DEVICE AND METHOD FOR MANUFACTURING THREE-DIMENSIONAL WORKPIECES

Description

[0001] The invention relates to a device and a method for producing three-dimensional workpieces. In particular, the invention relates to a device and a method for producing three-dimensional workpieces using an additive manufacturing process.

[0002] In additive manufacturing processes for producing three-dimensional workpieces, and particularly in additive layer manufacturing processes, it is known to apply a previously shapeless or shape-neutral molding compound (for example, a raw material powder) layer by layer onto a substrate and solidify it by site-specific irradiation (e.g., by fusing or sintering) to ultimately obtain a workpiece of the desired shape. Irradiation can be performed using electromagnetic radiation, for example, in the form of laser radiation. In its initial state, the molding compound can be in the form of granules, powder, or liquid and is selectively, or in other words, site-specifically, solidified as a result of the irradiation. The molding compound can, for example, comprise ceramic, metal, or plastic materials, and also mixtures thereof.One variant of additive manufacturing processes involves so-called powder bed fusion, in which metallic and / or ceramic raw material powders are solidified into three-dimensional workpieces.

[0003] To produce individual workpiece layers, it is also known to apply raw material powder material in the form of a layer onto a substrate and to irradiate it selectively according to the geometry of the workpiece layer currently being produced. The laser radiation penetrates the raw material powder material and solidifies it, for example, as a result of heating, which causes melting or sintering. Once a workpiece layer has solidified, a new layer of unprocessed raw material powder material is applied to the already produced workpiece layer. Known coating arrangements or powder application devices can be used for this purpose. Subsequently, the now uppermost and still unprocessed raw material powder layer is irradiated again. Consequently, the workpiece is built up successively layer by layer, with each layer defining a cross-sectional area and / or a contour of the workpiece.In this context, it is also known to use CAD or similar workpiece data to essentially manufacture the workpieces automatically.

[0004] An irradiation unit or system, which can be used, for example, in a device for producing three-dimensional workpieces by irradiating raw material powders, is described in EP 2 333 848 B1. The irradiation system comprises a beam source, in particular a laser source, and an optical unit. The optical unit, to which a processing beam emitted by the beam source is supplied, comprises a beam expansion unit and a deflection device in the form of a scanner unit. Within the scanner unit, diffractive optical elements are provided in front of a deflection mirror, wherein the diffractive optical elements are movable into the beam path in order to split the processing beam into a plurality of processing partial beams. The deflection mirror then serves to deflect the processing partial beams.

[0005] It is understood that all of the aspects explained above may also be provided for within the scope of the present invention.

[0006] Known devices for producing three-dimensional workpieces can be found, for example, in EP 2 961 549 A1 and in EP 2 878 402 A1.

[0007] The devices described in these documents each comprise a carrier that can be lowered vertically layer by layer. In these known devices, a corresponding vertical movement of the carrier always occurs after a layer of the raw material powder has been completely irradiated and before the next layer of powder is applied. This ensures that a focal plane of the irradiation unit is always located in the layer to be solidified (i.e., in the uppermost layer) of the raw material powder.

[0008] In the known devices described above, the vertical movement of the carrier requires an actuator or lifting mechanism. This lifting mechanism must, among other things, support and move both the workpiece being built and the surrounding powder material. Depending on the system size and the size of the corresponding build chamber, the lifting mechanism used can reach its load limits, which would necessitate a more complex and therefore more expensive lifting mechanism. Furthermore, the weight to be moved by the lifting mechanism changes during the build process. This can lead to a situation where the travel distance between two adjustment cycles of the lifting mechanism cannot be kept constant, resulting in undesirable variations in the layer thickness of the raw material powder layers.

[0009] EP 3 106 288 A1 discloses an additive manufacturing device comprising first and second spaced-apart side walls extending along a predefined path and defining a build chamber between them, one or more build units mounted for movement along the predefined path, wherein the one or more build units comprise at least one of the following: a powder dispenser positioned above the build chamber; an applicator configured to scrape powder dispensed into the build chamber; and a directed energy source configured to fuse the scraped powder.

[0010] US 2014 / 175708 A1 discloses a device for constructing a three-dimensional object, comprising a powder discharge unit that discharges powder onto an object build area, a powder flattening device that flattens the powder discharged by the powder discharge unit to form a powder layer, and a light emission unit located above the object build component that emits a beam of light onto the powder layer to sinter or solidify the powder to construct an object. The device for constructing a three-dimensional object further comprises a transfer mechanism that moves a light emission unit in three-dimensional directions and a shield that moves in conjunction with the light emission unit and surrounds a space above a region of the powder layer, smaller than the object build area, around the light beam.The powder discharge unit and the powder flattening device move in an integrated manner with the light emission unit.

[0011] The object of the invention is therefore to provide a solution for an additive layer build-up process which reduces or overcomes the above-mentioned problems and other related problems, wherein the solution provides a simple and precise way to control the layer thickness of a raw material powder layer, for example, even in large build spaces.

[0012] This problem is solved by a device having the features of claim 1 and a method having the features of claim 8.

[0013] According to a first aspect, the invention relates to a device for producing three-dimensional workpieces. The device comprises a carrier for receiving raw material powder and a build chamber wall extending substantially vertically, which is configured to laterally confine and support the raw material powder applied to the carrier. The device further comprises an irradiation unit for selectively irradiating the raw material powder applied to the carrier with electromagnetic radiation or particle radiation in order to produce a workpiece made from the raw material powder on the carrier by means of an additive manufacturing process, wherein the irradiation unit comprises at least one optical element.Furthermore, the device comprises a vertical movement device which is configured to move the irradiation unit vertically with respect to the support, wherein the construction chamber wall and the support are configured to be fixedly connected to each other during the vertical movement of the irradiation unit, so that the vertical movement is relative to the support and relative to the construction chamber wall.

[0014] The carrier can provide a horizontal surface onto which the raw material powder can be applied layer by layer, i.e., in horizontal layers. The build chamber wall can serve as the lateral boundary of the build chamber. The build chamber can, for example, have a round, elliptical, polygonal, or rectangular cross-section, particularly a square one, as defined by the build chamber wall. The raw material powder can be contained and supported by the build chamber wall in such a way that it is held in shape and does not trickle down the sides.

[0015] In this disclosure, the term "construction chamber" is to be understood as a spatial area in which the application of the raw material powder layers takes place and which is bounded below by the support and laterally by the construction chamber wall. The construction chamber can be an airtight, sealed volume, which is sealed airtight at the top by a suitable ceiling and, if necessary, by appropriate sealing materials. The ceiling can be vertically movable together with the irradiation unit. However, the construction chamber can also be open at the top and thus not define a clearly defined volume. For example, the construction chamber can have the shape of a cuboid open at the top. The construction chamber can be located within an outer housing and / or within an outer wall of the device.Furthermore, in addition to the build chamber, there may be further build chambers within the outer housing as part of the device.

[0016] The construction chambers described herein can have a side length of, for example, more than 50 cm. In other words, at least one of the two orthogonal sides of the beam can be at least 50 cm. Furthermore, at least one of the two orthogonal sides of the beam can be at least 100 cm. Thus, the beams used herein can, for example, have a base area of ​​1 m x 1 m.

[0017] The optical element of the irradiation unit can be, for example, a scanning unit, a focusing unit and / or an F-theta lens.

[0018] Furthermore, the irradiation unit can include a beam source, such as an electron beam source or a laser. However, the radiation emitted by the irradiation unit can also be supplied to the unit from a beam source located outside the unit. For this purpose, mirrors, optical fibers, and / or other light guides can be used, for example.

[0019] The support can be permanently connected to a foundation of the device. The foundation of the device can, for example, comprise a base plate. The foundation can be designed to remain immovable after the device has been erected and / or during its operation (i.e., during a construction process). In particular, the foundation can be immovable with respect to a vertical direction. Here, the term "immovable" means fixed in place with respect to the environment in which the device is erected.

[0020] The vertical movement device can, for example, include a lifting device. The vertical movement device can include one or more hydraulic and / or mechanical actuators. During vertical movement, the irradiation unit can move up and down independently of the chamber wall. In particular, the chamber wall can be designed so that it is not mechanically coupled to the irradiation unit and, in particular, does not move up and down together with it.

[0021] This fixed position of the build chamber wall ensures that the raw material powder inside is not mechanically affected during vertical movement and, in particular, that no unwanted disturbance of the raw material powder occurs in the edge regions of the build chamber. This ensures that the surface of the raw material powder has the same (largely horizontal and flat) structure before and after the vertical movement of the irradiation unit. Furthermore, mechanical friction losses and thus energy losses at the interface between the build chamber wall and the raw material powder can be avoided if the build chamber wall is not moved relative to the raw material powder during a build process.

[0022] The wall of the construction chamber can be designed to completely surround the raw material powder applied to the carrier laterally and to confine and support the raw material powder on all sides.

[0023] In this context, "on all sides" means that the build chamber wall forms a barrier to the raw material powder in all horizontal directions. However, at least one closable opening may be provided in the build chamber wall through which, for example, raw material powder and / or the finished workpiece can be removed.

[0024] The construction chamber wall can be rigidly connected to the support and / or foundation of the device. Alternatively, the construction chamber wall can be detachably connected to the support and / or foundation and designed to be detached from the support after the construction process is complete, in order to remove the finished workpiece.

[0025] If the construction chamber wall is detachably connected to the support, it can, for example, be lifted upwards to release the finished workpiece after the construction process is complete and make it accessible from the side. A suitable lifting device for raising the construction chamber wall can be provided for this purpose.

[0026] The device further comprises a powder application device which is designed to apply the raw material powder layer by layer to the carrier.

[0027] The powder application device may include a powder container and / or be connected to a powder reservoir so that raw material powder can be supplied to the powder application device. The powder application device is designed to move horizontally over a previous layer of powder and apply a new layer of powder. For this purpose, the powder application device may include at least one roller, a slide, and / or similar suitable means for applying a layer of raw material powder.

[0028] The vertical movement device can be configured to move the irradiation unit vertically together with the powder application device.

[0029] The powder application device can, for example, be attached to a holding device that moves up and down together with the irradiation unit. This allows the vertical distance between the irradiation unit and the powder application device to be kept constant. This ensures that a newly applied layer of raw material powder is always located within a focal plane of the irradiation unit.

[0030] The device may include a further vertical motion device that is mechanically independent of the vertical motion device and is configured to move the powder application device vertically.

[0031] The additional vertical movement device can, for example, be attached to the wall of the build chamber. This additional vertical movement device can include guide elements (e.g., rails) which are provided on the inside of the build chamber wall, and along which the powder application device can be moved up and down.

[0032] The device may further include a control unit which is configured to control the vertical movement device in such a way that the irradiation unit can be adjusted in height vertically relative to the support and relative to the construction chamber wall according to a desired thickness of a respective raw material powder layer to be applied.

[0033] The control unit can be a central control unit of the device, which monitors and / or controls a number of process sequences of the device. The control unit can include a processor (for example, a CPU) and memory. A program containing instructions that cause the device to carry out the process sequence described herein can be stored in the memory. The adjustment path of the vertical movement device, which is traversed during a movement process between the solidification of two layers, can correspond to the thickness of a raw material powder layer.

[0034] The device further comprises at least one gas inlet, which is configured to direct a gas into a construction chamber defined by the construction chamber wall, and at least one gas outlet, which is configured to draw in the gas introduced by the gas inlet. The gas inlet and the gas outlet may, in particular, be configured to generate a gas flow running substantially parallel to the support.

[0035] The gas can be an inert gas such as argon or nitrogen. The gas inlet can include an opening designed to allow the gas to flow substantially horizontally along a surface of the raw material powder layer. Furthermore, a gas outlet can be provided for drawing in the gas flowing from the gas inlet. The gas outlet can, for example, be located at substantially the same level as the gas inlet. Moreover, the gas outlet is positioned relative to the gas inlet in the direction of a gas flow generated by the gas inlet. Thus, a substantially horizontal laminar gas flow can be generated along a surface of the raw material powder layer.

[0036] The vertical movement device is designed to move the irradiation unit vertically together with the gas inlet.

[0037] This ensures that the gas inlet is always at a constant height above the uppermost layer of raw material powder. The gas inlet can be rigidly mechanically coupled to the irradiation unit. If a gas outlet is also provided, the vertical movement mechanism can further be configured to move the irradiation unit vertically along with the gas inlet and outlet.

[0038] The device comprises several irradiation units arranged side by side, each comprising at least one optical element and each configured to scan an electromagnetic beam or a particle beam over the raw material powder, wherein the vertical movement device is configured to move the several irradiation units together vertically with respect to the carrier.

[0039] The irradiation units can be mounted on a common frame. Furthermore, an irradiation area can be defined for each irradiation unit within the installation space. The irradiation areas can be defined on a common support or on several supports designated for the respective irradiation areas. The irradiation units can be configured to independently scan an electromagnetic beam or a particle beam across their respective irradiation areas. Each irradiation unit can also include a beam source (e.g., a laser), or a common beam source can be used, the beam of which is split into partial beams for the respective irradiation units by at least one beam splitter.

[0040] The device may further include a horizontal movement device which is configured to move the irradiation unit horizontally with respect to the carrier and with respect to the raw material powder applied to the carrier.

[0041] The horizontal movement device can be configured to move horizontally in such a way that areas of the assembly chamber which were inaccessible to the irradiation unit before the horizontal movement become accessible and irradiated by the irradiation unit after the horizontal movement. In other words, the horizontal movement device can be configured to move horizontally over the same support structure of the same assembly chamber. Furthermore, the horizontal movement device can be configured to move the irradiation unit from a first assembly chamber to a second assembly chamber, as described below.

[0042] The device can comprise several adjacent construction chambers, each of which has a construction chamber wall and a support laterally surrounding the respective construction chamber, wherein the horizontal movement device is configured to move the irradiation unit from a first construction chamber of the several construction chambers to a second construction chamber of the several construction chambers.

[0043] The horizontal movement device can also be designed to move the construction chamber horizontally relative to the irradiation unit, while the irradiation unit remains stationary with respect to a horizontal direction. Thus, for example, a conveyor belt for construction chambers can be provided, by means of which several construction chambers can be fed to the irradiation unit by means of a horizontal movement.

[0044] The horizontal movement can be executed such that the irradiation unit is initially located essentially centrally above the support of the first construction chamber and, after the horizontal movement, is located essentially centrally above the support of the second construction chamber. The horizontal movement device can have rollers or wheels by means of which it can be moved over a common foundation, with the rollers or wheels running over the common foundation. Additionally or alternatively, rails or other suitable guide elements can be provided on a common foundation to guide the horizontal movement from the first construction chamber to the second construction chamber. The support of the first construction chamber and the support of the second construction chamber can be arranged on the common foundation. Furthermore, the support of the first construction chamber and / or the support of the second construction chamber can form part of a surface of the common foundation.

[0045] This applies in principle to all the beams described herein: The beam can represent part of the surface of a larger element, such as a foundation. Apart from the wall of the construction chamber, the beam does not need to be structurally distinct from the surface surrounding it. For example, the beam can simply be defined as a surface of a foundation, with the wall of the construction chamber laterally limiting this surface. The wall of the construction chamber can, for example, be raised.

[0046] The horizontal movement mechanism can also be designed such that the irradiation unit is suspended from a common ceiling of the device and guided along this common ceiling from the first assembly chamber to the second assembly chamber. Rails or other linear or non-linear guide elements can be provided for this purpose.

[0047] The device may further include a control unit which is configured to control the horizontal movement device in such a way that the irradiation unit is moved horizontally to the second construction chamber after completion of a first construction process in the first construction chamber and subsequently controls the irradiation unit in such a way that it begins a new construction process in the second construction chamber.

[0048] This allows the finished workpiece to cool down and / or be unpacked (freed from excess raw material powder) in the first build chamber while a build process takes place in the second build chamber. The control unit can be the same unit that also controls the vertical motion mechanism. Alternatively, separate control units can be used. Furthermore, the control unit can be a central control unit for the entire device.A common control unit for the vertical and horizontal movement devices can, for example, be configured to, after completion of the first construction process, if necessary, raise the irradiation unit completely vertically out of the construction chamber, then move it horizontally over the walls of the first and second construction chambers and lower the irradiation unit in the second construction chamber so that a first layer of raw material powder can be applied and selectively irradiated in the second construction chamber.

[0049] According to a second aspect, the invention relates to a method for producing three-dimensional workpieces. The method comprises applying raw material powder to a carrier, wherein the raw material powder applied to the carrier is laterally bounded and supported by a build chamber wall extending substantially vertically, and selectively irradiating the raw material powder applied to the carrier with electromagnetic radiation or particle radiation by an irradiation unit in order to produce a workpiece made from the raw material powder on the carrier by an additive layer manufacturing process, wherein the irradiation unit comprises at least one optical element.Furthermore, the method includes vertical movement of the irradiation unit relative to the support by means of a vertical movement device, while the construction chamber wall and the support are fixedly connected to each other, so that the vertical movement is relative to the support and relative to the construction chamber wall.

[0050] The method can, for example, be carried out by one of the devices described herein. Furthermore, the method can include all process steps for which the devices described herein are suitable or configured.

[0051] The procedure may further include horizontal movement of the irradiation unit from a first construction chamber to a second construction chamber by means of a horizontal movement device, after completion of a construction process in the first construction chamber, and commencement of a construction process in the second construction chamber.

[0052] The invention is explained below with reference to the accompanying figures. These figures represent: Figure 1: a schematic side view of an embodiment of a device performing a method; Figure 2: a schematic side view of an embodiment of a device according to the invention performing a method according to the invention; and Figure 3: a schematic top view of another embodiment of a device performing a method.

[0053] In Figure 1 An embodiment of a device 1 is shown in a schematic side view. The views in the figures are not necessarily to scale. A vertical direction (hereinafter also referred to as the z-direction) is defined in the figure by the arrow 3, and a horizontal plane (hereinafter also referred to as the xy-plane) extends perpendicular to the drawing plane along the base 5.

[0054] The foundation 5 forms a base plate for the device 1. The device 1 may also have an outer housing (not shown) with outer walls and an outer roof. However, the device 1 may also be designed without its own outer housing in an open construction, for example in a factory building.

[0055] A beam 7, which has a horizontal rectangular surface, is provided on the foundation 5. The beam 7 is fixedly connected to the foundation 5 and is designed to receive several layers of raw material powder 9. A construction chamber wall 11 adjoins the beam 7 laterally, completely surrounding it laterally. Both the beam 7 and the construction chamber wall 11 thus have a rectangular cross-section in plan view. The construction chamber wall 11 surrounds the beam 7 laterally in such a way that it abuts the raw material powder 9 located on the beam 7, supports it laterally, and holds it in a cuboid shape.

[0056] The build chamber wall 11 defines a build chamber 13 located within the build chamber wall 11. A build process for a workpiece 15 takes place in the build chamber 13 using an additive manufacturing process. The build chamber 13 is bounded laterally by the build chamber wall 11 and downwards by the support 7. A physical upper boundary of the build chamber 13 is not necessary; in particular, the build chamber 13 does not need to be airtight at the top. In the illustration of the Figure 1 The construction chamber 13 is bounded at the top by an irradiation unit 17 and by part of an irradiation unit carrier 19.

[0057] The build chamber 13 can, however, be sealed airtight, for example by providing sealing materials (not shown) between the build chamber wall 11 and the irradiation unit carrier 19. This has the advantage that a protective gas (for example, an inert gas such as argon or nitrogen) cannot escape from the build chamber 13 and that no contaminants can penetrate the build chamber 13. However, an airtight seal is not absolutely necessary when using argon as a protective gas, for example, because argon, due to its high density, accumulates in the area of ​​the build chamber floor (i.e., in the area of ​​the raw material powder 9) and cannot escape upwards.

[0058] The device 1 further comprises a powder application device 21, by means of which the raw material powder 9 can be applied layer by layer to the carrier 7. For this purpose, the powder application device 21 can include at least one roller, at least one slide, and / or other suitable powder application means, which are capable of applying a layer of raw material powder of as uniform a thickness as possible to the carrier 7 or to a previous layer of raw material powder. The powder application device 21 is connected to a raw material powder reservoir (not shown) in order to be supplied with raw material powder 9 from it.

[0059] The device 1 further comprises an irradiation unit 17 for selectively irradiating the raw material powder 9 applied layer by layer to the carrier 7. Using the irradiation unit 17, the raw material powder 9 can be exposed to site-selective radiation, depending on the desired geometry of the workpiece 15 to be produced. For this purpose, the irradiation unit 17 comprises a beam source, which can be in the form of a laser. This laser can, for example, emit light at a wavelength of approximately 1064 nm. Alternatively, the beam source (for example, a laser) can also be located outside the irradiation unit 17, and a beam directed at the raw material powder 9 is supplied to the irradiation unit 17, for example, by means of an optical fiber.

[0060] The irradiation unit 17 further comprises optical elements, such as a scan unit, a focus unit, and an F-theta lens. The scan unit is configured to scan the beam across the uppermost layer of raw material powder within a horizontal plane (in the x and y directions). The focus unit is configured to change or adjust the focus position of the beam (in the z direction) so that a focal plane of the irradiation unit 17 is located in the area of ​​the uppermost layer of raw material powder being irradiated by the irradiation unit 17. The irradiation unit 17 can, for example, be an irradiation unit or irradiation device as described in EP 2 333 848 B1.

[0061] Furthermore, the device 1 has a gas inlet 23 and a gas outlet 25. The gas inlet 23 has an opening for the outflow of a gas (for example, an inert gas such as argon or nitrogen). The gas outlet 25 also has an opening for drawing in the gas flowing out of the gas inlet 23. The opening of the gas inlet 23 and the opening of the gas outlet 25 are arranged essentially at the same level and at a short distance from a surface of the raw material powder 9. In this way, a laminar and essentially horizontal gas flow can be provided parallel to the support 7 across the surface of the raw material powder 9. This gas flow can be suitable for the controlled extraction of process-related impurities (for example, splashes and melt flux). The gas inlet 23 and the gas outlet 25 can be configured, for example, as described in European patent application 15 186 889.0.

[0062] Both gas inlet 23 and gas outlet 25 are optional elements of the device 1, and these elements may be omitted or provided elsewhere than described herein.

[0063] The irradiation unit 17, the gas inlet 23, and the gas outlet 25 are attached to the irradiation unit carrier 19 such that a vertical movement of the irradiation unit carrier 19 results in a vertical movement of the irradiation unit 17, the gas inlet 23, and the gas outlet 25. Furthermore, the powder application device 21 is attached to the irradiation unit carrier 19 such that a vertical movement of the irradiation unit carrier 19 results in a vertical movement of the powder application device 21. Alternatively, however, the powder application device 21 can also be arranged independently of the irradiation unit carrier 19. For example, the powder application device 21 can be arranged on the build chamber wall 11 and be provided with a corresponding vertical movement mechanism to move up and down along the build chamber wall 11.Furthermore, a horizontal movement device is provided for the powder application device 21, by means of which the powder application device 21 can be moved horizontally over the carrier 7, as indicated by arrow 27. Alternatively or in addition to the movement in the direction of arrow 27 (x-direction), the horizontal movement device of the powder application device 21 can also be configured to move the powder application device 21 in the y-direction over the carrier 7.

[0064] The irradiation unit carrier 19 is attached to a frame 29 in a vertically movable manner. The irradiation unit carrier 19, and thus the irradiation unit 17, can be moved up and down relative to the frame 29 by means of a vertical movement device 31. The vertical movement device 31 of the Figure 1The illustrated device 1 comprises a motor, which can be, for example, a stepper motor or a servo motor. The vertical motion device 31 can be configured in various ways and can, for example, include any type of actuator or lifting device. For example, the vertical motion device 31 can have a hydraulic and / or mechanical actuator. The vertical motion device 31 can, for example, have a spindle shaft and a motor driving the spindle shaft.

[0065] The vertical movement device 31 allows the vertical distance between the irradiation unit 17 and the carrier 7 to be changed. In particular, this distance can be changed so that the distance between the irradiation unit 17 and the uppermost layer of the raw material powder 9 always remains constant. The vertical movement of the vertical movement device 31 takes place independently of and relative to the build chamber wall 11; that is, in particular, the build chamber wall 11 is not moved by the vertical movement device 31.

[0066] Furthermore, the device 1 comprises a control unit 33, which is configured to control the vertical motion device 31 and a horizontal motion device 35 described below. The control unit 33 comprises a CPU and a memory, wherein a program is stored in the memory which, when executed by the CPU, causes the device 1 to perform one of the procedures described herein. Furthermore, the control unit 33 can perform all control tasks of the device 1 and, for example, control the irradiation unit 17, the powder application device 21, the gas flow through the gas inlet 23, and the gas outlet 25.

[0067] The assembly process of the device 1 takes place and is controlled by the control unit 33 such that the vertical motion device 31 lowers the powder application device 21 to a height sufficient for the powder application device 21 to apply a first layer of raw material powder to the carrier 7. Subsequently, or simultaneously, the vertical motion device 31 moves the irradiation unit 17, if necessary, to a height suitable for selectively irradiating this first layer of raw material powder and solidifying it (for example, by fusing or sintering). During this process, the scan unit scans the beam across the raw material powder 9 according to a predetermined pattern. After the first layer of raw material powder has been irradiated as desired, the vertical motion device 31 raises the powder application device 21 to a height at which it can apply a second layer of raw material powder to the first layer.The second layer of raw material powder is then irradiated, analogous to the irradiation of the first layer of raw material powder.

[0068] During the assembly of the desired workpiece 15, the vertical motion device 31 moves the irradiation unit 17 (and, if applicable, the other components attached to the irradiation unit carrier 19, namely gas inlet 23, gas outlet 25 and / or powder application device 21) further and further away from the carrier 7. Subsequently, the irradiation unit 17 can be completely lifted upwards out of the build chamber 13 and moved to another build chamber by means of a horizontal motion device 35, as described below with reference to Figure 3 described.

[0069] After the construction process in the build chamber 13 is complete, the finished workpiece 15 can cool down. Subsequently, a lifting device (not shown) can raise the build chamber wall 11 so that the excess raw material powder 9 can trickle out laterally from the build chamber 13, and the finished workpiece 15 is accessible from the side. The workpiece 15 can now be completely cleaned of the excess raw material powder 9. Furthermore, a closable opening can be provided in the build chamber wall 11, which can be opened after the construction process and through which the finished workpiece 15 and / or excess raw material powder 9 can be removed.

[0070] The frame 29 of the device 1 further comprises a horizontal movement device 35. In the exemplary embodiment of the Figure 1The horizontal movement device comprises 35 rollers by means of which the frame 29, together with the attached irradiation unit carrier 19 and the components attached to the irradiation unit carrier 19 (irradiation unit 17, gas inlet 23, gas outlet 25 and / or powder application device 21), can be moved horizontally. The rollers are driven by one or more motors, which are controlled by the control unit 33. The frame 29 is rolled over the foundation 5 by means of the rollers. Additionally, appropriate (linear or non-linear) guide elements, such as rails, can be provided to guide the horizontal movement of the frame 29 over the foundation 5. Alternatively to the design of the Figure 1, in which the frame 29 is rolled over the foundation 5 via rollers, the frame 29 can be horizontally movably attached to a ceiling of an outer housing of the device 1, which can be ensured, for example, by appropriate rails.

[0071] The horizontal motion device 35 can be designed in such a way that it not only enables linear movement in a horizontal direction, but also controlled movements within the horizontal plane (both in the x-direction and in the y-direction).

[0072] The horizontal movement device 35 can serve, on the one hand, to make areas of the raw material powder layers accessible to the irradiation unit 17 during the build process of the workpiece 15, areas which were inaccessible to the irradiation unit 17 before the horizontal movement. This allows the effective build area to be increased and larger workpieces 15 to be produced. On the other hand, the horizontal movement device 35 can serve to move the irradiation unit 17 from a first build chamber to a second build chamber, as will be shown later with reference to Figure 3 described.

[0073] In Figure 2 An embodiment of a device 1 according to the invention is shown in a schematic side view. Elements with the same reference numeral correspond to those of the device 1 of the Figure 1The functionality of these elements is identical to the functionality of the corresponding elements of device 1. Figure 1 .

[0074] In contrast to device 1 of the Figure 1 The device 1 of the Figure 2 not just one, but several irradiation units 17 arranged side by side. In the example of the Figure 2Three irradiation units 17 are provided, although fewer or more irradiation units 17 may also be provided. Each of the irradiation units 17 defines an irradiation area on a common carrier 7. One workpiece 15 can be produced in each of the irradiation areas. However, it is also possible for the irradiation areas of the irradiation units 17 to be directly adjacent to or overlapping, so that one large workpiece can be produced, with each of the irradiation units 17 being responsible for solidifying a predetermined area of ​​the workpiece. The three irradiation areas are located in a common build chamber 13, which is surrounded by a build chamber wall 11.

[0075] Each of the irradiation units 17 has a gas inlet 23 and a gas outlet 25 for generating a horizontal gas flow over the respective irradiation area. Alternatively, however, only a common gas inlet and a common gas outlet 25 may be provided, so that, for example, only the outer areas of the irradiation unit carrier 19 have a gas inlet 23 and a gas outlet 25. Furthermore, the device 1 has a common powder application device 21, which can apply powder layers over the entire surface of the carrier 7. Alternatively, a separate powder application device may be provided for each of the irradiation areas.

[0076] By means of the device 1 of the Figure 2Having several irradiation units 17, larger (common) workpieces can be produced on the one hand, and several workpieces 15 can be produced simultaneously, resulting in a reduced process time per workpiece 15.

[0077] Figure 3 Figure 1 shows a further embodiment of a device 1 for producing a three-dimensional workpiece, wherein the device 1 of the third embodiment is, for example, the device 1 of the Figure 1 or the device 1 of the Figure 2 The device 1 of the Figure 3 It comprises a first construction chamber 13a and a second construction chamber 13b. Further construction chambers may also be provided (not shown).

[0078] In Figure 3The first construction chamber 13a and the second construction chamber 13b are shown in plan view. Construction chamber 13a is surrounded by a construction chamber wall 11a, and construction chamber 13b is surrounded by a construction chamber wall 11b. Construction chamber 13a or 13b could, for example, be one of the in Figure 1 or Figure 2 The illustrated construction chambers 13 are located in the building chambers 13a and 13b. These chambers are arranged on a common foundation 5.

[0079] Furthermore, the following is located in the Figure 3 The depicted state of the frames 29 above the first build chamber 13a allows a workpiece 15 to be manufactured within the first build chamber 13a using an additive manufacturing process. The necessary elements of the device 1 correspond, for example, to those of the Figure 1 or the Figure 2 .

[0080] After completion of the construction process in the first construction chamber 13a, the frame 29 moves across the foundation 5 from the first construction chamber 13a to the second construction chamber 13b using the horizontal movement device 35, as indicated by arrow 37. Above the second construction chamber 13b, the irradiation unit 17 or units 17 are then lowered above the support 7 using the vertical movement device 31, and a new (second) construction process begins in the second construction chamber 13b.

[0081] During the second construction process, the workpiece 15 can cool down in the first construction chamber 13a and can be removed, for example, by lifting the construction chamber wall 11a or through an opening in the construction chamber wall 11a.

[0082] This enables the production of multiple workpieces 15 in multiple build chambers 13a, 13b using a reduced number of irradiation units 17, compared to a situation where each of the build chambers 13a, 13b has its own irradiation unit 17 or irradiation units 17. In addition to the two in the Figure 3 In addition to the illustrated construction chambers 13a and 13b, further construction chambers with corresponding construction chamber walls may be provided, so that the frame 29 together with its irradiation unit(s) 17 (and possibly the further components attached to the irradiation unit carrier 19, namely gas inlet / gas inlets 23, gas outlet / gas outlets 25 and / or powder application device(s) 21) can traverse these construction chambers one after the other and carry out a construction process in each of the respective construction chambers.

[0083] The construction chambers 13, 13a, 13b described herein can be large construction chambers with a side length of, for example, more than 50 cm each. In other words, at least one of the two orthogonal side lengths of the beam 7 can be at least 50 cm. Furthermore, at least one of the two orthogonal side lengths of the beam 7 can be at least 100 cm. Thus, the beams 7 used herein can be beams with a base area of ​​1 m x 1 m.

[0084] Because the device described herein has a vertically movable irradiation unit, the irradiation unit moves relative to the support without the need to move the support itself. When using sufficiently large supports, this has the advantage that no heavy powder or workpiece needs to be moved during the build process.

[0085] Furthermore, the irradiation unit is moved relative to the build chamber wall, ensuring that the build chamber wall remains stationary relative to the raw material powder. This prevents friction at any interface between the build chamber wall and the raw material powder, thus preventing any disruption of the powder layers. Because the build chamber wall remains stationary relative to the raw material powder, sealing the build chamber wall to the support structure is relatively straightforward, i.e., ensuring that no powder can penetrate through a gap between the build chamber wall and the support structure. With conventional devices, this sealing presents a greater challenge, as the support structure must be able to move vertically relative to the build chamber wall.

[0086] Furthermore, the mobility of the irradiation unit independent of the construction chamber wall enables the irradiation unit to be moved from a first construction chamber to a second construction chamber and from there, if necessary, to further construction chambers.

Claims

1. A device (1) for producing three-dimensional workpieces (15), comprising: - a carrier (7) for receiving raw material powder (9), - a build chamber wall (11, 11a, 11b) which extends substantially vertically and which is adapted to laterally delimit and support the raw material powder (9) applied to the carrier (7), - an irradiation unit (17) for selectively irradiating the raw material powder (9) applied to the carrier (7) with electromagnetic radiation or particle radiation in order to produce on the carrier (7) a workpiece (15) manufactured from the raw material powder (9) by an additive layer building method, wherein the irradiation unit (17) comprises at least one optical element, and - a vertical movement device (31) which is adapted to move the irradiation unit (17) vertically with respect to the carrier (7), wherein the build chamber wall (11, 11a, 11b) and the carrier (7) are adapted to be connected to one another in a stationary manner during the vertical movement of the irradiation unit (17) so that the vertical movement takes place relative to the carrier (7) and relative to the build chamber wall (11, 11a, 11b), - a powder application device (21) which is adapted to apply the raw material powder (9) layer by layer to the carrier (7), - a horizontal movement device which is adapted to move the powder application device (21) over the carrier (7) in a horizontal direction, wherein the build chamber wall (11, 11a, 11b) is rigidly connected to the carrier (7) and / or to a base (5) of the device (1), or wherein the build chamber wall (11, 11a, 11b) is detachably connected to the carrier (7) and / or to the base (5) and is adapted to be detached from the carrier (7) on completion of a build process, in order to remove the finished workpiece (15), wherein the device (1) comprises at least one gas inlet (23) which is adapted to direct a gas into a build chamber (13, 13a, 13b) defined by the build chamber wall (11, 11a, 11b), and at least one gas outlet (25) which is adapted to draw in the gas introduced from the gas inlet (23), wherein the gas inlet (23) and the gas outlet (25) are adapted to generate a gas stream flowing substantially parallel to the carrier (7), wherein the gas outlet (25) is arranged opposite of the gas inlet (23) in a direction of gas stream generated by the gas inlet (23), wherein the vertical movement device (31) is adapted to move the irradiation unit (17) vertically together with the gas inlet (23) and the gas outlet (25), and wherein the device (1) comprises a plurality of irradiation units (17) arranged side by side, each of which comprises at least one optical element and each of which is adapted to scan an electromagnetic beam or a particle beam over the raw material powder (9), and wherein the vertical movement device (31) is adapted to move the plurality of irradiation units (17) together vertically with respect to the carrier (7).

2. The device (1) as claimed in claim 1, further comprising: - a further vertical movement device which is mechanically independent of the vertical movement device (31) and which is adapted to move the powder application device (21) vertically.

3. The device (1) as claimed in claim 1 or 2, wherein the build chamber wall (11, 11a, 11b) is adapted to laterally surround the raw material powder (9) applied to the carrier (7) completely and to delimit and support the raw material powder (9) on all sides.

4. The device (1) as claimed in any one of claims 1 to 3, further comprising a control unit (33) which is adapted to control the vertical movement device (31) in such a manner that the irradiation unit (17) is vertically adjustable in terms of its height relative to the carrier (7) and relative to the build chamber wall (11, 11a, 11b) according to a desired thickness of a respective raw material powder layer that is to be applied.

5. The device (1) as claimed in any one of claims 1 to 4, further comprising a horizontal movement device (35) which is adapted to move the irradiation unit (17) horizontally with respect to the carrier (7) and with respect to the raw material powder (9) applied to the carrier (7).

6. The device (1) as claimed in claim 5, wherein the device (1) comprises a plurality of build chambers (13a, 13b) arranged side by side, each of which has a build chamber wall (11a, 11b) which laterally surrounds the respective build chamber (13a, 13b), and a carrier (7), and wherein the horizontal movement device (35) is adapted to move the irradiation unit (17) from a first build chamber (13a) of the plurality of build chambers to a second build chamber (13b) of the plurality of build chambers.

7. The device (1) as claimed in claim 6, further comprising a control unit (33) which is adapted to control the horizontal movement device (35) in such a manner that the irradiation unit (17), on completion of a first build process in the first build chamber (13a), is moved horizontally to the second build chamber (13b), and then to control the irradiation unit (17) in such a manner that it begins a new build process in the second build chamber (13b).

8. A method for producing three-dimensional workpieces (15), comprising: - applying raw material powder (9) to a carrier (7) by means of a powder application device (21), wherein the raw material powder (9) applied to the carrier (7) is laterally delimited and supported by a build chamber wall (11, 11a, 11b) extending substantially vertically, - selectively irradiating the raw material powder (9) applied to the carrier (7) with electromagnetic radiation or particle radiation by an irradiation unit (17) in order to produce on the carrier (7) a workpiece (15) manufactured from the raw material powder (9) by an additive layer building method, wherein the irradiation unit (17) comprises at least one optical element, and - moving the irradiation unit (17) vertically with respect to the carrier (7) by means of a vertical movement device (31), while the build chamber wall (11, 11a, 11b) and the carrier (7) are connected to one another in a stationary manner, so that the vertical movement takes place relative to the carrier (7) and relative to the build chamber wall (11, 11a, 11b), and - moving the powder application device (21) over the carrier (7) in a horizontal direction by means of a horizontal movement device, wherein the build chamber wall (11, 11a, 11b) is rigidly connected to the carrier (7) and / or to a base (5) of the device (1), or wherein the build chamber wall (11, 11a, 11b) is detachably connected to the carrier (7) and / or to the base (5) and is adapted to be detached from the carrier (7) on completion of a build process, in order to remove the finished workpiece (15), wherein the method further comprises: - directing a gas into a build chamber (13, 13a, 13b) defined by the build chamber wall (11, 11a, 11b) by means of at least one gas inlet (23) and drawing in the gas introduced from the gas inlet (23) by means of at least one gas outlet (25), wherein the gas inlet (23) and the gas outlet (25) generate a gas stream flowing substantially parallel to the carrier (7), wherein the gas outlet (25) is arranged opposite of the gas inlet (23) in a direction of gas stream generated by the gas inlet (23), wherein during the vertical movement, the vertical movement device (31) moves the irradiation unit (17) vertically together with the gas inlet (23) and the gas outlet (25), wherein the device (1) comprises a plurality of irradiation units (17) arranged side by side, each of which comprises at least one optical element and each of which is adapted to scan an electromagnetic beam or a particle beam over the raw material powder (9), and wherein the vertical movement device (31) moves the plurality of irradiation units (17) together vertically with respect to the carrier (7).

9. The method as claimed in claim 8, further comprising: - moving the powder application device (21) vertically by means of a further vertical movement device which is mechanically independent of the vertical movement device (31).

10. The method as claimed in claim 8 or 9, further comprising: - moving the irradiation unit (17) horizontally from a first build chamber (13a) to a second build chamber (13b) by means of a horizontal movement device (35), on completion of a build process in the first build chamber (13a), and - beginning a build process in the second build chamber (13b).