Hydraulic control system, control method, electronic device, and medium for continuously variable transmission

Abstract

The application provides a hydraulic control system, a control method, an electronic device and a medium for a continuously variable transmission, wherein the hydraulic control system is connected with a hydraulic system and a transmission controller of the continuously variable transmission respectively, and the transmission controller is connected with an engine controller of a vehicle. The hydraulic control system calculates an actual flow rate flowing into a lubricating cooling system oil path according to a current flow rate of oil flowing through a main oil path, a flow rate of oil flowing into an execution control system oil path, and a leakage flow rate of the hydraulic system, controls an oil pump control valve assembly and a main oil path control valve assembly according to the actual flow rate flowing into the lubricating cooling system oil path, a preset redundancy flow rate, and a required flow rate of the lubricating cooling system oil path, and sends a rotating speed request information to the engine controller to control the working states of the first oil pump and the second oil pump, the flow rate and pressure of the oil flowing through the main oil path, and the rotating speed of the engine. The scheme makes the hydraulic system of the continuously variable transmission in the most efficient working interval.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, and in particular to a hydraulic control system, control method, electronic equipment, and medium for a continuously variable transmission (CVT). Background Technology

[0002] Continuously variable transmissions (CVTs) are one of the important components of a vehicle's powertrain, such as... Figure 1 As shown, a continuously variable transmission (CVT) includes a hydraulic system 104, a torque converter 105, a clutch 106, and a drive belt 107. The CVT is connected to a transmission controller 103, which in turn is connected to an engine controller 102. The engine controller 102 is connected to the engine 101, allowing the transmission controller 103 to control the engine 101 based on the CVT's status information. Specifically, the CVT uses the hydraulic system 104 to engage the drive belt 107 with variable-diameter drive and driven pulleys to transmit power, thus achieving continuous changes in the transmission ratio. This continuous change in the transmission ratio allows for a dynamic optimal match between vehicle resistance and engine load, ensuring the engine 101 always operates in its high-efficiency range and performs at its best according to the driver's intentions.

[0003] In fact, continuously variable transmissions (CVTs) are less efficient than traditional manual transmissions and dual-clutch automatic transmissions. The reason for this lower efficiency is the significant wear and tear on the CVT's hydraulic system. Figure 2 As shown, in the prior art, to reduce the losses in the hydraulic system 104, two oil pumps 201 and 202 are installed in the hydraulic system 104 of the continuously variable transmission (CVT). An oil pump switching valve 203 is used to switch the operating states of the two oil pumps 201 and 202, and a solenoid valve 204 controls the oil pump switching valve 203. With this structure, by controlling the action of the oil pump switching valve 203 through the solenoid valve 204 or feedback loops 210 and 211, either oil pump 201 or oil pump 202 can operate independently, thereby reducing system losses. Alternatively, when the required flow rate of the system's oil circuit 207 and lubrication circuit 209 is high, oil pumps 201 and 202 can operate simultaneously to meet the system's execution (including speed ratio changes, clutch engagement, etc.) and lubrication requirements, preventing hardware damage caused by insufficient system performance or lubrication.

[0004] The hydraulic system 104 also includes a main oil circuit. The inlet oil circuit of the main oil circuit is connected to the oil pan, and the outlet oil circuit is connected to the lubrication oil circuit 209 and the actuator oil circuit 207. A main oil circuit pressure regulating valve 206 is also installed on the main oil circuit to control the oil pressure. The state of the main oil circuit pressure regulating valve 206 is controlled by a solenoid valve 205. Feedback loops 210, 211, and 212 can work with the main oil circuit to control the oil pump switching valve 203 and the solenoid valves 204 and 205. Furthermore, the state of the solenoid valves 204 and 205 is also controlled by the control oil circuit 208. The existing strategy for switching the working states of the two oil pumps 201 and 202 is as follows: when the speed of the engine 101 is lower than a certain value, the oil pump switching valve 203 is controlled to move in the direction of dual pump operation so that the two oil pumps 201 and 202 are in the oil supply state at the same time; when the speed of the engine 101 is higher than a certain value, the oil pump switching valve 203 is controlled to move in the direction of single pump operation so that the oil pump 202 supplies oil alone.

[0005] However, in the prior art, the state of the oil pump switching valve 203 is simply controlled based on the engine speed 101. This may result in the flow rate of oil pumps 201 and 202 failing to meet the needs of the actuator and lubrication; conversely, it may also result in the flow rate of oil pumps 201 and 202 exceeding the actual required flow rate, leading to energy waste. Therefore, the hydraulic system 104 of the continuously variable transmission in the prior art suffers from low precision in controlling the oil pump flow rate. Summary of the Invention

[0006] The purpose of this invention is to solve the problem of low flow control accuracy of the oil pump in the hydraulic system of continuously variable transmissions (CVTs) in the prior art.

[0007] To address the aforementioned problems, this invention discloses a hydraulic control system for a continuously variable transmission (CVT). The hydraulic control system is connected to the CVT's hydraulic system and a transmission controller, which in turn is connected to the vehicle's engine controller. The hydraulic system includes an oil pump control valve assembly connected to a first oil pump and a second oil pump, controlling their operating states. A main oil circuit is also included, with its input end connected to a hydraulic oil chamber and its output end connected to both the CVT's execution control system oil circuit and lubrication / cooling system oil circuit. The outlet oil circuits of the first and second oil pumps are connected to the main oil circuit. The main oil circuit is equipped with a main oil... The main oil circuit control valve assembly controls the flow rate and pressure of the oil flowing through the main oil circuit. Furthermore, the hydraulic control system calculates the actual flow rate into the lubrication and cooling system based on the current flow rate of the oil flowing through the main oil circuit from the hydraulic system, the flow rate of the oil flowing into the actuator control system's oil circuit, and the leakage flow rate of the hydraulic system. Based on the actual flow rate into the lubrication and cooling system's oil circuit, a preset redundant flow rate, and the required flow rate of the lubrication and cooling system's oil circuit, the system controls the oil pump control valve assembly and the main oil circuit control valve assembly, and sends speed request information to the engine controller to control the operating status of the first and second oil pumps, the flow rate and pressure of the oil flowing through the main oil circuit, and the engine speed.

[0008] By adopting the above solution, the hydraulic control system takes into account the needs of the execution control system, the lubrication and cooling needs, and the actual flow rate of the oil pump when controlling the oil pump control valve assembly and the main oil circuit control valve assembly. This allows the hydraulic system to operate in its most efficient range, reducing hydraulic system capacity loss and improving gearbox efficiency. It also meets the flow requirements of the execution system under rapid action and extreme conditions, ensuring gearbox performance while effectively protecting the gearbox and extending its service life.

[0009] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission disclosed in this embodiment of the present invention includes an oil pump control valve assembly comprising: an oil pump switching valve, which is connected to a first oil pump and a second oil pump.

[0010] A switching control valve is connected to an oil pump switching valve via a first control oil circuit. The switching control valve controls the flow rate and pressure of the oil flowing through the first control oil circuit to control the operating status of the first and second oil pumps. The main oil circuit control valve assembly includes: a pressure regulating valve, which regulates the flow rate and pressure of the oil flowing through the main oil circuit; and a regulating control valve, which is connected to the pressure regulating valve via a second control oil circuit. The regulating control valve controls the flow rate and pressure of the oil flowing through the second control oil circuit to control the pressure regulating valve.

[0011] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission disclosed in the present invention comprises an oil pump switching valve, a switching control valve, a pressure regulating valve, and a regulating control valve, all of which are solenoid valves.

[0012] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment is connected to the execution control system of the CVT via an execution control system oil circuit. The execution control system of the CVT includes a driving steel belt, a driven steel belt, a clutch, and a torque converter. The execution control system oil circuit includes a driving steel belt control oil circuit, a driven steel belt control oil circuit, a clutch control oil circuit, and a torque converter control oil circuit. The input end of the driving steel belt control oil circuit is connected to the output end of the main oil circuit, and its output end is connected to the driving steel belt. The control oil circuit is also equipped with an active steel belt control valve; the input end of the driven steel belt control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the driven steel belt, and the driven steel belt control oil circuit is also equipped with a driven steel belt control valve; the input end of the clutch control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the clutch, and the clutch control oil circuit is also equipped with a clutch control valve; the input end of the hydraulic torque converter control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the hydraulic torque converter, and the hydraulic torque converter control oil circuit is also equipped with a hydraulic torque converter control valve.

[0013] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment includes: a valve control unit, which includes an actuator valve control component, a main oil circuit valve control component, and an oil pump valve control component; wherein the actuator valve control component is connected to each control valve in the oil circuit of the execution control system, the main oil circuit valve control component is connected to the main oil circuit control valve assembly, and the oil pump valve control component is connected to the oil pump control valve assembly; an execution control system status parameter acquisition unit, which is connected to the transmission controller and the CVT execution control system, acquires the execution control system status parameters from the execution control system, and sends the execution control system status parameters to the transmission controller; and a control current generation unit, which includes an actuator current generation component, a main oil circuit current generation component, and an oil pump current generation component that are communicatively connected to each other, the actuator current generation component being communicatively connected to the transmission controller, and receiving the execution control system status parameters from the transmission controller; wherein the actuator current generation component is connected to the actuator valve control component, calculates the actuator target control pressure according to the pre-input pressure control requirements, and generates a preset first current according to the actuator target control pressure. The system generates a rule to obtain the actuator control current and outputs it to the actuator valve control assembly. This assembly controls the states of the driving steel belt control valve, driven steel belt control valve, clutch control valve, and torque converter control valve. The main oil circuit current generation assembly is connected to the main oil circuit valve control component. Based on the actuator target control pressure from the actuator current generation assembly and the pressure demand information from the oil pump current generation assembly, it calculates the main oil circuit valve target control pressure. Based on this target control pressure, it obtains the main oil circuit valve control current according to the first current generation rule and outputs it to the main oil circuit valve. The control component controls the state of the main oil circuit control valve assembly through the main oil circuit valve control component; the oil pump current generating component is connected to the oil pump valve control component, calculates the target control flow of the oil pump valve based on the pre-input flow control requirements, the actuator target control pressure and the execution control system state parameters from the actuator current generating component, and the main oil circuit valve target control pressure from the main oil circuit current generating component, and obtains the oil pump valve control current according to the oil pump valve target control flow using a preset second current generation rule, and outputs the oil pump valve control current to the oil pump valve control component to control the state of the oil pump control valve assembly through the oil pump valve control component.

[0014] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment further includes a pressure control demand acquisition unit. The pressure control demand acquisition unit is connected to both the transmission controller and the CVT's execution control system, acquires pressure control demands from the execution control system, and sends the pressure control demands to the transmission controller. The transmission controller is also connected to an actuator current generating component, sending the pressure control demands to the actuator current generating component. The actuator valve control component includes: a driving steel belt control component, a driven steel belt control component, a clutch control component, and a torque converter control component. The actuator current generating component includes: a steel belt current generating component, a clutch current generating component, and a torque converter current generating component.

[0015] The pressure control requirements include: belt pressure control requirements, clutch pressure control requirements, and torque converter pressure control requirements; the actuator target control pressures include the active belt control pressure, driven belt control pressure, clutch control pressure, and torque converter control pressure; the actuator control currents include the active belt control current, driven belt control current, clutch control current, and torque converter control current; wherein the belt current generating component calculates the active belt control pressure and driven belt control pressure based on the belt pressure control requirements from the transmission controller, and outputs the active belt control current and driven belt control current to the active belt control component and driven belt control component respectively according to the first current generation rule. The current is used to control the active steel belt control component and the driven steel belt control component respectively according to the active steel belt control current and the driven steel belt control current; the clutch current generating component calculates the clutch control pressure according to the clutch pressure control requirements from the transmission controller, and outputs the clutch control current to the clutch control component according to the clutch control pressure and the first current generation rule, so as to control the clutch control component according to the clutch control current; the torque converter current generating component calculates the torque converter control pressure according to the torque converter pressure control requirements from the transmission controller, and outputs the torque converter control current to the torque converter control component according to the torque converter control pressure and the first current generation rule, so as to control the torque converter control component according to the torque converter control current.

[0016] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment of the present invention has the following requirements for steel belt pressure control: vehicle pedal opening, CVT drive pulley speed, CVT driven pulley speed, and engine torque; clutch pressure control requirements: vehicle pedal opening, engine speed, CVT turbine speed, and vehicle current gear; torque converter pressure control requirements: vehicle pedal opening, engine speed, CVT turbine speed, and current vehicle speed; and the preset first current generation rule is: the pressure-current curve of the solenoid valve obtained through calibration.

[0017] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment includes a main oil circuit current generating component comprising a main oil circuit pressure calculation component and a main oil circuit current generating component. The signal input terminal of the main oil circuit pressure calculation component is connected to an oil pump current generating component and an actuator current generating component, respectively, and the signal output terminal is connected to the signal input terminal of the main oil circuit current generating component. The signal output terminal of the main oil circuit current generating component is connected to a main oil circuit valve control component. Furthermore, the main oil circuit pressure calculation component calculates the main oil circuit valve target control pressure based on the actuator target control pressure from the actuator current generating component, the pressure demand information from the oil pump current generating component, and redundant flow. The main oil circuit current generating component obtains the main oil circuit valve control current according to the main oil circuit valve target control pressure from the main oil circuit pressure calculation component and a first current generation rule, and outputs the main oil circuit valve control current to the main oil circuit valve control component.

[0018] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission disclosed in the present invention has a preset redundant flow range of 0.8L / min to 1.2L / min.

[0019] By adopting the above scheme, since redundant flow is considered when calculating the target control pressure of the main oil circuit valve, the calculated target control pressure of the main oil circuit valve can be more accurate, which in turn enables more precise control of the pressure and flow of the oil in the main oil circuit, thereby improving the working efficiency of the gearbox.

[0020] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment of the present invention includes a transmission controller connected to a vehicle controller to obtain flow control requirements from the vehicle controller; an oil pump current generating component includes a flow calculation component and an oil pump current generating component; wherein the signal input terminal of the flow calculation component is connected to the main oil circuit pressure calculation component, the actuator current generating component, and the transmission controller respectively, and the output terminal is connected to the signal input terminal of the oil pump current generating component, and the signal output terminal of the oil pump current generating component is connected to the oil pump valve control component; the flow calculation component calculates the target control flow of the oil pump valve based on the flow control requirements from the transmission controller, the actuator target control pressure from the actuator current generating component, the state parameters of the actuator control system, and the main oil circuit valve target control pressure from the main oil circuit pressure calculation component; the oil pump current generating component obtains the oil pump valve control current according to the oil pump valve target control flow from the flow calculation component and a second current generation rule, and outputs the oil pump valve control current to the oil pump valve control component.

[0021] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission disclosed in this embodiment of the present invention has flow control requirements including engine speed, engine oil temperature, current vehicle speed, and the current gear of the vehicle; the state parameters of the execution control system include: the speed ratio of the driving steel belt and the driven steel belt, the rate of change of the speed ratio of the driving steel belt and the driven steel belt, the state of the clutch, and the state of the hydraulic torque converter; the preset second current generation rule is: the flow-current curve of the solenoid valve obtained by calibration.

[0022] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment further includes an actuator flow calculation parameter acquisition unit. The actuator flow calculation parameter acquisition unit is connected to both the transmission controller and the CVT's execution control system, acquires actuator flow calculation parameters from the execution control system, and sends the actuator flow calculation parameters to the transmission controller. The transmission controller is connected to the vehicle controller and acquires vehicle status parameters from the vehicle controller. The flow calculation component includes: a system flow calculation unit, whose signal input terminal is connected to the transmission controller, and calculates the system flow based on the vehicle status parameters from the transmission controller and the actuator flow calculation parameters; an oil pump status determination unit, whose signal input terminal is connected to a first oil pump and acquires the oil flow rate of the first oil pump; and an oil pump flow calculation unit, whose input terminal is connected to the output terminal of the oil pump status determination unit and the system flow rate. The output of the calculation unit is connected to the output of the main oil circuit pressure calculation component. It calculates the current flow rate of the oil flowing through the main oil circuit based on the oil flow rate of the first oil pump from the oil pump status determination unit, the system flow rate from the system flow calculation unit, and the redundant flow rate from the main oil circuit pressure calculation component. The flow demand calculation unit has its signal input connected to the signal output of the system flow calculation unit and the oil pump flow calculation unit, respectively. It calculates the actual flow rate into the lubrication and cooling system oil circuit based on the system flow rate from the system flow calculation unit and the current flow rate of the oil flowing through the main oil circuit from the oil pump flow calculation unit. Based on the actual flow rate into the lubrication and cooling system oil circuit and the required flow rate of the lubrication and cooling system oil circuit, it generates boost information, flow demand information, and speed request information. It controls the pressure of the oil flowing through the main oil circuit based on the boost information, controls the flow rate of the oil flowing through the main oil circuit based on the flow demand information, and controls the engine speed based on the speed request information.

[0023] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission (CVT) disclosed in this embodiment includes vehicle state parameters such as engine oil temperature, current gear position, and current vehicle speed; actuator flow calculation parameters include: steel belt pressure-variable flow parameters, clutch flow parameters, torque converter flow parameters, and steel belt speed ratio flow parameters; system flow includes: flow rate of oil flowing into the actuator control system oil circuit, actual flow rate of oil flowing into the lubrication and cooling system oil circuit, and leakage flow rate of the hydraulic system; wherein, the flow rate of oil flowing into the actuator control system oil circuit includes steel belt pressure-variable flow rate, clutch filling flow rate, torque converter flow rate, and speed ratio change flow rate; and the system flow calculation unit includes: a steel belt pressure-variable flow calculation unit, which is connected to a steel belt current generating component and calculates the steel belt pressure-variable flow rate based on the steel belt pressure-variable flow parameters from the steel belt current generating component; and a clutch flow calculation unit, which is connected to a clutch current generating component. The system comprises the following components: a clutch oil filling flow rate calculation unit (connected to the clutch current generating component and calculating the torque converter flow rate based on the clutch flow parameters from the clutch current generating component); a leakage flow calculation unit (connected to the steel belt current generating component, clutch current generating component, and torque converter current generating component and calculating the hydraulic system leakage flow rate based on pre-inputted engine oil temperature and actuator flow calculation parameters); a lubrication flow calculation unit (obtaining the actual flow rate into the lubrication and cooling system oil circuit by looking up a table based on pre-inputted engine oil temperature, vehicle current gear, and current vehicle speed); and a steel belt speed ratio flow calculation unit (connected to the steel belt current generating component and calculating the speed ratio change flow rate based on the steel belt speed ratio flow parameters from the steel belt current generating component).

[0024] According to another specific embodiment of the present invention, the hydraulic control system of the continuously variable transmission disclosed in this embodiment includes the following parameters for the steel belt pressure-to-flow ratio: the control pressure of the active steel belt and the control pressure of the driven steel belt; the clutch flow parameters include the oil passage volume of the clutch and the target filling time; the torque converter flow parameters include the state of the torque converter, the control pressure of the torque converter, and the lock-up area between the torque converter and the clutch; and the steel belt speed ratio flow parameters include the size of the active steel belt, the size of the driven steel belt, the piston actuation area of ​​the active steel belt, and the piston actuation area of ​​the driven steel belt.

[0025] The present invention discloses a control method for a hydraulic control system of a continuously variable transmission (CVT) as described in the above embodiments, comprising the following steps:

[0026] S1: The hydraulic system acquires vehicle status parameters and actuator flow calculation parameters, and determines the flow rate of the oil flowing through the main oil circuit, the flow rate of the oil flowing into the actuator control system oil circuit, and the leakage flow rate of the hydraulic system based on the vehicle status parameters and actuator flow calculation parameters.

[0027] S2: The hydraulic control system calculates the actual flow rate into the lubrication and cooling system based on the current flow rate of the oil flowing through the main oil circuit from the hydraulic system, the flow rate of the oil flowing through the first oil pump, and the redundant flow rate, and determines the working state of the first oil pump and the second oil pump; wherein, the working state includes a first state in which the first oil pump is working, and a second state in which both the first oil pump and the second oil pump are working.

[0028] S3: Determine whether the actual flow rate of the oil flowing into the lubrication and cooling system circuit in the first state and the second state can meet the required flow rate of the lubrication and cooling system circuit calculated by the flow calculation component.

[0029] If the requirements are met, the oil pump valve control current and the main oil circuit valve control current will be output according to the required flow rate.

[0030] If the conditions are not met, proceed with the following steps:

[0031] If the first oil pump and the second oil pump are currently in the first state, then control the first oil pump and the second oil pump to work in the second state, and output control commands to the main oil circuit pressure calculation unit to increase the flow rate and pressure of the oil flowing through the main oil circuit;

[0032] If the first and second oil pumps are currently in the second state, a speed request message is sent to the engine controller to increase the engine speed.

[0033] The above scheme calculates the actual flow rate of the lubrication and cooling system oil circuit based on the oil flow rate at the outlet of the first oil pump, the flow rate of the steel belt pressure transformer, the clutch filling flow rate, the flow rate of the hydraulic torque converter, the speed ratio change flow rate, and the leakage flow rate of the hydraulic system. This actual flow rate is then compared with the required flow rate of the lubrication and cooling system oil circuit. Since the calculation process for the required flow rate of the lubrication and cooling system oil circuit is relatively simple, and the oil demand of the execution system must be guaranteed during system operation, using whether the demand of the lubrication and cooling system oil circuit can be met as the control benchmark for the hydraulic control system results in faster calculation speed and ensures the normal operation of the execution system. Furthermore, this control method calculates the control current of the oil pump valve control components and the main oil circuit valve control components based on the required flow rate of the execution system and the required lubrication flow rate. The calculated control current is then used to control the hydraulic control system of the continuously variable transmission (CVT) and the engine. This allows the hydraulic system to operate in its most efficient range, reducing hydraulic system energy loss, improving transmission efficiency, and meeting the flow requirements of the execution system under rapid action and extreme conditions. This ensures transmission performance while effectively protecting the transmission and extending its service life.

[0034] According to another specific embodiment of the present invention, in the control method of the hydraulic control system of the continuously variable transmission disclosed in this embodiment, in step S2, if the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is greater than the current flow rate of the oil flowing through the main oil circuit, the working state is a first state; if the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is less than the current flow rate of the oil flowing through the main oil circuit, the working state is a second state; and in the first state, the current flow rate of the oil flowing through the main oil circuit is the oil flow rate at the outlet of the first oil pump; in the second state, the current flow rate of the oil flowing through the main oil circuit is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump.

[0035] According to another specific embodiment of the present invention, the control method of the hydraulic control system of the continuously variable transmission disclosed in this embodiment of the present invention further includes the total displacement of the first oil pump as a vehicle state parameter; and, in the first state, the oil flow rate at the outlet of the first oil pump is calculated according to the following formula:

[0036]

[0037] Where Q1 is the oil flow rate at the outlet of the first oil pump, n is the engine speed, d is the total displacement of the first oil pump, and η is the volumetric efficiency of the first oil pump at different oil temperatures, which is obtained by referring to a table based on the engine speed, main oil circuit pressure, and engine oil temperature; in the second state, the sum of the oil flow rates at the outlets of the first and second oil pumps is calculated according to the following formula:

[0038] Q2=n*d*η

[0039] Where Q2 is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump, n is the engine speed, d is the total displacement of the first oil pump, and η is the volumetric efficiency of the first oil pump at different oil temperatures, which is obtained by looking up a table based on the engine speed, main oil circuit pressure, and engine oil temperature.

[0040] According to another specific embodiment of the present invention, the control method of the hydraulic control system of the continuously variable transmission disclosed in this embodiment calculates the actual flow rate of the lubrication and cooling system oil circuit according to the following formula in the first state:

[0041] Q_slip = Q1 - Q3 - Q4 - Q5 - Q6 - Q7

[0042] Wherein, Qslippery is the actual flow rate of the lubrication and cooling system oil circuit, Q1 is the oil flow rate at the outlet of the first oil pump, Q3 is the steel belt pressure change flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system; and, in the second state, the actual flow rate of the lubrication and cooling system oil circuit is calculated according to the following formula:

[0043] Q_slip = Q2 - Q3 - Q4 - Q5 - Q6 - Q7

[0044] Wherein, Qslippery is the actual flow rate of the lubrication and cooling system oil circuit, Q2 is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump, Q3 is the steel belt pressure change flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system.

[0045] The flow rate of the steel belt pressure changer is obtained by referring to a table based on the rate of change of the control pressure of the active steel belt and the control pressure of the driven steel belt.

[0046] The clutch oil flow rate is calculated using the following formula:

[0047]

[0048] Where Q4 is the clutch oil flow rate, V0 is the clutch oil passage volume, and Tt is the target oil filling time.

[0049] The flow rate of the hydraulic torque converter is calculated using the following formula:

[0050]

[0051] Where Q5 is the flow rate of the hydraulic torque converter. The change in the volume of the hydraulic torque converter in each cycle is obtained by looking up a table based on the state of the hydraulic torque converter, the control pressure of the hydraulic torque converter, and the lock-up area between the hydraulic torque converter and the clutch.

[0052] The flow rate under speed ratio variation is calculated using the following formula:

[0053]

[0054] Where Q6 is the speed ratio change flow rate, and i is the speed ratio between the driving steel belt and the driven steel belt, which is obtained by looking up a table based on the size of the driving steel belt, the size of the driven steel belt, the piston actuation area of ​​the driving steel belt, and the piston actuation area of ​​the driven steel belt.

[0055] An embodiment of the present invention discloses an electronic device, comprising:

[0056] Memory is used to store computer programs, which include program instructions.

[0057] A processor is used to execute program instructions to cause electronic devices to perform the control method of the hydraulic control system of the continuously variable transmission as described in any of the above embodiments.

[0058] The present invention discloses a computer-readable storage medium storing a computer program, the computer program including program instructions, which are executed by an electronic device to cause the electronic device to perform a control method for a hydraulic control system of a continuously variable transmission as described in any of the above embodiments.

[0059] The beneficial effects of this invention are:

[0060] The hydraulic control system for the continuously variable transmission (CVT) provided in this solution takes into account the needs of the actuator control system, lubrication and cooling requirements, and the actual flow rate of the oil pump when controlling the oil pump control valve assembly and the main oil circuit control valve assembly. This allows the hydraulic system to operate in its most efficient range, reducing hydraulic system capacity loss and improving transmission efficiency. It also meets the flow requirements of the actuator system under rapid action and extreme conditions, ensuring transmission performance while effectively protecting the transmission and extending its service life. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the structure of a continuously variable transmission (CVT) in the prior art;

[0062] Figure 2 This is a schematic diagram of the hydraulic system of a continuously variable transmission (CVT) in the prior art;

[0063] Figure 3 This is a schematic diagram of the hydraulic system of the continuously variable transmission provided in an embodiment of the present invention;

[0064] Figure 4 This is a schematic diagram of the hydraulic control system of the continuously variable transmission provided in an embodiment of the present invention;

[0065] Figure 5 This is a flow-current curve of the solenoid valve in the hydraulic control system of the continuously variable transmission provided in this embodiment of the invention;

[0066] Figure 6 This is a schematic diagram of the system flow calculation unit provided in an embodiment of the present invention;

[0067] Figure 7 This is a flowchart illustrating the control method of the hydraulic control system for a continuously variable transmission (CVT) provided in an embodiment of the present invention.

[0068] Figure 8 This is a graph showing the relationship between the dimensions of the active steel belt and the radius of the driven steel belt and the speed ratio, provided in an embodiment of the present invention.

[0069] Explanation of reference numerals in prior art drawings:

[0070] 101. Engine; 102. Engine controller; 103. Transmission controller; 104. Hydraulic system; 105. Torque converter; 106. Clutch; 107. Drive belt;

[0071] 201, 202, Oil pump; 203, Oil pump switching valve; 204, 205, Solenoid valve; 206, Main oil circuit pressure regulating valve; 207, Actuation system oil circuit; 208, Control oil circuit; 209, Lubricating oil circuit; 210, 211, 212, Feedback loop.

[0072] Explanation of reference numerals in the accompanying drawings of this invention:

[0073] 1. Hydraulic control system; 2. Hydraulic system; 3. Gearbox controller; 4. Engine controller; 5. First oil pump; 6. Second oil pump; 7. Main oil circuit; 8. Oil pump switching valve; 9. Switching control valve; 10. Pressure regulating valve; 11. Regulating control valve; 12. Actuation control system oil circuit; 13. Lubrication and cooling system oil circuit; 14. Driving steel belt control component; 15. Driven steel belt control component; 16. Clutch control component; 17. Torque converter control component; 18. Main oil circuit valve control component; 19. Oil pump valve control component; 20. Steel belt current generating component; 21. 22. Clutch current generating unit; 23. Hydraulic torque converter current generating unit; 24. Main oil circuit oil pressure calculation unit; 25. Main oil circuit current generating unit; 26. Flow calculation unit; 27. Oil pump current generating unit; 28. Steel belt pressure-variable flow calculation unit; 29. ​​Clutch flow calculation unit; 30. Hydraulic torque converter flow calculation unit; 31. Leakage flow calculation unit; 32. Lubrication flow calculation unit; 33. Steel belt speed ratio flow calculation unit; 34. System flow calculation unit; 35. Oil pump status determination unit; 36. Oil pump flow calculation unit; 37. Flow demand calculation unit. Detailed Implementation

[0074] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0075] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0076] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0077] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0078] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0079] Example 1:

[0080] To address the issue of low flow control accuracy of the hydraulic pump in the hydraulic system of a continuously variable transmission (CVT) in existing technologies, this embodiment provides a hydraulic control system for a CVT. (Reference) Figure 3 The hydraulic control system 1 is connected to the hydraulic system 2 and the transmission controller 3 of the continuously variable transmission (CVT), respectively. The transmission controller 3 is connected to the vehicle's engine controller 4. The hydraulic system 2 includes an oil pump control valve assembly and a main oil circuit 7. The oil pump control valve assembly is connected to a first oil pump 5 and a second oil pump 6, controlling their operating states. The input end of the main oil circuit 7 is connected to the hydraulic oil chamber, and the output end is connected to the CVT's actuator control system oil circuit 12 and lubrication and cooling system oil circuit 13, respectively. The oil outlets of the first oil pump 5 and the second oil pump 6 are also connected to the main oil circuit 7. Specifically, the hydraulic oil chamber is also known as the oil pan. The input end of the main oil circuit 7 is connected to the oil pan via the first oil pump 5 and the second oil pump 6.

[0081] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, refer to Figure 3 The oil pump control valve assembly includes an oil pump switching valve 8 and a switching control valve 9. The oil pump switching valve 8 is connected to the first oil pump 5 and the second oil pump 6. The switching control valve 9 is connected to the oil pump switching valve 8 via a first control oil circuit, and controls the flow rate and pressure of the oil flowing through the first control oil circuit to control the operating state of the first oil pump 5 and the second oil pump 6. Specifically, both the oil pump switching valve 8 and the switching control valve 9 are solenoid valves.

[0082] More specifically, Figure 3In this configuration, the first oil pump 5 and the second oil pump 6 have an inlet oil passage below and an outlet oil passage above. The inlet oil passage can connect to the oil pan, and the outlet oil flows into the oil pump switching valve 8 and then out of the outlet of the oil pump switching valve 8, connecting to the oil pan. The operating state of the first oil pump 5 and the second oil pump 6 is the state in which the first oil pump 5 or the second oil pump 6 opens or closes the channel from the oil pan to the main oil passage 7. When the oil pump switching valve 8 connects the outlet oil passages of the first oil pump 5 and the second oil pump 6 to the oil pan, the first oil pump 5 and the second oil pump 6 operate in dual-pump mode, jointly supplying oil from the oil pan to the execution control system oil passage 12 and the lubrication and cooling system oil passage 13. When the oil pump switching valve 8 connects the oil outlet of the first oil pump 5 to the oil pan and interrupts the oil flow of the second oil pump 6 from the oil pan, or connects the oil outlet of the second oil pump 6 to the oil pan and interrupts the oil flow of the first oil pump 5 from the oil pan, only the first oil pump 5 or the second oil pump 6 operates in single-pump mode. Specifically, the oil pump switching valve 8 is equipped with a spring and a valve core. By controlling the oil flow and pressure of each oil circuit connected to the oil pump switching valve 8, the force exerted by the spring on the valve core can be controlled, thereby controlling the movement of the valve core inside the oil pump switching valve 8. This allows control of the flow direction of the oil from the first oil pump 5 and the second oil pump 6 after entering the oil pump switching valve 8, thus controlling the operating state of the first oil pump 5 and the second oil pump 6.

[0083] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, a main oil circuit control valve assembly is provided on the main oil circuit 7, and the main oil circuit control valve assembly controls the flow rate and pressure of the oil flowing through the main oil circuit 7.

[0084] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the main oil circuit control valve assembly includes a pressure regulating valve 10 and a regulating control valve 11. The pressure regulating valve 10 regulates the flow rate and pressure of the oil flowing through the main oil circuit 7, and the regulating control valve 11 is connected to the pressure regulating valve 10 via a second control oil circuit. The regulating control valve 11 controls the flow rate and pressure of the oil flowing through the second control oil circuit to control the pressure regulating valve 10. Specifically, both the pressure regulating valve 10 and the regulating control valve 11 are solenoid valves.

[0085] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the hydraulic control system 1 calculates the actual flow rate of the oil flowing into the lubrication and cooling system 13 based on the current flow rate of the oil flowing through the main oil circuit 7 from the hydraulic system 2, the flow rate of the oil flowing into the execution control system oil circuit 12, and the leakage flow rate of the hydraulic system 2. Based on the actual flow rate of the oil flowing into the lubrication and cooling system 13, the preset redundant flow rate, and the required flow rate of the lubrication and cooling system 13, the hydraulic control system 1 controls the oil pump control valve assembly and the main oil circuit control valve assembly, and sends speed request information to the engine controller 4 to control the working state of the first oil pump 5 and the second oil pump 6, the flow rate and pressure of the oil flowing through the main oil circuit 7, and the engine speed.

[0086] By adopting the above solution, since the hydraulic control system 1 considers the needs of the execution control system, the lubrication and cooling needs, and the actual flow rate of the oil pump when controlling the oil pump control valve assembly and the main oil circuit control valve assembly, the hydraulic system 2 can be kept in the most efficient working range. This not only reduces the capacity loss of the hydraulic system 2 and improves the efficiency of the gearbox, but also meets the flow requirements of the execution system under rapid action and extreme conditions, ensuring the performance of the gearbox while protecting the gearbox and extending its service life.

[0087] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the actuator control system oil circuit 12 is connected to the actuator control system of the CVT. The actuator control system refers to the collection of components in the CVT capable of controlling vehicle speed. In this embodiment, the actuator control system of the CVT includes a driving steel belt, a driven steel belt, a clutch, and a torque converter. The actuator control system oil circuit 12 includes a driving steel belt control oil circuit, a driven steel belt control oil circuit, a clutch control oil circuit, and a torque converter control oil circuit. The actuator control system oil circuit 12 corresponds to each component in the actuator system; by controlling the pressure and flow rate of the oil in the actuator control system oil circuit 12, the operating state of each component can be controlled.

[0088] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the input end of the active steel belt control oil circuit is connected to the output end of the main oil circuit 7, and the output end is connected to the active steel belt. An active steel belt control valve is also provided on the active steel belt control oil circuit. This active steel belt control valve is used to control the pressure and flow rate of the oil in the active steel belt control oil circuit. The input end of the driven steel belt control oil circuit is connected to the output end of the main oil circuit 7, and the output end is connected to the driven steel belt. A driven steel belt control valve is also provided on the driven steel belt control oil circuit. This driven steel belt control valve is used to control the pressure and flow rate of the oil in the driven steel belt control oil circuit. The input end of the clutch control oil circuit is connected to the output end of the main oil circuit 7, and the output end is connected to the clutch. A clutch control valve is also provided on the clutch control oil circuit. This clutch control valve is used to control the pressure and flow rate of the oil in the clutch control oil circuit. The input end of the hydraulic torque converter control oil circuit is connected to the output end of the main oil circuit 7, and the output end is connected to the hydraulic torque converter. A hydraulic torque converter control valve is also provided on the hydraulic torque converter control oil circuit. This hydraulic torque converter control valve is used to control the pressure and flow rate of the oil in the hydraulic torque converter control oil circuit. It should be noted that the driving steel belt control valve, driven steel belt control valve, clutch control valve, and hydraulic torque converter control valve are all solenoid valves, and their structure and control method are no different from those of solenoid valves in existing technology.

[0089] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the hydraulic control system 1 includes a valve control unit, an execution control system state parameter acquisition unit, and a control current generation unit. The valve control unit is used to control the control valves of various components in the execution system, including an actuator valve control assembly, a main oil circuit valve control assembly 18, and an oil pump valve control assembly 19. The actuator valve control assembly is connected to each control valve in the oil circuit of the execution control system to control the state of each control valve. Specifically, the actuator valve control assembly includes: a driving steel belt control assembly 14, a driven steel belt control assembly 15, a clutch control assembly 16, and a torque converter control assembly 17. The driving steel belt control assembly 14 is connected to the driving steel belt control valve and controls its state. The driven steel belt control assembly 15 is connected to the driven steel belt control valve and controls its state. The clutch control assembly 16 is connected to the clutch control valve and controls its state. The torque converter control assembly 17 is connected to the torque converter control valve and controls its state. The main oil circuit valve control component 18 is connected to the main oil circuit control valve assembly to control the state of the regulating control valve 11 in the main oil circuit control valve assembly. The oil pump valve control component 19 is connected to the oil pump control valve assembly to control the state of the switching control valve 9 in the oil pump control valve assembly.

[0090] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the execution control system state parameter acquisition unit is connected to the transmission controller 3 and the execution control system of the continuously variable transmission respectively, acquires the execution control system state parameters from the execution control system, and sends the execution control system state parameters to the transmission controller 3.

[0091] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the control current generating unit includes an actuator current generating component, a main oil circuit current generating component, and an oil pump current generating component that are communicatively connected to each other. The actuator current generating component is communicatively connected to the transmission controller 3 and receives execution control system status parameters from the transmission controller 3. Specifically, the actuator current generating component includes: a steel belt current generating component 20, a clutch current generating component 21, and a torque converter current generating component 22. The actuator control current includes a driving steel belt control current, a driven steel belt control current, a clutch control current, and a torque converter control current. The steel belt current generating component 20 is used to calculate the driving steel belt control current controlling the driving steel belt control component 14 and the driven steel belt control current controlling the driven steel belt control component 15. The clutch current generating component 21 is used to calculate the clutch control current controlling the clutch control component 16. The torque converter current generating component 22 is used to calculate the torque converter control current controlling the torque converter control component 17.

[0092] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the actuator current generating component is connected to the actuator valve control component. It calculates the target control pressure of the actuator based on pre-input pressure control requirements, and obtains the actuator control current according to a preset first current generation rule based on the target control pressure. The actuator control current is then output to the actuator valve control component to control the states of the driving steel belt control valve, the driven steel belt control valve, the clutch control valve, and the torque converter control valve. Specifically, the pressure control requirements include: steel belt pressure control requirements, clutch pressure control requirements, and torque converter pressure control requirements. More specifically, the steel belt pressure control requirements include the vehicle's pedal opening, the CVT's driving pulley speed, the CVT's driven pulley speed, and the engine torque. The clutch pressure control requirements include the vehicle's pedal opening, the engine speed, the CVT's turbine speed, and the vehicle's current gear. The torque converter pressure control requirements include the vehicle's pedal opening, the engine speed, the CVT's turbine speed, and the current vehicle speed.

[0093] Furthermore, the hydraulic control system of the continuously variable transmission (CVT) according to the present invention also includes a pressure control demand acquisition unit. This unit is connected to the transmission controller 3 and the CVT's execution control system, respectively, to acquire pressure control demands from the execution control system and send these demands to the transmission controller 3. The transmission controller 3 is also connected to an actuator current generating component, sending the pressure control demands to it. In this embodiment, the pressure control demand acquisition unit includes various sensors for measuring the pressure control demands. For example, a pedal sensor for measuring pedal opening, a wheel speed sensor for measuring the speed of the driving and driven pulleys, a torque sensor for measuring engine torque, a speed sensor for measuring engine speed, a speed sensor for measuring turbine speed, a vehicle speed sensor for measuring vehicle speed, and a gear sensor for measuring the current gear. After each sensor measures the aforementioned pressure control demands, the measurement results can be sent to the transmission controller 3, and then from the transmission controller 3 to the belt current generating component 20, the clutch current generating component 21, and the torque converter current generating component 22.

[0094] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the main oil circuit current generating component is connected to the main oil circuit valve control component 18. It calculates the main oil circuit valve target control pressure based on the actuator target control pressure from the actuator current generating component and the pressure demand information from the oil pump current generating component. It then obtains the main oil circuit valve control current according to the main oil circuit valve target control pressure using a first current generation rule, and outputs the main oil circuit valve control current to the main oil circuit valve control component 18 to control the state of the main oil circuit control valve assembly. Specifically, the actuator target control pressure includes the driving steel belt control pressure, the driven steel belt control pressure, the clutch control pressure, and the hydraulic torque converter control pressure. With this approach, since the target control pressure of the actuator from the actuator current generating component and the pressure demand information from the oil pump current generating component are considered when calculating the control current of the main oil circuit valve, the target control pressure required by each actuator and the control pressure required by the oil pump are fully considered when controlling the oil pressure and oil flow of the main oil circuit 7. This makes the accuracy of the current calculated for controlling the oil pressure and oil flow of the main oil circuit 7 higher.

[0095] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the oil pump current generating component is connected to the oil pump valve control component 19. Based on the pre-input flow control requirements, the actuator target control pressure from the actuator current generating component, the actuator control system state parameters, and the main oil circuit valve target control pressure from the main oil circuit current generating component, the target control flow of the oil pump valve is calculated. The oil pump valve control current is obtained according to the target control flow of the oil pump valve using a preset second current generation rule, and the oil pump valve control current is output to the oil pump valve control component 19 to control the state of the oil pump control valve assembly. In this manner, since the flow control requirements of the entire hydraulic system 2, the actuator target control pressure from the actuator current generating component, and the main oil circuit valve target control pressure from the main oil circuit current generating component are considered when calculating the oil pump valve control current, the target control flow of the oil pump valve is calculated. This ensures that when the main oil circuit valve control component 18 controls the switching control valve 9, the target control pressure required by each actuator and the main oil circuit valve target control pressure are fully considered, resulting in a higher accuracy of the calculated oil pump valve control current.

[0096] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the belt current generating component 20 calculates the active belt control pressure and the driven belt control pressure according to the belt pressure control requirements from the transmission controller 3, and outputs active belt control current and driven belt control current to the active belt control component 14 and the driven belt control component 15 respectively according to the active belt control pressure and the driven belt control pressure, based on a first current generation rule, so as to control the active belt control component 14 and the driven belt control component 15 respectively according to the active belt control current and the driven belt control current. The clutch current generating component 21 calculates the clutch control pressure according to the clutch pressure control requirements from the transmission controller 3, and outputs the clutch control current to the clutch control component 16 according to the clutch control pressure, based on a first current generation rule, so as to control the clutch control component 16 according to the clutch control current. The torque converter current generating component 22 calculates the torque converter control pressure based on the torque converter pressure control requirements from the transmission controller 3, and outputs a torque converter control current to the torque converter control component 17 according to a first current generation rule, thereby controlling the torque converter control component 17 based on the torque converter control current. Specifically, the preset first current generation rule is: the pressure-current curve of the solenoid valve obtained through calibration. More specifically, different models of solenoid valves may have different currents under the same pressure, that is, the pressure-current curves of the solenoid valves may also be different. Specifically, a large number of experiments need to be conducted on each type of solenoid valve to measure its current value under different pressures, and then a solenoid valve pressure-current curve is fitted and stored in the steel belt current generating component 20, the clutch current generating component 21, and the torque converter current generating component 22. Once the steel strip current generating component 20, the clutch current generating component 21, and the hydraulic torque converter current generating component 22 calculate the actuator target control pressure based on the input pressure requirement, they can find the current value corresponding to the solenoid valve pressure-current curve based on the calculated actuator target control pressure and output it to the corresponding actuator valve control component. It should be noted that solenoid valve pressure and current are generally inversely proportional.

[0097] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the main oil circuit current generating component includes a main oil circuit pressure calculation component 23 and a main oil circuit current generating component 24. The signal input terminal of the main oil circuit pressure calculation component 23 is connected to the oil pump current generating component and the actuator current generating component, respectively, and the signal output terminal is connected to the signal input terminal of the main oil circuit current generating component 24. The signal output terminal of the main oil circuit current generating component 24 is connected to the main oil circuit valve control component 18. The main oil circuit pressure calculation component 23 calculates the main oil circuit valve target control pressure based on the actuator target control pressure from the actuator current generating component, the pressure demand information from the oil pump current generating component, and the redundant flow. The main oil circuit current generating component 24 obtains the main oil circuit valve control current according to the main oil circuit valve target control pressure from the main oil circuit pressure calculation component 23 and a first current generation rule, and outputs the main oil circuit valve control current to the main oil circuit valve control component 18. Specifically, the preset redundant flow rate range is 0.8L / min to 1.2L / min, for example, it could be 0.8L / min, 0.95L / min, 1.1L / min, 1.2L / min, or other values ​​within this range. It should be noted that redundant flow rate refers to adding a certain value to the actual oil flow rate data when calculating the target control pressure of the main oil circuit valves to compensate for oil losses during transmission. This approach, by considering redundant flow rate when calculating the target control pressure of the main oil circuit valves, makes the calculated target control pressure more accurate, thereby enabling more precise control of the oil pressure and flow rate in the main oil circuit 7, and ultimately improving the transmission's operating efficiency.

[0098] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the transmission controller 3 is connected to the vehicle controller to obtain the flow control requirements from the vehicle controller. The oil pump current generating component includes a flow calculation component 25 and an oil pump current generating component 26.

[0099] Furthermore, in the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the signal input terminal of the flow calculation unit 25 is connected to the main oil circuit pressure calculation unit 23, the actuator current generating component, and the transmission controller 3, respectively; the output terminal is connected to the signal input terminal of the oil pump current generating unit 26; and the signal output terminal of the oil pump current generating unit 26 is connected to the oil pump valve control unit 19. The flow calculation unit 25 calculates the target control flow of the oil pump valve based on the flow control requirements from the transmission controller 3, the actuator target control pressure from the actuator current generating component, the state parameters of the actuator control system, and the main oil circuit valve target control pressure from the main oil circuit pressure calculation unit 23. The oil pump current generating unit 26 obtains the oil pump valve control current according to the target control flow of the oil pump valve from the flow calculation unit 25 using a second current generation rule, and outputs the oil pump valve control current to the oil pump valve control unit 19. Specifically, the flow control requirements include engine speed, engine oil temperature, current vehicle speed, and the vehicle's current gear. The status parameters of the actuator control system include: the speed ratio of the driving and driven steel belts, the rate of change of the speed ratio of the driving and driven steel belts, the clutch status, and the torque converter status. More specifically, it also includes an actuator flow calculation parameter acquisition unit, which is connected to both the transmission controller 3 and the continuously variable transmission's (CVT) actuator control system to acquire actuator flow calculation parameters from the actuator control system and send these parameters to the transmission controller 3. The transmission controller 3 is connected to the vehicle's overall controller to acquire vehicle status parameters from the overall controller. Specifically, the vehicle status parameters include engine oil temperature, the vehicle's current gear, and the current vehicle speed. The engine oil temperature is measured by an oil temperature sensor, the current gear by a gear position sensor, and the current vehicle speed by a vehicle speed sensor. Furthermore, the actuator flow calculation parameters include: steel belt pressure converter flow parameters, clutch flow parameters, torque converter flow parameters, and steel belt speed ratio flow parameters. The steel belt pressure-transformer flow parameters include the target output pressure for the active steel belt control component 14 and the driven steel belt control component 15, i.e., the active steel belt control pressure and the driven steel belt control pressure. The clutch flow parameters include the clutch oil passage volume and the target filling time. The torque converter flow parameters include the torque converter state, the target output pressure for the torque converter, and the lock-up area between the torque converter and the clutch. The steel belt speed ratio flow parameters include the dimensions of the active steel belt, the dimensions of the driven steel belt, the piston actuation area of ​​the active steel belt, and the piston actuation area of ​​the driven steel belt. In this embodiment, the actuator flow calculation parameter acquisition unit includes sensors for measuring the actuator flow calculation parameters, communication elements for directly acquiring the target output pressure stored in each current-generating component, and related data processing and calculation elements.For example, a communication element that obtains the target output pressure from the steel belt current generating component 20; and a processor that calculates the target filling time of the clutch. Some parameters in the actuator flow calculation parameters, such as the dimensions of the driving steel belt, the driven steel belt, the piston actuation area of ​​the driving steel belt, and the piston actuation area of ​​the driven steel belt, can be obtained by consulting the product manual.

[0100] It should be noted that the preset second current generation rule is based on the calibrated solenoid valve flow-current curve. Different models of solenoid valves may have different currents at the same flow rate, meaning their flow-current curves may also differ. Specifically, extensive experiments are needed for each type of solenoid valve to measure its current value at different flow rates, then a solenoid valve flow-current curve is fitted and stored in the oil pump current generation component 26. When the oil pump current generation component 26 calculates the oil pump valve control current based on the target control flow rate from the flow calculation component 25, it can find the current value corresponding to the solenoid valve flow-current curve based on the calculated oil pump valve control current and output it to the oil pump valve control component 19. In this embodiment, the calibrated solenoid valve flow-current curve is as follows: Figure 5 As shown, flow rate and current are basically inversely proportional.

[0101] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, refer to Figure 6The flow calculation unit 25 includes a system flow calculation unit 33, an oil pump status determination unit 34, an oil pump flow calculation unit 35, and a flow demand calculation unit 36. Specifically, the signal input terminal of the system flow calculation unit 33 is connected to the transmission controller 3, and calculates the system flow based on vehicle status parameters from the transmission controller 3 and actuator flow calculation parameters. The signal input terminal of the oil pump status determination unit 34 is connected to the first oil pump 5 to obtain the oil flow rate of the first oil pump 5. The input terminal of the oil pump flow calculation unit 35 is connected to the output terminal of the oil pump status determination unit 34, the output terminal of the system flow calculation unit 33, and the output terminal of the main oil circuit pressure calculation unit 23, and calculates the current flow rate of the oil flowing through the main oil circuit 7 based on the oil flow rate of the first oil pump 5 from the oil pump status determination unit 34, the system flow rate from the system flow calculation unit 33, and the redundant flow rate from the main oil circuit pressure calculation unit 23. The signal input terminal of the flow demand calculation unit 36 ​​is connected to the signal output terminal of the system flow calculation unit 33 and the signal output terminal of the oil pump flow calculation unit 35, respectively. Based on the system flow from the system flow calculation unit 33 and the current flow of oil flowing through the main oil circuit 7 from the oil pump flow calculation unit 35, the actual flow into the lubrication and cooling system oil circuit 13 is calculated. Based on the actual flow into the lubrication and cooling system oil circuit 13 and the required flow of the lubrication and cooling system oil circuit 13, boost information, flow demand information and speed request information are generated. Based on the boost information, the pressure of the oil flowing through the main oil circuit 7 is controlled; based on the flow demand information, the flow of the oil flowing through the main oil circuit 7 is controlled; and based on the speed request information, the engine speed is controlled.

[0102] Specifically, the system flow includes: the flow rate of oil flowing into the actuator control system oil circuit 12, the actual flow rate flowing into the lubrication and cooling system oil circuit 13, and the leakage flow rate of the hydraulic system 2. Among them, the flow rate of oil flowing into the actuator control system oil circuit 12 includes the steel belt pressure change flow rate, the clutch filling flow rate, the hydraulic torque converter flow rate, and the speed ratio change flow rate.

[0103] Furthermore, in the hydraulic control system of the continuously variable transmission according to the present invention, the system flow calculation unit 33 includes a steel belt pressure converter flow calculation unit 27, a clutch flow calculation unit 28, a hydraulic torque converter flow calculation unit 29, a leakage flow calculation unit 30, a lubrication flow calculation unit 31, and a steel belt speed ratio flow calculation unit 32.

[0104] Specifically, the steel strip voltage transformer flow calculation unit 27 is connected to the steel strip current generating component 20, and calculates the steel strip voltage transformer flow based on the steel strip voltage transformer flow parameters from the steel strip current generating component 20.

[0105] More specifically, the strip pressure-to-flow rate calculation unit 27 receives the target output pressures calculated by the strip current generating component 20 for controlling the active strip control component 14 and the driven strip control component 15, respectively. It then calculates the rate of change of the target output pressure for each component, and obtains the strip pressure-to-flow rate by referring to the table below (target output pressure rate of change, actual pressure - strip pressure-to-flow rate). It should be noted that the specific data for the strip pressure-to-flow rate in Table 1 can be obtained through extensive experimental calibration. Specifically, the strip pressure-to-flow rate for each component is experimentally measured under different pressures and target output pressure rates. This data is then processed, such as by averaging and filtering out abnormal data, to form the table (target output pressure rate of change, actual pressure - strip pressure-to-flow rate). After calculating the rate of change of the target output pressure for each component and measuring their actual pressures, the strip pressure-to-flow rate is obtained by referring to Table 1. It should also be noted that steel strip pressure-varying flow rate refers to the flow rate caused by pressure changes.

[0106] Table 1

[0107]

[0108] The clutch flow calculation unit 28 is connected to the clutch current generating component 21 and calculates the clutch oil flow rate based on the clutch flow parameters from the clutch current generating component 21. Specifically, the clutch oil flow rate is calculated according to the following formula:

[0109]

[0110] Where Q4 is the clutch oil flow rate, V0 is the clutch oil passage volume, and Tt is the target oil filling time.

[0111] The torque converter flow calculation unit 29 is connected to the torque converter current generating component 22, and calculates the torque converter flow rate based on the torque converter flow rate parameters from the torque converter current generating component 22. Specifically, the torque converter flow rate is calculated according to the following formula:

[0112]

[0113] Where Q5 is the flow rate of the hydraulic torque converter. The change in the volume of the hydraulic torque converter in each cycle is obtained by looking up a table based on the state of the hydraulic torque converter, the control pressure of the hydraulic torque converter, and the lock-up area between the hydraulic torque converter and the clutch. It should be noted that the data on the change in the volume of the hydraulic torque converter in each cycle can be obtained through extensive experimental calibration. Specifically, the flow rate of the hydraulic torque converter is measured under different states, different control pressures, and different lock-up areas between the hydraulic torque converter and the clutch. This data is then processed through methods such as averaging and filtering out abnormal data to form a table. After measuring the state of the hydraulic torque converter, the control pressure, and the lock-up area between the hydraulic torque converter and the clutch, the change in the volume of the hydraulic torque converter in each cycle, which is the flow rate of the hydraulic torque converter, is obtained by looking up the table.

[0114] The leakage flow calculation unit 30 is connected to the steel belt current generating component 20, the clutch current generating component 21, and the hydraulic torque converter current generating component 22, respectively. It calculates the leakage flow of the hydraulic system 2 based on pre-inputted engine oil temperature and actuator flow calculation parameters. Specifically, the leakage flow calculation unit 30 converts the target pressure signals from the steel belt current generating component 20, the clutch current generating component 21, and the hydraulic torque converter current generating component 22 into control currents, and then obtains the leakage flow at different oil temperatures and currents using an oil temperature-current-leakage flow table. More specifically, the oil temperature-current-leakage flow table is obtained through calibration, i.e., by experimentally measuring the leakage flow of the hydraulic system 2 at different engine oil temperatures and different target currents for each actuator, and then processing the data, such as averaging and filtering abnormal data, to form a table. The leakage flow of the hydraulic system 2 is then obtained by looking up the table after measuring the engine oil temperature and different target currents for each actuator.

[0115] The lubrication flow calculation unit 31 obtains the actual flow rate of oil flowing into the lubrication and cooling system 13 by looking up a table based on the pre-inputted engine oil temperature, vehicle current gear, and current vehicle speed. Specifically, the lubrication flow calculation unit 31 pre-stores Table 2, which is obtained through calibration. In Table 2, V1 and V2 represent vehicle speed, P represents parking gear, N represents neutral gear, D represents forward gear, and R represents reverse gear. The actual flow rate of oil flowing into the lubrication and cooling system 13 is obtained through extensive experiments. That is, the actual flow rate of oil flowing into the lubrication and cooling system 13 at different engine oil temperatures, different gears, and different vehicle speeds is experimentally measured. Then, after data processing such as averaging and filtering out abnormal data, Table 2 is generated. After measuring the engine oil temperature, vehicle current gear, and current vehicle speed, the actual flow rate of oil flowing into the lubrication and cooling system 13 can be obtained by looking up Table 2.

[0116] Table 2

[0117]

[0118] The steel belt speed ratio flow rate calculation unit 32 is connected to the steel belt current generating component 20, and calculates the speed ratio change flow rate based on the steel belt speed ratio flow rate parameters from the steel belt current generating component 20. Specifically, the speed ratio change flow rate is calculated according to the following formula:

[0119]

[0120] Where Q6 is the speed ratio variation flow rate, and i is the speed ratio between the driving and driven steel belts, which is obtained by looking up a table based on the dimensions of the driving and driven steel belts, the piston actuation area of ​​the driving and driven steel belts. Specifically, refer to... Figure 8 Based on the dimensions of the driving and driven steel belts, the relationship between the speed ratio and the radius can be determined. Then, based on the target speed ratio change rate... The speed ratio change flow rate can be calculated from the known actuator and driven steel belt piston actuation areas. Figure 8 In this context, PS radius is the radius of the pulley corresponding to the driving steel belt, and SS is the radius of the pulley corresponding to the driven steel belt.

[0121] Example 2:

[0122] Based on the hydraulic control system of the continuously variable transmission (CVT) described above, this embodiment provides a control method for the hydraulic control system of a CVT. Specifically, refer to... Figure 7 The control method of the hydraulic control system of the continuously variable transmission provided in this embodiment includes the following steps:

[0123] S1: The hydraulic system acquires vehicle status parameters and actuator flow calculation parameters, and determines the flow rate of the oil flowing through the main oil circuit, the flow rate of the oil flowing into the actuator control system oil circuit, and the leakage flow rate of the hydraulic system based on the vehicle status parameters and actuator flow calculation parameters.

[0124] S2: The hydraulic control system calculates the actual flow rate into the lubrication and cooling system based on the current flow rate of the oil flowing through the main oil circuit from the hydraulic system, the flow rate of the oil flowing through the first oil pump, and the redundant flow rate, and determines the working state of the first oil pump and the second oil pump; wherein, the working state includes a first state in which the first oil pump is working, and a second state in which both the first oil pump and the second oil pump are working.

[0125] S3: Determine whether the actual flow rate of the oil flowing into the lubrication and cooling system circuit in the first state and the second state can meet the required flow rate of the lubrication and cooling system circuit calculated by the flow calculation component.

[0126] If satisfied, the control current for the oil pump valves and the control current for the main oil circuit valves will be output according to the required flow rate.

[0127] If the conditions are not met, proceed with the following steps:

[0128] If the first oil pump and the second oil pump are currently in the first state, then control the first oil pump and the second oil pump to work in the second state, and output control commands to the main oil circuit pressure calculation unit to increase the flow rate and pressure of the oil flowing through the main oil circuit;

[0129] If the first and second oil pumps are currently in the second state, a speed request message is sent to the engine controller to increase the engine speed.

[0130] Specifically, refer to Figure 3 In the first state, only the oil outlet of the first oil pump 5 is connected to the oil pan, while the oil supply of the second oil pump 6 is disconnected from the oil pan. In the second state, the oil outlets of both the first oil pump 5 and the second oil pump 6 are connected to the oil pan. It should be noted that this embodiment is merely illustrative, using the example of only the first oil pump 5's oil outlet being connected to the oil pan and the second oil pump 6's oil supply being disconnected. In fact, the first state is the state of single-pump operation; if the second oil pump 6's oil outlet is connected to the oil pan and the first oil pump 5's oil supply is disconnected, this also falls under the category of the first state. It should be noted that the control current for the oil pump valve control component and the control current for the main oil circuit valve control component refer to the current used to control the oil pump valve control component and the current used to control the main oil circuit valve control component, respectively.

[0131] More specifically, the various parameters involved in this embodiment, such as vehicle status parameters, actuator flow calculation parameters, and various algorithms, such as the flow rate of oil flowing through the main oil circuit, the flow rate of oil flowing into the execution control system oil circuit, and the leakage flow rate of the hydraulic system, are all described in detail in Embodiment 1, and will not be repeated in this embodiment.

[0132] Furthermore, in the control method of the hydraulic control system of the continuously variable transmission according to the present invention, in step S2, if the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is greater than the current flow rate of the oil flowing through the main oil circuit, the operating state is the first state; if the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is less than the current flow rate of the oil flowing through the main oil circuit, the operating state is the second state. Furthermore, in the first state, the current flow rate of the oil flowing through the main oil circuit is the oil flow rate at the outlet of the first oil pump; in the second state, the current flow rate of the oil flowing through the main oil circuit is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump.

[0133] In other words, the method for determining the first or second state in this embodiment is as follows: if the flow rate of the oil in the first oil pump 5 minus the redundant flow rate is greater than the current flow rate of the oil flowing through the main oil circuit, it means that only the first oil pump 5 is working at this time; if the flow rate of the oil in the first oil pump 5 minus the redundant flow rate is less than the current flow rate of the oil flowing through the main oil circuit, it means that the second state of dual-pump oil supply is in effect.

[0134] Furthermore, in the control method of the hydraulic control system of the continuously variable transmission according to the present invention, the vehicle state parameters also include the total displacement of the first oil pump. And, in the first state, the oil flow rate at the outlet of the first oil pump is calculated according to the following formula:

[0135]

[0136] Where Q1 is the oil flow rate at the outlet of the first oil pump, n is the engine speed, d is the total displacement of the first oil pump, and η is the volumetric efficiency of the first oil pump at different oil temperatures, which is obtained by looking up a table based on the engine speed, main oil circuit pressure, and engine oil temperature.

[0137] In the second state, the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump is calculated according to the following formula:

[0138] Q2=n*d*η

[0139] Where Q2 is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump, n is the engine speed, d is the total displacement of the first oil pump, and η is the volumetric efficiency of the first oil pump at different oil temperatures, which is obtained by looking up a table based on the engine speed, main oil circuit pressure, and engine oil temperature.

[0140] It should be noted that the volumetric efficiency of the first oil pump can be obtained from the speed, pressure, and oil temperature-volumetric efficiency table, which was calibrated through numerous experiments. Specifically, the volumetric efficiency of the first oil pump is calculated under different engine speeds, main oil circuit pressures, and engine oil temperatures. Then, through specific data processing steps, the speed, pressure, and oil temperature-volume efficiency table is generated. After each measurement of the engine speed, main oil circuit pressure, and engine oil temperature, the volumetric efficiency of the first oil pump can be obtained by looking up the table.

[0141] Furthermore, in the control method of the hydraulic control system of the continuously variable transmission according to the present invention, in the first state, the actual flow rate of the lubrication and cooling system oil circuit is calculated according to the following formula:

[0142] Q_slip = Q1 - Q3 - Q4 - Q5 - Q6 - Q7

[0143] Wherein, Q_slippery is the actual flow rate of the lubrication and cooling system oil circuit, Q1 is the oil flow rate at the outlet of the first oil pump, Q3 is the steel belt pressure change flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system.

[0144] Furthermore, in the control method of the hydraulic control system of the continuously variable transmission according to the present invention, in the second state, the actual flow rate of the lubrication and cooling system oil circuit is calculated according to the following formula:

[0145] Q_slip = Q2 - Q3 - Q4 - Q5 - Q6 - Q7

[0146] Wherein, Qslippery is the actual flow rate of the lubrication and cooling system oil circuit, Q2 is the sum of the oil flow rates at the outlets of the first and second oil pumps, Q3 is the steel belt pressure-variable flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system. The steel belt pressure-variable flow rate is obtained by looking up a table based on the rate of change of the target output pressure of the driving and driven steel belt control components. The algorithm for the steel belt pressure-variable flow rate has been described in detail in Example 1 and will not be repeated in this example.

[0147] It should also be noted that the algorithms for clutch oil flow rate, torque converter flow rate, and speed ratio change flow rate are also described in detail in Example 1.

[0148] Furthermore, in the control method of the hydraulic control system of the continuously variable transmission (CVT) according to the present invention, the actual flow rate of the lubrication and cooling system oil circuit is calculated based on the oil flow rate at the outlet of the first oil pump, the steel belt pressure change flow rate, the clutch filling flow rate, the hydraulic torque converter flow rate, the speed ratio change flow rate, and the leakage flow rate of the hydraulic system. The actual flow rate of the lubrication and cooling system oil circuit is then compared with the required flow rate of the lubrication and cooling system oil circuit. Since the calculation process for the required flow rate of the lubrication and cooling system oil circuit is relatively simple, and the oil demand of the execution system needs to be guaranteed during system operation, using whether the demand of the lubrication and cooling system oil circuit can be met as the control benchmark for the hydraulic control system results in faster calculation speed and ensures the normal operation of the execution system. Moreover, this control method calculates the control current of the oil pump valve control component and the control current of the main oil circuit valve control component based on the required flow rate of the execution system and the flow rate required for lubrication. Based on the calculated control current, the hydraulic control system of the CVT and the engine are controlled, allowing the hydraulic system to operate in its most efficient range. This reduces hydraulic system energy loss, improves transmission efficiency, and meets the flow requirements of the execution system under rapid action and extreme conditions, ensuring transmission performance while effectively protecting the transmission and extending its service life.

[0149] Example 3:

[0150] Based on the control method of the hydraulic control system of the continuously variable transmission (CVT) described above, this embodiment provides a specific control method of the hydraulic control system of the CVT.

[0151] refer to Figure 3 and Figure 4 The oil pump valve control component 19, main oil circuit valve control component 18, active steel belt control component 14, driven steel belt control component 15, clutch control component 16, and torque converter control component 17 respectively receive control currents calculated by the solenoid valve pressure-current curves from the oil pump current generating component 26, main oil circuit current generating component 24, steel belt current generating component 20, clutch current generating component 21, and torque converter current generating component 22, and respectively control the switching control valve 9, regulating control valve 11, active steel belt control valve, driven steel belt control valve, clutch control valve, and torque converter control valve. Among them, the steel belt current generating component 20, clutch current generating component 21, and torque converter current generating component 22 calculate the target control pressure of the actuator according to the steel belt pressure control requirements, clutch pressure control requirements, and torque converter pressure control requirements, respectively. The main oil circuit pressure calculation unit 23 receives the target control pressure from the steel belt current generating unit 20, the clutch current generating unit 21, and the hydraulic torque converter current generating unit 22, as well as the target control flow and pressure demand information of the oil pump valves calculated by the flow calculation unit 25. It then performs comprehensive processing, for example, maximizing all pressure requests and adding a certain amount of redundant flow based on operating conditions, to calculate the final target control pressure of the main oil circuit valves, which is then sent to the main oil circuit current generating unit 24. The main oil circuit current generating unit 24 then calculates the main oil circuit valve control current using the solenoid valve pressure-current curve and sends it to the main oil circuit valve control unit 18.

[0152] The flow calculation unit 25 calculates the target control flow of the oil pump valve based on the engine speed, engine oil temperature, current vehicle speed, and current gear position from the transmission controller 3, the actuator target control pressure from the actuator current generation component, the speed ratio of the driving steel belt and the driven steel belt, the speed ratio change rate of the driving steel belt and the driven steel belt, the clutch status, the torque converter status, and the main oil circuit valve target control pressure from the main oil circuit pressure calculation unit 23. The oil pump valve target control flow is then input to the oil pump current generation unit 26, and the oil pump valve control current is obtained from the solenoid valve flow-current curve. Finally, the oil pump valve control current is output to the oil pump valve control unit 19.

[0153] Structural reference of flow calculation component 25 Figure 6As shown, the system flow calculation unit 33 integrates the steel belt pressure transformer flow calculation unit 27, the clutch flow calculation unit 28, the hydraulic torque converter flow calculation unit 29, the leakage flow calculation unit 30, the lubrication flow calculation unit 31, and the steel belt speed ratio flow calculation unit 32. After the oil pump status determination unit 34 determines the operating status of the first oil pump 5 and the second oil pump 6, this flow calculation component 25 and the oil pump flow calculation unit 35 together input the data to the flow demand calculation unit 36. The flow demand calculation unit 36 ​​calculates the information on the increase in main oil circuit pressure, the required flow rate, and the requested speed. Based on these information, it controls the operating status of the first oil pump 5 and the second oil pump 6, the flow rate and pressure of the oil flowing through the main oil circuit 7, and the engine speed.

[0154] After receiving the target control pressure signal and the actual pressure signal of the main and driven cylinders from the steel strip current generating component 20, the steel strip pressure-transformer flow calculation unit 27 calculates the target pressure change rate and then looks up the table to obtain the flow rate caused by the pressure change, i.e., the steel strip pressure-transformer flow rate.

[0155] The clutch flow calculation unit 28 calculates the clutch oil flow rate based on signals such as the clutch status and pre-charge time from the clutch current generating component 21. Specifically, the clutch flow rate calculation method involves knowing the volume V0 of the clutch chamber and oil passage, and the clutch pressure control / torque converter pressure control module informing the target time for this oil filling control; thus, the clutch oil flow rate can be determined. The formula is as follows:

[0156] The hydraulic torque converter flow calculation unit 29 calculates the hydraulic torque converter flow rate based on signals such as the hydraulic torque converter status and command pressure received from the hydraulic torque converter current generating component 22. Specifically, the hydraulic torque converter flow rate calculation method uses the relationship between pressure and the deformation of the hydraulic torque converter lock-up clutch, along with the lock-up area, to obtain the volume change in each cycle; this volume change is the hydraulic torque converter flow rate. The formula is as follows: Where Q5 is the flow rate of the hydraulic torque converter. This represents the change in the volume of the hydraulic torque converter during each cycle. Where Q4 is the clutch oil flow rate, V0 is the clutch oil passage volume, and Tt is the target oil filling time.

[0157] The leakage flow calculation unit 30 converts the target pressure of each pressure control loop into the target current based on the oil temperature signal and the target pressure signal of each module, and then calculates the leakage flow under different temperatures and currents by looking up the table.

[0158] The lubrication flow calculation unit 31 calculates the lubrication flow rate 421 by looking up a table.

[0159] The steel belt speed ratio flow calculation unit 32 can determine the relationship between the speed ratio and radius based on the dimensions of the steel belt. Then, based on the target speed ratio change rate and the known actuator areas of the driving and driven steel belt pistons, the speed ratio change flow rate can be calculated. In the formula, i is the speed ratio. The speed ratio change rate is denoted as .

[0160] The oil flow rate at the oil pump outlet can be calculated by referring to a table to obtain the volumetric efficiency based on engine speed, main oil circuit pressure, and engine oil temperature, along with the known total displacement of the oil pump and its operating status (if it's a single pump), to determine the oil pump outlet flow rate. If it is a dual-pump operating state, the oil pump outlet flow rate Q2 = n * d * η can be calculated.

[0161] The calculation of the oil pump status determination unit 34 is as follows: If only the first oil pump 5 is working, and the flow rate of the first oil pump 5 minus a certain redundant flow rate, such as 1L / min, is already greater than the current flow rate of the oil flowing through the main oil circuit, it is determined that the first oil pump 5 is in a single-pump oil supply state; if only the first oil pump 5 is working, and the flow rate of the first oil pump 5 minus a certain redundant flow rate, such as 1L / min, is already less than the current flow rate of the oil flowing through the main oil circuit, it is determined that the oil pump status is in a dual-pump oil supply state.

[0162] The calculation method for the flow demand calculation unit 36 ​​is as follows:

[0163] When using a single pump for oil supply (initial state), calculate the actual flow rate of the lubrication and cooling system oil circuit. The specific calculation is performed using the following formula:

[0164] Q_slip = Q1 - Q3 - Q4 - Q5 - Q6 - Q7

[0165] Wherein, Q_slippery is the actual flow rate of the lubrication and cooling system oil circuit, Q1 is the oil flow rate at the outlet of the first oil pump, Q3 is the steel belt pressure change flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system.

[0166] When the actual flow rate of the lubrication and cooling system oil circuit is greater than the required flow rate of the lubrication and cooling system oil circuit, the required flow rate of the lubrication and cooling system oil circuit is the lubrication flow rate requirement.

[0167] When the second state of dual-pump oil supply is in operation, calculate the actual flow rate of the lubrication and cooling system oil circuit. Specifically, use the following formula for calculation:

[0168] Q_slip = Q2 - Q3 - Q4 - Q5 - Q6 - Q7

[0169] Wherein, Qslippery is the actual flow rate of the lubrication and cooling system oil circuit, Q2 is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump, Q3 is the steel belt pressure change flow rate, Q4 is the clutch filling oil flow rate, Q5 is the hydraulic torque converter flow rate, Q6 is the speed ratio change flow rate, and Q7 is the leakage flow rate of the hydraulic system.

[0170] When the actual flow rate of the lubrication and cooling system oil circuit is greater than the required flow rate of the lubrication and cooling system oil circuit, the required flow rate of the lubrication and cooling system oil circuit is the lubrication flow rate requirement.

[0171] In the first state of single-pump oil supply, if the available lubrication flow rate is less than the required lubrication flow rate, for example, due to a sharp change in the required flow rate such as rapid pressure changes, rapid speed ratio changes, or clutch oil filling, it is determined that the single-pump oil supply state cannot meet the system flow rate requirements, and it is necessary to increase the required flow rate to meet the system flow rate requirements. At this time, the required flow rate calculated by the flow rate calculation unit 25 is the maximum, to ensure that the state of the oil pump switching valve 8 allows the first oil pump 5 and the second oil pump 6 to simultaneously supply oil to the execution control system oil circuit 12 and the lubrication and cooling system oil circuit 13; at the same time, the flow rate requirement calculation unit 36 ​​will also request the main oil circuit pressure calculation unit 23 to additionally increase the main oil circuit pressure, for example, 3-7 bar, to further distribute the flow rate supplied to the execution control system oil circuit 12 and the lubrication and cooling system oil circuit 13, ensuring sufficient flow in the execution oil circuit.

[0172] When the system is in the first state of single-pump oil supply, if the available lubrication flow is less than the required lubrication flow, it means that the overall system flow is insufficient. The transmission controller 3 needs to request the engine controller 4 to increase the engine speed so that the flow of the first oil pump 5 and the second oil pump 6 can meet the flow requirements of the entire system's execution control system oil circuit 12 and lubrication and cooling system oil circuit 13.

[0173] Example 4:

[0174] Based on the control method of the hydraulic control system of the continuously variable transmission described above, this embodiment provides an electronic device, including a memory and a processor.

[0175] The memory stores computer programs, including program instructions. The processor executes these program instructions to cause the electronic device to perform the control method of the continuously variable transmission (CVT) hydraulic control system provided in the above embodiment. The memory may include non-permanent memory in a computer-readable medium, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. The processor is a hardware circuit with data processing capabilities, such as a CPU. Since the processor executes the method of controlling the hydraulic control system of the vehicle's CVT, this electronic device can be a vehicle controller.

[0176] Example 5:

[0177] Based on the control method of the hydraulic control system of the continuously variable transmission (CVT) described above, this embodiment provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which includes program instructions. The program instructions are executed by an electronic device to cause the electronic device to perform the control method of the hydraulic control system of the CVT as described in any of the above embodiments.

[0178] Computer-readable media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data.

[0179] Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information that can be accessed by a computing device.

[0180] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A hydraulic control system for a continuously variable transmission (CVT), characterized in that, The hydraulic control system is connected to the hydraulic system and the transmission controller of the continuously variable transmission (CVT), and the transmission controller is connected to the engine controller of the vehicle. in The hydraulic system includes: An oil pump control valve assembly, connected to a first oil pump and a second oil pump, controls the operating states of the first oil pump and the second oil pump; and The main oil circuit has its input end connected to the hydraulic oil chamber and its output end connected to the oil circuit of the continuously variable transmission's (CVT) execution control system and lubrication and cooling system, respectively. Furthermore, the oil outlets of the first and second oil pumps are respectively connected to the main oil circuit. The main oil line is equipped with a main oil line control valve assembly, which controls the flow rate and pressure of the oil flowing through the main oil line; and The hydraulic control system calculates the actual flow rate of the oil flowing into the lubrication and cooling system based on the current flow rate of the oil flowing through the main oil circuit, the flow rate of the oil flowing into the execution control system oil circuit, and the leakage flow rate of the hydraulic system. Based on the actual flow rate of the oil flowing into the lubrication and cooling system oil circuit, the preset redundant flow rate, and the required flow rate of the lubrication and cooling system oil circuit, the control system controls the oil pump control valve assembly and the main oil circuit control valve assembly, and sends speed request information to the engine controller to control the working status of the first oil pump and the second oil pump, the flow rate and pressure of the oil flowing through the main oil circuit, and the engine speed. The hydraulic control system includes: The valve control unit includes an actuator valve control component, a main oil circuit valve control component, and an oil pump valve control component; wherein... The actuator valve control assembly is connected to each control valve in the oil circuit of the actuator control system, the main oil circuit valve control component is connected to the main oil circuit control valve assembly, and the oil pump valve control component is connected to the oil pump control valve assembly. An execution control system status parameter acquisition unit is configured to be connected to both the transmission controller and the execution control system of the continuously variable transmission (CVT). This unit acquires execution control system status parameters from the execution control systems and sends these parameters to the transmission controller. A control current generating unit includes an actuator current generating component, a main oil circuit current generating component, and an oil pump current generating component, all of which are communicatively connected to each other. The actuator current generating component is communicatively connected to the transmission controller and receives the execution control system status parameters from the transmission controller. The actuator current generating component is connected to the actuator valve control component. It calculates the actuator target control pressure according to the pre-input pressure control requirements, and obtains the actuator control current according to the actuator target control pressure using a preset first current generating rule. The actuator control current is then output to the actuator valve control component to control the state of each control valve in the actuator control system oil circuit. The main oil circuit current generating component is connected to the main oil circuit valve control component. It calculates the main oil circuit valve target control pressure based on the actuator target control pressure from the actuator current generating component and the pressure demand information from the oil pump current generating component. It obtains the main oil circuit valve control current according to the first current generation rule based on the main oil circuit valve target control pressure, and outputs the main oil circuit valve control current to the main oil circuit valve control component so as to control the state of the main oil circuit control valve component. The oil pump current generating component is connected to the oil pump valve control component. Based on the pre-input flow control requirements, the actuator target control pressure from the actuator current generating component, the execution control system status parameters, and the main oil circuit valve target control pressure from the main oil circuit current generating component, the oil pump valve target control flow is calculated. The oil pump valve control current is obtained according to the oil pump valve target control flow using a preset second current generation rule. The oil pump valve control current is then output to the oil pump valve control component to control the state of the oil pump control valve assembly.

2. The hydraulic control system of the continuously variable transmission as described in claim 1, characterized in that, The oil pump control valve assembly includes: An oil pump switching valve is connected to a first oil pump and a second oil pump. A switching control valve is connected to the oil pump switching valve via a first control oil circuit. The switching control valve controls the flow rate and pressure of the oil flowing through the first control oil circuit to control the working state of the first oil pump and the second oil pump. The main oil circuit control valve assembly includes: A pressure regulating valve that regulates the flow rate and pressure of the oil flowing through the main oil circuit; A regulating control valve is connected to the pressure regulating valve via a second control oil circuit. The regulating control valve controls the flow rate and pressure of the oil flowing through the second control oil circuit to control the pressure regulating valve.

3. The hydraulic control system of the continuously variable transmission as described in claim 2, characterized in that, The oil pump switching valve, the switching control valve, the pressure regulating valve, and the regulating control valve are all solenoid valves.

4. The hydraulic control system of the continuously variable transmission as described in any one of claims 1-3, characterized in that, The oil circuit of the execution control system is connected to the execution control system of the continuously variable transmission (CVT), and the execution control system of the CVT includes a driving steel belt, a driven steel belt, a clutch, and a hydraulic torque converter. The hydraulic circuit of the actuator control system includes a driving steel belt control circuit, a driven steel belt control circuit, a clutch control circuit, and a hydraulic torque converter control circuit; in The input end of the active steel belt control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the active steel belt. The active steel belt control oil circuit is also equipped with an active steel belt control valve. The input end of the driven steel belt control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the driven steel belt. The driven steel belt control oil circuit is also equipped with a driven steel belt control valve. The input end of the clutch control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the clutch. The clutch control oil circuit is also equipped with a clutch control valve. The input end of the hydraulic torque converter control oil circuit is connected to the output end of the main oil circuit, and the output end is connected to the hydraulic torque converter. The hydraulic torque converter control oil circuit is also equipped with a hydraulic torque converter control valve.

5. The hydraulic control system of the continuously variable transmission as described in claim 4, characterized in that, It also includes a pressure control requirement acquisition unit, which is connected to the gearbox controller and the continuously variable transmission (CVT) execution control system respectively, acquires the pressure control requirements from the execution control system, and sends the pressure control requirements to the gearbox controller; The gearbox controller is also connected to the actuator current generating component, and sends the pressure control request to the actuator current generating component; The actuator valve control assembly includes: a driving steel belt control component, a driven steel belt control component, a clutch control component, and a hydraulic torque converter control component; and The actuator current generating assembly includes: a steel belt current generating component, a clutch current generating component, and a hydraulic torque converter current generating component; and The pressure control requirements include: steel belt pressure control requirements, clutch pressure control requirements, and hydraulic torque converter pressure control requirements. The actuator target control pressure includes the active steel belt control pressure, the driven steel belt control pressure, the clutch control pressure, and the hydraulic torque converter control pressure; The actuator control current includes the active steel belt control current, the driven steel belt control current, the clutch control current, and the hydraulic torque converter control current; wherein The steel belt current generating component calculates the active steel belt control pressure and the driven steel belt control pressure according to the steel belt pressure control requirements from the gearbox controller, and outputs the active steel belt control current and the driven steel belt control current to the active steel belt control component and the driven steel belt control component respectively according to the first current generation rule, so as to control the active steel belt control component and the driven steel belt control component respectively according to the active steel belt control current and the driven steel belt control current; The clutch current generating component calculates the clutch control pressure according to the clutch pressure control requirements from the transmission controller, and outputs the clutch control current to the clutch control component according to the first current generating rule based on the clutch control pressure, so as to control the clutch control component according to the clutch control current. The torque converter current generating component calculates the torque converter control pressure according to the torque converter pressure control requirements from the transmission controller, and outputs the torque converter control current to the torque converter control component according to the first current generating rule based on the torque converter control pressure, so as to control the torque converter control component according to the torque converter control current.

6. The hydraulic control system of the continuously variable transmission as described in claim 5, characterized in that, The steel belt pressure control requirements include the vehicle's pedal opening, the speed of the continuously variable transmission's (CVT) drive pulley, the speed of the CVT driven pulley, and the engine's torque. The clutch pressure control requirements include the vehicle's pedal opening, the engine speed, the continuously variable transmission's turbine speed, and the vehicle's current gear. The hydraulic torque converter pressure control requirements include the vehicle's pedal opening, the engine speed, the continuously variable transmission's turbine speed, and the current vehicle speed; and The preset rule for generating the first current is: the pressure-current curve of the solenoid valve obtained through calibration.

7. The hydraulic control system of the continuously variable transmission as described in claim 6, characterized in that, The main oil circuit current generating component includes a main oil circuit oil pressure calculation component and a main oil circuit current generating component; in The signal input terminal of the main oil circuit pressure calculation component is connected to the oil pump current generating component and the actuator current generating component, respectively; the signal output terminal is connected to the signal input terminal of the main oil circuit current generating component; and the signal output terminal of the main oil circuit current generating component is connected to the main oil circuit valve control component. The main oil circuit oil pressure calculation component calculates the target control pressure of the main oil circuit valve based on the actuator target control pressure from the actuator current generating component, the pressure demand information from the oil pump current generating component, and the redundant flow. The main oil circuit current generating component obtains the main oil circuit valve control current according to the target control pressure of the main oil circuit valve from the main oil circuit oil pressure calculation component and the first current generation rule, and outputs the main oil circuit valve control current to the main oil circuit valve control component.

8. The hydraulic control system of the continuously variable transmission as described in claim 7, characterized in that, The preset range of the redundant flow rate is 0.8L / min to 1.2L / min.

9. The hydraulic control system of the continuously variable transmission as described in claim 8, characterized in that, The transmission controller is connected to the vehicle's overall controller to obtain the flow control requirements from the overall controller; The oil pump current generating component includes a flow calculation component and an oil pump current generating component; in The signal input terminal of the flow calculation component is connected to the main oil circuit pressure calculation component, the actuator current generating component, and the gearbox controller, respectively; its output terminal is connected to the signal input terminal of the oil pump current generating component; and the signal output terminal of the oil pump current generating component is connected to the oil pump valve control component. The flow calculation component calculates the target control flow of the oil pump valve based on the flow control requirements from the gearbox controller, the actuator target control pressure from the actuator current generating component, the state parameters of the execution control system, and the target control pressure of the main oil circuit valve from the main oil circuit pressure calculation component. The oil pump current generating component obtains the oil pump valve control current according to the oil pump valve target control flow from the flow calculation component and the second current generation rule, and outputs the oil pump valve control current to the oil pump valve control component.

10. The hydraulic control system of the continuously variable transmission as described in claim 9, characterized in that, The flow control requirements include the engine speed, the engine oil temperature, the current vehicle speed, and the vehicle's current gear. The state parameters of the execution control system include: the speed ratio of the driving steel belt and the driven steel belt, the rate of change of the speed ratio of the driving steel belt and the driven steel belt, the state of the clutch, and the state of the hydraulic torque converter; The preset rule for generating the second current is: the flow-current curve of the solenoid valve obtained through calibration.

11. The hydraulic control system of the continuously variable transmission as described in claim 10, characterized in that, It also includes an actuator flow calculation parameter acquisition unit, which is connected to the gearbox controller and the continuously variable transmission's execution control system respectively, acquires actuator flow calculation parameters from the execution control system, and sends the actuator flow calculation parameters to the gearbox controller; The transmission controller is connected to the vehicle controller to obtain vehicle status parameters from the vehicle controller. The flow calculation component includes: A system flow calculation unit, the signal input terminal of which is connected to the transmission controller, calculates the system flow based on the vehicle status parameters from the transmission controller and the actuator flow calculation parameters; An oil pump status determination unit, wherein the signal input terminal of the oil pump status determination unit is connected to the first oil pump and obtains the oil flow rate of the first oil pump; An oil pump flow calculation unit is provided, the input of which is connected to the output of the oil pump status determination unit, the output of the system flow calculation unit, and the output of the main oil circuit pressure calculation component. The unit calculates the flow rate of the oil currently flowing through the main oil circuit based on the oil flow rate of the first oil pump from the oil pump status determination unit, the system flow rate from the system flow calculation unit, and the redundant flow rate from the main oil circuit pressure calculation component. A flow demand calculation unit is provided, with its signal input terminal connected to the signal output terminal of the system flow calculation unit and the signal output terminal of the oil pump flow calculation unit. Based on the system flow rate from the system flow calculation unit and the current flow rate of oil flowing through the main oil circuit from the oil pump flow calculation unit, the unit calculates the actual flow rate into the lubrication and cooling system oil circuit. Based on the actual flow rate into the lubrication and cooling system oil circuit and the required flow rate of the lubrication and cooling system oil circuit, it generates boost information, flow demand information, and speed request information. Based on the boost information, it controls the pressure of the oil flowing through the main oil circuit; based on the flow demand information, it controls the flow rate of the oil flowing through the main oil circuit; and based on the speed request information, it controls the engine speed.

12. The hydraulic control system of the continuously variable transmission as described in claim 11, characterized in that, The vehicle status parameters include engine oil temperature, current gear, and current vehicle speed. The actuator flow calculation parameters include: steel belt pressure converter flow parameters, clutch flow parameters, hydraulic torque converter flow parameters, and steel belt speed ratio flow parameters; The system flow rate includes: the flow rate of oil flowing into the actuator control system oil circuit, the actual flow rate flowing into the lubrication and cooling system oil circuit, and the leakage flow rate of the hydraulic system; wherein, the flow rate of oil flowing into the actuator control system oil circuit includes the steel belt pressure change flow rate, clutch filling flow rate, torque converter flow rate, and speed ratio change flow rate; and The system traffic calculation unit includes: A steel strip voltage transformer current calculation unit is connected to the steel strip current generating component and calculates the steel strip voltage transformer current based on the steel strip voltage transformer current parameters from the steel strip current generating component. A clutch flow calculation unit is connected to the clutch current generating component and calculates the clutch oil flow rate based on the clutch flow parameters from the clutch current generating component. A hydraulic torque converter flow calculation unit is connected to the hydraulic torque converter current generating component and calculates the hydraulic torque converter flow rate based on the hydraulic torque converter flow parameters from the hydraulic torque converter current generating component. A leakage flow calculation unit is connected to the steel strip current generating component, the clutch current generating component, and the hydraulic torque converter current generating component, respectively, and calculates the leakage flow of the hydraulic system based on the pre-input oil temperature of the engine and the actuator flow calculation parameters. The lubrication flow calculation unit obtains the actual flow rate of oil flowing into the lubrication and cooling system by looking up a table based on the pre-input oil temperature of the engine, the current gear of the vehicle, and the current vehicle speed. A steel belt speed ratio flow rate calculation unit is connected to the steel belt current generating component and calculates the speed ratio change flow rate based on the steel belt speed ratio flow rate parameters from the steel belt current generating component.

13. The hydraulic control system of the continuously variable transmission as described in claim 12, characterized in that, The steel belt pressure-variable flow parameters include the active steel belt control pressure and the driven steel belt control pressure; The clutch flow parameters include the clutch oil passage volume and the target filling time. The flow parameters of the hydraulic torque converter include the state of the hydraulic torque converter, the control pressure of the hydraulic torque converter, and the lock-up area between the hydraulic torque converter and the clutch. The steel belt speed ratio flow parameters include the dimensions of the active steel belt, the dimensions of the driven steel belt, the piston actuation area of ​​the active steel belt, and the piston actuation area of ​​the driven steel belt.

14. A control method for the hydraulic control system of a continuously variable transmission (CVT) as described in claim 13, characterized in that, Includes the following steps: S1: The hydraulic system acquires the vehicle status parameters and the actuator flow calculation parameters, and determines the current flow rate of the oil flowing through the main oil circuit, the flow rate of the oil flowing into the execution control system oil circuit, and the leakage flow rate of the hydraulic system based on the vehicle status parameters and the actuator flow calculation parameters. S2: The hydraulic control system calculates the actual flow rate into the lubrication and cooling system oil circuit based on the current flow rate of oil flowing through the main oil circuit from the hydraulic system, the flow rate of oil flowing through the first oil pump, and the redundant flow rate, and determines the working state of the first oil pump and the second oil pump; wherein, the working state includes a first state in which the first oil pump is working, and a second state in which both the first oil pump and the second oil pump are working. S3: Determine whether the actual flow rate into the lubrication and cooling system oil circuit in the first state and the second state can meet the required flow rate of the lubrication and cooling system oil circuit calculated by the flow calculation component; If the requirement is met, the oil pump valve control current and the main oil circuit valve control current are output according to the required flow rate. If the conditions are not met, proceed with the following steps: If the first oil pump and the second oil pump are currently in the first state, then control the first oil pump and the second oil pump to work in the second state, and output control commands to the main oil circuit pressure calculation unit to increase the flow rate and pressure of the oil flowing through the main oil circuit; If the first oil pump and the second oil pump are currently in the second state, a speed request message is sent to the engine controller to increase the engine speed.

15. The control method for the hydraulic control system of the continuously variable transmission as described in claim 14, characterized in that, In step S2, if the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is greater than the current flow rate of the oil flowing through the main oil circuit, then the working state is the first state. If the difference between the flow rate of the oil flowing through the first oil pump and the redundant flow rate is less than the current flow rate of the oil flowing through the main oil circuit, then the working state is the second state. and In the first state, the current flow rate of the oil flowing through the main oil circuit is the oil flow rate at the outlet of the first oil pump; In the second state, the current flow rate of the oil flowing through the main oil circuit is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump.

16. The control method of the hydraulic control system of the continuously variable transmission as described in claim 15, characterized in that, The vehicle status parameters also include the total displacement of the first oil pump; and In the first state, the oil flow rate at the outlet of the first oil pump is calculated according to the following formula: in Let be the oil flow rate at the outlet of the first oil pump. The engine speed is [value missing]. This represents the total displacement of the first oil pump. The volumetric efficiency of the first oil pump at different oil temperatures is obtained by looking up a table based on the engine speed, main oil circuit pressure, and engine oil temperature. In the second state, the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump is calculated according to the following formula: in, It is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump. The engine speed is [value missing]. This represents the total displacement of the first oil pump. The volumetric efficiency of the first oil pump at different oil temperatures is obtained by referring to a table based on the engine speed, main oil circuit pressure, and engine oil temperature.

17. The control method for the hydraulic control system of the continuously variable transmission as described in claim 16, characterized in that, In the first state, the actual flow rate of the lubrication and cooling system oil circuit is calculated according to the following formula: in, This refers to the actual flow rate of the oil circuit in the lubrication and cooling system. Let be the oil flow rate at the outlet of the first oil pump. The current is the pressure change of the steel strip. The oil flow rate for the clutch. The flow rate of the hydraulic torque converter, The speed ratio variation flow rate, The leakage flow rate of the hydraulic system; and In the second state, the actual flow rate of the lubrication and cooling system oil circuit is calculated according to the following formula: in, This refers to the actual flow rate of the oil circuit in the lubrication and cooling system. It is the sum of the oil flow rate at the outlet of the first oil pump and the oil flow rate at the outlet of the second oil pump. The current is the pressure change of the steel strip. The oil flow rate for the clutch. The flow rate of the hydraulic torque converter, The speed ratio variation flow rate, The leakage flow rate of the hydraulic system; and The steel strip pressure-variable flow rate is obtained by looking up a table based on the change rate of the active steel strip control pressure and the driven steel strip control pressure; The clutch oil flow rate is calculated according to the following formula: in, The oil flow rate for the clutch. Let V be the volume of the oil passage in the clutch. The target oil filling time; The flow rate of the hydraulic torque converter is calculated according to the following formula: in, The flow rate of the hydraulic torque converter, The change in the volume of the hydraulic torque converter in each cycle is obtained by looking up a table based on the state of the hydraulic torque converter, the control pressure of the hydraulic torque converter, and the lock-up area of ​​the hydraulic torque converter and the clutch; and The flow rate with varying speed ratio is calculated using the following formula: in, The speed ratio variation flow rate, The speed ratio between the driving steel belt and the driven steel belt is obtained by looking up a table based on the dimensions of the driving steel belt, the dimensions of the driven steel belt, the piston actuation area of ​​the driving steel belt, and the piston actuation area of ​​the driven steel belt.

18. An electronic device, characterized in that, include: A memory for storing computer programs, the computer programs including program instructions; A processor for executing the program instructions to cause the electronic device to perform a control method for the hydraulic control system of a continuously variable transmission according to any one of claims 14-17.

19. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions, which are executed by an electronic device to cause the electronic device to perform the control method of the hydraulic control system of the continuously variable transmission as described in any one of claims 14-17.

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