JP2003054800A - Tension control device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tension control device and a tension control method capable of inhibiting the variation of tension of a web caused by the movement of a dancer roll from a predetermined position, when the predetermined tension is applied to the continuously traveling web by the dancer roller. SOLUTION: This tension control device has a reference roller part 10 and a feed roller part 20 for traveling the web 80, a dancer roller device 30 having the dancer roller 31 for taking up the traveling web 80, an arm 32 rotatably held on a predetermined spindle 34 for rotatably holding the dancer roller 31, and an actuator 40 for applying the predetermined force to the arm 32, and a control device 50 for controlling speeds of the reference roller part 10 and the feed roller part 20 to locate the arm 32 on a predetermined position, and controlling the force generated from the actuator 40 to unify the force acting on the web 80 from the dancer roller 31 corresponding to an angle of rotation of the arm 32 from the predetermined position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension control device and a tension control method for controlling the tension of a continuously running web.

[0002]

2. Description of the Related Art Generally, tension control of a continuously running web is performed by a dancer roller device. Conventionally,
Known dancer roller devices of this type mainly adjust the tension of the web by moving a weight and adjust the tension of the web by the pressure of compressed air sent to an air cylinder. A dancer roller device that adjusts the tension of a web by moving a weight rotates a dancer roller 101 that wraps a web 110 around the tip of an arm 100 that is rotatably provided in a vertical plane, as shown in FIG. By providing the arm 100 to be movable and the weight 103 to the arm 100, tension is applied to the web 110 via the dancer roller 101. On the other hand, a dancer roller device that adjusts the tension of the web by the pressure of the compressed air sent to the air cylinder is disclosed in, for example, Japanese Patent Laid-Open No. 59-4557. This dancer roller device is shown in FIG.
As shown in FIG. 2, the web 2 is attached to the tip of an arm 201 that is rotatably supported by a support shaft 200 and hangs vertically downward.
A dancer roller 202 that wraps 10 is rotatably provided, and an air cylinder 220 that is supplied with compressed air and generates a constant thrust is provided to the arm 201, thereby giving a predetermined moment to the arm 201, and the web 21
Tension is applied to 0. The running speed of the web 210 is controlled so that the dancer roller 202 is located at a fixed position.

[0003]

By the way, in the dancer roller device for adjusting the tension of the web 210 by the pressure of the compressed air sent to the air cylinder 220 as described above, the position of the dancer roller 202 is kept constant. In some cases, a constant force can be applied to the web 210. On the other hand, when the dancer roller 202 moves from a predetermined position due to a change in the traveling speed of the web 210 due to disturbance or the like, the arm 201 holding the dancer roller 202 tilts with respect to the vertical direction.
A force such as a horizontal component of the weight of the dancer roller 202 acts on the air cylinder 220. Due to the action of this force, the force acting on the web 210 from the dancer roller 202 fluctuates. When the force acting on the web 210 from the dancer roller 202 changes, the tension of the web 210 changes greatly until the dancer roller 202 returns to a fixed position. If the tension of the web 210 fluctuates greatly, extra tension will be applied to the web 210, especially when the web 210 is thin. For example, when the web 210 is a base film of a magnetic recording medium,
If excessive tension is applied to the base film, distortion may occur in the base film, which may adversely affect the quality of the magnetic recording medium.

The present invention has been made in view of the above problems, and an object of the present invention is to make a dancer roller move from a predetermined position when a predetermined tension is applied to a continuously running web by the dancer roller. An object of the present invention is to provide a tension control device and a tension control method capable of suppressing fluctuations in the tension of the web generated by moving.

[0005]

The tension control device of the present invention is a tension control device for controlling the tension of a continuously running web to a set tension, which is provided in the running path of the web, First and second traveling means for traveling, a dancer roller around which the web traveling from the first traveling toward the second traveling means is wound, and rotatably held around a predetermined supporting shaft. And a dancer roller device having an arm for rotatably holding the dancer roller, and an actuator for applying a predetermined force according to a set tension to the arm in a direction in which tension is generated on the web, and the web at a predetermined speed. First control means for controlling the speed of the first and second traveling means so that the arm is located at a predetermined position and the predetermined position of the arm. Depending on the angle of rotation from the forces acting on the web from the dancer roller and a second control means for controlling the force to be generated by the actuator so as to be constant.

Preferably, it has an angle detector for detecting the rotation angle of the arm and outputting a detection signal to the second control means.

Preferably, the actuator has an air cylinder and an electropneumatic converter for adjusting the pressure of the compressed air supplied to the air cylinder in accordance with a control command from the second control device.

More preferably, the second control means is
A correction amount for correcting the force based on the weight of the arm and the dancer roller that acts on the actuator from the arm and that changes in accordance with the rotation of the arm from the predetermined position is calculated, and the actuator is based on the correction amount. Correct the control command output to.

The tension control method of the present invention comprises a dancer roller around which a running web is wound, an arm rotatably held around a predetermined support shaft and rotatably holding the dancer roller, and the arm. A tension control method for controlling the tension of a continuously running web by a dancer roller device having an actuator that applies a predetermined force according to a set tension in a direction in which a tension is generated in the web, the web being moved at a predetermined speed. The dancer roller acts on the web according to the rotation angle of the arm from the predetermined position while the web is controlled to run so that the arm is located at the predetermined position. The force generated by the actuator is controlled so that the applied force becomes constant.

In the present invention, the installation tension is applied to the web running at the predetermined speed by the first and second running means by generating a predetermined force from the actuator of the dancer roller device. When the traveling speed of the web changes due to disturbance or the like, the dancer roller moves from a predetermined position and the arm rotates. As the arm rotates, the force that the actuator receives from the arm changes. Therefore, the force acting on the web from the dancer roller tends to fluctuate. The second control means controls the force generated in the actuator according to the rotation angle of the arm so that the force acting on the web from the dancer roller is constant, that is, does not change. This suppresses fluctuations in web tension.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an embodiment of a tension control device of the present invention. The tension control device 1 shown in FIG. 1 is for continuously running while controlling the tension of the web 80 to a set tension.
, Feed roll unit 20, dancer roller device 30
And a control device 50. The reference roll unit 10
Is an embodiment of the first traveling means of the present invention, the conveying roller unit 20 is an embodiment of the second traveling means of the present invention, and the control device 50 is the first and second control means of the present invention. It is an embodiment of a means.

As the web 80, for example, a flexible film having a predetermined width formed of a polymer material, or a magnetic recording medium having a magnetic layer formed on the surface of the film is used.

The reference roll unit 10 includes a reference roll 11 and
The nip roll 12 installed on the reference roll 11
And an electric motor 13 for rotating the reference roller 11, and a driver 14 for driving the electric motor 13.

The reference roll 11 is rotatably held, supports the web 80 by the outer peripheral surface thereof, and rotates in a predetermined direction to cause the web 80 to travel by a frictional force. The nip roll 12 is installed on the reference roll 11, and the web 80 is set by an air cylinder (not shown).
It is pressed against the reference roll 11 via. Nip roll 1
By pressing 2 onto the reference roll 11 via the web 80, the web 80 is prevented from slipping on the outer peripheral surface of the reference roll 11.

The output shaft of the electric motor 13 is connected to the central shaft of the reference roll 11 to rotate the reference roll 11. The driver 14 supplies a drive current according to the speed command Vs input from the control device 50 to the electric motor 13 to drive the electric motor 13.

The feed roll unit 20 has a feed roll 21, a nip roll 22 installed on the transport roller 21, an electric motor 23 for rotating the feed roll 21, and a driver 24 for driving the electric motor 23.

The feed roll 21 is rotatably held, supports the web 80 by the outer peripheral surface thereof, and rotates in the same direction as the reference roll 11, so that the web 80 fed from the reference roll 11 has a frictional force. To drive further downstream. The nip roll 22 is installed on the feed roll 21, and is pressed against the feed roll 21 via the web 80 by an air cylinder (not shown). By pressing the nip roll 22 against the feed roll 21 via the web 80, the web 80 is prevented from slipping on the outer peripheral surface of the feed roll 21.

The output shaft of the electric motor 23 is connected to the central shaft of the feed roll 21 to rotate the feed roll 21. The driver 24 supplies a drive current according to the speed command Vf input from the control device 50 to the electric motor 23 to drive the electric motor 23.

FIG. 2 is a block diagram showing an example of the structure of the dancer roller device 30. As shown in FIG. 2, the dancer roller device 30 includes an arm 32, a dancer roller 31 rotatably held at the tip of the arm 32, and an arm 3.
Air cylinder 40 in which piston rod 41 is connected to 2
And an electropneumatic converter 41 that supplies compressed air 41a to the air cylinder 40.

The upper end of the arm 32 is rotatably supported on the frame FL by a support shaft 34 and hangs vertically downward. The arm 32 is rotatable about a support shaft 34. Further, the arm 32 is provided with an angle detector 33 that detects a rotation angle of the arm 32 about the support shaft 34. This angle detector 33
Outputs the detected arm angle signal 33s to the control device 50.

The dancer roller 31 is rotatably held at the lower end of the arm 32. This dancer roller 3
1, the web 80 wound around the outer peripheral surface is guided by a plurality of guide rollers gr.

The air cylinder 40 is connected to the frame FL via a clevis pin.
A piston rod 41, which is housed at 0 in an expandable and contractible manner in the directions of arrows A1 and A2, is pivotally mounted midway in the arm 32. It is preferable that the air cylinder 40 has a low sliding friction between the piston rod 41 and the air cylinder 40 from the viewpoint of improving responsiveness.

The electropneumatic converter 41 adjusts the pressure of the compressed air supplied from the air source 42 according to a control command ra input from the control device 50 and supplies the compressed air to the air cylinder 40. As a result, the air cylinder 40 outputs a thrust force according to the control command ra. When the air cylinder 40 presses the arm 32 with a predetermined force, the dancer roller 31
A predetermined tension of the web 80 wound around the web is generated.

The control device 50 shown in FIG. 1 includes an angle correction amount calculation unit 51, an adder 52, an arm position storage unit 53,
Position comparison unit 54, speed conversion unit 55, and adder 56
And a tension setting device 57 and a speed setting device 58.

The control unit 50 includes electric motors 13 and 2
3, an arm position storage unit 53, a position comparison unit 54,
Speed conversion converter 55, adder 56 and speed setter 58
And a tension setting device 5 for controlling the force generated by the air cylinder 40.
7, an angle correction amount calculation section 51, and an adder 52 corresponding to the second control means of the present invention.

The speed setter 58 is for setting the reference speed (traveling speed) of the web 80, and the reference speed command V corresponding to the reference speed set in the speed setter 58.
s is output to the driver 14 and the adder 56. As a result, the electric motor 13 is driven at a rotation speed according to the reference speed command Vs. Further, the reference speed command Vs output to the adder 56 is added to the corrected speed command Vm output from the speed conversion unit 55 and output to the driver 24 as a new speed command Vf. As a result, the electric motor 23
Is driven at a rotation speed according to the new speed command Vf.
When the corrected speed command Vm is 0, the electric motors 13 and 23 are driven at the same rotation speed.

The arm position storage section 53 stores reference position information in the rotation direction of the arm 32 about the support shaft 34. This reference position information is the position of the arm 32 when the arm 32 hangs in the vertical direction.

The position comparing section 54 is provided with the arm angle signal 3 detected by the angle detector 33 provided on the arm 32.
3s is input, and the tilt angle θ of the arm 32 from the vertical direction is calculated based on the arm angle signal 33s and the reference position stored in the arm position storage unit 53. This inclination angle θ is the control deviation.

The speed conversion conversion unit 55 calculates and adds the corrected speed command Vm based on the tilt angle θ calculated by the position comparison unit 54 so that the position of the arm 32 becomes the reference position in the vertical direction. Output to the device 56. As described above, the corrected speed command Vm output to the adder 56 is added to the reference speed command Vs and output to the driver 24. As a result, the position of the arm 32 is controlled so as to be maintained in the vertical direction.

The tension setting device 57 sets the value of the tension applied to the traveling web 80 by the air cylinder 40. Set tension signal 5 set by the tension setter 57
7s is output to the adder 52. The set tension signal 57s output to the adder 52 is used as it is when the correction amount 51s from the angle correction amount calculation unit 51 is 0.
It is output to 1. As a result, the air cylinder 40 generates a thrust force according to the set tension signal 57s, and the set tension is generated on the web 80.

The angle correction amount calculation section 51 includes an angle detector 33.
The arm angle signal 33s is input from. The angle correction amount calculation unit 51 applies to the air cylinder 40 so that the force acting on the web 80 from the dancer roller 31 becomes constant according to the inclination angle θ of the arm 32 from the vertical direction specified by the arm angle signal 33s. A correction amount 51s for correcting the generated force is calculated and output to the adder 52.
In the adder 52, the correction amount 51s is set to the set tension signal 57.
s is added and corrected, and the electropneumatic converter 4 is used as the control command ra.
Output to 1.

Next, a method of calculating the correction amount 51s in the angle correction amount calculation unit 51 will be described. FIG. 3 is a diagram for explaining the force required to move the dancer roller 31 in the dancer roller device 30. First, consider the thrust F ₀ of the air cylinder 40 required to move the dancer roller 31 when the arm 32 holding the dancer roller 31 is positioned in the vertical direction. In addition,
It is assumed that the thrust F ₀ does not include the tension of the web 80.
In FIG. 3, the diameter of the support shaft 34 is d, the coefficient of friction between the support shaft 34 and a bush that rotatably holds the support shaft 34 is μ, and the connection position between the support shaft 34 and the air cylinder 40 and the arm 32. Is L, and the weight of the arm 32 and the dancer roller 31 is W.

The frictional force f between the support shaft 34 and the bush that rotatably holds the support shaft 34 is represented by f = μW. Further, the relationship of F ₀ L = μW × d / 2 holds. Therefore, the thrust F ₀ is expressed by the following equation (1).

F ₀ = μWd / (2L) (1)

As can be seen from the equation (1), when the arm 32 holding the dancer roller 31 is positioned in the vertical direction, the thrust force F ₀ is the weight W, the friction coefficient μ, the diameter d of the support shaft 34, and Is a frictional force determined by the distance L from the support shaft 34 to the connecting position of the air cylinder 40 and the arm 32.

On the other hand, disturbances or the like occur in the web 80 and
80 is loosened, and the arm 32 is leaded as shown in FIG.
When tilted at a tilt angle θ from the vertical direction, dancer low
Thrust force F of the air cylinder 40 required to move the rotor 31
Consider θ. The thrust force Fθ causes the arm 32 to tilt from the vertical direction.
By tilting, the arm 32 and the dancer roller 3
Since the force fluctuates with the force based on the weight W of 1,
Force F ₀ Is different from. That is, the arm 32 tilts
And the force acting on the air cylinder 40 through the arm 32
Is not only the frictional force between the support shaft 34 and the bush,
Based on weight W of arm 32 and dancer roller 31
Power acts. Therefore, dancer roller 31
In order to make the force acting on the hook 80 constant,
It is necessary to correct the force generated by the da 40. Air silin
If the force generated by da 40 remains constant,
Since the force acting on the web 80 from the roller 31 decreases,
Tension decreases. On the contrary, tension is generated on the web 80,
The dancer roller 31 is vertically oriented in the opposite direction to that shown in FIG.
If tilted from the opposite direction, arm 32 and dancer lo
The force based on the weight W of the roller 31 reverses to the air cylinder 40.
The dancer roller 31 to the web 80
The force acting on increases the tension.

FIG. 5 is a diagram for explaining the thrust Fθ required to move the dancer roller 31 when the arm 32 is tilted at the tilt angle θ from the vertical direction. Assuming that the clevis pin of the air cylinder 40 is at infinity and the thrust of the air cylinder 40 acts in the horizontal direction, the thrust Fθ has the relationship shown in FIG. Therefore, the thrust Fθ can be calculated by the following equation (2).

Fθ = W · tan θ + W · d · μ / (2L cos θ ² ) (2)

In the angle correction amount calculation unit 51, the angle detector 3
The thrust Fθ is calculated from the above equation (2) based on the inclination angle θ of the arm 32 detected in 3, and this is calculated as the correction amount 51s.
Is output to the adder 52. In the adder 52, the correction amount 51s is added to the set tension signal 57s, and the electropneumatic converter 4
Output to 1. As a result, even if the arm 32 is tilted at the tilt angle θ from the reference position, the force acting on the web 80 from the dancer roller 31 is kept constant, and the fluctuation of the tension of the web 80 is suppressed.

Next, an example of the operation of the tension control device 1 will be described. First, a desired tension is set by the tension setting device 57, a reference speed of the web 80 is set by the speed setting device 58, and the web 80 is run.

For the web 80 traveling at the reference speed,
A force corresponding to the set tension is applied from the dancer roller 31. At this time, the speed control of the feed roll 21 is performed so that the arm 32 is located at the reference position in the vertical direction.

When the traveling speed of the web 80 changes from the reference speed due to disturbance or the like, and the arm 32 tilts from the vertical direction, the tilt angle θ is detected by the angle detector 33.

The tilt angle θ detected by the angle detector 33 is input to the position comparison unit 54 and the angle correction amount calculation unit 51 of the control device 50. By inputting the inclination angle θ to the position comparison unit 54, the correction speed command Vm for moving the arm 32 to the reference position in the vertical direction is calculated, and the arm 32 is calculated.
Is feedback controlled so that it is returned to the vertical direction.

On the other hand, the angle correction amount calculation unit 51 calculates a correction amount 51s for correcting the thrust force of the air cylinder 40 for keeping the force acting on the web 80 from the dancer roller 31 constant based on the inclination angle θ. To do. As a result, the thrust of the air cylinder 40 is continuously corrected between the time when the arm 32 tilts from the reference position due to disturbance or the like and the time when the arm 32 returns to the reference position again by the above feedback control. Therefore, the amount of change in the tension of the web 80 is significantly suppressed as compared with the case where the thrust of the air cylinder 40 is constant.

FIG. 6 is a tension control device 1 according to this embodiment.
6 is a graph showing the results of measuring the tension fluctuations when the tension of the web 80 is controlled by using. In addition, FIG.
6 is a graph showing the results of measuring the tension fluctuations when the tension of the web 80 is controlled with the thrust of the air cylinder 40 kept constant. 6 and 7, the graph CV1 shows the inclination angle θ of the arm 32, and the graph CV2 shows the tension of the web 80. Further, while the tension control was being performed, the arm 32 was tilted at an inclination angle θ of about 12 ° to forcibly give a disturbance.

As can be seen from FIG. 6 and FIG. 7, in this embodiment, the fluctuation in tension of the web 80 when a disturbance is applied is about 3 N, and the conventional control is about 10 N, and when a disturbance is applied. It can be seen that the tension fluctuations of are greatly suppressed. Further, the tension fluctuation of the web 80 shown in FIG. 6 is about 1 N in the steady state, and the tension fluctuation of the web 80 shown in FIG. 7 is about 3 N in the steady state, and the tension control according to the present embodiment was performed. In this case, it can be understood that the tension fluctuation can be suppressed even in the steady state.

[0047]

According to the present invention, when a predetermined tension is applied to a continuously running web by a dancer roller, fluctuations in the tension of the web caused by the dancer roller moving from a predetermined position are suppressed. You can
As a result, excessive tension is not applied to the web, and the deterioration of the quality of the web can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of a tension control device of the present invention.

FIG. 2 is a configuration diagram showing an example of a configuration of a dancer roller device.

FIG. 3 is a diagram for explaining a force required to move a dancer roller 31 in the dancer roller device 30.

FIG. 4 is a diagram showing a state in which an arm 32 is tilted from a vertical direction at a tilt angle θ.

FIG. 5 is a diagram for explaining a thrust Fθ required to move the dancer roller 31 when the arm 32 is inclined at an inclination angle θ from the vertical direction.

FIG. 6 is a graph showing a result of measuring a tension fluctuation when the tension control device 1 controls the tension of the web 80.

FIG. 7: Web 8 with constant thrust of air cylinder 40
It is a graph which shows the result of having measured the tension fluctuation when 0 tension control was performed.

FIG. 8 is a diagram illustrating an example of a dancer roller device that adjusts the tension of the web by moving a weight.

FIG. 9 is a diagram showing an example of a dancer roller device that adjusts the tension of the web by the pressure of compressed air sent into an air cylinder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tension control device, 10 ... Reference roll part, 11 ... Reference roll, 20 ... Feed roll part, 21 ... Feed roll, 30 ... Dancer roller device, 31 ... Dancer roller, 32 ... Arm, 33 ... Support shaft, 34 ... Angle detector,
40 ... Air cylinder, 50 ... Control device, 80 ... Web.

Claims (8)

[Claims] 1. A tension control device for controlling the tension of a continuously running web to a set tension, comprising first and second running means provided in a running path of the web and running the web. A dancer roller around which the web running from the first running to the second running means is wound; an arm rotatably held about a predetermined support shaft and rotatably holding the dancer roller; A dancer roller device having an actuator that applies a predetermined force to the arm in a direction in which tension is generated on the web, the web being run at a predetermined speed, and the arm being at a predetermined position. First dancer for controlling the speed of the first and second traveling means to be positioned, and the dancer according to a rotation angle of the arm from the predetermined position. A second controller for controlling the force generated by the actuator so that the force acting on the web from the roller becomes constant. 2. The tension control device according to claim 1, further comprising an angle detector that detects a rotation angle of the arm and outputs a detection signal to the second control means. 3. The actuator comprises an air cylinder, and a pressure of compressed air supplied to the air cylinder to the second cylinder.
2. The tension control device according to claim 1, further comprising an electropneumatic converter that adjusts in accordance with a control command from the control device. 4. The correction means for correcting the force based on the weight of the arm and the dancer roller, which varies depending on the rotation of the arm from a predetermined position and acts on the actuator from the arm. The tension control device according to claim 1, wherein an amount is calculated, and the control command output to the actuator is corrected based on the correction amount. 5. A dancer roller around which a running web is wound, an arm rotatably held around a predetermined support shaft to rotatably hold the dancer roller, and tension is generated in the web on the arm. Is a tension control method for controlling the tension of a web that is continuously running by a dancer roller device that has an actuator that applies a predetermined force according to the set tension in a direction in which the web is run at a predetermined speed, and The force acting on the web from the dancer roller becomes constant according to the rotation angle of the arm from the predetermined position while the traveling control of the web is performed so that the arm is located at the predetermined position. A tension control method for controlling the force generated in the actuator. 6. The tension control method according to claim 5, wherein a rotation angle of the arm is detected by an angle detector provided on the support shaft, and the actuator is controlled based on the detected angle. 7. The tension control method according to claim 5, wherein an air cylinder is used as the actuator, and the pressure of the compressed air supplied to the air cylinder is adjusted using an electropneumatic converter. 8. A correction amount for correcting a force based on the weight of the arm and the dancer roller, which changes depending on the rotation of the arm from a predetermined position and acts on the actuator from the arm, and calculates the correction amount. The control command output to the actuator is corrected based on
The tension control method described in.