AIRCRAFT PART COMPRISING A SELF-SUPPORTING CEILING SURFACE

Abstract

The invention relates to an aircraft part (100) comprising a body (102) having a surface (104) extending in first and second perpendicular directions (Z, X) and a platform (106) extending from the surface of the body, the platform (106) being delimited along the first direction by first and second surfaces (106A, 106B), the first surface (106A) extending from the surface of the body along an extension direction (DE) perpendicular to the second direction. According to the invention, the part includes a support (120) arranged between the surface (104) of the body (102) and the first surface (106A) of the platform (106), the support comprising several arches (130) configured to support the first surface of the platform, each arch (130) defining an open cavity (132) delimited by two opposing side walls (134A, 134B) along the second direction (X), and a vault wall (136) of the arch connected to the two side walls (134A, 134B).Figure for the abbreviation: Figure 3.

Description

Title of the invention: AIRCRAFT PART COMPRISING A SELF-SUPPORTING CEILING SURFACE technical field

[0001] The present invention relates to the aeronautical field. More particularly, the invention relates to a part for aircraft, especially turbomachinery, comprising a ceiling surface. Previous technique

[0002] Among aeronautical equipment, there are many parts with complex geometries, such as parts comprising cavities or fine channels running within said parts. It is also common for some parts to have walls inclined or perpendicular to a body of the part.

[0003] Today, it is known to use an additive manufacturing process called powder bed fusion to produce complex three-dimensional parts by fusing layers of material powder, such as the "laser beam melting" process, known by the English acronym LBM for "Laser Beam Melting". This process is also known as "selective laser melting" (or "SLM" for the English acronym "Selective Laser Melting").

[0004] Powder bed fusion refers to the addition of material layer by layer, on a build platform of a dedicated machine, to form a physical object from a digital model. In the case of a metal part, the laser melting process is used, which consists of melting a thin layer of powder material completely or partially using a laser with each pass.

[0005] However, the powder used is not self-supporting. Indeed, during the manufacturing of a part, the powder of lower layers that has not been scanned by the laser is unfused and is therefore not able to support the fused powder of a subsequent upper layer below a minimum draft angle between the part and the manufacturing platform or another part of the part.

[0006] Thus, powder bed additive manufacturing of parts with a so-called "overhead" surface is difficult. Such an overhead surface is a surface forming an angle less than the minimum draft angle as illustrated in [Fig. 1]. Arrow F indicates the direction of powder layer melting and therefore of part formation. Part 10 comprises a body 12 and an extension 14 extending from the body 12 in a substantially orthogonal direction. The extension 14 has a lower overhead surface 16, also classically called a "downskin" surface. In other words, it is an area that does not satisfy not the usual conditions for manufacturing it by additive manufacturing, namely a slope less than the minimum draft angle.

[0007] To address this issue, temporary supports 20 are typically formed during the manufacturing process of the part. These supports hold up each ceiling surface, i.e., each region with an angle less than the minimum draft angle, to prevent local collapse. The part 10 and the temporary supports 20 are integral, manufactured simultaneously, and made of the same material.

[0008] Once additive manufacturing is complete, the temporary supports constitute non-functional material and must therefore be removed, for example by adjustment or machining. For this purpose, these temporary supports are entirely honeycomb elements, generally in the form of lattices or resulting from the ordered stacking of structures, according to the Anglo-Saxon term "lattice." In this way, these temporary supports consume less powder while being more easily removed than a uniform block of material.

[0009] However, the removal of these temporary supports by adjustment or machining results in additional finishing costs for the part.

[0010] The objective of the present invention is therefore to overcome these drawbacks, in particular by eliminating these supports. Summary of the invention

[0011] To this end, the invention relates to an aircraft part comprising a body having a surface extending in a first direction and a second direction perpendicular to the first direction, and a platform extending from the surface of the body, the platform being delimited along the first direction by a first surface and a second surface, the first surface extending from the surface of the body in a direction of extension perpendicular to the second direction. According to the invention, the part advantageously comprises a support arranged between the surface of the body and the first surface of the platform, the support comprising several arches configured to support the first surface of the platform, each arch defining an open cavity delimited by two lateral walls of the arch, opposite along the second direction, and a vault wall of the arch connected to the two lateral walls.

[0012] The invention thus proposes a part capable of overcoming the aforementioned drawbacks.

[0013] Indeed, in order to avoid using temporary support for the first surface of the part, which is a ceiling surface as defined above, the part comprises several arches that can be manufactured by additive manufacturing and shaped to support said ceiling surface. Said ceiling surface is then self-supporting without requiring the creation and presence of a temporary support to be removed later.

[0014] The invention thus eliminates the need to remove these temporary supports by adjustment or machining. Consequently, the invention reduces or even eliminates the additional costs of finishing the part.

[0015] In addition, the design of these arches advantageously facilitates a numerical thickening of the part to take into account finishing processes such as a tribofinishing process or a chemical polishing process.

[0016] The part, according to the invention, may comprise one or more of the following features, taken individually or in combination with each other in all technically possible combinations: - the arches are distributed regularly along the surface of the body according to the second direction perpendicular to the first direction; - for each arch, the vault wall and the two side walls are connected to the surface of the body by a connecting fillet; - the support has several jambs, each jamb being delimited in the second direction by two lateral walls of two consecutive arches and each jamb being connected to the surface of the body by a rounded portion; - the surface of the body is flat and in which the lateral walls delimiting each leg are parallel; — the fillet connecting the surface of the body to the vault wall and to the two lateral walls of each arch has a constant radius. - the body of the part is cylindrical, and has a longitudinal axis parallel to the first direction and a circular section in a plane perpendicular to the longitudinal axis, and in which the lateral walls delimiting the same leg are parallel; — the fillet connecting the surface of the body to the vault wall and to the two lateral walls of each arch has a radius varying from each lateral wall to the vault wall; - the body of the piece is cylindrical, it has a longitudinal axis parallel to the first direction and a circular section in a plane perpendicular to the longitudinal axis, and the lateral walls delimiting the same arch are parallel; — the fillet connecting the surface of the body to the vault wall and to the two lateral walls of each arch has a constant radius; - the part is an air / water separator.

[0017] The invention also relates to an aircraft comprising a part according to the invention and as described above. Brief description of the drawings

[0018] The present invention will be better understood and other details, features and advantages of the present invention will become more apparent upon reading the following description of a non-limiting example, with reference to the accompanying drawings in which: - Fig. 1, already described, represents a schematic cross-sectional view of the manufacture of a part including a ceiling surface according to the prior art; - [Fig.2] is a perspective and schematic view of an additive manufacturing installation for producing a part according to the invention; - [Fig.3] is a schematic cross-sectional view of a part according to a first embodiment of the invention; - [Fig.4] is a schematic front view of the arches of the room in [Fig.2]; - [Fig. 5] is a schematic cross-sectional view of a part according to a second embodiment of the invention; - [Fig.6] is a schematic front view of the arches of the room in [Fig.5]; - Fig. 7 is a schematic cross-sectional view of a part according to a third method of implementing the invention; - [Fig.8] is a schematic front view of the arches of the room in [Fig.7].

[0019] Elements having the same functions in the different implementations have the same references in the figures.

[0020] In the figures, the scales and proportions are not strictly respected for the purposes of illustration and clarity. Description of the implementation methods

[0021] The present invention applies to any type of aeronautical part comprising at least one ceiling surface, as defined above and intended to equip a turbomachine or an aircraft.

[0022] Such a part according to the invention is advantageously obtained by additive manufacturing on a powder bed. According to the invention, the part 100 is monobloc, that is to say advantageously manufactured in continuous material.

[0023] As a reminder, the additive manufacturing process consists of creating complex three-dimensional parts by fusing layers of powder. Several additive manufacturing techniques are known: selective laser melting (SLM), electron beam melting (EBM), direct laser additive manufacturing (CLAD), and electron beam additive manufacturing (EBAM). Additive Manufacturing, according to Anglo-Saxon terminology, is laser metal deposition, abbreviated LMD for "Laser Metal Deposition" according to Anglo-Saxon terminology.

[0024] In particular, powder bed additive manufacturing is carried out using the selective laser melting (SLM) technique, which involves spreading powder layer by layer using a scraper that determines a set quantity and thickness of powder. A laser then fuses each layer of powder to form the part.

[0025] Powder bed fusion additive manufacturing of a part 100 according to the invention is carried out using an installation 200 as shown in [Fig. 2]. This installation is a selective laser melting (SLM) installation. The installation 200 comprises a first feed tank 202 containing a powder 204 of material and a build platform 206 on which the part 100 is manufactured. The installation 200 also includes a scanning element 208 for transferring a quantity of the powder 204 from the first feed tank 202 onto the build platform 206. The scanning element 208 also determines the quantity of powder and the powder thickness according to a control signal. Advantageously, but not exclusively, the build platform 206 is movable along a vertical translation Z within a second tank 210 and constitutes the movable bottom of this second tank 210.The first feed tank 202 also includes a movable bottom 212 that moves vertically upwards along the Z-axis as the powder 204 is transferred onto the build platform 206. The installation 200 also includes a laser beam generation element 214 for melting the powder intended for the part 100. This laser beam generation element 214 is coupled to means 216 for directing the laser beam 220, particularly towards the build platform 206. The means 216 for directing the laser beam 220 generated by the generation element 214 include first and second mirrors. The installation 200 further includes a third recycling tank 218 for recycling unused or unmelted powder.The process consists of manufacturing part 100 by layering powder from the first feed reservoir 202, which is transferred onto the manufacturing support 206. These powder layers are then melted one after another by means of the laser beam 220 moving over the surface of each layer to form part 100.

[0026] In order to avoid the use of temporary supports for the ceiling surface(s) of the part to be manufactured, such a part according to the invention will now be described with reference to figures 3 to X.

[0027] Fig. 3 illustrates a schematic cross-sectional representation of a part 100 according to the invention, the part being placed on the manufacturing support 206 of the additive manufacturing installation.

[0028] The part 100 comprises a body 102 having a surface 104.

[0029] The surface 104 extends in a first direction Z and a second direction X. The first direction Z and the second direction X are perpendicular.

[0030] During the additive manufacturing process, the part is oriented so that the first Z direction is vertical and corresponds to the direction of melting of the powder layers, the second X direction being horizontal.

[0031] The surface 104 of the body has a normal direction N, that is to say perpendicular to the surface 104. This normal direction is parallel to a third direction Y. The direction Y is perpendicular to the first and second directions Z, X. The directions X, Y and Z form a trihedron.

[0032] The part 100 further comprises a plate 106 extending from the surface 104 of the body 102 to a free end 106C.

[0033] More precisely, the plate 106 extends along the second direction X from the surface 104 between a first end and a second end.

[0034] The plate 106 is delimited along the first direction Z by a first surface 106A and a second surface 106B. The first surface 106A and the second surface 106B are connected at least by the free end 106C of the plate.

[0035] The first surface 106A extends from the surface 104 of the body 102 along an extension direction, denoted DE, perpendicular to the second direction X, to the free end 106C of the plate. The extension direction DE and the normal direction N, parallel to the third direction Y, form an angle α less than the minimum draft angle. The angle α between the extension direction DE and the normal direction N is preferably between 0 and 45°.

[0036] During the production of part 100 by additive manufacturing, the first surface 106A faces the manufacturing support 206 of the additive manufacturing installation.

[0037] Therefore, the first surface 106A will be called the "lower surface" or "ceiling surface" and the second surface 106B of the platform 106 will be called the "upper surface".

[0038] Usually, to manufacture such a surface in ceiling 106A, a temporary support as described above is used.

[0039] According to the invention, in order to do away with such a temporary support, the part 100 further includes a support 120 arranged between the surface 104 of the body 102 and the first surface 106A of the plate 106.

[0040] The support 120 comprises several arches 130 configured to support the first surface 106A of the platform. Figure 4 schematically represents the arches 130 of the support 120 from the front.

[0041] Thus, the support 120 has a surface opposite the ceiling surface 106A of the platform, called the upper surface 120B. The upper surface 120B of the support is attached to the ceiling surface 106A of the platform.

[0042] Each arch 130 advantageously defines an open cavity 132 allowing to limit the mass of the support and the quantity of powder necessary to make the support.

[0043] Each open cavity 132 is delimited by two lateral walls of the arch 134A, 134B, opposite along the second direction X, and a vault wall 136 of the arch connected to the two lateral walls 134A, 134B.

[0044] The support 120 has several legs 134.

[0045] Each jamb 134 is delimited along the second direction X by two lateral walls 134A, 134B of two consecutive arches 130.

[0046] In other words, the support 120 comprises an alternation of arches 136 and jambs 134 along the second direction X perpendicular to the first direction Z, vertical during the production of the part by additive manufacturing.

[0047] Furthermore, each leg 134 is delimited along the third direction Y, parallel to the normal N of the surface 104 of the body 102, by the surface 104 of the body 102 of the part and by a surface 134C. The surface 134C extends in a direction inclined with respect to the normal N of the surface 104 of the body 102 at an angle θ3 conforming to the rules of additive manufacturing, i.e., greater than the minimum draft angle. Preferably, the angle θ3 of inclination of the surface 134C of the legs is equal to 45° with respect to the surface of the build platform 206.

[0048] Each jamb 134, and more precisely each surface 134C, is advantageously connected to the surface 104 of the body 102 of the part by a rounded portion 134D.

[0049] The rounded portion 134D is convex. Preferably, the rounded portion 134D has a radius of approximately between 2 and 4 mm.

[0050] Each vault wall 136 extends along the extension direction DE of the ceiling surface 106A of the platform 106.

[0051] Advantageously, each vault wall 136 has a constant radius conforming to the rules of additive manufacturing so as not to require temporary support for its production by additive manufacturing. The radius is measured in a plane perpendicular to the extension direction DE.

[0052] Preferably, the radius of each vault wall is approximately equal to 2 mm.

[0053] The dimensions of the arches 130 of the support 120 allow them to be self-supporting during their production by additive manufacturing.

[0054] Each open cavity 132 is also delimited along the third direction Y, parallel to the normal N of the surface 104 of the body 102, by a bottom wall 132C. The bottom wall 132C is a portion of the surface 104 of the body 102 of the part 100. In other words, the bottom wall 132C thus connects the two lateral walls 134A, 134B.

[0055] For each arch 130, the vault wall 136 and the two side walls 134A, 134B are connected to the surface 104 of the body 102, i.e. to the bottom wall 132C, by a connecting fillet 138.

[0056] Advantageously, the arches 130 are distributed regularly along the surface 104 of the body in the second direction X between the first end and the second end of the plate 106.

[0057] The 130 arches are identical.

[0058] Fig. 4 represents in particular a first embodiment in which the surface 104 of the body (102) is flat.

[0059] Advantageously, according to this first embodiment, the side walls 134A, 134B delimiting the same jamb 134 are parallel. The side walls 134A, 134B thus extend along the first direction Z and also along the third direction Y.

[0060] According to this first embodiment, the fillet 138 connecting the arch wall 136 and the two side walls 134A, 134B to the surface 104 of the body 102, i.e., to the bottom wall 132C, has a constant radius. The radius of the fillet 138 depends on the final dimensions of the part.

[0061] This arch configuration makes it easier to digitally thicken the part to take into account chemical polishing.

[0062] Figures 5 and 6 illustrate a second embodiment in which the surface 104 of the body 102 is cylindrical. Indeed, according to this second embodiment, the body 102 of the part 100 is cylindrical. The body 102 has a longitudinal axis parallel to the first direction Z and a circular cross-section in a plane perpendicular to the longitudinal axis.

[0063] Fig. 5 is a cross-sectional view along the longitudinal axis of the body 102. Fig. 6 schematically represents a perspective view of three successive arches of the part 100.

[0064] According to this second embodiment, the lateral walls 134A, 134B delimiting the same jamb 134 are parallel. A first median plane PI is thus defined between the two lateral walls 134A, 134B of a jamb; this first median plane PI extends along the first direction Z and also along the third direction, which is radial here, denoted R, that is to say, perpendicular to the longitudinal axis of the body 102. The second direction is circumferential here, denoted C.

[0065] According to this second embodiment, the connecting fillet 138 connecting the surface 104 of the body 102 to the vault wall 136 and to the two lateral walls 134A, 134B of each arch 130 has a radius varying from each lateral wall 134A, 134B to the vault wall 136.

[0066] In the illustrated example, the radius of the connecting fillet 138 increases from the rounded portion 134D of each jamb 134 towards the vault wall 136.

[0067] Figures 7 and 8 illustrate a third embodiment in which the surface 104 of the body 102 is cylindrical. Indeed, according to this third embodiment, the body 102 of the part 100 is cylindrical. The body 102 has a longitudinal axis parallel to the first direction Z and a circular cross-section in a plane perpendicular to the longitudinal axis.

[0068] Fig. 7 is a cross-sectional view along the longitudinal axis of the body 102. Fig. 8 schematically represents a perspective view of several successive arches of the part 100.

[0069] This third embodiment differs from the second embodiment in that the lateral walls 134A, 134B delimiting the same arch 130 are parallel. A second median plane P2 is thus defined between the two lateral walls 134A, 134B of an arch; this median plane P2 extends along the first direction Z and also along the third direction, which is radial here, denoted R, that is, perpendicular to the longitudinal axis of the body 102. The second direction is circumferential here, denoted C.

[0070] According to this third embodiment, the connecting fillet 138 connecting the surface 104 of the body 102 to the vault wall 136 and to the two lateral walls 134A, 134B of each arch 130 has a constant radius from each lateral wall 134A, 134B to the vault wall 136.

[0071] This arch configuration makes it easier to digitally thicken the part to take into account chemical polishing.

[0072] The present invention applies to any type of aeronautical part comprising one or more ceiling surfaces and obtained by additive manufacturing and intended to equip a turbomachine or an aircraft.

[0073] This is particularly the case for a water separator used to separate water from air in a turbomachine or aircraft.

[0074] The parts according to the invention thus comprise self-supporting ceiling surfaces which make it easy to manufacture them without temporary supports that need to be removed at the end of the additive manufacturing process. The invention therefore avoids additional finishing costs.

[0075] The configuration of the arches can advantageously facilitate a numerical thickening of the part to take into account chemical polishing.

[0076] Naturally, the invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different embodiments of the invention without departing from the scope of the invention.

[0077] It is emphasized that all features, as they are apparent to a person skilled in the art from the present description, drawings and attached claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, may be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances make such combinations impossible or meaningless.

Claims

Demands

1. Aircraft part (100) comprising a body (102) having a surface (104) extending in a first direction (Z) and a second direction (X) perpendicular to the first direction, and a platform (106) extending from the surface (104) of the body (102), the platform (106) being delimited along the first direction (Z) by a first surface (106A) and a second surface (106B), the first surface (106A) extending from the surface (104) of the body along an extension direction (DE) perpendicular to the second direction (X), the part being characterized in that it comprises a support (120) arranged between the surface (104) of the body (102) and the first surface (106A) of the platform (106), the support (120) comprising several arches (130) configured to support the first surface (106A) of the plateau (106), each arch (130) defining an open cavity (132) delimited by two lateral walls (134A, 134B) of the arch,opposite along the second direction (X), and a vault wall (136) of the arch connected to the two lateral walls (134A, 134B).

2. Part according to claim 1, wherein the arches (130) are distributed regularly along the surface of the body in the second direction (X) perpendicular to the first direction.

3. Part according to claim 1 or 2, in which for each arch (130), the vault wall (136) and the two side walls (134A, 134B) are connected to the surface (104) of the body (102) by a connecting fillet (138).

4. Part according to any one of the preceding claims, wherein the support (120) has several legs (134), each leg being delimited along the second direction (X) by two lateral walls (134A, 134B) of two consecutive arches (130) and each leg (134) being connected to the surface (104) of the body (102) by a rounded portion (134D).

5. Part according to any one of claims 3 or 4, wherein the surface (104) of the body (102) is flat and wherein the side walls (134A, 134B) delimiting each jamb (134) are parallel.

6. A part according to any one of claims 3 or 4, wherein the body (102) of the part (102) is cylindrical, it has an axis

7.

8.

9. longitudinal parallel to the first direction (Z) and a circular section in a plane perpendicular to the longitudinal axis, and in which the lateral walls (134A, 134B) delimiting the same jamb (134) are parallel. Part according to any one of claims 3 or 4, wherein the body (102) of the part (100) is cylindrical, it has a longitudinal axis parallel to the first direction and a circular section in a plane perpendicular to the longitudinal axis, and wherein the lateral walls (134A, 134B) delimiting the same arch (130) are parallel. Part according to any one of claims 6 or 7, the part being an air / water separator. Aircraft comprising at least one part according to any one of the preceding claims.

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