CA2022439C - Turbojet engine thrust reverser with flaps related to an upstream panel - Google Patents

Abstract

The pivoting doors (7) of a turbojet thrust reverser are associated with an upstream panel (20) connected to the door (7) by a rod (22), door (7) and panel (20) each pivoting around 'an independent pivot (27,28) carried by the fixed structure, under the action of a jack (7a). In the thrust reversal position, the panel (20) separated from the door (7) provides a passage and contributes to controlling the plies of the reverse flow. In the direct jet position, the internal cavity (16) of the door isolated from the vein by said panel (20) cooperating with the fixed upstream part (1) of the reverser and, downstream side, with the internal face of the door (7 ) at the level of seals is left at ambient pressure, which is exerted on the upstream part (11b) of the internal door element (11) (7) while the downstream part (11a) is subjected to vein pressure, so as to ensure self-closing of the door (7)

Description

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The present invention relates to a thrust reverser turbofan engine.
In this type of turbojet engine comprising a primary channel circulation of the so-called hot flow gases constituting a main ejection vein and annular channel, coaxial to the canal. primary, where so-called flow gases circulate cold, eg at the outlet of a blower located the entry of the turbojet engine, and constituting a vein secondary ejection, particularly when the rate of dilution is high, 1 ° reverse thrust implements mainly or only the flow diversion secondary cold.
Figure 1 of the accompanying drawings shows a known example of realization of a thrust reverser of this compound type of three main parts, a fixed part l, located in upstream, in the extension of the external wall of the canal secondary flow which is internally delimited pax °
the structural shell of the turbojet engine, a movable part 2 and a fixed rear ferrule 3. Said .fixed upstream part 1 includes an external panel 4 of nacelle, an internal panel 5 externally limiting the secondary flow vein and a front frame. 6 which ensures the junction of said panels 4 and 5. Said front frame 6 serves also supporting the device for controlling the displacements of the mobile part 2 which is. essentially composed of a number of movable elements, or obstacles commonly called gates 7, this number possibly vary according to particular applications, by example two, three or four doors 7 forming / a set annular, possibly in cooperation with a party fixed, depending on the method of mounting the power package constituted by the turbojet engine on the 1st plane.

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iJ 'J ~ G..t Ç., ~ .. ~: .. t Figure 2 shows, in a schematic view in pers, pec-Cive an example of application of such a changeover thrust to a turbofan engine, the reverser comprising in this case four doors 7 and 1a Figure 2 showing said doors 7, closed, corresponding to a direct push operation. Each door 7 is associated with a displacement control means such than a cylinder 7a.
Downstream of the fixed part 1, upstream and downstream being defined compared to the normal direction of circulation of gzz in direct push, the structure is extended by an edge deflection 8, fixed under the front frame 6 and intended for ensure adequate flow orientation, reverse thrust position. Each door 7 is composed of an external panel 9 coming to be placed in direct jet position in the extension of the panel external 4 of the upstream fixed part 1 to constitute the continuous aerodynamic wall limiting the external flow to motor represented by arrow 10, of an internal panel 11 and a lower structure formed by stiffeners 12, ensuring the connection between panels 9 and ll. Gate 7 is completed by a set of deflectors intended for channel the reverse flow when the reverser found in thrust reversal position and door 7 in open or deployed position. This set included in particular upstream of the door 7 a deflector 13 consisting of a front part which may or may not be associated with side parts. So that door 7, in position ' open growth reversal, ensures performance sufficient, it is usually necessary, as in the known example represented in FIG. 1, that the part front of inner panel 11 deviates in one direction external radial, of a theoretical surface represented by line I4, corresponds ~ .nt é a theoretical envelope perfect continuous aerodynamic delimitation 3 ",,., -; ~; 'ïl ~' ~~
;: d, J: ~, ~ ',''. e ,: ~~ 9 of the cJaz secondary flow vein, represented by the arrow 15. A cavity 16 is thus located. formed on the side inside of door 7 when it is in position closed corresponding to direct push, delimited, â
1 ° before, by the door deflector 13 and by the edge of deviation 8 of the upstream fixed part 1, on the external side, by the front part of the internal door panel 11 and the radially internal side, by said theoretical surface 14.
Part of the flow is forced by the deflection edge 8 in said cavity 16, thereby creating a distortion of the flow and disturbances in the flows. I1 results aerodynamic losses which are harmful to the direct push operation.
Other examples of embodiment of the type of reverser thrust of overhead doors turbojet are described in particular by FR-A 2 486153, FR-A 2 506 843 and FR-A 2 559 838. Solutions have also been proposed for an improvement in the vein profile corresponding to a correct aerodynamic vein envelope in function-direct pushing.
In particular, FR-A 2 621 082 defines an inverter door comprising a movable internal part adapting to the profile vein during direct push erg operation, thus masking said cavity l6, w while retracting laws operation in reverse thrust to obtain the performance required.
In all of these known examples, the inverter door 7 is provided around its periphery with sealing means, in particular.
on the edge of its external panel 9, like element 17 shown in Figure 1 cooperating with the fixed part upstream 1 of the reverser and likewise on the lateral edges cooperating with the beams 18 visible in FIG. 2.

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~ û,: a jx ,,,>, ~, Another problem concerns the control of the reverse jet during of operation. in reverse thrust. FP.- ~ A 2559 838 cited above a. looked for a solution in various adjustments made to the shape of the edges of the well reversal cleared in the cowling during opening doors of the inverter. We also know using it for this purpose. a set of deflectors associated with each door, such as the front deflector 13 shown in Figure 1. however in some applications, these previously known arrangements may not be sufficient to provide performance required.
I1 is also known, in order to avoid opening inadvertent reverser door likely to interfere with good aircraft behavior outside the phases approach, landing or braking, plan means of devices known per se locking positive door mechanics in closed position. It is.
however appeared desirable, in particular for long distance twin engine applications, to obtain a self-closing of the door whatever ~ 5 the state and position of normal closing devices and locking. Consequently, the object of the invention is provide a solution to these problems by reconciling ease of implementation, taking into account the requirements minimum mass, reduced overall dimensions which are important criteria in aeronautical applications affected and reduced cost; with obtaining required performance, both during operation in direct thrust, avoiding aerodynamic losses, that when operating in reverse thrust providing adequate control of the sheets of the reverse flow.
The invention finally aims particularly, in addition to the choices t ~~ ::: ological ensuring the reliability of the material, â

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5 movable such as the reverser doors in case of accidental unlocking.
C: eS goals are achieved, according to the invention, by a thrust reverser with pivoting doors of the aforementioned type characterized in that the point of api> lication of said cylinder which is arranged in the direct jet position. of the inverter between said door and, said internal upstream panel is located on the door, in that the connecting means between said door and said internal upstream panel comprise at minus a link, the hinges ~ s each end of said rod, the length of rod- ~ e and 1 ° location of said door and panel pivots being determined so that in reverse flow position a passage is provided between the internal door element and said panel whose inclinations associated with the provision door deflector layers of the reverse flow and only in direct jet position said internal upstream panel was connected with interposition sealing means on the one hand, at the front on the part fixed upstream of the reverser ~ t on the other hand, at the rear on the rear edge of the amon- ~ part of 1 ° internal element of door, the upstream cavity formed between said upstream panel internal and the internal door part being thus carried â
the ambient pressure which is lower than the pressure of the vain acting on the downstream part of the element in dull doorway so that given the determined position of pivots, efforts in the direction of self-closing have a positive effect on said door, the closed position of the door becoming a posi-stable anion.
Other characteristics and advantages of the 1st invention :, ~ oa ::! ~ '~: ._': ~: â

will be. better understood on reading the description that goes follow an embodiment of the invention, by reference to the accompanying drawings on which.
- Figure 1 shows a schematic half-view, in longitudinal section through a plane passing through the axis of rotation of an associated turbojet engine, push with pivoting doors, in the closed position, known type and which was previously the subject of a description;
- Figure 2 shows a schematic view in perspective of a thrust reverser of the aforementioned type shown in mounted position and with doors closed;
- Figure 3 shows, in a view similar to that of FIG. I a thrust reverser with pivoting doors, in the closed position, according to one embodiment of the invention;
- Figure 4 shows, in a view similar to that of FIG. 3, the cutting plane being offset, the reverser of thrust represented in FIG. 3 comprising means connecting an internal upstream panel to the door inverter;
- Figure 5 shows, in a schematic view similar to those of FIGS. 1 and 3, the reverser of thrust according to the invention in a position reverse thrust, showing the position of the doors and movable panels.

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w 7 According to one embodiment of the invention, represented on Figure 3, a susce.pti.ble thrust reverser to perform in the relevant flight phases of an airplane reversing the secondary flow of an associated turbojet â double flow, comprises the sets and. pieces that have.
previously described with reference to Figure 1 in a known example of implementation and we will keep the same references of these elements when they are. identical or correspondents. thrust reverser thus comprises the upstream fixed part 1 composed of the external panel 4 of nacelle, from the external panel 5 da vein of the secondary flow represented by arrow 15, panel at the downstream end is extended by the deflection edge 8 and the front frame 6 forming the support of the jack 7a, then the movable part 2 consisting of doors?, each composed of one element external 9 constituting the delimiting wall aerodynamics of the flow outside the engine represented by the arrow 10 when the door 7 is in the closed position, of an internal element 17. of the internal structure Z2 and of all the deflectors including in particular the front deflector 13 and finally the fixed rear cone 3.
in the closed position of part 7, corresponding to the direct thrust operation of the thrust, the theoretical surface 14. shown in the figure 1 of the known example and corresponding to the envelope theoretical continuous aerodynamics of the flow vein secondary is materialized, between the internal face of the panel 5, upstream, and the internal face of the rear cone fixed 3, downstream, on the one hand, by the internal surface 19 of the downstream part 11a of the internal door element 11 and, on the other hand, by the internal surface 20a of a panel upstream .int.erne 20 which doubles the upstream part llb of the internal door element 11 thereby closing the cc ~ -h.é
internal the upstream cavity 16 formed between said. panel 20 , r, ~> s ~~
g 6a '': s ~. ~ F: rr ~ e. ~,: r and. door 7.
Remarkably and. according to the invention, the seal.
seal 17 shown in the previous example of La Figure 1 and arranged between the upstream edge. from door 7 and the upstream fixed structure 1 of the reverser ai ~ re removed, thus putting the cavity 10 in relation to the pressure outdoor ambient. On the downstream side, however, a joint seal 21 is maintained between the edge <~ back of 1a downstream part 11a of the internal element 11 of part and the rear cone 3. The mounting of the internal upstream panel 20 is schematically shown in Figure 4. A link 22 connects an articula- ~ ian 23 integral with said panel 20 and an articulation 24 integral with the upstream part llb of the internal door part 11. A joint. sealing 25 is interposed between the upstream edge. said. panel 20 and the upstream fixed structure 1 and likewise a seal 26 is also interposed between the downstream edge of said panel 20 and the connection area on the rear edge of the upstream part llb of the internal door ll, of so that in the position corresponding to the direct thrust operation of the inverter shown in Figure 4, the upstream internal part llb of door 7 is subjected to an ambient pressure which reigns in cavity 16 while the pressure of the vein fluid circulating in the annular channel of the reverser is exerted on the internal face of the internal downstream part lla from door 7.
In a manner known per se, each door 7 is supported on its lateral edges by. pivot pan. fixed 27 carried by the fixed structure of the reverser, in particular by the edge of a longitudinal beam 18 as shown in 1a Figure 2. Similarly, the internal upstream panel 20 , 1. r1 ~ 7 c: ~; : ~ s ~~ r __ 9 ~,;,. ~ '~ I
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associated with each part 7 is. supported by a pivot independent. fixed 28 also / carried by the fixed structure.
These pivots 27 and. 28 are associated in known manner with support fittings, on both sides. else, according to terms which have not been shown in detail on the drawings.
We will give, with reference to FIG. 5, a description summary of the operation of the thrust reverser which has just been described with reference to Figures 3 and 4. For go from the closed position of the reverser door 7,, as shown in Figures 3 and ~. and corresponding to direct push operation at a opening of door 7, shown in FIG. 5 corresponding to the closure of the secondary channel and a reverse thrust, cylinder 7a, actuated by a system control, of a type known per se and not shown in the drawings, by moving its articulation 29 on door 7, shown in Figure 3, rotates said door around its pivots 27 until the downstream edge 7b of the door come to join the surface of the inner envelope 30 of the annular channel of the vein secondary stream. In this movement. pivoting the door 7 drives through the link 22 1st upstream panel 20 which pivots around its own pivots 28 so as to spare on either side of the panel 20 reverse flow passage channels.
The orientation of the flow in particular ensured by the c ~ reflector ~
front 13 of section 7 deflecting the jet vars the front is improved thanks to the control of the reverse flow layers which East. thus ensured by the panel 20 thanks to various additional provisions adapted to the results sought based on particular applications.

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These results are notably. influenced by the choice of respective positions of the door pivots 27 and 28 da 5 panel and by the particular profile, in particular on its external face, given to panel 20.
By referring. in Figure 4, in the position of direct thrust operation, an will also raise a 10 advantage from the invention. Indeed, as noted previously, owing to the absence of a sealing jaint at the front edge of door 7, but the presence by against such joints 25 and 26 at the edges of the panel internal lover 20, an imbalance of efforts exerted on part 7 is created. Internal pressure efforts of the fluid vein acting on the downstream internal part lla of door 7 are not compensated by efforts acting on the upstream part 11b of the faït that the cavity 16 is at ambient pressure. T1 results in a tendency to self-close door 7 whose position closed is stable, thus avoiding any risk of opening inadvertent in the event of accidental unlocking, or in the case of rupture, said part being. otherwise equipped usual locking / unlocking devices.
We also note that the distribution thus obtained of pressures on the upstream part. llb and on the downstream part lla of the internal element 11 of part allows a reduction loads and a reduction in the effort required from the cylinder 7a, which allows a reduced dimensioning and a advantageous reduction in size.

Claims (5)

1. A turbojet thrust reverser having a structure deployed along a longitudinal axis and defining at least one lateral opening, the structure defining an external surface and a area internal located upstream of said lateral opening, and an external surface and an internal surface located downstream of said lateral opening, said surfaces defining a theoretical surface of gas flow at a pressure higher than the outside ambient atmospheric pressure, the inverter thrust including:
a) a thrust reverser door having an internal door element defining an upstream part and a downstream part;
b) a first pivoting attachment means for attaching the inverter door to the structure in such a way that the inverter door pivots around a first pivot between a closed position, in direct push, in which the inverter door covers said lateral opening, and a position open, in reverse thrust, in which the inverter door uncovers said lateral opening and directs the gas flow towards the outside by said lateral opening;
c) a deflector panel having an internal surface;
d) a second pivoting attachment means for attaching the deflector panel to the structure in such a way that the deflector panel pivots around a second pivot between a closed position and an open position;

e) a coupling means operatively connecting the panel deflector and the inverter door so that when the door switch is in the closed position, the deflector panel is also in closed position, where the internal surface of the deflector panel and the element door internal are substantially contiguous to internal surfaces upstream and downstream of the structure, and where a cavity is delimited by the part upstream of the inverter door, the deflector panel and the structure, and when the inverter door is in the open position, the panel deflector is also in the open position;
f) an operating means operatively interposed between the structure and the inverter door in order to move the inverter door between the position closed and the position open, the actuating means being directly attached to the inverter door;
g) a means allowing the cavity to communicate with the atmosphere ambient so that the ambient atmospheric pressure acts on said upstream part; and h) sealing means interposed between the deflector panel and the structure, and between the deflector panel and the inverter door in order to cut the communication between the gas flow and the cavity, so that the pressure of the gas flow acts only on said downstream part, thus exerting a resultant force on the inverter door caused by the pressure difference between the gas flow and the ambient atmosphere forcing the inverter door in the closed position. 2. A thrust reverser according to claim 1 in which the first and second pivot axes are located in such a way that open position, the deflector panel and the inverter door define a passage between them to stratify and control the reverse thrust gas flow, 3. A thrust reverser according to claim 1 wherein first and second pivot axes are spaced along the longitudinal axis. 4. A thrust reverser according to claim 1 wherein the first and second pivot axes are parallel. 5. A thrust reverser according to claim 1 in which the coupling means includes:
a) at least one link having first and second extremities;
b) a first articulation means serving to connect said first end the deflector panel; and c) a second articulation means serving to connect said second end at the inverter door.