Sprayer comprising an air supply skirt and method of mounting such a skirt on a main body of such a sprayer

Abstract

Sprayer comprising an air supply skirt and method of mounting such a skirt on a main body of such a sprayer. The present invention relates to a coating product sprayer (2) comprising a main body (4), an air supply skirt (6) attached to the main body, and a magnetic attraction means (112) between the magnetic body and the air supply skirt. The sprayer includes a magneto-pneumatic or magneto-hydraulic system (100) which includes a magnetic device (100A) for attaching the air supply skirt (6) to the main body (4) and a pneumatic or hydraulic mechanism (100B) for locking and clamping the air supply skirt to the main body. Figure for the abstract: Figure 2

Description

Title of the invention: Sprayer comprising an air supply skirt and method of mounting such a skirt on a main body of such a sprayer

[0001] The present invention relates to a coating product sprayer equipped with an air supply skirt that distributes, near a spraying element of the sprayer, a flow of air to guide or shape a cloud of coating product droplets leaving the spraying element. This spraying element may be a rotating bowl or a magnetic spray head.

[0002] It is known to mount an air inlet skirt onto the main body of a sprayer by screwing it on. This technique requires that screw notches be made on the outside of the air inlet skirt so that a tool can apply tightening or loosening torque. These notches are potential accumulation zones for coating product, which leads to a risk of soiling the sprayer or coated surfaces. In addition, tightening the skirt onto the sprayer body is relatively slow and requires a tool, such as a torque wrench, to verify that the tightening torque applied is sufficient to ensure an airtight seal between the air inlet skirt and the rest of the sprayer. Finally, screwing must most often be done manually, to the point that automating the air inlet skirt replacement process proves, in practice, very complex.

[0003] Part of these problems is solved by the sprayer described in EP3222360A1, which discloses a coating product sprayer equipped with a magnetic attraction means between an air inlet skirt and a fixed component. This solution is generally satisfactory. However, the forces required to seal the air inlet skirt assembly on the sprayer body are significant, particularly for compressing seals located at the interface between the air inlet skirt and the main sprayer body. Consequently, large magnets must be used, and the forces exerted are intense, and therefore potentially dangerous, especially if a user's finger or a tool carried by the user becomes trapped. Furthermore, the intensity of the magnetic forces is such that, in practice, specific tools must be used to remove the air inlet skirt during maintenance.

[0004] It is these drawbacks that the invention intends to remedy more particularly by proposing a new coating product sprayer in which the mounting of an air supply skirt on a main body is facilitated and made safe for the operator, this mounting being able, to a large extent, to be automated.

[0005] To this end, the invention relates to a coating product sprayer comprising a main body, an air supply skirt attached to the main body, and a magnetic attraction means between the magnetic body and the air supply skirt, characterized in that the sprayer comprises a magneto-pneumatic or magneto-hydraulic system which includes

[0006] - a magnetic device for attaching the air supply skirt to the body principal; and

[0007] - a pneumatic or hydraulic mechanism for locking and tightening the skirt air supply to the main body.

[0008] Thanks to the invention, the magneto-pneumatic or magneto-hydraulic system of the sprayer allows, firstly, a magnetic force to engage the air supply skirt on the main body and then, secondly, a mechanical force to clamp the air supply skirt onto the main body. This allows, in particular, the compression of seals located between the skirt and the main body. This two-stage operation ensures that the magnetic force exerted by the magnetic device is relatively low, making it less dangerous for a user handling the air supply skirt during its assembly onto the main body. The fact that this magnetic force is relatively low facilitates the removal of the air supply skirt from the main body.Furthermore, this relatively low magnetic force and the automatable nature of the magneto-pneumatic or magneto-hydraulic system make the sprayer compatible with a method of mounting or dismounting the air supply skirt on the main body of the sprayer using a robot.

[0009] According to advantageous but not mandatory aspects of the invention, such a sprayer may incorporate one or more of the following features taken in any technically permissible combination:

[0010] - The magnetic attachment device is configured to exert pressure between the skirt air supply skirt and main body, an axial magnetic force, parallel to a longitudinal axis of the sprayer, with a first intensity, the pneumatic or hydraulic clamping mechanism is configured to exert between the air supply skirt and the main body an axial mechanical force, parallel to the longitudinal axis of the sprayer, with a second intensity and the second intensity is strictly greater than the first intensity.

[0011] - The sprayer includes sealing gaskets arranged between the inlet skirt air and the main body and the seals compressed by the mechanical force exerted by the pneumatic or hydraulic clamping mechanism isolate the conforming air circulation ducts from the outside of the sprayer.

[0012] - The air supply skirt includes a sleeve made of a ferroma material genetic, centered on a longitudinal axis of the sprayer in the mounted configuration of the air supply skirt on the main body and provided with at least one external relief for cooperation with the pneumatic or hydraulic clamping mechanism.

[0013] - The magnetic attachment device comprises a permanent magnet mounted on a support, movable parallel to the longitudinal axis of the sprayer and the permanent magnet or the support is configured to receive in support one end of the sleeve opposite a skirt body.

[0014] - The pneumatic or hydraulic clamping mechanism includes a movable piston parallel to the longitudinal axis of the sprayer, inside a chamber selectively supplied with pressurized fluid, and the piston is equipped with engagement devices with the external relief of the sleeve.

[0015] - The engagement elements are balls, the piston comprises surfaces of cams inclined relative to the longitudinal axis of the sprayer and, when the air supply skirt is hooked onto the main body by the magnetic hooking device and when the piston is moved towards an end of the sleeve opposite a body of the air supply skirt, the cam surfaces exert on the balls an engagement force in the external relief of the sleeve, this force being centripetal relative to the longitudinal axis.

[0016] - The sprayer includes at least one elastic element for returning the piston to a position in which the engagement elements are clear of the external relief of the sleeve.

[0017] - The sprayer includes a tool for dismantling the air supply skirt, this dismantling tool comprising gripping reliefs on the air supply skirt and configured to exert on the air supply skirt a force parallel to a longitudinal axis of the sprayer and opposite to a magnetic force exerted on the air supply skirt by the magnetic gripping device.

[0018] According to a second aspect, the invention relates to a method for mounting an air supply skirt on a main body of a coating product sprayer as mentioned above, characterized in that it comprises at least successive steps consisting of:

[0019] a) insert a sleeve of the air supply skirt into a central housing of the main body until the magnetic latching device exerts a magnetic latching force on the air supply skirt against the main body; and

[0020] b) supply the pneumatic or hydraulic clamping mechanism with pressurized fluid until the pneumatic or hydraulic clamping mechanism exerts a mechanical clamping force on the air supply skirt on the main body.

[0021] Advantageously, in step b), the sprayer's piston moves the balls towards the bottom of the central housing, carrying the sleeve with the balls along with it. engaged in the external relief.

[0022] The invention will become clearer upon reading the following description, given solely by way of non-limiting example and with reference to the accompanying drawings in which: - [Fig.1] The [Fig.1] is a partially exploded longitudinal section of a sprayer according to a first embodiment of the invention; - [Fig.2] Fig.2 is an exploded perspective longitudinal section of a magneto-pneumatic system belonging to the sprayer of the [Fig.l]; - [Fig. 3] [Fig. 3] represents, on two insets A) and B), the sprayer of the [Fig.l] during a first step of mounting an air supply skirt on a main body, insert B) being a larger scale view of detail B on insert A); - [Fig. 4] [Fig. 4] is a view analogous to [Fig. 3], during a second stage of the assembly process; - [Fig. 5] [Fig. 5] is a view analogous to [Fig. 3], during a third stage of the assembly process; - [Fig. 6] [Fig. 6] is a view analogous to [Fig. 3], during a fourth step in the assembly process; - [Fig. 7] Fig. 7 is a perspective view of the sprayer in its assembled state of the skirt on the main body, as well as a tool for dismantling the skirt; - [Fig.8] Fig.8 is an axial perspective section of the sprayer previous figures, during the dismantling of the skirt; - [Fig.9] Fig.9 is a cross-section analogous to Fig.1, for a sprayer in accordance with a second embodiment of the invention; and - [Fig. 10] [Fig. 10] is a view analogous to [Fig. 1], for a sprayer conforming to a third embodiment of the invention.

[0023] The coating product sprayer 2 shown in figures 1 to 8 comprises a main body 4 formed by the assembly of an external part 42, an internal part 44 and a base 46.

[0024] For example, the coating product is a liquid paint, primer or varnish intended to be applied to a body or component of a motor vehicle.

[0025] Screws 48 secure the parts 42, 44 and 46 of the main body. These screws 48 protrude from a front face 428 of the external part 42.

[0026] The sprayer 2 is of the internally charged electrostatic type and includes a high-voltage unit not shown, configured to bring to a given electrical potential the coating product sprayed by the sprayer 2.

[0027] A2 is a longitudinal axis of the sprayer 2.

[0028] A front side of the sprayer 2 or a component of this sprayer is defined as one side facing a part to be coated, during the use of the sprayer 2, and a rear side as a side facing away from the front side. In the figures, the front of the sprayer 2 is facing upwards and the rear is facing downwards.

[0029] An air supply skirt 6 is mounted on the main body 4 in the assembled configuration of the sprayer 2. This air supply skirt 6 comprises a skirt body 62 and a sleeve 64 screwed onto the skirt body 62.

[0030] Alternatively, the skirt body 62 and the sleeve are joined by crimping, welding and / or gluing.

[0031] The joining between the skirt body 62 and the sleeve 64 takes place at the level of a front end 641 of the sleeve.

[0032] The sleeve 64 is made of a ferromagnetic material, for example steel.

[0033] A spray bowl 8 also belongs to the sprayer 2 and is intended to be driven in rotation, around the longitudinal axis A2, by a turbine whose rotor 10 is noted as 10. The stator of the turbine is constituted by the internal part 44 of the main body 4 and carries a tip 12 equipped with a permanent magnet 14, of annular shape.

[0034] In the mounted configuration of the bowl 8 on the turbine rotor 10, an annular surface 82 of the bowl 8, which is made of a ferromagnetic material, comes into contact with the permanent magnet 14, which has the effect of creating a magnetic bearing between the bowl 8 and the magnet 14, when an airflow is directed between the magnet 22 and the annular surface 82.

[0035] Alternatively, only a part of the bowl 8 which defines the annular surface 82 is made of ferromagnetic material.

[0036] The sprayer 2 also includes a coating product injector 16 whose downstream end 162 penetrates a central bore 84 of the bowl 8, in a configuration mounted on the turbine rotor 10.

[0037] A hood 18 is mounted around the main body 4 and protects it against splashes of coating product.

[0038] The skirt body 62 is equipped with several channels 622 that pass through it from one side to the other, in a direction parallel to the longitudinal axis A2 in the mounted configuration of the air supply skirt 6 on the main body 4, and which each feed an outlet 624 through which jets of air can be directed towards a cloud of coating product leaving an edge 86 of the bowl 8, in order to shape this jet of coating product and / or direct it towards an object to be coated. The outlets 624 are provided on a circular front face 626 of the skirt body 62.

[0039] The skirt body 62 defines a recessed housing 628 in which a front portion of the external part 42 of the main body 4 is received in the mounted configuration of the air supply skirt 6 on the main body 4. The recessed housing 628 is provided on the rear of the skirt body 62.

[0040] The external part 42 of the main body 40 includes air supply ducts 422 to the air supply skirt 6. These channels 422 are supplied with air by channels 442 which extend essentially in a different plane from that of figures 1 and 3 to 6 and of which only the downstream ends are visible in these figures.

[0041] The bottom 628a of the recessed housing 628 is equipped with two annular grooves 628c and 628d which serve as distributors to supply two groups of conduits 622 from the outlets 424 of the conduits 422. To ensure airtightness between the conduits 422 and the grooves 628c and 628d, O-rings 20 are arranged in annular grooves 426 formed on the front face 428 of the external part 42 of the main body 4, i.e. in an interface zone between the main body 4 and the skirt 6. These O-rings 20 are intended to bear against the bottom 628a of the recessed housing 628 and to be compressed.

[0042] In the example shown in the figures, the O-rings 20 and the annular grooves 426 are concentric and there are three of them. In the variant not shown, the number and / or shape of the O-rings 20 and the annular grooves 426 are different.

[0043] The sleeve 64 is intended to be engaged in a central housing L2 of the sprayer 2 which is defined, radially to the longitudinal axis A2, between the external part 42 and the internal part 44 of the main body 4.

[0044] The rear edge of the sleeve 64 is denoted 642, that is, the edge of this sleeve opposite the skirt body 62. The end of the sleeve 64 that is closest to the rear edge 642 is denoted 644. The rear edge 642 delimits the rear end 644 opposite the skirt body 62. The rear end 644 is opposite the front end 641 of the sleeve 64.

[0045] S64 denotes the external radial surface of the sleeve 64. This external radial surface is provided with a peripheral groove 646 which forms a recessed housing on the outside of the sleeve 64. 646a denotes the rear edge of the peripheral groove 646, that is to say the edge of this groove closest to the end 644 of the sleeve 64.

[0046] We note 647 an external peripheral rib of the sleeve 64 which separates the peripheral groove 646 from the end 644. We note 647a the rear edge of this rib, that is to say the edge of this rib closest to the end 644 of the sleeve 64.

[0047] A magneto-pneumatic system 100 is provided in the central housing L2 to ensure that the skirt 6 is attached to the main body 4, and that this skirt is clamped to this main body. The magneto-pneumatic system 100 comprises a magnetic attachment device 100A and a pneumatic clamping mechanism 100B for the air supply skirt 6 on the main body 4.

[0048] The attachment, achieved by means of the magnetic attachment device 100A, ensures that the air supply skirt 6 remains in position on the main body 4, including when the latter is moved by a multi-axis robot or a reciprocator on the sprayer is mounted on. The sprayer's movements induce accelerations on the air supply skirt 6, which could cause the sleeve 64 to be forced out of the central housing L2. The magnetic attachment force is designed to withstand these accelerations.

[0049] The clamping force makes it possible to finalize the positioning of the air supply skirt 6 on the main body 4 and to compress the O-rings 20, thus ensuring the sealing of the supply circuit of the outlet ports 624 in conforming air of the cloud of coating product.

[0050] The magneto-pneumatic system 100 extends along a longitudinal axis A100 which coincides with the longitudinal axis A2 of the sprayer 2 in the mounted configuration of the magneto-pneumatic system 100 in the sprayer 2.

[0051] The magneto-pneumatic system 100 comprises a cap 102 immobilized on the main body 4 by screws which pass through one or more lugs 102a provided on the outside of the cap 102. One of these screws is represented by its center line 103 in [Fig.2],

[0052] The cap 102 defines an annular volume VI02 centered on the longitudinal axis A100 and which is bordered by an internal radial wall 102b and an external radial wall 102c.

[0053] A passage 102d is provided in the thickness of the external radial wall 102c and allows to connect fluidly a conduit 446 provided in the internal part 44 of the main body 4 and the volume V102.

[0054] On the other hand, the inner wall 102b of the cap 102 ends with a chamfered edge 102e turned towards the volume V102 and converging towards the longitudinal axis A100 opposite the bottom 102f of the volume V102, that is to say in the direction of the rear of the cap 102.

[0055] The magneto-pneumatic system 100 also includes a cup 104 placed on the rear bottom of the central housing L2. In the example in the figures, the bottom of the central housing L2 is opposite its front opening and delimited by the internal part 44.

[0056] The magneto-pneumatic system 100 also includes an annular piston 106 equipped with two sealing segments 107a and 107b. In the example, the sealing segments are made by two O-rings received in two peripheral grooves 106a and 106b, respectively external and internal, formed on the piston 106. The O-rings 107a and 107b are not shown in [Fig. 1], which allows for a better visualization of the grooves 106a and 106b.

[0057] Alternatively, the sealing segments are formed by lip seals. According to another embodiment, they are mounted on the walls of the cap 102 opposite the piston 106.

[0058] The piston 106 is movable, parallel to the axes A2 and A100, being partially engaged in the volume V102 of the cap 102. Due to the engagement Partially positioned within the piston 106 in the housing V102 and with the sealing rings 107a and 107b bearing against the walls 102c and 102b, a variable-volume sealed chamber C100 is defined between the elements 102 and 106. This variable-volume chamber C100 is supplied with pressurized air from the conduit 446 through the passage 102d. Means not shown, such as a pressurized air source, a proportional valve, and a vent valve, allow the variable-volume chamber C100 to be supplied with pressurized air or vented to the atmosphere, depending on the sequence of mounting or dismounting the skirt 6 on the main body 4. The air pressure in the conduit 446 is controlled independently of the rotor drive air pressure 10 and the skirt air pressure in the conduits 442.

[0059] Alternatively, a portion of the rotor 10 drive air can be diverted to the duct 446. In this case, the variable volume chamber C100 can be supplied with pressurized air as soon as the turbine is running. According to another embodiment, the duct 446 can be supplied with pressurized air from air used in the sprayer 2 for another function, for example, from skirt air circulating in the ducts 442.

[0060] The piston 106 also defines volumes VI06 for receiving balls 108 which constitute elements for engaging the piston 106 with the external peripheral groove 646 of the sleeve 64.

[0061] Advantageously, a ball 108 is mounted in each volume V106.

[0062] Each ball 108 is received in a volume VI06 which it may or may not protrude through an opening 0106 which constitutes the outlet of each volume V106 on the internal peripheral surface S106 of the piston 106.

[0063] Each volume V106 is defined, on its side opposite its opening 0106, by a surface S106 converging forward in the direction of the longitudinal axis A100 and inclined with respect to this longitudinal axis at an angle of zero, preferably between 15° or 60°, preferably still between 30° and 50°.

[0064] The surfaces S106 of the different volumes V106 constitute cam surfaces for guiding the balls 108.

[0065] The magneto-pneumatic system 100 also includes a support 110, which is also annular in shape, centered on the longitudinal axis A100, and which is formed of a solid body 110a and a profile 110b, both made of a ferromagnetic material. The parts 110a and 110b of the support 110 are joined together by any suitable means, in particular by bonding, crimping, and / or welding.

[0066] Alternatively, the support 110 is a single piece.

[0067] The support 110 is equipped with positioning pins 110c around the longitudinal axis A100, opposite the piston 106.

[0068] The support 100 is also equipped with stops 1 lOd intended to engage in the volumes V106 from the rear of the piston 106, to hold the balls 108 in position in these volumes.

[0069] The support 100 carries a permanent ring magnet 112 which is disposed on the internal radial side of the support 100. In the example, the permanent magnet is attached to the profile 110b, for example by gluing.

[0070] On the other hand, the support 100, more particularly its body 110a defines a first internal frustoconical surface S110, centered on the longitudinal axis A100 and converging in the direction of the piston 106, and a second internal frustoconical surface S' 110, centered on the longitudinal axis A100 and diverging in the direction of the piston 106.

[0071] The magneto-pneumatic system 100 also includes a flat spring 114 which forms an elastic element for returning the piston 106, and preferably the support 110, forward.

[0072] The flat spring 114 is formed by a steel blade. The use of a flat spring such as that shown in the figures has the advantage of allowing a relatively large axial stroke of the piston 106, while the axial size of the spring 114 is minimal.

[0073] Alternatively, the flat spring 114 can be replaced by another elastic element, in particular an elastomer block or a spiral spring.

[0074] A method for mounting the skirt 6 onto the main body 4 is now explained.

[0075] This assembly takes place by an axial translational movement of the skirt 62, parallel to the longitudinal axis A2. This axial translation movement is represented by the arrow T in figures 1 and 3 to 6. No other movement of the air supply skirt 6 is necessary to mount it on the main body 4.

[0076] Thus, the mounting of the air supply skirt 6 on the main body 4 results exclusively from a relative translational movement between these elements of the sprayer 2.

[0077] In a preliminary step shown in [Fig. 1], the air supply skirt 6 is aligned with axis A2 and brought closer to the main body 4 to reach the position shown in [Fig. 3], which represents a first step in the assembly process. In this step, the rear end 644 of the sleeve 64 is engaged in the central housing L2, without coming into contact with the components of the magneto-pneumatic system 100.

[0078] The continuation of the assembly of the skirt 6 on the main body 4 brings the sleeve 64 to the stage of [Fig.4], where its rear end 644 is supported by its edge 642 against the permanent magnet 112, while the edge 647a is supported against the surface S' 110, which avoids plastic deformation of the end 644 at the end of the stroke.

[0079] In this step, a closed magnetic flux FM is established through the rear end 644 of the sleeve 64, through parts 110a and 110b of the support 110, and through the magnet 112, which has the effect of securing them together by means of an axial magnetic force The air inlet skirt 6, along with the support 110, is held in position within the central housing L2, as its movement is restricted between the cap 102 and the cup 104. The axial magnetic attraction force between parts 12 and 64 is parallel to the longitudinal axis A2, preferably centered on this axis, and results in the air inlet skirt being held against the main body. This force is therefore a holding force between these parts.

[0080] The permanent magnet 112 is chosen to exert on the sleeve 64 a magnetic holding force of sufficient intensity to retain in position the air supply skirt 6 on the main body 4, including when the latter is moved, for example when it is mounted on the wrist of the arm of a multi-axis robot or on a reciprocator, which subjects the air supply skirt to these accelerations potentially directed in a direction of extraction of the sleeve 64 with respect to the central housing L2.

[0081] In practice, the magnetic holding force exerted by the permanent magnet on the sleeve has an intensity II between 10 and 20 daN, preferably on the order of 15 daN, which allows effective holding of the air supply skirt 6 on the main body 4. On the other hand, the relatively moderate value of this intensity II of the magnetic holding force limits the risk of injury by pinching of an operator when the latter presents the air supply skirt 6 and engages the sleeve 64 in the central housing L2.

[0082] In step [Fig. 4], the air supply skirt 6 is hooked onto the body main 4 thanks to the magnetic force, but the bottom 628a of the hollow housing 628 remains separated from the front face 428 of the external part 42, by a non-zero axial distance d8, this distance d8 being measured parallel to the longitudinal axis A2. In particular, in this step, the seals 20 are not compressed and the sealing between the air circuits, formed by the ducts 422 and 622 and the grooves 628c and 628d, is not ensured with respect to the outside.

[0083] In the steps of Figures 1, 3 and 4, the spring 114 exerts a force on the support 110 to move it away from the cup 104, which has the effect of engaging the stops 110d in the different volumes V106, to the point that these stops 110d press on the balls 108 which themselves press on the cam surfaces S106 of the piston 106, which has the effect of pushing the latter towards the bottom 102f of the volume V102. The variable volume chamber Cl00 then has a minimum volume visible in particular in insert B) of [Fig.3].

[0084] In this position, each ball 108 rests against the chamfered edge 102e of the cap 102, so that it is held in position within the corresponding volume V106 without protruding radially from the wall 102b, in a direction radial to the longitudinal axis A100 and centripetal. Under these conditions, the balls 108 do not impede the sliding of the sleeve 64 in the central housing L2, particularly during the succession of steps in figures 1, 3 and 4. In particular, in step [Fig.4], the balls 108 are not engaged in the external peripheral groove 646.

[0085] From the step in [Fig. 4], the passage 102d is supplied with pressurized air, as represented by arrow A in Figures 4 to 6. This has the effect of pressurizing the variable volume chamber C100, which expands, i.e., dilates, towards the cup 104, as can be seen from the comparison of Figures 4 and 5. This axial expansion of the chamber C100 results from an axial displacement, parallel to the longitudinal axis A2, of the piston 106 towards the cup 104, represented by arrow D in Figures 5 and 6, this displacement being due to the difference between the pressure inside the variable volume chamber C100 and the external atmospheric pressure.

[0086] This displacement D of the piston 106 has the effect of displacing the various balls 108 towards the cup 104, and therefore towards the bottom of the central housing L2. These balls then become offset relative to the chamfered edge 102e of the wall 102b, as this edge no longer opposes a centripetal radial movement of the balls 108 through the openings 0106. However, given the inclined nature of the cam surfaces S106 of the various volumes V106, the displacement of the piston 106 towards the cup 104 exerts a centripetal force on the various balls 108 with respect to the longitudinal axis A2, represented by arrow F in [Fig. 5] and directed towards the external peripheral groove 646. Thus, the air supply to the chamber C100 allows the various balls 108 to tighten around the sleeve 64, engaging them, that is to say by making them penetrate at least partially into the external peripheral groove 646.The balls 108 therefore constitute elements for engaging the piston 106 with the external relief of the sleeve 64 formed by the peripheral groove 646.

[0087] During the sequence of steps in Figures 4 and 5, the balls 108 push the support 110 towards the cup 104, against the elastic force exerted by the spring 114, which has the effect of axially separating the spring 112 and the end 644 of the sleeve 64. In other words, in the step of [Fig. 5], the rear edge 642 of the sleeve 64 is no longer in contact with the magnet 112 and the edge 647a is no longer in contact with the surface S' 110. This is not a problem since the balls 108 engaged in the external peripheral groove 646 then effectively retain the sleeve 64 in the central housing L2.

[0088] At the end of the step in [Fig.5], the value of the distance d8 has decreased compared to its value in the step in [Fig.4], but this value remains non-zero.

[0089] The continued supply of pressurized air to the variable volume chamber C100 through passage 102d results in the continued movement of the piston 106 towards the cup 104, against the elastic force exerted by the spring 114, in the direction of arrow D in [Fig. 6]. During this movement, the balls 108 come to rest against the rear edge 646a of the external peripheral groove 646 and transmit to the sleeve 64 the displacement force which they undergo due to the movement of the piston 106 in the direction of arrow D. Thus, the sleeve 64 is moved at the same time and over the same stroke as the piston 106, towards the bottom of the central housing L2, which is represented by the displacement arrow D' in [Fig.6].

[0090] This displacement D' of the sleeve 64 inside the central housing L2 has the effect of firmly pressing the bottom 628a of the recessed housing 628 against the front face 428 of the external part 42 of the body 4 by compressing the seals 20, which fluidly isolates the conduits 422 and 622 and the grooves 628c and 628d from the outside. In other words, the pneumatic mechanism 100B exerts, on the sleeve 64 and by means of the balls 108, an axial mechanical clamping force, parallel to the longitudinal axis A2, which firmly presses the bottom 628a of the recessed housing 328 of the air supply skirt 6 against the front face 428.

[0091] Thus, the positioning and immobilization of the air supply skirt 6 on the main body 4 is carried out in two stages thanks to the magneto-pneumatic system 100. The pneumatic mechanism 100B is therefore also a locking mechanism of the air supply skirt 6 on the main body 4.

[0092] The mechanical latching device 100A, which includes elements 110 and 112, holds the air supply skirt 6 in position on the body 2 before the pneumatic clamping mechanism 100B, which includes elements 102, 106, 108 and 110, is used by supplying the variable volume chamber C100 with pressurized air to effectively clamp the air supply skirt 6 in place on the main body 4, in particular by compressing the seals 20. The cup 104 and the spring 114 are accessories of the mechanical latching device 100A and the pneumatic clamping mechanism 100B within the magneto-pneumatic system 100.

[0093] The mechanical clamping force obtained by means of the pneumatic clamping mechanism 100B has an intensity 12 strictly greater than the intensity of the magnetic force mentioned above.

[0094] For example, the mechanical force obtained with the pneumatic clamping mechanism 100B can have an intensity between 80 and 200 daN, preferably between 100 and 150 daN, preferably even more in the order of 120 daN.

[0095] A method for mounting the air inlet skirt 6 onto the main body 4 comprises two main steps, namely - The act of inserting the sleeve 64 into the central housing L2 until the rear edge 642 comes into contact with the permanent element 112, which allows the magnetic latching device 100A to exert the latching force of the air supply skirt 6 on the main body 4, resulting from the magnetic flux FM shown in [Fig.4]; - Supplying pressurized air to the variable volume chamber C100 of the pneumatic clamping mechanism 100B, as represented by arrow A, has the effect of moving the piston 106 and the sleeve 64, respectively in the direction of arrows D and D' in [Fig.6] and of clamping the air supply skirt 6 onto the main body 4, in particular by compressing the seals 20.

[0096] When it is necessary to detach the skirt 6 from the main body 4, the supply of pressurized air to the variable volume chamber C100 is stopped and the passage 102d is opened to the atmosphere. The spring 114 then pushes the support 110, the balls 108 and the piston 106 towards the bottom 102f of the volume VI02, reducing the volume of the variable volume chamber C100.

[0097] The balls 108 then come to rest against the chamfered edge 102e of the wall 102b, which has the effect of returning them towards the interior of the volumes V106, extracting them from the external peripheral groove 646. In other words, the balls 108 are no longer in contact with the external peripheral groove 646. Thus, the elastic force exerted by the spring 114 tends to return the piston to a position in which the balls 108 can be freed from the external peripheral groove 646 of the sleeve 64.

[0098] When pushed back by the spring 114, the support 110 carries with it the magnet 112, which comes into contact with the rear edge 642 of the sleeve 64. This reactivates the magnetic holding force between the sleeve 64 and the magnet 112. The magneto-pneumatic system 100 is then in a configuration analogous to that of [Fig. 4], where the seals 20 are no longer compressed and the air supply skirt 6 remains attached to the main body 4 by the magnetic force resulting from the magnetic flux FM represented by the arrows F. The air supply skirt 6 is reliably held onto the main body 4 for the reasons explained above.

[0099] It is then possible to extract the air supply skirt 6 by exerting an axial force in the opposite direction to that of arrow T in figures 1 and 3 to 6.

[0100] In this regard, a dismantling tool 200, visible in Figures 7 and 8, can be used for this purpose. This tool is part of the sprayer 2, in that it is included with the sprayer when it is installed at a coating application site, and is provided with teeth 202 for gripping the internal ridges 648 of the sleeve 64, located at its front end 641. The ridges 648 are inclined relative to a longitudinal axis A64 of the sleeve 64 at a non-zero angle θ, for example, between 45 and 70°. The longitudinal axes A2, A64, and A100 coincide in the mounted configuration of the air supply skirt on the main body 4.

[0101] The dismantling tool 200 also includes a handle 204 for handling it by hand. It is therefore a manual dismantling tool.

[0102] When it is necessary to remove the air inlet skirt 6, the tool 200 is partially inserted into the sleeve 64 by an axial translation in the direction of arrow T' in [Fig. 7]. This tool is then rotated about the longitudinal axis A2 in the direction of arrow R in [Fig. 7] to engage the ridges 202 and 648. The ridges are then pressed against the nozzle 12 and the permanent magnet 14. Given the inclined nature of the ridges 648, rotating the tool 200 in the direction of arrow R exerts an axial separation force on the ridges 648 and the nozzle 12, which causes the rear edge 642 of the sleeve 64 to move away from the permanent magnet 112. The magnetic holding force is thus greatly reduced, even cancelled. It is then possible to exert an axial force on the handle 204 of the tool 200 in the direction of arrow T" in the [Fig.8], in the opposite direction to that of arrow T', which allows the air supply skirt 6 to be extracted, against the reduced magnetic force exerted by the magnet 112, or even in the absence of such a force.

[0103] According to a non-represented variant of the invention, it is possible to replace the manual dismantling tool 200 with an automatic dismantling tool, mounted at the end of a robot arm and which performs movements according to arrows T', R, and T", as explained above.

[0104] Whether with a manual dismantling tool or with an automatic dismantling tool, a method for dismantling the air supply skirt 6 from the main body 4 comprises successive steps consisting of - securing the dismantling tool 200 with the sleeve 64, in particular by cooperation of forms by means of a rotation; - exert on the dismantling tool an axial force T" to separate the sleeve 64 vis-à-vis the magnetic hooking device 100A.

[0105] Furthermore, the structure of the magneto-pneumatic system 100 of the invention is compatible with the installation of the air supply skirt 6 onto the main body 4 by means of a robot. Thus, according to one particular aspect, the present invention makes it possible to automate the mounting and dismounting of an air supply skirt on the main body of a sprayer.

[0106] The bowl 8 is not shown in Figures 3 to 8. It is placed in the central opening 06 of the air inlet skirt 6 after the latter has been hooked and tightened onto the main body 4, at the end of the step shown in [Fig. 6], using the magnetic force between the magnet 14 and the ferromagnetic body of the bowl. The bowl 8 is removed before using the tool 200.

[0107] In the second and third embodiments of the invention shown in Figures 9 and 10, the elements analogous to those of the first embodiment bear the same reference numerals. In what follows, if a reference numeral is used in the description without being shown in one of Figures 10 and 11, or if a reference numeral is shown in one of these figures, without being mentioned in the description, concern the same element as that bearing the same reference in the first embodiment.

[0108] In the second embodiment, the sprayer 2 is pneumatic, lacking a rotating bowl comparable to the rotating bowl 8 of the first embodiment. In this embodiment, a spray head 9 is mounted on an air supply skirt 6 which comprises a skirt body 62 and a sleeve 64 comparable to those of the first embodiment. The main body 4 of the sprayer 2 defines conduits 422 intended to be connected to conduits 622 provided in the skirt body 62. A magneto-pneumatic system 100 similar to that of the first embodiment is provided and allows the air supply skirt 6, already equipped with the spray head 9, to be attached to the main body 4, and then, by means of engagement members 108 engaged in a relief 646 of the sleeve 64, a clamping force is applied which allows, in particular, the compression of O-rings 20.

[0109] In an alternative embodiment not shown, the air inlet skirt 6 is mounted and tightened onto the main body 4 before the spray head 9 is mounted onto the air inlet skirt. According to another embodiment, the spray head 9 is mounted onto the main body 4 before the air inlet skirt 6 is mounted and tightened onto the main body 4.

[0110] The shape of the main body 4 shown in [Fig. 9] is not limiting. In particular, this main body 4 does not necessarily include a rotor and a fixed part forming a stator.

[0111] In the third embodiment, the annular permanent magnet 14 is carried by the air supply skirt 6, more particularly by the sleeve 64, at its front end 641. In particular, the bowl 8 rests on an internal radial collar 649 of the sleeve 64 in which the magnet 14 is integrated.

[0112] Thus, a sub-assembly consisting of the air supply skirt 6 and the bowl 8 can be mounted on the main body 4, or dismounted from it, in a unitary manner.

[0113] The sprayer 2 of this third embodiment is equipped with a magneto-pneumatic system 100 similar to that of the first embodiment.

[0114] Alternatively, in the third embodiment, the air supply skirt 6 can be put in place, hooked and tightened on the main body 4 in the first stage, the bowl 8 being attached to the air supply skirt in the second stage.

[0115] In this regard, in the first embodiment, it is possible as an alternative to hook and tighten the air supply skirt 6 on the main body 4 while the bowl 8 is already engaged in the central opening 06 of the air supply skirt.

[0116] Alternatively, and regardless of the embodiment, sprayer 2 is of the externally charged electrostatic type and comprises a high-voltage unit and charging electrodes (not shown), configured to bring the coating product sprayed by sprayer 2.

[0117] In a non-represented variant of the invention, when the sprayer 2 includes a spray bowl 8, the latter can be secured to the rotor 10 by means other than magnetic, for example by screwing.

[0118] According to another variant applicable to all embodiments, the sprayer is not of the electrostatic type.

[0119] According to another variant applicable to all embodiments, during the step in [Fig.4], the edge 642 of the sleeve 64 comes to rest against the support 110 and not against the magnet 112. This also makes it possible to create a closed magnetic flux of the type of the closed magnetic flux FM shown in [Fig.4].

[0120] Regardless of the embodiment, the magneto-pneumatic system 100 can be used automatically, utilizing the magnetic force generated by the permanent magnet 114 and controlling the supply of pressurized air into the variable volume chamber Cl00 or its discharge by means of valves controlled by an electronic control unit (not shown). Thus, the operation of the magneto-pneumatic system 100 during the assembly or disassembly of the air supply skirt 6 can be automated, thereby relieving an operator working near the sprayer 2 and making their work less hazardous.

[0121] Regardless of the embodiment, the variable volume chamber Cl00 of the magneto-pneumatic system 100 can, alternatively, be supplied with a pressurized gas other than air.

[0122] According to another unrepresented variant of the invention, the variable volume chamber C100 of the system 100 can be supplied with liquid, in particular water, to control the displacement D of the piston 106. In this case, the system 100 is a magneto-hydraulic system.

[0123] In an alternative applicable to all embodiments, the O-rings 20 are mounted in grooves formed on the bottom 628a of the recessed housing 628 and / or grooves equivalent to the grooves 628c and 628d are provided on the front face 428 of the external part 42 of the main body 4.

[0124] The invention is described above in the context of its use for spraying liquid coating products. It also applies to spraying powdered coating products.

[0125] As far as technically possible, the embodiments and variants mentioned above can be combined.

Claims

Claims

1. Coating product sprayer (2) comprising a main body (4), an air supply skirt (6) attached to the main body and a means (112) of magnetic attraction between the magnetic body and the air supply skirt, characterized in that the sprayer comprises a magneto-pneumatic or magneto-hydraulic system (100) which includes - a magnetic device (100A) for attaching the air supply skirt (6) to the main body (4); and - a pneumatic or hydraulic mechanism (100B) for locking and clamping the air supply skirt to the main body.

2. Coating product sprayer according to claim 1, characterized in that the magnetic attachment device (100A) is configured to exert, between the air supply skirt (6) and the main body (4), an axial magnetic force, parallel to a longitudinal axis (A2) of the sprayer, with a first intensity (II), in that the pneumatic or hydraulic clamping mechanism (100B) is configured to exert between the air supply skirt and the main body an axial mechanical force, parallel to the longitudinal axis of the sprayer, with a second intensity (12) and in that the second intensity is strictly greater than the first intensity.

3. Coating product sprayer according to claim 2, characterized in that it comprises seals (20) arranged between the air supply skirt (6) and the main body (4) and in that the seals compressed by the mechanical force exerted by the pneumatic or hydraulic clamping mechanism (100B) isolate conforming air circulation ducts (422, 622) arranged in the main body (4) and in a body (62) of the air supply skirt (6), from the outside of the sprayer (2).

4. Coating product sprayer according to one of the preceding claims, characterized in that the air supply skirt (6) comprises a sleeve (64) made of a ferromagnetic material, centered on a longitudinal axis (A2) of the sprayer (2) in the mounted configuration of the air supply skirt on the main body (4) and provided with at least an external relief (646) for cooperation with the pneumatic or hydraulic clamping mechanism (100B).

5. Coating product sprayer according to claim 4, characterized in that the magnetic attachment device (100A) comprises a permanent magnet (112) mounted on a support (110), movable parallel to the longitudinal axis (A2) of the sprayer (2) and in that the permanent magnet or the support is configured to receive in support one end (644) of the sleeve opposite a skirt body (62).

6. Coating product sprayer according to one of claims 4 and 5, characterized in that the pneumatic or hydraulic clamping mechanism (100B) comprises a piston (106), movable parallel to the longitudinal axis (A2) of the sprayer (2), inside a chamber (C100) selectively supplied with pressurized fluid, and in that the piston is equipped with members (108) for engaging with the external relief (646) of the sleeve (64).

7. Coating product sprayer according to claim 6, characterized in that the engagement members are balls (108), in that the piston comprises cam surfaces (S 106) inclined relative to the longitudinal axis (A2) of the sprayer (2) and in that, when the air supply skirt (6) is hooked onto the main body (4) by the magnetic hooking device (100A) and when the piston (106) is moved (D) towards an end (644) of the sleeve opposite a body (62) of the air supply skirt (6), the cam surfaces exert on the balls an engagement force (F) in the external relief (646) of the sleeve, this force being centripetal relative to the longitudinal axis.

8. Coating product sprayer according to one of claims 6 and 7, characterized in that it comprises at least one elastic member (114) for returning the piston (106) to a position in which the engagement members (108) are released from the external relief (646) of the sleeve (64).

9. Coating product sprayer according to one of the preceding claims, characterized in that it comprises a tool (200) for dismantling the air supply skirt (6), this dismantling tool comprising reliefs (202) for hooking onto the air supply skirt and being configured to exert on the air supply skirt a force (T") parallel to a longitudinal axis (A2) of the sprayer (2) and opposite to a magnetic force exerted on the air supply skirt by the device ma- hooking genetics (100A).

10. Method for mounting an air supply skirt (6) on a main body (4) of a sprayer (2) of coating product according to one of the preceding claims, characterized in that it comprises at least successive steps consisting of: a. introducing a sleeve (64) of the air supply skirt (6) into a central housing (L2) of the main body (4) until the magnetic attachment device (100B) exerts a magnetic force for attaching the air supply skirt to the main body; and b. supplying (A) the pneumatic or hydraulic clamping mechanism (100B) with pressurized fluid until the pneumatic or hydraulic clamping mechanism (100B) exerts a mechanical force for clamping the air supply skirt to the main body.

11. Mounting method according to claim 10, characterized in that the sprayer is according to claim 7 and in that during step b), the piston (106) moves the balls (108) towards a bottom of the central housing (L2), driving the sleeve (64) with the balls (108) engaged in the external relief (646).

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