Classifications

• • 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
  • B05B1/26—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets
  • B05B1/262—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors
  • B05B1/267—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with means for mechanically breaking-up or deflecting the jet after discharge, e.g. with fixed deflectors; Breaking-up the discharged liquid or other fluent material by impinging jets with fixed deflectors the liquid or other fluent material being deflected in determined directions
• • 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
  • B05B1/04—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 flat form, e.g. fan-like, sheet-like
  • B05B1/046—Outlets formed, e.g. cut, in the circumference of tubular or spherical elements
• • 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
  • B05B5/032—Discharge apparatus, e.g. electrostatic spray guns characterised by the use of gas, e.g. electrostatically assisted pneumatic spraying for spraying particulate materials

Definitions

• the present invention relates to a powder diffusion nozzle for an electrostatic powdering device.
• Electrostatic dusting of mechanical parts is carried out in a known manner by automatic installations comprising for example an application booth that the parts pass through as well as application guns projecting the powder substantially perpendicular to the axis of movement of the parts in the booth .
• the geometry of the parts to be powdered may require the orientation of the powder jet of the application guns at a given angle relative to the axis of the gun support arm, so as to reach obscured areas relative to the axis. of the support arm.
• Devices are used making it possible to orient the powder jet, resting on an articulation of the pistol or of a part of the pistol with respect to the arm supporting the pistol.
• each gun has an internal duct for supplying a powder jet, a terminal nozzle for shaping the jet, and a device for ionizing the powder.
• the latter device comprises in particular a high voltage source and a tip located near the end of the gun and intended to ionize the powder.
• the ionization tip can commonly have an electrical potential of 80 kV relative to earth.
• An electric arc can therefore form if the end of the gun is approached by another object connected to the ground. Since the formation of electric arcs can damage the installation and cause explosions in powdered saturated environments, regulations limit the capacity of the entire installation to 5 milli joules. This capacity limitation constraint must be respected by all the devices used.
• the present invention provides a solution to the technical problems mentioned while respecting the constraints described above.
• the present invention relates to a powder diffusion nozzle for an electrostatic powdering device intended to be positioned at the end of an application gun, the nozzle comprising a side wall delimiting a passage extending the powder conduit. gun, and a bottom closing the duct at its end, characterized in that at least one orifice is formed in the side wall near the bottom connecting the powder duct to the outside of the nozzle, the axis of the orifice forming a determined angle with the axis of the powder duct and in that at least one deflector is formed on the bottom of the nozzle or on the side wall near the bottom of the nozzle allowing the powder jet to be deflected of the conduit in the axis of the orifice.
• the nozzle makes it possible to achieve the desired orientation of the jet while preserving a minimum bulk, the whole of the gun remaining in the same axis.
• the part on which the wear due to the orientation of the jet relates is the deflector and not the wall of the duct.
• This arrangement is advantageous since the deflector is easily accessible and replaceable.
• at least one deflector has, seen in section along a plane parallel to the plane comprising the axis of the conduit and the axis of the orifice, a profile consisting of a straight segment forming with the axis of the conduit a angle substantially equal to the angle between the axis of the orifice and the axis of the conduit.
• At least one deflector has, seen in section along a plane parallel to the plane comprising the axis of the duct and the axis of the orifice, a profile consisting of two straight segments, the angle of the first segment being included in a zero value and the value of the angle between the axis of the orifice and the axis of the conduit and the angle of the second segment, the closest to the orifice, relative to the axis of the conduit being substantially equal to the angle between the axis of the orifice and the axis of the conduit.
• At least one deflector has, seen in section along a plane parallel to the plane comprising the axis of the conduit and the axis of the orifice, a profile constituting a curve of increasing slope, the angle of the tangent to the curve with respect to the axis of the conduit near the orifice being substantially equal to the angle between the axis of the orifice and the axis of the conduit.
• the deflector can have various shapes, depending on the type of powder used or the inclination sought. For example, the arrangement comprising two segments is adapted to an angle of the axis of the orifice relative to the axis of the conduit of the order of 90 °.
• At least one deflector has, seen in section along a plane perpendicular to the axis of the duct, a concave profile.
• at least one deflector has, seen in section along a plane perpendicular to the axis of the duct, a straight profile.
• the modification of the profile of a deflector in section along a plane perpendicular to the axis of the duct makes it possible to modify the spontaneous distribution of the powder.
• a concave profile makes it possible to compensate for a spontaneous distribution concentrating on the two lateral edges of the orifice. This type of profile makes it possible to maintain the homogeneity of the jet at the outlet of the nozzle.
• At least the terminal part of the nozzle comprising the orifice, the bottom and the deflector is mounted orientable along the axis of the duct on the end of an application gun.
• the pivotally mounted end part allows the jet to be oriented along a second axis, always retaining a minimum space requirement.
• at least the terminal part of the nozzle comprising the orifice, the bottom and the deflector is detachably fixed on the end of an application gun.
• the detachable nozzle allows on the one hand to change a nozzle for another having a different angle of orientation of the jet, but also to replace all or part of the nozzle if the deflector or the orifice is worn by friction powder.
• the nozzle comprises an ionization point of the powder jet, arranged in the axis of the conduit and oriented in the direction of the powder jet, the free end of which is located in the conduit, upstream from the bottom in the direction of the throw.
• the nozzle comprises an ionization point of the jet of powder, the free end of which is located near the bottom of the nozzle outside of the latter.
• the ionization point of the powder jet arranged in the axis of the duct and oriented in the direction of the powder jet, crosses the bottom of the nozzle by a passage formed in the bottom of the nozzle.
• the nozzle comprises a jet ionization spike "powder whose free end is located near the orifice and the side wall, on the outside of the nozzle.
• the tip ionization of the powder jet the base of which is arranged in the axis of the duct and oriented in the direction of the powder jet, crosses the bottom of the nozzle forming a bend to emerge through the side wall of the nozzle near the orifice through a passage in the bottom and the side wall of the nozzle.
• the angle between the axis of the orifice and the axis of the powder duct is between 10 ° and 90 °.
• the angle between the axis of the orifice and the axis of the powder pipe is between 45 ° and 90 °.
• the orifice has the form of a slit oriented transversely with respect to the axis of the powder duct.
• Figure 1 is a longitudinal sectional view in a first embodiment, the nozzle being fixed on an application gun.
• Figure 2 is a perspective view in a first embodiment.
• Figure 3 is a longitudinal sectional view in a first embodiment.
• Figure 4 is a longitudinal sectional view in a second embodiment.
• Figure 5 is a longitudinal sectional view in a third embodiment.
• Figure 1 shows a powder diffusion nozzle 2 according to the invention fixed on the end of an application gun 3.
• the gun 3 comprises a barrel 4 at the front end of which is provided a shoulder 5 then a cylindrical wall 6 comprising an external thread 7 over a part of its length.
• the gun 3 also includes a straight powder pipe 8 which extends into the nozzle 2. A powder jet is fed into the pipe in the direction of arrow J.
• the cylindrical wall 6 delimits a support wall 9 perpendicular to the axis of the duct 8, a passage being provided for the duct 8 in this support wall 9, a notch 10 being provided in the portion of the wall of the duct 8 closest to the support wall 9.
• the gun 3 includes a device called cascade 12 providing by a screw 13 a high voltage source.
• the cascade device 12 is a voltage multiplier making it possible to generate, for example, a high voltage of 80 kV from a supply voltage of 300 V.
• the screw 13 is housed in a recess 14 formed in the support wall 9
• a keying device 15 is formed on the support wall 9 allowing positioning relative to the recess 14 as described below.
• the nozzle 2 comprises a base 16 comprising a cylindrical portion 17 in which is formed a passage for the powder conduit 8.
• the rear part 18 of the cylindrical portion 17 has an outside diameter substantially identical to the internal diameter of the cylindrical wall 6 of the barrel 4. This rear part 18 can thus be housed on the front part of the barrel 4 in the space delimited by the cylindrical wall 6 and the bearing wall 9 of the barrel 4.
• the base 16 comprises in addition, a support 19 in the form of a spindle located in the axis of the conduit e and connected to the cylindrical portion 17 by a lug 20.
• the support 19 has on its front part a shoulder 22 and a tubular portion 23 of section smaller than l shoulder 22, allowing the attachment of a resistance tube 24.
• This tube resistor 24 is intended to be fixed by one end to the tubular portion 23, and has at its other end an opening 25 of diameter corresponding to the diameter of an ionization tip 26.
• This tube 24 and the support 19, intended to be nested, constitute a housing for a damping resistor 27 and an ionization tip 26 passing through the opening 25 of the resistance tube 24.
• the damping resistor 27 mounted in series with the ionization tip 26 makes it possible to reduce the electrical intensity exchanged in the event of an electric arc.
• An electrical connection is provided between the damping resistor 27 and the screw 13 high voltage source by a conductive insert 28 passing through the support 19, the tab 20 and the cylindrical portion 17 and being connected to a terminal 29 located on the rear wall 30 of the base 16.
• the terminal 29 is located opposite the recess 14 of the support wall 9 containing the screw 13.
• a spring 32 housed in the recess 14 then establishes contact between the screw 13 and the terminal 29.
• a notch 33 is formed on the rear wall 30 of the base 16, complementary to the polarizing device 15 formed on the support wall 9 of the barrel 4, intended to house the latter when the base 16 is in contact with the support wall 9, so as to guarantee the positioning opposite the terminal 30 and the recess 14.
• the base 16 also has a short cylindrical wall 34 formed on its side i rear 30, projecting and surrounding the passage of the powder conduit 8, this wall 34 being intended to bear in the notch 10 formed in the portion of the wall of the conduit e close to the support wall 9 of the barrel 4
• a circular stop 35 is formed on the outer wall 36 of the cylindrical portion 17.
• the base 16 further comprises a tubular portion 37 comprising a passage for the powder conduit 8 and formed at the front end of the cylindrical portion 17 , the thickness of this tubular portion 37 decreasing away from the cylindrical portion 17.
• the nozzle 2 also includes a nozzle nut 38 intended to fix the base 16 on the barrel 4 of the gun 3.
• This nut 38 has a tubular shape of variable diameter, and comprises, from back to front: - a section 39 in which the internal wall 40 of the nut includes a thread 42 intended to cooperate with the external thread 7 of the end of the barrel 4 of the gun 3, - a section 43 of constant internal diameter substantially equal to the diameter of the circular stop 35 of the base 16, - a section 44 of inner diameter smaller than the diameter of the circular stop 35 of the base 16, whose shoulder 45 is intended to bear on the circular stop 35, so as to maintain the base 16 in position between the support wall 9 of the barrel 4 and the nut 38, - a frustoconical section 46 whose diameter decreases from the previous section 43, an opening 47 being formed at the end of this frustoconical section 46, the internal diameter of which is equal to the maximum external diameter of the tubular portion 37 of the base 16, this tubular portion 37 being intended to pass through the opening 47 when the base 16 is fixed.
• the nozzle 2 further comprises a nozzle 48 comprising a side wall 49.
• This side wall 49 of tubular shape comprises: - a rear section 50 of diameter varying between a maximum value at the rear edge 52 of the nozzle 48 and a value minimum in front of the rear edge.
• the profile of the inner wall of this section 50 corresponds to the profile of the outer wall of the tubular portion 37 of the base 16. This section 50 can therefore be fixed by clamping on the tubular portion 37 of the base.
• a housing 53 for a seal 54 is formed on the internal wall of this section 50. The seal 54 located in this housing 53 strengthens the mechanical retention of the end piece 48 on the base 16, and - a front section 55 of constant diameter, the side wall 49 delimiting a passage for the powder conduit 8.
• the end piece 48 also includes a bottom 56 closing the duct 8 at its front end.
• An orifice 57 is formed in the side wall 49 of the endpiece 4 ⁇ near the bottom 56, the orifice 57 connecting the powder conduit ⁇ to the outside of the nozzle 2, the axis A1 of the orifice 57 forming an angle A with the axis A2 of the powder ⁇ conduit.
• the angle A is equal to 60 ° and the orifice 57 has the form of an elongated slot forming an angle at the center of 90 ° in the plane of the slot.
• the plane of the slot intersects the axis A2 of the conduit by forming the angle A, the slot therefore being oriented transversely with respect to the axis A2 of the conduit.
• a deflector 58 is formed on the bottom 56 of the nozzle 2 making it possible to deflect the powder jet from the conduit e in the axis A1 of the orifice 57. In the embodiment shown in FIG.
• the deflector 58 has at section by a plane parallel to the plane comprising the axis A2 of the conduit and the axis A1 of the orifice a straight profile inclined at 60 °, corresponding to the angle A of the axis A1 of the orifice 57 relative to the axis A2 of the conduit 8.
• the deflector 58 and the orifice 57 are located close to each other, the front edge 59 of the orifice 57 being in the extension of the deflector 58.
• This end piece 48 comprising an orifice 57 and a deflector 56 oriented make it possible to orient the powder jet, without causing any problem of space.
• the tip thanks to its method of attachment can be replaced and positioned easily.
• the ⁇ duct does not suffer from excessive wear on its walls because it is straight.
• the tip 26 is visible and constitutes a point close to an object approached the end of the gun. Indeed, the point shape allows the creation of leakage current before the formation of the arc, allowing either to avoid the formation of the arc, or to significantly reduce the electric intensity exchanged during the formation of the arc.
• the embodiments presented comply with the regulations. In the first embodiment shown in Figures 1, 2 and 3, the free end 60 of the ionization tip 26 is disposed in the axis of the conduit 6 and its end is located upstream of the bottom 56 in the direction of the jet in the ⁇ duct. According to a second embodiment shown in FIG.
• the resistance tube 24 and the ionization point 26 of the powder jet pass through the bottom 56 of the nozzle 2.
• the ionization point then forms an elbow for emerge through the side wall 49 of the nozzle 46 of the nozzle 2 near the orifice 57.
• a passage 62 is formed in the bottom 56 and the side wall 49 in contact with the bottom 56 of the nozzle 2, to allow the passage of the point.
• the free end 60 of the tip 26 being located near the front edge 59 of the orifice 57 on the outside of the nozzle 2.
• a seal 64 is contained in a housing 63 formed in the wall of the passage 62
• the ionization point is composed of two straight portions 65 and 66, one 65 lying in the axis of the duct, the other 66 in the direction of the free end, as well as d 'an electrical contact rubbing 67, housed in the elbow of the conduit, and maintaining an electrical connection between the two straight portions.
• This contact 67 makes it easier to mount the nozzle 2, as well as the orientation of the latter, the straight portion 65 of the tip 26 remaining in position, while the straight portion 66 pivots with the end piece 46.
• a third embodiment shown in FIG.
• the resistance tube 24 and the ionization point 26 of the powder jet pass through the bottom 56 of the nozzle 2 by a passage 62 formed axially in the bottom 56 of the nozzle 2, the free end 60 of the tip 26 being located near the bottom 56 of the nozzle 2 outside of the latter.
• a seal 64 is contained in a housing 63 formed in the wall of the passage 62.
• the profile of the deflector 56 in section along a plane perpendicular to the axis A2 of the conduit ⁇ may have different shapes, depending on the effect research.
• the deflector 5 ⁇ may have a concave profile, so as to compensate for a spontaneous distribution of the powder concentrating on the two lateral edges of the orifice 57.
• This type profile allows to maintain the homogeneity of the jet at the outlet of the nozzle 2.
• the orifice 57 has in this case a slightly curved shape adapted to the concavity of the deflector 5 ⁇ .
• a deflector has, in section along a plane parallel to the plane comprising the axis of the duct and the axis of the orifice, a profile consisting of two straight segments, the angle of the second segment by relative to the axis of the conduit ⁇ being equal to the angle between the axis of the orifice and the axis of the conduit, the angle of the first segment being equal by example at half the value of the angle between the axis of the orifice and the axis of the duct.
• This arrangement comprising two segments is particularly advantageous in the case where the angle of the axis of the orifice relative to the axis of the conduit of the order of 90 °.
• a deflector has, in section along a plane parallel to the plane comprising the axis of the duct and the axis of the orifice, a profile constituting a curve of increasing slope, the angle of the tangent to the curve near the orifice being equal to the angle between the axis of the orifice and the axis of the conduit.
• the deflector has a shape and a surface making it possible to deflect the powder jet as a whole, or at least a substantial part of the jet, greater than 50%.
• the nozzle tip and the base are formed by a single orientable part.
• This part does not include a polarizing pin and can therefore be oriented in rotation around the axis of the duct, when the nut is loosened.
• the electrical connection between the ionization tip and the high voltage source can be made by a contact provided axially or by a contact having an annular shape centered on the axis of the conduit.
• the angle A between the axis A1 of the orifice 57 and the axis A2 of the conduit ⁇ can take various values, in particular between 10 and 90 °.
• the invention is not limited to the embodiments described, on the contrary it embraces all variants.
• the deflectors 56 can have different profiles.

Landscapes

• Electrostatic Spraying Apparatus (AREA)
• Nozzles (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Coating Apparatus (AREA)
• Details Or Accessories Of Spraying Plant Or Apparatus (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=33522820

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• 2003
  • 2003-07-07 FR FR0308281A patent/FR2857279B1/fr not_active Expired - Fee Related
• 2004
  • 2004-07-07 EP EP04767605A patent/EP1641567B1/de not_active Expired - Lifetime
  • 2004-07-07 AT AT04767605T patent/ATE344102T1/de not_active IP Right Cessation
  • 2004-07-07 DE DE602004003064T patent/DE602004003064D1/de not_active Expired - Lifetime
  • 2004-07-07 WO PCT/FR2004/001770 patent/WO2005005056A1/fr active IP Right Grant
  • 2004-07-07 BR BRPI0412359-0A patent/BRPI0412359A/pt not_active Application Discontinuation
  • 2004-07-07 US US10/564,218 patent/US7401745B2/en not_active Expired - Fee Related
  • 2004-07-07 JP JP2006518292A patent/JP2007516061A/ja active Pending
  • 2004-07-07 CA CA002531668A patent/CA2531668A1/fr not_active Abandoned
• 2007
  • 2007-01-10 GB GBGB0700447.6D patent/GB0700447D0/en active Pending

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