Main landing gear cabin door mechanism, aircraft and folding and unfolding method

Abstract

The invention provides a main landing gear cabin door mechanism, an aircraft and a folding and unfolding method. The main undercarriage cabin door mechanism comprises a left cabin door and a right cabin door, one end of the left cabin door is provided with a first retractable driving mechanism, one end of the right cabin door is provided with a second retractable driving mechanism, and a small cabin door is hinged to the side, close to the right cabin door, of the left cabin door; the small cabin door and the left cabin door are provided with third folding and unfolding driving mechanisms which can respectively drive the small cabin door and the left cabin door to rotate; in the first position, the left cabin door and the right cabin door are both in a vertical state, and the small cabin door and the left cabin door are folded and overlapped; and at the second position, the left cabin door, the small cabin door and the right cabin door are horizontally positioned on the same plane. The small cabin door can be independently retracted and folded, after the cabin door is opened, the folded small cabin door can reduce the windward area of the cabin door in the put-down state, the pneumatic load borne by the cabin door is reduced, and the design of a driving mechanism for retracting and releasing the cabin door is lighter.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft landing gear, and in particular to a main landing gear door mechanism, an aircraft and a retracting and extending method. Background Art

[0002] The landing gear of the aircraft is housed in the cabin of the fuselage and is provided with a door. Large landing gear makes the cabin larger, resulting in a larger door. Even if the door is designed as two doors that open side by side, its own weight is also heavy. In addition, the large door also leads to a large aerodynamic load due to its large area when lowered, which in turn makes the mechanism that drives the door to rotate more bulky and the design cost is also high. Summary of the invention

[0003] The object of the present invention is to provide a main landing gear door mechanism, an aircraft and a retracting and extending method, which can reduce the windward area of ​​the door in a lowered state and reduce the aerodynamic load on the door.

[0004] The technical solution of the present invention is: a main landing gear door mechanism, comprising a left door and a right door which are adjacently arranged and opened to form a first position or closed to form a second position, the left door being provided with a first retractable driving mechanism for driving the left door to rotate at one end away from the right door, the right door being provided with a second retractable driving mechanism for driving the right door to rotate at one end away from the left door, a small door being hinged on one side of the left door close to the right door, the small door and the left door being provided with a third retractable driving mechanism which can respectively drive the small door and the left door to rotate; in the first position, the left door and the right door are both in a vertical state, and the small door is folded and overlapped with the left door; in the second position, the left door, the small door and the right door are horizontal and located on the same plane.

[0005] Preferably, the right door has an area of ​​a, the left door has an area of ​​b, and the small door has an area of ​​c, where c+b>a.

[0006] Preferably, the first retractable and extended drive mechanism and the second retractable and extended drive mechanism both include a first connecting bracket and a first actuator cylinder, one end of the first connecting bracket is connected to the right door or the left door, the other end of the first connecting bracket is provided with a second hinge point, the first connecting bracket is also provided with a first hinge point, and one end of the first actuator cylinder is hinged to the first hinge point.

[0007] Preferably, the first connecting bracket is an arc-shaped bracket.

[0008] Preferably, the third retracting and extending driving mechanism includes a second connecting bracket, a second actuator cylinder and a third actuator cylinder, one end of the second connecting bracket is connected to the left cabin door, the other end of the second connecting bracket is provided with a third hinge point, the second connecting bracket is also provided with a fourth hinge point and a fifth hinge point, one end of the second actuator cylinder is hinged to the fifth hinge point, the other end of the second actuator cylinder is hinged to the small cabin door, and one end of the third actuator cylinder is hinged to the fourth hinge point.

[0009] Preferably, the second connecting bracket is an arc-shaped bracket.

[0010] Preferably, the left door and the right door are also provided with follow-up rotating brackets, the second retractable drive mechanism and the rotating bracket are alternately arranged on the right door, and the first retractable drive mechanism, the third retractable drive mechanism and the rotating bracket are alternately arranged on the left door.

[0011] The present invention also provides an aircraft, including a fuselage, wherein the fuselage has a cabin capable of accommodating a main landing gear, the main landing gear door mechanism is installed on the side wall of the fuselage forming the cabin, and the first retractable drive mechanism, the third retractable drive mechanism and the second retractable drive mechanism are hinged to the corresponding positions of the fuselage.

[0012] Preferably, the present invention further provides a method for retracting and extending the main landing gear of the above-mentioned aircraft, comprising: Step 1, main landing gear down: Step 1.1, drive door open: The first and third retractable driving mechanisms are activated to drive the left door to rotate outward until it is in the first position; and the second retractable driving mechanism is activated to drive the right door to rotate outward until it is in the first position; Then, the third retractable driving mechanism is started to drive the small door to rotate toward the inner side of the left door, so that the small door and the left door are overlapped inside and outside to form a first position; Step 1.2, driving the main landing gear to be lowered; Step 1.3, drive the left and right doors to close: The first retractable driving mechanism is activated to drive the left door to rotate inward until it is in the second position; and the second retractable driving mechanism is activated to drive the right door to rotate inward until it is in the second position; Step 2: Retract the main landing gear: Step 2.1, drive the left and right doors to open: The first retractable driving mechanism is activated to drive the left door to rotate outward until it is in the first position; and the second retractable driving mechanism is activated to drive the right door to rotate outward until it is in the first position; Step 2.2, driving the main landing gear to retract; Step 2.3, drive hatch closed: The third retractable driving mechanism is started to drive the small door to rotate toward the outside of the left door until the small door is flush with the left door; The first retractable driving mechanism is started to drive the left door to rotate inwardly until it is in the second position; and the second retractable driving mechanism is started to drive the right door to rotate inwardly until it is in the second position.

[0013] Compared with the related art, the present invention has the following beneficial effects: 1. The main landing gear door mechanism is designed with one of the doors (left door) as a foldable composite structure. The small door can be independently retracted and folded. After the door is opened, the folded small door can reduce the windward area of ​​the door in the lowered state and reduce the aerodynamic load on the door, making the design of the door retraction and extension drive mechanism lighter; 2. The structural design of the small door allows the left and right doors to be retracted when the main landing gear is in the down position, thus protecting the equipment in the landing gear compartment; 3. The area of ​​the right door is greatly reduced, and the small door is driven by an independent drive mechanism, which makes the design of each drive mechanism lighter and reduces the number of drive mechanisms installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A front structural schematic diagram of the main landing gear door mechanism provided by the present invention when it is in a first position; Figure 2 for Figure 1 Side view in; Figure 3 is a schematic diagram of the hatch door being opened (A is a schematic diagram of the left hatch door, the right hatch door and the small hatch door being unfolded; B is a schematic diagram of the small hatch door being folded); Figure 4 A schematic diagram showing the rear hatch in the first position with the main landing gear lowered; Figure 5 for Figure 4 A front view of Figure 6 Schematic diagram of the left and right doors in the second position after the main landing gear is lowered Figure 7 for Figure 6 Top view of the .

[0015] In the accompanying drawings: 1. left door; 2. right door; 3. first retractable drive mechanism; 31. first connecting bracket; 32. first actuator; 33. first hinge point; 34. second hinge point; 4. second retractable drive mechanism; 5. third retractable drive mechanism; 51. second connecting bracket; 52. second actuator; 53. third hinge point; 54. fourth hinge point; 55. fifth hinge point; 56. third actuator; 6. small door; 7. rotating bracket; 10. main landing gear. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0017] like Figure 1 , Figure 2 As shown, a main landing gear door mechanism provided in this embodiment includes a left door 1, a right door 2, a first retractable driving mechanism 3, a second retractable driving mechanism 4, a third retractable driving mechanism 5, a small door 6 and a rotating bracket 7.

[0018] The left door 1 and the right door 2 are arranged adjacent to each other and are opened to form a first position or closed to form a second position. A first retractable driving mechanism 3 for driving the left door 1 to rotate is provided at one end of the left door 1 away from the right door 2. A small door 6 is hingedly connected to the side of the left door 1 close to the right door 2, and a third retractable driving mechanism 5 for driving the small door 6 to rotate is provided. The first retractable driving mechanism 3, the third retractable driving mechanism 5 and the rotating bracket 7 are arranged alternately on the left door 1.

[0019] The left door 1 is provided with a notch, the size of which is equal to that of the small door 6, so that the left door 1 and the small door 6 form a complete rectangle. The right door 2 has an area a, the left door 1 has an area b, and the small door 6 has an area c, where c+b>a. The left door 1 and the right door 2 are asymmetric structures. In this embodiment, the right door 2 is only two-thirds of the traditional symmetrical door, and only one second retractable drive mechanism 4 is required to realize the door retraction. The left door 1 is combined with the first actuator 32 and the third actuator 56 on the second retractable drive mechanism 4, two actuators, to reduce the windward area of ​​the left door 1 in the lowered state after the small door 6 is folded, thereby reducing the aerodynamic load on the door.

[0020] The first retractable driving mechanism 3 includes a first connecting bracket 31 and a first actuating cylinder 32. The first connecting bracket 31 is a C-shaped arc bracket, and the arc curvature is arranged inward (such as Figure 4 The rotating bracket 7 has the same structure as the first connecting bracket 31. One end of the first connecting bracket 31 is connected to the left door 1, and the other end of the first connecting bracket 31 is provided with a second hinge point 34, and the second hinge point 34 is hinged with the fuselage to form a side wall of the cabin. The rotating bracket 7 has the same structure as the first connecting bracket 31, and one end of the rotating bracket 7 is connected to the left door 1, and the other end is hinged to the fuselage.

[0021] The first connecting bracket 31 is also provided with a first hinge point 33 , one end of the first actuating cylinder 32 is hinged to the first hinge point 33 , and the other end of the first actuating cylinder 32 is hinged to a corresponding position of the fuselage.

[0022] The third retractable driving mechanism 5 comprises a second connecting bracket 51, a second actuating cylinder 52 and a third actuating cylinder 56. One end of the second connecting bracket 51 is connected to the left door 1, and the other end of the second connecting bracket 51 is provided with a third hinge point 53, and the third hinge point 53 is hinged to the fuselage.

[0023] The second connecting bracket 51 is also provided with a fourth hinge point 54 and a fifth hinge point 55, one end of the second actuator cylinder 52 is hinged to the fifth hinge point 55, and the other end of the second actuator cylinder 52 is hinged to the small door 6, one end of the third actuator cylinder 56 is hinged to the fourth hinge point 54, and the other end of the third actuator cylinder 56 is hinged to the fuselage.

[0024] The structure of the second retractable drive mechanism 4 is the same as that of the first retractable drive mechanism 3. The second retractable drive mechanism 4 and the rotating bracket 7 are arranged on the right door 2 in an alternating manner.

[0025] The second retractable driving mechanism 4 and the rotating bracket 7 form a hinge of the right door 2. The first retractable driving mechanism 3 and the rotating bracket 7 form a hinge of the left door 1. The second retractable driving mechanism 4 drives the right door 2 to rotate, the first retractable driving mechanism 3 drives the left door 1 to rotate, and the third retractable driving mechanism 5 drives the small door 6 to rotate to form a first position and a second position.

[0026] The first actuating cylinder 32 , the second actuating cylinder 52 and the third actuating cylinder 56 each include an outer cylinder and a piston rod (such as a hydraulic cylinder) telescopically extended in the outer cylinder.

[0027] In the first position, the left door 1 and the right door 2 are both in a vertical state, and the small door 6 is folded and overlapped with the left door 1 (such as Figure 4 , Figure 5 When in the second position, the left door 1, the small door 6 and the right door 2 are horizontal and located on the same plane.

[0028] like Figure 4 As shown, the present invention also provides an aircraft, including a fuselage, wherein the fuselage has a cabin capable of accommodating a main landing gear, the above-mentioned main landing gear door mechanism is installed on the fuselage, and the first connecting bracket 31, the rotating bracket 7, the second connecting bracket 51, the first actuator cylinder 32, and the third actuator cylinder 56 are hinged to the corresponding positions of the fuselage.

[0029] like Figure 5As shown, the left door 1 is provided with a gap of the small door 6 to avoid the position of the main landing gear 10. When the main landing gear 10 is lowered, when the small door 6 is folded, the left door 1 and the right door 2 are in a closed state (such as Figure 6 , Figure 7 as shown) to protect the equipment in the cabin.

[0030] The present invention also provides a method for retracting and extending the main landing gear of the above-mentioned aircraft, comprising: Step 1, main landing gear down: Step 1.1, drive door open: like Figure 3A As shown, the first actuator 32 of the first retractable drive mechanism 3 and the third actuator 56 of the third retractable drive mechanism 5 are started to extend, so as to drive the left door 1 to rotate outward until it is in the first position; at the same time, the first actuator 32 of the second retractable drive mechanism 4 is started to extend, so as to drive the right door 2 to rotate outward until it is in the first position; like Figure 3B As shown, the second actuator 52 of the third retractable drive mechanism 5 is retracted to drive the small door 6 to rotate toward the inside of the left door 1, so that the small door 6 and the left door 1 are overlapped inside and outside to form a first position (as shown in FIG. Figure 4 , Figure 5 shown); Step 1.2, driving the actuator on the main landing gear to lower the main landing gear 10 and make it contact with the ground; Step 1.3: Drive the left door 1 and the right door 2 to close: like Figure 6 , Figure 7 As shown, the first actuator cylinder 32 of the first retracting drive mechanism 3 and the third actuator cylinder 56 of the third retracting drive mechanism 5 are started to retract, so as to drive the left door 1 to rotate inward until it is in the second position; at the same time, the first actuator cylinder 32 of the second retracting drive mechanism 4 is started to retract, so as to drive the right door 2 to rotate inward until it is in the second position.

[0031] Step 2: drive the actuator on the main landing gear to retract the main landing gear 10: Step 2.1: Drive the left door 1 and the right door 2 to open: like Figure 3B As shown, the first retractable driving mechanism 3 is started to drive the left door 1 to rotate outward until it is in the first position; and the second retractable driving mechanism 4 is started to drive the right door 2 to rotate outward until it is in the first position; Step 2.2, driving the main landing gear to retract; Step 2.3, drive hatch closed: like Figure 3AAs shown, the third retractable driving mechanism 5 is started to drive the small door 6 to rotate toward the outside of the left door 1 until the small door 6 is flush with the left door 1; like Figure 1 , Figure 2 As shown, the first retractable driving mechanism 3 is activated to drive the left door 1 to rotate inwards until it is in the second position; and the second retractable driving mechanism 4 is activated to drive the right door 2 to rotate inwards until it is in the second position. The left door 1, the small door 6 and the right door 2 are horizontal and located on the same plane.

[0032] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A main landing gear door mechanism, characterized in that: The invention comprises a left door (1) and a right door (2) which are arranged adjacent to each other and are opened to form a first position or closed to form a second position. The end of the left door (1) away from the right door (2) is provided with a first retractable driving mechanism (3) for driving the left door (1) to rotate. The end of the right door (2) away from the left door (1) is provided with a second retractable driving mechanism (4) for driving the right door (2) to rotate. A small door (6) is hingedly connected to the side of the left door (1) close to the right door (2). The small door (6) and the left door (1) are provided with a third retractable driving mechanism (5) capable of driving the small door (6) and the left door (1) to rotate respectively. In the first position, the left door (1) and the right door (2) are both in a vertical state, and the small door (6) and the left door (1) are folded and overlapped. In the second position, the left door (1), the small door (6) and the right door (2) are horizontal and located on the same plane.

2. The main landing gear door mechanism according to claim 1, characterized in that: The right door (2) has an area a, the left door (1) has an area b, and the small door (6) has an area c, where c+b>a.

3. The main landing gear door mechanism according to claim 1, characterized in that: The first retractable and extendable drive mechanism (3) and the second retractable and extendable drive mechanism (4) both comprise a first connecting bracket (31) and a first actuating cylinder (32); one end of the first connecting bracket (31) is connected to the right door (2) or the left door (1); the other end of the first connecting bracket (31) is provided with a second hinge point (34); the first connecting bracket (31) is also provided with a first hinge point (33); one end of the first actuating cylinder (32) is hinged to the first hinge point (33).

4. The main landing gear door mechanism according to claim 3, characterized in that: The first connecting bracket (31) is an arc-shaped bracket.

5. The main landing gear door mechanism according to claim 1, characterized in that: The third retractable and retractable driving mechanism (5) comprises a second connecting bracket (51), a second actuating cylinder (52) and a third actuating cylinder (56); one end of the second connecting bracket (51) is connected to the left cabin door (1); the other end of the second connecting bracket (51) is provided with a third hinge point (53); the second connecting bracket (51) is also provided with a fourth hinge point (54) and a fifth hinge point (55); one end of the second actuating cylinder (52) is hinged to the fifth hinge point (55); the other end of the second actuating cylinder (52) is hinged to the small cabin door (6); and one end of the third actuating cylinder (56) is hinged to the fourth hinge point (54).

6. The main landing gear door mechanism according to claim 5, characterized in that: The second connecting bracket (51) is an arc-shaped bracket.

7. The main landing gear door mechanism according to claim 1, characterized in that: The left door (1) and the right door (2) are also provided with a follow-up rotating bracket (7); the second retractable drive mechanism (4) and the rotating bracket (7) are arranged alternately on the right door (2); and the first retractable drive mechanism (3), the third retractable drive mechanism (5) and the rotating bracket (7) are arranged alternately on the left door (1).

8. An aircraft comprising a fuselage having a cabin capable of accommodating a main landing gear, characterized in that: It also comprises a main landing gear door mechanism as claimed in any one of claims 1 to 7, wherein the first retractable drive mechanism (3), the third retractable drive mechanism (5) and the second retractable drive mechanism (4) are hinged to corresponding positions of the fuselage.

9. A method for retracting and extending the main landing gear of an aircraft as claimed in claim 8, characterized in that: include: Step 1, main landing gear down: Step 1.1, drive door open: The first retractable drive mechanism (3) and the third retractable drive mechanism (5) are activated to drive the left door (1) to rotate outwards until it is in the first position; and the second retractable drive mechanism (4) is activated to drive the right door (2) to rotate outwards until it is in the first position; Then, the third retractable driving mechanism (5) is started to drive the small cabin door (6) to rotate toward the inside of the left cabin door (1), so that the small cabin door (6) and the left cabin door (1) are overlapped inside and outside to form a first position; Step 1.2, driving the main landing gear to be lowered; Step 1.3: Drive the left door (1) and the right door (2) to close: The first retractable driving mechanism (3) is activated to drive the left door (1) to rotate inwards until it is in the second position; and the second retractable driving mechanism (4) is simultaneously activated to drive the right door (2) to rotate inwards until it is in the second position; Step 2: Retract the main landing gear: Step 2.1: Drive the left door (1) and the right door (2) to open: The first retractable driving mechanism (3) is activated to drive the left door (1) to rotate outward until it is in the first position; and the second retractable driving mechanism (4) is simultaneously activated to drive the right door (2) to rotate outward until it is in the first position; Step 2.2, driving the main landing gear to retract; Step 2.3, drive hatch closed: Starting the third retractable driving mechanism (5) to drive the small cabin door (6) to rotate toward the outside of the left cabin door (1) until the small cabin door (6) is flush with the left cabin door (1); The first retractable driving mechanism (3) is started to drive the left door (1) to rotate inwards until it is in the second position; and the second retractable driving mechanism (4) is simultaneously started to drive the right door (2) to rotate inwards until it is in the second position.

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