Energy recovery electro-hydraulic proportional multi-way valve with floating control

Abstract

The invention provides an energy recovery electro-hydraulic proportional multi-way valve with a floating control function. Comprising a valve body, a movable arm valve rod, at least one functional valve rod, a hydraulic pump, a main overflow valve and a proportional electromagnetic valve, wherein the movable arm valve rod and the functional valve rod are arranged in the valve body; the hydraulic pump is used for providing hydraulic oil; the main overflow valve is arranged on an oil inlet path between the hydraulic pump and the movable arm valve rod; the movable arm valve rod is configured to be a four-position valve rod with four working positions, and the four working positions comprise a floating position, a descending regeneration position, a middle position and a lifting position; when the movable arm valve rod is located at the descending regeneration position, return oil discharged from a rod cavity of the movable arm oil cylinder forms two branches, wherein the first branch flows to a rodless cavity of the movable arm oil cylinder through a regeneration runner arranged in the movable arm valve rod; and the second branch flows to the oil inlet of the functional valve rod through the proportional electromagnetic valve, so that the descending potential energy of the movable arm is efficiently recycled, and the energy-saving efficiency of the hydraulic system and the control smoothness of the composite action are remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of skid steer loader equipment, and specifically to an energy recovery electro-hydraulic proportional multi-way valve with floating control. Background Technology

[0002] Skid steer loaders, as a type of multi-functional construction machinery, are widely used in municipal maintenance and confined space operations due to their small size, flexible operation, and small turning radius. The fixed displacement pump hydraulic system of small and medium tonnage skid steer loaders typically employs an open-center multi-way valve control architecture. While this structure is relatively simple and cost-effective, it presents significant technical bottlenecks in actual operational cycles.

[0003] On the one hand, traditional open-center multi-way valves often employ sequential hydraulic circuit structures. When the first linkage (such as the boom linkage) operates first, subsequent linkages (such as the bucket or attachment linkage) often experience lag or even stall due to insufficient oil supply. This results in insufficient flexibility for operators when performing common compound actions such as "boom lifting and bucket retraction" or "boom lowering and unloading." Existing technologies, such as CN118391315A, propose a multi-way valve, hydraulic system, and engineering machinery that uses a combination of tilting cylinder directional valves, lifting cylinder directional valves, and auxiliary directional valves to achieve compound actions of different linkages through changes in valve core position. However, during combined operations, the hydraulic oil discharged by the actuator flows directly back to the oil tank, resulting in energy waste and failing to fundamentally solve the energy management problem during compound actions.

[0004] On the other hand, due to the relatively large weight of the boom working device, there is usable gravitational potential energy during the boom descent. For example, CN112049181A discloses an excavator energy regeneration system and control method, which realizes the recovery and reuse of boom descent potential energy and slewing braking kinetic energy by connecting an energy regeneration circuit containing multiple electro-hydraulic proportional directional valves, an accumulator, and multi-stage branches in parallel to the original hydraulic system. However, the hydraulic circuit connection and control system are more complex, increasing manufacturing costs, troubleshooting difficulty, and maintenance costs. At the same time, its energy recovery and reuse requires transfer through the accumulator, and there is a certain amount of energy loss in each energy recovery and reuse process, resulting in a still low secondary energy utilization rate.

[0005] Furthermore, skid steer loaders rely heavily on the "floating" function of the boom (i.e., unloading in both chambers of the hydraulic cylinder, allowing it to extend and retract freely with the undulations of the ground) when performing leveling operations. Existing solutions such as CN221220988U can achieve floating unloading through valve core displacement, but this is a passive energy-saving method. Moreover, the implementation of the floating function often requires the addition of extra valve blocks or complex mechanical linkage mechanisms, which conflicts with the limited installation space of skid steer loaders. Summary of the Invention

[0006] The purpose of this invention is to provide an energy recovery electro-hydraulic proportional multi-way valve with floating control, which integrates multiple functions such as floating control, energy recovery, proportional regulation and anti-suction oil replenishment on a single valve stem, thereby improving the energy efficiency of the hydraulic system and the smoothness of operation of complex actions.

[0007] This application is achieved through the following technical solution, specifically: An energy recovery electro-hydraulic proportional multi-way valve with floating control includes a valve body, a boom valve stem and at least one functional valve stem disposed in the valve body, a hydraulic pump for supplying hydraulic oil, and a main relief valve disposed on the oil inlet path between the hydraulic pump and the boom valve stem. It also includes a proportional solenoid valve, which is disposed between the return oil passage of the boom valve stem and the inlet oil passage of the functional valve stem; The boom valve stem is configured as a four-position valve stem with four working positions, including a floating position, a descent regeneration position, a neutral position, and a lifting position. When the boom valve stem is in the descent regeneration position, the return oil discharged from the rod chamber of the boom cylinder forms two branches: the first branch flows to the rodless chamber of the boom cylinder through the regeneration channel provided inside the boom valve stem; the second branch flows to the oil inlet of the functional valve stem through the proportional solenoid valve.

[0008] As an improvement of this application, when the boom valve rod is in the floating position, the oil inlet of the hydraulic pump is directly connected to the next functional valve rod, and at the same time, the boom valve rod controls the rodless chamber and the rod chamber of the boom cylinder to be connected to the return oil tank, so that the boom is in a floating state.

[0009] As an improvement to this application, the regeneration channel includes an axial hole formed inside the boom valve stem and a built-in check valve disposed in the axial hole; When in the descending regeneration position, the high-pressure return oil from the rod chamber enters the axial hole through the valve stem radial hole, and flows into the oil port communicating with the rodless chamber after passing through the built-in check valve.

[0010] Furthermore, the valve body is also provided with an external regeneration check valve, which cooperates with the built-in check valve to restrict the flow of oil from the rod chamber to the rodless chamber for one-way oil replenishment.

[0011] As an improvement of this application, a first working oil port, a second working oil port and a third working oil port are provided on the valve body at the position corresponding to the boom valve stem; The first working oil port is connected to the rodless chamber of the boom cylinder, the third working oil port is connected to the rod chamber of the boom cylinder, the second working oil port is used to connect to the oil inlet of the next functional valve stem, and the fourth oil inlet is used to connect to the return oil tank.

[0012] Furthermore, the valve body is provided with a first oil inlet, a second oil inlet, a third oil inlet, and a fourth oil inlet at the position corresponding to the boom valve stem; When the boom valve stem is in the floating position, the second oil inlet is connected to the second working oil inlet, and the first working oil inlet and the third working oil inlet are simultaneously connected to the fourth oil inlet. When the boom valve stem is in the lowering regeneration position, the first oil inlet is connected to the first working oil inlet, and the third oil inlet is connected to the third working oil inlet; When the boom valve stem is in the neutral position, the second oil inlet is connected to the second working oil inlet, and the first oil inlet, the third oil inlet, the fourth oil inlet, the first working oil inlet, and the third working oil inlet are not connected to each other; When the boom valve stem is in the lifting position, the first oil inlet is connected to the third working oil inlet, the third oil inlet is connected to the first working oil inlet, and the second oil inlet, the fourth oil inlet, and the second working oil inlet are in the closed state.

[0013] Furthermore, the oil inlet of the proportional solenoid valve is connected to the third oil inlet, and the oil outlet is connected to the oil inlet channel of the functional valve stem, which is used to adjust the valve opening according to the working state or load pressure signal of the functional valve stem and control the flow ratio allocated to the functional valve stem.

[0014] As an improvement to this application, the valve body is also provided with an oil inlet check valve; The oil inlet check valve is installed between the hydraulic pump and the oil inlet channel of the boom valve stem to prevent oil from flowing back from the boom valve stem to the hydraulic pump.

[0015] As an improvement to this application, the valve body is also provided with a replenishing check valve; One end of the replenishing check valve is connected to the return oil tank, and the other end is connected to the rodless chamber flow channel of the boom cylinder. It is used to replenish hydraulic oil from the return oil tank to the rodless chamber when negative pressure is generated in the rodless chamber of the boom cylinder.

[0016] As an improvement of this application, a secondary overflow valve is also provided in parallel on the flow channel corresponding to the boom valve stem to limit the maximum pressure in the working chamber of the boom cylinder.

[0017] The beneficial effects of this application are as follows: 1. The solution of this application sets a proportional solenoid valve between the return oil passage of the boom valve rod and the inlet oil passage of the functional valve rod. When the boom valve rod is in the descending regeneration position, it can guide the high-pressure oil discharged from the rod chamber of the boom cylinder to the functional valve rod. This allows the energy that would otherwise flow directly back to the oil tank to be directly recovered and used to drive other actuators, thereby reducing the output power requirement of the hydraulic pump and significantly improving the energy utilization rate of the hydraulic system.

[0018] 2. The solution proposed in this application utilizes the adjustable opening characteristic of a proportional solenoid valve, enabling the system to control the flow ratio to the functional valve stem according to actual working conditions. Compared to traditional on / off or fixed throttling regeneration, this solution achieves flexible control of the regenerated flow, ensuring the smoothness of boom descent while providing appropriate hydraulic power to the functional valve stem based on load requirements. This improves the operational coordination of excavators and other construction machinery when boom descent is combined with other actions.

[0019] 3. The solution proposed in this application achieves floating function by adding a stop to the valve core and using a proportional solenoid valve to depressurize the two working oil chambers of the boom cylinder, thus avoiding the traditional complex mechanical structure.

[0020] 4. The solution proposed in this application employs a dual-branch flow design when the boom valve rod is in the descending regeneration position. The first branch directly replenishes oil to the rodless chamber of the boom cylinder through an internal regeneration channel. This self-regeneration mechanism prioritizes the filling needs of the rodless chamber, effectively preventing cavitation caused by rapid boom descent, and ensuring the smooth operation and service life of the hydraulic cylinder.

[0021] In addition to the technical problems solved by the present invention, the technical features constituting the technical solutions, and the advantages brought about by the technical features of these technical solutions as described above, other technical problems that the present invention can solve, other technical features contained in the technical solutions, and the advantages brought about by these technical features will be further described in detail with reference to the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a hydraulic system with a floating control-equipped electro-hydraulic proportional multi-way valve for energy recovery, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the oil port distribution of the boom valve stem provided in an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the internal flow channel structure when the boom valve stem is in the descending regeneration position, as provided in an embodiment of the present invention. Figure 4 This is a schematic cross-sectional view of the flow channel structure when the boom valve stem is in the lifting position, as provided in an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures: 1. Boom valve stem; 2. Functional valve stem; 3. Hydraulic pump; 4. Main relief valve; 5. Proportional solenoid valve; 6. Axial bore; 7. Built-in check valve; 8. External regeneration check valve; 9. First working port; 10. Second working port; 11. Third working port; 12. Fourth inlet port; 13. First inlet port; 14. Second inlet port; 15. Third inlet port; 16. Inlet check valve; 17. Replenishment check valve; 18. Secondary relief valve; 19. Solenoid directional valve; A1. Rodless chamber; B1. Rod chamber. Detailed Implementation

[0024] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] In view of the problems existing in the background technology or products, Figure 1 This is a schematic diagram of a hydraulic system with a floating control-equipped electro-hydraulic proportional multi-way valve for energy recovery, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the oil port distribution of the boom valve stem provided in an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the internal flow channel structure when the boom valve stem is in the descending regeneration position, as provided in an embodiment of the present invention. Figure 4 This is a schematic cross-sectional view of the flow channel structure when the boom valve stem is in the lifting position, as provided in an embodiment of the present invention.

[0026] Reference Figures 1 to 4 This application provides an energy recovery electro-hydraulic proportional multi-way valve with floating control, including a valve body, a boom valve stem 1 and at least one functional valve stem 2 disposed in the valve body, a hydraulic pump 3 for supplying hydraulic oil, and a main relief valve 4 disposed on the oil inlet path between the hydraulic pump 3 and the boom valve stem 1. It also includes a proportional solenoid valve 5, which is disposed between the oil return passage of the boom valve stem 1 and the oil inlet passage of the functional valve stem 2. The boom valve stem 1 is configured as a four-position valve stem with four working positions, including a floating position, a descent regeneration position, a neutral position, and a lifting position. When the boom valve stem 1 is in the descent regeneration position, the return oil discharged from the rod chamber B1 of the boom cylinder forms two branches: the first branch flows through the regeneration channel provided inside the boom valve stem 1 to the rodless chamber A1 of the boom cylinder; the second branch flows through the proportional solenoid valve 5 to the oil inlet of the functional valve stem 2.

[0027] Specifically, when the boom valve stem 1 is in the descending regeneration position, due to gravity, the high-pressure oil discharged from the rod chamber B1 of the boom cylinder does not flow directly back to the oil tank, but is diverted for reuse. This portion of the returned oil is divided into two parts: one part enters the regeneration flow channel inside the boom valve stem 1 and flows into the oil port communicating with the rodless chamber A1, thereby realizing the self-regeneration and replenishment of the boom cylinder and preventing the rodless chamber A1 from sucking in cavitation.

[0028] Another portion of the returned oil is guided to the inlet of the functional valve stem 2 via the proportional solenoid valve 5. In this way, when the functional valve stem 2 operates simultaneously (such as performing compound actions such as "boom lifting + bucket retraction" or "boom lowering + bucket unloading"), the recovered energy can be utilized to reduce the output power of the hydraulic pump 3 and achieve energy saving.

[0029] This embodiment makes full use of the gravitational potential energy during boom descent through a unique hydraulic circuit design, achieving efficient recovery and reuse of the boom descent potential energy.

[0030] Preferably, the boom valve stem 1 is driven by two solenoid directional valves 19 at each end. By controlling the energizing state and current magnitude of the two solenoid directional valves 19, the boom valve stem 1 can be positioned in four different working positions.

[0031] Continue reading Figure 3 In one implementation, the regeneration channel includes an axial hole 6 formed inside the boom valve stem 1 and a built-in check valve 7 disposed in the axial hole. When in the descending regeneration position, the high-pressure return oil from the rod chamber B1 enters the axial hole 6 through the valve stem radial hole, and flows into the oil port communicating with the rodless chamber A1 after passing through the built-in check valve 7.

[0032] Specifically, such as Figure 3 As shown, the boom valve stem 1 has a hollow structure design, and the axial hole 6 penetrates the central part of the boom valve stem 1 to form a return oil channel. The built-in one-way valve 7 is set inside the axial hole 6, which only allows oil to flow from the rod chamber B1 of the boom cylinder to the rodless chamber A1, while preventing reverse flow.

[0033] When the valve stem is in the descending regeneration position, the radial oil passage on the valve stem aligns with the return oil flow channel of the rod chamber B1 on the valve body. High-pressure return oil enters the axial hole 6 inside the valve core, pushing open the built-in check valve 7 under oil pressure. The oil flows through the inside of the valve core to the radial hole corresponding to the rodless chamber A1, and finally merges into the rodless chamber A1 of the boom cylinder. This built-in structure is compact and eliminates the need for additional complex valve blocks or pipelines outside the valve body.

[0034] Continue reading Figure 2In one implementation, when the boom valve stem 1 is in the floating position, the oil inlet of the hydraulic pump 3 is directly connected to the next functional valve stem 2, and at the same time, the boom valve stem 1 controls the rodless chamber A1 and the rod chamber B1 of the boom cylinder to be connected to the return oil tank, so that the boom is in a floating state.

[0035] Specifically, when the boom valve stem 1 is in its highest working position, i.e., the floating position, the internal oil circuit design of the boom valve stem 1 allows the hydraulic pump 3 to directly deliver pressurized oil to the next functional valve stem 2, without consuming power during boom operation. Simultaneously, the boom valve stem 1 connects the rodless chamber A1 and the rod chamber B1 of the boom cylinder. In this state, both chambers of the boom cylinder are unloaded and do not build up pressure, allowing the boom to rise and fall freely under external loads, thus achieving contour-following leveling operations that follow the undulations of the ground without the need for frequent manual adjustments.

[0036] Preferably, the valve body is further provided with an external regeneration check valve 8, which cooperates with the built-in check valve 7 to restrict the flow of oil from the rod chamber B1 to the rodless chamber A1 for one-way oil replenishment.

[0037] Specifically, the external regeneration check valve 8 is connected in parallel with the return oil flow channel of the rod chamber B1 of the boom cylinder, providing another regeneration return oil path at the hydraulic system level. Its configuration, together with the built-in check valve 7 inside the boom valve stem 1, further ensures unidirectional flow of oil from the rod chamber B1 to the rodless chamber A1 under specific operating conditions, and controls the regeneration flow rate at the system level.

[0038] Continue reading Figure 2 In one implementation, the valve body is provided with a first working oil port 9, a second working oil port 10 and a third working oil port 11 at the position corresponding to the boom valve stem 1; The first working oil port 9 is connected to the rodless chamber A1 of the boom cylinder, the third working oil port 11 is connected to the rod chamber B1 of the boom cylinder, the second working oil port 10 is used to connect to the oil inlet of the next functional valve stem 2, and the fourth oil inlet 12 is used to connect to the return oil tank.

[0039] Specifically, such as Figure 2 As shown, the first working port 9 is connected to the outlet of the rodless chamber A1 of the boom cylinder. When the rodless chamber A1 needs to be filled or drained, the oil flows through this port. The third working port 11 is connected to the outlet of the rod chamber B1 of the boom cylinder and is used for the filling or returning of the rod chamber B1. The first working port 9 and the third working port 11 are located on both sides of the valve stem axis, which facilitates the connection of the cylinder pipeline.

[0040] The second working oil port 10 serves as the core interface of the series oil circuit and is connected to the oil inlet channel of the boom valve stem 1. It is mainly used to directly deliver the pressure oil from the hydraulic pump 3 to the next functional valve stem 2 when the boom valve stem 1 is in certain specific working conditions (such as the neutral or floating position), so as to realize the series-parallel compound action.

[0041] The fourth oil inlet 12 is a return oil inlet, used to guide the return oil in the system to the return oil tank, including the return oil from the boom cylinder and the leakage oil inside the valve body.

[0042] The design and layout of these oil ports enable the boom valve stem 1 to flexibly control the movement of the boom cylinder and realize energy recovery and multi-connection sharing functions.

[0043] Continue reading Figure 2 The valve body is also provided with a first oil inlet 13, a second oil inlet 14, a third oil inlet 15, and a fourth oil inlet 12 at the position corresponding to the boom valve stem 1; When the boom valve stem 1 is in the floating position, the second oil inlet 14 is connected to the second working oil inlet 10, and the first working oil inlet 9 and the third working oil inlet 11 are simultaneously connected to the fourth oil inlet 12. When the boom valve stem 1 is in the lowering regeneration position, the first oil inlet 13 is connected to the first working oil inlet 9, and the third oil inlet 15 is connected to the third working oil inlet 11. When the boom valve stem 1 is in the neutral position, the second oil inlet 14 is connected to the second working oil inlet 10, and the first oil inlet 13, the third oil inlet 15, the fourth oil inlet 12, the first working oil inlet 9 and the third working oil inlet 11 are not connected to each other. When the boom valve stem 1 is in the lifting position, the first oil inlet 13 is connected to the third working oil inlet 11, the third oil inlet 15 is connected to the first working oil inlet 9, and the second oil inlet 14, the fourth oil inlet 12 and the second working oil inlet 10 are in the closed state.

[0044] Specifically, the first oil inlet 13 is a pressure oil inlet leading to the rodless chamber A1 of the boom cylinder, the second oil inlet 14 is a pressure oil inlet leading to the next connecting function valve rod 2, and the third oil inlet 15 is a pressure oil inlet leading to the rod chamber B1 of the boom cylinder.

[0045] These oil inlets cooperate with the aforementioned working oil inlets and return oil inlets to control the flow direction of the oil by adjusting the position of the boom valve stem 1: When the boom valve stem 1 is in the floating position, the oil from the hydraulic pump 3 enters the second working port 10 through the second inlet port 14 and directly connects to the next function valve stem 2. Meanwhile, the A1 and B1 chambers of the boom cylinder are connected to the fourth inlet port 12 (return tank) through the first working port 9, the third working port 11, and the fourth working port 12. When the boom valve stem 1 is in the lowering regeneration position, the oil from the hydraulic pump 3 enters the first working oil port 9 through the first oil inlet 13 to supply oil to the A1 chamber, while the return oil from the B1 chamber enters the regeneration flow channel through the third working oil port 11, part of which is regenerated to the A1 chamber and part of which flows to the functional valve stem 2 through the proportional solenoid valve 5. When the boom valve stem 1 is in the neutral position, the oil from the hydraulic pump 3 also flows through the second inlet 14 into the second working port 10 and down to the next function valve stem 2, while all ports related to the boom cylinder are closed and the boom cylinder stops working. When the boom valve 1 is in the lifting position, the hydraulic pump 3 supplies oil to chamber B1 by entering the third working port 11 through the first oil inlet 13. At the same time, the return oil from chamber A1 enters the first working port 9 through the third oil inlet 15, and is then distributed to the next working device or return oil tank via the proportional solenoid valve 5.

[0046] This multi-position valve stem design, combined with the flexible configuration of the oil inlet and working oil inlet, enables efficient control and energy management under complex operating conditions.

[0047] Preferably, the oil inlet of the proportional solenoid valve 5 is connected to the third oil inlet 15, and the oil outlet is connected to the oil inlet channel of the functional valve stem 2, which is used to adjust the valve opening according to the working state or load pressure signal of the functional valve stem 2 and control the flow ratio allocated to the functional valve stem 2.

[0048] Specifically, the proportional solenoid valve 5 receives a current signal from the controller. The controller monitors the pilot operation signal or load pressure of the functional valve stem 2 in real time. This electro-hydraulic proportional control method avoids the uncontrollable flow problem of traditional one-way valve recovery and significantly improves the smoothness of operation and fuel economy during compound actions.

[0049] For example, when the functional valve stem 2 is not activated (in the neutral position), energy recovery does not need to be allocated. The controller controls the proportional solenoid valve 5 to be fully closed or kept at the minimum opening. At this time, the return oil from chamber B1 mainly flows to chamber A1 through the internal check valve to achieve rapid descent and replenishment of oil.

[0050] When the functional valve stem 2 is activated (e.g., when the bucket is retracted), the controller adjusts the current of the proportional solenoid valve 5 according to demand, increasing the valve opening. At this time, the high-pressure return oil in chamber B1 is diverted, with one part entering chamber A1 and the other part flowing through the proportional solenoid valve 5 to the oil inlet of the functional valve stem 2, driving the bucket to move.

[0051] Optionally, the valve body is further provided with an inlet check valve 16; the inlet check valve 16 is located between the hydraulic pump 3 and the inlet flow channel of the boom valve stem 1, and is used to prevent oil from flowing back from the boom valve stem 1 to the hydraulic pump 3. This prevents the boom from momentarily "nodding" or sinking due to the load pressure being higher than the pump pressure when the load is heavy and the pump pressure of the hydraulic pump 3 has not yet been established.

[0052] Optionally, the valve body is also provided with a replenishing oil check valve 17; one end of the replenishing oil check valve 17 is connected to the return oil tank, and the other end is connected to the flow channel of the rodless chamber A1 of the boom cylinder, for replenishing hydraulic oil from the return oil tank to the rodless chamber A1 when negative pressure is generated in the rodless chamber A1 of the boom cylinder.

[0053] When the rodless chamber A1 of the boom cylinder experiences a momentary negative pressure during high-speed descent or under external load, the oil replenishment check valve 17 will automatically open, drawing oil from the return oil tank to replenish the rodless chamber A1, preventing the cylinder from sucking in cavitation, thereby avoiding the impact, noise, and damage to the cylinder and seals caused by cavitation, and ensuring the smoothness and continuity of the boom's movement.

[0054] Optionally, a secondary relief valve 18 is also connected in parallel on the flow channel corresponding to the boom valve stem 1 to limit the maximum pressure in the working chamber of the boom cylinder. When the pressure in a certain working chamber of the boom cylinder (for example, when the boom cylinder is subjected to a huge external impact load) rises abnormally and exceeds the upper limit of the safety pressure set by the system, the secondary relief valve 18 opens to discharge the overpressure oil back to the oil tank, thereby preventing damage to the cylinder, pipeline, seals or other hydraulic components due to excessive pressure.

[0055] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "set", "equipped with", "connected", and "installed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy recovery electro-hydraulic proportional multi-way valve with floating control, comprising a valve body, a boom valve stem (1) disposed within the valve body and at least one functional valve stem (2), a hydraulic pump (3) for supplying hydraulic oil, and a main relief valve (4) disposed on the oil inlet path between the hydraulic pump (3) and the boom valve stem (1); characterized in that, It also includes a proportional solenoid valve (5), which is disposed between the oil return passage of the boom valve stem (1) and the oil inlet passage of the functional valve stem (2). The boom valve stem (1) is configured as a four-position valve stem with four working positions, including a floating position, a descent regeneration position, a neutral position, and a lifting position. When the boom valve stem (1) is in the descent regeneration position, the return oil discharged from the rod chamber (B1) of the boom cylinder forms two branches: the first branch flows to the rodless chamber (A1) of the boom cylinder through the regeneration flow channel provided inside the boom valve stem (1); the second branch flows to the oil inlet of the functional valve stem (2) through the proportional solenoid valve (5).

2. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, When the boom valve stem (1) is in the floating position, the oil inlet of the hydraulic pump (3) is directly connected to the next function valve stem (2), and at the same time, the boom valve stem (1) controls the rodless chamber (A1) and the rod chamber (B1) of the boom cylinder to be connected to the return oil tank, so that the boom is in a floating state.

3. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, The regeneration channel includes an axial hole (6) opened inside the boom valve stem (1) and a built-in check valve (7) disposed in the axial hole. When in the descending regeneration position, the high-pressure return oil from the rod chamber (B1) enters the axial hole (6) through the valve stem radial hole, and flows into the oil port communicating with the rodless chamber (A1) after passing through the built-in check valve (7).

4. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 3, characterized in that, The valve body is also provided with an external regeneration check valve (8), which works in conjunction with the built-in check valve (7) to restrict the flow of oil from the rod chamber (B1) to the rodless chamber (A1) for one-way oil replenishment.

5. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, The valve body is provided with a first working oil port (9), a second working oil port (10) and a third working oil port (11) at the position corresponding to the boom valve stem (1); The first working oil port (9) is connected to the rodless chamber (A1) of the boom cylinder, the third working oil port (11) is connected to the rod chamber (B1) of the boom cylinder, the second working oil port (10) is used to connect to the oil inlet of the next function valve stem (2), and the fourth oil inlet (12) is used to connect to the return oil tank.

6. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 5, characterized in that, The valve body is also provided with a first oil inlet (13), a second oil inlet (14), a third oil inlet (15), and a fourth oil inlet (12) at the position corresponding to the boom valve stem (1); When the boom valve stem (1) is in the floating position, the second oil inlet (14) is connected to the second working oil inlet (10), and the first working oil inlet (9) and the third working oil inlet (11) are simultaneously connected to the fourth oil inlet (12). When the boom valve stem (1) is in the lowering regeneration position, the first oil inlet (13) is connected to the first working oil inlet (9), and the third oil inlet (15) is connected to the third working oil inlet (11). When the boom valve stem (1) is in the neutral position, the second oil inlet (14) is connected to the second working oil inlet (10), and the first oil inlet (13), the third oil inlet (15), the fourth oil inlet (12), the first working oil inlet (9) and the third working oil inlet (11) are not connected to each other; When the boom valve stem (1) is in the lifting position, the first oil inlet (13) is connected to the third working oil inlet (11), the third oil inlet (15) is connected to the first working oil inlet (9), and the second oil inlet (14), the fourth oil inlet (12), and the second working oil inlet (10) are in the closed state.

7. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 6, characterized in that, The inlet of the proportional solenoid valve (5) is connected to the third inlet (15), and the outlet is connected to the inlet channel of the functional valve stem (2). It is used to adjust the valve opening according to the working state or load pressure signal of the functional valve stem (2) and control the flow ratio allocated to the functional valve stem (2).

8. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, The valve body is also equipped with an oil inlet check valve (16). The oil inlet check valve (16) is located between the hydraulic pump (3) and the oil inlet channel of the boom valve stem (1) to prevent oil from flowing back from the boom valve stem (1) to the hydraulic pump (3).

9. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, The valve body is also equipped with a one-way oil replenishment valve (17). One end of the oil replenishment check valve (17) is connected to the return oil tank, and the other end is connected to the flow channel of the rodless chamber (A1) of the boom cylinder. It is used to replenish hydraulic oil from the return oil tank to the rodless chamber (A1) when negative pressure is generated in the rodless chamber (A1) of the boom cylinder.

10. The energy recovery electro-hydraulic proportional multi-way valve with floating control according to claim 1, characterized in that, A secondary overflow valve (18) is also connected in parallel on the flow channel corresponding to the boom valve stem (1) to limit the maximum pressure of the boom cylinder working chamber.

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