JPH0826552A - Method and apparatus for preventing excessive tension of web - Google Patents

Abstract

(57) [Summary] [Purpose] Excessive tension of the web that does not cause deformation or damage to various equipment and devices even if tension above a specified value acts on the web transported in one direction. A prevention method and an apparatus therefor are provided. [Structure] When an excessive tension acts on the web W being transferred, the tension applying rolls 7 and 8 instantaneously move upward,
The web W is collided with the cutting device 15 to cut it.
By doing so, the excessive tension is eliminated and the equipment and devices are not damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when continuously transferring a belt-shaped web of paper, synthetic resin film, woven fabric, metal foil, etc. in one direction, its tension becomes excessive and deforms equipment and devices. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for preventing excessive tension of a web for preventing it from being damaged or broken.

[0002]

2. Description of the Related Art Conventionally, a web of paper, a synthetic resin film, a woven fabric, a metal foil, etc. is continuously transferred in one direction while being wound or unwound, and secondary processing such as printing or laminating is performed. For example, the tension of the web changes as the winding diameter changes. Then, it causes wrinkles, sagging, change in thickness, and the like. Therefore, in order to keep the tension constant or within a constant range, a tension adjusting device is installed in the course of traveling of the web.

An example of such a tension adjusting device is schematically shown in FIG. In the figure, W is a web, and a and b are drive rolls having motors c and d as drive sources, respectively.
The web W is continuously transferred to the right in the figure by the drive of the drive rolls a and b. Roll e with a tension detection sensor consisting of three rolls between the drive rolls a and b
Is installed, and the tension during this time is detected. And
The motor c on the side of the drive roll a and the tension detection sensor of the roll e are controlled by the controller f.

When the web W whose tension is kept within a certain range is running, if an excessive tension above the upper limit value acts, when the tension reaches the upper limit value within a certain range, first, the tension detecting sensor of the roll e is detected. Detects it and sends a signal to the controller f. Upon receiving this signal, the controller f transmits the electric power adjusted according to the signal to the motor c to make the rotation speed of the drive roll a faster than that of the drive roll b. Then, the tension of the web W between the drive rolls a and b becomes small and falls within a certain range. On the contrary, when the tension reaches the lower limit of a certain range, the rotation speed of the drive roll a is set lower than that of the drive roll b, the web W
Since the tension of the is increased, it can be kept within a certain range.

[0005]

However, in the case of the above-mentioned conventional apparatus, the tension detecting sensor detects an abnormality in the tension of the web W and transmits it to the controller f, and controls the motor c based on this signal. Has a time lag,
If the tension suddenly suddenly becomes abnormal, especially if the tension becomes excessive, the tension adjusting device cannot respond in a timely manner.
The web W breaks. Since the tension of the web W at this time has reached or exceeded the tensile load of the web W and is an impact load, for example, in the case of a woven fabric having a width of 1 m, a load of about 7 tons is applied. It leads to deformation and destruction of various facilities and equipment on the route.

The present invention solves the above-mentioned problems of the prior art, and deforms various facilities and equipment even if excessive tension acts on a web which is being fed with a certain tension or a certain range of tension applied thereto. The object of the present invention is to provide a method and apparatus for preventing excessive tension of a web that does not break or break.

[0007]

According to the first aspect of the present invention,
"When the web is applied with a predetermined tension or more while being transported in one direction with a predetermined tension applied to the web,
A method of preventing excessive tension of a web characterized by cutting the web "is a gist thereof,

According to a second aspect of the present invention, "a fixed roll disposed at a predetermined position in front of and behind the web in the transfer direction of the web, and a fixed frame for supporting the fixed roll,
It is arranged at a fixed position in the transfer direction between the fixed frames, and has a tension applying roll for applying a predetermined tension to the web, and the tension applying roll has a restoring force by applying a tension of a predetermined value or more to the web. When it is used, it can be moved in a direction intersecting the transfer direction by the restoring force of the web, and the web can be cut at a fixed position in the transfer direction between the fixed frames by utilizing the restoring force of the web. The gist of the invention is "a device for preventing excessive tension of a web, which is equipped with a cutting device".

In the present invention, the "predetermined tension" includes not only the tension having a constant value but also the tension having a value having a certain range of width. Therefore, “tension equal to or more than a predetermined value” includes not only tension equal to or more than a certain value but also tension indicating an upper limit value of tension having a width in a certain range.

[0010]

According to the method of preventing excessive tension of a web of the present invention, the web is cut when a tension of a predetermined value or more is applied to the web while the web is being transferred under a predetermined tension. With a simple operation of cutting, the tension of the web becomes 0 without exceeding a predetermined value.

According to a second aspect of the present invention, there is provided a device for preventing excessive tension of a web, which comprises a fixed roll, along which the web can move, before and after the web in the transport direction, and a tension imparting force for applying a predetermined tension to the web. A roll is provided, and when the web is subjected to an excessive tension of a predetermined value or more, a restoring force of the web, that is, an excessive tension-a predetermined tension, is a direction intersecting the transfer direction. The function of moving the web is provided, and a cutting device for cutting the web by utilizing the restoring force of the web is provided. Is disconnected.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram schematically showing an example of a web overtensioning prevention device of the invention according to claim 2, and FIG. 2 is a diagram schematically showing a moment of cutting the web by the device of FIG. FIG. 3 is a perspective view showing a part of the apparatus of FIG. 1 taken out.

In FIG. 1, W is a web that passes through the inside of the apparatus and is continuously transferred in the direction of the arrow. 1 and 2 are fixed rolls, 3 is a fixed frame, a lower frame 4 framed in a rectangular shape, and a rectangular support set upright at both edges of the lower frame 4 in the transfer direction (left and right direction in the drawing). It is composed of frames 5 and 6. Bearings (not shown) are attached to the upper portions of the support frames 5 and 6, and the fixed rolls 1 and 2 are attached to the bearings and are freely rotatable by contact with the web W.

Reference numerals 7 and 8 denote tension applying rolls. As shown in FIG. 3, the tension applying rolls 7 and 8 are movable frames 9 and 1.
It is attached to both ends of 0 and can be freely rotated by contact with the web W, like the fixed rolls 1 and 2. 1
Reference numerals 1 and 12 are U-shaped guide rings attached to the middle portions of the moving frames 9 and 10, and 13 and 14 are strip-shaped guide plates that are erected substantially in the middle of the lower frame 4 in the transfer direction. There are guide rings 11 and 12
Is slidable in the vertical direction (arrow direction in FIG. 1) along the guide plates 13 and 14 with low friction. Therefore, the tension applying rolls 7 and 8 are moved by the guide of the guide plates 13 and 14. As the frames 9 and 10 move in the vertical direction, they can also move in the vertical direction.

A constant tension T is applied to the traveling web W by the combined weight of the tension applying rolls 7 and 8, the moving frames 9 and 10 and the guide rings 11 and 12. . In addition, when it is desired to change the tension T as appropriate, a fixing tool such as a screw or a bolt is used for the tension applying rolls 7, 8, the moving frames 9, 10, or the guide rings 11, 12.
The weight can be attached as appropriate.

Reference numeral 15 denotes a cutting device composed of a cutting blade,
The cutting device 15 is provided with a mounting frame 1 installed between the support frames 5 and 6 slightly below the fixed rolls 1 and 2 in the transfer direction.
It is attached to 6, 17.

FIG. 1 shows a procedure for carrying out the method of the invention described in claim 1 by using the apparatus of the invention described in claim 2.
~ It demonstrates with reference to FIG.

The predetermined tension T applied to the web W is
It is set mainly by the material and thickness of the web W. For example, assume that the tension T required by the web W in this embodiment is 70 kg. Moreover, the limit of the tension at which this transfer device is not deformed or damaged is 2 tons. Also,
If the load when the web W is torn apart by excessive tension is about 7 tons, the predetermined tension is 70 to 200.
It may be set appropriately between 0 kg.

On the other hand, the members involved in applying the tension to the web W in this embodiment are, as described above, the tension applying rolls 7, 8, the moving frames 9, 10 and the guide rings 11, 12 and appropriately attached. Determined by the combined weight of the weights. However, it takes some time to replace the members other than the weight, so the weight without weight is set to 70 kg,
In the following, it is preferable that a plurality of weights can be attached each time the weight is increased by 50 kg, because the number of required members is small and the workability is excellent.

By the way, a predetermined tension is set to 70 kg, no weight is attached to the apparatus, and the web W is transferred through the fixed roll 1, the tension applying rolls 7 and 8 and the fixed roll 2 in this order as shown in FIG. To start, when the web W is being transported normally, the tensioning rolls 7 and 8 are in equilibrium at the positions shown in FIG. 1, but at some point, for example, when an over tension of 2 tons is applied. The tension applying rolls 7 and 8 do not withstand the excessive tension and are instantly raised to the position shown in FIG. After the cutting, the web W has no tension, and the tensioning rolls 7 and 8 naturally drop to the lowest position.

In the above-described embodiment of the invention described in claim 2, an example in which a constant tension is given as the predetermined tension has been shown. For example, when a dancer roll is used as the tension imparting roll, the tension within a certain range is obtained. It can be used also when giving.

In the above-described embodiment of the invention described in claim 2, as members involved in applying tension to the web W, the tension applying rolls 7 and 8, the moving frames 9 and 10 and the guide rings 11 and 12 are included. An example is shown, but as a participating member, a device comprising one tensioning roll and two wires that are stretched between both ends of this roll and the lower frame 4 and are torn off by excessive tension. Alternatively, the tension of the web W may be the total of the weight of the one tension applying roll and the tensile strength of the two wires.

In the above embodiment, the cutting device is
Although the example using the cutting blade is shown, the invention is not necessarily limited to this, and a nichrome wire that is energized for a predetermined time during cutting may be used.

[0024]

According to the method of preventing excessive tension of a web according to the present invention, the web is cut when a tension of a predetermined value or more is applied to the web while the web is being transferred under a predetermined tension. Therefore, the tension of the web becomes 0 without exceeding a predetermined value by a simple operation of cutting. Therefore,
The excessive tension acting on the web will not deform or damage the equipment and devices.

According to a second aspect of the present invention, there is provided an apparatus for preventing excessive tension of a web, wherein a fixed roll, along which the web can move, is provided before and after the web in the transport direction, and a tension is applied to apply a predetermined tension to the web. A roll is provided, and when the web is subjected to an excessive tension of a predetermined value or more, a restoring force of the web, that is, an excessive tension-a predetermined tension, is a direction intersecting the transfer direction. Since the web is provided with a cutting device capable of cutting the web by utilizing the restoring force of the web, when the web is tensioned with a predetermined value or more, the web is timely. Is disconnected. Therefore, the apparatus is suitable for use in carrying out the invention described in claim 1.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of a web excessive tension preventing device according to a second aspect of the present invention.

FIG. 2 is a diagram schematically showing the moment when the web is cut by the same apparatus.

FIG. 3 is a perspective view showing a part of the same apparatus taken out.

FIG. 4 is a diagram schematically showing an example of a conventional device.

[Explanation of symbols]

 W web 1, 2 fixed roll 3 fixed frame 7, 8 tension applying roll 9, 10 moving frame 11, 12 guide ring 13, 14 guide plate 15 cutting device 16, 17 mounting frame

Claims (2)

[Claims] 1. An excessive tension of a web, characterized in that the web is cut when a tension of a predetermined value or more acts on the web while the web is being transferred in one direction while a predetermined tension is applied to the web. Prevention method. 2. A fixed roll arranged at a predetermined position in front of and behind the strip-shaped web in the transfer direction, a fixed frame for supporting the fixed roll, and a fixed position in the transfer direction between the fixed frames. And a tensioning roll for imparting a predetermined tension to the web, and the tensioning roll restores the web when a tension of a predetermined value or more acts on the web to provide a restoring force. It is movable by a force in a direction intersecting the transfer direction, and a cutting device capable of cutting the web by utilizing the restoring force of the web is provided at a fixed position in the transfer direction between the fixed frames. A web over tension device.