Device for spraying the inner wall of a cavity

Abstract

The invention relates to a device for spraying an inner wall of a cavity, comprising a suction spray head (3) to which an inlet line (11) for supplying a spray material (17) to the suction spray head (3) for atomization in the cavity (15) and an extraction line (13) for removing excess spray material (17) from the cavity (15) are connected, wherein a spray nozzle (5) of the suction spray head (3) has at least one opening (23) for the exit of the spray material (17). In a device which improves the efficiency of the spraying process, the spray nozzle (5) comprises a spray channel (19) open at both ends, which runs at an angle to the injection line (11) and / or suction line (13), wherein a hollow cylindrical element (21) extends transversely to its longitudinal extent within the spray channel (19), on the circumference of which the opening (23) for the exit of the spray material (17) is formed.

Description

[0001] The invention relates to a device for spraying an inner wall of a cavity, comprising a suction spray head to which an injection line for introducing a spray material into the suction spray head for atomization in the cavity and a suction line for removing excess spray material from the cavity are connected, wherein a spray nozzle of the suction spray head has at least one opening for the outlet of the spray material.

[0002] EP 0 744 218 B1 discloses a device for the internal coating of container bodies, in which a spray / suction head is arranged in a chamber. The spray nozzle of the spray / suction head is connected to a suction line, and the suction nozzle of the spray / suction head is connected to a suction line. The suction and suction lines can be designed in a coaxial, ring-shaped configuration. A suction element surrounds a spray element or projects beyond it in the axial direction. The coating material discharged by the spray element is discharged in the axial direction of the chamber and the suction and suction lines.

[0003] The object of the invention is to provide a device for spraying an inner wall of a cavity which improves the efficiency of the spraying process.

[0004] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims. Further features, possible applications, and advantages of the invention will become apparent from the following description and the explanation of exemplary embodiments of the invention illustrated in the figures.

[0005] The problem is solved by the subject matter of patent claim 1.

[0006] In the device explained above for spraying an inner wall of a cavity, comprising a suction spray head to which an injection line for introducing a spray material into the suction spray head for atomization in the cavity and a suction line for removing excess spray material from the cavity are connected, wherein a spray nozzle of the suction spray head has at least one opening for the outlet of the spray material, the spray nozzle comprises a spray channel that is open on both sides and runs at an angle to the injection line and / or suction line, wherein a hollow cylindrical element extends within the spray channel transversely to its longitudinal extent, on the circumference of which the at least one opening for the outlet of the spray material is arranged. This has the advantage that when the device moves within the cavity, a radial radiation of the coating material occurs simultaneously in several directions.This allows for significantly faster coating of the cavity, improving the efficiency of the spraying process. Furthermore, when the cross-section of the cavities to be coated changes, as is often the case in automobiles, the material consumption of the spraying process can be adjusted for each direction, resulting in more differentiated material usage. This increases occupational safety and environmental friendliness.

[0007] Advantageously, several openings encircle the circumference of the hollow cylindrical element in a helical shape and are connected to the injection line. This allows for a uniform material application.

[0008] In one embodiment, a passage for conveying the extracted spray material is guided through the hollow cylindrical element, with an indentation connected to the injection line for conveying the injected spray material being partially coaxially encompassed by the passage for conveying the extracted spray material. This design allows for a geometric reduction in the size of the suction-spray head, thereby expanding its field of application, particularly for smaller cavities.

[0009] In one variant, the hollow-cylindrical element is mounted for rotational movement. This design is particularly advantageous when the spray nozzle has only a single bore. The rotation of the hollow-cylindrical element ensures optimal distribution of the coating material within the cavity. The rotational movement can be captured either by recoil of the escaping spray material or by the energy of the exhaust air, for example, via paddle wheels.

[0010] In one embodiment, a suction nozzle of the suction-spray head has at least one suction channel extending parallel to the spray channel and open on both sides. Inside the suction channel, a suction element is positioned. The suction element consists of two circular, spaced-apart plates that extend axially along the suction channel and are mechanically connected to one another transversely to the suction channel. Since the open sides extend in the same direction as the open ends of the spray channel, reliable removal of excess spray material from the cavity is ensured at all times. The use of several such suction channels for removing the unused spray material enables the injection of a more highly enriched mixture of the spray material by the injection air, which can in particular be returned to a container for reuse.

[0011] It is advantageous if the mechanical connection is designed to vary the distance between the two plates. The strength of the suction of the spray material can be adjusted by adjusting the distance, as this regulates the air velocity. The distance can be adjusted, for example, using threaded rods. The closer the distance between the two plates, the higher the air velocity while maintaining a constant amount of extracted air, and the stronger the local suction effect.

[0012] In a further embodiment, one of the circular plates has a through-hole through which the sucked-in excess spray material is discharged. This allows for a simple design of the spray-suction head.

[0013] In another variant, a tube-like element is inserted through the through-hole to convey the injected spray material. This enables a particularly compact and space-saving spray-suction head.

[0014] In a further embodiment, an air guide element is formed in the spray channel of the spray nozzle to modify the air flow through it. Such an air guide element can, for example, generate a circular air flow that promotes material distribution.

[0015] It is also advantageous if the injection line and the suction line are arranged coaxially with each other, and the spray channel of the spray nozzle and the suction channel of the suction nozzle run at right angles to the coaxial injection and suction lines. This enables a particularly compact design of the spray-suction head.

[0016] Further advantages, features, and details will become apparent from the following description, in which at least one exemplary embodiment is described in detail—possibly with reference to the drawings. Described and / or illustrated features may form the subject matter of the invention alone or in any meaningful combination, possibly independently of the claims, and may, in particular, also be the subject of one or more separate applications. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0017] They show: Fig. 1 an embodiment of the device according to the invention, Fig. 2 a longitudinal section through the device according to the invention according to Fig. 1, Fig. 3 a section through the suction nozzles, Fig. 4 a section through a hollow cylindrical element of the spray nozzle.

[0018] In Fig. 1 shows an embodiment of the device according to the invention. The device is designed as a spray probe with a material return line, which is used for coating cavities, for example in automotive construction. The device 1 comprises a spray-suction head 3, which consists of a centrally arranged spray nozzle 5, on which a suction nozzle 7, 9 is arranged on each side. The spray nozzle 5 is connected to an injection line 11, while the two suction nozzles 7, 9 are coupled to a suction line 13. The injection line 11 is coaxially surrounded by the suction line 13. The spray-suction head 3, which can be moved within the cavity 15, is designed such that the material 17 discharged by the spray nozzle 5 with the injection air 41 to coat the cavity 15 is discharged in a radial direction and is also taken up again from this direction by the suction nozzles 7, 9.

[0019] A longitudinal section through the device according to the invention according to Fig. 1 is in Fig. 2. The spray nozzle 5 consists of a spray channel 19, which extends perpendicular to the longitudinal extent of the injection line 11 and the suction line 13. A hollow cylindrical element 21, which forms the actual spray element, is arranged approximately centrally within the spray channel 19. Continuous helical slots 23 extend along the circumference of the hollow cylindrical element 21 for the radial discharge of the spray material 17 into the spray channel 19, which is open on both sides and thus allows the injection air 41 containing the spray material 17 to exit into the cavity 15. The spray material 17 is supplied by connecting the injection line 11 to the casing of the hollow cylindrical element 21.

[0020] The suction nozzles 7, 9 each comprise a suction channel 25, which extends parallel to the spray channel 19 of the spray nozzle 5. Each suction nozzle 7, 9 consists of two circular plates 27, 29, which extend axially on the inside of the suction channel 25. The plates 27, 29 are mechanically held together by at least one pin 31 or one screw. The pin 31 or the screw is located at the level of the hollow cylindrical spray element 21 and also engages with it. This connects the suction channels 25 to the spray channel 19 and forms a structural unit. The distance between the two plates 27, 29 can be variably adjusted via the pin 31 or the screw, thereby influencing the strength of the suction of the spray material 17.

[0021] A section AA through the suction nozzles 5, 7 is shown in Fig. 3. This shows Fig. 3a shows the section AA through the first suction nozzle 7, while Fig. 3b shows the section AA through the second suction nozzle 9. In the suction channel 25, there is a channel-shaped opening 33 transverse to it for transporting the suction air 43 into the suction line 13. The channel-shaped opening 33 is surrounded by several pins 31 or screws. Fig. 3b, section AA of the suction nozzle 9 additionally shows an injection air pipe 35, which is guided through the channel-shaped opening 33 in order to guide the injection air 41 and the spray material 17 to the hollow cylindrical element 21 of the spray nozzle 3

[0022] In Fig.4 shows a section BB through the hollow cylindrical element 21. On the circumference of the hollow cylindrical element 21, the helical slots 23 are indicated, which pierce the wall of the hollow cylindrical element 21. A passage 37 for the suction air 43 extends centrally. The round cross-section of the passage 37 is interrupted by an inwardly directed recess 39, which is closed off from the passage 37 and serves as the inlet for the blow-in air 41 and the spray material 17 into the hollow cylindrical element 21. The recess 39, which also forms a channel, is open opposite the slots 23. The pins 31 or screws for fastening the suction nozzles 7, 9 to the spray nozzle 3 engage around the passage 37 and the recess 39.

[0023] To adjust the air circulation in the spray line 19 and / or the suction line 25, it is possible to insert air guide elements 45 into them. If it is desired to pull the device 1 over a floor of the cavity 15, increased suction at the floor can be achieved by adapting the shape accordingly and inserting the air guide elements 45 into the suction channel 25.

[0024] The spray material 17 recovered with the extraction air 43 can be removed from the extraction air 43 by connecting the extraction line 13 to a cyclone separator. After suitable pre-filtration, the spray material 17 can be returned via a multi-chamber system in a material intake cup of the device 1. This multi-chamber system can, for example, consist of two chambers on a pressure cup gun, which are alternately connected to the cyclone separator and then receive its material via gravity. The two chambers can also be connected under pressure to a suction cup, whereby the recovered spray material 17 flows into the suction cup under the influence of gravity. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] EP 0 744 218 B1

[0002]

Claims

[1] Device for spraying an inner wall of a cavity, comprising a suction spray head (3), to which an injection line (11) for introducing a spray material (17) into the suction spray head (3) for atomization in the cavity (15) and a suction line (13) for removing excess spray material (17) from the cavity (15) are connected, wherein a spray nozzle (5) of the suction spray head (3) has at least one opening (23) for the outlet of the spray material (17), characterized by in that the spray nozzle (5) comprises a spray channel (19) which is open on both sides and runs at an angle to the injection line (11) and / or suction line (13), wherein a hollow cylindrical element (21) extends within the spray channel (19) transversely to its longitudinal extent, on the circumference of which the opening (23) for the outlet of the spray material (17) is formed. [2] Device according to claim 1, characterized bythat several openings (23) helically encircle the circumference of the hollow cylindrical element (21) and are connected to the injection line (11). [3] Device according to claim 2, characterized by that a passage (37) for conveying the extracted spray material (17) is guided through the hollow cylindrical element (21), wherein an upwardly open indentation (39) connected to the injection line (11) for conveying the injected spray material (17) is partially coaxially encompassed by the passage (37) for conveying the extracted spray material (17). [4] Device according to claim 2 or 3, characterized by that the hollow cylindrical element (21) is rotatably mounted to carry out a rotational movement. [5] Device according to at least one of the preceding claims, characterized bythat a suction nozzle (7, 9) of the suction-spray head (3) has at least one suction channel (25) extending parallel to the spray channel (19), in the interior of which a suction element is positioned which consists of two circular, spaced-apart plates (27, 29) which extend axially to the suction channel (25) and are mechanically connected to one another. [6] Device according to claim 5, characterized by that the mechanical connection (31) is designed to vary the distance between the two plates (27, 29). [7] Device according to claim 5 or 6, characterized by that one of the circular plates (27, 29) has a through-opening (33) through which the sucked-in excess spray material (17) is discharged. [8] Device according to claim 5, 6 or 7, characterized by that a tube-like element for conveying the blown-in spray material (17) is guided through the through-opening (33). [9] Device according to at least one of the preceding claims, characterized by that an air guiding element (45) is formed in the spray channel (19) of the spray nozzle (5) for changing the air flow guided through it. [10] Device according to at least one of the preceding claims, characterized by that the injection line (11) and the suction line (13) are arranged coaxially to one another and the spray channel (19) of the spray nozzle (5) and the suction channel (25) of the suction nozzle (7, 9) run at a right angle to the coaxial injection and suction line (11, 13).

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