A new type of anti-crash inflatable energy-absorbing structure of an aircraft with adaptive load

Abstract

This invention discloses a novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft, belonging to the field of aircraft safety protection technology. The structure includes an impact rod, an impact head, an expansion assembly, and an energy-absorbing tube. The impact rod is fixed to a frustum-shaped impact head, the outer periphery of which has an inclined convex surface and at least three grooves. An installation structure is provided at the other end of the impact rod. The expansion assembly consists of at least three sub-assemblies, each including an inclined concave surface that fits against the inclined convex surface of the impact head, a convex surface that is interference-fitted with the energy-absorbing tube, and a protrusion that adapts to the grooves of the impact head, initially tightly fitting the impact head. The energy-absorbing tube is divided into an extension section and an energy-absorbing section, with the energy-absorbing section being longer than the fixed section. It has fewer core components and is simple to assemble. The impact head and expansion assembly are made of high-strength steel and can be reused. The sub-assemblies slide to achieve progressive energy absorption and can adaptively adjust the energy absorption according to the impact velocity, adapting to complex crash scenarios, reducing costs, and improving safety.

Description

Technical Field

[0001] This invention relates to the field of aircraft safety protection technology, specifically to a novel adaptive load-resistant anti-crash expansion energy-absorbing structure for aircraft. Background Technology

[0002] With the rapid development of general aviation technology, the crashworthiness of aircraft has become one of the core indicators for measuring their safety performance. In the event of an accidental aircraft crash, the energy-absorbing structure, as a key component protecting occupants and onboard equipment, directly determines the aircraft's survival probability and the safety of its occupants.

[0003] Currently, commonly used crash-resistant energy-absorbing structures for general aviation aircraft are mainly designed based on the principle of material crushing, including hydrant-pneumatic buffers, thin-walled energy-absorbing structures, and cutting-type energy-absorbing structures. These existing structures have many shortcomings in practical applications:

[0004] Existing energy-absorbing structures are mostly one-time designs. After use, they are completely scrapped due to plastic deformation of the structure or component jamming. This makes it impossible to reuse key components, resulting in a significant increase in aircraft maintenance and operating costs.

[0005] Existing structures are prone to generating large initial crushing force peaks in the early stages of a collision. These peak impact reaction forces are directly transmitted to the occupants and onboard equipment, which can easily cause serious injuries.

[0006] In the stable working phase, the crushing force of the existing structure usually fluctuates around the fixed platform force, making it difficult to form a gradual energy absorption process in which the impact force gradually increases with the compression stroke. This makes it impossible to balance the contradiction between "stable energy absorption" and "large energy absorption demand".

[0007] The design parameters of existing structures (such as crush strength and energy absorption) are fixed after manufacturing. They cannot flexibly adjust the energy absorption effect according to the actual crash conditions faced by the aircraft (such as impact velocity and impact load differences), making it difficult to adapt to complex and ever-changing crash scenarios.

[0008] For example, the "Inflatable Energy-Absorbing Anti-Climbing Device" disclosed in CN220096368U includes a mounting base, an expansion tube, an impact tube, and an anti-climbing toothed plate. Energy absorption is achieved by inserting an impact expansion head into the enlarged section of the expansion tube, offering advantages such as a compact structure and long buffer stroke. However, this device still has significant drawbacks: the impact expansion head and the expansion tube are interference-fitted, and after impact, the expansion head is deeply embedded in the expansion tube, making disassembly and recovery difficult and preventing the reuse of key components. Furthermore, the impact force during energy absorption cannot adaptively adjust to the impact conditions, nor can it achieve gradual energy absorption, thus failing to meet the high safety requirements of complex aircraft crash scenarios.

[0009] Therefore, there is an urgent need for a new type of crash-resistant expansion energy-absorbing structure for aircraft that is reusable, has a safe and stable energy absorption process, and is suitable for adaptive loads under different crash conditions. Summary of the Invention

[0010] The purpose of this invention is to provide a novel crash-resistant expansion energy-absorbing structure for aircraft with adaptive loads, in order to overcome the aforementioned technical problems.

[0011] The present invention solves the above-mentioned technical problems through the following technical solution:

[0012] A novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft is provided, comprising: an impact rod, an impact head, an expansion assembly, and an energy-absorbing tube; the impact rod is fixedly connected to the impact head, the impact head is frustum-shaped, and its outer peripheral surface is provided with an inclined convex surface of the impact head, and at least three impact head grooves are evenly distributed on the inclined convex surface of the impact head; the expansion assembly is composed of at least three identical sub-assemblies, each of the sub-assemblies having an inclined concave surface of the expansion assembly, an expansion convex surface of the expansion assembly, and an expansion head, the expansion head of the expansion assembly being adapted to the groove of the impact head, the inclined concave surface of the expansion assembly being in contact with the inclined convex surface of the impact head, and in the initial state, the impact head and at least three of the sub-assemblies being tightly engaged; the energy-absorbing tube includes an extension portion and an energy-absorbing portion, and the convex surface of the expansion assembly and the extension portion are interference-fitted.

[0013] Furthermore, the impact head and sub-assemblies are made of high-strength steel, and the energy-absorbing tube is made of a metal material with plastic deformation capability.

[0014] Furthermore, the expansion component has 3 to 8 sub-components, and the initial state of each sub-component after assembly is a circular structure.

[0015] Furthermore, the interference fit tolerance between the convex surface of the expansion component and the extension portion of the energy-absorbing tube is H7 / p6.

[0016] Furthermore, the taper of the impact head is 1:3 to 1:7.

[0017] Furthermore, the tapered diameter structure of the impact head is frustum-shaped, the inclined mating surface is an inclined convex surface on the outer periphery of the frustum, and the fitting surface of the sub-assembly is an inclined concave surface that fits against the inclined convex surface.

[0018] Furthermore, the end of the impact rod away from the impact head is provided with a mounting structure.

[0019] Furthermore, the impact head has six grooves.

[0020] Furthermore, the length of the energy-absorbing section of the energy-absorbing tube is greater than the length of its fixed section.

[0021] Beneficial effects:

[0022] 1. The present invention has a simple and reliable structure, is easy to implement, has only 4 types of core components, relies on mechanical coordination for assembly, does not require a complex electrical control system, has low production and assembly difficulty, high working stability, and is suitable for engineering applications.

[0023] 2. Both the impact head and the expansion assembly of this invention are made of high-strength steel and do not undergo plastic deformation during operation. Furthermore, the frustum-shaped structure of the impact head and the segmented design of the expansion assembly allow the sub-assemblies to be easily reset after impact, removed from the energy-absorbing tube, and reassembled for reuse. This solves the problem of "one-time scrapping" in existing structures and significantly reduces the cost of use and maintenance.

[0024] 3. By designing sub-components to slide with the impact stroke and gradually increase the expansion radius, the impact force gradually increases from the low peak value, which can achieve progressive energy absorption. At the same time, this structure avoids the defect of the large initial impact peak value of the existing structure, making the buffering energy absorption process more in line with the impact safety requirements of the human body and equipment.

[0025] 4. This invention utilizes the relationship between inertial force and expansion radius to achieve adaptive adjustment of "the greater the impact velocity, the greater the energy absorbed," adapting to different impact conditions without manual intervention, and greatly improving the versatility and protection range of the structure. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention, wherein: Figure 1 (a) is a front view of the overall structure of the present invention. Figure 1 (b) is a perspective view of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the impact component structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the expansion component structure of the present invention, wherein: Figure 3 (a) is a front view of the expansion component of the present invention. Figure 3 (b) is a left view of the expansion component of the present invention. Figure 3 (c) is a perspective view of the expansion component of the present invention. Figure 3 (d) is a perspective view of a sub-component of the expansion component of the present invention;

[0029] Figure 4 This is a schematic diagram of the energy-absorbing tube structure of the present invention;

[0030] Figure 5 This is a schematic diagram of the impact force-time history curves of the present invention at different impact velocities.

[0031] In the figure: 1. Impact rod; 2. Impact head; 3. Expansion assembly; 4. Energy-absorbing tube; 5. Impact head groove; 6. Impact head inclined convex surface; 7. Sub-assembly; 8. Expansion assembly convex surface; 9. Expansion assembly inclined concave surface; 10. Expansion assembly protrusion; 11. Extension section; 12. Energy-absorbing section. Detailed Implementation

[0032] like Figure 1-4 As shown in the figure, this embodiment discloses a novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft. The core of this structure lies in the synergistic cooperation of an impact rod, a frustum-shaped impact head, a segmented expansion assembly, and a plastically deformable energy-absorbing tube to achieve "progressive energy absorption" and "adaptive load adjustment," while ensuring the reusability of key components. Its overall structure is as follows: Figure 1 As shown, it mainly consists of four core components: impact rod 1, impact head 2, expansion assembly 3, and energy-absorbing tube 4; the specific structure of each component corresponds to... Figure 2 (Impact components) Figure 3 (Expansion component) Figure 4 (Energy-absorbing tube), and the materials, dimensions and fitting relationships of each component all meet the technical features defined in the claims, with specific parameters as follows.

[0033] 1. Impact components

[0034] Impact rod 1: Made of high-strength steel (tensile strength ≥980MPa); its end away from the impact head 2 is provided with a flange, and four mounting holes with a diameter of 8mm are evenly opened along the circumference of the flange for bolt connection with the fixed bracket at the bottom of the aircraft fuselage or crew cabin, so as to ensure that the impact load can be stably transferred to the energy-absorbing structure.

[0035] Impact head 2: Fixed to impact rod 1 by arc welding (weld strength ≥ 800MPa), it has a truncated cone-shaped, tapering diameter structure, and is made of the same material as the impact rod, preventing plastic deformation during operation. Its key parameters are as follows:

[0036] Taper: 1:5.5;

[0037] Outer diameter: 168mm;

[0038] Outer circumferential surface: It is provided with an inclined convex surface 6 of the impact head coaxial with the frustum (the inclination angle matches the taper, about 11.3°), and six impact head grooves 5 are evenly distributed along the circumference on the convex surface; each groove 5 is a rectangular structure, used to fit the convex head of the expansion assembly.

[0039] 2. Expansion Component 3

[0040] The expansion component 3 adopts a modular design, consisting of six identical sub-components 7. When assembled, each sub-component 7 initially forms a complete circular structure. It is made of high-strength steel and exhibits no plastic deformation during operation. The specific structure of each sub-component 7 is as follows:

[0041] The inclined concave surface 9 of the expansion component is fully fitted with the inclined convex surface 6 of the impact head, the inclination angle is matched with the taper of the impact head, and the surface roughness Ra of the concave surface is ≤1.6μm, which reduces sliding friction resistance.

[0042] The expansion component convex surface 8 is located on the outer periphery of the sub-component 7. The curvature of the convex surface matches the curvature of the inner hole of the energy-absorbing tube extension 11. After initial assembly, the convex surface forms a circle for interference fit with the energy-absorbing tube.

[0043] The expansion component protrusion 10 is located inside the sub-component 7 (near the impact head side), and is a rectangular protrusion structure. Its size is adapted to the impact head groove 5. The protrusion and the groove are fitted with a clearance to ensure that the sub-component 7 can slide along the protrusion.

[0044] 3. Energy Absorbing Tube 4

[0045] The energy-absorbing tube 4 is made of low-carbon steel (elongation ≥ 26%), possessing excellent plastic expansion capability, and can absorb impact kinetic energy through plastic deformation. Its structure consists of two sections:

[0046] Extension section 11 (fixed section): Located at the front end of the energy-absorbing tube 4. When the energy-absorbing tube 4 is assembled with the expansion component 3, it is pre-pressed to a preset position by a special pressing equipment. The front end of the energy-absorbing tube 4 expands and deforms under the action of the expansion component 3 to form the extension section 11, which is tightly connected to the expansion component 3.

[0047] Energy-absorbing section 12 (deformation section): located at the rear end of the energy-absorbing tube 4, with an inner diameter of 144 mm and a thickness of 7 mm. The inner wall of the energy-absorbing section 12 is not additionally processed, which facilitates stable plastic deformation when the expansion assembly 3 expands.

[0048] Assembly process:

[0049] The assembly steps of the energy-absorbing structure in this embodiment are as follows, ensuring that the fit between the components meets the design requirements:

[0050] Impact component assembly: The impact rod 1 and the impact head 2 are connected by arc welding. After welding, the weld is ultrasonically tested, and the inclined convex surface 6 and groove 5 of the impact head are precision ground to ensure surface accuracy.

[0051] Pre-installation of expansion components: The expansion component protrusions 10 of the six sub-components 7 are embedded into the six grooves 5 of the impact head 2, so that the inclined concave surface 9 of each sub-component 7 is completely in contact with the inclined convex surface 6 of the impact head. At this time, the six sub-components 7 tightly hug each other to form a circular structure, and there is no obvious gap between the sub-components.

[0052] Energy-absorbing tube assembly: The expansion assembly 3 and the energy-absorbing tube 4 are pre-pressed by a special press-fitting equipment, causing the rear end of the energy-absorbing tube to expand and deform, forming an extension 11, which is tightly fitted onto the expansion assembly 3.

[0053] Overall installation: The entire energy-absorbing structure is fixed to the aircraft's crash protection bracket using M8 high-strength bolts via the flange mounting structure at the end of the impact rod 1. The bolt preload torque is 25 N·m to ensure that the impact load can be transmitted axially.

[0054] Working principle:

[0055] The energy-absorbing structure in this embodiment achieves crash protection through "progressive energy absorption in a single impact" and "adaptive adjustment under different working conditions." The impact force-time history curves of the structure at different impact velocities are shown below. Figure 5 As shown. The specific working process is as follows:

[0056] When an aircraft crashes, the impact load is first transmitted to the impact rod 1. The impact rod 1 then compresses the impact head 2 and the expansion assembly 3 along the axial direction of the energy-absorbing tube 4 (from the extension section 11 to the energy-absorbing section 12).

[0057] Initial stage: The expansion component 3 and the extension 11 of the energy-absorbing tube 4 are interference fit. They move axially synchronously with the impact head 2. The energy-absorbing part 12 of the energy-absorbing tube 4 is squeezed by the convex surface 8 of the expansion component. Since the impact head 2 is frustum-shaped and the sub-component 7 can slide along the inclined convex surface 6 of the impact head, the sub-component 7 gradually overcomes the sliding friction between itself and the impact head under the action of the friction force of the inner wall of the energy-absorbing tube, and slides backward (away from the impact rod direction) along the inclined convex surface 6.

[0058] Progressive Expansion Stage: As sub-components 7 slide, the gaps between the six sub-components 7 gradually increase, the overall radius of the expansion component 3 gradually expands, and the energy-absorbing part 12 of the energy-absorbing tube 4 undergoes progressive plastic expansion deformation under the action of expansion force. The degree of expansion of the tube wall gradually increases, achieving a "progressive energy absorption" effect. In addition, compared with other types of energy-absorbing structures, the expansion deformation mode of this structure does not exhibit a large initial peak value of impact force or impact force fluctuations, and has the advantage of "stable energy absorption".

[0059] This structure utilizes the correlation between inertial force and impact velocity to achieve adaptive energy absorption under different impact conditions:

[0060] High impact velocity conditions: The initial impact velocity is high, the inertial force of the impact head 2 is large, and it penetrates the expansion component 3 to a deeper extent. The sub-component 7 slides a longer distance along the inclined convex surface 6 of the impact head, the maximum radius of the expansion component 3 is larger, and the plastic deformation of the energy-absorbing part 12 of the energy-absorbing tube 4 is greater (the tube wall is thinned more and the expansion range is wider), which in general meets the high energy absorption requirements of high-speed impact.

[0061] Low impact velocity conditions: The initial impact velocity is small, the inertial force of the impact head 2 is small, the sliding distance of the sub-component 7 is short, and the plastic deformation of the energy-absorbing tube 4 is small, so as to avoid excessive deceleration from harming the occupants and equipment, while ensuring the buffering effect.

[0062] After a single impact energy absorption event, the energy-absorbing part 12 of the energy-absorbing tube 4 has undergone plastic deformation, but the impact rod 1, impact head 2, and expansion assembly 3 (sub-assembly 7) have not deformed. During disassembly, only the impact head 2 needs to be removed; and the sub-assembly 7 of the expansion assembly 3 can slide in the opposite direction along the inclined convex surface 6 of the impact head 2 to return to the initial tightly bound state; after replacing the new energy-absorbing tube 4, the entire structure can be reassembled and used, and the reuse rate of the impact head and expansion assembly can reach more than 90%, significantly reducing the cost of use.

[0063] In summary, this embodiment, through specific structural design, parameter selection, and assembly method, fully realizes all the technical features defined in the claims, and effectively achieves the inventive objectives of "progressive and stable energy absorption," "load self-adaptation," and "reusability of key components," providing efficient and reliable crash protection for aircraft.

[0064] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship when the device or element is in normal use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation at any time, or be constructed and operated in a specific orientation, unless otherwise stated in the text.

[0065] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A novel crash-resistant, expandable energy-absorbing structure for aircraft with adaptive load characteristics, characterized in that: The assembly includes an impact rod, an impact head, an expansion component, and an energy-absorbing tube. The impact rod is fixedly connected to the impact head, which is frustum-shaped with an inclined convex surface on its outer circumference and at least three evenly distributed grooves on the inclined convex surface. The expansion component consists of at least three identical sub-components, each sub-component having an inclined concave surface, a convex surface, and a protruding head. The protruding head mates with the grooves in the impact head, and the inclined concave surface fits against the inclined convex surface of the impact head. (Initial state) The impact head is tightly fitted with at least three sub-assemblies. The energy-absorbing tube includes an extension and an energy-absorbing section. The convex surface of the expansion assembly is interference-fitted with the extension. The convex surface of the expansion assembly is located on the outer periphery of the sub-assembly, and the curvature of the convex surface matches the curvature of the inner hole of the energy-absorbing tube extension. The impact head is frustum-shaped, and its diameter gradually decreases from the impact rod to the convex surface of the expansion assembly. The inclined mating surface is the inclined convex surface on the outer periphery of the frustum. The fitting surface of the sub-assembly is an inclined concave surface that fits against the inclined convex surface.

2. The novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft according to claim 1, characterized in that, The impact head and sub-assemblies are made of high-strength steel, and the energy-absorbing tube is made of a metal material with plastic deformation capability.

3. The novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft according to claim 1, characterized in that, The expansion component has 3 to 8 sub-components, and the initial state of the assembled sub-components is a circular structure.

4. The novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft according to claim 1, characterized in that, The interference fit tolerance between the convex surface of the expansion component and the extension of the energy-absorbing tube is H7 / p6.

5. The novel adaptive load-bearing anti-crash expansion energy-absorbing structure for aircraft according to claim 1, characterized in that, The taper of the impact head is 1:3 to 1:

7.

6. The novel adaptive load-bearing, crash-resistant, expansion-type energy-absorbing structure for aircraft according to claim 1, characterized in that, The impact rod is provided with a mounting structure at the end away from the impact head.

7. The novel adaptive load-bearing, crash-resistant, expansion-type energy-absorbing structure for aircraft according to claim 1, characterized in that, The impact head has 6 grooves.

8. The novel adaptive load-bearing, crash-resistant, expandable energy-absorbing structure for aircraft according to claim 1, characterized in that, The length of the energy-absorbing section of the energy-absorbing tube is greater than the length of its fixed section.

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