JP2000143053A - Tensile force control method for continuously running web and tensile force controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stable web conveyance without causing a slip of a bridle roller on a web conveying line. SOLUTION: On a web conveying line including a web winding machine 400 changing a tensile force of a web 100 continuously and a plurality of bridle sections 200, 300 having dancer roller devices 206, 306 adjusting a tensile force of the web 100, a tensile force to be given to the web 100 by the dancer roller devices 206, 306 of the bridle sections 200, 300 adjacent to the web winding machine 400 is continuously changed so that tensile force cut ratios of bridle rollers 202, 204, 302, 304 become the same based on tensile force of sections in the front and rear of the bridle sections 200, 300.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling the tension of a continuously running web, and more particularly to a section for continuously changing the web tension and a plurality of bridle sections having a dancer roller device for adjusting the web tension. The present invention relates to a tension control method and a tension control device for a continuous running web applied to a web transport line including:

[0002]

2. Description of the Related Art Generally, tension control of a continuous running web is performed by a dancer roller device in a bridle section. Conventional dancer roller devices of this type include those that adjust the tension of the web mainly by moving a weight, and those that adjust the tension of the web by the pressure of compressed air fed into an air cylinder.

As shown in FIG. 6, a dancer roller device for adjusting the tension of a web by moving a weight rotates a dancer roller 14 for wrapping a web 12 on the tip of an arm 10 rotatably provided in a vertical plane. Freely provided,
Further, by providing a weight 16 to the arm 10, tension is applied to the web 12 via the dancer roller 14.

On the other hand, a dancer roller device for adjusting the tension of the web by the pressure of the compressed air fed into the air cylinder wraps a web 24 on the tip of an arm 20 rotatably supported by a fulcrum 22 as shown in FIG. A dancer roller 26 is rotatably provided, and an air cylinder 28 to which compressed air is supplied is provided at the rear end of the arm 20 to apply a predetermined moment to the arm 20 and apply tension to the web 24 (for example, JP-A-59-4
557).

Further, there is known a dancer roller device capable of setting the tension of the web remotely and smoothly setting the tension in a stepless manner (JP-A-63-176259). That is, as shown in FIG.
And a weight 38 can be moved along the arm 30 by a driving unit 40 including an air cylinder 48 and
Further, the position control of the weight 38, that is, the tension setting of the web 32, is performed by a setter 52 that outputs an electric signal corresponding to the position of the weight 38 and an electropneumatic converter that converts an electric signal from the setter 52 into a pneumatic signal. The control is performed by adjusting the pressure of the compressed air sent out from the pressure reducing valve 46 of the driving unit 40 by the control unit 50 composed of 54. Note that reference numeral 6
Numeral 0 denotes an angle detector for detecting the angle of the arm 30. Based on a detection signal from the angle detector 60,
The web speed is adjusted so that is always kept horizontal. Also, by adjusting the pressure of the compressed air sent to the air cylinder 28 shown in FIG. 7 by a pressure setting signal,
Web settings can be remotely controlled.

Conventionally, the value of the web tension set by the dancer roller device is constant, and when the type of web is changed, the web tension is changed according to the type of web. Accordingly, even in a bridle section adjacent to a section where the tension of the web winder or the like continuously changes (hereinafter referred to as a tension change section), the tension applied to the web by the dancer roller device of the bridle section was constant.

However, when the tension applied to the web by the dancer roller device is kept constant as described above, the change in the tension in the tension changing section must be borne by the bridle roller of one bridle section adjacent to the tension changing section. However, there was a problem that slip occurred at the bridle roller. As a countermeasure against this, there is a method of increasing the number of bridle rollers in one section. However, in this case, the apparatus becomes large, and there is a problem in installation space, cost and maintenance. There is also a method of controlling the field or current value of a motor that drives the bridle roller according to the tension difference, and adjusting the load sharing ratio of the bridle roller. In this case, too, the load applied to one section of the bridle roller is also considered. Are the same, which limits the controllable range.

In Japanese Patent Application Laid-Open No. 3-61249,
Continuous running web tension control method capable of realizing stable web conveyance without slipping without changing the load due to web tension change without increasing the number of bridle rollers and without exceeding the control limit of the bridle rollers And a plurality of bridle sections having a section for continuously changing the web tension and a plurality of bridle sections having dancer roller devices for adjusting the web tension to provide a tension control device. Of these, the tension applied to the web by the dancer roller device at one or more bridle sections adjacent to the section where the web tension is continuously changed is determined based on the tension of the sections before and after the bridle section. Will be in the middle of the tension And so as to continuously change the.

[0009]

However, as described above, the load fluctuation due to the change in the tension of the tension change section does not concentrate on one bridle section, and the load on each bridle roller can be the same. However, the tension cut ratio of each bridle roller cannot be made the same, and there is a problem that slip occurs in the bridle roller.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tension control method and a tension control device for a continuous running web that can realize stable web conveyance without slippage of bridle rollers. Aim.

[0011]

According to the present invention, there is provided a web comprising a section for continuously changing the web tension and a plurality of bridle sections having a dancer roller device for adjusting the web tension. In the transport line, of the plurality of bridle sections, tension applied to the web by a dancer roller device of one or more bridle sections adjacent to a section that continuously changes the tension of the web,
The present invention is characterized in that the tension cut ratio of the bridle roller of the bridle section is continuously changed based on the tension of the section before and after the bridle section so that the tension cut ratio becomes the same tension.

According to the present invention, a load variation caused by a change in the tension of the section for continuously changing the tension of the web is borne by the plurality of bridle sections.
That is, the tension applied to the web by the dancer roller device of the bridle section adjacent to the tension changing section is continuously changed to the tension cut of the bridle rollers before and after the web. As a result, a load change due to a change in the tension of the tension change section does not concentrate on one bridle section, and it is possible to prevent the occurrence of a slip on the bridle roller of the section.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a continuous running web tension control method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing an example of a web transport line to which the present invention is applied. In the figure, the web 100 has two bridle sections 20
After passing through 0 and 300, the web is wound by the web winder 400.

The bridle section 200 includes bridle rollers 202 and 204 and a dancer roller 206. The bridle rollers 202 and 204 are driven by DC motors M1 and M2, respectively. That is,
A speed reference signal indicating the web feed speed, and a DC motor M
A detection signal indicating the actual web speed from the tacho generator 216 for detecting the rotation speed of the rotation speed 2 is added to an addition point 210, where a deviation of the two input signals is obtained, and a speed controller 212 for inputting the deviation signal. The DC motors M1 and M2 are controlled via the thyristor 214. Also,
Angle detection 2 for detecting the arm angle of dancer roller 206
The detection signal 08 is applied to the addition point 210 so as to always keep the arm supporting the dancer roller (see the arm 20 in FIG. 5) horizontal, and is used for adjusting the speed of the web.

On the other hand, the dancer roller 206
To adjust the tension applied to the tension setting device 220,
It is controlled by the electropneumatic converter 222 and the air cylinder 224. The tension setting device 220 is for setting the tension applied to the web 100, and is an electric signal V indicating the tension to be set.
₁ [V] is output to the electropneumatic converter 222. Electro-pneumatic converter 2
22 converts the input electric signal V ₁ into compressed air having a pressure corresponding to the electric signal, and supplies the compressed air to the air cylinder 224.

The air cylinder 224 applies a pressing force corresponding to the supplied compressed air to the dancer roller 206 so that the tension given to the web 100 by the dancer roller 206 becomes the tension set by the tension setting device 220. Similarly, the bridle section 300 includes bridle rollers 302 and 304 and a dancer roller 306. The bridle rollers 302 and 304 are driven by DC motors M3 and M4, respectively. These DC motors M3 and M4 are controlled similarly to the DC motors M1 and M2 of the bridle section 200 described above. That is, a speed reference signal indicating the web feed speed, a detection signal indicating the actual web speed from the tacho generator 316, and a detection signal indicating the arm angle of the dancer roller 306 from the angle detector 308 are added to the addition point 310. The addition output from the addition point 310 is output from the speed controller 3
12 and the DC motors M3 and M via the thyristor 314.
4 to control the DC motors M3 and M4.

On the other hand, the dancer roller 306 adjusts the tension applied to the web 100 by the pushing force from the air cylinder 324, similarly to the dancer roller 206. That is, the electric signal V ₃ [V] for setting the tension described later is converted by the electropneumatic converter 322 into compressed air having a pressure corresponding to the electric signal V ₃ , and this compressed air is
It is lined up for 4. The air cylinder 324 applies a pressing force corresponding to the supplied compressed air to the dancer roller 306,
The dancer roller 306 so as tension applied to the web 100 is tension set by the electrical signal V _3.

The web winder 400 is one of sections for continuously changing the web tension. The web winder 400 winds up the web 100 with a high tension at the beginning of winding, and the winding tension increases as the winding diameter increases. Is controlled to be continuously lower. That is, the tension reference generating circuit 402
The winding tension is set at 00, and an electric signal V ₂ [V] corresponding to the continuously changing tension is output. The electric signal V ₂ DC motor M5 via the current regulator 404 and the thyristor 406 based on is driven, the web winder 400 winds the web 100 in winding tension that varies according to the web winding diameter.

Next, the tension applied to the web 100 by the dancer roller 306 of the bridle section 300 will be described. An electric signal V ₁ for setting the tension of the dancer roller 206 output from the tension setter 220
And the electric signal V ₂ for setting the tension of the web winder 400 output from the tension reference generating circuit 402 is A
The signals are converted into digital signals D ₁ and D ₁ by / D converters 330 and 332 and are processed by a central processing unit (CPU) 33.
4 is output.

The CPU 334 calculates the geometrically averaged tension of the two set tensions based on the input digital signals D ₁ and D ₂ , and outputs a digital signal D ₃ indicating the geometrically averaged tension to the D / A converter 336. Output, D / A
The converter 336 converts the input digital signal D ₃ into an analog signal (electric signal V ₃ ) and converts the digital signal D ₃ into an electropneumatic converter 322.
Output to

As a result, the tension applied to the web 100 by the dancer roller 306 is the tension applied to the web 100 by the preceding dancer roller 206 and the tension applied to the web 100 by the subsequent web winder 400 (tension changing section). The tension is controlled so that the tension is a geometric mean of the tension.

[0022]

Next, an example of calculation in the CPU 334 will be described. It is assumed that the tension of the dancer roller 206 is set to N ₁ V ₁ [kg], the tension of the dancer roller 306 is set to N ₃ V ₃ [kg], and the tension of the web winder 400 is set to N ₂ V ₂ [kg]. Here, N ₁ , N ₂ , and N ₃ are constants, each of which is 10. Further, A / D converter _{330: V 1 → 10 × V} 1 = D 1 A / D comparator - motor _{332: V 2 → 10 × V} 2 = D 2 D / A converter _{336: D 3 → D 3/} 10 = the conversion of V ₃ is performed.

[0023]

The CPU 334 receives the input digital signal D ₁ ,
From D ₂ , the following equation is calculated: D ₃ = (D ₁ × D ₂ ) ^1/2 (1) Thus, the electric signal V ₃ output from the D / A converter 336 is

[0024]

[Number 2] _{V 3 = D 3/10 =} (D 1 × D 2) 1/2 / 10 = (10 × V 1 × 10 × V 2) 1/2 / 10 = (V 1 × V 2) 1 ^{/ 2} . Therefore, for example, the tension of the dancer roller 206 becomes

[0025]

## EQU3 ## V ₁ is set at 15 [V] constant, and the web winder 400 is

[0026]

V ₂ = 35− [2 (l−300)] / 70 [V] In the case where control is performed on the basis of tension expressed by the formula of [1: winding diameter (mm)], dancer rollers 206 and 306 are used. The tension pattern of the web take-up machine 400 is as shown in the table and graph of FIG.

As is clear from the table and the graph of FIG. 3, the bridle sections 200 and 300 are moved from the winding diameter l = 300 (mm) at the beginning of winding to the winding diameter l = 1200 (mm) at the end of winding. Bridle rollers 202, 204,
The tension difference borne by 302 and 304 is as follows: bridle section 200: 791--320 [N] load range 1111 [N] bridle section 300: 1209-252 [N] load range 1461 [N].

That is, the amount of change in tension at the start and end of winding of the web winder 400 is 2571 [N], and this amount of change in tension is shared by the two bridle sections 200 and 300 as described above. . It should be noted that if the set tension of the dancer roller 306 is kept constant as in the prior art, the web winding machine 400
The tension change amount of 2571 [N] is borne by only one bridle section 300.

Further, as compared with the case where the tension is continuously changed so as to be an intermediate tension between the front and rear tensions (FIG. 3), the cut ratio of the bridle roller is 1.667 to 1.528 at the maximum.
And the slip is less likely to occur. FIG. 4 shows a table and a graph of a tension pattern when the tension is changed so as to be a geometric average of the longitudinal tension.

FIG. 5 shows another embodiment of the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the embodiment shown in FIG.
The electric signals V ₁ and V ₂ for setting the tension of the dancer roller 206 and the web winder 400 are converted to the A / D converter 33.
0 and 332, which are input to the CPU 334 and used for the calculation. However, the actual tension of the dancer roller 206 and the web winder 400 may be different from the set tension due to a change in mechanical loss or a temperature drift of each control device. Conceivable.

In the embodiment shown in FIG.
06 and the actual tension in the web winder 400 are detected by tensiometers 340 and 342, respectively, and electric signals indicating these detected tensions are input to the CPU 334 via A / D converters 330 and 332, respectively. I have to.

[0032]

As described above, according to the continuous running web tension control method and the tension control device according to the present invention, a load change caused by a change in tension in a tension change section can be borne by a plurality of bridle sections. As a result, stable web transport without slips can be performed without increasing the number of bridle rollers and without exceeding the control limit of the bridle rollers.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a web transport system to which the present invention has been applied.

FIG. 2 is a chart and a graph showing tension patterns used for explaining the present invention.

FIG. 3 is a chart and a graph showing a tension pattern continuously changed so as to be an intermediate tension between front and rear tensions.

FIG. 4 is a chart and a graph showing a tension pattern in which longitudinal tension is changed so as to be a geometric average.

FIG. 5 is a configuration diagram of a web transport system showing another embodiment of the present invention.

FIG. 6 is an explanatory view showing an example of a dancer roller device.

FIG. 7 is an explanatory view showing an example of a dancer roller device.

FIG. 8 is an explanatory view showing an example of a dancer roller device.

[Explanation of symbols]

 100 web 200, 300 bridle section 202, 204, 302, 304 bridle roller 206, 306 dancer roller 220 tension setter 222, 322 electropneumatic converter 224, 324 air cylinder 334 central processing unit (CPU) 340, 342: tension meter 400: web winder 402: tension reference generation circuit

Claims (2)

[Claims] 1. A web transport line including a section for continuously changing the web tension and a plurality of bridle sections having a dancer roller device for adjusting the web tension, wherein the web tension among the plurality of bridle sections is reduced. The tension applied to the web by the dancer roller device of one or more bridle sections adjacent to the section to be continuously changed is reduced based on the tension of the sections before and after the bridle section. A tension control method for a continuously running web, wherein the tension is continuously changed so as to have the same ratio. 2. A web transport line including a section for continuously changing the web tension and a plurality of bridle sections having a dancer roller device for adjusting the web tension, wherein the web tension among the plurality of bridle sections is reduced. A dancer roller device for one or more bridle sections adjacent to a section to be continuously changed, wherein the dancer roller device sets a tension to be applied to a web in accordance with an input tension setting signal, and before and after the bridle section. Means for inputting a signal indicating a tension, calculating an intermediate tension that makes the tension cut ratio of the bridle roller of the bridle section the same, and outputting a tension setting signal indicating the calculated tension to the dancer roller device. Control of continuous running web Location.