Cooling system of automobile driving assembly, control method and automobile

Abstract

The invention relates to the technical field of vehicle control, and particularly provides a cooling system of an automobile driving assembly, a control method and an automobile. The cooling system comprises an oil cooler, an oil cooling circulation pipeline and a water cooling circulation pipeline, wherein the oil cooling circulation pipeline and the water cooling circulation pipeline exchange heat through the oil cooler. A circulating oil pump, a driving motor and a transmission are arranged on the oil cooling circulating pipeline; the circulating oil pump drives cooling oil to circulate so as to cool the driving motor and the transmission; a circulating water pump and a radiator are arranged on the water-cooling circulating pipeline, and the circulating water pump drives cooling water to circulate so as to reduce the temperature of cooling oil flowing through the oil cooler. According to the cooling system of the automobile driving assembly, the cooling mode that inner circulation and outer circulation are matched is adopted, cooling oil in oil cooling circulation is cooled through water cooling circulation, then the driving motor and the transmission are cooled through the oil cooling circulation, and therefore the cooling system has the good and stable cooling capacity; and the cooling performance of the cooling system on the automobile driving assembly can be improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a cooling system for an automotive drivetrain. Furthermore, this invention also relates to a control method and an automotive vehicle. Background Technology

[0002] With the rapid development of new energy technologies, especially the rapid progress and improvement of power battery technology, pure electric commercial vehicles are receiving increasing attention from major automakers.

[0003] Like the battery system, the drivetrain is also an important component of pure electric commercial vehicles. Many pure electric commercial vehicles use a single motor or dual motor central drive system for their drivetrains.

[0004] In a centrally driven drive assembly, the main components include a high-speed drive motor, a transmission, and a cooling system. The ambient temperature of the drive motor is a crucial factor determining its normal operation, and the transmission, in addition to requiring lubrication, also needs to have its operating temperature appropriately reduced. Therefore, the cooling system plays a vital role in effectively controlling the operating temperatures of the drive motor and the transmission.

[0005] In existing drive assemblies that use a drive motor as a primary power source, the cooling system typically includes both oil cooling and water cooling, forming two interconnected cooling cycles. The oil cooling cycle, also known as the internal circulation, controls the oil pump speed based on the oil temperature within the transmission and the drive motor's rotational speed / torque. The water cooling cycle, also known as the external circulation, is responsible for cooling the cooling oil and controls the duty cycle of the water pump and radiator fan based on the outlet water temperature and the drive motor temperature.

[0006] However, the speed and torque of the drive motor are basically transient changes, and steady-state conditions are relatively rare. Determining the oil pump speed solely based on the motor's speed / torque will inevitably cause instantaneous changes in the oil pump speed. Furthermore, the motor's temperature changes faster than the transmission oil temperature, and there are also situations where the transmission oil temperature is low but the drive motor temperature is high. In such cases, the inefficient operation of the water pump and fan will inevitably cause unnecessary loss of the vehicle's electrical energy. Summary of the Invention

[0007] In view of this, the present invention aims to provide a cooling system for an automotive drive assembly to improve the cooling performance of the automotive drive assembly.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0009] A cooling system for an automotive drive assembly includes an oil cooler, and an oil-cooled circulation pipeline and a water-cooled circulation pipeline for heat exchange through the oil cooler; a circulating oil pump, a drive motor, and a transmission are provided on the oil-cooled circulation pipeline, the circulating oil pump driving the circulation of cooling oil to cool the drive motor and the transmission; a circulating water pump and a radiator are provided on the water-cooled circulation pipeline, the circulating water pump driving the circulation of cooling water to reduce the temperature of the cooling oil flowing through the oil cooler.

[0010] Furthermore, the radiator is equipped with a cooling fan, which cools the cooling water flowing through the radiator in the form of air cooling.

[0011] Furthermore, a combined controller is installed on the water-cooled circulation pipeline on the outlet side of the circulating water pump. The combined controller is used to distribute the cooling water pumped out by the circulating water pump to the steering oil pump cooling unit, the brake air pump cooling unit, and the oil cooler.

[0012] Furthermore, the transmission is equipped with a first temperature sensor for detecting the transmission oil temperature, the drive motor is equipped with a second temperature sensor for detecting the motor stator temperature, and the water-cooled circulation pipe on the outlet side of the circulating water pump is equipped with a third temperature sensor for detecting the cooling water outlet temperature.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] The cooling system for the automotive drive assembly of the present invention adopts a cooling and temperature reduction method that combines internal and external circulation. The water cooling circulation cools the cooling oil in the oil cooling circulation, and the oil cooling circulation cools the drive motor and transmission. This gives the cooling system good and stable cooling capacity, which is beneficial to improving the cooling and temperature reduction performance of the automotive drive assembly.

[0015] Furthermore, by equipping the radiator with a cooling fan to cool the cooling water in the water-cooling circulation system using air cooling, the cooling performance of the water-cooling circulation system on the oil-cooling circulation system can be guaranteed. By installing a combined controller on the water-cooling circulation pipeline downstream of the circulating water pump, the cooling water pumped by the circulating water pump can be selectively distributed and regulated to accurately respond to the different cooling requirements of the steering oil pump cooling unit, brake air pump cooling unit, or oil cooler on the oil-cooling circulation pipeline.

[0016] Another object of the present invention is to provide a control method for controlling the cooling system of the aforementioned automotive drive assembly, the control method comprising:

[0017] The transmission oil temperature at the transmission, the stator temperature of the drive motor, and the outlet temperature of the cooling water on the water-cooled circulation pipeline are obtained.

[0018] Using the transmission oil temperature and the motor stator temperature as variables, the oil pump control parameters are calculated based on a preset first algorithm to control the operating speed of the circulating oil pump;

[0019] Using the transmission oil temperature and the cooling water outlet temperature as variables, water pump control parameters are calculated based on a preset second algorithm to control the operating speed of the circulating water pump.

[0020] Furthermore, the radiator is equipped with a cooling fan, and the control method further includes:

[0021] Using the transmission oil temperature and the coolant outlet temperature as variables, fan control parameters are calculated based on a preset third algorithm to control the operating speed of the cooling fan.

[0022] Furthermore, the circulating water pump is started first to cool the cooling water, and the cooling fan is controlled to run only when the calculated water pump control parameters exceed the load capacity of the circulating water pump.

[0023] Furthermore, the first algorithm, the second algorithm, and the third algorithm all employ a dynamic table lookup method.

[0024] Furthermore, in the first algorithm, a first oil pump parameter comparison table is preset, corresponding to the transmission oil temperature and the oil pump control parameters, and a second oil pump parameter comparison table is preset, corresponding to the motor stator temperature and the oil pump control parameters. The larger value is used among the oil pump control parameters obtained from the first and second oil pump parameter comparison tables. In the second algorithm, a first water pump parameter comparison table is preset, corresponding to the transmission oil temperature and the fan control parameters, and a second water pump parameter comparison table is preset, corresponding to the coolant outlet temperature and the fan control parameters. The larger value is used among the water pump control parameters obtained from the first and second water pump parameter comparison tables. In the third algorithm, a first fan parameter comparison table is preset, corresponding to the transmission oil temperature and the fan control parameters, and a second fan parameter comparison table is preset, corresponding to the coolant outlet temperature and the fan control parameters. The larger value is used among the fan control parameters obtained from the first and second fan parameter comparison tables.

[0025] The control method of the present invention has the technical advantages of the cooling system of the aforementioned automotive drive assembly; furthermore, by using transmission oil temperature and motor stator temperature as parameter variables to control the operating speed of the circulating oil pump, it overcomes the problem that controlling the operation of the circulating oil pump by using the speed and torque of the drive motor as variables can easily cause sudden changes in the operating speed of the circulating oil pump in the case where the speed of the drive motor is prone to sudden increases and decreases, but the temperature of the drive motor stator itself does not change much; this helps to keep the circulating oil pump in a more stable operating state, thereby improving the overall control and operation effect of the cooling system.

[0026] Meanwhile, using transmission oil temperature and coolant outlet temperature as parameters to control the operation of the circulating water pump overcomes the problem of a long control logic chain when using motor stator temperature as a variable to control the circulating water pump, which leads to a relatively slow control response of the circulating water pump. This has a good effect on improving the overall control and operation of the cooling system.

[0027] Another object of the present invention is to provide an automobile equipped with a cooling system for the automobile drive assembly described in the present invention, and a control unit;

[0028] The control unit includes a processor and a memory, the memory storing at least one computer program, which is loaded and executed by the processor to implement the control method as described in any one of claims 5 to 9.

[0029] The automobile of the present invention has the technical advantages of the cooling system and control method of the above-mentioned automobile drive assembly. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are for explaining the invention. The directional terms used, such as front / back, up / down, etc., are only used to indicate relative positional relationships and do not constitute an improper limitation of the invention. In the drawings:

[0031] Figure 1 This is a schematic diagram of the overall structure of the automotive drive assembly according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the system configuration of the cooling system of the automobile drive assembly according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the control flow of the control method for the cooling system of the automotive drive assembly according to an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the control effect curve of the cooling system of a conventional automotive drive system mentioned in the embodiments of the present invention;

[0035] Figure 5 This is a schematic diagram of the control effect curve of the cooling system control method described in an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 11. First motor; 12. Second motor;

[0038] 21. First reduction gear set; 22. Second reduction gear set; 3. Circulating oil pump;

[0039] 4. Transmission; 40. Lubrication pump; 41. First shift fork; 42. Second shift fork; 43. Third shift fork;

[0040] 5. Oil cooler; 50. Oil cooling circulation piping; 51. Water cooling circulation piping;

[0041] 6. Radiator; 61. First cooling fan; 62. Second cooling fan;

[0042] 70. Circulating water pump; 71. Combined controller; 8. Water storage device. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0044] In the description of this invention, it should be stated that if terms such as "upper," "lower," "left," "right," "front," "back," "inner," and "outer" appear, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0045] Furthermore, in the description of this invention, unless otherwise explicitly defined, the terms "installation," "connection," "linking," and "connector" should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances. The limiting terms such as "first," "second," "A," "B," "C," and "D" appearing in the description of this invention are merely for distinguishing similar features in different locations, attributions, or uses, in order to avoid ambiguity and confusion, and should not be construed as indicating or implying relative importance.

[0046] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] Example 1

[0048] This embodiment relates to a cooling system for an automotive drive assembly, which is beneficial for improving the cooling performance of the automotive drive assembly; an exemplary system configuration is as follows: Figure 1 and Figure 2 As shown.

[0049] Overall, the cooling system of this vehicle drivetrain includes an oil cooler 5, and an oil-cooled circulation pipe 50 and a water-cooled circulation pipe 51 through which heat exchange occurs. The oil-cooled circulation pipe 50 is equipped with a circulating oil pump 3, a drive motor, and a transmission 4; the circulating oil pump 3 drives the circulation of cooling oil to cool the drive motor and transmission 4. The water-cooled circulation pipe 51 is equipped with a circulating water pump 70 and a radiator 6; the circulating water pump 70 drives the circulation of cooling water to lower the temperature of the cooling oil flowing through the oil cooler 5.

[0050] It should be noted that, based on the overall design concept described above, the technical solution of this invention can adopt various different specific implementation structures, forms, or configuration sequences. For example, the aforementioned automotive drive assembly can adopt a single motor or a dual motor configuration. Figure 1 As shown, the vehicle drive system in this embodiment is a dual-motor central drive type, with the drive motors including a first motor 11 and a second motor 12 arranged in parallel. The first motor 11 outputs power to the transmission 4 through a first reduction gear set 21, and the second motor 12 outputs power to the transmission 4 through a second reduction gear set 22. The transmission 4 is equipped with a mechanical oil pump 40, which mainly serves a lubrication function; of course, the transmission 4 also needs to be equipped with shift forks. In this embodiment, the transmission 4 is specifically equipped with three shift forks: a first shift fork 41, a second shift fork 42, and a third shift fork 43, to jointly realize the vehicle's shifting function.

[0051] It should be noted that the aforementioned lubricating pump 40 and circulating oil pump 3 ( Figure 1 Unlike other lubricating oil pumps (not shown), the lubrication pump 40 is typically a mechanical oil pump that drives the circulation of lubricating oil to lubricate the transmission 4; the circulating oil pump 3 is typically an electronically driven oil pump that drives the circulation of cooling oil to cool the vehicle's drive assembly. Given that the drive motors are two motors arranged in parallel, the first motor 11 and the second motor 12 are also arranged in parallel in the oil cooling circulation pipe 50. The cooling oil in the oil cooling circulation pipe 50 cools the first motor 11 and the second motor 12 respectively. The motor stator temperature described below is obtained by simultaneously collecting the stator temperatures of the first motor 11 and the second motor 12, and using the higher value as the motor stator temperature.

[0052] For parts required for the overall implementation of the solution but not covered in the overall setup described above, reasonable and flexible designs can be made by referring to mature setup methods in the field and the actual situation during implementation. The specific implementation scheme described below in this embodiment is only one of the many solutions that can be formed by the various combinations and variations described above. In actual implementation, those skilled in the art can make flexible adjustments and improvements based on the actual situation. Obviously, the various solutions that can be formed by the combinations and variations of the above specific forms, as well as the specific implementation scheme of this embodiment, are all within the protection scope of this invention.

[0053] Specifically, in this embodiment, as Figure 2 As shown, in the water-cooled circulation pipeline 51, along the circulation direction of the cooling water, a radiator 6, a water storage device 8, a water-cooled control unit, and an oil cooler 5 are arranged in sequence. The water-cooled control unit includes a circulating water pump 70 and a combined controller 71 arranged in sequence. The water storage device 8 can be in the form of an overflow tank. While storing cooling water for the water-cooling system, when the water flow rate in the water-cooled circulation pipeline 51 is too high and exceeds the capacity of the radiator 6, the cooling water can flow back to the water storage device 8 through parallel branch lines, and then flow out from the water storage device 8 to participate in the cooling water circulation within the water-cooled circulation pipeline 51. This arrangement can improve the load-bearing capacity of the water circulation system.

[0054] Meanwhile, the radiator 6 in this embodiment is also equipped with a cooling fan, which can cool the cooling water flowing through the radiator 6 in the form of air cooling. By equipping the radiator 6 with a cooling fan to cool the cooling water in the water cooling cycle in the form of air cooling, the cooling performance of the water cooling cycle over the oil cooling cycle can be guaranteed. Specifically, in this embodiment, two cooling fans, a first cooling fan 61 and a second cooling fan 62, are arranged side by side on the side of the radiator 6; the two cooling fans can operate synchronously and in parallel to cool the radiator 6, thereby cooling the temperature of the cooling water flowing through the radiator 6.

[0055] As mentioned above, a combined controller 71 is installed on the water-cooled circulation pipe 51 on the outlet side of the circulating water pump 70. The combined controller 71 is used to distribute the cooling water pumped by the circulating water pump 70 to the steering oil pump cooling unit, the brake air pump cooling unit, and the oil cooler 5. By installing the combined controller 71 on the water-cooled circulation pipe 51 downstream of the circulating water pump 70, the cooling water pumped by the circulating water pump 70 can be selectively distributed and regulated by the combined controller 71 to accurately respond to the different cooling requirements of the steering oil pump cooling unit, the brake air pump cooling unit, or the oil cooler 5 on the oil-cooled circulation pipe 50.

[0056] Based on the above configuration, the transmission 4 in this embodiment is equipped with a first temperature sensor for detecting the transmission oil temperature, and the drive motor is equipped with a second temperature sensor for detecting the motor stator temperature (when there are two drive motors arranged in parallel, each motor is equipped with a second temperature sensor). A third temperature sensor is installed on the water-cooled circulation pipe 51 on the outlet side of the circulating water pump 70 to detect the cooling water outlet temperature. By installing temperature sensors on the transmission 4, drive motor, and water-cooled circulation pipe 51, the oil and water temperatures at each key location can be collected in real time, providing accurate variable conditions for the control of the circulating oil pump 3, circulating water pump 70, and cooling fan.

[0057] In summary, the cooling system of the vehicle drive assembly in this embodiment adopts a cooling and temperature reduction method that combines internal and external circulation. The water cooling circulation cools the cooling oil in the oil cooling circulation, and the oil cooling circulation cools the drive motor and transmission 4. This gives the cooling system a good and stable cooling capacity, which is beneficial to improving the cooling and temperature reduction performance of the vehicle drive assembly.

[0058] Example 2

[0059] This embodiment relates to a control method for controlling the cooling system of the automotive drive assembly provided in Embodiment 1; an exemplary control flow is as follows: Figure 3 As shown.

[0060] Overall, the control method includes the following steps:

[0061] S1. Obtain the transmission oil temperature at the transmission 4, the motor stator temperature of the drive motor, and the cooling water outlet temperature on the water-cooled circulation pipe 51.

[0062] S2. Using the transmission oil temperature and the motor stator temperature as variables, calculate the oil pump control parameters based on the preset first algorithm to control the operating speed of the circulating oil pump 3;

[0063] S3. Using the transmission oil temperature and coolant outlet temperature as variables, calculate the water pump control parameters based on the preset second algorithm to control the operating speed of the circulating water pump 70.

[0064] The control method of this embodiment has the technical advantages of the cooling system of the aforementioned automotive drive assembly; furthermore, by using transmission oil temperature and motor stator temperature as parameter variables to control the operating speed of the circulating oil pump 3, it overcomes the problem that controlling the operation of the circulating oil pump 3 by using the speed and torque of the drive motor as variables can easily cause sudden changes in the operating speed of the circulating oil pump 3 in the case where the speed of the drive motor is prone to sudden increases and decreases, but the stator temperature of the drive motor itself does not change much; this helps to keep the circulating oil pump 3 in a relatively stable operating state, thereby improving the overall control and operation effect of the cooling system.

[0065] Specifically, in this embodiment, the heat sink 6 is equipped with a cooling fan; correspondingly, the control method in this embodiment further includes the following step S4:

[0066] S4. Using transmission oil temperature and coolant outlet temperature as variables, calculate fan control parameters based on a preset third algorithm to control the operating speed of the cooling fan.

[0067] Similarly, the operating speed of the cooling fan is controlled by using the transmission oil temperature and the coolant outlet temperature as variables. The cooling fan and the circulating water pump 70 work together to respond in real time, thereby reducing the cooling water in the water-cooled circulation pipe 51 to a reasonable temperature range, providing a reliable guarantee for the stability of the water-cooled circulation performance.

[0068] When step S4 is included, it is preferable to include a decision logic between steps S3 and S4. Specifically, for example... Figure 3 As shown, the circulating water pump 70 should be started first to cool the cooling water. Only when the calculated pump control parameters exceed the load capacity of the circulating water pump 70 should the cooling fan be controlled based on the calculated fan control parameters; otherwise, only the circulating water pump 70 should be started to achieve the cooling effect. In water cooling circulation, prioritizing the start of the lower-power circulating water pump 70 increases the circulation speed of the cooling water, thereby using the radiator 6 to cool the cooling water, which helps to reduce the overall energy consumption of the cooling system.

[0069] Of course, there are multiple options for the preset algorithms mentioned above; for example, an interpolation iterative PID control algorithm can be used to calculate the control parameter values ​​that should be output based on the input variables according to the preset PID control parameters.

[0070] However, preferably, in this embodiment, the first algorithm, the second algorithm, and the third algorithm all employ a dynamic lookup table method. The dynamic lookup table method calculates the required control parameters using the obtained variables, offering advantages such as simple algorithms, short calculation time, clear control logic, and fast control response speed.

[0071] Specifically, in the first algorithm, there is a first oil pump parameter comparison table that compares the transmission oil temperature and the oil pump control parameters, and a second oil pump parameter comparison table that compares the motor stator temperature and the oil pump control parameters. The larger value is selected from the oil pump control parameters obtained from the first oil pump parameter comparison table and the second oil pump parameter comparison table.

[0072] Similarly, in the second algorithm, a first water pump parameter comparison table is preset, which compares the transmission oil temperature and fan control parameters, and a second water pump parameter comparison table is preset, which compares the coolant outlet temperature and fan control parameters. The larger value is used among the water pump control parameters obtained from the first and second water pump parameter comparison tables. In the third algorithm, a first fan parameter comparison table is preset, which compares the transmission oil temperature and fan control parameters, and a second fan parameter comparison table is preset, which compares the coolant outlet temperature and fan control parameters. The larger value is used among the fan control parameters obtained from the first and second fan parameter comparison tables.

[0073] In each algorithm, based on the case where two different variables are used to calculate the control parameters, the control parameter value with the larger value among the two calculated control parameters is used as the actual control value to control the operation of the circulating oil pump 3, the circulating water pump 70, or the cooling fan. This ensures that the cooling system has sufficient cooling performance, thereby guaranteeing the cooling effect on the drive motor and transmission 4 in the cooling system.

[0074] Based on the overall setup described above, combined with Figure 4 , Figure 5 As shown, taking the operation of a pure electric commercial vehicle in a semi-trailer tractor (CHTC-TT) mode as an example, the control effect of the existing automotive drive system cooling system and the control effect of the cooling system control method described in this embodiment can be compared.

[0075] In the existing control strategy, based on the current architecture of the vehicle thermal management system, the specific control strategy is as follows: The output duty cycle of the circulating oil pump 3 is calculated based on the values ​​obtained from a table for the transmission oil temperature and the drive motor speed / torque, ultimately determining the operating speed of the circulating oil pump 3. The higher the transmission temperature or the greater the motor speed / torque, the higher the speed of the electronic oil pump. Simultaneously, the duty cycles of the circulating water pump 70 and the cooling fan are controlled based on the values ​​obtained from a table for the coolant outlet temperature and the motor stator temperature, ultimately determining the speeds of the circulating water pump 70 and the cooling fan. The higher the coolant outlet temperature and the motor stator temperature, the larger the duty cycle of the circulating water pump 70 and the cooling fan, meaning the higher their operating speeds.

[0076] Figure 4The diagram shows the variation curves of each variable and control parameter in the aforementioned existing control strategy. Among them, Figure 4 curves in Figure I The curves showing the vehicle speed change (S1), motor speed change (S2), and motor torque change (S3) are displayed. Figure 4 curves in Figure II The following curves are shown: motor temperature change curve T1, transmission oil temperature change curve T2, and coolant temperature change curve T3. Figure 4 curves in Figure III The following curves are shown: oil pump speed change curve P1, water pump operation curve P2, and cooling fan operation curve P3.

[0077] It can be seen that under normal vehicle operating conditions, the speed and torque of the drive motor are basically transient changes, with relatively few steady-state conditions. Therefore, the motor output (or reclaimed) power is a transient physical quantity. The temperature rise of the motor stator is due to the accumulation of heat that cannot be dissipated over time, which is related to the motor speed / torque, transmission oil temperature, and the speed of the circulating oil pump 3. However, determining the speed of the circulating oil pump 3 solely based on the motor speed / torque will inevitably cause sudden increases or decreases in the speed of the circulating oil pump 3, at which point the motor temperature may not necessarily be high. As... Figure 4 curves in Figure III As shown, the oil pump speed variation curve P1 contains multiple abrupt changes in oil pump speed Pv, indicating that the circulating oil pump 3 experiences several ineffective abrupt operational states, leading to increased energy consumption of the entire vehicle. Furthermore, transient speed changes also have a significant adverse impact on the durability of the circulating oil pump 3.

[0078] Still Figure 4 As shown, the duty cycle of the circulating water pump 70 and the cooling fan is controlled based on the temperature of the motor stator. Since the motor temperature changes faster than the transmission oil temperature, there are situations where the transmission oil temperature is relatively low but the motor stator temperature is high. In this case, the circulating water pump 70 and the cooling fan need to run at higher speeds, or even full speed. However, this does not significantly affect the cooling effect on the drive motor and transmission 4. The inefficient operation of the circulating water pump 70 and the cooling fan in this situation inevitably leads to unnecessary energy loss in the vehicle. Actual test results are as follows... Figure 4 curves in Figure III As shown, the circulating oil pump 3 frequently starts and stops, and its speed has strong sudden increases or decreases (as shown in Pv); the circulating water pump 70 and the cooling fan are continuously turned on for about 400s and 80s respectively, which not only have long running time, but also have no obvious cooling effect.

[0079] When the control method of this invention is adopted, the CHTC-TT cycle condition is still selected for comparative verification. Without affecting the motor temperature control effect, the resulting curves of the changes in various variables and control parameters are as follows: Figure 5 As shown. Among them, Figure 5 curves in Figure I The curves showing the vehicle speed change (S1), motor speed change (S2), and motor torque change (S3) are displayed. Figure 5 curves in Figure II The following curves are shown: motor temperature change curve T1, transmission oil temperature change curve T2, and coolant temperature change curve T3. Figure 5 curves in Figure III The following curves are shown: oil pump speed change curve P1, water pump operation curve P2, and cooling fan operation curve P3.

[0080] It can be seen that the frequency of frequent on / off switching of circulating oil pump 3 has been significantly reduced, and the speed change is smooth with no sudden increases / decreases in speed. Simultaneously, the continuous on-time of circulating water pump 70 has also been significantly reduced to approximately 110 seconds; the cooling fan is essentially not running. Based on the bus voltage and current of circulating oil pump 3, the energy consumption of circulating oil pump 3 is evaluated. After optimization, circulating oil pump 3 consumes approximately 0.05 kWh, saving 16.6% energy compared to 0.06 kWh before optimization. Similarly, based on the low-voltage side bus voltage and current of circulating water pump 70 and the cooling fan, the energy consumption of low-voltage cooling components (circulating water pump 70 and cooling fan) is evaluated. After optimization, the consumption is 0.15 kWh, saving 46.4% energy compared to 0.28 kWh before optimization.

[0081] It is evident that the optimized control strategy of this invention not only prevents sudden increases or decreases in the rotational speed of the circulating oil pump 3, but also reduces the adverse effects of inefficient operation of the circulating oil pump 3 on its durability. The optimized control strategies related to the circulating water pump 70 and the cooling fan improve the cooling effect of the circulating water pump 70 and the cooling fan, avoiding unnecessary energy loss to the vehicle's electrical system due to their inefficient operation. Therefore, using transmission oil temperature and motor stator temperature as parameters to control the operating speed of the circulating oil pump 3 overcomes the problem of sudden changes in the operating speed of the circulating oil pump 3 caused by using the rotational speed and torque of the drive motor as variables in situations where the drive motor's rotational speed is prone to sudden increases or decreases, but the stator temperature of the drive motor itself does not change significantly. This helps maintain a relatively stable operating state for the circulating oil pump 3, thereby improving the overall control and operation effect of the cooling system.

[0082] Example 3

[0083] This embodiment relates to a car equipped with a cooling system for the car drive assembly provided in Embodiment 1, and a control unit; and the control unit includes a processor and a memory, wherein the memory stores at least one computer program, which is loaded and executed by the processor to implement the control method provided in Embodiment 2.

[0084] In the cooling system of the vehicle drive assembly, a cooling method combining internal and external circulation is adopted. The water cooling circulation cools the cooling oil in the oil cooling circulation, and then the oil cooling circulation cools the drive motor and transmission 4. This gives the cooling system good and stable cooling capacity, which is beneficial to improving the cooling performance of the vehicle drive assembly.

[0085] Moreover, by using transmission oil temperature and motor stator temperature as parameters to control the operating speed of the circulating oil pump 3, the problem of sudden changes in the operating speed of the circulating oil pump 3 is overcome in situations where the speed of the drive motor is prone to sudden increases and decreases, but the stator temperature of the drive motor itself does not change much. This helps to keep the circulating oil pump 3 in a more stable operating state, thereby improving the overall control and operation effect of the cooling system.

[0086] The above description is merely a preferred embodiment of the present invention. Detailed explanations of configurations, examples of specific structural arrangements, and descriptions of assembly and connection methods are provided to ensure sufficient disclosure so that those skilled in the art can better implement the present invention, and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cooling system of an automobile drive assembly, characterized in that: an oil cooler (5) is included, and an oil cooling circulation pipeline (50) and a water cooling circulation pipeline (51) that exchange heat through the oil cooler (5) are included; a circulating oil pump (3) that drives cooling oil circulation to cool a drive motor and a transmission (4) is arranged on the oil cooling circulation pipeline (50); the circulating water pump (70) drives cooling water circulation to reduce the temperature of the cooling oil flowing through the oil cooler (5). 2.The cooling system of the automobile drive assembly according to claim 1, characterized in that: the radiator (6) is provided with a radiator fan that cools the cooling water flowing through the radiator (6) in the form of air cooling. 3.The cooling system of the automobile drive assembly according to claim 1, characterized in that: a combined controller (71) is arranged on the water cooling circulation pipeline (51) on the outlet side of the circulating water pump (70), and the combined controller (71) is used to distribute the cooling water pumped out by the circulating water pump (70) to a steering oil pump cooling unit, a brake air pump cooling unit, and the oil cooler (5). 4.The cooling system of the automobile drive assembly according to any one of claims 1 to 3, characterized in that: a first temperature sensor for detecting the temperature of transmission oil is arranged on the transmission (4), a second temperature sensor for detecting the temperature of a motor stator is arranged on the drive motor, and a third temperature sensor for detecting the outlet temperature of cooling water is arranged on the water cooling circulation pipeline (51) on the outlet side of the circulating water pump (70). including: obtaining the temperature of transmission oil of cooling oil at the transmission (4), the temperature of a motor stator of the drive motor, and the outlet temperature of cooling water on the water cooling circulation pipeline (51); taking the temperature of transmission oil and the temperature of a motor stator as variables, calculating an oil pump control parameter based on a preset first algorithm to control the operating speed of the circulating oil pump (3); taking the temperature of transmission oil and the outlet temperature of cooling water as variables, calculating a water pump control parameter based on a preset second algorithm to control the operating speed of the circulating water pump (70). 6.The control method according to claim 5, characterized in that: the radiator (6) is provided with a radiator fan, and the control method further includes: taking the temperature of transmission oil and the outlet temperature of cooling water as variables, calculating a fan control parameter based on a preset third algorithm to control the operating speed of the radiator fan. 7.The control method according to claim 6, characterized in that: the circulating water pump (70) is preferentially started to cool the cooling water, and only when the calculated water pump control parameter exceeds the load capacity of the circulating water pump (70), the radiator fan is controlled to operate based on the calculated fan control parameter. 8.The control method according to claim 6 or 7, characterized in that:

5. The control method of the cooling system of the automobile drive assembly according to any one of claims 1 to 4, characterized in that, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The first algorithm, the second algorithm and the third algorithm all adopt a dynamic look-up table method.

9. The control method according to claim 8, characterized in that: In the first algorithm, a first oil pump parameter look-up table of the transmission oil temperature and the oil pump control parameter, and a second oil pump parameter look-up table of the motor stator temperature and the oil pump control parameter are preset, and a larger value is used in the oil pump control parameter obtained through the first oil pump parameter look-up table and the second oil pump parameter look-up table respectively; In the second algorithm, a first water pump parameter look-up table of the transmission oil temperature and the fan control parameter, and a second water pump parameter look-up table of the cooling water outlet temperature and the fan control parameter are preset, and a larger value is used in the water pump control parameter obtained through the first water pump parameter look-up table and the second water pump parameter look-up table respectively; In the third algorithm, a first fan parameter look-up table of the transmission oil temperature and the fan control parameter, and a second fan parameter look-up table of the cooling water outlet temperature and the fan control parameter are preset, and a larger value is used in the fan control parameter obtained through the first fan parameter look-up table and the second fan parameter look-up table respectively.

10. An automobile, characterized in that: The automobile is provided with the cooling system of the automobile drive assembly according to any one of claims 1 to 4, and a control unit; The control unit comprises a processor and a memory, and at least one computer program is stored in the memory, the computer program is loaded and executed by the processor to realize the control method according to any one of claims 5 to 9.

Images