JPH04341450A - Conveying tension control device for continuous body - Google Patents

Abstract

PURPOSE:To control a tension of a continuous body directly according to a detected value of tension of the continuous body. CONSTITUTION:A speed control part 4 calculates a difference between a set tension and a tension detected in a tension detecting part 2 proportionally, integrally, and differentially. Speed regulating signals are produced according to the values obtained by adding and deducting the calculated values to and from the speed detected in a speed detecting part 3, and output to a speed regulating part 1. A dancer control part 8 calculates a difference between a set value for rotational position of a dancer roller arm and a position detected in a position detecting part 7 proportionally, integrally, and differentially, and output rotating drive signals to a rotating drive part 6 according to the calculated values.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyance tension control device for a continuous object, which controls the conveyance tension of a continuous linear object or a belt-like object.

0002

[Prior art] Electric wire winding devices, paper, film, etc.
BACKGROUND ART In order to print on or process foils, thin steel strips, etc., devices that unwind, transport, wind, or cut these linear or web-shaped materials are widely used. In such cases, a certain tension is often applied to the wires or webs being transported.

FIG. 3 is a diagram showing a part of a printing apparatus having such a web unwinding device. The web 11 is unwound from the unwinding coil 12, and the dancer roll mechanisms 17, 18
, 19, 20, a tension detector 25, and an infeed roll 26 to be unwound. Unwinding coil 1
2 has an unwinding speed controlled by a servo motor 13, and the servo motor 13 is driven by a motor driver 14. The dancer roll swings around a rotation center 18 at one end of the lever 17, the web 11 is wrapped around a roll 19 provided at the other end of the lever 17, and the dancer roll swings by an air cylinder 23. The position detector 22 detects the swinging position of the roll 19. Air cylinder 23 is driven by an electro-pneumatic converter 24. The web 11 is driven by a roll of a printing unit that drives the web 11, and this driving source is a main motor 27, and a speed detector 29 for detecting the conveyance speed of the web 11 is provided on the drive shaft 28. The tension control device 10 inputs the outputs of the position detector 22 and the speed detector 29, controls the motor driver 14 and the electric air converter 24, and controls the tension of the web 11.

FIG. 7 shows an example of such a tension control circuit, and (a) shows a control circuit for the servo motor 13.
(b) shows the control circuit of the electric air converter 24. This control method detects the rotational position of the arm 17 of the dancer roll with a position detector 22, takes the difference 62 from the set position 61, performs a nonlinear calculation 63, and then performs a proportional, integral, and differential calculation 64.
After performing , the speed signal from the speed detector 29 and addition 59
and outputs it to the motor driver 14. The output of the tension detector 25 is displayed on the tension display section 54, the operator reads this value, determines the target tension of the web 11, sets 71 the air pressure of the air cylinder 23 to achieve this tension, and the air cylinder 23 is activated. The electric air converter 24
Control with.

[0005]

[Problems to be Solved by the Invention] In the case of the above-mentioned control method, the friction caused when the dancer roll swings, the moment of inertia of the swinging parts, and the friction of the gear 21 that meshes with the gear that constitutes the rotation center 18 of the arm 17 are reduced. Backlash and the like directly affect tension fluctuations of the web 11 as they are. If the arm 17 of the dancer roll does not swing, the servo motor 13
No corrective action takes place, and the stability of the tension in the web 11 depends largely on the mechanical properties of the components. As described above, since the above-described method uses an indirect control method of controlling the tension of the web 11 in controlling the rotational position of the arm of the dancer roll, mechanical malfunctions of the components of the dancer roll can be directly controlled. It has a negative impact on accuracy.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a conveyance tension control device for a continuum that directly controls the tension of the continuum based on the detected value of the tension of the continuum. do.

[0007]

Means for Solving the Problems FIG. 1 shows a diagram of the principle of the present invention. In the figure, 1 is a speed adjusting section that adjusts the conveyance speed of the continuous body, 2 is a tension detection section that detects the tension of the continuous body, 3 is a speed detection section that detects the conveyance speed of the continuous body,
4 performs proportional, integral, and differential calculations on the difference between the tension setting value and the tension detected by the tension detecting section 2, and generates a speed adjustment signal based on the value obtained by adding or subtracting this value to the detected speed of the speed detecting section 3. A speed control section 5 outputs output to the speed adjustment section 1, and 5 has one end of the arm as the rotation center and a roll at the other end, and the tension of the continuous body is adjusted by applying the continuous body to this roll and changing the rotation angle of the arm. A dancer roll to be changed; 6, a rotation drive unit that rotates the arm of the dancer roll 5; 7, a position detection unit that detects the rotational position of the arm of the dancer roll 5; 8, a rotational position setting of the arm of the dancer roll 5; The difference between the value and the detected position of the position detection section 7 is calculated by proportional, integral,
This is a dancer roll control section that performs differential calculation and outputs a rotational drive signal to the rotational drive section 6 based on this value.

Further, the position control speed of the dancer roll 5 performed by the rotary drive section 6 is controlled with a slower response than the conveyance speed control of the continuous body performed by the speed adjustment section 1.

Further, the speed control section 4 amplifies the difference between the tension setting value and the tension detected by the tension detection section 2 using a first nonlinear amplifier, and then performs proportional, integral, and differential calculations.

Further, the dancer roll control unit 8 amplifies the difference between the rotational position set value of the arm of the dancer roll 5 and the detected position of the position detection unit 7 using a second nonlinear amplifier, and then performs proportional, integral, and differential amplification. calculate.

Further, the first nonlinear amplifier has a large amplification degree when the input value is small, and a small amplification degree when the input value becomes large;
The second nonlinear amplifier is small when the input value is small;
The larger the value, the greater the degree of amplification.

0012

[Operation] The speed control section 4 performs proportional, integral, and differential calculations on the difference between the tension setting value of the continuum and the tension detected by the tension detection section 2, and amplifies the sum of this value and the detected speed of the speed detection section 3. Then, a speed adjustment signal is generated to control the speed adjustment section 1. The dancer roll control unit 8 performs proportional, integral, and differential calculations on the difference between the rotation position setting value of the arm of the dancer roll 5 and the detected position of the position detection unit 7, amplifies this value, and outputs a rotation drive signal. Controls the rotation drive unit 6.

By having two control loops of the dancer roll control section 8 and the speed control section 4 for controlling the dancer roll 5 to approximately the center position, sudden large tension fluctuations can be absorbed by the swinging of the dancer roll 5. However, fluctuations due to mechanical friction and rattling of the parts constituting the mechanism of the dancer roll 5 are controlled and corrected by the speed control section 4. By making the control response speed of the dancer roll control section 8 sufficiently slow, mutual interference can be avoided and control can be stably performed over a wide range.

The speed control section 4 amplifies the difference between the tension setting value and the tension detected by the tension detection section 2 using the first nonlinear amplifier, thereby making a sensitive correction for small fluctuations such as friction and backlash. Do not make unnecessary adjustments in response to large changes.
The vibration of the dancer roll is absorbed to stabilize speed control.

The dancer roll control section 8 controls the dancer roll 5
The difference between the rotational position set value of the arm and the detected position of the position detection section 7 is amplified by a second nonlinear amplifier.

The first nonlinear amplifier has amplification that is large when the input value is small and becomes small when the input value becomes large, and the second nonlinear amplifier has an amplification that is small when the input value is small and becomes large when the input value becomes large. The control of the speed control section 4 corresponds to short-term fluctuations and small fluctuations in tension, and the control of the dancer roll control section 8 corresponds to large fluctuations and slow fluctuations. The reason is that if the position of the dancer roll 5 is on average near the center, even if there is a sudden large tension fluctuation, the dancer roll can move within a wide range of motion and absorb the tension fluctuation. . Therefore, it is not necessary to strictly control the position as long as it is near the center.

[0017]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the control circuit of this embodiment, in which (a) shows the control circuit for the servo motor, and (b) shows the control circuit for the air cylinder. FIG. 3 shows a part of a printing device that implements this embodiment in unwinding tension control. In FIG. 3, reference numeral 10 indicates a tension control unit of this embodiment, and reference numeral 11 indicates a continuous web of paper, polyethylene sheet, or the like. 12 is web 1
1 is the unwinding coil, 13 is the unwinding coil 12
14 is a motor drive that drives this servo motor 13, 15 and 16 are diameter detection encoders for detecting the unwinding diameter of the unwinding coil 12, and 17 is a dancer roll. arm, 1
Reference numeral 8 is provided at one end of the arm 17, serves as a rotation center, and constitutes a large gear. 19 is a roll provided at the other end of the arm 17 to wrap the web 11 thereon. Reference numeral 20 constitutes a connecting portion of an air cylinder 23, which will be described later, provided at the intermediate portion of the arm 17, and 21 constitutes a pinion (small gear) of the gear 18, which determines the rotational position of the arm. 22 is a position detector that detects the rotational position of the connecting portion 20 from the rotational position of the pinion 21.

Reference numeral 23 denotes an air cylinder, and the tip of the rod engages with a connecting portion 20 of the arm 17 to swing the arm 17. 24 is an air cylinder 23 that converts the electrical signal into air pressure.
25 is a tension detector that detects the tension of the web 11, 26 is an infeed roll that guides the web 11 downstream, 27 is a main motor that serves as a drive source for conveying the web 11, and 28 is a main motor. The drive shaft 29 of the motor 27 is a speed detector that detects the conveyance speed of the web 11 from the drive shaft 28 .

Next, FIG. 2 will be explained. In the same figure, 51
52 is a subtractor; 53 is an amplifier that amplifies the detected value of the tension detector 25;
54 is a tension indicator that displays the output of the tension detector 25;
5 is a first nonlinear amplifier, which has a large amplification factor when the input value is small, and has a small amplification factor when the input value becomes large. 5
6 is a proportional/integral/differential calculator, 57 is a converter that converts the rotation signal output from the speed detector 29 into a voltage, 58 is an amplifier, 59 is an adder, and 60 is an amplifier.

61 is a position setting device for setting the rotational position of the arm 17 of the dancer roll, 62 is a subtracter, and 63 is a second nonlinear amplifier. When the input value is small, the amplification factor is small, and when the input value is large, the amplification factor is large. . 64 is a proportional/integral/differential calculator, and 65 is an amplifier.

Next, the operation will be explained. First, the air cylinder control circuit shown in FIG. 2(b) will be explained. The position of the connecting part 20 of the arm 17 of the dancer roll is detected by the position detector 22, the difference from the setting value of the position setting device 61 is taken by the subtracter 62, nonlinear amplification is performed by the second nonlinear amplifier 63, and the proportional・After calculating with the integral/differential calculator 64, 4 to 2
The current is input to an electric air converter 24 which converts the current into a 0 mA current and operates the air cylinder 23. This ensures that arm 1 of the dancer roll is
7 is always controlled to the set position.

Next, the servo motor control circuit shown in (a) will be explained. The tension of the web 11 is detected by the tension detector 25, the difference from the set tension set by the tension setting device 51 is taken by the subtracter 52, and after amplifying by the first nonlinear amplifier 55, the proportional/integral/differential calculator 56. The number of revolutions output from the speed detector 29 is converted into a voltage by a converter 57, and the value amplified by an amplifier 58 is added to a value obtained by proportional, integral, and differential calculations by an adder 59, and then amplified by an amplifier 60.
3 to the motor driver 14 that operates the signal. This control circuit controls the tension in the web 11 to match the tension setting.

In the integral calculation of the proportional/integral/derivative calculator 64 of the control circuit shown in (b), the response of the control speed of the position control of the dancer roll is determined by the response of the tension of the web 11 of the servo motor control circuit shown in (a). Set it so that it is sufficiently slower than the control response speed. As a result, if a large tension fluctuation occurs, it is absorbed by the swinging of the dancer roll. The small slow fluctuations control the servo motor 13 to keep the web 11 tension constant.

Due to the amplification characteristics of the first nonlinear amplifier 55,
Sudden tension fluctuations are absorbed by the swinging of the dancer roll, while small fluctuations such as friction and backlash are swiftly corrected, but when large fluctuations occur, speed control is stabilized by avoiding unnecessary corrections. . Due to the amplification characteristics of the second nonlinear amplifier 63, the dancer roll is maintained at a position near the center on average, the movable range of the dancer roll is widened, and even sudden large tension fluctuations can be absorbed.

As described above, the control of this embodiment can ignore tension fluctuation factors caused by mechanical factors such as friction of the dancer roll, inertia motor, and backlash of gears in position detection, and the advantages of the dancer roll and the tension detector 25 can be ignored. By using the output directly, it is possible to cope with sudden tension fluctuations and small tension fluctuations.

FIG. 4 shows a case where this embodiment is used for infeed tension control. In the figure, 30 indicates a printing unit. FIG. 5 shows a case where this embodiment is used for outfeed tension control. In this case, 59 shown in FIG. 2 becomes a subtracter, and outputs a value obtained by subtracting the output of the proportional/integrator/differentiator 56 from the output of the amplifier 58 to the amplifier 60. FIG. 6 shows the case where it is used for winding tension control. In the figure, 31 indicates an outfeed roll, and 32 indicates a winding coil. In this case, as in the case of FIG. 5, in FIG. 2, 59 acts as a subtracter,
The output of the proportional/differentiator 56 is subtracted from the output of the amplifier 58. In any of these tension controls, the present embodiment can be used almost as is.

[0027]

As is clear from the above description, the present invention detects the web tension, uses this tension to directly control the web tension, and also controls the position of the dancer roll to a predetermined position. Achieves control that can respond to small tension fluctuations, large tension fluctuations, sudden fluctuations, and slow fluctuations.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a control circuit diagram of this embodiment.

FIG. 3 is a configuration diagram of an apparatus for performing winding force control.

FIG. 4 is a configuration diagram of an apparatus for performing infeed tension control.

FIG. 5 is a configuration diagram of an apparatus for performing outfeed tension control.

FIG. 6 is a configuration diagram of an apparatus for controlling winding tension.

FIG. 7 is a diagram showing an example of a conventional tension control circuit.

[Explanation of symbols]

11 Web 12 Unwinding coil 13 Servo motor 14 Motor drive 17 Arm 18 Gear 19 provided at one end of the arm and serving as a rotation center Roll 20 provided at the other end of the arm Engagement portion 21 Pinion 22 engaged with the gear Position detector 23 Air cylinder 24 Electric air converter 25 Tension detector 29 Speed detector

Claims (5)

[Claims] 1. A speed adjusting section that adjusts the conveyance speed of the continuum, a tension detection section that detects the tension of the continuum, a speed detection section that detects the conveyance speed of the continuum, and a tension setting value and the a speed control section that generates a speed adjustment signal based on a value obtained by performing proportional, integral, and differential calculations on the difference between the tension detected by the tension detection section and the detected speed of the speed detection section, and outputs the signal to the speed adjustment section; and a dancer roll with one end of the arm as the rotation center and a roll at the other end, the continuous body being applied to this roll and the tension of the continuous body being changed by changing the rotation angle of the arm, and the arm of this dancer roll being rotated. a rotational drive unit that detects the rotational position of the arm of the dancer roll; and a position detection unit that detects the rotational position of the arm of the dancer roll, and performs proportional, integral, and differential calculations on the difference between the set value of the rotational position of the arm of the dancer roll and the detected position of the position detection unit. A conveyance tension control device for a continuous body, comprising: a dancer roll control section that outputs a rotational drive signal to the rotational drive section based on the tension value. 2. The continuous body according to claim 1, wherein the position control speed of the dancer roll performed by the rotary drive unit is controlled with a slower response than the conveyance speed control of the continuous body performed by the speed adjustment unit. Conveyance tension control device. 3. The speed control section amplifies the difference between the tension setting value and the tension detected by the tension detection section using a first nonlinear amplifier, and then performs proportional, integral, and differential calculations. Item 1. Continuum conveyance tension control device according to item 1. 4. The dancer roll control section amplifies the difference between the rotational position setting value of the arm of the dancer roll and the detected position of the position detection section using a second nonlinear amplifier, and then amplifies the difference between the rotational position setting value of the arm of the dancer roll and the detected position of the position detection section.
2. The conveying tension control device for a continuum according to claim 1, characterized in that integral and differential calculations are performed. 5. The first nonlinear amplifier has a small amplification when the input value is small and increases, and the second nonlinear amplifier has a small amplification when the input value is small and has a large amplification when the input value becomes large. The conveyance tension control device for a continuous body according to claim 3 or 4, characterized in that: