Airplane main landing gear ground joint debugging comprehensive experiment table

Abstract

The utility model provides an airplane main landing gear ground joint debugging comprehensive experiment table, including bottom frame, the top of bottom frame is supported and is installed with top frame through stand, the top of top frame is fixed with top platform, the bottom end surface of top frame is fixed with main hanging point for hinged landing gear, the inside side end surface of top frame is fixed with front hanging point, the lateral wall of landing gear is hinged with the retraction and extension actuator cylinder, the top of retraction and extension actuator cylinder is hinged in the bottom end of top frame through retraction and extension actuator cylinder hanging point, and the front hanging point and landing gear are hinged with cross axle, disturbance measuring rod and bracing piece, the inside lateral wall on the lower part of stand is installed with the positioning inspection device for measuring the wheel shaft height of machine wheel. This experiment table can be used for the comprehensive experiment of airplane main landing gear, and then the performance of airplane main landing gear is verified, so that it can satisfy the actual use demand of follow -up, and then guarantee its reliability.

Description

Technical Field

[0001] This utility model relates to the field of aviation equipment manufacturing, and in particular to a ground-based integrated testing platform for aircraft main landing gear. Background Technology

[0002] During the maintenance of aircraft main landing gear, performance verification is required to ensure its performance. This verification process necessitates checks on the main landing gear wheel axle position, altitude, and retraction smoothness. However, currently, there is no dedicated integrated testing platform. Therefore, a suitable and specific testing platform needs to be designed. Utility Model Content

[0003] The purpose of this invention is to provide a ground-based integrated test bench for the main landing gear of an aircraft. This test bench can be used for integrated testing of the main landing gear of an aircraft, thereby verifying the performance of the main landing gear and ensuring that it meets the requirements of subsequent actual use, thus guaranteeing its reliability.

[0004] To achieve the aforementioned technical features, the present invention aims to provide the following: an integrated test bench for ground-based main landing gear testing of an aircraft, comprising a bottom frame, a top frame supported by columns at the top of the bottom frame, a top platform fixed to the top of the top frame, a main mounting point for hinged landing gear fixed to the bottom end face of the top frame, a front mounting point fixed to the inner side end face of the top frame, a retraction actuator hinged to the side wall of the landing gear, the top of the retraction actuator hinged to the bottom end of the top frame via the retraction actuator mounting point, a horizontal axis, a deflection measuring rod, and a strut hinged between the front mounting point and the landing gear; and a positioning and inspection device for measuring the wheel axle height of the aircraft wheels is installed on the lower inner side wall of the columns.

[0005] Preferably, a diagonal reinforcing bar is fixed between the column and the bottom frame.

[0006] Preferably, a reinforcing crossbeam is fixed to the upper part of the column; The top of the platform is secured with a platform railing around its perimeter.

[0007] Preferably, it also includes a matching climbing ladder structure, the climbing ladder structure including a climbing ladder base, a climbing ladder frame fixed to the top of the climbing ladder base, a ladder step plate provided on the climbing ladder frame, side guardrails symmetrically fixed on both sides of the climbing ladder frame, and a climbing ladder top plate fixed to the top of the climbing ladder frame, the climbing ladder top plate being flush with the top platform.

[0008] Preferably, the top plate of the ladder is fixed with a top guardrail, the bottom four corners of the ladder base are fixed with casters, and the bottom of the ladder base is equipped with screw support feet.

[0009] Preferably, the positioning inspection device includes a horizontal bar fixed on the inner wall of the column, a diagonal brace fixed between the horizontal bar and the column, a positioning plate fixed at the end of the horizontal bar, a positioning shaft fixed at the end of the positioning plate, and the positioning shaft being matched with the position of the wheel axle.

[0010] Preferably, it also includes a supporting main landing gear hydraulic system, which includes two main landing gear retraction and extension control systems, left and right, which are connected to the hydraulic interfaces of the main landing gear through hydraulic conduits to form a hydraulic control circuit. The system pressure is provided by a hydraulic pump station to realize the retraction and extension of the main landing gear.

[0011] Preferably, the single left and right main landing gear retraction control system includes a check valve connected to the hydraulic interface of the main landing gear. The check valve is connected to the main landing gear retraction actuator and the main landing gear retraction mini actuator via a solenoid directional valve. An upper lock is installed on the rodless chamber circuit of the main landing gear retraction actuator, and a throttle valve is installed on the rod chamber circuit of the main landing gear retraction mini actuator.

[0012] Preferably, the bottom end of the bottom frame and the side of the retraction actuator cylinder hanging point are provided with an upper locking point and a support rod hanging point.

[0013] The present invention has the following beneficial effects: 1. This utility model features a compact and well-integrated ground-based integrated testing platform for landing gear. The front and main landing gears are integrated into a single layout, sharing a common hydraulic power source and control system, saving space and resources. It is equipped with tool cabinets and auxiliary ladders for personnel to store and use tools, improving testing efficiency.

[0014] 2. The main lifting frame of this utility model serves as the base of the entire frame. It is constructed by welding Q355 carbon steel square tubing (200mm×200mm×10mm and 160mm×160mm×10mm) and steel plates, providing sufficient rigidity and strength. After welding, stress-relief annealing is performed to eliminate internal welding stress, ensuring the overall dimensional stability of the frame. The entire frame weighs 10.5 tons. To ensure the stability of the main frame, part of the frame's base is installed 300mm into the pit and secured with expansion bolts, improving the stability of the main lifting gear during deployment and retraction operations.

[0015] 3. The main lifting frame of this utility model adopts an open-top structure, leaving space at the top. This facilitates hoisting, allowing for the entire landing gear to be lifted using an overhead crane. It is suitable not only for landing gear with wheels but also for landing gear without wheels. After the operator pushes the main landing gear into the frame, a gantry crane can be used to lift the main landing gear and secure it to the anchor points, facilitating operation. 4. The fixture position of the main landing gear test bench of this utility model is mainly adapted to the nose landing gear mounting points, and mainly includes the main mounting point, nose mounting point, retraction actuator mounting point, upper lock mounting point, and strut mounting point. A set of mounting points is distributed on each side, symmetrically arranged, allowing the main landing gear to be mounted on both sides for separate testing. Each mounting point is fixed to the frame with positioning bolts. The coordinate position of the mounting points is measured and determined using a laser tracker to ensure consistency with the installation coordinate position on the aircraft. While meeting the mechanical interface size and geometric tolerance requirements, the positional error of the mechanical interface points is less than SΦ0.3. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a first-person perspective 3D view of the present invention.

[0018] Figure 2 This is a two-dimensional view of the present invention from a second perspective.

[0019] Figure 3 This is a three-dimensional view of the present invention from a third perspective.

[0020] Figure 4 This is a four-dimensional view of the present invention.

[0021] Figure 5 This is a hydraulic diagram of the left and right main landing gear retraction and extension control system of this utility model.

[0022] Figure 6 This is a three-dimensional structural diagram of the deflection measuring rod of this utility model.

[0023] In the diagram: 1. Bottom frame; 2. Column; 3. Diagonal reinforcing bar; 4. Diagonal brace; 5. Positioning plate; 6. Crossbar; 7. Wheel; 8. Positioning shaft; 9. Reinforcing beam; 10. Top platform; 11. Top frame; 12. Platform railing; 13. Wheel axle; 14. Landing gear; 15. Screw support foot; 16. Ladder base; 17. Ladder step; 18. Ladder frame; 19. Side railing; 20. Ladder top plate; 21. Retraction actuator; 22. Deflection measuring rod; 23. Front mounting point; 24. Retraction actuator mounting point; 25. Upper lock mounting point; 26. Support rod mounting point. Main lifting and retraction actuator 101, upper position lock 102, throttle valve 103, main lifting and retraction small actuator 104. Detailed Implementation

[0024] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0025] See Figure 1-4The aircraft main landing gear ground-based integrated testing bench includes a bottom frame 1. A top frame 11 is mounted on top of the bottom frame 1 via a column 2. A top platform 10 is fixed to the top of the top frame 11. A main mounting point 27 for hinged landing gear 14 is fixed to the bottom end face of the top frame 11. A front mounting point 23 is fixed to the inner side end face of the top frame 11. A retraction actuator 21 is hinged to the side wall of the landing gear 14. The top of the retraction actuator 21 is hinged to the bottom end of the top frame 11 via a retraction actuator mounting point 24. A horizontal axis 29, a deflection measuring rod 22, and a support rod 28 are hinged between the front mounting point 23 and the landing gear 14. A positioning and inspection device for measuring the height of the wheel axle 13 of the wheels 7 is installed on the lower inner side wall of the column 2. This testing bench can be used for integrated testing of the aircraft main landing gear, thereby verifying the performance of the main landing gear to meet subsequent practical use requirements and ensuring its reliability. The main lifting frame is mainly used for measuring the deflection of the main landing gear, checking the wheel axle position, and checking the height of a certain aircraft model.

[0026] Preferably, a diagonal reinforcing rod 3 is fixed between the column 2 and the bottom frame 1. The diagonal reinforcing rod 3 enhances the structural strength and stability of the column 2.

[0027] Preferably, the main frame is the base of the entire frame and is made of Q355 carbon steel square tubes welded together. It has sufficient rigidity and strength. After welding, it is subjected to stress-relief annealing to eliminate internal welding stress and ensure the overall dimensional stability of the frame.

[0028] Preferably, a reinforcing beam 9 is fixed to the upper part of the column 2. The reinforcing beam 9 enhances the structural strength and stability of the column 2.

[0029] Preferably, a platform guardrail 12 is fixed around the top of the top platform 10. The platform guardrail 12 is installed on the top of the top platform 10 to provide safety protection for operators working on the frame.

[0030] Preferably, the system also includes a matching ladder structure. The ladder structure includes a ladder base 16, a ladder frame 18 fixed to the top of the ladder base 16, step plates 17 on the ladder frame 18, side guardrails 19 symmetrically fixed to both sides of the ladder frame 18, and a ladder top plate 20 fixed to the top of the ladder frame 18, which is flush with the top platform 10. This ladder structure facilitates subsequent workers' access to the top platform 10.

[0031] Preferably, the top plate 20 of the ladder is fixed with a top guardrail 31, the bottom four corners of the ladder base 16 are fixed with casters 30, and the bottom of the ladder base 16 is equipped with screw support feet 15. The casters 30 facilitate the overall movement of the ladder structure, and the screw support feet 15 facilitate reliable fixation and support of the entire ladder structure.

[0032] Preferably, the positioning inspection device includes a horizontal bar 6 fixed to the inner wall of the column 2, a diagonal brace 4 fixed between the horizontal bar 6 and the column 2, a positioning plate 5 fixed to the end of the horizontal bar 6, and a positioning shaft 8 fixed to the end of the positioning plate 5. The positioning shaft 8 is matched with the position of the wheel axle 13. There are four sets of positioning inspection devices. The installation position is determined by a laser tracker to ensure the accuracy of the installation position. The inspection fixture is in a vertical position when idle and in a horizontal position when in use. The two states can be quickly switched by inserting and removing quick-release pins, which facilitates the operator to quickly check the wheel axle position and landing gear installation height.

[0033] With the testing fixture in use, extend the landing gear shock absorber strut. Then, pass the positioning shaft through the positioning plate and insert the front end of the positioning shaft into the wheel axle. If the front end cannot be inserted into the wheel axle, it indicates that the position and height do not meet the requirements. At this time, the landing gear needs to be adjusted accordingly until the front end of the positioning shaft can be smoothly inserted into the wheel axle. Ensure the perpendicularity of the wheel axle crossbeam journal to the strut, and at the same time ensure the parallelism of the crossbeam axis to the axes of the two wheel axles.

[0034] See Figure 5 Preferably, the system also includes a supporting main landing gear hydraulic system. This main landing gear hydraulic system comprises two main landing gear retraction and extension control systems, left and right, connected to the hydraulic interfaces of the main landing gear via hydraulic conduits to form a hydraulic control loop. A hydraulic pump station provides system pressure to realize the retraction and extension of the main landing gear. Each left and right main landing gear retraction and extension control system includes a one-way valve 106 connected to the hydraulic interface of the main landing gear. The one-way valve 106 is connected to the main landing gear retraction and extension actuator 101 and the main landing gear retraction and extension mini-actuator 104 via a solenoid directional valve 105. An upper lock 102 is installed on the rodless chamber circuit of the main landing gear retraction and extension actuator 101, and a throttle valve 103 is installed on the rod-side chamber circuit of the main landing gear retraction and extension mini-actuator 104.

[0035] By controlling the solenoid directional valve, the flow direction of the hydraulic oil in the system is changed, and the hydraulic lock is opened, realizing the extension and retraction of the main landing gear actuator, thus fulfilling the main landing gear's retraction and extension functions. The throttle valve can change the cross-sectional size and control the flow rate in the system, ensuring the main landing gear actuator moves at a uniform speed and smoothly. The left and right main landing gear retraction and extension control circuits are identical. The following detailed explanation uses the left main landing gear retraction and extension control circuit as an example. The hydraulic principle diagram of the left main landing gear retraction and extension is shown in Figure 5. When the main landing gear retracts, the hydraulic conduit is connected to the corresponding interface on the main landing gear to form the retraction and extension control circuit. Start the main landing gear system motor pump unit. Under the action of the motor pump unit, the working medium passes through the primary and secondary oil filters. By adjusting the proportional pressure regulating valve, the system pressure reaches the corresponding value. Open the solenoid directional valve switch to conduct the "retracting landing gear" circuit. The working medium enters the main landing gear actuator cylinder through the solenoid directional valve to realize the main landing gear retraction action. When the main landing gear is lowered, the solenoid directional valve needs to be operated to switch the direction, so that the "lowering landing gear" circuit is conducted to realize the main landing gear lowering action.

[0036] When the main landing gear is retracted, the reversing valve is in the retracted position. Pressurized oil flows through the solenoid reversing valve 105 to the rodless chamber of the main landing gear retraction actuator 104 and the rod chamber of the main landing gear retraction actuator 101. The piston rod of the actuator 104 extends, causing the foldable support rod on the main landing gear to unfold and unlock. The piston rod of the main landing gear retraction actuator 101 retracts, pulling the landing gear back up and engaging the upper lock. The oil in the rod chamber of the actuator 104 and the rodless chamber of the retraction actuator 101 returns to the hydraulic pump station tank via the solenoid valve 105 and the check valve 106.

[0037] When the main landing gear is lowered, the reversing valve is in the lowered position. Pressurized oil flows through solenoid valve 105 into the upper lock one-way hydraulic actuator, the rodless chamber of the main landing gear retraction actuator 101, and the rod-side chamber of the main landing gear retraction actuator 104. After the upper lock is opened and the locking hook disengages, the piston rod of the main landing gear retraction actuator 101 extends, and the piston rod of the main landing gear retraction actuator 104 slowly retracts. The landing gear is lowered under gravity and the hydraulic thrust of the actuator until the collapsible support rod on the main landing gear is fully extended and locked, completing the landing gear lowering. The oil in the rodless chamber of the retraction actuator 104 and the oil in the rod-side chamber of the retraction actuator 101 return to the hydraulic pump station tank via solenoid valve 105 and one-way valve 106. The piston rod of the upper lock actuator is automatically reset by a spring after depressurization.

[0038] The working process and principle of this utility model: Positioning inspection device: The positioning and inspection device consists of a crossbar, a positioning plate, and a positioning shaft. Four sets of inspection fixtures are installed on both sides of the frame. The installation position is determined by a laser tracker to ensure the accuracy of the installation position. The inspection fixture is in a vertical position when idle and in a horizontal position when in use. The two states can be quickly switched by inserting and removing quick-release pins, which makes it easy for operators to quickly check the position of the wheel axle and the installation height of the landing gear.

[0039] With the testing fixture in use, extend the landing gear shock absorber strut. Then, pass the positioning shaft through the positioning plate and insert the front end of the positioning shaft into the wheel axle. If the front end cannot be inserted into the wheel axle, it indicates that the position and height do not meet the requirements. At this time, the landing gear needs to be adjusted accordingly until the front end of the positioning shaft can be smoothly inserted into the wheel axle. Ensure the perpendicularity of the wheel axle crossbeam journal to the strut, and at the same time ensure the parallelism of the crossbeam axis to the axes of the two wheel axles.

[0040] See Figure 6 To complete the main landing gear deflection measurement, a main landing gear deflection measuring instrument was configured, which consists of a main body, a movable handle, a threaded connector, a connector, a bent shank cylindrical pin, and a measuring connector. (See below.) Figure 6 As shown, the installation positions of each component of the main deflection measuring device are shown.

[0041] The main body of the landing gear deflection measuring device consists of a steel pipe bent to match the shape of the landing gear and a precision-machined square block welded onto it. Other threaded joints and connectors are installed on their corresponding square blocks.

[0042] In use, the two connectors are connected to the corresponding connectors on the landing gear struts, and the middle measuring connector is connected to the measuring point connector on the landing gear struts. The curved shank cylindrical pin is inserted, and the maximum distance A between the measuring connector and the curved shank cylindrical pin is measured according to the deflection value measurement method label. The required deflection value f is calculated using the formula f=|A-50| (reference deflection value: f=4.5+0.8-0.5, reference: "Y-8 Aircraft Technical Conditions").

Claims

1. An integrated ground testing and commissioning platform for aircraft main landing gear, characterized in that, The system includes a bottom frame (1), a top frame (11) supported by a column (2) at the top of the bottom frame (1), a top platform (10) fixed at the top of the top frame (11), a main attachment point (27) for hinged landing gear (14) fixed at the bottom end face of the top frame (11), a front attachment point (23) fixed at the inner side end face of the top frame (11), a retraction actuator (21) hinged to the side wall of the landing gear (14), the top of the retraction actuator (21) hinged to the bottom end of the top frame (11) through the retraction actuator attachment point (24), and a horizontal axis (29), a deflection measuring rod (22) and a strut (28) hinged between the front attachment point (23) and the landing gear (14); a positioning and inspection device for measuring the height of the wheel axle (13) of the wheel (7) is installed on the lower inner side wall of the column (2).

2. The integrated test bench for ground-based commissioning of aircraft main landing gear according to claim 1, characterized in that: A diagonal reinforcing bar (3) is fixed between the column (2) and the bottom frame (1).

3. The ground-based integrated testing platform for aircraft main landing gear according to claim 1, characterized in that: The upper part of the column (2) is fixed with a reinforcing crossbeam (9). The top of the top platform (10) is fixed with platform railings (12) around its top.

4. The integrated ground testing platform for aircraft main landing gear according to claim 1, characterized in that: It also includes a ladder structure, which includes a ladder base (16), a ladder frame (18) fixed on the top of the ladder base (16), a ladder board (17) on the ladder frame (18), side rails (19) symmetrically fixed on both sides of the ladder frame (18), and a ladder top plate (20) fixed on the top of the ladder frame (18), which is flush with the top platform (10).

5. The integrated test bench for ground-based commissioning of aircraft main landing gear according to claim 4, characterized in that: The top plate (20) of the ladder is fixed with a top railing (31) around its perimeter, and the bottom corners of the ladder base (16) are fixed with casters (30). The bottom of the ladder base (16) is equipped with screw support feet (15).

6. The integrated ground testing platform for aircraft main landing gear according to claim 1, characterized in that: The positioning inspection device includes a horizontal bar (6) fixed on the inner wall of the column (2), a diagonal brace (4) fixed between the horizontal bar (6) and the column (2), a positioning plate (5) fixed at the end of the horizontal bar (6), a positioning shaft (8) fixed at the end of the positioning plate (5), and the positioning shaft (8) is matched with the position of the wheel axle (13).

7. The integrated ground testing platform for aircraft main landing gear according to claim 1, characterized in that: It also includes a supporting main landing gear hydraulic system, which includes two main landing gear retraction and extension control systems, one for the left and one for the right. These systems are connected to the hydraulic interfaces of the main landing gear through hydraulic conduits to form a hydraulic control loop. The system pressure is provided by a hydraulic pump station to realize the retraction and extension of the main landing gear.

8. The integrated ground testing platform for aircraft main landing gear according to claim 7, characterized in that: The single left and right main landing gear retraction control system includes a check valve (106) connected to the hydraulic interface of the main landing gear. The check valve (106) is connected to the main landing gear retraction actuator (101) and the main landing gear retraction small actuator (104) via a solenoid directional valve (105). An upper lock (102) is installed on the rodless chamber circuit of the main landing gear retraction actuator (101), and a throttle valve (103) is installed on the rod chamber circuit of the main landing gear small actuator (104).

9. The integrated test bench for ground-based testing of aircraft main landing gear according to claim 7, characterized in that: The bottom frame (1) is provided with an upper lock hook point (25) and a support rod hook point (26) at the bottom end and on the side of the retraction and extension actuator hook point (24).

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