A composite leading edge structure of an aircraft vertical tail stabilizer

Abstract

The present invention discloses a composite leading edge structure of an aircraft vertical tail stabilizer in the field of aircraft tail fins, comprising a front skin assembly, wherein a plurality of rib boxes are installed on the inner side of the front skin assembly from the root to the end, wherein the outer surface of the rib boxes has the same shape as the inner surface of the front skin assembly and is bonded together, and the rib boxes are connected via partitions, and the front skin assembly is composed of a honeycomb sandwich layer and a bird-splitting assembly wrapped between an inner skin and an outer skin, and the bird-splitting assembly comprises a first metal cutter, a wedge-shaped composite cutter and a second metal cutter, wherein the first metal cutter is arranged at the root of the leading edge structure, the second metal cutter is arranged at the end of the leading edge structure, and the wedge-shaped composite cutter is arranged between the first metal cutter and the second metal cutter. The present invention solves the problem of weak impact resistance of the rear end of the leading edge of the existing tail fin, greatly enhances the impact resistance of the aircraft vertical tail, reduces weight, and can be used in various types of aircraft.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to an aircraft tail structure. Background Art

[0002] Traditional vertical stabilizer leading edges are typically formed by riveting aluminum alloy skins and aluminum alloy ribs. CCAR Part 25, Section 25.631, requires that the tail structure be designed to ensure the aircraft can continue to fly and land safely after a bird collision weighing 3.6 kg (8 lbs). Due to the properties of metal materials, achieving the required impact resistance can only be achieved by increasing the skin thickness or adding metal ribs at high leading edge airfoil heights and large leading edge impact areas. This results in a heavy metal vertical stabilizer leading edge after assembly. The metal leading edge ribs are co-riveted with the leading edge skin and front beam, making assembly and disassembly difficult. Furthermore, metal structures have poor corrosion resistance, especially for aircraft operating in humid marine environments, where acid, alkali, and salt corrosion are poor. Therefore, using composite materials instead of metal offers many advantages and holds great promise.

[0003] The prior art discloses a tail fin capable of improving the bird strike resistance of an aircraft. Its publication number is CN102390520 A, and its publication date is March 28, 2012. The tail fin comprises a front skin assembly, wherein the front skin assembly comprises a honeycomb core and a bird separator encased between an inner skin and an outer skin. The bird separator is formed by bending an aluminum alloy rectangular plate. A small front beam, wing ribs, and a large front beam are fixed in sequence to the rear end of the front skin assembly, forming a square frame structure. However, the square frame structure has a disadvantage in that, since the middle portion is hollow, the middle portion has no support in the event of an impact, resulting in weak impact resistance. In addition, since the vertical tail fin is wider than the horizontal tail fin, the force-bearing area in the event of a bird strike is also relatively larger. The leading edge structure is blunter than that of the horizontal tail fin, that is, after the horizontal tail fin is decomposed, the impact of the bird's body on the surface is relatively smaller. The widest part of the leading edge of the horizontal tail fin is 300 mm, and the widest part of the leading edge of the vertical tail fin is 450 mm. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a composite leading edge structure for an aircraft vertical tail stabilizer, which solves the problem of weak impact resistance of the existing tail leading edge.

[0005] The object of the present invention is achieved as follows: A composite leading edge structure of an aircraft vertical tail stabilizer includes a front skin assembly, wherein a plurality of rib boxes are installed on the inner side of the front skin assembly from the root to the end, the outer surface of the rib box is the same shape as the inner surface of the front skin assembly and is fitted together, and the rib boxes are connected via partitions, the front skin assembly is composed of a honeycomb sandwich layer and a bird-splitting assembly wrapped between an inner skin and an outer skin, the bird-splitting assembly includes a first metal cutter, a wedge-shaped composite cutter and a second metal cutter, the first metal cutter is arranged at the root of the leading edge structure, the second metal cutter is arranged at the end of the leading edge structure, and the wedge-shaped composite cutter is arranged between the first metal cutter and the second metal cutter.

[0006] Compared with the prior art, the present invention has the following beneficial effects:

[0007] Since the vertical tail is relatively blunt (i.e., the vertical tail is wider than the horizontal tail), a bird strike will inevitably cause a heavier impact on both sides of the leading edge relative to the horizontal tail. The present invention designs a rib box that fits the leading edge at the rear end of the leading edge and adds partitions between the rib boxes. When a bird strikes, if the bird hits the rib box position, the rib box structure can offset the impact force very well. However, from the perspective of weight reduction, it is impossible to install the rib box structure at a high density. When the bird hits the position between the two rib boxes, the impact force can also be offset well due to the design of the partition. The partition connects the two rib boxes and can also enhance the overall impact resistance, and there is no hollow structure. The present invention replaces the original metal structure with a large number of composite structure cutters in the middle, which reduces weight. In addition, the present invention also reduces maintenance costs. The use of composite materials can greatly reduce maintenance costs compared to metal materials.

[0008] As a further improvement to the present invention, the wedge-shaped composite cutter includes a first wedge-shaped bar, a second wedge-shaped bar, and an arc-shaped bar. The first and second wedge-shaped bars are symmetrical and their front ends are bonded together. The rear ends of the first and second wedge-shaped bars are bonded to the ends of the arc-shaped bar, forming a cavity between the first, second, and arc-shaped bars. This structural design results in a sharp front end for the wedge structure, making it easy to disassemble a bird's body. The arc-shaped bar at the rear end has a certain toughness, which can provide a cushioning effect.

[0009] As a further improvement of the present invention, the first metal cutter includes a root arc-shaped connecting portion attached to the inner side of the inner skin. A root wedge-shaped decomposition portion is provided on the surface of the root arc-shaped connecting portion near the root. The root wedge-shaped decomposition portion passes through the root arc-shaped connecting portion, and a connecting end portion is provided on the side of the root arc-shaped connecting portion near the root. This structure enhances the strength of the root portion.

[0010] As a further improvement of the present invention, the second auxiliary cutter includes an end arc-shaped connecting portion, and an end wedge-shaped decomposition portion is provided on the surface of the end arc-shaped connecting portion near the end. Such a structure enhances the strength of the tail portion.

[0011] As a further improvement of the present invention, a connector is fixed to the tail of the rib box, which can be adaptively connected to install structures of different sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0013] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0014] Figure 2 It is a side sectional view of the present invention.

[0015] Figure 3 It is a side view of the present invention.

[0016] Figure 4 For the Figure 3 Middle AA section view.

[0017] Figure 5 For the Figure 3 Middle BB section view.

[0018] Figure 6 For the Figure 3 Center CC section view.

[0019] Figure 7 This is an end view of the wedge-shaped composite cutter structure in the present invention.

[0020] Figure 8 This is a schematic structural diagram of the first metal cutter in the present invention.

[0021] Figure 9 This is a schematic structural diagram of the second metal cutter in the present invention.

[0022] Figure 10 This is a schematic diagram of the connection between the rib box and the partition in the present invention.

[0023] Figure 11 This is a structural schematic diagram of the present invention installed on a vertical tail.

[0024] Figure 12 Impact test for the present invention Figure 1 .

[0025] Figure 13 Impact test for the present invention Figure 2 .

[0026] Figure 14 Impact test for the present invention Figure 3 .

[0027] Among them, 1 front skin assembly, 101 inner skin, 102 outer skin, 103 honeycomb sandwich, 104 bird-shaped assembly, 104a first metal cutter, 104aa root arc connection part, 104ab root wedge-shaped decomposition part, 104b wedge-shaped composite cutter, 104ba first wedge-shaped strip, 104bb second wedge-shaped strip, 104bc rear arc strip, 104c second metal cutter, 104ca end arc connection part, 104cb end wedge-shaped decomposition part, 2 rib boxes, 3 partitions, 4 connectors, 5 vertical tail, 6 leading edge structure. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] like Figure 1-11 The composite leading edge structure of a vertical tail stabilizer of an aircraft is shown, which is installed at the front end of a vertical tail 5. The leading edge structure 6 includes a front skin assembly 1. Nine rib boxes 2 are installed on the inner side of the front skin assembly 1 from the root to the end. The outer surface of the rib box 2 has the same shape as the inner surface of the front skin assembly 1 and fits together. The rib box 2 and the solid area of the front skin assembly 1 are riveted together by pins. The rib boxes 2 are connected by partitions 3. The partitions 3 can be honeycomb sandwich partitions 3. The tail of the rib box 2 is fixed with a connector 4, which has a folded plate structure.

[0030] The front skin assembly 1 is composed of a honeycomb sandwich 103 and a bird-cutting assembly 104 wrapped between the inner skin 101 and the outer skin 102. The thickness of the inner skin 101 is 0.6 mm, the thickness of the outer skin 102 is 1 mm, the honeycomb sandwich 103 is a variable thickness structure, the thickest part is 52 mm, and the thinnest part is 18 mm. The bird-cutting assembly 104 includes a first metal cutter 104a, a wedge-shaped composite cutter 104b and a second metal cutter 104c. The first metal cutter 104a is arranged at the root of the leading edge structure, attached to the inner side of the inner skin 101, and connected to the inner skin 101 and the wedge-shaped composite cutter 104b by means of pins. The second metal cutter 104c is arranged at the end of the leading edge structure, attached to the inner side of the inner skin 101, and connected to the inner skin 101 and the wedge-shaped composite cutter 104b by means of pins. The wedge-shaped composite cutter 104b is arranged between the first metal cutter 104a and the second metal cutter 104c, and is formed by pulling through from the root to the end.

[0031] The wedge-shaped composite material cutter 104b includes a first wedge-shaped strip 104ba (the upper part in the figure), a second wedge-shaped strip 104bb (the lower part in the figure) and an arc-shaped strip (the rear part in the figure). The three are connected by adhesive film curing. The first wedge-shaped strip 104ba and the second wedge-shaped strip 104bb are symmetrical to each other, and the front ends are attached together. The rear ends of the first wedge-shaped strip 104ba and the second wedge-shaped strip 104bb are attached to the two ends of the arc-shaped strip. The first wedge-shaped strip 104ba includes a front wedge-shaped portion, a middle support portion and a rear wedge-shaped portion. The front wedge-shaped strip An obtuse angle is formed between the first wedge strip 104ba and the middle supporting portion, the front wedge-shaped portion of the first wedge strip 104ba is fitted together with the inner side of the front wedge-shaped portion of the second wedge strip 104bb, the arc-shaped strip is fitted together with the rear wedge-shaped portion of the first wedge strip 104ba and the rear wedge-shaped portion of the second wedge strip 104bb, and a cavity is formed between the first wedge strip 104ba, the second wedge strip 104bb and the arc-shaped strip, and the cavity can be filled with foam glue.

[0032] The first metal cutter 104a comprises a root arc-shaped connecting portion 104aa (connected using pull-out pins) attached to the inner side of the inner skin. A root wedge-shaped decomposition portion 104ab is provided near the root of the root arc-shaped connecting portion 104aa, and a connecting end portion is provided on the side of the root arc-shaped connecting portion 104aa near the root. The second auxiliary cutter 104c comprises an end arc-shaped connecting portion 104ca, and an end wedge-shaped decomposition portion 104cb is provided near the end of the end arc-shaped connecting portion 104ca. This structure enhances the strength of the tail section.

[0033] The present invention designs a rib box 2 that fits the leading edge at the rear end of the leading edge, and adds a partition 3 between the rib boxes 2. When a bird hits, if the impact hits the rib box 2, the rib box 2 structure can offset the impact force well. If the impact hits the position between the two rib boxes 2, the impact force can also be offset well due to the design of the partition 3. The partition 3 connects the two rib boxes 2, thereby enhancing the overall impact resistance. The metal reinforcement is replaced with the bird separation component 104 of the above structure, especially the wedge-shaped composite cutter 104b, which greatly reduces the weight. At the same time, this special structure of the composite cutter can decompose the bird body well and has a certain toughness, which greatly enhances the impact resistance of the leading edge. Under the premise of ensuring the impact resistance, the weight is reduced.

[0034] The characteristics of the bird separation component 104 structure are described as follows:

[0035] The front wedge-shaped portion of the first wedge-shaped strip 104ba and the front wedge-shaped portion of the second wedge-shaped strip 104bb are fitted together to form a dividing portion. This portion is relatively sharp and can directly decompose the bird's body when encountering a bird collision. The structure here is different from the hollow tip structure inside the triangle. As a solid triangular structure, it has a stronger impact resistance when encountering a bird collision; the middle support portion is the main force-bearing portion. With the cooperation of the obtuse angle, it can withstand a large amount of impact force earlier when a bird hits, thereby ensuring the overall strength of the bird separator. Therefore, its thickness cannot be adjusted. The wedge-shaped structure at the rear end is designed based on the consideration that when the force is transmitted from the front end to the rear end, the main receiving area is close to the inner side of the wedge-shaped strip. Therefore, considering the weight reduction design, the outer side can reduce the material for wedge surface treatment; in addition, the wedge strip formed by the obtuse angle structure is more stressed than the triangular plane structure. The area is larger; the design of the rear arc strip 104bc structure forms an elastic force-bearing area, that is, when the impact force of the front end is transmitted to the rear, the middle support part and the rear wedge-shaped part will undergo slight elastic deformation and reset after the external force is eliminated, which has a good buffering effect. Compared with the metal plane structure, it has better toughness; the two ends of the wedge-shaped composite cutter 104b need to be fixed to play the role of separating birds. Due to structural design reasons, the root and end ribs cannot fix the wedge-shaped composite cutter 104b. The first metal cutter 104a and the second metal cutter 104c can play the role of the wedge-shaped composite cutter 104b. At the same time, the wedge-shaped composite cutter 104b is mainly supported by the honeycomb. The honeycomb cannot penetrate the entire leading edge, so the root and end cutters continue and strengthen the role of the wedge structure in separating birds.

[0036] like Figure 12-14 As shown in FIG. 1 , the bird strike test result of the present invention is performed. The test condition requires a 3.6 kg (8 lb) bird to collide at a speed of ≈520 km / h. As can be seen from the figure, the damaged part is only the honeycomb interlayer 103, the inner skin 101 is not damaged, and the front beam is not penetrated, thus meeting the design requirements.

[0037] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A composite leading edge structure of an aircraft vertical tail stabilizer, comprising a front skin assembly (1), characterized in that: A plurality of rib boxes (2) are installed on the inner side of the front skin assembly (1) from the root to the end. The outer surface of the rib box (2) has the same shape as the inner surface of the front skin assembly (1) and is bonded together. The rib boxes (2) are connected via a partition (3). The front skin assembly (1) is composed of a honeycomb sandwich (103) wrapped between the inner skin (101) and the outer skin (102) and a bird separation assembly (104). The bird separation assembly (104) includes a first metal cutter (104a), a wedge-shaped composite material cutter (104b) and a second metal cutter (104c). The first metal cutter (104a) is arranged at the root of the leading edge structure, the second metal cutter (104c) is arranged at the end of the leading edge structure, and the wedge-shaped composite material cutter (104b) is arranged between the first metal cutter (104a) and the second metal cutter (104c). The wedge-shaped composite material cutter (104b) is arranged between the first metal cutter (104a) and the second metal cutter (104c). 04b) includes a first wedge-shaped strip (104ba), a second wedge-shaped strip (104bb) and an arc-shaped strip, wherein the first wedge-shaped strip (104ba) and the second wedge-shaped strip (104bb) are symmetrical to each other and the front ends thereof are attached together, and the rear ends of the first wedge-shaped strip (104ba) and the second wedge-shaped strip (104bb) are attached to the two ends of the arc-shaped strip, and the first wedge-shaped strip (104ba), the second wedge-shaped strip (104bb) and the arc-shaped strip are formed between the three. The first wedge-shaped strip (104ba) includes a front wedge-shaped portion, a middle support portion, and a rear wedge-shaped portion. An obtuse angle is formed between the front wedge-shaped portion and the middle support portion. The front wedge-shaped portion of the first wedge-shaped strip (104ba) is bonded to the inner side of the front wedge-shaped portion of the second wedge-shaped strip (104bb). The arc strip (104bc) is bonded to the rear wedge-shaped portion of the first wedge-shaped strip (104ba) and the rear wedge-shaped portion of the second wedge-shaped strip (104bb). The first metal cutter (104a) comprises a root arc-shaped connecting portion (104aa) attached to the inner side of the inner skin (101), a root wedge-shaped decomposition portion (104ab) is provided on the surface of the root arc-shaped connecting portion (104aa) near the root position, and a connecting end is provided on the side of the root arc-shaped connecting portion (104aa) near the root position; The second metal cutter (104c) comprises an end arc-shaped connecting portion (104ca), and an end wedge-shaped decomposition portion (104cb) is provided on the surface of the end arc-shaped connecting portion (104ca) near the end.

2. The composite leading edge structure of an aircraft vertical tail stabilizer according to claim 1, characterized in that: A connecting piece (4) is fixed to the tail of the rib box (2).

Images