WO2025219341A1

WO2025219341A1 - A measuring device for measuring a physical quantity in an additive manufacturing machine, and an additive manufacturing machine

Info

Publication number: WO2025219341A1
Application number: PCT/EP2025/060269
Authority: WO
Inventors: Manuel Pencelli; Marco Palladino; Andrea POLITANO; Giovanni De Magistris; Guido SCHILLACI; Luigi Bono BONACCHI; Marta FIORUCCI
Original assignee: Nuovo Pignone Technologie SRL
Current assignee: Nuovo Pignone Technologie SRL
Priority date: 2024-04-15
Filing date: 2025-04-14
Publication date: 2025-10-23
Anticipated expiration: 2026-10-15

Abstract

The measuring device includes a connection body, adapted to connect the device to a wall of the build chamber of the additive manufacturing machine. The measuring device further includes a robotic arm supported on the connection body. A probe is supported by the robotic arm and adapted to detect a physical quantity inside the build chamber. The robotic arm has at least a first degree of freedom and a second degree of freedom according to which the probe is movable; The first degree of freedom and second degree of freedom are rotational degrees of freedom 10 around a first rotation axis and a second rotation axis.

Description

A measuring device for measuring a physical quantity in an additive manufacturing machine, and an additive manufacturing machine

DESCRIPTION

TECHNICAL FIELD

[0001] The present disclosure relates generally to additive manufacturing, and more particularly to apparatus and methods for gas flow monitoring in additive manufacturing.

BACKGROUND ART

[0002] Additive manufacturing is a process in which material is built up layer-by- layer to form a component. Additive manufacturing is also referred to as “layered manufacturing,” “reverse machining,” “direct metal laser melting” (DMLM), and “3-D printing”.

[0003] One kind of additive manufacturing, particularly useful in manufacturing metallic components, is the so-called laser-based powder bed fusion of metals (PBF- LB/M) or laser powder bed fusion (L-PBF). These processes are also referred to as selective laser melting processes.

[0004] Additive manufacturing machines usually include a build chamber that encloses a mass of powder, typically a metal powder, which is selectively fused by energy generated by an energy source, such as a laser source. Selective fusion of sequentially formed powder layers generates the final workpiece. Specifically, powder is distributed layer-by layer and each layer is selectively fused and the fused metal powder is solidified to form a respective “slice” of the final work piece.

[0005] The build chamber is enclosed in a housing including side walls, a bottom wall and a ceiling wall. Usually, a shielding gas flow is generated by a gas inlet port arrangement. The shielding gas is used to transfer heat away from the surface of the power bed, to prevent vaporized powder from condensing on the surface of the workpiece, and to control undesired chemical reaction such as oxidation, for instance.

[0006] The shielding gas flow is of paramount importance in metal laser powder bed fusion as it removes spatters from the welding process as well as the plume consisting of metal condensate. Defects like porosity would result from these process byproducts, if they were not removed properly.

[0007] The shield gas flow rate shall be carefully controlled, since too a high or too a low flowrate are detrimental to the process. Shield gas flows having too high velocity can disturb the powder in the build chamber, disrupting the build process. Conversely, insufficient heat transfer and vapor removal would result in case of too low shield gas flow velocity. Insufficient heat and vapor removal leads to worse surface roughness in the finished workpiece.

[0008] Another issue with additive manufacturing machines is that the gas flow velocity varies over the surface of the build chamber. Specifically, the gas flow decelerates as it passes over the surface, because of normal pressure and friction losses. The velocity may also be inconsistent in a direction perpendicular to flow. Because of this variation, the gas flow rate may be acceptable in one location, but too high or low in another.

[0009] Systems have therefore been developed, aimed at measuring the shield gas flow rates and speeds in additive manufacturing machines. One such system is disclosed in WO2023179948. The additive manufacturing machine disclosed in this reference document includes a robot supporting a probe adapted to detect local speed or flowrate of the shield gas flow. To detect the local speed in various points of a volume where the workpiece is manufactured, the probe is moved by the robot according to three orthogonal translation axes i.e. three Cartesian axes. A complex and cumbersome arrangement of translation guides on a gantry structure is arranged in the build chamber for this purpose.

[0010] This known machine has some disadvantages. The structure of the robot is complex and comprises many components. The structure is expensive and interferes with the shield gas flow such as to alter the measurement of the gas flow.

[0011] In a further embodiment disclosed in WO2023179948 the probe is supported by an arm which is supported by a column that extends orthogonally from a bottom wall of the build chamber of the additive manufacturing machine. The arm has a rotational degree of freedom and the probe is adapted to slide along the arm. This latter is slidingly movable on the rotary column. The movements of the probe are slow and the structure has limitations as to the areas which can be reached by the probe.

[0012] A simpler device, with a less components and which does interfere, or interfere to a less extent with the shield gas flow, would therefore be welcomed in the art.

SUMMARY

[0013] According to one aspect, disclosed herein is a measuring device for measuring a physical quantity inside a build chamber of an additive manufacturing machine according to claim 1.

[0014] The measuring device comprises a connection body, adapted to connect the device to a wall of the build chamber of the additive manufacturing machine. The device further comprises a robotic arm supported on the connection body and a probe supported by the robotic arm and adapted to detect a speed or a flowrate of a stream of shield gas in the build chamber. The robotic arm has at least a first degree of freedom and a second degree of freedom according to which the probe is movable. Both said degrees of freedom are rotational degrees of freedom around respective first and second rotation axes.

[0015] In advantageous embodiments, the rotation axes are parallel to one another and orthogonal to the build platform of the additive manufacturing machine in which the measuring device is installed.

[0016] In this embodiment, the robotic arm can be a planar robotic arm, i.e. including pivoting arm sections which are coupled to one another and to a stationary structure such as to be movable about a plurality of axes which are all parallel to one another, and preferably orthogonal to the build platform of the additive manufacturing machine in which the measuring device is installed.

[0017] Embodiments including an anthropomorphic arm are not excluded, though more expensive and potentially more cumbersome. Such arms may have additional rotational degrees of freedom about axes which are not all parallel to one another. [0018] The resulting device has a simpler and more compact structure compared with devices of the prior art.

[0019] The robotic arm can have three sections, for instance a stationary section, attached to or forming part of the connection body, a first pivoting arm section and a second pivoting arm section. The first pivoting arm section can be hinged to the stationary arm section around the first rotation axis and the second pivoting arm section can be hinged to the first pivoting arm section around the second rotation axis. The use of more than two pivoting arm sections is not excuded.

[0020] The robotic arm and the connection body can be configured to be attached near the ceiling wall of the build chamber of the additive manufacturing machine, such that the mechanical components which support and move the probe do not interfere with the flow of shield gas. This can be achieved, for instance, with a connection body configured to be connected to the ceiling wall of the build chamber. Alternatively, the connection body can be configured for connection to a side wall or to a bottom wall and include a bracket, strut or column, which supports the robotic arm in a position adjacent the ceiling wall.

[0021] In alternative embodiments, it is also possible for the robotic arm to be positioned near the bottom wall or within a compartment housing the build platform of the additive manufacturing machine

[0022] An enhanced embodiment of the device includes a third degree of freedom, such that the probe can be moved according to three degrees of freedom.

[0023] In some embodiments, also the third degree of freedom is degree of rotational of freedom around a rotation axis. The third degree of freedom can envisage a rotation around a third rotation axis, which can be parallel to the first rotation axis and the second rotation axis.

[0024] For example, the probe can be attached to a stem, e.g., at the distal end of a stem, which extends from the robotic arm in a direction parallel to the rotation axes, or orthogonal to the plane, parallel to which the robotic arm moves.

[0025] The third degree of freedom can be a degree of rotational freedom involving rotation of the stem around the axis of the stem itself.

[0026] The third degree of freedom can be particularly beneficial if the probe is a directional probe, i.e. a probe adapted to measure e physical quantity which is characterized by a direction. For instance, the probe can be a probe adapted to measure the speed of the shield gas and which can also detect the direction of the shield gas flow. In other embodiments, the probe can be a simpler probe, which does not measure or detect a direction of the detected physical quantity. For instance, the probe can be adapted to only measure the module of the shield gas speed, or the temperature in a point of the volume inside the build chamber. In this case the third degree of freedom could be dispensed with.

[0027] In some embodiments, the third degree of freedom can be a degree of translation movement, for instance in a direction parallel to the first rotation axis. This degree of freedom allows the probe to be moved vertically and be placed at different heights above the build platform of the additive manufacturing machine.

[0028] A combination of a third degree of rotational movement and of a translational movement can be envisaged as well. In this case, the probe could be movable along a plane parallel to the build platform and further movable to take variable distances from the build platform, i.e can be movable in a plurality of horizontal planes. The degree of translation movement can be replaced by a simple possibility of manual or servoassisted adjustment of the distance between the probe and the robotic arm. This adjustment can for instance be achieved by lengthening or shortening a stem which supports the probe and departs from a distal end of the robotic arm.

[0029] The device can include further additional features adapted to increase the flexibility of use thereof, or the field in which measurements can be carried out therewith. For instance, one or more of the arm section of the robotic arm may have an adjustable length, to increase the operating range of the device or to adapt the device to build chambers of variable dimensions.

[0030] In some embodiments, the distance between the robotic arm, and specifically from the pivoting sections thereof, and the probe can be adjusted, such that measurements can be carried out at different heights inside the build chamber. [0031] These adjustments can be carried out manually, or a servo-actuator can be provided to perform one or both said length adjustments.

[0032] An adjustable arm section can be configured as a telescopic arm section, including two or more telescopic portions which can be shortened or lengthened. Similarly, an adjustable distance between the probe and the robotic arm can be obtained for instance using a probe supporting stem which is adapted to be telescopically lengthened or shortened.

[0033] According to a further aspect, disclosed herein is an additive manufacturing machine comprising: a build chamber; a build platform at a bottom of the build chamber; a shield gas supply system fluidly coupled to the build chamber and adapted to generate a shield gas flow in the build chamber at the build platform; an energy irradiating device configured to irradiate at least one portion of the build platform; a ceiling wall, a bottom wall, and side walls closing the build chamber; a measuring device as outlined above, attached to one of said walls.

[0034] Further features and embodiments of the measuring device and of an additive manufacturing machine containing the measuring device are described below and set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Reference is now made briefly to the accompanying drawings, in which:

Fig. l illustrates an axonometric view of an additive manufacturing machine, with the ceiling wall removed therefrom and a measuring device mounted therein;

Fig.2 illustrates a side view of the measuring device;

Fig.3 illustrates an axonometric view of the measuring device;

Fig.4 illustrates a sectional side view of the measuring device;

Fig.5 illustrates an axonometric view of the additive manufacturing machine, showing an energy source applied to the ceiling thereof; and

Fig. 6 illustrates a side view of a further embodiment of a measuring device according to the present disclosure DETAILED DESCRIPTION

[0036] Fig. l illustrates an additive manufacturing machine 1 with a measuring device 3 installed therein. The additive manufacturing machine 1 illustrated in Fig.l is by way of example only. Those skilled in the art will understand that the measuring device disclosed herein can be adapted to additive manufacturing machines having a different structure.

[0037] Referring to the exemplary embodiment of Fig.1, the additive manufacturing machine 1 comprises an additive manufacturing chamber, here below referred to as build chamber 5, closed by a bottom wall 7, side walls 9, a top wall or ceiling wall 11 (partly removed in Fig.l). The additive manufacturing machine 1 further comprises a build platform 13 positioned near or at the bottom wall 7. The build platform 13 coacts with an irradiating device S, schematically shown in Fig.5, which delivers energy, for example laser energy, to layers of powder material sequentially distributed on the build platform 13 or on an article of manufacture being built thereon (not shown).

[0038] The additive manufacturing machine 1 further comprises a shield gas supply system 17 fluidly coupled to the additive manufacturing chamber 5 and adapted to generate one or more shield gas flows in the build chamber 5. In the embodiment of Fig. l, the shield gas supply system is adapted to generate a primary flow at or immediately above the build platform 13 and a secondary flow at a distance of the build platform 13, for instance near the ceiling wall 11. In the illustrated embodiment the primary flow is generated by shield gas inlet ports 19 and shield gas outlet ports 21. The inlet ports 19 and the outlet ports 21 are opposite to one another and generate a generally horizontal shield gas flow, generally parallel to the build platform 13. Upper shield gas inlet ports 23 arranged at or near the ceiling wall generate a secondary shield gas flow

[0039] The measuring device 3 can be positioned inside the build chamber 5 to detect the speed of the shield gas in desired positions within the build chamber. The measuring device 3 is configured to displace a probe within a measuring volume inside the build chamber 5 and to have a minimum degree of interference with the shield gas flow, such that the measured values are as accurate as possible, i.e. as near as possible to the actual speed values during operation of the additive manufacturing machine 1, when the measuring device 3 is removed from the build chamber 5 or parked in a region thereof distant from the build platform 13 and from the shield gas flow.

[0040] In the embodiment of Figs. 1, 2 and 3 the measuring device 3 includes a connection body 31, wherewith the measuring device 3 is attached to a wall of the build chamber 5, in the exemplary embodiment of Fig.1 the ceiling wall.

[0041] The measuring device 3 further comprises a robotic arm 33 projecting from the connection body 31 and supported thereby. As will be described in more detail below, the robotic arm 33 has at last two degrees of freedom. In this embodiment, the robotic arm 33 has two rotational degrees of freedom, i.e. is movable around two rotation axes. In the exemplary embodiment the robotic arm 31 is a planar robotic arm, in the sense that the arm sections forming the robotic arm move in planes parallel to one another and parallel to the ceiling wall 5.

[0042] In other embodiments, the connection body 31 can be designed to be attached to a side wall of the additive manufacturing machine 1 and can be configured such that the robotic arm 33 is positioned near the ceiling wall in the same way as shown in Fig.1, for example using an L-shaped bracket or a similar coupling member.

[0043] In some embodiments, the robotic arm 33 comprises a first pivoting arm section 35, which is pivotally connected to the connection body 31. The first pivoting arm section 35 comprises a proximal end 35.1 hinged to the connection body 1 around a first rotation axis A-A. The first pivoting arm section 35 further comprises a distal end 35.2, which is hinged around a second rotation axis B-B, to a second pivoting arm section 37. In the illustrated embodiment the first rotation axis A-A and the second rotation axis B-B are parallel to one another and are orthogonal to the build platform 13.

[0044] The second pivoting arm section 37 comprises a proximal end 37.1, hinged around the second rotation axis B-B to the distal end 35.2 of the first pivoting arm section 35. With this arrangement, the first pivoting arm section 35 has a first rotational degree of freedom around the first rotation axis A-A and the second arm section 37 has a second rotational degree of freedom around the second axis B-B. The two pivoting arm sections 35 and 37 rotate in two respective planes which are parallel to one another and parallel to the build platform 13. Therefore, in this embodiment the robotic arm 33 is a planar robotic arm.

[0045] The second pivoting arm section 37 further comprises a distal end 37.2, which supports a probe 41. In the illustrated embodiment the probe is supported at the distal end 37.2 of the second pivoting arm section 37.

[0046] In the illustrated embodiment, the robotic arm 33 further comprises a stationary arm section 39 having a proximal end 39.1, rigidly coupled to the connection body 31, or forming part thereof, and a distal end 39.2, hinged to the first pivoting arm section 35 around the first rotation axis A-A.

[0047] In some embodiments, at least one of the stationary arm section 39, the first pivoting arm section 35, and second pivoting arm section 37 has an adjustable length. In the illustrated embodiment, the second pivoting arm section 37 has an adjustable length. The length of the adjustable arm section can be adjusted manually. In some embodiments, the adjustable arm section is telescopically adjustable and is comprised of two parts 37.3, 37.4 which are slidably engaged to one another. An actuator adapted to adjust the length of the adjustable arm section is not ruled out. By adjusting the length of the adjustable arm section, the measuring device 3 can be adapted to additive manufacturing machines 1 of different dimensions.

[0048] In some embodiments, the length adjustment can be servo-assisted, i.e. an actuator can be installed on the arm to adjust the length of the arms section.

[0049] In the illustrated embodiment, the probe 41 is supported at a distal end of a stem 43 constrained to the distal end 37.1 of the second pivoting arm section 37. The stem 43 can comprise two stem portions 43.1, 43.2 which are slidably engaged to one another such that the distance between the probe 41 and the second pivoting arm section 37 can be manually adjusted. In other embodiments, the stem 43 can be coupled to an actuator, which can be adapted to move the probe up and down, or to change the length thereof, thus adjusting the distance thereof with respect to the robotic arm 33.

[0050] In the illustrated embodiment, the stem 43 extends parallel to the rotation axes A-A and B-B and thus orthogonal to the plane along which the first and the second pivoting arm sections rotate. [0051] The rotation motion of the first pivoting arm section 35 around the first rotation axis A-A can be controlled by a first actuator 51, coupled to the connection body 31, or housed therein, and adapted to rotate the first pivoting arm section 35 around the first rotation axis A-A. The first actuator 51 can comprise an electronically controlled electric motor, for instance.

[0052] A first motion transmission member 53 can extend along the stationary arm section 39 from the first actuator 51 to the first pivoting arm section 35, and can be adapted to transmit a rotation motion from the first actuator 51 to the first pivoting arm section 35 around the first rotation axis A-A.

[0053] The robotic arm 33 can comprise a second actuator 55, supported at the distal end 39.2 of the stationary arm section 39, and adapted to rotate the second pivoting arm section 37 around the second rotation axis B-B. For instance, a second motion transmission member 59 inside the first pivoting arm section 35 can be provided, extending from the second actuator 55 to the second pivoting arm section 37, and adapted to transmit a rotation motion from the second actuator 55 to the second pivoting arm section 37 around the second rotation axis (B-B).

[0054] In some embodiments, the first and second motion transmission members 53 and 59 can comprise a respective belt entrained around pulleys, schematically shown at 52, 54 for belt 53 and at 56 and 58 for belt 59. The pulley 54 is rigidly coupled to the first pivoting arm section 35 and the pulley 58 is rigidly coupled to the second pivoting arm section 37.

[0055] The probe is adapted to measure a speed or a flowrate of a shield gas flow in the build chamber. To this end, the probe can comprise an anemometer or another probe adapted to detect the speed of the shield gas flow in the build chamber 5. In some embodiment, the probe 41 can be adapted to detect the absolute value of the gas speed. In other embodiments the probe 41 can be a directional probe, adapted to detect the speed value and the speed direction.

[0056] In some embodiments, the probe 41 can be adapted to rotate around a third rotation axis C-C, parallel to the rotation axes A-A and B-B. The rotation of the probe 41 around the third rotation axis C-C can be controlled by a dedicated actuator for instance an electronically controlled electric motor 42, which can be housed in, or supported by the second pivoting arm section 37, and can be coaxial to the stem 43

[0057] The described measuring device 3 can be positioned inside the build chamber 5 before commencing use of the additive manufacturing machine 1 in a production cycle. Its purpose is to characterize the velocity field of the shield gas. The rotational movement of the robotic arm 33 around the rotation axes A- A and B-B enables the probe 41 to be positioned in a plurality of points forming a detection grid or matrix. The shield gas velocity can be detected in each of said point. If the probe is a directional probe, by rotating the probe around axis C-C the direction of the flow can also be detected in each point.

[0058] If so required, measurements can be repeated at different heights above the build platform 13, thus obtaining measurement values according to a three-dimensional matrix of measuring points.

[0059] The measuring device 3 can be powered by an external electric power source, separate from the additive manufacturing machine 1. The movements around the first rotation axis A-A and the second rotation axis B-B can be programmed and controlled by an external control unit, which is functionally coupled to the actuators of the measuring device. This enables effortless execution of repetitive measurements with a high level of precision.

[0060] Since the robotic arm 33 is located close to the ceiling wall of the build chamber 5 and can move parallel to it, the measuring device 3 interferes minimally with the shield gas flow. Invasiveness is further reduced, considering that the probe is brought into the measuring position via a thin stem 43, while the supporting structure (robotic arm 33 and connection body 31) remains outside the volume affected by the shield gas flow.

[0061] The measurement device 33, including its control unit, not shown, forms a portable autonomous measuring system which can be installed in an additive manufacturing machine 1 when needed and then removed before starting the additive manufacturing process.

[0062] Fig.6 illustrates a side view, similar to Fig.2, of a further embodiment of a measuring device. The same reference numbers indicate the same or equivalent components already described in connection with the previously described figures. These components will not be described again in detail.

[0063] The measuring device 3 of Fig.6 comprises a connection body 31 for attaching to a wall of the build chamber, and a robotic arm 33, which includes a first pivoting arm section 35 and a second pivoting arm section 37. Similarly to the previously described embodiment, the first pivoting arm section 35 comprises a proximal end 35.1 hinged around a first rotation axis A-A to the connection body. The first pivoting arm section 35 further includes a distal end 35.2, which is hinged around a second rotation axis B-B, to the second pivoting arm section 37. In the illustrated embodiment the first rotation axis A-A and the second rotation axis B-B are parallel to one another and are orthogonal to the build platform 13. The distal end of the second pivoting arm section 37 is coupled to a stem 43, which supports, at the distal end thereof, a probe 41. The stem 43 can be coupled to the distal end 37.2 of the second arm section 37 by a bracket 42. The bracket 42 can be hinged around a third rotation axis C-C, which is parallel to the rotation axes A-A an B-B. Reference D-D designate the axis of the stem 43, which is parallel to the axes A-A, B-B and C-C. In other embodiments, the stem 43 can be supported directly at the distal end 37.2 of the second arm section 37. The stem 43 can be telescopically extendable, or can be vertically movable parallel to axis D-D, to position the probe 41 at a required distance from the build platform 13. U

[0064] The embodiment of Fig. 6 differs from the embodiment of Figs. 2-4 in that the second arm section 37 is positioned under the first arm section 35. This enables the probe 41 to move without restrictions along the entire are covered by the rotation of the robotic arm around axes A-A and B-B.

[0065] While in the above description reference is specifically made to a gas speed probe, in other embodiments a different physical entity can be measured inside the build chamber 5 using a different kind of probe mounted on the stem. For instance, the device can be used to detect a gas temperature or a local gas flowrate. In yet further embodiments, the probe can be adapted to detect the temperature of the build platform 13.

[0066] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the scope of the invention as defined in the following claims.

Claims

1. A measuring device for measuring a physical quantity inside a build chamber of an additive manufacturing machine, the device comprising: a connection body, adapted to connect the device to a wall of the build chamber of the additive manufacturing machine; a robotic arm supported on the connection body; a probe supported by the robotic arm and adapted to detect a local speed or flowrate of a shield gas flow inside the build chamber; wherein the robotic arm comprises: a first pivoting arm section comprising a proximal end and a distal end; wherein the proximal end is hinged to the connection body around a first rotation axis defining a first degree of freedom according to which the probe is movable by the robotic arm; and a second pivoting arm section, comprising a proximal end and a distal end; wherein the proximal end of the second pivoting arm section is hinged to the distal end of the first pivoting arm section around a second rotation axis defining a second degree of freedom according to which the probe is movable by the robotic arm.

2. The device of claim 1, wherein the first rotation axis and the second rotation axis are parallel to one another; and wherein the probe is supported at the distal end of the second pivoting arm section

3. The device of claim 2, wherein the first rotation axis and the second rotation axis are orthogonal to the build platform and the first pivoting arm section and the second pivoting arm section move parallel to the build platform.

4. The device of any one of the preceding claims, wherein the robotic arm has a third degree of freedom.

5. The device of claim 4, wherein the third degree of freedom is a rotational degree of freedom around a third rotation axis, preferably parallel to the first rotation axis and/or to the second rotation axis.

6. The device of any one of the preceding claims, wherein the probe is supported by a stem extending orthogonally to a plane parallel to which the robotic arm moves, the plane being orthogonal to the first rotation axis and to the second rotation axis.

7. The device of claim 6, wherein the stem extends from the robotic arm to a distal end of the stem; and wherein the probe is connected to the distal end of the stem.

8. The device of claim 7, wherein a distance of the distal end of the stem from the robotic arm is adjustable in a direction parallel to the first rotation axis and to the second rotation axis; and wherein said distance is adjustable manually or with the aid of an actuator adapted to rotate the stem around a rotation axis parallel to the first rotation axis.

9. The device of any one of claims 6 to 8, wherein the stem is provided with a degree of rotational freedom around a third rotation axis, which is parallel to the first rotation axis, to the second rotation axis and to the stem.

10. The device of claim any preceding claim, wherein the robotic arm comprises a stationary arm section having a proximal end, rigidly coupled to the connection body, and a distal end, hinged to the first pivoting arm section around the first rotation axis,

11. The device of any preceding claim, wherein at least one of said stationary arm section, first pivoting arm section, and second pivoting arm section has an adjustable length; and wherein the length can be adjusted manually or through an actuator.

12. The device according to any preceding claim, further comprising a first actuator, coupled to the connection body and adapted to rotate the first pivoting arm section around the first rotation axis.

13. The device of claim 12, comprising a first motion transmission member extending inside or along the stationary arm section from the first actuator to the first pivoting arm section, and adapted to transmit a rotation motion around the first rotation axis, from the first actuator to the first pivoting arm section.

14. The device of claim 12 or 13, comprising a second actuator, supported by the first pivoting arm section and adapted to rotate the second pivoting arm section around the second rotation axis.

15. The device of claim 14, comprising a second motion transmission member extending inside or along the first pivoting arm section, from the second actuator to the second pivoting arm section and adapted to transmit a rotation motion around the second rotation axis, from the second actuator to the second pivoting arm section.

16. The device of any preceding claim, wherein the probe is adapted to detect a direction of the speed of the shield gas flow.

17. An additive manufacturing machine comprising: a build chamber; a build platform at a bottom of the build chamber; a shield gas supply system fluidly coupled to the build chamber and adapted to generate a shield gas flow in the build chamber at the build platform; an energy irradiating device configured to irradiate at least one portion of the build platform; a ceiling wall, a bottom wall, and side walls closing the build chamber; a measuring device according to any one of the preceding claims attached to one of said walls.

18. The additive manufacturing machine of claim 17, wherein measuring device is coupled to the wall of the build chamber such that the robotic arm of the measuring device is positioned above the build platform and moves parallel to the build platform, and the probe extends from the robotic arm downwards towards the build platform.

19. The additive manufacturing machine of claim 17 or 18, wherein the connection body of the measuring device is coupled to the ceiling wall of the build chamber; and wherein the robot arm is movable parallel to the ceiling wall, above the building platform.