Patent Publication Number: US-2023133758-A1

Title: Aircraft drainage valve, tool for checking the correct operation of said drainage valve and method for checking the operation of said drainage valve using said checking tool

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of the French patent application No. 2111533 filed on Oct. 29, 2021, the entire disclosures of which are incorporated herein by way of reference. 
     FIELD OF THE INVENTION 
     The present application relates to an aircraft drainage valve, to a tool for checking the correct operation of the drainage valve and to a method for checking the operation of the drainage valve using the checking tool. 
     BACKGROUND OF THE INVENTION 
     According to an embodiment visible in  FIG.  1   , the cell  10  of an aircraft comprises, among other things, a fuselage  12 , an airfoil  14  and a tail unit  16 . The cell  10  of an aircraft comprises at least one drainage valve  18 , illustrated in detail in  FIGS.  2  and  3   , positioned at a low point of the cell  10  to discharge fluids out of the cell  10 . 
     The cell  10  has an internal pressure substantially equal to the external pressure, when the aircraft is on the ground. When the aircraft is in flight, the internal pressure of the cell  10  is greater than the external pressure and the differential between the internal and external pressures increases as a function of the altitude of the aircraft. 
     The drainage valve  18  is configured to occupy an open state, visible in  FIG.  2   , allowing the discharging of the fluids, more particularly the discharging of the liquids  20  by gravity, when the aircraft is on the ground or the differential between the internal and external pressures is below a given threshold, and a closed state, as illustrated in  FIG.  3   , preventing the flow of the fluids out of the aircraft when the latter is in flight and the differential between the internal and external pressures is above or equal to the given threshold. 
     According to one embodiment, the drainage valve  18  is positioned in line with an orifice  22 . 1  of a wall  22  of the cell  10  allowing the inside and the outside of the cell  10  to be connected. This drainage valve  18  comprises: 
     a support  24  configured to be fixed against the inner face of the wall  22  of the cell  10 , all around the orifice  22 . 1 , 
     a ring  26  positioned at the orifice  22 . 1  having a through hole  28 , 
     a shutter  30  that is movable between a first position, corresponding to the open state, in which it is away from the ring  26  and allows the flow of the fluids via the through hole  28  and a second position, corresponding to the closed state, in which it is pressed against the ring  26  and blocks the through hole  28 , 
     a spring  32  configured to keep the shutter  30  in the first position as long as the differential between the internal and external pressures is below the given threshold. 
     Thus, as illustrated in  FIG.  2   , when the differential between the internal and external pressures is below the given threshold, the aircraft being on the ground for example, the spring  32  keeps the shutter  30  away from the ring  26 , notably allowing the liquids  20  to flow by gravity via the through hole  28  out of the cell  10 . 
     As illustrated in  FIG.  3   , in flight, from a certain altitude, the differential between the internal and external pressures becomes greater than or equal to the given threshold. Consequently, the pressure inside the cell  10  is sufficient to push the shutter  30 , working against the spring  32 , against the ring  26  in order to block the through hole  28  and prohibit any flow of fluids out of the cell  10  via the through hole  28 . 
     The correct operation of this drainage valve  18  is regularly checked. As illustrated in  FIG.  4   , when the shutter  30  is blocked in the second position, corresponding to the closed state, while the differential between the internal and external pressures is below the given threshold, it is possible to unblock the shutter  30 , by pushing it with a rod  34  introduced via the through hole  28 . 
     On the other hand, if the shutter  30  is blocked in the first position, for example because of being parked for a long time on the ground, it is difficult to check that it is operating correctly or to unblock it, access to the drainage valve  18  being difficult, even impossible, from the inside of the cell  10 . 
     The present invention aims to remedy all or part of the drawbacks of the prior art. 
     SUMMARY OF THE INVENTION 
     To this end, a subject of the invention is a drainage valve comprising: 
     a support configured to be fixed against an inner face of a wall in line with an orifice passing through the wall, 
     a ring having a through hole and a seat around the through hole, configured to be positioned at the orifice, 
     a shutter comprising an end face delimited by a peripheral edge, the shutter being movable in a longitudinal direction between a first position in which the end face of the shutter is away from the seat of the ring and a second position in which the end face of the shutter is pressed against the seat of the ring and blocks the through hole, 
     an elastic element configured to keep the shutter in the first position as long as a differential between pressures on either side of the wall is below a given threshold. 
     According to the invention, the shutter has a cylindrical body and a recess emerging at its end face, the recess being spaced apart from the peripheral edge over the entire circumference of the peripheral edge, the recess comprising a lateral wall that is cylindrical and substantially coaxial to the cylindrical body of the shutter. 
     Thus, it is possible to introduce into the recess of the shutter a part of a tool and to temporarily secure the part of the tool and the shutter in order to displace it in two opposite directions longitudinally. 
     According to another feature, the recess comprises a counterbore, away from the end face, which has a diameter greater than that of the lateral wall of the recess. 
     Also, a subject of the invention is a tool for checking the operation of a drainage valve according to one of the preceding features. This checking tool comprises a stem which extends between first and second ends, at least one expandable element positioned at the first end of the stem and configured to occupy a retracted state in which the expandable element can be inserted into the recess, and a deployed state in which the expandable element cooperates with the recess and makes it possible to temporarily link the stem and the shutter to displace it in two opposite directions longitudinally, and a control configured to switch the expandable element from the retracted state to the deployed state or vice versa. 
     According to another feature, the stem has a longitudinal axis linking its first and second ends. In addition, the expandable element comprises at least two arms each having a first end linked to the stem by an articulation and a free second end, each articulation comprising a pivoting axis at right angles to the longitudinal axis and spaced apart therefrom, the pivoting axes of the arms being distributed about the longitudinal axis such that the arms pivot in planes passing through the longitudinal axis and evenly distributed about the latter. 
     According to another feature, each arm comprises, at its free second end, a block configured to cooperate with a counterbore of the recess of the shutter. 
     According to another feature, the control is positioned at the second end of the stem. 
     According to another feature, the stem is hollow. In addition, the control comprises a rod sliding in the stem and having a first end linked to the arms and a grippable second end protruding from the second end of the stem. 
     According to another feature, the second end of the rod comprises a head. 
     Also, a subject of the invention is a method for checking the operation of a drainage valve by using a checking tool according to one of the preceding features. This checking method comprises a step of insertion of the expandable element of the checking tool in the retracted state into the recess of the shutter, a step of activation of the control to switch the expandable element to the deployed state, a step of verification of the operation and/or of unblocking of the drainage valve by displacing the checking tool parallel to the longitudinal direction in two opposite directions, a step of deactivation of the control to switch the expandable element from the deployed state to the retracted state and then a step of removal of the expandable element from the recess. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages will emerge from the following description of the invention, a description given purely by way of example, in light of the attached drawings in which: 
         FIG.  1    is a side view of an aircraft, 
         FIG.  2    is a longitudinal cross section of a drainage valve illustrating an embodiment of the prior art in the open state, 
         FIG.  3    is a longitudinal cross section of the drainage valve visible in  FIG.  2    in the closed state, 
         FIG.  4    is a longitudinal cross section of the drainage valve visible in  FIG.  2   , its shutter being blocked in a position corresponding to the closed state, 
         FIG.  5    is a longitudinal cross section of a drainage valve illustrating an embodiment of the invention in the open state, 
         FIGS.  6 A and  6 B  are a side view of a tool for checking the correct operation of the drainage valve visible in  FIG.  5   ,  FIG.  6 A  showing the tool in the retracted state and  FIG.  6 B  showing it in the deployed state, 
         FIG.  7    is a schematic representation of the checking tool in the retracted state upon its insertion into the drainage valve, and 
         FIG.  8    is a schematic representation of the checking tool in the deployed state when checking the correct operation of the drainage valve. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In  FIGS.  5 ,  7  and  8   , a drainage valve  40  is represented positioned at an orifice  42  passing through a wall  44 . 
     According to one application, the wall  44  is a wall of a cell of an aircraft, like the fuselage of an aircraft for example, and the orifice  42  is positioned at a low point of the cell of the aircraft. 
     The wall  44  has an inner face  44 . 1  oriented toward an internal zone Zi and an outer face  44 . 2  (opposite the inner face  44 . 1 ) oriented toward an external zone Ze. In operation, the internal zone Zi has an internal pressure and the external zone Ze an external pressure. When the aircraft is on the ground, the internal and external pressures are substantially equal. In flight, the internal and external pressures have a non-zero differential which varies notably as a function of the altitude. 
     In operation, at least one liquid  46  can accumulate, in the internal zone Zi, against the inner face  44 . 1  of the wall  44 , at the low point. This liquid  46  must be discharged to the external zone Ze. 
     Hereinafter in the description, a liquid will be understood to mean a liquid or a mixture of several liquids. 
     A longitudinal direction corresponds to a direction at right angles to the wall  44  passing through the center of the orifice  42 . A longitudinal plane is a plane containing the longitudinal direction. 
     The drainage valve  40  is configured to occupy an open state, visible in  FIG.  5   , allowing the discharging of the fluids, more particularly the discharging of the liquid  46  by gravity, from the internal zone Zi to the external zone Ze when the differential between the internal and external pressures is below a given threshold, and a closed state preventing the flow of the fluids to the external zone Ze when the differential between the internal and external pressures is above or equal to the given threshold. 
     According to one embodiment, the drainage valve  40  comprises: 
     a support  48  configured to be fixed against the inner face  44 . 1  of the wall  44 , all around the orifice  42 , 
     a ring  50  positioned at the orifice  42  having a through hole  52 , 
     a shutter  54  that is mobile longitudinally between a first position, corresponding to the open state, in which the shutter  54  is away from the ring  50  and allows a flow of the liquid  46  via the through hole  52  and a second position, corresponding to the closed state, in which the shutter  54  is pressed against the ring  50  and blocks the through hole  52 , 
     an elastic element  56 , like a spring for example, configured to keep the shutter  54  in the first position as long as the differential between the internal and external pressures is below the given threshold. 
     The support  48  comprises a tubular wall  58  which extends between first and second ends  58 . 1 ,  58 . 2 , a transverse wall  60  positioned at the second end  58 . 2 , and a flange ring  62  positioned at the first end  58 . 1  of the tubular wall  58 , all around the tubular wall  58 . The tubular and transverse walls  58 ,  60  and the flange ring  62  form one and the same part. 
     In operation, the flange ring  62  is pressed against the inner face  44 . 1  of the wall  44  and secured to the latter by link elements  64 . 
     When the support  48  is linked to the wall  44 , the tubular and transverse walls  58 ,  60  delimit a cavity  66 . The tubular wall  58  has at least one lateral orifice  68  configured to connect to the internal zone Zi and the cavity  66 . According to one configuration, the tubular wall  58  is cylindrical and has several lateral orifices  68  distributed over its circumference and juxtaposed with the flange ring  62 . 
     The transverse wall  60  has a through hole  60 . 1 , substantially coaxial to the tubular wall  58 . 
     The support  48  also comprises a cylindrical recess  70  that is closed at a first end by a first end wall  70 . 1  positioned outside of the cavity  66  and at a second end by a second end wall  70 . 2  positioned in the cavity  66 . The cylindrical recess  70  has an external diameter substantially equal to the diameter of the through hole  60 . 1  of the transverse wall  60 . According to a first configuration, the cylindrical recess  70  is fixed with respect to the transverse wall  60 . According to this first configuration, the cylindrical recess  70  and the transverse wall  60  could form only one and the same part. 
     According to a second configuration, the cylindrical recess  70  is movable with respect to the transverse wall  60  and linked to the latter by a screw pitch, as illustrated in  FIG.  5   . According to this second configuration, the cylindrical recess  70  can be translated longitudinally with respect to the transverse wall  60  by screwing it in more or less. This configuration makes it possible to correctly position the ring  50  with respect to the outer face  44 . 2  of the wall  44 . 
     The ring  50  has a first face  50 . 1  oriented toward the external zone Ze, a second face  50 . 2  oriented toward the cavity  66  and parallel to the first face  50 . 1 , and a peripheral face  50 . 3  linking the first and second faces  50 . 1 ,  50 . 2  having a diameter fitted to that of the orifice  42  passing through the wall  44 . In operation, the first face  50 . 1  is flush with the outer face  44 . 2  of the wall  44 . 
     The through hole  52  links the first and second faces  50 . 1 ,  50 . 2  and is substantially coaxial to the peripheral face  50 . 3 . According to one configuration, the ring  50  comprises a countersink  50 . 4  on the second face  50 . 2 , coaxial to the through hole  52 . Whatever the embodiment, the ring  50  comprises a seat around the through hole  52  formed by the second face  50 . 2  and/or the countersink  50 . 4 . 
     The ring  50  is linked to the cylindrical recess  70  in such a way that the through hole  52  is substantially coaxial to the cylindrical recess  70 , the second face  50 . 2  of the ring  50  and the second end wall  70 . 2  of the cylindrical recess  70  being spaced apart from one another so as to allow a liquid  46  to flow by gravity from the cavity  66  to the through hole  52 . 
     The shutter  54  comprises a cylindrical body  72  which extends between a first end oriented toward the ring  50  and a second end, and a head  74  in the form of a disk, secured to the second end of the cylindrical body  72  and substantially coaxial to the cylindrical body  72 . The head  74  of the shutter  54  has a diameter substantially equal to or very slightly less than the internal diameter of the cylindrical recess  70 . Thus, the shutter  54  forms a piston sliding in the cylindrical recess  70 . The first end of the cylindrical body  72  forms an end face  76  that is flat and at right angles to the axis of the cylindrical body  72 . The end face  76  is delimited by a peripheral edge  76 . 1  having a diameter D 76 . 1  greater than the diameter of the through hole  52 . 
     The first end wall  70 . 1 , oriented toward the internal zone Zi, comprises at least one orifice  78  allowing the internal zone Zi and a zone of the cylindrical recess  70  situated between the head  74  of the shutter  54  and the first end wall  70 . 1  to be connected. The second end wall  70 . 2 , oriented toward the ring  50 , comprises a through orifice  80  having a diameter slightly greater than that of the cylindrical body  72  of the shutter  54 . 
     In operation, the cylindrical body  72  passes through the through orifice  80  of the second end wall  70 . 2 . When the shutter  54  occupies the first position, the end face  76  of the cylindrical body  72  of the shutter  54  is away from the seat formed by the second face  50 . 2  and/or the countersink  50 . 4  of the ring  50 . When the shutter  54  occupies the second position, the end face  76  of the cylindrical body  72  of the shutter  54  is in contact with the seat formed by the second face  50 . 2  and/or the countersink  50 . 4  of the ring  50  and blocks the through hole  52 . 
     According to one embodiment, the elastic element  56  is a compression spring inserted on the one hand between the cylindrical body  72  of the shutter  54  and the cylindrical recess  70 , and, on the other hand, between the head  74  of the shutter  54  and the second end wall  70 . 2  of the cylindrical recess  70 . 
     Obviously, the invention is not limited to this embodiment for the support  48 , the ring  50 , the shutter  54  and the elastic element  56 . 
     According to a feature of the invention, the shutter  54  has a recess  82  emerging at the end face  76  of the cylindrical body  72 . This recess  82  is spaced apart from the peripheral edge  76 . 1  over the entire circumference of the peripheral edge  76 . 1  in such a way that the end face  76  is in contact with the seat formed by the second face  50 . 2  and/or the countersink  50 . 4  of the ring  50 , all around the through hole  52 , when the shutter  54  occupies the second position corresponding to the closed state of the drainage valve. 
     According to one configuration, the recess  82  comprises a lateral wall  82 . 1  that is cylindrical and substantially coaxial to the cylindrical body  72  of the shutter  54 . 
     According to one embodiment, the recess  82  comprises a counterbore  84 , away from the end face  76 , which has a diameter greater than that of the lateral wall  82 . 1  of the recess  82 . The recess  82  generally has a flat bottom  82 . 2 . 
     The invention also proposes a checking tool  85  comprising a stem  86  which extends between first and second ends  86 . 1 ,  86 . 2 , at least one expandable element  88  positioned at the first end  86 . 1  of the stem  86  and configured to occupy a retracted state, as illustrated in  FIG.  6 A , in which the expandable element  88  can be inserted into the recess  82 , and a deployed state, as illustrated in  FIG.  6 B , in which the expandable element  88  cooperates with the recess  82  and makes it possible to temporarily link the stem  86  and the shutter  54  to displace it in two opposite directions longitudinally and a control  90  configured to switch the expandable element  88  from the retracted state to the deployed state or vice versa. 
     According to one configuration, the control  90  is positioned at the second end  86 . 2  of the stem  86 . 
     According to one embodiment, the expandable element  88  comprises at least two arms  92 ,  92 ′ each having a first end  92 . 1  linked to the stem  86  by an articulation  94  and a free second end  92 . 2 . According to one configuration, the stem  86  has a longitudinal axis A 86  linking its first and second ends  86 . 1 ,  86 . 2 . Each articulation  94  comprises a pivoting axis at right angles to the longitudinal axis A 86  and spaced apart therefrom, the pivoting axes of the different arms  92 ,  92 ′ being distributed about the longitudinal axis A 86  such that the arms  92 ,  92 ′ pivot in planes passing through the longitudinal axis A 86  and evenly distributed about the latter. 
     According to one arrangement, the checking tool  85  comprises three arms  92 ,  92 ′,  92 ″ pivoting in planes forming between them an angle of 120°. 
     According to one embodiment, each arm  92 ,  92 ′,  92 ″ comprises, at its free second end  92 . 2 , a block  96  configured to cooperate with the counterbore  84  of the recess  82 . 
     According to one configuration, the stem  86  is hollow. In addition, the control  90  comprises a rod  98  sliding in the stem  86  and having a first end linked to the arms  92 ,  92 ′,  92 ″ and a grippable second end protruding from the second end  86 . 2  of the stem  86 . The second end of the rod comprises a head  100  to facilitate the manipulation of the rod  98 . 
     Thus, by sliding the rod  98  in the stem  86  in at least one direction, it is possible to switch the arms  92 ,  92 ′,  92 ″ from the retracted state to the deployed state or vice versa. 
     According to a configuration visible in  FIG.  6 A , when the head  100  is away from the stem  86 , the arms  92 ,  92 ′,  92 ″ are in the retracted state. When the head  100  is brought close to the stem  86 , as illustrated in  FIG.  6 B , the aims  92 ,  92 ′,  92 ″ are in the deployed state. 
     Obviously, the invention is not limited to these embodiments for the checking tool  85 . 
     As illustrated in  FIG.  7   , the checking method comprises a step of insertion of the expandable element  88  of the checking tool  85 , in the retracted state, into the recess  82  of the shutter  54 , then, when the expandable element  88  is positioned in the recess  82  in line with the counterbore  84 , a step of activation of the control  90  to switch the expandable element  88  to the deployed state, as illustrated in  FIG.  8   . The expandable element  88  is then pressed against the counterbore  84 . The checking method comprises a step of verification of the operation and/or of unblocking of the drainage valve by displacing the checking tool  85  parallel to the longitudinal direction, in two opposite directions, in order to verify that the shutter  54  is not blocked and, if it is, notably in the open state, to unblock it by forcing it to translate toward the ring  50  using the checking tool  85 . After the operation verification and/or unblocking step, the checking method comprises a step of deactivation of the control  90  to switch the expandable element  88  from the deployed state to the retracted state, then a step of removal of the expandable element  88  from the recess  82 . 
     While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.