EP1114720A2 - Air conduit system for a sheet-fed printing machine - Google Patents

Abstract

Characteristic curves drawn using critical sheet conveyance parameters, plotted against optimal sheet parameter of specified printed are stored in memory. Actual specified sheet and printer specification data of print job are input to CPU. Based on the input data, CPU accesses optimum characteristic curve from the memory and outputs appropriate commands to individual actuators and allows operator intervention, if required. An Independent claim is also included for regulating and/or controlling device for air guide system.

Description

The invention relates to an air guide system in a sheet-fed printing machine. Such Air guidance systems serve to convey and direct the printing material, generally one Sheets of paper or cardboard. Such a system includes a variety of different ones air-assisted elements, such as blowing systems, air cushion and so on, in the In connection with this invention called "actuators".

The air guide system ensures precise conveying and guiding through the front edge Gripper held single sheet. It depends on the highest accuracy, and both the guidance, i.e. the avoidance of deviations from one by the gripper predetermined target path, as well as in terms of the timing. With the problems increase with increasing machine speed.

The universal usability of a machine for the thinnest papers (Bible printing paper) as well as the strongest cardboard requires a large one Setting range, and on the other hand an exact setting of the air parameters. In particular this applies to the pressure at the nozzle outlet and thus also the air speed and that Air volume. These air parameters are controlled by throttle valves or Bypass valves, remotely adjustable engine valves, speed controlled air generators and other more. The above-mentioned ones, which are decisive for sheet conveyance, must be used Parameters - hereinafter referred to as "funding parameters" - to the specific data of the respective print job can be set.

The bow-specific parameters

Sheet-specific parameters are in particular the weight per unit area, ie the weight of the sheet in g / m ² and the sheet format. However, other sizes are also possible, for example the stiffness of the arch or its surface quality. It goes without saying that the conveying parameters must be selected with regard to the sheet parameters in order to achieve an optimal result, that is to say that the sheet is conveyed perfectly through the entire machine. It can also happen that the parameters of a blowing air nozzle have to be changed at a certain point in the conveying path when changing the arc parameters (for example higher grammage) than in another place.

Printing press specific parameters

Printing press specific parameters are for the work of the
Blowing air nozzles crucial. The most important parameter specific to the printing press is the production speed, that is the machine speed. Other printing machine-specific parameters are the switching on and off of individual printing units, the presence of special inline applications: painting, drying, measuring, cutting ...

Combined parameters

Printing form, color assignment, moisture absorption change the printing material properties while running through the machine.

In previously known printing presses, the air parameters are the individual Air consumers, i.e. blow air nozzles, for example, can only be set individually. At most it is known to set groups of air consumers. In any case, one must large number of settings are made whenever a new one Print job (job) is executed with sheet-specific parameters opposite deviate from the previous print job, and / or with other press-specific ones Parameters, for example higher or lower Production speed.

From the plethora of all possible settings, the operator must choose the correct setting find out. The operator must therefore empirically adhere to the correct values of the Approach funding parameters in order to achieve a perfect funding result. there it is based on the physical and machine-specific sheet-specific as well as combined parameters. This not only requires a high level of skill on the part of the operator, but is also time consuming. The operator must move out of the Understanding of the technical-physical effect or from personal experience decide whether to optimize the delivery parameters, especially the air pressure Blower nozzles, corrections up or down are necessary.

Das Leistungsspektrum der Maschine wurde auf spezielle Anwendungen eingeschränkt, um dadurch eine Reduzierung der Einstellvorgänge von Förderparametern zu erreichen;

die Lufterzeuger wurden zur Vermeidung von Fehleinstellungen in ihrer Leistung begrenzt;

die Bedienstellen und Sichtfenster direkt neben der Bogenführungsbahn wurden ergonometrisch gestaltet;

Produktion mit verringerter Maschinengeschwindigkeit, denn im Tagesgeschäft einer Druckerei wurde meist die erhöhte Rüstzeit durch die dadurch erreichte höhere Fortdruckgeschwindigkeit nicht amortisiert.

The previous attempts at solution have consisted of the following:

The performance spectrum of the machine has been restricted to special applications in order to reduce the setting processes for conveying parameters;

the air generators were limited in their performance to avoid misadjustments;

the control points and viewing windows directly next to the sheet guideway were designed ergonomically;

Production with reduced machine speed, because in the day-to-day business of a print shop the increased makeready time was usually not amortized due to the higher production speed.

All of these attempts to solve the problem have been unsatisfactory in relation to the Time spent on the quality of the print result as well as in terms of Requirements for the skill and experience of the operator.

EP 0 553 321 B2 describes a device for regulating and / or controlling individuals Control elements such as blowing nozzles in the area of the delivery of a sheet-fed printing machine. there sheet and printing machine-specific data are fed into a computer. A control device takes a format-dependent one for individual control elements Setting before. The computer uses the characteristic data to determine the energy in the boom arriving sheet and also ensures that the control variables of the control elements apply just as much energy as the energy of the arriving in the boom area Arc corresponds.

DE 197 14 204 A1 describes a device for regulating the blown air on one Sheet feeder. Valves that control the blown air supply are due to Control characteristics are set, which in turn take the sheet properties into account.

DE 34 13 179 A1 describes a control and regulating device for a sheet delivery a sheetfed press. All necessary settings of adjustable elements of a sheet boom from a single point and automatically changing according to a given program Adapted to conditions.

All of these proposals were unable to solve the problems here. In particular, the consideration of parameters not contained in the database impossible, which basically leads to incorrect settings.

There is a fundamental contrast between Fully automated Manual setting + fast + flexible + no set-up times + universal - no possibility of intervention + maximum performance - never covers 100% of all parameters - Set-up time very long - many wrong settings - Done in the machine - not understandable for the printer not visible - The printer's experience base remains unused - possibility of error

The invention has for its object a method for setting a To create air guidance system for a sheet-fed printing press, in which the individual Delivery parameters of actuators such as blowing air nozzles quickly and automatically even by less experienced personnel for certain order data with special sheet-specific and press-specific parameters can be set (preset and Adjustment), and the manual influence is retained in such a way that the advantages a fully automatic with those of a manual control together with exclusion of the disadvantages can be used, so that an optimal printing result is achieved in the shortest possible time becomes.

This object is solved by the features of claim 1.

This enables the machine's performance to be optimized, the set-up times decrease, and quality as well as production performance from the subjective experience of Reach operators independently.

According to the basic idea of the invention contained in claim 1 are thus Characteristic curves are created, in which delivery parameters such as the air pressure over Printing machine-specific parameters such as the production speed for different print jobs with their sheet-specific Parameters such as the basis weight or the sheet format.

The characteristics mentioned therefore contain the data for the optimum setting for each a very specific substrate.

The air parameters are controlled by evaluating the arc and press specific parameters. This enables a preset. To adapt the machine to order-specific conditions, a Operator intervention on the respective data possible. This requires another size-here Called "influencing variable". This creates a changed characteristic, which then leads to others Air settings leads.

It is desirable that the preset setting cover all practical cases. In the In practice, however, this is not achieved. However, it is aimed to be a high one Percentage is recorded, for example 80%. In the remaining number of cases the printer must intervene and make an appropriate adjustment.

According to the invention, when creating the characteristic curves for the optimal Funding parameters are based on physical, "abstract" quantities, such as for example the basis weight or the stiffness or the format of the sheet.

• das Hochschlagen des Bedruckstoffes
• das Kontaktdoublieren des Druckbildes
• das Schmieren des Druckbildes
• das Flattern des Bedruckstoffes
• und anderes mehr.

In a further embodiment of the invention, however, it is provided that these variables be left aside and instead use very specific, result-related variables, such as

• folding up the substrate
• the contact duplication of the printed image
• the smearing of the printed image
• the flutter of the substrate
• and more.

The printer can reliably assess these conditions or phenomena. The he can do this with physical backgrounds and the effective variables to be combated completely disregard. The further teaching according to the invention thus consists in The following:

With the mentioned conditions or events such as beating up, Contact duplication, smearing, fluttering characteristic behavior of the Combination of physical parameters (basis weight, rigidity, centrifugal force and so on systematically and delivery parameters (blowing force, air volume, air pressure and so on) their effects recorded in experiments. The characteristic curves are then stored in such a way that the printer the results of changes as dual decisions of more (plus) or less (minus). He can therefore do without physical know-how Close the control loop in a qualified manner.

These typical and distinctive sizes could be either on their own or in addition to the physical quantities such as basis weight, stiffness and so on be used. This is beneficial in the case where there are a variety of parameters effects that cannot be recorded and evaluated in detail.

Example: The printer makes proofs and sets up a contact duplication in a certain amount in a certain place. He shares this observation Machine with. The machine has an algorithm or a characteristic curve. Because of it will then make a corresponding correction for the air system in question in the Machine.

Such a procedure is particularly recommended for repeat orders where job data storage of the type mentioned can take place.

Figur 1

veranschaulicht in schematischer Darstellung eine Bogendruckmaschine mit mehreren Druckwerken.

Figur 2

zeigt Kennlinien, dargestellt als Druck im Lufterzeuger über der Maschinengeschwindigkeit.

Figur 3

veranschaulicht ein Bedienkonzept bezüglich der Bogenführung.

Figur 4

zeigt eine Schar von Basis-Kennlinien.

Figur 5

zeigt eine ausgewählte Kennlinie bei dem Schritt "Preset".

Figur 6

veranschaulicht die Anpassung einer bestimmten Kennlinie.

Figur 7

veranschaulicht das unterschiedliche Ansprechverhalten einzelner Verbraucher bei Vornahme ein- und derselben Korrektur.

Figur 8

veranschaulicht das Geschehen bei Verändern eines Parameters, zum Beispiel des Flächengewichtes.

The invention is explained in more detail with reference to the drawing. The following is shown in detail:

Figure 1

illustrates a schematic representation of a sheet-fed printing machine with several printing units.

Figure 2

shows characteristic curves, represented as pressure in the air generator against the machine speed.

Figure 3

illustrates an operating concept regarding the sheet guidance.

Figure 4

shows a family of basic characteristics.

Figure 5

shows a selected characteristic curve in the step "Preset".

Figure 6

illustrates the adaptation of a specific characteristic.

Figure 7

illustrates the different response behavior of individual consumers when one and the same correction is made.

Figure 8

illustrates what happens when a parameter is changed, for example the basis weight.

The sheet-fed printing press shown fragmentarily in FIG. 1 has three printing units I, II and III. The sheets pass through the printing units in the order mentioned.

Each printing unit comprises an inking and dampening unit 1, a plate cylinder 2, and one Blanket cylinder 3 and an impression cylinder 4.

There is one between two successive impression cylinders Transfer facility. This comprises a gripping device 5 with two grippers 5.1, 5.2 curved sheet guide plate 6 and a number of blowing devices 7.

The individual arch is passed through the above-mentioned stations by means of a Guided air guidance system. For example, in the area of the transfer facility Sheet guide plates 6 arranged. In these are nozzles incorporated, which the bow through specifically emerging air flows on the sheet guide plate in a non-contact Transport floating position.

Furthermore, blowing devices 7 are arranged, which the sheets to be transported smooth the printing cylinder to ensure an optimal position of the sheet when printing ensure.

It goes without saying that further blow nozzles are provided, but not here needs to be received.

The diagram shown in FIG. 2 shows a number of characteristic curves. there means the characteristic curve "ACTUAL substrate" that determined for a current substrate Curve. A parameter is plotted on the ordinate that relates to the respective Air generator obtains, for example, the sizes mbar and rpm. On the abscissa is the machine speed, expressed in Prints per hour. Other critical parameters can also be considered.

Lüfterreihe

Schwebeführung

Papierblassystem vor Druckspalt
bezeichnen verschiedene Orte, an denen ein Lufteinsatz notwendig ist.

The headings above the diagram

Fan row

Levitation

Paper blowing system in front of the nip
denote different places where air use is necessary.

Figure 3 illustrates the operating concept of the sheet guide. The condition is at the top left illustrated during startup - see "Preset". The individual parameters are here pre-set.

The cake diagram illustrated in FIG. 3 below shows the following:
In an assumed case, the preset setting covers 80% of all practical cases. This means that in 80% of all cases the determined basic characteristics - see FIG. 4 - for a certain machine speed, for example expressed in pressures per hour, indicate the correct air parameters. But this also means that there are a number of cases where this is not the case. The printer must make an adjustment here. In practice, this means the following:

The printer assumes the preset setting mentioned and makes a few proofs forth. If the result is satisfactory, he does not need to make any adjustments. Is it but not entirely satisfactory, for example because it is associated with the Production speed increases, or because the special printing material is different than behaves as expected, the printer makes an adjustment ("Adjust" step).

In the case of the cake diagram shown, it was assumed that this was in 10% of all Cases will be necessary.

All air consumers are corrected with the Adjust step. The can individual air consumers are ordered to supply more or less air.

The "Tuning" step, on the other hand, affects influencing the air consumers within a machine relative to each other.

The diagram shown in FIG. 4 illustrates a plurality of basic characteristic curves. The ordinate is a measure of the use of the relevant Pressure gap blowing system for the sheet guide plate of a certain printing unit plotted, and the machine speed on the abscissa.

Each characteristic curve relates to substrates with very specific grammages, expressed in g / m ² .

This means that all air consumers in the machine are based on a stored characteristic curve set.

FIG. 5 illustrates a selected characteristic curve in the Preset step. The substrate has a basis weight of 90 g / m ² . The machine speed is 12000 prints / hour. The ordinate shows a value of 40% of the capacity of the air generator.

FIG. 6 illustrates the adaptation of the selected characteristic curve, that is to say that in FIG 5 characteristic curve represented by "Adjust", "Tuning", and "Expert".

The individual steps mentioned should be explained as follows:
Adjust:
On the basis of the printing result, the operator corrects the selected characteristic curve, that is to say the characteristic curve shown in FIG. 5. This correction is advantageously carried out by adapting the respective characteristic curve of all consumers (actuators) in the machine. It can be done, for example, by interpolation between the actual substrate and the next characteristic curve.

The step "Adjust" influences all consumers of the machine in a suitable way Wise.

Tuning:
The tuning is carried out on individual printing units or groups of printing units, for example on printing units 4 to 8 of a machine.

Expert:
The "Expert" step acts on a single actuator or on all similar actuators of the machine (for example on sheet guide plate 1 in printing unit 1 ... 8, for example).

Operator:
The "Operator" step enables you to enter the target setting of the respective actuator without switching on a characteristic (compensation off). The operator enters the value directly. This mode corresponds to operating a machine with throttling points.

Figure 7 illustrates the different claims behavior of different Consumers on a certain correction.

A)

Ein Verbraucher im kritischen oder stark übersetzten Bereich weist einen großen Unterschiedswert zu den benachbarten Kennlinien auf. Eine Änderung der Einflußgröße bedeutet hierbei eine große Änderung der Luftparameter. Siehe das linke Diagramm von Figur 7.

B)

Hingegen reagiert ein Verbraucher im unkritischen oder schwach übersetzten Bereich nur wenig auf die genannte Änderung. Siehe das rechte Diagramm in Figur 7. Dieser unkritische Bereich liegt zum Beispiel bei Bogenleitblechen vor. Dabei ist das Geschehen im rechten Diagramm in dessen umrandeten Bereich unten vergrößert dargestellt.

If the work of the air generator is corrected over the entire machine by one and the same amount, for example 5%, by pressing the plus or minus button, the actuators react differently depending on the stored characteristic field:

A)

A consumer in the critical or heavily translated range has a large difference to the neighboring characteristics. A change in the influencing variable means a large change in the air parameters. See the left diagram of Figure 7.

B)

On the other hand, a consumer in the uncritical or weakly translated area reacts little to the change mentioned. See the diagram on the right in Figure 7. This uncritical area is present, for example, with sheet guide plates. The events in the diagram on the right are shown enlarged in the bordered area below.

a) durch Aufnahme der nachstehenden zusätzlichen Einflussparameter in das n-dimensionale Parameterfeld, zum Beispiel:

• Grammatur (sogenanntes Flächengewicht)
• Format
• Steifigkeit
• Geschwindigkeit
• Bedienereingriff

b) durch Verändern eines Parameters, zum Beispiel des Flächengewichtes. Dies erfolgt vorzugsweise dann, wenn zum Reduzieren der Datenmenge mit nur wenigen Einflussgrößen gearbeitet werden soll. Siehe Figur 8. Dabei veranschaulicht das linke Diagramm das Soll-Kennlinienfeld, das mittlere Diagramm die Skalierungsfunktion, und das rechte Diagramm das Steuerungsfeld.

Eine weitere Größe neben der Maschinengeschwindigkeit - gegebenenfalls die einzige weitere Größe - wird nach einer vorgegebenen Regel (Skalierungsfunktion) in eine Hilfsgröße (0...100%) umgerechnet. Die Bedieneinflussgröße wird sodann hierzu einfach addiert, zum Beispiel 90 g/m² > 60 %; bei Korrektur 2 % plus > 62 %.

Die Skalierungsfunktion veranschaulicht, welche Auswirkungen das Justieren, das der Drucker vornimmt, bei den verschiedenen Grammaturen hat. Die Skalierungsfunktion trägt somit dem Druckstoffverhalten automatisch Rechnung. Das rechts dargestellte Steuerungsfeld ist das Ergebnis der Skalierungsfunktion.

The integration to solve the problem of operator intervention can be accomplished in different ways:

a) by including the following additional influencing parameters in the n-dimensional parameter field, for example:

• Grammage (so-called basis weight)
• format
• Stiffness
• speed
• Operator intervention

b) by changing a parameter, for example the basis weight. This is preferably done when only a few influencing variables are to be used to reduce the amount of data. See Figure 8. The left diagram illustrates the target characteristic field, the middle diagram the scaling function, and the right diagram the control field.

A further variable in addition to the machine speed - possibly the only other variable - is converted into an auxiliary variable (0 ... 100%) according to a predefined rule (scaling function). The operating influencing variable is then simply added to this, for example 90 g / m ² >60%; with correction 2% plus> 62%.

The scaling function illustrates the effects of the adjustment that the printer makes on the various grammages. The scaling function automatically takes the printing material behavior into account. The control field shown on the right is the result of the scaling function.

List of reference numbers

1

Ink and dampening system

2nd

Plate cylinder

3rd

Blanket cylinder

4th

Impression cylinder

5

Gripping device

5.1, 5.2

Gripper

6

Sheet baffle

7

Blow devices

Claims (4)

Method for setting an air control system, which has various actuators such as blowing air nozzles, in a sheet-fed printing press, with the following method steps: 1.1 Characteristic curves are created that contain relevant parameters for sheet conveying, such as air pressure, plotted against a press-specific parameter such as the press speed, and that are optimal for sheet-specific parameters such as the basis weight or sheet format; 1.2 the characteristic curves are stored in a memory; 1.3 the current sheet-specific and press-specific data of a print job are fed into a CPU; 1.4 the CPU takes the optimum characteristic curve for the current data from the memory and gives the individual actuators the corresponding commands; 1.5 If necessary, operator intervention is carried out. A method according to claim 1, characterized in that concrete conditions are determined when creating the optimal characteristic curves, such as Punch up the substrate Fluttering of the substrate Contact duplication of the printed image Lubricate the printed image Method according to claim 1 or 2, characterized by the following features: A diagram is created (scaling function), which shows the effects of the Adjustments in the various grammages and thus that Pressure behavior is taken into account. Device for regulating and / or controlling an air control system, which has various actuators such as blowing air nozzles, in a sheet-fed printing machine; 4.1 with a memory that contains characteristic curves that represent the relevant conveying parameters for sheet conveying, such as the blowing air pressure, plotted over printing machine-specific parameters such as the printing press speed, and which are optimal for sheet-specific parameters such as the basis weight or the sheet format; 4.2 with an input device for entering sheet-specific or printing machine-specific current parameters; 4.3 with a CPU that determines the optimal characteristics with regard to the current characteristic data and feeds the relevant parameters to a setpoint generator.

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