The present invention relates to the production of air intakes for nacelles containing the engine group, particularly for a jet engine, for aircraft.
The nacelle has a substantially annular cross-section and defines between it and a central portion of the engine an annular so-called fan channel.
The wall of the nacelle defining the fan channel is treated acoustically and constitutes a sandwich formed from a central cellular core flanked, on the fan channel side, with an acoustically resistive layer and, on the other side, with a total reflector.
This wall is conventionally formed of several sectors or segments, generally three or four, butted together by clipping to constitute a substantially annular conduit.
It is also known to produce air intakes with the help of two clipped panels, substantially semicircular in cross-section, with the help of a mold having the shape of half of an air intake. This technology could be pursued to its limit so as to produce a fan channel panel that is not only of one piece but also without clips, if the shape of such a panel permitted demolding without disassembly or destruction of the mold, which is not the case, the wall of a fan channel being almost always of a re-entrant shape.
The present invention has precisely for its object the provision of tooling for molding with keys, permitting particularly the production of air intakes without clips.
In the present description, an air intake without clips is formed of a panel of a substantially tubular shape constituted by a sandwich comprising a central cellular core, a total reflector and a resistive layer disposed on the internal surface of the panel, said internal surface comprising no connections nor clips that could disturb the acoustic damping of the panel.
To this end, the invention has for its object tooling for molding with keys for the production in particular of air intakes without clips of substantially tubular shape, comprising:
According to a preferred embodiment, the tooling comprises:
The device for controlling the displacement of the sectors is constituted for example by a structure for receiving the mandrel in vertical axial position, comprising:
Such a mandrel, once shaped, which is to say with its sector panels abutted and locked and provided with its flanges, can be disposed horizontally on a device for driving it in rotation so as for example the emplacement of draping, winding or banding of the elements or elements constituting the acoustically resistive layer of a panel of a monobloc fan channel without clips, then for the emplacement of other constituent elements of the panel.
For polymerization, either of the single resistive layer, or of the assembly of sandwiches constituting the panel as well as if desired to carry out the steps of baking or welding in complement of said polymerization, the mandrel is retrieved and placed in the oven or autoclave after withdrawal or not of the flanges.
To recover finally the panel, the flanges are (if desired) returned into position on the mandrel which is thus positioned vertically on the mounting/unmounting device of the mandrel.
The device is, after unlocking of the key sector, actuated so that in the first place it is moved in translation inwardly of the key sector, then, in the second instance, pivoting inwardly the two articulated sectors so as to disengage these three sectors from the air intake panel thus produced, which can then easily be withdrawn.
The device can then be actuated by a reverse process to reconstitute a mandrel in such shape as to produce another panel.
Other characteristics and advantages will become apparent from the description which follows, of one embodiment of the mandrel and its associated tooling, which description is given solely by way of example and with respect to the accompanying drawings, in which:
In
The mandrel 1 is of generally tubular shape and constituted by four sections or sectors, namely a so-called fixed sector 2 on opposite sides of which are associated two identical sectors 3, called articulated sectors because they are connected to the fixed sector 2 each by a pair of hinges 4.
The fourth sector 5, called the key sector, is an independent sector interposed between the two articulated sectors 3. It is lockable in place on the two adjacent sectors 3 by locks 6 (
Sectors 2, 3, 5, in the molding position of the mandrel 1, define an external surface which corresponds to the internal wall in contact with the air flow which enters the fan channel of the air intake panel to be produced.
The placing of the mandrel in the un-molding configuration (
The mandrel 1 is inserted between two end flanges 9a, 9b, connected by ties 10, the flanges bearing by their periphery on the sector of the sections.
Along the axis of mandrel 1, on the external surface of the flanges 9a, 9b, are arranged sockets 11 permitting the transport of the mandrel and its emplacement on a device for driving in rotation (not shown) of the mandrel 1 about its axis disposed for example horizontally.
In
The locks 6 of the key sector 5 are fixed on reinforced lateral uprights 14′ and coact with keepers 7 also fixed on reinforced lateral uprights 14″ of the articulated section 3.
Moreover, as can be seen in
The lock 6 is carried by a plate 18 itself fixed to the lateral upright 14′ of the key sector 5.
The latch 19 of the lock passes through the wall of the upright 14′ and that of the lateral upright 14″ of the sector 3 and engages in the keeper 7.
The latch 19 is moved with the help of means described later with reference to
These means comprise a tubular steel chassis 20 of generally octagonal shape, defining a first movement track 21 diametral to the octagonal structure, flanked by two symmetrical movement tracks 22, converging in a direction substantially from one of the ends of said first track 21.
The track 21 is defined by two horizontal parallel beams 23.
At one of the ends of the track 21 is fixed on the beams 23 a crosspiece 24 carrying two pins 25 adapted to support and center in vertical position the fixed sector 2 of the mandrel. To this end, in the lower portion of the sector 2 (
From the other end of the beams 23 and on their upper surface are fixed two rails 27 extending substantially over a little more than half of the length of said beams.
On the rails 27 move, by means of shoes 28 (
The carriage 29 is moved by a screw 33 driving a nut 34 secured to the carriage 29.
The screw 33 turns in the carriage 20 and is provided at its external end with a return angle 35 for controlling the screw either manually or by pneumatic screwing.
The carriage 29 carries a post 36 supporting two devices for actuating two pairs of locks 6.
Each device comprises a control rod constituted by two lateral returns 37 whose ends in the form of hooks 38 coact with the complementary ends 39 (
The locks 37 are articulated on a head 40 movable vertically in guide slides 41 fixed to the post 36, under the action of the rod 42 of a jack 43 also fixed to the post.
The ends 38 of the returns 37 are held by guides 44 secured to the post 36.
At the hood of the post is disposed, fixed to the carriage 29, a second jack 43′ (
Each track 22 comprises two parallel beams carrying two rails 45 on which circulate by means of shoes a carriage 46 moved, like the carriage 29, with the help of a screw 47 provided with an angle return 48.
Each carriage 46 carries a drive and guide pin 49 adapted to be received in a suitable throat (not shown) provided at the lower end of each articulated sector 3.
In
In this position of the carriage 29, the returns 37 of the actuating devices for the locks 6 are located in the vertical plane defined by the four locks 6.
To pass from the un-molding position of the mandrel 1 of
When the carriage 29 has reached its maximum retracted position, and even a little before this position is reached, the carriages 46 can be actuated, simultaneously or not, to cause to pivot inwardly the articulated sectors 3 by rotation about the axis of the hinges 4, the sectors being driven by the pins 49.
The sectors of the mandrel being thus positioned, it is easy to withdraw the molded envelope 8 (
The screws 33 and 47 are preferably controlled automatically by a control device (not shown) synchronizing the movements of the carriages 29, 46 to accelerate the manipulation, but said screws 33, 47 can be controlled manually with the help of a crank for example.
To reconstitute the mold, the reverse series of movements is carried out.
Once the mandrel has been shaped, after blocking the locks 6, the control devices (37, 38) of said locks can be loosened and there can be removed from the chassis 20 the mandrel 1 which is self-supporting thanks to the locked key sector 5, to provide it with the flanges 9a, 9b for transport and rotation.
The mandrel 1 is replaced on the chassis 20, either after polymerization of the resistive layer so as to recover this latter, the other elements of the sandwich defining the air intake panel being emplaced according to other techniques, or after final polymerization of said sandwich, so as to recover the panel for its finishing, all the elements of the panel being emplaced on the mandrel from the outset.
There has been described above a preferred embodiment of the mandrel with keys, but it is to be noted that the mandrel according to the invention can comprise a number of sectors different from four, namely a lesser number, essentially three sectors, or a greater number, particularly five sectors.
In the version with three sectors, shown in
In the five sector version, shown in
In the molding position, the sectors S4 to S7 abut. In the un-molding position of the mandrel, the articulated sectors S4 to S7 are first folded toward the center of the mandrel as shown at S′ 4 to S′ 7 in
Generally speaking, and no matter what the number of sectors, the mandrel comprises an independent and movable key sector, the other sectors being articulated to each other or movable so as to be retractable inwardly of the mandrel.
Number | Date | Country | Kind |
---|---|---|---|
02 08014 | Jun 2002 | FR | national |
Number | Name | Date | Kind |
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1835986 | Heston | Dec 1931 | A |
4278490 | Pistole et al. | Jul 1981 | A |
4436574 | Long et al. | Mar 1984 | A |
4610422 | Kraiss | Sep 1986 | A |
Number | Date | Country |
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1 262 570 | Mar 1968 | DE |
1 504 597 | May 1969 | DE |
2 259 690 | Jun 1974 | DE |
23 52 373 | Apr 1975 | DE |
0184759 | Mar 1958 | EP |
Number | Date | Country | |
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20040065775 A1 | Apr 2004 | US |