EP2337688B2 - Coating device and associated coating method - Google Patents

Description

The invention relates to a coating device for coating, in particular painting, motor vehicle body components. Furthermore, the invention relates to a corresponding coating method.

Figure 1 shows a cross-sectional view through a conventional painting system for painting motor vehicle body components. The motor vehicle body components to be painted are transported on a conveyor 1 at right angles to the plane of the drawing through a paint booth 2, in which the motor vehicle body components are then painted in a conventional manner by painting robots 3, 4. The painting robots 3, 4 have several pivoting robot arms and each guide an application device, such as a rotary atomizer, an air atomizer, or a so-called airless device, via a multi-axis robot wrist axis.

A disadvantage of these known application devices, however, is the suboptimal application efficiency, so that a portion of the sprayed paint, referred to as overspray, does not land on the vehicle body component to be painted and must be removed with the booth air from the paint booth 2. Above the paint booth 2 there is therefore a so-called plenum 5, from which air is introduced downwards through a ceiling 6 of the paint booth 2 in the direction of the arrow into the paint booth 2. The booth air then flows downwards from the paint booth 2, along with the overspray it contains, into a washout 7 located below the paint booth 2, where the overspray is removed from the booth air and bound to water.

This wastewater, with the overspray it contains, must then be treated again in a complex process, whereby the resulting paint sludge is hazardous waste and must be disposed of accordingly at great expense.

In addition, the air sinking speed in the paint booth 2 must be at least in the range of approx. 0.3-0.5 m/s in order to quickly remove the overspray generated during painting from the paint booth 2.

Furthermore, the overspray produced during painting can temporarily and locally create an explosive atmosphere, so that the relevant statutory ATEX product guidelines (ATEX: Atmosphere explosible ) must be observed.

On the one hand, the known application devices cause high investment costs for the necessary washout and the necessary explosion protection due to their unsatisfactory application efficiency and the resulting overspray.

On the other hand, the known application devices are also associated with high operating costs due to the overspray generated during operation due to paint losses and the disposal costs for the overspray.

The invention is therefore based on the object of creating a corresponding improvement.

Out of JP 2008-246713 A An inkjet printer with a print head is known, which in one embodiment contains two parallel rows, each with multiple nozzles. In another embodiment, the print head contains four parallel rows of nozzles, each of which injects one of four different primary colors. This and other known inkjet printers are not suitable for applying paint to body components. EP 1 884 365 A1 discloses an application head for applying paint to an object surface, the application head comprising at least one fluid supply channel and at least one nozzle outlet for paint. The at least one nozzle is arranged in groups or arrays, each of which has means for generating a pressure pulse in the paint such that a small amount of paint is ejected from the at least one nozzle. The speed and timing of the paint ejection can be controlled separately for each of the plurality of nozzles in the application head.

The above-mentioned object is achieved by a coating device according to the invention and a corresponding coating method according to the independent claims.

The invention encompasses the general technical teaching of using an application device with such a high application efficiency that a washout, which is conventionally used to wash out the overspray from the booth air, can be dispensed with. One advantage of the coating device according to the invention, in the preferred embodiment, is that a separate washout is dispensed with. However, the invention is not limited to painting systems that have no washout at all. Rather, the use of application devices with a higher application efficiency makes it possible to reduce the dimensions of the washout if complete dispensing is not possible.

The application device can be a bubble jet printhead or a piezo printhead. However, with regard to the technical principle of the printhead used, the invention is not limited to bubble jet printheads and piezo printheads, but can also be implemented with other ejection mechanisms.

Furthermore, within the scope of the invention, it is possible for the print head to eject the coating agent pneumatically. For example, the individual coating agent drops can be ejected by short air pulses, which accelerate the coating agent drops toward the component to be coated, thereby increasing the coating distance.

It should also be noted that the print head can eject the coating agent either in individual coating agent droplets or continuously. Furthermore, within the scope of the invention, it is possible for some of the coating agent nozzles of the print head to eject the coating agent continuously, while another part of the coating agent nozzles of the print head ejects the coating agent in individual coating agent droplets.

According to the invention, the print head is positioned by a multi-axis robot, the robot having a plurality of pivotable robot arms and a multi-axis robot hand axis on which the print head is mounted.

In contrast to conventional print heads used, for example, in inkjet printers, the print head in the coating device according to the invention has a significantly larger area coating capacity, which is greater than 1 m ² /min. and preferably greater than 2 m ² /min., 3 m ² /min., or 4 m ² /min.

In contrast to conventional inkjet printers, the printhead of the coating device according to the invention must also be capable of applying liquid coatings containing solid coating components, such as pigments and so-called metallic flakes (mica). The individual coating nozzles of the printhead are therefore sized to match the solid coating components, so that the printhead can also apply coatings containing the solid coating components.

In the coating device according to the invention, the application device is preferably arranged in a paint booth in which the components are coated with the coating agent. Such paint booths are known from the prior art and therefore need not be described in detail.

However, it has already been mentioned above that the print heads used as application devices within the scope of the invention have a significantly higher application efficiency than conventional application devices, such as rotary atomizers. The washout located below the paint booth can therefore be dimensioned much smaller than in conventional painting systems with rotary atomizers as application devices. In one embodiment of the invention, the high application efficiency of the print heads used as application devices even makes it possible to completely dispense with washout or other complex filter measures, such as dry separation or similar, below the paint booth. In this case, simple filters that are replaced or cleaned cyclically (e.g., weekly, monthly, semi-annually, or annually) are sufficient.

Furthermore, the high application efficiency of the print heads used as application devices within the scope of the invention eliminates the need for explosion protection measures according to the relevant statutory ATEX guidelines, as less overspray is generated and therefore no potentially explosive atmosphere is created during operation. In one embodiment of the invention, therefore, no explosion protection is provided in the paint booth.

However, the coating device according to the invention also preferably provides an air extraction system that extracts the booth air from the paint booth, with the extraction preferably taking place downwards. The booth air is preferably extracted through an air filter that filters the overspray from the booth air. The air filter can be designed, for example, as a filter ceiling arranged on the floor of the paint booth, so that the booth air is extracted downwards from the paint booth through the filter ceiling.

Due to the higher application efficiency of the print heads used as application devices in the invention and the lower overspray, the air settling velocity in the paint booth can be lower than in conventional paint systems that use, for example, rotary atomizers as application devices. In the paint system according to the invention, the air settling velocity in the paint booth can therefore be less than 0.5 m/s, 0.4 m/s, 0.3 m/s, 0.2 m/s, or 0.1 m/s.

At least one color changer is assigned to the print head, which is connected to the print head on the output side and is preferably supplied with different coating agents on the input side, so that the color changer selects one of the coating agents and feeds the print head with the selected coating agent.

In addition, the color changer can be supplied with various effect paints on the input side, such as special paints, metallic paints or mica paints.

In one embodiment of the invention, the color changer feeds a group of several coating agent nozzles with the same coating agent on the output side, wherein the coating agent nozzles can be arranged, for example, in a row, for example in a line or a column.

Furthermore, it is possible for a color mixer to be arranged upstream of the color changer on the input side, which is supplied with different colored coating agents in the primary colors of a color system (e.g., CMYK color system). The color mixer can then mix a desired color from the various primary colors of the respective color system and feed it to the color changer for selection. Furthermore, in this embodiment, the color changer is preferably supplied with at least one effect paint, for example, a mica paint, a metallic paint, and/or a special paint. The color changer can then either select the color mixed by the color mixer or access one of the effect paints.

As already mentioned above, the coating nozzles in the print head can be arranged in rows, for example, in rows and columns. Preferably, the coating nozzles are arranged in the print head in a matrix.

Within the scope of the invention, it is possible for each of the individual coating agent rows to be assigned a basic color (e.g. cyan, magenta, yellow, black) so that the coating agent nozzles of a row apply the same color.

Within the scope of the invention it is provided that all coating agent nozzles of the print head, or at least a large part of them, are connected to a single coating agent supply line and therefore apply the same coating agent.

Alternatively, within the scope of the invention, it is possible for some of the coating agent nozzles of the print head to be connected to a first coating agent supply line, while a second part of the coating agent nozzles of the print head is connected to a second coating agent supply line, so that the print head can apply two different coating agents. Preferably, the coating agent nozzles in the individual nozzle rows (rows or columns) are alternately connected to one coating agent supply line or to the other coating agent supply line.

In one embodiment of the invention, the print head has at least one separate coating nozzle that applies only effect paint containing effect particles. Furthermore, the print head preferably has at least one additional coating nozzle that applies normal paint that does not contain effect particles. The various coating nozzles can then be adapted accordingly.

It is also conceivable that, in the color mixing processes described above, the effect particles (e.g., metallic, mica, etc.) are applied to the object using a separate coating nozzle. This allows effects to be applied to the object in a very targeted manner and with local variations. In some cases, effects can also be created that are unimaginable today. With the new inkjet technology, it is possible to place the effect particles, for example, only on the surface of the layer.

Furthermore, a major advantage of the invention is that the solution according to the invention makes it possible for the first time to coat an entire body with sufficient surface coverage, but also to print specific details and graphics.

It has already been mentioned above that the coating nozzles in the print head are preferably arranged in a matrix in several rows and columns. In one variant of the invention, the individual coating nozzles of the print head are essentially the same size. The adjacent nozzle rows can be offset from one another in the longitudinal direction, in particular by half a nozzle width, which enables maximum packing density of the coating nozzles in the nozzle head. Furthermore, the individual nozzle rows are preferably aligned transversely, in particular at right angles to the feed direction of the nozzle head.

According to the invention, the print head has nozzle openings of different sizes. For example, rows of nozzles with large coating nozzles and rows of nozzles with small coating nozzles can be arranged alternately in the print head. Here, too, it may be useful to arrange the rows with the larger coating nozzles offset relative to one another, in particular by half the nozzle width.

According to the invention, the print head is rotatably mounted and rotates during the coating process. The print head has coating nozzles of different sizes. The smaller coating nozzles can preferably be arranged closer to the rotational axis of the print head than the larger coating nozzles.

In another variant of the invention, several print heads are provided, which are jointly guided by the multi-axis robot and can be pivoted relative to each other, which enables adaptation to curved component surfaces.

It has already been mentioned above that a special varnish, a metallic varnish or a mica varnish can be used as an effect varnish.

Furthermore, it may be advantageous to at least partially cover the surface areas of the print head that come into contact with the coating agent (e.g., lines) with a wear-reducing coating, such as a DLC coating (DLC: Diamond-like Carbon), a diamond coating, a hard metal, or a material combination of a hard and a soft material. Furthermore, the surface areas of the print head that come into contact with the coating agent can be coated with titanium nitride, titanium oxide, or chemical nickel, or with another layer produced using the PVC process ( P hysical V apour Deposition ), the CVD process ( C hemical V apour Deposition), or the anodizing process (Anodizing: Electrolytic Oxidation of Aluminum ), or with an easy-to-clean coating.

Furthermore, electrostatic coating agent charging and/or compressed air support can be provided to improve the application efficiency of the print head.

Another possibility is position detection, which detects the spatial position of the print head and/or the component surface to be coated and controls or regulates the positioning of the print head accordingly.

Currently, there are also efforts to mix automotive paints directly in the paint shops from 6-10 base pastes. For this purpose, the pastes are mixed in the conventional way in mixing stations, and the colors are adjusted. All paints used in the automotive industry (solid, metallic, mica, or special-effect paints) can be produced from these pastes. It is conceivable that these pastes could be mixed directly in the atomizer or an upstream device. This has the advantage that only the required amount is provided fully automatically, directly before or during application. The dosing of the individual components can be carried out using the well-known Dosing techniques (pressure regulators, dosing pumps, gear measuring cells, flow measuring cells, piston dosing devices, etc.) can be used. The "mixing chamber" can be a mixing chamber, a piece of hose, or a mixing system (e.g., a Keenix mixer). The challenge is the very precise dosing of the individual components to achieve the exact color shade. Therefore, a color sensor for controlling the dosing unit can be useful.

However, inkjet technology can also be used as a dosing technique. The required amount can be generated from individual droplets, which depend on the nozzle opening time and the pressure. These inkjet nozzles then mix the color in a mixing chamber.

Furthermore, within the scope of the invention, it is possible to provide a sensor which detects the course of a guide track in order to position the print head in relation to the guide track.

In a preferred embodiment, the sensor is attached to the print head or to the robot, but other designs are also possible. For example, the sensor can detect the previous coating path, so that the current coating path can be applied at a specific relative position to the previous coating path. For example, it is generally desirable for the current coating path to be applied at a specific distance parallel to the previous coating path, which is possible thanks to the sensor detection described above.

In the preferred embodiment, the sensor is an optical sensor, but other types of sensors are also possible.

The above-mentioned guide track may also be a separate track applied solely for guidance purposes and may, for example, comprise a normally invisible color that is only visible to the sensor when illuminated with ultraviolet (UV) or infrared (IR) light.

In this context, it is also possible to use a laser measuring system, as is known from the state of the art. Such a laser measuring system can also measure the distance to the surface of the component to be coated and maintain it constant within the framework of a closed-loop control system.

In this variant of the invention, a robot controller is provided which is connected to the sensor on the input side and to the robot on the output side, wherein the robot controller positions the print head depending on the course of the guideway.

In one variant of the invention, the print head has a sheath flow nozzle that emits a sheath flow of air or another gas. The sheath flow surrounds the coating agent stream emitted from the coating agent nozzle to atomize or confine the coating agent droplets. Furthermore, this sheath flow can direct the resulting overspray onto the component surface in the form of an air curtain, thereby improving application efficiency.

In one embodiment of the invention, the print head has a plurality of coating agent nozzles arranged side by side with respect to the web direction, with the outer coating agent nozzles dispensing less coating agent than the inner coating agent nozzles, resulting in a layer thickness corresponding to the pitch transverse to the web direction. Nozzles do not necessarily have to be arranged in a row. The amount of ink can be controlled for each nozzle and each pixel. Different amounts of ink can also control the color intensity, for example. In this case, it is possible for the layer thickness distribution to be a Gaussian normal distribution. Alternatively, it is possible for the amount of coating agent dispensed by the individual coating agent nozzles to be selected such that the layer thickness distribution is trapezoidal. Such a trapezoidal layer thickness distribution is advantageous because the adjacent coating agent webs can overlap one another in such a way that the superposition of the trapezoidal layer thickness distributions of the adjacent coating agent webs results in a constant layer thickness.

In another embodiment of the invention, the components to be coated are conveyed along a conveyor path, which is known per se from the prior art of painting systems and therefore does not need to be described in detail. In this embodiment, a gantry spans the conveyor path, with numerous print heads mounted on the gantry, which are directed at the components on the conveyor path and coat these components.

Finally, the invention also includes a corresponding coating method, as is already apparent from the above description.

The technology according to the invention can also be used for the targeted coating of cut edges of pre-coated sheets, punched blanks or for the efficient sealing of seams and edges

Figur 1

eine Querschnittsansicht durch eine herkömmliche Lackieranlage zur Lackierung von Kraftfahrzeugkarosseriebauteilen,

Figur 2

eine Querschnittsansicht durch eine erfindungsgemäße Lackieranlage zur Lackierung von Kraftfahrzeugkarosseriebauteilen mit Druckköpfen als Applikationsgeräte,

Figur 3A

eine Düse des Druckkopfs mit einem Farbwechsler und der zugehörigen Beschichtungsmittelversorgung,

Figur 3B

eine Düsenreihe des Druckkopfs mit mehreren Beschichtungsmitteldüsen und jeweils individuell zugeordneten Farbwechslern,

Figur 4A

eine Düsenreihe mit mehreren Beschichtungsmitteldüsen und einem zugeordneten Farbwechsler

Figur 4B

eine Abwandlung von Figur 4A, wobei der Farbwechsler eingangsseitig nur eine einzige Sonderfarbversorgung aufweist,

Figur 5

eine Abwandlung von Figur 4A, wobei der Farbwechsler eingangsseitig mit einem Farbmischer verbunden ist, der mit den Grundfarben eines Farbsystems versorgt wird,

Figur 6

eine Düsenreihe des Druckkopfs mit mehreren Beschichtungsmitteldüsen, wobei vier der Beschichtungsmitteldüsen jeweils mit einer Grundfarbe eines CMYK-Farbsystems gespeist werden, während die fünfte Beschichtungsmitteldüse von einem Farbwechsler mit einem Effektlack gespeist wird,

Figur 7

mehrere Düsenreihen des Drucckopfs, denen jeweils eine Grundfarbe eines CMYK-Farbsystems zugeordnet ist,

Figur 8

mehrere Düsenreihen des Drucckopfs, denen jeweils ein Farbwechsler und jeweils eine Grundfarbe eines CMYK-Farbsystems zugeordnet ist,

Figur 9

mehrere Düsenreihen des Drucckopfs, denen jeweils eine Grundfarbe eines CMYK-Farbsystems und ein Farbwechsler zugeordnet ist, wobei die Düsenreihen alternativ über einen weiteren Farbwechsler mit einem Effektlack versorgt werden können,

Figur 10

eine Düsenreihe des Druckkopfs, wobei vier benachbarte Beschichtungsmitteldüsen über einen Farbmischer mit einem gemischten Farbton versorgt werden, während die fünfte Beschichtungsmitteldüse über einen Farbwechsler einem Effektlack versorgt wird,

Figur 11

mehrere Düsenreihen des Drucckopfs, die gemeinsam über einen Farbmischer mit einem Mischfarbton versorgt werden,

Figur 12

mehrere Düsenreihen des Drucckopfs mit jeweils einem Farbwechsler, wobei die Farbwechsler der einzelnen Düsenreihen über einen Farbmischer mit einem Farbmischton versorgt werden,

Figur 13

mehrere Düsenreihen des Drucckopfs, die gemeinsam über einen Farbwechsler und einen Farbmischer mit dem zu applizierenden Beschichtungsmittel versorgt werden,

Figur 14

mehrere Düsenreihen des Drucckopfs, die gemeinsam über eine einzige Beschichtungsmittelzuleitung versorgt werden,

Figur 15

mehrere Düsenreihen des Drucckopfs, wobei die einzelnen Düsen innerhalb der Düsenreihen abwechselnd mit einer ersten Beschichtungsmittelzuleitung und einer zweiten Beschichtungsmittelzuleitung verbunden sind,

Figur 16

eine Düsenanordnung in einem Druckkopf,

Figur 17

eine alternative Düsenanordnung in dem Druckkopf mit kleineren Beschichtungsmitteldüsen,

Figur 18

eine alternative Anordnung der Beschichtungsmitteldüsen in dem Druckkopf, wobei die Beschichtungsmitteldüsen unterschiedliche Düsengrößen aufweisen,

Figur 19

eine Abwandlung von Figur 18, wobei die Düsenreihen mit den größeren Beschichtungsmitteldüsen versetzt zueinander angeordnet sind,

Figur 20

ein Schema zur Verdeutlichung der Lackierung einer scharfen Kante mit dem erfindungsgemäßen Druck- kopf,

Figur 21

einen rotierenden Druckkopf,

Figur 22

eine Druckkopfanordnung mit mehreren verschwenkbaren Druckköpfen zur Anpassung an gekrümmte Bauteiloberflächen,

Figur 23

ein schichtförmig aufgebautes Pixel mit mehreren Schichten in den Grundfarben eines Farbsystems und einer obersten Schicht aus einem Metalliclack,

Figur 24

eine schematische Darstellung einer erfindungsgemäßen Beschichtungseinrichtung mit einem mehrachsigen Roboter, der einen Drucckopf und einen Sensor führt, um den Druckkopf zu positionieren,

Figur 25

eine schematische Darstellung einer erfindungsgemäßen Beschichtungseinrichtung, bei der mehrere Komponenten zu einem Gemisch zusammengemischt werden, wobei der Druckkopf dann das Gemisch appliziert,

Figur 26

eine schematische Darstellung eines erfindungsgemäßen Drucckopfs, der mehrere Komponenten unabhängig voneinander appliziert, wobei die Mischung auf der Bauteiloberfläche erfolgt,

Figur 27

eine schematische Darstellung eines erfindungsgemäßen Druckkopfs mit einer Hüllstromdüse,

Figur 28

eine schematische Darstellung eines erfindungsgemäßen Drucckopfs, bei dem die Beschichtungsmitteltropfen pneumatisch ausgestoßen und beschleunigt werden,

Figur 29

eine schematische Darstellung eins Druckkopfs, der eine trapezförmige Schichtdickenverteilung erzeugt,

Figur 30

eine schematische Darstellung einer erfindungsgemäßen Beschichtungseinrichtung, bei der zahlreiche Druckköpfe an einem Portal angebracht sind,

Figur 31 und 32

Abwandlungen der Figuren 18 und 19 mit einer maximalen Packungsdichte der einzelnen Düsen.

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

Figure 1

a cross-sectional view through a conventional painting system for painting motor vehicle body components,

Figure 2

a cross-sectional view through a painting system according to the invention for painting motor vehicle body components with print heads as application devices,

Figure 3A

a nozzle of the print head with a color changer and the associated coating agent supply,

Figure 3B

a row of nozzles of the print head with several coating agent nozzles and individually assigned color changers,

Figure 4A

a nozzle row with several coating agent nozzles and an associated color changer

Figure 4B

a variation of Figure 4A , whereby the color changer has only a single special color supply on the input side,

Figure 5

a variation of Figure 4A , where the color changer is connected on the input side to a color mixer which is supplied with the basic colors of a color system,

Figure 6

a nozzle row of the print head with several coating nozzles, where four of the coating nozzles are each fed with a basic color of a CMYK color system, while the fifth coating nozzle is fed with an effect varnish by a color changer,

Figure 7

several rows of nozzles of the print head, each of which is assigned a basic color of a CMYK color system,

Figure 8

several rows of nozzles of the print head, each of which is assigned a color changer and a basic color of a CMYK color system,

Figure 9

several rows of nozzles of the print head, each of which is assigned a basic color of a CMYK color system and a color changer, whereby the rows of nozzles can alternatively be supplied with an effect varnish via another color changer,

Figure 10

a row of nozzles of the print head, whereby four adjacent coating nozzles are supplied with a mixed color via a color mixer, while the fifth coating nozzle is supplied with an effect varnish via a color changer,

Figure 11

several rows of nozzles of the print head, which are jointly supplied with a mixed color via a color mixer,

Figure 12

several rows of nozzles of the print head, each with a color changer, whereby the color changers of the individual rows of nozzles are supplied with a color mixing tone via a color mixer,

Figure 13

several rows of nozzles of the print head, which are jointly supplied with the coating agent to be applied via a color changer and a color mixer,

Figure 14

several rows of nozzles of the print head, which are supplied together via a single coating agent supply line,

Figure 15

several rows of nozzles of the print head, wherein the individual nozzles within the rows of nozzles are alternately connected to a first coating agent supply line and a second coating agent supply line,

Figure 16

a nozzle arrangement in a print head,

Figure 17

an alternative nozzle arrangement in the print head with smaller coating agent nozzles,

Figure 18

an alternative arrangement of the coating agent nozzles in the print head, wherein the coating agent nozzles have different nozzle sizes,

Figure 19

a variation of Figure 18 , whereby the nozzle rows with the larger coating agent nozzles are arranged offset from each other,

Figure 20

a diagram to illustrate the varnishing of a sharp edge with the printing process according to the invention head,

Figure 21

a rotating print head,

Figure 22

a print head arrangement with several pivoting print heads for adaptation to curved component surfaces,

Figure 23

a layered pixel with several layers in the primary colors of a color system and a top layer of a metallic paint,

Figure 24

a schematic representation of a coating device according to the invention with a multi-axis robot that guides a print head and a sensor to position the print head,

Figure 25

a schematic representation of a coating device according to the invention, in which several components are mixed together to form a mixture, the print head then applying the mixture,

Figure 26

a schematic representation of a printing head according to the invention, which applies several components independently of one another, whereby the mixing takes place on the component surface,

Figure 27

a schematic representation of a print head according to the invention with a sheath flow nozzle,

Figure 28

a schematic representation of a printing head according to the invention, in which the coating agent drops are ejected and accelerated pneumatically,

Figure 29

a schematic representation of a print head that produces a trapezoidal layer thickness distribution,

Figure 30

a schematic representation of a coating device according to the invention, in which numerous print heads are attached to a portal,

Figures 31 and 32

Variations of the Figures 18 and 19 with a maximum packing density of the individual nozzles.

The cross-sectional view in Figure 2 shows a painting system according to the invention, which is partly identical to the one described at the beginning and in Figure 1 shown conventional painting system, so that to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of the painting system according to the invention is that the painting robots 3, 4 do not use rotary atomizers as application devices, but rather print heads 8, 9, which have a significantly higher application efficiency of more than 95% and therefore generate significantly less overspray.

On the one hand, this offers the advantage that the conventional painting system according to Figure 1 existing leaching 7 can be dispensed with.

Instead, in the painting system according to the invention, an air extraction system 10 is located below the painting booth 2, which extracts the booth air downwards from the painting booth 2 through a filter ceiling 11. The filter ceiling 11 filters out the slight overspray present in the booth air without the need for the washout system 7 as in the conventional painting system.

In this embodiment, the print heads 8, 9 operate like conventional print heads according to the piezo principle, but the surface coating performance of the print heads 8, 9 is significantly greater compared to conventional print heads so that the motor vehicle body components can be painted at a satisfactory working speed.

Figure 3A shows a coating agent nozzle 12, which is arranged in each of the print heads 8, 9 alongside numerous other coating agent nozzles, wherein the coating agent nozzle 12 is supplied with the coating agent to be applied by a color changer 13. On the input side, the color changer 13 is connected to a total of seven coating agent supply lines, from which the color changer 13 can select one to supply the coating agent to the coating agent nozzle 12. Four coating agent supply lines of the color changer 13 are used to supply different colored coating agents in the primary colors C (cyan), M (magenta), Y (yellow), and K (key = black). The other three coating agent supply lines of the color changer 13, in contrast, are used to supply a metallic paint, a mica paint, and a special paint.

In this embodiment, the desired color shade of the coating agent is mixed on the motor vehicle body component to be coated, whereby either a temporal or a spatial mixing is possible.

In the case of temporal mixing, for example, droplets of coating agent in the basic colours C, M, Y and K are applied one after the other in the desired colour ratio, so that the droplets of coating agent then mix on the motor vehicle body component to be coated.

In the case of local mixing, however, 12 coating agent droplets of a specific base color C, M, Y or K are applied from the coating agent nozzle, which then mix on the vehicle body components to be coated with other coating agent droplets that are applied from another coating agent nozzle (not shown here).

Figure 3B shows a modification of the embodiment according to Figure 3A , showing a nozzle row with four coating agent nozzles 14.1-14.4 and four color changers 15.1-15.4.

The color changers 15.1-15.4 are jointly connected to five coating agent supply lines, via which the color changers 15.1-15.4 are supplied with the four basic colors C, M, Y, K of the CMYK color system and additionally with a special coating S.

Figure 4A shows a group of coating agent nozzles 16.1-16.5, which are jointly connected to the output of a color changer 17 and therefore apply the same coating agent during operation.

The color changer 17 is connected on the input side to seven coating agent supply lines, four of which supply the basic colors C, M, Y, K of the CMYK color system, while the other three coating agent supply lines supply a metallic paint, a mica paint, or a special paint.

The embodiment according to Figure 4B largely agrees with the above-described and in Figure 4A illustrated embodiment, so that to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the color changer 17 is connected on the output side to a total of six coating agent nozzles 16.1-16.6, which thus apply the same coating agent.

A further special feature of this embodiment is that the color changer 17 is connected on the input side to only five coating agent supply lines, whereby four of the coating agent supply lines supply the basic colors C, M, Y, K of the CMYK color system, whereas the fifth coating agent supply line supplies a special paint.

The embodiment according to Figure 5 partly corresponds to the embodiment according to Figure 4A so that, to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the color changer 17 is connected on the input side to a color mixer 18. The color mixer 18 is connected on the input side to four coating agent supply lines that supply the four primary colors C, M, Y, and K of the CMYK color system. The color mixer 18 can thus mix any desired color from the four primary colors C, M, Y, and K and supply it to the color changer 17.

Furthermore, it can be seen from the drawing that the color changer 17 can optionally supply only the coating agent nozzle 16.1 with the coating agent to be applied or optionally also the coating agent nozzles 16.2, 16.3 and possibly also other coating agent nozzles that are not shown in the drawing.

The embodiment according to Figure 6 again partially corresponds to the embodiments described above, so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the adjacent coating agent nozzles 16.1-16.4 are each directly connected to a coating agent supply line, via which one of the basic colors C, M, Y, K of the CMYK color system is supplied.

The adjacent coating agent nozzle 16.5, on the other hand, is connected via the color changer 17 to three further coating agent supply lines, which supply a metallic paint, a mica paint, or a special paint.

During operation, the color changer then selects the desired effect paint (metallic paint, mica paint, or special paint) and applies it via coating nozzle 16.5. In addition, the four primary colors C, M, Y, and K of the CMYK color system are applied in the desired ratio via coating nozzles 16.1-16.4. The primary colors C, M, Y, and K are then mixed with the selected effect paint on the component to be coated.

Figure 7 shows several nozzle rows 19.1-19.4 with numerous coating nozzles 20, with each of the four primary colors C, M, Y, and K of the CMYK color system assigned to the individual nozzle rows 19.1-19.4. Thus, the coating nozzles 20 of coating row 19.1 apply the primary color C (cyan), while the coating nozzles 20 of the coating row 19.2 apply the primary color M (magenta). The coating nozzles 20 of the nozzle row 19.3, on the other hand, apply coating of the primary color Y (yellow), while the coating nozzles 20 of the nozzle row 19.4 apply coating of the primary color K (key = black).

In addition, the nozzle rows 19.1-19.4 can also apply a special paint S. In the In the individual nozzle rows 19.1-19.4, every second coating nozzle 20 is therefore connected to a special paint supply line. In the individual nozzle rows 19.1-19.4, the individual coating nozzles 20 can thus alternately apply the special paint S and one of the four basic colors C, M, Y, K.

Figure 8 also shows four nozzle rows 21.1-21.4, each comprising numerous coating agent nozzles 22.

Furthermore, four color changers 23.1-23.4 are provided, each of which supplies all coating nozzles 22 of one of the four nozzle rows 21.1-21.4 with a coating agent. Thus, color changer 23.1 supplies all coating nozzles 22 of nozzle row 21.1, while color changer 23.2 supplies all coating nozzles 22 of nozzle row 21.2. Color changer 23.3, on the other hand, supplies all coating nozzles 22 of nozzle row 21.3, while color changer 23.4 supplies all coating nozzles 20 of nozzle row 21.4 with the coating agent to be applied.

On the input side, the color changers 23.1-23.4 are each supplied with a primary color C, M, Y, K, so that each of the primary colors C, M, Y, K is assigned to one of the four nozzle rows 21.1-21.4. Furthermore, the color changers 23.1-23.4 are connected to several special color supply lines through which special colors, metallic paints, or the like can be supplied.

With this nozzle arrangement, the paint is also mixed on the component to be coated.

The embodiment according to Figure 9 partly agrees with the above-described and in Figure 8 illustrated embodiment, so that to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the color changers 23.1-23.4 are connected on the input side to another color changer 24, whereby the color changer 24 is supplied with three different effect paints S1, S2, S3 on the input side. During operation, the color changer 24 selects one of the effect paints S1, S2, or S3 and makes the selected effect paint available to the other color changers 23.1-23.4 for selection. The color changers 23.1-23.4 can therefore optionally select the respective base color C, M, Y, or K or the effect paint provided by the color changer 24.

The embodiment according to Figure 10 partly corresponds to the embodiment according to Figure 6 so that, to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the coating nozzles 16.1-16.4 are not supplied separately with each of the primary colors C, M, Y, or K. Rather, the coating nozzles 16.1-16.4 are jointly supplied with the coating agent to be applied by a color mixer 25. The color mixer 25 is supplied on the input side with the primary colors C, M, Y, K of the CMYK color system and, according to the control, mixes a desired color tone, which is then applied by the coating nozzles 16.1-16.4.

The embodiment according to Figure 11 partly agrees with the above-described and in Figure 7 illustrated embodiment, so that to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the individual nozzle rows 19.1-19.4 are not supplied with different primary colors, but with a mixed coating agent that is mixed together by a color mixer 26 from the primary colors C, M, Y and K.

The embodiment according to Figure 12 partly agrees with the above-described and in Figure 8 illustrated embodiment, so that to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the individual color changers 23.1-23.4 are jointly supplied with a color mixture provided by a color mixer 27, the color mixer 27 being supplied with the primary colors C, M, Y and K on the input side.

Figure 13 shows a further embodiment of a nozzle arrangement in the print heads 8, 9, wherein four nozzle rows 28.1-28.4 are shown, each having numerous coating agent nozzles 29. All coating agent nozzles 29 and all coating agent rows 28.1-28.4 are jointly supplied with the same coating agent by a color changer 30.

On the input side, the color changer 30 is connected to three special color supply lines, via which three special paints S1, S2, S3 are supplied.

In addition, the color changer 30 is connected on the input side to a color mixer 31, which mixes a desired color tone from the primary colors C, M, Y, K and makes it available to the color changer 30 for selection.

The embodiment according to Figure 14 partly agrees with the above-described and in Figure 13 shown embodiment, so that to avoid repetition, the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that all coating agent nozzles 29 in all nozzle rows 28.1-28.4 are connected to a common coating agent supply line 31, via which the same coating agent is supplied.

The embodiment according to Figure 15 partly corresponds to the embodiment according to Figure 11 so that to avoid repetition, reference is made to the above description.

A special feature of this embodiment is that the coating agent nozzles 20 in the individual nozzle rows 19.1-19.4 are alternately connected to a first coating agent line 32 and a second coating agent supply line 33.

Figure 16 shows a nozzle arrangement 34 for the print heads 8, 9 of the painting system according to the invention, wherein the arrow indicates the feed direction of the print heads 8, 9, ie the printing direction.

It can be seen from the drawing that the nozzle arrangement 34 has several rows of nozzles 35.1-35.7, each of which comprises several coating agent nozzles 36.

The coating agent nozzles 36 have a uniformly large nozzle opening within the entire nozzle arrangement 34.

The adjacent nozzle rows 35.1-35.7 are arranged offset from one another in the longitudinal direction by half a nozzle width, which enables a maximum packing density of the coating agent nozzles 36 within the nozzle arrangement 34.

Figure 17 shows a modified nozzle arrangement 34 which is largely identical to that described above and in Figure 16 corresponds to the nozzle arrangement shown, so that to avoid repetition, reference is made to the above description.

A special feature of this embodiment is that the individual nozzles 36 have a significantly smaller nozzle size.

Another special feature of this embodiment is that the adjacent rows of nozzles are not offset from one another.

Figure 18 shows a further embodiment of a nozzle arrangement 37 with five parallel rows of nozzles 38.1-38.5 with relatively large nozzle openings and four rows of nozzles 39.1-39.4 with relatively small nozzle openings.

The embodiment according to Figure 19 largely corresponds to the embodiment described above according to Figure 18 so that, to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the nozzle rows 38.1-38.5 with the larger nozzle openings are offset from each other in the longitudinal direction by half a nozzle width.

Figure 20 shows a diagram for painting a sharp edge 39. This shows that the edge 39 is composed of coating agent surfaces 40, 41, 42 of different sizes, whereby the coating agent surfaces 40-42 of different sizes are produced by coating agent nozzles of correspondingly different sizes.

When printing a graphic, larger areas of a color tone are printed with the large coating nozzles, while areas requiring a certain degree of edge sharpness are refined with small coating nozzles. This process is particularly useful for two-tone paint jobs (e.g., the sill area of a car body in a contrasting color). The illustration shows an edge zone printed with sharp edges using three different nozzle sizes.

Figure 21 schematically shows a rotatable print head 43 with four large coating agent nozzles 44 and numerous smaller coating agent nozzles 45, wherein the larger coating agent nozzles 44 are arranged on the outside with respect to the axis of rotation of the print head 43, while the smaller coating agent nozzles 45 are arranged on the inside with respect to the axis of rotation of the print head 43.

Finally, Figure 22 a print head arrangement 46 with a total of four print heads 47-50, which can be pivoted relative to one another in order to enable better adaptation to the surface of a curved component 51.

Figure 23 shows a pixel 52 that can be printed onto a component 53 using the coating method according to the invention by means of a print head. For simplicity, the pixel 52 is shown individually in the drawing. In practice, however, numerous pixels 52 are applied.

The pixel 52 consists of several layers 54-57 arranged one above the other.

The three lower layers 55-57 consist of the primary colors red, green, and blue of the RGB color system. Alternatively, however, the lower layers can also consist of the primary colors of another color system, such as the CMYK color system. The superimposed layers 55-57 then create a specific color tone through subtractive color mixing.

The top layer, on the other hand, consists of a semi-transparent metallic varnish to achieve a metallic effect. Figure 24 shows in a highly simplified form a coating device according to the invention with a multi-axis robot 58, which moves a printing head 59 along predetermined coating agent paths over a component surface 60, wherein the Robot 58 is controlled by a robot controller 61. The robot controller 61 controls the robot 58 in such a way that the print head 59 is guided along predetermined coating agent paths over the component surface 60, wherein the coating agent paths lie next to one another in a meandering manner.

A special feature here is that an optical sensor 62 is additionally attached to the print head 59, which detects the position and course of the previous coating agent web during operation so that the current coating agent web can be precisely aligned with the previous coating agent web.

Figure 25 shows in a highly simplified form a variant of a coating device according to the invention with three separate coating agent feeds 63-65, each of which feeds one component of the coating agent to be applied.

The coating agent feeds 63-65 are connected on the output side to a mixer 66, which mixes the individual components into a coating agent mixture, which is then fed to a print head 67. The mixing of the various components of the coating agent thus takes place before application by the print head 67.

Figure 26 shows, in a simplified form, a print head 68 which applies three different components of a coating agent separately to the component surface, whereby the mixing of the individual components only takes place on the component surface.

Figure 27 shows in schematic form a print head 69 for applying drops of coating agent 70 to a component surface 71.

The print head 69 has a coating agent nozzle 72 from which the individual coating agent drops 70 are ejected pneumatically or in some other way.

In addition, the print head 69 has a sheath flow nozzle 73 which surrounds the coating agent nozzle 72 in a ring shape and emits an annular sheath flow that surrounds the individual coating agent drops 70.

On the one hand, this serves to atomise or delimit the individual coating agent drops 70.

On the other hand, the sheath flow emitted by the sheath flow nozzle 73 directs any overspray towards the component surface 71 and thereby improves the application efficiency.

Figure 28 shows in a highly simplified form a print head 69 according to the invention, which is partially connected to the print head 69 according to Figure 27 so that, to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the individual coating agent drops 70 are ejected pneumatically from the coating agent nozzle 72, wherein the coating agent drops 70 are pneumatically accelerated, whereby the maximum possible painting distance is increased, since the individual coating agent drops 70 have a correspondingly greater genetic energy due to the pneumatic acceleration.

Figure 29 shows in a highly simplified form a print head 74 during the application of two adjacent coating paths, wherein the position of the print head 74 in the current coating path is designated without an apostrophe, whereas the position of the print head 74' in the previous coating path is designated with an apostrophe.

The print head 74 has a plurality of coating agent nozzles 75 which are arranged next to one another transversely to the web direction, wherein the outer coating agent nozzles 75 dispense less coating agent than the inner coating agent nozzles 75. As a result, the print head 74 creates a trapezoidal layer thickness distribution 76 on the component surface. This is advantageous because the trapezoidal layer thickness distribution 76 then overlaps with the likewise trapezoidal layer thickness distribution 76' of the previous coating web, which leads to a constant layer thickness.

Figure 30 shows in simplified form a coating device according to the invention, in which the components 77 to be painted are transported along a linear conveyor path 78 through a painting booth, which is known per se from the prior art and therefore does not need to be described in more detail.

The conveyor path 78 is spanned by a portal 79, with numerous printing heads 80 being attached to the portal, which are directed at the components 77 on the conveyor path 78 and coat them with a coating agent.

Figure 31 shows a variation of Figure 19 , so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is the significantly higher packing density of the individual coating agent nozzles.

Figure 32 shows a variation of Figure 18 , so that in order to avoid repetition, reference is made to the above description, the same reference numerals being used for corresponding details.

Here, too, the special feature is that the packing density of the individual coating agent nozzles is considerably higher.

The invention is not limited to the preferred embodiments described above. Rather, numerous variants and modifications are possible, as defined by the claims.

List of reference symbols:

1

Sponsors

2

paint booth

3

Painting robot

4

Painting robot

5

plenum

6

Ceiling

7

Leaching

8

print head

9

print head

10

Air extraction

11

Filter ceiling

12

Coating agent nozzle

13

Color changer

14.1-14.4

Coating agent nozzles

15.1-15.4

Color changer

16.1-16.6

Coating agent nozzles

17

Color changer

18

color mixer

19.1-19.4

Nozzle rows

20

Coating agent nozzles

21.1-21.4

Nozzle rows

22

Nozzle rows

23.1-23.4

Color changer

24

Color changer

25

color mixer

26

color mixer

27

color mixer

28.1-28.4

Nozzle rows

29

Coating agent nozzles

30

Color changer

31

Coating agent supply line

32

Coating agent supply line

33

Coating agent supply line

34

Nozzle arrangement

35.1-35.7

Nozzle rows

36

Coating agent nozzles

37

Nozzle arrangement

38.1-38.5

Nozzle rows

39

edge

40-42

Coating surfaces

43

print head

44

Coating agent nozzles

45

Coating agent nozzles

46

Printhead arrangement

47-50

Printheads

51

component

52

pixel

53

component

54-57

Layers

58

robot

59

print head

60

Component surface

61

Robot control

62

sensor

63

Coating agent supply

66

mixer

67

print head

68

print head

69

print head

70

Coating agent drops

71

Component surface

72

Coating agent nozzle

73

Sheath flow nozzle

74, 74'

print head

75, 75'

Coating agent nozzles

76, 76'

Layer thickness distribution

77

Components

78

Sponsors

79

portal

80

Printheads

Claims (22)

1. Coating device for coating motor vehicle body parts with a multi-axis robot having a multi-axis robot hand on which an application device applying the coating agent is mounted, wherein the robot (3, 4) has several swivelling robot arms, characterised in that the application device is a print head (8, 9) which discharges the coating agent from a plurality of coating agent nozzles (12; 14.1-14.4; 16.1-16.6; 20; 29; 36; 44; 45), the coating agent nozzles of the print head (8, 9) are jointly connected to a coating agent supply line (31) via which the coating agent to be applied is supplied,

   and the print head (8, 9) exhibits an area coating performance of at least 1 m²/min,

   wherein the coating agent is fluid paint and contains pigments, metallic flakes or other solid paint components,

   wherein the coating agent nozzles (12; 14.1-14.4; 16.1-16.6; 20; 29; 36; 44; 45) of the print head (8, 9) are large enough to apply the paint containing the solid paint components,

   wherein the joint coating agent supply line (31) is supplied by a colour changer,

   wherein the print head (8, 9, 43) is rotatably mounted about an axis of rotation and rotates during coating, and

   wherein the print head (8, 9, 43) has coating agent nozzles of different sizes.
2. Coating device in accordance with claim 2, characterised in that the print head (8, 9) exhibits an area coating performance of at least 2 m²/min, 3 m²/min, 4 m²/min or 5 m²/min.
3. Coating device in accordance with claim 1 or 2 with a painting cabin, characterised in that during operation the air downdraft speed in the painting cabin (2) is less than 0.3 m/s, 0.2 m/s, 0.1 m/s, 70 cm/s or 50 cm/s.
4. Coating device in accordance with any one of the preceding claims,
   characterised in that
   the print head (8, 9) is arranged in a painting cabin (2) in which the components are coated with the coating agent,

   b) no wash-out (7) is arranged under the painting cabin (2), which in conventional painting installations washes overspray out of the cabin air in the painting cabin (2),

   c) the coating device is not protected against explosion,

   d) an air extractor (10) is provided which extracts the cabin air from the painting cabin (2) downwards and/or through side channels, and /or

   e) an air filter (11) is provided which is arranged upstream of the air extractor (10) and filters the overspray from the cabin air, and the air filter (11) is designed as a filter ceiling which is arranged on the base of the painting cabin (2) so that the cabin air is extracted from the painting cabin (2) downwards through the filter ceiling (11).
5. Coating device in accordance with any one of the preceding claims,
   characterised in that
   the print head (8, 9) has several coating agent nozzles (29) which are arranged in several nozzle rows (28.1-28.4), more particularly in matrix form in lines and columns, where each nozzle row contains several coating agent nozzles (29), and/or
   b) the coating agent nozzles (29) of the various nozzle rows (28.1-28.4) are jointly connected to a coating agent supply line (31) via which the coating agent to be applied is supplied.
6. Coating device in accordance with any one of the preceding claims,
   characterised in that

   a) the print head (8, 9) has numerous coating agent nozzles (36) which are arranged in parallel nozzle rows (35.1-35.7),

   b) the coating agent nozzles (36) of the print head (8, 9) are essentially of equal size,

   c) the adjacent nozzle rows (35.1-35.7) are offset with regard to each other in the longitudinal direction, more particularly by half the width of a nozzle, and/or

   d) the nozzle rows (35.1-35.7) are arranged transversely, more particularly perpendicularly to the direction of advance of the nozzle head.
7. Coating device in accordance with any one of the preceding claims,
   characterised in that

   a) the print head (8, 9) has numerous coating agent nozzles which are arranged in parallel nozzle rows (38.1-38.5, 39.1-39.5),

   b) the coating agent nozzles within the individual nozzle rows (38.1-38.5, 39.1-39.5) are each of essentially uniform nozzle size, or

   c) the various nozzle rows (38.1-38.5, 39.1-39.5) have nozzle openings of different sizes.
8. Coating device in accordance with any one of the preceding claims,
   characterised in that
   the smaller coating agent nozzles (45) are arranged closer to the axis of rotation of the print head (8, 9, 43) than the larger coating agent nozzles (44).
9. Coating device in accordance with any one of the preceding claims, characterised in that a plurality of application devices are provided which are designed as print heads.
10. Coating device in accordance with any one of the preceding claims characterised in that to coat curved component surfaces several print heads (47-50) are provided which preferably can swivel with regard to each other.
11. Coating device in accordance with any one of the preceding claims, characterised in that the surface areas of the print head (8, 9) that come into contact with the coating agent are provided at least partly with a wearreducing coating.
12. Coating device in accordance with any one of the preceding claims, characterised by an electrostatic coating agent charger and/or compressed air support to improve the application efficiency of the print head (8, 9).
13. Coating device in accordance with any one of the preceding claims, characterised by a position detection system for detecting the spatial position of the print head (8, 9) and/or the component surface to be coated.
14. Coating device in accordance with any one of the preceding claims, characterised by

    a sensor (62) which is positioned together with the print head (59) by the robot (58) and which detects the course of a guide path on the component to be coated (60), and

    a robot controller (61), which on the input side is connected to the sensor (62) and on the output side to the robot (58), whereby the robot controller (61) positions the print head (59) as a function of the course of the guide path.
15. Coating device in accordance with claim 14, characterised in that

    a) the sensor (62) is an optical sensor, and/or

    b) the guide path is a previously applied coating agent path, or

    c) the guide path contains a coating agent that is only visible when illuminated with UV light or IR light.
16. Coating device in accordance with any one of the preceding claims,
    characterised in that

    a) the print head (69) has a sheath flow nozzle (73),

    b) the sheath flow nozzle (73) emits a sheath flow of air or another gas, and

    c) the sheath flow encompasses the coating agent emitted from the coating agent nozzle.
17. Coating device in accordance with any one of the preceding claims,
    characterised in that

    a) the print head (74) has several coating agent nozzles (75) which are arranged next to each other in relation to the direction of the path,

    b) the outer coating agent nozzles (75) emit less coating agent than the inner coating agent nozzles (75).
18. Coating device in accordance with claim 17, characterised in that the print head (74) applies a coating agent path with a layer thickness distribution (76) transversely to the path direction which is a trapezoidal distribution or a Gaussian normal distribution.
19. Coating method for coating motor vehicle body parts, the coating agent being applied by a print head (8, 9) which is mounted on the multi-axis robot hand of a multi-axis robot (3, 4) and discharges the coating agent from a plurality of coating agent nozzles, wherein the robot (3, 4) has several swivelling robot arms, the coating agent nozzles of the print head (8, 9) being jointly connected to a coating agent supply line (31) via which the coating agent to be applied is supplied,

    and the coating agent being applied by the print head (8, 9) with an area coating performance of at least 1 m²/min,

    wherein the coating agent is fluid paint and contains pigments, metallic flakes or other solid paint components,

    wherein the coating agent nozzles (12; 14.1-14.4; 16.1-16.6; 20; 29; 36; 44; 45) of the print head (8, 9) are large enough to apply the paint containing the solid paint components,

    wherein the joint coating agent supply line (31) is supplied by a colour changer,

    wherein the print head (8, 9, 43) is rotatably mounted about an axis of rotation and rotates during coating, and

    wherein the print head (8, 9, 43) has coating agent nozzles of different sizes.
20. Coating method in accordance with claim 19, characterised in that in the area painting of large surface areas the print head (8, 9) rotates in order to achieve an even coating.
21. Coating method in accordance with claim 19 or 20, characterised by the following stages:

    a) detecting of the spatial position of the print head (8, 9) and/or the component surface to be coated,

    b) control and/or regulation of the spatial position of the print head (8, 9) as a function of the detected position.
22. Coating method in accordance with any one of claims 19 to 21,
    characterised in that the nozzle arrangement is changed towards a coating edge (39) in order to achieve a sharp course of the coating edge (39).

Images