Coating booth for coating workpieces with coating material

Abstract

[0001] Die Erfindung betrifft eine Beschichtungskabine (1) zum Beschichten von Werkstücken mit Beschichtungsmaterial, insbesondere mit Beschichtungspulver, wobei der Beschichtungskabine (1) eine Kabinenabsaugung zugeordnet ist zum insbesondere bedarfsweisen Absaugen von bei einem Beschichtungsvorgang anfallendem überschüssigen Beschichtungsmaterial, wobei die Beschichtungsmaterialabsaugung mindestens einen vertikal verlaufenden Absaugkanal (2) aufweist, der strömungsmäßig mit einem Beschichtungsmaterial-Abscheidersystem (3; 3.1, 3.2) verbunden oder verbindbar ist. Erfindungsgemäß ist insbesondere vorgesehen, dass der vertikal verlaufende Absaugkanal (2) über zwei vertikal verlaufende Schlitzöffnungen (4) mit einem Beschichtungsbereich (5) der Beschichtungskabine (1) in Fluidverbindung steht, wobei ein effektiver Strömungsquerschnitt der mit den beiden vertikal verlaufenden Schlitzöffnungen (4) bereitgestellten Fluidverbindung in vertikaler Richtung des Absaugkanals (2) insbesondere stetig variiert.

Description

[0001] The invention relates generally to the field of coating workpieces with coating material, such as coating powder or coating material in liquid form, such as paint.

[0002] According to aspects of the invention, this relates in particular to a coating system for coating a workpiece and a method for operating such a coating system.

[0003] The coating system is suitable, for example, for coating workpieces with coating powder. However, the present invention is not limited to coating systems or coating booths used for coating workpieces with powdered coating material. Rather, the invention also relates to corresponding systems or coating booths for coating workpieces with coating powder.

[0004] A coating system of the type described herein typically comprises a booth (coating booth) with side walls through which one or more powder spray guns protrude into the interior of the booth. The workpiece to be coated is usually transported through the coating booth on a conveyor belt, for example, suspended from the floor, and is sprayed with powder by the powder spray guns. The workpiece is then transported into a heating chamber. In the heating chamber, the powder layer is heated to the point where it liquefies and forms a continuous layer on the workpiece.

[0005] Coating booths for coating workpieces, especially with coating powder, are generally known from the prior art. Such coating booths typically have a coating chamber with a booth floor, two opposing workpiece passages, and a conveyor device for transporting workpieces through the coating chamber.

[0006] For example, the publication EP 0 071 756 A2 relates to a coating booth with a conveying system that transports the items to be coated through an entrance and an exit within the booth. A spraying unit in the booth is a wall element with a hand-held spray gun, accessible via doors. However, automatically controlled spray guns can also be used. The doors also allow access to the interior of the booth. The spraying units with the spray guns can all be located on the same side of the booth. Alternatively, spraying units in the form of pre-cut wall elements with slots for inserting the guns can be provided on the opposite side.

[0007] Instead of a conveyor system for the automatic transport of the items to be coated through the interior of the cabin, the items to be coated can also be manually placed into the interior of the cabin and removed again after a coating process.

[0008] The conveying device for the automatic transport of the items to be coated through the interior of the cabin can also be arranged below the floor of the coating cabin and have a workpiece carrier which protrudes into the coating chamber of the coating cabin through a conveying slot in the floor of the cabin.

[0009] Coating booths with such "floor conveyors" are used particularly for coating high-quality workpieces, as the arrangement of the conveyor system below the booth floor allows for a high level of coating quality. This is primarily because "classic" conveyors for the suspended transport of workpieces through the coating chamber can encourage dirt particles or powder residue to fall from the conveyor system, which can lead to irregularities in the coating.

[0010] On the other hand, booths or systems for discontinuous workpiece transport during manual coating are also known, particularly for powder coating. This type of booth differs from continuous-feed booths, which are designed for continuous workpiece transport during manual and / or automatic coating. Which of these basic types is used depends essentially on the scope of the respective coating task, i.e., the order to be carried out by the coater.

[0011] The publication EP 1 256 386 A2 concerns a booth for powder coating workpieces. A manual coating area is located both in front of and behind the booth to allow for manual coating of the workpiece. Therefore, if small batches are to be coated with other materials or colors, the booth and the powder recovery system must first be cleaned. To clean the booth, a sliding door located between the manual coating area and the booth is first closed. Then, the powder inside the booth is manually removed, and the door is subsequently reopened. This process is relatively complex, time-consuming, and not always practical.

[0012] On the other hand, US Patent 5,078,084 A discloses a system for coating large workpieces, such as vehicle parts, with powder. This system is designed to ensure uniform coating of the entire vehicle body and to collect and recover a large portion of the excess powder. The system includes an automatic spraying area and a manual coating area. All excess powder, i.e., both the excess powder from the automatic spraying area and the excess powder extracted from the manual coating area, is fed into a cyclone separator.

[0013] The publication EP 2 879 807 B1 relates to a coating booth according to the preamble of independent claim 1.

[0014] The publication EP 2 275 209 A1 relates to a booth for coating workpieces with powder, wherein the booth has an extraction duct with an extraction opening for extracting excess powder, as well as a tray and a roller arranged therein. The tray and the roller form the extraction duct and the extraction opening. The roller is rotatably mounted.

[0015] Document WO 1999 / 12658 A1 also concerns a coating booth for powder coating objects.

[0016] Document US 2013 / 061886 A1 concerns another coating booth for powder coating objects.

[0017] The publication DE 10 2020 113 645 A1 concerns a coating booth or coating cell of a coating system optimized for coating workpieces.

[0018] Document US 2003 / 127047 A1 concerns a coating booth with blow-off strips.

[0019] Conventional coating booths known from the prior art generally have a substantially rectangular shape in horizontal cross-section. These elongated coating booths have openings or doors, so-called workpiece passages, at their narrow end walls, which serve to transport workpieces through the booth using a transport device. Furthermore, the side walls of these known coating booths typically have openings or vertical slots for inserting hand-held or automatic spray guns into the booth, with which the workpieces transported through the coating booth can be coated.

[0020] In known spray booths, most of the sprayed excess powder that does not adhere to the workpiece falls onto the booth floor. This excess powder can be extracted from the booth floor and separated from the exhaust airflow by means of powder separation, in particular using a cyclone separator and / or filter elements, before being fed back to the spraying devices. Horizontally oriented extraction slots are typically provided in the booth floor for extracting the excess powder.

[0021] When changing powder types, for example, to a different color, not only must all interior surfaces of the booth be cleaned extremely thoroughly, but also the cyclone separators and filter systems used for powder recovery, as well as the powder lines, to prevent any powder particles from the first powder used from mixing with the powder used afterward. Even a single powder particle can lead to coating defects on the workpiece, rendering the coating unusable.

[0022] While recovering excess powder reduces the operating costs of the coating booth, the problem remains that changing the powder or color requires a significant amount of time to clean the components, resulting in long downtimes for the system. This makes it clear that for multi-color coatings, and especially when objects are to be coated with different colors, the aforementioned spray coating operation with excess powder recovery becomes unprofitable and must be run at a loss. "Running at a loss" means that the excess powder is not processed and reused, but rather discarded as waste, since the more powder accumulates in the booth and on other parts, the more difficult and time-consuming the cleaning process becomes.

[0023] The present invention addresses the problem that conventional coating booth designs, in which excess powder is removed by means of a floor extraction system, are only suitable for relatively low booth heights of a maximum of 2.5 to 3 m. Above a certain booth height, the floor extraction system becomes ineffective, particularly in the upper areas of the booth, resulting in powder spillage.

[0024] Another problem with the coating booths known from the prior art and described at the beginning is that they are generally not readily suitable for so-called robotic operation, in which one or more coating robots are positioned outside the coating booth, operating corresponding automatic spray guns. Such coating robots require a relatively large freedom of movement, since the robot arm must be used to guide the at least one automatic spray gun attached to it, preferably completely, around the workpiece to be coated.

[0025] The use of coating robots in conventional coating booths is therefore not possible, or at least not without difficulty, since conventional coating booths usually only have relatively small slot openings in the wall elements through which the coating guns are guided.

[0026] Based on this problem, the invention aims to further develop a coating booth for coating, in particular powder coating, workpieces in such a way that, firstly, the coating booth is suitable for robot operation, while simultaneously reducing the time required for color or powder changes without compromising coating quality. The invention is specifically intended to effectively prevent the deposition of powder residue in the booth and on other parts, even in coating booths with relatively high ceilings, particularly those exceeding 2.5 to 3 meters.

[0027] The problem underlying the invention is solved in particular by the subject matter of independent claim 1.

[0028] Accordingly, the invention relates in particular to a coating booth for coating workpieces with coating material, especially with coating powder, wherein the coating booth is associated with a booth extraction system for the extraction, in particular as required, of excess coating material generated during a coating process. The coating material extraction system has at least one vertically extending extraction channel which is or can be connected to a coating material separator system.

[0029] According to the invention, it is particularly provided that the vertically extending extraction channel is in fluid contact with a coating area of ​​the coating booth via two vertically extending slot openings, wherein an effective flow cross-section of the fluid connection provided by the two vertically extending slot openings varies continuously in the vertical direction of the extraction channel.

[0030] Because the coating booth according to the invention is designed so that the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings varies continuously in the vertical direction of the extraction duct, a particularly homogeneous extraction airflow can be achieved within the booth. This ensures that excess coating material can be reliably removed from the interior of the booth, even at relatively high booth heights. The extraction airflow achieved with the two vertically extending slot openings also prevents excess coating material from escaping the coating chamber. Instead, the extraction airflow even at least partially removes coating material sprayed outside the coating booth, as is the case, for example, in a manual coating station.

[0031] According to a preferred embodiment of the coating booth according to the invention, the extraction channel has a first end region and an opposing second end region, wherein the extraction channel is fluidically connected to an extraction device via one of the two end regions. It is particularly provided that the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings decreases, in particular continuously, in the direction of one of the two end regions of the extraction channel, via which the extraction channel is fluidly connected to the extraction device.

[0032] This design makes it possible for the amount of excess coating material extracted per unit of time through the two vertically running slot openings to remain constant when viewed in the vertical direction.

[0033] In a particularly easy-to-implement yet effective design variant, it is provided that the two vertically running slot openings each have the shape of a triangle, in particular the shape of a right-angled triangle.

[0034] According to a further aspect of the invention, this relates to a coating booth for coating workpieces with coating material, in particular with coating powder, wherein the coating booth is assigned a booth extraction system for the extraction of excess coating material generated during a coating process, particularly as required, wherein the coating material extraction system has at least one vertically extending extraction channel which is or can be connected to a coating material separator system in terms of flow.

[0035] In this (further) aspect of the invention, it is particularly provided that the vertically extending extraction channel is in fluid communication with a coating area of ​​the coating chamber via two vertically extending slot openings, wherein an effective flow cross-section of the fluid connection provided by the two vertically extending slot openings is variably adjustable.

[0036] In particular, the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings can be adjusted to a first value, which is adapted to a coating operation of the coating booth, and to a second value, which is larger than the first value and is adapted to a cleaning operation of the coating booth.

[0037] In this embodiment of the coating booth according to the invention, uniform laminar extraction can be achieved throughout the entire height of the booth during coating operation, and this extraction is selected so as not to disrupt the coating process. However, if, for example, the coating booth needs to be cleaned during a color change, the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings can be adjusted to a larger, second value. This allows for increased air exchange and effective extraction of excess powder.

[0038] According to the invention, a vertically extending flap is associated with the vertically extending extraction channel, which spatially separates the extraction channel from the coating area of ​​the coating booth, at least in some areas. Preferably, the two vertically extending slot openings are each formed by a vertical gap opening between the flap and a wall of the extraction channel.

[0039] In this context, it is advantageous for the flap to have a cross-sectional geometry that corresponds at least essentially to the cross-sectional geometry of an isosceles triangle, with the area of ​​the flap corresponding to the base of the isosceles triangle facing the coating area of ​​the coating booth.

[0040] With this design, the vertically oriented slot openings create a nozzle function, making it particularly effective to extract excess coating material from inside the cabin.

[0041] According to the invention, it is further provided that the flap extending in a vertical direction is pivotably mounted about an axis running in a vertical direction relative to the extraction channel.

[0042] Preferably, the flap extending in a vertical direction is pivotable between a first position, in which a first effective flow cross-section of the fluid connection provided by the two vertically extending slot openings is set, adapted to a coating operation of the coating booth, and at least a second position, in which a first effective flow cross-section of the fluid connection provided by the two vertically extending slot openings is set, adapted to a cleaning operation of the coating booth.

[0043] In a particularly easy-to-implement yet effective manner, the flap is assigned a drive, in particular an electric motor or pneumatic drive, which is designed to change or adjust the position of the flap relative to the extraction duct as required.

[0044] According to a further aspect of the present invention, this relates to a coating booth of the aforementioned type according to the invention or according to the preamble of claim 1, wherein in this further aspect of the invention it is particularly provided that the vertically extending extraction channel is in fluid contact with the extraction channel via a first horizontal slot opening provided at the upper end region of the extraction channel and via a second horizontal slot opening provided at the lower end region of the extraction channel.

[0045] In particular, it is provided that the extraction duct is connected to an extraction device via its upper end region or its lower end region.

[0046] In this context, it is advantageous for the effective flow cross-section of the horizontal slot opening provided at the end region of the extraction duct, through which the extraction duct is fluidly connected to the extraction device, to be smaller than the effective flow cross-section of the other horizontal slot opening.

[0047] The horizontal slot openings form horizontally oriented extraction slots, i.e., extraction slots that extend horizontally, i.e., in the plane of the cabin floor.

[0048] In order to design the coating booth in particular for robot operation, according to one embodiment of the invention, the coating booth has a coating chamber which defines a coating area of ​​the coating booth at least partially, with a booth floor and with at least one vertically extending side wall, wherein the vertically extending extraction channel of the booth extraction is formed in a corner area of ​​the coating booth.

[0049] In this context, it is particularly conceivable that in a top view of the cabin floor, the cabin floor forms a polygonal surface, in particular with an at least substantially rectangular area which essentially forms the coating area of ​​the coating cabin, and with an area adjoining one side of the rectangular area and converging towards a corner area, wherein the vertically extending extraction channel of the cabin extraction system is formed in the corner area towards which the area adjoining the at least substantially rectangular area converges.

[0050] By providing such a converging area, in whose corner the vertically running extraction duct of the cabin extraction system is located, homogeneous air extraction is ensured in the actual coating area, which is essentially formed by the rectangular part of the cabin. Furthermore, this design of the coating cabin guarantees optimal freedom of movement for the robotic coating process.

[0051] According to further developments of the latter embodiment, it is provided that the at least substantially rectangular area of ​​the cabin floor is designed in a corner area of ​​the substantially rectangular area without at least completely closed vertically extending side walls, wherein outside the at least substantially rectangular area of ​​the cabin floor and in the corner area without the at least completely closed vertically extending side walls a coating robot space for at least one coating robot is provided.

[0052] In this context, it is advantageous for the cabin floor to have a funnel-shaped area (viewed from above) that slopes towards the corner, as well as adjoining side walls that are also inclined in the same direction. This ensures that excess coating material falling onto the cabin floor is moved by gravity towards the cabin's extraction system.

[0053] In particular, in the coating booth according to the invention, it is advantageous that the booth extraction system further comprises at least one horizontally oriented extraction slot arranged on the booth floor, which is preferably connected to the vertically running extraction channel via an extraction duct associated with the at least one horizontally oriented extraction slot arranged on the booth floor.

[0054] The coating booth according to the invention is preferably associated with a conveying device for transporting the workpieces to be coated through the coating chamber defined by the coating booth. A conveying path defined by the conveying device can, in particular, run parallel to one side of the rectangular area and perpendicular to the area converging towards the corner area.

[0055] The floor of the coating booth has, in particular, a trough-, basin- or bowl-shaped interior area with at least one inclined or curved surface in the direction of an extraction opening or in the direction of an extraction duct.

[0056] In this context, it is conceivable that the cabin floor also has a frame-shaped outer area, from which at least one tub-, trough- or basin-shaped inner area is at least partially incorporated.

[0057] According to one aspect of the invention, the cabin floor has an integrated extraction system for the purpose of extracting and / or removing excess coating material, which settles on the cabin floor, particularly as required during the coating operation of the coating cabin.

[0058] The term "excess coating material" used herein refers to so-called "overspray material," i.e., coating material that could not be applied to the workpiece to be coated, or that has already been sprayed at least once during a coating process and has therefore been recycled. Such overspray powder is sometimes also referred to as "recovery" material.

[0059] A particularly homogeneous extraction airflow can be generated within the coating booth via the vertically running extraction channel, which is in fluid contact with the coating area of ​​the coating booth via the two vertically running slot openings, as a result of which excess coating material can be reliably removed over the entire height of the coating booth.

[0060] By positioning the vertically oriented extraction duct in the corner of the converging section of the coating booth, an extraction airflow of uniform strength can be generated throughout the entire booth. Furthermore, the specific design of the two vertically oriented slot openings in the extraction duct results in a favorable, broad velocity profile for the extraction airflow, thus maximizing its intake area.

[0061] According to a further implementation, the coating booth according to the invention can also have at least one manual coating area, which is arranged in front of and / or behind the coating booth next to a workpiece passage.

[0062] By equipping the coating booth according to the invention with at least one and preferably two manual coating areas, the at least one vertically extending extraction duct with the two vertically extending slot openings can also be used to extract the coating material residues from the manual coating area. Consequently, the coating booth according to the invention does not require a separate extraction device specifically for the manual coating area. Rather, the extraction airflow already generated by the vertically extending extraction duct can be used to cover the entire manual coating area.

[0063] The vertically extending extraction duct and the two vertically extending slot openings preferably extend from the floor of the booth to a ceiling area of ​​the coating chamber. In particular, the vertically extending slot openings are designed to be continuous, so that a particularly homogeneous extraction airflow is generated throughout the entire area of ​​the coating booth.

[0064] The design of the two vertically oriented slot openings, which have a smaller effective cross-section in the end section of the vertically oriented extraction duct connected to the extraction device than in the opposite section, advantageously creates a particularly homogeneous airflow. This is because a higher suction airflow exists in the section of the vertically oriented extraction duct connected to the extraction device compared to the opposite end section. However, this difference is compensated for by the different opening cross-sections of the vertically oriented slot openings.

[0065] According to embodiments of the coating booth according to the invention, only the area of ​​the booth floor adjoining one side of the rectangular area of ​​the booth floor and converging towards a corner area is provided with corresponding side walls. Since, on the other hand, the vertically extending extraction channel with the two vertically extending slot openings is provided in the corner area, effective cleaning of the entire side walls of the coating booth is achieved via the extraction system.

[0066] In one embodiment, the vertically extending extraction duct can have a substantially rectangular cross-section. In this embodiment, one side wall of the vertically extending extraction duct is formed by the flap. Furthermore, service flaps can be provided.

[0067] It is also conceivable that the flap can be pivoted relative to the extraction duct in such a way that the at least one vertically running extraction duct can be easily cleaned, for example, during color changes. Accordingly, it is only necessary to move the flap to the at least one second position and clean the interior of the vertically running extraction duct with compressed air or cleaning fluid.

[0068] It is further preferably provided that the coating booth has an extraction area located below the booth floor, which is connected to at least one extraction device. The extraction device is designed to remove the excess coating material extracted by the vertically and horizontally oriented extraction slots.

[0069] In other words, the excess powder extracted through the vertical and horizontal extraction slots can be discharged simultaneously via the common extraction area. Therefore, preferably only one extraction device is required to generate the corresponding extraction airflows.

[0070] According to one embodiment of the coating booth according to the invention, it can have at least one air blowing device which is arranged along the booth floor and is designed to blow excess coating material towards a horizontally extending extraction slot. The at least one air blowing device is preferably arranged opposite the vertically extending extraction duct.

[0071] The at least one vertically extending extraction duct is preferably designed to generate an airflow of 3,000 to 10,000 m³ / h through the corresponding vertically oriented slot openings. In contrast, the optionally provided horizontally extending extraction slots on the cabin floor can preferably each be designed to generate an airflow of 5,000 to 13,000 m³ / h.

[0072] It is conceivable to design the coating booth with two or three horizontally running extraction slots, which extend along the booth floor between the workpiece passages in the transport direction of the workpieces to be coated.

[0073] The present invention is not limited to coating booths used in purely robotic operation. A mixed operation is also conceivable. Operation with multiple coating robots is also conceivable, for example, arranged one above the other in two spaced-apart horizontal planes.

[0074] In particular, the coating booth according to the invention is suitable for a coating operation in which at least one coating robot is used, wherein the robot arm of the at least one coating robot, with a spray device arranged on the robot arm, can be inserted into the interior of the coating booth via the corner area of ​​the coating booth, which is designed without at least completely closed vertically extending side walls, or positioned there, or aligned with respect to the object to be coated. In addition to such a coating robot, a manual coating station can be provided in the rectangular area of ​​the booth. Both the manual coating station and the coating robot can be located outside the actual booth.

[0075] For example, it is conceivable that the coating booth according to the invention could be used by a manual coater on a lifting platform located outside the booth, in order to be able to reach the surfaces to be coated when working with tall parts. Several manual coater stations placed one above the other are also conceivable.

[0076] In particular, a combination of at least one coating robot and one manual coating station is conceivable.

[0077] Furthermore, for example, the lower part of the workpiece can be coated using a first coating robot, while another coating robot, positioned above the first coating robot, is responsible for the upper part of the workpiece.

[0078] Exemplary embodiments of the invention are described in more detail below with reference to the accompanying drawings.

[0079] They show: FIG. 1 schematically and in an isometric view an exemplary embodiment of a coating system for coating workpieces with coating material (here: coating powder), wherein in the illustrated embodiment of the coating system two coating booths arranged one behind the other are used, each according to an exemplary embodiment of the invention; FIG. 2 schematically and in an isometric view the coating booths of the coating system according to FIG. 1 ; FIG. 3 schematically and in a top view the coating booths according to FIG. 2 ; FIG. 4 schematically and in a side view the coating booths according to FIG. 2 ; FIG. 5 schematically and in an isometric view a further development of the exemplary embodiment of one of the two coating booths according to FIG. 2 FIG. 6 schematically and in a top view the embodiment of the coating booth according to FIG. 5 ; FIG. 7 schematic and in a top view an exemplary embodiment of a flap of a vertical extraction duct of the coating booth according to FIG. 2 ; FIG. 7b schematically and in a side view the flap according to FIG. 7a in a side view; FIG. 7c schematically and in a rear view the flap according to FIG. 7a ; FIG. 7 schematic and in a top view of the flap according to FIG. 7a FIG. 8 shows a schematic and top-view view of another exemplary embodiment of the coating booth according to the invention; and FIG. 9 shows a schematic and isometric view of another exemplary embodiment of a coating system for coating workpieces with coating material (here: coating powder), wherein in the illustrated embodiment of the coating system two coating booths arranged one behind the other are used, each according to an exemplary embodiment of the invention.

[0080] FIG. 1 Figure 1 shows a schematic and isometric view of an exemplary embodiment of a coating system 100 for powder coating workpieces.

[0081] The coating system 100 comprises two coating booths 1 arranged one behind the other according to an embodiment of the present invention, wherein the two coating booths 1 are arranged rotated 180° relative to each other. Details of the coating booths 1 are subsequently described with reference to the illustrations in FIG. 2 bis FIG. 6 described in more detail.

[0082] At coating plant 100 according to FIG. 1 The two coating booths 1 are arranged such that they have two diametrically opposed object passages for transporting workpieces to be coated through the powder coating booths 1. The width of the object passages limits the maximum width of the object transport path, i.e., the maximum width of the workpieces that can be coated in the coating booths 1.

[0083] Outside each coating booth 1, coating robots 14 are arranged laterally at each corner of the coating booth 1, each carrying at least one spray device 18, which can be inserted and positioned into the interior of the respective coating booth 1 via a robot arm in order to coat an object with powder inside the corresponding coating booth 1.

[0084] The object to be coated is transported by a transport device 17, for example an endless conveyor chain, transversely to the longitudinal direction of the coating robots 14 through the coating booths 1.

[0085] The spray devices 18 preferably have one or more high-voltage electrodes for electrostatically charging the coating powder and a high-voltage generator for generating the high voltage for the high-voltage electrodes.

[0086] Each coating booth 1 has an extraction duct arrangement through which excess powder can be extracted from the interior of the booth. For this purpose, the excess powder falling during the spraying of coating powder is extracted through at least one vertically extending extraction duct 2 and preferably through at least one longitudinal gap in the floor. The extraction duct 2 is connected via a fluid line system to at least one powder separator 3 for powder recovery.

[0087] At the in FIG. 1 In the illustrated exemplary embodiment of the coating system 100, two powder separators 3 connected in series are used as a powder recovery device to recover the excess powder extracted from the interior of the booths. Firstly, a powder separator 3.1, designed here as a cyclone unit, is provided to separate powder from the powder-air suction stream extracted from the interior of the booths. A second powder separator 3.2, designed as a filter unit, is connected downstream of the cyclone separator 3.1.

[0088] The cyclone separator 3.1 has a cyclone flow inlet and a cyclone air outlet, as well as a cyclone device on the flow path in between for separating powder from the powder-air suction stream by centrifugal forces.

[0089] The cyclone flow inlet is located at the upstream end of a cyclone line (pipe or hose). The cyclone air outlet is connected to the powder separator 3.2, which serves as a post-filter and is designed as a filter unit. This separator filters out the remaining powder that cannot be separated by the cyclone separator 3.1.

[0090] The powder separated from the powder-air stream by the cyclone separator 3.1 falls through a cyclone powder outlet at the lower end of the cyclone into a collection container. The powder in the collection container can be treated as waste or processed and returned to the spray devices 18 in the same way as the powder in the powder container of the downstream filter unit 3.2.

[0091] The in FIG. 1 The schematically shown exemplary embodiment of the powder coating system 100 is characterized in particular by the fact that it is optimized for coating robot applications. For this purpose, two coating booths 1, arranged one behind the other and specially designed for coating robot applications, are used.

[0092] At the in FIG. 1 In the exemplary embodiment shown, the coating booths 1 have a height of, in particular, over 4 m in order to be able to coat even large workpieces accordingly. The coating itself is preferably carried out with the aid of the coating robots 14 provided outside the booths 1, whose robot arms can be moved into the interior of the coating booth 1 via corner areas of the coating booth 1, which are designed without side walls.

[0093] The fact that the side walls of coating booth 1 adjacent to the robot workstation are left open allows for particularly good maneuverability of the robot arms.

[0094] On the other hand, the relatively open design of the coating booths 1 requires optimal extraction of the coating material. According to the invention, this is achieved in particular by an optimized system which has at least one vertically extending extraction channel 2 which is or can be connected in terms of flow to a coating material separator system 3, in particular the cyclone separator 3.1 and the downstream filter separator 3.2.

[0095] As can be seen in the detailed views in particular. FIG. 2 and FIG. 4 The vertically extending extraction channel 2 of the coating material extraction system is in fluid contact with the actual coating area, i.e., with the interior of the coating booth 1, via two vertically extending slot openings 4.

[0096] It is provided that the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings 4 varies continuously in the vertical direction of the extraction channel 2.

[0097] Specifically, the extraction channel 2 has a first end region and an opposing second end region, wherein the extraction channel 2 is fluidically connected to an extraction device via one of the two end regions. In the embodiments shown in the drawings, the lower end region of the extraction channel 2 is connected to the extraction device.

[0098] In particular, it is provided that the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings 4 decreases in the direction of one of the two end regions of the extraction channel 2, via which the extraction channel 2 is fluidly connected to the extraction device, i.e. in the direction of the lower end region of the extraction channel 2 in the embodiments shown in the drawings.

[0099] As the detailed view shows in FIG. 4 The two vertically extending slot openings 4 each have the shape of a triangle, in particular a right-angled triangle.

[0100] According to one aspect, the coating booth 1 according to the invention, which is shown schematically in the drawings according to exemplary embodiment variants, is characterized in that an effective flow cross-section of the fluid connection provided by the two vertically extending slot openings 4 is variably adjustable.

[0101] Specifically, the flow cross-section can be adjusted to a first value, which is adapted to a coating operation of coating booth 1, and at least one further second value, which is larger compared to the first value and which is adapted to a cleaning operation of coating booth 1.

[0102] In detail, in the exemplary embodiments of the coating booth 1 according to the invention shown in the drawings, a flap 6 extending in a vertical direction is assigned to the vertically extending extraction channel 2, which spatially separates the extraction channel 2 from the coating area of ​​the coating booth 1 at least in some areas, wherein the two vertically extending slot openings 4 are each formed by a vertical gap opening between the flap 6 and a wall 7 of the extraction channel 2.

[0103] One embodiment of flap 6 is described in detail in FIG. 7a bis FIG. 7d shown.

[0104] In particular, the flap 6 has a cross-sectional geometry that corresponds at least essentially to the cross-sectional geometry of an isosceles triangle, wherein the area of ​​the flap 6 corresponding to the base of the isosceles triangle faces the coating area of ​​the coating booth 1, i.e. the interior of the coating booth 1.

[0105] The flap 6, extending in a vertical direction, is pivotably mounted about an axis 8 extending in a vertical direction relative to the extraction channel 2, in particular between a first position in which a first effective flow cross-section of the fluid connection provided by the two vertically extending slot openings 4, adapted to a coating operation of the coating booth 1, is set, and at least a second position in which a second effective flow cross-section of the fluid connection provided by the two vertically extending slot openings 4, adapted to a cleaning operation of the coating booth 1, is set.

[0106] To adjust the flap 6, a drive, in particular an electromechanical, pneumatic or hydraulic drive, can be assigned to it, which is designed to change or adjust the position of the flap 6 relative to the extraction channel 2 as required.

[0107] In the embodiments of the coating booth 1 according to the invention, it is further provided that the vertically extending extraction channel 2 is in fluid contact with the extraction channel 2 via a first horizontal slot opening 10 provided at the upper end region of the extraction channel 2 and a second horizontal slot opening 10 provided at the lower end region of the extraction channel 2.

[0108] In particular, it is provided that the extraction channel 2 is fluidically connected to the aforementioned extraction device via its lower end region, wherein the effective flow cross-section of the horizontal slot opening 10, which is provided at the lower end region of the extraction channel 2, is smaller than an effective flow cross-section of the other (upper) horizontal slot opening 10.

[0109] In the embodiments of the coating booth 1 according to the invention shown in the drawings, it is further provided that the coating booth 1 has a coating chamber which defines a coating area of ​​the coating booth 1 at least partially, with a booth floor 11 and with at least one vertically extending side wall, wherein the vertically extending extraction channel 2 of the booth extraction is formed in a corner area of ​​the coating booth 1.

[0110] In particular, for example, the representation in FIG. 3 It can be seen that, viewed from a top view of the cabin floor 11, the cabin floor 11 forms a polygonal surface, in particular with an at least substantially rectangular area 12 and with an area 13 adjoining one side of the rectangular area 12 and converging towards a corner area, wherein the vertically extending extraction channel 2 of the cabin extraction system is formed in the corner area in the direction towards which the area adjoining the at least substantially rectangular area 12 converges.

[0111] The substantially rectangular area 12 of the cabin floor 11 is formed without vertically extending side walls in one corner area. Outside the substantially rectangular area 12 of the cabin floor 11 and at the corner area without vertically extending side walls, a coating robot space for at least one coating robot 14 is provided.

[0112] In particular, in the embodiments of the coating booth 1 according to the invention shown in the drawings, it is provided that the booth floor 11 has a funnel-shaped floor area inclined towards the corner area in a top view of the booth floor 11, as well as side areas adjoining the funnel-shaped floor area inclined towards the corner area, which are each inclined towards the funnel-shaped floor area inclined towards the corner area.

[0113] The cabin extraction system preferably also has at least one horizontally oriented extraction slot arranged on the cabin floor 11, which is preferably connected in terms of flow to the vertically running extraction channel 2 via an extraction channel 2 associated with the at least one horizontally oriented extraction slot arranged on the cabin floor 11.

[0114] For example, in FIG. 1 bis FIG. 4 As shown, it is possible to arrange two or more coating booths 1 one behind the other in a corresponding coating system 100, whereby these may be rotated by 180° relative to each other.

[0115] It is also conceivable in principle that a manual coating station or automatic coating area 16 is assigned to the coating booth 1, as in the embodiment according to FIG. 5 and FIG. 6 that is the case.

[0116] FIG. 8 schematically and in a top view shows another exemplary embodiment of the coating booth 1 according to the invention.

[0117] As in FIG. 8 As indicated schematically, the coating booth 1 shown there is equipped with a vertically extending extraction duct 2, which is in fluid contact with a coating area of ​​the coating booth 1 via two vertically extending slot openings 4. The extraction duct is fluidically connected via one of its end sections to a FIG. 8 connected to the extraction device not shown.

[0118] As with the previously described embodiments of the coating booth 1 according to the invention, the FIG. 8 A coating booth 1, shown schematically in a top view, is provided with a flap 6 extending in a vertical direction, which at least partially separates the extraction duct 2 from the coating area 5 of the coating booth 1.

[0119] The in FIG. 8 The coating booth shown schematically in a top view differs from the previously described coating booths, particularly in its integrated floor extraction system. Specifically, coating booth 1 is described below. FIG. 8 Eleven horizontally oriented extraction slots are provided on the cabin floor to extract excess coating material that falls onto the cabin floor during a coating process.

[0120] FIG. 9 Figure 1 shows schematically and in an isometric view another exemplary embodiment of a coating system 100 for powder coating workpieces.

[0121] As well as the ones in FIG. 1 The illustrated embodiment features the coating system 100 according to FIG. 9 Two coating booths 1 arranged one behind the other according to an embodiment of the present invention, wherein the two coating booths 1 are arranged rotated 180° relative to each other. Details of the coating booths 1 were previously described with reference to the illustrations in FIG. 2 bis FIG. 6 described in more detail.

[0122] At coating plant 100 according to FIG. 9 The two coating booths 1 are arranged such that they have two diametrically opposed object passages for transporting workpieces to be coated through the powder coating booths 1. The width of the object passages limits the maximum width of the object transport path, i.e., the maximum width of the workpieces that can be coated in the coating booths 1.

[0123] Outside each coating booth 1, coating robots 14 are arranged laterally at each corner of the coating booth 1, each carrying at least one spray device 18, which can be inserted and positioned into the interior of the respective coating booth 1 via a robot arm in order to coat an object with powder inside the corresponding coating booth 1.

[0124] The object to be coated is transported by a transport device 17, for example an endless conveyor chain, transversely to the longitudinal direction of the coating robots 14 through the coating booths 1.

[0125] The in FIG. 9 The schematically shown exemplary embodiment of the powder coating system 100 is characterized in particular by the fact that it is optimized for both coating robot applications and manual coating applications. For this purpose, two specially designed coating booths 1 arranged one behind the other are used.

[0126] At the in FIG. 9 In the exemplary embodiment shown, the coating booths 1 have a height of, in particular, over 4 m in order to be able to coat even large workpieces accordingly. The coating itself is preferably carried out with the aid of the coating robots 14 provided outside the booths 1, whose robot arms can be moved into the interior of the coating booth 1 via corner areas of the coating booth 1, which are designed without side walls.

[0127] The fact that the side walls of coating booth 1 adjacent to the robot workstation are left open allows for particularly good maneuverability of the robot arms.

[0128] On the other hand, the relatively open design of the coating booths 1 requires optimal extraction of the coating material. According to the invention, this is achieved in particular by an optimized system which has at least one vertically extending extraction channel 2 which is or can be connected in terms of flow to a coating material separator system 3, in particular the cyclone separator 3.1 and the downstream filter separator 3.2.

[0129] At the in FIG. 9 In the embodiments shown, it is provided that the coating booth 1 has a coating chamber which defines a coating area of ​​the coating booth 1 at least partially, with a booth floor 11 and with at least one vertically extending side wall, wherein the vertically extending extraction channel 2 of the booth extraction is formed in a corner area of ​​the coating booth 1.

[0130] Viewed from a top view of the cabin floor 11, the cabin floor 11 forms a polygonal surface, in particular with an at least substantially rectangular area and with an area adjoining one side of the rectangular area and converging towards a corner area, wherein the vertically extending extraction channel 2 of the cabin extraction system is formed in the corner area in the direction towards which the area adjoining the at least substantially rectangular area converges.

[0131] The at least substantially rectangular area of ​​the cabin floor 11 is formed in a corner area of ​​the substantially rectangular area 12 without completely closed vertically extending side walls. In contrast to the embodiment according to FIG. 1 are in the embodiment according to FIG. 9 Although the corner area has vertically running side walls, these have relatively large window areas (19).

[0132] Outside the at least substantially rectangular area 12 of the cabin floor 11 and at the corner area, a coating robot space for at least one coating robot 14 is provided.

[0133] The invention is defined by the claims. Bezugszeichenliste

[0134] 1 Coating booth 2 Vertically oriented extraction duct of the booth extraction system 3 Coating material separator system 3.1 Cyclone separator 3.2 Filter unit 4 Vertically oriented slot openings of the vertically oriented extraction duct 6 Flap 7 Wall of the extraction duct 8 Vertically oriented axis of the flap 10 Horizontally oriented slot opening of the vertically oriented extraction duct 11 Booth floor 12 Rectangular area of ​​the booth floor 13 Converging area of ​​the booth floor 14 Coating robot 16 Manual coating station or automatic coating area 17 Conveyor device 18 Spray device 19 Window area 100 Coating system

Claims

1. A coating booth (1) for coating workpieces with coating material, in particular with coating powder, wherein a booth suction system is assigned to the coating booth (1) a for extracting, in particular as required, excess coating material produced during a coating process, wherein the coating material suction system comprises at least one vertically extending suction channel (2) which is fluidically connected to a coating material separator system (3; 3.1, 3.2), characterized in that the vertically extending suction channel (2) is in fluid communication with a coating area of the coating booth (1) via two vertically extending slot openings (4), wherein an effective flow cross-section of the fluid connection provided by the two vertically extending slot openings (4) varies continuously in the vertical direction of the suction channel (2), wherein a flap (6) extending in the vertical direction is assigned to the vertically extending suction channel (2), the flap spatially separating the suction channel (2) at least partly from the coating area of the coating booth (1), wherein the two vertically extending slot openings (4) are each formed by a vertical gap opening between the flap (6) and a wall (7) of the suction channel (2), wherein the flap extending in the vertical direction (6) is mounted so that it can pivot about a vertically extending axis (8) relative to the suction channel (2), preferably between a first position in which a first effective flow cross-section of the fluid connection provided by the two vertically extending slot openings (4) is set, adapted to a coating operation of the coating booth, and at least a second position in which a second effective flow cross-section of the fluid connection provided by the two vertically extending slot openings (4) is set, adapted to a cleaning operation of the coating booth (1).

2. The coating booth (1) according to claim 1, wherein the suction channel (2) has a first end region and an opposite second end region, wherein the suction channel (2) is fluidically connected via one of the two end regions to a suction device, wherein the effective flow cross-section of the fluid connection provided by the two vertically extending slot openings (4) decreases particularly continuously in the direction of one of the two end regions of the suction channel (2) via which the suction channel (2) is fluidically connected to the suction device.

3. The coating booth (1) according to claim 1 or 2, wherein the two vertically extending slot openings (4) each have the shape of a triangle, in particular a right-angled triangle.

4. The coating booth (1) according to any one of claims 1 to 3, wherein the vertically extending suction channel (2) is in fluid communication with a coating area of the coating chamber via two vertically extending slot openings (4), wherein an effective flow cross-section of the fluid connection provided by the two vertically extending slot openings (4) is variably adjustable, preferably to a first value which is adapted to a coating operation of the coating booth (1) and a second value which is greater than the first value and is adapted to a cleaning operation of the coating booth (1).

5. The coating booth (1) according to any one of claims 1 to 4, wherein the flap (6) has a cross-sectional geometry that corresponds at least substantially to the cross-sectional geometry of an isosceles triangle, wherein the surface of the flap (6) corresponding to the base of the isosceles triangle faces the coating area of the coating booth (1).

6. The coating booth (1) according to any one of claims 1 to 5, wherein the flap (6) is assigned an electric motor or pneumatic drive in particular, which is designed to change or adjust the position of the flap (6) relative to the suction channel (2) as required.

7. The coating booth (1) according to any one of claims 1 to 6, wherein the vertically extending suction channel (2) is in fluid communication with the suction channel (2) via a first horizontal slot opening (4) provided at the upper end region of the suction channel (2) and via a second horizontal slot opening (4) provided at the lower end region of the suction channel (2), whereby the suction channel (2) is fluidically connected via its upper end region or via its lower end region to a suction device, and whereby an effective flow cross-section of the horizontal slot opening (4) provided at the end region of the suction channel (2), via which the suction channel (2) is fluidically connected to the suction device, is smaller than an effective flow cross-section of the other horizontal slot opening (4).

8. The coating booth (1) according to any one of claims 1 to 7, wherein the coating booth (1) has a coating chamber with a booth floor (11) and at least one vertically extending side wall, which defines at least part of a coating area of the coating booth (1), wherein the vertically extending suction channel (2) of the booth suction system is formed in a corner area of the coating booth (1).

9. The coating booth (1) according to claim 8, wherein, in a top view of the booth floor (11), the booth floor (11) forms a polygonal surface, in particular with an at least substantially rectangular area (12) and with an area (13) adjoining one side of the rectangular area (12) and converging towards a corner area, wherein the vertically extending suction channel (2) of the booth suction system is formed in the corner area towards which the area adjoining the at least substantially rectangular area (12) converges.

10. The coating booth (1) according to claim 9, wherein the at least substantially rectangular area (12) of the booth floor (11) is formed in a corner area of the substantially rectangular area (12) without at least completely closed vertically extending side walls, and wherein a coating robot space for at least one coating robot (14) is provided outside the at least substantially rectangular area (12) of the booth floor (11) and at the corner area without the at least completely closed vertically extending side walls.

11. The coating booth (1) according to claim 9 or 10, wherein the booth floor (11) has a floor area that is funnel-shaped in a top view of the booth floor (11) and inclined toward the corner area, as well as side areas adjoining the funnel-shaped floor area inclined toward the corner area, each of which is inclined toward the funnel-shaped floor area inclined toward the corner area.

12. The coating booth (1) according to any one of claims 9 to 11, wherein the booth suction system has at least one horizontally aligned suction slot arranged on the booth floor (11), which is preferably fluidically connected via a suction channel (2) assigned to the at least one horizontally aligned suction slot arranged on the booth floor (11) to the vertically extending suction channel (2).

13. The coating booth (1) according to any one of claims 9 to 12, wherein the coating booth (1) is assigned a conveyor device (17) for transporting the workpieces to be coated through the coating chamber (1) defined by the coating booth (1), wherein a conveyor path specified by the conveyor device (17) runs parallel to one side of the rectangular area (12) and perpendicular to the area (13) converging in the direction of the corner area.