spray nozzle

Abstract

The invention relates to a spray nozzle (10, 100, 200, 300) for applying a coating, in particular for cavity preservation of a cavity of a car body or vehicle, with a nozzle body (12) and at least one medium connection (16, 18, 316) and at least one medium channel (26, 324, 326) inside the nozzle body (12) leading from the at least one medium connection (16, 18, 316) to an outlet opening (22, 30, 322), wherein at least two medium channels (24, 26, 324, 326) are arranged inside the nozzle body (12).

Description

[0001] The invention relates to a spray nozzle for applying a coating, in particular for cavity preservation of a cavity in a car body or vehicle, comprising a nozzle body and at least one medium connection, as well as a medium channel inside the nozzle body leading from the at least one medium connection to an outlet opening. The invention further relates to a method for applying a coating, in particular for cavity preservation of a cavity in a car body or vehicle, in which a coating material is applied by means of a spray nozzle.

[0002] Motor vehicles contain numerous cavities that are susceptible to corrosion. To reduce the risk of corrosion, it is common practice to coat the surfaces of these susceptible cavities, for example with wax. This is usually done using spray nozzles through which the coating medium can be applied.

[0003] From DE 30 04 495 A1, for example, an arrangement for the internal coating of cavities has become known, which has a control system for controlling several spray nozzles that serve for cavity preservation.

[0004] DE 10 2004 046 351 A1 discloses a method for the automatic preservation of cavities in a motor vehicle using a spray system, wherein a spray nozzle is inserted into a cavity to be preserved and wax is sprayed onto the inner walls of the cavity through the spray nozzle. The spray nozzle described therein has a multi-part construction and comprises a nozzle base, a nozzle tube, a nozzle body and a nozzle head.

[0005] A spray nozzle is also known from DE 25 26 702 A1. The spray nozzle consists of a tube closed at the end with slots, the planes of which form different angles with the tube axis.

[0006] WO 2012 / 022477 A1 describes a spray nozzle comprising two coaxially arranged tubes. By rotating one tube relative to the other, the outlet openings can be switched on or off. A seal is located between the tubes.

[0007] All known spray nozzles have in common that they only have one medium channel. A coating material, usually a mixture of wax and air, is fed into this medium channel.

[0008] It has been shown that consistently high coating quality and reproducibility cannot always be guaranteed with such spray nozzles. It is suspected that the coating material, which consists of a mixture of wax and air, deposits itself in sections within the medium channel, leading to these problems.

[0009] The object of the present invention is therefore to provide a spray nozzle with which the coating of surfaces, in particular of surfaces of cavities, can be carried out more reliably.

[0010] This problem is solved according to the invention by a spray nozzle for applying a coating, in particular for cavity preservation of a cavity in a car body or vehicle, comprising a nozzle body and at least one medium connection, as well as at least one medium channel inside the nozzle body leading from the at least one medium connection to an outlet opening, wherein at least two medium channels are arranged inside the nozzle body. If at least two medium channels are provided, one medium channel can be used for a first medium, for example wax, and a second medium channel for a second medium, for example air. Coating material to be sprayed from the nozzle can thus be supplied in separate medium channels, and the media can only be combined immediately before exiting the nozzle to create a coating mixture.Alternatively, it is possible to implement smaller diameter media channels that lead directly to an outlet. Both of these measures can achieve higher coating quality, better reproducibility, and less contamination outside the spray nozzle.

[0011] It is particularly advantageous if the spray nozzle, at least partially, especially the part containing the medium channel(s), is manufactured using a 3D printing process. The entire spray nozzle can also be manufactured using a 3D printing process. Multiple medium channels can be created particularly easily and effectively using 3D printing. Furthermore, the relative positions of the medium channels can be precisely defined. Outlet openings can also be manufactured more accurately using 3D printing than, for example, by drilling, as was previously the standard practice. In particular, larger angles of the outlet openings relative to the normal to the nozzle body surface can be achieved, allowing for better adaptation of the spray nozzle to the specific coating task.

[0012] Further advantages arise if the spray nozzle, at least except for one holder, is manufactured as a single piece. This prevents different components of the spray nozzle from shifting relative to each other and avoids the development of tolerances between different parts. Leaks at transitions between different parts of a spray nozzle can also be avoided if the spray nozzle is manufactured as a single piece, at least predominantly. A holder can be manufactured as a separate part and connected to the rest of the spray nozzle, for example, by soldering or welding. At least the rest of the spray nozzle can be manufactured as a single piece. However, it is also conceivable that the entire spray nozzle, including the holder, is manufactured as a single piece.

[0013] The spray nozzle can be made of plastic and / or metal. For example, the holder can be made of metal and the rest of the spray nozzle of plastic, or vice versa. These materials make it particularly well-suited for 3D printing of a spray nozzle, especially the part containing the medium channel(s). High pressure resistance and dimensional stability can be achieved if the spray nozzle is made at least partially, and preferably entirely, of metal.

[0014] Larger application areas than previously possible can be developed if the outlet opening, which in particular has an elliptical cross-section, has an angle in the range of 30° to 89°, preferably in the range of 50° to 89°, and especially preferably in the range of 60° to 89°, to the normal of the nozzle body surface. This measure makes it possible to solve coating problems that were previously unsolvable.

[0015] At least one outlet opening can be arranged on an end face of the nozzle body. Alternatively or additionally, at least one outlet opening can be provided on a circumference of the nozzle body. The outlet opening on an end face allows coating material to be sprayed axially, while outlet openings along the circumference of the nozzle body allow, for example, radial spraying of the coating material.

[0016] At least one of the medium channels can have an inner diameter in the range of 0.5 mm to 3 mm. It is possible to transport a medium at high pressure in such a medium channel. A spray nozzle, particularly a nozzle body, can have several medium channels, each leading to an outlet opening, especially if the medium channels have an inner diameter in the range of 0.5 mm to 1.5 mm.

[0017] If multiple medium channels are connected to the first medium connection, several medium channels can be supplied by that single medium connection. In particular, a mixture of air and wax can be supplied to the medium channels via the first medium connection.

[0018] According to one embodiment of the invention, a second medium connection can be provided, and at least one medium channel can be connected to the first medium connection and at least one medium channel to the second medium connection. Thus, two medium channels can be supplied with different media. For example, wax and air can be supplied to the spray nozzle via different medium connections, and then mixed together within the spray nozzle.

[0019] A first and a second medium channel can be arranged coaxially, with one of the medium channels having a transfer opening into the other medium channel. The different media can be mixed in the area of ​​the transfer opening and then exit the spray nozzle via an outlet opening. It can be advantageous if the transfer opening and the outlet opening are arranged opposite each other.

[0020] To achieve the most complete and even coating possible, it can be advantageous to have multiple inlet and outlet openings. This allows the coating material to exit the spray nozzle through several openings.

[0021] It is possible to arrange multiple outlet openings offset in the axial direction. Alternatively or additionally, multiple outlet openings can be offset in the circumferential direction. This allows for considerable design freedom in the configuration of the spray nozzle, enabling the arrangement of outlet openings to be selected appropriately depending on the coating task.

[0022] The invention also encompasses a method for applying a coating, particularly for cavity preservation of a cavity in a car body or vehicle, in which a coating material is applied by means of a spray nozzle. Two media at different pressures are supplied to the spray nozzle, and the media are mixed within the spray nozzle to form the coating material before the coating material exits the spray nozzle through an outlet opening. This allows the two media to be guided largely separately within the spray nozzle. As a result, contamination and deposits of coating material within the spray nozzle can be avoided. In particular, the media can be guided in separate channels within the spray nozzle.

[0023] One medium, in particular wax, can be transferred from one medium channel through a transfer opening into another medium channel and mixed there with the other medium, in particular air. The mixture can then be sprayed through the outlet of the spray nozzle. The media can be supplied to the spray nozzle at different pressures. One medium, for example wax, can be introduced at a pressure of more than 5 bar, while the other medium, in particular air, can be introduced at a pressure of more than 1 bar, particularly in the range of 1 bar to 5 bar. If the pressure of the wax medium is higher than the pressure of the air medium, it can be prevented from entering the medium channel containing the wax. The higher-pressure medium can be contained in an inner medium channel surrounded by the other medium channel.

[0024] Further features and advantages of the invention will become apparent from the following detailed description of the embodiments of the invention, with reference to the figures of the drawing which show details essential to the invention, as well as from the claims.

[0025] The features shown in the drawing are presented in such a way as to clearly illustrate the special features of the invention. The various features can be implemented individually or in any combination in variants of the invention.

[0026] They show: Fig. 1 a perspective view of a first embodiment of a spray nozzle; Fig. 2 a longitudinal section view through the spray nozzle of the Fig. 1; Fig. 3 a perspective view of an alternative design of a spray nozzle; Fig. 4 a sectional view of the spray nozzle of the Fig. 3; Fig. 5 another embodiment of a spray nozzle in perspective view; Fig. 6 a longitudinal section view of the spray nozzle of the Fig. 5; Fig. 7 a longitudinal section view of another spray nozzle.

[0027] Fig. Figure 1 shows a spray nozzle 10 with a nozzle body 12, which is essentially cylindrical. A holder 14 is arranged on the nozzle body 12, via which the spray nozzle 10 can be coupled to a coating system, in particular a robot of a coating system. The spray nozzle 10 can be positioned appropriately on or in a car body by means of such a robot to perform a coating task. The spray nozzle 10 has a first medium connection 16, through which a first medium can be supplied to the spray nozzle 10. Furthermore, a second medium connection 18 is provided, through which a second medium can be supplied to the spray nozzle 10. In the illustrated embodiment, the second medium connection 18 is oriented perpendicular to the longitudinal direction of the nozzle body 12. The first medium connection 16 is located at one end of the nozzle body 12. At the opposite end 20, the nozzle body 12 is closed at the end face.The coating material can exit the nozzle body 12 through outlet openings 22. In the illustrated embodiment, the outlet openings 22 are arranged axially offset.

[0028] The spray nozzle 10 can be manufactured using a 3D printing process. In particular, the spray nozzle 10 can be manufactured as a single piece. It can be made of metal or plastic.

[0029] The Fig. Figure 2 shows a cross-sectional view through the spray nozzle 10 of the Fig. 1. Elements already described receive the same reference numbers as in the Fig. 1. In the Fig. Figure 2 shows that the first medium connection 16 is connected to a first medium channel 24. The first medium channel 24 extends parallel to the longitudinal direction of the spray nozzle 10 and is located inside the nozzle body 12. The medium channel 24 is located centrally in the spray nozzle 10 or in the nozzle body 12. A wax, for example, can be supplied to the medium channel 24 as a preservative via the first medium connection 16.

[0030] The second medium connection 18 is connected to a second medium channel 26. The medium channel 26 is arranged concentrically to the first medium channel 24 and also runs inside the nozzle body 12. Air, for example, can be supplied to the medium channel 26. A medium at a higher pressure than the medium channel 26 can be supplied to the medium channel 24. To allow the medium from the first medium channel 24 to mix with the medium in the second medium channel 26, a transfer opening 28 is provided, connecting the first medium channel 24 to the second medium channel 26. The transfer opening 28 is located in the area of ​​the outlet openings 22. The medium from the first medium channel 24 can thus pass through the transfer opening 28 into the second medium channel 26, where the two media mix to form a coating material. The coating material can then exit the spray nozzle 10 through the outlet openings 22.

[0031] In the Fig. 2 another outlet opening 30 can be seen, which is located in the Fig. 1 is not visible. The outlet opening 30 is arranged axially and circumferentially offset with respect to the outlet openings 22.

[0032] The diameter of the first medium channel 24 can range from 0.5 mm to 3 mm. The distance between the wall 32 of the nozzle body 12 and the wall 34 of the first medium channel 24 can correspond to the diameter of the first medium channel 24. It is also conceivable that the distance is larger or smaller than the diameter of the medium channel 24.

[0033] The design of the spray nozzle 100 according to the Fig. 3 essentially corresponds to the design of the spray nozzle of the Fig. 1, with the difference that the first and second medium connections 16, 18 are arranged at one end of the nozzle body 12. This is shown in particular by the illustration of the Fig. Figure 4 clearly shows that the first medium channel 24 and the second medium channel 26 are arranged coaxially to each other over the entire length of the nozzle body 12. In order to supply two media separately to these two medium channels 24 and 26, a medium connection piece, which is not shown and is plugged onto the media connections 16 and 18, must be designed accordingly.

[0034] The design of the spray nozzle 200 according to the Fig. 5 differs from the spray nozzle 100 of the Fig. 3 by the design of the first and second medium connections 16, 18. This is again shown by the sectional view of the Fig. 6 clearly. It can be seen that at the end of the nozzle body 12 opposite end 20, the first medium connection 16 projects axially beyond the second medium connection 18. This makes it particularly easy to ensure that the media can be supplied separately to the medium channels 24, 26 and that prior mixing of the two media is prevented. Here, too, the first and second medium channels 24, 26 extend coaxially in the nozzle body 12, in particular up to the first and second medium connections 16, 18. Due to the coaxial arrangement of the medium connections 16, 18, the designs of the spray nozzles 100, 200 of the Fig. 3 to Fig. 5. Easier to implement in existing and currently used coating processes. The spray nozzle according to Fig. 1 and Fig. 2 is not readily usable in an automated robot process.

[0035] The Fig.Figure 7 shows a sectional view of another spray nozzle 300. As in the previous embodiments, medium channels 324, 326 are arranged inside the nozzle body 12. As in the previous embodiments, the medium channels 324, 326 run parallel to each other in one section. They also run parallel to the longitudinal direction of the spray nozzle 300, at least in one section.

[0036] Unlike the previous embodiments, only one medium connection 316 is provided, through which a medium can be supplied to the spray nozzle 300. In this case, a coating material is supplied to the spray nozzle 300, i.e., a material that is a mixture of several media, for example, wax and air. The medium channels 324 and 326 branch out from the medium connection 316. The medium channels 324 and 326 are completely separated from each other from the point of branching. There are also no transfer openings. The medium channels 324 and 326 each lead to an outlet opening 322. Additional outlet openings can also be arranged axially or radially offset from the opening 322 shown. While not shown, it is conceivable to provide an outlet opening 322 on the end face 320. This also applies to the previous embodiments. The spray nozzle 300 can also be manufactured using a 3D printing process.It can be made of metal or plastic. The spray nozzle 300 also has a holder 14.

[0037] The outlet opening 322 shows that the outlet openings can be oriented at an angle to the normal 340 on the surface 342 of the nozzle body 12. The angle α to the normal 340 on the nozzle body surface 342 can be 0° or in the range of 0° to 89°. Advantageously, the angle can be greater than 30°, preferably in the range of 30° to 89°. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 30 04 495 A1

[0003] DE 10 2004 046 351 A1

[0004] DE 25 26 702 A1

[0005] WO 2012 / 022477 A1

[0006]

Claims

[1] Spray nozzle (10, 100, 200, 300) for applying a coating, in particular for cavity preservation of a cavity of a body or vehicle, with a nozzle body (12) and at least one medium connection (16, 18, 316) and at least one medium channel (26, 324, 326) inside the nozzle body (12) leading from the at least one medium connection (16, 18, 316) to an outlet opening (22, 30, 322), characterized by , that at least two medium channels (24, 26, 324, 326) are arranged inside the nozzle body (12). [2] Spray nozzle according to claim 1, characterized by , that the spray nozzle (10, 100, 200, 300) is at least partially manufactured, in particular the part of the spray nozzle which has the medium channel(s), using a 3D printing process. [3] Spray nozzle according to one of the preceding claims, characterized by that it is formed in one piece, at least except for one holder (14). [4] Spray nozzle according to any one of the preceding claims, characterized by , that the spray nozzle (10, 100, 200, 300) is made of plastic and / or metal. [5] Spray nozzle according to any one of the preceding claims, characterized by , that the outlet opening (22, 30, 322) having in particular an elliptical cross-section has an angle in the range of 30° to 89°, preferably in the range of 50° to 89°, particularly preferably in the range of 60° to 89°, to the normal (340) of the nozzle body surface (342). [6] Spray nozzle according to any one of the preceding claims, characterized by , that at least one outlet opening (22, 30, 322) is arranged on an end face (320) of the nozzle body (12). [7] Spray nozzle according to one of the preceding claims, characterized by , that at least one of the medium channels (24, 324, 326) has an inner diameter in the range of 0.5 mm to 3 mm. [8] Spray nozzle according to one of the preceding claims, characterized by, that several medium channels (324, 326) are connected to the first medium port (316). [9] Spray nozzle according to any one of the preceding claims, characterized by , that a second medium connection (18) is provided and at least one medium channel (24, 324) is connected to the first medium connection (16, 316) and at least one medium channel (26) is connected to the second medium connection (18). [10] Spray nozzle according to any one of the preceding claims, characterized by , that a first and a second medium channel (24, 26) are arranged coaxially, wherein one of the medium channels (24) has a transition opening (28) opening into the other medium channel (26). [11] Spray nozzle according to claim 10, characterized by , that the entry opening (28) and the exit opening (22, 30) are arranged opposite each other. [12] Spray nozzle according to claim 10 or 11, characterized by , that several entry and exit openings (28, 22, 30) are provided. [13] Spray nozzle according to one of the preceding claims, characterized by , that several outlet openings (22, 30) are provided offset in the axial direction. [14] Spray nozzle according to any one of the preceding claims, characterized by , that several outlet openings (22, 30) are provided offset in the circumferential direction. [15] Method for applying a coating, in particular for cavity preservation of a cavity of a body or vehicle, in which a coating material is applied by means of a spray nozzle (10, 100, 200, 300), characterized by , that two media with different pressures are supplied to the spray nozzle (10, 100, 200, 300) and the media are mixed within the spray nozzle (10, 100, 200, 300) to form the coating material before the coating material leaves the spray nozzle (10, 100, 200, 300) through an outlet opening (22, 30). [16] Method according to claim 15, characterized by, that the media in the spray nozzle (10, 100, 200, 300) are guided in different medium channels (24, 26). [17] Method according to one of the preceding claims 15 or 16, characterized by , that one medium, in particular wax, is transferred from one medium channel (24) through a transfer opening (28) into the other medium channel (26) and is mixed there with the other medium, in particular air, and the mixture is then sprayed through the outlet opening (22, 30) of the spray nozzle (10, 100, 200).

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