Undercarriage folding and unfolding system capable of controlling folding and unfolding and locking through single actuation

Abstract

The invention belongs to the technical field of aircraft landing gears, and particularly discloses an undercarriage folding and unfolding system for single-action control folding and unfolding and locking, which comprises a first supporting rod, a second supporting rod, a third supporting rod, a folding and unfolding actuating cylinder and a multi-connecting rod mechanism, one end, connected with the undercarriage cabin, of the first supporting rod is hinged to a connector, and the other end is provided with an airplane wheel; the other end of the second supporting rod is hinged to a third supporting rod, and the end, away from the second supporting rod, of the third supporting rod is hinged to the middle of the first supporting rod; an upper lock mechanism is arranged on a rod body of the second supporting rod, and a lower lock mechanism is arranged at one end close to the third supporting rod; the retracting and releasing actuating cylinder is connected between the connector and the steering knuckle and is in transmission connection with the lower lock mechanism through the multi-connecting-rod mechanism. The multi-connecting-rod mechanism is compact in structure and easy to operate, the multi-connecting-rod mechanism is driven through the single actuator cylinder, the folding, unfolding and locking functions of the undercarriage can be synchronously completed, the operation process is simplified, the structural stability is improved, and the service life of the undercarriage can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft landing gear systems, and particularly to a landing gear retraction and extension system that uses single-actuator control for retraction, extension, and locking. Background Art

[0002] In the aviation field, the landing gear, as the core load-bearing system for an aircraft during takeoff, landing, and ground taxiing, is closely related to flight safety. The performance of the landing gear directly affects the takeoff and landing safety of the aircraft and the stability of ground operations. Therefore, the design of the landing gear has always been one of the important research directions in aviation technology.

[0003] Currently, the landing gears of many aircraft use multiple actuators to separately perform retraction, extension, and locking actions. Although this design can achieve the basic functions of the landing gear, it also has many problems: Firstly, the arrangement of multiple actuators requires a large amount of internal aircraft space, which poses a great challenge to the already compact internal aircraft layout design, severely squeezing the installation space of other key equipment, and thus affecting the optimization of the overall aircraft performance. Secondly, the weight of multiple actuators is relatively large, which undoubtedly increases the overall weight of the aircraft. The increase in aircraft weight not only leads to an increase in fuel consumption and a decrease in flight efficiency but may also have an adverse impact on the aircraft's maneuverability, range, and other performances. In addition, in actual operation, the coordinated control of multiple actuators is quite difficult, and it is extremely easy to have uncoordinated actions during retraction, extension, and locking, resulting in abnormal operation of the landing gear and even endangering the normal takeoff and landing of the aircraft in severe cases.

[0004] In summary, the existing landing gear systems have many deficiencies in terms of structural complexity, weight, space occupation, and reliability. Therefore, it is particularly important to develop a landing gear retraction and locking mechanism with a simple structure, high reliability, and the ability to effectively withstand landing impacts. Summary of the Invention

[0005] The purpose of the present invention is to provide a landing gear retraction and extension system that uses single-actuator control for retraction, extension, and locking. Through innovative structural design, the efficient retraction, extension, and locking functions of the landing gear are achieved, while solving the problems of large space occupation, weight increase, high coordinated control difficulty, and low reliability existing in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following scheme: a landing gear retraction and locking system with single-actuation control, comprising a first strut and a second strut which are rotatably connected to different positions of a landing gear compartment body; one end of the first strut connected to the landing gear compartment body is hinged to a connecting head, and the other end is equipped with a wheel; one end of the second strut connected to the landing gear compartment body is hinged to a steering knuckle, and the other end is hinged to a third strut, and the end of the third strut away from the second strut is hinged to the middle part of the first strut; an upper locking mechanism is provided on the rod body of the second strut, and a lower locking mechanism is provided on the end of the second strut close to the third strut; a retraction and extension cylinder is connected between the connecting head and the steering knuckle, and the steering knuckle is transmission-connected to the lower locking mechanism through a multi-link mechanism; the action of the retraction and extension cylinder forms a complete power transmission system through the steering knuckle and the multi-link mechanism, which is used to drive the unlocking or locking of the upper locking mechanism and the lower locking mechanism.

[0007] When the retracting and extending actuator is extended, the steering knuckle is pushed to move, and the steering knuckle drives the multi-link mechanism to pull the lower lock mechanism to unlock, and drives the first strut, the second strut, and the third strut to retract, and the upper lock mechanism is locked to maintain the retracted state of the landing gear.

[0008] When the retraction and extension actuator shrinks, the steering knuckle is pulled, and the steering knuckle drives the multi-link mechanism to push the upper lock mechanism to unlock. The landing gear is deployed under the action of gravity and aerodynamic force, and the multi-link mechanism pushes the lower lock mechanism to lock, maintaining the deployed state of the landing gear.

[0009] Optionally, the multi-link mechanism includes a first link, a second link, a sleeve and a third link, one end of the first link is connected to the connecting head, and the other end is connected to the second link, one end of the second link away from the first link slides in the sleeve, one end of the third link is rotatably connected to the sleeve, and the other end is rotatably connected to the lower lock hook for transmitting power.

[0010] Optionally, a limiting mechanism is provided in the sleeve.

[0011] Optionally, the upper locking mechanism includes an upper locking hook and an upper locking tongue fixed on the landing gear compartment body, and the upper locking hook is connected to the retractable actuator cylinder through a first connecting rod and a second connecting rod.

[0012] Optionally, the lower locking mechanism includes a lower locking hook and a lower locking tongue fixed to the side of the third support rod, the lower locking hook is connected to the retractable actuator cylinder through a third connecting rod and a sleeve, and the retractable actuator cylinder controls the separation or locking of the lower locking hook and the lower locking tongue by driving the multi-link mechanism.

[0013] Optionally, the lower locking hook is connected to an extension of the second support rod.

[0014] Optionally, the first support rod is in a Y-shaped structure.

[0015] Optionally, a hoop mechanism is installed in the middle of the first strut. One end of the third strut is hinged to the second strut, and the other end is hinged to the hoop mechanism to form a multi-link transmission chain.

[0016] Optionally, the hoop mechanism includes a hoop body and fastening bolts.

[0017] Optionally, the retracting and extending actuator is an electric actuator.

[0018] Compared with the prior art, the present invention discloses at least the following beneficial effects:

[0019] The landing gear retracting and extending system of the present invention has a compact structure and simple operation. By driving a multi-link mechanism with a single actuator, it can synchronously complete the retracting, extending and locking functions of the landing gear, simplifying the operation process of the landing gear. In the deployed state, the transmission chain forms a stable triangular structure, improving the structural stability. This structural design enables the transmission link of the locking mechanism to only bear the actuating force during the retracting and extending stages, while the landing impact load is directly transmitted by the main load-bearing member, thereby enhancing the reliability of the system, reducing the risk of damage to the landing gear during use, and extending the service life of the landing gear. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is the front view of the landing gear retracting and extending system with single-actuator control for retracting, extending and locking of the present invention;

[0022] Figure 2 is Figure 1 the partial enlarged view at A in

[0023] Figure 3 It is the top view of the landing gear retracting and extending system with single-actuator control for retracting, extending and locking of the present invention;

[0024] Figure 4 It is the right view of the landing gear retracting and extending system with single-actuator control for retracting, extending and locking of the present invention;

[0025] Figure 5 It is the axonometric view of the landing gear retracting and extending system with single-actuator control for retracting, extending and locking of the present invention;

[0026] Figure 6 is Figure 5 the partial enlarged view at B in

[0027] Figure 7 This is a schematic diagram of the landing gear retraction system of the present invention in the retracted state;

[0028] Figure 8 This is a schematic diagram of the upper lock in the locked state in the landing gear retraction system of the present invention;

[0029] Figure 9 This is a schematic diagram of the upper lock in the unlocked state in the landing gear retraction system of the present invention;

[0030] Figure 10 This is a schematic diagram of the landing gear retraction system of the present invention in the deployed state;

[0031] Figure 11 This is a schematic diagram of the lower lock in the locked state in the landing gear retraction system of the present invention;

[0032] Figure 12 This is a schematic diagram of the lower lock in the unlocked state in the landing gear retraction system of the present invention.

[0033] In the figure: 1, connector; 2, first strut; 3, hoop mechanism; 4, wheel; 5, landing gear cabin; 6, retraction actuator; 7, first connecting rod; 8, steering knuckle; 9, second strut; 10, second connecting rod; 11, upper lock hook; 12, sleeve; 13, third connecting rod; 14, lower lock hook; 15, third strut; 16, lower lock tongue; 17, upper lock tongue. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0036] Refer to Figures 1 to 12As shown in the figure, an undercarriage retraction and extension system with single-actuation control for retraction, extension, and locking is provided in an embodiment of the present invention. It is connected to the undercarriage compartment 5 and mainly includes a first strut 2, a second strut 9, and a third strut 15. Among them, the first strut 2 and the second strut 9 are respectively rotatably connected to different positions of the undercarriage compartment 5. The second strut 9 is movably connected to the first strut 2 through a connector 1 and a retraction and extension actuator 6. One end of the third strut 15 is hinged to the end of the second strut 9 away from the undercarriage compartment 5, and the other end is hinged to the middle of the first strut 2. The above key components work together through specific connection relationships to achieve the retraction, extension, and locking functions of the undercarriage.

[0037] Specifically, as Figures 1 to 6 shown, the connector 1 is rotatably connected to the undercarriage compartment 5 and rotatably connected to the piston rod of the retraction and extension actuator 6 at the front end, playing a basic role in connecting the undercarriage compartment 5 and the retraction and extension actuator 6. The first strut 2 is rigidly connected to the connector 1, bears the wheel 4 assembly, and has a Y-shaped structure, which is a key component for the undercarriage to support the weight of the aircraft. The second strut 9 is rotatably connected to the undercarriage compartment 5 and forms a transmission chain with the third strut 15 through series hinges. An extension part is provided on the second strut 9 for connecting the lower locking hook 14 when the undercarriage is deployed. The end of the third strut 15 is rotatably connected to the first strut 2 through a hoop mechanism 3. The hoop mechanism 3 includes a hoop body and fastening bolts to ensure the stable connection between the third strut 15 and the first strut 2. The retraction and extension actuator 6 is an electric actuator that provides the power for the undercarriage retraction and extension, and drives the upper locking hook 11 and the lower locking hook 14 to separate or lock through components such as a knuckle 8, a first link 7, a second link 10, a sleeve 12, and a third link 13. The lower locking hook 14 is connected to the extension part of the second strut 9 when the undercarriage is deployed and forms a cross-shaped structure with the extension part when locked, for locking the undercarriage. The upper locking hook 11 acts on the protruding part on the inner wall of the undercarriage compartment when the undercarriage is retracted and forms a cross-shaped structure with the protruding part when locked, for locking the undercarriage. One end of the first link 7 is rotatably connected to the second link 10, and the other end is rotatably connected to the knuckle 8, serving as part of the power transmission system. The sleeve 12 is slidably connected to the second link 10 and has a limiting mechanism inside to limit the sliding distance of the second link 10. One end of the third link 13 is rotatably connected to the sleeve 12, and the other end is rotatably connected to the lower locking hook 14 for transmitting power. One end of the knuckle 8 is rotatably connected to the retraction and extension actuator 6, the other end is rotatably connected to the first link 7, and the middle part is rotatably connected to the second strut 9. A limiting mechanism is provided between the knuckle 8 and the second strut 9 for achieving the steering and limiting functions.

[0038] In the above embodiments, the first link 7, the second link 10, the sleeve 12, and the third link 13 form a multi-link mechanism. When the retraction and extension actuator 6 extends, it pushes the steering knuckle 8 to act. The steering knuckle 8 drives the multi-link mechanism to pull the lower locking hook 14 to unlock, and drives the first strut 2, the second strut 9, and the third strut 15 to retract. The upper locking hook 11 locks to maintain the landing gear in the retracted state. When the retraction and extension actuator 6 contracts, it pulls the steering knuckle 8 to act. The steering knuckle 8 drives the multi-link mechanism to push the upper locking hook 11 to unlock. The landing gear unfolds under the action of gravity and aerodynamic force. The multi-link mechanism pushes the lower locking hook 14 to lock to maintain the landing gear in the unfolded state.

[0039] In a specific embodiment, the connector 1 is rotatably connected to the landing gear housing 5 and is rotatably connected to the piston rod of the retraction and extension actuator 6 at the front end. The connector 1 serves to connect the landing gear housing 5 and the retraction and extension actuator 6, providing a basic connection structure for the retraction and extension of the landing gear. The connector 1 is a key connecting component between the landing gear housing 5 and the retraction and extension actuator 6, which transmits the power of the retraction and extension actuator 6 to other components of the landing gear.

[0040] In a specific embodiment, the first strut 2 is connected to the landing gear housing 5 through the connector 1, and is also connected to the second strut 9 and the third strut 15 through the hoop mechanism 3 to form the main support structure of the landing gear. The first strut 2 is rigidly connected to the connector 1, carries the wheel 4, and has a Y-shaped structure. The first strut 2 is a key component for the landing gear to support the weight of the aircraft and achieve the takeoff and landing functions.

[0041] In a specific embodiment, one end of the second strut 9 is connected to the landing gear housing 5, the other end is serially hinged to the third strut 15, and the middle is connected to the power transmission system of the retraction and extension actuator 6 through the steering knuckle 8. It is rotatably connected to the landing gear housing 5, forms a transmission chain with the third strut 15 through serial hinge, and is provided with an extension part. It transmits power during the retraction, extension, and locking of the landing gear, realizes the state switching of the landing gear through the second strut 9, forms a "two-force bar" structure with the third strut 15, and cooperates with the lower locking hook 14 to ensure the stable support of the landing gear.

[0042] In a specific embodiment, one end of the third strut 15 is serially hinged to the second strut 9, and the other end is connected to the first strut 2 through the hoop mechanism 3 to form the support and transmission structure of the landing gear. The end of the third strut 15 is rotatably connected to the first strut 2 through the hoop mechanism 3. At the same time, it forms a transmission chain with the second strut 9 through serial hinge, transmits power during the retraction, extension, and locking of the landing gear, and realizes the state switching of the landing gear.

[0043] In a specific embodiment, the front end of the piston rod of the retracting and extending actuator 6 is rotatably connected to the connector 1, and is connected to components such as the first link 7, the second link 10, the sleeve 12, and the third link 13 through the knuckle 8 to form a complete power transmission system. The retracting and extending actuator 6 can be selected as an electric actuator, which is used to provide the power for the landing gear retraction and extension, and drives the upper locking hook 11 and the lower locking hook 14 to separate or lock through components such as the knuckle 8, the link, and the sleeve 12, so as to realize the retraction, extension, and locking functions of the landing gear.

[0044] In a specific embodiment, the lower locking hook 14 is connected to the sleeve 12 through the third link 13, and its connection and separation with the lower locking tongue 16 are controlled by the retracting and extending actuator 6 through the power transmission system. Among them, the lower locking tongue 16 is fixedly connected to the side of the third strut 15. When the landing gear is deployed, the lower locking hook 14 and the lower locking tongue 16 are locked and matched to lock the landing gear and ensure its stability during landing.

[0045] In a specific embodiment, the upper locking hook 11 is connected to the retracting and extending actuator 6 through components such as the first link 7, the second link 10, the sleeve 12, and the third link 13, and its connection and separation with the upper locking tongue 17 are controlled by the retracting and extending actuator 6. Among them, the upper locking tongue 17 is specifically a convex portion provided on the inner wall of the landing gear compartment. When the landing gear is retracted, the upper locking hook 11 and the upper locking tongue 17 are locked and matched to lock the landing gear and ensure its stability during flight.

[0046] In a specific embodiment, the first link 7 connects the knuckle 8 and the second link 10, and is a key connecting component between the retracting and extending actuator 6 and the locking hook. One end of the first link 7 is rotatably connected to one end of the second link 10, and the other end is rotatably connected to the knuckle 8. As a part of the power transmission system, the first link 7 transmits the power of the retracting and extending actuator 6 to the upper locking hook 11 and the lower locking hook 14.

[0047] In a specific embodiment, the second link 10 is a rigid rod body, and rotating connection points are respectively designed at both ends thereof. One end of it is rotatably connected to one end of the first link 7, and the other end is slidably connected to the sleeve 12. This structure enables the second link 10 to slide and rotate within a certain range to meet the motion requirements during the retraction and extension of the landing gear. The second link 10 is a key transmission component of the landing gear retraction, extension, and locking system. It transmits the power of the retracting and extending actuator 6 to the sleeve 12 and the third link 13 through the first link 7, and then drives the separation and locking of the upper locking hook 11 and the lower locking hook 14 to realize the retraction, extension, and locking functions of the landing gear.

[0048] In a specific embodiment, the sleeve 12 is connected to the first link 7 through the second link 10, and is connected to the lower lock hook 14 through the third link 13, playing the role of limiting and connecting, limiting the sliding distance of the second link 10, and ensuring the accuracy and reliability of power transmission. Furthermore, there is a limit mechanism in the sleeve 12 to limit the sliding distance of the second link 10, thereby ensuring the movement accuracy and stability of the landing gear during the retraction and extension process, and preventing excessive movement between components from causing system failure.

[0049] In a specific embodiment, the limiting mechanism in the sleeve 12 is an annular boss provided on the inner wall of the sleeve 12, and the annular boss extends axially along the sleeve 12 to form a guide groove; the end of the second connecting rod 10 is provided with a radial protrusion matching the guide groove, and the moving stroke of the radial protrusion is limited by the axial length of the guide groove; when the second connecting rod 10 is driven to make axial displacement, its radial protrusion moves along the guide groove to the end of the annular boss and is blocked. At this time, the third connecting rod 13 and the lower lock hook 14 form a precise linkage cooperation to realize the stroke control of the opening and closing action of the lower lock.

[0050] In a specific embodiment, the third connecting rod 13 connects the sleeve 12 and the lower locking hook 14, and is a key connecting component between the retracting and extending cylinder 6 and the lower locking hook 14. One end of the third connecting rod 13 is rotatably connected to the other end of the sleeve 12, and the other end is rotatably connected to the middle of the lower locking hook 14. As part of the power transmission system, the third connecting rod 13 transmits the power of the retracting and extending cylinder 6 to the lower locking hook 14.

[0051] In a specific embodiment, one end of the steering knuckle 8 is rotatably connected to the retractable actuator 6, the other end is rotatably connected to the first connecting rod 7, the middle part is rotatably connected to the second support rod 9, and a limiting mechanism is provided between the steering knuckle 8 and the second support rod 9. As a key component of the power transmission system, the steering knuckle 8 connects the retractable actuator 6, the first connecting rod 7 and the second support rod 9, transmits the power of the retractable actuator 6 to the first connecting rod 7 and the second support rod 9, and realizes the steering and limiting functions through the limiting mechanism.

[0052] In a specific embodiment, the clamp mechanism 3 clamps the body and the fastening bolts, the clamp body clamps the first strut 2, and the clamping force is adjusted by the fastening bolts. The clamp mechanism 3 connects the third strut 15 and the first strut 2 to play a role of fixing and connecting, ensuring that the third strut 15 is firmly connected to the first strut 2 and no relative displacement occurs during the operation of the landing gear.

[0053] The working process of the embodiment of the present invention is as follows:

[0054] Landing gear retraction process: When the aircraft takes off, the retraction actuator 6 operates, and the piston rod extends to push the steering knuckle 8. The steering knuckle 8 successively pulls the lower latch hook 14 away from the extension through the first link 7, the second link 10, the sleeve 12, and the third link 13. Subsequently, the steering knuckle 8 is limited and locked. Driven by the retraction actuator 6, the first strut 2, the second strut 9, and the third strut 15 start to rotate and slowly retract until the landing gear is retracted and locked by the upper latch hook 11. At this time, the retraction actuator 6 stops working and maintains the current pressure to maintain the stable state of the retracted landing gear.

[0055] Landing gear deployment process: Before the aircraft lands, the landing gear needs to be deployed. The retraction actuator 6 operates again, and the piston rod contracts. First, it drives the first link 7 and the second link 10 through the steering knuckle 8 to push the upper latch hook 11 to unlock past the dead point. Then, under the action of gravity and aerodynamic force, the landing gear slowly deploys, and the retraction actuator 6 provides auxiliary power. When the landing gear is deployed until the second strut 9 is parallel to the third strut 15, the retraction actuator 6 contracts to drive the steering knuckle 8 to rotate. The steering knuckle 8 pushes the lower latch hook 14 to lock through the first link 7, the second link 10, the sleeve 12, and the third link 13, realizing the lower position locking of the landing gear and providing stable support for the aircraft to land.

[0056] During the entire landing gear retraction, locking, and deployment process, the triangular structure formed by the retraction actuator 6, the second strut 9, the third strut 15, and the first strut 2 exhibits strong stability in the deployed state, which can effectively disperse the impact force during aircraft landing and taxiing, ensuring that the landing gear can reliably support the weight of the aircraft. This system drives a multi-link mechanism through a single actuator, cleverly realizing the synchronous control of landing gear retraction, locking, and deployment, simplifying the system structure, and reducing the operation complexity.

[0057] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0058] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A landing gear retraction and locking system with single-actuation control, characterized in that: The invention comprises a first strut (2) and a second strut (9) which are rotatably connected to different positions of a landing gear compartment (5); one end of the first strut (2) connected to the landing gear compartment (5) is hinged to a connecting head (1), and the other end is provided with a wheel (4); one end of the second strut (9) connected to the landing gear compartment (5) is hinged to a steering knuckle (8), and the other end is hinged to a third strut (15); one end of the third strut (15) away from the second strut (9) is hinged to the middle part of the first strut (2); the second strut ( An upper locking mechanism is provided on the rod body of the second support rod (9), and a lower locking mechanism is provided on one end of the second support rod (9) close to the third support rod (15); a retractable actuator cylinder (6) is connected between the connecting head (1) and the steering knuckle (8), and the steering knuckle (8) is transmission-connected to the lower locking mechanism through a multi-link mechanism; the movement of the retractable actuator cylinder (6) forms a complete power transmission system through the steering knuckle (8) and the multi-link mechanism, which is used to drive the upper locking mechanism and the lower locking mechanism to unlock or lock.

2. The single-actuation control retraction and locking landing gear retraction system according to claim 1, characterized in that: The multi-link mechanism comprises a first link (7), a second link (10), a sleeve (12) and a third link (13); one end of the first link (7) is connected to the connecting head (1), and the other end is connected to the second link (10); the end of the second link (10) away from the first link (7) slides in the sleeve (12); one end of the third link (13) is rotatably connected to the sleeve (12), and the other end is rotatably connected to the lower locking hook (14) for transmitting power.

3. The single-actuation control retraction and locking landing gear retraction system according to claim 2, characterized in that: A limiting mechanism is provided inside the sleeve (12), and the limiting mechanism is an annular boss provided on the inner wall of the sleeve (12), and the annular boss extends axially along the sleeve (12) to form a guide groove; a radial protrusion matching the guide groove is provided at the end of the second connecting rod (10), and the moving stroke of the radial protrusion is limited by the axial length of the guide groove.

4. The single-actuation control retraction and locking landing gear retraction system according to claim 2, characterized in that: The upper locking mechanism comprises an upper locking hook (11) and an upper locking tongue (17) fixed on the landing gear cabin (5); the upper locking hook (11) is connected to the retractable actuator cylinder (6) via a first connecting rod (7) and a second connecting rod (10).

5. The single-actuation control retraction and locking landing gear retraction system according to claim 2, characterized in that: The lower lock mechanism comprises a lower lock hook (14) and a lower lock tongue (16) fixed on the side of a third support rod (15); the lower lock hook (14) is connected to the retractable actuator cylinder (6) via a third connecting rod (13) and a sleeve (12); the retractable actuator cylinder (6) controls the separation or locking of the lower lock hook (14) and the lower lock tongue (16) by driving a multi-link mechanism.

6. The single-actuation control retraction and locking landing gear retraction system according to claim 5, characterized in that: The lower locking hook (14) is connected to an extension of the second support rod (9).

7. The single-actuation control retraction and locking landing gear retraction system according to claim 1, characterized in that: The first support rod (2) is in a Y-shaped structure.

8. The single-actuation control retraction and locking landing gear retraction system according to claim 1, characterized in that: A clamp mechanism (3) is installed in the middle of the first support rod (2); one end of the third support rod (15) is hinged to the second support rod (9), and the other end is hinged to the clamp mechanism (3), forming a multi-link transmission chain.

9. The single-actuation control retraction and locking landing gear retraction system according to claim 8, characterized in that: The clamp mechanism (3) comprises a clamp body and a fastening bolt.

10. The single-actuation control retraction and locking landing gear retraction system according to claim 1, characterized in that: The retractable actuator (6) is an electric actuator.

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