Hydraulic control system of continuously variable transmission

Abstract

The utility model provides a hydraulic control system of a continuously variable transmission. An oil outlet of a first electromagnetic valve is connected with a gear clutch, and an oil outlet of a second electromagnetic valve is connected with a belt wheel clutch. An oil outlet of the main oil way control valve communicates with oil inlets of the first electromagnetic valve and the second electromagnetic valve. An oil outlet of the mechanical oil pump is respectively communicated with an oil inlet of the main oil way control valve, an oil inlet of the mechanical pump pressure regulating valve and an oil inlet of the main oil way pressure regulating valve, an oil outlet of the mechanical oil pump is communicated with an oil pan of the continuously variable transmission, and an oil outlet of the main oil way pressure regulating valve is communicated with a lubricating oil way through a secondary oil way of the hydraulic control system; the main oil way pressure regulating valve drives oil of the mechanical oil pump to be switched between a first oil supply state that the oil only flows to the main oil way control valve and a first lubricating state that the oil only flows to the lubricating oil way, and an oil inlet of the electronic pump control valve is communicated with an oil outlet of the electronic oil pump. And an oil outlet of the electronic pump control valve is respectively communicated with an oil inlet of the main oil way control valve and the lubricating oil way. High-efficiency and low-loss work of the transmission can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field related to transmission control, and particularly relates to a hydraulic control system of a continuously variable transmission. Background Art

[0002] Continuously variable transmission (CVT) technology uses a transmission belt and a main and driven wheel with variable working diameters to transmit power, which can achieve continuous changes in the transmission ratio and has the advantages of smooth shifting and low fuel consumption. The CVT in the prior art is generally connected by meshing a steel belt with the teeth of the driving wheel and the driven wheel, as in patent document CN220523196U. The power output by the engine output shaft is first transmitted to the driving wheel, then transmitted to the driven wheel through the steel belt, and finally transmitted to the wheel via the output shaft connected to the driven wheel to drive the car. In addition, the continuously variable speed change is achieved by continuously adjusting the working radius of the driving wheel and the driven wheel. The CVT mainly controls its working state through a hydraulic control system to achieve speed change. Therefore, the hydraulic control system of the CVT plays a key role in the working efficiency of the transmission.

[0003] However, in the existing hydraulic control system of the continuously variable transmission, since the continuously variable transmission requires a steel belt drive, it has the following disadvantages:

[0004] (1) The speed ratio of a continuously variable transmission needs to be adjusted by controlling the diameter of the transmission's active cylinder. However, due to the fixed size of the transmission, the speed ratio adjustment range is often relatively low.

[0005] (2) When starting at low speed, the steel belt speed ratio changes, which will generate large slip friction losses, which will lead to low transmission efficiency of the gearbox; and insufficient transmission ratio will further lead to slow response when starting at low speed;

[0006] (3) When the steel belt is working at a high speed ratio, it is subjected to greater stress, and in severe cases, there is a risk of slipping and breaking of the steel belt;

[0007] (4) Under high-speed conditions, since the oil pump of the transmission hydraulic control system is driven by the engine, the oil pump flow is large and the efficiency is low.

[0008] In summary, the hydraulic control system of the continuously variable transmission in the prior art cannot achieve high efficiency and low loss operation of the transmission. Utility Model Content

[0009] The utility model aims to solve the problem that the hydraulic control system of the continuously variable transmission in the prior art cannot realize the high-efficiency and low-loss operation of the transmission.

[0010] In order to solve the above technical problems, the utility model discloses a hydraulic control system of a continuously variable transmission, which includes a gear transmission assembly, a pulley transmission assembly, a gear clutch, and a pulley clutch. The hydraulic control system drives the gear clutch and the pulley clutch to switch between a first clutch state in which the gear clutch is disengaged and the pulley clutch is engaged, and a second clutch state in which the gear clutch is engaged and the pulley clutch is disengaged, so as to drive the continuously variable transmission to switch between a pulley drive mode in which the pulley transmission assembly transmits the power of the input shaft of the continuously variable transmission to the output shaft and a gear drive mode in which the gear transmission assembly transmits the power of the input shaft to the output shaft.

[0011] In addition, the hydraulic control system includes: a clutch control valve group, the clutch control valve group includes a first solenoid valve and a second solenoid valve, the first solenoid valve and the second solenoid valve are both arranged on the main oil circuit of the hydraulic control system, the oil outlet of the first solenoid valve is connected to the gear clutch, and the oil outlet of the second solenoid valve is connected to the pulley clutch; a main oil circuit control valve, the main oil circuit control valve is arranged on the main oil circuit, the oil outlet of the main oil circuit control valve is connected to the oil inlet of the first solenoid valve and the oil inlet of the second solenoid valve respectively; a first oil pump assembly, the first oil pump assembly includes a mechanical oil pump, a mechanical pump pressure regulating valve and a main oil circuit pressure regulating valve, the oil outlet of the mechanical oil pump is respectively connected to the oil inlet of the main oil circuit control valve The oil inlet of the mechanical pump pressure regulating valve and the oil inlet of the main oil circuit pressure regulating valve are connected, the oil outlet of the mechanical pump pressure regulating valve is connected to the oil pan of the continuously variable transmission, and the oil outlet of the main oil circuit pressure regulating valve is connected to the lubricating oil circuit via the secondary oil circuit of the hydraulic control system; the main oil circuit pressure regulating valve drives the oil of the mechanical oil pump to switch between a first oil supply state in which the oil flows only to the main oil circuit control valve and a first lubrication state in which the oil flows only to the lubricating oil circuit; a second oil pump assembly, the second oil pump assembly includes an electronic oil pump and an electronic pump control valve, the oil inlet of the electronic pump control valve is connected to the oil outlet of the electronic oil pump, and the oil outlet of the electronic pump control valve is respectively connected to the oil inlet of the main oil circuit control valve and the lubricating oil circuit.

[0012] Furthermore, when the continuously variable transmission is in the first clutch state, the first oil pump assembly is in the first oil supply state, and the second oil pump assembly is in the second lubrication state in which the oil outlet of the electronic pump control valve is connected only to the lubrication oil circuit; when the continuously variable transmission is in the second clutch state, the first oil pump assembly is in the first lubrication state, and the second oil pump assembly is in the second oil supply state in which the oil outlet of the electronic pump control valve is connected only to the oil inlet of the main oil circuit control valve.

[0013] By adopting the above scheme, the hydraulic control system can switch the clutch state of the continuously variable transmission between the pulley drive mode and the gear drive mode through the first oil pump assembly, the second oil pump assembly, the clutch control valve group and the main oil circuit control valve, and realize the high-efficiency operation of the transmission through the working condition switching. Moreover, in the pulley drive mode, the mechanical oil pump is used as the main pump source, and only a single oil port mechanical oil pump can be set to realize the oil supply, which can reduce oil consumption and also reduce the structural difficulty and layout cost of the system. In addition, the main oil circuit pressure regulating valve is connected to the lubricating oil circuit, which can actively adjust the lubrication flow, improve the working efficiency of the oil pump, and further reduce energy consumption.

[0014] According to another specific embodiment of the utility model, the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the hydraulic control system also includes a main oil circuit solenoid valve; the oil inlet of the main oil circuit solenoid valve is connected to the main oil circuit, and the oil outlet is connected to the spring control end of the main oil circuit pressure regulating valve. In addition, the mechanical pump pressure regulating valve and the main oil circuit pressure regulating valve are both comparison valves. Among them, the electromagnetic control end of the mechanical pump pressure regulating valve is connected to the oil outlet of the mechanical oil pump, and the spring control end is connected to the main oil circuit; the electromagnetic control end of the main oil circuit pressure regulating valve is connected to the oil outlet of the mechanical oil pump.

[0015] By adopting the above solution, the mechanical pump pressure regulating valve and the main oil circuit pressure regulating valve are both configured as comparison valves, which has a simpler structure and lower cost.

[0016] According to another specific embodiment of the utility model, the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the main oil circuit control valve includes a main oil circuit safety valve and a pressure reducing valve; the oil inlet of the main oil circuit safety valve is connected to the oil outlet of the mechanical oil pump, and the oil outlet is connected to the oil tank; the oil inlet of the pressure reducing valve is respectively connected to the oil outlet of the mechanical oil pump and the oil outlet of the electronic pump control valve, the first oil outlet of the pressure reducing valve is connected to the oil tank, and the second oil outlet of the pressure reducing valve is respectively connected to the oil inlet of the first solenoid valve and the oil inlet of the second solenoid valve; the electromagnetic control end of the main oil circuit safety valve is connected to the main oil circuit, and the spring control end is connected to the second oil outlet of the pressure reducing valve; the electromagnetic control end of the pressure reducing valve is connected to the main oil circuit, and the spring control end is connected to the second oil outlet of the pressure reducing valve.

[0017] By adopting the above solution and providing a pressure reducing valve, a stable input pressure can be provided for valve components such as the first solenoid valve and the second solenoid valve.

[0018] According to another specific embodiment of the utility model, in the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the electronic pump control valve includes an electronic pump pressure regulating valve and an electronic pump switching valve; the electronic pump pressure regulating valve is a comparison valve, and the oil inlet of the electronic pump pressure regulating valve is connected to the oil outlet of the electronic oil pump, and the oil outlet is connected to the oil tank; the electromagnetic control end of the electronic pump pressure regulating valve is connected to the oil outlet of the electronic oil pump, and the spring control end is connected to the oil outlet of the first solenoid valve; the oil inlet of the electronic pump switching valve is connected to the oil outlet of the electronic oil pump, the first oil outlet is connected to the oil inlet of the main oil circuit control valve, and the second oil outlet is connected to the lubrication oil circuit via the lubrication pipeline, and the electromagnetic control end of the electronic pump switching valve is connected to the oil outlet of the second solenoid valve.

[0019] By adopting the above scheme, by setting the electronic pump switching valve, the flow of the lubricating oil circuit can be supplemented by the electronic oil pump under working conditions such as high heating power. By setting the electronic pump pressure regulating valve, the outlet pressure of the electronic oil pump can be dynamically adjusted.

[0020] According to another specific embodiment of the utility model, the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the pulley transmission assembly includes a driving wheel, a driven wheel, a belt body sleeved on the driving wheel and the driven wheel, and an active oil cylinder and a driven oil cylinder respectively arranged on both sides of the driving wheel and the driven wheel along the rotation axis of the belt body. In addition, the hydraulic control system also includes an active oil cylinder control valve group and a driven oil cylinder control valve group. Among them, the active cylinder control valve group includes an active cylinder solenoid valve and an active cylinder pressure regulating valve; the oil inlet of the active cylinder solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder pressure regulating valve; the electromagnetic control end of the active cylinder solenoid valve is connected to the active cylinder pressure regulating valve; the oil inlet of the active cylinder pressure regulating valve is connected to the oil outlet of the mechanical oil pump, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder; the electromagnetic control end of the active cylinder pressure regulating valve is connected to the second oil outlet of the active cylinder solenoid valve, and the spring control end is connected to the oil circuit connecting the active cylinder pressure regulating valve and the active cylinder.

[0021] In addition, the slave cylinder control valve group includes a slave cylinder solenoid valve and a slave cylinder pressure regulating valve; the oil inlet of the slave cylinder solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the slave cylinder pressure regulating valve; the electromagnetic control end of the slave cylinder solenoid valve is connected to the slave cylinder pressure regulating valve; the oil inlet of the slave cylinder pressure regulating valve is respectively connected to the first oil outlet of the electronic pump switching valve and the oil outlet of the mechanical oil pump, the first oil outlet of the slave cylinder pressure regulating valve is connected to the oil tank, and the second oil outlet is connected to the slave cylinder; the electromagnetic control end of the slave cylinder pressure regulating valve is connected to the second oil outlet of the slave cylinder solenoid valve, and the spring control end is connected to the oil circuit connecting the slave cylinder pressure regulating valve and the slave cylinder.

[0022] By adopting the above solution, the active cylinder and the driven cylinder are controlled separately, which provides better flexibility.

[0023] According to another specific embodiment of the utility model, the hydraulic control system of a continuously variable transmission disclosed in the embodiment of the utility model, the continuously variable transmission also includes a parking clutch, a reverse clutch and a shift fork. And, the hydraulic control system includes a shift branch pressure regulating valve, a parking pressure regulating valve, a reverse pressure regulating valve and a shift fork pressure regulating valve. Among them, the shift branch pressure regulating valve is connected to the parking clutch, the reverse clutch and the shift fork via the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve respectively; and, the oil inlet of the shift branch pressure regulating valve is connected to the oil outlet of the mechanical oil pump and the first oil outlet of the electronic pump switching valve respectively, the first oil outlet of the shift branch pressure regulating valve is connected to the oil tank, and the second oil outlet is connected to the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve respectively; the electromagnetic control end of the shift branch pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve; the oil inlet of the parking pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet of the shift branch pressure regulating valve is connected to the oil tank, and the second oil outlet is connected to the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve respectively; the electromagnetic control end of the shift branch pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve; the oil inlet of the parking pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet of the shift branch pressure regulating valve is connected to the oil tank, and the second oil outlet of the shift branch pressure regulating valve is connected to the oil tank. An oil outlet is connected to the oil tank, and the second oil outlet is connected to the parking clutch; the spring control end of the parking pressure regulating valve is connected to the second oil outlet of the parking pressure regulating valve; the oil inlet of the reverse pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the reverse clutch; the spring control end of the reverse pressure regulating valve is connected to the second oil outlet of the reverse pressure regulating valve; the oil inlet of the shift fork pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet is connected to the oil tank, the second oil outlet is connected to one side cavity of the shift fork, and the third oil outlet is connected to the other side cavity of the shift fork.

[0024] By adopting the above scheme, the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve are all arranged in the corresponding oil circuits via the shift branch pressure regulating valve, which can share the overflow burden of the pressure reducing valve and connect the output oil of the shift branch pressure regulating valve to the oil pan to achieve forced pressure relief when the parking pressure regulating valve and the reverse pressure regulating valve are unexpectedly stuck.

[0025] According to another specific embodiment of the utility model, the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the hydraulic control system also includes a pulley safety valve arranged between the second solenoid valve and the pulley clutch; the oil inlet of the pulley safety valve is connected to the oil outlet of the second solenoid valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the pulley clutch; the electromagnetic control end of the pulley safety valve is connected to the second oil outlet of the parking pressure regulating valve; the oil inlet of the first solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the gear clutch; the spring control end of the first solenoid valve is connected to the second oil outlet of the first solenoid valve; the oil inlet of the second solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the pulley safety valve; the spring control end of the second solenoid valve is connected to the second oil outlet of the second solenoid valve.

[0026] By adopting the above scheme, the pulley safety valve can cut off the oil supply to the pulley clutch through the parking pressure regulating valve when the oil circuit pressure is abnormal, so as to perform forced pressure relief.

[0027] According to another specific embodiment of the utility model, the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the continuously variable transmission also includes a torque converter; the hydraulic control system also includes a torque converter switching valve, a torque converter pressure regulating valve and a torque converter solenoid valve. Among them, the torque converter switching valve is arranged on the secondary oil circuit, the first oil inlet of the torque converter switching valve is connected with the oil outlet of the main oil circuit pressure regulating valve, the second oil inlet is connected with the torque converter pressure regulating valve, the first oil outlet is connected with the oil tank, the second oil outlet is connected with the locking chamber of the torque converter, the third oil outlet is connected with the lubricating oil circuit, and the fourth oil outlet is connected with the unlocking chamber of the torque converter; the oil inlet of the torque converter pressure regulating valve is connected with the second oil outlet of the pressure reducing valve, the first oil outlet is connected with the second oil inlet of the torque converter switching valve, and the second oil outlet is connected with the oil tank; the oil inlet of the torque converter solenoid valve is connected with the second oil outlet of the pressure reducing valve, the first oil outlet is connected with the oil tank, and the second oil outlet is respectively connected with the electromagnetic control end of the torque converter switching valve and the electromagnetic control end of the torque converter pressure regulating valve.

[0028] According to another specific embodiment of the utility model, in the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the oil inlets of the main oil circuit solenoid valve, the torque converter solenoid valve, the torque converter pressure regulating valve, the slave cylinder solenoid valve, the active cylinder solenoid valve, the first solenoid valve and the second solenoid valve are all connected via the main oil circuit.

[0029] By adopting the above scheme, the oil inlets of the main oil circuit solenoid valve, the torque converter solenoid valve, the torque converter pressure regulating valve, the slave cylinder solenoid valve, the active cylinder solenoid valve, the first solenoid valve and the second solenoid valve are all connected via the main oil circuit, and their working states can be dynamically adjusted, thereby improving the reliability and stability of the system.

[0030] According to another specific embodiment of the utility model, in the hydraulic control system of the continuously variable transmission disclosed in the embodiment of the utility model, the gear clutch and the pulley clutch are both connected to the oil pan. In addition, an oil cooler, a pressure filter, and an oil injector are sequentially arranged in series on the lubricating oil circuit; the oil injector includes at least one outlet end, and at least one outlet end is respectively arranged near the gear transmission assembly, the pulley transmission assembly, the gear clutch, and the pulley clutch. In addition, the hydraulic control system also includes an oil pump drive assembly, and the oil pump drive assembly includes an engine connected to the mechanical oil pump, and a generator connected to the electronic oil pump.

[0031] With the above solution, the electronic oil pump is driven by a generator and is controlled independently of changes in engine speed, so the flow rate can be controlled more accurately, thereby reducing system fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of a continuously variable transmission provided by an embodiment of the utility model;

[0033] Figure 2 It is a schematic diagram of the continuously variable transmission provided by the embodiment of the utility model in the first clutch state;

[0034] Figure 3 It is a schematic diagram of the continuously variable transmission provided by the embodiment of the utility model in the second clutch state;

[0035] Figure 4 It is a structural schematic diagram of a hydraulic control system provided by an embodiment of the utility model;

[0036] Figure 5 It is another structural schematic diagram of the hydraulic control system provided by an embodiment of the utility model.

[0037] Description of reference numerals:

[0038] 11. Gear transmission assembly; 12. Pulley transmission assembly; 121. Driving wheel; 122. Driven wheel; 123. Belt body; 13. Gear clutch; 14. Pulley clutch; 15. Input shaft; 16. Output shaft; 17. Engine; 18. Oil pan; 19. Lubrication pipeline; 211. First solenoid valve; 212. Second solenoid valve; 213. Main oil circuit safety valve; 214. Pressure reducing valve; 215. Mechanical oil pump; 216. Mechanical pump pressure regulating valve; 217. Main oil circuit pressure regulating valve; 218. Electronic oil pump; 219. Electronic pump pressure regulating valve; 220. Electronic pump switching valve; 221. Active oil cylinder; 222. Driven oil cylinder; 223. Active oil cylinder solenoid valve; 224. Active oil cylinder pressure regulating valve Valve; 225, slave cylinder solenoid valve; 226, slave cylinder pressure regulating valve; 227, main oil circuit solenoid valve; 228, parking clutch; 229, reverse clutch; 230, shift fork; 231, shift branch pressure regulating valve; 232, parking pressure regulating valve; 233, reverse pressure regulating valve; 234, shift fork pressure regulating valve; 235, pulley safety valve; 236, torque converter; 237, torque converter switching valve; 238, torque converter pressure regulating valve; 239, torque converter solenoid valve; 240, oil cooler; 241, filter press; 242, fuel injector; 243, generator; 244, mechanical oil pump switch valve; 245, mechanical oil pump switch valve; A, main oil circuit; B, secondary oil circuit; C, lubricating oil circuit. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Embodiment 1:

[0041] As pointed out in the background technology, the prior art continuously variable transmission that is only driven by a steel belt cannot achieve high efficiency and low power consumption. In order to solve the above problems in the prior art, the utility model provides a hydraulic control system for a continuously variable transmission, wherein the continuously variable transmission controlled by the hydraulic control system has a pulley drive mode of a steel belt drive and a gear drive mode of a gear drive, and the hydraulic control system can control the continuously variable transmission to switch between the two drive modes, thereby achieving high efficiency and low power consumption of the continuously variable transmission.

[0042] First, refer to Figure 1-Figure 3 The continuously variable transmission will be described.

[0043] refer to Figure 1 The continuously variable transmission includes a gear transmission assembly 11, a pulley transmission assembly 12, a gear clutch 13, and a pulley clutch 14. The hydraulic control system drives the gear clutch 13 and the pulley clutch 14 to Figure 2The first clutch state in which the gear clutch 13 is disengaged and the pulley clutch 14 is engaged is shown. Figure 3 The gear clutch 13 shown is switched between the second clutch state in which the pulley clutch 14 is disconnected to drive the continuously variable transmission in Figure 2 The pulley drive assembly 12 shown transmits the power of the input shaft 15 of the continuously variable transmission to the pulley drive mode of the output shaft 16. Figure 3 The gear transmission assembly 11 shown switches between gear drive modes for transmitting power of the input shaft 15 to the output shaft 16. The engine 17 is fixedly connected to the pulley transmission assembly 12 to output its power via the input shaft 15.

[0044] Specifically, the gear clutch 13 is used to control the transmission power transmission path from the input shaft 15 through the gear transmission assembly 11 to the output shaft 16; the pulley clutch 14 is used to control the transmission power transmission path from the input shaft 15 through the pulley transmission assembly 12 to the output shaft 16. Figure 2 When the gear clutch 13 is disengaged and the pulley clutch 14 is engaged, the power transmission path of the transmission is shown as a thick solid line, and the power input through the input shaft 15 is transmitted to the output shaft 16 by the pulley transmission assembly 12. Figure 3 When the gear clutch 13 is engaged and the pulley clutch 14 is disengaged, the power transmission path of the transmission is as shown by the thick solid line, and the power input through the input shaft 15 is transmitted to the output shaft 16 by the gear transmission assembly 11. The states of the gear clutch 13 and the pulley clutch 14 are controlled by the hydraulic control system.

[0045] With such a structure, the hydraulic control system can control the continuously variable transmission to transmit power through the gear transmission assembly 11 in the low-speed starting condition, thereby improving the transmission efficiency and increasing the transmission ratio to achieve a quick start. In addition, in the medium and high speed stage, the pulley transmission assembly 12 is used to transmit power to meet the requirements of smoothness. The high-efficiency operation of the transmission can be achieved through the above-mentioned working condition switching.

[0046] Further, refer to Figure 4 This hydraulic control system will be described.

[0047] Specifically, the hydraulic control system includes a clutch control valve group, a main oil circuit control valve, a first oil pump assembly and a second oil pump assembly. The clutch control valve group is used to control Figure 1 The engagement state of the middle gear clutch 13 and the pulley clutch 14. The main oil circuit control valve is used to control the oil intake of the clutch control valve group. The first oil pump assembly and the second oil pump assembly are both used for oil supply.

[0048] Furthermore, the clutch control valve group includes a first solenoid valve 211 and a second solenoid valve 212. The first solenoid valve 211 and the second solenoid valve 212 are both arranged on the main oil circuit A of the hydraulic control system, the oil outlet of the first solenoid valve 211 is connected to the gear clutch 13, and the oil outlet of the second solenoid valve 212 is connected to the pulley clutch 14.

[0049] Main oil circuit control valve (including Figure 4 The main oil circuit safety valve 213 and the pressure reducing valve 214 shown are arranged on the main oil circuit A, and the oil outlet of the main oil circuit control valve is connected to the oil inlet of the first solenoid valve 211 and the oil inlet of the second solenoid valve 212 respectively.

[0050] The first oil pump assembly includes a mechanical oil pump 215, a mechanical pump pressure regulating valve 216 and a main oil circuit pressure regulating valve 217. The oil outlet of the mechanical oil pump 215 is respectively connected to the oil inlet of the main oil circuit control valve, the oil inlet of the mechanical pump pressure regulating valve 216 and the oil inlet of the main oil circuit pressure regulating valve 217. The oil outlet of the mechanical pump pressure regulating valve 216 is connected to the oil pan 18 of the continuously variable transmission, and the oil outlet of the main oil circuit pressure regulating valve 217 is connected to the lubricating oil circuit C via the secondary oil circuit B of the hydraulic control system. The main oil circuit pressure regulating valve 217 drives the oil of the mechanical oil pump 215 to switch between the first oil supply state in which the oil flows only to the main oil circuit control valve and the first lubrication state in which the oil flows only to the lubricating oil circuit C.

[0051] The second oil pump assembly includes an electronic oil pump 218 and an electronic pump control valve (including Figure 4 The electronic pump pressure regulating valve 219 and the electronic pump switching valve 220 are shown. The oil inlet of the electronic pump control valve is connected to the oil outlet of the electronic oil pump 218, and the oil outlet of the electronic pump control valve is connected to the oil inlet of the main oil circuit control valve and the lubricating oil circuit C respectively.

[0052] Moreover, when the continuously variable transmission is in the first clutch state, the first oil pump assembly is in the first oil supply state, and the second oil pump assembly is in the second lubrication state in which the oil outlet of the electronic pump control valve is only connected to the lubricating oil circuit C. That is, in the pulley driving state, the main oil supply work is completed by the mechanical oil pump 215, and the electronic oil pump 218 only performs lubrication at this time. When the continuously variable transmission is in the second clutch state, the first oil pump assembly is in the first lubrication state, and the second oil pump assembly is in the second oil supply state in which the oil outlet of the electronic pump control valve is only connected to the oil inlet of the main oil circuit control valve. That is, in the gear driving state, the oil supply work is completed by the electronic oil pump 218, and the mechanical oil pump 215 provides basic lubrication. Through such a structure, in the first clutch state of pulley driving, the electronic oil pump 218 only participates in basic lubrication, the mechanical oil pump 215 is the main pump source, and only one mechanical oil pump 215 is set, which can improve the working efficiency of the mechanical oil pump 215 and reduce fuel consumption. In the second clutch state of the gear drive, the electronic oil pump 218 is used as the main pump source. The electronic oil pump 218 can achieve precise oil volume control and improve the control accuracy of the system.

[0053] Furthermore, the hydraulic control system further includes a main oil circuit solenoid valve 227 . The oil inlet of the main oil circuit solenoid valve 227 is communicated with the main oil circuit A, and the oil outlet is communicated with the spring control end of the main oil circuit pressure regulating valve 217 .

[0054] In addition, the mechanical pump pressure regulating valve 216 and the main oil circuit pressure regulating valve 217 are both comparison valves. The electromagnetic control end of the mechanical pump pressure regulating valve 216 is connected to the oil outlet of the mechanical oil pump 215, and the spring control end is connected to the main oil circuit A. The electromagnetic control end of the main oil circuit pressure regulating valve 217 is connected to the oil outlet of the mechanical oil pump 215. The comparison valve has the advantages of simple structure and low cost. By setting the mechanical pump pressure regulating valve 216 and the main oil circuit pressure regulating valve 217 as comparison valves, the cost and difficulty of system layout can be further reduced.

[0055] In addition, in the pulley drive mode, the present embodiment uses the mechanical oil pump 215 as the main pump source, and the mechanical oil pump 215 with only a single oil port can realize oil supply, which can reduce oil consumption and reduce the structural difficulty and layout cost of the system. In addition, the main oil circuit pressure regulating valve 217 is connected to the lubricating oil circuit C, which can actively adjust the lubrication flow, improve the working efficiency of the mechanical oil pump 215, and further reduce energy consumption.

[0056] Specifically, the working state switching of the main oil circuit pressure regulating valve 217 is controlled by the output pressure of the oil outlet of the main oil circuit solenoid valve 227, the spring force of the spring control end and the pressure of the main oil circuit A. When the main oil circuit pressure regulating valve 217 is in the first working state, its oil inlet is isolated from the oil outlet; when it is in the second working state, the oil inlet is connected to the oil outlet.

[0057] When the pressure of the main oil circuit A is lower than the preset pressure, the oil outlet pressure of the main oil circuit solenoid valve 227 is adjusted to switch the main oil circuit pressure regulating valve 217 to the first working state, so that all the hydraulic oil from the mechanical oil pump 215 flows to the main oil circuit A for oil supply. When the pressure of the main oil circuit A is higher than the preset pressure, the oil outlet pressure of the main oil circuit solenoid valve 227 is adjusted to switch the main oil circuit pressure regulating valve 217 to the second working state, and all the hydraulic oil from the mechanical oil pump 215 flows to the secondary oil circuit B for lubrication.

[0058] Furthermore, the working state of the mechanical pump pressure regulating valve 216 is controlled by the oil outlet pressure of the mechanical oil pump 215, the spring force of the spring control end, and the pressure of the main oil circuit A. When the mechanical pump pressure regulating valve 216 is in the first working state, its oil inlet is isolated from the oil outlet; when it is in the second working state, its oil inlet is connected to the oil outlet.

[0059] When the output pressure of the mechanical oil pump 215 is too high, the mechanical pump pressure regulating valve 216 is in the second working state, and the oil output by the mechanical oil pump 215 returns to the input end of the mechanical oil pump 215 through the mechanical pump pressure regulating valve 216. When the output pressure of the mechanical oil pump 215 is too low, so that the pressure of the main oil circuit A is lower than the preset pressure, the mechanical pump pressure regulating valve 216 is adjusted to the first working state, so that all the hydraulic oil from the mechanical oil pump 215 flows to the main oil circuit A for oil supply.

[0060] Further, the main oil circuit control valve includes a main oil circuit safety valve 213 and a pressure reducing valve 214. Among them, the oil inlet of the main oil circuit safety valve 213 is connected to the oil outlet of the mechanical oil pump 215, and the oil outlet is connected to the oil tank. The oil inlet of the pressure reducing valve 214 is respectively connected to the oil outlet of the mechanical oil pump 215 and the oil outlet of the electronic pump control valve, the first oil outlet of the pressure reducing valve 214 is connected to the oil tank, and the second oil outlet of the pressure reducing valve 214 is respectively connected to the oil inlet of the first solenoid valve 211 and the oil inlet of the second solenoid valve 212. The electromagnetic control end of the main oil circuit safety valve 213 is connected to the main oil circuit A, and the spring control end is connected to the second oil outlet of the pressure reducing valve 214. The electromagnetic control end of the pressure reducing valve 214 is connected to the main oil circuit A, and the spring control end is connected to the second oil outlet of the pressure reducing valve 214.

[0061] Specifically, the working state of the main oil circuit safety valve 213 is jointly determined by the oil outlet pressure of the mechanical oil pump 215, the oil outlet pressure of the electronic pump control valve, the oil circuit pressure corresponding to the oil inlet of the first solenoid valve 211 and the second solenoid valve 212, and the spring force of the spring control end. When the pressure difference between the oil outlet pressure of the mechanical oil pump 215 or the electronic pump control valve and the oil circuit pressure corresponding to the oil inlet of the first solenoid valve 211 and the second solenoid valve 212 is less than the spring force, the system is normal, and the oil inlet and the oil outlet of the main oil circuit safety valve 213 are isolated. When the system fails, at this time, the pressure difference between the oil outlet pressure of the mechanical oil pump 215 or the electronic pump control valve and the oil circuit pressure corresponding to the oil inlet of the first solenoid valve 211 and the second solenoid valve 212 is greater than the spring force, and the oil inlet and the oil outlet of the main oil circuit safety valve 213 are connected to release pressure to ensure the stability of system pressure.

[0062] Furthermore, the pressure reducing valve 214 can adjust the oil circuit pressure corresponding to the oil inlet of the first solenoid valve 211 and the second solenoid valve 212 to a preset value. When the oil circuit pressure is lower than the preset pressure, the pressure reducing valve 214 switches to the first working state so that the oil inlet is connected to the second oil outlet; when the oil circuit pressure is higher than the preset pressure, the pressure reducing valve 214 switches to the second working state, the second oil outlet is connected to the third oil outlet, so that the branch is connected to the oil tank for pressure relief.

[0063] With the above structure, by setting the pressure reducing valve 214, a stable input pressure can be provided for the first solenoid valve 211, the second solenoid valve 212 and other valve bodies connected to the oil circuit, thereby ensuring the reliability of system operation.

[0064] Furthermore, the electronic pump control valve includes an electronic pump pressure regulating valve 219 and an electronic pump switching valve 220 . The electronic pump pressure regulating valve 219 is used to adjust the oil inlet pressure of the electronic pump switching valve 220 .

[0065] Specifically, the electronic pump pressure regulating valve 219 is a comparison valve, and the oil inlet of the electronic pump pressure regulating valve 219 is connected to the oil outlet of the electronic oil pump 218, and the oil outlet is connected to the oil tank. The electromagnetic control end of the electronic pump pressure regulating valve 219 is connected to the oil outlet of the electronic oil pump 218, and the spring control end is connected to the oil outlet of the first electromagnetic valve 211. Under normal conditions, the oil inlet and oil outlet of the electronic pump pressure regulating valve 219 are isolated. Setting the electronic pump pressure regulating valve 219 as a comparison valve has the advantages of simple structure and low cost. By setting the electronic pump pressure regulating valve 219, dynamic adjustment of the oil pressure at the oil outlet of the electronic oil pump 218 can be achieved.

[0066] In addition, the oil inlet of the electronic pump switching valve 220 is connected to the oil outlet of the electronic oil pump 218, the first oil outlet is connected to the oil inlet of the main oil circuit control valve, and the second oil outlet is connected to the lubrication oil circuit C via the lubrication pipeline 19, and the electromagnetic control end of the electronic pump switching valve 220 is connected to the oil outlet of the second solenoid valve 212.

[0067] With such a structure, when the continuously variable transmission is in the gear drive mode, the pulley clutch 14 is disconnected, the second solenoid valve 212 is switched to the first working state, the elastic force of the spring control end of the electronic pump switching valve 220 is greater than the pressure fed back by the second solenoid valve 212, and the electronic pump switching valve 220 is switched to the first working state. At this time, the electronic oil pump 218 is the gear clutch.

[0068] The electronic oil pump 218 provides control pressure to the gear clutch 13, and feeds back the output pressure of the gear clutch 13 to the electronic pump pressure regulating valve 219, so that the output pressure of the electronic oil pump 218 meets the pressure requirement of the gear clutch 13. At this time, the pressure of the main oil circuit A can be adjusted to the minimum to reduce the load of the mechanical oil pump 215, thereby reducing fuel consumption.

[0069] When the continuously variable transmission is in the pulley drive mode, the mechanical oil pump 215 provides high-pressure oil to control the oil pressure of the corresponding actuator. At this time, the pressure of the pulley clutch 14 is fed back to the electronic pump switching valve 220, and the electronic pump switching valve 220 switches to the second working state, switching the flow of the electronic oil pump 218 to the lubrication pipeline 19, and at the same time, the output flow of the electronic oil pump 218 can be adjusted according to the flow demand of cooling lubrication. In addition, the setting of the electronic pump switching valve 220 can connect the outlet of the electronic oil pump 218 with the lubrication oil circuit C after the pulley clutch 14 enters the pulley drive mode. Under working conditions such as large heating power, the oil volume of the lubrication oil circuit C is replenished by the electronic oil pump 218 to ensure the lubrication effect.

[0070] Further, refer to Figure 1 The pulley transmission assembly 12 includes a driving wheel 121, a driven wheel 122, a belt body 123 sleeved on the driving wheel 121 and the driven wheel 122, and Figure 4 As shown, a driving cylinder 221 and a driven cylinder 222 are respectively arranged on both sides of the driving wheel 121 and the driven wheel 122 along the rotation axis of the belt body 123.

[0071] In addition, the hydraulic control system further includes an active cylinder control valve group and a slave cylinder control valve group. Among them, the active cylinder control valve group includes an active cylinder solenoid valve 223 and an active cylinder pressure regulating valve 224. The oil inlet of the active cylinder solenoid valve 223 is connected to the second oil outlet of the pressure reducing valve 214, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder pressure regulating valve 224. The electromagnetic control end of the active cylinder solenoid valve 223 is connected to the active cylinder pressure regulating valve 224. The oil inlet of the active cylinder pressure regulating valve 224 is connected to the oil outlet of the mechanical oil pump 215, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder 221. The electromagnetic control end of the active cylinder pressure regulating valve 224 is connected to the second oil outlet of the active cylinder solenoid valve 223, and the spring control end is connected to the oil circuit connecting the active cylinder pressure regulating valve 224 and the active cylinder 221.

[0072] Specifically, the working state switching of the active cylinder pressure regulating valve 224 is controlled by the output pressure of the second oil outlet of the active cylinder solenoid valve 223, the spring force of the spring control end and the feedback pressure of the active cylinder 221. When the active cylinder pressure regulating valve 224 is in the first working state, the oil inlet is connected to the second oil outlet; when it is in the second working state, the first oil outlet is connected to the second oil outlet. Thus, the pressure of the active cylinder 221 can be controlled by the active cylinder solenoid valve 223 and the active cylinder pressure regulating valve 224. When the pressure of the active cylinder pressure regulating valve 224 is lower than the target pressure, the valve controller can adjust the output pressure of the second oil outlet of the active cylinder solenoid valve 223, so that the active cylinder pressure regulating valve 224 switches to the second working state, at which time the active cylinder 221 is connected to the main oil circuit A until the pressure of the active cylinder 221 reaches the target pressure. When the pressure of the active cylinder 221 is higher than the target pressure, the valve controller can adjust the output pressure of the second oil outlet of the active cylinder solenoid valve 223, so that the active cylinder pressure regulating valve 224 switches to the second working state. At this time, the active cylinder 221 and the oil tank are connected to reduce the pressure of the active cylinder 221 until the pressure of the active cylinder 221 reaches the target.

[0073] In addition, the slave cylinder control valve group includes a slave cylinder solenoid valve 225 and a slave cylinder pressure regulating valve 226. The oil inlet of the slave cylinder solenoid valve 225 is connected to the second oil outlet of the pressure reducing valve 214, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the slave cylinder pressure regulating valve 226. The electromagnetic control end of the slave cylinder solenoid valve 225 is connected to the slave cylinder pressure regulating valve 226. The oil inlet of the slave cylinder pressure regulating valve 226 is respectively connected to the first oil outlet of the electronic pump switching valve 220 and the oil outlet of the mechanical oil pump 215, the first oil outlet of the slave cylinder pressure regulating valve 226 is connected to the oil tank, and the second oil outlet is connected to the slave cylinder 222. The electromagnetic control end of the slave cylinder pressure regulating valve 226 is connected to the second oil outlet of the slave cylinder solenoid valve 225, and the spring control end is connected to the oil circuit connecting the slave cylinder pressure regulating valve 226 and the slave cylinder 222.

[0074] Specifically, the working state switching of the slave cylinder pressure regulating valve 226 is controlled by the output pressure of the second oil outlet of the slave cylinder solenoid valve 225, the spring force of the spring control end, and the feedback pressure of the slave cylinder 222. When the slave cylinder pressure regulating valve 226 is in the first working state, the oil inlet is connected to the second oil outlet; when it is in the second working state, the first oil outlet is connected to the second oil outlet. When the pressure of the slave cylinder 222 is lower than the target pressure, the valve controller adjusts the output pressure of the second oil outlet of the slave cylinder solenoid valve 225 to switch the slave cylinder solenoid valve 225 to the first working state, at which time the slave cylinder 222 is connected to the main oil circuit A until the pressure of the slave cylinder 222 reaches the target. When the pressure of the slave cylinder 222 is higher than the target pressure, the valve controller adjusts the output pressure of the second oil outlet of the slave cylinder solenoid valve 225 to switch the slave cylinder solenoid valve 225 to the second working state. At this time, the slave cylinder 222 is connected to the oil tank to reduce the pressure of the slave cylinder 222 until the pressure of the slave cylinder 222 reaches the target.

[0075] With the above structure, the oil inlet pressures of the active oil cylinder 221 and the slave oil cylinder 222 are controlled respectively by the active oil cylinder control valve group and the slave oil cylinder control valve group, which has higher flexibility.

[0076] Furthermore, the continuously variable transmission also includes a parking clutch 228, a reverse clutch 229 and a shift fork 230. In addition, the hydraulic control system includes a shift branch pressure regulating valve 231, a parking pressure regulating valve 232, a reverse pressure regulating valve 233 and a shift fork pressure regulating valve 234. The shift branch pressure regulating valve 231 is connected to the parking clutch 228, the reverse clutch 229 and the shift fork 230 via the parking pressure regulating valve 232, the reverse pressure regulating valve 233 and the shift fork pressure regulating valve 234.

[0077] In addition, the oil inlet of the shift branch pressure regulating valve 231 is respectively connected to the oil outlet of the mechanical oil pump 215 and the first oil outlet of the electronic pump switching valve 220, the first oil outlet of the shift branch pressure regulating valve 231 is connected to the oil tank, and the second oil outlet is respectively connected to the parking pressure regulating valve 232, the reverse pressure regulating valve 233 and the shift fork pressure regulating valve 234. The electromagnetic control end of the shift branch pressure regulating valve 231 is connected to the second oil outlet of the shift branch pressure regulating valve 231.

[0078] Specifically, the shift branch pressure regulating valve 231 is a solenoid valve. By adjusting the oil outlet pressure of the shift branch pressure regulating valve 231, a stable input pressure can be provided for the subsequent parking pressure regulating valve 232, the reverse pressure regulating valve 233, and the shift fork pressure regulating valve 234. In addition, the pressure of the rear-end actuator can be switched when the oil circuit pressure is abnormal.

[0079] When the shift branch pressure regulating valve 231 is in the first working state, the oil inlet and the second oil outlet are communicated; when the shift branch pressure regulating valve 231 is in the second working state, the first oil outlet and the second oil outlet are communicated.

[0080] The oil inlet of the parking pressure regulating valve 232 is connected to the second oil outlet of the shift branch pressure regulating valve 231, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the parking clutch 228. The spring control end of the parking pressure regulating valve 232 is connected to the second oil outlet of the parking pressure regulating valve 232.

[0081] Specifically, the parking pressure regulating valve 232 is a solenoid valve. When the parking pressure regulating valve 232 is in the first working state, the first oil outlet is connected to the second oil outlet; when it is in the second working state, the oil inlet is connected to the second oil outlet. Thus, the working state of the parking pressure regulating valve 232 can be switched and parking can be performed by adjusting the pressure of the solenoid control end of the parking pressure regulating valve 232.

[0082] The oil inlet of the reverse pressure regulating valve 233 is connected to the second oil outlet of the shift branch pressure regulating valve 231, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the reverse clutch 229. The spring control end of the reverse pressure regulating valve 233 is connected to the second oil outlet of the reverse pressure regulating valve 233.

[0083] Specifically, the reverse pressure regulating valve 233 is a solenoid valve. When the reverse pressure regulating valve 233 is in the first working state, the first oil outlet is connected to the second oil outlet; when it is in the second working state, the oil inlet is connected to the second oil outlet. When it is necessary to reverse, the output pressure of the shift branch pressure regulating valve 231 and the second oil outlet of the reverse pressure regulating valve 233 is adjusted to switch the shift branch pressure regulating valve 231 to the first working state, and the reverse pressure regulating valve 233 to the second working state, so that the reverse clutch 229 is in a coupled state.

[0084] The oil inlet of the shift fork pressure regulating valve 234 is connected to the second oil outlet of the shift branch pressure regulating valve 231, the first oil outlet is connected to the oil tank, the second oil outlet is connected to one side cavity of the shift fork 230, and the third oil outlet is connected to the other side cavity of the shift fork 230.

[0085] Specifically, the shift fork pressure regulating valve 234 is a solenoid valve, which is used to switch the engagement state of the shift fork 230. When the shift fork pressure regulating valve 234 is in the first working state, the oil inlet of the shift fork pressure regulating valve 234 is connected to the second oil outlet, and the first oil outlet is connected to the third oil outlet; when it is in the second working state, the oil inlet of the shift fork pressure regulating valve 234 is connected to the third oil outlet, and the first oil outlet is connected to the second oil outlet. By setting the shift fork pressure regulating valve 234, the gear position of the gear transmission assembly 11 of the continuously variable transmission can be switched. The gear transmission assembly 11 of the continuously variable transmission includes Figure 1The first gear on the left and the second gear on the right. When the vehicle speed is low, the oil outlet pressures of the first solenoid valve 211 and the shift branch pressure regulating valve 231 are adjusted so that the first solenoid valve 211 switches to the second working state and the shift branch pressure regulating valve 231 switches to the first working state; at the same time, the shift fork pressure regulating valve 234 can be adjusted to the second working state so that the right cavity of the shift fork 230 is connected to the oil outlet of the shift branch pressure regulating valve 231, and the left cavity is connected to the oil tank. At this time, the input shaft 15 and the output shaft 16 of the continuously variable transmission are transmitted through the first gear on the left. When the vehicle speed is high, the shift fork pressure regulating valve 234 is adjusted to the first working state so that the left cavity of the shift fork 230 is connected to the oil outlet of the shift branch pressure regulating valve 231, and the right cavity is connected to the oil tank. At this time, the input shaft 15 and the output shaft 16 of the continuously variable transmission are transmitted through the second gear on the right. When the vehicle speed is within an appropriate range, the oil outlet pressure of the shift branch pressure regulating valve 231 can be adjusted to switch the second solenoid valve 212 to the second working state. At the same time, the oil outlet pressure of the shift branch pressure regulating valve 231 is adjusted to switch the shift branch pressure regulating valve 231 to the second working state. The pulley clutch 14 is in a engaged state, the gear clutch 13, the reverse clutch 229 and the shift fork 230 are all in an isolated position, and the input shaft 15 and the output shaft 16 of the continuously variable transmission are transmitted through the pulley transmission assembly 12.

[0086] Moreover, when reversing, the pressure of the oil outlets of the shift branch pressure regulating valve 231 and the reverse pressure regulating valve 233 can be adjusted to switch the shift branch pressure regulating valve 231 to the first working state, the reverse pressure regulating valve 233 to the second working state, and the reverse clutch 229 to the engaged position. At the same time, the shift fork pressure regulating valve 234 is controlled to be in the second working state, so that the continuously variable transmission is transmitted through the first gear.

[0087] With such a structure, by providing the shift branch pressure regulating valve 231 and setting the normal pressure of the shift branch pressure regulating valve 231 to zero, functional safety problems in the event of unilateral failure can be prevented. In this embodiment, the shift branch pressure regulating valve 231 is also connected to the oil pan 18, so that when the parking pressure regulating valve 232 and the reverse pressure regulating valve 233 are unexpectedly stuck, the feedback pressure on the electromagnetic control end of the shift branch pressure regulating valve 231 increases, causing the shift branch pressure regulating valve 231 to move to the left, thereby connecting the output oil of the shift branch pressure regulating valve 231 to the oil pan 18, and achieving forced pressure relief.

[0088] In addition, the parking pressure regulating valve 232 , the reverse pressure regulating valve 233 and the shift fork pressure regulating valve 234 are all arranged in corresponding oil circuits via the shift branch pressure regulating valve 231 , which can also share the overflow burden of the pressure reducing valve 214 .

[0089] Further, the hydraulic control system also includes a pulley safety valve 235 disposed between the second solenoid valve 212 and the pulley clutch 14. The oil inlet of the pulley safety valve 235 is communicated with the oil outlet of the second solenoid valve 212, the first oil outlet is communicated with the oil tank, and the second oil outlet is communicated with the pulley clutch 14. The electromagnetic control end of the pulley safety valve 235 is communicated with the second oil outlet of the parking pressure regulating valve 232. The oil inlet of the first solenoid valve 211 is communicated with the second oil outlet of the pressure reducing valve 214, the first oil outlet is communicated with the oil tank, and the second oil outlet is communicated with the gear clutch 13. The spring control end of the first solenoid valve 211 is communicated with the second oil outlet of the first solenoid valve 211. The oil inlet of the second solenoid valve 212 is communicated with the second oil outlet of the pressure reducing valve 214, the first oil outlet is communicated with the oil tank, and the second oil outlet is communicated with the pulley safety valve 235. The spring control end of the second solenoid valve 212 is communicated with the second oil outlet of the second solenoid valve 212.

[0090] Specifically, when the pulley safety valve 235 is in the first working state, the oil inlet is connected to the second oil outlet; when it is in the second working state, the first oil outlet is connected to the second oil outlet. When the oil circuit pressure is abnormal, for example, when the pulley clutch 14 is unexpectedly stuck, the pulley safety valve 235 can cut off the oil supply to the pulley clutch 14 through the parking pressure regulating valve 232 to perform forced pressure relief.

[0091] Furthermore, the continuously variable transmission further includes a hydraulic torque converter 236 . The hydraulic control system further includes a torque converter switching valve 237 , a torque converter pressure regulating valve 238 and a torque converter solenoid valve 239 .

[0092] Among them, the torque converter switching valve 237 is arranged on the secondary oil circuit B, the first oil inlet of the torque converter switching valve 237 is connected to the oil outlet of the main oil circuit pressure regulating valve 217, the second oil inlet is connected to the torque converter pressure regulating valve 238, the first oil outlet is connected to the oil tank, the second oil outlet is connected to the locking chamber of the torque converter 236, the third oil outlet is connected to the lubricating oil circuit C, and the fourth oil outlet is connected to the unlocking chamber of the torque converter 236.

[0093] Specifically, the torque converter switching valve 237 can switch between an unlocked state and a locked state. When it is in the unlocked state, the second oil outlet of the torque converter switching valve 237 is connected to the third oil outlet, and the first oil inlet is connected to the fourth oil outlet. At this time, the hydraulic oil enters the unlocking chamber of the torque converter 236 through the first oil inlet, and enters the lubricating oil circuit C after passing through the locking chamber. When it is in the locked state, the oil in the secondary oil circuit B directly enters the lubricating oil circuit C, and the locking chamber of the torque converter 236 is connected to the torque converter pressure regulating valve 238 so that the unlocking chamber is connected to the oil tank. At this time, the torque converter 236 is in the locked state.

[0094] The oil inlet of the torque converter pressure regulating valve 238 is communicated with the second oil outlet of the pressure reducing valve 214 , the first oil outlet is communicated with the second oil inlet of the torque converter switching valve 237 , and the second oil outlet is communicated with the oil tank.

[0095] Specifically, when the torque converter pressure regulating valve 238 is in the first working state, its first oil outlet is connected to the second oil outlet; when it is in the second working state, the oil inlet is connected to the first oil outlet. When the torque converter 236 is in the locked state, its locking pressure is controlled by the torque converter pressure regulating valve 238. When the locking pressure of the torque converter 236 is lower than the target pressure, the torque converter pressure regulating valve 238 can be controlled to be in the second working position, at which time the locking chamber of the torque converter 236 is connected to the main oil circuit A until the locking pressure of the torque converter 236 reaches the target pressure; when the locking pressure of the torque converter 236 is greater than the target pressure, the torque converter pressure regulating valve 238 can be controlled to be in the first working position, at which time the locking chamber of the torque converter 236 is connected to the oil tank to reduce the locking pressure until the locking pressure of the torque converter 236 reaches the target pressure.

[0096] The oil inlet of the torque converter solenoid valve 239 is connected to the second oil outlet of the pressure reducing valve 214, the first oil outlet is connected to the oil tank, and the second oil outlet is respectively connected to the electromagnetic control end of the torque converter switching valve 237 and the electromagnetic control end of the torque converter pressure regulating valve 238. Through the setting of the torque converter solenoid valve 239, the torque converter switching valve 237 and the torque converter pressure regulating valve 238 can be dynamically controlled.

[0097] Furthermore, the oil inlets of the main oil circuit solenoid valve 227 , the torque converter solenoid valve 239 , the torque converter pressure regulating valve 238 , the slave cylinder solenoid valve 225 , the master cylinder solenoid valve 223 , the first solenoid valve 211 and the second solenoid valve 212 are all connected via the main oil circuit A.

[0098] Furthermore, the gear clutch 13 and the pulley clutch 14 are both connected to the oil pan 18, so that the output pressure of the first solenoid valve 211 connected to the gear clutch 13 and the output pressure of the second solenoid valve 212 connected to the pulley clutch 14 can be reduced. In addition, in the pulley drive mode, the oil volume of the lubricating oil circuit C is actively controlled by the main oil circuit pressure regulating valve 217, and the excess oil is introduced into the oil pan 18, which can improve the working efficiency of the oil pump and further reduce the oil consumption.

[0099] Furthermore, the lubricating oil circuit C is provided with an oil cooler 240 , a filter press 241 , and an oil spray nozzle 242 in series.

[0100] The oil spray nozzle 242 includes at least one outlet end, and the at least one outlet end is respectively disposed near the gear transmission assembly 11, the pulley transmission assembly 12, the gear clutch 13, and the pulley clutch 14. After the oil is collected in the oil cooler 240, the oil is lubricated to the clutch, the gear transmission assembly 11, and the pulley transmission assembly 12 through the filter press 241 and the oil spray nozzle 242.

[0101] Further, refer to Figure 4 , the hydraulic control system also includes an oil pump drive assembly. Among them, the oil pump drive assembly includes an engine 17 connected to a mechanical oil pump 215, and a generator 243 connected to an electronic oil pump 218. With such a structure, the mechanical oil pump 215 and the electronic oil pump 218 are driven by the engine 17 and the generator 243 respectively, so that sufficient oil supply can be guaranteed regardless of the driving state of the continuously variable transmission, thereby ensuring the reliability of system operation. In addition, the electronic oil pump 218 is driven by the generator 243, and is not controlled by the change in the speed of the engine 17, so the control accuracy of the flow rate is higher, thereby reducing the system fuel consumption.

[0102] It should be noted that the oil outlet connected to the oil tank in this embodiment can not only output oil, but under certain working conditions, such as when connected to other oil outlets, it can lead the oil in the oil tank to the corresponding solenoid valve, that is, it can be used as an oil inlet.

[0103] Next, the working process of the hydraulic control system is described.

[0104] In the pulley drive mode, the mechanical oil pump 215 is the power source. The mechanical oil pump 215 is driven by the engine 17, and the main oil circuit pressure can be dynamically controlled by the main oil circuit pressure regulating valve 217 and the main oil circuit solenoid valve 227. When the main oil circuit solenoid valve 227 fails, the system can release pressure through the main oil circuit safety valve 213. The rear end of the pressure reducing valve 214 can provide a stable input pressure (for example, 15 bar) for the main oil circuit solenoid valve 227, the torque converter solenoid valve 239, the slave cylinder solenoid valve 225, the master cylinder solenoid valve 223, the first solenoid valve 211 and the second solenoid valve 212.

[0105] The left side of the mechanical pump pressure regulating valve 216 is the pressure at the output end of the mechanical oil pump 215, and the right side is the spring pressure and the pressure of the main oil circuit A. When the pressure at the output end of the mechanical oil pump 215 is too high, the output oil of the mechanical oil pump 215 returns to the input end of the mechanical oil pump 215 through the mechanical pump pressure regulating valve 216. The left side of the main oil circuit pressure regulating valve 217 is the pressure of the main oil circuit A, and the right side is the spring and the output pressure of the main oil circuit solenoid valve 227. The left side of the main oil circuit solenoid valve 227 is acted on by the spring force, and the right side is controlled by the output pressure of the main oil circuit solenoid valve 227 and the valve controller. When the valve controller gives an action signal, the main oil circuit solenoid valve 227 moves to the right, and the output end of the main oil circuit solenoid valve 227 is connected to the oil pan 18, so that the main oil circuit pressure regulating valve 217 is in a connected state, thereby connecting the pressure of the main oil circuit A to the input end of the torque converter switching valve 237.

[0106] In gear drive mode, the mechanical oil pump 215 is used for basic lubrication. The electronic oil pump 218 is driven by the generator 243, the electronic pump switching valve 220 is in the left position, and the rear end of the electronic oil pump 218 is connected to the front end of the pressure reducing valve 214, providing a stable input pressure (e.g. 15 bar) for the main oil circuit solenoid valve 227, the torque converter solenoid valve 239, the slave cylinder solenoid valve 225, the active cylinder solenoid valve 223, the first solenoid valve 211, and the second solenoid valve 212. At the same time, the rear end of the electronic oil pump 218 is connected to the front end of the shift branch pressure regulating valve 231 to perform electronic shift control (ETRS). The left side of the electronic pump pressure regulating valve 219 is affected by the output pressure of the electronic oil pump 218, and the right side is controlled by the output pressure of the spring and the first solenoid valve 211. When the output pressure of the electronic oil pump 218 is greater than the spring force and the output pressure of the first solenoid valve 211, the electronic pump pressure regulating valve 219 is connected, and the electronic oil pump 218 is connected to the oil pan 18. When the output pressure of the electronic oil pump 218 is less than the spring force and the output pressure of the first solenoid valve 211, the electronic pump pressure regulating valve 219 is disconnected, and the output pressure of the electronic oil pump 218 increases, thereby realizing that the outlet pressure of the electronic oil pump 218 automatically follows the dynamic adjustment of the first solenoid valve 211. When the output pressure of the electronic oil pump 218 is greater than the preset pressure of the electronic pump safety valve (set between the electronic oil pump 218 and the electronic pump switching valve 220), the pressure is released through the electronic pump safety valve.

[0107] The active cylinder pressure is controlled by the active cylinder solenoid valve 223 and the active cylinder pressure regulating valve 224. The output pressure of the active cylinder solenoid valve 223 can be dynamically adjusted by sending a current command through the valve controller. The left side of the active cylinder pressure regulating valve 224 is affected by the oil pressure and spring force of the active cylinder solenoid valve 223, and the right side is affected by the feedback pressure of the active cylinder 221. When the pressure of the active cylinder 221 is lower than the target pressure, the active cylinder pressure regulating valve 224 moves to the right under the output pressure of the active cylinder solenoid valve 223, so that the main oil circuit A is connected with the active cylinder 221 until the pressure of the active cylinder 221 reaches the target pressure, and the valve core of the active cylinder pressure regulating valve 224 is balanced. When the pressure of the active cylinder 221 is higher than the target pressure, the active cylinder pressure regulating valve 224 moves to the left under the action of the feedback force and connects the pressure oil of the active cylinder 222 to the oil pan 18, thereby reducing the pressure of the active cylinder 221 until the pressure of the active cylinder 221 reaches the target pressure and the force on the valve core of the active cylinder pressure regulating valve 224 is balanced. The pressure control of the slave oil cylinder 222 is similar.

[0108] The state switching of the torque converter 236 is controlled by the torque converter solenoid valve 239 and the torque converter pressure regulating valve 238. The left side of the torque converter switching valve 237 is acted by the spring force, and the right side is acted by the output pressure of the torque converter solenoid valve 239. The output pressure of the torque converter solenoid valve 239 can be dynamically adjusted according to the current command issued by the valve controller. When the output pressure of the torque converter solenoid valve 239 is lower than a certain preset value, the torque converter switching valve 237 moves to the right under the action of the spring force. At this time, the torque converter 236 is in the torque conversion state, and the secondary oil circuit B at the outlet of the main oil circuit pressure regulating valve 217 is connected to the unlocking chamber, and after flowing through the locking chamber, it is connected to the oil cooler 240, and passes through the filter press 241 and then passes through the oil spray nozzle 242, thereby providing cooling and lubrication for the steel belt, clutch, etc.

[0109] When the output pressure of the torque converter solenoid valve 239 is higher than a preset value, the torque converter switching valve 237 moves to the left, the locking chamber is connected to the torque converter pressure regulating valve 238, the oil cooler 240 is connected to the secondary oil circuit B output by the main oil circuit pressure regulating valve 217, and the unlocking chamber is connected to the oil pan 18. At this time, the hydraulic torque converter 236 is in a locked state. The locking pressure of the hydraulic torque converter 236 can be dynamically controlled by the torque converter pressure regulating valve 238. The right side of the torque converter pressure regulating valve 238 is affected by the oil pressure of the torque converter solenoid valve 239, and the left side is affected by the locking feedback pressure of the hydraulic torque converter 236 and the spring force. When the locking pressure of the hydraulic torque converter 236 is lower than the target pressure, the torque converter pressure regulating valve 238 moves to the left side under the output pressure of the torque converter solenoid valve 239, so that the pressure reducing valve 214 is connected with the locking chamber until the locking pressure of the hydraulic torque converter 236 reaches the target pressure, and the valve core of the torque converter pressure regulating valve 238 is balanced. When the locking pressure is higher than the target pressure, the torque converter pressure regulating valve 238 moves to the right side under the action of the feedback force, and connects the locking chamber with the oil pan 18, thereby reducing the locking pressure of the hydraulic torque converter 236 until the locking pressure of the hydraulic torque converter 236 reaches the target.

[0110] The output pressure of the shift branch pressure regulating valve 231 in the electronic shift (ETRS) control system can be dynamically adjusted by sending a current command from the valve controller. The shift fork pressure regulating valve 234 dynamically adjusts the valve core position by sending a current command from the valve controller to achieve position control of the shift fork 230. The left side of the reverse pressure regulating valve 233 is subject to spring pressure and the pressure of the reverse clutch 229, and the left side is dynamically adjusted by the current command sent by the valve controller. When the valve controller gives an instruction, the reverse pressure regulating valve 233 moves to the left, and the output oil of the shift branch pressure regulating valve 231 is connected to the reverse clutch 229. The left side of the parking pressure regulating valve 232 is subject to spring pressure and the output pressure of the parking pressure regulating valve 232, and the left side is dynamically adjusted by sending a current command from the valve controller. When the valve controller gives an instruction, the parking pressure regulating valve 232 moves to the left, and the output oil of the shift branch pressure regulating valve 231 is connected to the parking clutch 228.

[0111] The gear clutch 13 is controlled by the first solenoid valve 211. When receiving the current command sent by the valve controller, the gear clutch 13 moves to the left, and the gear clutch 13 is connected to the rear end of the pressure reducing valve 214; when the output pressure of the first solenoid valve 211 is too large, the feedback pressure on the left side of the first solenoid valve 211 increases, the first solenoid valve 211 moves to the right, and the first solenoid valve is connected to the oil pan 18, thereby reducing the output pressure of the first solenoid valve 211, until the output pressure of the first solenoid valve 211 reaches the target pressure, and the valve core of the first solenoid valve 211 is balanced.

[0112] The pulley clutch 14 is controlled by the second solenoid valve 212 and the pulley safety valve 235, wherein the control principle of the second solenoid valve 212 is the same as that of the first solenoid valve 211. A pulley safety valve 235 is added between the pulley clutch 14 and the second solenoid valve 212. The left side of the pulley safety valve 235 is acted upon by the preset pressure of the spring, and the right side is acted upon by the output pressure of the parking pressure regulating valve 232. Under normal conditions, the pulley clutch 14 and the rear end of the second solenoid valve 212 are connected. When the parking clutch 228 is in the working state, the output pressure of the second solenoid valve 212 pushes the pulley safety valve 235 to move to the left, and the pulley clutch 14 is connected to the oil pan 18, ensuring that the pulley clutch 14 is in the non-working state. When the pulley clutch 14 is unexpectedly stuck, the parking pressure regulating valve 232 can also be used to force the pressure of the pulley clutch 14 to be relieved.

[0113] It should be noted that, in this embodiment, all oil tanks can also be connected to the oil pan 18 .

[0114] Embodiment 2:

[0115] Based on the above-mentioned hydraulic control system of the continuously variable transmission, this embodiment provides another hydraulic control system of the continuously variable transmission. The difference between this embodiment and embodiment 1 is only that the structure of the first oil pump assembly is different. Specifically, refer to Figure 5 The mechanical oil pump 215 in this embodiment is a dual-outlet mechanical pump, and the mechanical pump pressure regulating valve 216 is replaced by a mechanical oil pump switch valve 244 and a mechanical oil pump switching valve 245. In addition, the main oil circuit pressure regulating valve 217 is not a simple comparison valve, but an ordinary solenoid valve.

[0116] Specifically, the mechanical oil pump 215 includes a first oil outlet and a second oil outlet. The oil inlet of the mechanical oil pump switching valve 245 is connected to the first oil outlet of the mechanical oil pump 215, and the oil outlet is connected to the oil tank. When the mechanical oil pump switching valve 245 is in the first working state, the oil inlet and the oil outlet are connected; when it is in the second working state, the oil inlet and the oil outlet are isolated.

[0117] The mechanical oil pump switch valve 244 is a solenoid valve, whose oil inlet is connected to the pressure reducing valve 214, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the mechanical oil pump switch valve 245. When it is in the first working state, the first oil outlet is connected to the second oil outlet, and when it is in the second working state, the oil inlet is connected to the second oil outlet.

[0118] When the continuously variable transmission is in the pulley drive mode, the mechanical oil pump 215 is the main oil supply component. At this time, the mechanical oil pump switching valve 245 is adjusted to be in the second working state, and the hydraulic oil from the first oil outlet and the hydraulic oil from the second oil outlet are both collected in the main oil circuit A, and the mechanical pump 8 switches to the dual pump mode. When the continuously variable transmission is in the gear drive mode, the mechanical oil pump switching valve 245 is adjusted to be in the first working state, and the hydraulic oil from the first oil outlet returns to the oil tank, and only the hydraulic oil from the second oil outlet flows to the main oil circuit A, and the mechanical oil pump 215 switches to the single pump mode to reduce energy consumption.

[0119] The working position switching of the mechanical oil pump switch valve 244 is controlled by the spring force of its spring control end and the output end pressure of the mechanical oil pump switch valve 245. When the mechanical oil pump 215 needs to switch to the dual-pump mode, the pressure at the electromagnetic control end of the mechanical oil pump switch valve 244 is adjusted so that the mechanical oil pump switch valve 244 switches to the first working state, thereby making the pressure at the electromagnetic control end of the mechanical oil pump switch valve 245 less than the pressure at the spring control end, and the mechanical oil pump switch valve 245 is in the second working state; when the mechanical oil pump 215 needs to switch to the single-pump mode, it is only necessary to control the pressure at the electromagnetic control end of the mechanical oil pump switch valve 244 so that the mechanical oil pump switch valve 244 switches to the second working state, thereby making the pressure at the electromagnetic control end of the mechanical oil pump switch valve 244 greater than the pressure at the spring control end, and the mechanical oil pump switch valve 245 switches to the first working state.

[0120] The oil inlet of the main oil circuit pressure regulating valve 217 is connected to the mechanical oil pump 215, the first oil outlet is connected to the secondary oil circuit B, and the second oil outlet is connected to the oil tank. When it is in the first working state, the oil inlet is connected to both the first and second oil outlets; when it is in the second working state, the oil inlet is connected to the first oil outlet; when it is in the third working state, the oil inlet, the first oil outlet, and the second oil outlet are all blocked.

[0121] The hydraulic control system provided in this embodiment can adopt the dual-port oil pumping mode when a large amount of oil supply is required through the setting of the mechanical oil pump 215 with dual outlets to ensure the reliability of system operation, and switch to the single-port oil pumping mode when a small amount of oil supply is required to reduce energy consumption, thereby improving the control energy efficiency of the hydraulic control system.

Claims

1. A hydraulic control system for a continuously variable transmission, characterized in that: The continuously variable transmission comprises a gear transmission assembly, a pulley transmission assembly, a gear clutch, and a pulley clutch, wherein the hydraulic control system drives the gear clutch and the pulley clutch to switch between a first clutch state in which the gear clutch is disengaged and the pulley clutch is engaged, and a second clutch state in which the gear clutch is engaged and the pulley clutch is disengaged, so as to drive the continuously variable transmission to switch between a pulley driving mode in which the pulley transmission assembly transmits power from an input shaft of the continuously variable transmission to an output shaft and a gear driving mode in which the gear transmission assembly transmits power from the input shaft to the output shaft; and The hydraulic control system comprises: A clutch control valve group, the clutch control valve group includes a first solenoid valve and a second solenoid valve, the first solenoid valve and the second solenoid valve are both arranged on the main oil circuit of the hydraulic control system, the oil outlet of the first solenoid valve is connected to the gear clutch, and the oil outlet of the second solenoid valve is connected to the pulley clutch; A main oil circuit control valve, wherein the main oil circuit control valve is arranged on the main oil circuit, and an oil outlet of the main oil circuit control valve is respectively connected to an oil inlet of the first solenoid valve and an oil inlet of the second solenoid valve; a first oil pump assembly, the first oil pump assembly comprising a mechanical oil pump, a mechanical pump pressure regulating valve and a main oil circuit pressure regulating valve, the oil outlet of the mechanical oil pump being respectively connected to the oil inlet of the main oil circuit control valve, the oil inlet of the mechanical pump pressure regulating valve and the oil inlet of the main oil circuit pressure regulating valve, the oil outlet of the mechanical pump pressure regulating valve being connected to the oil pan of the continuously variable transmission, and the oil outlet of the main oil circuit pressure regulating valve being connected to the lubricating oil circuit via the secondary oil circuit of the hydraulic control system; the main oil circuit pressure regulating valve driving the oil of the mechanical oil pump to switch between a first oil supply state in which the oil flows only to the main oil circuit control valve and a first lubrication state in which the oil flows only to the lubricating oil circuit; a second oil pump assembly, the second oil pump assembly comprising an electronic oil pump and an electronic pump control valve, the oil inlet of the electronic pump control valve being in communication with the oil outlet of the electronic oil pump, and the oil outlet of the electronic pump control valve being in communication with the oil inlet of the main oil circuit control valve and the lubricating oil circuit respectively; and When the continuously variable transmission is in the first clutch state, the first oil pump assembly is in the first oil supply state, and the second oil pump assembly is in the second lubrication state in which the oil outlet of the electronic pump control valve is only connected to the lubrication oil circuit; When the continuously variable transmission is in the second clutch state, the first oil pump assembly is in the first lubrication state, and the second oil pump assembly is in the second oil supply state in which the oil outlet of the electronic pump control valve is connected only to the oil inlet of the main oil circuit control valve.

2. The hydraulic control system of a continuously variable transmission according to claim 1, characterized in that: The hydraulic control system also includes a main oil circuit solenoid valve; The oil inlet of the main oil circuit solenoid valve is connected to the main oil circuit, and the oil outlet is connected to the spring control end of the main oil circuit pressure regulating valve; and The mechanical pump pressure regulating valve and the main oil circuit pressure regulating valve are both comparison valves; in The electromagnetic control end of the mechanical pump pressure regulating valve is communicated with the oil outlet of the mechanical oil pump, and the spring control end is communicated with the main oil circuit; The electromagnetic control end of the main oil circuit pressure regulating valve is communicated with the oil outlet of the mechanical oil pump.

3. The hydraulic control system of a continuously variable transmission as claimed in claim 2, characterized in that: The main oil circuit control valve includes a main oil circuit safety valve and a pressure reducing valve; The oil inlet of the main oil circuit safety valve is connected to the oil outlet of the mechanical oil pump, and the oil outlet is connected to the oil tank; The oil inlet of the pressure reducing valve is respectively communicated with the oil outlet of the mechanical oil pump and the oil outlet of the electronic pump control valve, the first oil outlet of the pressure reducing valve is communicated with the oil tank, and the second oil outlet of the pressure reducing valve is respectively communicated with the oil inlet of the first solenoid valve and the oil inlet of the second solenoid valve; The electromagnetic control end of the main oil circuit safety valve is communicated with the main oil circuit, and the spring control end is communicated with the second oil outlet of the pressure reducing valve; The electromagnetic control end of the pressure reducing valve is communicated with the main oil circuit, and the spring control end is communicated with the second oil outlet of the pressure reducing valve.

4. The hydraulic control system of the continuously variable transmission according to claim 3, characterized in that: The electronic pump control valve includes an electronic pump pressure regulating valve and an electronic pump switching valve; The electronic pump pressure regulating valve is a comparison valve, and the oil inlet of the electronic pump pressure regulating valve is connected to the oil outlet of the electronic oil pump, and the oil outlet is connected to the oil tank; the electromagnetic control end of the electronic pump pressure regulating valve is connected to the oil outlet of the electronic oil pump, and the spring control end is connected to the oil outlet of the first electromagnetic valve; The oil inlet of the electronic pump switching valve is connected to the oil outlet of the electronic oil pump, the first oil outlet is connected to the oil inlet of the main oil circuit control valve, the second oil outlet is connected to the lubrication oil circuit via a lubrication pipeline, and the electromagnetic control end of the electronic pump switching valve is connected to the oil outlet of the second solenoid valve.

5. The hydraulic control system of a continuously variable transmission as claimed in claim 4, characterized in that: The pulley transmission assembly includes a driving wheel, a driven wheel, a belt body sleeved on the driving wheel and the driven wheel, and a driving oil cylinder and a driven oil cylinder respectively arranged on both sides of the driving wheel and the driven wheel along the rotation axis of the belt body; and The hydraulic control system also includes an active oil cylinder control valve group and a slave oil cylinder control valve group; in The active cylinder control valve group includes an active cylinder solenoid valve and an active cylinder pressure regulating valve; The oil inlet of the active cylinder solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder pressure regulating valve; the electromagnetic control end of the active cylinder solenoid valve is connected to the active cylinder pressure regulating valve; The oil inlet of the active cylinder pressure regulating valve is connected to the oil outlet of the mechanical oil pump, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the active cylinder; the electromagnetic control end of the active cylinder pressure regulating valve is connected to the second oil outlet of the active cylinder electromagnetic valve, and the spring control end is connected to the oil circuit connecting the active cylinder pressure regulating valve and the active cylinder; and The slave cylinder control valve group includes a slave cylinder solenoid valve and a slave cylinder pressure regulating valve; The oil inlet of the slave cylinder solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the slave cylinder pressure regulating valve; the electromagnetic control end of the slave cylinder solenoid valve is connected to the slave cylinder pressure regulating valve; The oil inlet of the slave cylinder pressure regulating valve is respectively connected to the first oil outlet of the electronic pump switching valve and the oil outlet of the mechanical oil pump, the first oil outlet of the slave cylinder pressure regulating valve is connected to the oil tank, and the second oil outlet is connected to the slave cylinder; the electromagnetic control end of the slave cylinder pressure regulating valve is connected to the second oil outlet of the slave cylinder solenoid valve, and the spring control end is connected to the oil circuit connecting the slave cylinder pressure regulating valve and the slave cylinder.

6. The hydraulic control system of the continuously variable transmission according to claim 5, characterized in that: The continuously variable transmission further includes a parking clutch, a reverse clutch and a shift fork; and The hydraulic control system includes a shift branch pressure regulating valve, a parking pressure regulating valve, a reverse pressure regulating valve and a shift fork pressure regulating valve; The shift branch pressure regulating valve is connected to the parking clutch, the reverse clutch and the shift fork via the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve respectively; and the oil inlet of the shift branch pressure regulating valve is communicated with the oil outlet of the mechanical oil pump and the first oil outlet of the electronic pump switching valve respectively, the first oil outlet of the shift branch pressure regulating valve is communicated with the oil tank, and the second oil outlet is communicated with the parking pressure regulating valve, the reverse pressure regulating valve and the shift fork pressure regulating valve respectively; the electromagnetic control end of the shift branch pressure regulating valve is communicated with the second oil outlet of the shift branch pressure regulating valve; The oil inlet of the parking pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the parking clutch; the spring control end of the parking pressure regulating valve is connected to the second oil outlet of the parking pressure regulating valve; The oil inlet of the reverse pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the reverse clutch; the spring control end of the reverse pressure regulating valve is connected to the second oil outlet of the reverse pressure regulating valve; The oil inlet of the shift fork pressure regulating valve is connected to the second oil outlet of the shift branch pressure regulating valve, the first oil outlet is connected to the oil tank, the second oil outlet is connected to one side cavity of the shift fork, and the third oil outlet is connected to the other side cavity of the shift fork.

7. The hydraulic control system of a continuously variable transmission as claimed in claim 6, characterized in that: The hydraulic control system further includes a pulley safety valve disposed between the second solenoid valve and the pulley clutch; The oil inlet of the pulley safety valve is connected to the oil outlet of the second solenoid valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the pulley clutch; The electromagnetic control end of the pulley safety valve is communicated with the second oil outlet of the parking pressure regulating valve; The oil inlet of the first solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the gear clutch; the spring control end of the first solenoid valve is connected to the second oil outlet of the first solenoid valve; The oil inlet of the second solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is connected to the pulley safety valve; the spring control end of the second solenoid valve is connected to the second oil outlet of the second solenoid valve.

8. The hydraulic control system of a continuously variable transmission as claimed in claim 7, characterized in that: The continuously variable transmission also includes a torque converter; The hydraulic control system also includes a torque converter switching valve, a torque converter pressure regulating valve and a torque converter solenoid valve; wherein The torque converter switching valve is arranged on the secondary oil circuit, the first oil inlet of the torque converter switching valve is communicated with the oil outlet of the main oil circuit pressure regulating valve, the second oil inlet is communicated with the torque converter pressure regulating valve, the first oil outlet is communicated with the oil tank, the second oil outlet is communicated with the locking chamber of the hydraulic torque converter, the third oil outlet is communicated with the lubricating oil circuit, and the fourth oil outlet is communicated with the unlocking chamber of the hydraulic torque converter; The oil inlet of the torque converter pressure regulating valve is communicated with the second oil outlet of the pressure reducing valve, the first oil outlet is communicated with the second oil inlet of the torque converter switching valve, and the second oil outlet is communicated with the oil tank; The oil inlet of the torque converter solenoid valve is connected to the second oil outlet of the pressure reducing valve, the first oil outlet is connected to the oil tank, and the second oil outlet is respectively connected to the electromagnetic control end of the torque converter switching valve and the electromagnetic control end of the torque converter pressure regulating valve.

9. The hydraulic control system of a continuously variable transmission as claimed in claim 8, characterized in that: The oil inlets of the main oil circuit solenoid valve, the torque converter solenoid valve, the torque converter pressure regulating valve, the slave cylinder solenoid valve, the master cylinder solenoid valve, the first solenoid valve and the second solenoid valve are all connected via the main oil circuit.

10. The hydraulic control system of a continuously variable transmission according to any one of claims 1 to 9, characterized in that: The gear clutch and the pulley clutch are both connected to the oil pan; and The lubricating oil circuit is provided with an oil cooler, a filter press, and an oil spray nozzle in series; The oil spray nozzle comprises at least one outlet end, and at least one of the outlet ends is respectively disposed near the gear transmission assembly, the pulley transmission assembly, the gear clutch, and the pulley clutch; and The hydraulic control system further includes an oil pump driving assembly, wherein the oil pump driving assembly includes an engine connected to the mechanical oil pump, and a generator connected to the electronic oil pump.

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