JPH03232002A - Dancer controller - Google Patents

Abstract

PURPOSE:To produce a sheet material of stable coating film thickness by calculating the allowable variable-speed rate of a coating roll corresponding to the carrying speed of a sheet material, and controlling a dancer correction signal corresponding to the allowable variable-speed rate. CONSTITUTION:An allowable variable-speed rate arithmetic circuit 16 calculates the allowable variable-speed rate per unit time of the coating roll 5 based on sheet material carrying reference outputted from a sheet material carrying speed reference setting circuit 7. A variable-speed rate limitation circuit 17 detects and compares the allowable variable-speed rate alpha1 and the variable-speed rate (alpha) of a speed correction signal that is the output of a position control circuit 12, and outputs the variable-speed rate (alpha) of the speed correction signal of the position control circuit 12 as it is when a result is within an allowable value (¦alpha¦<=¦alpha1¦). Also, when the result exceeds the the allowable value (when it is ¦alpha¦>¦alpha1¦), such limitation that the variable-speed rate of the speed correction signal of the position control circuit 12 goes to alpha1 is applied, and it is outputted to a correction width limitation circuit 13. In such a way, the speed command of the coating roll can be controlled within the allowable variable-speed rate even when steep position fluctuation occurs in a dancer roll 4.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to equipment for conveying sheet materials such as paper and films, and particularly relates to equipment for conveying sheet materials such as paper and films, and in particular, the present invention relates to equipment for conveying sheet materials such as paper and films, and in particular, the present invention relates to equipment for conveying sheet materials such as paper and films. The present invention relates to a dancer control device capable of suppressing.

(Conventional technology) FIG. 2 is a configuration diagram showing an example of a conventional control device.

In the figure, a sheet material 1 is subjected to various processing in a processing zone 2, and then transported by a transport roll 3, passed through a dancer roll 4, and then transported by a coating roll 5. The coating roll 5 coats the sheet material with the coating liquid. A tension control circuit 6 for keeping the tension of the sheet material constant in the processing zone 2 detects the sheet material tension deviation and outputs a speed correction signal to make the deviation signal zero. This correction signal is added to the reference speed of the speed reference setting circuit 7 that sets the speed reference of the sheet material to obtain the speed reference signal of the transport roll 3. The conveyance roll 3 is driven by an electric motor 8, and the rotation speed of this electric motor 8 is controlled by a speed control circuit 9 that controls the speed of the electric motor.
Thus, the speed is controlled to be equal to the speed reference of the transport roll 3. Then, the deviation between the position reference signal that is the output of the position setting reference circuit 11 and the position detection signal that is the output of the position detector 1O is input to the position control circuit 12. The position control circuit 12 outputs a speed correction signal to make the deviation signal zero. After the speed correction signal is limited within the allowable correction width by the correction width limiting circuit 13, it is added to the speed reference signal for conveying the sheet material and inputted as a reference to the application roll speed control circuit 14. Speed control circuit 1
4, the speed of the electric motor 15 that drives the coating roll 5 is controlled in accordance with the input signal.

In the conventional control device configured as described above, the position of the dancer roll 4 is determined by integrating the speed difference between the front and rear rolls, that is, the conveyance roll 3 and the application roll 5. Here, the speed of the conveyance roll 3 is the sum of the speed standard for conveying the sheet material and the tension correction signal of the processing zone 2, so as the tension correction signal changes, the position of the dancer roll 4 also changes accordingly. This position change signal is converted into a speed correction signal by the position control circuit 12 and added to the speed reference of the application roll 5. Therefore, the speed of the applicator roll also changes due to the change in the position of the tancer roll. On the other hand, when the speed of the coating roll 5 changes, the thickness of the film coated on the sheet material changes. Film thickness is an important parameter in terms of product quality, and it is necessary to keep the film thickness and the rate of change in film thickness in the longitudinal direction of the sheet material within tolerance values. However, in the conventional control device, by adding a limit to the speed correction signal that is the output of the position control circuit 12 and suppressing the speed fluctuation range of the coating roll 5, it was possible to keep the film thickness within the allowable value. However, it has been difficult to suppress the rate of change in film thickness in the longitudinal direction of the sheet material.

In other words, since the position control circuit 12 is composed of a proportional-integral calculation circuit, the rate of change of the speed correction signal that is the output of the position control circuit 12 is equal to or greater than the rate of change in the position of the dancer roll. become. For this reason, when the rate of change in position of the dancer roll is large, the rate of change in speed of the coating roll 5 also becomes large, and the rate of change in film thickness also has the drawback of exceeding an allowable value. Furthermore, it is possible to suppress the rate of change by reducing the proportional gain of the position control circuit I2 and applying integration, but this may result in poor control response and the allowable value of the rate of change depends on the base conveyance speed. However, since the control gain is fixed, it is difficult to optimally adjust the base conveyance speed over the entire range.

(Problems to be Solved by the Invention) As described above, in the conventional dancer control device, the rate of change of the speed correction signal exceeds the allowable value, and the rate of change in the longitudinal direction of the sheet material film thickness becomes abnormal. This caused variations in film thickness.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a dancer control device that can suppress variations and rate of change in sheet material film thickness regardless of the behavior of the dancer roll.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a dancer control device that keeps the position of the dancer roll constant, including a position detection means for detecting the position of the dancer roll; position correction calculation means for determining a dancer roll position deviation based on the signal from the position detection means and calculating a position correction signal;
The present invention is characterized by comprising: a rate-of-change calculating means for calculating a change width of the rate of change based on a speed reference signal; and a rate-of-change limiting means for comparing and determining the output of the position correction calculating means and the output of the rate-of-change calculating means. Provides dancer control.

(Function) In the device configured in this way, the permissible speed change rate of the application roll is calculated according to the conveyance speed of the sheet material, and the dancer correction signal is suppressed based on this, thereby controlling the sheet material within the permissible value. can.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of a dancer control device according to the present invention. In the figure, an allowable speed change rate calculation circuit 16 calculates the allowable speed change rate per unit time of the application roll 5 based on the sheet material conveyance speed standard output from the sheet material conveyance speed reference setting circuit 7.

Generally, the allowable speed change rate in the longitudinal direction of the sheet material is:
The width of change in speed per unit length of sheet material V (m
/S/ml. In order to convert this into a speed change rate α (acceleration) per unit time, the allowable speed change rate calculation circuit 16 calculates equation (1).

αmata = ± JV-VL... (1) Here,
αnu: Permissible speed change rate per unit time vL: Sheet material conveyance speed Also, is a positive value during acceleration and a negative value during deceleration.

Next, the speed change rate limiting circuit 17 calculates the allowable speed change rate α, which is the result of calculation using equation (1), and the position control circuit 12
Detect and compare the rate of change α of the speed correction signal which is the output of
If it is within the allowable value (1α1≦1αL +), the rate of change α of the speed correction signal of the position control circuit I2 is output as is, and if it exceeds the allowable value (1αl>1a, 11), the rate of change α of the speed correction signal of the position control circuit By limiting the rate of change of the speed correction signal to αy and outputting it to the correction width limiting circuit 13, even if the dance roll 4 undergoes sudden positional fluctuations, the speed command of 1-l is permissible. 3 (Effects of the Invention) As described above, according to the present invention, by configuring the allowable speed change rate calculation circuit and the change rate limiting circuit, the speed change rate of the sheet material can be controlled within a It is possible to calculate the permissible speed change rate of the coating roll according to the conveyance speed, and control the dancer correction signal according to this permissible speed change rate, thereby making it possible to produce a sheet material with a stable coating film thickness.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional dancer control device. 1-... Sheet material 3... Conveyance roll 4... Dancer roll 5... Application roll 6...Tension control circuit 7...Speed reference setting circuit 9.14...Speed control circuit 0...Position detector 2. ......Position control circuit 3...Correction width limiting circuit 6...Allowable speed change rate calculation circuit 7...
・・・・・・Speed change rate limiting circuit diagram diagram

Claims (1)

[Claims] A dancer control device that maintains a constant position of a dancer roll, comprising: a position detection means for detecting the position of the dancer roll; a position correction calculation means for calculating a position correction signal by determining a dancer roll position deviation based on a signal from the position detection means; , comprising a rate-of-change calculation means for calculating a change width of the speed change rate based on a speed reference signal, and a rate-of-change limiting means for comparing and determining an output of the position correction calculation means and an output of the rate-of-change calculation means. Features a dancer control device.