DE102020129202A1 - Additive manufacturing facility - Google Patents

Abstract

The disclosure relates to a system for additive manufacturing, in particular by means of direct energy deposition, with a working space (18), a housing (16) that delimits the working space (18), at least one application head (46) for dispensing a building material, a handling device ( 24, 324) with a receptacle (40, 340) and an integrated cleaning system (60) with at least one cleaning head (62, 100), the at least one cleaning head (62, 100) being moved by the handling device (24, 324) in the working area (18) is movable in order to clean at least the working space (18) or a component (58). The disclosure also relates to a corresponding method for additive manufacturing.

Description

The present disclosure relates to an additive manufacturing system. At least in exemplary forms, the present disclosure relates to direct energy deposition (DED) additive manufacturing systems.

Such systems and devices include, for example, a handling device with an application head and a workpiece carrier, the handling device being able to move the application head relative to the workpiece carrier in order to apply material to a workpiece or a substrate there.

Additive manufacturing (AM) systems can be used for various use cases. This includes, for example, complete production of components (completely using additive manufacturing), supplementary production of components (additive manufacturing in addition to conventional manufacturing for a component), and/or use for repair purposes (used part is upgraded using additive manufacturing). Another application for additive manufacturing systems is the coating of workpieces. In this way, workpieces with the desired surfaces and properties can be produced by applying a layer to an existing semi-finished product. It is conceivable to coat external surfaces of a workpiece. Furthermore, it is also conceivable to coat inner surfaces, ie surfaces facing inwards. The term additive manufacturing includes the completely additive formation of components, but also an additive order on an already existing component.

The term Direct Energy Deposition (DED) summarizes various processes for additive manufacturing, which are based on the fact that material is melted and applied using a focused energy source, in particular using high-energy radiation. The building material is supplied as powder or wire, for example.

An exemplary representative of DED technologies is laser deposition welding (LMD - Laser Metal Deposition). The energy input takes place with a laser. The laser creates a molten pool on the component surface. Metal powder is automatically introduced through a nozzle. The powder melts and combines with the base material. Beads that are welded together are created, which result in structures on existing base bodies or entire components. If necessary, many layers can be built up one on top of the other. Argon, for example, is used as the protective gas. However, DED methods are also known which process metal wires instead of metal powder.

DED processes can also be used to create 3D structures on uneven surfaces. The process is therefore also suitable for repairs and changes in geometry. Different materials can be used so that components with an inhomogeneous material structure can also be produced. DED processes have relatively high deposition rates compared to other additive manufacturing processes.

From the EP 2 872 287 A2 a device for additive manufacturing is known that uses the DED method. The system includes an application head that can be moved relative to a tool carrier via a handling device. The handling device includes a carrier for the application head, which is also designed to accommodate other heads, for example machining heads for machining.

Systems for additive manufacturing in an industrial environment are expensive. This applies, for example, to systems that can produce metallic workpieces (components) using additive processes. To produce metallic components, it is regularly necessary to at least partially melt or even completely melt the building material so that a sufficiently tight bond is created.

Additive manufacturing is now widespread, especially in the industrial environment. In particular, the processing of metal materials opens up new fields of application. Many current additive manufacturing systems focus on the actual construction process. However, there are other process components, in particular the required cleaning, which lead to an increase in non-productive times.

In additive manufacturing, there is often considerable contamination in the work area. A considerable amount of contamination (e.g. so-called overspray) often cannot be avoided due to the process. This has a negative effect on process times, since time-consuming manual cleaning work is often necessary. In other words, the working space with the component arranged therein must first be sufficiently cleaned before the component is removed after the construction process.

Immediate removal of the component is often only possible with extensive personal protective equipment if the work area and the component have not been cleaned sufficiently. This also has a disadvantageous effect on the application in industry all environment. Components manufactured using AM are often subjected to post-processing, so that any contamination can also have negative effects in the subsequent processing steps.

Excess powder from the construction process, which is deposited in the work area, can even serve as raw material, if necessary after appropriate processing. Even when using a construction material in wire form, there is contamination in the construction space. In general, metal vapors, welding gas and the like can form in the work area during additive manufacturing using DED, which settle on surfaces in the work area, on components of the system, but also on the component. It is therefore often appropriate not only to clean the component, but also its surroundings. It is advisable to clean the working space, including the kinematics arranged there, at least periodically, at least in sections.

Intensive cleaning may be required when changing materials, for example. Then dirt must be removed as far as possible for reasons of sorting.

One advantage of additive manufacturing using DED is the high degree of variability, as material can be applied in a targeted manner. The application head can often be moved in several axes relative to the workpiece in the working area and, if necessary, even pivoted. This freedom of design allows the additive manufacturing (including additive processing, coating and the like) of a large number of different components in one and the same system. However, this has an impact on the resulting pollution picture.

Against this background, the invention is based on the object of specifying a system for additive manufacturing that can be used flexibly and is suitable for applications in the industrial environment. Preferably, the requirement for personal protective equipment can be reduced when removing components after the construction process. Such a system is preferably suitable for automated production. Preferably, the system allows a reduction in non-productive times by reducing the time required for manual cleaning, in particular before component removal. Furthermore, the system should reduce the exposure to contamination (exposure to dust) for an operator as much as possible, at least in exemplary configurations. If possible, the overall operation of the system should be simplified.

• - einen Arbeitsraum,
• - eine Einhausung, die den Arbeitsraum begrenzt,
• - zumindest einen Auftragskopf zum Ausbringen eines Baumaterials,
• - eine Handhabungseinrichtung mit einer Aufnahme, und
• - ein integriertes Reinigungssystem mit zumindest einem Reinigungskopf,

wobei der zumindest eine Reinigungskopf durch die Handhabungseinrichtung im Arbeitsraum bewegbar ist, um zumindest den Arbeitsraum oder ein Bauteil zu reinigen.According to a first aspect of the present disclosure, the object is achieved by a system for additive manufacturing, in particular by means of direct energy deposition, the system having the following:

• - a workroom,
• - an enclosure that delimits the work area,
• - at least one application head for applying a building material,
• - a handling device with a receptacle, and
• - an integrated cleaning system with at least one cleaning head,

wherein the at least one cleaning head can be moved in the work space by the handling device in order to clean at least the work space or a component.

The object of the invention is achieved in this way.

According to the invention, an integrated and automated cleaning is made possible, so that any additional effort for the cleaning, in particular for manual cleaning, is reduced. A separate cleaning device for removing residues from the additive manufacturing process can preferably be dispensed with.

In an exemplary embodiment, the integrated cleaning system enables dirt, residues (powder, overspray,...) to be removed, so that the component (workpiece) can be removed from the work area without additional measures such as increased dust protection. At the very least, the integrated cleaning system simplifies any subsequent process steps and/or parts handling.

In an exemplary embodiment, the system is designed as a self-cleaning system. In an exemplary embodiment, the handling device provides degrees of freedom of movement that enable the system to clean itself, in particular also to clean the component.

In exemplary configurations, the handling device is used primarily to generate a relative movement between the applicator head and the workpiece. Furthermore, in other configurations the primary task of the handling device is a handling task, for example the automated loading (in particular the unloading) of the system. Guiding the cleaning head in the workspace can be referred to as a secondary task, at least in exemplary embodiments. In other words, at least in exemplary embodiments for the Cleaning, in particular exclusively, uses such axes or degrees of freedom of movement that are already present in the system. In such a case, the cleaning function is provided with existing handling devices.

The handling device generally provides movement kinematics. This can involve serial kinematics, for example in the form of a robot (for example articulated-arm robots), in the form of Cartesian kinematics (for example moving column, portal construction, gantry construction). Alternatively, parallel kinematics are conceivable.

In an exemplary embodiment, the system for additive manufacturing is designed to process metal-based or metal-containing building materials, for example by softening or melting. For example, the system is designed to generate thermal energy, in particular in the form of laser beams, with the thermal energy being used to soften and melt the building material supplied. In this way, material can be applied layer by layer.

For example, the system is designed as a DED system (Direct Energy Deposition) or LMD system (Laser Metal Deposition, laser deposition welding). The building material to be processed is provided as powder or wire, for example. It is also conceivable to provide both types of material feed in one plant.

At least in exemplary configurations, it is therefore not a matter of so-called powder bed systems in which—layer by layer—a powder is spread out in layers in a chamber and then partially melted. Instead, DED systems or LMD systems are equipped with an application head that can deliver and apply the building material at specific positions. The application head can usually be moved in several axes relative to the component, so that complex geometries can also be created.

In the case of powder bed-based systems (e.g. selective laser sintering, SLS), the powder layers are regularly layered in special construction chambers (e.g. construction cylinders) in order to produce components. Such a construction chamber regularly has a base area that is completely covered with the powder layer by layer. In this way, however, the powder is already locked in a defined volume when the powder is partially melted and solidified.

In DED systems with an application head, excess powder, overspray and other contamination spread more freely in the work area, so that a larger area can be contaminated overall. It is therefore advantageous if the cleaning head, like the application head, can be moved in the work space relative to the work space or to the component, and in particular can be moved in a relatively large space of movement by the handling device. Local concentrations of pollution can of course arise. However, it must be expected that large areas in the workroom will be at least partially soiled.

According to an exemplary embodiment, the integrated cleaning system is designed to clean the working space and at least one additively produced component that is arranged in the working space at least in sections. In other words, the cleaning system, at least in exemplary configurations, can clean both the component and the area surrounding the component as well as the interior of the working space overall, at least essential sections thereof.

In an exemplary embodiment, the integrated cleaning system enables a degree of cleaning that allows the component to be removed without extensive personal protective equipment. In other words, in exemplary configurations, the integrated cleaning system is able to enable the components to be removed in a normal atmosphere. In this way, the manufacturing costs of AM-based manufacturing can be reduced, at least in exemplary configurations.

According to a further exemplary embodiment, the handling device has a receptacle for receiving the at least one cleaning head. This can include a configuration in which the receptacle is designed both to accommodate the at least one application head and to accommodate the at least one cleaning head. The cleaning head and the applicator head are usually not attached to the receptacle simultaneously but one after the other. In this way, the handling device can (possibly one after the other) carry an application head and a cleaning head and move them in the working space. According to a further exemplary embodiment, the handling device has a carrier with an interface to which the applicator head and the cleaning head (suction head) can be attached. In an exemplary embodiment, the applicator head and the cleaning head use at least partially the same fastening elements for fastening to the receptacle of the handling device.

According to a further exemplary embodiment, the at least one cleaning head of the cleaning system can be moved by the handling device for cleaning purposes. In other words, the handling device can also be used for cleaning purposes. This allows designs in which the handling devices required for the construction process can also be used for cleaning.

According to a further exemplary embodiment, the handling device is designed to receive and move the at least one application head. Accordingly, the cleaning device is also provided for the actual application of material as part of additive manufacturing. Essential embodiments according to the disclosure use the handling device both for moving the applicator head and for moving the cleaning head. In this way, axes of movement (degrees of freedom of movement) already present in the system, which are necessary for the more or less complex construction task, can also be used for cleaning. This ensures that the cleaning head can be moved in a similar manner and with similar degrees of freedom of movement as the applicator head. This can contribute to increasing the cleaning performance.

According to an exemplary embodiment, the handling device is a main kinematic system of the system that generates relative movements between the application head and the workpiece or workpiece carrier during additive manufacturing or processing, so that building material can be applied at the desired position and in the desired orientation. According to an exemplary embodiment, one and the same movement kinematics can be used for the application head and the cleaning head.

According to an exemplary embodiment, the movement kinematics can be operated in a head change mode in order to make a change between the application head and the cleaning head. In this way, an automated change between the application head and the cleaning head can take place. Cleaning can be integrated even more flexibly into the additive manufacturing task.

According to a further alternative embodiment, the handling device is an auxiliary kinematic system. A secondary kinematics is provided in addition to a main kinematics. For example, they can be handling devices for changing workpieces, changing heads, measurements or the like, which can also be used for cleaning purposes.

According to a further exemplary embodiment, the handling device can be used in a construction mode and a cleaning mode of the system. In the construction mode, the handling device carries the at least one application head. In the cleaning mode, the handling device carries the at least one cleaning head.

According to this embodiment, the handling device is used both for the actual construction and for cleaning the system. In other words, additive manufacturing and cleaning take place sequentially if the handling device is used for both purposes. This includes cleaning the workspace and/or the workpiece after the additive manufacturing task has been completed. However, it is also conceivable to interrupt additive manufacturing in sections in order to carry out cleaning in between.

According to a further exemplary embodiment, the handling device has linear kinematics with Cartesian axes. Such a handling device is designed, for example, according to the traveling column principle, portal principle, gantry principle or in a similar way. It goes without saying that both the construction process and the cleaning process depend on relative movements between the respective head (application head and cleaning head) and the component or the working space. Designs are therefore also conceivable in which at least one axis of movement is provided directly on the component or its receptacle. This is not to be understood as limiting.

According to a further exemplary embodiment, the handling device comprises a robot, in particular an articulated arm robot. In the industrial environment, such robots are also referred to as industrial robots, universal robots or articulated robots. In an exemplary embodiment, the robot is designed as a robot with serial kinematics. Individual joints of the robot are arranged one after the other (in a row), are connected to their neighbors in an articulated manner and can each be moved, usually pivoted, relative to one another. In this way, an end effector (also referred to as a “hand”) can be moved, in particular freely moved, in a movement space defined by the kinematics. The “hand” of the robot carries the holder for the application head and/or cleaning head, for example.

The use of a robot as part of the handling device, preferably as an essential part of the handling device for the or the application heads, has the advantage that the parking positions of individual application heads within the given movement space of the robot can be selected. Thus, the parking positions can be spaced apart.

In an exemplary embodiment, the robot is arranged in the work space and can only be moved within the work space. In this way, the robot is enclosed by the enclosure of the work area when it is used productively. This also reduces any contamination from the system entering the environment. Safety is also increased since the robot is shielded by the housing during its productive use.

Serial kinematics also includes, for example, portal robots, horizontal articulated-arm robots (SCARA robots), articulated-arm robots with 5, 6 or 7 rotational axes and the like. It goes without saying that robots can also have parallel kinematics, for example as so-called delta robots or hexapod robots. Mixed forms are easily conceivable.

The positioning accuracy and repeatability that the robot provides is sufficient for additive manufacturing purposes. In other words, the robot can be used for the fine positioning and the feed movement of the applicator head and the cleaning head.

According to a further exemplary embodiment, the handling device is capable of moving the cleaning head to any desired position in the workspace in order to clean the workspace and components arranged therein. It is therefore advantageous to use a handling device with great freedom of movement and a large area of movement, such as an articulated-arm robot or articulated-arm robot.

According to a further exemplary embodiment, the at least one cleaning head is a suction head that can be moved in the work area. In other words, the cleaning system according to this embodiment represents a suction device for sucking off residues from the working area. In this way, a large part of the dirt can be removed in an orderly manner and caught in a targeted manner.

In an exemplary application for additive manufacturing based on the DED principle, a so-called overspray of around 20-40% of the building material is created. This is not to be understood as limiting. Excess material must be removed in order to remove the component without additional protective measures and to be able to feed possible further processing steps. In other words, excess powder can be sucked up and collected in a targeted manner.

Furthermore, additional contamination regularly occurs in the work area, such as spatter ("weld beads") during build-up welding, slag, other combustion residues, foreign matter and more. This contamination can also be removed and collected to a large extent by suction.

It goes without saying that configurations with several cleaning heads are also conceivable. This can relate to a plurality of suction heads which differ from one another, for example with regard to their nozzle design.

According to a further alternative embodiment, at least one further cleaning head is provided, which is designed for mechanical cleaning, in particular as a brush head. A brush head is provided with a brush, for example (round brush, flat brush or the like). The brush head can be provided with a drive for the brush in order to loosen adhering dirt. However, it is also conceivable that the brush head is alternatively or additionally moved by the handling device in order to loosen adhering dirt.

It goes without saying that, in principle, a combined brush and suction head can also be provided, which on the one hand loosens adhering material and sucks it off using the integrated suction function.

According to a further exemplary embodiment, the brush head interacts with the suction device in order to remove residues and guide them out of the work area in a directed manner.

According to another exemplary embodiment, the system is designed exclusively as an AM system (system for additive manufacturing). In other words, exemplary configurations are conceivable in which no subtractive post-processing takes place in the installation space itself. Such post-processing can be done on downstream machines if necessary. Cycle times on machines for subtractive post-processing are often shorter than cycle times on machines for additive machining. Therefore, overall lead time and manufacturing effort can be optimized by combining AM systems with separate machine tools for subtractive (machining) machining, at least in exemplary embodiments.

According to a further exemplary embodiment, there are two or more holders in the working area for receiving the at least one application head and the at least one cleaning head, which provide at least two parking positions. In this way, the handling device can first deposit a head and then pick up the new head. It goes without saying that combined holders with two mounting locations are also conceivable. If both the at least one application head and the at least one suction head are arranged in the working space, the transfer of dirt (powder and the like) to the environment is further reduced.

According to a further exemplary embodiment, at least one holder with a shelf for the applicator head and at least one holder with a shelf for the cleaning head are provided. According to this embodiment, the applicator head is held on its holder when the cleaning head is attached to the holder of the handling unit. The cleaning head is received on its holder when the applicator head is attached to the receptacle of the handling unit.

According to a further exemplary embodiment, the at least one application head is coupled to at least one supply line, the at least one cleaning head being coupled to at least one suction line, and the lines in particular also remaining coupled when the application head or the cleaning head is parked. In this way, contamination of the pipes (the inside of the pipes) is avoided. Furthermore, this design allows a quick change between application heads and cleaning heads, since the effort for the coupling and decoupling of lines is eliminated, at least for some lines

According to a further exemplary embodiment, the system also includes a control unit for controlling the cleaning system, with the control unit controlling the handling device during a cleaning mode in order to move the cleaning head relative to the workspace. The control unit can be part of a control device of the system. In an exemplary embodiment, the control unit is also capable of controlling the handling device during a construction mode in order to move the application head relative to the workspace or relative to the component. The movement usually takes place in the installation space.

According to a further exemplary embodiment, the control unit is designed to initiate self-cleaning of the system, in particular of the working space with the component, following a construction process. In this way, after the additive application, cleaning takes place, which can simplify the removal and subsequent handling of the component.

According to a further exemplary embodiment, the control unit is designed to cause intermittent intermediate cleaning of the working space and/or the component during the construction process, with the control unit preferably being designed to initiate intermediate cleaning when the construction process provides for a rest phase, in particular a cooling phase . In this way, cleaning can already take place during the construction process, so that the overall contamination is reduced. In an additive construction process, cooling cycles are often provided anyway, so that in exemplary configurations the cycle time does not increase excessively despite intermediate cleaning. This is not to be understood as limiting. The intermediate cleaning can be carried out periodically or as required. Construction phases and cleaning phases can alternate.

According to a further exemplary embodiment, the control unit is designed to initiate cleaning as a function of the degree of soiling. For example, the control unit is designed to initiate a cleaning process when certain parameters for the construction quality and the resulting workpiece properties are exceeded or there is a risk of them being exceeded.

According to a further exemplary embodiment, the system also has a sensor unit with at least one contamination sensor, preferably an optical contamination sensor. In this way, the cleaning process can be initiated depending on the detected degree of contamination or a detected degree of coverage.

According to a further exemplary embodiment, the contamination sensor is designed to optically detect a degree of coverage of a surface of the working space. In this way, the efficiency of the cleaning can be further increased.

According to a further exemplary embodiment, the contamination sensor is coupled to a light source. The light source can be, for example, an illuminant for planar illumination or a laser light source. It is conceivable that the light source is used for essentially homogeneous illumination of the working space. It is also conceivable to provide the light source to project a pattern onto surfaces in the working space or onto the component in order to use the contamination sensor to detect the degree of contamination/coverage on this basis.

According to an exemplary embodiment, the light source is designed as a flash light source, with the degree of coverage depending on a resulting reflection behavior of the surface is determined.

According to a further exemplary embodiment, the working space has at least one guide element (for example guide plate). The guide element can be, for example, a cover or cladding. Furthermore, guide elements can be used to direct accumulating particles in a targeted manner to areas that are easily accessible for the cleaning system with the at least one cleaning head. For example, in the floor area of the working space, guide plates that are positioned at an angle (inclined relative to the horizontal) are provided as guide elements. In this way, otherwise horizontally oriented surfaces can be at least partially covered with surfaces inclined relative to the horizontal, so that particles are specifically discharged downwards and in particular into an area and concentrated there that is easily accessible for the cleaning head. In a similar way, guide elements for the handling device and other installations in the working area can also be at least partially covered with guide elements in order to improve the removal of particles/dust.

According to a further exemplary embodiment, the guide plate has at least one pocket or trough for catching residues. In other words, a sink for powder and other particles can be provided in which dirt collects. This simplifies cleaning.

According to a further exemplary embodiment, the housing of the working area is designed to be at least dust-tight, preferably gas-tight. According to an exemplary embodiment, this means tightness within the usual limits for protective gas atmospheres. Accordingly, absolute tightness is not absolutely necessary. At the same time, with a sufficiently tight housing, the transfer of dirt into the environment of the system can be effectively reduced. In this way, the concentration of any particles in the vicinity of the plant can be reduced. This means that the system can be operated in normal production environments if necessary, ideally without specific personal protective equipment (especially with regard to dust exposure) for operators in the vicinity of the system.

According to a further exemplary embodiment, the housing is accessible via a door, with a door control being provided which releases the door for opening after production has taken place, if a desired degree of cleaning has been achieved. The door control can be accomplished by the control unit. Ideally, the door control only releases the door if, with the door open and any loading or set-up work, only a small amount of particles can be released from the work area into the environment.

According to a further exemplary embodiment, the handling device is designed to carry out self-cleaning with the cleaning head that is accommodated. In other words, for example a robot as part of the handling device can clean itself at least in sections, in particular at least in essential areas. The self-cleaning of the handling device is facilitated if the handling device has several degrees of freedom of movement and corresponding movement axes with a sufficiently large range of movement.

According to a further exemplary embodiment, the system also has a recovery unit for recovering reusable building material from a gas-particle mixture that has been extracted. The integrated cleaning system allows excess powder or other building material to be picked up in a targeted and sufficiently homogeneous manner. In this way, the outlay for reprocessing can be reduced, at least in exemplary configurations. Furthermore, the integrated cleaning system allows the direct intake and processing of larger quantities if a high cleaning quality is already achieved in the work area.

• - Bereitstellung einer Anlage zur additiven Fertigung, insbesondere einer Anlage nach einer der hierin beschriebenen Ausgestaltungen, wobei die Anlage Folgendes aufweist:
  • - einen Arbeitsraum,
  • - eine Einhausung, die den Arbeitsraum begrenzt,
  • - zumindest einen Auftragskopf zum Ausbringen eines Baumaterials,
  • - eine Handhabungseinrichtung mit einer Aufnahme, und
  • - ein integriertes Reinigungssystem mit zumindest einem Reinigungskopf, wobei der zumindest eine Reinigungskopf durch die Handhabungseinrichtung im Arbeitsraum bewegbar ist, um zumindest den Arbeitsraum oder ein Bauteil zu reinigen,
• - Betreiben der Anlage in einem Baumodus, wobei der zumindest eine Auftragskopf durch die Handhabungseinrichtung verfahren wird, zur Erzeugung eines additiven Auftrags auf ein Bauteil, und
• - Betreiben der Anlage in einem Reinigungsmodus, wobei der zumindest eine Reinigungskopf durch die Handhabungseinrichtung verfahren wird, um zumindest den Arbeitsraum oder ein Bauteil zu reinigen.

According to a further aspect, the present disclosure relates to a method for additive manufacturing, in particular by means of direct energy deposition, with the following steps:

• - Provision of a system for additive manufacturing, in particular a system according to one of the configurations described herein, the system having the following:
  • - a workroom,
  • - an enclosure that delimits the work area,
  • - at least one application head for applying a building material,
  • - a handling device with a receptacle, and
  • - an integrated cleaning system with at least one cleaning head, wherein the at least one cleaning head can be moved in the work space by the handling device in order to clean at least the work space or a component,
• - Operating the system in a construction mode, with the at least one application head being moved by the handling device in order to generate an additive order on a component, and
• - Operating the system in a cleaning mode, wherein the at least one cleaning head is moved by the handling device in order to clean at least the workspace or a component.

In this way, too, the object of the disclosure is completely solved. It goes without saying that the method according to the disclosure can be developed analogously to the system according to the disclosure. This applies, for example, to the various functions of the control unit.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present disclosure.

• 1: eine schematische Ansicht einer Ausgestaltung einer Anlage zur additiven Fertigung mit einem integrierten Reinigungssystem, in einem Baumodus;
• 2: eine weitere Ansicht einer gegenüber der Gestaltung gemäß 1 abgewandelten Anlage, in einem Reinigungsmodus;
• 3: eine weitere schematische Ansicht auf Basis der anhand der 1 und 2 veranschaulichten Anlagen zur Veranschaulichung der Funktionalität einer weiteren Ausgestaltung eines integrierten Reinigungssystems;
• 4: eine weitere Ansicht auf Basis von 3, mit veränderter Position der Handhabungseinrichtung;
• 5: eine weitere Ansicht auf Basis der 3 und 4, mit veränderter Position der Handhabungseinrichtung;
• 6: eine weitere schematische Ansicht einer beispielhaften Ausgestaltung einer Anlage zur additiven Fertigung mit einem integrierten Reinigungssystem;
• 7: eine weitere schematische Ansicht einer beispielhaften Ausgestaltung einer Anlage zur additiven Fertigung mit einem integrierten Reinigungssystem;
• 8: ein Flussdiagramm zur Veranschaulichung einer Ausgestaltung eines Verfahrens zur additiven Fertigung von Werkstücken; und
• 9: ein Flussdiagramm zur Veranschaulichung einer weiteren Ausgestaltung eines Verfahrens zur additiven Fertigung von Werkstücken.

Further features and advantages of the invention result from the following description and explanation of several exemplary embodiments with reference to the drawings. Show it:

• 1 1: a schematic view of an embodiment of a system for additive manufacturing with an integrated cleaning system, in a construction mode;
• 2 : another view of an opposite design according to 1 modified plant, in a cleaning mode;
• 3 : another schematic view based on the 1 and 2 illustrated systems to illustrate the functionality of a further embodiment of an integrated cleaning system;
• 4 : another view based on 3 , with changed position of handling device;
• 5 : another view based on the 3 and 4 , with changed position of handling device;
• 6 1: a further schematic view of an exemplary embodiment of a system for additive manufacturing with an integrated cleaning system;
• 7 1: a further schematic view of an exemplary embodiment of a system for additive manufacturing with an integrated cleaning system;
• 8th : a flowchart to illustrate an embodiment of a method for the additive manufacturing of workpieces; and
• 9 : a flowchart to illustrate a further embodiment of a method for the additive manufacturing of workpieces.

1 10 illustrates an exemplary embodiment of a system for additive manufacturing, which is denoted overall by 10, on the basis of a greatly simplified schematic representation. the 2-7 illustrate other states and exemplary configurations of such systems. In the 1-7 Identical (at least functionally identical) elements and units are denoted by identical reference symbols. Individual aspects and configurations of the 1-7 Illustrated embodiments may be incorporated into or combined with other configurations. To avoid repetition, in particular in connection with the 2-7 differences, modifications and/or additions compared to the above-mentioned embodiments are primarily discussed.

Appendix 10 according to 1 is designed in particular as a DED system. Annex 10 according to is an example 1 trained for additive manufacturing using laser deposition welding (also referred to as LMD). In particular, the system 10 is designed for additive manufacturing (also including the repair, coating and similar additive processes) of components with metal materials. In the DED process or the LMD process, the building material is usually supplied in powder or wire form.

In the exemplary embodiment, the system 10 has a frame 12 which has a base 14 . The base 14 can, for example, also be formed by the floor of a workshop. Furthermore, the system 10 includes a housing 16 which, for example, forms lateral walls. The enclosure 16 may also include an upper wall (ceiling) and optionally also a lower wall (floor). The frame 12 and in particular the housing 16 define a working space 18. The working space 18 is preferably sufficiently sealed off from the environment, preferably designed to be sufficiently dust-tight.

In the embodiment according to 1 a door 20 is also formed in the housing 16, through which the working space 18 is accessible. The door 20 can be opened and closed, for example, for loading processes, handling processes and the like eat. It goes without saying that the door 20 also adequately seals the working space 18 in the closed state, and in particular can seal the working space 18 in a dust-tight manner.

A handling device 24 is arranged in the working area 18 and, in the exemplary embodiment, comprises a robot 26 which is designed as an articulated-arm robot or articulated-arm robot. By way of example, the robot 26 includes a pedestal 30 disposed on the base 14 . Starting from the base 30, elements 32, 34, 36 connect, which can also be referred to as links in the kinematic chain of the robot 26. In the exemplary embodiment, the robot 26 has serial kinematics. The elements 32, 34, 36 are each connected to their neighbors via joints and are movable relative to one another. In this way, the robot 26 has a range of motion that can be reached by an end effector of the robot 26 . The robot 26 has a large number of degrees of freedom of movement.

In the exemplary embodiment according to FIG 1 a recording 40 which carries an application head 46 for additive manufacturing. For example, a supply line 48 is coupled to the application head 46, which in 1 is only indicated schematically and interrupted. The application head 46 can be supplied with the building material (powder or wire), process fluid (for example protective gas), energy and/or control signals via the supply line 48 . The supply line 48 can also be used to provide high-energy radiation (for example laser radiation).

A workpiece holder in the form of a workpiece table 56 is also arranged on the base 14 in the working space 18 . The workpiece carrier or workpiece table 56 carries a component 58 which is additively manufactured with the system 10, at least additively processed/coated. The handling device 24 can move the applicator head 46 in a desired manner in order to apply and solidify building material in a targeted manner. In this way, the component 58 can be additively manufactured, coated and/or repaired.

The system 10 also has an integrated cleaning system 60 . The cleaning system 60 comprises at least one cleaning head 62. The cleaning head 62 is designed as a suction head, for example, and is provided with at least one nozzle 64. The cleaning head 62 is connected to a line 66, in particular a suction line. In working space 18, a line guide 68 is provided, for example, which 1 is only indicated schematically. In the exemplary embodiment, the line 66 is connected to a recovery unit 70 which includes a filter 72 for recovering the building material. This is not to be understood as limiting.

The handling device 24 is designed to carry both the application head 46 and the cleaning head 62 and to be able to move in the working space 18 . In other words, the handling device 24 can on the one hand additively manufacture the component 58 and on the other hand can clean the working space 18 and the component 58 . For this purpose, the receptacle 40 of the handling device 24 is designed to carry the cleaning head 62 or the application head 46 as required. This way is in the in 1 shown embodiment no additional handling device 24 for cleaning with the cleaning head 62 is required.

In 1 is also denoted by 76 a sensor unit. In the exemplary embodiment, the sensor unit 76 comprises a contamination sensor 80 which is designed in particular as an optical sensor 82 . in the in 1 A light source 84 is also assigned to the sensor unit 76 shown in the embodiment shown. The sensor unit 76 is designed to determine a degree of contamination or a degree of coverage of the working space 18 or of the component 58 . The light source 84 can contribute to creating favorable lighting conditions for determining the degree of soiling. However, it is also conceivable to use the light source 84 to project certain patterns onto surfaces in the working space or on the component 58 . This can simplify the determination of the degree of contamination. Alternatively, the light source 84 is designed as a flash light source. A powder concentration or dust concentration can also be determined in this way.

In an exemplary embodiment, the sensor unit 76 is designed to determine a particle concentration in the atmosphere in the working space 18, for example by means of photometric dust measurement. It is also conceivable to upgrade the sensor unit 76 both to detect a degree of coverage (of surfaces) and to detect a particle concentration/dust concentration in the working space 18 .

The system 10 also has a 1 control unit 90 shown only symbolically. The control unit 90 can be designed as part of a higher-level control device or as a discrete unit. The control unit 90 is designed to operate the system 10 in a construction mode and, if necessary, in a cleaning mode. In the construction mode, the handling device 24 carries the applicator head 46. In the cleaning mode, the handling device 24 carries the cleaning head 62. In this way, one and the the same handling device 24, in particular one and the same robot 26, can be used either for the construction process or for cleaning.

The handling device 24 with its receptacle 40 at the end is designed to selectively grip and carry at least one cleaning head 62 or at least one application head 46 . In other words, there is an active and an inactive state for both the cleaning head 62 and the application head 46 . The inactive state can also be referred to as a parking position. The system 10 has in the embodiment according to 1 a holder 94 and a holder 96 on. The holder 94 is designed as a receptacle for the cleaning head 62, for example. The holder 96 is designed, for example, as a receptacle for the application head 46, see also 2 . It goes without saying that the holders 94, 96 can be designed both to accommodate an application head 46 and to accommodate a cleaning head 62, at least in exemplary configurations.

In 1 Plant 10 is in construction mode. In 2 the system 110 there is in cleaning mode. The change from construction mode to cleaning mode includes, for example, a delivery of the application head 46 to the holder 96 and a pickup of the cleaning head 62 from the holder 94. The change from cleaning mode to the construction mode includes, for example, a delivery of the cleaning head 62 to the holder 94 and a pickup of the application head 46 from holder 96.

In an exemplary embodiment, line 66 of cleaning head 62 remains connected to cleaning head 62 even when system 10 is in build mode. In an exemplary embodiment, the line 48 of the application head 46 also remains connected to the application head 46 when the system 10 is in the cleaning mode. This further simplifies the switch between building mode and cleaning mode. The number of interfaces to be operated is reduced.

Cleaning of the working space 18 or of the component 58 can be initiated by the control unit 90 as a function of a contamination signal which the sensor unit 76 provides. It is conceivable to operate the system 10 in such a way that the control unit 90 initiates cleaning as required, ie when there is a certain degree of soiling. However, it is also conceivable to operate the system 10 in such a way that the control unit 90 initiates cleaning at intervals. For example, cooling breaks and similar process-related interruptions in the construction process can be used for such periodic cleaning. It goes without saying that a combination of periodic and need-based cleaning can also be used. In principle, it is also conceivable to complete the construction process and then to clean the working space 18 and the component 58 before removing the component 58 .

In an exemplary embodiment, the control unit 90 is designed to pursue a compromise between the shortest possible cycle time and high component quality (as well as less contamination). In an exemplary embodiment, the cleaning with the integrated cleaning system 60 takes place in such a way that the component 58 can be removed, transferred and, if necessary, further processed without special protective clothing for dusty environments. It is advantageous if the component 58 can be removed in an at least sufficiently cleaned state. In this way, the system 10 can be easily integrated into existing production environments.

The control unit 90 can also include a door controller. For example, the control unit 90 is designed to release the door 20 only when the integrated cleaning system 60 has reached a desired degree of cleaning. This can be the case, for example, when the working space 18 has been sufficiently cleaned so that the component 58 can be removed without special protective measures.

2 Figure 10 illustrates an embodiment of a system, designated 110, which is the system 10 in accordance with 1 is designed similarly. The plant 110 in 2 is in the cleaning mode, whereas the system 10 is in accordance with FIG 1 in build mode. In 1 the cleaning head 62 is in a parking position at the holder 94. In 2 the application head 46 is in a parking position at the holder 96.

In the cleaning mode, the handling device 24 carries the cleaning head 62 in order to remove powder residues, dust and the like from the component 58 or from the working space 18 . For this purpose, the handling device 24 uses the degrees of freedom of movement provided anyway for the construction process. In this way, the cleaning head 62 can be moved with great freedom of movement in the working space 18 in order to clean it at least in sections.

2 further illustrates that the system 110 may include additional cleaning heads. For example, in addition to the cleaning head 62 designed as a suction head, a further cleaning head 100 is provided, which is designed as a brush head. The cleaning head 100 has a brush 102 . The brush can be ver with its own drive be seen The brush 102 is used for mechanical cleaning or for loosening deposits. The cleaning head 100 can also optionally be provided with a line 104 . The line 104 can be designed as a suction line. In this way, the cleaning head 100 can both brush and vacuum simultaneously to remove loosened debris. However, this is not to be understood as limiting.

In an exemplary embodiment, the control unit 90 is designed such that in the cleaning mode, loose particles are first removed with the cleaning head 62 designed as a suction head, and then the cleaning head 100 designed as a brush head is used to loosen any deposits that are still adhering. These can then be vacuumed off. Other cleaning modes are conceivable. The in the 1-7 The systems illustrated can in principle also be equipped with a plurality of application heads 46, which are held by the handling device 24 as required and used in construction mode.

the 3-5 illustrate a further embodiment of a designated 210 system, the systems 10, 110 according to the 1 and 2 is basically similar. Guide elements 220 , 222 are arranged in the respective working space 18 and cover certain sections of the working space 18 . The guide elements 220, 222 are, for example, guide plates, panels and the like. In the 3-5 the guide elements 220, 222 are inclined relative to the horizontal. In this way, a targeted powder guidance (supported by gravity) can be effected. In the exemplary embodiment, the guide elements 220, 222 open into a depression 224 in which powder and other dirt collect. It goes without saying that further/other guide elements can be provided in order to cover poorly accessible areas in the working space 18 . This simplifies cleaning with the integrated cleaning system 60.

3 12 illustrates that the handler 24 can position and orient the cleaning head 62 with the nozzle 64 such that powder and other debris can be vacuumed or otherwise removed from the sink 224 . 4 illustrates that the handling device 24 can position and align the cleaning head 62 with the nozzle 64 in such a way that powder and other dirt can be sucked off from the component 58 or from the area surrounding the component 58 from walls and other surfaces of the workspace 18 or can be removed in some other way, for example in the vicinity of the door 20. In an exemplary embodiment, the movement space of the handling device 24 is adapted to the dimensions of the working space 18 in such a way that the inner surfaces of the housing 16 can be cleaned at least in sections.

5 illustrates that, according to an exemplary embodiment of the cleaning system 60 , self-cleaning or self-cleaning of the handling device 24 is made possible. For example, the robot 26 (cf 1 ) of the handling device 24 are operated in such a way that essential sections of the kinematics of the robot 26 can be cleaned with the cleaning head 62 accommodated on the holder 40 .

6 FIG. 12 illustrates another exemplary embodiment of an additive manufacturing system, designated 310 . The system 310 is modified compared to the systems 10, 110, 210 in that separate handling devices 24, 324 for the application head 46 and the cleaning head 62 are provided there. In the exemplary embodiment, two handling devices 24, 324 are provided, each of which is designed as a robotic handling device 24, 324, for example.

The handling device 24--as previously described--serves as the main kinematics 328. The handling device 24 carries the application head 46. The handling device 324, on the other hand, serves as the secondary kinematics 330 and carries the cleaning head 62. The handling device 324 is designed as a robot 326, for example. The robot 326 comprises a base 340 and elements 342, 344, 346 which serve as links in the kinematic chain of the robot 326. Similar to the robot 26 ( 1 ) the robot 326 is also designed as an articulated arm robot or swivel arm robot. At its end on the effector side, the robot 326 has a receptacle 340 for receiving the cleaning head 62.

6 further illustrates a workpiece gripper 348 which is arranged on a holder 350 in the work space 18 . The workpiece gripper 348 is designed, for example, as a pneumatic gripper with a corresponding supply line. In an exemplary embodiment, the handling device 324 serving as the secondary kinematics 330 is designed to carry the workpiece gripper 348 or the cleaning head 62 alternately and to move it in the working space 18 . In the exemplary embodiment, the holder 350 is the holder 94 or the holder 96 (also compare 2 ) designed to be comparable, but this is not to be understood as limiting. The secondary kinematics 330 can thus also be used in several modes, in a loading mode with the workpiece gripper 348 and, for example, in a cleaning mode with the cleaning head 62. Also in this embodiment no additional handling equipment is required in cleaning mode.

Also at the in 6 In the illustrated configuration of the system 310, the construction mode and the cleaning mode can follow one another sequentially and can be repeated several times. However, it is also conceivable to design the control unit 90 in such a way that the construction mode and cleaning mode overlap at least temporarily. In this way, the cycle time can be further reduced.

7 FIG. 12 illustrates another exemplary embodiment of an additive manufacturing system, designated 410 . Annex 410 differs in this respect from the previous ones in connection with the 1-6 Illustrated plants 10, 110, 210, 310 than that the handling unit 24 has no robot, but a linear kinematics 430, which is designed, for example, as Cartesian kinematics. In other words, the kinematics 430 are designed as XYZ kinematics, ie with three movement axes perpendicular to one another.

7 illustrates two mutually perpendicular movement axes. A first axis with a horizontal orientation is defined by a horizontal guide 432 and a carriage 434 mounted thereon. A second axis of vertical orientation is defined by a vertical guide 436 and a carriage 438 . In the exemplary embodiment, the vertical guide 436 sits on the carriage 434 and is moved along the horizontal guide 432 together with it. The kinematics 430 is designed as a traveling column kinematics, for example. However, this is not to be understood as limiting. It goes without saying that a third axis with a corresponding guide and carriage can also be provided, which is exemplified in the in 7 selected orientation perpendicular to the view plane. Furthermore, pivot axes, rotation axes and the like can be provided which are parallel to the aforementioned axes.

With a handling device 24 provided with Cartesian kinematics 430 , the application head 46 can be held in a construction mode and the cleaning head 62 can be held in a cleaning mode and moved relative to the working space 18 or to the component 58 .

8th uses a schematic flowchart to illustrate an exemplary embodiment of a method for additive manufacturing, in particular using DED. The method includes a step S10, which includes the provision of a system, in particular a system according to at least one embodiment described herein. In a subsequent step S12, the system is operated in a construction mode in order to additively manufacture, coat and/or repair a component. The additive manufacturing preferably includes the application and solidification of a metal-based or metal-containing building material. This includes, for example, steel materials, aluminum materials, titanium materials, Ni-based materials and alloys containing them.

In a further step S14, the system is operated in a cleaning mode, in particular an integrated cleaning mode. One and the same handling device is preferably used both in the cleaning mode and in the construction mode, in order to hold an application head on the one hand and a cleaning head on the other hand and to move them in a working space of the system. For example, the cleaning takes place to a degree that, in a further step S16, allows the component to be removed and processed further without special personal protective equipment.

9 uses a schematic flow chart to illustrate a further exemplary embodiment of a method for additive manufacturing, in particular by means of DED. The method includes a step S20, which includes the provision of a system, in particular a system according to at least one embodiment described herein.

A step S22 follows, which includes a combined construction process. Step S22 includes sub-steps S24, S26, which are run through once or several times in succession. The sub-step S24 relates to a build mode. The sub-step S26 relates to a cleaning mode. The partial steps S24, S26 can be run through alternately, so that cleaning occurs intermittently during the construction process.

In an exemplary embodiment, cooling pauses and similar process-related pauses in the construction process are used for the intermediate cleaning steps S26. After completion of the construction process S22 and sufficient cleaning, the component can be removed in a subsequent step S28, preferably without the need for extensive personal protective equipment. The component can preferably be removed and fed to further production steps without specific, earmarked protective equipment, which entails the corresponding effort during use and costs.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2872287 A2 [0007]

Claims (20)

System for additive manufacturing, in particular by means of Direct Energy Deposition, which has the following: - a workroom (18), - a housing (16) which delimits the working space (18), - at least one applicator head (46) for applying a building material, - A handling device (24, 324) with a receptacle (40, 340), and - an integrated cleaning system (60) with at least one cleaning head (62, 100), wherein the at least one cleaning head (62, 100) can be moved in the working space (18) by the handling device (24, 324) in order to clean at least the working space (18) or to clean a component (58). plant after claim 1 , wherein the integrated cleaning system (60) is designed to clean the working space (18) and at least one additively produced component (58) arranged at least in sections in the working space (18). plant after claim 1 or 2 , wherein the handling device (24, 324) has a receptacle (40, 340) for receiving the at least one cleaning head (62, 100) and preferably the at least one application head (46). Plant after one of Claims 1 - 3 , wherein the handling device (24, 324) is a secondary kinematic system (330). Plant after one of Claims 1 - 4 , wherein the handling device (24, 324) can be used in a construction mode and a cleaning mode of the system. Plant after one of Claims 1 - 5 , wherein the handling device (24, 324) has a linear kinematics (430) with Cartesian axes. Plant after one of Claims 1 - 5 , wherein the handling device (24, 324) comprises a robot (26, 326), in particular an articulated arm robot. Plant after one of Claims 1 - 7 , wherein the at least one cleaning head (62, 100) is a suction head which can be moved in the working space (18). Plant after one of Claims 1 - 8th , wherein at least one further cleaning head (62, 100) is provided, which is designed for mechanical cleaning, in particular as a brush head. Plant after one of Claims 1 - 9 , wherein two or more holders (94, 96, 106) for receiving the at least one application head (46) and the at least one cleaning head (62, 100) are provided in the working space (18), which provide at least two parking positions. Plant after one of Claims 1 - 10 , wherein the at least one application head (46) is coupled to at least one supply line (48), wherein the at least one cleaning head (62, 100) is coupled to at least one suction line (66, 104), and wherein the lines (48, 66, 104) in particular also remain coupled in a respective parking position of the application head (46) or the cleaning head (62, 100). Plant after one of Claims 1 - 11 , further comprising a control unit (90) for controlling the cleaning system (60), wherein the control unit (90) controls the handling device (24, 324) during a cleaning mode in order to move the cleaning head (62, 100) relative to the workspace (18). . plant after claim 12 , wherein the control unit (90) is designed to initiate a self-cleaning of the system, in particular of the working space (18) with the component (58), following a construction process. plant after claim 12 or 13 , wherein the control unit (90) is designed to cause intermittent intermediate cleaning of the working space (18) and/or the component (58) during the construction process, and wherein the control unit (90) is preferably designed to initiate intermediate cleaning if the construction process provides for a rest phase, in particular a cooling-off phase. Plant after one of Claims 12 - 14 , wherein the control unit (90) is designed to initiate cleaning depending on the degree of contamination. Plant after one of Claims 1 - 15 , further comprising a sensor unit (76) with at least one contamination sensor (80), preferably an optical contamination sensor (82). plant after Claim 16 , wherein the contamination sensor (80) is designed to optically detect a degree of coverage of a surface of the working space (18). plant after Claim 16 or 17 , wherein the contamination sensor (80) is coupled to a light source (84). Plant after one of Claims 1 - 18 , further comprising a recovery unit (70) for the recovery of reusable building material from an extracted gas-particle mixture. Process for additive manufacturing, in particular by means of direct energy deposition, with the following steps: - Provision of a system (10, 110, 210, 310, 410) for additive manufacturing, in particular a system (10, 110, 210, 310, 410) according to one of the preceding claims, wherein the system (10, 110, 210, 310 , 410) has: - a workroom (18), - a housing (16) which delimits the working space (18), - at least one applicator head (46) for applying a building material, - A handling device (24, 324) with a receptacle (40, 340), and - an integrated cleaning system (60) with at least one cleaning head (62, 100), wherein the at least one cleaning head (62, 100) can be moved in the working space (18) by the handling device (24, 324) in order to clean at least the working space (18) or to clean a component (58), - Operating the system (10, 110, 210, 310, 410) in a construction mode, wherein the at least one application head (46) is moved by the handling device (24, 324) to generate an additive order on a component (58), and - Operating the system (10, 110, 210, 310, 410) in a cleaning mode, with the at least one cleaning head (62, 100) being moved by the handling device (24, 324) around at least the workspace (18) or a component (58) to clean.

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