an equal state such as "same" "equal" and "uniform" shall not be construed as indicating only the state in which the feature is strictly equal, but also includes a state in which there is a tolerance or a difference that can still achieve the same function. Further, for instance, an expression of a shape such as a rectangular shape or a cylindrical shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved. On the other hand, an expression such as "comprise", "include", "have", "contain" and "constitute" are not intended to be exclusive of other components.Reference Signs List

[0085] 1Rolling mill facility 2Rolling mill apparatus 4Unwinder 6Entry-side pinch roll 8Side guide 10Rolling mill 12Exit-side pinch roll 14Rewinder 15Mill roll 16Mill roll 17Intermediate roll 18Intermediate roll 19Backup roll 20Backup roll 22Rolling reduction device 32First strip-edge detection part 34Second strip-edge detection part 36Offset amount detection part 40Controller 42Leveling adjustment part 44Target value acquisition part 46Data acquisition part 48Correlation acquisition part 100Control apparatus DOffset amount LApproximate curve SMetal plate Se A Strip edge Se B Strip edge StHead end St'Head end X A Target strip-edge position 1x1First position lx2Second position x1First strip-edge position x2Second strip-edge position x3Strip-edge position at the rewinder 14 δtgtTarget value

Claims

1. A control apparatus for controlling a rolling mill apparatus including a pair of mill rolls for rolling a metal plate, the control apparatus comprising: a first strip-edge detection part configured to detect a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection part configured to detect a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a leveling adjustment part configured to adjust leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected by the first strip-edge detection part and a second strip-edge position of the metal plate detected by the second strip-edge detection part.

2. The control apparatus for a rolling mill apparatus according to claim 1, wherein the leveling adjustment part is configured to adjust the leveling such that a difference between the first strip-edge position and the second strip-edge position falls within a predetermined range.

3. The control apparatus for a rolling mill apparatus according to claim 1 or 2, wherein the leveling adjustment part is configured to adjust the leveling such that a difference between the first strip-edge position and the second strip-edge position becomes smaller.

4. The control apparatus for a rolling mill apparatus according to claim 1, wherein the leveling adjustment part is configured to adjust the leveling using an offset amount being a difference between a strip-edge position of the metal plate at a rewinder for rewinding the metal plate rolled by the pair of mill rolls and a target strip-edge position.

5. The control apparatus for a rolling mill apparatus according to claim 4, wherein the leveling adjustment part is configured to adjust the leveling on the basis of correlation between a difference between the first strip-edge position and the second strip-edge position and the offset amount.

6. The control apparatus for a rolling mill apparatus according to claim 5, comprising: a target value acquisition part configured to acquire, as a target value, the difference between the first strip-edge position and the second strip-edge position at which the offset amount becomes a predetermined value, on the basis of the correlation, wherein the leveling adjustment part is configured to adjust the leveling so that the difference between the first strip-edge position and the second strip-edge position approaches the target value.

7. The control apparatus for a rolling mill apparatus according to any one of claims 4 to 6, comprising: an offset amount detection part for detecting the offset amount; a data acquisition part configured to acquire, over a plurality of times, each of a difference between the first strip-edge position and the second strip-edge position and the offset amount corresponding to the difference; and a correlation acquisition part configured to acquire the correlation on the basis of a plurality of differences and a plurality of offset amounts acquired by the data acquisition part.

8. The control apparatus for a rolling mill apparatus according to claim 7, wherein the data acquisition part is configured to acquire the difference and the offset amount repetitively, and wherein the correlation acquisition part is configured to reacquire the correlation each time the data acquisition part acquires the difference and the offset amount.

9. The control apparatus for a rolling mill apparatus according to claim 7, wherein the correlation acquisition part is configured to acquire the correlation using newer ones selected from the plurality of differences and the plurality of offset amounts acquired by the data acquisition part.

10. A rolling mill facility, comprising: a rolling mill apparatus including a pair of mill rolls for rolling a metal plate; and the control apparatus according to claim 1 or 2 configured to control the rolling mill apparatus.

11. A method for operating a rolling mill apparatus including a pair of mill rolls for rolling a metal plate, the method comprising: a first strip-edge detection step of detecting a strip-edge position, in a strip width direction, of the metal plate at a first position on an exit side of the pair of mill rolls in a conveyance direction of the metal plate; a second strip-edge detection step of detecting a strip-edge position, in the strip width direction, of the metal plate at a second position downstream of the first position in the conveyance direction; and a step of adjusting leveling of the pair of mill rolls rolling the metal plate in a state where an exit-side tension of the metal plate is zero, on the basis of a first strip-edge position of the metal plate detected in the first strip-edge detection step and a second strip-edge position of the metal plate detected in the second strip-edge detection step.

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