Hydraulic system and method of controlling the same

Abstract

The application provides a hydraulic system and a control method thereof, relates to the field of hybrid power transmissions, and comprises an oil supply subsystem for outputting hydraulic oil; a clutch control subsystem connected with the oil supply subsystem and used for clutch combination control; a cooling subsystem connected with the oil supply subsystem and used for clutch cooling control and driving motor cooling control; and a one-way oil path connected with the clutch control subsystem and the cooling subsystem respectively and used for transmitting the hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not combined; the clutch control function, the clutch cooling function and the driving motor cooling function are realized without changing the basic transmission hydraulic system, and the cost is low and the degree of generalization is high.

Description

TECHNICAL FIELD

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

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

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

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a hydraulic system and a control method thereof, which realize clutch control function, clutch cooling function and drive motor cooling function without changing the basic transmission hydraulic system, and have low cost and high generalization degree.

[0005] To achieve the above purpose, the technical solutions adopted by the embodiments of the present application are as follows:

[0006] In a first aspect, the present application provides a hydraulic system, comprising: an oil supply subsystem, configured to output hydraulic oil; a clutch control subsystem connected to the oil supply subsystem, configured to perform clutch engagement control; a cooling subsystem connected to the oil supply subsystem, configured to perform clutch cooling control and drive motor cooling control; and a one-way oil path connected to the clutch control subsystem and the cooling subsystem, respectively, configured to transmit hydraulic oil from the clutch control subsystem to the cooling subsystem when the clutch is not engaged.

[0007] The hydraulic system provided by the above embodiment introduces independent control subsystem and cooling subsystem, which are specially used for control and cooling of the hybrid module, realizes clutch control function, clutch cooling function and driving motor cooling function, without modification of the existing basic transmission hydraulic system, improves the compactness and maintenance convenience of the system, improves the generalization rate of parts, and reduces the product cost. The system connects the clutch control subsystem and the cooling subsystem through a one-way oil path, transmits the hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not combined, and improves the cooling efficiency of the system.

[0008] In an embodiment, the hydraulic system further comprises a safety oil path connecting the clutch control subsystem and the cooling subsystem, for transmitting excess oil of the clutch control subsystem to the cooling subsystem during the clutch pressure maintaining phase.

[0009] The above embodiment prevents the system pressure from being too high through the design of the safety oil path, thereby avoiding damage to the system components, and can transmit excess oil of the clutch control subsystem to the cooling subsystem during the clutch pressure maintaining phase, thereby improving the cooling efficiency of the system.

[0010] In an embodiment, the oil supply subsystem comprises 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, and an oil pan connected to the first oil pump and the second oil pump, the oil pan being used for storing hydraulic oil.

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

[0012] In an embodiment, the clutch control subsystem comprises a clutch control valve connected to the first oil pump through a first oil path and connected to the cooling subsystem through the one-way oil path, and a clutch control part connected to the clutch control valve through a second oil path, the clutch control valve being used for controlling whether to supply oil to the clutch control part.

[0013] The above embodiment can effectively control the clutch through the clutch control subsystem, and cooperates with the cooling subsystem to realize efficient operation of the entire hydraulic system.

[0014] In an 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 with the third oil port, and the second oil port is connected with 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 with the second oil port, and the third oil port and the fourth oil port are not connected with other oil ports;

[0016] The first oil pump is connected with the first oil port through the first oil path, and the clutch control part is connected with the second oil port through the second oil path; the third oil port is connected with the cooling subsystem through the one-way oil path.

[0017] The above embodiment details the working positions of the clutch control valve and the connection modes of the oil ports, as well as the oil path connection states in different working positions. Different working positions of the clutch control valve can adapt to different working requirements, thereby improving the adaptability of the system.

[0018] In an embodiment, the clutch control valve comprises a first valve core, an electromagnet, and a first spring. The first end surface of the first valve core is connected with the electromagnet, and the second end surface of the first valve core is connected with the first spring. The hydraulic system further comprises a first control oil path connected with the second oil port and the second end surface of the first valve core, for realizing pressure control of the clutch.

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

[0020] In an embodiment, the cooling subsystem comprises a cooling flow control valve connected with the second oil pump through a third oil path; the one-way oil path connects the clutch control subsystem with the third oil path; a clutch cooling part connected with the cooling flow control valve through a fourth oil path, for receiving hydraulic oil to cool the clutch; and a motor cooling part connected with the cooling flow control valve through a fifth oil path, for receiving hydraulic oil to cool the driving motor. The cooling flow control valve is used to adjust the oil amount reaching the clutch cooling part and the motor cooling part.

[0021] The above embodiment realizes efficient cooling of the clutch and the driving motor through the adjustment of the cooling flow control valve. The system can adjust the oil amount according to the cooling requirement, thereby improving the cooling efficiency.

[0022] In an 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 in communication with the third oil port, the second oil port is in communication with the fourth oil port, and a second throttling hole is arranged on the oil passage 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 in communication with the third oil port, the second oil port is in communication with the fourth oil port, and a first throttling hole is arranged on the oil passage 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 with the fourth oil port, and the first oil port and the third oil port are not connected with other oil ports; the first oil port and the second oil port are connected with each other and connect the second oil pump through the third oil passage; the third oil port connects the clutch cooling part through the fourth oil passage; and the fourth oil port connects the motor cooling part through the fifth oil passage.

[0025] The above embodiment provides different levels of flow control through the multiple working positions of the cooling flow control valve to adapt to different cooling requirements; and the flow control of the oil is optimized through the design of the throttling holes, thereby reducing energy loss.

[0026] In an embodiment, the cooling flow control valve comprises a second valve core and a second spring, the second end face of the second valve core is connected with the second spring, and the hydraulic system further comprises a second control oil passage connecting the first end face of the second valve core of the cooling flow control valve and a clutch control subsystem, for transmitting a 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 moves against the action force of the second spring to control the switching of the cooling flow control valve between different working positions.

[0027] The above embodiment realizes flexible control of the cooling flow control valve through the configuration of the cooling flow control valve and the second control oil passage and the pressure transmitted through the second control oil passage. The system can quickly respond to different working states, thereby improving the cooling efficiency of the system.

[0028] According to a second aspect of the present application, a control method of a hydraulic system is provided, which is applied to the hydraulic system described in the above embodiment, and the method comprises:

[0029] When the instruction of the first working state is received, 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 passage, and the cooling subsystem performs driving motor cooling control.

[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 combination control, and the cooling subsystem performs clutch cooling control and driving 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 maintaining control, and the cooling subsystem performs clutch cooling control and driving motor cooling control.

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

[0033] The hydraulic system and the control method thereof provided by the above embodiment introduce independent control subsystems and cooling subsystems, which are specially used for the control and cooling of the hybrid power module, realize clutch control function, clutch cooling function and driving motor cooling function, realize clutch control function, clutch cooling function and driving motor cooling function without changing the hydraulic system of the base transmission, and have low cost and high generalization degree. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 The structural schematic diagram of the hydraulic system provided by an embodiment of the present application is shown in the figure.

[0036] Figure 2 The structural schematic diagram of the first embodiment of the clutch control valve provided by an embodiment of the present application is shown in the figure.

[0037] Figure 3 The structural schematic diagram of the cooling flow control valve provided by an embodiment of the present application is shown in the figure.

[0038] Figure 4 The structural schematic diagram of the second embodiment of the clutch control valve provided by an embodiment of the present application is shown in the figure.

[0039] Among them, the above drawings include the following reference signs:

[0040] 1, oil supply subsystem; 2, clutch control subsystem; 3, cooling subsystem; 4, one-way oil path; 5, one-way valve; 6, safety oil path; 7, safety valve; 8, first control oil path; 9, second control oil path;

[0041] 11, oil sump; 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 path; 211, first oil port; 212, second oil port; 213, third oil port; 214, fourth oil port; 215, first end surface of first valve core; 216, second end surface 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 path; 35, fourth oil path; 36, fifth oil path; 311, first oil port; 312, second oil port; 313, third oil port; 314, fourth oil port; 315, second end surface of second valve core; 316, first end surface of second valve core; 317, second spring; 318, first orifice; 319, second orifice. DETAILED DESCRIPTION

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

[0045] Similar reference numerals and letters represent similar items in the drawings below, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second", etc. are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0046] Figure 1 A structural schematic diagram of a hydraulic system provided by the embodiments of the present application is shown in FIG. 1, which includes an oil supply subsystem 1, a clutch control subsystem 2, a cooling subsystem 3, and a one-way oil path 4.

[0047] The oil supply subsystem 1 is configured to output hydraulic oil. In an embodiment, as shown in FIG. 1, the oil supply subsystem 1 includes an oil sump 11, a filter 12, an oil pump motor 13, a first oil pump 14, and a second oil pump 15. Figure 1As shown, the oil supply subsystem 1 comprises an oil sump 11, a filter 12, an oil pump motor 13, a first oil pump 14 and a second oil pump 15. The first oil pump 14 is connected to the clutch control subsystem 2 for supplying oil to the clutch control subsystem 2. The second oil pump 15 is connected to the cooling subsystem 3 for supplying 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 for powering the first oil pump 14 and the second oil pump 15. The oil sump 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 sump 11 is used for storing hydraulic oil, and the filter 12 is used for removing 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, i.e. the oil pump motor 13 simultaneously drives the first oil pump 14 and the second oil pump 15, 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 an embodiment, the clutch control subsystem 2 comprises 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 a first oil line 23, and is connected to the cooling subsystem 3 through the one-way oil line 4. The clutch control unit 22 is connected to the clutch control valve 21 through a second oil line 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 for clutch cooling control and drive motor cooling control. In an embodiment, the cooling subsystem 3 comprises 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 a third oil line 34. The one-way oil line 4 connects the clutch control subsystem 2 and the third oil line 34. The clutch cooling unit 32 is connected to the cooling flow control valve 31 through a fourth oil line 35 for receiving hydraulic oil for clutch cooling. The motor cooling unit 33 is connected to the cooling flow control valve 31 through a fifth oil line 36 for receiving hydraulic oil for drive 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 line 4 connects the clutch control subsystem 2 and the cooling subsystem 3 respectively, for transmitting hydraulic oil from the clutch control subsystem 2 to the cooling subsystem 3 when the clutch is not engaged. In an embodiment, a one-way valve 5 is also installed on the one-way oil line 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 comprises a safety oil path 6 connecting the clutch control subsystem 2 and the cooling subsystem 3, for transmitting the excess oil of the clutch control subsystem 2 to the cooling subsystem 3 during the clutch pressure maintaining stage.

[0053] In one embodiment, a safety valve 7 is further installed on the safety oil path 6, for ensuring that the system pressure does not exceed a set safety value, ensuring 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, as shown in Figure 1 and Figure 2 , the clutch control valve 21 has at least two working positions:

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

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

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

[0058] In one embodiment, as shown in Figure 1 , 2 , 4, the clutch control valve 21 comprises a first valve core, an electromagnet 217 and a first spring 218, the first end surface 215 (for example, the right end surface) of the first valve core is connected with the electromagnet 217, and the second end surface 216 (for example, the left end surface) of the first valve core is connected with the first spring 218. In one embodiment, the hydraulic system further comprises a first control oil path 8 connecting the second oil port 212 and the second end surface 216 of the first valve core, for realizing the pressure control of the clutch. Exemplarily, the second oil port 212 is connected with the second end surface 216 of the first valve core through the first control oil path 8, the electromagnetic force of the first end surface 215 of the first valve core and the hydraulic pressure of the second end surface 216 of the first valve core are balanced with each other, realizing the pressure control of the clutch.

[0059] In one embodiment, as shown in Figure 1 andFigure 3 As shown, the cooling flow control valve 31 has at least three operating positions:

[0060] Cooling flow control valve 31 in the first operating position ( Figure 3 (Left position in the middle), 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 orifice 319 is provided in the oil line between the first oil port 311 and the third oil port 313.

[0061] Cooling flow control valve 31 in the second operating position ( Figure 3 In the middle position), 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 orifice 318 is provided in the oil line between the second oil port 312 and the fourth oil port 314.

[0062] When the cooling flow control valve 31 is in the third operating position ( Figure 3 (Right position in the middle), 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 connected to the second oil pump 15 through the third oil passage 34; the third oil port 313 is connected to the clutch cooling unit 32 through the fourth oil passage 35; and the fourth oil port 314 is connected to the motor cooling unit 33 through the fifth oil passage 36.

[0064] In one embodiment, the cooling flow control valve includes a second valve core and a second spring 317, with a second end face 315 (e.g., the right end face) of the second valve core connected to the second spring 317. Further, the hydraulic system also includes a second control oil circuit 9, which connects to a first end face 316 (e.g., the left end face) of the second valve core of the cooling flow control valve 31 and a clutch control subsystem 2. This control circuit 9 transmits clutch control pressure to the first end face 316 of the second valve core of the cooling flow control valve 31, causing the second valve core to move against the force of the second spring 317, thereby controlling the switching of the cooling flow control valve 31 between different operating 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 the command for the first working state is received, 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. The cooling subsystem 3 performs cooling control of the drive motor.

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

[0068] The oil pumped by the first oil pump 14 flows to the motor cooling part 33 through the first oil path 23, the first oil port 211, the third oil port 213, the one-way oil path 4, the one-way valve 5, the third oil path 34, the second oil port 312, the fourth oil port 314, and the fifth oil path 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 for driving motor cooling. 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 system drag loss, improving vehicle energy utilization efficiency, and improving system response speed and cooling efficiency.

[0070] When receiving the second working state instruction, 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 driving motor cooling control.

[0071] Specifically, in the second working state, the vehicle is in the pure electric to hybrid conversion mode, i.e., the clutch changes from the disengaged state to the engaged state, and at this time, the clutch pressure needs to be accurately controlled to achieve clutch engagement control, clutch cooling, and driving motor cooling functions. At this time, a certain current is applied to the electromagnet 217, the clutch control valve 21 is in the second working position (right position in Figure 2 ), the clutch control pressure acts on the first end surface 316 of the second valve core through the second control oil path 9, causing the valve core to move against the force of the second spring 317, and the cooling flow control valve 31 is in the second working position (middle position in Figure 3 ).

[0072] The oil pumped by the first oil pump 14 enters the clutch control part 22 through the first oil path 23, the first oil port 211, the second oil port 212, and the second oil path 24, and the second oil port 212 is connected to the second end surface 216 of the first valve core through the first control oil path 8, the electromagnetic force of the first end surface 215 of the first valve core and the hydraulic pressure of the second end surface 216 of the first valve core are balanced with each other, and the pressure control of the clutch is realized. The oil pumped by the second oil pump 15 reaches the cooling flow control valve 31 through the third oil path 34, part of the oil reaches the clutch cooling part 32 through the first oil port 311, the third oil port 313, and the other part of the oil reaches the motor cooling part 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 arranged to increase the amount of hydraulic oil reaching the clutch cooling part 32.

[0073] The control method realizes the accurate control of the clutch from disengagement to engagement, ensures the stability and reliability of the clutch during the engagement process, and according to the cooling requirements of the clutch and the driving motor, the amount of hydraulic oil reaching the clutch cooling part 32 is increased by arranging the first throttle hole 318, while the small flow cooling of the motor cooling part 33 is maintained, and the optimal distribution of the cooling flow is realized.

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

[0075] Specifically, when the third working state is in the hybrid mode, the clutch needs to be pressure maintained, the clutch needs a fixed pressure and a small cooling flow, and the driving motor needs 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, and the clutch control valve 21 is in the second working position (right position in the figure). The clutch control pressure acts on the first end surface 316 of the second valve core through the second control oil path 9, so that the valve core further moves against the action force of the second spring 317, and the cooling flow control valve 31 is in the first working position (left position in the figure). Figure 2 Figure 3

[0076] ​​The oil pumped by the first oil pump 14 enters the clutch control part 22 through the first oil path 23, the first oil port 211, the second oil port 212, and the second oil path 24, at this time, the oil pumped by the first oil pump 14 only needs to supplement the leakage of the clutch control part 22, the excess oil reaches the cooling flow control valve 31 through the safety oil path 6, the safety valve 7, and the third oil path 34, part of the oil reaches the clutch cooling part 32 through the first oil port 311, the second throttle hole 319, the third oil port 313, and the fourth oil path 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 path 36.

[0077] The oil pumped by the second oil pump 15 reaches the cooling flow control valve 31 through the third oil path 34, part of the oil reaches the clutch cooling part 32 through the first oil port 311, the second throttle hole 319, the third oil port 313, and the fourth oil path 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 path 36, because the clutch generates little heat after complete engagement, the second throttle hole 319 is arranged to increase the amount of hydraulic oil reaching the motor cooling part 33.

[0078] The control method realizes long engagement and pressure maintaining control of the clutch, ensures the stability of power output, and through the arrangement of the second throttle hole 319, increases the amount of hydraulic oil reaching the motor cooling part 33, and at the same time reduces the leakage of the clutch control part 22, optimizes 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 first oil port 211 and the second oil port 212 are connected, and the third oil port 213 and the fourth oil port 214 are communicated when the clutch control valve 21 is in the second working position (right position in the figure). Figure 4 Due to the one-way valve 5 installed on the one-way oil path 4, it is ensured that the oil can only flow from the clutch control subsystem 2 to the cooling subsystem 3 in one direction, so even in the state that the third oil port 213 and the fourth oil port 214 are communicated, the effect of disconnecting the cooling subsystem 3 from the clutch control subsystem 2 can be achieved.

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

[0081] At present, for the transmission products that simultaneously consider internal combustion engine driving and hybrid power driving, a hybrid power module is added to the basic transmission structure, generally to realize the clutch control function, clutch cooling function, and driving motor cooling function in the hybrid power module, the original transmission hydraulic control system is changed, which leads to a decrease in the generalization rate of parts, an increase in product cost, and an increase in production investment.

[0082] The current hydraulic system cannot accurately control the cooling flow distribution of the hydraulic system under different working conditions when realizing hybrid driving, so that the flow demand of the clutch and the driving motor cooling cannot be met, or the system efficiency is reduced and the energy consumption of the system is increased due to excessive flow.

[0083] The hydraulic system and the control method thereof provided by the embodiment of the present application introduce independent control subsystem and cooling subsystem, which are specially used for the control and cooling of the hybrid power module, realize the clutch control function, the clutch cooling function and the driving motor cooling function, realize the clutch control function, the clutch cooling function and the driving motor cooling function without changing the basic transmission hydraulic system, and have low cost and high generalization degree.

[0084] The system connects the clutch control subsystem and the cooling subsystem through the one-way oil circuit, transmits the hydraulic oil of the clutch control subsystem to the cooling subsystem when the clutch is not combined, makes the clutch control subsystem and the cooling subsystem work cooperatively, provides different levels of flow control through multiple working positions of the clutch control valve and the cooling flow control valve, optimizes the flow control of the oil through the design of the throttle hole, can realize efficient and accurate control under different working conditions, optimizes the cooling flow distribution, reduces the energy consumption and loss, and improves the performance and driving experience of the vehicle.

[0085] The above is only an embodiment of the present application and does not limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydraulic system, characterized in that, include: Oil supply subsystem (1), which is used to output hydraulic oil; Clutch control subsystem (2), which is connected to oil supply subsystem (1), is used for clutch engagement control; Cooling subsystem (3), which is connected to oil supply subsystem (1), is used for clutch cooling control and drive motor cooling control; A one-way oil circuit (4) is connected to the clutch control subsystem (2) and the cooling subsystem (3) respectively, 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. The clutch control subsystem (2) includes a clutch control valve (21), which is connected to the first oil pump (14) of the oil supply subsystem (1) through the first oil circuit (23) and to the cooling subsystem (3) through the one-way oil circuit (4). The cooling subsystem (3) includes: Cooling flow control valve (31), which is connected to the second oil pump (15) of the oil supply subsystem (1) via a third oil circuit (34); the one-way oil circuit (4) connects the clutch control subsystem (2) and the third oil circuit (34); clutch cooling unit (32), which is connected to the cooling flow control valve (31) via a fourth oil circuit (35) for receiving hydraulic oil to cool the clutch; motor cooling unit (33), which is connected to the cooling flow control valve (31) via a fifth oil circuit (36) for receiving hydraulic oil to cool the drive motor; The cooling flow control valve (31) is used to regulate the amount of oil reaching the clutch cooling section (32) and the motor cooling section (33); The cooling flow control valve (31) has at least three operating 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 connected to the third oil port (313), the second oil port (312) is connected to the fourth oil port (314), and a second throttling orifice (319) is provided in the oil line 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 connected to the third oil port (313), the second oil port (312) is connected to the fourth oil port (314), and a first throttling orifice (318) is provided in the oil line 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) are not connected to other oil ports; The first oil port (311) is connected to the second oil port (312) and is connected to the second oil pump (15) through the third oil passage (34); the third oil port (313) is connected to the clutch cooling unit (32) through the fourth oil passage (35); the fourth oil port (314) is connected to the motor cooling unit (33) through the fifth oil passage (36).

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

3. The hydraulic system according to claim 1, characterized in that, The oil supply subsystem (1) includes: 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); Oil pump motor (13) is connected to the first oil pump (14) and the second oil pump (15) and is used to provide power to 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) includes: The clutch control unit (22) is connected to the clutch control valve (21) via a second oil passage (24). 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 operating 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) of the clutch control valve (21), and the second oil port (212) of the clutch control valve (21) is connected to the fourth oil port (214) of the clutch control valve (21). 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) of the clutch control valve (21), and the third oil port (213) of the clutch control valve (21) and the fourth oil port (214) of the clutch control valve (21) are not connected to other oil ports. The first oil pump (14) is connected to the first oil port (211) of the clutch control valve (21) through the first oil passage (23), and the clutch control unit (22) is connected to the second oil port (212) of the clutch control valve (21) through the second oil passage (24); the third oil port (213) of the clutch control valve (21) is connected to the cooling subsystem (3) through the one-way oil passage (4).

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

7. The hydraulic system according to claim 1, characterized in that, The cooling flow control valve includes a second valve core and a second spring (317), the second end face (315) of the second valve core being connected to the second spring (317), and the hydraulic system further includes: 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). It is used to transmit 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 moves against the force of the second spring (317) to control the cooling flow control valve (31) to switch between different working positions.

8. A control method for a hydraulic system, characterized in that, Applied to the hydraulic system according to any one of claims 1-7, the method comprises: When the instruction for the first working state is received, 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). The cooling subsystem (3) performs cooling control of the drive motor. When the command for the second working state is received, 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 the instruction for the third working state is received, 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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