APPLICATION UNIT

Abstract

Application unit (4) for an apparatus (1) for additively manufacturing of three-dimensional objects (2) by means of successive irradiation and consolidation of layers of a build material (3) which can be consolidated by means of an energy beam, which application unit (4) is adapted to apply build material (3) onto a build plane (5) and/or a previously applied layer (6) of build material (3), wherein the application unit (4) is adapted to selectively apply build material (3) onto at least one application region (7) of the build plane (5) or of the previously applied layer (6), wherein at least one application element (8, 21) is provided that is adapted to transfer build material (3) previously applied onto an application surface (9) of the application element (8, 21) to the application region (7), wherein an adhesion unit (10, 20, 22) is provided that is adapted to adjust an adhesion ability for build material (3) of the application surface (9) of the application element (8, 21) and/or an adhesion ability of the build material (3).

Claims

1. Application unit (4) for an apparatus (1) for additively manufacturing of three-dimensional objects (2) by means of successive irradiation and consolidation of layers of a build material (3) which can be consolidated by means of an energy beam, which application unit (4) is adapted to apply build material (3) onto a build plane (5) and/or a previously applied layer (6) of build material (3), wherein the application unit (4) is adapted to selectively apply build material (3) onto at least one application region (7) of the build plane (5) or of the previously applied layer (6), characterized by at least one application element (8, 21) adapted to transfer build material (3) previously applied onto an application surface (9) of the application element (8, 21) to the application region (7), wherein an adhesion unit (10, 20, 22) is provided that is adapted to adjust an adhesion ability for build material (3) of the application surface (9) of the application element (8, 21) and/or an adhesion ability of the build material (3).

2. Application unit according to claim 1, characterized in that the adhesion unit (10, 20, 22) is adapted to selectively increase, in particular to generate, the adhesion ability of the application surface (9) of the application element (8, 21) and/or to selectively decrease, in particular remove, the adhesion ability of the application surface (9) of the application element (8, 21).

3. Application unit according to claim 1, characterized in that the adhesion unit (10, 20, 22) is adapted to selectively increase the adhesion ability of the application surface (9) of the application element (8, 21) in at least one transfer region (19) of the application element (8, 21) corresponding to the application region (7).

4. Application unit according to claim 1, characterized in that the adhesion unit (10, 20, 22) is adapted to selectively decrease the adhesion ability of the application surface (9) of the application element (8, 21) in at least one complementary region of the application element (8, 21) complementary to the application region (7).

5. Application unit according to claim 1, characterized in that the adhesion ability is passively adjustable, in particular via a contact pressure and/or a residual heat of a previously irradiated layer of build material (3), and/or that the adhesion unit (10, 20, 22) is adapted to adjust the adhesion ability actively, in particular via charging and/or magnetizing and/or bonding and/or heating.

6. Application unit according to claim 1, characterized in that the adhesion unit is adapted to adjust an adhesion ability for build material (3) of the application surface (9) of the application element (8, 21) by generating a suction stream or a vacuum applied in the region of the application surface (9) of the application element (8, 21).

7. Application unit according to claim 1, characterized in that the at least one application region (7) essentially equals the cross section of the respective layer of the object (2) to be built and/or the cross section of the respective layer of at least one support structure, in particular a wall or a support element.

8. Application unit according to claim 1, characterized in that the application element has a plate-like shape or the application element (8, 21) has a rotational symmetric shape and/or is built as a roller, in particular as a cylindrical roller.

9. Application unit according to claim 1, characterized in that the application element (8, 21) is adapted to selectively apply build material (3) via a rollover movement of the application element (8, 21), wherein the application element (8, 21) is moveable relative to the build plane (5) and/or a previously applied layer (6) of build material (3) in that the rollover movement is provided.

10. Application unit according to claim 1, characterized by a build material supply unit (11, 23) adapted to apply build material (3) onto the application element (8, 21), in particular by supplying build material (3) directly contacting an application surface (9) of the application element (8, 21).

11. Application unit according to claim 10, characterized in that the application element (8, 21) is moveably, in particular rotatably, arranged with respect to the build material supply unit (11, 23).

12. Application unit according to claim 1, characterized in that a layer thickness layers of build material (3) applied on the application surface (9) and/or on the application region (7) is adjustable dependent on at least one application parameter, in particular corresponding to a contact pressure between the application element (8, 21) and the application region (7) and/or the build material supply unit (11, 23) and/or corresponding to a rotational speed of the application element (8, 21).

13. Application unit according to claim 1, characterized by a conditioning unit (17) adapted to condition, in particular to clean, the application unit (4), in particular the application surface (9) of the application element (8, 21).

14. Apparatus (1) for additively manufacturing of three-dimensional objects (2) by means of successive irradiation and consolidation of layers of a build material (3) which can be consolidated by means of an energy beam, which apparatus (1) comprises at least one application unit (4), in particular an application unit (4) according to claim 1 adapted to apply build material (3) onto a build plane (5) and/or a previously applied layer (6) of build material (3), wherein the application unit (4) is adapted to selectively apply build material (3) onto at least one application region (7) of the build plane (5) or of the previously applied layer (6), wherein at least one application element (8, 21) adapted to transfer build material (3) previously applied onto an application surface (9) of the application element (8, 21) to the application region (7), wherein an adhesion unit (10, 20, 22) is provided that is adapted to adjust an adhesion ability for build material (3) of the application surface (9) of the application element (8, 21) and/or an adhesion ability of the build material (3).

15. Method for operating an apparatus (1) for additively manufacturing of three-dimensional objects (2) by means of successive irradiation and consolidation of layers of a build material (3) which can be consolidated by means of an energy beam, particularly by use of an apparatus according to claim 14, wherein build material (3) is selectively applied onto at least one application region (7) of a build plane (5) or of a previously applied layer (6), characterized in that an adhesion ability for build material (3) of the application surface (9) of the application element (8, 21) and/or an adhesion ability of the build material (3) is adjusted.

Description

[0044] Exemplary embodiments of the invention are described with reference to the Fig. The Fig. are schematic diagrams, wherein

[0045] FIG. 1 shows an inventive apparatus according to a first embodiment of the invention;

[0046] FIG. 2 shows a top view of the inventive apparatus of FIG. 1;

[0047] FIG. 3 shows an inventive apparatus according to a second embodiment of the invention; and

[0048] FIG. 4 shows an inventive apparatus according to a third embodiment of the invention.

[0049] FIG. 1 shows an apparatus 1 for additively manufacturing three-dimensional objects 2 by means of successive irradiation and consolidation of layers of a (non-consolidated) build material 3 which can be consolidated by means of an energy beam (not shown). The apparatus 1 comprises an application unit 4 that is adapted to apply the build material 3 onto a build plane 5 and/or a previously applied layer 6 of build material 3.

[0050] The application unit 4 is adapted to selectively apply the non-consolidated build material 3 onto an application region 7 of the build plane 5 (according to this embodiment the build plane 5 coincides with the previously built layer 6). The application unit 4 further comprises an application element 8 comprising an application surface 9 which is basically the shell surface of the application element 8 that is, for example, built as a cylindrical roller or drum. Thus, build material 3 may be applied to the application surface 9 of the application element 8 and subsequently be transferred to the application region 7 of the build plane 5.

[0051] In other words, non-consolidated build material 3 can be selectively applied onto the application surface 9 that is the shell surface of the application element 8 and be depleted onto the top layer 6 of the previously built object 2. To selectively apply the build material 3 onto the application surface 9 the application unit 4 comprises an adhesion unit 10 that is adapted to adjust an adhesion ability for build material 3 of the application surface 9 of the application element 8. It is also possible that the adhesion unit 10 is adapted to adjust an adhesion ability of the build material 3.

[0052] According to this embodiment of the invention, the adhesion unit 10 is adapted to change the electric charge of the application surface 9 by generating an energy beam 11, for example a laser beam, and guide the generated energy beam 11 selectively over the application surface 9 to adjust the adhesion ability for build material 3 of the application surface 9 in different regions of the application surface 9. The generated energy beam 11 that has been generated by the adhesion unit 10 must not be confused with the energy beam (not shown) generated by an irradiation device (not shown) of the apparatus 1 which is used to irradiate and consolidate the build material in the build plane 5.

[0053] The application unit 4 further comprises a build material supply unit 11 that supplies build material 3 to the application element 8. In particular, the build material supply unit 11 brings build material 3 in direct contact with the application surface 9, in particular a part of the application surface 9 that has already been treated via the adhesion unit 10. Dependent on the adjustment of the adhesion ability the adhesion unit 10 has performed, build material 3 selectively adheres to the application surface 9 of the application element 8. In other words, the adhesion unit 10 increases (decreases) the adhesion ability for build material 3 of the application surface 9 in at least one region of the application surface 9 that corresponds (is complementary) to the next layer of build material 3 that has to be applied onto the previously built layer 6 of the object 2. Thus, build material 3 can only (cannot) adhere to the regions treated by the adhesion unit 10.

[0054] The application element 8 is pivoted and rotatably mounted about a rotational axis 12. Thus, the application element 8 is rotatably movable (as depicted by an arrow 13). The application unit 4 is translatory movable in X-, Y- and Z-direction (indicated by arrows 14-16). Thus, due to the rollover movement of the application element 8 build material 3 that adheres to the application surface 9 can be depleted onto the top layer 6 of the previously built object 2, i.e. in the application region 7.

[0055] The application unit 4 further comprises a conditioning unit 17 used to restore the initial condition of the application element 8, in particular the application surface 9 of the application element 8. The conditioning unit 17 is used to clean the application surface 9, for example by removing build material 3 that still sticks to the application surface 9 after the transfer of build material 3 to the application region 7. The conditioning unit 17 is further used to prepare the application surface 9 before it is again treated with the adhesion unit 10, for example, the conditioning unit 17 restores the electric charge status of the application surface 9 to an initial condition, e.g. to uncharged.

[0056] The application unit 4 is built as a combined module, wherein the application element 8, the adhesion unit 10, the build material supply unit 11 and the conditioning unit 17 form a combined module that is laterally movable (depicted by arrows 14-16) with respect to a build plate 18 carrying the previously built object 2.

[0057] FIG. 2 shows the apparatus 1 of FIG. 1 in a top view. As can be derived from FIG. 2, the adhesion unit 10 adjusts the adhesion ability of the application surface 9 in that build material 3 only adheres in a transfer region 19, in which the adhesion unit 10 increased the adhesion ability for build material 3 of the application unit 9. To deplete the adhered build material 3 the application unit 4 can be moved laterally (depicted by the arrows 14-16) to bring the build material 3 arranged in the transfer region 19 in contact with the application region 7, i.e. onto the top layer 6 of the object 2.

[0058] By using the residual heat of the previously built layer 6, the build material 3 arranged in the transfer region 19 is detached from the application surface 9, as the residual heat thermally weakens the adhesion ability of the respective transfer region 19 of the application surface 9. Additionally, the application unit 4, in particular the transfer region 19 may be pressed onto the top layer 6 to apply a defined pressure in that the build material 3 arranged in the transfer region 19 is applied onto the top layer 6 or the application region 7, respectively.

[0059] FIG. 3 shows an inventive apparatus 1 according to a second embodiment of the invention. The general set up according to the apparatus 1 depicted in FIG. 3 is analog to the first embodiment of the inventive apparatus 1 as depicted in the FIG. 1, 2. Thus, the same reference signs are used for the same parts.

[0060] Deviant from the apparatus 1 depicted in FIG. 1, 2, the apparatus 1 as shown in FIG. 3 comprises an adhesion unit 10 that is adapted to selectively decrease the adhesion ability of the application surface 9 of the application element 8. The application unit 4 further comprises a second adhesion unit 20 that is adapted to uniformly change the adhesion ability of the application surface 9 as it passes the second adhesion unit 20, for example, adapted to uniformly increase or decrease the adhesion ability of the application surface 9. Subsequently, the adhesion unit 10 is used to change the adhesion ability for build material 3 of the application surface 9.

[0061] For example, the second adhesion unit 20 uniformly increases the adhesion ability for build material 3 of the entire application surface 9 as it passes the second adhesion unit 20. Subsequently when passing the adhesion unit 10, the adhesion unit 10 selectively decreases the adhesion ability for build material 3 of the application unit 9 in regions complementary to the transfer region 19 (the region in which build material 3 is desired). Build material 3 can therefore, adhere to the transfer region 19, ash the adhesion unit 20 uniformly increased the adhesion ability but build material cannot adhere to the complementary region, since the adhesion ability was again decreased by the adhesion unit 10.

[0062] Thus, the basic function of the application unit 4 or the inventive apparatus 1 depicted in FIG. 3 follows the principle as described with respect to the FIGS. 1 and 2.

[0063] FIG. 4 shows an inventive apparatus 1 according to a second embodiment of the invention. Deviant from the apparatus 1 depicted in FIGS. 1-3 the apparatus 1 as shown in FIG. 4 comprises an adhesion unit 22 that is adapted to selectively increase or decrease the adhesion ability of the application surface 9 of the application element 21. The application element 21 is built as a plate, wherein build material 3 is applied onto a bottom side of the application element 21. In other words, the application surface 9 is located bottom sides of the plate-like application element 21. To apply build material 3 onto the application surface 9 a build material supply unit 23 is provided that is adapted to selectively apply build material to a transfer region 19 of the application surface 9.

[0064] The basic function of the adhesion unit 22 of the inventive apparatus 1 depicted in FIG. 4 follows the principle as described with respect to the FIGS. 1-3. It is also possible that the application element 21 is turned in that build material 3 is applied top sides via the build material supply unit 23 and that the application element 21 is subsequently turned.

[0065] Build material 3 applied onto the application surface 9 of the application element 21 can be transferred to the application region 7 of the object 2. Therefore, the application element 21 can be pressed onto the object 2 or the build plane 6, respectively. Thus, the layer of build material 3 arranged on the application surface 9 can be stamped onto the application region.

[0066] Even if not depicted in the Fig., the adhesion unit 10, 20, 22 may be adapted to adjust an adhesion ability for build material 3 of the application surface 9 of the application element 8 by generating a suction stream or a vacuum applied in the region of the application surface 9 of the application element. 8 Hence, build material 3 may be temporarily adhered to the application surface 9 of the application element 8 by a suction stream or a vacuum applied in the region of the application surface 9 of the application element 8. The application surface 9 of the application element 8 may be provided with openings (not shown), e.g. arranged in an array or the like, so that the suction stream or vacuum, respectively may interact with the build material 3 so that the build material 3 may adhere to the application surface 9. The suction stream or vacuum, respective may be generated by a suction stream generating unit (not shown), e.g. a suction pump, or a vacuum generating unit (not shown), e.g. a vacuum pump, assigned to the adhesion unit 10, 20, 22. Operation of a respective a suction stream generating unit or vacuum generating unit, respectively and respective operational parameters, particularly operational parameters which influence the adhesion generated by the suction stream or vacuum, respectively can be controlled by a control unit (not shown) of the suction stream generating unit or vacuum generating unit, respectively.