A recoverable landing buffer mechanism and buffer method for a lunar probe

Abstract

The present invention discloses a recoverable landing buffer mechanism and a buffering method for a lunar probe. The buffer mechanism is located at the bottom of the landing leg of the lunar probe and is composed of an outer cylinder, a push rod, a foot pad, a mesh buffer element, a powder damping material, a viscoelastic damping element and a force transmission element. During the landing process of the probe, the foot pad and the push rod drive the force transmission element to move upward, compress the mesh buffer element, and at the same time shear and stretch the elastic damping element, consuming a large amount of impact energy, so that the probe can achieve a smooth landing; when the probe takes off again, the deformation of the mesh buffer element and the viscoelastic damping element will be slowly released, and the deformation of the buffer mechanism can be completely recovered. The buffer mechanism has the characteristics of high damping, recoverability and high stability. Without external energy, it not only has excellent single buffering effect, but also can meet the multiple buffering requirements during the takeoff and landing of the probe. At the same time, the mechanism can also work stably and efficiently for a long time in the extreme lunar environment.

Description

Technical Field

[0001] The present invention relates to the technical field of space exploration, and specifically to a recoverable landing buffer mechanism and a buffering method for a lunar probe. Technical Background

[0002] The moon is the celestial body closest to the earth, and it is the outpost and starting point of deep space exploration. Exploring the moon is an important link in understanding the solar system and the origin and evolution of life. In order to deeply carry out lunar exploration and achieve the strategic goal of a space power, China launched the "Chang'e Project" lunar exploration program in 2004. In the past 18 years, China's lunar exploration team has overcome a number of world-class problems and successfully completed the phased tasks of the first three phases of "orbiting", "landing" and "returning", making important contributions to enhancing national prestige and comprehensive national strength and promoting the development of international space technology. At present, the "Chang'e Project" has entered the second stage with the main framework of "exploration, landing and residence". China will carry out more long-term and in-depth exploration tasks on the moon, so there are more technical problems to be solved.

[0003] Developing an efficient and reusable detector landing buffer mechanism is the basis of lunar exploration tasks and one of the key technical problems that must be focused on breaking through at present. In order to achieve a soft landing on the lunar surface, among the lunar exploration tasks carried out by various countries in the world, the most mature and widely used technical means is to absorb shock energy through the plastic deformation of aluminum honeycomb. The above-mentioned scheme has excellent buffering effects, but it can only complete a single buffering task. Due to the limitations of buffering technology, at present, various countries in the world still adopt the method of fixed-point scientific research after landing on the lunar surface. After the detector lands stably, a small-scale exploration is carried out by a mobile lunar rover, and the exploration range is severely limited. In the future, the complexity of China's lunar exploration project will be significantly improved, and large-scale lunar surface exploration will become inevitable. This requires that the detector must have the ability to ascend and re-land, and the corresponding landing buffer mechanism must be able to buffer multiple times. However, at present, there is still no reliable solution for the problem of repeatable buffering in various countries in the world. Therefore, this has become the main technical bottleneck restricting the development of lunar exploration technology. Summary of the Invention

[0004] In view of the above technical problems, the present invention proposes a recoverable landing buffer mechanism and a buffering method for a lunar probe. This mechanism has the characteristics of recoverability, high damping and high stability. During the landing process of the detector, it can absorb or dissipate shock energy to keep the detector stable; when the detector ascends, the device can return to its initial state without relying on external energy and maintain the ability to buffer multiple times; at the same time, this mechanism 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 recoverable landing buffer mechanism for a lunar probe, comprising:

[0007] The outer cylinder is a cylindrical cylinder with open ends at both ends. An upper cover plate is provided at the upper end to form a closed end, and the lower end is spliced with a lower cover plate provided with a central circular hole; the top of the upper cover plate is connected to the main body part of the aircraft.

[0008] The push rod extends upward from the central circular hole of the lower cover plate into the inner cavity of the outer cylinder. The lower end of the push rod is hinged to a foot pad, and the upper end is fixedly connected to a force transmission element.

[0009] The mesh buffer element is filled in the inner cavity of the outer cylinder and is located between the lower surface of the upper cover plate and the force transmission element.

[0010] The powder damping material is filled in the gap between the mesh buffer element and the inner cavity of the outer cylinder to enhance the energy dissipation capacity of the mesh buffer element.

[0011] The viscoelastic damping element is a viscoelastic sheet with a central hole, located between the bottom end of the outer cylinder and the lower cover plate, and its edge is fixedly connected to the lower end of the outer cylinder and the upper end of the lower cover plate.

[0012] The force transmission element includes a first force transmission plate, a connecting rod and a second force transmission plate arranged on the same axis. Among them,

[0013] The first force transmission plate is located above the viscoelastic damping element, and the top surface is in close contact with the mesh buffer element.

[0014] The second force transmission plate is located below the viscoelastic damping element, and the bottom surface is fixedly connected to the push rod.

[0015] After the connecting rod passes through the central hole of the viscoelastic damping element, its upper end is fixedly connected to the first force transmission plate, and the lower end is fixedly connected to the second force transmission plate.

[0016] When the detector lands, the mesh buffer element undergoes compressive deformation, and the viscoelastic damping element undergoes tensile or shear deformation, consuming and storing part of the energy.

[0017] When the detector takes off, the stored energy is slowly released, and the deformation of the buffer mechanism gradually recovers. Since both are in the elastic stage, the deformation of the buffer mechanism finally recovers to the initial state.

[0018] Furthermore, the mesh buffer element is formed by stretching and curling high-strength, high-toughness and stable-performance metal wires into micro-springs, and then forming a mesh structure by layer-by-layer weaving. During the compression process, the metal wires constituting the mesh buffer element rub against each other to dissipate energy.

[0019] Furthermore, the metal wire includes any one or combination of ultra-high-strength steel wire, high-entropy alloy wire and invar alloy wire.

[0020] Furthermore, the powder damping material is high-purity carbon powder or silicon powder; the viscoelastic damping element is a high-dissipation viscoelastic material with a thickness of 1 / 5 to 1 / 7 of the diameter, which undergoes shear deformation under small deformation and tensile deformation under large deformation.

[0021] Furthermore, a plurality of threaded holes are uniformly arranged along the circumferential direction at the lower end of the outer cylinder; a plurality of circular holes are uniformly arranged along the circumferential direction at the outer edge of the viscoelastic damping element, the number of the circular holes is equal to the number of the threaded holes, and the positions correspond to the threaded holes; a plurality of counterbores are uniformly arranged along the circumferential direction at the outer edge of the lower cover plate, the number of the counterbores is equal to the number of the threaded holes and the circular holes, and the positions correspond; at the positions of the counterbores at the edge of the lower cover plate, a plurality of high-strength bolts sequentially pass through the counterbores and the circular holes and then are screwed into the threaded holes at the lower end of the outer cylinder to realize the fixed connection among the outer cylinder, the viscoelastic damping element and the lower cover plate.

[0022] Furthermore, in the force transmission element, the diameter of the first force transmission plate is 2 to 3 mm smaller than the inner diameter of the outer cylinder, and it is slidably connected with the outer cylinder, and at the same time, it has a sufficient contact area with the mesh buffer element;

[0023] The diameter of the connecting rod is equal to the diameter of the central circular hole of the viscoelastic damping element, and it is in close contact with the inner wall of the central circular hole of the viscoelastic damping element;

[0024] The diameter of the second force transmission plate is 3 to 4 times the diameter of the central circular hole of the viscoelastic damping element, ensuring that the viscoelastic damping element and the force transmission element do not become disengaged during the deformation process.

[0025] Furthermore, the side surface of the mesh buffer element is in contact with the inner wall of the outer cylinder, and the outer cylinder provides lateral restraint for the mesh buffer element to enhance the damping of the mesh buffer element.

[0026] Furthermore, the ultimate compression amount of the mesh buffer element and the ultimate tensile amount of the viscoelastic damping element are greater than the maximum buffer stroke of the mechanism.

[0027] The present invention further discloses a buffering method based on the recoverable landing buffering mechanism of the lunar probe. Before the lunar probe lands, the landing attitude is adjusted near the lunar surface to keep the upper probe stable and form a proper angle between the landing legs and the lunar surface. Then, the braking rocket is turned off for landing.

[0028] The recoverable landing buffer mechanism is located at the bottom of the detector's landing leg, and its top is connected to the landing leg. During the landing process of the detector, the lower footpad first impacts the lunar surface, and then pushes the push rod and the upper force transmission element to move upward in the inner cavity of the outer cylinder, compressing the mesh buffer element above the force transmission element. There is friction between the metal wires of the mesh buffer element and between the metal wires and the surrounding powder damping material, which will consume a large amount of impact energy. At the same time, as the force transmission element moves upward, the viscoelastic damping element will also undergo tensile deformation and can play an energy-consuming role. Under the combined action of the three energy-consuming mechanisms, the impact on the upper detector will be significantly reduced, and the detector can achieve a smooth landing;

[0029] After the landing is completed, the mesh buffer element and the viscoelastic damping element of the recoverable landing buffer mechanism will both store part of the potential energy, and the two together provide the bearing function for the upper detector. Since the mesh buffer element and the viscoelastic damping element are always in the elastic working state during the landing process, when the detector takes off again, the potential energy stored by the two will be slowly released and the deformation will gradually recover. Among them, the viscoelastic damping element has a strong self-resetting ability and will drive the push rod and the footpad to move downward as a whole. The mesh buffer element will gradually expand downward following the force transmission element. Since both of them have the characteristics of high damping, the deformation recovery process is relatively smooth and will not affect the upper detector. Finally, both of them will return to the initial state, and the landing buffer mechanism has the ability of repeated buffering;

[0030] When the impact on the detector is small, the mechanism will dissipate a large amount of impact energy through the shear deformation of the viscoelastic damping element. At this time, although the mesh buffer element is difficult to deform fully, the mechanism still has excellent buffering ability and the characteristics of repeatable buffering;

[0031] When the detector is subjected to a strong impact in extreme cases, as the compression amount of the mesh buffer element increases, the restraint effect of the outer cylinder on it increases. At the same time, as the tensile amount of the viscoelastic damping element becomes larger, its stiffness also gradually increases. The mechanism shows the characteristics of flexible self-limitation, which can effectively limit the continuous increase of the mechanism's deformation and protect the upper detector from being damaged.

[0032] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0033] First, the buffer mechanism has the characteristics of high damping and can produce excellent buffering effects. Three damping structures, namely the mesh buffer element, the powder damping material, and the viscoelastic damping element, are used inside the mechanism. During the landing process of the detector, the three work together to jointly consume the input impact energy. Therefore, the mechanism has strong buffering ability and can ensure the smooth landing of the upper detector on the lunar surface.

[0034] II. The buffer mechanism has a repeatable buffering ability and can perform multiple buffering operations. The net-shaped buffer element is filled in the inner cavity of the outer cylinder. The main material 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-shaped structure is formed by layer-by-layer weaving. During the landing process of the detector, the net-shaped buffer element undergoes compressive deformation, and the viscoelastic damping element undergoes tensile or shear deformation, storing part of the energy. When the detector takes off, the stored energy is slowly released, and the deformation of the buffer mechanism gradually recovers. Since both are in the elastic stage, the deformation of the buffer mechanism can ultimately recover to the initial state, and the mechanism has a repeatable buffering ability. At the same time, during the recovery process, the viscoelastic damper element can provide a high damping for the mechanism to prevent the mechanism from rebounding quickly. Therefore, the deformation recovery process of the buffer mechanism will be very smooth and will not affect the upper detector.

[0035] III. The buffer mechanism has a flexible self-limiting function and can effectively cope with extreme situations. When the detector is subjected to a strong impact, causing the buffer mechanism to undergo a large deformation, the constraint effect of the inner wall of the outer cylinder of the mechanism on the net-shaped buffer element will gradually increase, and the stiffness of the viscoelastic damping element will continuously increase, which can effectively limit the mechanism from undergoing a greater deformation and provide effective protection for the upper detector in extreme situations.

[0036] IV. The buffer mechanism has multiple energy dissipation mechanisms and can adapt to impacts of different degrees. When the impact on the detector is small, the impact energy is mainly dissipated through the shear deformation of the viscoelastic damping element. When the impact on the detector increases, the tensile deformation of the viscoelastic damping element and the compressive deformation of the net-shaped buffer element provide buffering effects. Therefore, controlled by multiple energy dissipation mechanisms, the mechanism can meet the energy dissipation requirements under different working conditions.

[0037] V. The viscoelastic damper element in the buffer mechanism adopts an assembled connection structure, meeting the usage requirements in the lunar environment. The viscoelastic damping element in the buffer mechanism is provided with round holes at the outer edge and is connected to the outer cylinder and the lower cover plate by high-strength bolts. At the central position, it is consolidated with the push rod by two layers of force transmission plates. The entire structure is physically connected and does not require the use of any chemical adhesives, eliminating the problem of adhesive interface failure, enabling the viscoelastic damper element to withstand large tensile and shear deformations and meeting the performance requirements during the buffering process of the mechanism. At the same time, the viscoelastic damping element can be separately processed and then assembled into the buffer mechanism, avoiding the complex vulcanization process. Therefore, this structure is suitable for use in lunar detectors and can enable the viscoelastic damper element to still maintain stable working performance in the lunar environment.

[0038] VI. The buffer mechanism has a simple structure and good sealing performance, and can work stably for a long time. The core components used in the buffer mechanism are all in a solid state and have relatively stable performance. The lower end of the mechanism is also completely sealed by viscoelastic damping elements and the lower cover plate. Therefore, compared with the hydraulic buffer method, the buffer mechanism of the present invention will not degrade in performance due to sealing problems and can work stably and efficiently for a long time in the extreme lunar environment. At the same time, the buffer mechanism does not rely on any external energy source and can achieve complex functions such as buffering, recovery, and limiting in the lunar environment only through a simple structure. Moreover, the buffer mechanism is entirely composed of lightweight components, with a small overall mass and will not generate excessive additional loads in the lunar probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a sectional view of a recoverable landing buffer mechanism for a lunar probe according to the present invention;

[0040] Figure 2 is a three-dimensional view of a recoverable landing buffer mechanism for a lunar probe according to the present invention;

[0041] Figure 3 is a detailed structural drawing of a mesh buffer element in a recoverable landing buffer mechanism for a lunar probe according to the present invention;

[0042] Figure 4 is a detailed structural drawing of a viscoelastic damping element in a recoverable landing buffer mechanism for a lunar probe according to the present invention;

[0043] In the figure, 1 is the outer cylinder; 1-1 is the outer cylinder threaded hole; 2 is the upper cover plate; 3 is the lower cover plate; 3-1 is the lower cover plate counterbore; 4 is the force transmission element; 4-1 is the first force transmission plate; 4-2 is the connecting rod; 4-3 is the second force transmission plate; 5 is the viscoelastic damping element; 5-1 is the circular hole at the edge of the viscoelastic damping element; 6 is the mesh buffer element; 7 is the powder damping material; 8 is the high-strength bolt; 9 is the push rod; 9-1 is the spherical hinge at the lower end of the push rod; 10 is the foot pad. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] Next, the technical solutions of the present invention will be further described in detail in conjunction with the accompanying drawings of the specification and specific embodiments.

[0045] As Figures 1 to 4 shown, a recoverable landing buffer mechanism for a lunar probe according to the present invention mainly includes an outer cylinder 1, an upper cover plate 2, a lower cover plate 3, a force transmission element 4, a viscoelastic damping element 5, a mesh buffer element 6, a powder damping material 7, a high-strength bolt 8, a push rod 9, and a foot pad 10. Embodiment

[0046] In an embodiment, a recoverable landing buffer mechanism of the lunar probe of the present invention is located at the bottom of the lunar probe, with a total of four sets. The top of each buffer mechanism is connected to the probe body through a connection structure provided on the surface of the upper cover plate, and the bottom contacts the lunar surface through a footpad.

[0047] In the buffer mechanism, the outer cylinder 1, the upper cover plate 2, the lower cover plate 3, the push rod 9 and the footpad 10 are all made of aluminum alloy, which is light in weight and stable in performance. Among them, the outer cylinder is a cylinder with both ends open, with external threads provided at the upper end for connection with the upper cover plate, and a group of threaded holes are evenly opened along the circumference at the lower end;

[0048] The net-shaped buffer element 6 is filled in the inner cavity of the outer cylinder 1, with its upper end tightly attached to the lower surface of the upper cover plate. The main material is ultra-high-strength steel wire, which has characteristics such as 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-shaped structure is formed by layer-by-layer weaving. After weaving is completed, the net-shaped buffer element is placed in a mold and stamped into shape to make it coordinated with the shape of the inner cavity of the outer cylinder. During the buffer process of the probe, the net-shaped buffer element generates compressive deformation, and the strands of steel wire will rub against each other, consuming the impact energy of the probe. The side surface of the net-shaped buffer element 6 is always in close contact with the inner wall of the outer cylinder. Under the constraint of the outer cylinder, its energy dissipation ability and self-resetting ability will be significantly improved.

[0049] High-quality carbon powder 7 is filled in the gap between the outer cylinder 1 and the net-shaped buffer element 6. Through the frictional action between the carbon powder 7 and the net-shaped buffer element 6, the damping of the mechanism during buffering is increased.

[0050] To ensure that the carbon powder 7 is densely filled in the gap between the net-shaped buffer element 6 and the outer cylinder 1, multiple net-shaped buffer elements 6 are arranged in series along the height direction of the inner cavity of the outer cylinder 1. During processing, after each layer of the net-shaped buffer element 6 is installed, high-quality carbon powder 7 can be filled in the inner cavity of the outer cylinder 1, and the high-quality carbon powder 7 is filled in the gap of the net-shaped buffer element 6, and then the next layer of the net-shaped buffer element 6 is installed.

[0051] The viscoelastic damping element 5 is made of a viscoelastic material with high energy dissipation ability, vulcanized and formed under high temperature and high pressure. Its shape is a circular thin sheet. After a hole is opened in the center, it is connected to the force transmission element. The edge is in close contact with the lower surface of the outer cylinder, and a circle of round holes is evenly arranged along the circumference at the corresponding position of the threaded holes on the lower surface of the outer cylinder to achieve bolt connection with the outer cylinder. The viscoelastic damping element 5 mainly undergoes shear and tensile deformation, and can provide additional damping and recovery stiffness for the buffer mechanism.

[0052] The force transmission element 4 is located at the bottom of the mesh buffer element 6, and is mainly divided into three parts: the first force transmission plate 4-1, the connecting rod 4-2 and the second force transmission plate 4-3. The first force transmission plate 4-1 is located at the upper end of the force transmission element, and is used to compress the mesh buffer element 6. Its diameter is 1~2mm smaller than the inner diameter of the outer cylinder to achieve sliding connection with the outer cylinder; the second force transmission plate 4-3 is located at the lower end of the force transmission element, and is used to drive the viscoelastic damping element 5 to deform. Its diameter is 3~4 times the diameter of the central circular hole of the viscoelastic damping element 5; the connecting rod 4-2 is located between the first force transmission plate 4-1 and the second force transmission plate 4-3. After passing through the central circular hole of the viscoelastic damping element 5, it is respectively fixed to the first force transmission plate 4-1 and the second force transmission plate 4-2.

[0053] The bottom end of the outer cylinder 1 is closed by the lower cover plate 3 and the viscoelastic damping element 5. The upper surface of the lower cover plate 3 is in close contact with the viscoelastic damping element 5. A plurality of countersunk holes are evenly arranged along the circumference of the outer edge thereof. The positions of the countersunk holes correspond one to one with the circular holes on the outer edge of the viscoelastic damping element 5. The high-strength bolts 7 pass through the countersunk holes of the lower cover plate 3, the circular holes of the viscoelastic damping element 5 and the threaded holes on the lower surface of the outer cylinder 1 in sequence, so as to realize the fixed connection among the outer cylinder 1, the viscoelastic damping element 5 and the lower cover plate 3.

[0054] A circular hole is opened at the center position of the lower cover plate 3. The upper end of the push rod 9 extends into the inner cavity of the outer tube 1 through the hole and is fixed to the force transmission element 4. The lower end of the push rod 9 is connected to the foot pad 10 through a ball joint. Using the ball joint, the buffer mechanism can be adjusted to a suitable angle according to the landing leg structure of the probe.

[0055] A buffering method of a recoverable landing buffer mechanism of a lunar probe according to an embodiment of the present invention is:

[0056] Before the lunar probe lands, it will adjust its landing attitude when it is close to the lunar surface, so that the upper probe remains stable and the landing legs form a suitable angle with the lunar surface. Then, the braking rocket will be turned off and the landing will be carried out.

[0057] The recoverable landing buffer mechanism is located at the bottom of the probe landing leg, and its top is connected to the landing leg. During the probe landing process, the lower foot pad first impacts the lunar surface, and then pushes the push rod and the upper force transmission element to move upward in the inner cavity of the outer cylinder, compressing the mesh buffer element above the force transmission element. There is friction between the metal wires of the mesh buffer element and between the metal wires and the surrounding powder damping materials, which will consume a lot of impact energy. At the same time, as the force transmission element moves upward, the viscoelastic damping element will also be stretched and deformed, which can play an energy dissipation role. Under the joint action of the three energy dissipation mechanisms, the impact on the upper probe will be significantly reduced, and the probe can achieve a smooth landing;

[0058] After the landing is completed, both the net-shaped buffer element and the viscoelastic damping element of the recoverable landing buffer mechanism will store part of the potential energy, and they jointly provide the bearing function for the upper detector. Since the net-shaped buffer element and the viscoelastic damping element are always in the elastic working state during the landing process, when the detector takes off again, the potential energy stored by the two will be slowly released and the deformation will gradually recover. Among them, the viscoelastic damping element has a strong self-resetting ability and will drive the push rod and the foot pad to move downward as a whole. The net-shaped buffer element will gradually expand downward following the force transmission element. Since both of them have the characteristics of high damping, the deformation recovery process is relatively stable and will not affect the upper detector. Finally, both of them will return to the initial state, and the landing buffer mechanism has the ability of repeated buffering;

[0059] When the impact force on the detector is small, the mechanism will dissipate a large amount of impact energy through the shear deformation of the viscoelastic damping element. At this time, although the net-shaped buffer element is difficult to deform fully, the mechanism still has excellent buffering ability and the characteristics of repeated buffering;

[0060] When the detector is subjected to a strong impact force in extreme cases, as the compression amount of the net-shaped buffer element increases, the restraint effect of the outer cylinder on it increases. At the same time, as the tensile amount of the viscoelastic damping element becomes larger, its stiffness also gradually increases. The mechanism shows the characteristics of flexible self-limitation, which can effectively limit the continuous increase of the mechanism deformation and protect the upper detector from being damaged.

Claims

1. A lunar probe recoverable landing buffer mechanism, comprising: The outer cylinder is a cylindrical cylinder with openings at both ends, an upper cover plate is arranged at the upper end to form a closed end, and the lower end is spliced with a lower cover plate with a central circular hole; the top of the upper cover plate is connected to the main part of the aircraft; A push rod extends upward from the central circular hole of the lower cover plate into the inner cavity of the outer cylinder, wherein the lower end of the push rod is hinged to a foot pad, and the upper end of the push rod is fixed to a force transmission element; A mesh buffer element filled in the inner cavity of the outer cylinder and located between the lower surface of the upper cover plate and the force transmission element; Powder damping material is filled in the gap between the mesh buffer element and the inner cavity of the outer cylinder to enhance the energy dissipation capacity of the mesh buffer element; The viscoelastic damping element is a viscoelastic sheet with a central opening, located between the bottom end of the outer cylinder and the lower cover plate, and its edge is fixed to the lower end of the outer cylinder and the upper end of the lower cover plate; The force transmission element comprises a first force transmission plate, a connecting rod, and a second force transmission plate arranged on the same axis, wherein the first force transmission plate is located above the viscoelastic damping element, and the top surface is in close contact with the mesh buffer element; The second force transmission plate is located below the viscoelastic damping element, and the bottom surface is fixed to the push rod; After the connecting rod passes through the central circular hole of the viscoelastic damping element, the upper end of the connecting rod is fixed to the first force transmission plate, and the lower end of the connecting rod is fixed to the second force transmission plate; When the probe lands, the mesh buffer element undergoes compression deformation, and the viscoelastic damping element undergoes tension or shear deformation, consuming and storing part of the energy; The mesh buffer element is made of high-strength, high-toughness and stable-performance metal wires that are stretched and curled into micro springs, 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, and the mesh buffer element completely recovers its original shape after compression deformation; The viscoelastic damping element is mechanically connected to the outer cylinder and the lower cover plate through bolts.

2. The recoverable landing buffer mechanism of a lunar probe according to claim 1, 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.

3. The recoverable landing buffer mechanism of a lunar probe according to claim 1, characterized in that, The powder damping material is high-purity carbon powder or silicon powder; The viscoelastic damping element is made of high dissipation viscoelastic material, with a thickness of 1 / 5 to 1 / 7 of the diameter. It undergoes shear deformation when the deformation is small and tensile deformation when the deformation is large.

4. A recoverable landing buffer mechanism for a lunar probe according to claim 1, characterized in that, The lower end of the outer cylinder is evenly provided with a plurality of threaded holes along the circumferential direction; A plurality of circular holes are evenly arranged along the circumferential direction on the outer edge of the viscoelastic damping element, the number of the circular holes is equal to the number of the threaded holes, and the positions of the circular holes correspond to the threaded holes; A plurality of countersunk holes are evenly arranged along the circumferential direction on the outer edge of the lower cover plate, and the number of the countersunk holes is equal to the number of the threaded holes and the circular holes, and the positions thereof correspond; At each countersunk hole position on the edge of the lower cover plate, multiple high-strength bolts are passed through the countersunk holes and round holes in sequence and then screwed into the threaded holes at the lower end of the outer cylinder to achieve a fixed connection between the outer cylinder, the viscoelastic damping element and the lower cover plate.

5. A recoverable landing buffer mechanism for a lunar probe according to claim 1, characterized in that, In the force transmission element, the diameter of the first force transmission plate is 2-3 mm smaller than the inner diameter of the outer cylinder, and a sliding connection is achieved between the first force transmission plate and the outer cylinder, and a sufficient contact area is provided between the first force transmission plate and the mesh buffer element; The diameter of the connecting rod is equal to the diameter of the central circular hole of the viscoelastic damping element and is in close contact with the inner wall of the central circular hole of the viscoelastic damping element; The diameter of the second force transmission plate is 3 to 4 times the diameter of the central circular hole of the viscoelastic damping element, ensuring that the viscoelastic damping element and the force transmission element do not separate during the deformation process.

6. The recoverable landing buffer mechanism of a lunar probe according to claim 1, characterized in that, The side surface of the mesh buffer element contacts the inner wall of the outer cylinder, and the outer cylinder provides lateral restraint for the mesh buffer element to enhance the damping of the mesh buffer element.

7. A recoverable landing buffer mechanism for a lunar probe according to claim 1, characterized in that, The ultimate compression amount of the mesh buffer element and the ultimate tensile amount of the viscoelastic damping element are greater than the maximum buffer stroke of the mechanism.

8. A buffering method for a recoverable landing buffering mechanism of a lunar probe according to any one of claims 1 to 7, characterized in that Before the lunar probe lands, the landing attitude is adjusted near the lunar surface to keep the upper probe stable and form an appropriate angle between the landing legs and the lunar surface. Then, the braking rocket is turned off for landing. The recoverable landing buffering mechanism is located at the bottom of the landing leg of the probe, and its top is connected to the landing leg. During the landing process of the probe, the lower footpad first impacts the lunar surface, and then pushes the push rod and the upper force transmission element to move upward in the inner cavity of the outer cylinder, compressing the mesh buffer element above the force transmission element. There is friction between the metal wires of the mesh buffer element and between the metal wires and the surrounding powder damping material, which will consume a large amount of impact energy. At the same time, as the force transmission element moves upward, the viscoelastic damping element will also undergo tensile deformation and can play an energy dissipation role. Under the combined action of the three energy dissipation mechanisms, the impact on the upper probe will be significantly reduced, and the probe can achieve a smooth landing. After the landing is completed, the mesh buffer element and the viscoelastic damping element of the recoverable landing buffering mechanism will store part of the potential energy, and both jointly provide the bearing function for the upper probe. Since the mesh buffer element and the viscoelastic damping element are always in the elastic working state during the landing process, when the probe takes off again, the potential energy stored by both will be slowly released and the deformation will gradually recover. Among them, the viscoelastic damping element has a strong self-resetting ability and will drive the push rod and the footpad to move downward as a whole. The mesh buffer element will gradually expand downward following the force transmission element. Since both have the characteristics of high damping, the deformation recovery process is relatively smooth and will not affect the upper probe. Finally, both will return to the initial state, and the landing buffering mechanism has the ability to repeat buffering. When the impact on the probe is small, the mechanism will dissipate a large amount of impact energy through the shear deformation of the viscoelastic damping element. At this time, although the mesh buffer element is difficult to deform fully, the mechanism still has excellent buffering ability and the characteristics of repeatable buffering. When the probe is subjected to a strong impact in extreme cases, as the compression amount of the mesh buffer element increases, the restraint effect of the outer cylinder on it increases. At the same time, as the tensile amount of the viscoelastic damping element becomes larger, its stiffness also gradually increases. The mechanism exhibits the characteristics of flexible self-limitation, which can effectively limit the continuous increase of the mechanism's deformation and protect the upper probe from being damaged.

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