WO2024241553A1 - Control device for rolling machine, rolling machine, method for operating rolling machine, and control program for rolling machine - Google Patents

Abstract

Provided is a control device for controlling a rolling machine including: a pair of rollers for rolling a metal strip; and an unwinder that includes a mandrel having a gripping part for gripping a tail end portion of the metal strip, and that unwinds the metal strip toward the pair of rollers. The control device comprises: a roller control unit configured to control rotation of the pair of rollers on the basis of the deviation between a target velocity and an actual velocity of the metal strip; and an unwinder control unit configured to control torque of the unwinder on the basis of the deviation between target tension and actual tension of the metal strip between the unwinder and the pair of rollers. The control device is configured to reduce the target velocity, or reduce the target tension, so that a circumferential velocity of the mandrel is greater than the velocity of the metal strip on the unwinding side, during a first period immediately before the tail end of the metal strip leaves the unwinder.

Description

Control device for rolling mill, rolling mill, operating method for rolling mill, and control program for rolling mill

The present disclosure relates to a control device for a rolling device, a rolling device, an operating method for a rolling device, and a control program for a rolling device.

In a rolling device that includes an unwinder and a winder, the ends (tip and tail) of the metal strip, which is the rolled material, in the longitudinal direction are usually held while inserted into slots provided in the winder or unwinder.

Patent Document 1 discloses a winding device in which, when winding a metal strip, the leading end of the metal strip is inserted into a slot provided in the mandrel of the winding machine, and the winding machine is rotated to wind up the metal strip while the leading end of the metal strip is gripped by a gripper in the slot.

Patent document 2 discloses a reverse rolling device that continues rolling even after the tail end of the metal strip leaves the unwinder.

Patent No. 6986114 JP 2000-202503 A

During rolling of the metal strip, the tail end of the metal strip is inserted into the slot of the unwinder, so the shape of the tail end is bent downward according to the shape of the slot, and usually this bent downward shape (plastic deformation) remains even after it leaves the unwinder.

Here, in a reverse rolling device (e.g., Patent Document 2), in which a metal strip is rolled while being moved back and forth, the tail end of the metal strip that comes out of the slot of the mandrel that functions as an unwinder becomes the leading end in the next pass, and is wound up on the same mandrel (the mandrel that functions as a winder). At this time, if the leading end of the metal strip (the tail end in the previous pass) is bent downward as described above, the leading end will get caught on the conveying path when the metal strip is conveyed, making it difficult to thread the strip. This can reduce the production efficiency of the product.

In view of the above, at least one embodiment of the present invention aims to provide a control device for a rolling device, a rolling device, an operating method for a rolling device, and a control program for a rolling device that enable smooth sheet threading at the start of a rolling pass.

A control device for a rolling mill according to at least one embodiment of the present invention comprises:
A control device for controlling a rolling apparatus including a pair of rolling rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end portion of the metal strip, and for unwinding the metal strip toward the pair of rolling rolls,
a roll control unit configured to control rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinder control unit configured to control a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
The method is configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinding machine.

Further, a rolling apparatus according to at least one embodiment of the present invention includes:
A pair of rolls for rolling the metal strip;
an unwinder for unwinding the metal strip toward the pair of rolling rolls, the unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip;
The control device described above is configured to control the pair of rolling rolls and the unwinder; and
Equipped with.

Further, a rolling apparatus according to at least one embodiment of the present invention includes:
A pair of rolls for rolling the metal strip;
an unwinder for unwinding the metal strip toward the pair of rolling rolls, the unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip;
Equipped with
The metal strip includes a gripped portion gripped by the gripping portion and an adjacent portion adjacent to the gripped portion in a longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip (or a folding angle formed between a straight line along the gripped portion and a straight line along the adjacent portion in the direction of rotation of the mandrel) is 180 degrees or more,
The tail end of the metal strip is configured to separate from the unwinder when the angle becomes smaller than 180 degrees at the end of unwinding of the metal strip from the unwinder.

Further, a method for operating a rolling apparatus according to at least one embodiment of the present invention includes:
A method for operating a rolling mill including a pair of rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip, and unwinding the metal strip toward the pair of rolls, comprising the steps of:
a roll control step of controlling rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinding mechanism step configured to control a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
During a first period immediately before the tail end of the metal strip separates from the unwinder, the target speed is reduced or the target tension is reduced so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side.

Further, a method for operating a rolling apparatus according to at least one embodiment of the present invention includes:
A method for operating a rolling mill including a pair of rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip, and unwinding the metal strip toward the pair of rolls, comprising the steps of:
The metal strip includes a gripped portion gripped by the gripping portion and an adjacent portion adjacent to the gripped portion in a longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip is 180 degrees or more;
The method further includes a step of releasing the tail end of the metal strip from the unwinder when the angle becomes smaller than 180 degrees at the end of unwinding of the metal strip from the unwinder.

Further, a control program for a rolling apparatus according to at least one embodiment of the present invention comprises:
A program for controlling a rolling apparatus including a pair of rolling rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end portion of the metal strip and for unwinding the metal strip toward the pair of rolling rolls,
On the computer,
a step of controlling the rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
controlling a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
configured to execute
The method is configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinding machine.

At least one embodiment of the present invention provides a control device for a rolling device, a rolling device, an operating method for a rolling device, and a control program for a rolling device that enable smooth threading of a plate at the start of a rolling pass.

1 is a schematic configuration diagram of a rolling mill to which a control device according to an embodiment is applied; FIG. 2 is a partial cross-sectional view of an unwinder (winder) according to one embodiment. FIG. 2 is a schematic configuration diagram of a control device 50 according to an embodiment. 4 is a flowchart of a method for operating a rolling mill according to one embodiment. 5 is a graph showing an example of time variations in target speed, target tension, and mandrel peripheral speed of a metal strip according to an operating method according to an embodiment. FIG. 4 is a schematic diagram for explaining a change in shape of the tail end of a metal strip due to an operation method according to an embodiment. FIG. 4 is a schematic diagram for explaining a change in shape of the tail end of a metal strip due to an operation method according to an embodiment. FIG. 4 is a schematic diagram for explaining a change in shape of the tail end of a metal strip due to an operation method according to an embodiment. FIG. 4 is a schematic diagram for explaining a change in shape of the tail end of a metal strip due to an operation method according to an embodiment. FIG. 2 is a schematic diagram for explaining the change in shape of the tail end of a metal strip due to a general operating method. 4 is a flowchart of a method for operating a rolling mill according to one embodiment.

Below, several embodiments of the present invention will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention and are merely illustrative examples.

(Configuration of the rolling device)
FIG. 1 is a schematic diagram of a rolling apparatus to which a control device according to an embodiment is applied. As shown in FIG. 1, the rolling apparatus 1 includes a rolling mill 10 including a pair of rolling rolls 15, 16 for rolling a metal strip S (e.g., a steel strip), an unwinder 2 provided on the entry side of the rolling mill 10 (i.e., the upstream side of the rolling mill 10 in the traveling direction of the metal strip S being rolled), and a winder 3 provided on the exit side of the rolling mill 10 (i.e., the downstream side of the rolling mill 10 in the traveling direction of the metal strip S being rolled). The rolling apparatus 1 also includes a control device 50 for controlling the pair of rolling rolls 15, 16 and the unwinder 2. The rolling apparatus 1 may include, for example, one rolling mill 10 as shown in FIG. 1, or may include two or more rolling mills 10.

The rolling mill 10 includes a pair of rolling rolls (work rolls) 15, 16 that are provided on both sides of the metal strip S, sandwiching the metal strip S. As shown in FIG. 1, the rolling mill 10 may also include a pair of intermediate rolls 17, 18 and a pair of backup rolls 19, 20 that are provided on the opposite side of the metal strip S, sandwiching the pair of rolling rolls 15, 16. The intermediate rolls 17, 18 and the backup rolls 19, 20 are configured to support the rolling rolls 15, 16. The rolling mill 10 also includes a reduction device (hydraulic cylinder, etc.; not shown) for applying a load to the pair of rolling rolls 15, 16 to reduce the metal strip S between the pair of rolling rolls 15, 16.

The rolling rolls 15, 16 are connected to a motor 11 via a spindle (not shown) or the like, and the rolling rolls 15, 16 are rotated by the motor. When rolling the metal strip S, the rolling rolls 15, 16 are rotated by the motor 11 while the metal strip S is being pressed down by the pressing device, generating frictional force between the rolling rolls 15, 16 and the metal strip S, and this frictional force sends the metal strip S to the exit side of the rolling rolls 15, 16.

The unwinder 2 is configured to unwind a coil of metal strip S toward the rolling mill 10. The unwinder 2 includes a mandrel 4, which is rotated and driven by a motor 26 to unwind the metal strip S toward the rolling mill 10. The mandrel 4 of the unwinder 2 is driven by the motor 26 to apply an entry tension to the metal strip S when rolling the metal strip S.

The winding machine 3 is configured to wind up the metal strip S from the rolling mill 10. The winding machine 3 includes a mandrel 5, which is rotated and driven by a motor (not shown) to wind up the metal strip S. When the metal strip S is rolled while being wound around the mandrel 5 of the winding machine 3, an outlet tension is applied to the metal strip S by the mandrel 5 of the winding machine 3.

As shown in FIG. 1, guide rolls 6, 7 for guiding the metal strip S may be provided between the mandrel 4 of the unwinder 2 and the rolling mill 10, and between the mandrel 5 of the winder 3 and the rolling mill 10.

In some embodiments, the rolling device 1 is a reverse-type rolling device (reverse mill) that rolls the metal strip S passing between a pair of rolling rolls 15, 16 by moving it back and forth. In the reverse-type rolling device 1, rolling is stopped just before the tail end St of the metal strip S unwound from the mandrel 4 of the unwinder 2, and the odd-numbered rolling (first pass, etc.) is completed with the metal strip S pressed down by the rolling rolls 15, 16. Next, the metal strip S is unwound from the mandrel 5 of the winder 3 toward the rolling mill 10, and while the metal strip S is wound around the mandrel 4 of the unwinder 2, the metal strip S is advanced in the opposite direction to the previous rolling, and the even-numbered rolling (second pass, etc.) is performed. In other words, the roles of the unwinder 2 and the winder 3 are switched depending on the direction of travel of the metal strip S.

FIG. 2 is a partial cross-sectional view of the unwinder 2 (winder 3) according to one embodiment, and is a diagram for explaining the operation of the unwinder 2 (winder 3). As shown in FIGS. 1 and 2, the unwinder 2 includes a gripper 22 (gripping portion) for gripping the tail end portion, including the tail end St, of the metal strip S. In addition, the winder 3 includes a gripper 23 for gripping the leading end portion, including the leading end, of the metal strip S.

In the exemplary embodiment shown in FIG. 2, the grippers 22, 23 are arranged to be movable radially inward of the mandrels 4, 5 relative to the outer circumferential surfaces of the mandrels 4, 5. The mandrels 4, 5 are provided with slots 24 that open to the surfaces of the mandrels 4, 5 and can receive the tail or tip of the metal strip S. The grippers 22, 23 are moved radially outward by an actuator (not shown) or the like, and a force is applied from the grippers 22, 23 toward the mandrels 4, 5 to the metal strip S, whereby the tail or tip of the metal strip S is gripped.

When rolling the metal strip S with the rolling device 1, basically, the grippers 22, 23 grip the tail and tip of the metal strip S, and tension is applied to the metal strip S by winding it around the mandrel, while the rolling rolls 15, 16 and the mandrels 4, 5 of the unwinder 2 and winder 3 are rotated.

As shown in FIG. 1, the rolling device 1 includes a speed measurement unit 28 for measuring the speed of the metal strip S (speed in the traveling direction; material speed). The speed measurement unit 28 may include a motor rotation speed detector for detecting the motor rotation speed for driving the pair of rolling rolls 15, 16, and may calculate the speed of the metal strip S based on the detection result of the motor rotation speed. Alternatively, the speed measurement unit 28 may include a speed sensor for detecting the speed of the metal strip S.

As shown in FIG. 1, the rolling device 1 includes a tension measuring unit 30 for measuring the tension (hereinafter also referred to as unwinding side tension) acting on the metal strip S between the unwinder 2 and a pair of rolling rolls 15, 16 (i.e., the upstream or entry side of the rolling mill 10). The tension measuring unit 30 may include a tension meter for detecting the tension acting on the metal strip S on the unwinder side. Alternatively, the tension measuring unit 30 may include a torque detector for detecting the load torque of the unwinder 2, and may be configured to calculate the tension based on the detection result of the load torque.

A signal indicating the result of detection of the speed of the metal strip S by the speed measuring unit 28, and a signal indicating the result of detection of the tension by the tension measuring unit 30 are sent to the control device 50.

FIG. 3 is a schematic diagram of a control device 50 according to one embodiment. As shown in FIG. 3, the control device 50 includes a rolling roll control unit 56 and an unwinder control unit 58. The control device 50 may further include a target speed acquisition unit 52 and/or a target tension acquisition unit 54.

The control device 50 includes a computer equipped with a processor (CPU, etc.), a main memory device (memory device; RAM, etc.), an auxiliary memory device, and an interface. The control device 50 receives signals indicating detection values from the speed measurement unit 28 and/or the tension measurement unit 30 via the interface. The processor is configured to process the signals received in this manner. The processor is also configured to process a program deployed in the main memory device. This realizes the functions of each of the functional units described above (target speed acquisition unit 52, target tension acquisition unit 54, rolling roll control unit 56, and/or unwinder control unit 58).

The processing contents in the control device 50 are implemented as a program executed by the processor. The program may be stored, for example, in an auxiliary storage device, or may be stored in a computer-readable recording medium. When the programs are executed, they are deployed in the main storage device. The processor reads the program from the main storage device and executes the instructions contained in the program.

The target speed acquisition unit 52 is configured to acquire the target speed of the metal strip S. The target speed may be set in advance according to the steel type and target thickness of the metal strip S to be rolled. The preset target speed may be stored in a memory unit (auxiliary storage device, etc.; not shown) of the control device 50. The target speed acquisition unit 52 may acquire the target speed of the metal strip S by reading the pre-stored target speed from the memory unit.

The target tension acquisition unit 54 is configured to acquire a target value (target tension) of the tension (unwinding side tension) of the metal strip S between the unwinder 2 and the pair of rolling rolls 15, 16. The target tension may be set in advance according to the steel type and target thickness of the metal strip S to be rolled. The preset target tension may be stored in a memory unit (auxiliary storage device, etc.; not shown) of the control device 50. The target tension acquisition unit 54 may acquire the target speed of the metal strip S by reading out the pre-stored target tension from the memory unit.

The rolling roll control unit 56 is configured to control the rotation of the pair of rolling rolls 15, 16 based on the deviation between the target speed of the metal strip S acquired by the target speed acquisition unit 52 and the measured speed (actual speed) of the metal strip S acquired by the speed measurement unit 28. The rolling roll control unit 56 may be configured to calculate a command value for the rotation speed of the motor 11 (the motor that drives the pair of rolling rolls 15, 16) such that the above-mentioned measured speed value approaches the target speed, and to adjust the rotation speed of the motor 11 based on the command value.

The unwinder control unit 58 is configured to control the torque of the unwinder 2 based on the deviation between the target tension of the metal strip S acquired by the target tension acquisition unit 54 and the measured value (actual tension) of the tension of the metal strip S acquired by the tension measurement unit 30. The unwinder control unit 58 may be configured to calculate a torque command value such that the measured value of the tension approaches the target tension, and to control the motor 26 that drives the unwinder 2 based on the command value.

(Method of operating the rolling mill)
Next, a method of operating the rolling mill 1 according to some embodiments will be described.

FIG. 4 is a flow chart of a method for operating a rolling apparatus according to one embodiment. The method for operating shown in FIG. 4 can be performed using the control device 50 described above. Also, some or all of the steps shown in FIG. 4 may be performed manually. FIG. 5 is a graph showing an example of the target speed and target tension of the metal strip S, and the change over time in the peripheral speed (outer peripheral speed) of the mandrel 4 of the unwinder 2 when performing the method for operating according to one embodiment. FIGS. 6 to 9 are schematic diagrams for explaining the change in shape of the tail end of the metal strip S when performing the method for operating according to one embodiment.

As shown in Figure 4, in an operating method according to one embodiment, the metal strip S is rolled by the rolling mill 10 while the metal strip S is unwound by the unwinder 2 (S2). In step S2, as shown in Figure 5, for example, rolling is performed with the target speed Vt* of the metal strip S set to Vt1 and the target tension T* on the unwinding side set to T1 (see Figure 5). During rolling of the metal strip S, the tension on the unwinding side is relatively large, so as shown in Figure 5, the speed of the metal strip S (≒Vt* = Vt1) and the peripheral speed Vm of the mandrel 4 of the unwinder 2 are approximately equal.

During rolling of the metal strip S, the control device 50 judges whether the first period has begun immediately before the tail end St of the metal strip S is released from the unwinder 2 (S4). The control device 50 may be configured to judge that the above-mentioned first period has begun, for example, when the remaining number of turns of the coil of the metal strip S in the unwinder 2 becomes equal to or less than a predetermined value. The above-mentioned first period may be a period in which the remaining number of turns of the metal strip S in the unwinder 2 is 2 or less, 1 or less, or 0.5 or less. The remaining number of turns of the metal strip S in the unwinder 2 can be calculated, for example, based on the number of turns or length of the metal strip S at the start of the rolling pass and/or the angular position of the gripper 22 around the rotation axis of the mandrel 4.

As a result of the judgment in step S4, while the first period has not yet begun (No in S4; until time t1 in FIG. 5), the target speed Vt* of the metal strip S is maintained at Vt1, and the target tension T* on the unwinding side is maintained at T1 while rolling the metal strip S continues (S2).

If the result of the determination in step S4 indicates that the first period has begun (Yes in S4, time t1 in Figure 5), the above-mentioned target speed Vt* is reduced so that the peripheral speed Vm of the mandrel 4 is greater than the speed (actual speed) of the metal strip S on the unwinding side, and/or the above-mentioned target tension T* is reduced (S6).

In the graph shown in FIG. 5, the first period is the period from time t1 when the remaining number of turns of the metal strip S on the mandrel 4 becomes equal to or less than a predetermined value (e.g., 0.5 turns or less) to time t6 when the tail end St of the metal strip S leaves the slot 24 of the unwinder 2. Also, in the example shown in FIG. 5, the target speed Vt* of the metal strip S is reduced from Vt1 to Vt2 during the period from time t1 to t3 in the first period, and the target tension T* on the unwinding side of the metal strip S is reduced from T1 to T2 during the period from time t2 (where t1<t2<t3) to time t4 (where t3<t4) in the first period.

In steps S2 and S6, the rotation of the pair of rolling rolls 15, 16 may be controlled based on the deviation between the target speed Vt* and the actual speed of the metal strip S. Also, in steps S2 and S6, the torque of the unwinder 2 may be controlled based on the deviation between the target tension T* and the actual tension of the metal strip between the unwinder 2 and the pair of rolling rolls 15, 16.

The phenomenon that occurs in step S6 will now be explained in more detail.

When the number of remaining turns of the metal strip S on the mandrel 4 is zero (see FIG. 6; between times t4 and t5 in FIG. 5) or when the number of remaining turns is zero or more (for example, the period before time t4 in FIG. 5), as shown in FIG. 6, the angle θ formed between the gripped portion 60 (tail end) inserted in the slot 24 and the adjacent portion 62 adjacent to the gripped portion 60 on the upper surface Sa side of the metal strip S is greater than 180 degrees, and the gripped portion 60 is bent downward (i.e., toward the lower surface Sb side of the metal strip S). Note that when the number of remaining turns is zero (see FIG. 6), the adjacent portion 62 of the metal strip S adjacent to the gripped portion 60 (tail end) approximately coincides with the tangent of the mandrel 4.

Generally, when the target speed Vt* of the metal strip S is reduced, the circumferential speed Vm of the mandrel 4 also decreases, but if the rate of change of the target speed Vt* of the metal strip S is increased to a certain extent in the first period (i.e., when the target speed Vt* is suddenly decreased; step S6 above), the inertia of the mandrel 4 causes the rate of decrease in the mandrel's circumferential speed to be smaller than the rate of decrease in the speed of the metal strip S, resulting in a period in which the circumferential speed Vm of the mandrel 4 is greater than the speed (actual speed) of the metal strip S (the period from time t1 to t3 in Figure 5). This makes it possible to loosen the tension (actual tension) on the unwinding side of the metal strip S.

Alternatively, by decreasing the target tension T* on the unwinding side of the metal strip S during the first period (step S6 described above), the tension (actual tension) on the unwinding side of the metal strip S can be loosened.

In this way, as a result of the tension (actual tension) on the unwinding side of the metal strip S being relaxed, even if the angular position of the mandrel 4 exceeds the angular position where the remaining number of turns of the metal strip S on the mandrel 4 becomes zero (see FIG. 6; a time between times t4 and t5 in FIG. 5) and the angular position where the opening of the slot 24 of the mandrel 4 and the gripper 22 are located at the top of the mandrel 4 (see FIG. 7; time t5 in FIG. 5), the tension acting on the metal strip S is smaller than the gripping force of the gripper 22 (gripping portion), so the gripped portion 60 (tail end) of the metal strip S remains in a state where it does not come out of the slot 24.

Then, the mandrel 4 rotates further until the angle θ formed between the gripped portion 60 and the adjacent portion 62 is smaller than 180 degrees and the gripped portion 60 is bent upward (i.e., toward the upper surface Sa of the metal strip S) (see FIG. 8), at which point the gripped portion 60 (tail end) of the metal strip S comes out of the slot 24 (S8 in FIG. 4; time t6 in FIG. 5; FIG. 9).

In a typical conventional operating method, the tension on the unwinding side of the metal strip S is not relaxed from the time the metal strip S is being rolled until the tail end is released from the unwinding machine. As a result, near the opening of the slot 24 of the mandrel 4 and the angular position where the gripper 22 is located at the top of the mandrel 4 (see Figure 7), the tension acting on the metal strip S becomes greater than the gripping force of the gripper 22 (gripping portion), and the gripped portion 60 (tail end portion) of the metal strip S comes out of the slot 24.

At this time, the angle θ formed between the gripped portion 60 and the adjacent portion 62 is close to 180 degrees, which is smaller than the angle θ (more than 180 degrees) when the remaining number of turns of the metal strip S is zero or more. However, even if the downward bending deformation (plastic deformation) formed in the gripped portion 60 when the remaining number of turns of the metal strip S is zero or more is corrected to a straight line for an instant, this is an elastic deformation, and most of the downward bending of the gripped portion 60 remains, as shown in Figure 10. Note that Figure 10 is a schematic diagram for explaining the change in shape of the tail end of the metal strip due to a typical operating method.

In this regard, according to the above-mentioned embodiment, in the first period immediately before the tail end St of the metal strip S leaves the unwinder, the target speed Vt* of the metal strip is reduced so that the peripheral speed Vm of the mandrel 4 is greater than the actual speed of the metal strip S, or the target tension T* is reduced, so that the actual tension of the metal strip S can be relaxed. Therefore, the tail end of the metal strip S is more likely to come off the mandrel 4 (unwinder) 2 at a position (for example, the position shown in FIG. 8) where the tail end (gripped portion 60) is folded in the opposite direction (i.e., upward) from the position during unwinding. As a result, the downward bent shape (plastic deformation) formed at the tail end by the gripping portion during unwinding is folded back to the opposite direction when it leaves the mandrel 4, so that the downward bending deformation (plastic deformation) of the tail end described above can be mitigated. As a result, when rolling of the next pass begins, the leading end of the metal strip S is less likely to get caught in the conveying path, and smooth passing is possible. This enables more efficient production of products.

In the above-mentioned step S6, during the above-mentioned first period, the above-mentioned target speed Vt* may be reduced so that the peripheral speed Vm of the mandrel 4 is greater than the speed (actual speed) of the metal strip S on the unwinding side, and the above-mentioned target tension T* may also be reduced.

In the example shown in FIG. 5, during the first period (t1 to t6) described above, from time t1 to t3, the target speed Vt* described above is reduced so that the peripheral speed Vm of the mandrel 4 is greater than the speed (actual speed) of the metal strip S on the unwinding side, and from time t2 to t4, the target tension T* described above is reduced.

In this way, during the first period immediately before the tail end of the metal strip S leaves the unwinder 2, the target speed Vt* of the metal strip S is reduced so that the peripheral speed Vm of the mandrel 4 is greater than the speed of the metal strip S, and the target tension T* is reduced, so that the tension of the metal strip S can be more reliably relaxed. This makes it easier for the downward bent shape (plastic deformation) formed at the tail end at the gripping section during unwinding to be folded back to the opposite side when it leaves the mandrel 4, so that the downward bent deformation (plastic deformation) of the tail end described above can be more reliably alleviated. Therefore, when rolling for the next pass begins, the tip end of the metal strip S is less likely to get caught on the conveying path, allowing for smooth sheet threading.

Alternatively, in the above-mentioned step S6, during the above-mentioned first period, the above-mentioned target tension T* is reduced while the target speed Vt* is reduced so that the peripheral speed of the mandrel 4 becomes greater than the speed (actual speed) of the metal strip S on the unwinding side.

In the example shown in FIG. 5, during the first period (t1 to t6) described above, between times t2 and t3, the target tension T* described above is reduced while the target speed Vt* described above is reduced so that the peripheral speed Vm of the mandrel 4 becomes greater than the speed (actual speed) of the metal strip S on the unwinding side.

In this way, by reducing the target tension T* while reducing the target speed Vt* of the metal strip S so that the peripheral speed Vm of the mandrel 4 becomes greater than the speed of the metal strip S during the first period immediately before the tail end of the metal strip S leaves the unwinder 2, the tension of the metal strip S can be more reliably relaxed. This makes it easier for the downward bent shape (plastic deformation) formed at the tail end at the gripping section during unwinding to be folded back to the opposite side when it leaves the mandrel 4, so that the downward bending deformation (plastic deformation) of the tail end described above can be more reliably alleviated. Therefore, when rolling for the next pass begins, the tip end of the metal strip S is less likely to get caught on the conveying path, allowing for smooth sheet threading.

FIG. 11 is a flowchart of a method for operating a rolling device according to one embodiment. Some or all of the steps shown in FIG. 11 can be performed using the control device 50 described above or manually.

As shown in FIG. 4, in one embodiment of the operating method, the metal strip S is rolled by the rolling mill 10 while the metal strip S is unwound by the unwinder 2 (S12) while the angle θ (see FIG. 6) formed on the upper surface Sa side of the metal strip S between the gripped portion 60 (tail end) inserted in the slot 24 and the adjacent portion 62 adjacent to the gripped portion 60 (or the folding angle made between a straight line along the adjacent portion and a straight line along the gripped portion in the direction of rotation of the mandrel, based on a straight line along the adjacent portion) is 180 degrees or more (No in S14; i.e., for example, as shown in FIG. 7, until the above-mentioned angle θ becomes 180 degrees).

Then, when the metal strip S has finished being unwound from the unwinding machine 2 and the angle θ described above becomes smaller than 180 degrees (Yes in S14; see, for example, FIG. 8), the tail end St of the metal strip S is detached from the unwinding machine 2 (S16).

According to the above-mentioned embodiment, when the metal strip S is wound around the unwinder 2, the angle θ formed between the gripped portion 60 (tail end) and the adjacent portion 62 on the upper surface Sa side of the metal strip S is 180 degrees or more (i.e., the tail end of the metal strip is bent downward), and the tail end of the metal strip S is released from the unwinder 2 after the angle θ becomes smaller than 180 degrees at the end of unwinding the metal strip S from the unwinder 2 (i.e., the tail end of the metal strip S is bent upward). As a result, the downward bent shape (plastic deformation) formed at the tail end at the gripper during unwinding is folded back to the opposite side when it leaves the mandrel 4, so that the downward bending deformation (plastic deformation) of the tail end can be mitigated. As a result, when rolling of the next pass begins, the tip of the metal strip S is less likely to get caught in the conveying path, making it possible to pass the plate smoothly. This enables more efficient production of products.

The contents described in each of the above embodiments can be understood, for example, as follows:

[1] At least one embodiment of the present invention relates to a control device for a rolling mill, comprising:
A control device for controlling a rolling apparatus (1) including a pair of rolling rolls (15, 16) for rolling a metal strip (S) and an unwinder (2) including a mandrel (4) having a gripping portion (e.g., the above-mentioned gripper 22) for gripping a tail end of the metal strip and for unwinding the metal strip toward the pair of rolling rolls,
a roll control unit (56) configured to control the rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinder control unit (58) configured to control a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
The method is configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinding machine.

According to the configuration of [1] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the speed of the metal strip is reduced so that the peripheral speed of the mandrel is greater than the speed of the metal strip, or the target value of the tension is reduced, so that the tension of the metal strip can be relaxed. Therefore, the tail end of the metal strip (gripped portion) is easily removed from the mandrel (unwinder) at a position where it is bent in the opposite direction from when it is unwound. As a result, the downward bent shape (plastic deformation) formed in the tail end at the gripping portion during unwinding is folded back to the opposite direction when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be mitigated. As a result, when rolling of the next pass begins, the tip end of the metal strip is less likely to get caught in the conveying path, making it possible to pass the strip smoothly. This enables more efficient production of products.

[2] In some embodiments, in the configuration of [1] above,
The control device for the rolling device includes:
During the first period, the target speed is reduced so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side, and the target tension is reduced.

According to the configuration of [2] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the speed of the metal strip is reduced so that the peripheral speed of the mandrel is greater than the speed of the metal strip, and the target value of the tension is also reduced, so that the tension of the metal strip can be more reliably relaxed. As a result, the downward bent shape (plastic deformation) formed at the tail end by the gripping section during unwinding is more likely to be folded back to the opposite side when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be more reliably alleviated. Therefore, when rolling for the next pass begins, the tip end of the metal strip is less likely to get caught on the conveying path, allowing for smooth sheet threading.

[3] In some embodiments, in the configuration of [2] above,
The control device for the rolling device includes:
During the first period, the target tension is decreased while the target speed is decreased so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side.

According to the configuration of [3] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the metal strip speed is reduced while the target value of the tension is reduced so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip, so that the tension of the metal strip can be more reliably relaxed. As a result, the downward bent shape (plastic deformation) formed at the tail end by the gripping section during unwinding is more likely to be folded back to the opposite side when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be more reliably alleviated. Therefore, when rolling for the next pass begins, the leading end of the metal strip is less likely to get caught on the conveying path, allowing for smooth sheet threading.

[4] In some embodiments, in any one of the configurations [1] to [3] above,
The first period is a period during which the number of turns remaining of the metal strip on the unwinder is two or less.

According to the configuration [4] above, during the first period when the number of remaining turns of the metal strip in the unwinder is two or less (i.e., the first period immediately before the tail end of the metal strip leaves the unwinder), the target value of the speed or the target value of the tension of the metal strip is reduced to relax the tension of the metal strip, so that the tension acting on the metal strip is maintained until immediately before the tail end leaves the unwinder (i.e., before the first period). This results in a good yield.

[5] At least one embodiment of the rolling device (1) of the present invention comprises:
A pair of rolling rolls (15, 16) for rolling the metal strip (S);
an unwinder (2) for unwinding the metal strip toward the pair of rolling rolls, the unwinder (2) including a mandrel (4) having a gripping portion (e.g., the gripper 22 described above) for gripping the tail end of the metal strip;
A control device (50) according to any one of the above [1] to [4] configured to control the pair of rolling rolls and the unwinder;
Equipped with.

According to the configuration of [5] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the speed of the metal strip is reduced so that the peripheral speed of the mandrel is greater than the speed of the metal strip, or the target value of the tension is reduced, so that the tension of the metal strip can be relaxed. Therefore, the tail end of the metal strip (gripped portion) is easily removed from the mandrel (unwinder) at a position where it is bent in the opposite direction from when it is unwound. As a result, the downward bent shape (plastic deformation) formed in the tail end at the gripping portion during unwinding is folded back to the opposite direction when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be mitigated. As a result, when rolling of the next pass begins, the leading end of the metal strip is less likely to get caught in the conveying path, making it possible to pass the strip smoothly. This enables more efficient production of products.

[6] At least one embodiment of the rolling device (1) of the present invention comprises:
A pair of rolling rolls (15, 16) for rolling the metal strip (S);
an unwinder (2) for unwinding the metal strip toward the pair of rolling rolls, the unwinder (2) including a mandrel (4) having a gripping portion (e.g., the gripper 22 described above) for gripping the tail end of the metal strip;
Equipped with
The metal strip includes a gripped portion (60) gripped by the gripping portion, and an adjacent portion (62) adjacent to the gripped portion in the longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle (θ) formed between the gripped portion and the adjacent portion on the upper surface (Sa) side of the metal strip (or a folding angle (θ) formed between a straight line along the gripped portion and a straight line along the adjacent portion in the direction of rotation of the mandrel, with a straight line along the gripped portion as a reference) is 180 degrees or more,
The tail end of the metal strip is configured to separate from the unwinder when the angle becomes smaller than 180 degrees at the end of unwinding of the metal strip from the unwinder.

According to the configuration of [6] above, when the metal strip is wound around the unwinder, the angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip (or the folding angle formed between the straight line along the gripping portion and the straight line along the adjacent portion in the direction of rotation of the mandrel) is 180 degrees or more (i.e., the tail end of the metal strip is bent downward), and the tail end of the metal strip leaves the unwinder after the above-mentioned angle becomes smaller than 180 degrees at the end of unwinding from the unwinder (i.e., the tail end of the metal strip is bent upward). As a result, the downward bent shape (plastic deformation) formed at the tail end at the gripping portion during unwinding is folded back to the opposite side when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end can be mitigated. As a result, when rolling of the next pass begins, the tip of the metal strip is less likely to get caught in the conveying path, making it possible to pass the strip smoothly. This enables more efficient production of products.

[7] A method for operating a rolling mill according to at least one embodiment of the present invention includes the steps of:
A method for operating a rolling apparatus (1) including a pair of rolling rolls (15, 16) for rolling a metal strip (S) and an unwinder (2) including a mandrel (4) having a gripping portion (e.g., the above-mentioned gripper 22) for gripping a tail end of the metal strip and for unwinding the metal strip toward the pair of rolling rolls, comprising the steps of:
a roll control step (S2, S6) of controlling the rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinding mechanism step (S2, S6) configured to control the torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
During a first period immediately before the tail end of the metal strip separates from the unwinder, the target speed is reduced so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side, or the target tension is reduced (S6).

According to the method of [7] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the speed of the metal strip is reduced so that the peripheral speed of the mandrel is greater than the speed of the metal strip, or the target value of the tension is reduced, so that the tension of the metal strip can be relaxed. Therefore, the tail end of the metal strip (gripped portion) is easily removed from the mandrel (unwinder) at a position where it is bent in the opposite direction from when it is unwound. As a result, the downward bent shape (plastic deformation) formed in the tail end at the gripping portion during unwinding is folded back to the opposite direction when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be mitigated. As a result, when rolling of the next pass begins, the leading end of the metal strip is less likely to get caught in the conveying path, making it possible to pass the strip smoothly. This enables more efficient production of products.

[8] A method for operating a rolling mill according to at least one embodiment of the present invention includes the steps of:
A method for operating a rolling apparatus (1) including a pair of rolling rolls (15, 16) for rolling a metal strip (S) and an unwinder (2) including a mandrel (4) having a gripping portion (e.g., the above-mentioned gripper 22) for gripping a tail end of the metal strip and for unwinding the metal strip toward the pair of rolling rolls, comprising the steps of:
The metal strip includes a gripped portion (60) gripped by the gripping portion, and an adjacent portion (62) adjacent to the gripped portion in the longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle (θ) formed between the gripped portion and the adjacent portion on the upper surface (Sa) side of the metal strip (or a folding angle (θ) formed between a straight line along the gripped portion and a straight line along the adjacent portion in the direction of rotation of the mandrel, with a straight line along the gripped portion as a reference) is 180 degrees or more,
a step (S16) of separating the tail end of the metal strip from the unwinder when the angle becomes smaller than 180 degrees at the end of unwinding of the metal strip from the unwinder;
Equipped with.

According to the method of [8] above, when the metal strip is wound around the unwinder, the angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip (or the folding angle formed between the straight line along the gripping portion and the straight line along the adjacent portion in the direction of rotation of the mandrel) is 180 degrees or more (i.e., the tail end of the metal strip is bent downward), and the tail end of the metal strip leaves the unwinder after the above-mentioned angle becomes smaller than 180 degrees at the end of unwinding from the unwinder (i.e., the tail end of the metal strip is bent upward). As a result, the downward bent shape (plastic deformation) formed at the tail end at the gripping portion during unwinding is folded back to the opposite side when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end can be mitigated. As a result, when rolling of the next pass begins, the leading end of the metal strip is less likely to get caught in the conveying path, allowing for smooth passing. This allows for more efficient production of products.

[9] A control program for a rolling apparatus according to at least one embodiment of the present invention,
A program for controlling a rolling apparatus (1) including a pair of rolling rolls (15, 16) for rolling a metal strip (S) and an unwinder (2) including a mandrel (4) having a gripping portion (e.g., the above-mentioned gripper 22) for gripping a tail end of the metal strip and for unwinding the metal strip toward the pair of rolling rolls, the program comprising:
On the computer,
a step of controlling the rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
controlling a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
configured to execute
The method is configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinding machine.

According to the program of [9] above, in the first period immediately before the tail end of the metal strip leaves the unwinder, the target value of the speed of the metal strip is reduced so that the peripheral speed of the mandrel is greater than the speed of the metal strip, or the target value of the tension is reduced, so that the tension of the metal strip can be relaxed. Therefore, the tail end of the metal strip (gripped part) is easily removed from the mandrel (unwinder) at a position where it is bent in the opposite direction from when it is unwound. As a result, the downward bent shape (plastic deformation) formed in the tail end at the gripping part during unwinding is folded back to the opposite direction when it leaves the mandrel, so that the downward bending deformation (plastic deformation) of the tail end described above can be mitigated. As a result, when rolling of the next pass begins, the tip end of the metal strip is less likely to get caught in the conveying path, making it possible to pass the strip smoothly. This enables more efficient production of products.

The above describes an embodiment of the present invention, but the present invention is not limited to the above-described embodiment, and also includes modifications to the above-described embodiment and appropriate combinations of these embodiments.

In this specification, expressions expressing relative or absolute configuration, such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""center,""concentric," or "coaxial," do not only strictly represent such a configuration, but also represent a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained.
For example, expressions indicating that things are in an equal state, such as "identical,""equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained.
Furthermore, in this specification, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained.
In addition, in this specification, the expressions "comprise,""include," or "have" a certain element are not exclusive expressions that exclude the presence of other elements.

REFERENCE SIGNS LIST 1 Rolling machine 2 Unwinder 3 Winder 4 Mandrel 5 Mandrel 6 Guide roll 7 Guide roll 10 Rolling machine 11 Motor 15 Rolling roll 16 Rolling roll 17 Intermediate roll 18 Intermediate roll 19 Backup roll 20 Backup roll 22 Gripper 23 Gripper 24 Slot 26 Motor 28 Speed measurement unit 30 Tension measurement unit 50 Control device 52 Target speed acquisition unit 54 Target tension acquisition unit 56 Rolling roll control unit 58 Unwinder control unit 60 Gripped part 62 Adjacent part S Metal strip Sa Upper surface Sb Lower surface St Tail end θ Angle

Claims (9)

A control device for controlling a rolling apparatus including a pair of rolling rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end portion of the metal strip, and for unwinding the metal strip toward the pair of rolling rolls,
a roll control unit configured to control rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinder control unit configured to control a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
A control device for a rolling apparatus configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinder. 2. The control device for a rolling apparatus according to claim 1, configured to reduce the target speed and reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during the first period. 3. The control device for a rolling apparatus according to claim 2, configured to reduce the target tension while reducing the target speed during the first period so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side. The control device for a rolling mill according to any one of claims 1 to 3, wherein the first period is a period during which the number of remaining turns of the metal strip in the unwinder is two or less. A pair of rolls for rolling the metal strip;
an unwinder for unwinding the metal strip toward the pair of rolling rolls, the unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip;
A control device according to any one of claims 1 to 3, configured to control the pair of rolling rolls and the unwinder;
A rolling device comprising: A pair of rolls for rolling the metal strip;
an unwinder for unwinding the metal strip toward the pair of rolling rolls, the unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip;
Equipped with
The metal strip includes a gripped portion gripped by the gripping portion and an adjacent portion adjacent to the gripped portion in a longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip is 180 degrees or more;
a rolling device configured so that the tail end of the metal strip separates from the unwinder when the angle becomes less than 180 degrees at the end of unwinding of the metal strip from the unwinder. A method for operating a rolling mill including a pair of rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip, and unwinding the metal strip toward the pair of rolls, comprising the steps of:
a roll control step of controlling rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
an unwinding mechanism step configured to control a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
Equipped with
A method for operating a rolling mill, comprising the steps of: reducing the target speed or reducing the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinder. A method for operating a rolling mill including a pair of rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end of the metal strip, and unwinding the metal strip toward the pair of rolls, comprising the steps of:
The metal strip includes a gripped portion gripped by the gripping portion and an adjacent portion adjacent to the gripped portion in a longitudinal direction of the metal strip,
When the metal strip is wound around the unwinder, an angle formed between the gripped portion and the adjacent portion on the upper surface side of the metal strip is 180 degrees or more;
a step of separating the tail end of the metal strip from the unwinder when the angle becomes smaller than 180 degrees at the end of unwinding of the metal strip from the unwinder. A program for controlling a rolling apparatus including a pair of rolling rolls for rolling a metal strip, and an unwinder including a mandrel having a gripping portion for gripping a tail end portion of the metal strip and for unwinding the metal strip toward the pair of rolling rolls,
On the computer,
a step of controlling the rotation of the pair of rolls based on a deviation between a target speed and an actual speed of the metal strip;
controlling a torque of the unwinder based on a deviation between a target tension and an actual tension of the metal strip between the unwinder and the pair of rolling rolls;
configured to execute
A control program for a rolling apparatus configured to reduce the target speed or reduce the target tension so that the peripheral speed of the mandrel becomes greater than the speed of the metal strip at the unwinding side during a first period immediately before the tail end of the metal strip separates from the unwinder.

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