EP1772194A2 - Supply device for a coating agent and appropriate operating method - Google Patents

Abstract

A coating reservoir (6) is used for holding and supplying a coating to a coating meter (1), and located upstream from the coating meter and connected on the output side to the coating meter. The coating meter is used for measuring the amount of coating. An independent claim is also included for an operating method of coating supply device.

Description

The invention relates to a coating agent supply device, in particular for a paint shop, and an associated operating method according to the preamble of the independent claims.

Out WO 2004/037436 A1 is a multi-axis painting robot known, which has a rotary atomizer as an application device and can be used, for example, for painting automotive body panels. The supply of the paint to be applied takes place here by a piston dispenser, which is mounted on an arm of the painting robot and is at a high voltage potential, so that the applied by the rotary atomizer paint is electrically charged, resulting in a good order efficiency over the electrically grounded motor vehicle body parts or the other components to be painted. On the same robotic arm, a color changer is still arranged, which is supplied via numerous color supply lines with paints of different colors, the color changer allows the selection of the desired color and supplies the piston dispenser with the associated paint. In operation, the color changer is at an electrical ground potential, so that the numerous color leads must not be made electrically insulating. However, the connection between the color changer and the piston dispenser takes place through an insulation tube, which provides electrical insulation between the color changer lying at ground potential and that for painting ensures high-voltage potential piston dispenser. The electrical potential separation between the color changer and the piston dispenser is achieved by rinsing and cleaning the insulation tube.

A disadvantage of this known painting robot, on the one hand, the relatively long color change time, which leads in particular to frequent color changes to a slowdown of the painting.

On the other hand, the piston dispenser must be refilled even without a color change when the entire filling volume of the piston dispenser has been applied by the rotary atomizer. However, the refilling of the piston dispenser by the color changer is also relatively time-consuming, which slows down the painting process.

Out DE 699 17 411 T2 A painting robot is also known in which a metering pump and a color changer are arranged together in a robot arm of the painting robot, which is associated with the disadvantages mentioned above.

Furthermore, it is off DE 697 14 886 T2 a painting with a nebulizer and two piston dispensers known, the atomizer can be optionally connected to one of the two piston dispenser, while the other piston dispenser is filled. The selection of the desired piston meter takes place here by a complex turning mechanism.

Out DE 691 09 823 T2 and DE 690 01 744 T2 is an electrostatic paint spraying system with two coating agent known, which are arranged one behind the other in the flow direction and separated by an insulating distance. The separation of the two coating agent tanks by the insulating section makes it possible to place the downstream coating agent tank at high voltage potential during the paint application, while the upstream coating agent tank is at ground potential and therefore can be easily filled with paint.

Further coating devices are known from DE 691 0.9 949 T2 . DE 195 24 853 C2 . DE 201 18 531 U1 . DE 199 61 270 A1 and DE 692 28 249 T2 ,

The invention is therefore based on the object to improve the known painting robot described above accordingly.

This object is achieved by a coating agent supply device and by an associated operating method according to the independent claims.

The invention includes the general technical teaching not to fill the coating agent metering device (eg a piston dispenser) directly from the color changer, but indirectly via a coating agent storage container located therebetween. This offers the possibility that the coating agent storage container is already filled during coating with coating material and not only in the color change times, which contributes to a reduction of the color change times. The transfer from the coating agent storage container into the coating agent metering device can be done due to the short and direct connection with very large volume flow. The continuous filling of the coating agent storage container during painting also offers the advantage that due to the time available for filling relatively small paint volume flows in the supply lines (eg color loop lines and special paint supply) sufficient so that the associated lines can have a smaller cross-section, whereby the installation costs are reduced.

The term used in the context of the invention, a coating agent dosing or dosing preferably denotes a device with which the application device to be supplied coating amount (instantaneous flow) can be changed depending on demand, for example, depending on the respective workpiece area and other parameters during the coating, such as in EP 1 314 483 A2 or DE 691 03 218 T2 is explained. This possibility does not exist in known systems in which only by controlled adjustment of a piston, the filling volume of a container is set, such as at DE 690 01 744 T2 ,

For coating, the coating agent metering device is preferably at a high-voltage potential, while the coating-material storage container is at a near-ground potential (preferably ground potential), the coating-material storage container being connected to the coating agent metering device via an insulating path, around the coating material at high-voltage potential Doser isolate against the grounded coating agent storage tank. However, the electrical potentials of the coating agent metering agent and the coating agent storage container are preferably switchable, so that the coating agent metering device is brought to high voltage potential only for painting, whereas the high voltage for filling the coating agent metering device can be switched off.

The insulating section may in this case consist of an insulation tube in which a scraper (for example a stripping piston or a sealing head) is displaceable in order to remove residues of coating agent from the inner wall of the insulating section. On the one hand, this cleaning of the insulating section prevents the insulation capacity of the insulating section from being impaired by coating agent residues which have remained in the insulating section. On the other hand, contamination of the residual coating agent residues in the insulating section is avoided by cleaning the insulating section, which is particularly important in a color change.

In a variant of the invention, the movement of the scraper in the insulating distance in one direction or in both directions by a piston rod, which can be driven, for example, electrically, pneumatically or hydraulically. The piston rod preferably consists of an electrically insulating material in order to achieve the desired insulation effect. As a material for the piston rod is particularly suitable ceramic, since ceramic has a good electrical insulation capability and also has a high mechanical rigidity, which is important for the dosing accuracy. In addition, ceramic has a high abrasion and wear resistance. By default, the piston rod is made of steel. In this case, the scraper must be moved back with the piston rod for electrical isolation.

In another variant of the invention, the scraper is not fixedly connected to the piston rod, but freely movable in the insulating section. The scraper can only be pushed in the Isolierstrecke of the piston rod. The movement of the scraper in the other direction takes place in contrast, by a one-sided pressurization of the scraper.

Furthermore, there is also the possibility that the scraper in the Isolierstrecke is completely free to move, so that is dispensed with a piston rod to drive the scraper. The movement of the scraper is also done by a one-sided compressed air of the scraper on the desired side. In this variant of the invention, the scraper can therefore be acted upon on both sides with compressed air.

In a further variant of the invention, the scraper is moved in the one direction towards the coating agent metering device by means of compressed air, while the scraper with the remaining coating agent is pushed back by the coating agent metering device.

In another variant, the connection between the coating agent storage container and the coating agent dosing, however, is not permanent by an insulation tube, but by a detachable docking interface. When the coating agent storage container is filled, it is then located at a potential close to the earth, separate from the docking interface, and is then separated from the coating agent supply line for filling the coating agent metering device and connected to the docking interface, with the coating agent storage container then being disposed thereon High voltage potential is like the coating agent dosing. In this variant of the invention, the coating agent storage container can thus be moved between the high-voltage potential of the coating agent metering device and the near-earth potential of the coating agent supply line.

The coating agent storage container may also be connected directly to the coating agent supply line and / or be mounted on the axis 7 of the painting robot. In this case, the atomizer is grounded after painting (in the case of high voltage) and docked at the meantime filled coating agent storage container for filling. After completing the filling process is undocked. Now you can paint (if necessary with HS).

Furthermore, there is the possibility that the connecting line between the coating agent storage container and the coating agent metering device consists of a piggable tube which is emptied by means of a pig after the transfer process (coating agent storage container → coating agent metering device). This is also the potential separation.

The docking interface for the connection of the coating agent metering device with the coating agent storage container can in this case be mounted in the painting robot, for example in a robot arm, so that the docking interface with the painting robot is movable. In addition to the docking interface, a color changer can also be arranged in the painting robot.

However, there is also the alternative possibility that the docking interface is arranged stationary outside the painting robot. In this arrangement, the docking interface, there is the possibility that the docking interface mitfährt with the painting robot by the docking interface is mounted for example on the axis 7 of the painting robot.

In the preferred embodiment of the invention, the coating agent storage container on an adjustable storage volume, wherein the storage volume is adjustable for example by a compressed air-operated piston. In the case of a color change, this offers the possibility that the new coating agent remaining in the coating agent storage container after the filling of the coating agent metering device is pushed back out of the coating agent storage container back into the coating agent supply line, which is also referred to as "reflow". On the one hand, this "reflow" reduces the coating agent consumption, since the new coating agent remaining in the coating agent storage container after the filling of the coating agent metering device can continue to be used. On the other hand, the cleaning of the coating agent storage container is facilitated thereby, so that less detergent is needed.

The coating agent metering device is preferably a piston dispenser, as described, for example, in the document mentioned above WO 2004/037436 A1 is described. The content of this document is therefore the present description with regard to the structure and operation of a piston dispenser. However, the invention is not limited to piston dispensers with regard to the type of coating agent dispenser, but in principle can also be implemented with other types of dispensers.

The coating agent storage container is preferably a cylinder with a storage piston which is displaceably arranged in the cylinder, wherein the drive of the storage piston can be carried out, for example, by an electric motor, hydraulically or pneumatically. The position of Storage piston then determines the storage volume of the coating agent storage container.

In an advantageous variant of the invention, the coating agent metering device and the coating agent storage container are integrated in a common cylinder.

In one embodiment of this variant of the common cylinder is separated by a centrally disposed in the cylinder partition wall into two sub-cylinders, wherein in one sub-cylinder of the metering of the coating agent metering device is displaceable, while in the other sub-cylinder of the storage piston of the coating agent storage container is displaceable. The drive of the metering piston is preferably carried out by a piston rod, while the drive of the accumulator piston is preferably carried out pneumatically.

In contrast, in another embodiment of this variant with a common cylinder for the coating agent metering device and the coating agent storage container, no dividing wall is arranged in the common cylinder. The storage volume of the coating agent storage container is in this case on the back of Dosierkolbens, wherein in this storage volume of the common cylinder of the accumulator piston is slidably disposed, the drive of the accumulator piston is preferably carried out pneumatically. However, the pneumatic pressure to drive the accumulator piston then acts not only on the accumulator piston, but also on the back of Dosierkolbens, so that the drive of the metering piston should be mechanically sufficiently rigid and therefore preferably takes place by a piston rod.

In another variant of the invention, the coating agent storage container by a section of a Ring line formed. Such loops are known per se in paint shops and described for example in Pavel Svejda: "Processes and Application Methods" (Vincentz Verlag), page 106 et seq. With regard to the structural design of loop systems, reference is therefore made to avoid repetition of the above publication, the content of the present description is attributable to the full extent.

The ring line has in this variant of the invention at least two shut-off valves, which are arranged one behind the other in the ring line in the flow direction and can separate a portion of the loop between the two shut-off valves of the rest of the loop in the closed state. The shut-off valves are in this case arranged so that there is a removal point in the ring line between the two shut-off valves, through which the coating agent can be removed from the loop. Such removal points may be formed for example as T-outlets, which can be closed with a ball valve. However, it is alternatively also possible for the removal points to each have an automatically operating docking valve which automatically opens when a sampling line is docked and is otherwise closed.

In one embodiment of this variant, there is a section between the two shut-off valves in the ring line of a so-called "squeeze-out hose" as he out WO 03/086671 A1 and DE 10 2004 016 951 A1 is described, so that the content of these two documents of the present description in terms of constructive design of the "squeeze-out hose" is fully attributable.

The "squeeze-out tube" has a flexible inner tube through which the coating agent flows. Furthermore, the "squeeze-out tube" on a rigid outer shell, which surrounds the flexible inner tube outside, wherein there is a sealed annulus between the outer shell and the inner tube. Furthermore, the "squeeze-out tube" has an inlet which opens into the annular space between the rigid outer shell and the flexible inner tube and over which a pressure medium can be introduced into the annulus to compress the flexible inner tube. Preferably, an outlet is further provided which branches off from the annular space between the rigid outer shell and the flexible inner tube and allows a discharge of the pressure medium from the annulus to adjust the pressure in the annulus and thus the desired compression of the flexible inner tube. By a suitable supply or discharge of the pressure medium in the annulus, the flexible inner tube can be compressed almost arbitrarily to express the located in the inner tube coating agent on the removal point. The "squeeze-out tube" thus forms a coating agent storage container, from which the intermediately stored coating agent can be pressed via the removal point into the coating agent metering device when it is docked to the removal point.

The invention is particularly advantageous for the application of water-based paint, but the invention is not limited to water-based paint with respect to the coating agent to be applied, but in principle also feasible with other types of coating agents.

Furthermore, the invention comprises not only the above-described coating agent supply device according to the invention, but also a complete painting robot with such a coating agent supply device. In this case, the coating agent metering device and the coating agent storage container are preferably arranged in or on one or more robot arms of the painting robot.

Finally, the invention also encompasses a corresponding operating method, as already apparent from the present description of the coating agent supply device according to the invention.

Figur 1

eine vereinfachte Darstellung einer erfindungsgemäßen Beschichtungsmittel-Versorgungseinrichtung für einen Lackierroboter, wobei ein Beschichtungsmittel-Speicherbehälter über eine Isolierstrecke mit einem Beschichtungsmittel-Dosierer verbunden ist,

Figuren 2A, 2B

ein alternatives Ausführungsbeispiel einer erfindungsgemäßen Beschichtungsmittel-Versorgungseinrichtung, bei dem der Beschichtungsmittel-Speicherbehälter zwischen einem Massepotential und einem Hochspannungspotential verfahrbar ist und über eine Andock-Schnittstelle vorübergehend mit dem Beschichtungsmittel-Dosierer verbunden wird,

Figur 3

ein weiteres alternatives Ausführungsbeispiel einer erfindungsgemäßen Beschichtungsmittel-Versorgungseinrichtung, bei der der Beschichtungsmittel-Speicherbehälter zusammen mit dem Beschichtungsmittel-Dosierer in einem gemeinsamen Zylinder integriert ist, wobei sich in dem gemeinsamen Zylinder eine Trennwand befindet,

Figur 4

eine Abwandlung des Ausführungsbeispiels gemäß Figur 3 ohne eine Trennwand in dem gemeinsamen Zylinder,

Figuren 5A-5J

eine Lackieranlage mit einem Farbwechsler, einem Beschichtungsmittel-Speicherbehälter, einer Isolierstrecke, einem Beschichtungsmittel-Dosierer und einem Rotationszerstäuber, wobei verschiedene Phasen während eines Farbwechsels dargestellt sind,

Figur 6

ein Flussdiagramm zur Verdeutlichung der in den Figuren 5A-5J dargestellten verschiedenen Phasen während eines Farbwechsels,

Figur 7

ein Flussdiagramm eines alternativen Betriebsverfahrens mit einer Direktaufladung von Wasserlack, jedoch ohne "Reflow" aus dem Beschichtungsmittel-Speicherbehälter,

Figur 8

ein Flussdiagramm eines alternativen Betriebsverfahrens mit einer Außenaufladung von Wasserlack und mit "Reflow" aus dem Beschichtungsmittel-Speicherbehälter,

Figur 9

ein Flussdiagramm eines alternativen Betriebsverfahrens mit einer Außenaufladung von Wasserlack, jedoch ohne "Reflow" aus dem Beschichtungsmittel-Speicherbehälter,

Figur 10

eine vereinfachte Darstellung eines Lackierroboters mit einem beweglich geführten Beschichtungsmittel-Dosierer und einem ortfest montierten Beschichtungsmittel-Speicherbehälter,

Figur 11

eine vereinfachte Darstellung eines Lackierroboters zur Applikation eines hochohmigen 1-Komponenten-Lösemittellacks mit Direktaufladung,

Figur 12

eine vereinfachte Darstellung eines Lackierroboters zur Applikation eines hochohmigen 2-Komponenten-Lösemittellacks mit Direktaufladung,

Figur 13

eine vereinfachte Darstellung der Isolierstrecke mit einem Abstreifkolben, der durch eine Kolbenstange zwangsgeführt wird,

Figur 14

ein alternatives Ausführungsbeispiel einer I-solierstrecke, bei der der Abstreifkolben nur in eine Richtung von der Kolbenstange geschoben und in die andere Richtung durch Druckluftbeauschlagung bewegt wird,

Figur 15

ein weiteres Ausführungsbeispiel einer Isolierstrecke, bei der der Abstreifkolben in beide Richtungen durch Druckluftbeaufschlagung bewegt wird, sowie

Figuren 16A-B

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Lackieranlage mit einer Ringleitung, wobei ein Abschnitt der Ringleitung einen Beschichtungsmittel-Speicherbehälter bildet.

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 FIGS. Show it:

FIG. 1

a simplified representation of a coating agent supply device according to the invention for a painting robot, wherein a coating agent storage container is connected via an insulating section with a coating agent metering device,

FIGS. 2A, 2B

an alternative embodiment of a coating agent supply device according to the invention, in which the coating agent storage container between a ground potential and a high voltage potential is movable and is connected via a docking interface temporarily with the coating agent dosing,

FIG. 3

a further alternative embodiment of a coating agent supply device according to the invention, in which the coating agent storage container is integrated together with the coating agent metering device in a common cylinder, wherein a partition wall is located in the common cylinder,

FIG. 4

a modification of the embodiment of Figure 3 without a partition in the common cylinder,

Figures 5A-5J

a painting installation with a color changer, a coating agent storage container, an insulating section, a coating agent metering device and a rotary atomizer, wherein different phases are represented during a color change,

FIG. 6

3 is a flow chart illustrating the different phases during a color change shown in FIGS. 5A-5J;

FIG. 7

a flowchart of an alternative method of operation with a direct charging of water paint, but without "reflow" from the coating agent storage container,

FIG. 8

a flowchart of an alternative operating method with an external charging of water-based paint and with "reflow" from the coating agent storage container,

FIG. 9

a flowchart of an alternative operating method with an external charging of water-based, but without "reflow" from the coating agent storage container,

FIG. 10

a simplified representation of a painting robot with a movably guided coating agent dosing and a stationary mounted coating agent storage container,

FIG. 11

a simplified representation of a painting robot for the application of a high-resistance 1-component solvent-based paint with direct charging,

FIG. 12

a simplified representation of a painting robot for the application of a high-resistance 2-component solvent-based paint with direct charging,

FIG. 13

a simplified representation of the insulating section with a stripping piston, which is forcibly guided by a piston rod,

FIG. 14

an alternative embodiment of an I-solierstrecke, in which the stripping piston is pushed in one direction only by the piston rod and moved in the other direction by Druckluftbeauschlagung

FIG. 15

a further embodiment of an insulating section, in which the stripping piston is moved in both directions by compressed air, as well as

Figures 16A-B

a further embodiment of a painting according to the invention with a ring line, wherein a portion of the ring line forms a coating agent storage container.

In the following, the exemplary embodiment of a coating agent supply device according to the invention shown in FIG. 1 will be described, which may be arranged, for example, on a robot arm of a painting robot, as in the already mentioned document WO 2004/037436 A1 is described for a conventional coating agent supply device, so that the contents of this document with respect to the structure and operation of the painting robot and the other components of the present description is fully attributable.

The illustrated coating agent supply device has a coating agent metering device 1, which in this exemplary embodiment is a piston metering device. The coating agent metering device 1 has a cylinder 2 and a metering piston 3 displaceable in the cylinder 2 in the direction of the arrow, the drive of the metering piston 3 being effected mechanically by a push rod 4, which can be driven, for example, by an electric motor, pneumatically or hydraulically. In the cylinder 2 of the coating agent metering device 1 is located at the front of the metering piston 3, a metering volume 5, which is adjustable by a displacement of the metering piston 3 in the cylinder 2. The metering volume 5 with the coating agent contained therein (eg water-based paint) is in operation on a High voltage potential, as symbolized by the high voltage sign shown. The coating agent delivered by the coating agent supply device is therefore also at a high-voltage potential, which contributes to a good application efficiency in the case of an electrostatic coating. The metering volume 5 opposite side of the cylinder 2 and the push rod 4, however, is at a ground potential, as symbolized by the grounding sign also shown. For electrical isolation of the cylinder 2 and the push rod 4 therefore consist of an electrically insulating material. The material of the cylinder 2 and the push rod 4, however, must be sufficiently rigid on the other hand, in order to achieve a sufficient metering accuracy. The materials and structural details required for potential separation are, for example, in the document DE 102 33 633 A1 so that the contents of this document are fully attributable to the structure and operation of the coating agent metering device 1 of the present specification.

Furthermore, the coating agent supply device according to the invention in this embodiment, a coating agent storage container 6, which consists essentially of a cylinder 7 and a displaceable in the cylinder 7 accumulator piston 8, wherein the accumulator piston 8 is pneumatically driven via a compressed air line 9 and thus an adjustable Storage volume 10 in the cylinder 7 includes. The entire coating agent storage container 6 is in this case at a ground potential, as symbolized by the grounding symbol.

The supply of the coating agent storage container 6 is effected by a coating agent supply line 11, which opens into the storage volume 10 and emanates, for example, from a conventional color changer or a loop.

When filling the coating agent storage container 6, it is desirable that a constantly low volume flow is withdrawn from the ring line. This is useful because sampling with a suddenly increasing volumetric flow would result in a pressure drop in the loop, thereby disturbing pressure-sensitive sampling stations (e.g., hand spatter) on the loop. To avoid such pressure drops in the loop, the accumulator piston 8 can be acted upon via the compressed air line 9 with a counter pressure, which is adjusted so that the removal takes place from the loop with the desired volume flow.

It should be noted that the withdrawn volume flow also depends on the viscosity of the removed coating agent. Thus, a low viscosity of the coating agent leads to a relatively large volume flow from the loop. On the other hand, a high viscosity of the coating agent leads to a correspondingly low volume flow during removal. When setting the pneumatic back pressure on the accumulator piston 8, the viscosity of the coating agent is therefore preferably taken into account, so that the filling of the coating agent storage container 6 is always independent of the viscosity of the coating agent with a constant low flow rate. The filling of the coating agent storage container 6 is preferably carried out until the accumulator piston 8 abuts a predetermined stop, whereby the maintenance of a defined filling quantity is ensured.

As an alternative to the backpressure control described above, there is the possibility that the pneumatic backpressure on the accumulator piston 8 is set at the beginning of a removal to a predetermined value and then not regulated. In the subsequent filling of the coating storage container 6, the back pressure is then not regulated, but increases with increasing filling of the coating agent storage container 6 accordingly, so that the back pressure is a measure of the degree of filling of the coating agent storage container 6. During the filling of the coating agent storage container 6, therefore, the back pressure is continuously measured. After reaching a predetermined target value for the back pressure, the filling of the coating agent storage container 6 is then terminated. At a defined initial volume flow at the beginning of the filling of the coating agent storage container 6 is filled in this way with a defined amount of the coating agent.

From the storage volume 10 of the coating agent storage container 6 further branches off an insulation tube 12, which opens into the metering volume 5 of the coating agent metering 1, wherein the insulation tube 12 in the deflated and cleaned state, the coating agent storage container 6 with respect to the coating agent metering device 1 electrically insulated , which in itself from the already mentioned document WO 2004/037436 A1 is known, so that its content in terms of the structure and operation of the insulating tube 12 of the present description is fully attributable.

However, the insulation tube 12 has a larger line cross-section than the coating feed line 11, so that the coating agent metering device 1 as quickly as possible from the Coating agent storage container 6 can be filled, as will be described in detail. By contrast, the smaller line cross section of the coating agent supply line 11 is harmless, since the filling of the coating agent storage container 6 takes place during painting, so that sufficient time is available for the filling of the coating agent storage container 6. On the other hand, the lower cost of the smaller cross-section of the coating agent supply line 11 is advantageous since smaller lines can be used.

To this embodiment and to the following embodiments is further to mention that before and behind the coating agent storage container 6 and the coating agent metering device 1 further components may be arranged, such as controllable valves, which are not shown in the drawing for simplicity.

Figures 2A and 2B show an alternative embodiment of a coating agent supply device according to the invention, which largely corresponds to the embodiment described above and shown in Figure 1, so that reference is made to avoid repetition of the above description of Figure 1.

A special feature of this exemplary embodiment is that the coating agent storage container 6 in this case is not permanently connected to the coating agent metering device 1 via the insulation tube 12. Instead, the coating agent storage container 6 is movable between two positions, which are shown in Figures 2A and 2B.

In the position shown in Figure 2A is the coating agent storage container 6 with the coating agent supply line 11, but separated from the coating agent doser 1 and then is at an electrical ground potential. In this position, the filling of the coating agent storage container 6 takes place via the coating agent supply line 11.

In the position shown in FIG. 2B, by contrast, the coating agent storage container 6 is connected to the coating agent meter 1 via a docking interface 13, but is separated from the coating agent supply line 11 and then has the same high-voltage potential as the coating agent metering device 1 In this position, the coating agent is transferred from the coating agent storage container 6 into the coating agent metering device 1.

For a color change, the coating agent storage container 6 is first filled with the new coating agent via the coating agent supply line 11, wherein the coating agent storage container 6 is separated from the docking interface 13, as shown in FIG. 2A. During this filling of the coating agent storage container 6, the coating agent dispenser 1 can continue to dose the old coating agent, so that no filling of the coating agent storage container 6 interrupting the painting process is required and therefore sufficient time for filling available.

After filling of the coating agent storage container 6, the coating agent storage container 6 is then connected after further intermediate steps with the docking interface 13, which is shown in Figure 2B. After the connection with the docking interface 13 has been established, it is then possible to store in the storage volume 7 included new coating agent in the metering volume 5 of the coating agent metering device 1 are transferred.

FIG. 3 shows a further exemplary embodiment of a coating agent supply device according to the invention, which partly corresponds to the exemplary embodiment described above and shown in FIG. 1, so that in order to avoid repetition, reference is made in part to the above description of FIG.

A special feature of this exemplary embodiment is that the coating agent storage container 6 is integrated in the cylinder 2 of the coating agent metering device 1 on the rear side of the metering piston 3. For this purpose, a partition wall 14 is arranged in the cylinder 2, which separates the cylinder 2 into two sub-cylinders, wherein in the right in the drawing part cylinder of the accumulator piston 8 is compressed air actuated displaceable.

FIG. 4 shows a modification of the exemplary embodiment according to FIG. 3, so that reference is made to the above description of FIG. 3 to avoid repetition.

A special feature of this embodiment is that it dispenses with the partition wall 14 for the separation of the two partial cylinders. The compressed air for driving the accumulator piston 8 thus also acts on the back of the metering piston 3, which requires a mechanically sufficiently rigid drive of the metering piston 3.

FIGS. 5A to 5J show a painting installation with a coating agent supply device according to the invention in various phases of a color change, wherein the color change sequence is shown in the flowchart in Figure 6 and will be described in more detail later.

The painting installation shown in FIGS. 5A to 5J has the coating agent storage container 6 and the coating agent metering device 1, the structure and mode of operation of which has been described above with reference to FIG.

The input side of the coating agent storage container 6 is connected via a valve assembly 15 with a color changer 16, wherein the color changer 16 may be carried out conventionally, as for example in the document DE 103 35 358 A1 is described, so that the content of this document is attributable to the present description in its entirety.

On the output side, the coating agent metering device 1 is connected via a further valve arrangement 17 with a rotary atomizer 18, wherein from the rotary atomizer 18 a return line 19 goes off, can be rinsed on the remaining coating agent.

Another return line 20 is derived from the valve assembly 15, wherein on the return line 20 also remaining coating agent can be removed.

The individual phases illustrated in FIGS. 5A to 5J during a color change will now be described below, wherein the fluid-carrying lines are shown in bold in the drawings.

FIG. 5A initially shows the normal painting operation when the coating agent metering device 1 is still with the old coating agent is filled and dosed to the rotary atomizer 18. The rotary atomizer 18 and the coating agent doser 1 are then at a high voltage potential to enable electrostatic component coating. For electrical insulation of the coating agent metering device 1 relative to the coating agent storage container 6 of the insulation tube is then cleaned and emptied, causing a potential separation. The coating agent storage container 6, however, is initially still empty, with only a relatively low pressure of 2 bar is applied to the accumulator piston 8 via the compressed air line 9. By means of the color changer 16 and the valve arrangement 15, the coating agent storage container 6 is therefore already filled with the new coating agent during the painting process.

After completing the painting with the old paint, the high voltage on the rotary atomizer 18 and the coating agent metering device 1 is then turned off, and the old paint remaining in the coating agent metering device 1 is expressed via the return pipe 19, as shown in Fig. 5B.

After expressing the old paint remaining in the coating agent metering device 1, the coating agent metering device 1 is then rinsed together with the rotary atomizer 18 and the insulation tube 12, as shown in FIG. 5C.

In the next phase according to FIG. 5D, the valve arrangement 15 then opens the connection between the coating agent storage container 6 and the coating agent metering device 1, so that the coating agent metering device 1 and the main line are pressed with the new ink.

Subsequently, in the operating phase shown in FIG. 5E, the coating agent metering device 1 is filled from the coating agent storage container 6 via the insulation tube 12 and the valve arrangement 17 with the new paint.

After filling of the coating agent metering device 1, the ink still contained in the insulation tube 12 is then taken up in the coating agent metering device 1, which is shown in FIG. 5F. This emptying of the insulation tube 12 is important so that the insulation tube 12 can then isolate during the painting operation then lying on high voltage potential coating agent metering 1 electrically relative to the coating agent storage container 6.

After this emptying of the insulation tube 12, the high voltage for the rotary atomizer 18 and the coating agent metering device 1 is then turned on in the phase shown in FIG. 5G, wherein the insulation tube 12 then electrically insulates the coating agent metering device 12 with respect to the coating agent storage container 6.

In the next phase of operation shown in Figure 5H, the main needle of the rotary atomizer 18 is then pressed with the new color and the painting process begins, as shown in Figure 5H.

In the operating phase shown in FIG. 5I, the new color remaining in the coating agent storage container 6 is then forced back into the coating agent supply line 11 via the valve arrangement 15 and the color changer 16, which is also referred to as "reflow".

In the last operating phase of a color change according to FIG. 5J, the coating agent storage container 6 is then rinsed together with the valve arrangement 15 and the color changer 16, in order then to allow a filling with a new color without contamination by paint residues.

FIG. 7 shows an alternative embodiment of an operating method according to the invention, which largely corresponds to the embodiment described above and illustrated in FIG. 6, so that reference is made to the above description to avoid repetition.

A special feature of this embodiment is that the so-called "reflow" according to Figure 5I is omitted. Thus, no coating agent is pressed back into the coating agent supply line 11 from the coating agent storage container 6. This is made possible by the fact that during the filling of the coating agent storage container 6 according to FIG. 5A, exactly the required amount of ink is filled in, which can be checked by a sensor.

This embodiment is particularly suitable for painting with water-based paint and direct charging.

FIG. 8 shows an alternative embodiment of an operating method according to the invention, which largely corresponds to the exemplary embodiment described above and illustrated in FIG. 6, so that reference is made to the above description to avoid repetition.

Here, the painting is done with water paint and external charging and "reflow". The external charging offers over the Direct charging of the coating agent has the advantage that the ventilation of the insulating section 12 (see Figure 5G) can be dispensed with, since the insulation capacity of the insulating section 12 is required only in a direct charging of the coating composition.

FIG. 9 shows an alternative embodiment of an operating method according to the invention, which largely corresponds to the embodiment described above and illustrated in FIG. 6, so that reference is made to the above description to avoid repetition.

Here, a coating of water-based paint with external charging and without "reflow", so that accounts for the operating phases shown in Figures 5G and 5I.

FIG. 10 shows a simplified illustration of a painting robot 21 with a coating agent supply device according to the invention, which largely corresponds to the coating agent supply devices described above, so that reference is made to the above description to avoid repetition.

The coating agent metering device 1 is embodied here as a piston dispenser and integrated into an atomizer 22, which is mounted on a hand axis 23 and is guided by a highly mobile robot arm 24.

By contrast, the coating agent storage container 6 is arranged stationarily outside the painting robot 21 and can be connected to the coating agent metering device 1 via the docking interface 13. For this purpose, the painting robot 21 moves the atomizer 22 so that the docking interface 13 docks on the coating agent storage container 6, after which the coating agent metering device 1 can be filled from the coating agent storage container 6.

Furthermore, the drawing shows an alternative variant in which the dashed line coating agent metering 1 is integrated into the robot arm 24.

The painting robot 21 shown in FIG. 11 partially coincides with the painting robot 21 described above and shown in FIG. 10, so that reference is made to the above description to avoid repetition, the same reference numerals being used for corresponding components.

In this case, the coating agent metering device 1, the coating agent storage container 6 and a color changer 25 are integrated into the robot arm 24, wherein the color changer 25 without an insulating section directly to the front of the coating agent storage container 6 and the coating agent metering device 1 is grown.

The painting robot 21 is used in this embodiment for the application of a high-resistance 1-component solvent-based paint with an electrical direct charging of the paint or for painting without high voltage (pure high-rotation sputtering).

The painting robot 21 shown in FIG. 12 is largely identical to the painting robot 21 described above and shown in FIG. 11, so that reference is made to the above description to avoid repetition, the same reference numerals being used for corresponding components.

A special feature of the painting robot 21 is that 2-component solvent-based paint is applied with direct electrical charging, wherein the one coating component is metered by the coating agent metering device 1, while the other paint component is metered by a piston dispenser 26 via a hose line 27. The additional piston dispenser 26 is in this case arranged stationarily outside the painting robot 21.

FIG. 13 shows a simplified illustration of an insulating section 28 which can be used instead of the insulating tube 12 shown in FIGS. 5A-5J.

The insulating section 28 consists essentially of an electrically non-conductive tube 29 which extends between the two valve assemblies 15 and 17.

In the tube 29, a Abstreifkolben 30 is linearly displaceable, wherein the drive of the Abstreifkolbens 30 is effected by a piston rod 31, at the end of a drive piston 32 is fixed. The drive piston 32 is slidably guided in a pressure cylinder 33, wherein in the pressure cylinder 33 on both sides of the drive piston 32 two compressed-air connections 34, 35 open, via which the drive piston 32 can be unilaterally pressurized with compressed air to the drive piston 32 with the piston rod 31 and the stripping piston 30 to move.

On the one hand, the displacement of the stripping piston 3 serves to scrape coating agent residues on the inner wall of the tube 29 in order to achieve the desired electrical insulation capacity of the insulating section.

On the other hand, the stripping off of the color residues from the inner wall of the tube 29 during a color change prevents contamination by residual color.

The coating agent is thereby transferred in the earthed state via an inlet A and an outlet B, wherein the stripping piston 30 is in its rest position, which is shown in FIG.

After filling of the coating agent metering device 1 from the coating agent storage container 6, the coating agent remaining in the tube 29 is then pushed out of the tube 29 by the advancing stripping piston 30.

If the piston rod 31 is made of an electrically conductive material, the piston rod 31 is then withdrawn from the tube 29 before switching on the electrical voltage for the coating agent charging.

On the other hand, if the piston rod 31 is made of an electrically insulating material, the piston rod 31 remains in the advanced state when the voltage is turned on and is pulled back only after the voltage has been switched off. This is advantageous because the retraction of the stripping piston 30 can lead to streaking on the inner wall of the tube 29, whereby the insulation capacity is impaired.

FIG. 14 shows an alternative exemplary embodiment of an insulating path, which largely corresponds to the exemplary embodiment described above and illustrated in FIG. 13, so that reference is made to the above description to avoid repetition, the same reference numerals being used for corresponding components.

A peculiarity of this embodiment is that the stripping piston 30 is not fixedly connected to the piston rod 31, so that the piston rod 31 can push the stripping piston 30 in one direction only, i. in the drawing to the left.

The movement of the Abstreifkolbens 30 in the other direction (i.e., in the drawing to the right), however, takes place by a one-sided pressurization of the Abstreifkolbens 30 via a further compressed air port 36, which opens into the pipe 29.

FIG. 15 shows an alternative exemplary embodiment of an insulating path, which largely corresponds to the exemplary embodiment described above and illustrated in FIG. 14, so that reference is made to the above description to avoid repetition, the same reference numerals being used for corresponding components.

A special feature of this embodiment is that the stripping piston 30 is pneumatically driven in both directions, for which purpose an additional compressed air port 37 opens into the tube, so that the drive piston 30 can be acted upon on both sides with compressed air. This offers the advantage that it is possible to dispense with the piston rod 31 for driving the stripping piston 30.

Figures 16A and 16B show a further variant of the invention, which can be used in a paint shop with a loop system, as known for example from Pavel Svejda: "Processes and Application Methods" (Vincentz Verlag), page 106 et seq., So that in Following up a detailed description of loop systems can be dispensed with.

In a ring line 38 in this case two controllable shut-off valves 39, 40 are arranged in the flow direction, which in the closed state a portion of the ring line 38 between the two shut-off valves 39, 40 separated from the rest of the ring line 38, wherein the isolated portion of the ring line 38 between the two shut-off valves 39, 40 forms a coating agent storage container in the sense according to the invention, as will be described in detail.

Between the two shut-off valves 39, 40 branches off from the ring line 38, a removal point 41, can be removed from the ring line 38 via the coating means, wherein the removal point 41 has an automatically operating Andockventil 42.

For example, a painting machine 43 can dock on the removal point 41, wherein the painting machine 43 is shown here only schematically and contains a coating agent metering device 44, which is also shown only schematically in order to explain the principle of the invention in this variant.

The docking valve 42 opens automatically when the varnishing machine 43 is docked to the removal point 41, so that the varnishing machine 43 can remove the coating agent from the ring line 38.

After undocking of the painting machine 43 from the removal point 41, the docking valve 42 closes against it independently, to prevent the coating agent from escaping from the loop 38.

Between the two shut-off valves 39, 34, the ring line 38 is formed by a so-called squeeze-out tube 45, wherein the structure and operation of the squeeze-out tube 45, for example, in WO 03/086671 A1 and DE 10 2004 016 951 A1 is described. The squeeze-out tube 45 has a flexible inner tube 46 through which the coating agent flows. The inner tube 46 of the squeeze-out tube 45 is surrounded on the outside by a rigid outer jacket 47, wherein a sealed annular space 48 is located between the outer jacket 47 and the flexible inner tube 46 of the squeeze-out tube 45.

In the annular space 48 opens via a controllable inlet valve 49, an inlet 50, can be introduced via the compressed air or other pressure medium in the annular space 48 between the outer jacket 47 and the flexible inner tube 46.

Furthermore, out of the annular space 48 via a controllable outlet valve 51, an outlet 52, via which the compressed gas can be discharged from the annular space 48 in order to end the compression of the inner tube 46.

The operation of the variant according to FIGS. 16A and 16B will now be described, wherein FIG. 16A shows a state in which the varnishing machine 43 is undocked from the removal point 41, while FIG. 16B shows a state in which the varnishing machine 43 at the removal point 41 is docked and coating agent is transferred via the removal point 41 in the coating agent metering 44 of the coating machine 43.

In the state shown in Figure 16A, the two shut-off valves 39, 40 are opened, so that the coating agent can flow through the loop 38 and the squeeze-out tube 45.

In this state, the inlet valve 49 of the squeeze-out tube 45 is closed while the outlet valve 51 of the squeeze-out tube is opened. In the annular space 48 between the outer jacket 47 and the flexible inner tube 46 then prevails atmospheric pressure, so that the inner tube 46 is not compressed and therefore has a free flow cross-section.

The docking valve 42 of the removal point 41 is also closed in this state, since the coating machine 43 is not docked to the removal point 41.

In a next step, the two shut-off valves 39, 40 of the ring line 38 are then closed so that the squeeze-out tube 45 with the filled inner tube 46 is isolated from the rest of the ring line 38.

Then, the painting machine 43 can dock on the removal point 41, whereupon the docking valve 42 opens automatically.

After docking the painting machine 43 to the removal point 41, the outlet valve 51 of the squeeze-out tube 45 is then closed, while the inlet valve 49 is opened. Thereby compressed air is introduced into the annular space 48 between the outer shell 47 and the inner tube 46, whereby the flexible inner tube 46 is compressed in the radial direction, as shown in Figure 16B. The compression of the inner tube 46 begins in this case Drawing on the right side and propagates in the form of a peristaltic movement in the drawing to the left, so that the coating material contained in the flexible inner tube 46 is pumped via the removal point 41 into the coating agent metering device 44.

In this variant of the invention, therefore, the squeeze-out tube 45 forms the coating agent storage container according to the invention.

The invention is not limited to the preferred embodiments described above. Rather, a variety of variants and modifications is possible, which also make use of the inventive idea and therefore fall within the scope.

LIST OF REFERENCE NUMBERS

1

Coating agents Feeder

2

cylinder

3

dosing

4

pushrod

5

dosing

6

Coating agent storage containers

7

cylinder

8th

accumulator piston

9

Compressed air line

10

storage volume

11

Coating agent supply line

12

spaghetti

13

Docking interface

14

partition wall

15

valve assembly

16

color changers

17

valve assembly

18

rotary atomizers

19

Return line

20

Return line

21

Painting robots

22

atomizer

23

hand axis

24

robot arm

25

color changers

26

Piston

27

hose

28

insulating gap

29

pipe

30

scraping

31

piston rod

32

drive piston

33

pressure cylinder

34

Compressed air connection

35

Compressed air connection

36

Compressed air connection

37

Compressed air connection

38

loop

39

shut-off valve

40

shut-off valve

41

sampling point

42

Andockventil

43

varnishing

44

Coating agents Feeder

45

Squeeze-out hose

46

inner tube

47

outer sheath

48

annulus

49

intake valve

50

inlet

51

outlet valve

52

outlet

A

inlet

B

outlet

Claims (41)

Coating agent supply device, in particular for a paint shop, with a) a coating agent dosing device (1) which doses a coating agent to be applied to an application device,
marked by b) a coating agent storage container (6) for temporarily receiving the coating agent and for supplying the coating agent metering device (1) with the coating agent, wherein the coating agent storage container (6) upstream of the coating agent metering device (1) and arranged on the output side Coating dosing device (1) is connected. Coating material supply device according to claim 1, characterized in that the coating agent storage container (6) via an insulating section (12) with the coating agent metering device (1) is connected. Coating agent supply device according to claim 2, characterized in that the Isolierstrecke (28) has a conduit (12, 29) in which a scraper (30) or a pig is slidable to remove residues of coating agent from the conduit (12, 29) , Coating material supply device according to claim 3, characterized in that the scraper (30) by a piston rod (31) is driven. Coating material supply device according to claim 4, characterized in that the piston rod (31) consists of an electrically insulating material. Coating agent supply device according to one of the preceding claims, characterized in that the coating agent metering device (1) is at least temporarily at a high voltage potential, while the coating agent storage container (6) is at a potential close to the earth. Coating agent supply device according to claim 6, characterized in that the coating agent storage container (6) is movable between the high voltage potential and the near-earth potential. Coating agent supply device according to one of the preceding claims, characterized by a docking interface (13) connected to the coating agent metering device (1) for the separable connection of the coating agent metering device (1) to the coating agent storage container (6). Coating agent supply device according to one of the preceding claims, characterized in that the coating agent storage container (6) has an adjustable storage volume (10). Coating material supply device according to claim 9, characterized in that the storage volume (10) of the coating agent storage container (6) by a piston (8) is adjustable. Coating material supply device according to claim 10, characterized in that the piston (8) of the coating agent storage container (6) is pneumatically operated or hydraulically driven. Coating agent supply device according to one of the preceding claims, characterized in that the coating agent metering device (1) is a piston dispenser, which has a cylinder (2) and a metering piston (3) displaceable in the cylinder (2). Coating agent supply device according to claim 12, characterized in that the coating agent storage container (6) in the cylinder (2) on the back of the metering piston (3), wherein the storage volume (10) by a in the cylinder (2) displaceable Storage piston (8) is adjustable. Coating material supply device according to claim 13, characterized in that the cylinder (2) has a partition wall (14) which separates the coating agent metering device (1) from the coating agent storage container (6). Coating material supply device according to one of the preceding claims, characterized in that the coating agent metering device (1) and / or the coating agent storage container (6) in one or more robot arms (24) of a painting robot (21) or in one of the painting robot ( 21) guided atomizer (22) is arranged. Coating agent supply device according to one of claims 1 to 14, characterized a) that the coating agent storage container (6) is arranged stationary, b) that the coating agent metering device (1) is arranged in or on the painting robot (21) and moves with the painting robot (21), c) that the coating agent metering device (1) via a docking interface (13) separable with the coating agent storage container (6) can be connected. Coating agent supply device according to one of the preceding claims, characterized in that the coating agent storage container (6) has a feed line (11) with a smaller line cross section than the coating agent metering device (1). Coating agent supply device according to one of the preceding claims, characterized in that the coating agent is a water-based paint or a solvent-based paint. Coating material supply device according to one of the preceding claims, characterized in that a) that a color changer (25) is provided for coating with differently colored coating agent, which is connected on the output side to the coating agent storage container (6), b) that the color changer (25) together with the coating agent metering device (1) and the coating agent storage container (6) in the painting robot (21) is arranged. Coating agent supply device according to claim 19, characterized in that the color changer (25) without an intermediate Isolierstrecke with the coating agent storage container (6) and the coating agent metering device (1) is connected. Coating agent supply device according to one of the preceding claims, characterized by a) a ring line (38) for supplying the coating agent to be applied, b) two controllable shut-off valves (39, 40) which are arranged one behind the other in the flow direction in the ring line (38) and in the closed state a between the two shut-off valves (39, 40) located portion of the ring line (38) from the rest of the ring line ( 38), c) a removal point (41) for removing the coating agent from the ring line (38), wherein the removal point (41) between the two shut-off valves (39, 40) branches off from the ring line (38), d) wherein the portion of the ring line (38) between the two shut-off valves (39, 40) forms the coating agent storage container. Coating agent supply device according to claim 21, characterized in that the ring line (38) between the two shut-off valves (39, 40) has the following features: a) a flexible inner tube (46) through which the coating agent flows, b) a substantially rigid outer jacket (47) surrounding the inner tube (46), c) a sealed annular space (48) between the inner tube (46) and the outer jacket (47), and d) an inlet (50) opening into the annular space (48) between the inner tube (46) and the outer jacket (47) for supplying a pressure medium into the annular space (48) for compressing the inner tube (46). Coating material supply device according to claim 22, characterized by an outlet (52) opening out of the annular space (48) between the inner tube (46) and the outer jacket (47). Painting installation with a coating agent supply device according to one of the preceding claims. Operating method for a coating agent supply device comprising the following steps: a) metering of a coating agent by a coating agent metering device (1) to an application device (18),
characterized by the following step: b) supplying the coating agent metering device (1) with the coating agent via a coating agent storage container (6) which is arranged upstream of the coating agent metering device (1) and connected on the output side to the coating agent metering device (1). Operating method according to claim 25,
characterized by the following steps: a) electrical insulation of the coating agent storage container (6) relative to the coating agent metering device (1) through an insulating section (12, 28), b) applying a high-voltage potential to the coating agent metering device (1), c) applying a near-earth potential to the coating agent storage container (6). Operating method according to one of claims 25 to 26, characterized by the following steps during a color change from an old coating agent to a new coating agent: a) filling of the coating agent storage container (6) with the new coating agent from a coating agent supply line (11) during the metering of the old coating agent by the coating agent metering device (1), b) terminating the metering of the old coating agent by the coating agent metering device (1), c) filling the coating agent metering device (1) with the new coating agent from the coating agent storage container (6), d) Start of dosing of the new coating agent by the coating agent dosing (1). Operating method according to claim 27, characterized by the following step: - Emptying of the remaining old coating agent from the coating agent metering device (1) after completing the metering of the old coating agent and before filling the coating agent metering device (1) with the new coating agent. Operating method according to one of claims 27 to 28, characterized by the following step: Rinsing the coating agent metering device (1) with a rinsing agent after emptying the old coating agent from the coating agent dosing device (1) and before filling the coating agent metering device (1) with the new coating agent. Operating method according to one of Claims 27 to 29, characterized by the following steps: a) filling of the coating agent metering device (1) with the new coating agent from the coating agent storage container (6) via an insulating section, b) emptying of the new coating agent from the Isolierstrecke (12) after the filling of the coating agent dosing (1) and before the beginning of the dosage of the new coating agent by the coating agent metering device (1) to the coating agent metering device (1) over the Insulate coating agent storage container (6) electrically. Operating method according to one of claims 27 to 30, characterized by the following step: - Return of the remaining in the coating agent storage container (6) after filling of the coating agent metering device (1) remaining new coating agent in the coating agent supply line (11). Operating method according to one of claims 27 to 31, characterized by the following step: - Rinsing the coating agent storage container (6) with a rinsing liquid after the return of the new coating agent remaining therein in the coating agent supply line (11). Operating method according to one of claims 27 to 32, characterized by the following steps for filling the coating agent metering device (1) with the new coating agent: a) separation of the coating agent storage container (6) from a potential close to the earth after the filling of the coating agent storage container (6) with the new coating agent, b) applying a high-voltage potential to the coating agent storage container (6), c) connection of the coating agent storage container (6) to the coating agent metering device (1) via a docking interface, d) filling the coating agent dosing with the new coating agent via the docking interface from the coating agent storage container (6). Operating method according to one of Claims 25 to 33, characterized by the following steps: a) filling of the coating agent storage container via a coating agent supply line with the coating agent, wherein the coating agent storage container is firmly connected to the coating agent supply line, b) electrical grounding of the application device after an application process, c) docking of the grounded application device with the coating agent metering device on the coating agent storage container by means of an application robot, wherein the application robot guides the application device highly mobile, d) transferring the coating agent from the coating agent storage container into the coating agent metering device when the coating agent metering device is docked to the coating agent storage container, e) undocking of the application device with the coating agent metering device from the coating agent storage container after refilling, f) optionally applying a high-voltage potential to the coating agent metering device and the application device, g) Application of the coating agent. Operating method according to one of claims 25 to 34, characterized in that the filling of the coating agent storage container (6) with a smaller coating agent flow than the metering of the coating agent by the coating agent metering device (1) and / or as the filling of the coating agent metering device (1). Operating method according to one of claims 27 to 37, characterized in that the rinsing of the coating agent storage container (6), the coating agent dosing device (1) and the application device (18) takes place via a single rinsing circuit. Operating method according to one of Claims 27 to 36, characterized by the following steps: a) application of a near-earth potential to the coating agent storage container (6) and the coating agent metering device (1), b) forwarding the coating agent from the coating agent storage container (6) to the coating agent metering device (1) via an emptying line (12, 29). Operating method according to one of claims 25 to 37, characterized in that a portion of a ring line forms the coating agent storage container. Operating method according to one of claims 25 to 38, characterized in that the coating agent storage container (6) from a ring line (38) is filled. Operating method according to one of claims 25 to 38, characterized in that the coating agent storage container (6) has a storage volume (10) which is adjustable by a displaceable piston (8), wherein the piston (8) is pneumatically pressurized with a counter-pressure , which depends on the viscosity of the coating agent. Operating method according to claim 40, characterized in that the back pressure is adjusted so that the volume flow during filling of the coating agent storage container (6) is independent of the viscosity of the coating composition.

Images