EP1121317B1 - Draw roller for striplike materials, especially paper or cardboard strips, plastic or metal foils - Google Patents

Abstract

Draw rollers for striplike materials (especially paper or cardboard strips, plastic or metal foils), having a sheath (1) that can rotate around a fixed inner component, whereby said sheath is provided with air holes along the entire surface thereof, are already known per se. A vacuum chamber (8) is arranged in the winding area of the strip. Said vacuum chamber (8) can be subjected to an underpressure. According to the invention, another vacuum chamber (8) is arranged inside the sheath (1) in the running direction of said strip (2) directly in front of the vacuum chamber (8), whereby the underpressure in the second vacuum chamber is greater than the underpressure in the first vacuum chamber (8) and is independent thereof. The upstream second vacuum chamber (8) enables the separating layer of air adhering to the strip (2) to be suctioned in a targeted manner, whereby the contact surface of the strip (2)/roller remains large enough to transmit high drawing forces.

Description

Technical field

The invention relates to a pull roller for sheet-like materials, in particular for Sheets of paper or cardboard, plastic or metal foils, one around a fixed one Inner component has a rotatably drivable jacket that extends over its entire Shell surface has air passage openings. The inside of the jacket is in segmented chambers divided, of which in the wrap area of the Path arranged chamber can be acted upon with negative pressure. Because of the negative pressure the web is sucked onto the roller in order to increase the adhesive forces and thus larger ones To be able to introduce tensile forces into the train.

State of the art

Such traction rollers are preferred in plants for the production and / or finishing sheet-like materials (paper or cardboard sheets, plastic or metal foils) used in areas where force is only applied to one side of the web is possible, for example because liquid coating material on the other side of the web is applied (DE-AS 14 74 973).

At higher web speeds, the air boundary layer adhering to the web prepares Problems when the web hits the roller. An air cushion forms between the web and the roller that causes the web to float and so on the contact area is reduced. The reduction in the contact area leads to the fact that lower tensile forces can be transmitted. In extreme cases, the roller turns under the train through.

DE 34 33 332 A discloses a device for conveying web-like material known, which consists of a suction roll, the cross section in at least three Sectors is divided. Two of the sectors are each independent Vacuum generator connected. The roller is used in the production of corrugated cardboard to Transport sheets with high positional accuracy, which are then laminated become.

DE 31 00 814 A describes a so-called default roller for storing Fabric panels on a storage table. The roller is a rotating drum with over the Circumferentially distributed through openings formed and points in the sector that the Target storage location of the goods facing the tray table, through openings on, through the air to safely lift the goods from the outer circumference of the drum is pale. In order to better define the feed location of the fabric web to the storage table according to an embodiment on a further sector section of the drum, the is adjacent to the feed side of the goods, a suction device for sucking the Arranged good things.

Presentation of the invention

The invention has for its object a pull roller of the type described Way to improve so that even at high web speeds great traction are transferable.

This object is achieved with the features of patent claim 1.

The upstream second vacuum chamber enables the one attached to the web Vacuum the air boundary layer to the extent that the contact area is sufficient remains large in order to be able to transmit the required tensile forces.

A second object of the invention is to provide a pull roller, the Simply surface on different web materials, speeds and / or Web widths is customizable.

This object is achieved with the features of patent claim 5.

The subclaims contain preferred, since particularly advantageous, configurations a pull roller according to the invention.

Brief description of the drawing

Figur 1

zeigt einen Querschnitt durch die Zugwalze,

Figur 2

zeigt einen Längsschnitt in Richtung der Drehachse,

Figur 3

zeigt als Zusammenbauzeichnung die lösbaren Teile, und

Figur 4

zeigt als Schaltschema die Elemente zur Einstellung der geforderten Druckverhältnisse in den einzelnen Kammern.

The drawing serves to explain the invention on the basis of an embodiment shown in simplified form:

Figure 1

shows a cross section through the pull roller,

Figure 2

shows a longitudinal section in the direction of the axis of rotation,

Figure 3

shows the detachable parts as an assembly drawing, and

Figure 4

shows as a circuit diagram the elements for setting the required pressure conditions in the individual chambers.

Ways of Carrying Out the Invention

The traction roller according to the invention is used in manufacturing and / or finishing plants web-shaped materials (paper or cardboard webs, plastic or metal foils) used to run the web at a high, well-defined speed and / or to pull a defined train through individual system areas. such Systems are, for example, coating, impregnation, laminating or laminating systems or plants for the production of plastic films. It can be beneficial in all Use system areas in which force is only applied to one side of the web is possible, for example behind applicators for coating material, where on the coated web side no force can be introduced. In these plant areas it preferably serves as a master drive, which specifies the path speed exactly, or as an actuator for regulating the web train.

The pull roller contains a jacket 1 which can be driven in rotation and on it entire surface area has air passage openings. The air permeability of the Sheath 1 is made through a variety of holes, by manufacturing from a porous Material etc. causes. In addition, the outer surface can be wear-resistant and / or the friction to the web 2-increasing rubber, ceramic, etc. be coated. To the air flows between the web 2 and the outer Too uniform surface and at the same time markings on the web 2 too avoid, the outer surface is preferably covered with a plastic or metal sieve. The jacket 1 is as thin-walled as possible from steel, aluminum or from one fiber-reinforced plastic material (GFK or CFK composite) manufactured to be Reduce weight and its inertia.

The inside of the jacket 1 is radial, extending over the length of the roller Partitions 3, 4, 5, 6 divided into chambers 7, 8, 9, in each of which separate Pressure ratios can be set. The partitions 3, 4, 5, 6 are part of one internal component that is stationary during operation and have friction-free, up to the inner surface of the jacket 1 seals 10. Prefers the inner component consists of an outer, extending coaxially to the roller axis Pipe 11 on which the partitions 3, 4, 5, 6 extend radially outwards are attached and in a corresponding number of distribution chambers 12, 13, 14 is divided into openings 15, 16, 17 with the vacuum chambers 7, 8, 9 in Connect. The distribution chambers 12, 13, 14 are at one axial end of the Tube 11 each connected to a vacuum or pressure line 18, 19, 20 the pressure conditions in the individual chambers 7, 8, 9 explained in more detail below adjust. In addition, the entire inner component can be rotated about the roller axis stored to the position of the segment-shaped chambers 7, 8, 9 relative to the looping area the web 2 can adjust. The rotation of the Internal component motor with a servomotor, which is from a control or regulating device is controlled. The control or regulating device positions the inner component according to predetermined algorithms, the specific physical properties of the web, for example, their porosity, and certain operational variables, such as the Path speed, included as a parameter.

In the present embodiment, the distribution chamber 14 is coaxial in the outer tube 11 arranged inner tube 21 formed, which has a nozzle with the Chamber 9 is connected. It is connected to the pressure line 20, while the with the vacuum chambers 7, 8 communicating distribution chambers 12, 13 to the Vacuum lines 18, 19 are connected. The distribution chambers 12, 13 are between the outer tube 11 and the inner tube 21 by appropriate Partitions 22 formed.

It is essential for the pull roller according to the invention that two with negative pressure inside Actuable vacuum chambers 7, 8 are present, the negative pressure of which is independent is adjustable from each other. The two vacuum chambers 7, 8 are in the circumferential direction the roller arranged immediately in succession, the in the direction of the Lane 2 (= direction of rotation of the pull roller) front vacuum chamber 7 a larger one Vacuum is adjustable than in the subsequent vacuum chamber 8, however vacuum can also be applied. The first vacuum chamber 7 includes one Angular range of at least 10 °, preferably 20 ° to 90 °, the second vacuum chamber 8 comprises an angular range of at least 20 °. Preferably the second comprises Vacuum chamber 8 has a larger angular range than the first vacuum chamber 7. The total suction angle of both vacuum chambers 7, 8 is at least as large as that Wrap angle of web 2, which is 30 ° to 240 °.

In the preferred embodiment, the second one follows inside the jacket 1 Vacuum chamber 8 is a pressure chamber 9 in which an overpressure is generated. The in Area of the pressure chamber 9 due to the excess pressure through the openings in the jacket 1 escaping air supports the detachment of web 2 from the roller. The partition 5 between the vacuum chamber 8 and the pressure chamber 9 is therefore along the Surface line arranged where the detachment of the web 2 from the roller is desired. The inside of the jacket 1 is in the segment 23 between the pressure chamber 9 and first vacuum chamber 7 neither to a compressed air supply nor to a vacuum line connected, since this area is neither wrapped by web 2 nor there is acted on the web 2. The segment 23 has on both end faces Through holes 35 through which a pressure equalization to atmospheric pressure Leakage on partition walls is caused.

Before the pull roller is operated, the inner component with the partitions 3, 4, 5, 6 is so set that the first vacuum chamber 7 is in the area in which the Web 2 runs onto the roller. The setting is preferably such that the Partition 4 between the two vacuum chambers 7, 8 in the area of the desired Ramp line is located. The second vacuum chamber 8 is designed and set so that it covers the wrapping area of the web 2. The pressure chamber then follows 9 in the run-off area of the web 2. During operation, the second vacuum chamber 8 a vacuum between 1 KPa and 10 KPa is set in the wrapped area, the which depends on the sensitivity of the material and the web speed. A larger negative pressure is set in the upstream chamber 7. The pressure difference between the two chambers 7, 8 is at least 0.5 KPa, preferably 1 KPa to 10 KPa. The greater negative pressure in the first vacuum chamber 7 causes that when web 2 runs onto the roller, the air boundary layer attached to web 2 is reduced. So there is a floating of the web 2 on the attached Air cushion and thus a shift in the contact line web 2 / roller with the Consequence prevents the contact area from being reduced. The same with large ones Web speeds sufficiently large contact area in the area of the vacuum chamber 8 makes it possible to transmit the required tensile forces. The independent Adjustability of the negative pressure in the vacuum chamber 7 allows this in Depending on the web speed to track, so constant traction conditions adjust. The desired negative pressure in the first is preferred Vacuum chamber 7 as a function of the web speed and / or the Web train set automatically by a regulating or control device, for example by actuating a control valve in the supply line 18 to the vacuum chamber 7. It is also advantageously possible to change the position by rotating the inner component the vacuum chamber 7 relative to the ascending web 2 depending on the Set the web speed so that a maximum effective suction angle is set.

In Figure 2 is a longitudinal section transverse to the web running direction through a special advantageous constructive embodiment of a pull roller according to the invention shown. This construction makes it very easy to replace the jacket, around the draw roller different webs of materials and / or different Adjust web widths. It can so coats 1 with adapted surfaces (Rubber, ceramics, friction coatings etc.), special designs and Arrangements of the passage openings and / or special air distribution mechanisms (Air guide grooves, plastic or metal sieves etc.) and / or with different Widths of the suction surfaces can be used to adapt to the web width.

The inner tube 21 and the outer tube 11 extend axially on the connection side Direction beyond the area of the jacket 1 and are not at their in Figure 2 shown end rotatably mounted in the frame of the system. The inner tube 21 is there to the compressed air line 20 and the divided outer tube 11 to the two Vacuum lines 18, 19 connected. On the opposite drive side the inner tube 21 has a pin 24 closing the pressure chamber 14, via a radial bearing 25 is drawn, which is in a recess of a bearing part 26 is fitted. The bearing part 26 is in the frame 27 of the system via a radial bearing 28 rotatably mounted and via a torsionally rigid coupling with a not shown Rotary drive connected. At its end of the bearing part 26 facing the jacket 1 an annular side wall 29 is screwed radially on the outside, the outside diameter of which corresponds to the outer diameter of the jacket 1. On the side wall 29 the jacket 1 with its front end releasably screwed.

Inside the roll, the pressure-tight area is also at both axial ends of annular sealing walls 30, 31 limited, which are fixedly connected to the inner component are and extend to the inner surface of the jacket 1. The sealing wall 30 on the Drive side is attached to the outside of the inner tube 21, the sealing wall 31 the connection side on the outside of the outer tube 11. On the sealing walls 30, 31, the partitions 3, 4, 5, 6 are also fastened with their axial ends. At the Connection side contains the storage of the shell 1, a radial bearing 32, the inner Race sits firmly on the outer tube 11. The outer race is fixed with one annular bearing part 33 connected via the second annular side wall 34th is pulled and screwed to this detachably. On the annular side wall 34 the connection-side end of the jacket 1 is attached. The side wall 34 has also through holes 37 on the pressure equalization from the outside in the Area between it and the sealing wall 31 and thus through the holes 35 also in Segment 23 and in the area between the sealing wall 30 and the side wall 29 enable.

The setting described above of the tubes 11, 21, the sealing walls 30, 31 and the partition walls 3, 4, 5, 6 not shown in Figure 2 Internal component takes place in such a way that it moves around the radial bearings 25, 32 into the required position Position is rotated. In operation, the casing 1 rotates around the two radial bearings 28, 32. A change of the jacket 1 can be carried out very easily, as in the Assembly drawing shown in Figure 3:

On the drive side, the jacket 1 is from the side wall 29 and on the connection side the side wall 34 is unscrewed from the bearing part 33. Then the Jacket 1 with the fixed side wall 34 pulled off in the axial direction and can be exchanged for a differently designed jacket 1. The design of the Jacket 1 with the annular side wall 34 as an exchange part has the other Advantage that before installation in the side wall 34 for balancing holes can be introduced.

In Figure 4, the preferred device is shown as a circuit diagram with which in the Vacuum chambers 7, 8 and the pressure chamber 14 the required pressure conditions can be set. This device only requires a controllable blower 38. Alternatively, it is possible to pass each vacuum or pressure chamber 7, 8, 9 via the lines 18, 19, 20 to be connected to its own suction or pressure blower.

In the embodiment according to FIG. 4 with only one blower 38, each contains Vacuum line 18, 19, which leads to a vacuum chamber 7, 8, a controllable valve 39, 40, with which the required negative pressure in each vacuum chamber 7, 8th can regulate. In front of the two valves 39, 40 are the two vacuum lines 18, 19 merged into a line which on the suction side of the blower 38 connected. The line 41 connected to the pressure side of the blower 38 contains a further pressure control valve 42 before it ins via a silencer 43 Free leads. Before the pressure control valve 42 is on the pressure line 41 to the pressure chamber 9 leading pressure line 20 connected, which also has a pressure control valve 44 contains in order to be able to regulate the overpressure in the pressure chamber 9. The circuit according to FIG. 4, individual and controllable in each chamber 7, 8, 14 Adjust pressure ratios. The pressure ratios are preferably set automated in the individual chambers by means of the regulating or control device, from which the valves 39, 40, 42, 44 depending on the web speed and / or the train can be controlled.

Claims (12)

1. Pull roll for web-like materials, especially for paper or board webs, plastic films or metal foils, having a cover (1) which can be driven in rotation around a stationary inner component and which, on its entire circumferential surface, has air passage openings, and having a vacuum chamber (8) which is arranged in the area in which the web (2) wraps around and to which vacuum can be applied, characterized in that in the interior of the cover (1), immediately upstream of the vacuum chamber (8) in the running direction of the web (2), there is arranged a further vacuum chamber (7) in which, irrespective of the vacuum in the vacuum chamber (8), a greater vacuum than in the latter can be set, and in that in the interior of the cover (1), in the running direction of the web (2), the second vacuum chamber (8) is followed by a pressure chamber (9), in which a positive pressure is produced.
2. Pull roll according to Claim 1, characterized in that a vacuum can be set in the first pressure chamber (7) which is at least 0.5 kPa, preferably 1 kPa to 10 kPa, greater than in the second vacuum chamber (8).
3. Pull roll according to Claim 1 or 2, characterized in that the first vacuum chamber (7) covers an angular range of at least 10°, preferably 20° to 90°, and the second vacuum chamber (8) covers an angular range of at least 30°, the second vacuum chamber (8) covering a greater angular range than the first vacuum chamber (7).
4. Pull roll according to one of Claims 1 to 3, characterized in that the cover (1) is detachably fixed at both axial ends to annular, rotatably mounted bearing parts (29, 33) and, when the fixing is released, can be pulled off the inner component in the axial direction.
5. Pull roll according to Claim 4, characterized in that the inner component contains a tube (11) that extends coaxially with respect to the roll axis,

   on which the dividing walls (3, 4, 5, 6) are fixed,

   which is connected to the chamber (8) via openings (16),

   which is connected at one axial end to a vacuum line (19), and

   to which, at one roll end, an annular bearing part (33) is rotatably fixed, to which one end of the roll cover (1) can be detachably fixed.
6. Pull roll according to Claim 5, characterized in that at the other end of the roll, the tube (11) is rotatably mounted in a bearing part (26), which is rotatably mounted in a frame (27) by means of a rotary drive and to which an annular side wall (29) is fixed as a bearing part, to which the end of the cover (1) can be detachably fixed.
7. Pull roll according to one of Claims 4 to 6, characterized in that at one axial end, the cover (1) is firmly connected to an annular side wall (34), which can be screwed firmly to the rotatably mounted bearing part (33).
8. Pull roll according to one of Claims 5 to 7, characterized in that in its interior, the tube (11) is subdivided into at least two distribution chambers (12, 13, 14) which extend over the axial length of the roll cover (1), each of which is connected to a vacuum or pressure chamber (7, 8,9) and, at the axial end of the tube (11), are connected to separate pressure lines (18, 19, 20).
9. Pull roll according to one of Claims 1 to 8, characterized in that in the interior of the roll there are two vacuum chambers (7, 8) to which vacuum can be applied and a pressure chamber (9) to which positive pressure can be applied, each of which is connected to pressure lines (18, 19, 20) with controllable valves (39, 40, 44), the pressure lines (18, 19) belonging to the vacuum chambers (7, 8) to which vacuum can be applied being fed together to the suction side of a blower (38), the pressure side of the blower (38) being connected to a line (41) that leads into the open air via a pressure regulating valve (42), and the pressure line (20) belonging to the pressure chamber (9) upstream of the pressure regulating valve (42) being connected to the pressure line (41) of the blower (38).
10. Pull roll according to one of Claims 1 to 9, characterized by a closed-loop or open-loop control device which sets the vacuum in the first vacuum chamber (7) as a function of the web speed and/or the web tension.
11. Pull roll according to one of Claims 1 to 10, characterized in that the stationary inner component is mounted such that it can rotate about the roll axis.
12. Pull roll according to Claim 11, characterized by an actuating motor for rotating the inner component and by an open-loop or closed-loop control device which controls the actuating motor in accordance with predefined algorithms.

Images