Side-by-side aircraft cabin door

Abstract

The invention belongs to the technical field of aircraft structure design, and particularly relates to a split aircraft cabin door. The device comprises an outer side cabin door, an inner side cabin door, a driving mechanism, a lock mechanism and a lap joint device, the driving mechanism is hinged to the outer side door pull rod and the inner side door pull rod at the same time through rocker arms, the outer side door pull rod is hinged to the outer side cabin door, the inner side door pull rod is hinged to the inner side cabin door, the outer side cabin door is closed in place firstly, then the inner side cabin door is closed in place, and the outer side cabin door is limited through a lap joint device. The lock hook is in butt joint with the lock ring. Through lap joint load transfer and centralized locking, the number of lock mechanisms is remarkably reduced, and effective weight reduction and cost reduction are achieved while high reliability is guaranteed.

Description

Technical Field

[0001] This application belongs to the field of aircraft structural design technology, and specifically relates to a double-opening aircraft cabin door. Background Technology

[0002] In the aviation industry, large aircraft require large external doors to provide access for loading, storing, stowing, or airdropping cargo, landing gear, and equipment. These doors include, but are not limited to, landing gear doors, airdrop cargo doors, and equipment doors. Due to their enormous size and the frequent opening and closing during flight, the system composition and automatic control logic of these doors are typically very complex, posing a significant design challenge and a key focus in aircraft structural design.

[0003] In existing technologies, such large-sized cabin doors mostly adopt a single-leaf integral structure or a simple multi-leaf linkage structure. During aircraft flight, the cabin door needs to withstand enormous aerodynamic loads. Existing cabin door designs have revealed several significant problems in long-term use:

[0004] The first issue is structural deformation and reliability. When a large single-leaf cabin door is closed during flight, the uneven distribution of aerodynamic loads can easily cause significant deformation. This not only affects the aircraft's aerodynamic performance but may also cause fatigue damage to the door itself and its surrounding structures. For example, a certain type of aircraft experienced excessive deformation of its large-scale cabin door during flight closure, which consequently affected the aircraft's flight performance.

[0005] Secondly, there are malfunctions such as accidental opening and inability to open, making the locking reliability of the cargo doors crucial. Several aircraft have experienced serious incidents of landing gear doors and cargo doors opening unexpectedly during flight, and there have also been instances where they failed to open properly due to mechanism jamming during missions. These malfunctions can lead to structural damage to the fuselage, affect the normal retraction and extension of the landing gear, hinder cargo airdrops or weapons deployments, and directly threaten flight safety and mission success or failure.

[0006] To ensure the rigidity and locking reliability of large hatches, traditional designs often require a large number of locking mechanisms and drive units. This not only increases the complexity and weight of the system, but also leads to higher manufacturing and maintenance costs. Summary of the Invention

[0007] To address the aforementioned issues, this application provides a double-opening aircraft door, which mainly includes an outer door, an inner door, a drive mechanism, a locking mechanism, and a connecting device.

[0008] The drive mechanism simultaneously hinges the outer door lever and the inner door lever via a rocker arm. The outer door lever is hinged to the outer hatch, and the inner door lever is hinged to the inner hatch. The outer hatch closes to its final position first, and the inner hatch closes to its final position later. The outer hatch is limited by a connecting device. The locking ring and locking mechanism on the inner hatch are located on the fuselage and have a locking hook that engages with the locking ring.

[0009] Preferably, the outer hatch is connected to the fuselage via multiple outer hatch hinges arranged on one side of the hatch, and the inner hatch is connected to the fuselage via multiple inner hatch hinges arranged on the other side of the hatch.

[0010] Preferably, both the outer and inner hatches are constructed with a skeleton structure consisting of multiple longitudinal and transverse beams, and an outer skin is laid on the outside of the skeleton structure.

[0011] Preferably, one end of the rocker arm of the drive mechanism is hinged to the fuselage, and the other end is hinged to the outer door lever and the inner door lever respectively through two double ears. The door actuator is hinged in the middle of the rocker arm.

[0012] Preferably, the locking mechanism further includes a locking actuator, a locking key, a locking clamp, a locking key torsion spring, and a locking torsion spring. The locking clamp has a notch, and the locking hook is hinged to the locking clamp via the locking torsion spring. The hook of the locking hook can open or close the notch. The locking key is hinged to the locking clamp via the locking key torsion spring. One end of the locking key abuts against the back protrusion of the locking hook, and the other end abuts against the output shaft end of the locking actuator.

[0013] Preferably, there are two locking mechanisms, located at opposite ends of the hatch.

[0014] Preferably, the overlapping device includes an outer door support fixed to the outer hatch and an inner door support fixed to the inner hatch. An overlapping bolt extends from the outer door support to the inner door support and is fitted with an overlapping bolt bushing. An overlapping boss extends from the inner door support to the outer door support, and the overlapping bolt bushing can overlap the overlapping boss when the hatch is closed.

[0015] Preferably, multiple overlapping devices are provided at the junction of the outer and inner hatches.

[0016] This application significantly reduces the number of locking mechanisms by using overlapping load transfer and centralized locking, achieving effective weight reduction and cost reduction while ensuring high reliability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the double-opening aircraft cabin door of this application.

[0018] Figure 2 This is a schematic diagram of the drive mechanism.

[0019] Figure 3 A schematic diagram of the locking mechanism.

[0020] Figure 4 This is a schematic diagram of the lock mechanism.

[0021] Figure 5 This is a schematic diagram of the overlapping device structure.

[0022] 1-Outer hatch, 2-Inner hatch, 3-Drive mechanism, 4-Locking mechanism, 5-Outer hatch hinge, 6-Inner hatch hinge, 7-Interlocking device, 21-Locking ring, 31-Outer door lever, 32-Inner door lever, 33-Rocker arm, 34-Hatch actuating cylinder, 41-Locking hook, 42-Locking actuating cylinder, 43-Locking key, 44-Locking clamp, 45-Locking key torsion spring, 46-Locking torsion spring, 71-Outer door support, 72-Inner door support, 73-Interlocking bolt bushing, 74-Interlocking boss. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0024] This application provides a double-opening aircraft cabin door, such as Figures 1-5 As shown, it mainly includes an outer hatch 1, an inner hatch 2, a drive mechanism 3, a locking mechanism 4, and a connecting device 7;

[0025] The drive mechanism 3 simultaneously hinges the outer door lever 31 and the inner door lever 32 via the rocker arm 33. The outer door lever 31 is hinged to the outer hatch 1, and the inner door lever 32 is hinged to the inner hatch 2. The outer hatch 1 closes to the position first, and the inner hatch 2 closes to the position later. The outer hatch 1 is limited by the interlocking device 7. The locking ring 21 on the inner hatch 2 and the locking mechanism 4 are set on the fuselage and have a locking hook 41 that docks with the locking ring 21.

[0026] When the hatches of this application are closed, the outer hatch moves faster than the inner hatch, reaching the closed position first, followed by the inner hatch. The outer hatch is attached to the inner hatch via an intermediate connecting device; therefore, only a locking mechanism needs to be installed on the inner hatch to lock it. The aerodynamic load of the outer hatch is transferred to the inner hatch via the connecting device; then, the load is transferred and distributed to the fuselage structure through the hinges and locking mechanisms of the two hatches. The hatch opening process is as follows: after the locking mechanism 4 unlocks, the drive mechanism 3 opens the hatch outwards, and the actuator of the drive mechanism 3 holds the hatch in the open position. The closing process is the reverse of the opening process.

[0027] The proposed double-opening hatch opens outwards, meeting the opening requirements for large-size hatches. Its low ground clearance when open effectively reduces the aircraft's altitude. When closed, the two hatches overlap, requiring only a locking mechanism on the overlapping door, significantly reducing the number of locking mechanisms and resulting in higher reliability and weight reduction. Both doors are simultaneously driven by two actuators, further reducing the number of actuators and providing significant economic benefits. The overlapping mechanism only bears aerodynamic loads perpendicular to the skin, not transmitting the overall aircraft load. The two doors exhibit good deformation coordination characteristics, meeting the step and clearance requirements during closure. These measures ensure high safety and reliability, lightweight design, and a significant low-cost advantage for this large-size hatch.

[0028] In some alternative embodiments, the outer hatch 1 is connected to the fuselage via a plurality of outer hatch hinges 5 arranged on one side of the hatch, and the inner hatch 2 is connected to the fuselage via a plurality of inner hatch hinges 6 arranged on the other side of the hatch.

[0029] In this embodiment, the hinges for the outer and inner cabin doors are respectively located on both sides of the doors. This layout allows the two doors to rotate symmetrically outwards from the fuselage, like a double door. The split-opening design allows the doors to fit snugly against the sides of the fuselage when open, minimizing encroachment on the internal space and facilitating the placement of large equipment. Furthermore, the symmetrical distribution of the doors after opening helps maintain the aircraft's aerodynamic balance.

[0030] In some alternative embodiments, both the outer hatch 1 and the inner hatch 2 are constructed with a skeleton structure consisting of multiple longitudinal beams and transverse beams, and an outer skin is laid on the outside of the skeleton structure.

[0031] In this embodiment, the longitudinal beams along the length of the hatch and the transverse beams along the width of the hatch form a skeleton that jointly bears and transmits the load, while the outer skin is used to form a smooth aerodynamic shape and withstand local aerodynamic pressure. In an alternative embodiment, a composite material integral molding process, such as carbon fiber reinforced plastic, can be used to manufacture the beams, ribs, and skin as a single unit, which can further reduce weight.

[0032] In some alternative embodiments, one end of the rocker arm 33 of the drive mechanism 3 is hinged to the fuselage, and the other end is hinged to the outer door lever 31 and the inner door lever 32 respectively through two double ears. The door actuator cylinder 34 is hinged in the middle of the rocker arm 33.

[0033] In this embodiment, the rocker arm acts as a lever, with one end serving as the fulcrum (hinged to the fuselage), the middle point as the force point (connected to the actuating cylinder), and the other end as the load point (also connected to the inner and outer door levers). The extension and retraction motion of the actuating cylinder is converted into the pushing and pulling motion of the levers through the rocker arm, thereby driving the hatch. Since the inner and outer levers are both connected to the same point on the rocker arm, absolute synchronization when they are driven is ensured, avoiding structural interference or additional stress that may occur due to asynchrony.

[0034] In some alternative embodiments, the locking mechanism 4 further includes a locking actuator 42, a locking key 43, a locking clamp 44, a locking key torsion spring 45, and a locking torsion spring 46. The locking clamp 44 has a notch, and a locking hook 41 is hinged to the locking clamp 44 via the locking torsion spring 46. The hook of the locking hook 41 can open or close the notch. The locking key 43 is hinged to the locking clamp 44 via the locking key torsion spring 45. One end of the locking key 43 abuts against the back protrusion of the locking hook 41, and the other end abuts against the output shaft end of the locking actuator 42.

[0035] In this embodiment, reference Figure 4 The locking hook 41 opens the notch under the action of the locking torsion spring 46, releasing the locking ring. When locking, the output shaft of the locking actuator 42 extends and pushes the locking key 43 to deflect. The locking key pushes the locking hook 41 to deflect until the end of the locking key 43 is engaged with the protrusion of the locking hook 41. At this time, the locking hook 41 closes the notch and limits the locking ring within the notch.

[0036] In some alternative embodiments, there are two locking mechanisms 4, located at opposite ends of the hatch. This embodiment arranges one locking mechanism at each end of the hatch, ensuring that the large hatch will not deform or vibrate when subjected to aerodynamic loads, and that the locking is secure and reliable.

[0037] In some alternative embodiments, the overlapping device 7 includes an outer door support 71 fixed to the outer door 1 and an inner door support 72 fixed to the inner door 2. The outer door support 71 has an overlapping bolt extending towards the inner door support, and an overlapping bolt bushing 73 is fitted on it. The inner door support 72 has an overlapping boss 74 extending towards the outer door support. The overlapping bolt bushing 73 can overlap on the overlapping boss 74 when the door is closed.

[0038] In some alternative embodiments, multiple overlapping devices 7 are provided at the junction of the outer hatch 1 and the inner hatch 2.

[0039] In this embodiment, the lap bolt bushing and lap boss work together to form an interface that can transfer loads while allowing for minor relative displacements (such as thermal expansion and contraction or structural deformation). Multiple lap points along the hatch joint can evenly transfer the load of the outer hatch to the entire span of the inner hatch. Multiple lap points avoid stress concentration and ensure structural integrity.

[0040] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A split aircraft cabin door, characterized in that, The door includes an outer door (1), an inner door (2), a driving mechanism (3), a locking mechanism (4) and a lapping device (7). The driving mechanism (3) is connected to the outer door pull rod (31) and the inner door pull rod (32) through a rocker arm (33). The outer door pull rod (31) is connected to the outer door (1), and the inner door pull rod (32) is connected to the inner door (2). The outer door (1) is closed first, and the inner door (2) is closed later. The outer door (1) is limited by the lapping device (7). The locking ring (21) on the inner door (2) is connected to the locking hook (41) of the locking mechanism (4).

2. The split airplane cabin door of Claim 1, wherein, The outer door (1) is connected to the fuselage through a plurality of outer door hinges (5) arranged on one side of the door. The inner door (2) is connected to the fuselage through a plurality of inner door hinges (6) arranged on the other side of the door.

3. The split airplane cabin door of Claim 1, wherein, The outer door (1) and the inner door (2) are both composed of a plurality of longitudinal beams and cross beams to form a skeleton structure, and an outer skin is laid outside the skeleton structure.

4. The split airplane cabin door of Claim 1, wherein, One end of the rocker arm (33) of the driving mechanism (3) is connected to the fuselage, and the other end is connected to the outer door pull rod (31) and the inner door pull rod (32) through two double ears. The middle of the rocker arm (33) is connected to the door actuator cylinder (34).

5. The split airplane cabin door of Claim 1, wherein, The locking mechanism (4) further includes a locking actuator cylinder (42), a locking key (43), a locking clamp (44), a locking key torsional spring (45) and a locking torsional spring (46). The locking clamp (44) has an opening. The locking hook (41) is connected to the locking clamp (44) through the locking torsional spring (46). The hook of the locking hook (41) can open or close the opening. The locking key (43) is connected to the locking clamp (44) through the locking key torsional spring (45). One end of the locking key (43) abuts against the back protrusion of the locking hook (41), and the other end abuts against the output shaft end of the locking actuator cylinder (42).

6. The split airplane cabin door of Claim 5, wherein, The locking mechanism (4) has two, respectively located at both ends of the door.

7. The split airplane cabin door of Claim 1, wherein, The lapping device (7) includes an outer door support (71) fixed to the outer door (1) and an inner door support (72) fixed to the inner door (2). The outer door support (71) extends towards the inner door support and has a lapping bolt with a lapping bolt bushing (73) sleeved thereon. The inner door support (72) extends towards the outer door support and has a lapping boss (74). The lapping bolt bushing (73) can be lapped on the lapping boss (74) when the door is closed.

8. The split airplane cabin door of Claim 7, wherein, The lapping device (7) is provided with a plurality of lapping bosses (74) along the joint of the outer door (1) and the inner door (2).

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