DE102004022085B4 - Method for controlling and / or regulating the printing speed during startup, up and / or shutdown of a printing press - Google Patents

Abstract

Method for controlling and / or regulating a printing speed when starting, starting and / or shutting down a printing press along a stored characteristic curve, characterized in that at least two different characteristic curves (13, 13 ', 16, 16', 16 '') lead to the upward stroke - and / or shutdown of the printing press are provided; the printing press being set up to switch between the different characteristic curves as a function of a print quality during the start-up and / or shutdown of the printing press.

Description

The invention relates to a method for controlling and / or regulating a printing speed during startup, up and / or shutdown of a printing press according to the preamble of patent claim 1.

It is generally known to increase the printing speed when starting a printing press after a fixed predetermined start-up characteristic. In this case, all facilities involved in the printing process of the printing press are approached accordingly. This fixed start-up characteristic is a compromise that takes into account the different operating conditions of the printing press and therefore does not lead to optimal results for anybody. This leads to different printing qualities when starting and stopping the printing press, so that the printed products do not fulfill the specified requirements and have to be disposed of as so-called waste paper.

From the publication DE 198 01 871 A1 For example, a method for controlling the speed change of a printing cylinder of a printing press is known.

In the publication DE 196 43 252 A1 a control for driving a printing press is described.

The publication DE 196 39 134 A1 discloses a method for starting / restarting the continuous printing in a sheet-fed printing press.

From the publication JP 2000071427 A An apparatus for accelerating and decelerating a printing press is known.

Out DE 103 02 747 A1 For example, a method is known for correcting variations in the amount of ink transferred to the printed image during the printing process.

From document DE 100 23 625 A1 For example, a passer control system is known that allows for fast and precise control of the movement of a web of a web processing machine for any web velocity profile.

The object of the invention is to provide a method for controlling and / or regulating the printing speed when starting, up and / or shutting down a printing press.

This object is achieved by the features of claim 1.

In an inventively equipped printing machine, only a minimal amount of waste paper is advantageously produced during startup and shutdown. With a printing press according to the invention, it is furthermore possible with advantage to produce good copies as the printing speed changes.

Other features and advantages will become apparent from the dependent claims in conjunction with the description.

The invention will be explained in more detail with reference to the accompanying schematic drawings. The

1 shows the shutdown and start up of a printing press for blanket washing according to the prior art and

2 represents an inventive shutdown and startup of a printing press.

Out 1 shows how a printing machine, in particular a web-fed printing press, is shut down for washing the printing devices. In the diagram, the printing speed n or the rotational speed of the printing cylinder is plotted over the time t. The characteristic curves shown symbolize the corresponding activation of the associated drives in order to set the illustrated decelerations, accelerations or printing speeds on the printing press.

After the production of a certain amount of good copies 1 becomes the printing speed along a predetermined in the machine control Abfahrkkelinie 4 braked. With the start of shutdown the print quality decreases and the print products have to be wasteed 2 be disposed of. During the cleaner 3 the printing equipment drives the printing press at washing speed 6 , Once the washing process 3 is completed, the printing machine along a predetermined in the machine control Hochfahrkennlinie 5 be accelerated again to the speed of production for the production of good copies, ie printed products with the specified product quality. During shutdown and washing 3 and when booting the printing press results in a waste quantity 7 , which depends on the duration of the washing process and the printing speed driven thereby.

In 2 is the shutdown and startup of a printing machine according to the invention by way of example during washing 3 illustrated by a speed-time diagram. During the production of good copies 1 the press will go along a first - in the machine control stored - shutdown characteristic 13 braked. The shutdown characteristic 13 Delays the printing speed or the rotational speeds of the printing cylinder so slowly that the print quality does not or only slightly decreases and the printed products can be sold as good copies.

To further reduce the amount of waste, it is particularly advantageous that the transition 12 between the printing speed and the deceleration curve 13 continuous. Preferably, the transition 12 designed in the form of a rounding, in which the continuous printing speed enters tangentially and the characteristic curve 13 tangentially, thereby avoiding a sudden transition from run to shutdown. As a result, the printing process is not disturbed by the deceleration. The transition 12 can be done within a variable time. Preferably, a transition rounding is provided within a time of two to five seconds.

If the print quality when shutting down along the curve 13 however, decreasing so that waste is produced may result in another shutdown characteristic stored in the machine control 13 ' change. This is preferably much steeper, ie it delays the printing speed more than the characteristic curve 13 and the press achieves the washing speed faster 14 , This will reduce waste 18 produced.

When reaching the washing speed 14 can do the washing 3 kick off. After completion of washing 3 can the press along a startup characteristic 16 be accelerated to print speed. The startup characteristic 16 accelerates the printing press so slowly that the settling control processes at the printing devices are not disturbed and good copies are produced at startup.

To further reduce the amount of waste, it is particularly advantageous continuous transitions 15 . 17 from the washing speed 14 for acceleration 16 as well as the startup speed 16 to provide for the printing speed, as already described in connection with the shutdown.

If the print quality at startup is in accordance with the startup characteristic 16 so worsened that waste 10 can produce a steeper characteristic 16 ' be changed, by which the printing speed is increased faster. As soon as the printing process has stabilized so far that good copies can be produced, this can lead to a further flatter characteristic curve 16 '' be changed to ensure that the printing process remains stable.

The amount of waste produced during the shutdown and startup of the printing press according to the invention 18 is much lower than the prior art.

An essential core of the invention is then to see that for raising and / or shutting down a printing press several startup or shutdown curves are provided with different gradients, depending on whether waste or copies are produced, the press quickly or slowly in the Continuing pressure or to convert into the washing speed. Another essential core of the invention is to be seen in that the transient processes of the control processes of the printing devices are not disturbed by the rounding of the transition points from the print run to a Abfahrkennlinie and / or from a Hochfahrkennlinie to the production. Thanks to the smooth transition - without any discontinuity - the printing process remains stable, resulting in less paper waste.

According to the invention, a plurality of characteristics with different gradients for the upshift and / or shutdown can be stored in the control / regulating devices of a printing press and selected freely. It can also be provided means for adjusting the slopes of the curves.

The choice of a characteristic curve can be made depending on the position of a waste gate. In the switch position "net on", d. H. Start-up with production of good copies and closed waste gate, a flat characteristic can be controlled and with "net out", ie. H. Starting up with the waste gate open, a steep characteristic curve can be activated for faster acceleration. The same applies mutatis mutandis to the deceleration of the machine.

It can also be controlled to change to a steep characteristic when an open waste gate is detected.

In conjunction with a sensor arrangement for determining the print quality, it is also possible to regulate the slope of the characteristic or to make the selection of the characteristic automatically. The selection of the characteristic can be done, for example, depending on a flag or a switch position for good copies / waste.

In the case of the highest demands on print quality, which according to experience no good copies can be achieved at startup, a steep run-up characteristic can be preselected so that as little waste as possible is produced during startup.

For medium quality requirements, for example, a flat run-up characteristic can be preselected, so that even at startup good copies can be achieved.

For recurring print jobs, the optimal characteristics stored in conjunction with other meaningful parameters can be recalled for the next production.

LIST OF REFERENCE NUMBERS

1

Gutexemplare

2

wastepaper

3

To wash

4

Shutdown characteristic

5

Start-up characteristic

6

washing speed

7

Macular Tower Close

10

wastepaper

11

Gutexemplare

12

Checkpoint

13

Shutdown characteristic

14

washing speed

15

Checkpoint

16

Start-up characteristic

17

Checkpoint

18

Macular Tower Close

n

print speed

t

Time

Claims (7)

Method for controlling and / or regulating a printing speed when starting, raising and / or shutting down a printing press along a stored characteristic curve, characterized in that at least two different characteristic curves ( 13 . 13 ' . 16 . 16 ' . 16 '' ) are provided for raising and / or lowering the printing press; wherein the printing machine is arranged to switch between the different characteristics as a function of a print quality during the up and / or shutdown of the printing press. Method according to Claim 1, characterized in that the different characteristic curves ( 13 . 13 ' . 16 . 16 ' . 16 '' ) are variable with respect to their slope. Method according to one of the preceding claims, characterized in that a selection of one of the different characteristic curves ( 13 . 13 ' . 16 . 16 ' . 16 '' ) takes place in response to a flag or a switch position for good copies or waste. Method according to one of the preceding claims, characterized in that a sensor arrangement is provided for monitoring the print quality. Method according to one of claims 1 to 4, wherein at least one of the at least two different characteristics ( 13 . 13 ' . 16 . 16 ' . 16 '' ) a transition ( 12 . 15 . 17 ) for accelerating and / or having a transition for delaying the printing speed and / or a transition to a printing speed in the form of a rounding. A method according to claim 5, characterized in that the transition in the form of the rounding between the different characteristics ( 13 . 13 ' . 16 . 16 ' . 16 '' ) takes place within a variable time. A method according to claim 5 or 6, characterized in that the transition takes place within a time of two to five seconds.

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