A frameless and beamless T-tail aircraft vertical tail wing tip fairing

Abstract

The utility model discloses a kind of frameless beam T-shaped tail wing airplane vertical tail wing tip fairing cover. Including the front cover (1) connected in order from front to back along the direction of flight, middle cover subassembly and rear cover subassembly, the top of middle, rear cover subassembly is the top cover (2) of integrated type, top cover (2) leading edge is connected with the rear edge of front cover (1), the two side walls of rear cover subassembly are equipped with rear side cover (3), the upper edge of two rear side cover (3) is respectively connected with the two side edge of top cover (2), the leading edge of rear side cover (3) is connected with the rear edge of front cover (1) by middle cover lower skin (4), top cover (2) and middle cover lower skin (4) are equipped with flat tail through-hole (5) between, the bottom edge between two rear side cover (3) is respectively connected with cap-shaped piece (6) and bottom cover (7) from front to back along the direction of flight. The utility model is not prone to the fatigue problem of connection area generated by vibration of rear cover structure.

Description

Technical Field

[0001] This utility model belongs to the field of aircraft structural design technology, specifically relating to a frameless and beamless T-tail aircraft vertical tail fin tip fairing. Background Technology

[0002] The fin-tip fairing, located at the highest point of a T-tail aircraft, significantly impacts the weight and center of gravity of large T-tail aircraft, directly determining their performance. The lightweight and high-strength characteristics of carbon fiber composites have inevitably made their application in fin-tip fairing structures a trend. However, the fin-tip fairing structure is highly susceptible to aircraft vibration, making it prone to fatigue failure such as cracks in the connection areas and component detachment. The detachment of the fin-tip fairing can further damage load-bearing structural components such as the rudder located below the fairing, potentially leading to serious flight accidents.

[0003] Patent CN117302505A proposes a T-tail aircraft with an all-composite material vertical tail fin tip dome. Although it has significant effects on weight reduction and structural simplification, this structure still has the following drawbacks: 1) The entire rear cover section is only connected to the middle cover assembly through thin frame sections II and III. Under long-term vibration, fatigue problems may occur in the connection area between the rear cover section and the middle cover, or even the entire rear cover section may fall off. 2) The load transmission route of the rear cover section is not direct. The inertial load generated by the entire rear cover section can almost all be transmitted from the rear edge rib to the tail beam, and the connection between the rear edge rib and the tail beam is relatively weak. 3) The overall structure of the vertical tail fin tip has a large number of skin segments and connecting frames (18 in total), which does not fully utilize the advantages of the composite material integral molding technology. 4) The fairing uses a variety of assembly processes (metal fasteners and adhesive connectors). While adhesive connectors have a certain advantage in weight, the workload for their assembly and related airworthiness certification is much greater. Utility Model Content

[0004] The purpose of this invention is to provide a frameless, beamless T-tail aircraft vertical tail fin tip fairing. This invention is less prone to fastener fatigue problems in the connection area caused by vibration in the rear fairing structure.

[0005] The technical solution of this utility model is: a frameless and beamless T-tail aircraft vertical tail wingtip fairing, including a front fairing, a middle fairing assembly and a rear fairing assembly connected sequentially from front to back along the flight direction. The top of the middle and rear fairing assemblies is an integral top fairing, and the front edge of the top fairing is connected to the rear edge of the front fairing. Both side walls of the rear fairing assembly are provided with rear side fairings. The upper edges of the two rear side fairings are respectively connected to the two side edges of the top fairing. The front edge of the rear side fairing is connected to the rear edge of the front fairing through the lower skin of the middle fairing. A horizontal tail through hole is provided between the top fairing and the lower skin of the middle fairing. A cap-shaped piece and a bottom fairing are respectively connected from front to back along the flight direction between the bottom edges of the two rear side fairings.

[0006] In the aforementioned frameless and beamless T-tail aircraft vertical tail wingtip fairing, the top fairing is a sandwich panel structure. The plane perpendicular to the heading and past the leading edge of the rear side fairing serves as the interface between the middle and rear fairing components. The two plane intervals formed after moving 100mm forward and backward from the interface have a core material height of 10mm for the top fairing sandwich panel, and the height gradually transitions to 5mm at both ends of the interval.

[0007] In the aforementioned frameless, beamless T-tail aircraft vertical tail fin tip fairing, the transition surface I at both ends of the section forms a 20° angle with the outer surface of the top fairing. In the aforementioned frameless and beamless T-tail aircraft vertical tail wingtip fairing, the sandwich panel ply of the two planar sections is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel ply of the sections after gradually transitioning outward to 5mm at both ends is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45].

[0008] In the aforementioned frameless and beamless T-tail aircraft vertical tail wingtip fairing, the rear fairing is also a sandwich panel structure. The rearward 20mm from the leading edge of the rear fairing is a reinforcement area with a core material height of 10mm. The core material height gradually transitions to 5mm towards the rear of the reinforcement area.

[0009] In the aforementioned frameless and beamless T-tail aircraft vertical tail fin tip fairing, the angle between the transition surface where the height of the core material in the reinforcement area gradually transitions to 5mm and the outer surface of the rear side fairing is 20°.

[0010] In the aforementioned frameless and beamless T-tail aircraft vertical tail wingtip fairing, the sandwich panel ply in the reinforcing area is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel ply after the core material height gradually transitions to 5mm in the reinforcing area is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45].

[0011] In the aforementioned frameless and beamless T-tail aircraft vertical tail fin tip fairing, the leading edge of the top fairing is connected to the trailing edge of the front fairing via a bracket nut.

[0012] In the aforementioned frameless and beamless T-tail aircraft vertical tail fin tip fairing, connecting corner boxes are provided at the side where the leading edge of the top fairing connects to the trailing edge of the front fairing, and at the connection between the upper edge of the side fairing and the side edge of the top fairing.

[0013] In the aforementioned frameless and beamless T-tail aircraft, the wingtip fairing of the vertical tail is an integral structure of the cap-shaped component and the bottom cover.

[0014] The technical effects of this utility model are as follows: The fairing connection structure of this utility model can achieve the following while maintaining the perfect appearance of the fairing: 1) The load transmission route is direct, and it is not easy to cause fatigue problems in the connection area caused by vibration of the rear fairing structure; 2) The assembly process of the vertical tail fin tip fairing is unique, avoiding the additional workload of subsequent airworthiness certification; 3) The vertical tail fin tip fairing connection process is simple, frameless and beamless, and easier to assemble; 4) The rear fairing section of the vertical tail fin tip fairing can also be disassembled and assembled as a whole; 5) The vertical tail fin tip fairing is lighter and has a shorter manufacturing cycle. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an exploded view of the structural component of this utility model; Figure 3 This is a schematic diagram of the cross-sectional structure of the top cover sandwich panel. Detailed Implementation

[0016] To make the implementation process of this utility model clearer, the technical solutions of this utility model will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model, and the parts not detailed are conventional techniques. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0017] Example 1. A T-tail aircraft's all-composite material vertical tail fin tip cover, see [reference needed]. Figures 1-3The system comprises a front cover 1, a middle cover assembly, and a rear cover assembly connected sequentially from front to back along the flight direction. The top of the middle and rear cover assemblies is a single-piece top cover 2, with the front edge of the top cover 2 connected to the rear edge of the front cover 1. Both sides of the rear cover assembly are provided with rear side covers 3, the upper edges of which are connected to the side edges of the top cover 2 respectively. The front edge of the rear side covers 3 is connected to the rear edge of the front cover 1 via the lower skin 4 of the middle cover. A horizontal tail through-hole 5 is provided between the top cover 2 and the lower skin 4 of the middle cover. A cap-shaped component 6 and a bottom cover 7 are connected sequentially from front to back along the flight direction between the bottom edges of the two rear side covers 3. The single-piece top cover 2 avoids the problem of the rear cover assembly accounting for a large portion of the overall structural weight and being susceptible to vibration.

[0018] The aforementioned top cover 2 is a sandwich panel structure. The plane perpendicular to the flight direction and past the front edge of the rear side cover 3 serves as the interface between the middle and rear cover components. The two plane intervals are formed after moving 100mm in front of and behind the interface. The core material height of the sandwich panel of the top cover 2 is 10mm, and the two ends of the interval gradually transition to 5mm outward.

[0019] The transition surfaces at both ends of the aforementioned section form a 20° angle with the outer surface of the top cover 2 to facilitate the processing of the core material and the forming of the overall sandwich structure. The sandwich panel layup for the aforementioned two-planar sections is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel layup after gradually transitioning outwards to 5mm at both ends of the section is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45]. The shear strength of the two-planar sections is increased by increasing the core material height, and the bending resistance is improved by using more 0-degree layups.

[0020] The aforementioned rear cover 3 is also a sandwich panel structure. The front edge of the rear cover 3 extends 20mm backward to form a reinforcement zone. The core material height of the reinforcement zone is 10mm, and the core material height gradually transitions to 5mm towards the rear.

[0021] The aforementioned reinforcing area gradually transitions to a 5mm transition surface with a 20° angle between the transition surface and the outer surface of the rear cover 3, so as to facilitate the processing of the core material and the forming of the overall sandwich structure.

[0022] The sandwich panel layup in the aforementioned reinforcing zone is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel layup after the core material height gradually transitions to 5mm in the rearward direction of the reinforcing zone is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45]. This structure effectively improves the structural rigidity at the connection between the rear side cover 3 and the lower skin of the middle cover 4.

[0023] The front edge of the aforementioned top cover 2 is connected to the rear edge of the front cover 1 by a support plate nut.

[0024] Connecting corner boxes are provided at the side where the front edge of the top cover 2 connects to the rear edge of the front cover 1, and at the connection between the upper edge of the side cover 3 and the side edge of the top cover 2.

[0025] The aforementioned cap-shaped component 6 and bottom cover 7 are integrated into one piece.

[0026] Regarding the connection method, the connection between the top cover 2 and the front cover 1 adopts a detachable support plate nut type. The connection area of ​​the top cover is partially recessed, and a support plate nut is installed on the inner side of the connection area. The bolt is connected in the front cover. The connection between the top cover and the horizontal tail rectifier side strip around the horizontal tail through hole 5 adopts a detachable support plate nut type. The support plate nut is placed on the side of the horizontal tail rectifier side strip.

[0027] In addition, connecting corner boxes are provided on both sides of the connection area between the top cover 2 and the front cover 1, and in the connection area between the top cover 2 and the rear cover 3, to improve the connection strength between the top cover, the front cover, and the rear cover.

[0028] The force path of the entire fairing is as follows: the bottom edge of the front fairing 1 is connected to the leading edge rib 8, the top fairing 2 bears the gravity from the rear fairing assembly, and the gravity is converted into shear force and bending moment, which is transmitted to the trailing edge rib 9 and then to the tail boom. The entire circumferential part of the rear fairing assembly resists the loads generated under various flight conditions through the connection of the connecting corner box and the trailing edge rib 9.

[0029] This structural design features a simple connection method, is less prone to vibration fatigue in the rear cover assembly, has fewer skin segments (only 6 in the rear cover section), is lightweight, has a short manufacturing cycle, and is easy to assemble.

[0030] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A frameless, beamless T-tail aircraft vertical tail fin tip fairing, characterized in that, It includes a front cover (1), a middle cover assembly and a rear cover assembly connected sequentially from front to back along the flight direction. The top of the middle and rear cover assemblies is an integral top cover (2). The front edge of the top cover (2) is connected to the rear edge of the front cover (1). The two side walls of the rear cover assembly are provided with rear side covers (3). The upper edges of the two rear side covers (3) are connected to the two side edges of the top cover (2) respectively. The front edge of the rear side cover (3) is connected to the rear edge of the front cover (1) through the lower skin of the middle cover (4). A flat tail through hole (5) is provided between the top cover (2) and the lower skin of the middle cover (4). The bottom edges of the two rear side covers (3) are connected from front to back along the flight direction with a hat-shaped piece (6) and a bottom cover (7).

2. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 1, characterized in that, The top cover (2) is a sandwich panel structure. The plane perpendicular to the flight direction and past the front edge of the rear side cover (3) is used as the interface between the middle and rear cover components. The two plane intervals are formed after moving 100mm in front of and behind the interface. The core material height of the sandwich panel of the top cover (2) is 10mm, and the two ends of the interval gradually transition to 5mm outward.

3. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 2, characterized in that, The transition surfaces at both ends of the interval and the outer surface of the top cover (2) form an angle of 20°.

4. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 2, characterized in that, The sandwich panel ply of the two planar sections is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel ply of the sections that gradually transition to 5mm from both ends is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45].

5. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 1, characterized in that, The rear cover (3) is also a sandwich panel structure. The front edge of the rear cover (3) extends 20mm backward to form a reinforcement area. The core material height of the reinforcement area is 10mm, and the core material height gradually transitions to 5mm towards the rear.

6. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 5, characterized in that, The angle between the transition surface of the reinforcement area, which gradually transitions to 5mm in height towards the rear core material, and the outer surface of the rear cover (3) is 20°.

7. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 5, characterized in that, The sandwich panel ply in the reinforced area is [45 / 0 / 0 / -45 / 0 / 0 / core material 10mm / 0 / 0 / -45 / 0 / 0 / 45]; the sandwich panel ply after the core material height gradually transitions to 5mm in the reinforced area is [45 / 0 / -45 / 0 / 0 / core material 5mm / 0 / 0 / -45 / 0 / 45].

8. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 1, characterized in that, The front edge of the top cover (2) is connected to the rear edge of the front cover (1) by a support plate nut.

9. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 1, characterized in that, Connecting corner boxes are provided at the side where the front edge of the top cover (2) connects to the rear edge of the front cover (1) and at the connection between the upper edge of the side cover (3) and the side edge of the top cover (2).

10. The frameless, beamless T-tail aircraft vertical tail fin tip fairing according to claim 1, characterized in that, The hat-shaped part (6) and the bottom cover (7) are integrated into one structure.

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