CN111609073A

CN111609073A - Aircraft landing gear buffer

Info

Publication number: CN111609073A
Application number: CN202010490102.1A
Authority: CN
Inventors: 聂文忠; 陆建民; 马亚健; 陈晓东
Original assignee: Shanghai Institute of Technology
Current assignee: Shanghai Institute of Technology
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2020-09-01
Anticipated expiration: 2040-06-02
Also published as: CN111609073B

Abstract

The invention discloses an aircraft landing gear buffer, which comprises: an outer cylinder; the inner cylinder is movably arranged in the outer cylinder, a first cavity and a second cavity with the volume changing along with the movement of the inner cylinder are arranged between the inner cylinder and the outer cylinder, a third cavity is arranged in the inner cylinder, at least one first damping hole is arranged between the first cavity and the second cavity, at least one second damping hole is arranged between the second cavity and the third cavity, the second cavity is provided with buffer gas, and the third cavity is provided with buffer solution; the piston assembly is arranged in the third cavity; one end of the moving component is connected with the piston component through an elastic component, and the other end of the moving component extends out of the outer cylinder and is connected with the impacted component; the moving assembly moves upwards to compress the elastic piece to generate elastic force so as to perform first-stage buffering; the piston assembly moves the compressed buffer solution upwards to perform second-stage buffering; the inner cylinder moves the compressed buffer gas upward to perform a third stage of buffering. The buffer has three-level buffering, one-level or multi-level buffering is automatically selected according to the size of the received impact load, and larger impact can be absorbed and smaller vibration can be filtered.

Description

Aircraft landing gear buffer

Technical Field

The invention belongs to the technical field of aircraft landing gears, and particularly relates to an aircraft landing gear buffer.

Background

Landing gear is an attachment device for supporting an aircraft during takeoff, landing and taxiing on the ground at the lower portion of the aircraft. The landing gear buffer is used for buffering impact caused by taking off and landing or moving of an airplane, particularly when the airplane lands, the ground generates large impact force on the airplane body through the landing gear, and the airplane bumps due to unevenness of the ground to generate vibration, so that the structure and flight safety of the airplane are very unfavorable, and the landing gear buffer is arranged to have a good protection effect on the whole structure of the airplane.

The current buffers applied to the main landing gear and the nose landing gear of the airplane are mostly oil-gas buffers and elastic piece buffers. The oil-gas type buffer buffers through oil pressure and buffer gas compression, and the elastic piece buffer buffers through elastic piece force.

They all have some disadvantages when operated alone. The common oil-gas type buffer has low buffering efficiency, is difficult to effectively absorb small vibration, and has a short buffering stroke, so that passengers feel uncomfortable due to the buffering effect; the elastic piece buffer mainly absorbs energy by means of elastic deformation, the heat consumption effect of the elastic piece is small, and the heat consumption effect is increased by installing a friction gasket on the inner cylinder.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide an aircraft landing gear bumper having three levels of cushioning, wherein one or more levels of cushioning are automatically selected according to the magnitude of the impact load, so that a large impact or a small vibration can be filtered.

In order to achieve the purpose, the technical scheme of the invention is as follows:

an aircraft landing gear bumper comprising:

an outer cylinder;

the inner cylinder is movably arranged in the outer cylinder, a first cavity and a second cavity are arranged between the inner cylinder and the outer cylinder, the volume of the first cavity and the volume of the second cavity are changed along with the movement of the inner cylinder, a third cavity is arranged inside the inner cylinder, at least one communicated first damping hole is arranged between the first cavity and the second cavity, at least one communicated second damping hole is arranged between the second cavity and the third cavity, the second cavity is provided with buffer gas, and the third cavity is provided with buffer solution;

the piston assembly is arranged in the third cavity;

one end of the moving component is connected with the piston component through an elastic piece, and the other end of the moving component extends out of the outer cylinder and is connected with the impacted component;

when the impacted part is impacted, the moving assembly moves upwards to compress the elastic piece to generate elastic force so as to perform first-stage buffering; when the elastic force is larger than the hydraulic pressure and the self gravity applied to the piston assembly, the piston assembly moves upwards to compress the buffer solution to perform second-stage buffering, and the buffer solution flows through the second damping hole to dissipate impact energy and enters the second cavity; when the hydraulic pressure is greater than the air pressure and the self gravity of the inner cylinder, the inner cylinder moves upwards to compress the buffer air to perform third-stage buffering, the volume of the first cavity is increased, the volume of the second cavity is reduced, and the buffer liquid flows through the first damping hole under the action of the air pressure to dissipate impact energy and enters the first cavity.

According to an embodiment of the invention:

the inner wall of the outer cylinder is provided with a first flange which is in sliding sealing fit with the outer wall of the inner cylinder;

the outer wall of the inner barrel is provided with a second flange which is in sliding sealing fit with the inner wall of the outer barrel, and the second flange is positioned above the first flange;

the first cavity is located between the inner wall of the outer barrel, the outer wall of the inner barrel, the first flange and the second flange;

the second cavity is positioned above the upper end surface of the inner cylinder and consists of the upper end surface of the inner cylinder and the inner wall of the outer cylinder.

According to an embodiment of the present invention, the first orifice is disposed in the second flange.

According to an embodiment of the invention, the damping device comprises a hollow plunger, the plunger is arranged in the second cavity, the upper end of the plunger is connected with the upper end of the outer cylinder, the lower end of the plunger extends into the third cavity and is in sliding sealing fit with the wall of the third cavity, a plurality of first through holes communicating the interior of the plunger with the second cavity are formed in the circumferential surface of the plunger, and a second damping hole communicating the interior of the plunger with the third cavity is formed in the lower end of the plunger.

According to an embodiment of the invention, the lower end of the plunger is provided with a damping valve assembly, the damping valve assembly is provided with at least one normally open second damping hole and at least one normally closed second damping hole, and the normally closed second damping hole is opened when the buffer liquid pressure in the third cavity is greater than the damping valve assembly threshold value.

According to an embodiment of the present invention, at least one second damping hole is disposed at an upper end of the third chamber.

According to an embodiment of the present invention, an inflation assembly is included, the inflation assembly comprising:

the sealing shaft sleeve is arranged at the upper end of the second cavity, the sealing shaft sleeve is fixedly connected to the inner wall of the outer barrel and forms a fifth cavity with the inner wall of the outer barrel, and the upper end of the plunger is arranged in the fifth cavity;

the inflation valve is arranged on the wall of the fifth cavity and communicated with the outside;

the inflation hole is formed in the upper end of the plunger and communicated with the fifth cavity and the inside of the plunger, and a first one-way valve is arranged in the inflation hole.

According to an embodiment of the invention, the piston assembly comprises a piston head and a piston rod, the inner cylinder is provided with a fourth cavity, the moving assembly is arranged in the fourth cavity, the third cavity is communicated with the fourth cavity through a second through hole, the moving assembly is provided with a sliding hole, the elastic member is a first spring, the piston head is arranged in the third cavity, the piston rod is arranged in the second through hole in a penetrating manner, one end of the piston rod is connected with the piston head, the other end of the piston rod is arranged in the sliding hole, the piston rod can slide in the sliding hole, and the first spring is sleeved on the piston rod and is positioned between the piston head and the moving assembly.

According to an embodiment of the present invention, the third chamber is provided with a limiting portion for limiting the upper limit of the piston assembly, and when the piston assembly moves to the limiting portion, the piston assembly drives the inner cylinder to move upward.

According to an embodiment of the present invention, the liquid injection device comprises a liquid injection assembly, wherein the liquid injection assembly comprises:

the sixth cavity is arranged on the inner cylinder, and a fourth through hole communicated with the second cavity is formed in the upper end of the sixth cavity;

a seventh cavity, wherein a third flange in sliding sealing fit with the outer wall of the inner cylinder is arranged on the inner wall of the outer cylinder, the third flange is positioned below the first flange, and the seventh cavity is formed by the inner wall of the outer cylinder, the outer wall of the inner cylinder, the first flange and the third flange;

the oil filling valve is arranged in the seventh cavity and communicated with the outside;

and the oil filling port is arranged between the sixth cavity and the seventh cavity and is provided with a second one-way valve.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects:

(1) in the embodiment of the invention, the outer cylinder, the inner cylinder, the first damping hole, the second damping hole, the piston assembly, the moving assembly and the elastic element are arranged, so that a three-level buffering effect is achieved, the shock absorption effect is good, the shock absorption process is stable, one-level or multi-level buffering is automatically selected according to the size of the impact load, and the large impact can be absorbed and the small vibration can be filtered.

(2) In the embodiment of the invention, the first cavity is formed by surrounding the inner wall of the outer cylinder, the outer wall of the inner cylinder, the first flange and the second flange, so that the volume of the first cavity is zero when the inner cylinder is positioned at the initial position, and when the inner cylinder is restored to the initial position after the third-stage buffering is finished, no buffer solution is remained in the first cavity, and the buffer solution completely acts through the first damping holes and the second damping holes to dissipate impact energy, so that the buffering effect is better, and the rebound phenomenon in the extension stroke can be effectively inhibited.

(3) In the embodiment of the invention, the upper end of the third cavity is provided with at least one second damping hole, under the condition that the designed flow of the buffer solution passing through all the second damping holes is not changed, the diameter of the second damping holes is reasonably reduced, the number of the second damping holes is increased, more impact energy can be dissipated, and the buffering effect is better.

(4) In the embodiment of the invention, the third cavity is provided with the limiting part for limiting the upper limit of the piston assembly, so that the piston assembly can be limited by the limiting part when the impact is large, the inner cylinder is prevented from being damaged, and the inner cylinder can be continuously pushed to move upwards by the limiting part.

Drawings

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings, in which:

FIG. 1 is a schematic view of an aircraft landing gear bumper of the present invention in an initial state;

FIG. 2 is a schematic view of an aircraft landing gear bumper of the present invention in a primary buffering state;

FIG. 3 is a schematic view of an aircraft landing gear bumper of the present invention in a secondary cushioning state;

FIG. 4 is a schematic view of an aircraft landing gear bumper of the present invention in a three-level-cushioning state;

FIG. 5 is a schematic view of an inner barrel of a bumper for an aircraft landing gear according to the present invention;

FIG. 6 is a schematic view of an aircraft landing gear bumper according to the present invention;

FIG. 7 is a top view of an aircraft landing gear bumper of the present invention;

FIG. 8 is an enlarged partial view of an aircraft landing gear damper valve body damper valve assembly of the present invention in a closed condition;

figure 9 is an enlarged partial view of an aircraft landing gear damper valve body damper valve assembly of the present invention in an open condition.

Description of reference numerals:

1: an outer cylinder; 2: an inner barrel; 3: a first chamber; 4: a second chamber; 5: a third chamber; 6: a fourth chamber; 7: a first orifice; 8: a second orifice; 9: a moving assembly; 10: a first flange; 11: a second flange; 12: a plunger; 13: a first through hole; 14: a damper valve assembly; 15: sealing the shaft sleeve; 16: a fifth chamber; 17: an inflation valve; 18: an inflation hole; 19: a piston head; 20: a piston rod; 21: a slide hole; 22: a first spring; 23: a connecting portion; 24: a limiting part; 25: a sixth chamber; 26: a fourth via hole; 27: a seventh chamber; 28: a third flange; 29: an oil filling valve; 30: an oil filling port; 31: a pressure sensor; 32: an exhaust valve; 33: a cylindrical screw cap; 34: a valve body; 35: a second spring; 36: a fourth flange; 37: a fifth flange; 38: an upper mounting seat; 39: an upper end cover; 40: a lower mounting seat; 41: a lower end cover; 42: a hinge portion; 43: sliding the seal ring; 44: an elliptical trough; 45: a guide groove.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are all used in a non-precise ratio for the purpose of facilitating and distinctly aiding in the description of the embodiments of the invention.

Referring to fig. 1 to 9, the core of the invention is to provide an aircraft landing gear buffer, which comprises an outer cylinder 1, an inner cylinder 2, a plurality of first damping holes 7, a plurality of second damping holes 8, a piston assembly, a moving assembly 9 and an elastic element, can perform three-level buffering, has good damping effect and stable damping process, automatically selects one-level or multi-level buffering according to the size of an impact load, and can absorb larger impact and filter smaller vibration.

The outer barrel 1 is of a hollow cylindrical structure, an upper mounting seat 38 is arranged at the upper end of the outer barrel 1, six bolt holes are formed in the upper mounting seat 38, an upper end cover 39 is connected to the upper mounting seat 38 through bolts, a lower mounting seat 40 is arranged at the lower end of the outer barrel 1, six bolt holes are formed in the lower mounting seat 40, and a lower end cover 41 is connected to the lower mounting seat 40 through bolts. The upper end cover 39 and the lower end cover 41 are preferably regular hexagonal prisms, six bolt holes are uniformly distributed along the circumferential direction, the upper end cover 39 and the lower end cover 41 are respectively connected with the upper mounting seat 38 and the lower mounting seat 40 of the outer cylinder 1 through bolts and hexagon nuts, and the upper end surface of the upper end cover 39 is provided with a hinge part 42 for connecting with an airplane body.

The inner cylinder 2 is arranged in the outer cylinder 1 and is connected with the inner wall of the outer cylinder 1 in a sliding manner, so that the inner cylinder can slide up and down in the outer cylinder 1, a first cavity 3 and a second cavity 4, the volume of which changes along with the sliding of the inner cylinder 2, are arranged between the inner cylinder 2 and the outer cylinder 1, specifically, the inner wall of the outer cylinder 1 is provided with a first flange 10 in sliding sealing fit with the outer wall of the inner cylinder 2, and the sliding sealing fit is that a sliding sealing ring 43 is arranged between the inner cylinder 2 and the outer wall of the inner cylinder 2, in the embodiment, the sliding sealing ring 43 is arranged below the first flange 10, so that the inner cylinder 2 can slide relative to; the outer wall of the inner cylinder 2 is provided with a second flange 11 which is matched with the inner wall of the outer cylinder 1 in a sliding sealing way, and the second flange 11 is positioned above the first flange 10. The first cavity 3 is formed by surrounding the inner wall of the outer cylinder 1, the outer wall of the inner cylinder 2, a first flange 10 and a second flange 11, and the second cavity 4 is positioned above the upper end face of the inner cylinder 2 and is formed by the upper end face of the inner cylinder 2 and the inner wall of the outer cylinder 1.

Referring to fig. 1, in the initial state, the first flange 10 and the second flange 11 contact each other, that is, the volume of the first chamber 3 is zero in the initial state, the volume of the first chamber 3 is increased when the inner cylinder 2 moves upward, the volume of the second chamber 4 is decreased, and the first flange 10 also plays a role of limiting the lower limit of the inner cylinder 2. When the inner cylinder 2 is located at the initial position, the volume of the first cavity 3 is zero, and when the inner cylinder 2 returns to the initial position after the third-stage buffering is finished, the buffer solution cannot be remained in the first cavity 3, so that the buffer solution can completely do work through the first damping holes 7 and the second damping holes 8 to dissipate impact energy, and the buffering effect is better.

The inside third chamber 5 and the fourth chamber 6 that is equipped with of inner tube 2, fourth chamber 6 are located the below of third chamber 5, and third chamber 5 is adjacent with second chamber 4, and second chamber 4 is equipped with the buffer gas, and nitrogen gas in this embodiment, third chamber 5 are equipped with the buffer solution, and hydraulic oil in this embodiment, first chamber 3 and second chamber 4 are through a plurality of first damping mount 7 intercommunication, and a plurality of first damping mount 7 sets up on second flange 11.

The second chamber 4 and the third chamber 5 are communicated through a plurality of second damping holes 8, and specifically, the hollow plunger 12 is included, the plunger 12 is arranged in the second chamber 4, and the upper end of the plunger 12 is connected to the upper end of the outer barrel 1, preferably, an internal thread is arranged on the upper end cover 39, the upper end of the plunger 12 is connected to the upper end cover 39 through a thread, so as to fix the plunger 12, and the thread connection aims to facilitate installation, disassembly and maintenance. The lower end of the plunger 12 extends into the third cavity 5 and is in sliding sealing fit with the cavity wall of the third cavity 5, the circumferential side face of the plunger 12 is provided with a plurality of first through holes 13 communicating the interior of the plunger 12 with the second cavity 4, the lower end of the plunger 12 is provided with a second damping hole 8 communicating the interior of the plunger 12 with the third cavity 5, namely, the third cavity 5 is communicated with the second cavity 4 through the second damping hole 8 in the damping valve component 14, the inner cavity of the plunger 12, the first through holes 13.

Further, a damping valve assembly 14 is arranged at the lower end of the plunger 12, the damping valve assembly 14 is provided with at least one normally-open second damping hole 8 and at least one normally-closed second damping hole 8, and in the buffer compression stage, when the hydraulic pressure of the buffer solution in the third cavity 5 is greater than the threshold value of the damping valve assembly 14, the normally-closed second damping hole 8 is opened; in the damper extension stage, the normally closed second orifice 8 is in the closed state.

Specifically, referring to fig. 8 and 9, the damping valve assembly 14 includes a cylindrical valve body 34, a normally open second damping valve is formed in the middle of the cylindrical valve body 34, the valve body 34 is disposed through a through hole disposed on the lower end surface of the plunger 12, a fourth flange 36 is disposed on a portion of the valve body 34 inside the plunger 12, a diameter of the fourth flange 36 is larger than that of the through hole on the lower end surface of the plunger 12, a normally closed second damping hole 8 is disposed on the lower end surface of the plunger 12 at a position corresponding to the fourth flange 36, a fifth flange 37 is disposed at the lower end of the valve body 34, a second spring 35 is disposed between the fifth flange 37 and the lower end surface of the plunger 12, the fourth flange 36 is tightly attached to the lower end wall of the plunger 12 by means of the elastic force of the second spring 35 in an initial state to close the normally closed second damping hole 8, when the hydraulic pressure of the buffer solution in the third chamber 5 to the valve body 34 is larger, the normally closed second damping holes 8 are opened, so that the number of the second damping holes 8 is increased, and at the moment, a buffer solution can flow out through the normally closed second damping holes 8, so that the area of the total second damping holes 8 is increased, the pressure of the buffer solution in the third cavity 5 can be reduced in a short time, a pressure relief effect is realized, the compression speed of the buffer is increased, and the over-hard damping effect is prevented. When the pressure of the buffer liquid in the third chamber 5 is less than the elastic force of the second spring 35, the valve body 34 automatically closes the normally closed second damping hole 8 under the elastic force of the second spring 35.

Because when the impact force that receives was too big, if buffer solution unit interval is when the flow of second damping hole 8 is not enough, then can not effectively cushion, can the shock attenuation is too hard will impact direct transfer and give the aircraft, makes aircraft fuselage structure suffer to destroy and can consequently set up the flow of normally closed second damping hole 8 in order to increase buffer solution when the impact force is too big, absorbs impact energy fast, makes the buffering effect better.

The piston assembly is arranged in the third cavity 5 and is used for compressing the buffer solution; the moving assembly 9 is arranged in the fourth cavity 6, and the lower end of the moving assembly is connected with an impact part; the resilient member is provided between the piston assembly and the moving assembly 9. When the impacted part is impacted, the impacted part drives the moving assembly 9 to move upwards to compress the elastic piece so as to perform first-stage buffering, and the elastic force generated by the elastic piece is continuously increased; when the elastic element is compressed to a certain degree, the elastic force of the elastic element is greater than the gravity of the piston assembly and the hydraulic pressure applied to the elastic element through the buffer solution, the elastic element drives the piston assembly to move upwards to compress the buffer solution, the hydraulic pressure is continuously increased, and the buffer solution enters the second cavity 4 through the second damping hole 8 and the plunger 12 so as to perform second-stage buffering; when the position of the limiting part 24 in the third cavity 5 is moved or the hydraulic pressure of the piston component acting on the inner cylinder 2 is greater than the gravity of the inner cylinder 2 and the air pressure applied to the inner cylinder through the buffer air, the inner cylinder 2 moves upwards to compress the buffer air, the air pressure is increased continuously, the volume of the first cavity 3 is increased, the volume of the second cavity 4 is reduced, and the buffer liquid enters the first cavity 3 through the first damping hole 7 through the air pressure of the buffer air, so that the third-stage buffering is performed.

Further, third chamber 5 is equipped with and is used for limiting the spacing portion 24 on the piston assembly, and spacing portion 24 is the stopper in this embodiment, specifically is a lug, and it is spacing that the piston assembly can rely on spacing portion 24 when making to strike great, prevents to damage inner tube 2. And the piston assembly can also push the limiting part 24 to push the inner cylinder 2 to move upwards so as to perform the third-stage buffering.

Further, third chamber 5 upper end is equipped with at least one second orifice 8, is provided with a plurality of second orifices 8 in this embodiment, under the unchangeable condition of design flow through the buffer solution of all second orifices 8, rationally can become littleer with the diameter of second orifice 8 to increase the quantity of second orifice, can dissipate more impact energy, make the buffering effect better.

Specifically, the piston assembly comprises a piston head 19 and a piston rod 20, wherein the piston head 19 is arranged in the third cavity 5 and is connected with the cavity wall of the third cavity 5 in a sliding and sealing manner; the upper end of the moving component 9 is a disc, the lower end face of the disc is provided with an elliptical groove 44 to reduce weight, the lower end of the disc is rod-shaped, the upper end of the moving component 9 is arranged on the fourth cavity 6 and is preferably in sliding fit with the cavity wall of the fourth cavity 6, so that the moving component can move up and down more smoothly, the moving component 9 is provided with a sliding hole 21, the lower end of the outer cylinder 1 is provided with a third through hole for communicating the inside and the outside of the moving component, the lower end of the moving component 9 penetrates through the third through hole, the lower end face of the moving component is provided with a connecting part 23 for connecting an impacted part, and a sealing ring is arranged between the. That is, the lower end of the moving component 9 passes through the outer cylinder 1, and the connecting part 23 is located outside the outer cylinder 1, and the impacted component is the wheel support in this embodiment.

Through the second through-hole intercommunication between third chamber 5 and the fourth chamber 6, it is concrete, during third chamber 5 chamber wall downwardly extending got into fourth chamber 6, this chamber wall outside was equipped with the external screw thread and threaded connection has a cylinder nut 33, and cylinder nut 33 center is equipped with this second through-hole, sets up cylinder nut 33 and is for the convenience of installation dismantlement, unscrews cylinder nut 33 and can take out piston head 19, has also played the lower limit that restricts piston head 19 simultaneously.

The piston rod 20 is inserted into the second through hole, and has one end connected to the piston head 19 and the other end disposed in the sliding hole 21, and can slide in the sliding hole 21. The elastic element is a first spring 22, the first spring 22 is sleeved on the piston rod 20 and located between the piston head 19 and the moving assembly 9, that is, when the impacted element is impacted, the moving assembly 9 is driven to move upwards to compress the first spring 22, and at this time, the piston rod 20 slides in the sliding hole 21.

Furthermore, two symmetrical vertical guide grooves 45 are formed in the wall of the fourth cavity 6, and the moving assembly 9 is slidably connected to the guide grooves 45. The length of the guide groove 45 is designed to be consistent with the length of the maximum stroke of the buffer, and a buffer rubber pad is arranged at the terminal of the guide groove 45 and used for buffering when the maximum stroke is reached. The guide groove 45 is arranged to enable the moving assembly to move up and down more smoothly.

Further, one end of the elastic member is provided with a pressure sensor 31 for monitoring the elastic force of the elastic member. The pressure sensor 31 is disposed on the upper end surface of the moving assembly 9 and contacts the first spring 22. The elastic force of the elastic element can be detected by the pressure sensor 31, so that the magnitude of the impact force and the working state of the buffer can be known and adjusted correspondingly.

An inflation assembly is also included for inflation of the second chamber 4. Specifically, the inflation assembly includes a sealing sleeve 15, an inflation valve 17, and an inflation port 18. Sealing shaft sleeve 15 locates 4 upper ends in second chamber, and sealing shaft sleeve 15 links firmly in upper end cover 39, just upper end cover 39 inner wall, plunger 12 upper end outer wall and sealing shaft sleeve 15 inner wall forms fifth chamber 16, and plunger 12 upper end wears to locate fifth chamber 16, and plunger 12 upper end is equipped with this inflation hole 18, and inside fifth chamber 16 and the plunger 12 of intercommunication, still be equipped with first check valve on the inflation hole 18, only allow gas to get into inside plunger 12 from fifth chamber 16, and inflation valve 17 is located on upper end cover 39 of fifth chamber 16 upper end, and the intercommunication is outside. A sealing sleeve 15 is sealingly engaged with the plunger 12, and a sealing ring is provided in the sleeve for sealing.

When the second chamber 4 is filled with buffer gas, the buffer gas firstly enters the fifth chamber 16 through the inflation valve 17, and when the gas pressure in the fifth chamber 16 is greater than that of the second chamber 4, the first check valve opens the buffer gas to enter the plunger 12, and then the buffer gas enters the second chamber 4 through the first through hole 13.

And an exhaust valve 32 communicated with the outside is arranged on the wall of the second cavity 4 and used for exhausting the second cavity 4 during maintenance and overhaul.

The device also comprises an oil injection assembly for injecting oil into the third cavity 5. The liquid injection assembly comprises a sixth cavity 25, a seventh cavity 27, an oil injection valve 29 and an oil injection port 30, the sixth cavity 25 is arranged on the inner cylinder 2 and is positioned at the periphery of the third cavity 5 and is in a hollow cylindrical shape, and a fourth through hole 26 communicated with the second cavity 4 is formed in the upper end of the sixth cavity 25; the inner wall of the outer cylinder 1 is provided with a third flange 28 which is matched with the outer wall of the inner cylinder 2 in a sliding and sealing way, in the embodiment, a sliding sealing ring 43 is arranged below the third flange 28 so that the third flange 28 is matched with the outer wall of the inner cylinder 2 in a sliding and sealing way, the third flange 28 is positioned below the first flange 10, and the inner wall of the outer cylinder 1, the outer wall of the inner cylinder 2, the first flange 10 and the third flange 28 form a seventh cavity 27; the oil filling port 30 is arranged on the wall of the chamber between the sixth chamber 25 and the seventh chamber 27, and the oil filling port 30 is provided with a second one-way valve which only allows liquid to enter the sixth chamber 25 from the seventh chamber 27; the oil filling valve 29 is arranged on the wall of the seventh cavity 27, namely the wall of the outer cylinder 1, and is communicated with the seventh cavity 27 and the outside, specifically, a threaded hole for connecting is arranged on the wall of the cylinder close to the lower end of the outer cylinder 1, and the oil filling valve 29 is arranged in the threaded hole.

When the third cavity 5 is filled with the buffer solution, the buffer solution firstly enters the seventh cavity 27 from the oil injection valve 29, when the pressure of the buffer solution in the seventh cavity 27 is greater than the pressure of the sixth cavity 25, the second one-way valve opens the buffer solution to enter the sixth cavity 25, then the buffer solution enters the second cavity 4 through the fourth through hole 26, and finally the buffer solution enters the third cavity 5 through the second damping hole 8. When the liquid injection is completed, the liquid level of the buffer solution is higher than the upper end face of the third cavity 5, that is, the second damping holes 8 are covered by the buffer solution, and the lower end of the second cavity 4 is also provided with a small amount of buffer solution.

The working process of the present invention is further explained as follows:

the process of impact compression: as the tires of the landing gear begin to contact the runway surface, the bumpers begin to compress as the aircraft lands. Referring to fig. 2, the ground first compresses the first spring 22 by the impact load of the airplane through the moving assembly 9, and the first spring 22 first works to convert the impact energy into the elastic energy of the spring.

Referring to fig. 3, with the continuous compression of the first spring 22, when the elastic force of the first spring 22 is greater than the gravity of the piston assembly itself and the hydraulic pressure applied thereto by the buffer, the second stage of compression is performed, the first spring 22 pushes the piston head 19 to move upward to compress the buffer in the third chamber 5, a part of the buffer enters the second chamber 4 through the second damping hole 8 at the upper end of the third chamber 5, a part of the buffer enters the interior of the plunger 12 through the normally open second damping hole 8 or the normally closed second damping hole 8 at the lower end of the plunger 12 and then enters the second chamber 4 through the first through hole 13, and when the buffer flows through the second damping hole 8, the buffer generates heat energy through friction in the process, so that a part of the impact energy is converted into heat energy to be dissipated.

Referring to fig. 4, when the force applied to the inner cylinder 2 by the piston assembly is greater than the gravity of the inner cylinder 2 itself and the air pressure applied thereto through the buffer air, or when the piston head 19 moves to the stopper 24, a third stage compression is performed in which the piston head 19 transmits an impact load to the inner cylinder 2, the buffer air in the second chamber 4 is compressed upward as a whole by the inner cylinder 2, and the buffer air in the second chamber 4 flows into the first chamber 3 through the first damping holes 7 under the air pressure of the buffer air, and in this process, the impact energy is dissipated by the first damping holes 7.

And (3) recovering the stretching process: the buffer starts to extend under the combined action of the gas pressure of the buffer gas and the elastic force of the first spring 22. Firstly, the air pressure of the buffer air in the second cavity 4 pushes the inner cylinder 2 to move downwards, the second flange 11 on the inner cylinder 2 moves downwards to compress the buffer solution in the first cavity 3, the buffer solution reversely flows into the second cavity 4 through the first damping hole 7, so that rebound buffering is carried out, the stretching speed is prevented from being too high, and at the moment, the buffer solution also dissipates part of impact energy through the first damping hole 7.

When the second flange 11 of the inner cylinder 2 contacts the first flange 10, the movable inner cylinder 2 stops extending. The buffer gas pressure pushes the buffer solution compressed in the second chamber 4 to reversely flow to the third chamber 5 through the second damping hole 8, so that rebound buffering is performed, the buffer solution flows through the first damping hole 8 to dissipate part of the impact energy, and then the buffer solution in the third chamber 5 pushes the piston head 19 to move downwards until the piston head 19 stops moving when returning to the initial position.

The first spring 22 also begins to expand until the moving member 9 is moved down to the initial position, and the expansion is finished.

The repeated compression and expansion consumes a part of the impact energy each time in the compression and expansion process until the buffer is finally kept at the compressed position only by the self weight of the airplane at the stop.

And the third-level buffering can be carried out simultaneously, and can also be carried out from the first-level buffering to the third-level buffering in sequence, and the third-level buffering is determined according to the design requirements and the pressure of the buffer solution and the buffer gas.

Therefore, in the compression process, the hydraulic pressure obtained by compressing the buffer solution in the third cavity 5 and the pneumatic pressure obtained by compressing the buffer gas in the second cavity 4 are used for three-stage buffering, the hydraulic pressure obtained by compressing the buffer solution in the first cavity 3, the hydraulic pressure obtained by compressing the buffer solution in the second cavity 4 and the elastic force of the first spring 22 are used for rebound buffering in the extension process, and the impact energy is converted into heat energy.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, it is still within the scope of the present invention if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. An aircraft landing gear bumper, comprising:

an outer cylinder;

the piston assembly is arranged in the third cavity;

2. An aircraft landing gear bumper according to claim 1, wherein:

3. An aircraft landing gear bumper according to claim 2, wherein the first damping aperture is provided in the second flange.

4. An aircraft landing gear bumper according to claim 2, comprising a hollow plunger, the plunger being disposed in the second chamber and having an upper end connected to the upper end of the outer barrel, a lower end extending into the third chamber and being in sliding sealing engagement with the wall of the third chamber, the plunger having a circumferential surface provided with a plurality of first through holes communicating between its interior and the second chamber, and a lower end provided with the second damping hole communicating between its interior and the third chamber.

5. An aircraft landing gear bumper according to claim 4, wherein the lower end of the plunger is provided with a damper valve assembly provided with at least one normally open second damper orifice and at least one normally closed second damper orifice, the normally closed second damper orifice opening when the damper fluid pressure in the third chamber is greater than the damper valve assembly threshold.

6. An aircraft landing gear bumper according to claim 5, wherein the third chamber is provided at its upper end with at least one of the second damping apertures.

7. An aircraft landing gear bumper according to claim 4, comprising an inflation assembly, the inflation assembly comprising:

8. The aircraft landing gear bumper of claim 1, wherein the piston assembly includes a piston head and a piston rod, the inner tube has a fourth cavity, the moving assembly is disposed in the fourth cavity, the third cavity is communicated with the fourth cavity through a second through hole, the moving assembly has a sliding hole, the elastic member is a first spring, the piston head is disposed in the third cavity, the piston rod is disposed in the second through hole, one end of the piston rod is connected to the piston head, the other end of the piston rod is disposed in the sliding hole, the piston rod can slide in the sliding hole, and the first spring is sleeved on the piston rod and is disposed between the piston head and the moving assembly.

9. An aircraft landing gear bumper according to claim 1, wherein the third chamber is provided with a limiting portion for limiting an upper limit of the piston assembly, and when the piston assembly moves to the limiting portion, the piston assembly drives the inner barrel to move upwards.

10. An aircraft landing gear bumper according to claim 1, including a priming assembly, the priming assembly including: