System for detecting local overheating of a thrust reverser, particularly of an aircraft

Abstract

System (20) for detecting local overheating of equipment (8), in particular of an aircraft, covered by at least one thermal protection panel (10). The system (20) for detecting local overheating comprises at least one safety member (22) mounted between equipment (8) and the thermal protection panel (10), the safety member (22) comprising at least one thermally configured fuse element to switch from a first initial state to a second state when the temperature of the equipment (8) exceeds a threshold value. Figure for abstract: [Fig 3]

Description

Title of the invention: System for detecting local overheating of a thrust reverser, in particular of an aircraft Technical field of the invention

[0001] The present invention relates to the field of detecting local overheating of aircraft equipment, in particular a thrust reverser. State of the prior art

[0002] Local overheating of aircraft equipment damages the structure of the nacelle components despite the thermal protection of the equipment.

[0003] In order to avoid such overheating, it is known to equip the aircraft with thermal protections in order to protect and insulate the aircraft equipment to keep them at acceptable temperatures and thus extend their service life.

[0004] In this regard, reference may be made to document WO2017 / 220931 which describes an assembly of fixed structure of a turbojet nacelle and thermal protection panels mounted on the internal face of the fixed structure of the nacelle.

[0005] Currently, only the dismantling of the thermal protection equipment and visual examination allows local overheating to be identified, by analyzing the coloring and surface appearance of the component.

[0006] However, such a visual examination is not sufficiently reliable to avoid the rejection of a significant number of aircraft parts. In addition, it is possible, during the visual examination, not to identify local overheating and especially not to know the temperature level seen by the component and therefore to judge its structural deterioration in order to decide on the action to be taken for its repair.

[0007] Thus, there is a need to improve the detection of local overheating of aircraft equipment in order to know the temperature level seen by the equipment. Presentation of the invention

[0008] The present invention therefore aims to overcome the aforementioned drawbacks and to propose reliable detection of local overheating of aircraft equipment.

[0009] The present invention therefore aims to propose a simple and inexpensive detection of aircraft equipment, in particular the nacelle, with regard to its exposure to high temperatures in order to avoid unnecessary scrap.

[0010] The invention therefore relates to a system for detecting local overheating of a thrust reverser of a nacelle of an aircraft comprising an internal fixed structure and at least one thermal protection panel fixed to the internal surface of the internal fixed structure.

[0011] The system for detecting local overheating of a thrust reverser comprises at least one safety member mounted between said internal fixed structure and the thermal protection panel.

[0012] The safety member comprises at least one thermally fusible element configured to switch from a first initial state to a second state when the temperature of the equipment exceeds a threshold value.

[0013] Such a system for detecting local overheating is reliable, space-saving, installable on existing machines and does not call into question the certification of the equipment in service.

[0014] Advantageously, the safety member of the local overheating detection system has a generally annular shape comprising an annular external envelope surrounding the thermally fusible element.

[0015] For example, the annular outer envelope is made of insulating material.

[0016] According to one embodiment, the safety member of the local overheating detection system comprises a number greater than or equal to two of thermally fusible elements, for example equal to eight.

[0017] According to one embodiment, the thermally fusible elements of the local overheating detection system are calibrated to different temperature threshold values ​​to move from the first initial state to the second state.

[0018] Thus, we can know all the temperatures experienced by the equipment.

[0019] For example, the thermally fusible elements are regularly angularly spaced.

[0020] According to one embodiment, each of the thermally fusible elements of the local overheating detection system comprises a first end connected to a positive pole of a conductive blade, for example made of copper, and a second end, opposite the first end, connected to a negative pole of a conductive bar or wire, for example made of copper, each thermally fusible element associated with the conductive blade and the conductive bar forming an electrical circuit.

[0021] For example, the safety member is arranged in a housing of the thermal protection panel and accessible via a through hole made in said panel so that the conductive bar is centered in the through hole of the thermal protection.

[0022] For example, the thermally fusible elements extend radially in the outer casing.

[0023] According to one embodiment, the thermally fusible elements are made from a conductive material configured to melt when the temperature exceeds the corresponding temperature threshold value.

[0024] Alternatively, the thermally fusible elements could be made of a material configured to change color, such as for example a thermal pad, or to change shape or rupture when the temperature exceeds said threshold value. In this case, the change of state of a thermally fusible element can be detected visually, which however requires the disassembly of the thermal protection.

[0025] According to one embodiment, the system for detecting local overheating comprises a member for detecting the change in state of the thermally fusible elements configured to cooperate with the safety member in an overheating detection position in order to control the thermally fusible element(s).

[0026] For example, the state change detection member comprises at least one light means, for example a diode, associated with a thermally fusible element and configured to change from an off state to an on state in the overheating detection position, a conductive tip connected to the light means and in contact with the conductive bar and the conductive blade of the safety member in the overheating detection position and an electrical power supply member, such as for example a battery, configured to supply electricity to the light means and the electrical circuit of the safety member.

[0027] The number of light means is equal to the number of thermally fusible elements.

[0028] In the overheating detection position, the conductive tip is inserted into the through hole of the thermal protection until it comes into contact with the safety member and in particular the conductive blades and the conductive wire.

[0029] Thus, when an electrical circuit of the safety device is broken, following overheating, the light means do not change from the off state to an on state in the detection position.

[0030] According to another embodiment, the system for detecting local overheating comprises a plurality of safety devices.

[0031] Indeed, in the case where a large number of safety devices are installed, the detection of overheating could take longer.

[0032] For example, the thermal protection panel delimits at least two local overheating detection zones, each local overheating detection zone comprising one or more safety members each mounted radially between the internal surface of the internal fixed structure and the corresponding thermal protection panel.

[0033] Advantageously, each of the safety members of each local overheating detection zone comprises a main thermally fusible element, said main thermally fusible element of each of the members being connected in series. by two cables, one end of which is connected to a box located off the protection panels.

[0034] The main thermally fusible element of each of the safety members to be connected preferably corresponds to the thermally fusible element configured to pass from a first initial state before any possible overheating to a second state after overheating when the temperature exceeds a minimum threshold value lower than the threshold values ​​of the other thermally fusible elements of each local overheating detection zone.

[0035] Thus, the main thermally fusible element of each of the safety members to be connected is made from a conductive material configured to melt when the temperature exceeds the minimum threshold value. In other words, it is this main fusible element which will melt first, which will break the electrical connection of the cables to the housing and thus allow the detection of local overheating. the change of state of a thermally fusible main element is then electrically detected with a change of state detection member in the detection position.

[0036] The state change detection member is, for example, a voltmeter configured to detect or not detect a current at the terminals of the housing corresponding to each of the local overheating detection zones.

[0037] According to another aspect, the invention relates to a method for detecting local overheating of a thrust reverser of a nacelle of an aircraft comprising an internal fixed structure and at least one thermal protection panel fixed on the internal surface of the internal fixed structure.

[0038] According to the method, local overheating is detected using a system for detecting local overheating of the internal fixed structure comprising at least one safety member mounted between said internal fixed structure and the thermal protection panel, the safety member of the detection system comprising at least one thermally fusible element configured to pass from a first initial state to a second state when the temperature of the equipment exceeds a threshold value, local overheating being detected when the thermally fusible element passes from the first initial state to the second state.

[0039] For example, local overheating is detected visually,

[0040] According to another embodiment, local overheating is detected using a member for detecting the change of state of the thermally fusible elements configured to cooperate with the safety member in an overheating detection position.

[0041] According to another aspect, the invention relates to a thrust reverser comprising an internal fixed structure and at least one thermal protection panel fixed on the internal surface of the internal fixed structure. The thrust reverser includes a system for detecting local overheating of the internal fixed structure as described above.

[0042] According to another aspect, the invention relates to an aircraft comprising a thrust reverser as described above. Brief description of the drawings

[0043] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the indexed drawings in which:

[0044] [Fig.l] schematically illustrates a perspective view of an aircraft propulsion system;

[0045] [Fig.2] is a perspective view in section of a rear section of the nacelle of [Fig.l] comprising a system for detecting local overheating according to an embodiment of the invention;

[0046] [Fig.3] is a sectional view of the rear section of [Fig.2];

[0047] [Fig.4] is a perspective view of a safety device of the local overheating detection system of [Fig.2];

[0048] [Fig.5] is a detailed view of the local overheating detection system of [Fig.2];

[0049] [Fig.6] is a detailed view of a detection member of the local overheating detection system of [Fig.2];

[0050] [Fig.7] is a perspective view in section of a rear section of the nacelle of [Fig.l] comprising a system for detecting local overheating according to another embodiment of the invention; and

[0051] [Fig.8] is a detailed view of the local overheating detection system of [Fig.7]. Detailed description of at least one embodiment

[0052] In the remainder of the description, the terms “upstream” and “downstream” are defined in relation to the direction of air circulation in the turbomachine.

[0053] In [Fig.l] is shown very schematically an aircraft propulsion unit 1 comprising a nacelle 2 radially surrounding a turbojet (not shown).

[0054] The nacelle 2 extends along a longitudinal axis XX and generally has a tubular structure comprising an air inlet 3 upstream of the turbojet engine, a middle section 4 intended to surround a fan of the turbojet engine, a downstream section 5 which can house thrust reverser means (not shown) and intended to surround the combustion chamber of the turbojet engine.

[0055] The downstream section 5 corresponds to a thrust reverser of the nacelle 2.

[0056] The nacelle 2 is generally terminated by an ejection nozzle 6 whose outlet is located downstream of the turbojet.

[0057] As illustrated in [Fig.2], the downstream section 5 or thrust reverser comprises an external fixed structure 7, called "Outer fixed structure", acronym "OFS" in English terms and an internal fixed structure 8, called "Inner fixed structure", acronym IFS in English terms. The external fixed structure 7 defines with the internal fixed structure 8, a secondary vein 9 configured to channel the air flow or secondary flow coming from the fan and circulating outside the turbojet.

[0058] The nacelle 2 further comprises a plurality of thermal protection panels 10 fixed to the internal surface 8a of the internal fixed structure 8. The fixing of the thermal protection panels 10 is known and will not be described further.

[0059] The nacelle 2 further comprises a system 20 for detecting local overheating of the internal fixed structure 8. However, the system 20 for detecting local overheating can be used to detect local overheating of all parts of the nacelle, or even of all the equipment of the aircraft. The use of the system 20 for detecting local overheating is not limited to use in the aeronautical field and could be used in all vehicles, as well as in all equipment which undergoes a strong increase in heat.

[0060] The system 20 for detecting local overheating, here of the internal fixed structure 8, comprises a safety member 22 mounted radially between the internal surface 8a of the internal fixed structure 8 and a thermal protection panel 10.

[0061] The safety member 22 is arranged in a housing 10a of the thermal protection panel 10 and accessible via a through hole 10b made in the thickness of the panel 10 and opening both into the housing 10a and onto the external surface 10c of the protection panel.

[0062] As illustrated in detail in [Fig.4], the safety member 22 has a generally annular shape and comprises an annular outer casing 24, a plurality of thermally fusible elements 26 each configured to pass from a first initial state before any possible overheating to a second state after overheating when the temperature exceeds a threshold value.

[0063] The annular outer casing 24 is made of insulating material.

[0064] The thermally fusible elements 26 extend radially from the outer casing 24 towards the center of the safety member 22.

[0065] As illustrated, the thermally fusible elements 26 are regularly angularly spaced.

[0066] Each of the thermally fusible elements 26 comprises a first end 26a connected to a positive pole P+ of a conductive blade 27, for example made of copper. Each of the thermally fusible elements 26 comprises a second end 26b, opposite the first end 26a, connected to a negative pole P- of a conductive bar or wire 28, for example made of copper.

[0067] Each thermally fusible element 26 associated with the conductive blade 27 and the conductive wire 28 forms an electrical circuit.

[0068] The safety member 22 is mounted in the housing 10a so that the conductive wire 28 is centered in the through hole 10b of the thermal protection 10.

[0069] As illustrated, there are eight thermally fusible elements 26. Alternatively, a different number of thermally fusible elements 26 could be provided, for example a single thermally fusible element, greater than or equal to two, or even greater than eight.

[0070] The thermally fusible elements 26 are, for example, made from a conductive material configured to melt when the temperature exceeds a threshold value.

[0071] The thermally fusible elements 26 here have the role of opening a corresponding electrical circuit when the temperature exceeds said threshold value.

[0072] Alternatively, the thermally fusible elements 26 could be made of a material configured to change color, such as for example a thermal pad, or to change shape or rupture when the temperature exceeds said threshold value.

[0073] Generally, the thermally fusible elements 26 are each configured to pass from a first initial state before any possible overheating to a second state after overheating.

[0074] The thermally fusible elements 26 may be calibrated at different temperature threshold values ​​to transition from the first initial state to the second state.

[0075] Thus, we can know all of the temperatures experienced by the aircraft equipment, here the internal fixed structure 8.

[0076] The change of state of a thermally fusible element 26 can be detected visually, which however requires the dismantling of the thermal protection 10.

[0077] Alternatively, the change of state of a thermally fusible element 26 can be detected electrically with a member 30 for detecting the change of state visible in detail in FIGS. 5 and 6.

[0078] The member 30 for detecting the change of state comprises a cylindrical body 32 in which are housed a plurality of light means 34, for example diodes, visible on the external surface 32a of the body 32.

[0079] The member 30 for detecting the change of state further comprises a conductive tip 36 extending radially from the cylindrical body 32 towards the safety member 22 in an overheating detection position and an electrical power supply member 38, such as a battery, visible in [Fig. 6], configured to supply electricity to the light means 34 and the electrical circuits of the safety member 22.

[0080] In the overheating detection position, the conductive tip 36 is inserted into the through hole 10b of the thermal protection 10 until it comes into contact with the safety member 22 and in particular the conductive blades 27 and the conductive wire 28.

[0081] Thus, the member 30 for detecting the change of state is an external device configured to be inserted into the through hole 10b of the thermal protection 10 in order to control each of the thermally fusible elements 26.

[0082] Each of the light means 34 is configured to switch from an off state to an on state in the overheating detection position.

[0083] Thus, when an electrical circuit of the safety member 22 is broken, following overheating, the light means 34 do not change from the off state to an on state in the detection position.

[0084] It is therefore possible to visually observe the change of state of the light means 34 on the member 30 for detecting the change of state without dismantling the thermal protection 10.

[0085] The control consists of checking either visually or electrically with the state change detection member 30 comprising a battery and light means if the electrical circuit is broken.

[0086] The embodiment illustrated in Figures 7 and 8, in which the same elements bear the same references, differs from the embodiment illustrated in [Fig.2], only by the fact that the system 20' for detecting local overheating comprises a plurality of safety members 22.

[0087] Indeed, in the case where a large number of safety devices 22 are installed, the detection of overheating could take longer.

[0088] As illustrated in [Fig.7], the thermal protection panel 10 delimits three zones A, B, C for detecting local overheating. Each zone A, B, C for detecting local overheating comprises one or more safety members 22 each mounted radially between the internal surface 8a of the internal fixed structure 8 and the thermal protection panel 10.

[0089] In a manner identical to the embodiment illustrated in [Fig.2], each safety member 22 is arranged in a housing 10a, visible in [Fig.3], of the thermal protection panel 10 and accessible via a through hole 10b, visible in [Fig.3], made in the thickness of the panel 10 and opening both into the housing 10a and onto the external surface 10c, visible in [Fig.3], of the protection panel.

[0090] As illustrated in detail in [Fig.8], the main thermally fusible elements 26 of each of the safety members 22 of each zone A, B, C for detecting local overheating are connected in series by two cables, respectively 41, 42; 43, 44; 45, 46, one end of which is connected to a housing 40 remote from the protection panels 10.

[0091] The main thermally fusible element 26 of each of the safety members 22 to be connected corresponds to the thermally fusible element 26 configured to pass from a first initial state before any possible overheating to a second state after overheating when the temperature exceeds a minimum threshold value lower than the threshold values ​​of the other thermally fusible elements 26 of each zone A, B, C for detecting local overheating.

[0092] Thus, the main thermally fusible element 26 of each of the safety members 22 to be connected is made from a conductive material configured to melt when the temperature exceeds the minimum threshold value. In other words, it is this main fusible element which will melt first, which will break the electrical connection of the cables 41, 42; 43, 44; 45, 46 to the housing 40 and thus allow the detection of local overheating.

[0093] The change of state of a main thermally fusible element 26 is then detected electrically with a member (not visible in [Fig.8]) for detecting the change of state.

[0094] The state change detection member is, for example, a voltmeter configured to detect or not a current at the terminals of the housing 40 corresponding to each of the zones A, B, C for detecting local overheating.

[0095] The state change detection device is known and will not be described further.

[0096] Thus, the state change detection member is an external device, remote from the protection panels 10, capable of controlling each of the zones A, B, C for detecting local overheating.

[0097] Thanks to the local overheating detection system, it is possible to obtain reliable and precise information on the temperatures experienced by a given piece of equipment.

[0098] Such a system for detecting local overheating is reliable, space-saving, installable on existing machines and does not call into question the certification of the equipment in service.

[0099] Such a system for detecting local overheating can be mounted on all elements of the nacelle and equipment of the aircraft which may be subjected to high temperatures capable of damaging the structure and the resistance of the elements of the aircraft.

[0100] Generally speaking, such a system for detecting local overheating can be mounted on all equipment that may be subjected to high temperatures.

Claims

Claims

1. System (20) for detecting local overheating of a thrust reverser (5) of a nacelle (2) of an aircraft comprising an internal fixed structure (8) and at least one thermal protection panel (10) fixed on the internal surface (8a) of the internal fixed structure (8), characterized in that it comprises at least one safety member (22) mounted between said internal fixed structure (8) and the thermal protection panel (10), the safety member (22) being arranged in a housing (10a) of the thermal protection panel (10) and accessible via a through hole (10b) made in the thickness of said panel (10), the safety member (22) comprising at least one thermally fusible element (26) configured to pass from a first initial state to a second state when the temperature of the internal fixed structure (8) exceeds a threshold value,the system (20) for detecting local overheating further comprising a member (30) for detecting the change of state of the thermally fusible elements (26) configured to be inserted into the through hole (10b) of the thermal protection (10) and to cooperate with the safety member (22) in an overheating detection position, the member (30) for detecting the change of state comprising at least one luminous means (34) associated with a thermally fusible element and configured to change from an off state to an on state in the overheating detection position,a conductive tip (36) connected to the light means (34) extending radially towards the safety member (22) in an overheating detection position and an electrical supply member (38) configured to supply electricity to the light means (34) and the electrical circuit of the safety member (22) and in which the conductive tip (36) is in contact with a conductive bar (28) and a conductive blade (27) of the safety member (22) in the overheating detection position, the conductive tip (36) extending from a cylindrical body (32) towards the safety member (22), the cylindrical body housing the light means (34).,

2. A system for detecting local overheating of a thrust reverser (5) according to claim 1, wherein the system (20) for detecting local overheating comprises a number greater than or equal to two of thermally fusible elements (26) and in wherein the thermally fusible elements (26) of the local overheating detection system (20) are calibrated to different temperature threshold values ​​to transition from the first initial state to the second state.

3. A system for detecting local overheating of a thrust reverser (5) according to any one of the preceding claims, wherein each of the thermally fusible elements (26) of the system (20) for detecting local overheating comprises a first end (26a) connected to a positive pole (P+) of the conductive blade (27) and a second end (26b), opposite the first end (26a), connected to a negative pole (P-) of the conductive bar (28), each thermally fusible element (26) associated with the conductive blade (27) and the conductive bar (28) forming an electrical circuit.

4. System for detecting local overheating of a thrust reverser (5) according to any one of the preceding claims, in which the system (20) for detecting local overheating comprises a plurality of safety members (22).

5. System for detecting local overheating of a thrust reverser (5) according to claim 4, in which the thermal protection panel (10) delimits at least two zones (A, B, C) for detecting local overheating, each zone (A, B, C) for detecting local overheating comprising one or more safety members (22) each mounted radially between the internal surface (8a) of the internal fixed structure (8) and the corresponding thermal protection panel (10).

6. Method for detecting local overheating of a thrust reverser (5) of a nacelle (2) of an aircraft comprising an internal fixed structure (8) and at least one thermal protection panel (10) fixed to the internal surface (8a) of the internal fixed structure (8), in which local overheating is detected using a system (20) for detecting local overheating of the internal fixed structure (8) comprising at least one safety member (22) mounted between said internal fixed structure (8) and the thermal protection panel (10), the safety member (22) being arranged in a housing (10a) of the thermal protection panel (10) and accessible via a through hole (10b) made in the thickness of said panel (10), the safety member (22) comprising at least one element (26)

7. thermally fuse configured to switch from a first initial state to a second state when the temperature of the internal fixed structure (8) exceeds a threshold value, the system (20) for detecting local overheating further comprising configured to be inserted into the through hole (10b) of the thermal protection (10) and to cooperate with the safety member (22) in an overheating detection position, a member (30) for detecting the change of state of the thermally fusible elements (26), at least one luminous means (34) associated with a thermally fusible element (26) and configured to switch from an off state to an on state in the overheating detection position,a conductive tip (36) connected to the light means and extending radially towards the safety member (22) in an overheating detection position and an electrical supply member (38) configured to supply electricity to the light means (34) and the electrical circuits of the safety member (22), the conductive tip (36) being in contact with a conductive bar (28) and a conductive blade (27) of the safety member (22) in the overheating detection position, the conductive tip (36) extending from a cylindrical body (32) towards the safety member (22), the cylindrical body housing the light means (34), in which, in the overheating detection position, the member (30) for detecting the change of state of the thermally fusible elements (26) is inserted into the through hole (10b) of the thermal protection (10) until contact with the safety member (22),local overheating being detected when the thermally fusible element (26) passes from the first initial state to the second state and the luminous means of the member (30) for detecting the change of state of the thermally fusible elements (26) passes from an off state to an on state., Thrust reverser (5) comprising an internal fixed structure (8) and at least one thermal protection panel (10) fixed on the internal surface (8a) of the internal fixed structure (8), the panel (10) comprising a housing (10a) accessible via a through hole (10b) made in the thickness of said panel (10), said thrust reverser (5) comprising a system (20) for detecting local overheating of the internal fixed structure (8) according to one of the following:

8. any of claims 1 to 5 arranged in the housing (10a) of the thermal protection panel (10). Aircraft comprising a thrust reverser (5) according to claim 7.

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