Machine tool and flow guiding device

Abstract

The invention relates to a machine tool (100) for the layer-by-layer additive construction of a workpiece, comprising a processing chamber (10) in which the additive construction of the workpiece is carried out; a process gas device (40) arranged to introduce a process gas flow (41) into the process chamber (10) during additive construction, and a flow guide element (51) for the process gas flow (41), which is fastened within the process chamber (10) and which is elastically deformable between a first position in which the process gas flow (41) is introduced into the process chamber (10), and a second position in which the process gas flow (41) is introduced into the process chamber (10), the flow guide element (51) has a first position, in which the flow guide element (51) has a first outer contour geometry, and a second position, in which the flow guide element (51) has a second outer contour geometry that differs from the first outer contour geometry.

Description

Technical Field

[0001] The invention relates to a machine tool for additive layered construction of a workpiece and to a flow guide device for use in the machine tool. Background Art

[0002] Known from the prior art are predominantly forming methods for the additive manufacturing of three-dimensional workpieces, in which the workpiece is built up layer by layer from a provided material.

[0003] For this purpose, the powder material is usually applied as a material layer to a carrier located in a process chamber of the machine tool and then solidified by location-specific irradiation to form the workpiece layer, for example by melting or sintering individual material particles of the material layer.

[0004] If the workpiece layer is cured, a new material layer of untreated material is applied to the carrier or the already produced workpiece layer and a new, site-specific irradiation takes place.

[0005] In this way, the workpiece is built up successively layer by layer from a plurality of material layers applied to a carrier.

[0006] In the course of this manufacturing process, undesired influences often occur which have a negative effect on the process conditions within the process chamber and thus ultimately also on the manufacturing quality.

[0007] Thus, on the one hand, the process space defined by the process chamber is loaded with impurities, for example by exhaust gases arising during the curing process or by vortices of uncured material. On the other hand, the process space is continuously heated by the waste heat generated during the irradiation process, which can, for example, lead to thermally induced deformations of individual components within the process chamber.

[0008] In order to counteract these negative effects and to provide substantially constant and optimal process conditions during the manufacturing process, a process gas flow is usually conducted through the process chamber, via which, for example, the impurities or the waste heat occurring are discharged from the process chamber.

[0009] In this case, however, the process gas flow itself may be the source of undesirable effects, such that it swirls, for example, uncured material on the carrier, which not only contaminates the processing space itself but also leads to inhomogeneities in the applied material.

[0010] In order to counteract this, the process gas flow and the process chamber are synchronized with each other in order to thereby provide, for example, a process gas flow that is as laminar as possible and without swirls. In particular, this synchronization is made more difficult by other components of the machine tool located in the process chamber (e.g. a movable coater for applying the material to the carrier), where undesired swirls may occur.

[0011] From EP 3 928 900 A1, for this purpose, a machine tool with a movable coater is known, wherein the process chamber has a substantially cuboid design, wherein a plurality of planar side walls extend parallel to the introduction direction of the process gas flow introduced into the process chamber, so that the process gas flow can flow substantially along these planar elements without swirls in the process. In order to eliminate the coater movable in the process chamber as a source of undesirable swirls, after the material has been applied to the substrate-side carrier, the coater is moved out of the process chamber via an opening in the side wall that can be closed by a flap.

[0012] This solution requires a design of the entire process chamber designed for the process gas flow, which has essentially purely planar boundary surfaces for guiding the process gas flow. As a result, on the one hand, the developer's design freedom is greatly restricted, and on the other hand, other components can hardly be retrofitted in the process chamber, because these components would cause disturbances in the process gas flow. Optical systems for monitoring the manufacturing process, lighting elements for monitoring and controlling the manufacturing process or other sensors / actuators can be mentioned as examples of such components. Summary of the invention

[0013] It is therefore an object of the present invention to provide an efficient possibility for targeted guidance of a process gas flow through a process chamber of a machine tool provided for additive manufacturing, which can be easily adapted to a variable configuration of the machine tool.

[0014] To achieve this object, a machine tool according to claim 1 and a flow guiding device according to claim 20 are provided.

[0015] The dependent claims relate to preferred embodiments, which can be provided individually or in combination.

[0016] According to a first aspect of the present invention, a machine tool for additive layered construction of a workpiece is provided, the machine tool comprising a processing chamber, in which additive manufacturing of the workpiece is performed, a process gas device, the process gas device being configured to introduce a process gas flow into the processing chamber during additive manufacturing; and a guide element for the process gas flow, the guide element being fastened in the processing chamber and being elastically deformable between a first position and a second position, the guide element having a first external contour geometry in the first position, and a second external contour geometry different from the first external contour geometry in the second position.

[0017] The flow-guiding element serves here to guide the process gas flow introduced at the inlet in a targeted manner through the process chamber as far as the outlet, as laminar a flow as possible without swirls or the like of the process gas flow.

[0018] For this purpose, at least in the first position of the flow-guiding element, one or more sections of the outer contour of the flow-guiding element form one or more flow boundary surfaces for a process gas flow flowing through the process chamber, along which the process gas flow is guided from the inlet into the process chamber as far as the outlet. The outer contour geometry here refers to the geometric shape of the outer contour.

[0019] Further flow-bounding surfaces can be formed here by the side surfaces / ceiling or base elements of the process chamber.

[0020] The flow guide element fastened in the processing chamber thus establishes a flow boundary surface for the process gas flow, which flow boundary surface is different from the internal contour of the processing chamber, so that the process gas flow can be guided in a targeted manner through a partial area of ​​the processing space bounded by the processing chamber (the internal space of the processing chamber).

[0021] Geometries, elements or components of the machine tool in the treatment region which cause disturbances in the process gas flow can thus be separated from the process gas flow by the flow-guiding element.

[0022] The elastic deformability of the flow-guiding element according to the invention, whose outer contour can thus be transformed between a first outer contour geometry and a second outer contour geometry, allows the flow-guiding element to be adapted to changing boundary conditions in the process region, so that the process gas flow can always be optimally guided through the process chamber. Among examples of changing boundary conditions, mention may be made of traversing (i.e. moving) parts of a machine tool during the manufacturing process.

[0023] The deformation between the first and second position is significant here, so that the deformation can be, for example, more than 2%, preferably more than 5% and even more preferably more than 20% relative to the length or width of the cross section of the flow guide element serving as flow boundary surface.

[0024] In a preferred embodiment, the flow guiding element is designed such that the first outer contour geometry corresponds essentially to a planar surface.

[0025] In this way, a geometry is provided which remains particularly simple for guiding the process gas flow and which, in contrast to any curved surfaces, does not lead to any swirls.

[0026] In a preferred embodiment, the flow guide element is arranged in the first position such that the planar surface extends parallel to the introduction direction of the introduced process gas flow.

[0027] Parallel is understood here to mean that the direction vector of the introduction direction runs orthogonally to the normal vector of the planar surface.

[0028] In this way, the flow guide element is only subjected to thrust forces of the parallel-flowing process gas flow (caused by thrust stresses in the fluid, ie in the process gas flow), as opposed to the process gas flow impinging at an angle and coming from the inlet, which means lower loading of the flow guide element.

[0029] Alternatively, however, the flow guide element can also be designed so that the planar surface is angled with the introduction direction. In this case, the flow guide element can even be used as a deflection element in order to correct the direction of the introduced process gas flow, for example in order to compensate for component-related inaccuracies, in particular inaccuracies of the inlet.

[0030] Therefore, the first position should not be limited to a parallel arrangement, but can also be arranged at an angle to the introduction direction so that the normal vector and the direction vector of the introduction direction are at an angle of 30 degrees to less than 90 degrees, preferably 45 degrees to less than 90 degrees and particularly preferably 70 degrees to less than 90 degrees to each other.

[0031] The angle is preferably adjustable via an adjustable support device, via which the flow guide element is fastened in the process chamber.

[0032] In particular, the support device is attached to a top element of the process chamber and comprises a mounting element for mounting on the top element and a holding element connected to and adjustable relative to the mounting element, and a flow guide element fastened to the holding element.

[0033] Guide devices may preferably be provided on side elements of the process chamber, in which one or more end sections of the flow guide element are guided, in particular such that they are guided in a translationally displaceable manner in one displacement direction.

[0034] Thereby, additional support of the flow guide element is provided, so that a more stable fastening is present in the process chamber, which additionally does not hinder or block the movement possibilities of the flow guide element which may optionally be provided.

[0035] In a preferred embodiment, the flow guiding element is a flexible surface element.

[0036] A surface element is understood to mean an element whose geometrical dimensions in the thickness direction (thickness) are preferably smaller than the dimensions in the width and longitudinal directions (width and length).

[0037] It is preferably a thin surface element, in which the ratio of thickness to width or thickness to length is less than or equal to 10%, preferably less than 5%, more preferably less than 1% and particularly preferably less than 0.1%.

[0038] Flexible is understood here to mean that the bending stiffness for bending deformations of the surface element in the thickness direction is lower than the tensile stiffness in the longitudinal or width direction.

[0039] For the comparability of bending stiffness and tensile stiffness with respect to different SI units, bending stiffness can be understood to mean the stiffness of the surface element which describes the restoring force which counteracts an individual force acting in the thickness direction on a reference point of the surface element. The reference point is preferably placed in the central region of the surface element rather than in the edge region in order to thereby obtain a suitable reference value for the bending stiffness.

[0040] The ratio of the bending stiffness to the tensile stiffness of the surface element in the longitudinal or width direction is preferably less than 25%, preferably less than 10%, more preferably less than 5% and particularly preferably less than 1%.

[0041] As a result of the embodiment as a flexible surface element, the flow guide element can be deformed in a bending manner particularly simply and without great expenditure of force, which is particularly advantageous for deformation from a first position to a second position (or vice versa). On the other hand, the stiffness parallel to the surface serving as flow boundary surface is very large and deformation due to shearing of the process gas flow is therefore very small.

[0042] Therefore, the flow guiding element is preferably deformable by bending deformation between a first position and a second position.

[0043] In a preferred embodiment, the flexible surface element is a membrane element or a woven element.

[0044] In this way, the flow guide element can be produced particularly cost-effectively.

[0045] The membrane element may be a metal membrane or a plastic membrane.The woven element may be woven, for example, from a braid or knit of fabric, plastic, carbon fiber or metal fiber.

[0046] The sheet metal element can be a thin sheet metal such as aluminum or a steel alloy, in particular a spring steel strip. In this way, a particularly resistant flow guide element can be provided.

[0047] In a preferred embodiment, the flow guide element in the first position divides the interior space of the process chamber into a first area and a second area, wherein the first area is a process area in which additive manufacturing is performed, and wherein the process gas device is configured to introduce a process gas flow into the first area.

[0048] In this way, the division of the process chamber can be carried out particularly simply, in which the process area can be geometrically optimally adapted to the process gas flow, independently of the size of the process chamber. Furthermore, in this way, an area separate from the process area is provided in which a plurality of components of the machine tool can be arranged which otherwise, that is to say without the division, would have a negative influence on the process gas flow. This can include, for example, additional sensor devices or filling devices for the material to be applied in layers, etc.

[0049] If the flow guide element is designed as a film element, it is preferably transparent (or translucent) and the beam path can therefore penetrate it (mostly) unhindered. Thus, for example, a machine operator can see the first area (processing area) through the flow guide element in order to track production there.

[0050] In a preferred embodiment, the building region of the machine tool in which the layered construction takes place is arranged completely in the first region.

[0051] Therefore, almost all impurity sources (swirling material, exhaust gas, combustion products) are arranged in the area where the process gas flow flows through, and these areas can be reliably discharged by the process gas flow. In addition, the parts of the machine tool arranged in other areas are isolated from impurities.

[0052] In a preferred embodiment, the process chamber comprises a lateral shell element, a top shell element and a bottom shell element, wherein the shell elements and the flow-guiding element are arranged relative to one another such that in a first position of the flow-guiding element, an introduced process gas flow flows as a parallel flow along the flow-guiding element through a first region of the interior space of the process chamber.

[0053] Thus, possible vortex sources in the first region of the interior space are minimized, so that particularly stable flow conditions are achieved. In this way, the vortex or vortices, if they occur, decay relatively quickly again.

[0054] In a preferred embodiment, the machine tool comprises a coating device, which is movable between a first end position and a second end position relative to the process chamber, is arranged to apply a layer of material for additive manufacturing to a building area of ​​the machine tool in the process chamber, and is further arranged to elastically deform the guide element between the first position and the second position by movement.

[0055] Thus, a coating device which is usually provided for applying a material layer can be used as a component of a machine tool, which coating device is movable relative to the building area in the process chamber, without the coating device representing an element which interferes with the process gas flow in its end position. Here, the flow guide element serves as a variable or passively adjustable separation element in the process chamber, wherein the adjustment movement in this case is caused by the coating device. Thus, the coating device can be moved through the first area of ​​the process chamber without having to provide a complex separation element with its own drive in order to allow the separation element to enter or leave the first area.

[0056] The coating device can thus displace the air guide element in a reversible manner during its movement in order to thereby achieve, for example, an end position outside the first region, without having to move the air guide element itself via a drive or the like.

[0057] In a preferred embodiment, when the coating device is in its first end position, the air guide element is brought into the second position, wherein the air guide element here at least partially bears against the coating device, in particular partially nests against its outer contour.

[0058] In this way, the coating device and the flow-guiding element terminate flush with one another in the second position, so that the first region and the second region within the process chamber itself are separated from one another in a relatively close manner in the second position.

[0059] In a preferred embodiment, a side surface of the coating device forms a control surface for the introduced process gas flow in the first end position.

[0060] The coating device itself thus serves as a type of flow-guiding element for the process gas flow, so that, among other things, additional material that would otherwise be provided separately for the guide element can be saved.

[0061] In a preferred embodiment, the side surface of the coating device in the first end position and the outer contour of the flow guide element in the first position are located in the same plane relative to the process chamber.

[0062] In this way, the coating device in the first end position partially assumes the position of the flow-guiding element, and the flow boundary surface for the process gas flow in the first position of the flow-guiding element therefore corresponds geometrically as far as possible to the flow boundary surface for the process gas flow when the coating device is in the first end position. Thus, the geometric boundary conditions for the process gas flow remain substantially unchanged for both configurations, and therefore no different influences on the process gas flow can be expected in the two cases.

[0063] In a preferred embodiment, a return weight is fastened to the flow guide element such that its weight acts as a return force for returning the flow guide element into the first position.

[0064] In this way, a particularly simple and cost-effective restoring mechanism can be provided, which quickly returns the air guide element to the first position, for example when the application device moves out of the first end position and loses contact with the air guide element in the process.

[0065] Furthermore, the return weight stabilizes the flow guide element when the process gas flow flows over it, so that vibrations of the flow guide element can be reduced and in particular completely suppressed.

[0066] In a preferred embodiment, the flow-guiding element is designed as part of a flow-guiding device of a machine tool, which, in addition to the flow-guiding element, comprises at least one further flow-guiding element for the process gas flow.

[0067] In this way, a flow guiding device comprising a plurality of flow guiding elements is provided in the machine tool, by means of which the interior of the process chamber can be optimally adapted to the process gas flow in a plurality of regions and / or sections.

[0068] The further flow-guiding elements are preferably designed in the manner of the "first" flow-guiding elements, in particular as flexible surface elements, which are preferably designed as membrane elements, woven elements or sheet metal elements. It is also suitable to use return weights here.

[0069] In a preferred embodiment, the further flow guiding element is arranged parallel to the flow guiding element in the first position, wherein this is not intended to be understood as a restriction to the alignment.

[0070] Other alignments are therefore also possible, but a parallel arrangement is particularly space-saving.

[0071] In a preferred embodiment, the further flow guide element extends in a first end position parallel to a side surface of the coating device and ends flush therewith, so that the side surface and the outer contour of the further flow guide element form a common control surface for the introduced process gas flow.

[0072] In this way, a continuous flush control surface for the process gas flow is provided in order to promote a swirl-free and turbulence-free process gas flow.

[0073] In a preferred embodiment, the flow guide device includes a supporting device, which is fastened to the processing chamber and has a driving unit, and the two flow guide elements are installed with the help of the driving unit and are arranged to move the flow guide elements relative to the processing chamber so that the passage from the first area to the second area of ​​the internal space of the processing chamber is opened or closed.

[0074] In this way, the flow guide element itself can be moved in order to thereby grant access to the processing area, for example in order to remove a produced workpiece or to clean the processing area.

[0075] The flow guide element is preferably raised or lowered relative to the treatment chamber. This is particularly suitable in the case of embodiments as flexible surface elements preferably have restoring weights, since it can be ensured that they do not become tangled or become tangled during the movement movement.

[0076] The raising and lowering directions here preferably extend vertically, ie parallel to the Earth's gravitational field.

[0077] In a preferred embodiment, the support device of the flow guide device includes a drivable shaft, and the flow guide element is fastened to the drivable shaft, wherein the flow guide element can be wound onto or unfolded from the shaft by rotation of the shaft, so that the passage from the first area to the second area of ​​the internal space of the processing chamber is opened in the wound state and closed in the unfolded state.

[0078] In this way, a particularly simple movement device for the air guide elements is provided, which allows a particularly space-saving support of the air guide elements since they are “wound up”.

[0079] The machine tool preferably comprises one or more further flow guiding devices according to one of the described embodiments, wherein the flow guiding devices preferably oppose each other across a building area of ​​the machine tool to thereby at least partially define a processing area within the processing chamber.

[0080] According to a second aspect of the present invention, there is provided a flow guiding device for use in a machine tool for additive manufacturing, in particular according to the first aspect of the present invention.

[0081] The flow guide device comprises at least one (first) flow guide element and one further flow guide element, wherein the at least one flow guide element and the further flow guide element can be fastened in a processing chamber of a machine tool for additive layered manufacturing of workpieces and can be used as guide elements for a process gas flow flowing through the processing chamber, wherein at least the (first) flow guide element is elastically deformable between a first position and a second position, wherein in the first position the flow guide element has a first external contour geometry, and in the second position the flow guide element has a second external contour geometry that is different from the first external contour geometry.

[0082] In this way, an already existing additive machine can be quickly and easily expanded or retrofitted by means of a device for guiding the process gas flow (i.e., a flow guide device) in order to optimally adapt the interior space to the process gas flow without requiring major structural measures. The above-mentioned advantages of using flow guide elements or flow guide devices apply analogously here.

[0083] Embodiments of the flow guide element (eg as a flexible surface element) have been described above, and therefore will not be described in detail here.

[0084] The flow guiding device preferably comprises a return weight which is fastened to one of the two guide elements, particularly preferably the flow guiding device comprises a return weight which is fastened to each guide element.

[0085] The two flow-guiding elements preferably extend mostly parallel to one another, in particular as parallel surfaces, wherein the distance between the two surfaces in the normal direction is smaller than the dimension of the flow-guiding elements in the longitudinal or width direction. In particular, the distance is at most 5%, preferably at most 1% and particularly preferably at most 0.1% of the length or width of one of the two flow-guiding elements.

[0086] The flow guide device preferably comprises a supporting device with a drive unit, by means of which the two flow guide elements are mounted and are arranged to move, in particular to raise and / or lower, the flow guide elements relative to the process chamber.

[0087] The support device of the flow guiding device preferably comprises a drivable shaft, to which the flow guiding element is fastened, wherein the flow guiding element can be wound onto or unwound from the shaft by rotation of the shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Further aspects of the above-mentioned aspects and features and advantages thereof as well as also more specific exemplary embodiments are described below with the aid of the figures shown in the drawings.

[0089] Figures 1A to 3 A first exemplary embodiment of a machine tool according to the invention is shown in different views and different positions of a coating device of the machine tool.

[0090] Figure 4 A second exemplary embodiment of a machine tool according to the invention is shown in a side view.

[0091] Figure 5A and 5B A detail of a third exemplary embodiment of a machine tool according to the invention is shown in a side view.

[0092] It is emphasized that the invention is in no way limited to the exemplary embodiments described below and their exemplary features. The invention further comprises modifications of the mentioned exemplary embodiments, in particular those which emerge from modifications and / or combinations of individual or multiple features of the described exemplary embodiments within the scope of protection of the independent claims. DETAILED DESCRIPTION

[0093] Figure 1A and Figure 1B A first exemplary embodiment of a machine tool 100 according to the invention is shown in a side view for two different positions of a coating device 60 of the machine tool 100 in the xy plane of a right-hand x, y, z coordinate system introduced for orientation.

[0094] The machine tool 100 is configured for additive layered manufacturing of workpieces, in which process a material 22 located on a carrier 21 is solidified by sequential irradiation at the height of a building region 20 of the machine tool 100 to form layers of the workpiece to be manufactured, for example by melting or sintering individual material particles, typically using an optical, typically laser-based irradiation device (not shown here).

[0095] For this purpose, the machine tool 100 comprises a process chamber 10 enclosing an interior space 30, a process gas device 40 (see in this respect Figure 3 ) and a guide device 50, the workpiece is manufactured (additive construction) in the inner space, and the building area 20 has a carrier 21 for material 22 which can be moved in the y direction.

[0096] The processing chamber 10 includes a base member 11, four side members 12a-12d ( Figure 1A and 1B The processing chamber 10 and the processing chamber 10 together with the processing chamber 10 and ...

[0097] In order to reliably remove impurities and pollutants (soot, exhaust gases and other manufacturing by-products) occurring during the manufacturing process in the closed interior space 30 from the closed interior space 30 and thus ensure constant manufacturing conditions in the interior space 30, a process gas device 40 is arranged to introduce a process gas flow 41 into the processing chamber 10 during the additive manufacturing process. The process gas flow 41 carries away the impurities and pollutants and extends, for example, as a parallel flow in the z direction.

[0098] In order to guide the process gas flow 41 through the process chamber 10 in a targeted and stable manner, at least one (first) flow-guiding element 51 is used, which is fastened in the process chamber 10 and is elastically deformable between a first position and a second position, in which the flow-guiding element 51 has a first outer contour geometry (see Figure 1A ), in the second position the air guide element 51 has a second outer contour geometry that is different from the first outer contour geometry (see Figure 1B The outer contour of the flow guide element 51 forms a flow boundary surface for the process gas flow 41, along which the process gas flow is guided from the inlet 42 of the process gas device to the outlet 43 of the process gas device (see Figure 3 ).

[0099] Stable is to be understood here as being as turbulent as possible, which could cause the material 22 to swirl and thus lead to a deterioration in the manufacturing quality. Therefore, a greater focus is on guiding the process gas flow 41 through the process chamber 10 parallel to the building area 20 as stably as possible.

[0100] Here, the flow guide element 51 divides the inner space 30 of the process chamber 10 into at least a first area 31 (processing area) and a second area 32, in which actual manufacturing is carried out, and the second area is separated from the first area as much as possible. The process gas flow 41 only flows through the first area 31, whereby the flow guide element 51 reliably isolates the interference sources (such as additional sensor systems or actuator systems) of the process gas flow 41 located in the second area 32. Therefore, the design of the second area 32, in particular the arrangement and shape selection of the components of the machine tool 100 there, becomes basically independent of the process gas flow 41.

[0101] The flow guide element 51 extends parallel to the side elements 12a of the process chamber 10 (in the y-direction) and perpendicular to the building area 20 or the base element 11 and is designed as a flexible surface element, in particular a membrane element.

[0102] The flow guide element 51 is designed as part of a flow guide device 50, which in turn comprises a further (second) flow guide element 53, reset weights 52, 54, a support device 55 for the flow guide elements 51, 53, and guide elements 56a, 56b for lateral support and for guiding the movement of the flow guide elements 51, 53. The support device 55 and the guide elements 56a, 56b will be described in detail below. Figure 2 Explain in more detail.

[0103] The resetting weights 52, 54 are fastened to the guide elements 51, 53 on the bottom side, wherein their weight acts as a force that causes the guide elements 51, 53, which are designed as flexible surface elements, to always try to reposition themselves. Figure 1A The vertical alignment reset force shown in .

[0104] The outer contour of the flow-guiding elements 51, 53 serves as a flow-bounding surface for the process gas flow 41, wherein the flow-guiding elements 51, 53 together define the flow boundary surface of the process gas flow 41. Figure 1A In the first position shown in FIG. 5 , a flow boundary surface extends parallel to the yz plane, which almost completely separates the first region 31 from the second region 32 . Here, the lower edge of the first flow guide element 51 ends almost flush with the base element 11 of the process chamber 10 .

[0105] As a result of the deformable design of the first flow-guiding element 51, the first flow-guiding element can be Figure 1A The first position shown in Figure 1BThe second position shown in FIG. 1 is reversibly or elastically deformable in a simple and almost resistance-free manner.

[0106] The elastic deformation is caused here by the movement of the coating device 60, which can be moved in translation (T) between a first end position 61 and a second end position 62 parallel to the building area 20. Here, the coating device 60 usually applies a material layer to the building area 20 via a coating lip or a brush, by which the material 22 is evenly spread out with a predetermined thickness. Here, the movement and application of the material layer must be carried out before each production step of the individual workpiece layer of the workpiece to be produced.

[0107] The coating device 60 is therefore used continuously and should therefore have to cover a movement path that is as short as possible for short production times. It is therefore advantageous not to remove the coating device 60 from the process chamber 10 each time and to introduce it again into the process chamber 10, but to leave it there, which in turn makes it a potential source of interruption to the process gas flow 41 flowing through the process chamber 10 during the production process.

[0108] In order to resolve this conflict, it is particularly suitable to use a deformable first flow guide element 51. Figure 1A and Figure 1B As can be seen from the overview, once the coating device has moved into its first end position 61, the deformable first flow guide element can be pressed away from the coating device. It is therefore not necessary to move the first flow guide element 51 directly adjacent to the building area 20, so that the coating device 60 can leave the area above the building space 20, thereby achieving a passive adaptation of the first flow guide element 51 to the movable part coating device 60.

[0109] If the first air guide element 51 is designed as a flexible surface element, deformation of the application device 60 requires only minimal forces and its movement is therefore not unnecessarily disturbed.

[0110] exist Figure 1B In the second position shown with the second outer contour geometry of the first air guide element 51 , the air guide element nests against the outer contour of the coating device 60 , wherein the part located above the coating device 60 is pulled away from its vertical starting position.

[0111] When the first end position 61 is reached, the right-hand surface of the coating device 60 replaces Figure 1A The outer contour of the first air guide element is shown in a first position.

[0112] In order to provide a flush, vertically extending flow boundary surface for the process gas flow 41 in this case, a second flow guide element 53 is used, which is provided at Figure 1BIt terminates above the coating device 60 almost flush with it and forms the vertical flow boundary surface together with its right-hand side surface.

[0113] On the side of the second end position 62 of the coating device, the flow boundary surface is realized by a rigid partition 70, Figure 4 In an alternative embodiment, the rigid partition may be replaced by another flow guiding device, and the rigid partition provides a third area 33 in the interior 30 of the processing chamber.

[0114] The machine tool according to the invention therefore offers the possibility of guiding the process gas flow, which in particular enables a minimum movement path, does not require additional actuator systems and makes partial regions of the interior particularly suitable for the process gas flow.

[0115] Thus, manufacturing time and maintenance work and the associated costs can be reduced. Furthermore, a modularly constructed flow guide can be provided which is as independent as possible from the overall shape of the process chamber 10 and can therefore be used for a plurality of machine tools.

[0116] Figure 2 The side view rotated 90 degrees in the yz plane shows the Figure 1A A machine tool 100 of a first exemplary embodiment is shown.

[0117] If available from Figure 2 As seen in FIG. 1 , the lower ends of the flow guide elements 51 , 53 are spaced apart in the vertical y direction to enable a retraction of the coating device 60 , which deforms only the first flow guide element 51 . The coating device 60 further ends flush with the base element 11 of the process chamber 10 .

[0118] The lateral end portions of these flow guide elements 51, 53 are guided in the vertical y-direction by guide elements 56a, 56b attached to the side elements 12c, 12d of the process chamber 10 (see also Figure 1A and 1B ) and is fastened to the upper side of the processing chamber 10 via the supporting device 55. Figure 2 In the position shown in FIG. 5 , the lateral guide elements 56 a, 56 b are separated so as not to hinder the deformation of the coating device 60 (see FIG. 5 ). Figure 1B ).

[0119] The support device 55 is designed here as a shaft 55a, which is rotatably connected to the process chamber 10 parallel to the z direction via a bearing 55b installed in the side elements 12c, 12d. The flow-guiding elements 51, 53 are fastened to the shaft 55a so that they can be rolled up on the shaft 55a and unrolled from the shaft, so that the lower ends of the flow-guiding elements 51, 53 can be raised and lowered in the vertical y direction, so as to open and close the passage from the first area 31 into the second area 32, for example, for removing the manufactured workpieces from the building area 20. For this purpose, Figure 2 The portions 51 ′, 53 ′ of a plurality of flow guide elements 51 , 53 which are partially wound around the shaft 55 a are shown.

[0120] The support device 55 comprises a drive unit 55c, which is preferably electric, and the shaft 55a can be rotated around a rotation axis R extending parallel to the z direction via the drive unit to wind and unwind the flow guide elements 51, 53. In the process, the lateral guide elements 56a, 56b are used to guide the flow guide elements 51, 53 in a targeted manner.

[0121] Figure 3 The plan view in the xz plane shows the Figure 1A The machine tool 100 of the first exemplary embodiment is shown in FIG. 1 in order to better illustrate the process gas flow 41 flowing through the processing chamber 10 .

[0122] For this purpose, the process gas device 40 comprises an inlet 42, which is arranged on one side of the side element 12d, via which a process gas flow 41 is introduced into the process chamber 10, more precisely into the first region 31 of the interior space 30. The introduction direction is parallel to the direction of the inlet 42 formed by the side element 12d. Figure 1A The plane formed by the air guide elements 51 , 53 in the position shown in FIG. 1 extends parallel to the yz plane.

[0123] Starting from the inlet 42 , a process gas flow 41 , which is represented schematically by selected arrows, flows through the first region 31 as far as an outlet 43 of the process gas device 40 .

[0124] exist Figure 3 The flow boundary surfaces of the parallel flow of the process gas flow 41 shown in the figure are here the left-hand flow guide elements 51, 53, the side surfaces of the coating device 60 and the partition 70 as well as the building area 20 and the base element 11 (see also in this respect Figure 1A ).

[0125] The elements are configured here such that they form a continuous and planar flow boundary surface along which the process gas flow flows in a turbulence-free and preferably flow-free manner in order to thus ensure stable and vortex-free flow conditions in the first region 31 (processing region).

[0126] This prevents swirling of material 22 located on building region 20 , which in turn allows a constant production quality of the individual workpiece layers, since local fluctuations in the thickness of the applied material layer are thereby prevented.

[0127] Figure 4 A second exemplary embodiment of a machine tool 100 according to the invention is shown in a side view in the xy plane.

[0128] Compared to the first exemplary embodiment, the machine tool 100 is different in that the separation element 70 (see FIG. Figure 1A ) has been replaced by a further flow guiding device 50 which has substantially the same construction as the first, left-hand flow guiding device 50.

[0129] In this way, two flow sides of the process gas stream 41 are formed using the proposed deformable flow-guiding elements, between which the coating device 60 can be moved back and forth without moving the flow-guiding elements, in order to exclude the coating device as a source of interference with the process gas stream. Particularly short movement paths of the coating device can thus be implemented without the risk of destabilizing the process gas stream.

[0130] Figure 5A and Figure 5B A detail of a third exemplary embodiment of a machine tool 100 according to the invention is shown in a side view in the xy plane for two different positions of a coating device 60 .

[0131] Compared to the first exemplary embodiment, the machine tool 100 is different in that the flap 72 rotatably mounted around the rotary joint 71 is arranged in a side view (see FIG. Figure 1A ) on the lower side of the separation element 70 on the right-hand side.

[0132] In this case, the upper portion of the machine tool 100 (at Figure 5A and 5B ) and Figure 1A The upper part of the first exemplary embodiment in FIG. 2 is identical and the left-hand side air guiding device also has the same design and therefore no further explanation is given at this point.

[0133] The flap 72 is fastened to the diaphragm via a swivel joint 71 so that the diaphragm is in a vertical starting position (see Figure 5B ) and horizontal position (see Figure 5A ) is rotatable, and in the vertical starting position the partition separates the first area 31 of the interior 30 from the third area 33.

[0134] Preferably, the rotary joint 71 includes a reset element, such as a spring element, via which the flap 72 reliably returns to its vertical starting position (in addition to the gravity acting on it) when the flap loses contact with the coating device 60, so as to thereby again form a planar flow interface for the process gas flow 41.

[0135] In the vertical starting position, the outer contours of the partition wall 70 and the flaps 72 preferably form a planar, in particular vertically extending, flow interface for the process gas flow 41 .

[0136] In the horizontal position, the coating device 60 has reached its second end position 62 and the flap 72 has been pressed out of the vertical starting position into the third region 33. In this case, the machine tool 100 is preferably designed such that the outer contour of the partition wall 70 and the outer contour of the coating device 60 form a planar (in particular vertically extending) flow interface for the process gas flow 41 in its second end position 62, as Figure 1A The same is true for the construction shown in .

[0137] The rotatable flap 72 thus enables a closable passage for the coating device 60 to the third region 33 of the interior 30, wherein a planar and substantially continuously extending flow interface is always present. Thus, compared to the first exemplary embodiment, at least for the case in which the coating device is located in the first end position 61 to its left, the guidance of the process gas flow 41 can be improved.

[0138] The exemplary embodiments of the present invention and their advantages have been described above in detail with reference to the accompanying drawings.

[0139] Finally, it is emphasized again that the present invention is in no way limited to the exemplary embodiments described above and their exemplary features. The present invention further comprises modifications of the mentioned exemplary embodiments, in particular those which emerge from modifications and / or combinations of individual or multiple features of the described exemplary embodiments within the scope of protection of the independent claims.

[0140] Reference numerals list

[0141] 10 Processing Chamber

[0142] 11 Base element

[0143] 12a-12d side elements

[0144] 13 Top element

[0145] 20 Build Area

[0146] 21 Removable carrier

[0147] 22 Materials

[0148] 30. The interior space of the processing chamber

[0149] 31 First Area (Processing Area)

[0150] 32 Second Area

[0151] 33 Third Area

[0152] 40 Process gas equipment

[0153] 41 Process gas flow

[0154] 42 Entrance

[0155] 43 Exit

[0156] 50 diversion device

[0157] 51, 51′ first flow guide element

[0158] 52 First reset weight

[0159] 53, 53' second flow guide element

[0160] 54 Second reset weight

[0161] 55 Support device

[0162] 55a Shaft

[0163] 55b Bearing

[0164] 55c Drive

[0165] 56a, 56b guiding element

[0166] 60 Coating device

[0167] 61 First end position

[0168] 62 Second end position

[0169] 70 Partition

[0170] 71 Rotary joint

[0171] 72 petals

[0172] 100 Machine Tools

Claims

1. A machine tool (100) for additive layered building of a workpiece, comprising: - a processing chamber (10) in which the additive construction of the workpiece is carried out; - a process gas device (40) arranged to introduce a process gas flow (41) into the processing chamber (10) during additive building; It is characterized in that A flow-guiding element (51) for the process gas flow (41), the flow-guiding element (51) being fastened in the processing chamber (10) and being elastically deformable between a first position and a second position, wherein the flow-guiding element (51) has a first outer contour geometry in the first position and a second outer contour geometry in the second position that is different from the first outer contour geometry.

2. The machine tool (100) according to claim 1, characterized in that: The flow guide element (51) is designed such that the first outer contour geometry corresponds to a planar surface.

3. The machine tool (100) according to claim 2, characterized in that: The flow guide element (51) is arranged in the first position in such a way that the planar surface extends parallel to the introduction direction of the introduced process gas flow (41).

4. The machine tool (100) according to at least one of claims 1 to 3, characterized in that The flow guide element (51) is designed as a flexible surface element.

5. The machine tool (100) according to claim 4, characterized in that: The flexible surface element is a membrane element or a woven element.

6. The machine tool (100) according to claim 4, characterized in that: The flexible surface element is a sheet metal element, in particular a spring steel strip.

7. The machine tool (100) according to any one of claims 1 to 6, characterized in that: The guide element (51) in the first position divides the inner space (30) of the process chamber (10) into at least a first area (31) and a second area (32), wherein the first area (31) is a process area in which the additive construction is performed, and wherein the process gas device (40) is configured to introduce the process gas flow (41) into the first area (31).

8. The machine tool (100) according to claim 7, characterized in that: The building area (20) of the machine tool (100) is completely arranged in the first area (31), and layered building is performed on the building area (20).

9. The machine tool (100) according to claim 7 or 8, characterized in that: The process chamber (10) comprises lateral shell elements (12a-12d), a top shell element (13) and a bottom shell element (11), wherein these shell elements and the flow-guiding element (51) are arranged relative to each other so that in the first position of the flow-guiding element (51), the introduced process gas flow (41) flows as a parallel flow along the flow-guiding element (51) through the first region (31) of the interior space (30) of the process chamber (10).

10. The machine tool (100) according to at least one of claims 1 to 9, characterized in that The machine tool (100) comprises a coating device (60), which is movable between a first end position and a second end position (61, 62) relative to the processing chamber (10), is configured to apply a layer of material for additive construction to a building area (20) of the machine tool (100) in the processing chamber (10), and is further configured to elastically deform the guide element (51) between the first position and the second position by movement.

11. The machine tool (100) according to claim 10, characterized in that: When the coating device (60) is in its first end position (61), the flow guide element (51) is brought into the second position, wherein the flow guide element (51) is at least partially supported against the coating device (60).

12. The machine tool (100) according to claim 11, characterized in that: The side surface of the coating device (60) forms a control surface for the introduced process gas flow (41) in the first end position (61).

13. The machine tool (100) according to claims 1 and 12, characterized in that The side surface of the coating device (60) in the first end position (61) and the outer contour of the flow guide element (51) in the first position are located in the same plane relative to the process chamber (10).

14. The machine tool (100) according to at least one of claims 1 to 13, characterized in that A return weight (52) is fastened to the flow guide element (51) so that the weight of the return weight acts as a return force for returning the flow guide element (51) to the first position.

15. The machine tool (100) according to at least one of the preceding claims, characterized in that The flow-guiding element (51) is designed as part of a flow-guiding device (50) of the machine tool (100), which, in addition to the flow-guiding element (51), also comprises at least one further flow-guiding element (53) for the process gas flow (41).

16. The machine tool (100) according to claim 15, characterized in that In the first position, the further flow-guiding element (53) is arranged parallel to the flow-guiding element (51).

17. The machine tool (100) according to any one of claims 15 or 16 and claim 12, characterized in that The further flow-guiding element (53) extends in the first end position (61) parallel to the side surface of the coating device (60) and ends flush therewith, so that the side surface and the outer contour of the further flow-guiding element (53) form a common control surface for the introduced process gas flow (41).

18. The machine tool (100) according to any one of claims 15 to 17 and claim 7, characterized in that The guide device (50) comprises a supporting device (55), which is fastened to the processing chamber (10) and has a driving unit (55c), and two guide elements (51, 53) are installed with the help of the driving unit and are configured to move the guide elements (51, 53) relative to the processing chamber (10) so that a passage from the first area (31) of the internal space (30) of the processing chamber (10) to the second area (32) is opened or closed.

19. The machine tool (100) according to claim 18, characterized in that The supporting device (55) of the flow guide device includes a drivable shaft (55a), and the flow guide element (51, 53) is fastened to the shaft, wherein the flow guide element (51, 53) can be wound onto the shaft (55a) or unfolded from the shaft (55a) by rotation of the shaft, so that the passage from the first area (31) of the internal space (30) of the processing chamber (10) to the second area (32) is opened in the wound state (51', 53') and closed in the unfolded state.

20. A support device (55) for use in a machine tool (100) according to at least one of claims 15 to 19.

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