Device and method for assessing coating quality

Abstract

A device (10) for evaluating the quality of a coating (12) of at least one surface (14) of a component (16), wherein the surface (14) is arranged in a cutout (18) and / or on an outer edge (20) of the component (16), the surface (14) forms a peripheral edge (22) and the component (16) is at least partially made of an at least translucent, in particular transparent material. At least one light source (24) and at least one cover (38) are proposed which are configured such that the component (16) can be illuminated by light (28) from the light source (24) and the cover (38) can protect the surface (14) from direct light (26). Furthermore, the invention relates to a method for evaluating the quality of a coating (12) of a surface (14) of a component (16) with such a device.

Description

TECHNICAL FIELD

[0001] The invention relates to a device for evaluating the quality of a coating on a surface of a component. The surface is arranged in a cutout of the component and / or on an outer edge.

[0002] Furthermore, the invention relates to a method for evaluating the quality of a coating of such a surface using the device according to the invention. BACKGROUND

[0003] Components made of at least translucent material, for example polycarbonate or similar plastics, are known in the automotive industry. These components are used, for example, as bumpers or other components of the outer shell of a vehicle, for example the bodywork. The components are usually coated to protect them from external influences. External influences can be, for example, bad weather, salt water, solvents or cleaning agents.

[0004] In particular, the coating of the plastic component can be on one side or on both sides. A single or multiple coating, even a three-layer coating, can be applied to increase the resistance to scratches and environmental influences and can serve as a carrier for paint. The coating can be based on polyurethane (PUR), for example.

[0005] In order to finally complete the manufacture of the component used as the outer shell of a vehicle, cutouts are usually made in the component after this. They can serve to secure a holder, for example a license plate holder, or to secure a lighting element, an actuator or a sensor. The cutouts made subsequently can result in openings or holes, for example, which make up a maximum of 10% of the surface of the component. The cutouts can be milled, for example. The cutouts are bounded by edges cut out of the material of the component. The base material of the component, for example polycarbonate, has no coating on these cut edges. Therefore, these cut edges have to be coated again after the cutout has been made. The aim is therefore to cover the entire surface of the cut edges without defects or exposure of the base material. Only then can the base material of the component, for example polycarbonate, be effectively protected from external influences, even in the area of the cut edges, and its service life can be extended.

[0006] In general, there is a risk that the previously applied planar coating can loosen and / or be penetrated by moisture in the area of the cut edges. This risk exists in particular if the coating subsequently applied to the cut edges is defective and not continuous. The moisture would then attack the polycarbonate of the component. It is also important to seal the cut edges optimally in order to prevent the electronic devices behind the shell or in the recess from becoming damp. These electronic elements can be, for example, radar, lidar, cameras and the like. It is therefore also necessary to protect these electronic elements from damage. The correct orientation of sensors or actuators in the openings is also important, as they can be damaged by the ingress of dust or moisture.

[0007] It is common to apply the coating on the cutting edge area of the cutout using an applicator such as a brush or a sponge. The amount of varnish or of the adhesion primer that can be metered in the applicator is known. However, the amount of primer and varnish applied onto the surface to be coated cannot be controlled. Therefore, the applied coating must be checked afterwards.

[0008] Inspection methods for evaluating the quality of the coating are known in the prior art. Visual inspection is thus possible, but visual inspection does not give reliable results and cannot be used systematically in the manufacturing process. Generally, other inspection methods lead to destruction. Therefore, until now, random optical inspection has been carried out on individual parts, or individual parts have been randomly placed in a solvent to verify the integrity of the coating. However, if the coating is defective, these tested parts are destroyed by the solvent. The tested parts cannot be repaired or reused afterwards.

[0009] Another disadvantage of these inspection methods is their high cost, since the coating defects must be detected by an operator after insertion into the solvent. SUMMARY

[0010] It is therefore an object of the present invention to provide a method and a device for evaluating the quality of a coating that overcomes the above-mentioned disadvantages.

[0011] This object is achieved by a device for evaluating the quality of a coating on at least one surface of a part, wherein the surface is arranged in a cutout of the part and / or on an outer edge, the surface forms a peripheral edge, and the part is at least partially made of at least translucent, in particular transparent, material, the device comprising at least one light source and at least one cover, configured such that the part can be illuminated by light from the light source, and such that the surface can be protected from direct light by the cover, such that light can be coupled into the material and can only be transmitted indirectly through the material of the part to the surface forming the peripheral edge, and such that the quality of the coating can be evaluated by detecting the light that has passed through the coating of the surface.

[0012] The surface thus forms a peripheral edge of a cutout of the part, and / or forms a peripheral edge on an outer edge of the part.

[0013] The device can comprise further optional features, used individually or in combination:

[0014] The device comprises at least one light sensor arranged in the vicinity of the surface in the cutout and / or on the outer edge, such that the light sensor can detect the light that has passed through the surface from an external position of the part, and a processing unit that can evaluate the quality of the coating according to the signal from the light sensor.

[0015] - the light sensors are rotatable and / or movable and are able to scan the surface at least in the appropriate area.

[0016] - at least two, in particular at least four, light sensors are arranged spaced apart from and / or inclined to each other along the surface, the surface preferably having the shape of a complete circumference.

[0017] - a light-diffusing element is provided in the vicinity of the surface, which directs the light passing through the coating to at least one light sensor.

[0018] - a cover is applied on an adjacent surface adjacent to the surface to be evaluated, in particular on both sides on an adjacent surface adjacent to the outer edge or the hollow, the cover in particular being formed on a face facing the surface of the component so as to be totally reflective at least in certain areas, in particular having a specular reflection in certain areas.

[0019] The object is also achieved by a method for evaluating the quality of a coating of a surface of the above-mentioned type, in which the surface is arranged in a hollow of a component and / or on an outer edge and forms a peripheral edge, in which an adjacent surface adjacent to the surface is at least covered in an opaque manner with a cover, in particular on both of its faces, light from a light source is coupled into a transparent or translucent material, in particular polycarbonate, and / or light from a light source is coupled into a multi-layer material or surface-coated material of the component, the quality of the coating being evaluated by detecting light passing through the coating of the surface.

[0020] The method can comprise other optional features used individually or in combination:

[0021] - the coating is at least partially transparent, opaque, in particular black, and preferably a polyurethane-based coating, and the quality evaluation is carried out based on the amount of light passing through the coating of the surface, in particular the variation in the thickness of the coating is evaluated according to the variation in the detected light intensity.

[0022] - the light is coupled into the component through a transparent surface and is conducted to the surface, in particular, the light from the light source is coupled in the direction of the surface at an angle of total reflection with the material in an angular range of 20° or less, in particular 10° or less.

[0023] - the at least one light sensor determines the amount and / or position of the light passing through the surface to determine the thickness and / or position of the coating of the surface at the defect.

[0024] - 100% inspection is carried out on all components and production defects of the system are evaluated by position determination, in particular defects in the application of varnish and / or impregnation / vernisseuse process.

[0025] - the thickness of the component is small, said surface forming the peripheral edge forms a relatively small surface in relation to the total area of the component in a ratio of at least 1 : 100, preferably 1 : 1000, in particular 1 : 5000.

[0026] - at least one light sensor is arranged in the vicinity of said surface forming the peripheral edge, in particular a rotatable or movable light sensor, and / or a plurality of light sensors spaced apart from one another or inclined to one another, in order to determine the position at which light passes through the coating.

[0027] - the light source provides different colors of light from infrared to ultraviolet, and / or variable intensity, in particular light suitable for the material of the component and / or the coating.

[0028] - the assessment of the quality of the surface coating takes place in a completely dark room.

[0029] It is the object of the present application to provide a device for assessing the quality of a coating on at least one surface of a component. The surface is arranged in a cutout of the component and / or on an outer edge and forms a peripheral edge. The component is at least partially made of a translucent, in particular transparent, material.

[0030] It is proposed that the device comprises at least one light source and at least one cover, which is configured in such a way that the component can be illuminated by light from the light source and the cover can protect the surface from direct light. Thus, light can be coupled into the material and can only be transmitted indirectly to said surface forming the peripheral edge by the material inside the component. Moreover, the quality of the coating is assessed by detecting light passing through the surface coating.

[0031] For example, the quality of the coating of a plurality of surfaces can be assessed by providing at least one cover as described above for each surface. This makes it possible to check a plurality of surfaces at almost the same time, for example using only one light source. Thus, at least one surface is the surface to be specifically examined. It can also be referred to as the test surface.

[0032] The component can be a plastic component of a housing of a vehicle, for example a bumper. These plastic components are preferably made of polycarbonate. The polycarbonate can be at least partially translucent or transparent. Polycarbonate is generally transparent.

[0033] On the other hand, the coating of the peripheral surface of the opening is preferably opaque and can consist of a varnish. Preferably, the coating can consist of a black varnish. An opaque sealant can be used as a coating. For example, it can be black and can contain up to 30% of solid particles.

[0034] Such a component made of polycarbonate can have a single-layer coating on one side (face) and a three-layer coating on the other side (face). A single-layer coating can also be applied on both sides of the component. At least one of the coatings can be made of a polyurethane material. If at least one cutout is subsequently formed in the component, or if the shape of the component, in particular the shape of the outer contour, is changed, at least one cutting edge is produced. This cutting edge is a surface or peripheral edge without a coating. A coating must then be provided on this surface in order to protect the entire surface of the component from the outside. The subsequent coating can be done with, for example, an applicator or a coater. In many cases, due to the variety of changes, it is not possible to punch or cut out in a similar way before varnishing and / or it is not economically feasible. For example, the cutouts for license plate holders vary from country to country.

[0035] With the aid of the device according to the application, it is possible to check whether the subsequently applied coatings and the coating of the component itself are free of defects. Thus, in particular, it is possible to detect locations where there is no coating, i.e. no clear varnish has been applied. In addition, the device described is also able to detect locations where the coating is very thin. In particular, the coating of the cutting edge region, i.e. the peripheral edge, can be checked. For this purpose, the component is illuminated with at least one light source and the light is thus coupled into the material of the component. Before this, the region with the cutting edge is to be protected from direct light. This is achieved by at least one cover along the peripheral edge.

[0036] For example, if the component has one cutout with a peripheral edge that is coated with a coating, a certain type of plate can be placed on the cutout. The plate forms a cover. The plate should be slightly larger than the cutout in order to protect the peripheral edge from direct light from the light source. Preferably, a cover is installed on each side of the component, i.e. on each side of the cutout. In this way, it is possible to avoid direct light on the peripheral edge on both sides of the component. In other words, the entire cutout can thus be protected from direct light. If the outer contour of the component is subsequently changed, the cutting edge is not in a recess, but in the peripheral region of the component. In order to check the quality of this peripheral edge, it must be completely covered by a cover. In this case, the cover can be designed, for example, in the shape of a "U".

[0037] The cover preferably comes into contact with the upper or lower surface of the component. In the case of a cover for a peripheral edge in the peripheral region, the cover can come into contact with both the upper and lower side (face) of the component. Direct light can thus be avoided. The cover creates a dark chamber. Advantageously, the cover does not come into contact with the surface whose quality is to be assessed. This region must remain free of contact in order to detect light through it.

[0038] Since the component is at least partially translucent, it is preferred that light can only pass through the component to the surface whose quality is to be checked. The light is thus coupled into the material. Preferably, the light enters the component through a surface which does not have a coating, in particular a surface which does not have an opaque coating. For example, it can be the outer edge of the component. Likewise, the component can have a coating only on one face, in particular an opaque face. In this case, the light can be coupled into the material through the uncoated surface and pass through the material to the surface under examination. It is thus advantageous if the material is at least partially transparent or translucent.

[0039] The quality of the coating is assessed by detecting the light which passes through the surface coating. This is preferably done from the outside of the component. This can be performed using a photodetector, a camera or similar device, but it is also possible to perform the inspection using the naked eye, for example. From the outside of the component, it can be assessed whether the light is passing through the coating on the surface or on the peripheral edge. In other words, on the side of the coating which is in contact with the material, light is directed through the material towards the coating. On the other side of the coating (outside the surface), the quality of the coating is assessed. This is achieved, inter alia, by the fact that light which has passed through the coating can be detected on this side. If light is detected, this indicates that the coating has a defect. The defect can be, for example, a void, i.e. a hole in the coating. Likewise, the defect can be an area of the coating which is too thin, through which a small amount of light can shine through.

[0040] Using the above-described device, for example, it is possible to easily and quickly check 100% of all manufactured components in a continuous flow production process. It is particularly advantageous that the inspection does not result in damage. After a defect has been detected (for example a hole in the coating or an area of the coating which is too thin), the component can be repaired, for example the coating can be reworked. Thus, there is no waste, since all components can be reused or repaired.

[0041] Advantageously, the above-described device enables systematic defects on the re-coated surface or peripheral edge to be detected in the production flow. For example, a defect in the system can be inferred from an error in the application of the varnish by the varnish applicator or dip / paint machine. If at least three components still have the same defect or the degree of the defect in the coating tends to worsen, it can be concluded that it is a systematic defect. If the components are checked immediately after the coating has been applied using the proposed device, it is possible to immediately change or correct the varnish applied by the varnish applicator. Thus, further defects in the coating of further components can be quickly and easily avoided.

[0042] In a preferred embodiment, at least one light sensor and an evaluation unit can be provided, which light sensor is arranged in the hollow space and / or near the surface on the outer edge. This allows the light sensor to detect light passing through the surface from a position outside the component. Furthermore, the evaluation unit can perform an evaluation of the coating quality based on the signals from the sensor. The light sensor is preferably located in a region which is protected from direct light. Thus, the light sensor can only detect light which has passed through the surface, i.e. the peripheral edge. Preferably, the light sensor can be calibrated such that it can be used for a quality evaluation of the entire peripheral edge. On the other hand, the evaluation unit can be placed anywhere, including outside the hollow space. The light sensor used can typically be a photoelectric component, such as a photoresistor, but also a camera, preferably a camera of a portable computer, such as a smartphone, a tablet, etc. It is even possible to include the human eye as part of the manual control.

[0043] In a preferred embodiment, the light sensor is rotatable and / or movable and scans the surface at least in appropriate regions. Such a light sensor can be used, for example, for a hollow space having a circumferential edge, in particular a circumferential edge having a completely circular circumference. When scanning a circumferential surface, the light sensor is preferably rotated at least 360° at a time. Thus, the coating quality can be evaluated over the entire surface, and the angular position and / or coordinates can also be used to identify the location of a defect. It is also possible to move the light sensor along the surface on the peripheral edge of the component in order to determine the location of a defect. This results, for example, if the geometry of the component, in particular its outer contour, is subsequently changed. For example, a programmable robot can be provided to move the light sensor along the surface. Thus, the quality of the coating can be tested for a series of convex and concave peripheral edge contours. For irregular routes, a coordinate-based guidance can be used.

[0044] Advantageously, the light sensor can be arranged in the form of a photoresistor.

[0045] In a preferred embodiment, at least two, in particular four or more, light sensors are arranged at a distance from and / or inclined to each other along the surface. In this way, the surface can preferably be in the shape of a complete contour. For example, in the case of a hollow space, three, in particular four, light sensors can be arranged within the hollow space. Preferably, the light sensors are arranged at the same distance from each other. For example, in the case of four light sensors, each light sensor can be used to evaluate the quality of a quarter of the surface in order to determine the location of a defect in the coating.

[0046] In a preferred embodiment, a light-diffusing element is provided adjacent to the surface, which light-diffusing element can conduct light passing through the coating to at least one light sensor. The light-diffusing element can be, for example, a prism or a similar type of light-conducting element, which is capable of conducting light along the peripheral edge, in particular along the entire peripheral edge, a certain distance towards the light sensor.

[0047] In a preferred embodiment, a cover is applied to an adjacent surface adjacent to the surface forming the peripheral edge to be evaluated. In particular, the cover can be applied from both sides to the adjacent surface adjacent to the outer edge or the undercut. In this way, the cover, in particular the cover on the side facing the surface of the component, can be totally reflective in certain areas, in particular specularly reflective in certain areas. The adjacent surface is preferably located on the top surface or the bottom surface of the component. Preferably, the adjacent surface is aligned approximately perpendicularly to the surface forming the peripheral edge. In order to direct light in the direction of the surface forming the peripheral edge, the cover can be totally reflective on certain areas of the bottom surface. Preferably, this totally reflective area is located where the cover is in contact with the adjacent surface. In particular, the cover should not be totally reflective or specularly reflective in the area of the free surface, in particular on the surface area with the coating, i.e. the peripheral edge. Due to the totally reflective properties of the cover, light is particularly effectively directed to the edge with the coating in order to detect defects by high light intensity.

[0048] It is also an object of the application to a method for evaluating the quality of a surface coating, which surface is arranged on an undercut and / or an outer edge of a component. The surface thus forms a peripheral edge as described above.

[0049] An adjacent surface of the surface is covered in an opaque manner by the coating, in particular on both sides. In this way, light from the light source is coupled into the transparent or translucent material. In particular, the light is coupled into the polycarbonate of the component and / or into a multi-layer material or into a material with a surface coating. The quality of the coating is evaluated by detecting light that penetrates the coating from the surface.

[0050] Such a method can be used to detect components, for example in the outer skin of a vehicle. Such a component is, for example, a polycarbonate bumper with an opaque coating. The material of the bumper is preferably transparent or translucent. The coating can be single-layered or multi-layered and consists of a polyurethane material. Preferably, the coating is opaque. The subsequent milling of the undercut or the peripheral edge after machining can result in a cutting edge without coating.

[0051] As with the described device, the method makes it possible to check for coating defects. The above-mentioned implementation variants and advantages also apply to the method.

[0052] In a preferred embodiment of the method, the coating is at least partially or locally translucent, opaque, in particular black. Preferably, the coating is a polyurethane-based coating. A quality assessment can be made on the basis of the amount of light that penetrates the surface coating. In particular, a thickness of the coating can be assessed during the quality assessment since a change in the detected light intensity can be evaluated on the basis of which a thickness change of the coating can be assessed. For example, for a desired layer thickness, a corresponding limit value of the light intensity or light amount is determined. If there is a deviation between the measured light amount and this limit value, a defect can be detected, for example that the coating is too thin. If a region of the coating is detected to be too thin, a value of the light intensity above the limit value can be considered a critical value. The component coating can then be reworked in this region, for example a further layer of coating material can be applied. By using varying amounts of light and determining the light limit value, the required coating thickness can also be assessed.

[0053] In a preferred embodiment of the method, light can be coupled into the component through the transparent surface and directed at the surface. In particular, light from the light source can be coupled in a range of angles less than or equal to 20°, in particular less than or equal to 10°, with respect to the total reflection angle of the material, and in the direction of the surface. When the angle of incidence of the light reaches the total reflection angle, the light no longer refracts, but is totally reflected. Within the range of the total reflection angle, the light is directed almost parallel to the boundary surface and can thus be directed with high intensity to the peripheral edge. It can thus be ensured that light can be directed through the material of the component to the surface whose quality is to be checked. Advantageously, light from the light source can also be coupled directly into the surface of the material by means of a light coupling structure, the optical properties of which are oriented towards the peripheral edge with the coating to allow light to be directed purposefully through the material to the peripheral edge with the coating. The light coupling structure can have the same optical properties as the material of the component to be detected or changed optical properties.

[0054] In a preferred embodiment of the method, the at least one light sensor is able to determine the amount and / or position of light that passes through the surface. This allows the thickness and / or position of the coating at a defect on the surface to be detected. A defect signal or a gradual deterioration of the defect signal from the at least one light sensor makes it possible, for example, to deduce the beginnings of a systematic varnish application error of a varnish applicator or a dip / paint machine.

[0055] In a preferred embodiment of the method, 100% of all components can be inspected. Furthermore, systematic production errors can be assessed from the position detection. In particular, this enables the assessment of incorrect application of varnish applicators and / or dip / paint machines. For example, if the same or a gradually worsening defect is always detected on the coating at the same position, it can be assumed that the defect is systematic on the system. For example, if the coating of at least three parts has the same defect or a tendency to develop a defect, the defect is considered to be systematic. The proposed method is non-destructive. Therefore, all parts can be checked using the method. Defective parts can then be repaired without having to be discarded.

[0056] In a preferred embodiment of the method, the components are of small thickness. The surface forms a relatively small surface area in relation to the total area of the component, at a ratio of at least 1 : 100, preferably 1 : 1000, in particular 1 : 5000. The geometry can be designed as a plate. The polycarbonate component can be manufactured by injection molding.

[0057] In a preferred embodiment of the method, at least one light sensor is arranged near the surface forming the peripheral edge. In particular, rotatable or movable light sensors and / or a plurality of light sensors spaced apart or inclined relative to each other can be provided. The light sensors are preferably used to determine the position of the light passing through the coating. In the case of a cutout, for example, three, in particular four, light sensors can be arranged within the cutout. The light sensors are preferably arranged at the same distance from each other.

[0058] In a preferred embodiment of the method, the light source can provide light of different colors. In particular, the light source can provide light suitable for the material of the component and / or the coating. These lights can be, for example, rays from infrared to ultraviolet and / or rays of varying intensity. In this way, the light used can be adapted to the transparency of the coating to be detected. In this way, it is also possible to detect coatings that only protect against light in a specific wavelength range. Thus, when measured using light in this wavelength range, defects in the coating can be detected.

[0059] If necessary, light can also be coupled into the material from the cutting edge, i.e. the surface of the peripheral edge, and light passing through the coating of the peripheral edge from the outside into the material is detected, in particular from the outside along the outer contour, i.e. an inversion of the above-mentioned principle.

[0060] Advantageously, the quality assessment of the coating of the surface is carried out in a completely dark room. This virtually eliminates the possibility of evaluation errors due to scattered light and external light. In addition or alternatively, a threshold value of the variation in the amount of light can be considered to reliably assess defects in the coating. In particular, infrared light can be used, or a light color is chosen that is not or hardly present in the ambient light.

[0061] With the aid of the device and the method for evaluating the coating quality of the cutting edge of a plastic component of a vehicle's outer skin, penetration and damage to the surface coating on the plastic component can be effectively prevented, since the cutting edge can be completely controlled and effectively sealed by the coating of the peripheral edge. BRIEF DESCRIPTION OF DRAWINGS

[0062] Further advantages are shown in the drawings and the drawing description. The drawings show examples of embodiments of the invention. The specification and the claims contain many features in combination. The person skilled in the art will also consider the individual features appropriately and combine them into other meaningful combinations.

[0063] The invention will be better understood by reading the following description, which is given solely by way of example and with reference to the appended drawings, in which:

[0064] Figure 1 is a plan view of an embodiment of the device according to the invention or of the method according to the invention with components;

[0065] Figure 2 is a sectional view of Figure 1 ;

[0066] Figure 3 is a detail view of the sectional view of Figure 2 ;

[0067] Figure 4 is another embodiment of the device according to the invention or of the method according to the invention;

[0068] Figure 5 is a detail view of another embodiment of the device according to the invention or of the method according to the invention;

[0069] Figure 6 is a detail view of another embodiment of the device according to the invention or of the method according to the invention. DETAILED DESCRIPTION

[0070] In the drawings, identical or similar components are numbered with the same reference numerals.

[0071] Figure 1The detailed embodiment shows a plan view of an embodiment of the device 10 according to the invention or the method according to the invention, having a component 16. By way of example, a circular component 16 is shown having a circular cutout 18. The cutout 18 is covered by a circular cover 38. Thus, the diameter of the cover 38 is larger than the diameter of the cutout 18. Surface 14 is milled in component 16 into a cutout for a functional component, such as a radar sensor, and is provided with an opaque coating 12 as a protective layer. The cover 38 protects surface 14 from direct light. This is possible because the cover 38 is opaque. In this illustration, the cutout 18 is located behind the cover 38 and is therefore shown in dashed lines. In this embodiment, four light sensors 32 are arranged in the cutout 18. Since they are also arranged behind the cover 38, they are also shown in dashed lines. The light sensors 32 are aligned with surface 14, which represents its peripheral edge 22. The coating 12, whose quality is to be evaluated, is on surface 23 of the peripheral edge 22. In this embodiment, the surface of component 16 shown above is a transparent surface 36. It could also be a translucent surface 36. This means that there is no coating on this surface, especially an opaque coating. Instead, the outer edge of the circular component 16 has a coated surface 37. Therefore, when light 26 passes through this surface in the above figure, light 28 can be introduced into the material of component 16 and reach surface 14 from there. Therefore, it is particularly important that the cover 38 completely covers the cutout 18.

[0072] Figure 2 It is along Figure 1 A cross-sectional view along axis AA. The same features are referred to by the same reference numerals, so there is no need to repeat the description. This figure shows another cover 38 arranged below component 16 at the location of the cutout 18. Therefore, a dark chamber enclosed to 3 / 4 (three-quarters) can be formed in the area of ​​the cutout 18. In this embodiment, component 16 also has a coating on its lower surface, as shown by surface 37 with the coating. Therefore, a light source 24 is positioned on one side of component 16 with the transparent surface 36. In this embodiment, there are three light sources 24 that emit light 28 at different angles above component 16 toward the coated surface 14. Here, direct light irradiation 26 occurs from the respective light source 24 to the transparent surface 36 of component 16. The light 28 is coupled into the material through the transparent surface 36. In the material of component 16, the light 28 indirectly passes through the interior of the material toward surface 14. Therefore, the entire surface 23 of the peripheral edge 22 can be reached. In this cross-sectional view, two light sensors 32 are visible inside the cutout 18. These light sensors 32 are able to detect light 28 entering through the surface 14 from a position outside the component 16, in this case in the cutout 18.

[0073] Figure 3 It shows Figure 2a detailed view of the cross-sectional view. In this illustration, it can be seen that the coating 12 on the surface 14 has a defect, for example a hole, at a location 30. At this location 30, light 28 passes from the interior of the component 16 through, penetrates the coating 12 and enters the hollow 18. This light 28 can thus be detected by the light sensor 32 (not shown in this illustration). The illustration also shows two covers 38 in contact with the component 16 in the area of adjacent surfaces 42. These adjacent surfaces 42 can be fully reflective or mirrored at least in certain areas. In this way, the coupled light 28 present in the component 16 can be optimally directed onto the surface 14. The free surface 44 of the covers 38 does not have such fully reflective or mirrored areas, since the light 28 in this area should be located directly at the location 30.

[0074] Figure 4 Another embodiment of the device 10 according to the application or of the method according to the application is shown. Unlike the embodiment shown in Figure 2 the illustration, this embodiment integrates an evaluation unit. The evaluation unit is coupled with the light sensor 32 and the light source 24. The evaluation unit 40 can automatically evaluate the quality of the coating on the basis of at least one sensor signal from at least one light sensor 32. The quality evaluation can be carried out on the basis of the amount of light 28 that passes through the coating 12. Even in the case of a change in light intensity, the thickness of the coating 12 can be detected if a limit value of the light detected by the light sensor 32 is detected for a certain amount of light from the light source 24. In other words, for a certain amount of light or light intensity emitted by the light source 24, a change in the thickness of the coating 12 is evaluated on the basis of a change in the detected light intensity. For example, the thickness of the coating can be determined for each location on the surface 14. The exact location of the defect location of the coating 12 can also be determined. The component 16 whose coating 12 is defective can then be reprocessed and reused.

[0075] Figure 5 and Figure 6 Further detailed views of further embodiments of the device 10 according to the application or of the method according to the application are shown.

[0076] As Figure 5 shown, a single light sensor 32 is located in the centre of the hollow 18. The light sensor 32 is rotatable and can completely scan the surface 14. For example, if the surface 14 is formed as Figure 1 shown, the light sensor 32 can reach any location of the surface 14 by a rotation of, for example, 360°. In this embodiment, the covers 38 are only provided in the upper region of the component 16 or of the hollow 18. This is possible, for example, if the component 16 rests on a support (not shown). Unlike the embodiment with reference to Figures 1-3In the embodiment shown, the component 16 has a surface 37 with a coating on the bottom side. In contrast, in the region of the thickness of the component 16, the outer surface is formed as a transparent surface 36. Thus, light 28 is coupled into the material through this transparent surface 36. In this figure, the coating 12 of the surface 14 has a defect at a position 30 in the upper region. At this position 30, light 28 can enter into the region of the cutout 18. The light sensor 32 is able to detect this position 30.

[0077] Figure 6 The outer edge 20 of the component 16 is shown. This outer edge can be created, for example, if the geometry of the component 16, in particular its outer contour, is changed after manufacture. Thus, there is no opening. The cover 38 is thus "U" shaped and in contact with the upper and lower side of the component 16. Thanks to the "U" shape of the cover 38, a dark chamber can be formed which is closed at 3 / 4 (three quarters) and completely surrounds the surface 14. In this embodiment, for example, a plurality of light sensors 32 can be arranged along the outer edge 20 at a distance from one another. This makes it possible to evaluate the quality of the entire surface 14 or of the coating 12.

[0078] The embodiments shown can of course be combined with one another to create further exemplary embodiments. In particular, the geometry of the component 16 can be different. The component 16 can be made of, for example, polycarbonate or a similar material. The device 10 and the method are particularly suitable for the overall inspection of plastic components in the automotive sector. These plastic components can be, for example, bumpers or other components of the vehicle shell, or interior lining elements which comprise cutouts with a coating for receiving sensors, actuators or other functional elements of the vehicle.

[0079] List of reference signs

[0080] 10: device

[0081] 12: coating

[0082] 14: surface

[0083] 16: component

[0084] 18: opening

[0085] 20: outer edge

[0086] 22: peripheral edge

[0087] 23: surface of the peripheral edge

[0088] 24: light source

[0089] 26: direct light radiation

[0090] 28: light

[0091] 30: position

[0092] 32: light sensor

[0093] 34: complete circumference

[0094] 36: transparent / semi-transparent surface

[0095] 37: surface with coating

[0096] 38: covering

[0097] 40: evaluation unit

[0098] 42: adjacent surface

[0099] 44: free area

Claims

1. An apparatus (10) for coating (12) quality assessment, the coating being on at least one surface (14) of a component (16), wherein, The surface (14) is arranged in a cutout (18) and / or on an outer edge (20) of the component (16), the surface (14) forms a peripheral edge (22), and the component (16) is a component of a motor vehicle shell and is at least partially made of at least translucent or transparent material, characterized in that the evaluation device comprises at least one light source (24) and at least one cover (38) which is configured in such a way that the component (16) can be illuminated by light (28) from the light source (24) and the cover (38) can be applied to an adjacent surface (42) adjacent to the surface (14) to be evaluated in such a way that the surface (14) can be protected from direct light by the cover (38), so that light (28) can be coupled into the material and can only be transmitted indirectly through the material inside the component (16) to the surface (14) forming the peripheral edge (22), and the quality of the coating (12) can be evaluated by detection of light (28) that has passed through the coating (12) of the surface (14), wherein the device (10) comprises at least one light sensor (32) which is arranged in the vicinity of the surface (14) in the cutout (18) and / or on the outer edge (20) in such a way that the light sensor (32) can detect light (28) that has passed through the surface (14) from an external position of the component (16), and a processing unit (40) which can evaluate the quality of the coating (12) from the signals from the light sensor.

2. The apparatus (10) according to claim 1, characterized in that The light sensor (32) is rotatable and / or movable and can scan the surface (14) at least in suitable regions.

3. The apparatus (10) according to claim 1 or 2, characterized in that At least two light sensors (32) are arranged spaced apart from and / or inclined to each other along the surface (14).

4. The apparatus (10) according to claim 3, characterized in that At least four light sensors (32) are arranged spaced apart from and / or inclined to each other along the surface (14).

5. The apparatus (10) according to claim 3, characterized in that The surface (14) has the shape of a complete circumference (34).

6. The apparatus (10) according to claim 1 or 2, characterized in that In the vicinity of the surface (14) there is a light-diffusing element which directs light (28) that has passed through the coating (12) to at least one light sensor (32).

7. The apparatus (10) according to claim 1 or 2, characterized in that The cover (38) is applied to the adjacent surface (42) adjacent to the outer edge (20) or the cutout (18) from both sides.

8. The apparatus (10) according to claim 7, characterized in that The cover (38) is formed on the surface facing the surface of the component (16) in such a way that it is totally reflective at least in certain regions or has a specular reflection in certain regions. The surface (14) is arranged in a cutout (18) and / or on an outer edge (20) of the component (16), the surface (14) forms a peripheral edge (22), and the component (16) is a component of a motor vehicle shell and is at least partially made of at least translucent or transparent material, characterized in that the evaluation device comprises at least one light source (24) and at least one cover (38) which is configured in such a way that the component (16) can be illuminated by light (28) from the light source (24) and the cover (38) can be applied to an adjacent surface (42) adjacent to the surface (14) to be evaluated in such a way that the surface (14) can be protected from direct light by the cover (38), so that light (28) can be coupled into the material and can only be transmitted indirectly through the material inside the component (16) to the surface (14) forming the peripheral edge (22), and the quality of the coating (12) can be evaluated by detection of light (28) that has passed through the coating (12) of the surface (14), wherein the device (10) comprises at least one light sensor (32) which is arranged in the vicinity of the surface (14) in the cutout (18) and / or on the outer edge (20) in such a way that the light sensor (32) can detect light (28) that has passed through the surface (14) from an external position of the component (16), and a processing unit (40) which can evaluate the quality of the coating (12) from the signals from the light sensor.

9. A method of assessing the quality of a coating (12) of a surface (14) using the apparatus (10) according to any one of the preceding claims 1-8, wherein, The surface (14) is arranged in a cutout (18) and / or on an outer edge (20) of the component (16), the surface (14) forms a peripheral edge (22), characterized in that the adjacent surface (42) adjacent to the surface (14) is at least covered with a cover (38) in an opaque manner, light (28) from a light source (24) is coupled into a transparent or translucent material, and / or light (28) from a light source (24) is coupled into a multi-layer material or a surface-coated material of the component (16), the quality of the coating (12) is evaluated by detecting light (28) passing through the coating (12) of the surface (14).

10. The method of claim 9, wherein, The two faces of the adjacent surface (42) adjacent to the surface (14) are at least covered with a cover (38) in an opaque manner.

11. The method of claim 9, wherein, The transparent or translucent material is polycarbonate.

12. The method of claim 9, wherein, The coating (12) is at least partially transparent, opaque, and the quality assessment is carried out based on the amount of light (28) passing through the coating (12) of the surface (14), or the thickness of the coating (12) is evaluated according to the detected change in light intensity.

13. The method of claim 12, wherein, The coating (12) is at least partially black.

14. The method of claim 12, wherein, The coating (12) is at least partially a polyurethane-based coating (12).

15. The method according to any one of claims 9-14, characterized in that, The light (28) is coupled into the component (16) through a transparent surface (36) and is conducted to the surface (14).

16. The method of claim 15, wherein, The total reflection angle of the light (28) from the light source (24) with the material is coupled in the direction of the surface (14) in an angular range of 20° or less.

17. The method of claim 16, wherein, The total reflection angle of the light (28) from the light source (24) with the material is coupled in the direction of the surface (14) in an angular range of 10° or less.

18. The method of any one of claims 9 to 14, wherein, The at least one light sensor (32) determines the amount and / or position of light (28) passing through the surface (14) to determine the thickness and / or position of defects in the coating (12) of the surface (14).

19. The method according to any one of claims 9 to 14, characterized in that, The surface (14) forming the peripheral edge (22) forms a relatively small surface with respect to the total area of the component (16) in a ratio of at least 1:

100.

20. The method of claim 19, wherein, The surface (14) forming the peripheral edge (22) forms a relatively small surface with respect to the total area of the component (16) in a ratio of 1:1000.

21. The method of claim 19, wherein, The surface (14) forming the peripheral edge (22) forms a relatively small surface with respect to the total area of the component (16) in a ratio of 1:5000.

22. The method according to any one of claims 9 to 14, characterized in that, At least one light sensor (32) is arranged near the surface (14) forming the peripheral edge (22) to determine the position of light (28) passing through the coating (12).

23. The method of claim 22, wherein, The at least one light sensor (32) is a rotatable or movable light sensor (32), and / or a plurality of light sensors (32) spaced apart or inclined to each other.

24. The method of any one of claims 9 to 14, wherein, The light source (24) provides light (28) of different colors, or light (28) suitable for the material of the component (16) and / or the material of the coating (12), from infrared to ultraviolet, and / or variable intensity.

25. The method of any one of claims 9 to 14, wherein, The quality of the coating (12) of the surface (14) is evaluated in a completely dark room. The quality of the coating (12) of the surface (14) is evaluated in a completely dark room.

Images