DEVICE AND METHOD FOR INSPECTING REFLECTIVE SURFACES

Abstract

A device for inspecting a surface of an object, in particular a reflective or transparent surface, including an illuminating apparatus with which the surface can be illuminated, a measuring apparatus which senses light reflected at the surface, and a vapor-application apparatus which is designed to apply vapor to the surface. To achieve an efficient application of vapor, it is provided that the vapor-application apparatus includes a nozzle, a vaporization chamber having an enclosure, and a heating apparatus. The nozzle protrudes into the vaporization chamber in order to introduce a liquid into the vaporization chamber, and the vaporization chamber includes a vapor outlet.

Claims

1. A device for inspecting a surface of an object, in particular a reflective or transparent surface, comprising: an illumination apparatus with which the surface can be illuminated; a measuring apparatus which senses light reflected at the surface; and a vapor-application apparatus which is designed to apply vapor to the surface, wherein the vapor-application apparatus comprises a nozzle, a vaporization chamber having an enclosure, and a heating apparatus, wherein the nozzle protrudes into the vaporization chamber in order to introduce a liquid into the vaporization chamber, and wherein the vaporization chamber comprises a vapor outlet.

2. The device according to claim 1, wherein the illumination apparatus supplies a light beam that can be adjusted for measurement.

3. The device according to claim 1, wherein the heating apparatus is positioned to heat the enclosure.

4. The device according to claim 1, wherein the heating apparatus comprises at least one tubular and/or cylindrical heating element.

5. The device according to claim 1, wherein the nozzle comprises at least one spray outlet that is arranged essentially perpendicularly to the longitudinal axis of the nozzle.

6. The device according to claim 1, wherein the nozzle and the vapor outlet are arranged on opposite sides of the vaporization chamber.

7. The device according to claim 1, wherein the vaporization chamber is embodied to be cylindrical, and wherein the nozzle is arranged on a bottom surface and the vapor outlet is arranged on a top surface.

8. The device according to claim 1, wherein the vapor outlet comprises a baffle.

9. The device according to claim 1, wherein the nozzle is in fluid connection with multiple feed lines, in particular with a liquid feed line, a spray air feed line, and/or a control air feed line.

10. The device according to claim 9, wherein the feed lines each comprise a dispenser.

11. A use of a device according to claim 1 for inspecting vehicle parts.

12. A method for inspecting a surface of an object, in particular a reflective or transparent surface, preferably using a device according to claim 1, the method comprising: the surface is illuminated; a light reflected at the surface is sensed with a measuring apparatus, and vapor is applied to the surface by a vapor-application apparatus in order to produce a layer of liquid droplets on the surface, wherein a liquid is introduced into a vaporization chamber having an enclosure, and wherein the enclosure is heated and the liquid is sprayed onto an inner wall of the enclosure, whereupon the liquid vaporizes and a vapor is conducted out of the vaporization chamber via a vapor outlet and is condensed on the surface of the object.

13. The method according to claim 12, wherein vapor is applied to a region having a diameter of at least 50 mm, in particular of 70 mm to 80 mm, on the surface of the object.

14. The method according to claim 12, wherein a spray air and/or the liquid are introduced into the vaporization chamber and wherein the spray air is optionally introduced first for at least 25 ms, preferably for approximately 50 ms, after which the liquid is admixed for approximately 100 ms to 200 ms.

15. The method according to claim 12, wherein parameters of the vapor-application apparatus are regulated as a function of quality criteria determined from acquired measurement data.

16. The method according to claim 12, wherein additional data, in particular climatic data such as temperature, humidity and the like, for example, are measured in order to correct parameters of the vapor-application apparatus where necessary.

Description

[0032] Additional features, advantages, and effects follow from the exemplary embodiments described below. In the drawings which are thereby referenced:

[0033] FIG. 1 shows a schematic illustration of a device according to the invention;

[0034] FIG. 2 shows a cross-sectional illustration of a vapor-application apparatus.

[0035] FIG. 1 shows a schematic illustration of a device 1 according to the invention and a surface 2 of an object 3 that is to be inspected. The device 1 essentially comprises an illumination apparatus 4, a measuring apparatus 5, and a vapor-application apparatus 6. The illumination apparatus 4, the measuring apparatus 5, and the vapor-application apparatus 6 can, for example, be arranged on a shared base or can be connected to one another in any desired manner. The device 1 preferably comprises a robotic arm on which components of the device 1 are mounted. The arrangement shown in FIG. 1 is to be considered exemplary, since essentially any desired arrangement of individual components is possible. Expediently, the components are arranged such that, starting from the illumination apparatus 4, an incident light beam 7 is directed towards the object 3, which light beam 7 is reflected at the surface 2. A reflected light beam 7 is then sensed by the measuring apparatus 5. As is evident from FIG. 1, the incident light beam 7 is aligned such that it strikes the surface 2 of the object 3 in a region to which vapor is applied. Furthermore, a vapor 8 is illustrated which exits from the vapor-application apparatus 6 and is applied to a defined region on the surface 2 of the object 3.

[0036] In FIG. 2, a vapor-application apparatus 6 is illustrated which comprises a nozzle 9, a vaporization chamber 10, and a heating apparatus 11. The vaporization chamber 10 essentially comprises an enclosure 12, wherein an interior space of the vaporization chamber 10 is laterally bounded by one or more inner walls. Preferably, the vaporization chamber 10 and/or the enclosure 12 are embodied to be cylindrical, wherein the inner wall 13 corresponds to an inner envelope surface.

[0037] As is shown in FIG. 2, the nozzle 9 can be arranged such that it protrudes into the vaporization chamber 10 or into the interior space, in particular in the region of a top surface. In addition, the heating apparatus 11 is positioned such that the inner wall 13 is arranged between the heating apparatus 11 and the interior space. The heating apparatus 11 can, for example, comprise an electric heating element which comprises an electrical connection 14. In the embodiment illustrated, the heating apparatus 11 is embodied with a heating element that runs around the interior space of the vaporization chamber 10. The heating element is normally embodied to be tubular for this purpose. For a supply of fluid, the nozzle 9 comprises multiple, in particular three, feed lines 15, wherein one liquid feed line, one spray air feed line, and one control air feed line are normally provided.

[0038] In addition, in the region of a bottom surface, a vapor outlet 16 is typically provided which is normally embodied as an opening in the enclosure 12. Alternatively, an opening is provided in the bottom surface, into which opening an insert having a central channel can be inserted. Thus, a diameter of the vapor outlet 16 can be modified by means of different inserts. In the embodiment illustrated in FIG. 2, however, the vapor outlet 16 is embodied in one piece with the enclosure 12. At an inner end of the vapor outlet 16, a baffle 17 is provided in which a condensed liquid can collect when the vapor-application apparatus 6 is arranged with the vapor outlet 16 oriented downwards as shown in FIG. 2.

[0039] To apply vapor to a surface 2, a spray air is first introduced into the nozzle 9 through the spray air feed line and subsequently introduced into the vaporization chamber 10. After this, a liquid such as water or ethanol, for example, is admixed through the liquid feed line and is likewise introduced into the vaporization chamber 10 through the nozzle 9. It has proven effective if the spray air is in this case introduced for at least 25 ms, preferably for approximately 50 ms. Here, the liquid is typically atomized and sprayed into the interior space of the vaporization chamber 10 radially at a defined spray angle 18. The spray angle 18 is advantageously set such that the liquid or fine liquid droplets are applied to the inner wall 13 over a wide area. The liquid droplets are vaporized as soon as they strike the inner wall 13, which is heated by the heating apparatus 11. The vapor 8 produced then flows out of the vaporization chamber 10 through the vapor outlet 16. Here, the vapor-application apparatus 6 is preferably arranged such that the vapor 8 is immediately applied to the surface 2 of the object 3 through the vapor outlet 16 and a coat of liquid droplets can thus be applied.

[0040] To enable an efficient inspection of a surface 2, the spray air is typically introduced first into the vaporization chamber 10. In a further step, the liquid is admixed with the spray air in the nozzle 9 and is likewise introduced into the vaporization chamber 10. The liquid is sprayed out radially via the spray outlet or spray outlets of the nozzle 9. A plurality of liquid droplets is thereby applied to the inner wall 13 of the vaporization chamber 10. For this purpose, the nozzle 9 comprises multiple spray outlets that are arranged in a radially circumferential manner, or comprises one radially circumferential spray outlet. In addition, the inner wall 13 of the vaporization chamber 10 is heated by means of the heating apparatus 11 so that the liquid droplets vaporize essentially immediately upon impact with the inner wall 13. The vapor 8 thus obtained is conducted out of the vaporization chamber 10 through the vapor outlet 16 and essentially directly onto the surface 2 of the object 3 in order to be applied thereto.

[0041] Thus, during the application of vapor to the surface 2, the vapor 8 is conducted onto the surface 2, where it condenses and forms the coat of liquid droplets. As a result, the surface 2, in particular a transparent or reflective surface 2, becomes cloudy, whereby reflected light can be sensed by the measuring apparatus 5, which ultimately enables the efficient inspection of the surface 2 with regard to a profile measurement as well as defects such as scratches, for example.