Automatic transmission electric oil pump system, low temperature starting method, and vehicle

Abstract

The application provides an automatic transmission electric oil pump system, a low-temperature starting method and a vehicle, and comprises a low-pressure oil pump, a high-pressure oil pump, a state control valve and an oil pump motor; the low-pressure oil pump is communicated with a cooling system of a clutch through a low-pressure oil path; the high-pressure oil pump is communicated with an execution system of the clutch through a high-pressure oil path; the state control valve is connected with the low-pressure oil path and the high-pressure oil path respectively; and the driving end of the oil pump motor is connected with the low-pressure oil pump and the high-pressure oil pump respectively. In the application, the state control valve is arranged in the electric oil pump system during low-temperature starting, the low-pressure oil path is conducted through the state control valve, the oil in the low-pressure oil path flows back to the oil pan, and the technical problem that the low-temperature starting load of the oil pump motor is too large is effectively solved; after the oil pump motor is started, when the oil in the low-pressure oil path is insufficient, the low-pressure oil path is conducted through the state control valve, the high-pressure oil pump supplements the oil in the low-pressure oil path.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to an automatic transmission electric oil pump system, a low-temperature starting method and a vehicle. BACKGROUND

[0002] Automatic transmission of passenger cars is widely used, and efficiency is the most important performance evaluation index of automatic transmission. Improving the efficiency of automatic transmission is the technical trend of industry development. The execution system of automatic transmission is mostly hydraulic scheme. Compared with mechanical pump, electric oil pump can be used on demand, especially in high-low pressure split automatic transmission, one motor can drive two oil pumps to realize high pressure driving and low pressure cooling function, which greatly improves the efficiency of the transmission.

[0003] The electric oil pump has obvious advantages, but the biggest disadvantage is that the starting current is large, especially in low temperature state, the oil viscosity is large, which leads to large motor starting load, and there is a problem of low temperature starting difficulty.

[0004] At present, there is no effective solution to the above problems. SUMMARY

[0005] The main purpose of the present application is to provide an automatic transmission electric oil pump system, a low-temperature starting method and a vehicle, to solve the technical problem of difficulty in starting electric oil pump in low temperature state.

[0006] In order to achieve the above purpose, according to one aspect of the present application, an automatic transmission electric oil pump system is provided, comprising: a low-pressure oil pump, the low-pressure oil pump being communicated with a cooling system of a clutch through a low-pressure oil circuit; a high-pressure oil pump, the high-pressure oil pump being communicated with an execution system of the clutch through a high-pressure oil circuit; a state control valve, the state control valve being connected with the low-pressure oil circuit and the high-pressure oil circuit respectively, the state control valve having a first state of making the low-pressure oil circuit and a return oil circuit conductive, a second state of making the low-pressure oil circuit and the high-pressure oil circuit conductive, and a third state of making the low-pressure oil circuit, the high-pressure oil circuit and the return oil circuit not conductive with each other; and an oil pump motor, a driving end of the oil pump motor being connected with the low-pressure oil pump and the high-pressure oil pump respectively.

[0007] Further, the state control valve is a three-position three-way electromagnetic valve, the state control valve is provided with a first oil port, a second oil port and a third oil port, the first oil port being connected with the low-pressure oil circuit, the second oil port being connected with the high-pressure oil circuit, and the third oil port being connected with an oil pan.

[0008] According to another aspect of the present application, there is provided a low-temperature starting method for an automatic transmission electric oil pump system, the starting method comprising: collecting working parameters of the electric oil pump system, wherein the working parameters comprise: system oil temperature, system oil pressure and current of the oil pump motor; comparing the system oil temperature with a preset oil temperature to obtain a comparison result; generating a control instruction set for controlling the state control valve to execute a target working mode in the case that the comparison result meets a preset condition, wherein the target working mode comprises: a first working mode of making the low-pressure oil circuit and the return oil circuit conductive, and a second working mode of making the low-pressure oil circuit, the high-pressure oil circuit and the return oil circuit not conductive to each other; and adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure in the target working mode.

[0009] Further, in the case that the comparison result meets the preset condition, generating the control instruction set comprises: generating a first target control instruction in the control instruction set for controlling the state control valve to execute the first working mode in the case that the system oil temperature is less than the preset oil temperature; and generating a second target control instruction in the control instruction set for controlling the state control valve to execute the second working mode in the case that the system oil temperature is greater than or equal to the preset oil temperature.

[0010] Further, in the target working mode, adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure comprises: adjusting the rotating speed of the oil pump motor to a first working rotating speed in the case of the first working mode, and judging whether the current of the oil pump motor exceeds a rated current of the oil pump motor, if not, adjusting the rotating speed of the oil pump motor to a second working rotating speed, wherein the second working rotating speed is greater than the first working rotating speed; and in the case that the rotating speed of the oil pump motor is kept at the second working rotating speed, judging whether the system oil pressure exceeds an allowable oil pressure, if not, adjusting the rotating speed of the oil pump motor to a third working rotating speed, wherein the third working rotating speed is greater than the second working rotating speed.

[0011] Further, in the target working mode, adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure further comprises: in the case that the rotating speed of the oil pump motor is kept at the first working rotating speed, if the current of the oil pump motor exceeds the rated current of the oil pump motor, adjusting the rotating speed of the oil pump motor to zero.

[0012] Further, in the target working mode, adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure further comprises: in the case that the rotating speed of the oil pump motor is kept at the second working rotating speed, if the system oil pressure exceeds the allowable oil pressure, adjusting the rotating speed of the oil pump motor to the first working rotating speed.

[0013] Further, in the target working mode, the speed of the oil pump motor is adjusted according to the current of the oil pump motor and the system oil pressure, and further comprising: in the case of the second working mode, the speed of the oil pump motor is adjusted to the second working speed, and it is judged whether the current of the oil pump motor exceeds the rated current of the oil pump motor, if not, it is judged whether the system oil pressure exceeds the allowable oil pressure, if not, the speed of the oil pump motor is adjusted to the third working speed.

[0014] Further, after the speed of the oil pump motor is adjusted to the second working speed and maintained for the first preset time, the speed of the oil pump motor is adjusted to the fourth working speed and maintained for the second preset time, and then it is judged whether the system oil pressure exceeds the allowable oil pressure, if not, the speed of the oil pump motor is adjusted to the third working speed, wherein the fourth working speed is greater than the second working speed and less than the third working speed.

[0015] Further, the speed of the oil pump motor is adjusted by setting a speed-up slope.

[0016] According to another aspect of the present application, a vehicle is provided, comprising an automatic transmission electric oil pump system, which is the automatic transmission electric oil pump system described above.

[0017] By applying the technical solution of the present application, when starting at low temperature, the viscosity of the oil in the oil circuit is large, resulting in a large load of the oil pump motor. By setting a state control valve in the electric oil pump system, the low-pressure oil circuit is connected to the oil return circuit by adjusting the state control valve, and the oil in the low-pressure oil circuit flows back to the oil pan, i.e. the low-pressure oil pump is in an idle state, thereby reducing the starting load of the oil pump motor and effectively improving the technical problem of excessive low-temperature starting load of the oil pump motor. In addition, after the oil pump motor starts, the low-pressure oil pump and the high-pressure oil pump work normally. When the oil in the low-pressure oil circuit is insufficient, the low-pressure oil circuit is connected to the high-pressure oil circuit by adjusting the state control valve, and the high-pressure oil pump supplies oil to the low-pressure oil circuit. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description, explain the application. The specific embodiments of the application and its attendant advantages are best understood from the accompanying drawings taken together with the detailed description of the application. In the drawings:

[0019] Figure 1 The structure schematic diagram of an embodiment of an automatic transmission electric oil pump system according to the present application is shown;

[0020] Figure 2 The flow chart of a low-temperature starting method of an automatic transmission electric oil pump system according to the present application is shown;

[0021] Figure 3A flowchart illustrating a low temperature start method of another automatic transmission electric oil pump system according to the present application is shown.

[0022] Wherein, the above figures include the following reference signs:

[0023] 1, proportional flow valve; 2, pressure relief valve; 3, oil pump motor; 4, low pressure oil pump; 5, high pressure oil pump; 6, oil suction filter; 7, oil sump; 8, check valve; 9, high pressure safety valve; 10, pressure sensor; 11, state control valve; 12, oil temperature sensor; 13, accumulator. DETAILED DESCRIPTION

[0024] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0025] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it will be further understood that the terms "comprise" and / or "include" when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof.

[0026] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described figures are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged as appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in various different forms, and should not be interpreted as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided in order to make the present disclosure complete and comprehensive, and to adequately convey the ideas of these exemplary embodiments to those of ordinary skill in the art. In the drawings, the thickness of layers and regions can be exaggerated for clarity, and the same reference numerals are used to denote the same elements, so that a description thereof will be omitted.

[0028] Embodiment 1

[0029] In combination Figure 1 According to specific embodiments of the present application, an automatic transmission electric oil pump system is provided.

[0030] Specifically, the automatic transmission electric oil pump system comprises a low-pressure oil pump 4, a high-pressure oil pump 5, a state control valve 11 and an oil pump motor 3. The low-pressure oil pump 4 is communicated with a cooling system of a clutch through a low-pressure oil circuit, the high-pressure oil pump 5 is communicated with an execution system of the clutch through a high-pressure oil circuit, the state control valve 11 is connected with the low-pressure oil circuit and the high-pressure oil circuit respectively, the state control valve 11 has a first state of making the low-pressure oil circuit and a return oil circuit conductive, a second state of making the low-pressure oil circuit and the high-pressure oil circuit conductive, and a third state of making the low-pressure oil circuit, the high-pressure oil circuit and the return oil circuit not conductive, and the driving end of the oil pump motor 3 is connected with the low-pressure oil pump 4 and the high-pressure oil pump 5 respectively.

[0031] In the embodiments of the present application, when starting at low temperature, the viscosity of the oil in the oil circuit is large, resulting in large load of the oil pump motor 3. The state control valve 11 is arranged in the electric oil pump system, the low-pressure oil circuit is made conductive with the return oil circuit by adjusting the state control valve 11, the oil in the low-pressure oil circuit flows back to the oil pan 7, that is, the low-pressure oil pump 4 is in an idle state, thereby reducing the starting load of the oil pump motor 3 and effectively improving the technical problem of large low-temperature starting load of the oil pump motor 3. In addition, after the oil pump motor 3 starts, the low-pressure oil pump 4 and the high-pressure oil pump 5 work normally, when the oil in the low-pressure oil circuit is insufficient, the low-pressure oil circuit is made conductive with the high-pressure oil circuit by adjusting the state control valve 11, and the high-pressure oil pump 5 supplements the oil for the low-pressure oil circuit.

[0032] Further, the state control valve 11 is a three-position three-way electromagnetic valve, the state control valve 11 is provided with a first oil port, a second oil port and a third oil port, the first oil port is connected with the low-pressure oil circuit, the second oil port is connected with the high-pressure oil circuit, and the third oil port is connected with the oil pan 7. Specifically, as shown in Figure 1 by adjusting the working current of the state control valve 11, three working states of the state control valve 11 are realized. When the working current of the state control valve 11 is a first working current, the state control valve 11 is in a left position, that is, the spool of the state control valve 11 is in an intermediate position, the high-pressure oil circuit, the low-pressure oil circuit and the return oil circuit are not communicated. When the working current of the state control valve 11 is a second working current, the state control valve 11 is in a middle position, that is, the spool of the state control valve 11 seals the return oil circuit, the high-pressure oil circuit and the low-pressure oil circuit are communicated. When the working current of the state control valve 11 is a third working current, the state control valve 11 is in a right position, that is, the spool of the state control valve 11 seals the high-pressure oil circuit, the low-pressure oil circuit and the return oil circuit are communicated.

[0033] As shown in Figure 1As shown, the low-pressure oil circuit is also equipped with an oil suction filter 6, a proportional flow valve 1, and a pressure relief valve 2. The oil suction filter 6 is located near the oil suction port of the low-pressure oil pump 4. After the low-pressure oil pump 4 starts, the oil is filtered through the oil suction filter 6 before entering the pump body. The proportional flow valve 1 is located near the oil outlet of the low-pressure oil pump 4. The proportional flow valve 1 is used to control the oil output of the low-pressure oil circuit, thereby adjusting the oil flow rate in the clutch cooling system as needed. The pressure relief valve 2 is connected to the low-pressure oil circuit via a pipeline. When the oil pressure in the low-pressure oil circuit exceeds the limit value, the pressure relief valve 2 opens, allowing some of the low-pressure oil to return to the oil pan 7.

[0034] like Figure 1 As shown, the high-pressure oil circuit also includes a one-way valve 8, an oil suction filter 6, a high-pressure safety valve 9, a pressure sensor 10, and an accumulator 13. The one-way valve 8 is located on the outlet side of the high-pressure oil pump 5, preventing high-pressure oil backflow and damage to the pump. The oil suction filter 6 is located near the suction port of the high-pressure oil pump 5; after the pump starts, the oil is filtered through the filter 6 before entering the pump body. The high-pressure safety valve 9 is located on the outlet side of the high-pressure oil pump 5; when the oil pressure in the high-pressure oil circuit exceeds the warning value, it releases pressure, protecting the high-pressure oil circuit. The pressure sensor 10 is located on the high-pressure oil circuit for real-time monitoring of the oil pressure. The accumulator 13 is located on the outlet side of the high-pressure oil pump 5; it stores a certain volume of high-pressure oil to meet the needs of the shift piston and clutch piston during continuous gear shifting.

[0035] The automatic transmission electric oil pump system is also equipped with an oil temperature sensor 12, which is used to monitor the temperature of the oil in the entire system in real time.

[0036] Example 2

[0037] In another embodiment of this application, a low-temperature start-up method for an automatic transmission electric oil pump system is also provided, for starting the automatic transmission electric oil pump system in the above embodiment, such as... Figure 2 As shown, the startup method includes the following steps:

[0038] Step S1: Collect the operating parameters of the electric oil pump system, including: system oil temperature, system oil pressure and oil pump motor current.

[0039] Step S2: Compare the system oil temperature with the preset oil temperature to obtain the comparison result.

[0040] Step S3: If the comparison result meets the preset conditions, generate a control instruction set. The control instruction set is used to control the state control valve to execute the target working mode. The target working mode includes: a first working mode that connects the low-pressure oil circuit and the return oil circuit, and a second working mode that disconnects the low-pressure oil circuit, the high-pressure oil circuit, and the return oil circuit.

[0041] Step S4: In the target working mode, the speed of the oil pump motor is adjusted according to the current of the oil pump motor and the system oil pressure.

[0042] According to the above implementation steps, by collecting the working parameters of the electric oil pump system, the real-time collected working parameters are compared with the preset parameters, and the control instruction set is generated according to the comparison result. In the case that the system oil temperature is lower than the preset oil temperature, the low-pressure oil way and the oil return way are connected, which effectively reduces the starting load of the oil pump motor and effectively improves the technical problem of large low-temperature starting load of the oil pump motor.

[0043] In step S3, in the case that the comparison result meets the preset condition, the control instruction set is generated, including: in the case that the system oil temperature is less than the preset oil temperature, the first target control instruction in the control instruction set is generated, and the first target control instruction is used to control the state control valve to execute the first working mode. In the case that the system oil temperature is greater than or equal to the preset oil temperature, the second target control instruction in the control instruction set is generated, and the first target control instruction is used to control the state control valve to execute the second working mode.

[0044] It should be noted that the first working mode is that the state control valve is in the right position, that is, the valve core of the state control valve blocks the high-pressure oil way, and the low-pressure oil way and the oil return way are connected. The second working mode is that the state control valve is in the left position, that is, the valve core of the state control valve is in the middle position, and the high-pressure oil way, the low-pressure oil way and the oil return way are not connected.

[0045] In step S4, in the target working mode, the speed of the oil pump motor is adjusted according to the current of the oil pump motor and the system oil pressure, including: the adjustment process of the speed of the oil pump motor when the state control valve is in the first working mode and the adjustment process of the speed of the oil pump motor when the state control valve is in the second working mode.

[0046] When the state control valve is in the first working mode, the adjustment step of the speed of the oil pump motor is as follows:

[0047] Step S411: The speed of the oil pump motor is adjusted to the first working speed, and it is judged whether the current of the oil pump motor exceeds the rated current of the oil pump motor. If not, the speed of the oil pump motor is adjusted to the second working speed, wherein the second working speed is greater than the first working speed.

[0048] Step S412: In the case that the speed of the oil pump motor is kept at the second working speed, it is judged whether the system oil pressure exceeds the allowable oil pressure. If not, the speed of the oil pump motor is adjusted to the third working speed, wherein the third working speed is greater than the second working speed.

[0049] Through step S411 and step S412, in this state, the system oil temperature is low, the oil viscosity is large, and the load is large, so the speed of the oil pump motor needs to be adjusted gradually to avoid the oil pump motor being burned out and the system oil pressure being out of limit due to the excessively high speed.

[0050] Further, in step S411, if the current of the oil pump motor exceeds the rated current of the oil pump motor while the speed of the oil pump motor is kept at the first working speed, the speed of the oil pump motor is adjusted to zero. It should be noted that if the current of the oil pump motor exceeds the rated current, it means that the oil pump motor will be burned out if it runs at the first working speed, and at this time, the first working speed is the lowest speed of the oil pump motor, and the oil pump motor cannot run normally at the lowest speed, which means that the oil pump motor may be faulty, and in order to avoid further damage, the oil pump motor needs to be turned off.

[0051] Further, in step S412, if the system oil pressure exceeds the allowable oil pressure while the speed of the oil pump motor is kept at the second working speed, the speed of the oil pump motor is adjusted to the first working speed. It should be noted that if the system oil pressure exceeds the allowable oil pressure, it means that the current speed of the oil pump motor is too fast, and needs to be reduced, so the speed of the oil pump motor is reduced to the first working speed.

[0052] When the state control valve is in the second working mode, the adjustment steps of the speed of the oil pump motor are as follows:

[0053] Step S42: In the case of the second working mode, the speed of the oil pump motor is adjusted to the second working speed, and it is judged whether the current of the oil pump motor exceeds the rated current of the oil pump motor. If not, it is continued to be judged whether the system oil pressure exceeds the allowable oil pressure, and if not, the speed of the oil pump motor is adjusted to the third working speed. It should be noted that in this state, the system oil temperature is high, the oil viscosity is small, and the system load is small, so the oil pump motor can have a large speed as the initial speed, and in order to protect the oil pump motor, the speed still needs to be adjusted gradually to avoid the oil pump motor being burned out and the system oil pressure being out of limit due to the excessively high speed.

[0054] Further, in the process of adjusting the speed of the oil pump motor, in order to ensure the stable operation of the oil pump motor, the following operations need to be performed, that is, after the speed of the oil pump motor is adjusted to the second working speed and maintained for a first preset time, the speed of the oil pump motor is adjusted to a fourth working speed and maintained for a second preset time, and then it is judged whether the system oil pressure exceeds the allowable oil pressure, and if not, the speed of the oil pump motor is adjusted to the third working speed, wherein the fourth working speed is greater than the second working speed and less than the third working speed. In this way, it is effectively ensured that the oil pump motor can start at low temperature.

[0055] In the above steps, the rotation speed of the oil pump motor is not instantaneously changed, and needs to be stabilized at a certain rotation speed before the next step of promotion is performed, so as to ensure the stable operation of the oil pump motor. Among them, the fourth working speed is used as the intermediate speed, so that the rotation speed of the oil pump motor is slowly adjusted, so as to further improve the stability of the operation of the oil pump motor.

[0056] Further, the oil pump motor adjusts the rotation speed of the oil pump motor by setting the speed-up slope. By adjusting the speed-up slope of the oil pump motor to adjust the rotation speed, the instant change of the rotation speed is avoided, so that the oil pump motor can stably operate.

[0057] Embodiment 3

[0058] In another embodiment of the present application, a specific control method for low-temperature starting of an automatic transmission electric oil pump system is provided, as shown in Figure 3 Figure 3 The motor in the above method is an oil pump motor, and the specific steps are as follows:

[0059] Step S01: The whole vehicle is powered on. Jump to step S02.

[0060] Step S02: The controller monitors the oil temperature signal of the system, and judges whether the system oil temperature is less than the preset oil temperature (OILTEMPmin), wherein OILTEMPmin=-30℃. If yes, jump to step S03. If no, jump to step S15.

[0061] Step S03: Set the working current of the state control valve as CURRENThigh, wherein CURRENThigh=1.0A. Ensure that the state control valve is located at the right position, and the low-pressure oil circuit and the return oil circuit are communicated, so as to reduce the starting load of the oil pump motor. Jump to step S04.

[0062] Step S04: Set the starting rotation speed of the oil pump motor as SPEEDmin, wherein SPEEDmin=100rpm. Jump to step S05.

[0063] Step S05: Judge whether the current of the oil pump motor is less than Ihighlimit, wherein Ihighlimit=40A. If yes, jump to step S06. If no, jump to step S07.

[0064] Step S06: Set the rotation speed of the oil pump motor as SPEEDinitial, wherein SPEEDinitial=1000rpm. Jump to step S08.

[0065] Step S07: Set the rotation speed of the oil pump motor as 0.

[0066] ​Step S08: Keep the oil pump motor speed for TIMEkeep seconds, where the speed at this time is SPEEDinitial, TIMEkeep = 5 s. Jump to step S09.

[0067] Step S09: Set the oil pump motor speed-up slope to SLOPErising, and set the oil pump motor speed to SPEEDlow, where SLOPErising = 100 rpm / 1 s, SPEEDlow = 2000 rpm. Jump to step S10.

[0068] Step S10: Keep the oil pump motor speed for TIMEkeep seconds, where the speed at this time is SPEEDlow, TIMEkeep = 5 s. Jump to step Sll.

[0069] Step Sll: Determine whether the system oil pressure is less than or equal to PRESSlow, where PRESSlow = 30 bar. If yes, jump to step S12. If no, jump to step S13.

[0070] Step S12: Set the oil pump motor speed-up slope to SLOPErising, and set the oil pump motor speed to SPEEDhigh, where SLOPErising = 100 rpm / 1 s, SPEEDhigh = 3000 rpm. Jump to step 14.

[0071] Step S13: Set the oil pump motor speed to SPEEDinitial.

[0072] Step S14: End.

[0073] Step S15: Set the state control valve operating current to CURRENTlow, where CURRENTlow = 0 A. Ensure that the state control valve is in the left position, and that the high pressure oil passage, the low pressure oil passage, and the return oil passage are not connected to each other. Jump to step S16.

[0074] Step S16: Set the oil pump motor start-up speed to SPEEDinitial, where SPEEDinitial = 1000 rpm. Jump to step S17.

[0075] Step S17: Determine whether the oil pump motor current is less than Ihighlimit, where Ihighlimit = 40 A. If yes, jump to step S06. If no, jump to step S18.

[0076] Step S18: Set the oil pump motor speed to 0.

[0077] Example 4

[0078] In another embodiment of the present application, a vehicle is also provided, comprising the automatic transmission electric oil pump system of the above-mentioned embodiments.

[0079] For purposes of the description hereinafter, spatial relative terms, such as "above", "below", "upper", "lower", and the like, can be used to describe the relative position of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "up" other elements or features would then be oriented "below" or "down" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0080] In addition to the above, it is to be noted that throughout the specification and claims, relative terms such as "one embodiment", "another embodiment", "an embodiment", etc. can be used. Such terms mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of the inventor(s) to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

[0081] In the above embodiments, the description of each embodiment is focused on a certain aspect, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0082] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low temperature start method for an automatic transmission electric oil pump system, characterized by, The automatic transmission electric oil pump system comprises: a low-pressure oil pump, which is communicated with a cooling system of a clutch through a low-pressure oil path; a high-pressure oil pump, which is communicated with an execution system of the clutch through a high-pressure oil path; a state control valve, which is connected with the low-pressure oil path and the high-pressure oil path respectively, and has a first state of conducting the low-pressure oil path and a return oil path, a second state of conducting the low-pressure oil path and the high-pressure oil path, and a third state of not conducting the low-pressure oil path, the high-pressure oil path and the return oil path; and an oil pump motor, whose driving end is connected with the low-pressure oil pump and the high-pressure oil pump respectively, and which is started to perform the following method: acquiring working parameters of the electric oil pump system, wherein the working parameters comprise system oil temperature, system oil pressure and current of the oil pump motor; comparing the system oil temperature with a preset oil temperature to obtain a comparison result; generating a control instruction set for controlling the state control valve to execute a target working mode in the case that the comparison result meets a preset condition, wherein the target working mode comprises a first working mode of conducting the low-pressure oil path and the return oil path, and a second working mode of not conducting the low-pressure oil path, the high-pressure oil path and the return oil path; adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure in the target working mode.

2. The low temperature starting method of claim 1, wherein, In the case that the comparison result meets the preset condition, generating the control instruction set comprises: generating a first target control instruction in the control instruction set for controlling the state control valve to execute the first working mode in the case that the system oil temperature is less than the preset oil temperature; generating a second target control instruction in the control instruction set for controlling the state control valve to execute the second working mode in the case that the system oil temperature is greater than or equal to the preset oil temperature.

3. The low temperature starting method of claim 1 wherein, In the target working mode, adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure comprises: adjusting the rotating speed of the oil pump motor to a first working rotating speed in the first working mode, and judging whether the current of the oil pump motor exceeds a rated current of the oil pump motor, and if not, adjusting the rotating speed of the oil pump motor to a second working rotating speed, wherein the second working rotating speed is greater than the first working rotating speed; judging whether the system oil pressure exceeds an allowable oil pressure in the case that the rotating speed of the oil pump motor is kept at the second working rotating speed, and if not, adjusting the rotating speed of the oil pump motor to a third working rotating speed, wherein the third working rotating speed is greater than the second working rotating speed.

4. The low temperature starting method of claim 3 wherein, In the target working mode, adjusting the rotating speed of the oil pump motor according to the current of the oil pump motor and the system oil pressure further comprises: If the current of the oil pump motor exceeds the rated current of the oil pump motor while the rotation speed of the oil pump motor is kept at the first working rotation speed, the rotation speed of the oil pump motor is adjusted to zero.

5. The low temperature starting method of claim 3 wherein, In the target working mode, the rotation speed of the oil pump motor is adjusted according to the current of the oil pump motor and the system oil pressure, and further comprising: If the system oil pressure exceeds the allowable oil pressure while the rotation speed of the oil pump motor is kept at the second working rotation speed, the rotation speed of the oil pump motor is adjusted to the first working rotation speed.

6. The low temperature starting method of claim 3 wherein, In the target working mode, the rotation speed of the oil pump motor is adjusted according to the current of the oil pump motor and the system oil pressure, and further comprising: In the second working mode, the rotation speed of the oil pump motor is adjusted to the second working rotation speed, and it is determined whether the current of the oil pump motor exceeds the rated current of the oil pump motor, if not, it is determined whether the system oil pressure exceeds the allowable oil pressure, if not, the rotation speed of the oil pump motor is adjusted to the third working rotation speed.

7. The low temperature starting method according to any one of claims 3 to 6, characterized in that, After the rotation speed of the oil pump motor is adjusted to the second working rotation speed and maintained for a first preset time, and then the rotation speed of the oil pump motor is adjusted to a fourth working rotation speed and maintained for a second preset time, it is determined whether the system oil pressure exceeds the allowable oil pressure, if not, the rotation speed of the oil pump motor is adjusted to the third working rotation speed, wherein the fourth working rotation speed is greater than the second working rotation speed and less than the third working rotation speed.

8. The low temperature starting method of claim 7 wherein, The rotation speed of the oil pump motor is adjusted by setting a speed-up slope.

9. An automatic transmission electric oil pump system characterized by comprising: The automatic transmission electric oil pump system is started by the low-temperature starting method in any one of claims 1 to 8, comprising: A state control valve, which is a three-position three-way electromagnetic valve, is provided with a first oil port, a second oil port and a third oil port, the first oil port is connected with a low-pressure oil circuit, the second oil port is connected with a high-pressure oil circuit, and the third oil port is connected with an oil pan.

10. A vehicle comprising an automatic transmission electric oil pump system, characterized by, The automatic transmission electric oil pump system is the automatic transmission electric oil pump system in claim 9. The automatic transmission electric oil pump system is the automatic transmission electric oil pump system in claim 9.

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