EP1519837A1

EP1519837A1 - Device for cleaning the surface of a rotating body driven in rotation

Info

Publication number: EP1519837A1
Application number: EP03762419A
Authority: EP
Inventors: Andreas Horst Dr.H.C. Stranz; Karl-Otto Neutzner
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-07-08
Filing date: 2003-06-26
Publication date: 2005-04-06
Anticipated expiration: 2023-06-26
Also published as: EP1519837B1; DE50303712D1; ATE328740T1; DE10230790B4; WO2004005029A1; AU2003254614A1; DE10230790A1

Abstract

The device comprises a round cylindrical ultrasound generator (5), adjustable relative to the rotating body with radial emission. The ultrasound generator (5) has a soft coating on the outer surface thereof which may be wetted with cleaning fluid (11.2). The above is driven in rotation about an axis (6) parallel to the axis (10) of the rotating body.

Description

Device for cleaning the surface of a rotating body driven in rotation

description

The invention relates to a device for cleaning the surface of a preferably circular cylindrical rotating body, in particular a roller or a cylinder of a printing press, driven in rotation about an axis.

Washing devices on offset printing machines are generally known and are used for cleaning inking rollers, blanket or impression cylinders. Systems are also known, the washing unit for the blanket cylinder being supplied with detergent and compressed air via a pump station. The core of this system is a washing unit with four main components, which consists of a clean cloth dispenser, a wiper, a pressure bar with an inflatable rubber lip and spray nozzles that ensure an even distribution of water and detergent. Using a microprocessor control, all blanket cylinders can be cleaned simultaneously or individually. The washing programs required for this can be individually selected for each printing unit, depending on the degree of soiling of the rubber blankets, via a central control unit. Depending on the washing program, a metered amount of detergent can be wound onto the washcloth with water through special nozzles.

A washing system for blanket cylinders of an offset printing machine is also known (G 91 15 948 U), which is equipped with a washing device which can be pressed onto the blanket cylinder during the washing process and to which a storage container for washing liquid is assigned. The washing liquid is fed to a return tank via a return line after consumption.

_F erner is known a washing device for blanket cylinders of offset printing presses with a housing which can be adjusted to the blanket cylinder by pivoting about a pivot axis (DE 40 10 957 C2), the washing device being assigned a washing roller which is associated with a A large number of spray nozzles lying next to one another in the axial direction is provided with a washing liquid for spray application. More solvent is used in this device.

In addition, a washing device for inking units in printing presses is known (DE 41 21 017 AI), the washing device being accommodated in a housing in which a speed-controllable driven rubber roller and a polygon roller which is driven in opposite directions and can be sprayed with nozzles and is operatively connected to the rubber roller are arranged are. The housing is adjustable against cleaning the roller. The ink residues are collected in a so-called squeegee container. Arranged under the polygon roller and inside the housing is a trough filled with cleaning agent, which is connected at its bottom to a vibration generator and into which the surface of the polygon roller is immersed. The vibration generator rests on vibration isolators which are connected to the bottom of the housing. The vibration generator works in the ultrasonic range and removes any color residues that may still be left on the polygon roller. The tub fills with cleaning agents and paint residues, which are fed in via the nozzle strips or via the polygon roller. The liquid in the tub then overflows and is returned to the cleaning circuit via the detergent discharge device.

In contrast, the invention has for its object to optimize a cleaning device of the type mentioned with few structural means and to improve overall.

The cleaning device that achieves this object has a circular-cylindrical ultrasonic generator with radial radiation that is adjustable with respect to the rotating body to be cleaned. The ultrasonic generator has on its outer jacket a soft coating that can be wetted with cleaning fluid. It can be driven to rotate about an axis parallel to the axis of the rotating body.

Due to the advantageous design and arrangement of the cleaning device, cleaning is significantly improved and also intensified compared to the known devices, it being possible to make do with few structural means. Furthermore, this device cleans more intensively and gently. This enables the cleaning tervalle enlarged and the service life of the components to be cleaned extended. In addition, solvents can be saved significantly in the cleaning liquid.

In a preferred embodiment, the ultrasound generator can be positioned on the rotating body and switched off. He can switch between a working position and a non-working position.

In a preferred embodiment, the ultrasound generator can be adjusted on its axis or along its axis, and preferably in a reciprocating actuating movement with a stroke of 1 mm to 50 mm and a stroke frequency of 100 s ^_1 to 10 min ^"1 The axial adjustment of the ultrasound generator serves to compare the cleaning effect, which is caused by the reactions in the cleaning liquid caused by the ultrasound.

In a preferred embodiment, the ultrasound generator moves in its radiation direction, in the longitudinal ultrasound wave direction or transversely to its axis, and preferably in a reciprocating actuating movement with an amplitude of 1 μ to 240 μ, preferably with a half amplitude of 10 μ to 100 μ. This movement of the ultrasound generator leads to an equalization and intensification of the ultrasound effect on the cleaning process. The frequency at which the movement is carried out corresponds to the selected ultrasound frequency. The movement is e.g. B. generated in welding sonotrodes by the piezoceramic disks or piezoceramic packages. In a preferred embodiment, there are also relative movements transverse to the radiation direction, in the transverse wave direction, or here along the axis of the ultrasound generator. These movements are carried out with a half amplitude of up to 5 μ. All movements of this type can be adjusted by changing parameters.

In a preferred embodiment, a cam mechanism or a swash plate mechanism or a linear drive is provided for the adjustment of the ultrasound generator or the ultrasound generator is accommodated in a holder which is pivotably mounted about an axis. In a preferred embodiment, the ultrasound generator is clocked in one or more of its movements and / or its ultrasound radiation.

In a preferred embodiment, the ultrasound generator can be pressed onto the rotating body.

In a preferred embodiment, the ultrasound generator is spring-loaded against the rotating body.

In a preferred embodiment, one or more nozzle (s) are / are provided for supplying cleaning fluid to the coating of the ultrasound generator. If there is only one nozzle, its outlet opening should extend approximately over the entire length of the rotating body and / or ultrasound generator. However, there are also several nozzles, preferably arranged in a row.

In a preferred embodiment, the coating of the ultrasound generator is designed as a casing of the same. The covering can also be a self-contained belt that runs over the ultrasound generator and at least one further roller.

In a preferred embodiment, a stripping element is provided which acts against the coating of the ultrasound generator. In the case of a band-shaped covering, it is advisable to arrange the stripping element on the further roller.

In a preferred embodiment, the stripping element is rotatably mounted.

In a preferred embodiment, at least one nozzle for cleaning fluid is provided on both sides of the wiping element.

The coating of the ultrasonic generator can be brush-like and / or consist of foam and / or fabric. A mesh-like and / or mesh-gummed fabric that is bristled is preferred. A preferred material for the covering is terry cloth or molton. However, other materials that absorb cleaning fluid and that conduct ultrasound in the cleaning fluid can also be considered. In a preferred embodiment, a web of cleaning cloth runs over the ultrasonic generator, which comes from a clean cloth roll and is wound up into a dirty cloth roll.

In a preferred embodiment, the web can be wetted with cleaning liquid on the ultrasound generator side, in particular sprayed with one or more nozzle (s). Wetting "from the inside" prevents cleaning fluid from getting into the printing press.

In a preferred embodiment, the ultrasound generator is designed as an intensity-modulated and / or amplitude-modulated and / or frequency-modulated and / or pulsed ultrasound transmitter.

The ultrasound generated by the ultrasound transmitter is preferably in a frequency band between 2 x 10 ⁴ s ^"1 and 2 x 10 ⁶ s ^_1 or in a frequency band between 2 x 10 ⁴ s ^{" 1} and 10 ⁵ s ^{~ l} or in a frequency band between 4 x 10 ⁴ s ^"1 and 2 x 10 ⁵ s ^{" 1} .

In a preferred embodiment, the ultrasound generator, if necessary in connection with its casing, only effects a preliminary stage of cavitation. This is to be understood in such a way that cavitation bubbles can already form, but they do not reach their actual size required to implode themselves, and therefore do not implode, or do not implode early with such a great impact, but rather disintegrate. So no sonoluminescence can form.

In a preferred embodiment, a welding sonotrode is used as the ultrasound generator. The latter conventionally has a converter, an amplitude transformation piece and a radiating sonotrode head.

In a preferred embodiment, the ultrasound generator has piezoelectric transducers which are distributed with an axial offset over the circumference of the ultrasound generator. This measure serves to even out the effects of ultrasound.

In a preferred embodiment, the outer jacket of the ultrasound generator consists of a layer material, the surface hardness of which is less than the surface hardness of the base body. The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing. Show it:

Figure 1 is a partial side view of a device for cleaning blanket cylinders for an offset printing press with an adjustable ultrasonic generator.

FIG. 2 shows a schematic illustration of the blanket cylinder with the ultrasound generator arranged underneath in a front view transverse to FIG. 1;

3 shows a further exemplary embodiment of a cleaning device in a side view similar to that of FIG. 1, nozzles for cleaning liquid being provided on both sides of a wiping element;

4 is a partial view of the inner layer of a casing of the ultrasound generator;

Fig. 5 is a partial front view of the ultrasonic generator with the casing; and

6 and FIG. 7 partial side views of further cleaning devices with an additional cleaning cloth.

In the drawing, 1 denotes a device in FIG. 1, which is used to clean blanket cylinders 3 of an offset printing machine 2. In the drawing, only the essential parts are indicated schematically. The blanket cylinder 3 is driven according to arrow 3 '. The blanket cylinder 3 is assigned a cleaning device 4, which consists at least of an ultrasound generator 5, which is arranged with its axis of rotation 6 parallel to an axis of rotation 10 (FIG. 2) of the blanket cylinder 3.

The ultrasound generator 5 or ultrasound transmitter generates high-frequency sound waves which, for example, generate small, initially growing bubbles in liquids, which ultimately implode and thereby develop enormous heat locally for a short time. These extreme conditions create an unusual environment for chemical reactions. With compression, for example, a positive pressure is exerted on the liquid that pushes the molecules together. Expansion, however, creates negative pressure that pulls them apart. During the expansion phase, a sound wave can be sufficient create high intensity bubbles. In order for a bubble to form, such a negative pressure must occur during the expression phase of the sound wave that it overcomes the tensile strength of the liquid. The decrease in bladder size with increasing frequency means that the duration of the collapse decreases. The result is that the mechanical effects of the collapse are reduced, since it decreases in severity due to the shorter duration. Therefore, there is a relatively strong mechanical effect in the frequency range from 2 x 10 ⁵ s ^"1 to 6 x 10 ⁵ s ^{" 1} . Above about I x 10 ^δ s ^"1 , these effects decrease significantly. The advantageous design of the ultrasound generator enables use even under extreme conditions such as dust, dirt, high temperatures and moisture. The surface of the ultrasound processor or ultrasound generator 5, which the Ultrasonic radiation consists of materials such as stainless steel or coated stainless steel, whereby the layer material has a lower surface hardness than the steel.

The ultrasonic generator 5 shown in FIGS. 1 to 3 with its converter 5.1 has bearing pins 6.1 on both sides of its end, which are rotatably received in side parts or wall parts of a holder 14 arranged at a distance from one another. The holder 14, which is only indicated schematically in FIG. 1, rests on an axis 16 and can be moved in accordance with FIG. 1 and arrow 14.1 in the direction of the surface of the rubber cylinder 3 and thus also be pressed against the surface. The ultrasound generator 5 is adjusted by means of an adjusting device (not shown in the drawing), the movement of the adjustment of the holder 14 being controlled by a processor at a specific clock frequency. The ultrasound generator 5 is driven by a drive device schematically indicated by 9 in FIG. 2, which can be designed as a cam disk gear or swashplate gear and which causes the ultrasound generator 5 with its axis of rotation 6 to move axially parallel to the axis 10 of the blanket cylinder 3 in accordance with 6.3. Furthermore, the drive device 9 is designed in such a way that a clocked movement of the ultrasound generator 5 in the direction of the surface of the rubber blanket cylinder 3 and in the opposite direction takes place, so that the surface of the rubber blanket cylinder 3 only comes into brief contact with the surface of the ultrasound generator 5. y

The ultrasound generator 5 is covered with a fabric-like coating 7 or a stocking which covers the outer surface of the ultrasound generator 5. The fabric-like cover 7 can consist of a mesh rubberized terry sock, so that the surface of the ultrasound generator forms a brush-like wiping element.

The cleaning device 4 also includes a rotatably mounted scraper element, which is referred to below as a doctor blade 8. The doctor blade 8 can be started or driven via a drive device, not shown in the drawing. The stripping element or the doctor blade 8 can consist of a square material or a squeeze roller and is at least temporarily in contact with the surface of the ultrasound generator 5 and scrapes dirt out of the brush-like coating 7.

In the area of the surface of the blanket cylinder 3 to be cleaned there is a cleaning device, wherein in the drawing only the cleaning nozzle 11 according to FIG. 1 or the further exemplary embodiment according to FIG. 3, two cleaning nozzles 12 and 13 are provided on both sides of the doctor blade 8. Instead of a cleaning nozzle, a flat nozzle, slot nozzle or numerous nozzles arranged side by side can be provided.

The cleaning nozzle 11 according to FIG. 1 is located above the contact point between the surface of the blanket cylinder 3 and the surface of the ultrasound generator 5. In the drawing according to FIG. 1, the one nozzle 11 is shown, which can be designed, for example, as a flat nozzle and with their slot opening extends over the entire width of the blanket cylinder 3. Furthermore, it is possible that numerous cleaning nozzles 11 arranged side by side according to FIG. 1 are provided in front of the surface of the blanket cylinder 3. The nozzle 11 is connected via a line 11.1 to a storage container (not shown in the drawing), so that in this way washing liquid can be supplied to the surface of the blanket cylinder 3 or the ultrasound generator 5 via the cleaning nozzle 11. The cleaning fluid 11.2 is returned to a return tank via a tank 14.2 connected to a holder 14 via a return line not shown in the drawing. leads, which serves to absorb the dirty washing liquid. The dirty washing liquid can be processed in the reflux container via appropriate filter elements, so that it is then available again as a cleaning liquid.

3, as already mentioned, the doctor 8 is surrounded by two cleaning nozzles 12 and 13, so that the cleaning liquid 11.2 is sprayed onto the surface of the ultrasound generator 5 from below. Like the nozzle 11, the two nozzles 12 and 13 can also be connected to a return tank via a line 11.1.

The distance of the outlet opening of the individual nozzles to the surface of the parts to be cleaned or the angle between the nozzle axis and the surface of the ultrasound generator 5 is fixed in the exemplary embodiment. However, it is also possible to change the setting of the nozzles by a corresponding device, not shown in the drawing.

Cavitation is generated by means of the ultrasound generator 5 with the applied liquid, as already described at the beginning. The extent and the effect of the cavitation depend in particular on the parameters of the ultrasound field. So z. B. frequencies, amplitude and sound intensity of the ultrasonic generator 5 such as cavitation waves, size of the bubble radii, strength of the bladder collapse and spatial dimensions of the cavitation can be regulated. On the basis of a quantitative description of the ultrasonic fields, cavitation processes can thus be optimized and ultrasonic generators 5 can be modulated in terms of the type of surfaces and soiling.

For this purpose, the ultrasound generator 5 is designed as an intensity-modulated and / or amplitude-modulated and / or frequency-modulated and / or pulsed ultrasound transmitter. The ultrasound generated by the ultrasound transmitter 5 is in a frequency band between 2 x 10 ⁴ s ^"1 and 2 x 10 ⁵ s ^{" 1} or in a frequency band between 2 x 10 ⁴ s ^"1 and 10 ⁵ s ^_1 or in a frequency band between 4 x 10 ⁴ s ^{' 1} and 2 x 10 ⁵ s ^"1 used.

As already mentioned, ultrasound cleaning is effected by means of the ultrasound generator 5, the waves of the ultrasound being used Formation of gas bubbles. This creates a periodic compression and expansion of the gas bubbles. The gas in the bubbles can reach a high temperature and the implosion of the bubbles creates a targeted pressure. This results in an advantageous ultrasonic cleaning of the blanket cylinder 3 to be cleaned. The cleaning effect is significantly improved by the advantageous configuration of the surface of the ultrasound generator 5. Due to the advantageous arrangement and arrangement of the ultrasonic generator 5 with the advantageous placement of the cleaning nozzles, rollers and cylinders of the printing presses can be cleaned in the installed state. This also makes it possible to carry out cleaning largely without solvents so that the risk of explosion can be eliminated. This reduces the hazard potential, since no or almost no solvent vapors occur. Due to the metered supply of the cleaning liquid 11.2 in connection with the ultrasound generator 5, a direct cleaning with ultrasound is carried out very thoroughly. The time intervals between the cleaning processes can be changed depending on the paper used and the color.

This cleaning device makes it possible to accommodate them in a space-saving manner in a small space, which is not possible with belt cloth cleaning.

The sheathing of the brush is illustrated in more detail in FIGS. 4 and 5. The ultrasound generator 5 can have a very hard surface, which consists, for example, of stainless steel or of another suitable material. 4 and 5, the ultrasound generator 5 is surrounded by a mesh 18, in which numerous brush hairs 19 are firmly connected to the mesh 18 according to FIG. 5. The mesh grid 18 completely surrounds the surface of the ultrasound generator 5 and serves to hold the individual brush hairs 19 or bundled brush hairs according to FIG Surface of the cylindrical ultrasound generator 5 radially outwards. The rotary body or the ultrasound generator 5 and thus the brushes 19 are completely encased by a casing 20. give. The sheathing or the fabric-like coating 20 can consist of a close-meshed fabric.

The surface of the ultrasound generator 5 has a layer material, the surface hardness of which is less than the surface hardness of the base body of the ultrasound generator 5. As already mentioned, the surface of the ultrasound generator 5 can consist of a metal surface, stainless steel surface or of another, very hard material.

6, an internally toothed 23 brush belt 19b runs over an ultrasound generator 5 and a further roller which, like the ultrasound generator 5, is provided with complementary external teeth 25. Furthermore, an additional cleaning cloth is passed through the gusset between the cylinder 3 to be cleaned and the ultrasound generator 5 via the ultrasound generator 5 with the brush band 19b. The cylinder 3 is an impression cylinder with grippers 24. The additional cleaning cloth is unwound from a clean cloth roll 21 and wound onto a dirty cloth roll 22.

In the cleaning device according to FIG. 7, an additional cleaning cloth is guided over an ultrasound transmitter, which is covered with a brush 19c.

List of reference numbers

1 device for cleaning blanket cylinders

2 offset printing machine

3 cylinders, blanket cylinders, rotating body 3 'arrow for driving part 3

4 cleaning device

5 ultrasound generator, ultrasound transmitter 5.1 converter

6 axis of rotation of the ultrasound generator

6.1 journal

6.2 wall part

6.3 Arrow from part 5

7 fabric-like cover, stocking

8 swivel-mounted scraper element, squeegee

9 drive device, such as swash plate drive

10 axis, axis of rotation of the blanket cylinder

11 cleaning nozzles, flat nozzle, slot nozzle

(= Liquid supply device)

11.1 Management

11.2 Cleaning fluid

12 cleaning nozzles, flat nozzle, slot nozzle, numerous nozzles arranged side by side

13 cleaning nozzles, flat nozzles, slot nozzles, numerous nozzles arranged side by side

14 bracket

14.1 Arrow swivel direction of bracket 14

14.2 Container 16 axis

18 mesh grids

19 brush hair, brush 19b brush band

19c brush coating

20 sheathing, fabric-like covering

21 cleaning cloth roll

22 Dirty cloth roll Internal toothing of the brush belt gripper External toothing of the roller

Claims

Expectations

1. Device for cleaning the surface of a preferably circular-cylindrical rotating body, in particular a roller or a cylinder (3) of a printing machine, which is driven in rotation about an axis, with a circular-cylindrical ultrasonic generator (5) with radial radiation that is adjustable with respect to the rotating body and is attached to it Outer jacket has a soft coating which can be wetted with cleaning liquid (11.2) and rotates about an axis parallel to the axis (10) of the rotating body

(6) can be driven.

2. Device according to claim 1, characterized in that the ultrasound generator (5) is deliverable to the rotating body and can be disengaged therefrom.

3. Device according to claim 1 or 2, characterized in that the ultrasonic generator (5) is adjustable parallel to its axis (6), preferably in a reciprocating actuating movement with a stroke of 1 mm to 50 mm.

4. Device according to one of claims 1 to 3, characterized in that the ultrasonic generator (5) is adjustable parallel to its essential radiation direction, and preferably in a reciprocating adjusting movement in the longitudinal wave direction with a stroke of 1 μ to 240 μ , preferably 10 μ to 100 μ.

5. Device according to one of claims 1 to 4, characterized in that for the adjustment of the ultrasonic generator (5), a cam mechanism or a swash plate gear or a linear drive is provided, or the ultrasonic generator (5) is accommodated in a holder (14) which by a Axis (16) is pivotally mounted.

6. Device according to one of claims 1 to 5, characterized in that the ultrasound generator (5) is clocked in one or more of its movements and / or its ultrasound radiation.

7. Device according to one of claims 1 to 6, characterized in that the ultrasonic generator (5) can be pressed onto the rotating body.

8. Device according to one of claims 1 to 7, characterized in that the ultrasonic generator (5) is sprung against the rotating body.

9. Device according to one of claims 1 to 8, characterized in that one or more nozzle (s) (11, 12, 13) is / are provided for supplying cleaning liquid to the coating of the ultrasonic generator (5).

10. The device according to claim 9, characterized by a nozzle (11, 12, 13) whose outlet opening extends approximately over the entire length of the rotary body and / or ultrasonic generator (5).

11. The device according to claim 9, characterized by a plurality of nozzles (11, 12, 13) arranged in a row.

12. Device according to one of claims 1 to 11, characterized in that the coating of the ultrasonic generator (5) is designed as a casing (19c, 20) of the same.

13. Device according to one of claims 1 to 11, characterized in that the coating of the ultrasound generator (5) is a self-contained band (19b), which over the ultrasound generator

(5) and at least one further roller (25) runs.

14. Device according to one of claims 1 to 13, characterized by a stripping element (8) which acts against the coating of the ultrasonic generator (5).

15. The apparatus according to claim 13 and 14, characterized in that the stripping element (8) is arranged on the further roller (25).

16. The device according to one of claims 1 to 15, characterized in that the stripping element (8) is rotatably mounted.

17. Device according to one of claims 1 to 16, characterized in that at least one nozzle (12, 13) is provided for cleaning fluid on both sides of the wiping element (8).

18. Device according to one of claims 1 to 17, characterized in that the coating of the ultrasonic generator (5) is brush-like (19, 19b, 19c) and / or consists of foam and / or fabric (20).

19. Device according to one of claims 1 to 18, characterized in that the coating of the ultrasonic generator (5) consists of a mesh-like and / or mesh-gummed fabric (20) which is penetrated by bristles (19).

20. Device according to one of claims 1 to 19, characterized in that the covering of the ultrasonic generator (5) consists of terry cloth or molton.

21. Device according to one of claims 1 to 20, characterized in that a web of cleaning cloth runs over the ultrasonic generator (5), which comes from a clean cloth roll (21) and is wound up to a dirty cloth roll (22).

22. The apparatus according to claim 21, characterized in that the web can be wetted with cleaning fluid on the ultrasonic generator side, in particular can be sprayed with one or more nozzle (s).

23. Device according to one of claims 1 to 22, characterized in that the ultrasound generator (5) is designed as an intensity-modulated and / or amplitude-modulated and / or frequency-modulated and / or pulsed ultrasound transmitter.

24. Device according to one of claims 1 to 23, characterized in that the ultrasound generated by the ultrasound transmitter (5) in a frequency band between 2 x 10 ⁴ s ^"1 and 2 x 10 ⁶ s ^{" 1} or in a frequency band between 2 x 10 ⁴ s ^{' 1} and 10 ⁵ s ^"1 or in a frequency band between 4 x 10 ⁴ s ^{" 1} and 2 x 10 ⁵ s ^"1 .

25. Device according to one of claims 1 to 24, characterized in that the ultrasonic generator (5) during at least one only one preliminary stage for cavitation in the cleaning liquid.

26. Device according to one of claims 1 to 25, characterized in that at least one welding sonotrode is used as the ultrasound generator (5).

27. Device according to one of claims 1 to 26, characterized in that the ultrasound generator (5) has piezoelectric transducers which are distributed with an axial offset over the circumference of the ultrasound generator (5).

28. Device according to one of claims 1 to 27, characterized in that the outer jacket of the ultrasonic generator (5) consists of a layer material whose surface hardness is less than the surface hardness of the base body.