EP2971738A1 - Turbine engine, such as an airplane turbofan or turboprop engine - Google Patents

Turbine engine, such as an airplane turbofan or turboprop engine

Info

Publication number
EP2971738A1
EP2971738A1 EP14715361.3A EP14715361A EP2971738A1 EP 2971738 A1 EP2971738 A1 EP 2971738A1 EP 14715361 A EP14715361 A EP 14715361A EP 2971738 A1 EP2971738 A1 EP 2971738A1
Authority
EP
European Patent Office
Prior art keywords
panel
panels
wall
upstream
downstream
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP14715361.3A
Other languages
German (de)
French (fr)
Inventor
Romain Plante
Jérémy GALIANO
Florent ROGNIN
Gérome SONOIS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran Aircraft Engines SAS
Original Assignee
SNECMA SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SNECMA SAS filed Critical SNECMA SAS
Publication of EP2971738A1 publication Critical patent/EP2971738A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/24—Casings; Casing parts, e.g. diaphragms, casing fastenings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
    • F02C7/04—Air intakes for gas-turbine plants or jet-propulsion plants
    • F02C7/045—Air intakes for gas-turbine plants or jet-propulsion plants having provisions for noise suppression
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02K—JET-PROPULSION PLANTS
    • F02K3/00—Plants including a gas turbine driving a compressor or a ducted fan
    • F02K3/02—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber
    • F02K3/04—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type
    • F02K3/06—Plants including a gas turbine driving a compressor or a ducted fan in which part of the working fluid by-passes the turbine and combustion chamber the plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type with front fan
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2230/00—Manufacture
    • F05D2230/60—Assembly methods
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2250/00—Geometry
    • F05D2250/20—Three-dimensional
    • F05D2250/28—Three-dimensional patterned
    • F05D2250/283—Three-dimensional patterned honeycomb
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/96—Preventing, counteracting or reducing vibration or noise
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B11/00—Connecting constructional elements or machine parts by sticking or pressing them together, e.g. cold pressure welding
    • F16B11/006—Connecting constructional elements or machine parts by sticking or pressing them together, e.g. cold pressure welding by gluing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T50/00—Aeronautics or air transport
    • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft

Definitions

  • Turbomachine such as a turbojet engine or an airplane turboprop engine
  • the present invention relates to a turbomachine, such as a turbojet or an airplane turboprop, comprising a fan casing whose substantially cylindrical wall surrounds in particular the vanes of the fan.
  • the inner surface of a fan casing conventionally comprises annular acoustic insulation panels. These panels generally have an annular honeycomb structure, formed of adjacent cells, whose inner and outer faces are each covered with a skin. These panels are intended to absorb the sound waves generated by the fan of the turbomachine.
  • the housing more particularly comprises an upstream panel, located upstream of the blades of the fan, a median panel, located opposite the blades of the fan, and a downstream panel, located downstream of the blades of the fan.
  • the median panel conventionally comprises a layer of abradable material against which the radially outer ends of the blades are intended to rub in operation.
  • the cells of the honeycomb structure of the upstream panel have a relatively large section and the inner skin of this panel is generally multi-perforated.
  • the median panel generally has smaller section cells than the upstream panel, so as to increase its resistance to mechanical stresses.
  • each panel has denser areas at their upstream and downstream edges. This increase in density is obtained by filling the corresponding cells with a foam which, by polymerizing, provides a high mechanical strength to the relevant edges of the panels.
  • each panel is attached to the annular wall by means of fasteners located at the upstream and downstream portions of each panel.
  • the upstream and median panels are fixed to the annular wall by means of a thermosetting glue film.
  • the heating of the adhesive film may for example be carried out in an autoclave.
  • the adhesive may be a heat-sensitive adhesive capable of fixing the panel on said wall when the glue is heated to a first temperature and able to release the panel when the glue is heated to a second temperature.
  • a heat-sensitive adhesive capable of fixing the panel on said wall when the glue is heated to a first temperature and able to release the panel when the glue is heated to a second temperature.
  • the invention aims in particular to provide a simple, effective and economical solution to this problem.
  • a turbomachine such as a turbojet or an airplane turboprop, comprising a substantially cylindrical wall fan casing surrounding the blades of the fan, and at least two annular sound insulation panels mounted radially to inside said wall, a first panel being mounted upstream of the fan, a second panel being located downstream of the first panel and carrying an inner layer of abradable material located opposite the radially outer ends of the blades of the fan, characterized in that the two annular panels form a single structural assembly.
  • the downstream edge of the first panel is attached to the upstream edge of the second panel, for example by gluing.
  • the two panels thus form a single structural assembly, easier to handle and fix inside the housing wall.
  • the adhesive bonding is easy to implement and does not require the presence of dense areas at the downstream edge of the first panel or at the upstream edge of the second panel.
  • each panel comprises an annular honeycomb structure formed of adjacent cells, the inner and outer surfaces of said annular structure being covered respectively with an inner skin and an outer skin.
  • the cells of the first panel have a larger section than the cells of the second panel.
  • At least a portion of the inner skin of the first panel and / or the second panel has perforations.
  • Such perforations can further improve the sound insulation.
  • the turbomachine may comprise upstream fastening means located at the upstream portion of the first panel, downstream fastening means located at the downstream portion of the second panel, and medial fastening means located at the level of the junction area between the first and second panels, said fixing means for fixing said panels to the housing wall.
  • first panel and the second panel form a single panel.
  • this single panel can be fixed to the casing wall by means of upstream fixing means located at the upstream portion of the panel, and downstream fixing means located at the downstream portion of the panel. sign.
  • first and second panels are formed of a single panel increases the mechanical strength of the latter. It is thus possible to reduce the number of fastening means used and, consequently, the mass of the turbomachine.
  • the panels can also be attached to the housing wall by means of a glue film.
  • the adhesive may be a heat-sensitive adhesive capable of fixing the panel on said wall when the adhesive is at a first temperature and able to release the panel when the adhesive is heated to a second temperature.
  • FIG. 2 is a front view from the upstream of the housing of Figure 1;
  • FIG. 3 is a partial schematic half-view in axial section of an acoustic insulation panel of the fan casing of FIG. 1;
  • FIG. 4 is a view on a larger scale of the detail 4 of FIG. 1, and represents means for fixing an acoustic insulation panel;
  • FIG. 5 is a schematic sectional view along the line V-V of Figure 4.
  • FIG. 6 is a schematic half-view in axial section of a fan casing of a turbomachine according to an embodiment not belonging to the invention
  • Figure 7 is a schematic front view from the upstream of the housing of Figure 6;
  • FIG. 8 is a schematic view of a portion of the adhesive film of the housing of Figures 6 and 7;
  • FIG. 9 is a perspective view of a first and a second panel, glued to each other so as to form a single structural assembly attached to the wall of a fan casing via fastening means according to a first embodiment of the invention
  • FIG. 10 is a view corresponding to FIG. 9, illustrating a second embodiment of the invention in which the first and second panels are formed of a single panel,
  • FIGS 1 1 and 12 are views respectively corresponding to Figures 9 and 10, in which the panels are fixed to the wall of the housing by gluing, according to two embodiments of the invention.
  • FIG. 1 represents a fan casing 10 of a turbomachine, such as a turbojet engine or an airplane turboprop, this casing being part of a nacelle which surrounds the engine of the turbomachine and inside of which rotates a fan which generates a secondary air flow flowing between the nacelle and the engine and forms part of the thrust produced by the turbomachine.
  • a turbomachine such as a turbojet engine or an airplane turboprop
  • the housing 10 comprises a substantially cylindrical wall 12 which has at its longitudinal ends annular flanges 14, 16 for fixing.
  • the downstream flange 14 is fixed by screw-nut means to a flange (not shown) of an intermediate casing and the upstream flange 16 is fixed by screw-nut means to a flange (not shown) of an air intake sleeve in the nacelle.
  • the casing comprises annular panels 18, 20, 22 of sound insulation which cover the inner cylindrical surface of the wall 12 and which are fixed to this wall.
  • the wall 12 carries three annular panels 18, 20, 22, two panels 18, 20 monoblock respectively upstream and median, and a downstream panel 22 which is sectored.
  • the downstream panel 22 comprises panel sectors which are arranged circumferentially end to end and which are fixed on the wall 12 by screws 24 passing radially through the sectors and engaged in openings in the wall 12.
  • the annular panels 18, 20 are monobloc (that is to say non-sectored) and are fixed on the wall 12 by a technology that allows the disassembly of the panels, especially under the wing of an aircraft during a flight. maintenance operation.
  • Panels 18, 20 have denser zones 62 at their upstream and downstream edges. This increase in density is obtained by filling the corresponding cells with a foam which, by polymerizing, provides a high mechanical strength to the relevant edges of the panels.
  • the panels 18, 20 are mounted inside the wall 12 and fixed to this wall by means of the screw-nut type, each panel comprising lugs 26 of axial support. and radial on tabs 28 of the wall 12, these tabs having through holes means 32 of the screw-nut type.
  • FIG. 3 represents an exemplary embodiment of a panel 18, 20 having an annular honeycomb structure 34 whose inner and outer faces are each covered with a skin 36, 38 laminated, the inner skin 36 having multiperforations 40.
  • the panel may further comprise a layer of abradable material, in particular in the zone of the panel surrounding the fan blades, as is the case of the panel 20 which comprises under its inner skin 36 an inner layer 42 of abradable material (figure 1 ).
  • the cells 64 of the honeycomb structure of the panel 18 have a relatively large section.
  • the panel 20 generally has cells of smaller section than the panel 18, so as to increase its resistance to mechanical stresses generated in particular by the friction of the radially outer ends of the vanes against the layer of abradable material 42.
  • each panel 18, 20 is formed in one piece without discontinuity, the tabs 26 being fixed to the outer skin 38 of the panel and being located in an annular space 40 extending between the panel 18 , 20 and the wall 12.
  • This annular space 40 may have a thickness or radial dimension of the order of 10 mm.
  • Each panel 18, 20 is equipped with two annular rows of tabs, an upstream row of tabs 26, 28 and a downstream row of tabs 26 ', 28'.
  • the legs of each row are regularly distributed around the longitudinal axis of the housing and are diametrically opposed two by two.
  • the tabs 26, 28 of the upstream row are further angularly offset tabs 26 ', 28' of the downstream row, relative to the longitudinal axis of the housing ( Figure 2).
  • Each row comprises for example twelve tabs 26, 26 ', 28, 28'.
  • the tabs 26 carried by the panel 18, 20 have a substantially L-shaped shape and each comprise a longitudinal portion 42 applied to the outer skin 38 of the panel and fixed to this skin by screws 43 cooperating with crimped nuts of the self-braking type ( Figure 5).
  • This longitudinal portion 42 has a cylinder-shaped portion and matches the outer shape of the panel.
  • the portion 42 of the tab 26 is connected at one of its longitudinal ends to a substantially radial portion 44 which extends outwards and which comprises a through-hole through which the screw 32 passes.
  • the portion 42 of the tab 26 comprises a radially outer bearing surface 46 of cylindrical shape and the radial portion 44 comprises a radial bearing surface 48.
  • the portion 44 of the tab 26 has a circumferential dimension smaller than that of its portion 42.
  • the legs 28 carried by the wall 1 2 each comprise a substantially planar radially outer portion 50 applied to the radially inner surface of the wall 12 and fixed thereto by screws 52 cooperating with crimped nuts of the self-braking type, and a part 54 extending radially inwards and which comprises a through hole aligned with the orifice of the lug 26 for the passage of the screw 32 for fixing these tabs.
  • This portion 54 comprises a radial bearing surface 56 on the radial surface 48 of the lug 26 and a planar or substantially cylindrical bearing surface 58 on the cylindrical surface 46 of the lug 26.
  • the portion 54 of the tab 28 has a circumferential dimension less than that of its portion 50. Moreover, the portion 50 of the tab 28 is partly engaged in a recess 60 of shape complementary to the wall 12.
  • the panels 18, 20 previously described may be mounted within the wall 12 of the housing as follows.
  • Each panel 18, 20 is disposed upstream of the wall 12, coaxially with it, and is angularly positioned around the longitudinal axis of the housing so that its lugs 26, 26 'are aligned axially with those 28, 28' crankcase. The panel is then moved in axial translation downstream until it is housed inside the wall 12 and that its lugs 26, 26 'are axially supported on those 28, 28' of the housing.
  • a tool such as a ratchet equipped with an extension is then used to screw the screws 32 in the tabs to secure the panel to the housing.
  • This tool is inserted axially from upstream in the annular space 40 extending between the panel and the wall.
  • such an embodiment requires the use of many fastening means 26, 28, 26 ', 28', 32, which increases the mass of the assembly. Furthermore, the presence of dense areas 62 at the panels 18, 20 is also detrimental in terms of mass. Finally, the number of panels to mount and fix inside the wall 12 of the housing is important, which is long and tedious.
  • FIG. 6 to 8 illustrate an embodiment not belonging to the invention.
  • This embodiment differs from that described above in that the panels 18, 20 (sectored or monobloc) are fixed by a adhesive film 66 on the inner surface of the wall 12.
  • the adhesive film 66 is heat-sensitive. Indeed, it is able to fix the panels 18, 20 on said wall 12 when the glue is at a first temperature and able to release the panels 18, 20 of said wall 12 when the glue is heated to a second temperature. Such an adhesive film 66 thus allows easy disassembly and assembly of the panels 18, 20.
  • This film 66 comprises a conductive wire 68, for example based on carbon, whose ends 70, 72 are connected to the terminals of a power supply.
  • the wire 68 is embedded in the polymer matrix formed by the adhesive film 66.
  • the passage of an electric current in the wire 68 causes it to overheat.
  • the wire 68 can be arranged in a serpentine and extend over the entire surface of the film 66.
  • the adhesive film 66 In normal operation, the adhesive film 66 is subjected to low temperatures. In this case, the film 66 performs its function of fixing the panels 18, 20 on the wall 12.
  • Such an embodiment thus facilitates the repair of a fan casing 10, since it allows the quick and easy disassembly of the panels 18, 20, in particular in the event of maintenance under the wing of an aircraft (this is ie without removing the engine). Such an embodiment also applies to the case of mounting panels 18, 20 at the factory.
  • the invention proposes a turbomachine in which the two annular panels 18, 20 form one and the same structural assembly.
  • the invention proposes to bond the downstream edge of the panel 18 to the upstream edge of the panel 20.
  • the corresponding glue film is referenced 74.
  • the cells 64 of the panel 18 have a larger section than the cells 64 of the second panel 20.
  • edges of the panels 18, 20 intended to be glued to each other do not necessarily include dense areas 62. Only the upstream edge of the panel 18 and the downstream edge of the panel 20 then comprise a dense area 62.
  • the assembly formed of the panels 18, 20 comprises upstream fastening means 26, located at the upstream portion of the panel 18, downstream fastening means 26 ', located at the downstream portion of the panel 20, and the median fastening means 26 ", located at the junction zone 74 between the panels 18, 20, said fastening means 26, 26 ', 26" for fixing said panels 18, 20 to the wall 12 of the housing.
  • FIG. 10 illustrates a second embodiment of the invention, in which a single panel 76 provides both the function of the panel 18 and the function of the panel 20.
  • This panel 76 has dimensions similar to those of the formed assembly by panels 18 and 20 in Figure 9. It supports, as before, a layer of abradable material 42 and has dense areas 62 at its edges upstream and downstream.
  • the panel 76 has a structure similar to that of the panels 18, 20, the cells 64 all having the same section. Of course, it is possible to vary the section of the cells depending on their position in the panel 76, if the mechanical stresses involved require it.
  • the panel 76 comprises upstream fixing means 26 situated at the upstream portion of the panel 76, and downstream fixing means 26 'located at the downstream portion of the panel 76.
  • FIG. 11 illustrates a third embodiment similar to that of FIG. 9, in which the panels 18 and 20 are fixed to the wall 1 2 of the casing with the aid of a glue film 66 (not shown in FIG. Figure 1 1) similar to that described with reference to Figures 6 to 8.
  • FIG. 12 illustrates a third embodiment similar to that of FIG. 10, in which the panel 76 is fixed on the wall 1 2 of the casing with the aid of an adhesive film 66 (not shown in FIG. Figure 12) similar to that described with reference to Figures 6 to 8.
  • the mass of the assembly is reduced by comparison with the prior art, either by the reduced number of dense areas 62 or by the reduced number of fixing means. Furthermore, the fact of having a single structural assembly, providing the same functions as the panels 18 and 20 of the prior art, facilitates its assembly and disassembly.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

The invention relates to a turbine engine, such as an airplane turbofan or turboprop engine, including a blower casing (10) having a substantially cylindrical wall (12) surrounding the blades of the blower, and at least two annular acoustic insulation panels (18, 20) mounted radially inside said wall (12), a first panel (18) being mounted upstream from the blower, a second panel (20) being located downstream from the first panel (18) and supporting an inner layer (42) made of an abradable material, facing the radially external ends of the blades of the blower, characterized in that the two annular panels (18, 20) form a single structural unit.

Description

Turbomachine, telle qu'un turboréacteur ou un turbopropulseur d'avion  Turbomachine, such as a turbojet engine or an airplane turboprop engine
La présente invention concerne une turbomachine, telle qu'un turboréacteur ou un turbopropulseur d'avion, comprenant un carter de soufflante dont une paroi sensiblement cylindrique entoure notamment les aubes de la soufflante. The present invention relates to a turbomachine, such as a turbojet or an airplane turboprop, comprising a fan casing whose substantially cylindrical wall surrounds in particular the vanes of the fan.
La surface interne d'un carter de soufflante comporte classiquement des panneaux annulaires d'isolation acoustique. Ces panneaux ont en général une structure annulaire en nid d'abeille, formée d'alvéoles adjacentes, dont les faces interne et externe sont chacune recouvertes d'une peau. Ces panneaux sont destinés à absorber les ondes sonores générées par la soufflante de la turbomachine.  The inner surface of a fan casing conventionally comprises annular acoustic insulation panels. These panels generally have an annular honeycomb structure, formed of adjacent cells, whose inner and outer faces are each covered with a skin. These panels are intended to absorb the sound waves generated by the fan of the turbomachine.
Le carter comporte plus particulièrement un panneau amont, situé en amont des aubes de la soufflante, un panneau médian, situé en regard des aubes de la soufflante, et un panneau aval, situé en aval des aubes de la soufflante. Le panneau médian comporte classiquement une couche de matériau abradable contre laquelle les extrémités radialement externes des aubes sont destinées à frotter en fonctionnement.  The housing more particularly comprises an upstream panel, located upstream of the blades of the fan, a median panel, located opposite the blades of the fan, and a downstream panel, located downstream of the blades of the fan. The median panel conventionally comprises a layer of abradable material against which the radially outer ends of the blades are intended to rub in operation.
Afin d'améliorer le traitement acoustique en amont de la soufflante, les alvéoles de la structure en nid d'abeille du panneau amont ont une section relativement importante et la peau interne de ce panneau est généralement multiperforée. Le panneau médian a généralement des alvéoles de section plus faible que le panneau amont, de façon à augmenter sa résistance aux sollicitations mécaniques.  In order to improve the acoustic treatment upstream of the fan, the cells of the honeycomb structure of the upstream panel have a relatively large section and the inner skin of this panel is generally multi-perforated. The median panel generally has smaller section cells than the upstream panel, so as to increase its resistance to mechanical stresses.
D'une manière générale, tous les panneaux comportent des zones plus denses au niveau de leurs bords amont et aval. Cette augmentation de densité est obtenue en remplissant les alvéoles correspondantes à l'aide d'une mousse qui, en se polymérisant, apporte une grande résistance mécanique aux bords concernés des panneaux. Selon une première forme de réalisation de l'art antérieur, décrite notamment dans les demandes de brevet FR 12/60493 et FR 12/60495 non encore publiées de la Demanderesse, chaque panneau est fixé à la paroi annulaire par l'intermédiaire de moyens de fixation situés au niveau des parties amont et aval de chaque panneau. In general, all panels have denser areas at their upstream and downstream edges. This increase in density is obtained by filling the corresponding cells with a foam which, by polymerizing, provides a high mechanical strength to the relevant edges of the panels. According to a first embodiment of the prior art, described in particular in the patent applications FR 12/60493 and FR 12/60495 not yet published by the Applicant, each panel is attached to the annular wall by means of fasteners located at the upstream and downstream portions of each panel.
Une telle forme de réalisation nécessite l'utilisation de nombreux moyens de fixation, ce qui augmente la masse de l'ensemble.  Such an embodiment requires the use of many fastening means, which increases the mass of the assembly.
Selon une seconde forme de réalisation de l'art antérieur, les panneaux amont et médian sont fixés à la paroi annulaire par l'intermédiaire d'un film de colle thermodurcissable. Le chauffage du film de colle peut par exemple être réalisé dans un autoclave.  According to a second embodiment of the prior art, the upstream and median panels are fixed to the annular wall by means of a thermosetting glue film. The heating of the adhesive film may for example be carried out in an autoclave.
En variante, la colle peut être une colle thermosensible apte à fixer le panneau sur ladite paroi lorsque la colle est chauffée à une première température et apte à libérer le panneau lorsque la colle est chauffée à une seconde température. Une telle variante permet un montage et un démontage aisés des panneaux.  Alternatively, the adhesive may be a heat-sensitive adhesive capable of fixing the panel on said wall when the glue is heated to a first temperature and able to release the panel when the glue is heated to a second temperature. Such a variant allows easy assembly and disassembly of the panels.
Dans ces cas toutefois, le nombre de panneaux à monter à l'intérieur de la paroi du carter reste important, ce qui est relativement fastidieux.  In these cases, however, the number of panels to be mounted inside the crankcase wall remains large, which is relatively tedious.
En outre, pour chacune des formes de réalisation précitées, le nombre important de panneaux conjugué au fait que chaque panneau comporte des zones denses au niveau de ses bords amont et aval est également préjudiciable en terme de masse.  In addition, for each of the aforementioned embodiments, the large number of panels combined with the fact that each panel has dense areas at its upstream and downstream edges is also detrimental in terms of mass.
L'invention a notamment pour but d'apporter une solution simple, efficace et économique à ce problème.  The invention aims in particular to provide a simple, effective and economical solution to this problem.
A cet effet, elle propose une turbomachine, telle qu'un turboréacteur ou un turbopropulseur d'avion, comprenant un carter de soufflante à paroi sensiblement cylindrique entourant les aubes de la soufflante, et au moins deux panneaux annulaires d'isolation acoustique montés radialement à l'intérieur de ladite paroi, un premier panneau étant monté en amont de la soufflante, un second panneau étant situé en aval du premier panneau et portant une couche interne en matériau abradable située en regard des extrémités radialement externes des aubes de la soufflante, caractérisée en ce que les deux panneaux annulaires forment un seul ensemble structurel. For this purpose, it proposes a turbomachine, such as a turbojet or an airplane turboprop, comprising a substantially cylindrical wall fan casing surrounding the blades of the fan, and at least two annular sound insulation panels mounted radially to inside said wall, a first panel being mounted upstream of the fan, a second panel being located downstream of the first panel and carrying an inner layer of abradable material located opposite the radially outer ends of the blades of the fan, characterized in that the two annular panels form a single structural assembly.
De cette manière, le nombre de panneaux distincts structurellement est réduit, ce qui facilite le montage et la fixation de l'ensemble. Par ailleurs, compte tenu de ce nombre réduit de panneaux distincts, il est également possible de réduire le nombre de moyens de fixation ainsi que le nombre de zones denses, de façon à obtenir un gain important en termes de masse.  In this way, the number of structurally distinct panels is reduced, which facilitates assembly and fixing of the assembly. Furthermore, given this reduced number of separate panels, it is also possible to reduce the number of fastening means and the number of dense areas, so as to obtain a significant gain in terms of mass.
Selon une forme de réalisation de l'invention, le bord aval du premier panneau est fixé au bord amont du second panneau, par exemple par collage.  According to one embodiment of the invention, the downstream edge of the first panel is attached to the upstream edge of the second panel, for example by gluing.
Les deux panneaux forment ainsi un ensemble structurel unique, plus facile à manipuler et à fixer à l'intérieur de la paroi du carter.  The two panels thus form a single structural assembly, easier to handle and fix inside the housing wall.
La fixation par collage est aisée à mettre en œuvre et ne nécessite pas la présence de zones denses au niveau du bord aval du premier panneau ou au niveau du bord amont du second panneau.  The adhesive bonding is easy to implement and does not require the presence of dense areas at the downstream edge of the first panel or at the upstream edge of the second panel.
Avantageusement, chaque panneau comporte une structure annulaire en nid d'abeille formée d'alvéoles adjacentes, les surfaces interne et externe de ladite structure annulaire étant recouvertes respectivement d'une peau interne et d'une peau externe.  Advantageously, each panel comprises an annular honeycomb structure formed of adjacent cells, the inner and outer surfaces of said annular structure being covered respectively with an inner skin and an outer skin.
Dans ce cas, les alvéoles du premier panneau ont une section plus importante que les alvéoles du second panneau.  In this case, the cells of the first panel have a larger section than the cells of the second panel.
Ceci permet d'améliorer le traitement acoustique en amont de la soufflante, tout en garantissant une grande résistance mécanique au niveau de la partie supportant la couche d'abradable, cette partie pouvant être soumises à des sollicitations mécaniques et/ou thermiques importantes. Selon une caractéristique de l'invention, au moins une partie de la peau interne du premier panneau et/ou du second panneau comporte des perforations. This improves the acoustic treatment upstream of the blower, while ensuring a high mechanical strength at the portion supporting the abradable layer, this part may be subjected to significant mechanical and / or thermal stress. According to a feature of the invention, at least a portion of the inner skin of the first panel and / or the second panel has perforations.
De telles perforations permettent d'améliorer encore l'isolation acoustique.  Such perforations can further improve the sound insulation.
En outre, la turbomachine peut comporter des moyens de fixation amont, situés au niveau de la partie amont du premier panneau, des moyens de fixation aval, situés au niveau de la partie aval du second panneau, et des moyens de fixation médians, situés au niveau de la zone de jonction entre les premier et second panneaux, lesdits moyens de fixation permettant la fixation desdits panneaux à la paroi du carter.  In addition, the turbomachine may comprise upstream fastening means located at the upstream portion of the first panel, downstream fastening means located at the downstream portion of the second panel, and medial fastening means located at the level of the junction area between the first and second panels, said fixing means for fixing said panels to the housing wall.
Selon un autre mode de réalisation, le premier panneau et le second panneau forment un seul et même panneau.  In another embodiment, the first panel and the second panel form a single panel.
Dans ce cas, ce panneau unique peut être fixé à la paroi du carter à l'aide de moyens de fixation amont, situés au niveau de la partie amont du panneau, et de moyens de fixation aval, situés au niveau de la partie aval du panneau.  In this case, this single panel can be fixed to the casing wall by means of upstream fixing means located at the upstream portion of the panel, and downstream fixing means located at the downstream portion of the panel. sign.
En effet, le fait que les premier et second panneaux soient formés d'un seul et même panneau augmente la résistance mécanique de ce dernier. Il est ainsi possible de réduire le nombre de moyens de fixation utilisé et, par conséquent, la masse de la turbomachine.  Indeed, the fact that the first and second panels are formed of a single panel increases the mechanical strength of the latter. It is thus possible to reduce the number of fastening means used and, consequently, the mass of the turbomachine.
Les panneaux peuvent également être fixés à la paroi du carter par l'intermédiaire d'un film de colle.  The panels can also be attached to the housing wall by means of a glue film.
Dans ce cas, la colle peut être une colle thermosensible apte à fixer le panneau sur ladite paroi lorsque la colle est à une première température et apte à libérer le panneau lorsque la colle est chauffée à une seconde température.  In this case, the adhesive may be a heat-sensitive adhesive capable of fixing the panel on said wall when the adhesive is at a first temperature and able to release the panel when the adhesive is heated to a second temperature.
L'invention sera mieux comprise et d'autres détails, caractéristiques et avantages de l'invention apparaîtront à la lecture de la description suivante faite à titre d'exemple non limitatif en référence aux dessins annexés dans lesquels : - la figure 1 est une demi-vue schématique en coupe axiale d'un carter de soufflante d'une turbomachine selon une première forme de réalisation de l'art antérieur ; The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example with reference to the accompanying drawings in which: - Figure 1 is a schematic half-view in axial section of a fan casing of a turbomachine according to a first embodiment of the prior art;
- la figure 2 est une vue de face depuis l'amont du carter de la figure 1 ;  - Figure 2 is a front view from the upstream of the housing of Figure 1;
- la figure 3 est une demi-vue schématique partielle en coupe axiale d'un panneau d'isolation acoustique du carter de soufflante de la figure 1 ;  FIG. 3 is a partial schematic half-view in axial section of an acoustic insulation panel of the fan casing of FIG. 1;
- la figure 4 est une vue à plus grande échelle du détail l4 de la figure 1 , et représente des moyens de fixation d'un panneau d'isolation acoustique ; FIG. 4 is a view on a larger scale of the detail 4 of FIG. 1, and represents means for fixing an acoustic insulation panel;
- la figure 5 est une vue schématique en coupe selon la ligne V- V de la figure 4 ;  - Figure 5 is a schematic sectional view along the line V-V of Figure 4;
- la figure 6 est une demi-vue schématique en coupe axiale d'un carter de soufflante d'une turbomachine selon une forme de réalisation n'appartenant pas à l'invention ;  - Figure 6 is a schematic half-view in axial section of a fan casing of a turbomachine according to an embodiment not belonging to the invention;
- la figure 7 est une vue schématique de face depuis l'amont du carter de la figure 6 ;  - Figure 7 is a schematic front view from the upstream of the housing of Figure 6;
- la figure 8 est une vue schématique d'une partie du film de colle du carter des figures 6 et 7;  - Figure 8 is a schematic view of a portion of the adhesive film of the housing of Figures 6 and 7;
- la figure 9 une vue en perspective d'un premier et d'un second panneaux, collés l'un à l'autre de manière à former un seul ensemble structurel fixé à la paroi d'un carter de soufflante par l'intermédiaire de moyens de fixation, conformément à une première forme de réalisation de l'invention,  - Figure 9 is a perspective view of a first and a second panel, glued to each other so as to form a single structural assembly attached to the wall of a fan casing via fastening means according to a first embodiment of the invention,
- la figure 10 est une vue correspondant à la figure 9, illustrant une seconde forme de réalisation de l'invention dans laquelle les premier et second panneaux sont formés d'un seul et même panneau,  FIG. 10 is a view corresponding to FIG. 9, illustrating a second embodiment of the invention in which the first and second panels are formed of a single panel,
- les figures 1 1 et 12 sont des vues correspondant respectivement aux figures 9 et 10, dans lesquelles les panneaux sont fixés à la paroi du carter par collage, conformément à deux variantes de réalisation de l'invention. - Figures 1 1 and 12 are views respectively corresponding to Figures 9 and 10, in which the panels are fixed to the wall of the housing by gluing, according to two embodiments of the invention.
Les figures 1 à 5 illustrent une première forme de réalisation de l'art antérieur, connue de la demande de brevet FR 12/60495 au nom de la Demanderesse. En particulier, la figure 1 représente un carter de soufflante 10 d'une turbomachine, telle qu'un turboréacteur ou un turbopropulseur d'avion, ce carter faisant partie d'une nacelle qui entoure le moteur de la turbomachine et à l'intérieur de laquelle tourne une soufflante qui génère un flux d'air secondaire qui s'écoule entre la nacelle et le moteur et forme une partie de la poussée produite par la turbomachine.  Figures 1 to 5 illustrate a first embodiment of the prior art, known from the patent application FR 12/60495 in the name of the Applicant. In particular, FIG. 1 represents a fan casing 10 of a turbomachine, such as a turbojet engine or an airplane turboprop, this casing being part of a nacelle which surrounds the engine of the turbomachine and inside of which rotates a fan which generates a secondary air flow flowing between the nacelle and the engine and forms part of the thrust produced by the turbomachine.
Le carter 10 comprend une paroi 12 sensiblement cylindrique qui comporte à ses extrémités longitudinales des brides annulaires 14, 16 de fixation. La bride aval 14 est fixée par des moyens du type vis-écrou à une bride (non représentée) d'un carter intermédiaire et la bride amont 16 est fixée par des moyens du type vis-écrou à une bride (non représentée) d'une manche d'entrée d'air dans la nacelle.  The housing 10 comprises a substantially cylindrical wall 12 which has at its longitudinal ends annular flanges 14, 16 for fixing. The downstream flange 14 is fixed by screw-nut means to a flange (not shown) of an intermediate casing and the upstream flange 16 is fixed by screw-nut means to a flange (not shown) of an air intake sleeve in the nacelle.
Le carter comprend des panneaux annulaires 18, 20, 22 d'isolation acoustique qui recouvrent la surface cylindrique interne de la paroi 12 et qui sont fixés à cette paroi.  The casing comprises annular panels 18, 20, 22 of sound insulation which cover the inner cylindrical surface of the wall 12 and which are fixed to this wall.
Dans l'exemple représenté, la paroi 12 porte trois panneaux annulaires 18, 20, 22, deux panneaux 18, 20 monoblocs, respectivement amont et médian, et un panneau 22 aval qui est sectorisé.  In the example shown, the wall 12 carries three annular panels 18, 20, 22, two panels 18, 20 monoblock respectively upstream and median, and a downstream panel 22 which is sectored.
Le panneau aval 22 comprend des secteurs de panneau qui sont disposés circonférentiellement bout à bout et qui sont fixés sur la paroi 12 par des vis 24 traversant radialement les secteurs et engagées dans des orifices de la paroi 12.  The downstream panel 22 comprises panel sectors which are arranged circumferentially end to end and which are fixed on the wall 12 by screws 24 passing radially through the sectors and engaged in openings in the wall 12.
Les panneaux 18, 20 annulaires sont monoblocs (c'est-à-dire non sectorisés) et sont fixés sur la paroi 12 par une technologie qui autorise le démontage des panneaux, en particulier sous l'aile d'un avion lors d'une opération de maintenance. Les panneaux 18, 20 comportent des zones 62 plus denses au niveau de leurs bords amont et aval. Cette augmentation de densité est obtenue en remplissant les alvéoles correspondantes à l'aide d'une mousse qui, en se polymérisant, apporte une grande résistance mécanique aux bords concernés des panneaux. The annular panels 18, 20 are monobloc (that is to say non-sectored) and are fixed on the wall 12 by a technology that allows the disassembly of the panels, especially under the wing of an aircraft during a flight. maintenance operation. Panels 18, 20 have denser zones 62 at their upstream and downstream edges. This increase in density is obtained by filling the corresponding cells with a foam which, by polymerizing, provides a high mechanical strength to the relevant edges of the panels.
Dans l'exemple représenté aux figures 1 à 5, les panneaux 18, 20 sont montés à l'intérieur de la paroi 12 et fixés à cette paroi par des moyens du type vis-écrou, chaque panneau comportant des pattes 26 d'appui axial et radial sur des pattes 28 de la paroi 12, ces pattes comportant des orifices de passage des moyens 32 du type vis-écrou.  In the example shown in FIGS. 1 to 5, the panels 18, 20 are mounted inside the wall 12 and fixed to this wall by means of the screw-nut type, each panel comprising lugs 26 of axial support. and radial on tabs 28 of the wall 12, these tabs having through holes means 32 of the screw-nut type.
La figure 3 représente un exemple de réalisation d'un panneau 18, 20 comportant une structure annulaire 34 en nid d'abeille dont les faces interne et externe sont chacune recouvertes d'une peau 36, 38 stratifiée, la peau interne 36 comportant des multiperforations 40. Le panneau peut en outre comprendre une couche de matériau abradable, en particulier dans la zone du panneau entourant les aubes de soufflante, comme c'est le cas du panneau 20 qui comprend sous sa peau interne 36 une couche interne 42 en matériau abradable (figure 1 ).  FIG. 3 represents an exemplary embodiment of a panel 18, 20 having an annular honeycomb structure 34 whose inner and outer faces are each covered with a skin 36, 38 laminated, the inner skin 36 having multiperforations 40. The panel may further comprise a layer of abradable material, in particular in the zone of the panel surrounding the fan blades, as is the case of the panel 20 which comprises under its inner skin 36 an inner layer 42 of abradable material (figure 1 ).
Afin d'améliorer encore le traitement acoustique en amont de la soufflante, les alvéoles 64 de la structure en nid d'abeilles du panneau 18 ont une section relativement importante. Le panneau 20 a généralement des alvéoles de section plus faible que le panneau 18, de façon à augmenter sa résistance aux sollicitations mécaniques générées notamment par le frottement des extrémités radialement externes des aubes contre la couche de matériau abradable 42.  In order to further improve the acoustic treatment upstream of the blower, the cells 64 of the honeycomb structure of the panel 18 have a relatively large section. The panel 20 generally has cells of smaller section than the panel 18, so as to increase its resistance to mechanical stresses generated in particular by the friction of the radially outer ends of the vanes against the layer of abradable material 42.
Comme cela est visible en figure 2, chaque panneau 18, 20 est formé d'une seule pièce sans discontinuité, les pattes 26 étant fixées sur la peau externe 38 du panneau et étant situées dans un espace annulaire 40 s'étendant entre le panneau 18, 20 et la paroi 12. Cet espace annulaire 40 peut avoir une épaisseur ou dimension radiale de l'ordre de 10 mm. Chaque panneau 18, 20 est équipé de deux rangées annulaires de pattes, une rangée amont de pattes 26, 28 et une rangée aval de pattes 26', 28'. Les pattes de chaque rangée sont régulièrement réparties autour de l'axe longitudinal du carter et sont diamétralement opposées deux à deux. Les pattes 26, 28 de la rangée amont sont en outre décalées angulairement des pattes 26', 28' de la rangée aval, par rapport à l'axe longitudinal du carter (figure 2). Chaque rangée comprend par exemple douze pattes 26, 26', 28, 28'. As can be seen in FIG. 2, each panel 18, 20 is formed in one piece without discontinuity, the tabs 26 being fixed to the outer skin 38 of the panel and being located in an annular space 40 extending between the panel 18 , 20 and the wall 12. This annular space 40 may have a thickness or radial dimension of the order of 10 mm. Each panel 18, 20 is equipped with two annular rows of tabs, an upstream row of tabs 26, 28 and a downstream row of tabs 26 ', 28'. The legs of each row are regularly distributed around the longitudinal axis of the housing and are diametrically opposed two by two. The tabs 26, 28 of the upstream row are further angularly offset tabs 26 ', 28' of the downstream row, relative to the longitudinal axis of the housing (Figure 2). Each row comprises for example twelve tabs 26, 26 ', 28, 28'.
Les pattes 26 portées par le panneau 18, 20 ont une forme sensiblement en L et comprennent chacune une partie longitudinale 42 appliquée sur la peau externe 38 du panneau et fixée à cette peau par des vis 43 coopérant avec des écrous sertis du type auto-freinant (figure 5). Cette partie longitudinale 42 a une forme en portion de cylindre et épouse la forme extérieure du panneau.  The tabs 26 carried by the panel 18, 20 have a substantially L-shaped shape and each comprise a longitudinal portion 42 applied to the outer skin 38 of the panel and fixed to this skin by screws 43 cooperating with crimped nuts of the self-braking type (Figure 5). This longitudinal portion 42 has a cylinder-shaped portion and matches the outer shape of the panel.
La partie 42 de la patte 26 est reliée à l'une de ses extrémités longitudinales à une partie 44 sensiblement radiale qui s'étend vers l'extérieur et qui comprend un orifice traversant de passage de la vis 32.  The portion 42 of the tab 26 is connected at one of its longitudinal ends to a substantially radial portion 44 which extends outwards and which comprises a through-hole through which the screw 32 passes.
La partie 42 de la patte 26 comprend une surface radialement externe 46 d'appui de forme cylindrique et la partie radiale 44 comprend une surface radiale 48 d'appui.  The portion 42 of the tab 26 comprises a radially outer bearing surface 46 of cylindrical shape and the radial portion 44 comprises a radial bearing surface 48.
Comme cela est visible en figure 5, la partie 44 de la patte 26 a une dimension circonférentielle inférieure à celle de sa partie 42.  As can be seen in FIG. 5, the portion 44 of the tab 26 has a circumferential dimension smaller than that of its portion 42.
Les pattes 28 portées par la paroi 1 2 comprennent chacune une partie 50 radialement externe sensiblement plane appliquée sur la surface radialement interne de la paroi 12 et fixée à celle-ci par des vis 52 coopérant avec des écrous sertis du type auto-freinant, et une partie 54 s'étendant radialement vers l'intérieur et qui comprend un orifice traversant aligné avec l'orifice de la patte 26 pour le passage de la vis 32 de fixation de ces pattes. Cette partie 54 comprend une surface radiale 56 d'appui sur la surface radiale 48 de la patte 26 et une surface 58 plane ou sensiblement cylindrique d'appui sur la surface cylindrique 46 de la patte 26. The legs 28 carried by the wall 1 2 each comprise a substantially planar radially outer portion 50 applied to the radially inner surface of the wall 12 and fixed thereto by screws 52 cooperating with crimped nuts of the self-braking type, and a part 54 extending radially inwards and which comprises a through hole aligned with the orifice of the lug 26 for the passage of the screw 32 for fixing these tabs. This portion 54 comprises a radial bearing surface 56 on the radial surface 48 of the lug 26 and a planar or substantially cylindrical bearing surface 58 on the cylindrical surface 46 of the lug 26.
Comme cela est visible en figure 5, la partie 54 de la patte 28 a une dimension circonférentielle inférieure à celle de sa partie 50. Par ailleurs, la partie 50 de la patte 28 est en partie engagée dans un renfoncement 60 de forme complémentaire de la paroi 12.  As can be seen in FIG. 5, the portion 54 of the tab 28 has a circumferential dimension less than that of its portion 50. Moreover, the portion 50 of the tab 28 is partly engaged in a recess 60 of shape complementary to the wall 12.
Les panneaux 18, 20 décrits précédemment peuvent être montés à l'intérieur de la paroi 12 du carter de la façon suivante.  The panels 18, 20 previously described may be mounted within the wall 12 of the housing as follows.
Chaque panneau 18, 20 est disposé en amont de la paroi 12, coaxialement à celui-ci, et est positionnement angulairement autour de l'axe longitudinal du carter de sorte que ses pattes 26, 26' soient alignées axialement avec celles 28, 28' du carter. Le panneau est ensuite déplacé en translation axiale vers l'aval jusqu'à ce qu'il soit logé à l'intérieur de la paroi 12 et que ses pattes 26, 26' soient en appui axial sur celles 28, 28' du carter.  Each panel 18, 20 is disposed upstream of the wall 12, coaxially with it, and is angularly positioned around the longitudinal axis of the housing so that its lugs 26, 26 'are aligned axially with those 28, 28' crankcase. The panel is then moved in axial translation downstream until it is housed inside the wall 12 and that its lugs 26, 26 'are axially supported on those 28, 28' of the housing.
Un outil tel qu'une clef à cliquet équipée d'une rallonge est alors utilisé pour visser les vis 32 dans les pattes afin de solidariser le panneau au carter. Cet outil est inséré axialement depuis l'amont dans l'espace annulaire 40 s'étendant entre le panneau et la paroi.  A tool such as a ratchet equipped with an extension is then used to screw the screws 32 in the tabs to secure the panel to the housing. This tool is inserted axially from upstream in the annular space 40 extending between the panel and the wall.
Comme indiqué précédemment, une telle forme de réalisation nécessite l'utilisation de nombreux moyens de fixation 26, 28, 26', 28', 32, ce qui augmente la masse de l'ensemble. Par ailleurs, la présence des zones denses 62 au niveau des panneaux 18, 20 est également préjudiciable en termes de masse. Enfin, le nombre de panneaux à monter puis à fixer à l'intérieur de la paroi 12 du carter est important, ce qui est long et fastidieux.  As indicated above, such an embodiment requires the use of many fastening means 26, 28, 26 ', 28', 32, which increases the mass of the assembly. Furthermore, the presence of dense areas 62 at the panels 18, 20 is also detrimental in terms of mass. Finally, the number of panels to mount and fix inside the wall 12 of the housing is important, which is long and tedious.
Les figures 6 à 8 illustrent une forme de réalisation n'appartenant pas à l'invention.  Figures 6 to 8 illustrate an embodiment not belonging to the invention.
Cette forme de réalisation diffère de celle décrite précédemment en ce que les panneaux 18, 20 (sectorisés ou monoblocs) sont fixés par un film de colle 66 à la surface interne de la paroi 12. Le film de colle 66 est thermosensible. En effet, il est apte à fixer les panneaux 18, 20 sur ladite paroi 12 lorsque la colle est à une première température et apte à libérer les panneaux 18, 20 de ladite paroi 12 lorsque la colle est chauffée à une seconde température. Un tel film de colle 66 autorise donc le démontage et le montage aisés des panneaux 18, 20. This embodiment differs from that described above in that the panels 18, 20 (sectored or monobloc) are fixed by a adhesive film 66 on the inner surface of the wall 12. The adhesive film 66 is heat-sensitive. Indeed, it is able to fix the panels 18, 20 on said wall 12 when the glue is at a first temperature and able to release the panels 18, 20 of said wall 12 when the glue is heated to a second temperature. Such an adhesive film 66 thus allows easy disassembly and assembly of the panels 18, 20.
Ce film 66 comporte un fil conducteur 68, par exemple à base de carbone, dont les extrémités 70, 72 sont reliées aux bornes d'une alimentation électrique. Le fil 68 est noyé dans la matrice en polymère formée par le film de colle 66. Le passage d'un courant électrique dans le fil 68 provoque son échauffement. Comme cela est représenté à la figure 3, le fil 68 peut être disposé en serpentin et s'étendre sur toute la surface du film 66.  This film 66 comprises a conductive wire 68, for example based on carbon, whose ends 70, 72 are connected to the terminals of a power supply. The wire 68 is embedded in the polymer matrix formed by the adhesive film 66. The passage of an electric current in the wire 68 causes it to overheat. As shown in FIG. 3, the wire 68 can be arranged in a serpentine and extend over the entire surface of the film 66.
En fonctionnement normal, le film de colle 66 est soumis à des températures basses. Dans ce cas, le film 66 assure sa fonction de fixation des panneaux 18, 20 sur la paroi 12.  In normal operation, the adhesive film 66 is subjected to low temperatures. In this case, the film 66 performs its function of fixing the panels 18, 20 on the wall 12.
Ainsi, lorsque l'un des panneaux 18, 20 est endommagé et doit être remplacé, il suffit de chauffer le film 66 de manière à faire ramollir la colle et permettre le retrait du panneau correspondant 18, 20.  Thus, when one of the panels 18, 20 is damaged and must be replaced, it suffices to heat the film 66 so as to soften the adhesive and allow the removal of the corresponding panel 18, 20.
On remplace ensuite ce dernier par un panneau sain. Dans ce cas, le film de colle 66 est à nouveau chauffé pour faciliter l'adhérence du panneau sain sur la paroi 12.  This is replaced by a sound board. In this case, the adhesive film 66 is heated again to facilitate the adhesion of the sound panel to the wall 12.
Une telle forme de réalisation facilite ainsi la réparation d'un carter de soufflante 10, puisqu'elle autorise le démontage aisé et rapide des panneaux 18, 20, en particulier en cas de maintenance sous l'aile d'un avion (c'est-à-dire sans dépose du moteur). Une telle forme de réalisation s'applique également au cas du montage des panneaux 18, 20 en usine.  Such an embodiment thus facilitates the repair of a fan casing 10, since it allows the quick and easy disassembly of the panels 18, 20, in particular in the event of maintenance under the wing of an aircraft (this is ie without removing the engine). Such an embodiment also applies to the case of mounting panels 18, 20 at the factory.
Comme indiqué précédemment, la présence des zones denses 62 au niveau des panneaux 18, 20 est préjudiciable en termes de masse. Enfin, le nombre de panneaux à monter puis à fixer à l'intérieur de la paroi du carter est important, ce qui est relativement fastidieux. Afin de remédier aux inconvénients précités, l'invention propose une turbomachine dans laquelle les deux panneaux annulaires 18, 20 forment un seul et même ensemble structurel. As indicated above, the presence of the dense areas 62 at the panels 18, 20 is detrimental in terms of mass. Finally, the number of panels to mount and fix inside the housing wall is important, which is relatively tedious. In order to overcome the aforementioned drawbacks, the invention proposes a turbomachine in which the two annular panels 18, 20 form one and the same structural assembly.
A cet effet, dans une première forme de réalisation illustrée à la figure 9, l'invention propose de coller le bord aval du panneau 18 au bord amont du panneau 20. Le film de colle correspondant est référencé 74.  For this purpose, in a first embodiment illustrated in FIG. 9, the invention proposes to bond the downstream edge of the panel 18 to the upstream edge of the panel 20. The corresponding glue film is referenced 74.
Comme précédemment, les alvéoles 64 du panneau 18 ont une section plus importante que les alvéoles 64 du second panneau 20.  As before, the cells 64 of the panel 18 have a larger section than the cells 64 of the second panel 20.
Dans cette forme de réalisation, les bords des panneaux 18, 20 destinés à être collés l'un à l'autre ne comportent pas nécessairement de zones denses 62. Seuls le bord amont du panneau 18 et le bord aval du panneau 20 comportent alors une zone dense 62.  In this embodiment, the edges of the panels 18, 20 intended to be glued to each other do not necessarily include dense areas 62. Only the upstream edge of the panel 18 and the downstream edge of the panel 20 then comprise a dense area 62.
Dans cette forme de réalisation également, l'ensemble formé des panneaux 18, 20 comporte des moyens de fixation amont 26, situés au niveau de la partie amont du panneau 18, des moyens de fixation aval 26', situés au niveau de la partie aval du panneau 20, et des moyens de fixation médians 26", situés au niveau de la zone de jonction 74 entre les panneaux 18, 20, lesdits moyens de fixation 26, 26', 26" permettant la fixation desdits panneaux 18, 20 à la paroi 12 du carter. Ces moyens de fixation 26, 26', 26" sont par exemple similaires à ceux décrits en référence aux figures 1 à 5.  In this embodiment also, the assembly formed of the panels 18, 20 comprises upstream fastening means 26, located at the upstream portion of the panel 18, downstream fastening means 26 ', located at the downstream portion of the panel 20, and the median fastening means 26 ", located at the junction zone 74 between the panels 18, 20, said fastening means 26, 26 ', 26" for fixing said panels 18, 20 to the wall 12 of the housing. These fixing means 26, 26 ', 26 "are for example similar to those described with reference to Figures 1 to 5.
La figure 10 illustre une deuxième forme de réalisation de l'invention, dans laquelle un seul panneau 76 assure à la fois la fonction du panneau 18 et la fonction du panneau 20. Ce panneau 76 présente des dimensions semblables à celles de l'ensemble formé par les panneaux 18 et 20 à la figure 9. Il supporte, comme précédemment, une couche de matériau abradable 42 et comporte des zones denses 62 au niveau de ses bords amont et aval. Le panneau 76 présente une structure similaire à celle des panneaux 18, 20, les alvéoles 64 ayant toutefois toutes la même section. Bien entendu, il est possible de faire varier la section des alvéoles en fonction de leur position dans le panneau 76, si les contraintes mécaniques en jeu le requièrent. FIG. 10 illustrates a second embodiment of the invention, in which a single panel 76 provides both the function of the panel 18 and the function of the panel 20. This panel 76 has dimensions similar to those of the formed assembly by panels 18 and 20 in Figure 9. It supports, as before, a layer of abradable material 42 and has dense areas 62 at its edges upstream and downstream. The panel 76 has a structure similar to that of the panels 18, 20, the cells 64 all having the same section. Of course, it is possible to vary the section of the cells depending on their position in the panel 76, if the mechanical stresses involved require it.
Le panneau 76 comporte des moyens de fixation amont 26, situés au niveau de la partie amont du panneau 76, et des moyens de fixation aval 26', situés au niveau de la partie aval du panneau 76.  The panel 76 comprises upstream fixing means 26 situated at the upstream portion of the panel 76, and downstream fixing means 26 'located at the downstream portion of the panel 76.
La figure 1 1 illustre une troisième forme de réalisation similaire à celle de la figure 9, dans laquelle les panneaux 18 et 20 sont fixés à la paroi 1 2 du carter à l'aide d'un film de colle 66 (non représenté sur la figure 1 1 ) similaire à celui décrit en référence aux figures 6 à 8.  FIG. 11 illustrates a third embodiment similar to that of FIG. 9, in which the panels 18 and 20 are fixed to the wall 1 2 of the casing with the aid of a glue film 66 (not shown in FIG. Figure 1 1) similar to that described with reference to Figures 6 to 8.
De même, la figure 12 illustre une troisième forme de réalisation similaire à celle de la figure 10, dans laquelle le panneau 76 est fixé sur la paroi 1 2 du carter à l'aide d'un film de colle 66 (non représenté sur la figure 12) similaire à celui décrit en référence aux figures 6 à 8.  Likewise, FIG. 12 illustrates a third embodiment similar to that of FIG. 10, in which the panel 76 is fixed on the wall 1 2 of the casing with the aid of an adhesive film 66 (not shown in FIG. Figure 12) similar to that described with reference to Figures 6 to 8.
Dans chacune de ces formes de réalisation, la masse de l'ensemble est réduite par comparaison à l'art antérieur, que ce soit par le nombre réduit de zones denses 62 ou par le nombre réduit de moyens de fixation. Par ailleurs, le fait de disposer d'un ensemble structurel unique, assurant les mêmes fonctions que les panneaux 18 et 20 de l'art antérieur, permet de faciliter son montage et son démontage.  In each of these embodiments, the mass of the assembly is reduced by comparison with the prior art, either by the reduced number of dense areas 62 or by the reduced number of fixing means. Furthermore, the fact of having a single structural assembly, providing the same functions as the panels 18 and 20 of the prior art, facilitates its assembly and disassembly.

Claims

REVENDICATIONS
1 . Turbomachine, telle qu'un turboréacteur ou un turbopropulseur d'avion, comprenant un carter (10) de soufflante comportant une paroi (12) sensiblement cylindrique entourant les aubes de la soufflante, et au moins deux panneaux annulaires (18, 20) d'isolation acoustique montés radialement à l'intérieur de ladite paroi (12), un premier panneau (18) étant monté en amont de la soufflante, un second panneau (20) étant situé en aval du premier panneau (18) et portant une couche interne (42) en matériau abradable située en regard des extrémités radialement externes des aubes de la soufflante, caractérisée en ce que le bord aval du premier panneau (18) est fixé au bord amont du second panneau (20), par exemple par collage (74). 1. A turbomachine, such as an airplane turbojet or turboprop, comprising a fan casing (10) having a substantially cylindrical wall (12) surrounding the blades of the blower, and at least two annular panels (18, 20) of acoustic insulation mounted radially inside said wall (12), a first panel (18) being mounted upstream of the blower, a second panel (20) being located downstream of the first panel (18) and carrying an inner layer (42) of abradable material located opposite the radially outer ends of the blades of the fan, characterized in that the downstream edge of the first panel (18) is fixed to the upstream edge of the second panel (20), for example by gluing (74). ).
2. Turbomachine selon la revendication 1 , caractérisé en ce que chaque panneau (18, 20) comporte une structure annulaire en nid d'abeille 2. Turbomachine according to claim 1, characterized in that each panel (18, 20) comprises an annular structure honeycomb
(34) formée d'alvéoles (64) adjacentes, les surfaces interne et externe de ladite structure annulaire (34) étant recouvertes respectivement d'une peau interne (36) et d'une peau externe (38). (34) formed of adjacent cells (64), the inner and outer surfaces of said annular structure (34) being covered respectively with an inner skin (36) and an outer skin (38).
3. Turbomachine selon la revendication 2, caractérisée en ce que les alvéoles (64) du premier panneau (18) ont une section plus importante que les alvéoles (64) du second panneau (20).  3. Turbomachine according to claim 2, characterized in that the cells (64) of the first panel (18) have a larger section than the cells (64) of the second panel (20).
4. Turbomachine selon la revendication 2 ou 3, caractérisée en ce qu'au moins une partie de la peau interne (36) du premier panneau (18) et/ou du second panneau (20) comporte des perforations.  4. Turbomachine according to claim 2 or 3, characterized in that at least a portion of the inner skin (36) of the first panel (18) and / or the second panel (20) has perforations.
5. Turbomachine selon l'une des revendications 1 à 4, caractérisée en ce qu'elle comporte des moyens de fixation amont (26), situés au niveau de la partie amont du premier panneau (18), des moyens de fixation aval (26'), situés au niveau de la partie aval du second panneau (20), et des moyens de fixation médians (26"), situés au niveau de la zone de jonction (74) entre les premier et second panneaux (18, 20), lesdits moyens de fixation (26, 26', 26") permettant la fixation desdits panneaux (18, 20) à la paroi (12) du carter. 5. Turbomachine according to one of claims 1 to 4, characterized in that it comprises upstream fixing means (26), located at the upstream portion of the first panel (18), downstream fixing means (26). '), located at the downstream portion of the second panel (20), and middle fastening means (26 "), located at the junction area (74) between the first and second panels (18, 20) , said fastening means (26, 26 ', 26 ") for attaching said panels (18, 20) to the housing wall (12).
6. Turbomachine selon l'une des revendications 1 à 5, caractérisée en ce que les panneaux (18, 20, 76) sont fixés à la paroi du carter par l'intermédiaire d'un film de colle (66).  6. Turbomachine according to one of claims 1 to 5, characterized in that the panels (18, 20, 76) are fixed to the housing wall by means of an adhesive film (66).
7. Turbomachine selon la revendication 6, caractérisée en ce que la colle est une colle thermosensible apte à fixer le panneau (18, 20, 76) sur ladite paroi (12) lorsque la colle est à une première température et apte à libérer le panneau (18, 20, 76) lorsque la colle est chauffée à une seconde température.  7. A turbomachine according to claim 6, characterized in that the adhesive is a heat-sensitive adhesive capable of fixing the panel (18, 20, 76) on said wall (12) when the adhesive is at a first temperature and able to release the panel (18, 20, 76) when the glue is heated to a second temperature.
EP14715361.3A 2013-03-15 2014-03-12 Turbine engine, such as an airplane turbofan or turboprop engine Withdrawn EP2971738A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1352353A FR3003303B1 (en) 2013-03-15 2013-03-15 TURBOMACHINE, SUCH AS A TURBOJET OR AIRCRAFT TURBOPROPULSER
PCT/FR2014/050566 WO2014140483A1 (en) 2013-03-15 2014-03-12 Turbine engine, such as an airplane turbofan or turboprop engine

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EP2971738A1 true EP2971738A1 (en) 2016-01-20

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EP14715361.3A Withdrawn EP2971738A1 (en) 2013-03-15 2014-03-12 Turbine engine, such as an airplane turbofan or turboprop engine

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US (1) US20160032834A1 (en)
EP (1) EP2971738A1 (en)
JP (1) JP2016513773A (en)
CN (2) CN106979040A (en)
BR (1) BR112015023057A8 (en)
CA (1) CA2905793A1 (en)
FR (1) FR3003303B1 (en)
RU (1) RU2015138543A (en)
WO (1) WO2014140483A1 (en)

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JP2016513773A (en) 2016-05-16
RU2015138543A (en) 2017-04-19
US20160032834A1 (en) 2016-02-04
FR3003303A1 (en) 2014-09-19
CN105051360A (en) 2015-11-11
BR112015023057A8 (en) 2019-12-03
FR3003303B1 (en) 2017-06-30
WO2014140483A1 (en) 2014-09-18
CN106979040A (en) 2017-07-25
BR112015023057A2 (en) 2017-07-18
CA2905793A1 (en) 2014-09-18

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