EP3297766B1 - Coating unit and its working process - Google Patents

Description

The invention relates to an operating method for a coating system, in particular for a painting system for painting motor vehicle body components. The invention further comprises a corresponding coating system.

In modern painting systems for painting motor vehicle body components, the motor vehicle body components to be painted are usually conveyed by a conveyor along a painting line through several successive painting booths in which the different layers of paint (e.g. basecoat, clear coat) are applied.

The paint to be applied is usually applied using rotary atomizers, which are guided by multi-axis painting robots in a highly mobile manner. When the paint is applied by the rotary atomizer, a large part of the applied paint is deposited on the vehicle body component to be painted and forms the desired paint layer there. However, part of the applied lacquer initially remains as a coating agent mist (“overspray”) in the interior of the painting booth, this excess coating agent mist being disruptive.

To remove the disruptive coating agent mist from the painting booth, the ceiling of the painting booth is usually designed as a so-called filter ceiling, which generates a downward, laminar flow in the entire cabin interior. This downward air flow in the cabin interior presses the disruptive coating agent mist down through the cabin floor, which is designed as a grating, into a washout, which can be designed as a dry separation or as a wet washout and washes out the coating agent contained in the coating agent mist.

However, the removal of the disruptive coating agent mist, which arises in the interior of the motor vehicle body components to be painted by interior painting of inner surfaces of the motor vehicle body components, is particularly problematic. The downward air flow generated by the filter ceiling is in this case shielded by the roof of the motor vehicle body components and can therefore remain relatively long in the interior of the motor vehicle components to be painted, despite the downward air flow. When the painted motor vehicle body components are subsequently conveyed out of the paint booth, the disruptive coating agent mist can then emerge from the interior of the motor vehicle body components and interfere with the next painting process if the coating agent mist cannot then be removed quickly enough.

This problem exists in particular if the motor vehicle body components are not continuously conveyed along the painting line, but rather in stop-and-go operation, since then relatively high accelerations of the motor vehicle body components occur when they are conveyed out of the painting booth. These relatively high accelerations of the motor vehicle body components when they are conveyed out of the paint booth lead to air vortices, which means that the disruptive coating agent mist can remain in the interior of the paint booth for a relatively long time after exiting from the interior of the motor vehicle body components being conveyed out.

Another disadvantage of filter ceilings results from the fact that the downward air flow has to pass a filter in the filter ceiling, which opposes a flow resistance to the downward air flow and thereby limits the flow velocities. The filter cover therefore only enables relatively low flow velocities of the downward air flow, so that the removal of the disruptive coating agent mist (“overspray”) is unsatisfactory.

Reference is also made to the prior art discussed above regarding painting booths with a filter ceiling for removing the excess coating agent mist (overspray) DE 102 09 489 A1 , DE 10 2008 053 178 A1 and DE 10 2011 122 056 A1 . However, these publications only disclose paint booths in which the excess coating agent mist (overspray) is removed only by the downward air flow which emerges from the filter ceiling or is suctioned off via the filter ceiling. This has the disadvantages described above.

Reference should also be made to the technical background of the invention DE 20 2009 006 290 U1 , EP 1 466 670 A1 , DE 10 2007 048 248 A1 and WO 02/078858 A1 .

Finally revealed GB 2 160 639 A an operating method for a coating system according to the preamble of claim 1 and a corresponding coating system according to the preamble of claim 8. However, the removal of the disruptive coating mist is not yet satisfactory. The object of the invention is therefore to improve the removal of the disruptive coating agent mist (“overspray”) from a coating booth accordingly.

This object is achieved by an operating method according to the invention for a coating system or by a corresponding coating system in accordance with the dependent claims.

The invention is based on the technical-physical knowledge already briefly mentioned above that the disruptive excess coating agent mist (“overspray”) remains in the coating booth, in particular due to two phenomena, and must therefore be removed.

• Die zu lackierenden Kraftfahrzeugkarosseriebauteile werden im Vergleich zu älteren Lackieranlagen schneller aus der Lackierkabine ausgefördert und dabei stärker beschleunigt, was zu stärkeren Verwirbelungen des überschüssigen Beschichtungsmittelnebels ("Overspray") führt.
• Die Luftsinkgeschwindigkeit in der Lackierkabine ist bei modernen Lackieranlagen geringer als bei älteren Lackieranlagen.
• Der Lack wird in modernen Lackieranlagen mit größeren Ausbringmengen und Ausflussraten appliziert, was zwar eine größere Flächenbeschichtungsleistung ermöglicht, aber auch zu mehr Overspray führt.
• Bei modernen Lackieranlagen sind die einzelnen Lackierkabinen kürzer und schmaler als früher, was zwar den Energieverbrauch senkt, aber auch die Overspray-Problematik verschärft.
• Bei modernen Lackieranlagen sind in den einzelnen Lackierkabine mehr Roboter und mehr Zerstäuber angeordnet, was die Overspray-Problematik ebenfalls verschärft

On the one hand, this is favored by the following properties of modern painting systems for painting motor vehicle body components:

• Compared to older painting systems, the motor vehicle body components to be painted are conveyed out of the painting cabin more quickly and accelerated at the same time, which leads to greater swirling of the excess coating agent mist (“overspray”).
• The air sink rate in the painting booth is lower in modern painting systems than in older painting systems.
• The paint is applied in modern painting systems with larger application rates and flow rates, which allows a higher surface coating performance, but also leads to more overspray.
• In modern painting systems, the individual painting booths are shorter and narrower than before, which reduces energy consumption but also exacerbates the overspray problem.
• In modern painting systems, more robots and more atomizers are arranged in the individual painting booth, which also exacerbates the overspray problem

On the other hand, the disruptive coating agent mist (“overspray”) in the coating booth is also favored by interior paintwork, the paint being applied in the interior of a motor vehicle body. When a motor vehicle body is conveyed out of the paint booth, the inertia then pushes the coating agent mist out of the motor vehicle body through the rear window. In addition, the wind generated during the removal of a motor vehicle body also pushes the disruptive coating agent mist out of the motor vehicle body through the rear window.

The two disturbing phenomena described above can lead to the fact that the disturbing coating agent mist can deposit from the last painted motor vehicle body on the next motor vehicle body, which can lead to quality problems.

The invention therefore provides that the disruptive coating agent mist ("overspray") in a coating booth is not only removed by the known downward air flow generated by the conventional filter ceiling. Rather, the invention provides that the disruptive coating agent mist in the coating booth is removed by a separate, downward-directed air flow that is not generated by the filter ceiling.

In a preferred exemplary embodiment of the invention, this separate air flow is spatially limited and does not extend over the entire cabin interior, as a result of which distinguishes this separate airflow from the known airflow generated by the filter ceiling.

This separate air flow is preferably not aligned exactly vertically from top to bottom, but angled in the conveying direction, for example at an angle of 5 ° -60 °, 10 ° -55 ° or 15 ° -45 ° to the vertical. This angling of the downward air flow is advantageous because the interfering coating agent mist is then also partially removed in the direction of the cabin exit, as a result of which the area of the cabin interior near the cabin entrance is cleaned more quickly.

This oblique angling of the air flow in the conveying direction relative to the vertical is also possible in the context of the invention with the downward air flow generated by the filter ceiling. The downward air flow is preferably generated by bypassing the filter cover, so that the maximum achievable flow speed is not limited by the flow resistance of the filter in the filter cover.

According to the invention, the downward air flow is generated by an additional flow device, for example by a movable manipulator.

In the preferred exemplary embodiment of the invention, the separate air flow for removing the coating agent mist is generated by a movable manipulator with a plurality of movement axes, which is arranged movably in the cabin interior. This manipulator is preferably used to remove the disruptive coating agent mist a multi-axis robot with serial or parallel robot kinematics.

In a further preferred exemplary embodiment, the movable manipulator has a single axis of movement.

In a preferred variant of the invention, this manipulator removes the disruptive coating agent mist from the cabin interior by blowing air into the cabin interior, the blown air hitting the disruptive coating agent mist and removing it from the cabin interior or at least accelerating the removal of the coating agent mist.

In another, likewise possible variant of the invention, the manipulator, on the other hand, removes the disruptive coating agent mist from the cabin interior by suctioning off the coating agent mist.

The manipulator for removing the disruptive coating agent mist can be arranged within the coating booth within the scope of the invention.

However, there is alternatively also the possibility that the manipulator can be moved along a conveying rail along the conveying direction in order to remove the coating agent mist. This advantageously offers the possibility that the manipulator for removing the disruptive coating agent mist when a component is being conveyed out of the coating booth is tracked to the removed component in order to remove the coating agent mist emerging from the interior of the component as quickly as possible.

With regard to the assembly of the manipulator for removing the coating agent mist, there are various possibilities within the scope of the invention.

For example, the manipulator can be suspended from a ceiling of the coating booth and then release the air flow downward into the coating booth to remove the disruptive coating agent mist. This hanging mounting of the manipulator on the ceiling of the coating booth is also advantageous because the manipulator itself is less susceptible to contamination because the disruptive coating agent mist hardly occurs or only in a low density near the ceiling.

Alternatively, there is the possibility that the manipulator for removing the coating agent mist is mounted on the side of the coating booth, either standing on the booth floor or hanging on the side walls.

There are also various possibilities with regard to the type of manipulator for removing the coating agent.

In a preferred embodiment of the invention, the manipulator is an articulated arm robot with serial robot kinematics and a plurality of non-parallel pivot axes, such articulated arm robots being well known from the prior art and, in conventional painting systems, for example also as application robots or handling robots (e.g. Hood opener, door opener) can be used.

Alternatively, however, it is also possible that it is at the manipulator of the coating-agent mist removing a so-called SCARA robots: is wherein such SCARA robot from the state of the art (SCARA S elective C ompliance A ssembly R obot A rm) are known and used, for example, in paint shops for painting motor vehicle body components as door openers. A feature of such SCARA robots is that the swivel axes of the different robot members are aligned parallel to one another and typically run vertically.

In theory, there is of course also the possibility within the scope of the invention that the manipulator for removing the interfering coating agent is a robot with parallel kinematics.

In one embodiment of the invention, however, the manipulator for removing the disruptive coating agent is a multi-axis application robot which also guides the application device (for example a rotary atomizer) for applying the coating agent. The application robot therefore has several functions. On the one hand, the application robot guides the application device (e.g. rotary atomizer) over the component surface of the components to be coated in order to apply coating agents (e.g. paint). On the other hand, the application robot also serves to remove the disruptive coating agent mist from the interior of the coating cabin.

For this purpose, for example, the application device can blow out steering air, which is normally used to shape the spray jet and is then used in a targeted manner to disrupt the spray Remove coating agent mist from the coating booth. In normal application operation, the steering air is used to shape the spray jet. In addition, the steering air can also be used to blow away and thereby remove the disruptive coating agent mist, of course no application of coating agent in this mode of operation.

Alternatively, there is the possibility that the application robot has, in addition to the steering air nozzle or nozzles, or instead of this, a separate air nozzle that only serves to remove the disruptive coating agent mist.

Furthermore, there is the possibility within the scope of the invention that the manipulator for removing the coating agent mist is a handling robot, for example a door opener or a hood opener, which is used in a painting system for painting motor vehicle body components in order to close doors or bonnets or trunk lids for subsequent interior painting to open.

Finally, there is of course also the possibility that the manipulator for removing the disruptive coating agent mist is provided exclusively for this purpose and is neither used for applying the coating agent nor for handling the components to be coated, which optimizes the design of the manipulator for the purpose of removing the coating agent mist enables.

It has already been mentioned above that the disruptive coating agent mist can be removed from the cabin interior by blowing air in from the manipulator, for which purpose the manipulator (e.g. application robot, Handling robot or separate robot) can guide an air nozzle. In a preferred exemplary embodiment of the invention, the manipulator has a proximal robot arm and a distal robot arm which can be pivoted relative thereto, wherein the air nozzle can be attached to the proximal robot arm and / or to the distal robot arm in order to remove the coating agent mist. However, the air nozzle for removing the coating agent mist is preferably located on the distal robot arm.

To achieve the best possible cleaning effect when removing the disruptive coating agent mist, numerous air nozzles are preferably provided, which can be arranged in a line in the form of a nozzle bar. This nozzle bar is preferably arranged on the distal robot arm and extends along the longitudinal direction of the distal robot arm. However, there is alternatively also the possibility that the nozzle bar is arranged at the end of the manipulator and is always oriented at right angles to the conveying direction and horizontally.

It has already been mentioned at the beginning that when the coated components are conveyed out of the coating booth, coating agent mist can escape from the interior of the coated component, which can impair the subsequent coating process. This disruptive coating agent mist is then initially located in the area of the coating position within the coating booth, ie in the area in which the component was previously coated. In contrast, there is hardly any annoying coating agent mist in the area of the cabin entrance, so that the next component in this area near the cabin entrance can already be coated if the cabin interior is in the area the final coating position is still contaminated by the disruptive coating agent mist.

In a variant of the invention it is therefore provided that the components to be coated are not immediately conveyed to their final coating position when being conveyed into the coating booth, but first to a pre-position which is upstream of the final coating position in the conveying direction. For example, the motor vehicle body components to be painted can protrude with their front area into the painting booth in the preposition, so that the front area (e.g. bonnet, front fenders) can be painted in this preposition while the disruptive coating agent mist is still removed from the final coating position within the painting booth becomes. The components are then conveyed from the preposition to the final coating position when the coating agent mist in the region of the final coating position has been removed and the component has been coated at the preposition in the front region. Then, in the final coating position, the remaining surface areas (e.g. trunk lid, roof, doors, rear fenders) are also coated outside the front area.

It has already been mentioned above that when a component is conveyed out of the coating booth, coating agent mist can escape from the component or can be whirled up by the conveyed-out component, which makes it difficult to remove the coating agent mist from the cabin interior. The removal of the coating agent mist provided within the scope of the invention is therefore preferably spatially concentrated on a cleaning area, the cleaning area does not encompass the entire cabin interior, but is limited to the area of the transported component, where the disruptive coating agent mist emerges from the component and disruptive air vortices are generated. For example, the cleaning area can also be limited to that area of the cabin interior that is slightly behind the component with respect to the conveying direction, since the disruptive coating agent mist emerges from the component when a component is being conveyed outwards, so that this coating agent mist must also be removed there. There is the possibility here that the cleaning area is moved in synchronism with the removed component when the component is being conveyed out, in order to optimize the removal of the emerging coating agent mist. The coating system according to the invention therefore preferably has a control device which synchronizes the movements of the conveyor device and the cleaning area with one another. The control device therefore preferably also controls the movement of the manipulator, which removes the disruptive coating agent mist.

The invention is particularly advantageous if the components to be coated are conveyed through the coating booth in stop-and-go operation, since the components are then accelerated or decelerated when being conveyed in or out of the coating booth, resulting in air turbulence which results in removal of the coating agent mist due to the downward air flow from a conventional filter ceiling. In cooperation with a correspondingly fast conveyor technology, the invention enables a delivery time of less than 13 seconds, 11 seconds or less than 9 seconds, the delivery time in Stop-and-go operation is the time period from one component to a next component.

In addition, it is advantageous if the components to be coated are first accelerated with a relatively low acceleration when they are conveyed out of the coating booth, for which purpose the deceleration during braking is greater for compensation. The relatively low acceleration when conveying out is advantageous because fewer disturbing air vortices are generated which keep the disturbing coating agent mist longer in the cabin interior. In addition, the relatively slow acceleration when conveying out of the coating booth is also advantageous because the coating agent mist located in the interior of the respective component then does not, or at least not completely, exit from the component.

It should also be mentioned that the invention not only claims protection for an operating method according to the invention for a coating system. Rather, the invention also claims protection for a correspondingly designed coating system, the details of the operating method and the coating system being apparent from the above description.

It should also be mentioned that the invention with regard to the component to be coated is not restricted to motor vehicle body components. Rather, the components to be coated can be any components, such as rotor blades of wind turbines or parts (e.g. rotor blade half-shells) thereof or aircraft lines (e.g. wings, tail parts, fuselage parts, etc.).

In addition, with regard to the coating agent applied, the invention is not restricted to lacquers (eg basecoat, clear lacquer) or certain types of lacquer (eg wet lacquer, powder lacquer). Rather, the coating agent can be any coating agent which, when applied, produces a disruptive coating agent overspray.

It has already been mentioned above that the disruptive coating agent mist (“overspray”) is removed from the cabin interior of the coating cabin by a downward air flow. This downward air flow is generated by a blow nozzle arrangement which emits the air flow down through at least one blow nozzle in order to blow down the disruptive coating agent mist downwards. This blowing nozzle arrangement is preferably arranged above the conveying device and also above the components to be coated, for example on a cabin ceiling or on a portal that spans the conveying path. The blowing nozzle arrangement preferably extends transversely to the conveying direction through the coating booth and is movable in the conveying direction. This means that the blow nozzle arrangement can be moved back and forth in the conveying direction. The movable blowing nozzle arrangement can be driven, for example, by a cable drive.

In a variant of the invention, this blowing nozzle arrangement can be pivoted about an axis of rotation transversely to the conveying direction. Here, the blowing nozzles are preferably spaced apart from the axis of rotation, so that the blowing nozzles perform an arcuate movement in a vertical plane parallel to the conveying direction when the blowing nozzle arrangement is pivoted. Here, the blow nozzle arrangement preferably ensures that the blowing nozzles are held in a constant angular orientation relative to the vertical during a pivoting movement. The blowing nozzles therefore preferably remain oriented vertically downwards, so that the air flow is emitted vertically downwards. For example, the blow nozzle arrangement can have a pivotable frame which can be pivoted about the above-mentioned axis of rotation. The axis of rotation preferably runs through a frame edge, while the blowing nozzles are attached to the opposite frame edge.

Alternatively, however, there is also the possibility that the blow nozzle arrangement has a linear travel axis that runs parallel to the conveying direction, so that the blow nozzles can be moved along the conveying direction. Here too, a cable drive can be provided to drive the blow nozzle arrangement.

The blowing nozzles can therefore either perform a swiveling movement or a linear movement. However, it is also possible within the scope of the invention for the blowing nozzles to perform a combined movement which consists of a swiveling movement and an overlaid linear movement.

Furthermore, the invention preferably also provides a control unit which controls the downward air flow, in particular the flow speed, the volume flow (e.g. volume flow) and / or the flow direction can be controlled.

For example, the control unit can switch off or at least weaken the air flow during a painting process. The control unit can then switch on or intensify the air flow during the painting breaks.

A distinction can also be made here between the downward air flow from the filter ceiling (plenum) and the downward air flow, which is additionally generated. The downward air flow from the filter ceiling can then also remain switched on during a painting process, whereas the additional air flow is then switched off or at least weakened. During the painting breaks, both the downward air flow from the filter ceiling and the additional air flow can then be switched on unabated.

In addition, care should preferably be taken to ensure that the downward-directed air flow does not produce any undesirable air flows in the paint booth and that too much air is not introduced into the paint booth. It must be taken into account here that the downward air flow is usually generated during a painting break, the purpose of which is to remove the disruptive coating agent mist (“overspray”) from the painting booth. This air flow is usually switched off during a painting process. Instead, air is then introduced into the paint booth via the filter ceiling and via the atomizing air (e.g. drive air, brake air, steering air and bearing air), which is emitted by the atomizer. The downward-directed air flow is therefore preferably controlled by the control unit in the painting breaks in such a way that the same amount of air is introduced into the painting booth during the painting breaks as during a painting process.

It should also be mentioned that different air flows can be introduced into the painting booth, namely, on the one hand, the air flow from the conventional filter cover and on the other hand, the air flow from an additional nozzle arrangement. The air flow from the additional nozzle arrangement is preferably controllable and is preferably only switched on during painting breaks. The additional nozzle arrangement is preferably branched off from the air supply to the filter ceiling. The result of this is that compressed air delivery from the additional nozzle arrangement leads to a correspondingly reduced delivery of compressed air from the filter ceiling. As a result, the total air balance is not changed, ie the amount of air introduced into the painting booth remains at least approximately the same, as a result of which undesired air flows in the painting booth are reduced or avoided entirely.

In addition, the invention preferably provides that at least 70% of the total sink air (i.e., the downward air flow) should be introduced into the paint booth between two successive bodies (i.e. between the rear of the leading body and the front of the following body). This makes sense so that the following body is not contaminated by the remaining coating agent mist ("overspray") of the previous body.

Figur 1

eine vereinfachte Perspektivansicht einer Lackieranlage mit einem zusätzlichen Roboter zur Entfernung von störendem Beschichtungsmittelnebel ("Overspray"),

Figur 2A

eine vereinfachte Perspektivansicht eines anderen Ausführungsbeispiels einer erfindungsgemäßen Lackierkabine mit einem modifizierten Handhabungsroboter zur Entfernung des störenden Beschichtungsmittelnebels,

Figur 2B

eine perspektivische Großansicht des modifizierten Handhabungsroboters,

Figur 3

eine vereinfachte Perspektivansicht eines weiteren Ausführungsbeispiels einer erfindungsgemäßen Lackierkabine mit einem SCARA-Roboter zur Entfernung des störenden Beschichtungsmittelnebels,

Figur 4

eine vereinfachte Perspektivansicht einer erfindungsgemäßen Lackierkabine, wobei ein herkömmlicher Applikationsroboter Lenkluft appliziert, um den störenden Beschichtungsmittelnebel zu entfernen,

Figur 5

ein Flussdiagramm zur Verdeutlichung einer Variante des erfindungsgemäßen Betriebsverfahrens,

Figuren 6A-6C

verschiedene Stadien des Einförderns bzw. Ausförderns der Kraftfahrzeugkarosseriebauteile bei dem Betriebsverfahren gemäß Figur 5,

Figur 7

ein Diagramm zur Verdeutlichung der unterschiedlichen Beschleunigungen beim Einfördern bzw. Ausfördern aus der Lackierkabine,

Figuren 8A-8C

verschiedene Stadien des Ausförderns einer Kraftfahrzeugkarosserie aus der Lackierkabine,

Figur 9

eine schematische Darstellung einer nicht erfindungsgemäßen Lackierkabine mit einer Filterdecke, die eine abwärts gerichtete Luftströmung in die Lackierkabine abgibt, wobei die Luftströmung in Förderrichtung angewinkelt ist,

Figuren 10A und 10B

zwei Perspektivansichten einer Blasdüsenanordnung mit einem schwenkbaren Rahmen, wobei die Blasdüsenanordnung in der Lackierkabine eine Luftströmung nach unten abgibt, um den Overspray zu entfernen, sowie

Figuren 11A und 11B

eine Perspektivansicht einer Abwandlung der Blasdüsenanordnung gemäß den Figuren 10A und 10B, wobei die Blasdüsenanordnung linear verfahrbar ist.

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 exemplary embodiments of the invention with reference to the figures. Show it:

Figure 1

a simplified perspective view of a painting system with an additional robot for removing disruptive coating agent mist ("overspray"),

Figure 2A

1 shows a simplified perspective view of another exemplary embodiment of a painting booth according to the invention with a modified handling robot for removing the disruptive coating agent mist,

Figure 2B

a large perspective view of the modified handling robot,

Figure 3

2 shows a simplified perspective view of a further exemplary embodiment of a painting booth according to the invention with a SCARA robot for removing the disruptive coating agent mist,

Figure 4

2 shows a simplified perspective view of a painting booth according to the invention, a conventional application robot applying steering air in order to remove the disruptive coating agent mist,

Figure 5

2 shows a flowchart to illustrate a variant of the operating method according to the invention,

Figures 6A-6C

different stages of the infeed or outfeed of the motor vehicle body components according to the operating method Figure 5 ,

Figure 7

a diagram to illustrate the different accelerations when feeding in or out from the painting booth,

Figures 8A-8C

different stages of the removal of a motor vehicle body from the paint booth,

Figure 9

1 shows a schematic illustration of a painting booth not according to the invention with a filter ceiling, which emits a downward air flow into the painting booth, the air flow being angled in the conveying direction,

Figures 10A and 10B

two perspective views of a blower nozzle arrangement with a pivotable frame, the blower nozzle arrangement in the spray booth emitting a downward air flow to remove the overspray, and

Figures 11A and 11B

a perspective view of a modification of the blow nozzle assembly according to the Figures 10A and 10B , wherein the blowing nozzle arrangement is linearly movable.

Figure 1 shows an embodiment of a paint booth 1 according to the invention in a paint shop for painting motor vehicle body components 2, the motor vehicle body components 2 being conveyed through the paint booth 1 by a conventional conveyor 3 on transport racks 4 (“skids”).

The painting of the motor vehicle body components 2 in the painting booth 1 is carried out by multi-axis application robots, which can be of conventional design and are not shown for simplification.

It should also be mentioned that the painting booth 1 has a conventional filter ceiling, which generates a largely laminar, downward air flow in the interior of the painting booth 1 in order to press down excess coating agent mist (“overspray”) in the booth space and then through the grating to promote trained cabin floor in a washout, the filter cover and the washout can be of conventional design and are therefore also not shown.

The conveying device 3 conveys the motor vehicle body components 2 in stop-and-go operation through the painting booth 1. This means that the motor vehicle body components 2 stand still in the coating position shown in the drawing and are therefore braked during conveying and accelerated during conveying out. The acceleration of the motor vehicle body components 2 when conveying out of the painting booth 1 is problematic in two respects.

On the one hand, the painting of the motor vehicle body components 2 also produces an excess coating agent mist in the interior thereof, in particular when interior surfaces of the motor vehicle body components 2 are painted. This coating agent mist in the interior of the motor vehicle body components 2 is shielded from the roof of the motor vehicle body components 2 from the downward air flow generated by the filter ceiling and therefore remains in the interior of the vehicle body components 2 for a relatively long time through the tailgate from the motor vehicle body component 2 in the Interior of the painting booth, which can impair the next painting process.

On the other hand, the relatively abrupt acceleration of the motor vehicle body components 2 produces air vortices in the interior of the cabin when it is being conveyed out of the painting booth, as a result of which the excess coating agent mist can remain in the cabin for longer.

In order to remove the excess coating agent mist from the cabin interior of the painting booth 1, a manipulator 5 is therefore additionally provided in this exemplary embodiment, which can be moved on a travel rail 6 on the cabin ceiling, parallel to the conveying device 3, i. H. in the X direction indicated by a double arrow.

The manipulator 5 carries at its lower end a nozzle bar 7 which is aligned horizontally and at right angles to the conveyor 3. The nozzle bar 7 has numerous air nozzles distributed over its length, which emit an air jet 8 in order to remove the coating agent mist as quickly as possible from the interior of the painting booth 1.

The manipulator 5 enables the nozzle bar 7 to be raised or lowered in the vertical direction, i. H. in the Z direction indicated by a double arrow.

It should also be mentioned that the exit direction of the air jet 8 is angled relative to the vertical by an angle α = 15 ° -45 ° in the conveying direction of the conveying device 3. The air jet 8 blows the from the tailgate Excess coating agent mist emerging from the motor vehicle body component 2 that is conveyed out thus obliquely away from the front at the bottom, whereby the removal of the coating agent mist from the cabin interior of the painting cabin 1 can be accelerated.

When the motor vehicle body component 2 is conveyed out of the painting booth 1, the manipulator 5 is moved with the nozzle bar 7 along the travel axis 6 on the cabin ceiling, so that the distance between the nozzle bar 7 and the tailgate of the motor vehicle body component 2 being conveyed remains essentially constant during the conveying out. The manipulator 5 thus has a specific cleaning area which lies in front of the manipulator 5 in the conveying direction and in which the excess coating agent mist is removed particularly effectively. The movement of the manipulator 5 when the motor vehicle body component 2 is being conveyed out is here synchronized with the movement of the motor vehicle body component 2, so that the cleaning area of the manipulator 5 is always located just behind the tailgate of the motor vehicle body component 2 that is conveyed out, which contributes to effective cleaning.

The Figures 2A and 2 B show a modification of the embodiment according to Figure 1 , so that to avoid repetition reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this exemplary embodiment is that the manipulator 5 for removing the disruptive coating agent mist from the interior of the painting booth 1 is a handling robot, with the travel rail 6 being used for the method of the manipulator 5 is arranged on the cabin floor laterally next to the conveyor 3.

The manipulator 5 is designed as a multi-axis articulated arm robot and has a robot base 9, a rotatable robot member 10, a proximal robot arm 11, a distal robot arm 12, a robot hand axis 13 and a handling tool 14. The structure of the manipulator 5 as a handling robot is known per se from the prior art and therefore need not be described in more detail. However, the manipulator 5 is modified here by a nozzle bar 15 which is attached to the distal robot arm 12 and extends in the longitudinal direction of the distal robot arm 12. The nozzle bar 15 has a plurality of air nozzles 16 which are arranged equidistantly along the length of the nozzle bar 15. The individual air nozzles 16 can each emit an air jet 8, which is shown as an arrow for illustration. When the disruptive coating agent is removed, the proximal robot arm 12 with the nozzle bar 15 is aligned essentially horizontally and at right angles to the conveying device 3 and is arranged behind the tailgate of the motor vehicle body component 2 to be conveyed out. The individual air nozzles 16 then emit the air jet 8 obliquely towards the front downwards, as a result of which the coating agent mist emerging from the tailgate of the motor vehicle body component 2 to be conveyed out is pressed downward, which contributes to a rapid removal of the coating agent mist from the interior of the painting cabin 1.

When the motor vehicle body component 2 is conveyed out of the cabin interior of the painting booth 1, the manipulator 5 on the travel rail 6 then becomes synchronous with the motor vehicle body component 2 moves, which contributes to a good cleaning effect.

Figure 3 shows a modification of the embodiment according to the Figures 2A and 2 B , so that to avoid repetition reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this embodiment is that the manipulator 5 as a SCARA robot (SCARA: elective S C ompliance A ssembly R obot A rm) is formed.

Figure 4 shows a modification of the embodiment according to the Figures 2A and 2 B , so that to avoid repetition reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this exemplary embodiment is that the manipulator 5 for removing the annoying coating agent mist is an application robot which, as an application device, guides a rotary atomizer 17 with a steering air ring.

In the paint application, the rotary atomizer 17 then emits a spray jet of the paint to be applied, the steering air ring emitting steering air in order to form the spray jet of the coating agent.

To remove the disruptive coating agent mist, the spray jet of the lacquer is then switched off and the rotary atomizer 17 only delivers steering air via its steering air nozzles in order to push away the annoying spray jet mist.

Figure 5 shows a flow diagram of a variant of the operating method according to the invention, the Figures 6A to 6C show different stages during the operating process.

In the Figures 6A-6C spray jets of the coating agent are shown with solid lines, while air jets for removing the disruptive coating agent mist are drawn as a dotted line.

Figure 6A First shows an initial state in which the motor vehicle body component 2 is located in the painting booth 1 and there is coated with paint by several rotary atomizers 17-19. The rotary atomizers 17-19 are guided in the usual manner by multi-axis application robots, the application robots not being shown for the sake of simplicity. Here, the motor vehicle body component 2 is in a final coating position, in which the motor vehicle body component 2 can be completely coated. The next motor vehicle body component 20, which is then to be painted, is already waiting in front of the painting booth 1.

In a step S1, the motor vehicle body component 2 is then conveyed out of the paint booth 1 until the motor vehicle body component 2 is located behind the paint booth 1 in the conveying direction, as in FIG Figure 6B is shown.

The next motor vehicle body component 20 is then conveyed into the painting booth 1 in a step S2. However, the motor vehicle body component 20 is initially not conveyed up to the final coating position in the middle of the painting booth 1, but only to a pre-position that in Figure 6B is shown.

In the preposition of the motor vehicle body component 20, a front region (for example bonnet, front fenders) of the motor vehicle body component 20 is then first painted in a step S3, for which purpose the rotary atomizer 17 is used.

The other two rotary atomizers 18, 19 then apply no paint, but only compressed air via the steering air nozzles, in order to remove a disruptive coating agent mist 21 from the painting booth 1 in a step S4.

After removal of the disruptive coating agent mist 21, the motor vehicle body component 20 is then moved from the preposition in a step S5 Figure 6B according to the final painting position Figure 6C promoted.

In this final painting position, the component surface of the motor vehicle body component 20 is then painted in the remaining surface areas (e.g. trunk lid, roof, doors, rear fenders) in a step S6, for which purpose all rotary atomizers 17-19 can be used.

Figure 7 shows a diagram to illustrate the acceleration of the motor vehicle body components 2 from the painting booth 1 to the immediately following painting booth 22. Between a standstill point 23 in the painting booth 1 and the next standstill point 24 in the painting booth 22, the motor vehicle body component 2 is first along an acceleration ramp 25 with an acceleration a1 accelerates and then decelerated along a deceleration ramp 26 with a deceleration a2.

The diagram shows that the acceleration a1 on the acceleration ramp 25 is significantly less than the deceleration a2 on the deceleration ramp. The relatively small acceleration a1 is advantageous because less air turbulence then occurs when the motor vehicle body component 2 is conveyed out of the painting booth 1, so that the disruptive coating agent mist then settles or is removed more quickly.

The Figures 8A-8C show different stages when the motor vehicle body component 2 is being conveyed out of the painting booth 1, a cleaning area 27 being shown in broken lines. The cleaning area 27 is the area within the painting booth 1 in which the air flow according to the invention leads to a rapid removal of the disruptive coating agent mist. It can be seen from the drawings that the cleaning area 27 is moved in synchronism with the removed motor vehicle body component 2 when the motor vehicle body component 2 is conveyed out of the painting booth 1. This is advantageous because when the motor vehicle body component 2 is conveyed out of the painting booth 1, the disruptive coating agent mist just behind the motor vehicle body component 2 is particularly intense, since the coating agent mist can escape from the rear window of the motor vehicle body component 2 there.

Figure 9 shows a modification of a painting booth 1 not according to the invention, which partially corresponds to the exemplary embodiments described above, so that reference is made to the above description in order to avoid repetition the same reference numerals are used for corresponding details.

A filter cover 28 is also shown here, which can be largely conventional and emits a downward air flow into the painting booth 1 in order to press the disruptive coating agent mist (“overspray”) downward.

The filter cover 28 here has a nozzle element 29 which is arranged in the rear part of the painting booth 1 with respect to the conveying direction and which emits the air flow obliquely towards the bottom at the front. The air stream emerging from the nozzle element 29 is therefore not oriented exactly vertically downward, but is inclined in the conveying direction, for example at an angle of 45 ° to the vertical. The disruptive coating agent mist ("overspray") is thereby not only pressed down, but also blown away from the inlet of the painting booth 1. This prevents the next motor vehicle body component 2 from being contaminated by the interfering coating agent mist (“overspray”) of the preceding motor vehicle body component 2.

In addition, a blow column 30 is arranged at the inlet end of the painting booth 1, which emits an air flow in the conveying direction into the painting booth. As a result, the disruptive coating agent mist (“overspray”) is also blown away from the inlet of the painting booth 1 in order to avoid contamination of the next motor vehicle body component 2.

The blow column 30 here has a plurality of air nozzles at different heights. With increasing height of the air nozzles, the air nozzles are angled downward more and more thus give off an air flow that is oriented more downward. The bottom air nozzle of the blow column 30 is aligned almost exactly horizontally, while the upper air nozzles are inclined more downward. This inclination of the upper air nozzles optimizes the removal of the annoying coating agent mist.

The Figures 10A and 10B show different states of motion of a blowing nozzle arrangement 31 according to the invention, which can be used in a painting booth to emit a downward air flow from top to bottom into the painting booth in order to blow down the disruptive coating agent mist (“overspray”). The downward air flow is indicated in the drawings by arrows.

The blowing nozzle arrangement 31 has a pivotable frame 32 which is pivotable about an axis of rotation 33, the axis of rotation 33 running through a frame edge of the frame 32.

On the opposite frame edge of the frame 32 a slot-shaped blowing nozzle 34 is attached, which emits the downward air flow. In this case, a lever construction ensures that the blowing nozzle 34 is always oriented downward regardless of the movement position of the frame 32.

The pivoting movement of the frame 32 is driven by a cable drive, the cable drive having four pull cables 35-38 and four rollers 39-42.

The air flow emitted by the blowing nozzle 34 presses the overspray in the paint booth down through the grid floor the painting booth, as has already been described in detail above.

The Figures 11A and 11B show a modification of the blowing nozzle arrangement 31 according to FIGS Figures 10A, 10B . This modification according to the Figures 11A, 11B largely agrees with the blowing nozzle arrangement 31 according to FIGS Figures 10A, 10B agree, so that to avoid repetition reference is made to the above description, the same reference numerals being used for corresponding details.

A special feature of this exemplary embodiment is that the blowing nozzle 34 cannot be pivoted, but rather can be displaced linearly, namely parallel to the conveying direction, the direction of displacement of the blowing nozzle 34 being indicated in the drawings by a double arrow. Here, too, the blowing nozzle 34 is driven by a cable drive 43.

Reference symbol list:

1

Paint booth

2nd

Motor vehicle body component

3rd

Conveyor

4th

Transport frame ("skid")

5

manipulator

6

Traversing axis of the manipulator

7

Manipulator nozzle bar

8th

Air jet

α

Angle of the air jet to the vertical

9

Robot base

10th

Rotatable robot link

11

Proximal robot arm of the handling robot

12th

Distal robotic arm of the handling robot

13

Robotic hand axis of the handling robot

14

Handling tool

15

Nozzle bar

16

Air vents

17-19

Rotary atomizer

20th

Motor vehicle body component

21

Coating agent mist

22

Paint booth

23

Standstill

24th

Standstill

25th

Acceleration ramp

26

Deceleration ramp

27

Cleaning area

28

Filter cover

29

Nozzle element

30th

Blow column

31

Blow nozzle arrangement

32

frame

33

Axis of rotation

34

Blow nozzle

35-38

Traction ropes

39-42

roll

α

Angle between the air jet and the vertical

a1

Acceleration when conveying out of the paint booth

a2

Delay in feeding into the painting booth

s

Path along the conveyor

v

Conveyor speed

Claims (15)

1. Operating method for a coating system, in particular for a painting system, for coating components (2), in particular motor vehicle body components (2), having the following steps:

   a) conveying the components (2) to be coated in a conveying direction through a coating booth (1) by means of a conveyor (3),

   b) coating the components (2) in the coating booth (1) with a coating agent by means of an applicator (17-19) which applies a spray jet of the coating agent, a portion of the applied coating agent being deposited on the components (2) to be coated, while another portion of the applied coating agent initially floats in the booth interior of the coating booth (1) as disturbing overspray (21),

   c) removing the disturbing excessive overspray (21) from the booth interior by a vertically downwardly directed air flow that is generated by a filter ceiling, and

   d) removing the disturbing excessive overspray (21) from the booth interior by an additional measure in addition to the removal of the overspray by the vertically downwardly directed air flow that is generated by a filter ceiling, wherein the additional measure provides that an air stream is generated by a blowing nozzle arrangement (31),

   characterized in that

   e) the blowing nozzle arrangement (31) delivers the air flow downwards through at least one blowing nozzle (34) in order to blow the troublesome overspray downwards out of the booth interior, and

   f) the blowing nozzle arrangement (31) is movable in the conveying direction.
2. Operating method according to claim 1,
   characterised in that

   a) the blowing nozzle arrangement (31) is arranged above the conveyor, in particular on a ceiling of the coating booth or on a gantry, and/or

   b) the blowing nozzle arrangement (31) extends through the coating booth transversely to the conveying direction, and/or

   c) a cable drive (35-42; 43) is provided for moving the blowing nozzle arrangement (31).
3. Operating method according to claim 2,
   characterised in that

   a) the blowing nozzle arrangement (31) is pivoted about an axis of rotation (33) transversely to the conveying direction, and/or

   b) the blowing nozzle (34) is at a distance from the axis of rotation (33) so that the blowing nozzle (34) executes a curved movement when the blowing nozzle arrangement (31) performs a pivoting movement, and/or

   c) the blowing nozzle arrangement (31) holds the blowing nozzle (34) in a constant angular orientation relative to the vertical, in particular vertically downwards, during a pivoting movement, so that the blowing nozzle (34) delivers the air flow vertically downwards, and/or

   d) the blowing nozzle arrangement (31) has a pivotable frame (32) which is pivoted about the axis of rotation (33), the axis of rotation (33) running through one frame edge while the blowing nozzle (34) is mounted on the opposite frame edge.
4. Operating method according to claim 2, characterised in that the blowing nozzle arrangement (31) has a linear displacement axis which runs parallel to the conveying direction, so that the blowing nozzle (34) is displaceable in the conveying direction.
5. Operating method according to any one of the preceding claims, characterised in that

   a) when the components (20) to be coated are conveyed into the coating booth (1), they are first conveyed into a preliminary position in the coating booth (1) which is situated upstream in the conveying direction of a final coating position in the coating booth (1),

   b) the overspray (21) from a preceding coating operation is removed in the region of the final coating position while the next component (20) is in the preliminary position,

   c) the components (20) to be coated are coated in the preliminary position only in their front region, for example on an engine bonnet or front wings, and

   d) the components (20) are conveyed from the preliminary position into the final coating position when the overspray (21) has been removed in the region of the final coating position and the component (20) in the preliminary position has been coated in the front region, and/or

   e) the components (20) are then coated in the final coating position also outside the front region.
6. Operating method according to any one of the preceding claims, characterised in that

   a) as one of the components (2) is being discharged from the coating booth (1), overspray (21) escapes from the component (2) and/or is swirled up by the discharged component (2), and

   b) removal of the overspray (21) is spatially concentrated in a cleaning region (27) which does not include the entire booth interior,

   c) the cleaning region (27) includes at least a portion, in particular a rear portion relative to the conveying direction, of the discharged component (2),

   d) as the component (2) is discharged from the coating booth (1), the cleaning region (27) is preferably moved in the conveying direction synchronously with the component (2).
7. Operating method according to any one of the preceding claims, characterised in that

   a) the components (2) to be coated are conveyed through the coating booth (1) in stop-and-go operation, in particular with a conveying time of less than 13 s, 11 s or 9 s, and/or

   b) as the components (2) to be coated are discharged from the coating booth (1), they are first accelerated with a specific acceleration (a1) and then braked again with a specific deceleration (a2), and/or

   c) during discharge from the coating booth (1), the acceleration (a1) is lower than the following deceleration (a2), in particular in order to swirl up less overspray (21) during acceleration.
8. Coating system, in particular painting system, for coating components (2), in particular motor vehicle body components, having

   a) a coating booth (1),

   b) a conveyor (3) for conveying the components (2) through the coating booth (1),

   c) at least one applicator (17-19) inside the coating booth (1) for applying a spray jet of a coating agent to the components (2) to be coated, a portion of the applied coating agent being deposited on the components (2) to be coated, while another portion of the applied coating agent (2) floats in the booth interior as overspray (21),

   d) a cleaning device (5) for removing the overspray (21) from the booth interior by a vertically downwardly directed air flow that is generated by a filter ceiling,

   e) wherein the cleaning device (5) comprises a blowing nozzle arrangement (31) in addition to the filter ceiling,

   characterised in that

   f) the blowing nozzle arrangement (31) delivers an air flow downwards through at least one blowing nozzle (34) in order to blow the troublesome overspray downwards out of the booth interior, and

   g) the blowing nozzle arrangement (31) is movable in the conveying direction
9. Coating system according to claim 8,
   characterised in that

   a) the blowing nozzle arrangement (31) is arranged above the conveyor, in particular on a ceiling of the coating booth or on a gantry, and

   b) the blowing nozzle arrangement (31) extends through the coating booth transversely to the conveying direction, and

   c) a cable drive (35-42; 43) is provided for moving the blowing nozzle arrangement (31).
10. Coating system according to claim 9,
    characterised in that

    a) the blowing nozzle arrangement (31) is pivotable about an axis of rotation (33) transversely to the conveying direction, and

    b) the blowing nozzle (34) is at a distance from the axis of rotation (33) so that the blowing nozzle (34) executes a curved movement when the blowing nozzle arrangement (31) performs a pivoting movement, and

    c) the blowing nozzle arrangement (31) holds the blowing nozzle (34) in a constant angular orientation relative to the vertical, in particular vertically downwards, during a pivoting movement, so that the blowing nozzle (34) delivers the air flow vertically downwards, and

    d) the blowing nozzle arrangement (31) has a pivotable frame (32) which is pivotable about the axis of rotation (33), the axis of rotation (33) running through one frame edge while the blowing nozzle (34) is mounted on the opposite frame edge.
11. Coating system according to claim 9, characterised in that the blowing nozzle arrangement (31) has a linear displacement axis which runs parallel to the conveying direction, so that the blowing nozzle (34) is displaceable in the conveying direction.
12. Coating system according to any one of claims 8 to 11,
    characterised in that

    a) when the components (20) to be coated are conveyed into the coating booth (1), they are first conveyed into a preliminary position in the coating booth (1) which is situated upstream in the conveying direction of a final coating position in the coating booth (1),

    b) the overspray (21) from a preceding coating operation is removed in the region of the final coating position while the next component (20) is in the preliminary position,

    c) the components (20) to be coated are coated in the preliminary position only in their front region, for example on an engine bonnet or front wings, and

    d) the components (20) are conveyed from the preliminary position into the final coating position when the overspray (21) has been removed in the region of the final coating position and the component (20) in the preliminary position has been coated in the front region, and

    e) the components (20) are then coated in the final coating position also outside the front region.
13. Coating system according to any one of claims 8 to 12,
    characterised in that

    a) as one of the components (2) is being discharged from the coating booth (1), overspray (21) escapes from the component (2) and/or is swirled up by the discharged component (2), and

    b) removal of the overspray (21) is spatially concentrated in a cleaning region (27) which does not include the entire booth interior,

    c) the cleaning region (27) includes at least a portion, in particular a rear portion relative to the conveying direction, of the discharged component (2),

    d) as the component (2) is discharged from the coating booth (1), the cleaning region (27) is preferably moved in the conveying direction synchronously with the component (2).
14. Coating system according to any one of claims 8 to 13,
    characterised in that

    a) the components (2) to be coated are conveyed through the coating booth (1) in stop-and-go operation, in particular with a conveying time of less than 13 s, 11 s or 9 s, and

    b) as the components (2) to be coated are discharged from the coating booth (1), they are first accelerated with a specific acceleration (a1) and then braked again with a specific deceleration (a2), and

    c) during discharge from the coating booth (1), the acceleration is lower than the following deceleration, in particular in order to swirl up less overspray (21) during acceleration.
15. Coating system according to any one of claims 8 to 14,
    characterised in that

    a) the coating system has a control unit which controls the downwardly directed air flow, and

    b) the control unit switches on or increases the downwardly directed air flow in breaks in painting and switches off or decreases the downwardly directed air flow during a painting operation, and

    c) the control unit determines the quantity of air which is introduced into the painting booth during a painting operation, preferably including:

    c1) shaping air for shaping the spray jet,

    c2) driving air for driving a compressed air turbine of a rotary atomiser,

    c3) braking air for braking the compressed air turbine of the rotary atomiser, and/or

    c4) bearing air for supplying an air bearing of the rotary atomiser, and/or

    d) the control unit controls the downwardly directed air flow during a break in painting in such a manner that, during a break in painting, substantially the same quantity of air is introduced into the painting booth, via the downwardly directed air flow, as during a painting operation, in particular with a difference of less than ±50%, ±40%, ±30%, ±20%, ±10%, ±5% or ±1%.

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