A detachable aircraft fuselage keel joint

Abstract

The utility model discloses a detachable aircraft fuselage keel joint belongs to air space aerospace spare part design technical field, include: upper connecting plate, lower connecting plate, positioning pin subassembly and hydraulic locking mechanism, the upper connecting plate is equipped with the taper positioning hole and the wedge guide groove, the lower connecting plate is equipped with the force sleeve of coaxial with taper positioning hole and the dovetail boss of with guide groove matching, positioning pin subassembly is by taper's head pin shaft and self -lubricating bushing constitutes, the head pin shaft is through positioning hole with force sleeve, hydraulic locking mechanism contains high pressure oil cavity, piston push and locking bolt, the piston push is driven after oil pressure and presses the side of dovetail boss, locking bolt is locked after the piston push. The utility model's keel joint has the advantages such as high positioning accuracy, locking reliable, convenient to dismantle.

Description

Technical Field

[0001] This utility model relates to the field of aerospace component design technology, specifically to a detachable aircraft fuselage keel joint for the docking area between the lower fuselage keel beam and the wing main beam. Background Technology

[0002] In the field of aerospace manufacturing, the aircraft fuselage keel, as a key component bearing the structural load of the fuselage, directly affects the structural safety and service life of the aircraft through the reliability and maintainability of its connection with the wing main spars. Existing aircraft fuselage keel joints generally suffer from the following technical shortcomings:

[0003] 1. Insufficient positioning accuracy: Traditional joints mostly use planar positioning combined with cylindrical pin structure, which is prone to radial displacement when subjected to alternating loads, resulting in the accumulation of assembly errors in the fuselage structure. Under flight vibration, it is prone to displacement, affecting the skin installation accuracy.

[0004] 2. Poor locking reliability: Conventional bolt locking methods rely on manual torque control, which results in uneven preload. They are prone to loosening, especially under high-altitude temperature variations, requiring frequent maintenance.

[0005] 3. Difficult to disassemble and maintain: After long-term use, rigid connection structures are prone to oxidation and corrosion, which can increase disassembly resistance and may also damage the connection surface.

[0006] 4. Weak fatigue resistance: Existing joints have prominent stress concentration problems, especially in the locking part, where fatigue cracks are initiated due to structural design defects.

[0007] 5. High lubrication and maintenance costs: Traditional metal contact surfaces require regular application of grease, but grease is prone to evaporation and failure in high-altitude environments. Summary of the Invention

[0008] In order to overcome the above-mentioned defects of the prior art, this utility model aims to provide a detachable aircraft fuselage keel joint, which solves the problems of low positioning accuracy, unreliable locking, difficult disassembly, poor fatigue resistance and high lubrication and maintenance costs in the prior art through structural innovation.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A detachable aircraft fuselage keel connector includes: an upper connecting plate, a lower connecting plate, a positioning pin assembly, and a hydraulic locking mechanism; the upper connecting plate has a tapered positioning hole and a wedge-shaped guide groove; the lower connecting plate has a load-bearing sleeve coaxial with the tapered positioning hole and a dovetail boss matching the guide groove; the positioning pin assembly consists of a tapered head pin and a self-lubricating bushing, the head pin passing through the positioning hole and the load-bearing sleeve; the hydraulic locking mechanism includes a high-pressure oil chamber, a piston push block, and a locking bolt, the piston push block being driven by oil pressure to press against the side of the dovetail boss, and the locking bolt locking the piston push block after tightening.

[0011] Preferably, the inner end face of the guide groove is provided with a limiting baffle.

[0012] Preferably, the taper angle of the head pin is 5°-8°.

[0013] Preferably, the contact surface between the guide groove and the dovetail boss is provided with micro-serrated anti-slip texture, with a tooth depth of 0.1-0.3mm and a tooth pitch of 2-5mm.

[0014] Preferably, the hydraulic locking mechanism integrates a pressure sensor and a pressure relief safety valve.

[0015] Preferably, the self-lubricating bushing is made of PTFE-bronze composite material with a thickness of 8%-12% of the pin diameter.

[0016] This utility model has the following advantages compared with the prior art:

[0017] 1. Improved positioning accuracy: The tapered positioning hole (tapered 5°-8°) and the load-bearing sleeve form a tapered surface constraint, and the positioning error can be controlled within 0.05mm, which is 4 times more accurate than the traditional cylindrical pin structure, ensuring the consistency of the machine body structure assembly.

[0018] 2. Enhanced locking reliability: The hydraulic locking mechanism drives the piston pusher through oil pressure, generating uniform lateral pressure on the dovetail boss. Tests show that the locking force fluctuation is less than 5% within a temperature range of -50℃ to 120℃, completely solving the problem of bolt loosening.

[0019] 3. Easy disassembly and maintenance: The split design reduces the friction between the wedge-shaped guide groove and the dovetail boss after hydraulic unloading, making maintenance convenient.

[0020] 4. Optimized fatigue resistance: The micro-serrated anti-slip pattern (tooth depth 0.1-0.3mm, tooth pitch 2-5mm) increases the friction of the contact surface by 80%, effectively suppressing fretting wear.

[0021] 5. Reduced lubrication costs: PTFE-bronze composite self-lubricating bushings (thickness of 8%-12% of the pin diameter) achieve maintenance-free lubrication, reducing maintenance costs by 90% compared to traditional lubrication methods.

[0022] 6. Enhanced safety performance: The integrated pressure sensor monitors the oil chamber pressure in real time. When the pressure exceeds the set threshold, the pressure relief safety valve opens automatically to prevent overload damage. The fault warning time is 30% earlier than that of the existing structure. Attached Figure Description

[0023] Figure 1 This is a diagram of the overall structure.

[0024] Figure 2 A front view structural diagram of the lower connecting plate and the hydraulic locking mechanism;

[0025] Figure 3 This is a structural diagram of the lower connecting plate and the hydraulic locking mechanism;

[0026] Figure 4 This is a structural diagram of the upper connecting plate;

[0027] Figure 5 This is a structural diagram of the locating pin assembly.

[0028] In the diagram: 1. Upper connecting plate; 11. Positioning hole; 12. Guide groove; 13. Limiting baffle; 2. Lower connecting plate; 21. Load-bearing sleeve; 22. Dovetail boss; 3. Positioning pin assembly; 31. Head pin; 32. Self-lubricating bushing; 4. Hydraulic locking mechanism; 41. High-pressure oil chamber; 42. Piston push block; 43. Locking bolt; 44. Pressure sensor; 45. Pressure relief safety valve. Detailed Implementation

[0029] The structure and principle of this utility model will now be fully explained with reference to specific embodiments, so that those skilled in the art can fully understand and implement it.

[0030] like Figures 1-5 As shown, this utility model discloses a detachable aircraft fuselage keel connector, comprising: an upper connecting plate 1, a lower connecting plate 2, a positioning pin assembly 3, and a hydraulic locking mechanism 4. The upper connecting plate 1 is fixed to the root flange of the wing main sparsity by high-strength bolts; the lower connecting plate 2 is fixed to the end face of the lower fuselage keel beam by shear bolts; the keel connection is achieved through the fixed connection between the upper connecting plate 1 and the lower connecting plate 2.

[0031] The upper connecting plate 1 is provided with a tapered positioning hole 11 and a wedge-shaped guide groove 12; the lower connecting plate 2 is provided with a load-bearing sleeve 21 (the load-bearing sleeve 21 is a reinforced cylindrical structure integrally formed with the lower connecting plate 2) coaxial with the positioning hole 11 and a dovetail boss 22 matching the guide groove 12; the positioning pin assembly 3 is composed of a tapered head pin 31 (the head is "tapered") and a self-lubricating bushing 32, the head pin 31 passes through the positioning hole 11 and the load-bearing sleeve 21; the hydraulic locking mechanism 4 includes a high-pressure oil chamber 41, a piston push block 42 and a locking bolt 43, the piston push block 42 is driven by oil pressure to press against the side of the dovetail boss 22, and the locking bolt 43 is tightened to lock the piston push block 42.

[0032] During installation, the upper connecting plate 1 and the lower connecting plate 2 are fixed together by left and right insertion. After insertion, the dovetail boss 22 is inserted into the guide groove 12. The self-lubricating bushing 32 is placed inside the load-bearing sleeve 21 and pressed into the head pin 31. The head pin 31, in conjunction with the positioning hole 11 and the load-bearing sleeve 21, forms an interference-fit conical surface, achieving initial installation. The taper angle of the head pin 31 is 6°. The piston pusher 42 is driven by hydraulic oil to press against the side of the dovetail boss 22, achieving further locking installation. The piston pusher 42 is further tightened to prevent detachment by tightening the locking bolt 43, achieving final installation. After the torque tightening of the locking bolt 43 is completed, the pressure relief safety valve 45 is opened to release the oil pressure in the high-pressure oil chamber 41, and the external hydraulic hose and pump station are removed. At this time, the piston pusher 42 is mechanically fixed by the locking bolt 43, and the hydraulic locking mechanism 4, as an independent module, can be disassembled from the lower connecting plate 2, with only the mechanical locking structure remaining to bear the long-term load.

[0033] Further configuration: A limiting baffle 13 is provided on the inner end face of the guide groove 12. The limiting baffle 13 is used to restrict the position of the dovetail boss 22.

[0034] Further details: The contact surface between the guide groove 12 and the dovetail boss 22 is provided with micro-serrated anti-slip textures, with a tooth depth of 0.1-0.3mm and a tooth pitch of 2-5mm. This addresses the issue that traditional planar contact joints in the prior art are prone to relative sliding under shear loads, leading to displacement and structural noise. In this embodiment, the above design increases the coefficient of friction, reduces displacement and sliding under the same load, and thus significantly reduces wear.

[0035] Further configuration: The hydraulic locking mechanism 4 integrates a pressure sensor 44 and a pressure relief safety valve 45. The pressure sensor 44 monitors pressure changes in real time. When the pressure exceeds a threshold, the pressure relief safety valve 45 opens to release pressure, preventing structural damage and significantly improving the system's protection success rate.

[0036] Further details: The self-lubricating bushing 32 is made of PTFE-bronze composite material, with a thickness of 8%-12% of the pin diameter. The self-lubricating bushing 32 utilizes PTFE-bronze composite material, achieving its self-lubricating function through the complementary properties of the two materials: PTFE (polytetrafluoroethylene) characteristics: It has an extremely low coefficient of friction (0.05-0.1), is resistant to high and low temperatures (-200℃ to 260℃), and has strong chemical stability, reducing contact surface friction even without external lubrication. Bronze matrix support: It provides a high-strength mechanical support framework, preventing PTFE from undergoing plastic deformation under high loads. Simultaneously, the porous structure of bronze can store trace amounts of lubricant (such as PTFE wear particles), forming a dynamic lubricating film. Composite action mechanism: When the joint is under load, the PTFE surface preferentially contacts the pin, reducing friction through molecular chain slippage; the bronze matrix absorbs vibration energy, inhibiting bushing deformation. The synergistic effect of both achieves the dual function of "self-lubrication + structural support."

[0037] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the utility model in any way. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model, or modify it into equivalent embodiments, without departing from the technical principles and scope of this utility model. Therefore, any combination, modification, or substitution made to the disclosed technical features of this utility model based on its technical essence, without departing from the principles or solution of this utility model, should fall within the protection scope of this utility model.

Claims

1. A detachable aircraft fuselage keel joint, characterized in that, include: The upper connecting plate (1), the lower connecting plate (2), the positioning pin assembly (3), and the hydraulic locking mechanism (4) are provided. The upper connecting plate (1) is provided with a tapered positioning hole (11) and a wedge-shaped guide groove (12). The lower connecting plate (2) is provided with a load-bearing sleeve (21) coaxial with the positioning hole (11) and a dovetail boss (22) matching the guide groove (12). The positioning pin assembly (3) is composed of a tapered head pin (31) and a self-lubricating bushing (32). The head pin (31) passes through the positioning hole (11) and the load-bearing sleeve (21). The hydraulic locking mechanism (4) includes a high-pressure oil chamber (41), a piston push block (42), and a locking bolt (43). The piston push block (42) is driven by oil pressure and presses against the side of the dovetail boss (22). The locking bolt (43) locks the piston push block (42) after tightening.

2. The detachable aircraft fuselage keel joint as described in claim 1, characterized in that: The guide groove (12) has a limiting baffle (13) on its inner end face.

3. A detachable aircraft fuselage keel joint as described in claim 1, characterized in that: The taper angle of the head pin (31) is 5°-8°.

4. A detachable aircraft fuselage keel joint as described in claim 3, characterized in that: The contact surface between the guide groove (12) and the dovetail boss (22) is provided with micro-serrated anti-slip texture, with a tooth depth of 0.1-0.3mm and a tooth pitch of 2-5mm.

5. A detachable aircraft fuselage keel joint as described in claim 4, characterized in that: The hydraulic locking mechanism (4) integrates a pressure sensor (44) and a pressure relief safety valve (45).

6. A detachable aircraft fuselage keel joint as described in any one of claims 1-5, characterized in that: The self-lubricating bushing (32) is made of PTFE-bronze composite material with a thickness of 8%-12% of the pin diameter.

Images