DE102009045737B4 - Method for operating a printing machine - Google Patents

Abstract

A method for operating a sheet-fed printing machine, with at least one main drive (10) and with at least two printing units, each printing unit having at least one transfer cylinder (2), a forme cylinder (1) rolling on the transfer cylinder (2), an inking unit (4), preferably a The dampening unit (5) and an own drive (6) assigned to the forme cylinder (1) and independently drivable by the main drive (10), the respective forme cylinder (1) being motor-driven and synchronous to each of the main drive (6) in a continuous printing operation. 10) driven transfer cylinder (2) and impression cylinder (3) is driven, characterized in that the inking unit (4) of the printing unit (4) is shut down on a printing unit that is not involved in the production operation, and when the inking unit (4) is shut down, this printing unit is powered by its own drive ( 6) this printing unit generates a defined slip between its forme cylinder (1) and its transfer cylinder (2).

Description

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

From the prior art, namely from the EP 0 812 683 A1 , A sheet-fed printing machine with a plurality of printing units is known, wherein each of the printing units comprises an impression cylinder or impression cylinder, a rolling on the impression cylinder transfer cylinder or blanket cylinder, rolling on the transfer cylinder form cylinder or plate cylinder and an inking unit and a dampening unit. At least one sheet guiding cylinder is positioned between the counter-pressure cylinders of adjacent printing units.

In the sheet-fed printing machine disclosed therein, the counter-pressure cylinders, the transfer cylinders, the inking units and the dampening units of the printing units as well as the sheet guiding cylinders are driven by at least one main drive of the sheet-fed printing machine in the continuous printing operation. The cylinders of the printing units, however, are assigned as self-propelled self-propelled drives, which decouples the form cylinder in the continuous printing operation of the or each main drive of the sheet-fed press self-propelled.

After EP 0 812 683 A1 Consequently, the impression cylinders, the transfer cylinders, the inking units and the dampening units of the printing units are driven by the or each main drive under conditions of continuous printing conditions. The form cylinder of the printing units, however, are driven under continuous pressure conditions of the respective internal drives or direct drives, and synchronized to the or each main drive.

In order to drive the form cylinder of a printing unit using the corresponding self-propelled or direct drive synchronized to the main drive under production conditions, it is z. B. possible to regulate the direct drive of the forme cylinder such that a determined by means of a rotary encoder on the forme cylinder on the angular position of the forme cylinder with a determined using a further encoder on the transfer cylinder actual value of the angular position of the transfer cylinder, which is used as a target value for the angular position of Form cylinder is used, is charged in a control device to determine a manipulated variable for the direct drive of the respective forme cylinder.

The DE 101 60 559 A1 describes a method for operating a printing press, in which a forme cylinder is operated with a defined slip for the purpose of changing the printing plate relative to a blanket cylinder.

The inking unit of the respective printing unit not involved in the continuous printing operation is preferably stopped at a printing unit not involved in the continuous printing operation of the printing machine, for which purpose the inking unit is decoupled from the respective main drive of the printing press and the inking rollers of the inking unit are turned off from the forme cylinder on the forme cylinder. Then, when the inking unit is stopped at a printing unit not involved in the continuous printing operation, the load distribution in the drive train changes, so that the self-drive associated with the forme cylinder must be readjusted. Due to the control behavior of the self-propulsion, this can lead to a vibration excitation in the printing press, whereby the print quality can be adversely affected. The aim of the present invention is to avoid such print quality problems.

On this basis, the present invention has the object to provide a method for operating a printing press, with the above Probfen, with the above problems can be prevented. This object is achieved by a method according to claim 1. According to the invention, the inking unit of the same is set to a printing unit not involved in the continuous printing operation and generates a defined slip between the forme cylinder and the transfer cylinder of the printing unit when the inking unit is still set at this printing unit via the self-propulsion of the respective printing unit.

As a result, the print quality can be significantly improved.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings.

Showing:

1 : A schematic representation of a printing unit of a sheet-fed printing press to illustrate the method according to the invention.

Hereinafter, the present invention will be described with reference to FIG 1 for a trained as a sheet-fed printing press described, wherein 1 a printing unit of such a sheet-fed printing machine is shown schematically. So that includes in 1 illustrated printing unit of a sheet-fed printing press a form cylinder 1 , a transfer cylinder 2 and an impression cylinder 3 , on the one hand, the forme cylinder 1 and the transfer cylinder 2 and on the other hand, the transfer cylinder 2 and the impression cylinder 3 unroll. Furthermore, the printing unit comprises an inking unit 4 and a dampening unit 5 ,

Under continuous pressure conditions, at least the transfer cylinder 2 and the impression cylinder 3 such a printing unit of a main drive 10 driven. The form cylinder 1 on the other hand is a self-propelled drive designed as a direct drive 6 associated, the under impression conditions the form cylinder 1 of the printing unit drives self-motor, synchronized to the main drive 10 ,

To ensure this synchronized drive is the angular position of the forme cylinder 1 with the help of a rotary encoder 7 metrologically detectable and a control device 8th fed.

In the control device 8th is the one with the help of the rotary encoder 7 detected actual value of the angular position of the forme cylinder 1 comparable with a corresponding setpoint, wherein it is the target value for the angular position of the forme cylinder 1 one with the help of another rotary encoder 9 on the transfer cylinder 2 detected actual value via the angular position of the transfer cylinder 2 is. From this comparison of actual value and setpoint is in a control device 8th a manipulated variable, for the direct drive 6 of the forme cylinder 1 determined, but the same decoupled synchronously with the main drive 10 drive.

Then, when a printing unit of a sheet-fed printing machine is not involved in the printing operation thereof, the inking unit 4 the respective printing unit stopped, which is done by the fact that the inking unit 4 from the main drive 10 is decoupled and the on the forme cylinder 1 rolling inking rollers of the inking unit 4 from the form cylinder 1 be turned off.

Thus, if a printing unit is not involved in the continuous printing operation, then the inking unit 4 from the main drive 10 uncoupled and stopped, furthermore, the inking rollers of the inking unit 4 from the form cylinder 1 turned off, so they no longer on the form cylinder 1 roll.

With the present invention, it is now proposed, at such a not involved in the continuous printing printing unit whose inking 4 is stopped, on the self-propelled 6 of the forme cylinder 1 a targeted or defined slip between the forme cylinder 1 and the transfer cylinder 2 of the printing unit to produce. For this purpose, preferably via the self-propulsion 6 the respective printing unit of the form cylinder 1 the same driven so that the forme cylinder 1 and the transfer cylinder 2 have different peripheral speeds and / or different speeds.

Preferably, the forme cylinder 1 of the printing unit not involved in the printing process so driven that the forme cylinder 1 a lower peripheral speed than the transfer cylinder 2 and / or a lower speed than the transfer cylinder 2 having. It should be noted, however, that it is also possible for the forme cylinder to have a higher peripheral speed and / or higher speed for providing the defined slip between the forme cylinder 1 and transfer cylinder 2 drive.

With the inking set still 4 a printing unit not involved in the continuous printing operation is the form cylinder 1 the same over the direct drive 6 driven so that the between the forme cylinder 1 and the transfer cylinder 2 forming slip a Dehnschlupf in the contact zone between form cylinder 1 and transfer cylinder 2 causes. In particular, the slip between the form cylinder 1 and the transfer cylinder 2 the respective printing unit not involved in the printing operation, whose inking unit 4 is stopped, less than 1 per thousand.

It is therefore within the meaning of the present invention, on a printing unit whose form cylinder 1 can be driven by an engine, then when the printing unit with stopped inking 4 the same is not involved in the continuous printing operation of the sheet-fed press, via the self-propelled 6 of the forme cylinder 1 to drive the same so that between the forme cylinder 1 and the transfer cylinder 2 the respective printing unit targeted slippage in the order of Dehnschlupfs in the contact zone of bearer rings between form cylinder 1 and transfer cylinder 2 is set. As a result, printing problems can be avoided.

LIST OF REFERENCE NUMBERS

1

form cylinder

2

transfer cylinder

3

pressure cylinder

4

inking

5

dampening

6

Self-drive / direct drive

7

encoders

8th

control device

9

encoders

10

main drive

Claims (8)

Method for operating a sheet-fed printing press, with at least one main drive ( 10 ) and with at least two printing units, each printing unit having at least one transfer cylinder ( 2 ), one on the transfer cylinder ( 2 ) rolling cylinder ( 1 ), an inking unit ( 4 ), preferably a dampening unit ( 5 ) and a forme cylinder ( 1 ), from the main drive ( 10 ) independently drivable self-propelled ( 6 ), wherein in a continuous printing operation via the self-propelled ( 6 ) the respective form cylinder ( 1 ) self-powered and synchronous with each of the main drive ( 10 ) driven transfer cylinder ( 2 ) and impression cylinder ( 3 ) is driven, characterized in that at a not involved in the printing operation printing unit the inking unit ( 4 ) of the same is set still and with still set inking ( 4 ) at this printing unit via the self-propelled ( 6 ) of this printing a defined slip between the forme cylinder ( 1 ) and its transfer cylinder ( 2 ) is produced. Method according to claim 1, characterized in that by way of the self-propelled ( 6 ) of the printing unit not involved in the continuous printing operation whose form cylinder ( 1 ) is driven in such a way that form cylinder ( 1 ) and transfer cylinders ( 2 ) have different peripheral speeds. Method according to claim 2, characterized in that the forme cylinder ( 1 ) is driven in such a way that the forme cylinder ( 1 ) a lower peripheral speed than the transfer cylinder ( 2 ) having. Method according to one of claims 1 to 3, characterized in that for this purpose via the self-propelled ( 6 ) of the printing unit of the forme cylinder not involved in the continuous printing operation ( 1 ) is driven in such a way that form cylinder ( 1 ) and transfer cylinders ( 2 ) have different speeds. Method according to claim 4, characterized in that the forme cylinder ( 1 ) is driven in such a way that the forme cylinder ( 1 ) a lower speed than the transfer cylinder ( 2 ) having. Method according to one of claims 1 to 5, characterized in that when still set inking ( 4 ) of a printing unit not involved in the continuous printing operation via the self-propelled drive ( 6 ) of the printing unit not involved in the printing operation, a slip between the forme cylinder ( 1 ) and the transfer cylinder ( 2 ) of this printing unit is generated, which is a Dehnschlupf in the contact zone of bearer rings between the forme cylinder ( 1 ) and the transfer cylinder ( 2 ) causes. Method according to one of claims 1 to 5, characterized in that the slip between the forme cylinder ( 1 ) and the transfer cylinder ( 2 ) of the printing unit not involved in the printing operation is less than 1 per thousand. Method according to one of claims 1 to 6, characterized in that when still set inking ( 4 ) Inking rollers of the same from the respective forme cylinder ( 1 ) are turned off.

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