A Variable Damping and Recoverable Landing Buffer Device for a Lunar Aircraft and Its Working Method

Abstract

The present invention discloses a variable-damping recoverable landing buffer device and working method for a lunar aircraft. The landing buffer device is located at the bottom of the lunar aircraft and is composed of an outer cylinder, a push rod, a foot pad, an annular partition, a powder damping material, a flexible limiting element, a conical head, an elastic element, and a sleeve. The conical head is arranged with its large end facing upward at the top of the push rod. When the aircraft lands, the impact energy is consumed by the extrusion and friction between the conical head and the powder damping material, and part of the potential energy is stored by the elastic element. When the aircraft takes off again, the elastic element gradually releases the stored energy, and the deformation of the buffer device can be completely restored to the initial state. This buffer device has the characteristic of variable damping and can enable the lunar aircraft to achieve multiple landing buffering without external energy. At the same time, the device is stable and reliable and can still effectively play its role in the extreme lunar environment.

Description

Technical Field

[0001] The present invention relates to the field of landing buffering, and particularly to a variable-damping recoverable landing buffering device and working method for a lunar aircraft. Technical Background

[0002] In future lunar exploration projects, lunar aircraft will perform large-scale scientific research tasks on the lunar surface. Therefore, it is required that the aircraft have the ability to take off and land multiple times in the lunar environment. However, the landing vehicles used in existing lunar exploration tasks can only perform single buffering. Taking the "Chang'e-4" project as an example, the landing vehicle uses aluminum honeycomb as the main buffering material. During the buffering process, although the aluminum honeycomb absorbs a large amount of impact energy, it also undergoes plastic deformation itself and cannot be reused. At present, there is still no effective solution to the problem of recoverable buffering for lunar aircraft in the world, and no country can use the aircraft to achieve large-scale detection work in a single lunar exploration mission. Therefore, conducting research on this problem and achieving a technological breakthrough in recoverable buffering devices is a prerequisite and key technical guarantee for the next stage of lunar exploration tasks.

[0003] In summary, aiming at the technical bottleneck in the field of landing buffering, inventing a recoverable landing buffering device for lunar aircraft has important value for the in-depth promotion of lunar exploration projects. Summary of the Invention

[0004] In view of the above technical problems, the present invention proposes a variable-damping recoverable landing buffering device and working method for a lunar aircraft. The device has the characteristics of recoverability, high damping, and high stability. During the landing process of the aircraft, it can absorb or dissipate impact energy to keep the aircraft stable; when the aircraft ascends, the device can return to its initial state without relying on external energy to maintain the ability of multiple buffering; at the same time, the device should also be applicable to the complex environmental conditions on the lunar surface.

[0005] In order to achieve the above technical objectives, the technical means adopted by the present invention are as follows:

[0006] A variable-damping recoverable landing buffering device for a lunar aircraft, comprising:

[0007] An outer cylinder, which is a cylindrical cylinder with both ends closed and a hollow interior. The upper surface is connected to the aircraft body through a connecting mechanism, and a circular hole communicating with the inner cavity of the outer cylinder is opened at the center of the lower surface;

[0008] An annular partition, which is arranged inside the outer cylinder, parallel to the top surface of the outer cylinder, and divides the inner cavity of the outer cylinder into a first cavity located in the upper part and a second cavity located in the lower part from top to bottom;

[0009] A flexible limiting element, which is filled in the first cavity, located above the annular partition, with the top surface contacting the upper surface of the outer cylinder and the side surface being restricted by the inner wall of the outer cylinder;

[0010] Powder damping material is filled in the second cavity and the gap between the flexible limiting element and the outer cylinder in the first cavity;

[0011] The sleeve is located at the bottom of the outer cylinder and is arranged along the same axis as the outer cylinder; the sleeve has an open lower end and a closed upper end, the upper closed end is fixed to the bottom surface of the outer cylinder, and a circular through hole is provided at the center of the closed end;

[0012] An elastic element, the top end of which is arranged inside the sleeve and in close contact with the closed end of the sleeve;

[0013] The push rod passes through the elastic element and the sleeve from bottom to top along the axis, and then extends into the second cavity of the outer cylinder through the circular hole on the bottom surface of the outer cylinder. A conical head is fixed on the top of the push rod. The conical head is in the shape of a water drop, with the large end facing upward and the small end facing downward. The inner diameter of the annular partition is larger than the maximum cross-sectional diameter of the conical head, so as to ensure that the conical head can pass through the annular partition and enter the second cavity of the outer cylinder.

[0014] The foot pad is located at the bottom of the device and is hinged to the push rod at the center, with an upper surface supporting the elastic element and a lower surface directly contacting the moon surface.

[0015] Furthermore, the flexible limiting element is made of high-strength, high-toughness and stable-performance metal wire that is stretched and curled into a micro spring, and then formed into a mesh structure by weaving layer by layer. During the compression process, the metal wires that make up the mesh buffer element rub against each other to dissipate energy.

[0016] Furthermore, the metal wire includes any one or a combination of ultra-high strength steel wire, high entropy alloy wire, and Invar alloy wire.

[0017] Furthermore, the powder damping material is high-purity carbon powder or silicon powder.

[0018] Furthermore, the elastic element is a coil spring.

[0019] Furthermore, the distance between the conical head and the annular partition is not less than the maximum buffer stroke of the device;

[0020] Furthermore, the limit deformation of the elastic element is greater than the maximum buffer stroke of the device;

[0021] The static load deformation of the elastic element meets the load-bearing requirements of the upper aircraft.

[0022] Furthermore, a sealing ring is arranged around the hole wall at the bottom opening of the outer cylinder to ensure that the inner cavity of the outer cylinder is completely sealed after the push rod is inserted into the outer cylinder.

[0023] Furthermore, the closed end of the sleeve is connected to the bottom surface of the outer cylinder via threads, and the annular partition is welded to the inner wall of the outer cylinder.

[0024] The present invention further discloses a working method based on the variable-damping recoverable landing buffer device of the lunar aircraft. According to different working states of the aircraft, it is divided into four stages:

[0025] During the landing process of the aircraft, the footpad impacts the lunar surface, driving the push rod and the upper conical head to move upward. At this time, the large end of the conical head interacts with the powder damping material in the second cavity of the outer cylinder, squeezing and rubbing the damping powder, consuming a large amount of impact energy, generating a buffering effect, and keeping the upper aircraft stable during landing; at the same time, the upward movement of the push rod will also cause the elastic element to undergo compressive deformation and store part of the potential energy;

[0026] After the aircraft lands, the elastic element releases part of the energy, and part of the deformation of the device returns to its original position. Due to the damping effect between the conical head and the powder, the deformation recovery of the device is slow, and the upper aircraft remains in a stable state. When the aircraft is in a static state, the elastic element bears the static load of the aircraft;

[0027] When the aircraft takes off again, the elastic element releases all the energy, driving the push rod and the conical head to move downward. At this time, the small end of the conical head interacts with the powder damping material in the outer cylinder. Compared with the landing, the damping of the device decreases, so it can be completely restored to the initial state, maintaining the repeatable buffering ability;

[0028] In extreme cases, when the aircraft is subjected to a large impact, the deformation of the device will exceed the set buffering stroke. At this time, the push rod continues to move upward, and the conical head will pass through the annular partition hole into the first cavity and squeeze the internal flexible limiting element. The flexible limiting element further enhances the energy consumption capacity of the device. At the same time, the flexible limiting element restricts the push rod from continuing to move upward to prevent damage to the upper aircraft and internal precision equipment.

[0029] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0030] First, the device has the ability of repeated buffering. During the landing process of the aircraft, the device relies on the squeezing and friction effect between the conical head and the powder damping material to consume the impact energy and ensure the smooth landing of the aircraft; after the aircraft takes off again, the elastic element in the device releases the potential energy, and the device can gradually return to the initial state. During the whole process, the core components of the device do not undergo permanent deformation, the performance of the device does not degenerate, and the device can perform multiple repeated buffering.

[0031] II. The device has variable damping characteristics during the buffering and recovery processes. When the aircraft lands, the push rod in the device moves upward, and the large end of the conical head at the upper end of the push rod interacts with the powder damping material. The device has a high damping and can quickly consume the impact energy of the aircraft. When the aircraft takes off, the push rod in the device moves downward. At this time, the small end below the conical head squeezes the powder damping material. Due to the reduced contact area, compared with when landing, the damping of the device will decrease, which is more conducive to the device's recovery of deformation.

[0032] III. The device has a flexible limit function. When the aircraft is subjected to a large impact, causing the deformation of the device to exceed the set maximum buffering stroke, the conical head at the upper end of the push rod of the device will enter the first cavity and contact the flexible limit element, which can effectively prevent the device from undergoing greater deformation. At the same time, after being impacted by the conical head, the flexible limit element will undergo compressive deformation, and the metal wires inside it will rub against each other during the deformation process to consume energy, further alleviating the impact on the device and protecting the upper aircraft from damage.

[0033] IV. The device can work stably under the extreme environmental conditions on the moon. The surface temperature on the moon ranges from 160 °C to -180 °C, and the environmental conditions are harsh. Conventional hydraulic buffering devices cannot work properly. The variable-damping recoverable landing buffer device for lunar aircraft of the present invention uses carbon powder or silicon powder as the core energy-consuming element, and a flexible limit element is made of high-strength metal wires. Both are high-stability materials and are not affected by temperature changes. They can still effectively play the role of landing buffering in the extreme environment on the moon. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a sectional view of a variable-damping recoverable landing buffer device for a lunar aircraft according to the present invention;

[0035] Figure 2 is a three-dimensional view of a variable-damping recoverable landing buffer device for a lunar aircraft according to the present invention;

[0036] Figure 3 is a detailed view of the flexible limit element in a variable-damping recoverable landing buffer device for a lunar aircraft according to the present invention;

[0037] Figure 4 is a detailed view of the push rod, conical head and elastic element parts in a variable-damping recoverable landing buffer device for a lunar aircraft according to the present invention;

[0038] In the figure, 1. outer cylinder; 2. powder damping material; 3. flexible limit element; 4. annular partition; 5. conical head; 6. elastic element; 7. sleeve; 8. sealing ring; 9. push rod; 10. foot pad. DETAILED DESCRIPTION OF THE INVENTION

[0039] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0040] like Figures 1 to 4 As shown, a variable damping recoverable landing buffer device for a lunar spacecraft according to the present invention mainly includes an outer tube 1, a powder damping material 2, a flexible limit element 3, an annular partition 4, a conical head 5, an elastic element 6, a sleeve 7, a sealing ring 8, a push rod 9 and a foot pad 10. Example

[0041] In the embodiment, a variable damping recoverable landing buffer device for a lunar spacecraft of the present invention is located at the bottom of the lunar spacecraft, with a total of four sets. A connecting structure is arranged on the top of each buffer device to connect with the main body of the lunar spacecraft, and the bottom contacts the lunar surface through a foot pad.

[0042] The outer cylinder 1, foot pad 10 and push rod 9 of the buffer device are made of aluminum alloy, which is light and has stable performance. The outer cylinder 1 is a hollow cylinder with a circular hole at the center of the lower bottom surface. The diameter of the circular hole is 2-3 mm larger than that of the push rod. The bottom end of the push rod 9 is connected to the foot pad 10, and the top end passes through the circular hole and penetrates into the inner cavity of the outer cylinder 1 from bottom to top. A sealing ring 8 is set between the push rod 9 and the circular hole at the bottom of the outer cylinder 1 to ensure that the inner cavity of the outer cylinder 1 is completely closed after the push rod 9 is inserted into the outer cylinder 1.

[0043] An annular partition plate 4 is arranged inside the outer cylinder 1 at a position 1 / 4 of the height of the outer cylinder top surface. The annular partition plate 4 is made of aluminum alloy and is parallel to the top surface of the outer cylinder 1. The inner part of the outer cylinder 1 is divided into a first cavity and a second cavity from top to bottom through the annular partition plate 4. The second cavity is mainly used for buffering energy consumption, and the first cavity is used for limiting the ultimate deformation of the buffer device.

[0044] The conical head 5 is fixed to the top of the push rod 9 and is usually located in the second cavity of the outer tube 1. The material is high-strength titanium alloy and the shape is teardrop-shaped. The conical head is set with the big end facing up and the small end facing down. Its maximum diameter should be smaller than the inner diameter of the annular partition 4 to ensure that it can pass through the annular partition 4 smoothly and enter the first cavity of the outer tube 1. At the same time, the surface of the conical head 5 can be properly polished to increase the friction energy dissipation capacity.

[0045] The inside of the second cavity of the outer cylinder 1 is filled with high-quality carbon powder. During the buffering process, the push rod 9 drives the conical head to move up and down, squeezes or rubs the high-quality carbon powder, and consumes the impact energy. In order to make the damping of the device meet the buffering requirements of the aircraft, when filling the carbon powder, the actual damping ratio of the device should be tested by special equipment, and the filling amount and filling density of the carbon powder should be adjusted according to the measurement results.

[0046] Inside the first cavity of the outer cylinder 1, a flexible limiting element 3 is provided. Its upper end is in close contact with the upper surface of the outer cylinder 1, and its lower end is supported above the annular partition 4. The main material of the flexible limiting element 3 is ultra-high-strength steel wire, which has the characteristics of high strength, high toughness, and high stability, and can adapt to the extreme temperature environment on the lunar surface. During processing, the steel wire is stretched and curled into a micro spring, and then a net-like structure is formed by layer-by-layer weaving. After weaving is completed, the net-like buffer element is placed in a mold and stamped to form a shape that coordinates with the inner cavity of the outer cylinder. When the deformation of the device exceeds the set buffer stroke, the conical head 5 at the upper end of the push rod 9 will contact the flexible limiting element 3 to prevent the deformation of the device from increasing further.

[0047] The elastic element 6 is a titanium alloy helical spring, which has the characteristics of high strength, high and low temperature resistance, and corrosion resistance. The elastic element 6 is nested outside the push rod 9, its top contacts the lower surface of the outer cylinder, and its bottom is supported above the foot pad 10. The sleeve 7 is arranged outside the elastic element 6 to fix the position of the elastic element 6. The sleeve 7 is made of titanium alloy, and its top is connected to the lower bottom surface of the outer cylinder 1 by threads.

[0048] Each component of the buffer device can be processed separately and then assembled in sequence. After assembly, 50 repeated buffer tests should be carried out to ensure that the device can meet the buffer requirements during lunar exploration.

[0049] The working method of a variable-damping recoverable landing buffer device for a lunar aircraft in an embodiment of the present invention is as follows:

[0050] According to different working states of the aircraft, it is divided into four stages. During the landing process of the aircraft, the foot pad impacts the lunar surface, driving the push rod and the upper conical head to move upward. At this time, the large end of the conical head interacts with the powder damping material in the second cavity located in the lower part of the outer cylinder, squeezing and rubbing the damping powder, consuming a large amount of impact energy, generating a buffering effect, and keeping the upper aircraft stable during landing. At the same time, the upward movement of the push rod will also cause the elastic element to undergo compressive deformation and store part of the potential energy.

[0051] After the aircraft lands, the elastic element releases part of the energy, and part of the deformation of the device is reset. Due to the damping effect between the conical head and the powder, the deformation recovery of the device is slow, and the upper aircraft is still in a stable state. When the aircraft is in a static state, the elastic element bears the static load of the aircraft.

[0052] When the aircraft takes off again, the elastic element releases all the energy, driving the push rod and the conical head to move downward. At this time, the small end of the conical head interacts with the powder damping material in the outer cylinder. Compared with when landing, the damping of the device decreases, so it can be completely restored to the initial state, effectively maintaining the repeatable buffering ability.

[0053] In extreme cases, when the aircraft is subjected to a large impact, the deformation of the device will exceed the set buffer stroke. At this time, the push rod continues to move upward, and the conical head will pass through the annular partition hole and enter the first cavity located in the upper part of the outer cylinder, and squeeze the internal flexible limiting element. The metal wires in the flexible limiting element rub against each other, further enhancing the energy dissipation capacity of the device. At the same time, the flexible limiting element can limit the further upward movement of the push rod to prevent damage to the upper aircraft and internal precision equipment.

Claims

1. A variable-damping recoverable landing buffer device for a lunar aircraft, characterized in that, include: The outer tube is a cylindrical tube with closed ends and hollow inside. The upper surface is connected to the aircraft body through a connecting mechanism, and a circular hole is provided in the center of the lower surface to connect to the inner cavity of the outer tube; an annular partition plate, arranged inside the outer cylinder, parallel to the top surface of the outer cylinder, and dividing the inner cavity of the outer cylinder into a first cavity located at the upper part and a second cavity located at the lower part from top to bottom; A flexible limiting element, filled in the first cavity, located above the annular partition, with its top surface in contact with the upper surface of the outer cylinder and its side surface constrained by the inner wall of the outer cylinder; Powder damping material is filled in the second cavity and the gap between the flexible limiting element and the outer cylinder in the first cavity; The sleeve is located on the bottom surface of the outer cylinder and is arranged along the same axis as the outer cylinder; the sleeve has an open lower end and a closed upper end, the upper closed end is fixed to the bottom surface of the outer cylinder, and a circular through hole is provided at the center of the closed end; An elastic element, the top end of which is arranged inside the sleeve and in close contact with the closed end of the sleeve; The push rod passes through the elastic element and the sleeve from bottom to top along the axis, and then extends into the second cavity of the outer cylinder through the circular hole on the bottom surface of the outer cylinder. A conical head is fixed on the top of the push rod. The conical head is in the shape of a water drop, with the large end facing upward and the small end facing downward. The inner diameter of the annular partition is larger than the maximum cross-sectional diameter of the conical head, so as to ensure that the conical head can pass through the annular partition and enter the second cavity of the outer cylinder. The foot pad is located at the bottom of the device and is hinged to the push rod at the center, with an upper surface supporting the elastic element and a lower surface directly contacting the moon surface.

2. The variable-damping recoverable landing buffer device for a lunar aircraft according to claim 1, characterized in that, The flexible limiting element is made of high-strength, high-toughness and stable-performance metal wire that is stretched and curled into a micro spring, and then woven layer by layer to form a mesh structure. During the compression process, the metal wires that make up the mesh buffer element rub against each other to dissipate energy.

3. The variable-damping recoverable landing buffer device for a lunar aircraft according to claim 2, characterized in that, The metal wire includes any one or a combination of ultra-high strength steel wire, high entropy alloy wire and Invar alloy wire.

4. A variable-damping recoverable lunar vehicle landing buffer device according to claim 1, characterized in that The powder damping material is high-purity carbon powder or silicon powder.

5. A variable-damping recoverable landing buffer device for a lunar aircraft according to claim 1, characterized in that, The elastic element is a coil spring.

6. The variable-damping recoverable landing buffer device for a lunar aircraft according to claim 1, characterized in that, The distance between the conical head and the annular partition is not less than the maximum buffer stroke of the device.

7. A variable-damping recoverable lunar vehicle landing buffer device according to claim 1, characterized in that, The limit deformation of the elastic element is greater than the maximum buffer stroke of the device; The static load deformation of the elastic element meets the load-bearing requirements of the upper aircraft.

8. A variable-damping recoverable landing buffer device for a lunar aircraft according to claim 1, characterized in that, A sealing ring is arranged around the hole wall at the bottom opening of the outer cylinder to ensure that the inner cavity of the outer cylinder is completely sealed after the push rod is inserted into the outer cylinder.

9. The variable-damping recoverable landing buffer device for a lunar aircraft according to claim 1, characterized in that, The closed end of the sleeve is connected to the bottom surface of the outer cylinder through threads, and the annular partition is welded to the inner wall of the outer cylinder.

10. A working method of a variable-damping recoverable lunar vehicle landing buffer device according to any one of claims 1 to 9, characterized in that, According to the different working states of the aircraft, it is divided into four stages: During the landing of the aircraft, the foot pad impacts the lunar surface, driving the push rod and the upper conical head to move upward. At this time, the large end of the conical head interacts with the powder damping material in the second cavity of the outer tube, squeezing and rubbing the damping powder, consuming a large amount of impact energy, producing a buffering effect, and keeping the upper aircraft stable during landing; at the same time, the upward movement of the push rod will also cause the elastic element to compress and deform, storing part of the potential energy; After the aircraft lands, the elastic element releases part of its energy, and the device partially deforms and returns to its original position. Due to the damping effect between the conical head and the powder, the deformation recovery of the device is slow, and the upper aircraft remains in a stable state. When the aircraft is stationary, the elastic element bears the static load of the aircraft; When the aircraft takes off again, the elastic element releases all of its energy, driving the push rod and the conical head to move downward. At this time, the small end of the conical head interacts with the powder damping material inside the outer cylinder. Compared with when landing, the damping of the device decreases, so it can fully return to its initial state, maintaining the repeatable buffering ability; In extreme cases, when the aircraft is subjected to a large impact, the deformation of the device will exceed the set buffering stroke. At this time, the push rod continues to move upward, and the conical head will pass through the annular partition hole into the first cavity and squeeze the internal flexible limiting element. The flexible limiting element further enhances the energy dissipation capacity of the device. At the same time, the flexible limiting element restricts the further upward movement of the push rod to prevent damage to the upper aircraft and internal precision equipment.

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