Shaping-air ring for a rotary atomiser, and rotary atomiser with shaping-air ring

Abstract

The shaping-air ring according to the invention for a rotary atomiser comprises annularly arranged shaping-air nozzles (5), each having a nozzle channel (8). The nozzle channel (8) has a channel inlet orifice (9) and a channel outlet orifice (10), wherein the channel outlet orifice (10) has an outlet orifice height (t2) and an outlet orifice width (a2). The outlet orifice width (a2) is greater than the outlet orifice height (t2).

Description

[0001]Description Shaping air ring for a rotary atomizer and rotary atomizer with shaping air ring Technical field The invention relates to a shaping air ring for a rotary atomizer and a rotary atomizer with a shaping air ring. Such a rotary atomizer is generally used to coat workpieces with coating material and for this purpose comprises a bell-shaped shaft and a bell-shaped plate arranged thereon. With the help of shaping air nozzles and the rotating bell-shaped plate, a fine, homogeneous spray jet is generated from the coating material, which is used to coat the workpiece. State of the art A shaping air ring with numerous shaping air nozzles for a rotary atomizer is known from the prior art EP 2099 570 B1. The shaping air nozzles are arranged in a shaping air nozzle ring and aligned coaxially with the bell-shaped plate shaft.The shaping air nozzles emit a shaping air stream coaxially to the bell cup shaft to the front in order to form a spray jet emitted by the bell cup. In a first embodiment of the shaping air ring described in EP 2099 570 B1, the shaping air nozzles in the shaping air ring are aligned such that the central axis of the shaping air stream passes radially outside the spray edge of the bell cup without touching the bell cup, wherein the radial distance between the central axis of the shaping air stream and the spray edge is approximately 3 mm. In this embodiment, the axial length of the bell cup is relatively short. The ratio between the radius of the spray edge and the axial length of the outer surface of the bell cup is approximately 1.6. The radius of the bell cup is therefore greater than its axial length.In this first embodiment, the air consumption for the shaping air can be kept low because the outlets of the shaping air nozzles are located close to the spray edge. However, this has the disadvantage that the individual air streams generated by the shaping air nozzles are still clearly recognizable as separate air streams at the spray edge. There is therefore no homogeneous shaping air stream at the spray edge. As a result, the trajectory of the individual paint droplets is influenced differently by the shaping air. In a second embodiment of the air guiding ring described in EP 2099 570 B1, the shaping air nozzles in the shaping air ring are aligned such that the center axis of the shaping air stream impinges on the outer surface of the bell cup with a radial overlap of 2 mm. The shaping air jet is therefore directed directly onto the outer surface of the bell cup. In this second embodiment, the axial length of the bell cup is relatively large.The axial extent of the outer surface is greater than the radius of the spray edge of the bell cup. As a result, the individual air streams generated by the shaping air nozzles merge into one another even before they hit the spray edge. A homogeneous shaping air stream therefore hits the spray edge. As a result, the individual paint droplets are influenced more uniformly in their trajectory by the shaping air than in the first embodiment. However, the second embodiment has the disadvantage that the air consumption for the shaping air is greater than in the first embodiment because the outlets of the shaping air nozzles are further away from the spray edge. Description of the invention One object of the invention is to provide a shaping air ring for a rotary atomizer with which both homogeneous shaping air can be provided and at the same time the compressed air consumption for generating the shaping air is minimized.Advantageously, the inventive shaping air ring influences the paint droplets extremely evenly. This object is achieved by a shaping air ring for a rotary atomizer having the features specified in claim 1. The inventive shaping air ring for a rotary atomizer comprises annularly arranged shaping air nozzles, each having a nozzle channel. The nozzle channel has a channel inlet opening and a channel outlet opening, wherein the channel outlet opening has an outlet opening height and an outlet opening width. The outlet opening width is greater than the outlet opening height. Advantageous further developments of the invention arise from the features specified in the dependent claims. In one embodiment of the inventive shaping air ring, the channel inlet opening has an inlet opening width, wherein the inlet opening width and the outlet opening width are different sizes.In another embodiment of the molding air ring according to the invention, the inlet opening width is smaller than the outlet opening width. Furthermore, in the molding air ring according to the invention, the channel outlet opening can have a cross-sectional area in the range of 0.3 mm. 2 up to 1.5 mm 2Furthermore, in the shaping air ring according to the invention, it can be provided that the ratio of inlet opening width to outlet opening width lies between 1 and 4. Advantageously, in the shaping air ring according to the invention, the number of channel outlet openings is between 40 and 80. In a further development of the shaping air ring, the shaping air nozzles are designed and arranged such that the channel outlet openings of two adjacent shaping air nozzles touch each other. In an additional embodiment of the shaping air ring according to the invention, axially extending webs are provided which delimit the nozzle channels. In a further development of the shaping air ring according to the invention, there is a groove between each of the webs. In an additional development of the shaping air ring according to the invention, the webs taper in the downstream direction.This has the advantage that the air streams expand and combine to form a homogeneous overall air stream. In a further embodiment, the shaping air ring according to the invention comprises an outer air guide ring and an inner air guide ring, which delimit the nozzle channels. The shaping air ring according to the invention is advantageously made of solvent-resistant plastic, aluminum, or titanium. Furthermore, a rotary atomizer is proposed which comprises the shaping air ring described above and a spray bell plate with a spray edge. The nozzle channel is designed such that the shaping air jet generated by the shaping air nozzle is directed towards the spray edge. This ensures that the air does not bounce off the bell plate. The coating material cloud is thus more concentrated.Directing the shaping air jet towards the edge has the advantage that the air acts directly where the atomization takes place and supports it. In a further development of the rotary atomizer, the nozzle channel is designed so that the shaping air jet hits the spray bell plate between 0 and 3 mm in front of the spray edge. This makes the coating material cloud larger and less concentrated. In another further development of the rotary atomizer, the nozzle channel is designed so that the shaping air jet does not touch the spray edge. The distance between the spray edge and the shaping air jet is preferably between 0 and 3 mm. This makes the coating material cloud more concentrated. Directing the shaping air jet towards the edge and past the edge makes it possible to direct the air inwards. This allows a narrower spray pattern to be created.In another development of the rotary atomizer, air nozzles are provided which are arranged concentrically to the shaping air nozzles. The shaping air nozzles and the air nozzles can be operated independently of one another. Brief description of the drawings The invention is explained in more detail below with several exemplary embodiments using 21 figures. Figure 1 shows a first possible embodiment of the shaping air ring according to the invention together with a bell cup in longitudinal section. Figure 2 shows the first embodiment of the shaping air ring according to the invention in an exploded view. Figure 3 shows the first embodiment of the shaping air ring according to the invention in longitudinal section. Figure 4 shows the first embodiment of the shaping air ring according to the invention in a front view. Figure 5 shows the outer air guide ring of the shaping air ring in longitudinal section. Figure 6 shows the inner air guide ring of the shaping air ring in longitudinal section.Figure 7 shows a section of the outer air guide ring in a three-dimensional view. Figure 8 shows a possible embodiment of a rotary atomizer with the shaping air ring according to the invention in a three-dimensional view. Figure 9 shows the downstream end of the rotary atomizer with the shaping air ring in longitudinal section. Figure 10 shows a second possible embodiment of the shaping air ring according to the invention in a three-dimensional view. Figure 11 shows the second embodiment of the shaping air ring according to the invention in a three-dimensional view, partially in section. Figure 12 shows the inner air guide ring in the second embodiment of the shaping air ring according to the invention in a three-dimensional view. Figure 13 shows the outer air guide ring in the second embodiment of the shaping air ring according to the invention in a three-dimensional view.Figure 14 shows a section of the outer air guide ring in a three-dimensional view. Figure 15 shows a further embodiment of the outer air guide ring in a three-dimensional view. Figure 16 shows a section of the further embodiment of the outer air guide ring in a three-dimensional view. Figure 17 shows a third possible embodiment of the shaping air ring according to the invention together with the bell cup in a three-dimensional view. Figure 18 shows a section of the third embodiment of the shaping air ring according to the invention in a front view. Figure 19 shows a section of the third embodiment of the shaping air ring according to the invention together with the bell cup in longitudinal section. Figure 20 shows a possible embodiment of the downstream section of the rotary atomizer in longitudinal section.Figure 21 shows a possible embodiment of a drive turbine and a drive shaft of the rotary atomizer in a three-dimensional view. Ways of Implementing the Invention Figures 1 to 7 show a first possible embodiment of the shaping air ring 1 according to the invention, or parts of the shaping air ring 1 according to the invention. In the first embodiment, the shaping air ring 1 comprises an outer air guide ring 11 and an inner air guide ring 12. The outer air guide ring 11 and the inner air guide ring 12 are preferably designed such that the inner air guide ring 12 can be inserted into the outer air guide ring 11. In order to define the relative position of the two air guide rings 11 and 12 to each other, the outer air guide ring 11 can have a stop 11.1 on its inside and the inner air guide ring 12 can have a stop 12.1 on its outside.During assembly, the two air guide rings 11 and 12 are pushed together up to the two stops 11.1 and 12.1. The outer air guide ring 11 is preferably arranged concentrically to the inner air guide ring 12. The longitudinal axis L of the outer air guide ring 11 and the longitudinal axis L of the inner air guide ring 11 are thus congruent. In the embodiment according to Figures 1 to 7, the outer air guide ring 11 has a series of webs 6 on its downstream end section, which are arranged in a ring on the inside of the outer air guide ring 11. In the assembled state, the outer side of the downstream end section 12.2 of the inner air guide ring 12 rests against the webs 6. Alternatively, the webs 6 can also be part of the inner air guide ring 12, as shown by way of example in Figure 12.In this case, in the assembled state, the inside of the downstream end section of the outer air guide ring 11 rests against the webs 6. In the embodiment according to Figures 1 to 7, the outer air guide ring 11 has a groove 7 between each two webs 6. Two adjacent webs 6 form the left and right sides, and the groove 7 between them forms the underside of a shaping air duct 8. The top side of the shaping air duct 8 is formed by the outside of the inner air guide ring 12. At its upstream end, the shaping air duct 8 has a duct inlet opening 9 and at its downstream end a duct outlet opening 10. The shaping air duct 8 is also referred to below as the nozzle duct. The outer surface of the downstream end section 12.2 of the inner air guide ring 12 (nozzle wall 5.2) can have a smooth contour (see Figure 2). The outer radius of the downstream end section 12.2 is then constant, at least in the area of ​​the shaping air nozzles 5. In this case, the channel outlet opening 10 at the downstream end of the nozzle channel 8 has an outlet opening height t2. The outlet opening 5.1 of the shaping air nozzle 5 therefore has the outlet opening height t2. Instead, the outer side of the downstream end section 12.2 can also have a wavy contour (similar to that in Figure 12). The outer radius of the downstream end section 12.2 is then not constant, at least in the area of ​​the shaping air nozzles 5. In this case, the channel outlet opening 10 at the downstream end of the nozzle channel 8 has an outlet opening height t2'. The outlet opening 5.1 of the shaping air nozzle 5 therefore then has the outlet opening height t2'. In both cases, the outlet opening width a2 is greater than the outlet opening height t2 or t2'. A shaping air nozzle 5 comprises the shaping air channel 8, the channel inlet opening 9, and the channel outlet opening 10.The duct outlet opening 10 forms the outlet opening 5.1 of the shaping air nozzle 5, which is also referred to as the nozzle outlet 5.1. A large number, preferably 20 to 80, of these shaping air nozzles 5 are arranged in a ring in the shaping air ring 1. The more shaping air nozzles 5 there are, the more even the air distribution at the spray edge 3.1. However, as the number of nozzles increases, the manufacturing effort generally also increases. It has been shown that 40 shaping air nozzles are sufficient for a bell cup with a 50 mm diameter to distribute the shaping air sufficiently evenly at the spray edge, and the manufacturing effort is kept within limits. For a 30 mm or 70 mm bell cup, the number of shaping air nozzles can be smaller or larger. For example, a bell cup with a 30 mm diameter can be equipped with 30 shaping air nozzles. A bell cup with a diameter of 70 mm preferably has around 60 shaping air nozzles.The shaping air nozzles 5 are preferably arranged in a nozzle ring. It is also advantageous if they are aligned coaxially to the longitudinal axis L. The shaping air nozzles 5 are preferably arranged equidistantly. The angle α (see Figure 4) between two adjacent shaping air nozzles 5 is therefore constant between all adjacent shaping air nozzles. The shaping air nozzles 5 ensure, among other things, that the paint particles are moved forward, i.e. towards the workpiece (not shown). In the embodiment according to Figures 1 to 7, the webs 6 taper in the downstream direction. The webs 6 each have the shape of a wedge, with the wedge tip being located on the downstream side of the shaping air channel 8 and being blunt. Because the webs 6 taper in the downstream direction, the inlet opening widths a1 of the shaping air nozzles 5 are smaller than their outlet opening widths a2.As a result, the air flowing through the shaping air nozzles 5 is expanded like a fan. Instead, the webs 6 can also have a constant width over their entire length (not shown in the figures). In this case, the inlet opening width a1 and the outlet opening width a2 are the same. In the shaping air ring 1, the channel length b8 of the nozzle channel 8 can be three to five times longer than its outlet opening width a2. The longer the nozzle channel 8, the greater its air resistance. However, the longer nozzle channel 8 allows the shaping air jet to be directed even more precisely. It is therefore possible to define even more precisely where the shaping air jet should hit the paint particles. In the shaping air ring 1, the length b8 of the nozzle channel 8 can also be three to five times longer than its inlet opening width a1. Here too, the longer the nozzle channel 8 is, the greater its air resistance becomes.On the other hand, the shaping air jet can be directed even more precisely thanks to the longer nozzle channel. It is therefore possible to define even more precisely where the shaping air jet should hit the paint particles. If required, the shaping air ring 1 according to the invention can also be equipped with additional air nozzles 4. The additional air nozzles 4 primarily serve to concentrate the sprayed particle stream or the stream to be sprayed. The additional air nozzles 4 can be designed like the shaping air nozzles 5. This has the advantage that they are easy to clean. In principle, each of the additional air nozzles 4 has a longitudinal axis. In one embodiment, the longitudinal axes of the additional air nozzles 4 are aligned parallel to the longitudinal axis L of the shaping air ring 1. The angle of inclination at which the longitudinal axis of an additional air nozzle 4 is inclined in the downstream direction towards the longitudinal axis L of the shaping air ring 1 is therefore 0°.In a further embodiment, the longitudinal axes of the additional air nozzles 4 are inclined in the downstream direction towards the longitudinal axis L. One such embodiment is shown, for example, in Figure 10. This causes the shaping air jets 16 generated by the additional air nozzles 4 to be inclined in the downstream direction towards the longitudinal axis L. The angle of inclination can, for example, be between 0° and 20°. The angle of inclination influences the air flow at the spray edge 3.1 and also the air flow downstream of the spray edge 3.1. Thus, the angle of inclination also influences the bundling of the coating material cloud and any air vortices that may arise. The choice of the angle of inclination depends on the requirements to be met. The angle of inclination is usually one of several parameters. Other parameters can be the radial alignment to the spray edge and the design of the additional air.In addition, it can be provided that the additional air nozzles 4 are designed and / or arranged in such a way that the air flowing through them is given a swirl (not shown in the figures). To achieve this, the longitudinal axis of the additional air nozzle 4 is arranged at a laterally incline (skew to the longitudinal axis LA). The additional air nozzles 4 can be arranged at a laterally incline for this purpose. This creates a swirl, and the air emerging from the additional air nozzles 4 rotates along the longitudinal axis L. This is particularly advantageous in the case of a highly concentrated cloud of coating material. Fewer undesired turbulences form. This advantage is particularly evident when the rotary atomizer is arranged stationary. It can be provided that the downstream end of the inner air guide ring 12 is flush with the outer air guide ring 11, as shown, for example, in Figure 3.In a further embodiment, the inner air guide ring 12 is not flush with the outer air guide ring 11, but is offset axially rearward. In Figure 7, the dashed line t2'' indicates the downstream end of the inner air guide ring 12. The dashed line t2'' thus indicates the position of the downstream outer edge of the inner air guide ring 12. Instead, the inner air guide ring 12 can also be offset axially forward (not shown in the figures). The inner air guide ring 12 then protrudes beyond the outer air guide ring 12, viewed in the axial direction. Figure 8 shows a possible embodiment of a rotary atomizer 20. The shaping air ring 1 is located at its downstream end. The rotary atomizer 20 shown in Figure 8 has a flange 23 at the upstream end with which it can be attached to a manipulator.The shaping air ring 1 installed in the rotary atomizer 20 has, in addition to the shaping air nozzles 5, additional air nozzles 4. However, the additional air nozzles 4 are not absolutely necessary. In the embodiment shown in Figure 9, the shaping air nozzles 5 are aligned such that the shaping air jet 15 generated by them strikes the spray edge 3.1 of the bell cup 3. Instead, the shaping air nozzles 5 can also be aligned such that the shaping air jet 15 generated by them (identified by reference numeral 15' in Figure 9) strikes the outside of the bell cup 3 at a defined point. This point lies, viewed upstream, in front of the spray edge 3.1. The distance c between the point at which the shaping air jet 15' strikes the bell cup 3 and the spray edge 3.1 is preferably between 0 and 3 mm.The rotary atomizer 20 is advantageously designed such that the shaping air nozzles 5 and the additional air nozzles 4 can be operated independently of one another. One possible embodiment of the downstream section of the rotary atomizer 20 is shown in Figure 9. The rotary atomizer 20 comprises a material line 30 to convey the coating material downstream toward the bell cup 3. After the coating material has exited the material line 30, it encounters a distributor plate 32. The largest portion of the coating material is transported radially outward to the inner surface of the bell cup 3 with the aid of the distributor plate 32. A small portion of the coating material may be thrown back upstream, toward the material line 30. This material is then guided into a receiving chamber 34.At least one wall of the receiving chamber 34 is part of the bell cup 3, so that it rotates with the bell cup. Due to the resulting rotational force, the thrown-back material is guided via a discharge line 36 to the outer edge of the distributor plate 32 and thus also to the inner surface of the bell cup 3. In this way, the thrown-back material is not lost and does not accumulate inside the rotary atomizer 20. Both the inner surface of the bell cup 3 and the receiving chamber 34 can be cleaned via rinsing agent lines 38. The shaping air ring can also be formed as a single piece. The single-piece variant of the shaping air ring is designated by the reference numeral 100 and shown in Figures 10 and 11. In this embodiment, the inner air guide ring is a component of the shaping air ring and is inseparably connected to it.Furthermore, it can be provided that the nozzle channels 8 are formed entirely within one component. This is also shown in Figures 10 and 11. Alternatively, it can be provided that the shaping air ring is constructed in several parts, i.e., comprises several components, but the nozzle channels 8 are formed entirely within one component. The separation of the components therefore takes place outside the area of ​​the nozzle channels 8. Figure 12 shows a further embodiment of an inner air guide ring 212. In this embodiment, the webs 6 are part of the inner air guide ring 212. When the shaping air ring is assembled, the webs 6 of the inner air guide ring 212 rest against the inside of the downstream end section of the outer air guide ring 11. In this embodiment, the outer air guide ring 11 preferably has no webs and grooves (not shown).Just like the inner air guide ring 12 according to Figures 1 to 7, the inner air guide ring 212 according to Figure 12 has a groove 7 between each two webs 6. Two webs 6 and a groove 7 each form the left, right and lower sides of a shaping air duct 8. The upper side of the shaping air duct 8 is formed by the inside of the outer air guide ring. At its upstream end, the shaping air duct 8 has a duct inlet opening 9 and at its downstream end a duct outlet opening 10. Here too, a shaping air nozzle 5 comprises the shaping air duct 8, the duct inlet opening 9 and the duct outlet opening 10. The duct outlet opening 10 forms the nozzle outlet 5.1 of the shaping air nozzle 5. Here too, a plurality, preferably 40 to 80, of these shaping air nozzles 5 are arranged in a ring in the shaping air ring. The shaping air nozzles 5 are preferably arranged equidistantly.To supply the additional air nozzles 4 in the outer air guide ring 211 (see Figure 13) with compressed air, bores 14 can be provided in the inner air guide ring 212 (see Figure 12). The compressed air can be guided to the nozzles 4 through the bores 14. Compressed air can be supplied to the shaping air nozzles 5 via bores 17 and an annular groove 18 provided in the inner air guide ring 212. The compressed air flows through the bores 17, the annular groove 18, the channel inlet openings 9 and the nozzle channels 8 to the channel outlet openings 10. In the further embodiment of an outer air guide ring 211 shown in Figures 13 and 14, the webs 6 are shorter than in the outer air guide ring 11 according to Figure 7. The length b6 of the webs 6 is therefore shorter than the channel length b8. If the webs 6, as shown in Figures 13 and 14, do not extend to the downstream edge 211.2 of the outer air guide ring 211, the channel outlet openings 10 touch each other. The webs 6 each have the shape of a wedge, with the wedge tip located on the downstream side of the shaping air channel 8. Unlike the air guide ring 11 according to Figures 1 to 7, the wedge is not blunt, but pointed. In the air guide ring 211, the wedge tip does not reach as far as the downstream edge 211.2 of the air guide ring 211. An additional embodiment of an outer air guide ring 311 is shown in Figures 15 and 16. Here, too, the webs 6 taper in the downstream direction. The webs 6 each have the shape of a wedge, with the wedge tip located on the downstream side of the shaping air channel 8. Unlike the air guide ring 211 according to Figures 13 and 14, the wedge tip of the air guide ring 311 lies on the downstream edge 311.2 of the air guide ring 311.The length b6 of the webs 6 is equal to the channel length b8. In this embodiment of the air guide ring 311, the channel outlet openings 10 just touch each other. Another possible embodiment of the shaping air ring 400 is shown in Figures 17, 18 and 19. In addition to the outer air guide ring 411 and the inner air guide ring 412, the shaping air ring 400 also comprises an intermediate ring 413. The intermediate ring 413 is located between the outer air guide ring 411 and the inner air guide ring 412. Preferably, the outer air guide ring 411, the intermediate ring 413 and the inner air guide ring 412 are arranged concentrically. Their longitudinal axes are congruent. The intermediate ring 413 has webs 6 and grooves 7 on its outer and inner sides. When the forming air ring 400 is assembled, the outer webs 6 of the intermediate ring 413 rest against the inside of the downstream end section of the outer air guide ring 411.The inner webs 6 of the intermediate ring 413 rest against the outer side of the downstream end section of the inner air guide ring 412. Here, too, two webs 6 and a groove 7 form three sides of a shaping air channel 8. The fourth side of the outer shaping air channel 8 is formed by the inner side of the outer air guide ring 411. The fourth side of the inner shaping air channel 8 is formed by the outer side of the inner air guide ring 412. The shaping air channel 8 has a channel inlet opening at its upstream end and a channel outlet opening at its downstream end. In this embodiment of the shaping air ring 400, a shaping air nozzle 5 also comprises the shaping air channel 8, the channel inlet opening 9 and the channel outlet opening 10. The channel outlet opening 10 forms the nozzle outlet 5.1 of the shaping air nozzle 5. A plurality, preferably 40 to 80, of these shaping air nozzles 5 are arranged in a ring in the shaping air ring 1.The shaping air nozzles 5 are preferably arranged equidistantly. The shaping air nozzles 5 can be crescent-shaped or lens-shaped, as shown in Figures 17 and 18. The additional air nozzles 4 can also be crescent-shaped or lens-shaped, as shown in Figures 17 and 18. Such nozzle channels are easy to manufacture. In the shaping air ring 400, the shaping air nozzles 5 and the additional air nozzles 4 are arranged on the same plane. In addition, the additional air nozzles 4 are closer to the spray edge 3.1. Since the shaping air nozzles 5 and the additional air nozzles 4 are arranged on the same plane, there is no step between the shaping air nozzles 5 and the additional air nozzles 4. As a result, the area between the two air streams is smaller and the area is also less contaminated by turbulence. The embodiment according to Figures 17 - 19 has the advantage that it can be dismantled and is therefore easy to clean.The air channels 8 and the grooves 7 are openly accessible over their entire length and can therefore be cleaned more easily. One possible embodiment of the downstream section of the rotary atomizer 20 is shown in section in Figure 20. The rotary atomizer 20 comprises a drive shaft 50, which is preferably designed as a hollow shaft. A material line can be provided inside the hollow shaft, via which material the coating material can be transported in the direction of the spray bell plate 3. In the embodiment shown in Figure 20, the drive shaft 50 is driven by a drive turbine 51. The drive turbine 51, in turn, is preferably driven by compressed air. One possible embodiment of the drive turbine 51 and the drive shaft 50 are shown in a three-dimensional view in Figure 21. In one embodiment of the rotary atomizer, the spray bell plate 3 is screwed onto the drive shaft 50.In order to attach the spray bell plate 3 to the drive shaft 50 or to remove it from the drive shaft 50, the drive shaft 50 can be blocked so that it can no longer rotate. For this purpose, a locking device 52 is provided. In addition, one or more slots 50.1 are provided at the upstream end of the drive shaft 50. The locking device 52 has a movably mounted locking pin 53, wherein the locking pin 53 and the slot 50.1 are coordinated with one another. When the locking pin 53 protrudes into the slot 50.1, the drive shaft 50 is blocked. If the locking pin 53 is outside the slot 50.1 (see Figure 20), the drive shaft 50 can rotate. Provision can be made for the locking pin 53 to be pressed into the slot 50.1 by hand.However, it can also be provided that the locking device 52 has a compressed air control connection 55, via which the locking pin 53 is pressed into the slot 50.1 by means of compressed air. With the help of a spring 54, the locking pin 53 can be pretensioned so that it rests outside the slot 50.1 in the non-actuated state. If the locking pin 53 is actuated, i.e. pressed into the slot 50.1, a vent opening 56 ensures that the air in the housing below the locking pin 53 is discharged and cannot build up back pressure. The locking can be achieved, for example, by means of a compressed air control. For this purpose, a manually operated pneumatic valve can be provided on the rear part of the rotary atomizer. For example, a push button can be provided in the housing. However, the pneumatic valve can also be provided outside the rotary atomizer.It is also possible to actuate the locking mechanism using an electrically controlled pneumatic valve, which is controlled by a controller. The locking pin 53 can only protrude into the slot 50.1 when the drive shaft 50 is in the correct rotational position. If there are several, for example four, slots 50.1, the drive shaft 50 only needs to be rotated by just under 90° in the worst case scenario so that the locking pin 53 can be pressed into one of the four slots 50.1. The preceding description of the embodiments according to the present invention serves only for illustrative purposes. Various changes and modifications are possible within the scope of the invention.For example, the various components of the shaping air rings shown in Figures 1 to 20 can also be combined with one another in a manner other than that shown in the figures and can also be used for an atomizer other than the rotary atomizer shown in Figures 8, 9 and 20. List of reference symbols 1 Shaping air ring 3 Spray bell plate 3.1 Spray edge 4 Additional air nozzle 5 Shaping air nozzle 5.1 Outlet opening / nozzle outlet 5.2 Nozzle wall 6 Web 7 Groove 8 Nozzle channel 9 Channel inlet opening 10 Channel outlet opening 11 Outer air guide ring 11.1 Stop 11.2 Downstream edge 12 Inner air guide ring 12.1 Stop 12.2 Downstream end section 14 Bore 15 Shaping air jet 15' Shaping air jet 16 Shaping air jet 17 Bore 18 Annular groove 20 Rotary atomizer 21 Union nut 22 Seal 23 Flange 30 Material line 32 Distributor plate 34 Receiving chamber 36 Discharge line 38 Flushing line 50 Drive shaft 50.1 Slot in the drive shaft 51 Drive turbine 52 Locking device 53 Locking pin 54 Spring 55 Compressed air control connection 56 Vent opening 100 Shaping air ring 111 Outer air guide ring 112 Inner air guide ring 211 Outer air guide ring 211.2 Downstream edge 212 Inner air guide ring 311 Outer air guide ring 311.2 Downstream edge 400 Shaping air ring 411 Outer air guide ring 412 Inner air guide ring 413 Intermediate ring a1 Inlet opening width / Inlet opening width a2 Outlet opening width / Outlet opening width b6 Length of the web b8 Length of the nozzle channel c Distance to the spray edge L Longitudinal axis of the shaping air ring LA Longitudinal axis of the nozzle channel t2 Outlet opening height t2' Outlet opening height t2'' Position of the outer edge of the inner air guide ring x x-axis y y-axis z z-axis α angle.

Claims

Patent claims 1. Shaping air ring for a rotary atomizer, - which comprises annularly arranged shaping air nozzles (5), each having a nozzle channel (8), - in which the nozzle channel (8) has a channel inlet opening (9) and a channel outlet opening (10), - in which the channel outlet opening (10) has an outlet opening height (t2) and an outlet opening width (a2), and - in which the outlet opening width (a2) is greater than the outlet opening height (t2).

2. Shaping air ring according to patent claim 1, - in which the channel inlet opening (9) has an inlet opening width (a1), and - in which the inlet opening width (a1) and the outlet opening width (a2) are different sizes.

3. Forming air ring according to claim 1 or 2, wherein the inlet opening width (a1) is smaller than the outlet opening width (a2).

4. Forming air ring according to one of claims 1 to 3, wherein the channel outlet opening (10) has a cross-sectional area in the range of 0.3 mm 2 up to 1.5 mm2 5. Forming air ring according to one of claims 1 to 4, in which the ratio of inlet opening width (a1) to outlet opening width (a2) is between 1 and 4.

6. Forming air ring according to one of claims 1 to 5, in which the number of channel outlet openings (10) is in the range between 40 and 80.

7. Shaping air ring according to one of claims 1 to 6, in which the channel outlet openings (10) of two adjacent shaping air nozzles (5) touch each other.

8. Shaping air ring according to one of claims 1 to 7, - with axially extending webs (6), and - in which the nozzle channels (8) are delimited by the webs (6).

9. Shaping air ring according to claim 8, in which a groove (7) is present between each of the webs (6).

10. Shaping air ring according to claim 8 or 9, in which the webs (6) taper in the downstream direction.

11. The molding air ring according to one of claims 1 to 10, comprising an outer air guide ring (11) and an inner air guide ring (12), and wherein the nozzle channels (8) are delimited by the outer air guide ring (11) and the inner air guide ring (12).

12. The molding air ring according to one of claims 1 to 11, made of solvent-resistant plastic, aluminum, or titanium. 13.Rotary atomizer with a shaping air ring according to one of claims 1 to 12, - in which a spray bell plate (3) with a spray edge (3.1) is provided, - in which the nozzle channel (8) is designed such that the air that can be generated by the shaping air nozzle (5). Shaping air jet (15) is directed onto the spray edge (3.1).

14. Rotary atomizer according to claims 1 to 12, - in which a spray bell plate (3) with a spray edge (3.1) is provided, - in which the nozzle channel (8) is designed such that the shaping air jet (15') generated by the shaping air nozzle (5) strikes the bell plate (3) 0 to 3 mm before the spray edge (3.1).

15. Rotary atomizer according to claims 13 or 14, - in which air nozzles (4) are arranged concentrically to the shaping air nozzles (5), and - in which the shaping air nozzles (5) and the air nozzles (4) can be operated independently of one another.

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