PNEUMATIC DE-ICING SYSTEM FOR AN AIRCRAFT

Abstract

A pneumatic de-icing system (10) for an aircraft, this system (10) comprising a stack of layers including: - a support layer (12) adapted to cover a part of the aircraft, - an outer layer (14) opposite the support layer (12) and adapted to be elastically deformed to detach the ice on this outer layer (14), - a first layer (16) of first inflatable cells (18) interposed between the support layer (12) and the outer layer (14), and - at least one second layer (20) of second inflatable cells (22) embedded in the first layer (16) and the support layer (12) and connected to the first layer (16) by the same connecting lines (L1, L2, …, Ln) delimiting the contours of the first and second cells (18, 22). Figure for the abbreviation: Figure 1

Description

Title of the invention: PNEUMATIC TYPE DE-ICING SYSTEM FOR AN AIRCRAFT Technical field of the invention

[0001] The present invention relates to a pneumatic type de-icing system for an aircraft, as well as a method for manufacturing such a system. Technical background

[0002] A de-icing system is intended to equip the wings, tail assemblies, engine air intakes or other similar parts belonging to aircraft such as airplanes or helicopters.

[0003] It is known that when these aircraft cross areas where weather conditions are harsh and unfavorable, frost can form in particular in the more or less long term on these aerodynamic surfaces.

[0004] This ice buildup can subsequently lead to increased weight and a change in the wing's aerodynamic profile, potentially altering the aircraft's lift and drag, and therefore its flight behavior. Thus, these surfaces can be equipped with electric or pneumatic de-icing systems.

[0005] An electric defrosting system generally comprises electric heating elements. A pneumatic defrosting system generally comprises an inflatable bladder, and the invention relates to this latter case.

[0006] A pneumatic de-icing system generally comprises a flexible envelope which at least partially covers the aerodynamic surface to be protected from frost and which can be inflated to change its shape or profile.

[0007] Thus, when frost forms on the aerodynamic surface, pressurized gas is sent into the envelope. The envelope then undergoes a sudden expansion which causes the frost layer to break into a plurality of pieces, and then ejects these from the surface.

[0008] In the current technique, a de-icing system comprises a stack of layers including:

[0009] - a support layer suitable for covering the aircraft part to be protected from frost,

[0010] - an external layer opposite to the support layer and capable of defining the surface aerodynamics on which frost is likely to form, and

[0011] - a layer of inflatable cells intercalated between the support layer and the layer external.

[0012] This cell layer is connected to a gas passage port for supplying gas to the cells, as well as for evacuating gas from the cells.

[0013] The cells are arranged next to each other in the cell layer.

[0014] However, when the cell layer malfunctions, the entire de-icing system malfunctions. One solution to this problem is to divide the cell layer into several independent networks, each network comprising its own cells and connected to its own gas passage port. The cell networks are distributed throughout the cell layer, and when one of the cell networks malfunctions, the other cell network(s) can continue to be used because they operate autonomously.

[0015] However, this degraded mode of operation is not optimal because, insofar as the cells of the different networks are distributed within the same layer, it is understood that the areas of the aerodynamic surface corresponding to the non-functional cells will not be inflated and therefore cannot be separated from the frost.

[0016] The present invention offers a simple, effective and economical solution to this problem. Summary of the invention

[0017] The invention relates to a pneumatic de-icing system for an aircraft, this system comprising a stack of layers including:

[0018] - a support layer suitable for covering a part of the aircraft,

[0019] - an outer layer opposite to the support layer and capable of being deformed elastically to detach the frost on this outer layer,

[0020] - a first layer of first inflatable cells intercalated between the layer of support and the outer layer, this first layer being connected to at least one first gas passage port at the level of the support layer, the first cells being arranged next to each other in the first layer, the first cells being formed between two sub-layers or superpositions of sub-layers which are connected to each other along bond lines so as to delimit the contours of the first cells,

[0021] characterized in that it further comprises:

[0022] - at least one second layer of inflatable second cells embedded in the first layer, this second layer being connected to at least one second gas passage port at the level of the support layer, the second cells being able to be supplied with gas by said at least one second port independently of the supply of gas to the first cells by said at least one first port, the second cells being formed between two sub-layers or superpositions of sub-layers which are connected to each other along the same bond lines as the first layer so as to delimit contours of the second cells which are identical to the contours of the first cells.

[0023] The invention thus proposes a redundancy of the cell layer, that is to say, the de-icing system comprises two or more superimposed and independent cell layers. The first layer of cells operates autonomously and may comprise one or more independent cell arrays. Similarly, the second layer of cells operates autonomously and may comprise one or more independent cell arrays. The first cells may be inflated without the second cells being inflated or simultaneously with the second cells. The distinctive feature of the invention lies in the fact that the connecting lines that define the contours of the first cells are the same as the connecting lines that define the contours of the second cells.For this reason, the second cells are located directly beneath the first cells and can even be considered as nested or embedded within them. Combining the second cells with the first cells, or integrating them within the first cells, is advantageous for several reasons. The second layer of cells can serve as a backup, used only when the first layer malfunctions. It can also be used interchangeably with the first layer to avoid excessive stress on the first layer and thus extend its lifespan. Furthermore, because the layers are integrated within each other, even if the first layer fails, the second layer can inflate the entire aerodynamic surface to be protected without the risk of leaving uninflated areas, as was the case with previous techniques.

[0024] The system according to the invention may comprise one or more of the following features or steps, considered independently of each other or in combination with each other:

[0025] - the first layer comprises:

[0026] - a single first gas passage port, the first cells all being connected connected to each other to form a single first network of cells linked to the single first port, or

[0027] - two or more initial gas passage ports, the initial cells being distributed in two or more first cell networks, the first cells of each network being connected to each other and to one of the first ports, the first networks being capable of being supplied with gas by said first ports independently of each other;

[0028] - the second layer comprises:

[0029] - a single second gas passage port, the second cells all being connected connected to each other to form a single second cell network linked to the single second port, or

[0030] - two or more secondary gas passage ports, the secondary cells being distributed in two or more secondary cell networks, the secondary cells of each network being connected to each other and to one of the secondary ports, the secondary networks being capable of being supplied with gas by said secondary ports independently of each other;

[0031] - the first cells each have a generally elongated shape and extend parallel to each other, and in which the second cells each have a general elongated shape and extend parallel to each other;

[0032] - the number of the first cells is identical to the number of the second cells;

[0033] - the second cells are housed respectively in the first cells of so that each of the first cells includes one of the second cells;

[0034] - the first cells are separated from the second cells by a single sub- layer ;

[0035] - the first and second connecting lines are formed by stitching;

[0036] - the first and second connecting lines are formed by welding;

[0037] - the layers or superpositions of sub-layers that form the second cells are made of thermoplastic;

[0038] - the first and second ports are at least partly perpendicular to the layer of support.

[0039] The present invention also relates to an aircraft equipped with at least one de-icing system as described above. Brief description of the figures

[0040] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0041] [Fig. 1] is a very schematic cross-sectional view of an embodiment of a defrosting system according to the invention, and

[0042] [Fig.2] is a very schematic cross-sectional view of an alternative embodiment of a defrosting system according to the invention.

[0043] [Fig. 3a] is a very schematic view, for example from above, of a defrosting system according to the invention,

[0044] [Fig. 3b] is a very schematic view, for example from above, of a variant of the defrosting system according to the invention,

[0045] Figure 4 is a schematic cross-sectional view of an embodiment of a defrosting system according to the invention.

[0046] Figures 5a-5b show the first steps of a process according to the invention for manufacturing the defrosting system of the [Fig.4],

[0047] [Fig.6] shows another step of the process according to the invention for manufacturing the defrosting system of [Fig.4],

[0048] [Fig.7] shows another step of the process according to the invention for manufacturing the defrosting system of [Fig.4],

[0049] [Fig.8] shows another step of the process according to the invention for manufacturing the defrosting system of [Fig.4],

[0050] [Fig.9] shows another step of the process according to the invention for manufacturing the defrosting system of [Fig.4],

[0051] [Fig. 10] shows another step of the process according to the invention for manufacturing the defrosting system of [Fig. 4],

[0052] Figure 11 shows several operating stages of the defrosting system according to the invention, according to a first mode, and

[0053] [Fig. 12] shows several operating stages of the defrosting system according to the invention, according to a second mode. Detailed description of the invention

[0054] Fig. 1 represents the general principle of the invention, which is the presence of two layers of inflatable cells within the same de-icing system 10, and the fact that first inflatable cells contain second inflatable cells.

[0055] The defrosting system 10 is pneumatic and comprises a stack of layers including:

[0056] - a support layer 12 suitable for covering a part of the aircraft,

[0057] - an outer layer 14 opposite the support layer 12 and capable of being deformed elastically to detach the frost on this layer 14,

[0058] - a first layer 16 of first inflatable cells 18 intercalated between the support layer 12 and outer layer 14, and

[0059] - at least a second layer 20 of nested inflatable second cells 22 in the first layer 16 and preferably embedded in the first inflatable cells 18.

[0060] The first layer 16 is connected to at least one first gas passage port 24, this or these first port(s) 24 being located at the level of the support layer 12.

[0061] The second layer 20 is connected to at least one second gas passage port 26, this or these second port(s) 26 being located at the level of the support layer 12.

[0062] In the example shown, ports 24, 26 are next to each other or to each other.

[0063] Ports 24, 26 are for example made of metal (such as aluminum alloy) or thermoplastic.

[0064] The first cells 18 are arranged next to each other in the first layer 16, and the second cells 22 are arranged next to each other in the second layer 20.

[0065] It is understood that the first cells 18 are supplied with gas by the port or ports 24, independently of the supply of gas to the second cells 22 by the port or ports 26.

[0066] It is important to note that the surface of the part which is intended to be covered by the defrosting system 10 is not necessarily flat and therefore the defrosting system 10 is not necessarily flat in its final operating position.

[0067] For example, when the surface to be protected from frost is a leading edge of a wing or an air intake, it is understood that the de-icing system 10 follows the shape of this surface and therefore has a generally curved shape.

[0068] Although the examples illustrated in the drawings show flat layers, it is understood that these layers can have another shape and in particular any shape.

[0069] In [Fig.1], the first layer 16 comprises a single first gas passage port 24, and the first cells 18 are all connected to each other to form a single first RI network of cells 18 connected to the single first port 24.

[0070] In this same [Fig.1], the second layer 20 comprises a single second gas passage port 26, and the second cells 22 are all connected to each other to form a single second network RI' of cells 22 connected to the single second port 26.

[0071] The first cells 18 may each have a generally elongated shape and extend parallel to each other. Similarly, the second cells 22 may each have a generally elongated shape and extend parallel to each other. The first cells 18 may extend parallel to the second cells 22.

[0072] Each of the first cells 18 can communicate with at least one adjacent first cell 18 by its longitudinal ends, and each of the second cells 22 can communicate with at least one adjacent second cell 22 by its longitudinal ends.

[0073] As illustrated, the number of the first 18 cells can be identical to the number of the second 22 cells.

[0074] Advantageously, each of the first cells 18 contains one of the second cells 22, as in the example shown. That is to say, each second cell 22 is housed inside one of the first cells 18 and each of the first cells 18 contains one of the second cells.

[0075] It is understood that the dimensions of the first cells 18 can be greater than those of the second cells 22.

[0076] [Fig.2] is a view similar to that of [Fig.1] and illustrates an alternative embodiment.

[0077] In this [Fig.2], the first layer 16 may comprise two or more first gas passage ports 24, and the first cells 18 are distributed in two or more first cell arrays RI, R2.

[0078] The first cells 18 of each of the networks RI, R2 are connected to each other and to one of the first ports 24. The first networks RI, R2 are capable of being supplied with gas by the first ports 24 independently of each other.

[0079] The second layer 20 may include two or more second gas passage ports 26, and the second cells 22 are distributed in two or more second cell arrays RI', R2'.

[0080] The second cells 22 of each of the networks RI', R2' are connected to each other and to one of the second ports 26. The second networks RI', R2' are capable of being supplied with gas by the second ports 26 independently of each other.

[0081] In yet another variant, the first layer 16 could comprise a single port 24 and therefore a single network RI as in [Fig. 1], and the second layer 20 could comprise two or more ports 26 and therefore two or more networks RI', R2' as in [Fig. 2]. Alternatively, the first layer 16 could comprise two or more ports 24 and therefore two or more networks RI, R2 as in [Fig. 2], and the second layer 20 could comprise a single port 26 and therefore a single network RI' as in [Fig. 1].

[0082] In the embodiments and variants of the invention, the outer layer 14 may comprise a single layer or two or more superimposed sublayers 14a, 14b. In the example shown, it comprises two sublayers 14a, 14b. These sublayers 14a, 14b are, for example, made of elastomer but may comprise at least one fabric or braid.

[0083] The support layer 12 may comprise a single layer or two or more superimposed sublayers. In the example shown, it comprises a single layer, for example made of elastomer, but may include at least one fabric or braid.

[0084] The support layer 12 is here traversed by the ports 24, 26. Each of the ports 24, 26 can have a general tubular shape of which one section is projecting on the support layer 12, on the side opposite the external layer 14, and of which another section is engaged in the stack of layers for the purpose of the fluidic connection of its end to the corresponding cells 18, 22.

[0085] It can be seen in the drawings that the ports 24, 26 can be at least partly perpendicular to the support layer 12.

[0086] The first cells 18 are preferably formed between two sublayers 34, 36 or superpositions of sublayers which are connected to each other along first bond lines L1, L2, ..Ln so as to delimit contours of the first cells 18.

[0087] The second cells 22 are formed between two sublayers 38, 40 or superpositions of sublayers which are connected to each other along the same bond lines L1, L2, ..., Ln as the first layer so as to delimit contours of the second cells 22 which are identical to the contours of the first cells 18.

[0088] The connecting lines L1, L2, ..., Ln are preferably made by sewing or welding.

[0089] Fig. 3a is, for example, a top, bottom, or front view of a complete defrosting system 10. It is in the form of a flexible inflatable envelope that can be attached and glued to the surface of the part to be protected, for example.

[0090] In this [Fig.3a], the first layer 16 comprises a single first gas passage port 24, and the first cells 18 are all connected to each other to form a single first RI network of cells 18 connected to the single first port 24.

[0091] In this same [Fig.3a], the second layer 20 comprises a single second gas passage port 26, and the second cells 22 are all connected to each other to form a single second network RI' of cells 22 connected to the single second port 26.

[0092] It is also seen that the first cells 18 each have a generally elongated shape and extend parallel to each other, and that the second cells 22 each have a generally elongated shape and extend parallel to each other. Each of the first cells 18 communicates with at least one adjacent first cell 18 via its longitudinal ends, and each of the second cells 22 communicates with at least one adjacent second cell 22 via its longitudinal ends.

[0093] We also see that the first cells 18 extend parallel to the second cells 22.

[0094] As illustrated, the number and dimensions of the first cells 18 are identical to the number and dimensions of the second cells 22. In addition, the first and second cells 18, 22 are directly positioned one above the other.

[0095] Fig. 3b is a view similar to that of Fig. 3a of another defrosting system 10.

[0096] In this [Fig.3b], the first layer 16 comprises two or more first gas passage ports 24, and the first cells 18 are distributed in two or more first cell arrays RI, R2, R3.

[0097] The first cells 18 of each of the networks RI, R2, R3 are connected to each other and to one of the first ports 24. The first networks RI, R2, R3 are able to be supplied with gas by the first ports 24 independently of each other.

[0098] The second layer 20 comprises two or more second gas passage ports 26, and the second cells 22 are distributed in two or more second cell networks R1',R2',R3'.

[0099] The second cells 22 of each of the networks RI', R2', R3' are connected to each other and to one of the second ports 26. The second networks RI', R2', R3' are capable of being supplied with gas by the second ports 26 independently of each other.

[0100] It can also be seen that the first cells 18 each have a generally elongated shape and extend parallel to each other, and that the second cells 22 each have a generally elongated shape and extend parallel to each other. Each of the first cells 18 communicates with at least one adjacent first cell 18 by one of its longitudinal ends, and each of the second cells 22 communicates with at least one adjacent second cell 22 by one of its longitudinal ends. The drawing shows that the connection between the cells 18 of the same network RI, R2, R3 is such that this network has a serpentine shape, and that the connection between the cells 22 of the same network RI', R2', R3' is such that this network has a serpentine shape.

[0101] We also see that the first cells 18 extend parallel to the second cells 22.

[0102] As illustrated, the number and dimensions of the first cells 18 are identical to the number and dimensions of the second cells 22. Moreover, the first and second cells 18, 22 are directly positioned one above the other.

[0103] Reference is now made to [Fig.4] which illustrates a more concrete embodiment of a defrosting system 10.

[0104] The outer layer 14 comprises one layer or two or more superimposed sublayers 14a, 14b. In the example shown, it comprises two sublayers 14a, 14b. These sublayers 14a, 14b are, for example, made of elastomer.

[0105] The support layer 12 comprises a single layer or two or more superimposed sublayers. In the example shown, it comprises a single layer, for example of elastomer, but may include at least one fabric or braid.

[0106] The support layer 12 is here traversed by the ports 24, 26. Each of the ports 24, 26 can have a general tubular shape, a section 28 of which projects onto the support layer 12, on the opposite side to the external layer 14, and of which another section 30 is engaged in layer stacking for the purpose of the fluidic connection of its end to the corresponding cells 18, 22.

[0107] The second port 26 extends from the support layer 12 to the second layer 20 of second cells 22.

[0108] It can also be seen that the ports 24, 26 can be at least partly perpendicular to the support layer 12.

[0109] The first cells 18 are preferably formed between two sublayers 34, 36 or superpositions of sublayers which are linked together along first bond lines L1, L2, ..., Ln so as to delimit contours of the first cells 18, as can be seen in figures 1 to 4.

[0110] The second cells 22 are formed between two sublayers 38, 40 or superpositions of sublayers which are connected to each other along the same bond lines L1, L2, ..., Ln so as to delimit the contours of the second cells 22.

[0111] Reference is now made to Figures 5a to 10, which illustrate a manufacturing process for the de-icing system 10 of [Fig. 4]. In this manufacturing process, the different layers of the stack are considered to be made of elastomer or elastomer-based materials, or of fabric and thermoplastic.

[0112] The process includes a first step a) illustrated in figures 5a-5b of depositing or forming the outer layer 14 on a mold 44, and in particular the sub-layers 14a, 14b one after the other on the mold 44.

[0113] The process includes a step b) illustrated in figures 6 and 7 of preparing the first and second layers 16, 20 of inflatable cells 18, 22 and of depositing these layers 16, 20 on the outer layer 14.

[0114] The connecting lines L1, L2, ..., Ln are formed to delimit the cells 18, 22. These connecting lines are advantageously made by seams or welds which cross the corresponding layers.

[0115] The different layers or sub-layers of the first and second layers 16, 20 are stacked as illustrated in figures 6 and 7.

[0116] The assembly is then deposited on the outer layer 14 as illustrated in [Fig.8].

[0117] The process then includes a step c) illustrated in [Fig. 9] comprising the deposition or the formation of the support layer 12 on the first and second layers 16, 20.

[0118] Before or after step c), the ports 24, 26 are linked respectively to the first and second layers 16, 20, as illustrated in [Fig. 10].

[0119] After step c), the system is preferably subjected to vulcanization to solidify the stack of layers.

[0120] Figures 11 and 12 show two modes of operation of a defrosting system 10 according to the invention, these defrosting modes being applicable to all the variants described above.

[0121] In [Fig. 11], arrows F1 and F2 show nominal operation of the system 10 during which only the first layer 16 of cells 18 is inflated and used for de-icing. There is an alternation of supplying the cells 18 with pressurized gas and of extracting the pressurized gas and evacuating the cells, so that the cells 18 inflate and deflate at a predetermined rate.

[0122] Arrow F3 shows a failure of the first layer 16 such as for example a sealing defect or a leak from one of the cells 18.

[0123] In this case, arrows F4 and F5 show a backup operation of the system 10 during which only the second layer 20 of cells 22 is inflated and used for de-icing. There is an alternation of supplying the cells 22 with pressurized gas and of extracting the pressurized gas and evacuating the cells, so that the cells 22 inflate and deflate at a predetermined rate, replacing the first cells 18 which are no longer in use.

[0124] In [Fig. 12], the arrows show an alternating operation of the first and second layers 16, 20. The process thus goes from a non-inflated state, to an inflated state in which only the cells 18 are inflated, to a non-inflated state, then to an inflated state in which only the cells 20 are inflated, and finally to a non-inflated state. This cycle is repeated as many times as necessary at a predetermined rate.

[0125] From a dimensional point of view, the cells 18, 22 can have a length of up to one meter or more, and a width of several centimeters. The cells are separated from each other by a distance less than or equal to 1 cm, for example, which corresponds to the width of the connecting lines between the cells.

Claims

Demands

1. A pneumatic de-icing system (10) for an aircraft, said system (10) comprising a stack of layers including: - a support layer (12) adapted to cover a part of the aircraft, - an outer layer (14) opposite the support layer (12) and adapted to be elastically deformed to detach the ice on this outer layer (14), - a first layer (16) of first inflatable cells (18) interposed between the support layer (12) and the outer layer (14), this first layer (16) being connected to at least one first gas passage port (24) in the support layer (12), the first cells (18) being arranged side by side in the first layer (16), the first cells (18) being formed between two sub-layers (34, 36) or superpositions of sub-layers which are connected to each other along connecting lines (L1, L2, ..., Ln) so as to delimit contours of the first cells (18), characterized in that it further comprises: - at least one second layer (20) of inflatable second cells (22) nested in the first layer (16), this second layer (20) being connected to at least one second gas passage port (26) at the level of the support layer (12), the second cells (22) being capable of being supplied with gas by said at least one second port (26) independently of the supply of gas to the first cells (18) by said at least one first port (24), the second cells (22) being formed between two sub-layers (38, 36) or superpositions of sub-layers which are connected to each other along the same connection lines (L1, L2, ..., Ln) as the first layer so as to delimit contours of the second cells (22) which are identical to the contours of the first cells (18).

2. A de-icing system according to claim 1, wherein the first layer (16) comprises: - a single first gas passage port (24), the first cells (18) all being connected to each other to form a single first network (IR) of cells connected to the single first port (24), or - two or more first gas passage ports (24), the first cells (18) being distributed in two or more first networks of cells (RI, R2), the first cells (18) of each of the networks (RI, R2) being connected to each other and to one of the first ports (24), the first networks (RI, R2) being able to be supplied with gas by said first ports (24) independently of each other.

3. De-icing system according to claim 1 or 2, wherein the second layer (20) comprises: - a single second gas passage port (26), the second cells (22) all being connected to each other to form a single second cell network (RT) connected to the single second port (26), or - two or more second gas passage ports (26), the second cells (22) being distributed in two or more second cell networks (RT, R2'), the second cells (22) of each of the networks (RT, R2') being connected to each other and to one of the second ports (26), the second networks (RT, R2') being capable of being supplied with gas by said second ports (26) independently of each other.

4. De-icing system (10) according to any one of the preceding claims, wherein the first cells (18) each have a generally elongated shape and extend parallel to each other, and wherein the second cells (22) each have a generally elongated shape and extend parallel to each other.

5. Defrosting system (10) according to claim 4, wherein the first cells (18) extend parallel to the second cells (22).

6. Defrosting system (10) according to any one of the preceding claims, wherein the number of first cells (18) is identical to the number of second cells (22).

7. Defrosting system (10) according to the preceding claim, wherein the second cells (22) are housed respectively in the first cells (18) so that each of the first cells (18) includes one of the second cells (22).

8. Defrosting system (10) according to any one of the preceding claims, wherein the first cells (18) are separated from the second cells by a single sub-layer

9. De-icing system (10) according to any one of claims 1 to 8, wherein the first and second connecting lines (L1, L2, ..., Ln) are formed by stitching.

10. De-icing system (10) according to any one of claims 1 to 8, wherein the first and second connecting lines (LT, L2', Ln') are formed by welding.

11. Defrosting system (10) according to any one of claims 8 to 10, wherein the sub-layers (38, 36) or superpositions of sub-layers which form the second cells (18, 22) are made of thermoplastic.

12. De-icing system (10) according to any one of the preceding claims, wherein the first and second ports (24, 26) are at least partly perpendicular to the support layer (12).

13. Aircraft, equipped with at least one de-icing system according to one of the preceding claims.

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