Double-actuator-cylinder folding and unfolding system for folding and unfolding undercarriage and folding and unfolding method

Abstract

The invention relates to the technical field of undercarriages, and discloses a double-actuator-cylinder retracting and releasing system and method for retracting and releasing an undercarriage, the double-actuator-cylinder retracting and releasing system comprises a driving cylinder, a follow-up cylinder and a control assembly, the control assembly comprises a guide pipe assembly and a one-way valve body, and the follow-up cylinder is provided with a follow-up cylinder extending lock assembly; the preset unlocking oil pressure A of the one-way valve body is larger than the preset unlocking oil pressure B of the follow-up cylinder extending lock assembly. The follow-up cylinder II is arranged to assist the driving cylinder I to stretch out and draw back, the supporting strength is improved, and occupied space is reduced; by arranging the one-way valve body 4, oil path crosslinking between the driving cylinder I and the follow-up cylinder II can be achieved, so that the unlocking sequence of the driving cylinder I and the follow-up cylinder II can be controlled, the situation that the extending sequence of the driving cylinder I and the follow-up cylinder II is disordered is avoided, the control difficulty is lowered, and the fault rate of the hydraulic control system is lowered.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft landing gear, in particular to a double-actuating cylinder retracting and extending system and a retracting and extending method for retracting and extending a landing gear. Background Art

[0002] The aircraft landing gear is mainly controlled by the extension and retraction of the hydraulic cylinder during the retraction and extension process. In order to improve the stability during retraction and extension, the ordinary cylinder is improved. For example, the cylinder with a hydraulic floating snap ring lock disclosed in the announcement number CN104500501B is often high in the design process of the aircraft landing gear. It is difficult to meet the space requirements of the aircraft landing gear retraction and extension cylinder by a single large-diameter cylinder in a small aircraft space. However, by setting two independent small-diameter cylinders, a high-precision pressure supply system is required to achieve synchronous extension and retraction. If there is an extension and retraction locking device in the cylinder, the unlocking sequence of the extension and retraction locking device needs to be controlled. This will not only increase the difficulty of the aircraft hydraulic system design, but also increase the failure rate of the hydraulic control, and reduce the safety of the aircraft landing gear retraction and extension. Therefore, the existing cylinder system for retracting and extending the aircraft landing gear cannot meet the function of safe retraction and extension of the landing gear under the extension and retraction of the double cylinders. Summary of the invention

[0003] The purpose of the present invention is to provide a double actuator retraction and extension system and method for retracting and extending a landing gear, so as to solve the problem that the existing actuator system for retracting and extending an aircraft landing gear cannot meet the function of safely retracting and extending the landing gear under the extension and retraction of the double actuator.

[0004] The present invention is achieved through the following technical scheme: a double-actuator retraction and extension system for landing gear retraction, including an active cylinder, wherein the active cylinder includes an active cylinder end cover assembly, an active cylinder outer cylinder assembly, an active cylinder piston rod assembly, and an active cylinder earring bolt assembly, wherein the active cylinder end cover assembly, the active cylinder outer cylinder assembly, and the active cylinder piston rod assembly cooperate to form an extension and retraction locking assembly; an extension oil inlet is provided on the active cylinder end cover assembly; and a retraction oil inlet is provided on the active cylinder outer cylinder assembly.

[0005] A control component, the control component includes a conduit component and a one-way valve body. The conduit component includes a three-way nozzle, a first conduit and a second conduit. The three-way nozzle is connected to the first conduit, and the first conduit is connected to the second conduit through the one-way valve body; the second conduit is connected to the extended oil inlet on the active cylinder end cover assembly.

[0006] The follower cylinder comprises a follower cylinder end cover assembly, a follower cylinder extension lock assembly, a follower cylinder outer cylinder assembly, a follower cylinder piston rod assembly, and a follower cylinder earring bolt assembly. The follower cylinder outer cylinder assembly comprises a follower cylinder outer cylinder, and a follower cylinder extension nozzle is arranged on the follower cylinder outer cylinder, and the follower cylinder extension nozzle is connected to the three-way nozzle.

[0007] The oil supply and return system is provided with an extending oil pipe and a retracting oil pipe, the extending oil pipe is connected to the three-way nozzle, and the retracting oil pipe is connected to the retracting oil inlet on the active cylinder outer cylinder assembly.

[0008] The active cylinder and the follower cylinder are arranged in the same direction, and the active cylinder end cover assembly and the follower cylinder end cover assembly as well as the active cylinder earring bolt assembly and the follower cylinder earring bolt assembly are all connected by a connecting rod; the one-way valve body starts to conduct after the oil pressure in the extending oil pipe of the oil supply and return system reaches the preset oil pressure A; the follower cylinder extension lock assembly is unlocked after reaching the preset oil pressure B; the preset oil pressure A is greater than the preset oil pressure B.

[0009] In order to better realize the present invention, further, the one-way valve body includes a valve body and a valve cover installed at both ends of the valve body through a valve group sealing member, the valve body is provided with an oil inlet hole and an oil return hole, the oil inlet hole is provided with a first valve core mounting hole, and the oil return hole is provided with a second valve core mounting hole; the first valve core mounting hole and the second valve core mounting hole are both installed with a screw plug and a valve stem, the valve stem is slidably connected to the screw plug, the first valve core mounting hole is also installed with a first valve group spring and a first valve core, the first valve core is connected to the valve stem on the first valve core mounting hole, the first valve group spring is arranged between the first valve core and the screw plug, and the screw plug on the first valve core mounting hole is used to limit the first valve group spring; the second valve core and the second valve group spring are also installed on the second valve core mounting hole, the second valve core is connected to the valve stem on the second valve core mounting hole, the second valve group spring is arranged between the second valve core and the screw plug, and the screw plug on the second valve core mounting hole is used to limit the second valve group spring.

[0010] In order to better realize the present invention, further, the active cylinder end cover assembly also includes an active cylinder end cover and a first active cylinder joint bearing; the active cylinder earring bolt assembly includes an active cylinder earring bolt, a second active cylinder joint bearing, and an active cylinder clamping nut; the first active cylinder joint bearing is installed on the active cylinder end cover; the active cylinder earring bolt is fixedly installed on the active cylinder piston rod assembly through the active cylinder clamping nut, and the second active cylinder joint bearing is installed on the active cylinder earring bolt.

[0011] In order to better realize the present invention, further, the three-way nozzle is provided with a first interface, a second interface, and a third interface, wherein the first interface is connected to the extended oil pipe on the oil supply and return system, the third interface is connected to the first conduit, and the second interface is connected to the follower cylinder extended nozzle through a hydraulic pipeline.

[0012] In order to better realize the present invention, further, the follower cylinder end cover assembly includes a follower cylinder end cover and a first follower cylinder joint bearing installed on the follower cylinder end cover; the follower cylinder outer cylinder assembly includes a sealing cover; the follower cylinder piston rod assembly includes a second follower cylinder piston rod and a follower cylinder piston rod support ring; the follower cylinder earring bolt assembly includes a follower cylinder earring bolt, a second follower cylinder joint bearing, and a follower cylinder clamping nut; the follower cylinder end cover is fixedly connected to the follower cylinder outer cylinder, the second follower cylinder piston rod is slidably connected to the follower cylinder outer cylinder, the follower cylinder piston rod support ring is installed on the second follower cylinder piston rod, and the sealing cover is used to close the gap between the follower cylinder outer cylinder assembly, the follower cylinder piston rod assembly and the second follower cylinder piston rod; the follower cylinder earring bolt is fixedly connected to the follower cylinder outer cylinder through the follower cylinder clamping nut, and the second follower cylinder joint bearing is installed on the follower cylinder earring bolt.

[0013] In order to better realize the present invention, further, the follower cylinder extension lock assembly includes a sealing sleeve, a follower cylinder spring sleeve, an extension spring, an adjusting gasket, and a locking ring; the follower cylinder piston rod assembly also includes an extension clamping ring and a slider; the sealing sleeve is installed on the follower cylinder outer cylinder, the follower cylinder outer cylinder cooperates with the sealing sleeve to achieve sealing, the follower cylinder spring sleeve is slidably installed on the sealing sleeve, and the follower cylinder spring sleeve is a circular step shape; the extension spring is installed on the follower cylinder end cover, the extension spring is connected to the follower cylinder spring sleeve, a locking ring and an adjusting gasket are installed on the follower cylinder outer cylinder, and the locking ring is used to limit the extension clamping ring; the extension clamping ring is sleeved on the second follower cylinder piston rod, the slider is slidably connected to the second follower cylinder piston rod, the extension clamping ring cooperates with the locking ring, and the slider cooperates with the follower cylinder spring sleeve.

[0014] A double-actuator retracting and extending method for landing gear retraction and extension, characterized in that it comprises the following steps:

[0015] Step S1, using the oil supply and return system to pump the hydraulic oil out from the retraction oil pipe, at this time the hydraulic oil is directly injected into the active cylinder, the active cylinder piston rod assembly and the active cylinder earring bolt assembly begin to drive the follower cylinder piston rod assembly and the follower cylinder earring bolt assembly to retract synchronously through the connecting rod, at this time the landing gear is lowered to perform the support operation;

[0016] Step S2, using the oil supply and return system to pump the hydraulic oil out from the extended oil pipe, and then part of the hydraulic oil is directly injected into the follower cylinder through the three-way nozzle, and the other part of the hydraulic oil flows through the control component and is injected into the driving cylinder;

[0017] Step S3, since the preset oil pressure A required for conducting the one-way valve body is greater than the preset oil pressure B for unlocking the follower cylinder extension lock assembly, the hydraulic oil will enter the active cylinder through the one-way valve body only after the follower cylinder extension lock assembly is unlocked; at this time, the active cylinder piston rod assembly and the active cylinder earring bolt assembly are extended, and at the same time, the active cylinder earring bolt assembly drives the follower cylinder piston rod assembly and the follower cylinder earring bolt assembly to extend synchronously through the connecting rod, so that the landing gear is retracted.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] (1) The present invention provides a follower cylinder II to assist the main cylinder I in extending and retracting, thereby improving the support strength and reducing the space occupied; the main cylinder is used to drive the follower cylinder to extend and retract, thereby avoiding force disputes;

[0020] (2) The present invention can realize oil circuit interconnection between the active cylinder I and the follower cylinder II by setting the one-way valve body 4, thereby controlling the unlocking sequence of the active cylinder I and the follower cylinder II, avoiding the disorder of the extension sequence of the active cylinder I and the follower cylinder II, reducing the control difficulty, and reducing the failure rate of the hydraulic control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the retractable system.

[0022] Figure 2 It is a cross-sectional view of the follower cylinder structure.

[0023] Figure 3 This is a cross-sectional view of the active cylinder structure.

[0024] Figure 4 A cross-sectional view of the follower cylinder extending the lock assembly structure

[0025] Figure 5 It is a cross-sectional view of the one-way valve body structure.

[0026] Figure 6 It is a cross-sectional view of the local structure of the one-way valve body.

[0027] Figure 7 This is a cross-sectional view of the three-way nozzle structure.

[0028] Among them: Ⅰ-active cylinder; Ⅱ-follower cylinder; 1-active cylinder end cover assembly; 2-conduit assembly; 3-active cylinder outer cylinder assembly; 4-check valve body; 5-active cylinder piston rod assembly; 6-active cylinder earring bolt assembly; 7-follower cylinder end cover assembly; 8-follower cylinder extension lock assembly; 9-follower cylinder outer cylinder assembly; 10-follower cylinder piston rod assembly; 11-follower cylinder earring bolt assembly; 12-oil supply and return system; 101-active cylinder end cover; 102-first active cylinder joint bearing; 103-three-way nozzle; 1031-first interface; 1032-second interface; 1033-third interface; 201-first conduit; 202-second conduit; 401-valve body; 4011-oil inlet hole; 4012-first valve core mounting hole; 4013-second valve core mounting hole; 4014-oil return hole; 402-valve cover; 403-screw Plug; 404-valve stem; 405-first valve group spring; 406-first valve core; 407-second valve core; 408-second valve group spring; 409-valve group seal; 601-active cylinder earring bolt; 602-second active cylinder joint bearing; 603-active cylinder clamping nut; 701-follower cylinder end cover; 702-first follower cylinder joint bearing; 801-sealing sleeve; 802-follower cylinder spring sleeve; 8 03-extension spring; 804-adjustment gasket; 805-locking ring; 901-follower cylinder outer cylinder; 902-follower cylinder extension nozzle; 903-sealing cover; 1001-second follower cylinder piston rod; 1002-extension clamping ring; 1003-slider; 1004-follower cylinder piston rod support ring; 1101-follower cylinder earring bolt; 1102-second follower cylinder joint bearing; 1103-follower cylinder clamping nut. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] 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.

[0031] Embodiment 1:

[0032] This embodiment provides a double-actuator retraction and extension system for landing gear, specifically, Figure 1-Figure 3 As shown, it includes an active cylinder Ⅰ, a control assembly, and a follower cylinder Ⅱ. The active cylinder Ⅰ includes an active cylinder end cover assembly 1, an active cylinder outer cylinder assembly 3, an active cylinder piston rod assembly 5, and an active cylinder earring bolt assembly 6, wherein the active cylinder end cover assembly 1, the active cylinder outer cylinder assembly 3, and the active cylinder piston rod assembly 5 cooperate to form an extension and retraction locking assembly; the active cylinder end cover assembly 1 is provided with an extension oil inlet; the active cylinder outer cylinder assembly 3 is provided with a retraction oil inlet; the specific structure of the active cylinder Ⅰ and the extension and retraction locking assembly provided in the active cylinder Ⅰ is the same as that in the prior art announcement number: CN1 The actuator structure disclosed in the Chinese invention patent 04500501B "Hydraulic floating snap ring lock" is the same. The actuator involved in the invention is mainly composed of "spring seat, first spring, support seat, actuator end cover, first gasket, snap ring seat, second gasket, actuator outer cylinder, retainer, first spring coil, floating slider group, spring group, floating piston, second spring coil, piston rod". Since the working principle has been described in detail in the invention, those skilled in the art can fully understand the present case based on the mentioned prior art, so the principle will not be repeated.

[0033] The control assembly includes a conduit assembly 2 and a one-way valve body 4. The conduit assembly 2 includes a three-way nozzle 103, a first conduit 201, and a second conduit 202. The three-way nozzle 103 is connected to the first conduit 201, and the first conduit 201 is connected to the second conduit 202 through the one-way valve body 4; the second conduit 202 is connected to the extended oil inlet on the active cylinder end cover assembly 1; the follower cylinder II includes a follower cylinder end cover assembly 7, a follower cylinder extension lock assembly 8, a follower cylinder outer cylinder assembly 9, The follower cylinder piston rod assembly 10, the follower cylinder earring bolt assembly 11, the follower cylinder outer cylinder assembly 9 includes a follower cylinder outer cylinder 901, the follower cylinder outer cylinder 901 is provided with a follower cylinder extension nozzle 902, the follower cylinder extension nozzle 902 is connected to the three-way nozzle 103; the oil supply and return system 12, the oil supply and return system 12 is provided with an extension oil pipe and a retraction oil pipe, the extension oil pipe is connected to the three-way nozzle 103, and the retraction oil pipe is connected to the retraction oil inlet on the active cylinder outer cylinder assembly 3.

[0034] The active cylinder I and the follower cylinder II are arranged in the same direction, and the active cylinder end cover assembly 1 and the follower cylinder end cover assembly 7 as well as the active cylinder earring bolt assembly 6 and the follower cylinder earring bolt assembly 11 are all connected by a connecting rod; the one-way valve body 4 starts to conduct after the oil pressure in the extending oil pipe of the oil supply and return system 12 reaches the preset oil pressure A; the follower cylinder extension lock assembly 8 is unlocked after reaching the preset oil pressure B; the preset oil pressure A is greater than the preset oil pressure B.

[0035] Based on the above system, a double actuator retraction method for landing gear retraction is provided, comprising the following steps:

[0036] Step S1, using the oil supply and return system 12 to pump the hydraulic oil out from the retraction oil pipe, at this time the hydraulic oil is directly injected into the active cylinder I, the active cylinder piston rod assembly 5 and the active cylinder earring bolt assembly 6 begin to drive the follower cylinder piston rod assembly 10 and the follower cylinder earring bolt assembly 11 to retract synchronously through the connecting rod, at this time the landing gear is lowered to perform the support operation;

[0037] Step S2, using the oil supply and return system 12 to pump the hydraulic oil out from the extended oil pipe, and then part of the hydraulic oil is directly injected into the follower cylinder II from the follower cylinder extended nozzle 902 through the three-way nozzle 103, and the other part of the hydraulic oil flows through the control component and is injected into the active cylinder I;

[0038] Step S3, since the preset oil pressure A required for conducting the one-way valve body 4 is greater than the preset oil pressure B for unlocking the follower cylinder extension lock assembly 8, as the oil pressure increases to the preset oil pressure B, the follower cylinder extension lock assembly 8 is first unlocked, and then the oil pressure continues to increase. When the oil pressure reaches the preset oil pressure A, the hydraulic oil begins to enter the active cylinder I through the one-way valve body 4; since the unlocking oil pressure of the extension and retraction locking assembly in the active cylinder I is not much different from the preset oil pressure B, the extension and retraction locking assembly will also be unlocked immediately, and the active cylinder piston rod assembly 5 and the active cylinder earring bolt assembly 6 are extended, and at the same time, the active cylinder earring bolt assembly 6 drives the follower cylinder piston rod assembly 10 and the follower cylinder earring bolt assembly 11 to extend synchronously through the connecting rod, so that the landing gear is retracted.

[0039] By setting the follower cylinder II to assist the main cylinder I in extending and retracting, the supporting strength is improved and the space occupied is reduced; by setting the one-way valve body 4, the oil circuit between the main cylinder I and the follower cylinder II can be cross-linked, so that the unlocking sequence of the main cylinder I and the follower cylinder II can be controlled, and there is no need to disassemble the main cylinder or the follower cylinder to adjust the unlocking pressure inside, thereby avoiding the situation where the main cylinder I and the follower cylinder II are extended in a disordered order, reducing the control difficulty and reducing the failure rate of the hydraulic control system.

[0040] Embodiment 2:

[0041] This embodiment further expands the one-way valve body 4 on the basis of the above embodiment. Figure 5 , Figure 6As shown, the one-way valve body 4 includes a valve body 401 and a valve cover 402 installed at both ends of the valve body 401 through a valve group seal 409, the valve body 401 is provided with an oil inlet hole 4011 and an oil return hole 4014, the oil inlet hole 4011 is provided with a first valve core mounting hole 4012, and the oil return hole 4014 is provided with a second valve core mounting hole 4013; the first valve core mounting hole 4012 and the second valve core mounting hole 4013 are both installed with a screw plug 403 and a valve stem 404, the valve stem 404 is slidably connected to the screw plug 403, the first valve group spring 405 and the first valve core 406 are also installed on the first valve core mounting hole 4012, the The first valve core 406 is connected to the valve stem 404 on the first valve core mounting hole 4012, the first valve group spring 405 is arranged between the first valve core 406 and the screw plug 403, and the screw plug 403 on the first valve core mounting hole 4012 is used to limit the first valve group spring 405; the second valve core 407 and the second valve group spring 408 are also installed on the second valve core mounting hole 4013, the second valve core 407 is connected to the valve stem 404 on the second valve core mounting hole 4013, the second valve group spring 408 is arranged between the second valve core 407 and the screw plug 403, and the screw plug 403 on the second valve core mounting hole 4013 is used to limit the second valve group spring 408.

[0042] When the active cylinder piston rod assembly 5 needs to be extended, the hydraulic oil is pumped into the one-way valve body 4. At this time, the hydraulic oil first enters the oil inlet hole 4011 and the second valve core mounting hole 4013. At this time, the second valve core 407 will block the oil return hole 4014 under the push of the oil, and the first valve core 406 will block the oil inlet hole 4011 under the action of the first valve group spring 405. When the oil pressure is greater than the preset oil pressure A, the hydraulic oil overcomes the elastic force of the first valve group spring 405 to push the first valve core 406. The hydraulic oil flows out from the first valve core mounting hole 4012, and then flows into the second conduit 202 through the valve cover 402 on this side, and then enters the active cylinder I.

[0043] When the active cylinder piston rod assembly 5 needs to be retracted, the hydraulic oil flows out from the active cylinder I. At this time, the hydraulic oil first enters the first valve core mounting hole 4012 and the oil return hole 4014 through the valve cover 402. The hydraulic oil is blocked by the first valve core 406 in the first valve core mounting hole 4012, and can overcome the elastic force of the second valve group spring 408 in the oil return hole 4014 to push open the second valve core 407, and then flows out from the second valve core mounting hole 4013, and then flows back to the oil supply and return system 12.

[0044] Through the above arrangement, it is possible to ensure that the hydraulic oil pressure is greater than the preset oil pressure A when the hydraulic oil is pumped into the active cylinder I. The preset oil pressure A can be changed by replacing the first valve group spring 405 of different specifications; and when the hydraulic oil flows back to the oil supply and return system 12, the second valve core 407 can be easily pushed to complete the reflux operation.

[0045] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0046] Embodiment 3:

[0047] This embodiment is further expanded on the basis of the above embodiment. Figure 3 As shown, the active cylinder end cover assembly 1 also includes an active cylinder end cover 101 and a first active cylinder joint bearing 102; the active cylinder earring bolt assembly 6 includes an active cylinder earring bolt 601, a second active cylinder joint bearing 602, and an active cylinder clamping nut 603; the first active cylinder joint bearing 102 is installed on the active cylinder end cover 101; the active cylinder earring bolt 601 is fixedly installed on the active cylinder piston rod assembly 5 through the active cylinder clamping nut 603, the second active cylinder joint bearing 602 is installed on the active cylinder earring bolt 601, and the two connecting rods are respectively installed on the first active cylinder joint bearing 102 and the second active cylinder joint bearing 602.

[0048] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0049] Embodiment 4:

[0050] This embodiment further expands the three-way nozzle 103 on the basis of the above embodiment. Figure 7 As shown, the three-way nozzle 103 is provided with a first interface 1031, a second interface 1032, and a third interface 1033, wherein the first interface 1031 is connected to the extended oil pipe on the oil supply and return system 12, the third interface 1033 is connected to the first conduit 201, and the second interface 1032 is connected to the follower cylinder extended nozzle 902 through a hydraulic pipeline.

[0051] The hydraulic oil in the oil pipe extending from the oil supply and return system 12 enters the first interface 1031 and is divided into two parts. One part enters the first conduit 201 from the third interface 1033, then flows into the one-way valve body 4, and then flows from the one-way valve body 4 into the second conduit 202, and finally flows into the active cylinder I; the other part flows from the second interface 1032 through the nozzle 902 extending from the follower cylinder into the follower cylinder II.

[0052] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0053] Embodiment 5:

[0054] This embodiment further expands the follower cylinder end cover assembly 7 on the basis of the above embodiment. Figure 2As shown, the follower cylinder end cover assembly 7 includes a follower cylinder end cover 701 and a first follower cylinder joint bearing 702 installed on the follower cylinder end cover 701; the follower cylinder outer cylinder assembly 9 includes a sealing cover 903; the follower cylinder piston rod assembly 10 includes a second follower cylinder piston rod 1001 and a follower cylinder piston rod support ring 1004; the follower cylinder earring bolt assembly 11 includes a follower cylinder earring bolt 1101, a second follower cylinder joint bearing 1102, and a follower cylinder clamping nut 1103; the follower cylinder end cover 701 is fixedly connected to the follower cylinder outer cylinder 901, and the second follower cylinder piston rod 100 1 is slidably connected to the follower cylinder outer cylinder 901, the follower cylinder piston rod support ring 1004 is installed on the second follower cylinder piston rod 1001, and the sealing cover 903 is used to close the gap between the follower cylinder outer cylinder assembly 9, the follower cylinder piston rod assembly 10 and the second follower cylinder piston rod 1001; the follower cylinder earring bolt 1101 is fixedly connected to the follower cylinder outer cylinder 901 through the follower cylinder clamping nut 1103, and the second follower cylinder joint bearing 1102 is installed on the follower cylinder earring bolt 1101; the first follower cylinder joint bearing 702 and the second follower cylinder joint bearing 1102 are respectively connected to the two connecting rods.

[0055] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0056] Embodiment 6:

[0057] This embodiment further expands the follower cylinder extension lock assembly 8 on the basis of the above embodiment. Figure 2 , Figure 4 As shown, the follower cylinder extension lock assembly 8 includes a sealing sleeve 801, a follower cylinder spring sleeve 802, an extension spring 803, an adjusting gasket 804, and a lock ring 805; the follower cylinder piston rod assembly 10 also includes an extension clamp ring 1002 and a slider 1003; the sealing sleeve 801 is installed on the follower cylinder outer cylinder 901, and the follower cylinder outer cylinder 901 cooperates with the sealing sleeve 801 to achieve sealing, and an unlocking cavity is provided on the sealing sleeve 801, and the follower cylinder spring sleeve 802 is slidably installed in the unlocking cavity on the sealing sleeve 801, and the unlocking cavity is connected to the follower cylinder extension nozzle 902, The follower cylinder spring sleeve 802 is in the shape of a circular step; the extending spring 803 is installed on the follower cylinder end cover 701, and the extending spring 803 is connected to the follower cylinder spring sleeve 802. A locking ring 805 and an adjusting gasket 804 are installed on the follower cylinder outer cylinder 901, and the locking ring 805 is used to limit the extending clamping ring 1002; the extending clamping ring 1002 is sleeved on the second follower cylinder piston rod 1001, and the slider 1003 is slidably connected to the second follower cylinder piston rod 1001, the extending clamping ring 1002 cooperates with the locking ring 805, and the slider 1003 cooperates with the follower cylinder spring sleeve 802.

[0058] When the oil enters the unlocking cavity from the follower cylinder extension nozzle 902, as the oil pressure increases, the extension spring 803 is compressed, and the follower cylinder spring sleeve 802 moves towards the follower cylinder end cover 701 until the follower cylinder spring sleeve 802 contacts the follower cylinder end cover 701, and the tapered end surface of the follower cylinder spring sleeve 802 causes the slider 1003 to lose support; when the second follower cylinder piston rod 1001 is extended, due to the limitation of the conical surface of the extension retaining ring 1002 on the conical surface of the locking ring 805, the extension retaining ring 1002 shrinks inwardly to squeeze the slider 1003, and the slider 1003 radially retracts into the second follower cylinder piston rod 1001. At this time, the locking ring 805 cannot limit the extension retaining ring 1002, and the second follower cylinder piston rod 1001 can be smoothly extended.

[0059] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A double-actuator retraction and extension system for landing gear, characterized in that: The invention comprises a driving cylinder (Ⅰ), wherein the driving cylinder (Ⅰ) comprises a driving cylinder end cover assembly (1), a driving cylinder outer cylinder assembly (3), a driving cylinder piston rod assembly (5), and a driving cylinder earring bolt assembly (6), wherein the driving cylinder end cover assembly (1), the driving cylinder outer cylinder assembly (3), and the driving cylinder piston rod assembly (5) cooperate to form an extension and retraction locking assembly; the driving cylinder end cover assembly (1) is provided with an extension oil inlet; and the driving cylinder outer cylinder assembly (3) is provided with a retraction oil inlet; A control assembly, the control assembly comprising a conduit assembly (2) and a one-way valve body (4); the conduit assembly (2) comprising a three-way nozzle (103), a first conduit (201), and a second conduit (202); the three-way nozzle (103) is connected to the first conduit (201); the first conduit (201) is connected to the second conduit (202) via the one-way valve body (4); the second conduit (202) is connected to a protruding oil inlet on an active cylinder end cover assembly (1); A follower cylinder (II), the follower cylinder (II) comprising a follower cylinder end cover assembly (7), a follower cylinder extension lock assembly (8), a follower cylinder outer cylinder assembly (9), a follower cylinder piston rod assembly (10), and a follower cylinder earring bolt assembly (11); the follower cylinder outer cylinder assembly (9) comprising a follower cylinder outer cylinder (901); a follower cylinder extension nozzle (902) being provided on the follower cylinder outer cylinder (901); and the follower cylinder extension nozzle (902) being connected to a three-way nozzle (103); An oil supply and return system (12), wherein the oil supply and return system (12) is provided with an extending oil pipe and a retracting oil pipe, wherein the extending oil pipe is connected to a three-way nozzle (103), and the retracting oil pipe is connected to a retracting oil inlet on the active cylinder outer cylinder assembly (3); The active cylinder (I) and the follower cylinder (II) are arranged in the same direction, and the active cylinder end cover assembly (1) and the follower cylinder end cover assembly (7) as well as the active cylinder earring bolt assembly (6) and the follower cylinder earring bolt assembly (11) are all connected by a connecting rod; the one-way valve body (4) starts to conduct after the oil pressure in the extension oil pipe of the oil supply and return system (12) reaches a preset oil pressure A; the follower cylinder extension lock assembly (8) is unlocked after reaching a preset oil pressure B; The preset oil pressure A is greater than the preset oil pressure B.

2. A double-actuator retraction and extension system for landing gear retraction and extension according to claim 1, characterized in that: The one-way valve body (4) comprises a valve body (401) and a valve cover (402) mounted on both ends of the valve body (401) via a valve group seal (409); the valve body (401) is provided with an oil inlet hole (4011) and an oil return hole (4014); the oil inlet hole (4011) is provided with a first valve core mounting hole (4012); the oil return hole (4014) is provided with a second valve core mounting hole (4013); a screw plug (403) and a valve stem (404) are mounted on the first valve core mounting hole (4012) and the second valve core mounting hole (4013); the valve stem (404) is slidably connected to the screw plug (403); the first valve group spring (405) and a first valve core (406) are also mounted on the first valve core mounting hole (4012); the first valve group spring (405) and a first valve core (406) are mounted on the second valve core mounting hole (4014); A valve core (406) is connected to the valve stem (404) on the first valve core mounting hole (4012), and a first valve group spring (405) is arranged between the first valve core (406) and the screw plug (403), and the screw plug (403) on the first valve core mounting hole (4012) is used to limit the first valve group spring (405); a second valve core (407) and a second valve group spring (408) are also installed on the second valve core mounting hole (4013), and the second valve core (407) is connected to the valve stem (404) on the second valve core mounting hole (4013), and the second valve group spring (408) is arranged between the second valve core (407) and the screw plug (403), and the screw plug (403) on the second valve core mounting hole (4013) is used to limit the second valve group spring (408).

3. A dual-actuator retraction and extension system for landing gear retraction according to claim 1, characterized in that: The driving cylinder end cover assembly (1) further comprises a driving cylinder end cover (101) and a first driving cylinder joint bearing (102); the driving cylinder earring bolt assembly (6) comprises a driving cylinder earring bolt (601), a second driving cylinder joint bearing (602), and a driving cylinder clamping nut (603); the first driving cylinder joint bearing (102) is mounted on the driving cylinder end cover (101); The driving cylinder piston rod assembly (5) is fixedly mounted with a driving cylinder earring bolt (601) via a driving cylinder clamping nut (603), and a second driving cylinder joint bearing (602) is mounted on the driving cylinder earring bolt (601).

4. A double-actuator retraction and extension system for landing gear retraction according to claim 1, characterized in that: The three-way nozzle (103) is provided with a first interface (1031), a second interface (1032), and a third interface (1033), wherein the first interface (1031) is connected to the extended oil pipe on the oil supply and return system (12), the third interface (1033) is connected to the first conduit (201), and the second interface (1032) is connected to the follower cylinder extended nozzle (902) through a hydraulic pipeline.

5. A double-actuator retraction and extension system for landing gear retraction according to claim 3, characterized in that: The follower cylinder end cover assembly (7) comprises a follower cylinder end cover (701) and a first follower cylinder joint bearing (702) mounted on the follower cylinder end cover (701); the follower cylinder outer cylinder assembly (9) comprises a sealing cover (903); the follower cylinder piston rod assembly (10) comprises a second follower cylinder piston rod (1001) and a follower cylinder piston rod support ring (1004); the follower cylinder earring bolt assembly (11) comprises a follower cylinder earring bolt (1101), a second follower cylinder joint bearing (1102), and a follower cylinder clamping nut (1103); the follower cylinder end cover (701) and the follower cylinder outer cylinder (9 01) is fixedly connected, the second follower cylinder piston rod (1001) is slidably connected to the follower cylinder outer cylinder (901), the follower cylinder piston rod support ring (1004) is installed on the second follower cylinder piston rod (1001), and the sealing cover (903) is used to close the gap between the follower cylinder outer cylinder assembly (9), the follower cylinder piston rod assembly (10) and the second follower cylinder piston rod (1001); the follower cylinder earring bolt (1101) is fixedly connected to the follower cylinder outer cylinder (901) through the follower cylinder clamping nut (1103), and the second follower cylinder joint bearing (1102) is installed on the follower cylinder earring bolt (1101).

6. A double-actuator retraction and extension system for landing gear retraction according to claim 1, characterized in that: The follower cylinder extension lock assembly (8) comprises a sealing sleeve (801), a follower cylinder spring sleeve (802), an extension spring (803), an adjustment gasket (804), and a lock ring (805); the follower cylinder piston rod assembly (10) further comprises an extension clamp ring (1002) and a slider (1003); the sealing sleeve (801) is mounted on the follower cylinder outer cylinder (901), the follower cylinder outer cylinder (901) cooperates with the sealing sleeve (801) to achieve sealing, the follower cylinder spring sleeve (802) is slidably mounted on the sealing sleeve (801), and the follower cylinder spring sleeve (802) is in the shape of a circular step; the extension spring (802) is provided on the sealing sleeve (801), and the extension spring (802) is provided on the sealing sleeve (801). 03) is installed on the follower cylinder end cover (701), the extension spring (803) is connected to the follower cylinder spring sleeve (802), the follower cylinder outer cylinder (901) is installed with a locking ring (805) and an adjusting gasket (804), the locking ring (805) is used to limit the extension clamping ring (1002); the extension clamping ring (1002) is sleeved on the second follower cylinder piston rod (1001), the slider (1003) is slidably connected to the second follower cylinder piston rod (1001), the extension clamping ring (1002) cooperates with the locking ring (805), and the slider (1003) cooperates with the follower cylinder spring sleeve (802).

7. A double-actuator retraction and extension method for landing gear retraction, using the retraction and extension system according to any one of claims 1 to 6, characterized in that: The steps include: Step S1, using the oil supply and return system (12) to pump hydraulic oil out from the retraction oil pipe, at this time the hydraulic oil is directly injected into the active cylinder (I), the active cylinder piston rod assembly (5) and the active cylinder earring bolt assembly (6) begin to drive the follower cylinder piston rod assembly (10) and the follower cylinder earring bolt assembly (11) to retract synchronously through the connecting rod, at this time the landing gear is lowered to perform the supporting operation; Step S2, using the oil supply and return system (12) to pump the hydraulic oil out from the extended oil pipe, and then part of the hydraulic oil is directly injected into the follower cylinder (II) through the three-way nozzle (103), and the other part of the hydraulic oil flows through the control component and is injected into the driving cylinder (I); Step S3, since the preset oil pressure A required for conducting the one-way valve body (4) is greater than the preset oil pressure B for unlocking the follower cylinder extension lock assembly (8), the hydraulic oil will enter the active cylinder (I) through the one-way valve body (4) only after the follower cylinder extension lock assembly (8) is unlocked; At this time, the active cylinder piston rod assembly (5) and the active cylinder earring bolt assembly (6) extend out, and at the same time, the active cylinder earring bolt assembly (6) drives the follower cylinder piston rod assembly (10) and the follower cylinder earring bolt assembly (11) to extend out synchronously through the connecting rod, so that the landing gear is retracted.

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