Hydraulic control system for a lifeboat launching device

Abstract

The application discloses a kind of hydraulic control system of lifeboat lowering device, including oil tank, hydraulic cylinder, energy accumulator, motor valve group, hydraulic motor;The hydraulic control system of this kind of lifeboat lowering device improves the oil supplement mode when the hydraulic motor of boat winch is lowered by gravity, can be infinitely supplemented to the gravity lowering loop of boat winch, without increasing the energy accumulator for oil supplement or increasing the auxiliary oil tank for oil supplement;At the same time, the working circuit of boat winch when manually lifting lifeboat is improved, and the efficiency and speed of manually lifting lifeboat by boat winch are improved.Compared with prior art, the energy accumulator directly drives the hydraulic cylinder to retract function is added, the energy stored in the energy accumulator can be fully utilized, and the rescue time in emergency state is saved.

Description

Technical Field

[0001] This article relates to a hydraulic control system for a lifeboat launching and lowering device. Background Technology

[0002] With the continuous development of global trade, the shipping industry, as an important part of trade, has received widespread attention for its security.

[0003] In accordance with the relevant requirements of the International Convention for the Safety of Life at Sea (SOLAS) and the International Lifesaving Equipment (LSA) Code, all vessels engaged in international voyages must be equipped with sling-launch lifeboats capable of launching and lowering the lifeboats or rafts they serve using only gravity or stored mechanical energy independent of the ship's power. Furthermore, the lifeboat launching and lowering system must also be capable of manually retrieving the lifeboats or rafts it serves.

[0004] In existing hydraulically driven hoisting lifeboat lowering devices, the process of lowering the lifeboat by gravity usually relies on an accumulator or winch auxiliary oil tank to replenish the hydraulic motor of the lifting winch due to its own leakage loss. The accumulator or winch auxiliary oil tank needs to be enlarged as the lifting winch lowers, resulting in a very bulky structure for the lowering device and a significant increase in cost.

[0005] In addition, during the manual lifting of the lifeboats by the lifeboat lowering and launching device, the hydraulic motor of the lifeboat winch is often driven directly by a manual pump. However, due to the oil suction and pressure process of the manual pump, the manual pump does not continuously output high-pressure oil during operation. As a result, during the oil suction and pressure building period of the manual pump, a large amount of pressurized oil is consumed due to leakage loss of the hydraulic motor before the lifeboat is lifted by the lifeboat winch. This greatly reduces the efficiency and speed of the lifeboat lifting by the lifeboat winch when lifting the lifeboat manually, and the lifting effect is often unsatisfactory. Summary of the Invention

[0006] To address the aforementioned issues, this paper proposes a hydraulic control system for a lifeboat lowering and launching device that can replenish oil based on gravity and operate more rapidly.

[0007] A hydraulic control system for a lifeboat launching device includes an oil tank, a hydraulic cylinder, an accumulator, a motor valve group, and a hydraulic motor.

[0008] The oil outlet of the oil tank is connected to the multi-way valve through the oil pump motor unit and the first check valve. The multi-way valve is equipped with an overflow valve and at least two working plates. The return port of the multi-way valve is connected to the oil tank through the back pressure valve and the return oil filter.

[0009] The working port of the cylinder working plate of the multi-way valve is connected to the rodless chamber of the hydraulic cylinder through the first manual valve and the two-way balance valve. At the same time, the piston rod chamber of the hydraulic cylinder is connected to the other working port of the working plate on the multi-way valve through the two-way balance valve and the second manual valve.

[0010] The accumulator is connected to the motor valve group via the second shut-off valve and the third manual valve. When high-pressure oil enters the motor valve group through the third manual valve, the brake control oil circuit of the motor valve group opens the brake. Due to the load, pressure oil is formed at the motor B1 port, which drives the booster pump after passing through the hydraulic control directional valve and the speed control valve. The oil outlet of the booster pump replenishes oil to the motor A1 port through the check valve. Excess oil from the replenishment flows back to the oil tank through the winch working plate of the multi-way valve and the back pressure valve. At this time, the gravity launching boat action is performed.

[0011] The accumulator is connected to the motor valve group through the second shut-off valve, the fourth manual valve, and the hydraulic directional valve. When high-pressure oil enters the motor valve group through the fourth manual valve, the brake inside the motor valve group is released. The high-pressure oil at port B1 drives the hydraulic motor and returns oil through port A1. At this time, the manual boat retraction action is performed. When the pressure oil in the accumulator is lower than the switching pressure of the hydraulic directional valve, the high-pressure oil is replenished to the accumulator through the multi-way valve using a manual pump.

[0012] Once the lifeboat is raised to the appropriate position, the high-pressure oil in the accumulator enters the piston rod chamber of the hydraulic cylinder through the second shut-off valve and the two-way balance valve. The hydraulic oil in the rodless chamber of the hydraulic cylinder flows back to the oil tank through the right side of the two-way balance valve and the multi-way valve.

[0013] The oil pump motor unit and the side of the first check valve are connected in parallel with a manual pump branch, and the accumulator is directly connected to the oil tank through the first shut-off valve.

[0014] The return port of the multi-way valve is equipped with a back pressure valve. The return oil pipeline of the multi-way valve is connected to the oil tank in sequence through the back pressure valve and the return oil filter. At least two manual valves are provided between the working plate of the cylinder of the multi-way valve and the two-way balance valve.

[0015] The different working ports of the multi-way valve are connected to the accumulator through the second check valve and the third check valve, respectively. The accumulator is charged by a manual pump or an oil pump motor unit when the hydraulic cylinder is in the retracted state or the extended state, respectively, through the working plate of the multi-way valve cylinder.

[0016] The motor valve assembly is connected to a booster pump, which obtains the gravitational potential energy when the lifeboat is lowered.

[0017] A method of using a hydraulic control system includes the following steps:

[0018] During normal operation, when the boom of the lifeboat lowering device needs to be rotated outward, the high-pressure oil from the oil pump motor unit flows into the rodless chamber of the hydraulic cylinder through the first check valve, the cylinder working plate in the multi-way valve, the first manual valve, and the right side of the two-way balance valve. The hydraulic oil in the piston rod chamber of the hydraulic cylinder flows back to the oil tank through the left side of the two-way balance valve, through the fourth manual valve, the cylinder working plate in the multi-way valve, the back pressure valve, and the return oil filter.

[0019] When the boom of the lifeboat lowering device needs to be moved from the outside to the inside, the high-pressure oil from the oil pump motor unit flows into the piston rod chamber of the hydraulic cylinder through the first check valve, the cylinder working plate in the multi-way valve, the fourth manual valve, and the left side of the two-way balance valve; the hydraulic oil in the rodless chamber of the hydraulic cylinder flows back to the oil tank through the right side of the two-way balance valve through the first manual valve, the cylinder working plate in the multi-way valve, the back pressure valve, and the return oil filter.

[0020] When the lifeboat lowering device electrically lifts the lifeboat raft, the high-pressure oil from the oil pump motor unit passes sequentially through the first one-way valve, the winch working plate in the multi-way valve, the hydraulic reversing valve, and one path of hydraulic oil through the second shuttle valve, the first shuttle valve, the hydraulic reversing valve, and the one-way pressure reducing valve to release the brake; another path of hydraulic oil passes through the one-way balance valve in the winch valve group, enters the B1 port of the hydraulic motor, and then flows through the A1 port of the hydraulic motor, through the winch working plate in the multi-way valve, the back pressure valve, and the return oil filter to flow back to the oil tank.

[0021] When the lifeboat lowering device lowers the lifeboat raft electrically, the high-pressure oil from the oil pump motor unit passes sequentially through the first one-way valve and the winch working plate in the multi-way valve. One path of hydraulic oil passes through the second shuttle valve, the first shuttle valve, the hydraulic directional valve, and the one-way pressure reducing valve to release the brake. The other path of hydraulic oil enters the A1 port of the hydraulic motor, then flows through the B1 port of the hydraulic motor 16, through the one-way balance valve, the hydraulic directional valve, the winch working plate in the multi-way valve, the back pressure valve, and the return oil filter in the winch valve group, and flows back to the oil tank.

[0022] When the oil pressure in the accumulator drops to the hydraulic valve's reversing pressure, the hydraulic valve closes, cutting off the lifeboat winch's operating circuit, and the lifeboat winch stops working. At this point, the accumulator can be manually refilled with fluid using a manual pump until the pressure is restored to the specified value, and then the lifeboat can be manually lifted again, repeating this process.

[0023] When gravity is needed to lower the lifeboat, open the second shut-off valve and the first manual valve. The high-pressure oil in the accumulator enters the rodless chamber of the hydraulic cylinder through the second shut-off valve, the first manual valve, and the right side of the two-way balance valve. The hydraulic oil in the piston rod of the hydraulic cylinder flows back to the oil tank through the left side of the two-way balance valve, the fourth manual valve, the cylinder working plate in the multi-way valve, the back pressure valve, and the return oil filter.

[0024] Once the davit arm of the lifeboat launching device is fully extended overboard, release the handle of the first manual valve, which returns to its original position. Then, open the second manual valve. The high-pressure oil in the accumulator flows through the second shut-off valve and the second manual valve. One path of hydraulic oil flows through the first shuttle valve, the hydraulic directional valve, and the one-way pressure reducing valve to release the brake. The other path of hydraulic oil opens the hydraulic directional valve, allowing the high-pressure oil at port B1 of the hydraulic motor to drive the motor side of the booster pump through the hydraulic directional valve and the speed control valve. At the same time, the oil pump side of the booster pump, driven by the motor side of the booster pump, outputs lower-pressure hydraulic oil into port A1 of the hydraulic motor, thus forming a circuit in the hydraulic motor. The lifeboat launching winch then performs the launching action.

[0025] When manual recovery of the lifeboat is required, open the second shut-off valve and manually control the third manual valve. The high-pressure oil in the accumulator flows through the second shut-off valve, the third manual valve, the hydraulic directional valve, and one hydraulic oil flows through the second shuttle valve, the first shuttle valve, the hydraulic directional valve, and the one-way pressure reducing valve to release the brake. The other hydraulic oil flows through the one-way balance valve in the winch valve group, enters the B1 port of the hydraulic motor, and then flows through the A1 port of the hydraulic motor, through the winch working plate in the multi-way valve 4, the back pressure valve, and the return oil filter to flow back to the oil tank.

[0026] This plan has also been improved in the following four aspects:

[0027] First, the system is equipped with a second and a third check valve, which allows the hydraulic cylinder driving the lifeboat lowering device's davit arm to charge the accumulator both when the lowering device is in the stored position (hydraulic cylinder retracted) and when the lowering device's davit arm is in the fully outboard position (hydraulic cylinder extended).

[0028] Secondly, the system is equipped with a booster pump, which allows the lifeboat lifting winch to use its own gravity to provide power to the booster pump during the gravity lowering of the lifeboat, and to provide unlimited oil replenishment to the gravity lowering circuit of the lifeboat lifting winch, without the need to increase the size of the accumulator for oil replenishment or the auxiliary oil tank for oil replenishment due to the increase in lowering height.

[0029] Third, the system is equipped with a hydraulic directional valve and a third manual valve, which allows the accumulator to be filled with liquid by a manual pump before the lifeboat is lifted by the lifting winch when the lifeboat is manually lifted by the lifting winch.

[0030] During this process, once the oil pressure in the accumulator drops to the hydraulic valve's reversing pressure, the hydraulic valve will close promptly, cutting off the lifeboat winch's operating circuit and stopping the winch's operation. At this point, the accumulator can be manually refilled with fluid using a manual pump until the pressure reaches the specified value, after which the lifeboat can be manually lifted again. This process can be repeated.

[0031] During this operation, the medium and high pressure settings of the hydraulic directional valve play a crucial role in preventing the hydraulic motor from continuing to lose pressurized oil due to leakage under medium and low pressure conditions.

[0032] Fourth, after the lifeboat is manually lifted by the jacking winch, the hydraulic cylinder retracts from high to low pressure as the jacking arm of the lifeboat lowering device moves into the inboard direction. This allows the remaining high-pressure oil in the accumulator to be fully utilized to retract the jacking arm of the lifeboat lowering device to the storage position.

[0033] Beneficial effects:

[0034] The hydraulic control system of this lifeboat lowering device improves the oil replenishment method for the hydraulic motor of the lifeboat lowering winch when it relies on gravity for descent. It can provide unlimited oil replenishment to the gravity lowering circuit of the lifeboat lowering winch without the need to increase the size of the accumulator for oil replenishment or the auxiliary oil tank for oil replenishment. At the same time, it improves the working circuit of the lifeboat lowering winch when manually lifting the lifeboat, thereby increasing the efficiency and speed of manually lifting the lifeboat.

[0035] Furthermore, compared with existing technologies, the addition of a function that directly drives the hydraulic cylinder to retract allows for full utilization of the energy stored in the accumulator, saving rescue time in emergency situations. Attached Figure Description

[0036] Figure 1 It is the hydraulic schematic diagram of the overall control system;

[0037] Figure 2 This is a hydraulic schematic diagram of the connection between the multi-way valve and the hydraulic cylinder.

[0038] Figure 3 This is a schematic diagram of the hydraulic connection between the motor valve assembly and the hydraulic motor.

[0039] in:

[0040] 1. Oil pump motor assembly 2. Manual valve 3. First check valve 4. Multi-way valve 5. First shut-off valve 6. Second check valve 7. Second shut-off valve 8. Third check valve 9. Accumulator 10. Hydraulic cylinder 11. Two-way balance valve 12. First manual valve 13. Booster pump 14. Oil replenishment valve 15. Motor valve assembly 16. Hydraulic motor 17. Second manual valve 18. Hydraulic directional valve 19. Third manual valve 20. Back pressure valve 21. Return oil filter 22. Fourth manual valve 41. Relief valve 42. Cylinder working plate 43. Winch working plate 151. First shuttle valve 152. Second shuttle valve 153. One-way balance valve 154. Hydraulic directional valve 155. Speed ​​control valve 156. One-way pressure reducing valve 157. Hydraulic directional valve. Detailed Implementation

[0041] To enhance understanding of the present invention, the invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining the invention and do not constitute a limitation on the scope of protection of the invention.

[0042] Example 1:

[0043] During normal operation, when the boom of the lifeboat lowering device needs to be rotated outward (hydraulic cylinder extends), the high-pressure oil from the oil pump motor unit 1 passes sequentially through the first one-way valve 3, the cylinder working plate 42 in the multi-way valve 4, the first manual valve 12, the right side of the two-way balance valve 11, and the rodless chamber of the hydraulic cylinder 10; the hydraulic oil in the piston rod of the hydraulic cylinder 10 passes sequentially through the left side of the two-way balance valve 11, the fourth manual valve 22, the cylinder working plate 42 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21 back to the oil tank. When the boom of the lifeboat lowering device needs to be moved from the outside to the inside (hydraulic cylinder retracts), the high-pressure oil from the oil pump motor unit 1 passes sequentially through the first one-way valve 3, the cylinder working plate 42 in the multi-way valve 4, the fourth manual valve 22, the left side of the two-way balance valve 11, and the piston rod chamber of the hydraulic cylinder 10; the hydraulic oil in the rodless chamber of the hydraulic cylinder 10 flows back to the oil tank sequentially through the first manual valve 12, the cylinder working plate 42 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21 via the right side of the two-way balance valve 11. When the lifeboat lowering device electrically lifts the lifeboat raft, the high-pressure oil from the oil pump motor unit 1 passes sequentially through the first one-way valve 3, the winch working plate 43 in the multi-way valve 4, the hydraulic reversing valve 18, and one path of hydraulic oil passes through the second shuttle valve 152, the first shuttle valve 151, the hydraulic reversing valve 157, and the one-way pressure reducing valve 156 to release the brake; the other path of hydraulic oil passes through the one-way balance valve 153 in the winch valve group 15, enters the B1 port of the hydraulic motor 16, and then flows through the A1 port of the hydraulic motor 16, through the winch working plate 43 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21 back to the oil tank.

[0044] When the lifeboat lowering device lowers the lifeboat raft electrically, the high-pressure oil from the oil pump motor unit 1 passes sequentially through the first one-way valve 3 and the winch working plate 43 in the multi-way valve 4. One path of hydraulic oil passes through the second shuttle valve 152, the first shuttle valve 151, the hydraulic reversing valve 157, and the one-way pressure reducing valve 156 to release the brake; the other path of hydraulic oil enters the A1 port of the hydraulic motor 16, and then flows through the B1 port of the hydraulic motor 16, through the one-way balance valve 153 in the winch valve group 15, the hydraulic reversing valve 18, the winch working plate 43 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21 to flow back to the oil tank.

[0045] When gravity-assisted lowering of the lifeboat is required, the second shut-off valve 7 is opened, and the first manual valve 12 is opened remotely via the remote control wire rope on the handle of the first manual valve 12. The high-pressure oil in the accumulator 9 enters the rodless chamber of the hydraulic cylinder 10 through the second shut-off valve 7, the first manual valve 12, and the right side of the two-way balance valve 11. The hydraulic oil in the piston rod of the hydraulic cylinder 10 flows back to the oil tank through the left side of the two-way balance valve 11, through the fourth manual valve 22, the cylinder working plate 42 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21. After the lifeboat lowering device's boom is fully extended overboard, release the handle of the first manual valve 12. The first manual valve 12 returns to its original position. Then, remotely open the second manual valve 17 via the remote control cable on the handle. The high-pressure oil in the accumulator 9 flows through the second shut-off valve 7 and the second manual valve 17. One path of hydraulic oil flows through the first shuttle valve 151, the hydraulic directional valve 157, and the one-way pressure reducing valve 156 to release the brake. The other path of hydraulic oil opens the hydraulic control directional valve 154, causing the high-pressure oil at port B1 of the hydraulic motor 16 to drive the motor side of the booster pump 13 via the hydraulic control directional valve 154 and the speed control valve 155. Simultaneously, the oil pump side of the booster pump 13, driven by the motor side of the booster pump 13, outputs lower-pressure hydraulic oil into port A1 (low-pressure side) of the hydraulic motor 16, forming a circuit in the hydraulic motor 16. The lifeboat raising winch then performs the lifeboat lowering action. As needed, the control handle of the second manual valve 17 can be released at any time, and the lifeboat raising winch's lifeboat lowering action will immediately stop. It should be noted that the displacement on the motor side of the booster pump 13 should be slightly smaller than that on the oil pump side, so that the difference can be used to compensate for the leakage of the hydraulic motor.

[0046] When manual recovery of the lifeboat is required, open the second shut-off valve 7 and manually control the third manual valve 19. The high-pressure oil in the accumulator 9 flows through the second shut-off valve 7, the third manual valve 19, the hydraulic directional valve 18, and one hydraulic oil flows through the second shuttle valve 152, the first shuttle valve 151, the hydraulic directional valve 157, and the one-way pressure reducing valve 156 to release the brake. The other hydraulic oil flows through the one-way balance valve 153 in the winch valve group 15, enters the B1 port of the hydraulic motor 16, and then flows through the A1 port of the hydraulic motor 16, through the winch working plate 43 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21 to return to the oil tank.

[0047] After the lifeboat winch raises the lifeboat to a certain height, the pressure in the accumulator 9 will drop to the opening pressure of the hydraulic directional valve 18. The hydraulic directional valve 18 will then close, and the lifeboat winch will stop raising the lifeboat. This prevents the hydraulic motor from continuing to lose pressurized oil due to leakage when the pressure in the accumulator 9 is insufficient to raise the lifeboat.

[0048] Generally, the opening pressure of the hydraulic valve 18 should be equal to or slightly higher than the pressure required to lift a fully loaded lifeboat. At this point, the third manual valve 19 can be released, and it will reset under the action of the spring. The manual pump 2 can then be operated manually, and the cylinder working plate of the multi-way valve 4 can be placed in the extended cylinder position to charge the accumulator 9 until it reaches the specified value (generally about 1 MPa lower than the system set pressure). Then, the third manual valve 19 can be opened again, and the lifeboat can be lifted again through the accumulator 9 until it reaches the appropriate position. Finally, the third manual valve 19 can be released, and it will reset under the action of the spring. Once the lifeboat / raft is raised to the appropriate position, with the second shut-off valve 7 open, the fourth manual valve 22 is manually controlled. The high-pressure oil in the accumulator 9 enters the piston rod chamber of the hydraulic cylinder 10 through the second shut-off valve 7, the fourth manual valve 22, and the left side of the two-way balance valve 11. The hydraulic oil in the rodless chamber of the hydraulic cylinder 10 flows back to the oil tank through the right side of the two-way balance valve 11, through the first manual valve 12, the cylinder working plate 42 in the multi-way valve 4, the back pressure valve 20, and the return oil filter 21.

[0049] At this point, the davit arm of the lifeboat lowering device moves from the outside to the inside position. If the oil pressure in the accumulator is insufficient, shut-off 7 can be closed, and the accumulator can be filled directly through the hydraulic cylinder working plate of manual pump 2 and multi-way valve 4.

[0050] During the gravity-downward lowering of lifeboats, only the lifeboat's own weight is needed to continuously replenish oil to the gravity-downward circuit of the lifting winch, eliminating the need for an accumulator or auxiliary oil tank for replenishment. When the lifeboat is manually lifted by the lifting winch, improvements to the winch's operating circuit prevent continuous oil loss due to leakage during manual pump suction and pressure build-up, thus improving the efficiency and speed of manual lifting. Furthermore, after the lifeboat is manually lifted, the stored pressure oil in the accumulator is fully utilized to drive the hydraulic cylinder, retracting the lifeboat lowering boom to its storage position, reducing manual labor.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydraulic control system for a lifeboat lowering device, characterized in that, The oil tank, the hydraulic cylinder, the accumulator, the motor valve group and the hydraulic motor are included. The oil tank is provided with an oil pump motor group and an oil pump oil outlet communicated with a multi-way valve inlet through a first check valve. The multi-way valve is provided with an overflow valve and at least two working pieces. The working oil port of the multi-way valve is communicated with the rodless cavity of the hydraulic cylinder through a first hand valve and a two-way balance valve. The accumulator is connected with the motor valve group through a second stop valve and a second hand valve. When the high-pressure oil enters the motor valve group through the second hand valve, one way opens the brake through the motor valve group, and the other way opens the hydraulic control reversing valve.

2. The hydraulic control system of a lifeboat lowering device according to claim 1, characterized in that, The motor B1 port forms pressure oil due to the load effect, drives the booster pump through the hydraulic control reversing valve and the speed regulating valve, and the booster pump outlet supplies oil to the motor A1 port.

3. The hydraulic control system of a lifeboat lowering device according to claim 1, characterized in that, The excess oil flows back to the oil tank through the winch working piece of the multi-way valve and the back pressure valve.

4. The hydraulic control system of a lifeboat lowering device according to claim 1, characterized in that, The accumulator is connected with the motor valve group through a second stop valve, a third hand valve and a first hydraulic reversing valve.

5. The hydraulic control system of a lifeboat lowering device according to claim 1, characterized in that, When the high-pressure oil enters the motor valve group through the third hand valve, one way enters the motor valve group to release the brake, and the other way enters the motor B1 port to drive the hydraulic motor and return oil from the A1 port.

6. A method of using a hydraulic control system for a lifeboat launching arrangement according to any one of claims 1 to 5, wherein the method comprises: When the pressure oil in the accumulator is lower than the switching pressure of the first hydraulic reversing valve, the hand pump supplies high-pressure oil to the accumulator through the multi-way valve. When the lifeboat is lifted to the appropriate position, the high-pressure oil in the accumulator enters the piston rod cavity of the hydraulic cylinder through the second stop valve and the two-way balance valve. The oil pump motor group and the first check valve are connected with the hand pump branch. The return oil port of the multi-way valve is connected with the oil tank through a back pressure valve and an oil return filter. The different working oil ports of the multi-way valve are connected with the accumulator through a second check valve and a third check valve. The motor valve group is connected with the booster pump. The following steps are included: When the lifeboat lowering device needs to be turned out of the side, the high-pressure oil from the oil pump motor group flows into the rodless cavity of the hydraulic cylinder through the first check valve, the cylinder working piece of the multi-way valve, the first hand valve and the right side of the two-way balance valve. The hydraulic oil in the piston rod cavity of the hydraulic cylinder flows back to the oil tank through the left side of the two-way balance valve, the fourth hand valve, the cylinder working piece of the multi-way valve, the back pressure valve and the oil return filter. When the boat arm of the lifeboat launching device needs to be turned into the side from the outside, the high-pressure oil from the oil pump motor group passes through the first check valve, the cylinder working piece in the multi-way valve, the fourth manual valve, the left side of the two-way balance valve, and then flows into the piston rod cavity of the hydraulic cylinder. When the lifeboat launching device electrically lifts the lifeboat raft, the high-pressure oil from the oil pump motor group passes through the first check valve, the winch working piece in the multi-way valve, the first hydraulic reversing valve, one-way hydraulic oil passes through the second shuttle valve, the first shuttle valve, the second hydraulic reversing valve, the one-way pressure reducing valve to release the brake; the other way hydraulic oil passes through the one-way balance valve in the winch valve group, enters the B1 port of the hydraulic motor, then passes through the A1 port of the hydraulic motor, flows through the winch working piece in the multi-way valve, the back pressure valve, and the oil return filter to flow back to the oil tank. When the lifeboat launching device electrically lowers the lifeboat raft, the high-pressure oil from the oil pump motor group passes through the first check valve, the winch working piece in the multi-way valve, one-way hydraulic oil passes through the second shuttle valve, the first shuttle valve, the second hydraulic reversing valve, the one-way pressure reducing valve to release the brake; the other way hydraulic oil enters the A1 port of the hydraulic motor, then passes through the B1 port of the hydraulic motor, flows through the one-way balance valve in the winch valve group, the first hydraulic reversing valve, the winch working piece in the multi-way valve, the back pressure valve, and the oil return filter to flow back to the oil tank.

7. The method of using a hydraulic control system of claim 6, wherein, The steps include: When the lifeboat raft needs to be gravity lowered, the second stop valve is opened, the first manual valve is opened, the high-pressure oil in the accumulator passes through the second stop valve, the first manual valve, the right side of the two-way balance valve, enters the rodless cavity of the hydraulic cylinder, the hydraulic oil in the hydraulic cylinder piston rod passes through the left side of the two-way balance valve, then passes through the fourth manual valve, the cylinder working piece in the multi-way valve, the back pressure valve, and the oil return filter to flow back to the oil tank. When the boat arm of the lifeboat launching device is completely turned out to the side, the handle of the first manual valve is released, the first manual valve is reset to the original position, then the second manual valve is opened, the high-pressure oil in the accumulator passes through the second stop valve, the second manual valve, one-way hydraulic oil passes through the first shuttle valve, the second hydraulic reversing valve, the one-way pressure reducing valve to release the brake; the other way hydraulic oil opens the hydraulic control reversing valve, the high-pressure oil in the B1 port of the hydraulic motor passes through the hydraulic control reversing valve, the speed regulating valve drives the motor side of the booster pump, at the same time the oil pump side of the booster pump outputs lower pressure hydraulic oil under the drive of the motor side of the booster pump, enters the A1 port of the hydraulic motor, forms a loop of the hydraulic motor, and the boat winch performs the boat launching action; When the lifeboat raft needs to be manually recovered, the second stop valve is opened, the third manual valve is manually controlled, the high-pressure oil in the accumulator passes through the second stop valve, the third manual valve, the first hydraulic reversing valve, one-way hydraulic oil passes through the second shuttle valve, the first shuttle valve, the second hydraulic reversing valve, the one-way pressure reducing valve to release the brake; the other way hydraulic oil passes through the one-way balance valve in the winch valve group, enters the B1 port of the hydraulic motor, then passes through the A1 port of the hydraulic motor, flows through the winch working piece in the multi-way valve 4, the back pressure valve, and the oil return filter to flow back to the oil tank.

8. The method of using a hydraulic control system of claim 7, wherein, The steps include: When the oil pressure in the accumulator drops to the first hydraulic directional valve switching pressure, the first hydraulic directional valve is closed, the launching winch working circuit is cut off, and the launching winch stops working; at this time, the accumulator can be filled with liquid again through the manual pump, and after the pressure is filled to the specified value, the life raft is manually lifted again, and so on.

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