FR3059917A1 - PAINT APPLICATOR COMPRISING ADJUSTABLE SKIRT AIR - Google Patents

Abstract

The invention relates to a bowl type paint applicator (2; 102; 202) comprising: - a main body (3), - at least one paint spraying cup (4) carried by the main body (3), and - At least one crown (14, 26) forming a skirt air distribution channel located in the main body (3) and able to diffuse air around the cup (4), the applicator comprises suitable means changing the direction of at least a portion of an air jet diffused around the cup (4).

Description

© Publication number: 3,059,917 (only to be used for reproduction orders) © National registration number: 16 62424 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY

COURBEVOIE © IntCI ⁸

B 05 B 1/26 (2017.01), B 05 B 3/10

A1 PATENT APPLICATION

©) Date of filing: 14.12.16. © Applicant (s): COMPAGNIE PLASTIC OMNIUM (30) Priority: Public limited company - FR. @ Inventor (s): HELMREICH MARC and VIDAL SOPHIE. (43) Date of public availability of the request: 15.06.18 Bulletin 18/24. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): COMPAGNIE PLASTIC OMNIUM related: Anonimous society. ©) Extension request (s): (© Agent (s): LLR.

? 4) PAINT APPLICATOR COMPRISING ADJUSTABLE SKIRT AIR.

FR 3 059 917 - A1 (tV) The invention relates to a bowl-type paint applicator (2; 102; 202) comprising:

- a main body (3),

- at least one cup (4) for spraying paint carried by the main body (3), and

- At least one crown (14, 26) forming a skirt air diffusion channel located in the main body (3) and capable of diffusing air around the cup (4), the applicator comprises suitable means modifying the direction of at least part of a jet of air diffused around the cup (4).

The invention relates to the field of paint applicators, more particularly of bowl type paint applicators.

Auto body parts are painted in booths designed for this purpose. Generally, the painting process consists of the successive application of three different coatings on the part. A first coating, called primary, has the function of promoting the grip on the part of the second coating. A second coating, called base, has the function of giving color to the room. Finally, a third coating, called varnish, has a function of holding and protecting the base. The parts to be painted circulate in the painting booth in front of different painting stations, such as for example “paint robots”, to receive the primer, then the base and finally the varnish. They can also be fixed spraying stations, the part being moved in front of the sprayer.

In the following description, the term paint corresponds to at least one of these three coatings.

The bodywork parts have portions having more or less wide surfaces. For example, a bumper may have solid portions for which the surface to be painted is therefore large, and grids for which the surface to be painted is relatively small.

In order not to waste paint, it is necessary to set up a device and / or a process allowing to obtain a good coefficient of transfer of paint on the part. The transfer coefficient corresponds to the amount of paint deposited on the part compared to the amount of paint sprayed from a sprayer. In other words, you have to make sure to deposit the maximum amount of spray paint on the part.

A current solution consists in equipping the paint booth with several sprayers, often two in number per coating layer (primer, base and varnish). These can be sprayers mounted on robotic and articulated arms, arms programmed to follow a precise trajectory at a given speed depending on the parts and areas to be painted. They can also be sprayers mounted on a fixed spraying station, the part being moved in front of the sprayer.

These sprayers include a bowl-shaped applicator at their end. Each bowl has a paint spray cup at its free end. The cup is rotated and paint is injected in the center of the latter. The paint is applied to the wall of the cup due to centrifugal force and is split into droplets thanks to the shape of the cup and its rotation. The droplets are then projected to the part to be painted from the cup. The paint spray is focused by air jets projected around the cup. These air jets take the form of a skirt surrounding the cup and are called "skirt airs". These air jets are sprayed from the end of the applicator all around the cup to conform the paint spray and atomize the paint.

An applicator generally includes one or two airs of skirts. In the case of double skirt airs, the two air jets are concentric, the internal air jet allowing the creation of a vortex for the sprayed paint and the external air jet focusing the paint spray. The external air jet delimits the impact area of the paint spray on the part to be painted. The direction of propagation of the air jets is invariant. Each cup works with one or more specific skirt tunes adapted to the diameter of the cup.

Each sprayer includes a cup of different diameter and is intended to paint different surfaces. Large surfaces are painted by a sprayer equipped with a large diameter cup having a high flow rate and a large impact diameter and thinner surfaces are painted by a sprayer equipped with a small diameter cup having a relatively low flow rate and a small impact diameter to limit paint loss.

However, and taking into account the industrial rates to be respected, a part cannot stay too long in front of a sprayer. In order to be able to respect these rates, it is frequent that an area is painted by a sprayer not suitable for this area. This is the case in areas of small areas painted by a sprayer equipped with a large diameter cup and for which the skirt airs are of large diameter. This practice results in a low transfer coefficient, reflecting a significant loss of paint. Sometimes, a part must be painted by a single robot while it has surfaces of various sizes which also leads to a significant loss of paint.

Another existing solution consists in loading the paint at the outlet of the bowl so that it is attracted by the part to be painted connected to ground and whose surface has previously been made conductive. However, this paint / part attraction only occurs when the paint is very close to the part, i.e. a few millimeters. This is not a satisfactory solution in terms of improving the transfer coefficient.

An object of the invention is to eliminate, or at least significantly limit, all or part of the aforementioned drawbacks, by proposing a painting device making it possible to obtain a large transfer coefficient while maintaining an optimum paint rate.

To this end, the subject of the invention is a bowl-type paint applicator, comprising:

- a main body,

- at least one paint spray cup carried by the main body, and

- At least one ring forming a skirt air diffusion channel located in the main body and capable of diffusing air around the cup, the applicator comprising means capable of modifying the direction of at least part d '' a jet of air diffused around the cup.

Thus, a sprayer, for example a robotic arm or a stationary spraying station, equipped with such an applicator will be able, during the time during which a part is in front of it, to modify the shape and / or the size of the air jet. diffused around the cup and consequently the shape and / or size of the area of impact of the paint on the part to be painted, area delimited by the air jet. For example, it is possible to paint a first part of a body part comprising a large surface with the air jet oriented so as to have a first wide impact zone and then to paint a second part of the body part. having a finer surface with the air jet oriented so as to have a second finer impact zone than the first. The impact area of the paint is thus adapted to the surface of the part located in front of the applicator, which allows the transfer coefficient to be increased by preventing a large amount of paint from being sprayed on both sides. other from the area being painted. In other words, the spectrum of action of a cup is greatly increased, that is to say the number of zones of a bodywork part which can be painted by the cup with a satisfactory transfer coefficient. This also avoids having to replace the cup on the applicator by the intervention of an operator.

As the air crown can vary in terms of size, it is possible to use cups of different diameters with the same applicator by adapting the skirt tunes to the mounted cup, which allows standardization of the paint applicator.

In addition, it is possible to reduce the number of sprayers on a paint line because the same sprayer can paint areas of different surfaces.

It is also possible to increase the painting rates thanks to a programming of the painting process adapted to the part to be painted. For example, it is possible to paint a branch of a bumper with an applicator whose air jet is no longer round but oval in order to quickly paint the branch while maintaining a high transfer coefficient. The paint rate is the same as in the prior art but the paint rate is improved because the surfaces are painted more quickly.

Finally, the final appearance of a bodywork part can be improved because the adaptation of the impact zone makes it possible to spray the right amount of paint with the expected appearance of the painted bodywork. For example, in the case of a metallic or pearly paint, adapting the size and / or the shape of the diffused air jet and therefore of the zone of impact of the paint on the part allows a better distribution of the glitter or the mother-of-pearl on the bodywork part.

The applicator according to the invention can optionally include one or more of the following characteristics:

the crown forming a skirt air diffusion channel comprises one end in contact with a set of air outlet orifices, the end being able to be controlled by the means capable of modifying the direction of the air jet diffused around the cup;

the end in contact with the set of air outlet orifices (8) comprises several zones independent of one another, each zone comprising means capable of modifying the direction of an air jet diffused by the corresponding area;

- the number of zones is 4 identical zones;

- the areas of the end in contact with the set of air outlet openings opposite one another are capable of being piloted at the same time;

- The means capable of modifying the direction of the diffused air jet comprise at least one pneumatic valve;

- the applicator comprises two crowns forming air channels for concentric skirt air circulation;

- an internal crown is fixed and an external crown is able to be driven.

- The applicator comprises several cups of different diameters nested one inside the other concentrically, and;

- the skirt airs are negatively charged.

According to the invention, a paint spraying device is also provided, preferably a robotic arm, comprising an applicator according to the invention.

There is also provided according to the invention a method of spraying paint using an applicator according to the invention.

Preferably, a first surface is painted with the crown forming a skirt air diffusion channel oriented in a first direction, then a second surface is painted with a shape different from the first surface with the crown forming an air diffusion channel of skirt of which at least a part is oriented in a second direction different from the first direction.

We will now present embodiments of the invention with the support of the appended figures, which are provided by way of examples and have no limiting character, in which:

- Figure 1 is a front view of the upper surface of a paint applicator according to the invention;

- Figure 2 is a schematic representation of a comparison between the direction or directions of an air jet from an applicator according to the invention and according to the prior art;

- Figs 3 and 4 are sectional views of an applicator according to the invention;

- Figure 5 is a front view of the upper surface of the applicator according to a second embodiment;

- Figure 6 is a front view of the upper surface of the applicator according to a third embodiment;

- Figure 7 is a perspective view of a step in a method of painting a body part according to the prior art; and

- Figures 8 to 10 are perspective views of steps in the painting process of bodywork parts using an applicator according to the invention.

Referring now to FIG. 1 which shows an example of a paint applicator 2 of the bowl type, comprising a main body 3 and a cup 4 for spraying paint mounted on the main body 3. This cup 4 is mounted in the center of an upper face 6 of the applicator 2. The upper face 6 comprises a plurality of air outlet orifices 8 forming two sets of orifices of annular and concentric shape surrounding the cup, an internal set 10 of orifices 8 and an external assembly 12 of orifices 8. These two assemblies allow the diffusion of two concentric air jets around the cup 4. Each orifice assembly is supplied with air by a crown forming an air diffusion channel (not represented in FIG. 1) located under the upper face 6 of the applicator 2. The term “crown” means a hollow ring forming an air diffusion channel up to the air outlet orifices 8 in order to form a jet skirt-shaped air around the cup 4. Each crown is independent of the other. The air rising through the crowns feeds respectively the internal assembly 10 of orifices 8 and the external assembly 12 of orifices 8.

The internal assembly 10 of orifices 8 is supplied by a fixed ring which generates a jet of air at the outlet of the internal assembly 10 of orifices 8 always extending in the same direction. This air jet allows the creation of a vortex for the sprayed paint from the cup 4.

The external assembly 12 of orifices 8 is in turn supplied by a crown comprising means capable of modifying the direction of at least part of the crown supplying the external assembly 12 of orifices 8, more precisely the end of the crown in contact with the external assembly 12 of orifices 8 as will be illustrated later, in order to modify the size and / or the shape of the air jet diffused from the external assembly 12 of orifices 8 Since the air flow diffused from the external assembly 12 makes it possible to focus the paint spray, the impact zone on the part is delimited by it. It is therefore possible to modify the shape and / or the size of the impact zone on the part to be painted as a function of the shape and / or the size of the air jet diffused from the external assembly 12 d '' holes 8.

The number of sets of annular orifices can vary, it is for example possible to have only one ring of air outlet orifices 8. In this case, the jet of air diffused from this ring can be piloted like the external assembly 12 of orifices 8 of FIG. 1. In the case of two rings, it is possible that the two air jets are piloted.

As illustrated in Figure 2, we can see the advantage of the possibility of modifying the size of the air jet.

The lower part of the diagram represents an applicator 2 ’of the prior art comprising a set 22 of orifices from which an air jet 24 is generated. This air jet 24 is always diffused in the same direction. A 24 ’paint spray focused by the air jet 24 therefore always has the same diameter.

The upper part of the diagram represents an applicator 2 according to the invention in which only the external assembly 12 of orifices 8 is shown. The end 38 of the crown 14 supplying the external assembly 12 of orifices 8 can be controlled in order to modify the diameter of the air jet leaving the external assembly 12 of orifices 8. In the example of the figure 2, the end 38 can take three different positions making it possible to generate three air jets 16, 18 and 20 oriented in three different directions in order to generate three skirt airs of different diameters and therefore three paint impact surfaces on the part to be painted with different diameters. Figure 2 shows three paint sprays 16 ', 18' and 20 'of different widths corresponding to the air jets 16, 18 and 20 respectively.

Figures 3 and 4 show the applicator 2 of Figure 1 in two different configurations. The applicator 2 comprises, in addition to the cup 4 and the sets of orifices 10 and 12, two rings 26 and 14 supplying the sets 10 and 12 of orifices 8 respectively with air. These are the crowns mentioned above and not shown in FIG. 1, the crown 14 being shown in FIG. 2.

The crown 26, the internal crown, comprises an innermost proximal portion 30 of the applicator 2 and a distal end 32 in contact with the air outlet orifices 8 of the internal assembly 10 of orifices 8. The air blown in from the crown 26 propagates in the form of a skirt around the cup 4 in a main direction 34.

The crown 14, external crown, has an architecture similar to that of the crown 26 with a proximal portion 36 and a distal end 38. The air blown in from the crown 14 propagates in the form of a skirt around the cup 4 according to a main branch 40.

The crown 14 comprises means (not shown) capable of modifying the direction of at least part of a jet of air diffused around the cup by modifying the direction of at least part of the end 38 of the crown 14. It may for example be a pneumatic valve or any other known means allowing such control.

In the case of a pneumatic valve, the latter will be more or less activated (i.e. open) by an air jet having a flow spectrum which can range, for example, from 100 to 600 nL per minute. It is possible to envisage, for example, that the valve includes three activation thresholds at 200, 400 and 600 nL / min. Each threshold corresponds to a more or less significant opening of the valve. The air rushing into the end 38 then exerts a greater or lesser constraint (depending on the air flow) on the latter which leads to a change of direction of the end 38. We see in the figure 4 that the end 38 extends in a direction different from that of FIG. 3. This leads to the generation of an air jet extending from the external assembly 12 of orifices 8 in a direction main 42 different from the main direction 40 of FIG. 3.

In the example illustrated above, there are three stages of flow leading to three different positions of the end 38. Of course, the spectrum of flow can vary just like the number of stages and consequently the number of positions which can be taken by the end 38.

As described above, it is possible to modify the direction of at least part of the crown supplying the external assembly 12 of orifices 8, more precisely the end 38 of the crown 14 in contact with the external assembly 12 d '' holes 8.

It is for example possible to control the assembly of the end 38 of the crown 14 supplying the external assembly 12 of orifices 8 in order to increase or reduce the diameter of the generated air skirt which, due to of the annular shape of the external assembly 12 of orifices 8, a circular shape. Therefore, there is a variation in the diameter of the paint impact area on the workpiece.

It is also possible to vary only part of the end 38 of the crown 14 supplying the external assembly 12 of orifices 8 in order to vary the shape of the air skirt and thus the shape of the zone impact on the part to be painted. This allows you to adapt the shape of the paint impact zone to the shape of the painted part area. For example, it is possible to modify the shape of the impact zone from circular to oval to paint a part of a body part having an elongated shape as will be explained later.

FIGS. 5 and 6 respectively represent applicators 102 and 202 according to second and third embodiments. In these figures, elements similar to those of the previous figures are designated by identical reference numerals. Modified or new elements will be numbered in steps of one hundred, each hundred corresponding to an embodiment.

In FIG. 5, the external assembly 12 of orifices 8 is divided into two zones 144 and 146. The crown supplying the external assembly 12 of orifices 8 is then divided into two parts, each part being able to be controlled independently in order to modify the direction of the end of the crown situated under zone 144 or under zone 146. It may for example be a pneumatic valve for each of the parts of the crown with an operating mode similar to that explained before.

It is thus possible to independently modify the two zones 144 and 146, which makes it possible to modify the shape in addition to the diameter.

In FIG. 6, the number of zones is equal to 4 identical zones 248, 250, 252 and 254. The operation is the same as with the two zones 144 and 146, namely independent control of each of the four parts of the crown located under the external assembly 12 of orifices 8 at the zones 248, 250, 252 and 254. This increases the number of shapes that can be taken up by the skirt airs.

Advantageously, the opposite zones 248/252 and 250/254 are controlled at the same time. This allows the air jet to be "pinched" (by changing the orientation of the parts of the crown located under these areas) in order to make it take an oval shape adapted to the areas of the parts to be painted comprising a narrow and elongated surface.

Obviously, the number of zones can be different, it can be zones of identical or different size. It is also conceivable that each air outlet orifice 8 is controlled independently of the others. In addition, the division into zones does not exclude the possibility of controlling all the zones at the same time and in the same way in order to vary only the diameter of the air flow.

Figures 7 to 10 show perspective views of stages of a painting process using an applicator according to the prior art (Figure 7) and according to the invention (Figures 8 to 10).

In the prior art, illustrated in FIG. 7, the bodywork part 54 is painted by a sprayer 55 fitted with an applicator comprising a cup spraying paint focused by non-adjustable skirt airs. It is observed that, for all the zones of the part and this whatever their shape, the paint spray is identical which leads to a relatively low transfer coefficient because a majority of the sprayed paint passes through the Exhibit 54 without depositing on it.

In FIG. 8, it can be seen that the part 58, in particular a zone 60 of the part 58, is painted by a sprayer 56 equipped with an applicator which can vary the shape and / or the size of the air jet 59 projected from the applicator. It is more precisely the applicator of FIG. 6 which can "pinch" the air flow in order to obtain an ovoid shape.

The transfer coefficient is only improved.

Figures 9 and 10 and illustrate the operation of the sprayer 56 equipped with an applicator according to the invention depending on the area of the bodywork part 54 to be painted.

In FIG. 9, the sprayer 56 paints an area 62 of the part 54, an area having a narrow and elongated surface. In order to deposit the maximum amount of sprayed paint, the shape of the air jet 61 focusing the paint spray is modified in order to obtain an elongated shape. The area of impact of the paint on the part is then elongated and narrow, in line with the shape of the area to be painted. The transfer coefficient is improved and area 62 is painted more quickly.

When the sprayer 56 paints another zone, for example the zone 64 illustrated in FIG. 10, the shape of the air jet 61 focusing the paint spray is then modified in order to ensure that the impact zone of the paint on the part is in line with the shape of the area of the part to be painted. Here, half of the crown supplying a set of air openings is redirected to give a semicircular shape to the air flow.

The invention is not limited to the embodiments presented and other embodiments will be apparent to those skilled in the art.

It is in particular possible to vary the number of cups. It is for example possible to have several cups of different diameters nested one inside the other in a concentric manner, each of the cups receiving paint in turn or several cups receiving paint at the same time. The combination between the cups of different diameters and the possibility of varying the size and / or the shape of the air flow (s) surrounding them according to the cup activated further increases the spectrum of action of the applicator while retaining a high paint rate and a high transfer coefficient.

It is also possible to charge the skirt airs negatively. Since the paint is also negatively charged at the outlet from the cup or cups, the interaction between the air and the paint makes it possible to better focus the paint spray.

Nomenclature

2, 102, 202: applicator

2 ’: applicator according to the prior art: main body: cup: upper surface: air outlet openings: internal set of openings: external set of openings

12 ': set of orifices according to the prior art: external crown: ^1st air jet

16 ': ^1st paint spray: ^2nd air jet

18 ': ^2nd paint spray: ^3rd air jet

20 ': ^3rd paint spray jet air according to the prior art

24 ': paint spray according to the prior art: internal crown: proximal portion of the crown 26: distal end of the crown 26: direction of the air jet from the internal assembly 10 of orifices 8 36: portion proximal of the crown 14 38: distal end of the ring 14: 1 ^st direction of air jet from the outer assembly 12 of orifices 8 42: 2 ^nd direction of air jet from the set 12 external ports 8: 1 piece painting ^era: sprayer according to the prior art sprayer according to the invention: ^2nd piece to paint: spray sprayer according to the invention: 1 area to be painted ^{era: 2nd} zone paint: ^3rd painting area

144: 1 external ^era set area 12 into two zones

146: ^2nd region of the outer assembly 12 into two zones 258: 1 ^st area of the outer assembly 12 into four zones 250: ^2nd region of the outer assembly 12 into four zones 252: ^3rd zone of the external set 12 in four zones

254: 4 ^th zone of the external assembly 12 in four zones

Claims (13)

Claims 1. Bowl type paint applicator (2; 102; 202), comprising: - a main body (3), - at least one cup (4) for spraying paint carried by the main body (3), and - At least one crown (14, 26) forming a skirt air diffusion channel located in the main body (3) and capable of diffusing air around the cup (4), characterized in that it comprises means capable of modifying the direction of at least part of a jet of air diffused around the cup (4). 2. Applicator (2; 102; 202) according to claim 1, in which the crown (14) forming a skirt air diffusion channel comprises one end (38) in contact with a set of air outlet orifices. (8), the end (38) being able to be controlled by the means able to modify the direction of the air jet diffused around the cup (4). 3. Applicator (2; 102; 202) according to any one of the preceding claims, in which the end (38) in contact with the assembly (12) of air outlet orifices (8) comprises several zones (144, 146; 248, 250, 252, 254) independent of each other, each zone (144, 146; 248, 250, 252, 254) comprising means capable of modifying the direction of a jet of diffused air by the corresponding zone (144, 146; 248, 250, 252, 254). 4. Applicator (2; 102; 202) according to any one of the preceding claims, in which the number of zones (248, 250, 252, 254) is 4 identical zones. 5. Applicator (2; 102; 202) according to claim 4, in which the zones (248, 252; 250, 254) from the end in contact with the set of air outlet openings (8) opposite one another are capable of being piloted at the same time. 6. Applicator (2; 102; 202) according to any one of the preceding claims, in which the means capable of modifying the direction of the diffused air jet comprise at least one pneumatic valve. 7. Applicator (2; 102; 202) according to any one of the preceding claims comprising two crowns (14, 26) forming air channels for concentric skirt air circulation. 8. Applicator (2; 102; 202) according to claim 7, in which an internal ring (26) is fixed and an external ring (14) is capable of being driven. 9. Applicator (2; 102; 202) according to any one of the preceding claims comprising several cups of different diameters nested one inside the other concentrically. 10. Applicator (2; 102; 202) according to any one of the preceding claims, in which the skirt airs are negatively charged. 11. Paint spraying device, preferably a robotic arm, comprising an applicator (2; 102; 202) according to any one of claims 5 previous. 12. A method of spraying paint using an applicator (2; 102; 202) according to any one of the preceding claims. 13. The spraying method as claimed in claim 12, in which a first surface (62) is painted with the crown (14) forming an air diffusion channel of 10 skirt oriented in a first direction, then a second surface (64) of different shape from the first surface (62) is painted with the crown (14) forming a skirt air diffusion channel, at least part of which is oriented according to a second direction different from the first direction. 1/5 12 '