Apparatus for additively manufacturing components

Abstract

The invention relates to an apparatus for additively manufacturing components. The apparatus comprises one or more light sources for generating one light beam each and at least one processing head, which is movably mounted so that it can be moved at least over a portion of a processing region. Each processing head is designed to direct one of the light beams at a melting region, the melting region being a region of the processing region. The apparatus is characterized in that, on at least one processing head, a suction nozzle of a suction device is provided, which can be moved together with the processing head in order to provide suctioning in the melting region.

Description

[0001] Device for the generative manufacturing of components

[0002] The invention relates to a device for the generative manufacturing of components, in particular by means of selective laser melting or selective laser sintering.

[0003] Using generative manufacturing processes, it is possible to produce a wide variety of three-dimensional components with complex geometries, but also to process existing components.

[0004] The term generative manufacturing is also known as additive manufacturing, 3D printing, and rapid technology. It is a comprehensive term for all processes in which material is applied layer by layer and a three-dimensional component is created by melting and curing at least some of the layers. The entire manufacturing process is thus an interplay of physical and chemical melting and curing processes. The application of the layers is computer-controlled. The dimensions and shapes are usually designed using a CAD program.

[0005] Additive manufacturing is becoming increasingly important in industry and research. 3D printing is often used to produce models, samples, or initial prototypes. However, serial parts are also produced this way.

[0006] An example of a generative manufacturing process is selective laser melting or powder bed melting using a laser beam. In this process, thin layers (approximately 15-500 pm) of powder are applied to a base plate. This powder is then completely melted in small areas (locally) using laser radiation, and after solidification, forms a solid material layer. Once a layer has been completed for its intended purpose, a new layer of powder is applied and laser melted again. This process is repeated until the desired component is obtained. The remaining powder is then removed.

[0007] DE 10 2013 217 598 A1 relates to a device for laser material processing or a device for selective laser melting or laser sintering. The device comprises a laser for generating a laser beam and a laser head movable along at least one spatial direction. DE 10 2013 011 676 A1 discloses a device for additive component manufacturing, in particular for laser melting or laser sintering. The device comprises a processing head with which several separate laser beams can be directed adjacently and / or partially overlapping onto a processing plane.

[0008] DE 10 2020 128 028 A1 discloses a device for the additive manufacturing of components, in particular by means of selective melting or sintering. The device comprises a light source for generating a light beam and a processing head by means of which the light beam can be directed onto a processing area. The processing head is movably mounted so that the light beam can be directed to different locations within the processing area. Several processing heads are provided for directing a light beam onto the processing area, and the processing heads are each arranged on a carriage that can be moved along a crossbeam.

[0009] DE 10 2012 107 297 A1 describes a method for applying, curing, and surface processing powdered materials to build surfaces for the production of three-dimensional workpieces using laser radiation. The laser radiation is directed into a workspace above the build surface by means of a laser head. The build surface and / or the workpiece and / or the laser head or multiple laser heads can be moved, pivoted, or rotated in three dimensions.

[0010] WO 2016 / 150 559 A1 describes a device for 3D printing a workpiece. The device comprises a print head with a printing material nozzle, which ejects particles of a printing material and impinges on a working point. Furthermore, the device comprises a radiation source for generating a particle beam to melt the material particles and an extraction nozzle for extracting loose material particles.

[0011] The object of the present invention is to provide a device for the generative manufacturing of components which is of simple design and allows the production of components with a high quality.

[0012] One or more of the objects are achieved by a device for the additive manufacturing of components, as defined in independent patent claim 1. Advantageous embodiments of the device for the additive manufacturing of components are specified in the dependent subclaims.

[0013] According to the invention, a device for the additive manufacturing of components is provided. The device comprises one or more light sources, each for generating a light beam, and at least one processing head that is movably mounted so that it can be moved at least over a portion of a processing area. Each processing head is designed to direct one of the light beams onto a melting area, wherein the melting area is a portion of the processing area. An extraction nozzle of an extraction device is arranged on at least one processing head and is designed to be movable together with the processing head in order to extract material in the melting area.

[0014] The device is characterized in that the at least one processing head is arranged on a pivoting arm that can be pivoted over at least a portion of the processing area. The suction nozzle is a tubular body, and the tubular body has an opening at a front end that forms a nozzle opening. The tubular body is coupled to the pivoting arm in such a way that the nozzle opening is directed toward the melting area in order to suction locally in the melting area.

[0015] The device can be provided for the generative production of components, in particular by means of selective laser melting or selective laser sintering.

[0016] The processing area refers to the entire area in which the material to be melted is provided and can be melted. The at least one processing head can be designed such that it can reach every point in the processing area to melt the material there. Multiple processing heads can also be provided, covering at least a portion of the processing area.

[0017] The melting zone refers to a local portion of the processing area onto which the processing head directs the light beam to melt material. The melting zone encompasses the point onto which the light beam is directed, as well as a limited area around this point that is also influenced by the light beam.

[0018] In a generative manufacturing process, it is generally known to provide an extraction system to maintain a specific atmosphere in the processing area and to extract exhaust gases generated during the melting of the material. Typically, an inert gas atmosphere is provided in the processing area to prevent contamination by the exhaust gases generated during melting. In addition, dirt particles generated during the melting process can also be extracted. The exhaust gases and dirt particles are referred to collectively as "contaminants" below.

[0019] In general, the extraction takes place in such a way that a slot-shaped extraction nozzle is provided at an edge area of ​​the processing area, which extracts the processing area over at least a portion of the width or length of the processing area.

[0020] The inventors have recognized that, on the one hand, the contaminants that arise when the material is melted are drawn and distributed over the processing area and, in particular, are not completely extracted, and on the other hand, a large amount of non-contaminated atmosphere is also extracted, which must be replaced accordingly.

[0021] By positioning an extraction nozzle of an extraction system directly on the processing head, which can be moved along with the processing head, the contaminants can be extracted locally in the melting area. This eliminates the need for large-scale extraction, which would lead to undesirable side effects such as the dispersion of contaminants. At the same time, local extraction also reduces the amount of gas that must be extracted to remove the contaminants from the atmosphere. This also reduces the amount of fresh gas that must be introduced to maintain a constant atmosphere.

[0022] Because the extraction nozzle is located on the processing head, the contaminants are extracted locally at the point where they are generated by the melting process. They are thus removed from the atmosphere before they can disperse into it. This local extraction is particularly effective for extracting exhaust gases. Dirt particles can also be extracted if they enter the intake area of ​​the extraction nozzle.

[0023] It can be arranged to extract the material in the melting area, where the material has previously been melted using the light beam. When melting the material, exhaust gases and dirt particles, such as soot particles, are usually generated, which cannot be avoided. These can then be extracted locally immediately after melting.

[0024] With such local extraction, it is not necessary to provide a laminar gas flow across the entire processing area to remove contaminants. Typically, such a laminar gas flow is carried out at a speed of, for example, 2 m / s. The minimum speed is generally 1 m / s. The larger the processing area, the more difficult it is to maintain this minimum speed with a conventional gas flow system, which provides a laminar flow across the entire processing area. This is because the larger the processing area, the greater the differences in gas flow speed, and a maximum speed of 2.5 m / s should not be exceeded, otherwise the material to be welded, especially in the form of powder, will be entrained.

[0025] With local extraction, i.e. with such an arrangement of an extraction nozzle on the extraction device, these problems of conventional devices for the additive manufacturing of components are avoided. This allows such a device to be designed with any desired large processing area without the extraction of contaminants causing problems. The larger the processing area, the larger the components or the more components can be produced in a device for the additive manufacturing of components. There is therefore fundamentally considerable interest in designing such devices with a large processing area. However, the conventional extraction of exhaust gas has limited this, which is overcome with the present invention.

[0026] Since the extraction nozzle of the extraction system is located directly on the machining head, it is not an additional device that needs to be moved alongside the machining heads themselves. Each additional device that needs to be moved above the machining area complicates the machining process, as their travel path must also be coordinated to avoid collisions.

[0027] Furthermore, the positioning of the extraction nozzle does not need to be specified separately. The extraction nozzle is always positioned at the processing head and can extract material there immediately after the melting process.

[0028] The nozzle opening of the suction nozzle is directed towards the melting area in order to suction locally in the melting area.

[0029] If the nozzle opening of the extraction nozzle is directed toward the melting area, extraction occurs precisely in the melting area. Areas surrounding the melting area are thus barely affected by the extraction nozzle. This means that hardly any gas is unnecessarily drawn in from the atmosphere surrounding the melting area.

[0030] The nozzle opening can have a distance of maximum 5 cm or maximum 4 cm or maximum 3 cm or maximum 2 cm or maximum 1 cm from the melting area.

[0031] The closer the nozzle opening is to the melting zone, the smaller the extraction zone of the extraction nozzle. The extraction zone can be designed to be only slightly larger than the melting zone. This way, areas further away from the melting zone are barely affected by the extraction nozzle.

[0032] The extraction area may comprise an area enclosing a circle with a radius not larger than 5 cm, not larger than 3 cm, or not larger than 2 cm, so that the extraction area does not extend far beyond the melting area.

[0033] The at least one processing head is arranged on a pivoting arm which can be pivoted over at least a section of the processing area. Such an arrangement of the processing head has the advantage that a light beam emitted by the processing head, in particular a laser beam, can always be aligned with the same inclination to the processing plane (= powder bed). In particular, the light beam or the laser beam can always be aligned perpendicular to the processing plane. The extraction nozzle can be coupled to the pivoting arm and designed to be pivotable together with the pivoting arm such that the pivoting arm and the extraction nozzle are pivoted together. As a result, the extraction nozzle is always aligned with the melting area. The extraction nozzle can be arranged on the pivoting arm itself or on a pivot joint of the pivoting arm.

[0034] The suction nozzle is a tubular body and the tubular body has an opening at a front end which forms the nozzle opening, wherein the tubular body is coupled to the pivot arm in such a way that the nozzle opening is directed towards the melting area in order to suction locally in the melting area.

[0035] By designing the extraction nozzle as an elongated tubular body, the nozzle opening can be directed very precisely to a small area of ​​the processing area. If the cross-section of the nozzle opening is designed to be correspondingly small, precise extraction can be achieved in a very small area.

[0036] If the tubular body is coupled to the swivel arm, the extraction nozzle always pivots along with the processing head. This allows the nozzle opening to always be directed toward the melting area and always maintain the same distance from the melting area. There is no need to move a separate extraction nozzle and / or coordinate it with the processing head.

[0037] The tubular body is preferably made of a lightweight material, such as plastic, especially fiber-reinforced plastic. If the tubular body is made of a lightweight material, it has only a low inertia, which means a minimal impact on its pivotability.

[0038] The tubular body may have a light beam opening adjacent to the nozzle opening through which the light beam of the processing head is directed.

[0039] If the extraction nozzle or tubular body has a light beam aperture adjacent to the nozzle opening, the extraction nozzle can cross the path of the light beam, allowing it to be longer than an extraction nozzle without a light beam aperture. This allows the nozzle aperture to be positioned closer to the melting area. This allows for very precise extraction in a small area using the nozzle aperture.

[0040] With this configuration, it is fundamentally possible for extraction to occur simultaneously during the melting process. Furthermore, a method according to the invention for the additive manufacturing of components is provided. Here, at least one light beam is directed into a processing area in order to melt powdery material present in the processing area. The area in which the light beam impinges on the powdery material is referred to as the melting area. By means of an extraction nozzle arranged adjacent to the melting area, exhaust gas and / or dirt particles or contaminants are / are locally extracted in the melting area.

[0041] The method is characterized in that the suction nozzle is a tubular body and the tubular body has an opening at a front end which forms a nozzle opening, wherein the nozzle opening is directed towards the melting area in order to suction locally in the melting area

[0042] An extraction area formed by the extraction nozzle can cover the melting area and extend only slightly beyond the melting area.

[0043] If the extraction area covers the melting area or extends only slightly beyond the melting area, then gas that is located around the melting area but has not been affected by the melting process will not be sucked in unnecessarily.

[0044] Several melting areas can be created using several light beams, with each melting area being assigned an extraction nozzle to extract exhaust gases or contaminants from the respective melting area.

[0045] Multiple light beams, which create multiple melting zones in parallel, allow components to be manufactured faster or larger without having to move a single light beam over a large area. Using the extraction nozzles assigned to each melting zone, local extraction can be achieved at each melting zone. This allows such a setup to be scaled up as required without the technical difficulties associated with large-area extraction systems.

[0046] In this process, the device described above can be used for the generative manufacturing of components.

[0047] The advantages described above with reference to the device for the generative manufacturing of components apply analogously to the method according to the invention for melting a material with such a device.

[0048] Further objects, features and advantages of the present invention will become apparent from the description and the exemplary embodiment shown in the attached figures. These show: Figure 1 is a schematic representation of an apparatus according to the invention for the additive manufacturing of components in a plan view, in

[0049] Figure 2 is a perspective view of a swivel arm with a suction device, in

[0050] Figure 3 is a further perspective view of the swivel arm with the suction device, in

[0051] Figure 4 is a further perspective view of the swivel arm with the suction device, in

[0052] Figure 5 is a perspective view of the swivel arm with the suction device and a pipe arranged on the suction device, in

[0053] Figure 6 is a further perspective view of the swivel arm with the suction device and the pipe arranged on the suction device, and in

[0054] Figure 7 shows a further perspective view of the swivel arm with the suction device and the pipe arranged on the suction device.

[0055] The following describes in more detail a device 1 for the additive manufacturing of components (Fig. 1) according to an embodiment of the invention (Figs. 2 to 7). The device 1 is intended, in particular, for the additive manufacturing of components by means of selective laser melting or selective laser sintering.

[0056] An inert gas atmosphere is provided in the device 1. Nitrogen and / or argon are particularly used as the inert gas. The use of an inert gas atmosphere can prevent oxidation of the material to be melted or the component during component production.

[0057] The device 1 comprises a processing area 2 and a storage area 3. The processing area 2 is a powder bed in which a component can be manufactured. In the storage area 3, powder is provided for the processing area 2. The powder is the starting material from which the component is manufactured by melting. For each melting process, the powder is transferred from the storage area 3 to the processing area 2 to be melted there.

[0058] In the following, the storage area 3 is referred to as a vertically upper area of ​​a storage cylinder 4 in which the powder is stored. In a plan view, the storage cylinder 4 is designed as a rectangular body. Arranged in the storage cylinder 4 is a storage piston (not shown), which can be raised or lowered vertically by means of a first lifting / cylinder unit. The processing area 2 is likewise a vertically upper area of ​​a processing cylinder 5. In a plan view, the processing cylinder 5 is also designed as a rectangular body. In the processing cylinder 5, a processing piston (not shown) is mounted for vertical displacement and can be actuated by means of a second lifting / cylinder unit.

[0059] The storage area 3 and the processing area 2 are arranged adjacent to each other. A doctor blade 6 is provided, which can be moved in a direction of movement 7 such that the powder stored in the storage cylinder 4 can be spread into the processing cylinder 5. The doctor blade 6 thus transfers a surface layer of powder from the storage cylinder 4 to the processing area 2.

[0060] By gradually raising the storage piston and gradually lowering the processing piston, the surface of the powder in the storage cylinder 4 and in the processing cylinder 5 can be kept at approximately the same level.

[0061] In an area above the processing area 2, a moving device 8 for moving a processing head 9 is provided.

[0062] The movement device 8 comprises a traverse 11, by means of which the processing head 9 can be moved over the processing area 2 in such a way that each point on the processing area 2 can be processed by means of the processing head 9.

[0063] For this purpose, two stationary rails 10 are provided, which extend lengthwise along the direction of movement 7. The cross member 11 is arranged transversely to the rails 10 and is mounted with its end points on the rails 10 by means of carriages 13. Thus, the cross member 11 can be moved along the rails 10 in the direction of movement 7.

[0064] An elongated pivot arm 15 is arranged on the cross member 11, at the end of which the machining head 9 is arranged remote from the cross member 11. The pivot arm 15 is arranged on the cross member 11 by means of a carriage 14 and can thus be moved along the cross member 11 in a direction of movement 12 transverse to the direction of movement 7, i.e., parallel to the rails 10.

[0065] The cross member 11 and the rails 10 each have an approximately rectangular cross-section with a rail profile (not shown). The rail profile extends over the entire length of the cross member 11 and the rails 10.

[0066] The carriages 13, 14 are arranged on the rail profiles of the crossbeam 11 and the rails 10. The carriage 14 is mounted so as to be displaceable in the longitudinal direction of the crossbeam 11, and the carriages 13 are mounted so as to be displaceable in the longitudinal direction of the rails 10. The carriages 13, 14 can be moved automatically along the crossbeam 11 or the rails 10 by means of a drive device (not shown). The drive device can comprise a drive belt driven by an external motor, which is coupled to the respective carriage 13, 14. However, a drive mechanism, such as a drive wheel driven by a motor, can also be provided in the carriage 13, 14 itself. In principle, it is also possible to drive the carriages 13, 14 by means of a linear motor, in which case the corresponding drive means and drive countermeasures must be provided on the carriages 13, 14 and on the crossbeam 11 or the rails 10.

[0067] The carriage 14 of the traverse 11 has a pivot joint 16, to which the pivot arm 15 is mounted by means of a pivoting device 19. The pivot arm 15 is mounted rotatably about a vertical pivot axis 17 by means of the pivot joint 16. A stepper motor (not shown) is provided on the carriage 14 for rotating the pivot arm 15 about the pivot axis 17.

[0068] The machining head 9 is located at the end of the swivel arm 15 remote from the swivel joint 16. The machining head 9 can be pivoted over the machining area 2 by means of the swivel joint 16.

[0069] The pivot arm 15 is designed to guide a light beam 18, generated by a light source (not shown), to the processing head 9. For this purpose, the pivot arm 15 has a cavity in its interior through which the light beam 18 passes to the processing head 9.

[0070] The swivel arm 15 is a hollow plastic tube, specifically made of fiber-reinforced plastic. Such a plastic tube is lightweight yet stable. The swivel arm 15 itself is lightweight and therefore has low inertia, allowing it to be swiveled quickly and precisely.

[0071] A mirror 28 is provided on the processing head 9, which directs and focuses the light beam 18 onto a melting area 27. The melting area 27 is a sub-area of ​​the processing area 2. The pivoting arm 15 can also comprise further optical elements, such as mirrors and lenses, which are adjustable, in particular, for adjusting the focal point.

[0072] The light source can be arranged in a region of the carriage 14 on the pivot arm 15 or in a region of the carriage 14 inside the pivot arm 15 or on the carriage 14 itself or also remotely from the carriage 14.

[0073] The pivot arm 15 is designed such that the light beam 18 is reliably guided to the processing head 9 even when the pivot arm 15 moves along the crosshead 11 and / or rotates about the pivot joint 16. It can also be provided that the light source is arranged some distance from the pivot arm 15 and the light beam 18 is guided to the pivot arm 14, for example, by means of a light guide. For this purpose, the pivot joint 16 has a corresponding through-opening.

[0074] It can also be provided that the light source is arranged directly on the processing head 9 and the light beam bundle 18 is directed directly from the light source onto the melting area 27.

[0075] The light source is preferably a laser, in particular a CO2 laser, an Nd:YAG laser, or a fiber laser. The light source can also be a semiconductor laser or a light-emitting diode, in particular a superluminescent light-emitting diode.

[0076] The light source can be switched on or off, so that the generation of the light beam 18 can be started or stopped almost instantly. A diaphragm can also be provided on the path of the light beam 18 from the light source to the mirror 28, which can interrupt the path of the light beam 18.

[0077] A suction nozzle 20 is provided on the pivoting mechanism 19 of the pivoting arm 15, facing the processing area 2. The suction nozzle 20 is an elongated tube, with a rear end 21 fixedly mounted on the pivoting arm 15 in a region of the pivoting mechanism 19. The suction nozzle 20 is arranged at an angle relative to the pivoting arm 15, so that a front end 22 of the suction nozzle 20 is located near the processing area 2. The suction nozzle 20 is approximately the length of the pivoting arm 15.

[0078] At its front end 22, the suction nozzle 20 has a nozzle opening 23 directed toward the processing area 2. A volume flow is sucked in through the nozzle opening 23, creating a suction effect in the direction of the nozzle opening 23. This allows a local suction to be applied to a location in the processing area 2 in an area in front of the nozzle opening 23.

[0079] The suction nozzle 20 can be chamfered in the area of ​​the nozzle opening 23, whereby a vertically upper side of the suction nozzle 20 covers the nozzle opening 23.

[0080] Like the swivel arm 15, the suction nozzle 20 can be a hollow plastic tube, particularly made of fiber-reinforced plastic. Such a plastic tube is lightweight yet stable. The suction nozzle 20 itself also has a low weight and thus low inertia, allowing it to be swiveled quickly and precisely together with the processing head 9.

[0081] In the area of ​​the front end of the extraction nozzle 20, it has a light beam opening 24 on a vertically upper side. The light beam 18 is guided through the light beam opening 24 from the processing head 9 towards the processing area 2. The light beam opening 24 is designed to be large enough that the light beam 18 can pass through without touching the edge of the light beam opening 24 or heating it up too much. The light beam opening 24, in turn, is designed to be small enough that no or only a small amount of gas is sucked in through it. The length of the extraction nozzle 20 and the angle of the extraction nozzle 20 with respect to the pivot arm 15 are adjusted such that the light beam 18 is guided through the light beam opening 24 at all times to strike the melting area 27, and that suction is simultaneously carried out in the melting area 27 by means of the nozzle opening 23.

[0082] With this configuration, the extraction nozzle 20 can be longer than the pivot arm 15, and the nozzle opening 23 of the extraction nozzle 20 can be directed not only directly at the melting area 27, but also during the melting process. This allows extraction during and / or immediately after the melting process. This allows the extraction of exhaust gases and dirt particles that arise during the melting of the powder. Thus, the exhaust gases and dirt particles hardly contaminate the inert gas atmosphere, as they are extracted before they can disperse into the atmosphere.

[0083] Preferably, the swivel arm 15 and the suction nozzle 20 are designed in terms of weight and stability so that they can be moved quickly and precisely. They are also preferably designed so that they move as little as possible relative to each other. The swivel arm 15 and the suction nozzle 20 should move as synchronously as possible.

[0084] An additional mechanical connection, such as one or more struts (not shown), can be provided between the swivel arm 15 and the suction nozzle 20. These struts ensure that the distance between the swivel arm 15 and the suction nozzle 20 remains very constant.

[0085] To generate the volume flow of the suction nozzle 20, the suction nozzle 20 is connected to a suction device (not shown). The suction device comprises all parts necessary to provide a volume flow at the nozzle opening 23 of the suction nozzle 20.

[0086] For this purpose, the suction device has a pipe or flexible hose 25 (Figs. 5 to 7) that directs the volume flow to the suction nozzle 20. The suction nozzle 20 is connected to the pipe / hose 25 in a region of the pivoting device 19. The volume flow is directed via the pipe or hose 25 and the suction nozzle 20 to the nozzle opening 23.

[0087] A switchable valve (not shown) can be provided, by means of which the volume flow on the path from the extraction device to the nozzle opening 23 can be diverted or interrupted almost instantaneously. This allows the extraction device to operate continuously, and by opening the valve, the gas is drawn in from the environment and not, or only to a very small extent, from the extraction nozzle 20. The valve can, in principle, be provided at any position on the path from the extraction device to the nozzle opening 23. Preferably, the valve is provided as close as possible to the nozzle opening 23 so that the volume flow at the melting area 27 can be quickly stopped and restarted. Furthermore, the valve is arranged outside the inert gas atmosphere of the device 1 for additive manufacturing or is connected to a pipe / hose 25 leading out of this atmosphere, so that it is not extracted when the valve is open.

[0088] In a further embodiment, multiple processing heads 9 can be provided on the traverse 11. The processing heads 9 can be moved independently and parallel to one another and can simultaneously melt material at different points in the processing area 2. It can be provided that each of the processing heads 9 has its own light source for providing a light beam 18. It can also be provided that a light beam 18 is provided to all processing heads 9 by means of one light source.

[0089] In a further embodiment, several crossbeams 11 with one or more processing heads 9 can be provided, which can be moved independently and parallel to one another. The several crossbeams 11 can then be designed to be movable themselves or be provided as stationary crossbeams 11.

[0090] In a further embodiment, a light guide can be arranged inside the pivot arm 15, which guides the light beam 18 approximately from the pivoting device 19 to approximately the processing head 9. The light guide 19 can be formed from a flexible optical fiber. The optical fiber can be, for example, a glass fiber or a polymer optical fiber. A movable optical lens can be provided on the processing head 9, which directs and focuses the light beam 18 onto the melting region 27.

[0091] In an alternative embodiment, the suction nozzle 20 can be designed to be movable independently of the pivot arm 15. For this purpose, a pivot joint specifically provided for the suction nozzle 20 can be arranged on the pivot device 19 of the pivot arm 15, on which the suction nozzle 20 is arranged. Likewise, the suction nozzle 20 can be provided with a pivot device 19, by means of which it is arranged on a pivot joint arranged adjacent to the pivot joint 16 of the pivot arm 15. In this case, a stepper motor can be provided for rotating the suction nozzle 20 about a pivot axis of the respective pivot joint.

[0092] In a further embodiment, the front end 22 of the extraction nozzle 20 can be an annular nozzle opening 26 (Figs. 5 to 7). The annular nozzle opening 26 forms the nozzle opening 23 through which suction takes place in the processing area 2. The annular nozzle opening 26 is annular and thus covers a larger extraction area. The larger nozzle opening generates lower local flow velocities. At the same time, the annular nozzle opening 26 has an exposed center, which forms the light beam opening 24 and through which the light beam 18 is guided to the processing area 2.

[0093] Furthermore, a method according to the invention for melting a powder with a device 1 for the generative production of components, as explained above with reference to the exemplary embodiment, is provided.

[0094] The powder is provided in a storage area 3. The storage area 3 is the vertically upper area of ​​a storage cylinder 4 in which the powder is stored.

[0095] Using a doctor blade 6, a surface layer of powder is spread from the storage area 3 into an adjacent processing area 2. The processing area 2 is the upper vertical area of ​​a processing cylinder 5. The processing area 2 is a powder bed.

[0096] A light source (not shown) generates a light beam 18 and guides it to a processing head 9. The processing head 9 is mounted on a pivoting arm 15 and can be pivoted over the processing area 2 by means of the pivoting arm 15 such that it can reach every point of the processing area 2 with the light beam 18. For this purpose, the pivoting arm 15 is movably mounted on a cross member 11. The cross member 11 is also designed to be movable.

[0097] Using the processing head 9, the light beam 18 is focused on a melting area 27 of the powder layer in processing area 2 in order to melt the powder in the melting area 27. Only those areas of the powder bed necessary for producing the component are melted. To ensure this functionality, the light beam 18 can be switched on and off as required. This allows the processing head 9 to be moved without the light beam 18 being emitted at these times. The light beam 18 is only emitted when the processing head 9 has reached a position where the powder is to be melted.

[0098] During and / or immediately after the melting process, an extraction nozzle 20, which is arranged on a pivoting device 19 of the pivoting arm 15, is used to extract material from the melting area 27. For this purpose, a nozzle opening 23 of the extraction nozzle 20 is directed toward the melting area 27. A volume flow is provided at the nozzle opening 23, which has a suction effect toward the melting area 27. This extracts exhaust gases and dirt particles, such as soot particles, that are generated during the melting process.

[0099] By means of an automatically switchable valve, the volume flow to the nozzle opening 23 can be interrupted at any time, so that extraction can only take place during and / or immediately after the melting process. After all areas of the powder layer necessary to produce the component have been melted, a new layer of powder is spread from the storage area 3 into the processing area 2 using the doctor blade 6. By gradually raising or lowering the storage cylinder 4 and the processing cylinder 5, the surface of the powder in the storage cylinder 4 and the processing cylinder 5 can be kept at approximately the same level.

[0100] List of reference symbols

[0101] 1 device

[0102] 2 Editing area

[0103] 3 Storage area

[0104] 4 storage cylinders

[0105] 5 processing cylinders

[0106] 6 squeegees

[0107] 7 Direction of movement

[0108] 8 Traversing device

[0109] 9 Processing head

[0110] 10 rail

[0111] 11 Traverse

[0112] 12 Direction of movement

[0113] 13 sleds

[0114] 14 sleds

[0115] 15 Swivel arm

[0116] 16 Swivel joint

[0117] 17 Swivel axis

[0118] 18 light beams

[0119] 19 Swivel device

[0120] 20 suction nozzle

[0121] 21 rear end

[0122] 22 front end

[0123] 23 Nozzle opening

[0124] 24 light beam aperture

[0125] 25 pipe

[0126] 26 Ring nozzle opening

[0127] 27 Melting range

[0128] 28 mirrors

Claims

Claims 1. Device (1) for the generative manufacturing of components, comprising one or more light sources for each generating a light beam (18), and at least one processing head (9) which is movably mounted so that it can be moved at least over a section of a processing area (2), wherein each processing head (9) is designed to direct one of the light beams (18) onto a melting area (27), wherein the melting area (27) is a region of the processing area (2), wherein an extraction nozzle (20) of an extraction device is arranged on at least one processing head (9), which is designed to be movable together with the processing head (9) in order to extract material in the melting area (27), characterized in that the at least one processing head (9) is arranged on a pivoting arm (15),which is pivotable over at least a portion of the processing area (2) and the suction nozzle (20) is a tubular body and the tubular body has an opening at a front end (22) which forms a nozzle opening (23), wherein the tubular body is coupled to the pivot arm (15) such that the nozzle opening (23) is directed towards the melting area (27) in order to suck out gas locally in the vicinity of the melting area (27).

2. Device according to claim 1, characterized in that the nozzle opening (23) has a distance of maximum 5 cm or maximum 4 cm or maximum 3 cm or maximum 2 cm or maximum 1 cm from the melting area (27).

3. Device according to claim 1 or 2, characterized in that the suction nozzle (20) acts on a suction area, wherein the suction area comprises an area which encloses a circle with a radius which is not larger than 5 cm or not larger than 3 cm or not larger than 2 cm.

4. Device according to one of claims 1 to 3, characterized in that the pivoting arm (15) is formed by a hollow tube, wherein a hollow space is formed in the interior of the tube through which the light beam bundle (18) reaches the processing head (9).

5. Device according to claim 4, characterized in that the pivot arm (15) is a hollow plastic tube, in particular made of a fiber-reinforced plastic.

6. Device according to one of claims 1 to 5, characterized in that a light guide is arranged in the interior of the pivoting arm (15), which guides the light beam bundle (18) to the processing head (9).

7. Device according to one of claims 1 to 6, characterized in that a switchable closure device is provided in the region of the nozzle opening (23), by means of which a volume flow from a suction device to the nozzle opening (23) can be deflected or interrupted.

8. Device according to one of claims 1 to 7, characterized in that the tubular body is made of a plastic, in particular of a fiber-reinforced plastic.

9. Device according to one of claims 1 to 8, characterized in that the tubular body in the region of the nozzle opening (23) has a light beam opening (24) through which the light beam bundle (18) of the processing head (9) is directed.

10. A method for the generative production of components, wherein at least one light beam (18) is directed into a processing area (2) in order to melt powdery material present in the processing area (2), wherein the area in which the light beam (18) impinges on the powdery material is referred to as the melting area (27), wherein exhaust gas is sucked off locally in the melting region (27) by means of an extraction nozzle (20) which is arranged adjacent to the melting region (27), characterized in that the extraction nozzle (20) is a tubular body and the tubular body has an opening at a front end (22) which forms a nozzle opening (23), wherein the nozzle opening (23) is directed in the direction of the melting region (27) in order to suck off gas locally in the vicinity of the melting region (27).

11. The method according to claim 10, characterized in that a suction region formed by the suction nozzle (20) covers the melting region (27) and extends only slightly beyond the melting region (27).

12. Method according to claim 10 or 11, characterized in that a plurality of melting regions (27) are produced with a plurality of light beam bundles (18), wherein each melting region (27) is assigned a suction nozzle (20) with which exhaust gas is sucked off at the respective melting region (27).

13. Method according to one of claims 10 to 12, characterized in that a device (1) according to one of claims 1 to 9 is used.

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