DETERMINATION DEVICE FOR DETERMINING AT LEAST ONE PARAMETER OF AN ENERGY BEAM

Abstract

Determination device (1) for determining at least one parameter of an energy beam (5) for an apparatus (3) for additively manufacturing three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam (5), wherein the determination device (1) comprises a beam guiding element (12) adapted to guide the energy beam (5) to a determination unit (7) which is adapted to determine at least one parameter of the energy beam (5), wherein the determination unit (7) and the beam guiding element (12) are arranged as a determination assembly in a defined spatial arrangement relative to each other, wherein the determination assembly is movable, in particular rotatable, into at least a first and a second determination position, wherein the determination unit (7) is adapted to receive the energy beam (5) being guided to a first spatial position from the beam guiding element (12) in the first determination position and to receive the energy beam (5) being guided to a second spatial position from the beam guiding element (12) in the second determination position.

Claims

1. Determination device (1) for determining at least one parameter of an energy beam (5) for an apparatus (3) for additively manufacturing three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam (5), characterized by at least a beam guiding element (12) adapted to guide the energy beam (5) to a determination unit (7) which is adapted to determine at least one parameter of the energy beam (5), wherein the determination unit (7) and the beam guiding element (12) are arranged as a determination assembly in a defined spatial arrangement relative to each other, wherein the determination assembly is movable, in particular rotatable, into at least a first and a second determination position, wherein the determination unit (7) is adapted to receive the energy beam (5) being guided to a first spatial position from the beam guiding element (12) in the first determination position and to receive the energy beam (5) being guided to a second spatial position from the beam guiding element (12) in the second determination position.

2. Determination device according to claim 1, characterized in that the beam guiding element (12) and the determination unit (7) are mounted to a determination body (8), in particular a determination plate, which determination body (8) is moveable, in particular rotatable with respect to a rotation axis (11).

3. Determination device according to claim 1, characterized in that the determination body (8) is round, in particular circular.

4. Determination device according to claim 2, characterized in that the determination unit (7) is arranged centrally with respect to the beam guiding element (12), in particular on the rotation axis (11) of the determination body (8).

5. Determination device according to claim 1, characterized in that the beam guiding element (12) is moveable between two determination positions via a rotational movement around the determination unit (7), wherein the beam guiding element (12) is arranged facing towards the determination unit (7).

6. Determination device according to claim 1, characterized in that the beam guiding element (12) is built as or comprises a reflective element for reflecting the energy beam (5) towards the determination unit (7), in particular a parabolic mirror.

7. Determination device according to claim 1, characterized in that the beam guiding element (12) is adapted to collimate the energy beam (5).

8. Determination device according to claim 1, characterized in that the determination assembly is adapted to rotate in the at least two determination positions in a predefined order, in particular corresponding to a sequence in which the energy beam (5) is guided to the at least two spatial positions.

9. Determination device according to claim 1, characterized by at least one central beam guiding element (14) that is arranged above the determination unit (7) and adapted to guide the energy beam (5) to the beam guiding element (12), wherein the determination unit (7) is adapted to receive the energy beam (5) from the beam guiding element (12).

10. Determination device according to claim 9, characterized in that the central beam guiding element (14) is mounted above the determination unit (7) via a frame (15), in particular an L-shaped frame.

11. Determination device according to claim 1, characterized in that the at least one parameter of the energy beam (5) comprises or relates to an irradiation parameter, preferably an intensity of the energy beam (5) and/or an intensity distribution of the energy beam (5) and/or a geometry of the energy beam (5), in particular a spot shape and/or a spot size.

12. Apparatus (3) for additively manufacturing three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam (5), wherein the apparatus (3) comprises a determination device (1) for determining at least one parameter of the energy beam (5), characterized in that the determination device (1) comprises a beam guiding element (12) adapted to guide the energy beam (5) to a determination unit (7) which is adapted to determine at least one parameter of the energy beam (5), wherein the determination unit (7) and the beam guiding element (12) are arranged as a determination assembly in a defined spatial arrangement relative to each other, wherein the determination assembly is movable, in particular rotatable, into at least a first and a second determination position, wherein the determination unit (7) is adapted to receive the energy beam (5) being guided to a first spatial position from beam guiding element (12) in the first determination position and to receive the energy beam (5) being guided to a second spatial position from the beam guiding element (12) in the second determination position.

13. Apparatus according to claim 12, characterized in that the irradiation device (4) of the apparatus (3) comprises at least two irradiation units, wherein the at least one determination device (1) is arranged in a perpendicular incidence position of an energy beam (5) guided via one of the irradiation units, wherein the energy beam (5) is incident perpendicular on the build plane (6) in the perpendicular incidence position.

14. Apparatus according to claim 13, characterized in that the determination device (1) comprises a moving device that is adapted to move the determination unit (7) and the beam guiding element (12) as a determination assembly between at least two different perpendicular incidence positions assigned to at least two different irradiation units of the irradiation device (4).

15. Method for operating an apparatus (3) for additively manufacturing three-dimensional objects by means of successive layerwise selective irradiation and consolidation of layers of a build material which can be consolidated by means of an energy beam (5), in particular an apparatus according to claim 12, characterized by guiding the energy beam (5) to a first spatial position positioning a beam guiding element (12) of a determination device (1) in a first determination position guiding the energy beam (5) to a determination unit (7) via the beam guiding element (12) positioned in the first determination position, wherein the determination unit (7) and the beam guiding element (12) are arranged as a determination assembly in a defined spatial arrangement relative to each other, wherein the determination assembly is movable, in particular rotatable determining at least one parameter of the energy beam (5) in the first spatial position guiding the energy beam (5) to a second spatial position positioning the beam guiding element (12) in a second determination position via a movement, in particular a rotation, of the irradiation assembly guiding the energy beam (5) to the determination unit (7) via the beam guiding element (12) positioned in the second determination position determining at least one parameter of the energy beam (5) in the second spatial position.

Description

[0045] Exemplary embodiments of the invention are described with reference to the FIG. The FIG. are schematic diagrams, wherein

[0046] FIG. 1 shows an inventive determination device in side view in a first determination position;

[0047] FIG. 2 shows a top view of the inventive determination device from FIG. 1; and

[0048] FIG. 3 shows the inventive determination device from FIG. 1 in side view in a second determination position.

[0049] FIG. 1 shows a determination device 1 that is arranged in a process chamber 2 of an apparatus 3 for additively manufacturing three-dimensional objects. The apparatus 3 comprises an irradiation device 4 that is adapted to generate an energy beam 5 and guide the energy beam 5 across a build plane 6, i.e. a plane in which build material is arranged to be irradiated in a regular mode of operation. Of course, the arrangement that is depicted in FIG. 1 is merely exemplary and any other arbitrary mode of arranging the determination device 1 in the process chamber 2 is also feasible. For example, it is not necessary that the additive manufacturing apparatus 3 comprises a height-adjustable carrying element, as depicted in FIG. 1.

[0050] The determination device 1 further comprises a determination unit 7 that is arranged centrally on a determination body 8, for example a metal plate. The determination body 8 can be moved via a moving unit 9, e.g. an actuator adapted to rotate the calibration body 8, as indicated via arrow 10, for example about a (vertical) rotation axis 11, e.g. a symmetry axis of the determination unit 7 and/or the determination body 8. The determination unit 7 is adapted to receive the energy beam 5 from a beam guiding element 12, as will be described below. The beam guiding element 12 and the determination unit 7 form a determination assembly, wherein the beam guiding element 12 and the determination unit 7 are arranged in a defined spatial arrangement, in particular in a defined relative position/orientation.

[0051] In other words, the determination unit 7 and the beam guiding element 12 are fixedly mounted to the determination body 8, wherein the beam guiding element 12 faces the determination unit 7, in particular a determination element 13 of the determination unit 7. It is also possible, for example with respect to multi laser systems or apparatuses with at least two irradiation units each adapted to guide an energy beam, that the moving unit 9 or a separate moving device (not shown) is adapted to move the determination assembly formed by the determination unit 7 and the beam guiding element 12, e.g. mounted to the determination body 8, between at least two different perpendicular incidence positions of two different irradiation units.

[0052] In the situation depicted in FIG. 1, the energy beam 5 is guided to the beam guiding element 12 which reflects the energy beam 5 to the determination unit 7, in particular to the determination element 13, such as an optical detector, preferably a PSD-sensor (camera). Therefore, the determination device 1 is adapted to determine the at least one parameter of the energy beam 5, such as an intensity of the energy beam 5 and/or an intensity distribution of the energy beam 5 and/or a geometry of the energy beam 5, in particular a spot shape and/or a spot size.

[0053] As described before with respect to FIG. 1, the determination unit 7 is depicted in a first determination position in which the energy beam 5 is guided to a first spatial position in which the energy beam 5 is incident on the beam guiding element 12 which is positioned in the first determination position. By rotating the determination assembly, i.e. the determination unit 7 (as indicated via arrow 10) and the beam guiding element 12, e.g. via a rotation of the determination body 8, the determination assembly can be moved between the different determination positions. Hence, if the at least one parameter of the energy beam 5 is to be determined in a different spatial position, the determination assembly can be rotated about the axis 11 to position the beam guiding element 12 in that spatial position in which the energy beam is incident on the beam guiding element 12 and can be guided to the determination unit 7, in particular to the determination element 13.

[0054] In FIG. 2, the determination position indicated in FIG. 1 is depicted in a top view, wherein a different determination position is indicated via a dashed contour. The dashed contour depicts a different determination position in which the determination assembly can be arranged, as indicated in FIG. 1 to determine the at least one parameter of the energy beam 5 incident in a different spatial position. To reach the situation that is depicted in FIG. 2, the determination unit 7 is rotated as indicated via arrow 10 clockwise (or counterclockwise) into the second determination position in which the determination element 13 of the determination unit 7 faces the second beam guiding element 14, as the entire determination assembly is rotated, e.g. via a rotational movement of the determination body 8. Hence, the energy beam 5 can be guided to the position of the determination body 8 in which the second beam guiding element 14 is arranged, wherein the beam guiding element 12 reflects the energy beam 5 towards the determination element 13 of the determination unit 7.

[0055] As can be derived from FIG. 2, the determination assembly can be rotated in various (arbitrary) determination positions in which the determination element 13 of the determination unit 7 can receive the energy beam 5 that is guided via the beam guiding element 12. Further, the two determination positions depicted in FIG. 2 are merely exemplary and any other arbitrary number or arrangement, in particular spatial arrangement of the determination assembly in the individual determination positions, is also feasible. FIG. 2 further shows that the determination unit 7 is arranged centrally on the determination body 8, e.g. centrally with respect to a movement path of the beam guiding element 12 with respect to a movement, in particular a rotation about the axis 11. In this exemplary embodiment, the movement path of the beam guiding element 12 is a circle.

[0056] FIG. 3 shows another side view of the determination device 1 in which the at least one parameter of the energy beam 5 has to be determined for a central position of the energy beam 5, e.g. a perpendicular beam path along which, for example, the energy beam 5 is guided from the irradiation device 4 perpendicular towards the build plane 6. Thus, the energy beam 5 in this FIG. is guided via the corresponding irradiation unit (not shown) of the irradiation device 4 to the perpendicular incidence position in which the energy beam is incident perpendicular in the build plane (in a regular mode of operation). Hence, in this central position/perpendicular incidence position the rotation axis 11 is in the same position as the optical axis along which the energy beam 5 propagates through the process chamber 2.

[0057] With the energy beam 5 being guided to the central position, the energy beam 5 is incident on a central beam guiding element 14 that is mounted above the beam guiding unit 7. In this exemplary embodiment the central beam guiding element 14 is mounted on an L-shaped frame 15 which is mounted to the determination body 8. In other words, the frame 15 and the central beam guiding element 14 rotate together with the determination assembly, i.e. the determination unit 7 and the beam guiding element 12, ensuring that the determination element 13 is always available for the energy beam 5 to be guided via the beam guiding element 12 and to be incident on the determination element 13. The energy beam 5 that is incident on the central beam guiding element 14 is first reflected to the beam guiding element 12. Hence, the energy beam 5 is reflected at the central beam guiding element 14 and the (other) beam guiding element 12 towards the determination element 13.

[0058] The beam guiding elements 12, 14 can be built as (off-axis) parabolic mirrors for collimating the energy beam 5 and guiding the energy beam 5 to the determination element 13. The energy beam 5 is typically focused to a focal position that lies in advance to the beam guiding element 12 (or 14), wherein the beam guiding element 12 being built as parabolic mirror collimates the energy beam 5 and guides the energy beam 5 to the determination element 13. The energy beam 5 incident on the beam guiding element 12 diverges and is collimated via the beam guiding element 12. Hence, it can be assured that the at least one parameter of the energy beam 5 can be determined properly independent of the position and the angle of incidence.

[0059] Self-evidently, all details, features and advantages described with respect to the individual embodiments can arbitrarily be combined or exchanged. Of course, the inventive method may be performed on the inventive apparatus 3, preferably using the inventive determination device 1.