Assembly cup, assembly and assembly process

Abstract

An assembly cup (4) for joining a first part (1) and a second part (2) comprising a cup orifice (OR4), a support wall (41) having an upper edge (42) extending in a principal plane (P4), the principal plane (P4) being inclined with respect to the cup axis (X4) at a principal angle (α) strictly less than 90° in a plane in section along the cup axis (X4). Abstract figure: Figure 5

Description

Title of the invention: Assembly cup, assembly and assembly method. Technical field

[0001] The present invention relates to the field of machines such as aircraft turbomachinery, and more particularly to the assembly of two parts intended to be part of such a machine.

[0002] An aircraft turbomachine generally comprises relatively thin-walled parts to which other parts are attached by means of fasteners. These relatively thin parts are, for example, sectors mounted end-to-end circumferentially to form an outer ring of an intermediate housing hub, internally delimiting the secondary flow channel of the turbomachine, and / or an inner ring of such an intermediate housing hub, externally delimiting the primary flow channel of the turbomachine. Components housed in a defined space between the two aforementioned rings are in fact attached to one or the other of the rings. The components attached to these relatively thin parts are, for example, air or oil supply ducts. Furthermore, the relatively thin walls are themselves generally attached to housings, also by means of fasteners.

[0003] Figure 1 schematically illustrates a first, relatively thin part 1, such as a ferrule sector of the type described above, to which a second part 2 is fixed. For this purpose, the first part 1 and the second part 2 are provided respectively with a through hole OR1 and a through hole OR2 positioned opposite each other, through which extends a fixing screw 3 comprising a head 31 and a body 32, which is screwed into a threaded hole in the second part 2. The first part 1 defines a recess 11 for the head 31 of the screw 3. This prevents the head 31 of the fixing screw 3 from protruding outwards from the first part 1.

[0004] In practice, to avoid the transmission of mechanical forces between the first part 1 and the fastener 3, it is known to provide an assembly cup 104 mounted at the interface between the housing 11 and the screw head 31. The assembly cup 104 has a bearing wall 141 configured to cooperate with the head 31. The assembly cup 104 is in the form of an axisymmetric frustoconical part having a cup axis XI04 and a cup orifice OR104. Such an assembly cup 104 is particularly advantageous when the first part 1 is made of composite material.

[0005] In a known manner, with reference to [Fig. 2], in order to prevent the assembly cup from being drawn towards the second part 2 during the installation of the fastener 3, it has been proposed to use an assembly cup 204, having a cup axis X204 and a cup orifice OR204, comprising a bearing wall 241 configured to cooperate with the head 31 of the fastener 3 and a flange 242 configured to bear against an upper surface 10 of the first part 1 as illustrated in [Fig. 2]. In [Fig. 2], the upper surface 10 belongs to a first plane PI.

[0006] With reference to [Fig. 3], when the upper surface 10 of the first part 1 is not orthogonal to the axis of the cup X204, the collar 242 forms a step D at the level of the upper surface 10 of the first part 1, which induces turbulence and affects the aerodynamic behavior. An immediate solution would be to remove the collar, but this increases the risk of undesired displacement as previously indicated.

[0007] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0008] The invention relates to an assembly cup, in particular for a machine such as an aircraft turbomachine, configured to assemble a first part comprising a through-hole and a second part comprising a through-hole positioned opposite the through-hole of the first part, by means of a fastening member extending through the through-holes, which has a head bearing against the first part and a body cooperating with the second part so as to secure the second part to the first part, the assembly cup being configured to be mounted in the through-hole of the first part, the assembly cup comprising: • a cup orifice configured to house the head of the fastening member and through which the body of the fastening member extends, the cup orifice extending along a cup axis; • a supporting wall against which the head of the fastening element is configured to bear, the supporting wall having an upper edge extending in a principal plane,

[0009] The assembly cup is remarkable in that, in a cross-sectional plane along the cup axis, the principal plane is inclined with respect to the cup axis by a principal angle strictly less than 90°.

[0010] A joining cup with such an upper edge is not symmetrical about the cup axis, which is contrary to the practices of a person skilled in the art. The joining cup allows assembly to be carried out without generating aerodynamic disturbances while ensuring optimal attachment with a fastening element.

[0011] In one aspect, the principal angle is less than 85°. In another aspect, the principal angle is greater than 40°, preferably greater than 60°. This advantageously allows adaptation to upper walls inclined with respect to a longitudinal axis of a turbomachine.

[0012] According to one aspect, the assembly cup includes a collar connected to the upper edge of the support wall. Such a collar reduces the risk of unintentional displacement of the assembly cup during assembly.

[0013] According to one aspect, the collar is flat and extends in the principal plane. Such a collar ensures a flat support.

[0014] According to one aspect, the collar is of the umbrella type and allows to offer elasticity and support according to its free edge.

[0015] According to one aspect, the assembly cup includes at least one angular indexing element configured to angularly orient the assembly cup during assembly. This allows for optimal orientation of the assembly cup, which is not symmetrical.

[0016] An assembly is also presented, in particular for a machine such as an aircraft turbomachine, comprising: • a first part comprising a through-hole and a second part comprising a through-hole positioned opposite the through-hole of the first part, • a fastening element extending through the through holes, which has a head exerting pressure on the first part and a body cooperating with the second part so as to ensure that the second part is fixed to the first part, • an assembly cup, as previously presented, being mounted in the through orifice of the first part, the body of the fastener extending through the cup orifice, the head of the fastener bearing against the support wall, the upper edge extending in the aerodynamic continuation of the first part.

[0017] A method for assembling, in particular for a machine such as an aircraft turbomachine, a first part comprising a through-hole and a second part comprising a through-hole positioned opposite the through-hole of the first part is also presented, the method comprising steps consisting of: • Position an assembly cup, as previously shown, in the through-hole of the first part, with the upper edge extending in the aerodynamic line of the first part, • Insert a fastener through the through holes so as to secure the second part to the first part, the fastener comprising a body, extending through the cup hole, and a head, bearing against the support wall of said assembly cup.

[0018] Preferably, the method includes a step of angularly orienting the assembly cup so that the upper edge extends in the aerodynamic continuation of the first part.

[0019] Also presented is a machine, in particular a turbomachine, comprising at least one assembly as previously presented, in which one of the first and second parts constitutes at least part of an annular wall delimiting a flow channel of the machine. PRESENTATION OF THE FIGURES

[0020] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0021] Fig. 1 is a partial schematic axial cross-sectional representation of an assembly with a first assembly cup according to the prior art.

[0022] Fig. 2 is a partial schematic axial cross-sectional representation of a second assembly cup according to the prior art.

[0023] Fig. 3 is a partial schematic axial cross-sectional representation of a second assembly cup according to the prior art with a first piece having an inclined upper surface.

[0024] Fig. 4 is a schematic axial cross-sectional representation of a turbomachine.

[0025] Figure 5 is a partial schematic axial cross-sectional representation of a assembly cup according to a first form of realization.

[0026] The [Fig.6] is a partial schematic axial sectional representation of an assembly cup according to a second embodiment.

[0027] The [Fig.7] is a partial schematic axial sectional representation of an assembly cup according to a third embodiment.

[0028] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0029] With reference to [Fig. 4], a turbomachine T for an aircraft, for example a turbofan engine, is shown extending axially along a turbomachine axis X. The turbomachine T generally comprises a fan configured to drive an upstream to downstream airflow, which divides downstream of the fan into a primary flow feeding a primary duct VI and a secondary flow feeding a secondary duct V2 to generate propulsive thrust. The turbomachine T includes, in the primary duct VI, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, and a low-pressure turbine. The turbomachine T is enclosed by a nacelle that externally delimits the secondary duct V2. The invention is presented for a turbofan-type turbomachine T, but it also applies to an open-rotor turbomachine T.

[0030] In this example, the turbomachine T includes, in particular, mechanical parts 1, 2, in particular in the form of relatively thin walls, which are assembled by fasteners, in particular, screws or rivets. These include sectors mounted end-to-end circumferentially to form the outer shell of an intermediate housing hub, internally delimiting the secondary flow V2, and sectors mounted end-to-end circumferentially to form the inner shell of such an intermediate housing hub, this shell externally delimiting the primary flow VL

[0031] With reference to [Fig.6], an assembly 5 is shown comprising a first part 1 including a through orifice OR1 and a second part 2 including a through orifice OR2 positioned opposite the through orifice OR1 of the first part 1.

[0032] In this example, the first part 1 is, for example, a section of the outer shell, and the second part 2 is, for example, a wall of an air or oil supply duct. Alternatively, the second part 2 could, in particular, be part of a structural arm of an intermediate housing. It goes without saying that parts 1 and 2 could be various mechanical parts of the turbomachine T. According to one aspect, at least one of the parts is a part made of composite material, preferably the first part 1.

[0033] The assembly 5 further comprises a fastening member 3 extending through the through holes OR1, OR2, which has a head 31 bearing against the first part 1 and a body 32 cooperating with the second part 2 so as to secure the second part 2 to the first part 1. The fastening member 3 may be in various forms, in particular, a rivet or a screw. For a screw, the screw body preferably has a thread, and the second part 2 has a tapped hole configured to cooperate with the thread.

[0034] In this example, the through-hole OR1 of the first part 1 extends along an axis of the first part XI, and the upper surface 10 of the first part 1 extends in a first plane PI that is not orthogonal to the axis of the first part XI. Preferably, the first plane PI is defined locally in the vicinity of the housing 11. The upper surface 10 is inclined, which is typical for forming a vein VI, V2 whose cross-section is variable. The first part 1 has a housing 11 for receiving the head 31 of the fastening member 3, the through-hole OR1 being formed in the housing 11.

[0035] According to the invention, the assembly 5 comprises an assembly cup 4 mounted in the housing 11 of the first part 1.

[0036] With reference to figures 5 to 7, the assembly cup 4 includes a cup orifice OR4 through which the body 32 of the fastening member 3 extends, the cup orifice OR4 extending along a cup axis X4.

[0037] The assembly cup 4 is preferably in the form of a single piece, in particular, made of stainless steel, for example Z6CNT18.

[0038] The assembly cup 4 comprises a bearing wall 41 defining a lower surface configured to bear against the housing 11 of the first part 1 and an outer surface on which the head 31 of the fastener 3 is configured to bear. The bearing wall 41 is preferably in the form of a portion of a cone.

[0039] With reference to Figures 5 to 7, the support wall 41 includes an upper edge 42 extending in a principal plane P4. The assembly cup 4 is notable in that, in a cross-sectional view along the cup axis X4, the principal plane P4 is inclined with respect to the cup axis X4 at a principal angle α strictly less than 90°. Preferably, the principal angle α is less than 85°. In one aspect, the principal angle α is greater than 40°, preferably greater than 60°. The principal angle α corresponds to the minimum angle formed between the cup axis X4 and the principal plane P4.

[0040] Such an upper edge 42 is thus inclined relative to a traditional upper edge which extends in a plane at 90° to the cup axis X4. This advantageously allows following the inclination of the upper surface 10 of the first part 1 as will be shown later in order to improve the aerodynamic behavior in the air ducts VI, V2 of the turbomachine T by aligning the first plane PI and the main plane P4.

[0041] Cleverly, the assembly cup 4 does not have a symmetrical support wall with respect to its cup axis X4, which goes against the general practices of a person skilled in the art.

[0042] According to one aspect, with reference to Figures 5 to 7, the assembly cup 4 comprises a flange 43, 44 connected to the upper edge 42 of the support wall 41. The flange 43, 44 is configured to bear against the upper surface 10 of the first part 1 at a distance from the housing 11 of the first part 1. Such a flange 43, 44 prevents the assembly cup 4 from being drawn towards the second part 2 during assembly 5. The flange 43, 44 extends projecting from the upper edge 42 and has a free edge 45, preferably circumferential, intended to bear against the upper surface 10 of the first part 1. Advantageously, the free edge 45 extends in the principal plane P4 so as to cooperate with the upper surface 10 of the first part 1 in the foreground PL

[0043] According to a first variant, with reference to [Fig.5], the collar 43 is flat and extends in the principal plane P4. This allows the collar 43 to provide continuous and flat support on the upper surface 10.

[0044] According to a second variant, with reference to [Fig. 6], the collar 44 is of the umbrella type. The collar 44 rests on the upper surface 10 only along the free edge 45. The collar 44 has a concave shape, the concavity of which is turned towards the first part 1 as illustrated in [Fig. 6].

[0045] According to one aspect, with reference to [Fig. 7], the assembly cup 4 comprises at least one angular indexing member 46 configured to angularly orient the assembly cup 4. In other words, the angular indexing member 46 performs an angular error-proofing function. This is particularly convenient for operators since the assembly cup 4 is no longer axisymmetric as in the prior art.

[0046] In this example, the angular indexing member 46 is in the form of a notch formed in the free edge 45 of the flange 43, 44. Preferably, the angular indexing member 46 is configured to be positioned on an upstream-to-downstream axis with the angular indexing member 46 oriented towards the downstream side. Optionally, the upper wall 10 could include a complementary indexing element (not shown), such as a marking, to align it with the angular indexing member 46 so as to ensure optimal angular orientation of the assembly cup 4 in order to reduce aerodynamic disturbances.

[0047] An example of the implementation of an assembly process will now be presented. The through holes OR1, OR2 of parts 1, 2 are aligned.

[0048] The method includes a step of positioning the assembly cup 4 in the through hole OR1 of the first part 1. The lower surface of the support wall 41 is in contact with the housing 11 of the first part 1. In such a way preferred, the collar 43, 44 prohibits any movement of the assembly cup 4 towards the second part 2.

[0049] Preferably, the method includes a step of angularly orienting the assembly cup 4 so that the principal plane P4 is parallel to the first plane PI in which the first part 1 extends. Advantageously, the angular indexing member 46 can be used by the operator to achieve a precise angular orientation.

[0050] Following the positioning, the upper edge 42 of the support wall 41 extends in the main plane P4 which is parallel to the first plane PI in which the first part 1 extends. This helps to limit aerodynamic disturbances.

[0051] The method then includes a step of inserting a fastening member 3 through the through holes OR1, OR2 of the parts 1, 2 so as to ensure a fastening of the second part 2 on the first part 1. The body 32 of the fastening member 3 extends through the cup hole OR4, the head 31 of the fastening member 3 being in contact with the support wall 41, the upper edge 42 extending in the aerodynamic continuation of the first part 1.

[0052] Thanks to the invention, the assembly 5 is perfectly suited for an inclined upper surface 10. The aerodynamic turbulence associated with the assembly 5 is reduced, which is advantageous for forming an air stream VI, V2 of a turbomachine T whose cross-section varies along the X-axis of the turbomachine T.

Claims

Demands

1. Assembly cup (4), in particular for a machine such as an aircraft turbomachine (T), configured to assemble a first part (1) comprising a through-hole (OR1) and a second part (2) comprising a through-hole (OR2) positioned opposite the through-hole (OR1) of the first part (1), by means of a fastening member (3) extending through the through-holes (OR1, OR2), which has a head (31) bearing against the first part (1) and a body (32) cooperating with the second part (2) so as to secure the second part (2) to the first part (1), the assembly cup (4) being configured to be mounted in the through-hole (OR1) of the first part (1), the assembly cup (4) comprising: • a cup opening (OR4) configured to house the head (31) of the member of fixation (3) and through which extends the body (32) of the fixation member (3),• the cup orifice (OR4) extending along a cup axis (X4); • a support wall (41) on which the head (31) of the fastener (3) is configured to bear, the support wall (41) having an upper edge (42) extending in a principal plane (P4); • assembly cup (4) characterized in that, in a cross-sectional plane along the cup axis (X4), the principal plane (P4) is inclined with respect to the cup axis (X4) at a principal angle (a) strictly less than 90°.

2. Assembly cup (4) according to claim 1, wherein the principal angle (a) is less than 85°.

3. Assembly cup (4) according to any one of claims 1 to 2, wherein the principal angle (a) is greater than 40°.

4. Assembly cup (4) according to any one of claims 1 to 3, wherein the assembly cup (4) comprises a collar (43, 44) connected to the upper edge (42) of the support wall (41).

5. Assembly cup (4) according to claim 4, wherein the collar (43) is flat and extends in the principal plane (P4).

6. Assembly cup (4) according to claim 4, wherein the collar (44) is of the umbrella type.

7. Assembly cup (4) according to any one of claims 1 to 6, comprising at least one angular indexing member (46) configured to angularly orient the assembly cup (4) during assembly.

8. Assembly (5), in particular for a machine such as an aircraft turbomachine (T), comprising: • a first part (1) having a through-hole (OR1) and a second part (2) having a through-hole (OR2) positioned opposite the through-hole (OR1) of the first part (1), • a fastening member (3) extending through the through-holes (OR1, OR2) having a head (31) bearing against the first part (1) and a body (32) cooperating with the second part (2) so as to secure the second part (2) to the first part (1), • an assembly cup (4) according to any one of claims 1 to 7 being mounted in the through-hole (OR1) of the first part (1), the body (32) of the fastening member (3) extending through the cup orifice (OR4), the head (31) of the fastening member (3) being supported on the supporting wall (41),the upper edge (42) extending in the aerodynamic continuation of the first part (1).

9. A method for assembling, in particular for a machine such as an aircraft turbomachine (T), a first part (1) comprising a through-hole (OR1) and a second part (2) comprising a through-hole (OR2) positioned opposite the through-hole (OR1) of the first part (1), the method comprising steps of: • Positioning an assembly cup (4) according to any one of claims 1 to 7 in the through-hole (OR1) of the first part (1), the upper edge (42) extending in the aerodynamic continuation of the first part (1), • Inserting a fastening member (3) through the through-holes (OR1, OR2) so as to secure the second part (2) to the first part (1), the fastening member (3) comprising a body (32) extending

10. through the cup orifice (OR4), and a head (31), bearing on the bearing wall (41) of said assembly cup (4). Assembly method according to claim 9, wherein the method includes a step of angularly orienting the assembly cup (4) so ​​that the upper edge (42) extends in the aerodynamic continuation of the first part (1).

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