JPH0252845A - Web unreeling method and device - Google Patents

Abstract

PURPOSE:To prevent incurring of a web loss, to reduce the number of working processes, and to improve working efficiency by a method wherein when the number of webs is reduced to a given value, the web unreeled from a feed coil is nipped between a nip roller and a pass roller, and tension is exerted on the web. CONSTITUTION:When the number of windings of a feed coil 11 is increased to approximately 10 and this is detected, a control signal is outputted to a motor drive circuit 30 form a controller 32, and a line speed is switched to a middle speed. When the line speed is switched to the middle speed, an operation signal is outputted to a nip device 26 from the controller 32, and a nip roller 25 is brought into pressure contact with a pass roller 15 to nip a web 10 therebetween. By means of a command from the controller 32, a brake device 28 is gradually loosen a brake force, and reversely, a brake force by a motor 12 is reduced, correction of tension on a conveyance line on the whole is moved from the motor 12 to the brake device 28 from a point of time when a timing is slightly delayed. After elapse of a given time, correction is made by means of the device 28, and the web 10 is conveyed without being slacked.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of maintaining a constant tension during web feeding even near the end of web unwinding and after the end of the web leaves the unwinding shaft. The present invention relates to a web rewinding method and apparatus.

[Conventional technology]

For example, in a production line for PS plates, surface inspection, web curl correction, photosensitive material coating, etc. are performed while the aluminum web is transported at a constant speed. If the web becomes slack during such processing, the conditions for processes that rely on constant tension will change, and the web may slip in the conveyor line or cause unnecessary contact. Quality may become unstable. For this reason, conventionally, the tension of the web in the conveying line is maintained constant by adjusting the tortu of the sending coil that rewinds the web.

In this way, when trying to maintain a constant tension by controlling the torque of the unwinding coil, when the remaining amount of web on the sending coil decreases, it is not possible to maintain a constant tension by simply rotating the sending coil 1lfiff. unable to give. Therefore, there is a problem that the tension of the web decreases rapidly, especially near the end, and when the end of the web leaves the unwinding axis, the tension cannot be maintained at all. For this reason, conventionally, as known from Japanese Patent Application Laid-Open No. 60-244750,
A web thickness detector is used. This winding thickness detector accurately measures the winding thickness of the web on the sending coil, and stops the conveyance line when the winding thickness reaches a certain value (for example, about several turns). After the web is once held by the nip roller, the web is cut between the nip roller and the delivery coil. After cutting the web,
Replace the delivery coil with a new one with several webs remaining, connect the tip of the new web to the end of the web in the transport line, and operate the transport line again while adjusting the torque of the delivery coil. Let it restart.

(Problem to be Solved by the Invention) However, when the above method is used, the web is replaced with several turns of the web remaining in the sending coil, so the remaining web becomes a loss.Furthermore, the remaining web becomes a loss. must be removed from the coil core and disposed of, but this work is handled by the operator, which actually reduces the efficiency of the line's operation.

[Purpose of the invention]

The present invention has been made in order to solve the drawbacks of the prior art, and is a web rewinding method that eliminates the loss of the web itself, reduces the operator's work steps, and improves the operating efficiency of the web conveyance line. An object of the present invention is to provide a method and apparatus.

[Means to solve the problem]

In order to achieve the above object, the present invention sandwiches the web unwound from the delivery coil between a nip roller and a pass roller when the remaining amount of the web on the delivery coil is reduced to a predetermined amount. By applying tension to the web by at least one side, a constant tension is maintained with respect to the conveying line.

In addition, in order to realize the above method, there is a detector that detects when the remaining amount of web on the sending coil has reached a constant value, and a nip roller that is activated by a signal from this detector to sandwich the web between it and the pass roller. and a load supply means for applying a load to the rotation of at least one of the pass roller and the nip roller.

[Effect]

According to the above, the amount of web remaining on the sending coil decreases to a predetermined value, and the web tension fluctuation near the end, which cannot be corrected by torque control alone of the rewinding coil, and after the web end leaves the rewinding axis. It is now possible to compensate for fluctuations in web tension by applying braking to the web unwound from the sending coil via the nip roller and pass roller, making it possible to keep the web tension in the conveyance line almost constant as during normal operation. It is possible to keep it.

An embodiment of the present invention will be described below with reference to the drawings.

〔Example〕

In FIG. 1, which schematically shows an example of a web rewinding device using the present invention, the torque of a sending coil 11 formed by winding a long web 10 is controlled by a motor 12, and the braking torque of the motor 12 is The tension of the web 10 is determined correspondingly. Web 1 unwound from sending coil 11
0 is a termination detector 13.0 consisting of a photo sensor or the like. It reaches the decurler 17 via pass rollers 14 and 15 and further via a tension detection roller group 16. Note that the roller group 16 cooperates with a tension detector 18 to detect tension fluctuations of the web 10 in this web conveyance line, as will be described later. Further, the decurler 17 functions to remove the curling tendency that the web 10 has. A pair of feed rollers 22 are provided downstream of the conveyance line and are driven by a motor 20 at a constant rotational speed.

The web winding thickness of the sending coil 11 is monitored by a winding thickness detector 24 . The winding thickness detector 24, for example, as described in the above-mentioned publication, detects changes in the position of the surface of the sending coil 11 to obtain winding thickness data. The nip roller 25 is pressed against the pass roller 15 when the nip device 26 is activated, and the web 10 is held between both rollers. A brake device 28 is connected to the pass roller 15 so that it can brake the rotation of the pass roller 15. In addition, as the brake device 28,
In addition to a friction brake or the like, it is also possible to use a motor like the sending coil 11.

The motors 12.20 are driven by motor drive circuits 30.20, respectively.
It is controlled by a controller 32 via 31. Further, the operation of the nip device 26 is also controlled by a signal from the controller 32. The controller 32 receives the winding thickness data from the winding thickness detector 24 , the detection signal from the termination detector 13 , and the tension data from the tension detector 18 .

The controller 32 includes a line speed setter 33 that is preset operated prior to operation. A tension setting device 34 and a winding thickness data setting device 35 are connected to each other. The line speed setting device 33 has a high speed vI.

Medium speed v3. Three speed data of low speed v3 are set, and two winding thickness data of + and kz are set in the winding thickness data setter 35.

The operation of the above web feeding device will be explained with reference to the timing chart of FIG.

During normal operation, the motor drive circuit 30 is controlled via the controller 32 based on the speed data (2) set by the line speed setting device 33, and the web 10 is conveyed by the feed roller 22 at high speed.

During this time, the tension fluctuation is inputted to the controller 32 via the tension detector 18, and the controller 32 controls the braking torque of the motor 12 using the motor drive circuit 31. That is, the motor 12 is braked by controlling the braking torque of the motor 12 while the web 10 is being conveyed by the feed roller 22 at a constant speed V, and by adjusting the tension of the web 10 from the sending coil 11. The tension of the conveyance line can be maintained constant according to the setting value of the tension setting device 34.

In this way, by conveying the web 10 while maintaining a constant tension and passing it through the decurler 17, the curling habit of the web 10 is well corrected. Processing and photosensitive material coating can also be performed stably.

In the process of continuing normal operation, the winding thickness of the sending coil 11 is monitored by the winding thickness detector 24.
(about 10 revolutions), the controller 32 outputs a control signal to the motor drive circuit 30, and as a result, the line speed is switched to medium speed (v2). When the line speed becomes medium speed, an activation signal is output from the controller 32 to the nip device 26, and the nip roller 25 presses against the pass roller 15 to nip the web 10.

The web 10 is placed between the pass roller 15 and the nip roller 25.
When the transport line is clamped, the brake device 28 gradually increases the braking force according to a command from the controller 32, and conversely, the braking force by the motor 12 is weakened, so that the total tension on the conveyance line is maintained constant. . Further, tension correction for tension fluctuations gradually shifts from the motor 2 to the brake device 28 from time t2, which is slightly delayed from L+. Then, when a predetermined period of time has elapsed, the tension correction is completely transferred to the brake device 28, and the tension fluctuation detected by the tension detector 18 is corrected by the brake device 28 in accordance with the command from the controller 32. , the web 10 is conveyed without slack.

Further, the braking of the web 10 is also completely transferred from the motor 12 to the brake device 28 at timing t4.

When the winding thickness detector 24 detects that the winding thickness of the sending coil 11 has decreased to about 2 (about several turns), the controller 32 outputs a control signal to the motor drive circuit 30 again, and the line speed is reduced to a low speed. (v3). Even during this low-speed operation, tension correction is performed by the brake device 28 as is. When the end of the web 1o separates from the sending coil 11 and its passing is detected by the tail end detector 13 at a time point, the controller 32 sends a signal to the motor drive circuit 3.
A stop signal is output to 0, and the line operation is stopped.

After the operation is stopped, the operator removes the winding core of the delivery coil 11 and replaces it with a new delivery coil, joins the tip of the new web to the end of the web in the line, and then restarts the operation. Of course, when the operation is restarted, the line speed starts again at high speed (V,).

According to the above, it becomes possible to send out the web without leaving the web 10 on the sending coil 11,
If the arrangement of the pass roller 15 and the nip roller 25 is considered, it is possible to suppress the web loss to about 0.2 to 1 m. In addition, since no web is left on the sending coil 11, replacing the sending coil is easy, the working time can be reduced by about 4 minutes per coil, and working efficiency is improved.

In the above embodiment, the brake device 2 is attached to the bus roll 15.
Although the nip roller 25 or both of these rollers may be connected to a brake device for use. Furthermore, the present invention is applicable not only to lines that handle aluminum webs, but also to lines that handle webs of plastic, paper, and even various steel plates.

〔Effect of the invention〕

As explained above, in the present invention, when the web unwound from the sending coil is conveyed while maintaining uniform tension, when the remaining amount of the web on the sending coil reaches a predetermined value, the nip roller By sandwiching the web between the pass rollers and braking the rotation of these rollers to maintain a constant tension, the web can be completely unwound from the delivery coil, reducing web loss. It can be made very small.

As a result, the operator's man-hours when replacing the sending coil can be reduced, and the amount of waste (4° web to be discarded) can also be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a web rewinding device using the present invention. FIG. 2 is a timing chart showing the operation of the web rewinding device of FIG. 1. Web sending coil end detector Pass roller tension detector Winding thickness detector Nip roller Nip device Brake device. Procedural amendment February 2, 1999

Claims (2)

[Claims] (1) In the method of rewinding the web from the sending coil while maintaining a predetermined tension, when the web remaining in the sending coil decreases to a predetermined number of turns, the web unwound from the sending coil is transferred between the nip roller and the pass roller. By applying a rotational load to at least one of these rollers, a constant tension is maintained with respect to the web conveyance line even when the end of the web leaves the unwinding shaft. Web rewind method. (2) A delivery coil that rewinds the web while maintaining tension on the web conveyance line, a detector that outputs a control signal when the amount of web remaining in the delivery coil reaches a predetermined value, and the control signal A web unwinding method comprising: a nip roller which is operated by a feed coil and which sandwiches the web unwound from a sending coil with a pass roller; and a load supply means which provides resistance to the rotation of at least either the pass roller or the nip roller. Device.