CN117326052A - Landing gear telescopic limiting device, telescopic limiting method and helicopter landing gear - Google Patents

Abstract

The invention discloses a landing gear telescopic limiting device, a telescopic limiting method and a helicopter landing gear, wherein in the telescopic limiting device, an outer cylinder is divided into an upper cavity and a lower cavity by an integrated baffle plate arranged in the middle, an upper floating piston is arranged in the upper cavity, the upper cavity is divided into an upper oil cavity and a lower oil cavity by the upper floating piston, the upper floating piston is in threaded connection with the bottom end of a piston rod, the top end of the piston rod extends out of the upper oil cavity, and a sealing end cover is arranged at the end part of the upper oil cavity; the lower cavity is internally provided with a lower floating piston, the lower cavity is divided into an oil storage cavity positioned at the upper part and an air cavity positioned at the lower part by the lower floating piston, and the air cavity is communicated with the outside atmosphere; an oil liquid conduction passage is arranged among the upper oil cavity, the lower oil cavity and the oil storage cavity, and an oil liquid control passage is arranged between the upper oil cavity and the lower oil cavity. The technical scheme provided by the invention solves the problems that the existing helicopter landing gear telescopic limiting device is difficult to detach, long in detachment time, easy to damage and the like.

Description

Landing gear telescopic limiting device, telescopic limiting method and helicopter landing gear

Technical Field

The invention relates to the technical field of helicopter landing gears, in particular to a landing gear telescopic limiting device, a telescopic limiting method and a helicopter landing gear.

Background

When the helicopter is on the ship, no matter the helicopter is positioned in a flight deck or a hangar, the helicopter should have complete mooring measures and matched measures so as to prevent the helicopter from moving or turning on one's side when the ship swings and rocks. The landing gear telescopic limiting device is used as an indispensable guarantee device to limit the extension or shortening of the landing gear of the helicopter, so that the helicopter is prevented from pitching or bouncing and other gesture changes in a ship surface mooring state, and the helicopter body structure and equipment safety are effectively protected. Other scenarios that may affect changes in helicopter attitude should use a landing gear extension stop to keep the amount of extension of the landing gear buffer unchanged under load.

The main structure of the existing helicopter landing gear telescopic limiting device adopts a threaded rod connection mode, the telescopic limiting device in the structural mode is easy to generate a thread locking phenomenon when the landing gear receives higher tensile or compressive load, and the problem of the thread locking phenomenon greatly influences the lifting efficiency and the task efficiency of the helicopter because the tensile load or the compressive load is difficult to judge, so that the helicopter ground crew is long in general use and difficult to detach when the telescopic limiting device is detached.

Disclosure of Invention

The purpose of the invention is that: in order to solve the problems, the embodiment of the invention provides a landing gear telescopic limiting device, a telescopic limiting method and a helicopter landing gear, which are used for solving the problems that the existing helicopter landing gear telescopic limiting device is difficult to disassemble, long in disassembly time, easy to damage and the like because a threaded rod connection form of the existing helicopter landing gear telescopic limiting device is subjected to high load and the load type is difficult to judge.

The technical scheme of the invention is as follows: the embodiment of the invention provides a landing gear telescopic limiting device, which comprises: the device comprises an outer cylinder 1, a piston rod 2, an upper floating piston 5, a lower floating piston 6 and a sealing end cover 7;

the outer cylinder 1 is divided into an upper cavity and a lower cavity by an integrated partition plate arranged in the middle, an upper floating piston 5 is arranged in the upper cavity, the upper cavity is divided into an upper oil cavity 14 and a lower oil cavity 15 by the upper floating piston 5, the upper floating piston 5 is in threaded connection with the bottom end of the piston rod 2, the top end of the piston rod 2 extends out of the upper oil cavity 14, and a sealing end cover 7 is arranged at the end part of the upper oil cavity 14; a lower floating piston 6 is arranged in the lower cavity, the lower cavity is divided into an oil storage cavity 16 positioned at the upper part and an air cavity positioned at the lower part by the lower floating piston 6, and the air cavity is communicated with the outside atmosphere;

an oil liquid conduction passage is arranged among the upper oil cavity 14, the lower oil cavity 15 and the oil storage cavity 16, and an oil liquid control passage is arranged between the upper oil cavity 14 and the lower oil cavity 15.

Alternatively, in the landing gear extension stop as described above,

the landing gear telescopic limiting device is used for controlling the oil flowing direction between the upper oil cavity 14 and the lower oil cavity 15 through the oil control passage so as to drive the upper floating piston 5 to move downwards or upwards, thereby controlling the length of the landing gear telescopic limiting device; and is further used for storing the overflow oil in the lower oil cavity 15 or supplementing the oil in the lower oil cavity 15 by the oil storage cavity 16 in the process of moving the upper floating piston 5 downwards or upwards through the oil conducting passage.

Alternatively, in the landing gear extension stop as described above,

the oil control passage includes: the first valve 9 is arranged at the upper part of the upper oil cavity 14, the second valve 10 is arranged at the lower oil cavity 15 and is used for communicating an oil pipeline of the first valve 9 and the second valve 10, the rotary hand pump 8 is arranged in the oil pipeline, and the oil flowing direction between the upper oil cavity 14 and the lower oil cavity 15 is controlled through the forward rotation and the reverse rotation of the rotary hand pump 8.

Optionally, in the landing gear telescopic limiting device as described above, the rotary hand pump 8 is configured as an eccentric rotation shaft structure, and includes: a hand pump housing 18, a hand pump end cap 19, a rotary handle 20, a rotor 21 and vanes 22;

the hand pump housing 18 is set to be a sleeve structure with one end open, and is provided with an eccentric cavity, the opening is sealed through the hand pump end cover 19, a limit groove is formed in the middle of the rotor 21, two blades 22 are installed in the limit groove of the rotor 21, the rotor 21 and the installation structure of the two blades 22 are integrally arranged in the eccentric cavity, the eccentric cavity is isolated into a cavity communicated with the upper oil cavity 14 and a cavity communicated with the lower oil cavity 15 through the two blades 22, a rotating shaft of the rotor 21 is connected with the rotating handle 20, and the rotating handle 20 drives the rotor 21 to rotate in the eccentric cavity.

Alternatively, in the landing gear extension stop as described above,

the rotary hand pump 8 is used for driving the rotor 21 and the blades 22 to synchronously rotate in the eccentric cavity through the rotation of the rotary handle 20, and controlling the oil flow direction between the upper oil cavity 14 and the lower oil cavity 15.

Alternatively, in the landing gear extension stop as described above,

the rotating shaft of the rotor 21 is positioned at the eccentric position of the eccentric cavity and is in a concentric structure with the outer wall of the hand pump housing 18;

spring mounting holes are formed in two ends of the two blades 22, which are oppositely arranged, springs are mounted in the spring mounting holes on two sides of the corresponding positions, so that the two blades 22 are pushed onto the inner wall of the eccentric cavity through the springs, the blades 22 are in close contact with the inner wall of the eccentric cavity, and oil is sucked and pushed out.

Alternatively, in the landing gear extension stop as described above,

the oil liquid conduction path comprises: the third valve 11 is arranged at the upper part of the upper oil cavity 14, the fourth valve 12 is arranged at the lower part of the lower oil cavity 15, the fifth valve 13 is arranged in the oil storage cavity 16, and an oil liquid pipeline for communicating the third valve 11, the fourth valve 12 and the fifth valve 13.

The embodiment of the invention provides a telescopic limiting method of a landing gear telescopic limiting device, which is implemented by adopting the landing gear telescopic limiting device, and comprises the following steps: an extension adjustment control mode and a shortening adjustment control mode;

wherein, the elongation adjustment control mode includes: by controlling the opening and closing of the valves and the rotation direction of the rotating handle 20, oil enters the lower oil cavity 15 from the upper oil cavity 14, and pushes the upper floating piston 5 and the piston rod 2 to extend, so that the landing gear expansion limiting device is subjected to expansion adjustment; in the elongation adjustment process, the lower oil cavity 15 is supplemented with oil through the 16 oil storage cavity 16;

the shortening adjustment control method comprises the following steps: by controlling the opening and closing of the valves and the rotation direction of the rotating handle 20, oil enters the upper oil cavity 14 from the lower oil cavity 15, and pushes the upper floating piston 5 and the piston rod 2 to retract, so that the landing gear telescopic limiting device is shortened and adjusted; during the shortened adjustment process, excess oil enters the oil reservoir 16 from the upper oil chamber 14.

Optionally, in the telescopic limiting method of the landing gear telescopic limiting device, the telescopic limiting method further includes: a length lock control mode and a length unlock control mode;

wherein, length locking control mode includes: controlling all valves to be kept closed, wherein the oil liquid in each oil cavity cannot flow and cannot be compressed, so that the length of the telescopic limiting device is locked, and the telescopic limiting device cannot be compressed and cannot be stretched;

the length unlocking control mode comprises the following steps: firstly, the third valve 11 is controlled to be opened, and the fourth valve 12 is controlled to be opened, so that the upper oil cavity 14 is communicated with the lower oil cavity 15; and then the fifth valve 13 is controlled to be opened, so that the upper oil cavity 14 and the lower oil cavity 15 are simultaneously communicated with the oil storage cavity 16, and the oil storage cavity 16 is communicated with the outside atmosphere through the vent hole 17.

The embodiment of the invention also provides a helicopter landing gear, which is characterized by comprising: landing gear, upper joint 3, lower joint 4, landing gear expansion and contraction limiting apparatus as claimed in any one of the preceding claims;

the piston rod 2 of the landing gear telescopic limiting device is in threaded connection with the upper joint 3, and the upper joint 3 is fixedly connected with an upper position interface of the landing gear; the outer cylinder 1 of the landing gear telescopic limiting device is in threaded connection with the lower joint 4, the lower joint 4 is fixedly connected with a landing gear lower part interface, and the lower joint 4 is provided with a vent hole 17 for communicating the air cavity with the outside atmosphere;

the landing gear telescopic limiting device is used for carrying out extension adjustment control, shortening adjustment control, length locking control and length unlocking control on the landing gear connected with the landing gear telescopic limiting device.

The invention has the beneficial effects that:

the embodiment of the invention provides a landing gear telescopic limiting device, a telescopic limiting method and a helicopter landing gear, wherein the length adjustment of the telescopic limiting device is realized in an oil control mode; the oil flow direction is bidirectionally regulated by adopting an integrated rotary hand pump; the oil storage cavity is designed to store or supplement oil to the upper and lower oil cavities; the air cavity is designed to be communicated with the outside atmosphere; the locking length of the telescopic limiting device is controlled by designing an independent valve, so that the valve is incompressible and inextensible. The telescopic limiting device provided by the embodiment of the invention can limit the length of the buffer of the undercarriage of the helicopter, so that the buffer is incompressible and inextensible, the length of the telescopic limiting device can be conveniently and bidirectionally adjusted without additionally providing a special spanner, and the telescopic limiting device can be rapidly disassembled after being loaded.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate and do not limit the invention.

Fig. 1 is a schematic view of an external structure of a landing gear expansion limiting device according to an embodiment of the present invention; fig. 1 b is a front view, a is a left view, and c is a right view;

FIG. 2 is a schematic cross-sectional view of the landing gear extension stop provided by the embodiment of FIG. 1;

fig. 3 is a partially enlarged schematic illustration of a rotary hand pump in a landing gear telescopic limiting device according to an embodiment of the present invention;

FIG. 4 is a schematic view of the mounting structure of the internal rotor and blades of the rotary hand pump provided by the embodiment of FIG. 3;

FIG. 5 is a schematic view of the internal vanes of the rotary hand pump provided by the embodiment of FIG. 3;

FIG. 6 is a schematic illustration of the rotary hand pump provided by the embodiment of FIG. 3 with the rotor rotated to different positions; the rotor and the blades are illustrated in a diagram in fig. 6, only the rotor is illustrated in b diagrams to e diagrams, the b diagram is the horizontal position of the rotor, the c diagram is the three-dimensional diagram of the b diagram, the d diagram is the vertical position of the rotor, and the e diagram is the three-dimensional diagram of the d diagram.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The prior art has already described that, because its main structure adopts the threaded rod connection form, can take place the thread lock phenomenon when receiving higher load, and be difficult to judge the load type, therefore, helicopter ground crew is long and be difficult to dismantle when dismantling flexible stop device generally, still causes the damage to flexible stop device easily, and above-mentioned problem influences helicopter efficiency and mission efficiency greatly.

According to the landing gear telescopic limiting device, the telescopic limiting method and the helicopter landing gear, the length of the telescopic limiting device is controlled by oil, the load of the telescopic limiting device can be rapidly unloaded during disassembly, the problem of thread locking is avoided, and accordingly maintenance operation time of ground staff is greatly shortened.

The following specific embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.

Fig. 1 is a schematic view of an external structure of a landing gear expansion limiting device according to an embodiment of the present invention; fig. 1 b is a front view, a is a left view, and c is a right view; fig. 2 is a schematic cross-sectional view of the landing gear extension stop provided by the embodiment of fig. 1. Referring to fig. 1 and 2, the components of the landing gear expansion limiting device provided by the embodiment of the invention include: the piston rod comprises an outer cylinder 1, a piston rod 2, an upper floating piston 5, a lower floating piston 6 and a sealing end cover 7.

As shown in fig. 2, the inner structure of the landing gear telescopic limiting device is illustrated, an outer cylinder 1 is divided into an upper cavity and a lower cavity by an integrated partition plate arranged in the middle, an upper floating piston 5 is arranged in the upper cavity, the upper cavity is divided into an upper oil cavity 14 and a lower oil cavity 15 by the upper floating piston 5, the upper floating piston 5 is in threaded connection with the bottom end of a piston rod 2, the top end of the piston rod 2 extends out of the upper oil cavity 14, and a sealing end cover 7 is arranged at the end part of the upper oil cavity 14; a lower floating piston 6 is arranged in the lower cavity, the lower cavity is divided into an oil storage cavity 16 positioned at the upper part and an air cavity positioned at the lower part by the lower floating piston 6, and the air cavity is communicated with the outside atmosphere.

As shown in fig. 2, in the landing gear telescopic limiting device provided by the embodiment of the invention, an oil liquid conducting passage, such as an oil way on the left side of the outer cylinder 1 in fig. 2, is arranged among the upper oil cavity 14, the lower oil cavity 15 and the oil storage cavity 16; in addition, an oil control passage, such as an oil passage on the right side of the outer cylinder 1 in fig. 2, is provided between the upper oil chamber 14 and the lower oil chamber 15.

Based on the structural form of the landing gear telescopic limiting device provided by the embodiment of the invention, the working principle of the landing gear telescopic limiting device is as follows:

on the one hand, the oil flow direction between the upper oil cavity 14 and the lower oil cavity 15 is controlled through the oil control passage so as to drive the upper floating piston 5 to move downwards or upwards, and therefore the length of the landing gear expansion limiting device is controlled.

On the other hand, in the course of downward or upward movement of the upper floating piston 5 through the oil passage, the lower oil chamber 15 is stored by the oil storage chamber 16 to overflow oil or to supplement oil to the lower oil chamber 15.

In one implementation manner of the embodiment of the present invention, as shown in fig. 2, the oil control path includes: the first valve 9 is arranged at the upper part of the upper oil cavity 14, the second valve 10 is arranged at the lower part of the lower oil cavity 15, an oil liquid pipeline used for communicating the first valve 9 and the second valve 10 is arranged in the oil liquid pipeline, and the rotary hand pump 8 is arranged in the oil liquid pipeline.

In this embodiment, the direction of oil flow between the upper oil chamber 14 and the lower oil chamber 15 is controlled by the forward and reverse rotation of the rotary hand pump 8.

Fig. 3 is a schematic view of a part of a rotary hand pump in a landing gear telescopic limiting device according to an embodiment of the present invention, fig. 4 is a schematic view of an installation structure of an internal rotor and a vane of the rotary hand pump according to the embodiment shown in fig. 3, and fig. 5 is a schematic view of an internal vane of the rotary hand pump according to the embodiment shown in fig. 3. As shown in fig. 3 to 5, in a specific implementation of the embodiment of the present invention, the rotary hand pump 8 is provided in an eccentric rotation shaft structure, including: a hand pump housing 18, a hand pump end cap 19, a rotary handle 20, a rotor 21 and vanes 22.

Referring to fig. 3 to 5, the hand pump housing 18 is configured as a sleeve structure with one end open, having an eccentric cavity, the opening is sealed by the hand pump end cap 19, a limit groove is provided in the middle of the rotor 21, two blades 22 are installed in the limit groove of the rotor 21, the rotor 21 and the installation structure of the two blades 22 are integrally disposed in the eccentric cavity, the eccentric cavity is separated into a cavity communicated with the upper oil cavity 14 and a cavity communicated with the lower oil cavity 15 by the two blades 22, the rotating shaft of the rotor 21 is connected with the rotating handle 20, and the rotating handle 20 drives the rotor 21 to rotate in the eccentric cavity. Fig. 6 is a schematic diagram of the rotary hand pump according to the embodiment shown in fig. 3, in which the rotor and the blades are shown in fig. 6, in which only the rotor is shown in fig. a, b to e, in which the rotor is shown in horizontal position, c is a three-dimensional view of the b, d is a vertical position, and e is a three-dimensional view of the d.

As shown in fig. 4 and 6, the rotation shaft of the rotor 21 is located at the eccentric position of the eccentric cavity and is concentric with the outer wall of the hand pump housing 18; spring mounting holes are formed in two ends of the two blades 22, which are oppositely arranged, springs are mounted in the spring mounting holes on two sides of the corresponding positions, so that the two blades 22 are pushed onto the inner wall of the eccentric cavity through the springs, the blades 22 are in close contact with the inner wall of the eccentric cavity, and oil is sucked and pushed out.

In one implementation of the embodiment of the present invention, as shown in fig. 2, the oil conducting path includes: the third valve 11 is arranged at the upper part of the upper oil cavity 14, the fourth valve 12 is arranged at the lower part of the lower oil cavity 15, the fifth valve 13 is arranged in the oil storage cavity 16, and an oil liquid pipeline for communicating the third valve 11, the fourth valve 12 and the fifth valve 13.

In the embodiment of the invention, the opening and closing states of the valves and the rotation direction of the rotary handle 20 are controlled, so that the oil flow direction between the upper oil cavity 14 and the lower oil cavity 15 can be controlled, and the upper floating piston 5 is driven to move downwards or upwards, so that the length of the landing gear expansion limiting device is controlled; the length locking function of the telescopic limiting device can be realized, and the length unlocking function of the telescopic limiting device can be realized by controlling the opening sequence of the valve, and the realization mode of each function is specifically described in the following embodiment.

The landing gear telescopic limiting device provided by the embodiment of the invention adopts an oil liquid control mode to realize the length adjustment of the telescopic limiting device; the oil flow direction is bidirectionally regulated by adopting an integrated rotary hand pump; the oil storage cavity is designed to store or supplement oil to the upper and lower oil cavities; the air cavity is designed to be communicated with the outside atmosphere; the locking length of the telescopic limiting device is controlled by designing an independent valve, so that the valve is incompressible and inextensible. The telescopic limiting device provided by the embodiment of the invention can limit the length of the buffer of the undercarriage of the helicopter, so that the buffer is incompressible and inextensible, the length of the telescopic limiting device can be conveniently and bidirectionally adjusted without additionally providing a special spanner, and the telescopic limiting device can be rapidly disassembled after being loaded.

Based on the landing gear telescopic limiting device provided by the embodiment of the present invention, the embodiment of the present invention further provides a telescopic limiting method implemented by using the landing gear telescopic limiting device provided by any one of the embodiments, which specifically includes:

1, an elongation adjustment control mode, wherein oil enters a lower oil cavity 15 from an upper oil cavity 14 by controlling the opening and closing of each valve and the rotation direction of a rotating handle 20, and pushes an upper floating piston 5 and a piston rod 2 to perform extension movement, so that an undercarriage expansion limiting device performs elongation adjustment; in the elongation adjustment process, the lower oil chamber 15 is supplemented with oil through the 16 oil storage chamber 16.

2, shortening the adjusting control mode, namely controlling the opening and closing of each valve and the rotating direction of the rotating handle 20 to enable oil to enter the upper oil cavity 14 from the lower oil cavity 15, pushing the upper floating piston 5 and the piston rod 2 to retract, so that the landing gear telescopic limiting device is shortened and adjusted; during the shortened adjustment process, excess oil enters the oil reservoir 16 from the upper oil chamber 14.

And 3, controlling all valves to be kept closed in a length locking control mode, wherein the oil liquid in each oil cavity cannot flow and cannot be compressed, so that the length of the telescopic limiting device is locked, and the telescopic limiting device cannot be compressed and cannot be stretched.

4, a length unlocking control mode, firstly, controlling the third valve 11 to be opened and controlling the fourth valve 12 to be opened so that the upper oil cavity 14 is communicated with the lower oil cavity 15; and then the fifth valve 13 is controlled to be opened, so that the upper oil cavity 14 and the lower oil cavity 15 are simultaneously communicated with the oil storage cavity 16, and the oil storage cavity 16 is communicated with the outside atmosphere through the vent hole 17.

Based on the landing gear telescopic limiting device and the telescopic limiting method provided by the embodiment of the invention, the embodiment of the invention also provides a helicopter landing gear, which comprises: landing gear, upper joint 3, lower joint 4, and landing gear expansion and contraction limiting apparatus as provided in any of the embodiments described above.

The piston rod 2 of the landing gear telescopic limiting device is in threaded connection with the upper joint 3, and the upper joint 3 is fixedly connected with an upper part interface of the landing gear; the outer cylinder 1 of the landing gear telescopic limiting device is in threaded connection with the lower joint 4, the lower joint 4 is fixedly connected with a landing gear lower part interface, and the lower joint 4 is provided with a vent hole 17 for communicating the air cavity with the outside atmosphere;

the landing gear telescopic limiting device is used for carrying out extension adjustment control, shortening adjustment control, length locking control and length unlocking control on the landing gear connected with the landing gear telescopic limiting device.

Specific control forms of the extension adjustment control, the shortening adjustment control, the length lock control, and the length unlock control have been specifically described in the above embodiments, and thus are not described here again.

The following describes schematically, by means of a specific embodiment, implementation manners of a landing gear expansion limiting device and an expansion limiting method thereof according to an embodiment of the present invention.

Example 1

The embodiment provides a landing gear telescopic limiting device for an easy-to-detach helicopter. The length of the telescopic limiting device is controlled through oil, so that the functions of stretching and adjusting, shortening and adjusting, locking and unlocking can be realized.

The landing gear telescopic limiting device provided by the embodiment comprises the following components: the device comprises an outer cylinder 1, a piston rod 2, an upper joint 3, a lower joint 4, an upper floating piston 5, a lower floating piston 6, a sealing end cover 7, a rotary hand pump 8, a first valve 9, a second valve 10, a third valve 11, a fourth valve 12, a fifth valve 13, an upper oil cavity 14, a lower oil cavity 15, an oil storage cavity 16 and a vent hole 17; the rotary hand pump 8 is composed of a hand pump housing 18, a hand pump end cover 19, a rotary handle 20, a rotor 21 and blades 22.

In the landing gear telescopic limiting device provided by the embodiment, the upper joint 3 is connected with the piston rod 2 through a threaded structure, and the upper joint 3 can be fixedly connected with a landing gear upper position interface; the lower joint 4 is connected with the bottom end of the outer cylinder 1 through a thread structure, the lower joint 4 can be fixedly connected with a landing gear lower part interface, and the lower joint 4 is provided with a vent hole 17, so that the connection between a cavity below the lower floating piston 6 and the outside atmosphere can be realized, and the acting force on the lower floating piston 6 is prevented from being formed inside the cavity; the lower end of the piston rod 2 is connected with the upper floating piston 5 through threads; an integrated baffle plate is designed in the middle of the outer cylinder 1 to separate the lower oil cavity 15 from the oil storage cavity 16, the upper end of the outer cylinder 1 is sealed through a sealing end cover 7, sealing ring grooves are respectively designed on the outer side and the inner side of the sealing end cover 7, a sealing ring and a gasket can be installed, and the upper oil cavity 14 can be isolated from the outside atmosphere; the upper floating piston 5 is also provided with a sealing ring groove, a sealing ring and a gasket can be installed, and the upper oil cavity 14 and the lower oil cavity 15 can be isolated.

In the landing gear telescopic limiting device provided by the embodiment, the first valve 9 and the third valve 11 are arranged in the oil cavity 14 on the landing gear telescopic limiting device; the lower oil cavity 15 is provided with a second valve 10 and a fourth valve 12 which are two valves in total; the oil storage chamber 16 is provided with a fifth valve 13, which is common to all valves. Wherein the third valve 11, the fourth valve 12 and the fifth valve 13 are directly connected through connecting pipelines; the first valve 9 and the second valve 10 are connected through a connecting pipeline, and a rotary hand pump 8 is arranged in the middle of the pipeline.

In the landing gear telescopic limiting device provided by the embodiment, the upper oil cavity 14, the lower oil cavity 15 and the oil storage cavity 16 are respectively filled with hydraulic oil, the rotating hand pump 8 is used for controlling the oil flowing direction, and the oil pushes the upper floating piston 5 to move up and down, so that the volumes of the upper oil cavity 14 and the lower oil cavity 15 are changed, and the telescopic limiting device can be lengthened or shortened.

In addition, the oil storage cavity 16 can store overflow oil in the lower oil cavity 15 or supplement oil in the lower oil cavity 15. It should be noted that, since the piston rod 2 is provided in the upper oil chamber 14, that is, the sectional area of the upper oil chamber 14 is smaller than the sectional area of the lower oil chamber 15. Therefore, in one case, when the upper floating piston 5 moves downward, the volume of the upper oil chamber 14 is increased to be smaller than that of the lower oil chamber 15, that is, the lower oil chamber 15 needs to be stored through the oil storage chamber 16 to overflow oil; in another case, when the floating piston moves upwards on the 5-way piston, the volume of the upper oil cavity 14 is reduced to be smaller than that of the lower oil cavity 15, namely, the lower oil cavity 15 needs to be supplemented with oil through the oil storage cavity 16.

In the landing gear telescopic limiting device provided by the embodiment, the rotary hand pump 8 adopts an eccentric rotating shaft structure, the pump cavity is provided with two paths of oil liquid inlets and outlets from top to bottom, the rotating shaft of the rotor 21 is positioned at the eccentric position of the pump cavity, a limiting groove is designed in the middle of the rotor 21, two blades 22 are limited in the limiting groove of the rotor 21, two springs at two opposite ends of the blades 22 are mutually connected, and the blades 22 are guaranteed to be in close contact with the wall of the pump body cavity, so that oil liquid is sucked and pushed out. The rotary handle 20 can rotate in both directions, rotating oil clockwise from below to the upper pipeline, and rotating oil counterclockwise from above to the lower pipeline.

The landing gear telescopic limiting device provided by the embodiment performs the following functions:

1, elongation adjusting function: the third valve 11 is controlled to be closed, the fourth valve 12 is controlled to be opened, the third valve 11 is controlled to be opened, the first valve 9 is controlled to be opened, the second valve 10 is controlled to be opened, the rotating handle 20 is controlled to rotate anticlockwise, so that oil enters the lower oil cavity 15 from the upper oil cavity 14, the upper floating piston 5 and the piston rod 2 are pushed to perform extension movement, and the landing gear extension limiting device is enabled to perform extension adjustment; and the oil in the lower oil cavity 15 is supplemented by the 16 oil storage cavity 16, and all valves are closed after the lower oil cavity is adjusted to be in place.

2, shortening the regulating function: the third valve 11 is controlled to be opened, the second valve 10 is controlled to be closed, the fifth valve 13 is controlled to be opened, the first valve 9 is controlled to be opened, the second valve 10 is controlled to be opened, the rotating handle 20 is controlled to rotate clockwise, so that oil enters the upper oil cavity 14 from the lower oil cavity 15, the upper floating piston 5 and the piston rod 2 are pushed to perform retracting movement, and the landing gear telescopic limiting device is shortened and adjusted; in addition, excess oil enters the reservoir 16 from the upper chamber 14 and after being adjusted in place, all valves are closed.

3, length locking function: all valves are controlled to be kept closed, oil in the oil cavity cannot flow and cannot be compressed, and therefore the length of the telescopic limiting device is locked, and the telescopic limiting device cannot be compressed and cannot be stretched.

4, length unlocking function: firstly, the third valve 11 is controlled to be opened, the fourth valve 12 is controlled to be opened, and at the moment, the upper oil cavity 14 is communicated with the lower oil cavity 15, so that part of internal stress tensile load or compression load can be released first; after the third valve 11 and the fourth valve 12 are opened, the fifth valve 13 is controlled to be opened, at this time, the upper oil cavity 14 and the lower oil cavity 15 are simultaneously communicated with the oil storage cavity 16, and the oil storage cavity 16 is communicated with the outside atmosphere through the vent hole 17. At this time, the internal stress of the whole telescopic limiting device is completely released, the tensile load or the compressive load along the axial load is zero, and the telescopic limiting effect is invalid, so that the telescopic limiting device is rapidly disassembled after being loaded.

It should be noted that, in the length unlocking function, if the third valve 11 is controlled to be communicated with the fifth valve 13 or the fourth valve 12 is controlled to be communicated with the fifth valve 13, the whole telescopic limiting device will directly lose the elongation limiting function, at this time, the internal stress of the landing gear will be completely released under the loaded condition, and the landing gear posture may be suddenly changed, so that the aircraft is pitching. It is necessary to gradually relieve the internal stress to alleviate the possible abrupt change in posture.

Although the embodiments of the present invention are described above, the present invention is not limited to the embodiments which are used for understanding the present invention. Any person skilled in the art can make any modification and variation in form and detail without departing from the spirit and scope of the present disclosure, but the scope of the present disclosure is to be determined by the appended claims.

Claims (10)

1. Landing gear flexible stop device, characterized by includes: the device comprises an outer cylinder (1), a piston rod (2), an upper floating piston (5), a lower floating piston (6) and a sealing end cover (7);

the outer cylinder (1) is divided into an upper cavity and a lower cavity by an integrated partition plate arranged in the middle, an upper floating piston (5) is arranged in the upper cavity, the upper cavity is divided into an upper oil cavity (14) and a lower oil cavity (15) by the upper floating piston (5), the upper floating piston (5) is in threaded connection with the bottom end of the piston rod (2), the top end of the piston rod (2) extends out of the upper oil cavity (14), and a sealing end cover (7) is arranged at the end part of the upper oil cavity (14); a lower floating piston (6) is arranged in the lower cavity, the lower cavity is divided into an oil storage cavity (16) at the upper part and an air cavity at the lower part by the lower floating piston (6), and the air cavity is communicated with the outside atmosphere;

an oil liquid conduction passage is arranged among the upper oil cavity (14), the lower oil cavity (15) and the oil storage cavity (16), and an oil liquid control passage is arranged between the upper oil cavity (14) and the lower oil cavity (15).

2. The landing gear extension stop of claim 1, wherein,

the landing gear telescopic limiting device is used for controlling the oil flowing direction between the upper oil cavity (14) and the lower oil cavity (15) through the oil control passage so as to drive the upper floating piston (5) to move downwards or upwards, thereby controlling the length of the landing gear telescopic limiting device; and the device is also used for storing the overflow oil of the lower oil cavity (15) or supplementing the oil of the lower oil cavity (15) by the oil storage cavity (16) in the process of downwards or upwards moving the upper floating piston (5) through the oil conducting passage.

3. The landing gear extension stop of claim 1, wherein,

the oil control passage includes: the first valve (9) is arranged at the upper part of the upper oil cavity (14), the second valve (10) is arranged at the lower oil cavity (15) and is used for communicating the first valve (9) and an oil pipeline of the second valve (10), the rotary hand pump (8) is arranged in the oil pipeline, and the oil flowing direction between the upper oil cavity (14) and the lower oil cavity (15) is controlled by forward and reverse rotation of the rotary hand pump (8).

4. A landing gear extension stop according to claim 3, wherein the rotary hand pump (8) is arranged as an eccentric shaft structure comprising: a hand pump housing (18), a hand pump end cover (19), a rotary handle (20), a rotor (21) and blades (22);

wherein, hand pump housing (18) set up to one end open-ended sleeve structure, have eccentric cavity, the opening part is sealed through hand pump end cover (19), rotor (21) middle part is provided with the spacing groove, two blade (22) are installed in the spacing groove of rotor (21), in eccentric cavity is wholly arranged in to the mounting structure of rotor (21) and two blade (22), keep apart eccentric cavity into the cavity that communicates with last oil pocket (14) and the cavity that communicates with lower oil pocket (15) through two blade (22), rotor (21) pivot is connected with twist grip (20), rotate in eccentric cavity through twist grip (20) drive rotor (21).

5. The landing gear extension stop as defined in claim 4, wherein,

the rotary hand pump (8) is used for driving the rotor (21) and the blades (22) to synchronously rotate in the eccentric cavity through the rotation of the rotary handle (20) so as to control the oil flow direction between the upper oil cavity (14) and the lower oil cavity (15).

6. The landing gear extension stop of claim 5, wherein,

the rotating shaft of the rotor (21) is positioned at the eccentric position of the eccentric cavity and is in a concentric structure with the outer wall of the hand pump housing (18);

spring mounting holes are formed in two ends, opposite to each other, of the two blades (22), springs are mounted in the spring mounting holes on two sides of the corresponding positions, so that the two blades (22) are pushed onto the inner wall of the eccentric cavity through the springs, the blades (22) are in close contact with the inner wall of the eccentric cavity, and oil is sucked and pushed out.

7. Landing gear extension stop according to any one of claims 1 to 6, wherein,

the oil liquid conduction path comprises: the oil storage device comprises a third valve (11) arranged at the upper part of an upper oil cavity (14), a fourth valve (12) arranged at the lower part of a lower oil cavity (15), a fifth valve (13) arranged in an oil storage cavity (16), and an oil pipeline for communicating the third valve (11), the fourth valve (12) and the fifth valve (13).

8. A telescopic limiting method of a landing gear telescopic limiting device, characterized in that the telescopic limiting method is performed by using the landing gear telescopic limiting device according to any one of claims 1 to 7, comprising: an extension adjustment control mode and a shortening adjustment control mode;

wherein, the elongation adjustment control mode includes: the oil enters the lower oil cavity (15) from the upper oil cavity (14) of the valve (14) by controlling the opening and closing of each valve and the rotating direction of the rotating handle (20), and pushes the upper floating piston (5) and the piston rod (2) to extend, so that the landing gear expansion limiting device is subjected to expansion adjustment; in the elongation adjustment process, the oil in the lower oil cavity (15) is supplemented through the oil storage cavity (16) of the lower oil cavity (16);

the shortening adjustment control method comprises the following steps: the oil enters the upper oil cavity (14) from the lower oil cavity (15) by controlling the opening and closing of each valve and the rotating direction of the rotating handle (20), and pushes the upper floating piston (5) and the piston rod (2) to retract, so that the landing gear telescopic limiting device is shortened and adjusted; in the shortening and adjusting process, redundant oil enters the oil storage cavity (16) from the upper oil cavity (14).

9. The landing gear expansion and contraction limiting apparatus according to claim 8, further comprising: a length lock control mode and a length unlock control mode;

wherein, length locking control mode includes: controlling all valves to be kept closed, wherein the oil liquid in each oil cavity cannot flow and cannot be compressed, so that the length of the telescopic limiting device is locked, and the telescopic limiting device cannot be compressed and cannot be stretched;

the length unlocking control mode comprises the following steps: firstly, controlling the third valve (11) to be opened and controlling the fourth valve (12) to be opened so that the upper oil cavity (14) is communicated with the lower oil cavity (15); and then the fifth valve (13) is controlled to be opened, so that the upper oil cavity (14) and the lower oil cavity (15) are simultaneously communicated with the oil storage cavity (16), and the oil storage cavity (16) is communicated with the external atmosphere through the vent hole (17).

10. A helicopter landing gear comprising: landing gear, upper joint (3), lower joint (4), and landing gear expansion and contraction limiting apparatus according to any one of claims 1 to 7;

the piston rod (2) of the landing gear telescopic limiting device is in threaded connection with the upper joint (3), and the upper joint (3) is fixedly connected with the landing gear upper position interface; the outer cylinder (1) of the landing gear telescopic limiting device is in threaded connection with the lower joint (4), the lower joint (4) is fixedly connected with a landing gear lower part interface, and the lower joint (4) is provided with a vent hole (17) for communicating the air cavity with the outside atmosphere;

the landing gear telescopic limiting device is used for carrying out extension adjustment control, shortening adjustment control, length locking control and length unlocking control on the landing gear connected with the landing gear telescopic limiting device.