An aircraft landing gear bay door separation mechanism

Abstract

The present application belongs to the field of aircraft landing system design, and relates to an aircraft cabin door separation mechanism. The aircraft cabin door separation mechanism adopts a multi-linkage rotary throw + push and impact unlocking separation principle, and comprises an aircraft body structure, a landing gear cabin door, a short linkage, a long linkage, an actuating cylinder, a free hinge, a rotary unlocking hinge and a landing gear cabin door lock.

Description

TECHNICAL FIELD

[0001] The present application relates to an aircraft landing gear door separation mechanism applied to the landing gear door of an aircraft with a retractable landing gear, and belongs to the field of aircraft landing system design. BACKGROUND

[0002] The landing gear door is an essential component of an aircraft with a retractable landing gear, and the normal opening of the landing gear door before the landing of the aircraft is a prerequisite for the normal extension of the landing gear. Due to the spacious internal space and relatively mild flight conditions of traditional aircraft, the landing gear door opening and closing mode can be designed as simple fixed shaft rotation, or can be designed as a linkage form together with the landing gear. However, for small-size low-lift-drag-ratio aircraft, the landing gear door design faces four major challenges: 1) The landing sink speed of low-lift-drag-ratio aircraft is too high. In order to match the landing impact and braking capacity, not only the tire size needs to be increased, but also the landing gear needs to be designed to be thick and strong, which forces the landing gear door size to be further increased, thereby causing the landing gear door extension / retraction mechanism layout to be difficult; 2) The internal space of small-size aircraft is insufficient. When large-size landing gears are laid out, the left and right spacing is too short, causing the motion range of the inward-opening landing gear door opening towards the central axial plane of the aircraft to interfere with each other; 3) The landing sink speed of low-lift-drag-ratio aircraft is too high. The landing impact will greatly compress the landing gear shock absorber, causing the opened landing gear door to collide with the ground and causing damage to the landing gear door.

[0003] In order to avoid the above problems, the traditional retractable landing gear door structure design needs to be abandoned to avoid potential interference or influence of the landing gear door on the landing gear. The separable landing gear door can be separated from the aircraft before the landing gear is extended, which fundamentally avoids various risks brought by the landing gear door to the aircraft landing. However, there are two major technical challenges in the design of the separable landing gear door of low-lift-drag-ratio aircraft: 1) The simple gooseneck rocker arm type landing gear door extension / retraction mechanism occupies a large space and cannot be laid out in the narrow internal space of the aircraft. 2) After the landing gear door is separated, it continues to move under the influence of aerodynamic load, which has the risk of collision with the aircraft. Especially for low-lift-drag-ratio aircraft, the landing speed is high, the flight pressure is large, and the collision risk is higher, which requires special design of the door separation mechanism to solve the above challenges. SUMMARY

[0004] (I) Technical problems to be solved

[0005] In view of the deficiencies of the prior art, the present application provides a landing gear door separation mechanism suitable for small-size low-lift-drag-ratio aircraft, which fundamentally solves the problems of potential collision of the landing gear door with the ground during the landing phase of the aircraft and collision of the landing gear door with the aircraft, and significantly reduces the landing risk of small-size low-lift-drag-ratio aircraft.

[0006] The technical problems solved by the present application are: 1. overcoming the risk of collision between the existing deployable aircraft landing gear door and the ground during landing on a small-size low-lift-drag-ratio aircraft; 2. overcoming the deficiency of the traditional door deployment mechanism that occupies a large space and cannot be arranged in a narrow aircraft interior; 3. avoiding the risk of collision between the landing gear door and the aircraft under the action of aerodynamic load after the landing gear door separates from the aircraft.

[0007] (II) Technical solutions

[0008] The present application discloses a kind of aircraft landing gear door separation mechanism, the separation mechanism adopts multi-linkage rotary throw + push and rush unlocking separation principle, including aircraft body structure, landing gear door, short connecting rod, long connecting rod, actuator, free hinge, rotary unlocking hinge and landing gear door lock.

[0009] Two groups of separation mechanisms are symmetrically arranged on the two sides of landing gear door. Each group of separation mechanisms is composed of a short connecting rod, a long connecting rod and an actuator, one end of the short connecting rod and the long connecting rod is connected with the aircraft body structure, and the other end is connected with the landing gear door. The long connecting rod is also connected with the actuator. After the landing gear door is opened by a certain angle, the aerodynamic force acting on the landing gear door during flight is used to accelerate the separation of the landing gear door and the aircraft.

[0010] The rotary unlocking hinge is composed of a rotary throw sliding pin and a rotary throw sliding sleeve on one end of the short connecting rod, a rotary throw hook and a rotary throw sliding sleeve top pin at the corresponding position on the landing gear door. The hinge can be locked by cooperation before the landing gear door is rotated and opened, and the hinge constraint is released after the landing gear door and the connecting rod are rotated to a certain angle, realizing the separation of the landing gear door.

[0011] The free hinge is composed of a free hinge sleeve at one end of the long connecting rod and a free hinge top pin at the corresponding position on the landing gear door. The hinge mainly transmits the separation power from the actuator to the landing gear door through the long connecting rod, realizing the opening of the landing gear door.

[0012] The connecting rod is used to guide the movement direction of the landing gear door, so that the landing gear door can also make translational motion while being rotated and opened, ensuring that the door does not interfere with the aircraft body structure.

[0013] The actuator is used to provide the power for the movement of the landing gear door, one end of the actuator is connected with the aircraft body structure, and the other end is connected to the reversing rocker arm of the long connecting rod, converting the thrust of the actuator into the rotary torque of the long connecting rod.

[0014] The landing gear bay door lock is used to connect the landing gear bay door with the aircraft body structure before the landing gear bay door is opened, to maintain the integrity of the aircraft body structure and aerodynamic shape, and to prevent the landing gear bay door from freely moving. The connection between the landing gear bay door and the aircraft body structure is released when the landing gear bay door needs to be opened, so that the landing gear bay door can rotate around the hinge.

[0015] By designing the angles and positions of the rotary throw hooks, the rotary throw sliding sleeves, the rotary throw sliding pins and the rotary throw sliding sleeve top pins, the connecting rods and the landing gear bay door in the closed position can be kept in the interlocked state. Thus, only the landing gear bay door lock needs to be arranged on the right end surface of the landing gear bay door to achieve the in-place locking of the landing gear bay door. Figure 1 Since the landing gear bay door can only rotate around the rotary throw sliding sleeve top pin, when the landing gear bay door is in the closed state, the long connecting rod and the short connecting rod are made as parallel to the landing gear bay door as possible, so that the landing gear bay door can move in the direction of the outer normal of the landing gear bay door plane when it is just opened, and the interference between the heavy landing gear bay door and the aircraft body structure is avoided.

[0016] The movement process of the mechanism is as follows: when the landing gear bay door is separated, the separation power is first provided by the actuating cylinder. With the elongation of the actuating cylinder, the actuating cylinder pushes the long connecting rod to rotate around the fixed axis through the steering rocker on the long connecting rod, and then transmits the power to the landing gear bay door through the free hinge, and pushes the landing gear bay door to open. Due to the existence of connecting rods with different lengths, the rotary unlocking hinge and the free hinge rotate around the two hinge points connected with the aircraft body structure of the long connecting rod and the short connecting rod respectively during the movement of the landing gear bay door, and push the landing gear bay door to rotate and translate at the same time. With the movement of the landing gear bay door, the short connecting rod and the landing gear bay door rotate relatively at a large angle, the rotary throw sliding pin gradually separates from the rotary throw hook, and finally the landing gear bay door is disconnected with the short connecting rod. The centers of the two hinges on the landing gear bay door continue to move along the tangential direction of the connecting rod before the constraint is released, respectively, to realize the separation of the landing gear bay door and the aircraft body structure.

[0017] Due to the existence of aerodynamic force during the separation process, the aerodynamic force acts on the outside of the landing gear bay door in the first half of the opening process, preventing the landing gear bay door from opening. With the gradual rotation of the landing gear bay door, the aerodynamic force gradually changes to act on the inside of the landing gear bay door, at which time the aerodynamic force accelerates the opening of the landing gear bay door. Since the connecting rod rotary unlocking mechanism can provide the landing gear bay door with both the rotational angular velocity and the linear velocity perpendicular to the aircraft body structure, after the connecting rod and the landing gear bay door are unlocked and separated, they will continue to rotate and move away from the aircraft body structure under the action of inertia and aerodynamic force.

[0018] In the above separation mechanism, the connecting rod can be a simple straight connecting rod, or can be designed into other configurations according to the internal structure of the aircraft.

[0019] In the above separation mechanism, the hinge position can be changed, the length of the short connecting rod and the long connecting rod is adjusted, the angle between the short connecting rod and the long connecting rod and the hatch is adjusted, and then the point of action of the separation force on the hatch and the angle between the hatch and the aircraft are changed.

[0020] In the above separation mechanism, when the actuator thrust is constant, the length of the long connecting rod reversing arm and the length of the long connecting rod can be adjusted together, and then the ratio of the actuator thrust to the separation force transmitted to the hatch hinge is adjusted.

[0021] In the above separation mechanism, the actuator can be a pyrotechnic actuator, a hydraulic actuator, an electromechanical actuator, a spring actuator, a linear motor, and any other device that can provide torque or thrust power.

[0022] (Three) beneficial effects

[0023] The beneficial effects of the present application compared with the prior art are as follows:

[0024] 1. Meet the design requirements of small size and low lift-drag ratio aircraft for landing gear hatch opening mechanism, which is the inevitable technical effect generated by abandoning the traditional landing gear hatch extension and retraction mechanism and using the hatch separation mechanism.

[0025] 2. The problem of collision between the retractable landing gear hatch and the ground at the moment of landing of the aircraft is fundamentally avoided, which is the inevitable technical effect generated by separating the landing gear hatch from the aircraft in the present application.

[0026] 3. Avoid interference between the landing gear hatch and the aircraft body structure when the landing gear hatch is just opened, which is the inevitable technical effect generated by the movement relationship of the multi-link mechanism.

[0027] 4. When the landing gear hatch is in the closed state, the short connecting rod is automatically interlocked, which can reduce the number of landing gear hatch upper locks and simplify the structure design. This is the inevitable technical effect generated by the rotating unlocking hinge designed according to the movement relationship between the hatch and the connecting rod in the present application.

[0028] 5. Avoid the risk of collision between the landing gear hatch and the aircraft after the landing gear hatch is separated from the aircraft under the action of aerodynamic load, which is the inevitable technical effect generated by converting the ineffective aerodynamic resistance into effective separation power in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the landing gear hatch separation mechanism of the present application.

[0030] Figure 2 is the hinge and connecting rod included in the separation mechanism of the present application.

[0031] Figure 3This is a schematic diagram of the motion relationship between the landing gear door and the connecting rod, and the movement position of the separation mechanism when the hinge is unlocked, according to the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 As shown, an aircraft cabin door separation mechanism is characterized by comprising: an aircraft body structure 1, a landing gear cabin door 2, a short connecting rod 3, a long connecting rod 4, an actuator cylinder 5, a free hinge 6, a rotary unlocking hinge 7, and a landing gear cabin door lock 8.

[0034] The aircraft body structure 1 is connected to the short connecting rod 3, the long connecting rod 4, and the actuator cylinder 5 by hinges. The two hinged parts can rotate relative to each other. The aircraft body structure 1 is rigidly connected to the landing gear bay door lock 8 in the locked state.

[0035] The rotating unlocking hinge 7 is composed of a rotating throwing sliding pin 13 and a rotating throwing sliding sleeve 14 on the short connecting rod 3, and a rotating throwing hook 11 and a rotating throwing sliding sleeve top pin 12 on the landing gear door 2. It is used to lock the landing gear door 2 by means of the hook and pin before it is rotated open, and to release the lock after the landing gear door 2 and the short connecting rod 3 are rotated to a certain angle, so as to separate the landing gear door 2 from the aircraft body structure 1.

[0036] The free hinge 6 is composed of the free hinge sleeve 17 and the free hinge top pin 16 on the long connecting rod 4. It is mainly used to transmit the thrust from the actuator 5 to the landing gear door 2 through the reversing rocker arm 18 on the long connecting rod 4, thereby pushing the landing gear door 2 to open.

[0037] The actuator 5 is used to provide power for the movement of the landing gear door 2. One end of the actuator 5 is connected to the aircraft body structure 1, and the other end is connected to the long connecting rod 4. The linear motion of the actuator 5 is converted into the rotational motion of the long connecting rod 4 through the long connecting rod 4.

[0038] The landing gear bay door lock 8 is used to connect the landing gear bay door 2 to the aircraft fuselage structure 1, maintain the integrity of the aircraft's aerodynamic shape, and prevent the landing gear bay door 2 from moving freely. At the same time, when the landing gear bay door 2 needs to be opened, it is used to release the connection constraint with the aircraft fuselage structure 1, so that the landing gear bay door 2 can rotate around the rotation unlocking hinge 7 and the free hinge 6 simultaneously, thereby achieving separation from the aircraft fuselage structure 1.

[0039] The separation mechanism is arranged symmetrically along both sides of the landing gear door 2, and through the design of the cooperation angle and cooperation position of the counter-throw hooks 11, the counter-throw sliding sleeves 14, the counter-throw sliding pins 13 and the counter-throw sliding sleeve top pins 12, the landing gear door 2 can be parallel to the short connecting rod 3 and the long connecting rod 4 or have an included angle less than 5° when the landing gear door 2 is closed, and the landing gear door 2 is in the interlocking state with the short connecting rod 3.

[0040] The separation movement process of the aircraft door separation mechanism is as follows:

[0041] When separating, the separation power is first provided by the actuating cylinder 5 and then the long connecting rod 4 is pushed to rotate by the steering rocker arm 18, and then the power is transmitted to the landing gear door 2 through the free hinge 6, and finally the landing gear door is pushed to open; due to the existence of connecting rods with different lengths, the rotary unlocking hinge 7 and the free hinge 6 make double rotary movements around the two hinges connected with the aircraft body structure 1 through the short connecting rod 3 and the long connecting rod 4 during the movement of the landing gear door 2, until the counter-throw sliding pin 13 gradually separates from the counter-throw hook 11, and the landing gear door 2 is disconnected with the short connecting rod 3, and the hinges on the door continue to move along the tangent direction of the connecting rod where each hinge is located at the separation time, and finally the separation of the landing gear door 2 and the aircraft body structure 1 is realized.

[0042] In the first half of the opening process of the landing gear door 2, the aerodynamic force acts on the outside of the landing gear door, and the aerodynamic force prevents the opening of the door.

[0043] With the rotation of the landing gear door 2, the aerodynamic force gradually changes to act on the inside of the door, and the aerodynamic force accelerates the opening of the landing gear door.

[0044] Although the content of the present application has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present application. After reading the above content, various modifications and alternatives of the present application will be obvious to those skilled in the art. Therefore, the protection scope of the present application should be defined by the appended claims.

[0045] The content not described in detail in the specification of the present application belongs to the known technology of the skilled in the art.

Claims

1. An aircraft door separation mechanism, characterized by The application relates to an aircraft body structure (1), a landing gear door (2), a short connecting rod (3), a long connecting rod (4), an actuating cylinder (5), a free hinge (6), a rotary unlocking hinge (7) and a landing gear door lock (8). The aircraft body structure (1) is connected with the short connecting rod (3), the long connecting rod (4) and the actuating cylinder (5) through hinge connection, and the two hinge-connected parts can rotate relative to each other; the aircraft body structure (1) is rigidly connected with the landing gear door lock (8) in a locked state. The rotary unlocking hinge (7) is composed of a rotary sliding pin (13) and a rotary sliding sleeve (14) on the short connecting rod (3), a rotary hook (11) and a rotary sliding sleeve top pin (12) on the landing gear door (2), and is used for realizing locking through hook pin cooperation before the landing gear door (2) is rotated to be opened, and realizing unlocking after the landing gear door (2) and the short connecting rod (3) are rotated to a certain angle, so that the landing gear door (2) is separated from the aircraft body structure (1). The free hinge (6) is composed of a free hinge sleeve (17) and a free hinge top pin (16) on the long connecting rod (4), and is mainly used for further transmitting the thrust from the actuating cylinder (5) to the landing gear door (2) through a reversing rocker (18) arranged on the long connecting rod (4), so as to push the opening of the landing gear door (2). The actuating cylinder (5) is used for providing power for the movement of the landing gear door (2), one end of the actuating cylinder (5) is connected with the aircraft body structure (1), the other end is connected with the long connecting rod (4), and the linear movement of the actuating cylinder (5) is converted into the rotary movement of the long connecting rod (4) through the long connecting rod (4). The landing gear door lock (8) is used for connecting the landing gear door (2) with the aircraft body structure (1), maintaining the integrity of the aircraft aerodynamic shape, preventing the free movement of the landing gear door (2), and releasing the connection constraint with the aircraft body structure (1) when the landing gear door (2) needs to be opened, so that the landing gear door (2) can rotate around the rotary unlocking hinge (7) and the free hinge (6), and then realize the separation from the aircraft body structure (1).

2. The aircraft door separation mechanism of claim 1, wherein: The separation mechanism is symmetrically arranged on both sides of the landing gear door (2), and through the design of the cooperation angle and cooperation position of the rotary hook (11), the rotary sliding sleeve (14), the rotary sliding pin (13) and the rotary sliding sleeve top pin (12), the landing gear door (2) can be parallel to the short connecting rod (3) and the long connecting rod (4) or have an included angle less than 5 degrees when the landing gear door (2) is closed, and the short connecting rod (3) is in the interlocking state.

3. The aircraft door separation mechanism of any of claims 1-2, wherein: ​ 4. The method of separating an aircraft door separation mechanism of any of claims 1-3, wherein: The separation is first powered by the actuator cylinder (5) to extend, then the long connecting rod (4) is pushed to rotate by the steering rocker arm (18), and then the power is transmitted to the landing gear door (2) through the free hinge (6), and finally the landing gear door is opened. Due to the existence of connecting rods with different lengths, the rotating unlocking hinge (7) and the free hinge (6) make double rotary motion around the two hinges connected with the aircraft body structure (1) through the short connecting rod (3) and the long connecting rod (4) during the movement of the landing gear door (2), until the spin-throw sliding pin (13) gradually separates from the spin-throw hook (11), the landing gear door (2) is disconnected with the short connecting rod (3), and the hinges on the door continue to move along the tangent direction of the connecting rod at the moment of separation, and finally the separation of the landing gear door (2) and the aircraft body structure (1) is realized.

5. The method of separating an aircraft door separation mechanism of claim 4, wherein: The aerodynamic force acts on the outside of the landing gear door (2) in the first half of the opening process, and the aerodynamic force prevents the door from opening.

6. The method of separating an aircraft door separation mechanism of claim 5, wherein: With the rotation of the landing gear door (2), the aerodynamic force gradually changes to act on the inside of the door, and the aerodynamic force accelerates the opening of the landing gear door.

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