Hydraulic circuit
By introducing leakage flow and pressure balance lines into the hydraulic system, the problem of existing hydraulic systems requiring additional lines to export fluid is solved, efficient boosting and decompression is achieved, and system complexity and cost are reduced.
Patent Information
- Application Number
- CN202410528218.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-08-18
- Filing Date
- 2024-04-29
- Publication Date
- 2025-02-21
AI Technical Summary
When the existing hydraulic systems are supercharged and depressurized at high pressure joints, additional lines are required to derive excess fluid, which increases the complexity and cost of the system.
A hydraulic circuit is designed to achieve boosting and decompression at high pressure joints by introducing leakage flow and pressure balance lines into the pump and check valve systems, and no additional lines are required to derivate fluid.
Efficient pressure boosting and decompression at high-pressure joints are achieved, reducing the complexity and cost of hydraulic circuits while maintaining the controllability and efficiency of the system.
Smart Images
Figure CN119491848A_ABST
Abstract
Description
[0001] The invention relates to a hydraulic circuit. Background Art
[0002] The hydraulic system for pressurization and decompression has a high-pressure connection, a low-pressure connection, a supply unit, a pump and an unlockable non-return valve. In a first state, the fluid is sucked in by the pump via the supply unit and the low-pressure connection and delivered to the high-pressure connection through the non-return valve. As a result, pressurization is achieved at the high-pressure connection. In a second state, the fluid is delivered to the control connection of the non-return valve via the supply unit and the low-pressure connection. This allows the fluid to flow from the high-pressure connection through the non-return valve in the shut-off direction of the non-return valve. As a result, decompression is achieved at the high-pressure connection.
[0003] In the second state, the fluid is delivered to the control connection of the check valve until a predetermined pressure is established at the control connection. However, hardly any fluid flows through the control valve. The pump can only reliably maintain pressure if the pump delivers fluid. Therefore, in order to maintain the pressure at the control valve, the fluid must be continuously delivered by the pump. In order to drain the excess fluid, an additional line is currently required. This additional line is arranged between the pump and the control connection of the check valve.
[0004] The object of the present invention is to provide a hydraulic circuit which allows targeted pressure increase and pressure reduction at the high-pressure connection and which minimizes the number of fluid lines of the hydraulic circuit.
[0005] This object is achieved by a hydraulic circuit according to independent claim 1 .
[0006] The hydraulic circuit comprises a high-pressure connector, a low-pressure connector, a supply unit and a pump system. The low-pressure connector is fluidically connected to the high-pressure connector by means of a series connection of the supply unit and the pump system. The pump system has a pump for conveying fluid, a shaft for driving the pump and at least one unlockable check valve system. The pump is configured to convey fluid from a first pump connector to a second pump connector in a first state, and to convey fluid from the second pump connector to the first pump connector in a second state. The check valve system is fluidically connected to the second pump connector at a first valve connector and fluidically connected to the high-pressure connector at a second valve connector. The check valve system is designed to prevent fluid from flowing from the second valve connector to the first valve connector and to allow fluid to flow from the first valve connector to the second valve connector. The check valve system has a control connector, through which the fluid flow from the second valve connector to the first valve connector can be released. The hydraulic circuit is designed to release the fluid flow from the second valve connector to the first valve connector through the control connector when the pump is in the second state. The supply unit is configured to enable a fluid flow from the low-pressure connection to the first pump connection and prevent a fluid flow from the second pump connection to the low-pressure connection in a first state of the pump. The supply unit is configured to enable a fluid flow from the low-pressure connection to the second pump connection and prevent a fluid flow from the first pump connection to the low-pressure connection in a second state of the pump. When conveying the fluid, the pump has a leakage flow toward the shaft. The shaft is connected to the low-pressure connection by means of a pressure equalization line in order to conduct the fluid from the shaft. Alternatively or additionally, when the pump is in the second state, the non-return valve system has a leakage flow between the control connection and the first valve connection.
[0007] In the first state, the fluid is sucked from the low-pressure connector via the first pump connector and delivered to the first valve connector via the second pump connector. The supply unit prevents the fluid from flowing back from the second pump connector to the low-pressure connector. Subsequently, the fluid is delivered to the second valve connector and the high-pressure connector via the check valve system. Therefore, in the first state, the fluid is delivered from the low-pressure connector to the high-pressure connector through the pump and the check valve system, and the pressure of the fluid at the high-pressure connector is increased. Therefore, the fluid can be actively and controllably supplied to the high-pressure connector by means of the manipulation of the pump. If the delivery of the pump stops, no fluid will reach the high-pressure connector from the low-pressure connector through the pump and the check valve system. The check valve system prevents the fluid from flowing back from the high-pressure connector through the pump to the low-pressure connector.
[0008] In the second state, the fluid is sucked in from the low-pressure connection via the second pump connection and delivered to the control connection of the non-return valve system via the first pump connection. The supply unit prevents the fluid from flowing back from the first pump connection to the low-pressure connection. By increasing the pressure at the control connection, the non-return valve system allows the fluid to flow from the high-pressure connection through the second valve connection, the non-return valve system and the first valve connection. Thus, the fluid can be actively and controllably discharged from the high-pressure connection by means of the pump control, and the pressure of the fluid at the high-pressure connection is reduced.
[0009] When the pump is running, there is a leakage flow of a portion of the delivered fluid in the pump and / or the check valve system. The leakage flow in the pump will reach the shaft of the pump and be led to the low-pressure connector via the pressure balance line. The leakage flow in the check valve system reaches the low-pressure connector via the first valve connector. Through the leakage flow, the pump can operate normally and the pressure at the control connector is maintained without damaging the pump. In addition, during the process of pressurization and pressure maintenance at the control connector, no additional lines are required to lead out the fluid. The delivered fluid for pressurization at the control connector is led to the low-pressure connector via the leakage flow and / or the pressure balance line. Because leakage flow occurs in each operating state of the pump, a pressure balance line is always required. Therefore, no line is required between the first pump connector and the control connector. This reduces the complexity of the hydraulic circuit.
[0010] The dependent claims reveal preferred developments of the invention.
[0011] Preferably, the check valve system has at least one first check valve. The first check valve is connected to the first valve connection at the first check valve connection and to the second valve connection at the second check valve connection. The first check valve is designed to prevent the fluid from flowing from the second check valve connection to the first check valve connection and to allow the fluid to flow from the first check valve connection to the second check valve connection. This allows efficient pressure increase at the high-pressure connection in the first state, because no additional hydraulic elements are arranged between the first valve connection and the second valve connection, which would form a hydraulic resistance.
[0012] Particularly preferably, the first check valve is designed to be unlockable. The first check valve has a first check valve control connection, through which the fluid flow from the second check valve connection to the first check valve connection can be released. The first check valve control connection is fluidically connected to the control connection. Therefore, the function of the check valve system can be realized by means of a single check valve, and the system complexity of the hydraulic circuit can be kept very low.
[0013] Particularly preferably, the check valve has a working chamber, a piston and a check element. The check element is configured to prevent the fluid from flowing from the second check valve connector to the first check valve connector in the third state of the check element. The check element is configured to release the fluid flow from the second check valve connector to the first check valve connector in the fourth state of the check element. The piston is configured to move in a first direction and place the check element in a fourth state when a fluid flows into the working chamber via a control connector and the fluid increases the pressure in the working chamber. The check valve has a leakage flow flowing through the working chamber between the check valve control connector and the first check valve connector. Through the above-mentioned design of the working chamber and the piston, an additional line can be omitted to transport the leakage flow. This simplifies the manufacture of the hydraulic circuit.
[0014] Advantageously, the non-return valve system has at least one first throttle valve. The first throttle valve is directly connected to the second valve connection. The first non-return valve and the first throttle valve are connected in series with each other in a fluid manner. This allows a slower fluid flow from the high-pressure connection through the first throttle valve and the first non-return valve system. By means of this slower fluid flow, the fluid flow and thus the pressure reduction at the high-pressure connection can be controlled more simply.
[0015] Particularly advantageously, the non-return valve system has at least one second non-return valve and a third valve connection. The third valve connection is fluidically connected to the second pump connection. The second non-return valve is fluidically connected to the third valve connection at the third non-return valve connection and is fluidically connected to the second valve connection at the fourth non-return valve connection. The second non-return valve is designed to prevent fluid from flowing from the fourth non-return valve connection to the third non-return valve connection and to allow fluid to flow from the third non-return valve connection to the fourth non-return valve connection.
[0016] Therefore, in the check valve system, the first hydraulic path between the first valve connector and the second valve connector and the second hydraulic path between the third valve connector and the second valve connector can be formed independently of each other. The second hydraulic path only allows the fluid flow to the second valve connector and the high-pressure connector through the second check valve and thus allows the pressure increase at the high-pressure connector. In addition, by means of the first hydraulic path, the fluid can be delivered to the high-pressure connector through the first check valve and thus the pressure at the high-pressure connector is increased. By the parallel arrangement of the first check valve and the second check valve in the fluid sense, the fluid resistance between the second pump connector and the high-pressure connector is reduced and the efficiency of the hydraulic circuit is improved.
[0017] The fluid cannot be led out of the high-pressure connection via the second hydraulic path and the pressure is thus reduced. In the second state, the first hydraulic path allows a fluid flow from the high-pressure connection via the unlockable first non-return valve to the first valve connection and thus allows a pressure reduction at the high-pressure connection. This allows a controlled pressure reduction at the high-pressure connection.
[0018] By arranging the first throttle valve between the second valve connection and the second non-return valve connection, the fluid flow via the first hydraulic path and thus the pressure reduction at the high-pressure connection can be slowed down in the second state. This improves the controllability of the pressure reduction at the high-pressure connection during the second state. In addition, the efficiency in terms of pressure increase is increased, because the fluid can also flow from the first pump connection to the high-pressure connection via the second hydraulic path without having to pass through the throttle valve here.
[0019] Particularly preferably, the non-return valve system has a third non-return valve. The third non-return valve is fluidically connected to the second valve connection at the fifth non-return valve connection and is fluidically connected to the second non-return valve connection at the sixth non-return valve connection. The third non-return valve is designed to prevent fluid from flowing from the fifth non-return valve connection to the sixth non-return valve connection and to allow fluid to flow from the sixth non-return valve connection to the fifth non-return valve connection. The third non-return valve is arranged in parallel with the first throttle valve in a fluidic sense.
[0020] In the first state, the fluid flows through the first valve joint, the first check valve and the second valve joint and increases the pressure at the high-pressure joint. The fluid flows partially through the third check valve and partially through the first throttle valve between the first check valve and the second valve joint. This arrangement forms a smaller fluid resistance to the fluid flow, as if the entire fluid flows only through the first throttle valve. This arrangement improves the efficiency of the check valve system. In the second state, the third check valve prevents the fluid from flowing from the fifth check valve joint to the sixth check valve joint. The entire fluid flows from the high-pressure joint via the second valve joint through the first throttle valve, the first check valve and the first valve joint. Because the entire fluid flows through the first throttle valve between the second valve joint and the first valve joint, the entire fluid flow slows down. This simplifies the control of the decompression at the high-pressure joint. Therefore, this embodiment allows efficient pressurization at the high-pressure joint and better controllability of decompression.
[0021] Advantageously, the check valve system has a second throttle valve, a fourth check valve and a fifth check valve. The second throttle valve, the fourth check valve and the fifth check valve are arranged between the first check valve and the first valve joint in a fluid sense. The fourth check valve is fluidly connected to the first check valve joint at the seventh check valve joint, and is fluidly connected to the first valve joint at the eighth check valve joint. The fourth check valve is designed to prevent the fluid from flowing from the seventh check valve joint to the eighth check valve joint, and to allow the fluid to flow from the eighth check valve joint to the seventh check valve joint. The fifth check valve is arranged in anti-parallel with the fourth check valve. The fifth check valve is fluidly connected to the first check valve joint at the ninth check valve joint, and is fluidly connected to the first valve joint at the tenth check valve joint. The fifth check valve is designed to prevent the fluid from flowing from the tenth check valve joint to the ninth check valve joint, and to allow the fluid to flow from the ninth check valve joint to the tenth check valve joint. The second throttle valve is arranged fluidically between the tenth non-return valve connection and the second valve connection and in parallel with the fourth non-return valve.
[0022] In the first state, the fluid flows from the first pump connection through the fourth check valve and the first check valve to the high-pressure connection, and the pressure at the high-pressure connection is increased. In the first state, the orientation of the fifth check valve prevents the flow of fluid via the fifth check valve and thus via the second throttle valve. This allows high efficiency in the first state because no losses due to the second throttle valve occur. In the second state, the fluid flows from the high-pressure connection through the fifth check valve and the second throttle valve to the first valve connection. In the second state, the fourth throttle valve blocks the fluid flow, and all the fluid flows through the fifth check valve and the second throttle valve. The second throttle valve slows down the fluid flow, so that the fluid flow can be controlled more simply in the second state. Therefore, this embodiment allows an efficient pressure increase at the high-pressure connection in the first state and an easily controllable pressure reduction at the high-pressure connection in the second state.
[0023] Particularly advantageously, the check valve system comprises a fourth valve connection, an unlockable sixth check valve and a third throttle valve. The fourth valve connection is fluidically connected to the low-pressure connection. The sixth check valve is fluidically connected to the fourth valve connection at the eleventh check valve connection and is fluidically connected to the second valve connection at the twelfth check valve connection. The sixth check valve is designed to prevent fluid from flowing from the twelfth check valve connection to the eleventh check valve connection and to allow fluid to flow from the eleventh check valve connection to the twelfth check valve connection. The sixth check valve has a second check valve control connection, through which the fluid flow from the twelfth check valve connection to the eleventh check valve connection can be released. The second check valve control connection is fluidically connected to the control connection.
[0024] In the first state, the fluid flows to the high-pressure connection via at least the first valve connection and the second valve connection and increases the pressure at the high-pressure connection. In this case, no fluid flows through the third throttle valve. In the second state, the fluid flows from the first pump connection via the control connection to the second check valve control connection. As a result, the sixth check valve allows the fluid to flow from the high-pressure connection via the second valve connection and the fourth valve connection to the low-pressure connection, and decompression can be achieved. In this case, the fluid also flows through the third throttle valve and is decelerated. This improves the controllability of the decompression at the high-pressure connection without negatively affecting the efficiency of the pressurization at the high-pressure connection.
[0025] Preferably, the hydraulic circuit has a pressure-limiting valve. The pressure-limiting valve is connected to the high-pressure connection at a first pressure-limiting valve connection and to the low-pressure connection at a second pressure-limiting valve connection. The pressure-limiting valve is connected to the high-pressure connection and the low-pressure connection in parallel with the pump system and the supply unit. In the event of an overpressure at the high-pressure connection, the pressure-limiting valve opens and allows fluid to flow directly from the high-pressure connection to the low-pressure connection until the overpressure at the high-pressure connection decreases.
[0026] Particularly preferably, the supply unit has a seventh check valve and an eighth check valve. The seventh check valve is connected to the low-pressure connection at the thirteenth check valve connection, and is connected to the first pump connection at the fourteenth check valve connection. The seventh check valve is designed to prevent the fluid from flowing from the fourteenth check valve connection to the thirteenth check valve connection, and to allow the fluid to flow from the thirteenth check valve connection to the fourteenth check valve connection. The eighth check valve is connected to the low-pressure connection at the fifteenth check valve connection, and is connected to the second pump connection at the sixteenth check valve connection. The eighth check valve is designed to prevent the fluid from flowing from the sixteenth check valve connection to the fifteenth check valve connection, and to allow the fluid to flow from the fifteenth check valve connection to the sixteenth check valve connection. Therefore, the function of the supply unit can be realized reliably and with the help of simple hydraulic components. This reduces the complexity and manufacturing costs of the hydraulic circuit.
[0027] Advantageously, the supply unit is designed as a dual-pressure valve. This reduces the number of components required in the hydraulic circuit and allows a more compact design of the hydraulic circuit.
[0028] Further details, advantages and features of the invention are apparent from the following description of exemplary embodiments with the aid of the accompanying drawings. In the drawings:
[0029] Figure 1 shows a schematic diagram of a hydraulic circuit according to a first embodiment of the present invention,
[0030] Figure 2 shows a schematic diagram of a hydraulic circuit according to a second embodiment of the present invention,
[0031] Figure 3 shows a schematic diagram of a hydraulic circuit according to a third embodiment of the present invention,
[0032] Figure 4 shows a schematic diagram of a hydraulic circuit according to a fourth embodiment of the present invention,
[0033] Figure 5 shows a schematic diagram of a hydraulic circuit according to a fifth embodiment of the present invention,
[0034] Figure 6 shows a schematic diagram of a hydraulic circuit according to a sixth embodiment of the present invention,
[0035] Figure 7 shows a schematic diagram of a hydraulic circuit according to a seventh embodiment of the present invention,
[0036] Figure 8 A schematic diagram showing a hydraulic circuit according to an eighth embodiment of the present invention, and
[0037] Fig. 9 A schematic diagram showing a hydraulic circuit according to a ninth embodiment of the present invention is shown. DETAILED DESCRIPTION
[0038] Figure 1 A schematic diagram of a hydraulic circuit according to a first embodiment of the present invention is shown.
[0039] The hydraulic circuit 1 comprises a high-pressure connection 2, a low-pressure connection 3, a supply unit 4 and a pump system 5. The low-pressure connection 3 is fluidically connected to the high-pressure connection 2 by means of a series connection of the supply unit 4 and the pump system 5. The pump system 5 has a pump 6 for conveying a fluid, a shaft 7 for driving the pump 6 and an unlockable check valve system 8. The pump 6 is configured to convey a fluid from a first pump connection 6a to a second pump connection 6b in a first state and to convey a fluid from a second pump connection 6b to a first pump connection 6a in a second state. The check valve system 8 is fluidically connected to the second pump connection 6b at a first valve connection 8a and is fluidically connected to the high-pressure connection 2 at a second valve connection 8b. The check valve system 8 is designed to prevent a fluid from flowing from the second valve connection 8b to the first valve connection 8a and to allow a fluid to flow from the first valve connection 8a to the second valve connection 8b. The check valve system 8 has a control connection 8c, through which a fluid flow from the second valve connection 8b to the first valve connection 8a can be released. The hydraulic circuit 1 is designed to release the fluid flow from the second valve connection 8b to the first valve connection 8a via the control connection 8c when the pump 6 is in the second state. The supply unit 4 is configured to enable the fluid flow from the low-pressure connection 3 to the first pump connection 6a and prevent the fluid flow from the second pump connection 6b to the low-pressure connection 3 in the first state of the pump 6. The supply unit 4 is configured to enable the fluid flow from the low-pressure connection 3 to the second pump connection 6b and prevent the fluid flow from the first pump connection 6a to the low-pressure connection 3 in the second state of the pump 6. When conveying fluid, the pump 6 has a leakage flow toward the shaft 7. The shaft 7 is connected to the low-pressure connection 3 by means of a pressure equalization line 9 in order to conduct fluid from the shaft 7.
[0040] In the first state, the fluid is sucked in from the low-pressure connection 3 via the first pump connection 6a and delivered to the first valve connection 8a via the second pump connection 6b. The supply unit 4 prevents the fluid from flowing back from the second pump connection 6b to the low-pressure connection 3. Subsequently, the fluid is delivered to the second valve connection 8b and the high-pressure connection 2 via the check valve system 8. Therefore, in the first state, the fluid is delivered from the low-pressure connection 3, through the pump 6 and the check valve system 8 to the high-pressure connection 2, and the pressure of the fluid at the high-pressure connection 2 is increased. Therefore, the fluid can be actively and controllably supplied to the high-pressure connection 2 by means of the control of the pump 6. If the delivery of the pump 6 stops, no more fluid reaches the high-pressure connection 2 from the low-pressure connection 3 through the pump 6 and the check valve system 8. The check valve system 8 prevents the fluid from flowing back from the high-pressure connection 2 through the pump 6 to the low-pressure connection 3.
[0041] In the second state, the fluid is sucked in from the low-pressure connection 3 via the second pump connection 6b and delivered to the control connection 8c of the non-return valve system 8 via the first pump connection 6a. The supply unit 4 prevents the fluid from flowing back from the first pump connection 6a to the low-pressure connection 3. By increasing the pressure at the first control connection 8c, the non-return valve system 8 allows the fluid to flow from the high-pressure connection 2, via the second valve connection 8b, through the non-return valve system 8 and the first valve connection 8a. Therefore, the fluid can be actively and controllably discharged from the high-pressure connection 2 by means of the control of the pump 6, and the pressure of the fluid at the high-pressure connection 2 is reduced.
[0042] When the pump 6 is running, there is a leakage flow of a portion of the delivered fluid in the pump 6 and / or the non-return valve system 8. This leakage flow reaches the shaft 7 of the pump 6 and is led to the low-pressure connection 3 via the pressure balance line 9. The leakage flow in the non-return valve system 8 reaches the low-pressure connection 3 via the first valve connection 8a. By means of the leakage flow, the pump 6 can operate normally and the pressure at the control connection 8c is maintained without damaging the pump 6. Therefore, no line is required between the first pump connection 6a and the control connection 8c. This reduces the complexity of the hydraulic circuit 1.
[0043] The hydraulic circuit 1 has a pressure-limiting valve 19. The pressure-limiting valve 19 is connected to the high-pressure connection 2 at a first pressure-limiting valve connection 19a and to the low-pressure connection 3 at a second pressure-limiting valve connection 19a. The pressure-limiting valve 19 is connected to the high-pressure connection 2 and the low-pressure connection 3 in parallel with the pump system 5 and the supply unit 4. In the event of an overpressure at the high-pressure connection 2, the pressure-limiting valve 19 opens and allows fluid to flow directly from the high-pressure connection 2 to the low-pressure connection 3 until the overpressure at the high-pressure connection 2 is reduced.
[0044] The supply unit 4 is designed as a dual-pressure valve 22. This reduces the number of components required in the hydraulic circuit 1 and allows a more compact design of the hydraulic circuit 1.
[0045] Figure 2 A schematic diagram of a hydraulic circuit 1 according to a second embodiment of the present invention is shown.
[0046] Figure 2 The second embodiment is based on Figure 1 Similar features to the first embodiment.
[0047] Additionally, the check valve system 8 has an unlockable first check valve 10. The unlockable first check valve 10 is connected to the first valve connection 8a at a first check valve connection 10a, and is connected to the second valve connection 8b at a second check valve connection 10b. The unlockable first check valve 10 is designed to prevent the fluid from flowing from the second check valve connection 10b to the first check valve connection 10a, and to allow the fluid to flow from the first check valve connection 10a to the second check valve connection 10b. This allows efficient pressure increase at the high-pressure connection 2 in the first state, because no additional hydraulic elements are arranged between the first valve connection 8a and the second valve connection 8b, which would form a hydraulic resistance.
[0048] The unlockable first check valve 10 has a first check valve control connection 10c, through which a fluid flow from the second check valve connection 10b to the first check valve connection 10a can be released. The first check valve control connection 10c is fluidically connected to the control connection 8c. Therefore, the function of the check valve system 8 can be realized by means of a single check valve 10, and the system complexity of the hydraulic circuit can be kept low.
[0049] Figure 3 A schematic diagram of a hydraulic circuit 1 according to a third embodiment is shown. The third embodiment is based on similar features to the second embodiment.
[0050] The check valve 10 has a working chamber 10d, a piston 10e and a check element 10f. The check element 10f is configured to prevent the fluid from flowing from the second check valve joint 10b to the first check valve joint 10a in the third state of the check element 10f. The check element 10f is configured to release the fluid flow from the second check valve joint 10b to the first check valve joint 10a in the fourth state of the check element 10f. The piston 10e is configured to move in the first direction and place the check element 10f in the fourth state when a fluid flows into the working chamber 10d via the control joint 8c and the fluid increases the pressure in the working chamber 10d. The check valve 10 has a leakage flow flowing through the working chamber 10d between the check valve control joint 10c and the first check valve joint 10a. Through the above-mentioned design of the working chamber and the piston, an additional line can be omitted to transport the leakage flow. This simplifies the manufacture of the hydraulic circuit 1. Figure 4 A schematic diagram of a hydraulic circuit 1 according to a fourth embodiment of the present invention is shown. Figure 4 The fourth embodiment is based on Figure 3 Similar features to the third embodiment.
[0051] Furthermore, the non-return valve system 8 has a first throttle valve 11. The first throttle valve 11 is directly connected to the second valve connection 8b. The first non-return valve 10 and the first throttle valve 11 are connected in series with each other in a fluid manner. This allows a slower fluid flow from the high-pressure connection 2 through the first throttle valve 11 and the first non-return valve 10. By means of this slower fluid flow, the fluid flow and thus the pressure reduction at the high-pressure connection 2 can be controlled more simply.
[0052] The check valve system 8 has a second check valve 12 and a third valve connection 8d. The third valve connection 8d is fluidically connected to the second pump connection 6b. The second check valve 12 is connected to the third valve connection 8d at the third check valve connection 12a, and is connected to the second valve connection 8b at the fourth check valve connection 12b. The second check valve 12 is designed to prevent fluid from flowing from the fourth check valve connection 12b to the third check valve connection 12a, and to allow fluid to flow from the third check valve connection 12a to the fourth check valve connection 12b.
[0053] Therefore, in the check valve system 8, the first hydraulic path between the first valve connector 8a and the second valve connector 8b and the second hydraulic path between the third valve connector 8d and the second valve connector 8b can be formed independently of each other. The second hydraulic path only allows the fluid flow to the second valve connector 8b and the high-pressure connector 2 through the second check valve 12 and thus allows the pressure increase at the high-pressure connector 2. In addition, by means of the first hydraulic path, the fluid can be delivered to the high-pressure connector 2 through the first check valve 10 and thus the pressure at the high-pressure connector 2 is increased. By the parallel arrangement of the first check valve 10 and the second check valve 12 in a fluid sense, the fluid resistance between the second pump connector 6b and the high-pressure connector 2 is reduced and the efficiency of the hydraulic circuit 1 is improved.
[0054] Fluid cannot be led away from the high-pressure connection 2 via the second hydraulic path and thus reduce the pressure. In the second state, the first hydraulic path allows a fluid flow from the high-pressure connection 2 via the unlockable first non-return valve 10 to the first valve connection 8a and thus allows a pressure reduction at the high-pressure connection 2. This allows a controlled pressure reduction at the high-pressure connection 2.
[0055] By arranging the first throttle valve 11 between the second valve connection 8b and the second non-return valve connection 10b, the fluid flow via the first hydraulic path and thus the pressure reduction at the high-pressure connection 2 can be slowed down in the second state. This improves the controllability of the pressure reduction at the high-pressure connection 2 during the second state. In addition, the efficiency in terms of pressure increase is improved, because the fluid can also flow from the first pump connection 6a to the high-pressure connection 2 via the second hydraulic path without having to pass through the throttle valve here.
[0056] Figure 5 A schematic diagram showing a hydraulic circuit according to a fifth embodiment of the present invention is shown. Figure 5 The fifth embodiment is based on Figure 4 Similar features to the fourth embodiment.
[0057] In addition, the check valve system 8 has a third check valve 13. The third check valve 13 is fluidically connected to the second valve connection 8b at the fifth check valve connection 13a, and is fluidically connected to the second check valve connection 10b at the sixth check valve connection 13b. The third check valve 13 is designed to prevent the fluid from flowing from the fifth check valve connection 13a to the sixth check valve connection 13b, and to allow the fluid to flow from the sixth check valve connection 13b to the fifth check valve connection 13a. The third check valve 13 is arranged in parallel with the first throttle valve 11 in a fluidic sense.
[0058] In the first state, the fluid flows through the first valve joint 8a, the first check valve 10 and the second valve joint 8b and increases the pressure at the high-pressure joint 2. The fluid flows partially through the third check valve 13 between the first check valve 10 and the second valve joint 8b and partially through the first throttle valve 11. This arrangement forms a smaller fluid resistance to the fluid flow, as if the entire fluid flow only passes through the first throttle valve 11. This arrangement improves the efficiency of the check valve system 8. In the second state, the third check valve 13 prevents the fluid from flowing from the fifth check valve joint 13a to the sixth check valve joint 13b. The entire fluid flow flows from the high-pressure joint 2 via the second valve joint 8b through the first throttle valve 11, the first check valve 10 and the first valve joint 8a. Because the entire fluid flow flows through the first throttle valve 11 between the second valve joint 8b and the first valve joint 8a, the entire fluid flow slows down. This simplifies the control of the pressure reduction at the high-pressure joint. Therefore, this embodiment allows efficient pressurization at the high-pressure joint 2 and better controllability of the pressure reduction.
[0059] Figure 6 A schematic diagram showing a hydraulic circuit according to a sixth embodiment of the present invention is shown. Figure 6 The sixth embodiment is based on Figure 2 The second embodiment and / or Figure 3 Similar features to the third embodiment.
[0060] The check valve system 8 has a second throttle valve 15, a fourth check valve 14 and a fifth check valve 16. The second throttle valve 15, the fourth check valve 14 and the fifth check valve 16 are arranged between the first check valve 10 and the first valve connection 8a in a fluid sense. The fourth check valve 14 is fluidically connected to the first check valve connection 10a at the seventh check valve connection 14b, and is fluidically connected to the first valve connection 8a at the eighth check valve connection 14a. The fourth check valve 14 is designed to prevent the fluid from flowing from the seventh check valve connection 14b to the eighth check valve connection 14a, and to allow the fluid to flow from the eighth check valve connection 14a to the seventh check valve connection 14b.
[0061] The fifth check valve 16 is arranged in anti-parallel with the fourth check valve 14. The fifth check valve 16 is fluidically connected to the first check valve connection 10a at the ninth check valve connection 16a, and is fluidically connected to the first valve connection 8a at the tenth check valve connection 16b. The fifth check valve 16 is designed to prevent the fluid from flowing from the tenth check valve connection 16b to the ninth check valve connection 16a, and to allow the fluid to flow from the ninth check valve connection 16a to the tenth check valve connection 16b. The second throttle valve 15 is arranged between the tenth check valve connection 16b and the second valve connection 8b in a fluid sense and is arranged in parallel with the fourth check valve 14.
[0062] In the first state, the fluid flows from the first pump connection 6a through the fourth check valve 14 and the first check valve 10 to the high-pressure connection 2, and the pressure at the high-pressure connection 2 is increased. In the first state, the orientation of the fifth check valve 16 prevents the flow of fluid via the fifth check valve 16 and thus via the second throttle valve 15. This allows high efficiency in the first state, because no losses due to the second throttle valve 15 occur. In the second state, the fluid flows from the high-pressure connection 2 through the fifth check valve 16 and the second throttle valve 15 to the first valve connection 8a. In the second state, the fourth check valve 14 blocks the fluid flow, and all the fluid flows through the fifth check valve 16 and the second throttle valve 15. The second throttle valve 15 decelerates the fluid flow, so that the fluid flow can be controlled more simply in the second state. Therefore, this embodiment allows an efficient pressure increase at the high-pressure connection 2 in the first state and an easily controllable pressure reduction at the high-pressure connection 2 in the second state.
[0063] Figure 7 A schematic diagram showing a hydraulic circuit according to a seventh embodiment of the present invention is shown.
[0064] Figure 7 The seventh embodiment is based on Figure 1 Similar features to the first embodiment.
[0065] In addition, the check valve system 8 has a first check valve 10, a fourth valve connection 8e, an unlockable sixth check valve 18 and a third throttle valve 17. The first check valve 10 is connected to the first valve connection 8a at the first check valve connection 10a, and is connected to the second valve connection 8b at the second check valve connection 10b. The first check valve 10 is designed to prevent the fluid from flowing from the second check valve connection 10b to the first check valve connection 10a, and to allow the fluid to flow from the first check valve connection 10a to the second check valve connection 10b.
[0066] The fourth valve connector 8e is fluidically connected to the low-pressure connector 3. The sixth check valve 18 is fluidically connected to the fourth valve connector 8e through the eleventh check valve connector 18a and is fluidically connected to the second valve connector 8b through the twelfth check valve connector 18b. The sixth check valve 18 is designed to prevent the fluid from flowing from the twelfth check valve connector 18b to the eleventh check valve connector 18a, and to allow the fluid to flow from the eleventh check valve connector 18a to the twelfth check valve connector 18b. The sixth check valve 18 has a second check valve control connector 18c, through which the fluid flow from the twelfth check valve connector 18b to the eleventh check valve connector 18a can be released. The second check valve control connector 18c is fluidically connected to the control connector 8c.
[0067] In the first state, the fluid flows to the high-pressure connector 2 via the first valve connector 8a and the second valve connector 8b through the first check valve and increases the pressure at the high-pressure connector 2. Here, no fluid flows through the third throttle valve 17 or other throttle valves. In the second state, the first check valve 10 prevents the fluid from flowing from the second valve connector 8b to the first valve connector 8a. The fluid flows from the first pump connector 6a to the second check valve control connector 18c via the control connector 8c. As a result, the sixth check valve 18 allows the fluid to flow from the high-pressure connector 2 via the second valve connector 8b and the fourth valve connector 8e to the low-pressure connector 3, and thus decompression can be achieved. Here, the fluid flows through the third throttle valve 17 and is decelerated. This improves the controllability of the decompression at the high-pressure connector 2 without negatively affecting the efficiency of the pressurization at the high-pressure connector 2.
[0068] Figure 8 A schematic diagram showing a hydraulic circuit according to an eighth embodiment of the present invention is shown.
[0069] Figure 8 The eighth embodiment is based on Figure 1 Similar features to the first embodiment.
[0070] In addition, the check valve system 8 has a first check valve 10. The first check valve is connected to the first valve connection 8a at the first check valve connection 10a, and is connected to the second valve connection 8b at the second check valve connection 10b. The first check valve 10 is designed to prevent the fluid from flowing from the second check valve connection 10b to the first check valve connection 10a, and to allow the fluid to flow from the first check valve connection 10a to the second check valve connection 10b. This allows efficient pressure increase at the high-pressure connection 2 in the first state, because no additional hydraulic elements are arranged between the first valve connection 8a and the second valve connection 8b, which would form a hydraulic resistance.
[0071] The check valve system 8 has a fourth valve connector 8e, an unlockable sixth check valve 18 and a third throttle valve 17. The fourth valve connector 8e is fluidly connected to the low-pressure connector 3. The sixth check valve 18 is fluidly connected to the fourth valve connector 8e at the eleventh check valve connector 18a and is fluidly connected to the second valve connector 8b via the twelfth check valve connector 18b. The sixth check valve 18 is designed to prevent the fluid from flowing from the twelfth check valve connector 18b to the eleventh check valve connector 18a, and to allow the fluid to flow from the eleventh check valve connector 18a to the twelfth check valve connector 18b. The sixth check valve 18 has a second check valve control connector 18c, through which the fluid flow from the twelfth check valve connector 18b to the eleventh check valve connector 18a can be released. The second check valve control connector 18c is fluidly connected to the control connector 8c.
[0072] In the first state, the fluid flows to the high-pressure connection 2 through the first valve connector 8a, the first check valve 10 and the second valve connector 8b and increases the pressure at the high-pressure connection 2. In this case, no fluid flows through the third throttle valve 17. In the second state, the first check valve 10 prevents the fluid from flowing from the second valve connector 8b to the first valve connector 8a. The fluid flows from the first pump connector 6a to the second check valve control connector 18c via the control connector 8c. As a result, the sixth check valve 18 allows the fluid to flow from the high-pressure connector 2 to the low-pressure connector 3 via the second valve connector 8b and the fourth valve connector 8e, and thus decompression can be achieved. In this case, the fluid also flows through the third throttle valve 17 and is decelerated. This improves the controllability of the decompression at the high-pressure connector 2 without negatively affecting the efficiency of the pressurization at the high-pressure connector 2.
[0073] Fig. 9 A schematic diagram showing a hydraulic circuit according to a ninth embodiment of the present invention is shown.
[0074] Fig. 9 The ninth embodiment is Figure 8 The ninth embodiment has an alternative design of the supply unit 4. In the ninth embodiment, the supply unit 4 is designed as a dual-pressure valve 22 instead of the seventh check valve 20 and the eighth check valve 21. This reduces the number of components required in the hydraulic circuit 1 and allows a more compact construction of the hydraulic circuit 1.
[0075] In addition to the above written description of the invention, reference is hereby made expressly to Figures 1 to 8 The illustrations of the present invention in the accompanying drawings are provided to supplement the disclosure.
[0076] List of Reference Numerals
[0077] 1 Hydraulic circuit
[0078] 2 High pressure connector
[0079] 3 Low pressure connector
[0080] 4 Supply unit
[0081] 5 Pump system
[0082] 6 Pumps
[0083] 6a First pump connector
[0084] 6b Second pump connector
[0085] 7 Axis
[0086] 8 Check valve system
[0087] 8a First valve connector
[0088] 8b Second valve connector
[0089] 8c Control connector
[0090] 8d Third valve connector
[0091] 8e Fourth valve connector
[0092] 9 Pressure balance line
[0093] 10 First check valve
[0094] 10a First check valve connector
[0095] 10b Second check valve connector
[0096] 10c First check valve control connector
[0097] 10d working chamber
[0098] 10e Piston
[0099] 10f Non-return element
[0100] 11 First throttle valve
[0101] 12 Second check valve
[0102] 12a Third check valve connector
[0103] 12b Fourth check valve connector
[0104] 13 Third check valve
[0105] 13a Fifth check valve connector
[0106] 13b Sixth check valve connector
[0107] 14 Fourth check valve
[0108] 14a Eighth check valve connector
[0109] 14b Seventh check valve connector
[0110] 15 Second throttle valve
[0111] 16 Fifth check valve
[0112] 16a Ninth check valve connector
[0113] 16b Tenth check valve connector
[0114] 17 Third throttle valve
[0115] 18 Sixth check valve
[0116] 18a Eleventh check valve connector
[0117] 18b 12th check valve connector
[0118] 18c Second check valve control connector
[0119] 19 Pressure limiting valve
[0120] 19a First pressure limiting valve connector
[0121] 19b Second pressure limiting valve connector
[0122] 20 Seventh check valve
[0123] 20a Thirteenth check valve connector
[0124] 20b Fourteenth check valve connector
[0125] 21 Eighth check valve
[0126] 21a Fifteenth check valve connector
[0127] 21b Sixteenth check valve connector
[0128] 22 Dual pressure valve
Claims
1. A hydraulic circuit (1), comprising: High pressure connector (2), Low pressure connector (3), a supply unit (4), and Pump system (5), ·in, The low-pressure connection (3) is fluidically connected to the high-pressure connection (2) by means of a series connection of the supply unit (4) and the pump system (5). wherein the pump system (5) comprises a pump (6) for conveying a fluid, a shaft (7) for driving the pump (6) and at least one unlockable check valve system (8), wherein the pump (6) is configured to: in a first state, deliver the fluid from the first pump connector (6a) to the second pump connector (6b); and in a second state, deliver the fluid from the second pump connector (6b) to the first pump connector (6a), wherein the non-return valve system (8) is fluidically connected to the second pump connection (6b) at a first valve connection (8a) and is fluidically connected to the high-pressure connection (2) at a second valve connection (8b), wherein the check valve system (8) is designed to prevent fluid from flowing from the second valve connector (8b) to the first valve connector (8a), and to allow fluid to flow from the first valve connector (8a) to the second valve connector (8b), wherein the non-return valve system (8) has a control connection (8c) through which a fluid flow from the second valve connection (8b) to the first valve connection (8a) can be released, wherein the hydraulic circuit (1) is designed to release the fluid flow from the second valve connection (8b) to the first valve connection (8a) through the control connection (8c) when the pump (6) is in the second state, wherein the supply unit (4) is configured to: in a first state of the pump (6), enable a fluid flow from the low-pressure connection (3) to the first pump connection (6a) and prevent a fluid flow from the second pump connection (6b) to the low-pressure connection (3), wherein the supply unit (4) is configured to enable, in the second state of the pump (6), a fluid flow from the low-pressure connection (3) to the second pump connection (6b) and to prevent a fluid flow from the first pump connection (6a) to the low-pressure connection (3), ·in o When conveying the fluid, the pump (6) has a leakage flow toward the shaft (7), and the shaft (7) is connected to the low-pressure connection (3) by means of a pressure equalization line (9) in order to conduct the fluid from the shaft (7), and / or o When the pump (6) is in the second state, the non-return valve system (8) has a leakage flow between the control connection (8c) and the first valve connection (8a).
2. The hydraulic circuit (1) according to claim 1, characterized in that The non-return valve system (8) comprises at least one first non-return valve (10), wherein the first check valve (10) is connected to the first valve connector (8a) at a first check valve connector (10a) and is connected to the second valve connector (8b) at a second check valve connector (10b), and Wherein, the first check valve (10) is designed to prevent fluid from flowing from the second check valve joint (10b) to the first check valve joint (10a), and to allow fluid to flow from the first check valve joint (10a) to the second check valve joint (10b).
3. The hydraulic circuit (1) according to claim 2, characterized in that The first check valve (10) is designed to be unlockable. ·in, The first check valve (10) has a first check valve control connector (10c), through which the fluid flow from the second check valve connector (10b) to the first check valve connector (10a) can be released, and Wherein, the first check valve control joint (10c) is fluidically connected to the control joint (8c).
4. The hydraulic circuit (1) according to any one of claims 2 or 3, characterized in that: The check valve (10) comprises a working chamber (10d), a piston (10e) and a check element (10f). ● wherein the non-return element (10f) is configured to: in a third state of the non-return element (10f), prevent the fluid from flowing from the second non-return valve joint (10b) to the first non-return valve joint (10a), ● wherein the non-return element (10f) is configured to: in a fourth state of the non-return element (10f), release the fluid flow from the second non-return valve connector (10b) to the first non-return valve connector (10a), ● wherein the piston (10e) is configured to: when the working chamber (10d) is pressurized via the control joint (8c), the piston moves in the first direction and places the non-return element (10f) in the fourth state, and ●Wherein, the check valve (10) has a leakage flow flowing through the working chamber (10d) between the check valve control connector (10c) and the first check valve connector (10a).
5. Hydraulic circuit (1) according to any one of the preceding claims, characterized in that The non-return valve system (8) has at least one first throttle valve (11), ·in, The first throttle valve (11) is arranged between the first valve connection (8a) and the second valve connection (8b), and Wherein, the first check valve (10) and the first throttle valve (11) are fluidically connected to each other in series.
6. The hydraulic circuit (1) according to any one of claims 2 and 4, characterized in that The non-return valve system (8) comprises at least one second non-return valve (12) and a third valve connection (8d). ·in, The third valve connector (8d) is fluidically connected to the second pump connector (6b), wherein the second check valve (12) is connected to the third valve connector (8d) at a third check valve connector (12a) and is connected to the second valve connector (8b) at a fourth check valve connector (12b), and The second check valve (12) is designed to prevent fluid from flowing from the fourth check valve joint (12b) to the third check valve joint (12a), and to allow fluid to flow from the third check valve joint (12a) to the fourth check valve joint (12b).
7. The hydraulic circuit (1) according to any one of claims 5 and 6, characterized in that The non-return valve system (8) comprises a third non-return valve (13), wherein the third check valve (13) is fluidically connected to the second valve connector (8b) via a fifth check valve connector (13a) and is fluidically connected to the second check valve connector (10b) via a sixth check valve connector (13b), wherein the third check valve (13) is designed to prevent fluid from flowing from the fifth check valve joint (13a) to the sixth check valve joint (13b), and to allow fluid to flow from the sixth check valve joint (13b) to the fifth check valve joint (13a), and The third nonreturn valve (13) is arranged fluidically parallel to the first throttle valve (11).
8. The hydraulic circuit (1) according to any one of claims 3 to 7, characterized in that The check valve system (8) comprises a second throttle valve (15), a fourth check valve (14) and a fifth check valve (16). wherein the second throttle valve (15), the fourth check valve (14) and the fifth check valve (16) are arranged fluidically between the first check valve (10) and the first valve connection (8a), wherein the fourth check valve (14) is fluidically connected to the first check valve connector (10a) at a seventh check valve connector (14b) and is fluidically connected to the first valve connector (8a) at an eighth check valve connector (14a), wherein the fourth check valve (14) is designed to prevent fluid from flowing from the seventh check valve joint (14b) to the eighth check valve joint (14a), and to allow fluid to flow from the eighth check valve joint (14a) to the seventh check valve joint (14b), wherein the fifth check valve (16) is arranged in anti-parallel with the fourth check valve (14), wherein the fifth check valve (16) is fluidically connected to the first check valve connector (10a) at a ninth check valve connector (16a) and is fluidically connected to the first valve connector (8a) at a tenth check valve connector (16b), wherein the fifth check valve (16) is designed to prevent fluid from flowing from the tenth check valve joint (16b) to the ninth check valve joint (16a), and to allow fluid to flow from the ninth check valve joint (16a) to the tenth check valve joint (16b), and The second throttle valve (15) is arranged fluidically between the tenth non-return valve connection (16b) and the second valve connection (8b) and in parallel with the fourth non-return valve (14).
9. The hydraulic circuit (1) according to claim 2, characterized in that The non-return valve system (8) has a fourth valve connection (8e), an unlockable sixth non-return valve (18) and a third throttle valve (17). Wherein, the fourth valve connector (8e) is fluidically connected to the low-pressure connector (3), wherein the sixth check valve (18) is fluidically connected to the fourth valve connector (8e) via an eleventh check valve connector (18a) and is fluidically connected to the second valve connector (8b) via a twelfth check valve connector (18b), and wherein the sixth check valve (18) is designed to prevent fluid from flowing from the twelfth check valve joint (18b) to the eleventh check valve joint (18a), and to allow fluid to flow from the eleventh check valve joint (18a) to the twelfth check valve joint (18b), wherein the sixth check valve (18) has a second check valve control connector (18c), through which the fluid flow from the twelfth check valve connector (18b) to the eleventh check valve connector (18a) can be released, and Wherein, the second check valve control connector (18c) is fluidically connected to the control connector (8c).
10. Hydraulic circuit (1) according to any one of the preceding claims, characterized in that A pressure limiting valve (19), wherein the pressure limiting valve (19) is connected to the high-pressure connection (2) at a first pressure limiting valve connection (19a) and is connected to the low-pressure connection (3) at a second pressure limiting valve connection (19b), wherein the pressure limiting valve (19) is connected to the high-pressure connection (2) and the low-pressure connection (3) in parallel with the pump system (5) and the supply unit.
11. Hydraulic circuit (1) according to any one of the preceding claims, characterized in that The supply unit has a seventh check valve (20) and an eighth check valve, wherein the seventh check valve (20) is connected to the low-pressure connector (3) at the thirteenth check valve connector (20a), and is connected to the first pump connector (6a) at the fourteenth check valve connector (20b), wherein the seventh check valve (20) is designed to prevent fluid from flowing from the fourteenth check valve joint (20b) to the thirteenth check valve joint (20a), and to allow fluid to flow from the thirteenth check valve joint (20a) to the fourteenth check valve joint (20b), wherein the eighth check valve (21) is connected to the low-pressure connector (3) at the fifteenth check valve connector (21a), and is connected to the second pump connector (6b) at the sixteenth check valve connector (21b), ·Wherein, the eighth check valve (21) is designed to prevent the fluid from flowing from the sixteenth check valve joint (21b) to the fifteenth check valve joint (21a), and to allow the fluid to flow from the fifteenth check valve joint (21a) to the sixteenth check valve joint (21b).
12. Hydraulic circuit (1) according to any one of the preceding claims, characterized in that The supply unit (4) is designed as a dual-pressure valve (22).