Composite material maintenance covering cap of wing fuel tank

Abstract

The utility model discloses a composite material maintenance covering cap of a wing fuel tank and belongs to the technical field of wing covering caps. The weight of the fuel tank covering cap assembly can be effectively reduced, meanwhile, the weight of the wings is reduced, the electrochemical corrosion problem caused by a single aluminum alloy metal covering cap is avoided, sufficient overall rigidity is provided, the requirement for oil pressure of a fuel tank is met, meanwhile, the requirements for collision prevention, lightning protection, fire resistance, sealing and the like are met, manufacturing and dismounting are convenient, and the sealing requirement of the covering cap is met; and the manufacturing and maintenance cost is low. An oil tank opening cover opening hole is formed in the wing lower wall plate, the inner opening cover and the outer opening cover are oppositely arranged inside and outside and are fixedly clamped and installed in the oil tank opening cover opening hole of the wing lower wall plate through bolts, and a tooth-shaped sealing ring is arranged between the inner opening cover and the outer opening cover. According to the utility model, the base body has insulativity, so that external lightning current cannot enter an oil tank to generate point discharge.

Description

Technical Field

[0001] The utility model belongs to the technical field of wing covers, and in particular relates to a composite material maintenance cover for a wing oil tank. Background Art

[0002] The wings of large aircraft are usually used as the aircraft's fuel tanks, which are equipped with a complex fuel system and its accompanying pipelines. They require frequent maintenance, so multiple fuel tank maintenance covers are designed on the lower wall panels of the aircraft's wings.

[0003] Traditional aircraft wing covers often use pressure ring type aluminum alloy covers, which are mainly composed of an inner cover and a pressure ring. The cover and the pressure ring are made of aluminum alloy. The cover is machined. There is a reinforcing rib in the middle of the cover. The pressure ring is connected to the cover by screws to form a certain clamping force with the lower wall panel. The sealing ring is set on the connecting side between the outside of the cover and the inside of the lower wall panel to meet the sealing requirements of the cover.

[0004] With the development of technology, composite wings have been increasingly used in aircraft structures in recent years. They have the advantages of reducing the weight of aircraft and extending the life of aircraft. Based on the existing technology, the use of existing single-layer metal covers and the main structure of wing composite materials has the risk of galvanic corrosion. At the same time, the single-layer cover must not only withstand the oil pressure load of the wing, but also meet the requirements of anti-collision, lightning protection, fire resistance, and sealing. If the maintenance cover of the composite wing is designed and manufactured with a pressure ring aluminum alloy cover, the protection is difficult and the structure is heavy.

[0005] Therefore, there is an urgent need for a fuel tank maintenance cover suitable for composite wings that can meet the requirements of light weight, low cost, easy maintenance, collision protection, lightning protection, fire resistance, sealing, etc. required for cooperation with composite wings, and solve the problem of electrochemical corrosion of aluminum alloy metal covers. Utility Model Content

[0006] In order to solve the above-mentioned problems, the utility model further provides a composite material maintenance cover for a wing fuel tank, which ensures the realization of the cover function, can effectively reduce the weight of the fuel tank cover assembly, and at the same time reduces the weight of the wing, avoids the electrochemical corrosion problem caused by a single aluminum alloy metal cover, provides sufficient overall rigidity, ensures the fuel tank oil pressure requirement, and at the same time, meets the requirements of anti-collision, lightning protection, fire resistance, sealing, etc., is easy to manufacture and disassemble, ensures the sealing requirements of the cover, and has low manufacturing and maintenance costs.

[0007] The technical solution adopted by the utility model is:

[0008] A composite material maintenance cover for a wing oil tank comprises a wing lower wall panel, an inner cover, an outer cover, a toothed sealing ring and bolts; the wing lower wall panel is provided with an oil tank cover opening, the inner cover and the outer cover are arranged opposite to each other inside and outside and are fixedly clamped and installed in the oil tank cover opening of the wing lower wall panel by bolts, and a toothed sealing ring is arranged between the inner cover and the outer cover.

[0009] Compared with the prior art, the utility model has the following beneficial effects:

[0010] 1. The utility model can effectively reduce the weight of the fuel tank cover assembly, while reducing the weight of the wing, avoiding the electrochemical corrosion problem caused by a single aluminum alloy metal cover, providing sufficient overall rigidity, ensuring the fuel tank oil pressure requirements, and ensuring the sealing requirements and detachable requirements of the cover.

[0011] 2. The utility model has matrix insulation, which ensures that external lightning current cannot enter the oil tank and produce tip discharge.

[0012] 3. The front panel and the inner panel of the utility model are designed with mutually supporting oblong depressions, which can improve the rigidity of the panel and reduce the weight of the structure.

[0013] 4. The utility model uses adhesive film to prepare a sandwich structure outer cover by hot molding or autoclave technology, which has sufficient panel stiffness and strength to meet the requirements of impact resistance and fire resistance of the cover and provide support for the inner panel. The outer panel surface of the outer cover is paved with a lightning protection copper mesh to ensure that the lightning current can be effectively transmitted to the wing wall panels around the opening, avoiding the lightning current from entering the interior of the fuel tank and affecting the safety of the fuel tank.

[0014] 5. The injection-molded screw sleeve sealing cap of the utility model is embedded with a self-locking screw sleeve, which ensures that the self-locking screw sleeve is embedded in the inside of the cover, and the fastener does not enter the oil tank area, avoiding the metal bolts and nuts being exposed in the oil tank to generate tip discharge, thereby improving the lightning protection safety of the rib oil tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the lower wing wall panel of the utility model;

[0016] Figure 2 This is a schematic axonometric diagram of the installation of the isolation adjustment washer of the utility model;

[0017] Figure 3 This is a schematic front view of the installation of the isolation adjustment washer of the utility model;

[0018] Figure 4 This is the installation diagram of the isolation adjustment washer of the utility model;

[0019] Figure 5 This is a schematic diagram of the structure of the inner cover of the utility model;

[0020] Figure 6 It is a schematic diagram of the panel structure of the inner cover of the utility model;

[0021] Figure 7 It is a schematic diagram of the composition of the inner cover of the utility model;

[0022] Figure 8 This is a main sectional view of the inner cover of the utility model;

[0023] Fig. 9 This is a schematic diagram of the structure of the outer cover of the utility model;

[0024] Fig.10 This is a main sectional view of the outer cover of the utility model;

[0025] Fig.11 This is an assembly diagram of the toothed seal ring and the inner cover of the utility model;

[0026] Fig.12 This is a cross-sectional view of the toothed seal ring and the inner cover of the utility model;

[0027] Fig.13 This is the installation diagram of the mouth cover assembly of the utility model;

[0028] Fig.14 This is an assembly diagram of the lower wing panel cover of the utility model;

[0029] Fig.15 This is the assembly drawing of the lower wing wall panel of the utility model;

[0030] Among them: 1. Wing lower wall panel; 2. Inner cover; 3. Outer cover; 4. Toothed sealing ring; 5. Isolation adjustment gasket; 6. Isolation bushing; 7. Bolt; 101. Fuel tank cover opening; 201. Panel; 202. Self-locking screw sleeve; 203. Screw sleeve sealing cap; 301. Inner panel; 302. Outer panel; 303. Honeycomb core. DETAILED DESCRIPTION

[0031] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0032] like Figure 1 to Figure 15 As shown, the utility model provides a composite material maintenance cover for a wing fuel tank, comprising a wing lower wall panel 1, an inner cover 2, an outer cover 3, a toothed sealing ring 4 and a bolt 7; the wing lower wall panel 1 is provided with a fuel tank cover opening 101, the inner cover 2 and the outer cover 3 are arranged opposite to each other inside and outside and fixedly clamped and installed in the fuel tank cover opening 101 of the wing lower wall panel 1 by bolts 7, and a toothed sealing ring 4 is arranged between the inner cover 2 and the outer cover 3.

[0033] The wing lower wall panel 1 is provided with an inserted layer or a machined sunken area at the lower wall panel cover to ensure that the outer cover 3 fits well with the wing lower wall panel 1 and avoids protrusion of the outer cover 3, thereby effectively improving the aerodynamic efficiency of the wing; at the same time, the inner side of the area is designed as a flat structural surface, providing a flat installation area for the composite material inner cover 2 to ensure the sealing of the cover.

[0034] like Figure 2 to Figure 4 As shown, in order to protect the composite wing panel and reduce the wear of the composite wing panel, an isolation adjustment gasket 5 is provided. The isolation adjustment gasket 5 is made of nylon or thermoplastic glass fiber reinforced material, is made by hot pressing or injection molding, and is installed on the inner side of the tank cover opening 101 of the wing lower panel 1 through the tank sealant; the isolation adjustment gasket 5 plays an insulating isolation role and solves the wear problem of the composite material cover.

[0035] The isolation adjustment gasket 5 can be designed to have different thicknesses to match the different wall panel thicknesses in the wing span direction, and play a role in thickness adaptation and gap adjustment to ensure the versatility of the fuel tank cover assembly, reduce manufacturing costs, reduce assembly difficulty, and avoid the risk of misinstallation of covers of different configurations.

[0036] like Figure 3 As shown, the edge of the isolation adjustment gasket 5 is set to a basin-shaped structure with a small angle warping, which can effectively reduce the adverse effect of fuel sloshing on the cover seal.

[0037] like Figures 5 to 8 As shown, the inner port cover 2 includes a panel 201, a plurality of self-locking screw sleeves 202 and a plurality of screw sleeve sealing caps 203; a plurality of bolt holes are circumferentially formed on the panel 201 for port cover installation. The screw sleeve sealing caps 203 are injection molded at the corresponding positions of the bolt holes on the surface of the panel 201, and the self-locking screw sleeves 202 are embedded in the injection molded screw sleeve sealing caps 203 to ensure that the self-locking screw sleeves 202 are embedded in the port cover, and the fasteners do not enter the fuel tank area, so as to avoid the metal bolts and nuts being exposed in the fuel tank to generate tip discharge, thereby improving the lightning protection safety of the rib fuel tank.

[0038] like Figure 6 As shown, the panel 201 is made of nylon or thermoplastic carbon fiber reinforced material, which can be prepared by hot molding or autoclave processes, and has matrix insulation to ensure that external lightning current cannot enter the fuel tank and produce tip discharge; at the same time, carbon fiber has weak conductivity, which can transmit the static electricity of the fuel tank in real time to avoid static electricity accumulation; the panel 201 is provided with an oblong depression to improve the rigidity of the panel, and under the support of the outer mouth cover 3, the oil pressure requirement of the fuel tank is guaranteed, which can reduce the weight of the structure. At the same time, the edge of the panel 201 is provided with an annular depression to provide installation space for the toothed sealing ring 4, and the cross-sectional size of the annular depression is adapted to the toothed sealing ring 4 to ensure the sealing of the mouth cover;

[0039] like Fig.11 , Fig.12As shown, the toothed sealing ring 4 can be an O, M type silicone rubber sealing strip or a straight sealing strip made of polytetrafluoroethylene material, embedded in the inner cover 2 to play a sealing role.

[0040] like Fig. 9 , Fig.10 As shown, the outer cover 3 is a combined sandwich structure cover, including an inner panel 301, an outer panel 302 and a honeycomb core 303; the combined outer cover has functions such as fire resistance and impact resistance, which ensures the impact resistance and lightning protection requirements of the fuel tank cover, and supports and protects the composite material inner cover 2, increasing the overall rigidity of the fuel tank cover. The honeycomb core 303 is arranged between the inner panel 301 and the outer panel 302 to form a sandwich structure.

[0041] The inner panel 301, the outer panel 302, and the honeycomb core 303 are made of adhesive film by hot molding or autoclave to prepare the outer cover 3 of the sandwich structure, which has sufficient panel rigidity and strength to meet the requirements of the cover for impact resistance and fire resistance, and provide support for the panel 201;

[0042] The surface of the outer panel 302 is paved with a lightning protection copper mesh to ensure that the lightning current can be effectively transmitted to the wing wall panels around the opening, thereby preventing the lightning current from entering the interior of the fuel tank and affecting the safety of the fuel tank.

[0043] like Fig.10 As shown, after the outer cover 3 of the combined sandwich structure is completed, the edge of the outer cover 3 is machined to form an edge bevel that matches the inserted layer or machined sunken area of ​​the wing lower wall panel 1, ensuring that the outer cover 3 fits the wing lower wall panel 1 and avoids the cover protruding, thereby effectively improving the aerodynamic efficiency of the wing; annular bolt holes that match the inner cover 2 are made by numerical control or according to a drilling template.

[0044] The oil tank sealant is continuously applied in the annular pressure groove at the edge of the panel 201, and the toothed sealing ring 4 is embedded. The annular pressure groove at the edge of the panel 201 provides installation space for the toothed sealing ring 4, and finally the connecting bolts of the inner and outer covers are tightened to ensure the oil tank seal;

[0045] Each bolt hole on the outer cover 3 is embedded with an isolation bushing 6, and the isolation bushing 6 is made of non-metallic insulating materials such as nylon or thermoplastic, and is manufactured by injection molding or machining.

[0046] When the cover is installed, the bolt 7 passes through the isolation bushing 6 embedded in the outer cover 3 and is connected to the self-locking screw sleeve 202 in the screw sleeve sealing cap 203 of the inner cover 2. It is ensured that the edge of the outer cover 3 matches the bevel edge of the wing lower wall panel 1 to meet the aerodynamic surface assembly requirements; tightening the bolt 7 forms a certain clamping force between the inner cover 2 and the outer cover 3, ensuring that the inner cover 2 and the isolation adjustment gasket 5 form a complete seal through the toothed sealing ring 4, ensuring that the tank cover is tightly assembled with the wing lower wall panel 1, providing a non-load-bearing cover solution to meet the functional requirements of the cover.

[0047] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A composite material maintenance cover for a wing fuel tank, characterized in that: The invention comprises a wing lower wall panel (1), an inner cover (2), an outer cover (3), a toothed sealing ring (4) and bolts (7); the wing lower wall panel (1) is provided with a fuel tank cover opening (101); the inner cover (2) and the outer cover (3) are arranged opposite to each other inside and outside and are fixedly clamped and installed in the fuel tank cover opening (101) of the wing lower wall panel (1) by bolts (7); and a toothed sealing ring (4) is arranged between the inner cover (2) and the outer cover (3).

2. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The composite material maintenance cover of the wing fuel tank also includes an isolation adjustment gasket (5), which is made of nylon or thermoplastic glass fiber reinforced material through a hot pressing or injection molding process and is installed on the inner side of the fuel tank cover opening (101) of the wing lower wall panel (1) through a fuel tank sealant.

3. The composite material maintenance cover for a wing fuel tank according to claim 2, characterized in that: The edge of the isolation adjustment gasket (5) is arranged to be a basin-shaped structure with a small angle warping.

4. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The inner cover (2) comprises a panel (201), a plurality of self-locking screw sleeves (202) and a plurality of screw sleeve sealing caps (203); a plurality of bolt holes are circumferentially formed on the panel (201), screw sleeve sealing caps (203) are injection-molded at positions corresponding to the bolt holes on the surface of the panel (201), and the self-locking screw sleeves (202) are embedded in the injection-molded screw sleeve sealing caps (203).

5. The composite material maintenance cover for a wing fuel tank according to claim 4, characterized in that: The panel (201) is made of nylon or thermoplastic carbon fiber reinforced material and has matrix insulation properties. An oblong depression is provided on the panel (201), and an annular depression is provided on the edge of the panel (201) to provide installation space for the toothed sealing ring (4).

6. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The outer cover (3) comprises an inner panel (301), an outer panel (302) and a honeycomb core (303); the honeycomb core (303) is arranged between the inner panel (301) and the outer panel (302) to form a sandwich structure; the inner panel (301), the outer panel (302) and the honeycomb core (303) are prepared into a sandwich structure by using adhesive film through hot molding or autoclave technology; and the surface of the outer panel (302) is paved with a lightning protection copper mesh.

7. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The edge of the outer cover (3) is machined to form an edge bevel that matches the inserted layer or machined sunken area of ​​the wing lower wall panel (1), thereby ensuring that the outer cover (3) fits the wing lower wall panel (1).

8. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The outer cover (3) is provided with a plurality of bolt holes corresponding to the annular bolt holes on the panel (201), and each bolt hole of the outer cover (3) is embedded with an isolation bushing (6), wherein the isolation bushing (6) is made of nylon or thermoplastic non-metallic insulating material and is manufactured by injection molding or machining.

9. The composite material maintenance cover for a wing fuel tank according to claim 1, characterized in that: The wing lower wall panel (1) is provided with an insert layer or a machined sunken area at the lower wall panel opening cover to ensure that the outer opening cover (3) fits the wing lower wall panel (1).

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