Device and method for additive manufacturing with dusting of a powder spreading carriage

Abstract

The invention relates to an additive manufacturing device (1) comprising an enclosure (3) and a conveyor (5A, 5B, 29A, 29B) configured to recirculate manufacturing powder, the enclosure (3) comprising: - a work-holding platform (7); - a carriage (13) configured to spread powder on top of the work-holding platform (7); - a dusting appliance (23A, 23B, 33) included in the carriage (13) and configured to trigger a jolt or a vibration in the carriage and remove powder from the carriage; and - an inlet of the conveyor (5A, 5B, 29A, 29B), the device being configured to feed removed powder (42) from the carriage (13) into the inlet of the conveyor (5A, 5B, 29A, 29B), the inlet (6A, 6B) being located between the work-holding platform (7) and an end-of-travel position of the carriage.

Description

[0001] Device and method for additive manufacturing with depowdering of a powder spreading carriage

[0002] FIELD OF THE INVENTION

[0003] The invention relates to additive manufacturing which requires spreading of the additive manufacturing powder for example by a powder spreading carriage.

[0004] STATE OF THE ART

[0005] In additive manufacturing devices that require powder spreading, it is necessary to use a system capable of transporting and spreading the powder, such as a powder spreading cart, on the manufacturing area, such as a manufacturing part-carrying platform.

[0006] The powder moved by the carriage, as well as the unconsolidated powder at the end of manufacturing, can spread inside the enclosure. In particular, the spreading carriage can be covered with an unwanted layer of powder. When the spreading carriage moves over the workpiece platform, it produces the expected working surface of the powder layer before consolidation. The good condition of this working surface is necessary for the good quality of the manufactured part. There is a risk that some of the unwanted powder layer will fall from the carriage onto this working surface. The surface condition of the powder layer is then deteriorated just before consolidation, and there is a risk of poor quality of the manufactured part or the manufactured object.

[0007] There is therefore a need to better control the pollution from the powder generated during the powder spreading stage.

[0008] STATEMENT OF THE INVENTION

[0009] One aim of the invention is to better control the pollution by the powder generated during the powder spreading stage.

[0010] The aim is achieved within the framework of the present invention thanks to an additive manufacturing device comprising an enclosure and a conveyor configured to recycle manufacturing powder, the enclosure comprising:

[0011] - a workpiece-carrying platform,

[0012] - a trolley configured to spread powder above the workpiece platform,

[0013] - a dedusting apparatus configured to remove powder from the carriage, and - an inlet of the conveyor, the device being configured to bring powder removed from the carriage into the inlet of the conveyor or into a reserve, the reserve extending inside the enclosure and comprising at least one wall distinct from the walls of the enclosure.

[0014] Such a device is advantageously and optionally supplemented by the following different characteristics taken alone or in combination:

[0015] - the conveyor inlet or the reserve is located opposite an end-of-travel position of the carriage, the depowdering device being configured to be triggered when the carriage is at the end of its travel so that the powder falls by gravity into the conveyor inlet or into the reserve;

[0016] - the device is configured to feed powder removed from the carriage into the inlet of the conveyor, the inlet being located between the workpiece platform and an end-of-travel position of the carriage, the depowdering apparatus being mounted on the carriage and configured to be triggered when the carriage is directly above the inlet

[0017] - the device is configured to bring powder removed from the carriage into the inlet of the conveyor, the inlet being located between the workpiece platform and an end-of-travel position of the carriage, the device further comprising a movement member separate from the conveyor and configured to move the powder removed from the carriage into the inlet;

[0018] - the moving member is a scraper mounted on the carriage and configured to be in an active configuration in which the scraper is in contact with a bench in the enclosure and in a passive configuration in which the scraper is located above the bench; and

[0019] - the moving member is a flap movable in rotation and configured to be in an active configuration in which the flap is inclined towards the entrance of the conveyor and in a passive configuration in which the flap is horizontal.

[0020] The invention also relates to an additive manufacturing method comprising the following steps

[0021] - using a trolley, spreading a manufacturing powder on a part-carrying platform included in an enclosure,

[0022] - removal of powder from the trolley, and

[0023] - recycling of the removed powder by a transporter or storing the removed powder in a reserve, the reserve extending inside the enclosure and comprising at least one wall separate from the walls of the enclosure. Such a method is advantageously and optionally supplemented by the following different characteristics taken alone or in combination:

[0024] - powder removal is triggered after a step of moving the carriage to the end of its travel, so that during powder removal, the removed powder falls by gravity into the conveyor inlet or into the reserve;

[0025] - the powder removal is triggered after a step of moving the carriage vertically above the inlet of the conveyor between the workpiece platform and an end-of-travel position of the carriage, so that during the powder removal, the removed powder falls by gravity into the inlet of the conveyor;

[0026] - the method comprises, after the removal of powder, an intermediate step of moving the removed powder into the inlet of the conveyor;

[0027] - the intermediate movement is ensured by a scraper mounted on the carriage and configured to be in contact with a bench; and

[0028] - the intermediate movement is provided by a rotating movable flap configured to tilt towards the entrance of the conveyor.

[0029] DESCRIPTION OF FIGURES

[0030] Other characteristics and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and must be read in conjunction with the appended drawings in which: Figures 1 to 7 are schematic representations of a detail of an additive manufacturing device according to different embodiments of the invention.

[0031] DETAILED DESCRIPTION OF THE INVENTION

[0032] Additive manufacturing device

[0033] With reference to figures 1 to 7, an additive manufacturing device 1 comprises an enclosure 3 in which the manufacturing of an object can be carried out by consolidation of an additive manufacturing powder.

[0034] Enclosure 3 comprises different walls that define a working chamber inside. Enclosure 3 is sealed. The gaseous environment inside enclosure 3 can be controlled; in particular, enclosure 3 can be filled with an inert gas that does not alter the additive manufacturing powder.

[0035] The manufacturing powder is placed on a workpiece platform 7 before being consolidated. The workpiece platform 7 comprises an upper surface which is horizontal. With reference to Figures 1 to 7, the x and y axes define a horizontal plane, the z axis is oriented vertically upwards. The workpiece platform is rectangular oriented along the x and y axes. The workpiece platform has a main length along the x axis and a transverse length along the y axis. The direction of the x axis is defined as the main direction and the direction of the y axis as the transverse direction.

[0036] The object is manufactured layer by layer: a first layer of powder spread on the workpiece platform is selectively consolidated, then a second layer of powder is spread above the first layer before being consolidated in turn and merged with the previous layer. Above the workpiece platform 7, a plurality of layers 9 are therefore stacked as manufacturing progresses. The workpiece platform 7 can be movable in translation in the vertical direction. With each new layer spread, the workpiece platform 7 can translate vertically, therefore along the z axis, downwards by a distance corresponding to the thickness of a layer. In this way, the last layer spread, referenced 11 in the figures, is always at the same height in the enclosure 3.

[0037] The enclosure comprises a bench 10 which extends around the workpiece platform 7. The bench 10 is a single-piece part which surrounds the entire workpiece platform 7. The bench 10 vertically separates the manufacturing line which is located above the bench 10 and the lower part of the manufacturing machine. The bench 10 defines by its upper edge a wall which ensures the seal between the manufacturing line and the lower part, with respect to the manufacturing powder. The seal can also be ensured with respect to the gas. The bench 10 makes it possible to reduce the number of junctions and / or joints necessary to ensure the seal. The bench 10 defines a wall whose maximum vertical position is close to, or even coincides with, the vertical position of the last spread layer 11.In this way, the bench 10 and the last spread layer 11 form a continuous horizontal surface if there is no vertical gap between the bench 10 and the last spread layer 11, or a quasi-continuous horizontal surface if there is a slight vertical gap between them.

[0038] The powder is introduced into the enclosure 3 by a conveying system 5A, 5B. The system comprises, for example, two drawers which extend in the transverse direction, along the y axis, over the entire transverse length of the workpiece platform. The drawers are movable in translation in the transverse direction and comprise an upper surface on which a continuous bead of manufacturing powder is deposited. The two beads can thus be positioned in the main direction on either side of the workpiece platform 7, each bead extending over the entire transverse length of the workpiece platform. The conveying system 5A, 5B thus makes it possible to bring the powder close to the workpiece platform. The drawer occupies a volume defined by a hollow or depression in the bench 10. The upper surface of the bench 10 has a hollow in which the drawer is housed.The upper surface on which the powder is placed has a vertical position which is close to, or even coincides with, the maximum vertical position of the bench 10. In this way, the upper surface of the drawers of the conveyor system 5A, 5B and the bench 10 form a continuous or quasi-continuous horizontal surface.

[0039] The conveyor system 5A, 5B also includes a recycling path that allows automatic recycling of powder that enters through an inlet 6A, 6B of the system 5A, 5B. For example, the recycling path of the conveyor system 5A, 5B includes a gutter located below the inlet 6A, 6B that can receive the powder and an endless screw that can carry the received powder to a reservoir that extends, for example, outside the enclosure, or to a recycling circuit or even to a suction and filtering system that replaces the powder in a main hopper of the additive manufacturing device. It is thus possible to subsequently spread this recycled powder on the part-carrying platform.

[0040] The conveyor system 5A, 5B is configured to convey the powder close to the workpiece platform 7 so that the drawers and the inlets 6A and 6B are located close to the workpiece platform 7. In the main direction parallel to the x axis, the drawers and the inlets 6A and 6B have the positions 18A 18B which are located between the workpiece platform and the end-of-travel positions 17 and 19 of the carriage.

[0041] The additive manufacturing device 1 comprises a carriage 13 configured to spread powder above (or on) the workpiece platform 7. The carriage 13 is mounted movably inside the enclosure and moves in the main direction parallel to the x axis. More precisely, the carriage 13 can be moved in translation along a ramp 15 which is directed in the main direction. The carriage 13 is configured to move over a stroke 21 defined between a first end-of-stroke position 17 and a second end-of-stroke position 19. The stroke 21 corresponds to the length of the ramp 15 in the main direction.

[0042] The carriage 13 is configured to move above the workpiece platform 7 over the entire main length of the workpiece platform. The travel 21 of the carriage covers the main length along the x axis of the workpiece platform 7.

[0043] The carriage 13 comprises in its lower part a member 14 configured to be in contact with the powder and spread it along a horizontal plane. For example, the member can be a roller or a scraper.

[0044] For this purpose, the carriage 13 and the member 14 each extend in the transverse direction over a length greater than or equal to the transverse length of the workpiece-carrying platform. The carriage 13 is configured to move above the drawers of the conveyor system 5A, 5B in order to be able to distribute the powder above the workpiece-carrying platform 7.

[0045] The carriage 13 is configured to move continuously above the powder supply locations and the workpiece platform. In other words, the carriage 13 is configured to move above the bench 10.

[0046] When the carriage is moved and comes into contact with the powder, the carriage may become covered with an undesirable layer of powder. The device comprises a depowdering apparatus which is configured to remove at least part of the powder which thus accumulates on the carriage.

[0047] Powder removal device

[0048] Different embodiments of this dedusting device are possible.

[0049] With reference to figures 1, 2 and 5, a first embodiment of the depowdering apparatus uses the stops 23A and 23B of the carriage 13. The stops 23A and 23B are located at the ends of the ramp 15 so that when the carriage is at the end of its travel it is in contact with one of these stops. A depowdering apparatus can be produced by implementing an impact 40 between the carriage and the stops 23A and 23B. In particular, the carriage can be propelled against the stop. In this first embodiment, the depowdering apparatus is mounted fixed in the device 1. During the impact 40, a quantity of powder 42 falls from the carriage 13 according to the movement illustrated by the arrow 44.

[0050] Referring to Figures 3 and 4, a second embodiment of the depowdering apparatus uses a depowdering apparatus 33 mounted on the carriage 13. The depowdering apparatus 33 then forms part of the carriage 13 and moves together with the carriage 13. The depowdering apparatus 33 may be, for example, a striker comprising a spring which may be compressed under the action of a pressurized inert gas supplied into a cylinder of the striker. Upon receipt of a trigger signal, the compressed inert gas may be released from the cylinder, thereby releasing the spring which carries a coin which strikes the body of the carriage 13. Alternatively, the depowdering apparatus 33 may be a vibrating system which, upon receipt of a trigger signal, begins to oscillate, agitating the carriage to which the vibrating system is attached. The depowdering apparatus is configured to be able to trigger a shock or vibration in the carriage.The depowdering apparatus is an active component that is powered to deliver the shock or vibration to the carriage. During the shock or vibration 40, a quantity of powder 42 falls from the carriage 13 according to the movement illustrated by the arrow 44. In the remainder of the text, we refer to this quantity of powder 42 that falls from the carriage 13 as "removed powder". The shock or vibration can be triggered at will so that the location of the depowdering can be chosen, that is to say the location where powder is removed from the carriage.

[0051] Places of delivery of the powder removed from the cart

[0052] The device 1 is configured to bring the removed powder 42 from the carriage into one of the two locations presented below and corresponding to the following two options.

[0053] According to a first option, the powder removed from the trolley is brought into a reserve, the reserve extending inside the enclosure and comprising at least one wall separate from the walls of the enclosure.

[0054] Figure 1 illustrates this first option. The device 1 comprises in this first option at least one of the two reserves 25A, 25B. When the device 1 comprises the two reserves, these are located in the main direction, parallel to the x axis, on either side of the workpiece platform 7, advantageously symmetrically. A reserve 25A, 25B extends inside the enclosure 3. A reserve 25A, 25B is defined by walls 27A, 27B. These walls 27A, 27B are distinct from the walls of the enclosure 3. A reserve 25A, 25B defines a storage volume suitable for receiving powder, the storage volume being entirely included in the working chamber defined by the enclosure 3. As illustrated, the reserves may be hollow or depression volumes defined in the bench 10. In other words, the upper surface of the bench 10 may have, from its maximum vertical position, a hollow or depression.This hollow corresponds to the walls 27A, 27B which extend from the maximum vertical position of the bench 10 downwards. The hollow defines a storage volume which is located below the maximum vertical position of the bench 10. The reserve in this case has walls all located below the maximum vertical position of the bench 10 and the reserve is open upwards. This opening makes it possible to receive the powder. The storage volume can then be defined by the walls and a virtual closure given by the vertical position of the bench 10.

[0055] Advantageously, the storage volume is chosen to be greater than or equal to four liters.

[0056] In a second option, the powder removed from the cart is brought into the inlet of a conveyor configured to recycle manufacturing powder.

[0057] This conveyor is configured, for example, to receive the removed powder and transport it to the circulation system for the powder intended to be spread so that the removed powder is spread again on the workpiece platform. The conveyor is configured to transport the powder received at the input so as to subsequently spread the powder on the workpiece platform. For example, the conveyor can carry the removed powder to a reservoir, or to a recycling circuit, or even to a suction and filtering system which replaces the powder in a main hopper of the additive manufacturing device.

[0058] The transporter may in a first variant be the recycling route of the convoy system 5A, 5B described previously.

[0059] In a second variant illustrated in Figure 2, the conveyor may be separate from the recycling path of the conveyor system 5A, 5B. The conveyor is then a recovery bin 29A, 29B connected to a powder suction system. The recovery bin 29A, 29B extends inside the enclosure 3. The recovery bin 29A, 29B is defined by walls separate from the walls of the enclosure 3. The recovery bin 29A, 29B defines a volume suitable for receiving powder, fully included in the working chamber defined by the enclosure 3. As illustrated, the recovery bin may define a hollow or depression volume in the bench 10. In other words, the walls of the bin extend from the maximum vertical position of the bench downwards and define a volume which is located below this maximum vertical position of the bench 10.The recovery tank in this case has walls all located below the vertical position of the bench 10 and it is open upwards. This opening allows the powder to be received. The reservation tank comprises in its lowest part, at the bottom of the tank, an orifice which is connected via a conduit 31 A, 31 B to a powder suction system. The powder suction system is configured to send the powder received in the recovery tank via the orifice and the conduit 31 A, 31 B to a reservoir, or to a recycling circuit or even to the system for circulating the powder intended to be spread so that the removed powder is spread again on the workpiece platform.

[0060] As illustrated in Figure 2, the device 1 may comprise two conveyors located in the main direction, parallel to the x axis, on either side of the workpiece-carrying platform 7, advantageously symmetrically.

[0061] In common with the first option and the second option presented, the device can be configured in the following first configuration: the conveyor inlet or the reserve is located opposite an end-of-travel position of the carriage, the depowdering device being configured to be triggered when the carriage is at the end of its travel so that the powder falls by gravity into the conveyor inlet or into the reserve.

[0062] This first configuration is illustrated in Figures 1 and 2.

[0063] The end-of-travel positions 17 and 19 have been previously presented. When the carriage reaches one of these positions and is therefore in contact with one of the stops 23A, 23B, then the inlet of the conveyor or the reserve is located vertically below the carriage 13. In this first configuration, the conveyor can be a recovery bin 29A, 29B connected to a powder suction system. On the other hand, the conveyor cannot be the recycling path of the conveyor system 5A, 5B because the inlets 6A, 6B have positions 18A 18B different from the end-of-travel positions 17 and 19 of the carriage.

[0064] The different embodiments of the depowdering device presented previously are compatible with this first configuration.

[0065] In relation to the second option presented, the device can be configured for the following second configuration: the inlet of the conveyor is located between the workpiece platform and an end-of-travel position of the carriage, the depowdering device being mounted on the carriage and configured to be triggered when the carriage is vertically aligned with the inlet. The depowdering device thus depowders the carriage when the latter is vertically aligned with the inlet.

[0066] This second configuration is illustrated in Figure 3.

[0067] In this second configuration, the conveyor can be the recycling path of the convoy system 5A, 5B because the inputs 6A, 6B have positions 18A 18B different from the end-of-travel positions 17 and 19 of the carriage 13.

[0068] When the carriage 13 is directly above the entrance of the conveyor, the carriage 13 is distant from the stops 23A, 23B, so that the depowdering apparatus which uses the stops 23A and 23B of the carriage 13 cannot be used to depowder the carriage 13. The second embodiment of the depowdering apparatus mounted on the carriage 13 is therefore used in this second configuration.

[0069] Moving body

[0070] Still in relation to the second option presented, the device can be configured for the following third configuration: the inlet of the conveyor is located between the workpiece platform and an end-of-travel position of the carriage, the device further comprising a movement member separate from the conveyor and configured to move the powder removed from the carriage into the inlet.

[0071] This third configuration is illustrated in a first variant in figures 4 and 5 and in a second variant in figures 6 and 7.

[0072] In this third configuration, the conveyor can be the recycling path of the convoy system 5A, 5B because the inputs 6A, 6B have positions 18A 18B different from the end-of-travel positions 17 and 19 of the carriage 13.

[0073] This third configuration does not require the carriage 13 to be directly above the conveyor inlet for the depowdering to be triggered. The various embodiments of the depowdering apparatus presented previously are compatible with this third configuration: Figure 4 illustrates the second embodiment of the depowdering apparatus 33 and Figure 5 illustrates the first embodiment of the depowdering apparatus 23A.

[0074] The additive manufacturing device 1 in this third configuration comprises a movement member 34A, 34B, 35A, 35B separate from the conveyor and configured to move the powder removed from the carriage into the inlet of the conveyor.

[0075] Different embodiments of this movement member are possible.

[0076] In a first embodiment of the displacement member illustrated in Figures 4 and 5, the member is a scraper 34A, 34B mounted on the carriage and configured to be in an active configuration in which the scraper 34A, 34B is in contact with the bed 10 and in a passive configuration in which the scraper is located above the bed 10.

[0077] The carriage 13 comprises the scraper 34A, 34B which is located projecting from the carriage 13 in the main direction. The carriage may comprise a first scraper 34A on one side and a second scraper 34B on the other side relative to the main direction. The scraper 34A, 34B extends in the transverse direction over a length greater than or equal to the length of the carriage in this same transverse direction. The scraper 34A, 34B comprises a deformable part which constitutes its lowest part. The scraper 34 is mounted movably relative to the carriage 33 and in particular it is mounted movably in vertical translation, along the z axis. The scraper is configured to pass from an active configuration to a passive configuration and vice versa.

[0078] In the active configuration the scraper 34A, 34B is in a low position so that the deformable part is in contact with the bench 10.

[0079] In the passive configuration, the scraper 34A, 34B is in a high position so that the deformable part is not in contact with the bench 10, it is above the bench 10.

[0080] The scraper can be moved vertically from the active configuration to the passive configuration by cylinders mounted on the carriage, the scraper being mounted on the cylinders.

[0081] In Figures 4 and 5, the carriage 13 comprises two scrapers 34A, 34B, the scraper 34A is shown in its active configuration and the scraper 34B is shown in its passive configuration.

[0082] When the carriage is depowdered by an impact 40, the removed powder 42 falls onto the bench 10. In its active configuration, the scraper is in contact with the bench 10. Setting the carriage in motion when the scraper is in its active configuration makes it possible to move the scraper while maintaining its contact with the bench 10. It is possible to put the scraper in contact with the removed powder and to move the powder against the scraper. This produces an intermediate movement of the powder which serves to place the removed powder at the inlet of the conveyor.

[0083] It should be noted that when the additive manufacturing device comprises a movement member in the form of a scraper 34A, 34B mounted on the carriage via jacks, this scraper can act as a depowdering device configured to mechanically excite the carriage and remove powder deposited on the carriage. The energy of the impact is then produced using the jacks for moving the scraper when they reach the stop.

[0084] In a second embodiment of the displacement member illustrated in Figures 6 and 7, the member is a flap 35A, 35B movable in rotation and configured to be in an active configuration in which the flap 35A, 35B is inclined towards the entrance of the conveyor and in a passive configuration in which the flap is horizontal.

[0085] The flap 35A, 35B is included in the enclosure 3. The flap 35A, 35B is located contiguously to the conveyor inlet in the main direction so that the conveyor inlet is placed between the flap 35A, 35B and the workpiece platform. The flap 35A, 35B is mounted to rotate about a horizontal rotation axis 36A, 36B. The horizontal rotation axis is parallel to the transverse direction illustrated by the y-axis in Figures 6 and 7. The rotation axis passes through the flap 35A and is located contiguously to the conveyor inlet.

[0086] The flap 35A, 35B extends in the main direction from the horizontal rotation axis to the stop 23A, 23B.

[0087] The flap 35A, 35B is configured to switch from an active configuration to a passive configuration and vice versa.

[0088] In the active configuration the flap 35A, 35B is inclined relative to the horizontal plane so that the flap 35A, 35B rises above the vertical position of the bench 10. The flap 35A, 35B is inclined towards the conveyor inlet in the sense that an object located on the upper surface of the flap is attracted by gravity towards the conveyor inlet.

[0089] In the passive configuration, the flap 35A, 35B is oriented along a horizontal plane so that an upper surface of the flap 35A, 35B is located in the extension of the bench 10. The carriage 13 can then move above the flap 35A, 35B and stop above it. The device can comprise two flaps 35A, 35B which are located on either side of the part-carrying platform when the conveyor system 5A, 5B comprises two drawers and therefore two conveyor inlets 6A, 6B.

[0090] Additive manufacturing process

[0091] An additive manufacturing device as just presented makes it possible to implement a method according to the invention to better control the pollution by the powder generated during the powder spreading step.

[0092] We will present the different stages of the process.

[0093] During a first step and by means of the carriage 13, a manufacturing powder is spread on the part-carrying platform 7 included in the enclosure 3.

[0094] This first step may include, for example:

[0095] - the supply of a powder cord on a drawer of the convoy system 5A, 5B,

[0096] - prior to supplying the cord, positioning the carriage 13 so that the drawer is located between the part-carrying platform 7 and the carriage 13,

[0097] - the movement of the carriage 13 in a spreading direction towards the drawer and the workpiece platform 7, so that the powder deposited on the drawer is carried by the member 14 of the carriage towards the workpiece platform, and as the carriage travels over the first length of the workpiece platform, the spreading of the powder spread on the workpiece platform by the member 14.

[0098] In a second step, powder that undesirably covers the carriage 13 is removed. This second step is also referred to as depowdering the carriage.

[0099] This second step is carried out after the first step. Advantageously, and before the depowdering of this second step, the carriage 13 continues its movement in the spreading direction beyond the part-carrying platform. In this way, the removed powder does not deposit on the layer of powder that has just been deposited.

[0100] The depowdering apparatus according to one of the previously described modes is triggered and it produces a shock or vibrations 40 on the carriage 13 so that powder 42 is removed from the carriage 13 according to the movement 44.

[0101] In a third step, the removed powder is

[0102] - either recycled by the carrier according to the first option already mentioned previously, - or kept in the reserve according to the second option already mentioned previously.

[0103] This third step is also referred to as isolation of the removed powder, in the sense that the risk of pollution of the newly deposited layer by this removed powder is greatly reduced.

[0104] In fact, the removed powder is, in all cases, kept away from the workpiece platform to prevent it from polluting the newly deposited layer and, more generally, the manufacturing process. Pollution from powder generated undesirably during the powder spreading stage is thus better controlled.

[0105] Advantageously, the last two steps described above can be carried out after each planned spreading of the powder during the manufacturing process. It is also possible to choose to carry them out at a lower spreading frequency, for example after each group of two successive spreadings, or after each group of a greater number of successive spreadings.

[0106] When the removed powder is stored in the reserve, it is advantageous for the reserve to have a volume greater than or equal to four liters. In this way, the trolley can be dedusted a large number of times before the reserve is full. This limits the frequency of human intervention on the device to empty the reserve.

[0107] In a manner common to the first option and the second option recalled above, the method can be adapted according to a first adaptation so that the withdrawal of powder is triggered after a step of moving the carriage to the end of its travel, so that during the withdrawal of powder, the withdrawn powder falls by gravity into the inlet of the conveyor or into the reserve.

[0108] This first adaptation of the process corresponds to the first configuration of the device mentioned previously and illustrated in figures 1 and 2.

[0109] This first adaptation corresponds to a carriage 13 which, after spreading the powder, continues its movement in the spreading direction beyond the workpiece platform until the end of the stroke. The powder which undesirably covers the carriage is removed as far as possible from the workpiece platform, further limiting the risk of pollution of the spread layer.

[0110] After the impact 40 produced on the carriage 13 by the depowdering device, the removed powder 42 falls by gravity into the inlet of the conveyor or into the reserve, so that it is not necessary to provide an intermediate movement of the powder towards the inlet of the conveyor or into the reserve. When the device comprises at each end of travel of the carriage a conveyor inlet or a reserve, then it is possible to carry out the depowdering and isolation of the removed powder after each passage of the carriage above the workpiece platform 7.

[0111] In relation to the second option recalled above, the method can be adapted according to a second adaptation so that the powder removal is triggered after a step of moving the carriage vertically above the inlet of the conveyor between the workpiece platform and an end-of-travel position of the carriage, so that during the powder removal, the removed powder falls by gravity into the inlet of the conveyor.

[0112] This second adaptation of the process corresponds to the second configuration of the device mentioned previously and illustrated in figure 3. This second adaptation is linked to the second embodiment of the depowdering device.

[0113] This second adaptation can be implemented with the 5A, 5B convoy system already present in the device. It is not necessary to add a reserve or a recovery tank and a powder suction system in the device.

[0114] This second adaptation corresponds to a carriage 13 which, after having spread the powder, continues its movement in the spreading direction beyond the workpiece platform to the inlet 6A, 6B of the recycling path of the conveyor system 5A, 5B. The powder which undesirably covers the carriage is removed sufficiently far from the workpiece platform to satisfactorily limit the risk of pollution of the spread layer.

[0115] After the shock 40 or the vibrations produced on the carriage 13 by the depowdering device, the removed powder 42 falls by gravity into the inlet 6A, 6B of the conveyor, so that it is not necessary to provide an intermediate movement of the powder towards the inlet of the conveyor.

[0116] When the device comprises on either side of the part-carrying platform an inlet to the recycling track of the conveyor system 5A, 5B, then it is possible to carry out the depowdering and isolation of the powder removed after each passage of the carriage above the part-carrying platform 7.

[0117] Still in relation to the second option recalled above, and according to a third adaptation, the method can comprise, after the removal of powder, an intermediate step of moving the removed powder into the inlet of the conveyor.

[0118] This third adaptation is illustrated in a first variant in figures 4 and 5 and in a second variant in figures 6 and 7. This third adaptation of the method corresponds to the third configuration of the device mentioned previously and illustrated in a first variant in figures 4 and 5 and in a second variant in figures 6 and 7. This third adaptation is compatible with the different embodiments of the depowdering device presented previously.

[0119] This third adaptation can be implemented with the 5A, 5B convoy system already present in the device. It is not necessary to add a reserve or a recovery tank and a powder suction system in the device.

[0120] This third adaptation does not require that the carriage 13 be placed at a particular point in its travel for depowdering to be triggered. There is greater freedom in terms of carriage position. Furthermore, the intermediate displacement step of the removed powder can allow a larger quantity of removed powder to be brought to the inlet of the conveyor.

[0121] The first variant of the third adaptation corresponds to the case where the intermediate movement is ensured by the scraper 34A, 34B mounted on the carriage 13 and configured to be in contact with the bench 10.

[0122] In this second variant, the scraper 34A, 34B is by default in its passive configuration, that is to say in a high position so as not to come into contact with the bench 10 or the last layer of spread powder 11. In particular, during the step of spreading the powder on the part-carrying platform, the scraper 34A, 34B is in its passive configuration.

[0123] Depowdering can be triggered when the carriage 13 is beyond the workpiece platform and the conveyor inlet, i.e. when the conveyor inlet is located between the carriage and the workpiece platform. It should be noted that the shock 40 can be produced by the depowdering apparatus chosen in its first embodiment or in its second embodiment. In the first embodiment, the carriage 13 is placed at the end of its travel before depowdering is triggered. In the second embodiment, the carriage 13 is freely placed between this end of its travel and the conveyor inlet before depowdering is triggered.

[0124] Once the shock 40 is produced on the carriage 13 by the depowdering apparatus, the removed powder falls by gravity onto the bench 10. The scraper 34A, 34B is placed in its active configuration. This situation is illustrated in FIG. 4 when the depowdering apparatus corresponds to the second embodiment 33, and in FIG. 5 when the depowdering apparatus corresponds to the first embodiment 23A.

[0125] The carriage 13 is set in motion so that the scraper 34A moves the removed powder 42 into the inlet 6A, 6B of the conveyor. Once the removed powder 42 is inside the conveyor, the scraper 34A can be placed in the passive configuration.

[0126] In the case where the carriage 13 comprises two scrapers 34A, 34B on either side of the carriage in the main direction, it is the scraper furthest from the inlet of the conveyor which is placed in its active configuration and used to move the removed powder into the inlet of the conveyor.

[0127] The second variant of the third adaptation corresponds to the case where the intermediate movement is ensured by a flap 35A, 35B movable in rotation and configured to tilt towards the entrance of the conveyor.

[0128] In this second variant, the flap 35A, 35B is by default in its passive configuration, that is to say oriented horizontally. In particular, during the step of spreading the powder on the part-carrying platform, the flap 35A, 35B is in its passive configuration.

[0129] Depowdering can be triggered when the carriage 13 is beyond the workpiece platform and the conveyor inlet, i.e. when the conveyor inlet is located between the carriage and the workpiece platform. It should be noted that the shock 40 can be produced by the depowdering apparatus chosen in its first embodiment or in its second embodiment. In the first embodiment, the carriage 13 is placed at the end of its travel before depowdering is triggered. In the second embodiment, the carriage 13 is freely placed between this end of its travel and the conveyor inlet before depowdering is triggered.

[0130] Powder removal can be triggered when the carriage 13 is located above the flap 35A, 35B which is in its passive configuration, i.e. oriented horizontally.

[0131] Once the shock 40 is produced on the carriage 13 by the depowdering device, the removed powder 42 falls by gravity onto the flap 35A, 35B. This situation is illustrated in figure 6.

[0132] The carriage 13 is then moved towards the workpiece platform so that it is no longer above the flap 35A, 35B.

[0133] The flap 35A, 35B is placed in its active configuration. This situation is illustrated in Figure 7. The flap 35A rotates about the axis of rotation 36A and thus rises above the axial position of the bench 10. The flap 35A tilts at an angle 37 and thus forms an inclined plane towards the inlet 6A of the conveyor. The removed powder 42 located on this inclined plane is then attracted by gravity to the bottom of the plane, i.e. into the inlet 6A of the conveyor. Once the removed powder 42 has been inside the conveyor, the flap 35A can be placed in the passive configuration.

[0134] It should be noted that at the end of the part manufacturing process, some of the residual powder present on the bench, and which has for example been removed from the carriage on the bench, can be spread on the last layer of the powder bed previously lowered under the surface of the bench. This powder is then extracted from the enclosure when the part-holding platform is removed, this powder is then treated by a depowdering machine which frees the manufactured part from the unconsolidated powder which surrounds it.

Claims

CLAIMS 1. Additive manufacturing device (1) comprising an enclosure (3) and a conveyor (5A, 5B, 29A, 29B) configured to recycle manufacturing powder, the enclosure (3) comprising: - a workpiece-carrying platform (7), - a carriage (13) configured to spread powder above the workpiece platform (7), - a dedusting apparatus (23A, 23B, 33) included in the carriage (13) and configured to trigger a shock or vibration in the carriage and remove powder from the carriage, and - a conveyor inlet (5A, 5B, 29A, 29B), the device being configured to bring removed powder (42) from the carriage (13) into the conveyor inlet (5A, 5B, 29A, 29B), the inlet (6A, 6B) being located between the workpiece platform (7) and an end-of-travel position of the carriage.

2. Device according to claim 1 configured to bring powder removed (42) from the carriage (13) into the inlet (6A, 6B) of the conveyor, the device further comprising a moving member (34A, 34B, 35A, 35B) separate from the conveyor and configured to move the powder removed (42) from the carriage (13) into the inlet (6A, 6B).

3. Device according to claim 2 wherein the displacement member (34A, 34B) is a scraper (34A, 34B) mounted on the carriage (13) and configured to be in an active configuration in which the scraper (34A, 34B) is in contact with a bench (10) in the enclosure (3) and in a passive configuration in which the scraper (34A, 34B) is located above the bench (10).

4. Device according to claim 2 wherein the displacement member is a movable flap (35A, 35B) in rotation and configured to be in an active configuration in which the flap (35A, 35B) is inclined towards the inlet (6A, 6B) of the conveyor and in a passive configuration in which the flap (35A, 35B) is horizontal.

5. Additive manufacturing process comprising the following steps: - by means of a carriage (13), spreading of a manufacturing powder on a part-carrying platform (7) included in an enclosure (3), - removal of powder from the carriage by triggering a shock or vibration in the carriage by a depowdering device (23A, 23B, 33) included in the carriage (13), and - recycling of the powder removed by a conveyor (5A, 5B, 29A, 29B), an inlet (6A, 6B) of the conveyor being located between the workpiece-carrying platform (7) and an end-of-travel position of the carriage, the removal of powder.

6. Method according to claim 5 wherein the removal of powder is triggered after a step of moving the carriage directly above the inlet (6A, 6B), so that during the removal of powder, the removed powder (42) falls by gravity into the inlet (6A, 6B) of the conveyor.

7. Method according to claim 5 comprising, after the removal of powder, a step of intermediate movement of the removed powder into the inlet of the conveyor (6A, 6B).

8. Method according to claim 7 in which the intermediate movement is provided by a scraper (34A, 34B) mounted on the carriage (13) and configured to be in contact with a bench (10).

9. Method according to claim 7 wherein the intermediate movement is provided by a rotating movable flap (35A, 35B) configured to tilt towards the entrance of the conveyor (6A, 6B).

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