Aircraft landing gear drop test device and method

Abstract

The application provides a kind of simulation lift method aircraft landing gear drop test device and method, belong to the field of aviation test bed testing, simulation lift actuator in the application adopts no rod pneumatic actuator.The force transmission piston rod in the traditional simulation test method is evolved into a part of the basket, and the simulation lift sensor is also connected with the basket.And for the buffer displacement of the piston rod, it is measured by means of external laser displacement sensor.Through the device provided by the application, the collision mass on the simulation lift actuator during the drop test is greatly reduced, the loss of the power consumption during the test process is effectively reduced, and the drop test precision is significantly improved.The no rod pneumatic actuator used in the device greatly reduces the collision mass on the simulation lift actuator during the drop test, effectively reduces the loss of the power consumption during the test process, and significantly improves the drop test precision.

Description

Technical Field

[0001] The present invention belongs to the field of aviation test bench testing, and specifically relates to an aircraft landing gear drop impact test apparatus and method using the lift simulation method. Background Art

[0002] Most domestic drop impact tests for aircraft landing gears are carried out on column-type test benches. When performing the landing gear drop impact test, the first step is to rotate the wheel against the heading direction to the specified landing speed, and then vertically drop the simulated landing device from a specific height. After being released, the landing gear enters a free-fall state. When the wheel touches the test bench, the measurement and control system will synchronously collect various parameters including the force applied to the landing gear system, the displacement of the center of gravity, the displacement of the buffer strut, as well as the spin-up and springback loads of the landing gear. Based on this, key parameters such as the buffer performance and work absorption efficiency of the landing gear are analyzed, so as to provide relatively reliable data support for the design optimization of the landing gear.

[0003] Publication No. CN119370336A discloses an aircraft landing gear drop impact test apparatus and test method, which relates to the technical field of aircraft landing test devices. The apparatus includes a platform, and a support structure is arranged on the platform; a rack is movably connected with the support structure to move up and down relative to the support structure; moreover, a mounting seat is arranged on the rack to connect the landing gear; a connecting seat is arranged on the platform and disposed below the rack; a test box body is detachably connected to the connecting seat, and the test box body is provided with a first cavity with an upward opening to accommodate pavement materials. The landing gear drop impact test apparatus and test method of the present application can use the first cavity of the test box body to accommodate different pavement materials, so as to form different pavement structures, enabling the present landing gear drop impact test apparatus to conduct simulation tests for various pavement working conditions.

[0004] According to the existing relevant requirements for landing gear ground load drop impact tests, a release test can only be recognized as qualified when both the theoretical work error and the test error of the landing gear are within ±3%. Different from the drop impact test using the reduced aircraft mass method based on energy equivalence adopted by the US military standards, the lift simulation method drop impact test originates from Russian specifications, which adopts the mechanical aircraft lift simulation drop impact test technology, and this technology can more accurately simulate the work absorption condition of the landing gear during the ground contact process. However, during the lift simulation method test, at the moment when the wheel touches the test bench, a lift simulation force peak will be formed and mechanical energy will be lost due to the collision between the released mass and the lift simulation actuator. Under the condition that the error between the test work and the theoretical work is ensured not to exceed ±3%, the error between the release work and the theoretical work is all outside the range of -5% to -7%, and even in some cases the maximum can reach more than -15%. As a result, the test result can hardly meet the test requirements. At this time, no matter how the air pressure inside the lift simulation actuator cylinder is adjusted, the error cannot reach the standard range required by the test. Contents of the Invention

[0005] To overcome the problem that existing methods, regardless of adjusting the air pressure inside the lift-simulating actuator, cannot bring the error within the required standard range for testing, this invention provides a lift-simulating aircraft landing gear drop test apparatus and method. In this invention, the lift-simulating actuator is a rodless pneumatic actuator. The force-transmitting piston rod in traditional lift-simulating test methods is transformed into part of the basket, and the lift sensor is also connected to the basket. Furthermore, the buffer displacement of the piston rod is measured using an external laser displacement sensor. The apparatus provided by this invention significantly reduces the impact mass on the lift-simulating actuator during drop testing, effectively reducing the loss of power during the test, thereby significantly improving the accuracy of the drop test.

[0006] The technical solution adopted in this invention is as follows: A lift-simulation method aircraft landing gear drop test device includes a main column, a lifting device, a guide frame device, a basket, a wheel-driven rotation device, lift-simulation actuators, landing gear, a three-dimensional force measuring platform, and a ground rail. The lifting device is installed on top of the main column, and the guide frame device is located directly below the lifting device and is rotatably connected to the main column. The basket is located below the guide frame device and is rotatably connected to the main column. The basket is locked and released by a locking device on the guide frame device. The landing gear is connected to the bottom surface of the basket. The three-dimensional force measuring platform is fixedly installed on the ground rail. The wheel-driven rotation device is installed on the ground rail in the same direction as the aircraft. Multiple lift-simulation actuators are included, each fixedly connected to the ground rail and each fixedly installed to the bottom surface of the basket via corresponding combined cylinder rods.

[0007] The aforementioned lifting-simulating actuator includes a combined cylinder rod, a lifting force sensor, a positioning cap, a laser displacement sensor, a piston, an actuator body, and an actuator base. The piston and the combined cylinder rod are designed separately, with the piston located inside the actuator body and the combined cylinder rod located above the actuator body. The upper part of the combined cylinder rod is connected to the bottom surface of the suspended platform via the lifting force sensor. The actuator body is mounted on the actuator base, the positioning cap is located on the top of the actuator body, and the laser displacement sensor is fixedly installed on the upper part of the actuator body.

[0008] The combined cylinder rod includes a cylinder rod body and a spherical pad. The piston end face of the imitation lifting actuator is designed with a hemispherical groove, which cooperates with the spherical pad. The spherical pad and the cylinder rod body are positioned through positioning holes and fixedly connected with screws.

[0009] The spherical pad is a non-metallic organic cushioning material with adjustable thickness.

[0010] The thickness-adjustable non-metallic organic cushioning material is made of nylon, polyurethane, or rubber.

[0011] The upper part of the combined cylinder rod is connected to the simulated lift sensor via threads, and the simulated lift sensor is installed on the bottom surface of the suspended platform by bolts.

[0012] The upper end of the actuating cylinder has a positioning cap with an interchangeable height. By replacing the positioning cap with one of different heights, the vertical position of the piston can be changed.

[0013] The main column is surrounded by walkways and guardrails in layers.

[0014] The guide frame device includes a guide frame body, a locking device, a lifting ring, and a guide roller assembly. The locking device, the lifting ring, and the guide roller assembly are all located on the guide frame body. The guide frame body is rolledly connected to the sliding plate on the main column through the guide roller assembly. The suspended basket is rolledly connected to the sliding plate on the main column through roller bearings. The suspended basket is locked and released by the locking device.

[0015] A method for testing the landing gear of an aircraft using a lift-simulation method includes the following steps: First, the lifting device controls the guide frame device to descend slowly. Since the basket and the guide frame device are connected together by a locking device, the basket will drive the landing gear installed on its bottom surface to descend together. When the landing gear wheels of the landing gear contact the upper surface of the three-dimensional force measuring platform, the height of the positioning cover is adjusted so that the lower spherical pad of the combined cylinder rod just contacts the upper hemispherical groove of the piston. Then, the position of the laser displacement sensor is zeroed; the simulated lift sensor is zeroed; the landing gear is raised to the required drop height by the lifting device; the wheel drive wheel of the wheel drive device is fed along the heading and pressed against the wheel; after the wheel drive wheel of the wheel drive device is fed into position, it begins to rotate under the drive of the motor of the wheel drive device until it reaches the required speed for the test and then quickly retracts; when the wheel drive wheel of the wheel drive device retracts into position, a release command is sent to the locking device, and the basket together with the landing gear performs free fall motion in the vertical direction; When the landing gear reaches the contact position, the combined cylinder rod also contacts the piston, initiating the lift simulation stroke. As the landing gear continues to descend, the combined cylinder rod continuously pushes the piston downward until the landing gear speed drops to zero and enters the rebound stroke. During this process, the lift simulation force and compression displacement are collected in real time by the lift simulation force sensor and the laser displacement sensor. The lift simulation force and compression displacement data are used to calculate the lift power of the aircraft during the test. The calculated power value is used to adjust the air pressure value in the lift simulation actuator until the lift simulation power reaches the error range required by the test. The above completes one simulated lift drop test. If you need to repeat the test, simply repeat the above test steps.

[0016] The beneficial effects of this invention are: This invention, by separating the piston and piston rod of the simulated lift actuator, transfers the moving mass of the piston rod, simulated lift sensor, etc., in traditional technology to part of the basket. The beneficial result is that the mass of the moving parts of the simulated lift actuator is greatly reduced. According to the principle of conservation of momentum and mechanical energy of the collision system during the drop test, the loss of mechanical energy after the collision will be significantly reduced compared with the existing technology, thereby ensuring the precise control of the simulated lift power and the release power.

[0017] In this invention, the simulated lift actuator uses a rodless pneumatic actuator. The force-transmitting piston rod in traditional simulated lift testing methods is transformed into part of the suspended basket, and the simulated lift sensor is also connected to the basket. Furthermore, the buffer displacement of the piston rod is measured using an external laser displacement sensor.

[0018] The rodless pneumatic actuator in this device significantly reduces the collision mass on the imitation lifting actuator during the drop test, effectively reducing the loss of power input during the test, thereby significantly improving the accuracy of the drop test.

[0019] In this invention, the collision contact area between the combined cylinder rod and piston employs spherical self-positioning technology, avoiding power loss caused by increased friction due to uneven loading of the piston during the simulated lift drop test. Simultaneously, the end of the combined cylinder rod utilizes a vibration-damping spherical pad, which significantly reduces the peak contact force at the moment of collision, further improving the measurement accuracy of the simulated lift power.

[0020] In this invention, the position of the piston inside the lifting actuator is adjusted by a positioning cap to adapt to the position of the lifting force at different deployment heights. This method is flexible, reliable, and easy to operate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the simulated drop test device.

[0022] Figure 2 This is a diagram showing the layout of the simulated lift actuator within the drop test platform.

[0023] Figure 3 This is a diagram showing the state of the actuator cylinder before it touches the platform.

[0024] Figure 4 This is a diagram showing the state of the piston in the imitation lifting actuator cylinder after compression following contact with the platform.

[0025] Figure 5 This is a schematic diagram of a combined cylinder rod structure.

[0026] Figure 6 This is a schematic diagram of the piston's initial position adjustment.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings.

[0028] In the figure, the attached figures are labeled as follows: 1. Main column; 2. Lifting device; 3. Walkway and guardrail; 4. Guide frame device; 5. Suspended basket; 6. Wheel drive device; 7. Lifting actuator; 8. Landing gear; 9. Three-dimensional force measuring platform; 10. Ground rail; 401 Guide frame body; 402 Locking device; 403 Lifting ring; 404 Guide roller assembly; 501. Counterweight; 502. Roller bearing; 71. Cylinder rod body; 72. Spherical gasket; 73. Positioning hole; 701. Combined cylinder rod; 702. Lift sensor; 703. Positioning gland; 704. Laser displacement sensor; 705. Piston; 706. Actuator cylinder body; 707. Actuator cylinder base; 708. Flange; 801. Wheels. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0031] Example 1: To overcome the problem that existing methods, regardless of how the air pressure inside the simulated lifting actuator is adjusted, cannot bring the error within the standard range required for testing, this invention provides... Figure 1-6 This invention discloses a lift-simulation aircraft landing gear drop test apparatus and method. In this invention, the lift-simulation actuator uses a rodless pneumatic actuator. The force-transmitting piston rod in traditional lift-simulation testing methods is transformed into part of the basket, and the lift sensor is also connected to the basket. Furthermore, the buffer displacement of the piston rod is measured using an external laser displacement sensor. The apparatus provided by this invention significantly reduces the impact mass on the lift-simulation actuator during drop testing, effectively reducing the loss of power during the test, thereby significantly improving the accuracy of the drop test.

[0032] A lift-simulation method aircraft landing gear drop test device includes a main column 1, a lifting device 2, a guide frame device 4, a basket 5, a wheel-driven rotating device 6, lift-simulation actuators 7, landing gear 8, a three-dimensional force measuring platform 9, and a ground rail 10. The lifting device 2 is installed on top of the main column 1, and the guide frame device 4 is located directly below the lifting device 2 and is rotatably connected to the main column 1. The basket 5 is located below the guide frame device 4 and is rotatably connected to the main column 1. The basket 5 is locked and released by a locking device 402 on the guide frame device 4. The landing gear 8 is connected to the bottom surface of the basket 5. The three-dimensional force measuring platform 9 is fixedly installed on the ground rail 10. The wheel-driven rotating device 6 is installed on the ground rail 10 in the same direction as the aircraft. There are multiple lift-simulation actuators 7, each fixedly connected to the ground rail 10 and fixedly installed to the bottom surface of the basket 5 by corresponding combined cylinder rods 701.

[0033] like Figure 1 and Figure 2 As shown, in this invention, the main column 1 is fixedly installed on the ground foundation, the lifting device 2 is installed on the top of the main column 1, and the lifting device 2 is connected to the lifting ring 403 on the guide frame device 4 via a hook. The walkway and guardrail 3 are arranged in layers along the periphery of the main column 1. The guide frame device 4 is rolledly connected to the sliding plate on the main column 1 via a guide roller assembly 404. The basket 5 is rolledly connected to the sliding plate on the main column 1 via a roller bearing 502. The basket 5 is locked and released in a controllable manner via a locking device 402. The landing gear 8 is connected to the bottom surface of the basket device via bolts. The three-dimensional force measuring platform 9 is fixedly installed on the ground rail 10, and the wheel-driven rotation device 6 is installed on the ground rail 10 in the same direction as the flight path. The main column 1 includes four columns forming a rectangular body fixed on the ground foundation. The guide frame device 4 and the basket 5 are both located within the rectangular body formed by the four columns and can roll up and down along the columns. There are four sets of lifting actuators 7, each fixedly connected to the ground rail 10 via an actuator base 707. The combined cylinder rod 701 of the lifting actuator 7 is fixedly installed to the bottom surface of the suspended platform 5. A counterweight 501 is placed inside the suspended platform 5 as needed. The four sets of lifting actuators 7 are arranged in a rectangular shape and located below the suspended platform 5. All four sets of lifting actuators 7 are located within the rectangle formed by four columns. The landing gear 8 is located in the middle of the four sets of lifting actuators 7, and its upper end is connected to the suspended platform 5.

[0034] The lifting device 2, locking device 402, and wheel-driven rotation device 6 in this invention are all existing mature technologies, and will not be further described in this invention. The lifting device 2 only needs to ensure the vertical lifting of the suspended platform 5. The locking device 402 in this invention can lock and release the suspended platform 5 through the control system.

[0035] The invention also includes a control system, which is electrically connected to the lifting device 2, the locking device 402, the wheel drive device 6, and the imitation lifting actuator 7. The entire device is electrically controlled by the control system.

[0036] The working principle of this invention is as follows: During the landing gear drop test, when the locking device 402 releases the basket 5, the basket 5, together with the landing gear 8 and the combined cylinder rod 701, undergoes free fall. By adjusting the length of the positioning cover 703, it is ensured that when the wheel 801 contacts the three-dimensional force measuring platform 9, the spherical pad 72 also contacts the groove on the piston 705. As the basket 5 continues to fall, the piston 705 is pushed downward to compress the compressed air below the lift-simulating actuator 7. Since the inlet of the lift-simulating actuator 7 is connected to a large-capacity compressed air tank, the piston 705 is subjected to an approximately constant lift force. This force does work on the landing gear's buffering process during the drop test, which can accurately simulate the aircraft's lift effect.

[0037] In this invention, the lift-simulating actuator 7 is a rodless pneumatic actuator. The force-transmitting piston rod in traditional lift-simulating test methods is transformed into part of the basket 5, and the lift-simulating force sensor is also connected to the basket 5. Furthermore, the buffer displacement of the piston rod (combined cylinder rod 701) is measured using an external laser displacement sensor 704. The device provided by this invention significantly reduces the impact mass on the lift-simulating actuator 7 during drop tests, effectively reducing the loss of power input during the test, thereby significantly improving the accuracy of drop tests.

[0038] Example 2: Based on Embodiment 1, in this embodiment, preferably, the simulated lifting actuator 7 includes a combined cylinder rod 701, a simulated lifting sensor 702, a positioning cap 703, a laser displacement sensor 704, a piston 705, an actuator cylinder body 706, and an actuator cylinder base 707. The piston 705 and the combined cylinder rod 701 are designed separately. The piston 705 is located inside the actuator cylinder body 706, and the combined cylinder rod 701 is located above the actuator cylinder body 706. The upper part of the combined cylinder rod 701 is connected to the bottom surface of the suspended basket 5 through the simulated lifting sensor 702. The actuator cylinder body 706 is disposed on the actuator cylinder base 707, the positioning cap 703 is disposed on the top of the actuator cylinder body 706, and the laser displacement sensor 704 is fixedly installed on the upper part of the actuator cylinder body 706.

[0039] In this invention, both the simulated lift sensor 702 and the laser displacement sensor 704 are connected to the electrical signals of the control system.

[0040] In this invention, the simulated lifting actuator 7 is a piston-rod-less design. Only the piston 705 and the actuator body 706 cooperate within the simulated lifting actuator 7. The piston 705 is made of lightweight aluminum or magnesium alloy, and hemispherical grooves are designed at the geometric center of its upper and lower end faces. The vertical position of the piston 705 within the simulated lifting actuator 7 is adjusted by the positioning cap 703. By changing the height of the positioning cap 703 according to the drop height requirements of the drop test, the contact position between the spherical pad at the bottom of the combined cylinder rod 701 and the piston 705 can be altered.

[0041] In this invention, a laser displacement sensor 704 is fixedly installed on the upper part of the actuating cylinder 706, which can measure the compression displacement value of the piston 705 in real time.

[0042] This invention separates the piston 705 and piston rod (combined cylinder rod 701) of the lifting actuator 7, transferring the moving mass of the piston rod, lifting sensor 702, etc., in the traditional technology to a part of the basket 5. The beneficial result is that the mass of the moving parts of the lifting actuator 7 is greatly reduced. According to the principle of conservation of momentum and mechanical energy of the collision system during the drop test, the loss of mechanical energy after the collision will be significantly reduced compared with the existing technology, thereby ensuring the precise control of the lifting power and the release power. This device can better demonstrate its unique advantages.

[0043] Preferably, the upper end of the actuating cylinder body 706 has a positioning cover 703 with a height-replaceable dimension. By replacing the positioning cover 703 with different heights, the vertical position of the piston 705 can be changed.

[0044] In this invention, such as Figure 3 and Figure 6 As shown, the actuator cylinder 706 has a flange 708 at its bottom. The upper end of the actuator cylinder 706 has a height-adjustable positioning cap 703. By changing the positioning cap 703 to different heights, the vertical position of the piston 705 can be altered, thus adapting to the effective position of the simulated lift force during drop tests at different drop heights. A laser displacement sensor 704 is installed on the upper part of the actuator cylinder 706 to measure the vertical displacement of the piston as it is pressed down by the combined cylinder rod 701, in order to calculate the work done by the simulated lift force during the drop test. The position of the piston 705 inside the simulated lift actuator cylinder 7 is adjusted by the positioning cap 703 to adapt to the position of the simulated lift force at different drop heights. This method is flexible, reliable, and easy to operate.

[0045] Preferably, the combined cylinder rod 701 includes a cylinder rod body 71 and a spherical pad 72. The piston 705 of the imitation lifting actuator 7 is designed with a hemispherical groove on its end face. The groove cooperates with the spherical pad 72. The spherical pad 72 and the cylinder rod body 71 are positioned through a positioning hole 73 and fixedly connected with screws.

[0046] Preferably, the spherical pad 72 is a non-metallic organic cushioning material with adjustable thickness.

[0047] Preferably, the thickness-adjustable non-metallic organic cushioning material is made of nylon, polyurethane, or rubber.

[0048] In this invention, such as Figure 5 As shown, the combined cylinder rod 701 includes a cylinder rod body 71, a spherical pad 72, and a positioning hole 73. The spherical pad 72 is a non-metallic organic buffer material with adjustable thickness, which effectively reduces vibration and can greatly buffer the impact load peaks during the simulated drop vibration test.

[0049] In this invention, the collision contact area between the combined cylinder rod 701 and the piston 705 adopts spherical self-positioning technology, which can avoid the power loss caused by increased friction due to uneven loading of the piston during the simulated lift drop test. At the same time, the end of the combined cylinder rod 701 adopts a vibration-damping spherical pad 72, which can significantly reduce the peak contact force at the moment of collision, and further improve the measurement accuracy of the simulated lift power.

[0050] In this invention, a hemispherical groove is designed on the end face of the piston 705 of the imitation lifting actuator 7. The groove cooperates with the spherical pad 72 to effectively guide the drop lifting force buffering process, ensuring that the piston 705 is subjected to uniform force and the pressing process is smooth.

[0051] Preferably, the upper part of the combined cylinder rod 701 is connected to the simulated lift sensor 702 by threads, and the simulated lift sensor 702 is installed on the bottom surface of the basket 5 by bolts.

[0052] In this invention, the piston 705 and the combined cylinder rod 701 of the lifting actuator 7 are designed separately. The upper part of the combined cylinder rod 701 is connected to the lifting force sensor 702 by threads, and the lifting force sensor 702 is bolted to the bottom surface of the suspended basket 5. The lifting force sensor 702 is provided with bolt mounting holes for easy disassembly.

[0053] Preferably, the outer perimeter of the main column 1 is provided with walkways and guardrails 3 in layers.

[0054] Preferably, the guide frame device 4 includes a guide frame body 401, a locking device 402, a lifting ring 403, and a guide roller assembly 404. The locking device 402, the lifting ring 403, and the guide roller assembly 404 are all mounted on the guide frame body 401. The guide frame body 401 is rolledly connected to the sliding plate on the main column 1 through the guide roller assembly 404. The suspended basket 5 is rolledly connected to the sliding plate on the main column 1 through a roller bearing 502. The suspended basket 5 is locked and released by the locking device 402.

[0055] Example 3: Based on Embodiment 1 or 2, this embodiment provides a method for testing the landing gear drop of an aircraft using a lift-simulation method. The specific steps are as follows: First, the lifting device 2 controls the guide frame device 4 to descend slowly. Since the basket 5 and the guide frame device 4 are connected together through the locking device 402, the basket 5 will drive the landing gear 8 installed on its lower surface to descend together. When the landing gear wheel 801 of the landing gear 8 contacts the upper surface of the three-way force measuring platform 9, the height of the positioning cover 703 is adjusted so that the lower end spherical pad 72 of the combined cylinder rod 701 just contacts the upper end hemispherical groove of the piston 705. Then, the position of the laser displacement sensor 704 is zeroed; the simulated lift sensor 702 is zeroed; the landing gear 8 is lifted to the required drop height by the lifting device 2; the wheel drive device 6 feeds along the heading and is pressed against the wheel 801; after the wheel drive device 6 is fed into position, it starts to rotate under the drive of the motor of the wheel drive device 6 until it reaches the required speed for the test and then quickly retracts; when the wheel drive is retracted into position, a release command is sent to the locking device 402, and the basket 5 together with the landing gear 8 performs free fall motion in the vertical direction; When the landing gear 801 reaches the contact position, the combined cylinder rod 701 also contacts the piston 705, initiating the power stroke of the simulated aircraft lift. As the landing gear 8 continues to descend, the combined cylinder rod 701 continuously pushes the piston 705 downward until the speed of the landing gear 8 decreases to zero and enters the rebound stroke. During this process, the simulated lift force and compression displacement are collected in real time by the simulated lift force sensor 702 and the laser displacement sensor 704. The power of the aircraft lift during the test is calculated based on the collected simulated lift force and compression displacement data. The air pressure value in the simulated lift actuator 7 is adjusted based on the calculated power value until the simulated lift power reaches the error range required by the test. The above completes one simulated lift drop test. If you need to repeat the test, simply repeat the above test steps.

[0056] In this invention, the wheel-driven rotating device 6 includes at least a rotating pulley and a motor. The motor drives the rotating pulley and is connected to the control system via electrical signals. The wheel-driven rotating device 6 is a mature existing technology and will not be further described in this invention.

[0057] In this invention, the work done by the simulated lift force has both theoretical and experimental values. Based on theoretical calculations, the air pressure value inside the simulated lift actuator 7 is initially set. During the experiment, the simulated lift work is corrected and adjusted based on the experimental results after data collection and processing. If the results show that the simulated lift work exceeds the theoretical work and the error exceeds the allowable value, it indicates that the simulated lift work is too much, and the air pressure inside the simulated lift actuator 7 should be reduced accordingly. Conversely, the air pressure needs to be increased.

[0058] In this invention, the simulated lifting actuator cylinder is in the state before touching the platform, as shown in the following example. Figure 3As shown; when the wheel 801 reaches the contact position, the combined cylinder rod 701 also contacts the piston 705. After contacting the contact position, the piston of the imitation lifting actuator is compressed as shown. Figure 4 As shown.

[0059] Compared with traditional simulated lift drop test devices, this invention has the advantages of convenient anti-lift force adjustment, precise control of simulated lift power, and less power loss caused by mechanical friction. It can ensure that the system power error and the power delivery error are both within the range specified in the standard during the simulated lift drop test.

[0060] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0062] The examples above are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention fall within the scope of protection of the present invention. Device structures and method steps not described in detail in this invention are prior art and will not be further described in this invention.

Claims

1. A landing gear drop test device for aircraft using a lift-simulation method, characterized in that: The system includes a main column (1), a lifting device (2), a guide frame device (4), a suspended platform (5), a wheel drive device (6), a lifting actuator (7), a landing gear (8), a three-dimensional force measuring platform (9), and a ground rail (10). The lifting device (2) is installed on top of the main column (1), and the guide frame device (4) is located directly below the lifting device (2). The guide frame device (4) is rotatably connected to the main column (1). The suspended platform (5) is located on the guide frame device (6). 4) The lower part is connected to the main column (1) in a rolling manner. The basket (5) is locked and released by the locking device (402) on the guide frame device (4). The landing gear (8) is connected to the bottom surface of the basket (5). The three-dimensional force measuring platform (9) is fixedly installed on the ground rail (10). The wheel drive device (6) is installed on the ground rail (10) in the direction of flight. There are multiple imitation lift actuators (7). All multiple imitation lift actuators (7) are fixedly connected to the ground rail (10). All actuators (7) are fixedly installed on the bottom surface of the basket (5) via corresponding combined cylinder rods (701); the simulated lifting actuator (7) includes a combined cylinder rod (701), a simulated lifting sensor (702), a positioning cover (703), a laser displacement sensor (704), a piston (705), an actuator body (706), and an actuator base (707). The piston (705) and the combined cylinder rod (701) are designed separately, and the piston (705) is located at the actuation point. Inside the cylinder body (706), the combined cylinder rod (701) is located above the actuating cylinder body (706), and the upper part of the combined cylinder rod (701) is connected to the bottom surface of the basket (5) through the simulated lift sensor (702); the actuating cylinder body (706) is located on the actuating cylinder base (707), the positioning cover (703) is located on the top of the actuating cylinder body (706), and the laser displacement sensor (704) is fixedly installed on the upper part of the actuating cylinder body (706).

2. The landing gear drop test device for aircraft using the simulated lift method according to claim 1, characterized in that: The combined cylinder rod (701) includes a cylinder rod body (71) and a spherical pad (72). The piston (705) of the imitation lifting actuator (7) has a hemispherical groove on its end face. The groove cooperates with the spherical pad (72). The spherical pad (72) and the cylinder rod body (71) are positioned by a positioning hole (73) and fixedly connected by screws.

3. The landing gear drop test device for aircraft using the simulated lift method according to claim 2, characterized in that: The spherical pad (72) is a non-metallic organic cushioning material with adjustable thickness.

4. The landing gear drop test device for aircraft using the lift simulation method according to claim 3, characterized in that: The thickness-adjustable non-metallic organic cushioning material is made of nylon, polyurethane, or rubber.

5. The landing gear drop test device for aircraft using the simulated lift method according to claim 1, characterized in that: The upper part of the combined cylinder rod (701) is connected to the simulated lift sensor (702) by threads, and the simulated lift sensor (702) is installed on the bottom surface of the basket (5) by bolts.

6. The landing gear drop test apparatus for aircraft using the simulated lift method according to claim 1, characterized in that: The upper end of the actuating cylinder body (706) has a positioning cover (703) with a height that can be changed. By changing the positioning cover (703) of different heights, the vertical position of the piston (705) can be changed.

7. The landing gear drop test device for aircraft using the simulated lift method according to claim 1, characterized in that: The main column (1) is surrounded by walkways and guardrails (3) in layers.

8. The landing gear drop test device for aircraft using the lift simulation method according to claim 1, characterized in that: The guide frame device (4) includes a guide frame body (401), a locking device (402), a lifting ring (403), and a guide roller assembly (404). The locking device (402), the lifting ring (403), and the guide roller assembly (404) are all located on the guide frame body (401). The guide frame body (401) is connected to the sliding plate on the main column (1) via the guide roller assembly (404). The basket (5) is connected to the sliding plate on the main column (1) via the roller bearing (502). The basket (5) is locked and released via the locking device (402).

9. The test method of the simulated lift aircraft landing gear drop test apparatus according to any one of claims 1-8, characterized in that: The specific steps are as follows: First, the lifting device (2) controls the guide frame device (4) to descend slowly. Since the basket (5) and the guide frame device (4) are connected together through the locking device (402), the basket (5) will drive the landing gear (8) installed on its bottom surface to descend together. When the landing gear wheel (801) of the landing gear (8) contacts the upper surface of the three-way force measuring platform (9), the height of the positioning cover (703) is adjusted so that the lower end spherical pad (72) of the combined cylinder rod (701) just contacts the upper end hemispherical groove of the piston (705). Then, the position of the laser displacement sensor (704) is zeroed; the simulated lift sensor (702) is zeroed; the landing gear (8) is lifted to the required drop height by the lifting device (2); the wheel drive device (6) feeds along the heading and is pressed against the wheel (801); after the wheel drive device (6) is fed into position, it starts to rotate under the drive of the motor of the wheel drive device (6) until it reaches the required speed for the test and then quickly retracts; when the wheel drive device (6) retracts into position, it sends a release command to the locking device (402); the basket (5) together with the landing gear (8) performs free fall in the vertical direction. When the wheel (801) reaches the contact position, the combined cylinder rod (701) also contacts the piston (705), starting the power stroke that simulates the lift of an aircraft; as the landing gear (8) continues to sink, the combined cylinder rod (701) continues to push the piston (705) downward until the speed of the landing gear (8) drops to zero and enters the rebound stroke. In this process, the lift force and compression displacement are collected in real time by the lift sensor (702) and the laser displacement sensor (704). The lift force and compression displacement data collected are used to calculate the lift power of the aircraft during the test. The air pressure value in the lift actuator (7) is adjusted according to the calculated power value until the lift power reaches the error range required by the test. The above completes one simulated lift drop test. If you need to repeat the test, simply repeat the above test steps.

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