SPRAY SYSTEM

Description

[0001] The invention relates to a spray system, such as in particular a powder coating or other painting system, according to the preamble of claim 1. The spray system comprises a spray booth and a conveyor device movable along a transport direction in the spray booth for transporting at least one workpiece to be coated. In addition, the spray system comprises at least one automatically movable spray gun for dispensing a coating medium, such as in particular a powder, a paint, or another sprayable medium, which is connected to a storage container for the coating medium. The at least one spray gun is held on a carrier movable in the transport direction. This allows the workpieces to be coated to remain in a substantially fixed position during a spraying process, while the at least one spray gun is moved along the respective workpiece in question.

[0002] DE4430749A1 discloses a powder coating system comprising a spray booth through which a workpiece to be sprayed can be transported suspended by means of a chain conveyor. During this transport through the spray booth, the workpiece is coated with powder particles by means of at least one stationary spray gun under the influence of an electric field. The spray gun can be automatically reciprocated during a spraying process by means of a lifting device.

[0003] A disadvantage of the known powder coating system is that, in order to completely spray a workpiece, a spray booth is required that is sufficiently large to allow the workpiece to be moved along its entire length past the movably mounted spray gun. This makes the spray booth relatively large in relation to the workpieces to be coated therein. In addition, a special support must be provided for at least one spray gun, which enables the spray gun to be mounted movably. This results in relatively high space requirements and construction costs for the known powder coating system, which also results in relatively high manufacturing costs for both the system itself and the coatings produced therein.

[0004] US 2019 / 0247884 A1 describes a system for surface treatment or surface coating of aircraft fuselages. The system comprises an arc-shaped support on which a plurality of treatment heads are arranged, each of which can be individually controlled. During treatment, the support is arranged such that it encompasses the respective aircraft fuselage. Furthermore, the support can be moved along the aircraft fuselage on floor-mounted rails.

[0005] KR 101 456 849 B1 discloses a system for painting cylindrical elements for wind turbines. The system comprises an arcuate support on which a plurality of spray heads are arranged, which can be moved along the respective element via floor-mounted rails. During treatment, the support is arranged such that it encompasses the respective aircraft fuselage. Furthermore, the element is rotatably mounted on trolleys.

[0006] EP 0 856362 A1 shows an arrangement of spray guns mounted on a common frame. The frame converts the rotational movement of a drive into an oscillating movement of the individual spray guns. The frame is also mounted on a trolley.

[0007] The object of the invention is to avoid the aforementioned disadvantages and to reduce the costs in a spray system of this type.

[0008] This object is achieved by a spray system having the features of claim 1. The carrier is held movable on the conveyor device, via which the respective workpiece can also be moved into and / or out of the spray booth. It is also advantageous if the conveyor device is arranged on a ceiling of the spray booth and the carrier is suspended from the conveyor device, which enables particularly convenient transport of the workpiece to be coated and also particularly convenient relocation of the at least one spray gun. As a result, the spray booth only needs to be dimensioned such that the workpiece to be coated can be held in a fixed position therein. This allows the spray system to be designed to be particularly compact, which in turn reduces the costs for the spray system itself and for the coatings to be produced with it.A commercially available spray gun is used, which can achieve an application efficiency of at least 30%, preferably at least 70%. In this way, existing means, such as ceiling-mounted conveyors, can also be used to relocate the at least one spray gun. This can further reduce the costs and space requirements of the spray system. Using the ceiling-mounted conveyor also has the advantage that excess coating medium can be more easily vacuumed away during a spraying process and the floor of the spray booth can be cleaned more easily.

[0009] Advantageously, the carrier is U-shaped and each of its free ends is attached to a support of the conveyor system. Both supports can be moved parallel to each other in the transport direction. This makes it possible to move two or more spray guns parallel to the workpiece, thereby coating larger workpiece surfaces. The U-shaped design of the carrier ensures a stable position of the carrier and the spray guns relative to each other during movement by the conveyor system.

[0010] In this case, it is advantageous if the U-shaped carrier encompasses a spray area in which the at least one workpiece to be coated can be secured to the conveyor. This allows the carrier to be arranged around the spray area and the workpiece held therein and to be equipped with the at least one spray gun at any desired location. This allows the position and orientation of the at least one spray gun held on the carrier relative to the spray area to be selected relatively freely.

[0011] Advantageously, the at least one spray gun can be automatically displaced on the carrier, for example, by a lateral displacement or a pivoting movement. In addition to displacing the carrier in the transport direction, the height of the at least one spray gun can also be changed in order to increase the spray area that can be covered by it.

[0012] It is particularly advantageous if at least one spray gun can be moved automatically with an oscillating movement in order to be able to produce a particularly uniform coating.

[0013] Furthermore, it is advantageous if at least two spray guns are held on the carrier, which are directed onto the spray area from different sides in order to be able to coat the workpiece simultaneously on two opposite outer sides.

[0014] It is particularly advantageous if the at least two spray guns are directed toward each other, or if their movement is coordinated or synchronized axially. This allows the displacement forces generated during spraying to be mutually canceled, which in turn allows the workpiece suspended from the conveyor to be held in a particularly stable position. Furthermore, this method can improve the distribution of electrostatic charge on the relevant outer surfaces of the workpiece.

[0015] Advantageously, the conveyor device also has at least two bearing rails extending in the transport direction, on each of which a roller assembly can be displaced by means of a cable pull. This makes it easy to implement an explosion-proof drive for the carrier. Alternatively, the carrier can also be driven by an explosion-proof electric motor.

[0016] The figures illustrate an exemplary embodiment of the invention. They show: Figure 1 is a front view of a spray system according to the invention and Figure 2 is a side view of the spray system in direction II from Figure 1 .

[0017] The Figure 1 and 2 show a spray system 2 for applying a coating, such as in particular a powder coating, to a workpiece 4. For this purpose, the spray system 2 has a housing 6 that encloses a spray booth 8. A conveyor device 12, which has a plurality of support rails 14, 16, is arranged on a ceiling 10 of the spray booth 8.

[0018] The workpiece 4 is suspended and preferably displaceably mounted on a first bearing rail 14. This first bearing rail 14 is arranged between two outer bearing rails 16, on which a carrier 18 is held. The carrier 18 is U-shaped and is held by two free ends E each on a receptacle 20 of the conveyor device 12. Both receptacles 20 have a roller device 22, which is mounted on the outer bearing rails 14 along a transport direction T (according to Figure 2 ) can be relocated.

[0019] The U-shaped carrier 18 defines along the transport direction T a spray area 24 enclosed by it according to Figure 1in which the workpiece 4 is held. In order to be able to provide the workpiece 4 completely with the desired coating, a plurality of spray guns 26 are held on the carrier 18. The spray guns 26 are preferably formed by commercially available spray guns 26 with which an application efficiency of at least 30%, preferably of at least 70%, can be achieved. All spray guns 26 are connected to a storage container 28 in which the coating medium to be applied is held, such as a powder, a lacquer, a plastic or another sprayable medium. For this purpose, the storage container 28 is held, for example, on the carrier 18 and is thus displaced together with the carrier in the transport direction T during a spraying process.

[0020] The spray guns 26 are each mounted on the support 18 in such a way that they can be moved automatically in order to increase the spraying area of ​​the individual spray guns 26. For this purpose, the spray guns 26 can be moved laterally upwards and downwards, as shown in Figure 1 represented by arrows. Alternatively or additionally, the spray guns 26 can also be pivotably mounted and driven. The spray guns 26 can, for example, be moved in an oscillating manner to enable the most uniform application of the spray medium to the outside of the workpiece 16. Furthermore, two of the spray guns 26 are directed from different sides onto the spray area 24, specifically directly toward each other, in order to mutually compensate for the respective application of a displacement force to the workpiece 4.

[0021] To control the spraying operation, all spray guns 26 are connected to one of two control devices 30, which are also carried on the carrier 18. These control devices 30 can be used to adjust and control, for example, the movement of the spray guns 26, the throughput of the coating medium from the storage container 28, and its electrostatic charge.

[0022] To perform a coating process, the workpiece 4 is moved into the spraying area 24 via the internal bearing rail 14 or suspended therein. The carrier 18, with the spray guns 26 mounted thereon, is then moved along the transport direction T. To move the carrier 18, a drive 32 acting on the roller devices 22 can be used, which drive can be formed, for example, by a cable pull or an explosion-proof electric motor.

[0023] During the movement of the carrier 18 in the transport direction T, the coating medium available in the storage containers 28, such as a coating powder, is dispensed in a predetermined amount via the spray guns 26 by means of the control devices 30 and, for example, is additionally electrostatically charged. The coating powder is deposited on the surface of the workpiece 4 and adheres to it.

[0024] The spray guns 26 are directed towards each other in pairs and are preferably oscillated back and forth in a synchronized manner to keep the workpiece 4 in a stable position and to achieve a uniform distribution of the coating.

[0025] By displacing the carrier 18 in the transport direction T along the entire length of the workpiece 4, the spray system 2 can thus completely provide the workpiece 4 with the desired coating on both sides.

Claims

1. Spraying installation (2) with a spraying cabin (8), a conveying apparatus (12) which can be moved along a transport direction (T) into the spraying cabin (8) for the transport of at least one work piece (4) to be coated, and at least one automatically moved spraying pistol (26) for outputting a coating medium, which spraying pistol is connectable to a reservoir (28) for the coating medium, wherein the at least one spray pistol (26) is held at a carrier (18) which is displaceable in transport direction (T) and is displaceable at said carrier (18) along the workpiece (4), while the workpiece (4) remains in a substantially fixed position, characterized in that the conveying apparatus (12) is arranged at a ceiling (10) of the spraying cabin (8) and the carrier (18) is held at the conveying apparatus (12) so as to be displaceable and suspended.

2. Spraying installation according to any one of claims 1, characterized in that the carrier (18) is U-shaped in shape and is fastened with both free ends (E) respectively at a receptacle (20) of the conveying apparatus (12), wherein both receptacles (20) are displaceable parallel to one another in transport direction (T).

3. Spraying installation according to claim 2, characterized in that the U-shaped carrier (18) encompasses a spraying region (24) in which the at least one workpiece (4) to be coated is fixable at the conveying apparatus (12).

4. Spraying installation according to any one of claims 1 to 3, characterized in that the at least one spraying pistol (26) is capable of being displaced automatically on the carrier (18).

5. Spraying installation according to claim 4, characterized in that the at least one spraying pistol (26) is capable of being displaced automatically with an oscillating movement.

6. Spraying installation according to any one of claims 3 to 5, characterized in that at the carrier (18) at least two spraying pistols (26) are held, which are oriented onto the spraying region (24) from different sides.

7. Spraying installation according to claim 6, characterized in that the at least two spraying pistols (26) are oriented to one another.

8. Spraying installation according to any one of claims 1 to 7, characterized in that the conveying apparatus (12) has at least two bearing rails (14) extending in transport direction (T) at which respectively one roller apparatus (22) is displaceable by means of a pull rope or an explosion-proof electric motor.