EP1688251B1 - Printing unit of a printing machine - Google Patents

Abstract

The mechanism has at least one forme cylinder (11,14), a transfer cylinder (12) and a counter print cylinder (13) of essentially the same circumference as the forme cylinder. A cover (15) essentially covers the entire width of the transfer cylinder and the forme cylinder has a pressure plate that extends in its axial direction over the entire width of the forme cylinder.

Description

The invention relates to a printing unit of a printing press according to the preamble of claim 1.

From the EP 01 82 156 A2 is an offset printing machine with at least one blanket cylinder and at least one plate cylinder known, which unwinds several times, in particular twice on one revolution of the blanket cylinder. In order to relieve the blanket from the pressure exerted by the plate cylinder contact pressure to its output voltage, a longitudinally extending recess is provided on the blanket cylinder opposite the clamping channel, which may be formed in the blanket.

From the WO 02/081213 A2 a printing unit of a printing press is known with a cylinder pair of cylinders whose circumference corresponds in each case substantially to a length of a section length of a printed page. The effective lateral surface of at least one of the cylinders, viewed in the circumferential direction, has at most one interruption or a channel, but viewed in the longitudinal direction, a plurality of juxtaposed interruptions or channels, which are arranged offset from one another in the circumferential direction. Since the elevators on the cylinders are not held in channels extending along the length of the cylinder but in circumferentially offset channels, a channel impact is greatly reduced in the passage of the channel during the unwinding of two cooperating cylinders. As a result, a particularly low-vibration, compact printing unit is created.

From the WO 01/39974 A2 a transfer cylinder of a rotary printing machine is known with at least two in the circumferential direction of the transfer cylinder successively arranged channels for receiving one or more blankets, wherein at least one of the channels of the transfer cylinder is at least partially covered by a blanket.

From the WO 01/39977 A1 a printing unit of a rotary printing machine with a transfer cylinder and a forme cylinder is known, wherein the transfer cylinder has a channel for receiving one or more blankets and the forme cylinder at least two seen in the circumferential direction successively arranged channels for receiving one or more printing plates. At least one of the channels of the forme cylinder is at least partially covered by a printing plate and the at least partially covered channel rolls off in the region of a channel of the cooperating transfer cylinder.

In printing units with comparatively slender and therefore relatively flexible pressure cylinders, disturbing streaks often occur in the printed product. The reason for this is that bending vibrations in the pressure cylinders are excited during channel overruns, which lead to fluctuations in the compressive stress in the pressure gap. Depending on the size of these pressure fluctuations, these can lead to stripes in the printed product.

• Zum einen bestehen produktionstechnisch bedingte Formatbeschränkungen des Metalldrucktuchs insofern, als das Trägerblech nur in einer maximalen Breite von etwa 1.000 bis 1.200 mm zur Verfügung steht, woraus sich derzeit letztlich ein maximales Format des Metalldrucktuchs je nach Anbieter von 1.000 x 2015 mm, 1.000 x 2.120 mm oder 1.200 x 1.600 mm ergibt.

Basically, it is known to use in printing units of printing presses on the transfer cylinders vibration-reducing metal blankets, as for example, from the above WO 02/081213 A2 in the context of printing cylinders simple scope are known. The solution proposed there is not applicable, in particular in commercial web offset technology, where increasingly double-circumference machines are used, for the following reasons:

• On the one hand there are production-related format limitations of the metal printing blanket insofar as the carrier sheet only in a maximum width of about 1,000 to 1,200 mm is available, which ultimately results in a maximum format of the metal printing blanket depending on the provider of 1,000 x 2015 mm, 1,000 x 2,120 mm or 1,200 x 1,600 mm.

On the other hand, commercial printers want to be able to drive all paper web widths in the central position up to the maximum specified width. The printing area must therefore extend to the entire bale width of the cylinder, so it can not be used on the bale adjacent blankets. A cylinder with a split and offset channel as in o. G. The prior art is therefore not feasible in the case of commercial web offset.

For these reasons, according to the prior art, the use of metal blankets is subject to the following limitations: For circumferences of cylinders smaller than 1,000 mm, a maximum width of 1,600 to 2,120 mm depending on the manufacturer is available. When the cylinders are larger than 1,000 mm, a maximum width of 1,600 mm is available. When the cylinders are larger than 1,200 mm, a maximum width of 1,200 mm is available.

It follows that many frequently requested formats can not be realized with metal blankets. On the other hand, these formats can not all be realized with conventional blankets due to the then occurring vibration problem.

The DE 198 03 809 A1 discloses a newsprint printing machine having a form cylinder having four printing plates in the axial direction and an associated transfer cylinder having a single blanket in the circumferential direction and two metal blankets in the axial direction, wherein the one circumference of the transfer cylinder is an integer multiple of the circumference of the forme cylinder.

The invention has for its object to provide a printing unit of a printing press for large printing substrate widths with reduced bending vibrations.

The object is achieved by the features of claim 1.

The achievable with the present invention consist in particular that a vibration excitation is minimized as a result of Kanalüberrollungen.

At the same time, there is no restriction on the possible production forms, since different paper web widths in central production are possible due to the blanket, which is not necessarily divided in the bale width in contrast to the prior art.

In addition, the cooperating with the transfer cylinder form cylinder and the corresponding printing form must not be changed, in particular, the forme cylinder may continue to have a continuous channel.

In a particularly preferred embodiment of the invention, it is provided that the axes of the forme cylinder, the transfer cylinder and the impression cylinder of the printing unit or, in the case of a double printing unit, the axes of the two forme cylinder and the two transfer cylinders are in a plane, which in connection with the pairwise By 180 ° offset wells a vibration reduction can be achieved by destructive interference.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Fig. 1

eine schematische Seitenansicht wesentlicher Teile eines Dreizylinder- Offsetdruckwerks gemäß der Erfindung;

Fig. 2

ein nicht beanspruchtes Detail des Gummituchs des Übertragungszylinders des Druckwerks;

Fig. 3

eine schematische Seitenansicht wesentlicher Teile eines als Doppeldruckwerk ausgebildeten Offsetdruckwerks.

Show it:

Fig. 1

a schematic side view of essential parts of a three-cylinder offset printing unit according to the invention;

Fig. 2

an unclaimed detail of the blanket of the transfer cylinder of the printing unit;

Fig. 3

a schematic side view of essential parts of a trained as a double printing offset printing unit.

First, the embodiment according to Fig. 1 and the non-claimed embodiment according to Fig. 2 Referenced. The illustrated here, for example, three-cylinder offset printing that particular job printing is formed comprises a cylinder 01, z. B. forme cylinder 01, a cooperating with this cylinder 02, z. B. transfer cylinder 02 and one cooperating with the transfer cylinder 02, with this a printing gap for a web-shaped substrate 04, z. B. printing material 04 forming cylinder 03, z. B. impression cylinder 03. The circumference of each cylinder 01; 02; 03 is equal to two or a multiple of two pages to be printed and may be greater than 1,200 mm.

Instead of the impression cylinder 03, another, not shown transfer cylinder could be provided which cooperates with another form cylinder, not shown, so as to form a double printing for double-sided printing of the substrate 04.

The transfer cylinder 02 is connected to one or more elevators 05, z. B. one or more blankets 05, in particular one or more blankets 05 assignable and the forme cylinder 01 is with elevators 06, in particular printing plates 06, here two printing plates 06, in particular printing plates 06, assignable.

Depending on the requirements of the print formats and the printing performance as well as the possibilities in the paper guide, the cylinders are 01; 02; 03 different width (ie long) running. For example, the cylinders 01; 02; 03 be simply wide, double wide or triple wide. In commercial printing, for example, twice the width of the required width of the bale of the cylinder 01; 02 or 03 for four lying or six standing DIN A4 pages. The respective circumference of the forme cylinder 01, the transfer cylinder 02 and the impression cylinder 03 is, as mentioned above, in each case double, based on the respective format, but could also be formed, for example, quadruple or sixfold. The forme cylinder 01 could also have a simple circumference instead of the double circumference.

The forme cylinder 01 has a single pressure plate 06 in its axial direction. In the circumferential direction of the forme cylinder 01, a pressure plate 06 or a plurality, preferably two pressure plates 06 may be arranged.

The transfer cylinder 02 has at least one blanket 05, preferably two blankets 05. In this case, the blankets 05 may be arranged so that at least two or three and / or at least two blankets 05 are arranged in the circumferential direction in the axial direction.

The forme cylinder 01 has two channels 07 extending in the longitudinal direction and spaced apart by 180 ° in the circumferential direction. 08, z. B. depressions 07; 08 for receiving the ends of the printing plates 06. The transfer cylinder 02 has a substantially over the entire length of the transfer cylinder 02 extending channel 09, z. B. recess 09 for receiving the ends of the blanket 05 on. The end of such a blanket 05 is at a transfer cylinders 02 in the recess 09 by a fastening system, for. B. held a clamping and / or clamping device known per se.

The in the circumferential direction of the transfer cylinder 02; 12; 13 width seen Recess 10 in the surface of the elevator 05; 15 corresponds to that on the surface of the transfer cylinder 02; 12; 13 effective width of the channel 09; 19; 20th

The depth of the recess 10 provided in the elevator 05 corresponds at least to the static pressing of the elevator 05 in the pressure nip.

The channels 07; 08 of the forme cylinder 01 on the one hand and the channel 09 of the transfer cylinder 02 and the groove 10 in the blanket 05 on the other hand are so on the two cylinders 01; 02 arranged to rotate upon rotation of the two cylinders 01; 02 each on one of the channels 07; 08 or 09 or the groove 10 roll. After the offset of the channels 07 and 08 on the one hand and the channel 09 and the groove 10 on the other hand in each case is 180 °, roll after each 180 ° rotation of the cylinder 01; 02 a pair of channels 08; 09 and the channel 07 and the groove 10 from each other.

Due to the simultaneous channel overrolling in the gap defined by forme cylinder 01 and transfer cylinder 02 and in the gap defined by transfer cylinder 02 and impression cylinder 03, a reduction in the oscillation amplitudes is achieved by destructive interference, whereby oscillation amplitudes can be achieved that are significantly below those of simple channel overruns.

How out Fig. 1 recognizable are the axes of rotation of the three cooperating Cylinder 01; 02; 03 at least during the print-on position shown here on a common straight line, in particular in a common plane E, and parallel to each other. If the third cylinder 03 represents a further transfer cylinder and a further form cylinder cooperating with this further transfer cylinder is provided to form a double printing unit, the axis of rotation of this further forme cylinder lies in the plane E and parallel to the other axes of rotation.

Due to the arrangement of the channels 07; 08 and 09 and the groove 10 in the cylinders 01 and 02 and the unwinding of the channels 07; 08; 09 and the groove 10 in the manner described and additionally by the linear arrangement of the cylinder 01; 02; 03 in a plane E, the excitation of vibrations due to a channel strike is further reduced. Furthermore, especially in the (not shown here) case of a double printing unit by the synchronous and possibly symmetrical unwinding at the two printing units an additional destructive interference of the suggestions instead.

At least the transfer cylinder 02 is movable in a manner not shown, for example, along a linear travel from the on position shown in an off-position not shown. How out Fig. 1 the angle α, which the web of the printing stock 04 occupies with the plane E, is not equal to 90 °. The choice of the angle α, on the one hand, takes into account the rapid and secure release of the printing stock 04 and, on the other hand, minimizes negative influences on the printing result, which is decisively influenced by the extent of a partial looping of the transfer cylinder 02 or of the cylinder 03. Depending on the circumstances, the angle α is between 70 ° and 85 °.

It will now be based on the embodiment Fig. 3 Referenced. The illustrated here for example double printing unit for offset printing comprises a first cylinder 11, z. B. form cylinder 11, a cooperating with this first cylinder 12, z. B. transfer cylinder 12, a cooperating with this and a printing gap for the web-shaped substrate 04 forming second cylinder 13, z. B. transfer cylinder 13, z. B. impression cylinder 13 and a cooperating with this second cylinder 14, z. B. forme cylinder 14. The circumference of each of the cylinders 11; 12; 13; 14 corresponds to two or a multiple of two sides to be printed, and is preferably larger than 1,000 mm.

Instead of the cylinder pair 13; 14, which represents one of the two printing units of the illustrated double printing unit, can in principle also be a single cylinder acting as a counter-pressure cylinder, cf. Fig. 1 ,

Also in the case of this embodiment, the cylinder 11; 12; 13; 14 may be formed repeatedly wide. Furthermore, in the case of this embodiment, the rotation axes of all cylinders 11; 12; 13; 14 preferably arranged in a single plane E and parallel to each other. Also, in turn, the angle α occupied by the web of the printing substrate 04 with the plane E, not equal to 90 °, preferably between 70 ° and 85 °, and with regard to all these details will be to the description in connection with the first embodiment according to Fig. 1 and 2 directed.

While in the case of the embodiment according to Fig. 1 and 2 as a lift 05 for the transfer cylinder 02 a blanket 05 is provided, in the case of this embodiment, as elevators 15, z. B. blanket 15 for the transfer cylinder 12; 13 so-called metal blankets 15 per se known construction use, which have on a metallic base plate a druckfarbeneführende coating. The folded ends of such metal blankets 15 are in the transfer cylinders 12; 13 in recesses 19; 20, z. B. channels 19; 20, by fastening systems, for. B. clamping and / or clamping devices held in a known manner. Also, the folded ends of the printing plates 06; 16 are by fastening systems, for. B.

Clamping and / or clamping devices of a known type in the form of cylinders 11; 14 formed recesses 17; 18, z. B. channels 17; 18 held.

Preferably, both in the channels 19; 20 of the two transfer cylinders 12; 13 as well as in the channels 17; 18 of the two form cylinder 11; 14 the so-called "minigap" technology used, the channels 17; 18; 19; 20 are formed comparatively narrow and in such a narrow channel 17; 18; 19; 20 with leading edge a leading end of the respective elevator 15; 16 is used, the respective elevator 15; 16 on the cylinder 11; 12; 13 and 14 is wound, the trailing end also in the channel 17; 18; 19 and 20 is inserted and the ends against slipping z. B. be clamped by means of a rotatable spindle or a pneumatic device.

However, it can also be used both for the elevator 16 on the forme cylinder 11; 14 as well as for the elevator 15 on the transfer cylinder 12; 13 as a narrow slot 17; 18; 19; 20 executed channel 17; 18; 19; 20 be provided without clamping action, which the ends of the elevators 15; 16 takes up. The ends are in this case, for example, by their shape and / or the geometry of the slot in the slot 17; 18; 19; 20 held.

In the case of this embodiment, as seen in the circumferential direction of the transfer cylinder 12 and 13, two metal blankets 15 are used lying one behind the other. Each of the two metal blankets 15 extends substantially over the entire width of the associated transfer cylinder 12 or 13. This maximum paper web widths from currently (depending on the manufacturer) 1,600 mm to 2,120 mm in "Minigap" technology for all relevant Zylinderumfänge feasible. By narrow compared to conventional blankets channel of the metal blanket technology, the vibration amplitudes occurring in the channel beats are significantly reduced.

The channels 17; 18; 19; 20 are so on the associated cylinders 11; 12; Arranged 13 and 14 and in pairs offset by 180 ° and the cylinder 11; 12; 13; 14 roll off each other so that the channels 17; 18; 19; 20 adjacent cylinders 11, 12; 12, 13; 13, 14 roll each other in the respective gap. In this way, the destructive interference is additionally exploited in order to achieve a further reduction of the oscillation amplitudes. In this way, the oscillatory movements of the cylinder 12; 13 can be pressed even under those with the use of sleeves, as in sleeve machines, the vibration excitation through the channel of the forme cylinder can not be reduced by interference.

The two depressions 09; 10; 19; 20 at least one pair of transfer cylinders 02; 12; 13 have substantially the same dimensions, measured in the plane of the surface of the transfer cylinder 02; 12; 13th

The two depressions 09; 10; 19; 20 of each pair of transfer cylinders 02; 12; 13 have the substantially same dimensions, measured in the plane of the surface of the transfer cylinder 02; 12; 13th

In order to facilitate the laying of metal blankets 15 for large formats of the printing unit, a non-illustrated Auflegehilfe may additionally be provided, which may be designed as automatic or semi-automatic Aufhilfe.

If the transfer cylinder 12; 13 has a circumference of less than 1,000 mm, instead of two successively arranged metal blankets 15, a single metal blanket 15 of appropriate length can be used. This then has corresponding to the blanket 05 of the first embodiment, a parallel to its leading edge or trailing edge extending, approximately centrally between the two edges extending recess 10, which in on the transfer cylinder 12; 13 mounted metal blanket the (then single) channel offset by 180 ° opposite and whose width corresponds to the effective width of this channel.

In embodiments having a plurality of circumferentially successively arranged printing blankets, the invention can be realized accordingly by correspondingly many recesses are provided, which may be formed depending on the conditions of channels in the cylinders or additional recesses in the blankets, but always the surface of the Transfer cylinder with an even number of pairs offset by 180 ° wells such as channels in the bale, grooves in the elevator o. The like. Is equipped.

The invention thus provides a printing unit which, in order to avoid oscillation marks on the printing material, makes possible a reduction in vibration by destructive interference and at the same time fulfills the demand for a paper web to be printed centrally with a reduced web width. This is particularly the case for commercial presses with four A4 pages in the circumference (or two DIN A4-page presses in the periphery, which do not require DIN A3 production), but also for double-circumference newspaper presses in the American market, with which, for , As flyers are to be printed, of considerable importance.

The printing unit can be arranged downstream of a dryer.

The recess may be arranged in the blanket or in the bale of the cylinder, wherein the name in the bale also includes a recess in the possibly arranged between the blanket and bales documents.

"Essentially over the entire bale width" is to be understood as meaning at least 90% of the bale width and / or the entire bale width of the cylinder and / or the entire bale width minus possibly existing bearer rings.

By "substantially the same extent" is meant a deviation of at most 10% of the two circumferences of the cylinders of the same circumference.

LIST OF REFERENCE NUMBERS

01

Cylinder, forme cylinder

02

Cylinder, transfer cylinder

03

Cylinder, impression cylinder

04

Substrate, substrate web

05

Elevator, Blanket, Blanket (02)

06

Elevator, printing form, printing plate (01)

07

Channel, recess (01)

08

Channel, recess (01)

09

Channel, depression (02)

10

Groove, recess

11

Cylinder, forme cylinder

12

Cylinder, transfer cylinder

13

Cylinder, transfer cylinder, impression cylinder

14

Cylinder, forme cylinder

15

Elevator, blanket, metal blanket (12, 13)

16

Elevator, pressure plate (11; 14)

17

Recess, channel, slot (11; 14)

18

Recess, channel, slot (11; 14)

19

Recess, channel, slot (12; 13)

20

Recess, channel, slot (12; 13)

e

level

α

angle

Claims (19)

1. Printing unit of a printing press comprising at least one forme cylinder (01; 11; 14) and a transfer cylinder (02; 12; 13) and at least one counter pressure cylinder (03; 13), the transfer cylinder (02; 12; 13) and the forme cylinder (01; 11; 14) having substantially the same circumference, at least one packing (05; 15) fixed on the body of the transfer cylinder (02; 12; 13) being arranged, the at least one packing (05; 15) extending substantially over the total body width of the transfer cylinder (02; 12; 13), the forme cylinder (01; 11; 14) having, in its axial direction, a printing plate (06) extending substantially over the total body width of the forme cylinder (01; 11; 14), an even number of indentations (09; 10; 19; 20) offset in each case in pairs by 180° and running in the longitudinal direction of the transfer cylinder (02; 12; 13) being provided on the surface of the transfer cylinder (02; 12; 13), at least one of the indentations (09; 10; 19; 20) extending substantially over the total body width of the transfer cylinders (02; 12; 13), the forme cylinder (01; 11; 14) resting on the transfer cylinder (02; 12; 13) and a counter pressure cylinder (03; 13) likewise resting on the transfer cylinder (02; 12; 13) and forming a nip with said transfer cylinder being arranged, the packing (05) comprising a dimensionally stable support plate and at least one of the indentations (19; 20) being in the form of a deformation in the dimensionally stable support plate of the packing (15).
2. Printing unit according to Claim 1, characterized in that all indentations (09; 10; 19; 20) extend substantially over the total body width of the transfer cylinders (02; 12; 13).
3. Printing unit according to either of the preceding claims, characterized in that the two indentations (09; 10; 19; 20) of at least one pair of transfer cylinders (02; 12; 13) have substantially the same dimensions, measured in the plane of the surface of the transfer cylinder (02; 12; 13).
4. Printing unit according to Claim 3, characterized in that the two indentations (09; 10; 19; 20) of each pair of transfer cylinders (02; 12; 13) have substantially the same dimensions, measured in the plane of the surface of the transfer cylinder (02; 12; 13).
5. Printing unit according to any of the preceding claims, characterized in that the circumference of the surface of the transfer cylinder (02; 12; 13) corresponds to an integral multiple of four A4 pages.
6. Printing unit according to any of the preceding claims, characterized in that the at least one packing (05; 15) comprises at least one blanket (05; 15).
7. Printing unit according to Claim 6, characterized in that the blanket (05) is a rubber blanket (05).
8. Printing unit according to Claim 7, characterized in that the indentation (10) is formed in the surface of the rubber blanket (05) by cutting out the rubber coat in this area.
9. Printing unit according to Claim 6, characterized in that the blanket (15) is in the form of a metal blanket (15) which comprises a dimensionally stable support plate having at least one resilient layer formed thereon.
10. Printing unit according to Claim 1, characterized in that the circumference of the surface of the transfer cylinder (02; 12; 13) corresponds to an even number of pages to be printed.
11. Printing unit according to Claim 1, characterized in that the counter pressure cylinder (13) is formed by a further transfer cylinder (13).
12. Printing unit according to Claim 1, characterized in that the axes of rotation of the forme cylinder (01; 11; 14), of the transfer cylinder (02; 12; 13) and of the counter pressure cylinder (03; 13) are arranged on a straight line.
13. Printing unit according to Claim 11, characterized in that a further forme cylinder (14) rests on the further transfer cylinder (13), the axes of rotation of these four cylinders (11; 12; 13; 14) being arranged on a common straight line.
14. Printing unit according to either of Claims 12 and 13, characterized in that the straight line, in particular the plane (E) of the axes of rotation of the cylinders, is inclined at a non-90° angle (α) to the plane of a print substrate web (04) running through the printing unit.
15. Printing unit according to Claim 14, characterized in that the angle (α) is between 70° and 85°.
16. Printing unit according to Claim 1, characterized in that two printing plates (06; 16) are arranged in the circumferential direction of the forme cylinder (01; 11; 14).
17. Printing unit according to Claim 1, characterized in that a single printing plate (06; 16) is arranged in the circumferential direction of the forme cylinder (01; 11; 14).
18. Printing unit according to Claim 1, characterized in that at least two packings (05; 15) are arranged side by side in the axial direction of the transfer cylinder (02; 12; 13).
19. Printing unit according to Claim 18, characterized in that each of the packings (05; 15) arranged side by side has an indentation (09; 10; 19; 20) in the mounted state in the circumferential direction, in that each of the packings (05; 15) arranged side by side extends virtually over the total circumference of the transfer cylinder (02; 12; 13).

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