EP0950519B1 - Method for self-adjusting the printing and the cutting register in rotary printing machines with several webs - Google Patents

Abstract

In the printer control, relative track expansion values are calculated from the current operating point of the respective drive and the path distance to the next drive for each paper transporting drive. Correction values are calculated by combining all of the calculated values. Guide parameters for the color and stage register are then corrected according to the correction values.

Description

Technical field

The invention relates to the field of printing technology. It goes out of a method for self-adjusting color and cut register control in rotary printing presses with single or multiple webs according to the Preamble of the first claim.

State of the art

The invention is particularly advantageous for shaftless rotary printing presses used. A shaftless rotary printing machine with pairs rubber blanket and plate or Forme cylinders are described in DE 43 44 896 A1. A process of regulation the drive for the transport of a paper web of a printing press, which is particularly suitable for shaftless rotary printing machines the unpublished European patent application no. 98101727.0. According to this method, the speed control of the web train determining Elements depending on a load torque as specified a load characteristic curve lowered or raised, so that the drive at the same time the command variables speed and drive torque or web tension and that the master setpoint compensates according to the load characteristic becomes.

A major advantage of individually driven rotary printing machines is that these machines are capable of changing products machine running. With the European in the above The methods described in the patent application are the web tension changes, due to the starting and stopping required when changing the product of pressure points and when changing paper types while the machine is running usually arise, largely avoided. The achieved with it Stability with regard to the transport of a paper web of a printing press is excellent.

Despite the excellent stability regarding the transport of a paper web becomes a problem especially when changing products or changing paper types not or only partially solved with the machine running, namely the Positioning of the color and cut registers that determine print quality.

• bei Anfahrvorgängen die Führungsgrössen auf fixe Referenzwerte gestellt werden und dadurch häufig manuelle Eingriffe durch die Drucker erfordern.
• die Messglieder erst auf die Dehnung der Papierbahn reagieren.
• die Reaktionszeit der Messung aufgrund der Totzeiten beim Transport der Bahn bis zum Messglied, bei der Analyse und der Datenübertragung zur Steuerung typisch 2s beträgt und die Güte der erfassten Istwerte von der Laufruhe der Bahn abhängt.
• die Zug- / Dehnungsverhältnisse einer gesamten Produktion mit mehreren Bahnen durch Rückwirkung der über die gemeinsame Sammelwalze laufenden Bahnen untereinander erheblich beeinflusst werden.

According to the state of the art according to FIG. 2, color and cut registers are influenced by independent measuring elements, in that the control variables detected by the measuring elements are switched on to the positioning guide variables and thus adjust the individual actuators with regard to color registers and all together with regard to cutting registers. In the case of divided webs, the cutting register is set by means of additional actuators (secondary register) (not shown). The disadvantage of these facilities is that:

• When starting up, the command variables are set to fixed reference values and therefore often require manual intervention by the printer.
• the measuring elements only react to the stretching of the paper web.
• the reaction time of the measurement is typically 2s due to the dead times during the transport of the web to the measuring element, during the analysis and the data transfer to the control, and the quality of the actual values recorded depends on the smoothness of the web.
• the tensile / elongation conditions of an entire production with several webs can be significantly influenced by the interaction of the webs running over the common collecting roller.

Conclusion: With the state of the art, you leave an inaccuracy at first the register guide in terms of color and cut before you get relative has a sluggish effect on the command variables via additional measuring elements.

Presentation of the invention

The object of the invention is therefore a method for self-adjusting Specify register control in rotary printing presses with multiple webs at what influencing factors on the color and cut register, such as a change of paper type or the content of the printed product while it is running Machine, dry or damp paper, different number of pressure points per paper web, different paper lengths, etc. in all possible Operating modes of the machine are recorded at the origin and controlling the Apply setpoints for the color and cut registers. Each tension element of the Paper web is advantageously via a control device according to the mentioned unpublished European patent application operated.

The essence of the invention is that a correction value from the operating points, i.e. especially from the current speed of rotation and the torque, the servomotors for the tension elements of the paper web are calculated and the Reference variables for positioning the color and cut registers are activated becomes. The operating points of the actuators react extremely quickly Changes in paper properties, resulting in a high dynamic with short Response times for influencing the register results. Because the web length of the sections between the tension elements of the paper webs of a running one Production are known, a measure of the relative paper elongation calculate per section from the operating points of the drives and in Activate the register individually in the form of a correction variable. Although that concrete influence of these correction parameters on the color and cut register is different, the procedure remains the same for both registers same.

When changing the content of the printed product while the machine is running are both the current and the next rail routes Production known. Thus, the influence of the new railway lines on the registers immediately when changing production according to the invention Procedure.

• durch die gesteuerte Korrektur aller Register ein insgesamt konstantes Verhalten der Papierbahnen resultiert.
• die Farbregister aufgrund der gesteuerten Einflussnahme reaktionsschnell voreingestellt werden,
• die Schnittlage aufgrund der gesteuerten Einflussnahme auf alle die Schnittlage bestimmenden Bahnzugelemente reaktionsschnell voreingestellt werden.
• durch eine verbesserte Farb- und Registereinhaltung in allen Phasen des Betriebs weniger Makulatur erzeugt wird,

Compared to the operation according to the state of the art, there are significant advantages in particular when changing the paper type or the content of the printed product while the machine is running

• The controlled correction of all registers results in an overall constant behavior of the paper webs.
• the color registers are quickly preset based on the controlled influence,
• the cutting position can be preset quickly in response to the controlled influence on all web tension elements determining the cutting position.
• Less waste is generated in all phases of operation thanks to improved color and register maintenance,

The printing process is thus easier to control overall. More beneficial Embodiments result from the corresponding dependent Claims.

Brief description of the drawings

The invention is described below with reference to exemplary embodiments in Connection with the drawings explained in more detail. Show it:

Fig. 1 is a schematic representation of the rotary printing press several lanes and the machine elements driving the lane.

Fig. 2 is a schematic representation of the color and cut position control According to the state of the art. Here are only the elements of one side of the web shown; the representation applies analogously to the rear of the web.

Fig. 3 is a schematic representation of the color and cut register control according to the inventive method. Here are just the elements a web side represented by a web; the representation applies analogously to the back of the web and all other webs.

The reference symbols used in the drawings and their meaning are summarized in the list of reference symbols. Are basically In the figures, the same parts are provided with the same reference symbols.

Ways of Carrying Out the Invention

Figure 1 shows a schematic representation of the rotary printing press with several webs and the machine elements driving the web. The paper guide or paper web is the web that the paper to be printed on from the roll change 1 via the pendulum roller 2 and the pretensioner 3, via any combination of employed printing units 4 or parked printing units 5, via the pulling roller 6 and the hopper inlet pulling roller 7 to goes through to folder 8 in the folder. The pretensioner 3 controls the web tension and speed mainly within the web route L1 and thereby indirectly influences the color register accuracy of the printing units 4. The tension element 6 controls the web tension and speed mainly within the web route L2 and thereby indirectly influences the cutting position. The funnel infeed roller 7 controls the web tension and speed mainly within the merged web sections L3, L6, L9 and thereby indirectly influences the cutting position. The same naturally applies to the other railways and rail routes L4 to L7. The merging of the webs on the hopper feed roller is not without reaction; here the converging webs exert a mutual influence with regard to web tension and speed.

FIG. 2 shows a control of the color and cut registers according to the state of the art. The main control variable W _v determines the rotation speed and position of all employed and switched off printing units 4 via control device R _D1 , R _D2 , R _D3 , R _D4 . The control devices contain individual ones Feedback for position and speed, which are not shown in the picture. The relative position of each printed color is recorded via measuring sensor 12 in the color register measuring system M _F and, as a control variable x _F1 , x _F2 , x _F3 , x _{F4, is} individually connected to the target values of the individual printing units. The picture shows only the facilities on one side of lane 9, 10 or 11; the illustration applies analogously to the rear of the web and to all webs. The cut position is detected by means of a sensor 13 shortly before the cut, the signal of which is fed to a cut register measuring system M _S , which determines the relative cut position of the web to the printed image either from printed register marks or by evaluating the position of the printed image. The relative cutting position acts as a correcting control variable x _s for the main control variable W _v .

The method according to the invention for self-adjusting color and cut register control for rotary printing machines with a plurality of webs is explained in more detail below with the aid of FIG. 3 . The devices according to the inventive method are designated KORR and KONF, the corresponding signals with k .. 3, the influences of the web back 9 and the other webs 10, 11 are only shown in summary. Thus k _{xn represents} the operating points of the servomotors and k _yn the correction _values for the control devices of all other elements involved in the transport of the train.

• die Führungsgrösse W_VW und Regler R_VW und Antrieb M die Regeleinrichtung für das Vorspannwerk,
• die Führungsgrösse W_D1 und Regler R_D1 und Antrieb M die Regeleinrichtung für das erste Druckwerk,
• die Führungsgrösse W_Dn und Regler R_Dn und Antrieb M die Regeleinrichtung ersatzweise für alle übrigen Druckwerke,
• die Führungsgrösse W_ZW und Regler R_ZW und Antrieb M die Regeleinrichtung für die Zugwalze,
• die Führungsgrösse W_SW und Regler R_SW und Antrieb M die Regeleinrichtung für die Trichtereinlaufzugwalze,
• Messfühler 12 und Farbregister-Messystem M_F das Messglied für die Farbregister,
• Messfühler 13 und Schnittregister-Messystem M_S das Messglied für die Schnittregister.

From Figure 3 it can be seen that the conventional color and cut register control was adopted in analogy to Figure 2; however, their use is optional and is not a requirement. It form:

• the command variable W _VW and controller R _VW and drive M the control device for the prestressing unit,
• the command variable W _D1 and controller R _D1 and drive M the control device for the first printing unit,
• the command variable W _Dn and controller R _Dn and drive M the control device as a replacement for all other printing units,
• the command variable W _ZW and controller R _ZW and drive M the control device for the pull roller,
• the command variable W _SW and controller R _SW and drive M the control device for the hopper feed roller,
• Measuring sensor 12 and color register measuring system M _F the measuring element for the color register,
• Sensor 13 and cutting register measuring system M _S the measuring element for the cutting register.

λ =

Bahnverlängerung in m

σ =

Zugbeanspruchung der Bahn in dN/m = f (Lastdrehmomente)

L =

Bahnstreckenlänge in m

E =

Elastizitätsmodul in N/m = f (Lastdrehmomente, Geschwindigkeiten)

These conventional devices are supplemented by devices according to the method according to the invention in that the main control variable Wv has the correction variable kys as a position offset for the cutting register and the individual printing units have the correction variable ky _Fl ... ky _Fn as a position offset for the color registers. The correction variables are calculated in the KORR module from the operating points of all drives, i.e. in particular the current rotational speed and the torque of those drives which are involved in the transport of the webs, i.e. from the drive for the leader 3, from the employed printing units 4, from the Pull roller 6 and from the hopper inlet pull roller 7 and, analogously, from all devices (not shown) of the back of the web and the other webs 10, 11. The drives react to changes in load torque by changing the drive speed and the web tension; a new drive operating point is thus set in the speed-web tension diagram. The working points k _xVW , k _xDl , k _xDn , k _xZW and k _{xSW recorded in this way} are explicitly shown in FIG. 3 for the top side of the web 9; they are recorded analogously for the _{rear of the web} and all other webs and are represented by k _xn . The paper stretch of the web, which is important for the register behavior, is related to the load torque according to a certain function and can be calculated - together with the length of the railway line to the next drive - directly from the operating point of the servomotor. The corresponding general formula for the amount of paper stretch is: λ = σ L E Here mean:

λ =

Web extension in m

σ =

Train tension in dN / m = f (load torques)

L =

Track length in m

E =

Elastic modulus in N / m = f (load torques, speeds)

k_ym =

m-te Korrekturgrösse, d.h. k_yFl...k_yFn, k_yS oder k_yn

KONF =

Konfigurationsdaten einer Produktion

k_xl =

Arbeitspunkt des ersten Antriebs einer Produktion

k_xm =

Arbeitspunkt des letzten Antriebs einer Produktion

The KORR module is used to determine the dimension for the paper stretch; the required track lengths for each production are known and are stored in the KONF module. The proportional influence of the recorded measure for the relative path stretching on the color and cut registers, ie the determination of the correction _values k _yFl ... k _yFn , k _yS , or k _yn , is also carried out in the KORR module using the machine configuration stored in the KONF module . This calculation of the individual correction variables is carried out according to the general formula k ym = f (CONF, k xl , ....., k xm ) Here mean:

k _ym =

_mth correction _variable , ie k _yFl ... k _yFn , k _yS or k _yn

CONF =

Configuration data of a production

k _xl =

Working point of the first drive of a production

k _xm =

Working point of the last drive of a production

The variables calculated in this way are shown explicitly in FIG. 3 for the upper side of the web 9; they are calculated analogously for the rear of the web and all other webs and are represented by k _yn .

If this method is applied to all drives driving the paper web as well as to all webs, conclusions can be drawn almost instantaneously about the effective paper properties of all webs and can be corrected using the correction _parameters k _yFl ... k _yFn , k _yS , or k _yn the reference variables for the color and cut registers act.

The KONF module does not only contain the machine configuration data for the current one, but also the data for the next production. The Application of the method according to the invention taking into account the Machine configuration data for the next production thus allows that when changing production with a changing paper type or printing point configuration this change simultaneously in the form of a correction to the relevant Reference variables for the color and cut registers can be switched on can. In terms of response time, this correction is many times faster than the register control according to the state of the art. The latter only serves to compensate for any residual errors. This results in a generally valid solution for all operating cases of a printing press for fast self-adjusting Color and cut register control.

Reference list

1

Reel changer

2nd

Pendulum roller

3rd

Leader

4th

Pressure point, employed

5

Pressure point, turned off

6

Pull roller

7

Hopper feed roller

8th

Folding knife in the folder

9

Lane A

10th

Lane B

11

Lane C

12th

Sensor for the registration of the color register

13

Measuring sensor for the detection of the cutting position

L1 ... L9

Railway lines between two driven machine elements

M

Actuator, consisting of converter and motor

W _v

Command variable machine speed / cutting position

W _VW

Command variable speed / position for the pretensioner

R _VW

Regulator for the leader

W _Dl ... W _Dn

Command variable speed / position for printing unit 1 or the Printing unit n

R _Dl ... R _Dn

Controller for printing unit 1 or printing unit n

W _ZW

Command variable speed / position for the pull roller

Rzw

Controller for the pull roller

W _SW

Command variable speed / position for the hopper feed roller

Rsw

Regulator for the hopper feed roller

CORR

Module for the calculation of correction values for color and cut registers

CONF

Configuration data of the machine for the current and the next production

k _xVW

Measure for the pre-tensioning unit working point

k _xDl ... k _xDn

Measure for the working points printing unit 1 or printing unit n

k _xZW

Measure for the working point of the pull roller

k _xSW

Measure for the working point of the funnel infeed roller

k _xn

Representative measure for the working points of all not shown driven machine elements

k _yS

Correction size cut position

k _yFl ... k _yFn

Correction size color register 1 or color register n

k _yn

Representative correction quantity for influencing all not shown Leading variables

M _F

Color register measuring system

M _S

Cutting position measuring system

x _p

Regular size of cut

X _Fl ... X _Fn

Standard size color register

λ =

Web extension in m

σ =

Train tension in dN / m = f (load torques)

L =

Track length in m

E =

Elastic modulus in N / m = f (load torques, speeds)

Claims (5)

1. Method for self-adjusting colour and cut register control in rotary printing machines having individual or a plurality of paper webs, the transport of the paper web being carried out essentially by means of individual drives spaced from one another by web section lengths, characterized in that relative web stretching values are calculated from the instantaneous operating point (k_xVW, k_xDl, k_xDn, k_xZW, k_xSW or k_xn) of the respective drive and the web section length as far as the next drive for each drive transporting the paper web, and in that, by combining all the web stretching values calculated in this way, correcting variables (k_yFl...k_yFn, k_yS or k_yn) are calculated, in accordance with which the command variables (W_V, W_VW, W_Dl...W_Dn, W_ZW, W_SW) for the colour and cut registers are corrected.
2. Method according to Claim 1, characterized in that the web stretching values are calculated according to the relation λ = σ · L E , with λ = web elongation in m; σ = tensile stress of the web; L = web section length in m; E = modulus of elasticity in N/m.
3. Method according to Claim 2, characterized in that the modulus of elasticity E is determined from the operating points of the involved drive as a function of the load torque and of the speed, and in that the tensile stress σ is determined as a function of the torque of the drives.
4. Method according to one of Claims 1 to 3, characterized in that the web section lengths for different productions are filed in a configuration data module (KONF).
5. Method according to Claim 4, characterized in that the command variables (W_v, W_VW, W_Dl...W_Dn, W_ZW, W_SW) are corrected proportionately, and in that corresponding proportion factors are determined on the basis of a machine configuration filed in the configuration data module (KONF).

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