EP1307295A1

EP1307295A1 - Device for spraying coating product comprising a nozzle

Info

Publication number: EP1307295A1
Application number: EP01960872A
Authority: EP
Inventors: Michel Di Gioia; François VASSEUR
Original assignee: Sames Technologies SAS
Current assignee: Sames Kremlin SAS
Priority date: 2000-08-07
Filing date: 2001-08-06
Publication date: 2003-05-07
Also published as: FR2812567A1; FR2812567B1; WO2002011896A1; US20020017239A1

Abstract

The invention concerns a device comprising a gun (1), wherein is defined a conduit (2) circulating coating product, and a nozzle (3) for forming the jet of product designed to be mounted on said gun. Means are provided (4, 6) for magnetic coupling (F1) between the nozzle (3) and the gun (1). Said means (4, 6), which are isolated from the conduit (2), can consist of one or several magnets (6) associated with a metal ring (4) thereby providing easy and fast assembling and disassembling of the nozzle (3) on the end of the gun (1).

Description

COATING PRODUCT SPRAYING DEVICE

INCLUDING A NOZZLE

The invention relates to a coating product projection device equipped with a nozzle.

In an installation for spraying coating product, liquid or particulate, it is known to spray the product by discharging it from the downstream end of a conduit provided in the barrel of a manual or automatic projector. A nozzle is generally used to shape the spray of sprayed coating product according to the type of application.

It is known to screw a nozzle onto the downstream end of a barrel. Such a screwing operation is relatively long and requires special care for good cooperation of a thread and a tapping provided respectively on the barrel and the nozzle. These threads and threads are most often made of a plastic material constituting the barrel and the nozzle, in particular for electrostatic sprayers. They can therefore be distorted in the event of improper handling. In addition, coating material may accumulate on these threads and threads, whether they are droplets of liquid coating material or powder particles. However, it is often necessary to dismantle and clean a shaping nozzle after a few hours of use in order to evacuate agglomerates which can form inside and / or outside the nozzle. This induces repeated manipulations of unscrewing and screwing a nozzle onto a barrel, with the aforementioned drawbacks.

It is to these drawbacks that the invention more particularly intends to remedy by proposing an improved solution for rapid assembly and disassembly of a shaping nozzle at the end of the barrel of a headlight.

In this spirit, the invention relates to a device for spraying a coating product comprising a barrel, inside which is defined a circulation duct for coating product, and a nozzle for shaping the jet of product, this nozzle being intended to be mounted on this barrel, characterized in that it comprises magnetic coupling means between this nozzle and this barrel, these means being isolated from the duct supra.

Thanks to the use of magnetic coupling means, the assembly and disassembly of the nozzle on the barrel is particularly rapid since it suffices to approach the nozzle sufficiently close to the barrel for the magnetic coupling to produce a securing effect and either effective. Conversely, disassembly takes place by simply removing the magnetic coupling means from one another. These magnetic coupling means also allow magnetic self-centering of the nozzle relative to the barrel. In addition, as the coupling means are isolated from the product circulation duct in the configuration mounted from the nozzle to the barrel, they are not likely to be soiled or fouled by a deposit of product. This contributes to the sustainability of the coupling obtained. According to an advantageous advantageous aspect of the invention, the nozzle is provided with a ring forming a peripheral partition of an end portion of the conduit, this ring being disposed between this conduit and the magnetic coupling means. This ring effectively isolates the coupling means from the coating product flow.

According to a first embodiment of the invention, the barrel is equipped with at least one magnet capable of cooperating with a magnetic looping element carried by the nozzle.

According to another advantageous embodiment of the invention, the nozzle is equipped with at least one magnet capable of cooperating with a magnetic looping element carried by the barrel.

Whatever the embodiment considered, provision can be made for the coupling means to be located around the barrel. In this case, these means are arranged at a distance from the head of the sprayer in which an electrostatic charge would be likely to accumulate in the case of an electrostatic sprayer. In other words, the fact of placing the magnetic coupling elements at a distance from the zones likely to be brought to high voltage limits the risks due to the electrical capacity of the metallic masses constituting these coupling means and, in particular, of the metal magnets and / or rings used.

According to another advantageous aspect of the invention, the looping means is formed by a metal ring centered on a longitudinal axis of the duct and the nozzle.

According to another advantageous aspect of the invention, the device comprises means for mechanical centering of the nozzle on the barrel, these centering means being able to allow relative pre-positioning of the magnetic looping means during mounting of the nozzle on the Canon.

According to another advantageous aspect of the invention, the magnetic looping means form contacts of a voltage supply circuit of means for electrostatic charging of the product provided in the nozzle. In this case, these contacts are advantageously formed by one end of a magnet and by a magnetic looping element in the form of a metal ring.

It is further possible to provide that the device comprises controlled means for injecting a separation fluid between the barrel and the nozzle, with sufficient pressure to overcome the coupling force of the coupling means. This creates a pneumatic disassembly system for the nozzle. In this case, the aforementioned control means can be mounted in or on the device, preferably in or on the barrel. These means can be controlled manually or automatically. According to another advantageous aspect of the invention, the coupling means, and in particular the magnets and rings, used are removably installed on the barrel and / or on the nozzle. This facilitates maintenance of the device.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the description which follows of three embodiments of a device for spraying coating product in accordance with its principle, given only to as an example and made in reference to the accompanying drawings in which:

- Figure 1 is an exploded axial section of the downstream end of a projection device according to a first embodiment of the invention; - Figure 2 is a section along line II-II in Figure 1;

- Figure 3 is an axial section on a larger scale of the device of Figure 1 in mounted configuration;

FIG. 4 is a view similar to FIG. 3 for a device according to a second embodiment of the invention, and

- Figure 5 is a side view, with partial longitudinal section, of a device according to a third embodiment of the invention. The device partially shown in Figures 1 to 3 comprises a barrel 1 of which only the downstream end is shown. This barrel is centered on an axis XX ′ which also constitutes the axis of symmetry of a conduit 2 through which the coating product flows. In the example shown, the projector is used with a powder coating material so that a mixture of air and powder passes through the conduit.

The barrel 1 ends with a sleeve 11 which extends the barrel 1 beyond the outlet 21 of the conduit 2. The sleeve 11 is defined by an internal surface 12, cylindrical and with straight generator, and by an external surface 13, also cylindrical and forming an external shoulder 14.

A veil 15 extending along a plane generally perpendicular to the axis XX 'connects the sleeve 11 and the external surface of the barrel 1 to a sleeve 16 forming a housing for receiving the downstream end 22 of the conduit 2. In the example shown, the duct 2 is formed of two concentric tubes in its downstream part 22, but this is not compulsory.

A nozzle 3 is provided to be mounted on the barrel 1 and comprises a main body 31 defining a central duct

32 for circulation of the air and powder mixture. A rod 33 is disposed in the channel 32 and contains electronic components 34 enabling high voltage to be supplied to a electrode 35 provided in the downstream end 33a of the rod 33 which forms a deflector for the jet of air powder mixture. The rod 33 is integral with a ring 36 by means of lugs 37, the ring 36 being immobilized in the body 31, for example by screwing.

The body 31 forms an annular housing 38 intended to cover the sleeve 11, this housing comprising a first section 38a of greater width than a second section 38b forming the bottom of the housing 38. The geometry of the housing 38 allows it to accommodate the sleeve 11, the width of sections 38a and 38b being adapted to the two successive widths of the sleeve 11 on either side of the shoulder 14.

The nozzle 3 is equipped with a steel ring 4 installed in a removable manner in a housing 39 provided around the ring 36. The ring 4 can be snapped into the housing 39 or fixed by any other means. However, a removable fixing method is preferred in order to facilitate maintenance of the nozzle 3.

A conductor 41 is provided in the ring 36 and one of the lugs 37 for connecting the ring 4 to one of the components 34 when the ring 4 is in place in the housing 39.

A contactor 5 is mounted in the barrel 1, through the web 15 and comprises a rod 51 projecting beyond the web 15 in the direction of the front of the barrel 1. In the mounted configuration of the device, the axis XX 'is a longitudinal axis of the duct 2 and the nozzle 3.

In the assembled configuration of the device, the rod 51 is in electrical contact with the ring 4, which makes it possible to apply to the components 34 a voltage supplied by the contactor 5 itself supplied by an electrical cable 52 from a high voltage training unit not shown. In the case where a high-voltage cascade is integrated in the barrel 1, the contactor 5 is supplied directly from it. In all cases, it is possible to supply high voltage, through the components 34, to the electrode 35 in order to create an electrostatic charge at the level of the deflector 33a.

Three magnets 6 are removably mounted in the veil 15 and extend from it over a length 1 ₆ substantially equal to the length 1 ₅ of the contactor 5 beyond the wall 15.

In the mounted configuration of the device shown in FIG. 3, the magnets 6 are therefore in contact with the ring 4 on which they exert a tensile force F _x which firmly plates the nozzle 3 on the body 1.

Thus, the elements 4 and 6 constitute magnetic coupling means between the barrel 1 and the nozzle 3.

It is noted that the ring 36, which extends the duct 2, isolates, in the configuration of FIG. 3, the volume of circulation of the product in the duct 2 and the channel 32 relative to the ring 4 and to the magnets 6, from so that the risk of product deposition on elements 4 and 6 is minimized. In particular, the front end surface 36a of the ring 36 is in firm support, under the effect of the force F-, against the downstream end of the duct 2. The risks of leakage towards the outside of the ring 36 are thus reduced.

As can be seen more particularly from FIG. 2, the device comprises three magnets 6 regularly distributed around the axis XX '. The number of magnets and their distribution depend on the intensity of the effort F _t sought.

We can consider using an annular magnet centered on the axis XX '. This solution however has the drawback of creating a relatively large metallic capacity near the discharge orifice of the projector, which proves to be penalizing in terms of electrical energy stored in this part of the device.

The sleeve 11 and the housing 38 allow relative prepositioning of the nozzle 3 and of the barrel 1, and in particular, of the magnetic coupling elements 4 and 6 relative to each other, during the approach movement of the nozzle 3 by relative to the barrel 1, this movement being represented by the arrow F ₂ in FIG. 1.

In the second embodiment of the invention shown in Figure 4, elements similar to those of the first embodiment bear the identical references increased by 100. In this embodiment, the barrel 101 of a projector is equipped nozzle 103 and includes a conduit 102 emerging opposite a central conduit 132 formed by the nozzle 103 around a rod 133 terminating in a deflector 133a equipped with a charging electrode 135 supplied by electronic components 134 placed in the rod 133.

A ring 136 belonging to the nozzle 103 comes to bear, by its end surface 136a, against the downstream end of the conduit 102 and surrounds the conduit 132, so that it guarantees that the product remains in the conduits 2 and 102 that it insulates from the outside.

As before, the nozzle 103 is provided with a metal ring 104 electrically connected to the components 134 by a cable 141. The ring 104 is supplied with current by a contactor 105 produced in the form of a magnet and itself supplied by conductive cables 152. Thus, the contactor 105 of this embodiment plays both the role of elements 5 and 6 of the first embodiment.

A single contactor magnet 105 can be used as long as the attraction force F-, exerted is sufficient. A pneumatic disassembly system 160 is provided which includes a tube 161 passing through the end plate 115 of the barrel 101 and connected to a source 162 of pressurized air through an electro-valve 163 controlled by a logic unit 164. When it should separate the. nozzle 103 of the barrel 101, the solenoid valve 163 is open, so that an air flow, represented by the arrow F ₃ , is injected into the volume V defined between the barrel 101 and the nozzle 103, which has the effect of exerting on the nozzle 103 an effort F ₄ sufficient to overcome the effort F _x of magnetic coupling. Of course, a pneumatic disassembly system which is optional can also be used with the device of the first embodiment.

In the third embodiment of the invention shown in Figure 5, elements similar to those of the first embodiment bear identical references increased by 200. In this embodiment, the barrel 201 of an automatic paint projector liquid is capped by a nozzle 203 which includes a skirt 203a surrounding the barrel 201 over most of its length, this skirt being in one piece with the head 203b of the nozzle 203. However, the nozzle 203 could consist of two assembled elements.

The skirt 203 carries, at its edge opposite the head 203b, a magnet 206 of annular shape and centered on the longitudinal axis XX 'of the nozzle 203 and of the barrel 201 in the mounted configuration of the sprayer. A metal ring 204 is permanently mounted around the barrel 201 in a position such that the magnet 206 abuts against the ring 204 when the nozzle 203 is in place on the barrel 201. An intense magnetic force F _x is thus created between the magnet 206 and the ring 204, this effort guaranteeing an adequate and lasting positioning of the nozzle 203 relative to the barrel 201.

The distance d between the magnet 206 and the front face 201a of the barrel 201, taken in the mounted configuration of the device, is such that electrical insulation is produced and that the metal parts 204 and 206 are not likely to charge at high tension, including when the sprayed liquid coating product is charged at high voltage due to an internal charging system or when the head 203b is equipped with electrodes for charging the liquid product externally.

The internal radial surface 203i of the skirt 203a and the external radial surface 201e of the barrel 201 have corresponding geometries making it possible to guide and center the nozzle 203 during its mounting on the barrel and, consequently, to correctly position the magnet 206 with respect to the ring 204.

A pneumatic disassembly system 260 is provided which includes a self-sealing push button 261 installed in the barrel 201 and connected by a pipe 262 to a source of pressurized air not shown. The downstream part of the push button 261 is connected by a pipe 263 to the volume V defined between the barrel 201 and the head 203b. As before, this system makes it possible to inject into the volume V an air flow, represented by the arrow F ₃ , to exert a force F ₄ sufficient to overcome the force F-, of magnetic coupling. The push button 261 is actuated by a head 261a easily accessible through an opening 203ç_ provided in the skirt 203a.

Of course, other variants can be envisaged and an automatic control system can be used in place of the manual push button 261. The skirt 203a can also be shorter than in the example shown in FIG. 5, in which case the distance d is less. This nevertheless allows good insulation of the metallic elements to be obtained with respect to the high voltage essentially present in or in the immediate vicinity of the volume V. In this case, the push button 261 can be located towards the rear of the sprayer relative to the elements magnetic coupling. It is thus accessible without the need to create an opening in the skirt.

The skirt 203d of the terminal part of the nozzle 203 which carries the magnet 206 comes to bear against the barrel 201 and the ring 204, so that it isolates the elements 204 and 206 from the volume V which is itself advantageously insulated from the coating product circulation duct.

The invention can be used with a projector of the manual or automatic type and can be implemented for the projection of liquid or pulverulent coating product. In particular, the technical characteristics of the various embodiments shown can be combined with one another. According to a variant not shown of the invention, the rings 4, 104 and 204 can be replaced by one or more metal studs capable of cooperating with magnets in order to create a magnetic loop by reducing the electrical capacity of the nozzle. A mixed variant with magnets and coupling pads provided on both the barrel and the nozzle can also be envisaged.

Claims

1. Device for spraying liquid or powdery coating product, said device comprising a barrel, inside which is defined a coating product circulation duct, and a nozzle for shaping the product jet intended to be mounted on said barrel, characterized in that it comprises means (4, 6; 104, 105; 204, 206) of magnetic coupling (F) between said nozzle (3; 103; 203) and said barrel (1; 101; 201) , and in that said magnetic coupling means are isolated from said conduit (2; 102).

2. Device according to claim 1, characterized in that said nozzle (3, 103) is provided with a ring (36; 136) forming a peripheral partition of a part (32; 123) of said conduit (2; 102) , said ring being disposed between said conduit and said magnetic coupling means (4, 6; 104, 106).

3. Device according to one of claims 1 or 2, characterized in that said barrel (1; 101) is equipped with at least one magnet (6; 105) capable of cooperating with a magnetic looping element (4; 104 ) carried by said nozzle (3; 103).

4. Device according to one of claims 1 or 2, characterized in that said nozzle (203) is equipped with at least one magnet (206) capable of cooperating with a magnetic looping element (204) carried by said barrel ( 201).

5. Device according to one of the preceding claims, characterized in that said coupling means (204, 205) are located around said barrel (201).

6. Device according to one of claims 3 to 5, characterized in that said looping means is a metal ring (4; 104; 204) centered on a longitudinal axis of said conduit (2; 102) and said nozzle (3 ; 103; 203).

7. Device according to one of the preceding claims, characterized in that it comprises means (11, 38; 201e, 203i) for mechanical centering of said nozzle (3; 103; 203) on said barrel (1; 101; 201), said centering means being able to allow a relative pre-positioning of said means of magnetic coupling during mounting (F ₂ ) of said nozzle on said barrel.

8. Device according to one of the preceding claims, characterized in that said means (104, 105) of magnetic coupling form contacts of a circuit (134, 141, 152) for supplying voltage to means (135) of electrostatic charge of said product provided in said nozzle (103).

9. Device according to claim 8, characterized in that said contacts are formed by one end of a magnet (105) and by a magnetic looping element in the form of a metal ring (104).

10. Device according to one of the preceding claims, characterized in that it comprises controlled means (160; 260) of injection (F ₃ ) of a separation fluid between said barrel (101; 201) and said nozzle (103; 203), with sufficient pressure to overcome the coupling force (F _x ) of said coupling means (104, 105; 204, 206).

11. Device according to claim 10, characterized in that said control means (260) for injecting (F ₃ ) a separation fluid are mounted in or on said device, preferably in or on said barrel (201).

12. Device according to one of the preceding claims, characterized in that said coupling means (4, 6; 105, 104; 204, 206) are removably installed on said barrel (1; 101; 201) and / or on said nozzle (3; 103; 203).