Robots, systems, and methods for electrostatic powder coating

Abstract

To provide a robot for electrostatic powder coating.SOLUTION: Provided is an electrostatic powdering robot (4) for a powder booth (2), the robot (4) comprising an injector (41) for performing electrostatic powder coating. In order to reduce time required for powder removal from the booth and in order to facilitate automation of powder removal, the robot (4) further comprises a robotic arm (43) which is an articulation type and which carries the injector (41) for arranging the injector (41), and a blower (42) for blowing powder removal fluid, preferably air. The robotic arm (43) carrying the blower (42) to position the blower inside the electrostatic powder coating booth (2) so that the blower (42) blows the powder removal fluid onto a surface to be de-powdered inside the electrostatic powdering booth (2) and thereby removes the residual powder coating from the surface to be de-powdered.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a robot for electrostatic powder coating, an electrostatic powder coating system including such a robot, and an electrostatic powder coating method performed using such a robot or system.

Background Art

[0002] Electrostatic powder booths for applying coatings such as paints to articles by electrostatically powder coating the articles in the booth are known. The application of powder to the article is achieved by using an electrostatic injector that discharges a stream of powder while, at the same time, bringing the injector and the article to a specific potential so that the powder is attracted to the article and coats the article. After the article has been electrostatically powder coated, it is conveyed to an oven. The oven heats the powder to a temperature at which the thermosetting material in the powder is reticulated, thereby adhering the coating to the article.

[0003] Despite the electrostatic effect, some of the powder discharged to dust the article does not reach the article and tends to accumulate on the walls or floor of the booth or on the injector itself. Generally, the booth includes a residual powder suction system that evacuates the interior of the booth to collect much of this powder, recycle the collected powder, and mix it with fresh powder for dusting the next article. However, despite this vacuum system, generally, the residual powder remains adhered to the walls and floor, and it is necessary to remove the powder, i.e., clean the interior of the booth and the injector, especially when attempting to change the type of powder, for example, when changing the color. When performed manually by an operator, this operation requires the operation of the booth to be interrupted for safety reasons.

[0004] International Publication No. 96 / 12568 describes such a powder booth having a powder injector and an automatic cleaning unit. However, this automatic cleaning unit is very large and only suitable for the shape of a single booth. In addition, the cleaning unit needs to be moved from the outside to the inside of the booth for each cleaning operation, which is time-consuming. [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to improve upon the shortcomings of the prior art by providing a novel electrostatic powder coating robot, thereby reducing the time required for powder removal from the booth and facilitating the automation of powder removal. [Means for solving the problem]

[0006] The present invention relates to an electrostatic powder coating robot for an electrostatic powder coating booth, the electrostatic powder coating robot comprising an injector configured to perform electrostatic powder coating. According to the present invention, the electrostatic powder coating robot further comprises: an articulated robotic arm that carries and positions the injector inside the electrostatic powder coating booth so that the injector performs electrostatic powder coating of an article inside the electrostatic powder coating booth; and a blower configured to blow a powder removal fluid, preferably air, the robotic arm carries and positions the blower inside the electrostatic powder coating booth so that the blower blows the powder removal fluid onto the surface to be powder-coated, thereby removing any residual powder coating from the surface to be powder-coated.

[0007] One idea preceding the present invention is to mount an injector and a blower on the same electrostatic powdering robot and use that same robot to perform electrostatic powdering and powder removal (i.e., cleaning of residual powder). A robotic arm positions, i.e., moves, orients, and / or moves both the injector and the blower. Thus, when an article to be coated is present in the powder booth, the robotic arm positions the injector near the article and orients the injector towards the article to automatically perform powdering. Because the powdering robot is continuously equipped with a blower, once the article has been powdered, the powder booth is ready for powder removal. The robotic arm can then immediately orient the blower toward the surface from which the powder is to be removed, thereby positioning the blower so that the powder is removed from the surface. Powder removal can be performed at any desired time, in particular between the powdering of two consecutive articles. Because the robotic arm positions the blower, the surface from which the powder is to be removed may be the inner wall of the booth, the floor of the booth, the ceiling of the booth, or the surface of another injector or robot positioned within the booth. The feasibility of positioning the blower by a robotic arm makes powder removal highly versatile, as any desired surface inside the booth will have powder removed by the suitable positioning of the blower by the robotic arm. If the robotic arm is programmed for powder dispersal by an injector, it can also be programmed for powder removal by blower. Thus, powder removal can be easily automated.

[0008] Preferably, the robot arm includes a support head that supports the injector and blower so that the injector and blower are moved together as a single unit by the robot arm.

[0009] Preferably, the robot arm is a multi-jointed arm configured to position the ejector and blower with at least 5 degrees of freedom.

[0010] Preferably, the injector comprises a first row of electrostatic injection heads, and the blower comprises a row of injection nozzles arranged parallel to the first row of electrostatic injection heads.

[0011] Preferably, the injector includes a second row of electrostatic injection heads arranged parallel to a first row of electrostatic injection heads, and a row of blow nozzles is positioned between the first and second rows of electrostatic injection heads.

[0012] Preferably, the injector includes a powder dispersing electrode, and electrostatic powder dispersal includes bringing the powder dispersing electrode to a powder dispersing potential. Preferably, the electrostatic powder dispersing robot further includes a powder removal electrode independent of the powder dispersing electrode, the powder removal electrode being configured to be at a non-electrostatic potential while a blower blows a powder removal fluid onto the surface from which the powder is to be removed.

[0013] The present invention also relates to an electrostatic powdering system comprising an electrostatic powdering robot as defined above and an electrostatic powder coating booth. The electrostatic powdering robot is positioned such that an injector can be positioned inside the electrostatic powder coating booth to electrostatically powder an article inside the electrostatic powder coating booth, a blower can be positioned inside the electrostatic powder coating booth to blow a powder removal fluid onto the surface to be powdered.

[0014] Preferably, the electrostatic powder dispersal system further comprises another robot positioned inside the electrostatic powder coating booth. Preferably, the robot arm is configured to position the blower such that the blower blows a powder removal fluid to the other robot to remove the powder from the other robot.

[0015] Preferably, the powder dispersal system further comprises an auxiliary blower located inside the electrostatic powder coating booth and configured to blow a powder removal fluid. Preferably, the robotic arm is configured to position the injector near the auxiliary blower so that the auxiliary blower blows a powder removal fluid into the injector to remove powder from the injector.

[0016] Preferably, the blower is detachable from the robot arm. Preferably, the electrostatic powder coating system includes a tool changer designed so that the robot arm can acquire the blower when the blower is detached from the robot arm. Preferably, while the blower is detached from the tool changer and the robot arm can acquire the blower by the tool changer, the robot arm performs powder removal from the surface to be powdered, with the blower adapted to be automatically mounted in the tool changer to carry the blower.

[0017] The present invention further comprises, as an object of the present invention, an electrostatic coating system performed by an electrostatic powder dispersing robot or powder dispersing system as defined above. The electrostatic powder dispersing method includes electrostatically dispersing an article by an injector while the injector is positioned inside the electrostatic powder coating booth by a robotic arm, and blowing a powder removal fluid onto the surface to be powdered by a blower after electrostatic powder dispersing has been performed, while the blower is positioned inside the electrostatic powder coating booth by a robotic arm.

[0018] The present invention will be better understood and its advantages will become clearer from the following description of examples illustrating the principles of the present invention as shown in the attached drawings. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic cross-sectional view of an electrostatic powder dispensing system equipped with an electrostatic powder dispensing robot according to one embodiment of the present invention. [Figure 2] Figure 1 is a perspective view of a part of the electrostatic powder dispersing robot. [Figure 3] Figures 1 and 2 are exploded perspective views of a portion of an electrostatic dusting robot. [Modes for carrying out the invention]

[0020] Figure 1 shows an electrostatic powder spraying system including an electrostatic powder coating booth 2, an electrostatic powder spraying robot 4, and an electrostatic powder spraying robot 6.

[0021] The booth 2 is intended to surround the electrostatic powder spraying operation of the article 10. The article 10 is disposed inside the booth 2, and the powder spraying is performed using the robots 4 and 6.

[0022] In the example shown in Figure 1, the booth 2 includes a floor 12, a roof 14 extending above the floor 12, and a peripheral wall 16 connecting the floor 12 to the roof 14 along their respective outer perimeters. The booth 2 defines, inside the booth 2, a substantially enclosed powder section where powder spraying is performed, which is delimited by the floor 12, the roof 14, and the peripheral wall 16. The booth 2 is essentially intended to trap any residual powder that did not reach the article 10 during the powder spraying process inside it.

[0023] At least the interior of the booth 2 with respect to the floor 12, the roof 14, and the wall 16 is preferably made of or lined with an electrically insulating material, such as a polymeric plastic material.

[0024] Advantageously, the booth 2 includes an access opening 18 provided through the peripheral wall 16 for introducing the article 10 into the booth 2. The article 10 can be removed from the booth 2 either through this same access opening 18 or through a second similar access opening, for example, an access opening provided opposite the opening 18 at the other end of the booth 2.

[0025] Preferably, the powdering system comprises a conveyor 19 for introducing the article 10 into booth 2 through the opening 18 and for removing the article 10 from booth 2 through the opening 18 or another opening. The conveyor 19 comprises a rail 25 from which the article 10 is suspended, and the rail, for example, has means for moving the article 10 along the rail, such as a belt or a chain. Advantageously, the rail 25 is arranged above the roof 14, and preferably, the roof provides a longitudinal notch 26 below the rail 25 and following the trajectory of the rail 25. When the article 10 passes through the interior of booth 2, the article 10 is suspended from the rail 25 through the notch 26. Preferably, the article 10 is moved by the conveyor 19 without stopping inside booth 2, and powdering of the article 10 is performed while the conveyor 19 continuously effects the progressive movement of the article 10.

[0026] Preferably, the conveyor 19 is designed to continuously carry a plurality of articles distributed along the rail 25 for the continuous powdering of a plurality of articles inside booth 2.

[0027] Advantageously, the powdering system comprises a suction system connected to booth 2 for sucking up residual powder contained inside booth 2. For example, the suction system comprises a powder suction duct 21 arranged under the floor 12 and a vent 22 provided through the floor 12 so as to fluidly connect the interior of booth 2 to the duct 21, and the residual powder contained in booth 2 can be introduced into the duct 21 through the vent 22. Preferably, as shown, the floor 12 is formed by the assembly of inclined portions that facilitate the outflow of the residual powder towards the vent 22.

[0028] Advantageously, the suction of the residual powder sets the interior of booth 2 to a negative pressure with respect to the outside of booth 2, and air intake is effected through any opening of booth 2, such as the opening 18 and / or the notch 26, which avoids any leakage of residual powder from the booth through these openings.

[0029] To perform suction, the suction system comprises a powder suction pump 20 or any other suitable pumping means. Here, the pump 20 is located outside the booth 2 and is connected to a duct 21, which sucks out residual powder from the booth 2 through the vent 22 and the duct 21.

[0030] Preferably, all or part of the residual powder thus aspirated is then reintroduced into booth 2 for electrostatic dispersal, optionally after processing and / or mixing with new powder.

[0031] Article 10 is schematically shown in Figure 1, and powder coating can be applied to any type of article, especially metal articles, such as bicycle frames, furniture body parts or components.

[0032] By electrostatic powder dispersal, the powder applied to article 10 in booth 2 is intended to form a coating on article 10. Electrostatic powder coating allows the powder to be applied to desired portions of article 10 in a desired distribution. The powder is then reacted outside booth 2 without harming any subsequent processing in order to fix the coating and give it its final properties. Preferably, article 10 undergoes heat treatment using an oven to react the powder and cure the coating. Preferably, the resulting coating is a paint or varnish coating article 10.

[0033] Preferably, the powder comprises a thermosetting polymer material. After article 10 is scattered in booth 2, the heat treatment applied to article 10 cures the thermosetting material, i.e., creates a network structure, thereby curing the coating.

[0034] In this example, robots 4 and 6 are identical, and therefore the description of robot 4 applies to robot 6. In some variations, robot 6 is different from robot 4. In some variations, the electrostatic dusting system may be provided with a single electrostatic dusting robot or a number of electrostatic dusting robots other than two. These robots may be identical or different from one another. In particular, robots 4 and 6 may be different from one another, but both may be provided with separate blowers and injectors as described below, and separate robotic arms as described below for positioning the blowers and injectors. In some variations, both robots 4 and 6 are dusting robots, but only robot 4 has a blower, while the other does not.

[0035] Here, robot 4 is entirely located inside booth 2. Robot 4 substantially comprises an injector 41, a blower 42, and a robotic arm 43.

[0036] The robotic arm 43 carries the injector 41 and blower 42 and positions them inside the booth 2, that is, moves and orients them to a desired position inside the booth 2. In other words, the injector 41 and blower 42 can be positioned by the arm 43, which acts as a movable support for the injector 41 and blower 42. For this purpose, the arm 43 is articulated.

[0037] Preferably, the robot arm 43 is in the form of a multi-joint arm, i.e., a multi-axis robot. Thus, the robot arm 43 allows the injector 41 and blower 42 to be positioned according to any desired configuration inside the booth 2, and in particular, to conform to the shape of the booth 2 and the article 10 by simple control and / or programming of the robot arm 43.

[0038] The robot arm 43 comprises a base 45 and a support head 46, and preferably a plurality of elements connecting the base 45 to the head 46, in this case elements 47, 48, 49, and 50.

[0039] Preferably, the robot arm 43 is entirely housed inside the booth 2. In some variations, a portion of the arm 43, such as the base 45, may be outside the booth 2.

[0040] The robot arm 43 is supported by a base 45. Advantageously for this purpose, the base 45 is fixed to the booth 2, in this case to the floor of booth 2. The base 45 supports the injector 41 and blower 42 via a head and elements 47, 48, 49, and 50.

[0041] Element 47 is supported by a base 45 and is preferably articulated relative to the base 45 by a motorized joint 51, in a motorized manner that rotates it in yaw. Element 47 supports the other elements 49 and 50, the head 46, the injector 41, and the blower 42 via element 48. Thus, the movement of element 47 relative to the base 45 results in the integrated movement of elements 48, 49 and 50, the head 46, the injector 41, and the blower 42 relative to the booth 2.

[0042] Element 48 is supported by element 47 and is articulated to element 47, preferably via a motorized coupling 52, in a motorized manner that rotates it by pitch. Element 48 supports element 50, head 46, injector 41, and blower 42 via element 49. Thus, movement of element 48 relative to element 47 results in the integrated movement of elements 49 and 50, head 46, injector 41, and blower 42 relative to element 47.

[0043] Element 49 is supported by element 48 and is articulated to element 48, preferably via a motorized coupling 53, in a motorized manner that rotates it by pitch. Element 49 supports the head 46, injector 41, and blower 42 via element 50. Thus, movement of element 49 relative to element 48 results in the integrated movement of element 50, head 46, injector 41, and blower 42 relative to element 48.

[0044] Element 50 is supported by element 49 and is articulated to element 49, preferably via a motorized joint 54, in a motorized manner that rotates it on a roll. Element 50 supports the injector 41 and blower 42 via a head 46. Thus, movement of element 50 relative to element 49 results in the integrated movement of the head 46, injector 41 and blower 42 relative to element 49.

[0045] The head 46 is supported by an element 50 and is preferably articulated relative to the element 50 by a motorized joint 55, in a motorized manner that rotates it by a pitch. The head 46 supports the injector 41 and the blower 42. Therefore, the movement of the head 46 relative to the element 50 results in the integrated movement of the injector 41 and the blower 42 relative to the element 50.

[0046] Thanks to this structure, the robot arm 43 in this example allows the injector 41 and blower 42 to be positioned with 5 degrees of freedom relative to the booth 2. Here, the 5 degrees of freedom include 2 translational degrees of freedom relative to the booth, i.e., changes in height and lateral position, and 2 rotational degrees of freedom, i.e., pitch, roll and yaw. However, it may be required that the robot arm 43 have a number of degrees of freedom other than 5, particularly 6 degrees of freedom. Furthermore, it is preferable that the elements of the robot arm 43 are arranged in sequence, as in the illustrated example, such that a given element is supported by the preceding element in an articulated manner, and the next element is supported in an articulated manner, such that the first element is supported by the base 45 in an articulated manner, and the last element is supported by the head 46 in an articulated manner. Depending on the situation, a number of elements other than four may be provided, preferably at least two elements arranged such that the first element is supported by the base in an articulated manner, and the second element is supported by the first element in an articulated manner and supports the head in an articulated manner.

[0047] Preferably, the robot 4 includes an electronic unit 56 for controlling the arrangement of the injector 41 and blower 42 via the robot arm 43 by a pre-programmed method and / or manual control. For this purpose, the electronic unit 56 controls the robot arm 43 by specifically controlling motorized couplings 51, 52, 53, 54 and 55 to manipulate the arrangement of the elements, and the arrangement of the injector 41 and blower 42 depends on the arrangement of those elements. For example, the unit 56 includes an electronic controller connected by wired connections to each coupling to operate each coupling, and connected by wired connections to a human / machine interface for human programming and control of the electronic controller.

[0048] Figures 2 and 3 show preferred embodiments of the head 46, injector 41, and blower 42 in more detail. The blower 42 is shown separately in Figure 3.

[0049] The injector 41 is configured to electrostatically disperse the article 10 by being positioned inside the booth 2 by a robotic arm 43. Here, the entire robot 4 is inside the booth 2, but it is intended that at least the injector 41 and blower 42 are inside the booth 2 so that the ejected powder remains trapped inside the booth 2.

[0050] In this example, the injector 41 is equipped with eight injection heads 61. However, the injector may consist of a single injection head or a number of injection heads other than eight.

[0051] Advantageously, each ejection head 61 is mounted on a support head 46 of a robotic arm 43 and fixed to the support head 46, forming an automated gun.

[0052] Each injection head 61 incorporates a flat, round, or spiral spray nozzle 62 to discharge a spray of powder of a desired shape onto the article 10. All heads 61 can be selected to have the same nozzle 62, or the nozzles on the heads can be different to produce jets with different characteristics.

[0053] Preferably, each nozzle 62 of each injection head 61 is supplied with powder individually, for example, by a supply line 63 connected to the back of each injection head 61. Preferably, the powder can be selectively sprayed through only the selected head 61. Preferably, the powder is delivered to the nozzles 62 via the line 63 under the operation of a powder pump, which is supplied with fresh powder from a new powder source and / or recycled powder from residual powder recovered by the aforementioned suction system.

[0054] As an alternative to the nozzle 62, each head 61 may be provided with a rotating bowl.

[0055] Advantageously, the powder supplied to each head 61 may be different from the powder supplied to the other heads, for example, being powders of different colors, or one powder being intended to form a varnish while another powder is intended to form a paint or primer.

[0056] In certain modifications, it may be required that all or some of the injection heads 61 be supplied with the same powder and / or operate together.

[0057] Furthermore, each injection head 61 incorporates a high-voltage unit 66 that applies a voltage to the electrodes of the injection head 61, which is schematically shown transparently for a single head 61 in Figure 2. The electrodes 64 are brought to a potential called the "dispersion potential" by the high-voltage unit 66. The dispersion potential is a high potential and preferably continuous. When the electrodes 64 are at the dispersion potential, the electrodes apply this dispersion potential directly to the powder in the powder jet or to the powder near the powder jet to obtain a corona effect. For example, the electrodes 64 may be formed at the end of the head 61 or in the form of multiple electrodes around the head.

[0058] To generate an electrostatic field that tends to cause powder from the powder jet to adhere to the article 10, it is preferable that the article 10 is grounded and the powder dispersal potential is a negative DC potential, for example -80kV (kilovolts). More generally, it is preferable that the powder dispersal potential is -70kV to -90kV. "Continuous" means that the powder dispersal potential applied by electrode 64 does not change sign. In some variations, depending on the application, the type of powder and the type of article, it may be required that the powder dispersal potential has a positive sign, for example +70kV. Preferably, the article 10 is grounded via a conveyor 19, and the conveyor 19 itself is also grounded. More generally, a high potential difference is provided between electrode 64 and article 10, where the powder dispersal potential applied to electrode 64 is far from the potential applied to article 10, specifically much smaller than the potential applied to article 10.

[0059] For electrostatic powder dispersal, all heads 61 can be operated simultaneously. In certain modifications, particularly when heads 61 discharge different powders and / or jets with different characteristics, or when it is desired to change the powder for one head 61 while another head 61 is dispersing it, specific heads 61 can be selectively operated.

[0060] In this example, as shown in Figure 2, the heads 61 are arranged in two parallel rows 71 and 72, where both rows 71 and 72 have the same number of heads 61. For example, for each row 71 and 72, the heads 61 are arranged at regular intervals. Preferably, each head 61 in row 71 is positioned opposite one of the other heads 61 in row 71. Thus, the heads 61 can also be considered to be arranged in pairs, with each pair consisting of one head 61 in row 71 and one head in row 72. For example, for each pair, the two heads 61 are positioned in columns perpendicular to rows 71 and 72.

[0061] Preferably, the heads 61 are fixed to the support head 46 during the use of the injector 41 and while the robot arm 43 is positioning the injector 41. The injector 41 is designed to electrostatically disperse the article 10 while the article 10 is positioned in a predetermined area in front of the injector 41. In other words, the injector 41 is positioned facing the article 10 and within a predetermined distance from the article 10. This range may depend on which heads 61 are performing electrostatic dispersal at that time. In this example, all heads 61 are oriented along the same direction X41 fixed to the support head 46, or at least along a direction close to direction X41. For example, for each pair of heads 61, the two heads are oriented along a transport direction parallel to direction X41.

[0062] In summary, electrostatic powdering of article 10 means that while the injector 41 is positioned inside the booth 2 to target article 10 and is at a predetermined distance from article 10, the injector 41 releases a powder jet, creating a high potential difference between the injector 41 and article 10. In particular, this condition is met when a high potential difference is created and one of the heads 61 releases a powder jet while the heads 61 are correctly positioned relative to article 10. During electrostatic powdering, the injector 41 may be stationary or movable under the operation of the robotic arm 43 to coat article 10 with powder.

[0063] Advantageously, the electrostatic dispersal of article 10 is carried out jointly by robots 4 and 6 using their respective injectors, for example, each robot performing electrostatic dispersal on opposite sides of article 10 or on parts of article 10 that are separated from each other.

[0064] The blower 42 is configured to blow air into the booth 2 towards the surface to be powdered, and for this purpose is positioned inside the booth 2 by a robotic arm 43. The air can be discharged in a continuous or pulsed manner in one or more jets, preferably flattened jets. The purpose of this air blowing is to remove, i.e., detach, any residual powder coating the surface to be powdered, which has accumulated incidentally during electrostatic powdering. Removing the residual powder leaves it suspended inside the booth 2, thereby facilitating its suction by the aforementioned suction system. Preferably, the suction system is activated during and / or after the powder removal performed by the blower 42.

[0065] The fact that the blower 42 blows air rather than another fluid is advantageous because the same compressed air generator can supply both the injector 41 for powder spraying and the blower 42 for powder removal. Since air is a gas that does not mix with residual powder, the residual powder is not contaminated and can be more easily reused for further electrostatic powder dispersal. However, it may be required that the blower 42 blow or spray any other suitable powder removal fluid, such as another gas or even a liquid.

[0066] Any surface inside the booth 2 may be a surface from which powder is removed, as long as the robot arm 43 can position the blower 42 to remove the powder from the surface. In particular, the surface from which powder is removed may be all or part of the floor 12, walls 16 and roof 14. The surface from which powder is removed may be part of the conveyor 19 located inside the booth 2.

[0067] Advantageously, the blower 42 of robot 4 is expected to perform powder removal on all or part of the other robot 6, which then constitutes the surface from which the powder is removed. In particular, robot 4 can perform powder removal on the injector 41 or blower 42 of the other robot 6. Conversely, if robot 6 is equipped with a blower 42, robot 6 can perform powder removal on robot 4. More generally, robot 4 can be responsible for powder removal on any robot or equipment contained in booth 2 (whether it is a powder-spreading robot or a robot with another function), for example, handling article 10, or another automated device, for example, a jack or wire contained in booth 2.

[0068] In a certain modification, for example, if the wrong powder is applied to article 10, if it is necessary to remove excess powder from article 10, or to achieve a specific surface finish for article 10, article 10 can be provided as a surface from which powder can be removed.

[0069] Here, the blower 42, shown in detail in Figures 2 and 3, comprises six blow nozzles 81. However, the blower 42 may consist of a single blow nozzle 81 or a different number of nozzles 81 other than six.

[0070] Each nozzle 81 is mounted on the support head 46 of the robot arm 43 so as to be immovable relative to the support head 46. Therefore, preferably, the nozzles 81 are stationary relative to the injection head 61. More generally, the transport of the injector 41 and blower 42 relative to the support head 46 means that they are moved simultaneously, i.e., as a single unit, by the robot arm 43, as described above. Preferably, the injector 41 and blower 42 are configured to be stationary relative to the head 46 during electrostatic powder dispensing and powder removal.

[0071] The nozzles 81 are supplied with powder removal fluid, in this case air, by a supply manifold 82 that simultaneously distributes a single flow of powder removal fluid to all 81 nozzles 81. In other words, the supply of fluid to the manifold 82 results in the simultaneous discharge of fluid from all 81 nozzles 81. Preferably, the nozzles 81 are mounted to the support head 46 via the manifold 82, and the manifold 82 itself is mounted to the head 46.

[0072] Here, the blow nozzle 81 is positioned in row 91 between rows 71 and 72, parallel to rows 71 and 72 of the injection head 61.

[0073] Advantageously, each blow nozzle 81 is in the form of a flattened jet nozzle, which is particularly effective for removing residual powder. Advantageously, each nozzle 81 is oriented such that the flattened jet is directed along direction X41, parallel to row 91, and toward direction X41. In this configuration, the combination of flattened jets from the nozzles 81 forms a flattened flow of powder removal fluid directed along direction X41 and parallel to row 91, i.e., a planar curtain of powder removal fluid. This is particularly effective in removing residual powder from the powder-removed surface.

[0074] In some variations, it may be required that all or some of the blow nozzles emit jets of different shapes, such as round jets.

[0075] Preferably, the injector 41 and blower 42 are oriented along the same direction X41, which facilitates the programming of the robot 43 for the arrangement of the head 61 and nozzle 81, and the flow of powder and powder removal fluid is discharged in the same direction.

[0076] Preferably, powder removal is performed while the access opening 18 is closed to prevent residual powder from being dispersed outside the booth 2. Preferably, powder removal is performed when electrostatic powdering is not taking place inside the booth 2. Preferably, powder removal is performed when there are no objects to be powdered or already powdered contained inside the booth 2 to avoid accidental contamination of the surface of articles by detached residual powder. In other words, first, electrostatic powdering of one or more articles 10 is performed by the injector 41. Then, after powdering, blowing is performed by the blower 42. Then, further powdering of other articles can be performed.

[0077] Advantageously, since the blower 42 is always positioned in booth 2, blowing is performed automatically between the dusting of two consecutive articles. For example, when two consecutive articles are positioned sufficiently far apart along the conveyor 19, or when the supply of articles to booth 2 is temporarily interrupted, it can be expected that dust removal will be performed in an orderly and automatic manner. Dust removal can be performed simultaneously by one robot or by multiple robots.

[0078] Optionally, the blower 42 may be equipped with an electrode 83 called a "powder removal electrode," which is independent of any powder dispersion electrodes that may be carried by the injector 41. The electrode 83 may be in the form of a single electrode or multiple electrodes. Here, the electrode 83 belongs to a deionization bar sometimes called an "ionization bar" or "active antistatic bar," and is, for example, integrated with the manifold 82 or otherwise integrated with the blower 42. In some modifications, the electrode 83 may be carried by another part of the robot 4 or even located elsewhere in the booth 2.

[0079] The purpose of electrode 83 is to improve the effectiveness of powder removal from the surface to be powdered, particularly when the surface to be powdered is the floor 12, wall 16, or roof 14. For this purpose, electrode 83 is set to a potential known as the “powder removal potential,” which is intended to deionize the powder removal fluid, the air near the surface to be powdered, the surface to be powdered, and / or any residual powder stirred up during blowing. This avoids the tendency for the powder to reattach to the surface to be powdered or another surface due to electrostatic effects. For this purpose, preferably, the powder removal potential is a high potential of alternating current, or at least a high potential whose value changes sign. For example, a high potential of alternating current is desired to be 10 kV. More generally, it is assumed that the potential is at least 7 kV. Advantageously, it is assumed that electrode 83 is set to the decoupling potential by a high-voltage unit attached to the blower 42, a high-voltage unit supported elsewhere in the robot, or an external high-voltage unit, where this high-voltage unit is incorporated into the deionization bar. In either case, preferably, the high-voltage unit for electrode 83 is located away from the high-voltage unit 66.

[0080] In addition, or in some modifications, the blower 42 itself may be provided with one or more electrodes that are subjected to a high voltage during blowing in order to facilitate this separation of residual powder.

[0081] In summary, blowing a surface to be de-powdered means that while the blower 42 is positioned inside the booth 2 to target the surface to be de-powdered, the blower 42 discharges a jet of powder removal fluid while it is at a predetermined distance from the surface to be de-powdered. During blowing, the blower 42 may be static or movable under the movement of the robot arm 43 so that the surface to be de-powdered is effectively de-powdered.

[0082] Preferably, the robot 4 includes an electronic unit 65 for controlling the operation of the injector 41 and blower 42, i.e., for controlling the supply and / or discharge of powder and fluid by pre-programmed methods and / or manual control. For this purpose, the electronic unit 65 controls, in particular, the injection head 61 and the blow nozzle 81 and / or manifold 82, for example, by a set of solenoid valves. For example, the unit 65 includes an electronic controller, which is wired to the head 61, the nozzle 81 and / or manifold 82, or other components of the powder and fluid network supplying them, and is wired to a human-machine interface for programming and controlling the electronic controller by a person.

[0083] As shown in Figure 1, it is advantageous that the dusting system includes an auxiliary blower 29 separate from the blowers 42 provided on robots 4 and 6. Preferably, the auxiliary blower 29 is fixed, for example, internally, and supported by the floor 12, walls 16, or roof 14 of booth 2. Similar to the blower 42, the auxiliary blower 29 is provided for blowing a dust removal fluid, preferably air. For example, the auxiliary blower 29 is the same as the blower 42. This auxiliary blower 29 is used for dust removal from robot 4, particularly its injector 41, which can hardly be dusted by the blower 42 of robot 4. To perform dust removal on robot 4, it is advantageous that the robot arm 43 of robot 4 positions the injector 41, or any other surface from which dust will be removed by robot 4, near the auxiliary blower 29, particularly in the path of the flow of the dust removal fluid being discharged. Thus, dust removal by robot 4 is operated by the auxiliary blower 29, particularly the injector 41. The removal of powder by robot 6 can be operated in a manner similar to that for any other robot provided in booth 2, in particular robot 6. The presence of blower 29 is especially advantageous when booth 2 is provided with a single robot, for example robot 4, or when booth 2 is provided with multiple robots, one of which is equipped with blower 42.

[0084] The above describes a case where the injector and blower are permanently attached to the robotic arm. However, in some variations, it may be required that part or all of the blower, and / or part or all of the injector, be actually detachable from the robotic arm, preferably automatically.

[0085] In particular, the powdering system can be assumed to include a tool changing device 90, very schematically shown in Figure 1, which is located, for example, in booth 2. This device 90 makes one or more spare tools available to one or more robots. For example, the device 90 may take the form of a rack having separate slots for each spare tool, or slots that are interchangeable and useful for multiple spare tools.

[0086] In particular, the robotic arm 43 has access to a device 90 for automatically attaching and detaching the injector 41 and / or blower 42, depending on the operation being performed. In this case, the injector 41 and / or blower 42 are presented as spare tools that can be selectively attached to the robotic arm 43. For example, during an electrostatic powdering operation, only the injector 41 is supported by the robotic arm 43, while the blower 43 is detached from the robotic arm 43 and supported by the device 90, waiting for further use. To perform a powder removal operation, the robotic arm 43 supports the blower 42 by automatically attaching it to the robotic arm 43 in the device 90. Advantageously, for attaching the blower 42, the robotic arm 43 may be required to have previously detached the injector 41 by entrusting it to the device 90. To perform an electrostatic powdering operation, the robotic arm 43 supports the injector 41 by automatically attaching it to the robotic arm 43 in the device 90. In order to install the injector 41, it may be advantageous that the robot arm 43 has previously removed the blower 42 by entrusting it to the device 90.

[0087] Any feature from one embodiment or variation described above can be made in any other embodiment or variation described above, to the extent that it is technically possible.

Claims

1. An electrostatic powder dispersing robot (4) for an electrostatic powder coating booth (2), Injector (41) configured to perform electrostatic powder dispersal. Equipped with, The injector (41) performs the electrostatic powder dispersal of the article (10) inside the electrostatic powder coating booth (2), and the robotic arm (43) is articulated and moves the injector (41) so that it is positioned inside the electrostatic powder coating booth (2); A blower (42) configured to blow out a powder removal fluid and The robot arm (43) moves the blower (42) inside the electrostatic powder coating booth (2) to position it so that the blower (42) blows the powder removal fluid onto the surface to be powder-removed, thereby removing any residual powder coating from the surface to be powder-removed. The injector (41) is equipped with a powder dispersing electrode (64), and the electrostatic powder dispersal includes setting the powder dispersing electrode (64) to a powder dispersing potential; and The electrostatic powder dispersing robot (4) is characterized in that it further comprises a powder removal electrode (83) independent of the powder dispersing electrode (64), and the blower (42) is configured to bring the powder removal electrode (83) to a non-electrostatic potential while blowing the powder removal fluid onto the surface from which the powder is to be removed.

2. The electrostatic dust dispersing robot (4) according to claim 1, wherein the robot arm (43) is equipped with a support head (46) for carrying the injector (41) and the blower (42) so that the injector (41) and the blower (42) are moved together by the robot arm (43).

3. The electrostatic dust dispersing robot (4) according to claim 1 or 2, wherein the robot arm (43) is a multi-jointed arm configured to position the injector (41) and the blower (42) with at least 5 degrees of freedom.

4. The injection device (41) is equipped with a first row (71) of an electrostatic injection head (61), and The electrostatic dust dispersing robot (4) according to any one of claims 1 to 3, wherein the blower (42) comprises a row (91) of blow nozzles (81) arranged parallel to the first row of the electrostatic injection head.

5. The electrostatic powder dispersing robot (4) according to claim 4, wherein the injector (41) comprises a second row (72) of the electrostatic injection head (61) arranged parallel to the first row (71) of the electrostatic injection head (61), and the row (91) of the blow nozzle (81) is arranged between the first row (71) and the second row (72) of the electrostatic injection head (61).

6. The electrostatic dusting robot (4) according to any one of claims 1 to 5; The electrostatic powder coating booth (2) and The robot arm (43) is equipped with The injection unit (41) can be positioned inside the electrostatic powder coating booth (2) so as to perform the electrostatic powder dispersal of the article (10) inside the electrostatic powder coating booth (2); and The blower (42) can be positioned inside the electrostatic powder coating booth (2) in order to blow the powder removal fluid onto the surface from which the powder is to be removed. An electrostatic powder dispensing system in which the aforementioned electrostatic powder dispensing robot is installed.

7. The electrostatic powder dispersal system further comprises another robot (6) located inside the electrostatic powder coating booth (2); and The electrostatic powder dispersal system according to claim 6, wherein the robot arm (43) is configured to position the blower (42) such that the blower (42) can blow the powder removal fluid to the other robot (6) to remove the powder from the other robot (6).

8. The powder dispersing system further comprises an auxiliary blower (29) located inside the electrostatic powder coating booth (2) and configured to blow powder removal fluid; and The electrostatic powder dispersal system according to claim 6 or 7, wherein the robot arm (43) is configured to position the injector (41) near the auxiliary blower (29) so that the auxiliary blower (29) blows a powder removal fluid onto the injector (41) to remove powder from the injector (41).

9. The blower (42) is detachable from the robot arm (43); The electrostatic dusting system includes a tool changer (90) adapted to allow the robot arm (43) to acquire the blower (42) when the blower (42) is detached from the robot arm (43); and The electrostatic dusting system according to any one of claims 6 to 8, wherein the blower (42) is detached from the robot arm (43) and the robot arm (43) is adapted to automatically attach the blower (42) to itself in the tool changer (90) so that the blower (42) can be carried and the dust removed from the surface to be dusted while the blower (42) is detached from the robot arm (43) and the blower (42) can be acquired by the tool changer (90).

10. The electrostatic powder dispersing robot (4) according to any one of claims 1 to 5, wherein the powder removal fluid is air.

11. An electrostatic powdering method performed by an electrostatic powdering robot (4) according to any one of claims 1 to 5 or a powdering system according to any one of claims 6 to 9, While the injector (41) is positioned inside the electrostatic powder coating booth (2) by the robot arm (43), the injector (41) electrostatically disperses the article (10), wherein the electrostatic dispersing includes bringing the dispersing electrode (64) to a dispersing potential; After the electrostatic powder scattering is performed, while the blower (42) is positioned inside the electrostatic powder coating booth (2) by the robot arm (43), the blower (42) blows the powder removal fluid onto the surface from which the powder is to be removed, wherein the powder removal electrode (83) is configured to be at a non-electrostatic potential while the blower (42) is blowing the powder removal fluid onto the surface from which the powder is to be removed. A method of electrostatically dispersing powder, including the method described above.

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