Abstract:
The invention relates to an air intake structure that can be mounted upstream of a nacelle middle structure for an aircraft engine, and that particularly includes: an outer wall ( 7 ) including a lip ( 9 ) and that can be mounted relative to said middle structure so as to move between a rear position and a front position; a wall ( 11 ) defining a de-icing compartment ( 13 ) in said lip ( 9 ); at least one de-icing collector ( 15 ) extending in said compartment ( 13 ); and at least one hot-air supply duct ( 17 ) of said collector ( 15 ), that can be rigidly connected to said middle structure. The wall ( 11 ) is tightly secured inside said lip ( 9 ), and said supply duct ( 17 ) is connected to said collector ( 15 ) by removable sealing means ( 27, 29, 31, 35 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an air intake structure designed to be mounted upstream of a mid-structure of a nacelle for an aircraft engine, and to a nacelle equipped with such an air intake structure. 
       BACKGROUND 
       [0002]    In its patent application FRO6/08599, filed on 2 Oct. 2006, the applicant described (see  FIGS. 1 to 3  appended) a nacelle  1  for an aircraft engine comprising an air intake structure  3  designed to be mounted upstream of a mid-structure  5 , said air intake structure  3  comprising in particular:
       an external wall  7  incorporating a lip  9  and designed to be mounted movably with respect to said mid-structure  5  between a rear position ( FIG. 2 ) and a front position ( FIG. 3 ),   a partition  11  defining a deicing compartment  13  in said lip  9 ,   at least one deicing manifold  15  extending in said compartment  13 , and   at least one duct  17  for supplying hot air to said manifold  15 , which duct is designed to be connected in a fixed manner to said mid-structure  5 .       
 
         [0007]    In order to seal the deicing compartment  13  when the external wall  7  is in the rear position ( FIG. 2 ), that is to say in the normal operating position, it is necessary to provide seals  19   a ,  19   b  secured to the upper and lower parts of the partition  11 . 
         [0008]    In practice, the sealing obtained with these seals is not completely satisfactory: the successive opening and closing of the external wall  7 , required for maintenance operations, have the effect of modifying the positioning and the shape of this seal, with the result that in time leaks of deicing hot air have a tendency to appear between the compartment  13  and the region  21  of the air intake structure  1  situated downstream of the partition  11 . 
         [0009]    The intake of deicing hot air in this region  21  is not desirable since it risks damaging certain equipment, in particular electrical and electronic equipment, situated in this region. 
         [0010]    Document FR2757823 discloses the principle of a pipe for supplying hot air to a deicing compartment, comprising a part mounted on the fixed mid-structure of the nacelle and a part mounted on the movable air intake structure, these two pipe parts being connected in a disconnectable manner to one another. 
         [0011]    Although it makes it possible to overcome the aforementioned sealing problem, this device of the prior art has the disadvantage of substantially increasing the weight of the movable part of the air intake structure. 
       BRIEF SUMMARY 
       [0012]    The aim of the present invention is to overcome all of the aforementioned disadvantages. 
         [0013]    The invention provides an air intake structure designed to be mounted upstream of a mid-structure of a nacelle for an aircraft engine, said air intake structure comprising in particular:
       an external wall incorporating a lip and designed to be mounted movably with respect to said mid-structure between a rear position and a front position,   a partition defining a deicing compartment in said lip,   at least one deicing manifold extending in said compartment,   at least one duct for supplying hot air to said manifold, which duct is designed to be connected in a fixed manner to said mid-structure,
 
in which structure said partition is fixed in a sealed manner inside said lip, and said supply duct is connected to said manifold by disconnectable sealed means,
 
this structure being noteworthy in that said disconnectable sealed means are situated in the immediate vicinity of said partition.
       
 
         [0018]    Thus, the partition provides perfect sealing of the deicing compartment, the disconnectable sealed means provide sealed fluid communication between the hot air supply duct and the manifold, and given the immediate proximity of these disconnectable sealed means with the partition, the length of the hot air manifold is reduced to a minimum, with the result that the excess weight brought by this manifold to the movable part (external wall+deicing manifold+partition) of the air intake structure is also minimal. 
         [0019]    It should also be noted that, consequently, the cost of replacing this movable part of the air intake structure is for its part also minimal.
       the internal face of said air intake structure is designed to be mounted in a fixed manner on said mid-structure: this particular embodiment corresponds to that described in the patent application mentioned above, in which this internal face is in fact a cylindrical wall provided with a noise absorption structure;   said external wall is designed to be mounted in a sliding manner on said mid-structure: this particular embodiment also corresponds to one of those described in said patent application, and permits an easy movement of the internal structure between its rear (normal operation) and front (maintenance) positions;   said disconnectable sealed means comprise a manifold end and a supply duct end which are male and female, or vice versa, and sealing means such as at least one seal mounted on or inside these ends: these male and female ends allow a rapid connection/disconnection between the supply duct and the deicing manifold, without adjustment of diameter and length dimensions. This therefore allows a good tolerance to the manufacturing deviations of the various components involved;   said female end has a funnel shape: this particular shape allows the male end to be guided in the female end during the connection;   said manifold end passes through said partition in a sealed manner: this particular embodiment is of a particularly simple design;   said partition defines a housing around said manifold end, sealing means such as seals being interposed on the one hand between this manifold end and the end of said supply duct, and on the other hand between said partition and this end of the supply duct: in the case of a leakage of the sealing means interposed between the manifold end and the end of the supply duct, the hot air remains confined in the housing and therefore does not spread downstream of the partition;   said partition defines an orifice traversed in a nonsealed manner by said manifold end, sealing means such as seals being interposed, on the one hand between this manifold end and the end of said supply duct, and on the other hand between the edges of said orifice and this supply duct end: in the case of a leakage of the sealing means interposed between the manifold end and the end of the supply duct, the hot air remains confined in the deicing compartment, and therefore does not spread downstream of the partition;   said supply duct comprises a double wall: such a double wall makes it possible to prevent the hot air circulating in the duct from escaping into the region situated downstream of the partition in the event of the internal wall of this duct bursting;   said supply duct comprises at its end at least one orifice for communication between said housing and the space situated between the two duct walls: this orifice makes it possible to avoid the pressurization of this housing in the event of leakage through the sealing means situated between the end of the manifold and the end of the supply duct, and therefore to avoid the risk of leakage through the sealing means situated between this housing and this supply duct end;   this air intake structure comprises an air leak detector arranged in the space situated between the two walls of the supply duct: this detector makes it possible to signal any hot air escape at the sealing means situated between the end of the manifold and the end of the supply duct.       
 
         [0030]    The present invention also relates to a nacelle for an aircraft engine, which is noteworthy in that it comprises an air intake structure according to the foregoing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    Other features and advantages of the present invention will become apparent in light of the description which follows and from an examination of the appended figures, in which: 
           [0032]      FIG. 1  represents in perspective a nacelle of the prior art, described in the preamble of the present description, suspended below an airplane wing  23  by means of a pylori  24 , 
           [0033]      FIGS. 2 and 3  represent views in axial section, that is to say taken on the plane P in  FIG. 1 , of the upper part of the air intake structure of this nacelle of the prior art, in respective normal operating and maintenance positions, 
           [0034]      FIGS. 4 and 5  are views analogous to  FIGS. 2 and 3  of a first embodiment of an air intake structure according to the invention, 
           [0035]      FIG. 6  is a partial view of a supply duct of this air intake structure, 
           [0036]      FIGS. 7 and 8  are views analogous to  FIGS. 2 and 3  of a second embodiment of an air structure according to the invention, 
           [0037]      FIG. 9  is a view analogous to that in  FIG. 7  of a variant of this second embodiment, 
           [0038]      FIGS. 10 and 11  are analogous views respectively to  FIGS. 2 and 3  of a third embodiment of an air structure according to the invention, 
           [0039]      FIGS. 12 and 13  are analogous views respectively to  FIGS. 2 and 3  of a fourth embodiment of an air intake structure according to the invention, and 
           [0040]      FIG. 14  is an axial view of the manner of fastening a deicing manifold end to a partition of the air intake structure represented in  FIGS. 12 and 13 . 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    In all the figures of the present patent application, identical references designate members or a set of members which are identical or analogous. 
         [0042]    As can be seen in  FIG. 4 , the air intake structure according to the invention comprises an external wall  7  incorporating a lip  9 . 
         [0043]    The lip  9  is the part of the air intake structure situated furthest upstream, that is to say the part of this air intake structure which as it were constitutes the leading edge thereof. 
         [0044]    As indicated in the subject of  FIGS. 2 and 3 , the assembly formed by the external wall  7  and its lip  9  is mounted slidably between a rear position represented in  FIG. 4  and a front position represented in  FIG. 5 , with respect to a fixed mid-structure  5  of the nacelle (not visible in  FIGS. 4 and 5 ). 
         [0045]    The normal operating configuration is that shown in  FIG. 4 , the configuration of  FIG. 5  being a maintenance configuration allowing access in particular to the fixed mid-structure  5  of the nacelle. 
         [0046]    The air intake structure according to the invention also comprises an internal wall  25 , mounted in a fixed manner on the mid-structure  5 . 
         [0047]    Conventionally, the fixed internal wall  25  comprises an acoustic treatment, that is to say that it can be covered by a honeycomb structure designed to reduce sound emissions. 
         [0048]    Inside the lip  9  is situated a deicing manifold  15  designed to circle, inside this lip, hot air coming from a supply duct  17  itself connected to a hot air source mounted fixedly with respect to the mid-structure  5 . 
         [0049]    A partition  11  delimits the deicing compartment  13 , inside which the manifold  15  extends. 
         [0050]    This partition is fastened in a sealed manner, for example by riveting, inside the lip  9 . 
         [0051]    In the embodiment represented in  FIGS. 4 and 5 , the manifold  15  comprises at least one end  27  passing through the partition  11  in a sealed manner, this end  27  being able, for example, to be welded at its periphery to the partition  11 . 
         [0052]    This end  27  comprises sealing means  29  and is able to enter inside a funnel-shaped female part  31  forming the end of the hot air supply duct  17 . 
         [0053]    The expression “sealing means” used in the context of the present invention denotes any sealing system designed to withstand the high temperatures of the hot air circulating in the duct  17  (typically of around 500° C.) and tolerating the sliding movement. 
         [0054]    These sealing means can in particular be formed by seals of suitable materials. 
         [0055]    In the normal operating position, represented in  FIG. 4 , the end  27  of the manifold  15  is therefore situated inside the end  31  of the duct  17 , and forms a sealed connection therewith. 
         [0056]    In the maintenance position, represented in  FIG. 5 , the external wall  7  incorporating the lip  9 , and hence the partition  11  and the manifold  15 , are moved toward the front of the nacelle, that is to say in this case toward the left in the figure. 
         [0057]    In so doing, the male end  27  of the manifold  15  is disengaged from the female end  31  of the duct  17 . 
         [0058]    It may be noted that the duct  17  preferably comprises an internal wall  17   a  and an external wall  17   b  so as to limit the risks of hot air escaping inside the cavity  21  in the event of the wall  17   a  bursting. 
         [0059]    According to a variant visible in  FIG. 6 , it can be seen that the funnel shape of the end  31  of the duct  17  can be formed on the external wall  17   b  of the duct  17 , thus allowing a saving in the duct diameter and also a weight saving. 
         [0060]    In the embodiment in  FIGS. 7 and 8 , the partition  11  defines a housing  33  around the end  31  of the duct  17 , second sealing means  35  sealing this housing with respect to the cavity  21  when the air intake structure is in the normal operating configuration. 
         [0061]    This particular arrangement makes it possible to contain within the housing  33  any leakage of hot air due to poor sealing of the sealing means  29 . 
         [0062]    In the variant represented in  FIG. 9 , it can be seen that a communication orifice  37  can be provided between the housing  33  and the space  39  situated between the two walls  17   a  and  17   b  of the supply duct. 
         [0063]    This orifice  37  makes it possible to avoid the pressurization of the housing  33  in the event of leakage through the sealing means  29 ; this makes it possible to limit the risk of leakage of this air through the second sealing means  35  in the direction of the cavity  21 . 
         [0064]    Advantageously, a leak detector  41  housed in a space  39  can be provided, this air leak detector being itself connected by a suitable electrical connection to a control system. 
         [0065]    The embodiment represented in  FIGS. 10 and 11  differs from the preceding ones in that it is the end  27  of the manifold  15  which has a funnel shape, the end  31  of the duct  17  for its part having a straight shape: in this embodiment, the end  27  of the manifold  15  and the end  31  of the duct  17  respectively constitute the female and male parts of this disconnectable sealed connection. 
         [0066]    The sealing means  29  which provide sealing for this connection are in this case preferably arranged around the end  31  of the duct  17 . 
         [0067]    In the variant represented in  FIGS. 12 and 13 , the end  27  of the manifold  5  is no longer connected to the partition  11 , but passes in a nonsealed manner through an orifice  45  formed in this partition  11 . 
         [0068]    The end  27  of the manifold  15  can be connected to the partition  11  by fittings  47  or by adjustable tie rods arranged at 120°, as is represented in  FIG. 14 . 
         [0069]    First sealing means  29  are interposed between the male end  27  of the manifold  15  and the female end  31  of the duct  17 , and second sealing means  35  are interposed between this female end  31  and a return  47  formed in the partition  11 . 
         [0070]    In the case of a hot air leak through the first sealing means  29 , this air emerges directly into the deicing compartment  13 , thereby reducing the risk of leakage in the direction of the cavity  21 . 
         [0071]    It will be noted that, preferably, as has been represented for all of the embodiments described above, the region of connection between the end  27  of the manifold  15  and the end  31  of the duct  17  is preferably situated in the immediate vicinity, or even in the plane, of the partition  11 : this makes it possible to limit the overall weight of the movable parts, that is to say of the parts capable of moving with the external wall  7  during its movement between its normal operating position and its maintenance position. 
         [0072]    This weight limitation makes it possible to lighten the means (guide rails, actuating mechanism, etc.) which make it possible to move this external wall between said two positions. 
         [0073]    What is more, in the case of damage to the aforementioned movable parts, their replacement is less costly since the elements constituting these movable parts are designed to be just adequate. 
         [0074]    It will also be noted that the disconnectable connection between the end  27  of the manifold  15  and the end  31  of the duct  17  allows an easy inspection of the manifold  15  on the one hand and of the duct  17  on the other hand when the external panel  7  is in the maintenance position. 
         [0075]    It will further be noted that the disconnectable nature of the connection between the male and female (or vice versa) ends of the manifold  15  and of the duct  17  makes it possible to dispense with an adjustment of diameter and length dimensions: that thus allows a good tolerance to the manufacturing deviations of the various components involved. 
         [0076]    Of course, the present invention is in no way limited to the embodiments described and represented, which are provided purely by way of example.