Novel anti-crash expansion type energy absorption structure of self-adaptive load aircraft

Abstract

The invention discloses a novel load-adaptive anti-crash expansion type energy absorption structure of an aircraft, which belongs to the technical field of safety protection of aircrafts and comprises an impact rod, an impact head, an expansion component and an energy absorption pipe. The impact rod is fixed to the circular-truncated-cone-shaped impact head, an inclined convex face and at least three grooves are arranged on the periphery of the impact head, and a mounting structure is arranged at the other end of the impact rod. The expansion assembly is composed of at least three sub-assemblies, each sub-assembly comprises an inclined concave face attached to the inclined convex face of the impact head, a convex face in interference fit with the energy absorption pipe and a convex head matched with the groove of the impact head, and the sub-assemblies and the impact head are tightly held initially. The energy absorption pipe is divided into the expansion part and the energy absorption part, the energy absorption section is longer than the fixed section, the number of core components is small, assembling is easy, the impact head and the expansion assembly are made of high-strength steel and can be repeatedly used, sub-assemblies slide to achieve progressive energy absorption, the energy absorption amount can be adjusted in a self-adaptive mode according to the impact speed, the energy absorption device is suitable for complex falling and collision scenes, cost is reduced, and safety is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft safety protection, in particular to a new type of anti-crash inflatable energy-absorbing structure of an aircraft with self-adaptive load. BACKGROUND

[0002] With the rapid development of general aviation technology, the anti-crash capability of an aircraft has become one of the core indicators for measuring its safety performance. When an aircraft is accidentally crashed, the cushioning and energy-absorbing structure, as a key component for protecting passengers and on-board equipment, directly determines the survival probability of the aircraft and the safety of the passengers.

[0003] At present, the commonly used anti-crash cushioning and energy-absorbing structures of general aircrafts are mainly designed based on the principle of material crushing, including oil and gas type buffers, thin-walled energy-absorbing structures, and cutting type energy-absorbing structures. These existing structures have many shortcomings in practical application:

[0004] Most of the existing energy-absorbing structures are designed for one-time use, and after use, they are completely scrapped due to plastic deformation of the structure or jamming of the components, which cannot realize the reuse of key components, resulting in a significant increase in the maintenance and use cost of the aircraft;

[0005] The existing structures are prone to generate a large initial crushing force peak at the initial stage of the collision, and the peak impact reaction force will be directly transmitted to the passengers and on-board equipment, which can easily cause serious injury;

[0006] In the stable working stage, the crushing force of the existing structure usually fluctuates around a fixed platform force, and it is difficult to form a gradual energy-absorbing process in which the impact force gradually increases with the compression stroke, which cannot balance the contradiction between "smooth energy absorption" and "large energy absorption requirement";

[0007] The design parameters (such as crushing strength and energy absorption) of the existing structure are fixed after manufacturing, and the energy absorption effect cannot be flexibly adjusted according to the actual crash conditions (such as impact speed and impact load difference) of the aircraft, which is difficult to adapt to complex crash scenarios.

[0008] For example, the "inflatable energy-absorbing anti-climbing device" with publication number CN220096368U includes a mounting seat, an inflation pipe, an impact pipe, and an anti-climbing tooth plate. The device realizes energy absorption by inserting the impact inflation head into the inflation pipe. It has the advantages of compact structure and long buffer stroke. However, the device still has obvious defects: the impact inflation head and the inflation pipe are in interference fit, and the inflation head is deeply embedded in the inflation pipe after impact, which is difficult to disassemble and recycle, and the key components cannot be reused. At the same time, the impact force cannot be self-adaptively adjusted according to the impact conditions during the energy-absorbing process, and it cannot form a gradual energy-absorbing process, which still cannot meet the high safety requirements of the aircraft in complex crash scenarios.

[0009] Therefore, it is urgent to provide a reusable aircraft new anti-crash inflatable energy-absorbing structure with safe and smooth energy-absorbing process and adaptive load suitable for different crash conditions. SUMMARY

[0010] The purpose of the present application is to provide a new aircraft anti-crash inflatable energy-absorbing structure with adaptive load to overcome the above technical problems.

[0011] The present application solves the above technical problems by the following technical solutions:

[0012] The present application provides a new aircraft anti-crash inflatable energy-absorbing structure with adaptive load, comprising: an impact rod, an impact head, an expansion assembly and an energy-absorbing pipe; the impact rod is fixedly connected with the impact head, the impact head is in the shape of a circular truncated cone, and an impact head inclined convex surface is arranged on the outer periphery of the impact head; at least three impact head grooves are uniformly distributed on the impact head inclined convex surface; the expansion assembly is composed of at least three identical sub-assemblies; each sub-assembly is provided with an expansion assembly inclined concave surface, an expansion assembly convex surface and an expansion assembly convex head; the expansion assembly convex head is adapted to the impact head groove; the expansion assembly inclined concave surface is in close contact with the impact head inclined convex surface; in the initial state, the impact head is in close contact with at least three sub-assemblies; the energy-absorbing pipe comprises an expansion part and an energy-absorbing part; the expansion assembly convex surface is in interference fit with the expansion part.

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

[0014] Further, the number of sub-assemblies of the expansion assembly is 3-8, and each sub-assembly is in the shape of a circle in the initial state after splicing.

[0015] Further, the interference fit tolerance between the expansion assembly convex surface and the expansion part of the energy-absorbing pipe is H7 / p6.

[0016] Further, the taper of the impact head is 1:3-1:7.

[0017] Further, the tapered diameter structure of the impact head is in the shape of a circular truncated cone, the inclined fitting surface is an inclined convex surface on the outer periphery of the circular truncated cone, and the fitting surface of the sub-assembly is an inclined concave surface in close contact with the inclined convex surface.

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

[0019] Further, the number of impact head grooves is 6.

[0020] Further, the length of the energy-absorbing section of the energy-absorbing pipe is greater than the length of the fixed section.

[0021] Advantages:

[0022] 1、The application has simple and reliable structure, is easy to implement, has only four core components, is assembled by mechanical cooperation, does not need complex electric control system, has low production and assembly difficulty, has high working stability, and is suitable for engineering application.

[0023] 2、The impact head and the expansion assembly are made of high-strength steel, and do not have plastic deformation during work; the circular truncated cone structure of the impact head and the block design of the expansion assembly enable the subassembly to be easily reset, exit from the energy absorption pipe, and be repeatedly assembled and used, solve the problem of "one-time scrapping" of the existing structure, and significantly reduce the use and maintenance cost.

[0024] 3、Through the design that the subassembly slides with the impact stroke and the expansion radius gradually increases, the impact force gradually increases from a low peak value, gradual energy absorption can be realized, and the structure avoids the defect that the initial impact peak value of the existing structure is large, so that the buffer energy absorption process is more in line with the anti-impact safety requirements of the human body and equipment.

[0025] 4、The application utilizes the correlation between inertial force and expansion radius to realize self-adaptive adjustment that "the greater the impact speed is, the greater the energy absorption is", does not need manual intervention to adapt to different falling conditions, and greatly improves the universality and protection range of the structure. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic view of the overall structure of the application, wherein: Figure 1 (a) is a front view of the overall structure of the application, Figure 1 (b) is an oblique view of the overall structure of the application;

[0027] Figure 2 It is a schematic view of the impact component structure of the application;

[0028] Figure 3 It is a schematic view of the expansion assembly structure of the application, wherein: Figure 3 (a) is a front view of the expansion assembly of the application, Figure 3 (b) is a left view of the expansion assembly of the application, Figure 3 (c) is an oblique view of the expansion assembly of the application, Figure 3 (d) is an oblique view of the subassembly of the expansion assembly of the application;

[0029] Figure 4 It is a schematic view of the energy absorption pipe structure of the application;

[0030] Figure 5 It is a schematic view of the impact force-time history curve of the application under different impact speeds.

[0031] Figure: 1, impact rod; 2, impact head; 3, expansion assembly; 4, energy absorption pipe; 5, impact head groove; 6, impact head inclined convex surface; 7, subassembly; 8, expansion assembly convex surface; 9, expansion assembly inclined concave surface; 10, expansion assembly convex head; 11, expansion part; 12, energy absorption part. DETAILED DESCRIPTION

[0032] As Figures 1-4 shown, the embodiment discloses a new type of anti-crash inflatable energy absorption structure of an aircraft with adaptive load, the core of which is to realize "progressive energy absorption" and "load adaptive adjustment" through the coordinated cooperation of the impact rod, the circular truncated cone impact head, the block type expansion assembly and the plastic deformation energy absorption pipe, while ensuring the reuse of key components. The overall structure is shown in Figure 1 , which is mainly composed of four core components: impact rod 1, impact head 2, expansion assembly 3, and energy absorption pipe 4. The specific structure of each component corresponds to Figure 2 (Impact component), Figure 3 (expansion assembly), Figure 4 (energy absorption pipe), and the material, size and matching relationship of each component meet the technical features defined in the claims, and the specific parameters are as follows.

[0033] 1. Impact component

[0034] Impact rod 1: made of high-strength steel (tensile strength ≥980MPa); the end away from the impact head 2 is provided with a flange, and four installation holes with a diameter of 8mm are uniformly arranged along the circumference of the flange, which are used for bolt connection with the fixed support at the bottom of the aircraft fuselage or passenger cabin, to ensure that the impact load can be stably transmitted to the energy absorption structure.

[0035] Impact head 2: fixedly connected with the impact rod 1 by arc welding (welding strength ≥800MPa), and the overall structure is a circular truncated cone with gradually changing diameter, and the material is the same as that of the impact rod, which does not deform plastically during work. The key parameters are as follows:

[0036] Conicity: 1:5.5;

[0037] Outer diameter: 168mm;

[0038] Outer circumferential surface: provided with an impact head inclined convex surface 6 coaxial with the circular truncated cone (the inclination angle matches the conicity, about 11.3°), and six impact head grooves 5 are uniformly distributed along the circumference of the convex surface; each groove 5 is a rectangular structure, which is adapted to the convex head of the expansion assembly.

[0039] 2. Expansion assembly 3

[0040] The expansion assembly 3 is designed in a block type, which is composed of six identical subassemblies 7. The initial state of the subassemblies 7 after splicing is a complete circular structure, and the material is high-strength steel, which does not deform plastically during work. The specific structure of each subassembly 7 is as follows:

[0041] The inclined concave surface 9 of the expansion assembly is completely matched with the inclined convex surface 6 of the impact head, the inclined angle is matched with the taper of the impact head, the surface roughness of the concave surface is less than or equal to 1.6 microns, and the sliding friction resistance is reduced.

[0042] The convex surface 8 of the expansion assembly is located at the outer periphery of the subassembly 7, the convex surface arc is matched with the inner hole arc of the expansion part 11 of the energy absorption pipe, the convex surface forms a circle after initial splicing, and is used for interference fit with the energy absorption pipe.

[0043] The convex head 10 of the expansion assembly is located at the inner side (close to the impact head side) of the subassembly 7, is a rectangular protruding structure, the size is matched with the groove 5 of the impact head, the convex head and the groove are matched in clearance, and it is ensured that the subassembly 7 can slide along the convex head.

[0044] 3. Energy absorption pipe 4

[0045] The energy absorption pipe 4 is made of low carbon steel (elongation is greater than or equal to 26%), has good plastic expansion capacity, and can absorb impact kinetic energy through plastic deformation. The structure is divided into two sections.

[0046] The expansion part 11 (fixed section) is located at the front end of the energy absorption pipe 4. When the energy absorption pipe 4 is assembled with the expansion assembly 3, it is pre-pressed to a preset position by a special pressing equipment. The front end of the energy absorption pipe 4 is deformed under the action of the expansion assembly 3, forms the expansion part 11, and is tightly connected with the expansion assembly 3.

[0047] The energy absorption part 12 (deformation section) is located at the rear end of the energy absorption pipe 4, the inner hole diameter is 144 mm, and the thickness is 7 mm. The inner wall of the energy absorption part 12 is not additionally processed, which is convenient for stable plastic deformation when the expansion assembly 3 expands.

[0048] Assembly process:

[0049] The assembly steps of the energy absorption structure of the embodiment are as follows, which ensure that the matching relationship of each component meets the design requirements.

[0050] Impact component assembly: the impact rod 1 and the impact head 2 are connected by electric arc welding. After welding, the weld is detected by ultrasonic detection, and the inclined convex surface 6 and the groove 5 of the impact head are finely ground to ensure the surface precision.

[0051] Expansion assembly pre-assembly: the expansion assembly convex heads 10 of the six subassemblies 7 are correspondingly embedded in the six grooves 5 of the impact head 2, so that the inclined concave surfaces 9 of the six subassemblies 7 are completely matched with the inclined convex surface 6 of the impact head. At this time, the circular structure formed by the six subassemblies 7 is tightly held, and there is no obvious gap between the subassemblies.

[0052] Energy absorption pipe assembly: the expansion assembly 3 and the energy absorption pipe 4 are pre-pressed by a special pressing equipment, so that the rear end of the energy absorption pipe is deformed to form the expansion part 11, and is tightly sleeved on 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 device includes an impact rod, an impact head, an expansion assembly, 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 assembly consists of at least three identical sub-assemblies, each of which has an inclined concave surface, a convex surface, and a protruding head. The protruding head is adapted to the grooves of the impact head, and the inclined concave surface of the expansion assembly fits against the inclined convex surface of the impact head. In the initial state, the impact head and at least three sub-assemblies are tightly fitted together. 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.

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 head has a tapered diameter structure in the shape of a frustum, 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.

7. The novel adaptive load-bearing, crash-resistant, expansion-type energy-absorbing structure for aircraft according to claim 1, characterized in that, The impact rod has an installation structure at the end away from the impact head.

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

9. The novel adaptive load-bearing, crash-resistant, expansion-type 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.

Images