EP2658660A1

EP2658660A1 - Paint booth for painting plants for products

Info

Publication number: EP2658660A1
Application number: EP11810849.7A
Authority: EP
Inventors: Gianni GIARDINI
Original assignee: Trasmetal SpA
Current assignee: Trasmetal SpA
Priority date: 2010-12-28
Filing date: 2011-12-28
Publication date: 2013-11-06
Also published as: IT1403188B1; ITBG20100068A1; WO2012089789A1; WO2012089787A1

Abstract

A paint booth (1, 2, 3) for powder painting plants for products characterized in that it comprises: a supporting structure (10), a base surface (20), one or more walls (31,34)that define a painting area (50), first dispensing means (51) for dispensing powder paint facing into said painting area (50), said first dispensing means (51) being operatively connected to first movement means (511) and comprising a first plurality of guns (510) aligned along a first vertical axis, said guns (510) being spaced at a first distance when positioned ina first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenanceposition.

Description

PAINT BOOTH FOR PAINTING PLANTS FOR PRODUCTS

DESCRIPTION

The present invention relates to an improved paint booth for applying powder paints, in particular for automated coating plants for products that use powder paint dispensing means comprising at least two guns positioned opposite one another.

As it is known, painting plants for products dedicated to the use of powder paints are provided with one or more booths in which the product is subjected to one or more series of coatings, for example one or more painting stages and/or one or more stages of baking/crosslinking with IR or UV lamps, or with hot air or induction heating.

Booths, in particular in the case of electrostatic powder painting, normally have a structure comprising a frame or framework which supports a plurality of walls positioned in such a manner that their internal surface defines a space adapted to house one or more dispensers of painting materials. Painting takes place by making the products to be treated pass through the space inside the booth so that they are exposed to dispensing of the powder by means of specific dispensing means. The dispensing means are in turn moved, for example along a vertical axis, in such a manner as to coat the whole surface of the product.

The structure of the booth, and in particular of the walls, is intended to perform two fundamental functions. A first function relates to the need to have deposition surfaces on which the powder that does not adhere to the product, or which is not drawn up by the suction system, can deposit, so as to prevent its diffusion in the surrounding environment. A second function relates to the need to remove the unused powder from the walls on which it has deposited, in order to recover and reuse said powder, and above all in order to prevent the powder from detaching from the walls and depositing on products during subsequent painting operations with different colours, contaminating their final colouring.

For this purpose, there are known in the art different solutions for cleaning the surfaces and the space inside the booths which, although allowing adequate removal and recovery of the powders, have some disadvantages.

In particular, a first solution consists simply of operations carried out manually by operators, who remove the powder deposits from the walls and from the space inside the booth. An alternative, also carried out manually, instead involves removal and replacement of the sheets at each colour change. However, it is evident that although these solutions are effective, they have a negative impact on production times and costs and oblige the operator to work in an unhealthy environment.

In order to avoid operations carried out manually, other solutions involve the use of walls made with movable sheets, generally made of deformable material such as plastic sheets which, through specific actuation systems, are moved in relation to the system for removal of the powder paint. Although this solution enables elimination of the operation carried out manually by operators and relatively effective removal of the powder, it still has some drawbacks.

In particular, cleaning of the powder delivery devices, for example constituted by paint guns or dispensers in general, is an operation which is normally carried out manually.

Additionally, in prior art painting booths, the maintenance and/or emptying and/or colour change operations are normally carried out in the operating position, i.e. when the powder delivery devices are positioned at a height inside the booth. This requires the presence of an external structure to enable operators to access the operating position of the powder delivery devices at height, with related safety concerns.

Moreover, the times required for the maintenance and/or emptying and/or colour change operations are relatively long, thereby decreasing the potential plant productivity.

Therefore, in general, booths of known type have the problem of the relatively long times required for management of the operations to clean and/or empty the powder delivery devices at each colour change operation.

Moreover, when the shape of the products to be painted is complicated, it is normally necessary to provide a high number of powder delivery devices in order to have an optimum coating of said products or to carry out a finishing coating treatment of the products outside the booth, in order to have a uniform coating of said products.

The main aim of the present invention is to produce a paint booth, and in particular a paint booth for automated powder painting plants for products, which enables the above problems to be overcome.

Within this aim, an object of the present invention is to produce a paint booth which does not require, or in any case minimizes, cleaning operations carried out manually.

Another object of the present invention is to produce a paint booth in which the time for management of the operations to empty the powder delivery devices and change the colour is minimized.

Yet another object of the present invention is to produce a paint booth in which the paint dispensing devices are moved in an optimum way, in order to allow painting of parts even of considerable longitudinal dimensions, minimizing the times required for emptying and/or maintenance of these dispensing devices.

Last but not least object of the present invention is to produce a paint booth, and in particular a paint booth for automated painting plants for products which is highly reliable, relatively simple to produce and with competitive costs.

This aim, and these and other objects which shall be more apparent below, are achieved by a paint booth for powder painting plants for products characterized in that it comprises: a supporting structure, a base surface, one or more walls that define a painting area, first dispensing means for dispensing powder paint facing into said painting area, said first dispensing means being operatively connected to first movement means and comprising a first plurality of guns aligned along a first vertical axis, said guns being spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position.

In this way, contrary to prior art booths, in which the maintenance and/or emptying and/or colour change operations are normally carried out in the operating position, in the booth according to the invention these operations are conducted in proximity of the base surface, thus reducing the times for the operation and eliminating the need for superstructures to enable operators to access the operating position of the paint dispensing means at height, especially when these are positioned at greater heights to those accessible to an operator standing on the ground.

In practice, in case of maintenance and/or emptying and/or colour change operations, the guns are grouped together at a distance which is lower than their operating distance and positioned in the second rest/emptying/maintenance position. This makes it possible to minimize operations carried out manually and avoid access to workstations for maintenance of the guns located at height.

Preferably, in the paint booth according to the invention said second rest/emptying/maintenance position is located in proximity of said base surface, and more preferably said second rest/emptying/maintenance position is located under said base surface. In this way, the emptying/maintenance operations can be carried out in proximity of the base surface, according to methods better described below.

In a particularly preferred embodiment of the invention, the paint booth comprises second dispensing means for dispensing powder paint facing into said painting area from substantially opposite position with respect to said first dispensing means, said second dispensing means being operatively connected to second movement means and comprising a second plurality of guns aligned along a second vertical axis, said guns being spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position. In the way, with the first and second means for dispensing the powder paint positioned substantially opposite each other, preferably along blocks which extend vertically, optimal painting of the parts is ensured without requiring more or less complicated systems for the movement thereof, such as systems based on rotating supporting hooks.

According to an embodiment of the invention, the guns can be individually actuated by the corresponding movement means.

Alternatively, the first plurality of guns and/or the second plurality of guns can be collectively actuated by the corresponding first and/or second movement means. In this latter case, the said first and/or second movement means can comprise, for example, belt means or chain means connecting respectively said first plurality of guns and/or said second plurality of guns with first and/or second driving motors.

The first plurality of guns and/or said second plurality of guns can be respectively mounted on a first and/or second support translatory movable with respect to said supporting structure.

As a preferred alternative, said first plurality of guns and/or said second plurality of guns can be respectively mounted on a first and/or second support pivotally movable with respect to said supporting structure.

Advantageously in the paint booth according to the invention, said first dispensing means comprises a third plurality of guns aligned along a third vertical axis parallel to said first vertical axis. Similarly, the second dispensing means can comprise a fourth plurality of guns aligned along a fourth vertical axis parallel to said second vertical axis. In general, it is possible to have, for each of the dispensing means, a plurality of guns aligned along a plurality of corresponding vertical axis.

According to a particular embodiment of the paint booth according to the invention, at least one said guns of said first plurality of guns is kept in a fixed position while the guns of said second and/or third and/or fourth plurality of guns are moved with alternated motion along said second and/or third and/or fourth vertical axis. Such gun which is kept fixed during the painting operation is conveniently pivotally orientable in a vertical plane. In this way it is possible to dedicate one of the gun to the painting of a particular area of the products, normally not reachable with a horizontal straight orientation of the guns, by giving to said dedicated gun a particular orientation and keeping it fixed during painting,

In such a case, the remaining guns of the vertical plurality of guns to which said dedicated gun belongs, can be conveniently kept inactive and parked in proximity of said base surface. Further characteristics and advantages of the present invention will be more apparent from the description of preferred, but not exclusive, embodiments of a paint booth according to the invention, illustrated in the accompanying drawings, in which identical reference numerals denote identical elements, without intending to limit the scope of application in any way.

With reference to the accompanying figures, the paint booth according to the invention 1, 2 and 3, comprises a supporting structure 10, for example constituted by a supporting framework.

The booth 1, 2, and 3 also comprises a base surface 20, and one or more walls 31, 32, 33 and 34 that define a painting area 50. The walls 31, 32, 33 and 34 can totally enclose the painting area 50 or only o portion thereof. In a preferred embodiment of the invention, the walls 31, 32, 33 and 34 comprises a plurality of sheets positioned on all perimetral walls of the painting booth.

The booth 1, 2, and 3 further comprises first dispensing means 51 for dispensing powder paint facing into said painting area 50, said first dispensing means 51 being operatively connected to first movement means 511 for actuating both the painting operation and the movement of the dispensing means 51 from a first operating position to a second rest/emptying/maintenance position.

The products 60 to be treated enter the space 50 inside the booth, normally hanging from an overhead conveyor, and are subjected for the entire length thereof to the painting operation through the dispensing means 51. In general, the positioning of the dispensing means, as well as the path of the products inside the paint booth can be adapted according to the needs.

One of the peculiar characteristics of the booth 1, 2, and 3 according to the invention is given by the fact that said first dispensing means 51 comprises a first plurality of guns 510 aligned along a first vertical axis, said guns 510 being spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position.

In other words, said first 511 movement means are adapted to move said first 51 dispensing means to a first operating position and to position said first dispensing means in a second rest/emptying/maintenance position differing from said first operating position. Moreover, said first 511 movement means are adapted to relatively move said guns 510 with respect to each other, so as to be spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in said second rest/emptying/maintenance position.

Thus, with reference to figures 7a-7d, the first movement means 51 1 allow the movement in vertical direction of the guns 510 (spaced at a first distance) along a predetermined operating path, for example the up and down movement of the bold arrow of figure 7a. At the end of the operations, the guns 510 are withdrawn form the painting area (fig. 7b), grouped together and spaced at a second distance (fig. 7c) and then positioned in a second rest/emptying/maintenance position (fig. 7d).

Preferably, as shown in the attached figures, said second rest/emptying/maintenance position is located in proximity of said base surface 20, and more preferably said second rest/emptying/maintenance position is located under said base surface 20, for instance in correspondence of a dedicated suction valve.

Therefore, contrary to prior art booths, in which the maintenance and/or emptying and/or colour change operations are normally carried out in the operating position, in the booth according to the invention these operations are conducted in proximity of the base surface, thus reducing the times for the operation and eliminating the need for superstructures to enable operators to access the operating position of the paint dispensing means at height, especially when these are positioned at greater heights to those accessible to an operator standing on the ground.

As shown in figures 2 and 9-12, the paint booth 1, 2, and 3 according to the invention preferably comprises second dispensing means 52 for dispensing powder paint facing into said painting area 50 from substantially opposite position with respect to said first dispensing means 51. The said second dispensing means 52 are operatively connected to second movement means 521 and comprises a second plurality of guns 520 aligned along a second vertical axis. Also in this case, the guns 520 are spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position. In other words, according to such embodiment, said first and second means for dispensing the powder paint 51, 52 are each constituted by a plurality of powder paint guns 510 and 520 arranged superimposed and aligned vertically, on at least one row per side.

One of the peculiar characteristics of this embodiment is given by the fact that said means for dispensing the powder paint 51, 52 face the inside of said booth from substantially opposite positions. For the purposes of the present invention, the characteristic that said means for dispensing the powder paint 51, 52 face the inside of said booth from substantially opposite positions should be intended to refer to a situation in which said dispenser means emit powders in opposite directions along two substantially parallel axes. Preferably, the emission of powder by the opposite dispensing means takes place along a same axis so that the jets of powder "collide" at the part to be painted.

In practice, in the operating position, the guns are arranged along one or more vertical blocks that extend for the whole height of the part to be painted and are spaced from one another and moved in such a manner as to cover at least a portion of the length of the part to be painted. At the end of the operations, the movement means carry the guns in proximity of the base surface "lowering them" and superimposing them in proximity to one another. At this point it is possible to proceed, for example, with the operations to empty and clean them externally.

Said movement means can be activated by a single actuator, for example a motor, or can be provided with independent actuators, for each block or for each gun. In the embodiment of figures 3-7, the guns are individually actuated by the corresponding movement means.

Alternatively, according to preferred embodiments the guns can be collectively actuated by the corresponding movement means.

For example, with reference to figures 9-11, the first 511 and/or second 521 movement means can comprise belt means or chain means 550 connecting respectively said first plurality of guns 510 and/or said second plurality of guns 520 with first and/or second driving motors.

As shown in figure 8a-8d and 10 in the paint booth according to the invention said first plurality of guns 510 and/or said second plurality of guns 520 are respectively mounted on a first 71 and/or second 72 support translatory movable with respect to said supporting structure 10. In practice, the first and second movement means 511, 521 allow the movement in vertical direction of the guns 510, 520 (spaced at a first distance) along a predetermined operating path (for example the up and down movement of the bold arrow of figure 8a). At the end of the operations, the guns 510 and 520, mounted on the supports 71 and 72 are withdrawn form the painting area (fig. 8b and dotted part of figure 10), grouped together and spaced at a second distance (fig. 8c) and then positioned in a second rest/emptying/maintenance position (fig. 8d).

According to a preferred embodiment shown in figure 11, the first plurality of guns 510 and/or said second plurality of guns 520 are respectively mounted on a first 81 and/or second 82 support pivotally movable with respect to said supporting structure 10. In this case, the first and second movement means 511, 521 allow the movement in vertical direction of the guns 510, 520 (spaced at a first distance) along a predetermined operating path, as in figure 9. At the end of the operations, the guns 510 and 520, mounted on the supports 81 and 82 are withdrawn form the painting area and grouped together at a second distance as shown in figure 11, and then positioned in a second rest/emptying/maintenance position with the guns below the base surface (position not shown).

In any case, a typical colour change operation can therefore be carried out by withdrawing the guns from the booth and lowering them in proximity of the base surface of the booth. Emptying can be carried out in a specific suction collector or, preferably, in suction means arranged at the base surface, for example in suction means provided with openings controlled by means of suitable valves positioned under the base surface of the booth, by moving the guns forward into said valves. After emptying the guns are withdrawn from the valve, or in any case from the suction means, repositioned at height and moved forward in the booth.

With reference to figure 12, in an embodiment of the paint booth 3 according to the invention, said first dispensing means 51 comprises a third plurality of guns 530 aligned along a third vertical axis parallel to said first vertical axis. Similarly, said second dispensing means 52 can comprise a fourth plurality of guns 540 aligned along a fourth vertical axis parallel to said second vertical axis.

In other words, it is also possible to provide several vertical blocks of guns on the same side. In this case, the guns of one block can be arranged aligned relative to the guns of the adjacent block, as shown in figure 4, or staggered relative thereto, as shown in figures 5 and 6. In this latter case, a further horizontal translation movement of the guns of the two adjacent blocks can be provided, so that they are superimposed along a same vertical axis, to form a single block with double the number of guns relative to the original configuration.

In general, with reference to figure 13 a- 13b, the movement means are adapted to impart to said dispensing means a first movement of translation along a substantially vertical axis which is an up and down movement during operation (see double-headed arrows of figures 13a-13b) and to position the dispensing means in second rest/emptying/maintenance position (see figure 13 c).

With reference to figure 13 d, according to a particularly embodiment of the paint booth of the invention, at least one said guns 91 of said first plurality of guns 510 can be kept in a fixed position while the guns of said second 520 and/or third 530 and/or fourth 540 plurality of guns are moved with alternated motion along said second and/or third and/or fourth vertical axis. As already explained, the gun 91 which is kept fixed during the painting operation is conveniently pivotally orientable in a vertical plane. In this way it is possible to dedicate one of the gun to the painting of a particular area of the products, normally not reacheable with a horizontal straight orientation of the guns, by giving to said dedicated gun a particular orientation and keeping it fixed during painting. As shown in figure 13d, the remaining guns 910 belonging to the same vertical row are conveniently kept inactive and parked, for instance, in proximity of said base surface 20.

It has been seen how the paint booth according to the invention makes it possible to fully achieve the set aim and objects. Appropriate movement of the dispensing means allows optimal painting of the products even of considerable longitudinal dimensions, minimizing the times required for emptying and/or maintenance of these dispensing devices, reducing the space normally required by conventional booths and decreasing the time for passage of the parts in the booth.

Moreover, unlike booths of known type which required structures to enable access to the work station of the dispensing means at height when these cannot be reached by an operator standing on the ground, the booth according to the invention allows all maintenance, emptying and colour change operations to be carried out in proximity of the base surface. This enables a reduction in the mechanical complexity of the booth and a decrease in the installation and maintenance costs of the booth itself and of the plant associated therewith.

The booth according to the present invention may advantageously be used in painting plants for products. Painting plants for products, and in particular automated painting plants comprising one or more booths according to the description above, form a further aspect of the present invention.

On the basis of the foregoing description, other characteristics, modifications or improvements are possible and evident to the average person skilled in the art. These characteristics, modifications and improvements must therefore be considered part of the present invention. In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

Claims

A paint booth (1, 2, 3) for powder painting plants for products (60) characterized in that it comprises: a supporting structure (10), a base surface (20), one or more walls (31, 32, 33, 34) that define a painting area (50), first dispensing means (51) for dispensing powder paint facing into said painting area (50), said first dispensing means (51) being operatively connected to first movement means (511) and comprising a first plurality of guns (510) aligned along a first vertical axis, said guns (510) being spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position.

The paint booth (1, 2, 3) according to claim 1, characterized in that said second rest/emptying/maintenance position is located in proximity of said base surface (20). The paint booth (1, 2, 3) according to claim 1 or 2, characterized in that said second rest/emptying/maintenance position is located under said base surface (20).

The paint booth (1, 2, 3) according to one or more of the preceding claims, characterized in that it comprises second dispensing means (52) for dispensing powder paint facing into said painting area (50) from substantially opposite position with respect to said first dispensing means (51), said second dispensing means (52) being operatively connected to second movement means (521) and comprising a second plurality of guns (520) aligned along a second vertical axis, said guns (520) being spaced at a first distance when positioned in a first operating position and spaced at a second distance, less then said first distance, when positioned in a second rest/emptying/maintenance position.

The paint booth (1, 2, 3) according to one or more of the preceding claims, characterized in that said guns (510, 520) are individually actuated by the corresponding movement means.

The paint booth (1, 2, 3) according to one or more of claims 1 to 4, characterized in that said first plurality of guns (510) and/or said second plurality of guns (520) are collectively actuated by the corresponding first (511) and/or second (521) movement means.

The paint booth (1, 2, 3) according to claim 6, characterized in that said first (511) and/or second (521) movement means comprises belt means or chain means (550) connecting respectively said first plurality of guns (510) and/or said second plurality of guns (520) with first and/or second driving motors.

8. The paint booth (1, 2, 3) according to claim 6 or 7, characterized in that said first plurality of guns (510) and/or said second plurality of guns (520) are respectively mounted on a first (71) and/or second (72) support translatory movable with respect to said supporting structure (10).

9. The paint booth (1, 2, 3) according to claim 6 or 7, characterized in that said first plurality of guns (510) and/or said second plurality of guns (520) are respectively mounted on a first (81) and/or second (82) support pivotally movable with respect to said supporting structure (10).

10. The paint booth (1, 2, 3) according to one or more of the preceding claims, characterized in that said first dispensing means (51) comprises a third plurality of guns (530) aligned along a third vertical axis parallel to said first vertical axis.

11. The paint booth (1, 2, 3) according to one or more of the preceding claims, characterized in that said second dispensing means (52) comprises a fourth plurality of guns (540) aligned along a fourth vertical axis parallel to said second vertical axis.

12. The paint booth (1, 2, 3) according to one or more of the preceding claims, characterized in that at least one said guns (91) of said first plurality of guns (510) is kept in a fixed position while the guns of said second (520) and/or third (530) and/or fourth (540) plurality of guns are moved with alternated motion along said second and/or third and/or fourth vertical axis.

13. The paint booth (1, 2, 3) according to claim 12, characterized in that said at least one gun (91) is pivotally orientable in a vertical plane.

14. The paint booth (1, 2, 3) according to claim 12 or 13, characterized in that the remaining guns (910) of said first plurality of guns (510) are inactive and parked in proximity of said base surface (20).

15. Painting plant comprising a painting booth according to one or more of the previous claims.