A hydraulic oil circuit for electric empty container stacker gantry lifting and potential energy recovery

Abstract

This invention discloses a hydraulic circuit for lifting and recovering potential energy of an electric empty container stacker gantry, comprising: a working interface for communicating with the working chamber of a working cylinder; a forward and reverse oil pump; a main motor mechanically connected to the forward and reverse oil pump to drive the pump in electric mode for oil supply, and to drive the pump to rotate for power generation in generator mode; an auxiliary oil pump; an auxiliary motor for driving the auxiliary oil pump for oil supply; and a hydraulically controlled proportional valve with one side connected to the working interface and the other side connected to one port of a first control valve group, and connected to an oil tank through a second control valve group. The other port of the first control valve group is connected to the forward and reverse oil pump and to the auxiliary oil pump through a first check valve, enabling the auxiliary oil pump to supply oil to the first control valve group. This effectively solves the problem of inconvenient energy recovery during oil return from the working cylinder.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, and more specifically, to a hydraulic circuit for lifting and recovering potential energy of an electric empty container stacker gantry. Background Technology

[0002] Current empty container stacker masts can reach high positions, where their potential energy is also high, making energy recovery quite substantial. The pressure oil during mast descent drives a hydraulic motor, which in turn drives a generator, thus achieving potential energy recovery.

[0003] Energy recovery is more practical in production when the gantry of the empty container stacker is in a higher position. However, when the gantry is in a lower position, the recovered energy cannot meet the energy consumption of the generator, resulting in greater energy loss. The hydraulic motor's flow rate is limited, preventing the gantry from descending quickly. When the hydraulic motor connected to the generator fails to rotate properly, the oil return flow is obstructed, preventing the gantry from descending normally.

[0004] In conclusion, how to effectively solve the problem of inconvenient energy recovery during the return of oil from the working cylinder is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a hydraulic circuit for lifting and recovering potential energy of an electric empty container stacker gantry. This hydraulic circuit can effectively solve the problem of inconvenient energy recovery when the working cylinder returns oil.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A hydraulic circuit for lifting and recovering potential energy of an electric empty container stacker gantry includes: a working interface for communicating with the working chamber of a working cylinder; a forward and reverse oil pump; a main motor mechanically connected to the forward and reverse oil pump to drive the pump in electric mode for oil supply, and to drive the pump to rotate for power generation in generator mode; an auxiliary oil pump; an auxiliary motor for driving the pump to supply oil; and a hydraulically controlled proportional valve connected on one side to the working interface and on the other side to one port of a first control valve group, and connected to an oil tank via a second control valve group. The other port of the first control valve group is connected to the forward and reverse oil pump and to the auxiliary oil pump via a first check valve, enabling the auxiliary oil pump to supply oil to the first control valve group.

[0008] In the hydraulic circuit used for lifting the gantry and recovering potential energy of the electric empty container stacker, the working interface is connected to the working chamber of the working cylinder during operation. When the working chamber needs to be rapidly supplied with high-pressure oil, the main motor starts working, the first control switch valve group opens, and the second control switch valve group closes. A large amount of high-pressure oil is supplied to the working chamber by the forward and reverse oil pump through the hydraulic proportional valve. If the oil volume is still insufficient, the auxiliary motor can be turned on, so that the auxiliary oil pump supplies oil to the hydraulic proportional valve through the first check valve and the first control switch valve group. When the working chamber needs to rapidly discharge oil to recover energy, the first control switch valve group can be opened and the second control switch valve group closed. After passing through the first control switch valve group, the high-pressure oil can flow to the forward and reverse oil pump. Due to the setting of the first check valve, it will not flow to the auxiliary oil pump. At this time, the forward and reverse oil pump can be driven to quickly reverse, so that the main motor can generate electricity. When energy recovery is inefficient, such as due to low potential energy or small return oil volume, the first control valve group can be closed and the second control valve group opened, allowing the oil returning from the hydraulic proportional valve to directly enter the oil tank. In this hydraulic circuit for lifting and recovering potential energy in an electric empty container stacker gantry, the use of two sets of motors and pumps rapidly increases oil supply capacity, avoiding the problem of inconsistency between return and supply energy. The two control valve groups allow for selective direct return oil based on energy characteristics and the working requirements of the working cylinder, without needing to pass through the forward and reverse pumps. This facilitates working cylinder adjustment and prevents inefficient operation of the forward and reverse cylinders. In summary, this hydraulic circuit for lifting and recovering potential energy in an electric empty container stacker gantry effectively solves the current problem of inconvenient energy recovery during working cylinder return oil.

[0009] Preferably, it further includes an electrically controlled proportional valve connected between the hydraulic proportional valve and the working interface, the electrically controlled proportional valve being used for unidirectional conduction on both sides during oil supply and conduction through a throttle valve during oil return.

[0010] Preferably, both the first control switch valve group and the second control switch valve group are electrically controlled combination valve groups. The electrically controlled combination valve group includes a hydraulically controlled directional valve connected to the main circuit and an electromagnetic directional valve for controlling the switching of the hydraulically controlled directional valve, so that when the electromagnetic directional valve is open, the hydraulically controlled directional valve can be hydraulically opened, and when the electromagnetic directional valve is closed, the hydraulically controlled directional valve is hydraulically deactivated to remain closed.

[0011] Preferably, the oil circuit between the forward and reverse oil pump and the first control switch valve group is guided to the oil tank through the main overflow valve.

[0012] Preferably, it further includes a second check valve arranged in parallel with the main overflow valve.

[0013] Preferably, it further includes a multi-way valve connected between the first check valve and the auxiliary oil pump.

[0014] Preferably, the multi-way valve includes a reversing valve connected between the auxiliary oil pump and the hydraulic proportional valve, and a proportional solenoid valve for driving the reversing valve to switch. When energized, the proportional solenoid valve enables the pressure oil in the pilot oil circuit of the multi-way valve to push the reversing valve to switch to the oil supply position to open the working oil circuit.

[0015] Preferably, the working interface is connected to the oil tank via a shut-off valve.

[0016] Preferably, the working interface is connected to the oil tank via a branch overflow valve.

[0017] Preferably, it includes two working interfaces to communicate with two working cylinders respectively, the hydraulic proportional valve is connected to the corresponding working interface through different electronically controlled proportional valves, and the two working interfaces are connected to each other through an interconnecting oil circuit and the interconnecting oil circuit is connected to the shut-off valve. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the hydraulic circuit for lifting and potential energy recovery of an electric empty container stacker gantry provided in an embodiment of the present invention;

[0020] Figure 2 for Figure 1 Enlarged structural schematic diagram of the valve assembly at point A;

[0021] Figure 3 for Figure 1 Enlarged structural schematic diagram of the valve assembly at point B;

[0022] Figure 4 for Figure 1 A magnified schematic diagram of a multi-way valve.

[0023] The following labels are shown in the attached diagram:

[0024] Working interface 1, working cylinder 2, forward and reverse oil pump 3, main motor 4, auxiliary oil pump 5, auxiliary motor 6, hydraulic proportional valve 7, first control switch valve group 8, second control switch valve group 9, electric proportional valve 10, oil tank 11, first check valve 12, second check valve 13, multi-way valve 14, shut-off valve 15, main line overflow valve 16, branch line overflow valve 17, hydraulic directional valve 18, solenoid directional valve 19. Detailed Implementation

[0025] This invention discloses a hydraulic circuit for lifting and recovering potential energy of an electric empty container stacker gantry, which effectively solves the problem of inconvenient energy recovery when the working cylinder returns oil.

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Please see Figures 1-4 , Figure 1 A schematic diagram of the hydraulic circuit for lifting and potential energy recovery of an electric empty container stacker gantry provided in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged structural schematic diagram of the valve assembly at point A; Figure 3 for Figure 1 Enlarged structural schematic diagram of the valve assembly at point B; Figure 4 for Figure 1 A magnified schematic diagram of a multi-way valve.

[0028] In one specific embodiment, this embodiment provides a hydraulic circuit for lifting the gantry and recovering potential energy of an electric empty container stacker. It is mainly used in electric empty container stackers. Specifically, the hydraulic circuit for lifting the gantry and recovering potential energy of an electric empty container stacker includes a working interface 1, a forward and reverse oil pump 3, a main motor 4, an auxiliary oil pump 5, an auxiliary motor 6, and a hydraulic proportional valve 7.

[0029] Working interface 1 is used to communicate with the working chamber of working cylinder 2, generally with the rodless chamber of working cylinder 2. When oil is supplied to working interface 1, it pushes the piston rod of working cylinder 2 to extend, so that the gantry rises. When the gantry descends, oil needs to be returned through working interface 1 so that the piston rod can retract. Specifically, working cylinder 2 can be used as a lifting cylinder.

[0030] The main motor 4 is mechanically connected to the forward and reverse oil pump 3. In electric mode, it drives the forward and reverse oil pump to supply oil. In power generation mode, the return oil can drive the forward and reverse oil pump to rotate and generate electricity. For example, when the main motor 4 is in electric mode, it drives the forward and reverse oil pump 3 to rotate forward to draw oil from the oil tank 11 and supply high-pressure oil at the supply port. When the main motor 4 is in electric mode, it drives the return oil pump 3 to rotate in the reverse direction to generate electricity. That is, when the main motor 4 is in power generation mode, the return oil drives the forward and reverse oil pump 3 to rotate in the reverse direction. The reverse-rotating forward and reverse oil pump 3 drives the power generation input shaft of the main motor 4 to rotate, so that the main motor 4 generates electricity.

[0031] The auxiliary motor 6 drives the auxiliary oil pump 5 to supply oil. The auxiliary motor 6 is not required to have a generator mode and is a low-power motor compared to the main motor 4. Similarly, the auxiliary oil pump 5 is a low-power oil pump compared to the forward and reverse oil pumps. It mainly plays a role in precisely adjusting the oil quantity of the working oil cylinder 2.

[0032] The hydraulic proportional valve 7 functions as a speed limiter and also acts as a throttling valve under the control of the pilot pressure oil. One port of the hydraulic proportional valve 7 is connected to the working interface 1, allowing it to supply oil to and receive return oil from the working interface 1. The other port of the hydraulic proportional valve 7 is connected to one port of the first control switch valve group 8 and is connected to the oil tank 11 through the second control switch valve group 9. This allows the return oil from the hydraulic proportional valve 7 to flow through either the first control switch valve group 8 or the second control switch valve group 9 back to the oil tank 11. The other port of the first control switch valve group 8 is connected to the forward and reverse oil pump 3 and is connected to the auxiliary oil pump 5 through the first check valve 12. This allows the auxiliary oil pump 5 to supply oil to the first control switch valve group 8 through the first check valve 12, while the return oil from the first control switch valve group 8 cannot pass through the first check valve 12.

[0033] In the hydraulic circuit used for lifting the gantry and recovering potential energy of the electric empty container stacker, the working interface 1 is connected to the working chamber of the working cylinder 2 during use. When the working chamber needs to be rapidly supplied with high-pressure oil, the main motor 4 starts working, the first control switch valve group 8 is opened, and the second control switch valve group 9 is closed. The forward and reverse oil pump 3 supplies a large amount of high-pressure oil into the working chamber through the hydraulic proportional valve 7. If the oil volume is still insufficient, the auxiliary motor 6 can be turned on so that the auxiliary oil pump 5 supplies oil to the hydraulic proportional valve 7 through the first check valve 12 and the first control switch valve group 8. When the working chamber needs to rapidly discharge oil to recover energy, the first control switch valve group 8 can be opened and the second control switch valve group 9 can be closed. After passing through the first control switch valve group 8, the high-pressure oil can flow to the forward and reverse oil pump 3. Due to the setting of the first check valve 12, it will not flow to the auxiliary oil pump 5. At this time, the forward and reverse oil pump 3 can be driven to quickly reverse, so that the main motor 4 can generate electricity. When energy cannot be efficiently recovered, such as due to low potential energy or small return oil volume, the first control switch valve group 8 can be closed and the second control switch valve group 9 can be opened, allowing the oil returning from the hydraulic proportional valve 7 to directly enter the oil tank 11. In this hydraulic circuit for lifting and recovering potential energy of the electric empty container stacker gantry, the installation of two sets of motors and pumps rapidly increases the oil supply capacity, avoiding the problem of incoordination between return oil and supply oil energy. Simultaneously, the installation of two control switch valve groups allows for selective direct return oil based on energy characteristics and the working requirements of the working cylinder 2, without passing through the forward and reverse pump 3. This facilitates the adjustment of the working cylinder 2 and avoids inefficient operation of the forward and reverse cylinders. In summary, this hydraulic circuit for lifting and recovering potential energy of the electric empty container stacker gantry effectively solves the current problem of inconvenient energy recovery during the return oil flow from the working cylinder 2.

[0034] Furthermore, this configuration preferably also includes an electronically controlled proportional valve 10, which is connected between the hydraulically controlled proportional valve 7 and the working interface 1. The electronically controlled proportional valve 10 is used for unidirectional flow on both sides during oil supply and for flow return via a throttle valve. That is, when oil supply is required, it is driven to flow unidirectionally, ensuring that the hydraulically controlled proportional valve 7 can only supply oil to the working interface 1, preventing oil from returning from the working interface 1 to the hydraulically controlled proportional valve 7. This effectively ensures that during oil supply, the hydraulically controlled proportional valve 7 will not experience rapid pressure loss in the working chamber due to sudden pressure loss. During flow return, the throttle valve connects the working interface 1 and the hydraulically controlled proportional valve 7 to control the flow rate. Specifically, the electronically controlled proportional valve 10 can be a two-position, two-way directional valve, with one control position connected to both ports via a one-way valve core and the other control position connected to both ports via a throttle valve.

[0035] Furthermore, for ease of switching control, it is preferable that both the first control switch valve group 8 and the first control switch valve group 8 are electrically controlled combination valve groups. The electrically controlled combination valve group includes a hydraulically controlled directional valve 18 connected to the main circuit and an electromagnetic directional valve 19 for controlling the switching of the hydraulically controlled directional valve 18. When the electromagnetic directional valve 19 is open, the hydraulically controlled directional valve 18 can be hydraulically opened, meaning that one side of the oil passage of the hydraulically controlled directional valve 18 valve core is connected to the oil tank 11, allowing the valve core to move in opposite directions. The hydraulically controlled directional valve 18 is a bidirectional hydraulically controlled valve, meaning that when the oil pressure difference between one side and the other side reaches a set value, both ports are open; otherwise, both ports are closed, allowing for hydraulic control of opening and closing. When the electromagnetic directional valve 19 is closed, the hydraulically controlled directional valve 18 fails to operate and remains closed. That is, the oil passage on that side of the hydraulically controlled directional valve 18 valve core is no longer connected to the oil tank 11, and contains hydraulic oil, thus preventing the valve core from moving in opposite directions. Specifically, the first control valve assembly 8 includes a first hydraulic directional valve and a first solenoid directional valve. One port of the first hydraulic directional valve is connected to the hydraulic proportional valve 7, and the other port is connected to the first check valve 12 and the forward / reverse oil pump 3. The second control valve assembly 9 includes a second hydraulic directional valve and a second solenoid directional valve. One port of the first hydraulic directional valve is connected to the hydraulic proportional valve 7, and the other port is connected to the oil tank 11. It should be noted that the connection in this context can be a direct connection through a pipeline or a connection through other valves or functional components.

[0036] Furthermore, to avoid excessive pressure at the outlet of the reversible oil pump 3, it is preferable that the oil circuit between the reversible oil pump 3 and the first control switch valve group 8 is guided to the oil tank 11 through the main overflow valve 16. Correspondingly, a second check valve 13 can also be provided in parallel with the main overflow valve 16. This ensures the safety of the oil circuit and prevents damage to the reversible oil pump 3 and the first control switch valve group 8.

[0037] Furthermore, this configuration preferably also includes a multi-way valve 14 connected between the first check valve 12 and the auxiliary oil pump 5, so that the other directional valve ports of the multi-way valve 14 can also meet other operational requirements. The multi-way valve 14 has a smaller flow rate, which facilitates the replenishment of oil to the hoisting main circuit. Moreover, when a small-amplitude movement control of the high gantry is required, it can be achieved through the control of the multi-way valve 14 with its smaller flow rate.

[0038] Furthermore, for ease of control, the multi-way valve 14 preferably includes a multi-way directional valve connected between the auxiliary oil pump 5 and the hydraulic proportional valve 7, and a proportional solenoid valve for driving the multi-way directional valve to switch. When energized, the proportional solenoid valve enables the pressure oil in the pilot oil circuit of the multi-way valve 14 to push the multi-way directional valve to switch to the oil supply position to open the working oil circuit.

[0039] Furthermore, considering that even with a large flow rate in the control valve assembly, it is still difficult to achieve a rapid unloading effect, it is preferable that the working interface 1 is connected to the oil tank 11 via the shut-off valve 15. When the working cylinder 2 needs to descend in an emergency, the required descent speed of the working cylinder 2 is obtained by manually controlling the valve core opening of the shut-off valve 15, thus achieving emergency descent.

[0040] Furthermore, to prevent excessive oil pressure at the working interface 1 from damaging components such as the cylinder block and valves in the oil circuit, it is preferable that the working interface 1 is connected to the oil tank 11 via a branch relief valve 17. That is, the oil circuit between the working interface 1 and the electronically controlled proportional valve 10 is connected to the oil tank 11 via the branch relief valve 17, which acts as a safety valve to release pressure when the oil pressure is too high.

[0041] In practical work, two working cylinders 2 are generally set, that is, two lifting cylinders are generally set. Based on this, it is preferred to include two working interfaces 1 to be connected to the two working cylinders 2 respectively. The hydraulic proportional valve 7 is connected to the corresponding working interface 1 through different electronically controlled proportional valves 10. It is also preferred that the two working interfaces 1 are connected through an interconnecting oil circuit to ensure that the two working cylinders 2 work synchronously. It is also preferred that the interconnecting oil circuit is connected to the aforementioned shut-off valve 15 to facilitate rapid and simultaneous unloading.

[0042] In another specific embodiment, this embodiment provides a schematic diagram of the hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker. It includes: a second check valve 13, a main relief valve 16, a first check valve 12, a first hydraulically controlled directional valve, a second hydraulically controlled directional valve, a first solenoid directional valve, a second solenoid directional valve, a hydraulically controlled proportional valve 7, a shut-off valve 15, an electrically controlled proportional valve 10 (first electrically controlled proportional valve, second electrically controlled proportional valve), a branch relief valve 17 (first branch relief valve, second branch relief valve), a lifting cylinder, a multi-way valve 14, an auxiliary oil pump 5, an auxiliary motor 6, a forward / reverse oil pump 3, a main motor 4, and an oil tank 11. The lifting cylinder is rigidly connected to the gantry. The multi-way valve 14 includes a first proportional solenoid valve, a second proportional solenoid valve, a multi-way directional valve, and the main motor 4 can switch between electric motor mode and generator mode.

[0043] When the lifting cylinder needs to lift, the motor in electric motor mode rotates, driving the forward and reverse oil pump 3 to rotate. The forward and reverse oil pump 3 draws oil from the oil tank 11, providing pressurized oil to the system. The main line relief valve 16 functions as a safety valve. When the pressurized oil reaches the first hydraulic directional valve, it is in the upper position (shutdown) when the first and second hydraulic directional valves are not working, and in the lower position (shutdown) when the coils of the first and second solenoid directional valves are not energized. At this time, the coil of the first solenoid directional valve is energized, and the first solenoid directional valve is in the upper position, opening the oil circuit. Under the action of the pressurized oil, the first hydraulic directional valve changes to the lower position, opening the oil circuit. Then the pressurized oil passes through the hydraulic proportional valve 7, reaching the first and second solenoid proportional valves respectively. The hydraulic proportional valve 7 functions as a speed limiter. The coils of the first and second electrically controlled proportional valves are not energized, therefore both valves are in the right-hand position, with unidirectional oil flow. Pressurized oil enters the rodless chamber of the lifting cylinder, causing the gantry to lift. The rodless chambers of the two lifting cylinders are connected by a pipeline to ensure that the lifting speeds of both cylinders are the same. The first and second branch relief valves function as safety valves to prevent excessive pressure in the rodless chamber of the lifting cylinders. For high gantry lifting, the single forward / reverse pump 3 cannot meet the lifting flow requirements; therefore, an auxiliary pump 5 is needed to supplement the pressurized oil. The auxiliary motor 6 rotates, driving the auxiliary oil pump 5 to rotate. The auxiliary oil pump 5 draws oil from the oil tank 11, providing pressurized oil to the system. This pressurized oil first enters the multi-way valve 14. When the coil of the second proportional solenoid on the multi-way valve 14 is energized, the pressurized oil entering the pilot oil circuit will cause the multi-way directional valve on the multi-way valve 14 to move to the upper position. The pressurized oil in the main oil circuit will flow out from port A of the multi-way valve 14 and reach the first check valve 12. After passing through the first check valve 12, the pressurized oil merges with the other pressurized oil. At the same time, the other directional valve ports of the multi-way valve 14 can also meet other working requirements. The flow rate of the multi-way valve 14 is relatively small, serving to replenish the oil in the hoisting main circuit.

[0044] When the lifting cylinder needs to descend, the coils of the first and second electro-pneumatic proportional valves are energized, causing them to move to the left position, opening the oil circuit and throttling the flow. Simultaneously, the hydraulically controlled proportional valve 7, under the control of the pilot pressure oil, also functions as a throttling device. The pressurized oil in the rodless chamber of the lifting cylinder enters the oil circuit, passing sequentially through the first and second electro-pneumatic proportional valves, and then the hydraulically controlled proportional valve 7. One path of pressurized oil reaches the first hydraulically controlled directional valve, and the other path reaches the second hydraulically controlled directional valve. When the coils of the first and second electro-pneumatic directional valves are de-energized, they are in the upper position, effectively shutting off the flow. When the coil of the first solenoid directional valve is energized and the coil of the second solenoid directional valve is de-energized, the first hydraulic directional valve will be in the lower position, opening the oil circuit, while the second hydraulic directional valve will remain in the upper position, acting as a shut-off valve. The pressurized oil passes through the first hydraulic directional valve and reaches the reversible oil pump 3, causing it to reverse, thereby driving the generator motor to rotate, generating electrical energy, achieving potential energy recovery, and lowering the gantry. When the coil of the first solenoid directional valve is de-energized and the coil of the second solenoid directional valve is energized, the first hydraulic directional valve remains in the upper position, acting as a shut-off valve, while the second hydraulic directional valve will be in the lower position, opening the oil circuit. The pressurized oil passes through the second hydraulic directional valve and returns to the oil tank 11.

[0045] When the lifting cylinder needs to be lowered in an emergency, since the rodless chambers of the two lifting cylinders are connected by a pipeline, the required lowering speed of the lifting cylinder can be obtained by manually controlling the valve core opening of the shut-off valve 15, thus achieving emergency lowering.

[0046] The specific power supply details are shown in Table 1 below:

[0047]

[0048] The solenoid coil of the first solenoid directional valve 19 is SV1; the solenoid coil of the second solenoid directional valve 19 is SV2; the solenoid coil of the first solenoid proportional valve 10 is SV3; the solenoid coil of the second solenoid proportional valve 10 is SV4; the solenoid coil of the first proportional solenoid valve on the multi-way valve 14 is SV5; the solenoid coil of the second proportional solenoid valve on the multi-way valve 14 is SV6; "1" indicates a high level coil, and "0" indicates a low level coil.

[0049] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0050] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker, characterized in that, include: The working interface is used to connect to the working chamber of the hydraulic cylinder. Forward and reverse oil pumps; The main motor is mechanically connected to the forward and reverse oil pump to drive the forward and reverse oil pump to work in electric mode for oil supply, and to drive the forward and reverse oil pump to rotate for power generation in power generation mode by returning oil. Auxiliary oil pump; An auxiliary motor drives the auxiliary oil pump to supply oil. The hydraulic proportional valve has one side connected to the working interface and the other side connected to one port of the first control switch valve group and connected to the oil tank through the second control switch valve group. The other port of the first control switch valve group is connected to the forward and reverse oil pump and connected to the auxiliary oil pump through the first check valve, so that the auxiliary oil pump can supply oil to the first control switch valve group. When the oil supply from the forward and reverse oil pump is insufficient, the auxiliary oil pump can supply oil to the hydraulic proportional valve. The power of the auxiliary motor is less than the power of the main motor; The power of the auxiliary oil pump is less than the power of the forward and reverse oil pumps.

2. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 1, characterized in that, It also includes an electrically controlled proportional valve connected between the hydraulic proportional valve and the working interface. The electrically controlled proportional valve is used to open the one-way valve structure on both sides when supplying oil and to open through the throttle valve when returning oil.

3. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 2, characterized in that, Both the first and second control switch valve groups are electrically controlled combination valve groups. The electrically controlled combination valve group includes a hydraulically controlled directional valve connected to the main circuit and a solenoid directional valve for controlling the switching of the hydraulically controlled directional valve, so that when the solenoid directional valve is open, the hydraulically controlled directional valve can be hydraulically opened, and when the solenoid directional valve is closed, the hydraulically controlled directional valve is hydraulically deactivated to remain closed.

4. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 3, characterized in that, The oil circuit between the forward and reverse oil pump and the first control switch valve group is guided to the oil tank through the main overflow valve.

5. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 4, characterized in that, It also includes a second check valve connected in parallel with the main overflow valve.

6. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 3, characterized in that, It also includes a multi-way valve connected between the first check valve and the auxiliary oil pump.

7. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 6, characterized in that, The multi-way valve includes a reversing valve connected between the auxiliary oil pump and the hydraulic proportional valve, and a proportional solenoid valve for driving the reversing valve to switch. When energized, the proportional solenoid valve enables the pressure oil in the pilot oil circuit of the multi-way valve to push the reversing valve to switch to the oil supply position to open the working oil circuit.

8. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to any one of claims 2-7, characterized in that, The working interface is connected to the oil tank via a shut-off valve.

9. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 8, characterized in that, The working interface is connected to the oil tank via a branch overflow valve.

10. The hydraulic circuit for lifting and potential energy recovery of the gantry of an electric empty container stacker according to claim 9, characterized in that, It includes two working interfaces for communicating with two working cylinders respectively. The hydraulic proportional valve is connected to the corresponding working interface through different electronically controlled proportional valves. The two working interfaces are connected by an interconnecting oil circuit, and the interconnecting oil circuit is connected to the shut-off valve.

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