EP1634651A1 - Method, coating device and rotational atomizer for coating workpieces in series - Google Patents

Abstract

The method involves electrostatically coating a work piece area with an electrically conductive coating material, which is loaded by external electrodes (6) of a manipulator machine, in a coating zone or coating cabin by a rotating atomizer (1). Another work piece area or work piece is coated in the same coating zone or coating cabin by the same atomizer or another atomizer, without loading of the coating material. An independent claim is also included for a coating device for coating of work pieces of components and attachment parts of vehicle bodies.

Description

The invention relates to a method for automatic serial coating of workpieces such as in particular the components and / or attachments of vehicle bodies with electrically conductive coating material and a coating system for carrying out the method according to the preamble of the independent claims.

Since the beginning of the electrostatic coating of workpieces with water-based paint and other coating material of similar high electrical conductivity, there have been innumerable proposals for solving the problem of necessary electrical isolation between the atomizer, which is to charge the coating material to a potential in the order of up to 100 kV, and the usually grounded material supply system. A relatively old, but still used in practice method is the electrical isolation by creating Isolierstrecken within the material line connection (DE 29 00 660, EP 0292778 and pigging eg according to DE 100 59 041 or EP 1 362 642), the direct charging of the coating material within a nebulizer connected to a remote grounded supply system. An alternative solution which is important in practice is external charging of the coating material sprayed by a rotary atomizer through the atomizer on a concentric ring surrounding in finger-like pins of insulating outer electrodes, which make it possible to keep the coating material into the atomizer at ground potential (US 3 393 662, DE 199 09 369; DÜRR / BEHR Technical Manual, Introduction to the Technology of Passenger Car Painting 04/1999, Chapter 4 Atomizers). A variant This alternative method is to arrange the outer electrodes directly on the atomizer housing (EP 1 362 640).

According to a third method also known from practice, the coating material is not supplied to the atomizer from the remote supply device via a line system, but from cartridges mounted in or on the atomizer or in its vicinity, which are removed again after use (EP 0 274 322). EP 0 796 665, EP 0 967 016). Alternatively, it is also known to replace the entire atomizer including a cartridge contained therein and refill (EP 1 245 296, WO 01/15815).

Another problem with the series coating of workpieces is the requirement for preferably fully automatic coating of all workpiece areas including possibly narrow and / or not easily accessible areas such as in particular of interior areas and possibly including attachments of the workpieces in the same cabin. In the example of the painting of vehicle bodies, which is mainly considered here, both the outer surfaces of the body and, as far as possible, all interior areas including the doors and the engine and luggage compartments as well as bumpers, exterior mirrors, etc., are to be coated in a cabin. An important reason for this is the desire for high flexibility of the coating operations, increase in productivity, lower paint losses and last but not least capital investment.

In particular, for the interior coating of vehicle bodies mainly air atomizers are currently used both manual and automatic application, because they are on the one hand much less bulky than that for the Exterior painting conventional and proven rotary atomizer with external electrodes and on the other hand also avoid the mentioned problem of electrical isolation. However, air atomizers have a poorer application efficiency than rotary atomizers (which is here meant high-speed atomizers with bell speeds of typically more than 20,000 rpm), which is defined as the ratio of the sprayed to the amount of material deposited on the workpiece, and other principal disadvantages such as high pollution through overspray. In addition, with the use of air atomizers, a higher air sink rate in the cabin is necessary than with rotary atomizers, whereby the operating costs are increased.

If both the exterior and the interior painting with acceptable efficiency and without the other disadvantages of air atomizers in a painting zone to be carried out, there is so far only the possibility of using rotary atomizers with direct charging of the coating material in the atomizer, which operated depending on the application with or without high voltage can be. However, the potential separation required for direct charging can only be achieved with considerable investment, maintenance and tax expenditure and also requires highly qualified operating personnel. External charge sprayers, which avoid these problems, in contrast, are in many cases not suitable for interior painting, i.a. also because always a sufficient I-solationsabstand must be maintained between the lying on high voltage outer electrodes and the grounded workpiece.

The invention is based on the object, the coating of workpiece areas, of the rotary atomizer used for coating other workpiece areas with external electrodes are difficult to reach for external charging of the coating material, without potential separation problems, but at the same time to allow better application efficiency than when using air atomizers.

This object is solved by the features of the claims.

The invention is based on the finding that the coating of the externally charged or poorly achievable for other reasons less suitable for the electrostatic coating with external charging workpiece areas or workpieces is also possible with relatively good efficiency, if you rotary atomizer eg both for outdoor areas and for Indoors without the known direct charging of the coating material to the atomizer bell and thus used without potential separation problems. In any case, the efficiency is better than in the case of air atomization, the solution hitherto customary in practice for avoiding the potential separation problem in the inner coating. Thus, the advantages of the electrostatic coating with external charging can be combined with the advantage of unrestricted accessibility of workpiece areas by rotary atomizers without external electrodes in the complete automatic coating of workpieces in a cabin or zone with the same manipulator machine, especially in the combined interior and exterior painting. Although the efficiency of the non-electrostatic coating with high-rotation sputtering is lower than in the case of external charging, the cabin or zone has a significantly higher overall efficiency than when air atomizers are used. The manipulator machine is preferably one of the robots customary for vehicle painting.

The coating according to the invention can therefore take place in two steps, preferably with the same device: Coating with charging of the coating material or without charging of the coating material. Both steps can be carried out alternately, wherein in the second step, the outer electrodes can be switched off or preferably removed.

To increase the overall efficiency, it may be useful to work in the non-electrostatic coating with workpiece-dependent different speeds and / or spray jet settings of the rotary atomizer. This is painted on larger surfaces with a wider spray, so that the greatest possible efficiency results. In the case of smaller areas or detail areas, on the other hand, a spray jet of smaller cross section is set with reinforced shaping air. The speeds may typically be in a range of 20,000 to 60,000 rpm when operating without high voltage. In the case of the electrostatic coating, on the other hand, rotational speeds of 30,000 to 70,000 are generally expedient.

Since no additional painting robots or other manipulator machines are required for the coating and the potential separation effort is eliminated and only the very simple high-voltage technology of external charging is required, can be realized by the invention coating systems with the least possible investment.

When using the same rotary atomizer for both the electrostatically and non-electrostatically coated workpiece areas, the invention also has the advantage that during the non-electrostatic coating, the external charging parts removed from the atomizer can be cleaned. This eliminates the previous principal disadvantage of business interruptions in the regular Periods required cleaning of external charging atomizers. Preferably, in the non-electrostatic coating, only components of the external charging device are deposited, for example only the finger-like insulating pins in which the electrodes are seated, or even the entire external charging device, possibly also together with an outer housing of the atomizer. In the context of the invention, although it is also possible to place the entire rotary atomizer used for the electrostatic coating and replace it with a rotary atomizer without outer electrodes for coating other workpiece areas, but the associated coupling and Abkuppelvorgänge and possibly also the bearing air supply of the drive turbine of the Atomizers require higher time and effort.

The outer electrodes or their holding elements and / or other components of the external charging device of the rotary atomizer can be deposited during the non-electrostatic coating and preferably likewise cleaned during the non-electrostatic coating, for example by an automatically controlled cleaning device provided at the depositing point. For this purpose, the parts to be deposited or cleaned are brought by the manipulator machine to the storage or cleaning points.

It is also possible to carry out the cleaning on at least one separate cleaning point, to which the parts of the outer electrode arrangement to be cleaned and / or the atomizer to be cleaned are brought by the manipulator machine. For example, a common cleaning point for all electrode holding elements (fingers) of an atomizer can be provided, which feeds the manipulator machine the individual fingers one after the other, in the case of a painting robot, for example by cyclically rotating the usually designated as the axis 6 last wrist part. Instead, it is also possible to clean the fingers at the same time, expediently together with the atomizer. Also, the atomizer can be cleaned by itself, so without external electrodes.

If the coating system as usual contains several painting robots or other manipulator machines, it may also be useful if at least two machines together use the same storage and / or cleaning point and start alternately, where then placed the relevant parts of the two atomizers in alternation and / or getting cleaned. In this case, in particular, there is also the possibility that the deposited parts of an external charging device are alternately coupled to the atomizer of one machine and then to the atomizer of the other machine, that is shared by both atomizers.

Fig. 1

einen Rotationszerstäuber mit Außenelektroden;

Fig. 2

den Rotationszerstäuber nach Fig. 1, dessen Außenelektroden abgenommen und durch Verschlussstopfen ersetzt sind;

Fig. 3

eine schematische Darstellung der Ablage der Außenelektroden des Zerstäubers nach Fig. 1 in drei aufeinanderfolgenden Schritten;

Fig. 4

eine schematische Darstellung der Befestigung der Verschlussstopfen anstelle der Außenelektroden des Zerstäubers nach Fig. 1 in drei aufeinanderfolgenden Schritten;

Fig. 5

eine Draufsicht auf eine Ablagevorrichtung für den Zerstäuber nach Fig. 1;

Fig. 6

eine andere Ausführungsform eines Rotationszerstäubers, dessen Außenelektroden mit dem Halterungsring der Elektroden abnehmbar sind;

Fig. 7

den Zerstäuber nach Fig. 6, dessen Außenelektroden mit dem Halterungsring abgenommen und durch eine Abdeckung ersetzt sind;

Fig. 8

eine schematische Darstellung der Ablage der Außenelektroden des Zerstäubers nach Fig. 6 in drei aufeinanderfolgenden Schritten;

Fig. 9

eine schematische Darstellung der Befestigung der Abdeckung anstelle des Halterungsrings des Zerstäubers nach Fig. 6 und 7 in drei aufeinanderfolgenden Schritten; und

Fig. 10

eine Draufsicht auf eine Ablagevorrichtung für den Zerstäuber nach Fig. 6.

On two embodiments shown in the drawing, the invention is explained in detail. Show it:

Fig. 1

a rotary atomizer with external electrodes;

Fig. 2

the rotary atomizer of Figure 1, the outer electrodes are removed and replaced by sealing plugs.

Fig. 3

a schematic representation of the deposition of the outer electrodes of the atomizer of Figure 1 in three successive steps.

Fig. 4

a schematic representation of the attachment of the sealing plug in place of the outer electrodes of the atomizer of Figure 1 in three successive steps ..;

Fig. 5

a plan view of a storage device for the atomizer of Fig. 1;

Fig. 6

another embodiment of a rotary atomizer whose outer electrodes are detachable with the support ring of the electrodes;

Fig. 7

the atomizer of Figure 6, the outer electrodes are removed with the support ring and replaced by a cover.

Fig. 8

a schematic representation of the deposition of the outer electrodes of the atomizer of Figure 6 in three successive steps.

Fig. 9

a schematic representation of the attachment of the cover instead of the support ring of the atomizer of Figure 6 and 7 in three successive steps. and

Fig. 10

a top view of a storage device for the atomizer of FIG. 6th

The rotary atomizer 1 shown in Fig. 1 may be mounted in a conventional manner on the wrist of a painting robot, on the flange part 2 releasably attached to the 4 detectable Zerstäuberflansch is attached. The Zerstäuberflansch 4 is surrounded by a suitably made of insulating plastic retaining ring 5, on whose the bell cup 3 facing end face several, eg six, eight or more finger-like protruding electrode holding elements 6 are also arranged distributed from insulating material with uniform angular intervals about the axis of rotation. The holding elements 6 each contain a needle electrode (not shown) which serves for external charging of the coating material radially sprayed from the bell cup 3. The needle electrodes are electrically connected to a high-voltage connection device 7 located in the retaining ring 5, which in turn is connected via a high-voltage cable 8 to the usual high-voltage generator (not shown). As shown, for example, an axial pin 14 on engage the rear end of the electrode in an axial bore of the axis of rotation coaxially embedded in the support ring 5 metallic connecting ring 15 which is connected via a connecting conductor 16 to a metallic connecting element 17 of the high voltage cable 8. Between the retaining ring 5 and the bell cup 3, a housing part 20 of insulating material extends with the illustrated generally cylindrical and partially conical shape, which is surrounded at a radial distance from the outer electrodes.

According to the invention, the finger-like retaining elements 6 serving as external electrodes of the atomizer 1 can be automatically disconnected from the retaining ring 5 of the atomizer and coupled to the needle electrode and optionally an associated resistance or other electrical coupling element 9. The parting plane 10 can in this case according to the representation radially, ie transverse to the axis of rotation between a rear end face of the support members 6 and the end face facing each of a pin-like projection 11 of the support ring 5 extend through the axial bore 12, the mentioned electrical coupling element 9 up to the high voltage Connecting device 7 of the atomizer extends.

For the automatically or automatically controlled releasable and recoverable mechanical connection between the outer electrodes and the remainder of the atomizer, here between the holding elements 6 and the retaining ring 5 may be provided any (not shown) construction such as an automatically latching coupling device. FIG. 2 shows the rotary atomizer 1 according to FIG. 1 without the external electrodes removed by it, in the place of which sealing plugs 18 are placed on the pin-like projections 11 and are locked in them in the manner shown with their shank ends 19. The latching connection (not shown in FIG. 1) of the electrode holding elements 6 in the projections 11 may be similar.

Instead of the closure plugs 18, other possibilities exist, such as automatically usable and detachable common covers, e.g. in the form of a ring body.

Fig. 3 shows in three steps how the outer electrodes of the atomizer 1 are removed with their holding elements 6 of the atomizer and temporarily inserted into a storage device. The storage device has for this purpose a storage plate 30 with holes 31 which are distributed on a circle corresponding to the positions of the outer electrodes on the atomizer 1. In a first step (FIG. 3 a), the atomizer 1 is brought by the robot into a position in which the axis of rotation with the center of the circle and the electrode holding elements 6 are aligned axially with the axes of the bores 31. In the second step (3 b), the robot then inserts the holding elements 6 still attached to the atomizer 1 into the bores 31, to which end the atomizer 1 from its previous position (3 a) parallel to its axis of rotation in the direction of the arrow 33 to the tray 30 is moved. For the housing part 20, a corresponding recess 36 (FIG. 5) is provided in the storage plate 30. The holding elements 6 can be clamped or locked in a suitable manner automatically or by an automatically controlled device in the holes 31 on the tray 30 in this step (3b). In the third step (3c), the robot lifts the atomizer 1 in the opposite direction to the arrow 33 direction 34 again from the storage device, wherein the outer electrodes automatically from their Loosen retaining ring 5 and remain in the tray 30.

While the outer electrodes of the currently common for the serial coating of workpieces such as car bodies rotary atomizer are inclined with a more or less small angle radially outward, the automatic deposition of the finger-like outer electrodes is facilitated by the fact that they parallel with their longitudinal axes in the atomizer described here the axis of rotation of the atomizer are arranged and thus also parallel to the directions of movement of the atomizer on the storage device.

After the nebulizer 1 has deposited its outer electrodes in the manner described, these are replaced by the sealing plugs 18 (FIG. 2), as shown in FIG. 4. The sealing plugs 18 are provided for this purpose, for example on the tray 30 at storage locations 41 in a similar grouping as the holes 31, but at a different location (or on a different storage device accessible to the robot). In a first step (FIG. 4a), the atomizer 1 is placed on the tray 30 by the robot parallel to its axis of rotation so that its projections 11 engage the shank ends 19 of the plugs 18 in the manner illustrated in FIG. 2 (step 4b). Also at this point, the tray has a recess 46 (Fig. 5) for the housing part 20. Then, the atomizer 1 is lifted again with the attached plugs from the storage device (step 4c).

Fig. 5 shows a plan view of the tray 30 according to FIGS. 3 and 4. At 35, the deposition point for the outer electrodes of the atomizer of FIG. 1 is shown with the holes 31, which are parallel to each other on a axes Circular ring are distributed concentrically surrounding the likewise circular recess 36 of the tray 30. The diameter of the central recess 36 corresponds to the outer diameter of the housing part 20 of the atomizer 1 (FIG. 1), so that the atomizer is placed with its projections 11 on the support plate 30 in the manner shown in FIGS. 3 and 4 (steps 3b and 4b) can be. At 45, however, the storage location with the similarly arranged as the holes 31 storage locations 41 for the sealing plug 18 and a corresponding central recess 46 for the housing part 20 of the atomizer 1 is shown.

While the nebulizer 1 was used before the removal of its external electrodes, for example, for electrostatic painting of the outer surfaces of vehicle bodies, with the same nebulizer after putting the sealing plug 18 in the manner described above, for example, interior areas of the bodies such as engine and / or luggage compartments are painted. Thereafter, in the reverse order, the sealing plugs can be deposited again at the deposition site 45 and instead the outer electrodes or their holder elements 6 can be reconnected to the atomizer at the deposition site 35.

The rotary atomizer 1 'with outer electrodes 6' shown in FIG. 6 has the same external appearance as the rotary atomizer 1 of the first embodiment described above, but differs in that the outer electrodes 6 'on its support ring 5' together with this of the Atomizers are removably attached. The radially extending parting plane 10 'between the atomizer 1' and its automatically removable and re-engageable outer electrode arrangement extends here between a rear end face of the support ring 5 'and a her facing end surface of the atomizer remaining on the housing part 60, with which the support ring 5 'can be axially aligned as shown on the outer circumference of the atomizer, since the support ring of the electrodes in the illustrated embodiments forms part of the outer periphery of the atomizer. Also in this embodiment, the support ring 5 'has a larger outer diameter than that of the outer electrodes 6' enclosed housing part 20th

FIG. 7 shows the atomizer 1 'according to FIG. 6, the outer electrodes 6' of which have been removed with their retaining ring 5 'and replaced by a cover ring 70. The cover ring 70 has expediently the same outer diameter as the retaining ring 5 'and is seated with its axially extending cylindrical inner surface 71 on the Zerstäuberflansch 4' and with a parallel thereto axially outer, also cylindrical inner surface on a retaining ring 73 of the atomizer and is in this position held by an automatic or automatically controlled clamping or locking connection.

The missing in Fig. 7 support ring 5 'of the outer electrodes may have on its rear inside a similar shape as the cover ring 70 and in the same way as this automatically fastened to the atomizer and be detachable from it. In addition, the retaining ring 5 'includes a connector (not shown), for example, in or on a ring conductor electrically interconnecting the metallic electrode elements of the external electrodes in the ring 5'. This socket slides automatically when placing the electrode assembly on the pin 75 of the high voltage cable 8 'and thus establishes the electrical contact between the high voltage generator and the electrodes forth. The Cover 70 has a recess 76 for the connecting pin 75.

FIG. 8 shows how, in three successive steps (8a, 8b and 8c), in a manner similar to the deposition of the outer electrodes of the atomizer 1 according to FIG. 3, the retaining ring 5 'with the outer electrodes 6' attached to it in a deposition plate 30 'is filed. Since after lifting the atomizer 1 '(step 8c) and the retaining ring 5' remains in the tray, this (instead of the bores 31 of the first embodiment) includes a single circular recess 80 having a the outer diameter of the support ring 5 'corresponding diameter, in the electrode arrangement is locked automatically or automatically controlled, so that the robot can lift the atomizer 1 'without the electrodes. Since the outer electrodes 6 'are also arranged in this embodiment with its longitudinal axis parallel to the axis of rotation of the atomizer, their free ends are radially within the cylindrical outer periphery of the support ring 5', so that they do not hinder the insertion of the electrode assembly into the recess 80. Subsequently, the robot brings the atomizer 1 'to another deposition point of the tray 30', where in a recess 80 corresponding recess 90 of the cover ring 70 (Fig. 7) is provided. As shown in Fig. 9 in three successive steps, the released from its electrode assembly atomizer 1 'by the robot on the cover ring 70 is placed (steps 9a and 9b) and then lifted with the attached cover ring again from the tray (step 9c). As in the first embodiment, the movements described in FIGS. 8 and 9 are parallel to the axis of rotation of the atomizer. The storage locations of the storage tray 30 'with the respective recesses 80 and 90 for the cover ring 70 (FIG. 9) or for the outer electrodes 6' and the retaining ring 5 '(FIG. 8) are shown in FIG. Also in this embodiment, the atomizer after the non-electrostatic coating in the reverse order can be freed from its cover and re-provided with the interim stored outer electrode assembly.

The storage plate 30 'may include a plurality of storage locations each having a recess 80 or 90 for the electrode arrangements of two or more atomizers or for the associated covers 70. The same applies to the storage device of the first embodiment.

As indicated at 82 in FIG. 8, the depositing devices can be provided with a device for automatically controlled cleaning of the parts removed from the atomizer, in this case the outer electrodes 6 'fastened to the retaining ring 5'. Other parts of the atomizer, including the housing part 20 and the bell cup can be cleaned in this way. For example, the cleaning device 82 may be formed by a container enclosing the deposited parts of the atomizer, which is attached to the back of the tray 30 'opposite the atomizer side, and in which at least the deposited parts are sprayed or irradiated with a cleaning medium. Such cleaning devices are known per se (EP 0 333 040 and 1 367 302). Solvents and compressed air and in particular dry ice, which is known to consist of CO ₂ in solidified form, can be used as the cleaning medium (DE 101 45 168, DE 102 54 159). Such a cleaning device can also be provided for the storage locations of the storage tray 30 (FIG. 5). If there are multiple filing locations for two or more atomizers, can be provided at each storage a cleaning device.

The described embodiments can be modified in various ways. In particular, the possibility already mentioned at the outset is to deposit not only the outer electrodes themselves and possibly their retaining ring for the non-electrostatic coating, but also other components of the external charging device and / or other parts of the atomizer. As has already been mentioned, the rotary atomizers provided with external electrodes can also be completely deposited after the electrostatic coating and replaced by other complete rotary atomizers without external electrodes for the non-electrostatic coating of other workpiece areas, and vice versa. The automatic replacement of complete atomizers is known per se (EP 1 245 296 and 1 245 348).

Claims (30)

Method for the automatic serial coating of workpieces such as in particular the components and / or attachments of vehicle bodies with electrically conductive coating material in a coating zone or coating booth
using at least one rotary atomizer (1) mounted on a manipulator machine (2) with external electrodes (6) placed on a high voltage potential for external charging of the sprayed coating material,
wherein a workpiece portion of the rotary atomizer (1) is electrostatically coated with the coating material charged by the external electrodes (6),
characterized in that in the same coating zone or coating booth another workpiece area or another workpiece is coated with the or another rotary atomizer (1) without charging the coating material. A method according to claim 1, characterized in that the same manipulator machine (2) is used for coating the different workpiece areas or workpieces. A method according to claim 1, characterized in that during the coating of the other workpiece area or workpiece, a rotary atomizer (1) without external electrodes (6) is used. Method according to one of the preceding claims, characterized in that a rotary atomizer provided with removable external electrodes (6) is used, whose external electrodes (6) are removed during the coating of the other workpiece area or workpiece. Method according to one of the preceding claims, characterized in that at least two different rotary atomizers are used, which are automatically detachable mounted on the manipulator machine and exchanged for the coating of the different workpiece areas or workpieces against each other, one of which serves Rotationszerstäuber for electrostatic coating and the other rotary atomizer works without charging the coating material. Method according to one of the preceding claims, characterized in that the outer electrodes in the rotary atomizer (1) on a concentric to the axis of rotation ring holding elements (6) are arranged in insulating material, which for coating the other workpiece area or workpiece of the rotary atomizer (1) become. A method according to claim 6, characterized in that the outer electrodes are removed with the complete external charging device of the rotary atomizer. Method according to claims 6 or 7, characterized in that the outer electrodes are removed from the latter together with the outer housing of the rotary atomizer before the coating of the other workpiece area or workpiece. Method according to one of the preceding claims, characterized in that in the case of painting of vehicle bodies, at least a part of the outer surfaces of the body electrostatically with Rotationszerstäubung and in the same cabin or painting at least part of the Innenlackierbereiche the body are coated with rotary atomization without charging the coating material. Method according to one of the preceding claims, characterized in that the outer electrodes (6) and / or other components (5 ') of the external charging device of the rotary atomizer (1) deposited during the non-electrostatic coating of the other workpiece area or workpiece and provided by a at the deposition site automatically controlled cleaning device (82) to be cleaned. Method according to one of the preceding claims, characterized in that at least the external electrode holding elements (6) of the external charging device and / or the atomizer are brought by the manipulator machine to a cleaning point where the atomizer and / or the outer electrode holding elements (6) are automatically cleaned. A method according to claim 11, characterized in that the holding elements (6) of the outer electrodes of the atomizer from the manipulator machine successively a cleaning point common to them for cleaning only one holding element (6) are supplied. A method according to claim 11, characterized in that all holding elements (6) of the electrodes of the atomizer are cleaned simultaneously and / or the atomizer is cleaned together with the holding elements (6) of its electrodes or without the holding elements. Method according to one of the preceding claims, characterized in that in the non-electrostatic Coating without charging the coating material different surface areas of the workpieces are coated with depending on different atomizer speeds and / or with different spray jet setting. Method according to one of the preceding claims, characterized in that the atomizer speed in the electrostatic coating with charging of the coating material is higher than in the non-electrostatic coating of at least a portion of the surface areas of the workpiece. Method according to one of the preceding claims, characterized in that the atomizer (1) after the electrostatic coating of the manipulator machine (2) is brought to a first storage location (35), where at least its outer electrodes (6) are automatically removed and stored, and the machine (2) subsequently brings the atomizer (1) to a second deposition site (45), where the previously deposited parts (6) are automatically replaced by covering means (18, 70). A method according to claim 16, characterized in that the atomizer (1) at the depositing points (35,45) is moved parallel to its axis of rotation. Method according to one of the preceding claims, characterized in that at least two manipulator machines each bring to them rotary atomizer alternately to a common storage location where at least the holding elements (6) of the outer electrodes of the two atomizers stored and / or cleaned and for example from each other Manipulator machine can be removed. Coating plant for automatic serial coating of workpieces, in particular of the components and / or attachments of vehicle bodies with electrically conductive coating material
with a coating zone or coating booth containing at least one manipulator machine (2),
and with at least one rotary atomizer (1) which can be mounted on the manipulator machine (2) and has external electrodes (6) which are set to a high-voltage potential for external charging of the sprayed-on coating material,
wherein a workpiece portion of the rotary atomizer (1) is electrostatically coated with the coating material charged by the external electrodes,
characterized in that in the same coating zone or coating booth another workpiece area or another workpiece is coated with the or another rotary atomizer (1) without charging the coating material. Coating installation according to Claim 19, characterized in that a rotary atomizer (1) provided with automatically removable outer electrodes (6) is provided, with which the other workpiece area or the other workpiece is coated after removal of the outer electrodes (6). Coating plant according to claim 19 or 20, characterized in that a rotary atomizer (1) with an external charging device is provided, which serves to secure the outer electrodes to the atomizer (1) holder (5) and an electrical connection means 15,17) for connecting the Contains external electrodes to the high voltage,
wherein the outer electrodes are seated in holding elements (6) made of insulating material,
and that for removing the outer electrodes
the holding elements (6) with the electrodes
or the external charging device including the holding elements, the mounting bracket and / or the electrical connection device
or the external charging device including an outer housing of the rotary atomizer to which the external charging device is attached,
are formed as removable from the atomizer unit. Coating installation according to one of Claims 19 to 21, characterized in that a depositing device (30) is provided for the outer electrodes (6) and optionally for the parts (5 ') of the rotary atomizer (1) remote from the outer electrodes (6). Coating plant according to claim 22, characterized in that the storage device (30) is designed for receiving the removable parts of at least two rotary atomizers. Coating installation according to Claim 22 or 23, characterized in that the depositing device (30) is provided with a device (82) for automatically controllable cleaning of the parts (6, 5 ') remote from at least one rotary atomizer (1) or at least the outer electrodes (6) is. External charging device for a rotary atomizer (1), in particular a coating installation according to one of claims 19 to 24, which contains outer electrodes seated in holding elements (6) of insulating material, characterized in that the external charging device or at least the outer electrodes are formed with their holding elements (6) as automatically from the rotary atomizer (1) uncoupled and can be coupled to him and this automatically to a high voltage generator (8) connectable unit. External charging device according to claim 25, characterized in that the detachable and detachable unit except the outer electrodes (6) for fixing to the atomizer (1) serving support (5) and / or an electrical connection means for connecting the outer electrodes (6) contains the high voltage. External charging device according to claim 25 or 26, characterized in that the detachable and detachable unit includes at least a portion of an outer housing of the rotary atomizer. Rotary atomizer with an external charging device with automatically disconnectable from the atomizer and can be coupled to him outer electrodes (6) according to one of claims 25 to 27. Rotary atomiser according to claim 28, characterized in that the outer electrodes (6) are mounted on the atomizer (1) with longitudinal axes parallel to its axis of rotation. Rotary atomiser according to claim 28 or 29, characterized in that covering means (18, 70) are provided as a replacement for the uncoupled parts (6, 5 ').

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