ADDITIVE MANUFACTURING MACHINE WITH A LOW-VOLUME SPEAKER

Abstract

The invention relates to an additive manufacturing machine comprising: - a build chamber (10) including a build platform, a front wall, a rear wall, and two side walls, right and left (PLD, PLG), - a selective consolidation source (22) emitting a selective consolidation beam, - a gas flow circulation volume (V1), and - a gas flow diffuser (26) and a gas flow collector (28) located on either side of a gas flow circulation volume. According to the invention, the right (PLD) and left (PLG) side walls are constituted by a diffuser (26) and / or a collector (28), and these right (PLD) and left (PLG) side walls correspond geometrically to the outer limits of the displacement volume of the selective consolidation beam to reach any point on the upper surface of the build platform. Abstract figure: Figure 2

Description

Title of the invention: ADDITIVE MANUFACTURING MACHINE WITH A REDUCED VOLUME ENCLOSURE

[0001] The present invention relates to the evacuation of metal fumes and vapors in an additive manufacturing enclosure by powder bed deposition and selective melting of the powder.

[0002] The metallic fumes and vapors generated by the selective melting of the powder can present various disadvantages if they are not evacuated correctly.

[0003] On the one hand, these metal fumes and vapors can pollute the window(s) through which one or more laser beams enter the manufacturing enclosure. These metal fumes and vapors can also pollute the walls of the enclosure and their equipment (sensors, measuring instruments, observation window, etc.).

[0004] On the other hand, these metallic fumes and vapors can pollute the powder used to manufacture objects in the manufacturing enclosure and therefore modify the chemical composition of the material from which these objects will be manufactured.

[0005] Finally, the metal fumes and vapors generated in a first zone of a powder layer can degrade the quality of the melt in a second zone of this powder layer if they are crossed by the laser beam carrying out the selective melting of the powder in this second zone.

[0006] Application US2019 / 0262901 is known in which two gas flows are used to evacuate metal fumes and vapors inside an additive manufacturing enclosure. A first gas flow circulates in the upper part of the manufacturing enclosure and a second gas flow circulates as close as possible to the powder layer in a laminar manner. The first gas flow enters the manufacturing enclosure via an inlet formed by a porous wall occupying almost the entire wall of the manufacturing enclosure. The second gas flow enters the manufacturing enclosure via a slot-shaped inlet which is located under the porous wall forming the first gas inlet. A slot-shaped outlet is provided in the wall opposite the wall receiving the gas inlets for evacuating the gas flows laden with metal fumes and vapors. Alternatively, this outlet can occupy the entire wall where it is located.

[0007] Document US2019 / 0262901 does not specify what form the gas flow outlet takes when this outlet occupies the entire wall where it is located, whereas this air outlet cannot take the form of a slot occupying the entire surface of this wall. From document US2019 / 0262901, it could be imagined to provide an outlet in the form of a fully porous wall. However, this solution would not be not viable because the pores of the porous wall would quickly become clogged by smoke particles and metal vapor deposits.

[0008] The present invention provides a complete and detailed arrangement of a manufacturing enclosure of an additive manufacturing machine in which one or more laminar gas flows enter(s) the enclosure and exit(s) the enclosure through one or more diffusers and one or more collectors which extend over almost the entire height of the manufacturing enclosure, as well as over the entire width of this enclosure.

[0009] Another objective of the invention is to reduce the time required to fill an additive manufacturing enclosure with an inert gas, particularly when it is a large additive manufacturing machine with a manufacturing enclosure having a large volume, of several cubic meters to give an idea.

[0010] A main objective of the invention is to reduce pollution by fumes and metal vapors inside the manufacturing enclosure by eliminating the volumes of the manufacturing enclosure which are not sufficiently swept by the fume evacuation flow(s) and in which these fumes and metal vapors can stagnate.

[0011] To this end, the invention relates to an additive manufacturing machine by powder bed deposition comprising: - a manufacturing enclosure comprising a work surface and a manufacturing tray capable of receiving a layer of powder, as well as a front wall, a rear wall and two right and left side walls, - at least one powder distribution device for distributing powder inside the manufacturing enclosure, - at least one device for producing a layer of powder enabling a layer of powder to be produced above the manufacturing plate, - at least one source for selective consolidation of a layer of powder by total or partial fusion emitting at least one selective consolidation beam, this selective consolidation source being located outside the manufacturing enclosure and emitting at least one selective consolidation beam which enters the manufacturing enclosure via a window, - at least one circulation volume of a gas flow located inside the manufacturing enclosure, and - a diffuser of a gas flow and a collector of a gas flow located on either side of a circulation volume of a gas flow.

[0012] According to the invention, the right and left side walls of the manufacturing enclosure are constituted by a diffuser and / or a collector, and these right and left side walls correspond geometrically to the outer limits of the displacement volume of the selective consolidation beam(s) traveling through the volume(s) of circulation of a gas flow to reach any point on the upper surface of the build plate.

[0013] Thanks to this configuration, the overall volume of the manufacturing enclosure is reduced and therefore easier to fill with an inert gas. In addition, this configuration makes it possible to eliminate the volumes of the manufacturing enclosure which are not sufficiently swept by the smoke evacuation flow(s) and in which these smoke and metal vapors can stagnate.

[0014] Advantageously, but not necessarily, the invention may also provide that: - the right and left side walls of the manufacturing enclosure are inclined towards each other so that the distance between these side walls decreases as one moves away from the manufacturing platform and gets closer to the selective consolidation source(s), - the right and left side walls of the manufacturing enclosure are inclined at an angle of no more than 20° relative to a vertical plane, - the front and rear walls of the manufacturing enclosure geometrically correspond to the outer limits of the displacement volume of the selective consolidation beam(s) traveling through the circulation volume(s) of a gas flow to reach any point on the upper surface of the manufacturing plate, - the front and rear walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° maximum relative to a vertical plane, so that the distance between these front and rear walls decreases as one moves away from the manufacturing platform and approaches the source(s) of selective consolidation, - the front and rear walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° maximum relative to a vertical plane, so that the distance between these front and rear walls increases as one moves away from the manufacturing platform and approaches the source(s) of selective consolidation, - the manufacturing enclosure and the circulation volume(s) of a gas flow extend in height over the entire distance separating the selective consolidation source(s) from the manufacturing platform, - the manufacturing enclosure and the circulation volume(s) of a gas flow extend in height only over part of the distance separating the selective consolidation source(s) from the manufacturing platform, - the manufacturing enclosure and the circulation volume(s) of a gas flow extend in height over less than half the distance separating the selective consolidation source(s) from the manufacturing platform, - the manufacturing enclosure comprises at least one housing for receiving the device for producing a layer of powder, and possibly the powder distribution device, this receiving housing being equipped with a closing flap, - a receiving housing is provided in the front wall and / or in the rear wall of the manufacturing enclosure, - a receiving housing comprises an evacuation for the powder deposited in excess and entrained inside the receiving housing by the device for producing a layer of powder, - a diffuser is a porous wall or a wall comprising a plurality of openings in the form of slots and / or orifices distributed over the entire surface of this wall, and in which a collector is a wall comprising a plurality of openings in the form of slots and / or orifices distributed over the entire surface of this wall, - a collector and a diffuser extend over at least 90% of the height of the manufacturing enclosure and the circulation volume(s) of a gas flow, - the device for producing a layer of powder is mounted on translational guidance and drive means, and in which these translational guidance and drive means are housed in clearances provided in the work surface and on either side of the manufacturing plate, - the clearances include a protective strip for the translational guidance and drive means.

[0015] Still according to the invention, the manufacturing enclosure comprises a single volume for circulating a gas flow and a plurality of selective consolidation sources, or at least two volumes for circulating a gas flow juxtaposed between the right and left side walls of the manufacturing enclosure and a plurality of selective consolidation sources aligned above each volume for circulating a gas flow.

[0016] In the case where the manufacturing enclosure comprises two juxtaposed gas flow circulation volumes, each gas flow circulation volume is located between a diffuser and a collector dedicated to this gas flow circulation volume, a collector / collector assembly or a diffuser / diffuser assembly being interposed between the two gas flow circulation volumes.

[0017] Other characteristics and advantages of the invention will appear in the description which follows. This description, given by way of example and not as a limitation, refers to the attached drawings in which: - [Fig.l] schematically illustrates a cross-sectional view of an additive manufacturing machine according to the invention, with a first embodiment of a manufacturing enclosure according to the invention, - [Fig.2] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a first embodiment of a manufacturing enclosure according to the invention, - [Fig.3] schematically illustrates a cross-sectional view of an additive manufacturing machine according to the invention, with a second embodiment of a manufacturing enclosure according to the invention, - [Fig.4] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a second embodiment of a manufacturing enclosure according to the invention, - [Fig.5] schematically illustrates a cross-sectional view of an additive manufacturing machine according to the invention, with a third embodiment of a manufacturing enclosure according to the invention, - [Fig.6] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a third embodiment of a manufacturing enclosure according to the invention, - [Fig.7] schematically illustrates a cross-sectional view of an additive manufacturing machine according to the invention, with a fourth embodiment of a manufacturing enclosure according to the invention, - [Fig.8] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a fourth embodiment of a manufacturing enclosure according to the invention, - [Fig.9] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a fifth embodiment of a manufacturing enclosure according to the invention, - [Fig. 10] schematically illustrates a longitudinal sectional view of an additive manufacturing machine according to the invention, with a sixth embodiment of a manufacturing enclosure according to the invention.

[0018] The invention relates to the evacuation of fumes and other particles created by the implementation of an additive manufacturing process by fusion inside a manufacturing enclosure of an additive manufacturing machine.

[0019] More specifically, the invention relates to additive manufacturing by deposition of powder layers and selective consolidation by total or partial selective fusion of these powder layers.

[0020] In the context of the invention, an additive manufacturing powder is preferably metallic, but it can also be non-metallic.

[0021] A manufacturing enclosure 10 of an additive manufacturing machine by powder bed deposition according to the invention is schematically illustrated by FIGS. 1 and 2. For example, this manufacturing enclosure is sealed and filled with an inert gas, in particular with a view to preventing oxidation of the powder grains or the start of fires.

[0022] The manufacturing enclosure 10 comprises a front wall PAV, a rear wall PAR and two right side walls PLD and left PLG. Preferably, the front PAV, rear PAR and right side walls PLD and left PLG are flat walls. Between these different walls, the manufacturing enclosure 10 comprises a work surface 12 and a manufacturing plate 14 capable of receiving a layer of powder. Preferably, the work surface 12 and the manufacturing plate 14 are flat and horizontal. For example, the manufacturing enclosure 10 rises above the work surface 12. For example, the work surface 12 forms the floor of the manufacturing enclosure. A manufacturing jacket 16 is located under the work surface 12 and opens into this work surface through an opening provided in this work surface. For example, the manufacturing plate 14 moves inside the manufacturing jacket 16 under the effect of an actuator (not shown) and makes it possible to receive the layers of powder one after the other.

[0023] For the production of the powder layers, the additive manufacturing machine comprises a powder distribution device 18 for distributing powder inside the manufacturing enclosure and a device 20 for producing a powder layer for producing a powder layer above the manufacturing plate 14. This distribution device 18 makes it possible, for example, to distribute a bead of powder on the work surface 12 between the device 20 for producing a powder layer and the manufacturing plate 14.

[0024] For example, the powder distribution device 18 takes the form of two powder reservoirs mounted on the device 20 for producing a layer of powder, one reservoir mounted at the front of the production device 20 and one reservoir mounted at the rear of the production device 20. For example, the two reservoirs are mounted to move in translation on the production device 20 along its longitudinal axis.

[0025] For example, a device 20 for producing a layer of powder takes the form of a carriage supporting at least one roller, one blade, and / or one scraper. The roller, the blade, and / or the scraper is / are of a shape and material suitable for spreading the powder used. For example, the device 20 for producing a layer of powder moves horizontally in translation above the manufacturing plate 14 and the work surface 12. For example, the device 20 for producing a layer of powder moves in translation across the width of the manufacturing enclosure 10, between the front PAV and rear PAR walls of this manufacturing enclosure.

[0026] For the implementation of additive manufacturing, the machine comprises at least one source 22 for selective consolidation of a layer of powder by total or partial fusion emitting at least one beam F of selective consolidation. Preferably, a selective consolidation source is located outside the manufacturing enclosure and emits at least one beam F of selective consolidation which penetrates into the manufacturing enclosure via a window 24. Preferably, the additive manufacturing machine according to the invention comprises a large work plate, of more than 35 centigrade. meters long and / or more than 35 centimeters wide, the additive manufacturing machine comprises several selective consolidation sources 22. For example, the additive manufacturing machine comprises several selective consolidation sources in the width of the manufacturing enclosure, i.e. between its front PAV and rear PAR walls, and / or several selective consolidation sources in the length of the manufacturing enclosure, i.e. between its left PLG and right PLD side walls. For example, a selective consolidation source 22 is a laser source emitting a laser beam F and comprising means, such as two mirrors for example, for moving this laser beam inside the manufacturing enclosure and for managing the focusing of the laser beam, in particular as a function of the position of the spot created by the laser beam on the layer of powder present above the manufacturing plate.

[0027] GENERATION OF THE GAS FLOW(S)

[0028] For the evacuation of the fumes generated by the selective consolidation by fusion, the machine comprises at least one circulation volume VI of a gas flow F1 located inside the manufacturing enclosure. A diffuser 26 of a gas flow and a collector 28 of a gas flow are located on either side of a circulation volume of a gas flow. A circulation volume of a gas flow VI and the diffuser 26 and the collector 28 associated with this circulation volume are part of the same circulation circuit of a gas flow. For this purpose, a diffuser 26 and a collector 28 which are located on either side of the same circulation volume of a gas flow are connected by a ventilation duct 30. This ventilation duct 30 is located outside the manufacturing enclosure 10.Preferably, a gas flow circulation circuit comprising a circulation volume VI of a gas flow F1, a diffuser 26, a collector 28 and a ventilation duct 30 also comprises a device 32 for generating the gas flow, such as a pump, and a filtration device (not shown) for separating the gas extracted from the manufacturing enclosure from the smoke particles collected in the manufacturing enclosure. Thus, a gas flow circulation circuit forms a closed circuit with the gas flow circulation volume with which it is associated. In other words, a gas flow circulation circuit makes it possible to reintroduce into the manufacturing enclosure the gas previously extracted from the manufacturing enclosure. Advantageously, a gas flow circulation circuit may also comprise a device for cooling the gases collected in the manufacturing enclosure.Preferably, a gas flow used for the evacuation of fumes in the manufacturing enclosure is laminar.

[0029] REDUCED VOLUME SPEAKER

[0030] According to the invention and in order to optimize the evacuation of fumes and to reduce the time taken to fill the manufacturing enclosure with an inert gas, the side walls right PLD and left PLG side walls of the manufacturing enclosure 10 are constituted by a diffuser 26 and / or a collector 28, and these right PLD and left PLG side walls geometrically correspond to the outer limits of the displacement volume of the selective consolidation beam(s) F traveling through the circulation volume(s) VI of a gas flow to reach any point on the upper surface of the manufacturing plate. More precisely, the right PLD and left PLG side walls of the manufacturing enclosure 10 are constituted by the front face F26 of a diffuser 26 and / or by the front face F28 of a collector 28. Preferably, the front faces of a diffuser and a collector, and therefore the right PLD and left PLG side walls of the manufacturing enclosure 10, are planar.

[0031] Generally, the walls of the manufacturing enclosure are geometrically defined by the paths of the selective consolidation beam(s) used to melt the powder. Thus, the volume of the manufacturing enclosure is limited to the only volume useful for the movement(s) of the selective consolidation beam(s) in this manufacturing enclosure.

[0032] In the present invention, the right PLD and left PLG side walls of the manufacturing enclosure are inclined towards each other so that the distance between these side walls decreases as one moves away from the manufacturing plate 14 and approaches the selective consolidation source(s) 22. Preferably, the right PLD and left PLG side walls of the manufacturing enclosure are inclined at an angle of 20° at most relative to a vertical plane. This limit of 20° corresponds to the maximum angle of inclination that a selective consolidation beam F can take inside the manufacturing enclosure to guarantee optimal consolidation of the powder.

[0033] Still in the present invention, the front PAV and rear PAR walls of the manufacturing enclosure also geometrically correspond to the outer limits of the displacement volume of the selective consolidation beam(s) traveling through the circulation volume(s) of a gas flow to reach any point on the upper surface of the manufacturing plate.

[0034] FIRST EMBODIMENT

[0035] In a first embodiment of the manufacturing enclosure illustrated by figures 1 and 2, the front PAV and rear PAR walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls decreases as one moves away from the manufacturing plate 14 and approaches the selective consolidation source(s) 22.

[0036] In this first embodiment of the manufacturing enclosure, the manufacturing enclosure 10 comprises a single circulation volume VI of a gas flow located between a diffuser 26 forming the left side wall PLG of the manufacturing enclosure and a collector 28 forming the right side wall PLD of the manufacturing enclosure.

[0037] In this first embodiment of the manufacturing enclosure, the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height over the entire distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14.

[0038] SECOND EMBODIMENT

[0039] In a second embodiment of the manufacturing enclosure illustrated by figures 3 and 4, the front PAV and rear PAR walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls decreases as one moves away from the manufacturing plate 14 and approaches the selective consolidation source(s) 22.

[0040] In this second embodiment of the manufacturing enclosure, the manufacturing enclosure 10 comprises a single circulation volume VI of a gas flow located between a diffuser 26 forming the left side wall PLG of the manufacturing enclosure and a collector 28 forming the right side wall PLD of the manufacturing enclosure.

[0041] In this second embodiment of the manufacturing enclosure, the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height only over a portion of the distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14. For example, the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height over less than half of the distance D separating the selective consolidation source(s) from the manufacturing plate. Thanks to this reduction in height of the manufacturing enclosure and the circulation volume of the gas flow, the gas flow F1 must cover a less significant height and it is easier to obtain and maintain the laminarity of this gas flow.

[0042] In this second embodiment of the manufacturing enclosure, and generally in this invention, when the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height only over a portion of the distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14, the window 24 through which the selective consolidation beam(s) enter the manufacturing enclosure is distant from the selective consolidation source(s) 22. In addition, this window 24 acts as the ceiling of the manufacturing enclosure.

[0043] In the first and second embodiments of the manufacturing enclosure, the manufacturing machine comprises four selective consolidation sources 22 arranged in two rows across the width and length of the manufacturing enclosure.

[0044] THIRD EMBODIMENT

[0045] In a third embodiment of the manufacturing enclosure 10 illustrated by figures 5 and 6, the front PAV and rear PAR walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls increases as one moves away from the manufacturing plate and approaches the selective consolidation source(s).

[0046] This reverse inclination of the front and rear walls of the manufacturing enclosure makes it possible to have a greater number of selective consolidation sources within the width of the manufacturing enclosure, six selective consolidation sources in the example illustrated in [Fig.5].

[0047] In this third embodiment of the manufacturing enclosure, the additive manufacturing machine comprises, for example, two rows of six selective consolidation sources.

[0048] In this third embodiment of the manufacturing enclosure, the manufacturing enclosure 10 comprises a single circulation volume VI of a gas flow located between a diffuser 26 forming the left side wall PLG of the manufacturing enclosure and a collector 28 forming the right side wall PLD of the manufacturing enclosure.

[0049] In this third embodiment of the manufacturing enclosure, the manufacturing enclosure and the circulation volume VI of a gas flow extend in height over the entire distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14.

[0050] FOURTH EMBODIMENT

[0051] In a fourth embodiment of the manufacturing enclosure 10 illustrated by figures 7 and 8, the front PAV and rear PAR walls of the manufacturing enclosure are also inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls increases as one moves away from the manufacturing plate 14 and approaches the selective consolidation source(s) 22.

[0052] This reverse inclination of the front and rear walls of the manufacturing enclosure makes it possible to have a greater number of selective consolidation sources within the width of the manufacturing enclosure, six selective consolidation sources in the example illustrated in [Fig.7].

[0053] In this fourth embodiment of the manufacturing enclosure, the additive manufacturing machine comprises, for example, two rows of six selective consolidation sources.

[0054] In this fourth embodiment of the manufacturing enclosure, the manufacturing enclosure 10 comprises a single circulation volume VI of a gas flow located between a diffuser 26 forming the left side wall PLG of the manufacturing enclosure and a collector 28 forming the right side wall PLD of the manufacturing enclosure.

[0055] In this fourth embodiment of the manufacturing enclosure, the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height only over a portion of the distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14. For example, the manufacturing enclosure 10 and the circulation volume VI of a gas flow extend in height over less than half of the distance D separating the selective consolidation source(s) from the manufacturing plate. Thanks to this reduction in height of the manufacturing enclosure and the circulation volume of the gas flow, the gas flow F1 must cover a less significant height and it is easier to obtain and maintain the laminarity of this gas flow.

[0056] In this fourth embodiment of the manufacturing enclosure, the window 24 through which the selective consolidation beams enter the manufacturing enclosure is remote from the selective consolidation sources 22. In addition, this window 24 acts as the ceiling of the manufacturing enclosure.

[0057] In the first four embodiments of the manufacturing enclosure which have just been described, the manufacturing enclosure 10 comprises a single circulation volume VI of a gas flow F1 and a plurality of selective consolidation sources 22.

[0058] FIFTH AND SIXTH EMBODIMENT

[0059] In a fifth and a sixth embodiment of the manufacturing enclosure illustrated by figures 9 and 10, the manufacturing enclosure comprises two circulation volumes VI,V2 of a gas flow Fl,F2 juxtaposed between the right PLD and left PLG side walls of the manufacturing enclosure, and a plurality of selective consolidation sources 22 aligned above each circulation volume of a gas flow.

[0060] In this fifth and sixth embodiment of the manufacturing enclosure, six selective consolidation sources 22 are for example aligned above each circulation volume VI, V2. Also, the front and rear walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls increases as one moves away from the manufacturing plate 14 and approaches the selective consolidation source(s) 22.

[0061] In this fifth and sixth embodiment of the manufacturing enclosure, each circulation volume VI,V2 of a gas flow is located between a diffuser 26 and a collector 28 dedicated to this circulation volume of a gas flow.

[0062] In the fifth embodiment of the manufacturing enclosure 10 illustrated in [Fig.9], the two gas flows F1, F2 circulating in the two circulation volumes of a gas flows VI,V2 are convergent. In more detail, the two gas flows F1,F2 are directed towards the center of the manufacturing enclosure. For this purpose, the left PLG and right PLD side walls of the manufacturing enclosure take the form of diffusers 28, and a collector / collector assembly 34 is interposed between the two circulation volumes VI,V2 of a gas flow. This collector / collector assembly 34 extends from the ceiling of the manufacturing enclosure towards the manufacturing plate 14, but its lower end 36 is located a few centimeters above the work surface 12 and the manufacturing plate 14 when the latter is in its initial position at the start of manufacturing. For example, the lower end 36 of the collector / collector assembly 34 is located three or four centimeters above the work surface 12 and the manufacturing plate 14 in its initial position at the start of manufacturing.Thus, the device 18 for producing a layer of powder can pass under the collector / collector assembly and an overlapping zone between the selective consolidation beams operating in the different circulation volumes of a gas flow is created under the collector / collector assembly.

[0063] In the sixth embodiment of the manufacturing enclosure 10 illustrated in [Fig. 10], the two gas flows F1, F2 circulating in the two circulation volumes of a gas flow VI, V2 are divergent. In more detail, the two gas flows F1, F2 are directed towards the right PDL and left PLG side walls of the manufacturing enclosure. For this purpose, the left PLG and right PLD side walls of the manufacturing enclosure take the form of collectors 28, and a diffuser / diffuser assembly 38 is interposed between the two circulation volumes VI, V2 of a gas flow. This diffuser / diffuser assembly 38 extends from the ceiling of the manufacturing enclosure towards the manufacturing plate 14, but its lower end 40 is located a few centimeters above the work surface 12 and the manufacturing plate 14 when the latter is in its initial position at the start of manufacturing.For example, the lower end 40 of the diffuser / diffuser assembly 38 is located three or four centimeters above the work plane 12 and the manufacturing plate 14 in its initial position at the start of manufacturing. Thus, the device 18 for producing a layer of powder can pass under the diffuser / diffuser assembly and an overlapping zone between the selective consolidation beams operating in the different circulation volumes of a gas flow is created under the diffuser / diffuser assembly.

[0064] Alternatively, in this fifth and sixth embodiment of the manufacturing enclosure, a collector / collector assembly 34 or a diffuser / diffuser assembly 38 may extend lower, as close as possible to the layer of powder to be fused and the work surface 12. In this case, a collector / collector assembly or a diffuser / diffuser assembly is mounted to move vertically in translation. Thus, a collector / collector assembly or a diffuser / diffuser assembly may be moved into position high to allow the passage of the device for producing a layer of powder and moved to the low position, as close as possible to the layer of powder, during the selective melting of the layer of powder carried out by the selective consolidation beams.

[0065] In this fifth and sixth embodiment of the manufacturing enclosure 10, the manufacturing enclosure 10 and the circulation volumes VI,V2 of a gas flow extend in height over the entire distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14.However, the invention also covers embodiments of the manufacturing enclosure in which the manufacturing enclosure comprises several volumes for circulating a gas flow juxtaposed between its right PLD and left PLG side walls, with a plurality of selective consolidation sources 22 aligned above each volume for circulating a gas flow, and in which the manufacturing enclosure 10 and the volumes for circulating a gas flow extend in height only over a portion of the distance D separating the selective consolidation source(s) 22 from the manufacturing plate 14.

[0066] The present invention also covers embodiments of the invention in which the manufacturing enclosure comprises more than two circulation volumes of a gas flow, such as for example three or four circulation volumes of a gas flow juxtaposed between the right and left side walls of the manufacturing enclosure, i.e. in the length of the manufacturing enclosure. In such a case, it is preferable to avoid the gas flows of two circulation volumes of a gas flow arranged next to each other heading in the same direction.

[0067] OTHER COMMON FEATURES

[0068] The characteristics described below are present in the additive manufacturing machine, regardless of the embodiment of its manufacturing enclosure 10.

[0069] In order to avoid disturbing the laminar flow of the gas flow(s) F1, F2 inside the manufacturing enclosure, the manufacturing enclosure 10 comprises at least one receiving housing 42 for the device 20 for producing a layer of powder. In the case where the powder distribution device 18 is mounted on the device 20 for producing a layer of powder, the receiving housing 42 also makes it possible to receive the powder distribution device 18. Still in order to avoid disturbing the laminar flow of the gas flow(s) F1, F2 inside the manufacturing enclosure, a receiving housing 42 is equipped with a closing flap 44.This closing flap 44 can take a closed position in which it forms a wall between the receiving housing and the circulation volume(s) of a gas flow, and an open position in which it frees access to the receiving housing for the device 20 for producing a layer of powder, and the powder distribution device 18 if applicable. Such a receiving housing 42 is preferably provided in the front wall PAV and / or in the rear wall PAR of the manufacturing enclosure. Preferably, to avoid unnecessary return trips of the device 20 for producing a layer of powder above the manufacturing plate 14, a receiving housing 42 is provided in the front wall PAV of the manufacturing enclosure and a receiving housing 42 is provided in the rear wall PAR of the manufacturing enclosure. A receiving housing 42 is part of the manufacturing enclosure 10, and it is preferably filled with the same inert gas as the manufacturing enclosure. Advantageously, a receiving housing 42 comprises an outlet 46 for the powder deposited in excess and entrained inside the receiving housing by the device 20 for producing a layer of powder. This outlet 46 forms a collection tank for the excess deposited powder or conducts the excess deposited powder to a collection tank.In the case where the powder distribution device 18 is mounted on the device 20 for producing a layer of powder, the receiving housing 42 may also comprise a powder inlet 48 for supplying the device 20 for producing a layer of powder. This powder inlet 48 is for example connected to a reservoir of new powder and equipped with means for dosing the powder delivered to the powder distribution device.

[0070] According to the invention, a diffuser 26 is a porous wall or a wall comprising a plurality of openings. In the case of a porous wall, the pores of a diffuser have an average diameter of between 0.1 and 1000 μm. In the case of a wall comprising a plurality of openings, these openings may take the form of slots and / or orifices distributed over the entire surface of the wall constituted by the diffuser. For example, a diffuser 26 takes the form of a wall comprising a plurality of parallel slots with a height of between 5 and 20 mm. For example, the slots of a diffuser 26 extend over the entire variable width of the wall constituted by this diffuser. For example, a diffuser 26 may take the form of a grid positioned at the outlet of a pipe whose section increases up to this gas flow outlet grid.Such a grid can consist of horizontal fins, honeycomb-shaped separating walls, a perforated plate, etc.

[0071] According to the invention, a collector 28 does not take the form of a porous wall because the pores of such a wall could quickly become clogged by deposits of smoke particles. According to the invention, a collector 28 is a wall comprising a plurality of openings. These openings may take the form of slots and / or orifices distributed over the entire surface of the wall constituted by the collector. For example, a collector 28 takes the form of a wall comprising a plurality of parallel slots with a height of between 5 and 20 mm. For example, the slots of a collector 28 extend over the entire variable width of the wall constituted by this collector. For example, a collector 28 may take the form of a grid positioned at the outlet of a pipe whose section increases up to this outlet grid of the flow of gas. Such a grid can consist of horizontal fins, honeycomb-shaped separating walls, a perforated plate, etc.

[0072] According to the invention, a collector 28 and a diffuser 26 extend over at least 90% of the height H of the manufacturing enclosure 10 and of the circulation volume(s) VI, V2 of a gas flow. The height H of the manufacturing enclosure 10 and of the circulation volume(s) VI, V2 of a gas flow corresponds to the distance between the work surface 12 or the manufacturing plate 14 at the start of the manufacturing cycle and the window 24 forming the ceiling of the manufacturing enclosure 10.

[0073] In the manufacturing enclosure 10 of the additive manufacturing machine according to the invention, the device 20 for producing a layer of powder is mounted on translational guiding and driving means 50, and in which these translational guiding and driving means 50 are housed in clearances 52 provided in the work surface 12 and on either side of the manufacturing plate 14. For example, these translational guiding and driving means 50 comprise rails and / or guide rollers and a mechanical drive by an electric motor via pinions and / or a belt. Advantageously, the clearances 52 comprise a protective strip 54 for the translational guiding and driving means. A protective strip 54 prevents the additive manufacturing powder from penetrating inside a clearance 52.

[0074] As indicated previously, in an additive manufacturing machine according to the invention, a diffuser 26 and a collector 28 which are located on either side of the same circulation volume VI,V2 of a gas flow are connected by a ventilation duct 30 which is located outside the manufacturing enclosure 10. Preferably, this ventilation duct 30 is of the same height as the diffuser and the collector which it connects, and therefore of the same height as the manufacturing enclosure and the circulation volume(s) of a gas flow.

Claims

Claims

1. Powder bed deposition additive manufacturing machine, the machine comprising: - a manufacturing enclosure (10) comprising a work surface (12) and a manufacturing plate (14) capable of receiving a layer of powder, as well as a front wall (PAV), a rear wall (PAR) and two right and left side walls (PLD, PLG), - a powder distribution device (18) for distributing powder inside the manufacturing enclosure, - a device (20) for producing a layer of powder for producing a layer of powder above the manufacturing plate (14), - at least one source for selective consolidation (22) of a layer of powder by total or partial fusion, this selective consolidation source being located outside the manufacturing enclosure and emitting at least one beam (F) of selective consolidation which penetrates into the manufacturing enclosure via a window (24), - at least one circulation volume (V1,V2) of a gas flow (F1, F2) located inside the manufacturing enclosure, and - a diffuser (26) of a gas flow and a collector (28) of a gas flow located on either side of a circulation volume of a gas flow, the additive manufacturing machine being characterized in that the right (PLD) and left (PLG) side walls of the manufacturing enclosure are constituted by a diffuser (26) and / or a collector (28), and in that these right (PLD) and left (PLG) side walls geometrically correspond to the outer limits of the displacement volume of the selective consolidation beam(s) traveling through the circulation volume(s) of a gas flow to reach any point on the upper surface of the manufacturing plate.,

2. Additive manufacturing machine according to claim 1, in which the right (PLD) and left (PLG) side walls of the manufacturing enclosure are inclined towards each other so that the distance between these side walls decreases as one moves away from the manufacturing plate (14) and approaches the selective consolidation source(s) (22).

3. Additive manufacturing machine according to claim 2, wherein the right (PLD) and left (PLG) side walls of the fa- The bricks are inclined at an angle of no more than 20° relative to a vertical plane.

4. Additive manufacturing machine according to one of claims 1 to 3, in which the front (PAV) and rear (PAR) walls of the manufacturing enclosure geometrically correspond to the outer limits of the volume of movement of the selective consolidation beam(s) traveling through the volume(s) of circulation of a gas flow to reach any point on the upper surface of the manufacturing plate (14).

5. Additive manufacturing machine according to claim 4, in which the front (PAV) and rear (PAR) walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front (PAV) and rear (PAR) walls decreases as one moves away from the manufacturing plate and approaches the selective consolidation source(s).

6. Additive manufacturing machine according to claim 4, in which the front (PAV) and rear (PAR) walls of the manufacturing enclosure are inclined towards each other, preferably at an angle of 20° at most relative to a vertical plane, so that the distance between these front and rear walls increases as one moves away from the manufacturing plate and approaches the selective consolidation source(s).

7. Additive manufacturing machine according to one of claims 1 to 6, in which the manufacturing enclosure (10) and the circulation volume(s) (VI, V2) of a gas flow extend in height over the entire distance (D) separating the selective consolidation source(s) from the manufacturing plate.

8. Additive manufacturing machine according to one of claims 1 to 6, in which the manufacturing enclosure (10) and the circulation volume(s) (V1, V2) of a gas flow extend in height only over part of the distance (D) separating the selective consolidation source(s) from the manufacturing plate.

9. Additive manufacturing machine according to claim 8, in which the manufacturing enclosure (10) and the circulation volume(s) (VI, V2) of a gas flow extend in height over less than half the distance (D) separating the selective consolidation source(s) from the manufacturing plate.

10. Additive manufacturing machine according to one of the preceding claims, in which the manufacturing enclosure comprises at least one receiving housing (42) for the device (20) for producing a layer of powder, and possibly for the powder distribution device (18), this receiving housing being equipped with a closing flap (44).

11. Additive manufacturing machine according to claim 10, wherein a receiving housing (42) is provided in the front wall (PAV) and / or in the rear wall (PAR) of the manufacturing enclosure.

12. Additive manufacturing machine according to one of claims 10 or 11, in which a receiving housing (42) comprises an evacuation (46) for the powder deposited in excess and entrained inside the receiving housing by the device (20) for producing a layer of powder.

13. Additive manufacturing machine according to one of the preceding claims, in which a diffuser (26) is a porous wall or a wall comprising a plurality of openings taking the form of slots and / or orifices distributed over the entire surface of this wall, and in which a collector (28) is a wall comprising a plurality of openings taking the form of slots and / or orifices distributed over the entire surface of this wall.

14. Additive manufacturing machine according to claim 13, in which a collector (28) and a diffuser (26) extend over at least 90% of the height (H) of the manufacturing enclosure and of the circulation volume(s) of a gas flow.

15. Additive manufacturing machine according to one of the preceding claims, in which the device (20) for producing a layer of powder is mounted on translational guidance and drive means (50), and in which these translational guidance and drive means are housed in clearances (52) provided in the work surface (12) and on either side of the manufacturing plate (14).

16. Additive manufacturing machine according to claim 15, in which the clearances comprise a protective strip (54) for the translational guide and drive means.

17. Additive manufacturing machine according to one of the preceding claims, in which the manufacturing enclosure (10) comprises a single circulation volume (VI) of a gas flow and a plurality of sources of selective consolidation (22).

18. Additive manufacturing machine according to one of claims 1 to 17, in which the manufacturing enclosure comprises at least two circulation volumes (VI, V2) of a gas flow juxtaposed between the right (PLD) and left (PLG) side walls of the manufacturing enclosure, and a plurality of selective consolidation sources (22) aligned above each circulation volume of a gas flow.

19. Additive manufacturing machine according to claim 18, in which each circulation volume (VI, V2) of a gas flow is located between a diffuser (26) and a collector (28) dedicated to this circulation volume of a gas flow, a collector / collector assembly (34) or a diffuser / diffuser assembly (38) being interposed between the two circulation volumes of a gas flow.

Images