RU2782058C2 - Improved fireproof device intended for being placed between end of pylon of suspension of turbomachine of aircraft and casing of mentioned turbomachine separating inter-flow compartment - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to engines of an aircraft. Fireproof device (50) is proposed, intended for being placed between a pylon of suspension (9) of a two-contour turbomachine of an aircraft and connecting casing (30) provided for this turbomachine. The connecting casing is intended for coupling of upstream ring (10) limiting part of inter-flow compartment (8a) with bracket (22) passing radially through a secondary flow of the turbomachine. Device (50) is made in the form of a mono-block, and it contains two contact edges (52a, 52b). At the same time, first edge (52a) has C-shaped section, second edge (52b) is carried by a support part through a connection zone.

EFFECT: prevention of reaching by the fire of an upstream zone of a suspension pylon located nearly; protection of the pylon from the fire, ease of manufacture and embedding of a protection device into a protection zone.

10 cl, 17 dwg

Description

FIELD OF TECHNOLOGY

SUBSTANCE: invention relates to fire protection function between the interflow compartment of a bypass turbomachine of an aircraft and the area upstream relative to the suspension pylon of this turbomachine. It is designed, in particular, to prevent the propagation of a flame originating in the interflow compartment into an area upstream of the suspension pylon.

The invention is applicable to any type of bypass turbomachinery, and in particular to a turbojet engine.

BACKGROUND OF THE INVENTION

In a bypass aircraft turbomachine, one or more brackets are typically provided downstream of the supercharger and extend radially through the secondary flow. This bracket is usually installed to connect the supercharger compartment, located around the outer circumferential wall of the intermediate case, with the interflow compartment. These two compartments typically house equipment and accessories, while a bracket located between them allows passage of various items such as electrical cables and/or fluid conduits.

The radially inner end of such a bracket is connected to the upstream ring, partially limiting the interflow compartment, radially outward. Thus, this ring forms the upstream end of the set of shrouds forming the outer envelope of the interflow compartment. To ensure the connection between the bracket and the upstream ring, two connecting casings are installed between them, which are located respectively on the side of one and the other upstream end of the suspension pylon.

The suspension pylon for attaching the turbomachine to an aircraft wing element may actually have an upstream end located near the junction between the bracket passing through the secondary stream and the upstream of the interflow compartment. The problem then arises of the fire retardant function, since it is necessary to avoid the spread of possible flames that may occur in the interstream compartment, in particular, to prevent this flame from reaching the upstream zone of the suspension pylon located nearby.

Thus, there is a need to provide a fire retardant device that is designed to provide the desired function, allows it to be easily incorporated into the dense and complex environment of the area in question, and is easy to manufacture.

SUMMARY OF THE INVENTION

To solve this problem, the object of the invention is first of all to provide a fire protection device intended to be installed between the upstream end of the suspension pylon of a bypass turbomachine of an aircraft and a connecting casing installed on this turbomachine, and said connecting casing is intended to connect the upstream end of the ring restricting the radially in the outward direction of the part of the interflow compartment, with a bracket passing radially through the secondary flow of the turbomachine. According to the invention, the device includes:

a contact structure comprising a first contact edge having a C-shaped cross section, preferably a semicircular cross section, wherein the contact structure also comprises, at one of the longitudinal ends of the first contact edge, a spiral socket, preferably in the form of a circular helix, one of whose axial ends installed in the continuation of the first edge, and the other axial end of which is closed, and the first edge and the spiral pipe together form the first contact end extending along the first curved line;

- carried the supporting part; and

- a second contact edge resting on the support part through the connection zone, which bears the helical socket of the contact structure, the second contact edge having a second contact end extending along a second line different from the first line.

In addition, the flame retardant device is a monoblock.

The invention thus proves advantageous in that it provides a flame retardant device which proves to be effective, which fits perfectly into its environment, and whose monobloc nature makes it particularly convenient and cheap to manufacture, in particular in terms of the tools required.

The monobloc appearance is made possible by the simple geometry of the device according to the invention, in particular by the use of contact edges. In addition, they do not require the use of an insert during the manufacture of the device, in contrast to, for example, the implementation of tubular contact zones, called rolled or helical. Moreover, the edge is usually easily deformed, so that there is no need for the operation of prestressing it after it has been assembled. The deformation required to make it function as a barrier against the spread of fire may simply be propagated from the carrier to the surrounding element, such as from the support to the junction of a detachable nacelle casing to be cut into the zone.

It should be noted that these advantages are not compromised by the presence of a spiral tube, provided that the latter remains open at one of its axial ends. This characteristic ensures, in particular, the ease of manufacturing a part in the form of a monoblock. This spiral tube, located at one of the longitudinal ends of the first contact edge, locally makes it easier to adjust the seal, due to its cross section, which is larger than that of the first C-shaped edge, which it continues.

Additionally, the C-shape of the first contact edge is advantageous in that it is compatible with existing flame retardant devices, including helical connections fixed at their longitudinal ends with connecting pins. In fact, the longitudinal end of the first contact edge of the flame retardant device according to the invention can thus ideally interact with the connecting pin of the additional flame retardant device already installed on the propulsion system. This complementarity of forms facilitates the articulation between the two devices, which is comparable to the introduction of a pin into the open section of the first contact edge.

In other words, the C-shape of the first edge makes it easier to adapt the device according to the invention to a standard device already provided for a propulsion system. Therefore, when this propulsion system contains two fire protection devices fitted to each other so that they are installed in each other's continuation, replacement of one of the two devices becomes possible. Thus, the maintenance of these flame retardants becomes easier and safer.

Finally, it has been found that in the presence of a contact structure and a second contact edge, the flame retardant device according to the invention allows the formation of two different and almost adjacent physical barriers. One is designed to block possible fire in the interstream compartment so that it does not spread either peripherally to the side surface of the pylon, or radially to the end of the upstream end of the latter, and the other is installed so that this possible fire does not spread axially downstream, along the same side surface of the pylon.

It is preferred that the invention provide at least one of the following optional technical features, taken alone or in combination with each other.

It is preferable that said second line is straight, and preferably almost perpendicular to the first contact surface, almost flat, to which the first curved line belongs. However, other line shapes and other slopes may be used, depending on the surfaces brought into contact, without departing from the scope of the invention.

It is preferable that the device also comprises a fastening part carrying a first contact edge, said fastening part being preferably passed through through holes of the fasteners.

It is preferable that the support part bears, opposite the second edge and its connection zone, elongated fastening elements. These elongated fasteners can then easily interact with the connecting casing, for a better hold on the latter.

It is preferred that the device be formed by applying at least one layer of elastomeric material, preferably silicone elastomer, and at least one fibrous layer, preferably ceramic, glass or meta-aramid (poly(m-phenylene isophthalamide) )). However, other types of layers are possible without departing from the scope of the invention. It should be noted that a layer of ceramic fabric is particularly effective for the flame retardant function, while a layer of fiberglass makes it possible to make the package more rigid and to restrain the silicone elastomer from slipping in a plane perpendicular to the direction of application of the layers, in the event of mechanical stress in this latter direction. Finally, the layer of meta-aramid fibers also allows for such stiffening.

It is preferred that one or more fibrous layers extend along the entire length of the first contact edge and the spiral tube, and also that one or more fibrous layers extend along the entire length of the second contact edge.

The aim of the invention is also to create a propulsion system for an aircraft, containing a bypass aircraft turbomachine, as well as a turbomachine suspension pylon designed for its attachment to an aircraft wing element,

The turbomachine contains an interflow compartment located between the primary flow and the secondary flow of the turbomachine, as well as a bracket passing radially through the secondary flow and communicating with the interflow compartment, the latter being partially limited radially outward by an upstream ring connected to the bracket by means of two connecting casings located respectively on one and the other side of the upstream end of the suspension pylon, in the transverse direction of the propulsion system,

moreover, the upstream end of the suspension pylon contains two side surfaces, as well as a peripheral bearing surface that follows the contour of the base of this upstream end of the pylon.

According to the invention, the propulsion system also comprises, associated with at least one of the two connecting casings, a fire protection device, such as described above, inserted between the upstream end of the suspension pylon and the connecting casing to which the device is attached.

Preferably, the first contact end rests on the peripheral bearing surface of the upstream end of the suspension pylon, and the second contact end of the second contact edge rests on the corresponding side surface of the upstream end of the suspension pylon.

It is preferable that the first curved line belongs to the first contact surface, almost flat and almost parallel to the transverse direction, as well as to the longitudinal mounting direction, and the second line, defined by the second contact edge, is a straight line extending almost parallel to the vertical mounting direction.

It is preferred that the second contact edge is preferably defined by the lateral surface of the upstream end of the suspension pylon and the attachment of the removable nacelle casing.

Finally, the propulsion system also comprises two connecting casings connected to each other, an additional fire protection device inserted between the upstream end of the suspension pylon and the connecting casing, to which the additional device is attached, the latter containing a contact structure in the form of a helical connection, the longitudinal end of which is provided secured by a connecting pin cooperating with the other longitudinal end of the first contact edge belonging to the flame retardant device. As mentioned earlier, this feature illustrates the fact that the invention is in a form that allows the device to be assembled on another existing device, with a different design and already installed on a propulsion system.

Other advantages and characteristics of the invention will become apparent from the non-limiting detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

This description will be given in relation to the accompanying drawings, of which:

- Figure 1 is a partial and schematic perspective view of a propulsion system according to a preferred embodiment of the invention;

- Figure 2 is an exploded perspective view of the part of the propulsion system shown in Figure 1;

- Figure 3 is a perspective view of the part shown in the previous Figure;

- Figure 4 is a side view of the part shown in the previous Figure, with the flame retardant device shown in phantom;

- Figure 5 is a section taken along the line V-V in Figure 4;

- Figures 6a and 6b are perspective views of the flame retardant device shown in the previous Figures from different viewing angles;

- Figure 6c is a sectional view taken along the plane Pc in Figure 6b passing through the volute;

- Figure 6d is a plan view of a part of the flame retardant device shown in Figures 6a and 6b;

- Figure 7 is a perspective view of the part shown in Figures 2-4, schematically showing the sealing line obtained due to the flame retardant device;

- Figure 8 is a perspective view of the part shown in Figures 2-4, showing in particular the second-armed contact edge of the flame retardant device, in tension;

- Figure 9 is a sectional view taken along line IX-IX of Figure 10;

- Figure 10 is a sectional view taken along line X-X of Figure 9;

- Figure 11 represents a combination between a fire protection device such as shown in the previous Figures and an additional standard device;

- Figure 12 is a rear view of part of the combination of devices shown in Figure 11;

- Figure 13 is a section similar to the view presented in the previous Figure; and

- Figure 14 is a sectional view taken along line XIV-XIV of Figure 13.

DETAILS OF PREFERRED EMBODIMENTS

Referring first to Figure 1, which is a partial representation of a propulsion system 100 according to a preferred embodiment of the invention. This installation 100 includes a bypass turbomachine 1 for an aircraft, as well as a suspension pylon 9 of this turbomachine on an aircraft wing element (not shown).

The propulsion system 100 has a longitudinal direction X corresponding also to the longitudinal direction of the turbomachine 1 and the longitudinal direction of the pylon 9. The installation 100 also has a transverse direction Y as well as a vertical direction Z corresponding to the height direction. Three directions X, Y and Z are mutually perpendicular to each other and form the right coordinate system.

It is preferred that the pylon 9 allows the turbomachine 1 to be suspended under the wing of the aircraft. This pylon includes a structural part designed to receive forces from the turbomachine, and this part is commonly referred to as the primary structure or the rigid structure. It is generally in the form of a box, with Figure 1 showing only the upstream end 7 . The pylon is also provided with secondary structures (not shown) in the form of aerodynamic fairings.

In the preferred embodiment described and shown, the turbomachine 1 is a bypass and double-casing turbojet engine. The turbojet 1 has a central longitudinal axis 2 parallel to the X direction and around which its various components extend. It contains from inlet to outlet along the main 5 direction of flow of gases through this turbomachine: a supercharger 3, then a gas generator, usually formed by compressors, a combustion chamber and turbines. These elements of the gas generator are surrounded by a main crankcase 6, also called the "core" crankcase, which delimits the interflow compartment 8a radially inwardly. This compartment 8a is further delimited radially outward by one or more casings, including an upper 10 downstream ring, which is the only one shown in Figure 1. The upper 10 downstream ring is located at the outlet of the sleeve 12 of the intermediate 14 crankcase of the turbojet engine. Intermediate 14 crankcase also includes an outer 16 circumferential wall located at the outlet of the crankcase 18 of the supercharger. It also includes outlet 20 guide vanes located downstream of the supercharger blades and connecting the sleeve 12 with the outer 16 circumferential wall.

The blower housing 18 and the outer circumferential wall 16 together, radially inwardly define the blower compartment 8b. In addition, this compartment 8b is limited radially outward by one or more shrouds (not shown), forming part of the turbojet nacelle. Like the inter-stream compartment 8a, this compartment 8b houses equipment and ancillary equipment, as is commonly known in the art.

To connect the two compartments 8a, 8b, one or more brackets 22 are provided. These are, for example, two brackets 22, which are equipped with a turbojet engine, located respectively at clockwise positions called 12 o'clock and 6 o'clock. These brackets 22 are hollow and allow, for example, electrical cables and/or fluid conduits to be laid. More specifically, these brackets connect the downstream portion of the outer circumferential wall 16 to the upstream ring 10 . To do this, they pass through the secondary 26 flow of the turbojet engine, and this flow is partially limited outwardly by the circumferential 16 wall, as well as casings (not shown) located downstream relative to it, and partially limited inwardly by the upper 10 downstream ring interstream 8a compartment. The secondary stream 26 is added to the primary stream 28 which normally passes through the gas generator.

Let us now turn to Figures 2-5, where a part of the propulsion system 100 is shown, including the upper 7 downstream end of the pylon 9, the bracket 22 located at the 12 o'clock position, and the upper 10 downstream ring. More precisely, on one and the other side of the upper 7 downstream end of the pylon 9 in the Y direction, respectively, two connecting 30 casings are provided, providing aerodynamic pairing between the bracket 22 and the upper 10 downstream ring. Thus, the latter is not completely enclosed by 360°, but has an angled hole centered at the 12 o'clock position, at the level of which two connecting casings 30 provide connection with the radially inner end of the bracket 22.

In the Figures, the assembly of the various elements to each other is only shown from the side of the pylon, but it is understood that on the other side of the upper 7 downstream end of the pylon 9 an identical or similar assembly, preferably symmetrical, is provided. Thus, on each side of the pylon 9, the connecting casing 30 has an upper end 32 downstream, which should be located at the outlet of the intermediate casing bushing. Its upper 33 end is connected to the wall of the bracket 22, while its peripheral end 35 is connected to the peripheral end of the upper 10 downstream of the ring. Finally, its downstream end 38 defines a chute corner recess 39 housing a nacelle connection 40, which is preferably supported by a removable nacelle casing (not shown in Figures 2-5). This connection 40, also referred to as a tee connection or a tripod connection, actually includes a node from which extend the first 40a part of the connection, entering the socket 39, and then into the upper 10 downstream ring, and the second 40b part of the connection, entering the socket 39 , and then into the bracket 22, and the third 40c part of the connection, which is included in the side 42 surface of the pylon. Each leg of connection 40 is a tubular, helical, or roll type leg.

Thus, connection 40 assumes the position shown in Figure 3 after closing the removable nacelle casing on which it is installed, while the casing has an outer surface located downstream of the outer 34 surface of the connecting casing 30.

The upper 7 downstream end of the pylon 9 has a base 44 from which extend, in particular, two side 42 surfaces. The base 44 is installed integrally with the peripheral 46 bearing surface in a general U-shape, following the contour of this base 44. It is almost flat, parallel to the X and Y directions. end of the pylon. To satisfy this function, the installation 100 includes a flame retardant device 50 according to the invention associated with each connecting 30 casing. In an alternative embodiment of the invention, which will be described later, the installation 100 contains a fire retardant device according to the invention and associated with one of the two connecting casings 30, as well as a more standard additional fire protection device associated with the other connecting casing 30.

The two connecting casings 30 may have identical or similar designs, being, for example, symmetrical about the longitudinal plane XZ passing through the axis 2. This configuration is schematically represented in Figure 2, showing also the combination of two devices 50 according to the invention, which are connected at the level of their upstream ends, together forming a profile similar to the profile of the peripheral 46 bearing surface on which they rest.

With regard to Figures 2-5, it will be described that one of the two devices 50, whose designs are identical or similar, they are, for example, mounted symmetrically with respect to the longitudinal plane XZ passing through the axis 2.

The fire protection device 50 is thus inserted between the upstream end of the pylon 7 and its connecting casing 30 on which the same device is fixed. Generally speaking, device 50 has a first contact edge 52a as well as a second contact edge 52b, the first edge 52a resting on the radially outer surface of the peripheral bearing surface 46, half of it. This first contact edge 52a ensures that the fire that originates in the interflow compartment 8a does not propagate either peripherally to the side surface 42 of the pylon, nor radially outward towards the end face of the upstream end of the same pylon.

The second 52b contact edge, in turn, rests on the side 42 surface of the pylon, downstream of the two parts 40a, 40b of the nacelle 40 connection. , along the side 42 surface of the pylon.

The device 50 with its edges provides an ingenious and effective solution for providing a flame retardant function despite the relative movements that may be observed between the turbojet and the pylon during the various stages of aircraft flight.

Figure 5 shows the first edge 52a with a low level of compression due to the relative position of the turbojet and the pylon. This first 52a edge has a C-shaped cross-section, preferably semi-circular, corresponding to its nominal unstressed shape. Thus, when the first edge 52a is compressed, it has a shape that tends to flatten/ovalize, which causes its two peripheral ends 53 to approach each other in the compression direction corresponding to the Z direction.

One of the two peripheral 53 ends rests on the peripheral 46 bearing surface, almost perpendicular to this supporting part. The other end 53 rests on the fastening 56 part, through which fasteners 54 such as pins or rivets pass. These elements 54 actually pass through the fastening 56 part of the device 50, as well as the first 58 support of the connecting casing 30, located radially inwardly between the latter and the peripheral 46 bearing surface. The first leg 58 has an overall U-shape open transversely outward, while the first semi-circular edge 52a is open transversely inward.

Thus, the fastening portion 56 extends in the Z direction downwards, parallel to the base of the U-shaped support 58, until it joins one of the peripheral 53 ends of the first semi-circular edge 52a. The area of flexible connection between the fastening 56 part and the end 53 is located near the connection area between the base of the U-shaped support and its lower branch. Therefore, it is preferable that the upper part of the first edge 52a rests on the lower branch of the first 58 U-shaped support.

Additionally, in a cross section, such as the cross section of Figure 5, it is preferred that the two peripheral 53 ends of the first edge 52a fit into a vertical imaginary line along which the fastening 56 portion extends. This geometry, in particular, is observed in the unstressed state of the first edge 52a. However, it has been found that the design of the flame retardant 50 allows contact to be maintained between the first edge 52a and the peripheral bearing surface 46, regardless of the relative motions observed between the turbojet and the pylon, and this is the case in each of the three directions X, Y, and Z.

The peripheral 53 end interacting with the bearing surface 46 defines the majority of the first contact end 70a of the pylon device 50 . This first contact end 70a is terminated by a small part emanating from a helical 71 stub, ie a tubular stub shown in Figures 6a-6d and preferably having a circular cross section, the cavity of which is preferably left empty. This socket 71 forms with the first edge 52a a contact structure 73 which must rest on the peripheral 46 bearing surface of the pylon.

The pipe 71 is located in the continuation of the longitudinal lower 75a downstream end of the first 52a edge. More specifically, the round 71 spiral pipe has an upper 77a downstream axial end, which is open, and which is installed in the continuation of the longitudinal lower 75a downstream end of the lip 52a. Therefore, at the level of the transition between the edge 52a and the nozzle 71 driven by the ends 75a, 77a, the contact 73 transitions from a circular to a semi-circular area, possibly gradually, but preferably abruptly. More generally, regardless of the shape of the lip 52a and the shape of the nozzle 71, the contact structure 73 goes from a closed area (inside the nozzle 71) to half of this closed area (inside the C-shaped edge 52a).

The outer and inner diameters of the two ends 75a, 77a, respectively, are almost identical. In addition, these diameters are almost constant throughout the entire contact 73 structure, even if slight deviations may be observed, for example in the range of more or less than 15%.

The axial downstream 77b closed end of the nozzle 71, for example, has the shape of a dome. Due to this overlap, as well as the tubular shape of the nozzle 71, this downstream part of the contact structure 73 provides a stronger and easier to achieve seal due to the greater transverse extension than the first 52a C-shaped edge extended by this nozzle.

As mentioned earlier, the round 71 spiral tube is only a small part of the contact 73 structure, namely, only its downstream end. It is preferable that its length is not more than 20% of the total length of the contact 73 structure, and even more preferably, it is less than 15%.

It should be noted that, as with the lip 52a, the preferably round nature of the nozzle 71 corresponds to its nominal shape as seen in the unstressed state. Thus, after placement on the propulsion system, this nozzle 71 is subjected to flattening/ovalization due to the relative movements between the turbojet and the pylon, and this occurs in each of the three directions X, Y and Z. However, on this nozzle, mainly subjected to compressive load, other types of deformation may be observed without departing from the scope of the invention.

Together, the first 52a contact edge and the lower end of the nozzle 71 allows you to install the first line of sealing on the peripheral 46 bearing surface. As shown in Figure 7, we are talking about the first 72a curved line, repeating the profile of half of the bearing surface 46 associated with the contact structure. The first 70a contact end of this contact 70 structure (not shown in Figure 7, but visible in Figures 6a and 6b) extends along this first curved line 72a, in an overall L-shape.

One feature of the invention is based on the fact that the device 50 includes the aforementioned second edge, the function being to establish a second seal line 72b on the side 42 surface of the pylon 9. It is preferred that this second line is a straight line almost parallel to the Z direction. preferably, the two lines 72a, 72b shown in Figure 7 converge at the level of the radially inner downstream end of the device 50. be connected by a connecting material 79, shown in Figure 6b, connecting the overlapped 77b axial downstream end of the nozzle 71 with the radially inner end of the second 52b contact edge.

Referring again to Figures 6a-6d, the device 50 will be described in more detail. In these Figures, first of all, the first curved line 72a is shown, along which the first 52a edge and the round 71 spiral pipe follow each other. Line 72a belongs to the nearly flat first contact surface S1, which corresponds to the radially outer circumferential 46 surface of the bearing surface. This surface S1 may be strictly flat, or may have one or more levels with a very low height, for example not exceeding a few millimeters. Thus, it is preferable that the surface S1 corresponds to the XY plane of the propulsion system 100. Additionally, the first 72a curved line that belongs to this XY plane also has an overall L-shape, in which the angle between the base L and the leg L can be rounded, and the free end of the branch L of which can also be rounded.

The fixing part 56 extends to a height in the Z direction from the edge 52a, in the form of a plate, through which pass through holes 76 pass, designed to pass through them the above pins 54. The through holes 76 can be reinforced with inserts 81, which are then installed on the device 50.

At the level of the longitudinal lower 75a downstream end of the first 52a edge, the device 50 includes a bearing 60 part, which also extends in height almost in the Z direction, from the upper 53 peripheral end of this edge. More specifically, this support 60 is thicker and is adjacent to the rib 80 provided to increase the mechanical strength of the device 50. The rib 80 is inserted between the attachment 56 and the block-shaped support 60. It also extends in height almost in the Z direction, parallel to the fastening part 56 from which it can be separated, in the direction of the first curved line 72a. Rib 80 has an intermediate thickness between the length of the fastening 56 part and the length of the support 60 part. The same applies to its height in the Z direction.

The function of the support part 60 is to support the second edge 52b by means of a connection zone 62 inserted therebetween. The connection zone 62 has a reduced thickness and serves as a hinge connection with the second edge 52b, which preferably remains straight and does not deform or slightly deform when bent, regardless of the level of compression.

The connection zone 62 extends from the support 60 almost in the X direction, downstream. At its radially inward end, connection zone 62 carries the top of the helical tube 71 which is located upstream of edge 52b supported by the downstream end of the same connection zone 62.

The second contact end 70b of the second edge 52b extends along the second line 72b, preferably straight and preferably almost perpendicular to the first contact surface S1. Thus, the second straight line 72b preferably extends almost in the Z-direction so that the edge 52b is in contact with the corresponding side surface of the pylon.

The outer radial end of the installation, formed by the elements 60, 62 and 52b, is beveled, as best seen in Figure 6b.

Moreover, the second 52b contact edge has an increasing thickness in the direction from its base 68b, shown in Figure 6a, to the second contact end 70b. Consequently, this latter may have a superficial character, for example in the form of a vertical strip. In the unstressed state shown in this Figure 6d, between the normal 64b to the side of the pylon (not shown) and the common second edge direction 66b given between the base 68b and the second 70b contact end of the edge 52b, the angle of inclination B0 can be observed.

In the assembled state of the device 50, its second contact edge 52b is displaced in the Y direction by the third 40c nacelle connection part. With reference to Figure 8, when the casing of the nacelle 82 (represented only schematically) is closed, the third 40c branch of the connection 40 integral with this casing will rest on the second 52b edge. It then compresses between the side surface 42 of the pylon and the third part 40c of the joint 40, which influences the rotation of the edge 52b in accordance with its joint area 62. Due to this rotation, the angle B0 increases compared to that observed in the unstressed state of Figure 6d. The value of this angle B0 depends on the level of compression of the flame retardant 50 device, which in turn depends on the amplitude of the relative movements between the turbojet and the pylon. Figure 8 also shows that the third 40c part of the connection 40 is compressed in the Y direction, which affects that its tubular seal part is deformed between the nacelle shell 82 and the edge 52b. Thus, the tubular portion, which has an almost circular cross-section in the unstressed state, is flattened under compression into, for example, an elliptical, oval or similar shape.

This Figure 8 also shows that the presence of the helical 71 nozzle severely restricts the leakage area 91 between the side 42 surface of the pylon and the same nozzle, even at high levels of deformation leading to increased values of the angle B0. Providing such a downstream end in the form of a helix, closed downstream and open upstream, facilitates the easy achievement of a proper and controlled seal with the side surface of the 42 pylon. In this way, the leakage section 91 remains acceptable even if the second edge 52b rotates a lot.

Also in relation to Figure 8, it is shown that the supporting 60 part of the device 50 enters the second 86 support provided on the connecting casing 30, at the level of its lower 38 downstream end, forming the socket of the connection 39 shown in Figure 2. The second 86 support, which best seen in Figure 7, has openings 88 designed to receive elongated fasteners 90 supported by the support 60 from the side adjacent to that on which the edge 52b and its connection area 62 is located. These elongated members 90 are integral with or attached to the device 50. They are formed, for example, by rods, one end of which must be pressed against the opposite surface of the second 86 support through which they pass.

Another feature of the invention consists in the manufacture of a monoblock flame retardant 50 device. In other words, all of the aforementioned elements of the device 50 are made in one piece, preferably by injection molding. In addition, this production of a monobloc is undeniable due to the presence of the spiral tube, since it remains open at one of its axial ends and preferably extends over a very short length.

The elongated fasteners 90 are possibly built into this part as a whole, while the bushings 81 are considered as additional elements external to the device, since they form part of the fastening means on the connecting casing 30 .

For the manufacture of device 50, it may be a simple block of elastomer, but it is preferred that the latter be combined with one or more different functional layers.

In the example shown in Figures 9 and 10, the device 50 is formed by superposing, in the direction of thickness 92, the last layers of elastomeric material 99, and preferably of silicone elastomeric material, and fibrous 110 functional layers. Among these latter, it may be layers of fiberglass that enhance the rigidity of the device. Then, special fire-resistant layers can be provided, for example made of ceramic fiber. It is preferred that they be located in areas of the device that are more prone to ignition. Since the silicone elastomeric material of the layers 99 breaks down and converts to silica in the event of high temperature, the fabrics 110 used, due to their network, allow these degraded particles to be retained.

The interleaved layers can also be supplemented with meta-aramid 110 fibrous layers, again to increase the rigidity of the installation. One of these layers can even be applied to the outer surface of the edges to keep them from being worn and damaged by parts in contact with them.

It is preferred that the layers 99 and 110 are parallel to each other, following the profile of the device 50. At least one or more of them may extend the entire height of the device 50, and from one end to the other last in the direction of the aforementioned first 72a curved line.

In the X direction, the device 50 may have a length of 30-50 cm, while in the Y direction the width of this device is on the order of 10-20 cm. Finally, in the Z direction, the maximum height of the device 50 may be on the order of 15-20 cm. Each the edge 52a, 52b extends only a few centimeters.

With regard to the fire resistance provided by the device 50, in addition to meeting the normative standards ISO 2685-1998 and AC 20-135, the most unfavorable conditions are considered, namely, maintaining fire resistance in flight and on the ground. This entails, in particular, the development of a solution that provides a flame retardant function under repeated conditions:

- flame temperature: 1100±80°C;

- vibration: ±0.4 mm at a frequency of 50 Hz;

- pressure: 0.4 bar during the first 5 minutes of the test fire;

- test duration: 15 min, decomposition in 2 stages:

- 5 min: Overpressure applied; and

- 10 min: Atmospheric pressure;

- self-ignition within a limited time.

In the embodiment described above, there are two devices 50 according to the invention, which are associated with a peripheral 46 bearing surface. The connection between them proves to be particularly convenient for implementation at the level of the upper 75b downstream of the longitudinal ends of their respective first 52a edges. These two C-shaped ends 75b (which are shown in Figure 6b) can in fact easily overlap and thus provide fire barrier continuity at the level of the connection zone between the two devices 50.

But the invention also proves to be suitable for mounting on an existing propulsion plant, to replace only one of the two standard devices already in place on that plant. This functionality is presented in Figures 11-14 showing the combination between the device 50 according to the invention and an additional 50' flame retardant device with a standard design. The two devices are designed respectively to be mounted on two connecting casings 30 of the propulsion system.

The additional 50' flame retardant is of a conventional design, with several elements connected to each other. Typically, this includes a helical 71' connection extending almost the entire length of the device 50', and this connection must be pressed against the peripheral bearing surface of the pylon, in the form of a contact 73 structure of the device 50. In an unstressed state, such as shown in the Figures 11-14, the helical 71' connection has a circular section.

This helical 71' connection thus constitutes the contact 73' structure of the additional 50' device, and has an upper 75b' downstream longitudinal end provided with a connecting 112' pin. This pin 112' is hollow, also of circular cross section, with a diameter smaller than that of the helix, and possibly tapered at the level of its end capped portion. With regard to the device 50, the longitudinal upper 75b downstream end of its first 52a contact edge, with a C-section, it proved to be ideally adapted to interact with this connecting 112' pin. The inner diameter C can actually be almost equal to the outer diameter of the connecting pin 112', which allows the latter to be placed inside the longitudinal upper 75b downstream end in a C-shape. This overlap is shown in Figures 12-14 and is comparable to a box joint, allowing continuity of the fire barrier at the joint level between the new device 50 and the additional 50' device already installed on the propulsion system. The replacement of one of the two available devices is thus facilitated by the proposed construction of the invention.

Of course, various modifications may be made by those skilled in the art to the invention as described, by way of non-limiting examples only, and the scope of which is defined in the appended claims.

Claims (17)

1. A fireproof (50) device designed to be placed between the upper (7) downstream end of the suspension pylon (9) of a double-circuit (1) aircraft turbomachine and the connecting (30) casing provided for this turbomachine, and the said connecting casing is designed to mate the upper (10) along the flow of the ring, limiting radially outward, part of the interflow (8a) compartment, with a bracket (22) passing radially through the secondary (26) flow of the turbomachine, characterized in that the device contains contact (73) structure containing the first (52a) contact edge having a C-shaped section, and the contact structure also contains on one of the longitudinal (75a) ends of the first (52a) contact edge a spiral pipe (71), one of the axial (77a ) of the ends of which is open and is installed in continuation of the first edge (52a), and the other axial (77b) end of which is closed, the first edge and the spiral nozzle together forming the first (70a) contact end extending along the first (72a) curved line; support (60) part; the second (52b) contact edge carried by the supporting (60) part through the connection zone (62), which bears the spiral pipe (71) of the contact (73) structure, the second (52b) contact edge having a second (70b) contact end, extending along a second line (72b) different from the first line (72a), and the fact that the flame retardant (50) device is a monoblock. 2. Device according to claim 1, characterized in that said second (72b) line is straight and preferably almost perpendicular to the first (S1) contact surface, almost flat, to which the first (72a) curved line belongs. 3. The device according to any of the preceding paragraphs, characterized in that it also contains a fastening (56) part bearing the first (52a) contact edge, and through said fastening part, preferably pass through (76) holes for fastening (54) elements . 4. The device according to any one of the preceding claims, characterized in that the support (60) part bears, opposite the second (52b) edge and its connection zone (62), elongated (90) fasteners. 5. The device according to any of the preceding claims, characterized in that it is formed by applying at least one layer (99) of an elastomeric material, preferably of a silicone elastomeric material, and at least one fibrous (110) layer, preferably ceramic, glass or meta-aramid. 6. Propulsion system (100) for an aircraft containing a bypass turbomachine (1) of the aircraft, as well as a suspension pylon (9) of the turbomachine, designed for its attachment to the wing element of the aircraft, a turbomachine (1) containing an interflow (8a) compartment located between the primary (28) flow and the secondary (26) flow of the turbomachine, as well as a bracket (22) passing radially through the secondary (26) flow and communicating with the interflow (8a) compartment , and the latter is partially limited radially outward by the upper (10) downstream ring connected to the bracket using two connecting (30) casings located respectively on one and the other side of the upper (7) downstream end of the suspension pylon (9) , transverse (Y) propulsion system, the upper (7) downstream end of the suspension pylon, containing two side (42) surfaces, as well as a peripheral (46) bearing surface, following the contour of the base (44) of this upper (7) downstream end of the pylon, characterized in that the propulsion system (100) also contains a fire-retardant (50) device associated with at least one of the two connecting (30) casings according to any of the previous paragraphs, located between the upper (7) downstream end of the suspension pylon and the connecting (30 ) by the casing to which the device (50) is attached. 7. Installation according to the previous paragraph, characterized in that the first (70a) contact end rests on the peripheral (46) bearing surface of the upper (7) downstream end of the suspension pylon, and in that the second (70b) contact end of the second (52b) contact edge rests on the corresponding (42) side surface of the upper (7) downstream end of the suspension pylon. 8. Installation according to claim 6 or 7, characterized in that the first (72a) curved line belongs to the first (S1) contact surface, almost flat and almost parallel to the transverse direction (Y) and also to the longitudinal direction (X) of the installation (100) , and in that the second (72b) line defined by the second (52b) contact edge is a straight line extending almost parallel to the vertical direction (Z) of the installation. 9. Propulsion system according to any one of paragraphs. 6-8, characterized in that the second (52b) contact edge is limited between the side (42) surface of the upper (7) downstream end of the suspension pylon (9) and the connection (40) of the removable casing of the gondola (82). 10. Propulsion system according to any one of paragraphs. 6-9, characterized in that the propulsion system (100) also contains two connecting (30) casings connected to each other, an additional (50') fire protection device located between the upper (7) downstream end of the suspension pylon and the connecting (30) casing to which an additional (50') device is attached, the latter containing a contact structure in the form of a helical (71') connection, the longitudinal (75b') end of which is provided with a connecting (112') pin interacting with the other longitudinal (75b) end of the first (52a) the contact edge belonging to the flame retardant (50) device.

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