Device with rotary blower nozzle and linear brush for spot and area cleaning of surfaces

Abstract

A device for cleaning surfaces 1 or work areas, for example in machining or production processes such as defect removal in automotive paint lines, which are carried out manually or automatically. To reliably remove particulate contaminants such as abrasive particles 2 from surfaces 1, a device is proposed that combines wiping technology and air-based cleaning and couples their effects. A linear brush 4 is mounted on a rotary blower nozzle 6. The linear brush 4 is designed to exert a mechanical effect on the particles 2, loosening and moving them from the surface 1. The linear arrangement of the brush ensures an improved wiping effect during rotation, which loosens the particles 2 from the surface 1 upon contact with the brush filaments and simultaneously propels them outwards from the axis of rotation towards the blower nozzles 7.The blow nozzles 7 have the function of selectively agitating the particles 2 and directing them to the extraction unit 10. The size of the linear brush 4 and the position of the blow nozzles 7 are coordinated and positioned so that the particles 2 are captured and removed at the brush end by the compressed air jet 8 of the blow nozzle 7. The cleaning unit 3 is connected to an extraction unit 10 to remove the particles 2 from the work area. The device is also equipped with an extraction turbine 11. The extraction turbine 11 generates the rotation of the brush-nozzle unit 9 through the extraction airflow.

Description

[0001] The invention relates to a device for spot cleaning, also known as spot cleaning, or for cleaning surfaces or work areas in processing or production processes, such as the sanding of paint defects in automotive paint lines, whether performed manually or automatically. In this process, paint defects, such as particle inclusions from the e-coating or primer coating, are sanded out selectively using an eccentric or rotary sander. Depending on the type of defect, however, larger areas may also need to be sanded. The resulting sanding particles are potential sources of defects for subsequent painting processes and must be removed. Defects in the topcoat lead to high repair costs and, with a large number of defects, also to returns that must undergo the painting process again. State of the art

[0002] There are known methods that primarily use air-based and / or brush-based units for targeted particle cleaning on surfaces. The two methods are always clearly distinct in their effect.

[0003] From DE 102 26 808 A1 a device is known which has two parallel linear brushes and air outlets which are directed between the linear brushes towards the surface.

[0004] From DE 100 18 388 C1 a device is known which connects rotating brush heads with a suction device to extract dirt particles.

[0005] US 2006 / 0096624 A1 specifies a device suitable for cleaning machine tools and which extracts contaminants by means of a vacuum source.

[0006] DE 103 27 413 A1 describes a method for cleaning sticky and / or dried substances by means of a cleaning fluid for thermal and / or mechanical cleaning.

[0007] In many cases, the cleaning of component surfaces is still carried out manually using simple means, such as cleaning cloths. Dry microfiber cloths or those soaked in cleaning medium, as well as special adhesive cloths, are used to bind the particles. The process is time-consuming and expensive, and the cleaning results are neither reproducible nor consistent. Furthermore, the frequency of cloth changes depends on the operator. The particle-holding capacity is limited, resulting in fluctuating product quality.

[0008] The problem with known cleaning devices is that the systems available on the market do not achieve satisfactory cleaning and may also endanger the health of employees, for example through particles or vapors that are stirred up and released into the environment during the cleaning process.

[0009] In many finishing processes, such as in paint shops, very high costs arise from repairing defects caused by insufficient cleaning of grinding surfaces. Exposure to particles in the air also poses a serious threat to employee health. This problem affects a wide range of industries, including automotive, aerospace, rail, and wind power. Reliable cleaning is fundamentally important and indispensable for the function and appearance of components and therefore cannot be neglected from a quality perspective. Similar cleaning methods are also used for cleaning workplaces and processing stations.

[0010] In fully automated processes, such as automated spot sanding, small sanding areas are also created using random orbital or rotary sanders. The sanding heads are equipped with dust extraction, but the particle contamination after the process is enormous. Dust extraction alone is insufficient to reliably solve this problem. So-called cleaning pads, as commonly used in automated processes, quickly become clogged and therefore have a very short lifespan.

[0011] One way to bind the particles during the process is wet grinding, where water is applied to the surface before grinding, binding the particles. This process has the disadvantage of creating a pasty residue that is difficult to clean and requires considerable wiping force to remove the particles. Task

[0012] The objective is to enable reliable and consistent surface cleaning while reducing particle contamination on the product and in the surrounding environment. The device should be suitable for both manual and automated processes.

[0013] Exemplary embodiments of the invention are described below and illustrated in the accompanying drawings. The drawings explain the structure and operation of the invention. Fig. Figure 1 shows a cross-section of the device as a cleaning unit 3 with brush-nozzle unit 9, extraction turbine 11 and brush seal 5 with indicated exhaust air flow as extraction 10. Fig. Figure 2 shows the side view of the brush-nozzle unit 9 and the position of the compressed air jets 8 that capture the particles 2 conveyed outwards. Fig. Figure 3 shows a top view of the brush-nozzle unit 9 with the position of the linear brush 4 and the blow nozzles 7. Fig. Figure 4 shows an example of a modular structure consisting of several cleaning units as a matrix, Fig. Figure 5 shows the combination with linear brush 4 and abrasive 13 as well as the gap for particle transport.

[0014] To enable the targeted cleaning of surfaces 1 or work areas and to reliably remove particulate contaminants such as abrasive particles 2 from surfaces 1, a device is proposed that combines wiping technology and air-based cleaning, thus coupling their effects. A linear brush 4 is rotated horizontally and is preferably attached to a rotary blower nozzle 6, forming a nozzle-brush unit 5. During cleaning, the linear brush 4 is in contact with the surface 1 and is intended to exert a mechanical effect on the particles 2. The linear arrangement of the brush ensures an improved wiping effect during rotation, which loosens the particles 2 from the surface 1 upon contact with the brush filaments and simultaneously transports them outwards from the axis of rotation towards the blower nozzles 7. This removal of the particles 2 enhances the cleaning effect.At high speeds, centrifugal force is also used to accelerate the particles 2 outwards. The blow nozzles 7 are preferably located at both ends of the linear brush 4 and serve to selectively agitate the particles 2 and direct them to the suction unit 10. The size of the linear brush 4 and the position of the blow nozzles 7 are coordinated and positioned so that the particles at the brush end are captured and carried away by the compressed air jet 8 from the blow nozzle 7. The compressed air jet 8 is preferably adjusted so that the air jet deflected from the surface 1 carries the particles upwards towards the suction unit 10. The cleaning unit 3 is connected to a suction unit 10 and seals against the surface 1 sufficiently to prevent the particles from being blown out. The seal can be, for example, made of a flexible material.This is achieved by a brush seal 5, which can ensure an airflow from the outside to the inside in order to avoid a negative pressure and subsequent suction of the unit.

[0015] The device can also be equipped with a suction turbine 11. The suction turbine 11 generates the rotation of the brush-nozzle unit 9 through the existing suction flow. The turbine wheel can be constructed as a circular ring around the rotary blower nozzle 6. This design eliminates the need for an additional motor for rotation, and the blower nozzles 7 do not need to be used to generate the rotation and can therefore be switched on separately. For the cleaning function, the separate switching of the blower nozzles 7 is fundamentally important, as the blower nozzles 7 must only be switched on after the unit has been placed on the object to prevent the dirt from being distributed into the work area.

[0016] The compressed air jet 8 can be adjusted via the nozzle diameter and adapted to the application and the extraction flow. This is important to prevent particles 2 from being blown through the seal into the working chamber, thus ensuring the cleanliness of the working chamber. In certain applications, it may be necessary to adjust the spray angle of the blow nozzle 7 or, if necessary, make it adjustable.

[0017] By moving the device, as a single cleaning unit 3, on the surface 1, a surface cleaning can also be achieved.

[0018] Furthermore, the simple design of cleaning unit 3 allows for the construction of a very lightweight device, which is a very user-friendly solution that can also be used for collaborative robots with low payloads.

[0019] Depending on the cleaning process, the requirements for the linear brush 4 or the blow nozzle 7 may change, and the process parameters must be adjusted to achieve reliable cleaning. To achieve adequate cleaning, the device can be expanded and combined with brush-nozzle units 9 as needed.

[0020] Depending on the cleaning process, the requirements for cleaning unit 3 may change, and the process parameters must be adjusted to achieve reliable cleaning. To achieve sufficient cleaning, the number of cleaning units 3 can be expanded as needed, allowing for the construction of a linear cleaning unit 3 or any other shape, such as a matrix. This modular design enables the creation of a more complex unit.

[0021] In addition, for further improvement and adaptation to the product surface 1, the individual modules can be movable and close the gap to the surface 1 flush even with complex 3D contours. The brush-nozzle units 9, or the modules or parts thereof, are spring-mounted to adapt individually to the contour of the object.

[0022] Depending on the geometry of the components, it may be advantageous if the modules are designed to be movable relative to each other, in order to align and orient the cleaning unit 3 for the application.

[0023] In order to be able to react flexibly to component geometries and cleaning requirements, it is advisable to provide a control system in the device that allows the air output, the extraction flow and the rotational speed to be adjusted.

[0024] To respond with high flexibility to process requirements, the device can be used for robot-guided applications. When attached to the robot, the grinding point can be precisely targeted, or the component contours can be followed exactly.

[0025] If a controllable drive system is required for automated processes, this can also be integrated. The drive for the brush-nozzle unit 9 is then implemented using commercially available drives; hub drives, among others, are suitable for this purpose, as they allow for a compact design. With a modular design, a single drive unit can also be used for all brush-nozzle units 9.

[0026] In order to be able to react to component geometries and cleaning requirements during cleaning, it may be useful to provide a control system in the device to make the brush pressure on surface 1 adjustable and to measure and, if necessary, regulate the pressure.

[0027] Furthermore, integration into existing surface cleaning systems would also be conceivable. The device could enable targeted cleaning of problem areas or peripheral zones requiring improved cleaning within existing systems.

[0028] The blow nozzle 7 for generating the compressed air jet 8 of the present invention and the rotary blow nozzle 6 are also units that can be operated with other media, in particular gases, but also liquids. The device can therefore also be used for any type of contamination, including filmic contaminants.

[0029] The device is preferably sealed by means of a brush seal 5, but other methods are also conceivable. When using, for example, liquid media, sealing lips are also conceivable that seal completely or almost completely against the working chamber to prevent the liquid from escaping.

[0030] Furthermore, it is also conceivable that different media are used in combination or sequentially. For example, a rinsing process can be carried out with water and a drying process with air.

[0031] The linear brushes 4 are interchangeable parts. A receptacle 12 is provided on the rotary blower nozzle, allowing for easy replacement of the linear brush 4. It is conceivable that the linear brush 4 with receptacle 12 could be supplied as an interchangeable part that could then be replaced automatically. Applications with a hook-and-loop fastener or other quick-change systems are also possible.

[0032] Linear brushes 4 with different filament diameters and lengths are conceivable. Depending on the scratch sensitivity of the surfaces 1 or the requirements for the wiping action, linear brushes 4 of varying hardness or softness can be used. If it appears expedient for the application, different filaments can also be combined in the linear brush 4, for example, using one or more rows with hard filaments and one or more rows with soft filaments.

[0033] The choice of material for the linear brush 4 depends on the application and can also be combined. Different brush elements can be used, and the linear shape can also be created by brush elements.

[0034] If it is advantageous for the application to integrate the grinding process directly into the cleaning unit 3, the interchangeable part can consist of a combination of different materials, incorporating abrasive elements. For example, one or more rows of filaments can be used for cleaning, and one or more rows with an abrasive 13. The abrasive element could also be pneumatically advanced and retracted. In this configuration, the abrasive element would engage first in the direction of rotation, followed by the linear brush 4. With such a configuration, it is advantageous to provide a gap between the rows to ensure the removal of the particles 2.

[0035] In addition, the device can be further improved by having a self-cleaning unit 3 for each linear brush 4 in the cleaning unit 3. The self-cleaning of the linear brush 4 can be enabled by one or more scraper blades, which are preferably pivotable and can be engaged as needed. During rotation, the linear brush 4 moves over the scraper blade and wipes off the particles 2.

[0036] Furthermore, self-cleaning can also be carried out by an air pulse via a compressed air nozzle, which is installed laterally and creates a snapping effect on the filament through the brush rotation.

[0037] For self-cleaning of the brush seal 5, it is conceivable that an additional compressed air nozzle for cleaning the brush seal is installed on the brush-nozzle unit 9.

[0038] A holder is also provided, which also functions as a cleaning station and enables self-cleaning of cleaning unit 3. Cleaning unit 3 is connected to the self-cleaning station, switched on, and blown out with clean air, and the brush filaments are preferably cleaned with mechanical scrapers.

[0039] For 3D components with high tolerances or complex contours, it can be advantageous to use longer filaments to accommodate contour changes via the linear brush 4. To be able to change the filament lengths on an existing brush-nozzle unit 9, it is beneficial if the angle of the blow nozzle 7 is adjustable. When changing the filament lengths, the sealing or self-cleaning components must also be adaptable. Reference symbol list 1 surface 2 particles 3 cleaning units 4 linear brush 5 brush seals 6 rotary blower nozzles 7 Blower nozzle 8 compressed air jet 9 brush-nozzle unit 10 Extraction 11 Extraction turbine 12 recording 13 abrasives 14 Particle transport direction

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