Abstract
A coating device comprises at least one application apparatus to discharge a coating agent from at least one coating agent nozzle. The application apparatus is configured to apply an oscillation to at least one of the coating agent and at least one coating agent jet such that at least one of the coating agent and the at least one coating agent jet break up into droplets.
Claims
1. A painting installation, for coating a motor vehicle body, comprising: at least one painting robot, the at least one painting robot including a plurality of axes; at least one paint applicator, the at least one paint applicator including a carrier element having a coating agent supply the coating agent supply widening in a direction of paint flow, the carrier element including a degassing opening, the degassing opening in a direction against the paint flow, the at least one paint applicator being supplied by a first paint line, the at least one paint applicator including a plurality of coating agent nozzles, the coating agent nozzles being arranged in a row, the coating agent nozzles deliver droplets of paint onto the motor vehicle body, and; at least one robot controller that controls the at least one robot to guide the at least one paint applicator along a predefined coating agent path over the motor vehicle body.
2. The painting installation of claim 1 wherein the plurality of coating agent nozzles are uniform in size.
3. The painting installation as in claim 1 further comprising a colour changer fed by a plurality of paint lines and including an outlet connected to the first paint line.
4. The painting installation as in claim 3 further comprising a second colour changer that supplies low runner colours.
5. The painting installation as in claim 1 further including a oscillation generator that forms the droplets of paint.
6. The painting installation as in claim 1 wherein the at least one paint applicator includes a second row of nozzles.
7. The painting installation as in claim 1 wherein the plurality of coating agent nozzles have a deviation in size.
8. The painting installation as in claim 1 wherein the plurality of coating agent nozzles are round.
9. The painting installation as in claim 8 wherein the plurality of coating agent nozzles include a diameter between 10 microns and 80 microns.
10. A painting installation as in claim 1 wherein the at least one paint applicator includes a nozzle plate; wherein the plurality of coating agent nozzles are formed in the nozzle plate.
11. A painting installation as in claim 1 wherein the at least one paint applicator further comprising at least one electrode to electrostatically charge the paint droplets.
12. A painting installation as in claim 1 wherein the degassing opening is located at a widened portion of the coating agent supply.
Description
(1) The figures show as follows:
(2) FIG. 1: a cross-section view through a conventional painting installation for painting motor vehicle body components.
(3) FIG. 2: a cross-section view of a painting installation for painting motor vehicle body components with application apparatuses,
(4) FIG. 3A: an application apparatus with a colour changer and the associated coating agent supply,
(5) FIG. 3B: an application apparatus with at least two or more direct coating agent supply lines and a separate colour changer,
(6) FIG. 4A: a row of nozzles (part of a carrier element or a nozzle plate) with a plurality of coating agent nozzles and an assigned colour changer,
(7) FIG. 4B: a group of several, for example four, application apparatuses with at least two or more, for example four, direct coating agent supply lines and a separate colour changer,
(8) FIG. 5: a plurality of rows of nozzles for the application apparatus which are commonly supplied, with the coating agent to be applied, via a mixer with an attached colour changer and supply lines for a two or multi-component coating agent,
(9) FIG. 6: a plurality of rows of nozzles for the application apparatus which are commonly supplied via a single coating agent supply line to which a mixer with supply lines for a two or multi-component coating agent is assigned,
(10) FIG. 7: a nozzle arrangement in an application apparatus,
(11) FIG. 8: an alternative nozzle arrangement in the application apparatus with smaller coating agent nozzles,
(12) FIG. 9: an alternative arrangement of the coating agent nozzles in the application apparatus, wherein the coating agent nozzles have different nozzle sizes,
(13) FIG. 10: a variation of FIG. 9, wherein the nozzle rows with the larger coating agent nozzles are arranged offset with regard to each other
(14) FIG. 11: an application apparatus arrangement with a plurality of freely movable and/or rotatable application apparatuses for adaptation to curved component surfaces,
(15) FIG. 12: a schematic view of a coating device according to the invention with a multiple axis robot which guides an application apparatus and a sensor in order to position the application apparatus,
(16) FIG. 13: a schematic view of a coating device according to the invention in which several components are mixed to form a mixture, wherein the application apparatus then applies the mixture,
(17) FIG. 14: a schematic view of an application apparatus according to the invention with a cladding flow nozzle,
(18) FIG. 15: a schematic view of an application apparatus which generates a trapezoidal layer thickness distribution
(19) FIG. 16: a schematic view of a coating device according to the invention in which numerous application apparatuses are mounted on a portal,
(20) FIGS. 17 and 18: variations of FIGS. 9 and 10 with a maximum packing density of the individual nozzles,
(21) FIGS. 19A to 19E: various forms of longitudinal sections of coating agent nozzles,
(22) FIG. 20A: a schematic view of a nozzle arrangement for an application apparatus,
(23) FIG. 20B: a schematic view of a layer thickness distribution generated by the nozzle arrangement according to FIG. 20A,
(24) FIG. 20C: a schematic view of another nozzle arrangement for an application apparatus,
(25) FIG. 21A: a schematic view of yet another nozzle arrangement for an application apparatus,
(26) FIG. 21B: a schematic view of a layer thickness distribution generated by the nozzle arrangement according to FIG. 21A,
(27) FIG. 21C: three overlapping trapezoidal layer thickness distributions with the resulting overall layer thickness distribution similar to FIG. 15,
(28) FIG. 21D: a sharp-edged layer thickness distribution, generated by means of at least one switched off applicator or switched off coating agent nozzle arrangement,
(29) FIG. 22A: a schematic view of a break up into droplets of an initially coherent coating agent jet, discharged by an application apparatus,
(30) FIG. 22B: a schematic view of a prior art atomization;
(31) FIG. 22C: a very simplified view of a break up into droplets of an initially coherent coating agent jet, discharged by an application apparatus,
(32) FIGS. 23A to 23E: schematic views of different coherent coating agent jets with their respective spray jet cross-section,
(33) FIGS. 24A, 25A, 26A: schematic views of different application apparatuses with a coating agent having no oscillation applied to it,
(34) FIGS. 24B, 25B, 26B: schematic views of different application apparatus with a coating agent having an oscillation applied to it,
(35) FIGS. 27A, 27B, 27C: schematic views of cross-sections of various application apparatuses, in particular in the area of the carrier element or the nozzle plate,
(36) FIG. 28: a very simplified application apparatus,
(37) FIG. 29: a multiplicity, for example three, application apparatuses with two coating agent supply lines separated from each other with a respective colour changer,
(38) FIG. 30: an application apparatus with two coating agent supply lines separated from each other with a respective apparatus changer,
(39) FIG. 31: an application apparatus with two coating agent supply lines and integrated switch-over device.
(40) The cross-section view in FIG. 2 shows a painting installation that partially corresponds with the conventional painting installation shown in FIG. 1, so that, in order to avoid repetition, reference is made to the above description, wherein the same reference numerals are used for corresponding details.
(41) A special feature of the painting installation disclosed herein is that the painting robots 3, 4 do not have rotary atomizers as application devices, but rather application apparatuses 8, 9, each of which comprises an oscillation generator SE and which can be designated as droplet generator or application head. The respective application apparatus 8, 9 has a much higher application efficiency, e.g., over 90% higher, than rotary atomizers. In this way it is possible that less overspray is created because the application apparatuses 8, 9 are capable of forming coating agent droplets, e.g., paint droplets with essentially an equal size and with an essentially discrete or homogeneous droplet distribution. The application apparatuses 8, 9 may apply and discharge the coating agent essentially continuously during a coating operation.
(42) The application apparatuses 8, 9 with the oscillation generators SE apply an oscillation and/or an instability to the coating agent to form coating agent droplets and/or to allow the coating agent to break up into droplets. There are, in particular, initially coherent or continuous coating agent jets coming out of the coating agent nozzles or the application apparatuses 8, 9 which then break up into droplets on the way to the component or between the application apparatuses 8, 9 or the coating agent nozzles and the component.
(43) Application or formation of droplets of essentially the same size and/or of an essentially homogeneous droplet distribution offers the advantage, on the one hand, that one can dispense with the washing out system 7 for the conventional painting installation according to FIG. 1.
(44) Instead, the painting installation of FIG. 2 has an air extractor 10 under the painting cabin 2 which extracts the cabin air downwards from the painting cabin 2 through a filter ceiling 11. Here, the filter ceiling 11 filters the small amount of overspray out of the cabin air without the wash-out 7 being required as in the conventional painting installation. Items such as a cartridge filters, fleeces, filter mats, cardboard filters, etc. can be used as filter elements.
(45) FIG. 3A shows an application apparatus 8 (9) which is supplied by a colour changer 13 with the coating agent to be applied. On the input side the colour changer 13 is connected to a plurality of coating agent supply lines (colour 1 to colour 7) from which the colour changer 13 can select one for supplying coating agent to the application apparatus 8 (9).
(46) FIG. 3B shows an application apparatus 8 (9) which is directly supplied by at least two, for example three, coating agent supply lines (colour 5 to colour 7) with the coating agent to be applied (so-called High-Runners) and a separate colour changer 13.
(47) On the input side the colour changer 13 can, for example, be connected to four coating agent supply lines (colour 1 to colour 4) from which the colour changer 13 can select one for supplying coating agent to the application apparatus 8.
(48) The coating agent supply lines may be directly connected for direct supply of the application apparatus 8 with the application apparatus 8, wherein, for example, every coating agent can be assigned to a separate dosing device (e.g. a dosing pump) which advantageously does not have to be flushed out.
(49) FIG. 4A shows a group of coating agent nozzles 16.1-16.5, which are commonly connected to the outlet of a colour changer 17 and therefore apply the same coating agent during operation.
(50) On the input side the colour changer 17 is connected to a multiplicity, for example, seven, coating agent supply lines. The five coating agent nozzles shown are an example of an arrangement of a plurality of coating agent nozzles.
(51) FIG. 4B shows a modification of the exemplary embodiments in FIGS. 3B and 4A, so that reference is made to the above description to avoid repetition, wherein the same reference numerals are used for corresponding details.
(52) FIG. 4B in particular shows a group of two or more, e.g., four, application apparatuses 8 with two or more, e.g., four, direct coating agent supply lines (colour 5 to colour 8) and a separate colour changer 17.
(53) The respective application apparatuses 8 may be commonly connected to the outlet of the colour changer 17 and/or to the coating agent supply lines (for so-called High-Runners) and therefore apply the same coating agent during operation.
(54) FIG. 5 shows a further exemplary embodiment of a nozzle arrangement in the application apparatuses 8, 9, wherein several, e.g. four, nozzle rows 28.1-28.4 are shown here, each of which has numerous coating agent nozzles 29. Here, all the coating agent nozzles 29 and all the coating agent rows 28.1-28.4 are commonly supplied with the same coating agent from a mixer 31 and a colour changer 30.
(55) On the input side the colour changer 30 is connected with a plurality of coating agents (for example paints or special paints S1 to S3) or a plurality of coating agent supply lines and the mixer 31. The mixer 31 is connected on the input side with a plurality of coating agents, e.g., at least two components (K1, K2) for a two or multi-component paint (for example basic paint and hardener).
(56) The example embodiment as shown in FIG. 6 partially corresponds with the above-described exemplary embodiment illustrated in FIG. 5, so that reference is made to the above description to avoid repetition, the same reference numerals being used for corresponding details.
(57) A feature of this exemplary embodiment is that all coating agent nozzles 29 in all rows of nozzles 28.1-28.4 are connected with a common coating agent supply line 31 via which the same coating agent is fed and to which a mixer with feed lines (not shown in FIG. 6) for a first component and at least one second component is assigned (for example basic paint and hardener).
(58) FIG. 7 shows a nozzle arrangement 34 for the application apparatuses 8, 9 of the painting installation according to the invention, wherein the arrow indicates the direction of advance of the application apparatuses 8, 9, i.e. the direction of the pressure.
(59) From the drawing, it can be seen that the nozzle arrangement 34 has several nozzle rows 35.1-35.7 each of which comprise several coating agent nozzles 36.
(60) Within the entire nozzle arrangement 34 the coating agent nozzles 36 here have a nozzle opening of uniform size.
(61) The adjacent nozzle rows 35.1-35.7 are offset with regard to each other in the longitudinal direction by half the width of a nozzle, which allows a maximum packing density of the coating agent nozzles 36 within the nozzle arrangement 34.
(62) FIG. 8 shows a derivation of a nozzle arrangement 34 which corresponds to a great extent with the nozzle arrangement described above and shown in FIG. 7, so that to avoid repetition reference is made to the above description.
(63) A feature of this exemplary embodiment is that the individual nozzles 36 have a substantially smaller nozzle size.
(64) A further feature of this exemplary embodiment is that the adjacent nozzle rows are not offset with regard to each other.
(65) FIG. 9 shows a further exemplary embodiment of a nozzle arrangement 37 with five parallel nozzle rows 38.1-38.5 with relative large nozzle openings and four nozzle rows 39.1-39.4 with relatively small nozzle openings.
(66) The exemplary embodiment in accordance with FIG. 10 largely corresponds with the exemplary embodiment in accordance with FIG. 9 described above, so that to avoid repetition reference is made to the above description, wherein the same reference numerals being used for corresponding details.
(67) A feature of this exemplary embodiment is that the nozzle rows 38.1-38.5 with the larger nozzle openings are offset with regard to each other in the longitudinal direction by half the width of a nozzle.
(68) FIG. 11 shows an application apparatus arrangement 46 with a total of four application apparatuses 47-50 which are rotatable with regard to each other or aligned appropriately to the surface of a, for example, curved component in order to allow better adaptation to the surface of a e.g. curved component 51.
(69) In a very simplified form FIG. 12 shows a coating device with a multiple axis robot 58 which moves an application apparatus 59 along predefined coating agent paths over a component surface 60, wherein the robot 58 is operated by a robot controller 61 and can have a wrist. The robot controller 61 controls the robot 58 in such a way that the application apparatus 59 is guided along predefined coating agent paths over the component surface 60 wherein the coating agent paths lie adjacent to each other in a meandering pattern.
(70) A feature is that an optical sensor 62 is also attached to the application apparatus 59 which during operation detects the position and course of the previous coating agent path so that the current coating agent path can be exactly aligned with regard to the previous coating agent path.
(71) FIG. 13 shows in a very simplified form a variant of a coating device according to the invention with several, e.g., three, separate coating agent supply lines 63-65, which each supply one component of the coating agent to be applied.
(72) On the output side the coating agent supply lines 63-65 are connected to a mixer 66 which mixes the individual components into a coating agent mixture which is then supplied to an application apparatus 67. Mixing of the various components of the coating agent thus takes place before application by the application apparatus 67. The component 3 shown in FIG. 13 is optional.
(73) FIG. 14 shows a schematic view of an application apparatus 69 which applies an oscillation to the coating agent or a coherent coating agent jet 70. The coating agent or a coherent coating agent jet 70 is discharged out of the coating agent nozzle 72 which breaks up between the coating agent nozzle 72 and the component surface 71 into droplets 70. The arrows F show schematically that the coating agent or the coating agent jet 70 is applied with the oscillation, frequency and/or instability at the coating agent nozzle 72 or by means of the carrier element comprising the coating agent nozzle 72.
(74) Furthermore, the application apparatus 69 has at least one, and possibly a plurality, of cladding flow nozzles 73 which surround the coating agent nozzle 72 or a plurality of coating agent nozzles, for example in a ring-shaped manner, and discharge a ring-shaped cladding flow which surrounds the individual coating agent droplets 70.
(75) On the one hand this serves to delimit the individual coating agent droplets 70 and to protect the discharged coating agent and/or the discharged coating agent droplets 70.
(76) On the other hand the cladding flow discharged from the cladding flow nozzle 73 directs the coating agent droplets 70 in the direction of the component surface 71 and thereby improves the application efficiency.
(77) In a similar way also one or more guide jet nozzles, in particular guide air nozzles, can be provided, the guide air from which is provided to protect the discharged coating agent and/or the discharged coating agent droplets or to form them and/or to guide them. Also, further function nozzles can be provided for discharge of certain media.
(78) In a very simplified form FIG. 15 shows an application apparatus 74 during the application of two adjacent paint paths, wherein the position of the application apparatus 74 in the current paint path is shown without an apostrophe, while the position of the application apparatus 74 in the previous painting path is shown with an apostrophe.
(79) The application apparatus 74 has a plurality of coating agent nozzles 75 arranged next to each other transversely to the path direction, wherein the outer section of application apparatus 74 discharges less coating agent than the inner section. As a result the application apparatus 74 achieves a trapezoidal layer thickness distribution 76 on the component surface. This is advantageous as the trapezoidal layer thickness distribution 76 is then superimposed on the also trapezoidal layer thickness distribution 76 of the previous paint path which leads to a constant layer thickness. FIGS. 20A and 21A show possible designs of a coating agent nozzle arrangement or a carrier element with coating agent nozzles (nozzle plate), in order to realize the principle of layer thickness distribution.
(80) In a simplified form FIG. 16 shows a coating device according to the invention in which the components 77 to be coated are transported along linear conveyor path 78 through a painting cabin, which is known from the prior art and does not therefore need to be described in more detail.
(81) A portal 79 spans the conveyor path 78 wherein attached to the portal are numerous application apparatuses 80 which are directed at the components 77 on the conveyor path 78 and coat these with a coating agent.
(82) FIG. 17 shows a derivation of FIG. 10, so that to avoid repetition reference is made to the above description, wherein the same reference numerals being used for corresponding details.
(83) A feature of this exemplary embodiment is the much greater packing density of the individual coating agent nozzles.
(84) FIG. 18 shows a derivation of FIG. 17, so that to avoid repetition reference is made to the above description, wherein the same reference numerals being used for corresponding details.
(85) Here too, the feature is that the packing density of the individual coating agent nozzles is much greater.
(86) FIGS. 19A to 19E show various forms of longitudinal sections of coating agent nozzles. The longitudinal sections shown in FIGS. 19A to 19E can be round nozzles or slit nozzles.
(87) FIG. 19A shows a cylindrical nozzle form or a constant nozzle form.
(88) FIG. 19B shows an at least preferably twice widening and again narrowing nozzle form, in particular with at least two bulges 81 and at least one constriction 82, which is arranged between the at least two bulges 81, and preferably a constant or cylindrical inlet and a constant or cylindrical outlet.
(89) FIG. 19C shows a nozzle form with a conical tapering or narrowing inlet and cylindrical or constant outlet.
(90) FIG. 19D shows a nozzle form with a cylindrical or constant inlet and a preferably conically widening outlet.
(91) FIG. 19E shows a Venturi or Laval nozzle.
(92) The cross sections of the nozzle forms shown in FIGS. 19A to 19E may be circular (e.g., round nozzles), but can also be rectangular (e.g., slit nozzles). With a constant nozzle form or constant inlet and/or outlet one means is an essentially unchanging cross section in the longitudinal direction of the coating agent nozzle.
(93) The number and arrangement of the nozzles of the application apparatuses 8, 9 can be formed in such a way that the surfaces to be coated are coated uniformly, with fill coverage and homogeneously. To do this, the respective application apparatus 8, 9 can be fitted both with nozzles of one size and nozzle form but also with differently sized nozzles or different nozzle forms. The differently sized nozzles can be evenly distributed or grouped together in certain areas or forms. Through respective arrangement of the nozzles of an application apparatus 8, 9 it is possible to generate, for example, an ideal layer thickness distribution during the coating operation.
(94) FIG. 20A shows a schematic representation of a coating agent nozzle arrangement BA which comprises a plurality of coating agent nozzles (shown schematically as black points). The coating agent nozzle arrangement BA is provided in such a way that a layer thickness distribution with an essentially Gaussian normal distribution is formed. The coating agent nozzle arrangement BA is, for example, provided in such a way that its coating agent nozzles form an outline U according to an essentially Gaussian normal distribution curve and are preferably distributed over the section U (the surface under the Gaussian curve), which is surrounded by the outline U. Every further nozzle arrangement suitable for overlapping (e.g. a trapezoid or triangular form) can be generated. The arrow shown in FIG. 20A shows the direction of advance of the application apparatus 8.
(95) FIG. 20B shows a schematic representation of a cross-section through the layer thickness distribution, which is created by a coating agent nozzle arrangement BA according to FIG. 20A. The cross-section is limited to an essentially Gaussian normal distribution curve which essentially matches the outline U in FIG. 20A.
(96) FIG. 20C shows a schematic representation of another coating agent nozzle arrangement BA which also comprises a plurality of coating agent nozzles (shown schematically as black points). The coating agent nozzles create a rectangular outline U and are preferably distributed over the section U (rectangular surface), which is surrounded by the outline U, for example in a matrix-shaped manner. Such an arrangement is advantageous to allow sharp-edged coating.
(97) Furthermore, a coating agent nozzle arrangement (not shown) is possible for which the coating agent nozzles create a circular outline and are distributed over a circular surface. There are also further arrangements possible.
(98) FIG. 21A shows a schematic representation of three coating agent nozzle arrangements BA1, BA2 and BA3 which are actuatable or adjustable independently of one another (for example controllable or variable). Each of the coating agent nozzle arrangements BA1, BA2 and BA3 has a plurality of coating agent nozzles (shown schematically as black points). The outer coating agent nozzle arrangement BA1 is provided in such a way that its coating agent nozzles create a triangular outline and may be distributed over the section which is surrounded by the triangular outline. The middle coating agent nozzle arrangement BA2 is provided in such a way that its coating agent nozzles create a rectangular outline and may be distributed over the section which is surrounded by the rectangular outline. The other outer coating agent nozzle arrangement BA3 is provided in such a way that its coating agent nozzles create a triangular outline and may be distributed over the section which is surrounded by the triangular outline. The three coating agent nozzle arrangements BA1, BA2 and BA3 are provided in such a way that their coating agent nozzles overall create a trapezoid outline. The middle coating agent nozzle arrangement BA2 is essentially provided for surface coating wherein the two outer coating agent nozzle arrangements BA1, BA3 are essentially provided for overlapping coating. The outer coating agent nozzle arrangements BA1, BA3 can also have every other nozzle distribution adapted for overlapping.
(99) FIG. 21B is a schematic view of a cross-section through the layer thickness distribution which is created by the three coating agent nozzle arrangements BA1, BA2, BA3 according to FIG. 21A when all three coating agent nozzle arrangements BA1, BA2, BA3 apply. The cross-section of the layer thickness distribution is trapezoid.
(100) FIG. 21C, in a similar way to FIG. 15, shows three adjacing painting paths, each of which has a trapezoid layer thickness distribution 76, 76 and 76. This is advantageous because the trapezoid layer thickness distributions can be overlapped appropriately which leads to and essentially constant layer thickness. The line marked with the reference numeral 83 shows the resulting layer thickness. As mentioned the trapezoid formation is only an exemplary formation and can be any other adapted distribution concerning overlapping.
(101) A further advantage with regard to the coating agent nozzle arrangements BA1, BA2 and BA3 shown in FIG. 21A is that particularly the outer coating agent nozzle arrangements BA1 and BA3 can be controlled, for example switched on and switched off. In this way it is possible, as shown in FIG. 21D, to achieve sharp-edged coating, as shown by the edge marked with the reference numeral 84. FIG. 21D shows a cross-section through a layer thickness distribution which is created by the middle coating agent nozzle arrangement BA2 and the outer coating agent nozzle arrangement BA3 shown in FIG. 21A on the right, wherein the coating agent nozzle arrangement BA1 shown in FIG. 21A on the left is switched off and therefore does not apply coating agent.
(102) It is, however, also possible that an application apparatus scans on a line created by the individual nozzles along the surface to be coated or is moved during application of a line over the surface to be coated so that no overlappings are necessary.
(103) A break up into droplets is shown schematically in FIG. 22A. FIG. 22A shows a coherent coating agent jet 70 discharged from a coating agent nozzle of the application apparatus 8 (9) and, in particular, how the coherent, discharged coating agent jet 70 breaks up into droplets 70 due to the coupled in oscillation and/or instability, possibly based on the so-called Rayleigh instability or the so-called Rayleigh disintegration. The application apparatus 8 (9) applies droplets 70, essentially equal in size, wherein an essentially discrete or essentially homogeneous droplet distribution is achieved, as one can see in FIG. 22A. The arrows F show schematically that the coating agent or the coating agent jet 70 is, at the coating agent nozzle or by means of the carrier element comprising the coating agent nozzle, applied with the oscillation, frequency and/or instability.
(104) Another possible droplet break up is shown in a very simplified form in FIG. 22C. FIG. 22C shows a coherent essentially flat coating agent jet discharged from a coating agent nozzle of the application apparatus 8 (9) (for example a coating agent sheet or a coating agent lamella; for simplicity this is also given the reference numeral 70), which breaks up into droplets due to the coupled in oscillation and/or instability (for simplicity also given the reference numeral 70).
(105) The flat coherent coating agent jet 70 breaks up into a plurality of droplet producing (essentially one-dimensional) coating agent jets. Also the arrows F in FIG. 22C show schematically that the coating agent or the coating agent jet 70 is, at the coating agent nozzle or by means of the carrier element comprising the coating agent nozzle, applied with the oscillation, frequency and/or instability.
(106) FIG. 22B, on the other hand, shows a schematic atomization of coating agent according to the prior art. One can recognize the different sized coating agent droplets (for simplicity also given the reference numeral 70) and the non-homogeneous droplet distribution which contributes to an increased overspray.
(107) The structure, the principle and/or the functionality of such droplet generators is, for example, known from DE 44 41 553 C2, DE 10 2006 012 389 A1 and the publications Atomization and Sprays, vol. 7, pp. 43-75, 1997, METHODS AND TOOLS FOR ADVANCED FUEL SPRAY PRODUCTION AND INVESTIGATION, G. Brenn, F. Durst, D. Trimis, and M. Weclas and Atomization and Sprays, vol. 15, pp. 661-685, 2005, CONTROL OF SPRAY FORMATION BY VIBRATIONAL EXCITATION OF FLAT-FAN AND CONICAL LIQUID SHEETS, Gnter Brenn, Zeljiko Prebeg and Dirk Rensink, Alexander L. Yarin, the disclosures of which should be added in full to this disclosure, and accordingly are hereby incorporated by reference herein in their entireties.
(108) It is possible that the respective oscillation generator SE couples the oscillation and/or the instability preferably via the housing of the application apparatus 8 (9) into the coating agent. For this purpose the oscillation generator SE can, for example, be arranged as a quartz oscillator on the outside of the respective housing of the application apparatuses 8, 9 or at least provided in order to apply oscillation to this section, which is shown in FIG. 28 in a very simplified form. It is, however, possible, as an alternative or additionally, that the oscillation generator is integrated into the inner side of the respective application apparatus 8, 9 and applies the coating agent with the oscillation and/or the instability, for example, by sound, mechanically by means of physical contacting or by means of a piezo element, in order to allow droplets to form, which is shown in FIG. 28 in a very simplified form by the dashed lined rectangle marked with SE.
(109) The coherent or continuous coating agent jet which should break up into droplets can be made available in a number of ways. FIGS. 23A to 23E schematically show various coating agent jets (for simplicity all also given the reference numeral 70), which are discharged from a coating agent nozzle (not shown in FIGS. 23A to 23E), and respective spray jet cross-sections 70.
(110) FIG. 23A shows an (essentially one-dimensional) full jet which can be influenced according to the invention so that it breaks up into droplets.
(111) FIG. 23B shows an essentially planar jet (for example a coating agent sheet or a coating agent lamella) in the form of a flat and/or a layered jet or a triangular jet, which can be influenced according to the invention so that it breaks up into droplets and/or it breaks up into a plurality of coating agent jets (preferably essentially one-dimensional) which break up into droplets.
(112) FIG. 23C shows a hollow-cone jet, FIG. 23D a full-cone jet and FIG. 23E a hollow-cylindrical jet, which also can be influenced according to the invention so that they break up into droplets and/or they break up into a plurality of coating agent jets (possibly essentially one-dimensional) which break up into droplets.
(113) It is also possible not only to generate circular but also essentially rectangular spray jet cross-sections.
(114) FIGS. 24A and 24B each show an application apparatus 8 (9) in a very simplified form. Each application apparatus 8 (9) has a plurality of coating agent nozzles in one level.
(115) FIGS. 25A and 25B each show another application apparatus 8 (9) in a very simplified form. Each application apparatus 8 (9) has a gap or slit nozzle.
(116) FIGS. 26A and 26B each show yet another application apparatus 8 (9) in a very simplified form. Each application apparatus 8 (9) has a circular or conical nozzle.
(117) For the application apparatuses shown in FIGS. 24A, 25A and 26A there is no application of an oscillation and/or an instability to the coating agent or coating agent jet 85 which is why the coating agent jets 85 do not break up into droplets.
(118) For the application apparatuses shown in FIGS. 24B, 25B and 26B there is, on the other hand, application of an oscillation and/or an instability to the coating agent or coating agent jet 86 which is why the coating agent jets 86 break up into droplets. In FIG. 25B and FIG. 26B there should actually be significantly more droplet jets 86 displayed, which were, however, ignored because they would have no longer been recognizable.
(119) FIGS. 27A, 27B and 27C show schematic views of cross-sections of various application apparatuses, in particular in the area of a carrier element for a nozzle plate and/or a plurality of coating agent nozzles. A carrier element 89 and a coating agent supply 87 which opens out into the carrier element 89 can particularly be seen. The coating agent supply 87 preferably widens in the direction of flow of the coating agent (see arrow in FIG. 27A) or towards at least one coating agent nozzle, in order to supply one or more coating agent nozzles with coating agent.
(120) The application apparatus can have at least one degassing outlet pipe and/or a return line connection or a degassing opening 88 as shown in FIGS. 27B and 27C. The degassing outlet pipe or the return line connection 88 in FIG. 27B is arranged on the coating agent supply 87 or at least adjacent to this, whereas in FIG. 27C the degassing outlet pipe or the return line connection 88 can be arranged adjacent to the coating agent nozzles, adjacent to the carrier element or on the carrier element.
(121) FIG. 28, which was already mentioned above, shows the application apparatus 8 (9) which generates a plurality of initially coherent coating agent jets 70, which break up into droplets 70 due to the oscillation and/or the instability generated by the oscillation generator SE or SE. Furthermore, the application apparatus 8 shown in FIG. 28 comprises a system for electrostatic coating agent charging with a high voltage, e.g., an electrostatic coating agent charging system for external charging AA of the (discharged) coating agent. The coating agent charging system AA can comprise a plurality of finger electrodes or an electrode ring, in which a multiplicity of electrodes is embedded. The finger electrodes, the electrode ring and/or the electrodes E are preferably arranged outside the application apparatus housing 8, wherein, in particular, the electrodes E are evenly spaced around the application apparatus 8 in order to charge the coating agent discharged from the at least one coating agent nozzle.
(122) It is also possible that an electrostatic coating agent charging system for direct charging DA of the (not yet discharged) coating agent is provided, which is indicated in FIG. 28 by the dotted line rectangular marked with the reference numeral DA. In doing so the coating agent, which was not yet discharged, passes by at least one electrode integrated on the inside of the application apparatus 8, to be charged. The coating agent charging system AA, DA is configured and arranged in order to achieve an improved separation, an improved coating agent yield and/or an improved application efficiency.
(123) FIG. 29 shows a plurality of, e.g., three, application apparatuses 8 with a plurality of, e.g., two, coating agent supply lines, completely separated from each other, each with its respective colour changer A, B, so that while the one colour changer or the one coating agent supply line leads the coating agent to the application apparatuses 8, the other colour changer or the other coating agent supply line can be prepared. It is therefore applied either via the first colour changer A or via the second colour changer B. A return line RFA, RFB can respectively be attached to the coating agent supply lines between the application apparatuses 8 and the respective colour changer A, B.
(124) FIG. 30 shows an application apparatus 8 with two coating agent supply lines, completely separated from each other, each with its respective colour changer A, B, so that while the one colour changer or the one coating agent supply line leads the coating agent to the application apparatuses 8, the other colour changer or the other coating agent supply line can be prepared. A return line RFA, RFB can respectively be attached to the coating agent supply lines between the application apparatus 8 and the respective colour changer A, B. Also here it is applied either via the first colour changer A or via the second colour changer B.
(125) FIG. 31 shows an application apparatus 8 with two separated coating agent supply lines and an integrated switch-over device to set which of the multiplicity of coating agent supply lines and/or which of the multiplicity of colour changers A, B the coating agent will be discharged from. The two coating agent supply lines are completely separated from each other, open out into the application apparatus 8 and each has a colour changer A, B. In a similar way to the exemplary embodiments according to FIGS. 29 and 30, also here it is possible to provide return lines RFA, RFB between the respective colour changer A, B and the application apparatus 8, wherein also here it is applied either via the first colour changer A or via the second colour changer B.
(126) The above-mentioned preferred exemplary embodiments can be combined with each other. The invention is not limited to the exemplary embodiments described above. Instead, a plurality of variants and modifications are possible, which also make use of the concept of the invention and thus fall within the scope of protection.
