EP1305118A1

EP1305118A1 - Device for supplying a powdery coating product to a sprayer and spray installation comprising same

Info

Publication number: EP1305118A1
Application number: EP01960858A
Authority: EP
Inventors: Michel Di Gioia; François VASSEUR
Original assignee: Sames Technologies SAS
Current assignee: Sames Kremlin SAS
Priority date: 2000-08-02
Filing date: 2001-08-01
Publication date: 2003-05-02
Anticipated expiration: 2021-08-01
Also published as: AU2001282254A1; FR2812566A1; WO2002009886A1; DE60103281T3; US20040020535A1; DE60103281D1; DE60103281T2; EP1305118B1; EP1305118B2; FR2812566B1; US6908048B2; JP2004504935A

Abstract

The invention concerns a device (10) for supplying a powdery coating product to a sprayer (1) in an installation spraying such a product. The invention is characterised in that it comprises at least two modules (11, 14) connected each to a source (B1-B4) of coating product and forming each part (112, 113) of a common manifold (C) connected to said sprayer (1) for circulating said product (P1-P4).

Description

DEVICE FOR SUPPLYING POWDER COATING PRODUCT TO A PROJECTOR AND PROJECTION INSTALLATION COMPRISING SUCH A DEVICE

The invention relates to a device for supplying powdery coating product to a projector and to a plant for spraying coating product powder, comprising, among other things, such a device. In the field of installations for spraying powdery coating product, it is known to supply each projector of an installation with a mixture of coating product and a conveying gas which is most often air. In some installations, a floodlight must be supplied with several types of coating product which are selectively used, depending on the nature of the coating to be produced. Thus, in the case of an installation for spraying coating product on motor vehicle bodies, it is necessary to plan to paint each bodywork according to the color chosen by the customer.

By FR-A-2 441 435, it is known to converge lines connected to different reservoirs of powdered product to a distributor in which they are arranged in a cone. The spatial distribution and the number of these lines are imposed by the geometry of the distributor. It is thus necessary to provide different types of distributor depending on the number of coating products to supply the projector. In addition, complex systems for cleaning the various pipes and distributors must. be planned.

This device has a size such that it must necessarily be placed at a distance from the projector which it supplies, so that the pipe connecting the distributor to the projector must be cleaned during each change of product over a relatively long distance, which increases the amount of product lost and the time for product change. It is to these drawbacks that the invention more particularly intends to remedy by proposing a supply device which makes it possible to supply a projector with at least two types of powder coating product, this device being easily adaptable to the number of products to be use and can be easily exchanged.

In this spirit, the invention relates to a device for feeding a projector with a powdery coating product, this device comprising at least two modules each connected to a source of coating product and each forming part of a common collector. connected to the projector for product circulation.

Thanks to the invention, the modular structure of the device of the invention makes it possible to adapt the number of modules used to the number of different sources of coating product, the common collector being created, as the addition of additional modules, by the modules themselves. The modular structure of the device of the invention makes it possible to give it relatively small dimensions allowing it to be installed as close as possible to a projector, in particular at the level of an arm of a robot moving the projector opposite the objects to be coated. The length of pipe to be cleaned downstream of this device, during each change of coating product, is short, which is advantageous in terms of quantity of product lost and time of product change.

According to advantageous but not compulsory aspects of the invention, the device incorporates one or more of the following characteristics: - it comprises a cleaning module connected to a source of cleaning fluid and forming an upstream part of the common collector.

- Each module comprises at least one valve capable of selectively placing in communication an input of the module, connected to the source of product or cleaning fluid, and the collector. Such a valve makes it possible to control each module so that it delivers or not coating product or cleaning fluid to the common collector and that it supplies so or not the projector.

each module comprises a conduit connecting an input of the module to the part of the collector formed by this module while the collector formed by the different modules extends in a first direction and that the conduit of each module extends in a second direction , the angle between these directions, taken according to the direction of flow of the product in this conduit and this collector, being an acute angle. This geometry of the modules allows an easy transition of the flow of the mixture of entrainment gas and coating product between the duct and the part of the manifold formed in each module.

the modules are assembled in a reversible manner, their number being able to be adapted to the number of sources of coating product to which the projector must be connected.

each module comprises a basic element in which the part of the collector is formed and a zone for joining the collector with a conduit. Each module also includes a connection element defining the inlet of the conduit and a valve for controlling the flow of the product in the conduit, this valve being disposed between the base element and the connection element. Each module is thus formed of two essential elements and a valve trapped between these elements and protected from the outside by them.

According to an advantageous embodiment of the invention, at least one of the modules forms a first supply duct for the collector and a second supply duct for a recirculation channel for the coating product, these first and second ducts extending from a common module input. In this embodiment, a circulation of the mixture of entrainment gas and of powdery coating product can be maintained continuously up to each module, the mixture of air and powder being directed either to the supply manifold of the projector, or towards the recirculation channel. This avoids the transient regimes of setting in motion of the powder as well as the cleaning of the supply conduits of each module. This embodiment is therefore particularly advantageous with regard to the time for changing the coating product and minimizing the quantities of product lost during a change. In this case, it can be provided that the first and second conduits are each equipped with a controlled valve capable of allowing and / or interrupting the flow of the coating product in the considered conduit.

The valves used are advantageously sleeve valves which have the particular advantage of operating without hindrance in a relatively aggressive environment, that is to say in contact with a mixture of air and powder.

The invention also relates to an installation for spraying powdery coating product which comprises at least one projector powered by a device as previously described. Such an installation is economical to manufacture, due to the modular nature of the device, and to operate, due to the minimization of the quantities of coating product lost and the time of rapid color change. Such an installation easily adapts to variations in its conditions of use, in particular to the number of coating products capable of supplying each projector.

The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of two devices for supplying coating product integrated into a spraying installation in accordance with its principle, given only by way of example and made with reference to the accompanying drawings in which: - Figure 1 is a schematic representation, with partial cutaway, of a coating product spraying installation according to a first embodiment of the invention;

- Figure 2 is an exploded perspective view, with cutaway of a module of the supply device used in the installation of Figure 1;

- Figure 3 is an exploded perspective view of a sleeve valve used in the module of Figure 2; - Figure 4 is a side view of the supply device used in the installation of Figure 1;

FIG. 5 is a view similar to FIG. 1 for an installation according to a second embodiment of the invention, and

- Figure 6 is a side view of the supply device used in the installation of Figure 5.

The installation shown in FIG. 1 comprises a headlamp 1 of the manual type intended to project a cloud 2 of a mixture of entrainment gas and of powdery coating product onto objects to be coated 3. The headlamp 1 is of the electrostatic type and is connected to a high voltage unit 4 by means of a conductive cable 5.

The projector 1 is also supplied with a mixture of entrainment gas and of powdery coating product by means of a flexible pipe 6 connected to a device 10 enabling it to be supplied selectively with one of four products Pi, P2, P3 and P4 respectively contained in four tanks Bi, B2, B3 and B4 and pumped thanks to suction systems with Venturi effect Vi, V2, V3, V4. The device 10 is connected to each Venturi Vi to V4 by a pipe Ti to T4.

The device 10 comprises four modules 11, 12, 13, 14, the modules 11 and 12 being represented in FIG. 1 with a half cut away, while the module 13 is represented with a cutout of a quarter and that the module 14 is shown without tearing. The device 10 comprises a fifth module 15 connected to a source S of pressurized air by a pipe T5. The device 10 also includes a head 16 from which extends a connection element 16a intended to cooperate with the pipe 6.

We denote X-X 'the axis of symmetry of the element 16a. The modules 11 to 15 and the head 16 are juxtaposed along the axis XX '.

The module 11 comprises a base element 111 in which is formed a channel 112 which extends, in the mounted configuration of the device 10, in the direction of the axis XX ′ crossing right through the element 111.

The module 11 also includes a second element 113 carrying a connecting element 113a with the pipe Ti. The internal volume of the element 113 defines, with the element 111, a conduit 114 of generally cylindrical shape and of which we denote YY 'the central axis. The conduit 114 extends into the element 111 up to a junction zone 115 with the channel 112. In other words, the conduit 114 opens into the channel 112 at the level of the zone 115.

114A denotes the upstream part of the conduit 114 formed in the element 113 and 114B its downstream part formed in the element 111 and terminate in the zone 115. A sleeve valve 116 is disposed in the conduit 114, both in the parts 114A and 114B. In fact, the valve 116 is arranged between the elements 111 and 113.

The structure of the valve 116 is shown more particularly in FIG. 3. This valve comprises a tubular element 116A pierced with two radial orifices 116B and inside which is disposed an elastic sleeve 116C held in place in the element 116A by with two 116D rings. When an air circulation is to take place in the duct 114, the sleeve 116C remains pressed against the internal surface of the element 116. When the circulation in the duct 114 has to be stopped, a control air pressure is applied to the sleeve 116C through the orifices 116B, as represented by the arrow F _x in FIG. 1, which has the effect of pinching the sleeve 116C and thus cutting off the flow in the conduit 114. An orifice 113b visible in FIG. 4 is provided in the element 113 for the supply of control air to the valve 116.

The modules 12, 13 and 14 are identical to the module 11 and each formed of a basic element 121, 131 or 141 and of a connection element 123, 133 or 143. Each module 12, 13 and 14 also includes a valve sleeve 126, 136 or 146.

The element 121 defines a channel 122 which is generally aligned with the channel 112, along the axis XX ′, in the mounted configuration of the device 10. In the same way, the modules 13 and 14 each define a channel 132, 142 also aligned on the axis XX 'and with an axial passage 162 of the head 16. The elements 112, 122, 132, 142 and 162 thus form a manifold C through which an air / powder mixture coming from one of the pipes Ti to T4 can flow through the pipe 114 or one of the equivalent pipes 124, 134 or 144 of the modules 12, 13 and 14.

The module 15 also defines a conduit 154 which opens into a channel 152 aligned with the channel 142 of the module

14 in the mounted configuration of the device. The module 15 is also equipped with a sleeve valve 156 making it possible to open or close the conduit 154.

When the valve 156 of the module 15 is open, while the valves 116, 126, 136 and 146 are closed, air flows from the source S towards the projector

I by successively crossing the channels 152, 142, 132, 122, 112 and the passage 162, as well as the element 16A and the pipe 6. This makes it possible to clean the device 10, the pipe 6 and the projector 1 in a particularly simple manner and fast.

The elements 11 to 16 are held in the form of a mechanical unit by means of two threaded rods 17 and 17 'which pass through the basic elements 111 and equivalent and the basic element 151 of the module 15 as well as the head 16. The head 16 and module 15 are also each provided with two screws 18 allowing the mounting of element 10 on a plate, not shown.

The modular nature of the device 10 makes it possible to adapt the number of modules, 11 or equivalent, to the number of coating products to be supplied to the projector 1. For example, if an additional coating must be used in the installation of FIGS. 1 to 4, it suffices to insert between the module 11 and the head 16 a module identical to the module

II and to change the rods 17 and 17 'to use rods of suitable length. The fact that each module 11 or equivalent constitutes a part of the common collector C therefore makes it possible to permanently adapt the length of this collector to the effective number of modules used.

The arrow F _{2 represents} the flow of a mixture of entrainment gas and coating product in the conduit 114. The arrow F _{3 represents} the flow of coating product in the channel 112. The arrow F ₂ is arranged in the direction YY 'and oriented towards the channel 112 while the arrow F ₃ is arranged in the direction of the axis XX 'and towards the head 116. The angle between the directions of the arrows F ₂ and F ₃ is of the order of 45 °, so that the change of direction of the flow in the zone 115 is not too abrupt, which avoids an accumulation of powder in this zone and a possible "ascent" of the mixture towards the modules 12 and following.

In practice, two cases can be considered, the angle o. varying from 20 ° to 90 °. - For powders which are relatively easy to transport in an air flow, the smaller the angle a, the lower the pressure drops at the level of the zone 115. The angle a is chosen between 20 and 45 °, the value of 20 ° being a minimum for a reason of mechanical design while the value of 45 ° corresponds to a maximum slope for a smooth flow. The powder flow used can then be significant. for powders that are relatively difficult to transport, agglomerates formed by melting the powder in zone 115 should be avoided. To do this, the speed of the air / powder mixture and the disturbances generated by a marked angle α are favored. example between 45 ° and 90 °. Such an angle prevents the powder from depositing in the zone 115. In an unfavorable case where a slight deposit comes to form, it would be evacuated by the air / powder mixture arriving next. The choice of the values of the angle a is then made at the expense of the maximum flow rate and can generate powder flows upstream of the collector C.

In the second embodiment of the invention shown in FIGS. 5 and 6, elements similar to those of the first embodiment bear identical references increased by 200.

The projector 201 of this embodiment is an automatic projector supported by the arm 207 of a robot. A device 210 is provided for supplying the projector 201 from two tanks Bi, B2 each containing a coating product Pi, respectively P2, and equipped with a Venturi Vi drive system, respectively V2. The device 210 comprises a first module 211 shown with a half cut away and a module 212 shown in external view, as well as a cleaning module 215 connected to a source S of pressurized air. The modules 211 and 212 are respectively connected by a pipe Ti, T2 to the Venturi devices Vi and V2, while the module 215 is connected to a source S of pressurized air by a pipe T5. -

The module 211 comprises a basic element 2111 in which is formed a channel 2112 extending essentially in the direction of an axis XX ′. The basic element 2121 of the module 212 also defines a channel 2122 which is aligned with the channel 2112 in the mounted configuration of the device. The cleaning module 2115 defines, for its part, an end part 2152 of the channel in its base element 2151. A head 216 constitutes the downstream part of the device 210 and is provided with a passage 2162 which is aligned with the channels 2112, 2122 and 2152 thereby forming a collector C for the coating product coming from a conduit 2114 of module 211, bu from a conduit 2124 of module 212.

The cleaning module 215 is also provided with a pipe 2154 making it possible to inject cleaning air coming from the source S into the upstream part 2152 of the manifold C. Each pipe 2114 or 2124 is equipped with a sleeve valve 2116 or 2126.

As before, the valve 2116 is controlled by air injection, as shown by the arrow Fi in FIG. 5. In parallel to the conduit 2114, a conduit 2117 extends, starting from the inlet 2113a of an element of connection 2113 of the module 211 up to the base element 2111. This channel comprises an upstream part 2117A formed in the element 2113 and a downstream part 2117B formed in the element 2111, a sleeve valve 2118 being housed in this conduit, between elements 2111 and 2113.

The downstream part of the duct 2117 is bent at about 90 °, so that it can supply a connection element 2111a connected to the tank Bi by a pipe T'i for recirculation. The duct 2117 could also be bent with an obtuse angle, the choice of the value of this angle being able to be made according to the nature of the powder, as indicated above with reference to the angle a.

We note 2113b the conduit in which the control air is injected around the flexible part of the sleeve valve 2116, as represented by the arrow-Fi. 2113'b denotes the channel, also formed in element 2113, through which control air is injected around the sleeve valve 2118, as shown by the arrow F ' _x .

The operation is as follows: From a branch 2113c. between the ducts 2114 and 2117, the mixture of air and entrainment gas coming from the tank Bi through the pipe Ti is directed either to the channel C, through the duct 2114 and the valve 2116, or to the pipe recirculation T'i through the channel 2117, the valve 2118 and the connection element 2111a.

The sleeve valves 2116 and 2118 are controlled, as shown by the arrows Fi and F'i, to be open and closed in phase opposition, one of these valves being open when the other is closed. Coating product can circulate permanently in the pipe Ti while being directed either towards the collector C, or towards the pipe T'i. Thus, when it is necessary to use a new Pi or P2 product, no transitional phase of setting in motion the entrainment gas / product mixture should be provided, the time of change of coating product between the Pi products and P2 is thus very fast. The second module 212 is produced in the same way and makes it possible to recirculate the coating product P2 in the direction of the tank B2 by means of a pipe T'2.

As previously also, the modules 211 and 212 are assembled reversibly by means of threaded rods 217 and 217 '. It is thus possible to adapt the number of modules of the device 210 to the number of coating products to be used.

The module 210 is particularly compact and, at this As such, it can be mounted on the arm 207 of the robot supporting the projector 201. Thus, the length of the pipe 206 connecting the device 210 to the projector 201 can be minimized, which also makes it possible to minimize the quantities of coating product lost during 'a change of product, these amounts corresponding approximately to the amount of coating product in the manifold C and in the conduit 206. The small volume of the pipe 206 also facilitates its rapid cleaning. A mixed installation with one or more modules of the module 11 type and one or more modules of the module 211 type can be envisaged, as can a combination of modules whose conduits have angles of inclination a different from the main direction of collector C.

Claims

. CLAIMS

1. Device for supplying powdery coating product to a projector of an installation for projecting such a product, ^' characterized in that it comprises at least two modules (11-14; 211, 212) each connected to a source

(B1-B4) of coating product and each forming a part

(112-142; 2112, 2122) of a common collector (C) connected to said projector (1; 201) for the circulation (F ₂ , F3) of said product (P1-P4).

2. Device according to claim 1, characterized in that it comprises a cleaning module (15; 215) connected to a source (S) of cleaning fluid and forming an upstream part (152; 2152) of said common collector (C ).

3. Device according to one of the preceding claims, characterized in that each module (11-15; 211, 212, 215) comprises at least one valve (116, 126, 136, 146, 156; 2116, 2126, 2156) able to selectively put in communication an input of said module, connected to said source (Bι-B4, S) of product (P1-P4) or of cleaning fluid, and said collector (C).

4. Device according to one of the preceding claims, characterized in that each module (11-15 .; 211, 212, 215) comprises a conduit (114, 124, 134, 144, 154; 2114, 2124, 2154) connecting an input from said module to the part (112,122, 132, 142; 2112, 2122, 2152) of said collector (C) formed by said module, said collector formed by said modules extending in a first direction (X-X ') then that said conduit of each module extends in a second direction (Y-Y '), the angle (a) between said directions, taken in the direction of flow (F2, F3) of the product in said conduit and said manifold , being an acute angle.

5. Device according to one of the preceding claims, characterized in that said modules (11-15; 211, 212, 215) are assembled reversibly, their number being able to be adapted to the number of sources (B1-B4) of product covering (P1-P4) to which said headlight (1; 201).

6. Device according to one of the preceding claims, characterized in that each module (11-15; 211, 212, 215) comprises: - a basic element (111, 121, 131, 141; 2111,

2121, 2151) in which is formed said part (112, 122, 132, 142, 152; 2112, 2122, 2152) of said manifold (C) and a junction zone (115) of said manifold with a conduit (114, 124, 134, 144; 2114, 2124, 2154) connected to a source (Bl-B4, S) of coating product (P1-P4), or of cleaning fluid in the case of a cleaning module,

- a connection element (113, 123, 133, 143; 2113) defining the inlet (113a; 2113a) of said conduit and

- A valve (116, 126, 136, 146; 156; 2116, 2126, 2156) for controlling the flow of said product in said conduit, said valve being disposed between said base element and said connection element.

7. Device according to one of the preceding claims, characterized in that at least one (211, 212) of said modules forms a first conduit (2114) supplying said collector (C) and a second conduit (2117) d supply of a recirculation channel (T'i, T'2) of said coating product (Pi, P2) to a source (Bi, B2) of product (Pi, P2), said first and second conduits extending from a common input (2113a) of said module.

8. Device according to claim 7, characterized in that said first and second conduits (2114, 2117) are each equipped with a valve (2116, 2118) controlled capable of allowing and / or interrupting the flow of coating product in the conduit considered.

9. Device according to one of claims 3, 6 or 8, characterized in that said valve (116, 126, 136, 146, 156; 2116, 2118, 2126, 2156) is a sleeve valve.

10. Installation for spraying powdery coating product comprising at least one projector (1; 201) supplied by a device (10; 210) according to one of the preceding claims.