An anti-crash strut-type landing gear buffer

Abstract

An anti-crash strut type landing gear buffer provided by the present application, the buffer comprising: a tensile energy absorption element, including a connection part, an upper support section, a tensile energy absorption section, a lower support section and a stop platform, the connection part being fixedly connected to the helicopter fuselage; an intermediate cylinder, an upper end surface of the intermediate cylinder being in contact with the tensile energy absorption element; a shear pin, one end of the shear pin being arranged on the tensile energy absorption element, the other end of the shear pin being fixed to the helicopter fuselage; wherein, after the landing load reaches a certain value, the shear pin is sheared, the tensile energy absorption element is driven by the intermediate cylinder to move upward, starts to stretch and deform to absorb energy, and the tensile load is stable; the present application restricts the movement of the wheel to the axial movement of the buffer, which can effectively avoid the heading and lateral movement of the wheel and effectively limit the crash movement space required by the landing gear.

Description

Technical Field

[0001] This application belongs to the technical field of landing gear structure design, and particularly relates to an anti-crash strut landing gear buffer. Background Art

[0002] The landing gear is an important component of an aircraft, which is mainly used to absorb the impact energy of the aircraft and buffer the ground load during the landing or takeoff of the aircraft, and its core component is the buffer.

[0003] Generally, in order to improve the landing productivity of the aircraft, an anti-crash design is carried out. As an important energy absorption system, the landing gear generally absorbs as much landing crash load as possible.

[0004] At present, most crashed landing gears adopt a rocker configuration to obtain enough stroke to reduce the landing overload during a crash. The rocker configuration anti-crash landing gear has defects:

[0005] 1) A large space is required for the crash movement, and the fuselage needs to provide enough design space;

[0006] 2) The contour size of the landing gear is large, which is not conducive to the overall retraction and extension design.

[0007] Aiming at the problems existing in the above anti-crash landing gear buffer, the buffer provided by this application overcomes the problems existing in the above design. Summary of the Invention

[0008] Aiming at the above technical problems, this application provides an anti-crash strut landing gear buffer, and the buffer includes:

[0009] A tensile energy absorption element, including a connection part, an upper support section, a tensile energy absorption section, a lower support section and a stop platform, and the connection part is fixedly connected to the helicopter fuselage;

[0010] An intermediate cylinder, and the end face of the intermediate cylinder contacts the tensile energy absorption part;

[0011] A shear pin, one end of the shear pin is arranged on the tensile energy absorption part, and the other end of the shear pin is fixed on the helicopter fuselage;

[0012] Wherein, after the landing load reaches a certain value, the shear pin is sheared, and the tensile energy absorption element is carried by the intermediate cylinder to move upward, and starts to stretch and deform to absorb energy, and the tensile load is stable.

[0013] Preferably, the buffer further includes:

[0014] A first support end, fixedly arranged on the helicopter fuselage; wherein, the first support end is used to fix the other end of the shear pin, connect the connection part and support the upper support section of the tensile energy absorption element;

[0015] The second support end is fixedly arranged on the helicopter fuselage; wherein, the second support end supports the upper support section of the stretching energy absorption element and restricts the continuous upward movement of the stop platform of the stretching energy absorption element.

[0016] Preferably, the stretching energy absorption element is of a tubular structure and is made of a high-ductility metal material.

[0017] Preferably, the stop platform is arranged at the lower part of the second support end and has a clearance in the height direction.

[0018] Preferably, the buffer further includes:

[0019] A piston rod, one end of which is arranged in the intermediate cylinder;

[0020] A torsion arm assembly, which is arranged between the intermediate cylinder and the piston rod.

[0021] Preferably, the buffer further includes:

[0022] A throttle valve, which is arranged at one end of the piston rod close to the intermediate cylinder;

[0023] A floating piston, which is arranged in the piston rod.

[0024] Preferably, the piston rod is filled with oil and gas, the intermediate cylinder is filled with oil, one side of the floating piston is gas, and the other side of the floating piston is oil.

[0025] Preferably, the torsion arm assembly includes:

[0026] A first torsion arm, one end of which is connected to the piston rod;

[0027] A second torsion arm, one end of which is connected to the other end of the first torsion arm, and the other end of the second torsion arm is connected to the intermediate cylinder.

[0028] The beneficial technical effects of the present application are as follows:

[0029] 1) Restricting the movement of the wheel to the axial movement of the buffer can effectively avoid the heading and lateral movement of the wheel, and effectively limit the crash movement space required by the landing gear;

[0030] 2) The stretching energy absorption part is a high-ductility metal part, which does not require daily maintenance and reduces the maintenance amount of the crashworthy landing gear;

[0031] 3) It can be used for the crashworthy design of the retractable landing gear;

[0032] 4) Make full use of the internal structure space of the landing gear and reduce the space requirement of the landing gear;

[0033] 5) It can better avoid the stroke of the fuselage to absorb the remaining energy of the crash;

[0034] 6) The load of the stretching energy absorption element is stable, and it has a high energy absorption efficiency and weight reduction effect. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the fully extended anti-crash strut-type landing gear buffer provided by the embodiment of the present application;

[0036] Figure 2 It is a schematic diagram of the compression of the anti-crash strut-type landing gear buffer provided by the embodiment of the present application;

[0037] Figure 3 It is a schematic diagram of the stretching energy absorption element provided by the embodiment of the present application;

[0038] Among them, 1 - first support end; 2 - stretching energy absorption element; 3 - second support end; 4 - intermediate cylinder; 5 - throttle valve; 6 - piston rod; 7 - first torsion arm; 8 - floating piston; 9 - second torsion arm; 10 - shear pin; 20 - connection point; 21 - upper support section; 22 - stretching section; 23 - lower support section; 24 - stop platform. Detailed Embodiment

[0039] Please refer to Figures 1-3 , in the embodiment of the present application, the present invention provides an anti-crash strut-type landing gear buffer. This buffer absorbs the energy of normal landing through a conventional oil-gas design, and absorbs the energy at the rear end of the crash by adding a stretching energy absorption element. The anti-crash strut-type landing gear buffer mainly consists of a first support end 1, a stretching energy absorption element 2, a second support end 3, an intermediate cylinder 4, a throttle valve 5, a piston rod 6, a first torsion arm 7, a floating piston 8, a second torsion arm 9, a shear pin 10, etc., as Figure 1 shown.

[0040] Among them, the conventional oil-gas buffer mainly consists of an intermediate cylinder 4, a throttle valve 5, a piston rod 6, a first torsion arm 7, a floating piston 8 and a second torsion arm 9. The cooperation of the intermediate cylinder 4 and the piston rod 6 plus the stroke of the sealing element forms a sealed cavity that isolates the atmosphere.

[0041] Among them, the floating piston 8 in the piston rod 6 divides the sealed cavity into an oil cavity and a gas cavity. The throttle valve 5 divides the oil cavity into a pressure oil cavity and a return oil cavity. One end of the first torsion arm 7 is hinged to the piston rod 6, and the other end is hinged to the second torsion arm 9. One end of the second torsion arm 9 is hinged to the intermediate cylinder 4, and the other end is hinged to the first torsion arm 7.

[0042] Among them, the stretching energy absorption element 2 includes a connection part, an upper support section, a stretching energy absorption section, a lower support section, a stop platform, etc. The connection part is used to fix the stretching energy absorption element 2 to the first support end; the upper support section is provided with a shear pin mounting hole and is installed in the inner hole of the first support end in a tolerance fit manner; the stretching energy absorption section is used for stretching deformation to absorb energy; the lower support section is installed in the inner hole of the second support end in a tolerance fit manner; the stop platform is installed at the lower part of the second support end and there is a clearance in the height direction.

[0043] It should be noted that the working principle is as follows: when the carrier aircraft makes a normal landing, the tire is first compressed. When the oil pressure in the oil return cavity exceeds the air cavity pressure, the intermediate cylinder 4 and the piston rod 6 are displaced. The oil flows from the pressure oil cavity through the throttle valve 5 to the oil return cavity, and an oil damping force is generated to dissipate part of the energy; after the oil enters the oil return cavity, it pushes the floating piston 8 to squeeze the air cavity volume, and the gas is compressed to store part of the landing energy. During normal landing, the shear pin 10 does not undergo plastic deformation and only acts as a structural member to transfer the load.

[0044] When the carrier aircraft crashes, the tire is first compressed. When the oil pressure in the oil return cavity exceeds the air cavity pressure, the intermediate cylinder 4 and the piston rod 6 are displaced. The oil flows from the pressure oil cavity through the throttle valve 5 to the oil return cavity, and an oil damping force is generated to dissipate part of the energy; after the oil enters the oil return cavity, it pushes the floating piston 8 to squeeze the air cavity volume, and the gas is compressed to store part of the landing energy.

[0045] Furthermore, the buffer first absorbs part of the crash energy through the oil damping force and pneumatic energy storage. When the designed stroke of the oil and gas part of the buffer is used to a certain extent, the landing load begins to rise continuously. When the landing load reaches the bearing limit of the shear pin, the shear pin 10 is cut off, and the stretching energy absorption element 2 is carried upward by the intermediate cylinder 4. At the same time, the stop platform of the stretching energy absorption element 2 abuts against the second support end 3, and the stretching energy absorption section of the stretching energy absorption element 2 begins to stretch and deform to absorb energy.

[0046] The advantages of the buffer of the present invention are mainly as follows:

[0047] 1) Restricting the movement of the wheel to the axial movement of the buffer can effectively avoid the heading and lateral movement of the wheel, and effectively limit the crash movement space required by the landing gear;

[0048] 2) The stretching energy absorption part belongs to a high-ductility metal part, which does not require daily maintenance, reducing the maintenance amount of the crashworthy landing gear;

[0049] 3) It can be integrally retracted and extended under the action of a single retraction and extension actuator.

[0050] It should be noted that the key points of this application are: designing a trigger shear pin; designing a high-ductility stretching energy absorption element; designing a conventional oil and gas energy absorption structure to reduce the landing overload.

[0051] Meanwhile, the technology provided by this application can be applied to the design of strut type crashworthy landing gears, which is more suitable for aircraft designs with relatively insufficient landing gear space and retractable designs.

Claims

1. An anti-crash strut-type landing gear buffer, characterized in that, The buffer includes: A stretching energy absorption element, including a connection part, an upper support section, a stretching energy absorption section, a lower support section and a stop platform, wherein the connection part is fixedly connected to the helicopter fuselage; An intermediate cylinder, the upper end surface of which contacts the stretching energy absorption element; A shear pin, one end of which is arranged on the stretching energy absorption element and the other end of which is fixed to the helicopter fuselage; Wherein, when the landing load reaches the bearing limit of the shear pin, the shear pin is sheared, and the stretching energy absorption element is driven by the intermediate cylinder to move upward, starting to stretch and deform to absorb energy, and the stretching load is stable; The buffer further includes: A first support end, fixedly arranged on the helicopter fuselage; wherein, the first support end is used for fixing the other end of the shear pin, connecting the connection part and supporting the upper support section of the stretching energy absorption element; A second support end, fixedly arranged on the helicopter fuselage; wherein, the second support end supports the upper support section of the stretching energy absorption element and restricts the continuous upward movement of the stop platform of the stretching energy absorption element; The stretching energy absorption element is of a tubular structure and is made of a high-ductility metal material; The stop platform is arranged below the second support end and has a clearance in the height direction; The buffer further includes: A piston rod, one end of which is arranged in the intermediate cylinder; A torsion arm assembly, arranged between the intermediate cylinder and the piston rod; The buffer further includes: A throttle valve, arranged at one end of the piston rod close to the intermediate cylinder; A floating piston, arranged in the piston rod; The piston rod is filled with oil and gas, the intermediate cylinder is filled with oil, one side of the floating piston is gas and the other side is oil.

2. The anti-crash strut landing gear buffer according to claim 1, characterized in that, The torsion arm assembly includes: A first torsion arm, one end of which is connected to the piston rod; A second torsion arm, one end of which is connected to the other end of the first torsion arm and the other end of which is connected to the intermediate cylinder.

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