Pilot control hydraulic system of container reach stacker

Abstract

The invention discloses a container reach stacker pilot control hydraulic system, and belongs to the field of hydraulic system design, the container reach stacker pilot control hydraulic system comprises an oil tank, an oil pump, a multi-way valve, a lifting appliance oil supply valve group, a damping valve group and a damping oil cylinder, an output port of the oil pump is simultaneously connected with the multi-way valve and an oil inlet of the lifting appliance oil supply valve group, and a working oil port of the lifting appliance oil supply valve group is connected with an oil inlet of the damping valve group; a working oil port of the damping valve group is connected with the damping oil cylinder, an output port of the oil pump is simultaneously connected with an oil inlet of the pilot pressure reducing valve group, and a working oil port of the pilot pressure reducing valve group is connected with a working oil port of the damping valve group. Continuous and stable oil supply to the lifting appliance and the multi-way valve is achieved, stable work of the multi-way valve is guaranteed, swing of the lifting appliance is reduced, and then the stability of goods of the reach stacker in the air is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hydraulic systems, and in particular to a pilot control hydraulic system for a container front-end crane. Background Technology

[0002] A reach stacker is a type of crane used for loading and unloading containers. It belongs to the category of lifting equipment and can also be considered a type of mobile machinery. Container reach stackers are specifically designed for containers of certain sizes and are mainly used for stacking containers and horizontal transport within terminals and yards. Compared to forklifts, they offer advantages such as maneuverability, ease of operation, good stability, lower wheel pressure, higher stacking depth, and higher yard utilization. They can also perform straddle container operations. They are particularly suitable for container loading and unloading at small and medium-sized ports, railway transfer stations, and highway transfer stations.

[0003] For reach stackers using electro-proportional pilot control multi-way valves, the electro-proportional pilot valve requires a continuous and stable input of pilot oil to ensure stable operation of hydraulic components such as the multi-way valve. Additionally, the damping cylinder of the reach stack spreader requires a continuous and stable pressure of oil to ensure the spreader provides damping during oscillation, reducing the swaying and floating of the cargo and spreader, thus ensuring the stability of the load in the air. However, current technology lacks a dedicated structure to guarantee a stable output of this pressure oil.

[0004] Therefore, how to provide a pilot control hydraulic system for container front-end cranes that ensures stable system operation is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a pilot control hydraulic system for container front-end cranes. By setting up a pilot pressure reducing valve group, a continuous and stable oil supply is achieved to the spreader and multi-way valves, ensuring the stable operation of the multi-way valves and reducing the swaying of the spreader.

[0006] To solve the above-mentioned technical problems, the present invention provides a pilot control hydraulic system for a container front-end crane, including an oil tank, an oil pump, a multi-way valve, a spreader oil supply valve group, a damping valve group, and a damping cylinder. The output port of the oil pump is simultaneously connected to the oil inlet of the multi-way valve and the spreader oil supply valve group. The working oil port of the spreader oil supply valve group is connected to the oil inlet of the damping valve group. The working oil port of the damping valve group is connected to the damping cylinder. The system also includes a pilot pressure reducing valve group, the output port of the oil pump being simultaneously connected to the oil inlet of the pilot pressure reducing valve group. The working oil port of the pilot pressure reducing valve group is connected to the working oil port of the damping valve group.

[0007] Preferably, the multi-way valve includes multiple hydraulically controlled proportional directional valves connected in parallel and a pilot proportional valve connected to the hydraulic control port of each of the hydraulically controlled proportional directional valves.

[0008] Preferably, the spreader oil supply valve assembly includes a spreader hydraulic control proportional directional valve and a spreader pilot proportional valve connected to the hydraulic control port of the spreader hydraulic control proportional directional valve.

[0009] Preferably, the damping valve assembly includes a damping pressure reducing valve, a first adjustable speed limiting valve, a second adjustable speed limiting valve, a first damping check valve, and a second damping check valve. The inlet of the damping pressure reducing valve is connected to the outlet of the lifting device oil supply valve assembly. The outlet of the damping pressure reducing valve is connected to the rodless chamber and the rod chamber of the damping cylinder through the first adjustable speed limiting valve and the second adjustable speed limiting valve, respectively. The rodless chamber and the rod chamber of the damping cylinder are connected to the oil tank through the first damping check valve and the second damping check valve, respectively.

[0010] Preferably, the damping cylinders include two damping cylinders, with the rodless chambers of the two damping cylinders connected together and the rod chambers of the two damping cylinders connected together.

[0011] Preferably, the damping valve assembly is provided with an interface for connecting to a subsequent functional valve assembly of the lifting device.

[0012] Preferably, the oil pump includes a first pump and a second pump synchronously driven by a drive motor. The first pump is connected to the first oil inlet of the multi-way valve, the spreader oil supply valve group and the pilot pressure reducing valve group, and the second pump is connected to the second oil inlet of the multi-way valve.

[0013] Preferably, the system further includes an accumulator, and the accumulator port of the pilot pressure reducing valve assembly is connected to the accumulator.

[0014] Preferably, the pilot port of the pilot pressure reducing valve assembly is connected to both the pilot port of the multi-way valve and the pilot port of the lifting device oil supply valve assembly.

[0015] Preferably, the pilot pressure reducing valve assembly includes a pilot pressure reducing valve, a pilot safety valve, a first pilot check valve, and a second pilot check valve. The inlet of the pilot pressure reducing valve is connected to the output port of the oil pump. The outlet of the pilot pressure reducing valve is simultaneously connected to the inlet of the pilot safety valve, the inlet of the first pilot check valve, and the inlet of the second pilot check valve. The control port of the pilot pressure reducing valve and the outlet of the pilot safety valve are connected to the oil tank. The outlet of the first pilot check valve is connected to the inlet of the damping valve assembly. The outlet of the second pilot check valve is connected to the pilot port of the accumulator, the multi-way valve, and the spreader oil supply valve assembly.

[0016] This invention provides a pilot control hydraulic system for a container front-end crane, including an oil tank, an oil pump, a multi-way valve, a spreader oil supply valve assembly, a damping valve assembly, and a damping cylinder. The output port of the oil pump is simultaneously connected to the inlet ports of the multi-way valve and the spreader oil supply valve assembly. The working port of the spreader oil supply valve assembly is connected to the inlet port of the damping valve assembly. The working port of the damping valve assembly is connected to the damping cylinder. The system also includes a pilot pressure reducing valve assembly, where the output port of the oil pump is simultaneously connected to the inlet port of the pilot pressure reducing valve assembly, and the working port of the pilot pressure reducing valve assembly is connected to the working port of the damping valve assembly.

[0017] During operation, the hydraulic oil output from the oil pump enters the multi-way valve and the spreader oil supply valve group respectively. The multi-way valve connects to each actuator, and the spreader oil supply valve group connects to the damping cylinder through the damping valve group to supply oil to the damping cylinder. At the same time, the hydraulic oil output from the oil pump also enters the pilot pressure reducing valve group. The oil outlet of the pilot pressure reducing valve group is also connected to the oil inlet of the damping valve group. The spreader oil supply valve group and the pilot pressure reducing valve group form redundancy. If one has a problem, the other can continue to supply oil to the damping valve group, so as to achieve a continuous and stable oil supply to the spreader and the multi-way valve, ensure the stable operation of the multi-way valve, reduce the swing of the spreader, and thus ensure the stability of the front-mounted load in the air. Attached Figure Description

[0018] Figure 1 A hydraulic schematic diagram of a specific embodiment of the pilot control hydraulic system for a container reach stacker provided by the present invention;

[0019] Figure 2 A hydraulic schematic diagram of a multi-way valve in a specific embodiment of the pilot control hydraulic system for a container front-end crane provided by the present invention;

[0020] Figure 3 A hydraulic schematic diagram of the spreader oil supply valve group in a specific embodiment of the pilot control hydraulic system for container front-end cranes provided by the present invention;

[0021] Figure 4 A hydraulic schematic diagram of the damping valve group in a specific embodiment of the pilot control hydraulic system for a container front-end crane provided by the present invention;

[0022] Figure 5 This is a hydraulic schematic diagram of the pilot pressure reducing valve assembly in one specific embodiment of the pilot control hydraulic system for container front-end cranes provided by the present invention.

[0023] Among them, 1-oil tank; 2-oil pump; 3-drive motor; 4-multi-way valve; 41-first actuator hydraulic proportional directional valve; 411-first actuator pilot proportional valve; 412-second actuator pilot proportional valve; 42-second actuator hydraulic proportional directional valve; 421-third actuator pilot proportional valve; 422-fourth actuator pilot proportional valve; 5-spreading device common valve group; 51-spreading device hydraulic proportional directional valve; 6-damping valve group; 61-damping pressure reducing valve; 62-first adjustable speed limiting valve; 63-second adjustable speed limiting valve; 64-damping safety valve; 65-first damping check valve; 66-second damping check valve; 7-pilot pressure reducing valve group; 71-pilot pressure reducing valve; 72-pilot safety valve; 73-first pilot check valve; 74-second pilot check valve; 8-accumulator; 9-damping cylinder. Detailed Implementation

[0024] The core of this invention is to provide a pilot control hydraulic system for container front-end cranes. By setting up a pilot pressure reducing valve group, a continuous and stable oil supply is achieved to the spreader and multi-way valves, ensuring the stable operation of the multi-way valves and reducing the swaying of the spreader.

[0025] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Please refer to Figure 1 , Figure 1 This is a hydraulic schematic diagram of a specific embodiment of the pilot control hydraulic system for a container reach stacker provided by the present invention.

[0027] This invention provides a pilot control hydraulic system for a container reach stacker, including an oil tank 1, an oil pump 2, a multi-way valve 4, a spreader oil supply valve group, a damping valve group 6, and a damping cylinder 9. The oil pump 2's inlet is connected to the oil tank 1, and its output is connected to both the inlet of the multi-way valve 4 and the inlet of the spreader oil supply valve group. The working port of the multi-way valve 4 is connected to the actuators, distributing oil to the boom's telescopic cylinder and luffing cylinder to achieve boom telescopic and luffing movements. The working port of the spreader oil supply valve group is connected to the inlet of the damping valve group 6, which in turn is connected to the damping cylinder 9. The damping cylinder 9 is connected to the spreader to prevent it from swaying, ultimately reducing its swing, floating, and speed. The oil supply and return of the damping cylinder 9 are controlled according to different spreader states. The system also includes a pilot pressure reducing valve group 7, with the oil pump 2's output connected to the inlet of the pilot pressure reducing valve group 7, and the pilot pressure reducing valve group 7's working port connected to the working port of the damping valve group 6. The pilot pressure reducing valve group 7 reduces the high pressure oil output by the oil pump 2 to the set pressure, providing a continuous and stable pressure oil for the multi-way valve 4, the lifting device oil supply valve group and the damping cylinder 9.

[0028] During operation, the hydraulic oil output by oil pump 2 enters the multi-way valve 4 and the spreader oil supply valve group respectively. The multi-way valve 4 is connected to each actuator. The spreader oil supply valve group is connected to the damping cylinder 9 through the damping valve group 6, supplying oil to the damping cylinder 9. At the same time, the hydraulic oil output by oil pump 2 enters the pilot pressure reducing valve group 7. The oil outlet of the pilot pressure reducing valve group 7 is also connected to the oil inlet of the damping valve group 6. The spreader oil supply valve group and the pilot pressure reducing valve group 7 form redundancy. If one has a problem, the other can continue to supply oil to the damping valve group 6, realizing a continuous and stable oil supply to the spreader and the multi-way valve 4, ensuring the stable operation of the multi-way valve 4, reducing the swing of the spreader, and thus ensuring the stability of the front-lifted cargo in the air.

[0029] Please refer to Figure 2 , Figure 2 This is a hydraulic schematic diagram of a multi-way valve in a specific embodiment of the pilot control hydraulic system for a container front-end crane provided by the present invention.

[0030] In the pilot control hydraulic system for a container reach stacker provided in a specific embodiment of the present invention, the multi-way valve 4 includes multiple parallel actuator hydraulic proportional directional valves and actuator pilot proportional valves connected to the hydraulic ports of each actuator hydraulic proportional directional valve. Specifically, it includes a first actuator hydraulic proportional directional valve 41 and a second actuator hydraulic proportional directional valve 42. The first actuator hydraulic proportional directional valve 41 has a first actuator pilot proportional valve 411 and a second actuator pilot proportional valve 412 at both hydraulic ports. The second actuator hydraulic proportional directional valve 42 has a third actuator pilot proportional valve 421 and a fourth actuator pilot proportional valve 422 at both hydraulic ports. 4P1 and 4P2 are oil inlets connected to the oil pump 2's oil outlet. 4T is the oil return port connected to the hydraulic oil tank 1. 4A1, 4B1, 4A2, and 4B2 are working oil ports connected to the actuator. 4Pp is the pilot oil inlet connected to the pilot pressure reducing valve group 7.

[0031] Please refer to Figure 3 , Figure 3 This is a hydraulic schematic diagram of the spreader oil supply valve group in a specific embodiment of the pilot control hydraulic system for container front-end cranes provided by the present invention.

[0032] The spreader oil supply valve assembly has only one working oil circuit, including the spreader hydraulic proportional directional valve 51 and the spreader pilot proportional valve connected to the hydraulic port of the spreader hydraulic proportional directional valve 51. 5A is its working oil port, connected to the oil inlet of the damping valve assembly 6; 5P1 is the oil inlet, connected to the oil supply port of the oil pump 2; 5T1 is the oil return port; and 5TP is the oil drain port, both connected to the hydraulic oil tank 1; 5YS is the pilot oil port, connected to the pilot pressure reducing valve assembly 7.

[0033] Please refer to Figure 4 , Figure 4 This is a hydraulic schematic diagram of the damping valve group in a specific embodiment of the pilot control hydraulic system for a container front-end crane provided by the present invention.

[0034] In the pilot control hydraulic system for a container reach stacker provided in this specific embodiment of the invention, the damping valve assembly 6 includes a damping pressure reducing valve 61, a first adjustable speed limiting valve 62, a second adjustable speed limiting valve 63, a first damping check valve 65, and a second damping check valve 66. The inlet of the damping pressure reducing valve 61 is connected to the outlet of the spreader supply valve assembly and also to the outlet of the pilot pressure reducing valve assembly 7. The outlet of the damping pressure reducing valve 61 is divided into two paths, which are respectively connected to the rodless chamber and the rod chamber of the damping cylinder 9 through the first adjustable speed limiting valve 62 and the second adjustable speed limiting valve 63. The rodless chamber and the rod chamber of the damping cylinder 9 are respectively connected to the oil tank 1 through the first damping check valve 65 and the second damping check valve 66. A damping safety valve 64 can also be provided, and the outlets of the first damping check valve 65 and the second damping check valve 66 are connected to the oil tank 1 through the damping safety valve 64. The oil entering the damping valve assembly 6 needs to be depressurized before entering the subsequent damping cylinder 9. The adjustable speed limiting valve is connected to the rodless chamber of the damping cylinder 9 to control the flow rate of the oil returning from the rodless chamber. The oil circuits of the rodless chamber and the rod chamber of the damping cylinder 9 are isolated by a damping check valve and finally connected to a damping safety valve 64 to ensure system safety. 6P1 and 6P2 are both oil inlets. 6P1 is connected to the oil outlet of the spreader oil supply valve group and is the oil inlet of the damping valve group 6. The damping valve group 6 is provided with an interface 6P2 for connecting the spreader subsequent function valve group. 6T1 and 6T2 are both return oil ports. The return oil from the spreader subsequent function valve group flows from 6T2 and merges with the return oil of the damping valve group 6 itself, finally returning to the hydraulic oil tank 1 through 6T1. 6A1, 6B1, 6A2, and 6B2 are working oil ports. 6A1 and 6A2 are connected to the rod chamber of the damping cylinder 9, and 6B1 and 6B2 are connected to the rodless chamber of the damping cylinder 9.

[0035] Preferably, it includes two damping cylinders 9, with the rodless chambers of the two damping cylinders 9 connected together and the rod chambers of the two damping cylinders 9 connected together.

[0036] The oil pump 2 includes a first pump and a second pump synchronously driven by the drive motor 3. The first pump is connected to the first inlet of the multi-way valve 4, the lifting device oil supply valve group, and the pilot pressure reducing valve group 7, and the second pump is connected to the second inlet of the multi-way valve 4. It is a two-inlet, two-outlet type, with the two inlets drawing oil from the hydraulic oil tank 1 respectively. Driven by the oil pump 2 and the drive motor 3, the pressurized oil is output to the two inlets of the multi-way valve 4 respectively through the two outlets.

[0037] Please refer to Figure 5 , Figure 5 This is a hydraulic schematic diagram of the pilot pressure reducing valve assembly in one specific embodiment of the pilot control hydraulic system for container front-end cranes provided by the present invention.

[0038] Based on the container reach stack pilot control hydraulic system provided in the above specific embodiments, an accumulator 8 is also included, and the accumulator port of the pilot pressure reducing valve group 7 is connected to the accumulator 8. The pilot oil port of the pilot pressure reducing valve group 7 is simultaneously connected to the pilot oil port of the multi-way valve 4 and the spreader oil supply valve group.

[0039] Specifically, the pilot pressure reducing valve assembly 7 includes a pilot pressure reducing valve 71, a pilot safety valve 72, a first pilot check valve 73, and a second pilot check valve 74. The inlet of the pilot pressure reducing valve 71 is connected to the output port of the oil pump 2. The outlet of the pilot pressure reducing valve 71 is simultaneously connected to the inlet of the pilot safety valve 72, the inlet of the first pilot check valve 73, and the inlet of the second pilot check valve 74. The control port of the pilot pressure reducing valve 71 and the outlet of the pilot safety valve 72 are connected to the oil tank 1. The outlet of the first pilot check valve 73 is connected to the inlet of the damping valve assembly 6. The outlet of the second pilot check valve 74 is connected to the pilot port of the accumulator 8, the multi-way valve 4, and the spreader oil supply valve assembly. Pilot pressure reducing valve 71 ensures a stable output of pressure-reduced oil regardless of the valve group's inlet pressure. Pilot safety valve 72 has a set pressure slightly higher than the pressure-reducing pressure of pilot pressure reducing valve 71. If pilot pressure reducing valve 71 malfunctions and causes an increase in output pressure, pilot safety valve 72 can still limit the maximum pressure, ensuring that the valve group's output pressure does not affect subsequent components. Pilot check valves provide oil circuit isolation, ensuring that each output oil circuit does not interfere with each other. Specifically, 7P is the valve group inlet and connects to the oil pump 2's outlet; 7T is the valve group return port and connects to the hydraulic oil tank 1; 7A is the valve group pilot oil outlet and connects to the damping valve group 6's inlet; 7B1 and 7B2 are the valve group pilot oil outlets, respectively connected to the accumulator 8, the multi-way valve 4's 4Pp port, and the lifting device supply valve group's 5YS port; 7M is the valve group pilot oil pressure test port for troubleshooting.

[0040] The type and layout of each valve can be adjusted as needed, all of which are within the protection scope of this invention.

[0041] The specific working process is as follows: when the control actuator of the spreader or the multi-way valve 4 has a working requirement, the oil pump 2 enters the multi-way valve 4 and the spreader oil supply valve group from the 2P1 port and the 2P2 port respectively. Through the distribution of the respective valves, the oil flows to the actuator controlled by the multi-way valve 4 and the damping valve group 6 of the spreader.

[0042] The inlet of the pilot pressure reducing valve assembly 7 is connected in parallel to the outlet of the oil pump 2. As long as the oil pump 2 has oil output, the pilot pressure reducing valve assembly 7 will have a stable oil output. Pressure oil enters the pilot pressure reducing valve assembly 7 through inlet 7P, is reduced in pressure by pilot pressure reducing valve 71, and flows out from ports 7A, 7B1, and 7B2 of the pilot pressure reducing valve assembly 7. The oil flowing out from 7A flows to port 6P1 of the damping valve assembly 6, the oil flowing out from 7B1 flows to the pilot accumulator 88, and the oil flowing out from 7B2 is connected to the pilot oil port 5YS of the spreader oil supply valve assembly and the pilot oil inlet 4Pp of the multi-way valve 4 through hoses. On the one hand, this can provide stable pilot pressure oil for the spreader oil supply valve assembly and the multi-way valve 4. On the other hand, the pilot pressure reduction function of the spreader oil supply valve assembly and the pilot oil output of the pilot pressure reducing valve assembly 7 constitute system redundancy. If the pilot pressure reduction function of the spreader oil supply valve assembly or the pilot pressure reducing valve assembly 7 fails, the other can still output stable pilot oil, ensuring the normal operation of the multi-way valve 4 and the spreader oil supply valve assembly. From an energy-saving perspective, the electric reach stack lowers the boom by gravity. Only when the boom is lowering in a luffing manner does the drive motor 3 of the oil pump 2 not rotate. At this time, there is no pressure oil input to the spreader oil supply valve group and the pilot pressure reducing valve group 7. The pilot oil stored in the accumulator 8 can continue to provide a stable oil source to the multi-way valve 4, ensuring that the multi-way valve 4 can be operated normally and the whole vehicle can be used normally.

[0043] When the spreader is working normally, the oil supply valve group at port 5A continuously supplies oil to the spreader. Regardless of the spreader's swing, the oil in both chambers of the damping cylinder 9 can be replenished from port 6P1 through the damping pressure reducing valve 61. When the reach stacker is used for container transport, the spreader oil supply valve group stops working and no longer supplies oil to the damping valve group 6. As the spreader swings back and forth during vehicle movement, the oil in both the rodless and rod chambers of the damping cylinder 9 flows out through the adjustable speed limiting valve. If the oil in the damping cylinder 9 is insufficient, the adjustable speed limiting valve cannot control the oil flow. Consequently, the spreader damping system, consisting of the damping valve group 6 and the damping cylinder 9, cannot control the spreader's swing amplitude. Especially during sudden braking or acceleration, if the spreader's swing amplitude is large, it poses a threat to the safety of the entire vehicle and increases instability. Therefore, the output port 7A of the pilot pressure reducing valve assembly 7 is connected to the 6P1 port of the damping valve assembly 6. When the oil in the damping cylinder 9 decreases due to the swing of the spreader, the output oil of the pilot pressure reducing valve assembly 7 can continuously and effectively replenish the oil in the damping cylinder 9 through the damping pressure reducing valve 61 and the adjustable speed limiting valve, avoiding the aforementioned risks and improving the safety of the entire system. Within the pilot pressure reducing valve assembly 7, the one-way valve isolates the two oil circuits 7A and 7B1 and 7B2, ensuring that the pilot oil supplied by the pilot pressure reducing valve assembly 7 to the multi-way valve 4 and the spreader oil supply valve assembly does not interfere with the replenishment oil supplied to the spreader. At the same time, the one-way valve also protects the pilot pressure reducing valve assembly 7. Because the pressure oil at port 5A is at high pressure, the one-way valve can effectively isolate the high-pressure oil circuit, ensuring that port 7A is only used to output oil to port 6P1.

[0044] The pilot control hydraulic system for container reach stackers provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A pilot control hydraulic system for a container reach stacker, characterized in that, The system includes an oil tank (1), an oil pump (2), a multi-way valve (4), a spreader oil supply valve group, a damping valve group (6), and a damping cylinder (9). The output port of the oil pump (2) is connected to the inlet of the multi-way valve (4) and the oil supply valve group. The working port of the spreader oil supply valve group is connected to the inlet of the damping valve group (6). The working port of the damping valve group (6) is connected to the damping cylinder (9). The system also includes a pilot pressure reducing valve group (7). The output port of the oil pump (2) is connected to the inlet of the pilot pressure reducing valve group (7). The working port of the pilot pressure reducing valve group (7) is connected to the working port of the damping valve group (6).

2. The pilot control hydraulic system for a container reach stacker according to claim 1, characterized in that, The multi-way valve (4) includes multiple hydraulically controlled proportional directional valves connected in parallel and a pilot proportional valve connected to the hydraulic ports of each of the hydraulically controlled proportional directional valves.

3. The pilot control hydraulic system for a container reach stacker according to claim 1, characterized in that, The spreader oil supply valve group includes a spreader hydraulic control proportional valve (51) and a spreader pilot proportional valve connected to the hydraulic control port of the spreader hydraulic control proportional valve (51).

4. The pilot control hydraulic system for a container reach stacker according to claim 1, characterized in that, The damping valve assembly (6) includes a damping pressure reducing valve (61), a first adjustable speed limiting valve (62), a second adjustable speed limiting valve (63), a first damping check valve (65), and a second damping check valve (66). The oil inlet of the damping pressure reducing valve (61) is connected to the oil outlet of the lifting device oil supply valve assembly. The oil outlet of the damping pressure reducing valve (61) is connected to the rodless chamber and the rod chamber of the damping cylinder (9) through the first adjustable speed limiting valve (62) and the second adjustable speed limiting valve (63), respectively. The rodless chamber and the rod chamber of the damping cylinder (9) are connected to the oil tank (1) through the first damping check valve (65) and the second damping check valve (66), respectively.

5. The pilot control hydraulic system for a container reach stacker according to claim 4, characterized in that, It includes two damping cylinders (9), the rodless chambers of the two damping cylinders (9) are connected, and the rod chambers of the two damping cylinders (9) are connected.

6. The pilot control hydraulic system for a container reach stacker according to claim 5, characterized in that, The damping valve assembly (6) is provided with an interface for connecting the subsequent functional valve assembly of the lifting device.

7. The pilot control hydraulic system for a container reach stacker according to claim 1, characterized in that, The oil pump (2) includes a first pump and a second pump that are synchronously driven by a drive motor (3). The first pump is connected to the first oil inlet of the multi-way valve (4), the oil supply valve group of the lifting device and the pilot pressure reducing valve group (7), and the second pump is connected to the second oil inlet of the multi-way valve (4).

8. The pilot control hydraulic system for a container front-end crane according to any one of claims 1 to 7, characterized in that, It also includes an accumulator (8), and the accumulator port of the pilot pressure reducing valve group (7) is connected to the accumulator (8).

9. The pilot control hydraulic system for a container reach stacker according to claim 8, characterized in that, The pilot port of the pilot pressure reducing valve group (7) is simultaneously connected to the pilot port of the multi-way valve (4) and the pilot port of the lifting device oil supply valve group.

10. The pilot control hydraulic system for a container reach stacker according to claim 9, characterized in that, The pilot pressure reducing valve group (7) includes a pilot pressure reducing valve (71), a pilot safety valve (72), a first pilot check valve (73), and a second pilot check valve (74). The inlet of the pilot pressure reducing valve (71) is connected to the output port of the oil pump (2). The outlet of the pilot pressure reducing valve (71) is simultaneously connected to the inlet of the pilot safety valve (72), the inlet of the first pilot check valve (73), and the inlet of the second pilot check valve (74). The control port of the pilot pressure reducing valve (71) and the outlet of the pilot safety valve (72) are connected to the oil tank (1). The outlet of the first pilot check valve (73) is connected to the inlet of the damping valve group (6). The outlet of the second pilot check valve (74) is connected to the pilot port of the accumulator (8), the multi-way valve (4), and the lifting device oil supply valve group.

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