EP0812683B1 - Drive for a printing press - Google Patents

Abstract

A drive is provided for a sheet-fed offset printing press having multiple printing units. Each printing unit has printing cylinders which are independently driven. Transfer drums are driven mechanically uncoupled from the printing cylinders, and may be interconnected by a single gear train, or the transfer cylinders of each printing unit may be independently driven by a respective drive. Other rollers in the printing units may have individual controllable drives also. The invention minimizes disturbances caused by load fluctuations in conventional printing presses wherein the printing and transfer systems are mechanically intercoupled. The invention also is cost effective, particularly for register corrections. According to the invention, at least the plate cylinders are driven individually with respect to the sheet-transfer system or the corresponding blanket cylinder.

Description

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

In sheetfed offset presses, the sheets to be printed are from the top removed from a stack and conveyed to a system via a feed table. There, the aligned sheets are used, for example, by a pre-gripper detected, accelerated to the peripheral speed of the rotating cylinder and on hand over a first printing unit cylinder. The transport of the bow inside or between the individual printing units via the impression cylinders, Transfer cylinder or drums. After the last printing unit or the last one Finishing device downstream of the printing unit (coating unit or the like) the sheets are placed on top of a delivery stack. Such sheetfed offset printing machines usually have a continuous gear train on, by means of the printing cylinder mentioned and between the Transfer cylinders or transfer drums arranged with each other are coupled. Investors and cantilevers are also with the previously described Wheel train of the printing press coupled, in particular the feeder can also be stopped using a switchable clutch. With such Printing machines feed the required drive energy to or several feed points by one or more, in particular as a DC motor trained drive motors.

The cylinders used for sheet transport, the printing unit cylinders and the feeder as well as the delivery of sheetfed offset presses are very different current loads, in which the load torque in a significant manner depends on the position of the respective moving part. With the bow transport serving cylinders is due in particular to the controlled gripper systems for holding or releasing the sheets. The blanket cylinder / plate cylinder systems as well as blanket cylinder / impression cylinder are because of the periodically increasing and decreasing pressure zone contact also strong load fluctuations exposed. The sheet transport systems of a feeder and jib of a sheetfed offset printing machine also provide non-uniformly driven ones Loads. Since the ink supply in sheetfed offset presses is usually over an intermittent lifting roller takes place, which is caused by occasional contact with a first ink roller from one ink fountain roller to the other ink rollers of the inking unit, non-uniformities also become apparent at this point generated disturbances in the load moment.

A drive of DE 41 02 solves some of the problems described above 472 A1 by separating the main drive of the printing press in such a way that the units for the sheet transport (feeder, delivery) of separate individual drives to be served. A synchronization with the printing unit drives takes place electronically. However, this known device only avoids the periodic Load fluctuations caused by the feeder and boom. That in the printing units through the sheet transfer means as well as through the inking units caused load fluctuations and the disturbances caused thereby are not eliminated or their effects by this drive concept decreased.

From DE 42 41 807 A1 a drive for a printing press is known, in which the cylinders used for sheet transport as well as the printing unit cylinders and in particular the plate cylinders have a continuous gear train and are driven by at least one drive motor. Beyond that the elements that are not used for sheet transport, such as the inking units in particular assigned further drive motors, with a synchronization of the subsystems decoupled from one another by means of the encoder signals of the movement variables detecting control takes place. This facility avoids the negative Effects of, in particular, the interaction of the lifting roller torque fluctuations occurring with a first inking roller (friction roller) in the inking unit on the printing process. The disadvantage here is that the Plate cylinder mechanically with the continuous gear train of the other printing unit cylinders is connected, so that load fluctuations directly on the plate cylinder transmitted and cause corresponding interference. A disadvantage of this Setup is also that just in a multi-color sheetfed offset press the plate cylinders must have mechanically relatively complex devices for circumferential, side and / or inclined register correction. Beyond that it is for plate cylinders coupled directly to the other printing unit cylinders so-called pressure length compensation (pressure length correction) necessary, the corresponding To release printing plates from the plate cylinder and after placing them accordingly to reassemble strong underlay. Such operations are very time consuming and require great skill of the operator doing this.

EP 0 475 120 A1 discloses a high-speed ink feed mechanism, in which in the case of a lifter inking unit, the one downstream of the lifter roller the first inking roller (friction roller) is assigned its own drive. Thereby it is avoided that the load moment of the reciprocating jack roller has a negative effect on the rotation of the plate cylinder. The disadvantage of this Solution, however, that in the inking unit described in addition to a separate drive additional drives for the first inking roller after the siphon roller (friction roller) are to be provided. The inking unit described is only capable of to eliminate the pressure disturbances caused by the lifting roller movement, but not those influences caused by the sheet transport mechanism become.

The object of the present invention is therefore a drive for a printing press to expand in accordance with the preamble of claim 1 to avoid the above-mentioned disadvantages the best possible and in particular Achieve inexpensive drive solution to avoid pressure disturbances.

This object is achieved by the characterizing features of claim 1. Further developments of the invention result from the subclaims.

According to the invention it is provided that those associated with sheet transport Cylinders or drums as a whole through a continuous gear train or are driven in groups by at least one drive motor, and that in each printing unit at least the plate cylinder or blanket cylinder an individual and from sheet transport associated cylinders decoupled drive. In particular, be provided that the plate cylinder and that directly in contact with it stationary inking rollers (inking rollers) as well as these inking rollers subordinate inking rollers up to the first friction roller by the the drive connected to the plate cylinder. In this variant is the blanket cylinder interacting with the plate cylinder coupled with the gear of the respective impression cylinder, the Rubber blanket cylinders in the individual printing units assign additional individual drives which are appropriate to avoid tooth flank changes Apply braking torque to the respective blanket cylinder. The first of the inking roller Subordinate inking unit roller (friction roller) in the respective inking units the printing units also each have a single drive on.

In the previously described embodiment of the present invention, the cylinders or drums associated with sheet transport have a continuous one Gear train, which can be driven by at least one drive. In the respective The blanket cylinders are also meshed with the printing units assigned printing cylinders. As already mentioned above, the individual Rubber blanket cylinders additionally assigned individual drives through which the mentioned braking torques for the purpose of constant tooth flank system become. The plate cylinders assigned to the blanket cylinders are mechanical decoupled from these and each have a single drive. In In this case, position sensors are assigned to the blanket cylinders, by means of their Signals the drives of the plate cylinders in synchronous angular rotation with the associated Blanket cylinders are controllable.

Starting from the previously described implementation case of the invention, additional be provided, the power flow in the sheet transport serving To divide the cylinder or drum system according to the number of printing units. In such a case, each printing unit comprises, for example, an impression cylinder as well as an upstream and / or downstream transfer drum or one Feed drum, with both impression cylinder and transfer cylinder or Drum are coupled together by a gear train. Essential to this Realization form is that from printing unit to printing unit or from unit to unit none mechanical coupling exists, the power flow of those responsible for the sheet transport Cylinders or drums on the train of wheels within a printing unit is limited. In this case, the blanket cylinders of each printing unit can be coupled via gears to the associated impression cylinder and have their own to generate a constant tooth flank position Drive on. The plate cylinders in the printing units in turn run mechanically decoupled from the respective blanket cylinders and are being ejected Corresponding encoder signals (blanket cylinder) from a single drive each driven here. The inking units in the printing units include a single drive for the duct roller, a single drive for the first downstream of the lifting roller Inking roller (friction roller) and eventl. even more ink roller drives.

The two solutions described above have in common that the the blanket cylinders assigned to the individual printing units with the respective Back pressure cylinders are connected and are thus driven by this. The the individual drives assigned to the blanket cylinders either serve the purpose of Infeed of a corresponding braking torque to maintain a constant one Flank system of the gear drive between blanket and impression cylinder (Sheet transfer system - impression cylinder, transfer cylinder - also shows at least one own drive on) or the drive of the sheet transfer system, the one with continuous or split wheel train Sheet transfer system then does not have its own drive. Especially through the Always constant tooth flank system in the gear drive between blanket and Impression cylinder in the former case is the greatest possible freedom from interference in the image transfer between the rubber blanket and that on the printing material cylinder guided printed sheet achieved.

In the embodiment of the invention described above, in which the Plate cylinders in each printing unit mechanically decoupled by a single drive driven to the exact angular position synchronous to the respective blanket cylinder is, it is also possible by mechanically relatively simple means make a page and / or circumference register correction. Especially for a side register correction device must the respective plate cylinder in addition to the drive assigned to it can only be moved in the axial direction in the side frame walls be stored, the otherwise usual structurally complex Means to achieve said adjustment possibility are eliminated. A register correction in the circumferential direction by simply setting a phase in angular synchronism achieved between plate and blanket cylinders. Because between these cylinders there is no mechanical coupling, this measure is carried out purely electronically.

In a further embodiment of the invention, these are the printing material transport serving cylinders or drums with each other via a common gear train coupled. The blanket and plate cylinders are in the individual printing units each coupled via a pair of gears, by the associated one Counter-pressure cylinders decoupled and each with its own individual drive drivable. In this case, an angle encoder is assigned to each impression cylinder, whose signals to control the synchronism from blanket cylinder to impression cylinder evaluated via the correspondingly assigned drive motor become. The coupling of the blanket / plate cylinder system assigned The drive motor is preferably carried out directly on the blanket cylinder assigned gear, which with the corresponding gear of the plate cylinder combs. In this case too, there is no retroactive effect of the load fluctuations from the gear train assigned to the substrate guide to the printing unit cylinders (Blanket or plate cylinder). Analogous to that described above Case can also make scope and page register correction options easier Way to be accomplished. There is a side register adjustment device in this case from a common adjustment or displacement option of the Composite plate and blanket cylinder. A possibility to correct the circumferential register is also done electronically here by for the synchronization between Back pressure and blanket or plate cylinders have a corresponding phase relationship is specified electronically. In the inking units of the individual printing units in this case too is at least the first inking roller arranged downstream of the lifting roller (Friction roller) with a single drive.

fliegenden Plattenwechsel" durchzuführen.As a result of the plate cylinders which can be driven at least individually and independently of the rest of the cylinder system, in addition to the indicated correction possibilities in terms of printing technology (circumferential register, printing length compensation), other processes such as plate changing or washing the cylinders can also be carried out with greater flexibility. When the blanket cylinder is turned off (compared to the plate cylinder), it is thus possible to change the printing plates of the plate cylinders semi-automatically or fully automatically during printing in unused printing units or in all printing units by means of appropriate devices and to drive the plate cylinders in the appropriate manner. The drive system according to the invention also makes it possible to achieve a reasonable level of effort in sheet-fed printing machines

flying plate changes ".

Furthermore, three exemplary embodiments of the invention are explained with reference to Figures 1 to 3.

Embodiment 1

Figure 1 shows in principle the impression cylinder GD and the arranged in between Transfer drums T of a sheet-fed offset printing machine, not shown with a total of four printing units. The impression cylinders GD and the intermediate transfer drums T are with a continuous Wheel train coupled together. The impression cylinders GD and the transfer drums T for sheet transport are via a gear Z, which with the Gear wheel of the impression cylinder GD of the first printing unit meshes over one Reduction gearbox G driven by an ABT drive motor.

The plate cylinders PT and the blanket cylinders GT in the individual printing units each run decoupled from the associated impression cylinders GD (no gear connection), but are with each other (plate cylinder PT / blanket cylinder GT) connected to each other by a pair of gears. In each Individual printing unit is the system plate cylinder PT and blanket cylinder GT via one meshing with the gear of the rubber blanket cylinder GT Gear Z and a reduction gear G driven by a drive motor AGP. The rubber blanket cylinders GT as well as the interacting plate cylinders PT are in the frame walls of the printing press, not shown Achievement of a side and possibly inclined register direction adjustable. Alternatively to an inclinable register adjustment of the system plate cylinder PT / blanket cylinder GT can also use the transfer drums T in a manner known per se Be pivoted relative to the impression cylinders GD.

To achieve a high angular synchronism of the blanket cylinder GT the associated impression cylinders GD in the individual printing units the impression cylinder GD, as shown in principle in Figure 1, signal generator SG for example in the form of absolute or incremental encoders, so that from these Signals from the signal generator SG of the impression cylinder GD in the drive motors AGP of the individual printing unit-associated controls (not shown in FIG. 1) Control variables can be determined. The signals from the signal generator SG Counter pressure cylinders GD are thus in terms of one by the individual drives AGP synchronism of the rubber blanket cylinders GT (Plate cylinder PT) evaluated against the impression cylinders GD.

In the individual inking units of the printing units, the ductor rollers D also point a drive not shown in Fig. 1 and also the jack roller HW to produce an intermittent movement between the duct roller D and one of these subordinate first inking unit roller or friction roller R. In the exemplary embodiment according to FIG. 1, the friction roller R is also in each printing unit A drive AFW is assigned via a reduction gear G, so that these friction rollers R according to predeterminable speed values (under certain circumstances can be driven with slip compared to the other inking rollers). In addition can also use additional inking rollers of the indicated inking units in the printing units have individual controllable drives, but can also be provided be that certain inking rollers on wheel trains with the respective plate cylinders PT are connected.

A higher-level control S stands with the drives AFW of the friction rollers R, AGP drives of the blanket cylinder systems, which are individually driven in the printing units GT / plate cylinder PT and the drive ABT for sheet transport the continuous gear train of the impression cylinders GD and the transfer drums T in operative connection. The control concept is such that the individual systems rubber blanket cylinder GT / plate cylinder PT on each assigned drives AGP angularly synchronous directly via the signal generator SG assigned counter pressure cylinders GD, the drives AFW of the friction rollers R in the individual printing units according to predeterminable values of Movement quantities in the individual printing units follow. Since the drive ABT of the sheet guiding system of the impression cylinders GD and the transfer drums T connected to the controller S can in particular be freely selected Speed target values are specified.

Embodiment 2

FIG. 2 shows a sheet transport system as in the exemplary embodiment according to FIG. 1, consisting of the impression cylinders GD and the arranged in between Transfer drums T with continuous gear train. In this case, too this sheet transport system is driven by an ABT drive and a downstream one Reduction gear G by means of a gear Z, which with the meshes respective gear of the impression cylinder GD of the first printing unit. The blanket cylinders GT are in this embodiment via a pair of gears with the sheet transfer system, i.e. the respective impression cylinders GD of the individual printing units connected. In addition, the rubber blanket cylinders GT in the individual printing units individually controllable drives AG, which via a Reduction gear G and a downstream gear Z with the respective Gear of the blanket cylinder GT are connected. Through the blanket cylinders GT assigned drives AG is by default corresponding Control variables a constant tooth flank system of the gear pairings achieved between the blanket cylinder GT and the impression cylinder GD (Supply of a predetermined braking torque). The plate cylinder PT in the individual printing units are mechanically decoupled from one another with respect to the associated ones Rubber blanket cylinders GT and are in turn via a gear Z, which meshes with the respective gear of the plate cylinder PT and a reduction gear G controlled by an assigned drive AP for angular synchronism driven with respect to the associated blanket cylinder GT. How In the exemplary embodiment described above, the friction rollers R also have here one AFW drive in each printing unit. The same goes for the Ductor roller D and the indicated lifting rollers HW.

In embodiment 2, the plate cylinders PT run individually driven opposite each other the blanket cylinders GT and the impression cylinders GD des Sheet transfer system. By specifying appropriate control parameters of a higher-level one Control S, in which in particular the DC intermediate circuits can be summarized, the plate cylinder PT are particularly with regard the correction of pressure length differences or the register can be controlled. As indicated in Figure 2, the drives ABT, AG, AP and AFW are available the controller S in connection, so that appropriate actuation commands for the purpose Angular synchronicity or deliberate deviation from angular synchronism or intended speed differences in the respective driven systems are executable.

Embodiment 3

In embodiment 3 according to Figure 3, the components are blanket cylinders GT, plate cylinder PT and the cylinders / rollers of the associated inking units in the individual printing units driven in the same way as in Embodiment 2 described above. In contrast, the drive takes place the sheet transfer system, i.e. the individual impression cylinders GD and the intermediate transfer drums T not by a continuous one Wheel train, but per impression unit are the impression cylinders GD and the associated transfer drums T connected to each other with a gear train, whereby no mechanical coupling is provided from printing unit to printing unit. As a result, each system consists of an impression cylinder GD and associated transfer drum T connected to a single drive ABE the drives ABE each via reduction gears G and corresponding Gears Z on the gears of the impression cylinders GD (in the printing units) upstream transfer drums T (like embodiment 2) of the individual Act printing units. The ABE drive of the first printing unit takes place via a feed drum ZT upstream of the impression cylinder GD, via which sheets are fed from a system, not shown, to this first printing unit become. Like the transfer drums T, the feed drum ZT is also through Gear engagement connected to the impression cylinder GD.

In example 3, corresponding movement commands are also specified by a higher-level controller S, which also does not receive the signals from Signal transmitters shown further (angle encoder / incremental encoder) supplied become. This embodiment has the advantage that the synchronization of the individual systems impression cylinder GT / transfer drum T in the printing units can be done by a so-called virtual master axis, therefore by default corresponding movement commands / movement quantities assigned to the printing units ABE drives can be regulated in synchronism. It happens in this case then a regulation of remaining deviations of the actual actual positions (Signal generator) with regard to the movement specification according to the virtual one Leading axis.

In embodiments 2 and 3 it can further be provided that the drive the impression cylinder GD and the interacting (coupled) cylinders Transfer cylinder T via the drives AG of the connected to the impression cylinders GD Blanket cylinder G takes place in the individual printing units. In this The continuous or split sheet transfer system GD, T has no case own drive ABT or no own drives ABE.

Reference list

DG

Impression cylinder

T

Transfer drum

D

Duct roller

HW

Lifter roller

R

Grater roller

G

Reduction gear

AFW

Inking unit roller drive (R friction roller)

PT

Plate cylinder

GT

Blanket cylinder

AGP

Drive (rubber blanket cylinder GT / plate cylinder PT)

SG

Signal generator

DEPT

Drive sheet transfer system (impression cylinder GT / transfer drums T)

AP

Drive (plate cylinder PT)

AG

Drive (rubber blanket cylinder GT)

ABE

Drive sheet transfer unit (printing unit)

S

control

Claims (9)

1. Drive for an offset sheet printing press in which the cylinders or drums (GD, T) of one or several printing units connected with one another via a gear train can be driven by at least one drive (ABT, ABE) acting on the gear train and controllable drives (AT, AG) are fitted to the components (GT, TP) not driven via the gear train, characterised in that in each printing unit, at least the plate cylinder or blanket cylinder (PT, GT) are arranged mechanically decoupled from the drive train of the cylinders or drums (GD, T) taking part in sheet transport and is drivable via in each case a coordinated drive (AP, AGP) in preset fashion relative to the remaining cylinders or drums (GT, GD, T).
2. Drive according to Claim 1, characterised in that each plate cylinder (PT) is drivable mechanically decoupled with respect to the respective blanket cylinder (GT) and has, in each case, a separate drive (AP) and that each blanket cylinder (GT) is connected via a gear drive with the corresponding impression cylinder (GD).
3. Drive according to Claim 2, characterised in that each blanket cylinder (GT) connected via a gear drive with the impression cylinder (GD) has in each case a separate drive (AG) for introducing a braking moment effecting a maintained tooth flank positioning with respect to the drive power in the gear train of the cylinder or drums (DT) of the sheet transport having at least one drive (ABE, ABT).
4. Drive according to Claim 2, characterised in that each blanket cylinder (GT) connected via a gear drive with the impression cylinder (GD) has in each case a separate drive (AG) and that the drive of the cylinders or drums (GT, T) effecting the sheet transport takes place via the drives (AG) of the blanket cylinder (GT).
5. Drive according to Claim 1, characterised in that in an offset sheet printing press, the plate cylinder (PT) and blanket cylinder (GT) are linked with one another via at least one pair of toothed gears and are drivable in each case by a drive (AGP) fitted thereto which is decoupled with respect to the remaining cylinders (GD, T).
6. Drive according to one of the preceding Claims, characterised in that the cylinders or drums (GD, T) effecting the sheet transport of the individual printing units are connected together with one another via a closed gear train and can be driven by at least one drive (ABT, AG) acting on the gear train.
7. Drive according to one of Claims 1-3, characterised in that in each printing unit, the cylinders or drums (GD, T) decoupled from the cylinders of the further printing units are connected with one another via a gear train and are drivable in each case by means of a drive (ABE, AG) fitted to and acting on the gear train of the respective printing unit.
8. Drive according to one of the preceding Claims, characterised in that in each printing unit, the plate cylinder (PT) or the plate cylinder (PT) and the blanket cylinder (GT) can be driven with respect to the remaining cylinders for carrying out peripheral register corrections.
9. Drive according to one of the preceding Claims, characterised in that in each printing unit, the plate cylinder (PT) and/or blanket cylinder (GT) can be driven for carrying out print length corrections with respect to the remaining cylinders.

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