JP2005231769A - Pressurizing device and pressurizing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressurizing device and a pressurizing method which do not generate wrinkle in a web, prevent meandering of the web, keep a good state for a long time, and are easily managed. <P>SOLUTION: In the pressurizing device and the pressurizing method applied to the device, a pressurizing roller and a tension roller are arranged inside a flexible belt of closed loop, the pressurizing roller is a roller with a crown for uniformly pressurizing the flexible belt in the width direction in pressurization, the tension roller is a roller for applying tension to the flexible belt, the pressurization is performed by the pressurizing roller via the flexible belt. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention can be applied to a pressure drum section of a rotary printing press, a nip roller provided in an industrial machine such as a papermaking machine, a pressure / heating roller in an electrophotographic image forming apparatus (copying machine, printer, facsimile), and the like. It belongs to the technical field of pressurizing method and pressurizing apparatus.

  In a nip roller or the like that sandwiches and transfers a web, it is necessary to make the nip pressure uniform in the web width direction (perpendicular to the transfer direction). The necessity is particularly high when the web is an extremely thin plastic film. If the nip pressure is not uniform, it will cause wrinkles and meandering. In the case of the impression cylinder of the printing press, if the printing pressure is not uniform, the transfer of ink is not uniform and unevenness of the printing density occurs, particularly adversely affecting the reproducibility of highlights.

As means for uniformly applying pressure, for example, there are a rubber roller with a crown, a mantel pressure drum, a nip roller with a backup roll, a nip roller having a large center weight, and the like. Each will be described.
(1) Rubber roller with crown (see Fig. 3)
The crown is a diameter increased toward the center of the roller for the purpose of correcting the deflection of the roller under pressure, or a diameter difference between the central portion and the end portion. By attaching the crown to the rollers, the linear pressure on the contact surface between the rollers can be made uniform over the entire length. In FIG. 3, the rubber of the rubber portion compensates for the increased thickness of rubber even if the pressure cylinder is bent by the applied pressure and the center is lifted, so that the nip pressure can be made uniform.
The following a and b are mentioned as problems of this crown-equipped rubber roller. a. The circumferential speed is different between the center and the end of the roll, and wrinkles and meandering are generated in the nipped web. b. As rubber gradually deteriorates and wears as it is used, the crown shape changes and it is difficult to maintain and manage a good state.

(2) Mantel impression cylinder (see Fig. 4)
As shown in FIG. 4, the Mantel impression cylinder has a structure in which the roller surface has a cylindrical shape without a crown, but the position where the pressure is applied is inside the roller. Since the bending moment acting on the roller is smaller than that of a normal roller on which pressure is applied at both end positions, the deflection of the roller is small, and uneven nip pressure is improved.
The following c and d are listed as problems of the Mantel impression cylinder. c. Although the point of application of the applied pressure is moved inside the roller, the nip pressure is difficult to be uniform because the deflection is smaller than that of a normal roller but the deflection cannot be eliminated. d. Due to its structure, it is easy to bend because its bending rigidity is lower than that of a normal roller closed by a side wall. Further, the thickness of the roller is increased to increase the rigidity, and the weight is increased.

(3) Roller with backup roller (see Fig. 5)
This is a roller that pressurizes from above the nip roller (back side) with a metal roller or the like, and makes the nip pressure uniform by correcting the deflection caused by bending deformation of the nip roller.
The following e and f can be cited as problems of the roller with backup roller. e. Since the backup roller itself receives pressure at both ends, the deflection occurs, the center part floats, and the rubber roll center part cannot be pushed completely, so the effect is small. f. Since the pressure deformation part of the rubber roller is doubled, the fatigue deterioration of the rubber is severe.

(4) Nip roller with increased center weight (see Fig. 6)
A roller with a built-in weight in the center of a cylindrical metal core that makes the nip pressure uniform by correcting the lifting of the center of the roller due to deflection caused by the applied pressure with the weight of the weight (Patent Document) 1).
JP, 10-45292, A The following g and h are mentioned as a problem of this roller with a backup roller. g. There is a limit to the weight of the weight that can be provided in the center due to the restriction of the roller size. h. The rollers are quite heavy and dangerous in terms of safety and hygiene during replacement work.

  An object of the present invention is to provide a pressurizing method and a pressurizing apparatus that do not cause wrinkles on the web, do not meander the web, and maintain a good state for a long time and are easy to manage.

According to a first aspect of the present invention, there is provided a pressure device comprising a closed loop flexible belt and a pressure roller disposed on the inside thereof, and the pressure roller causes the flexible belt to move in the width direction during pressure application. A roller with a crown for applying uniform pressure, wherein the pressure is applied by the pressure roller via the flexible belt.
According to a second aspect of the present invention, there is provided a pressure device according to the first aspect, further comprising a tension roller that applies a tension to the flexible belt as a pair with the pressure roller. .
According to claim 3 of the present invention, in the pressure device according to claim 1 or 2, the pressure roller is made of a metal material.
A pressure device according to a fourth aspect of the present invention is the pressure device according to any one of the first to third aspects, further comprising an opposing roller that faces the pressure roller with the flexible belt interposed therebetween. It is configured to pressurize the web existing between the flexible belt and the opposing roller.
According to a fifth aspect of the present invention, in the pressure device according to the fourth aspect, the opposing roller is a plate cylinder of a rotary printing press.
According to a sixth aspect of the present invention, a pressure roller is disposed inside a closed loop flexible belt, and the pressure roller uniformly pressurizes the flexible belt in the width direction during pressure application. A roller with a crown for applying pressure by the pressure roller via the flexible belt.

According to the pressure device according to claim 1 of the present invention, the pressure roller, which is a roller with a crown for uniformly pressing the flexible belt in the width direction at the time of pressure application, is disposed inside the closed-loop flexible belt. Then, pressure is applied through the flexible belt by the pressure roller. That is, the peripheral speed is the same at the center and at the end, and the wear of the flexible belt can be reduced by increasing the peripheral length of the closed loop. Therefore, there is provided a pressurizing device that does not generate wrinkles when the web is pressurized, does not meander the web, and maintains a good state for a long time and is easy to manage.
According to the pressure device according to claim 2 of the present invention, a tension is applied to the flexible belt by the tension roller as a pair with the pressure roller. Therefore, an appropriate tension can be applied to the flexible belt, and the pressure can be stabilized.
According to the pressure device according to claim 3 of the present invention, a pressure roller made of a metal material is applied. Therefore, since the crown is attached to the metal core that is hard to wear, a good state is maintained for a long time and is easy to manage.
Moreover, according to the pressurizing apparatus which concerns on Claim 4 of this invention, the web which exists between an opposing roller and a flexible belt is pressurized.
According to the pressurizing device according to claim 5 of the present invention, the web existing between the plate cylinder and the flexible belt is pressed.
According to the pressurizing method according to claim 6 of the present invention, the pressure roller, which is a roller with a crown for uniformly pressing the flexible belt in the width direction at the time of pressurization, is located inside the closed loop flexible belt. And pressure is applied by the pressure roller via the flexible belt. That is, the peripheral speed is the same at the center and at the end, and the wear of the flexible belt can be reduced by increasing the peripheral length of the closed loop. Therefore, there is provided a pressing method that does not cause wrinkles on the web when the web is pressurized, does not meander the web, and maintains a good state for a long time and is easy to manage.

  The pressurizing apparatus and pressurizing method of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing the configuration of the pressure device of the present invention. FIG. 2 is an exaggerated view of the shape of the crown additional pressure roller in the pressure device of the present invention. 1 and 2, 1 is a pressure roller, 2 is a rubber belt, 3 is a tension roller, 4 is a counter roller, 11 is a metal core, 12a and 12b are shafts, and 100 is a web.

The pressure roller 1 is a roller that applies pressure via a rubber belt 2. In the example shown in FIG. 1, the web 100 is sandwiched between the rubber belt 2 and the opposing roller 4, and the web 100 is pressed against the opposing roller 4 when the pressure roller 1 applies pressure. Normally, the opposing roller 4 is a fixed roller that is rotatably supported by a frame (not shown) but does not move except for rotation. On the other hand, the pressure roller 1 is supported by a moving mechanism (not shown) so as to be able to move between a pressure position for applying pressure and a retracted position where pressure is not applied. When the pressure roller 1 moves between the pressure position and the retracted position, the rubber belt 2 and the tension roller 3 also move together.
Note that the present invention is not limited to the above, and at least one of the pressure roller 1 and the counter roller 4 can be configured to have two states of pressure and non-pressurization as long as it moves relative to the frame.

  As the moving mechanism of the pressure roller 1, a known moving mechanism can be applied. For example, a subframe (not shown) that rotatably supports the pressure roller 1 and the tension roller 3 is supported at the tip of an arm that moves while drawing an arc, and the rotation shaft at the base end of the arm rotates in the frame. It is supported freely. As an arm moving mechanism, for example, an air cylinder having one end coupled to the arm and the other end coupled to the frame is used. The pressure mechanism of the pressure roller 1 can also serve as an air cylinder used for the moving mechanism. In addition, an air cylinder dedicated to pressurization may be provided separately from the air cylinder used for the moving mechanism.

  The material of the pressure roller 1 requires rigidity and wear resistance. Therefore, it is preferable to use a metal material such as a steel material or an aluminum alloy. Further, like a normal guide roller, the pressure roller 1 has a hollow structure that can be reduced in weight while maintaining rigidity. The roller surface is crowned so that the contact surface with the rubber belt 2 is parallel when a predetermined pressure is applied. Details of the crown will be described later. Further, the roller surface length of the pressure roller 1 may be larger, smaller, or the same as the width of the rubber belt 2. When the roller surface length is large, even if the rubber belt 2 meanders, it is difficult to come off from the pressure roller 1. When the roller surface length is small, even if the rubber belt 2 meanders, the pressure range (surface length) of the pressure roller 1 does not change or becomes small. When the roller surface length is the same, if the rubber belt 2 does not meander or is small, the use efficiency of the roller surface length is maximized.

  The rubber belt 2 is an example of a flexible belt, and is a flexible belt mainly made of rubber. As shown in FIG. 1, the rubber belt 2 is a closed-loop belt, that is, an endless ring-shaped belt. A pressure roller 1 and a tension roller 3 are disposed inside the closed-loop rubber belt 2. By adjusting the distance between the pressure roller 1 and the tension roller 3, an appropriate tension is applied to the rubber belt 2.

  As the main material of the rubber belt 2, NBR (nitrile / butadiene rubber), EPDM (ethylene / propylene diene monomer: ethylene / propylene rubber), or the like can be used. The width of the rubber belt 2 may be larger, smaller, or the same as the roller surface length of the pressure roller 1 (for the reason described above). In many cases, the thickness of the rubber belt 2 is preferably the same as the thickness of the rubber in a conventionally used rubber roller (often about 15 mm). Further, it is preferable that the length of the rubber belt 2 is as long as possible in the limitation due to the space where the pressure device is installed. By increasing the circumference, the frequency of deformation is reduced and the influence of rubber deterioration due to fatigue is reduced.

  An example of a method for manufacturing the rubber belt 2 will be described. First, the manufacturing dimensions (peripheral length and thickness) of the belt are determined, and a metal belt having the same peripheral length is prepared. Then, the metal belt is stretched with an appropriate jig, and the rubber is bonded and wound. Furthermore, vulcanization is performed in that state, and then polishing is performed to finish the surface.

  The tension roller 3 is disposed inside the closed-loop rubber belt 2 and holds the closed-loop rubber belt 2 together with the pressure roller 1. The tension roller 3 is a roller for applying an appropriate tension to the rubber belt 2 by adjusting a distance between the pressure roller 1 and the shaft. Therefore, the tension roller 3 is provided with an adjusting mechanism that can move the position of the shaft supported by the sub-frame away from or close to the position of the shaft of the pressure roller 1. Alternatively, an air cylinder that pressurizes the tension roller 3 in a direction away from the shaft position of the pressure roller 1 may be provided instead of the adjusting mechanism.

  The opposing roller 4 is disposed so as to face the pressure roller 1 with the rubber belt 2 interposed therebetween, and to press the web existing between the rubber belt 2 by receiving the force of the pressure roller 1. Is a roller. The axis of the counter roller 4 is parallel to the axis of the pressure roller 1 and the axis of the tension roller 3 described above. The facing roller 4 is, for example, one roller of a nip roller configured by a pair of rollers together with the pressure roller 1. The counter roller is, for example, a plate cylinder of a rotary printing press.

As described above, the opposed roller 4 is usually a fixed roller whose axis is rotatably fixed to the frame. Further, the roller is driven to rotate. The pressure roller 1, the rubber belt 2, and the tension roller 3 are integrated with the counter roller 4 that is driven to rotate, and move to the pressure position and the retracted position. The roller 3 is not driven to rotate, but only rotates.
Since the web 100 can be transported by rotating either one of the counter roller 4 and the pressure roller 1, the pressure roller 1 may be rotationally driven. Or you may comprise so that both the opposing roller 4 and the pressurization roller 1 may be rotated in synchronization.

  The configuration has been described above. Next, an example of how to apply the crown in the pressure roller 1 of the pressure method and pressure device of the present invention will be described. The dimensions of the metal core of the gravure impression cylinder are shown as an example in FIG. Assuming that the load acting on the impression cylinder shown in FIG. 7 is simply distributed load (300 kg / 110 cm) and is simply supported at the impression cylinder bearing position, the maximum deflection is 0.083 mm.

The maximum deflection is δ, the axial position of the metal core is x, the surface length of the metal core is L, and the crown amount is y. The crown amount y at any position x is given by y = F (x). y = F (x) is a function in which y = 0 when x = 0 and x = L. Further, the function is such that x = L / 2 and y = δ. Therefore, if the crown amount y is complemented by a quadratic function, the function is y = − (4δ / L ² ) (x ² −Lx).
In FIG. 7, a value obtained by adding the crown amount y calculated by the above function to the reference diameter φ130 mm of the metal core is the finished dimension.

In the above, an example was demonstrated about how to attach a crown. Next, an example of the operation of the pressure device of the present invention will be described.
First, in step S1, the pressure roller 1, the rubber belt 2, and the tension roller 3 integrated with the subframe are in the retracted position. At this time, the web 100 exists in a position sandwiched between the rubber belt 2 and the opposing roller 4 by finishing the paper threading. When the method of applying tension to the rubber belt 2 is pressurization of the tension roller 3 by an air cylinder for tension, pressurized air is sent to the air cylinder to obtain an appropriate tension.

Next, in step S2, rotational driving of the opposing roller 4 is started at a slow speed. Further, the arm supporting the subframe is moved by operating the air cylinder for movement, and is changed from the retracted position to the pressurizing position. The integrated pressure roller 1, rubber belt 2, and tension roller 3 are present at the pressure position. That is, the web 100 existing between the rubber belt 2 and the counter roller 4 is pressurized, and the rotation of the counter roller 4 is transmitted to the rubber belt 2 via the web 100 by frictional force. Run. Accordingly, the pressure roller 1 and the tension roller 3 also rotate.
The applied pressure is set to a predetermined value in advance, but if necessary, fine adjustment is made here. The pressure is adjusted by adjusting the pressure of pressurized air in a moving air cylinder or by adjusting the pressure of pressurized air in a dedicated air cylinder.

  Next, in step S3, the rotation speed of the opposing roller 4 is increased to a normal operation speed (production speed, printing speed). The traveling speed of the rubber belt 2 follows the rotational speed of the facing roller 4. The rotation of the pressure roller 1 also follows, and uniform pressure is stably applied over the entire width of the roller surface.

  Next, in step S4, the rotation speed of the facing roller 4 is decreased and the operation is finished. Further, by operating the air cylinder for movement, the arm supporting the subframe is moved to change from the pressurizing position to the retracted position. If necessary, the tension of the rubber belt 2 is lowered to prevent the rubber belt 2 from being deteriorated by the tension.

It is a side view which shows the structure in the pressurization apparatus of this invention. It is the figure which exaggerated and showed the shape of the crown additional pressure roller in the pressurization apparatus of this invention. It is a figure which shows the rubber roller with a crown. It is a figure which shows the Mantel impression cylinder. It is a figure which shows a roller with a backup roller. It is a figure which shows the nip roller which enlarged the center weight. It is a figure which shows an example of the dimension in the metal core of the impression cylinder for gravure printing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure roller 2 Rubber belt 3 Tension roller 4 Opposed roller 11 Metal core 12a, 12b Shaft 100 Web

Claims (6)

  A closed loop flexible belt, and a pressure roller disposed inside thereof, the pressure roller being a roller with a crown for uniformly pressing the flexible belt in the width direction when pressurized, A pressure device configured to be pressed by the pressure roller via a flexible belt.   2. The pressure device according to claim 1, further comprising a tension roller that applies a pair of tension to the flexible belt with the pressure roller.   3. The pressure device according to claim 1, wherein the pressure roller is made of a metal material.   The pressure device according to any one of claims 1 to 3, further comprising a facing roller that faces the pressure roller with the flexible belt interposed therebetween, and exists between the flexible belt and the facing roller. A pressurizing apparatus configured to pressurize a web to be pressed.   5. The pressure device according to claim 4, wherein the opposing roller is a plate cylinder of a rotary printing press. A pressure roller is disposed inside a closed-loop flexible belt, and the pressure roller is a roller with a crown for uniformly pressing the flexible belt in the width direction during pressure application. A pressurizing method characterized by pressurizing with the pressure roller via

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