Closed hydraulic system and pump valve integrated device

Abstract

The utility model relates to the technical field of hydraulic control, in particular to a closed hydraulic system and a pump-valve integrated device. Comprising a two-way pump, a first main oil way, a second main oil way, an energy accumulator and a symmetrical execution unit. A pressure suction oil cavity A and a pressure suction oil cavity B of the two-way pump communicate with the first main oil way and the second main oil way correspondingly. An oil pumping cavity of the two-way pump is communicated with the energy accumulator; the energy accumulator communicates with the first main oil way and the second main oil way through the first one-way valve and the second one-way valve correspondingly. The first main oil way and the second main oil way are communicated with an oil pumping cavity of the two-way pump through a first overflow valve and a second overflow valve respectively. A first switch electromagnetic valve is connected between the suction and pressure oil cavity A and the first oil port of the symmetrical execution unit, and a second switch electromagnetic valve is connected between the suction and pressure oil cavity B and the second oil port of the symmetrical execution unit. According to the utility model, the pump and the valve block are integrated, the design of a hydraulic oil duct is compact, a symmetrical closed hydraulic system is adopted, a hydraulic loop is simplified, the size of the hydraulic system is reduced, and the hydraulic system can be applied to various small machines.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic control, in particular to a closed hydraulic system and a pump-valve integrated device. Background Art

[0002] As a relatively mature automated tool, mobile robots have been widely used in high-risk and high-intensity working environments such as industry, disaster relief, etc. Such robots significantly reduce the labor intensity of humans and can effectively replace humans in dangerous environments. Among them, multi-legged robots can, like multi-legged animals, rely on their unique walking method, that is, they can walk freely on complex terrains with only discrete foot landing points and have high adaptability to complex road surfaces. This characteristic enables multi-legged walking robots to develop rapidly and be widely used in multiple fields.

[0003] The typical structure of a multi-legged robot includes a torso and multiple hydraulic mechanical legs. Taking the hydraulic pump cylinder control drive system of a quadruped robot with the patent number CN202222609650.9 as an example, the system includes components such as a side swing unit, a hip unit, a knee unit, a servo motor, a hydraulic pump, and a hydraulic cylinder accumulator. However, the hydraulic cylinder in this system adopts an asymmetric design with a rod chamber oil port and a rodless chamber oil port, resulting in different volumes in the hydraulic cylinder under working conditions and different flow rates during oil inlet and oil return; this requires a supplementary oil circuit composed of a double hydraulic control check valve and a large accumulator to deal with, which not only increases the difficulty of the hydraulic system circuit design but also increases the volume of the hydraulic system, making the overall product volume too large and having problems that are not convenient for load-bearing applications. Summary of the Utility Model

[0004] To solve the problems in the prior art that the closed hydraulic system of the robot has a large volume, resulting in a large product volume and being inconvenient for load-bearing and application, the utility model provides a closed hydraulic system and a pump-valve integrated device, which have the advantages of compact structure and small volume.

[0005] To achieve the above purpose, this patent provides a closed hydraulic system, which includes a bidirectional pump, main oil circuit one, main oil circuit two, an accumulator, and a symmetric execution unit. The symmetric execution unit is provided with an oil port one and an oil port two. The suction and pressure oil chambers A and B of the bidirectional pump are respectively connected to the main oil circuit one and the main oil circuit two; the pump oil chamber of the bidirectional pump is connected to the accumulator; the accumulator is respectively connected to the main oil circuit one and the main oil circuit two through a one-way valve one and a one-way valve two; the main oil circuit one and the main oil circuit two are respectively connected to the pump oil chamber of the bidirectional pump through a relief valve one and a relief valve two; a switch solenoid valve one is connected between the suction and pressure oil chamber A and the oil port one of the symmetric execution unit, and a switch solenoid valve two is connected between the suction and pressure oil chamber B and the oil port two of the symmetric execution unit.

[0006] Further, a first pressure sensor and a second pressure sensor are respectively connected to the front - section oil path and the rear - section oil path of the first switching solenoid valve; a third pressure sensor and a fourth pressure sensor are respectively connected to the front - section oil path and the rear - section oil path of the second switching solenoid valve.

[0007] Further, a manual switching valve is further included, and the manual switching valve is communicated with the first oil port and the second oil port of the symmetric actuator unit.

[0008] Further, a first exhaust port is provided between the manual switching valve and the first oil port of the symmetric actuator unit; a second exhaust port is provided between the manual switching valve and the second oil port of the symmetric actuator unit.

[0009] Further, an oil injection port communicated with the accumulator is further included, and a third one - way valve is connected between the oil injection port and the accumulator.

[0010] Further, a temperature sensor communicated with the accumulator is further included.

[0011] The present utility model further provides a pump - valve integrated device, which includes the above - mentioned closed - type hydraulic system, and further includes a valve body. A two - way pump and an accumulator are installed in the valve body. The two - way pump is drivingly connected with a motor; the two - way pump forms a pump oil cavity, a suction - pressure oil cavity A and a suction - pressure oil cavity B in the valve cavity; the pump oil cavity is communicated with the accumulator; an oil hole one and an oil hole two communicated with the first oil port and the second oil port of the symmetric actuator unit are provided on the valve body;

[0012] The pump oil cavity is communicated with the suction - pressure oil cavity A through a first overflow valve and a first one - way valve respectively; the suction - pressure oil cavity A is communicated with the oil hole one through a first switching solenoid valve; the pump oil cavity is communicated with the suction - pressure oil cavity B through a second overflow valve and a second one - way valve respectively; the suction - pressure oil cavity B is communicated with the oil hole two through a second switching solenoid valve.

[0013] Further, an oil filling hole serving as an oil injection port is provided on the outer side of the valve body, and the oil filling hole is communicated with the accumulator through a third one - way valve.

[0014] Further, heat dissipation fins are provided on the outer side of the valve body.

[0015] The beneficial effects of the present utility model are as follows:

[0016] 1. The pump and the valve block are integrated into one body, the hydraulic oil path is designed compactly, and the volume of the hydraulic system is reduced;

[0017] 2. A symmetric closed - type hydraulic system is adopted, and there is no need for a make - up oil circuit composed of double hydraulic control one - way valves and a large accumulator, which simplifies the hydraulic circuit, helps to reduce the volume of the hydraulic system, and can be adapted to various small machines. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 is the hydraulic schematic diagram of the closed - type hydraulic system of the present utility model;

[0019] Appendix Figure 2 is the overall structural schematic diagram of the pump-valve integrated device of the present utility model;

[0020] Appendix Figure 3 is Figure 2 the structural schematic diagram from another angle;

[0021] Appendix Figure 4 is the sectional view of the pump-valve integrated device of the present utility model;

[0022] Appendix Figure 5 is the valve body structure diagram of the pump-valve integrated device of the present utility model;

[0023] Appendix Figure 6 is Figure 5 the structural schematic diagram from another angle;

[0024] In the figure: 1. Bidirectional pump; 2. Main oil circuit one; 3. Main oil circuit two; 4. Symmetrical execution unit; 5. Oil port one; 6. Oil port two; 7. Suction and pressure oil chamber A; 8. Suction and pressure oil chamber B; 9. Pump oil chamber; 10. Accumulator; 11. Check valve one; 12. Check valve two; 13. Relief valve one; 14. Relief valve two; 15. Switch solenoid valve one; 16. Switch solenoid valve two; 17. Pressure sensor one; 18. Pressure sensor two; 19. Pressure sensor three; 20. Pressure sensor four; 21. Manual switch valve; 22. Exhaust port one; 23. Exhaust port two; 24. Oil filling port; 25. Temperature sensor; 26. Valve body; 27. Motor; 28. Oil hole one; 29. Oil hole two; 30. Oil charging hole; 31. Check valve three; 32. Heat sink; 33. Fixing hole; 34. Sealing ring; 35. Relief valve seat one; 36. Switch valve seat one; 37. Relief valve seat two; 38. Switch valve seat two. Specific embodiments

[0025] The following further describes the closed hydraulic system and the pump-valve integrated device of the present utility model in conjunction with embodiments.

[0026] As Figure 1As shown in the figure, a closed hydraulic system includes a two-way pump 1, a first main oil circuit 2, a second main oil circuit 3, an accumulator 10, and a symmetric actuator unit 4. The symmetric actuator unit 4 is provided with an oil port 5 and an oil port 6. The suction and pressure oil chambers A7 and B8 of the two-way pump 1 are respectively connected to the first main oil circuit 2 and the second main oil circuit 3. The pump oil chamber 9 of the two-way pump 1 is connected to the accumulator 10. The accumulator 10 is respectively connected to the first main oil circuit 2 and the second main oil circuit 3 through a check valve 11 and a check valve 12. The first main oil circuit 2 and the second main oil circuit 3 are respectively connected to the pump oil chamber 9 of the two-way pump 1 through a relief valve 13 and a relief valve 14. A switching solenoid valve 15 is connected between the suction and pressure oil chamber A7 and the oil port 5 of the symmetric actuator unit 4, and a switching solenoid valve 16 is connected between the suction and pressure oil chamber B8 and the oil port 6 of the symmetric actuator unit 4.

[0027] In the present utility model, the pump and the valve block are integrated into one body, the hydraulic oil passage is designed compactly, and a symmetric closed hydraulic system is adopted, without a make-up oil circuit composed of double hydraulic control check valves and a large accumulator 10, which simplifies the hydraulic circuit and helps to reduce the volume of the hydraulic system.

[0028] The oil in the pump oil chamber 9 of the two-way pump 1 directly enters the accumulator 10. When the pressure on one side of the first main oil circuit 2 and the second main oil circuit 3 is lower than the oil pressure in the accumulator 10, the oil in the accumulator 10 will enter the corresponding first main oil circuit 2 and the second main oil circuit 3 through the check valve 11 and the check valve 12 to compensate for the pressure.

[0029] The symmetric actuator unit 4 is a double-piston hydraulic cylinder. The switching solenoid valve 15 and the switching solenoid valve 16 are used to control the corresponding oil circuit to flow. When the corresponding switching solenoid valve is closed, the double-piston hydraulic cylinder will be locked in a specific position, locking the robot in a certain posture. The relief valve 13 and the relief valve 14 are used to limit the system pressure not to exceed a certain value. When the pressure of one side of the oil circuit is too high, the relief valve corresponding to this oil circuit will open, and the oil will flow from the high-pressure side to the low-pressure side.

[0030] In this embodiment, the accumulator 10 is of a spring piston type or an oil-resistant elastomer structure. The two-way pump 1 is an axial piston pump, specifically an inclined plate type axial piston pump. When the plunger rotates to the topmost position, the plunger hole is just filled with oil and is about to discharge oil outward, which is the critical state of about to discharge oil outward. For each revolution of the cylinder block of the inclined plate type axial piston pump, each plunger reciprocates once, completing one oil suction and discharge action. By changing the inclination angle of the inclined plate, the effective change amount of the sealed working volume can be changed to achieve variable displacement of the pump.

[0031] As Figure 1 shown, a pressure sensor 17 and a pressure sensor 18 are respectively connected to the front-section oil circuit and the rear-section oil circuit of the switching solenoid valve 15; a pressure sensor 19 and a pressure sensor 20 are respectively connected to the front-section oil circuit and the rear-section oil circuit of the switching solenoid valve 16.

[0032] Pressure sensors two 18 and four 20 are used to measure the hydraulic pressure in the two oil cylinders of the symmetric actuator unit 4. Pressure sensors one 17 and three 19 are respectively used to measure the pre-valve pressure of solenoid valve one 15 and solenoid valve two 16, and cooperate with pressure sensors two 18 and four 20 to determine the opening timing of the corresponding solenoid valves through the control program, so as to avoid hydraulic pressure shock.

[0033] As Figure 1 shown, it further includes a manual switch valve 21, and the manual switch valve 21 is communicated with the first oil port 5 and the second oil port 6 of the symmetric actuator unit 4. When needed, for example, when the robot leg needs to be bent and retracted, the manual switch valve 21 can be used to communicate the two oil cylinders of the double-piston hydraulic cylinder to adjust the position of the piston, so as to release the locked posture of the robot.

[0034] Preferably, it further includes an oil filling port 24 communicated with the accumulator 10, and a check valve three 31 is communicated between the oil filling port 24 and the accumulator 10. During the operation of the hydraulic system, the hydraulic oil may leak, evaporate, age, etc., and the amount of hydraulic oil will decrease, resulting in a decline in system performance or abnormal operation. The oil filling port 24 can timely supplement the hydraulic oil, so as to maintain the normal operation of the hydraulic system.

[0035] Preferably, an exhaust port one 22 is provided between the manual switch valve 21 and the first oil port 5 of the symmetric actuator unit 4; an exhaust port two 23 is provided between the manual switch valve 21 and the second oil port 6 of the symmetric actuator unit 4. It is used to exhaust the air in the hydraulic system completely, so as to fill the hydraulic system with oil through the oil filling port 24.

[0036] Preferably, it further includes a temperature sensor 25 communicated with the accumulator 10. As the working medium in the hydraulic system, the temperature of the hydraulic oil has a direct impact on the system performance and stability. The temperature sensor 25 can sense and measure the temperature of the hydraulic oil in real time and convert it into a signal for system monitoring and control.

[0037] As Figure 2 , Figure 3 , Figure 4 , Figure 5 shown, a pump-valve integrated device includes the above-mentioned closed hydraulic system, and further includes a valve body 26. A two-way pump 1 and an accumulator 10 are installed in the valve body 26. The two-way pump 1 is drivingly connected to a motor 27; the two-way pump 1 forms a pump oil chamber 9, a suction and pressure oil chamber A7 and a suction and pressure oil chamber B8 in the valve cavity; the pump oil chamber 9 is communicated with the accumulator 10; an oil hole one 28 and an oil hole two 29 communicated with the first oil port 5 and the second oil port 6 of the symmetric actuator unit 4 are provided on the valve body 26;

[0038] The pump oil chamber 9 is communicated with the suction and pressure oil chamber A7 through an overflow valve 13 and a check valve 11 respectively; the suction and pressure oil chamber A7 is communicated with the oil hole 28 through a switch solenoid valve 15. The pump oil chamber 9 is communicated with the suction and pressure oil chamber B8 through an overflow valve 14 and a check valve 12 respectively; the suction and pressure oil chamber B8 is communicated with the oil hole 29 through a switch solenoid valve 16. In this embodiment, the motor 27 is connected to the power shaft of the double pump 1 through a coupling. The motor 27 is a frameless motor and is encapsulated with a separately designed heat dissipation cover to make its volume as small as possible. The structural part of the valve body 26 is integrally formed by a metal 3D printing process, which reduces the connection path between various valves and the valve body, makes the flow channel more compact, and helps to reduce the volume of the hydraulic system. By installing the pump core part of the piston pump inside the valve body 26, the double pump and the closed hydraulic system are integrated into a valve body 26. Sealing rings 34 are installed at the connection positions of the oil chamber, the suction and pressure oil chamber A7, and the suction and pressure oil chamber B8. The oil hole 28 and the oil hole 29 are communicated with the two oil cylinders of the symmetric actuator unit 4 through a hydraulic flow channel.

[0039] Preferably, an oil filling hole 30 serving as an oil injection port 24 is provided on the outer side of the valve body 26, and the oil filling hole 30 is communicated with the accumulator 10 through a check valve 31.

[0040] Preferably, heat dissipation fins 32 are provided on the outer side of the valve body 26. The heat dissipation fins 32 provide more heat dissipation area, which helps to reduce the temperature of the valve body 26 and the hydraulic system, conduct the heat to the surrounding environment, and ensure the stable operation of the system. As Figure 5 、 Figure 6 , the overflow valve 13 and the overflow valve 14 adopt a plug-in structure and are respectively inserted on the overflow valve seat 35 and the overflow valve seat 37; the switch solenoid valve 15 and the switch solenoid valve 16 adopt a plug-in structure and are respectively inserted on the switch valve seat 36 and the switch valve seat 38, making the flow channel compact and helping to reduce the volume of the hydraulic system.

Claims

1. A closed hydraulic system, comprising a bidirectional pump (1), a main oil circuit 1 (2), a main oil circuit 2 (3), an accumulator (10) and a symmetrical execution unit (4), wherein the symmetrical execution unit (4) is provided with an oil port 1 (5) and an oil port 2 (6), characterized in that: The suction and pressure oil chamber A (7) and the suction and pressure oil chamber B (8) of the bidirectional pump (1) are respectively connected to the main oil circuit 1 (2) and the main oil circuit 2 (3); the pump oil chamber (9) of the bidirectional pump (1) is connected to the accumulator (10); the accumulator (10) is respectively connected to the main oil circuit 1 (2) and the main oil circuit 2 (3) through a one-way valve 1 (11) and a one-way valve 2 (12); the main oil circuit 1 (2) is connected to the pump oil chamber (9) of the bidirectional pump (1) through a relief valve 1 (13); the main oil circuit 2 (3) is connected to the pump oil chamber (9) of the bidirectional pump (1) through a relief valve 2 (14); a switch solenoid valve 1 (15) is connected between the suction and pressure oil chamber A (7) and the oil port 1 (5) of the symmetrical actuator unit (4), and a switch solenoid valve 2 (16) is connected between the suction and pressure oil chamber B (8) and the oil port 2 (6) of the symmetrical actuator unit (4).

2. The closed hydraulic system according to claim 1, characterized in that: A pressure sensor 1 (17) and a pressure sensor 2 (18) are respectively connected to the front section oil circuit and the rear section oil circuit of the switch solenoid valve 1 (15); a pressure sensor 3 (19) and a pressure sensor 4 (20) are respectively connected to the front section oil circuit and the rear section oil circuit of the switch solenoid valve 2 (16).

3. The closed hydraulic system according to claim 1 or 2, characterized in that: It also includes a manual switch valve (21), which is connected to the oil port 1 (5) and the oil port 2 (6) of the symmetrical execution unit (4).

4. The closed hydraulic system according to claim 3, characterized in that: An exhaust port 1 (22) is provided between the manual switch valve (21) and the oil port 1 (5) of the symmetrical execution unit (4); and an exhaust port 2 (23) is provided between the manual switch valve (21) and the oil port 2 (6) of the symmetrical execution unit (4).

5. The closed hydraulic system according to claim 1, 2 or 4, characterized in that: It also includes an oil injection port (24) connected to the accumulator (10), and a check valve (31) is connected between the oil injection port (24) and the accumulator (10).

6. The closed hydraulic system according to claim 3, characterized in that: It also includes an oil injection port (24) connected to the accumulator (10), and a check valve (31) is connected between the oil injection port (24) and the accumulator (10).

7. A closed hydraulic system according to claim 1, 2, 4 or 6, characterized in that: Also included is a temperature sensor (25) in communication with the accumulator (10).

8. A pump-valve integrated device, characterized in that: A closed hydraulic system comprising any one of claims 1 to 7, further comprising a valve body (26), a bidirectional pump (1) and an accumulator (10) being installed in the valve body (26), the bidirectional pump (1) being transmission-connected to a motor (27); the bidirectional pump (1) forming a pump oil chamber (9), a suction and pressure oil chamber A (7) and a suction and pressure oil chamber B (8) in the valve chamber; the pump oil chamber (9) being in communication with the accumulator (10); The valve body (26) is provided with an oil hole 1 (28) and an oil hole 2 (29) which are in communication with the oil port 1 (5) and the oil port 2 (6) of the symmetrical execution unit (4); The pump oil chamber (9) and the suction oil chamber A (7) are connected through a relief valve 1 (13) and a check valve 1 (11) respectively; the suction oil chamber A (7) and the oil hole 1 (28) are connected through a switch solenoid valve 1 (15); the pump oil chamber (9) and the suction oil chamber B (8) are connected through a relief valve 2 (14) and a check valve 2 (12) respectively; the suction oil chamber B (8) and the oil hole 2 (29) are connected through a switch solenoid valve 2 (16).

9. The integrated pump-valve device according to claim 8, characterized in that: An oil filling hole (30) serving as an oil filling port (24) is provided on the outside of the valve body (26), and the oil filling hole (30) is communicated with the accumulator (10) via a check valve (31).

10. The integrated pump-valve device according to claim 8 or 9, characterized in that: A heat sink (32) is provided on the outside of the valve body (26).

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