Conveyance device

Abstract

Provided is a conveyance device capable of applying a desired tension to a long material in various situations. Specifically, a conveyance device (10) has: a shaft (21) that supports a long material (W) wound into a roll shape and that rotates to unwind the long material (W); and a tension-applying mechanism (22) for applying a tension to the long material (W). The tension-applying mechanism (22) has: a first torque transmission unit (23) that applies a first torque to the shaft (21); and a second torque transmission unit (24) that is capable of transmitting a torque to the shaft (21) through a system different from that of the first torque transmission unit (23), and applies a second torque to the shaft (21) in a direction opposite to that of the first torque.

Description

Transport device

[0001] The present invention relates to a transport device for transporting a long member.

[0002] Patent Document 1 discloses equipment for forming a thin film on a long member (strip-shaped base material). In that equipment, a long member wound in a roll shape is supported by a shaft, and the long member is unwound and transported. Various processes are performed on the transported long member and it is wound around another shaft.

[0003] Japanese Patent Application Laid-Open No. 2014-148724

[0004] In order to stabilize the transport accuracy of the long member, the parallelism and levelness of the shaft etc. are required. When the mass of the roll around which the long member is wound increases, the deflection of the shaft supporting it increases. In order for the deflection of the shaft not to affect the transport accuracy, it is conceivable to increase the diameter of the shaft to increase the rigidity and reduce the deflection. However, in this case, the shaft itself also becomes heavy, and the rotational resistance (resistance torque) due to sliding resistance etc. in the bearing supporting the shaft becomes large.

[0005] For transporting the long member, it is necessary to apply tension to the long member. Therefore, the transport device for the long member has a tension applying mechanism, and on the unwinding side of the long member, torque in the direction opposite to the rotational direction of the shaft (roll) in the unwinding direction is applied to the shaft. In order to apply tension to the long member and further adjust it, it is necessary for the torque applied to the shaft to be larger than the resistance torque due to the rotational resistance of the shaft.

[0006] In such a situation, as the diameter of the shaft increases and the resistance torque of the shaft and the torque applied to move the shaft increase, it may become difficult to control to apply a minute tension to the long member. Therefore, an object of the present invention is to provide a transport device capable of applying a desired tension to a long member in various situations.

[0007] The present invention relates to a conveying device for conveying long materials. The conveying device includes a shaft that supports the long material wound in a roll shape and rotates for unwinding or winding the long material, and a tension-applying mechanism for applying tension to the long material. The tension-applying mechanism includes a first torque transmission unit that applies a first torque to the shaft, and a second torque transmission unit that is capable of transmitting torque to the shaft separately from the first torque transmission unit and applies a second torque to the shaft in the opposite direction to the first torque.

[0008] By adjusting the first and second torques according to the situation, it is possible to apply the desired tension to a long material.

[0009] Figure 1 is an explanatory diagram showing an example of the conveying device of the present invention. Figure 2 is an explanatory diagram showing the transmission torque characteristics of the first powder clutch and the second powder clutch. Figure 3 is an explanatory diagram showing the torque characteristics obtained by combining the first torque and the second torque. Figure 4 is a diagram illustrating another function of the conveying device.

[0010] <Outline of Embodiments of the Invention> Hereinafter, an outline of embodiments of the invention will be listed and described. (1) The present invention is a conveying device for conveying long materials. The conveying device has a shaft that supports the long material wound in a roll shape and rotates for unwinding or winding the long material, and a tension-applying mechanism for applying tension to the long material. The tension-applying mechanism has a first torque transmission unit that applies a first torque to the shaft, and a second torque transmission unit that is capable of transmitting torque to the shaft in a separate system from the first torque transmission unit and applies a second torque to the shaft in the opposite direction to the first torque.

[0011] According to the conveying device, the second torque transmission unit can transmit torque to the shaft via a separate system from the first torque transmission unit. Depending on the situation, the first and second torques can be adjusted, making it possible to apply the desired tension to the long material. In the case of unwinding, the first torque transmission unit applies a first torque to the shaft in the opposite direction to the direction of rotation of the shaft, and the second torque transmission unit applies a second torque to the shaft in the same direction as the direction of rotation of the shaft. In the case of winding, the first torque transmission unit applies a first torque to the shaft in the same direction as the direction of rotation of the shaft, and the second torque transmission unit applies a second torque to the shaft in the opposite direction to the direction of rotation of the shaft.

[0012] (2) In the conveying device of (1), the second torque is smaller than the first torque. This configuration is suitable for obtaining the function of (1). (3) In the conveying device of (2), the first torque transmission unit has a linear relationship in the range of medium output and a nonlinear relationship in the range of low output with respect to the first torque as torque transmission performance. The first torque transmission unit can output the first torque as variable in the range of medium output. The second torque transmission unit outputs the second torque which is included in the lower limit of the range of medium output, or the second torque which is greater than the lower limit. In this case, the torque characteristic obtained by combining the first torque and the second torque can have a linear relationship from zero torque.

[0013] (4) In the conveying device described in (3) above, the second torque transmission unit outputs a constant second torque. In this case, variable output control that changes the output moment by moment is not required in the second torque transmission unit.

[0014] (5) In any one of the conveying devices described in (1) to (4) above, the second torque transmission unit is capable of performing a reversal operation to reverse the direction of the second torque applied to the shaft. In this case, when the second torque transmission unit performs the reversal operation, it becomes possible to apply a greater tension to the long material.

[0015] (6) In any one of the conveying devices described in (1) to (5) above, the first torque transmission unit and the second torque transmission unit each have a powder clutch. In this case, the tension can be easily adjusted.

[0016] <Details of Embodiments of the Present Invention> The details of embodiments of the present invention will be described below. [Overall Configuration of the Conveying Device] Figure 1 is an explanatory diagram showing an example of the conveying device of the present invention. The conveying device 10 shown in Figure 1 is a device for conveying long material W. The conveying device 10 is used, for example, in equipment for forming a thin film on long material W. In that equipment, a long material W wound in a roll shape is supported on a first shaft 21, and the long material W is unwound and conveyed. Various processing is performed on the conveyed long material W by a processing device not shown. The long material W that has undergone various processing is wound onto a second shaft 31. The long material W is a long strip-shaped sheet, for example, a film sheet.

[0017] The long material W is in roll form and supported on the first shaft 21 and the second shaft 31, respectively. The long material W wound in roll form on the first shaft 21 is called the first roll 11. The long material W wound in roll form on the second shaft 31 is called the second roll 12. The conveying device 10 has an unwinding section 20 that unwinds (feeds out) the long material W supported on the first shaft 21, and a winding section 30 that winds the long material W onto the second shaft 31.

[0018] The unwinding section 20 includes a first shaft 21 and a tension-applying mechanism 22 for unwinding. The first shaft 21 supports the rolled long material W and rotates to unwind the long material W. Figure 1 shows the rotation direction of the first shaft 21 and the first roll 11 by arrow R1. The first shaft 21 is supported by bearings provided on a device frame (not shown), and the first shaft 21 is rotatable relative to the device frame. The tension-applying mechanism 22 for unwinding is a device for applying tension to the long material W unwinding from the first roll 11 (first shaft 21).

[0019] The winding section 30 includes a second shaft 31 and a tension-applying mechanism 32 for winding. The second shaft 31 supports the rolled-up long material W and rotates to wind up the long material W. Figure 1 shows the rotation direction of the second shaft 31 and the second roll 12 by arrow R2. The second shaft 31 is supported by bearings provided on a device frame (not shown), and the second shaft 31 is rotatable relative to the device frame. The tension-applying mechanism 32 for winding is a device for applying tension to the long material W that is wound onto the second roll 12 (second shaft 31).

[0020] The conveying device 10 has a plurality of support rollers 15. The support rollers 15 support the long material W to be conveyed. The plurality of support rollers 15 include drive rollers that are driven to rotate and driven rollers that are rotatable without being driven to rotate. The long material W is conveyed from the first shaft 21 side to the second shaft 31 side by the rotational drive of the drive rollers. In this embodiment, a drive roller 151 is provided on the winding section 30 side. The tension of the long material W is divided before and after the conveying direction of the drive roller 151. That is, the long material W has independent tension before and after the drive roller 151.

[0021] [Regarding the unwinding section 20] The tension-applying mechanism 22 for unwinding includes a first torque transmission section 23 capable of transmitting torque to the first shaft 21, and a second torque transmission section 24 capable of transmitting torque to the first shaft 21 via a separate system from the first torque transmission section 23. The second torque transmitted by the second torque transmission section 24 to the first shaft 21 is a torque in the opposite direction to the first torque transmitted by the first torque transmission section 23 to the first shaft 21. Specific examples of the torque direction will be explained later.

[0022] Hereinafter, the first torque transmission unit 23 in the unwinding unit 20 will be referred to as the "first unwinding torque transmission unit 23" and the second torque transmission unit 24 in the unwinding unit 20 will be referred to as the "second unwinding torque transmission unit 24". The first unwinding torque transmission unit 23 includes a first motor 231 for unwinding, a first powder clutch 232 for unwinding, and a first power transmission member 233 for unwinding the chain or the like. The names of each component included in the first unwinding torque transmission unit 23 are preceded by "for unwinding" and "first", but in the following description, "for unwinding" and "first" may be omitted.

[0023] The motor 231 outputs a constant torque. The first powder clutch 232 for unwinding takes the torque of the motor 231 as input and outputs a predetermined torque (first torque). The first powder clutch 232 for unwinding has a first drive rotating member 234 connected to its output shaft. The first drive rotating member 234 is a drive-side sprocket or the like for rotating the power transmission member 233. A first driven rotating member 211 on which the power transmission member (chain) 233 is mounted is connected to the first shaft 21. The first driven rotating member 211 is a driven-side sprocket or the like.

[0024] With the above configuration, the torque of the motor 231 is transmitted to the first shaft 21 in the unwinding first torque transmission unit 23. The torque applied to the first shaft 21 (first torque) is adjustable by the unwinding first powder clutch 232. In this way, the unwinding first torque transmission unit 23 applies (outputs) the first torque to the first shaft 21. The unwinding first torque transmission unit 23 applies the first torque to the first shaft 21 in the direction opposite to the rotation direction of the first shaft 21 (direction of arrow R1). Figure 1 shows the direction of the torque output from the unwinding first powder clutch 232 (direction of rotation of the first drive rotating member 234) by arrow r1.

[0025] The second unwinding torque transmission unit 24 will now be described. As described above, the second unwinding torque transmission unit 24 can transmit torque to the first shaft 21 via a separate system from the first unwinding torque transmission unit 23. For this purpose, the second unwinding torque transmission unit 24 includes a second motor 241 for unwinding, a second powder clutch 242 for unwinding, and a second power transmission member 243 for unwinding a chain or the like. The names of the components included in the second unwinding torque transmission unit 24 are prefixed with "for unwinding" and "second," but these terms may be omitted in the following description.

[0026] Motor 241 outputs a constant torque. The second powder clutch 242 for unwinding takes the torque of motor 241 as input and outputs a predetermined torque (second torque). The second powder clutch 242 for unwinding has a second drive rotating member 244 connected to its output shaft. The second drive rotating member 244 is a drive-side sprocket or the like for rotating the power transmission member 243. A second driven rotating member 212 on which the power transmission member (chain) 243 is mounted is connected to the first shaft 21. The second driven rotating member 212 is a driven-side sprocket or the like.

[0027] With the above configuration, the torque of the motor 241 is transmitted to the first shaft 21 in the unwinding second torque transmission unit 24. The torque applied to the first shaft 21 (second torque) is adjustable by the unwinding second powder clutch 242. In this way, the unwinding second torque transmission unit 24 applies (outputs) a second torque to the first shaft 21. The unwinding second torque transmission unit 24 applies a second torque to the first shaft 21 in the same direction as the rotation direction of the first shaft 21 (direction of arrow R1). Figure 1 shows the direction of the torque output from the unwinding second powder clutch 242 (direction of rotation of the second drive rotating member 244) indicated by arrow r2.

[0028] The second torque applied to the first shaft 21 by the second unwinding torque transmission unit 24 is smaller than the first torque applied to the first shaft 21 by the first unwinding torque transmission unit 23. Since the directions of the first and second torques are opposite, the tension actually applied to the long material W in the unwinding unit 20 is a force equivalent to the difference between the first and second torques.

[0029] The first and second torques in the unwinding section 20 will now be explained. The first powder clutch 232 and the second powder clutch 242 for unwinding each have a function to vary the transmitted torque. Figure 2 is an explanatory diagram showing the transmitted torque characteristics of the first powder clutch 232 and the second powder clutch 242. The transmitted torque (vertical axis of the graph in Figure 2) changes according to the excitation current (horizontal axis of the graph in Figure 2) supplied to the powder clutches 232 and 242, respectively. The second powder clutch 242 has a smaller transmittable torque (maximum value) than the first powder clutch 232.

[0030] As shown in Figure 2, the first powder clutch 232 has a linear relationship in torque transmission performance in the medium and high power range K1, and a nonlinear relationship in the low power range K2. Since the unwinding first torque transmission unit 23 has such a first powder clutch 232, the unwinding first torque transmission unit 23 has a linear relationship in torque transmission performance with respect to the first torque, at least in the medium power range, and a nonlinear relationship in the low power range.

[0031] In this embodiment, the first powder clutch 232 outputs a variable torque within the medium and high output range K1. To this end, the unwinding unit 20 (see Figure 1) includes an unwinding control device 25 and a sensor 27 that detects the tension of the long material W fed out from the first roll 11. The sensor 27 is composed of a tension pickup. Based on the detection result of the sensor 27, the control device 25 outputs a current command value to be given to the first powder clutch 232 for unwinding. The first powder clutch 232 for unwinding transmits torque corresponding to that power command value. As a result, the first unwinding torque transmission unit 23 can output a variable torque (first torque) within the medium and high output range.

[0032] The first torque applied by the first powder clutch 232 is adjusted according to the tension applied to the long material W. In other words, according to the control device 25, when the tension of the long material W detected by the sensor 27 falls below a set value, the first torque is increased, and when the tension of the long material W detected by the sensor 27 falls above a set value, the first torque is decreased. The control device 25 continuously acquires the detection signal from the sensor 27 and performs feedback control based on the detection signal from the sensor 27.

[0033] In contrast, the second powder clutch 242 has a function to vary the transmitted torque, but in this embodiment, it transmits a constant torque during normal operation (normal transport operation of long material W). The unwinding unit 20 has an unwinding power unit 26, and the power unit 26 outputs a constant current to the second powder clutch 242. As a result, the unwinding second torque transmission unit 24 outputs a constant second torque. It is possible to change the transmitted torque (second torque) in the second powder clutch 242 by changing the current output by the power unit 26.

[0034] Let's explain the second torque in detail. The second powder clutch 242 transmits the torque (T2 [N・m]) included in the lower limit range K3 of the medium and high output range K1 (see Figure 2) of the first powder clutch 232. Therefore, the unwinding second torque transmission unit 24 having such a second powder clutch 242 outputs the second torque (T2 [N・m]) included in the lower limit range of the medium output range of the unwinding first torque transmission unit 23.

[0035] Alternatively, the second powder clutch 242 may output a second torque greater than the lower limit K3 of the medium and high output range K1 of the first powder clutch 232. In this case, the unwinding second torque transmission unit 24 outputs a second torque greater than the lower limit of the medium output range of the unwinding first torque transmission unit 23.

[0036] As described above (see Figure 1), the first torque that the unwinding first torque transmission unit 23 applies to the first shaft 21 is a torque in the opposite direction to the rotation direction of the first shaft 21 (first roll 11) (direction of arrow R1). For this reason, the first powder clutch 232 becomes a powder clutch for tension application, and the unwinding first torque transmission unit 23 functions as a torque transmission unit for tension application. In contrast, the second torque that the unwinding second torque transmission unit 24 applies to the first shaft 21 is a torque in the same direction as the rotation direction of the first shaft 21 (first roll 11) (direction of arrow R1). For this reason, as will be explained below, the second powder clutch 242 becomes a powder clutch for cancellation, and the unwinding second torque transmission unit 24 functions as a torque transmission unit for cancellation.

[0037] Figure 3 is an explanatory diagram of the torque characteristics obtained by combining the first torque and the second torque from the first powder clutch 232 and the second powder clutch 242. In Figure 3, the solid line shows the combined torque characteristics, and the dashed line shows the transmission torque characteristics of the first powder clutch 232.

[0038] In Figure 2, the second torque from the second powder clutch 242 is constant at T2 [N·m], and this second torque T2 [N·m] is the torque value in the lower limit range K3 of the medium and high output range K1 of the first powder clutch 232 for unwinding. In this case, the torque obtained by subtracting the constant second torque T2 [N·m] from the variable first torque Tn [N·m] from the first powder clutch 232 is the torque characteristic obtained by combining the first and second torques. Therefore, as shown in Figure 3, the combined torque characteristic has an almost linear relationship from zero torque.

[0039] The first shaft 21 (see Figure 1) is supported by a bearing (not shown), which generates rotational resistance. The second torque that the unwinding second torque transmission unit 24 applies to the first shaft 21 is, as described above, a torque in the same direction as the rotation direction of the first shaft 21 (first roll 11) (direction of arrow R1). Therefore, if the second torque T2 [N・m] from the unwinding second torque transmission unit 24 is set to a value equivalent to the resistance torque due to the rotational resistance, the rotational resistance (resistance torque) is canceled out. In other words, the second torque from the unwinding second torque transmission unit 24 provides an environment in which there is virtually no resistance to the rotation of the first shaft 21. In this embodiment, the second torque is set to a value greater than or equal to the resistance torque of the first shaft 21.

[0040] As a result, as explained below, the first unwinding torque transmission unit 23, which is a torque transmission unit for applying tension, can easily apply low tension to the long material W. Here, in order to apply tension to the long material W, the following equation (1) must be satisfied.

[0041] Equation (1): Tr < T22 Tr is the resistance torque of the first shaft 21, and T22 is the torque applied to the first shaft 21 by the tension-applying mechanism 22 for unwinding. Note that when applying low tension to a long material W, T22 is set to a value slightly larger than Tr.

[0042] However, when the diameter of the first roll 11 decreases as the long material W is fed out from the first roll 11, equation (1) may no longer be satisfied. In this case, it becomes difficult to apply low tension to the long material W. Also, if the rotational resistance of the first shaft 21 changes due to the continuous use of the conveying device 10 and the resistance torque increases, equation (1) will no longer be satisfied. In this case as well, it becomes difficult to apply low tension to the long material W.

[0043] In such a case, if only the unwinding first torque transmission unit 23 is used, it becomes difficult to adjust the tension when applying a low tension to the long member W. However, the tension applying mechanism 22 for unwinding in the present embodiment further includes an unwinding second torque transmission unit 24. The unwinding second torque transmission unit 24 can apply a desired tension to the long member W even when the state of the first shaft 21 changes by additionally applying a torque corresponding to the change in rotational resistance as described above to the first shaft 21.

[0044] And, the unwinding first torque transmission unit 23 has a linear relationship in the medium output and high output ranges K1 as the torque transmission characteristic regarding the first torque, as described above (FIG. 2), while having a non-linear relationship in the low output range K2. Therefore, the unwinding second torque transmission unit 24 transmits a second torque (T2 [N·m]) in the opposite direction to the first torque, which is a torque corresponding to the low output, to the first shaft 21. As a result, as shown in FIG. 3, it becomes possible to cancel the low output range K2 (FIG. 2). As a result, the tension applying mechanism 22 for unwinding having the unwinding second torque transmission unit 24 in addition to the unwinding first torque transmission unit 23 can have a torque transmission performance with a linear relationship. Even when applying a low tension to the long member W, the control of torque adjustment becomes easy.

[0045] As described above, according to the conveying device 10 of the present embodiment, the unwinding second torque transmission unit 24 can transmit torque to the first shaft 21 in a different system from the unwinding first torque transmission unit 23. The unwinding first torque transmission unit 23 can function to apply tension to the long member W. The unwinding second torque transmission unit 24 can function to absorb the rotational resistance of the first shaft 21 and also to cancel the low output range K2 for the first torque. By adjusting the first torque and the second torque respectively according to the situation, it becomes possible to apply a desired tension to the long member W.

[0046] As described with reference to FIG. 3, the torque characteristic obtained by synthesizing the first torque and the second torque has a linear relationship starting from zero torque. Therefore, it is possible to associate the relationship between the control current value by the control device 25 and the transmission torque with a simple calculation formula, facilitating the operation control by the control device 25. Further, according to the conveying device 10 of the present embodiment, by setting the second torque to a value larger than the resistance torque of the first shaft 21 with a margin, even if the resistance torque changes (increases) due to aging, it is possible to apply a stable tension to the long material W.

[0047] FIG. 4 is a diagram for explaining another function of the conveying device 10 of the present embodiment. The configuration of the conveying device 10 shown in FIG. 4 is the same as the configuration of the conveying device 10 shown in FIG. 1. FIG. 4 shows the conveying device 10 when applying an even higher tension to the long material W. In the unwinding section 20, the unwinding second torque transmission section 24 is capable of performing an inversion operation to invert the direction of the second torque applied to the first shaft 21. That is, the unwinding second torque transmission section 24 applies a second torque in the direction opposite to the rotation direction of the first shaft 21 (the direction of arrow R1) to the first shaft 21. FIG. 4 indicates the direction of the torque output from the second powder clutch 242 for unwinding (the rotation direction of the second drive rotating member 244) by arrow r21. To achieve this, for example, the rotation direction of the second motor 241 for unwinding may be inverted.

[0048] According to the above inversion operation, the unwinding second torque transmission section 24 also functions as a torque transmission section for tension addition, similar to the unwinding first torque transmission section 23. When the unwinding second torque transmission section 24 performs the above inversion operation, it is possible to apply a greater tension to the long material W. Compared with the normal operation shown in FIG. 1, in the case of the inversion operation shown in FIG. 4, the tension application mechanism 22 for unwinding of the conveying device 10 can apply an even higher tension to the long material W.

[0049] As described above, the tension-applying mechanism 22 for unwinding in the conveying device 10 of this embodiment makes it possible to apply a desired tension from low to high to the long material W depending on the situation. In particular, the first unwinding torque transmission unit 23 and the second unwinding torque transmission unit 24 each have powder clutches (232, 332), which makes it possible to easily adjust the tension applied to the long material W.

[0050] [Regarding the winding section 30] As shown in Figure 1, the tension-applying mechanism 32 for winding has a first torque transmission section 33 that can transmit torque to the second shaft 31, and a second torque transmission section 34 that can transmit torque to the second shaft 31 in a separate system from the first torque transmission section 33. The second torque transmitted by the second torque transmission section 34 to the second shaft 31 is a torque in the opposite direction to the first torque transmitted by the first torque transmission section 33 to the second shaft 31. Specific examples of the torque direction will be explained later.

[0051] Hereinafter, the first torque transmission unit 33 in the winding unit 30 will be referred to as the "first winding torque transmission unit 33" and the second torque transmission unit 34 in the winding unit 30 will be referred to as the "second winding torque transmission unit 34". The first winding torque transmission unit 33 includes a first motor 331 for winding, a first powder clutch 332 for winding, and a first power transmission member 333 for winding a chain or the like. The names of each component included in the first winding torque transmission unit 33 are prefixed with "for winding" and "first", but in the following description, "for winding" and "first" may be omitted.

[0052] Motor 331 outputs a constant torque. First powder clutch 332 for winding takes the torque of motor 331 as input and outputs a predetermined torque (first torque). First powder clutch 332 for winding has a first drive rotating member 334 connected to its output shaft. First drive rotating member 334 is a drive-side sprocket or the like for rotating the power transmission member 333. A first driven rotating member 311 on which the power transmission member (chain) 333 is mounted is connected to the second shaft 31. First driven rotating member 311 is a driven-side sprocket or the like.

[0053] With the above configuration, the torque of the motor 331 is transmitted to the second shaft 31 in the first winding torque transmission unit 33. The torque applied to the second shaft 31 (first torque) is adjustable by the first winding powder clutch 332. In this way, the first winding torque transmission unit 33 applies (outputs) the first torque to the second shaft 31. The first winding torque transmission unit 33 applies the first torque to the second shaft 31 in the same direction as the rotation direction of the second shaft 31 (direction of arrow R2). In Figure 1, the direction of the torque output from the first winding powder clutch 332 (direction of rotation of the first drive rotating member 334) is indicated by arrow r3.

[0054] The second winding torque transmission unit 34 will now be described. As described above, the second winding torque transmission unit 34 can transmit torque to the second shaft 31 via a separate system from the first winding torque transmission unit 33. For this purpose, the second winding torque transmission unit 34 includes a second motor 341 for winding, a second powder clutch 342 for winding, and a second power transmission member 343 for winding a chain or the like. The names of the components included in the second winding torque transmission unit 34 are prefixed with "for winding" and "second," but these terms may be omitted in the following description.

[0055] Motor 341 outputs a constant torque. The second powder clutch 342 for winding takes the torque of motor 341 as input and outputs a predetermined torque (second torque). The second powder clutch 342 for winding has a second drive rotating member 344 connected to its output shaft. The second drive rotating member 344 is a drive-side sprocket or the like for rotating the power transmission member 343. A second driven rotating member 312, on which the power transmission member (chain) 343 is mounted, is connected to the second shaft 31. The second driven rotating member 312 is a driven-side sprocket or the like.

[0056] With the above configuration, the winding second torque transmission unit 34 transmits the torque of the motor 341 to the second shaft 31. The torque applied to the second shaft 31 (second torque) is adjustable by the winding second powder clutch 342. In this way, the winding second torque transmission unit 34 applies (outputs) a second torque to the second shaft 31. The winding second torque transmission unit 34 applies a second torque to the second shaft 31 in the opposite direction to the rotation direction of the second shaft 31 (direction of arrow R2). Figure 1 shows the direction of the torque output from the winding second powder clutch 342 (direction of rotation of the second drive rotating member 344) by arrow r4.

[0057] The second torque applied to the second shaft 31 by the second winding torque transmission unit 34 is smaller than the first torque applied to the second shaft 31 by the first winding torque transmission unit 33. Since the directions of the first and second torques are opposite, the tension actually applied to the long material W in the winding unit 30 is a force equivalent to the difference between the first and second torques.

[0058] The first and second torques in the winding section 30 will now be described. The first winding powder clutch 332 and the second winding powder clutch 342, like the first unwinding powder clutch 232 and the second unwinding powder clutch 242, each have a function to vary the transmitted torque (see Figure 2). The second winding powder clutch 342 has a smaller maximum transmittable torque than the first winding powder clutch 332.

[0059] As shown in Figure 2, the first powder clutch 332 for winding, like the first powder clutch 232 for unwinding, has a linear relationship in torque transmission performance in the medium and high power range K1, and a nonlinear relationship in the low power range K2. Since the first winding torque transmission unit 33 has such a first powder clutch 332 for winding, the first winding torque transmission unit 33 has a linear relationship in torque transmission performance with respect to the first torque, at least in the medium power range, and a nonlinear relationship in the low power range.

[0060] In this embodiment, the first powder clutch 332 outputs a variable torque within the medium and high output range K1. To this end, the winding unit 30 (see Figure 1) includes a winding control device 35 and a sensor 37 that detects the tension of the long material W sent to the second roll 12. The sensor 37 is composed of a tension pickup. Based on the detection result of the sensor 37, the control device 35 outputs a current command value to be given to the first powder clutch 332 for winding. The first powder clutch 332 for winding transmits torque corresponding to that power command value. As a result, the first winding torque transmission unit 33 can output a variable torque (first torque) within the medium and high output range.

[0061] The first torque applied by the first powder clutch 332 is adjusted according to the tension applied to the long material W. In other words, according to the control device 35, when the tension of the long material W detected by the sensor 37 falls below a set value, the first torque is increased, and when the tension of the long material W detected by the sensor 37 falls above a set value, the first torque is decreased. The control device 35 continuously acquires the detection signal from the sensor 37 and performs feedback control based on the detection signal from the sensor 37.

[0062] In contrast, the second powder clutch 342 has a function to vary the transmitted torque, but in this embodiment, it transmits a constant torque during normal operation (normal transport operation of long material W). The winding unit 30 has a power unit 36 ​​for winding, and the power unit 36 ​​outputs a constant current to the second powder clutch 342. As a result, the winding second torque transmission unit 34 outputs a constant second torque. It is possible to change the transmitted torque (second torque) in the second powder clutch 342 by changing the current output by the power unit 36.

[0063] The second torque will now be explained in detail. The second powder clutch 342 transmits the torque (T12 [N・m]) included in the lower limit range K3 of the medium and high output range K1 (see Figure 2) of the first powder clutch 332. The winding second torque transmission unit 34, which has such a second powder clutch 342, outputs the second torque (T12 [N・m]) included in the lower limit range of the medium output range of the winding first torque transmission unit 33.

[0064] Alternatively, the second powder clutch 342 may output a second torque greater than the lower limit K3 of the medium and high output range K1 of the first powder clutch 332. In this case, the second winding torque transmission unit 34 outputs a second torque greater than the lower limit of the medium output range of the first winding torque transmission unit 33.

[0065] As described above (see Figure 1), the first torque that the first winding torque transmission unit 33 applies to the second shaft 31 is a torque in the same direction as the rotation direction of the second shaft 31 (second roll 12) (direction of arrow R2). For this reason, the first powder clutch 332 becomes a powder clutch for tension application, and the first winding torque transmission unit 33 functions as a torque transmission unit for tension application. In contrast, the second torque that the second winding torque transmission unit 34 applies to the second shaft 31 is a torque in the opposite direction to the rotation direction of the second shaft 31 (second roll 12) (direction of arrow R2).

[0066] Therefore, the second powder clutch 342 for winding becomes a cancellation powder clutch, and the second winding torque transmission unit 34 functions as a cancellation torque transmission unit. This is the same as the relationship between the first powder clutch 232 and the second powder clutch 242 in the unwinding unit 20.

[0067] In the winding section 30, the second torque from the second winding torque transmission section 34 is constant at T12 [N・m], and this second torque T12 [N・m] is the torque value in the lower limit range K3 of the medium and high output range K1 in the first winding torque transmission section 33. Therefore, the torque obtained by subtracting the constant second torque T12 [N・m] from the variable first torque Tm [N・m] from the first winding torque transmission section 33 becomes the torque characteristic of the winding section 30 as a combination of the first and second torques. Consequently, in the winding section 30 as shown in Figure 3, the combined torque characteristic has an almost linear relationship from zero torque.

[0068] In this embodiment, in the winding section 30, the first winding torque transmission section 33 has a linear relationship in the medium and high output range K1 with respect to the first torque, as described above (Figure 2), but a nonlinear relationship in the low output range K2. Therefore, the second winding torque transmission section 34 transmits a second torque (T12 [N・m]) corresponding to the low output, which is in the opposite direction to the first torque, to the second shaft 31. As a result, as with the unwinding section 20, it becomes possible to cancel the low output range K2 (Figure 2), as shown in Figure 3. Consequently, the tension-applying mechanism 32 for winding, which has a second winding torque transmission section 34 in addition to the first winding torque transmission section 33, can have torque transmission performance with a linear relationship. Even when applying low tension to a long material W, torque adjustment control becomes easier.

[0069] As described above, according to the conveying device 10 of this embodiment, the second winding torque transmission unit 34 can transmit torque to the second shaft 31 in a separate system from the first winding torque transmission unit 33. The first winding torque transmission unit 33 can function to apply tension to the long material W. The second winding torque transmission unit 34 can function to cancel the low output range K2 for the first torque. By adjusting the first torque and the second torque respectively according to the situation, it is possible to apply the desired tension to the long material W.

[0070] Figure 4 shows the conveying device 10 when an even higher tension is applied to the long material W, as described above. In the winding section 30, the second winding torque transmission section 34 is capable of reversing the direction of the second torque applied to the second shaft 31. In other words, the second winding torque transmission section 34 applies a second torque to the second shaft 31 in the same direction as the rotation direction of the second shaft 31 (direction of arrow R2). In Figure 4, the direction of the torque output from the second powder clutch 342 for winding (the rotation direction of the second drive rotating member 344) is indicated by arrow r41. To achieve this, for example, the rotation direction of the second motor 341 for winding can be reversed.

[0071] According to the reversal operation, the second winding torque transmission unit 34 also functions as a torque transmission unit for applying tension, similar to the first winding torque transmission unit 33. When the second winding torque transmission unit 34 performs the reversal operation, it becomes possible to apply greater tension to the long material W.

[0072] As described above, the tension-applying mechanism 32 for winding in the conveying device 10 of this embodiment makes it possible to apply a desired tension from low to high to the long material W depending on the situation. In particular, the winding first torque transmission unit 33 and the winding second torque transmission unit 34 each have powder clutches (332, 342), which makes it possible to easily adjust the tension applied to the long material W.

[0073] [Other] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is not limited to the embodiments described above, and includes all modifications within the scope equivalent to the configurations described in the claims.

[0074] 10 Conveying device 21 First shaft 22 Tensioning mechanism 23 First torque transmission unit 24 Second torque transmission unit 31 Second shaft 32 Tensioning mechanism 33 First torque transmission unit 34 Second torque transmission unit 232 First powder clutch 242 Second powder clutch 332 First powder clutch 342 Second powder clutch W Long material

Claims

1. A conveying device for transporting long materials, comprising: a shaft that supports the long material wound in a roll and rotates for unwinding or winding the long material; and a tension-applying mechanism for applying tension to the long material, wherein the tension-applying mechanism comprises: a first torque transmission unit that applies a first torque to the shaft; and a second torque transmission unit that is capable of transmitting torque to the shaft in a separate system from the first torque transmission unit and applies a second torque to the shaft in the opposite direction to the first torque.

2. The conveying device according to claim 1, wherein the second torque is smaller than the first torque.

3. The conveying device according to claim 2, wherein the first torque transmission unit has a linear relationship in the range of medium output and a nonlinear relationship in the range of low output with respect to the first torque as torque transmission performance, the first torque transmission unit is capable of outputting the first torque in a variable manner in the range of medium output, and the second torque transmission unit outputs the second torque which is included in the lower limit range of the range of medium output, or the second torque which is greater than the lower limit range.

4. The conveying device according to claim 3, wherein the second torque transmission unit outputs a constant second torque.

5. The conveying device according to any one of claims 1 to 4, wherein the second torque transmission unit is capable of performing a reversal operation to reverse the direction of the second torque applied to the shaft.

6. The conveying device according to any one of claims 1 to 4, wherein the first torque transmission unit and the second torque transmission unit each have a powder clutch.

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