RU2795414C2 - Improved fire-fighting device intended to be installed between the end of the aircraft gas turbine engine back prop and the gas turbine engine hood limiting the intermediate flow compartment - Google Patents

Abstract

FIELD: fire-fighting device.

SUBSTANCE: device (50) designed to be installed between the back prop of the fastening of a bypass gas turbine engine of an aircraft and the connecting hood of said gas turbine engine, while the connecting hood is designed to connect the upstream ring, which limits the intermediate flow compartment, with a rack passing radially through the secondary flow of the gas turbine engine. According to the invention, the device (50) comprises two contact edges (52a, 52b) extending along different lines (72a, 72b), including the first C-section edge (52a) included in the contact structure (73) and the second edge (52b) containing at its end a locking section (63) protecting the contact structure (73).

EFFECT: fire-fighting device that is effective, fits perfectly into its environment, and the design of which makes it extremely easy and inexpensive to manufacture, for example, due to its monoblock construction.

10 cl, 25 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to a fire prevention function between the intermediate flow compartment of an aircraft bypass gas turbine engine and the upstream strut area of the gas turbine engine. In particular, it is intended to prevent the spread of a fire originating in the intermediate flow compartment to the upstream brace area.

The invention can be applied to any type of bypass gas turbine engine, and in particular to a turbojet engine.

PRIOR ART

In an aircraft bypass gas turbine engine, the fan outlet typically has one or more props extending radially through the secondary flow. Typically, this rack is configured to connect the fan compartment, located around the outer shell of the intermediate crankcase, with the intermediate flow compartment. These two compartments typically house the units and auxiliaries, while the rack between them serves to pass various items such as electrical cables and/or piping.

The radially inner end of such a rack is connected to an upstream ring partially delimiting the intermediate flow compartment in a radial outward direction. This ring forms the upstream end of a set of hoods forming the outer casing of the intermediate flow compartment. To provide a connection between the strut and the upstream ring, two connecting hoods are installed between them, which are located respectively on the side on one side and on the other side of the upstream end of the strut of the attachment.

The strut mount, which serves to mount the gas turbine engine to an aircraft wing element, may have an upstream end near the junction between the post passing through the secondary flow and the upstream intermediate flow compartment ring. The problem of the fire-fighting function arises, since the aim is to avoid the spread of a possible fire that has arisen in the intermediate flow compartment, in particular, to prevent the flame from reaching the nearby upstream strut bracing zone.

Therefore, there is a need for a fire-fighting device, the design of which guarantees the performance of the required function, allows it to be easily integrated into the dense and complex environment of the considered area, and allows for easy manufacture.

DISCLOSURE OF THE INVENTION

To solve this problem, the first object of the invention is a fire-fighting device designed to be installed between the upstream end of the strut mounting of a bypass gas turbine engine of an aircraft and the connecting hood, which is equipped with this gas turbine engine, while said connecting hood is designed to connect the upstream ring, limiting radially outward part of the compartment of the intermediate flow, with a rack passing radially through the secondary flow of the gas turbine engine. According to the invention, the device contains:

- a contact structure containing a first contact edge, preferably having a C-shaped section and forming a first contact end extending along the first line, preferably a curved line, while at one of the longitudinal ends of the first contact edge, the contact structure also contains an end section, one of the ends which is open and is located in the continuation of the first edge, and the other end of which is closed;

- base area; And

- a second contact edge located on the support section through the connecting zone, on which the end section of the contact structure rests, while the second contact edge has a second contact end extending along a second line different from the first line, while at one of its ends the second contact the lip has a closure portion protruding along the second line, the closure portion being spaced and opposite the closed end of the end section.

Thus, the invention provides a fire-fighting device that is effective, fits perfectly into its environment, and whose design makes it extremely easy and inexpensive to manufacture, for example, due to its monoblock construction.

Indeed, the one-piece design is made possible by the simple geometry of the claimed device, in particular by the use of contact edges. In addition, the edges do not require the use of an insert during the manufacture of the device, in contrast to, for example, tubular contact zones, referred to as bead or bead zones. In addition, the edge can be easily deformed, so there is no need to subject it to a special prestressing operation before attaching it. The deformation necessary to provide its function as a fire barrier can simply be obtained by pressing an adjacent element, for example by pressing a nacelle hood gasket that is to be compressed in this area.

It should be noted that these advantages are not diminished by the presence of an end section closed at one of its ends, given that it remains open at its other end. This feature ensures, in particular, the easy production of the monobloc part. This closed end section located at one of the longitudinal ends of the first contact edge allows for easier local control of the seal due to its larger cross section than the cross section of the first C-shaped edge it extends.

In addition, the C shape of the first contact edge is preferred because it is compatible with existing fire fighting devices including bead-like gaskets equipped with connecting pins at their longitudinal ends. Indeed, the longitudinal end of the first contact edge of the inventive fire fighting device can ideally interact with the connecting pin of the complementary fire fighting device already installed in the power plant. This complementarity of forms facilitates the connection between the two devices, which can be thought of as the fit of a pin into the open section of the first contact edge.

In other words, the C-shape of the first edge facilitates the connection of the claimed device with the classic device, which is already equipped with the power plant. Therefore, when this power plant contains two fire fighting devices connected in such a way that they are in continuation of each other, it becomes possible to replace one of the two devices. This makes it easier and safer to maintain these fire fighting devices.

In addition, given the presence of the contact structure and the second contact edge, the claimed fire-fighting device can form two physically different and essentially adjacent barriers. One of them is provided in order to stop a possible flame in the intermediate flow compartment so that it does not spread in the circumferential direction to the side of the strut or in the radial direction to its upstream end side, and the other is provided in such a way that this possible flame does not spread. axially downstream along the same side of the strut.

One of the distinguishing features of the invention is the presence of a protruding locking area inside the second contact edge. This locking section closes, without coming into contact with it, the closed end of the end section provided inside the contact structure in the continuation of the first edge. During operation, when this end section deforms, possibly opening the cross section of the hole for the flame, the shut-off section overlapping it significantly reduces the risks of axial penetration of this flame into the upstream brace zone and even completely eliminates them. The gap remaining between the locking section of the second edge and the closed end continuing the first edge makes it possible not to interfere with the deformation of the contact structure during operation of the power plant. Together with the obstruction section of the second edge and the closed end extending the first edge, this gap forms a kind of tortuous passage, significantly reducing the risk of flame passage up to its propagation through the aforementioned possible hole section resulting from deformation of the closed end of the contact structure.

The invention includes at least one of the following optional technical features, considered alone or in combination.

The locking section has a first contact side forming part of the second contact end of the second contact edge, as well as a second side opposite to the first and moving away from the first contact side, approaching the closed end of the end section, while the second side is preferably curved.

The closed end of the end section has a convex shape in the direction of the locking portion belonging to the second contact edge. Without departing from the scope of the invention, the end section may include a section in the form of a roller, continued by a closed end.

In the direction of the second line, the locking section ends in an indent with respect to the first contact end. This reduces the risks of this closure portion coming into contact with the element on which the first contact end rests and deforming upon such contact.

As mentioned above, the device is preferably one-piece.

Said second line is straight and preferably substantially orthogonal to the first substantially planar contact surface into which the first curved line is inscribed. However, without departing from the scope of the invention, other line shapes and other slopes can be chosen depending on the contact surfaces.

The device also comprises a fastening section, on which the first contact edge is made, while in the said fastening section, holes are preferably made for the passage of fasteners.

Opposite to the second edge and to its connection zone, the supporting section contains elongated fasteners. These elongated fasteners can easily interact with the connecting hood for better retention.

The device is made by overlapping at least one layer of elastomeric material, preferably silicone elastomeric material, and at least one fibrous material, preferably ceramic, glass or meta-aramid (poly-m-phenylene isophthalamide). However, without departing from the scope of the invention, other types of layers can also be envisaged. It should be noted that the ceramic fabric layer proves to be extremely effective for the fire-fighting function, while the glass fiber layer makes it possible to increase the rigidity of the layering and limit the flow of the silicone elastomer in a plane orthogonal to the direction of layering, in the event of mechanical action in this direction. Finally, a layer of meta-aramid fibers also provides this increase in stiffness.

Preferably, one or more fibrous layers extend along the entire length of the first contact edge and the end section, just as one or more fibrous layers extend along the entire length of the second contact edge, including in its obturator section.

The object of the invention is also a power plant of an aircraft, containing a bypass gas turbine engine of the aircraft, as well as a strut of the gas turbine engine on the wing element of the aircraft,

wherein the gas turbine engine comprises an intermediate flow compartment located between the primary flow and the secondary flow of the gas turbine engine, as well as a rack passing in the radial direction through the secondary flow and communicating with the intermediate flow compartment, the latter being partially limited radially outward by an upstream ring, connected to the rack by means of two connecting hoods located respectively on both sides of the upstream end of the strut of the attachment in the transverse direction of the power plant,

wherein the upstream end of the strut mount comprises two lateral sides as well as a peripheral support along the contour of the base of this upstream end of the strut.

According to the invention, the propulsion unit also comprises, connected to at least one of the two connecting hoods, the above-described fire-fighting device located between the upstream end of the attachment strut and the connecting hood on which the device is fixed.

Preferably, the first contact end of the first contact edge rests on the circumferential support of the upstream end of the attachment brace, and the second contact end of the second contact edge rests on the corresponding side of the upstream end of the attachment brace.

Preferably, the first curved line is inscribed in a first contact surface substantially flat and substantially parallel with respect to the transverse direction as well as the longitudinal mounting direction, and the second line formed by the second contact edge is straight and substantially parallel to the vertical mounting direction.

Preferably, the second contact edge is stressed between the side of the upstream end of the strut mount and the nacelle cowl movable gasket.

Finally, the propulsion unit also includes a complementary fire-fighting device connected to the other of the two connecting hoods, located between the upstream end of the strut of the mount and the connecting hood, on which the complementary device is fixed, the latter comprising a contact structure in the form of a gasket in the form of a roller, the longitudinal end of which equipped with a connecting pin cooperating with the other longitudinal end of the first contact edge belonging to the fire-fighting device. As mentioned above, this feature indicates that the invention is in the form of connecting the device to another existing device, which is made separately and already installed in the power plant.

Other advantages and features of the invention will become more apparent from the following detailed non-restrictive description.

BRIEF DESCRIPTION OF THE DRAWINGS

This description is presented with reference to the accompanying drawings, in which:

Fig. 1 is a partial schematic perspective view of a power plant according to a preferred embodiment of the invention.

Fig. 2 is a perspective and exploded view of a portion of the power plant shown in FIG. 1.

Fig. 3 is a perspective view of the part shown in the previous figure.

Fig. 4 is a side view of the part shown in the previous figure, with the fire fighting device shown in dotted lines.

Fig. 5 is a sectional view along the line V-V of FIG. 4.

Fig. 6a is a perspective view of the fire fighting device shown in the previous figures.

Fig. 6b is a perspective view similar to the previous one from a different angle.

Fig. 6b' is a perspective view similar to the previous one according to an alternative embodiment.

Fig. 6c is a sectional view along the plane Pc of FIG. 6b passing through the end section.

Fig. 6c' is a sectional view along the plane Pc of FIG. 6b' passing through the end section.

Fig. 6d is a plan view of part of the fire fighting device shown in FIG. 6a and 6b.

Fig. 7 is a perspective view of the part shown in FIG. 2-4 showing a seal line obtained with a fire fighting device.

Fig. 8 is a perspective view of the part shown in FIG. 2-4 showing the second contact edge of the fire fighting device in tension.

Fig. 9 is a sectional view along line IX-IX of FIG. 10.

Fig. 10 is a sectional view along line X-X of FIG. 9.

Fig. 11 illustrates the connection between the fire fighting device shown in the previous figures and a known complementary device.

Fig. 12 is a rear view of a portion of the device connection shown in FIG. eleven.

Fig. 13 is a sectional view similar to the previous figure.

Fig. 14 is a sectional view along the line XIV-XIV of FIG. 13.

Fig. 15 is an enlarged perspective view of a portion of the device shown in FIG. 6a.

Fig. 16 is a bottom view of the device shown in the previous figure.

Fig. 17 is an axial view from the downstream side, in particular showing the second contact edge of the fire-fighting device in a minimum stress state.

Fig. 17a is a perspective view of the device in the same voltage state as in FIG. 17.

Fig. 18 is an axial downstream side view similar to FIG. 17, in particular showing the second contact edge of the fire fighting device in the maximum voltage state.

Fig. 18a is a perspective view of the device in the same voltage state as in FIG. 18.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 shows in part a power plant 100 according to a preferred embodiment of the invention. This installation 100 contains a bypass gas turbine engine 1 for an aircraft, as well as a strut 9 for fastening this gas turbine engine to a wing element (not shown) of the aircraft.

The power plant 100 has a longitudinal direction X corresponding also to the longitudinal direction of the gas turbine engine 1 and the longitudinal direction of the strut 9. The plant 100 also has a transverse direction Y as well as a vertical direction Z corresponding to the height direction. All three directions X, Y and Z are orthogonal to each other and form a rectangular coordinate system.

Preferably, the strut 9 allows the gas turbine engine 1 to be suspended under the wing of the aircraft. This strut contains a structural part designed to transmit forces from the gas turbine engine, and this part is usually referred to as the primary structure or rigid structure. As a rule, it has the shape of a caisson, while in Fig. 1 shows only its upstream end 7. The strut is also equipped with secondary structures (not shown) in the form of aerodynamic fairings.

In the preferred embodiment described and shown, the gas turbine engine is a bypass and twin-cassette turbojet engine. The turbojet 1 has a longitudinal central axis 2 parallel to the X direction around which its various components are arranged. From upstream to downstream in the main flow path 5 of gases through this gas turbine engine, it contains a fan 3, then a gas generator, classically consisting of compressors, a combustion chamber and turbines. These elements of the gas generator are surrounded by a central casing 6, also called the "main" casing, which delimits the intermediate flow compartment 8a radially inwards. This compartment 8a is also delimited radially outward by one or more hoods, wherein in FIG. 1 shows only their upstream ring 10. The upstream ring 10 is located in the downstream extension of the hub 12 of the intermediate housing 14 of the turbojet. The intermediate crankcase 14 also includes an outer shell 16 located in the downstream continuation of the fan crankcase 18. It also contains downstream guide vanes 20 located at the outlet of the fan blades and connecting the hub 12 to the outer shell 16.

The fan housing 18 and the outer shell 16 define together in the radial direction the fan compartment 8b inwardly. This compartment 8b is also delimited radially outward by one or more cowlings (not shown) which are part of the turbojet nacelle. As in the intermediate flow compartment 8a, this compartment 8b houses the aggregates and auxiliaries, as is well known in the prior art.

To connect the two compartments 8a, 8b, one or more posts 22 are provided. For example, two posts 22, which are equipped with a turbojet engine, are located at the so-called positions at 12 o'clock and at 6 o'clock. These posts 22 are hollow and allow, for example, electrical cables and/or pipes to be laid. In particular, these posts connect the downstream part of the outer shell 16 with the upstream ring 10. To do this, they pass through the secondary stream 26, which is partially limited externally by hoods (not shown) located at the outlet of this shell, and partially limited in direction inward by the upstream ring 10 of the intermediate flow compartment 8a. The secondary stream 26 supplements the primary stream 28 which classically passes through the gasifier.

In FIG. 2-5 show a portion of a propulsion unit 100 including the upstream end 7 of the strut 9, the strut 22 at the 12 o'clock position, and the upstream ring 10. In particular, on both sides of the upstream flow end 7 of the strut 9 in the Y direction, connecting hoods 30 are provided, providing an aerodynamic connection between the rack 22 and the upstream ring 10. Each hood is located respectively on both sides of the strut 9. Thus, this assembly is not completely closed by 360 °, but has an angled opening, centered at the 12 o'clock position, at which level two connecting hoods 30 provide connection to the radially inner end of the column 22.

In the figures, the connection between the various elements is shown only on one side of the strut, but, of course, an identical or similar and preferably symmetrical connection is also provided on the other side of the upstream end 7 of the strut 9. Thus, on each side of the strut 9, the connecting hood 30 has an upstream end 32 intended to be located in the downstream extension of the intermediate case hub. Its upper end 33 (in a radially outward direction) is connected to the column wall 22, while its circumferential end 35 is connected to the circumferential end of the upstream ring 10. Finally, its downstream end 38 forms a recess 39 of the annular slot sector type in which the gasket 40 of the nacelle is located, which is preferably installed on the movable hood of the nacelle (not shown in Fig. 2-5). This gasket 40, also referred to as a three-arm or tripod gasket, comprises a nodal point from which extends a first gasket portion 40a pressed against a recess 39, then an inlet ring 10, a second gasket portion 40b pressed against a niche 39, then rack 22, and the third section 40s, pressed against the side 42 of the strut. Each strand of the spacer 40 is tubular, or contains a bead or bead.

The gasket 40 thus occupies the position shown in FIG. 3, after closing the nacelle hood on which it is mounted and which has an outer surface located in the downstream continuation of the outer surface 34 of the connecting hood 30.

The upstream end 7 of the strut 9 has a base 44 from which, in particular, two lateral sides 42 extend. parallel to the X and Y directions and substantially orthogonal to the sides 42. Its main function is to provide a fire barrier between the intermediate flow compartment 8a and the upstream end 7 of the strut. To perform this function, installation 100 includes an inventive fire-fighting device 50 associated with each connection hood 30. fire-fighting device associated with another connecting hood 30.

The two connecting hoods 30 may have identical or similar constructions, being, for example, symmetrical with respect to the longitudinal plane XZ passing through the axle 2. This configuration is shown schematically in FIG. 2, which also shows the connection of two claimed devices 50, which are connected at their upstream end to form together a profile similar to that of the peripheral support 46 against which they are pressed.

With reference to FIG. 2-5, only one of the two devices 50 will be described, the constructions of which are identical or similar, being, for example, symmetrical with respect to the longitudinal plane XZ passing through the axis 2.

Thus, the fire-fighting device 50 is located between the upstream end 7 of the strut and the corresponding connecting hood 30, on which this device is fixed. In general, the 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 support 46, half thereof. This first contact edge 52a prevents a fire originating in the intermediate flow compartment 8a from propagating circumferentially towards the side 42 of the strut or radially outward towards the upstream end side of the strut.

The second contact edge 52b rests on the strut side 42 at the outlet of the two portions 40a, 40b of the nacelle pad 40. It is designed to stop a possible fire in the intermediate flow compartment 8a so that it does not spread axially towards the exit along the side 42 of the strut.

With its edges 52a, 52b, the device 50 is an ingenious and effective solution for providing a fire-fighting function despite the relative movements that may occur between the turbojet and the strut during the various phases of the flight of the aircraft.

In FIG. 5 shows the first low compression edge 52a as a result of the relative position between the turbojet and the strut. This first edge 52a has a C-shaped cross-section, preferably a semi-circular cross-section corresponding to its nominal unstressed shape. Thus, when the first edge 52 is compressed, it has a shape that tends to flatten/ovalize, causing its two circumferential ends 53 to converge in the compression direction corresponding to the Z direction.

One of the two circumferential ends 53 rests on a peripheral support 46 being substantially tangent to this support. The other end 53 is located at the fastening section 56 through which fasteners 54 such as bolts or rivets pass. Indeed, these elements 54 pass through the mounting section 56 of the device 50, as well as through the first bracket 58 of the connecting hood 30, which is located radially inside between the latter and the peripheral support 46. The first bracket 58 has a general U-shape, open laterally outward, while the semicircular first edge 52a is open laterally inward.

Thus, the fastening section 56 extends in the Z direction downwardly parallel to the base U of the bracket 58, connecting with one of the circumferential ends 53 of the semicircular first edge 52a. The flexible connection area between the fastening section 56 and the end 53 is close to the connection area between the base U and its lower branch. Therefore, the upper part of the first edge 52a preferably rests on the lower base of the first U-shaped bracket 58.

Moreover, as shown in cross section in FIG. 5, both circumferential ends 53 of the first edge 52a are preferably inscribed in an imaginary vertical line along which the fastening section 56 extends. This geometry is observed in particular in the relaxed state of the first edge 52a. However, it can be clarified that the design of the fire device 50 allows contact between the first edge 52a and the peripheral support 46 to be maintained during any relative movements that occur between the turbojet and the strut, and in each of the three directions X, Y and Z.

The circumferential end 53 cooperating with the support 46 forms the main part of the first contact end 70a of the device 50 in contact with the strut. This first contact end 70a is supplemented by a small part belonging to the end section 71 shown in FIG. 6a-6d. In this embodiment, the end section 71 is a bead-like section, that is, a tubular section, preferably of circular cross section, the cavity of which is preferably left empty. This section 71 forms, together with the first edge 52a, a contact structure 73 which is to bear on the strut peripheral support 46.

Section 71 is located in the continuation of the downstream longitudinal end 75a of the first edge 52a. In particular, the circular bead section 71 has an upstream end 77a that is open and extends from the downstream longitudinal end 75a of the lip 52a. Therefore, at the level of the transition between the edge 52a and the section 71, formed by the ends 75a, 77a, the contact structure 73 changes from a circular section to a semi-circular section, possibly gradually, but preferably abruptly. In general, regardless of the shape of the edge 52a and the shape of the section 71, the contact structure 73 transitions from a closed section (inside the section 71) to half of this closed section (inside the C-shaped edge 52).

The outer and inner diameters of the two ends 75a, 77a, respectively, are substantially identical. In addition, these diameters are substantially constant along the entire contact structure 73, even if slight fluctuations are encountered, for example in the range of plus or minus 15%.

The downstream end 77b of section 71 is closed. It is convex, for example, in the form of a dome. Due to this closure, as well as the tubular shape of section 71, this downstream part of the contact structure 73 provides a stronger and easier to obtain seal due to the greater transverse extension than the first C-shaped edge 52a extended by this section. In particular, this allows this section 71 to come into contact simultaneously with the peripheral support 46 and with the side 42 of the strut 9.

As mentioned above, the circular section 71 in the form of a roller forms only a minor part of the contact structure 73, namely only its downstream end. Preferably, its length is no more than 20% of the total length of the contact structure 73, and even more preferably less than 15%. In this regard, in FIG. 6b' and 6c' show an alternative embodiment in which the end portion 71 extends only a short length. This portion 71 is not necessarily rolled and can be reduced to a general dome shape, open at its upstream end 77a mating with first edge 52a and closed at its downstream end 77b. In other words, this section 71 is reduced to the domed end of section 71 of the embodiment shown in FIG. 6a-6d. As shown more clearly in FIG. 6c', the radially lower end of the dome section 71 may have a through cutout 55 at the level of the upstream end 77a. This notch 55 provides even more controlled compression deformation of section 71 during power plant operation.

In any envisaged embodiment, as in the case of the edge 52a, the round/domed shape of the section 71 corresponds to its nominal shape as seen in the unstressed state. Thus, after placement on the power plant, this section 71 also undergoes flattening/ovalization, and in each of the three directions X, Y and Z. However, without going beyond the invention, on this section, which is mainly subjected to compression, and other types of deformation.

The first contact edge 52a and the radially lower end of the section 71 together provide a first sealing line on the peripheral support 46. As shown in FIG. 7, this is the first curved line 72a along the profile of the half portion of the support 46 associated with the contact structure. The first contact end 70a of this contact structure 70 (not shown in FIG. 7 but visible in FIGS. 6a and 6b) extends along this first curved line 72a in a general L-shape.

The device 50 also includes the aforementioned second edge, the function of which is to form a second sealing line 72b on the side 42 of the brace 9. Preferably, this second line is straight and substantially parallel to the Z direction. Preferably, both lines 72a, 72b shown in FIG. 7 are connected at the radially inner downstream end of the device 50. If the contact structure and the second edge can be directly adjacent at the level of the end section, they can alternatively be connected via the material transition 79 shown in FIG. 6b, 6b' connecting the closed downstream end 77b of section 71 to the second contact edge 52b.

Further with reference to the same Fig. 6a-6d, 6b' and 6c', a more detailed description of the device 50 follows. These figures show a first curved line 72a along which the first edge 52a and the end section 71 follow one another. The line 72a is inscribed in a substantially flat first contact surface. S1, which corresponds to the radially outer surface of the peripheral support 46. This surface S1 may be strictly flat or may have one or more levels of low height, for example not exceeding a few millimeters. Thus, the surface S1 preferably corresponds to the XY plane of the propulsion unit 100. In addition, the first curved line 72a inscribed in this XY plane has an overall L-shape in which the angle between the base L and the leg L can be rounded and in which the free the end of the branch may also be rounded.

Starting from the edge 52a, upwards in the Z direction extends the fastening section 56 in the form of a plate with through holes 76 made in it, through which the above-mentioned bolts 54 must pass. The through holes 76 can be reinforced with inserts 81 installed on the device 50.

At the level of the downstream longitudinal end 75a of the first edge 52a, or at its inlet, the device 50 includes a support section 60, which also extends upwards essentially along the Z direction, starting from the upper circumferential end 53 of this edge. In particular, this bearing portion 60 is thicker and is located adjacent to a rib 80 intended to increase the mechanical strength of the device 50. The rib 80 is located between the mounting portion 56 and the bearing portion 60 in block form. It also extends upwards in a substantially Z direction, parallel to the attachment portion 56, from which it can be spaced in the direction of the first curved line 72a. The rib 80 has a thickness intermediate between the thickness of the fastening section 56 and the thickness of the support section 60. The same applies to its height in the Z direction.

The support section 60 is designed to accommodate the second edge 52b through the connection zone 62 located therebetween. The connection zone 62 is thin and serves as a hinge connection with the second edge 52b, which preferably remains straight and does not deform or only slightly deform in bending under any level of applied compression. .

The connection zone 62 extends from the support portion 60 in a substantially X direction to the downstream side. At its radially inward end, the connection zone 62 holds the top of the section 71 which is at the inlet of the lip 52b held by the downstream end of this connection zone 62.

The second contact end 70b of the second edge 52b extends along the second line 72b, preferably straight and preferably substantially orthogonal to the first contact surface S1. Thus, the second straight line 72b preferably extends substantially in the Z direction so that the lip 52b comes into contact with the corresponding brace side.

The radially outer end of the assembly formed by elements 60, 62 and 52b is bevelled as shown in FIG. 6b.

In addition, the second contact edge 52b has a thickness that increases from the base 68b shown in FIG. 6a to the second contact end 70b. Therefore, the latter may have a surface, for example in the form of a flat vertical strip. In the relaxed state shown in Fig. 6d, the angle of inclination B0 can be observed between the normal 64b to the lateral side (not shown) of the brace and the second general edge direction 66b defined between the base 68b and the second contact end 70b of the edge 52b.

In the assembled state of the device 50, its second contact edge 52b is exposed in the Y direction from the side of the second nacelle pad portion 40c. As shown in FIG. 8, when the nacelle bonnet 82 (shown only schematically) is closed, the third leg 40c of the gasket 40 connected to this bonnet rests on the second edge 52b. The latter is compressed between the strut side 42 and the third portion 40c of the spacer 40, which causes the edge 52b to rotate along its joint zone 62. Given this rotation, the angle B0 increases compared to the angle observed in the unstressed state in FIG. 6d. The value of this angle B0 depends on the level of compression of the fire fighting device 50, which in turn depends on the amplitude of the relative movements between the turbojet and the strut. In FIG. 8, it can also be seen that the third portion 40c of the gasket 40 is stressed in the Y direction, with the result that its sealing tubular portion is deformed between the nacelle cowl 82 and the edge 52b. Thus, the tubular portion, which has a cross section of a substantially circular shape in an unstressed state, is flattened by stress, taking on, for example, an elliptical, oval, or the like.

In this FIG. 8 also shows that the presence of section 71 significantly limits the leakage section 91 between the strut side 42 and this section, even at high levels of deformation resulting in large values of the angle B0. The provision of such a downstream end, having a shape convex in the downstream side and open in the upstream side, makes it easy to achieve a satisfactory and controlled seal with the strut side 42. Thus, the leakage section 91 remains moderate even if the second edge 52b rotates a lot. In addition, this section 91 is limited by the special shape of the second edge 52b, which will be described below with reference to FIGS. 6a, 6b, 6b', 6c', 15 and 16.

As shown in the same FIG. 8, the support section 60 of the apparatus 50 engages in a second bracket 86 provided on the coupling hood 30 at the level of its downstream end 38 forming the niche 39 shown in FIG. 2. The second bracket 86, shown more clearly in FIG. 7 has openings 88 for receiving elongated fasteners 90 provided on the support portion 60 on the side opposite to the side where the edge 52b and its connecting zone 62 are located. These elongated elements 90 are integral with the device 50 or attached to this device. For example, they are made in the form of pins, the end of which is riveted on the opposite surface of the second bracket 86 through which they pass.

Another feature of the invention is the one-piece manufacturing of the fire fighting device 50. In other words, all of the aforementioned elements of the device 50 are made in a single piece, preferably by injection molding. This one-piece production is not hindered by the presence of the bead section, since it remains open at one of its axial ends and preferably only extends over a short length.

Elongated fasteners 90 can be included in this single piece, while inserts 81 can be considered as separate attachment elements from the device, since they are part of the means of fastening it to the connecting hood 30.

Device 50 can be made as a simple elastomeric block, but preferably the latter is combined with one or more different functional layers.

In the example shown in FIG. 9 and 10, the device 50 is made by superimposing in its thickness direction 92 layers 99 of an elastomeric material, preferably a silicone elastomeric material, and functional fibrous layers 110. The latter may be layers of glass, ceramic or meta-aramid (poly-m -phenylene isophthalamide), which increase the rigidity of the device. Special fire protection layers can then be provided, for example made of ceramic fibre. Preferably, the latter are located in areas of the device most exposed to flame. Since the silicone elastomeric material of the layers 90 degrades and turns into silica in case of high temperature, the webs 110 used allow, thanks to their grid cells, to trap these degrading particles.

The interlacing of layers can also be supplemented with fibrous meta-aramid layers 110 for the same purpose of increasing the rigidity of the entire assembly. One of these layers can even be applied to the outer surface of the edges to limit their wear and damage from contacting parts.

Preferably, the layers 99 and 110 are arranged parallel to each other in accordance with the profile of the device 50. At least one or more of them can extend along the entire height of the device 50 and from one end to the other of the latter in the direction of the aforementioned first curved line 72a.

The device 50 may have a length of 30 to 50 cm in the X direction, while the width of the device 50 in the Y direction is about 10 to 20 cm. Finally, in the Z direction, the maximum height of the device 50 can be about 15 to 20 cm. Each edge 52a, 52b occupies only a few centimeters.

With regard to the fire resistance provided by the device 50, in addition to taking into account the regulatory requirements according to ISO 2685-1998 and AC 20-135, the most severe conditions are taken into account, that is, fire resistance during flight and fire resistance on the ground are provided. In particular, this implies a solution that provides a fire protection function under the following conditions:

- flame temperature: 1100±80°С;

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

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

- duration of the test: 15 minutes, divided into two phases: 5 minutes. : application of increased pressure; and 10 min. : at atmospheric pressure;

- self-extinguishing for a limited time.

In the embodiments described above, two claimed devices 50 are provided associated with a circumferential support 46. The connection between them is exceptionally easy at the level of the upstream longitudinal ends 75b of their respective first edges 52a. Indeed, these two C-shaped ends 75b (of which one is shown in Fig. 6b) can easily overlap each other, thus providing continuity for the fire barrier at the connection zone level between the two devices 50.

However, the invention is also suitable for use in an existing power plant to replace one of the two known devices already in that plant. This functionality is shown in Fig. 11-14, which shows the connection between the claimed device 50 and a complementary fire device 50' of known design. Both devices are respectively designed to be mounted on two connecting hoods 30 of the power plant.

Complementary fire fighting device 50' has a classic design with several elements attached to each other. It generally comprises a bead-like spacer 71' extending substantially the entire length of device 50', the spacer being intended to be pressed against a peripheral strut support like the contact structure 73 of device 50. In the unstressed state shown in FIG. 11-14, the bead-like spacer 71' has a circular section.

Thus, this bead-like spacer 71' forms the contact structure 73' of the complementary device 50' and has an upstream longitudinal end 75b' equipped with a connecting pin 112'. This pin 112' is hollow, also circular with a smaller diameter than the bead, and possibly bevelled at its closed end. With regard to the device 50, the upstream longitudinal end 75b of its first C-section contact edge 52a is ideally suited to interact with this connecting pin 112'. Indeed, the inner diameter of the C-shape can be substantially equal to the outer diameter of the connecting pin 112', which allows the latter to go inside the upstream longitudinal end 75b in the form of C. This overlap, shown in FIG. 12-14 and similar to the fit connection, provides continuity of the fire barrier at the connection level between the new device 50 and the complementary device 50' already installed on the power plant. Thus, thanks to the proposed invention, one of the two existing devices can be easily replaced.

Further with reference to Fig. 6a, 6b, 6b', 6c', 15 and 16 follows a description of the special design of the second edge 52b. It does not end at the level of the material bridge 79, but has at its radially inner end a locking portion 63 protruding along the second line 72b. This protruding portion 63 extends the edge 52b beyond the material bridge 79 in the direction of the first line 72a. Thus, it is located opposite and at a distance from the closed downstream end 77b of the end section 71. In other words, it is located opposite the closed downstream end 77b in the direction of the first line 72a, forming an obstacle to the flame, which could propagate axially to the upstream towards this convex downstream end 77b.

In particular, as shown in FIG. 15 and 16, this lug-shaped locking portion 63 has a geometry that fits into the continuation of the geometry of the rest of the lip 52b. It has a first contact side 63a forming the bottom of a second contact end 70b having a substantially flat geometry to be pressed against the side of the strut. Opposite to the first side, the protruding portion 63 has a second side 63b, which is shaped so as to deflect the flame for its removal laterally from the side of the strut and avoid its penetration into the sensitive area. To do this, the second side 63b moves away from the first contact side 63a as it approaches the closed end 77b, which is convex in the direction of the protruding closure portion 63. Thus, it has a curved shape, for example, with a simple curvature, forming a transverse flame deflection ramp.

The second side 63b is also in a continuous extension of the outer surface of the upper part of the second edge 52b, and this surface is indicated by 69 in FIG. 15. The outer surface 69, also having a curved shape, is intended to be covered by the third section 40c of the gondola gasket. On the other hand, during operation, this nacelle gasket portion 40c does not overlap the protruding portion 63 of the second edge 52b, since this protruding portion 63 extends radially lower than the gasket portion 40c. The invention provides for the closure section 63 to protrude downward along the second line 72b, while its protruding length preferably remains limited and ends indented with respect to the first contact end 70a, that is, indented in the Z direction. This prevents the closure section 63 included in contact with the side of the strut, also come into contact with the peripheral support 46 on which the first contact end 70a rests. The gap 67b between the lower end of the closure portion 63 and the support 46 in the direction of the second line 72b may be between 8 and 13 mm, for example in the order of 11 mm. The protrusion distance 67c of the closure portion 63 can be between 10 mm and 20 mm, for example about 16 mm. Thus, the locking portion 63 preferably ends below the center of the convex closed end 77b in the direction of the second line 72b.

Both sides 63a, 63b are connected at the inlet of the third connecting side 63c of the closure portion 63, forming an axial gap 67a with the closed end 77b. This gap 67a, shown in FIG. 16 may be from 2 to 5 mm, for example, may be about 3.5 mm. The same figure shows that the second side 63b, the gap 67a and the closed end 77b together form a tortuous passage. It greatly reduces the risk of a flame passing through and penetrating the possible aforementioned leakage cross section resulting from the deformation of the closed end 77b of the contact structure.

In FIG. 17, 17a, 18 and 18a, the device 50 is shown in various voltage states on the peripheral support 46. In FIG. 17 and 17a show a minimum stress state in which the leakage cross section 91 between the strut side 42 and the closed end 77b of section 71 at the level of support 46 is at a minimum. In this state, the obstruction portion 63 of the edge 52b may not extend downward enough to form an axial obstruction to the flame directed towards the leakage section 91 adjacent to the support 46. However, this remains without serious consequences, since the very small section 91 observed at this level voltage, reduces the risk of flame penetration into the sensitive brace area. In addition, even at this low voltage level, the closure portion 63 may form an axial obstruction to the flame directed to any other leakage section that may occur along the side 42 of the strut at a distance from the support 46, also as a result of the deformation of the closed end 77b.

In FIG. 18 and 18a show the maximum stress state in which the overlapping of the closed end 77b by the closure portion 63 is optimal. Any leakage section (not shown) between the strut side 42 and the deformed end 77b of section 71 is protected from flame by a shut-off section 63 located axially opposite this section.

Of course, the person skilled in the art can make various changes to the described invention, which is presented solely as a non-limiting example and the scope of which is defined in the attached claims.

Claims (16)

1. Fire-fighting device (50) designed to be installed between the upstream end (7) of the strut (9) for fastening the bypass gas turbine engine (1) of the aircraft and the connecting hood (30) with which this gas turbine engine is equipped, while the said connecting the hood is designed to connect the upstream ring (10), limiting the part of the intermediate flow compartment (8a) radially outward, with the rack (22), passing radially through the secondary flow (26) of the gas turbine engine, characterized in that it contains: a contact structure (73) containing a first contact edge (52a), preferably having a C-shaped section and forming a first contact end (70a), passing along the first line (72a), preferably a curved line, while at one of the longitudinal ends (75a ) the first contact edge (52a), the contact structure also includes an end section (71), one of the ends (77a) of which is open and is in the continuation of the first edge (52a), and the other end (77b) of which is closed; support section (60); And the second contact edge (52b) carried by the support section (60) through the connection zone (62) which carries the end section (71) of the contact structure (73), while the second contact edge (52b) has a second contact end (70b) extending along the second line (72b) different from the first line (72a), while at one of its ends the second contact edge (52b) has a locking section (63) protruding along the second line (72b), while the locking section (63) located at a distance and opposite the closed end (77b) of the end section (71). 2. The device according to claim. 1, characterized in that the locking section (63) has a first contact side (63a), forming part of the second contact end (70b) of the second contact edge (52b), as well as a second side (63b), opposite to the first and moving away from the first contact side (63a), approaching the closed end (77b) of the end section (71), while the second side (63b) is preferably curved. 3. The device according to claim 1 or 2, characterized in that the closed end (77b) of the end section (71) has a convex shape in the direction of the locking section (63) belonging to the second contact edge (52b). 4. Device according to any one of the preceding claims, characterized in that, in the direction of the second line (72b), the closure section (63) ends indented with respect to the first contact end (70a). 5. The device according to any of the previous paragraphs, characterized in that it is a monoblock. 6. Device according to any one of the preceding claims, characterized in that said second line (72b) is straight and preferably substantially orthogonal to the substantially flat first contact surface (S1) into which the first curved line (72a) is inscribed. 7. Device according to any one of the preceding claims, characterized in that it also comprises a fastening section (56) bearing a first contact edge (52a), said fastening section being preferably provided with openings (76) for passage of the fastening elements (54). 8. Power plant (100) for an aircraft, containing a bypass gas turbine engine (1) of the aircraft, as well as a strut (9) for mounting the gas turbine engine on the wing element of the aircraft, while the gas turbine engine (1) contains an intermediate flow compartment (8a) located between the primary flow (28) and the secondary flow (26) of the gas turbine engine, as well as the rack (22) passing in the radial direction through the secondary flow (26) and communicating with an intermediate flow compartment (8a), the latter being partially bounded radially outward by an upstream ring (10) connected to the post by means of two connecting hoods (30) located respectively on both sides of the upstream end (7) strut (9) mountings in the transverse direction (Y) of the power plant, at the same time, the upstream end (7) of the strut of the fastening contains two lateral sides (42), as well as a peripheral support (46) along the contour of the base (44) of this upstream end (7) of the strut, characterized in that the propulsion unit (100) also comprises, connected to at least one of the two connecting hoods (30), a fire-fighting device (50) according to any one of the preceding paragraphs, located between the upstream end (7) of the strut mount and the connecting hood (30) on which the device (50) is fixed. 9. The power plant according to the previous paragraph, characterized in that the first contact end (70a) of the first contact edge (52a) rests on the peripheral support (46) of the upstream end (7) of the strut of the attachment, and in that the second contact end ( 70b) of the second contact edge (52b) rests on the corresponding lateral side (42) of the upstream end (7) of the strut. 10. Power plant according to claim. 8 or 9, characterized in that the first curved line (72a) is inscribed in the first contact surface (S1), essentially flat and essentially parallel with respect to the transverse direction (Y), as well as to the longitudinal direction (X) of the installation (100), and the second line (72b) formed by the second contact edge (52b) is a straight line running essentially parallel to the vertical direction (Z) of the installation.

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