JP2001354342A - Control method of sheet transport tension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of easily and inexpensively controlling the tension of a sheet in carrying the sheet for controlling the tension of a continuous sheet carried from one roll to another roll in a prescribed range. SOLUTION: The tension of a sheet is detected, and the signal of the detected tension is converted to a contact signal. Then, based on the contact signal, a voltage signal of a roll B is increased/decreased, and the voltage signal of the roll B is converted to a speed command signal of a roll A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for controlling a conveying tension of a sheet.

[0002]

2. Description of the Related Art Conventionally, as a control method for adjusting a sheet tension when a continuous sheet is conveyed between rolls,
For example, an in-feed roll control method as shown in FIG. 4 has been put on the market. In this control method, plus relative tension T is T _0, in a way that can be controlled either case negative, established the powder brake and powder clutch infeed roll, by the powder brake controller control output, powder clutch Are driven by fixed power supplies, respectively. As a whole control operation, a negative torque bias is applied by a powder clutch and a positive torque bias is applied by a powder brake to control the tension.

However, in the above control method, the detected tension signal is input to a tension control device (controller) and analog feedback control is performed. Therefore, even when high control accuracy is not required, an expensive tension control device is required. (Controller) is used, resulting in a problem of high cost.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for controlling the tension of a sheet that can be controlled easily and inexpensively within a predetermined range, from the one roll to the other roll. To provide.

[0005]

A sheet transport tension control method according to the present invention is a control method for adjusting a sheet tension when a continuous sheet is transported from a roll A to a roll B, and detects the sheet tension. Then, the detected tension signal is converted into a contact signal, the voltage signal of the roll B is increased or decreased by the contact signal, and the voltage signal of the roll B is converted into a speed command signal of the roll A.

(Operation) The sheet transport tension control method of the present invention is a control method for adjusting the sheet tension when a continuous sheet is transported from the roll A to the roll B, and detects the sheet tension. The converted tension signal is converted into a contact signal, and the voltage signal of the roll B is increased or decreased by the contact signal.
By converting the voltage signal of the roll B into the speed command signal of the roll A, tension control can be performed with a simple device without requiring an expensive device.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

FIG. 1 is a block diagram showing the entire system of the sheet conveying tension control method of the present invention. In the figure, S indicates a sheet, 14 indicates a (control) roll A, 1 indicates a tension detector, and 15 indicates a (reference) roll B. First, the upper limit value Hi and the lower limit value Lo of the tension are input to the digital panel meter 3 in advance. The tension detection value measured by the tension detector 1 as the sheet S is conveyed is amplified by the tension meter 2 and input to the digital panel meter 3 as the actual tension.

When the tension is between Hi and Lo, when the reference roll 15 rotates at a predetermined speed in accordance with the line speed of the sheet S, the number of rotations read by the pulse generator 16 is converted by the converter 17. , As an analog signal proportional to the rotation speed, is input to an inverter 12 via a ratio setting device (variable resistor) 6. In response to a speed command signal from the inverter 12, the induction motor 13 rotates the control roll 14 at a predetermined rotation speed. The set value of the ratio setter (variable resistor) 6 varies depending on the characteristics of the sheet S to be conveyed, but it is usually desirable that the set value is apparently 100% of the speed of the reference roll 15. Normal,
The speeds of the reference roll 15 and the control roll 14 are constant when the set value of the ratio setting device (variable resistor) 6 is 100%, and there is no difference in tension between the conveyed sheets S.

However, when the set value is changed or when the sheet S
When the tension becomes larger than the upper limit value Hi of the digital panel meter 3 due to elongation of the digital panel meter 3, the relay contact 4 is activated and the contact 10 is connected, so that the line speed signal is output from the ratio setting device (variable resistor) 6 The signal is directly input to the inverter 12 from the circuit branched from the input side. The input signal at this time is input by the inverter 12 at a high voltage level without passing through the ratio setting device (variable resistor) 6,
The rotation speed of the control roll 14 is increased by the high-speed command from the control unit 2. This high-speed command is issued beforehand by the inverter 12 so that the rotation speed of the control roll 14 becomes 105 to 110%.
Adjust the connection ratio inside.

When the tension becomes smaller than the lower limit Lo of the digital panel meter 3, the relay contact 5 is activated, and the rotation speed signal is supplied to the ratio setting device (variable resistor) 6 in addition to the ratio setting device. (Variable resistor) 11, input to the inverter 12 at a low voltage level, and the inverter 1
The rotation speed of the control roll 14 is reduced by the low speed command from the second control command. This low speed command is set so that the rotation speed of the control roll 14 is 90 to 95%.

As described above, based on the result detected by the tension detector 1, the two-stage output (Hi _,
Lo), the voltage level input to the inverter 12 is changed to increase or decrease the rotation speed of the control roll 14, so that the tension of the sheet S can be maintained in the range between Hi and Lo. .

(Embodiment) An example applied to a cellophane tape production line will be described below with reference to FIG. Set the tension set value of the digital pamel meter 3 to Lo.
= 80 [N] and Hi = 100 [N]. When the system is turned on, the rotation speed of the reference roll 15 =
When it is 0 [m / min], the control roll 14 does not rotate. When the reference roll 15 is rotated, the control roll 1 is rotated.
4 also starts to rotate in synchronization with this, when the tension becomes smaller than Lo indicated by the digital panel meter 3, the relay contact 5 is activated, and the variable resistance ratio of the variable resistors VR1 and VR2 becomes the rotation speed signal. The multiplied voltage level signal is input to inverter 12.

Here, VR1 and VR2 are 0 to 2 k
Using a variable resistor of Ω, VR1 was set to 2 kΩ × 0.
95 = 1.9 kΩ, VR2 is set to 2 kΩ × 0.95 =
Assuming that 1.9 kΩ and the line speed signal is x [m / min], the input signal y to the inverter 12 is y = 12x × 0.
95 × 0.95 ≒ 0.90 × [m / min]. However, when Lo is set, as shown in FIG.
When the difference (12 × 0.05x) of (0.95-0.90) x is corrected and adjusted so as to be 12 × 0.95x, the rotation speed of the inverter 12 becomes 12 × 0.95x. Since the signal is supplied to the induction motor 13 and the rotation speed of the control roll 14 is reduced, the tension of the sheet S can be increased.

Next, when the tension value of the digital panel meter 3 becomes larger than Hi, the relay contact 4 is activated, and the line speed signal is directly input to the inverter 12. As described above, since the rotation is corrected in the inverter 12, the rotation speed of the control roll 14 becomes 12 × 1.05x, and the rotation speed increases, so that the tension of the sheet S can be reduced.

When the tension is within the above range, the line speed signal is input to the inverter 12 as a signal obtained by applying the ratio of VR1 by the ratio setting device (variable resistor) 6, and the reference roll 15 rotates at the rotational speed y = 12x × 1.00 [m / mi
n]. The acceleration / deceleration gradient is determined by the inverter 12
Can be adjusted in accordance with the characteristics of the sheet S. Here, both the acceleration time and the deceleration time are 60
The hunting phenomenon of the tension can be suppressed by setting the time to be relatively slow in seconds.

[0017]

According to the present invention, there is provided a method for controlling a sheet conveying tension.
With the above configuration, the tension of a continuous sheet conveyed from one roll to the other roll can be controlled at low cost by using a simple device. Therefore, it is suitably used for applications that do not require very high control accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an entire system of a sheet conveyance tension control method of the present invention.

FIG. 2 is a configuration diagram illustrating an entire system according to an embodiment.

FIG. 3 is a graph showing a relationship between a line speed of a sheet and a control roll.

FIG. 4 is a configuration diagram illustrating an entire system of a conventional sheet conveyance tension control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tension detector 2 Tension meter 3 Digital panel meter 4,5 Relay contact 6,11 Ratio setting device (variable resistor) 7,8,9,10 Contact 12 Inverter 14 Control roll 15 Reference roll 16 Pulse generator 17 Converter 18 Inverter

Claims (1)

[Claims] 1. A continuous sheet is rolled from a roll A to a roll B.
A control method for adjusting the sheet tension when the sheet is conveyed to the roller B, detecting the sheet tension, converting the detected tension signal into a contact signal, increasing or decreasing the voltage signal of the roll B by the contact signal, A method for controlling a sheet conveyance tension, comprising converting a voltage signal into a speed command signal of a roll A.