Aircraft having system for attaching element to fuselage and having lightning protection screen
By using plates of electrically insulating and thermally insulating materials between the metal accessories of the aircraft and the fuselage, combined with the design of fastening bolts and nuts, forming a buffer layer to prevent current or heat transfer, the accessories fastening cost in the prior art is solved. The problems of high and poor insulation effect achieve cost-effective electrical and thermal insulation effects.
Patent Information
- Application Number
- CN202410870602.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-29
- Filing Date
- 2024-07-01
- Publication Date
- 2024-12-31
AI Technical Summary
The prior art is difficult to effectively reduce costs when tightening the metal accessories of the aircraft to the outside of the fuselage, while ensuring electrical and thermal insulation. Especially when lightning strikes or sleds are heated, it is easy to cause current or heat to be transferred to the machine. body, causing damage.
Using a plate with electrically insulating and thermally insulating materials, the plate is sandwiched between the body and the metal fittings by fastening bolts and nuts, forming a buffer layer to prevent the transfer of current or heat, and further isolate the bolts from the body through the intermediate plate. to ensure that the interference does not directly contact the fuselage.
It effectively reduces the cost of tightening metal accessories to the outside of the aircraft fuselage, while achieving electrical and thermal insulation, protecting the fuselage from damage from current or heat, and reducing damage during forced landing.
Smart Images
Figure CN119218404A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an aircraft having an attachment system with fittings for fastening an element such as a tube or a skid to the fuselage of the aircraft. Background Art
[0002] An aircraft usually has a fuselage to which two wings are fastened and each wing supports at least one engine, in particular a jet engine. At the central part of the fuselage, the fuselage is covered by a belly fairing.
[0003] Some elements are fastened to the outside of the fuselage, such as the air ducts that run along the fuselage between the fuselage and the belly fairing. It may happen that one of these ducts is partly outside the belly fairing and then in contact with an external element such as the engine, and if lightning strikes the engine, an induced current can flow through this duct.
[0004] In order to prevent the current from propagating to the fuselage, or even into the fuselage, fastening the tube to the fuselage requires the use of specific materials that can be relatively expensive.
[0005] It is therefore necessary to define an arrangement that makes it possible to reduce the costs required to fasten accessories, in particular metal accessories, to the outside of the fuselage, while ensuring electrical insulation.
[0006] Likewise, in order to reduce damage to the fuselage during an emergency landing, for example without landing gear, skids are provided that are fixed to the outside of the fuselage and then slide on the apron. This sliding generates heat in the skids, and it is therefore desirable to prevent this heat from being transferred to the fuselage and its interior. To avoid this heat, specific and expensive materials are used.
[0007] It is therefore necessary to define an arrangement that makes it possible to reduce the costs required for fastening fittings, in particular metal fittings, to the outside of the fuselage, while ensuring thermal insulation.
[0008] Generally, it is necessary to find an arrangement that makes it possible to limit the passage of disturbances such as electric currents or heat flows towards the fuselage. Summary of the invention
[0009] The object of the present invention is to propose an aircraft having an attachment system with metal fittings for fastening an element to the outside of the fuselage of the aircraft.
[0010] To this end, an aircraft is proposed, which has a fuselage, an element and at least one attachment system for fastening the element to the outside of the fuselage, the attachment system having:
[0011] - a panel having a first face and a second face oriented towards the fuselage, wherein the panel is fastened to said fuselage;
[0012] a metal fitting fastened to the element and having a shoe seat having a contact surface portion in contact with the first surface portion; and
[0013] - at least one fastening bolt having a screw and a nut, wherein the head of the screw is received in the plate on one side of the second face portion, and wherein the nut is screwed onto the screw, sandwiching the plate and the shoe seat of the fitting.
[0014] With this attachment system, it is possible to limit the passage of disturbances such as electric current or heat flow towards the fuselage by incorporating buffer plates.
[0015] Advantageously, the plate consists of an electrically insulating material, arranged to prevent the passage of electric current.
[0016] Advantageously, the plate consists of a thermally insulating material, arranged to prevent the passage of heat.
[0017] Advantageously, the attachment system has an intermediate panel arranged against the second face of the panel and intended to be arranged against the fuselage.
[0018] Advantageously, the intermediate plate consists of the same material as the material constituting the plates.
[0019] Advantageously, the plate is fastened to the fuselage by bolts, wherein each bolt has a screw with a head and a nut, the plate having, for each bolt, a through-thru perforation and the fuselage having a through-thru orifice aligned with the perforation, the screw of said bolt passing through the perforation and the associated orifice so as to clamp the plate and the fuselage between the head of the screw of said bolt and the nut of said bolt, and the perforations of the plate are arranged so as not to cause contact between the shoe and the head of the screw.
[0020] Advantageously, the plate is wider than the shoe seat and the perforations are located outside the shoe seat and at a distance therefrom. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The above and other features of the present invention will become more apparent upon reading the following description of an exemplary embodiment given with reference to the accompanying drawings, in which:
[0022] Figure 1 is a side view of an aircraft according to the present invention;
[0023] Figure 2 is along Figure 1 A partial cross-sectional view of the bottom portion of the fuselage of the aircraft taken along line II-II;
[0024] Figure 3 is a perspective view of a specific installation of the attachment system according to the present invention;
[0025] Figure 4 is a top view of an attachment system according to the present invention;
[0026] Figure 5 is an attachment system according to a first embodiment of the present invention. Figure 4 A cross-sectional view along the midline V-V; and
[0027] Figure 6 is an attachment system according to a second embodiment of the present invention. Figure 4 Sectional view along the midline VV. DETAILED DESCRIPTION
[0028] In the following description, position-related terms are considered relative to an aircraft in a forward motion position, i.e., Figure 1 As shown, wherein arrow F shows the direction of forward movement.
[0029] Figure 1 An aircraft 100 is shown, with wings 106 fixed to both sides of a fuselage 101 , each wing carrying at least one engine 102 , in particular a jet engine, in this case carried by means of an engine pylon 104 .
[0030] In the following description, and by convention, the X direction is the longitudinal direction of the aircraft 100, which is oriented positively along the direction of the forward motion of the aircraft 100; the Y direction is the lateral direction of the aircraft 100, which is horizontal when the aircraft 100 is on the ground; and the Z direction is the vertical direction or vertical height when the aircraft 100 is on the ground; these three directions X, Y and Z are orthogonal to each other.
[0031] Figure 2 A cross-sectional view along a vertical plane is shown of the fuselage 101. In the central part of the fuselage 101, the aircraft 100 has a belly fairing 202 which is integral with the fuselage 101 and is on the outside of the fuselage so as to define between them a space 204 in which at least one element 206 of the aircraft 100 is arranged. The belly fairing 202 makes it possible to protect the element 206 from direct lightning strikes.
[0032] In the embodiment of the invention presented here, element 206 is a tube, such as an air tube supplying, for example, engine 102, but it can also be another element. For example, element 206 can be a skid, intended to ensure that, for example, aircraft 100 slides on the apron when landing without landing gear.
[0033] The element 206 is fastened to the fuselage 101 by at least one fitting 208 which is integral with the fuselage 101. Figure 2In the embodiment of the invention shown, the element 206 has, in this case, a rod 210 fastened to a fitting 208 .
[0034] Figure 3 Shown with Figure 2 The same elements, but without the belly fairing 202 .
[0035] Figure 4 1 shows an attachment system 300 according to a first embodiment of the present invention, Figure 5 A cross-sectional view of the attachment system 300 is shown.
[0036] The fitting 208 in this case takes the form of a female clamping piece in which the element 206 is fastened in this case by means of a rod 210. The fitting 208 in this case has a shoe 209 which in this case is a flat wall allowing the fitting 208 to be fastened to the fuselage 101 using fastening bolts 304 described below.
[0037] The attachment system 300 has the fitting 208 and the plate 302 .
[0038] The plate 302 has a first face 302a and a second face 302b. The second face 302b faces the fuselage 101 and is oriented on the outside of the fuselage 101.
[0039] The panel 302 is fastened to the fuselage 101 by any suitable fastening means, such as threaded fasteners, rivets, welds, etc.
[0040] In the embodiment of the invention proposed here, the plate 302 is fastened to the fuselage 101 by means of a plurality of bolts 306, wherein each bolt has a screw 306a with a head and a nut 306b. To this end, the plate 302 has a through-going perforation 303 and the fuselage 101 has an orifice 305, which is also a through-going orifice positioned in alignment with the perforation 303 when the plate 302 is pressed against the fuselage 101. For each bolt 306, the screw 306a of said bolt 306 passes through the perforation 303 and the associated orifice 305 and the plate 302 and the fuselage 101 are thus clamped between the head of said screw 306a and the nut 306b of said bolt 306. Figure 5 In the embodiment of the invention shown, the head of each screw 306a is a countersunk head which is inserted into a countersunk hole of the plate 302 on the side of the first face 302a, and the nut 306b bears against the fuselage 101. The bolt 306 does not pass through the fitting 208.
[0041] In order to prevent the passage of electric current or heat between the shoe seat 209 and the bolt 306, the through hole 303 in the plate 302 is arranged so that there is no contact between the shoe seat 209a and the head of the screw 306a in the assembled position. In the embodiment of the invention proposed here, the plate 302 is wider than the shoe seat 209, and the through hole 303 is outside the shoe seat 209 and at a certain distance from the shoe seat 209.
[0042] The shoe seat 209 of the accessory 208 has a contact surface portion 208a that contacts the first surface portion 302a of the plate 302. Therefore, the plate 302 is located between the accessory 208 and the fuselage 101.
[0043] The attachment system 300 also has at least one fastening bolt 304 , wherein each fastening bolt has a screw 304 a and a nut 304 b .
[0044] For each fastening bolt 304, the plate 302 has a hole 308 passing through the plate 302 on one side of the second face 302b, and in the form shown, the hole 308 is a countersunk hole in this case, in which the head of the screw 304a is accommodated so as to be flush with the second face 302, which thus remains flat.
[0045] Each nut 304b is screwed to the associated screw 304a, sandwiching the plate 302 and the fitting 208. Each nut 304b thus abuts against the bearing surface 208b, which is the surface of the shoe seat 209 opposite to the contact surface 208a.
[0046] With this assembly, the body 101 can be protected from possible disturbances, such as current or heat flow, coming from the element 206 through the fitting 208. The plate 302 thus constitutes a screen, preventing disturbances (current, heat) from reaching the body 101.
[0047] The head of the screw 304a does not pass through the body 101, and it is integrated in the plate 302 so that the head is flush with the second face 302b of the plate 302 and does not extend beyond the second face 302b.
[0048] The screw 304 a and the nut 304 b of the fastening bolt 304 make it possible to fasten the plate 302 to the fitting 208 and therefore to the element 206 without penetrating the fuselage 101 , by means of the screw 306 a and the nut 306 b of the bolt 306 .
[0049] For example, in the case where the element 206 is a skid, the plate 302 is advantageously constructed of a material arranged to limit the passage of heat, so that heating of the skid will result in limited heating of the fuselage 101. This material thus acts as a thermal insulation material, and it may be made of mica, glass fiber reinforced polymer, titanium alloy, carbon fiber reinforced polymer, etc.
[0050] For example, in the case where the element 206 is a tube susceptible to receiving a lightning strike, which may induce a current in the tube and the fitting 208, especially when it is a metal fitting, the plate 302 is advantageously composed of a material arranged to prevent the passage of current, so that the lightning strike does not reach the fuselage 101. This material thus acts as an electrical insulator and it may be made of ABS, glass fiber reinforced polymer, etc.
[0051] Due to the presence of the ventral fairing 202 , a potential lightning strike cannot directly reach the bolt 306 .
[0052] According to one specific embodiment, plate 302 has a minimum resistance of 1 ohm.
[0053] Figure 6 An attachment system 400 according to a second embodiment of the present invention is shown. Figure 4 This also corresponds to the connection system 400 according to the second embodiment of the invention. The same elements as in the first embodiment have the same reference numerals.
[0054] In order to further limit the passage of any electric current between the accessory 208 and the fuselage 101, the attachment system 400 has an intermediate plate 402, which is arranged between the second face 302b of the plate 302 and the fuselage 101, so as to separate the head of the screw 304a of each fastening bolt 304 from the fuselage 101. Therefore, the intermediate plate 402 abuts against the second face 302b of the plate 302 on one side and against the fuselage 101 on the other side.
[0055] For each bolt 306 , the intermediate plate 402 has a through hole 403 into which a screw 306 a of the bolt 306 is introduced.
[0056] Although this second embodiment is more particularly suitable for situations involving induction current, it can also be used in situations involving heat transfer.
[0057] The material constituting the intermediate plate 402 is the same as the material constituting the plate 302, ie, a thermally insulating material or an electrically insulating material, as the case may be.
[0058] exist Figure 5 and Figure 6 In the illustrated embodiment of the present invention, each nut 304b, 306b is covered with a cap 310 made of an electrically insulating material, such as ABS, glass fiber reinforced polymer, or the like.
Claims
1. An aircraft (100) comprising a fuselage (101), an element (206) and at least one attachment system (300, 400) for fastening the element (206) to the outside of the fuselage (101), the attachment system (300, 400) comprising: - a plate (302) having a first face (302a) and a second face (302b) oriented towards the fuselage (101), and wherein, The plate (302) is fastened to the fuselage (101); - a metal fitting (208) fastened to the element (206) and having a shoe seat (209) having a contact surface (208a) in contact with the first surface (302a); and - at least one fastening bolt (304), the at least one fastening bolt having a screw (304a) and a nut (304b), wherein the head of the screw (304a) is received in the plate (302) on one side of the second surface portion (302b), and wherein the nut (304b) is screwed onto the screw (304a) to sandwich the plate (302) and the shoe seat of the accessory (208).
2. The aircraft (100) according to claim 1, characterized in that: The plate (302) comprises an electrically insulating material arranged to prevent the passage of electric current.
3. The aircraft (100) according to claim 1, characterized in that: The plate (302) comprises a thermally insulating material arranged to limit the passage of heat.
4. The aircraft (100) according to claim 1, characterized in that: The aircraft has an intermediate panel (402) arranged against the second face (302b) of the panel (302) and intended to be arranged against the fuselage (101).
5. The aircraft (100) according to claim 4, characterized in that: The intermediate plate (402) comprises the same material as that constituting the plate (302).
6. The aircraft (100) according to claim 1, characterized in that: The plate (302) is fastened to the fuselage (101) by bolts (306), wherein each bolt has a screw (306a) with a head and a nut (306b), wherein for each bolt (306), the plate (302) has a through-going hole (303), and the fuselage (101) has a through-going hole (305) aligned with the through-going hole (303), wherein for each bolt (306), the bolt (306) has a through-going hole (305) aligned with the through-going hole (303), The screw (306a) passes through the through-hole (303) and the associated aperture (305) to clamp the plate (302) and the fuselage (101) between the head of the screw (306a) of the bolt (306) and the nut (306b) of the bolt (306), and wherein the through-hole (303) of the plate (302) is arranged so that there is no contact between the shoe seat (209) and the head of the screw (306a).
7. The aircraft (100) according to claim 6, characterized in that The plate (302) is wider than the shoe seat (209), and the through hole (303) is outside the shoe seat and at a distance from the shoe seat.