EP0949075B1 - Printing machine and method of operating a printing machine - Google Patents

Description

The invention relates to a method for operating a printing press, which a Inking unit with one between an ink fountain roller and an inking unit roller occasional contact with these rollers reciprocating lifter roller according to the preamble of claim 1 and a printing press with an inking unit, which one between an ink fountain roller and an inking roller with temporary Contact to these rollers reciprocating jack roller includes, especially to Implementation of the method according to the preamble of claim 9.

In sheet-fed offset printing presses, the ink to be printed is supplied via Lifter inking units, one with an ink fountain and a metering device have interacting ink fountain roller. By the metering device on Ink fountain, the ink layer thickness can be adjusted on the ink fountain roller. A Lifter roller takes a streak of color through occasional contact with the ink fountain roller certain length from the ink fountain roller and passes this amount of ink to one subsequent contact with an inking roller on this inking roller. By further inking unit rollers following this inking unit roller are split several times the amount of ink supplied by the squeegee roller and by inking rollers appropriate inking of the printing areas on a printing form cylinder located printing form. To those conveyed from the ink fountain into the inking unit To influence the amount of color, the metering device can be adjusted so that the Ink layer thickness changed on the ink fountain roller. The color layer thickness on the Ink fountain roller may, however, a certain minimum value, which is safe reproducibly set, do not fall below.

DE-OS 27 20 371 is a device for driving a ductor for inking units described in printing presses in which the amount of ink is changed by the Phase position of the movements of the lifter roller and the ink fountain roller over one Adjustment of the position of the drive and driven member of a non-uniform transmission is carried out to each other, so that the timing of the switching step Ink fountain roller of the lifter roller on the ink fountain roller changed. Should be the amount of paint can be reduced, so the area of the ink fountain roller comes to a standstill in moved the area of the system of the lifting roller on the ink fountain roller. in the In extreme cases, the system of the jack roller on the ink fountain roller in the time of Standstill of the ink fountain roller take place, so that the amount of ink adopted is practical is zero.

With this device, the amount of ink conveyed into the inking unit can be reduced are, however, the method on which the device is based is exclusively for Devices with a discontinuously driven ink fountain roller can be used. The DE-OS 27 20 371 device for performing the method is also very expensive to construct.

DE 44 06 727 C2 describes a method for controlling the fluid supply in the Production of printed products described, in which after entering a Changes in the speed of the printing machine commands before execution of the Speed change the supply rate of the fluid after a predetermined time function changed and after a preselected number of machine revolutions the Speed change of the main drive is initiated. This can be done by initiating the speed change of a color ductor before the speed change becomes. The movement characteristic of the color ductor is always maintained.

With this method, it is possible to change the color of the substrate Avoid changing the print speed, but not a reliably reproducible one achieve minimal feed rate.

The invention has for its object a method for operating a To create printing press by which a safely reproducible minimum Ink supply is guaranteed in an inking unit and which also with inking units with a continuously driven ink fountain roller can be used. Furthermore, the Invention, the object of a printing press, in particular for implementation to create the process, which is easy to operate and structurally inexpensive is trained.

According to the invention, the object is achieved by a method with the features of Claim 1 and solved by a printing press with the features of claim 9. Further features are contained in the subclaims.

The method for operating a printing press, which is an inking unit between a Ink fountain roller and an inking roller with occasional contact with these rollers includes reciprocating lifter roller, is characterized in that the Inking unit optionally in a normal operating mode and at least one color-reduced operating mode is operated, the ink fountain roller in Color-reduced operating mode with a different from the normal operating mode Movement characteristic rotates, and that the ink fountain roller in the at least one color-reduced operating mode rotates so unevenly that the oscillating Lifter roller comes into contact with the ink fountain roller at least once when the Ink fountain roller rotates at a first speed, and at least once with the Ink fountain roller comes into contact when the ink fountain roller with a second Speed rotates, the second speed being less than the first Speed is.

The periodically repeating lifter cycle described above is naturally at a constant machine speed (Printing speed) operated printing machine related. Among the different Ink fountain roller speeds within an operating mode will not possible from a speed compensation of the ink fountain roller speed speed differences resulting from the press speed Roger that. Rather, the lifter roller attaches itself to the ink fountain roller for the first time, when the ink fountain roller rotates at a slower speed and settles the lifter roller to the ink fountain roller a second time when the Ink fountain roller rotates at a higher speed, the printing press maintains a constant speed. The second application of the lifting roller to the Ink fountain roller can immediately follow the first application, d. that is, the Lift roller after the first application to the ink fountain roller towards the inking roller and swings back to the ink fountain roller and then attaches to the ink fountain roller, when it rotates at a different speed, this process changing periodically repeated, so that the lifting roller alternates with the faster and slower rotating ink fountain roller. But it can also be provided that the Lifter roller several times in succession to the slowly rotating ink fountain roller and then several times in succession to the faster rotating one Ink fountain roller creates. For example, the lifter roller contacts the ink fountain roller twice in a row, if it turns slowly, then twice in a row, if it turns faster, then twice in a row if it turns slowly, etc. In this way, many and many can Operating conditions optimally corresponding movement characteristics of the Ink fountain roller can be realized in the color-reduced operating modes.

The invention relates to one of the prior art (DE-OS 27 20 371) Teaching opposite direction. In the aforementioned prior art taught that an exact setting of the color metering is very complicated because at different ink fountain roller rotation speeds and the associated different hydrodynamic pressure a different color knife deformation occurs. The cause of the deficiency is seen in the fact that a change in dosage always is associated with a change in the characteristics of the ink fountain roller movement and thus the entire dynamic behavior of the device changes.

The invention is based on the surprising finding that Color knife deformation due to different hydrodynamic pressure Ink tanks with a modern metering device does not play an important role. Furthermore, it was recognized according to the invention that a change in the Characteristic of the ink fountain movement a structurally particularly complex construction the printing press can be realized. The optional operation of the inking unit in one normal operating mode and at least one color-reduced operating mode enables a very comfortable operation of the printing machine and a particularly rapid adjustment of the amount of ink conveyed into the inking unit when the ink changes Pressure and / or operating conditions. Depending on that for a printing process required amount of ink rotates the ink fountain roller in the inventive Procedure optionally according to a first law of motion in normal operating mode and according to at least one second law of motion in at least one color-reduced operating mode.

For example, the ink fountain roller can either be in normal operating mode continuously and in the color-reduced operating mode discontinuously or in normal Discontinuous operating mode and continuous in the color-reduced operating mode rotate.

In one embodiment of the method according to the invention, it is preferred provided that the ink fountain roller rotates continuously in the normal operating mode. This embodiment enables the ink fountain roller by a inexpensive drive, for example an electric motor, can be driven. Preferably the ink fountain roller is controlled by a separate, controllable electric drive driven. The ink fountain roller can also be from one of the printing unit drive derived mechanical drive are driven. The ink fountain roller can normal operating mode but also be operated discontinuously and for example rotate gradually. Preferably, the speed of rotation is continuously rotating Ink fountain roller coupled with the machine speed (printing speed). In the case of a step-by-step drive, the speed and the step frequency can also be used be coupled to the machine speed.

Another embodiment is characterized in that the ink fountain roller in color-reduced operating mode non-uniform, especially discontinuous, rotates. There is an irregular rotation of the ink fountain roller when the Ink fountain roller at constant machine speed (printing speed) is accelerated or decelerated. The discontinuous rotary movement of the Ink fountain roller is a preferred special case of the non-uniform rotary movement. The Ink fountain roller performs an intermittent in the color-reduced operating mode Rotating movement with temporary standstill. In this way, the in the inking unit the amount of ink conveyed can be reliably reduced reproducibly. This is not a complex process mechanical gear required. In the case of an electric motor driven ink fountain roller, the electric motor can be periodically accelerated and be delayed or stopped intermittently.

Another embodiment of the method is characterized in that the Inking unit is optionally operated in one of several color-reduced operating modes, the color-reduced operating modes with respect to the degree of color reduction are different from each other. By grading the color-reduced operating modes can be the optimal under different operating and / or pressure conditions Color-reduced operating mode can be selected. Choosing the optimal operating mode in Depending on the amount of color required for a printing process, such take place so that the inking unit with the lowest possible for trouble-free operation permissible amount of paint is operated. Switching or switching from normal to the at least one color-reduced operating mode can be dependent on one Machine speed reduction and from a color-reduced operating mode in the normal operating mode depending on an increase in machine speed respectively. The same applies to switching or switching between several color-reduced operating modes. The changeover or switching is preferably carried out automated.

This is a further embodiment of the method according to the invention characterized in that the second speed has the value zero and the The ink fountain roller stops when the lifting roller hits it. This one too preferred special case of the invention, the intervals of the repeat Ink fountain roller rotation periodically. In this way it can be used in the inking unit Reduce the amount of ink delivered to an extremely small amount. Thus, at one of the Ink fountain roller assigned and the printing ink across the printing width differently dosing color metering device also the zone openings lowest color requirements are kept open by the printing process and will be a Possibility created the metering elements of the color metering device again To be able to correct "plus" and "minus" so that the one set transversely to the printing direction Color profile effectively corrected by the printing process even with minimal ink consumption can be.

This is a further embodiment of the method according to the invention characterized in that the choice of operating modes by an electronic Control device takes place. The electronic control device can be a microprocessor included and be programmable so that the choice of operating modes and Switching the inking unit into the optimal operating mode is done automatically. Thereby the monitoring and operation of the printing press is simplified. The electronic The control device then controls the according to a programmed control method described above and below, in particular in the exemplary embodiments Control processes in the implementation of the method according to the invention in the Printing machine according to the invention.

The printing press, in particular for performing the method, with a Inking unit, which has one between an ink fountain roller and an inking unit roller This includes occasional contact with this reciprocating siphon roller characterized in that the inking unit optionally in a normal operating mode and is designed to be operable in at least one color-reduced operating mode, the Ink fountain roller in the reduced-color operating mode with one of the Movement characteristics differ when operating in normal operating mode Movement characteristic rotates, and that the drive of the ink fountain roller Ink fountain roller in the at least one color-reduced operating mode rotates non-uniformly, so that the vibrating lifting roller at least once with the Ink fountain roller comes into contact when the ink fountain roller with a first Speed rotates and comes into contact with the ink fountain roller at least once comes when the ink fountain roller at a second speed or speed rotates, the second speed or speed less than the first Speed or speed is.

This is an embodiment of the printing press according to the invention characterized in that the ink fountain roller from a main drive of the Printing machine mechanically separated drive is driven. Preferably the Ink fountain roller driven by a controllable separate drive. The drive of the Ink fountain roller can, for example, be electronically coupled to the printing press, so that the ink fountain roller depending on the press speed is drivable. A separate drive of the ink fountain roller makes one particularly possible uncomplicated construction of the printing press. But it can also be a gearbox with the ink fountain roller drive connected to the main drive of the printing press be provided. Such a transmission can be adjustable or switchable in this way that the inking unit can optionally be operated in the operating modes.

Another embodiment of the printing press is characterized in that the Drive of the ink fountain roller rotates continuously in normal operating mode.

Another embodiment of the printing press is characterized in that the Drive of the ink fountain roller non-uniform in the reduced-color operating mode, especially discontinuously, rotates.

Another embodiment of the printing press is characterized in that the Inking unit can optionally be operated in one of several color-reduced operating modes is formed, the color-reduced operating modes with respect to the extent of Color reduction are different from each other.

Another embodiment of the printing press is characterized in that the second speed is zero and the ink fountain roller stops when the Lifter roller strikes this. This design is a special case of Invention.

Another embodiment of the printing press is characterized in that this includes an electronic control device which the optimal operating mode selects and the press switches to this operating mode or switches. To this A particularly reliable change of the operating modes depending on achieved the current operating requirements of the printing press, especially with itself rapidly changing operating conditions.

The printing press is preferably a rotary printing press, for example a Sheet-fed rotary printing machine, trained. The printing press can be in direct or indirect flat printing processes or in letterpress processes. For example The printing press can be designed as a sheetfed offset printing press. The The aforementioned types of printing press are used to carry out the The method according to the invention is particularly suitable.

The invention is more preferred below with reference to the drawings Embodiments described.

Fig. 1

eine Druckmaschine,

Fig. 2

ein Farbwerk der Druckmaschine,

Fig. 3

eine Farbkastenwalze und eine Farbdosiereinrichtung des Farbwerkes,

Fig. 4

ein Programmablaufdiagramm zur Steuerung der Druckmaschine und des Farbwerkes und

Fig. 5

ein die Bewegungscharakteristik einer Heberwalze und verschiedene Bewegungscharakteristiken der Farbkastenwalze des Farbwerkes zeigendes Diagramm.

In the drawings shows

Fig. 1

a printing press,

Fig. 2

an inking unit of the printing press,

Fig. 3

an ink fountain roller and an ink metering device of the inking unit,

Fig. 4

a program flow diagram for controlling the printing press and the inking unit and

Fig. 5

a diagram showing the movement characteristic of a siphon roller and various movement characteristics of the ink fountain roller of the inking unit.

1 shows a printing press 1 according to the invention, which has at least one Printing unit 2 comprises. The printing press 1 is as one Sheet-fed offset rotary printing press. Each printing unit 2 comprises one Printing form cylinder 3, a blanket cylinder 4, an impression cylinder 5 and a Inking unit 6 for applying the printing ink to those on the printing form cylinder 3 located printing form. Furthermore, each printing unit 2 can be assigned to the inking unit 6 associated dampening unit 7 include. The printing press 1, each printing unit 2 and each inking unit 6 are by the electronic control device 8 with at least controlled by a microprocessor 9. The electronic control device 8 can Control panel 10 can be set and programmed.

Figure 2 shows a more detailed representation of the inking unit 6, which one Ink fountain 11 with an ink fountain roller 12 and the ink fountain 11 and Ink fountain roller 12 associated ink metering device 22 includes. The inking unit 6 includes in addition to the lifter roller 14 and the inking unit roller 15 further inking unit rollers for conveying and applying the printing ink. The ink fountain roller 15 is preferably as a friction roller formed which a lateral in the direction of its axis of rotation 21 Executes traversing movement. The jack roller 14 swings between the Ink fountain roller 12 and the inking roller 15 back and forth. The jack roller 14 can swing linearly back and forth between the rollers 12, 15. This is preferably done However, the lifting roller 14 swings by a pivoting movement. This is the Lifter roller 14 arranged on the pivoted lever 20 mounted in the frame 13. The pivot lever 20 is driven by the cam gear 19. The Cam gear 19 is driven by the drive 17. The drive 17 is preferably the main drive of the printing press 1, which also the printing unit 2 and drives the printing form cylinder 3. With the setting device 18 is the number of Vibrations of the lifter roller 14 from the ink fountain roller 12 to the inking roller 15 and back to the ink fountain roller 12 based on a certain number of Revolutions of the printing form cylinder 3 variably adjustable. The swinging movement of the Lifter roller 14 can also by a main drive of the printing press 1st independent drive, such as a pneumatic cylinder, take place Synchronization of the separate drive of the jack roller 14 to the main drive of the Printing machine 1 by means of an incremental encoder and the electronic control device 8 can be guaranteed. The jack roller 14 sets itself in a defined rhythm alternately to the ink fountain roller 12 and the first in the ink roller train Inking unit roller 15. If the ink fountain roller 12 during the investment period Lifter roller 14 rotates on the ink fountain roller 12 at a certain speed, passes the ink fountain roller 12 to the lifting roller 14 rolling on it Color strips, which of the siphon roller 14 during its investment in the Inking unit roller 15 is transferred to the latter and is conveyed into the inking unit 6. The length of the ink strip is from the contact time of the lifting roller 14 to the ink fountain roller 12 and the angle of rotation by which the ink fountain roller 12 during the installation of the Lifter roller 14 is rotated, depending. To influence the amount of paint transferred, can the ink layer thickness on the ink fountain roller 12 by means of Color metering device 22 and by changing the rotational speed of the Ink fountain roller 12 and the choice of the corresponding operating modes can be influenced. The rotation of the ink fountain roller 12 is driven by the drive 16. Preferably, the ink fountain roller 12 by one of the main drive Printing machine 1 driven independent separate drive 16, as shown in Fig. 2nd is shown. An incremental encoder can be used to synchronize a separate one Drive 16 to the main drive of the printing press, so that the Drive 16 when the printing press speed changes Ink fountain roller 12 of changes in printing press speed correspondingly faster or slower. The synchronization of the rotation of the Ink fountain roller 12 to the main drive 17 of the printing press can be directly proportional or according to another functional relationship (characteristic curve) and through the electronic control device 8 take place controlled. But it can also be provided that the rotation of the ink fountain roller 12 via a gear by the main drive 17 Printing machine 1 is driven. In this case, the gear can be adjusted in this way be designed so that the ink fountain roller 12 optionally depending on the setting of Gearboxes in different operating modes with different movement characteristics rotates. In this case, the synchronization of the phase relationship of the rotation is the Ink fountain roller 12 for rotation of the printing form cylinder 3 given in a simple manner.

In addition to controlling the rotation of the electronic control device 8 Ink fountain roller 12 and the printing form cylinder 3 and the vibration of the Lifter roller 14 also control the setting of the ink metering device 22. The The inking unit 6 shown is preferably designed such that the ink fountain roller 12 in a normal operating mode continuously and in at least one reduced color Operating mode rotates discontinuously. In the operating modes, i.e. both in normal as well as in the color-reduced operating mode, the rotation speed is the Ink fountain roller 12 preferably carried at the printing press speed. The movement of the jack roller 14 is also related to the press speed coupled and the lifting roller preferably vibrates continuously.

3 shows the ink fountain roller 12 and the ink metering device 22 assigned to it presented in more detail. The color metering device 22 comprises zone-wide Dosing elements 23-26, their training in DE 26 48 098 C3 (corresponding to US 4,242,958). The metering elements are 23-26 especially as the cylindrical and described in the cited patent Embodiment formed rotatable circumferential direction. such Dosing elements are also completely new in the book "Offsetdrucktechnik" 6 Edition 1989, Fachschriftenverlag GmbH and Co KG, ISBN 3-921217 on page 414 described and shown as well as of the "Speedmaster" printing press type of the company Heidelberger Druckmaschinen AG has been known for many years. Instead of a detailed one Description of the color metering device 22, the color metering elements 23-26 and one optionally existing film covering the color metering elements 23-26 therefore DE 26 48 098 C3 in its entirety in the description of the present Invention to be included. With such designed metering elements Changes in the movement characteristics of the ink fountain roller 12 no change the color film thickness due to different hydrodynamic forces of the color. The With regard to the above-mentioned document to be included, the Reworkability of the invention. At this point it should be emphasized that in connection with the invention also differently designed color metering devices are used, the color metering element or elements of sufficient stability have, so that these even with different movement characteristics of the Ink fountain roller or different ink fountain roller rotation speeds none subject to significant deformations. In Fig. 3 it is shown that the Dosing elements 23-26 at a different distance from the ink fountain roller 12 are adjustable. From the distance of the metering elements 23-26 to the ink fountain roller 12 Depending on the setting, there is a distance or a distance in the individual color zones Metering opening 27 between the respective metering element 23 and the peripheral surface the ink fountain roller 12. In a between the metering elements 23-26 and Ink fountain roller 12 inserted film (not shown) results in the metering opening 27 between the film and the ink fountain roller 12. Each metering device 27 by the rotation of the ink fountain roller 12 from the ink fountain 11 one of the zonal Setting appropriate amount of ink 35 promoted by the jack roller 14th can be removed. Each metering element 23-26 is in a negative Adjustment device 28 and a positive adjustment device 29 are designed to be adjustable. When adjusting in the positive setting direction 29, the distance between the Metering element 23-26 enlarged or the respective metering opening 27 opened so that more ink is conveyed through it. When moving to the negative Setting direction 28, the metering opening 27 is closed, so that less printing ink can pass through the respective metering opening 27. The dosing element 24 is located in a medium setting, so that this is in both setting directions 28, 29 is adjustable. The metering element 26 is set such that the associated one Dosing opening 27 is minimally opened or completely closed and an adjustment of the metering element 26 is only possible in the positive direction 29. The Metering element 23 is set such that the metering opening 27 is opened to a maximum and an adjustment of the metering element 23 is only possible in the negative direction 28 is. The adjustment of the metering elements 23-26 designed as an eccentric takes place by rotation about its axis of rotation. In order from the ink fountain roller 12 from the Ink fountain 11 per unit of time or per amount of printing ink conveyed influence, the color metering elements 23-26 adjusted and the Rotation speed of the ink fountain roller 12 can be changed, both the Ink layer thickness on the ink fountain roller 12 and the rotational speed of the Ink fountain roller 12 in practice certain minimum values that are reliably reproducible, do not fall below.

In Fig. 4, a flow chart is shown, which shows a preferred sequence of the Method for operating the printing press 1 includes. The single ones Process steps are shown as program levels 30-34 of a program, according to which the electronic control device 8 in the preferred automatic Carrying out the method controls the printing press 1 and the inking unit 6. In the Program stage 30 operates the inking unit 6 in a first operating mode. This is for example the normal operating mode. The ink fountain roller 12 rotates also continuously and initially at constant machine speed constant speed. As the press speed decreases, it decreases the color requirement. The speed of the ink fountain roller 12 is functionally dependent on the Change in press speed, for example proportional to Press speed, to one of the reduced amount of ink required corresponding lower ink fountain roller speed changed. Before lowering the The ink fountain roller speed is calculated by the electronic control device 8 on the basis of characteristics, functions or value tables stored in their memory which Ink fountain roller speed to realize the required amount of ink with reduced Press speed is necessary. In the following program stage 31 the result of this calculation, namely the required ink fountain roller speed a minimum speed stored in the electronic control device 8 compared. If the ink fountain roller speed required is not less than that Minimum speed, i.e. is greater or equal, the program jumps to Program level 32 and if the required ink fountain roller speed is less than that Minimum speed is in program level 33. At this point in the program is the Control algorithm of at least one color-reduced operating mode or at least a corresponding ink fountain roller mode and preferably several stepped color-reduced operating modes or ink fountain roller operating modes, For example, the operating modes shown in Fig. 5c-g, which in the form of predetermined Subroutines can be programmed. With several operating modes is additional one that switches to the following operating mode when program level 33 is called inner counting loop programmed. In program level 33 you can choose between next possible operating mode or in the next possible ink fountain roller operating mode be switched. Was the printing press 1 before the program level 33 in the normal Operating mode, the color-reduced operating mode is in program stage 33 called. Was the printing press 1 before program stage 33 already in one Color-reduced operating mode is operated in program stage 33 The next possible color-reduced operating mode is called, in which the funded Color quantity compared to the previous color-reduced operating mode by one certain amount is reduced. Before the press in the program level 33 determining the color-reduced operating mode, a new comparison is made the required in the color-reduced operating mode determined Ink fountain roller speed with the minimum speed in program level 33. Also the ink fountain roller speed of the color-reduced operating mode called up first the program jumps again from program level 31 below the minimum speed in program stage 33, in which the next color-reduced operating mode is called which is even more color-reduced than the previous color-reduced Operating mode. For example, the color-reduced one called up first Operating mode the operating mode shown in Fig. 5c and the second Running through the loop 31, 33 called second color-reduced operating mode in Fig. 5d correspond to the operating mode shown. The program loop 31, 33 becomes like this often run through until the optimal ink fountain roller speed has been found, which is not less than the minimum speed. If this condition is met, it jumps Program thereafter from program level 31 to program level 32, in which the electronic control device 8 automatically according to programmed control strategies decides whether the required metering opening 27 (Fig. 3) in a medium, well adjustable range is set. The electronic control device 8 can Control of the settings of the color metering device 22 can be used so that the current setting values of the metering elements 23-26 of the electronic control device 8 available. The metering opening 27 is in the middle of the well meterable range if that Dosing element 23-26 both in the negative direction 28 and in the positive Direction 29 is adjustable. In essence, it is sufficient if the electronic Control device 8 checks whether all metering elements 23-26 are still in the negative Direction 28 can be corrected or adjusted. By the invention The procedure is therefore when the printing machine speed is reduced longer zonal metering openings 27 possible without the inking unit amount of ink conveyed must be increased. In this way, the color profile over the Corrected printing width even in this operating state of the printing press become. Furthermore, there is the possibility of reducing the minimum The amount of ink that is in the closed ink zones and minimum ink fountain speed Inking unit 6 is promoted when individual or all ink zones in the closed Position (Fig. 3, position 26) are made. The metering opening 27 is not in the in both setting directions 28, 29 or at least in the negative setting direction 28 adjustable range, the program jumps from program level 32 to Program level 33, in which the next possible color-reduced operating mode is called. Continuing from the example started above, this can be act the color-reduced operating mode shown in Fig. 5e. The loop 31, 32, 33 is run through until the condition corresponding to program level 32 is met is, so that the program jumps to program level 34 and the printing press 1 in operates an optimal operating mode in which the ink fountain roller 12 with a optimal ink fountain roller speed rotates and the metering orifices 27 Dosing elements 23-26 are in an optimally adjustable setting range. In the the program level 32 control of the setting of the Color metering device 22 and the decision to be made based thereon The operating mode can be changed instead of by the electronic control device 8 also done visually or manually by the printer operating the printing press 1. This results in a comparison of the required ink fountain speed with the minimum speed in program stage 31 that these speeds are exactly the same in terms of programming, instead of jumping into program level 32 jumping into the program level 33 can be provided. The procedure for the operation of the printing press or the control method is thus characterized in that switching from a first color-reduced operating mode with lower color reduction in a second color-reduced operating mode with stronger Color reduction takes place if one in the first color-reduced operating mode Minimum rotation speed or minimum speed of the ink fountain roller is undercut. The method is further characterized in that the Switch from normal operating mode to an optimal color-reduced one Operating mode of several color-reduced operating modes takes place, each of which optimal color-reduced operating mode pre-graded color-reduced operating mode the Speed is below the minimum. Furthermore, the process characterized in that the ink fountain roller 12, an ink fountain 11 and the Ink fountain roller 12 is assigned an adjustable metering device 22, the Ink fountain roller 12 corresponding to the setting of the metering device 22 a lot Promotes printing ink from the ink fountain 11, and that after switching into one Color-reduced operating mode in which the minimum rotation speed of the Ink fountain roller 12 is guaranteed, a check is made whether there is a subsequent Correction of the setting in both setting directions 28, 29 or at least in one of the Setting directions 28, 29 of the metering device 22 is possible. Furthermore, that is A method characterized in that if the control reveals that an end of the Setting range is reached, switching to one corresponding to the next level Color-reduced operating mode takes place in which the color reduction is stronger than in the color-reduced operating mode corresponding to the previous stage. Farther the method is characterized in that the choice of the optimal one Operating mode can be done by the operator. Furthermore, the process is thereby characterized that checking whether a correction to the setting of the Dosing device in both setting directions 28, 29 or at least in the Setting direction 28 is possible, can be done by the operator. Furthermore, that is Method characterized in that in a preferred embodiment the Check whether a correction of the setting of the metering device 22 in both or one Setting direction 28, 29 is possible, takes place automatically.

5 shows the characteristic of the movement of the lifting roller 14 in diagram a shown. The lifter roller 14 continuously swings between the ink fountain roller 12 and the inking roller 15 back and forth, the phase relationship of the lifting stroke to Phase position of the printing unit preferably by one of the main drive 17 (FIG. 2) Printing machine removed rotary movement of the cam plate of the lifting roller 14 driving cam mechanism 19 is realized. As a function of the angle of rotation or the number of machine rotations (abscissa) is the lifting movement (ordinate) applied, the phase 36 the application of the lifting roller 14 on the Inking unit roller 15, phase 37 the movement of the lifting roller 14 Ink fountain roller 12, the phase 38 the concern of the lifting roller 14 on the Ink fountain roller 12 and the phase 39 the movement of the lifting roller 14 from the Represent ink fountain roller 12 back to inking roller 15. The oscillation cycle 40 the lifter roller 14 from the inking roller 15 to the ink fountain roller 12 and back repeats itself periodically, with the lifter roller 14 oscillating continuously. in the Diagram b is the movement characteristic of the ink fountain roller 12 in normal Operating mode shown, with the ordinate axis in the diagrams b-g Speeds of the ink fountain roller 12 and the abscissa axis the number of Machine revolutions or the rotation angle ϕ represents. With the same Printing machine speed also rotates the ink fountain roller 12 at a constant rate Speed, the rotation 41 of the ink fountain roller 12 in normal Operating mode is continuous. Diagrams c-g are preferred Embodiments of the color-reduced operating modes are shown, with diagram b according to the diagram g the printing ink is reduced more or more Ink feed rate decreases. The color-reduced shown in diagrams c-g Operating modes are optionally called up in program stage 33 (FIG. 4) Program the loops 31, 33 or 31, 32, 33 worked through and for everyone Loop through the operating mode following the current operating mode starting at c calling towards g. But it can also be just one only operating mode or selected operating modes from the operating modes c-g be provided. The first color-reduced operating mode shown in diagram c is characterized in that the ink fountain roller 12 at a first impact of the Lifter roller 14 on the ink fountain roller 12 stands still, at least two of the first Impact immediately following and successive impacts rotates and in the case of a further impact immediately following the at least two impacts stands still again and immediately in the event of at least two further hits subsequent and successive impacts rotated again etc. This Movement characteristics are repeated periodically. If the jack roller 14 on the Ink fountain roller 12 strikes, the latter stands still, so that the lifting roller 14 does not roll off done on the ink fountain roller 12. In this way the Ink fountain roller an extremely short ink strip from the ink fountain roller 12 through the Lifting roller 14 removed, which theoretically is an axially parallel line corresponds and practically due to the deformation of the elastic lifter roller 14 and Tracking of the lifter roller 14, which is driven in rotation by the inking roller 15 can correspond to a ribbon extending in the axis-parallel direction. In the Diagrams c-g, the movement phases 42-45 of the ink fountain roller 12 are uniform denotes, with phase 42 an acceleration of the rotation from standstill a speed value dependent or set on the machine speed equivalent. During phase 43, the ink fountain roller 12 rotates with it Speed, which is constant at constant machine speed. Phase 44 indicates a delay in the rotation of the ink fountain roller to a standstill, the ink fountain roller 12 is stationary again during phase 45. A A summary of the diagrams a and c shows that the ink fountain roller 12 during a Lifting stroke, d. H. during a resting phase of the lifting roller 14 on the Ink fountain roller 12, stands still and rotates during several lifting cycles. The Rotation cycle 46 is repeated periodically. The second shown in diagram d Color-reduced operating mode is characterized in that the ink fountain roller 12 at a first impact of the lifter roller 14 on the ink fountain roller 12 stands still a single second impact immediately following the first impact rotates and at a third immediately following the second impact Impact stops again, etc. This process or the rotation cycle 47 is repeated periodically, so that the lifting roller 14 alternately to the standing Ink fountain roller and applied to the rotating ink fountain roller. In diagram e there is a shown third color-reduced operating mode, in which the ink fountain roller 12 at a first impact of the lifter roller 14 rotates on the ink fountain roller, at at least two immediately following the first impact and consecutive impacts and one or at least two impacts immediately following further impacts rotated again, etc. During a Lifting stroke or application of the lifting roller 14 to the ink fountain roller 12 rotates the latter and during several lifting cycles, the ink fountain roller 12 Rotation cycle 48 of the ink fountain roller 12 is repeated periodically. In the in the Diagrams f and g of the color-reduced operating modes shown rotate the Ink fountain roller 12 only when it is out of contact with the lifting roller 14. The one in The fourth color-reduced operating mode shown in diagram f is characterized in that that the ink fountain roller 12 at a first impact of the lifting roller 14 on the Ink fountain roller 12 stands still within one following the first impact Vibration phase of the lifter roller 14 to the inking roller 15 every now and then Ink fountain roller 12 rotates back and the first time it hits following second impacts is stopped again, etc. The lifting roller 14 just puts on the stationary ink fountain roller 12. When the lifter roller 14 is not in contact, it rotates the ink fountain roller a little further in the meantime. The rotation cycle 49 repeats itself periodically. It can also be seen that the size of the step Color reduction of the color-reduced operating modes to one another by changing the Ink fountain roller speed effected or can be increased as shown. The Speed n2 (diagram f) is less than speed n1 (diagram e). Less fresh Color is achieved in that the ink fountain roller 12 between the Lifter roller system times slowly turn and little ink from the ink fountain 11 draws. No fresh paint at all can be achieved in that the ink fountain roller 12 also stands still between the lifter roller system times. In this way you can also Maintaining the sequence of the lifting movements Ink fountain roller rotation is a change in color reduction within different Reach operating modes. For example, the one in diagram e is dash-dotted variant shown with the speed n3 one compared to the fully illustrated Variant with the speed n1 represents more color-reduced operating mode. The measure of Color reduction can thus be achieved by changing the rhythm of the Ink fountain roller rotation and / or the size of the speed can be varied. In diagram g, a fifth color-reduced operating mode is shown, which thereby is characterized in that the jack roller 14 several times in succession on the Ink fountain roller 12 strikes when it is stationary. This makes the fifth operating mode characterizes that the ink fountain roller 12 within a first oscillation phase of the Lifter roller 14 to the inking roller 15 every now and then back to the ink fountain roller 12 rotates, in at least two immediately following the first oscillation phase and successive impingement of the lifter roller 14 on the ink fountain roller 12 stands still and within a second immediately following the at least two hits Vibration phase of the lifter roller 14 to the inking roller 15 every now and then Ink fountain roller rotates back, etc. The ink fountain roller 12 does not rotate after each Lifter stroke or application of the lifter roller 14 to the ink fountain roller a little further, but only after several lifters. The rotation cycle 50 repeats periodically. The ink fountain roller 12 rotates according to the c-g in the diagrams movement characteristics shown discontinuously or intermittently. The Deviation of the movement characteristics of each color-reduced operating mode to the in Diagram b shown normal operating mode is that the Ink fountain roller 12 in the normal operating mode continuously and in the color-reduced operating modes rotated discontinuously.

LIST OF REFERENCE NUMBERS

1

press

2

printing unit

3

Plate cylinder

4

Blanket cylinder

5

Impression cylinder

6

inking

7

dampening

8th

control device

9

microprocessor

10

control panel

11

paintbox

12

Ink fountain roller

13

frame

14

vibrator roller

15

Inking roller

16, 17

drive

18

adjustment

19

cam gear

20

pivoting lever

21

axis

22

ink metering

23-26

metering

27

metering

28-29

Setting direction

30-34

program level

35

printing ink

36-39

Lifter roller position and movement

40

oscillation cycle

41-45

Ink fountain roller position and movement

46-50

rotation cycle

n, n1, n2, n2

Ink fountain roller speed

φ

Engine rotation angle

Claims (15)

1. Method for operating a printing press (1) which comprises an inking unit (6) having a vibrator roller oscillating between an ink fountain roller (12) and an inking unit roller (15) for temporarily contacting these rollers (12, 15),
   characterized in that the inking unit (6) is selectively operated in a normal operating mode and in at least one reduced-ink operating mode wherein, in the reduced-ink operating mode, the ink fountain roller (12) rotates with a movement characteristic different from the movement characteristic in the normal operating mode, and that, in the reduced-ink operating mode, the ink fountain roller (12) rotates non-uniformly, such that the oscillating vibrator roller (14) contacts the ink fountain roller (12) at least once when the ink fountain roller (12) rotates at a first speed, and contacts the ink fountain roller (12) at least once when the ink fountain roller rotates at a second speed, the second speed being lower than the first speed.
2. Method according to claim 1,
   characterized in that in the normal operating mode the ink fountain roller (12) rotates continuously.
3. Method according to claim 1 or 2,
   characterized in that in the at least one reduced-ink operating mode the ink fountain roller (12) rotates non-uniformly, in particular discontinuously.
4. Method according to one of claims 1 to 3,
   characterized in that the inking unit (6) is selectively operated in one of several reduced-ink operating modes, which differ from each other in terms of the extent of the reduction of ink.
5. Method according to one of claims 1 to 4,
   characterized in that the second speed has a zero value and that the rotation of the ink fountain roller (12) is stopped when the vibrator roller (14) gets into contact: with the ink fountain roller (12).
6. Method according to one of claims 1 to 5,
   characterized in that a changeover from the normal operating mode to the at least one reduced-ink operating mode is performed when, in the normal operating mode, the rotational speed or the RPM of the ink fountain roller (12) is below a minimum value.
7. Method according to one of claims 1 to 6,
   characterized in that the operating modes are selected automatically by an electronic control device (8), in particular by a programmable electronic control device having a microprocessor (9).
8. Method for controlling the implementation of the operating method according to one of claims 1 to 7,
   characterized in that the selection of the operating modes and the changeover of the inking unit (6) to the respective optimum operating mode is performed under programme control by means of an electronic control device (8).
9. Printing press (1), in particular for implementing the method according to one of claims 1 to 8, having an inking unit (6) comprising a vibrator roller (14) oscillating between an ink fountain roller (12) and an inking unit roller (15) for temporarily contacting these rollers (12, 15),
   characterized in that the inking unit (6) is embodied to be selectively operable in a normal operating mode and in at least one reduced-ink operating mode, wherein, in the at least one reduced-ink operating mode, the ink fountain roller (12) rotates with a movement characteristic different from the movement characteristic in the normal operating mode, and that, in the reduced-ink operating mode, the drive (16) non-uniformly rotates the ink fountain roller (12) such that the oscillating vibrator roller (14) contacts the ink fountain roller (12) at least once when the ink fountain roller (12) rotates at a first speed, and contacts the ink fountain roller (12) at least once when the ink fountain roller rotates at a second speed, the second speed being lower than the first speed.
10. Printing press according to claim 9,
    characterized in that the ink fountain roller (12) is driven by a drive (16) separate from a main drive (17) of the printing press, in particular by a separate electric motor.
11. Printing press according to claim 10,
    characterized in that in the normal operating mode, the drive (16) drives the ink fountain roller (12) for continuous rotation.
12. Printing press according to claims 10 or 11,
    characterized in that in the reduced-ink operating mode, the drive (16) drives the ink fountain roller (12) for non-uniform, in particular discontinuous, rotation.
13. Printing press according to one of claims 9 to 12,
    characterized in that the inking unit (6) is embodied to be operable in one of several reduced-ink operating modes which differ from each other in terms of the extent of the reduction of ink.
14. Printing press according to one of claims 9 to 13,
    characterized in that the second speed has a zero value and that the rotation of the ink fountain roller (12) is stopped when the vibrator roller (14) gets into contact with the ink fountain roller (12).
15. Printing press according to one of claims 9 to 14,
    characterized in that it comprises an electronic control unit (8) which, in particular as a function of the current operating conditions in the printing press (1), selects the optimum operating mode and switches the printing press (1) over to said operating mode.

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