Base body for a coating cell of a coating system

Abstract

The invention relates to a main part (5) for a coating cell (2) of a coating plant (1), the main part (5) having a modular design and being preferably an exchangeable element within the entire system of the coating plant (1). The main part (5) is further designed to be connectible to at least one sidewall (12) which is preferably in the form of a module, to provide a particularly user-specifically configured coating cell (2).

Description

[0001] The present invention relates generally to the surface treatment of workpieces and in particular to the coating of workpieces with coating material, in particular coating powder.

[0002] According to one aspect of the present invention, it relates to a coating booth or coating cell of a coating system optimized for coating workpieces.

[0003] Coating booths or coating cells for coating workpieces, particularly with coating powder, are generally known in the art. Such coating booths or coating cells typically comprise a coating chamber with a booth floor, two opposing workpiece passages, and a conveyor device for transporting the workpieces to be coated through the coating chamber.

[0004] For example, EP 0 071 756 A2 relates to a coating booth with a conveyor device that transports the objects to be coated through an entrance and an exit through the booth interior. A spraying device in the booth is a wall element that can be opened through doors and contains a hand-held spray gun. However, automatically controlled spray guns can also be provided. The doors also allow access to the booth interior. The spraying devices with the spray guns can all be arranged on the same side of the booth. Spraying devices in the form of prepared wall elements with slots for the passage of guns can also be provided on the opposite side.

[0005] Instead of a conveyor device for automatically transporting the objects to be coated through the cabin interior, the objects to be coated can also be manually inserted into the cabin interior and - after a coating process - removed again.

[0006] The conveyor device for automatically transporting the objects to be coated through the cabin interior can also be arranged below the cabin floor of the coating cabin and have a workpiece carrier which projects through a conveyor slot in the cabin floor into the coating chamber of the coating cabin.

[0007] Coating booths with such "floor conveyors" are particularly used for coating high-quality workpieces, as the arrangement of the conveyor below the booth floor allows for high coating quality. This is primarily due to the fact that "traditional" conveyors for suspended transport of workpieces through the coating chamber can encourage dirt particles or powder residues to fall off the conveyor, which can lead to irregularities in the coating.

[0008] On the other hand, especially for powder coating, booths or systems for discontinuous workpiece transport during manual coating are also known. This type of booth differs from flow-through 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 job to be performed by the coater, whereby a distinction can essentially be made between the following categories: large production batches in just one or a few colours (e.g. coating area 1,000 m² and more); medium production batches in several colours (e.g. coating area 200 to 1,000 m²); application of many different colours for small batch sizes (e.g. coating area in the order of 100 m²); individual production, coating of very small batches, for example for sample production in a wide variety of colours; and carrying out cleaning work on individual parts / workpieces and equipment.

[0009] This categorization already shows how different the requirements are for each system / cabin used, and that it is important to find the most favorable ratio between working / setup time, material costs and environmental impact.

[0010] It's easy to see that fulfilling the five functional categories mentioned above has quite different key requirements. For large production batches, efforts will be made to work as automated as possible; automatic coating systems are typically used for this purpose. For medium-sized batches, the main focus is on reducing setup and, in particular, cleaning times due to the need for rapid color changes.

[0011] The document DE 89 07 540 U1 relates to a booth for spray coating objects with powdered coating material.

[0012] The document EP 0 384 236 A1 relates to a powder spray booth with a guide device for raw gas into a separator suction flow.

[0013] The document US 2005 / 0011438 A1 relates to a powder spray booth with a powder recovery system.

[0014] The document US 4,417,541 A also relates to a spray booth for wet paint applications.

[0015] The document EP 0 678 336 A2 relates to a powder coating booth with side walls between which a floor is arranged and with a discharge opening in the area of the floor.

[0016] The publication SE 528 772 C2 concerns a spray painting booth in which an operator can coat a workpiece with wet paint from outside.

[0017] The object of the present invention is to provide a booth concept which allows coating booths or coating systems to be used as flexibly and automatically as possible and yet still delivers optimum productivity and cost-effectiveness.

[0018] In particular, the booth concept should be suitable for addressing the special features that arise with the increasing automation of the coating process, namely the increasing use of coating robots for the automated coating process. Furthermore, the booth concept should be able to respond as flexibly as possible to different requirements.

[0019] This object is achieved according to the invention by the subject matter of independent patent claim 1, wherein advantageous further developments thereof are specified in the dependent patent claims.

[0020] Accordingly, the present invention relates in particular to a modular coating concept which allows a coating booth or coating cell to be designed in a particularly simple manner to suit the specific application in order to be able to optimally take into account all the special features of the individual case.

[0021] The coating cell according to the invention comprises a base body, wherein the base body has a modular structure and is preferably designed as an interchangeable element within the overall system of the coating system. The base body is particularly designed to be connectable to at least one side wall, preferably designed as a module, in order to be able to provide a coating cell configured in a particularly application-specific manner.

[0022] According to embodiments, the base body is designed to be connected to another base body, preferably of the same kind or type, to form at least one region of a coating line of a coating system.

[0023] Particularly preferably, the base body forms the lower part and the cell floor of the coating cell and, in particular, has a polygonal and preferably rectangular base area. In particular, the base body has at least one tub-, trough-, or trough-shaped interior region forming the cell floor of the coating cell, with at least one surface inclined or curved in the direction of a suction opening or in the direction of a suction channel.

[0024] In this context, it is conceivable that the base body further comprises a frame-shaped outer region, by which the at least one tub-, trough- or trough-shaped inner region is at least partially accommodated.

[0025] According to one aspect of the invention, the base body has an integrated suction system for suctioning and / or removing overspray powder, in particular as required, during coating operation of the coating cell.

[0026] The term "overspray powder" as used herein refers to 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 been recycled accordingly. Such overspray powder is sometimes also referred to as "recovery" material.

[0027] In this context, according to embodiments of the present invention, the extraction system has at least one extraction opening formed in the frame-shaped outer region and preferably arranged centrally in a side wall of the outer region and fluidly connectable to a vacuum source. This at least one extraction opening is fluidly connected via a duct system formed between the outer region and the inner region to at least one extraction opening opening into the inner region and / or to at least one extraction duct formed at least partially in the inner region. According to further developments thereof, the base body has two tub-, trough-, or trough-shaped inner regions arranged next to one another and formed as a mirror image of one another, which are accommodated in a common frame-shaped outer region.

[0028] It is conceivable that the extraction system has at least one extraction opening formed in the frame-shaped outer region and preferably arranged centrally in a side wall of the outer region and fluidically connectable to a vacuum source, wherein the extraction opening is fluidically connected via a duct system formed between the outer region and the two inner regions to an extraction opening opening into a first inner region of the two inner regions and to an extraction opening opening into a second inner region of the two inner regions.

[0029] Particularly in coating systems having a plurality of coating cells, it is conceivable that the at least one suction opening formed in the frame-shaped outer region can be fluidly connected to a suction system of a further base body of a coating cell and preferably to a suction system of a further base body of the same kind or type.

[0030] The base body preferably has an integrated blow-off system for the release of compressed air, particularly as needed and preferably in a pulsed manner, particularly along the at least one inclined or curved surface of the booth floor and in the direction of the extraction opening or the extraction channel. In this context, it is advantageous for the blow-off system to have at least one blow-off bar and preferably a plurality of blow-off bars, which can optionally be individually controlled and supplied with compressed air. The blow-off bars have corresponding blow-off openings, which preferably open into the interior area at an edge region of the interior area.

[0031] With regard to the coating booth, it is advantageously provided that at least partial areas of the booth floor surrounding the conveyor slot are ramp-shaped, wherein at least one air blowing device is provided for the preferably pulsed discharge of an air stream along the ramp-shaped partial area of the booth floor toward at least one extraction channel provided in the booth floor. Advantageously, the at least one air blowing device is provided at the conveyor slot.

[0032] Preferably, at least one additional air blowing device is used on or in at least one side wall of the coating booth, which is adjacent to the side walls with the workpiece passages. The additional air blowing device is particularly designed to blow out an air stream, preferably in a pulsed manner, along the booth floor in the direction of the at least one extraction channel provided in the booth floor.

[0033] The invention relates to a coating cell of a coating system, wherein the coating cell has a base body of the type described above and at least one side wall configured as a module with the base body, and preferably also a roof area connected or connectable to the at least one side wall. The coating cell according to the invention is particularly suitable for the automated powder coating of workpieces. The coating cell preferably has a base area adapted to the operating radius of a coating robot.

[0034] The coating cell preferably has two passages for feeding and discharging the workpiece and a single side wall opposite the open side of the coating cell where the coating robot is provided.

[0035] The base body of the coating cell is the basic component, which allows for flexible construction of coating cells for different applications. The base body, which serves as the lower part, is modular and standardized.

[0036] The modular design of the base body makes it possible to customize the coating cell and, in particular, to connect at least one side wall to the base body in such a way that a coating robot has optimal access, for example, from a first, second, or third side or from a corner of the base body. This flexible coating cell is primarily used in conjunction with coating robots, but could also be integrated into a series system with a conventional automatic system (axis and manual coating stations).

[0037] The base area of the main body is preferably 1 to 3 m (width and length) and typically 1.5 to 2.5 m. In a double cell, the length is increased, but the width remains in the same order of magnitude.

[0038] The invention is described in more detail below with reference to the accompanying drawings.

[0039] They show: FIG. 1 schematically and in an isometric view a portion of a coating system with coating cells according to embodiments of the present invention; FIG. 2 schematically and in an isometric view a first exemplary embodiment of the inventive base body of a coating cell; FIG. 3 schematically and in an isometric view a second exemplary embodiment of the inventive base body of a coating cell; FIG. 4 schematically and in an isometric view a third exemplary embodiment of the inventive base body of a coating cell; and FIG. 5 schematically and in an isometric view a fourth exemplary embodiment of the inventive base body of a coating cell.

[0040] FIG. 1 shows schematically an exemplary embodiment of a powder coating system 1 according to the inventive solution. The powder coating system 1 is used for spray coating objects with coating powder, which is then FIG. 1 The powder is melted onto the objects in a heating furnace (not shown). One or more electronic control units are provided to control the function of the powder coating system 1.

[0041] Powder pumps are provided for pneumatically conveying the coating powder. These can be injectors, in which compressed air serving as conveying air is drawn from a powder container to convey the coating powder. The mixture of conveying air and coating powder then flows together into a container or to a spray device. Suitable injectors are known, for example, from document EP 0 412 289 B1.

[0042] Pump types that convey small powder portions one after the other using compressed air can also be used as powder pumps. A small portion of powder (amount of powder) is stored in a powder chamber and then expelled from the powder chamber using compressed air. The compressed air remains behind the powder portion and pushes the powder portion forward. These pump types are sometimes referred to as "compressed air push pumps" or "plug-feed pumps" because the compressed air pushes the stored powder portion forward through a pump outlet line like a plug. Various types of such powder pumps for conveying dense coating powder are known, for example, from the following publications: DE 103 53 968 A1, US 6,508,610 B2, US 2006 / 0193704 A1, DE 101 45 448 A1, or WO 2005 / 051549 A1.

[0043] The invention is not limited to one of the types of powder pumps mentioned.

[0044] In the coating system according to FIG. 1 For each coating cell 2, an applicator system 3 is used for spraying coating material as required in the corresponding coating cell 2. The applicator system 3 has at least one corresponding gun system 4 for spraying coating material as required.

[0045] In the coating system 1 according to the invention, it is provided in particular that a robot system is assigned to the at least one gun system 4 for positioning and / or aligning the gun system relative to the workpieces to be coated during a coating process.

[0046] The robot system together with the at least one gun system 4 form a coating robot 3, which—in contrast to conventional axis or positioning systems—is not designed as a system that moves with the workpieces to be coated during transport through the coating cell 2. Each coating robot 3 is movable in three dimensions relative to the base body 5 of the coating cell 2 and relative to a workpiece.

[0047] According to preferred implementations of the coating system 1 according to the invention, it is provided in particular that a robot arm system is assigned to the at least one gun system 4, which robot arm system can be moved in all directions below or above a conveyor device for the workpieces to be coated with the aid of a robot guide.

[0048] The gun system 4 preferably comprises at least one coating gun. The coating gun is preferably an electrostatic coating gun, which is designed to electrostatically charge the coating material to be sprayed with the coating gun.

[0049] According to preferred implementations of the coating system 1 according to the invention, a control device is assigned to the coating gun(s) for controlling and / or regulating the current intensities for charging the coating material. The control device should, in particular, be designed to regulate current values below 10 µA in at least 0.5 µA increments.

[0050] As particularly in FIG. 2 bis FIG. 5 As shown, with regard to the coating cell 2, it is advantageously provided that at least partial areas of the booth floor are ramp-shaped, wherein at least one air blowing device is provided for the preferably pulsed blowing out of an air stream along the ramp-shaped partial area of the booth floor in the direction of at least one suction channel 6 provided in the booth floor.

[0051] Preferably, at least one further air blowing device is used on or in at least one side wall of the coating cell 2, which is adjacent to the side walls with the workpiece passages. The one further air blowing device is particularly designed to blow out an air stream, preferably in a pulsed manner, along the booth floor in the direction of the at least one extraction channel 6 provided in the booth floor.

[0052] The coating system 1 has a FIG. 1 coating material supply (not shown) for supplying coating material to the gun systems 4 of the coating robots 3. The coating material supply is designed in particular to supply the corresponding gun systems 4 with only fresh coating material or fresh coating material with recovery material or only recovery material, as required.

[0053] The term "recovery material" as used herein refers to coating material that has already been sprayed at least once during a coating process and has been recycled accordingly. Such recovery material is sometimes also referred to as "overspray" material.

[0054] According to further developments of the coating system according to the invention, it is provided that the coating material supply preferably has at least one coating material pump for each gun system 4, wherein the coating material pump is preferably based on the dense phase principle and is designed for continuous coating material delivery.

[0055] Coating powder that does not adhere to the object to be coated is sucked into a cyclone separator 9 as overspray powder via an excess powder line 7 by means of a suction air stream from a fan 8. The excess powder is separated from the suction air stream in the cyclone separator 9 as much as possible. The separated powder portion is then transported as recovery powder from the cyclone separator 9 via a powder recovery line to an optionally provided screening device, where it passes through the screening device, either alone or mixed with fresh powder via powder feed lines, and returns to the spray guns 4 of the robot systems.

[0056] The exhaust air from the cyclone separator 9 passes through an exhaust air duct 10 into a post-filter device 11 and therein through one or more filter elements to the fan 8, and then into the outside atmosphere. The filter elements can be filter bags, filter cartridges, filter plates, or similar filter elements. The powder separated from the air stream by the filter elements is usually waste powder and falls into a waste container by gravity or can be conveyed via one or more waste lines to a waste container at a waste station.

[0057] FIG. 1 shows in particular a partial area of a coating system 1, which has two coating cells 2, each of which is equipped with an exemplary embodiment of the base body 5 according to the invention.

[0058] The FIG. 1 The coating system 1 shown schematically and in an isometric view comprises in detail a first coating cell 2 and a second coating cell 2 arranged directly adjacent thereto. Each of the two coating cells 2 is characterized in that it is designed for automatic powder coating with the aid of a coating robot 3.

[0059] In contrast to coating cells 2, which were previously used for automatic powder coating, the ones used in FIG. 1 The coating cells 2 used in the schematically illustrated coating system 1 are designed in particular with regard to powder coating with the aid of a coating robot 3. For this purpose, each coating cell 2 has only one (single) side wall 12 with a roof area 13, which preferably only partially covers the top of the coating cell 2 in order to be able to optimally utilize the maneuverability of the coating robot 3.

[0060] The side of the coating cell 2 opposite the single side wall 12 is designed as an "open" side wall, so that the coating robot 3 can FIG. 1 can completely coat a workpiece to be coated (not shown) if required.

[0061] The respective base bodies 5 of the coating cells 2 used in the coating system 1 each have a modular structure and are preferably identical to one another. Each base body 5 can be designed as an interchangeable element within the overall system of the coating system 1. The respective side walls 12, which are connected to the base bodies 5, are preferably also of the same design and can be individually connected as a module to the base bodies 5 of the coating cells 2.

[0062] The two base bodies 5 of the coating cells 2 are connected to each other and each form the lower part and the cell floor of the corresponding coating cell 2. A polygonal and, in particular, rectangular base area of the cell floor is particularly preferred.

[0063] An integrated extraction system is assigned to the base body 5 of the coating cells 2 in order to extract and remove any overspray powder that may arise during the coating operation of the coating cell 2.

[0064] In FIG. 2 bis FIG. 5 Different embodiments of the base body 5 according to the invention are shown, each in an isometric and schematic view. Each embodiment of the base body 5 has a modular structure and is designed to be connectable to at least one side wall 12, preferably also designed as a module, in order to provide a coating cell 2 configured in particular for a specific application.

[0065] As in FIG. 2 bis FIG. 5 As shown, the base bodies 5 form the lower part and the cell bottom of the coating cell 2 and each have a polygonal and in particular rectangular base area.

[0066] Each base body 5 has at least one tub-, trough- or trough-shaped inner region 14 forming the cell floor of the coating cell 2 with at least one surface 16 inclined or curved in the direction of a suction opening 15, 19 or in the direction of a suction channel 6.

[0067] It is provided that the base body 5 has a frame-shaped outer region 17, by which the at least one tub-, trough- or trough-shaped inner region 14 is at least partially received.

[0068] As already mentioned in connection with the FIG. 1 As shown schematically in the exemplary embodiment of the coating system 1, each base body 5 has an integrated extraction system, in particular to extract or remove overspray powder as needed during powder coating operation of the coating cell 2. In particular, it is provided in this context that the extraction system has at least one extraction opening 19 formed in the frame-shaped outer region 17 and preferably arranged centrally in a side wall 18 of the outer region 17 and fluidly connectable to a vacuum source.

[0069] This at least one suction opening 19 is fluidly connected via a channel system formed between the outer region 17 and the inner region 14 to at least one suction opening 19 opening into the inner region 14 and / or to at least one suction channel 6 formed at least partially in the inner region 14.

[0070] As can be seen in particular from the schematic representation in FIG. 5 can be removed, it can be provided according to embodiments of the present invention that the base body 5 has two (or more) tub-, trough- or trough-shaped inner regions 14 arranged next to one another and in particular formed as a mirror image of one another, which are accommodated in a common frame-shaped outer region 17.

[0071] At the FIG. 5 In the schematically illustrated embodiment of the base body 5 according to the invention, the suction system has at least one suction opening 19 formed in the frame-shaped outer region 17 and preferably arranged centrally in a side wall of the outer region 17 and fluidly connectable to a vacuum source, wherein this suction opening 19 is fluidly connected via a channel system formed between the outer region 17 and the two inner regions to a suction opening 19 opening into a first inner region 14 of the two inner regions 14 and to a suction opening 19 opening into a second inner region 14 of the two inner regions 14.

[0072] In principle, it is advantageous if the at least one suction opening 19 formed in the frame-shaped outer region 17 can be fluidly connected to a suction system of another base body 5, preferably of the same type or type. In other words, with regard to the on-demand suction of overspray powder, a series connection of the base bodies 5 is possible.

[0073] The exemplary embodiments of the base body 5 according to the invention preferably further comprise an integrated blow-off system in order to be able to release compressed air, in particular as needed and preferably in a pulsed manner, in particular along the at least one inclined or curved surface 16 and in the direction of the suction opening 19 or the suction channel of the base body 5.

[0074] In this context, it is advisable for the blow-off system to have at least one blow-off bar and preferably a plurality of blow-off bars, wherein the at least one blow-off bar has at least one discharge opening which opens into the inner region 14 in an edge region of the inner region. FIG. 2 It is indicated how the blowing out, preferably the pulsed blowing out of compressed air, can be carried out in the cleaning operation.

Claims

1. A coating cell (2) of a coating system (1), wherein the coating cell (2) comprises a base body (5) and at least one side wall (12) connected to the base body (5) in an exchangeable manner and designed as a module, and preferably also a roof area (13) connected to or connectable to the at least one side wall (12), wherein the base body (5) has a modular structure and is designed as an interchangeable element within the overall coating system (1), wherein the base body (5) is further designed to be connectable to at least one preferably modularly designed side wall (12) so as to provide an application-specific configured coating cell (2), characterized in that the coating cell (2) is designed for powder coating by means of a coating robot (3), wherein for this purpose the coating cell (2) has only a single side wall (12) with a roof area (13) which only partially covers the upper side of the coating cell (2), in order to make optimum use of the manoeuvrability of the coating robot (3), wherein the side of the coating cell (2) opposite the single side wall (12) is designed as an open side wall, so that the coating robot (3) can coat a workpiece to be coated completely if necessary.

2. The coating cell (2) according to claim 1, wherein the base body (5) is designed to be connected to a further base body (5), preferably of the same kind or type, so as to form at least one section of a coating line of a coating system (1).

3. The coating cell (2) according to claim 1 or 2, wherein the base body (5) forms the lower part and the cell floor of the coating cell (2) and forms a polygonal and particularly rectangular surface area.

4. The coating cell (2) according to claim 3, wherein the base body (5) has at least one tub-shaped, trough-shaped or recessed interior area (14) forming the cell floor of the coating cell (2) which has at least one surface (16) inclined or curved in the direction of an extraction opening (15) or in the direction of an extraction duct (6).

5. The coating cell (2) according to claim 4, wherein the base body (5) comprises a frame-shaped exterior area (17) which at least partially accommodates the at least one tub-shaped, trough-shaped or recessed interior area (14).

6. The coating cell (2) according to one of claims 1 to 5, wherein the base body (5) comprises an integrated extraction system for suctioning or drawing off overspray powder during the coating operation of the coating cell (2), particularly as needed.

7. The coating cell (2) according to claim 6 and 5, wherein the extraction system comprises at least one extraction opening (19) formed in the frame-shaped exterior area (17) and preferably arranged centrally in a side wall (12) of the exterior area (17) and fluidically connectable to a vacuum source, wherein the at least one extraction opening (19) is fluidically connected via a channel system formed between the exterior area (17) and the interior area (14) to at least one extraction opening (15) which opens into the interior area (14) and / or to at least one extraction duct formed at least in part in the interior area (14).

8. The coating cell (2) according to claim 4, wherein the base body (5) has two adjacently arranged tub-shaped, trough-shaped or recessed interior areas (14) in preferably mirrored configuration of each other which are accommodated in a common frame-shaped exterior area (17).

9. The coating cell (2) according to claim 6 and 8, wherein the extraction system comprises at least one extraction opening (19) formed in the frame-shaped exterior area (17) and preferably arranged centrally in a side wall (12) of the exterior area (17) and fluidically connectable to a vacuum source, wherein the extraction opening (19) is fluidically connected via a channel system between the exterior area (17) and the two interior areas (14) to an extraction opening (15) which opens into a first of the two interior areas (14) as well as to an extraction opening (15) which opens into a second of the two interior areas (14).

10. The coating cell (2) according to claim 7 or 9, wherein the at least one extraction opening (15) formed in the frame-shaped exterior area (17) is fluidically connectable to an extraction system of a further base body (5) of preferably the same kind or type.

11. The coating cell (2) according to one of claims 1 to 10 and claim 4, wherein the base body (5) comprises an integrated blow-off system for the in particular need-based and preferably pulsed release of compressed air particularly along the at least one inclined or curved surface (16) and toward the extraction opening (15) or the extraction duct (6).

12. The coating cell (2) according to claim 11, wherein the blow-off system comprises at least one blow-off rail and preferably a plurality of blow-off rails, wherein the at least one blow-off rail has at least one blow-off opening which opens into the interior area (14) within an edge area of said interior area.

13. A coating system (1) for the coating and / or surface treatment of workpieces which comprises at least one coating cell (2) according to one of claims 1 to 12 and preferably at least two coating cells (2) according to one of claims 1 to 12 connected in series and to each other.

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