Additive manufacturing system

Abstract

A system for additive manufacturing, in particular using Direct Energy Deposition, which has the following features: - a workroom (18), - an enclosure (16) that limits the workspace (18), - at least one order header (46) for the application of 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 handling device (24, 324) can be used in a construction mode and a cleaning mode of the system, wherein in build mode at least one job head (46) is movable by the handling device (24, 324) in the work space (18), and wherein in cleaning mode the at least one cleaning head (62, 100) is movable by the handling device (24, 324) in the working space (18) in order to clean at least the working space (18) or a component (58), characterized by the fact that the application head (46) is detached from the handling device (24, 324) in cleaning mode and is in a park position, the cleaning head (62, 100) is detached from the handling device (24, 324) in construction mode and is in a park position, which is coupled to at least one order header (46) with at least one supply line (48), which is coupled with at least one cleaning head (62, 100) and at least one suction line (66, 104), and the lines (48, 66, 104) remain connected even in a respective parked position of the order head (46) or the cleaning head (62, 100).

Description

[0001] The present disclosure relates to an additive manufacturing system. At least in exemplary embodiments, the present disclosure relates to additive manufacturing systems using Direct Energy Deposition (DED).

[0002] Such systems and devices include, for example, a handling device with an application head and a workpiece carrier, wherein the handling device can move the application head relative to the workpiece carrier in order to apply material to a workpiece or substrate. From CN 1 07 671 285 A and CN 1 10 434 336 A, additive manufacturing systems are known, each comprising a handling device that simultaneously carries several heads, including a deposition head and a material removal head (for laser ablation). A disadvantage is that the handling devices must carry several heads simultaneously in different operating modes. German patent DE 10 2013 224 649 A1 discloses a combined system designed for both subtractive and additive machining. Abrasive tools and, if required, a finishing head can be inserted into the system's work area.

[0003] Additive manufacturing (AM) systems can be used for various applications. These include, for example, the complete production of components (entirely using additive manufacturing), the supplementary production of components (additive manufacturing in addition to conventional manufacturing for a single component), and / or use for repair purposes (a used part is refurbished using additive manufacturing). Another application for additive manufacturing systems is the coating of workpieces. In this way, workpieces with desired surfaces and properties can be created by applying a layer to an existing semi-finished product. It is conceivable to coat the outer surfaces of a workpiece. Furthermore, it is also conceivable to coat inner surfaces, i.e., surfaces facing inwards.The term additive manufacturing encompasses the fully additive creation of components, but also the additive application of materials to an already existing component.

[0004] The term Direct Energy Deposition (DED) encompasses various additive manufacturing processes that rely on melting and depositing material using a focused energy source, particularly high-energy radiation. The building material is typically supplied as a powder or wire.

[0005] A prime example of DED technology is laser metal deposition (LMD). Energy is supplied by a laser, which creates a molten pool on the component surface. Metal powder is automatically injected through a nozzle. The powder melts and bonds with the base material, forming welded beads that create structures on existing base materials or entire components. Multiple layers can be built up as needed. Argon, for example, is used as a shielding gas. However, DED processes that use metal wires instead of metal powder are also known.

[0006] DED processes allow for the creation of 3D structures even on uneven surfaces. This makes the process suitable for repairs and geometric modifications. Various materials can be used, enabling the production of components with inhomogeneous material structures. DED processes offer relatively high deposition rates compared to other additive manufacturing methods.

[0007] From EP 2 872 287 A2, an additive manufacturing device is known that uses the DED process. The system comprises a coating head that is movable relative to a tool carrier via a handling device. The handling device includes a carrier for the coating head, which is also designed to accommodate other heads, for example, machining heads for subtractive machining.

[0008] Additive manufacturing systems in industrial settings are cost-intensive. 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 material to create a sufficiently dense bond.

[0009] Additive manufacturing is now widespread, especially in industrial settings. The processing of metal materials, in particular, opens up new fields of application. Many current additive manufacturing systems focus on the actual build process. However, there are other process components, especially the necessary cleaning, that increase non-productive time.

[0010] Additive manufacturing often generates significant contamination in the build chamber. Due to the nature of the process, a considerable amount of contamination (for example, overspray) is frequently unavoidable. This negatively impacts production times, as extensive manual cleaning is often necessary. In other words, the build chamber and the component within it often need to be thoroughly cleaned before the component is removed after the build process.

[0011] Immediate removal of the component is often only possible with extensive personal protective equipment if the work area and the component have not been adequately cleaned. This also has a negative impact on its use in industrial environments. Components manufactured using AM are frequently subjected to post-processing, so any contamination can also have adverse effects during subsequent processing steps.

[0012] Excess powder from the build process, which settles in the build chamber, can even serve as raw material, possibly after appropriate processing. Contamination also occurs in the build chamber when using wire-based build materials. Generally, during additive manufacturing using DED, metal fumes, welding gases, and similar substances can form in the build chamber, settling on surfaces within the build chamber, on system components, and even on the component itself. Therefore, it is often advisable to clean not only the component but also its surroundings. It is recommended to clean the build chamber, including the kinematics within it, at least periodically, and at least in sections.

[0013] Intensive cleaning may be necessary, for example, when changing materials. In such cases, for reasons of material separation, contaminants must be removed as completely as possible.

[0014] One advantage of additive manufacturing using DED is its high variability, as material can be applied in a targeted manner. The application head can often be moved along multiple axes relative to the workpiece within the workspace and, if necessary, even swiveled. This design freedom allows for the additive manufacturing (including additive machining, coating, and similar processes) of a wide variety of components in a single machine. However, this also affects the resulting contamination pattern.

[0015] Against this background, the invention aims to provide an additive manufacturing system that is flexible and suitable for industrial applications. Preferably, the system reduces the need for personal protective equipment when removing components after the build process. Ideally, such a system is suitable for automated manufacturing. Preferably, the system allows for a reduction in downtime by minimizing the time required for manual cleaning, particularly before component removal. Furthermore, the system should minimize operator exposure to contamination (dust), at least in exemplary embodiments. Ideally, the system's operation should be simplified overall.

[0016] According to a first aspect of the present disclosure, the problem is solved by an additive manufacturing system, in particular by means of Direct Energy Deposition, wherein the system comprises the following: - a workspace, - an enclosure that limits the workspace, - at least one order header for the application of a building material, - a handling device with a receiver, and - an integrated cleaning system with at least one cleaning head, the handling device can be used in a construction mode and a cleaning mode of the system, in build mode at least one job head can be moved by the handling device in the work area, wherein in cleaning mode at least one cleaning head can be moved by the handling device in the work area in order to clean at least the work area or a component, wherein the application head is detached from the handling device in cleaning mode and is in a parked position, where the cleaning head is detached from the handling device in construction mode and is in a parked position, where at least one order header is coupled with at least one supply line, wherein at least one cleaning head is coupled to at least one suction line, and the lines remain connected even in the respective parked position of the application head or the cleaning head.

[0017] The problem solved by the invention is thus resolved.

[0018] According to the invention, integrated and automated cleaning is enabled, thus reducing any additional cleaning effort, particularly manual cleaning. Preferably, a separate cleaning device for removing residues from the additive manufacturing process can be dispensed with.

[0019] In one exemplary configuration, the integrated cleaning system enables the removal of contaminants and residues (powder, overspray, etc.), allowing the component (workpiece) to 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.

[0020] In one exemplary configuration, the system is designed as a self-cleaning system. In this exemplary configuration, the handling device provides degrees of freedom of movement that enable the system to clean itself, particularly the component.

[0021] In exemplary embodiments, the handling device is primarily used to generate relative movement between the application head and the workpiece. Furthermore, in other embodiments, the primary task of the handling device is a handling task, such as the automated loading (especially unloading) of the system. Guiding the cleaning head within the work area can be considered a secondary task, at least in exemplary embodiments. In other words, at least in exemplary embodiments, axes or degrees of freedom that are already present in the system are used for cleaning, particularly exclusively. In such a case, the cleaning function is provided by existing handling devices.

[0022] The handling device generally provides a motion kinematic system. This can be serial kinematics, for example in the form of a robot (e.g., an articulated robot arm), or Cartesian kinematics (e.g., a moving column, portal design, gantry design). Alternatively, parallel kinematics are conceivable.

[0023] In one exemplary configuration, the additive manufacturing system is designed to process metal-based or metal-containing building materials, for example by softening or melting them. The system is also configured to generate thermal energy, particularly in the form of laser beams, whereby the thermal energy is used to soften and melt the supplied building material. In this way, material can be applied layer by layer.

[0024] The system is designed as either a DED (Direct Energy Deposition) or LMD (Laser Metal Deposition) system. The material to be processed is provided as either powder or wire. It is also conceivable to integrate both types of material feed into a single system.

[0025] At least in exemplary configurations, these systems do not involve so-called powder bed fusion systems, where a powder is applied layer by layer in a chamber and then partially melted. Instead, DED or LMD systems are equipped with an application head that can precisely apply the material to specific positions. The application head is typically movable along multiple axes relative to the component, allowing for the creation of complex geometries.

[0026] In powder bed fusion systems (for example, selective laser sintering, SLS), powder layers are regularly stacked in special build chambers (for example, build cylinders) to produce components. Such a build chamber typically has a base area that is completely covered with powder layer by layer. However, this means that the powder is already confined within a defined volume when it partially melts and solidifies.

[0027] In DED systems with an application head, excess powder, overspray, and other contaminants spread more freely within the work area, potentially resulting in a larger area becoming contaminated. Therefore, it is advantageous if the cleaning head, like the application head, can be moved within the work area relative to the work area or the component, and especially if the handling device allows movement within a relatively large range of motion. Local concentrations of contamination may occur, but it must be expected that large areas within the work area will be at least partially contaminated.

[0028] According to one exemplary embodiment, the integrated cleaning system is designed to clean the workspace and at least one additively manufactured component located within the workspace. In other words, the cleaning system can, at least in exemplary embodiments, clean both the component and its surroundings, as well as the interior of the workspace as a whole, or at least significant sections thereof.

[0029] In one exemplary configuration, the integrated cleaning system achieves a level of cleanliness that allows the component to be removed without extensive personal protective equipment. In other words, in exemplary configurations, the integrated cleaning system is capable of enabling component removal in normal atmospheric conditions. This allows for a reduction in the manufacturing costs of additive manufacturing (AM).

[0030] According to another exemplary embodiment, the handling device has a receptacle for receiving at least one cleaning head. This can include a design in which the receptacle is configured to receive both the at least one application head and the at least one cleaning head. Typically, the cleaning head and the application head are not attached to the receptacle simultaneously, but sequentially. In this way, the handling device can carry and move an application head and a cleaning head (possibly sequentially) within the work area. According to another exemplary embodiment, the handling device has a carrier with an interface to which the application head and the cleaning head (suction head) can be attached.In an exemplary embodiment, the application head and cleaning head use at least partially the same fastening elements for attachment to the receptacle of the handling device.

[0031] According to another exemplary embodiment, 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. This allows for designs in which handling devices required for the construction process can also be used for cleaning.

[0032] According to another exemplary embodiment, the handling device is designed to receive and move at least one application head. Accordingly, the cleaning device is also intended for the actual material application within the additive manufacturing process. Key embodiments of the disclosure utilize the handling device for both the movement of the application head and the movement of the cleaning head. In this way, existing axes of motion (degrees of freedom) in the system, which are necessary for the more or less complex manufacturing 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 as the application head. This can contribute to increased cleaning performance.

[0033] According to one exemplary embodiment, the handling device is a key kinematic element of the system that generates relative movements between the application head and the workpiece or workpiece carrier during additive manufacturing or machining, enabling the application of building material at the desired position and in the desired orientation. According to one exemplary embodiment, the same motion kinematic system can be used for both the application head and the cleaning head.

[0034] According to one exemplary embodiment, the motion kinematics can be operated in a head-changing mode to switch between the application head and the cleaning head. This allows for an automated changeover between the application head and the cleaning head. Cleaning can thus be integrated even more flexibly into the additive manufacturing process.

[0035] According to another alternative embodiment, the handling device is a secondary kinematic system. A secondary kinematic system is provided in addition to a main kinematic system. It can, for example, be a handling device for workpiece changes, head changes, measurements, or the like, which can also be used for cleaning purposes.

[0036] The handling unit can be used in both a construction mode and a cleaning mode of the system. In construction mode, the handling unit carries at least one application head. In cleaning mode, the handling unit carries at least one cleaning head.

[0037] According to this configuration, the handling device is used for both the actual construction and the cleaning of the system. In other words, if the handling device is used for both purposes, the additive manufacturing and cleaning processes are sequential. This includes cleaning the work area and / or the workpiece after completion of the additive manufacturing task. However, it is also conceivable to interrupt the additive manufacturing process in stages to perform cleaning in between.

[0038] According to another exemplary embodiment, the handling device features linear kinematics with Cartesian axes. Such a handling device is designed, for example, according to the moving column principle, portal principle, gantry principle, or a similar principle. It is understood that both the build and cleaning processes depend on relative movements between the respective heads (application head and cleaning head) and the component or the work area. Therefore, designs are also conceivable in which at least one axis of movement is located directly at the component or its fixture. This is not to be understood as a limitation.

[0039] According to another exemplary embodiment, the handling device comprises a robot, in particular an articulated robot. In industrial settings, such robots are also referred to as industrial robots, universal robots, or articulated robots. In one exemplary embodiment, the robot is designed as a robot with serial kinematics. Individual joints of the robot are arranged sequentially (in a series), articulated to their neighbors, and each is movable relative to the others, usually pivotable. In this way, an end effector (also referred to as a "hand") can be moved, in particular freely, within a movement space defined by the kinematics. The robot's "hand" carries, for example, the receptacle for the application head and / or cleaning head.

[0040] Using a robot as part of the handling system, preferably as an essential part of the handling system for the application head(s), has the advantage that the parking positions of individual application heads can be selected within the robot's given movement space. This allows the parking positions to be spaced apart from each other.

[0041] In one exemplary configuration, the robot is positioned within the workspace and can only move within that workspace. In this way, the robot is enclosed by the workspace's housing during productive use. This also reduces any potential contamination from the system into the surrounding environment. Furthermore, safety is increased because the robot is shielded by the housing during its productive operation.

[0042] Serial kinematics include, for example, portal robots, horizontal articulated robots (SCARA robots), articulated robots with 5, 6, or 7 rotational axes, and similar designs. It goes without saying that robots can also have parallel kinematics, such as so-called delta robots or hexapod robots. Hybrid forms are also readily conceivable.

[0043] The positioning accuracy and repeatability provided by the robot are sufficient for additive manufacturing purposes. In other words, the robot can be used for the fine positioning and feed movement of the application head and the cleaning head.

[0044] According to another exemplary embodiment, the handling device is capable of moving the cleaning head to any desired position within the workspace in order to clean the workspace and the components located therein. Therefore, it is advantageous to use a handling device with a high degree of freedom of movement and a large working area, such as an articulated robot or a flexible robot arm.

[0045] According to another exemplary embodiment, at least one cleaning head is a suction head that can be moved within the work area. In other words, the cleaning system according to this embodiment constitutes a suction device for extracting residual materials from the work area. In this way, a large proportion of the contaminants can be removed in an orderly manner and collected in a controlled manner.

[0046] In a typical DED additive manufacturing application, approximately 20-40% of the applied build material is generated as overspray. This is not a limitation. Excess material must be removed to allow the component to be removed without additional protective measures and processed further. In other words, excess powder can be vacuumed up and collected.

[0047] Furthermore, additional contaminants regularly accumulate in the work area, such as spatter ("weld beads") during surfacing, slag, other combustion residues, foreign materials, and more. A large portion of these contaminants can also be removed and collected by extraction.

[0048] It goes without saying that designs with multiple cleaning heads are also conceivable. This can involve several suction heads that differ from one another, for example, in their nozzle design.

[0049] According to a further alternative embodiment, at least one additional cleaning head is provided, designed for mechanical cleaning, in particular as a brush head. This brush head is exemplified by being equipped with a brush (round brush, flat brush, or the like). The brush head can be equipped with a drive mechanism for the brush to loosen adhering dirt. However, it is also conceivable that the brush head is moved by the handling device, either alternatively or additionally, to loosen adhering dirt.

[0050] It goes without saying that a combined brush and suction head can also be provided, which on the one hand loosens adhering material and on the other hand vacuums it up using the integrated suction function.

[0051] According to another exemplary embodiment, the brush head works together with the extraction system to remove residual materials and direct them out of the work area.

[0052] According to another exemplary embodiment, the system is designed exclusively as an AM system (additive manufacturing system). In other words, exemplary configurations are conceivable in which no subtractive post-processing takes place within the build chamber itself. Such post-processing can be carried out on downstream machines, if necessary. Cycle times for subtractive post-processing machines are often shorter than cycle times for additive machining machines. Therefore, the overall throughput time and manufacturing effort can be optimized by combining AM systems with separate machine tools for subtractive (cutting) machining, at least in exemplary configurations.

[0053] According to another exemplary embodiment, two or more holders are provided in the work area to accommodate at least one application head and at least one cleaning head, offering at least two parking positions. In this way, the handling device can first set down one head and then pick up the next. It is understood that combined holders with two picking positions are also conceivable. If both the at least one application head and the at least one suction head are arranged in the work area, the transfer of contaminants (powder and the like) to the surrounding environment is further reduced.

[0054] According to a further exemplary embodiment, at least one holder with a storage compartment for the application head and at least one holder with a storage compartment for the cleaning head are provided. According to this embodiment, the application head is held in its holder when the cleaning head is attached to the receptacle of the handling unit. The cleaning head is held in its holder when the application head is attached to the receptacle of the handling unit.

[0055] The at least one application head is connected to at least one supply line, and the at least one cleaning head is connected to at least one suction line. The lines remain connected even when the application head or cleaning head is in its respective parked position. This prevents contamination of the lines (the inside of the lines). Furthermore, this design allows for quick changes between application heads and cleaning heads, as the effort required to connect and disconnect lines is eliminated for at least some lines.

[0056] According to another exemplary embodiment, the system further comprises a control unit for controlling the cleaning system, wherein the control unit controls the handling device during a cleaning mode to move the cleaning head relative to the work area. 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 build mode to move the application head relative to the work area or relative to the component. The movement typically takes place within the build area.

[0057] According to another exemplary embodiment, the control unit is designed to initiate a self-cleaning process of the system, particularly the work area containing the component, following a build process. In this way, cleaning occurs after the additive manufacturing process, which can simplify the removal and subsequent handling of the component.

[0058] According to another exemplary embodiment, the control unit is configured to initiate intermittent intermediate cleaning of the workspace and / or the component during the build process. The control unit is preferably configured to initiate intermediate cleaning when the build process includes a rest phase, particularly a cooling phase. In this way, cleaning can be performed during the build process itself, thus reducing overall contamination. Since cooling cycles are often already included in additive manufacturing processes, the cycle time does not increase excessively in exemplary embodiments despite intermediate cleaning. This is not to be understood as a limitation. Intermediate cleaning can be performed periodically or on demand. Build phases and cleaning phases can alternate.

[0059] According to another exemplary embodiment, the control unit is designed to initiate cleaning depending on the degree of contamination. For example, the control unit is designed to initiate a cleaning process when certain parameters for build quality and resulting workpiece properties are exceeded or are at risk of being exceeded.

[0060] According to a further exemplary embodiment, the system also includes 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 coverage.

[0061] According to another exemplary embodiment, the contamination sensor is designed to optically detect the degree of surface coverage in the work area. This can further increase cleaning efficiency.

[0062] According to another exemplary embodiment, the contamination sensor is coupled with a light source. This light source could be, for example, a lamp for area illumination or a laser light source. It is conceivable that the light source could be used to provide essentially homogeneous illumination of the work area. It is also conceivable that the light source could be used to project a pattern onto surfaces in the work area or onto the component itself, so that the contamination sensor could then use this pattern to determine the degree of contamination / coverage.

[0063] According to one exemplary embodiment, the light source is designed as a flash light source, whereby the degree of coverage is determined depending on the resulting reflection behavior of the surface.

[0064] According to another exemplary embodiment, the workspace has at least one guiding element (for example, a guide plate). This guiding element can be, for example, a cover or panel. Furthermore, guiding elements can serve to direct accumulating particles into areas that are easily accessible to the cleaning system with its at least one cleaning head. For example, guide plates positioned at an angle (inclined relative to the horizontal) are provided as guiding elements in the floor area of ​​the workspace. In this way, otherwise horizontally oriented surfaces can be at least partially covered with surfaces inclined relative to the horizontal, so that particles are directed downwards and, in particular, into an area that is easily accessible to the cleaning head, where they are concentrated.Similarly, guide elements for the handling device and other installations in the work area can also be at least partially covered with guide elements to improve particle removal / dust guidance.

[0065] According to another exemplary embodiment, the guide plate has at least one pocket or recess for collecting residues. In other words, a sink can be provided for powders and other particles, in which contaminants collect. This simplifies cleaning.

[0066] According to another exemplary embodiment, the enclosure of the work area is designed to be at least dust-tight, preferably gas-tight. In this exemplary embodiment, "tightness" is understood to mean within the usual limits for a protective gas atmosphere. Accordingly, absolute tightness is not absolutely necessary. Nevertheless, a sufficiently tight enclosure can effectively reduce the transfer of contaminants into the environment of the system. In this way, the concentration of any particles in the vicinity of the system can be reduced. Thus, the system can potentially be operated in normal manufacturing environments, ideally without the need for specific personal protective equipment (especially regarding dust exposure) for operators in the vicinity of the system.

[0067] According to another exemplary embodiment, the enclosure is accessible via a door, which is equipped with a door control system that releases the door for opening after production is complete and a desired level of cleanliness has been achieved. The door control system can be implemented by the control unit. Ideally, the door control system only releases the door if, with the door open and any loading or setup operations taking place, only a small amount of particles from the work area can be released into the environment.

[0068] According to another exemplary embodiment, the handling device is designed to perform self-cleaning with the integrated cleaning head. In other words, a robot, for example, as part of the handling device, can clean itself at least partially, and in particular at least in essential areas. The self-cleaning of the handling device is facilitated if the handling device has multiple degrees of freedom and corresponding axes of movement with a sufficiently large range of motion.

[0069] According to another exemplary embodiment, the system also features a recovery unit for reclaiming reusable building material from an extracted gas-particle mixture. The integrated cleaning system allows for the targeted and sufficiently pure collection of excess powder or other building material. In this way, the effort required for reprocessing can be reduced, at least in exemplary embodiments. Furthermore, the integrated cleaning system as a whole allows for the direct collection and processing of larger quantities if a high level of cleanliness is achieved directly within the work area.

[0070] According to another aspect, the present disclosure relates to a method for additive manufacturing, in particular by means of Direct Energy Deposition, comprising the following steps: - Provision of an additive manufacturing system, in particular a system according to one of the configurations described herein, wherein the system comprises the following: - a workspace, - an enclosure that limits the workspace, - at least one order header for the application of a building material, wherein the at least one order header is coupled with at least one supply line, - a handling device with a receiver, wherein the handling device can be operated in a construction mode and a cleaning mode of the system, and - an integrated cleaning system with at least one cleaning head, wherein the at least one cleaning head is coupled to at least one suction line, wherein at least one cleaning head is movable by the handling device in the work area in order to clean at least the work area or a component, - Operating the system in a build mode, wherein the at least one application head is moved by the handling device to generate an additive application onto a component, wherein the cleaning head is detached from the handling device in build mode and is in a park position, and - Operating the system in a cleaning mode, wherein the at least one cleaning head is moved through the handling device to clean at least the work area or a component, wherein the application head is detached from the handling device in cleaning mode and is in a park position, the lines of the application head and the cleaning head remain connected even in the respective parked position of the application head or the cleaning head.

[0071] In this way, too, the task of disclosure is fully accomplished. It is understood that the disclosed procedure can be further developed analogously to the disclosed design. This applies, for example, to the various functions of the control unit.

[0072] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of this disclosure.

[0073] Further features and advantages of the invention will become apparent from the following description and explanation of several exemplary embodiments with reference to the drawings. These show: Fig. 1: A schematic view of a design of an additive manufacturing system with an integrated cleaning system, in a build mode; Fig. 2: another view of a design in contrast to the design according to Fig. 1 modified system, in a cleaning mode; Fig. 3: Another schematic view based on the Fig. 1 and Fig. 2 illustrated systems to demonstrate the functionality of a further design of an integrated cleaning system; Fig. 4: Another view based on Fig. 3, with a changed position of the handling device; Fig. 5: another view based on the Fig. 3 and Fig. 4, with a changed position of the handling device; Fig. 6: another schematic view of an exemplary design of an additive manufacturing system with an integrated cleaning system; Fig. 7: another schematic view of an exemplary design of an additive manufacturing system with an integrated cleaning system; Fig. 8: a flowchart illustrating a configuration of a process for the additive manufacturing of workpieces; and Fig. 9: A flowchart illustrating a further development of a process for the additive manufacturing of workpieces.

[0074] Fig. Figure 1 illustrates, using a highly simplified schematic representation, an exemplary embodiment of an additive manufacturing system, which is designated as 10 in its entirety. Fig. Figures 2-7 illustrate further conditions and exemplary designs of such facilities. In the Fig. 1-7 denote identical (at least functionally identical) elements and units with identical reference symbols. Individual aspects and designs of the in the Fig. The illustrated embodiments shown in 1-7 can be incorporated into other designs or combined with them. To avoid repetition, the following applies particularly in connection with the Fig. 2-7 primarily addressed differences, modifications and / or additions compared to the previously mentioned embodiments.

[0075] Annex 10 according to Fig. 1 is specifically designed as a DED facility. Facility 10 serves as an example. Fig. System 10 is designed for additive manufacturing using laser cladding (also known as LMD). Specifically, system 10 is designed for the additive manufacturing (including repair, coating, and similar additive processes) of components using metallic materials. In the DED or LMD process, the build material is typically supplied in powder or wire form.

[0076] In the exemplary embodiment, system 10 comprises a frame 12 with a base 14. The base 14 can, for example, also be formed by the floor of a workshop. Furthermore, system 10 includes an enclosure 16, which, for example, forms side walls. The enclosure 16 can also include an upper wall (ceiling) and, optionally, a lower wall (floor). The frame 12 and, in particular, the enclosure 16 define a workspace 18. Preferably, the workspace 18 is sufficiently sealed from the environment, and preferably designed to be sufficiently dustproof.

[0077] In the exemplary embodiment according to Fig. Furthermore, a door 20 is formed in the enclosure 16, through which the workspace 18 is accessible. The door 20 can be opened and closed, for example, for loading processes, handling processes, and the like. It is understood that the door 20, when closed, also adequately seals the workspace 18, in particular, it can seal the workspace 18 dust-tight.

[0078] A handling device 24 is arranged in the workspace 18. In this exemplary embodiment, it comprises a robot 26 designed as an articulated robot or articulated robot. The robot 26 includes, for example, a base 30 arranged on the base 14. Extending from the base 30 are elements 32, 34, and 36, which can also be referred to as links in the kinematic chain of the robot 26. In this exemplary embodiment, the robot 26 has serial kinematics. The elements 32, 34, and 36 are each connected to their neighbors via joints and are movable relative to one another. This provides the robot 26 with a movement space that is accessible to an end effector of the robot 26. The robot 26 has a high number of degrees of freedom.

[0079] In the exemplary embodiment according to Fig. 1. A mounting 40 is attached, which carries a job head 46 for additive manufacturing. For example, a supply line 48 is connected to the job head 46, which is in Fig. 1 is only schematically indicated and interrupted. The supply line 48 can supply the application head 46 with the building material (powder or wire), process fluid (e.g., protective gas), energy, and / or control signals. The supply line 48 can also be used to provide high-energy radiation (e.g., laser radiation).

[0080] In the work area 18, a workpiece holder in the form of a workpiece table 56 is arranged on the base 14. The workpiece carrier or workpiece table 56 carries a component 58, which is additively manufactured, or at least additively machined / coated, by the system 10. The handling device 24 can move the application head 46 in a desired manner to selectively apply and solidify building material. In this way, the component 58 can be additively manufactured, coated, and / or repaired.

[0081] The system 10 further comprises an integrated cleaning system 60. The cleaning system 60 includes at least one cleaning head 62. The cleaning head 62 is designed, for example, as a suction head and is provided with at least one nozzle 64. The cleaning head 62 is connected to a line 66, in particular a suction line. For example, a line guide 68 is provided in the working chamber 18, which is Fig. Figure 1 is only shown 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 a limitation.

[0082] The handling device 24 is designed to carry both the application head 46 and the cleaning head 62 and to move within the work chamber 18. In other words, the handling device 24 can, on the one hand, additively manufacture the component 58 and, on the other hand, clean the work chamber 18 and the component 58. For this purpose, the receptacle 40 of the handling device 24 is designed to carry either the cleaning head 62 or the application head 46 as needed. In this way, within the Fig. In the embodiment shown in 1, no additional handling device 24 is required for cleaning with the cleaning head 62.

[0083] In Fig. 1 is further designated by 76 as 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 Fig. In the configuration shown in Figure 1, a light source 84 is also assigned to the sensor unit 76. The sensor unit 76 is designed to determine the degree of contamination or coverage of the workspace 18 or the component 58. The light source 84 can help to create favorable lighting conditions for determining the degree of contamination. However, it is also conceivable to use the light source 84 to project specific patterns onto surfaces in the workspace 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. In this way, a powder concentration or dust concentration can also be determined.

[0084] In one exemplary embodiment, the sensor unit 76 is configured to determine a particle concentration in the atmosphere in the workspace 18, for example by means of photometric dust measurement. It is also conceivable to configure the sensor unit 76 to detect both the degree of surface coverage and the particle / dust concentration in the workspace 18.

[0085] Annex 10 also contains a Fig. Figure 1 shows a control unit 90, which is only symbolically represented. 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 configured to operate the system 10 in a build mode and, if required, in a cleaning mode. In build mode, the handling device 24 carries the application head 46. In cleaning mode, the handling device 24 carries the cleaning head 62. In this way, one and the same handling device 24, in particular one and the same robot 26, can be used selectively for either the build process or for cleaning.

[0086] The handling device 24, with its end-end receptacle 40, is designed to selectively grasp and support either at least one cleaning head 62 or at least one application head 46. In other words, both the cleaning head 62 and the application head 46 have an active and an inactive state. The inactive state can also be referred to as the park position. The embodiment shown in Annex 10 is as follows: Fig. Figure 1 shows a holder 94 and a holder 96. Holder 94 is designed as an example to hold the cleaning head 62. Holder 96 is designed as an example to hold the application head 46; see also Fig. 2. It is understood that the holders 94, 96 can be designed to accommodate both an application head 46 and a cleaning head 62, at least in exemplary embodiments.

[0087] In Fig. In step 1, plant 10 is in construction mode. Fig. 2. The system 110 is in cleaning mode. The change from construction mode to cleaning mode includes, for example, the transfer of the application head 46 to the holder 96 and the retrieval of the cleaning head 62 from the holder 94. The change from cleaning mode to construction mode includes, for example, the transfer of the cleaning head 62 to the holder 94 and the retrieval of the application head 46 from the holder 96.

[0088] In one exemplary embodiment, the line 66 of the cleaning head 62 remains connected to the cleaning head 62 even when the system 10 is in build mode. Similarly, in another exemplary embodiment, the line 48 of the application head 46 remains connected to the application head 46 even when the system 10 is in cleaning mode. This further simplifies the switch between build mode and cleaning mode. The number of interfaces that need to be operated is reduced.

[0089] Cleaning of the work chamber 18 or component 58 can be initiated by the control unit 90 based on a contamination signal provided by the sensor unit 76. It is conceivable to operate the system 10 in such a way that the control unit 90 initiates cleaning only when necessary, i.e., when a certain degree of contamination is reached. However, it is also conceivable to operate the system 10 in such a way that the control unit 90 initiates cleaning at intervals. For such periodic cleaning, cooling breaks and similar process-related interruptions of the build process can be used, for example. It goes without saying that a combination of periodic and on-demand cleaning is also possible. It is also conceivable, in principle, to complete the build process and then clean the work chamber 18 and component 58 before removing component 58.

[0090] In one exemplary embodiment, the control unit 90 is designed to achieve a compromise between the shortest possible cycle time and high component quality (accompanied by low contamination). In this exemplary embodiment, cleaning with the integrated cleaning system 60 is carried out 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 at least a sufficiently clean state. In this way, the system 10 can be easily integrated into existing production environments.

[0091] The control unit 90 can also include a door control. For example, the control unit 90 is configured to release the door 20 only when the integrated cleaning system 60 has reached a desired level of cleanliness. This might be the case, for instance, when the work area 18 has been sufficiently cleaned so that the component 58 can be removed without special protective measures.

[0092] Fig. Figure 2 illustrates a configuration of a plant designated 110, which corresponds to Annex 10 according to Fig. 1 is similarly designed. The facility 110 in Fig. 2 is in cleaning mode, whereas system 10 is in [the following] Fig. 1 in build mode. In Fig. 1. The cleaning head 62 is in a parked position at the holder 94. In Fig. 2 the order head 46 is in a parked position at holder 96.

[0093] In cleaning mode, the handling device 24 carries the cleaning head 62 to remove powder residue, dust, and the like from the component 58 or from the work area 18. For this purpose, the handling device 24 utilizes the degrees of freedom already provided for the build process. In this way, the cleaning head 62 can be moved with a high degree of freedom within the work area 18 to clean it, at least in sections.

[0094] Fig. Figure 2 further illustrates that the system can have 110 additional cleaning heads. For example, in addition to the cleaning head 62, which is designed as a suction head, another cleaning head 100, designed as a brush head, is provided. The cleaning head 100 has a brush 102. The brush can be equipped with its own drive. The brush 102 serves for mechanical cleaning or for loosening deposits. The cleaning head 100 can also optionally be equipped 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 deposits. However, this is not to be understood as a limitation.

[0095] In one exemplary embodiment, the control unit 90 is designed such that, in cleaning mode, loose particles are first vacuumed up by the cleaning head 62, which is designed as a suction head, and that the cleaning head 100, designed as a brush head, is then used to loosen any remaining adhering deposits. These can then be vacuumed up. Other cleaning modes are conceivable. The [details of the following are missing from the original text]. Fig. The systems illustrated in 1-7 can also be equipped with several application heads 46, which are held by the handling device 24 as required and used in build mode.

[0096] The Fig. Figures 3-5 illustrate a further embodiment of a plant designated 210, which corresponds to Annexes 10 and 110 according to the Fig. 1 and Fig. 2 is fundamentally similar in design. In the respective workspace 18, guide elements 220, 222 are arranged, which cover certain sections of the workspace 18. The guide elements 220, 222 are, for example, guide plates, panels and the like. In the Fig. In 3-5, the guide elements 220, 222 are inclined relative to the horizontal. This allows for targeted powder guidance (assisted by gravity). In the exemplary embodiment, the guide elements 220, 222 open into a depression 224 where powder and other contaminants accumulate. It is understood that further / other guide elements can be provided to cover hard-to-reach areas in the working chamber 18. This simplifies cleaning with the integrated cleaning system 60.

[0097] Fig. Figure 3 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 contaminants can be extracted from the sink 224 or otherwise removed. Fig. Figure 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 contaminants can be extracted from the component 58 or from the area surrounding the component 58, from walls and other surfaces of the workspace 18, or otherwise removed, for example, in the area around the door 20. In an exemplary embodiment, the movement area of ​​the handling device 24 is adapted to the dimensions of the workspace 18 in such a way that the interior surfaces of the enclosure 16 can be cleaned at least in sections.

[0098] Fig. Figure 5 illustrates that, according to an exemplary embodiment of the cleaning system 60, self-cleaning of the handling device 24 is possible. For example, the robot 26 (see Figure 5) can... Fig. 1) the handling device 24 is operated in such a way that essential sections of the kinematics of the robot 26 can be cleaned with the cleaning head 62 mounted on the holder 40.

[0099] Fig. Figure 6 illustrates a further exemplary embodiment of an additive manufacturing system designated 310. System 310 is modified compared to systems 10, 110, and 210 in that it provides separate handling devices 24 and 324 for the application head 46 and the cleaning head 62. In this embodiment, two handling devices 24 and 324 are provided, each designed as a robotic handling device 24 and 324, respectively.

[0100] The handling device 24 – which has already been described – serves as the main kinematics 328. The handling device 24 carries the application head 46. In contrast, the handling device 324 serves as secondary kinematics 330 and carries the cleaning head 62. The handling device 324 is designed as an example robot 326. 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 ( Fig. 1) The robot 326 is also designed as an articulated-arm or swivel-arm robot. The robot 326 has a receptacle 340 at its effector-side end for receiving the cleaning head 62.

[0101] Fig. Figure 6 further illustrates a workpiece gripper 348, which is arranged on a holder 350 in the work area 18. The workpiece gripper 348 is, for example, designed as a pneumatic gripper with a corresponding supply line. In an exemplary embodiment, the handling device 324, which serves as secondary kinematics 330, is designed to alternately carry the workpiece gripper 348 or the cleaning head 62 and move it within the work area 18. In the exemplary embodiment, the holder 350 is connected to the holder 94 or the holder 96 (see also Figure 6). Fig. 2) similarly designed, however this is not to be understood as restrictive. The secondary kinematics 330 can 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. In this embodiment as well, no additional handling device is required in cleaning mode.

[0102] Even at the in Fig. In the illustrated design of system 310, the build mode and cleaning mode can follow each other sequentially and repeat themselves several times. However, it is also conceivable to design the control unit 90 in such a way that the build mode and cleaning mode overlap, at least temporarily. In this way, the cycle time can be further reduced.

[0103] Fig. Figure 7 illustrates another exemplary configuration of an additive manufacturing system designated 410. System 410 differs from those previously described in connection with the Fig. Figures 1-6 illustrated systems 10, 110, 210, and 310, showing that the handling unit 24 does not have a robot, but rather a linear kinematic system 430, which is designed, for example, as a Cartesian kinematic system. In other words, the kinematic system 430 is designed, for example, as an XYZ kinematic system, i.e., with three mutually perpendicular axes of motion.

[0104] Fig. Figure 7 illustrates two mutually perpendicular axes of movement. A first axis with a horizontal orientation is defined by a horizontal guide 432 and a slide 434 mounted on it. A second axis with a vertical orientation is defined by a vertical guide 436 and a slide 438. In the exemplary embodiment, the vertical guide 436 sits on the slide 434 and moves together with it along the horizontal guide 432. The kinematics 430 are designed as a column kinematics by way of example. However, this is not to be understood as a limitation. It is understood that a third axis with a corresponding guide and slide can also be provided, as exemplified in the [reference to be added]. Fig. The selected orientation extends perpendicular to the viewing plane. Furthermore, pivot axes, rotation axes, and similar features can be provided that are parallel to the aforementioned axes.

[0105] With a handling device 24 equipped with a Cartesian kinematics 430, the application head 46 can be held in a build mode and the cleaning head 62 in a cleaning mode and moved relative to the working space 18 or to the component 58, respectively.

[0106] Fig. Figure 8 illustrates an exemplary embodiment of an additive manufacturing process, particularly using DED, by means of a schematic flowchart. The process comprises 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 build mode to additively manufacture, coat, and / or repair a component. Preferably, the additive manufacturing process includes the deposition and solidification of a metal-based or metal-containing build material. This includes, for example, steel materials, aluminum materials, titanium materials, nickel-based materials, and alloys containing these materials.

[0107] In a further step S14, the system is operated in a cleaning mode, in particular an integrated cleaning mode. Preferably, the same handling device is used in both cleaning mode and build mode to hold an application head and a cleaning head, respectively, and to move them within a work area of ​​the system. For example, the cleaning is carried out to a degree that, in a further step S16, allows the component to be removed and further processed without special personal protective equipment.

[0108] Fig. Figure 9 illustrates, using a schematic flowchart, a further exemplary embodiment of a process for additive manufacturing, in particular using DED. The process includes a step S20, which involves the provision of a system, in particular a system according to at least one embodiment described herein.

[0109] Step S22 follows, comprising a combined construction process. Step S22 includes sub-steps S24 and S26, which are executed once or several times sequentially. Sub-step S24 relates to a construction mode. Sub-step S26 relates to a cleaning mode. Sub-steps S24 and S26 can be executed alternately, allowing for intermittent cleaning during the construction process.

[0110] In one exemplary embodiment, cooling breaks and similar process-related pauses in the build process are used for the intermediate cleaning steps S26. After completion of the build process S22 and sufficient cleaning, the component can be removed in a subsequent step S28, preferably without the need for extensive personal protective equipment. Ideally, the component can be removed and fed into further manufacturing steps without specific, purpose-built protective equipment, which entails corresponding effort in use and costs.

Claims

[1] Additive manufacturing system, in particular using Direct Energy Deposition, comprising the following: - a workroom (18), - an enclosure (16) that limits the workspace (18), - at least one order header (46) for the application of 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 handling device (24, 324) can be used in a construction mode and a cleaning mode of the system, wherein in build mode at least one job head (46) is movable by the handling device (24, 324) in the work space (18), and wherein in cleaning mode the at least one cleaning head (62, 100) is movable by the handling device (24, 324) in the working space (18) in order to clean at least the working space (18) or a component (58), characterized by , that the application head (46) is detached from the handling device (24, 324) in cleaning mode and is in a park position, the cleaning head (62, 100) is detached from the handling device (24, 324) in construction mode and is in a park position, which is coupled to at least one order header (46) with at least one supply line (48), which is coupled with at least one cleaning head (62, 100) and at least one suction line (66, 104), and the lines (48, 66, 104) remain connected even in a respective parked position of the order head (46) or the cleaning head (62, 100). [2] System according to claim 1, wherein the integrated cleaning system (60) is configured to clean the working space (18) and at least one additively produced component (58) arranged in the working space (18). [3] Device according to 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 the at least one application head (46). [4] System according to one of claims 1-3, wherein the handling device (24, 324) is a secondary kinematic (330). [5] System according to one of claims 1-4, wherein the handling device (24, 324) has a linear kinematics (430) with Cartesian axes. [6] System according to one of claims 1-4, wherein the handling device (24, 324) comprises a robot (26, 326). [7] System according to claim 6, wherein the robot (26, 326) is an articulated arm robot. [8] Apparatus according to one of claims 1-7, wherein the at least one cleaning head (62, 100) is a suction head which is movable in the working space (18). [9] Apparatus according to one of claims 1-8, wherein at least one further cleaning head (62, 100) is provided which is designed for mechanical cleaning, in particular as a brush head. [10] Device according to one of claims 1-9, wherein in the work space (18) two or more holders (94, 96, 106) are provided for receiving the at least one application head (46) and the at least one cleaning head (62, 100), which provide at least two parking positions. [11] System according to one of claims 1-10, 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 to move the cleaning head (62, 100) relative to the working space (18). [12] Plant according to claim 11, wherein the control unit (90) is configured to initiate self-cleaning of the plant following a construction process. [13] System according to claim 12, wherein the control unit (90) is configured to initiate self-cleaning of the work space (18) with the component (58) following a construction process. [14] System according to one of claims 11-13, wherein the control unit (90) is configured to initiate intermittent intermediate cleaning of the work space (18) and / or the component (58) during the construction process, and wherein the control unit (90) is preferably configured to initiate intermediate cleaning when the construction process provides for a rest phase, in particular a cooling phase. [15] System according to one of claims 12-14, wherein the control unit (90) is configured to initiate cleaning depending on a degree of contamination. [16] System according to one of claims 1-15, further comprising a sensor unit (76) with at least one contamination sensor (80), preferably an optical contamination sensor (82). [17] System according to claim 16, wherein the contamination sensor (80) is configured to optically detect the degree of coverage of a surface of the work space (18). [18] System according to claim 16 or 17, wherein the contamination sensor (80) is coupled to a light source (84). [19] Plant according to one of claims 1-18, further comprising a recovery unit (70) for recovering reusable building material from a extracted gas-particle mixture. [20] Methods for additive manufacturing, in particular using Direct Energy Deposition, comprising the following steps: - Provision of an additive manufacturing system (10, 110, 210, 310, 410), wherein the system (10, 110, 210, 310, 410) comprises the following: - a workroom (18), - an enclosure (16) that limits the workspace (18), - at least one order head (46) for dispensing a building material, wherein the at least one order head (46) is coupled to at least one supply line (48), - a handling device (24, 324) with a receiving device (40, 340), wherein the handling device (24, 324) can be operated in a construction mode and a cleaning mode of the system, and - an integrated cleaning system (60) with at least one cleaning head (62, 100), wherein at least one cleaning head (62, 100) is coupled to at least one suction line (66, 104), wherein at least one cleaning head (62, 100) is movable by the handling device (24, 324) in the work space (18) in order to clean at least the work space (18) or a component (58), - Operating the system (10, 110, 210, 310, 410) in a build mode, wherein the at least one application head (46) is moved by the handling device (24, 324) to produce an additive application onto a component (58), wherein the cleaning head (62, 100) is detached from the handling device (24, 324) in build mode and is in a park position, and - Operating the system (10, 110, 210, 310, 410) in a cleaning mode, wherein the at least one cleaning head (62, 100) is moved by the handling device (24, 324) to clean at least the work space (18) or a component (58), wherein the application head (46) is detached from the handling device (24, 324) in cleaning mode and is in a park position, wherein the lines (48, 66, 104) of the application head (46) and the cleaning head (62, 100) also remain connected in a respective park position of the application head (46) or the cleaning head (62, 100).

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