An electrical dual-redundancy all-electric landing gear emergency release test system and test method

Abstract

The present invention relates to the field of aircraft technology, and discloses an electrical dual-redundancy all-electric landing gear emergency release test system and test method. The electrical dual-redundancy all-electric landing gear emergency release test system comprises: an aircraft bracket, used to support the aircraft fuselage to lift the wheels off the ground; a plurality of buffer components, which include a buffer support plate and a buffer bag, the buffer bag is slidably arranged above the buffer support plate, the buffer bag is used to collide with the wheels to absorb the kinetic energy generated by the emergency release of the landing gear, and the number of buffer components is the same as the number of wheels. By using the buffer component to absorb the momentum generated by the emergency release of the landing gear, the vibration load on the aircraft body is significantly reduced.

Description

Technical Field

[0001] The present invention relates to the field of aircraft technology, and more specifically to an electrical dual-redundancy all-electric landing gear emergency release test system. In addition, the present invention also provides a test method for the all-electric landing gear emergency release test system. Background Art

[0002] The landing gear retraction system is an important equipment for fixed-wing aircraft. The landing gear retraction system of large and medium-sized aircraft is usually a dual-redundant setting.

[0003] At present, the architectures of dual-redundant landing gear retraction and extension systems include hydraulic + emergency gas, dual-redundant all-electric actuator, and single-redundant all-electric actuator + emergency gas. Among them, the single-redundant all-electric actuator + emergency gas architecture is a non-similar margin architecture, which avoids the common problems of similar margin. At the same time, it does not have a hydraulic system and has a simple structure.

[0004] When the landing gear retraction and extension system of the single redundant all-electric actuator + emergency air frame is undergoing an emergency release test, since the interior of the electric actuator is filled with air, the flow resistance is very small when the exhaust is extended from the cavity. When the landing gear is lowered into place, the impact load is instantly applied to both ends of the actuator and then transmitted to the aircraft body, causing the aircraft to be subjected to a large vibration shock during the emergency release test on the ground, which is likely to cause damage to the aircraft structure.

[0005] In summary, how to reduce the vibration impact on the aircraft during the electrical dual-redundancy all-electric landing gear emergency release test system is a problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a dual-redundant all-electric landing gear emergency release test system, which can utilize a buffer component to absorb the momentum generated by the emergency lowering of the landing gear, thereby significantly reducing the vibration load on the aircraft body.

[0007] In addition, the present invention also provides a test method for the above dual-redundancy all-electric landing gear emergency release test system.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] An electrical dual-redundancy all-electric landing gear emergency release test system, comprising:

[0010] Aircraft cradles, used to support the fuselage of an aircraft to keep the wheels off the ground;

[0011] A plurality of buffer assemblies include a buffer support plate and a buffer bag. The buffer bag is slidably arranged above the buffer support plate. The buffer bag is used to collide with the wheel to absorb the kinetic energy generated by the emergency lowering of the landing gear. The number of the buffer assemblies is the same as the number of the wheels.

[0012] Preferably, the outer periphery of the buffer bag is covered with at least one layer of buffer pad, and the buffer pad includes a polyurethane foam pad or a polyethylene foam pad.

[0013] Preferably, the buffer pad is fixed to the outside of the buffer bag by tying with a cable tie, and the cable tie is evenly arranged along the height direction of the buffer bag.

[0014] Preferably, the buffer pad is bonded to the outside of the buffer bag, and the buffer pad is bonded to the buffer bag by Velcro or glue.

[0015] Preferably, the buffer bag comprises a multi-layer woven bag, and fine gravel for buffering and absorbing vibration is arranged in the multi-layer woven bag.

[0016] Preferably, the upper surface of the buffer support plate is provided with at least two intersecting positioning lines, and the intersection of the positioning lines is arranged directly below the wheel.

[0017] Preferably, the buffer support plate comprises a rectangular support plate, and the positioning line is a center line arranged perpendicular to the outer edge of the rectangular support plate.

[0018] A test method, used for the electrical dual-redundancy all-electric landing gear emergency release test system described in any one of the above, comprising:

[0019] The mass of the cushioning bag is determined by calculating the basic parameters of the emergency release of the aircraft landing gear;

[0020] Lifting the aircraft using an aircraft bracket, and placing a buffer tray directly under the landing gear;

[0021] Stowing the landing gear, and placing the buffer bag in the center of the buffer support plate;

[0022] Emergency release of the landing gear, and after it is fully lowered, locking the landing gear.

[0023] Preferably, the method of calculating and determining the mass of the buffer bag according to the basic parameters of the emergency release of the aircraft landing gear includes:

[0024] Calculate the gravitational potential energy during the emergency deployment of the landing gear , where m is the mass of a single landing gear, g is the acceleration of gravity, and h is the height of the center of gravity change of a single landing gear;

[0025] Calculate the work done by the emergency air system during emergency deployment of the landing gear ,in, is the initial pressure of the emergency gas system, It is the pressure of the emergency gas system after emergency release. is the initial volume of the emergency gas system, is the volume of the emergency gas system after emergency release, is the insulation coefficient;

[0026] Calculate the wheel speed of the emergency rear landing gear and equivalent mass ,in, is the distance from the wheel axle to the landing gear axis, is the distance from the landing gear center of gravity to the landing gear axis;

[0027] According to the design residual speed after the wheel impacts the buffer package , through the conservation of momentum and energy conservation Calculate and obtain the quality of the buffer package .

[0028] Preferably, the designed residual speed after the wheel impacts the buffer pack .

[0029] The electrical dual-redundant all-electric landing gear emergency release test system provided by the present invention can absorb the kinetic energy generated by the emergency release of the landing gear through the collision between the buffer bag and the wheel, reduce the vibration impact load transmitted to the aircraft body, thereby effectively reducing or even avoiding the aircraft body structure damage caused by this.

[0030] In addition, the present invention also provides a test method for the above-mentioned electrical dual-redundancy all-electric landing gear emergency release test system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the test principle of the electrical dual-redundancy all-electric landing gear emergency release test system provided by the present invention;

[0033] Figure 2 for Figure 1 A schematic diagram of the structure of the buffer component;

[0034] Figure 3 This is a flow chart of the electrical dual-redundancy all-electric landing gear emergency release test system.

[0035] Figure 1-Figure 3 middle:

[0036] 01-aircraft; 10-aircraft bracket; 20-buffer assembly; 21-buffer tray; 211-positioning line; 22-buffer bag; 23-buffer pad. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The core of the present invention is to provide a dual-redundant all-electric landing gear emergency release test system, which can utilize a buffer component to absorb the momentum generated by the emergency release of the landing gear, thereby significantly reducing the vibration load on the aircraft body.

[0039] In addition, the present invention also provides a test method for the above dual-redundancy all-electric landing gear emergency release test system.

[0040] The electrical dual-redundancy all-electric landing gear emergency release test system provided by the present invention comprises:

[0041] The aircraft bracket 10 is used to support the fuselage of the aircraft 01 so that the wheels are off the ground;

[0042] A plurality of buffer assemblies 20 include a buffer support plate 21 and a buffer bag 22. The buffer bag 22 is slidably disposed above the buffer support plate 21. The buffer bag 22 is used to collide with the wheel to absorb the kinetic energy generated by the emergency lowering of the landing gear. The number of the buffer assemblies 20 is the same as the number of the wheels.

[0043] Please refer to Figure 1 The aircraft bracket 10 is used to support the aircraft 01 so that the wheels are off the ground, so that the buffer support plate 21 of the buffer assembly 20 is placed under the wheels of the landing gear. It can be understood that the height of the wheels off the ground should be greater than or equal to the thickness of the buffer support plate 21.

[0044] A slidable buffer bag 22 is placed above the buffer support plate 21. The buffer bag 22 is used to collide with the wheel tire when the landing gear is emergency lowered, thereby absorbing the kinetic energy generated by the emergency lowering of the landing gear and reducing the impact load on the aircraft 01 body.

[0045] The number of buffer assemblies 20 is the same as the number of wheels, so as to provide effective buffering for each wheel when the landing gear is deployed in an emergency; the material and size of the buffer assembly 20 need to be determined based on the momentum generated in the landing gear emergency deployment test in actual testing to ensure that the buffer assembly 20 has a good buffering effect.

[0046] The buffer support plate 21 is usually made of polyethylene plastic plate, which has a smooth surface and good wear resistance. When the buffer bag 22 is impacted, it can slide along the buffer support plate 21, so that the buffer bag 22 is stuck under the corresponding wheel.

[0047] The buffer bag 22 can be specifically configured as a buffer sandbag, a buffer air cushion, etc. Considering the cost and ease of use, the buffer bag 22 is usually configured as a buffer sandbag, which is easy to obtain and has a low cost. The amount of fillers such as gravel filled in the buffer sandbag can be easily adjusted according to actual needs, and is easy to use.

[0048] For example, the buffer bag 22 can be set as a multi-layer woven bag, in which fine gravel is arranged for buffering and vibration absorption. The design of the multi-layer woven bag can enhance the wear resistance and strength of the buffer bag 22 and prevent the buffer bag 22 from being damaged due to impact. The fine gravel filled inside has a better buffering effect than coarse sand particles.

[0049] In this embodiment, the kinetic energy generated by the emergency lowering of the landing gear can be absorbed by the collision between the buffer bag 22 and the wheel, thereby reducing the vibration impact load transmitted to the body of the aircraft 01, thereby effectively reducing or even avoiding the structural damage to the body of the aircraft 01 caused by this.

[0050] On the basis of the above embodiment, in order to better protect the tire of the wheel, at least one layer of buffer pad 23 can be coated on the outer periphery of the buffer bag 22, such as Figure 2 As shown, the buffer pad 23 includes a polyurethane foam pad or a polyethylene foam pad, which is light in weight, good in elasticity, and has good buffering and vibration reduction capabilities.

[0051] The specific material and thickness of the buffer pad 23 are determined according to the design buffering and vibration reduction requirements in actual tests, and the buffer pad 23 is usually set to 3-5 cm; the buffer pad 23 can be connected to the buffer bag 22 by means of cable ties, bonding, etc.

[0052] For example, the buffer pad 23 can be fixed to the outside of the buffer bag 22 by tying with cable ties. The cable ties are evenly arranged along the height direction of the buffer bag 22. By tying and untying the cable ties, the buffer pad 23 can be fixed to the outside of the buffer bag 22, or the buffer pad 23 can be separated from the buffer bag 22 for storage.

[0053] It is understandable that the number and spacing of cable ties are related to the height of the buffer bag 22 in actual testing. When the height of the buffer bag 22 is small, the cable ties are usually arranged at both ends of the buffer bag 22 in the height direction. When the height of the buffer bag 22 is large, the cable ties at both ends are difficult to effectively fix the buffer pad 23. In order to make the middle buffer pad 23 close to the outer peripheral surface of the buffer bag 22, it is often necessary to increase the number of cable ties in the middle of the buffer bag 22 in the height direction as appropriate.

[0054] Of course, the buffer pad 23 may also be bonded to the outside of the buffer bag 22 , and the buffer pad 23 may be bonded to the buffer bag 22 by Velcro or glue.

[0055] On the basis of the above embodiment, in order to facilitate the alignment of the buffer plate 21 and the landing gear wheel, at least two intersecting positioning lines 211 may be provided on the upper surface of the buffer plate 21, and the intersection of the positioning lines 211 is located directly below the wheel.

[0056] Here, the intersection of the positioning lines 211 is located directly below the wheel, that is, the projection of the tire axle of the wheel on the buffer support plate 21 falls on the intersection of the positioning lines 211 .

[0057] The positioning line 211 may be a line on the upper surface of the buffer support plate 21 , a positioning strip bonded to the upper surface of the buffer support plate 21 , or a positioning groove provided on the upper surface of the buffer support plate 21 .

[0058] In order to facilitate alignment, the buffer support plate 21 is preferably configured to include a rectangular support plate, and the positioning line 211 is a center line arranged perpendicular to the outer edge of the rectangular support plate. The orthogonal arrangement of the positioning line 211 is conducive to the alignment of the buffer support plate 21 and the wheel.

[0059] The positioning line 211 located in the heading direction of the aircraft is the heading positioning line, and the positioning line 211 located in the lateral direction of the aircraft is the lateral positioning line. When placing the buffer tray 21 under the landing gear, the position of the buffer tray 21 needs to be adjusted so that in the lateral direction of the aircraft, the tire axis of the wheel is perpendicular to the heading positioning line, and at the same time, in the heading direction of the aircraft, the center line of the wheel table is perpendicular to the lateral positioning line. At this time, it can be considered that the intersection of the two positioning lines 211 of the buffer tray 21 is located directly below the wheel of the aircraft 01.

[0060] In addition to the above-mentioned electrical dual-redundancy all-electric landing gear emergency release test system, the present invention also provides a test method including the electrical dual-redundancy all-electric landing gear emergency release test system disclosed in the above-mentioned embodiment, please refer to Figure 3 ,include:

[0061] Step S1, calculating and determining the mass of the buffer bag 22 according to the basic parameters of the emergency release of the landing gear of the aircraft 01;

[0062] Step S2, using the aircraft bracket 10 to lift the aircraft 01, and placing the buffer support plate 21 directly under the landing gear;

[0063] Step S3, retract the landing gear and place the buffer bag 22 in the center of the buffer support plate 21;

[0064] Step S4, emergency lowering of the landing gear, and locking the landing gear after lowering it into place.

[0065] The explanation of step S1 is required. The basic parameters of the emergency release of the landing gear of aircraft 01 can be obtained through 3D design software such as CATIA. The above basic parameters mainly include the mass m of a single landing gear, the height h of the center of gravity change of a single landing gear, and the distance from the wheel axle to the landing gear shaft. , the distance from the landing gear center of gravity to the landing gear axis , The volume of the inflation chamber of the retractable actuator when the landing gear is retracted to its full position , the air intake volume of the retraction and extension actuator during the emergency extension of the landing gear , the emergency gas system pressure after emergency release , Nitrogen tank volume And the volume of the pipeline cavity .

[0066] The specific method for calculating the mass of the buffer bag 22 is:

[0067] Calculate the gravitational potential energy during the emergency deployment of the landing gear , where m is the mass of a single landing gear, g is the acceleration of gravity, and h is the height of the center of gravity change of a single landing gear;

[0068] Calculate the work done by the emergency air system during emergency deployment of the landing gear ,in, is the initial pressure of the emergency gas system, , It is the pressure of the emergency gas system after emergency release. is the initial volume of the emergency gas system, , is the volume of the emergency gas system after emergency release, , is the insulation coefficient;

[0069] Gravity potential energy during landing gear emergency release The emergency air system works during the emergency release of the landing gear. The kinetic energy of the landing gear after emergency release can be calculated as , and the kinetic energy of the emergency landing gear is close to the final position. ,in, is the emergency rear landing gear extension speed, the emergency rear landing gear extension wheel speed ,

[0070] Based on this, the wheel speed of the emergency rear landing gear can be calculated and equivalent mass ,in, is the distance from the wheel axle to the landing gear axis, is the distance from the landing gear center of gravity to the landing gear axis;

[0071] According to the design residual speed after the wheel impacts the buffer package , through the conservation of momentum and energy conservation Calculate and obtain the mass of the buffer bag 22 ,in, It is the speed of the buffer pack 22 after being impacted.

[0072] It is understandable that the design residual speed after the wheel hits the buffer pack The smaller the value, the smaller the impact load on the aircraft 01 body. Therefore, it is preferred to set the design residual speed after the wheel impacts the buffer pack. .

[0073] It should be explained in step S2 that the structure and size of the aircraft bracket 10 can be determined according to the actual test needs with reference to the existing aircraft bracket, and the setting position of the aircraft bracket 10 needs to be determined according to the structure and size of the aircraft 01 to be tested;

[0074] The aircraft bracket 10 lifts the aircraft 01 to lift the landing gear wheels off the ground. The distance between the wheels and the ground usually needs to be greater than the thickness of the buffer support plate 21, which is usually set to about 5 cm.

[0075] It is necessary to explain step S3 that, since the center of the buffer tray 21 is located directly below the landing gear wheel, the buffer bag 22 is placed in the center of the buffer tray 21 to ensure that after the landing gear is emergency lowered, the wheel collides with the buffer bag 22, thereby absorbing the kinetic energy generated by the emergency lowering of the landing gear.

[0076] It should be noted that step S4 is that after the landing gear is locked, it is necessary to check the locked-in position signal through maintenance equipment, or to manually push and pull the landing gear without shaking to ensure that the landing gear is locked successfully.

[0077] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0078] The electrical dual-redundant all-electric landing gear emergency release test system and test method provided by the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An electrical dual-redundancy all-electric landing gear emergency release test system, characterized in that: include: An aircraft bracket (10) for supporting the fuselage of an aircraft (01) so that the wheels are off the ground; A plurality of buffer assemblies (20) comprising a buffer support plate (21) and a buffer bag (22), wherein the buffer bag (22) is slidably disposed above the buffer support plate (21), and the buffer bag (22) is used to collide with the aircraft wheel to absorb kinetic energy generated by emergency lowering of the landing gear, and the number of the buffer assemblies (20) is the same as the number of the aircraft wheels.

2. The electrical dual-redundancy all-electric landing gear emergency release test system according to claim 1, characterized in that: The outer periphery of the buffer bag (22) is coated with at least one layer of buffer pad (23), and the buffer pad (23) comprises a polyurethane foam pad or a polyethylene foam pad.

3. The electrical dual-redundancy all-electric landing gear emergency release test system according to claim 2, characterized in that: The buffer pad (23) is fixed to the outside of the buffer bag (22) by means of a cable tie, and the cable tie is evenly arranged along the height direction of the buffer bag (22).

4. The electrical dual-redundancy all-electric landing gear emergency release test system according to claim 2, characterized in that: The buffer pad (23) is bonded to the outside of the buffer bag (22), and the buffer pad (23) is bonded to the buffer bag (22) by means of Velcro or glue.

5. The electrical dual-redundancy all-electric landing gear emergency release test system according to any one of claims 1 to 4, characterized in that: The buffer bag (22) comprises a multi-layer woven bag, wherein fine gravel for buffering and absorbing vibration is arranged inside the multi-layer woven bag.

6. The electrical dual-redundancy all-electric landing gear emergency release test system according to any one of claims 1 to 4, characterized in that: At least two intersecting positioning lines (211) are provided on the upper surface of the buffer support plate (21), and the intersection of the positioning lines (211) is located directly below the wheel.

7. The electrical dual-redundancy all-electric landing gear emergency release test system according to claim 6, characterized in that: The buffer support plate (21) comprises a rectangular support plate, and the positioning line (211) is a midline arranged perpendicular to the outer edge of the rectangular support plate.

8. A test method, used for the electrical dual-redundancy all-electric landing gear emergency release test system according to any one of claims 1 to 7, characterized in that: include: The mass of the cushioning bag (22) is determined by calculation based on basic parameters of the emergency release of the landing gear of the aircraft (01); The aircraft (01) is lifted up by using an aircraft bracket (10), and a buffer support plate (21) is placed directly below the landing gear; Retracting the landing gear, and placing the buffer bag (22) in the center of the buffer support plate (21); Emergency release of the landing gear, and after it is fully lowered, locking the landing gear.

9. The test method according to claim 8, characterized in that The method of calculating and determining the mass of the buffer bag (22) according to basic parameters of the emergency release of the landing gear of the aircraft (01) comprises: Calculate the gravitational potential energy during the emergency deployment of the landing gear , where m is the mass of a single landing gear, g is the acceleration of gravity, and h is the height of the center of gravity change of a single landing gear; Calculate the work done by the emergency air system during emergency deployment of the landing gear ,in, is the initial pressure of the emergency gas system, It is the pressure of the emergency gas system after emergency release. is the initial volume of the emergency gas system, is the volume of the emergency gas system after emergency release, is the insulation coefficient; Calculate the wheel speed of the emergency rear landing gear and equivalent mass ,in, is the distance from the wheel axle to the landing gear axis, is the distance from the landing gear center of gravity to the landing gear axis; According to the design residual speed after the wheel impacts the buffer package , through the conservation of momentum and energy conservation Calculate and obtain the mass of the buffer bag (22) ,in, is the speed of the buffer bag (22) after being impacted.

10. The test method according to claim 9, characterized in that: The designed residual speed after the wheel impact buffer package .

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