EP2496364A1

EP2496364A1 - Coating method and coating system having dynamic adaptation of the atomizer rotational speed and the high voltage

Info

Publication number: EP2496364A1
Application number: EP10774142A
Authority: EP
Inventors: Frank Herre
Original assignee: Duerr Systems AG
Current assignee: Duerr Systems AG
Priority date: 2009-11-04
Filing date: 2010-11-02
Publication date: 2012-09-12
Anticipated expiration: 2030-11-02
Also published as: WO2011054496A1; PL2496364T3; DE102009051877A1; CN102596422B; US20120219700A1; JP5752701B2; CN102596422A; US10052644B2; EP2496364B1; JP2013509991A; HUE026377T2; PT2496364E; ES2559234T3

Abstract

The invention relates to a coating method and a coating system for coating the component surface of a component with a coating agent by means of an atomizer (4) in a coating system, in particular for painting a body part of a motor vehicle with paint, comprising the following steps: moving the atomizer (4) over the component surface of the component to be coated, or moving the component in the spray jet, thereby applying the coating agent to the component surface by means of the atomizer (4). The atomizer (4) is operated with at least one electrical and/or kinematic operating variable (U, Q+, Q-), comprising a certain high voltage (U) for the electrostatic charging of the coating agent and/or a certain rotational speed of a rotating spray element of the atomizer (4). According to the invention, the electrical and/or kinematic operating variable (U, Q+, Q-) of the atomizer (4) is dynamically varied during the movement of the atomizer (4).

Description

DESCRIPTION Coating process and coating system with dynamic adjustment of atomizer speed

and the high voltage

The invention relates to a coating method and a corresponding coating system for coating components with a coating agent, in particular for the coating of motor vehicle body components with a paint.

In modern paint shops for painting motor vehicle body components multiaxial painting robots are usually used, which lead as a calibration device a rotary atomizer. The painting robot guides the rotary atomizer along programmed pathways over the component surface, with the webs typically being lined up in a meandering manner. Alternatively, however, there is also the possibility that the component to be coated is moved past the atomizer by means of suitable conveyor technology or by a robot. In contrast to the varnishing machines previously used (for example roofing machines and side machines), such varnishing robots are very flexible in their web guidance. In addition, the number of rotary atomizers can be greatly reduced by the use of painting robots, but this leads to higher demands on the area performance and thus also on the coating speed.

During the movement of the rotary atomizer by the painting robot, the outflow quantity (ie the paint stream) and the guide air flow are changed dynamically in order to obtain an optimum paint sprayer. achieve results. For example, little or no steering air is applied when a large-scale painting is desired, for example, in the coating of large-area components (eg hood, roof surface) of motor vehicle body components. In a detail painting, however, a relatively large Lenkluftstrom is delivered to constrict the spray.

In contrast, in the conventional painting plants, the rotational speed of the rotary atomizer and the high voltage of the electrostatic coating agent charging were kept constant by a control. In the case of the known painting installations, therefore, no dynamic adaptation of rotational speed and high voltage took place during the movement of the atomizer, but only a dynamic adaptation of the fluidic operating variables, such as, for example, paint flow and guide air flow. Although the high voltage of the electrostatic coating agent charging can also be changed in the case of the known painting installations, this was not possible dynamically, but only between successive motor vehicle bodies.

A disadvantage of the conventional painting is therefore the unsatisfactory flexibility and dynamics in painting.

The invention is therefore based on the object to provide a correspondingly improved paint shop.

This object is achieved by an inventive coating method and a corresponding coating system according to the independent claims.

The invention is based on the technical knowledge that it is advantageous in the operation of a paint shop, if During the movement of the atomizer not only the fluidic operating variables (eg paint flow, steering air flow) are changed dynamically, but also electrical and / or kinematic operating variables, such as the rotational speed of the rotary atomizer or the high voltage with which the coating agent to be applied is charged electrostatically ,

As has already been explained above, the dynamic change of the electrical and / or kinematic operating variables such as high voltage and / or rotational speed typically takes place during painting or coating, ie within the coating path predetermined by the program control of the coating system, along which the rotary atomizer usually travels Painting or coating robot is moved over the component surface during application. On this coating path, it is known to specify predetermined path points defined by the program control, for example in the teach method or in another manner, for each of which the required (designated as brush) sets of operating quantities can be adjusted and changed according to the surface geometry of the component to be coated. In particular, according to the invention, the said electrical or kinematic operating variables can thus also be changed at these defined path points. Such changes are also conceivable at other locations related to the defined track points, for example when interpolating between adjacent track points.

So far, for various reasons, it has not been attempted to dynamically change the speed and the high voltage during operation of the paint shop.

On the one hand, the drive of conventional rotary atomizers usually takes place pneumatically by turbines in which However, the possible braking effect is much lower than the possible acceleration effect. It is therefore very difficult control technology, the turbine to control so that the speed of the rotary atomizer follows a certain speed curve. In addition, the rotational speed dynamics of the rotary atomizer are influenced by numerous factors, such as the available air pressure to drive the turbine, the mass of the bell cup, which can vary depending on the material used (aluminum, steel or titanium), the diameter of the bell cup, the actual quantity of lacquer to be applied, the viscosity as well as the solids content and the mass of the cup

Paints. On the other hand, dynamic changes in the electrostatic high voltage during operation of the paint shop have not been taken into consideration, i.a. because such changes in voltage depend on the electrical capacity of the coating charge, which is influenced by a number of factors which may change during operation. For example, the electrical capacity may vary depending on the type of paint and the humidity. In addition, the high-voltage cascades used usually have a greater or lesser hysteresis, which has hitherto also a dynamic change in the high voltage in the operation of

Paint shop has held. Depending on the application structure on the robot (eg 1K / 2K, number of colors, number of rinsing agents, conductivity of the paint, hose cross-section), the electrical capacity of the paint shop changes. Almost every system therefore has different electrical capacities that have to be taken up and taken down by the high-voltage cascade. However, the inertia of the electrical operating variables increases with the electrical capacity of the paint shop. A prediction of the behavior of the plant is therefore difficult and a simulation of the painting results therefore also. In the conventional paint shops, therefore, attempts have been made so far to keep the electrical operating variables constant. For the first time, the invention provides for the rotational speed of the rotary atomizer and / or the high voltage of the electrostatic coating agent charge to be adapted dynamically during operation of a coating installation, ie during the movement of the atomizer along the predetermined coating track. This is to be distinguished from a virtually static change in the speed or the high voltage between successive Lackiervorgängen. The term dynamic change used in the context of the invention is therefore preferably based on the fact that the electrical and / or kinematic operating variable (eg rotational speed, high voltage) is changed within a painting track. In addition, within the scope of the invention it is also possible that further operating variables (eg guide air flow, paint flow, outflow quantity, robot speed) of the atomizer or of the paint shop are changed dynamically, such as, for example, fluid operating variables.

An advantage of the invention is the higher dynamics, which allows a faster painting, which in turn leads to shorter cycle times and thus reduces the unit cost (CPU: Cost per Unit) during painting.

Another advantage of the invention is the improved coating result or a higher paint quality.

In addition, the dynamic adaptation of electrical operating variables (eg high voltage) allows a reduction in the number of high-voltage flashovers, resulting in fewer operational disturbances, which in turn causes the so-called first Run rate improves, ie the error rate at the first run of the paint shop.

Furthermore, the invention advantageously makes it possible to save air and thus to reduce the unit costs (CPU) during painting.

In a preferred embodiment of the invention, the dynamics of changing the electrical and / or kinemati see operating size (eg speed, high voltage) and / or the fluidic operating variable (eg paint flow, Lenkluftstrom) of the atomizer is so large that at a setpoint change the response time smaller as 2s, ls, 500ms, 300ms, 150ms, 100ms, 50ms, 30ms

or even less than 10ms. The set time is the time required for a setpoint change to convert at least 95% of the setpoint change.

The term used in the context of the invention

electrical and / or kinematic operating variable preferably depends on the rotational speed of the rotary atomizer and the high voltage of an electrostatic coating agent charge. In the context of the invention, there is the possibility that only the rotational speed is changed dynamically, while the high voltage is set in a conventional manner. Furthermore, there is a possibility that only the high voltage is changed dynamically while the rotational speed is set in a conventional manner. Preferably, however, both the rotational speed and the high voltage are changed dynamically. It should also be mentioned that the term of an electrical and / or kinematic operating variable used in the context of the invention is not limited to the rotational speed of the rotary atomizer and the high voltage of the electrostatic coating agent charging, but also other re electrical or kinematic operating variables of the atomizer or paint shop includes. For example, within the scope of the invention it is also possible for the electrical current of the electrostatic coating agent charge to be changed dynamically, which is advantageous in particular when the coating agent is charged by means of external charging, ie by means of external electrodes. Furthermore, the term used in the context of the invention of a fluidic operating variable preferably depends on the paint stream and the Lenkluftstrom, wherein in the case of several separate Lenkluftströme they can be dynamically adjusted independently of each other. However, the term of a fluidic operating variable used in the context of the invention is not limited to the steering air flow and the paint flow, but fundamentally also encompasses other fluidic operating variables of the atomizer or the paint shop. The main idea of the invention is that the operating variables are no longer kept constant, as in the prior art, by the additional dynamics in the rotational speed and high-voltage control, but that they are highly dynamic in the brush change (previously outflow quantity and steering clearances) for optimum painting For example, the interior areas, but also the outdoor areas and detail areas can be parameterized.

Preferably, the control by means of painting rules and data fields is so intelligent that it is able to change the correct parameter in an auto- oratory manner in order to adapt optimally to the point to be painted. An acceptable quality, highest efficiency and highest coating speed should be achieved. But you can also imagine that the controller should be ranked priorities. Then you could focus on shortest painting time, highest efficiency, lowest Lackierverbrauch, lowest discharge rate, protection of the robot (undynamic possible driving the robot), lowest risk of high voltage risk, best layer thickness distribution, lowest Lackstörungsrisiko (runners, cooker), control of the degree of wetness of the paint, color etc., lay. In a preferred embodiment of the invention, a state variable of the coating system is continuously determined during the movement of the atomizer, wherein the state variable can reproduce, for example, the geometry of the component surface at the ink impact point. This state variable is then used for the dynamic adaptation of the electrical and / or kinematic operating variable and / or the fluidic operating variable. This means that the change in the electrical and / or kinematic operating variable

and / or the fluidic operating variable as a function of the determined state variable in order to optimize the coating result.

The determination of the state variable can be carried out in the context of the invention, for example by a measurement. However, it is alternatively also possible for the state variable of interest to be available in any case as a control variable in a control device and then only has to be read out.

For example, as already briefly mentioned above, the state variable which is taken into account in the dynamic adaptation of the electrical and / or kinematic operating variable and / or the fluidic operating variable, reproduce the geometry of the component at the ink impact point. Thus, in the case of a coating, a large area, essentially ner component surfaces a widely fanned spray desirable to achieve a large area performance, so that the shaping air is then switched off expediently. In addition, then a relatively large paint stream can be selected to allow a correspondingly large area performance, the large paint stream can then be applied only with a correspondingly high speed of the rotary atomizer. Furthermore, in the coating of large-area, substantially flat component surfaces, the high voltage can be chosen to be relatively large, since the risk of electrical flashover is then relatively low. In the case of a coating of strongly curved component surfaces, on the other hand, a relatively strongly constricted spray jet is desirable, so that a relatively large directing air flow is selected. In addition, the high voltage of the coating agent charging should then be relatively small in order to avoid electrical flashovers.

Furthermore, there is the possibility that the state variable, which is taken into account during the dynamic adaptation of the operating variables, indicates whether an interior painting or an exterior painting takes place. Thus, in a interior painting of an interior of a motor vehicle body component usually a strong constricted spray is desirable, whereas in a exterior painting of exterior surfaces of a motor vehicle body component usually a relatively strong fanned spray is desirable, which leads to correspondingly different demands on the steering air flow. In addition, interior painting and exterior paint also differ in the requirements of the high voltage of the coating agent charging, since, for example, in an interior at best a relatively small high voltage is possible to avoid flashovers. It is also possible within the scope of the invention for the state variable, which is taken into account in the dynamic adaptation of the operating variables, to indicate whether the coating is currently taking place with or without electrostatic charging of the coating agent S '.

Another possibility is that the state variable represents the distance between the color impingement point and an electrical earth point at which the component to be painted is electrically grounded. For example, when painting plastic parts (such as bumpers), geometry and dynamics are also of crucial importance, as they are painted partly on electrically grounded components and partly on electrically insulated components, which are, however, fixed with steel mountings. The electrical current of the electrostatic coating agent charge is then dissipated via the wet paint to a ground point that is in communication with the device. At each different point in the geometry, the isolation or proximity to the earth point must be taken into account, so that dynamic adaptation of the high voltage as a function of the distance to the earth point brings advantages.

Furthermore, it is within the scope of the invention, the possibility that the state variable, which is taken into account in the dynamic adjustment of the operating variables, indicating whether the respective component is a plastic component or a component made of an electrically conductive material, which to the above leads mentioned advantages.

Another possibility is that the state variable, which is taken into account in the dynamic adaptation of the operating variables, indicates whether a detailed painting or surface coating is currently taking place. So insist on one Detail painting on the one hand and, in the case of surface painting, on the other hand, different requirements for paint flow, guide air flow, rotational speed and high voltage of coating agent charging.

Furthermore, the state variable taken into account in the dynamic adaptation of the operating variables can reflect whether cleaning of the atomizer is currently taking place or whether the atomizer is being used to apply paint. On the one hand, cleaning of the atomizer on the one hand and use of the atomizer for the application of paint, on the other hand, impose different requirements on paint flow, shaping air flow, rotational speed and high voltage of the coating agent charging. The above-mentioned examples of the state variable can also be combined with one another within the scope of the invention. For example, the operating variables can be adapted dynamically as a function of a plurality of the state variables mentioned above by way of example. In addition, the invention is not limited to the examples mentioned above with regard to the state variables taken into account for the dynamic adaptation, but in principle can also be implemented with other state variables. In addition, within the scope of the invention, the possibility of an automatic adjustment of the operating variables by software. For example, an operating quantity (e.g., jet width) may be changed, after which the other operating quantities (e.g., draft air, paint flow, paint speed, high voltage, speed) are retraced.

In a first example of such an automatic parameter adjustment, a geometry factor which determines the geometry of the atomizer is continuously determined during the movement of the atomizer Component surface at the color impact point reproduces. Depending on this geometry factor, the spray jet width is then adjusted accordingly, which then in turn leads to a corresponding adaptation of steering air flow, paint flow and / or coating speed (ie movement speed of the atomizer).

In a second example of the automatic parameter adjustment, the high voltage on the painting web is changed in an interior painting due to the particular component shape, which automatically leads to a corresponding adjustment of the paint stream (outflow) and the shaping air.

The adaptation of the parameters or the operating variables taking place in the two examples mentioned above by way of example can be carried out automatically by software or by a control program. However, there is also the possibility that the control program merely makes a proposal for adaptation, which can then be implemented by a programmer (teacher) or a plant operator.

Preferably, the high voltage for the electrostatic coating agent charging is generated by means of a high voltage cascade, wherein a rapid reduction of the high voltage can be made by the high voltage cascade is connected by means of a leakage switch or a ground switch directly or via a bleeder to ground. Cascade type high voltage generators for electrostatic coating equipment are well known in the art and have long been common (US 6,381,109, US 4,266,262, etc.) and essentially comprise a multi-stage high voltage cascade connected downstream of a high voltage transformer whose stages consist of diodes and capacitors. A particularly expedient option extremely fast, practically delaying Withstand-free changes in the high voltage consists in replacing the diodes of conventional cascades with high-voltage-resistant photodiodes which can be controlled by illumination and by whose light control the cascade and, suitably, each individual cascade stage can be switched on and off to change the high voltage or controlled with respect to its current ,

Furthermore, within the scope of the invention, there is the possibility that the rotary atomizer is driven by an electric motor, such as e.g. from WO 2008/037456 is known per se, to allow a large speed dynamics.

Alternatively, however, there is also the possibility that the rotary atomizer is hydraulically driven in order to enable the required rotational speed dynamics.

In this case, an electrical dielectric separation can additionally be provided on the rotary atomizer, in order to allow electrostatic coating agent charging despite the electric or hydraulic drive of a rotary atomizer operating at high voltage potential. Possibilities for this are described in the abovementioned WO document.

Preferably, however, the drive of the rotary atomizer is carried out in a largely conventional manner pneumatically by a turbine. Preferably, the turbine can not only accelerate by means of compressed air, but also actively decelerate by means of compressed air in order to achieve the required speed dynamics. For this purpose, it may be expedient, for example, for the turbine wheel of the drive turbine to accelerate desired positive or negative rotational speed changes via one or more several supply and disconnectable additional supply channels to supply additional drive or braking medium (eg air), as is known in principle from EP 1 245 292 B1. It should also be mentioned that for the first time the invention makes it possible for the electrical and / or kinematic operating variables (eg rotational speed, high voltage) of the atomizer to be changed synchronously with the fluidic operating variables (eg steering air flow, paint flow). This means that these different operating variables react synchronously to the setpoint change during a setpoint change.

It should also be mentioned that the term of movement of the atomizer used in the context of the invention may have different meanings. A meaning of this term provides that the component to be coated stands still while the atomizer is moved over the component surface of the stationary component. On the other hand, another meaning of this term is that the atomizer stands still while the component with the component surface to be coated is moved along the atomizer. On the other hand, a third meaning of this term provides that both the atomizer and the component to be coated are moved during the coating and thereby perform a relative movement.

Finally, it should be mentioned that the invention also encompasses a suitably adapted coating system which is suitable for a dynamic adaptation of the electro / kinematic operating variables (for example rotational speed, high voltage).

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 embodiment of the invention with reference to the figures. Show it: 1A-1C, the method according to the invention for the dynamic adjustment of the operating variables of the atomizer in the form of a flow chart,

FIG. 2 shows a first example of an automatic parameter adaptation in the form of a flow chart,

FIG. 3 shows a second example of an automatic parameter adaptation in the form of a flow chart, as well as FIG

Figure 4 is a greatly simplified representation of a paint shop according to the invention.

FIGS. 1A-1C show the method steps according to the invention of a coating method in the form of a flow chart. In this exemplary embodiment, the coating method is used for painting motor vehicle body parts in a paint shop, wherein the painting is carried out by rotary atomizers, which are each guided by a multi-axis painting robot. It should also be mentioned that the process steps described in more detail below are repeated continuously in the painting operation in order to enable a dynamic adaptation of the operating variables of the rotary atomizer.

In a first step S1, it is first determined whether internal painting of an interior of a motor vehicle body component takes place or an exterior painting of exterior surfaces of the motor vehicle body component. This distinction is important because, in the case of interior painting on the one hand and exterior painting on the other hand, different requirements apply to the operating variables (eg guide air flow, High voltage) of the rotary atomizer. Thus, in a exterior paint usually a wide-spread spray makes sense to paint as large as possible can. In contrast, a relatively strong constricted spray jet is desirable in interior lamination in order to be able to paint in more detail.

In a next step S2, a branch to a step S3 or a step S4 then takes place, depending on the type of coating (interior painting or exterior painting).

In the case of interior painting, a corresponding flag IL = 1 is set in step S3. In the case of exterior painting, on the other hand, the flag IL is cleared in the step S4, IL = 0. The flag IL thus indicates whether interior painting or exterior painting is to be carried out so that the flag IL is then stored for later consideration in the dynamic adjustment of the operating variables (for example guide air flow, paint flow, rotational speed, high voltage) of the rotary atomizer.

Subsequently, it is determined in a step S5 whether a detailed painting or a surface coating should take place. This distinction is also important because different requirements are placed on the spray jet on the one hand and on surface painting on the other hand. Thus, in a detail painting a strongly constricted spray is desirable, whereas in a surface painting a highly fanned spray is sought, which is associated with correspondingly different demands on the steering air flow. In a step S6, a branch to a step S7 or a step S8 then takes place, depending on the type of coating (detailed painting or surface painting). In the case of a detail painting, a corresponding flag DL = 1 is set in step S7.

In the case of surface painting, on the other hand, the flag DL is cleared in step S8. DL = 0. The flag DL thus indicates whether a detail painting or a surface painting is carried out so that the flag DL is stored for later consideration in the dynamic adaptation of the operating variables (for example speed, steering air flow, paint flow, high voltage) of the rotary atomizer.

In a next step S9 it is then determined whether the coating is to take place with an electrostatic coating agent charge or without an electrostatic coating agent charge. This distinction is important because a minimum distance to the grounded body component must be maintained in an electrostatic coating agent coating to avoid electrical flashovers. On the other hand, if no electrostatic coating is applied, there is no risk of electrical flashovers, so there are no limitations in positioning the rotary atomizer.

In a step S10 is then in response to the activation or deactivation of the electrostatic

(ESTA: Electrostatic) coating agent charging branched to a step S10 or a step Sil. In the case of electrostatic coating agent charging, a corresponding flag HS = 1 is set in step S10.

On the other hand, if no electrostatic coating agent charge is provided, the flag HS is cleared in the step S in HS = 0. The flag HS thus indicates whether electrostatic coating agent charging takes place or not in the painting operation, so that the flag HS is stored for later consideration in the dynamic adaptation of the operating variables (for example speed, high voltage, directing air flow, paint flow) of the rotary atomizer.

The flags IL, DL and HS are thus state variables that reflect the current state of the paint shop, whereby these state variables can be adopted, for example, from the system control of the paint shop.

In a step S12, the desired spray jet width SB is then determined, which is also preprogrammed and can therefore usually be easily read from the associated program memory which controls the painting process. The spray jet width SB is the width of a coating path on the component surface, within which the layer thickness amounts to at least 50% of the maximum layer thickness.

In a further step S13, a geometry factor GF is then determined as the state variable, which reproduces the component geometry at the color impingement point. Thus, in the painting of essentially flat component surfaces, other requirements are imposed on the operating variables (eg steering air flow, paint flow, high voltage, rotational speed) of the rotary atomizer than in the coating of strongly curved component surfaces. The geometric factor GF can, for example, in the plant control are derived from the stored CAD model (CAD: Computer Aided Design) of the motor vehicle body component to be painted, so that no measurements are required to determine the geometry factor.

In a next step S14, the distance A between the ink impingement point on the component to be painted on the one hand and the electrical earth point of the component is then determined on the other hand, wherein the component is electrically grounded at the earth point. Thus, in the case of electrostatic coating agent charging, the electric current is conducted away via the wet paint to the earth point, so that the isolation or the proximity to the earth point should be taken into account at each different color impact point in order to achieve an optimum painting result.

In addition, in a further step S15, the drawing speed v of the painting robot is determined, wherein the drawing speed v is the speed at which the painting robot moves the rotary atomizer over the component surface during painting. Thus, with a small pulling speed v, only a relatively small paint stream is required, whereas the paint stream must be correspondingly increased with increasing drawing speed v in order to achieve a constant layer thickness.

In a further step S16 it is then determined whether the component to be painted is a plastic component or a metal component, so that this distinction can also be taken into account in the dynamic adaptation of the operating variables (for example speed, high voltage, paint current, steering air flow).

In a step S17, depending on the type of component to be coated (plastic component or metal component), component) branches to a step S18 or a step S19.

In the case of a metal component, a corresponding flag MA = 1 is set in step S18 to indicate that the component to be painted is a metal structure.

In the case of a plastic component, on the other hand, the flag MA is cleared in step S19. MA = 0.

Subsequently, in a step S20 it is determined whether the rotary atomizer is to be cleaned or whether the rotary atomizer applies paint in the normal painting operation. In a step S21 then, depending on the operating mode (cleaning or application), a branch takes place to a step S22 or to a step S23. In the case of a cleaning operation, a corresponding flag RB = 1 is set in step S22. In the case of a normal application mode, on the other hand, the flag RB is cleared in step S23 RB = 0.

The FIGS. 1A and 1B explained above therefore show the determination of state variables of the paint shop which should be taken into account in the dynamic consideration of the operating variables (eg rotational speed, high voltage, paint flow, steering air flow) of the rotary atomizer in order to achieve an optimum painting result. The figure IC with the steps S24-S28, however, shows how the operating variables (eg speed, high voltage, Lenkluftstrom, paint flow) of the rotary atomizer depending on the previously determined state variables (eg Geometry factor GF, spray jet width SB, etc.) are dynamically adjusted. Thus, in step S24, a definition of the enamel flow QLACK corresponds to a predetermined function f1 as a function of the previously determined state variables IL, DL, HS, A, MA, RB, v, GF and SB. The function fl can be stored here in the form of a characteristic field in the system control.

In step S25, the steering air flow QLENKLUFT is then determined according to a function f2 in dependence on the state variables IL, DL, HS, A, MA, RB, v, GF and SB, wherein the function f2 in the form of a characteristic map in the Plant control can be deposited.

In step S26, the high voltage U for the electrostatic coating agent charging according to a function f3 is then set in a similar manner as a function of the previously determined state variables IL, DL, HS, A, MA, RB, v, GF and SB. The function f3 can also be stored in the form of a characteristic field in the system control.

In step S27, the rotational speed n of the rotary atomizer is then set according to a function f4 as a function of the previously determined state variables IL, DL, HS, A, MA, RB, v, GF and SB.

In step S28, the rotary atomizer is then driven by the electrical or kinematic operating variables U and n and by the fluidic operating variables QLACK and QLENKLUFT.

The method steps described above and illustrated in FIGS. 1A-1C are continuously repeated during the ongoing painting operation during the movement of the rotary atomizer, so that the operating variables U, n, QLACK and QLENKLUFT of the rotary atomizer during the movement of the rotary atomizer are constantly dynamically adjusted in order to achieve an optimal painting result. Figure 2 shows a first example of automatic parameter adaptation by software.

Thus, in a first step S1, a geometry factor GF is determined, which reproduces the component geometry at the color impingement point.

In a next step S2, the spray jet width SB is then set as a function of the geometric factor GF in accordance with a predetermined function f1. Thus, in the case of a strongly curved component geometry, a correspondingly strongly constricted spray jet with a correspondingly small spray jet width SB is desirable. When painting a substantially flat component surface, however, a fanned spray with a correspondingly large spray jet width SB is desirable.

In a next step S3 then the steering air flow

QLENKLUFT depending on the desired spray jet width SB set according to a predetermined function f2, which in addition to the desired spray jet width SB and other state variables can be considered, which is shown here only schematically.

In a further step S4, the paint stream QLACK is then determined as a function of the desired spray jet width SB in accordance with a predetermined function f3. Thus, with a large spray jet width SB, a correspondingly large paint flow QLACK is required to achieve the desired

Layer thickness to achieve. The next step S5 then provides that the drawing speed v of the painting robot is set as a function of the desired spray jet width SB in accordance with a predetermined function f4.

In a step S6, the rotary atomizer is then driven with the operating variables QLACK _/ QLENKLUFT thus determined, and the painting robot is moved over the component surface at the optimized drawing speed v.

In this example, therefore, the geometric factor GF is determined in order to derive therefrom the optimum spray jet width SB. The determination of the spray jet width SB then leads to a corresponding adaptation of the directing air flow QLENKLUFT /

Lackstroms QLACK and the pulling speed v. This automatic parameter adjustment is continuously repeated during the operation of the painting robot during the movement of the rotary atomizer, so that the operating variables are adapted dynamically to the geometry of the component at the ink impact point.

FIG. 3 shows a second example of an automatic parameter adaptation during painting, wherein the method steps S1-S5 illustrated in FIG. 3 are continuously repeated during the ongoing painting operation during the movement of the rotary atomizer in order to allow a dynamic adaptation of the operating variables of the rotary atomizer.

In a first step S1, in turn, a geometry factor GF is determined, which reproduces the component geometry at the color impingement point.

In step S2, the high voltage U for the electrostatic paint charging is then determined as a function of the geometry. factor GF determined according to a predetermined function fl.

In addition, in a step S3, the paint flow QLACK is then determined as a function of the geometry factor GF in accordance with a predetermined function f2.

Furthermore, in step S4, the steering air flow QLENKLUFT is also defined as a function of the geometry factor GF in accordance with a predetermined function f3.

In step S5, the rotary atomizer is then driven with the operating variables U, QLACK and QLENKLUFT so adapted. The steps S1-S5 described above are continuously repeated during the operation of the spray booth during the movement of the rotary atomizer in order to dynamically adapt the operating variables U, QLACK and QLENKLUFT to the component geometry during the movement of the rotary atomizer, in order to achieve an optimum painting result.

FIG. 4 shows, in a greatly simplified form, a painting installation according to the invention with a multi-axis painting robot 1, which as an application device guides an electrostatic rotary atomizer 2, as indicated by the dashed block arrow.

The painting robot is controlled by a robot controller 3, the robot controller 3 specifying the position of the tool center point (TCP) of the painting robot 1 and thereby moving the rotary atomizer 2 to predetermined, programmed painting paths. The rotary atomizer 2, on the other hand, is controlled by a control unit 4, as will be described below.

Thus, the rotary atomizer 2, for example, a steering air valve 5, which is controlled by the control unit 4, so that the control unit 4 adjusts the Lenkluftstrom QLENKLUFT, which is discharged from the rotary atomizer 2 for forming the spray.

In addition, the rotary atomizer on a paint valve 6, which is controlled by the control unit 4, so that the control unit 4 by a suitable control of the paint valve 6 controls the paint flow QLACK, which is discharged from the rotary atomizer 2.

In addition, the rotary atomizer 2 has a pneumatic turbine 7, which drives a bell cup of the rotary atomizer 2. A special feature of the turbine 7 is that the turbine 7 can be pneumatically actively accelerated and braked to allow high speed dynamics. For this purpose, the control unit 4 can set an acceleration air flow Q ₊ and a brake air flow Q_ in order to set the desired rotational speed of the rotary atomizer 2. In addition, reference is made to EP 1 245 292 B1 already mentioned above.

Furthermore, the rotary atomizer 2 has a high-voltage electrode 8 in order to electrostatically charge the applied coating agent, which leads to a high degree of application efficiency. The high-voltage electrode 8 can optionally be embodied as an inner electrode or as an outer electrode and is supplied by a high-voltage cascade 9 with a specific high voltage U, the high-voltage cascade 9 is also controlled by the control unit 4 in order to achieve the desired high voltage U.

In addition, the high-voltage cascade is connected via a leakage resistor 10 and a leakage switch 11 to ground in order to reduce the high voltage U quickly. The diverter switch 11 is also controlled by the control unit 4, so that the high voltage U can be rapidly reduced, if this is desirable in the context of dynamic parameter adjustment. However, the high-voltage cascade can also be controlled in particular with photodiodes provided for this purpose, as has already been explained above.

Furthermore, the paint shop has a system controller 12, which communicates bidirectionally with the robot controller 3 and the control unit and supplies, for example, state variables of the paint shop to the control unit 4, so that the control unit 4 these state variables in the dynamic adaptation of the steering air flow QLENKLUFT the paint stream QLACK, the acceleration Nigungsluft Q ₊ , the brake air Q and the high voltage U can take into account.

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 painting robot

2 rotary atomizers

3 robot control

4 control unit

5 steering air valve

6 paint valve

7 turbine

8 high voltage electrode

9 high voltage cascade

10 bleeder resistor

11 leakage switch

12 system control

Claims

1. Coating method for coating a component surface of a component with a coating agent by means of an atomizer (4) in a coating installation, in particular for painting a motor vehicle body component with a paint,

with the following steps:

a) moving the atomizer (4) over the component surface of the component to be coated, and thereby

b) applying the coating agent to the component surface by means of the atomizer (4),

wherein the atomizer (4) with at least one

electrical and / or at least one kinematic operating variable (U, Q ₊ , Q-) is operated, which comprises a certain high voltage (U) for the electrostatic charging of the coating agent and / or a certain rotational speed of a rotating spray-off body of the atomizer (4),

characterized,

c) that the electrical and / or the kinematic operating variable (U, Q +, Q-) of the atomizer (4) during the movement of the atomizer (4) is dynamically changed.

2. Coating method according to claim 1,

characterized,

a) that the atomizer (4) with fluidic operating variables

(QLACK, QLENKLUFT) is operated, wherein the fluid operating variables represent a coating medium flow and / or a Lenkluftstrom, and b) that the fluid operating variables (QLACK QLENKLUFT) of the atomizer (4) during the movement of the atomizer (4) are dynamically changed.

3. Coating method according to claim 1 or 2, characterized by the following steps:

a) determining at least one state variable (IL, DL, HS,

MA, RB, SB, GF, A, v) of the coating system, and b) dynamically adjusting the electrical and / or kinematic operating variable and / or the fluid operating variables (QLACK, QLENKLUFT) of the atomizer (4) during the movement of the atomizer (4 ) as a function of the determined state variable of the coating installation.

4. Coating method according to claim 3,

characterized,

a) that the state variable (HS) of the paint shop indicates whether the painting is carried out with or without electrostatic charging of the coating agent, and / or b) that the state variable (IL) of the paint shop indicates whether an interior painting or exterior painting of the components takes place,

c) that the state variable (GF) of the paint shop reproduces the geometry of the component at a coating agent impingement point,

d) that the state variable (A) of the paint shop reproduces the distance between the coating agent impingement point and an electrical earth point at which the component is electrically earthed,

e) that the state variable (MA) of the paint shop indicates whether the respective component is a plastic component or a component made of an electrically conductive material, f) that the state variable (DL) of the paint shop indicates whether a detail painting or a surface painting takes place, and / or

g) that the state variable (RB) of the paint shop indicates whether the atomizer (4) is being cleaned or whether the atomizer (4) is applying the coating agent.

5. Coating method according to one of the preceding claims, characterized by the following steps:

a) determining a geometry factor (GF) of the component surface at a color impingement point at which the coating agent impinges on the component surface, wherein the geometry factor (GF) reproduces the shape of the component surface at the color impingement point,

b) adjusting a desired spray jet width (SB) as a function of the geometry factor,

c) adjusting at least one of the following operating variables of the atomizer (4) as a function of the spray jet width (SB) or the geometry factor (GF):

Paint stream (QLACK),

Directing air flow (QLENKLUFT),

Painting speed (v) with which the atomizer (4) is moved over the component surface.

6. Coating method according to one of the preceding claims, characterized by the following steps:

a) determining a geometry factor (GF) of the component surface at a color impingement point at which the coating agent impinges on the component surface, the geometry factor (GF) representing the shape of the component surface at the color impingement point, and b) adjusting the high voltage (U) for the electrostatic charging of the coating agent as a function of the geometry factor (GF), and

c) adjusting a paint flow (Q _LACK ) as a function of the geometry factor and / or the high voltage, and / or d) adapting a _{directing air flow} (Q _LE N _KLUFT ) as a function of the geometry _factor (GF) and / or the high voltage (U) ,

7. Coating method according to one of the preceding claims, characterized in that the electrical and / or the kinematic operating _variable and / or the fluidic operating _variable (Q _LACK , Q _LE N _KLUFT ) of the atomizer (4) at a setpoint change a _{response time} of less than 2s , ls, 500ms, 300ms, 150ms, 100ms, 50ms, 30ms, or even less than 10ms, with at least 95% of the setpoint change being implemented within the setup time.

8. Coating method according to one of the preceding claims, characterized in that

a) that the high voltage (U) is generated for the electrostatic coating agent charging by means of a high voltage cascade (9),

b) that the high voltage by means of a Ableitschalters

(11) and / or a bleeder resistor (10) is highly dynamically reduced.

9. Coating method according to one of the preceding claims, characterized in that the atomizer (4) is driven by an electric motor in order to enable a large rotational speed dynamics.

10. Coating method according to one of claims 1 to 8, characterized in that a) that the atomizer (4) is hydraulically or electrically driven to allow a high speed dynamics, and / or

b) that an electrical potential separation is provided in order to allow electrostatic charging of the coating agent despite the hydraulic or electrical drive.

11. Coating method according to one of claims 1 to 8, characterized in that the atomizer (4) is pneumatically driven by a turbine, wherein the turbine can be accelerated and braked by compressed air.

12. Coating method according to one of the preceding claims, characterized in that the electrical and / or kinematic operating variables of the atomizer (4) are changed synchronously with the fluidic operating variables (QLACK / QLENKLUF) of the atomizer (4).

13. Coating system for coating a component surface of a component with a coating agent by means of an atomizer (4) in a coating system, in particular for painting a motor vehicle body component with a paint, with

a) an atomizer (4) for applying the coating agent to the component surface,

b) a coating robot for moving the atomizer

(4) over the component surface, and

c) a control unit (4, 12), which controls the atomizer (4) with at least one electrical and / or at least one kinematic operating variable (U, Q ₊ , Q-), which has a certain high voltage for the electrostatic charging of the coating agent and / or A be- comprises the rotational speed of a rotating spray body of the atomizer (4),

characterized,

d) that the control unit (4, 12) dynamically changes the electrical and / or the kinematic operating variable (U, Q +, Q.) of the atomizer (4) during the movement of the atomizer (4).

14. Coating plant according to claim 13,

characterized,

a) that the control unit (4, 12) controls the atomizer (4) with fluid operating variables (Q _LACK ^ Q _LE N _KL U _FT ), wherein the fluid operating _variables (Q _LA C _K , Q _LE N _KLUFT ) a coating _{medium flow} and / or reproduce a shaping air stream,

b) that the control unit (4, 12) dynamically changes the fluidic operating variables (Q _LACK , Q _LE N _KL U _FT ) of the atomizer (4) during the movement of the atomizer (4).

15. Coating installation according to one of claims 13 to 15, characterized

a) that the control unit (4, 12) determines at least one state variable (IL, DL, HS, MA, RB, v, A, GF) of the coating installation,

b) that the control unit (4, 12) the electrical and / or the kinematic operating _variable and / or the fluidic operating _variables (Q _LACK , Q _{STEERING AIR} ) of the atomizer (4) during the movement of the atomizer (4) in dependence on the determined state variable (IL, DL, HS, MA, RB, v, A, GF) of the coating system dynamically adapts.

16. Coating plant according to claim 15,

characterized, a) that the state variable (HS) of the paint shop indicates whether the coating is carried out with or without electrostatic charging of the coating agent, and / or b) that the state variable (IL) of the paint shop indicates whether an interior painting or exterior painting of the components takes place .

e) that the state variable (MA) of the paint shop indicates whether the respective component is a

Plastic component or is a component of an electrically conductive material,

f) that the state variable (DL) of the paint shop indicates whether a detail painting or a surface painting takes place, and / or

g) that the state variable (RB) of the paint shop reflects whether a cleaning of the atomizer (4) takes place or whether the atomizer (4) applies the coating agent.

17. Coating installation according to one of claims 13 to 16, characterized

a) that the control unit (4, 12) a geometry factor

(GF) of the component surface at a color impingement point at which the coating agent impinges on the component surface, the geometry factor (GF) representing the shape of the component surface at the color impingement point, b) that the control unit (4, 12) dynamically adjusts a desired spray jet width (SB) as a function of the geometry factor (GF),

c) that the control unit (4, 12) dynamically adapts at least one of the following operating variables of the atomizer (4) as a function of the spray jet width (SB) or the geometry factor (GF):

Paint stream (QLACK),

Directing air flow (QLENKLUFT),

- Varnishing speed (v) with the atomizer

(4) is moved over the component surface.

18. Coating installation according to one of claims 13 to 17, characterized

a) that the control unit (4, 12) a geometry factor

(GF) of the component surface at a color impingement point at which the coating agent impinges on the component surface is determined, wherein the geometry factor (GF) reproduces the shape of the component surface at the color impingement point, and

b) that the control unit (4, 12) dynamically adapts the high voltage (U) for the electrostatic charging of the coating agent as a function of the geometry factor (GF), and

c) that the control unit (4, 12) a paint stream (QLACK) n

Depending on the geometry factor (GF) and / or the high voltage (U) dynamically adapts, and / or

d) that the control unit (4, 12) a shaping air flow

(QLE _N KLUFT) depending on the geometry factor (GF) and / or the high voltage (U) adapts dynamically.

19. Coating plant according to one of claims 13 to 18, characterized in that the electrical and / or the kinematic operating variable and / or the fluidic operating large (QLACK, QLENKLUFT) of the atomizer (4) at a setpoint change have a response time of less than 2s, ls, 500ms, 300ms, 150ms, 100ms 50ms, 30ms or even less than 10ms, within the set time at least 95% of the setpoint change implemented becomes.

20. Coating installation according to one of claims 13 to 19, characterized by

a) a high-voltage cascade (9) for generating the high voltage for the electrostatic charging of the coating agent,

b) a leakage switch (11) and / or a bleeder resistor (10) for dynamic reduction of the high voltage.

21. Coating plant according to one of claims 13 to 20, characterized by a coating agent charging with an electrical capacitance which is smaller than 2nF.

22. Coating installation according to one of claims 13 to 21, characterized by an electric motor for driving the atomizer (4).

23. Coating plant according to one of claims 13 to 21, characterized by

a) a hydraulic drive for the atomizer (4),

and or

b) electrical potential separation, in order to allow electrostatic charging of the coating agent despite the hydraulic drive.

24. Coating plant according to one of claims 13 to 21, characterized by a turbine (7) for the pneumatic operation of the atomizer (4), wherein the turbine (7) can be accelerated and braked by compressed air.