CN114368474A

CN114368474A - Undercarriage cabin door sequential retraction linkage mechanism and linkage method

Info

Publication number: CN114368474A
Application number: CN202210051662.6A
Authority: CN
Inventors: 沈思颖; 贺伟; 赵大林; 吕光全; 范景峰
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2022-01-17
Filing date: 2022-01-17
Publication date: 2022-04-19
Anticipated expiration: 2042-01-17
Also published as: CN114368474B

Abstract

The utility model provides a undercarriage hatch door sequence receive and releases link gear and linkage method relates to aircraft undercarriage design field, includes: a ram; the linkage mechanism left part and the linkage mechanism right part are sleeved at two ends of the striker and are symmetrically arranged, and both the linkage mechanism left part and the linkage mechanism right part comprise an upper connecting rod, a stop connecting rod, a middle connecting rod, an upper adjusting connecting rod, a lower adjusting connecting rod and a tension spring; one end of the tension spring is fixed on a fuselage structure of the airplane and the other end of the tension spring is connected with the upper connecting rod, one end of the upper connecting rod is fixed on the fuselage structure and the other end of the upper connecting rod is connected with one end of the stopping connecting rod, the other end of the stopping connecting rod is connected with the middle position of the middle connecting rod, one end of the middle connecting rod is fixed on the fuselage structure and the other end of the middle connecting rod is connected with the upper adjusting connecting rod, the upper adjusting connecting rod is connected with the lower adjusting connecting rod, and the lower adjusting connecting rod is connected with the cabin door. The retractable cabin door has the advantages of simple structure, reliable work, no need of an additional power source for retracting and releasing the cabin door, small size, light weight and strong universality, and is suitable for the design and installation of the undercarriage and the cabin door linkage retraction and release of the unmanned aerial vehicle and the manned.

Description

Undercarriage cabin door sequential retraction linkage mechanism and linkage method

Technical Field

The disclosure relates to the field of design of aircraft undercarriages, in particular to a sequential retraction linkage mechanism and a linkage method for doors of an undercarriage.

Background

The traditional aircraft cabin door is driven by an independent actuator or an air source, the size and the weight are large, most of the traditional cabin door linkage mechanisms are of mechanical follow-up structures, and the traditional cabin door linkage mechanisms are easy to interfere with an undercarriage in the process of folding and unfolding.

Therefore, how to design a simple and reliable undercarriage and cabin door retraction mechanism to smoothly complete the retraction process of the undercarriage and the cabin door within specified conditions and time is a difficult point in the professional design work of the undercarriage.

Disclosure of Invention

In view of the above, the present disclosure provides a landing gear bay door sequential retraction linkage mechanism and a linkage method.

The present disclosure provides in one aspect a sequential retraction linkage mechanism for an aircraft landing gear bay door for linkage with the bay door and the landing gear of the aircraft, comprising: a ram; the linkage mechanism left part and the linkage mechanism right part are sleeved at two ends of the striker and are symmetrically arranged, and both the linkage mechanism left part and the linkage mechanism right part comprise an upper connecting rod, a stop connecting rod, a middle connecting rod, an upper adjusting connecting rod, a lower adjusting connecting rod and a tension spring; one end of the tension spring is fixed on a fuselage structure of the airplane, the other end of the tension spring is connected with the upper connecting rod, one end of the upper connecting rod is fixed on the fuselage structure, the other end of the upper connecting rod is connected with one end of the stopping connecting rod, the other end of the stopping connecting rod is connected with the middle position of the middle connecting rod, one end of the middle connecting rod is fixed on the fuselage structure, the other end of the middle connecting rod is connected with the upper adjusting connecting rod, the upper adjusting connecting rod is connected with the lower adjusting connecting rod, and the lower adjusting connecting rod is connected with the cabin door.

According to the embodiment of the disclosure, two ends of the striker are provided with screws, and the striker is respectively connected with the upper connecting rod at the left part of the linkage mechanism and the upper connecting rod at the right part of the linkage mechanism through the screws.

According to the embodiment of the disclosure, the joint of the two ends of the upper connecting rod, the joint of the two ends of the stop connecting rod, the fixed end of the middle connecting rod and the middle position of the middle connecting rod are both embedded with copper bushings and coated with lubricating grease.

According to an embodiment of the present disclosure, the lower adjustment link is connected to the door by a door link;

the joints of the middle connecting rods and the upper adjusting connecting rods and the joints of the lower adjusting connecting rods and the cabin door connecting rods are embedded with radial spherical plain bearings.

According to an embodiment of the present disclosure, the upper adjustment link is threadably connected to the lower adjustment link to form an assembly, the threaded connection being adjustable in length.

According to the embodiment of the present disclosure, four lugs are provided on the upper link, including a first lug, a second lug, a third lug and a fourth lug, wherein: the first lug is fixed on the machine body structure; the second lug is arranged at one side close to the first lug and is connected with the tension spring; the fourth lug is connected with a stop connecting rod; the third lug is arranged on one side close to the fourth lug and is connected with the striker.

According to the embodiment of the disclosure, the surface of the lug is provided with a convex nut stop table.

According to the embodiment of the present disclosure, a protruding stopper table is provided to a side surface of the stopper link connected to one end of the upper link.

According to the embodiment of the present disclosure, upper end monaural, middle section both arms, lower extreme oblique angle ears have been seted up on the intermediate linkage, wherein: the upper end single lug is fixed on the machine body structure; the two arms of the middle section are provided with bolt holes and are connected with a stop connecting rod through bolts; the lower end oblique angle double-lug is provided with an oblique angle relative to the middle section double-arm, and the lower end oblique angle double-lug is connected with the upper adjusting connecting rod.

According to an embodiment of the present disclosure, the tension spring has an initial tension.

According to the embodiment of the disclosure, the striker is a symmetrical piece, an arc-shaped groove is formed in the center of the striker, and the curvature radius of the arc-shaped groove is the same as the radius of the piston of the buffering support column of the undercarriage.

The invention also provides a landing gear cabin door linkage method based on the landing gear cabin door sequential retraction linkage mechanism, wherein the landing gear cabin door sequential retraction linkage mechanism, a cabin door of an airplane and a linkage retraction mode of a landing gear are in a ram impact follow-up retraction mode, and the method comprises the following steps: a retraction process: the retraction actuator works to drive the undercarriage to rotate and retract, when a buffer strut piston of the undercarriage impacts the striker, the striker is driven to retract upwards together, meanwhile, the upper connecting rod rotates around a fixed point to drive the sequential retraction linkage mechanism of the doors of the undercarriage to move, and finally, the doors are pulled to move upwards, retract and close to complete the whole sequential retraction movement; the putting-down process: the retraction actuator works to drive the undercarriage to rotate and retract, the upper connecting rod moves along with the undercarriage under the tension of the tension spring to drive the undercarriage cabin door to sequentially retract and retract the linkage mechanism to move, the upper connecting rod is limited by the stop table of the stop connecting rod to stop moving, the cabin door is opened completely, and the undercarriage continues to move until the undercarriage is put down in place to complete the whole sequential retraction movement.

Compared with the prior art, the undercarriage cabin door sequential retracting linkage mechanism and the linkage method provided by the disclosure at least have the following beneficial effects:

(1) the lifting device is simple in structure, reliable in work and easy to understand method principle, and solves the problem that mutual interference possibly exists in the folding and unfolding processes of the landing gear and the cabin door;

(2) the cabin door folding and unfolding device does not need an additional power source, and is small in size and light in weight;

(3) the universal retractable landing gear is high in universality and suitable for design and installation of most of landing gears and cabin doors with man-machines and unmanned aerial vehicles in linkage retraction.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

FIG. 1 schematically illustrates an isometric view of a landing gear door sequential retraction linkage according to an embodiment of the present disclosure;

FIG. 2 schematically illustrates a front view of an upper link according to an embodiment of the present disclosure;

FIG. 3 schematically illustrates a front view of a stop link according to an embodiment of the disclosure;

FIG. 4(a) schematically illustrates a front view of an intermediate link according to an embodiment of the disclosure;

FIG. 4(b) schematically illustrates a side view of an intermediate link according to an embodiment of the disclosure;

FIG. 5 schematically illustrates a front view of an upper adjustment link according to an embodiment of the present disclosure;

FIG. 6 schematically illustrates a front view of a lower adjustment link according to an embodiment of the present disclosure;

FIG. 7 schematically illustrates a front view of a tension spring according to an embodiment of the present disclosure;

FIG. 8 schematically illustrates a front view of a striker bar according to an embodiment of the present disclosure;

FIG. 9(a) is a schematic diagram illustrating the state of motion of a landing gear door linkage method when the landing gear is in place, according to an embodiment of the disclosure;

FIG. 9(b) is a diagram schematically illustrating the state of motion of a landing gear door linkage method when the landing gear is up at the bump-striker level/down at the break-striker level, according to an embodiment of the present disclosure;

figure 9(c) schematically illustrates a state diagram of the movement of the landing gear door linkage method when the landing gear is in the stowed position, according to an embodiment of the present disclosure.

[ description of reference ]

100-a linkage mechanism; 110-linkage left; 120-linkage right; 111-an upper link;

111A-a first tab; 111B-a second tab; 111C-third ear; 111D-fourth ear;

1111-nut locking stand; 112-a stop link; 1121-stop table; 113-intermediate link;

113A-Upper end monaural; 113B-middle double arms; 113C-lower end bevel ears;

114-an upper adjustment link; 115-lower adjusting link; 116-a tension spring; 130-a striker;

1301-an arc-shaped groove; 200-a hatch door; 210-left hatch door; 211-hatch connecting rod;

220-right hatch door; 300-a landing gear; 310-damping strut piston.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings. It is to be understood that the described embodiments are only a few, and not all, of the disclosed embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

In the present disclosure, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integral; can be mechanically connected, electrically connected or can communicate with each other; either directly or indirectly through intervening media, either internally or in any other suitable relationship. The specific meaning of the above terms in the present disclosure can be understood by those of ordinary skill in the art as appropriate.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.

Figure 1 schematically illustrates an isometric view of a landing gear door sequential retraction linkage according to an embodiment of the present disclosure.

As shown in fig. 1, a landing gear door sequential retraction and extension linkage according to this embodiment for linkage with a door 200 of an aircraft and a landing gear 300 includes: a striker 130; the linkage mechanism left portion 110 and the linkage mechanism right portion 120 are sleeved at two ends of the striker 130 and are symmetrically arranged, and the linkage mechanism left portion 110 and the linkage mechanism right portion 120 respectively comprise an upper connecting rod 111, a stop connecting rod 112, a middle connecting rod 113, an upper adjusting connecting rod 114, a lower adjusting connecting rod 115 and a tension spring 116.

One end of the tension spring 116 is fixed to the fuselage structure of the aircraft and the other end is connected to the upper connecting rod 111, one end of the upper connecting rod 111 is fixed to the fuselage structure and the other end is connected to one end of the stopping connecting rod 112, the other end of the stopping connecting rod 112 is connected to the middle position of the middle connecting rod 113, one end of the middle connecting rod 113 is fixed to the fuselage structure and the other end is connected to the upper adjusting connecting rod 114, the upper adjusting connecting rod 114 is connected to the lower adjusting connecting rod 115, and the lower adjusting connecting rod 115 is connected to the cabin door 200.

Therefore, the linkage mechanism left part 110 and the linkage mechanism right part 120 are mutually symmetrical and are connected through the striker 130, and the landing gear 300 impacts the striker 130 to generate linkage, so that the sequential linkage retraction and extension processes of the landing gear and the cabin door are completed.

The components of the landing gear door sequential retraction linkage according to the embodiments of the present disclosure will be described in detail below with reference to fig. 2 to 8, respectively.

FIG. 2 schematically illustrates a front view of an upper link according to an embodiment of the disclosure.

As shown in fig. 2, the upper link 111 is provided with four tabs including a first tab 111A, a second tab 111B, a third tab 111C and a fourth tab 111D, and the tab holes are connected to other components by bolts. The first tab 111A is fixed to the body structure, the second tab 111B is disposed on a side close to the first tab 111A and connected to the tension spring 116, the fourth tab 111D is connected to the stop link 112, and the third tab 111C is disposed on a side close to the fourth tab 111D and connected to the striker 130.

Further, the surface of the lug is provided with a convex nut stop 1111 for preventing the bolt from rotating.

FIG. 3 schematically illustrates a front view of a stop link according to an embodiment of the disclosure.

As shown in fig. 3, two tabs are respectively disposed at two ends of the stopper link 112, and the upper link 111 and the intermediate link 113 are respectively connected from top to bottom by bolts. A stopper link 112 connected to one end of the upper link 111 is provided at a side thereof with a protruding stopper 1121 for restricting movement of the upper link 111.

Fig. 4(a) schematically illustrates a front view of an intermediate link according to an embodiment of the disclosure. Fig. 4(b) schematically illustrates a side view of an intermediate link according to an embodiment of the disclosure.

As shown in fig. 4(a) and 4(B), in order to avoid the motion interference, the middle link 113 is provided with an upper end single lug 113A, a middle section double arm 113B, and a lower end oblique angle double lug 113C. The upper end single lug 113A is fixed on the fuselage structure, bolt holes are formed in the corresponding positions of each arm on the middle section double arms 113B, the stop connecting rods 112 are connected through bolts, the lower end oblique angle double lugs 113C have an oblique angle relative to the middle section double arms 113B, and the lower end oblique angle double lugs 113C are connected with the upper adjusting connecting rods 114.

FIG. 5 schematically illustrates a front view of an upper adjustment link according to an embodiment of the disclosure. Figure 6 schematically illustrates a front view of a lower adjustment link according to an embodiment of the disclosure.

As shown in fig. 5 and 6, in the disclosed embodiment, the upper adjustment link 114 is threadably connected to the lower adjustment link 115 to form an assembly, and the threaded connection is adjustable in length.

Specifically, the upper end single lug of the upper adjusting connecting rod 114 is connected with the middle connecting rod 113 through a bolt, and the lower end is provided with a blind hole internal thread. The upper end of the lower adjusting connecting rod 115 is provided with an external thread screw which is connected with the internal thread of the blind hole at the lower end of the upper adjusting connecting rod 114 in a matching way to form an adjustable connecting rod assembly.

The lower end of the lower adjusting link 115 is connected to a hatch link 211 through a bolt, and the hatch link 211 is fixedly installed on the hatch 210. Thus, the lower adjustment link 115 is connected to the hatch 200 by the hatch link 211.

In the embodiment of the present disclosure, radial spherical bearings are embedded at the connection between the middle link 113 and the upper adjusting link 114, and at the connection between the lower adjusting link 115 and the hatch link 211. That is, one end of the adjustable connecting rod assembly is connected to the lug at one end of the intermediate connecting rod 113 through a bolt and a radial spherical plain bearing, and the other end of the adjustable connecting rod assembly is connected to the hatch connecting rod 211 through a bolt and a radial spherical plain bearing. Therefore, the bolt penetrates through the radial spherical plain bearing to be connected with the part, and the adjustable connecting rod assembly can freely rotate under the designed motion relation.

In the embodiment of the present disclosure, a copper bush is embedded in the joint of the two ends of the upper link 111, the joint of the two ends of the stopper link 112, the fixed end of the middle link 113, and the middle of the middle link 113, and is coated with grease. Therefore, the connecting lug pieces of other parts are embedded with copper bushings, connected with bolts and coated with lubricating grease, so that the mechanism moves smoothly without clamping stagnation. The bolt passes through the copper bush and connects the part, guarantees that the part rotates around the junction.

It should be noted that the length of the threaded connection of the adjustable connecting rod assembly can be adjusted as required according to the situation of the in-place movement of the folding of the cabin door, so as to meet the design requirements of the folding and unfolding movement and in-place closing of the cabin door and avoid the phenomena of the movement interference and untight closing of the left and right cabin doors.

Fig. 7 schematically illustrates a front view of a tension spring according to an embodiment of the present disclosure.

As shown in fig. 7, the two ends of the tension spring 116 are hook-shaped, one end is connected to the upper connecting rod 111 through a bolt, and the other end is connected to the body structure through a bolt.

In the disclosed embodiment, the tension spring 116 has an initial tension. When the landing gear is in the lowered position, the tension spring 116 is connected, and slight tension exerts a pretension on the upper link 111 when the connection is made.

Fig. 8 schematically illustrates a front view of a striker bar according to an embodiment of the present disclosure.

As shown in fig. 8, the striker 130 has external threaded rods at both ends thereof, and the striker 130 is connected to the upper links 111 symmetrically disposed at the linkage left portion 110 and the linkage right portion 120 through the external threaded rods, respectively.

In the embodiment of the present disclosure, the striker 130 is a symmetrical member, an arc groove 1301 is formed in the center of the striker 130, the curvature radius of the arc groove 1301 is the same as the radius of the cushion strut piston 310 of the landing gear 300, and the arc groove has a guiding effect on the follow-up process after the cushion strut piston 310 collides with the striker 130.

Based on the disclosure, the disclosure also provides a landing gear door linkage method based on the landing gear door sequential retraction linkage mechanism, wherein the landing gear door sequential retraction linkage mechanism, the aircraft door 200 and the landing gear 300 are in a ram impact follow-up retraction mode. The landing gear door linkage method will be described in detail below with reference to fig. 9(a), 9(b), and 9 (c).

Fig. 9(a), 9(b), 9(c) are three stage position diagrams of a motion schematic of the landing gear door linkage method. Figure 9(a) schematically illustrates a state diagram of the motion of a landing gear door linkage method when the landing gear is in place, according to an embodiment of the disclosure. Figure 9(b) schematically illustrates a state diagram of the movement of a landing gear door linkage method when the landing gear is up to strike/down from the striker bar position, according to an embodiment of the disclosure. Figure 9(c) schematically illustrates a state diagram of the movement of the landing gear door linkage method when the landing gear is in the stowed position, according to an embodiment of the present disclosure.

As shown in fig. 9(a), 9(b) and 9(c), the landing gear door linkage method is divided into a stowing process and a lowering process, for example:

(1) a retraction process: the retraction actuator works to drive the landing gear 300 to rotate and retract, when a buffer strut piston 310 of the landing gear 300 impacts the striker 130, the striker 130 is driven to retract upwards together, meanwhile, the upper connecting rod 111 rotates around a fixed point to drive the landing gear door sequential retraction linkage mechanism 100 to move together, and finally, the door 200 is pulled to move upwards, retract and close to complete the whole sequential retraction movement;

(2) the putting-down process: the retraction actuator works to drive the landing gear 300 to rotate and put down, the upper connecting rod 111 moves along with the landing gear 300 under the tension of the tension spring 116 to drive the landing gear door sequential retraction linkage mechanism 100 to move, the upper connecting rod 111 stops moving due to the limitation of the stop platform 1121 of the stop connecting rod 112, the door 200 is opened completely, and the landing gear 300 continues to move until the landing gear 300 is put down in place, so that the whole sequential putting down movement is completed.

It should be understood that the specific order or hierarchy of steps in the process of stowing and dropping described above is an example of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not intended to be limited to the specific order or hierarchy.

The above is only an exemplary illustration, the present embodiment is not limited thereto, and several examples are given below:

in some embodiments, the landing gear door sequential retraction linkage disclosed in the above embodiments is not externally loaded in connection with other components other than the tension spring 116.

In some embodiments, the landing gear door sequential retraction linkage disclosed in the above embodiments may also form a complete linkage with at least the door link, the door and the landing gear.

In some embodiments, the sequential retraction linkage mechanism for the doors of the landing gear disclosed in the above embodiments is not limited to the retraction design of the double-open door and the nose landing gear shown in fig. 9(a), but may also be used for the retraction design of any combination of doors and landing gears, such as the double-open door and the main landing gear.

In some embodiments, the sequential retraction linkage mechanism of the landing gear door disclosed in the above embodiments may realize the up-down locking of the landing gear by an electromagnetic lock built in the retraction actuator, and a person skilled in the art may change the form of the up-down lock as required.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. From the above description, those skilled in the art should be aware of the sequential retraction linkage provided by the embodiments of the present disclosure for landing gear doors.

It is to be noted that, in the attached drawings or in the description, the implementation modes not shown or described are all the modes known by the ordinary skilled person in the field of technology, and are not described in detail. In addition, the above definitions of the various elements and methods are not limited to the specific structures, shapes or modes mentioned in the embodiments, and those skilled in the art may easily modify, replace or add them.

To sum up, the embodiment of the disclosure provides a landing gear cabin door sequential retraction linkage mechanism and a linkage method, which are used for linkage with a cabin door and a landing gear of an airplane, wherein the linkage mechanism comprises a ram, a linkage mechanism left part and a linkage mechanism right part which are symmetrically arranged, the structure is simple, the work is reliable, the principle of the method is understandable, no additional power source is needed for retraction of the cabin door, the weight is light, the universality is strong, and the landing gear sequential retraction linkage mechanism and the linkage method are suitable for design and installation of most of landing gears and cabin doors with man-machine functions and unmanned planes.

It should be noted that the sequential retraction linkage mechanism for the doors of the landing gear provided by the present disclosure has been successfully applied to the landing gear design engineering project of a certain type of aircraft.

It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.

And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various disclosed aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that is, the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. A landing gear door sequential retraction linkage for linking with a door (200) and landing gear (300) of an aircraft, comprising:

a striker (130);

the linkage mechanism left part (110) and the linkage mechanism right part (120) are sleeved at two ends of the striker (130) and are symmetrically arranged, and the linkage mechanism left part (110) and the linkage mechanism right part (120) respectively comprise an upper connecting rod (111), a stop connecting rod (112), a middle connecting rod (113), an upper adjusting connecting rod (114), a lower adjusting connecting rod (115) and a tension spring (116);

wherein, the one end of extension spring (116) is fixed in fuselage structure and the other end of aircraft and connects go up connecting rod (111), the one end of going up connecting rod (111) is fixed in fuselage structure and the other end are connected the one end of locking connecting rod (112), the other end of locking connecting rod (112) is connected the middle part position of middle connecting rod (113), the one end of middle connecting rod (113) is fixed in fuselage structure and the other end are connected go up adjusting connecting rod (114), it connects to go up adjusting connecting rod (114) adjusting connecting rod (115) down, adjusting connecting rod (115) is connected to hatch door (200) down.

2. The landing gear door sequential retraction linkage according to claim 1, wherein a screw is provided at each end of the striker (130), and the striker (130) is connected to the upper link (111) of the linkage left portion (110) and the linkage right portion (120) via the screw, respectively.

3. The landing gear door sequential retraction linkage according to claim 1, wherein a copper bush is embedded and grease is applied to the joint of the two ends of the upper link (111), the joint of the two ends of the stop link (112), the fixed end of the middle link (113) and the middle position of the middle link (113).

4. The landing gear door sequential retraction linkage according to claim 1, wherein the lower adjustment link (115) is connected to the door (200) by a door link (211);

the connection part of the middle connecting rod (113) and the upper adjusting connecting rod (114) and the connection part of the lower adjusting connecting rod (115) and the cabin door connecting rod (211) are embedded with radial spherical bearings.

5. The landing gear door sequential retraction linkage according to claim 1, wherein the upper adjustment link (114) is threadedly connected to the lower adjustment link (115) to form an assembly, the threaded connection being adjustable in length.

6. The landing gear door sequential retraction linkage according to claim 1, wherein the upper link (111) is provided with four tabs, including a first tab (111A), a second tab (111B), a third tab (111C) and a fourth tab (111D), wherein:

the first tab (111A) is secured to the fuselage structure;

the second lug plate (111B) is arranged on one side close to the first lug plate (111A) and is connected with the tension spring (116);

the fourth lug (111D) is connected with the stop link (112);

the third lug (111C) is arranged on one side close to the fourth lug (111D) and is connected with the striker (130).

7. The landing gear door sequential retraction linkage according to claim 6, wherein the surface of the tab is provided with a convex nut stop (1111).

8. The landing gear door sequential retraction linkage according to claim 1, wherein a protruding stop shelf (1121) is provided on the side of the stop link (112) at the end connected to the upper link (111).

9. The landing gear door sequential retraction linkage according to claim 1, wherein the intermediate link (113) is provided with an upper end single lug (113A), a middle section double arm (113B), and a lower end bevel angle double lug (113C), wherein:

the upper end monaural (113A) is fixed to the fuselage structure;

the middle section double arms (113B) are provided with bolt holes and connected with the stop connecting rods (112) through bolts;

the lower end oblique angle double lug (113C) has an oblique angle relative to the middle section double arm (113B), and the lower end oblique angle double lug (113C) is connected with the upper adjusting connecting rod (114).

10. The landing gear door sequential retraction linkage according to claim 1, wherein the tension spring (116) has an initial tension.

11. The landing gear door sequential retraction linkage according to claim 1, wherein the striker (130) is a symmetrical piece, an arc-shaped groove (1301) is formed in the center of the striker (130), and the radius of curvature of the arc-shaped groove (1301) is the same as the radius of the cushion strut piston (310) of the landing gear (300).

12. A landing gear door linkage method based on the landing gear door sequential retraction linkage according to any of claims 1 to 11, wherein the retraction linkage of the landing gear door sequential retraction linkage with the door (200) of the aircraft and the landing gear (300) is in the form of ram impact follow-up retraction, the method comprising:

a retraction process: the retraction actuator works to drive the landing gear (300) to rotate and retract, when a buffer strut piston (310) of the landing gear (300) impacts the striker (130), the striker (130) is driven to retract upwards together, meanwhile, the upper connecting rod (111) rotates around a fixed point, the landing gear door sequential retraction linkage mechanism is driven to move, finally, the door (200) is pulled to move upwards, retract and close, and the whole sequential retraction movement is completed;

the putting-down process: the retractable actuator works and drives the undercarriage (300) to rotate and release, the upper connecting rod (111) is received tension spring (116) tension force is along with the undercarriage (300) moves together, drives the undercarriage door sequence retractable linkage mechanism to move, the upper connecting rod (111) is received the stop table (1121) of the stop connecting rod (112) limits and stops moving, the door (200) is opened and finishes, the undercarriage (300) continues to move until being put down to the right place, and the whole sequence put down movement is completed.