ADDITIVE MANUFACTURING METHOD FOR CONTINUOUSLY PRODUCING MOLDED BODIES, AND CORRESPONDING APPARATUS

Abstract

Apparatus for continuously producing a molded body by an additive manufacturing method includes a processing region receiving a powder applied layer-by-layer to form a molded body, and a separation device having a separation element which can be introduced into the processing region to form chambers in the processing region. The separation device further includes a drive to move the separation element such as to lower the chambers in a vertical direction during the layer-by-layer processing from a treatment portion of the processing region to a removal portion of the processing region, and to remove the separation element in the removal portion of the processing region at least in part from the processing region for opening a lower one of the chambers so that the molded body is able to fall or slide out of the processing region.

Claims

1.-15. (canceled)

16. Apparatus for continuously producing a molded body by an additive manufacturing method, said apparatus comprising: a processing region receiving a powder and configured to allow execution of a layer-by-layer processing of at least part of the powder to form a molded body by the additive manufacturing method; and a separation device comprising a separation element introducible into the processing region to form chambers in the processing region, and a drive designed to move the separation element such as to lower the chambers in a vertical direction during the layer-by-layer processing from a treatment portion of the processing region to a removal portion of the processing region, and to remove the separation element in the removal portion of the processing region at least in part from the processing region for opening a lower one of the chambers so that the molded body is able to fall or slide out of the processing region.

17. The apparatus of claim 16, further comprising a receiving device designed to receive the molded body fallen or slid out of the processing region.

18. The apparatus of claim 17, wherein the receiving device comprises a conveyor element in order to transport the molded body away from the processing region.

19. The apparatus of claim 18, further comprising a postprocessing device designed to post process the molded body transported by the conveyor element.

20. The apparatus of claim 19, wherein the postprocessing device is designed to treat the molded body by at least one process selected from the group consisting of sandblasting, polishing, grinding, tamping, coating, heat treatment, and coloring.

21. The apparatus of claim 17, further comprising a powder feeding device designed to feed the powder layer by layer to the processing region, said powder feeding device being coupled to the receiving device so as to allow powder that has accumulated in the receiving device as the molded body falls or slides out to be fed back to the processing region.

22. The apparatus of claim 17, wherein the receiving device comprises a perforated metal plate designed to receive the molded body that has fallen or slid out of the processing region, and a tray designed to receive powder that has accumulated in the receiving device and fallen through the perforated metal plate when the molded body falls or slides out.

23. The apparatus of claim 16, wherein the processing region comprises a cooling zone designed to cool the molded body.

24. The apparatus of claim 23, wherein the cooling zone is designed in such a way that the molded body falls or slides out of the processing region as soon as the molded body reached a predefined end temperature.

25. The apparatus of claim 16, further comprising: a laser device for executing the additive manufacturing method; and shielding gas introduced in a region between the laser device and the treatment portion of the processing region, said region between the laser device and the treatment portion of the processing region being fluidically separated from the removal portion of the processing region.

26. The apparatus of claim 16, wherein the separation device comprises a plurality of said separation element, said drive designed to introduce the separation elements in the treatment portion of the processing region to the processing region, to remove the separation elements from the processing region after being lowered in the removal portion of the processing region, and to convey separation elements back to the treatment portion of the processing region.

27. The apparatus of claim 16, wherein the separation device comprises a helix-shaped element having at least one helical turn to form the separation element, said drive designed to rotate the helix-shaped element around an axis of rotation.

28. The apparatus of claim 16, wherein the additive manufacturing method is a process selected from the group consisting of selective laser sintering and binder jetting.

29. An additive manufacturing method for continuously producing a molded body, said method comprising: introducing powder into a processing region to produce a molded body layer by layer; inserting a separation element into the processing region to form chambers in the processing region; and moving the separation element such as to lower the chambers in a vertical direction during the layer-by-layer processing from a treatment portion of the processing region to a removal portion of the processing region, and to remove the separation element in the removal portion of the processing region at least in part from the processing region for opening a lower one of the chambers so that the molded body is able to fall or slide out of the processing region.

30. The method of claim 29, further comprising cooling the molded body in a cooling zone of the processing region.

Description

[0039] The above-described characteristics, features and advantages of this invention, as well as the manner in which these are realized, will become dearer and more readily understandable in connection with the following description of the exemplary embodiments, which are explained in more detail with reference to the drawings, in which:

[0040] FIG. 1 shows a schematic cross-sectional view of an apparatus for the continuous production of molded bodies by means of the additive manufacturing method according to one embodiment of the invention,

[0041] FIG. 2 shows a schematic cross-sectional view of a processing region comprising a separation device for an apparatus for the continuous production of molded bodies by means of an additive manufacturing method according to one embodiment of the invention,

[0042] FIG. 3 shows a schematic cross-sectional view of a further processing region comprising a separation device for an apparatus for the continuous production of molded bodies by means of an additive manufacturing method according to one embodiment of the invention, and

[0043] FIG. 4 shows a flowchart of an additive manufacturing method for the continuous production of molded bodies according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE FIGURES

[0044] FIG. 1 shows a schematic cross-sectional view of an apparatus 100 for the continuous production of molded bodies K1 to K7 by means of selective laser sintering, i.e. by means of an additive manufacturing method. The apparatus 100 comprises a laser device 1 which emits a laser beam. The apparatus further comprises a build chamber housing 6.

[0045] The apparatus 100 further comprises a chamber 2 which represents a processing region 2. The processing region 2 extends in the vertical direction from a treatment portion or irradiation portion B1, in which the processing of a powder takes place, to a removal portion B2 in which the molded bodies K1 to K7 are removed. The processing region 2 is filled with the powder, which is processed layer by layer by means of the emitted laser beam. Irradiating the powder causes a sintering process to take place, with the result that molded bodies K1 to K7 are produced layer by layer.

[0046] A separation device 3 comprises a drive 33 as well as separation elements 31a, 32a which are driven by means of the drive 33. The separation elements 31a, 32a form chambers 21, 22 in the processing region 2. The separation elements 31a, 32a are moved by means of the drive 33 in such a way that they are moved downward in the vertical direction to the removal portion B2. The separation elements 31a, 32a can be metal separating plates, for example, which are inserted automatically into the processing region 2 in the horizontal direction. After the separation elements 31a, 32a have been moved downward to the removal portion B2, they are moved out of the processing region 2 again in the horizontal direction. The separation elements 31a, 32a are moved by means of a mechanism that is driven by the drive 33 outside of the processing region 2 once more to the upper portion in the vicinity of the treatment portion B1 and reintroduced into the processing region 2. The separation device 3 is operated in such a way that at least one separation element 31a, 31b is contained in the processing region 2 at all times in order to form a processing chamber 21 in which the powder contained in the processing region 2 is processed by means of the laser beam.

[0047] Alternatively, it can also be provided that the separation elements 31a, 32a are introduced into the processing region 2 from above in the region of the treatment portion B1. The separation elements 31a, 32a are held and moved vertically downward by means of a vertically displaceable mechanism mounted at the side in the processing region 2. As soon as the metal separating plates 31a, 32a arrive in the removal portion B2, they are removed from below out of the processing region 2 again and transported back upward.

[0048] The drive 33 is preferably operated in discrete steps. Following each processing step, during which a layer of the powder is processed, the separation elements 31a, 32a are lowered further thereby. The apparatus 100 further comprises a powder dosing container 52 and a recoater 51, which form a powder feeding device 5. After the separation elements 31a, 32a have been lowered, powder is introduced from the powder dosing container 52 into the processing region 2 and smoothed by means of the recoater 51. As a result, a new powder layer is prepared for processing and is processed in turn by means of the laser beam. The powder dosing container 52 can likewise be moved in the vertical direction for this purpose so that new powder can be introduced.

[0049] The recoater 51 can also be embodied to smooth the powder layer once again after the insertion of the separation elements 31a, 32a. This enables irregularities in the surface of the powder which can be caused due to the insertion of the separation elements 31a, 32a to be removed again.

[0050] After the lowest separation element 31a, 32a is removed from the processing region 2, a lower chamber 22 is opened. The molded bodies K4, K5 contained therein are exposed as a result and slide out of the processing region 2 along with the powder contained in the lower chamber 22.

[0051] A shielding gas is introduced in a region between the laser device 1 and the treatment portion B1 of the processing region 2. The region between the laser device 1 and the treatment portion B1 of the processing region 2 is fluidically separated from the removal portion B2 of the processing region 2.

[0052] A receiving device 4 comprising a conveyor element 41 for receiving the molded bodies K6, K7 that have slid out of the processing region 2 is positioned below the processing region 2. The conveyor element 4 is for example a conveyor belt which transports the molded bodies K6, K7 away from the processing region 2 in the horizontal direction. The conveyor element 41 comprises a perforated metal plate and consequently has holes through which the powder falls into a tray 42 located under the conveyor element 41. The powder accumulating in the tray 42 can be supplied automatically to the powder feeding device 5. For example, the powder accumulating in the tray 42 can be introduced directly into the powder dosing container 52. Alternatively, a separate container can also be provided in order to separate powder that has already been used from the new powder. The already used powder can be reintroduced into the processing region 2 together with the new powder.

[0053] A postprocessing device can furthermore be provided which post processes the molded bodies K6, K7. For example, the molded bodies K6, K7 can be postprocessed directly on the conveyor element 41. The molded bodies K6, K7 can be cleared of powder for example by means of a vacuum cleaner or by means of compressed air. Further processing steps can include sandblasting methods, polishing methods, grinding methods, tamping methods, coating methods, heat treatment methods, and/or coloring methods.

[0054] Also provided is a cooling zone 23 which cools a lower section of the processing region 2. The cooling zone 23 comprises cooling elements which can also be integrated into the processing region 2. In the cooling zone 23, the finished molded bodies K4, K5 are cooled down to a predefined end temperature. The cooling zone 23 is preferably dimensioned in such a way that the molded bodies K1 to K7 fall or slide out from the processing region 2 shortly after reaching the end temperature (for example within minutes of reaching the end temperature). This prevents the molded bodies K1 to K7 from remaining in the processing region 2 for longer than necessary.

[0055] The Invention is not limited to the embodiment shown. In particular, depending on application case, an appropriately chosen number of molded bodies K1 to K7 can be contained in the apparatus 100 at the same time. Furthermore, an arbitrarily chosen number of separation elements 31a, 32a can be provided.

[0056] Moreover, the apparatus can also be embodied for producing molded bodies by means of other additive manufacturing methods, in particular by means of binder jetting methods. For this purpose, the powdered starting material can be adhesively bonded at predefined points by means of a binder. The rest of the construction of the apparatus 100 can correspond to the embodiment shown in FIG. 1.

[0057] FIG. 2 shows a schematic cross-sectional view of a processing region 2 having a separation device for an apparatus for the continuous production of molded bodies K1 to K7 by means of an additive manufacturing method. In this case the separation device comprises a helix-shaped element 31b having at least one helical turn. The at least one helical turn 31b forms the at least one separation element. The drive incrementally rotates the helix-shaped element around an axis of rotation A after each processing step. This causes the molded bodies K1 to K7 to be conveyed downward. A closing mechanism (not shown) is also provided in order to ensure that only at least one of the fully finished molded bodies slides out at any given time.

[0058] FIG. 3 shows a schematic cross-sectional view of a further processing region 2 having a separation device for an apparatus for the continuous production of molded bodies by means of an additive manufacturing method. In this case separation elements 31c, 32c can be introduced into the processing region 2 from two different sides.

[0059] FIG. 4 shows a flowchart of an additive manufacturing method for the continuous production of molded bodies K1 to K7, in particular by means of selective laser sintering or binder jetting.

[0060] In a first method step S1, a powder is introduced into a processing region 2 for the purpose of producing the molded bodies K1 to K7. The powder is processed layer by layer by means of the additive manufacturing method. In this case at least one separation element is or has been introduced into the processing region 2 in such a way that chambers 21, 22 are or have been formed in the processing region 2. The at least one separation element is moved in the vertical direction such that the chambers 21, 22 are lowered in the vertical direction during the layer-by-layer processing from a treatment portion B1 of the processing region 2 to a removal portion B2 of the processing region 2. The at least one separation element in the removal portion B2 of the processing region 2 is removed at least in part from the processing region 2 in such a way that a lower of the chambers 21, 22 is opened so that the produced molded bodies K1 to K7 fall or slide out of the processing region 2.

[0061] In a second method step S2, following their production, the molded bodies K1 to K7 are cooled in a cooling zone 23 of the processing region 2.

[0062] In a third method step S3, the molded bodies K1 to K7 are transported away from the processing region 2 by means of a conveyor element 41.

[0063] In a fourth method step S4, a further postprocessing of the molded bodies K1 to K7 takes place, for example by means of sandblasting methods, polishing methods, grinding methods, tamping methods, coating methods, heat treatment methods, and/or coloring methods. Further, the molded bodies K1 to K7 can additionally be depowdered.

[0064] Although the invention has been illustrated and described in greater detail on the basis of the preferred exemplary embodiments, the invention is not limited by the disclosed examples and other variations may be derived herefrom by the person skilled in the art without leaving the scope of protection of the invention.