EP2604431A2 - Intaglio printing machine with web tension compensation and method for servicing such an intaglio printing machine - Google Patents

Abstract

The printing unit (10) has guide rollers (5) for guiding the printing material (100). The guide rollers are arranged along upstream and downstream directions of an impression roller (2) respectively. A servomotor (7) associated with an actuator (8) is provided to drive the gravure cylinder (3) and the impression roller, for changing the height of the impression cylinder from operating position into maintenance position. The actuator control device is provided for balancing web tension of printing material. An independent claim is included for method for servicing rotogravure printing unit.

Description

The invention relates to a rotogravure printing unit with the preamble features of claim 1 and a method for servicing such a rotogravure printing unit having the features of claim 7.

State of the art

A commonly used configuration of a gravure printing unit is, for example, in the document DE 42 42 582 C2 shown. The lateral surface of a gravure printing cylinder, also referred to below simplified as a plate cylinder or printing cylinder, at least partially immersed in a filled with gravure ink pan, which is located below the gravure cylinder. Upon rotation of the gravure cylinder about its axis of symmetry, the wells passing through the well in the lateral surface are filled with gravure ink. Excess paint is stripped off by at least one squeegee against the jacket surface. In a printing gap located in the upper angle sector of the gravure printing cylinder, the gravure ink is transferred to a printing material, which is pressed by means of a counter-pressure cylinder, hereinafter also referred to as impression roller, on the colored outer surface of the gravure printing cylinder.

The DE 10 2004 009 492 B3 describes a gravure printing unit with a impression roller in which the impression roller can be set against a forme cylinder along a first travel path. If the impression roller is moved from its working position to a service point, the impression roller and the form cylinder are easily accessible and can be maintained, ie exchanged or cleaned. If the printing material web is not stopped during the lifting of the impression roller from the forme cylinder and the printing material are further printed or processed, for example, in a before or after arranged printing unit or processing station, so must during the lifting of the impression Web tension compensation done. So it is well known and for example in the textbook " Kipphan: Handbook of Print Media, 2000 "(page 288 ), for the web tension control so-called biasing or retraction works, which before the first printing unit, or so-called pull-out, which are arranged after the last printing unit to use. To regulate the web tension compensation when lifting the impression roller by the known devices for web tension compensation, however, is considered to be laborious, less precise and therefore disadvantageous.

task

The object of the present invention is therefore to provide a rotogravure printing unit and to describe a method for servicing such a rotogravure printing unit, wherein a register-accurate printing or processing of the printing material web is made possible even with raised impression roller in upstream and downstream printing units or processing stations and the disadvantages of At least reduced prior art.

This object is achieved by a rotogravure printing unit for a printing machine for printing a web-shaped substrate, wherein the rotogravure printing unit has a forme cylinder, an inking device, a impression roller and at least two guide rollers for guiding the printing material. The first guide roller is - seen in the web running direction - upstream and the second guide roller - as seen in the web running direction - arranged downstream of the impression.
According to the invention, the rotogravure printing unit has a servo drive assigned to the forme cylinder for driving the forme cylinder and an actuator assigned to the impression roller for changing the height of the impression roller from a working position to a clearly spaced and easily accessible maintenance position. The impression roller can also be assigned a servo drive for driving the impression roller. In particular, in the case of a thin and / or sensitive printing material, the impression roller can thus be actively driven and not only passes on passively. In addition, an actuatable device for web tension compensation is provided in the rotogravure printing unit itself in order to keep the web tension constant in this rotogravure printing unit. Through this Embodiment, it is possible in an advantageous manner, during the lifting of the impression from the forme cylinder directly in the rotogravure even perform a web tension compensation, so that the lifting of the impression has no effect on the web tension of the printing material in upstream or downstream stations.
In the maintenance position, cylinder maintenance is possible in a broader sense, ie cleaning, repair, changeover, replacement.

In an advantageous embodiment of the rotogravure printing unit according to the invention, the first and second guide rollers are arranged between the height level of the impression roller in its working position and the height level of the impression roller in its maintenance position. When the impression roller is raised from its working position to its maintenance position, the printing material web runs directly from the first to the second guide roller and is guided in each case along a partial circumference of a respective guide roller through this.

In a particularly advantageous and therefore preferred embodiment, the actuator assigned to the impression roller is designed as an electric motor, in particular as a servomotor, for displacing the impression roller along a guide, which is in particular vertically aligned. The design of the actuator as an electric motor allows for a very accurate routing and on the other hand, the feedback of each current IstPosition.

In an advantageous embodiment of the rotogravure printing unit according to the invention, the device for web tension compensation has a further guide roller and an electric motor for displacing the further guide roller along a guide. This guide can be oriented horizontally in particular.

In a particularly advantageous and therefore preferred variant of the rotogravure printing unit according to the invention, the axes of the further guide roller and the impression roller in its working position in operation of the rotogravure printing unit are arranged in a vertical plane. In other words: during operation of the rotogravure printing unit, the further guide roller is located vertically above the impression roller. The first guiding role, second guiding role, another idler roller and the impression roller as well as the forme cylinder are arranged mirror-symmetrically to a center plane through the form cylinder and impression roller, ie to the aforementioned vertical plane. This advantageously makes it possible for the rotogravure printing unit to be independent of the direction of travel. That is, the substrate web can be processed by the rotogravure printing unit in and through this after adjustment of the web run in both possible directions. This is particularly important if the substrate web is to be printed on both sides, ie in a first pass on the recto printing side and in a second pass in the reverse web direction from the counterpressure side.

The invention also relates to a narrow-web rotary printing press with a plurality of printing units, wherein at least one of the printing units is designed as described above. In addition, the narrow-web rotary printing press may have a known from the prior art retraction and extraction.

Furthermore, the invention relates to a method for servicing a rotogravure printing unit as described above, wherein the impression roller is lifted off the forme cylinder, so that both are accessible for maintenance. Becoming accessible in this context means that the machine operator can perform cleaning work on impression roller or forme cylinder, that impression roller or forme cylinder can be exchanged, that intaglio sleeves can be pushed onto the gravure cylinder, etc. During lifting of the impression roller by a displacement movement from its working position into its Maintenance position while a device for web tension compensation is controlled, such that the web tension is kept approximately constant and wherein the web-shaped substrate is not stopped. This advantageously makes it possible for upstream and downstream printing units or processing stations to continue working while the rotogravure printing unit is being maintained.

In an advantageous embodiment of the method according to the invention, namely when the impression roller, a controllable electric motor and the device for web tension compensation are also assigned a controllable electric motor are the electric motors driven by a common control unit, such that the elongation of the printing material is offset by the lifting of the impression of the device for web tension compensation at the same time. Corresponding control rules can be stored in the control unit.

The described invention and the described advantageous developments of the invention are also in any combination with each other advantageous developments of the invention.

With regard to further advantages and constructive and functional aspects of advantageous embodiments of the invention, reference is made to the dependent claims and the description of embodiments with reference to the accompanying drawings.

embodiment

Fig. 1a:

ein erfindungsgemäßes Tiefdruckwerk mit Presseur in Arbeitsstellung

Fig. 1b:

ein erfindungsgemäßes Tiefdruckwerk mit Presseur in Wartungsstellung

Fig. 2:

ein Tiefdruckwerk, bei dem ein Formzylinder mit größerem Durchmesser eingesetzt wird

Fig. 3:

ein Tiefdruckwerk mit umgekehrter Laufrichtung der Bedruckstoffbahn

Fig. 4:

die Einrichtung zum Bahnspannungsausgleich des Tiefdruckwerks in einer Detailansicht

The invention will be explained in more detail with reference to preferred embodiments. It show in a schematic representation

Fig. 1a:

an inventive intaglio printing unit with impression roller in working position

Fig. 1b:

an inventive intaglio printing unit with impression roller in maintenance position

Fig. 2:

a gravure printing unit, in which a form cylinder is used with a larger diameter

3:

a gravure printing unit with reverse direction of the printing material web

4:

the device for web tension compensation of the gravure printing plant in a detailed view

Corresponding elements and components are provided in the figures with the same reference numerals.

In Fig. 1a an inventive rotogravure printing unit 10 is shown, in which a printing substrate 100 is printed. The support structure of the printing unit 10 is formed by a printing unit stand 1. As shown by the arrow b, the passes through Substrate web 100 the rotogravure printing unit 10 thereby as follows: from a preceding printing unit not shown or a preceding processing station, the printing substrate 100 runs in the gravure printing unit 10, is passed through a first guide roller 5 between gravure cylinder 3 and impression roller 2, where the printing substrate 100th is printed, subsequently guided by a second guide roller 5 and then passed over the further guide roller 41 of the device for web tension compensation 4 before it leaves the gravure printing unit 10 and is transported to a downstream, not shown further printing unit or a downstream processing station, not shown. In the presentation of Fig. 1a the impression roller 2 is in its working position and at a height level HA, while the further guide roller 41 is in its zero position N. The further guide roller 41 and the impression roller 2 are arranged in a vertical plane VE.
The forme cylinder 3 is driven by a servomotor 7, which is not visible behind the plane of the drawing. In the figures, therefore, only the drive axis of the servomotor 7 is indicated. Also, the impression roller 2 may be associated with a servomotor to its drive (not shown).

If now the gravure printing unit 10 is to be serviced or converted for a subsequent order, the impression roller 2 is lifted off the gravure cylinder 3 along a vertical guide by an actuator 8. The impression roller 2 is thereby raised from its height level of the working position HA to its height level in the maintenance position HW. The raised state is in Fig. 1b As is apparent from the figure, at the same time during the lifting of the impression roller 2, the device for web tension compensation 4 was activated, namely, the further guide roller 41 was moved by a compensating movement a from its position in the vertical plane VE slightly to the right in a balancing position A. , That is, the shortening of the web path by lifting the impression roller 2 is compensated by the compensating movement a, which causes an elongation of the web running path, and the web tension is kept constant. The control of the pressurizer 2 associated actuator 8 and the further idler 41 associated electric motor 42 is performed by a common control unit 9. In this control unit 9 corresponding time-path curves for both the actuator 8 and for the electric motor 42 may be deposited.

By lifting the impression roller 2, it is possible for the machine operator to carry out maintenance and retooling work on the gravure printing unit 19. This was done according to the representations of Fig. 1b the squeegee of the inking device 6 turned off by the gravure cylinder 3, so that even the gravure cylinder 3 can be exchanged.

Fig. 2 shows the rotogravure printing unit 10 in operation. In contrast to the representation of Fig. 1a a gravure cylinder 3 is used with a larger diameter. The required web tension compensation, which is required due to the larger gravure cylinder 3, is realized by the device for web tension compensation 4. The further guide roller 41 has been moved from its zero position N by a compensating movement a in a balancing position A slightly to the right.

Fig. 3 shows the rotogravure printing unit 10 in operation. In contrast to the representation of Fig. 1a the direction of travel b of the substrate web 100 was reversed. This is easily possible due to the symmetrical arrangement of the rollers 4, 5 and the cylinder 2, 3 in the neutral position N.

In Fig. 4 the device for web tension compensation 4 is shown in detail: The further guide roller 41 can be moved along a horizontal guide 43 so that it causes a compensating movement a. The displacement of the further guide roller 41 is effected by an electric motor 42, the rotational movement of which is converted by a gear 44 with spindles into a linear movement and is transmitted to both bearings of the further guide roller 41.

LIST OF REFERENCE NUMBERS

1

Printing stand

2

impression roller

3

form cylinder

4

Device for web tension compensation (compensator)

5

sheave

6

Inking device

7

Servo drive forme cylinder

8th

Actuator impression roller

9

control unit

10

Rotogravure printing

41

another leading role

42

electric motor

43

guide

44

transmission

100

printing material

a

compensatory movement

b

Web direction

H

displacement movement

A

Compensation position idler

N

Zero position idler

HA

Height level working position

HW

Height level maintenance position

VE

Vertical level

Claims (8)

Rotary gravure printing unit (10) for a printing machine for printing a web-shaped printing material (100) with a forme cylinder (3), an inking device (6), a impression roller (2) and two guide rollers (5) for guiding the printing material (100), wherein the first Guide roller (5) - seen in the web running direction (b) - upstream and the second guide roller (5) - seen in the web running direction (b) -stream downstream of the impression roller (2) is arranged,
characterized,
in that the rotogravure printing unit (10) has a servo drive (7) associated with the forme cylinder (3) for driving the forme cylinder (3) and an actuator (8) associated with the impression roller (2) for changing the height (h) of the impression roller (2) from a working position has a maintenance position and that in the rotogravure printing unit (10) an actuatable controllable device for web tension compensation (4) is provided in order to keep the web tension in the rotogravure printing unit (10) constant. Rotary letterpress printing plant according to claim 1,
characterized,
in that the first and second guide rollers (5) are arranged between the height level (HA) of the impression roller (2) in its working position and the height level (HW) of the impression roller in its maintenance position. Rotary gravure printing unit according to one of the preceding claims,
characterized,
in that the actuator (8) assigned to the impression roller (2) is designed as an electric motor for displacing (h) the impression roller (2) along a guide, which is in particular vertically aligned. Rotary gravure printing unit according to one of the preceding claims,
characterized,
in that the device (4) for web tension compensation has a further guide roller (41) and an electric motor (42) for displacing (a) the further guide roller (41) along a guide (43), wherein the guide (43) is oriented in particular horizontally. Rotary letterpress printing plant according to claim 4,
characterized,
that the axes of the further guide roller (41) and the impression roller (2) in its working position during operation of the rotogravure printing unit (10) in a vertical plane (VE) are arranged. Narrow-web rotary printing press with a plurality of printing units,
characterized,
in that at least one of the printing units is designed as a rotogravure printing unit (10) according to one of the preceding claims. A process for servicing a rotogravure printing unit (10), in particular according to one of claims 1-5, wherein the impression roller (2) is lifted off the forme cylinder (3), so that both are accessible for maintenance and during the lifting of the impression roller (2). a device (4) for web tension compensation in the rotogravure printing unit (10) is driven by a displacement movement (h) from its working position to its maintenance position, such that the web tension is kept approximately constant and the web-shaped printing material (100) is not stopped. The method of claim 7 for servicing a rotogravure printing unit (10) according to claims 3 and 4, wherein the electric motors (8, 42) are controlled by a common control unit (9).

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