EP0034687B1 - Automatic machine for projecting coating material - Google Patents

Abstract

1. Device for automatically projecting coating products, comprising a mobile projection head (4, 10) animated by a control mechanism (23) and comprising product supply means connected to a reserve of product and means (20, 21) for controlling the atomization of said product connected to a source of atomization fluid, said projection head comprising on the one hand a single control unit (4) adapted to be animated by said control mechanism (2, 3) and comprising said atomization control means (20, 21) connected to said source of atomization fluid and on the other hand a plurality of interchangeable projection units 10, each associated with a product to be projected and comprising supply means (11) connected to a reserve of the corresponding product, a projection unit (10) being able to be removably mounted on said control unit (4) so that the different control connections may be established between said units, the different interchangeable projection units (10) being disposed in a magazine 8, characterized in that the control unit (4) is provided with means (34) for automatically gripping, locking, unlocking and depositing each time one of said projection units in said magazine.

Description

The present invention relates to automatic devices for spraying coating products such as paints, enamels, fibrous products, etc.

Many mechanical, pneumatic, hydraulic and / or electrical devices are already known for spraying coating products. These known devices comprise a single movable projection head, driven by a suitable mechanism and provided with a single supply of product to be sprayed.

However, these automatic devices are often intended to successively apply different products (for example paints of different colors) on objects, for example continuously scrolling past said projection devices. Also, to switch from the projection of one product to that of another, it is necessary to start by stopping the supply of the spray head with this first product, then rinsing the product circuit of this spray head by means of a solvent, to remove said solvent, to establish the supply of the head with the next product and to carry out the cycle of application of this next product to the object to be received.

These known devices with a single projection head have many drawbacks.

First of all, the sequential process of changing the spray product is very time consuming. However, the time factor is important in the case of application at a high production rate, such as for example in the case of body painting or of automobile body parts, since time can be imposed by the high speed. of the conveyor or chain scrolling one behind the other the various objects to be coated, as well as by reducing the distance separating, on said conveyor, two consecutive objects. This sequential process involves a stack of phases which is difficult to reduce, even if the necessary steps are taken to reduce the length of the product passages and even if the automatic shade or product changing devices are positioned at the closer to the projection device.

In addition, this sequential process has the drawback of forcing the product which has just been sprayed from the projection head, a product which is not recovered, which results in losses of product which can be given the frequency of change and the quantity emptied each time, very expensive, even economically unacceptable.

Furthermore, the rinsing operation requires the use of expensive solvents and sometimes detrimental to the life of certain parts of the projectors. Solvents loaded with particles from the previous product become unusable and must therefore be discharged into the waste with the excess product rinsed, which accelerates the pollution of said waste.

To these drawbacks is added that which has the effect of contaminating the next object with particles of the products applied to the previous objects. Indeed, a product projection head works in an atmosphere of atomized product and inevitable deposits are formed on this single head. The importance of these deposits is infinitely variable with the quality of the projection head, the volume of product applied and the quality of the ventilation of the speakers in which the projection head works. The fact remains that the risk of contamination is present and that it results in manufacturing waste which can be very expensive depending on the importance of the objects treated.

In addition, to this list of drawbacks, it should be added that disparities in adjustment of the projection head may be made necessary by the successive use of products whose physical characteristics may vary according to the colors, for example. As such adjustments are not possible with devices with a single projection head, users of such devices are currently obliged to ask their product supplier for similar physical characteristics for all the products to be projected, while the preparation of the products of different colors do not necessarily have the same formulations, in particular in the case of multi-component products.

To overcome these drawbacks, one could think of designing a projection device comprising as many independent projection heads as there are products to be sprayed. But then, such a device would become very complex, since for certain applications, it would be necessary to provide up to twenty heads.

Furthermore, US-A-2 344 108 relates to an automatic device for spraying coating products overcoming both the drawbacks of devices with a single projection head and the complexity of a possible device comprising a plurality different projection heads.

This automatic device for the projection of coating products comprises a mobile projection head animated by a control mechanism and comprising means for supplying the product connected to a reserve thereof and means for controlling the spraying of said product connected to a source of spray fluid, said spray head comprising on the one hand a single control block capable of being animated by said control mechanism and comprising said spray control means connected to said source of spray fluid and d secondly a plurality of interchangeable projection blocks each associated with a product to be projected and comprising means supply connected to a reserve of the corresponding product, a projection block can be removably mounted on said control block so that the different control links can be established between said blocks, the different interchangeable projection blocks being arranged in a store.

The object of the present invention is to improve an automatic device of this type.

To this end, according to the invention, the automatic device for spraying coating products, of the type mentioned above, is characterized in that said control block is provided with means for gripping, locking, unlocking and the automatic removal each time of one of said projection blocks in said store.

The magazine and the control block are animated with a relative movement with respect to each other so that, according to a determined programming or by manual control, the control block can be associated with a determined projection block.

For example, the magazine is mobile and is capable of bringing a determined projection block to a reference position, where it can be automatically mounted on the control block.

If the projection device according to the invention receives the order to change the product to treat an object that presents itself, it returns the control unit to the reference position and there then occurs a mechanical, pneumatic, hydraulic or electric transfer ensuring in a very short time: 1 ° the disconnection of the projection block used until then with the corresponding product and its deposit in the store, 2 ° the connection of the desired projection block with the control block. The device is then ready to start the work cycle of the object to be treated with the new product.

Thanks to the device according to the invention, all the drawbacks mentioned above are eliminated, and this device makes it possible to envisage solutions for the projection heads which were then unthinkable for conventional projector machines and in particular traffic. continuous products or colors in the projection head, which is recommended for certain applications of delicate products or heated products.

While the work is being carried out on an object, the programming or the manual display makes it possible to automatically search in the store for the projection block which will be necessary for the machine to process the next part or more exactly the next object which will require the change product or shade.

It will be noted that the store receiving the projection blocks can be located in the enclosure where the projection device operates, and that it can, depending on the intensity which is made of it, include a cleaning system in closed circuit making it possible to work at each cycle with a cleaned projection block and this even if the product does not have to be changed, the store can receive several blocks provided for the same product.

Preferably, the junction or separation of the fluid circuit of a projection block with that of the control block is done by simple interlocking or disengagement, the control block comprising means for supporting and locking the projection block.

The projection blocks can advantageously be designed so that the spraying and the control of the spraying of the product are carried out by means of a fluid, for example pneumatically. However, in an alternative embodiment, it is possible to conceive that, although the spraying is obtained by means of a fluid, the spraying control is carried out by a means other than pneumatic, for example electric. In this case, it would be necessary to provide an electrical connector between the control unit and the projection units.

• La figure 1 montre schématiquement, de l'arrière et en perspective, un exemple de réalisation d'un dispositif selon l'invention.
• La figure 2 est une vue de face du dispositif de la figure 1.
• La figure 3 est une vue de côté du dispositif des figures 1 et 2.
• La figure 4 est une coupe en vue longitudinale du corps de commande du dispositif selon l'invention.
• Les figures 5 et 6 sont respectivement des vues de dessus et de face du bloc de commande de la figure 4.
• La figure 7 est une vue de côté d'un bloc de projection pour le bloc de commande des figures 4 à 6.
• Les figures 8 et 9 sont respectivement des coupes selon les lignes VIII-VIII et IX-IX des figures 7 et 8.

The figures of the appended drawing will make it clear how the invention can be implemented.

• Figure 1 shows schematically, from the rear and in perspective, an embodiment of a device according to the invention.
• Figure 2 is a front view of the device of Figure 1.
• FIG. 3 is a side view of the device in FIGS. 1 and 2.
• Figure 4 is a sectional longitudinal view of the control body of the device according to the invention.
• FIGS. 5 and 6 are respectively top and front views of the control unit of FIG. 4.
• FIG. 7 is a side view of a projection block for the control block of FIGS. 4 to 6.
• Figures 8 and 9 are respectively sections along lines VIII-VIII and IX-IX of Figures 7 and 8.

The device according to the invention, shown in Figures 1 to 3, is for example intended to spray paint on parts P _l , P _Z , P ₃ , etc., transported by a conveyor 1, so as to scroll in continuous in front of said device. This comprises a frame 2, inside which is provided a mechanism (not shown) capable of suitably moving an arm 3 at the end of which a control body 4 is articulated, around a joint 5. In the example shown, it is assumed that the arm 3 can move vertically along the arrows F and that the control unit 4 can pivot around the joint 5 and that these movements can be obtained by any known means. Of course, this example should not limit the invention to a vertical automatic machine. It will be understood from the description below that the invention relates to any device automatic handling of a product projector.

By flexible pipes 6 and 7 (not shown in Figure 2), the control unit 4 can be connected to a pneumatic source.

At the lower part of the frame 2 is provided a magazine 8 on which a drawer 9 is slidably mounted, movable horizontally in the two directions of the double arrow f, the path of the drawer 9 crossing that of the arm 3. The drawer 9 serves as a magazine to a plurality of projection blocks 10, numbered from 10 _l to 10 _n and of which the one bearing the reference 10, is shown mounted on the control block 4.

Each projection block 10 is connected by a flexible pipe 11 _l to 11 _n , passing through a reel 12, with corresponding 12 _n , housed in the magazine 8, to an associated paint reserve (not shown).

The parts P ₁ , P ₂ , P ₃ , ..., which are for example automobile body parts, pass continuously by means of the conveyor 1 in front of the device according to the invention, animating the arm with an adequate movement 3 and the interchangeable projection block 10 _i . Each part P ₁ , P ₂ and P ₃ must for example be painted with a different shade. The part P ₁ is for example painted with the tint X associated with the projection block 10, currently at work. The part P ₂ must be painted with a tint Y associated with the projection block 10 ₃ , currently at rest in the magazine 9, while the part P ₃ must be painted with a tint Z, associated with the projection block 10 ₁ , also at rest in store 9.

When the part P ₁ is fully painted, according to a cycle programmed in advance, the device stops in the rest position.

Thanks to a reading device 13, connected to the painting device by a line 14 and reading magnetic labels 15 associated with each part P ₁ , P ₂ , P ₃ , ..., the automatic painting device knows that the part P ₂ must receive the shade Y with which the projection block 10 ₃ is associated.

The articulated control unit 4, moved by the arm 3, then comes to rest the projection unit 10 _j , previously used, in its housing 16 which has remained free in the magazine 9, facing the trajectory of said control unit 4. At this Indeed, the locking device provided between the control unit 4 and the projection unit 10 is unlocked, while, as will be seen below, the control air and the spray air, passing respectively through the flexible conduits 6 and 7 are cut by means of solenoid valves or similar cut-off elements. The flexible pipe 11, bringing the paint to the block 10, disappears in the magazine 8, by means of the corresponding individual reel 12 _i .

The mobile magazine 9 then receives the order to come index, opposite the control unit 4, the new projection unit 10 ₃ corresponding to the new shade Y. This operation is preferably carried out by a hydraulic transfer device, but which could also be pneumatic, electric, etc.

The locking device of the control unit 4 then locks on the projection unit 10 ₃ and simultaneously the spraying air and the control air supplying the control unit 4 are opened. This control block 4, supporting the new projection block 10 ₃ is returned to the working position by the arm 3 and the device according to the invention is ready to paint the part P ₂ with the shade Y.

At the same time, a cleaning device 17 is put into action to clean the head 10, which has just been deposited in the magazine 9.

Such a cycle is renewed each time, it is necessary to change the shade and therefore the projection block 10.

The interchangeable projection heads 10 incorporate a valve for controlling the passage of the normally closed product, the opening of which is controlled by the control unit 4, by means of the control air acting on a pneumatic translation device.

FIGS. 4 to 6 show an exemplary embodiment of a control block 4.

This control unit 4 comprises a body 18, provided with articulation pins 19, forming a part of the articulation 5 on the arm 3. The underside of the body 18 comprises two end pieces 20 and 21, intended respectively for the connection of flexible pipes. 6 and 7, for control air and atomizing air. The end piece 20 is connected by an elbow to a conical bore 22, arranged in the front face of the body 18. Similarly, the end piece 21 is connected by a bend to a conical bore 23, also arranged in the front face of the body 18.

Forward, the body 18 is extended by a support 24 for a spray block 10 (see FIG. 4).

Inside the body 18 are provided two independent chambers 25 and 26, forming a cylinder for pistons 27 and 28. The piston 27 is double-acting, the chamber 25 being able to be supplied with fluid under pressure on either side of said piston through supply ports 29 and 30. The piston 28 is single acting but acts against the action of a spring 31, the chamber 26 being supplied with pressurized fluid through a port d 'supply 32. The ports 29, 30 and 32 are connected to a source of pressurized fluid by pipes not shown in the figures.

Forward, the piston 27 is extended by a hollow piston rod 33, at the end of which jaws 34 are articulated which can pivot around transverse axes 35.

Likewise, the piston 28 is extended forward by a piston rod 36, passing coaxially through the piston rod 33 in order to be able to control by its end 27 the rotation of the jaws 34.

As shown in FIGS. 7 to 9, each spraying block 10 comprises a body 38 provided with notches 39 for gripping by the curved ends of the jaws 34. The underside of the body 38 carries a nozzle 40 for connection to the pipeline flexible 11 corresponding paint supply. This nozzle feeds through an orifice 41, a spray head 42 of known structure, disposed on the front face of the body 38 and provided with a control needle 43, actuated by a piston 44, arranged in a chamber 45 forming a cylinder. The rear face of the body 38 has two conical end pieces 46 and 47. The end piece 46 is connected by a conduit 48 to the chamber 45, on the side of the piston 44 opposite to a spring 49, tending to close off the head 42 by means of the needle 43. The nozzle 47 is connected by a conduit 50 to the spray head.

All of Figures 4 to 9 operate as follows. When it is desired to take a head 10 from the magazine 9 (the positioning and indexing conditions being fulfilled), it is ensured that the chamber 26 of the control unit 4 is not supplied with pressurized fluid, so that the spring 31 pushes to the right of FIG. 4, the piston rod 36 relative to the piston rod 33. This results in a tilting of the jaws 34 corresponding to the opening of these. Pressure fluid is then introduced into the chamber 25, through the orifice 30, so that the piston 27 moves to the right of FIG. 4 and that the ends of the jaws 34 can come opposite the notches 39 of a block 10 'arranged in alignment. If the supply of fluid to the chamber 25 is stopped through the orifice 30 and this fluid is now introduced therein, through the orifice 29, the piston 27 retracts, the jaws 34 become close and grasp the projection block 10 by pulling it on the support 24 until the end pieces 46 and 47 fit into the bores 22 and 23.

The block 10 is locked in the jaws 34 by the pressurized fluid introduced into the chamber 26 through the orifice 32.

The corresponding spray head 42 can then be supplied with control air and spray air via the connections 20-22, 46-48, 21-23 and 47-50, in order to be able to work in the manner described above.

At the end of the work of the head 10, it is understood that it can be deposited again in the magazine 9, after having suppressed the arrival of the fluid at 32 and having supplied the chamber 25 through the orifice 30.

Claims (9)

1. Device for automatically projecting coating products, comprising a mobile projection head 4, 10 animated by a control mechanism 23 and comprising product supply means connected to a reserve of product and means 20, 21 for controlling the atomization of said product connected to a source of atomization fluid, said projection head comprising on the one hand a single control unit 4 adapted to be animated by said control mechanism 2, 3 and comprising said atomization control means 20, 21 connected to said source of atomization fluid and on the other hand a plurality of interchangeable projection units 10, each associated with a product to be projected and comprising supply means 11 connected to a reserve of the corresponding product, a projection unit 10 being able to be removably mounted on said control unit 4 so that the different control connections may be established between said units, the different interchangeable projection units 10 being disposed in a magazine 8, characterized in that the control unit 4 is provided with means 34 for automatically gripping, locking, unlocking and depositing each time one of said projection units in said magazine.

2. Device according to Claim 1, characterized in that the control unit 4 is animated by a rectilinear movement and in that the magazine 8 is a drawer of which the direction of slide is transverse to the movement of the control unit 4.

3. Device according to one of Claims 1 or 2, characterized in that the gripping means 34 are constituted by pincers of which opening and closure, as well as extension and retraction are controlled by a fluid under pressure.

4. Device according to any one of Claims 1 to 3, characterized in that the assembly and dismantling of a projection unit and of a control unit is effected by simple interlocking.

5. Device according to any one of Claims 1 to 4, in which each projection unit 10 presents the structure of a pneumatic gun, characterized in that the control unit 4 comprises means 45, 47 for connection to a pneumatic source both for the atomization air and for the air controlling the needle 43 of said gun.

6. Device according to any one of Claims 1 to 5, characterized in that the pneumatic connections between the control unit and a projection unit are effected by fitting ends of pipes 46, 47.

7. Device according to any one of Claims 3 to 6, characterized in that the gripping means 34 are lockable by a fluid pressure.

8. Device according to any one of Claims 1 to 7, characterized in that a device 17 for cleaning the projection units is provided in the magazine 8.

9. Device according to any one of Claims 1 to 8, characterized in that the connections between the projection units 10 and the sources of corresponding products are formed by flexible pipes 11 associated with automatic winding means 12.

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