Hydraulic system of hybrid power transmission, series oil pump system control method and vehicle

Abstract

The invention provides a hydraulic system of a hybrid power transmission, a series oil pump system control method and a vehicle, and the hydraulic system of the hybrid power transmission comprises a main electric pump subsystem and an auxiliary electric pump subsystem; the main electric pump subsystem is connected with the auxiliary electric pump subsystem in series, when the hydraulic system needs low pressure, the main electric pump subsystem works independently, and when the hydraulic system needs high pressure, the main electric pump subsystem and the auxiliary electric pump subsystem work at the same time; and the auxiliary electric pump subsystem is used for increasing the oil pressure of the main electric pump subsystem. The efficiency of the transmission can be improved.

Description

Technical Field

[0001] The present application relates to the field of hydraulic systems, and in particular, to a hydraulic system of a hybrid transmission, a control method for a series oil pump system, and a vehicle. Background Art

[0002] Passenger car hybrid transmissions mostly use a combination of electric and hydraulic control. The efficiency of the hydraulic system is the main factor affecting the efficiency of the transmission. An important means to improve the efficiency of the transmission is to improve the efficiency of the hydraulic system.

[0003] Currently, the hydraulic system of the existing transmission will produce hydraulic redundancy, affecting the efficiency of the transmission. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a hydraulic system of a hybrid transmission, a control method for a series oil pump system, and a vehicle, so as to improve the efficiency of the hybrid transmission.

[0005] In a first aspect, the present invention provides a hydraulic system for a hybrid transmission, the hydraulic system comprising a main electric pump subsystem and an auxiliary electric pump subsystem;

[0006] The main electric pump subsystem is connected in series with the auxiliary electric pump subsystem, wherein when the hydraulic system requires low pressure, the main electric pump subsystem works alone, and when the hydraulic system requires high pressure, the main electric pump subsystem and the auxiliary electric pump subsystem work simultaneously, and the auxiliary electric pump subsystem is used to increase the oil pressure of the main electric pump subsystem.

[0007] The hydraulic system of the first aspect of the present application has an oil pump subsystem and the auxiliary electric pump subsystem connected in series, so that when the hydraulic system requires low pressure, the main electric pump subsystem can work alone to avoid hydraulic redundancy, thereby improving the efficiency of the hydraulic system, thereby improving the efficiency of the transmission by improving the efficiency of the hydraulic system. At the same time, when the hydraulic system requires high pressure, the present application can simultaneously work through the main electric pump subsystem and the auxiliary electric pump subsystem, so that the auxiliary electric pump subsystem increases the oil pressure of the main electric pump subsystem, thereby taking into account the demand for high hydraulic pressure.

[0008] In an optional embodiment, the main electric pump subsystem includes a main oil pump and a main oil pump motor, the main oil pump is connected to the main oil pump motor, and the main oil pump motor is used to drive the main oil pump;

[0009] The auxiliary electric pump subsystem includes an auxiliary oil pump and an auxiliary oil pump motor. The auxiliary oil pump is connected to the auxiliary oil pump motor, and the auxiliary oil pump motor is used to drive the auxiliary oil pump.

[0010] This optional implementation may be driven by the main oil pump motor, and on the other hand, the auxiliary oil pump may be driven by the auxiliary oil pump motor.

[0011] In an optional embodiment, the hydraulic system further includes an oil suction filter and an oil pan, and the main oil pump sucks oil from the oil pan through the oil suction filter and outputs high-pressure oil, wherein the output flow of the main oil pump is controlled based on the speed of the main oil pump motor.

[0012] This optional implementation can enable the main oil pump to suck oil from the oil pan through the oil suction filter and output high-pressure oil, and can control the output flow of the main oil pump based on the rotation speed of the main oil pump motor.

[0013] In an optional embodiment, the hydraulic system also includes a first reversing solenoid valve, a second reversing solenoid valve, a check valve, a high-level oil tank and a safety valve, wherein the high-pressure oil output by the main oil pump flows out in four ways, wherein the first oil way goes to the first reversing solenoid valve and the second reversing solenoid valve, the second oil way goes to the check valve, the third oil way goes to the high-level oil tank, and the fourth oil way goes to the safety valve.

[0014] This optional implementation can make the high-pressure oil output by the main oil pump flow to the first reversing solenoid valve, the second reversing solenoid valve, the check valve, the high-level oil tank and the safety valve.

[0015] In an optional embodiment, the first reversing solenoid valve is of a normally open type, wherein when the first reversing solenoid valve is not energized, oil flows directly through the first reversing solenoid valve to the inlet of the auxiliary oil pump.

[0016] In this optional implementation, when the first reversing solenoid valve is not energized, the oil can flow directly through the first reversing solenoid valve to the inlet of the auxiliary oil pump.

[0017] In an optional embodiment, the opening pressure of the check valve is a first preset pressure value, wherein when the pressure of the second oil line is greater than the first preset pressure value, the check valve opens, and the oil enters the second reversing solenoid valve, and the second reversing solenoid valve is normally open. When the second reversing solenoid valve is not energized, the oil flows directly through the second reversing solenoid valve to the actuator hydraulic cylinder of the hydraulic system.

[0018] In this optional implementation, when the pressure of the second oil line is greater than the first preset pressure value, the check valve is opened, and the oil enters the second reversing solenoid valve. On the other hand, when the second reversing solenoid valve is not energized, the oil directly flows through the second reversing solenoid valve to the actuator cylinder of the hydraulic system.

[0019] In an optional embodiment, the hydraulic system further comprises a throttle hole;

[0020] The high-position oil tank is used to store excess oil at the upper end of the transmission, and the oil is sprayed on the parts of the transmission that need lubrication and cooling through the multiple throttle holes.

[0021] This optional implementation can spray the oil through the throttle hole to the part of the transmission that needs lubrication and cooling. At the same time, the high-position oil tank can store excess oil at the upper end of the transmission, thereby lowering the liquid level at the lower part of the transmission, reducing the oil churning loss of the transmission gears, and thus improving the transmission efficiency.

[0022] In an optional embodiment, the opening pressure of the safety valve is a second preset pressure value, wherein when the pressure of the fourth oil line is greater than the second preset pressure value, the safety valve opens, and excess high-pressure oil automatically flows into the input end of the main oil pump to protect the pressure of the hydraulic system.

[0023] In this optional implementation, the safety valve can be opened when the pressure of the fourth oil line is greater than the second preset pressure value, so that excess high-pressure oil automatically flows into the input end of the main oil pump to protect the pressure of the hydraulic system.

[0024] In an optional embodiment, the hydraulic system further includes a pressure sensor, wherein the pressure sensor is used to detect the oil pressure entering the actuator hydraulic cylinder.

[0025] This optional implementation can detect the oil pressure entering the actuator hydraulic cylinder through a pressure sensor.

[0026] In a second aspect, the present invention provides a method for controlling a tandem oil pump system, the method being applied to a hydraulic system as described in any one of the aforementioned embodiments, the method comprising:

[0027] When the vehicle is detected to be powered on, the throttle signal is monitored;

[0028] When the throttle signal is equal to 0, the speed of the main oil pump motor is controlled to be set to a first preset speed, so that the hydraulic system is maintained in a low power consumption state;

[0029] When the throttle signal is greater than 0, the speed of the main oil pump motor is controlled to increase to a second preset speed so that the pressure and flow provided by the hydraulic system meet the transmission requirements;

[0030] When the vehicle is powered on and started, and when it is detected that the transmission has shifted gears or the clutch has executed an action, the auxiliary oil pump motor is controlled to start, so that the auxiliary oil pump increases the oil pressure of the main oil pump under the drive of the auxiliary oil pump motor.

[0031] The method of the second aspect of the present application, when the vehicle is powered on and the user does not step on the accelerator or when the vehicle is starting, only the main oil pump outputs oil, thereby maintaining the hydraulic system in a low power consumption state, thereby improving the efficiency of the transmission. On the other hand, after the vehicle is powered on and started, under conditions such as the transmission shifting or clutch execution, the auxiliary oil pump motor can be started so that the auxiliary oil pump, driven by the auxiliary oil pump motor, increases the oil pressure of the main oil pump.

[0032] In an optional embodiment, the method further comprises:

[0033] Calculate the difference between the required pressure and the pressure feedback from the pressure sensor;

[0034] Obtaining a first command speed of the auxiliary oil pump motor by looking up the table based on the difference;

[0035] Obtaining a second command speed of the auxiliary oil pump motor based on the oil temperature by looking up a table;

[0036] Obtaining a third command speed of the auxiliary oil pump motor based on a clutch speed table lookup;

[0037] Obtaining a fourth command speed of the auxiliary oil pump motor by looking up a table based on the current speed of the auxiliary oil pump motor;

[0038] The first command speed, the second command speed, the third command speed, and the fourth command speed are accumulated to obtain a final command speed of the auxiliary oil pump motor.

[0039] This optional implementation may accumulate the first command speed, the second command speed, the third command speed, and the fourth command speed to obtain a final command speed of the auxiliary oil pump motor.

[0040] In a third aspect, the present invention provides a vehicle, comprising a hydraulic system of a hybrid transmission as described in any one of the aforementioned embodiments.

[0041] Since the vehicle of the third aspect of the present application includes the hydraulic system of the first aspect, it has advantages such as high transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1is a schematic structural diagram of a hydraulic system of a hybrid transmission disclosed in an embodiment of the present application;

[0044] Figure 2 It is a flow chart of a control method of a series oil pump system disclosed in an embodiment of the present application.

[0045] Icons: actuator hydraulic cylinder 1, first check valve 2, auxiliary electric pump subsystem 3, auxiliary oil pump 31, auxiliary oil pump motor 32, first reversing solenoid valve 4, main electric pump subsystem 5, main oil pump 51, main oil pump motor 52, oil suction filter 6, oil pan 7, safety valve 8, second check valve 9, second reversing solenoid valve 10, pressure sensor 11, throttle hole 12, high-level oil tank 13. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0047] Embodiment 1

[0048] See also Figure 1 , Figure 1 Schematic diagram of the structure of the hydraulic system of the hybrid transmission disclosed in the embodiment of the present application. Figure 1 As described above, the pressure system includes a main electric pump subsystem 5 and an auxiliary electric pump subsystem 3.

[0049] Furthermore, the main electric pump subsystem 5 is connected in series with the auxiliary electric pump subsystem 3, wherein when the hydraulic system requires low pressure, the main electric pump subsystem 5 works alone, and when the hydraulic system requires high pressure, the main electric pump subsystem 5 and the auxiliary electric pump subsystem 3 work simultaneously, and the auxiliary electric pump subsystem 3 is used to increase the oil pressure of the main electric pump subsystem 5.

[0050] The hydraulic system of the embodiment of the present application has an oil pump subsystem and an auxiliary electric pump subsystem 3 connected in series, so that when the hydraulic system requires low pressure, the main electric pump subsystem 5 can work alone to avoid hydraulic redundancy, thereby improving the efficiency of the hydraulic system, thereby improving the efficiency of the transmission by improving the efficiency of the hydraulic system. At the same time, when the hydraulic system requires high pressure, the present application can work simultaneously with the main electric pump subsystem 5 and the auxiliary electric pump subsystem 3, so that the auxiliary electric pump subsystem 3 increases the oil pressure of the main electric pump subsystem 5, thereby taking into account the demand for high hydraulic pressure.

[0051] For the embodiment of the present application, compared with the prior art, the prior art realizes hydraulic supply through two parallel pump bodies, wherein the two parallel pump bodies can meet the high pressure and large flow requirements. However, when facing such working conditions as low pressure, the two parallel pump bodies of the prior art still work in parallel, that is, the two pump bodies work at the same time, and then still output high pressure and large flow oil under such working conditions as low pressure, but in fact, such working conditions as low pressure do not require high pressure and large flow, only low pressure flow is required, which leads to hydraulic redundancy. The existence of hydraulic redundancy further reduces the efficiency of the hydraulic system, and the efficiency of the hydraulic system leads to the reduction of the efficiency of the transmission. In comparison, the embodiment of the present application can make the main oil pump 51 work under such working conditions as high pressure and large flow, and improve the hydraulic pressure and flow through the auxiliary oil pump 31, so as to meet the demand of high pressure and large flow. On the other hand, when facing the demand of low pressure flow, only the main oil pump 51 works, and the auxiliary oil pump 31 does not work, thereby avoiding hydraulic redundancy, thereby improving the efficiency of the hydraulic system, and thus improving the efficiency of the transmission.

[0052] In the embodiment of the present application, the auxiliary oil pump 31 is started only when it is needed to assist the main oil pump 51, which can avoid the auxiliary oil pump 31 doing useless work. Therefore, this on-demand working mode of the auxiliary oil pump 31 can also improve the efficiency of the hydraulic system.

[0053] In the embodiment of the present application, the efficiency of the hydraulic system is usually expressed as a percentage of the energy output to the execution part to the total energy of the hydraulic system. Furthermore, when the energy output to the execution part is fixed, the smaller the total energy of the hydraulic system, the greater the efficiency of the hydraulic system. Furthermore, avoiding hydraulic redundancy can make the hydraulic system do useless work and provide a fixed amount of energy to the execution part with a smaller total energy. Therefore, by avoiding hydraulic redundancy, the efficiency of the hydraulic system can be improved.

[0054] In the embodiment of the present application, the hydraulic system is an important component of the vehicle transmission, wherein the efficiency of the transmission is positively correlated with the efficiency of the hydraulic system. When the efficiency of the hydraulic system is improved, the efficiency of the transmission is also improved accordingly.

[0055] In the embodiment of the present application, the main electric pump subsystem 5 and the auxiliary electric pump subsystem 3 are connected in series, which means that the main oil pump 51 in the main electric pump subsystem 5 is connected in series with the auxiliary oil pump 31 of the auxiliary electric pump subsystem 3, wherein the output port of the main oil pump 51 is connected to the oil pan 7 and oil is extracted therefrom, and the output port of the main oil pump 51 is connected to the reversing solenoid valve, and the oil flow direction can be changed by the reversing solenoid valve. For example, when the reversing solenoid valve is not energized, the oil flowing out of the output port of the main oil pump 51 flows into the input port of the auxiliary oil pump 31, and when the reversing solenoid valve is energized, the oil flowing out of the output port of the main oil pump 51 flows into the actuator hydraulic cylinder 1.

[0056] In the embodiment of the present application, as an optional implementation, Figure 1 As shown, the main electric pump subsystem 5 includes a main oil pump 51 and a main oil pump motor 52, the main oil pump 51 is connected to the main oil pump motor 52, and the main oil pump motor 52 is used to drive the main oil pump 51. Correspondingly, the auxiliary electric pump subsystem 3 includes an auxiliary oil pump 31 and an auxiliary oil pump motor 32, the auxiliary oil pump 31 is connected to the auxiliary oil pump motor 32, and the auxiliary oil pump motor 32 is used to drive the auxiliary oil pump 31. It can be seen that this optional embodiment can be driven by the main oil pump motor 52, and on the other hand, the auxiliary oil pump 31 can be driven by the auxiliary oil pump motor 32.

[0057] In the embodiment of the present application, the main oil pump 51 is used to output low pressure and large flow, and it adopts a large displacement pump. Accordingly, the rated power of the main oil pump motor 52 is high and the rated speed is low. Accordingly, the auxiliary oil pump 31 is designed as a small displacement pump, and the rated power of the auxiliary oil pump motor 32 is low and the rated speed is high. Furthermore, the main oil circuit characteristic is low pressure and large flow, and the execution oil circuit characteristic is high pressure and low flow.

[0058] In the embodiment of the present application, the rated power of the main oil pump motor 52 is high, which is conducive to low-temperature starting. The pressurized oil generated is directly connected to the inlet of the auxiliary oil pump 31, thereby avoiding the auxiliary oil pump 31 from sucking air during low-temperature starting, thereby ensuring the accuracy and reliability of the low-temperature transmission execution.

[0059] In the embodiment of the present application, as an optional implementation, Figure 1 As shown, the hydraulic system further includes an oil suction filter 6 and an oil pan 7, wherein the main oil pump 51 sucks oil from the oil pan 7 through the oil suction filter 6 and outputs high-pressure oil, wherein the output flow of the main oil pump 51 is controlled based on the rotation speed of the main oil pump motor 52. It can be seen that this optional embodiment can make the main oil pump 51 suck oil from the oil pan 7 through the oil suction filter 6 and output high-pressure oil, and can control the output flow of the main oil pump 51 based on the rotation speed of the main oil pump motor 52, for example, the output flow of the main oil pump 51 can be increased by increasing the rotation speed of the main oil pump motor 52.

[0060] In the embodiment of the present application, as an optional implementation, the hydraulic system further includes a first reversing solenoid valve 4, a second reversing solenoid valve 10, a check valve, a high-level oil tank 13 and a safety valve 8, wherein the high-pressure oil output by the main oil pump 51 flows out in four ways, wherein the first way of oil flows to the first reversing solenoid valve 4 and the second reversing solenoid valve 10, the second way of oil flows to the check valve, the third way of oil flows to the high-level oil tank 13, and the fourth way of oil flows to the safety valve 8. This optional implementation allows the high-pressure oil output by the main oil pump 51 to flow to the first reversing solenoid valve 4, the second reversing solenoid valve 10, the check valve, the high-level oil tank 13 and the safety valve 8.

[0061] In the embodiment of the present application, as an optional implementation, the first reversing solenoid valve 4 is a normally open type, wherein when the first reversing solenoid valve 4 is not energized, the oil flows directly through the first reversing solenoid valve 4 to the inlet of the auxiliary oil pump 31. In this optional implementation, when the first reversing solenoid valve 4 is not energized, the oil flows directly through the first reversing solenoid valve 4 to the inlet of the auxiliary oil pump 31.

[0062] In the embodiments of the present application, Figure 1 As shown, the check valve includes a first check valve 2 and a second check valve 9, which are used to prevent oil from flowing back.

[0063] In an optional embodiment, the opening pressure of the check valve is a first preset pressure value, wherein when the pressure of the second oil is greater than the first preset pressure value, the check valve opens, and the oil enters the second reversing solenoid valve 10, and the second reversing solenoid valve 10 is a normally open type. When the second reversing solenoid valve 10 is not energized, the oil flows directly through the second reversing solenoid valve 10 to the actuator cylinder 1 of the hydraulic system. This optional embodiment can open the check valve when the pressure of the second oil is greater than the first preset pressure value, and then the oil enters the second reversing solenoid valve 10. On the other hand, when the second reversing solenoid valve 10 is not energized, the oil can flow directly through the second reversing solenoid valve 10 to the actuator cylinder 1 of the hydraulic system.

[0064] With respect to the above optional implementation, the first preset pressure value may be 3 bar, for example, when the pressure of the second oil line is greater than 3 bar, the check valve opens and the oil enters the reversing solenoid valve.

[0065] In the embodiment of the present application, as an optional implementation, the hydraulic system further includes a throttle hole 12, and accordingly, the high-position oil tank 13 is used to store excess oil at the upper end of the transmission, and the oil is sprayed on the parts of the transmission that need lubrication and cooling through multiple throttle holes 12. This optional implementation can spray the oil on the parts of the transmission that need lubrication and cooling through the throttle holes 12. At the same time, the high-position oil tank 13 can store excess oil at the upper end of the transmission, thereby lowering the liquid level at the lower part of the transmission, reducing the oil stirring loss of the transmission gears, and thus improving the transmission efficiency.

[0066] Regarding the above optional implementation modes, the parts of the transmission that require lubrication and cooling can refer to the prior art, and the embodiments of the present application will not elaborate on this.

[0067] In an embodiment of the present application, as an optional implementation, the opening pressure of the safety valve 8 is a second preset pressure value, wherein when the pressure of the fourth oil line is greater than the second preset pressure value, the safety valve 8 opens, and excess high-pressure oil automatically flows into the input end of the main oil pump 51 to protect the pressure of the hydraulic system.

[0068] For the above optional implementation, the second preset pressure value can be 5 bar. For example, when the pressure of the four-way oil increases due to special reasons, when the pressure increases to 5 bar, the safety valve 8 opens, and the excess high-pressure oil automatically flows into the input end of the main oil pump 51 system, thereby protecting the system pressure.

[0069] In this optional implementation, the safety valve 8 can be opened when the pressure of the fourth oil line is greater than the second preset pressure value, so that the excess high-pressure oil automatically flows into the input end of the main oil pump 51 to protect the pressure of the hydraulic system. It should be noted that the pressure of the main oil pump 51 will not exceed the safety threshold of the safety valve 8, that is, it will not exceed the second preset pressure value.

[0070] In the embodiment of the present application, as an optional implementation, the hydraulic system further includes a pressure sensor 11 , wherein the pressure sensor 11 is used to detect the oil pressure entering the actuator hydraulic cylinder 1 .

[0071] This optional implementation can detect the oil pressure entering the actuator hydraulic cylinder 1 through the pressure sensor 11.

[0072] Embodiment 2

[0073] See also Figure 2 , Figure 2 is a flow chart of a control method for a series oil pump system disclosed in an embodiment of the present application, wherein the method is applied to a hydraulic system as in any one of the aforementioned embodiments. Figure 2 As shown, the method of the embodiment of the present application includes the following steps:

[0074] 101. When the vehicle is detected to be powered on, the throttle signal is monitored;

[0075] 102. When the throttle signal is equal to 0, the speed of the main oil pump motor is controlled to be set to a first preset speed so that the hydraulic system is maintained in a low power consumption state;

[0076] 103. When the throttle signal is greater than 0, the speed of the main oil pump motor is controlled to increase to a second preset speed so that the pressure and flow provided by the hydraulic system meet the transmission requirements;

[0077] 104. When the vehicle is powered on and started, and when it is detected that the transmission has shifted gears or the clutch has executed an action, the auxiliary oil pump motor is controlled to start, so that the auxiliary oil pump increases the oil pressure of the main oil pump under the drive of the auxiliary oil pump motor.

[0078] The method of the embodiment of the present application can only make the main oil pump 51 output oil when the vehicle is powered on and the user does not step on the accelerator or when the vehicle is starting, thereby maintaining the hydraulic system in a low power consumption state, thereby improving the efficiency of the transmission. On the other hand, after the vehicle is powered on and started, under conditions such as the transmission shifting or clutch execution, the auxiliary oil pump motor 32 can be started, so that the auxiliary oil pump 31, driven by the auxiliary oil pump motor 32, increases the oil pressure of the main oil pump 51.

[0079] According to the embodiment of the present application, the first preset rotation speed may be 1000 rpm, and the second preset rotation speed may be 2000 rpm.

[0080] In the embodiment of the present application, for step 104, generally speaking, when the vehicle is powered on and started, and the transmission has a gear shift or the clutch executes an action, at this time, the pressure requirement needs to be greater than 3 bar. Therefore, it can also be determined whether the auxiliary oil pump 31 needs to be started based on the pressure requirement, that is, when the pressure requirement is greater than or equal to 3 bar, the auxiliary oil pump 31 is started.

[0081] In the embodiment of the present application, as an optional implementation, the method of the embodiment of the present application further includes the following steps:

[0082] Calculate the difference between the required pressure and the pressure feedback from the pressure sensor 11;

[0083] Obtaining a first command speed of the auxiliary oil pump motor 32 based on the difference table lookup;

[0084] Obtaining a second command speed of the auxiliary oil pump motor 32 based on the oil temperature by looking up a table;

[0085] Obtaining a third command speed of the auxiliary oil pump motor 32 based on the clutch speed table lookup;

[0086] Obtaining a fourth command speed of the auxiliary oil pump motor 32 by looking up a table based on the current speed of the auxiliary oil pump motor 32 ;

[0087] The first command speed, the second command speed, the third command speed, and the fourth command speed are accumulated to obtain a final command speed of the auxiliary oil pump motor 32 .

[0088] This optional implementation may accumulate the first command speed, the second command speed, the third command speed, and the fourth command speed to obtain a final command speed of the auxiliary oil pump motor 32 .

[0089] In the above optional implementation manner, the required pressure refers to the pressure demand.

[0090] Embodiment 3

[0091] An embodiment of the present application provides a vehicle, the vehicle comprising a hydraulic system of a hybrid transmission as described in any one of the aforementioned embodiments.

[0092] Since the vehicle of the embodiment of the present application includes the hydraulic system of the first aspect, it has advantages such as high transmission efficiency of the variable speed device.

[0093] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0094] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0095] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0096] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM) random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0097] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0098] The above are only embodiments of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A hydraulic system for a hybrid transmission, characterized in that: The hydraulic system includes a main electric pump subsystem and an auxiliary electric pump subsystem; The main electric pump subsystem is connected in series with the auxiliary electric pump subsystem, wherein when the hydraulic system requires low pressure, the main electric pump subsystem works alone, and when the hydraulic system requires high pressure, the main electric pump subsystem and the auxiliary electric pump subsystem work simultaneously, and the auxiliary electric pump subsystem is used to increase the oil pressure of the main electric pump subsystem.

2. The hydraulic system according to claim 1, characterized in that: The main electric pump subsystem includes a main oil pump and a main oil pump motor, the main oil pump is connected to the main oil pump motor, and the main oil pump motor is used to drive the main oil pump; The auxiliary electric pump subsystem includes an auxiliary oil pump and an auxiliary oil pump motor. The auxiliary oil pump is connected to the auxiliary oil pump motor, and the auxiliary oil pump motor is used to drive the auxiliary oil pump.

3. The hydraulic system according to claim 2, characterized in that: The hydraulic system further includes an oil suction filter and an oil pan, the main oil pump sucks oil from the oil pan through the oil suction filter and outputs high-pressure oil, wherein the output flow of the main oil pump is controlled based on the rotation speed of the main oil pump motor.

4. The hydraulic system according to claim 3, characterized in that: The hydraulic system also includes a first reversing solenoid valve, a second reversing solenoid valve, a check valve, a high-level oil tank and a safety valve, wherein the high-pressure oil output by the main oil pump flows out in four ways, wherein the first way of oil goes to the first reversing solenoid valve and the second reversing solenoid valve, the second way of oil goes to the check valve, the third way of oil goes to the high-level oil tank, and the fourth way of oil goes to the safety valve.

5. The hydraulic system according to claim 4, characterized in that: The first reversing solenoid valve is of a normally open type, wherein when the first reversing solenoid valve is not energized, oil flows directly through the first reversing solenoid valve to the inlet of the auxiliary oil pump.

6. The hydraulic system according to claim 5, characterized in that: The opening pressure of the check valve is a first preset pressure value, wherein when the pressure of the second oil line is greater than the first preset pressure value, the check valve opens, and the oil enters the second reversing solenoid valve, and the second reversing solenoid valve is normally open. When the second reversing solenoid valve is not energized, the oil flows directly through the second reversing solenoid valve to the actuator hydraulic cylinder of the hydraulic system.

7. The hydraulic system according to claim 4, characterized in that: The hydraulic system also includes a throttle hole; The high-position oil tank is used to store excess oil at the upper end of the transmission, and the oil is sprayed on the parts of the transmission that need lubrication and cooling through the multiple throttle holes.

8. The hydraulic system according to claim 4, characterized in that: The opening pressure of the safety valve is a second preset pressure value, wherein when the pressure of the fourth oil line is greater than the second preset pressure value, the safety valve opens, and excess high-pressure oil automatically flows into the input end of the main oil pump to protect the pressure of the hydraulic system.

9. The hydraulic system according to claim 6, characterized in that: The hydraulic system further comprises a pressure sensor, wherein the pressure sensor is used to detect the oil pressure entering the actuator hydraulic cylinder.

10. A control method for a series oil pump system, characterized in that: The method is applied to the hydraulic system according to any one of claims 1 to 9, and the method comprises: When the vehicle is detected to be powered on, the throttle signal is monitored; When the throttle signal is equal to 0, the speed of the main oil pump motor is controlled to be set to a first preset speed, so that the hydraulic system is maintained in a low power consumption state; When the throttle signal is greater than 0, the speed of the main oil pump motor is controlled to increase to a second preset speed so that the pressure and flow provided by the hydraulic system meet the transmission requirements; When the vehicle is powered on and started, and when it is detected that the transmission has shifted gears or the clutch has executed an action, the auxiliary oil pump motor is controlled to start, so that the auxiliary oil pump increases the oil pressure of the main oil pump under the drive of the auxiliary oil pump motor.

11. The method according to claim 9, characterized in that The method further comprises: Calculate the difference between the required pressure and the pressure feedback from the pressure sensor; Obtaining a first command speed of the auxiliary oil pump motor by looking up the table based on the difference; Obtaining a second command speed of the auxiliary oil pump motor based on the oil temperature by looking up a table; Obtaining a third command speed of the auxiliary oil pump motor based on a clutch speed table lookup; Obtaining a fourth command speed of the auxiliary oil pump motor by looking up a table based on the current speed of the auxiliary oil pump motor; The first command speed, the second command speed, the third command speed, and the fourth command speed are accumulated to obtain a final command speed of the auxiliary oil pump motor.

12. A vehicle, characterized in that: The vehicle comprises a hydraulic system of a hybrid transmission as claimed in any one of claims 1-9.

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