EP0901903A2 - Device for applying damping solution onto a cylinder of a rotary printing press - Google Patents

Abstract

Nozzles (6) are positioned along the length of the cylinders (2,5) of the machine, producing jets which are deflected and atomized by plates (9), nozzles and plates being located in a housing (13) which is open to the cylinder. At least one adjusting member is provided to maximum metering of moisturizing medium on the delivery side. Preferably the angle of the deflector plates can be adjusted by pivoting.

Description

The invention relates to a device for applying dampening solution to the Cylinder of a rotary printing press according to the preamble of Claim 1.

DE 29 31 579 C2 shows a device in which a Dampening unit of a rotary printing machine dampening solution by means of nozzles is applied. The nozzles are arranged along the cylinder. To the Dose the amount of water that escapes according to the machine speed To be able to, the width of the printing form is adjustable in its opening Aperture inserted. The disadvantage, however, is that they are arranged side by side The effect of nozzles overlap, which leads to fluctuations in the quality of the Print image leads. In addition, the drops generated are relatively large and form as so-called despite splitting and rubbing in the dampening system Watermarks visible in the print image. The result is a loss of quality and Waste.

JP 4-250 039 A shows a dampening device for a Rotary printing press in which pressurized in a box Fountain solution is sprayed onto a body by means of nozzles. The resulting one Moisture mist is blown through by compressed air blown into the box Slits pressed into a box wall and on the cylinder of a dampening system blown. The requirement of compressed air and its control make it Device and its operation is expensive. In addition, the causes Compressed air operation the emergence of the partially harmful Dampening solution mist in the area.

DE-PS 571 854 generates by means of a costly with compressed air operating suction nozzle a liquid jet, which on a baffle plate and a reflector is broken several times. The resulting fog then reaches an uncontrolled and unreliable plate cylinder to be dampened.

It is also common to use nozzles from a spray dampening system for metering dampening solution to be used in pulse mode (EP 0 325 381 B1). Despite good rubbing one such discontinuous application in a multi-roll dampening system there is a risk that the printing form inked unevenly and the Print quality is adversely affected. In addition, there are Pulse controls are expensive.

It is an object of the invention to use an inexpensive dampening solution device to be applied to a cylinder in the form of small droplets.

According to the invention, the object is achieved with a generic device solved the features of the characterizing part of claim 1. The The device produces very small droplets as they exit the nozzles Primary drops on impact with the impact plates cause secondary decay be subjected. The resulting droplets are one or two Powers of ten smaller than the primary drops Depending on the quality requirements, the droplet size allows the number of rollers or Cylinders of a dampening system to reduce or without such rollers with the device the dampening solution directly on the forme cylinder to apply. Practically, multiple squeezing of the droplets in one Dampening roller train no longer visible improvement. Furthermore, the Droplet discharge over the width of the device more uniform than in the known spray dampening systems. The reason for this is that, on the one hand much smaller droplets are generated and secondly in the possible ones Overlap areas of the spray effects of the nozzles on the baffle plates Fewer droplets are generated due to a higher film thickness of dampening solution the baffle reduces atomization activities. Also through the smaller droplet size less fountain solution accumulated in the ink. Overall, prerequisites for improving print quality and Reduction of paper waste created.

The device is thanks to its technically simple structure and small Control effort can be created inexpensively and without the requirement of Compressed air can be operated economically. The continuous operation of the nozzles ensures an even application of the dampening solution on a cylinder and ultimately on a forme cylinder with a corresponding positive influence on the print quality.

Further advantages and features emerge from the subclaims in Link with the description.

Fig. 1:

eine Vorrichtung zum Auftragen von Feuchtmittel im Querschnitt (Schnitt I-I gemäß Fig. 2)

Fig. 2:

die Draufsicht der Vorrichtung gemäß Fig. 1

Fig. 3:

eine weitere Variante zur u. a. in Fig. 2 gezeigten Randfeuchtung

Fig. 4:

die Ansicht IV nach Fig. 3

Fig. 5:

eine weitere Variante zu Fig. 3 (erhöhte Randfeuchtung)

Fig. 6:

eine weitere Variante zu Figur 1,

Fig. 7:

eine weitere Variante zu Figur 1,

Fig. 8:

die Ansicht VIII nach Figur 7.

The invention will be explained in more detail below using a few exemplary embodiments. The accompanying drawings show schematically:

Fig. 1:

a device for applying dampening solution in cross section (section II of FIG. 2)

Fig. 2:

the top view of the device of FIG. 1st

Fig. 3:

a further variant of the edge dampening shown in FIG. 2, among others

Fig. 4:

the view IV of FIG. 3rd

Fig. 5:

a further variant of FIG. 3 (increased edge dampening)

Fig. 6:

another variant of Figure 1,

Fig. 7:

another variant of Figure 1,

Fig. 8:

view VIII according to FIG. 7.

Figure 1 shows a device for applying dampening solution, arranged a cylinder of a dampening unit 1 of a rotary printing press. in the In the present case, the device is employed on a distribution cylinder 2 to which followed by a transfer roller 3 and a dampening roller 4, wherein the latter contacted the forme cylinder 5. Depending on the circumstances, the Moisture removal of the distribution cylinder 2 also on the transfer roller 3 or omitting the distribution cylinder 2 and the transfer roller 3 on the Moist application roller 4 may be arranged. The dampening unit 1 can also have a different structure.

The device contains 2 nozzles 6 to 8 along the distribution cylinder to be dampened (Fig. 2). The nozzles 6 to 8 are preferably designed as flat jet nozzles, to ensure a good distribution of the dampening solution to be applied in the axial direction of the To reach distribution cylinder 2. Such nozzles are commercially available. in the Radiation range of the nozzles 6 to 8, that is between them and the distribution cylinder 2, 2 baffle plates 9 to 12 are arranged along the distribution cylinder. The nozzles 6 to 8 and the baffles 9 to 12 are aligned so that the rays of the Nozzles 6 to 8 deflected from the baffles 9 to 12 onto the distribution cylinder 2 become. The nozzles 6 to 8 and the baffle plates 9 to 12 are in one for Distribution cylinder 2 housed open housing 13. The nozzles 6 to 8 are at Housing 13, the baffle plates 9 to 12 attached to an axis 15.

In the exemplary embodiment, per print page (the area of a print page is in 2 indicated with L) two nozzles 6 to 8 are provided. Each nozzle is 6 to 8 again assigned a baffle plate 9 to 12. It is also possible to do more or use fewer nozzles 6 to 8 per print page width and several Let nozzles 6 to 8 act on a baffle. It is also possible to have only one Flapper 9 to 12 to be provided per print page width.

The baffle plates 9 to 12 are pivotally arranged on the axis 15. To their Each baffle plate 9 to 12 is connected to a lever 16 by swivel adjustment which each attacks an actuator 17 (Fig. 1). As an actuator z. B. a Electric motor in connection with a spindle drive, a linear drive or a hydraulic working cylinders are used. On the control element 17th the output of a control unit 18 is guided.

The nozzles 6 to 8 are at a pressure p via a pipeline 19 Fountain solution supplied. There is one in each of the feed lines to the nozzles 6 to 8 Valve 20 to 22 interposed, the respective actuator 23 to 25 with is connected to the output of a control unit 26 (FIG. 2). For Simplification, the latter elements were not shown in FIG. 1, while in Fig. 2, the control elements for the baffle plates 9 to 12 are not shown are.

For the purpose of applying dampening solution to the distribution cylinder 2, this is under Pressure supplied to the nozzles 6 to 8. The fountain solution sprayed by the nozzles strikes the baffles 9 to 12, the generated by the nozzles 6 to 8 Primary drops are subjected to secondary decay. The generated one The dampening water mist reaches the distribution cylinder 2. The dosage of the on Distribution cylinder 2 applied amount of dampening solution is done by a Change the angle of attack α of the baffle plates 9 to 12 (position B). The flatter the baffles 9 to 12 are set for radiation of the nozzles 6 to 8, that is each the greater the angle α, the more dampening solution reaches the distribution cylinder 2. The angle adjustment of the baffle plates 9 to 12 takes place when the Control elements 17 by the control unit 18. The control unit 18 is on Control system of the printing press connected. In the shown Arrangement of the axis 15 outside the radiation range of the nozzles 6 to 8 can the baffles 9 to 12 completely from the radiation area of the nozzles 6 to 8 can be pivoted. In this position, marked with A, the baffle plates 9 to 12 there is a direct spraying of the distribution cylinder 2 and thus an extreme strong dampening solution application. You can use this position A to over-wet the Apply printing form, e.g. B. to remove the toning of a printing form, d. H. to let them run free. In position C, the dampening solution application is complete turned off, the nozzles 6 to 8 still fed with dampening solution can be. To support this shut-off position C work Baffles 9 to 12 advantageously together with a baffle 14. Besides, is the housing 13 is provided with a return 31 via which accumulates Dampening solution is returned. To support it, the housing is 13 advantageously arranged with a slight slope to the return 31. 1 is continue to thin the possibility of arranging an axis 15.1 in Radiation range of the nozzles 6 to 8 indicated. With such a Possibility of pivoting the baffle plates 9 to 12 about the axis 15.1 can not be swung out of the radiation area.

The pressure p of the nozzles 6 is by means of the valves 20 to 22 (pressure reducing valves) up to 8 dampening solution supplied and thus the dampening solution application corresponding control of the control elements 23 to 26 by means of the control unit 26 adjustable. It can also all be the width L of a printed page assigned nozzles 6, 7 are fed by a valve 20, or all of them the distribution cylinder 2 arranged nozzles 6 to 8 with the same, optionally variable pressure p operated and from a common Pipeline fed. The pressure setting can also be done individually by hand be made.

Fig. 2 also shows a way to increase the edge moisture of the Distribution cylinder 2. Such an increase in dampening solution application ultimately the forme cylinder can make it necessary for printing presses, e.g. B. because a possibly higher temperature of the edge areas of the forme cylinder, resulting from the warming of its bearings. The outermost baffle 9 extends to the edge of the distribution cylinder 2 only partially into the radiation area the associated nozzle 6. The other edge area of the distribution cylinder 2 with the further edge baffle was not shown. Part of the spray jet outer nozzle 6 strikes the distribution cylinder 2 directly, thereby increasing Dampening solution application is achieved. However, the droplets applied there larger, so that a loss of quality in the affected area can be expected is.

A further variant for increasing the edge moisture is shown in FIG. 3 and the following representations are used for similar recurring components For the sake of simplicity, the reference numbers used so far are used again. Likewise, the presentation and renewed explanation of some will again No use of upcoming assemblies. 3 closes to Edge of the distribution cylinder 2 to the outer baffle plate 27 at an angle the latter adjustable edge baffle plate 28. The edge baffle 28 can for example be screwed to the baffle plate 27 by means of a plate 29 be (shown as view IV in Fig. 4). Depending on the setting, any hits wide spray of the nozzle 6 on the edge baffle 28 with a corresponding increased concentration of dampening solution mist or the desired Increase in dampening solution application on the distribution cylinder 2. The inclination acts as a kind of beam focusing, it becomes the radiation in the edge area includes. The edge baffle 28 can also be used, for example, as an extended bent part of the baffle plate 27 be executed.

5 contain the two outer to increase the marginal moisture Baffle plates 32 in the area towards the edge of the distribution cylinder 2 to be dampened Breakthroughs 33 through which direct and therefore abundant dampening solution on the Distribution cylinder 2 can reach. In this case, before ordering the Dampening solution on the printing form can not be waived. The openings can be slots or holes, for example. As another Possibility or in addition to the variants mentioned can be increased of the dampening solution application on the edges also nozzles with higher Use volume flow.

Another variant of the metering of the dampening solution application is shown in Fig. 6. Here is at the same time, for example, the dampening device on a forme cylinder 5 placed. The baffle plates 9 can be pushed out of the radiation area of the nozzles 6 arranged. For this purpose, each baffle plate 9 is connected to an actuating element 30 that the input of the control unit 18 is guided. For the selection of the Actuating element 30 are again known variants, such as listed for example with regard to the control element 17. The further the Baffle plates 9 by appropriate control of the actuating elements 30 by means of the Control unit 26 pulled out of the radiation area of the nozzles 6 the more dampening solution is applied to the forme cylinder 5. However, there may be a loss of quality due to the increase in Order larger primary drops that do not disassemble on the baffle 9 were. It is advantageous by pulling the baffle plates 9 out of the Spray area of the nozzles 6 an over-moistening of the printing form, z. B. um to eliminate the toning of a printing form, d. H. to let them run free. On the other hand, by completely inserting the baffle plates 9 into the Spray area of the nozzles 6, advantageously up to an aperture 34, the Dampening solution application be switched off completely.

According to Figure 7 contains a device for applying dampening solution lengthways of a distribution cylinder 2 arranged baffle plates 35, each of the width L one Have printing side (printing plate width). The baffles 35 are in one Housing 13 of the device mounted shaft 36. The baffle plates 35 work together with nozzles 6, for example three nozzles 6 per Baffle plate 35 (ie per pressure side) are provided. The nozzles 6 are on one Ledge 37 attached, which is pivotally mounted on the housing 13. By The bar 37 is pivoted out of the housing 13 can be folded out (drawn in dashed lines), after which this and the interior of the Device (baffle plates, panels) for maintenance work are easily accessible.

In the area between the baffle plates 35 and the distribution cylinder 2 there are apertures 38 arranged to 40. They are pivotable on one fastened in the housing 13 Axis 41 mounted. Each panel has 38 to 40 for swivel adjustment an actuator 42. As an actuator 42 may, for. B. an electric motor in Connection with a spindle drive, a linear drive or a hydraulic Working cylinders are used. In the exemplary embodiment, this is actuator 42 driving in a straight line via a coupling 43 with the aperture 41 connected. The output of a control unit 44 is on the actuating element 42 guided. The dampening solution is applied by adjusting the diaphragms 38 to 40 the distribution cylinder 2 can be metered separately for each pressure side. With an arrangement of several apertures per print page (area L) is correspondingly narrower Areas can be dosed. For the purpose of adjusting the aperture 38 to 40 that is Control element 42 controlled by the control unit 4. This is done manually or as part of the machine control, the control unit 44 with the Control system of the printing press is connected. Depending on the adjustment of the orifices 38 to 40 is that of the baffles 35 leaving the nozzles 6 deflected spray onto a to be passed on the distribution cylinder 2 Share limited. According to FIG. 7, the diaphragms 38 to 40 work with one Partition 45 of the housing together and can the dampening solution in completely interrupt the position shown in dashed lines. But it can also other screens are used, for example Apertures made of partial apertures that can be moved towards and away from each other consist. A diaphragm can also be moved in a straight line. Such Aperture 34 is shown in FIG. 6.

The baffle plates 35 are inclined at a selectable angle β Set the spray direction of the nozzles and by means of a clamping screw 46 noticeable. With this setting, a preselection regarding the amount of dampening solution to be applied.

The dampening solution setting options described are also combined applicable. For example, to adjust the diaphragms 38 to 40 according to FIG. 7 in addition, a motorized adjustment of the diaphragms 35 may be provided, e.g. B., as shown in Figure 1. In addition, the pressure of the nozzle 6 supplied dampening solution can be adjusted.

FIG. 8 shows an advantageous possibility for over-moistening the edges. It is in each case the outermost diaphragm 40 towards the edge of the cylinder to be dampened placed less deep in the radiation area of the associated nozzles. For this purpose, the aperture 40 is inclined by the dimension a on the axis 41 screwed on. As a result of the inclination, the aperture 40 cuts to the edge less the spray jet and more dampening solution gets on the cylinder.

Figure 7 also shows a favorable seal of the housing 13. For this purpose the space containing the nozzles 6, the baffle plates 35 and the orifices 38 to 40 by means of arranged along the distribution cylinder 2 and slightly spaced apart from it Sealing strips 47, 48 limited. Two more parallel to the sealing strips 47, 48 Sealing strips 49, 50 act on the outlet remaining fine moisture mist opposite.

The area of the baffle plates 9 to 12, 27, 28, 32 acted upon by the nozzles advantageously just executed. Non-flat surfaces, e.g. B. convex or concave surfaces are used, whereby the corresponding curvatures transversely or in the longitudinal direction of the baffle plates 9 can extend to 12, 27, 28, 32. The areas to be acted upon are also included special surface roughness possible.

Claims (18)

Device for applying dampening solution to the cylinder (2, 5) Rotary printing machine with nozzles (6.) Arranged along the cylinder (2, 5) to 8), which are continuously fed with pressurized fountain solution be and their beam under deflection and atomization along the Cylinder (2, 5) arranged baffle plates (9 to 12, 35) on the cylinder (2, 5) is directed, the nozzles (6 to 8) and baffle plates (9 to 12, 35) in one housing (13) open to the cylinder (2, 5) are housed, as well as with at least one control element for a maximum print page width Dosing the dampening solution application. Apparatus according to claim 1, characterized in that the baffle plates (9 to 12) for dosing the dampening solution application can be adjusted in their position for the radiation of the nozzles. Device according to claim 2, characterized in that the baffle plates (9) can be pushed out of the radiation area of the nozzles (6). Apparatus according to claim 2, characterized in that the baffle plates (9 to 12) are pivotable, the pivot axis (15.1) being in the radiation area of the nozzles (6 to 8). Apparatus according to claim 2, characterized in that the baffle plates (9 to 12) are pivotable, the pivot axis (15) being outside the radiation range of the nozzles (6 to 8). Device according to one of claims 2 to 5, characterized in that, in order to increase the edge moisture, the two outer baffle plates (9) only partially extend towards the edge of the cylinder (2) into the radiation area of the respectively associated nozzle (6). Device according to one of claims 2 to 5, characterized in that in order to increase the edge moisture, an edge baffle plate (28), which is arranged at an angle to the latter, adjoins the two outer baffle plates (27) towards the edge of the cylinder (2). Device according to one of claims 2 to 5, characterized in that to increase the edge moisture the two outer baffle plates (32) have openings (33) in the area towards the edge of the cylinder (2). Device according to one of the preceding claims, characterized in that the nozzles (6 to 8) are designed as flat jet nozzles. Device according to one of the preceding claims, characterized in that the nozzles (6 to 8) for metering the dampening solution application can be fed with dampening solution which can be adjusted with regard to its pressure (p). Device according to one of the preceding claims, characterized in that diaphragms (38 to 40) delimiting the spray jet are arranged in the region between the baffle plates (35) and the cylinder (2). Apparatus according to claim 11, characterized in that the orifices (38 to 40) for metering the dampening solution application can be set more or less in the radiation area of the nozzles (6). Device according to claim 12, characterized in that the screens (34) can be pushed. Apparatus according to claim 12, characterized in that the screens (38 to 40) are pivotable. Device according to one of claims 12 to 14, characterized in that, in order to increase the edge moisture, the two outer screens (40) extend less deeply into the radiation area of the respectively associated nozzle (6) towards the edge of the cylinder (2). Device, in particular according to one of the preceding claims, characterized in that the nozzles (6), which improve their accessibility, are fastened to a bar (37) which is pivotably mounted on the housing (13) and when the nozzles (6) are pivoted out of the housing (13) are foldable. Device according to one of claims 1 to 16, characterized by the arrangement on a cylinder (2) of a dampening unit. Device according to one of claims 1 to 16, characterized by the arrangement on a forme cylinder (5).

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