Oil-gas isolation type stable buffer for undercarriage and use method of oil-gas isolation type stable buffer

Abstract

The invention discloses an oil-gas isolation type stable buffer for an undercarriage and a using method, the oil-gas isolation type stable buffer comprises an earring bolt, a piston rod, an outer cylinder, a moving cylinder, a stop cover, a movable floating plug and an oil guide channel, the outer cylinder is provided with a front end cover and a rear end cover, and the moving cylinder and the movable floating plug are both arranged in the outer cylinder; a first air cavity is formed between the moving cylinder and the movable floating plug, a compression stroke hydraulic cavity is formed between the movable floating plug and the rear end cover, the stop cover is installed at the front end of the moving cylinder and located in the outer cylinder, and the piston rod penetrates through the front end cover and the stop cover to be connected with the moving cylinder. A stretching stroke hydraulic cavity is formed among the piston rod, the stop cover and the moving cylinder; the compression stroke hydraulic cavity is communicated with the stretching stroke hydraulic cavity through an oil guide channel; the earring bolt is arranged at the front end of the piston rod and forms a second air cavity with an inner cavity of the piston rod. By the adoption of the buffer and the using method, an oil-gas isolation type structure is adopted, and the buffer not only has adjustable damping, but also has the two-way buffering function of stretching and compressing.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation landing gear, in particular to an oil-gas isolation type stabilizing buffer for landing gear and a use method thereof. Background Art

[0002] Hydraulic buffers mainly realize two functions: buffering and resetting. When a high-speed object suddenly hits the buffer, the object is controlled to slow down through its throttling and energy storage, and the running object is gradually stopped and reset. At present, most aircraft landing gears use oil-gas buffers. The internal design of oil-gas buffers has been improved and developed. In order to improve the energy absorption capacity of the landing gear buffer and reduce the dynamic load during landing, especially ground taxiing and operation of the landing gear, single-stage double-chamber buffers are currently commonly used (that is, there are two air chambers, low pressure and high pressure, in one buffer), and a spring-controlled throttle valve is added to the buffer strut piston of the double-chamber device so that the valve will be opened at a given load, thereby improving the buffering performance of the buffer strut.

[0003] Since the frame-type landing gear stabilizing buffer is set between the frame and the buffer pillar, it is an essential functional component of modern landing gear. The stabilizing buffer can make the aircraft frame posture uniquely controllable after taking off and before landing, and absorb the impact energy of the aircraft wheel group swinging up and down around its axis during takeoff, landing and ground taxiing. However, the existing frame-type landing gear stabilizing buffer is generally a spring structure type or an oil-gas hybrid type. The spring structure stabilizing buffer can only buffer in one direction, and its damping effect will decay, resulting in a short fatigue life. The oil-gas hybrid stabilizing buffer is prone to cavitation, which leads to the generation of bubbles, making the damping performance unstable.

[0004] After searching, the patent document with the authorization announcement number CN206889552U discloses a new oil-gas hybrid buffer, and the patent document with the application publication number CN106352005A discloses an oil-gas separation buffer and its exhaust method. From the contents disclosed in the two retrieved patent documents, a buffer that meets the use requirements is provided from different angles. In order to avoid the problem that the spring structure one-way buffer will attenuate due to the damping effect, and the oil-gas hybrid buffer is prone to cavitation and bubbles, a buffer different from the prior art is provided to meet the use requirements. Summary of the invention

[0005] The technical problem to be solved by the present invention is to address the problems existing in the background technology, thereby providing a buffer with a simple structure and easy operation and use. The buffer can effectively solve the problems of one-way buffering and unstable damping performance, and the damping adjustable feature can be achieved through the damping valve provided on the outside of the buffer to meet more usage requirements. Specifically, it is an oil-gas isolated stable buffer for landing gear.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an oil-gas isolation type stabilizing buffer for landing gear, comprising an earring bolt, a piston rod, an outer cylinder, a floating cylinder, a stop cover, a movable float and an oil guide channel, the front end of the outer cylinder is provided with a front end cover, the rear end is provided with a rear end cover, the floating cylinder and the movable float are both arranged in the outer cylinder, and the movable float is located between the floating cylinder and the rear end cover, a first air cavity is formed between the floating cylinder and the movable float, a compression stroke hydraulic cavity is formed between the movable float and the rear end cover, the floating cylinder and The movable floats are all configured as cylindrical structures with one end open, and the piston rod is configured as a cylindrical structure with both ends open, the stop cover is installed at the front end of the floating cylinder and is located in the outer cylinder, the rear end of the piston rod passes through the front end cover and the stop cover in sequence and is connected to the floating cylinder, a stretching stroke hydraulic cavity is formed between the piston rod, the stop cover and the floating cylinder; the compression stroke hydraulic cavity is connected to the stretching stroke hydraulic cavity through an oil guide channel; the earring bolt is arranged at the front end of the piston rod, and a second air cavity communicating with the outside is formed between the earring bolt and the inner cavity of the piston rod.

[0007] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in the present invention is adopted, and an expansion ring is also provided on the inner wall surface of the outer cylinder, and a limiting groove corresponding to the expansion ring is provided on the outer wall surface of the rear end of the swimming cylinder, the expansion ring is arranged in the limiting groove, the rear end of the swimming cylinder is slidably connected to the inner wall surface of the outer cylinder through the expansion ring, and the front end of the swimming cylinder is slidably connected to the inner wall surface of the outer cylinder; the movable floating plug is slidably connected to the inner wall surface of the outer cylinder.

[0008] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in the present invention is adopted, wherein an inflation hole, a first oil filling hole and a first oil draining hole are provided on the outer cylinder, the first oil filling hole and the first oil draining hole are arranged in a ring shape on the outer cylinder, the inflation hole is communicated with the first air cavity, and an inflation valve is provided at the inflation hole; a first oil receiving groove corresponding to the first oil filling hole and the first oil draining hole, and a first channel communicated with the first oil receiving groove are provided in the movable cylinder, a second oil receiving groove corresponding to the first channel is provided in the rear end face of the front end cover, a second channel communicated with the stretching stroke hydraulic cavity is provided in the stop cover, and a first plug is provided at the first oil filling hole; the oil guide channel is communicated with the stretching stroke hydraulic cavity through the first oil draining hole.

[0009] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in the present invention is adopted, and a second oil filling hole and a second oil drain hole, as well as a third channel communicated with the compression stroke hydraulic chamber are provided on the rear end cover at the rear end of the outer tube, the second oil filling hole and the second oil drain hole are arranged in a ring shape on the rear end cover, the second oil filling hole and the second oil drain hole are respectively communicated with the third channel, and a second plug is provided at the second oil filling hole; the oil guide channel is communicated with the compression stroke hydraulic chamber through the second oil drain hole.

[0010] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in the present invention is adopted, wherein the oil guide channel includes a conduit, an outer tube nozzle, an end cover nozzle, a damping valve, a pipe joint and a supporting connecting rod, the outer tube nozzle is installed at the first oil drain hole in the outer tube, and the end cover nozzle is installed at the second oil drain hole in the rear end cover, the outer tube nozzle and the end cover nozzle are connected to the conduit via a pipe joint; the supporting connecting rod is arranged on the outer side surface of the outer tube, the damping valve is installed in the supporting connecting rod, and the damping valve is connected to the conduit via a pipe joint.

[0011] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in the present invention is adopted, the earring bolt includes a connecting portion and a barrel portion, the earring bolt forms an integral structure through the connecting portion and the barrel portion, the barrel portion is arranged as a cylindrical structure with one end open, the earring bolt is screwed into the piston rod through the barrel portion, and a nut abutting against the piston rod is also screwed on the outer wall of the barrel portion; an air intake passage communicating with the second air cavity is also arranged in the barrel portion, a limiting locking block is also arranged at the front end of the piston rod, and a fuse is arranged between the nut and the limiting locking block, and the nut is limited and prevented from loosening between the nut and the limiting locking block by the fuse.

[0012] Furthermore, the oil-gas isolation type stabilizing buffer for landing gear described in the present invention is adopted, and sealing grooves are respectively provided on the outer wall surfaces of the front end cover, the floating cylinder, the movable float and the piston rod, and the inner wall surfaces of the front end cover and the rear end cover, and sealing members are arranged in the sealing grooves, the floating cylinder and the movable float are slidably connected to the inner wall surface of the outer cylinder through the sealing members; and the piston rod is slidably connected to the front end cover and the inner wall surface of the floating cylinder through the sealing members.

[0013] Furthermore, in the oil-gas isolation type stabilizer for landing gear of the present invention, an adjustment washer is also provided at the rear end of the outer tube, the rear end cover is connected to the outer tube through the adjustment washer, the tail of the rear end cover is a single ear part, the single ear part in the rear end cover is also provided with a second connection hole, and a joint bearing is provided at the second connection hole; and the front end of the earring bolt is a double ear part, the double ear part in the earring bolt is provided with a first connection hole, and a bushing is provided at the first connection hole. A limiting protrusion is also provided on the outer side of the outer tube, the limiting protrusion is provided on the outer tube near the side of the rear end cover, and a fuse is arranged between the limiting protrusion and the rear end cover, and the limiting protrusion and the rear end cover are used to limit and prevent the rear end cover from loosening; and a limiting screw is also provided in the front end cover, and the front end cover is limited and prevented from loosening between the front end cover and the outer tube through the limiting screw.

[0014] The present invention also discloses a method for using the oil-gas isolation type stabilizing buffer for landing gear, the method comprising the following steps: S1. Before use, inject inert gas into the first gas cavity in advance, and inject hydraulic oil into the compression stroke hydraulic cavity and the stretch stroke hydraulic cavity; S2. When the buffer is in a neutral position, that is, the buffer is not subjected to an external load or the load is less than or equal to a set value, the buffer maintains a neutral position; S3. When the buffer is in the compression stroke state and is subjected to the load pressure Pa, the compression movement starts by using the compressive load, and the piston rod pushes the floating cylinder to compress the first air cavity, the volume of the first air cavity decreases, and the pressure increases. At the same time, during the movement of the floating cylinder, the volume of the stretching stroke hydraulic cavity increases, so that the movable float pushes the oil in the compression stroke hydraulic cavity through the damping valve in the oil guide channel and flows into the stretching stroke hydraulic cavity through the conduit, realizing the compression movement process, forming a buffer, and absorbing the energy generated by the compressive load; and when the compressive load disappears, the inert gas compressed in the first air cavity will expand, and the floating cylinder is used to push the hydraulic oil in the stretching stroke hydraulic cavity through the damping valve in the oil guide channel and flows into the compression stroke hydraulic cavity, and finally the buffer is restored to the neutral position; S4. When the buffer is in the stretching stroke state and is subjected to the load tension Pb, the stretching movement starts by utilizing the tensile load, and the piston rod pushes the oil in the stretching stroke hydraulic chamber through the damping valve in the oil guide channel and flows into the compression stroke hydraulic chamber through the conduit, thereby increasing the volume of the oil in the compression stroke hydraulic chamber, pushing the movable float to move, compressing the inert gas in the first air chamber, realizing the stretching movement process, forming a buffer, and absorbing the energy generated by the tensile load; when the tensile load disappears, the compressed inert gas in the first air chamber will expand, causing the movable float to push the hydraulic oil in the compression stroke hydraulic chamber, and flowing into the stretching stroke hydraulic chamber through the damping valve in the oil guide channel, thereby finally restoring the stabilizing buffer to its neutral position.

[0015] Furthermore, with the method of use described in the present invention, the inert gas is nitrogen, and the hydraulic oil is No. 15 aviation hydraulic oil. The injection amounts of the nitrogen and No. 15 aviation hydraulic oil require that the buffer remain in a neutral position when there is no external load. The neutral position refers to ensuring that the frame attitude is controllable after the aircraft takes off and before landing through the landing gear.

[0016] Compared with the prior art, the oil-gas isolation type stabilizing buffer and the use method for landing gear of the present invention have the following beneficial effects: the earring bolt, piston rod, outer cylinder, floating cylinder, stop cover, movable float and oil guide channel are configured, and the front cover and rear cover arranged at both ends of the outer cylinder are used to form four chambers, forming a structure with a vented air chamber, a middle air chamber and two-side interconnected hydraulic oil chambers, so that the stabilizing buffer can play a role in buffering and absorbing energy when subjected to tensile or compressive loads, and is always in a neutral fixed position when there is no external load. The neutral position can ensure that the frame posture is uniquely controllable after the aircraft takes off and before landing. By adopting the oil-gas isolation structure, no cavitation phenomenon occurs, so that the damping performance is stable, and the interconnecting channel between the two sides of the hydraulic oil chambers is designed on the outside, and the damping valve is connected through a conduit. When the compression and extension strokes are formed, the hydraulic oil flows through the damping valve, so that the damping of the buffer can be adjusted based on the adjustment of the external damping valve.

[0017] It can be seen that the stable buffer and the method of use described in the present invention adopt an oil-gas isolation structure and a double-actuation form, which not only has adjustable damping, but also has a bidirectional buffering function of tension and compression. The overall structure is simple and the design is reasonable. It can effectively avoid the influence of oil and gas mixing on the buffering performance, make the buffer work stably, have broad guiding significance for the buffer structure design, and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a structural schematic diagram of the present invention; Figure 3 The cross-sectional structure of the present invention is shown in FIG. Figure 1 ; Figure 4 The cross-sectional structure of the present invention is shown in FIG. Figure 2 ; Figure 5 It is a structural schematic diagram of the present invention when it is in a neutral position; Figure 6 It is a structural schematic diagram of the present invention when it is in a compression stroke state; Figure 7 It is a schematic diagram of the structure of the present invention when it is in a stretching stroke state.

[0020] As shown in the figure: 1-earring bolt, 101-nut, 102-intake channel, 103-bushing, 2-piston rod, 21-limit lock block, 3-outer cylinder, 31-limit convex block, 4-moving cylinder, 41-limit groove, 42-first oil receiving groove, 43-first channel, 5-stop cover, 51-second channel, 6-movable float, 7-oil guide channel, 71-conduit, 72-outer cylinder nozzle, 73-end cover nozzle, 74-damping movable Door, 75-pipe joint, 76-support connecting rod, 8-front end cover, 81-second oil receiving groove, 82-limit screw, 9-rear end cover, 91-third channel, 92-spherical bearing, 10-first air cavity, 11-compression stroke hydraulic cavity, 12-tension stroke hydraulic cavity, 13-second air cavity, 14-expansion ring, 15-inflatable valve, 16-first plug, 17-second plug, 18-sealing groove, 19-adjusting gasket. DETAILED DESCRIPTION

[0021] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0022] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", etc. quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] It should be noted that the term "comprise" or any other variation is intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus. Example 1

[0025] like Figures 1 to 4As shown, this embodiment provides an oil-gas isolation type stabilizing buffer for a landing gear, comprising an earring bolt 1, a piston rod 2, an outer cylinder 3, a floating cylinder 4, a stop cover 5, a movable float 6 and an oil guide channel 7. The front end of the outer cylinder 3 is provided with a front end cover 8, and the rear end is provided with a rear end cover 9. The floating cylinder 4 and the movable float 6 are both arranged in the outer cylinder 3, and the movable float 6 is located between the floating cylinder 4 and the rear end cover 9. A first air cavity 10 is formed between the floating cylinder 4 and the movable float 6, and a compression stroke hydraulic cavity 11 is formed between the movable float 6 and the rear end cover 9. The floating cylinder 4 and the movable float 6 are both arranged as a cylindrical structure with an opening at one end, and the piston rod 2 is arranged as a cylindrical structure with openings at both ends. The stop cover 5 is installed at the front end of the floating cylinder 4 and is located in the outer cylinder 3. The rear end of the piston rod 2 passes through the front end cover 8 and the stop cover 5 in sequence and is connected to the swimming cylinder 4. A stretching stroke hydraulic cavity 12 is formed between the piston rod 2 and the outer cylinder 3 and the swimming cylinder 4; the compression stroke hydraulic cavity 11 is connected to the stretching stroke hydraulic cavity 12 through the oil guide channel 7; the earring bolt 1 is arranged at the front end of the piston rod 2, and a second air cavity 13 communicating with the outside is formed between the earring bolt 1 and the inner cavity of the piston rod 2; the tail of the rear end cover 9 is a single-ear part, and a second connecting hole is also provided in the single-ear part of the rear end cover 9, and a joint bearing 92 is provided at the second connecting hole; and the front end of the earring bolt 1 is a double-ear part, and a first connecting hole is provided in the double-ear part of the earring bolt 1, and a bushing 103 is provided at the first connecting hole.

[0026] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in this embodiment is adopted, wherein an inflation hole, a first oil filling hole and a first oil drain hole are provided on the outer tube 3, the first oil filling hole and the first oil drain hole are arranged in a ring shape on the outer tube 3, the inflation hole is communicated with the first air cavity 10, and an inflation valve 15 is provided at the inflation hole; a first oil receiving groove 42 corresponding to the first oil filling hole and the first oil drain hole, and a first channel 43 communicated with the first oil receiving groove 42 are provided in the swimming cylinder 4, a second oil receiving groove 81 corresponding to the first channel 43 is provided in the rear end face of the front end cover 8, and a tensioning groove 81 corresponding to the tensioning groove 8 is provided in the stop cover 5. A second passage 51 communicated with the stretching stroke hydraulic chamber 12, and a first plug 16 is provided at the first oil filling hole; the oil guide passage 7 is communicated with the stretching stroke hydraulic chamber 12 through the first oil drain hole; at the same time, a second oil filling hole and a second oil drain hole are provided on the rear end cover 9 at the rear end of the outer tube 3, and a third passage 91 communicated with the compression stroke hydraulic chamber 11, the second oil filling hole and the second oil drain hole are arranged in a ring shape on the rear end cover 9, the second oil filling hole and the second oil drain hole are respectively communicated with the third passage 91, and a second plug 17 is provided at the second oil filling hole; the oil guide passage 7 is communicated with the compression stroke hydraulic chamber 11 through the second oil drain hole.

[0027] Furthermore, an oil-gas isolation stabilizer for a landing gear as described in this embodiment is adopted, wherein the oil guide channel 7 includes a conduit 71, an outer tube nozzle 72, an end cover nozzle 73 and a damping valve 74, wherein the outer tube nozzle 72 is installed at the first oil drain hole in the outer tube 3, and the end cover nozzle 73 is installed at the second oil drain hole in the rear end cover 9, the outer tube nozzle 72 and the end cover nozzle 73 are connected by a conduit 71, and a damping valve 74 is provided in the conduit 71.

[0028] Furthermore, an oil-gas isolated stabilizing buffer for a landing gear as described in this embodiment is adopted, and the oil guide channel 7 also includes a pipe joint 75 and a supporting connecting rod 76, and the conduit 71 is respectively connected to the outer tube nozzle 72 and the end cover nozzle 73 through the pipe joint 75; the supporting connecting rod 76 is arranged on the outer side of the outer tube 3, and the damping valve 74 is installed in the supporting connecting rod 76, and the damping valve 74 is connected to the conduit 71 through the pipe joint 75.

[0029] Furthermore, the oil-gas isolation type stabilizer for landing gear of the present invention is adopted, the earring bolt 1 includes a connecting portion and a barrel portion, the earring bolt forms an integral structure through the connecting portion and the barrel portion, the barrel portion is set as a cylindrical structure with one end open, the earring bolt is screwed into the piston rod 2 through the barrel portion, and a nut 101 that abuts against the piston rod 2 is also screwed on the outer wall of the barrel portion; an air intake channel 102 that communicates with the second air cavity 13 is also provided in the barrel portion. At the same time, a limiting lock block 21 is also provided at the front end of the piston rod 2, and a fuse is also arranged between the nut 101 and the limiting lock block 21, and the nut 102 is limited and prevented from loosening by the fuse between the nut 102 and the limiting lock block 21. In addition, a limiting protrusion 31 is provided on the outer side surface of the outer cylinder 3, and the limiting protrusion 31 is arranged on the outer cylinder 3 near the side of the rear end cover 9, and a fuse is arranged between the limiting protrusion 31 and the rear end cover 9, and the rear end cover 9 is limited and prevented from loosening by the limiting protrusion 31 and the rear end cover 9; and a limiting screw 82 is also provided in the front end cover 8, and the front end cover 8 is limited and prevented from loosening by the limiting screw 82 between the front end cover 8 and the outer cylinder 3. Example 2

[0030] This embodiment is based on the embodiment 1. In order to facilitate the sliding of the movable cylinder 4 in the outer cylinder 3 on the inner wall surface of the outer cylinder 3 and the sliding of the piston rod 2 on the inner wall surface of the movable cylinder 4, and at the same time, in order to achieve sealing, so that the first gas cavity 10, the compression stroke hydraulic cavity 11 and the extension stroke hydraulic cavity 12 form a closed structure, an oil-gas isolation type stabilizing buffer for a landing gear described in this embodiment is adopted, and an expansion ring 14 is also provided on the inner wall surface of the outer cylinder 3, and a limiting groove 41 corresponding to the expansion ring 14 is provided on the outer wall surface of the rear end of the movable cylinder 4, and the expansion ring 14 is arranged in the limiting groove 41. The rear end of the movable cylinder 4 is slidably connected to the inner wall surface of the outer cylinder 3 through the expansion ring 14, and its front end is slidably connected to the inner wall surface of the outer cylinder 3; the movable float 6 is slidably connected to the inner wall surface of the outer cylinder 3.

[0031] Furthermore, the oil-gas isolation stabilizer for landing gear described in this embodiment is adopted, and sealing grooves 18 are respectively provided on the outer wall surfaces of the front end cover 8, the floating cylinder 4, the movable float 6 and the piston rod 2, and the inner wall surfaces of the front end cover 8 and the rear end cover 9, and sealing members are arranged in the sealing grooves 18, and the floating cylinder 4 and the movable float 6 are slidably connected to the inner wall surface of the outer cylinder 3 through the sealing members; and the piston rod 2 is slidably connected to the inner wall surfaces of the front end cover 8 and the floating cylinder 4 through the sealing members. Example 3

[0032] like Figures 5 to 7 As shown, this embodiment discloses a method for using the oil-gas isolated stabilizer for landing gear, and the method comprises the following steps: S1. Before use, inert gas is injected into the first air cavity 10 in advance, and hydraulic oil is injected into the compression stroke hydraulic cavity 11 and the extension stroke hydraulic cavity 12 at the same time; wherein the inert gas is nitrogen, and the hydraulic oil is No. 15 aviation hydraulic oil, and the injection amount of the nitrogen and No. 15 aviation hydraulic oil requires that the buffer is kept in a neutral position when there is no external load, and the neutral position refers to the controllable frame posture after the aircraft takes off and before landing by the landing gear; S2. When the buffer is in the neutral position, its structure is as follows Figure 5 As shown, when the buffer is not subjected to external load or the load is less than or equal to the set value, the buffer maintains a neutral position; S3. When the buffer is in the compression stroke state, its structure is as follows Figure 6As shown, when the buffer is subjected to the load pressure Pa, the compression movement is started by using the compressive load, and the piston rod 2 pushes the floating cylinder 4 to compress the first gas cavity 10, the volume of the first gas cavity 10 is reduced, and the pressure is increased. At the same time, during the movement of the floating cylinder 4, the volume of the stretching stroke hydraulic cavity 12 is increased, so that the movable float 6 pushes the oil in the compression stroke hydraulic cavity 11 through the damping valve 74 in the oil guide channel 7, and flows into the stretching stroke hydraulic cavity 12 through the conduit 71, realizing the compression movement process, forming a buffer, and absorbing the energy generated by the compressive load; and when the compressive load disappears, the inert gas compressed in the first gas cavity 10 will expand, and the floating cylinder 4 is used to push the hydraulic oil in the stretching stroke hydraulic cavity 12 through the damping valve 74 in the oil guide channel 7 to flow into the compression stroke hydraulic cavity 11, and finally the buffer is restored to the neutral position; S4. When the buffer is in the stretching stroke state, its structure is as follows Figure 7 As shown, when the buffer is subjected to the load tension Pb, the tensile movement is started by utilizing the tensile load, and the piston rod 2 pushes the oil in the hydraulic chamber 12 of the tensile stroke to pass through the damping valve 74 in the oil guide channel 7, and flows to the hydraulic chamber 11 of the compression stroke through the conduit 71, thereby increasing the volume of the oil in the hydraulic chamber 11 of the compression stroke, pushing the movable float 6 to move, compressing the inert gas in the first gas chamber 10, realizing the tensile movement process, forming a buffer, and absorbing the energy generated by the tensile load; when the tensile load disappears, the compressed inert gas in the first gas chamber 10 will expand, so that the movable float 6 pushes the hydraulic oil in the hydraulic chamber 11 of the compression stroke to flow into the hydraulic chamber 12 of the tensile stroke through the damping valve 74 in the oil guide channel 7, and finally restores the stable buffer to the neutral position.

[0033] The oil-gas separation type stabilizing buffer for landing gear of the present invention can be designed to meet the use requirements of different landing gears in the specific design and preparation process. If the stabilizing buffer needs to be designed to be subjected to the same tensile / compressive load, that is, the tensile or compression stroke is also the same, it is only necessary to design the cross-sectional area of ​​the piston rod 2 to be equal to half of the cross-sectional area of ​​the outer circle of the piston end, that is, the cross-sectional area of ​​the piston rod 2 to be equal to half of the cross-sectional area of ​​the inner cavity of the floating cylinder 4.

[0034] It can be seen that the oil-gas isolation type stabilizing buffer and the method of use for landing gear of the present invention adopt an oil-gas isolation type structure, whose damping is adjustable, and has a bidirectional buffering function of tension and compression through a double-actuation form. The earring bolt 1, piston rod 2, outer cylinder 3, floating cylinder 4, stop cover 5, movable float 6 and oil guide channel 7, as well as the front cover 8 and rear cover 9 arranged at both ends of the outer cylinder 3, form a four-chamber structure, forming a structure with a vented air cavity, a middle air cavity and hydraulic oil cavities on both sides, so that the stabilizing buffer can play a role in buffering and absorbing energy when subjected to tensile or compressive loads, and is always in a neutral fixed position when there is no external load. The neutral position can ensure that the frame posture of the aircraft is kept uniquely controllable after leaving the ground and before landing. The oil-gas isolation type does not produce cavitation, and the damping performance is stable. The oil guide channel 7 that communicates between the hydraulic oil chambers on both sides is designed on the outside of the outer tube 3, and is connected to the damping valve 74 through the 71 conduit. When the compression / stretching stroke is formed, the hydraulic oil flows through the damping valve 74, so that the damping of the buffer can be adjusted based on adjusting the external damping valve 74.

[0035] In summary, the stable buffer and the method of use described in the present invention adopt an oil-gas isolation structure and a double-actuation form, which not only has adjustable damping, but also has a bidirectional buffering function of tension and compression. The overall structure is simple and the design is reasonable. It can effectively avoid the influence of oil and gas mixing on the buffering performance, make the buffer work stably, have broad guiding significance for the buffer structure design, and is suitable for promotion and application.

[0036] Other aspects of the present invention that are not described in detail are all conventional techniques known to those skilled in the art.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various changes and variations may occur. Any modifications, equivalent substitutions, improvements, etc. made using the present invention should be included in the scope of protection of the present invention.

Claims

1. An oil-gas isolated stabilizer for landing gear, characterized in that: The invention comprises an earring bolt (1), a piston rod (2), an outer cylinder (3), a movable cylinder (4), a stop cover (5), a movable float plug (6) and an oil guide passage (7). The front end of the outer cylinder (3) is provided with a front cover (8), and the rear end is provided with a rear cover (9). The movable cylinder (4) and the movable float plug (6) are both arranged in the outer cylinder (3), and the movable float plug (6) is located between the movable cylinder (4) and the rear cover (9). A first air cavity (10) is formed between the movable cylinder (4) and the movable float plug (6), and a compression stroke hydraulic cavity (11) is formed between the movable float plug (6) and the rear cover (9). The movable cylinder (4) and the movable float plug (6) are both arranged as cylindrical structures with one end open. The piston rod (2) is configured as a cylindrical structure with two ends open, the stop cover (5) is mounted on the front end of the floating cylinder (4) and is located inside the outer cylinder (3), the rear end of the piston rod (2) passes through the front end cover (8) and the stop cover (5) in sequence and is connected to the floating cylinder (4), a stretching stroke hydraulic cavity (12) is formed between the piston rod (2), the stop cover (5) and the floating cylinder (4); the compression stroke hydraulic cavity (11) is connected to the stretching stroke hydraulic cavity (12) via an oil guide channel (7); the earring bolt (1) is arranged at the front end of the piston rod (2), and a second air cavity (13) communicating with the outside is formed between the earring bolt (1) and the inner cavity of the piston rod (2).

2. The oil-gas isolation stabilizer for landing gear according to claim 1, characterized in that: An expansion ring (14) is also provided on the inner wall surface of the outer cylinder (3), and a limiting groove (41) corresponding to the expansion ring (14) is provided on the outer wall surface of the rear end of the movable cylinder (4). The expansion ring (14) is arranged in the limiting groove (41). The rear end of the movable cylinder (4) is slidably connected to the inner wall surface of the outer cylinder (3) through the expansion ring (14), and the front end of the movable cylinder (4) is slidably connected to the inner wall surface of the outer cylinder (3); the movable float (6) is slidably connected to the inner wall surface of the outer cylinder (3).

3. The oil-gas isolation stabilizer for landing gear according to claim 2, characterized in that: The outer cylinder (3) is provided with an air filling hole, a first oil filling hole and a first oil drain hole. The first oil filling hole and the first oil drain hole are arranged in a ring shape on the outer cylinder (3). The air filling hole is communicated with the first air cavity (10), and an air filling valve (15) is provided at the air filling hole. The movable cylinder (4) is provided with a first oil receiving groove (42) corresponding to the first oil filling hole and the first oil drain hole, and a first channel (43) communicated with the first oil receiving groove (42). The rear end surface of the front end cover (8) is provided with a second oil receiving groove (81) corresponding to the first channel (43). The stop cover (5) is provided with a second channel (51) communicated with the stretching stroke hydraulic cavity (12), and a first plug (16) is provided at the first oil filling hole. The oil guide channel (7) is communicated with the stretching stroke hydraulic cavity (12) through the first oil drain hole.

4. The oil-gas isolation stabilizer for landing gear according to claim 3, characterized in that: A second oil injection hole and a second oil discharge hole, and a third passage (91) communicating with the compression stroke hydraulic chamber (11) are provided on the rear end cover (9) at the rear end of the outer cylinder (3); the second oil injection hole and the second oil discharge hole are arranged in a ring shape on the rear end cover (9); the second oil injection hole and the second oil discharge hole are respectively communicated with the third passage (91); and a second plug (17) is provided at the second oil injection hole; the oil guide passage (7) is communicated with the compression stroke hydraulic chamber (11) through the second oil discharge hole.

5. The oil-gas isolation stabilizer for landing gear according to claim 4, characterized in that: The oil guide passage (7) comprises a guide tube (71), an outer tube nozzle (72), an end cover nozzle (73), a damping valve (74), a pipe joint (75) and a supporting connecting rod (76); the outer tube nozzle (72) is installed at a first oil discharge hole in the outer tube (3), and the end cover nozzle (73) is installed at a second oil discharge hole in the rear end cover (9); the outer tube nozzle (72) and the end cover nozzle (73) are connected to the guide tube (71) via a pipe joint (75); the supporting connecting rod (76) is arranged on the outer side of the outer tube (3), the damping valve (74) is installed in the supporting connecting rod (76), and the damping valve (74) is connected to the guide tube (71) via a pipe joint (75).

6. The oil-gas isolation stabilizer for landing gear according to claim 5, characterized in that: The earring bolt (1) comprises a connecting portion and a barrel portion, wherein the earring bolt forms an integral structure through the connecting portion and the barrel portion, wherein the barrel portion is a cylindrical structure with one end open, wherein the earring bolt is screwed into the piston rod (2) through the barrel portion, and a nut (101) abutting against the piston rod (2) is also screwed on the outer wall of the barrel portion; an air inlet passage (102) communicating with the second air cavity (13) is also provided in the barrel portion; a limiting locking block (21) is also provided at the front end of the piston rod (2), and a fuse is arranged between the nut (101) and the limiting locking block (21), and the nut (102) is limited and prevented from loosening by the fuse between the nut (102) and the limiting locking block (21).

7. The oil-gas isolation stabilizer for landing gear according to claim 6, characterized in that: Sealing grooves (18) are respectively provided on the outer wall surfaces of the front end cover (8), the movable cylinder (4), the movable float (6) and the piston rod (2), and the inner wall surfaces of the front end cover (8) and the rear end cover (9), and sealing members are arranged in the sealing grooves (18). The movable cylinder (4) and the movable float (6) are slidably connected to the inner wall surface of the outer cylinder (3) through the sealing members in the sealing grooves (18); and the piston rod (2) is slidably connected to the inner wall surface of the front end cover (8) and the movable cylinder (4) through the sealing members in the sealing grooves (18).

8. The oil-gas isolation stabilizer for landing gear according to claim 7, characterized in that: An adjusting washer (19) is also provided at the rear end of the outer cylinder (3), and the rear end cover (9) is connected to the outer cylinder (3) via the adjusting washer (19); the tail of the rear end cover (9) is a single-ear portion, and a second connecting hole is also provided in the single-ear portion of the rear end cover (9), and a joint bearing (92) is provided at the second connecting hole; the front end of the earring bolt (1) is a double-ear portion, and a first connecting hole is provided in the double-ear portion of the earring bolt (1), and a bushing (103) is provided at the first connecting hole; 3) A limiting protrusion (31) is also provided on the outer surface, and the limiting protrusion (31) is arranged on the outer tube (3) on the side close to the rear end cover (9), and a fuse is arranged between the limiting protrusion (31) and the rear end cover (9), and the rear end cover (9) is limited and prevented from loosening by the limiting protrusion (31) and the rear end cover (9); and a limiting screw (82) is also provided in the front end cover (8), and the front end cover (8) is limited and prevented from loosening by the limiting screw (82) between the front end cover (8) and the outer tube (3).

9. A method for using the oil-gas isolated stabilizer for landing gear according to any one of claims 1 to 8, characterized in that: The method of use comprises the following steps: S1. Before use, an inert gas is injected into the first gas cavity (10) in advance, and hydraulic oil is injected into the compression stroke hydraulic cavity (11) and the stretch stroke hydraulic cavity (12); S2. When the buffer is in a neutral position, that is, the buffer is not subjected to an external load or the load is less than or equal to a set value, the buffer maintains a neutral position; S3. When the buffer is in the compression stroke state and is subjected to the load pressure Pa, the buffer starts to work by means of the compressive load, and the piston rod (2) pushes the floating cylinder (4) to compress the first gas cavity (10), the volume of the first gas cavity (10) decreases, and the pressure increases. At the same time, during the movement of the floating cylinder (4), the volume of the stretching stroke hydraulic cavity (12) increases, so that the movable float (6) pushes the oil in the compression stroke hydraulic cavity (11) through the damping valve (74) in the oil guide channel (7), and flows into the stretching stroke hydraulic cavity (12) through the conduit (71), thereby realizing the compression movement process, forming a buffer, and absorbing the energy generated by the compressive load; and when the compressive load disappears, the inert gas compressed in the first gas cavity (10) expands, and the floating cylinder (4) is used to push the hydraulic oil in the stretching stroke hydraulic cavity (12) through the damping valve (74) in the oil guide channel (7) and flows into the compression stroke hydraulic cavity (11), and finally the buffer is restored to the neutral position; S4. When the buffer is in the stretching stroke state and is subjected to the load tension Pb, the stretching movement is started by utilizing the tensile load. The piston rod (2) pushes the oil in the stretching stroke hydraulic chamber (12) through the damping valve (74) in the oil guide channel (7) and flows into the compression stroke hydraulic chamber (11) through the conduit (71), thereby increasing the volume of the oil in the compression stroke hydraulic chamber (11), pushing the movable float (6) to move, compressing the inert gas in the first gas chamber (10), realizing the stretching movement process, forming a buffer, and absorbing the energy generated by the tensile load; when the tensile load disappears, the compressed inert gas in the first gas chamber (10) expands, causing the movable float (6) to push the hydraulic oil in the compression stroke hydraulic chamber (11) through the damping valve (74) in the oil guide channel (7) and flow into the stretching stroke hydraulic chamber (12), thereby finally restoring the stable buffer to a neutral position.

10. The method of use according to claim 9, characterized in that: The inert gas is nitrogen, and the hydraulic oil is No. 15 aviation hydraulic oil. The injection amounts of the nitrogen and No. 15 aviation hydraulic oil require that the buffer remain in a neutral position when there is no external load. The neutral position ensures that the frame attitude remains controllable after the aircraft takes off and before landing through the landing gear.

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