FR2880557A1 - INDUSTRIAL PAINT INSTALLATION - Google Patents

Abstract

The invention relates to an industrial paint installation comprising a painting booth (3) comprising at least one opening (19) of diffusion flux inlet and at least one opening (13) for recovering the powder of an atomized powder in excess. , characterized in that it comprises a color box magazine (21) each comprising a powder reservoir (25), at least one propellant flow inlet mouth (34), at least one diffusion outlet mouth ( 35), supply means for each color powder propellant flow, a filter chamber (26) provided with a filter arranged between at least one suction mouth for the application of a suction flow and at least one salvage mouth. Each color box is adapted to be coupled, directly and removably, to the paint booth, each outlet outlet mouth -respectively mouth-recovery of said box being arranged in correspondence with a diffusion inlet opening - respectively recovery opening- of the cabin so as to be contiguous thereto.

Description

INDUSTRIAL PAINT INSTALLATION

  The invention relates to an industrial paint installation for painting objects with a colored powder, said colored powder being applied to an object by spraying, in the form of a suspension of powder in a gas (air) . The installation according to the invention is for example intended for the painting of elongated objects such as sheets, beams, metal profiles, and especially profiles used in the manufacture of joinery (window, French window ...) etc. or any other object (of any form).

  Known painting installations usually comprise a paint station and a conveyor of objects, generally arranged in the upper part of the installation so as to pass above the paint station.

  Known paint stations include a painting booth, open on the one hand in the upper part facing the conveyor objects, and secondly at both ends, for the passage of suspended objects; the objects conveyed by the conveyor thus cross said cabin, from one end to the other of the latter, for painting. The cabin is equipped with spray guns or nozzles capable of projecting a gaseous flow (air for example) loaded in color powder, said diffusion flux, towards a central zone of the cabin so as to generate, around the object to be painted, a mist of colored powder that the paint booth can confine.

  The color powder intended to feed the diffusion flux is stored in a powder reservoir, generally associated with a fluidization chamber in which a bed of fluidized powder is created from a quantity of powder from the reservoir and from a reservoir. airflow projected into the chamber through a suitable membrane. The fluidized powder bed is sucked from the fluidization chamber by means of a pump, and the resulting diffusion stream is conveyed to the spray nozzles of the spray booth by one or more conduits, possibly equipped with pumps. additional.

  The excess powder sprayed in the paint booth is recovered and filtered, on the one hand for recycling, and on the other hand to facilitate the cleaning of the spray booth. To this end, the installation comprises one or more filtering devices (filter, cyclone ...) arranged near the paint booth, and suction means capable of generating a suction stream and / or a depression in the spray booth to recover excess powder. The recovery stream (gaseous flow generated by the suction means, loaded with colored powder recovered in the cabin) is conveyed to the filtering devices in order to separate the color powder, which, at the output of the cooling devices, filtering, is returned to the powder tank.

  In the event of a change of color, it is necessary, before the new powder is sprayed, to clean not only the inside of the paint booth but also all the ducts and devices of the installation exposed to the colored powder, in order to avoid any pollution of the new powder by the old.

  This cleaning is particularly long. It proves to be extremely expensive both in terms of labor and business interruption. Indeed, a large part of the operations necessary for cleaning the installation is still done manually, and this cleaning results in immobilization of the entire paint installation.

  Various solutions have been proposed to minimize the impact of the cleaning of the installation, and in particular the devices and ducts attached to the paint booth, during a color change.

  Thus, US 4,245,551 describes an installation comprising a removable filter module, interposed between an air outlet of the paint booth and a suction module. The filter module is mounted on wheels; it is replaced with each change of color, so that this part of the installation is not to be cleaned during a color change. However, many powder transport pipes (including the recycling ducts between the filter module and the powder tank and the supply ducts between the tank and the paint booth) remain to be cleaned during the color change.

  US 2002/0157604 proposes a specific arrangement (position of the entrances and exits, removable sections ...) of the spray booth, excess powder pulverization recovery pipes, separation cyclones and filter cartridges, recycling ducts. filtered powder, etc.

  WO 02/074442 recommends on the one hand to use a vacuum pump to transport the color powder recovered and filtered between the cyclone and a collector receptacle directly feeding a feed hopper powder, to shorten the time of stay of the powder in these devices, and secondly to circulate the powder in tense flow in substantially linear ducts and no elbow, to limit the powder deposits in these conduits.

  WO 01/19529 discloses an installation comprising a one-piece assembly arranged between the powder supply device (reservoir and fluidization chamber) and the spray nozzles of the cabin, which assembly comprises a suction tube stage, a stage of pumps and powder dispensing ducts. This assembly is slidably mounted between a first diffusion or cleaning position, in which, as the case may be, the suction tubes are connected to the fluidization chamber of the powder supply device or to a purge device, and a second position for disconnecting the suction tubes from the powder supply device or the purge device for the purpose of reversing the latter (during a color change). Furthermore, the installation comprises filter cyclones equipped with both access hatches to facilitate their cleaning, a lower fluidization chamber for the recovered powder and a recycling pipe in which the fluidized powder circulates through gravity.

  Despite the proposed solutions, it takes no less than 15 minutes of immobilization in the most efficient painting facilities, and more generally one to two hours, to make a color change.

  This is why the production is organized by batch of objects intended to receive the same color and the proposed color ranges are voluntarily reduced, in order to limit the number of color changes to be made. In particular, it is impossible to adapt the production in real time to the orders received, which penalizes delivery times.

  In addition, previous installations are particularly cumbersome. The known paint stations (including the spray booth, the cyclone filtering devices, filters the tank color powder feeder, fluidization chamber, pump all of the supply lines of the powder booth and excess powder spray recovery and recycling ducts, etc.) generally occupy a large floor area in the case of carpentry profile painting installations with a cross-sectional area of only a few square centimeters.

  The invention aims to overcome these disadvantages by proposing a radically different paint installation, of smaller size and in which the cleaning operations of the installation are extremely reduced, greatly simplified and can be fully automated. The invention also provides a new, extremely simple and fast color changing method.

  The invention aims in particular to provide a new installation in which only the paint booth is possibly to be cleaned during a color change. In other words, the invention makes it possible to reduce the cleaning operations of the entire installation by simply cleaning the paint booth.

  In a preferred version, the invention even aims to provide a paint installation in which the cleaning of the painting booth is carried out in masked time, and in which a color change only induces immobilization of a few seconds of installation.

  Another object of the invention is to provide a space-saving installation in order to further reduce operating costs (by reducing the size of the premises hosting the installation).

  Another object of the invention is to provide a paint installation that can offer a wide range of colors.

  In a preferred version, the invention also aims to allow the production of complex paints (several layers of different colors for the same object) on a case by case basis, and in particular for an isolated object or for a small number of objects possibly scattered in production, without this specific treatment penalizing the productivity of the chain.

  In a preferred version, the invention also proposes a new painting method which not only simplifies the color change operations, but is also at least as fast as the previous processes and provides qualitative results (maximum covering of the object, equal thickness of the paint layer ...) at least as satisfactory.

  The invention also aims to increase the recycling rate of the color powder.

  Finally, the invention aims to achieve all these objectives at a lower cost, by providing an inexpensive installation and the possibility of offering painted objects of low cost, regardless of the number of color changes to be made for a given order and the quantity of objects intended to receive the same color.

  The invention relates to an industrial installation of paint for painting objects by means of at least one gaseous flow loaded with color powder, said diffusion flux, projected on each object, said installation comprising a paint station comprising a cabin of paint containing a containment casing of the projected diffusion stream (s), at least one orifice, said spray orifice, directed towards the interior of the painting booth, for the projection of the diffusion flux, at least one opening, said diffusion inlet opening, opening on the outside of the painting booth for the entry of a diffusion flux, each spray orifice being connected to an opening diffusion inlet, at least one opening, said recovery opening, opening on the outside of the paint booth and communicating with the interior of said booth, and through which a current can be produced at the inside the ca for the recovery of the powder powder in excess, characterized in that: the installation comprises a box magazine, said color boxes, each containing a color powder, each color box comprising an outer casing, inside said outer casing, a reservoir of colored powder, at least one mouth, said mouth of flow of propellant, opening on the outside of the outer casing and adapted to be connected to a generating device a gas flow, said propellant flow, capable of conveying color powder, at least one mouth, said diffusion outlet mouth, opening on the outside of the outer casing, supply means, between each propellant inlet mouth and a diffusion outlet mouth, the powdered propellant gas stream coming from the reservoir, to form a diffusion flux, inside the outer casing, a chamber, called chamber of diffusion, ltering, provided with at least one filter capable of retaining at least a portion of the color powder, at least one mouth, said suction mouth, opening on the outside of the outer casing and communicating with the interior the filter chamber, said suction mouth being adapted to be connected to a device for generating a suction gas flow, at least one mouth, said mouth of recovery, opening on the outside of the outer casing and communicating with the inside of the filter chamber, the filter being arranged in such a way that the suction stream (s) produces a gaseous flow inside the filter chamber; , said suction stream, passing through the filter from each recovery mouth to a suction mouth, - each color box is adapted to be coupled, directly and removably, to the paint booth, each mouth of broadcast output of said b color box being arranged in correspondence with a diffusion opening opening of the paint booth so as to be contiguous thereto when the color box and the painting booth are coupled, each recovery mouth of said box of paint color being arranged in correspondence with a recovery opening of said paint booth so as to be contiguous thereto when the color box and the painting booth are coupled.

  Thus, the invention consists in grouping all the devices and ducts necessary for supplying the color powder coating booth to a single removable casing in the installation, and all devices and conduits necessary for the recovery and filtering (and possibly recycling) of excess powder powder in the cabin.

  All the elements of the installation exposed to the colored powder are thus united in the color box and in the paint booth.

  Each diffusion stream created inside the color box, by the meeting of a propellant flow (virgin powder) introduced into the color box and a quantity of color powder from the tank of the box, is directly transmitted from the color box to the paint booth, whose respective outlet mouth (s) and outlet opening (s) are contiguous. No conduit is provided between the color box and the paint booth for the diffusion stream booth. Likewise, each excess powdered powder recovery stream is directly transmitted from the paint booth to the color box, the respective recovery openings and mouth (s) of recovery are contiguous.

  No conduit is provided between the paint booth and the color box for the recovery of excess powder powder. Downstream of the recovery, the air leaving the color box (and corresponding to the suction flow (x) imposed (s) at the (or) suction mouth (s) of the box) is virgin powder or almost virgin, as will be explained later since the suction current produced through the mouth (s) and opening (s) of recovery respectively of the color box and the paint booth passes through the filter (or possibly filters) from the filter chamber before leaving the color box.

  Thus, when changing colors, simply replace the color box formerly used by another color box and clean the paint booth. The invention extends to a color change method in an installation as defined above, in which the color box initially coupled to said cabin is uncoupled from the paint booth, the interior of the paint booth is cleaned. another color box is coupled to the cleaned cabin. The only part of the installation to be cleaned during a color change is the paint booth, which can be done manually or automatically in less than 5 minutes.

  Color boxes do not require cleaning, since each box is permanently assigned a color. By considerably reducing the impact of a color change on the productivity of the chain, the invention offers the possibility of offering a wide range of colors.

  Advantageously and according to the invention, each color box comprises at least one conduit, called recycling conduit, connecting the filter chamber and the powder reservoir for recycling the recovered powder and filtered in the filter chamber.

  Advantageously and according to the invention, the recycling duct has an orifice, said recycle flow orifice, communicating with the outside of the outer casing and adapted to be connected to a device for generating a gas flow, said flow of recycling, able to convey the color powder for transport in the recycling line to the tank, the recovered powder and filtered in the filter chamber.

  It should be noted that it may be advantageous to equip the filtering chamber with a filter capable of allowing the finest powder particles to pass through, which it is undesirable to recycle and recover in the diffusion stream. . In this case, the air leaving the color box (suction flow) may contain a small amount of powder particles. The installation then advantageously comprises an additional independent filtering module, which is arranged between the color box and the suction flow generation device, in order to be able to discharge into the atmosphere an air perfectly purified of any powder. . Given the fact that the powder recovered in this module is not recycled, it does not matter that this module is soiled by powders of different colors. It is therefore not necessary to replace this module with each color change, or even to clean it. However, it can be replaced periodically for cleaning, to prevent clogging of the filter. Since the amount of powder recovered in this module is small, this replacement does not have to be done frequently.

  Advantageously and according to the invention, each diffusion opening opening of the paint booth is provided with a sealing member (seal for example) adapted to ensure a gas-tight coupling of said opening and a mouth of broadcast output of a color box; likewise, each recovery opening of the paint booth is provided with a sealing member adapted to ensure a gas-tight coupling of said opening and a recovery mouth of the color box. Alternatively or in combination, each diffusion outlet mouth and each collection mouth of each color box are provided with such sealing members.

  Advantageously and according to the invention, each color box comprises an access port to the powder reservoir, closed by a removable cap, to allow filling of the reservoir when the amount of powder it contains comes to exhaustion. Thus, the color boxes are not consumables of the installation, which allows to limit the costs of production.

  Advantageously and according to the invention, the painting booth comprises at least one face, said plane coupling face, in which are provided at least one diffusion opening 30 and at least one recovery opening, the outer casing of each color box comprises a face, called the coupling face, flat, conjugate of each coupling face of the paint booth, and in which are formed each outlet mouth of diffusion and each mouth of recovery of the color box so as to correspond to the opening (s) of diffusion and opening (s) of recovery of a coupling face of the paint booth.

  The coupling of a color box and the painting booth is carried out simply by contacting their coupling faces (note that this is also the case in a general version of the invention where the face of the coupling is not necessarily flat or may even be formed of several faces). Means for fixing the color box on the paint booth (or conversely) in this coupling position are advantageously provided.

  Advantageously and according to the invention, each color box comprises, for each diffusion outlet mouth, a conduit, called diffusion duct, connecting said diffusion outlet mouth to a propeller flow inlet mouth (in others in other words, it is the conduit in which the diffusion flux is formed). It should be noted that, preferably, each diffusion outlet mouth is connected to one (and only one) propellant flow inlet mouth which is its own, by a diffusion duct proper to said mouths. As a variant, two diffusion outlet outlets may be connected to one and the same thrust flow inlet mouth by two diffusion ducts having a common upstream section. Conversely, a diffusion outlet mouth can be connected to two thrust flow inlet mouths, by two diffusion ducts having a common downstream section.

  Advantageously and according to the invention, each diffusion duct is arranged outside the reservoir and the reservoir has, for each diffusion duct, a piercing, said supply piercing, opening on the diffusion duct with a view to the powder feed of the propellant gas stream.

  Furthermore, the spray booth preferably comprises, for each spray orifice, a conduit, called a spray pipe, connecting said spray orifice to a diffusion inlet opening. It should be noted that preferably each spray orifice is connected to a single diffusion inlet opening of its own by means of a clean spray pipe to said orifice and opening. In a variant, two spray orifices may be connected to the same diffusion inlet opening by two spray pipes having a common upstream section. Conversely, a spray orifice may be connected to two diffusion inlet openings by two spray pipes having a common downstream section.

  Advantageously and according to the invention, each color box comprises, for each diffusion conduit, a tube, called a tribostatic tube, made of a material with a tribostatic effect such as PTFE (polytetrafluoroethylene), arranged in the powder reservoir so as to be able to collecting color powder and electrically charging the collected powder, which tribostatic tube passes through the feed bore to open into the diffusion conduit. Each tribostatic tube preferably forms at least one loop within the reservoir.

  Alternatively or in combination, each spray pipe of the paint booth is made of a tribostatic material such as PTFE; it has a length and a shape adapted to be able to electrically charge the powder carried by the diffusion flux.

  Meanwhile, the spray booth is advantageously adapted to receive and spray electrostatic powder color, the use of which is widely used: the booth is for example provided, at each of its spray orifices, an electrode connected to a voltage source so as to generate an electric field between said electrode and an object disposed inside the cabin and connected to a mass. The object is for example connected to the earth (mass) via the object conveyor to which it is attached.

  Thus, the installation according to the invention makes it possible to use both tribostatically activated color powders and electrostatic color powders. These are stored in color boxes without tribostatic tubes.

  Advantageously and according to the invention, each color box comprises a color powder flow metering device supplying each propellant flow, that is to say each diffusion duct (or each diffusion outlet mouth). The metering device is preferably a volumetric dosing device integrated (at least in large part) into the tank of the color box.

  Advantageously and according to the invention, the outer casing of each color box is parallelepiped, in order to facilitate the storage of color boxes in the store.

  Advantageously and according to the invention, for each color box: the reservoir has at least one plane face; preferably, the reservoir is parallelepipedal, the filtering chamber has at least one plane face facing the flat face of the reservoir; preferably, the filtering chamber is generally parallelepipedal, - the color box comprises a distribution plate arranged between the reservoir and the filtering chamber, between their two opposite planar faces, in which are formed the (s) conduit (s) ), the propellant flow inlet mouth (s) and the diffusion outlet mouth (s).

  This construction is particularly simple and economical to achieve. It also makes it possible to optimize the powder storage capacity of each color box and the storage of color boxes in the store.

  The distribution plate is preferably formed of at least one plate having at least one slot extending from one edge to another of the plate to form a diffusion conduit, a propellant inlet mouth and a mouth broadcast output. Said slot is plugged on the faces of said plate, respectively by the flat face of the tank and the flat face of the filter chamber. Alternatively, the slot is plugged on at least one face by another plate, said closure plate (the distribution plate being in this case formed of at least two plates).

  Advantageously and according to the invention, each recovery mouth of each color box is provided with a non-return valve opening under the effect of the suction stream; Moreover, the device for generating suction flow is adapted to also generate a flow contrary to the suction flow, called unclogging flow, which produces, inside the filtering chamber, a gaseous stream of unclogging through the filter so as to separate from the filter the powder collected by it, and under the effect of which the non-return valve is closed (it closes or remains closed, according to the immediately previous situation).

  Advantageously and according to the invention, the filtering chamber of each color box comprises a screen, arranged so as to receive the powder collected by the filter. The sieve makes it possible to prevent the powder collected from the filter from forming amalgams or aggregates, which could, after recycling the powder, be reintroduced as such into a diffusion stream and form packets on the layer of paint covering the object. The screen also retains any dust caused by the flow of recovery from the paint booth.

  Advantageously and according to the invention, said screen is associated with a vibration device. This vibration device is preferably outside the box of

  color and independent thereof, for the sake of simplification of color boxes and limitation of their manufacturing cost. Thus, in a preferred version of the invention: the filter chamber has a bottom for recovering the powder at the outlet of the sieve, said bottom being secured to the recycling duct (or possibly to one of the recycling ducts) and having lights opening on the recycling duct (or on each duct, if there are several), the sieve being fixedly mounted on said recovery floor, - the recycling duct (or possibly one of the recycling ducts) ) has at least a portion, said outer portion, extending outside the outer casing of the color box, - the vibration device is independent of the color box and comprises a motorized member, said vibration member, which, when the color box is coupled to the paint booth, rests against an outer portion of the recycling duct and is adapted to impose small alternative movements to the recycling duct, and amment of displacements parallel to the plane of the sieve. The sieve being fixed on the bottom of recovery and therefore being integral with the recycling duct, the displacements imposed on said duct are transmitted to the sieve. The vibration member is for example a cam fixed on a shaft driven in rotation by a motor of the vibration device.

  Advantageously and according to the invention, the installation comprises a plurality of paint booths, each booth being adapted to be removably mounted in the paint station.

  In a preferred version of the invention particularly suitable for painting elongated objects generally cylindrical (objects which are cylindrical in the strict sense of the term that is to say generated by a line that moves parallel to itself on a directional curve and which thus have a cross section (perpendicular to the generating line) identical and of any shape throughout the length of the object or, more broadly, objects which have a slightly variable cross section along an axis longitudinal object): the installation comprises a plurality of paint booths, said containment boxes, each containment box being adapted to be traversed by an object, the housing of said confinement box having a dimension in one direction, said axial direction, much lower (for example at least three times lower) to the longitudinal dimension of the elongated object, leq uel casing comprises two through axial lumens, arranged facing each other in the axial direction of the containment box and adapted to allow the passage of the object, (each containment box having, as a paint booth , the characteristics of the cabin defined above, and in particular that, essential, to be coupled to a color box according to the invention ...) - the paint station comprises an elevator, said elevator paint, mounted slidably according to a substantially vertical direction; advantageously and according to the invention, the paint station also comprises motor, hydraulic or pneumatic or mechanical means for moving the paint elevator in its direction of translation (substantially vertical), and means for adjusting the speed of translation of the elevator, in order to make it possible to adjust the quantity of powder of color sprayed per unit area of the object, as a function of the desired paint layer thickness, of the characteristics of the diffusion flux (and especially its flow, its powder rate ...), the type of color powder, the shape of the object, its linear surface ...

  the installation comprises means for removably mounting a coupled assembly (containment box / color box) on the paint elevator, in a position in which the axial direction of the containment box is substantially parallel to the vertical direction for translating the elevator, the installation comprises a conveyor of objects arranged in the upper part of the installation so as to pass over the paint station and provided with suspension members for the objects by a longitudinal end. longitudinal end of suspension of the object), which conveyor of objects is adapted to maintain immovable at least one object within the paint station, in a position, said painting position, in which the longitudinal axis of the The object passes through the axial lumens of a containment box mounted on the paint elevator (so that the object can pass through the box).

  In this preferred version, the invention also extends to a new method of painting generally cylindrical elongate objects, characterized in that: at least one object is disposed within the painting station in the painting position, coupled (containment box / color box (s)} being mounted on the paint elevator and each color box of the assembly being connected to at least the propellant and flow generating device suction, it triggers an operation, said diffusion operation, which induces the generation of at least one propellant flow and at least one suction flow, and moves the paint elevator along the object for a long time. longitudinal first end thereof towards its second longitudinal end, the object being held stationary in its painting position; in doing so, (s) diffusion flux is (are) projected onto the object by the spray orifice (s) of the containment box and the (s) suction flow produced (sen) t, inside the color box and containment box, currents able to carry the powder powder in excess powder in the box, when the paint elevator arrives at a position in which the second longitudinal end of the object extends into the containment chamber, at least the propellant flow generator is controlled so as to stop each propellant flow.

  In this preferred version of the invention, the large paint booth, able to receive an entire object, is therefore replaced by a small containment box removably mounted on an elevator, which is moved along the object as and when painting.

  With each change of color, it is therefore sufficient to replace the coupled assembly (containment box / color box) initially mounted on the paint elevator. In this case, the color change method according to the invention is characterized in that the coupled assembly (containment box / color box) initially mounted on the paint elevator is removed and then mounted on the paint elevator another newly coupled (containment box / color box) assembly (including another color box and a new or previously cleaned containment box).

  These operations take only a few seconds, and they are the only operations needed to change the color. Indeed, by replacing both the color box and the containment box, we replace all the elements of the installation that are exposed to the paint powder. The cleaning of the old containment box (which is the only part of the installation to be cleaned) is done in the margins of production, in masked time.

  It thus becomes possible to offer a wide range of colors at low cost, the color changes do not penalize the productivity of the chain.

  The containment boxes, and therefore the color boxes, may have small dimensions (the axial dimension of the box may be limited, its cross section depends on the section of the elongate object). As a result: - assembly / disassembly operations of a set (containment box / color box) on the paint elevator are easy; they can be done manually or be automated; when automated, these operations consume little energy (the coupled assembly has a moderate weight); the size of the installation according to the invention is considerably smaller than that of a prior known installation; operating costs are reduced; the installation may comprise a relatively large number of containment boxes, which makes it possible frequently to carry out color changes; in particular, it is possible to change twice (or more) of color, without waiting for the first containment box to be cleaned; - each containment box can be cleaned fully automatically in a cleaning booth; - The recycling rate of the powder powder in excess in a containment chamber according to the invention is much higher than that obtained in a large painting booth; indeed, the spraying zone is restricted to a small volume area around the object, so that almost all of the powdered powder reaches the object, and the suction recovery of the excess powder is carried out near the spray ports (as compared to the cabins which can receive an entire object, which comprise spray orifices arranged in the upper part of the cabin while the suction is preferably generated in the lower part thereof), so that that this recovery is maximum.

  Finally, the invention makes it possible to set up an individual and decentralized management of the production, which makes it possible to considerably reduce the lead times and the production costs, including for orders of small volume and requiring numerous changes of color.

  Furthermore, it is possible to provide a range of containment boxes comprising: - containment boxes adapted to different object models; the axial lumens of each box preferably correspond to an envelope of the cross section of the object model associated with the box, or even to said cross section (with a clearance close to), so as to obtain maximum confinement of the powder of color sprayed at inside the box; the range of containment boxes comprises, for example, boxes adapted to profiles of profiles, plate models ...; identical boxes, to allow a change of color within a batch of identical objects; containment boxes adapted to various types of finishing, and in particular boxes adapted to a single-color finish, boxes allowing a finish imitating the wood, as well as caissons adapted to a two-color finish (two different colors on either side of a longitudinal plane of the same object), said bi-color containment boxes, each comprising: two separation masks adapted to delimit, with an object passing through the containment box in the painting position, two independent confinement chambers each receiving a part of the object, two mating faces, for coupling the box to two color boxes, that is to say, more generally: - two sets of at least one recovery opening, the opening (s) of recovery of each series opening on one, specific to said series, of the two containment chambers, - two sets of at least one diffusion inlet opening, - two sets of at least one spray orifice, in which the spray orifice (s) of each series opens (nt) on one, specific to said series of orifice (s), of the two confinement chambers and is (are) connected (each) to a diffusion opening opening of one, specific to said series of orifice (s), two sets of opening (s) of diffusion input.

  Such a bi-color containment box makes it possible to obtain a two-color finish on the object in a single passage of the object within the paint station, and more precisely in a single translation of the paint elevator. along the object. To do this, each series of diffusion opening (s) of the box is connected to a source of colored powder specific to said series of apertures (s). Each confinement chamber (which includes a part of the object) therefore receives a color of its own. Note that the paint elevator of the installation is suitable for receiving a coupled assembly (bi-color containment box / two colored boxes). The steps of the color change method according to the invention defined for a coupled assembly (containment box / color box) are of course applicable to a coupled assembly comprising two or more color boxes. In addition, these steps also apply when it is a question of changing, not of color, but of type of containment box, for another finish or another model of object. The invention thus extends to a finishing change method and a method of changing the object model.

  Advantageously and according to the invention, in a painting process according to the invention using a containment box (whatever it may be): the paint elevator is, prior to the triggering of the diffusion operation, in an initial position low where a containment box mounted on the elevator extends below the object (this position allows either mounting a coupled assembly (containment box / box (s) color} on the elevator if an object is already in painting position and a color change is in progress, ie the introduction of the object within the paint station if the coupled assembly is already mounted on the elevator), - prior to the When the diffusion operation is triggered, the paint elevator equipped with a coupled assembly (containment box / color box (s)} is moved upwards along the object to a high position in the which the superior longitudinal end The suspension of the object extends inside the containment box, during the diffusion operation, the paint elevator is moved downwardly along the object from its upper longitudinal end to the object. 'at its lower longitudinal end.

  The painting of the object is thus done in a downward movement of the elevator. This version of the process according to the invention provides a better recovery rate of the powder powder in excess and a paint layer on the object more homogeneous. However, it remains consistent with the invention and qualitatively very satisfactory to paint the object in an upward movement of the elevator, that is to say to trigger the broadcast operation while the elevator is in a position lower paint in which the lower longitudinal end of the object extends inside the box, and complete this operation once the elevator in the raised position.

  Advantageously and according to the invention, the installation comprises a monobloc device, called fast connection device, for the connection of a color box to a network of fluids and energies, said fast connection device being connected, on the one hand at least the propellant flow generating device, the suction flow generating device and, where appropriate, the recycle flow generating device, and further comprising branch connectors at least at the (x) mouth (s) of the propellant flow, the suction port (s) and, if applicable, the drive shaft of the collection plate of the color box metering device, the device rapid connection incorporating the vibration device and the drive motor of the collection plate.

  If the installation includes a paint elevator (and containment boxes), the quick connect device is preferably carried by the paint elevator. Furthermore, the installation advantageously comprises at least two quick connection devices, at least one of which can be removably mounted on the paint elevator for a bi-coloring operation.

  Advantageously and according to the invention, the installation comprises: - a storage area for objects, - at least one preprocessing cabin, the object conveyor being adapted to transport the objects through said pre-treatment cabin from an opening of end thereof communicating with an outlet of the storage area to an opposite end opening communicating with the paint station; the object conveyor is preferably also adapted to transport the objects through the pretreatment cabin in the other direction, - at least one post-processing booth, the object conveyor being adapted to transport the objects through said post-treatment booth from an end opening communicating with the paint station; the object conveyor is preferably also adapted to transport the objects through the post-processing cabin in the other direction, - if necessary, a zone, called box area, storage and maintenance of confection boxes, comprising at least one cleaning cabin of at least one containment box, means for automatically coupling / uncoupling a confection box and at least one color box, and conveying means for a coupled assembly (containment box / color box (s)} between the box area and the paint station, - where applicable, automatic mounting / dismounting means for a coupled assembly (containment box / box (es)) color} on the paint elevator, - means of automatic handling of the color boxes within the store and means of conveying color boxes between the store and the paint station or, where appropriate, between the store and the zone d cans, - a maintenance station for color boxes.

  The invention also relates to a painting installation, a painting method and a color change method characterized in combination by all or some of the characteristics mentioned above and below.

  Other objects, features and advantages of the invention will become apparent on reading the following description which refers to the appended figures representing preferred embodiments of the invention given solely by way of nonlimiting examples: FIG. 1 is a perspective view of an installation according to the invention adapted to the painting of elongated objects and provided with containment boxes, - Figure 2 is an axial sectional view along the plane AA of a coupled assembly {box 3 is a cross-sectional view along the plane BB of the containment box of FIG. 2; FIG. 4 is a view in cross-section along the plane CC of FIG. the color box of FIG. 2; FIG. 5 is a cross-sectional view along the plane BB of the color box of FIG. 2; FIG. 6 is a perspective view of a containment box of FIG. bi-coloring according to l FIG. 7 is a cross sectional view of part of the bi-color containment box of FIG. 6; FIG. 8 is a partial perspective view of another embodiment of a FIG. color box according to the invention, - Figure 9 is a transverse vertical sectional view of a detail of the color box of Figure 8.

  The installation according to the invention illustrated in FIG. 1 comprises: a storage area 100 comprising two object magazines, each store comprising a plurality of rows of stored objects suspended by one of their longitudinal ends; two cabins 101, 102 for pretreatment of objects prior to painting, arranged in parallel, one next to the other; the cabins have a height sufficient to be able to receive a suspended object in its entirety and a length making it possible to treat concomitantly a plurality of objects following each other in Indian file; each cabin is equipped according to the treatment to be carried out: degreasing and / or pickling of the objects by spraying a degreasing and / or stripping solution, rinsing with water of the preceding solutions, drying of the products ...; depending on the treatments concerned, it is possible to equip an upstream portion of a cabin for a first treatment and a downstream portion thereof for a second treatment, different from the first; a paint station 1, communicating with the end openings 105, 106 of the pretreatment cabins 101, 102, and which comprises a paint elevator 14 and a lower gripping member 18 (for gripping the lower end of FIG. the object, with a view to a total immobilization thereof in the painting position), both slidably mounted in a substantially vertical direction, a cabin 107 for post-processing objects after their painting, including an opening of end 108 communicates with the paint station 1; the post-treatment cabin is arranged parallel to the pretreatment cabins 101, 102; it is equipped for one or more of the following treatments: drying, firing paint by radiation or convection ...; - A color box store 22, backed by the post-processing cabin and in which can be stored a large range of color boxes 21; an area of the caissons 109, in which the various containment caissons 4, 5, 6 of the installation are stored and the sets (containment box / color box (s)) are prepared; the box area further comprises a cabin 110 for cleaning, by suction, a containment box; an object conveyor 2 equipped with suspension members for the objects; the conveyor 2 is formed of several rails extending in the upper part of the installation so as to pass over the two storage magazines 100, the two pretreatment cabins 101, 102, the paint station 1, the cabin aftertreatment 107; the storage area 100 and the paint station 1 are fully open in the upper part and the preprocessing and post-treatment booths have upper slots for the passage of the objects transported in the suspended position by the conveyor of objects; means 114 for automatically handling the color boxes within the color box magazine 22, and a color box conveyor 113 suitable for transporting color boxes between the magazine 22 and the box area 109; 115 of maintenance of the color boxes, - a conveyor (not shown) of coupled assemblies (containment box / color box (s)} between the zone of the caissons 109 and the paint station 1, and means (not shown ) automatic assembly / disassembly of a coupled assembly on the paint elevator 14.

  Given the parallel arrangement of the various stations of the installation, an object leaving the storage area 100 can be transported by the conveyor 2 to one or other of the pretreatment cabins 101, 102 or to the aftertreatment booth 107, the respective end openings 103, 104, 112 of which are side by side; it can also be directly transported to an area 111 (not shown) for loading / unloading objects in which the objects are manually attached to the suspension members of the conveyor (for storage in zone 100 or directly of their treatment) or from the latter (following their treatment or without having been treated in case of cancellation or error of preparation of an order). At the exit of the storage area 100, the object is for example conveyed through the pretreatment cabin 101 where it undergoes appropriate prior treatment. At the exit of this cabin, according to the treatment provided, the conveyor positions the object in the paint station for painting or conveys it through the pretreatment cabin 102 (or again the cabin 101 or possibly the cabin post-treatment 107). In the second case, at the exit of the cabin concerned, the conveyor transports the object again to the paint station, via the cabin 101 for example. After painting, the object is conveyed by the conveyor through the post-processing cabin 107 from the end opening 108 thereof to its opposite end opening 112, for baking and / or drying of the paint layer. At the exit of the cabin 107, the object is transported to the zone 111 of loading / unloading, or is again presented at the entrance of one of the cabins 101, 102, 107 for a new treatment (second layer of paint for example, for the realization of complex paintings: varnishing, imitation wood ...). The relative arrangement of the various stations of the installation makes it possible to treat each object individually, according to the treatment desired for the object.

  The paint installation according to the invention illustrated in FIG. 1 comprises, as a painting booth, a confinement box such as the containment box 3 illustrated in FIGS. 2 and 3. The latter comprises an externally parallelepipedal casing 7, formed by an outer wall 9 and an inner wall 8 also parallelepiped in which are provided axial slots 10, 11. The axial lumen 10 passes through the two walls in the central part of an upper face of the containment box, the axial lumen 11 passing through the two walls in the central part of an opposite lower face of said box. The axial lumens 10, 11 are facing each other in an axial direction 3 of the containment box. They allow the passage of an object through the containment box and the sliding of the box along the object.

  The inner wall 8 of the box also has a plurality of orifices 12 forming spray nozzles, called spray orifices. These orifices 12 are distributed around the axis 3 of the box on the same cross section (section orthogonal to the axis 3) of said box. Each spray orifice is connected to a diffusion inlet opening 19 formed in the outer wall 9 of the box, by a flexible duct 20 with tribostatic PTFE effect, said spray pipe. At each spray orifice 12 corresponds a spray pipe 20 and a diffusion inlet opening 19 specific to said orifice. The casing also has a recovery opening 13 passing through its inner and outer walls, formed in a lower part of the box, below the spray orifices 12. The diffusion inlet openings 19 and recovery 13 are all arranged on the same side face 55 of the housing, said coupling face.

  Note that the spray ports 12 have a reduced section relative to that of the spray ducts 20 in order to accelerate (venturi effect) the diffusion flows out of these ducts, for a more targeted and more effective powder projection . The installation according to the invention also comprises at least as many

  21 color boxes of colors proposed by the manufacturer. These color boxes are adapted to be coupled to the paint booth, that is to say to a containment box, as shown in Figure 2.

  Each color box 21 comprises a parallelepipedal outer casing 23 successively enclosing a reservoir 25 containing color powder 24, a distribution plate 32 and a filter chamber 26. The reservoir, the distribution plate and the filter chamber are also cuboid.

  The reservoir 25 is provided with a volumetric dosing device 41 (see FIG. 5) comprising three disks 43 for collecting and volumetric dosing of the powder and a scraping plate 44. Each collection disc 43 rests on the bottom 37 of the reservoir and is rotatably mounted around its center. The collection discs 43 are substantially aligned with the rectangular bottom 37 in a longitudinal direction of said bottom. The rotational drive of each disk is provided by a drive rod which is fixed to the center of the disk and which successively passes through the bottom 37 of the tank and the distribution plate 32, to open in the upper part of the filter chamber 26 The lower end of each rod carries a gear cooperating with a worm 45a. A single motor shaft 45b makes it possible to simultaneously drive the three collection discs in rotation, by means of the worm. The driving end of the shaft 45b is located on an outer face 49 of the so-called control surface housing.

  Each collection disc 43 has a central disc area 51 full and a perforated circular peripheral area 52 pierced with through holes. These holes are closed below by the bottom 37 of the tank on which the discs are placed; they form as many compartments 50 receiving and volumetric dosing of the color powder. The bottom of the reservoir also has six holes 36 for the evacuation of the powder collected by the collection discs 43 and the powder supply of six diffusion ducts 33, formed in the distribution plate 32. Each evacuation bore 36 is located opposite the perforated zone 52 of a collection disc 43, so that the powder present in a collection compartment of the disc is evacuated in the diffusion duct 33 communicating with said piercing when this compartment passes through. above the hole (during the rotation of the disk).

  The scraper plate 44 of the metering device rests on the collection discs 43. It is articulated on each of these discs by means of an anchor 46 housed on the one hand in an eccentric mortise of the disc of collection arranged at a distance r of the center of the disc which distance is the same for each disc, and secondly in a mortise of the scraping plate formed on a median longitudinal axis of said plate. The three drive pins of the scraping plate thus each describe a circle of radius r around the center of the corresponding disc, when the discs are rotated. Each peg forms with the center of the associated disc and the radius connecting the peg to said center, a driving rod of the scraping plate. The scraper plate is thus moved in its frontal plane, parallel to the bottom 37, in a quasi-rectangular movement allowing it to cover more than 95% of the rectangular section of the reservoir.

  The scraper plate 44 has two main functions. It participates first, together with the open areas 52 of the collection discs, the volumetric dosage of the powder. Indeed, the scraping plate 44 has solid portions 53 forming doctor blade cooperating with the upper face (opposite to the bottom of the tank) of each collection disc 43. The arrangement of these solid portions 53 and the relative movements of the scraper plate and collection discs (movement on rods of the scraper plate and rotation of the collecting discs) are such that each collection compartment 50 is alternately, on the upper face, open for filling by gravity with powder and then covered by a solid portion of the scraper plate and that, for each discharge bore 36, a solid portion of the scraper plate covers at all times the collection compartment located opposite said discharge port (in other in other words, each discharge bore 36 is constantly masked, above the corresponding collection disc 43, by a solid portion 53 of the scraper plate). Thus, the scraping plate allows successively: the filling of each compartment 50 and thus the collection of the powder (over a circular zone), when the scraping plate 44 does not cover the compartment, the isolation of a calibrated volumetric powder dose, when the scraper plate scrapes the upper face of the collection disc and closes the top of the compartment; the closed compartment indeed contains a volume (a dose) of powder corresponding exactly to the subject of a sufficient powder level in the reservoir to the volume of the compartment defined by the thickness of the collection disk and the cross-section of the through hole forming the compartment the evacuation of the dose of insulated powder when the compartment 50 passes opposite an evacuation bore 36 while the scraping plate 44 still closes the top of the compartment.

  Note, considering the kinematics of the scraper plate, that its solid portions 53 are annular.

  Furthermore, the scraper plate 44 provides a raking function of the powder in a plane parallel to the bottom of the tank. For this purpose, the scraper plate preferably has recessed portions 54. Due to its shape and its kinematics, the scraper plate sweeps almost the entire surface of the bottom; in doing so, it rakes the powder and prevents the formation of inverted cones of powder flow. Note that the formation of such cones is already greatly reduced by the circular shape (and not punctual) of powder collection areas. The powder level is constantly substantially flat, which not only makes it possible to obtain a substantially constant evacuated powder flow rate (at a constant rotational speed of the disks 43), but also to use the color box until almost complete exhaustion. of the tank. In addition, the scraping plate avoids the appearance of a granulometric or mass gradient in the powder on the height of the tank. Indeed, being flat and only moved in its frontal plane, the scraping plate rakes and distributes the powder in layers. It causes no vertical mixing of the powder, which would have the detrimental consequence of generating such a granulometric gradient and / or mass, the lightest powder particles (usually the finest) tend to rise during brewing while the heavier ones (usually larger ones) are driven to the bottom of the tank. This characteristic further distinguishes the metering device according to the invention from the prior devices, which, besides the fact that they are unsuitable for elongated rectangular section and bottom tanks, are all provided with rotating arm stirrers superimposed in a quincunx leading to a vertical mixture of the powder. The scraping / sweeping plate 44 contributes to providing, at the outlet of the drain bores 36, a powder of quality (particle size distribution, properties, etc.) that is constant over time.

  As previously mentioned, the distribution plate 32 comprises six slot slots 33, closed on the top by the bottom 37 of the powder tank or by an additional closure plate, and closed on the bottom by the upper wall 38 of the filter chamber. or by an additional closing plate. Each slot 33 forms a diffusion duct into which a discharge bore 36 opens (this bore also passing through the possible closure plate present above the distribution plate). Each diffusion conduit opens on the one hand on an edge of the distribution plate 32 located on the control surface 49 of the color box, and on the other hand on an opposite edge of said plate located on one side 48 opposite of the box, said mating face, which, in the example, is flat (the box being parallelepiped). Corresponding lumens are provided in the outer casing 23 of the color box on the control and coupling faces, facing the diffusion ducts. The end 34 of each diffusion duct 33 located on the control face 49 forms a propeller flow inlet mouth, while the end 35 of the duct located on the coupling face 48 forms a diffusion outlet mouth of the color box. A propellant gas stream, generated by a propellant flow generating device, can thus be introduced into the color box through each propellant flow inlet mouth 34. This propellant flow is charged in color powder 24 from the reservoir at the evacuation bore 36 opening in the diffusion conduit, to form a diffusion flux. The metering device 41 and the evacuation holes 36 form powder supply means for each propellant flow. The diffusion flux leaves the color box through the diffusion outlet mouth 35 of said conduit 33, to penetrate, via a diffusion inlet opening 19, into a spraying conduit 20 of the containment box 3. coupled to the color box. The diffusion outlet mouths 35 of each color box and the diffusion inlet openings 19 of each containment box of the installation are provided respectively in the outer casing and the distribution plate of the color box and in the outer wall of the housing of the containment box, so as to be facing each other when the box and the box are coupled.

  The powder rate of the diffusion flux is adjusted, as a function of the flow rate of the propellant flow supplied and the desired surface quantity of powder to be projected on the object, by modulating the speed of rotation of the collection discs 43; that is, by modulating the rotational speed of the motor shaft 45b.

  The filter chamber 26 of the color box comprises a filter 27 for retaining the color powder and a sieve 28 fixed on a bottom 29 of the chamber, said bottom recovery. The bottom 29 has two slopes facing the powder leading to a conduit 30 recycling. The conduit 30 is pierced with holes along these slopes or is fully open at the top (as shown), to allow the evacuation of the powder. This recycling duct 30 exits the outer casing of the color box on two lateral faces thereof, goes up to the upper part of the box and passes through the outer casing again to open in the upper part of the reservoir 25. The recycling duct 30 thus has two portions, said outer portions, extending outside the outer casing 23, on either side thereof.

  The filter chamber 26 also comprises at least one suction mouth 39 formed in the control face 49 of the outer casing, and at least one recovery mouth 40 formed in the coupling face 48 of the casing. At each suction mouth may be applied a suction stream 203 (generated by a suction flow generating device) producing a suction stream 202 within the filter chamber. This suction flow circulates through the filter chamber from each recovery mouth 40 to a suction mouth 39, thus passing through the filter 27. Each recovery mouth 40 opens, when the color box 21 is coupled to the containment box 3, on a recovery opening 13 of said box. These mouth and opening are provided in the coupling faces 48, 55 of the box and the box so as to be facing one another. Thus, a stream 200 of powder recovery is produced inside the containment box 3 via the suction stream 202.

  The recovery stream 200 makes it possible to recover the powder of powdered color in excess. The stream 201 successively passing through the opening (s) and mouth (s) of recovery of the box and the color box is said recovery stream.

  In the illustrated example, the color boxes 21 of the installation each comprise a single recovery mouth 40, which extends over the vast majority of their length and cooperates with a single opening 13 for recovering the coupling faces of the containment boxes. Alternatively, said boxes and boxes may have a plurality of openings and recovery openings. Moreover, each color box illustrated (see Figure 6) has three suction mouths 39 distributed over the length of the color box. Of course, the invention is not limited to this configuration, given solely by way of example.

  Each diffusion inlet opening 19 of the containment box is equipped with a seal 47 housed in a groove surrounding the opening, in order to allow a gas-tight coupling of this opening and a combined diffusion outlet mouth. a color box. Similarly, each recovery opening 13 of the containment box is equipped with a seal housed in a groove surrounding the opening, to allow a gas-tight coupling of this opening and a combined recovery mouth of a color box. It would be possible, as a variant, to equip such seals with outlet outlets for diffusing and recovering color boxes. This solution would however be less economical.

  The recovery mouth 40 of each color box 21 or each of the recovery mouths, if the color box has several is also equipped with a non-return valve 58, able to open towards the inside of the filter chamber under the effect of the suction stream 202 when a suction flow is applied to the suction mouths 39 of the color box. Conversely, this valve closes under the effect of a contrary current, called unclogging current, which passes through the filter chamber from the suction mouths 39 to the recovery mouth 40. This declogging current is generated by applying to the suction mouths 39 a so-called declogging flow, in order to expel the powder particles retained by the filter 27 towards the sieve 28. The suction flow generation device of the installation is advantageously adapted to also generate the opposite flow of unclogging. This operation is periodically controlled to prevent clogging of the filter and to limit the phenomena of clogging of the powder particles between them occurring in the filter.

  The sieve 28 of the filter chamber of the color box is arranged below the filter 27 so as to recover the powder particles stopped by this filter. This screen is integral with the recovery floor 29 of the chamber and the recycling duct 30. It is animated by small vibratory movements through the conduit 30: a vibration device comes, periodically or continuously, apply an alternating force on one of the outer portions of the recycling duct so as to impose thereon small horizontal displacements embodied by the arrow 56. For example, the vibration device comprises a motor shaft and a cam 59 resting on the conduit 30 (see Figure 4). This device is completely independent of the color box.

  The recycling duct 30 has moreover at least one orifice (not shown) in each of its outer portions, formed in the lower part of the duct. These orifices are for example formed in each of the two elbows defining the lower horizontal section of the duct (which extends mainly in the filter chamber) and the two vertical sections thereof (which go back to the tank). In operation, these orifices are connected to a device for generating a gaseous flow, referred to as a recycle stream, capable of conveying color powder, which flow ensures the transport to the reservoir of the powder recovered under the sieve.

  Each color box finally comprises an access port to the powder reservoir, closed by a removable cap 31, to allow filling of the reservoir when the amount of powder it contains comes to exhaustion.

  The coupled assembly (containment box / color box) illustrated in FIG. 2 is mounted on the paint elevator 14 by means of a mounting plate 17, which on the one hand carries the coupled assembly and on the other hand is carried by the elevator 14. The coupled assembly is fixed by any appropriate means on the mounting plate 17; this operation is carried out manually or automatically in the zone of the boxes 109. The mounting plate provided with the coupled assembly is then fixed on the paint elevator 14 by any appropriate means and the color box is connected to a device 57 quick connection carried by the paint elevator 14; these two operations are performed manually or automatically, when a color change (which requires the use of another color box and a clean containment box) or a change of finish or object (which requires the use of another containment box). The quick connect device 57 enables the color box to be connected to the propellant flow generating device, the suction flow generating device, the vibrating device, the recycle flow generating device and any other necessary devices. for the control, execution and control of painting operations, such as a computer control unit, a powder level detection device cooperating with a detection member 42 of the color box reservoir, a cable of control and control of the rotational speed of the shaft 45b of the metering device, etc.

  The paint elevator may be equipped with a second rapid connection device (not shown) in the case of a bi-coloring operation. In this case each of the two color boxes coupled to the bi-color confinement box is connected to one of the quick-connect devices, which is its own.

  The mounting plate 17, the fastening means of the coupled assembly (containment box / color box (s)} on the plate 17 and the fixing means of the mounting plate 17 on the paint elevator 14 define means for mounting a coupled assembly on the paint elevator.

  The painting process according to the invention in such an installation proceeds as follows: - The paint elevator 14 being in the low position, an object is brought into the painting position in the paint station 1 by the conveyor of 2. In this position, the axis 5 of a containment box 3 mounted on the paint elevator 14 coincides with a central longitudinal axis of the object, so that the object can pass axially through the box.

  - The paint elevator, provided with a coupled assembly (containment box / color box (s)} each color box is connected to a device 57 fast connection, is moved to a high position in which the upper end of the suspension of the object is inside the containment box 3, facing or below the spray orifices 12 of the latter. The paint elevator is preferably moved by means of hydraulic or pneumatic cylinders (not shown) controlled by computer. All other means of automatic movement (for example motor with cable and geared motor) and control (automatons ...) can be used.

  - The lower gripping member 18 is positioned near the lower longitudinal end of the object, which lower end is attached to the gripping member.

  - The set of devices necessary for the painting of the object is triggered, as part of an operation called broadcast operation; in particular, the propellant flow generating and suction flow generating devices are controlled to deliver propellant flows to the propellant inlet ports and suction flows to the suction ports of each color box. The paint elevator is moved downward as diffusion streams (powdered) are sprayed by the spray orifices of the containment box 3; the speed of movement of the elevator is chosen and controlled, particularly as a function of the desired paint layer thickness.

  - When the paint elevator 14 has arrived at a position in which the lower end of the object is located inside the containment box, facing or above the spray orifices of the latter, the device propellant flow generation is controlled to stop any generation of propellant flow. Concomitantly or a few fractions of a second later, the device for generating suction flow and possibly all other painting devices are also stopped.

  - The lower end of the object is released; the gripping member 18 and the paint elevator 14 are moved downwards to respective lower positions allowing the painted object to be released and transported to the post-processing cabin 107 by the object conveyor 2.

  All the painting operations described above (including bringing and positioning the object in the paint station and removing the object after painting) lasts 50 to 70 seconds if it is desired to make a layer of 8011m thick paint on a joinery profile measuring 6.5m long and having a total surface to be painted of 1.40m2. The instantaneous paint speed (diffusion operation only, which lasts 30 to 40 seconds) is of the order of 220 m 2 / h. Moreover, counting the periods of immobilization (a few seconds) of the installation at each color change, the efficiency of the installation according to the invention can be evaluated to 60 profiles (of 1, 4 m 2) per hour in mono. staining, 50 sections (of 1.4m2) per hour in two colors, 20 sheets per hour. The number of color changes made per hour naturally affects yields, but this influence remains low (unlike earlier installations where color changes are catastrophic for productivity). The yields previously given as examples can be increased by hanging two objects on a multiple suspension member of the conveyor and using a confinement box, said duo containment box, able to be traversed by two objects and having two faces. Coupling for the reception of two color boxes containing the same color powder (unlike the bi-coloring box, the duo box is devoid of separation masks).

  The installation according to the invention makes it possible to paint objects made in all types of materials, since the color powder used is adapted to the material concerned and the material can be prepared and the consolidated paint respectively in the pre-treatment cabins 101 The color powders used are, for example, thermosetting powders, particularly suitable for aluminum objects, photocurable powders, and the like.

  In order to effect a color change in such a painting installation, the coupled assembly (containment box / color box (s)} present on the elevator is first removed. To do this, the paint elevator is brought to the down position if it was not its previous position and if an object is present in the painting position in the paint station. The mounting plate 17 that it carries, provided with the assembly (containment box / box (s) of color} to be replaced, is detached from the elevator 14. It then goes up on the elevator another set {caisson containment / box (s) of color}, previously coupled in the box area. To do this, attach a mounting plate carrying the new coupled assembly (containment box / color box (s)} on the elevator. The mounting plate of this new assembly is preferably another mounting plate 15, 16 or 72, on which the new coupled assembly has been fixed in masked time in the area of the boxes, for example during the last painting operation. The former set (containment box / box (s) of color} is then detached from its mounting plate, in masked time (while the new painting operation has begun), for the purpose of cleaning the containment box. Alternatively, the old mounting plate 17 can be reused to carry the new set (containment box / color box (s)). The immobilization of the installation is slightly longer in this case since it is necessary to separate the former assembly (containment box / color box (s)} from said mounting plate to be able to fix the new assembly. This immobilization remains very short.

  Color change operations take less than 60 seconds if done manually and less than 30 seconds if done automatically.

  Figures 6 and 7 illustrate a bicolour containment box 6. This comprises two parts 61, 62, separated at a median axial plane of the box. Between these two parts are arranged two separation masks 67, 68 extending in the median plane of separation of said parts. The thickness of the masks is chosen so as to fill (with one game close) the space between the two parts 61, 62 of the housing. The masks are positioned, with the aid of positioning devices 69, 70, so as to allow the passage of an object through the axial lumens 71 of the containment box and abut against this object. Thus, the inner wall 76 of the casing, the masks 67, 68 and the object itself delimit two independent confinement chambers 81, 82. Note that the carpentry object shown in Figure 7 comprises two sections 73, 74 of aluminum assembled by a central rod 75 synthetic thermal break. Each section 73, respectively 74, passes through one of the confinement chambers 81 and 82 respectively when the object is in the painting position.

  The inner wall 76 of the housing comprises a first series of five spray orifices 77, 78 opening on the confinement chamber 81 (specific to this first series of orifices), and a second series of five spray orifices 79, 80 opening on the confinement chamber 82 (suitable for this second series of orifices). The spray ports 77, 78 of the first series are connected to the diffusion inlet openings of a first coupling face of the box, via spray pipes extending into the first portion 61 of the housing; a color box 63 is coupled to the containment box by this first coupling face. The spray ports 79, 80 of the second series are connected to the diffusion inlet openings of a second mating face of the box opposite to the first, via spray ducts extending into the second part. 62 of the housing; a color box 64 is coupled to the containment box by this second coupling face. Each of the two coupling faces of the box further has a recovery opening such as that illustrated for the box 3 in Figures 1 and 2.

  It should be noted that the spray ducts connecting the spray orifices 78 and 80 to diffusion inlet openings extend partly inside the confinement chambers 81, 82, parallel to the median plane of separation of the casing, such that the diffusion flows leaving the orifices 77, 80 are parallel to the masks 67, 68. These diffusion flows reach the faces and the least recesses of the sections 73, 74 of the object which would not be visible from the orifices of spraying 77, 79.

  The painting of an object in two distinct colors is carried out by means of such a bi-color containment box, in a single painting operation, that is to say in a single diffusion operation corresponding to a single translation of the paint elevator. This method is particularly advantageous for joineries formed of two assembled sections, such as that illustrated, the profiles 73, 74 being painted while they are already assembled. However, this method can be applied to any type of object (monoblock or formed of several assembled portions, monomaterial or multimaterial ...) to paint a longitudinal portion of the object in a first color and the other longitudinal portion of the object in a second color.

  Note that the illustrated bi-color containment box has a cylindrical inner wall 76 of circular section. This wall could be parallelepipedal like the caisson 3 illustrated in FIGS. 1 and 2. On the other hand, a simple staining confinement caisson such as the caisson 3 can have a cylindrical inner wall of circular section, which has the advantage of reduce the volume of containment to a strict minimum and therefore limit the amount of powder spray that does not reach the object and must therefore be recovered. The rate of powder loss is minimal when the containment box has a cylindrical inner wall of circular section.

  Figures 8 and 9 illustrate another embodiment of a color box according to the invention. The elements common to the color boxes 21 (Figures 2, 4 and 5) and 90 (Figures 8 and 9) have the same reference numbers. The color box 90 comprises a metering device comprising a rectangular collection plate 91 and a scraper bar 94. The collecting plate 91 rests on the bottom 37 of the tank and is mounted mobile parallel to this bottom by means of two connecting rods 92. Said rods are hinged on the one hand on the bottom 37 at two points located on the axis. longitudinal median of the reservoir, and secondly on the collection plate 91 at two points located on the median longitudinal axis of said plate. The rods are housed in two lower recesses 98 (disc-shaped) of the collection plate.

  The scraper bar 94 is fixedly mounted in the reservoir. It rests on the upper face of the collection plate 91, facing the median longitudinal axis of the bottom 37. The scraper bar 94 is traversed by six evacuation holes 95, leading to six tribostatic tubes 96 forming ducts d 'evacuation. Each evacuation duct extends into the reservoir between the scraper bar 94 at the evacuation bore and the bottom 37 of the reservoir, through which it passes through a supply bore 97 (in dashed lines in FIG. 10). in a bottom area 37 which is not covered by the collection plate 91 during its movements. The exhaust duct 96 opens into a diffusion duct of the distribution plate 99 (note that the distribution plate 99 is similar to that 32 of the color box 21, except for the location of its diffusion channels).

  Each evacuation conduit 96 substantially forms a loop inside the reservoir. These ducts 96 are made of a tribostatic effect material such as PTFE. Such a color box is used to dispense tribostatic activation powder (if the spraying ducts of the containment boxes of the installation do not allow this activation themselves, because they are not designed in a suitable material or have insufficient length).

  The collection plate 91 has perforated collection areas 93, with through holes forming, together with the bottom 37 of the tank, as many compartments for collecting and volumetric dosing of the powder. Taking into account the kinematics of the collection plate 91 and the position of the evacuation holes 95 (collection plate mounted on two connecting rods articulated on the median longitudinal axis of the bottom, fixed evacuation orifices facing the axis longitudinal median of the bottom), the open areas 93 of the collection plate are circular and aligned in the longitudinal direction of said plate; the centers of these circular areas are located on the median longitudinal axis of the collection plate.

  Due to its shape and its kinematics, the collection plate 91 describes more than 90% of the bottom surface 37 during its movements. In addition to its function of collecting the powder, the plate performs the sweeping and streaking function described above for the scraper plate 44 of the color box 21. The scraper bar 94 participates in the metering of the powder by scraping the powder. upper face of the collection plate and closing each collection compartment when it arrives close and next to a drain hole 95.

  The invention may be subject to numerous variations with respect to the embodiments described and illustrated.

  In particular, the invention is not limited to an installation 30 comprising containment boxes. Indeed, the interest of using color boxes according to the invention remains intact in the case of an installation comprising a conventional paint booth, which remains fixed during painting operations and is mounted in the installation of not removable.

  Indeed, the use of color boxes limits the cleaning operations to the only cleaning of the paint booth, which can be performed in less than 5 minutes and automatically, especially if the internal walls of the cabin are covered with a consumable plastic sheet which it is sufficient to replace, as recommended by EP 291 423. In addition, the color boxes can be of reduced size, including in an installation equipped with a paint booth. It suffices to provide all the entry openings for diffusion of the paint booth in a lower portion thereof, close to its (their) opening (s) recovery, and connect the spray orifices of the cabin located in an upper portion thereof at these diffusion inlet openings by spray pipes.

  On the other hand, the numbers of diffusion inlet mouths and suction mouths of the color boxes are not limited to those provided in connection with the illustrated embodiments.

  In addition, the installation may comprise at least one tri-color containment box, provided on the one hand with three separation masks defining three confinement chambers around the object in the painting position, and on the other hand with three mating faces for mating with three separate color boxes. Similarly, it is possible to envisage a quadraphinium containment box, receiving on each of its lateral faces a color box, while the four separation masks of the box are arranged on its diagonal planes.

Claims (31)

  1 / Industrial installation of paint for painting objects by means of at least one gaseous flow loaded with color powder, said diffusion flux, projected onto each object, said installation comprising a paint station 5 (1) comprising a paint booth (3) comprising a housing (7) for confining the projected diffusion stream (s), at least one orifice (12), called a spray orifice, directed towards the inside of the booth paint, for the projection of (the) diffusion flux, ^ at least one opening (19), said opening of diffusion entry, opening on the outside of the painting booth for the entry of a diffusion stream, each spray orifice being connected to a diffusion inlet opening, at least one opening (13), said recovery opening, opening on the outside of the paint booth and communicating with the inside said cabin, and through which a gaseous stream, called a recovery stream n, can be produced inside the cabin for the recovery of the powder powder in excess, characterized in that: - the installation comprises a store (22) boxes (21), said color boxes, each containing a color powder (24), each color box having an outer casing (23), inside said outer casing, a reservoir (25) of colored powder, at least one mouth (34), so-called propellant flow inlet mouth, opening on the outside of the outer casing and adapted to be connected to a device for generating a gas flow, said propellant flow, capable of conveying color powder, less a mouth (35), said diffusion outlet mouth, opening on the outside of the outer casing, means (33, 41, 36) of supply, between each inlet of the propellant flow (34 ) and a diffusion outlet mouth (35) of the powdered propellant gas stream from the reservoir , to form a diffusion flux, ^ inside the outer casing, a chamber (26), said filtering chamber, provided with at least one filter (27) able to retain at least a portion of the color powder at least one mouth (39), said suction mouth opening on the outside of the outer casing and communicating with the inside of the filter chamber, said suction mouth being adapted to be connected to a device for generating a suction gas flow, at least one mouth (40), called the recovery mouth, opening on the outside of the outer casing and communicating with the interior of the filter chamber, the filter being arranged such that the suction flow (s) produced inside the filter chamber a gaseous stream, said suction stream, passing through the filter from each recovery mouth to a mouth suction, - each color box (21) is adapted to be able to e coupled, directly and removably, to the paint booth (3), each diffusion outlet mouth (35) of said color box being arranged in correspondence with a diffusion opening opening (19) of the booth of paint so as to be contiguous thereto when the color box and the painting booth are coupled, each recovery mouth (40) of said color box being arranged in correspondence with a recovery opening (13) of said paint booth so that it can be contiguous to the latter when the color box and the paint booth are coupled.   2 / Apparatus according to claim 1, characterized in that each color box comprises at least one conduit (30), said recycling duct, connecting the filter chamber (26) and the powder reservoir (25) for the recycling of the powder recovered and filtered in the filter chamber.   3 / Apparatus according to claim 2, characterized in that the recycle conduit has an orifice, said recycle flow orifice, 5 communicating with the outside of the outer housing and adapted to be connected to a device for generating a gas stream, said recycle stream, capable of conveying color powder for transport in the recycling line, to the reservoir, the recovered powder and filtered in the filter chamber.   4 / Apparatus according to one of claims 1 to 3, characterized in that each diffusion outlet mouth (35) of each color box and / or each diffusion inlet opening (19) of the paint booth, as each recovery mouth (40) of said box and / or each recovery opening (13) of the cabin, are provided with sealing members (47) able to ensure a gas-tight coupling of the box color and paint booth.   5 / installation according to one of claims 1 to 4, characterized in that each color box comprises an access port to the powder tank, closed by a removable cap (31).   6 / Apparatus according to claim 1 to 5, characterized in that: the paint booth comprises at least one face (55), said flat coupling face, in which are provided at least one diffusion inlet opening and at least one recovery aperture, the outer casing of each color box comprises a face (48), said coupling face, flat, conjugate to each coupling face of the paint booth, and in which are provided each diffusion outlet mouth and each collection mouth of the color box so as to correspond to the opening (s) of diffusion and opening (s) of recovery of a coupling face of the paint booth.   A plant according to one of claims 1 to 6, characterized in that each color box comprises, for each diffusion outlet mouth, a conduit (33), said diffusion conduit, connecting said outlet mouth of diffusion (35) to a propellant flow inlet (34).   8 / Apparatus according to claim 7, characterized in that each diffusion duct (33) is arranged outside the reservoir and in that the reservoir has, for each diffusion conduit, a bore (36), said piercing d supply, opening on the diffusion conduit for the powder supply of the propellant gas flow.   9 / Apparatus according to claims 6 and 7, characterized in that the color box (90) comprises, for each diffusion conduit, a tube (96), said tribostatic tube, a tribostatic material, arranged in the reservoir of powder so as to collect color powder and electrically charge the collected powder, which tribostatic tube passes through the supply bore (97) to open into the diffusion conduit.   10 / Apparatus according to one of claims 1 to 9, characterized in that the paint booth (3) comprises, for each spray orifice (12), a conduit (20), said spray pipe, connecting said orifice spraying at a diffusion inlet opening (19).   11 / Apparatus according to claim 10, characterized in that each spray duct (20) of the paint booth is a tribostatic material.   12 / installation according to one of claims 1 to 11, characterized in that each spray orifice (12) of the spray booth is provided with an electrode connected to a voltage source so as to generate an electric field between said electrode and an object disposed inside the paint booth and connected to a mass.   13 / Apparatus according to one of claims 1 to 12, characterized in that each color box comprises a device (41) for dosing 30 the flow of color powder feeding each propellant flow.   14 / Apparatus according to one of claims 1 to 13, characterized in that the outer casing (23) and the reservoir (25) of each color box are parallelepipedic.   15 / Installation according to one of claims 1 to 14 and according to claim 7, characterized in that, for each color box: the reservoir (25) has at least one plane face (37), - the filter chamber (26) has at least one planar face (38) facing the flat face of the reservoir, - the color box comprises a distribution plate (32) arranged between the reservoir and the filter chamber, between their two planar faces. view, in which are formed the diffusion conduit (s) (33), the propellant flow inlet (s) (34) and the diffusion outlet mouth (s) (35).   16 / Apparatus according to claim 15, characterized in that the distribution plate is formed of at least one plate (32) having at least one slot (33) extending from one edge to another of the plate to form a diffusion duct, a propellant inlet mouth and a diffusion outlet mouth, which slot is plugged, on one of the faces of said plate, by the flat face (37) of the tank or by another plate and, on the other of its faces, by the flat face (38) of the distribution chamber or by another plate.   17 / installation according to one of claims 1 to 16, characterized in that each recovery mouth of each color box (21) is provided with a non-return valve (58) opening under the effect of the current gaseous suction, and in that the suction generating device is adapted to generate a flow contrary to the suction flow, called declogging flow, which produces, inside the filter chamber (26), a unclogging gas stream passing through the filter (27) so as to separate from the filter the powder collected by it, and under the effect of which the non-return valve is closed.   18 / Apparatus according to one of claims 1 to 17, characterized in that the filter chamber (26) of each color box comprises a sieve (28), arranged to be able to receive the powder collected by the filter.   19 / Apparatus according to claim 18, characterized in that the sieve is associated with a vibration device.   20 / Apparatus according to claim 19, characterized in that the vibration device is outside the color box and is independent of it.   21 / Apparatus according to claim 20, characterized in that: - the filter chamber (26) has a bottom (29) for recovering the powder at the outlet of the sieve, said bottom being secured to the recycling duct (30) and having lights opening on said recycling duct, the screen (28) being fixedly mounted on said bottom, - the recycling duct (30) has at least a portion, said outer portion, extending outside the housing external (23) of the color box, the vibration device comprises a motorized member (59), said vibration member, which, when the color box is coupled to the paint booth, is supported against an outer portion of the recycling duct is adapted to impose small alternative movements (56) to the recycling duct.   22 / installation according to one of claims 1 to 21, characterized in that it comprises a plurality of paint booths, each booth being adapted to be mounted removably in the paint station.   23 / Apparatus according to claim 22, suitable for painting elongated objects generally cylindrical, characterized in that: - the installation comprises a plurality of paint booths (3, 4, 5, 6), said containment boxes, each containment box being adapted to be traversed by an object, the housing (7) of said confinement box having a dimension in a direction, said axial direction, much smaller than the longitudinal dimension of the object, which housing comprises two axial lumens therethroughs (10, 11) arranged facing each other in the axial direction of the containment box and adapted to allow the passage of the object, - the painting station comprises an elevator (14), said elevator of paint, slidably mounted in a substantially vertical direction, - the installation comprises removable mounting means (17, 15, 16, 72) of a coupled assembly (containment box / color box) on the paint elevator, in a position in which the axial direction of the containment box is substantially parallel to the vertical direction of translation of the elevator, the installation comprises an object conveyor (2), arranged in the upper part of the installation so as to pass over the painting station and provided with suspension members of the objects by a longitudinal end, which conveyor of objects is adapted to maintain stationary at least one object within the paint station, in a position, called painting position, in which the longitudinal axis of the object passes through the axial lumens of a containment box mounted on the paint elevator.   24 / Apparatus according to claim 23, characterized in that the paint station comprises motor means, hydraulic or pneumatic or mechanical displacement of the paint elevator in its direction of translation, and means for adjusting the speed of translation of the paint elevator.   25 / Apparatus according to one of claims 23 or 24, characterized in that it comprises a range of containment boxes comprising: - identical containment boxes, - containment boxes (3, 4, 5, 6) adapted to different object models, - containment boxes adapted to various types of paint finish, - boxes (6), said bi-coloring containment boxes, each comprising: two separation masks (67, 68 ) adapted to define, with an object passing through the containment box in the painting position, two independent confinement chambers (81, 82) each receiving a part of the object, two sets of at least one recovery opening, the (the) opening (s) of recovery of each series opening on one, specific to said series, two confinement chambers, ^ two sets of at least one opening of diffusion entry, ^ two series of at least one spray orifice (77, 78; 80), in which the spray orifice (s) of each series opens (s) on one (81; 82), specific to said series of apertures (s), of the two confinement chambers and is (are) connected (each) to a diffusion inlet aperture of one, specific to said series of apertures, orifice (s), of the two sets of diffusion opening (s).   26 / Apparatus according to one of claims 1 to 25, characterized in that it comprises at least one monoblock device (57), said fast connection device, for connecting a color box (21) to a network of fluids and energies, said fast connection device being connected, on the one hand, at least to the propellant flow generating device and to the suction flow generating device, and on the other hand including branch connectors at least at the inlet (s) of the propellant flow and the suction mouth (s).   27 / Apparatus according to one of claims 1 to 26 and according to claim 23, characterized in that the quick connection device (57) is carried by the paint elevator (14).   28 / Apparatus according to one of claims 1 to 27, characterized in that it comprises: - an area (100) for storing objects, 5o - at least one pretreatment cabin (101, 102), the conveyor of objects being adapted to carry objects through said pretreatment booth from an end opening thereof communicating with an outlet of the storage area to an opposite end opening communicating with the paint station; at least one after-treatment booth (107), the object conveyor being adapted to transport the articles through said post-processing booth from an end opening thereof communicating with the paint station; where appropriate, a zone (109), referred to as a caisson zone, for the storage and maintenance of the containment caissons, comprising at least one cleaning cabin of at least one confinement caisson, means for automatic coupling / uncoupling of a box of e confinement and at least one color box, and means of conveying a coupled assembly (containment box / color box (s)} between the box area and the paint station, - if applicable, automatic assembly / disassembly means of a coupled assembly (containment box / color box (s)} on the paint elevator, - means (114) for automatic handling of the color boxes within the magazine and conveying means (113) for color boxes between the magazine and the paint station or, where appropriate, between the magazine and the box area, - a color box maintenance station (115).   29 / A method of color change in an installation according to claim 1, characterized in that uncoupling of the paint booth a color box initially coupled to said cabin, it cleans the interior of the paint booth, is coupled another color box to the cleaned cabin.   30 / A method of color change in an installation according to claim 23, characterized in that dismounted the coupled assembly (containment box / box (s) of color} initially mounted on the paint elevator, then goes up on the paint elevator is another newly mated confinement box / box (s).   31 / A method of painting elongated objects generally cylindrical in an installation according to claim 23, characterized in that: - there is at least one object within the paint station in the painting position, - a coupled assembly {containment box with color box (s)} being mounted on the paint elevator and each color box (21) of the assembly being connected at least to the propellant flow generating device and the suction flow generating device, an operation, called a diffusion operation, is initiated, which induces the generation of at least one propellant flow and at least one suction flow, and the paint elevator (14) is moved along the object from a first longitudinal end thereof towards its second longitudinal end, the object being held motionless in its painting position, - when the paint elevator arrives at a position in which the second end longitudinal of the object extending in the containment box, it controls at least the propellant stream generating device so as to stop each propulsion flow.   32 / A method according to claim 31, characterized in that: the paint elevator is, prior to the triggering of the diffusion operation, in a low initial position in which a containment box mounted on the elevator extends in below the object, prior to the triggering of the diffusion operation, moving the paint elevator equipped with a coupled assembly {containment box / color box (s)} up along the object to a high position in which the upper longitudinal suspension end of the object extends inside the containment box, - during the diffusion operation, the paint elevator is moved downwards along the object from its upper longitudinal end to its lower longitudinal end.