JPS63235244A - Device for rewinding film - Google Patents

Abstract

PURPOSE:To reduce variance in the tension of a film taken up by a drive roll by employing a control device for controlling the brake force of a brake device according to the output signal of a position detection device. CONSTITUTION:When the tension of a film 1 decreases, the film 1 between guide rolls 2 and 3 slackens, a position detection device 15 detects the slack and makes a control device 14 work, and the brake force of a brake device 12 is increased. As a result, rotation of a shaft core 9 is also braked and the rewinding tension of a roll-like film 10, namely the tension of the film 1, increases. When the film tension increases on the contrary, slack of the film 1 between guide rolls 2 and 3 due to suction forces by a suction device 7 decreases, the position detection device 15 detects the decrease in the slack to make the control device 14 work to reduce the brake force of the brake device 12. As a result, rotation of the shaft core 9 becomes easier and the rewinding force of the roll-like film 10, namely the tension of the film 1, decreases.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to improving a film rewinding device, and more specifically, the present invention is directed to an improvement in a film rewinding device, and more specifically, in cases where the winding core has an eccentric center or is wound. When the film is biased in the radial direction of the core, the present invention proposes a device that uses a fluid to reduce the change in tension during unwinding of the film that occurs each time the core rotates.

"Prior Art" Conventionally, a film rewinding device includes a guide roll, a rotational force variable device that changes the rotational force of a film core arranged on one side of the guide roll, and a rotational force variable device arranged on one side of the guide roll. a film tension detection device disposed on the side; a control device that controls the rotational force of the rotational force variable device in response to an output signal of the tension detection device; and a film surface between the guide roll and the core. Film rewinding device equipped with an air nozzle for blowing air
1258) is known.

However, since such conventional devices blow air onto the film, fine dust in the air is also blown onto the film and adheres to the film. Therefore, it cannot be used as a device for electrical insulation or video tape, which is extremely sensitive to dust.

Furthermore, even if it could be used, this device is equipped with an air nozzle that blows air onto the film surface between the guide roll and the core, so if the amount of film wrapped around the core changes, the amount of film against the core will change. Since the unwinding torque also changes, there was a drawback that highly accurate tension control was not possible.

[Means for Solving the Problems] The present invention consists of the following structures: (1) two guide rolls arranged at a predetermined interval; and a film conveyed between the two guide rolls. a suction device that sucks the film in a direction to give slack to the film; a braking device that applies a braking force to the rotation of a film core disposed on one side of the two guide rolls; a drive roll disposed on the other side that transports the film at a predetermined speed; a position detection device that detects the amount of slack in the film between the two guide rolls; A film rewinding device comprising: a control device for controlling the braking force of the braking device.

(2) Two guide 7-rules arranged at a predetermined interval,
A suction device that sucks the film in a direction to give slack to the film conveyed between the two guide rolls, and a rotation control of a film core disposed on one side of the two guide rolls. A braking device that provides power and the two guides l]
- a drive roll disposed on the other side of the roll for transporting the film at a predetermined speed, a film tension detection device disposed between the two guide rolls and the drive roll, and an output signal of the tension detection device; and a control device for controlling the braking force of the braking device in accordance with the above.

The main points are as follows.

The present invention is a film rewinding device, but if the film wound into a roll is left for a long time and the entire roll of film is biased in the radial direction of the core, one revolution of the core may occur. It is particularly advantageous to use the device according to the invention for the unwinding of such films, since the tension changes that occur each time the film is unwinded are extremely large.

[Examples and effects] Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic cross-sectional view of a film rewinding device, where 1 is a film (including a sheet), 2, 3 is a guide roll, 4 is a vacuum box, 5 is a duct pipe, 6 is a blower, and 7 is a vacuum box 4. , a suction device consisting of a duct pipe 5 and a blower 6, 8 a vacuum chamber, 9 a winding core, 10 a film wound in a 17-ring shape, 11 a power transmission means (belt, gear, etc.), and 12 a braking device. (friction brake, powder brake, etc.), 13 is a drive 17-rule, 14 is a control device, and 15 is a film position detection device (ultrasonic sensor, etc.).

As shown in the figure, two guide rolls 2.3 are arranged at a predetermined interval, and between the two guide rolls 2.3, the direction in which the film 1 being conveyed is slackened, that is, the vacuum A suction device 7 1-71 for sucking the film 1 is arranged on the chamber 8 side. The guide roll 2.3 may be rotatably supported, but is preferably driven by a motor or the like at a speed equivalent to the film transport speed.

In addition, as shown in the figure, slack in the present invention means that both 17-
This refers to a state in which the film length between the rolls is longer than ``1v1 raccoon'' between the axes of both rolls.

A core 9 of the L7-shaped film 1-0 is placed on one side of the two guide rolls 2.3, and the core 9 is supported by a core support (not shown). The winding core support is coupled to a braking device (powder brake) 12 via a power transmission means (belt) 11 .

Further, on the other side of the two guide rolls 2.3, there is disposed a drive roll 13 that conveys the filling at a predetermined speed.

A position detection device 1-5 for detecting the amount of slack in the film 1 is arranged above between the two guide rolls 2.3, and the control device 14 responds to the output signal of the position detection device 15. The braking force control of the braking device 12, that is,
Adjusts the braking force for film rewind.

In the apparatus of the present invention configured as described above, the film 1 unwound from the roll-shaped film 10 passes through the guide roll 2.3 and is taken up by the drive port 13, but when the tension of the film 1 becomes weak, As the film 1 between the guide rolls 2.3 is loosened by the suction force of the suction device 7, the position detection device 15 detects this and operates the control device 14 to increase the braking force of the braking device 12. The rotation of the core 9 is also braked, and the film unwinding tension of the 11-element film 10, that is, the tension of the film 1, increases. Conversely, when the tension of the film 1 increases, the slack of the film 1 between the guide rolls 2 and 3 due to the suction force of the suction device 7 becomes smaller, so the position detection device 15 detects this and activates the control device 14. Since the braking force of the braking device] 2 is reduced, the rotation of the shaft core 9 is facilitated, and the fill of the roll film 10 is reduced. , the tension of the film 1 becomes lower after unwinding.

Therefore, by appropriately selecting the suction force of the suction device 7 and the braking force of the brake bag 212 connected to the shaft core 9, the tension of the film 1 can be set. Since the control is performed as described above by detecting the position of the film 1, the tension can be controlled with extremely high precision, and the unwinding tension of the film 1 can be kept constant.

FIG. 2 is an explanatory diagram of the film slack between the guide rolls 2.3, where C indicates the position of the center of the radius of curvature of the film slack between the guide rolls 2.3, and D indicates the center position of the film slack between the guide rolls 2.3.
．． This is the line that connects both axes of 3.

Figure 4 shows the roll 2.3 for position C shown in Figure 2.
The relationship between the film tensions was calculated based on the following formula.

The calculation formula is 'p=pd.

T: Film tension p between rolls 2.3; Pressure difference between the inside and outside of the suction device d: Radius of curvature of slack in the film between rolls 2.3゛ (Not shown in Figure 4) The position of D is shown in Figure 2. It shows that the position of C shown by is on the line of D. The more leftward you go from D in Figure 4, the further away the position of C shown in Figure 2 is from the line. shows that the line (■) gradually moves further downward.

The position of the center C shown in FIG. 2 moves up and down in the figure during the film rewinding operation, and the position of the center C shown in FIG.
When the tension of the film 1 is above the line connecting the re-rotation central axes of 3, the lower the position of the center C is, that is, the further the tension of the film 1 is from the left side toward D in FIG. When the position of C is below the line, the lower the center C is, that is, the further rightward from D in FIG. 4, the higher the tension of the film becomes.

It is preferable to set and operate the variable range of the center C to be above the line because the controllability in the rewinding operation of the film 1 becomes more stable.

Further, it is preferable to set the variable range of the center C to be above the line and operate the film as described above, since the length of the film in the slack portion is shortened, thereby reducing the occurrence of wrinkles.

FIG. 3 does not show the winding device of the present invention in which the tension change corresponding to the slack of the film in FIG. 1 is directly detected by a tension detection device. The tension detection device 1-15 is the same as in FIG.

In the figure, as the position of the center C moves up and down, the tension of the film 1 changes. This change in tension is detected by the film tension detector 16, and the detection signal is used to operate the control device 14 to increase the braking force of the braking device 12. At the same time, by changing the braking force for rotation of the shaft core 9, it is possible to control the film unwinding tension of the roll film 10 to be constant.

Note that the rotation speed of the shaft core 9 is measured and the roll-shaped film 10 is measured.
Alternatively, the diameter of the roll film 10, film thickness, mechanical loss, and film conveyance speed are calculated in advance and a signal corresponding to the diameter of the roll film 10 is obtained from the relationship with time. It is also possible to correct the control of the control device 14 using a signal corresponding to this diameter, thereby increasing the control accuracy of the braking device.

Next, an example of a rewind test using the apparatus of the present invention will be described.

Examples 1 and 2, Bisame Examples 1 and 2 An unwinding test was conducted using the apparatus shown in FIG. 1 under the conditions shown in Table 1.

The results of measuring the tension of the film in this test are shown in FIGS. 5 to 7.

Hereinafter, FIGS. 5 to 7 will be explained.

The tension measurement results shown in FIG. 6 are those of Comparative Example 1. That is, the tension was measured with a 1g core of 1.5 mm given to the winding core, and with the pressure in the vacuum chamber of the suction device in the device of the present invention being equal to the external pressure, that is, without operating the suction device. It is.

As you can see from the graph, the tension is ±3°5 with an average of 7kg/m.
It shows a fluctuation of about kg/m.

The tension measurement results shown in FIG. 5 are those of Example 1. That is, the tension was measured by giving an eccentricity of 1.5 mm to the winding core and setting the pressure in the vacuum chamber of the suction device of the apparatus of the present invention to be 30 JI 1 m80 lower than the pressure outside the vacuum chamber. As you can see in the graph, the tension is 7ks.
The variation in tension was about 9/m to ±1.5 on average, which was about half of the variation in tension in Comparative Example 1.

The tension measurement results shown in FIG. 7 are those of Comparative Example 2. That is, the tension of a film with almost no eccentricity in the winding core was measured while keeping the pressure in the vacuum chamber of the suction device in the apparatus of the present invention the same as the external pressure. As you can see from the graph, the tension is ±1.7kv/m on average.
It fluctuates within a range of about 25 kq/m.

As is clear from the results of these tension measurements, even if there is eccentricity in the winding core, it is possible to reduce tension fluctuations by using the device according to the present invention.

As Example 2, a test was conducted in the same manner as in Example 1 except that the apparatus shown in FIG. 1 was replaced with the apparatus shown in FIG.

As a result, effects comparable to those of Example 1 shown in FIG. 5 were obtained.

The device of the present invention adjusts the braking force of the winding core by control based on the slackness of the film formed between the two guide rolls, so that the stable tension as shown in Example 1 can be maintained during unwinding. You can rewind from the beginning to the end.

Effects of the Invention] As described above, the present invention controls the braking force of the two guide rolls, the suction device, the braking device, the drive roll, the position detection device or the tension detection device, and the braking device. Since the film rewinding device is equipped with a control device,
It has the following excellent effects.

When the winding core is eccentric, especially when the fillet wound around the winding core is eccentric in the radial direction of the winding core, the driving weight 1
- It is possible to reduce tension fluctuations in the film taken up by the roll. Therefore, the tension of the film carried into the next process, for example, the winding process, is stabilized, and a package with few winding defects can be obtained. Furthermore, since air is not blown onto the film, fine dust does not adhere to it.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the film rewinding device of the present invention in which a film position detection device is used as a detector, FIG. 2 is an explanatory diagram of film slack, and FIG.
FIG. 2 is a schematic cross-sectional view when a film tension detection device is used as a detector in the film rewinding device of the present invention. FIG. 4 shows changes in the tension of the film between the rolls 2 and 3 due to changes in the position of C, determined by a calculation formula. Figures 5, 6, and 7 are Example 1 and Ratio Example 1, respectively.
, shows the tension measurement results of Comparative Example 2. 1: Film 2.3: Guide roll 4: Vacuum box 5: Duct pipe 6: Blower 7: Suction device 8: Vacuum chamber 9: Core 10: Film wound into a roll 11: Power transmission means 12: Braking device 13: Drive roll 1.4: Control device 15: Film position detection device 16: Film tension detection device

Claims (2)

[Claims] (1) Two guide rolls arranged at a predetermined interval, a suction device that sucks the film conveyed between the two guide rolls in a direction that gives slack to the film, and the two guide rolls. a braking device disposed on one side of the roll to apply a braking force to the rotation of the film core; a drive roll disposed on the other side of the two guide rolls for transporting the film at a predetermined speed; and a drive roll disposed on the other side of the two guide rolls; A film rewinding device comprising: a position detection device for detecting the amount of slack in the film between the guide rolls; and a control device for controlling the braking force of the braking device in response to an output signal of the position detection device. . (2) two guide rolls arranged at a predetermined interval; a suction device that sucks the film conveyed between the two guide rolls in a direction that gives slack to the film; and the two guide rolls. a braking device disposed on one side of the roll to apply a braking force to the rotation of the film core; a drive roll disposed on the other side of the two guide rolls for transporting the film at a predetermined speed; and a drive roll disposed on the other side of the two guide rolls; A film roll comprising a film tension detection device disposed between a guide roll and a drive roll, and a control device for controlling the braking force of the braking device in response to an output signal of the tension detection device. Return device.