CN111470036A - Anti single leg buffer structure and leg formula undercarriage that hit that weigh down - Google Patents

Abstract

The invention belongs to the technical field of landing gears of vertical take-off and landing aircrafts, and discloses a single-leg buffer structure capable of resisting falling and collision and a leg type landing gear. Based on the concept design of the bionics, through: the mechanism motion actively controls to reduce the overload peak value, the buffer damping energy consumption, the structure controlled plastic deformation damages a three-level energy absorption/buffering mode, and an impedance active control method is assisted, so that the impact peak value overload is greatly reduced, the impact kinetic energy is effectively reduced and transmitted to the machine body, and the mechanism motion actively controls to reduce the overload peak value, and has obvious effects on improving the structure safety and the crash viability of passengers; meanwhile, the efficiency of buffering and energy absorption of the undercarriage is improved, the requirement of falling collision and energy absorption of the machine body is reduced to a certain extent, and the undercarriage has positive significance for reducing the weight of the machine body structure.

Description

Anti single leg buffer structure and leg formula undercarriage that hit that weigh down

Technical Field

The invention belongs to the technical field of a vertical take-off and landing aircraft landing device, and particularly relates to a single-leg buffer structure capable of resisting falling and collision and a leg type landing gear, which are applied to the landing gear design of a vertical take-off and landing aircraft for executing special task requirements so as to meet the requirement of resisting falling and collision under complex and extreme conditions.

Background

The vertical take-off and landing aircraft has the characteristics of vertical take-off and landing, fixed-point hovering in the air, low-speed flight, low-altitude and ultra-low-altitude flight, in-situ steering, flight in any direction and the like, and is taken as an ideal aircraft in the occasions with limited take-off and landing fields, narrow flight space and requirements for executing low-altitude and low-speed tasks, so that the vertical take-off and landing aircraft has wide application prospects.

At present, landing gears applied to the vertical take-off and landing aircraft are mostly of skid structures, and wheel type landing gears are adopted for the vertical take-off and landing aircraft with large weight. However, the conventional landing gear has many application limitations, such as uneven ground, field environment and the like, when emergency landing is required. At the moment, when the vertical take-off and landing aircraft falls in an emergency and the flight environment is very complex, the phenomenon of crash is easy to occur.

For example, in the iraq war, when an army 'hawk' helicopter carries out emergency landing in a desert area, due to inaccurate judgment on a sloping landing sand field, large-area sand dust raised by a rotor wing is caused, so that a pilot has an illusion and cannot carry out normal operation, and the helicopter loses control and crashes. For another example, when the helicopter descends at a high speed, the vortex ring is rapidly deteriorated, so that the lift force is rapidly reduced, the descending speed of the helicopter is easily uncontrollable, and two very remarkable crashes of the American V-22 tilt rotor helicopter in the test flight stage are caused by the vortex ring. Therefore, it is desirable to weigh the landing gear system and the crash resistance. The crash resistance is an important index for measuring the performance of the vertical take-off and landing aircraft, and the landing gear plays an important role in reducing the damage of a hard landing structure and improving the survival rate of passengers. Because the traditional landing gear adopts plastic deformation energy absorption or buffer energy absorption, the crash energy absorption efficiency is less than 60 percent.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a single-leg buffer structure for resisting falling collision and a leg type undercarriage, which are used for improving the energy absorption efficiency of a vertical take-off and landing aircraft in a bionic falling collision accident so as to improve the crash viability. The invention provides a single-leg design configuration and a method of the landing gear, which are provided by the invention, because the legged landing gear adopts a symmetrical multi-leg design. In the military and civil field, the invention can improve the safety performance of the vertical take-off and landing aircraft to a great extent, improve the recovery rate and the utilization rate of the vertical take-off and landing aircraft, break the landing scene limitation of the vertical take-off and landing aircraft and contribute to improving the landing safety.

In order to achieve the purpose, the invention provides the following technical scheme:

the first technical scheme is as follows:

a single leg cushioning structure resistant to falling impact, said single leg cushioning structure comprising: the first active buffer joint, the bionic leg type undercarriage thigh joint, the bionic leg type undercarriage shin joint, a shin joint buffer and a foot end buffer;

the bionic leg type undercarriage thigh joint is connected with the bionic leg type undercarriage shank joint through the first active buffering joint, the shank joint buffer is installed in the middle of the bionic leg type undercarriage shank joint, and the foot end buffer is installed at the tail end of the bionic leg type undercarriage shank joint.

The first technical scheme of the invention has the characteristics and further improvements that:

(1) the shin section buffer is composed of a buffer upper flange plate, a buffer outer sleeve, filling energy-absorbing materials, a first connecting bolt, a second connecting bolt and a buffer lower flange plate;

the upper flange plate of the buffer is connected with the upper part of the shank of the bionic leg landing gear through a first connecting bolt, the lower flange plate of the buffer is connected with the lower part of the shank of the bionic leg landing gear through a second connecting bolt, the outer sleeve of the buffer is arranged between the upper flange plate of the buffer and the lower flange plate of the buffer, and the filling energy-absorbing material is fixedly arranged inside the outer sleeve of the buffer.

(2) The filling energy-absorbing material is made of honeycomb aluminum or foamed aluminum material.

(3) The foot end buffer consists of a foot end buffer sleeve, a buffer spring, a buffer structure, a spherical hinge and sole rubber;

the foot end buffer sleeve is arranged at the tail end of the shank of the bionic leg type landing gear, the buffer spring and the buffer structure are arranged inside the foot end buffer sleeve, and the buffer spring surrounds the outer side of the buffer structure; the sole rubber and the buffer structure are connected through a spherical hinge.

(4) The buffer structure is realized by rubber, sponge or resin.

(5) The sole rubber is hemispherical rubber.

The second technical scheme is as follows:

a falling-resistant leg-striking undercarriage comprises an undercarriage mounting interface, a plurality of falling-resistant leg-striking buffer structures according to the technical scheme I, and a plurality of second active buffer joints;

the upper ends of bionic leg type undercarriage thigh joints in the plurality of anti-falling single-leg buffer structures are installed on an undercarriage installation interface through corresponding second active buffer joints, and the undercarriage installation interface is fixedly installed on the vertical take-off and landing aircraft.

The second technical scheme of the invention has the characteristics and further improvements that:

a rotary joint is arranged in the undercarriage mounting interface, and steering of the undercarriage mounting interface is achieved.

The invention provides a drop-resistant leg-impacting type undercarriage, which adopts an active control method and is used for solving the problem of drop-impact energy absorption in the landing process of a vertical take-off and landing aircraft. The landing gear provided by the invention is designed based on the concept of bionics, and the crash energy absorption mode is essentially different from the traditional landing gear by the following steps: (i) the mechanism motion actively controls to reduce an overload peak value, (ii) the buffer damps energy consumption, (iii) the structure is controlled to deform to destroy a three-level energy absorption/buffering mode, and an impedance active control algorithm is assisted to greatly reduce the impact peak value overload and effectively reduce the transmission of impact kinetic energy to a machine body, so that the mechanism motion actively controls to reduce the overload peak value, and has obvious effects on increasing the structure safety and improving the crash viability of passengers; meanwhile, the efficiency of buffering and energy absorption of the undercarriage is improved, the requirement of falling collision and energy absorption of the machine body is reduced to a certain extent, and the undercarriage has positive significance for reducing the weight of the machine body structure. The technical scheme of the invention can effectively improve the landing safety of the vertical take-off and landing aircraft, breaks through a plurality of limitations of the application environment of the traditional landing gear, and conforms to the development trend of the adaptability of the aircraft to complex environments.

Drawings

FIG. 1 is a schematic view of a drop resistant landing gear according to an embodiment of the present invention;

FIG. 2 is a schematic view of a tibioganglion buffer provided in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of a sole bumper according to an embodiment of the present invention;

FIG. 4 is a schematic view of the operation of the sole bumper according to the embodiment of the present invention, wherein (a) is in an extended state and (b) is in a compressed state;

fig. 5 is a schematic diagram illustrating changes in the attitude of the active damping joint control landing gear according to an embodiment of the present invention, where (a) is a pre-landing state and (b) is a post-landing state;

fig. 6 is a schematic diagram of an emergency crash working process provided in the embodiment of the present invention, wherein (a) is a pre-landing state and (b) is a post-landing state;

in the figure: the landing gear comprises a vertical take-off and landing aircraft, 2 a landing gear mounting interface, 3 an anti-falling landing gear, 4 an active buffer joint, 5 a shin section buffer, 6 a foot end buffer, 7 a rotary joint, 31 a bionic leg landing gear shin section, 32 a bionic leg landing gear thigh section, 51 a buffer upper flange plate, 52 a buffer outer sleeve, 53 a filling energy absorption material, 54 a connecting bolt, 55 a buffer lower flange plate, 61 a foot end buffer sleeve, 62 a buffer spring, 63 a buffer structure, 64 a spherical hinge ball socket, 65 a spherical hinge ball head and 66 sole rubber.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1, an anti-drop landing gear 3 according to an embodiment of the present invention is mounted on a vertical take-off and landing aircraft 1 through a landing gear mounting interface 2, and each single-leg buffer structure of the anti-drop landing gear 3 (which is composed of a plurality of single-leg buffer structures) is composed of a bionic leg landing gear leg joint 31, a bionic leg landing gear leg joint 32, an active buffer joint 4, a leg joint buffer 5, and a foot end buffer 6.

The landing gear installation interface 2 is an installation frame of the anti-falling leg-hitting landing gear 3, is made of high-strength light materials such as aluminum alloy, titanium alloy and composite materials according to structural adaptation of the specific vertical take-off and landing aircraft 1, is prefabricated with matching interfaces of various types of anti-falling leg-hitting landing gear 3, and can select the number of the anti-falling leg-hitting landing gears 3 according to task needs. A rotary joint 7 is arranged in the landing gear mounting interface 2, and steering of the bionic leg type landing gear is achieved.

The anti-drop leg-hitting landing gear 3 is composed of a plurality of single legs (3, 4 and 6) with the same structure, each leg has 2 degrees of freedom, the single legs are realized through 2 sets of active buffer joints 4, the legs are divided into 2 sections, and the buffer structures are arranged on shin joints and are respectively realized through a shin joint buffer 5 and a foot end buffer 6.

And 2 sleeves are arranged on each leg of the active buffer joint 4 and respectively arranged between a shin joint 31 of the bionic leg type undercarriage and a thigh joint 32 of the bionic leg type undercarriage and between the thigh joint 32 of the bionic leg type undercarriage and an undercarriage mounting interface 2, and the landing load is absorbed by adjusting the posture and the movement speed of the anti-falling leg type undercarriage 3 so as to adapt to the landing terrain.

As shown in fig. 2, the shank damper 5 is installed between the simulated legged landing gear shanks 31 and is composed of a damper upper flange plate 51, a damper outer sleeve 52, a filling energy absorbing material 53, a connecting bolt 54 and a damper lower flange plate 55. The upper flange plate 51 of the buffer is connected with the upper half part of the leg-type knuckle 31 of the bionic leg-type landing gear through a connecting bolt 54, the lower flange plate 55 of the buffer is connected with the lower half part of the leg-type knuckle 31 of the bionic leg-type landing gear through a connecting bolt 54, and the upper flange plate 51 of the buffer and the lower flange plate 55 of the buffer are both made of aluminum alloy materials with corresponding strength and rigidity. The outer buffer sleeve 52 is arranged between the upper buffer flange plate 51 and the lower buffer flange plate 55 and is of a thin-wall aluminum pipe structure. The filled energy absorbing material 53 is fixedly mounted inside the bumper outer sleeve 52 and is a honeycomb aluminum or foamed aluminum material.

As shown in fig. 3, the toe end bumper 6 is mounted at the end of the shank 31 of the simulated legged landing gear, the toe end bumper sleeve 61 and the end of the shank 31 of the simulated legged landing gear, the bumper spring 62 and the bumper structure 63 are mounted inside the toe end bumper sleeve 61, the bumper spring 62 surrounds the outside of the bumper structure 63, and the bumper structure 63 may be made of rubber, sponge, resin, or other materials. The sole is buffered by a piece of hemispherical sole rubber 66, the sole rubber 66 is connected with the buffer structure 63 through a spherical hinge, wherein the bottom of the buffer structure 63 is connected with a spherical hinge ball socket 64, and the sole rubber 66 is connected with a spherical hinge ball head 65.

Specific example 1: complex ground landing buffer

When the buffer is applied to the complex ground landing, the buffer refers to the condition of normal slow landing, at the moment, the ground load is small, and the working starting threshold value of the tibioganglion buffer 5 cannot be reached, so that the tibioganglion buffer 5 is in a non-compression state at the moment and plays a role in supporting during landing. The landing process is a mode of level 2 buffering.

During landing, the terrain condition of the ground is determined through a 3D radar system, the anti-falling leg-hitting type undercarriage 3 completes pre-swinging of the posture under the action of the active buffer joint 4 according to the terrain condition, at the moment, the leg is ensured to be straightened as far as possible, the shank 31 of the bionic leg type undercarriage is in a state vertical to the ground, and the foot end sole rubbers 66 of a plurality of legs are ensured to touch the ground simultaneously during landing. After the sole rubber 66 contacts the ground, a reaction force acting on the drop-resistant landing gear 3 is generated due to the action of the ground load, the active damping joint 4 receives the action of a reaction torque, and the change of the torque is detected by the torque sensor mounted on the active damping joint 4, so that the condition that the foot end contacts the ground is indicated.

After the ground is contacted with the ground, the system starts to play a role of 2-level buffering, the 2-level buffering works simultaneously, and the comprehensive effect is achieved, so that the effects of absorbing landing impact energy and reducing ground load are achieved.

The foot end buffer 6 is the first stage of buffering of the system, and passively buffers the process of absorbing energy. The working process is that after the sole rubber 66 contacts the ground, the effect of reducing the ground load is achieved, force is transmitted to the buffer material through the spherical hinges 64 and 65, and the buffer spring 62 and the buffer structure 63 are compressed under the action of external force, so that the ground load is further reduced. The ball joints 64, 65 may be used to avoid jamming of the compression process which should be caused by uneven ground. Buffer spring 62 and buffer structure 63 are at compression and release in-process, and buffer spring 62 and foot end buffer sleeve 61 inner wall can produce the friction, and buffer spring 62 and buffer structure 63 also can produce the friction, produces the resistance through frictional force, and energy consumption avoids kick-backing. The forced compression and rebound extension of the foot end bumper 6 is shown in figure 4.

The active damping joint 4 is the second stage of damping of the system, which is the process of active damping control. The foot end buffer 6 can only absorb a small part of energy at the moment of touching the ground, the buffering requirement of the undercarriage cannot be met, and active buffering is required to be realized through the active buffering joint 4 according to specific requirements. The active buffering joint 4 increases the buffering stroke by changing the pose of the anti-falling leg-hitting type undercarriage 3 in the landing process, so that the ground load is reduced. The active buffer joint consists of a servo motor, a driver, a brake, a torque sensor and a control system. When the control system obtains a torque signal fed back by the torque sensor, the control driver drives the servo motor to operate, so that the torque is reduced, the anti-falling leg-hitting type undercarriage 3 is changed from a standing position to a squatting position, and the buffering is realized. When the servo motor rotates, the leg joints 31 and the thigh joints 32 of the bionic leg landing gear are driven to move, and friction force is generated under the action of a brake in the moving process, so that system impact energy is consumed. The active damping joint 4 controls the landing gear system posture change as shown in figure 5.

Specific example 2: emergency drop

When the system is applied to emergency crash landing, if the aircraft falls at the speed of 10.2m/s, the flight control system of the vertical take-off and landing aircraft 1 breaks down, timely feedback and real-time control cannot be achieved, and the landing time is short. Because a larger landing speed causes a larger ground load to reach the working start threshold of the tibiofemoral buffer 5, the tibiofemoral buffer 5 is in a passive compression state after landing to achieve the purpose of dissipating energy, and the specific compression condition is also determined according to the landing energy. The landing process at this time is a mode of 3-level buffering.

Except that the reaction conditions were similar to those in "embodiment 1: the impact state structural failure mode of the filled energy-absorbing material 53 is excited, so that the falling impact energy can be absorbed, and the vertical impact overload can be reduced, besides the 2-level buffering in the same process explained in the complex ground landing buffering. In the falling and collision process, based on the dead point of the connecting rod structure, the anti-falling and leg-hitting landing gear 3 is adjusted through the active buffering joint 4, so that the leg is in the dead point position, the shank 31 of the bionic leg landing gear is in the posture vertical to the ground, and the energy generated by falling and collision is mainly absorbed through the shank buffer 5. The outer bumper sleeve 52 and the filled energy-absorbing material 53 are plastically deformed to absorb energy during a crash, and the diameter and length of the outer bumper sleeve 52 and the design of the filled energy-absorbing material 53 are determined according to the crash resistance requirement and the type of the VTOL aircraft.

The technical scheme of the invention is as follows:

(1) the installation of the anti-drop leg-hitting type undercarriage can ensure the safety of the vertical take-off and landing aircraft under the conditions of emergency landing and accidental drop collision, ensure the landing safety under the condition of high sinking speed, and effectively improve the viability of the aircraft and crash;

(2) the requirements of the traditional landing gear on the landing ground and the external environment during landing are broken, the landing safety of the vertical take-off and landing aircraft is improved, and the side turning and rotor landing of the vertical take-off and landing aircraft caused by the problems of ground flatness and gradient are prevented;

(3) the aircraft is applied to the manned vertical take-off and landing aircraft, so that the dependence on the driving experience of a pilot can be reduced, and the crash accidents caused by the improper manual operation can be reduced.

Main innovation of the invention

The anti-falling leg-impacting landing gear changes the passive buffering mode of the original landing gear into the active buffering mode, and after the vertical take-off and landing aircraft lands, the landing energy is absorbed through joint energy absorption, buffer energy absorption and sole elastic energy absorption, and the energy absorption mode of the original buffer can be changed by adjusting in real time according to the state of the aircraft body and the actual landing energy.

The anti-falling leg-hitting landing gear provided by the invention can adapt to different landing terrains, and can adapt to the landing terrains by changing the postures of the legs when the ground is uneven or has a slope, so that the current situation that the landing can only be carried out on a flat paved runway and a parking apron is broken.

The anti-falling leg-collision landing gear provided by the invention has multiple landing modes, the landing gear only plays a role of buffering under the normal landing condition, and when an emergency falling collision condition occurs, the landing gear can be automatically triggered to adopt a falling collision energy absorption mode according to the size of a landing load, so that the landing safety of a vertical take-off and landing aircraft is effectively protected.

The anti-falling leg-hitting landing gear provided by the invention adopts a three-stage energy absorption mode, can better absorb energy, and avoids the accident condition caused by failure of a certain stage. And at the moment of falling on the ground, a buffer structure and mechanical structure energy absorption mode is adopted, so that reverse torque cannot be added to a driving motor system, and the safety of a driving system and the safety of a machine body structural member can be better protected.

Claims (8)

1. A single leg cushioning structure that weighs down and hits, its characterized in that, single leg cushioning structure includes: the first active buffer joint, the bionic leg type undercarriage thigh joint, the bionic leg type undercarriage shin joint, a shin joint buffer and a foot end buffer;

the bionic leg type undercarriage thigh joint is connected with the bionic leg type undercarriage shank joint through the first active buffering joint, the shank joint buffer is installed in the middle of the bionic leg type undercarriage shank joint, and the foot end buffer is installed at the tail end of the bionic leg type undercarriage shank joint.

2. The anti-drop single leg bumper structure according to claim 1, wherein the shank segment bumper is composed of a bumper upper flange plate, a bumper outer sleeve, a filling energy absorbing material, a first connecting bolt, a second connecting bolt and a bumper lower flange plate;

the upper flange plate of the buffer is connected with the upper part of the shank of the bionic leg landing gear through a first connecting bolt, the lower flange plate of the buffer is connected with the lower part of the shank of the bionic leg landing gear through a second connecting bolt, the outer sleeve of the buffer is arranged between the upper flange plate of the buffer and the lower flange plate of the buffer, and the filling energy-absorbing material is fixedly arranged inside the outer sleeve of the buffer.

3. The crash-resistant single-leg bumper structure of claim 2, wherein said filled energy-absorbing material is a honeycomb aluminum or foamed aluminum material.

4. The anti-drop single leg cushion structure according to claim 1, wherein the foot end bumper is composed of a foot end bumper sleeve, a cushion spring, a cushion structure, a ball hinge and a sole rubber;

the foot end buffer sleeve is arranged at the tail end of the shank of the bionic leg type landing gear, the buffer spring and the buffer structure are arranged inside the foot end buffer sleeve, and the buffer spring surrounds the outer side of the buffer structure; the sole rubber and the buffer structure are connected through a spherical hinge.

5. The anti-falling single-leg buffer structure as claimed in claim 4, wherein the buffer structure is implemented by rubber, sponge or resin.

6. The anti-drop single leg bumper structure according to claim 4, wherein the sole rubber is a hemispherical rubber.

7. A drop-resistant landing gear comprising a landing gear mounting interface, a plurality of drop-resistant single leg cushioning structures as claimed in any one of claims 1 to 6, a plurality of second active cushioning joints;

the upper ends of bionic leg type undercarriage thigh joints in the plurality of anti-falling single-leg buffer structures are installed on an undercarriage installation interface through corresponding second active buffer joints, and the undercarriage installation interface is fixedly installed on the vertical take-off and landing aircraft.

8. An anti-drop landing gear according to claim 7, wherein a rotary joint is provided within the landing gear mounting interface to effect steering of the landing gear mounting interface.

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