Paper winding device and paper winding method

Description

[Technical field]

[0001] The present disclosure relates to a paper winding device. [Background technology]

[0002] Patent Document 1 discloses a technique for continuously winding a web, which is a strip-shaped sheet-like material such as paper or film, around a plurality of winding rolls. In this conventional technique, the web is cut when the winding roll around which the web is to be wound is replaced. Specifically, the web is cut in a state where the web is in contact with the outer peripheral surface of the winding core around which the web is to be newly wound. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-048173 Summary of the Invention [Problem to be solved by the invention]

[0004] When paper is continuously wound around multiple winding cores, a traverse cutter may be used to cut the paper when replacing the winding roll after the winding of the paper around the winding cores is complete. When cutting the paper with the traverse cutter, a situation occurs in which both the winding roll and the new winding core onto which the paper is to be wound are winding the paper.

[0005] In this case, if the new core is not in an appropriate operating state for winding up the paper when the paper is cut by the traverse cutter, the paper being wound onto the new core may become wrinkled or may become distorted.

[0006] One object of the present disclosure is to provide a technique that can improve the stability of winding paper onto a new winding core when replacing a winding roll. [Means for solving the problem]

[0007] A first aspect of the present disclosure relates to a paper winding device that winds up paper. The paper winding device includes a first winding core on which paper is to be wound, which is provided on a first arm that rotates around a rotation axis, a first motor that drives the first winding core, a second winding core on which paper is to be wound next to the first winding core, which is provided on a second arm that rotates around a rotation axis, a second motor that drives the second winding core, and a control device that controls the rotation of the first motor and the second motor. In the rotation control, when the torque value of the second motor is equal to or greater than a reference torque value during the operation of a traverse cutter that cuts paper near the second winding core after the first winding core has been wound and the second arm has been rotated to a position where the paper is to be wound, the control device switches the control mode of the second motor from speed control to torque control and performs tension correction control that adjusts the torque value of the second motor so that the tension of the paper is within a target range. The torque reference value is the torque value of the first motor when the tension of the paper during winding of the paper around the first winding core is within a target range.

[0008] A second aspect of the present disclosure is This relates to a paper winding device that winds up paper. The paper winding device includes a first winding core on which paper is to be wound, which is provided on a first arm that rotates around a rotation axis, a first motor that drives the first winding core, a second winding core on which paper is to be wound next after the first winding core, which is provided on a second arm that rotates around a rotation axis, a second motor that drives the second winding core, and a control device that controls the rotation of the first motor and the second motor. In the rotation control, when the torque value of the second motor is equal to or greater than a reference torque value during the operation of a traverse cutter that cuts the paper near the second winding core after the first winding core has been wound and the second arm has been rotated to a position where the paper is to be wound, the control device switches the control mode of the second motor from speed control to torque control and performs tension correction control that adjusts the torque value of the second motor so that the tension of the paper is within a target range. The reference torque value is a value obtained by adding at least the mechanical loss of the second motor to the torque value of the first motor.

[0009] A third aspect of the present disclosure has the following features in addition to those of the second aspect. The mechanical losses are periodically updated while the second motor is running.

[0010] A fourth aspect of the present disclosure is In addition to the first or second aspect, the present invention further has the following feature: In the rotation control, the control device further sets the control mode of the first motor so as to stop driving the first motor after switching the control mode of the second motor from the speed control to the torque control and after the operation of the traverse cutter is completed.

[0011] A fifth aspect of the present disclosure is This relates to a paper winding method for winding paper. The paper winding method includes the steps of: determining whether or not the torque value of a second motor driving the second winding core is equal to or greater than a reference torque value during operation of a traverse cutter for cutting paper near the second winding core after completion of winding of paper by a first winding core mounted on a first arm rotating about a rotation axis and after a second winding core mounted on a second arm rotating about a rotation axis and onto which paper is to be wound next after the first winding core has reached a position where the paper should be wound; switching the control mode of the second motor from speed control to torque control when it is determined that the torque value of the second motor is equal to or greater than the reference torque value; and performing tension correction control for adjusting the torque value of the second motor so that the tension of the paper is within a target range. The reference torque value is the torque value of the first motor driving the first winding core when the tension of the paper is within the target range during winding of the paper onto the first winding core.

[0012] A sixth aspect of the present disclosure relates to a paper winding method for winding paper, the paper winding method including, during operation of a traverse cutter for cutting paper near the second winding core after completion of winding of paper by a first winding core provided on a first arm rotating about a rotation axis and after a second winding core provided on a second arm rotating about a rotation axis and onto which paper is to be wound next after the first winding core has been positioned, determining whether or not a torque value of a second motor for driving the second winding core is equal to or greater than a reference torque value, and switching a control mode of the second motor from speed control to torque control when it is determined that the torque value of the second motor is equal to or greater than the reference torque value, and performing tension correction control for adjusting the torque value of the second motor so that the tension of the paper is within a target range. The torque reference value is further a value obtained by adding at least a mechanical loss of the second motor to the torque value of the first motor that drives the first winding core. Effect of the Invention

[0013] According to the present disclosure, when the torque value of the second motor is equal to or greater than the reference torque value during the operation of the traverse cutter that cuts the paper, the control mode of the second motor is switched from speed control to torque control, and tension correction control is performed to adjust the torque value of the second motor so that the tension of the paper falls within a target range. This improves the stability of paper winding onto a new winding core when replacing a winding roll. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram for explaining an overview of a paper winding device according to an embodiment; [Diagram 2] 1 is a diagram for explaining an overview of a paper winding device according to an embodiment; [Diagram 3] 1A to 1C are diagrams for explaining specific examples of a paper winding device according to an embodiment. [Figure 4] 1A to 1C are diagrams for explaining specific examples of a paper winding device according to an embodiment. [Diagram 5] 4 is a flowchart showing an example of processing of the paper winding device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A paper winding device and a paper winding method according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. In addition, common elements in each drawing are given the same reference numerals and duplicated explanations will be omitted.

[0016] 1. Overview 1-1. Configuration of the paper winding device

[0017] FIG. 1 is a diagram for explaining an overview of a paper winding device 1 according to an embodiment. The paper winding device 1 is a turret-type device that continuously winds up paper 50 around multiple winding cores. The paper 50 is, for example, thick paper having a thickness of 800 μm or the like. The paper winding device 1 includes a paper winding mechanism 2, a paper cutting unit 3, and a control device 100.

[0018] The paper winding mechanism 2 includes an arm unit 10 (first arm 10a, second arm 10b, third arm 10c, and fourth arm 10d). Each arm has a mechanism for rotating in at least one direction around a rotation shaft 10e provided at one end of the arm. These arms may have a cross-shaped structure as shown in FIG. 1(A).

[0019] Each arm repeatedly rotates a predetermined angle at a predetermined timing after the start of operation of the paper winding device 1. Alternatively, each arm rotates a predetermined angle upon receiving a rotation instruction from the control device 100, which will be described later.

[0020] The other end of the first arm 10a is provided with a first winding core 11. The other end of the second arm 10b is provided with a second winding core 12. The other end of the third arm 10c is provided with a guide roller 13. And the other end of the fourth arm 10d is provided with a guide roller 14.

[0021] The first winding core 11 is a winding core around which the paper 50 is to be wound. The second winding core 12 is a winding core around which the paper 50 is to be wound next to the first winding core 11. The second winding core 12 is located on the opposite side of the first winding core 11 across the rotation axis 10e, as shown in FIG. 1(A), for example. When the position of either the first winding core 11 or the second winding core 12 is the position at which the paper 50 is to be wound, the paper 50 is wound by that winding core. The position at which the paper 50 is to be wound is, for example, the position of the first winding core 11 shown in FIG. 1(A).

[0022] The guide roller 14 guides the paper 50 being wound onto the first winding core 11 after the first winding core 11 has completed winding the paper 50 and during the period from when the second arm 10b pivots to place the second winding core 12 in a position to wind up the paper 50 until the paper 50 is cut. Although not shown in the figure, the guide roller 13 guides the paper 50 being wound onto the second winding core 12 after the second winding core 12 has completed winding the paper 50 and during the period from when the first arm 10a pivots to place the first winding core 11 in a position to wind up the paper 50 again until the paper 50 is cut.

[0023] The paper winding mechanism 2 further includes a first motor 21 and a second motor 22. The first motor 21 is a motor that drives the first winding core 11 and is fixedly attached to the first winding core 11. The second motor 22 is a motor that drives the second winding core 12 and is fixedly attached to the second winding core 12. The first motor 21 and the second motor 22 start or stop driving in response to a command from the control device 100, which will be described later.

[0024] When the position of either the first winding core 11 or the second winding core 12 is the position where the paper 50 should be wound, the motor corresponding to that winding core is driven to wind the paper 50 onto that winding core.

[0025] The paper cutting unit 3 includes a first touch arm 30 and a second touch arm 40. The first touch arm 30 is a mechanical device for pressing the paper 50 against the outer peripheral surface of the second winding core 12 when the paper 50 is cut so that the second winding core 12 can wind up the cut paper 50.

[0026] The first touch arm 30 has a mechanism for rotating around a rotation shaft 30a provided at one end of the first touch arm 30. Here, the action of the first touch arm 30 rotating in a clockwise direction from the viewpoint of Fig. 1 is referred to as moving forward, and the action of the first touch arm 30 rotating in a counterclockwise direction from the viewpoint of Fig. 1 is referred to as moving backward. The first touch arm 30 moves forward before the paper 50 is cut, and moves backward after the paper 50 is cut.

[0027] 1B, the first touch arm 30 advances at the same time as the operation of the paper winding mechanism 2 is completed. Also, the first touch arm 30 retreats at the same time as cutting of the paper 50 by the traverse cutter 40c, which will be described later, is completed.

[0028] When the first touch arm 30 advances, the nip roll 30b provided at the other end of the first touch arm 30 presses the paper 50 against the outer circumferential surface of the second winding core 12. This allows the second winding core 12 to wind up the cut paper 50.

[0029] The second touch arm 40 is a mechanical device that cuts the paper 50. The second touch arm 40 has a mechanism that rotates around a rotation shaft 40a provided at one end of the second touch arm 40. The action of the second touch arm 40 rotating counterclockwise from the viewpoint of Fig. 1 is referred to as moving forward, and the action of the second touch arm 40 rotating clockwise from the viewpoint of Fig. 1 is referred to as moving backward. The second touch arm 40 moves forward before cutting the paper 50 and moves backward after cutting the paper 50.

[0030] 1B, the second touch arm 40 advances at the same time as the operation of the paper winding mechanism 2 is completed. Also, the second touch arm 40 retreats at the same time as cutting of the paper 50 by the traverse cutter 40c, which will be described later, is completed.

[0031] The second touch arm 40 has a core fixing device 40b into which the second core 12 provided at the other end of the second touch arm 40 can be fitted and fixed, and when the paper 50 is cut, the second core 12 is fixed by the core fixing device 40b.

[0032] The second touch arm 40 has a traverse cutter 40c provided between one end of the second touch arm 40 and the other end of the second touch arm 40. The traverse cutter 40c is a cutter that cuts the paper 50. The traverse cutter 40c is stored in the second touch arm 40 except when the paper 50 is being cut, and is used only when the paper 50 is being cut. An image of the traverse cutter 40c in use is shown, for example, as in FIG. 1(B).

[0033] The traverse cutter 40c cuts the paper 50 near the second winding core 12 after the second winding core 12 has reached a position where the paper 50 should be wound. The position where the paper 50 is cut is, for example, as shown in Fig. 1(B), between one end (rotating shaft 40a) of the second touch arm 40 and the other end (winding core fixing device 40b) of the second touch arm 40, and is a position near the second winding core 12. An overview of the method of cutting the paper 50 by the traverse cutter 40c will be described later.

[0034] The control device 100 is a controller that controls the rotation of the first motor 21 and the second motor 22. The controller is, for example, a PLC (Programmable Logic Controller). The control device 100 also includes a driver that drives the first motor 21 and the second motor 22. Furthermore, the control device 100 stores a paper winding program (not shown). The control device 100 executes the paper winding program to realize the function of controlling the rotation of the first motor 21 and the second motor 22.

[0035] The control device 100 is connected to the first motor 21, the second motor 22, the arm portion 10, the first touch arm 30, and the second touch arm 40. The control device 100 and each device are connected by, for example, a cable.

[0036] The control device 100 receives at least a rotation start flag of the second arm 10b from the arm section 10. The control device 100 also receives at least a forward movement start flag of the first touch arm 30 from the first touch arm 30. Furthermore, the control device 100 receives at least a backward movement start flag of the second touch arm 40 from the second touch arm 40. Details of the rotation control of the first motor 21 and the second motor 22 by the control device 100 will be described later.

[0037] 1-2. Example of traverse cutter operation Fig. 2 is a diagram for explaining an overview of a cutting method of the traverse cutter 40c in the paper winding device 1 according to the embodiment. Specifically, Fig. 2 shows a time series of an example of the operation of the traverse cutter 40c that cuts the paper 50 near the second winding core 12 after the first winding core 11 has completed winding the paper 50 and after the second arm 10b has turned to bring the second winding core 12 to a position where the paper 50 should be wound.

[0038] 2, the traverse cutter 40c cuts the paper 50 in a direction (cutting direction) perpendicular to the longitudinal direction of the paper 50 while the nip roll 30b presses the paper 50 against the outer circumferential surface of the second winding core 12. Because the cutting speed of the traverse cutter 40c is matched to the winding speed of the paper 50, the paper 50 wound around the first winding core 11 is cut at an angle of 45 degrees to the winding direction by the traverse cutter 40c.

[0039] The traverse cutter 40c has a movable range 60 in the cutting direction. As shown in Fig. 2, the traverse cutter 40c cuts the paper 50 according to the movable range 60. When the width of the paper 50 is W [m] and the speed of the paper 50 being wound around the first winding core 11 is V [m / min], the cutting time of the traverse cutter 40c is expressed by the following formula (1).

[0040]

number

[0041] For example, when the width of the paper 50 is 2.01 [m] and the speed of the paper 50 is 20 [m / min], the cutting time of the traverse cutter 40c is 6.03 [s].

[0042] After the paper 50 is cut by the traverse cutter 40c, each of the two separated pieces of paper 50 is wound onto the first winding core 11 and the second winding core 12, respectively. This makes it possible to replace the winding roll after winding of the paper 50 onto the first winding core 11 is completed while the paper winding device 1 is operating continuously.

[0043] 2. Specific examples 2-1. Motor rotation control example Fig. 3 is a diagram for explaining a specific example of the paper winding device 1 according to the embodiment. Specifically, Fig. 3 shows an example of rotation control of the first motor 21 and the second motor 22 in the control device 100 of the paper winding device 1. Note that the processing of the portion shown in Fig. 3(A) is performed by a chain of mechanical operations, and is not controlled by the control device 100. Based on this, an example of rotation control of the first motor 21 and the second motor 22 by the control device 100 will be described below.

[0044] The control device 100 receives, from the arm unit 10, a flag indicating that the second arm 10b should start turning after the first winding core 11 has completed winding the paper 50, at the timing shown in FIG. 3(B).

[0045] Then, the control device 100 sets the control mode of the second motor 22 so as to drive the second motor 22. Specifically, the control device 100 sets the control mode of the second motor 22 to speed control. Speed ​​control refers to controlling the rotation speed of the motor so as to drive the motor within a range of a target speed.

[0046] When the control mode of the second motor 22 is set to the speed control, the drive state of the second motor 22 transitions from a stopped state to an accelerated state in this order. This allows the second motor 22 to be driven. Thereafter, the second motor 22 is controlled so that the speed of the second motor 22 is driven within a range of a target speed.

[0047] Furthermore, the control device 100 switches the control mode of the second motor 22 from speed control to torque control when the traverse cutter 40c is in operation and the torque value of the second motor 22 satisfies a predetermined condition. The torque control is a control to drive the motor so that the generated torque is within a range of a target torque.

[0048] The timing when the torque value of the second motor 22 satisfies a predetermined condition during the operation of the traverse cutter 40c is, for example, the position shown in Fig. 3(C). The predetermined condition means a condition in which the torque value of the second motor 22 is equal to or greater than a torque reference value. The setting of the torque reference value will be described in detail later.

[0049] Here, let us consider a method by which the control device 100 grasps the timing during which the traverse cutter 40c is in operation. The time period during which the traverse cutter 40c is in operation is calculated by the above-mentioned formula (1). Therefore, the control device 100 needs to grasp only the operation start time of the traverse cutter 40c. The operation start time of the traverse cutter 40c is, for example, the time when the second arm 10b starts to turn after the winding of the paper 50 on the first winding core 11 is completed (the timing shown in FIG. 3(B)) plus a predetermined time period (first time period). Alternatively, it is the time when the first touch arm 30 starts to advance (the timing shown in FIG. 3(D)) plus a predetermined time period (second time period).

[0050] The first time zone and the second time zone may be information about a predetermined time zone, or may be information about a time zone obtained by measurement.

[0051] Based on this, the control device 100 sets the rotation start flag of the second arm 10b received from the second arm 10b as the rotation start time of the second arm 10b. Alternatively, the control device 100 sets the forward movement start flag of the first touching arm 30 received from the first touching arm 30 as the forward movement start time of the first touching arm 30. Then, the control device 100 adds the first time zone to the rotation start time of the second arm 10b. Alternatively, the control device 100 adds the second time zone to the forward movement start time of the first touching arm 30. This allows the control device 100 to grasp the operation start time of the traverse cutter 40c.

[0052] Furthermore, the control device 100 performs tension correction control on the second motor 22 during operation of the traverse cutter 40c and at a timing when the torque value of the second motor 22 satisfies the above-mentioned predetermined condition. That is, at that timing, the control device 100 switches the control mode of the second motor 22 from speed control to torque control and performs tension correction control on the second motor 22. The tension correction control refers to adjusting the torque value of the motor so that the tension of the paper 50 falls within a target range.

[0053] Furthermore, the control device 100 sets the control mode of the first motor 21 so as to stop the driving of the first motor 21 after switching the control mode of the second motor 22 from speed control to torque control and after the operation of the traverse cutter 40c is completed. Specifically, the control device 100 switches the control mode of the first motor 21 from torque control to stop. When the control mode of the first motor 21 is set to stop, the driving state of the first motor 21 transitions in this order to a deceleration state and a stop state. This allows the driving of the first motor 21 to be stopped.

[0054] Here, let us consider a method by which the control device 100 grasps the operation completion time of the traverse cutter 40c. The operation completion time of the traverse cutter 40c may be, for example, the retreat start time of the second touch arm 40 (the timing shown in FIG. 3(E)). The control device 100 sets the retreat start flag of the second touch arm 40 received from the second touch arm 40 as the retreat start time of the second touch arm 40. This allows the control device 100 to grasp the operation completion time of the traverse cutter 40c.

[0055] 2-2.Example of setting the torque reference value As shown in Fig. 4, the control device 100 sets a torque reference value after starting to drive the second motor 22. The torque reference value is the torque value of the first motor 21 when the tension of the paper 50 is within a target range when the paper 50 is being wound around the first winding core 11. The torque value of the first motor 21 used to set the torque reference value may be predetermined data, or may be data obtained from the first winding core 11 immediately before the paper 50 is wound around the second winding core 12.

[0056] Furthermore, the torque reference value may be a value obtained by adding at least the mechanical loss of the second motor 22 to the torque value of the first motor 21. The mechanical loss means a mechanical loss that depends on the rotation speed of the motor. The mechanical loss differs depending on the individual difference of the second motor 22, and is calculated periodically while the second motor 22 is being driven. The mechanical loss used to set the torque reference value is updated periodically.

[0057] Furthermore, the control device 100 judges whether or not the torque value of the second motor 22 is equal to or greater than a torque reference value during operation of the traverse cutter 40c. If it is judged that the torque value of the second motor 22 is equal to or greater than the torque reference value, the control device 100 switches the control mode of the second motor 22 from speed control to torque control, as shown in Fig. 4. Furthermore, the control device 100 switches the control mode of the second motor 22 from speed control to torque control, as shown in Fig. 4, and performs tension correction control on the second motor 22.

[0058] 2-3.Effects Thus, in the paper winding device 1 according to the embodiment, when the torque value of the second motor 22 is equal to or greater than the torque reference value during operation of the traverse cutter 40c, the control mode of the second motor 22 is switched from speed control to torque control, and tension correction control is performed to adjust the torque value of the second motor 22 so that the tension of the paper 50 falls within a target range. This can improve the stability of winding the paper 50 onto a new winding core when replacing the winding roll.

[0059] 3. Processing example FIG. 5 is a flowchart showing an example of processing by the control device 100 in the paper winding device 1 according to the embodiment.

[0060] In step S100, the control device 100 sets the control mode of the second motor 22 to speed control based on the rotation start flag of the second arm 10b. After that, the process proceeds to step S110.

[0061] In step S110, the control device 100 sets a torque reference value for controlling the rotation of the second motor 22. After that, the process proceeds to step S120.

[0062] In step S120, the control device 100 determines whether the traverse cutter 40c is in operation. If it is determined that the traverse cutter 40c is in operation (step S120; Yes), the process proceeds to step S130. Otherwise (step S120; No), the process returns to step S120.

[0063] In step S130, the control device 100 determines whether the torque value of the second motor 22 is equal to or greater than the reference torque value. If it is determined that the torque value of the second motor 22 is equal to or greater than the reference torque value (step S130; Yes), the process proceeds to step S140. Otherwise (step S130; No), the process returns to step S130.

[0064] In step S140, the control device 100 switches the control mode of the second motor 22 from speed control to torque control. After that, the process proceeds to step S150.

[0065] In step S150, the control device 100 executes tension correction control for the second motor 22. After that, the process proceeds to step S160. Note that the process of step S150 is performed simultaneously with the process of step S140 described above.

[0066] In step S160, the control device 100 switches the control mode of the first motor 21 from torque control to stop. [Explanation of symbols]

[0067] 1...paper winding device, 2...paper winding mechanism, 3...paper cutting section, 10...arm section, 10a...first arm, 10b...second arm, 10c...third arm, 10d...fourth arm, 11...first winding core, 12...second winding core, 13...guide roller, 21...first motor, 22...second motor, 30...first touch arm, 30a...rotating shaft, 30b...nip roll, 40...second touch arm, 40a...rotating shaft, 40b...winding core fixing device, 40c...traverse cutter, 50...paper, 60...moving range, 100...control device

Claims

1. A paper winding device for winding paper, a first winding core on which the paper is to be wound, the first winding core being provided on a first arm that rotates around a rotation axis; A first motor that drives the first winding core; a second winding core on which the paper is to be wound next to the first winding core, the second winding core being provided on a second arm that rotates around the rotation shaft; A second motor that drives the second winding core; A control device that controls the rotation of the first motor and the second motor; Equipped with The control device, in the rotation control, During operation of a traverse cutter that cuts the paper near the second winding core after the first winding core has completed winding the paper and the second arm has rotated to position the second winding core at a position where the paper is to be wound, if the torque value of the second motor is equal to or greater than a reference torque value, the control mode of the second motor is switched from speed control to torque control, and tension correction control is performed to adjust the torque value of the second motor so that the tension of the paper is within a target range. A paper winding device characterized by the above.

2. The paper winding device according to claim 1, The torque reference value is a torque value of the first motor when the tension of the paper is within the target range when the paper is being wound onto the first winding core immediately before the paper is wound onto the second winding core. A paper winding device characterized by the above.

3. The paper winding device according to claim 1, The torque reference value is a value obtained by adding at least a mechanical loss of the second motor to the torque value of the first motor immediately before the paper is wound around the second winding core. A paper winding device characterized by the above.

4. The paper winding device according to claim 3, The mechanical loss is periodically updated while the second motor is being driven. A paper winding device characterized by the above.

5. The paper winding device according to claim 1, The control device further includes, in the rotation control, The control mode of the first motor is set so as to stop driving the first motor after the control mode of the second motor is switched from the speed control to the torque control and after the operation of the traverse cutter is completed. A paper winding device characterized by the above.

6. A paper winding method for winding paper, comprising the steps of: determining whether or not a torque value of a second motor that drives the second winding core is equal to or greater than a torque reference value during operation of a traverse cutter that cuts the paper near the second winding core after completion of winding of the paper by a first winding core that is provided on a first arm that rotates about a rotation axis and is the target onto which the paper should be wound, and after a position of a second winding core that is provided on a second arm that rotates about the rotation axis and is the target onto which the paper should be wound next after the first winding core, is reached; switching a control mode of the second motor from a speed control to a torque control when the torque value of the second motor is determined to be equal to or greater than the torque reference value; performing tension correction control for adjusting a torque value of the second motor so that the tension of the paper falls within a target range; Includes The paper winding method is characterized by the above.

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