TECHNICAL FIELD

This invention concerns a method for creating by additive manufacturing an aircraft turbomachine vane, which may be part of an aircraft turbomachine distributor or rectifier sector.

BACKGROUND

The prior art comprises documents FR-A1-2 991 613, FR-A1-3 030 323, WO-A1-2012/001324, US-A1-2004/031780 and FR-A1-3 002 167.

A turbomachine distributor sector comprises two circumferential walls, upper and lower respectively, between which vanes extend comprising each a leading edge and a trailing edge extending between the walls. The leading edges of the vanes are located on the side of first circumferential edges of the walls and can be at least partially retracted with respect to these circumferential edges. Similarly, the trailing edges of the vanes are located on the side of the second circumferential edges of the walls and can be at least partially retracted with respect to these circumferential edges.

In the event that such a distributor sector is produced by additive manufacturing, by laser fusion on powder beds, the distributor would be produced on a support plate so that either the first circumferential edges or the second circumferential edges will be produced first directly on the support plate. In such a case, due to the above-mentioned retracting, there would be a gap between all or part of the leading or trailing edge of each vane and the support plate. To avoid such gap, which could lead to subsidence of the material during manufacture, it would be possible to use temporary vane support members. These members would be produced simultaneously with the first or second edges, at the level of the vanes, and would extend between the support plate and the leading or trailing edges of the vanes.

However, these support members should be eliminated after manufacture. This raises the question of their elimination, by the simplest possible technique, without any risk of damage to the vanes and of the distributor sector. A solution consisting in using a gripper to grasp each support member, disengaging it from the corresponding vane by back and forth movement, then removing it with the gripper, would be possible. However, the operator's gesture would not be precise and, because of the geometry of the member and its low stiffness, it could deform under the force applied by the gripper, making it more difficult to remove.

The invention offers a simple, effective and economical solution to at least some of these problems.

SUMMARY OF THE INVENTION

The invention proposes a method of creating at least one vane (i.e. any aerodynamic profile element) of an aircraft turbomachine, using additive manufacturing, this vane comprising two circumferential walls, upper and lower respectively, between which extend at least one vane comprising each a leading edge and a trailing edge extending between said walls and at least partially retracted with respect to first and second circumferential edges of said walls, respectively, the method comprising:an additive manufacturing step by laser fusion on powder beds of said vane, the manufacturing being carried out on a support plate so that said first or second circumferential edges are manufactured first directly on said support plate, at least one temporary support member being produced simultaneously with said first or second edges, at the level of said or each vane, and extending between said support plate and said leading or trailing edges of the vane, anda step of removing said or each supporting member by breaking its connection with the associated leading or trailing edge,

characterized in that the removing is carried out by means of a tool, at least one end of which is engaged in at least one recess of said or each supporting member, and which is moved by pivoting in a plane substantially perpendicular to the associated leading or trailing edge.

The invention can be applied to a single vane, i.e. isolated, or a series of vanes forming a monoblock assembly called a sector. The sector can be a rectifier sector (for a compressor) or a distributor sector (for a turbine).

The invention allows to solve the above-mentioned problem. It allows to stiffen the support member but also to make its removal operation easier, faster and also less constraining for the operator. One of the problems was the lack of rigidity, as the walls of the member could collapse under the action of the gripper. The presence and conformation of the recess allow to simplify the shape of the member, which is thus stiffened.

The process according to the invention may comprise one or more of the following characteristics or steps, taken in isolation from or in combination with each other:said tool is a screwdriver, preferably a flat end or head,each member comprises one to three recesses or more. The number of recesses depends, for example, on the contact surface between the support member and the vane,each member may comprise a main recess and two secondary recesses arranged on two opposite sides of the main recess,said main recess is delimited by walls thicker than those delimiting the secondary recesses; this allows the member to have sufficient strength when a removal force is applied,the method is applied to a series of vanes belonging to the same distributor or rectifier sector.

The present invention also concerns an aircraft turbomachine vane produced by the method described above, said vane comprising two circumferential walls, upper and lower respectively, between which extend at least one vane comprising each a leading edge and a trailing edge extending between said walls and at least partially retracted with respect to first and second circumferential edges of said walls respectively, at least one temporary support member being located at the level of the leading or trailing edge of said or each vane, and extending between a plane passing through said first or second edges and said leading or trailing edge of said or each vane, characterized in that said or each support member comprises at least one recess configured to receive at least one end of a tool, for pivoting removal of said member.

The vane according to the invention may comprise one or more of the following characteristics or steps, taken in isolation from each other or in combination with each other:each member comprises one to three or recesses or more,the or each recess is delimited by transverse reinforcing walls,each member has a thickness that varies between one end located on the side of the lower wall and an opposite end located on the side of the upper wall,each member comprises at least one lightening cavity; this type of cavity can also reduce the melting time and the powder consumption during the additive manufacturing,each lightening cavity is delimited by side walls of the member which comprise lightening notches,said lightening notches each have a general V-shape; this configuration can allow to facilitate the removal of powder from the cavities during a de-powdering operation at the end of the additive manufacturing operation; it can also allow to reduce the melting time and the powder consumption.

