Additive manufacturing device and associated manufacturing method
The scraper blade's non-right angle design in additive manufacturing devices reduces mechanical stresses, enabling efficient production of multiple parts with complex geometries by minimizing contact zones, thus enhancing manufacturing efficiency.
Patent Information
- Application Number
- FR2021012373
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-11-23
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2041-11-23
AI Technical Summary
Existing additive manufacturing methods using selective laser melting face challenges in efficiently producing a large number of parts with complex geometries due to mechanical stresses caused by the scraper blade contacting parts with edges perpendicular to the scraping direction, limiting the maximum number of parts that can be formed on the plate.
The scraper blade is designed with a portion extending at a non-right angle to the scraping direction, reducing the contact zone and mechanical stresses by forming angles between 85° and 89° with the scraping direction, allowing for a compact arrangement of parts with perpendicular edges.
This design enables simultaneous manufacturing of a high number of parts with reduced mechanical stresses, optimizing the manufacturing rate and part density on the plate.
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Abstract
Description
Title of the invention: Additive manufacturing device and associated manufacturing method Technical field of the invention
[0001] The invention relates to the field of additive manufacturing, and in particular additive manufacturing by selective laser melting on a powder bed, also known as Selective Laser Sintering (SLS).
[0002] More specifically, the invention relates to an additive manufacturing device, as well as a method for manufacturing at least one part, implementing this device. State of the prior art
[0003] A method is known in the art which consists of manufacturing at least one part, in particular one or more metal part(s), by melting successive layers of powder using a laser beam controlled by an information processing system in which the three-dimensional coordinates of the points of the successive layers to be produced to form said parts have been recorded.
[0004] [Fig.l] illustrates a manufacturing device 1 intended to implement such a method.
[0005] The manufacturing device 1 comprises a reservoir 3 containing a metal powder 5 and the bottom 7 of which is movable, movable in translation vertically by a rod 9 of a jack, and a neighboring tank 11, substantially parallelepiped, the bottom of which is constituted by a movable plate 13, movable in translation vertically by a rod 15 of a second jack.
[0006] The manufacturing device 1 further comprises a scraper 17 for bringing powder from the reservoir 3 to the tank 11, the scraper 17 being movable in translation along a horizontal plane A substantially parallel to the plate 13. The manufacturing device 1 further comprises means 18 for generating a laser beam 19, coupled to a device 20 for moving said laser beam 19, making it possible to orient it and / or move it to reach any point of the tank 11.
[0007] To manufacture one or more parts 21, a first layer of powder is placed in the tank 11 using the scraper 17.
[0008] The layer then has a lower surface corresponding to the surface of the plate 13 and an upper surface on which the laser beam 19 is directed and moved. The energy provided by this beam causes the local melting of the powder which, by solidifying, forms a first layer of the or each part 21.
[0009] After formation of this first layer, the plate 13 is lowered by a distance corresponding to the thickness of a layer of powder, while the bottom 7 of the reservoir 3 is raised by a corresponding height, so that a certain quantity of powder 22 is located above the horizontal plane A.
[0010] Then, this quantity of powder 22 is brought by the scraper 17, from the reservoir 3 into the tank 11, to form a second layer over the previous layer. In the same way as previously, a second layer of each part 21 is formed using the laser beam 19. The quantity of powder and the positions of the bottom 7 and the plate 13 are determined so as to form layers of powder of a chosen and constant thickness.
[0011] These operations are repeated until the parts 21 are completely manufactured.
[0012] As shown in [Fig.2], the scraper 17 comprises a substantially rectilinear blade 23, movable in a back-and-forth movement in the horizontal plane A, in a scraping direction X. The blade 23 extends in a direction of extent E substantially parallel to the horizontal plane A and which forms a right angle α with the scraping direction X.
[0013] During the manufacture of the parts 21, an edge 25 of this blade 23 regularly comes into contact with the upper surface of said parts 21, which can generate mechanical stresses.
[0014] When the parts 21 have edges which extend perpendicular to the scraping direction X, which corresponds to an arrangement maximizing the number of parts 21 on the plate 23, a contact zone C between the edge 25 of the blade 23 and the parts 21 can have a significant extent, as shown in [Fig.2], which increases these constraints.
[0015] In this respect, it is known to orient the parts 21 so that their lateral edges extend at angles with the direction of extension of the blade 23 of the scraper 17, in order to reduce the width of the contacts between the blade 23 and the surface of said parts 21.
[0016] However, such an arrangement of the parts 21 may prove restrictive when a large number of parts are manufactured simultaneously. In particular for parts having a complex geometry, this reduces the maximum number of parts that can be formed on the plate. Presentation of the invention
[0017] The invention aims to remedy these drawbacks. As such, the invention relates to an additive manufacturing device comprising:
[0018] - a manufacturing tray, intended to receive at least one powder,
[0019] - a scraper comprising a blade extending in a substantially horizontal plane parallel to the plate, the blade being movable relative to the plate in a scraping direction substantially parallel to the plate,
[0020] characterized in that the blade comprises at least one portion extending locally in a direction of local extent forming a non-right angle with the scraping direction in the horizontal plane.
[0021] Such a device makes it possible to reduce the width of a contact zone between the edge of the blade and the edges of the parts oriented perpendicular to the scraping direction, and thus to limit the mechanical stresses during the movement of the scraper.
[0022] The blade may comprise at least one substantially rectilinear segment, extending in a direction of extent forming a non-right angle with the scraping direction in the horizontal plane.
[0023] The direction of extension of each segment can form an angle of amplitude between 85° and 89° with the scraping direction.
[0024] Such an angle value makes it possible to obtain a reduced contact width while maintaining a limited size of the blade. Here we consider the absolute value of the amplitude of the angle, without taking into account the orientation.
[0025] The blade may comprise at least two segments elongated along respective elongation directions forming non-right angles with the scraping direction, the segments forming at least one chevron.
[0026] Such a blade makes it possible to limit the size of the blade according to the scraping direction for a scraper blade having a significant length.
[0027] The blade has a curved profile in the horizontal plane.
[0028] The blade may have a sinusoidal profile in the horizontal plane.
[0029] The invention also relates to a method for manufacturing at least one part, implementing a device as above, the method comprising the following steps:
[0030] - movement of the scraper blade above the plate, according to the direction of scraping and forming a layer of powder on the plate,
[0031] - partial melting of a part of the powder layer by means of a laser beam and partial formation of each part, and
[0032] - movement of the scraper blade in the scraping direction and formation of a new layer of powder over the partially formed parts,
[0033] characterized in that the blade comprises at least one portion extending locally in a direction of extent forming a non-right angle with the scraping direction in the horizontal plane.
[0034] A plurality of parts may be manufactured simultaneously, the parts being arranged aligned with side edges of the parts perpendicular to the scraping direction. Brief description of the figures
[0035] [Fig.l] [Fig.l] is a schematic side view of a state-of-the-art additive manufacturing device,
[0036] [Fig.2] [Fig.2] is a schematic top view of the device of [Fig.l],
[0037] [Fig.3] [Fig.3] is a schematic top view of a manufacturing device additive according to a first embodiment of the invention, and
[0038] [Fig.4] [Fig.4] is a schematic top view of a manufacturing device additive according to a second embodiment of the invention. Detailed description of the invention
[0039] A manufacturing device 1 according to the invention will now be described, with reference to FIGS. 1 and 3.
[0040] As described previously, the manufacturing device 1 comprises a reservoir 3 containing a metal powder 5 and the bottom 7 of which is movable, movable in translation vertically by a rod 9 of a jack, and a neighboring tank 11, substantially parallelepiped, the bottom of which is constituted by a movable plate 13, movable in translation vertically by a rod 15 of a second jack.
[0041] The manufacturing device 1 further comprises a scraper 17 for bringing powder from the reservoir 3 to the tank 11, the scraper 17 being movable in translation along a horizontal plane A substantially parallel to the plate 13. The manufacturing device 1 further comprises means 18 for generating a laser beam 19, coupled to a device 20 for moving said laser beam 19, making it possible to orient it and / or move it to reach any point of the tank 11.
[0042] The scraper 17 manufacturing device according to the invention comprises a blade 23 movable relative to the plate 13 in a scraping direction substantially parallel to said plate 13.
[0043] As shown in [Fig.3], the blade 23 extends in the horizontal plane A, in a direction of extent E which forms a non-right angle a with the scraping direction X.
[0044] Thus, the contact zone C between the edge of the blade 23 and the part(s) 21 is of small extent, and in particular substantially punctual, when the parts 21 are arranged parallel to the edges of the plate 13.
[0045] This makes it possible to reduce the mechanical stresses exerted by the parts 21 on the blade 23 and to facilitate its movement.
[0046] Advantageously, the angle α between the direction of extension E of the blade 23 and the scraping direction X is between 85° and 89°. Such an angle value makes it possible to have the aforementioned advantages linked to a blade inclined relative to the scraping direction X, while reducing the size of the blade 23 in the scraping direction X.
[0047] According to a second embodiment, shown in [Fig.4], the blade 23 comprises two successive rectilinear segments 27 arranged in a chevron pattern, each segment 27 extending in a respective direction of extent E, E' forming a non-right angle α with the scraping direction X.
[0048] The directions of extent E, E' of the segments 27 form in particular respective angles α with the scraping direction X of the same amplitude and oriented in opposite directions to each other.
[0049] The use of a chevron blade 23 makes it possible to further reduce the size of the blade 23 in the scraping direction X.
[0050] The blade 23 may have three such segments 27, or more, and have a sawtooth profile.
[0051] More generally, the blade 23 comprises at least one section extending in a direction of extent E forming a non-right angle with the scraping direction X. Said section may be rectilinear or curved, with a local tangent forming a non-right angle with the scraping direction X.
[0052] The blade 23 may for example have a sinusoidal profile, or even a parabolic or hyperbolic profile.
[0053] The devices 1 according to the invention are particularly advantageous when they are implemented to simultaneously manufacture a plurality of parts 21 arranged aligned on the plate 13, with lateral edges 29 of said parts 21 perpendicular to the scraping direction X, as shown in [Fig.4].
[0054] Such an arrangement of the parts 21 is the one offering the best compactness on the plate 13, which makes it possible to optimize the manufacturing rate by manufacturing a large number of parts simultaneously.
[0055] The angle a formed between the direction of extension E of the blade 23 and the scraping direction X makes it possible to reduce the size of the contact zone C between the edge 25 of the blade 23 and the parts 21, thus reducing the mechanical stresses during the movement of the scraper 17.
Claims
Claims
1. Additive manufacturing device (1) comprising: - a manufacturing tray (13), intended to receive at least one powder (5), - a scraper (17) comprising a blade (23) extending in a horizontal plane (A) substantially parallel to the tray (13), the blade (23) being movable relative to the tray (13) in a scraping direction (X) substantially parallel to the tray (13), characterized in that the blade (23) comprises at least one portion extending locally in a local extension direction (E) forming a non-right angle (a) with the scraping direction (X) in the horizontal plane (A).
2. Device (1) according to claim 1, in which the blade (23) comprises at least one substantially rectilinear segment (25), extending in a direction of extension (E) forming a non-right angle (a) with the scraping direction (X) in the horizontal plane (A).
3. Device (1) according to claim 2 in which the direction of extension (E) of each segment (25) forms an angle (a) of amplitude between 85° and 89° with the scraping direction (X).
4. Device (1) according to one of the preceding claims, in which the blade (23) comprises at least two segments (25) elongated in respective elongation directions (E, E') forming non-right angles (a) with the scraping direction (X), the segments (25) forming at least one chevron.
5. Device (1) according to claim 1, in which the blade (23) has a curved profile in the horizontal plane (A).
6. Device (1) according to the preceding claim, in which the blade (23) has a sinusoidal profile in the horizontal plane (A).
7. Method for manufacturing at least one part (21), implementing a device (1) according to one of the preceding claims, the method comprising the following steps: - moving the blade (23) of the scraper (17) above the plate (13), in the scraping direction (X) and forming a layer of powder on the plate (13), - partial melting of a part of the layer of powder by means of a laser beam (19) and partial formation of each part (21), and - moving the blade (23) of the scraper (17) in the direction of scraping (X) and forming a new layer of powder above the partially formed parts (21), characterized in that the blade (23) comprises at least one portion extending locally in a direction of extent (E) forming a non-right angle (a) with the scraping direction (X) in the horizontal plane (A).
8. A method according to the preceding claim, wherein a plurality of parts (21) are manufactured simultaneously, the parts (21) being arranged aligned with side edges (29) of the parts (21) perpendicular to the scraping direction (X).