Hydraulic system and control method thereof

Abstract

The invention provides a hydraulic system and a control method thereof, and relates to the field of hybrid power transmissions.The hydraulic system comprises an oil supply subsystem used for outputting hydraulic oil; the clutch control subsystem is connected with the oil supply subsystem and used for clutch combination control; the cooling subsystem is connected with the oil supply subsystem and is used for performing clutch cooling control and driving motor cooling control; the one-way oil way is connected with the clutch control subsystem and the cooling subsystem and used for transmitting hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not combined. On the premise that a basic transmission hydraulic system is not changed, the clutch control function, the clutch cooling function and the driving motor cooling function are achieved, cost is low, and the generalization degree is high.

Description

Technical Field

[0001] The present application relates to the technical field of hybrid transmissions, and in particular to a hydraulic system and a control method thereof. Background Art

[0002] With the increasing awareness of environmental protection and the requirements for fuel economy, the energy consumption and emission standards for automobiles are becoming more and more stringent worldwide. This has prompted automakers to continuously seek innovative technologies to improve vehicle energy efficiency and reduce emissions. As an effective solution, hybrid vehicles have become an important development direction of the automotive industry by combining the advantages of internal combustion engines and electric motors.

[0003] In the prior art, hybrid vehicles usually use complex hydraulic systems to achieve clutch control and cooling, as well as cooling of the drive motor. These systems often require a lot of modifications to the basic transmission hydraulic system to adapt to the needs of the hybrid module. These modifications not only increase the complexity and cost of the system, but also reduce the commonality of parts. Summary of the invention

[0004] The purpose of this application is to provide a hydraulic system and a control method thereof to address the deficiencies in the above-mentioned prior art, so as to realize the clutch control function, clutch cooling function and drive motor cooling function without changing the basic transmission hydraulic system, and with low cost and high degree of commonality.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a hydraulic system, comprising: an oil supply subsystem, which is used to output hydraulic oil; a clutch control subsystem, which is connected to the oil supply subsystem and is used to perform clutch engagement control; a cooling subsystem, which is connected to the oil supply subsystem and is used to perform clutch cooling control and drive motor cooling control; a one-way oil circuit, which respectively connects the clutch control subsystem and the cooling subsystem, and is used to transfer the hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not engaged.

[0007] The hydraulic system provided in the above embodiment, by introducing an independent control subsystem and cooling subsystem, is specifically used for the control and cooling of the hybrid power module, and realizes the clutch control function, clutch cooling function and drive motor cooling function, without the need to modify the existing basic transmission hydraulic system, thereby improving the compactness and maintenance convenience of the system, increasing the commonality of parts, and reducing product costs. The system connects the clutch control subsystem and the cooling subsystem through a one-way oil circuit, and transmits the hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not engaged, thereby improving the cooling efficiency of the system.

[0008] In one embodiment, the hydraulic system further includes: a safety oil circuit, which connects the clutch control subsystem and the cooling subsystem and is used to transfer excess oil of the clutch control subsystem to the cooling subsystem during the clutch pressure holding stage.

[0009] The above embodiment prevents excessive system pressure through the design of a safety oil circuit, thereby avoiding damage to system components, and can transfer excess oil from the clutch control subsystem to the cooling subsystem during the clutch pressure maintaining stage, thereby improving the cooling efficiency of the system.

[0010] In one embodiment, the oil supply subsystem includes: a first oil pump, connected to the clutch control subsystem, for supplying oil to the clutch control subsystem; a second oil pump, connected to the cooling subsystem, for supplying oil to the cooling subsystem; an oil pump motor connected to the first oil pump and the second oil pump, for providing power to the first oil pump and the second oil pump; an oil pan connected to the first oil pump and the second oil pump, and the oil pan is used to store hydraulic oil.

[0011] The hydraulic system provided in the above embodiment ensures a stable supply of hydraulic oil through a dual oil pump design, and the motor provides power to the two oil pumps at the same time, thereby improving energy utilization efficiency.

[0012] In one embodiment, the clutch control subsystem includes: a clutch control valve, which is connected to the first oil pump through a first oil circuit and to the cooling subsystem through the one-way oil circuit; a clutch control unit, which is connected to the clutch control valve through a second oil circuit, and the clutch control valve is used to control whether oil is supplied to the clutch control unit.

[0013] The above-mentioned embodiment can effectively perform clutch control through the clutch control subsystem, and simultaneously cooperate with the cooling subsystem to achieve efficient operation of the entire hydraulic system.

[0014] In one embodiment, the clutch control valve has at least two working positions: when the clutch control valve is in the first working position, the first oil port of the clutch control valve is connected to the third oil port, and the second oil port is connected to the fourth oil port;

[0015] When the clutch control valve is in the second working position, the first oil port of the clutch control valve is connected to the second oil port, and the third oil port and the fourth oil port are not connected to other oil ports;

[0016] The first oil pump is connected to the first oil port through the first oil circuit, the clutch control unit is connected to the second oil port through the second oil circuit; the third oil port is connected to the cooling subsystem through the one-way oil circuit.

[0017] The above-mentioned embodiments refine the working position of the clutch control valve and the connection mode of the oil port, as well as the oil circuit connection status when they are in different working positions. The different working positions of the clutch control valve can adapt to different working requirements, thereby improving the adaptability of the system.

[0018] In one embodiment, the clutch control valve includes a first valve core, an electromagnet and a first spring, the first end face of the first valve core is connected to the electromagnet, the second end face of the first valve core is connected to the first spring, and the hydraulic system also includes: a first control oil circuit, the first control oil circuit connects the second oil port and the second end face of the first valve core, for realizing pressure control of the clutch.

[0019] The above embodiment realizes precise control of clutch pressure through the combination of electromagnet and spring, simplifies the operation of clutch control and improves the response speed of the system.

[0020] In one embodiment, the cooling subsystem includes: a cooling flow control valve, which is connected to the second oil pump through a third oil circuit; the one-way oil circuit connects the clutch control subsystem and the third oil circuit; a clutch cooling unit, which is connected to the cooling flow control valve through a fourth oil circuit and is used to receive hydraulic oil for clutch cooling; a motor cooling unit, which is connected to the cooling flow control valve through a fifth oil circuit and is used to receive hydraulic oil for driving motor cooling; the cooling flow control valve is used to adjust the amount of oil reaching the clutch cooling unit and the motor cooling unit.

[0021] The above embodiment achieves efficient cooling of the clutch and the drive motor by adjusting the cooling flow control valve. The system can adjust the oil volume according to the cooling demand, thereby improving the cooling efficiency.

[0022] In one embodiment, the cooling flow control valve has at least three working positions: when the cooling flow control valve is in the first working position, the first oil port of the cooling flow control valve is connected to the third oil port, the second oil port is connected to the fourth oil port, and a second throttle hole is provided in the oil path between the first oil port and the third oil port;

[0023] When the cooling flow control valve is in the second working position, the first oil port of the cooling flow control valve is connected to the third oil port, the second oil port is connected to the fourth oil port, and a first throttling hole is provided in the oil path between the second oil port and the fourth oil port;

[0024] When the cooling flow control valve is in the third working position, the second oil port of the cooling flow control valve is connected to the fourth oil port, and the first oil port, the third oil port and other oil ports are not connected; the first oil port and the second oil port are connected to each other, and are connected to the second oil pump through the third oil circuit; the third oil port is connected to the clutch cooling part through the fourth oil circuit; the fourth oil port is connected to the motor cooling part through the fifth oil circuit.

[0025] The above-mentioned embodiment provides different levels of flow control through multiple working positions of the cooling flow control valve to adapt to different cooling requirements; through the design of the throttle hole, the flow control of the oil is optimized and the energy loss is reduced.

[0026] In one embodiment, the cooling flow control valve includes a second valve core and a second spring, and the second end face of the second valve core is connected to the second spring. The hydraulic system also includes: a second control oil circuit, and the second control oil circuit is connected to the first end face of the second valve core of the cooling flow control valve and a clutch control subsystem, and is used to transmit the clutch control pressure to the first end face of the second valve core of the cooling flow control valve, so that the second valve core overcomes the force of the second spring and moves to control the cooling flow control valve to switch between different working positions.

[0027] The above embodiment realizes flexible control of the cooling flow control valve through the structure of the cooling flow control valve and the setting of the second control oil circuit, and through the pressure transmitted by the second control oil circuit. The system can quickly respond to different working states, and improve the cooling efficiency of the system.

[0028] According to a second aspect of the present application, a control method for a hydraulic system is provided. The method is applied to the hydraulic system described in the above embodiment. The method includes:

[0029] When receiving the instruction of the first working state, the oil supply subsystem supplies oil to the clutch control subsystem and the cooling subsystem, the hydraulic oil of the clutch control subsystem is transmitted to the cooling subsystem through the one-way oil circuit, and the cooling subsystem performs cooling control of the drive motor;

[0030] When receiving the instruction of the second working state, the oil supply subsystem supplies oil to the clutch control subsystem and the cooling subsystem, the clutch control subsystem performs clutch engagement control, and the cooling subsystem performs clutch cooling control and drive motor cooling control;

[0031] When receiving the instruction of the third working state, the oil supply subsystem supplies oil to the clutch control subsystem and the cooling subsystem, the clutch control subsystem performs clutch pressure holding control, and the cooling subsystem performs clutch cooling control and drive motor cooling control.

[0032] The above-mentioned embodiment realizes accurate management of different working states of the hydraulic system through an intelligent control method, can optimize the use of energy according to different working requirements, and improves the energy efficiency of the system.

[0033] The hydraulic system and control method thereof provided in the above-mentioned embodiment, by introducing an independent control subsystem and a cooling subsystem, are specifically used for the control and cooling of the hybrid power module, thereby realizing the clutch control function, the clutch cooling function and the drive motor cooling function. Without changing the basic transmission hydraulic system, the clutch control function, the clutch cooling function and the drive motor cooling function are realized, and the cost is low and the degree of commonality is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram of the structure of a hydraulic system provided in one embodiment of the present application;

[0036] Figure 2 A schematic structural diagram of a first embodiment of a clutch control valve provided in an embodiment of the present application;

[0037] Figure 3 A schematic diagram of the structure of a cooling flow control valve provided in one embodiment of the present application;

[0038] Figure 4 A schematic structural diagram of a second embodiment of a clutch control valve provided in an embodiment of the present application.

[0039] The above drawings include the following reference numerals:

[0040] 1. Oil supply subsystem; 2. Clutch control subsystem; 3. Cooling subsystem; 4. One-way oil circuit; 5. One-way valve; 6. Safety oil circuit; 7. Safety valve; 8. First control oil circuit; 9. Second control oil circuit;

[0041] 11. Oil pan; 12. Filter; 13. Oil pump motor; 14. First oil pump; 15. Second oil pump;

[0042] 21. Clutch control valve; 22. Clutch control unit; 24. Second oil circuit; 211. First oil port; 212. Second oil port; 213. Third oil port; 214. Fourth oil port; 215. First end face of first valve core; 216. Second end face of first valve core; 217. Electromagnet; 218. First spring;

[0043] 31. Cooling flow control valve; 32. Clutch cooling unit; 33. Motor cooling unit; 34. Third oil circuit; 35. Fourth oil circuit; 36. Fifth oil circuit; 311. First oil port; 312. Second oil port; 313. Third oil port; 314. Fourth oil port; 315. Second end face of second valve core; 316. First end face of second valve core; 317. Second spring; 318. First throttle hole; 319. Second throttle hole. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0045] Similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0046] Figure 1 This is a structural schematic diagram of a hydraulic system provided in an embodiment of the present application, wherein the hydraulic system comprises: an oil supply subsystem 1, a clutch control subsystem 2, a cooling subsystem 3 and a one-way oil circuit 4.

[0047] The oil supply subsystem 1 is used to output hydraulic oil. Figure 1As shown, the oil supply subsystem 1 includes: an oil pan 11, a filter 12, an oil pump motor 13, a first oil pump 14 and a second oil pump 15. Among them, the first oil pump 14 is connected to the clutch control subsystem 2, and is used to supply oil to the clutch control subsystem 2. The second oil pump 15 is connected to the cooling subsystem 3, and is used to supply oil to the cooling subsystem 3. The oil pump motor 13 is connected to the first oil pump 14 and the second oil pump 15, and is used to provide power for the first oil pump 14 and the second oil pump 15. The oil pan 11 is connected to the filter 12, and the filter 12 is connected to the first oil pump 14 and the second oil pump 15. The oil pan 11 is used to store hydraulic oil, and the filter 12 is used to remove impurities in the oil to maintain the cleanliness of the oil. Exemplarily, the first oil pump 14 and the second oil pump 15 are connected in rotation, that is, the oil pump motor 13 drives the first oil pump 14 and the second oil pump 15 at the same time, which saves space and makes the hydraulic system more compact.

[0048] The clutch control subsystem 2 is connected to the oil supply subsystem 1 for clutch engagement control. In one embodiment, the clutch control subsystem 2 includes a clutch control valve 21 and a clutch control unit 22. The clutch control valve 21 is connected to the first oil pump 14 through the first oil circuit 23 and to the cooling subsystem 3 through the one-way oil circuit 4; the clutch control unit 22 is connected to the clutch control valve 21 through the second oil circuit 24, and the clutch control valve 21 is used to control whether to supply oil to the clutch control unit 22.

[0049] The cooling subsystem 3 is connected to the oil supply subsystem 1 and is used for clutch cooling control and drive motor cooling control. In one embodiment, the cooling subsystem 3 includes: a cooling flow control valve 31 , a clutch cooling unit 32 and a motor cooling unit 33 .

[0050] The cooling flow control valve 31 is connected to the second oil pump 15 through the third oil circuit 34. The one-way oil circuit 4 connects the clutch control subsystem 2 with the third oil circuit 34. The clutch cooling unit 32 is connected to the cooling flow control valve 31 through the fourth oil circuit 35, and is used to receive hydraulic oil for clutch cooling. The motor cooling unit 33 is connected to the cooling flow control valve 31 through the fifth oil circuit 36, and is used to receive hydraulic oil for driving motor cooling. The cooling flow control valve 31 is used to adjust the amount of oil reaching the clutch cooling unit 32 and the motor cooling unit 33.

[0051] The one-way oil circuit 4 is respectively connected to the clutch control subsystem 2 and the cooling subsystem 3, and is used to transfer the hydraulic oil of the clutch control subsystem 2 to the cooling subsystem 3 when the clutch is not engaged. In one embodiment, a one-way valve 5 is also installed on the one-way oil circuit 4, and the one-way valve 5 is used to ensure that the oil flows from the clutch control subsystem 2 to the cooling subsystem 3 in one direction.

[0052] In one embodiment, the hydraulic system further includes a safety oil circuit 6, which connects the clutch control subsystem 2 and the cooling subsystem 3, and is used to transfer excess oil of the clutch control subsystem 2 to the cooling subsystem 3 during the clutch pressure holding stage.

[0053] In one embodiment, a safety valve 7 is also installed on the safety oil circuit 6, and the safety valve 7 is used to ensure that the system pressure does not exceed the set safety value to ensure the safety of the entire hydraulic system. Exemplarily, the opening pressure of the safety valve 7 is higher than the clutch control pressure.

[0054] In one embodiment, if Figure 1 and Figure 2 As shown, the clutch control valve 21 has at least two working positions:

[0055] When the clutch control valve 21 is in the first working position ( Figure 2 The first oil port 211 of the clutch control valve 21 is connected to the third oil port 213, and the second oil port 212 is connected to the fourth oil port 214;

[0056] When the clutch control valve 21 is in the second working position ( Figure 2 In the right position), the first oil port 211 of the clutch control valve 21 is connected to the second oil port 212, and the third oil port 213 and the fourth oil port 214 are not connected to other oil ports; in another embodiment, as Figure 4 As shown, the third oil port 213 may also be in communication with the fourth oil port 214 .

[0057] The first oil pump 14 is connected to the first oil port 211 through the first oil circuit 23 , the clutch control unit 22 is connected to the second oil port 212 through the second oil circuit 24 ; the third oil port 213 is connected to the cooling subsystem 3 through the one-way oil circuit 4 .

[0058] In one embodiment, if Figure 1 , 2 As shown in Figures 4 and 5, the clutch control valve 21 includes a first valve core, an electromagnet 217 and a first spring 218. The first end face 215 (e.g., the right end face) of the first valve core is connected to the electromagnet 217, and the second end face 216 (e.g., the left end face) of the first valve core is connected to the first spring 218. In one embodiment, the hydraulic system further includes: a first control oil circuit 8, the first control oil circuit 8 connects the second oil port 212 and the second end face 216 of the first valve core, and is used to achieve pressure control of the clutch. Exemplarily, the second oil port 212 is connected to the second end face 216 of the first valve core through the first control oil circuit 8, and the electromagnetic force of the first end face 215 of the first valve core and the hydraulic pressure of the second end face 216 of the first valve core are balanced with each other, so as to achieve pressure control of the clutch.

[0059] In one embodiment, if Figure 1 and Figure 3 As shown, the cooling flow control valve 31 has at least three working positions:

[0060] When the cooling flow control valve 31 is in the first working position ( Figure 3 The first oil port 311 of the cooling flow control valve 31 is connected to the third oil port 313, the second oil port 312 is connected to the fourth oil port 314, and a second throttling hole 319 is provided in the oil circuit between the first oil port 311 and the third oil port 313.

[0061] When the cooling flow control valve 31 is in the second working position ( Figure 3 The first oil port 311 of the cooling flow control valve 31 is connected to the third oil port 313, the second oil port 312 is connected to the fourth oil port 314, and a first throttling hole 318 is provided in the oil circuit between the second oil port 312 and the fourth oil port 314.

[0062] When the cooling flow control valve 31 is in the third working position ( Figure 3 The second oil port 312 of the cooling flow control valve 31 is connected to the fourth oil port 314, and the first oil port 311 and the third oil port 313 are not connected to other oil ports.

[0063] The first oil port 311 and the second oil port 312 are connected to each other and to the second oil pump 15 via the third oil path 34 ; the third oil port 313 is connected to the clutch cooling unit 32 via the fourth oil path 35 ; the fourth oil port 314 is connected to the motor cooling unit 33 via the fifth oil path 36 .

[0064] In one embodiment, the cooling flow control valve includes a second valve core and a second spring 317, and a second end surface 315 (e.g., a right end surface) of the second valve core is connected to the second spring 317. Further, the hydraulic system also includes a second control oil circuit 9, which is connected to a first end surface 316 (e.g., a left end surface) of the second valve core of the cooling flow control valve 31 and the clutch control subsystem 2, and is used to transmit the clutch control pressure to the first end surface 316 of the second valve core of the cooling flow control valve 31, so that the second valve core overcomes the force of the second spring 317 and moves, so as to control the cooling flow control valve 31 to switch between different working positions.

[0065] According to another aspect of the present invention, a control method for a hydraulic system is provided, which can at least achieve the following working states:

[0066] When receiving the instruction of the first working state, the oil supply subsystem 1 supplies oil to the clutch control subsystem 2 and the cooling subsystem 3, and the hydraulic oil of the clutch control subsystem 2 is transmitted to the cooling subsystem 3 through the one-way oil circuit 4, and the cooling subsystem 3 performs cooling control of the drive motor.

[0067] Specifically, in the first working state, the vehicle is in a pure electric driving condition, the clutch is not engaged, and only the drive motor needs to be cooled, and only cooling oil needs to be provided to the drive motor to achieve the drive motor cooling function. At this time, the electromagnet 217 is not energized, and the clutch control valve 21 is in the first working position ( Figure 2 The cooling flow control valve 31 is in the third working position ( Figure 3 The oil pumped out by the second oil pump 15 flows to the motor cooling portion 33 through the third oil passage 34, the second oil port 312, the fourth oil port 314 and the fifth oil passage 36.

[0068] The oil pumped out by the first oil pump 14 flows to the motor cooling unit 33 through the first oil circuit 23 , the first oil port 211 , the third oil port 213 , the one-way oil circuit 4 , the one-way valve 5 , the third oil circuit 34 , the second oil port 312 , the fourth oil port 314 , and the fifth oil circuit 36 ​​.

[0069] That is, in this working state, the oil pumped by the first oil pump 14 and the second oil pump 15 is used to cool the drive motor. This control method reduces unnecessary cooling oil flow, thereby reducing energy consumption; on the other hand, since the clutch is not engaged, no cooling oil flows to the clutch, reducing the drag loss of the system, improving the energy utilization efficiency of the whole vehicle, and improving the response speed and cooling efficiency of the system.

[0070] When receiving the instruction of the second working state, the oil supply subsystem 1 supplies oil to the clutch control subsystem 2 and the cooling subsystem 3, the clutch control subsystem 2 performs clutch engagement control, and the cooling subsystem 3 performs clutch cooling control and drive motor cooling control.

[0071] Specifically, in the second working state, the vehicle is in a pure electric to hybrid conversion state, that is, the clutch changes from a disengaged state to an engaged state. At this time, the clutch pressure needs to be precisely controlled to achieve clutch engagement control, clutch cooling, and drive motor cooling functions. At this time, a certain current is applied to the electromagnet 217, and the clutch control valve 21 is in the second working position ( Figure 2 The clutch control pressure acts on the first end face 316 of the second valve core through the second control oil circuit 9, so that the valve core overcomes the force of the second spring 317 and moves, so that the cooling flow control valve 31 is in the second working position ( Figure 3 median of ).

[0072] The oil pumped out by the first oil pump 14 enters the clutch control unit 22 through the first oil circuit 23, the first oil port 211, the second oil port 212, and the second oil circuit 24. At the same time, the second oil port 212 is connected to the second end face 216 of the first valve core through the first control oil circuit 8. The electromagnetic force of the first end face 215 of the first valve core and the hydraulic pressure of the second end face 216 of the first valve core are balanced with each other, so as to realize the pressure control of the clutch. The oil pumped out by the second oil pump 15 reaches the cooling flow control valve 31 through the third oil circuit 34. A part of the oil reaches the clutch cooling unit 32 through the first oil port 311 and the third oil port 313, and another part of the oil reaches the motor cooling unit 33 through the second oil port 312, the first throttle hole 318, and the fourth oil port 314. Since a large cooling flow is required during the clutch engagement process, the first throttle hole 318 is provided to increase the amount of hydraulic oil reaching the clutch cooling unit 32.

[0073] This control method achieves precise control of the clutch from separation to engagement, ensuring stability and reliability during the clutch engagement process; and according to the cooling requirements of the clutch and the drive motor, by setting the first throttle hole 318, the amount of hydraulic oil reaching the clutch cooling part 32 is increased, while maintaining small flow cooling of the motor cooling part 33, thereby achieving optimal distribution of the cooling flow.

[0074] When receiving the instruction of the third working state, the oil supply subsystem 1 supplies oil to the clutch control subsystem 2 and the cooling subsystem 3, the clutch control subsystem 2 performs clutch pressure maintaining control, and the cooling subsystem 3 performs clutch cooling control and drive motor cooling control.

[0075] Specifically, in the third working state, the vehicle is in the hybrid mode. At this time, clutch pressure holding control needs to be implemented. The clutch requires a fixed pressure and a small cooling flow, and the drive motor requires a large cooling flow. At this time, a certain current is applied to the electromagnet 217. Specifically, a current higher than that in the second working state is applied to the electromagnet 217. The clutch control valve 21 is in the second working position ( Figure 2 The clutch control pressure acts on the first end face 316 of the second valve core through the second control oil circuit 9, so that the valve core overcomes the force of the second spring 317 and moves further, so that the cooling flow control valve 31 is in the first working position ( Figure 3 left position in the middle).

[0076] The oil pumped out by the first oil pump 14 enters the clutch control unit 22 through the first oil circuit 23, the first oil port 211, the second oil port 212, and the second oil circuit 24. At this time, the oil pumped out by the first oil pump 14 only needs to supplement the leakage of the clutch control unit 22, and the excess oil reaches the cooling flow control valve 31 through the safety oil circuit 6, the safety valve 7, and the third oil circuit 34. Part of the oil reaches the clutch cooling unit 32 through the first oil port 311, the second throttle hole 319, the third oil port 313, and the fourth oil circuit 35, and the other part of the oil reaches the motor cooling unit 33 through the second oil port 312, the fourth oil port 314, and the fifth oil circuit 36.

[0077] The oil pumped out by the second oil pump 15 reaches the cooling flow control valve 31 through the third oil circuit 34, a part of the oil reaches the clutch cooling part 32 through the first oil port 311, the second throttling hole 319, the third oil port 313, and the fourth oil circuit 35, and the other part of the oil reaches the motor cooling part 33 through the second oil port 312, the fourth oil port 314, and the fifth oil circuit 36. Since very little heat is generated when the clutch is fully engaged, the second throttling hole 319 is provided to increase the amount of hydraulic oil reaching the motor cooling part 33.

[0078] This control method realizes long-term engagement and pressure-maintaining control of the clutch, ensuring the stability of power output, and through the setting of the second throttle hole 319, increases the amount of hydraulic oil reaching the motor cooling part 33, while reducing the leakage of the clutch control part 22, optimizing the overall energy consumption of the system.

[0079] It should be noted that when the clutch control valve 21 is Figure 4 In the corresponding structure, the clutch control valve 21 is in the second working position ( Figure 4 The first oil port 211 is connected to the second oil port 212, and the third oil port 213 is connected to the fourth oil port 214. Since the one-way valve 5 installed on the one-way oil circuit 4 ensures that the oil can only flow from the clutch control subsystem 2 to the cooling subsystem 3 in one direction, even when the third oil port 213 is connected to the fourth oil port 214, the cooling subsystem 3 can be disconnected from the clutch control subsystem 2.

[0080] In summary, the hydraulic system and control method thereof of the present invention have the following advantages:

[0081] Currently, for transmission products that take into account both internal combustion engine drive and hybrid power drive, a hybrid power module is added to the basic transmission structure. Generally, in order to realize the clutch control function, clutch cooling function and drive motor cooling function in the hybrid power module, the original transmission hydraulic control system is changed, which leads to a decrease in the commonality rate of parts and an increase in product costs and production investment.

[0082] When implementing hybrid drive, the current hydraulic system cannot accurately control the cooling flow distribution of the hydraulic system under different working conditions, resulting in the inability to meet the flow requirements for clutch and drive motor cooling, or excessive flow leads to reduced system efficiency and increased system energy consumption.

[0083] The hydraulic system and control method thereof provided in the embodiment of the present invention, by introducing an independent control subsystem and a cooling subsystem, are specifically used for the control and cooling of a hybrid power module, thereby realizing the clutch control function, the clutch cooling function and the drive motor cooling function. Without changing the basic transmission hydraulic system, the clutch control function, the clutch cooling function and the drive motor cooling function are realized, and the cost is low and the degree of commonality is high.

[0084] The system connects the clutch control subsystem and the cooling subsystem through a one-way oil circuit. When the clutch is not engaged, the hydraulic oil of the clutch control subsystem is transferred to the cooling subsystem, so that the clutch control subsystem and the cooling subsystem can work together. Different levels of flow control are provided through multiple working positions of the clutch control valve and the cooling flow control valve. The design of the throttle hole optimizes the flow control of the oil, and can achieve efficient and precise control under different working conditions, optimize the cooling flow distribution, reduce energy consumption and losses, and improve the performance of the vehicle and the driving experience.

[0085] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A hydraulic system, characterized in that: include: An oil supply subsystem (1), the oil supply subsystem (1) being used to output hydraulic oil; A clutch control subsystem (2), the clutch control subsystem (2) being connected to the oil supply subsystem (1) and used for clutch engagement control; A cooling subsystem (3), the cooling subsystem (3) is connected to the oil supply subsystem (1) and is used for clutch cooling control and drive motor cooling control; A one-way oil circuit (4) is respectively connected to the clutch control subsystem (2) and the cooling subsystem (3), and is used to transmit the hydraulic oil of the clutch control subsystem (2) to the cooling subsystem (3) when the clutch is not engaged.

2. The hydraulic system according to claim 1, characterized in that: Also includes: A safety oil circuit (6), wherein the safety oil circuit (6) connects the clutch control subsystem (2) and the cooling subsystem (3), and is used to transfer excess oil of the clutch control subsystem (2) to the cooling subsystem (3) during the clutch pressure holding stage.

3. The hydraulic system according to claim 1, characterized in that: The oil supply subsystem (1) comprises: a first oil pump (14), connected to the clutch control subsystem (2) and used for supplying oil to the clutch control subsystem (2); a second oil pump (15), connected to the cooling subsystem (3) and used for supplying oil to the cooling subsystem (3); An oil pump motor (13), connected to the first oil pump (14) and the second oil pump (15), and used to provide power for the first oil pump (14) and the second oil pump (15); An oil pan (11) is connected to the first oil pump (14) and the second oil pump (15), and the oil pan (11) is used to store hydraulic oil.

4. The hydraulic system according to claim 3, characterized in that: The clutch control subsystem (2) comprises: A clutch control valve (21), wherein the clutch control valve (21) is connected to the first oil pump (14) via a first oil circuit (23), and is connected to the cooling subsystem (3) via the one-way oil circuit (4); A clutch control unit (22) is connected to the clutch control valve (21) via a second oil passage (24), and the clutch control valve (21) is used to control whether to supply oil to the clutch control unit (22).

5. The hydraulic system according to claim 4, characterized in that: The clutch control valve (21) has at least two working positions: When the clutch control valve (21) is in the first working position, the first oil port (211) of the clutch control valve is connected to the third oil port (213), and the second oil port (212) is connected to the fourth oil port (214); When the clutch control valve (21) is in the second working position, the first oil port (211) of the clutch control valve is connected to the second oil port (212), and the third oil port (213) and the fourth oil port (214) are not connected to other oil ports; The first oil pump (14) is connected to the first oil port (211) via the first oil circuit (23); the clutch control unit (22) is connected to the second oil port (212) via the second oil circuit (24); and the third oil port (213) is connected to the cooling subsystem (3) via the one-way oil circuit (4).

6. The hydraulic system according to claim 5, characterized in that: The clutch control valve (21) comprises a first valve core, an electromagnet (217) and a first spring (218), wherein a first end surface (215) of the first valve core is connected to the electromagnet (217), and a second end surface (216) of the first valve core is connected to the first spring (218), and the hydraulic system further comprises: A first control oil circuit (8), wherein the first control oil circuit (8) connects the second oil port (212) and the second end surface (216) of the first valve core, and is used to realize pressure control of the clutch.

7. The hydraulic system according to claim 3, characterized in that: The cooling subsystem (3) comprises: a cooling flow control valve (31), the cooling flow control valve (31) being connected to the second oil pump (15) via a third oil circuit (34); the one-way oil circuit (4) being connected to the clutch control subsystem (2) and the third oil circuit (34); A clutch cooling unit (32), the clutch cooling unit (32) being connected to the cooling flow control valve (31) via a fourth oil passage (35) and being used for receiving hydraulic oil for clutch cooling; a motor cooling unit (33), the motor cooling unit (33) being connected to the cooling flow control valve (31) via a fifth oil passage (36) and being used for receiving hydraulic oil to cool the drive motor; The cooling flow control valve (31) is used to adjust the amount of oil reaching the clutch cooling part (32) and the motor cooling part (33).

8. The hydraulic system according to claim 7, characterized in that: The cooling flow control valve (31) has at least three working positions: When the cooling flow control valve (31) is in the first working position, the first oil port (311) of the cooling flow control valve (31) is in communication with the third oil port (313), the second oil port (312) is in communication with the fourth oil port (314), and a second throttle hole 319 is provided in the oil path between the first oil port (311) and the third oil port (313); When the cooling flow control valve (31) is in the second working position, the first oil port (311) of the cooling flow control valve (31) is in communication with the third oil port (313), the second oil port (312) is in communication with the fourth oil port (314), and a first throttle hole (318) is provided in the oil path between the second oil port (312) and the fourth oil port (314); When the cooling flow control valve (31) is in the third working position, the second oil port (312) of the cooling flow control valve (31) is connected to the fourth oil port (314), and the first oil port (311), the third oil port (313) and other oil ports are not connected; The first oil port (311) and the second oil port (312) are connected to each other and to the second oil pump (15) via the third oil circuit (34); the third oil port (313) is connected to the clutch cooling unit (32) via the fourth oil circuit (35); and the fourth oil port (314) is connected to the motor cooling unit (33) via the fifth oil circuit (36).

9. The hydraulic system according to claim 8, characterized in that: The cooling flow control valve comprises a second valve core and a second spring (317), wherein a second end surface (315) of the second valve core is connected to the second spring (317), and the hydraulic system further comprises: A second control oil circuit (9), wherein the second control oil circuit (9) is connected to the first end face (316) of the second valve core of the cooling flow control valve (31) and the clutch control subsystem (2), and is used to transmit the clutch control pressure to the first end face (316) of the second valve core of the cooling flow control valve (31), so that the second valve core overcomes the force of the second spring (317) and moves, so as to control the cooling flow control valve (31) to switch between different working positions.

10. A method for controlling a hydraulic system, characterized in that: Applied to the hydraulic system according to any one of claims 1 to 9, the method comprises: When receiving the instruction of the first working state, the oil supply subsystem (1) supplies oil to the clutch control subsystem (2) and the cooling subsystem (3), the hydraulic oil of the clutch control subsystem (2) is transmitted to the cooling subsystem (3) through the one-way oil circuit (4), and the cooling subsystem (3) performs cooling control of the drive motor; When receiving the instruction of the second working state, the oil supply subsystem (1) supplies oil to the clutch control subsystem (2) and the cooling subsystem (3), the clutch control subsystem (2) performs clutch engagement control, and the cooling subsystem (3) performs clutch cooling control and drive motor cooling control; When receiving the instruction of the third working state, the oil supply subsystem (1) supplies oil to the clutch control subsystem (2) and the cooling subsystem (3), the clutch control subsystem (2) performs clutch pressure holding control, and the cooling subsystem (3) performs clutch cooling control and drive motor cooling control.

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