A hydraulic control system for a lifting device

Abstract

A hydraulic control system for a lifting device. The lifting device includes a leg, a fixed collar beam and a movable collar beam sleeved outside the leg. The fixed collar beam and the movable collar beam are connected by a lifting oil cylinder. A fixed collar beam pin matching with the pin hole on the leg and a fixed collar beam pin oil cylinder for driving the fixed collar beam pin are arranged on the fixed collar beam. A movable collar beam pin matching with the pin hole on the leg and a movable collar beam pin oil cylinder for driving the movable collar beam pin are arranged on the movable collar beam. A pile fixing oil cylinder is further arranged on the outer periphery of the leg. The hydraulic control system includes a pile fixing control system, a pin control system and a lifting control system. The pile fixing control system is used to control the pile fixing oil cylinder. The pin control system is used to control the fixed collar beam pin oil cylinder and the movable collar beam pin oil cylinder. The lifting control system is used to control the lifting oil cylinder. A proportional overflow valve and an inverse proportional overflow valve are arranged on the return oil pipeline of the lifting control system. In this design, the structure of the hydraulic control system is simple, safe and has low heat generation.

Description

Technical Field

[0001] The present invention relates to a hydraulic control system, and particularly to a hydraulic control system for a lifting device, specifically applicable to the hydraulic control of a lifting platform. Background Art

[0002] In the field of offshore engineering technology, self-elevating offshore platforms are extremely widely used. Such offshore platforms usually need to use a lifting system to drive the platform to lift along the axial direction of the pile legs. The lifting of the offshore platform is usually controlled by a hydraulic lifting system. Existing lifting platforms usually have a moving collar beam and a fixed collar beam arranged on the pile legs. The moving collar beam and the fixed collar beam are connected by lifting cylinders, and the fixed collar beam is mechanically connected to the offshore platform. Moreover, pin assemblies inserted into the pile legs are arranged on both the moving collar beam and the fixed collar beam. Through the telescopic movement of the lifting cylinders and the insertion and extraction movements of the pin assemblies, the lifting movement of the offshore platform along the axial direction of the pile legs is completed.

[0003] However, the lifting platform has multiple operating conditions such as platform lifting, pile leg lifting, collar beam lifting, pile pulling, and preloading. The backpressure required at the oil return port of the system is different under different conditions. Therefore, the existing hydraulic control system for a lifting platform usually adopts a multi-stage relief valve. The multi-stage relief valve at the main pump outlet provides safety protection for the system under different conditions. And since the backpressure value during platform descent is designed according to the platform's rated load, and in most cases during platform operation, the load is less than the rated load, usually the system oil return backpressure is greater than the platform load during platform operation, which easily causes a large amount of heat generation in the system during platform descent. Also, when the existing lifting platform stands and is towed, in order to prevent the pile legs from shaking under the action of wind and waves, it is necessary to manually install wedges between the pile legs and the pile fixing chambers, which is troublesome to operate and wastes manpower. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems in the prior art that the hydraulic control system of the lifting platform has a large amount of heat generation, and that it is necessary to manually install wedges between the pile legs and the pile fixing chambers when the lifting platform stands and is towed, and to provide a hydraulic control system for a lifting device that can reduce the heat generation of the hydraulic control system of the lifting platform and has a pile fixing function.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A hydraulic control system for a lifting device, the lifting device includes pile legs and a fixed collar beam and a moving collar beam sleeved outside the pile legs from top to bottom. The fixed collar beam and the moving collar beam are connected by lifting cylinders. A fixed collar beam pin matching with the pin holes on the pile legs and a fixed collar beam pin cylinder for driving the fixed collar beam pin are arranged on the fixed collar beam. A moving collar beam pin matching with the pin holes on the pile legs and a moving collar beam pin cylinder for driving the moving collar beam pin are arranged on the moving collar beam;

[0007] The hydraulic control system includes an oil tank, a pin control system, and a lifting control system. The pin control system includes a main pump and a pin cylinder reversing valve. The inlet of the main pump is connected to the oil tank, and the outlet of the main pump is simultaneously connected to the rod chamber of the fixed ring beam pin cylinder, the rod chamber of the moving ring beam pin cylinder, and the inlet of the pin cylinder reversing valve. The outlet of the pin cylinder reversing valve is connected to the oil tank. The first working oil port and the second working oil port of the pin cylinder reversing valve are respectively connected to the rodless chamber of the fixed ring beam pin cylinder and the rodless chamber of the moving ring beam pin cylinder;

[0008] The lifting control system includes a lifting pump, a lifting cylinder reversing valve, and an inverse proportional overflow valve. The inlet of the lifting pump is connected to the oil tank, and the outlet of the lifting pump is connected to the inlet of the lifting cylinder reversing valve. The outlet of the lifting cylinder reversing valve is connected to the inlet of the inverse proportional overflow valve, and the outlet of the inverse proportional overflow valve is connected to the oil tank. The first working oil port of the lifting cylinder reversing valve is connected to the rod chamber of the lifting cylinder, and the second working oil port of the lifting cylinder reversing valve is connected to the rodless chamber of the lifting cylinder.

[0009] The pin control system further includes an electromagnetic overflow valve. The inlet of the electromagnetic overflow valve is connected to the outlet of the main pump, and the outlet of the electromagnetic overflow valve is connected to the oil tank;

[0010] The lifting control system further includes a direct proportional overflow valve. The inlet of the direct proportional overflow valve is connected to the outlet of the lifting pump, and the outlet of the direct proportional overflow valve is connected to the oil tank.

[0011] A first one-way valve is provided on the oil path between the outlet of the main pump and the inlet of the pin cylinder reversing valve. The inlet of the first one-way valve is simultaneously connected to the outlet of the main pump and the inlet of the electromagnetic overflow valve, and the outlet of the first one-way valve is connected to the inlet of the pin cylinder reversing valve;

[0012] A second one-way valve is provided on the oil path between the outlet of the lifting pump and the inlet of the lifting cylinder reversing valve. The inlet of the second one-way valve is simultaneously connected to the outlet of the lifting pump and the inlet of the direct proportional overflow valve, and the outlet of the second one-way valve is connected to the inlet of the lifting cylinder reversing valve.

[0013] The lifting device further includes a plurality of upper fixed pile cylinders and a plurality of lower fixed pile cylinders. The plurality of upper fixed pile cylinders are evenly arranged along the outer circumference of the pile leg, and the outer end of the piston rod of the upper fixed pile cylinder is in limit fit with the upper end of the pile leg. The plurality of lower fixed pile cylinders are evenly arranged along the outer circumference of the pile leg, and the outer end of the piston rod of the lower fixed pile cylinder is in limit fit with the lower end of the pile leg;

[0014] The hydraulic control system further includes a pile fixing control system, which includes a first pile fixing oil cylinder reversing valve and a second pile fixing oil cylinder reversing valve. The oil inlets of the first pile fixing oil cylinder reversing valve and the second pile fixing oil cylinder reversing valve are simultaneously connected to the oil inlet of the pin cylinder reversing valve. The oil outlets of the first pile fixing oil cylinder reversing valve and the second pile fixing oil cylinder reversing valve are connected to the oil tank. The first working oil port of the first pile fixing oil cylinder reversing valve is simultaneously connected to the rodless cavities of multiple upper-layer pile fixing oil cylinders, and the second working oil port of the first pile fixing oil cylinder reversing valve is simultaneously connected to the rod cavities of multiple upper-layer pile fixing oil cylinders. The first working oil port of the second pile fixing oil cylinder reversing valve is simultaneously connected to the rodless cavities of multiple lower-layer pile fixing oil cylinders, and the second working oil port of the second pile fixing oil cylinder reversing valve is simultaneously connected to the rod cavities of multiple lower-layer pile fixing oil cylinders.

[0015] The number of the upper-layer pile fixing oil cylinders is 4, and the number of the lower-layer pile fixing oil cylinders is 4.

[0016] A first hydraulic control check valve is arranged on the pipeline between the first working oil port of the first pile fixing oil cylinder reversing valve and the rodless cavity of the upper-layer pile fixing oil cylinder. The oil inlet of the first hydraulic control check valve is connected to the first working oil port of the first pile fixing oil cylinder reversing valve, the oil outlet of the first hydraulic control check valve is simultaneously connected to the rodless cavities of multiple upper-layer pile fixing oil cylinders, and the control port of the first hydraulic control check valve is connected to the second working oil port of the first pile fixing oil cylinder reversing valve;

[0017] A second hydraulic control check valve is arranged on the pipeline between the first working oil port of the second pile fixing oil cylinder reversing valve and the rodless cavity of the lower-layer pile fixing oil cylinder. The oil inlet of the second hydraulic control check valve is connected to the first working oil port of the second pile fixing oil cylinder reversing valve, the oil outlet of the second hydraulic control check valve is simultaneously connected to the rodless cavities of multiple lower-layer pile fixing oil cylinders, and the control port of the second hydraulic control check valve is connected to the second working oil port of the second pile fixing oil cylinder reversing valve.

[0018] The pile fixing control system further includes a first relief valve and a second relief valve. The oil inlet of the first relief valve is connected to the oil outlet of the first hydraulic control check valve, and the oil outlet of the first relief valve is connected to the oil tank;

[0019] The oil inlet of the second relief valve is connected to the oil outlet of the second hydraulic control check valve, and the oil outlet of the second relief valve is connected to the oil tank.

[0020] The first pile fixing oil cylinder reversing valve, the second pile fixing oil cylinder reversing valve, the pin cylinder reversing valve and the lifting cylinder reversing valve are all three-position four-way electromagnetic reversing valves.

[0021] The fixed ring beam pin cylinder and the moving ring beam pin cylinder are both differential hydraulic cylinders.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. In the pile fixing and pin control system of the hydraulic control system of a lifting device according to the present invention, the piston rod of the upper pile fixing oil cylinder can be controlled to extend and retract by the first pile fixing oil cylinder reversing valve, and the piston rod of the lower pile fixing oil cylinder can be controlled to extend and retract by the second pile fixing oil cylinder reversing valve. Since the outer end of the piston rod of the upper pile fixing oil cylinder is in limit fit with the upper end of the pile leg, and the outer end of the piston rod of the lower pile fixing oil cylinder is in limit fit with the lower end of the pile leg, the attitude of the pile leg can be adjusted by controlling the extension and retraction of the piston rod of the pile fixing oil cylinder to keep it vertical. Moreover, when the platform is in towage and standing states, the pile fixing oil cylinder can also prevent the pile leg from swaying under the action of wind and waves. At the same time, in this design, the pile fixing oil cylinder is divided into an upper pile fixing oil cylinder and a lower pile fixing oil cylinder, and the pile fixing oil cylinders arranged up and down can make the pile leg more stable. Therefore, the pile fixing oil cylinder in this design can make the pile leg more stable and prevent the pile leg from swaying under the action of wind and waves in the towage and standing states of the platform.

[0024] 2. The fixed ring beam pin oil cylinder and the moving ring beam pin oil cylinder in the hydraulic control system of a lifting device according to the present invention are both differential hydraulic cylinders. The first working oil port and the second working oil port of the pin oil cylinder reversing valve are respectively communicated with the rodless cavity of the fixed ring beam pin oil cylinder and the rodless cavity of the moving ring beam pin oil cylinder. The rod cavity of the fixed ring beam pin oil cylinder and the rod cavity of the moving ring beam pin oil cylinder are both communicated with the oil outlet of the main pump. After the rodless cavity of the fixed ring beam pin oil cylinder or the moving ring beam pin oil cylinder is communicated with the oil outlet of the main pump through the pin oil cylinder reversing valve, due to the different cross-sectional areas on both sides of the piston of the differential hydraulic cylinder, the piston rod of the pin oil cylinder will extend and push the pin into the pin hole on the pile leg. And there is always one of the ring beam pin oil cylinder and the moving ring beam pin oil cylinder whose rodless cavity is communicated with the oil outlet of the main pump, ensuring that a set of pins is inserted into the pin hole on the pile leg at any time to ensure the safety of the platform. Therefore, in this design, the piston rod of the pin oil cylinder drives the pin to extend and retract, enabling the pin to be inserted into or withdrawn from the pin hole on the pile leg, facilitating the lifting of the platform and the pile leg; at the same time, ensuring that at least one ring beam is fixed on the pile leg at any time to ensure the safety of the platform.

[0025] 3. A proportional overflow valve is arranged on the pipeline between the oil outlet of the lifting oil cylinder reversing valve and the oil tank in the hydraulic control system of a lifting device according to the present invention. The oil inlet of the proportional overflow valve is communicated with the oil outlet of the lifting oil cylinder reversing valve, and the oil outlet of the proportional overflow valve is communicated with the oil tank. The proportional overflow valve can perform stepless pressure regulation on the system back pressure according to the load size under different working conditions, reducing the heat generation of the system; at the same time, when the lifting system fails to work, there is no signal input to the proportional overflow valve. At this time, the proportional overflow valve can provide a relatively large back pressure to ensure the safety of the platform. Therefore, in this design, the proportional overflow valve can perform stepless pressure regulation on the system back pressure according to the load size and can also provide a relatively large back pressure when the system fails, ensuring the safety of the marine lifting platform.

[0026] 4. In the hydraulic control system of a lifting device according to the present invention, a pilot-operated check valve is provided on the pipeline between the first working oil port of the first fixed pile cylinder reversing valve and the rodless cavity of the upper fixed pile cylinder. Similarly, a pilot-operated check valve is provided on the pipeline between the rodless cavity of the lower fixed pile cylinder and the first working oil port of the second fixed pile cylinder reversing valve. During pile fixing, both the upper fixed pile cylinder and the lower fixed pile cylinder extend. Subsequently, the first fixed pile cylinder reversing valve and the second fixed pile cylinder reversing valve lose power, and closed cavities are formed between the rodless cavity of the upper fixed pile cylinder and the first pilot-operated check valve, and between the rodless cavity of the lower fixed pile cylinder and the second pilot-operated check valve, preventing the fixed pile cylinders from displacing during pile fixing. Therefore, in this design, the first pilot-operated check valve and the second pilot-operated check valve can prevent the fixed pile cylinders from displacing during pile fixing. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of the present invention.

[0028] Figure 2 is a schematic structural diagram of the lifting device.

[0029] Figure 3 is a schematic diagram of the upper fixed pile cylinder and the lower fixed pile cylinder.

[0030] Figure 4 is a schematic diagram of the cooperation between the upper fixed pile cylinder and the pile leg.

[0031] Figure 5 is a schematic diagram of the cooperation between the lower fixed pile cylinder and the pile leg.

[0032] In the figure: fixed ring beam pin cylinder 1, moving ring beam pin cylinder 2, lifting cylinder 3, main pump 41, pin cylinder reversing valve 42, electromagnetic overflow valve 43, first check valve 44, lifting pump 51, lifting cylinder reversing valve 52, inverse proportional overflow valve 53, proportional overflow valve 54, second check valve 55, upper fixed pile cylinder 6, lower fixed pile cylinder 7, first fixed pile cylinder reversing valve 81, second fixed pile cylinder reversing valve 82, first pilot-operated check valve 83, second pilot-operated check valve 84, first overflow valve 85, second overflow valve 86, pile leg 10, fixed ring beam 20, moving ring beam 30, fuel tank 40, motor 9. Detailed Description of the Invention

[0033] The present invention will be further described in detail below in conjunction with the description of the drawings and the detailed implementation manner.

[0034] See Figures 1 to 5 , a fixed ring beam 20 and a moving ring beam 30 are sleeved outside the pile leg 10, as Figure 2As shown, the fixed ring beam 20 and the moving ring beam 30 are connected by a lifting oil cylinder 3. When the piston rod of the lifting oil cylinder 3 extends, the fixed ring beam 20 and the moving ring beam 30 move away from each other. When the piston rod of the lifting oil cylinder 3 retracts, the fixed ring beam 20 and the moving ring beam 30 move closer to each other.

[0035] A fixed ring beam pin that mates with the pin holes on the leg 10 is provided on the fixed ring beam 20. The fixed ring beam pin is in transmission cooperation with the fixed ring beam pin oil cylinder 1. The piston rod of the fixed ring beam pin oil cylinder 1 can push the fixed ring beam pin in a direction perpendicular to the axial direction of the leg 10, so that the fixed ring beam pin is inserted into the pin hole on the leg 10 or pulled out from the pin hole on the leg 10.

[0036] A moving ring beam pin that mates with the pin holes on the leg 10 is provided on the moving ring beam 30. The moving ring beam pin is in transmission cooperation with the moving ring beam pin oil cylinder 2. The piston rod of the moving ring beam pin oil cylinder 2 can push the moving ring beam pin in a direction perpendicular to the axial direction of the leg 10, so that the moving ring beam pin is inserted into the pin hole on the leg 10 or pulled out from the pin hole on the leg 10.

[0037] As Figure 1 shown, the hydraulic control system includes an oil tank 40, a pin control system, and a lifting control system. The pin control system includes a main pump 41 and a pin oil cylinder reversing valve 42. The inlet of the main pump 41 is connected to the oil tank 40. The outlet of the main pump 41 is simultaneously connected to the rod chamber of the fixed ring beam pin oil cylinder 1, the rod chamber of the moving ring beam pin oil cylinder 2, and the inlet of the pin oil cylinder reversing valve 42. The outlet of the pin oil cylinder reversing valve 42 is connected to the oil tank 40. The first working oil port and the second working oil port of the pin oil cylinder reversing valve 42 are respectively connected to the rodless chamber of the fixed ring beam pin oil cylinder 1 and the rodless chamber of the moving ring beam pin oil cylinder 2.

[0038] As Figure 1 shown, the pin oil cylinder reversing valve 42 is a three-position four-way reversing valve. When it loses power and is in the middle position, its inlet, two working oil ports are interconnected, and its outlet is not connected to the other three oil ports. At this time, its inlet and two working oil ports are connected and are both connected to the outlet of the main pump 41. At this time, since the rod chamber and the rodless chamber of the fixed ring beam pin oil cylinder 1 and the rod chamber and the rodless chamber of the moving ring beam pin oil cylinder 2 are all connected to the outlet of the main pump 41, and since the fixed ring beam pin oil cylinder 1 and the moving ring beam pin oil cylinder 2 are both differential hydraulic cylinders, and the piston in the differential hydraulic cylinder has a larger force-bearing surface in the rodless chamber, the force on the rodless chamber side of the piston is larger. At this time, the piston rods of the fixed ring beam pin oil cylinder 1 and the moving ring beam pin oil cylinder 2 both extend, so that the corresponding ring beam pins are inserted into the pin holes on the leg 10 to ensure the safety of the platform.

[0039] The lifting control system includes a lift pump 51, a lift cylinder reversing valve 52, and an inverse proportional overflow valve 53. The inlet of the lift pump 51 is connected to the fuel tank 40, the outlet of the lift pump 51 is connected to the inlet of the lift cylinder reversing valve 52, the outlet of the lift cylinder reversing valve 52 is connected to the inlet of the inverse proportional overflow valve 53, and the outlet of the inverse proportional overflow valve 53 is connected to the fuel tank 40. The first working oil port of the lift cylinder reversing valve 52 is connected to the rod chamber of the lifting cylinder 3, and the second working oil port of the lift cylinder reversing valve 52 is connected to the rodless chamber of the lifting cylinder 3. As Figure 1 shown, the lift cylinder reversing valve 52 is a three-position four-way reversing valve. When it is in the middle position, its inlet, outlet, and two working oil ports are not connected to each other. At this time, the piston rod of the lifting cylinder 3 is stationary.

[0040] Since the lifting platform has various different working conditions, the inverse proportional overflow valve 53 can adjust the back pressure of the oil return of the hydraulic lifting system under different working conditions, reducing the heat generation of the system. At the same time, when the lifting system fails to work, there is no control current input to the inverse proportional overflow valve 53. Due to the self-generating characteristics of the inverse proportional overflow valve, the inverse proportional overflow valve 53 will provide a relatively large back pressure when there is no control current input, ensuring the safety of the lifting platform.

[0041] The pin control system further includes an electromagnetic overflow valve 43. The inlet of the electromagnetic overflow valve 43 is connected to the outlet of the main pump 41, and the outlet of the electromagnetic overflow valve 43 is connected to the fuel tank 40. The electromagnetic overflow valve 43 provides safety pressure protection for the pile fixing and pin control system.

[0042] The lifting control system further includes a direct proportional overflow valve 54. The inlet of the direct proportional overflow valve 54 is connected to the outlet of the lift pump 51, and the outlet of the direct proportional overflow valve 54 is connected to the fuel tank 40. The direct proportional overflow valve 54 provides safety pressure protection for the lifting control system.

[0043] A first check valve 44 is provided on the oil path between the outlet of the main pump 41 and the inlet of the pin cylinder reversing valve 42. The inlet of the first check valve 44 is simultaneously connected to the outlet of the main pump 41 and the inlet of the electromagnetic overflow valve 43, and the outlet of the first check valve 44 is connected to the inlet of the pin cylinder reversing valve 42;

[0044] A second check valve 55 is provided on the oil path between the outlet of the lift pump 51 and the inlet of the lift cylinder reversing valve 52. The inlet of the second check valve 55 is simultaneously connected to the outlet of the lift pump 51 and the inlet of the direct proportional overflow valve 54, and the outlet of the second check valve 55 is connected to the inlet of the lift cylinder reversing valve 52. The first check valve 44 and the second check valve 55 prevent the hydraulic oil from flowing back into the main pump 41 or the lift pump 51.

[0045] like Figures 2 to 5 As shown, the lifting device further includes a plurality of upper pile fixing cylinders 6 and a plurality of lower pile fixing cylinders 7. The plurality of upper pile fixing cylinders 6 are evenly arranged along the outer circumference of the pile leg 10. The outer ends of the piston rods of the upper pile fixing cylinders 6 are limitedly matched with the upper ends of the pile legs 10, and the outer ends of the piston rods of the lower pile fixing cylinders 7 are limitedly matched with the lower ends of the pile legs 10. When fixing the pile, the piston rods of the upper pile fixing cylinders 6 and the lower pile fixing cylinders 7 extend out to support the pile legs to make them stand upright, while preventing the pile legs from shaking under the action of wind and waves.

[0046] like Figure 1 As shown, the hydraulic control system also includes a pile control system, which includes a first pile cylinder reversing valve 81 and a second pile cylinder reversing valve 82, the oil inlet of the first pile cylinder reversing valve 81 and the oil inlet of the second pile cylinder reversing valve 82 are simultaneously connected to the oil inlet of the latch cylinder reversing valve 42, the oil outlet of the first pile cylinder reversing valve 81 and the oil outlet of the second pile cylinder reversing valve 82 are connected to the oil tank 40, the first working oil port of the first pile cylinder reversing valve 81 is simultaneously connected to the rodless chambers of multiple upper pile cylinders 6, the second working oil port of the first pile cylinder reversing valve 81 is simultaneously connected to the rod chambers of multiple upper pile cylinders 6, the first working oil port of the second pile cylinder reversing valve 82 is simultaneously connected to the rodless chambers of multiple lower pile cylinders 7, and the second working oil port of the second pile cylinder reversing valve 82 is simultaneously connected to the rod chambers of multiple lower pile cylinders 7.

[0047] like Figure 1 As shown, the first pile-fixing cylinder reversing valve 81 is a three-position four-way reversing valve. When it is in the middle position when it loses power, its oil outlet is interconnected with the two working oil ports; the second pile-fixing cylinder reversing valve 82 is a three-position four-way reversing valve. When it is in the middle position when it loses power, its oil outlet is interconnected with the two working oil ports.

[0048] The number of the upper pile-fixing cylinders 6 is 4, and the number of the lower pile-fixing cylinders 7 is 4. The upper pile-fixing cylinders 6 and the lower pile-fixing cylinders 7 are evenly arranged along the outer periphery of the pile legs 10, and the pile legs are evenly stressed in the horizontal direction. The upper pile-fixing cylinders 6 are located above the lower pile-fixing cylinders 7, and the arrangement of the pile-fixing cylinders is divided into the upper pile-fixing cylinders 6 and the lower pile-fixing cylinders 7, which makes the pile legs better to keep upright without tilting.

[0049] like Figure 1As shown, a first pilot-operated check valve 83 is provided on the pipeline between the first working oil port of the first fixed pile oil cylinder reversing valve 81 and the rodless cavity of the upper fixed pile oil cylinder 6. The oil inlet of the first pilot-operated check valve 83 is communicated with the first working oil port of the first fixed pile oil cylinder reversing valve 81. The oil outlet of the first pilot-operated check valve 83 is simultaneously communicated with the rodless cavities of multiple upper fixed pile oil cylinders 6. The control port of the first pilot-operated check valve 83 is communicated with the second working oil port of the first fixed pile oil cylinder reversing valve 81;

[0050] A second pilot-operated check valve 84 is provided on the pipeline between the first working oil port of the second fixed pile oil cylinder reversing valve 82 and the rodless cavity of the lower fixed pile oil cylinder 7. The oil inlet of the second pilot-operated check valve 84 is communicated with the first working oil port of the second fixed pile oil cylinder reversing valve 82. The oil outlet of the second pilot-operated check valve 84 is simultaneously communicated with the rodless cavities of multiple lower fixed pile oil cylinders 7. The control port of the second pilot-operated check valve 84 is communicated with the second working oil port of the second fixed pile oil cylinder reversing valve 82.

[0051] During pile fixing, the piston rods of the upper fixed pile oil cylinder 6 and the lower fixed pile oil cylinder 7 both extend. Subsequently, the two three-position four-way reversing valves, namely the first fixed pile oil cylinder reversing valve 81 and the second fixed pile oil cylinder reversing valve 82, lose power and return to the middle position. As Figure 1 shown, when the first fixed pile oil cylinder reversing valve 81 is in the middle position, its two working oil ports are both communicated with the fuel tank. At this time, a closed cavity is formed between the four upper fixed pile oil cylinders 6 and the first pilot-operated check valve 83 to prevent the upper fixed pile oil cylinder 6 from generating displacement during pile fixing. Similarly, when the second fixed pile oil cylinder reversing valve 82 is in the middle position, its two working oil ports are both communicated with the fuel tank. At this time, a closed cavity is formed between the four lower fixed pile oil cylinders 7 and the second pilot-operated check valve 84 to prevent the lower fixed pile oil cylinder 7 from generating displacement during pile fixing.

[0052] The pile fixing control system further includes a first relief valve 85 and a second relief valve 86. The oil inlet of the first relief valve 85 is communicated with the oil outlet of the first pilot-operated check valve 83. The oil outlet of the first relief valve 85 is communicated with the fuel tank 40;

[0053] The oil inlet of the second relief valve 86 is communicated with the oil outlet of the second pilot-operated check valve 84. The oil outlet of the second relief valve 86 is communicated with the fuel tank 40.

[0054] The first relief valve 85 and the second relief valve 86 are used to provide pressure protection for the upper fixed pile oil cylinder 6 and the lower fixed pile oil cylinder 7 during pile fixing, to avoid damage to the oil cylinders when the force of the pile leg shaking is too large.

[0055] The principle of the present invention is described as follows:

[0056] The fixed ring beam is mechanically connected to the marine lifting platform. When the lifting device is in the towing or standing working condition:

[0057] When the lifting device is towing or standing, the pile fixing cylinder needs to be extended. At this time, the motor 9 drives the main pump 41 to rotate, the electromagnetic overflow valve 43 is energized, the electromagnet DT1 of the first pile fixing cylinder reversing valve 81 is not energized, the electromagnet DT2 is energized, the first pile fixing cylinder reversing valve 81 works in the right position, the electromagnet DT3 of the second pile fixing cylinder reversing valve 82 is not energized, the electromagnet DT4 is energized, and the second pile fixing cylinder reversing valve 82 works in the right position. At this time, the pressure oil at the oil outlet of the driving main pump 41 flows into the rodless cavity of the upper pile fixing cylinder 6 and the rodless cavity of the lower pile fixing cylinder 7, so that the piston rods of the upper pile fixing cylinder 6 and the lower pile fixing cylinder 7 are extended, and then the piston rods of the pile fixing cylinders are supported against the pile legs.

[0058] When the pile fixing pressure reaches a certain value (that is, when the pile fixing force reaches a certain value), the electromagnet DT2 loses power, the first pile fixing cylinder reversing valve 81 switches to the middle position, the electromagnet DT4 loses power, the second pile fixing cylinder reversing valve 82 switches to the middle position, and a closed cavity is formed between the rodless cavity of the upper pile fixing cylinder 6 and the hydraulically controlled one-way valve, and between the rodless cavity of the lower pile fixing cylinder 7 and the hydraulically controlled one-way valve, and the piston of the pile fixing cylinder is displaced.

[0059] When the platform needs to leave the towing or standing state and perform lifting and lowering actions, the pile cylinder needs to be retracted. At this time, the motor 9 drives the main pump 41 to rotate, the electromagnetic overflow valve 43 is energized, the electromagnet DT1 of the first pile cylinder reversing valve 81 and the electromagnet DT3 of the second pile cylinder reversing valve 82 are energized, the first pile cylinder reversing valve 81 and the second pile cylinder reversing valve 82 are both switched to the left position, driving the pressure oil at the oil outlet of the main pump 41 to enter the rod chamber of the upper pile cylinder 6 and the rod chamber of the lower pile cylinder 7. At the same time, there is pressure at the control end of the hydraulic control one-way valve, the hydraulic control one-way valve is turned on, and the hydraulic oil in the rodless chamber of the upper pile cylinder 6 and the rodless chamber of the lower pile cylinder 7 flows back to the oil tank through the hydraulic control one-way valve, and the piston rod of the pile cylinder is retracted.

[0060] When the lifting device is in the platform descending condition:

[0061] When the lifting device is in the platform descending condition, the pile legs are fixed and the pile fixing cylinders are retracted, and the marine lifting platform mechanically connected to the fixed ring beam descends along the axial direction of the pile legs.

[0062] The working process of the marine lifting platform descending along the axial direction of the leg is as follows: The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are energized. The electromagnets DT5 of the pin cylinder reversing valve 42 are energized and the electromagnet DT6 is not energized. The pin cylinder reversing valve 42 works in the left position. The pressure oil at the outlet of the main pump 41 enters the rod chamber of the fixed ring beam pin cylinder 1 and both chambers of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts under the action of the pressure oil in its rod chamber, and the fixed ring beam pin is pulled out from the pin hole on the leg. The pressure in the rod chamber and the non-rod chamber of the moving ring beam pin cylinder 2 is the same, and the piston rod of the moving ring beam pin cylinder 2 extends outwards, and the moving ring beam pin is inserted into the pin hole on the leg. Subsequently, the electromagnets DT8 of the lifting cylinder reversing valve 52 are energized and the electromagnet DT7 is not energized. The lifting cylinder reversing valve 52 works in the right position. The pressure oil at the outlet of the lifting pump 51 enters the rod chamber of the lifting cylinder 3 through the second one-way valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 retracts, and the oil in the non-rod chamber of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. When the platform is in the descending condition, the fixed ring beam 20 and the entire marine lifting platform both descend. Since the system actively exerts less force when the marine lifting platform descends along the axial direction of the leg, and due to the relatively large mass of the marine lifting platform, at this time, a relatively small control current signal is given to the proportional overflow valve 54 to make the system safety pressure relatively small. At the same time, the control current of the inverse proportional overflow valve 53 is adjusted according to the load of the platform, so that the system oil return back pressure can be balanced with the platform load, ensuring the safe descent of the platform, better protecting the system, and avoiding excessive system heating caused by too large oil return back pressure, resulting in energy loss.

[0063] After the piston rod of the lifting cylinder 3 is completely retracted, the electromagnet DT6 of the pin cylinder reversing valve 42 is energized and the electromagnet DT5 is de-energized. The pin cylinder reversing valve 42 switches to the right position. At this time, the piston rod of the fixed ring beam pin cylinder 1 extends, the fixed ring beam pin is inserted into the pin hole on the leg 10, the piston rod of the moving ring beam pin cylinder 2 retracts, and the fixed ring beam pin is pulled out from the pin hole on the leg 10. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is de-energized and the electromagnet DT7 is energized. The lifting cylinder reversing valve 52 switches to the left position. The pressure oil at the outlet of the lifting pump 51 enters the non-rod chamber of the lifting cylinder 3. The piston rod of the lifting cylinder 3 extends, and the oil in the rod chamber of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. The moving ring beam 30 descends. Since the mass of the moving ring beam 30 is relatively small, the system actively exerts very little force and the back pressure is relatively small. At this time, a relatively small control current signal is given to the proportional overflow valve 54 and a relatively large current signal is given to the inverse proportional overflow valve 53 to make the system oil return back pressure relatively small and reduce the system heat generation.

[0064] Repeatedly performing the above actions multiple times can achieve the stable descent of the marine platform.

[0065] When the lifting device is in the platform ascending working condition:

[0066] When the lifting device is in the platform ascending working condition, the pile legs are fixed and the pile fixing oil cylinders retract, and the marine lifting platform mechanically connected to the fixed ring beam climbs along the axial direction of the pile legs.

[0067] The working process of the marine lifting platform climbing along the axial direction of the pile legs is as follows: The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are powered on. The electromagnet DT5 of the pin cylinder reversing valve 42 is powered on, and the electromagnet DT6 is not powered on. The pin cylinder reversing valve 42 works in the left position. At this time, the pressure oil at the outlet of the main pump 41 enters the rodless cavity of the fixed ring beam pin cylinder 1 and both cavities of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts under the action of the pressure oil in its rodless cavity, and the fixed ring beam pin is pulled out from the pin hole on the pile leg. The pressures in the rodless cavity and the rod cavity of the moving ring beam pin cylinder 2 are the same. Since the moving ring beam pin cylinder 2 is a differential hydraulic cylinder, the force-bearing area of its piston in the rodless cavity is larger than that in the rod cavity, and the piston rod of the moving ring beam pin cylinder 2 extends outwards, and the moving ring beam pin is inserted into the pin hole on the pile leg. Subsequently, the electromagnet DT7 of the lifting cylinder reversing valve 52 is powered on, and the electromagnet DT8 is not powered on. The lifting cylinder reversing valve 52 works in the left position. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3 through the second one-way valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 extends out, and the oil in the rod cavity of the lifting cylinder 3 returns to the oil tank 10 through the inverse proportional overflow valve 53. Since the system actively exerts force to lift the marine lifting platform in this process and the required oil pressure of the system is very high, a very large current control signal is given to the proportional overflow valve 54 to make the safety pressure of the system match the load. At the same time, in this process, the hydraulic system does not require back pressure. Therefore, a maximum current control signal is input to the inverse proportional overflow valve 19 to make the back pressure of the hydraulic system return oil the smallest or have no back pressure, avoiding heat generation caused by the back pressure of the return oil and resulting in energy loss.

[0068] After the piston rod of the lifting cylinder 3 fully extends, energize the electromagnet DT6 of the pin cylinder reversing valve 42 and de-energize the electromagnet DT5. The pin cylinder reversing valve 42 works in its right position. At this time, the pressure oil at the outlet of the main pump 41 enters the rod chamber of the moving ring beam pin cylinder 2 and both chambers of the fixed ring beam pin cylinder 1. The piston rod of the moving ring beam pin cylinder 2 retracts, and the moving ring beam pin is pulled out from the pin hole on the leg. The piston rod of the fixed ring beam pin cylinder 1 extends outwards, and the fixed ring beam pin is inserted into the pin hole on the leg. Subsequently, energize the electromagnet DT8 of the lifting cylinder reversing valve 52 and de-energize the electromagnet DT7. The lifting cylinder reversing valve 52 works in its right position. The pressure oil at the outlet of the lifting pump 51 enters the rod chamber of the lifting cylinder 3 through the second check valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 retracts, and the oil in the rodless chamber of the lifting cylinder 3 returns to the oil tank 10 through the inverse proportional overflow valve 53. At this time, the moving ring beam 30 rises. During this process, the system actively exerts force to lift the moving ring beam 30. The system load is small and no backpressure is required. Therefore, give a very small current control signal to the proportional overflow valve 54 to make the system safety pressure match the load; give the maximum current control signal to the inverse proportional overflow valve 19 to minimize or eliminate the backpressure of the hydraulic system return oil, avoiding heat generation caused by the return oil backpressure and energy loss.

[0069] Repeat the above actions multiple times to achieve the stable rise of the offshore platform.

[0070] When the lifting device is in the leg lowering working condition:

[0071] When the lifting device is in the leg lowering working condition, the offshore lifting platform mechanically connected to the fixed ring beam is fixed and the pile fixing cylinder retracts, and the leg descends relative to the offshore lifting platform.

[0072] The working process of the leg descending relative to the offshore lifting platform is as follows:

[0073] The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are energized. The electromagnet DT5 of the pin cylinder reversing valve 42 is energized, and the electromagnet DT6 is not energized. The pin cylinder reversing valve 42 works in the left position. At this time, the pressure oil at the outlet of the main pump 41 enters the rodless cavity of the fixed ring beam pin cylinder 1 and both cavities of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts, and the fixed ring beam pin is pulled out from the pin hole on the leg. The piston rod of the moving ring beam pin cylinder 2 extends outwards, and the moving ring beam pin inserts into the pin hole on the leg. Subsequently, the electromagnet DT7 of the lifting cylinder reversing valve 52 is energized, and the electromagnet DT8 is not energized. The lifting cylinder reversing valve 52 works in the left position. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3 through the second check valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 extends outwards. The oil in the rod cavity of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. At this time, the leg 10 descends relative to the fixed ring beam 20, that is, the leg 10 descends relative to the offshore lifting platform. During this process, the active output of the hydraulic system is small, the safety pressure of the hydraulic system is small, and due to the influence of the mass of the leg, the hydraulic system requires a medium back pressure. At this time, a small current signal is output to the proportional overflow valve 54 to make the system safety pressure match the load, and a medium-sized current control signal matching the load (i.e., the leg) is input to the inverse proportional overflow valve 53 to ensure that the leg can descend safely while avoiding excessive heat generation in the system caused by excessive back pressure of the return oil, resulting in energy loss.

[0074] When the piston rod of the lifting cylinder 3 is fully extended, the electromagnet DT6 of the pin cylinder reversing valve 42 is energized, and the electromagnet DT5 is de-energized. At this time, the pressure oil at the outlet of the main pump 41 enters the rod cavity of the moving ring beam pin cylinder 2 and both cavities of the fixed ring beam pin cylinder 1. The piston rod of the moving ring beam pin cylinder 2 retracts, and the moving ring beam pin is pulled out from the pin hole on the leg. The piston rod of the fixed ring beam pin cylinder 1 extends outwards, and the fixed ring beam pin inserts into the pin hole on the leg. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is energized, and the electromagnet DT7 is not energized. The lifting cylinder reversing valve 52 works in the right position. The pressure oil at the outlet of the lifting pump 51 enters the rod cavity of the lifting cylinder 3 through the second check valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 retracts. The oil in the rodless cavity of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. At this time, the moving ring beam 30 rises relative to the leg 10. During this process, the active output of the hydraulic system is very small, and the hydraulic system does not require back pressure. Therefore, a very small current control signal is input to the proportional overflow valve 54, and a maximum current control signal is input to the inverse proportional overflow valve 53 to make the system safety pressure small and make the back pressure of the hydraulic system return oil minimum or without back pressure.

[0075] Repeat the above actions multiple times to achieve the stable descent of the leg.

[0076] When the lifting device is in the leg rising working condition:

[0077] When the lifting device is in the leg rising working condition, the offshore lifting platform mechanically connected to the fixed ring beam is fixed and the pile fixing cylinder retracts, and the leg rises relative to the offshore lifting platform.

[0078] The working process of the leg rising relative to the offshore lifting platform is as follows: The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are powered on. The electromagnet DT5 of the pin cylinder reversing valve 42 is powered on and the electromagnet DT6 is not powered on. The pin cylinder reversing valve 42 works in the left position. The pressure oil at the outlet of the main pump 41 enters the rodless cavity of the fixed ring beam pin cylinder 1 and both cavities of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts, and the fixed ring beam pin is pulled out from the pin hole on the leg. The piston rod of the moving ring beam pin cylinder 2 extends outwards, and the moving ring beam pin is inserted into the pin hole on the leg. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is powered on and the electromagnet DT7 is not powered on. The lifting cylinder reversing valve 52 works in the right position. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3 through the second one-way valve 55 and the lifting cylinder reversing valve 52. The piston rod of the lifting cylinder 3 retracts, and the oil in the rodless cavity of the lifting cylinder 3 returns to the oil tank 10 through the inverse proportional overflow valve 53. At this time, the leg rises relative to the fixed ring beam 20 and the entire offshore lifting platform. In this process, the hydraulic system does work to make the leg 10 rise. The system actively outputs force, and the hydraulic system does not require back pressure. Therefore, a medium current control signal is input to the proportional overflow valve 54 to make the system safety pressure match the load (the leg), and a maximum current control signal is input to the inverse proportional overflow valve 53 to minimize or eliminate the back pressure of the hydraulic system return oil, avoiding heat generation caused by the back pressure of the return oil and energy loss.

[0079] After the piston rod of the lifting cylinder 3 fully retracts, the electromagnet DT6 of the latch cylinder reversing valve 42 is energized and the electromagnet DT5 is de-energized. The latch cylinder reversing valve 42 switches to the right position for operation. At this time, the piston rod of the fixed ring beam latch cylinder 1 extends, and the fixed ring beam latch is inserted into the latch hole on the leg 10. The piston rod of the moving ring beam latch cylinder 2 retracts, and the moving ring beam latch is pulled out from the latch hole on the leg 10. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is de-energized and the electromagnet DT7 is energized. The lifting cylinder reversing valve 52 switches to the left position for operation. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3, and the piston rod of the lifting cylinder 3 extends. The oil in the rod chamber of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. The moving ring beam 30 descends relative to the leg. During this process, since the active output of the hydraulic system is small and the back pressure required by the hydraulic system is small, a very small current control signal is input to the proportional overflow valve 54 to make the safety pressure of the hydraulic system small, and a larger current control signal is input to the inverse proportional overflow valve 53 to make the oil return back pressure of the hydraulic system small, reducing the heat generation of the system.

[0080] Repeatedly perform the above actions multiple times to achieve the stable rise of the leg.

[0081] When the lifting device is in the preloading condition:

[0082] When the lifting device is in the preloading condition, it is necessary to lower the leg relative to the lifting platform and step on it firmly to fix it. The load of the hydraulic system in the preloading condition is greater than its load in the leg lowering condition.

[0083] The working process of the preloading of the hydraulic control system of the lifting device is as follows: The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are electrified. The electromagnet DT5 of the pin cylinder reversing valve 42 is electrified, and the electromagnet DT6 is not electrified. The pin cylinder reversing valve 42 works in the left position. The pressure oil at the outlet of the main pump 41 enters the rod chamber of the fixed ring beam pin cylinder 1 and both chambers of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts, and the fixed ring beam pin is pulled out from the pin hole on the leg. The piston rod of the moving ring beam pin cylinder 2 extends outwards, and the moving ring beam pin inserts into the pin hole on the leg. Subsequently, the electromagnet DT7 of the lifting cylinder reversing valve 52 is not electrified, and the electromagnet DT8 is electrified. The lifting cylinder reversing valve 52 works in the right position. The pressure oil at the outlet of the lifting pump 51 enters the rod chamber of the lifting cylinder 3. The oil in the rodless chamber of the lifting cylinder 3 returns to the oil tank 10 through the inverse proportional overflow valve 53. The piston rod of the lifting cylinder 3 retracts. At this time, the hydraulic system does not require backpressure, and the hydraulic system actively outputs force for preloading. The oil pressure of the entire hydraulic system is relatively high, and no backpressure is required. Therefore, a relatively large current control signal is input to the proportional overflow valve 54 to make the safety pressure of the hydraulic system relatively high, and a maximum current control signal is input to the inverse proportional overflow valve 53 to make the backpressure of the hydraulic return oil of the hydraulic system relatively small or without backpressure, reducing system heating.

[0084] After the piston rod of the lifting cylinder 3 fully extends, the electromagnet DT6 of the pin cylinder reversing valve 42 is electrified, and the electromagnet DT5 is not electrified. The pin cylinder reversing valve 42 switches to the right position. At this time, the fixed ring beam pin inserts into the pin hole on the leg 10, and the moving ring beam pin is pulled out from the pin hole on the leg 10. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is electrified, and the electromagnet DT7 is not electrified. The piston rod of the lifting cylinder 3 retracts, thereby driving the moving ring beam 30 to rise. During this process, the oil pressure of the hydraulic system is relatively small, and the hydraulic system does not require backpressure. Therefore, a relatively small current control signal is input to the proportional overflow valve 54 to make the safety pressure of the hydraulic system relatively small, and a maximum current control signal is input to the inverse proportional overflow valve 53 to make the backpressure of the hydraulic return oil of the hydraulic system relatively small or without backpressure.

[0085] Repeatedly performing the above actions can achieve the preloading of the hydraulic control system of the lifting device.

[0086] When the lifting device is in the pile pulling working condition:

[0087] When the lifting device is in the pile pulling working condition, it is necessary to pull the leg out of the water bottom. The load of the hydraulic system in the pile pulling working condition is greater than its load in the leg rising working condition.

[0088] The working process of the pile extraction of the lifting device is as follows: The motor 9 drives the main pump 41 and the lifting pump 51 to rotate. The electromagnetic overflow valve 43, the inverse proportional overflow valve 53, and the proportional overflow valve 54 are energized. The electromagnet DT5 of the pin cylinder reversing valve 42 is energized, and the electromagnet DT6 is not energized. The pin cylinder reversing valve 42 works in the left position. The pressure oil at the outlet of the main pump 41 enters the rodless cavity of the fixed ring beam pin cylinder 1 and both cavities of the moving ring beam pin cylinder 2. The piston rod of the fixed ring beam pin cylinder 1 retracts, and the fixed ring beam pin is pulled out from the pin hole on the pile leg. The piston rod of the moving ring beam pin cylinder 2 extends outward, and the moving ring beam pin inserts into the pin hole on the pile leg. Subsequently, the electromagnet DT7 of the lifting cylinder reversing valve 52 is energized, and the electromagnet DT8 is not energized. The lifting cylinder reversing valve 52 works in the left position. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3. The oil in the rod chamber of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. The piston rod of the lifting cylinder 3 extends. At this time, the system actively exerts force to extract the pile, the system pressure is relatively high and no back pressure is required. Therefore, a relatively large current control signal is input to the proportional overflow valve 54 to make the safety pressure of the hydraulic system relatively high, and a maximum current control signal is input to the inverse proportional overflow valve 53 to make the back pressure of the hydraulic system return oil relatively small or without back pressure, reducing the system heat generation.

[0089] After the piston rod of the lifting cylinder 3 is fully retracted, the electromagnet DT6 of the pin cylinder reversing valve 42 is energized, and the electromagnet DT5 is de-energized. The pin cylinder reversing valve 42 switches to the right position. The piston rod of the fixed ring beam pin cylinder 1 extends, and the fixed ring beam pin inserts into the pin hole on the pile leg 10. The piston rod of the moving ring beam pin cylinder 2 retracts, and the moving ring beam pin is pulled out from the pin hole on the pile leg 10. Subsequently, the electromagnet DT8 of the lifting cylinder reversing valve 52 is de-energized, and the electromagnet DT7 is energized. The lifting cylinder reversing valve 52 switches to the left position. The pressure oil at the outlet of the lifting pump 51 enters the rodless cavity of the lifting cylinder 3. The piston rod of the lifting cylinder 3 extends. The oil in the rod chamber of the lifting cylinder 3 returns to the fuel tank 10 through the inverse proportional overflow valve 53. The moving ring beam 30 descends relative to the pile leg. During this process, since the active force of the hydraulic system is relatively small and the back pressure required by the hydraulic system is relatively small, a very small current control signal is input to the proportional overflow valve 54 to make the safety pressure of the hydraulic system relatively small, and a relatively large current control signal is input to the inverse proportional overflow valve 53 to make the back pressure of the hydraulic system return oil relatively small, reducing the system heat generation.

[0090] Example 1:

[0091] The lifting device includes a leg 10, a fixed collar beam 20 and a moving collar beam 30 sleeved outside the leg 10 from top to bottom. The fixed collar beam 20 and the moving collar beam 30 are connected by a lifting oil cylinder 3. A fixed collar beam pin matching with the pin hole on the leg 10 and a fixed collar beam pin oil cylinder 1 for driving the fixed collar beam pin are arranged on the fixed collar beam 20. A moving collar beam pin matching with the pin hole on the leg 10 and a moving collar beam pin oil cylinder 2 for driving the moving collar beam pin are arranged on the moving collar beam 30. The hydraulic control system includes an oil tank 40, a pin control system and a lifting control system. The pin control system includes a main pump 41 and a pin oil cylinder reversing valve 42. The inlet of the main pump 41 is communicated with the oil tank 40. The outlet of the main pump 41 is simultaneously communicated with the rod chamber of the fixed collar beam pin oil cylinder 1, the rod chamber of the moving collar beam pin oil cylinder 2 and the inlet of the pin oil cylinder reversing valve 42. The outlet of the pin oil cylinder reversing valve 42 is communicated with the oil tank 40. The first working oil port and the second working oil port of the pin oil cylinder reversing valve 42 are respectively communicated with the rodless chamber of the fixed collar beam pin oil cylinder 1 and the rodless chamber of the moving collar beam pin oil cylinder 2. The lifting control system includes a lifting pump 51, a lifting oil cylinder reversing valve 52 and an inverse proportional overflow valve 53. The inlet of the lifting pump 51 is communicated with the oil tank 40. The outlet of the lifting pump 51 is communicated with the inlet of the lifting oil cylinder reversing valve 52. The first working oil port of the lifting oil cylinder reversing valve 52 is communicated with the rod chamber of the lifting oil cylinder 3. The second working oil port of the lifting oil cylinder reversing valve 52 is communicated with the rodless chamber of the lifting oil cylinder 3. The outlet of the lifting oil cylinder reversing valve 52 is communicated with the inlet of the inverse proportional overflow valve 53. The outlet of the inverse proportional overflow valve 53 is communicated with the oil tank 40. The first fixed pile oil cylinder reversing valve 81 and the second fixed pile oil cylinder reversing valve 82 are both three-position four-way electromagnetic reversing valves. The fixed collar beam pin oil cylinder 1 and the moving collar beam pin oil cylinder 2 are both differential hydraulic cylinders.

[0092] Embodiment 2:

[0093] Embodiment 2 is basically the same as Embodiment 1, and the difference is as follows:

[0094] The lifting control system further includes a proportional overflow valve 54. The oil inlet of the proportional overflow valve 54 is communicated with the oil outlet of the lift pump 51, and the oil outlet of the proportional overflow valve 54 is communicated with the fuel tank 40. The pin control system further includes an electromagnetic overflow valve 43. The oil inlet of the electromagnetic overflow valve 43 is communicated with the oil outlet of the main pump 41, and the oil outlet of the electromagnetic overflow valve 43 is communicated with the fuel tank 40. A first one-way valve 44 is provided on the oil path between the oil outlet of the main pump 41 and the oil inlet of the pin cylinder reversing valve 42. The oil inlet of the first one-way valve 44 is simultaneously communicated with the oil outlet of the main pump 41 and the oil inlet of the electromagnetic overflow valve 43, and the oil outlet of the first one-way valve 44 is communicated with the oil inlet of the pin cylinder reversing valve 42. A second one-way valve 55 is provided on the oil path between the oil outlet of the lift pump 51 and the oil inlet of the lift cylinder reversing valve 52. The oil inlet of the second one-way valve 55 is simultaneously communicated with the oil outlet of the lift pump 51 and the oil inlet of the proportional overflow valve 54, and the oil outlet of the second one-way valve 55 is communicated with the oil inlet of the lift cylinder reversing valve 52.

[0095] Embodiment 3:

[0096] Embodiment 3 is basically the same as Embodiment 1, except that:

[0097] The lifting device further includes a plurality of upper pile fixing cylinders 6 and a plurality of lower pile fixing cylinders 7. The plurality of upper pile fixing cylinders 6 are evenly arranged along the outer periphery of the pile leg 10, and the outer end of the piston rod of the upper pile fixing cylinder 6 is in limit fit with the upper end of the pile leg 10. The plurality of lower pile fixing cylinders 7 are evenly arranged along the outer periphery of the pile leg 10, and the outer end of the piston rod of the lower pile fixing cylinder 7 is in limit fit with the lower end of the pile leg 10. The hydraulic control system further includes a pile fixing control system. The pile fixing control system includes a first pile fixing cylinder reversing valve 81 and a second pile fixing cylinder reversing valve 82. The oil inlet of the first pile fixing cylinder reversing valve 81 and the oil inlet of the second pile fixing cylinder reversing valve 82 are simultaneously connected to the oil inlet of the pin cylinder reversing valve 42. The oil outlet of the first pile fixing cylinder reversing valve 81 and the oil outlet of the second pile fixing cylinder reversing valve 82 are connected to the oil tank 40. The first working oil port of the first pile fixing cylinder reversing valve 81 is simultaneously connected to the rodless cavities of the plurality of upper pile fixing cylinders 6, and the second working oil port of the first pile fixing cylinder reversing valve 81 is simultaneously connected to the rod cavities of the plurality of upper pile fixing cylinders 6. The first working oil port of the second pile fixing cylinder reversing valve 82 is simultaneously connected to the rodless cavities of the plurality of lower pile fixing cylinders 7, and the second working oil port of the second pile fixing cylinder reversing valve 82 is simultaneously connected to the rod cavities of the plurality of lower pile fixing cylinders 7. The number of the upper pile fixing cylinders 6 is 4, and the number of the lower pile fixing cylinders 7 is 4. A first hydraulic control check valve 83 is arranged on the pipeline between the first working oil port of the first pile fixing cylinder reversing valve 81 and the rodless cavity of the upper pile fixing cylinder 6. The oil inlet of the first hydraulic control check valve 83 is connected to the first working oil port of the first pile fixing cylinder reversing valve 81, the oil outlet of the first hydraulic control check valve 83 is simultaneously connected to the rodless cavities of the plurality of upper pile fixing cylinders 6, and the control port of the first hydraulic control check valve 83 is connected to the second working oil port of the first pile fixing cylinder reversing valve 81. A second hydraulic control check valve 84 is arranged on the pipeline between the first working oil port of the second pile fixing cylinder reversing valve 82 and the rodless cavity of the lower pile fixing cylinder 7. The oil inlet of the second hydraulic control check valve 84 is connected to the first working oil port of the second pile fixing cylinder reversing valve 82, the oil outlet of the second hydraulic control check valve 84 is simultaneously connected to the rodless cavities of the plurality of lower pile fixing cylinders 7, and the control port of the second hydraulic control check valve 84 is connected to the second working oil port of the second pile fixing cylinder reversing valve 82. The pile fixing control system further includes a first relief valve 85 and a second relief valve 86. The oil inlet of the first relief valve 85 is connected to the oil outlet of the first hydraulic control check valve 83, and the oil outlet of the first relief valve 85 is connected to the oil tank 40. The oil inlet of the second relief valve 86 is connected to the oil outlet of the second hydraulic control check valve 84, and the oil outlet of the second relief valve 86 is connected to the oil tank 40. The first pile fixing cylinder reversing valve 81 and the second pile fixing cylinder reversing valve 82 are both three-position four-way electromagnetic reversing valves.

[0098] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those of ordinary skill in the art according to the disclosure of the present invention shall be included in the protection scope recorded in the claims.

Claims

1. A hydraulic control system for a lifting device, characterized in that: the lifting device includes a leg (10) and a fixed ring beam (20) and a moving ring beam (30) sleeved outside the leg (10) from top to bottom. The fixed ring beam (20) and the moving ring beam (30) are connected by a lifting oil cylinder (3). A fixed ring beam pin matching with the pin hole on the leg (10) and a fixed ring beam pin oil cylinder (1) for driving the fixed ring beam pin are arranged on the fixed ring beam (20). A moving ring beam pin matching with the pin hole on the leg (10) and a moving ring beam pin oil cylinder (2) for driving the moving ring beam pin are arranged on the moving ring beam (30); the hydraulic control system includes an oil tank (40), a pin control system and a lifting control system. The pin control system includes a main pump (41) and a pin oil cylinder reversing valve (42). The inlet of the main pump (41) is communicated with the oil tank (40). The outlet of the main pump (41) is simultaneously communicated with the rod cavity of the fixed ring beam pin oil cylinder (1), the rod cavity of the moving ring beam pin oil cylinder (2), and the inlet of the pin oil cylinder reversing valve (42). The outlet of the pin oil cylinder reversing valve (42) is communicated with the oil tank (40). The first working oil port and the second working oil port of the pin oil cylinder reversing valve (42) are respectively communicated with the rodless cavity of the fixed ring beam pin oil cylinder (1) and the rodless cavity of the moving ring beam pin oil cylinder (2); the lifting control system includes a lifting pump (51), a lifting oil cylinder reversing valve (52) and an inverse proportional overflow valve (53). The inlet of the lifting pump (51) is communicated with the oil tank (40). The outlet of the lifting pump (51) is communicated with the inlet of the lifting oil cylinder reversing valve (52). The first working oil port of the lifting oil cylinder reversing valve (52) is communicated with the rod cavity of the lifting oil cylinder (3). The second working oil port of the lifting oil cylinder reversing valve (52) is communicated with the rodless cavity of the lifting oil cylinder (3). The outlet of the lifting oil cylinder reversing valve (52) is communicated with the inlet of the inverse proportional overflow valve (53). The outlet of the inverse proportional overflow valve (53) is communicated with the oil tank (40); the lifting device further includes a plurality of upper fixed pile oil cylinders (6) and a plurality of lower fixed pile oil cylinders (7). The plurality of upper fixed pile oil cylinders (6) are uniformly arranged along the outer circumference of the leg (10). The outer end of the piston rod of the upper fixed pile oil cylinder (6) is in limit fit with the upper end of the leg (10). The plurality of lower fixed pile oil cylinders (7) are uniformly arranged along the outer circumference of the leg (10). The outer end of the piston rod of the lower fixed pile oil cylinder (7) is in limit fit with the lower end of the leg (10); The hydraulic control system further includes a pile fixing control system, which includes a first pile fixing oil cylinder reversing valve (81) and a second pile fixing oil cylinder reversing valve (82). The oil inlets of the first pile fixing oil cylinder reversing valve (81) and the second pile fixing oil cylinder reversing valve (82) are simultaneously connected to the oil inlet of the pin cylinder reversing valve (42). The oil outlets of the first pile fixing oil cylinder reversing valve (81) and the second pile fixing oil cylinder reversing valve (82) are connected to the oil tank (40). The first working oil port of the first pile fixing oil cylinder reversing valve (81) is simultaneously connected to the rodless cavities of a plurality of upper pile fixing oil cylinders (6), and the second working oil port of the first pile fixing oil cylinder reversing valve (81) is simultaneously connected to the rod cavities of a plurality of upper pile fixing oil cylinders (6). The first working oil port of the second pile fixing oil cylinder reversing valve (82) is simultaneously connected to the rodless cavities of a plurality of lower pile fixing oil cylinders (7), and the second working oil port of the second pile fixing oil cylinder reversing valve (82) is simultaneously connected to the rod cavities of a plurality of lower pile fixing oil cylinders (7).

2. The hydraulic control system of a lifting device according to claim 1, wherein: the pin control system further includes an electromagnetic overflow valve (43), the oil inlet of the electromagnetic overflow valve (43) is connected to the oil outlet of the main pump (41), and the oil outlet of the electromagnetic overflow valve (43) is connected to the oil tank (40); the lifting control system further includes a proportional overflow valve (54), the oil inlet of the proportional overflow valve (54) is connected to the oil outlet of the lifting pump (51), and the oil outlet of the proportional overflow valve (54) is connected to the oil tank (40).

3. The hydraulic control system of a lifting device according to claim 2, wherein: a first one-way valve (44) is provided on the oil path between the oil outlet of the main pump (41) and the oil inlet of the pin cylinder reversing valve (42). The oil inlet of the first one-way valve (44) is simultaneously connected to the oil outlet of the main pump (41) and the oil inlet of the electromagnetic overflow valve (43), and the oil outlet of the first one-way valve (44) is connected to the oil inlet of the pin cylinder reversing valve (42); a second one-way valve (55) is provided on the oil path between the oil outlet of the lifting pump (51) and the oil inlet of the lifting cylinder reversing valve (52). The oil inlet of the second one-way valve (55) is simultaneously connected to the oil outlet of the lifting pump (51) and the oil inlet of the proportional overflow valve (54), and the oil outlet of the second one-way valve (55) is connected to the oil inlet of the lifting cylinder reversing valve (52).

4. The hydraulic control system of a lifting device according to claim 3, wherein: the number of the upper pile fixing oil cylinders (6) is 4, and the number of the lower pile fixing oil cylinders (7) is 4.

5. The hydraulic control system of a lifting device according to claim 3, wherein: A first hydraulic control check valve (83) is provided on the pipeline between the first working oil port of the first fixed pile cylinder reversing valve (81) and the rodless cavity of the upper fixed pile cylinder (6). The oil inlet of the first hydraulic control check valve (83) is communicated with the first working oil port of the first fixed pile cylinder reversing valve (81). The oil outlet of the first hydraulic control check valve (83) is simultaneously communicated with the rodless cavities of a plurality of upper fixed pile cylinders (6). The control port of the first hydraulic control check valve (83) is communicated with the second working oil port of the first fixed pile cylinder reversing valve (81). A second hydraulic control check valve (84) is provided on the pipeline between the first working oil port of the second fixed pile cylinder reversing valve (82) and the rodless cavity of the lower fixed pile cylinder (7). The oil inlet of the second hydraulic control check valve (84) is communicated with the first working oil port of the second fixed pile cylinder reversing valve (82). The oil outlet of the second hydraulic control check valve (84) is simultaneously communicated with the rodless cavities of a plurality of lower fixed pile cylinders (7). The control port of the second hydraulic control check valve (84) is communicated with the second working oil port of the second fixed pile cylinder reversing valve (82).

6. The hydraulic control system of a lifting device according to claim 5, characterized in that: The fixed pile control system further includes a first overflow valve (85) and a second overflow valve (86). The oil inlet of the first overflow valve (85) is communicated with the oil outlet of the first hydraulic control check valve (83). The oil outlet of the first overflow valve (85) is communicated with the fuel tank (40). The oil inlet of the second overflow valve (86) is communicated with the oil outlet of the second hydraulic control check valve (84). The oil outlet of the second overflow valve (86) is communicated with the fuel tank (40).

7. The hydraulic control system of a lifting device according to claim 6, characterized in that: The first fixed pile cylinder reversing valve (81), the second fixed pile cylinder reversing valve (82), the bolt cylinder reversing valve (42) and the lifting cylinder reversing valve (52) are all three-position four-way electromagnetic reversing valves.

8. The hydraulic control system of a lifting device according to claim 1, characterized in that: The fixed ring beam bolt cylinder (1) and the moving ring beam bolt cylinder (2) are both differential hydraulic cylinders.

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