JPH01176766A - Continuous web feeding device for plastic film, paper and the like - Google Patents

Abstract

PURPOSE:To hold a dancer roll in a specified position by connecting No, 1 and No.2 rotary encoders, a sensor, and No.1 and No.2 servo motors with a computer. CONSTITUTION:When the tension of a plastic film P varies and a dancer roll 1 rises or sinks slightly, this motion is sensed by a sensor 5, and a computer C receives a detection signal therefrom. The momentary rotation amount of No. 1 servo motor M1 increases or decreases slightly from a previously programmed value, and out of synchronization is generated between the No.1 and No.2 servo motors M1, M2. Accordingly the film feed amount by an upstream feed roller R1 will slightly increase or decrease from previously programmed value, and therefore the feed amount of the roller R1 must be adjusted. Thus the tension of the film P is adjusted properly, so that the dancer roll 1 will sink or rise to return to the original position. Thus the amplitude of the dancer roll 1 is minimized and can be held in specified position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a continuous web feeding device for feeding a continuous web of plastic film, paper, etc.

Structure of the Prior Art and its Problems Dancer rolls are widely used in continuous web feeding devices for plastic films, paper, etc. to apply tension to the continuous web. Typically, the dancer roll is located between an upstream feed roller and a downstream feed roller. The continuous web is then guided to an upstream feed roller, a dancer roll, and a downstream feed roller, and the continuous web is fed by the upstream and downstream feed rollers. Further, between the upstream and downstream feed rollers, the dancer roll is pressurized, for example by a cylinder, pressing the dancer roll against the continuous web and applying tension to the continuous web. Therefore, the cylinder pressure and the continuous web tension act on the dancer roll and balance each other. Furthermore, as the continuous web tension varies, the dancer rolls behave accordingly. Therefore, tension fluctuations in the continuous web can be controlled.

However, in this device, when the tension of the continuous web changes, the dancer roll cannot be operated indefinitely. Preferably, after each slight movement of the dancer roll, the tension in the continuous web is precisely adjusted to return the dancer roll to its original position and hold it in place. Therefore, attempts have been made to vary the amount by which the continuous web is fed by the feed roller upstream of the dancer roll. for example,
The upstream feed roller was transmission connected to a clutch and a drive motor, and when the dancer roll moved slightly, the clutch was disconnected by an operating mechanism. Therefore, the feed rate of the upstream feed roller changes temporarily, which adjusts the tension of the continuous web and
The roll returns to its original position. Thereafter, the clutch is connected by the operating mechanism, and the upstream feed roller is driven again.

However, conventionally there have been problems associated with the responsiveness of the clutch. It is not possible to disengage the clutch immediately, and it is inevitable that a certain amount of time delay will occur. moreover,
Even when the clutch is completely disengaged, the inertia of the clutch acts on the feed roller, which affects the feed rate of the continuous web. As a result, by the time the tension of the continuous web is properly adjusted, the dancer rolls have moved significantly and the amplitude of the dancer rolls has been large, making it impossible to hold the dancer rolls in a predetermined position.

Purpose of the Invention Therefore, the present invention has been made with the object of solving the above-mentioned conventional problems, accurately controlling the feed amount of the feed roller on the upstream side of the dancer roll, and holding the dancer roll in a predetermined position. It is something.

According to the present invention, the movement of the dancer roll is detected by the sensor. The upstream and downstream feed rollers are driven by the first and second servo motors. Further, first and second rotary encoders are provided on the first and second servo motors, and a computer is provided on the first and second servo motors.
and a second rotary encoder, which is connected to the sensor and the first and second servo motors, and the instantaneous rotational positions of the first and second servo motors are detected by the first and second rotary encoders. Then, the detection signals of the first and second rotary encoders are processed by the computer, the speed and acceleration of the first and second servo motors are estimated from the instantaneous rotational positions, and the deviation between the estimated values and the pre-programmed values is calculated. Based on the first step of the next step
and the instantaneous rotational position, velocity, and acceleration of the second servo motor are predicted, correction currents are provided to the first and second servo motors, and the first and second servo motors are each program controlled and synchronized with each other. Then, when the sensor detects the movement of the dancer roll, the instantaneous rotation amount of the first servo motor is slightly increased or decreased from a preprogrammed value, and the synchronization of the first and second servo motors is shifted.

Note that the first and second observers are connected to the first and second rotary encoders, and the first and second observers are made to observe the instantaneous rotational positions of the first and second servo motors, and their speed and load are estimated. This is preferable because it allows more accurate program control of the first and second servo motors.

Description of examples The present invention will be described in detail below.

In FIG. 1, this apparatus is for manufacturing plastic bags, and includes a dancer roll (1), upstream and downstream feed rollers (R1), (R2) and first and second servo motors. (Ml) and (M2). The upstream and downstream feed rollers (R1) and (R2) have the same diameter. And plastic film (P
) is the upstream feed roller (R1), dancer roll (1
) and the downstream feed roller (R2), and the upstream and downstream feed rollers (R1) and (R2) are driven by the first and second servo motors (Ml) and (M2). and downstream feed roller (R+), (R
2), the plastic film (P) is fed.

Furthermore, this device has a heat sealing device (2) and a cutter (3) for the plastic film (P), and the plastic film (P) has a dancer roll (1), a heat sealing device (2) and a cutter (3). , and is sent in fixed length increments. And plastic film (P)
Each time the film is fed by a certain length, the first and second servo motors (Mri, (M2), upstream and downstream feed rollers (R1), (R2) and plastic film (P
) will stop at that position. After that, the heat sealing device (
2) heat-seals the plastic film (P), and the cutter (3) heat-seals the plastic film (P).
P) is cut and a plastic bag is automatically produced.

Furthermore, the device has a cylinder (4) that pressurizes the dancer roll (1). Then, the cylinder (
4) pressurizes the dancer roll (1) and pushes it down, pressing the dancer roll (1) against the Plus Deck film (P). Therefore, tension is applied to the Plus Deck film (P). Furthermore, when the tension of the plus deck film (P) changes, the dancer roller (1) moves accordingly, raising or lowering. Therefore, tension fluctuations in the plastic film (P) can be alleviated. Furthermore, the device has a sensor (5), such as a limit switch. The sensor (5) is for detecting the movement of the dancer roll (1).

Furthermore, this device has first and second servo motors (Ml
), (M2) is controlled by a program (C)
has. Then, as shown in FIG. 2, the computer (C) has first and second servo motors (Ml),
)+7) Drive time (jl to j4), velocity (Vl) and acceleration (Vl/12-tl) are programmed.

Furthermore, this device has first and second rotary encoders (El), (R2), and the first and second rotary encoders (El), (R2) drive first and second servo motors (Ml), (M2). ) and a computer (C
) are the first and second rotary encoders (El), (R
2), connected to the sensor (5) and the first and second servo motors (Ml), (M2).

In this device, first and second servo motors (Ml
), (M2) receive the control current of the computer (C),
Programmed drive time (j+-j+), speed (Vl
) and acceleration (Vl/12-tl). Furthermore, the row reencoder (El), (R2)
The first and second servo motors (Ml), (M2
) is detected, and the computer (C) receives the detection signal. Then, the first and second rotary encoders (El), (R
The detection signal of 2) is processed, and the speed and acceleration of the first and second servo motors (Ml) and (M2) are estimated from their instantaneous rotational positions. Furthermore, based on the deviation between the instantaneous rotational position, velocity and acceleration of the first and second servo motors (Ml), (M2) and the values programmed in the computer (C), the first and second rotary encoders are then (Eri, the speed and acceleration of the first and second servo motors (Ml), (M2) at the time when (R2) detects the instantaneous rotational positions of the first and second servo motors (Ml), (M2) are predicted, the first and second servo motors (
A correction current is applied to Ml) and (M2). The first and second servo motors (Ml) and (M2) are each program-controlled and synchronized with each other.

Therefore, in the case of this device, the preprogrammed control currents are applied to the first and second servo motors (Ml), (
M2) as well as the computer (C)
The first and second servo motors (Ml), (M2
) are estimated and predicted, and the instantaneous rotational position, velocity and acceleration of the first and second servo motors (Ml), (M2) are estimated and predicted.
A correction current is applied to the control current, and the first and second servo motors (Ml) and (M2) are program-controlled by the control current and the correction current. Therefore, the first and second servo motors (Ml>, (M2) can be smoothly and accurately program-controlled and accurately synchronized. Therefore, the first and second servo motors (Ml) , (M2) drive the upstream and downstream feed rollers (R1), (R2), which can be precisely synchronized, and the upstream and downstream feed rollers (R1), (R2) drive the upstream and downstream feed rollers (R1), (R2). Plastic film (P) can be sent.

Then, the tension of the plastic film (P) changes,
When the dancer roll (1) makes a slight movement, rising or falling, the movement is detected by the sensor (5),
A computer (C) receives the detection signal. and,
The instantaneous rotation amount of the first servo motor (Ml) is slightly increased or decreased from a preprogrammed value, causing a synchronization difference between the first and second servo motors (Ml) and (M2). Therefore, when the plastic film (P) is fed by the upstream feed roller (R+), the feed amount slightly increases or decreases from a preprogrammed value. In the case of this device, the first and second servo motors (Ml) and (M2) can be accurately program-controlled, and the feed amount of the upstream feed roller (R1) can be adjusted.
It is easy to make a slight increase or decrease. Then, the feed amount of the upstream feed roller (R1) slightly increases or decreases from the pre-programmed value7, which is reflected in the tension of the plastic film (P), and the tension of the plastic film (P) increases. Accurately adjusted. therefore,
The dancer roll (1) is lowered or raised and returns to its original position. It is therefore possible to minimize the amplitude of the dancer roller (1) and keep it in place.

FIG. 3 shows an embodiment of Haku. This device is connected to the first and second
It has observers (01) and (02), and the first and second
Observers (01), (02) are connected to 'T%1 and the second rotary encoder (El), (R2), and the computer (C) is connected to the first and second observers (01),
(o2) and first and second servo motors (Ml),
(M2). Then, the instantaneous rotational positions of the first and second servo motors (Ml), (M2> are observed by the first and second observers (OI), (02), and their speeds and accelerations are estimated.Furthermore, the computer (C) by the first and second observers (0
The estimated signals of 1) and (o2) are processed, and based on the deviation between the estimated value and the pre-programmed value, the instantaneous rotational position of the first and second servo motors (Mri, (M2)) of the next stage is determined. , velocity and acceleration are predicted and the first and second
A correction current is given to the servo motors (Ml) and (M2). As a result, the first and second servo motors (Ml)
, (M2) can be more accurately program-controlled.

Furthermore, the device shown in Figure 3 is for feeding plastic film with a pattern printed on it.
The computer (C) is connected to the sensor (O). moreover,
As shown in FIG. 4, the computer (C) has first and second servo motors (Ml), (M2), (7)
), (v2) are programmed. Similarly, the first and second servo motors (Ml) and (M2) and the upstream and downstream feed rollers (R1) and (R2) are driven at high speed (V I )t'. , when stopping the plastic film (P) at a predetermined position, the first and second servo motors (Ml), (M2) and the upstream and downstream feed rollers (R1), (R2) operate at low speed (V2). When decelerated to
(R2) is driven at that speed (v2). Therefore, the plus deck film (P) is fed at a low speed. Then, the sensor (6) detects the plastic film (P).
) is detected and the computer (C) receives the detection signal (S), the first and second servo motors (
Ml), (M2), upstream and downstream feed rollers (
R1), (R2) and the plastic film (P) are further decelerated and stopped. Therefore, even if the plastic film (P) is stretched by tension and its length changes, the heat sealing device (2) and the cutter (
3) When heat-sealing and cutting the plastic film (P), the heat-sealing position and pattern of the Plus Deck film (P) can be related and matched, and the cutting position and pattern of the plastic film (P) can be related and matched. can be matched.

Note that this device is not limited to plastic film (P), and can also be applied to devices that feed continuous webs such as paper.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when the dancer roll is slightly raised or lowered, the tension of the plastic film is precisely adjusted, the dancer roll is lowered or raised, and returned to the original position 1. : Can be restored.

The lag of traditional clutches and their inertia do not occur.

Therefore, minimizing the amplitude of the dancer roll,
This can be held in a predetermined position and achieve the intended purpose.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of this invention, and FIG.
FIG. 3 is an explanatory diagram showing another embodiment, and FIG. 4 is a graph showing a control curve of the servo motor in FIG. 3. (P)...Plastic film (R1), (R2)...upstream and downstream feed rollers (Ml), (M2)...first and second servo motor (C)...... Computer (
El), (R2)...First and second rotary encoders (01), (02)...First and second observer Patent applicant Totani Giken Kogyo Co., Ltd. Figure 1 Figure 2vf! Figure 4

Claims (2)

[Claims] (1) A dancer roll is provided between the upstream feed roller and the downstream feed roller, and a continuous web of plastic film, paper, etc. is guided to the upstream feed roller, the dancer roll, and the downstream feed roller. In the device, the continuous web is fed by the upstream and downstream feed rollers, and tension is applied to the continuous web by the dancer roll, comprising: a sensor for detecting operation of the dancer roll; a first servo motor that drives a feed roller;
a first rotary encoder provided on the servo motor to detect its instantaneous rotational position; a second servomotor for driving the downstream feed roller; and a first rotary encoder provided on the second servomotor to detect its instantaneous rotational position. a second rotary encoder; the first and second rotary encoders;
connected to the sensor and the first and second servo motors, estimating the speed and acceleration of the first and second servo motors from their instantaneous rotational positions, and based on the deviation between the estimated values and preprogrammed values; , predicting instantaneous rotational positions, speeds and accelerations of the first and second servo motors in the next stage, applying correction currents to the first and second servo motors, and programming the first and second servo motors, respectively; control and synchronize with each other, and when the sensor detects the movement of the dancer roll, slightly increase or slightly decrease the instantaneous rotation amount of the first servo motor from a preprogrammed value;
and a computer for desynchronizing a second servo motor. (2) A dancer roll is provided between the upstream feed roller and the downstream feed roller, and a continuous web of plastic film, paper, etc. is guided to the upstream feed roller, the dancer roll, and the downstream feed roller. In the device, the continuous web is fed by the upstream and downstream feed rollers, and tension is applied to the continuous web by the dancer roll, comprising: a sensor for detecting operation of the dancer roll; a first servo motor that drives a feed roller;
a first rotary encoder provided on the servo motor to detect its instantaneous rotational position; and a first rotary encoder connected to the first rotary encoder to observe the instantaneous rotational position of the first servomotor and estimate its speed and acceleration. an observer; a second servo motor that drives the downstream feed roller; a second rotary encoder that is provided on the second servo motor and detects its instantaneous rotational position;
a second observer connected to a rotary encoder to observe the instantaneous rotational position of the second servo motor and estimate its speed and acceleration; the first and second observers, the sensor and the first and second servo motors; predicting instantaneous rotational positions, velocities, and accelerations of the first and second servo motors in the next stage based on deviations between the estimated values of the first and second observers and preprogrammed values; A correction current is applied to the first and second servo motors, the first and second servo motors are program-controlled and synchronized with each other, and when the sensor detects movement of the dancer roll, the first servo motor The instantaneous rotation amount of the motor is slightly increased or decreased from a pre-programmed value, and the first
and a computer for desynchronizing a second servo motor.