Lubricating and cooling device of electric vehicle power assembly and control method

Abstract

The invention discloses a lubricating and cooling device of an electric vehicle power assembly and a control method. The lubricating and cooling device comprises a sensor, a hydraulic device and an electronic control unit. A temperature sensor and a flow sensor are arranged on a lubricating point and a cooling point of the power assembly; the hydraulic device comprises an oil tank, a coarse filter, an electronic oil pump, a fine filter, a radiator and an electromagnetic valve; the electronic oil pump, the electromagnetic valve, the temperature sensor and the flow sensor are respectively connected with the electronic control unit; the structure is simple, and different lubricating and cooling requirements of different lubricating and cooling points can be effectively met at the same time; and the required lubricating and cooling flow under various working conditions is detected and compensated in real time, the lubricating and cooling reliability of the power assembly of the electric vehicle is improved, and the performance of the electric vehicle is improved.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle technology, and specifically relates to a lubrication and cooling device and a control method for an electric vehicle powertrain Background Art

[0002] The electric drive assembly consists of a motor, a motor controller, and a reducer. The motor and motor controller need to be cooled, and the reducer needs to be cooled and lubricated. Good cooling and lubrication are the basic prerequisites for ensuring the performance of the electric drive system. However, the three have different requirements for coolant temperature. For example, the motor and controller are generally water-cooled, and the temperature is generally between 30-75°C; the reducer is lubricated and cooled by oil, and the temperature is generally between 90-120°C. If multiple independent cooling systems are used, the system cooling efficiency is low, the cost is high, and it is not conducive to integrated design.

[0003] Therefore, how to design an integrated oil cooling system for the whole machine to meet the cooling and lubrication requirements of various components with different operating temperatures using the same cooling medium, and at the same time achieve the highest economic efficiency of the system under different working conditions through control algorithms, is the key technology for achieving highly integrated and high torque density design of electric drive assemblies. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a lubrication and cooling device and control method for an electric vehicle powertrain with a simple structure and high reliability. By timely mixing two types of hydraulic oil - cooled hydraulic oil and non-cooled hydraulic oil - to change the temperature (viscosity) of the hydraulic oil, the different operating temperature requirements of the motor, controller, reducer, etc. for the same hydraulic oil can be met.

[0005] The technical solution of the present invention to solve the above technical problems is:

[0006] A lubrication and cooling control method for an electric vehicle powertrain is implemented by using a lubrication and cooling device for the electric vehicle powertrain. The lubrication and cooling device for the electric vehicle powertrain includes a temperature sensor I, a temperature sensor II, a temperature sensor III, a flow sensor I, a flow sensor II, a flow sensor III, a hydraulic device and an electronic control unit; the hydraulic device includes an oil tank, a coarse filter, an electronic oil pump, a fine filter, a radiator, a solenoid valve I, a solenoid valve II, and a solenoid valve III; the oil tank is connected to the coarse filter, the electronic oil pump, and the fine filter in sequence to form a hydraulic oil branch AA, and after continuing to connect the radiator, hydraulic oil branches BB, CC, and DD are established respectively. The hydraulic oil temperature at these three locations is lower than that of the hydraulic oil branch AA because it has been cooled by the radiator. After the hydraulic oil branch DD is connected to the solenoid valve Ⅰ, it mainly forms the hydraulic oil branch EE. After the hydraulic oil branch BB is connected to the solenoid valve Ⅲ, it mainly forms the hydraulic oil branch GG. After the hydraulic oil branch AA is connected to the solenoid valve Ⅱ, it mainly forms the hydraulic oil branch FF. The hydraulic oil branch DD is connected to the A1 port of the solenoid valve Ⅰ, the A3 port of the solenoid valve Ⅰ is connected to the hydraulic oil branch EE, the hydraulic oil branch EE is connected to the first cooling point, and the A4 port of the solenoid valve Ⅰ is also connected to the hydraulic oil branch EE through the hydraulic pipeline. The hydraulic oil branch AA is connected to the B1 port of the solenoid valve Ⅱ, the hydraulic oil branch CC is connected to the B2 port of the solenoid valve Ⅱ, the B3 port of the solenoid valve Ⅱ is connected to the hydraulic oil branch FF, and the hydraulic oil branch FF is connected to the B4 port of the solenoid valve Ⅱ, the C2 port of the solenoid valve Ⅲ, the A2 port of the solenoid valve Ⅰ, and the first lubrication point in sequence through the hydraulic pipeline; the hydraulic oil branch BB is connected to the C1 port of the solenoid valve Ⅲ, the The C3 port of the solenoid valve III is connected to the hydraulic oil branch GG, the C4 port of the solenoid valve III is connected to the hydraulic oil branch GG through a hydraulic pipeline, and the hydraulic oil branch GG is connected to the second lubrication point; the first cooling point is sequentially installed with a temperature sensor I and a flow sensor I, which are respectively used to record the temperature of the first cooling point and the flow of hydraulic oil flowing therein, the first lubrication point is sequentially installed with a temperature sensor II and a flow sensor II, which are respectively used to record the temperature of the first lubrication point and the flow of hydraulic oil flowing therein, the second lubrication point is sequentially installed with a temperature sensor III and a flow sensor III, which are respectively used to record the temperature of the second lubrication point and the flow of hydraulic oil flowing therein; the electronic oil pump, solenoid valve I, solenoid valve II, solenoid valve III, temperature sensor I, temperature sensor II, temperature sensor III, flow sensor I, flow sensor II, and flow sensor III are respectively connected to the electronic control unit.

[0007] A lubrication and cooling control method for an electric vehicle powertrain, characterized in that the control method comprises the following specific steps:

[0008] 1) respectively detecting the temperature T1 of the first cooling point and the hydraulic oil flow rate q1 flowing therein, the temperature T2 of the first lubrication point and the hydraulic oil flow rate q2 flowing therein, and the temperature T3 of the second lubrication point and the hydraulic oil flow rate q3 flowing therein; the first cooling point, the first lubrication point, and the second lubrication point are all set with two target temperature ranges, namely T1 and T2;

[0009] 2) Based on the target temperature and target flow setting of the first cooling point, the first lubrication point, and the second lubrication point by the electronic control unit, the three solenoid valves are controlled to be in corresponding states respectively. The specific working details of each state are as follows:

[0010] A. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T1 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, no potential, and no potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve I in turn and flows into hydraulic oil branch EE. The hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve II in turn and flows into hydraulic oil branch FF. The hydraulic oil of hydraulic oil branch FF finally flows into the first lubrication point; the hydraulic oil of hydraulic oil branch BB passes through the C1 and C3 ports of solenoid valve III in turn and flows into hydraulic oil branch GG. The hydraulic oil of hydraulic oil branch GG finally flows into the second lubrication point;

[0011] B. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T2 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, no potential, and potential respectively. At this time, the hydraulic oil of the hydraulic oil branch DD passes through the A1 and A3 ports of the solenoid valve I in turn, and flows into the hydraulic oil branch EE, and the hydraulic oil of the hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of the hydraulic oil branch AA passes through the B1 and B3 ports of the solenoid valve II in turn, and flows into the hydraulic oil branch FF, and the hydraulic oil of the hydraulic oil branch FF finally flows into the first lubrication point; the hydraulic oil of the hydraulic oil branch BB passes through the C1 and C3 ports of the solenoid valve III in turn, and flows into the hydraulic oil branch GG, and at the same time, part of the hydraulic oil flowing out of the B3 port of the solenoid valve II also passes through the C2 and C4 ports of the solenoid valve III in turn and flows into the hydraulic oil branch GG. At this time, the temperature of the hydraulic oil on the hydraulic oil branch GG will rise, and the viscosity of the hydraulic oil here will also change accordingly, because two kinds of hydraulic oil are mixed—cooled hydraulic oil and non-cooled hydraulic oil. The hydraulic oils flowing into the hydraulic oil branch GG from two paths are combined and flow into the second lubrication point;

[0012] C. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T1 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, potential, and no potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve I in sequence and flows into the hydraulic oil branch EE. The hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve II in sequence and flows into the hydraulic oil branch FF. At the same time, the hydraulic oil of hydraulic oil branch CC passes through the B2 and B4 ports of solenoid valve II in sequence and flows into the hydraulic oil branch FF. At this time, the temperature of the hydraulic oil on the hydraulic oil branch FF will drop, and the viscosity of the hydraulic oil here will also change accordingly, because two kinds of hydraulic oil are mixed—cooled hydraulic oil and non-cooled hydraulic oil. The hydraulic oils flowing into the hydraulic oil branch FF from two paths are combined and flow into the first lubrication point together; the hydraulic oil of the hydraulic oil branch BB flows into the hydraulic oil branch GG through the C1 and C3 ports of the solenoid valve III in turn, and the hydraulic oil of the hydraulic oil branch GG finally flows into the second lubrication point;

[0013] D. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T2 respectively, solenoid valve Ⅰ, solenoid valve Ⅱ, and solenoid valve Ⅲ are in the states of no potential, potential, and potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve Ⅰ in turn, and flows into the hydraulic oil branch EE. The hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve Ⅱ in turn, and flows into the hydraulic oil branch FF. At the same time, the hydraulic oil of hydraulic oil branch CC passes through the B2 and B4 ports of solenoid valve Ⅱ in turn, and flows into the hydraulic oil branch FF. At this time, the temperature of the hydraulic oil on the hydraulic oil branch FF will drop, and the viscosity of the hydraulic oil here will also change accordingly, because two kinds of hydraulic oil are mixed—cooled hydraulic oil and non-cooled hydraulic oil. The hydraulic oils flowing into the hydraulic oil branch FF from two paths are combined and flow into the first lubrication point together; the hydraulic oils in the hydraulic oil branch BB flow into the hydraulic oil branch GG through the C1 and C3 ports of the solenoid valve III in sequence, and the part of the hydraulic oils flowing into the hydraulic oil branch FF from two paths that were combined and flowed into the hydraulic oil branch GG from two paths also flow into the hydraulic oil branch GG through the C2 and C4 ports of the solenoid valve III in sequence, and the hydraulic oils flowing into the hydraulic oil branch GG from two paths finally flow into the second lubrication point;

[0014] E. When the target temperature ranges of T1, T2, and T3 are T2, T1, and T1 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of gaining potential, gaining potential, and not gaining potential respectively, and the hydraulic oil of hydraulic oil branch AA flows into hydraulic oil branch FF through ports B1 and B3 of solenoid valve II in sequence, and at the same time, the hydraulic oil of hydraulic oil branch CC flows into hydraulic oil branch FF through ports B2 and B4 of solenoid valve II in sequence, and the hydraulic oil of the two branches flowing into hydraulic oil branch FF flows into the first lubrication port together; Part of the hydraulic oil that flows into the hydraulic oil branch FF through the two channels also flows into the hydraulic oil branch EE through the A2 port and A4 port of the solenoid valve I in turn; the hydraulic oil of the hydraulic oil branch DD flows into the hydraulic oil branch EE through the A1 port and A3 port of the solenoid valve I in turn, and the hydraulic oil that flows into the hydraulic oil branch EE through the two channels finally flows into the first cooling port; the hydraulic oil of the hydraulic oil branch BB flows into the hydraulic oil branch GG through the C1 port and C3 port of the solenoid valve III in turn, and the hydraulic oil of the hydraulic oil branch GG finally flows into the second lubrication port;

[0015] 3) Based on the information monitored in real time by the electronic control unit, the target required flow rate q of the first cooling point, the first lubrication point, and the second lubrication point is calculated respectively. x1 ,q x2 ,q x3 :

[0016]

[0017] Where: P t --efficiency loss, unit Kw; C--lubricating oil specific heat, unit kJ / (kg·k); p--lubricating oil density, unit kg / m 3 ; Δt=TT m --Temperature difference, unit: °C; q x -- Target required flow, unit L / min; η--lubrication coefficient; T--actual detection temperature, unit ℃; T m --Standard temperature, unit: °C;

[0018] 4) When the actual flow rate q1, q2, q3 of each point is detected, or none of them meets the respective target flow rate q x1 ,q x2 ,q x3 When the electronic control unit drives the electronic oil pump to accelerate, the actual flow rate q1, q2, q3 at each point meets the target flow rate q x1 ,q x2 ,q x3 ; If satisfied, the electronic oil pump is controlled to move at a constant speed.

[0019] In the lubrication and cooling control method of the electric vehicle powertrain, the temperature range of T1 is (0, 75] ° C, and the temperature range of T2 is (75, 100] ° C; when the target temperature of each point is in the range of T1, the standard temperature T used to calculate the target required flow rate at the first cooling point, the first lubrication point, and the second lubrication point is respectively 1m , T 2m , T 3m is: 100xR1℃, 104xR1℃, 106xR1℃, the demand coefficient R1 is 0.5; when the target temperature of each point is in the range of T2, the standard temperature T used to calculate the target demand flow rate in the first cooling point, the first lubrication point, and the second lubrication point is 1m , T 2m , T 3m The demand coefficient R2 is: 110x R2℃, 112xR2℃, 113x R2℃, and the demand coefficient R2 is 0.55.

[0020] In the lubrication and cooling control method of the electric vehicle powertrain, when the actual temperatures of T1, T2, and T3 are respectively within the temperature ranges of T2, T2, and T2, η is 1.25; otherwise, η is 1.1;

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The hydraulic circuit of the lubrication and cooling device of the electric vehicle powertrain of the present invention is simple in device and uses a single type of hydraulic oil. Through the automatic power-on / power-off operation of the solenoid valve, the hydraulic oils of different temperatures—cooled hydraulic oil and non-cooled hydraulic oil—can be mixed in time to adjust the temperature (viscosity) of the hydraulic oil, and at the same time meet the different requirements of the motor, controller, reducer, etc. in the electric vehicle powertrain for the temperature of the lubrication and cooling oil;

[0023] 2. The lubrication and cooling control method of the electric vehicle powertrain of the present invention detects and compensates the lubrication and cooling demand flow under different working conditions in real time based on the detection information of each sensor, thereby improving the reliability of lubrication and cooling of the electric vehicle powertrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a hydraulic principle diagram of the lubrication and cooling device of the electric vehicle powertrain of the present invention;

[0025] Figure 2 The present invention is a flow chart of a lubrication and cooling control method for an electric vehicle powertrain.

[0026] Figure 1Middle: 1. Oil tank, 2. Coarse filter, 3. Electronic oil pump, 4. Fine filter, 5. Radiator, 6. Solenoid valve I, 7. Temperature sensor I, 8. First cooling point, 9. Flow sensor I, 10. Temperature sensor II, 11. First lubrication point, 12. Flow sensor II, 13. Solenoid valve II, 14. Solenoid valve III, 15. Temperature sensor III, 16. Second lubrication point, 17. Flow sensor III, 18. Electronic control unit; DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] Embodiment 1

[0029] like Figure 1As shown, the lubrication and cooling device of the electric vehicle powertrain of the present invention includes a temperature sensor Ⅰ7, a temperature sensor Ⅱ10, a temperature sensor Ⅲ15, a flow sensor Ⅰ9, a flow sensor Ⅱ12, a flow sensor Ⅲ17, a hydraulic device and an electronic control unit 18; the hydraulic device includes a fuel tank 1, a coarse filter 2, an electronic oil pump 3, a fine filter 4, a radiator 5, a solenoid valve Ⅰ6, a solenoid valve Ⅱ13, and a solenoid valve Ⅲ14; the fuel tank 1 is sequentially connected to the coarse filter 2, the electronic oil pump 3, and the fine filter 4 to form a hydraulic oil branch AA, and after continuing to connect the radiator 5, hydraulic oil branches BB, CC, and DD are established respectively. The hydraulic oil temperature at these three places is lower than that of the hydraulic oil branch AA because it has been cooled by the radiator. After the hydraulic oil branch DD is connected to the solenoid valve Ⅰ6, it mainly forms the hydraulic oil branch EE. After the hydraulic oil branch BB is connected to the solenoid valve Ⅲ14, it mainly forms the hydraulic oil branch GG. After the hydraulic oil branch AA is connected to the solenoid valve Ⅱ13, it mainly forms the hydraulic oil branch FF. The hydraulic oil branch DD is connected to the A1 port of the solenoid valve Ⅰ6, the A3 port of the solenoid valve Ⅰ6 is connected to the hydraulic oil branch EE, the hydraulic oil branch EE is connected to the first cooling point 8, and the A4 port of the solenoid valve Ⅰ6 is also connected to the first cooling point 8 through the hydraulic pipeline. The hydraulic oil branch EE is connected; the hydraulic oil branch AA is connected to the B1 port of the solenoid valve Ⅱ13, the hydraulic oil branch CC is connected to the B2 port of the solenoid valve Ⅱ13, the B3 port of the solenoid valve Ⅱ13 is connected to the hydraulic oil branch FF, and the hydraulic oil branch FF is connected to the B4 port of the solenoid valve Ⅱ13, the C2 port of the solenoid valve Ⅲ14, the A2 port of the solenoid valve Ⅰ6, and the first lubrication point 11 in sequence through the hydraulic pipeline; the hydraulic oil branch BB is connected to the C1 port of the solenoid valve Ⅲ14, the C3 port of the solenoid valve Ⅲ14 connected to the hydraulic oil branch GG, the C4 port of the solenoid valve III14 is connected to the hydraulic oil branch GG through a hydraulic pipeline, and the hydraulic oil branch GG is connected to the second lubrication point 16; the first cooling point 8 is sequentially installed with a temperature sensor I7 and a flow sensor I9, which are respectively used to record the temperature of the first cooling point 8 and the flow of hydraulic oil flowing into it, the first lubrication point 11 is sequentially installed with a temperature sensor II10 and a flow sensor II12, which are respectively used to record the temperature of the first lubrication point 11 and the flow of hydraulic oil flowing into it, the second lubrication point 16 is sequentially installed with a temperature sensor III15 and a flow sensor III17, which are respectively used to record the temperature of the second lubrication point 16 and the flow of hydraulic oil flowing into it; the electronic oil pump 3, the solenoid valve I6, the solenoid valve II13, the solenoid valve III14, the temperature sensor I7, the temperature sensor II10, the temperature sensor III15, the flow sensor I9, the flow sensor II12, and the flow sensor III17 are respectively connected to the electronic control unit 18;

[0030] like Figure 2 The lubrication and cooling control method of the electric vehicle powertrain shown in the figure is specifically operated as follows:

[0031] 1) respectively detecting the temperature T1 of the first cooling point 8 and the hydraulic oil flow rate q1 flowing therein, the temperature T2 of the first lubrication point 11 and the hydraulic oil flow rate q2 flowing therein, and the temperature T3 of the second lubrication point 16 and the hydraulic oil flow rate q3 flowing therein; the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are all set with at least two target temperature ranges, namely T1 and T2;

[0032] 2) Based on the target temperature and target flow rate settings of the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 by the electronic control unit 18, the three solenoid valves are controlled to be in corresponding states respectively. The specific working details of each state are as follows:

[0033] A. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T1 respectively, the solenoid valve I6, the solenoid valve II13, and the solenoid valve III14 are in the states of no potential, no potential, and no potential respectively. At this time, the hydraulic oil (already cooled) in the hydraulic oil branch DD passes through the A1 and A3 ports of the solenoid valve I6 in turn and flows into the hydraulic oil branch EE. The hydraulic oil in the hydraulic oil branch EE finally flows into the first cooling point 8 to cool down the components of the first cooling point 8 so that their actual temperature is within the range of T1; the hydraulic oil in the hydraulic oil branch AA (not cooled) The hydraulic oil in the hydraulic oil branch FF flows into the first lubrication point 11, and is used to cool and lubricate the components of the first lubrication point 11, so that the actual temperature thereof is within the range of T2. The hydraulic oil in the hydraulic oil branch BB (which has been cooled) flows into the hydraulic oil branch GG through the ports C1 and C3 of the solenoid valve III 14, and is used to cool and lubricate the components of the second lubrication point 16, so that the actual temperature thereof is within the range of T1.

[0034] B. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T2 respectively, the solenoid valve I6, the solenoid valve II13, and the solenoid valve III14 are in the states of no potential, no potential, and potential respectively. At this time, the hydraulic oil (already cooled) of the hydraulic oil branch DD passes through the A1 and A3 ports of the solenoid valve I6 in turn and flows into the hydraulic oil branch EE. The hydraulic oil of the hydraulic oil branch EE finally flows into the first cooling point 8, which is used to cool the components of the first cooling point 8 so that their actual temperature is within the range of T1; the hydraulic oil of the hydraulic oil branch AA (not cooled) passes through the B1 and B3 ports of the solenoid valve II13 in turn and flows into the hydraulic oil branch FF. The hydraulic oil of the hydraulic oil branch FF finally flows into The first lubrication point 11 is used to cool and lubricate the components of the first lubrication point 11 so that their actual temperature is within the range of T2; the hydraulic oil (already cooled) of the hydraulic oil branch BB passes through the C1 and C3 ports of the solenoid valve III14 in sequence and flows into the hydraulic oil branch GG, while the hydraulic oil (not cooled) from the hydraulic oil branch AA on the hydraulic oil branch FF also passes through the C2 and C4 ports of the solenoid valve III14 in sequence and flows into the hydraulic oil branch GG. At this time, the temperature of the hydraulic oil on the hydraulic oil branch GG will rise relatively, and the viscosity of the hydraulic oil here will also change accordingly, because the hydraulic oil (not cooled) from the hydraulic oil branch AA is mixed with the hydraulic oil (already cooled) of the hydraulic oil branch BB. The two hydraulic oils flowing into the hydraulic oil branch GG are combined and flow into the second lubrication point 16 together, which is used to cool and lubricate the components of the second lubrication point 16 so that their actual temperature is within the range of T2;

[0035] C. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T1 respectively, the solenoid valve I6, the solenoid valve II13, and the solenoid valve III14 are in the states of no potential, potential, and no potential respectively. At this time, the hydraulic oil (already cooled) in the hydraulic oil branch DD passes through the A1 and A3 ports of the solenoid valve I6 in turn and flows into the hydraulic oil branch EE. The hydraulic oil in the hydraulic oil branch EE finally flows into the first cooling point 8 to cool the components of the first cooling point 8 so that their actual temperature is within the range of T1. The hydraulic oil of line AA (not cooled) flows into the hydraulic oil branch FF through the B1 and B3 ports of the solenoid valve II13 in turn. At the same time, the hydraulic oil of the hydraulic oil branch CC (already cooled) flows into the hydraulic oil branch FF through the B2 and B4 ports of the solenoid valve II13 in turn. At this time, the temperature of the hydraulic oil on the hydraulic oil branch FF will drop relatively, and the viscosity of the hydraulic oil here will also change accordingly, because the hydraulic oil (already cooled) from the hydraulic oil branch CC is mixed on the basis of the hydraulic oil of the hydraulic oil branch AA (not cooled). The two hydraulic oils flowing into the hydraulic oil branch FF are combined and flow into the first lubrication point 11 together, which is used to cool and lubricate the components of the first lubrication point 11 so that their actual temperature is within the range of T1; the hydraulic oil of the hydraulic oil branch BB (already cooled) flows into the hydraulic oil branch GG through the C1 and C3 ports of the solenoid valve III14 in turn. The hydraulic oil of the hydraulic oil branch GG finally flows into the second lubrication point 16, which is used to cool and lubricate the components of the second lubrication point 16 so that their actual temperature is within the range of T1;

[0036] D. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T2 respectively, the solenoid valve I6, the solenoid valve II13, and the solenoid valve III14 are in the states of no potential, potential, and potential respectively. At this time, the hydraulic oil (already cooled) in the hydraulic oil branch DD passes through the A1 and A3 ports of the solenoid valve I6 in turn and flows into the hydraulic oil branch EE. The hydraulic oil in the hydraulic oil branch EE finally flows into the first cooling point 8 to cool the components of the first cooling point 8 so that their actual temperature is within the range of T1; the hydraulic oil branch DD is in the state of no potential, potential, and potential respectively. The hydraulic oil of AA (uncooled) passes through the B1 and B3 ports of the solenoid valve Ⅱ13 in sequence and flows into the hydraulic oil branch FF. At the same time, the hydraulic oil of the hydraulic oil branch CC (cooled) passes through the B2 and B4 ports of the solenoid valve Ⅱ13 in sequence and flows into the hydraulic oil branch FF. At this time, the temperature of the hydraulic oil on the hydraulic oil branch FF will drop relatively, and the viscosity of the hydraulic oil here will also change accordingly, because the hydraulic oil from the hydraulic oil branch CC (cooled) is mixed with the hydraulic oil of the hydraulic oil branch AA (uncooled). The hydraulic oils flowing into the hydraulic oil branch FF from two paths converge and flow into the first lubrication point 11 together, and are used to cool and lubricate the components of the first lubrication point 11, so that their actual temperature is within the range of T1; the hydraulic oil of the hydraulic oil branch BB (already cooled) passes through the C1 and C3 ports of the solenoid valve III 14 in sequence and flows into the hydraulic oil branch GG, and part of the hydraulic oil that previously started from the hydraulic oil branch AA and the pressure oil branch CC and converged and flowed into the hydraulic oil branch FF also passes through the C2 and C4 ports of the solenoid valve III in sequence and flows into the hydraulic oil branch GG. At this time, the temperature of the hydraulic oil on the hydraulic oil branch GG will rise relatively, and the viscosity of the hydraulic oil here will also change accordingly, because the hydraulic oil from part of the hydraulic oil branch AA (not cooled) is mixed with the hydraulic oil of the hydraulic oil branch BB (already cooled). The hydraulic oils that converge and flow into the hydraulic oil branch GG from two paths finally flow into the second lubrication point 16, and are used to cool and lubricate the components of the second lubrication point 16, so that their actual temperature is within the range of T2;

[0037] E. When the target temperature ranges of T1, T2 and T3 are T2, T1 and T1 respectively, solenoid valve Ⅰ6, solenoid valve Ⅱ13 and solenoid valve Ⅲ14 are in potential-gained, potential-gained and potential-loss states respectively, and the hydraulic oil of hydraulic oil branch AA (not cooled) passes through B1 and B3 ports of solenoid valve Ⅱ13 in sequence and flows into hydraulic oil branch FF. At the same time, the hydraulic oil of hydraulic oil branch CC (already cooled) passes through B2 and B4 ports of solenoid valve Ⅱ13 in sequence and flows into hydraulic oil branch FF. At this time, the temperature of hydraulic oil on hydraulic oil branch FF will drop relatively, and the viscosity of hydraulic oil here will also change accordingly, because the hydraulic oil from hydraulic oil branch CC (already cooled) is mixed with the hydraulic oil of hydraulic oil branch AA (not cooled). The hydraulic oils from the two routes that converge and flow into the hydraulic oil branch FF flow into the first lubrication port 11 together, and are used to cool and lubricate the components of the first lubrication point 11, so that their actual temperature is within the range of T1; the hydraulic oils that previously departed from the hydraulic oil branch AA and the pressure oil branch CC and converged and flowed into the hydraulic oil branch FF also passed through the A2 port and A4 port of the solenoid valve Ⅰ6 in turn, and flowed into the hydraulic oil branch EE. At the same time, the hydraulic oil of the hydraulic oil branch DD (which has been cooled) passed through the A1 port and A3 port of the solenoid valve Ⅰ6 in turn, and flowed into the hydraulic oil branch EE. The temperature of the hydraulic oil on the hydraulic oil branch EE will rise relatively, and the viscosity of the hydraulic oil here will also change accordingly, because The hydraulic oil (already cooled) from part of the hydraulic oil branch AA is mixed with the hydraulic oil (already cooled) in the hydraulic oil branch DD. The hydraulic oil from the two paths that flows into the hydraulic oil branch EE finally flows into the first cooling port 8, which is used to cool the components of the first cooling point 8 so that their actual temperature is within the range of T2. The hydraulic oil (already cooled) in the hydraulic oil branch BB passes through the C1 and C3 ports of the solenoid valve III 14 in sequence and flows into the hydraulic oil branch GG. The hydraulic oil in the hydraulic oil branch GG finally flows into the second lubrication port 16, which is used to cool and lubricate the components of the second lubrication point 16 so that their actual temperature is within the range of T1.

[0038] 3) Based on the information monitored in real time by the electronic control unit 18, the target required flow rates q of the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are calculated respectively. x1 ,q x2 ,q x3 :

[0039]

[0040] Where: P t --efficiency loss, unit Kw; C--lubricating oil specific heat, unit kJ / (kg·k); p--lubricating oil density, unit kg / m 3 ; Δt=TT m --Temperature difference, unit: °C; q x-- Target required flow, unit L / min; η--lubrication coefficient; T--actual detection temperature, unit ℃; T m --Standard temperature, unit: °C;

[0041] 4) When the actual flow rate q1, q2, q3 of each point is detected, or none of them meets the respective target flow rate q x1 ,q x2 ,q x3 When the electronic control unit drives the electronic oil pump to accelerate, the actual flow rate q1, q2, q3 at each point meets the target flow rate q x1 ,q x2 ,q x3 ; If satisfied, the electronic oil pump is controlled to move at a constant speed;

[0042] In the lubrication and cooling control method of the electric vehicle powertrain, the temperature range of T1 is (0, 75] ° C, and the temperature range of T2 is (75, 100] ° C; when the target temperature of each point is in the range of T1, the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are respectively used to calculate the standard temperature T of the target required flow rate. 1m , T 2m , T 3m is: 100xR1℃, 104xR1℃, 106xR1℃, the demand coefficient R1 is 0.5; when the target temperature of each point is in the range of T2, the standard temperature T used to calculate the target demand flow rate in the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are respectively 1m , T 2m , T 3m The demand coefficient R2 is: 110x R2℃, 112xR2℃, 113x R2℃, and the demand coefficient R2 is 0.55.

[0043] In the lubrication and cooling control method of the electric vehicle powertrain, when the actual temperatures of T1, T2, and T3 are respectively within the temperature ranges of T2, T2, and T2, η is 1.25; otherwise, η is 1.1;

[0044] Embodiment 2

[0045] Assuming that when the target temperature of each point is in the range of T1, the standard temperatures T used to calculate the target required flow rate at the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are respectively 1m , T 2m , T 3m 100xR1=100x0.5=50°C, 104xR1=104x0.5=52°C, 106xR1=106x0.5=53°C, and the demand coefficient R1 is 0.5. The control method of the lubrication and cooling device is as follows:

[0046] 1) Assume that the actual temperature T1 of the first cooling point 8 and the hydraulic oil flow rate q1 thereof are respectively 70°C and 8.52 L / min, the actual temperature T2 of the first lubrication point 11 and the hydraulic oil flow rate q2 thereof are respectively 70°C and 9.43 L / min, and the actual temperature T3 of the second lubrication point 16 and the hydraulic oil flow rate q3 thereof are respectively 72°C and 9.01 L / min;

[0047] 2) Assuming that the target temperature of each point is in the range of T1, T1, T1, the standard temperature T used to calculate the target required flow rate at the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 1m , T 2m , T 3m They are: 50℃, 52℃, 53℃;

[0048] 3) The solenoid valve I6, the solenoid valve II13, and the solenoid valve III14 are respectively in the states of no potential, potential, and no potential, and the hydraulic oil flow path on each hydraulic branch is carried out as described above;

[0049] 4) Based on the information monitored in real time by the electronic control unit 18, the target required flow rates q of the first cooling point 8, the first lubrication point 11, and the second lubrication point 16 are calculated respectively. x1 ,q x2 ,q x3 for:

[0050]

[0051]

[0052]

[0053] Where: P t --efficiency loss, 5.1Kw; C--lubricating oil specific heat, 2.1kJ / (kg·k); p--lubricating oil density, 0.97x10 3 kg / m 3 ; Δt1=T1-T 1m --Temperature difference, 20℃; Δt2=T2-T 2m --Temperature difference, 18°C, Δt3 = T3 - T 3m --Temperature difference, 19℃; q x --Target demand flow, L / min; η--1.1; demand coefficient R1--0.5;

[0054] 4) The actual flow rates of 8.52 L / min, 9.43 L / min, and 9.01 L / min at each point are detected to meet the respective target flow rates of 8.26 L / min, 9.18 L / min, and 8.7 L / min, and the electronic oil pump 3 is controlled to continue to move at a constant speed;

[0055] In this way, the lubrication and cooling control method of the electric vehicle powertrain collects the detection information of each sensor in real time, and based on the designed control algorithm, detects and compensates the actual flow of each lubrication and cooling point in real time, meets the target required flow of the motor, controller, reducer, etc. in the electric vehicle powertrain, and improves the reliability of lubrication and cooling of the electric vehicle powertrain. At the same time, the lubrication and cooling device of the electric vehicle powertrain is simple, only a single type of hydraulic oil is needed, and the temperature (viscosity) of the hydraulic oil is adjusted by timely mixing hydraulic oils of different temperatures - cooled hydraulic oil and non-cooled hydraulic oil - by controlling the power on / off of the corresponding solenoid valve, so as to simultaneously meet the different requirements of the motor, controller, reducer, etc. in the electric vehicle powertrain for the temperature of the lubrication and cooling oil.

Claims

1. A lubrication and cooling device for an electric vehicle powertrain, comprising a temperature sensor I, a temperature sensor II, a temperature sensor III, a flow sensor I, a flow sensor II, a flow sensor III, a hydraulic device and an electronic control unit; characterized in that: The hydraulic device includes an oil tank, a coarse filter, an electronic oil pump, a fine filter, a radiator, a solenoid valve I, a solenoid valve II, and a solenoid valve III; the oil tank is connected to the coarse filter, the electronic oil pump, and the fine filter in sequence to form a hydraulic oil branch AA, and then connected to the radiator to form hydraulic oil branches BB, hydraulic oil branches CC, and hydraulic oil branches DD respectively. After the hydraulic oil branch DD is connected to the solenoid valve I, it mainly forms a hydraulic oil branch EE. After the hydraulic oil branch BB is connected to the solenoid valve III, it mainly forms a hydraulic oil branch GG. After the hydraulic oil branch AA is connected to the solenoid valve II, it mainly forms a hydraulic oil branch FF. The hydraulic oil branch DD is connected to the A1 port of the solenoid valve I, and the A3 port of the solenoid valve I is connected to the hydraulic oil branch EE. The branch EE is connected to the first cooling point, and the A4 port of the solenoid valve I is also connected to the hydraulic oil branch EE through a hydraulic pipeline; the hydraulic oil branch AA is connected to the B1 port of the solenoid valve II, the hydraulic oil branch CC is connected to the B2 port of the solenoid valve II, the B3 port of the solenoid valve II is connected to the hydraulic oil branch FF, and the hydraulic oil branch FF is also connected to the B4 port of the solenoid valve II, the C2 port of the solenoid valve III, the A2 port of the solenoid valve I and the first lubrication point in sequence through a hydraulic pipeline; the hydraulic oil branch BB is connected to the C1 port of the solenoid valve III, the C3 port of the solenoid valve III is connected to the hydraulic oil branch GG, the C4 port of the solenoid valve III is connected to the hydraulic oil branch GG through a hydraulic pipeline, and the hydraulic oil branch GG is connected to the second lubrication point; The first cooling point is sequentially installed with a temperature sensor I and a flow sensor I, which are respectively used to record the temperature of the first cooling point and the flow rate of hydraulic oil flowing therein; the first lubrication point is sequentially installed with a temperature sensor II and a flow sensor II, which are respectively used to record the temperature of the first lubrication point and the flow rate of hydraulic oil flowing therein; the second lubrication point is sequentially installed with a temperature sensor III and a flow sensor III, which are respectively used to record the temperature of the second lubrication point and the flow rate of hydraulic oil flowing therein; The electronic oil pump, solenoid valve I, solenoid valve II, solenoid valve III, temperature sensor I, temperature sensor II, temperature sensor III, flow sensor I, flow sensor II, flow sensor III are respectively connected to the electronic control unit.

2. A control method for the lubrication and cooling device according to claim 1, characterized in that: The control method comprises the following specific steps: 1) respectively detecting the temperature T1 of the first cooling point and the hydraulic oil flow rate q1 flowing therein, the temperature T2 of the first lubrication point and the hydraulic oil flow rate q2 flowing therein, and the temperature T3 of the second lubrication point and the hydraulic oil flow rate q3 flowing therein; the first cooling point, the first lubrication point, and the second lubrication point are all set with two target temperature ranges, namely T1 and T2; 2) Based on the target temperature and target flow setting of the first cooling point, the first lubrication point, and the second lubrication point by the electronic control unit, the three solenoid valves are controlled to be in corresponding states respectively. The specific working details of each state are as follows: A. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T1 respectively, solenoid valves Ⅰ, Ⅱ, and Ⅲ are in the states of no potential, no potential, and no potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD flows into hydraulic oil branch EE through ports A1 and A3 of solenoid valve Ⅰ in sequence, and the hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA flows into hydraulic oil branch FF through ports B1 and B3 of solenoid valve Ⅱ in sequence, and the hydraulic oil of hydraulic oil branch FF finally flows into the first lubrication point; the hydraulic oil of hydraulic oil branch BB flows into hydraulic oil branch GG through ports C1 and C3 of solenoid valve Ⅲ in sequence, and the hydraulic oil of hydraulic oil branch GG finally flows into the second lubrication point; B. When the target temperature ranges of T1, T2, and T3 are T1, T2, and T2 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, no potential, and potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve I in turn and flows into hydraulic oil branch EE, and the hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve II in turn and flows into hydraulic oil branch FF, and the hydraulic oil of hydraulic oil branch FF finally flows into the first lubrication point; the hydraulic oil of hydraulic oil branch BB passes through the C1 and C3 ports of solenoid valve III in turn and flows into hydraulic oil branch GG, and at the same time, part of the hydraulic oil flowing out of the B3 port of solenoid valve II also passes through the C2 and C4 ports of solenoid valve III in turn and flows into hydraulic oil branch GG, and the hydraulic oils flowing into hydraulic oil branch GG from the two ways are combined and flow into the second lubrication point together; C. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T1, respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, potential, and no potential, respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve I in turn and flows into hydraulic oil branch EE, and the hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve II in turn and flows into hydraulic oil branch FF, and at the same time, the hydraulic oil of hydraulic oil branch CC passes through the B2 and B4 ports of solenoid valve II in turn and flows into hydraulic oil branch FF, and the hydraulic oils flowing into hydraulic oil branch FF from the two paths are combined and flow into the first lubrication point together; the hydraulic oil of hydraulic oil branch BB passes through the C1 and C3 ports of solenoid valve III in turn and flows into hydraulic oil branch GG, and the hydraulic oil of hydraulic oil branch GG finally flows into the second lubrication point; D. When the target temperature ranges of T1, T2, and T3 are T1, T1, and T2 respectively, solenoid valve I, solenoid valve II, and solenoid valve III are in the states of no potential, potential, and potential respectively. At this time, the hydraulic oil of hydraulic oil branch DD passes through the A1 and A3 ports of solenoid valve I in turn and flows into hydraulic oil branch EE. The hydraulic oil of hydraulic oil branch EE finally flows into the first cooling point; the hydraulic oil of hydraulic oil branch AA passes through the B1 and B3 ports of solenoid valve II in turn and flows into hydraulic oil branch FF. At the same time, the hydraulic oil of hydraulic oil branch CC passes through the solenoid valve II in turn and flows into hydraulic oil branch FF. The B2 and B4 ports of the solenoid valve II flow into the hydraulic oil branch FF. The hydraulic oil flowing into the hydraulic oil branch FF from two directions is combined and flows into the first lubrication point together. The hydraulic oil of the hydraulic oil branch BB flows into the hydraulic oil branch GG through the C1 and C3 ports of the solenoid valve III in sequence. The hydraulic oil that previously started from the hydraulic oil branch AA and the pressure oil branch CC and flowed into the hydraulic oil branch FF at the same time also flows into the hydraulic oil branch GG through the C2 and C4 ports of the solenoid valve III in sequence. The hydraulic oil flowing into the hydraulic oil branch GG from two directions finally flows into the second lubrication point. E. When the target temperature ranges of T1, T2, and T3 are T2, T1, and T1 respectively, solenoid valves I, II, and III are in the states of gaining potential, gaining potential, and not gaining potential respectively, and the hydraulic oil of hydraulic oil branch AA flows into hydraulic oil branch FF through ports B1 and B3 of solenoid valve II in turn. At the same time, the hydraulic oil of hydraulic oil branch CC flows into hydraulic oil branch FF through ports B2 and B4 of solenoid valve II in turn. The hydraulic oils of the two channels flowing into hydraulic oil branch FF flow into the first lubrication port together; previously, the hydraulic oils of hydraulic oil branch CC flow into hydraulic oil branch FF through ports B2 and B4 of solenoid valve II in turn. The hydraulic oil from hydraulic oil branch AA and hydraulic oil branch CC that flows into hydraulic oil branch FF also flows into hydraulic oil branch EE through ports A2 and A4 of solenoid valve I in turn; the hydraulic oil from hydraulic oil branch DD flows into hydraulic oil branch EE through ports A1 and A3 of solenoid valve I in turn, and the hydraulic oil from the two channels that flows into hydraulic oil branch EE finally flows into the first cooling port; the hydraulic oil from hydraulic oil branch BB flows into hydraulic oil branch GG through ports C1 and C3 of solenoid valve III in turn, and the hydraulic oil from hydraulic oil branch GG finally flows into the second lubrication port; 3) Based on the information monitored in real time by the electronic control unit, the target required flow rate q of the first cooling point, the first lubrication point, and the second lubrication point is calculated respectively. x1 ,q x2 ,q x3 : Where: P t --efficiency loss, unit Kw; C--lubricating oil specific heat, unit kJ / (kg·k); p--lubricating oil density, unit kg / m 3 ; Δt=TT m --Temperature difference, unit: °C; q x --Target required flow rate, in L / min; η--lubrication coefficient; T--actual detection temperature, unit ℃; T m --Standard temperature, unit: °C; 4) When the actual flow rate q1, q2, q3 of each point is detected, or none of them meets the respective target flow rate q x1 ,q x2 ,q x3 When the electronic control unit drives the electronic oil pump to accelerate, the actual flow rate q1, q2, q3 at each point meets the target flow rate q x1 ,q x2 ,q x3 ; If satisfied, the electronic oil pump is controlled to move at a constant speed.

3. The control method according to claim 2, characterized in that: The temperature range of T1 is (0, 75] ℃, and the temperature range of T2 is (75, 100] ℃; when the target temperature of each point is in the range of T1, the standard temperature T used to calculate the target required flow rate at the first cooling point, the first lubrication point, and the second lubrication point is 1m , T 2m , T 3m is: 100xR1℃, 104xR1℃, 106xR1℃, the demand coefficient R1 is 0.5; when the target temperature of each point is in the range of T2, the standard temperature T used to calculate the target demand flow rate in the first cooling point, the first lubrication point, and the second lubrication point is 1m , T 2m , T 3m The demand coefficient R2 is: 110x R2℃, 112xR2℃, 113x R2℃. The demand coefficient R2 is 0.55.

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