Two-stage lifting hydraulic control system and method for underwater vehicle

Abstract

The application discloses a two-stage lifting hydraulic control system and method for underwater vehicles, which comprises a first-stage liquid cylinder, a first reversing valve, a second-stage liquid cylinder, a second reversing valve, a first telescopic oil pipe assembly and a second telescopic oil pipe assembly. A first-stage piston built in the first-stage liquid cylinder separates the first-stage liquid cylinder into a first-stage rodless cavity and a first-stage rod cavity. The first-stage rod cavity is communicated with a first working oil port of the first reversing valve. The first-stage rodless cavity is communicated with a second working oil port of the first reversing valve. The second-stage liquid cylinder is fixed with the first-stage piston rod. An upper cavity of the second-stage liquid cylinder is communicated with an oil cavity of the first telescopic oil pipe assembly, and a lower cavity is communicated with an oil cavity of the second telescopic oil pipe assembly. The application has the beneficial effect that two telescopic oil pipe assemblies are used to synchronously stretch and retract with the first-stage piston rod, to adaptively match the volume change, and to continuously supply oil to the second-stage liquid cylinder at any position in the whole lifting stroke of the first-stage liquid cylinder.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, specifically to a two-stage lifting hydraulic control system and method for underwater vehicles. Background Technology

[0002] Underwater vehicles widely employ outboard lifting cylinders for raising and lowering, with some systems featuring secondary cylinders for actuation. These two cylinders need independent actuation, requiring hydraulic pressure to be supplied to the secondary cylinder. Currently, the mainstream hydraulic supply solutions for the secondary cylinder are mainly the following two: 1. Using a hydraulic catcher to supply oil. After the primary cylinder is raised to its position, the hydraulic catcher connects the oil circuit to the secondary cylinder, supplying oil. However, this method only supplies hydraulic pressure to the secondary cylinder after the primary cylinder is raised to its position, failing to achieve oil supply at any position or independent actuation of the two cylinders. 2. Using a follow-up hose as the hydraulic channel for the secondary cylinder. The follow-up hose uses pressure-resistant hoses or the system employs pressure compensation measures to resist external seawater pressure, enabling oil supply at any position throughout the entire stroke. However, the pressure-resistant hose has limited external pressure resistance, and as the external pressure resistance increases, the bending radius of the hose significantly increases, requiring a larger space and hindering the overall layout of the underwater vehicle. Furthermore, the system pressure compensation method requires the system back pressure to be higher than the outboard seawater pressure, resulting in high system pressure loss and low efficiency. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a two-stage lifting hydraulic control system and method for underwater vehicles, aiming to solve the problem that existing technologies cannot continuously supply oil at any stroke point.

[0004] The technical solution adopted in this invention is: a two-stage lifting hydraulic control system for underwater vehicles, comprising a primary hydraulic cylinder, a first reversing valve, a secondary hydraulic cylinder, a second reversing valve, a first telescopic oil pipe assembly, and a second telescopic oil pipe assembly; The primary hydraulic cylinder has a built-in primary piston, which is connected to a primary piston rod. The primary piston divides the interior of the primary hydraulic cylinder into a rodless chamber and a rod chamber 29. The interior of the first-stage rod chamber is connected to the first working port of the first directional valve via a first oil passage. The interior of the first-stage rodless chamber is connected to the second working port of the first directional valve via a second oil passage. The inlet of the first directional valve is connected to the system pressure oil circuit, and the return port of the first directional valve is connected to the oil tank. The secondary hydraulic cylinder is equipped with a secondary hydraulic cylinder, which contains a secondary piston. The secondary piston is connected to a secondary piston rod, and both the upper and lower ends of the secondary piston rod extend out of the secondary hydraulic cylinder. The bottom of the secondary hydraulic cylinder is fixedly connected to the upper end of the primary piston rod via a connecting plate. The secondary piston divides the interior of the secondary hydraulic cylinder into an upper chamber and a lower chamber; the upper chamber and the lower chamber are respectively equipped with a first telescopic oil pipe assembly and a second telescopic oil pipe assembly; Both sets of telescopic oil pipe assemblies are telescopic structures, and the telescopic ends of both are fixedly connected to the upper end of the first-stage piston rod; both sets of telescopic oil pipe assemblies are equipped with oil chambers that can change volume with telescopic movement. The upper chamber of the secondary hydraulic cylinder is connected to the oil chamber of the first telescopic oil pipe assembly through the third oil passage, and the oil chamber of the first telescopic oil pipe assembly is also connected to the first working oil port of the second reversing valve through the fifth oil passage; the lower chamber 31 of the secondary hydraulic cylinder is connected to the oil chamber of the second telescopic oil pipe assembly through the fourth oil passage, and the oil chamber of the second telescopic oil pipe assembly is also connected to the second working oil port of the second reversing valve through the sixth oil passage. The inlet of the second directional valve is connected to the system pressure oil circuit, and the return port of the second directional valve is connected to the return oil pipeline network.

[0005] According to the above scheme, the first telescopic oil pipe assembly and the second telescopic oil pipe assembly have the same structure, both including a movable sleeve and a fixed sleeve; the lower end of the fixed sleeve is fixed; the movable sleeve is sleeved outside the fixed sleeve, the upper end of the movable sleeve is closed, and serves as the telescopic end of the telescopic oil pipe assembly; the upper end of the fixed sleeve extends radially outward to form a connecting section, the outer periphery of the connecting section is slidably and sealingly connected to the inner periphery of the movable sleeve; the connecting section and the upper inner part of the movable sleeve enclose an oil cavity; the movable sleeves of the first telescopic oil pipe assembly and the second telescopic oil pipe assembly are respectively connected to the first-stage piston rod.

[0006] According to the above scheme, the outer periphery of the connecting section is adapted to the inner periphery of the movable sleeve through a support ring, and the outer periphery of the connecting section is sealed to the inner wall of the movable sleeve through a sealing ring.

[0007] According to the above scheme, the fifth oil circuit is connected to the seventh oil circuit and the eighth oil circuit respectively. The seventh oil circuit is equipped with a first check valve, and the eighth oil circuit is equipped with a first overflow valve.

[0008] According to the above scheme, the sixth oil circuit is connected to the ninth oil circuit and the tenth oil circuit respectively. The ninth oil circuit is equipped with a second check valve, and the tenth oil circuit is equipped with a second overflow valve.

[0009] According to the above scheme, the first telescopic oil pipe assembly and the second telescopic oil pipe assembly are both located outside the first-stage hydraulic cylinder, and the upper ends of the movable sleeves of the two sets of telescopic oil pipe assemblies are respectively connected to the first-stage piston rod of the first-stage hydraulic cylinder through connecting plates.

[0010] According to the above scheme, the lower ends of the fixed sleeves of the two sets of telescopic oil pipe assemblies are fixedly connected to the hull base of the underwater vehicle or the mounting seat of the first-stage hydraulic cylinder.

[0011] According to the above scheme, the first telescopic oil pipe assembly and the second telescopic oil pipe assembly are nested side by side inside the first-stage piston rod of the first-stage hydraulic cylinder; and the lower ends of the fixed sleeves of the two sets of telescopic oil pipe assemblies extend from the lower end of the first-stage piston and are fixed on the mounting seat of the first-stage hydraulic cylinder or the hull base.

[0012] According to the above plan, both the first-stage hydraulic cylinder and the second-stage hydraulic cylinder are located outside the hull of the underwater vehicle.

[0013] The present invention also provides a two-stage lifting hydraulic control method for underwater vehicles. The method is as follows: during the upward movement of the first-stage piston rod of the first-stage hydraulic cylinder, the first telescopic oil pipe assembly, the telescopic ends of the second telescopic oil pipe assembly, and the entire second-stage hydraulic cylinder are simultaneously stretched upward. The internal oil chamber volume of the two sets of telescopic oil pipe assemblies increases synchronously and the internal pressure decreases. At this time, the system is connected through the seventh oil circuit and the ninth oil circuit respectively to automatically replenish oil to the first telescopic oil pipe assembly and the second telescopic oil pipe assembly. As the first piston rod of the first stage hydraulic cylinder descends, it simultaneously compresses the two sets of telescopic oil pipe assemblies, causing the internal oil chamber volume of the telescopic oil pipe assembly to decrease and the internal oil pressure to increase. When the internal pressure reaches the maximum set pressure of the system, the first relief valve and the second relief valve open to release pressure, and the excess oil in the telescopic oil pipe assembly flows into the return oil network through the eighth oil passage and the tenth oil passage, respectively.

[0014] The beneficial effects of this invention are as follows: 1. This invention designs two sets of telescopic oil pipe assemblies. The two sets of telescopic oil pipe assemblies extend and retract synchronously with the first-stage piston rod, adaptively matching the volume change. This allows for continuous oil supply to the second-stage hydraulic cylinder at any position during the entire lifting and lowering stroke of the first-stage hydraulic cylinder, solving the defect of traditional hydraulic catchers that can only supply oil after the first stage is in position. Two sets of independent reversing valves are set to regulate the oil circuits of the first-stage and second-stage hydraulic cylinders respectively. The two-stage hydraulic cylinder drives do not interfere with each other and the actions are independently controlled, resulting in greater flexibility.

[0015] 2. The telescopic tubing assembly of the present invention adopts a rigid tubing structure with a movable tubing nested within a fixed tubing. It relies on the tubing to enclose and seal the oil cavity to transport oil. The overall structure is highly rigid and has better resistance to external pressure from seawater. Moreover, the telescopic movement of the two tubings is stable. Compared with traditional hoses, there is no risk of bending fatigue damage. It is suitable for long-term high-pressure working conditions in deep sea. At the same time, the overall structure is compact and occupies little space.

[0016] 3. The telescopic oil pipe assembly in this invention adopts an external arrangement, which makes assembly and disassembly convenient and provides sufficient space for later maintenance and seal replacement, making it suitable for aircraft with low space requirements.

[0017] 4. In this invention, the telescopic oil pipe assembly is embedded and integrated inside the first-stage piston rod, with a very high degree of integration, which can reduce the volume of exposed parts outside the hull. Attached Figure Description

[0018] Appendix Figure 1 This is a diagram of an external telescopic oil pipe two-stage lifting hydraulic system.

[0019] Appendix Figure 2 Schematic diagram of the external telescopic oil pipe assembly. Appendix Figure 3 This is a diagram of a two-stage lifting hydraulic system with a built-in telescopic oil pipe.

[0020] Appendix Figure 4 This is a schematic diagram of the built-in telescopic oil pipe assembly.

[0021] As shown in the figure, 1. First-stage hydraulic cylinder; 2. Second-stage hydraulic cylinder; 3. First telescopic oil pipe assembly; 4. First directional valve; 5. Second directional valve; 6. First check valve; 7. First relief valve; 8. Second telescopic oil pipe assembly; 9. First-stage piston rod; 10. Movable sleeve; 11. Support ring; 12. Sealing ring; 13. Fixed sleeve; 14. First oil passage; 15. Second oil passage; 16. Third oil passage; 17. Fourth oil passage; 18. Fifth oil passage; 19. Sixth oil passage; 20. Seventh oil passage; 21. Eighth oil passage; 22. Ninth oil passage; 23. Tenth oil passage; 24. Second check valve; 25. Second relief valve; 26. Hull base; 27. Mounting seat; 28. First-stage rodless chamber; 29. ​​First-stage rod chamber; 30. Upper chamber; 31. Lower chamber; 32. Connecting section; 33. Connecting plate. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0025] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, the term "a plurality of" indicates two or more.

[0027] A two-stage lifting hydraulic control system for an underwater vehicle includes a primary hydraulic cylinder 1, a first directional valve 4, a secondary hydraulic cylinder 2, a second directional valve 5, a first telescopic oil pipe assembly 3, and a second telescopic oil pipe assembly 8. The first-stage hydraulic cylinder 1 is arranged outside the hull of the underwater vehicle. The first-stage hydraulic cylinder 1 has a built-in first-stage piston, which is connected to a first-stage piston rod 9. The first-stage piston divides the interior of the first-stage hydraulic cylinder 1 into a first-stage rodless chamber 28 and a first-stage rod chamber 29. The interior of the first-stage rod chamber 29 is connected to the first working port of the first directional valve 4 via the first oil passage 14. The interior of the first rodless chamber 28 is connected to the second working port of the first directional valve 4 through the second oil passage 15. The oil inlet of the first reversing valve 4 is connected to the system pressure oil circuit, and the oil return port of the first reversing valve 4 is connected to the oil tank. The secondary hydraulic cylinder 2 is equipped with a secondary hydraulic cylinder 2, which has a built-in secondary piston. The secondary piston is connected to a secondary piston rod, and both the upper and lower ends of the secondary piston rod extend out of the secondary hydraulic cylinder 2. The bottom of the secondary hydraulic cylinder 2 is fixedly connected to the upper end of the primary piston rod 9 through a connecting plate 33. The secondary piston divides the interior of the secondary hydraulic cylinder 2 into an upper chamber 30 and a lower chamber 31; the upper chamber 30 and the lower chamber 31 are respectively equipped with a first telescopic oil pipe assembly 3 and a second telescopic oil pipe assembly 8. Both sets of telescopic oil pipe assemblies are telescopic structures, and the telescopic ends of both are fixedly connected to the upper end of the first-stage piston rod 9; both sets of telescopic oil pipe assemblies are equipped with oil chambers that can change volume with telescopic movement. The upper cavity 30 of the secondary hydraulic cylinder 2 is connected to the oil cavity of the first telescopic oil pipe assembly 3 through the third oil passage 16. The oil cavity of the first telescopic oil pipe assembly 3 is also connected to the first working oil port of the second reversing valve 5 through the fifth oil passage 18. The lower cavity 31 of the secondary hydraulic cylinder 2 is connected to the oil cavity of the second telescopic oil pipe assembly 8 through the fourth oil passage 17. The oil cavity of the second telescopic oil pipe assembly 8 is also connected to the second working oil port of the second reversing valve 5 through the sixth oil passage 19. The inlet of the second directional valve 5 is connected to the system pressure oil circuit, and the return port of the second directional valve 5 is connected to the return oil pipeline.

[0028] In this invention, both the primary hydraulic cylinder 1 and the secondary hydraulic cylinder 2 are located outside the hull of the underwater vehicle. Both the first reversing valve 4 and the second reversing valve 5 are four-port reversing valves, with four ports: an oil inlet, an oil return port, a first working oil port, and a second working oil port. Each port corresponds to a fixed oil circuit connection. The first reversing valve 4 controls the oil inlet and return switching between the primary rod chamber 29 and the primary rodless chamber 28 by switching the oil circuit on / off state, thus achieving the primary lifting and lowering adjustment of the primary hydraulic cylinder 1 by extending and retracting as a whole. The second reversing valve 5 controls the oil circuit on / off of the secondary hydraulic cylinder 2 through a telescopic oil pipe assembly, switching the oil inlet and return working conditions between the upper chamber 30 and the lower chamber 31 of the secondary hydraulic cylinder 2. This allows the extension and retraction adjustment of the secondary hydraulic cylinder 2 to be completed independently while the primary hydraulic cylinder 1 remains stationary or in operation.

[0029] Preferably, the first telescopic oil pipe assembly 3 and the second telescopic oil pipe assembly 8 have the same structure, both including a movable sleeve 10 and a fixed sleeve 13; the lower end of the fixed sleeve 13 is fixed; the movable sleeve 10 is sleeved outside the fixed sleeve 13, the upper end of the movable sleeve 10 is closed, and serves as the telescopic end of the telescopic oil pipe assembly; the upper end of the fixed sleeve 13 extends radially outward to form a connecting section 32, the outer periphery of the connecting section 32 is slidably and sealingly connected to the inner circumferential surface of the movable sleeve 10; the connecting section 32 and the upper inner part of the movable sleeve 10 enclose an oil cavity; the movable sleeve 10 of the first telescopic oil pipe assembly 3 and the movable sleeve 10 of the second telescopic oil pipe assembly 8 are respectively connected to the first-stage piston rod 9.

[0030] Preferably, the outer periphery of the connecting section 32 is adapted to the inner circumferential surface of the movable sleeve 10 through the support ring 11, and the outer circumferential surface of the connecting section 32 is sealed to the inner wall surface of the movable sleeve 10 through the sealing ring 12.

[0031] In this invention, the sealing ring 12 adopts a bidirectional sealing design, and the sealing pressure meets the sealing requirements under the maximum hydraulic system pressure or external seawater pressure. The support ring 11 is used to guide the relative extension and retraction movement of the movable sleeve 10 and the fixed sleeve 13 to ensure smooth operation.

[0032] In this invention, the movable sleeves 10 of the two sets of telescopic oil pipe assemblies extend or retract under the drive of the first-stage hydraulic cylinder 1, realizing the follow-up oil supply of the second-stage hydraulic cylinder 2: when the movable sleeve 10 is stretched upward, the distance between the connection head of the movable sleeve 10 and the fixed sleeve 13 increases, the oil chamber volume increases, and oil is replenished through the corresponding oil passage; when the movable sleeve 10 is compressed downward, the distance between the connection head of the movable sleeve 10 and the fixed sleeve 13 decreases, the oil chamber volume decreases, and oil overflows through the corresponding oil passage.

[0033] Preferably, the fifth oil passage 18 is connected to the seventh oil passage 20 and the eighth oil passage 21 respectively. The seventh oil passage 20 is equipped with a first check valve 6, and the eighth oil passage 21 is equipped with a first overflow valve 7.

[0034] Preferably, the sixth oil passage 19 is connected to the ninth oil passage 22 and the tenth oil passage 23 respectively. The ninth oil passage 22 is equipped with a second check valve 24, and the tenth oil passage 23 is equipped with a second overflow valve 25.

[0035] In this invention, the seventh oil circuit 20 serves as the replenishment line for the fifth oil circuit 18, and the eighth oil circuit 21 serves as the overflow line for the fifth oil circuit 18, relieving pressure. The ninth oil circuit 22 is used to replenish the replenishment line for the sixth oil circuit 19, and the tenth oil circuit 23 serves as the overflow line for the sixth oil circuit 19, relieving pressure. The seventh, eighth, ninth, and tenth oil circuits are all connected to the return oil network. This invention includes independent overflow valves and check valves for replenishing or releasing oil in the telescopic oil pipe assembly, meeting the oil supply requirements during the upward or downward movement of the secondary hydraulic cylinder 2. The release pressure of the overflow valve is set to the maximum system pressure. Other configurations on each oil circuit, such as valves, are existing technologies and will not be described further here.

[0036] In this invention, the telescopic oil pipe assembly can achieve sealing under high pressure, meeting the needs of deep-sea environments; the telescopic oil pipe assembly can be set up with one oil circuit or integrate multiple oil circuits.

[0037] A two-stage lifting hydraulic control method for an underwater vehicle, the method being as follows: When the first-stage hydraulic cylinder 1 needs to extend upwards, the first directional valve 4 completes the oil circuit reversal switch. The system pressure oil enters through the oil inlet of the first directional valve 4, and then enters the first-stage rodless chamber 28 of the first-stage hydraulic cylinder 1 through the second working oil port of the first directional valve 4 and the second oil circuit 15. At the same time, the oil inside the first-stage rod chamber 29 flows back to the first working oil port of the first directional valve 4 through the first oil circuit 14, and finally flows back to the oil tank through the return oil port of the first directional valve 4, pushing the first-stage piston to drive the first-stage piston rod 9 to extend upwards, realizing the overall lifting and extending action of the first-stage cylinder; the first-stage piston rod 9 During the upward movement, the telescopic ends (specifically the movable sleeve 10) of the first telescopic oil pipe assembly 3 and the second telescopic oil pipe assembly 8, as well as the entire secondary hydraulic cylinder 2, are simultaneously stretched upward. The internal oil chamber volume of the two sets of telescopic oil pipe assemblies increases synchronously, and the internal pressure decreases. At this time, the system is connected through the seventh oil circuit 20 and the ninth oil circuit 22 respectively. Relying on the one-way conduction action of the first check valve 6 and the second check valve 24, oil is automatically replenished to the inside of the first telescopic oil pipe assembly 3 and the second telescopic oil pipe assembly 8, so as to realize the follow-up oil replenishment at any position of the secondary hydraulic cylinder. When the first-stage hydraulic cylinder 1 needs to retract downwards, the first directional valve 4 switches the valve core position again to realize the oil circuit reversal. The system pressure oil enters the first-stage rod chamber 29 through the first working port of the first directional valve 4 and the first oil circuit 14. The oil inside the first-stage rodless chamber 28 flows back to the second working port of the first directional valve 4 through the second oil circuit 15 and flows back to relieve pressure, driving the first-stage piston to drive the first-stage piston rod 9 to move downwards and reset. During the downward movement of the first-stage piston rod 9, the two sets of telescopic oil pipe assemblies are compressed simultaneously, which reduces the volume of the oil chamber inside the telescopic oil pipe assembly and increases the oil pressure inside the chamber. When the pressure inside the chamber reaches the maximum set pressure of the system, the first relief valve 7 and the second relief valve 25 open to relieve pressure. The excess oil in the telescopic oil pipe assembly flows into the return oil network through the eighth oil circuit 21 and the tenth oil circuit 23 respectively.

[0038] In this invention, two sets of telescopic oil pipe assemblies extend or retract synchronously under the drive of the primary hydraulic cylinder 1, realizing the follow-up oil supply of the secondary hydraulic cylinder 2. After the secondary hydraulic cylinder 2 is stretched to its position under the action of the primary piston rod 9, it extends and retracts under the action of the second reversing valve 5. Specifically, the working principle of the secondary hydraulic cylinder 2 is as follows: When the secondary piston rod of the secondary hydraulic cylinder 2 needs to extend upward, the second directional valve 5 switches the valve core position to complete the oil circuit switching. The system pressure oil is introduced through the oil inlet of the second directional valve 5 and enters the lower chamber 31 of the secondary hydraulic cylinder 2 through the sixth oil circuit 19, the oil chamber of the second telescopic oil pipe assembly 8, and the fourth oil circuit 17. At the same time, the oil inside the upper chamber 30 flows back to the first working oil port of the second directional valve 5 through the third oil circuit 16, the oil chamber of the first telescopic oil pipe assembly 3, and the fifth oil circuit 18. Finally, it flows back to the oil tank through the return oil port of the second directional valve 5, pushing the secondary piston and driving the secondary piston rod to extend upward. When the secondary piston rod of the secondary hydraulic cylinder 2 needs to retract downwards, the second directional valve 5 switches the valve core position to realize the oil circuit switching. The system pressure oil is introduced through the oil inlet of the second directional valve 5 and enters the upper cavity 30 of the secondary hydraulic cylinder 2 through the fifth oil circuit 18, the oil chamber of the first telescopic oil pipe assembly 3, and the third oil circuit 16. At the same time, the oil inside the lower cavity 31 flows back to the second working oil port of the second directional valve 5 through the fourth oil circuit 17, the oil chamber of the second telescopic oil pipe assembly 8, and the sixth oil circuit 19. Finally, it flows back to the oil tank through the return oil port of the second directional valve 5, pushing the secondary piston and driving the secondary piston rod to retract downwards.

[0039] Example 1 refer to Figure 1 and Figure 2 The diagram illustrates a two-stage lifting hydraulic control system for an underwater vehicle. In this system, the two sets of telescopic hydraulic pipe assemblies are externally mounted. Specifically, the first telescopic hydraulic pipe assembly 3 and the second telescopic hydraulic pipe assembly 8 are both located outside the first-stage hydraulic cylinder 1. The upper ends of the movable sleeves 10 of both sets of telescopic hydraulic pipe assemblies are connected to the first-stage piston rod 9 of the first-stage hydraulic cylinder 1 via connecting plates 33. The lower ends of the fixed sleeves 13 of both sets of telescopic hydraulic pipe assemblies are fixedly connected to the hull base 26 of the underwater vehicle or the mounting base 27 of the first-stage hydraulic cylinder 1.

[0040] In this embodiment, the first-stage hydraulic cylinder 1 adopts a double-acting single-rod hydraulic cylinder form, which is controlled by the first reversing valve 4 to extend or retract, thereby driving the second-stage hydraulic cylinder 2 to rise or fall synchronously, and driving the two sets of telescopic oil pipe assemblies to extend or retract synchronously.

[0041] In this embodiment, the secondary hydraulic cylinder 2 adopts a double-rod hydraulic cylinder design, and its extension or retraction is controlled by the second directional valve 5. The lower chamber 31 of the secondary hydraulic cylinder 2 is equipped with a first check valve 6 connected to the oil replenishment line, and a first overflow valve 7 connected to the oil overflow line; the upper chamber 30 is equipped with a second check valve 24 connected to the oil replenishment line, and a second overflow valve 25 connected to the oil overflow line. The pressure settings of both sets of overflow valves are the same as the system pressure.

[0042] In this embodiment, when the first-stage hydraulic cylinder 1 extends, the internal volume of the oil chamber of the telescopic oil pipe assembly increases and the pressure decreases. Oil is then replenished to the corresponding telescopic oil pipe assembly via the first one-way valve 6 and the second one-way valve 24, respectively. When the first-stage hydraulic cylinder 1 retracts, the internal volume of the oil chamber of the telescopic oil pipe assembly decreases and the internal pressure increases. Excess oil in the corresponding telescopic oil pipe assembly is discharged via the first overflow valve 7 and the second overflow valve 25.

[0043] Example 2 Reference Figure 3 and Figure 4 The diagram illustrates a two-stage lifting hydraulic control system for an underwater vehicle. In this system, two sets of telescopic hydraulic pipe assemblies are internally integrated. Specifically, the first telescopic hydraulic pipe assembly 3 and the second telescopic hydraulic pipe assembly 8 are nested side-by-side within the first-stage piston rod 9 of the first-stage cylinder 1. The lower ends of the fixed sleeves 13 of both sets of telescopic hydraulic pipe assemblies extend from the lower end of the first-stage piston and are fixed to the mounting base 27 of the first-stage cylinder 1 or the hull base 26. The movable sleeves 10 of the two sets of telescopic hydraulic pipe assemblies are integrated and rise and fall synchronously with the first-stage piston rod 9.

[0044] In this embodiment, the operation control method of the primary hydraulic cylinder 1 and the secondary hydraulic cylinder 2 is the same as that in Embodiment 1.

[0045] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0046] Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A two-stage lifting hydraulic control system for an underwater vehicle, characterized in that, It includes a primary hydraulic cylinder, a first directional valve, a secondary hydraulic cylinder, a second directional valve, a first telescopic oil pipe assembly, and a second telescopic oil pipe assembly; The primary hydraulic cylinder has a built-in primary piston, which is connected to a primary piston rod. The primary piston divides the interior of the primary hydraulic cylinder into a rodless chamber and a rod chamber. The interior of the first-stage rod chamber is connected to the first working port of the first directional valve via a first oil passage. The interior of the first-stage rodless chamber is connected to the second working port of the first directional valve via a second oil passage. The inlet of the first directional valve is connected to the system pressure oil circuit, and the return port of the first directional valve is connected to the oil tank. The secondary hydraulic cylinder is equipped with a secondary hydraulic cylinder, which contains a secondary piston. The secondary piston is connected to a secondary piston rod, and both the upper and lower ends of the secondary piston rod extend out of the secondary hydraulic cylinder. The bottom of the secondary hydraulic cylinder is fixedly connected to the upper end of the primary piston rod via a connecting plate. The secondary piston divides the interior of the secondary hydraulic cylinder into an upper chamber and a lower chamber; the upper chamber and the lower chamber are respectively equipped with a first telescopic oil pipe assembly and a second telescopic oil pipe assembly; Both sets of telescopic oil pipe assemblies are telescopic structures, and the telescopic ends of both are fixedly connected to the upper end of the first-stage piston rod; both sets of telescopic oil pipe assemblies are equipped with oil chambers whose volume changes with telescopic movement. The upper chamber of the secondary hydraulic cylinder is connected to the oil chamber of the first telescopic oil pipe assembly through the third oil passage, and the oil chamber of the first telescopic oil pipe assembly is also connected to the first working oil port of the second reversing valve through the fifth oil passage; the lower chamber of the secondary hydraulic cylinder is connected to the oil chamber of the second telescopic oil pipe assembly through the fourth oil passage, and the oil chamber of the second telescopic oil pipe assembly is also connected to the second working oil port of the second reversing valve through the sixth oil passage. The inlet of the second directional valve is connected to the system pressure oil circuit, and the return port of the second directional valve is connected to the return oil pipeline network.

2. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 1, characterized in that, The first and second telescopic oil pipe assemblies have the same structure, both including a movable sleeve and a fixed sleeve; the lower end of the fixed sleeve is fixed; the movable sleeve is sleeved outside the fixed sleeve, the upper end of the movable sleeve is closed, and serves as the telescopic end of the telescopic oil pipe assembly; the upper end of the fixed sleeve extends radially outward to form a connecting section, the outer periphery of the connecting section is slidably and sealingly connected to the inner periphery of the movable sleeve; the connecting section and the upper inner part of the movable sleeve enclose an oil cavity; the movable sleeves of the first and second telescopic oil pipe assemblies are respectively connected to the first-stage piston rod.

3. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 2, characterized in that, The outer periphery of the connecting section is adapted to the inner circumferential surface of the movable sleeve through a support ring, and the outer circumferential surface of the connecting section is sealed to the inner wall surface of the movable sleeve through a sealing ring.

4. The two-stage lifting hydraulic control system for underwater vehicles as described in any one of claims 1 to 3, characterized in that, The fifth oil circuit is connected to the seventh oil circuit and the eighth oil circuit respectively. The seventh oil circuit is equipped with a first check valve, and the eighth oil circuit is equipped with a first overflow valve.

5. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 4, characterized in that, The sixth oil circuit is connected to the ninth and tenth oil circuits respectively. The ninth oil circuit is equipped with a second check valve, and the tenth oil circuit is equipped with a second overflow valve.

6. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 5, characterized in that, The first telescopic oil pipe assembly and the second telescopic oil pipe assembly are both located outside the first-stage hydraulic cylinder, and the upper ends of the movable sleeves of the two sets of telescopic oil pipe assemblies are respectively connected to the first-stage piston rod of the first-stage hydraulic cylinder through connecting plates.

7. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 6, characterized in that, The lower ends of the fixed sleeves of both sets of telescopic oil pipe assemblies are fixedly connected to the hull base of the underwater vehicle or the mounting base of the first-stage hydraulic cylinder.

8. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 5, characterized in that, The first and second telescopic oil pipe assemblies are nested side by side inside the first-stage piston rod of the first-stage hydraulic cylinder; and the lower ends of the fixed sleeves of the two sets of telescopic oil pipe assemblies extend from the lower end of the first-stage piston and are fixed on the mounting seat of the first-stage hydraulic cylinder or the hull base.

9. The two-stage lifting hydraulic control system for underwater vehicles as described in claim 1, characterized in that, Both the primary and secondary hydraulic cylinders are located outside the hull of the underwater vehicle.

10. A two-stage lifting hydraulic control method for an underwater vehicle, wherein the method is implemented by the two-stage lifting hydraulic control system for an underwater vehicle as described in any one of claims 5 to 9, characterized in that, The method is as follows: During the upward movement of the first piston rod of the first stage hydraulic cylinder, the first telescopic oil pipe assembly, the telescopic ends of the second telescopic oil pipe assembly, and the second stage hydraulic cylinder as a whole are simultaneously stretched upward. The internal oil chamber volume of the two sets of telescopic oil pipe assemblies increases synchronously and the internal pressure decreases. At this time, the system automatically replenishes oil to the first telescopic oil pipe assembly and the second telescopic oil pipe assembly through the seventh oil circuit and the ninth oil circuit, respectively. As the first piston rod of the first stage hydraulic cylinder descends, it simultaneously compresses the two sets of telescopic oil pipe assemblies, causing the internal oil chamber volume of the telescopic oil pipe assembly to decrease and the internal oil pressure to increase. When the internal pressure reaches the maximum set pressure of the system, the first relief valve and the second relief valve open to release pressure, and the excess oil in the telescopic oil pipe assembly flows into the return oil network through the eighth oil passage and the tenth oil passage, respectively.

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