Tail boom retracting and releasing system with centering mechanism

Abstract

The invention relates to the technical field of aircraft tail boom retracting and releasing systems, and particularly discloses a tail boom retracting and releasing system with a centering mechanism, which comprises a tail boom strut actuating cylinder connected with an aircraft body, and a lateral spring pull rod connected with the upper part of the tail boom strut actuating cylinder, the lower part of the tail boom strut actuating cylinder is respectively connected with a tail boom retracting and releasing actuating cylinder, a cabin door pull rod mechanism and a tail boom strut uplock, the free end of the cabin door pull rod mechanism is connected with an aircraft cabin door, the free end of the tail boom retracting and releasing actuating cylinder is connected with a rotating rocker arm mechanism, and the other end of the rotating rocker arm mechanism is connected with a course spring pull rod. According to the tail boom retracting and releasing system, an aircraft hydraulic system serves as energy, the tail boom retracting and releasing system which is simple in structure, reliable, stable and high in self-adaptability and has an automatic adjusting and centering function is provided, and the technical problems that an existing tail boom retracting and releasing system is complex in structure, poor in stability, weak in interchangeability, poor in environmental adaptability and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft tail support retracting and extending systems, and in particular to a tail support retracting and extending system with a self-centering mechanism. Background Art

[0002] The tail support retractable system refers to a cabin structure that is connected to the rear of the aircraft fuselage or independently set on the wings on both sides of the fuselage. The diameter is significantly smaller than the fuselage. It partially plays the role of the rear fuselage, and the tail is installed at the end, so it also plays the role of a lever. The tail support retractable system is an important part of the aircraft structure and is related to the safety of the aircraft in the air and the safety of the crew and ground loading.

[0003] For transport aircraft, the tail support mechanism used is mostly the front retractable tail support, which is located in the fuselage behind the landing gear compartments on both sides and in front of the cargo ramp. When in use, it is released from the storage compartment inside the fuselage, and the front and rear tail support doors are opened in linkage. The aircraft hydraulic system is used as energy, and hydraulic pressure is used to provide support for the fuselage. This tail support mechanism consists of a hydraulic support hinged to a pivot as the support rod body. After positioning, it can be extended and retracted with the help of hydraulic pressure from the hydraulic system to reach the ground for support or shortened for retraction into the storage compartment. The tail support retracting actuator is used as a driving mechanism, which uses hydraulic pressure from the hydraulic system to extend or shorten, and is connected to the main support through the ear piece to drive the main support to be lowered or retracted. The spring rod is elastically unloaded when the main support is in the vertical direction, and provides elastic force to drive the support to return to the original position when the support is offset, realizing self-calibration function and certain deviation correction function. At the same time, the main support is linked with a set of spatial rod system structures to realize the linkage retraction and extension of the front and rear tail support doors and the main support. Although the front-retracting-rod-type tail support has the advantages of low price and good stability in some cases, its complex structure, high failure rate, maintenance difficulty and maintenance cost limit its widespread application.

[0004] For helicopters, the tail support system refers to the support rod under the helicopter tail boom, which is used to prevent the helicopter's center of gravity from tilting backward and causing damage to the helicopter's tail boom, tail rotor, etc. The helicopter tail support rod currently used in the prior art is simply to install the support rod under the tail of the helicopter, and most of them have simple structures and are fixed structures. At present, the tail support used on domestic helicopters is a mechanical spring or elastic block structure that is fixed and cannot be retracted, and generates support force through deformation. At this stage, visual inspection can only be relied on for inspection and maintenance before and after flight, and the reliability of the mechanism cannot be guaranteed. Often, as the use cycle increases, the mechanical spring or elastic block will be deformed and lose its effectiveness, which on the one hand increases the use cost of the helicopter, and on the other hand reduces the rapid maintainability of the helicopter.

[0005] With the rapid development of domestic aircraft technology, many new heavy-weight, highly maneuverable aircraft have gradually appeared in the public eye. In order to ensure the aircraft's air flight safety and the safety of the crew and ground loading, a new tail strut retraction and extension system is urgently needed to ensure the stability of the aircraft. Summary of the invention

[0006] The object of the present invention is to provide a tail support retracting and extending system with a self-centering mechanism which has a simple structure, is reliable and stable, and has strong adaptability.

[0007] The present invention is achieved through the following technical scheme: a tail strut retracting and extending system with a self-contained return-to-center mechanism, comprising a tail strut pillar actuator cylinder connected to an aircraft fuselage, the upper portion of the tail strut pillar actuator cylinder being connected to a lateral spring pull rod, the lower portion of the tail strut pillar actuator cylinder being respectively connected to a tail strut retracting and extending actuator cylinder, a cabin door pull rod mechanism, and a tail strut pillar upper lock, the free end of the cabin door pull rod mechanism being connected to an aircraft cabin door, the free end of the tail strut retracting and extending actuator cylinder being connected to a rotating rocker arm mechanism, and the other end of the rotating rocker arm mechanism being connected to a heading spring pull rod.

[0008] The working principle of this technical solution is that the aircraft hydraulic system is used as an energy source. The tail strut upper lock plays a locking function in the system. The tail strut retraction and extension actuator controls the retraction and extension of the system. The tail strut actuator plays a supporting role after being extended to the bottom. The heading spring pull rod and the lateral spring pull rod support the tail strut actuator and quickly return to the center. The door pull rod mechanism realizes the linkage retraction and extension of the tail strut actuator and the tail strut door. The overall system has the advantages of stable and reliable operation, rich functions, simple structure and strong environmental adaptability.

[0009] To better realize the present invention, further, the tail support pillar upper lock includes a lock shell, an unlocking actuator cylinder is installed on one side of the lock shell, the extended end of the unlocking actuator cylinder is abutted with an actuating rocker arm, the action rocker arm is installed on a spline shaft, the spline shaft is embedded under the lock shell, and a switch rocker arm is installed on the other end of the spline shaft, the switch rocker arm is abutted with a position sensor arranged on the other side of the lock shell, a lock hook is provided at the lower part of the shell, the lock hook is connected to a stopping rocker arm through at least two reset springs, and the other end of the stopping rocker arm is connected to the spline shaft.

[0010] In order to better implement the present invention, further, the unlocking actuator is also equipped with a return spring.

[0011] In order to better realize the present invention, further, both ends of the tail strut retracting actuator are provided with radial spherical bearings, the radial spherical bearings at both ends of the tail strut retracting actuator are respectively connected to the rotating rocker arm mechanism and the tail strut support actuator, and the upper and lower parts of the tail strut retracting actuator are also respectively provided with an extension nozzle and a retraction nozzle connected by a pipeline, and a stroke displacement sensor is provided on one side of the lower part of the tail strut retracting actuator.

[0012] In order to better realize the present invention, further, a joint bearing is arranged on the top of the tail strut pillar actuator cylinder, and the tail strut pillar actuator cylinder is connected to the fuselage of the aircraft through the upper joint bearing; a second mechanical opening is arranged on the upper side of the tail strut pillar actuator cylinder, and the second mechanical interface on the tail strut pillar actuator cylinder is connected to the end of the lateral spring pull rod; the lower side of the tail strut pillar actuator cylinder is also provided with a first mechanical opening connected to the radial joint bearing of the tail strut retracting and extending actuator cylinder, a locking ring cooperating with the locking hook, and a door pull rod joint connected to one end of the door pull rod mechanism.

[0013] In order to better implement the present invention, further, a chassis is also provided at the bottom of the tail support strut actuator.

[0014] In order to better realize the present invention, further, bearings are provided at both ends of the lateral spring pull rod, and the lateral spring pull rod is connected to the second mechanical interface on the tail support pillar actuator cylinder through the bearings at the end. The lateral spring pull rod includes an outer cylinder and an inner cylinder nested together in the opening direction, and stop blocks passing through the outer cylinder and the inner cylinder are provided at the openings of the outer cylinder and the inner cylinder, and a spring is provided between the two stop blocks.

[0015] To better implement the present invention, further, the heading spring pull rod has the same structure as the lateral spring pull rod, and the heading spring pull rod is connected to the rotating rocker arm mechanism through a bearing at the end.

[0016] To better implement the present invention, further, the door pull rod mechanism includes a middle pull rod, one end of the pull rod is provided with a strut end joint connected to the tail strut strut actuator, and the other end of the pull rod is provided with a door end joint connected to the tail strut door.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] (1) The present invention uses the aircraft hydraulic system as energy source, the tail strut upper lock plays a locking function in the system, the tail strut retraction and extension cylinder controls the retraction and extension of the system, the tail strut actuator plays a supporting role after being extended to the bottom, the heading spring pull rod and the lateral spring pull rod play a supporting role for the tail strut actuator and the rapid return function, and the door pull rod mechanism realizes the linkage retraction and extension of the tail strut actuator and the tail strut door. The overall system has the advantages of stable and reliable operation, rich functions, simple structure and strong environmental adaptability;

[0019] (2) The tail support pillar upper lock provided by the present invention has a simple overall mechanical principle and works stably and reliably; the tail support retraction actuator and the tail support pillar actuator both adopt a traditional structure, and the extension of the piston rod is achieved by supplying hydraulic oil to the rodless chamber, and the retraction of the piston rod is achieved by supplying hydraulic oil to the rod chamber, which has the advantages of simple overall structure, strong operability, safe and stable operation, etc.

[0020] (3) The present invention forms a return-to-center mechanism of the tail strut retracting and extending system through a heading spring pull rod and a lateral spring pull rod, which is mainly used to support the tail strut strut actuator and the rapid return-to-center function. It adopts a spring tension and compression rod form, which is elastically unloaded when the tail strut strut actuator is in the vertical neutral position, and provides elastic force to drive the tail strut strut actuator to return to the center position when the tail strut strut actuator is offset. When the tail strut strut actuator is retracted, the spring tension pulls the deflected tail strut strut actuator back to the center position, realizing the automatic return-to-center function. The existence of the return-to-center mechanism improves the stability and environmental adaptability of the tail strut retracting and extending system, and enhances the universal applicability of the system;

[0021] (4) The present invention is based on the hydraulic system of the aircraft as energy source. Most of the components adopt the traditional hydraulic actuator form. The biggest problem is the sealing of the product structure. The present invention considers the use of fixed seals (no relative movement) and movable combined seals (relative movement) to solve this problem at the beginning of the design, ensuring the reliability of the product in terms of airtightness, pressure resistance and sealing, and providing a strong guarantee for the normal operation of the system. It solves the technical problems of the existing tail support retracting and releasing system, such as complex structure, poor stability, weak interchangeability and poor environmental adaptability, and can be widely used in aviation, aerospace, construction, road and bridge and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments with reference to the following drawings:

[0023] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention in a folded state;

[0024] Figure 2 It is a three-dimensional structural schematic diagram of the present invention in a laid-down state;

[0025] Figure 3 It is a schematic diagram of the three-dimensional structure of the upper lock from the southeast perspective in the present invention;

[0026] Figure 4 It is a schematic diagram of the three-dimensional structure of the upper lock from a northwest perspective in the present invention;

[0027] Figure 5 It is a structural schematic diagram of the tail support retracting and extending actuator in the present invention;

[0028] Figure 6It is a structural schematic diagram of the tail support pillar actuator in the present invention;

[0029] Figure 7 It is a schematic diagram of the planar structure of the lateral spring pull rod or the heading spring pull rod in the present invention;

[0030] Figure 8 It is a schematic diagram of the cross-sectional structure of the lateral spring pull rod or the heading spring pull rod in the present invention;

[0031] Fig. 9 It is a three-dimensional structural schematic diagram of the rotary rocker arm mechanism of the present invention;

[0032] Fig.10 It is a schematic diagram of the three-dimensional structure of the door pull rod mechanism in the present invention.

[0033] Among them: 1-tail support pillar actuator, 2-lateral spring pull rod, 3-tail support retracting actuator, 4-course spring pull rod, 5-tail support pillar upper lock, 6-rotation rocker arm mechanism, 7-door pull rod mechanism, 8-unlocking actuator, 9-actuating rocker arm, 10-switch rocker arm, 11-lock hook, 12-spline shaft, 13-position sensor, 14-reset tension spring, 15-stop rocker arm, 16-lock housing, 17-radial spherical bearing, 18-extending nozzle, 19-retracting nozzle, 20-stroke displacement sensor, 21-spherical bearing, 22-first mechanical interface, 23-locking ring, 24-door pull rod joint, 25-chassis, 26-second mechanical interface, 27-bearing, 28-spring, 29-stop block, 30-outer cylinder, 31-inner cylinder, 32-pillar end joint, 33-pull rod, 34-door end joint. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, it is limited that "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly including one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Embodiment 1:

[0038] The main structure of this embodiment is as follows: Figure 1 , Figure 2 As shown, it includes a tail strut actuator 1 connected to the aircraft fuselage, the upper part of the tail strut actuator 1 is connected to a lateral spring pull rod 2, the lower part of the tail strut actuator 1 is respectively connected to a tail strut retracting actuator 3, a cabin door pull rod mechanism 7, and a tail strut upper lock 5, the free end of the cabin door pull rod mechanism 7 is connected to the aircraft cabin door, the free end of the tail strut retracting actuator 3 is connected to a rotating rocker arm mechanism 6, and the other end of the rotating rocker arm mechanism 6 is connected to a heading spring pull rod 4.

[0039] like Figure 6As shown, a spherical bearing 21 is provided on the top of the tail strut actuator 1, and the tail strut actuator 1 is connected to the fuselage of the aircraft through the upper spherical bearing 21; a second mechanical port 26 is provided on the upper side of the tail strut actuator 1, and the second mechanical interface 26 on the tail strut actuator 1 is connected to the end of the lateral spring pull rod 2; the lower side of the tail strut actuator 1 is also provided with a first mechanical port 22 connected to the radial spherical bearing 17 of the tail strut retracting actuator 3, a locking ring 23 cooperating with the locking hook 11, and a door pull rod joint 24 connected to one end of the door pull rod mechanism 7. : The tail strut actuator 1 is in a retracted state during the flight phase of the aircraft and is fixed in the cabin by the tail strut upper lock 5, realizing the mechanical locking function of the tail strut system and triggering the locking signal of the mechanical lock; during the docking phase of the aircraft, under the action of hydraulic pressure, the tail strut upper lock 5 is unlocked, and the tail strut actuator 1 is in a vertical state driven by the tail strut retraction actuator 3, and the tail strut actuator 1 is normally extended under the action of hydraulic pressure. When the tail strut actuator 1 is extended into place, the chassis 25 plays a supporting role under the action of hydraulic pressure.

[0040] The specific working process is as follows: when the system is in the retracted state and unlocked, first, the unlocking chamber of the unlocking cylinder 8 of the tail support pillar upper lock 5 is supplied with hydraulic oil, the piston rod is extended, and the lock hook 11 is rotated to the unlocking position under the action of the reset tension spring 14 and the mass load of the tail support pillar actuator 1, and the lock ring 23 and the lock hook 11 are disengaged from the lock; then, the extension nozzle 18 of the tail support retracting actuator 3 is supplied with hydraulic oil, the piston rod is extended, and the tail support pillar actuator 1 is lowered; the cabin door is connected to the tail support pillar actuator 1 through the cabin door pull rod mechanism 7, and the cabin door is opened during the lowering process of the tail support pillar actuator 1; after the tail support pillar actuator 1 is lowered into place, its rodless chamber is supplied with hydraulic oil, the piston rod is extended, and the chassis 25 is extended to the bottom to play a supporting role; finally, under the joint action of the heading spring pull rod 4 and the lateral spring pull rod 2, the stability of the tail support pillar actuator 1 and the rapid return to center function during the retraction process are guaranteed; after the work is completed, First, the rod chamber of the tail support pillar actuator 1 supplies hydraulic oil, its piston rod retracts and locks, and the chassis 25 is retracted; then, the retraction nozzle 19 of the tail support retracting actuator 3 supplies hydraulic oil, the piston rod retracts, and the tail support pillar actuator 1 begins to retract; when the tail support pillar actuator 1 is retracted, the piston rod of the unlocking actuator 8 of the tail support pillar upper lock 5 is in a fully retracted position, and the locking ring 23 of the tail support pillar actuator 1 starts to move with the tail support pillar actuator 1, and hits the lock hook 11 through the locking ring 23, overcoming the reset tension spring 14 installed on the lock mechanism to make the lock hook 11 move upward, and when the lock hook 11 rotates to the locked position, the lower end of the stopping rocker arm 15 disengages from the arc surface of the lock hook, and the stopping rocker arm 15 is reset under the action of the reset tension spring 14, limiting the lock hook 11 to the locked position, and at this time, the position sensor 13 installed on the tail support pillar upper lock 5 is pressed by the switch rocker arm 10 to give a locking signal, and the locking process is completed.

[0041] Embodiment 2:

[0042] Based on the above embodiment, this embodiment further defines the specific structure of the tail support pillar upper lock 5, such as Figure 3 , Figure 4 As shown, the tail support pillar upper lock 5 includes a lock shell 16, an unlocking actuator 8 is installed on one side of the lock shell 8, and the extended end of the unlocking actuator 8 is abutted with an actuating rocker arm 9, and the actuating rocker arm 9 is installed on a spline shaft 12, and the spline shaft 12 is embedded under the lock shell 16, and a switch rocker arm 10 is installed on the other end of the spline shaft 12, and the switch rocker arm 10 is abutted with a position sensor 13 arranged on the other side of the lock shell 16, and a lock hook 11 is provided at the lower part of the shell 16, and the lock hook 11 is connected to a stopping rocker arm 15 through at least two reset tension springs 14, and the other end of the stopping rocker arm 15 is connected to the spline shaft 12. When the tail support pillar upper lock 5 is unlocked, the piston rod of the unlocking actuator 8 extends out to push the actuating rocker arm 9, and the actuating rocker arm 9 drives the stopping rocker arm 15 through the spline shaft 12 to overcome the friction and spring force to rotate it clockwise, and the stopping surface of the stopping rocker arm 15 is out of contact with the stopping surface of the lock hook 11. The lock hook 11 rotates to the unlocking position under the action of the reset tension spring 14 and the mass load of the tail support pillar actuator 1, and the lock ring 23 is disengaged from the lock hook 11; when the tail support pillar upper lock 5 is locked, the piston rod of the unlocking actuator 8 is in the fully retracted position, and the lock ring of the tail support pillar actuator 1 23 starts to move with the tail support pillar actuator 1, and the lock ring 23 hits the lock hook 11 to overcome the reset tension spring 14 installed on the lock mechanism, so that the lock hook 11 moves upward. If necessary, the lock ring 23 will be guided by the guide plate to make an adaptive movement upward. When the lock hook 11 rotates to the locked position, the lower end of the stop rocker arm 15 is separated from the arc surface of the lock hook 11. The stop rocker arm 15 is reset under the action of the reset tension spring 14, and the lock hook 11 is restricted to the locked position. At this time, the position sensor 13 installed on the upper lock 5 of the tail support pillar is pressed by the switch rocker arm 10 to give a locking signal, and the locking is completed. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0043] Embodiment 3:

[0044] Based on the above embodiment, this embodiment further defines the specific structure of the tail support pillar upper lock 5, such as Figure 3 , Figure 4 As shown, the unlocking actuator 8 is also equipped with a return spring. The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0045] Embodiment 4:

[0046] Based on the above embodiment, this embodiment further defines the specific structure of the tail support retracting and extending actuator 3, such as Figure 5As shown, radial spherical bearings 17 are provided at both ends of the tail strut retracting actuator 3, and the radial spherical bearings 17 at both ends of the tail strut retracting actuator 6 are respectively connected to the rotating rocker arm mechanism 6 and the tail strut support actuator 1, and the upper and lower parts of the tail strut retracting actuator 3 are also respectively provided with an extension nozzle 18 and a retraction nozzle 19 connected by a pipeline, and a stroke displacement sensor 20 is provided on one side of the lower part of the tail strut retracting actuator 3. First, the rod chamber of the tail support pillar actuator 1 supplies hydraulic oil, its piston rod retracts and locks, and the chassis 25 is retracted; then, the retraction nozzle 19 of the tail support retracting actuator 3 supplies hydraulic oil, the piston rod retracts, and the tail support pillar actuator 1 begins to retract; when the tail support pillar actuator 1 is retracted, the piston rod of the unlocking actuator 8 of the tail support pillar upper lock 5 is in a fully retracted position, and the locking ring 23 of the tail support pillar actuator 1 starts to move with the tail support pillar actuator 1, and hits the lock hook 11 through the locking ring 23, overcoming the reset tension spring 14 installed on the lock mechanism to make the lock hook 11 move upward, and when the lock hook 11 rotates to the locked position, the lower end of the stopping rocker arm 15 disengages from the arc surface of the lock hook, and the stopping rocker arm 15 is reset under the action of the reset tension spring 14, limiting the lock hook 11 to the locked position, and at this time, the position sensor 13 installed on the tail support pillar upper lock 5 is pressed by the switch rocker arm 10 to give a locking signal, and the locking process is completed. The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0047] Embodiment 5:

[0048] Based on the above embodiments, this embodiment further defines the specific structure of the tail support pillar actuator 1, such as Figure 6 As shown, a chassis 25 is also provided at the bottom of the tail support pillar actuator 1. The chassis 25 plays a supporting role under the action of hydraulic pressure. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0049] Embodiment 6:

[0050] Based on the above embodiment, this embodiment further defines the structure of the lateral spring pull rod 2, such as Figure 7 , Figure 8As shown, the two ends of the lateral spring pull rod 2 are provided with bearings 27, and the lateral spring pull rod 2 is connected to the second mechanical interface 26 on the tail support pillar actuator cylinder 1 through the bearings 27 at the ends. The lateral spring pull rod 2 includes an outer cylinder 30 and an inner cylinder 31 nested together in the opening direction, and the openings of the outer cylinder 30 and the inner cylinder 31 are provided with stop blocks 29 that penetrate the outer cylinder 30 and the inner cylinder 31, and a spring 28 is provided between the two stop blocks 29. The course spring pull rod 4 has the same structure as the lateral spring pull rod 2, and the course spring pull rod 4 is connected to the rotary rocker mechanism 6 through the bearings 27 at the ends. The lateral spring pull rod 2 and the course spring pull rod 4 constitute the return mechanism of the tail support retracting and releasing system, which is mainly used to support the tail support pillar actuator cylinder 1 and the rapid return function. It adopts the form of a spring tension and compression rod. When the spring pull rod is compressed, the two stop blocks 29 respectively drive the upper stop hole of the outer sleeve 30 and the stop hole under the inner sleeve 31 to move relative to each other, so that the spring 28 is compressed and a reverse load is generated. When the elastic mechanism is extended, the two stop blocks 29 respectively drive the lower stop hole of the outer sleeve 30 and the upper stop hole of the inner sleeve 31 to move relative to each other, so that the spring 28 is compressed and a reverse load is generated. The spring pull rod is elastically unloaded when the tail strut actuator cylinder 1 is in the vertical neutral position, and provides elastic force to drive the tail strut actuator cylinder 1 to return to the center when the tail strut actuator cylinder 1 is offset. When the tail strut actuator cylinder 1 is retracted, the tension of the spring 28 pulls the deflected tail strut actuator cylinder 1 back to the center position, realizing the automatic return to the center function. The other parts of this embodiment are the same as the above-mentioned embodiments and will not be repeated.

[0051] Embodiment 7:

[0052] Based on the above embodiment, this embodiment further defines the structure of the lateral spring pull rod 2, such as Fig.10 As shown, the door pull rod mechanism 7 includes a middle pull rod 33, one end of the pull rod 33 is provided with a strut end joint 34 connected to the tail strut pillar actuator 6, and the other end of the pull rod 33 is provided with a door end joint 34 connected to the tail strut door. The door pull rod mechanism 7 forms a connecting rod mechanism by connecting the tail strut pillar actuator 1 and the tail strut door. When the tail strut pillar actuator 1 is retracted and lowered, the tail strut retraction and extension actuator 3 drives the tail strut pillar actuator 1 to rotate, pushes the pull rod 33 to rotate around the hinge axis, drives the door to achieve the retraction and lowering operation, and realizes the linkage retraction and extension of the tail strut pillar actuator 1 and the door. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0053] It can be understood that the working principles and working processes of the tail support retraction and extension system structure according to an embodiment of the present invention, such as the position sensor 13 and the stroke displacement sensor 20 and other components are all prior arts and are well known to technicians in this field, and will not be described in detail here.

[0054] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A tail support retracting and extending system with a self-centering mechanism, characterized in that: The invention comprises a tail strut actuator (1) connected to an aircraft fuselage, wherein the upper portion of the tail strut actuator (1) is connected to a lateral spring pull rod (2), and the lower portion of the tail strut actuator (1) is respectively connected to a tail strut retracting actuator (3), a cabin door pull rod mechanism (7), and a tail strut upper lock (5), wherein the free end of the cabin door pull rod mechanism (7) is connected to the aircraft cabin door, the free end of the tail strut retracting actuator (3) is connected to a rotating rocker arm mechanism (6), and the other end of the rotating rocker arm mechanism (6) is connected to a heading spring pull rod (4).

2. A tail support retracting and extending system with a self-centering mechanism according to claim 1, characterized in that: The tail support pillar upper lock (5) comprises a lock housing (16), an unlocking actuator cylinder (8) is installed on one side of the lock housing (8), an end of the unlocking actuator cylinder (8) protruding from the lock housing (8) is abutted against an actuating rocker arm (9), the actuating rocker arm (9) is installed on a spline shaft (12), the spline shaft (12) is embedded under the lock housing (16), and a switch rocker arm (10) is installed on the other end of the spline shaft (12), the switch rocker arm (10) is abutted against a position sensor (13) arranged on the other side of the lock housing (16), a lock hook (11) is arranged at the lower part of the housing (16), the lock hook (11) is connected to a stop rocker arm (15) through at least two reset tension springs (14), and the other end of the stop rocker arm (15) is connected to the spline shaft (12).

3. A tail support retracting and extending system with a self-centering mechanism according to claim 2, characterized in that: The unlocking actuator (8) is also equipped with a return spring.

4. The tail support retracting and extending system with a self-centering mechanism according to claim 3, characterized in that: Both ends of the tail support retracting and extending actuator (3) are provided with radial spherical bearings (17), the radial spherical bearings (17) at both ends of the tail support retracting and extending actuator (6) are respectively connected to the rotating rocker arm mechanism (6) and the tail support pillar actuator (1), and the upper and lower parts of the tail support retracting and extending actuator (3) are also respectively provided with an extension nozzle (18) and a retraction nozzle (19) connected by a pipeline, and a stroke displacement sensor (20) is provided on one side of the lower part of the tail support retracting and extending actuator (3).

5. The tail support retracting and extending system with a self-centering mechanism according to claim 4, characterized in that: A joint bearing (21) is arranged at the top of the tail strut actuator (1), and the tail strut actuator (1) is connected to the fuselage of the aircraft through the upper joint bearing (21); a second mechanical opening (26) is arranged on the upper side of the tail strut actuator (1), and the second mechanical interface (26) on the tail strut actuator (1) is connected to the end of the lateral spring pull rod (2); the lower side of the tail strut actuator (1) is also provided with a first mechanical opening (22) connected to the radial joint bearing (17) of the tail strut retracting actuator (3), a locking ring (23) matched with the locking hook (11), and a door pull rod joint (24) connected to one end of the door pull rod mechanism (7).

6. The tail support retracting and extending system with a self-centering mechanism according to claim 5, characterized in that: A chassis (25) is also provided at the bottom of the tail support pillar actuator (1).

7. The tail support retracting and extending system with a self-centering mechanism according to claim 6, characterized in that: Both ends of the lateral spring pull rod (2) are provided with bearings (27), and the lateral spring pull rod (2) is connected to the second mechanical interface (26) on the tail support pillar actuator cylinder (1) through the bearings (27) at the ends. The lateral spring pull rod (2) includes an outer cylinder (30) and an inner cylinder (31) nested together in the opening direction, and the openings of the outer cylinder (30) and the inner cylinder (31) are provided with stop blocks (29) that penetrate the outer cylinder (30) and the inner cylinder (31), and a spring (28) is provided between the two stop blocks (29).

8. The tail support retracting and extending system with a self-centering mechanism according to claim 7, characterized in that: The course spring pull rod (4) has the same structure as the lateral spring pull rod (2), and the course spring pull rod (4) is connected to the rotary rocker mechanism (6) via a bearing (27) at the end.

9. The tail support retracting and extending system with a self-centering mechanism according to claim 8, characterized in that: The door pull rod mechanism (7) comprises a middle pull rod (33), one end of which is provided with a support end joint (34) connected to the tail support support actuator (6), and the other end of which is provided with a door end joint (34) connected to the tail support door.

Images