APPARATUS FOR ADDITIVE MANUFACTURING OF THREE-DIMENSIONAL OBJECTS

Abstract

An apparatus (1) for additive manufacturing of three-dimensional objects (2) by successive, selective layer-by-layer exposure and thus successive, selective layer-by-layer solidification of construction material layers of construction material (3) that can be solidified by means of an energy beam, comprising a filter device (7) provided for filtering process gas (9) arising in the course of performing additive construction processes in a process chamber (8) of the apparatus (1), especially containing impurities arising in relation to the process, wherein the filter device (7) comprises several filter modules (14) with a filter module housing (15) each, wherein every filter module housing (15) comprises a filter body receiving room (16) configured with a defined geometry provided for receiving a defined number of filter bodies (18) configured with a defined geometry, wherein every filter module (14) comprises connection interfaces (19, 20) on the filter module via which it is or can be connected, if required, to defined connection areas (21, 22) of a pipe structure (12) of the apparatus that is or can be flown through by the process gas (9).

Claims

1. An apparatus (1) for additive manufacturing of three-dimensional objects (2) by successive, selective layer-by-layer exposure and thus successive, selective layer-by-layer solidification of construction material layers of construction material (3) that can be solidified by means of an energy beam, comprising a filter device (7) provided for filtering process gas (9) arising in the course of performing additive construction processes in a process chamber (8) of the apparatus (1), especially containing impurities arising related to the process, characterized in that the filter device (7) comprises several filter modules (14) with a filter module housing (15) each, wherein every filter module housing (15) comprises a filter body receiving room (16) configured with a defined geometry, provided for receiving a defined number of filter bodies (18) configured with a defined geometry, wherein every filter module (14) comprises connection interfaces (19, 20) on the filter module via which it is or can be connected, if required, to defined connection areas (21, 22) of a pipe structure (12) of the apparatus that is or can be flown through by the process gas (9).

2. An apparatus according to claim 1, characterized in that the filter body receiving rooms (16) of the respective filter module housings (15) differ with regard to their respective filter body receiving volumes, so that in every filter body receiving room (16) only a defined number of filter bodies (18) configured with a defined geometry can be received.

3. An apparatus according to claim 1, characterized in that a respective filter module (14) forms an assembly group that is or can be preconfigured and handled separately.

4. An apparatus according to claim 1, characterized in that the connection interfaces (19, 20) of all filter modules (14) are configured identically.

5. An apparatus according to claim 1, characterized in that only filter module housings (15) with a specific geometrically defined configuration, especially a specific length, can be connected to the connection areas (21, 22) of the apparatus, wherein all filter modules (14) of the filter device (7) have a respective geometrically defined configuration, especially a respective length.

6. An apparatus according to claim 1, characterized in that the filter body/bodies (18) received in a respective filter body receiving room (16) comprised in the filter module housing is/are received with a press fit in the respective filter body receiving room (16).

7. An apparatus according to claim 1, characterized in that every filter module (14) comprises a closure device (23) arranged or formed on the filter module housing, wherein a respective filter module housing (15) has an access opening that can be closed with the respective closure device (23) and forms an access option into the respective filter body receiving room (16).

8. An apparatus according to claim 7, characterized in that the closure device (23) comprises a cap-like closing element (24), possibly arranged or formed movably on the filter module housing (15).

9. An apparatus according to claim 1, characterized in that in every filter module housing (15) a flow channel structure (25) is formed that is or can be flown through by the process gas (9), wherein the flow channel structure (25) comprises a first flow channel structure section (25a) comprising an inflow section (26) for flowing the process gas (9) to be filtered into the filter module (14) and a second flow channel structure section (25b) comprising an outflow section (27) for flowing a filtered process gas (9) out of the filter module (14), wherein the filter body/bodies (18) received in the respective filter body receiving room (16) comprised in the filter module housing is/are arranged between the first and second flow channel structure section (25a, 25b).

10. A filter device (7) for an apparatus (1) for additive manufacturing of three-dimensional objects (2) by successive, selective layer-by-layer exposure and thus successive, selective layer-by-layer solidification of construction material layers of construction material (3) that can be solidified by means of an energy beam, characterized in that the filter device (7) comprises several filter modules (14) with a filter module housing (15) each, wherein every filter module housing (15) comprises a filter body receiving room (16) configured with a defined geometry, provided for receiving a defined number of filter bodies (18) configured with a defined geometry, wherein every filter module (14) comprises connection interfaces (19, 20) on the filter module via which it is or can be connected to defined connection areas (21, 22) of a pipe structure (12) of the apparatus that is or can be flown through by the process gas (9).

Description

[0026] The invention is explained in more detail by means of exemplary embodiments in the drawings. In which:

[0027] FIG. 1 shows a schematic diagram of an apparatus according to an exemplary embodiment; and

[0028] FIGS. 2, 3 each show a schematic diagram of a filter module according to an exemplary embodiment.

[0029] FIG. 1 shows a schematic diagram of an apparatus 1 according to an exemplary embodiment. FIG. 1 only shows the section of the apparatus 1 relevant to explaining the principle described in the following in a sectional view.

[0030] The apparatus 1 serves for additive manufacturing of three-dimensional objects 2, i.e., especially technical components or technical component groups, by successive, selective layer-by-layer exposure and thus successive, selective layer-by-layer solidification of construction material layers of construction material 3 that can be solidified, i.e., for example, metal powder, by means of a laser beam 5. The selective solidification of respective construction material layers to be solidified is performed based on object-related construction data. Respective construction data describe the geometric or geometric structural design of the respective object 2 to be manufactured additively and can, for example, include sliced CAD data of the object 2 to be manufactured. The apparatus 1 can be formed as a LaserCUSING apparatus, i.e., as an apparatus for performing selective laser melting methods.

[0031] The apparatus 1 comprises the functional components required to perform additive construction processes, including a coating device (not shown) provided for forming construction material layers to be solidified selectively (in the construction plane of the apparatus 1) and an exposure device 4 provided for selectively exposing construction material layers to be solidified selectively (in the construction plane of the apparatus 1). The coating device comprises several components, namely a coating element comprising an, especially blade-shaped, coating tool and a guiding device for guiding the coating element along a defined movement path. The exposure device 4 comprises several components as well (not shown in detail), namely a beam generation device for generating the laser beam 5, a beam deflection device for deflecting the laser beam 5 generated by the beam generation device onto an area to be exposed of a construction material layer to be solidified selectively, and diverse optical elements (not shown) such as objective elements, lens elements, etc., which are typically arranged between the beam generation device and the beam deflection device.

[0032] The mentioned functional components of the apparatus 1 are arranged or formed on or in a process chamber 8 of the apparatus 1. The process chamber 8 is rendered inert, i.e., filled with an inert gas such as argon, nitrogen, etc.

[0033] The apparatus 1 furthermore comprises a filter device 7. The filter device 7 is provided for filtering process gas 9 arising in the course of performing additive construction processes in the process chamber 8 of the apparatus 1, especially containing impurities arising in relation to the process. The corresponding impurities in process gas to be filtered are especially smoke or smoulder particles arising in relation to the process and/or non-solidified construction material particles (weld spatters). The flow of the process gas 9 through the process chamber 8, i.e., the process gas flow, is indicated by the arrows.

[0034] Evidently, the filter device 7 is connected to a line or pipe structure 12 extending between an outflow opening 10 of the process chamber and an inflow opening 11 of the process chamber and comprising several pipe elements (not denoted in more detail). Furthermore connected to the line or pipe structure 12 is a pump device 13 provided for generating a suction flow that allows flowing of the process gas 9 through the line or pipe structure 12, i.e., also through the filter device 7. Evidently, a closed flow circuit is formed by the process chamber 8 and the line or pipe structure 12; hence, the process gas 9 flows between the process chamber 8 and the line or pipe structure 12 in a closed flow circuit.

[0035] The filter device 7 comprises several filter modules 14. Every filter module 14 comprises a filter module housing 15 comprising a filter body receiving room 16 configured with a defined geometry. The filter body receiving room 16 of a filter module 14 is provided for receiving (only) a defined number of filter bodies 18 configured with a defined geometry. A respective filter body receiving room 16 is configured with such a defined geometry, i.e., has such a geometric structural design, that, with regard to the filter bodies 18 that are or can be received therein, only the number of filter bodies 18 configured with a defined geometry defined for the respective filter module 14 can be received in it.

[0036] FIGS. 2, 3 each show a schematic diagram of a filter module 14 associated with the filter device 7 in a (longitudinal) sectional view.

[0037] The filter modules 14 shown in FIGS. 2, 3 each have a filter module housing 15 or a filter body receiving room 16 with a (hollow) cylindrical base shape with given dimensions, i.e., a given outside and inside radius and a given height. Due to their given dimensions, the respective filter body receiving rooms 16 are configured with a defined geometry. Due to their respective geometrically defined configuration, the filter body receiving rooms 16 can each receive only a defined number of filter bodies 18 configured with a defined geometry, i.e., in the exemplary embodiment filter bodies 18 with a ring-shaped base shape, the outside and inside radius and height or total height of which are adapted to the dimensions of the respective filter body receiving room 16.

[0038] In the filter body receiving room 16 of the filter module 14 shown in FIG. 2, five filter bodies 18 can be received, whereas in the filter body receiving room 16 of the filter module 14 shown in FIG. 3, just one (single) filter body 18 can be received.

[0039] The respective filter body receiving rooms 16 therefore have a spatially defined filter body receiving room volume (volume) in which (only) the respective defined number of filter bodies 18 configured with a defined geometry is or can be received. As results from FIG. 3, a defined number of filter bodies configured with a defined geometry is also understood to mean a number of one, i.e., a filter body receiving room 16 can also receive just one (single) filter body 18 configured with a defined geometry. It might also be imaginable to arrange in the exemplary embodiment shown in FIG. 2 one single elongated filter body 18 the height of which corresponds to the total height of the five individual filter bodies 18. Due to its comparably larger height, the elongated filter body 18 has a different geometrically defined configuration than the individual filter bodies 18.

[0040] Therefore, the filter module housings 15 of the filter modules 14 differ in the respective defined number of filter bodies 18 configured with a defined geometry that are or can be received in the respective filter body receiving rooms 16 configured with a defined geometry comprised in the filter module housing. Hence, the filter body receiving rooms 16 of the respective filter module housings 15 differ in their respective filter body receiving volumes, wherein, as mentioned, every filter body receiving room 16 can receive only a defined number of filter bodies 18 configured with a defined geometry.

[0041] From FIGS. 2, 3 it can be seen that, starting out from filter bodies 18 with a specific geometrically defined configuration, i.e., here ring-shaped filter bodies 18 with a given outside and inside radius and a given height, a first filter module 14 comprises a filter body receiving room 16 in which a first number of such filter bodies 18 is or can be received, and a second (or further) filter module 14 comprises a filter body receiving room 16, in which a second number, which is different from the first number, of such filter bodies 18 is or can be received. As mentioned, in the filter body receiving room 16 of the filter module 14 shown in FIG. 2, five filter bodies 18 can be received and in the filter body receiving room 16 of the filter module 14 shown in FIG. 3, just one (single) filter body 18 can be received.

[0042] From FIG. 2 it can furthermore be seen that, if several filter bodies 18 are received in a filter body receiving room 16, these can be arranged stack-type on top of each other. The here ring-shaped filter bodies 18 are arranged aligned with each other; the respective interiors defined by the filter body are aligned with each other. To ensure a (position-) stable arrangement of the filter bodies 18 in respective filter body receiving rooms 16, the filter bodies 18 are received with a force or press fit in the respective filter body receiving rooms 16.

[0043] From FIGS. 2, 3 it can furthermore be seen that every filter module 14 comprises two connection interfaces 19, 20, via which it is or can be connected, if required, to a defined connection area 21, 22 of the line or pipe structure 12 of the apparatus that is or can be flown through by the process gas 9 that is or can be filtered. The connection areas 21, 22 of the apparatus comprise connecting pieces (not denoted in more detail) comprising flange areas. The filter modules 14 can therefore be exchanged if required to ensure efficient operation of the filter device 7 for a specific additive construction process. A filter device 7 with a variably adaptable filter size is thus provided. The filter size is conditional upon the use of different filter modules 14 or the different number of filter bodies 18 received in the filter body receiving rooms 16 of the filter module housings 15 of the respective filter modules 14.

[0044] Respective connection interfaces 19, 20 on the filter module comprise suitable fastening and sealing elements (not shown). Respective connection interfaces 19, 20 on the filter module can also be formed as connecting pieces comprising flange areas with respective fastening and sealing elements. Respective fastening elements can be provided for fastening a filter module 14 in a firm stabilized position to the connection areas 21, 22 of the apparatus. A fastening element can allow, e.g., form-locked and/or force-locked fastening of the filter module 7 to the connection areas 21, 22 of the apparatus. A fastening element allowing form-locked and/or force-locked fastening of a filter module 7 to a connection area 21, 22 of the apparatus can be, e.g., a fastening or clamping clip. Respective fastening elements can therefore be, e.g., subring-type or full ring-type or -shaped fastening or clamping clips. Respective sealing elements can be, e.g., sealing rings.

[0045] The connection interfaces 19, 20 of all filter modules 14 are configured identically; this facilitates any required exchange of respective filter modules 14.

[0046] The respective filter modules 14 therefore form preconfigurable or preconfigured assembly groups that can be handled separately. The handling of respective filter modules 14 is hence facilitated; filter modules 14 can be handled or exchanged smoothly, especially also automatably or automatedly.

[0047] Evidently, only filter modules 14 or filter module housings 15 with a specific geometrically defined configuration, especially a specific length, are connectible to the connection areas 21, 22 of the apparatus; therefore, only filter modules 14 or filter module housings 15 with a specific geometrically defined configuration, especially a specific length, can be connected to the connection areas 21, 22 of the apparatus. Therefore, the filter modules 14 have a corresponding geometrically defined configuration, especially a corresponding length, which allows precisely fitting connection of the filter modules 14 to the connection areas 21, 22 of the apparatus. The total length L of the filter modules 14 or filter module housings 15 shown in FIGS. 2, 3 is identical.

[0048] In every filter module housing 15, a flow channel structure 25 is formed that can be or, during operation of the filter device 7, is flown through by the process gas 9 or the process gas flow. The flow channel structure 25 comprises a first flow channel structure section 25a comprising a tubular inflow section 26 for flowing the process gas 9 to be filtered or a process gas flow to be filtered into the filter module 14 and a second flow channel structure section 25b comprising a tubular outflow section 27 for flowing the filtered process gas 9 or the filtered process gas flow out of the filter module 14. The two flow channel structure sections 25a, 25b communicate with each other. The filter body/bodies 18 received in the respective filter body receiving room 16 are arranged between the first and second flow channel structure section 25a, 25b. In the first flow channel structure section 25a, an exemplarily conical flow guidance element 28 is arranged, which purposefully guides the process gas 9 to be filtered to the filter bodies 18.

[0049] Every filter module 14 optionally comprises a closure device 23 arranged or formed on the filter module housing. The respective filter module housings 15 have an access opening (not denoted in more detail) that can be closed with the respective closure device 23 and forms an access option into the respective filter body receiving room 16. The interaction of the closure device 23 and the access opening allows a possibly required, i.e., for example, for service purposes, exchange of a (or several) filter body/bodies 18.

[0050] The closure device 23 comprises a cap-like closing element 24, possibly arranged or formed movably on the filter module housing 15. In the exemplary embodiments shown in FIGS. 2, 3, the closing element 24 is formed by a part of the first flow channel structure section 25a comprising the tubular inflow section 26.

[0051] The closing element 24 is movably (pivotingly) supported between an open position in which the closing element 24 is moved relatively to the access opening such that accessing the filter body receiving room 16 is possible, and a closed position shown in FIGS. 2, 3 in which the closing element 24 is moved relatively to the access opening such that accessing the filter body receiving room 16 is not possible. In the closed position, the closing element 24 is typically moved relatively to the access opening, i.e., especially towards the access opening, such that the filter body receiving room 16 is closed fluid-tightly.