FR2880556A1 - INDUSTRIAL PAINT INSTALLATION - Google Patents

Abstract

The invention relates to an industrial installation for painting elongated generally cylindrical objects, characterized in that it comprises a plurality of containment boxes (3, 4, 5, 6), whose housing is adapted to be traversed axially by an object and comprises two axial through apertures for the passage of the object, at least one spray orifice that can be connected to a diffusion flux supply duct, at least one recovery opening that can be connected to a flow duct gaseous powder for recovering the powder powder in excess, a lift (14) of vertically sliding paint, on which a containment box can be removably mounted, an object conveyor (2) adapted to hold a stationary object within the paint station, in a position in which the longitudinal axis of the object passes through the axial lumens of a containment box mounted on the paint elevator.

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 invention applies more specifically to the painting of elongated generally cylindrical objects. The term "globally cylindrical" here qualifies an object which is cylindrical in the strict sense of the term (generated by a line that moves parallel to itself on a directional curve) and which therefore has a cross section (perpendicular to the generating line) identical and of any shape throughout the length of the object or, more broadly, an object which has a slightly variable cross section along a longitudinal axis of the object. The installation according to the invention is for example for the painting of metal sheets, beams, metal profiles, such as those used in the manufacture of joinery (window, French window ...), etc.

  Known painting installations usually comprise a painting station in which the objects are presented in a vertical painting position, and an object conveyor arranged in the upper part of the installation so as to pass above the paint station, said conveyor comprising suspension members of the objects.

  Known paint stations include a high-rise painting booth, which may contain at least one whole object (and possibly several whole objects following each other in Indian file). The painting booth is 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.

  Note that there are also painting facilities in which the objects are conveyed through a paint booth in a horizontal painting position, being suspended or carried at their two longitudinal ends. But this known prior art does not give satisfaction: depending on the length of the objects, an arrow more or less important (20 to 30cm for a joinery section of 7m long) may appear, which leads to a residual deformation of the object despite subsequent horizontal storage flat.

  Excess powdered color powder in the cabin is recovered and filtered, on the one hand for recycling, and on the other hand to facilitate the cleaning of the paint booth. Indeed, in case of color change, it is necessary, before projecting the new powder, to clean the interior of the cabin to prevent 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 cabin (and the rest of 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 paint booth during a color change. EP 291 423 proposes for this purpose to cover the lateral internal walls of the cabin by means of a consumable plastic sheet, which is replaced at each color change. WO 02/07442 teaches on the one hand to realize the internal walls of the cabin in a non-conductive material, and on the other hand to equip the cabin with a floor rotatably mounted relative to a suction duct arranged just at above the ground, which floor is also able to slide axially between a sealed position for cleaning under pressure and a retracted suction position of the powder deposited on the ground.

  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 perform 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. Known paint stations (including paint booth, cyclone filtering devices, filters a color powder tank, all powder cabin supply ducts, and powdered powder recovery ducts. excess, etc.) generally occupy a floor area of 100 m2 when it comes to painting metal joinery profiles with a cross section of only a few square centimeters.

  Furthermore, known installations and methods are unsuitable for painting an elongated object comprising two assembled sections, each intended to receive a clean color. Such an object is frequently used for the manufacture of two-color joinery, for example when the color of the external profiles (visible from outside the building) of the carpentry is imposed and that it is desired to leave the choice of the color of the windows. interior profiles (visible from inside the building) from the carpentry to the purchaser or the occupant of the premises. Previous methods of bicolouring, implemented in known paint installations previously described, consist in: painting a series of first profiles in a first color, operating a color change of the installation (and thus cleaning the entire installation, which results in an average immobilization of one hour), paint a series of second profiles in another color, protect each section by means of a film to allow its handling without risk of damage to the layer of paint , assemble the profiles in pairs, remove their protective films. The implementation of these methods is obviously complex and time consuming.

  The invention aims to overcome these disadvantages by proposing a radically different paint installation, in which the painting booth cleaning operations are performed in masked time, are greatly simplified, can be fully automated and allow frequent color changes . The invention extends to a new painting process, which ultimately makes it possible to simplify the color change operations. The invention also aims to propose a new color change method, extremely simple and fast.

  In a preferred version, the invention even aims to provide a paint installation in which a color change only induces immobilization of a few seconds of the installation.

  Another object of the invention is to provide a paint installation in which all of the color change operations, including the cleaning operations of all the elements of the installation exposed to the color powder, can be automated. . In a preferred version, the invention makes it possible to reduce the cleaning operations of the entire installation by simply cleaning the paint booth, which, moreover, is performed in masked time.

  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 painting process which is at least as fast as the previous processes and provide qualitative results (maximum recovery rate of the object, equal thickness of the paint layer ...) at least as satisfactory.

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

  Another object of the invention is to provide an installation and a painting process for painting the same object of two distinct colors (a part of the object receiving a color, the other part of the object receiving another color ), and this, in a single passage of the object within the painting station.

  The invention also aims to allow to implement this specific treatment for an isolated object or for a small number of objects possibly scattered in the production, without penalizing the productivity of the chain. An object of the invention is in particular to provide a quick and easy method for the painting in bi-coloring of an object comprising two assembled sections.

  The invention also aims to allow the realization 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 the production, without this specific treatment does not penalize the productivity of the chain.

  Another objective of the invention is to propose an installation offering a higher powder recycling rate than known prior installations.

  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 paint installation for painting generally elongated cylindrical objects, by means of at least one gaseous flow loaded with color powder, called diffusion flux, projected onto each object. The installation comprises a paint station and an object conveyor arranged in the upper part of the installation so as to pass above the paint station, said conveyor comprising suspension elements of the objects adapted to suspend each object by a longitudinal end thereof called upper end suspension of the object.

  The installation according to the invention is characterized in that: it comprises a plurality of caissons, said confinement caissons, each confinement caisson being adapted to be traversed by an object, said confinement caisson comprising a confinement casing of (A) projected diffusion stream (s) which has a dimension, in a direction said axial direction of the box, very lower (for example at least three times lower) to the longitudinal dimension of said object, which housing comprises: ^ two axial lights therethroughs, arranged facing each other in the axial direction of the containment box and adapted to allow the passage of the object, ^ at least one orifice, said spray orifice, directed towards the inside of the box confinement for the projection of the diffusion flux (es), each spray orifice being connectable to a diffusion flux supply duct, at least one opening, said recovery opening, opening on the outside of the containment box and communicating with the interior of said box, each recovery opening being connectable to a gas flow conduit, said recovery stream, for the recovery of the powder excess pulverized, - the painting station comprises an elevator, said elevator paint, slidably mounted in a substantially vertical direction, - the installation comprises means for removably mounting a containment 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 object conveyor is adapted to keep immovable at least one object within the paint station, in a position , said painting position, in which the longitudinal axis of the object passes through the axial lumens of a containment box mounted on the paint elevator (so that the object can cross the box).

  The invention extends to a method of painting generally cylindrical elongated objects, by means of at least one gaseous flow loaded with color powder, called diffusion flux, projected onto each object. The method according to the invention is characterized in that: - at least one object is disposed within a paint station of an industrial paint installation, in a position, called a painting position, in which the object is suspended by a longitudinal end said upper suspension end, with the aid of a suspension member of an object conveyor arranged in the upper part of the installation so as to pass over the paint station, which post paint comprises an elevator, said elevator paint, slidably mounted in a substantially vertical direction, a confinement box removably mounted on the paint elevator, said confinement box being adapted to be traversed by said object, said containment box comprising a containment casing of the projected diffusion stream (s) which has a dimension, in a direction said axial direction of the box, very inferior. greater than the longitudinal dimension of the object, which 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, - at least one orifice, said spray orifice, directed towards the interior of the confinement box for the projection of the diffusion flux, each spray orifice being connected to a diffusion flux supply duct, at least an opening, said recovery opening, opening on the inside of the containment box, each recovery opening being connected to a gas flow duct, said recovery stream, for the recovery of the powder powder in excess, containment box being mounted 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 longitudinal axis of the object in the painting position passing through the axial lumens of the confinement chamber, - an operation is triggered, called the diffusion operation, which induces the circulation of a diffusion flux in at minus one diffusion flux supply duct and the generation of a recovery flow in at least one recovery flow duct, and the paint elevator is moved along the object from a longitudinal first end of that towards its second longitudinal end, the object being held motionless in its painting position; in doing so, the diffusion flux (es) is (are) projected onto the object by the spraying orifice (s) of the containment caisson and the (s) recovery stream produced (sen) t inside the containment box a suction stream able to carry the powder powder in excess powder, - when the paint elevator arrives at a position in which the second longitudinal end of the object extends into the containment chamber, at least one cut each diffusion stream.

  The invention therefore consists in replacing the traditional, bulky and non-removable painting booth with a small confinement box mounted removably on an elevator, which is moved along the object as and when measure of his painting.

  With each change of color, it is sufficient to replace the containment box previously used by another containment box, new or previously cleaned. The invention thus extends to a color change process in an installation as defined above, in which the containment box initially mounted on the paint elevator is dismounted, then another containment box is mounted on the paint elevator.

  This operation only takes a few seconds. The cleaning of the old containment box is done in the margins of production, in masked time. If the installation is equipped with removable modules for filtering the recovered powder, only the diffusion feed ducts, generally fixed in the installation, remain to be cleaned.

  It thus becomes possible to offer a wide range of 30 low cost colors, the color changes penalizing little productivity.

  The containment boxes may have small dimensions. As a result: - the assembly / disassembly operations of a containment box on the paint elevator are easy; they can be done manually or be automated; when automated, these operations consume little energy (the box to be handled with 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 completely automatically in a cleaning cabin; the recycling rate of the excess powder powder in a containment box according to the invention is much higher than that obtained in the prior painting booths; ; indeed, the spray zone is restricted to a small area around the object, so that almost all of the powder spray reaches the object, and the suction recovery of the excess powder occurs. near the spray ports (compared to the prior cabs which comprise spray nozzles arranged in the upper part of the cabin while the suction is generated at ground level thereof), so that this recovery is maximum.

  Furthermore, it is possible to provide a range of containment boxes comprising: - containment boxes adapted to different models of object; the axial lumens of each box advantageously correspond to one Io 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 a maximum confinement of the powder of sprayed color inside the box; the range of containment boxes comprises, for example, boxes adapted to profiles of profiles, plate models ...; containment boxes adapted to various types of finishing, and in particular boxes adapted to a single-color finish, boxes adapted to a two-color finish (two different colors on either side of a longitudinal plane of the same object), boxes allowing a finish imitating wood, etc. ; identical boxes, to allow a color change within a batch of identical objects.

  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.

  Advantageously, in the process according to the invention: the paint elevator is, prior to triggering the diffusion operation, in a low initial position in which a confinement box mounted on the elevator extends below the object (this position allows either mounting the box on the elevator if an object is already in the painting position and a color change is in progress, or the introduction of the object within the paint station if the box is already mounted on the elevator), - prior to the triggering of the diffusion operation, the paint elevator with a containment box is moved upwards along the object, until a high position in which the upper longitudinal suspension end of the object extends inside the containment box, during the diffusion operation, the paint lift is moved down along the object since its extr upper longitudinal moth-eaten to its lower longitudinal end. he

  The painting of the object is thus done in a downward movement of the elevator. This preferred 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 paint station comprises motor, hydraulic or pneumatic or mechanical means for moving the paint elevator in its direction of translation (substantially vertical). Alternatively or in combination, it is not excluded to manually move the elevator.

  Advantageously and according to the invention, the paint elevator is provided with means for adjusting its translation speed, 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, the diffusion flux (and in particular its flow rate, its powder content, etc.), the type of color powder, the shape of the object and its linear surface, etc ..

  Advantageously and according to the invention, the paint station comprises, below the paint elevator, a gripping member of a longitudinal end of an object, said lower gripping end, opposite its upper suspension end. Said gripping member is slidably mounted in a substantially vertical direction (in order to adjust its position as a function of the length of the object) and has locking means in a gripping position of an object.

  This member makes it possible to keep an object perfectly immobile during the diffusion operation, in order to avoid any risk of sway of the object and any undesirable contact between the object and the containment box and to facilitate the implementation of an operation called bi-coloring operation, which will be described later.

  Advantageously and according to the invention, the casing of at least one containment box and preferably of each containment box comprises at least one opening, called the diffusion inlet opening, opening on the outside of the casing for the connecting the containment box to a diffusion flow supply duct, each spray orifice of the box being connected to a diffusion opening opening of the box. The containment box may have one or more diffusion inlet openings; each spray orifice is connected to a diffusion inlet opening of its own or shared with one or more other spray orifices; the same spray orifice may optionally be connected to a plurality of diffusion inlet openings.

  Advantageously and according to the invention, the casing of at least one containment box and preferably of each containment box comprises: an inner wall, an outer wall, each diffusion inlet opening being formed in the Outer wall, each spray orifice being formed in the inner wall and being connected to a diffusion inlet opening by a conduit, said spray pipe, arranged between the inner and outer walls, each recovery opening passing through the housing ( that is to say both the inner wall and the outer wall); in other words, the recovery opening opens on both the inside and the outside of the containment box; it is for example formed by a pair of facing lights, one formed in the inner wall and the other formed in the outer wall.

  Advantageously and according to the invention, at least one containment box and preferably each containment box comprises a plurality of spray orifices distributed around the axis of the box on the same cross section of the containment box.

  Moreover, for at least one containment box and preferably each containment box, each recovery opening extends below the set of spray orifices of the containment box when said box is mounted on the paint elevator , that these spray orifices are arranged on one and the same cross section or on various cross sections of the box.

  Advantageously and according to the invention, each spray orifice (or at least one of these orifices) of at least one confinement box and preferably of each containment box is provided with an electrode connected to a source of voltage so as to generate an electric field between said electrode and an object that passes through the containment box in the painting position and is connected to a mass. Thus, the containment box can receive and spray electrostatic color powder, the use of which is widespread. The object is for example connected to the earth (mass) via the lower gripping member of the paint station or through the suspension member of the object conveyor.

  Advantageously and according to the invention, each spray duct (or at least one of them) of at least one confinement box and preferably each containment box is made of a material with a tribostatic effect, such as PTFE. (Polytretrafluoroethylene) for example. Thus, the containment box can receive and spray color powder with tribostatic activation.

  The installation according to the invention makes it possible to use both color powders with tribostatic activation as well as powders of electrostatic color. A single containment box, if equipped with tribostatic spray ducts and electrodes, can receive and spray both types of color powder. Note that a deconfinement box without tribostatic ducts can also receive and spray powder with tribostatic activation provided it activates the latter upstream of the box (and for example in its color box defined below).

  Advantageously and according to the invention, in a preferred version of the invention: the installation comprises a box magazine, said color boxes, each containing a color powder (for the painting of objects), each color box with an outer casing, inside said outer casing, a colored powder reservoir, at least one mouth, said flow-thrust 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, at least one mouth, called diffusion outlet mouth, opening on the outside of the housing external, means for supplying, between each propellant flow inlet mouth and a diffusion outlet mouth, the powdered propellant gas flow coming from the reservoir, to form a diffusion flux, inside the housing external, a room re, said filtering chamber, 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 of the filter chamber, said suction mouth being adapted to be connected to a device for generating suction gas flow, at least one mouth, said mouth of recovery, opening on outside the outer housing and communicating with the interior of the filter chamber, the filter being arranged such that (when the suction mouth (s) of the box is (are) connected (s) at a device for generating suction gas flow) the suction stream (s) produced (sen) t, inside the filtering chamber, a gaseous stream, called a suction stream, passing through the filter from each mouth of recovery to a mouth of suction, - each box of neck it is adapted to be coupled, directly and removably, to any of the containment boxes, each outlet outlet of diffusion of said color box being arranged in correspondence with a diffusion inlet opening of said box of confinement so as to be contiguous thereto when the color box and the containment box are coupled together, each recovery mouth of said color box being likewise arranged in correspondence with a recovery opening of said containment box; so that it can be contiguous to the latter when the color box and the containment box are coupled, - the paint elevator is adapted to receive a coupled assembly {containment box / color box}.

  In this preferred version of the invention, during a color change, it is sufficient to disassemble the coupled assembly (containment box / box (s) of color} previously mounted on the paint elevator, to couple a another containment box and at least one other color box, and mount the newly mated containment box / color box (s) to the paint elevator. These operations take only a few seconds, and they are the only operations needed to change the color.

  Indeed, all the elements of the installation exposed to the color powder is found together in the color box and in the containment box. 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 containment box, whose mouths (s) diffusion outlet (s) and aperture (s) respective diffusion are contiguous. No conduit is provided between the color box and the containment box for the supply of the diffusion stream box. Similarly, each excess powder pulverized recovery stream is directly transmitted from the containment box to the color box, the respective recovery opening (s) and recovery mouth (s) are contiguous. No conduit is provided between the color box and the containment 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 since the suction current produced through the mouth (s) of recovery and recovery aperture (s) respectively of the color box and the containment box through the filter (or possibly the filters) of the chamber filter before leaving the color box.

  Thus, no cleaning operation is to be performed for a color change: the only part of the installation to be cleaned is the containment box, and this cleaning is done in masked time; color boxes do not require cleaning, since each box is assigned a color permanently. The invention offers the possibility of offering a wide range of colors, not only because the impact of a color change on the productivity of the chain is negligible, but also because the color boxes according to the invention are space-saving (they can be reduced in size, like containment boxes) and easy to store, in a small space. The entire installation also has a small footprint: cyclones and other prior known filter modules, which were associated with the gigantic former paint booths and had to be cleaned or replaced with each color change, are replaced according to the invention by a small filter chamber built into each color box.

  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.

  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. 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: the casing of each containment box comprises at least one face, called the flat coupling face, in which are provided at least one diffusion inlet opening and at least one recovery opening, the outer casing of each color box comprises a face, called the flat coupling face, conjugate of each coupling face of the containment boxes, 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 a containment box.

  The coupling of a color box and a confinement box is made by simple contact of their flat coupling faces (note that this is also the case in a general version of the invention where the mating face is not necessarily flat or may even be formed of several faces). Means for fixing the box on the box (or vice versa) in this coupling position are advantageously provided.

  Advantageously and according to the invention, the diffusion outlet and recovery outlets of each color box and / or the diffusion and recovery inlet openings of each containment box are provided with sealing members (joined by example) able to ensure an airtightness between said mouths and openings of the box and the box in the coupling position.

  Advantageously and according to the invention, the paint installation 5 comprises at least one containment box, said bicoloration containment box, comprising: two separation masks adapted to delimit, with an object passing through the containment box in the position of paint, two independent containment chambers each receiving a part of the object, two sets of at least one recovery opening, the opening (s) of recovery of each series opening on one, clean to said series, 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) 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), of the two series of opening (s) of broadcast entry.

  Such a box provides a bi-color finish on the object in a single pass of the object within the paint station, and even in a single translation of the paint elevator along the object. The process according to the invention is then characterized in that: - a bi-coloring containment box as previously defined is used, - the diffusion inlet opening (s) of each series is connected to a (or more) diffusion flux supply duct (s) associated with a source of color powder (when the casing is mounted on the paint elevator), which source of color powder is specific to said series of opening (s) of broadcast entry; thus, each confinement chamber receives a color of its own, - (once the object disposed in the painting position and preferably maintained in this position also by the lower gripping member of the paint station) is triggered an operation diffusion device inducing at least two independent diffusion fluxes for each color powder source and generating at least two at least one independent recovery streams for each confinement chamber. In doing so, the longitudinal part of the object located in the first confinement chamber (during the displacement of the containment box) is painted with a first color, while the other longitudinal part of the object (corresponding to the second containment chamber) is painted a second color.

  The use of such a bi-color containment box is particularly advantageous for painting an elongated object comprising two assembled sections, each intended to receive a clean color. In this case, the assembled object is provided (supplied as such by the profile manufacturer, in the case where the two sections of an object are delivered separately, the two sections are assembled beforehand to form the object) in its position. of paint so that each section is located in a confinement chamber, which is its own.

  Thus, unlike known prior methods, the method according to the invention of bi-coloring an object comprising two sections (or other longitudinal parts) assembled, requires no color change operation or any protective operation (by a film) profiles for their assembly. It is summed up in a single operation of diffusion, simple and fast, for the painting of the assembled object. This process can be applied to an isolated object within the production (and not necessarily to a batch of identical objects) without penalizing the productivity of the chain.

  Advantageously and according to the invention, when the installation comprises color boxes according to the invention, each bi-color containment box has a casing comprising two coupling faces, for coupling to said containment box of two boxes. of color. Note that the two coupling faces of said containment box are preferably opposite. Moreover, the spray orifices of each series of orifices of the box are each connected to a diffusion inlet opening of one, specific to said series of orifices, of the two coupling faces. Finally, the paint elevator is adapted to receive a coupled assembly (containment box / two colored boxes).

  Advantageously and according to the invention, the painting 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 and the suction flow generating device, and further comprising branch connectors at least one of the propellant flow inlet mouth (s) and at the suction mouth (s) of a color box.

  The quick connect device is preferably carried by the paint elevator. The installation advantageously comprises at least two quick-connect 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 also comprises: a storage area for the 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 cabin from an end opening thereof communicating with the paint station, the object conveyor preferably also being adapted to transport the objects through the post-treatment cabin in the other direction, an area, known as the box area, for storing and maintaining the containment boxes, comprising at least one cleaning cabin for at least one containment box.

  In a preferred version: the zone of the caissons comprises means for automatic coupling / uncoupling of a containment 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, - the painting station includes means for automatic mounting / dismounting of a coupled assembly (containment box / color box (s)} on the paint elevator, the installation comprises means of automatic handling of color boxes within the store, means of conveying 15 color boxes between the store and the box area and a color box maintenance station.

  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, - Figure 2 is an axial sectional view along the plane AA of a coupled assembly (containment box / color box) according to the invention, - the FIG. 3 is a cross-sectional view along the plane BB of the containment box of FIG. 2; FIG. 4 is a cross-sectional view along the plane CC of the color box of FIG. 2; FIG. is a cross-sectional view along the plane BB of the color box of FIG. 2; FIG. 6 is a perspective view of a bi-coloring containment box according to the invention; FIG. cross-sectional view of part of the ca bi-color containment isson of Figure 6.

  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 objects by spraying a degreasing and / or stripping solution, rinsing with water of the preceding solutions, drying of the products, chromating ...; 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 grip member 18, both slidably mounted in a substantially vertical direction a cabin 107 for post-treatment of objects after their painting, of which an end opening 108 communicates with the paint station 1; the post-processing booth is arranged parallel to the pretreatment booths 101, 102; it is equipped for one or more of the following treatments: drying, firing paint by radiation or convection ...; a color box magazine 22, leaned against the post-processing booth and in which a large range of color boxes 21 can be stored; 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 above the two storage magazines 100, the two pretreatment cabins 101, 102, the paint station 1, the post-processing cabin 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 containment box 3 according to the invention, illustrated in Figures 2 and 3, comprises an outer casing 7 parallelepiped, 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 8 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 containment box has a small axial dimension compared to the length of the objects to be painted. This axial dimension is for example three to ten times less than the length of the objects.

  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 5 of the box on the same cross section (section orthogonal to the axis 5) 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 pipes 20 in order to accelerate (venturi effect) the diffusion flows out of these ducts, for a more targeted powder projection and more effective.

  The containment box 3 is shown (FIG. 2) coupled to a color box 21. It comprises a parallelepipedal outer casing 23 successively enclosing a reservoir 25 containing color powder 24, a distribution plate 32 and a chamber of FIG. The tank, the distribution plate and the filter chamber are also parallelepipedic.

  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 is based on the discs 43. It is articulated on each of these discs by means of a pin 46 housed, on the one hand in an eccentric mortise of the disc of collection arranged at a distance r 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 successively authorizes: the filling of each compartment 50 and therefore 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 - Evacuation of the isolated powder dose when the compartment 50 passes next to a drain hole 36 while the scraper 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 via the diffusion outlet mouth 35 of said duct 33, to penetrate, via a diffusion input opening 19, into a diffusion flow circulation duct 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 screen 28 fixed to a bottom 29 of the chamber. 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 completely open at the top, in order 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 a containment chamber 3 (or 4, 5, 6), 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 powder recovery stream 200 is produced inside the containment box 3 via the suction stream 202. The recovery stream 200 makes it possible to recover the powder powder 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 of the installation each comprise a single recovery mouth 40, which extends over the great majority of their length and cooperates with a single recovery opening 13 of the coupling faces of the boxes confinement. 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 secured to the bottom 29 of the chamber and the recycle conduit 30. It is animated by small vibratory movements via the conduit 30: a vibration device comes, periodically or continuously, apply an alternating force on the one of the outer portions of the recycling duct so as to impose thereon small horizontal displacements embodied by the arrow 56. By way of example, the vibration device comprises a motor shaft and a cam 59 resting on the duct 30 (see FIG. 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 containment box 3 illustrated in FIGS. 1 and 2, suitable for painting carpentry profiles, has, for example, a cross section of 2 m by 2 m (external dimensions), circular axial slots 10, 11 with a diameter of 35 cm, height from 1 to 1.2 m, for profile painting with a maximum transverse dimension of 20 cm and a length of 6 to 7 m. The color boxes of the installation have for example a cross section of 60 cm by 20 cm and a height of 60 cm. For example, the containment box 4 has rectangular axial openings of 160 cm by 5 cm for painting sheet metal having a section of dimensions 150 cm × 2 mm.

  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 colored powders used are, for example, thermosetting powders, particularly suitable for aluminum objects, photocurable powders, and the like.

  The painting process according to the invention takes place 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 object conveyor 2. In this position the axis S 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 quick connection device 57, 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. Note that the coupled assembly {containment box / box (s) of color} is mounted on the paint elevator 14 by means of a mounting plate 17, which on the one hand carries the coupled assembly and d the other is carried by the elevator 14. The coupled assembly is fixed by any suitable means on the mounting plate 17; this operation is performed manually or automatically in the area of the boxes 109. The mounting plate provided with the coupled assembly is fixed on the paint elevator 14 by any appropriate means and the (the) box (s) of color is (are) connected to one (two) device (s) 57 fast connection carried (s) 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 a 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 controlling, executing and controlling painting operations, such as a computer control unit, a powder level detecting device cooperating with a tank detecting member 42, a control and control cable of the speed of rotation of the shaft 45b of the metering device, etc. The paint elevator is equipped with a second quick connection device (not shown) in the case of a bi-coloring operation. 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 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 generation and suction flow generation devices are controlled to deliver propellant flow and suction flow. 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 computer controlled according in particular to 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 painting operations described above (including bringing and positioning the object in the paint station and removal of the object after painting) lasts 50 to 70 seconds if it is desired to make a layer of painting 80 m thick on a carpentry 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).

  In order to change the color, the coupled assembly (containment box / color box (s)} present on the elevator is removed first. 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 / color box (s)} to be replaced, is detached from the elevator 14. A mounting plate is then attached carrying another coupled assembly. {containment box / color box (s)} on the elevator. The mounting plate of this other assembly is preferably another mounting plate 15, 16 or 72, on which the new coupled assembly has been fixed in masked time, for example during the last painting operation, in the box area. The former set (containment box / color box) is then separated 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). Spray ports 77, 78 of the first series are connected to the diffusion inlet openings of a first mating face of the well, 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 applies to all types of object (monobloc or formed of several assembled portions, single material or multi material ...), but it is particularly advantageous for joineries formed of two assembled sections, such as that illustrated, the profiles being painted while they are already assembled.

  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. The invention can be the subject of numerous variants with respect to

  embodiments described and illustrated.

  In particular, the invention is not limited to an installation comprising color boxes. Indeed, the advantage of using containment boxes according to the invention remains intact in the case of an installation comprising a powder supply device (reservoir, fluidization chamber, pump, supply conduit. .) and a conventional independent recycling device (cyclone, filter, suction lines and recycling lines, etc.), which is connected to the containment box (in this case the box recovery openings are connected to recovery flow ducts leading to the recycling device, while its diffusion inlet openings are connected to powder supply ducts connected to the supply device; more generally, the spray ports of the box are connected to diffusion flow supply ducts, each formed by the succession of a spraying duct of the box and a powder supply duct or formed directly by a feed duct if the casing has only one wall and is devoid of spray pipe). Indeed, the fact remains, not only that the cleaning of the containment box can be performed, preferably automatically, in masked time and the downtime of the installation is reduced, but also that the installation is less bulky and less expensive.

  In addition, the numbers of spray ports, diffusion inlet openings and containment box openings are not limited to those provided in connection with the illustrated embodiments.

  Moreover, each containment box may be equipped with electrodes facing its spray ports, for use with electrostatic powder color.

  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 or, more generally, three separate color powder sources. Similarly, it is possible to envisage a quadricoloring 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 (28)

  1 / Industrial installation of paint for painting elongated objects generally cylindrical, by means of at least one gaseous flow loaded with color powder, said diffusion flux, projected on each object, the installation comprising a paint station and an object conveyor arranged in the upper part of the installation so as to pass above the paint station, said conveyor comprising suspension members of the objects adapted to suspend each object by a longitudinal end thereof said upper end suspension of the object, characterized in that: - the installation comprises a plurality of boxes (3, 4, 5, 6), said containment boxes, each containment box being adapted to be traversed by an object, said containment box comprising a casing (7) for confining the projected diffusion stream (s) which has a dimension, in a direction said axial direction (ê) of the box, tr less than the longitudinal dimension of said object, which housing comprises: two axial through-holes (10, 11) arranged facing one another in the axial direction of the containment box and adapted to allow the passage of the object, at least one orifice (12), said spray orifice, directed towards the interior of the containment box for the projection of the diffusion flux, each spray orifice (12) being connectable to a conduit supplying diffusion flux, at least one opening (13), said recovery opening, opening on the outside of the containment box and communicating with the interior of said box, each recovery opening (13) being to be connected to a gas flow conduit, said recovery flow, for the recovery of the powder powder in excess, - the paint station (1) comprises an elevator (14), said 30 paint elevator, slidably mounted in a d irection substantially vertical, - the installation comprises means (17) for removably mounting a containment box (3) on the paint elevator (14), 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 object conveyor (2) is adapted to hold 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 (10, 11) of a containment box (3) mounted on the paint elevator (14).   2 / Apparatus according to claim 1, characterized in that it comprises a plurality of identical containment boxes.   3 / installation according to one of claims 1 or 2, characterized in that it comprises containment boxes (4, 5) adapted to different object models.   4 / installation according to one of claims 1 to 3, characterized in that the paint station (1) comprises motor means, hydraulic or pneumatic or mechanical movement of the paint elevator in its direction of translation.   5 / Apparatus according to one of claims 1 to 4, characterized in that the paint elevator (14) is provided with means for adjusting its speed of translation.   6 / Apparatus according to one of claims 1 to 5, characterized in that the paint station (1) comprises, below the paint elevator (14), a member (18) for gripping a longitudinal end lower part of an object opposite its upper suspension end, said gripping member (18) being slidably mounted in a substantially vertical direction and having locking means in a gripping position of an object.   7 / installation according to one of claims 1 to 6, characterized in that the housing (7) of at least one containment box (3) comprises at least one opening (19), said opening of diffusion entry, opening on the outside of the casing for the connection of the containment box to a diffusion flow supply duct, each spray orifice (12) being connected to a diffusion inlet opening (19).   8 / Apparatus according to claim 7, characterized in that the housing of said containment box comprises an inner wall (8) and an outer wall (9), and in that each opening of the diffusion inlet (19) of the box is arranged in the outer wall (9), each spray orifice (12) is formed in the inner wall (8) and is connected to a diffusion inlet opening (19) via a conduit (20), called a spray pipe , arranged between the inner and outer walls, and each recovery opening (13) passes through the housing (7).   9 / Apparatus according to claim 8, characterized in that the (s) conduit (s) spraying of at least one containment box is (are) a material with tribostatic effect.   10 / installation according to one of claims 1 to 9, characterized in that at least one containment box (3) comprises a plurality of spray orifices (12) distributed around the axis (8) of the box on the same cross section of the containment box.   11 / Installation according to one of claims 1 to 10, characterized in that, for each containment box, each recovery opening (13) extends below the set of spray orifices (12) of the box of confinement when said box (3) is mounted on the paint elevator (14).   12 / installation according to one of claims 1 to 11, characterized in that each spray orifice of at least one confinement box is provided with an electrode connected to a voltage source so as to generate an electric field between said electrode and an object which passes through the containment box in the painting position and which is connected to a mass.   13 / installation according to one of claims 1 to 12, characterized in that: - the installation comprises a store (22) boxes (21), said color boxes, each containing a color powder (24), each color box comprising an outer casing (23), inside said outer casing, a reservoir (25) of colored powder, at least one mouth (34), said flow-thrust inlet, opening on the outside of the outer casing and adapted to be connected to a device for generating a propellant gas flow capable of conveying color powder, at least one mouth (35), called the diffusion outlet mouth , opening on the outside of the outer casing, means (41, 36) for feeding, between each propellant inlet mouth (34) and a diffusion outlet mouth (35), the gas flow propellant powder from the reservoir, to form a diffusion flux, ^ inside the outer casing no, a chamber (26), said filtering chamber, provided with at least one filter (27) capable of retaining at least a portion of the color powder, at least one mouth (39), said suction mouth , opening on the outside of the outer housing and communicating with the inside of the filter chamber, said suction mouth being adapted to be connected to a device for generating suction gas flow, at least one mouth (40), said mouth of recovery, opening on the outside of the outer casing and communicating with the inside of the filter chamber, the filter (27) being arranged in such a way that the gas flow (s) a suction gas stream passing through the filter from each collection mouth to a suction mouth, inside the filter chamber, each color box (21) is adapted to can be coupled, directly and removably, to any one of confinement wings, each diffusion outlet mouth (35) of said color box being arranged in correspondence with a diffusion inlet opening (19) of said containment box so as to be contiguous thereto when the box of diffusion color and the containment box are coupled, each recovery mouth (40) of said color box being arranged in correspondence with a recovery opening (13) of said containment box so as to be contiguous thereto when the box of color and the containment box are coupled, - the paint elevator (14) is adapted to receive a coupled assembly {containment box / color box}.   14 / Apparatus according to claim 13, characterized in that the diffusion inlet openings (19) and recovery (13) of each containment box (3, 4, 5, 6) are provided with sealing members adapted to provide a gas seal between said openings and the corresponding diffusion outlet and recovery outlets of a color box coupled to the containment box.   15 / installation according to one of claims 13 or 14, characterized in that each color box (21) comprises at least one duct (30), said recycling duct, connecting the filter chamber (26) and the tank of powder (25).   16 / installation according to one of claims 13 to 15, characterized in that: - the housing of each containment box comprises at least one face (55), said flat coupling face, in which are provided at least one diffusion inlet opening (19) and at least one recovery opening (13), - the outer housing (23) of each color box comprises a face (48), referred to as a flat coupling face, conjugate with each the coupling face 30 of the containment boxes, and in which are provided each diffusion outlet mouth (35) and each recovery mouth (40) of the color box so as to correspond to the opening (s) of entry of diffusion and opening (s) of recovery of a coupling face of a containment box.   17 / installation according to one of claims 1 to 16, 5 characterized in that the installation comprises at least one containment box (6), said bi-color containment box, comprising: - two separation masks (67 , 68) adapted to define, with an object passing through the containment box in the painting position, two independent containment chambers (81, 82) each receiving a part of the object, - 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 series of at least one spray orifice, in which the spray orifice (s) (77, 78) of each series opens on one (81), specific to said series of orifice (s), of the two containment chambers and is (are) connected (each) to a delivery entrance opening n of one, specific to said series of orifice (s), two sets of opening (s) of diffusion input.   18 / installation according to claims 16 and 17, characterized in that: - each bi-coloring containment box (6) has a housing comprising two coupling faces, for coupling to said containment box of two color boxes the spray orifices (77, 78, 79, 80) of each series of orifices of the box being each connected to a diffusion inlet opening of one, which is adapted to said series of orifices, of the two faces of - The paint lift is suitable for receiving a coupled assembly (containment box / two colored boxes).   19 / Apparatus according to one of claims 1 to 18 and according to claim 13, characterized in that it comprises at least one monoblock device (57), said fast connection device, for connecting a box of color 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 further comprising connectors connecting at least the at least one propellant inlet mouth (s) and the suction mouth (s) of a color box.   20 / Apparatus according to claim 19, characterized in that the quick connection device is carried by the paint elevator.   21 / Apparatus according to one of claims 1 to 20, characterized in that it comprises: - a zone (100) for storing objects, - at least one pretreatment cabin (101, 102), the conveyor of objects (2) being adapted to transport objects through said pretreatment booth from an end opening (103, 104) thereof communicating with an exit from the storage area (100) to an opposite end opening communicating with the paint station (1), - at least one post-processing cabin (107), the object conveyor being adapted to transport the objects through said post-treatment cabin from an end opening (108). ) of the latter communicating with the paint station (1), - an area (109), said box area, storage and maintenance of the containment boxes, comprising at least one cleaning cabin (110) of at least a containment box.   22 / Apparatus according to claims 13 and 21, characterized in that: - the box area (109) comprises means for automatic coupling / uncoupling a containment box and at least one color box, and conveying means of a coupled assembly (containment box / color box (s)} between the zone of the boxes and the paint station, - the installation comprises means (114) for the automatic handling of the colored boxes at the within the store, means (113) for conveying color boxes between the store and the area of the boxes and a station (115) for maintaining the color boxes.   23 / A process for painting generally cylindrical elongated objects by means of at least one gaseous flow loaded with colored powder, referred to as the diffusion flux, projected on each object, characterized in that: - at least one object is disposed at in a painting station (1) of an industrial painting installation, in a position, called painting position, in which the object is suspended by a longitudinal end called said upper suspension end, with the aid of a suspension member of an object conveyor (2) arranged in the upper part of the installation so as to pass above the paint station, which paint station comprises an elevator (14), said paint elevator slidably mounted in a substantially vertical direction, a containment box (3) removably mounted on the paint elevator, said containment box being adapted to be traversed by said object, said containment box c omprenant a housing (7) for confinement of (the) projected diffusion flux (s) which has a dimension, in a direction (5) said axial direction of the well, much lower than the longitudinal dimension of the object, which housing comprises two axial thru-holes (10, 11) arranged facing one another in the axial direction of the containment box and adapted to allow the passage of the object, at least one orifice (12), said spray orifice, directed towards the inside of the containment box for the projection of the diffusion flux, each spray orifice being connected to a diffusion flux supply duct, at least one opening (13), said recovery opening, opening on the inside of the containment box, each recovery opening being connected to a gas flow conduit, said recovery flow, for the recovery of the powder powder in excess, the box of confineme nt (3) being mounted on the paint elevator (14) 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 longitudinal axis of the object in position of paint passing through the axial lumens (10, 11) of the containment chamber, - an operation is triggered, called the diffusion operation, which induces the circulation of a diffusion flux in at least one flow feed duct. diffusing and generating a recovery stream in at least one recovery stream conduit, and moving the paint elevator (14) along the object from a longitudinal first end thereof to its second end longitudinal, the object being held still in its painting position, - when the paint elevator arrives at a position in which the second longitudinal end of the object extends into the confinement chamber t, cut at least each diffusion stream.   24 / painting process according to claim 23, characterized in that: - the paint elevator (14) is, prior to the triggering of the diffusion operation, in a low initial position in which a containment box mounted on the elevator extends below the object, - prior to the triggering of the diffusion operation, moving the paint elevator with a containment box upwardly along the object, up to a high position in which the upper longitudinal end of the suspension 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.   25 / A method of painting according to one of claims 23 or 24, for the painting bi-coloring of an object, characterized in that: - one uses a containment box (6), said containment box of bi -coloration, comprising: ^ two separation masks (67, 68) adapted to delimit, with an object passing through the containment box in the painting position, two independent confinement chambers (81, 82), 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 confinement chambers, two sets of at least one inlet opening two sets of at least one spray orifice, in which the spray orifice (s) of each series open on one of said two chambers, which is adapted to said series of orifices; containment and are each connected to a diffusion inlet opening of one, specific to the said series of orifices, of the two series of opening (s) of diffusion entry, - one connects the (the) opening (s) diffusion of each series to one (or more) conduit (s) of diffusion flux supply associated with a source of color powder, which source of color powder is specific to said series of diffusion entry aperture (s), an inducing diffusion operation is triggered at least two independent diffusion streams, at least one for each color powder source, and generating at least two independent suction flows, at least one for each containment chamber.   26 / A method of painting according to claim 25, for the painting in bi-coloring of an object comprising two assembled sections, characterized in that the assembled object is arranged in its painting position so that each section is located in a confinement chamber, which is his own.   27 / A method of color change in an industrial installation for painting elongated generally cylindrical objects, the installation 30 comprising: - a paint station (1) comprising an elevator (14), said paint elevator, slidably mounted according to a substantially vertical direction, - a plurality of boxes (3, 4, 5, 6), said containment boxes, each containment box being adapted to be traversed by an object, said containment box comprising a housing (7) containment projected diffusion flux (es) which has a dimension, in a direction said axial direction (S) of the box, much smaller than the longitudinal dimension of said object, which housing comprises: two axial through apertures (10, 11 ), arranged facing each other in the axial direction of the containment box and adapted to allow the passage of the object, at least one orifice (12), said orifice spray n, directed inwardly of the containment box for the projection of the diffusion flux, each spray orifice (12) being connectable to a diffusion flux supply duct, at least one opening (13) ), said recovery opening, opening on the inside of the containment box, each recovery opening (13) being connectable to a gas flow conduit, said recovery stream, for the recovery of the powder powder in excess , means (17) for removably mounting a containment box (3) on the paint elevator (14), in a position in which the axial direction of the containment box is substantially parallel to the vertical direction of translation of the elevator, - an object conveyor (2) arranged in the upper part of the installation so as to pass over the paint station, said conveyor comprising suspension members of the objects adapted to suspend each object. jet by a longitudinal end thereof called upper end suspension of the object, the object conveyor being adapted to hold an object immobile within the paint station (1), in a position, said painting position, wherein the longitudinal axis of the object passes through the axial lumens (10, 11) of a containment box (3) mounted on the paint elevator (14).   a method in which the containment box (3) initially mounted on the paint elevator (14) is disassembled and a further containment box (4, 5, 6) is mounted on the paint elevator.   28 / A method of color change according to claim 27, in an industrial paint installation comprising: - a magazine (22) of boxes (21), called color boxes, each containing a color powder (24), each box of color comprising an outer casing (23), inside said outer casing, a reservoir (25) of colored powder, at least one mouth (34), said mouth of the flow inlet, opening on the outside of the outer casing and adapted to be connected to a device for generating a propellant gas flow capable of conveying color powder, at least one mouth (35), called the diffusion outlet mouth, opening, on the outside of the outer casing, supply means (41, 36), between each propellant flow inlet mouth (34) and a diffusion outlet mouth (35), of the propellant gas flow in powder from the reservoir, to form a diffusion stream, inside the outer casing, a chamber (26), said filtering chamber, provided with at least one filter (27) capable of retaining at least a portion of the color powder, at least one mouth (39), said mouth suction nozzle, 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 suction gas flow, at least one mouth (40), called the recovery mouth, opening on the outside of the outer casing and communicating with the inside of the filter chamber, the filter (27) being arranged so that the (s) suction gas stream produced (sen) t, inside the filter chamber, a suction gas stream passing through the filter from each recovery mouth to a suction mouth, - each color box (21) being adapted to be coupled, directly and removably, to any of the containment boxes, each diffusion outlet mouth (35) of said color box being arranged in correspondence with a diffusion inlet opening (19) of said containment box so as to be contiguous to this last when the color box and the containment box are coupled, each recovery mouth (40) of said color box being arranged in correspondence with a recovery opening (13) of said containment box so as to be contiguous to this last when the color box and the containment box are coupled, - the paint elevator (14) being adapted to receive a coupled assembly (containment box / box (s) of color}, in which method is dismantled the coupled together (containment box / color box (s)} previously mounted on the paint elevator (14), another containment box is coupled to the minus another color box, the newly assembled mating box / box (s) is mounted on the paint elevator.