Patent Application
20230124016
The invention relates to an atomizer changeover system, which can preferably change fully automatically high-rotation and pneumatic atomizers on multi-axis hollow-wrist coating robots.
When coating or painting high-quality components, as is customary, inter alia, in the automobile industry, high demands are placed on the coating.
These cannot be depicted with a single coating material, but a coating system consisting of a plurality of layers is required here, wherein each layer fulfills a defined task.
Thus, it is common for three-layer to four-layer structures to be used in the automobile sector.
Such multilayer coating systems generally comprise a primer coating agent, at least one basecoat and at least one (2-component) clearcoat. Each of these coating agents is generally applied with different atomizers because of different characteristics and different application layer thickness to be achieved. In addition, the composition of the coating agents plays a considerable role. Thus, for example, water-based or solvent-based basecoat materials exist, while typical 2-component clearcoat materials are solvent-containing. The change between water-based and solvent-containing coating materials is not possible after the coating process has taken place without prior cleaning of the application device, since the contact between the coating materials or mixing of these generally leads to undesired reactions.
A further application problem is that high-speed rotary atomizers are inferior to the pneumatic atomizers with regard to the reachability of surfaces that are difficult to access, since they are significantly larger in terms of structural design.
The manual conversion of a robot to the respective atomizer must be avoided due to the setup time and the associated stoppage of the painting process in the painting cabin or the entire painting line. For this reason, a separate robot is generally required for each individual atomizer.
Tool change systems for so-called handling robots are known.
These comprise a centrally arranged clamping element in order to be able to grip and lock the coupling element (slave) located on the tool with the coupling element (master) located on the robot. Depending on requirements, various modules are fitted around this clamping element in order to couple the substance, energy and information streams required for the function of the tool. These coupling systems are continuously made of conductive materials and therefore cannot be installed in the high-voltage field. They are established for use on a handling robot without a “Hollow-Wrist”.
Automatic atomizer changeover systems are also already known from the field of painting technology (Prauser & Brinckmann in: Journal for Surface Technology 2013(7) 20-21).
These comprise a robot-side master plate, via which various slave plates can be received, to which the atomizers are mechanically mounted and hosed. The slave units are located in change stations within a paint booth. Thus, a robot can change the atomizers fully automatically. The change-over system can couple any media and signals necessary for operation of a high-speed rotary atomizer and is suitable for operation of atomizers with external and internal charging as well as paint guns. Here too, the actual clamping element is located in the center, similarly to the above-described tool change system, while the actual coupling points for substances, energy and information are arranged on the outside. This arrangement occupies a lot of space, which has a negative effect on the entire kinematics. In addition, in the above-mentioned atomizer change system, components such as couplings, clamping system, holders, etc. are metallic, which leads to undesired side effects in the atomizer change system.
Operation under high voltage (free capacitances) may result. Furthermore, the entire hose guide of the slave unit is open and largely unprotected, whereby the entire unit is susceptible to contamination by overspray.
In the field of application of motor vehicle painting, so-called “Hollow Wrist” painting robots are in multiple use.
These typically have four, five or six axes and have the special feature that the lines for substances, energy and information are guided through the “hollow wrist” (“woodlow wrist”) of the robot and are thus inaccessible to contamination by overspray. In addition, the “bright” construction also makes it possible to reach locations of the material to be painted which would not be accessible when the lines are guided externally. However, the change of atomizers on such multi-axis hollow-wrist laminating robots has hitherto been complex, in particular time-consuming and can only be carried out manually.
The object of the invention is to provide an atomizer replacement system which does not have the disadvantages of the prior art and in particular uses this space in the case of atomizers having a greater space requirement in an optimal manner and thus improves the accessibility of the surfaces to be painted, especially in the case of complex three-dimensional substrates to be painted.
At the same time, an external contamination of the lines carrying the substances, energy and information, for example by overspray, is to be minimized. A lower contamination of the lines should thus make it possible to reduce the alternating times between different atomizers and also to reduce the risk of contamination of subsequent lacquer layers by externally soiled hoses and lines.
In addition, the atomizer changeover system is intended to enable a fast, fully automatic changeover between different atomizers and thus also different coating agent systems.
The number of coating robots required for multicoat coating should also be reduced, in that a coating robot, in rapid change, with different atomizers. It can be equipped. This permits the application of various coating compositions, such as, for example, aqueous or solvent-based, one- or two-component coating compositions.
It is particularly advantageous to use the atomizer changing system with different atomizers such as, for example, high-rotation atomizers and pneumatic atomizers.
Preferably, any conventional type of atomizer should be usable.
The sprayer changing system is intended to be usable on a multi-axis painting robot, so that the painting robot, without human intervention, is able to change the sprayer independently.
The above-mentioned objects could be achieved by providing an atomizer change system for a multi-axis hollow-width coating robot, wherein the atomizer change system comprises a master unit (1) and at least one slave unit (2), and wherein the master unit (1) has at least the following components: a releasable master-side connecting element (1.1) surrounding the center of the master unit (1) for the force-locking and form-locking connection (KS, FS) of the master unit (1) to the slave unit (2), a master-side coupling plate (1.2) arranged in the center of the master unit (1) with a plurality of coupling points for supplying a atomizer connectable thereto with substances, energy and/or information, and an adapter (1.3) for connecting the master unit (1) to a hollow-width frame of a coating robot; and wherein the slave unit (2) has at least the following components:
a slave-side coupling plate (2.2) for connecting the slave unit (2) to the master unit (1) and to an atomizer, wherein the slave-side coupling plate (2.2) is fixedly connected on the atomizer side to lines and/or an adapter plate for supplying the connectable atomizer with substances, energy and/or information; and a slave-side releasable connecting element (2.4) for connecting the slave unit (2) to an atomizer.
In the following, the atomizer changeover system is referred to as an atomizer changeover system according to the invention.
3: 1.2, 2.2).
The multi-axis coating robots are those with a “woodlow wrist”, that is, a “hollow wrist”.
All the lines required for supplying the atomizer can be guided through these lines.
A typical multi-axis coating robot is shown, for example, in
Support), in which this is designed as a 6-axis coating robot. The six axes are designated A1 to A6 in
Multi-axis Hollow-Wrist coating robots preferably have four, five, six or more axes.
In the context of the invention, they are particularly preferably six-axis hollow-wrist coating robots.
Whereas in the multi-axis coating robots known from the prior art, the lines for substances, energy and/or information required for supplying the atomizer run along the outside of the robot arm.
If both the space requirement and the tendency to fouling are increased, the atomizer replacement system according to the invention makes it possible, without firm installation of all lines from the hollow mill to the atomizer, to install or change various types of atomizers in a simple manner, both manually, but preferably fully automatically.
This is achieved in that the master unit (1) of the atomizer change system according to the invention is fixedly connected to the hollow roll of the coating robot via an adapter (1.3) and the master unit is designed in such a way that it has a master-side coupling plate (1.2), which is arranged in the center of the cross section and which has a plurality of coupling points which serve to supply the atomizer with substances, energy and/or information.
On the robot side, the lines required for this are firmly connected to the master-side coupling plate (1.2).
Unlike in the case of master-slave changing devices for typical handling robots, the robot surrounds it for connection or connection.
Locking of Master Unit (1) with Slave Unit (2) Required Connection. Locking mechanism (KS, FS) in the atomizer replacement system according to the invention is the master-side coupling plate (1.2) and is thus not located on the inside, but rather on the outside.
The connection or connection.
Locking mechanism is designed both in a force-locking manner (KS) and in a form-locking manner (FS).
The releasable master-side connecting element (1.1), which surrounds the center of the master unit (1) and allows the non-positive and positive connection (KS, FS) of the master unit (1) to the slave unit (2), is preferably designed as a flange, particularly preferably as a conical flange.
The construction according to the invention and in particular by a preferred additional nesting of the master-side clutch plate (1.2) with the slave-side clutch plate (2.2) also results in a radial increase in the pressure of the master-side clutch plate (2.2).
Resistance to dielectric strength.
The labyrinth of insulation walls resulting in the interaction of master-side clutch plate (1.2) and slave-side clutch plate (2.2) forms extended paths for any leakage currents and is therefore a particularly effective insulation measure which advantageously contributes to improving operational safety.
On the other hand, all lines for substances, energy and information are in the master (1), which increases the flexibility and reachability of the atomizers and simplifies the cleaning of the system.
Since the master-side coupling plate (1.2) is intended to have as far as possible a universal suitability for a wide variety of atomizers, from pneumatic atomizers up to high-rotation atomizers, it has a plurality of coupling points for supplying the respective atomizer with substances, energy and/or information.
The coupling of the necessary media, for example directly charged conductive media, is thus also possible.
The master-side coupling plate (1.2) particularly preferably comprises coupling points for coating agent lines, in particular those which are designed for operation with or without high voltage, coupling points for pneumatic lines, in particular for supply with turbine vents, bearing air, bearing air monitoring, steering vents, control vents, microphone vents, purge air, air for thermal insulation and braking air, and coupling points for optical waveguides.
In a very particularly preferred embodiment, the master coupling plate (1.2) has at least 28 coupling points, of which two medium-carrying lines for operation without high voltage, five medium-carrying lines for operation under high voltage, twenty pneumatic lines for turbine vents, bearing air, bearing air monitoring, steering vents, control vents, microphone vents, purge air, air for thermal insulation, brake air and an optical waveguide coupling.
The bearing air screw connection (
This guarantees that the stored air permanently present at the master unit (1) cannot escape in an uncontrolled manner, as a result of which costs and resources can be saved.
The atomizer replacement system according to the invention can also be used in high-voltage operation with corresponding atomizers up to approximately 100 kV, without the horizontal arm of the robot having to be designed in an insulated manner.
The atomizer replacement system according to the invention allows the use of the atomizer replacement system according to the requirements of the EU guidelines ATEX product guideline 2014/34/EU and for the ATEX Zone II 3G T3.
The atomizer replacement system according to the invention preferably consists essentially of an electrically non-conductive plastic.
Examples of suitable plastics are polyoxymethylene (POM) and polyether ether ketone (PEEK).
In this case, it is possible to manufacture the slave unit (2) completely from the electrically non-conductive plastic and to manufacture the master unit (1) at least largely from the non-conductive plastic. Thus, the master unit preferably contains less than 5% by weight, particularly preferably less than 3% by weight and very particularly preferably less than 2% by weight of metallic components. If the master unit (1) contains metallic components, these are generally plug-in screws; high-voltage contacts, ground contacts, and collecting cylinders (e.g. B. Spring and Piston). In spite of the weight-reduced construction using electrically non-conductive plastics, such a design permits the reliable adaptation of atomizers up to a weight of at least 10 kg, but certainly also higher weights such as up to 13 kg, up to 15 kg or higher.
It is advantageous for the center of gravity of the atomizer change system (including the atomizer) to be as close as possible to the hollow time of the coating robot.
Place. In order to achieve this, the master unit (1) is preferably designed as short as possible.
However, high voltage resistant equipment requires that certain insulation distances be maintained. These insulating paths are generally between 1.8 and 2.1 mm/kV and thus have a strong influence on the component dimensioning. In order to keep the insulating paths as low as possible, it is preferred that all media-carrying lines, i.e. the coating agent-carrying lines, have screw connections (1.21, 2.21) which are resistant to high voltages.
The master-side high-voltage screw connection (1.21) has, up to a certain voltage, a certain strength for possible leakage currents or, respectively, a certain strength.
Catches. In this case, in the combination nut/media line A/screwing in the fully assembled state, on the one hand the leakage current length is increased, and on the other hand the cavity between nut/media line/screwing is preferably filled with an electrically insulating material. Electrically insulating substances suitable for filling must have LABS conformity according to VDMA 24364:2018-05 (LABS=lacquer wetting-disturbing substances). These include correspondingly conformal special fats and correspondingly conformal vaseline.
The screw connection (1.21) described preferably has a penetration or penetration.
Creep current resistance of approximately 50 KV, whereby the insulating section can be halved.
The screw connections (1.21, 2.21) for media in general are preferably designed free of dead space in order to be able to implement the cleaning process or the complete evacuation of the lines filled with liquid media in the shortest possible time.
The slave unit (2) is adapted to the respective atomizer, the interface to the atomizer in this case forms the slave-side coupling plate (2.2) and a slave-side coupling plate (2.2).
A releasable connecting element (2.4) on the side of the slave, the latter preferably being designed as a flange (2.4).
The coupling plate (2.2) of the slave unit (2) has lines on the atomizer side and/or an adapter plate for substances, energy and information, preferably produced in the 3D printing process, and is fixedly connected to the atomizer.
The slave coupling plate (2.2) is occupied here with all coupling points necessary for the operation of the respective atomizer.
The slave unit (2) is preferably designed such that it constitutes the coupling sleeve of the atomizer changing system.
This means that the wear-sensitive sealing elements are located in the slave unit (2).
In this way, maximum availability of the changeover system can be achieved.
The slave unit (2) preferably has a data carrier (2.7) which can be queried from the master unit (1) at any time.
reading unit (1.7) preferably located on the master unit (1) is used for this purpose.
The data carrier (2.7) can also serve to identify the slave unit (2) connected to the atomizer for storage in or removal from a magazine or a change station.
In addition to the fully automatic changeover of the atomizers and the storage in or from a magazine or a changeover station, however, it is also possible to change the atomizer connected to the slave unit (2) manually on the robot, without a magazine or a changeover station having to be approached.
A practically implemented embodiment of the atomizer change system according to the invention can be seen in
| Number | Date | Country | Kind |
|---|---|---|---|
| 20165481.1 | Mar 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/057812 | 3/25/2021 | WO |
