WO2002051732A2 - Device for the suspended transport of strip or sheet material in a processing machine - Google Patents

Abstract

The invention relates to a device for the suspended transport of strip or sheet material in a processing machine. The aim of the invention is the production of such a device with, in particular, an equally distributed pressure generation for the suspended transport of strip or sheet material along a guide surface with a significant reduction in the risk of crashing. Said aim is achieved, whereby the device comprises a closed, pneumatically supplied guide surface (13), functionally connected to at least one flow channel, coupled to a pneumatic system, a number of nozzles (23) with outlet openings and, adjacent thereto, guide surfaces set at an angle into the inner side of the flow channel. The guide surface (13) comprises a first guide zone (I) in the transport direction (12), in which the outlet openings for the nozzles (23), at the beginning of the guide surface (13), are directed against the transport direction (12) of the strip or sheet material. A second guide zone (II) is arranged after the first guide zone (I), in which the nozzles change orientation with regard to the outlet direction thereof to point towards the side edges (25) and a third guide zone (III) is arranged after the second guide zone (II) in which the nozzles (23) are arranged with the outlets thereof at right angles to the direction of transport (12), in the direction of both side edges (25).

Description

 [Name of the Invention] Device for floating guiding of sheet or sheet material in a processing machine

[Description]

The invention relates to a device for the floating guidance of web or sheet material in a processing machine according to the preamble of claim 1.

This device is particularly suitable for contactless sheet guidance and sheet conveying in a printing press.

[State of the art]

A known device of this type is described in DE-OS 19 07 083 with a blow box with a guide surface and a plurality of distributed blow openings, each of which has an inclined guide surface which is lowered into the blow box. However, there the nozzles have a tongue and the radial edges of the guide surface form an angle between 120 ° and 180 ° ^' . This creates a wide beam, not a directed beam, with a flat effect. All blowing nozzles are also arranged in the same direction. As a result, a hardly tightening effect can be achieved in only one direction, which is disadvantageous especially in the case of thin sheet materials, since they tend to flutter. DE 28 02 610 AI shows nozzles, the side surfaces of which run parallel to the oblique guide surface and are provided with a tongue. These nozzles are arranged closely next to one another on blow boxes and a guide surface is described which consists of several blow boxes and is arranged above and below the printing material to be guided. In one development, the nozzles are assigned a perforation which, as an additional blowing agent, is intended to prevent the processing material from coming into contact with the blow box (guide surface).

According to DE 44 06 847 AI, a device for the suspended guiding of web or sheet material along a conveying path in a conveying direction with a plurality of nozzles incorporated in a guide surface is known. The width of the guide surface is divided into at least three zones, a stabilization zone lying symmetrically to the axis of symmetry with nozzles blowing against the conveying direction and two tightening zones adjoining the stabilization zone and delimiting the guide surface. The nozzles form rows of nozzles extending longitudinally and transversely to the conveying direction. In the side tightening zones, the nozzles blow against the conveying direction and away from the axis of symmetry, the nozzles alternating with the blowing directions forming an angle of 100 ° to 120 ° and 160 ° to 170 °.

From EP 0 695 707 A2 a device for the contact-free guiding of sheet material is known. The device has a guide surface with air-blowing nozzles, the common flow pattern of which is formed when the sheet material is guided by a first speed component in the conveying direction of the sheet material and by a second and a third speed component in the direction of the respective side edges. In the case of nozzle types according to DE 19 07 083, DE 28 02 610, it is disadvantageous that the web or sheet material is strongly sucked in at the nozzle openings in the region of the strongest negative pressure and can touch the edges of the nozzles or the cut edges or the tongue-shaped sections. This danger exists particularly in the case of light or limp web or sheet materials. As a result, undesirable lubrication effects occur on the material and / or the guide surface and / or markings on the material itself. In the devices according to DE 44 06 847 and EP 0 695 707 there is an increased risk of smearing, especially when processing sheet material, in particular in the transfer areas.

OBJECT OF THE INVENTION

The invention has for its object to provide a device of the type mentioned, which avoids the disadvantages mentioned, which in particular allows an evenly distributed pressure build-up for floating guiding of sheet or web material along a guide surface and noticeably reduces the risk of smearing.

The task is solved by the training features of claim 1. Further developments result from the dependent claims.

The device for floating guiding starts from a guiding surface on which the web or sheet material is guided in a conveying direction without contact by means of an air cushion. The air cushion is fed by nozzles that work according to the aerodynamic paradox, after which the web or sheet material is carried simultaneously (overpressure area) and sucked in (underpressure area). The guide surface is closed per se and, according to a predetermined distribution, has a large number of incorporated nozzles, which as Air-loaded, preferably identical, nozzles are formed. When designing the device with the distribution below, a stable flutter-free levitation of the web or sheet material is established without contact with the guide surface.

A first advantage is based on the fact that - with respect to a single guide surface - the alignment of the nozzles with their blowing openings (blasmaul) is arranged at the beginning of the guide surface with a component against the conveying direction of the web or sheet material and then continuously in the conveying direction to both side edges (the Guide surface) is arranged to be continuous. This orientation of the blowing openings of the nozzles generates blowing air flows which - based on the line of symmetry of the guide surface running in the conveying direction - fanned out symmetrically in a mirror-symmetrical manner starting from an orientation essentially counter to the conveying direction, in an outward direction in the direction of both side edges of the guide surface and transversely (approximately at right angles) to the conveying direction. With such an arrangement, the inclination of the blowing openings of the nozzles increases in the conveying direction until they are directed laterally to the conveying direction.

Another advantage is that the guide surface, which extends at least over the maximum format width of the web or sheet material, has three guide zones I to III (per guide surface) in the conveying direction of the web or sheet material. A single guide surface can be made in one piece or modularly from several parts. Such a guide surface is functionally connected to at least one flow channel coupled to at least one pneumatic system. Blown air is blown from one or more flow channels to each of the blow openings Nozzle fed and distributed through the blow holes to form the air cushion.

It is also advantageous that within the guide zones I to III the nozzles are preferably arranged with a different nozzle density (number of nozzles per unit area) on a single guide surface. The guide zone I upstream in the conveying direction of the web or sheet material and the downstream guide zone III preferably have a greater nozzle density (number of nozzles per unit area) than the guide zone II arranged between the two guide zones I and III.

The greater nozzle density is preferably always arranged in the end areas (start area: guide zone I or end area: guide zone III) of a guide surface. In particular when processing sheet material, the respective guide zones I and III are assigned adjacent transfer areas, for example of two sheet holding systems, since a greater air density can be achieved by a greater nozzle density and the risk of smearing is thus noticeably reduced.

In an advantageous development, the guide surface in the guide zone I has the greater nozzle density compared to the guide surface III. Thus, for example, disturbances in the guidance of the web or sheet material that result from upstream devices, for example from a transfer area, can be avoided.

It is also advantageous that the nozzles oriented in this way with their blowing openings always blow in between (areas free of nozzles) areas (the closed guide surface) of two upstream nozzles with blowing air flows emerging from the blowing openings. The air flow is preferred a downstream nozzle directed in the center of the free space of two neighboring upstream nozzles. This means that all areas of the guide surface can be supplied evenly with blown air flows and a uniform pressure build-up is formed for the floating guidance of the web or sheet material over the entire guide surface.

[Examples]

The invention will be explained in more detail using an exemplary embodiment. The following schematically show:

Fig. 1 a sheet rotary printing machine in

Series construction with devices for floating sheet material,

2 shows a device for guiding sheet material in association with a sheet guiding cylinder,

3 to 8 developments of a guide surface with different nozzle arrangements,

9 and 10 special nozzle designs.

A sheet-fed rotary printing machine according to FIG. 1 consists, for example, of a plurality of printing units 1 and a coating unit 8, which are arranged in series in the direction of conveyance 12 of the sheet material. The coating unit 8 is followed in the conveying direction 12 by a cantilever 9 with a circulating conveyor system 14 which transports the sheet material in the gripper closure onto a cantilever stack and deposits it there. Each printing unit 1 consists of a plate cylinder 2, a blanket cylinder 3 and a sheet guiding cylinder 4. Each plate cylinder 2 is assigned an inking unit and, if necessary, a dampening unit. The coating unit 8 has a metering system 7 which is functionally connected to a forme cylinder 6. A sheet guiding cylinder 4 is in turn assigned to the forme cylinder 6. Between the printing units 1 and the last printing unit 1 and the coating unit 8, sheet guiding cylinders 5 are arranged, which are designed here as transfer drums and / or reversing drums. The sheet guiding cylinders 4, 5 and the conveyor systems 14 have sheet holding systems, preferably gripper systems, arranged on the start side for the sheet transport.

The sheet guiding cylinders 5, which are designed as transfer cylinders or reversing drums, and the conveyor systems 14 are assigned a plurality of fixed sheet guiding devices 11, forming a continuous guide surface 13, for contactlessly guiding sheet material at a defined distance from the sheet guiding cylinder 5 or the conveyor systems 14.

It is a single guide face 13 in the conveying direction 12 by a first transfer zone 10 and a second transfer area 10, such as sheet holding systems, the sheet guiding cylinder ^'4, 5, limited in association with a sheet guiding cylinder. 5 Alternatively, a single guide surface 13 in the conveying direction 12 is delimited by a first transfer area 10, for example a sheet holding system of the sheet guiding cylinder 4 and a sheet holding system of the conveying system 14, and a sheet braking device arranged in the delivery 9.

2 is a device for floating guidance of For example, sheet material is shown, which is to be explained in more detail on a sheet guiding cylinder 5, especially a transfer cylinder, each with a preceding and downstream sheet guiding cylinder 4, especially a printing cylinder.

Between the sheet guide cylinder 5 and the upstream sheet guide cylinder 4 and between the sheet guide cylinder 5 and the downstream sheet guide cylinder 4, the transfer area 10 of two sheet holding systems is arranged in the respective tangent point. In such a transfer area 10, the sheet material is transferred from a sheet holding system to a second sheet holding system. In the conveying direction 12 of the sheet material, the first transfer area 10 is followed by a sheet outlet 17 and in the conveying direction 12, the sheet exit 17 is followed by a sheet riser 18 with the subsequent second transfer area 10.

In the present example, two sheet guiding devices 11, based on an axis of symmetry 22, are arranged below the sheet-guiding cylinder 5 in a modular manner (mirror-to-butt assembly) and together form the uniform guide surface 13.

Each sheet guiding device 11 is box-shaped as a pneumatically actuatable first flow channel and has a part of the guide surface 13 with nozzles 23 for the discharge of blown air according to the blown suction or venturi principle (aerodynamic paradox). For this purpose, each sheet guide device 11 is assigned a first pneumatic system 15, preferably at least one fan, which is functionally connected to the first flow channel of the sheet guide device 11 and which provides the air supply to the sheet guide device 11. Each sheet guide 11 is below the sheet guide cylinder at a defined distance from it Arranged circumferentially to ensure contact-free floating sheet guidance.

In a preferred embodiment, the sheet guiding device 11 adjacent to the sheet outlet 17 has an upstream, first comb plate 16 pointing in the direction of the transfer area 10. The comb plate 16 mechanically or pneumatically supports the sheet guidance in the sheet outlet 17.

In a preferred development, a second flow channel 20 is arranged below the sheet guiding device 11 (first flow channel) and is functionally connected to the second pneumatic system 19. The second pneumatic system 19 is arranged on the rear side of the second flow channel 20 and supplies the flow channel 20 with air via an opening, so that a flow of lower blowing pressure and high volume flow emerges at an outflow opening 21. In this case, the second flow channel 20 has at least one, preferably a plurality of outflow openings 21 for the blown air which extend over the maximum format width and which are directed in the direction of the transfer region 10 against the underside of the sheet into the sheet outlet 17.

Analogous to the arch exit 17, the arch emergence 18 is also mirror-image to the symmetry axis 22 below the downstream transfer area 10, a second, separately controllable pneumatic system 19 is also fixed to the frame, which is preferably formed by several fans and, analogous to the arch exit 17, a blowing air flow with low blowing pressure and high volume flow against the Bottom of the sheet in the direction of transfer area 10 generated. A second flow channel 20, which is functionally connected to the second pneumatic system 19, is arranged in the arch rise 18, analogously to the arch exit 17, below the arch guide 11. The second Pneumatic system 19 is arranged on the back of the second flow channel 20 and supplies the flow channel 20 with air via an opening, so that at an outflow opening 21 a flow of low blowing pressure and high volume flow, which is directed essentially towards the transfer area 10 and thus towards the underside of the sheet is leaving. In this case, the second flow channel 20 has at least one, preferably a plurality of outflow openings 21 for the blown air which extend over the maximum format width and which are directed in the direction of the transfer region 10 against the underside of the sheet and into the sheet emergence 18.

3 to 8 show developments of a guide surface 13 which is closed per se and the nozzles 23 are arranged distributed over the width and the length of the guide surface 13 (in the conveying direction 12).

In the conveying direction 12 (along the guiding surface 13), each guiding surface 13 has a first guiding zone I, in which the blowing openings 24 (blasmaul) of the nozzles 23 lying below the plane of the guiding surface 13 at the beginning of the guiding surface 13 have a component against the conveying direction 12 of the Sheet material are directed. The guide zone I is preferably formed by at least two rows of nozzles 23. An arrangement of the blowing openings 24 directed against the conveying direction 12 or obliquely to the conveying direction 12 is advantageous in particular in the first row in order to avoid lubrication.

It follows the first guide zone I in the conveying direction 12, a second guide zone II, in which the blowing openings 24 of the nozzles 23 are arranged from blowing openings 24 which are directed essentially against the conveying direction 12 into blowing openings 24 directed on both sides towards the side edges 25. With With respect to the line of symmetry 26, the blowing openings 24 are preferably arranged in mirror image. In the guide zone II, the nozzles 23 are preferably arranged on curved, spaced-apart tracks 27, at least one intersection of which lies on the line of symmetry 26. The intersection is preferably directed against the conveying direction 12.

Finally, the second guide zone II in the conveying direction 12 is followed by a third guide zone III in which the blowing openings 24 of the nozzles 23 are directed essentially at right angles (transversely) to the conveying direction 12 in the direction of both side edges 25 of the guide surface 13. This guide zone III is formed by at least two rows of nozzles 23.

When the nozzles 23 are arranged on the guide surface 13, in particular in the region of the guide zones II and III, the inclination of the nozzles 23 for each row of nozzles increases by a defined amount, starting from an arrangement approximately against the conveying direction 12 to an arrangement transverse to the conveying direction 12 to.

If nozzles 23 are arranged on the line of symmetry 26, these are predominantly arranged with the blowing openings 24 against the conveying direction 12.

In a preferred embodiment, the guide surface 13 has a greater nozzle density in the conveying direction 12 in the first and third guide zones I, III and a lower nozzle density in the second guide zone II arranged therebetween. The nozzle density in the conveying direction 12 and transversely to the conveying direction 12 can be made variable. In particular in the case of a transfer area 10 upstream of the guide surface 13, the guide surface 13 has the greatest nozzle density in the first guide zone I. This is a Reinforced air cushion can be achieved in the guide zone I, which supports the sheet material in the smear-free entry into the sheet outlet 17.

The arrangement of the nozzles 23 continues continuously from the guide zone I to the guide zone III. With respect to a line of symmetry 26 running in the conveying direction 12, all nozzles 23 with blowing openings 24 on the guide surface 13 are preferably arranged in mirror image from the guide zone I to the guide zone III.

The length of the guide zone II in the conveying direction 12 of the sheet material is preferably greatest within a guide surface 13.

The nozzles 23 are preferably arranged in the guide zones I-III of a guide surface 13 such that the blowing flow of a downstream nozzle 23 is always directed into the free space (part of the closed guide surface 13) of two upstream neighboring nozzles 23. The blowing flow of the downstream nozzle 23 is preferably directed centrally into the free space of the two upstream nozzles 23.

At least in the guide zone II, the nozzles 23 arranged in mirror image to the line of symmetry 26 extend on curved paths 27 spaced apart from one another. At least one intersection of the lines 27 arranged in mirror image lies on the line of symmetry 26. The intersection of two paths 27 against the conveying direction 12 is preferred directed.

The design of the device for the floating guiding of web or sheet material is not limited to at least one sheet guiding device 11 with a guide surface 13. Rather, there are also several pneumatically actuated A plurality of flow channels coupled sheet guiding devices 11 in a modular design can be implemented as a guide surface 13.

Furthermore, the guide surface 13 is not limited to an assignment to at least one sheet guide cylinder 5. In addition, a guide surface 13 can also be arranged in the delivery arm of a machine that processes sheet material. Such a guide surface 13 can also be used in machines processing web material, for example in a dryer section of a web printing machine.

The nozzles 23 arranged on the guide surface 13 are preferably configurations according to FIGS. 9 and 10.

FIG. 9 shows a nozzle 23 which, in the rear area, has a planar depression 28, which is recessed in relation to the guide surface 13 and ends at an edge 29 and merges into the guide surface 13. Arranged below the edge 29 are a first blowing opening 24.1 and a second blowing opening 24.2, which are effective as separate blowing openings 24 through a vertical separation point 30. The blowing openings 24.1, 24.2 are adjoined by a guide surface 31 which slopes into the guide surface 13 and which are formed by flanks 32, 33 as laterally closed side surfaces which transition into the guide surface 13.

FIG. 10 shows a nozzle 23 which, in the rear area, has a planar depression 28, which is recessed in relation to the guide surface 13 and ends at an edge 29 and merges into the guide surface 13. The depression 28 furthermore has at least one second edge 34 facing away from the first edge 29 and delimiting the depression 28. In the present example, the depression 28 has a third edge 35. Below the first edge 29 there is a blow opening 24 for the front area (greatest blowing force) and below the second and third edges 34, 35 there is a blowing opening 36 (for the edge 34) and a blowing opening (not visible) for the edge 35. The blowing openings 24, 36 and the non-visible blowing opening on the edge 35 are adjoined at an angle by guiding surfaces 31, which are delimited by flanks 32, 33 as laterally closed side surfaces.

[REFERENCE LIST]

1 printing unit

2 plate cylinders

3 blanket cylinders

4 sheet guide cylinders

5 sheet guide cylinders

6 forme cylinders

7 dosing system

8 coating unit

9 outriggers

10 transfer area

11 sheet guiding device (first flow channel)

12 Direction of conveyance

13 guide surface

14 Conveyor system

15 first pneumatic system

16 comb plate

17 arch exit

18 arch rise

19 second pneumatic system 20 second flow channel

21 outflow opening

22 axis of symmetry

23 nozzles

24 blow opening

25 page margin

26 line of symmetry 27 orbit

28 lowering 29 edge

30 separation point 31 guide surface 32 edge

33 edge

34 edge

35 edge

36 blowing opening

I first management zone

II second management zone

III third management zone

Claims

[Claims] Device for the floating guiding of web or sheet material in a processing machine, in particular a printing machine in the conveying direction along a closed guide surface, the guide surface being functionally connected to at least one flow channel coupled to a pneumatic system and the guide surface a plurality of nozzles with at least blow openings and has adjacent guide surfaces which are lowered obliquely into the inside of the flow channel, characterized in that the nozzles (23) extend over the width of the guide surface (13) and distributed lengthways in the conveying direction (12), that the guide surface (13) in the conveying direction (12) has a first guide zone (I) in which the blowing openings (24) of the nozzles (23) at the beginning of the guide surface (13) are directed against the conveying direction (12) of the web or sheet material with a component such that a second guide zone (II) is arranged downstream of the first guiding zone (I) in the conveying direction (12) , in which the nozzles (23) with blowing openings (24) - starting from an arrangement essentially directed against the conveying direction (12) - merge into an arrangement directed towards the side edges (25) and that the second guide zone (II) in the conveying direction ( 12) is followed by a third guide zone (III), in which the nozzles (23) with blowing openings (24) are arranged essentially at right angles to the conveying direction (12) in the direction of the side edges (25) of the guide surface (13). 2. Device according to claim 1, characterized in that the nozzles (23) on the guide surface (13) for each row of nozzles, starting from an arrangement approximately counter to the conveying direction (12) to an arrangement transverse to the conveying direction (12) have a defined amount of increasing inclination. 3. Device according to at least claim 1, characterized in that the nozzles (23) in the guide zones (I - III) are arranged such that the blowing flow of a downstream nozzle (23) into the free space of two upstream, adjacent nozzles (23) is directed. 4. The device according to at least claim 1, characterized in that in the conveying direction (12) the guide surface (13) in the first and the third guide zone (I, III) each has a greater nozzle density and in the second guide zone (II) arranged in between. has a lower nozzle density. 5. The device according to at least claim 1, characterized in that the guide surface (13) in the first guide zone (I) has the greatest nozzle density. 6. The device according to at least claim 1, characterized in that the arrangement of the nozzles (23) from the guide zone (I) to the guide zone (III) merges continuously. Device according to at least claim 1, characterized in that - with respect to a line of symmetry (26) running in the conveying direction (12) - the nozzles (23) with blowing openings (24) on the guide surface (13) are mirror images of the guide zone (I) to Guide zone (III) are arranged. 8. The device according to at least claim 1, characterized in that the guide zone (II) is largest within the guide surface (13) in the conveying direction (12). 9. The device according to at least claim 1, characterized in that at least in the guide zone (II) the nozzles (23) are preferably arranged on curved tracks (27), at least one respective intersection of the tracks (27) on the line of symmetry (26). lies. 10. The device according to at least claims 1 and 9, characterized in that the intersections of the tracks (27) are directed against the conveying direction (12).

Fig. 3 [Attached drawings] Number of attached drawings: 10