centrifuge

Abstract

Centrifugal apparatus (1) for coating objects, with a centrifugal nozzle, to the front end of which is connected an impact plate (5) which is set into a rotary movement about a rotational axis by means of a drive, wherein a coating material is dispensed via the front end of the centrifugal nozzle and guided against the impact plate (5), wherein the coating material is atomized on the impact plate (5) and deflected in the direction of a surface of an object to be coated, characterized in that the drive is an electric motor (10) which is arranged coaxially to the rotational axis of the impact plate (5) and to the centrifugal nozzle.

Description

[0001] The invention relates to a centrifuge.

[0002] Such a centrifugal coating device is generally used for coating objects. In particular, the centrifugal coating device is used for coating the interior of objects, whereby a coating is applied to the interior walls surrounding a hollow space within the object. The hollow spaces are advantageously designed to be rotationally symmetrical.

[0003] The centrifuge can be used to coat a wide variety of objects, such as workpieces and everyday objects.

[0004] Known centrifugal coating devices comprise a rotating centrifugal nozzle with an impact plate operating at speeds of several thousand revolutions per minute, as well as a nozzle for ejecting a coating material onto the impact plate. When the coating material hits the rotating impact plate, it is propelled radially outward by centrifugal force, breaking it into individual threads or droplets, which are then projected onto the surface of the object to be coated.

[0005] Typically, the centrifugal nozzle is set into rotational movements by means of an electric belt drive.

[0006] A centrifugal device for coating workpieces is known from DE 10 2007 039 974 A1. This centrifugal device comprises a rotatable centrifugal nozzle and a central channel for supplying coating materials. A nozzle is provided at the front end of the channel. The coating material emerging from the nozzle strikes a rotating impact plate, where it is atomized and, under the influence of centrifugal force, moved radially outward. It is then centrifuged at the edge and thus guided against the surface of a workpiece to be coated.

[0007] The invention is based on the object of providing a centrifuge of the type mentioned above, which has a compact design and at the same time a high level of functionality.

[0008] To achieve this object, the features of claim 1 are provided. Advantageous embodiments and expedient developments of the invention are described in the dependent claims.

[0009] The invention relates to a centrifugal device for coating objects. The centrifugal device comprises a centrifugal nozzle, at the front end of which is connected an impact plate, which is driven by a drive to rotate about a rotational axis. A coating material is dispensed via the front end of the centrifugal nozzle and guided against the impact plate. The coating material is atomized by the impact plate and deflected toward the surface of an object to be coated. The drive is an electric motor arranged coaxially to the axis of rotation of the impact plate and the centrifugal nozzle.

[0010] The centrifugal apparatus according to the invention is used generally for coating and in particular for internal coating of objects.

[0011] The centrifuge device works in such a way that a liquid coating material is guided in a centrifuge nozzle and is discharged at the front end and guided against a baffle plate rotating about a rotation axis.

[0012] The coating material is atomized at the impact plate and, due to centrifugal force, is guided outward beyond the impact plate toward the surface of an object to be coated. The surface to be coated is advantageously formed by a rotationally symmetrical inner wall of an object that encloses a cavity.

[0013] According to the invention, the rotary motion is generated by an electric motor arranged coaxially with the axis of rotation of the impact plate and the centrifuge nozzle. This coaxial arrangement results in a particularly compact design of the centrifuge.

[0014] The electric motor is particularly advantageous as it has an electric direct drive.

[0015] Since the electric motor does not require a gearbox, a particularly compact design is achieved. Furthermore, the drive system is cost-effective, as a gearbox is no longer required.

[0016] A further advantage of the drive according to the invention is that it allows for high speeds. The impact plate rotates at correspondingly high speeds, which is an essential prerequisite for a reproducible, uniform coating of the objects.

[0017] The speeds are advantageously in the range of several thousand revolutions per minute, typically up to 60,000 rpm.

[0018] The electric motor is advantageously a brushless DC drive or a permanent synchronous motor.

[0019] Such electric motors are available in small designs with high performance.

[0020] The electric motor is particularly advantageous as it is a hollow shaft motor.

[0021] With such a hollow shaft motor, a particularly compact design of the centrifuge can be realized, since in particular a section of the centrifuge nozzle can be guided in the hollow shaft of the hollow shaft motor.

[0022] According to an advantageous embodiment, the centrifugal nozzle has a paint tube and a nozzle needle guided therein and running coaxially thereto.

[0023] The centrifugal nozzle and the nozzle needle are fixed units, i.e. these units are not set in rotation by the electric motor.

[0024] The paint tube and the nozzle needle, as components of the centrifuge nozzle, are guided in sections in the hollow shaft of the hollow shaft motor, which allows the length of the centrifuge to be kept small.

[0025] The functionality of this centrifugal nozzle is such that the coating material is guided between the nozzle needle and the inner wall of the paint tube.

[0026] There is a needle tip at the front end of the nozzle needle facing the baffle plate.

[0027] The liquid coating material is guided over the needle tip against the impact plate and atomized at its tear-off edge.

[0028] The nozzle needle is advantageously used to regulate the flow of the coating material in the paint tube.

[0029] The flow regulation controls the amount of coating material pumped and thus also the coating process of the object to be coated.

[0030] The flow of the coating material through the paint tube can be adjusted particularly easily by adjusting the distance between the needle tip and the baffle plate.

[0031] It is particularly advantageous for the centrifuge to have a spraying device with a mechanical adjustment mechanism. By operating the adjustment mechanism, the user can precisely adjust the flow of the coating material in the paint tube.

[0032] According to a structurally advantageous embodiment, the paint tube runs in an outer tube which rotates with a rotor of the electric motor.

[0033] Furthermore, the baffle plate is firmly connected to the outer tube.

[0034] The paint tube and the outer tube are arranged coaxially, and the baffle plate is also arranged coaxially to the outer tube.

[0035] Due to the fixed connection to the outer tube, the rotational movement of the electric motor's rotor is transmitted directly via the outer tube to the impact plate. The impact plate is advantageously designed in the shape of a circular disk, with at least one pin extending axially from the impact plate forming a coupling element to the outer tube.

[0036] Advantageously, the outer tube is connected to the electric motor by means of a high-precision clamp connection.

[0037] The high-precision clamp connection ensures a reliable and stable connection of the outer tube to the electric motor.

[0038] The high-precision clamp connection conveniently fulfills an additional function in that it can be used to adjust the distance between the paint tube and the baffle plate.

[0039] In order to ensure that the paint tube is held in a stable position in the outer tube, a bearing can be used at the front end of the outer tube to support the paint tube.

[0040] The invention is explained below with reference to the drawings. They show: Fig. 1: Side view of an embodiment of the centrifuge according to the invention. Fig. 2: Sectional view of the centrifuge according to Fig. 1. Fig. 3: Enlarged partial view of the arrangement according to Fig. 2. Fig. 4: Illustration of individual components of the centrifuge according to the Fig. 1 and Fig. 2.

[0041] The Fig. 1 and Fig. 2 show an embodiment of the centrifuge 1 according to the invention. The centrifuge 1 is generally used for coating, in particular for internal coating of objects.

[0042] The centrifuge device 1 has a paint tube 2 and a nozzle needle 3 to form a centrifuge nozzle.

[0043] How Fig. 2 and the detailed representation of Fig. 3, the nozzle needle 3 runs inside the paint tube 2, with the nozzle needle 3 and the paint tube 2 running coaxially along the common longitudinal axis of both units.

[0044] The paint tube 2 with the nozzle needle 3 is mounted in an outer tube 4, as the Fig. 1 to 3. The outer tube 4, the paint tube 2 and the nozzle needle 3 form a coaxial arrangement.

[0045] A baffle plate 5 is attached to the front end of the outer tube 4. The baffle plate 5 is circular disk-shaped and is firmly connected to the outer tube 4 via pins 6 that terminate at the baffle plate 5 and run perpendicular to the plane of the baffle plate 5. Of course, other fastening forms are also possible.

[0046] Fig. 3 shows individual representations of the aforementioned components.

[0047] How Fig. 3 shows, the rear end of the nozzle needle 3 is connected to a spray device 7.

[0048] The front end of the nozzle needle 3 is a needle tip 8, which is part of a needle valve. The needle tip 8 is mounted in a head portion 9 of the paint tube 2 and forms a valve assembly with it.

[0049] According to the invention, an electric motor 10, which is arranged coaxially with the centrifuge nozzle, serves as the drive unit of the centrifuge apparatus 1. The electric motor 10 is a direct drive, whereby in the present case, the electric motor 10 is designed in the form of a brushless DC motor, i.e., a permanent magnet motor.

[0050] The electric motor 10 is designed as a hollow shaft motor, wherein a section of the paint tube 2 with the nozzle needle 3 mounted therein is guided in the hollow shaft 11 of the hollow shaft motor. Fig. 2 shows the motor winding 12 of the electric motor 10 surrounding the hollow shaft 11.

[0051] As the Fig. 1 to 3 show that the electric motor 10 is part of an assembly, at the front end of which there is a high-precision clamping connection 13 and at the rear end of which there is an interface element 14 for connecting the spray gun 7.

[0052] In the area of ​​the front end of the outer tube 4, there is a bearing 15, which serves to support the paint tube 2 in the outer tube 4. However, this is not mandatory.

[0053] The high-precision clamp connection 13 is firmly connected to the outer tube 4. The rotational movement of the rotor of the electric motor 10 causes the high-precision clamp connection 13 and thus the outer tube 4 with the baffle plate 5 attached to it to rotate, i.e., the outer tube 4 and the baffle plate 5 rotate at the speed of the electric motor 10 about an axis of rotation running along the axis of symmetry of the outer tube 4 and the hollow shaft 11 of the electric motor 10.

[0054] In contrast, the paint tube 2 and the nozzle needle 3 are fixed units that do not rotate with the rotor of the electric motor 10. The spray gun 7 also forms a fixed unit.

[0055] The distance between the baffle plate 5 and the front end of the paint tube 2 can be adjusted using the high-precision clamp connection 13.

[0056] As the Fig. 1 to 2, the assembly with the electric motor 10 has an electrical connection 16 for supplying power to the electric motor 10.

[0057] The spray gun 7 has a connection 17 for supplying a coating material, wherein liquid coating material can be supplied via the connection 17 and introduced into the paint tube 2.

[0058] At the rear of the spray gun 7, there is a mechanical adjustment device in the form of a nut 19, which can be rotated against a fixed scale 20. By rotating the adjustment element, the needle opening and thus the flow of coating material can be varied.

[0059] The mechanical adjustment means acts on an adjustment mechanism in the form of a piston 21, which is operatively connected to springs 22.

[0060] The functioning of the centrifuge 1 is explained below using the Fig. 1 to 4 explained.

[0061] Liquid coating material, which is fed to the centrifuge 1 via connection 17, is guided in the paint tube 2 between its inner wall and the nozzle needle 3 and directed to the front end of the centrifuge nozzle. The coating material is expelled via the needle valve and directed against the impact plate 5.

[0062] The impact plate 5 is rotated about its axis of symmetry by means of the electric motor 10, the frequency of these rotations being in the range of several thousand revolutions per minute.

[0063] The coating material is guided radially outwards on the impact plate 5 by the centrifugal force acting on the rotating impact plate 5, reinforced at the tear-off edge of the impact plate 5 and thus guided against a surface to be coated.

[0064] Advantageously, the front end of the centrifugal nozzle with the impact plate 5 is guided in a preferably rotationally symmetrical cavity of an object to be coated, so that the inside of the object is coated with the centrifugal device 1.

[0065] The coating process can be adjusted by adjusting the quantity and flow rate of the coating material in the paint tube 2. To do this, the needle opening of the needle valve is adjusted. This adjustment is performed by a user by attaching the mechanical adjustment device to the spray gun 7. List of reference symbols 1 centrifuge 2 paint tubes 3 nozzle needle 4 Outer tube 5 impact plate 6 pin 7 Spray gun 8 needle tip 9 Headboard 10 Electric motor 11 Hollow shaft 12 Motor winding 13 High-precision clamping connection 14 Interface element 15 warehouses 16 connection 17 Connection 19 Mother 20 scale 21 pistons 22 spring 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] DE 10 2007 039 974 A1

[0006]

Claims

[1] Centrifugal apparatus (1) for coating objects, comprising a centrifugal nozzle, to the front end of which is connected a baffle plate (5) which is set into a rotary movement about a rotational axis by means of a drive, wherein a coating material is dispensed via the front end of the centrifugal nozzle and guided against the baffle plate (5), wherein the coating material is atomised on the baffle plate (5) and deflected in the direction of a surface of an object to be coated, characterized by that the drive is an electric motor (10) which is arranged coaxially to the axis of rotation of the impact plate (5) and to the centrifugal nozzle. [2] Centrifugal apparatus (1) according to claim 1, characterized by that the electric motor (10) is an electric direct drive. [3] Centrifugal apparatus (1) according to one of claims 1 or 2, characterized by that the electric motor (10) is a brushless DC drive. [4] Centrifugal apparatus (1) according to one of claims 1 to 3, characterized by that the electric motor (10) is a hollow shaft motor. [5] Centrifugal apparatus (1) according to one of claims 1 to 4, characterized by that the centrifugal nozzle has a paint tube (2) and a nozzle needle (3) guided in the latter and running coaxially thereto. [6] Centrifugal apparatus (1) according to claim 5, characterized by that the nozzle needle (3) and a needle valve at the tip of the nozzle needle (3) are fixed units. [7] Centrifugal apparatus (1) according to claim 6, characterized by that a needle tip (8) is present at the front end of the nozzle needle (3) facing the baffle plate (5). [8] Centrifugal apparatus (1) according to one of claims 4 to 6, characterized by that the paint tube (2) with the nozzle needle (3) is guided in a hollow shaft (11) of the hollow shaft motor. [9] Centrifugal apparatus (1) according to one of claims 5 to 8, characterized bythat the coating material is guided between the nozzle needle (3) and the inner wall of the paint tube (2). [10] Centrifugal apparatus (1) according to one of claims 6 to 9, characterized by that the flow of the coating material in the needle valve is regulated by means of the nozzle needle (3). [11] Centrifugal apparatus (1) according to one of claims 9 and 10, characterized by that the flow of the coating material is adjusted by adjusting the distance between the needle tip (8) and the baffle plate (5) and / or by adjusting a needle opening of the needle valve. [12] Centrifugal apparatus (1) according to claim 11, characterized by that it has a spray device (7) with a mechanical adjustment means for adjusting the distance of the needle valve to the baffle plate (5) and / or the provision of a needle opening of the needle valve. [13] Centrifugal apparatus (1) according to one of claims 10 to 12, characterized bythat liquid coating material applied via the needle tip (8) is guided against the impact plate (5), guided outwards by the centrifugal force of the rotating impact plate (5), atomised at a tear-off edge of the impact plate and guided against the surface to be coated. [14] Centrifugal apparatus (1) according to one of claims 5 to 13, characterized by that the paint tube (2) runs in an outer tube (4) which rotates with a rotor of the electric motor (10). [15] Centrifugal apparatus (1) according to claim 14, characterized by that the impact plate (5) is firmly connected to the outer tube (4). [16] Centrifugal apparatus (1) according to claim 14 or 15, characterized by that the outer tube (4) is coupled to the electric motor (10) by means of a high-precision clamp connection (13). [17] Centrifugal apparatus (1) according to one of claims 15 and 16, characterized bythat the distance between the paint tube (2) and the baffle plate (5) can be adjusted using the high-precision clamp connection (13). [18] Centrifugal apparatus (1) according to one of claims 14 to 17, characterized by that at the front end of the outer tube (4) there is a bearing (15) for supporting the paint tube (2). [19] Centrifugal apparatus (1) according to one of claims 1 to 18, characterized by that the impact plate (5) is circular disc-shaped.

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