Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
  • B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
  • B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
  • B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/02—Spray pistols; Apparatus for discharge
  • B05B7/06—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane
  • B05B7/062—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet
  • B05B7/065—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet an inner gas outlet being surrounded by an annular adjacent liquid outlet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/16—Arrangements for controlling delivery; Arrangements for controlling the spray area for controlling the spray area
  • B05B12/18—Arrangements for controlling delivery; Arrangements for controlling the spray area for controlling the spray area using fluids, e.g. gas streams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
  • B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
  • B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
  • B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
  • B05B17/0623—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers coupled with a vibrating horn
  • B05B17/063—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers coupled with a vibrating horn having an internal channel for supplying the liquid or other fluent material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/02—Spray pistols; Apparatus for discharge
  • B05B7/06—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane
  • B05B7/062—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet
  • B05B7/066—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet with an inner liquid outlet surrounded by at least one annular gas outlet
  • B05B7/067—Spray pistols; Apparatus for discharge with at least one outlet orifice surrounding another approximately in the same plane with only one liquid outlet and at least one gas outlet with an inner liquid outlet surrounded by at least one annular gas outlet the liquid outlet being annular
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/02—Spray pistols; Apparatus for discharge
  • B05B7/08—Spray pistols; Apparatus for discharge with separate outlet orifices, e.g. to form parallel jets, i.e. the axis of the jets being parallel, to form intersecting jets, i.e. the axis of the jets converging but not necessarily intersecting at a point
  • B05B7/0807—Spray pistols; Apparatus for discharge with separate outlet orifices, e.g. to form parallel jets, i.e. the axis of the jets being parallel, to form intersecting jets, i.e. the axis of the jets converging but not necessarily intersecting at a point to form intersecting jets
  • B05B7/0815—Spray pistols; Apparatus for discharge with separate outlet orifices, e.g. to form parallel jets, i.e. the axis of the jets being parallel, to form intersecting jets, i.e. the axis of the jets converging but not necessarily intersecting at a point to form intersecting jets with at least one gas jet intersecting a jet constituted by a liquid or a mixture containing a liquid for controlling the shape of the latter
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/02—Spray pistols; Apparatus for discharge
  • B05B7/10—Spray pistols; Apparatus for discharge producing a swirling discharge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
  • B05B1/02—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape
  • B05B1/06—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shape in annular, tubular or hollow conical form
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
  • B05B15/50—Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter
  • B05B15/55—Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter using cleaning fluids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
  • B05B5/025—Discharge apparatus, e.g. electrostatic spray guns
  • B05B5/03—Discharge apparatus, e.g. electrostatic spray guns characterised by the use of gas, e.g. electrostatically assisted pneumatic spraying

Definitions

• the invention relates to a liquid coating sprayer on a part and a spray installation equipped with such a sprayer.
• the invention finds application in the field of coating parts.
• sprayers are often used in the automotive industry to coat paint bodies and developments have led to their use in sol-gel processes.
• Sol-gel processes make it possible, among other things, to form a mineral or organomineral layer without resorting to melting.
• These processes use a sol formulated from inorganic or hybrid precursors prepared in a solvent by means of a chemical treatment that may include, in particular, hydrolytic decomposition, a temperature variation, a hydrolysis decomposition or a pH variation.
• This sol is deposited in thin layers on the substrate to be coated and the solvent is evaporated so that the layer gels in a crystalline or amorphous layer, such as a layer of glass, ceramic or even glass ceramic.
• the deposition of the soil layer is made by known techniques of dipping or spin coating. However, these techniques are difficult to implement for large parts such as a windshield. This is why liquid coating sprays are an interesting alternative to these deposition techniques.
• the soil layer must be thin and uniform, with a high quality finish, which is difficult to achieve with conventional sprayers.
• Sprayers or "vortex" type spray guns are known to provide better spray stability. Indeed, these guns have the particularity that the jet of liquid is sheared externally by a high pressure air knife. This causes the jet of liquid in rotation about a central spraying axis, which improves the stability of the jet. However, the paint particles near the inner surface of the jet are subjected to less shear compared to those located at the periphery of the jet. The size of the droplets and their distribution are therefore not homogeneous within the jet, which causes a quality of finish that is not acceptable for applications such as the application of a coating of paint on a car body or a soil layer in a sol-gel process.
• an electrostatic sprayer comprising, in addition to a first ejection passage of an air knife surrounding the passage of the product, a second ejection passage of an internal air knife.
• the first passage is defined between a core and a nozzle of the sprayer, the core being disposed coaxially inside the nozzle.
• the inner and outer air knives pinch and refine the product blade. This nip results in a greater fineness of spray.
• the frictional forces that occur at the interface between the product blade and the two blades of air create disturbances within the product blade, which cause the formation of fine droplets by spraying. Spraying the paint with two blades of air provides a better quality of finish.
• the friction forces applied on both sides of the product blade are at the origin of a size and a distribution of the droplets which are more homogeneous within the product blade.
• the size of the droplets is not controlled, so that it is not possible to adapt the size of the droplets depending on the type of coating to be performed.
• the invention more particularly intends to remedy by proposing a sprayer making it possible to adapt the size of the sprayed droplets.
• the invention relates to a sprayer of a liquid coating product along a spray axis, comprising a first passage of a product blade, which is centered on the spray axis, and a second passage of ejection of an air space which coaxially surrounds the first passage.
• This sprayer further comprises a third ejection passage of another air gap which is arranged coaxially inside the first passage, a nozzle centered on the spray axis, and a core disposed coaxially inside. of the nozzle so that the first passage is defined between the core and the nozzle.
• the sprayer further comprises a vibrator which is able to vibrate at least the nozzle or the core.
• a sprayer may incorporate one or more of the following features, taken in any technically permissible combination:
• the third passage gives the other air gap a divergent direction, relative to the spray axis, in the direction of the spray.
• the second passage gives the air gap a divergent direction, relative to the spray axis, in the direction of the spray.
• At least one passage among the second passage and the third passage gives the air knife or the other air knife a helical direction with respect to the spray axis.
• the sprayer comprises a chamber in which open at least a first air inlet duct, in an axial direction, and at least a second air intake duct, in a direction orthoradial with respect to the axis of spray, and that feeds the second pass.
• the sprayer comprises a chamber which is fed by an air supply duct and air ejection holes which are fed by this chamber and which, in operation, feed the air space together.
• the vibrator uses ultrasonic technology.
• the core extends along the spray axis and beyond the nozzle, by a bowl.
• the bowl has a bell shape that diverges, relative to the spray axis, in the direction of the spray.
• the inside of the bowl is cleanable by injecting a rinse aid into the third pass.
• the invention also relates to a spraying installation of a liquid coating product on a workpiece, this installation comprising a containment enclosure, a product supply block, an electropneumatic control box, and at least one sprayer of the product.
• this installation comprising a containment enclosure, a product supply block, an electropneumatic control box, and at least one sprayer of the product.
• the sprayer of this installation is as described above.
• the installation comprises means for adjusting the air flow rate in the first duct and in the second duct.
• FIG. 1 is a schematic view of a spraying installation of a liquid coating product according to the invention
• FIG. 2 is a perspective view of a module of a sprayer according to the invention belonging to the installation of FIG. 1,
• FIG. 3 is a view on a larger scale of the frame III of FIG. 2;
• FIG. 4 is a view along the arrow IV of FIG.
• FIG. 5 is a section on a larger scale along the line V-V of FIG. 4;
• FIG. 6 is a smaller-scale section along the line VI-VI of FIG. 5;
• FIGS. 7 and 8 are sections on a larger scale along the lines VII-VII and VIII-VIII of FIG. 4;
• FIG. 9 is a side view of a sprayer according to a second embodiment of the invention.
• FIG. 10 is a view along the arrow X of FIG. 9,
• FIGS. 11 and 12 are sections on a larger scale, respectively along the lines XI-XI and XII-XII of FIG. 10,
• FIG. 13 is a partial section along line XIII-XIII in FIG. 10;
• FIG. 14 is a longitudinal section similar to FIG. 11 and on a smaller scale, of a sprayer according to a third embodiment of the invention.
• FIG. 15 is a section along line XV-XV of FIG. 14,
• FIG. 16 is a view similar to FIG. 10, for a sprayer according to a fourth embodiment of the invention.
• FIGS. 17 and 18 are sections along the lines XVII-XVII and XVIII-XVIII of FIG. 16, and
• FIG. 19 is a section on a larger scale along the line XIX-XIX of FIG. 16.
• FIG. 1 a plant 2 for spraying a liquid coating product on a workpiece.
• this liquid coating product is liquid paint.
• the installation 2 includes a containment 20 which cleans the environment in the workshops, to recover and completely recycle the paint that does not reach the part or parts to be treated.
• the installation 2 comprises a pipe not shown, to drain the paint remained inside from the containment 20 to the outside.
• This enclosure 20 prevents in addition to any external pollution and facilitates the transport of paint droplets.
• the parts 26 make a path in a direction perpendicular to the plane of Figure 1 and according to which several types of sprayer are installed.
• a water spray can be used to cool the shaping tools and a liquid paint sprayer can then be used to coat the part with a coat of paint.
• a single wide piece passes through the installation 2.
• a modular sprayer is a sprayer comprising several modules all fed by the same power line. In the following description is detailed only the sprayer 22 to the extent that the sprayers 22 and 24 are identical.
• the modular sprayer 22 comprises two modules 222 and 223 and a mother block
• the mother block 220 is a block that supplies, in paint and air, the modules 222 and 223 of the sprayer 22. In practice, a spray assembly can contain up to five modules. Thus, two spray assemblies can have ten modules, which can spray paint on a piece of width equal to about 1 meter.
• the mother block 220 is connected by pipes 28 to a paint and air supply block. Furthermore, the mother block 220 is also connected by electric cables 21 to a high voltage production unit 23 whose function is detailed below.
• the high voltage production unit 23 and the paint and air supply unit 25 are each connected to an electropneumatic control box 27.
• the installation 2 further comprises a paint and air flow control system, not shown in Figure 1 but which is located upstream of the paint and air supply block.
• the flow control system reduces paint consumption.
• the module 222 of the sprayer 22 is shown alone in Figure 2, this module 222 is a part of revolution about an axis Z222 which is a spray axis of the paint.
• the terms “axial” or “axially” refer to a direction parallel to the axis Z222
• the terms “orthoradial” or “tangentially” refer to a direction orthoradial to the axis Z222
• c that is, a direction tangential to a circle centered on the Z222 axis
• the terms “high”, “Bottom”, “top” and “bottom” should be interpreted with respect to the Z222 axis, knowing that the direction from bottom to top represents the direction of ejection of the paint.
• the terms “inside” and “outside” should be interpreted in terms of a radial direction to the Z222 axis.
• This module 222 comprises an outer cover 1 which is hollow and symmetrical about the axis Z222 and within which is arranged coaxially a nozzle 3 which is hollow.
• a core 5 is disposed coaxially inside the nozzle 3.
• the nozzle 3 and the core 5 are also globally symmetrical parts around the Z222 axis.
• S3 and S5 denote the outer axial surfaces of the upper end of the nozzle 3 and e of the core 5.
• the surfaces S3 and S5 are flush.
• the nozzle 3 and the core 5 each protrude from the cover 1, so that the upper end of the cover 1 does not flush with the surfaces S3 and S5.
• the nozzle 3 and the core 5 delimit between them a generally tubular volume which represents a first passage P1 of the paint at the output of the module 222 of the sprayer 22.
• the first passage P1 is centered on the spraying axis Z222.
• the nozzle 3 defines, with the hood 1, a second passage P2 through which air circulates.
• holes 9 dug in the core 5 form a third passage P3 of air.
• This passage P3 may also have an annular section in a plane perpendicular to the axis Z222.
• the passages P1 and P2 have a cross-section, that is to say, perpendicular to the axis Z222, in the form of a ring, so that the passages P1 and P2 form annular passage sections that are concentric with respect to the Z222 axis when looking in the direction of the Z222 axis, while the passage P3 is a set of disjoint holes which are regularly distributed around the Z22 axis.
• the paint passes through the first passage P1 and forms a paint strip L1 which is generally tubular and centered on the spray axis Z222.
• the second passage P2 is traversed by air to form a first air gap L2 which is also tubular in geometry centered on the axis Z222 and which surrounds the paint blade L1.
• the holes 9 forming the third passage P3 conform a second air gap L3 which is generally of frustoconical geometry centered on the axis Z222, which is surrounded by the paint blade L1 and which diverges in the direction of spraying with respect to the Z222 axis.
• the air knife L2 is an external air jet, while the air knife L3 is an internal air jet relative to the paint blade L1.
• the module 222 comprises a base 4 which delimits air and paint connections and which supports the nozzle 3 and the core 5.
• a skirt 6 is disposed coaxially inside the cover 1.
• This skirt 6 is generally rotationally symmetrical around the axis Z222 and comprises a first portion 6A which encloses an upper portion of the base 4, a second portion 6B which surrounds a lower portion of the nozzle 3 and a third portion 6C connecting the the first part 6A with the second part 6B, this third part resting on the base 4.
• the first part 6 A of the skirt 6 has a rounded upper edge 6D, on which the hood 1 rests.
• the hood 1 comprises a beveled relief 1D which is adapted to bear against the upper edge of the portion 6A of the skirt 6.
• the connectors each feed a duct for passage of paint or air, among which the outlet orifice of a duct 7 makes it possible to form the air gap L3 at the outlet of the core 5, Outlets of the ducts 8 and 15 together form the air knife L2 and the outlet of a duct 17 forms the paint blade L1.
• the ducts 7, 15 and 17 pass through the base 4 while the duct 8 is defined between the cover 1 and the lower part 6A of the skirt 6.
• the core 5 has an internal cavity, or internal volume V5, which extends longitudinally along the axis Z222. This cavity V5 communicates with the duct 7 for air passage into the module 222 of the sprayer 22. Moreover, the core 5 comprises, at its upper end, the holes 9 of air passage. These holes 9 extend from the cavity V5 to the upper surface of the core 5, so that a flow F3 of air circulation in the passage P3 first passes through the conduit 7, then the cavity V5 and finally the holes 9 before being ejected from the core 5 to form the blade L3.
• the first air gap L2 is formed within the module 222 in a chamber
• holes 1 1 also open into the room V10. These holes 1 1 pass through the lower part 6A of the skirt 6 and connect the passage duct 8 to the chamber V10. Although they are visible in the background, two holes 1 1 are shown in dashed lines in Figure 5 to show the passage of air to the chamber V10. These holes 1 1 extend in a generally orthoradial direction with respect to the Z222 axis.
• the V10 chamber is therefore a mixing chamber of the air arriving holes 1 1 and 13 holes. This mixture results, within the V10 chamber, a vortex, which is at the origin of the "vortex" created output 222. The air then escapes upwards, between the hood 1 and the nozzle 3. However, the hood 1 has a high portion converging towards the Z222 axis. In other words, an internal bore S1 of this upper end portion is frustoconical and converges towards the central axis Z222.
• the air circulating in the passage P2 forms an air gap L2 which progressively deviates, or diverges from the spray axis Z222 in the direction of the spray. This implies that the air gap L2 causes the surrounding air of the paint jet to rotate around the axis Z222 and the paint jet L1 is sheared externally.
• the mixture of the air arriving from the holes 1 1 and 13 forms an air knife L 2 which has a generally helical direction F 2.
• the air knife L2 is ejected with a direction F2 which comprises an axial component F2b, which is created by the holes 13 and a component F2a orthoradial to the axis Z222, which is created by the holes 1 1.
• the ratio between the "axial" air flow rate and the "orthoradial" air flow rate is between 0% and 100%, in particular of the order of 50%.
• a ratio of 0% results in a narrow directional jet and a straight air while a ratio of 100% results in a swirling wide jet and a vortex air.
• the holes 9 formed in the upper part of the core 5 have an oval section. This indicates that the holes 9 extend in a direction D9 oblique with respect to the axis Z222. More precisely, the direction D9 is divergent, with respect to the axis Z222, in the direction of the ejection. Thus, the air circulating in the holes 9 is ejected so that the second air gap L3 has a frustoconical geometry which diverges in the direction of the spray with respect to the axis Z222.
• A1 is an angle between the direction D9 and Z222 axis, this angle A1 is in practice between 45 ° and 75 °, preferably of the order of 60 °.
• the paint injected into the pipe 17 passes axially between the nozzle 3 and the core 5, which forms at the outlet of the nozzle a straight jet, that is to say that the droplets of the blade L1 are ejected parallel to the Z222 axis.
• the paint blade L1 is, on the one hand, struck at high speed by the internal air knife L3 and, on the other hand, sheared externally by the external air knife L2.
• the internal air gap L3 makes it possible to atomize the paint slide L1 in the form of droplets, which improves the smoothness of the spray, whereas the external air knife L2 causes the droplets of the jet L1 to rotate around it. of the Z222 axis, which gives the jet a good stability.
• the paint blade L1 is pinched between the first air gap L2 and the second air gap L3, which allows to refine the thickness of the jet during spraying. Finally, the paint blade L1 being impacted or sheared on both sides, that is to say on its inner and outer radial surfaces, this results in a good distribution of the friction forces of the air blades L2 and L3 on the L1 paint blade, which allows to homogenize the size and distribution of the droplets within the paint stream.
• the module 222 contains a vibrator 31.
• This vibrator 31 is arranged axially below the core 5 and is in contact therewith. It may be a piezoelectric vibrator that operates by feeding a piezoelectric AC material with a predetermined frequency so as to alternately deform in compression and traction. These successive deformations of the vibrator 31 cause vibrations that propagate within the core 5 as represented by the two-way arrow F4. Thus, disturbances appear within the paint blade L1, which tends to break down the blade L1 into droplets.
• the vibration frequency of the vibrator 31 is adjusted according to the desired droplet size. This frequency is to be adjusted according to the geometry of the vibrating component and the desired size of the drops. It is between 20 and 150 Hz depending on the technology used: piezo-electric, ultrasonic or other.
• This vibrator 31 is supplied with electric current by the high voltage production unit 23.
• FIGS. 9 to 13 show a second embodiment of a module 222 of a sprayer 22.
• the core 5 extends beyond the nozzle 3 and the cover 1 by a bowl 19.
• the free end of the core 5 is no longer flush with the free end of the cover 1 and
• the hood 1 is flush with the end of the nozzle 3.
• the bowl 19 has a bell-shaped geometry which is flared upwards relative to the axis 2212. , that is to say in the direction of spraying.
• the cover 1 is screwed in the upper part of the base 4.
• the bowl 19 is perforated by eight holes 9 of air passage to form the air gap L3.
• the holes 9 communicate with an internal cavity V5 of the core 5 which extends parallel to the axis Z222.
• the holes 9 diverge, with respect to the axis Z222, in the direction of the spraying.
• the holes 9 each extend in a direction D9 which is included in a plane containing the axis Z222 and which forms an angle A1 with the axis Z222.
• the angle A1 is purely "radial", that is to say that it is included in a plane containing the axis Z222.
• This angle A1 is in practice between 0 ° and 60 °, preferably of the order of 45 °.
• the air ejected from the holes 9 tends to stick to the inner surface of the bowl 19.
• the bowl 19 is advantageously cleanable by injecting a rinsing product in the third passage P3.
• a supply duct 7 conveys the air from the air supply unit 25 to radial holes 7A which open into the cavity V5.
• the paint enters through the duct 17 in the module 222, passes through the nozzle 3 until it passes into a passage P1 disposed between the bowl 19 and the nozzle 3.
• the nozzle 3 seals the bowl 19 that the paint slides along the outer surface of the bowl 19 at the output of the module 222.
• the passage P1 has a complementary geometry of the bowl 19, that is to say flared upwards.
• the fact of using a bowl 19 for guiding the paint jet at the outlet of the sprayer 22 makes it possible to control the shape of the jet. Indeed, several ranges of bowl can be used to modify the width or the shape of the jet.
• the use of a bowl in a sprayer is known per se, but rather as an extension of the nozzle of the sprayer.
• the sprayer 22 comprises a bowl 19 fixed which forms an extension of the core 5. So we speak of a stationary bowl sprayer. The fact of using a stationary bowl makes it possible to dispense with means for driving the bowl in rotation about the spraying axis, which makes the sprayer more compact, more reliable and more economical.
• this module 222 does not have a skirt interposed between the cover 1 and the nozzle 3.
• the air injected to form the outer air gap is not mixed within an internal chamber of the 222.
• the air is ejected through holes 14 which pass through the nozzle 3, which open directly towards the bowl 19 and which form an outer air blade having a generally helical direction. More precisely and with reference to FIGS. 12 and 13, the air circulates in a passage duct 16 passing through the base 4 until it reaches a serpentine chamber V16, from which it escapes to pass through the holes 14.
• holes 14 extend in a direction D14 which is both oblique with respect to the axis Z222 and tangential with respect to this axis Z222.
• the direction D14 lies in a plane perpendicular to a radial axis Z222 axis and forms an angle A3 with an axis parallel to the axis Z222.
• this angle A3 is purely "orthoradial", that is to say that it is contained in a plane perpendicular to a radial axis to the axis Z222.
• the A3R angle is in practice between -60 ° and + 60 °, preferably of the order of -45 ° or 45 °.
• the angle A3R is in practice between -30 ° and + 30 °, preferably 10 °.
• the air flowing through the holes 14 comprises an axial component F2b and an orthoradial component F2a.
• the set of holes 14 thus defines the passage P2 of the air and confers, to the resulting external air knife, a helical direction around the axis Z222.
• the paint blade runs along the outer surface of the bowl 19 and is then impacted externally by the air gap because the holes 14 are oriented toward the bowl 19.
• the paint blade is kept pressed against the bowl 19 and its thickness decreases under the pressure of the external air jet.
• the external air jet causes, by shearing, the spray of paint in rotation around the axis Z222 to guide the paint jet to the workpiece and make it more stable.
• the paint reaches the edge of the bowl 19, it is struck at high speed by an internal air gap. The internal air gap therefore atomizes the jet of paint in the form of droplets.
• the bowl 19 has a relatively thin thickness between 0.5 mm and 2 mm, in particular of the order of 1 mm so that the spray paint off of the bowl 19 with a thin edge.
• the paint droplets have little surface to catch, which improves the fluidity of the spray.
• the module 222 also comprises a vibrator 31 disposed in contact with the core 5. The fact of vibrating the core 5 makes it possible to accentuate the atomization of the jet of paint in droplets. In fact, the vibrations generated within the paint jet cause turbulence leading to the formation of droplets.
• the vibration frequency is adjusted according to the desired droplet size. In practice, this frequency is in the same range as that of the vibrator equipping the sprayer 22 according to the first embodiment.
• FIGS. 14 and 15 show a third embodiment of a sprayer 22.
• the skirt 6 and the nozzle 3 are in one piece, only the reference of the nozzle 3 is thus pointed in FIG.
• the sprayer 22 differs from the sprayer of FIGS. 9 to 13 in that the outer air knife is, similar to the sprayer of FIGS. 2 to 8, formed by a mixture of two airs within a chamber V10. More precisely and with reference to FIG. 15, an axial air inlet opens into chamber V10 through holes 13 and an orthoradial air inlet opens into chamber V10 through holes 11. The mixture of these two air inlets forms a vortex within the chamber V10, that is to say that the air circulates with a helical direction centered on the Z222 axis.
• the cover 1 comprises an internal bore S1 which is frustoconical in shape and which converges upwards in the direction of the axis Z222.
• the sprayer 22 according to the third embodiment does not include a vibrator.
• FIGS. 16 to 19 show a fourth embodiment of a module 222 of a sprayer 22. This latter mode differs little from the second embodiment of FIGS. 9 to 13.
• the outer air space is formed by a set of holes 14 regularly distributed around the core 5. These holes 14 eject the air present in a chamber V16, which is fed by a duct 16. The holes 14 form a passageway P2 of the air and are inclined to form a swirling outer air space, that is, having a helical direction. This air space external comes shearing the spray of paint that runs along a bowl 19 through a passage P1.
• air is also ejected within the core 5 through holes 9 which eject air arriving in a cavity V5.
• These holes 9 are divergent with respect to the axis Z222, which creates an inner air space of frustoconical shape inside the bowl 19. This internal air space atomizes the spray paint at the edge of the bowl 19. The spray of paint is then sprayed in the form of droplets.
• the chamber V16 no longer has a serpentine shape but completely surrounds the nozzle 3 and communicates with several ducts 16 for air passage.
• the vibrator 31 comprises a rod 33 which bears in a notch arranged in the lower part of the core 5 and a spring 35 which makes it possible to accentuate the vibrations.
• the angle A1 of inclination of the holes 9 is not purely "radial". Indeed, the angle A1 comprises, when projected in a plane containing the axis Z222, a component A1 R and, when projected in a plane perpendicular to the plane containing the axis Z222, a component A1 T
• the angle A1T is between -60 ° and 60 °, preferably of the order of 0 ° and the angle A1 R is between 0 ° and 60 °, preferably of the order of 45 °. °.
• the angle A3 of inclination of the holes 14 is not purely "orthoradial". Indeed, the angle A3 comprises, when projected in a plane containing the Z222 axis, a component A3R and, when projected in a plane perpendicular to the plane containing the axis Z222, an A3T component.
• the angle A3T is between -60 ° and 60 °, preferably of the order of -45 ° or 0 ° and the angle A3R is between -30 ° and 30 °, preferably from order of 10 °.
• the vibrator 31 is magnetic, pneumatic or electric. In variant not shown, the vibrator 31 vibrates the nozzle 3 or the bowl 19.
• the internal air space is straight, that is to say that the air is ejected from the third passage P3 in a direction parallel to the spray axis.
• the outer air space is straight, that is to say that the air is ejected from the second passage P2 in a direction parallel to the spray axis.
• the first passage P1 of the product is formed by several disjoint passage sections.
• the sprayed product may be any liquid coating product, in particular:
• sol an inorganic polymer, known by the generic name of sol, which is used in a sol-gel process
• the outer air gap is not swirling, that is to say that it does not cause the product jet to rotate around the spraying axis Z222.
• the sprayer 22 is an electrostatic sprayer, which means that the workpiece 26 to be treated is grounded while the product particles ejected from the sprayer 22 are electrostatically charged. An electrostatic field is then created between the sprayer and the workpiece, so as to channel the jet.
• the internal air knife L3 is swirling, that is to say that the air ejected from the third passage P3 has a helical direction which can be oriented in the same direction as the direction of the blade. external air L2 or in the opposite direction.
• the internal air blade L3 is ejected from an annular passage.
• the air circulating in this passage has a direction divergent with respect to the Z222 axis.
• the core may, for example, have an internal bore, inside which the air circulates, which is frustoconical and which diverges with respect to the axis Z222 in the direction of the spray.
• the product blade is also swirling, in the same direction or in the opposite direction of the outer air space.
• At least two parts among the nozzle 3, the skirt 6, the hood 1, the base 4 and the core 5 are monobloc.

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• Special Spraying Apparatus (AREA)
• Electrostatic Spraying Apparatus (AREA)

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• 2013
  • 2013-08-13 FR FR1357992A patent/FR3009688B1/fr active Active
• 2014
  • 2014-08-12 JP JP2016533907A patent/JP2016530091A/ja active Pending
  • 2014-08-12 EP EP14750372.6A patent/EP3033180A1/de not_active Withdrawn
  • 2014-08-12 WO PCT/EP2014/067251 patent/WO2015022328A1/fr active Application Filing
  • 2014-08-12 CN CN201480045386.6A patent/CN105473234A/zh active Pending
  • 2014-08-12 US US14/909,773 patent/US20160199869A1/en not_active Abandoned
  • 2014-08-12 KR KR1020167003679A patent/KR20160042898A/ko not_active Application Discontinuation

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