EP3183498B1 - Connection device comprising several curved concentric tubes - Google Patents

Description

TECHNICAL AREA

The invention relates to a device making the connection of a turbomachine member, such as an injector of an aircraft turbomachine, with a fuel supply system.

The invention relates more particularly to a connection device comprising several concentric tubes bent identically.

STATE OF THE PRIOR ART

An aircraft turbomachine comprises in particular a fuel supply system comprising an injector the purpose of which is to inject a certain quantity of fuel into the combustion chamber of the turbomachine. The quantity of fuel injected depends on the operating conditions of the turbomachine.

An injector, in particular of the aeromechanical type, comprises a first outlet, called primary, which is used during a starting phase of the turbomachine and a second outlet, called secondary, which is used after starting the turbomachine, and by which a large fuel flow is supplied.

The fuel system supplies several different fuel streams to the injector. Each of these different streams is associated with and supplies an output of the injector, that is to say a primary stream supplying the primary output, and a secondary stream supplying the secondary output.

A connection device is arranged between the injector and the supply system, to lead the various fuel flows through small spaces.

Due to the small space available for the routing of the fuel flows, the connection device comprises several concentric tubes which delimit several conduits through which the fuel flows circulate.

In general, a connection device comprises three tubes which define three concentric conduits. A first central duct is associated with the primary flow, a second radially intermediate duct is associated with the secondary flow and a third radially outer duct is associated with a fuel flow providing thermal protection of the primary and secondary fuel flows.

The tubes of the connection device are curved, or bent, to allow access to the location of the associated injector, taking into account the constraints of integration on the turbomachine.

According to a conventional manufacturing method, the tubes are bent simultaneously.

For this, helical springs are installed between the tubes, to keep the tubes at a distance from each other during bending operations.

However, it results from these bending operations that the thickness of the tubes is not constant over their entire length, manufacturing dispersions or else sealing problems.

The object of the invention is to provide a connection device making it possible to solve these problems.

US 2003/0182945 A1 shows a fuel injector for a turbomachine comprising two concentric tubes supplying the injector with fuel, the radially inner tube comprising longitudinal fins extending radially to the radially outer tube. These two concentric tubes extend inside a third concentric tube serving as a support for the injector and thermal protection for the concentric tubes.

US 2011/0247590 A1 and US 2009/0255602 A1 show fuel injectors for a turbomachine whose feed devices are made in one piece using a direct metal laser melting process.

DISCLOSURE OF THE INVENTION

The invention proposes a device for connecting an organ to a system for supplying the organ with fluid, the connecting device comprising three concentric tubes delimiting supply ducts for the organ, which are bent along at least a direction, in which the connection device is made in one piece comprising at least the tubes, the connection device further comprising two sets of radial ribs, the radial ribs of a first set of ribs connecting the outer surface of the radially inner tube to the inner surface of the radially intermediate tube and the radial ribs of the second set of ribs connecting the outer surface of the radially intermediate tube to the inner surface of the radially intermediate tube external, the radial ribs between two adjacent tubes extending along the central curve of the tubes over the entire length of said adjacent tubes and being made in one piece with said adjacent tubes.

Preferably, fillets are formed at each radial end of each rib, at the level of the connection of said radial end of the rib with the facing wall of an associated tube.

Preferably, the connection device comprises a body for connecting the tubes with a fluid injection system, and said body is made in one piece with the tubes and the ribs.

Preferably, the body has a mounting plate and fillets are formed at the connection between the outer surface of the radially outer tube and each surface of the plate.

Preferably, the connection device is produced by implementing a direct laser metal melting process.

The invention also relates to a fluid supply circuit for a turbomachine member such as a fuel injector for an aircraft turbomachine combustion chamber comprising a connection device according to the invention.

The invention also relates to an aircraft turbomachine comprising at least one member connected to a system for supplying the member with fluid by a connection device according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une représentation schématique en perspective d'un circuit d'alimentation en carburant d'un injecteur comportant un dispositif de raccordement selon l'invention ;
• la figure 2 est une vue en coupe radiale du dispositif de raccordement montrant les différents tubes et les nervures radiales ; et
• la figure 3 est une vue en coupe axiale du dispositif de raccordement montrant le corps du dispositif de raccordement avec les tubes.

Other characteristics and advantages of the invention will become apparent on reading the detailed description which follows, for the understanding of which reference is made to the appended figures, among which:

• the figure 1 is a schematic perspective representation of a fuel supply circuit for an injector comprising a connection device according to the invention;
• the figure 2 is a radial sectional view of the connecting device showing the various tubes and the radial ribs; and
• the figure 3 is an axial sectional view of the connection device showing the body of the connection device with the tubes.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

We have represented at the figure 1 a circuit 10 for supplying fuel to a fuel injector (not shown) for an aircraft turbomachine combustion chamber.

This injector is designed to be able to selectively inject two separate streams of fuel. These fuel flows are a primary flow, which is injected during a start-up phase of the turbomachine and which is not very significant, and a larger secondary flow, which is injected when the turbomachine is in operation.

The specificities of each of the two fuel flows being different, these two flows are consequently separated as much at the level of the outlet of the injector as in the entire supply circuit 10.

The supply circuit 10 also comprises a supply system 12 which distributes a single flow of fuel coming from a high pressure pump, into several different flows supplying the injector, and regulates the pressure and the flow rate of each of these. fuel flow.

The supply system 12 is connected to the injector by means of a connection device 14.

This connection device 14 comprises a body 16 which is connected to the supply system 12 and a pipe 18 extending from the body 16 to the injector.

The pipe 18 is shaped to circulate the various fuel flows in the direction of the injector. For this, the pipe 18 is divided into several concentric supply conduits 20, 22, 24, here three in number as can be seen in more detail at figure 2 .

The line 18 comprises a first radially internal duct 20 which is associated with the first fuel flow, a second radially intermediate duct 22 which is associated with the second fuel flow and a third radially external duct 24 which is associated with a stagnant fuel flow acting as a heat shield. The purpose of this stagnant fuel in the third pipe 24 is to protect the other two fuel streams from heat, and thus in particular to avoid fuel coking phenomena inside the fuel injector.

The pipe 18 consists of several concentric tubes 26, 28, 30, three in number, which delimit the conduits 20, 22, 24. The first conduit 20 is thus delimited by the radially internal tube 26, the second conduit 22 is delimited by the radially inner tube 26 and the intermediate tube 28 and the third conduit 24 is delimited by the intermediate tube 28 and the radially outer tube 30.

The tubes 26, 28, 30 are connected to the body 16 of the connecting device 14.

The pipe 18 is curved, to allow the integration of the connection device on the turbomachine, taking into account the other components of the turbomachine located nearby. Consequently, the concentric tubes 26, 28, 30 are also bent in at least one direction.

The pipe 18 also comprises means for maintaining the tubes 26, 28, 30 at a distance from each other, which consist of a plurality of radial ribs 32.

Each rib 32 is bent identically to the pipe 18, that is to say it extends radially and along the central curve of the pipe 18 and the tubes 26, 28, 30, over the entire length. length of tubes 26, 28, 30.

The ribs 32 are located in the second duct 22 and in the third duct 24, thus forming two sets of ribs, the ribs 32 of the first set of ribs extending into the second duct 22, the ribs 32 of the second set of ribs 32 extending into the third duct 24.

Here, each set of ribs has four ribs 32 distributed at 90 degrees. It will be understood that a set of ribs may include a different number of ribs 32 without departing from the invention.

Also, the ribs 32 of the two sets of ribs are disposed around the central curve of the pipe 18 with two adjacent ribs 32 aligned.

According to the embodiment shown in the figures, the ribs 32 are all of the same thickness. According to an alternative embodiment, certain ribs 32 have a different thickness from the thickness of the other ribs 32, in order to locally modify the mechanical resistance to the pipe 18. Also, the thickness of a rib can vary along the central curve. of the pipeline 18.

Each radial end of each rib 32 comprises a surplus of material forming a fillet 34 at its connection with the associated face of a tube 26, 28, 30. The purpose of these fillets 34 is to eliminate the sharp edges that may locally weaken the connection. between a rib and the wall facing a tube 26, 28, 30.

The body 16 of the connection device 14 comprises a cylindrical part 36 which is intended to receive a complementary part of the supply system 12 and which communicates separately with each of the conduits 20, 22, 24.

The body 16 comprises a mounting plate 38 for the connection device 14 on the turbomachine. This fixing plate 38 extends around the radially outer tube 30 and fillets 40 are formed at the connection between the fixing plate 38 and the outer tube 30.

Preferably, the tubes 26, 28, 30 are all made from a single piece of the same material.

According to another aspect of the connection device 14, the ribs 32 are made in one piece with the tubes 26, 28, 30.

According to yet another aspect of the connection device 14, the body 16 of the connection device is made in one piece with the tubes 26, 28, 30 and the ribs 32.

Thus, according to a preferred embodiment of the invention, the entire connection device 14 is made in one piece.

According to a preferred embodiment, the connection device 14 is produced by implementing a so-called direct laser metal melting process. Such a method consists in distributing a uniform layer of metal powder by means of a re-coating device, then in melting this layer at given locations corresponding to a section of the connecting device in a very controlled inert atmosphere. These operations are repeated several times until the connection device 14. Once completed, the connection device 14 is removed from the powder bed and subjected to heat treatment and finishing.

Thus, the connection device 14 does not undergo any shaping step which would be complex to implement and would risk weakening it locally.

All the parts of the connection device 14 are made from a single material which is for example a Cobalt Chromium Molybdenum alloy or an alloy known under the name Inconel 718.

Such an embodiment of the connection device 14 has the additional advantage that no sealing means is necessary between the different tubes 26, 28, 30 and the body 16 of the connection device, thus reducing the risk of leaks. fuel or accidental connection of two conduits 20, 22, 24.

Also, the strength of the connection device 14 is improved since it is possible to adapt the thickness of a tube 26, 28, 30 or of a rib 32 as a function of the stresses that it is subjected to.

Claims (7)

1. A connection device (14) for connecting a member to a system for supplying the member with fluid, the connection device (14) including three concentric tubes (26, 28, 30) delimiting conduits (20, 22, 24) for supplying the member, which are curved along at least one direction,
   wherein the connection (14) device is made as a single piece including at least the tubes (26, 28, 30),
   the connection device (14) further two sets of radial ribs (32), the radial ribs (32) of a first set of ribs (32) connecting the outer surface of the radially inner tube (26) to the inner surface of the radially intermediate tube (28) and the radial ribs (32) of the second set of ribs (32) connecting the outer surface of the radially intermediate tube (28) to the inner surface of the radially outer tube (30),
   the radial ribs (32) between two adjacent tubes (26, 28, 30) extending along the central curve of the tubes (26, 28, 30) over the entire length of said adjacent tubes (26, 28, 30) and being made as a single piece with said adjacent tubes (26, 28, 30).
2. The connection device (14) according to claim 1, wherein fillets (34) are formed at each radial end of each rib (32), at the connection of said radial end of the rib (32) with the facing wall of an associated tube (26, 28, 30).
3. The connection device (14) according to any of the preceding claims, including a body (16) for connecting the tubes (26, 28, 30) with a fluid injecting system, said body (16) being made as a single piece with the tubes (26, 28, 30) and the ribs (32).
4. The connection device (14) according to the preceding claim, wherein the body (16) includes a securing plate (38) and fillets (40) are formed at the connection between the outer surface of the radially outer tube (30) and each surface of the plate (38).
5. The connection device (14) according to any of the preceding claims, said connection device (14) being made by implementing a direct metal laser fusion method.
6. A circuit (10) for supplying with fluid a turbomachine member such as a fuel injector for a combustion chamber of an aircraft turbomachine including a connection device (14) according to any of the preceding claims.
7. An aircraft turbomachine including at least one member connected to a system for supplying the member with fluid by a connection device (14) according to any of claims 1 to 5.

Images