EP4076768B1 - Cleaning device for cleaning a nozzle applicator and corresponding cleaning method - Google Patents

Description

The invention relates to a cleaning system for cleaning a nozzle applicator which is designed for applying a coating agent to a component and has several application nozzles in a nozzle area in order to dispense the coating agent in an application direction through the application nozzles during application.

In modern paint shops for painting automotive body components, rotary atomizers are typically used as application devices, emitting a relatively wide spray pattern of the paint to be applied. When changing colors, such rotary atomizers must be cleaned to prevent contamination by the old paint. For this purpose, state-of-the-art methods (e.g., WO 2012/069137 A1 Cleaning devices are known that enable the cleaning of rotary atomizers. For this purpose, the rotary atomizer to be cleaned is inserted into the cleaning device and then cleaned within the device. Firstly, an internal cleaning of the rotary atomizer takes place by rinsing out residues of the old paint. Secondly, an external cleaning of the rotary atomizer also takes place within the cleaning device by rinsing the outer surfaces of the rotary atomizer with a cleaning agent.

In a more recent development line, however, rotary atomizers are not used as application devices, but rather so-called printheads, such as those from... DE 10 2013 002 412 A1 These printheads are also known as nozzle applicators because they have numerous application nozzles, each emitting a relatively narrow jet of coating material. Unlike conventional rotary atomizers, nozzle applicators do not emit a spatially extended spray of the coating material, but rather a spatially narrow jet that may, for example, be continuous along the length of the jet or consist of several coating material droplets spaced apart along the length of the jet. These nozzle applicators also require cleaning when changing colors. However, existing cleaning devices are designed for rotary atomizers and are therefore only suitable to a limited extent for cleaning nozzle applicators.

Regarding the state of the art, it should also be noted that DE 10 2016 014 955 A1 , EP 1 005 997 A1 , JP 2012-096 464 A , JP 2012-130 822 A and DE 10 2016 014 951 A1 .

Finally, it reveals EP 3 725 421 A1 a cleaning system according to the preamble of claim 1. However, this known cleaning system is not yet fully satisfactory.

The invention is therefore based on the objective of creating an improved cleaning system.

This problem is solved by a cleaning system according to the invention as claimed in claim 1.

The invention provides a cleaning device that is structurally adapted for cleaning a nozzle applicator. It should be noted that the term "nozzle applicator" used in the context of the invention differs from conventional rotary or air atomizers. The nozzle applicator does not emit a spatially extended spray of the coating material, as is the case with a conventional rotary atomizer. Rather, the nozzle applicator applies a spatially narrowly defined jet of coating material, which can have a narrow spray angle of less than 10°, 5°, or even less than 2°. Furthermore, it should be noted that the jet of coating material from the nozzle applicator can optionally consist of individual droplets of coating material spaced apart along the longitudinal direction of the jet. Alternatively, however, the individual jets of coating material can also be connected along the longitudinal direction of the jet. Furthermore, it should be mentioned that the nozzle applicator preferably operates essentially without overspray, in particular with a transfer efficiency of more than 80%, 90% or even more than 95%. In one embodiment of the invention, the nozzle applicator is a printhead such as those made, for example, from DE 10 2013 002 412 A1 is known. Finally, it should be mentioned that the nozzle applicator preferably has numerous application nozzles, for example more than 5, 10, 20, 30 or even more than 50 application nozzles, which may be arranged, for example, in a row or in several adjacent rows.

In accordance with known cleaning devices for rotary atomizers, the cleaning device according to the invention also has a cleaning agent supply via which a cleaning agent can be supplied for cleaning the nozzle applicator. For example The cleaning agent supply can include a pulsed air supply and a detergent supply, as will be described in detail below.

Furthermore, the cleaning device according to the invention also has a docking interface in accordance with the known cleaning devices for rotary atomizers in order to dock the nozzle applicator to be cleaned to the cleaning device.

The cleaning device according to the invention also provides that the docking interface is designed such that the cleaning agent can be flushed into the nozzle applicator through the application nozzles in the opposite direction to the normal application direction. In contrast, known cleaning devices for rotary atomizers are only suitable for spraying the outer surfaces of the rotary atomizers with cleaning agent. However, it is not possible to flush cleaning agent into the rotary atomizer from the outside. Flushing a cleaning agent through the application nozzles in the opposite direction to the normal application direction is advantageous because it allows blockages or partial contamination of the nozzle channel of the application nozzles to be eliminated by flushing the blockage or contamination inwards.

In a preferred embodiment of the invention, the docking interface has a seal that, when docked, provides a fluid-tight and optionally also a pressure-tight seal to the nozzle area of the applicator, allowing the cleaning agent to be flushed into the nozzle applicator through the application nozzles in the opposite direction to the normal application direction. This is advantageous to prevent the cleaning agent from simply being released into the environment when the nozzle area of the applicator is exposed to it. Preferably, the seal is annular and surrounds the nozzle area containing the application nozzles. It should be noted that the seal does not necessarily have to be round, but can also be rectangular. In the preferred embodiment, the cleaning device on the one hand and the nozzle applicator on the other thus enclose a flushing chamber, which is sealed off from the environment by the seal. The cleaning device can therefore introduce cleaning agents (e.g., pulsed air, rinsing agents) into the flushing chamber, so that the application nozzles of the nozzle applicator are exposed to the cleaning agent on the outside. The cleaning agent can then enter the nozzle applicator through the application nozzles in the opposite direction to the normal application direction in order to dissolve blockages or contamination of the application nozzles.

In a preferred embodiment of the invention, the cleaning agent supply of the cleaning device comprises at least one controllable cleaning agent valve to regulate the flow of the cleaning agent. Furthermore, the cleaning agent supply preferably includes an air supply to supply pulsed air, as is known in the prior art. A controllable compressed air valve is arranged in the air supply to control the supplied pulsed air or, optionally, an airflow for nozzle drying. In addition, the cleaning agent supply preferably includes a rinsing agent supply to supply a rinsing agent. A controllable rinsing agent valve is also arranged in the rinsing agent supply to control the rinsing agent flow. It should be noted that the term "rinsing agent" used within the scope of the invention preferably refers to liquid rinsing agents that are adapted to the specific paint being used. The term "rinsing agent" thus also includes water-based liquids as well as liquids based on organic solvents. This also includes mixtures that contain other substances besides water and/or organic solvents, such as wetting agents, co-solvents, or other additives. Furthermore, the cleaning device according to the invention has a return system to remove residual coating material. A controllable return valve can be arranged in the return system to regulate the material flow. The return system and the cleaning agent supply of the cleaning device preferably open into the aforementioned inlet chamber between the cleaning device and the nozzle applicator.

Furthermore, it should be mentioned that the nozzle applicators to be cleaned preferably also have at least one cleaning agent supply, and a cleaning agent valve may also be arranged in the cleaning agent supply of the nozzle applicator. In the preferred embodiment of the invention, the cleaning agent supply of the nozzle applicator has a compressed air supply with a compressed air valve and a rinsing agent supply with a rinsing agent valve in order to alternately supply pulsed air and rinsing agent, as is known per se from the prior art of rotary atomizers. On the outlet side, the compressed air supply and the rinsing agent supply preferably open into an additional release valve that can control the flow of the rinsing agent or the pulsed air. In addition, the nozzle applicator also preferably has a return line to remove residues of the coating material. A return valve is also preferably arranged in the return line of the nozzle applicator to control the material flow into the return line of the nozzle applicator. Furthermore, it should be mentioned that the The nozzle applicator preferably has at least one main valve that controls the dispensing of the coating material. With a plurality of application nozzles, it is possible that each application nozzle or group of application nozzles is assigned its own main valve. Alternatively, however, the nozzle applicator may have only a single main valve for all application nozzles. The main valve is of secondary importance within the scope of the invention, so only a single main valve is mentioned below. It is understood, however, that a main valve can be provided for each individual application nozzle.

• Das Reinigungsmittelventil der Reinigungsvorrichtung, insbesondere das Druckluftventil und das Spülmittelventil der Reinigungsvorrichtung,
• das mindestens eine Rückführventil der Reinigungsvorrichtung,
• das Reinigungsmittelventil des Düsenapplikators, insbesondere das Druckluftventil, das Spülmittelventil und ggf. das Freigabeventil,
• das mindestens eine Rückführventil des Düsenapplikators, und/oder
• das mindestens eine Hauptventil des Düsenapplikators.

Furthermore, the cleaning device according to the invention preferably comprises a control unit that controls the following valves:

• The cleaning agent valve of the cleaning device, in particular the compressed air valve and the rinsing agent valve of the cleaning device,
• the cleaning device's at least one return valve
• the cleaning agent valve of the nozzle applicator, in particular the compressed air valve, the rinsing agent valve and, if applicable, the release valve,
• the at least one return valve of the nozzle applicator, and/or
• the at least one main valve of the nozzle applicator.

The control unit can activate several different cleaning modes by appropriately controlling the various valves; these are briefly described below.

• Das Spülmittelventil der Reinigungsvorrichtung wird durchgehend oder pulsierend geöffnet,
• das Druckluftventil der Reinigungsvorrichtung wird durchgehend oder pulsierend geöffnet,
• das Rückführventil der Reinigungsvorrichtung wird geschlossen,
• das Spülmittelventil des Düsenapplikators wird geschlossen,
• das Druckluftventil des Düsenapplikators wird geschlossen und
• das mindestens eine Rückführventil des Düsenapplikators wird geöffnet.

In the first cleaning mode, the nozzle applicator is docked to the docking interface of the cleaning device. Compressed air and cleaning agent are then flushed from the cleaning device, against the normal application direction, through the application nozzles into the nozzle applicator and exit the nozzle applicator via the return flow. The various valves are controlled as follows:

• The detergent valve of the cleaning device is opened continuously or pulsatingly,
• The compressed air valve of the cleaning device is opened continuously or in pulses,
• the return valve of the cleaning device is closed,
• The rinsing valve of the nozzle applicator is closed,
• The compressed air valve of the nozzle applicator is closed and
• At least one return valve of the nozzle applicator is opened.

This first cleaning mode is advantageous because stubborn blockages or impurities in the application nozzles can be loosened by passing pulsed air and rinsing agent through the blocked application nozzles against the normal application direction.

• Das Spülmittelventil der Reinigungsvorrichtung wird geschlossen,
• das Druckluftventil der Reinigungsvorrichtung wird geschlossen,
• das mindestens eine Rückführventil der Reinigungsvorrichtung wird geöffnet,
• das Spülmittelventil des Düsenapplikators wird durchgehend oder pulsierend geöffnet,
• das Druckluftventil des Düsenapplikators wird durchgehend oder pulsierend geöffnet, und
• das mindestens eine Rückführventil des Düsenapplikators wird geschlossen.

In a second cleaning mode, the nozzle applicator is docked to the docking interface of the cleaning device. Compressed air and cleaning agent are then flushed from the nozzle applicator through the application nozzles into the cleaning device in the normal application direction and then exit the cleaning device via the return path. The various valves are controlled as follows:

• The detergent valve of the cleaning device is closed,
• The compressed air valve of the cleaning device is closed.
• at least one return valve of the cleaning device is opened,
• The rinsing agent valve of the nozzle applicator is opened continuously or pulsatingly,
• The compressed air valve of the nozzle applicator is opened continuously or in pulses, and
• At least one return valve of the nozzle applicator is closed.

The second cleaning mode can be used alternately with the first cleaning mode to loosen stubborn blockages or impurities by alternating forward and backward movements of the cleaning agent or pulsed air.

• Das Spülmittelventil der Reinigungsvorrichtung wird geschlossen,
• das Druckluftventil der Reinigungsvorrichtung wird geschlossen,
• das mindestens eine Rückführventil der Reinigungsvorrichtung wird geschlossen,
• das Spülmittelventil des Düsenapplikators wird durchgehend oder pulsierend geöffnet,
• das Druckluftventil des Düsenapplikators wird durchgehend oder pulsierend geöffnet, und
• das mindestens eine Rückführventil des Düsenapplikators wird geöffnet.

Alternatively, the control unit can also set a third cleaning mode, in which the nozzle applicator is docked to the cleaning device's docking interface. This allows compressed air and cleaning solution to enter the nozzle applicator and then exit it via the nozzle's return path. In this third cleaning mode, the cleaning device is not actively involved but merely serves to seal the nozzle area to prevent contamination of the surrounding environment. In this third cleaning mode, the various valves are controlled as follows:

• The detergent valve of the cleaning device is closed,
• The compressed air valve of the cleaning device is closed.
• at least one return valve of the cleaning device is closed,
• The rinsing agent valve of the nozzle applicator is opened continuously or pulsatingly,
• The compressed air valve of the nozzle applicator is opened continuously or in pulses, and
• At least one return valve of the nozzle applicator is opened.

• Das Spülmittelventil der Reinigungsvorrichtung wird durchgehend oder pulsierend geöffnet,
• das Druckluftventil der Reinigungsvorrichtung wird durchgehend oder pulsierend geöffnet,
• das mindestens eine Rückführventil der Reinigungsvorrichtung wird geöffnet,
• das Spülmittelventil des Düsenapplikators wird geschlossen,
• das Druckluftventil des Düsenapplikators wird geschlossen, und
• das mindestens eine Rückführventil des Düsenapplikators wird geschlossen.

Furthermore, the cleaning device according to the invention also enables a fourth cleaning mode in which the nozzle applicator is also docked to the docking interface of the cleaning device. Compressed air and cleaning agent are then flushed in from the cleaning device and exit the cleaning device again via the return path. In this mode, the nozzle applicator plays no active role, since the cleaning agent (e.g., compressed air and cleaning agent) is supplied by the cleaning device and also discharged via the cleaning device. In this fourth cleaning mode, the various valves are controlled as follows:

• The detergent valve of the cleaning device is opened continuously or pulsatingly,
• The compressed air valve of the cleaning device is opened continuously or in pulses,
• at least one return valve of the cleaning device is opened,
• The rinsing valve of the nozzle applicator is closed,
• The compressed air valve of the nozzle applicator is closed, and
• At least one return valve of the nozzle applicator is closed.

• Das Spülmittelventil der Reinigungsvorrichtung wird geschlossen,
• das Druckluftventil der Reinigungsvorrichtung wird durchgehend oder pulsierend geöffnet,
• das mindestens eine Rückführventil der Reinigungsvorrichtung wird geschlossen,
• das Spülmittelventil des Düsenapplikators wird geschlossen,
• das Druckluftventil des Düsenapplikators wird geschlossen, und
• das mindestens eine Rückführventil des Düsenapplikators wird geöffnet.

Furthermore, the cleaning device according to the invention also enables a fifth cleaning mode in which the nozzle applicator is also docked to the docking interface of the cleaning device, with compressed air flowing from the cleaning device against the normal application direction through the application nozzles of the nozzle applicator and then exiting the nozzle applicator through the at least one return line of the nozzle applicator. It should be noted that in this fifth cleaning mode no rinsing agent is used, but only compressed air to remove contaminants from and dry the internal lines and surfaces of the nozzle applicator. For this purpose, the various valves are controlled as follows:

• The detergent valve of the cleaning device is closed,
• The compressed air valve of the cleaning device is opened continuously or in pulses,
• at least one return valve of the cleaning device is closed,
• The rinsing valve of the nozzle applicator is closed,
• The compressed air valve of the nozzle applicator is closed, and
• At least one return valve of the nozzle applicator is opened.

• Das Spülmittelventil der Reinigungsvorrichtung wird geschlossen,
• das Druckluftventil der Reinigungsvorrichtung durchgehend oder pulsierend geöffnet,
• das mindestens eine Rückführventil der Reinigungsvorrichtung wird geschlossen,
• das Spülmittelventil des Düsenapplikators wird geschlossen,
• das Druckluftventil des Düsenapplikators wird geschlossen, und
• das mindestens eine Rückführventil des Düsenapplikators wird geschlossen.

Finally, the cleaning device according to the invention preferably also enables a sixth cleaning mode, which serves to dry the outer surfaces of the nozzle applicator. In this mode, the nozzle applicator is undocked from the docking interface of the cleaning device, but remains within the operating range of the cleaning device so that the compressed air emitted by the cleaning device can reach and dry the outer surfaces of the nozzle applicator. For this purpose, the various valves are controlled as follows:

• The detergent valve of the cleaning device is closed,
• the compressed air valve of the cleaning device is continuously or pulsatingly open,
• at least one return valve of the cleaning device is closed,
• The rinsing valve of the nozzle applicator is closed,
• The compressed air valve of the nozzle applicator is closed, and
• At least one return valve of the nozzle applicator is closed.

• Erster Reinigungsmodus,
• zweiter Reinigungsmodus,
• optional dritter Reinigungsmodus,
• optional vierter Reinigungsmodus,
• optional fünfter Reinigungsmodus,
• optional sechster Reinigungsmodus.

As mentioned above, the control unit can switch between different cleaning modes to achieve the most effective cleaning. For example, the control unit can switch between the first and second cleaning modes to rinse the application nozzles alternately in the normal application direction and against the normal application direction. Furthermore, the control unit can activate a sequence of different cleaning modes during a cleaning process, for example, in the following order:

• First cleaning mode,
• second cleaning mode,
• optional third cleaning mode,
• optional fourth cleaning mode,
• optional fifth cleaning mode,
• Optional sixth cleaning mode.

It should also be mentioned that the invention only claims protection for a complete cleaning system, which, in addition to the cleaning device according to the invention, also includes a multi-axis application robot for positioning the nozzle applicator.

Furthermore, the cleaning system according to the invention also includes a jet testing device for checking the coating material jets emitted by the application nozzles, wherein the jet testing device is structurally integrated into the cleaning device. Such jet testing devices are described, for example, in the German patent application. DE 10 2018 131 380 A1 known.

The control unit is connected to the application robot on the output side and controls it. It is also connected to the cleaning device and controls it accordingly. On the input side, the control unit is connected to the blast testing device to incorporate the blast test results. It's worth noting that the control unit is not necessarily contained in a single hardware unit. It can also be distributed across multiple hardware components and implemented entirely or partially in software.

The control unit preferably activates the blast testing device to test the coating material jets emitted by the application nozzles in order to detect blockages or contamination of the application nozzles. Subsequently, the control unit preferably activates the cleaning device to clean the application nozzles. The cleaning can be limited to those application nozzles where the blast testing device has detected a blockage.

Figur 1:

eine schematische Darstellung eines Düsenapplikators, der mit der erfindungsgemäßen Reinigungsvorrichtung gereinigt werden kann,

Figur 2:

eine schematische Darstellung der erfindungsgemäßen Reinigungsvorrichtung,

Figur 3:

eine schematische Darstellung der erfindungsgemäßen Reinigungsvorrichtung beim Reinigen des Düsenapplikators, der von einem Applikationsroboter geführt wird. 9

Figur 4:

eine schematische Darstellung einer Strahlprüfungseinrichtung zur Erkennung einer Verstopfung der Applikationsdüsen des Düsenapplikators,

Figur 5:

eine schematische Darstellung der Steuerung der Strahlprüfungseinrichtung, des Applikationsroboters und der Ventile des Düsenapplikators und der Reinigungsvorrichtung,

Figur 6A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem angedockten Düsenapplikator in einem ersten Reinigungsmodus zum Durchspülen der Applikationsdüsen entgegen der normalen Applikationsrichtung,

Figur 6B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des ersten Reinigungsmodus,

Figur 7A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem angedockten Düsenapplikator in einem zweiten Reinigungsmodus, zum Durchspülen der Applikationsdüsen in der normalen Applikationsrichtung,

Figur 7B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des zweiten Reinigungsmodus,

Figur 8A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem angedockten Düsenapplikator in einem dritten Reinigungsmodus zum internen Spülen der Reinigungsvorrichtung,

Figur 8B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des dritten Reinigungsmodus,

Figur 9A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem angedockten Düsenapplikator in einem vierten Reinigungsmodus zum internen Spülen des Düsenapplikators,

Figur 9B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des vierten Reinigungsmodus,

Figur 10A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem angedockten Düsenapplikator in einem fünften Reinigungsmodus zum Ausblasen und Trocknen der inneren Leitungen und Oberflächen des Düsenapplikators,

Figur 10B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des fünften Reinigungsmodus,

Figur 11A:

eine schematische Darstellung der Reinigungsvorrichtung mit dem abgedockten Düsenapplikator in einem sechsten Reinigungsmodus zum Trocknen der äußeren Oberflächen des Düsenapplikators,

Figur 11B:

ein Flussdiagramm zur Verdeutlichung der Verfahrensschritte des sechsten Reinigungsmodus.

Other advantageous embodiments of the invention are characterized in the dependent claims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to the figures. The figures show:

Figure 1:

a schematic representation of a nozzle applicator that can be cleaned with the cleaning device according to the invention,

Figure 2:

a schematic representation of the cleaning device according to the invention,

Figure 3:

A schematic representation of the cleaning device according to the invention during cleaning of the nozzle applicator, which is guided by an application robot. 9

Figure 4:

a schematic representation of a beam testing device for detecting a blockage of the application nozzles of the nozzle applicator,

Figure 5:

a schematic representation of the control system of the beam testing device, the application robot and the valves of the nozzle applicator and the cleaning device,

Figure 6A:

a schematic representation of the cleaning device with the docked nozzle applicator in a first cleaning mode for rinsing the application nozzles against the normal application direction,

Figure 6B:

a flowchart to illustrate the process steps of the first cleaning mode,

Figure 7A:

a schematic representation of the cleaning device with the docked nozzle applicator in a second cleaning mode, for rinsing the application nozzles in the normal application direction,

Figure 7B:

a flowchart to illustrate the process steps of the second cleaning mode,

Figure 8A:

a schematic representation of the cleaning device with the attached nozzle applicator in a third cleaning mode for internal rinsing of the cleaning device,

Figure 8B:

a flowchart to illustrate the process steps of the third cleaning mode,

Figure 9A:

a schematic representation of the cleaning device with the docked nozzle applicator in a fourth cleaning mode for internal rinsing of the nozzle applicator,

Figure 9B:

a flowchart to illustrate the process steps of the fourth cleaning mode,

Figure 10A:

a schematic representation of the cleaning device with the docked nozzle applicator in a fifth cleaning mode for blowing out and drying the inner pipes and surfaces of the nozzle applicator,

Figure 10B:

a flowchart to illustrate the process steps of the fifth cleaning mode,

Figure 11A:

a schematic representation of the cleaning device with the detached nozzle applicator in a sixth cleaning mode for drying the outer surfaces of the nozzle applicator,

Figure 11B:

A flowchart to illustrate the process steps of the sixth cleaning mode.

Figure 1 Figure 1 shows a schematic representation of a nozzle applicator 1, which can be cleaned by a cleaning device 2 according to the invention, as will be described in detail below. The nozzle applicator 1 has a nozzle plate 3 with numerous application nozzles 4, wherein the application nozzles 4 can be arranged, for example, in one or more parallel rows. Furthermore, the nozzle applicator 1 has a valve unit 5, which includes at least one main valve HV that controls the paint flow through a paint feed 6. The valve unit 5 also has a rinsing agent feed 7 with a rinsing agent valve V and a pulsed air feed 8 with a pulsed air valve PL. Downstream of the pulsed air valve 8 and the rinsing agent valve 7, a common release valve FGV is arranged, which releases the rinsing agent or the pulsed air. In addition, the valve unit 5 of the nozzle applicator 1 has a return line 9 to allow the return of coating agent residues. In the return line 9 there is a controllable return valve RF.

The drawing in Fig. 1 This shows the valve positions during application operation. The main valve HV is open, allowing paint to be supplied via the paint feed 6 and exit the application nozzles 4 in the direction of the arrow. During this normal application operation, the rinsing agent valve V, the pulse air valve PL, the release valve FGV, and the return valve RF of the nozzle applicator 1 are closed.

The valve position is indicated in the drawings below by a filled valve symbol representing a closed valve, while an unfilled valve symbol representing a fully or pulsatingly open valve.

Figure 2 Figure 1 shows a schematic representation of the cleaning device 2 according to the invention for cleaning the nozzle applicator 1. Figure 1 The cleaning device 2 thus has a valve unit 10, which can also be referred to as a backflush unit, and is connected to a rinsing agent supply 11, a pulsed air supply 12, and a return line 13. A rinsing agent valve V _RSE is located in the rinsing agent supply 11, a pulsed air valve PL _RSE is located in the pulsed air supply 12, and a return valve RF _RSE is located in the return line 13.

Furthermore, it should be mentioned that the cleaning device 2 has a docking interface to allow the nozzle applicator 1 to be docked during a cleaning process. The docking interface includes an annular seal 14, which, in the docked state (see figure 1), Fig. 6A The inlet chamber 15 is sealed to the outside. In the docked state, the nozzle applicator 1 on the one hand and the cleaning device 2 on the other hand enclose the inlet chamber 15, with the seal 14 sealing the inlet chamber 15 to the outside in a fluid-tight and pressure-tight manner. This is advantageous so that the cleaning device 2 can inject cleaning agent and pulsed air into the application nozzles 4 by pressurizing the inlet chamber 15, as will be described in detail below.

Figure 3 Figure 1 shows a schematic representation of the nozzle applicator 1 with the cleaning device 2 and an application robot 16 that guides the nozzle applicator 1. The drawing shows the nozzle applicator 1 at a short distance above the cleaning device 2, i.e., in the undocked state. In this state, the outer surfaces of the nozzle applicator 1 can be blown with compressed air by the cleaning device 2 to dry them, as will be described in detail later.

Figure 4 shows a schematic representation of a beam testing device 17 (see also Fig. 5 ), as they also are in DE 10 2018 131 380 A1 The jet testing device is designed to inspect the coating material jets 18 emitted by the nozzle applicator 1 in order to detect blockages or contamination of the application nozzles 4. For this purpose, the nozzle applicator 1 is positioned by the application robot 16 at a short distance above the cleaning device 2, whereupon the coating material jets 17 are emitted into the cleaning device 2. A backlight source 19 illuminates the coating material jets 18 from the side via a diffuser 20, and a camera 21 captures an image that is transmitted to an evaluation unit 22. The evaluation unit 22 can then determine, by analyzing the camera image, whether the coating material jets 18 are functioning correctly or not, which would indicate a blockage or contamination of the associated application nozzle 4.

Figure 5 Figure 1 shows a schematic representation of the control arrangement for controlling the valve unit 5 of the nozzle applicator 1 and the valve unit 10 of the cleaning device 2 by a control unit 23, which also controls the application robot 16 and receives the evaluation from the beam testing unit 23. It should be noted that the control unit 23 is shown as a single component. However, within the scope of the invention, it is possible for the control unit 23 and its function to be distributed across several different hardware components.

The following describes a first cleaning mode, which is used in the Figures 6A , 6B as shown. In this cleaning mode, the application nozzles 4 of the nozzle applicator 1 are supplied with cleaning agent or pulsed air in the opposite direction to their normal application direction, as shown in Figure 6A indicated by arrows.

In this first cleaning mode, the rinsing agent valve V, the pulse air valve PL, the release valve FGV and the main valve HV are closed in the valve unit 5 of the nozzle applicator 1, while the return valve RF is opened, as shown in the drawing.

In the valve unit 10 of the cleaning device 2, the return valve RF _RSE is closed, while the rinsing agent valve V _RSE and the pulsed air valve PL _RSE are permanently or pulsatingly open.

In this first cleaning mode, cleaning agent and pulsed air are introduced into the inlet chamber 15 by the cleaning device 2 and then flow from there, contrary to the normal application direction, through the application nozzles 4 of the nozzle applicator 1. Finally, coating agent residues, cleaning agent and pulsed air are then discharged via the return 9 of the nozzle applicator 1.

This cleaning operation is shown in the flowchart according to Figure 6B shown in steps S1-S5.

Subsequently, in steps S6-S10, the outer surfaces of the nozzle applicator 1 are dried. For this purpose, the nozzle applicator 1 is undocked from the cleaning device 2 and positioned at a small distance from the cleaning device 2 (step S6). Then Then the pulse air valve PL _RSE of the cleaning device 2 is opened, so that compressed air is released into the inlet chamber 15 and strikes the outer surfaces of the nozzle applicator 1 to dry them (steps S7, S8). Subsequently, all valves are closed again (step S9) and the nozzle applicator 1 is finally completely undocked from the cleaning device 2 (step S10).

The Figures 7A and 7B show a second possible cleaning mode in which the application nozzles 4 of the nozzle applicator 1 are flushed with rinsing agent or pulsed air in their normal flow direction, as shown in Figure 7A as indicated by the arrows.

In this second cleaning mode, the main valve HV and the return valve RF of valve unit 5 of nozzle applicator 1 are closed, while the rinsing agent valve V, the pulse air valve PL and the release valve FGV of valve unit 5 of nozzle applicator 1 are fully or pulsatingly open (step S2).

In the valve unit 10 of the cleaning device 2, the rinsing agent valve V _RSE and the pulsed air valve PL _RSE are closed, while the return valve RF _RSE is open (step S3).

In this second cleaning mode, cleaning agent and pulsed air are thus passed from the nozzle applicator 1 through the application nozzles 4 and then discharged via the return 13 of the cleaning device 2 (S4).

It should be noted that the cleaning device 2 can operate alternately in the two cleaning modes described above. This is advantageous because the cleaning agent is then moved alternately forwards and backwards in the application nozzles 4, thereby effectively loosening and removing blockages in the application nozzles 4.

The Figures 8A and 8B show a third possible cleaning mode in which the supply and removal of pulsed air and rinsing agent take place via the nozzle applicator 1, i.e. the cleaning device 2 is passive in this cleaning mode.

In the valve unit 5 of the nozzle applicator 1, the rinsing valve V, the pulse air valve PL, the release valve FGV and the return valve RF are open, while the main needle valve HV is closed (step S2).

In contrast, in the valve unit 10 of the cleaning device 2, the rinsing agent valve V _RSE , the pulsed air valve PL _RSE and the return valve RF _RSE are closed (step S3).

In this cleaning mode, cleaning agents and pulsed air are supplied via the nozzle applicator 1 and then exit the nozzle applicator 1 again via the return line 9 of the nozzle applicator 1 (step S4).

The Figures 9A and 9B show a fourth possible cleaning mode in which the supply and removal of pulsed air and rinsing agent take place via the cleaning device 2, i.e. the nozzle applicator 1 is passive in this cleaning mode.

In the valve unit 5 of the nozzle applicator 1, the rinsing agent valve V, the pulse air valve PL, the release valve FGV, the return valve RF and the main needle valve HV are closed (step S2).

In contrast, in the valve unit 10 of the cleaning device 2, the rinsing agent valve V _RSE , the pulse air valve PL _RSE and the return valve RF _RSE are open (step S3).

In this cleaning mode, cleaning agents and pulsed air are supplied via the cleaning device 2 and then also leave the cleaning device 2 via the return 13 of the cleaning device 2 (step S4).

The Figures 10A and 10B show a fifth cleaning mode, which is intended to loosen contaminants from the inner surfaces and blow them out of the lines in the nozzle applicator 1.

For this purpose, the rinsing agent valve V, the pulse air valve PL, the release valve FGV and the main valve HV are closed in the valve unit 5 of the nozzle applicator 1, while the return valve RF is opened (step S2).

In the valve unit 10 of the cleaning device 2, on the other hand, the rinsing agent valve V _RSE and the return valve RF _RSE are closed, while the pulse air valve PL _RSE is opened (step S3).

In this cleaning mode, pulsed air is introduced into the inlet chamber 15 via the cleaning device 2 and then flows through the application nozzles 4 in the opposite direction to the normal application direction. Finally, the pulsed air is then discharged via the return 9 of the nozzle applicator 1 (step S4).

Finally, the Figures 11A and 11B a sixth cleaning mode, which serves to dry the outer surfaces of the nozzle applicator 1 after a cleaning process.

For this purpose, the nozzle applicator 1 is detached from the cleaning device 2 and positioned at a small distance from the cleaning device 2 within the effective range of the cleaning device 2, as shown in Figure 11A shown is (step S1).

In valve unit 5 of nozzle applicator 1, all valves are closed, while in valve unit 10 of cleaning device 2, only the pulse air valve PL _RSE is opened (steps S2, S3). Cleaning device 2 then releases pulse air upwards, as indicated by the arrows. The pulse air then flows past the outer surfaces of nozzle applicator 1 and dries them (step S4).

Reference symbol list:

1

nozzle applicator

2

Cleaning device

3

Nozzle plate

4

Application nozzles

5

Valve unit of the nozzle applicator

6

Paint feed of the nozzle applicator

7

Cleaning agent supply of the nozzle applicator

8

Pulsed air supply of the nozzle applicator

9

Return of the nozzle applicator

10

Valve unit of the cleaning device

11

detergent supply of the cleaning device

12

Pulsed air supply of the cleaning device

13

Return of the cleaning device

14

Seal of the docking interface

15

Inlet chamber between nozzle applicator and cleaning device

16

Application robot

17

Beam testing facility

18

Coating agent blasting

19

Backlight source

20

Diffuser

21

camera

22

Evaluation unit

23

control unit

HV

Main valve of the nozzle applicator

PL

Pulse air valve of the nozzle applicator

V

Rinsing valve of the nozzle applicator

FGV

Release valve of the nozzle applicator

RF

Nozzle applicator return valve

VRSE

Cleaning device detergent valve

PLRSE

Pulse air valve of the cleaning device

RFRSE

Return valve of the cleaning device

Claims (14)

1. Cleaning system with

   a) a multi-axis application robot (16) for positioning a nozzle applicator (1),

   b) a cleaning device (2) for cleaning the nozzle applicator (1), which is designed for applying a coating agent to a component and has a plurality of application nozzles (4) in a nozzle region in order to discharge the coating agent during application in an application direction through the application nozzles (4), having

   b1) a rinsing agent supply (11, 12) for supplying a rinsing agent for cleaning the nozzle applicator (1), and

   b2) a docking interface (14) for docking the nozzle applicator (1) to be cleaned to the cleaning device,

   b3) wherein the docking interface is designed to flush the rinsing agent into the nozzle applicator (1) through the application nozzles (4) of the nozzle applicator (1) against the normal application direction, and

   c) a control unit (23), which is connected on the output side to the application robot (16) and the cleaning device (2),
   characterized by

   d) a jet checking device (17) for checking the coating agent jets (18) emitted by the application nozzles (4), wherein the control unit (17) is connected on its input side to the jet checking device (17), wherein the jet checking device (17) is structurally integrated into the cleaning device (2).
2. Cleaning system according to claim 1, characterized in,

   a) that the docking interface (14) has a seal (14) which seals off the nozzle region of the nozzle applicator (1) in a fluid-tight and optionally also pressure-tight manner in the docked state, in order to be able to flush the rinsing agent into the nozzle applicator (1) through the application nozzles (4) counter to the normal application direction,

   b) that the seal (14) is optionally annular and surrounds the nozzle region with the application nozzles (4),

   c) that, in the docked state, the cleaning device (2) and the nozzle applicator (1) optionally enclose between them a flushing-in space (15) which is sealed off from the environment by the seal (14).
3. Cleaning system according to one of the preceding claims, characterized in

   a) that the rinsing agent supply (11, 12) of the cleaning device (2) comprises at least one rinsing agent valve (V_RSE, PL_RSE), namely

   a1) a compressed air valve (PL_RSE) which controls a compressed air flow through an air supply (12) of the cleaning device (2), and

   a2) a rinsing agent valve (V_RSE), which controls a rinsing agent flow through a rinsing agent feed (11) of the cleaning device (2),

   b) that the cleaning device (2) has a return system (13) for discharging residues of the coating agent, and

   c) that a return valve (RF_RSE) is arranged in the return system (13) of the cleaning device (2), which valve controls a material flow into the return system (13) of the cleaning device (2),

   d) that the return system (13) and the rinsing agent supply (11, 12) of the cleaning device (2) preferably open into the flushing-in space (15) between the cleaning device (2) and the nozzle applicator (1).
4. Cleaning system according to one of the preceding claims, characterized in

   a) that the nozzle applicator (1) is part of the cleaning system and comprises at least one rinsing agent supply (7, 8) with at least one rinsing agent valve (V, PL, FGV), namely

   a1) a compressed air supply (8) with a compressed air valve (PL) which controls a compressed air flow through the compressed air supply (8) of the cleaning device (2), and

   a2) a rinsing agent supply (7) with a rinsing agent valve (V) which controls a rinsing agent flow through a rinsing agent supply (7) of the cleaning device (2), and

   a3) a release valve (FGV) which is connected on the input side to the compressed air valve (PL) and the rinsing agent valve (V),

   b) that the nozzle applicator (1) has a return system (9) for discharging residues of the coating agent,

   c) that a return valve (RF) is arranged in the return system (9) of the nozzle applicator (1), which return valve (RF) controls the material flow into the return system (9) of the nozzle applicator (1), and/or

   d) that the nozzle applicator (1) has at least one main valve (HV) which controls the coating agent delivery.
5. Cleaning system according to claim 3 and claim 4, characterized in that the control unit (23) controls the following valves:

   a) the at least one rinsing agent valve (V_RSE, PL_RSE) of the cleaning device (2), namely

   a1) the compressed air valve (PL_RSE) of the cleaning device (2) and

   a2) the rinsing agent valve (V_RSE) of the cleaning device (2), and

   b) the return valve (RF_RSE) of the cleaning device (2),

   c) the at least one rinsing agent valve (V, PL, FGV) of the nozzle applicator (1), in particular

   c1) the compressed air valve (PL) of the nozzle applicator (1)

   c2) the rinsing agent valve (V) of the nozzle applicator (1), and

   c3) the release valve (FGV) of the nozzle applicator (1),

   d) the return valve (RF) of the nozzle applicator (1), and

   e) the main valve (HV) of the nozzle applicator (1).
6. Cleaning system according to claim 5, characterized in that the control unit in a first cleaning mode controls the valves as follows (Fig. 6A, 6B), wherein the nozzle applicator (1) is docked to the docking interface (14) of the cleaning device (2) so that compressed air and rinsing agent from the cleaning device (2) are flushed into the nozzle applicator (1) through the application nozzles (4) against the normal application direction and leave the nozzle applicator (1) again through the return (9) of the nozzle applicator (1):

   a) the rinsing agent valve (V_RSE) of the cleaning device (2) is opened continuously or pulsatingly,

   b) the compressed air valve (PL_RSE) of the cleaning device (2) is opened continuously or pulsatingly,

   c) the return valve (RF_RSE) of the cleaning device (2) is closed,

   d) the rinsing agent valve (V) of the nozzle applicator (1) is closed,

   e) the compressed air valve (PL) of the nozzle applicator (1) is closed,

   f) the return valve (RF) of the nozzle applicator (1) is opened.
7. Cleaning system according to any one of claims 5 to 6, characterized in that the control unit in a second cleaning mode controls the valves as follows (Figs. 7A, 7B), wherein the nozzle applicator (1) is docked to the docking interface of the cleaning device (2), so that compressed air and rinsing agent from the nozzle applicator (1) are flushed out of the nozzle applicator (1) into the cleaning device (2) in the normal application direction through the application nozzles (4) and leave the cleaning device (2) again through the return system (13) of the cleaning device (2):

   a) the rinsing agent valve (V_RSE) of the cleaning device (2) is closed,

   b) the compressed air valve (PL_RSE) of the cleaning device (2) is closed,

   c) the return valve (RF_RSE) of the cleaning device (2) is opened,

   d) the rinsing agent valve (V) of the nozzle applicator (1) is opened continuously or pulsatingly,

   e) the compressed air valve (PL) of the nozzle applicator (1) is opened continuously or pulsatingly,

   f) the return valve (RF) of the nozzle applicator (1) is closed.
8. Cleaning system according to any one of claims 5 to 7, characterized in that in a third cleaning mode the control unit controls the valves as follows (Fig. 8A, 8B), wherein the nozzle applicator (1) is docked to the docking interface of the cleaning device (2) so that compressed air and rinsing agent enter the nozzle applicator (1) and leave the nozzle applicator (1) again through the return (9) of the nozzle applicator (1):

   a) the rinsing agent valve (V_RSE) of the cleaning device (2) is closed,

   b) the compressed air valve (PL_RSE) of the cleaning device (2) is closed,

   c) the return valve (RF_RSE) of the cleaning device (2) is closed,

   d) the rinsing agent valve (V) of the nozzle applicator (1) is opened continuously or pulsatingly,

   e) the compressed air valve (PL) of the nozzle applicator (1) is opened continuously or pulsatingly,

   f) the return valve (RF) of the nozzle applicator (1) is opened.
9. Cleaning system according to one of the claims 5 to 8, characterized in that the control unit in a fourth cleaning mode controls the valves as follows (Fig. 9A, 9B), wherein the nozzle applicator (1) is docked to the docking interface of the cleaning device (2), so that compressed air and rinsing agent enter the cleaning device (2) and leave the cleaning device (2) again through the return system (13) of the cleaning device (2):

   a) the rinsing agent valve (V_RSE) of the cleaning device (2) is opened continuously or pulsatingly,

   b) the compressed air valve (PL_RSE) of the cleaning device (2) is opened continuously or pulsatingly,

   c) the return valve (RF_RSE) of the cleaning device (2) is opened,

   d) the rinsing agent valve (V) of the nozzle applicator (1) is closed,

   e) the compressed air valve (PL) of the nozzle applicator (1) is closed,

   f) the return valve (RF) of the nozzle applicator (1) is closed.
10. Cleaning system according to any of claims 5 to 9, characterized in that in a fifth cleaning mode the control unit controls the valves as follows (Figs. 10A, 10B), wherein the nozzle applicator (1) is docked to the docking interface of the cleaning device (2) so that compressed air enters the cleaning device (2), flows through the application nozzles (4) of the nozzle applicator (1) against the normal application direction and leaves the nozzle applicator (1) again through the return (9) of the nozzle applicator (1):

    a) the rinsing agent valve (V_RSE) of the cleaning device (2) is closed,

    b) the compressed air valve (PL_RSE) of the cleaning device (2) is opened continuously or in pulses,

    c) the return valve (RF_RSE) of the cleaning device (2) is closed,

    d) the rinsing agent valve (V) of the nozzle applicator (1) is closed,

    e) the compressed air valve (PL) of the nozzle applicator (1) is closed,

    f) the return valve (RF) of the nozzle applicator (1) is opened.
11. Cleaning system according to one of the claims 5 to 10, characterized in that the control unit in a sixth cleaning mode controls the valves as follows (Fig. 11A, 11B), wherein the nozzle applicator (1) is undocked from the docking interface of the cleaning device (2) so that compressed air enters the cleaning device (2) and leaves the cleaning device (2) again through the docking interface (14) and dries outer surfaces of the nozzle applicator (1):

    a) the rinsing agent valve (V_RSE) of the cleaning device (2) is closed,

    b) the compressed air valve (PL_RSE) of the cleaning device (2) is opened continuously or in pulses,

    c) the return valve (RF_RSE) of the cleaning device (2) is closed,

    d) the rinsing agent valve (V) of the nozzle applicator (1) is closed,

    e) the compressed air valve (PL) of the nozzle applicator (1) is closed,

    f) the return valve (RF) of the nozzle applicator (1) is closed.
12. Cleaning system according to any one of claims 5 to 11, characterized in

    a) that the control unit (23) switches between at least two of the cleaning modes, and

    b) that the control unit (23) switches between the first cleaning mode (Fig. 6A, 6B) with a rinsing of the application nozzles (4) against the normal application direction and the second cleaning mode (Fig. 7A, 7B) with a rinsing of the application nozzles (4) in the normal application direction, and

    c) that the control unit (23) activates a sequence of the different cleaning modes during a cleaning process, in particular in the following sequence:

    c1) first cleaning mode,

    c2) second cleaning mode,

    c3) optionally third cleaning mode,

    c4) optional fourth cleaning mode,

    c5) optional fifth cleaning mode,

    c6) optional sixth cleaning mode,
13. Cleaning system according to one of the preceding claims, characterized in

    a) that the nozzle applicator (1) does not emit a spray mist of the coating agent, but a spatially narrowly limited coating agent jet (18), in particular with a jet widening angle of less than 10°, 5° or 2°,

    b) that the coating agent jet (18) consists of individual coating agent drops or a sequence of coating agent drops or is continuous in the longitudinal direction of the jet,

    c) that the nozzle applicator (1) operates essentially without overspray, in particular with an application efficiency of more than 80%, 90% or 95%,

    d) that the nozzle applicator (1) is a print head,

    e) that the rinsing agent, the pulse air, the rinsing agent have an operating pressure of at least 4bar, 5bar, 6bar, 7bar, 8bar, 9bar or 10bar in the cleaning mode,

    f) that the nozzle applicator (1) has more than 5, 10, 20, 30 or 50 application nozzles (4).
14. Cleaning system according to any of the preceding claims, characterized in,

    a) that the control unit (23) controls the jet checking device (17) for checking the coating agent jets emitted by the application nozzles (4),

    b) that the control unit (23) then controls the cleaning device (2) for cleaning the application nozzles (4), the cleaning being optionally restricted to those application nozzles (4) in which the jet checking device (17) has detected clogging,

    c) that the control unit (23) optionally controls the jet checking device (17) again thereafter for checking the coating agent jets emitted by the application nozzles (4).