Hydraulic control system for hybrid power gearbox

Abstract

The invention discloses a hydraulic control system for a hybrid power gearbox, which relates to the field of gearbox hydraulic control and comprises an oil supply subsystem, a main oil pressure adjusting subsystem, a gear shifting control subsystem, a lubrication cooling subsystem and a clutch control subsystem. According to the hydraulic control system for the hybrid power gearbox, the suction filter body, the first pump body, the second pump body, the high-pressure filter body and the temperature sensor body are arranged, oil liquid can be conveniently filtered many times, the structure is compact, and the temperature is monitored; the hydraulic control system is provided with a first filter screen, a second filter screen, an energy accumulator body and a pressure sensor body, the main oil pressure of the system can be accurately adjusted, the pressure of the system can be stably controlled, and a gear shifting piston, a third throttling hole and a fourth throttling hole are arranged, so that the gear shifting action can be quickly executed; impurity clamping stagnation prevention, pressure impact buffering, dynamic feedback control and closed-loop control of the system can be achieved conveniently.

Description

Technical Field

[0001] The present invention relates to the field of transmission hydraulic control technology, and particularly to a hydraulic control system for a hybrid transmission. Background Art

[0002] Transmission hydraulic control refers to controlling the shifting operation and transmission ratio adjustment of a transmission through a hydraulic system to ensure that the vehicle can operate smoothly and efficiently under different working conditions. Automotive transmissions are also widely used in the hydraulic control system of hybrid transmissions. In the existing hydraulic control system of hybrid transmissions, since the hydraulic system is significantly affected by the fluctuation of the main oil circuit pressure, the pilot control oil pressure in the shift control subsystem is unstable, and the shift spool controlled by the solenoid valve fluctuates accordingly, affecting the smoothness of power output, and thus the conversion effect of the hybrid power is not good.

[0003] To address existing deficiencies, reference can be made to a hybrid vehicle and its transmission hydraulic control system disclosed in the prior art (a Chinese patent with application number 201410796475.6 and filing date December 18, 2014), which includes a hydraulic control system. The latter includes a dual clutch, a first dual clutch control oil circuit for controlling the on / off of the first clutch of the dual clutch, and a second dual clutch control oil circuit for controlling the on / off of the second clutch of the dual clutch. It also includes a single clutch and a single clutch control oil circuit for controlling the on / off of the single clutch. One side of the single clutch is connected to the engine, and the other side is connected to the transmission system. The single clutch control oil circuit includes a single pressure control valve and a single switch valve. Both the single pressure control valve and the single switch valve are in the conducting position, and the single clutch is connected to the oil source. When the single pressure control valve is in the cut-off position, the single clutch is disconnected from the oil source. When the single switch valve is in the cut-off position, the single clutch is connected to the oil return tank. Only by making simple structural improvements on the basis of the original dual clutch automatic transmission can the conversion and output of hybrid power be achieved, thereby reducing the design and manufacturing difficulty. And reference can be made to the lubrication system of the transmission disclosed in the prior art (application number: 201320588789.8, filing date September 24, 2013), which includes a filter, a hydraulic pump, and a reversing valve connected in series in sequence. The filter is connected to the lubricating oil sump. There is a spray pipe, one end of which is connected to the reversing valve. There are multiple spray holes on the spray pipe. There are two passages connected between the spray pipe and the reversing valve. A cooling module is provided on one of the passages. There is a bearing housing, which is connected to the other end of the spray pipe through a low-pressure oil passage. The spray pipe and the bearing housing are respectively connected to the lubricating oil sump, and a control module is connected to the reversing valve. The lubrication system of the transmission uses the forced lubrication method to lubricate the gears and bearings of the dual clutch transmission with complex working conditions, not only greatly improving the lubrication efficiency, but also improving the anti-wear and anti-sintering performance between gears and between shafts and bearings. At the same time, by regulating the lubricating oil flow and oil circuit, the working efficiency of the transmission is effectively improved.

[0004] Although the prior art achieves the conversion and output of hybrid power and the lubrication of the transmission, the lubrication system uses a series layout of a filter, a hydraulic pump, and a reversing valve, which requires an additional cooling module and an independent oil circuit, resulting in a large system volume. And it relies on the reversing valve to achieve oil circuit switching, lacking an accurate regulation mechanism for the main oil pressure of the system. Also, no pressure sensor or closed-loop control system is provided, so it is impossible to monitor the pressure in the clutch piston chamber in real time and dynamically adjust the opening of the solenoid valve.

[0005] Therefore, we propose a hydraulic control system for a hybrid transmission to facilitate solving the problems raised above. Summary of the Invention

[0006] The object of the present invention is to provide a hydraulic control system for a hybrid transmission, so as to solve the problems raised in the above background technology. When the transmission hydraulic control system on the current market is in use, since the lubrication system adopts a series layout of filters, hydraulic pumps and reversing valves, an additional cooling module and an independent oil circuit need to be set up, resulting in a large system volume. And it relies on the reversing valve to realize oil circuit switching, lacking an accurate regulation mechanism for the main oil pressure of the system, and no pressure sensor or closed-loop control system is set up, so that the pressure of the clutch piston chamber cannot be monitored in real time and the opening of the solenoid valve cannot be dynamically adjusted.

[0007] To achieve the above object, the present invention provides the following technical solution: A hydraulic control system for a hybrid transmission includes an oil supply subsystem, a main oil pressure regulation subsystem, a shift control subsystem, a lubrication and cooling subsystem, and a clutch control subsystem; the output end of the oil supply subsystem is respectively connected to the main oil pressure regulation subsystem and the lubrication and cooling subsystem through a main oil circuit, providing hydraulic oil for the main oil pressure regulation and lubrication and cooling processes. The output end of the main oil pressure regulation subsystem is respectively connected to the shift control subsystem and the clutch control subsystem through a main oil circuit, providing hydraulic oil that meets the pressure requirements for the shift control and clutch control processes; the oil supply subsystem includes an oil tank for storing hydraulic oil. A temperature sensor body is arranged at the bottom of the oil tank. An oil suction filter body is arranged inside the oil tank. The output end of the oil suction filter body is respectively connected to the input ends of a first pump body and a second pump body through an oil circuit. The top of the first pump body is connected with a high-pressure filter body for finely filtering high-pressure oil.

[0008] Preferably, a first safety valve body is arranged on the main oil circuit connecting the output end of the oil supply subsystem to the main oil pressure regulation subsystem and the shift control subsystem.

[0009] Preferably, the main oil pressure regulation subsystem includes a first filter screen installed on the oil circuit entering the main oil pressure regulation subsystem. A first throttle hole is opened at the top of the oil circuit of the first filter screen. A first accumulator body is arranged on the right side of the oil circuit of the first throttle hole; the main oil pressure regulation subsystem further includes a second throttle hole and a main spool valve, and the main spool valve is located at the pilot end on the left side of the second throttle hole.

[0010] Preferably, the shift control subsystem receives hydraulic oil from the main oil pressure regulating subsystem. The shift control subsystem includes a second filter screen, which is installed on the oil path entering the shift control subsystem and is used to filter the oil entering the shift control subsystem. A third throttle hole is provided at the top of the second filter screen oil path, and the third throttle hole is used to control the oil flow rate entering the subsequent shift control components. A shift piston is arranged on the right side of the third throttle hole oil path, and the shift piston realizes the shift action under the action of hydraulic oil. A fourth throttle hole is provided on the right side of the shift piston oil path, and the fourth throttle hole is used to control the flow rate when the shift piston returns oil. A third filter screen is arranged at the bottom of the fourth throttle hole oil path, and the third filter screen is used to filter the return oil.

[0011] Preferably, the shift control subsystem is connected to the clutch control subsystem through an oil path to realize the coordinated operation of shifting and clutch control. The clutch control subsystem includes a fourth filter screen, which is installed on the oil path entering the clutch control subsystem and is used to filter the oil entering the clutch control subsystem. The top of the fourth filter screen oil path is respectively connected to a second accumulator body and a pressure sensor body. A clutch body is arranged at the top between the second accumulator body and the pressure sensor body, and the oil pressure and flow rate entering the clutch body are controlled.

[0012] Preferably, the oil supply subsystem is connected to the lubrication and cooling subsystem through an oil path and receives low-pressure oil from the second pump body. The lubrication and cooling subsystem includes a second safety valve body and an oil cooler body.

[0013] Preferably, the first pump body is set as a high-pressure pump for providing high-pressure oil, and the second pump body is set as a low-pressure pump for providing low-pressure oil. As the provider of high-pressure oil, the first pump body pressurizes the oil filtered by the suction filter body into high-pressure oil to provide power support for the main oil pressure regulating subsystem and the shift control subsystem that require high-pressure oil.

[0014] Preferably, the second safety valve body is used to open when the oil pressure of the lubrication and cooling subsystem exceeds the set value, and drain the excess oil back to the fuel tank. The second pump body is responsible for providing low-pressure oil, pressurizing the oil and transporting it to the lubrication and cooling subsystem to meet the lubrication and cooling requirements of each component of the gearbox and realize the fast and accurate switching of gears.

[0015] Preferably, the oil cooler body is used to cool the oil entering the lubrication and cooling subsystem.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The hydraulic control system for the hybrid transmission, by setting up a suction filter body, a first pump body, a second pump body, a high-pressure filter body and a temperature sensor body, facilitates multiple filtrations of the oil fluid, has a compact structure and monitors the temperature. Moreover, by setting up a main spool valve, a first filter screen, a first throttle hole, and a second throttle hole, it is convenient to accurately regulate the size of the main oil pressure of the system and stabilize the system pressure. And by setting up a shift piston, a third throttle hole, and a fourth throttle hole, it is convenient to quickly execute the shift action. At the same time, by setting up a fourth filter screen, a second accumulator body and a pressure sensor body, it is convenient to enable the system to have functions such as preventing impurity jamming, buffering pressure shocks, dynamic feedback control and closed-loop control. The specific content is as follows; 1. A suction filter body, a first pump body, a second pump body, a high-pressure filter body and a temperature sensor body are provided. The suction filter body effectively intercepts and preliminarily filters the oil fluid to prevent impurities from entering each component and causing wear and jamming. The integrated design of the first pump body and the second pump body makes the system structure more compact, reduces space occupation, and also meets the lubrication and cooling requirements of each component of the transmission. The high-pressure filter body finely filters the high-pressure oil fluid again to remove tiny impurities and improve the cleanliness of the oil fluid. The temperature sensor body monitors the temperature of the hydraulic system in real time.

[0017] 2. A main spool valve, a first filter screen, a first throttle hole, and a second throttle hole are provided. Through the operation of the main spool valve, it is convenient to accurately regulate the size of the main oil pressure of the system. The first filter screen filters the hydraulic oil again, which can effectively intercept possible impurities in the oil fluid and prevent the solenoid valve VBS from jamming due to impurities in the oil fluid, further improving the accurate regulation of the main oil pressure. The first throttle hole and the second throttle hole play a buffering role in the flow of the oil fluid, thereby delaying the rapid change of the system state, reducing oscillations, and making the pressure control more gentle and stable, facilitating the stable control of the system pressure.

[0018] 3. A shift piston, a third throttle hole, and a fourth throttle hole are provided. By precisely controlling the solenoid valve to change the on-off state of the oil circuit, the hydraulic oil is guided to act stably on the shift piston, and then drives the shift fork to complete an accurate shift from the current gear to the target gear, meeting the gear requirements under different working conditions of the vehicle, ensuring the power transmission efficiency. The third throttle hole and the fourth throttle hole respectively play a flow control role during the entry and return of the hydraulic oil.

[0019] 4. A fourth filter screen, a second accumulator body, and a pressure sensor body are provided. The fourth filter screen intercepts impurities, thus preventing the impurities from jamming the control valve. An accumulator body is provided in the oil circuit of the clutch body cavity, which can effectively absorb the fluctuations in the oil circuit and avoid hydraulic shock caused by the fluctuations in the oil circuit. The second accumulator body can absorb oil vibration and hydraulic shock caused by the fluctuations in the main oil circuit, achieving smooth curve linear control. A pressure sensor body is provided on the control loop, providing more accurate data support for software closed-loop control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a front view structural schematic diagram of the present invention; Figure 2 is a specific front view structural schematic diagram of the present invention; Figure 3 is a partial structural schematic diagram of the oil supply subsystem of the present invention; Figure 4 is a partial structural schematic diagram of the main oil pressure regulation subsystem of the present invention; Figure 5 is a partial structural schematic diagram of the shift control subsystem of the present invention; Figure 6 is a partial structural schematic diagram of the lubrication and cooling subsystem of the present invention; Figure 7 is a partial structural schematic diagram of the clutch control subsystem of the present invention.

[0021] In the figure: 1. Oil supply subsystem; 101. Fuel tank; 102. Temperature sensor body; 103. Suction filter body; 104. First pump body; 105. Second pump body; 106. High-pressure filter body; 107. First safety valve body; 2. Main oil pressure regulation subsystem; 201. First filter screen; 202. First throttle orifice; 203. First accumulator body; 204. Second throttle orifice; 205. Main spool valve; 3. Shift control subsystem; 301. Second filter screen; 302. Third throttle orifice; 303. Shift piston; 304. Fourth throttle orifice; 305. Third filter screen; 4. Lubrication and cooling subsystem; 401. Second safety valve body; 402. Oil cooler body; 5. Clutch control subsystem; 501. Clutch body; 502. Second accumulator body; 503. Pressure sensor body; 504. Fourth filter screen. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figures 1-7 , the present invention provides the following technical solutions: Embodiment 1: In order to solve the problem that when the transmission hydraulic control system on the market is in use, since the lubrication system adopts a series filter, hydraulic pump and directional valve layout, an additional cooling module and independent oil circuit need to be set, resulting in a large system volume. The following technical content is disclosed in a hydraulic control system for a hybrid transmission in this embodiment, which can be referred to in the attached Figure 1 - attached Figure 3 and attached Figure 6 , including an oil supply subsystem 1, a main oil pressure regulation subsystem 2, a shift control subsystem 3, a lubrication and cooling subsystem 4, and a clutch control subsystem 5; the output end of the oil supply subsystem 1 is respectively connected to the main oil pressure regulation subsystem 2 and the lubrication and cooling subsystem 4 through the main oil circuit to provide hydraulic oil for the main oil pressure regulation and lubrication and cooling processes. The output end of the main oil pressure regulation subsystem 2 is respectively connected to the shift control subsystem 3 and the clutch control subsystem 5 through the main oil circuit to provide hydraulic oil that meets the pressure requirements for the shift control and clutch control processes; the oil supply subsystem 1 includes an oil tank 101 for storing hydraulic oil. A temperature sensor body 102 is arranged at the bottom of the oil tank 101. A suction filter body 103 is arranged inside the oil tank 101. The output end of the suction filter body 103 is respectively connected to the input ends of a first pump body 104 and a second pump body 105 through the oil circuit. A high-pressure filter body 106 is connected to the top of the first pump body 104 for finely filtering high-pressure oil; a first safety valve body 107 is arranged on the main oil circuit connecting the output end of the oil supply subsystem 1 to the main oil pressure regulation subsystem 2 and the shift control subsystem 3; the oil supply subsystem 1 is connected to the lubrication and cooling subsystem 4 through the oil circuit to receive low-pressure oil from the second pump body 105. The lubrication and cooling subsystem 4 includes a second safety valve body 401 and an oil cooler body 402; the first pump body 104 is set as a high-pressure pump for providing high-pressure oil, and the second pump body 105 is set as a low-pressure pump for providing low-pressure oil.

[0024] The oil tank 101 is used as the oil reservoir of the hydraulic system to provide the oil source for the entire system. The suction filter body 103 is installed on the top of the oil tank 101 and is the first line of defense for the hydraulic oil to enter the system. When the system is started and the hydraulic pump starts to work, the hydraulic oil in the oil tank 101 is extracted under the action of negative pressure, and the oil first enters the suction filter body 103, where the impurities and particles are effectively intercepted, thereby providing the subsequent double pump (the first pump body 104 and the second pump body 105), the clutch control subsystem 5 and the lubrication and cooling subsystem 4 with a higher degree of cleanliness, preventing impurities from entering the first pump body 104. 4 and the second pump body 105, causing the internal parts of the pump to wear more severely, preventing impurities from entering the clutch control subsystem 5, causing the valve core to be stuck, and preventing impurities from entering the lubrication and cooling subsystem 4, causing parts to wear, reducing the lubrication and cooling effect, and affecting the performance and life of the entire gearbox. Since the first pump body 104 and the second pump body 105 drive the driving gear to work through the same drive shaft, this integrated design makes the system structure more compact and reduces space occupation. The first pump body 104 is used as a provider of high-pressure oil, so that the first pump body 104 can filter the oil filtered by the suction filter body 103. The high-pressure oil is pressurized into high-pressure oil to provide power support for the main oil pressure regulating subsystem 2 and the shift control subsystem 3 that require high-pressure oil. The second pump body 105 is responsible for providing low-pressure oil, and the oil is pressurized and transported to the lubrication and cooling subsystem 4 to meet the lubrication and cooling needs of various parts of the gearbox, so as to achieve fast and accurate shifting of gears. The high-pressure filter body 106 is connected to the top of the first pump body 104. When the high-pressure oil output by the first pump body 104 enters the high-pressure filter body 106, the tiny impurities in the oil (such as metal powder, rubber particles, oil sludge, etc.) will be intercepted by the filter element, which will affect the high pressure. Fine filtering the oil again can not only further remove these tiny impurities and improve the cleanliness of the oil to a higher level, greatly reduce the probability of the solenoid valve and the main valve core 205 getting stuck, ensure the accuracy and reliability of the shift control and clutch control process, but also ensure that the flow resistance of the oil during the filtration process is relatively small and will not cause excessive impact on the system pressure. Since the temperature sensor body 102 is arranged on the right side of the oil tank 101, it is used to monitor the temperature of the entire hydraulic system in real time, and provide a key temperature reference coefficient for the control of the first pump body 104, the second pump body 105 and the clutch proportional valve.

[0025] Embodiment 2: A hybrid transmission hydraulic control system in this embodiment discloses the following technical contents, which is convenient for accurately adjusting the main oil pressure of the system and stabilizing the control system pressure. Figure 1 -Attached Figure 4, the main oil pressure regulating subsystem 2 includes a first filter screen 201. The first filter screen 201 is installed on the oil path entering the main oil pressure regulating subsystem 2. A first throttle hole 202 is provided at the top of the oil path of the first filter screen 201. A first accumulator body 203 is arranged on the right side of the oil path of the first throttle hole 202. The main oil pressure regulating subsystem 2 further includes a second throttle hole 204 and a main spool 205. The main spool 205 is located at the pilot end on the left side of the second throttle hole 204. The second safety valve body 401 is used to open when the oil pressure of the lubrication and cooling subsystem 4 exceeds the set value, and drain the excess oil back to the oil tank 101. The oil cooler body 402 is used to cool the oil entering the lubrication and cooling subsystem 4.

[0026] When the first pump body 104 starts to work for oil supply, the main oil pressure regulating subsystem 2 is started accordingly. Under the action of the spring of the main spool 205, the main spool 205 is in the left position. At this time, the oil can quickly enter the oil paths of the main oil pressure regulating subsystem 2 and related subsystems under the drive of the pump, quickly filling the entire oil path network, establishing an initial oil pressure environment for the main oil pressure regulating subsystem 2 and subsequent subsystems relying on this oil pressure, and preparing for the normal operation of the system. As the first pump body 104 continues to work for oil supply, the oil in the system continuously increases and the pressure gradually rises. The system pressure acts on the pilot end (right side) of the main spool 205. The main spool 205 is affected by three forces. First, the hydraulic pressure generated by the system pressure, with the direction to the left, driving the main spool 205 to move to the left. It is affected by the spring force and the hydraulic pressure controlled by the solenoid valve VBS1, with the direction to the right, driving the main spool 205 to move to the right. Since the area of the pilot end of the main spool 205 is larger than the area of the spring end, when the system pressure gradually increases, the hydraulic pressure received by the pilot end will be relatively larger. Under the action of the hydraulic pressure, the main spool 205 begins to overcome the resistance of the spring end and move to the left. During the process of the main spool 205 moving to the left, the force on its left end (the sum of the spring force and the hydraulic pressure) and the force on its right end (the hydraulic pressure generated by the system pressure) gradually tend to be equal. When the forces on both sides reach equilibrium, the main spool 205 stops moving. At this time, the main spool 205 is in a dynamically balanced position, and the system pressure also stabilizes at this specific value, achieving precise adjustment of the main oil pressure of the system. Before the oil enters the solenoid valve VBS1, the first filter screen 201 will filter the hydraulic oil again, which can effectively intercept the possible impurities in the oil, further ensuring the cleanliness of the oil entering the solenoid valve VBS1 and preventing the solenoid valve VBS1 from getting stuck due to the impurities in the oil. By reducing the flow rate through the holes with the first throttle hole 202 and the second throttle hole 204, it plays a buffering role in the flow of the oil, thereby delaying the rapid change of the system state, reducing oscillation, and making the pressure control more gentle and stable.

[0027] Embodiment 3: A hydraulic control system for a hybrid transmission in this embodiment discloses the following technical content, which is convenient for realizing the rapid execution of the shifting action. For reference, please refer to the appendixFigure 1 - Attachment Figure 2 and attachment Figure 4 - Attachment Figure 5 When the shift fork is in the middle position, the shift piston 303 is also in the middle position. At this time, the shift control subsystem 3 is in a relatively static initial state, waiting for the trigger of the shift command. During the driving of the vehicle, when it is necessary to shift to the first gear, the system controls the solenoid valve VFS1 / NL to work. As the solenoid valve current increases, the spool inside the solenoid valve moves to the left, thereby changing the oil passage on-off state inside the solenoid valve and preparing for the hydraulic oil to enter the shift control subsystem 3. The hydraulic oil provided by the main oil pressure regulating subsystem 2 is filtered by the second filter screen 301 to remove impurities in the oil and ensure the cleanliness of the oil entering the shift control subsystem 3. The filtered hydraulic oil continues to pass through the shift valve VFS1 / NL, the third throttle hole 302 and the rear oil passage. The third throttle hole 302 plays a role in controlling the flow rate of the oil entering the subsequent shift control components (mainly the shift piston 303), enabling the oil to act on the shift piston 303 stably at an appropriate flow rate and avoiding the impact caused by sudden pressure changes on the piston. Under the action of the hydraulic pressure, the shift piston 303 starts to move to the left. Since the shift fork is connected to the shift piston 303 through a mechanical mechanism, the movement of the shift piston 303 will drive the shift fork to move synchronously, facilitating the shift from the current gear to the first gear, meeting the gear requirements under different working conditions of the vehicle, ensuring the power transmission efficiency. After the shift is completed, the shift piston 303 needs to return to its original position. The hydraulic oil flows out from the right oil passage of the shift piston 303 and passes through the fourth throttle hole 304. The fourth throttle hole 304 is used to control the flow rate of the oil when the shift piston 303 returns, enabling the oil return process to proceed smoothly and avoiding excessive system pressure fluctuations caused by too fast oil return. The oil return passes through the third filter screen 305 for filtration to remove impurities that may be mixed in the oil return and ensure the cleanliness of the oil return, so that it can be recycled normally in the future, realizing the rapid execution of the shift action.

[0028] When the shift fork is in the middle position, the shift piston 303 is also in the middle position. At this time, the shift control subsystem 3 is in a relatively static initial state, waiting for the trigger of the shift command. During the driving of the vehicle, when it is necessary to shift to the first gear, the system controls the solenoid valve VFS1 / NL to work. As the solenoid valve current increases, the spool inside the solenoid valve moves to the left, thereby changing the oil passage on-off state inside the solenoid valve and preparing for the hydraulic oil to enter the shift control subsystem 3. The hydraulic oil provided by the main oil pressure regulating subsystem 2 is filtered by the second filter screen 301 to remove impurities in the oil and ensure the cleanliness of the oil entering the shift control subsystem 3. The filtered hydraulic oil continues to pass through the shift valve VFS1 / NL, the third throttle hole 302 and the rear oil passage. The third throttle hole 302 plays a role in controlling the flow rate of the oil entering the subsequent shift control components (mainly the shift piston 303), enabling the oil to act on the shift piston 303 stably at an appropriate flow rate and avoiding the impact caused by sudden pressure changes on the piston. Under the action of the hydraulic pressure, the shift piston 303 starts to move to the left. Since the shift fork is connected to the shift piston 303 through a mechanical mechanism, the movement of the shift piston 303 will drive the shift fork to move synchronously, facilitating the shift from the current gear to the first gear, meeting the gear requirements under different working conditions of the vehicle, ensuring the power transmission efficiency. After the shift is completed, the shift piston 303 needs to return to its original position. The hydraulic oil flows out from the right oil passage of the shift piston 303 and passes through the fourth throttle hole 304. The fourth throttle hole 304 is used to control the flow rate of the oil when the shift piston 303 returns, enabling the oil return process to proceed smoothly and avoiding excessive system pressure fluctuations caused by too fast oil return. The oil return passes through the third filter screen 305 for filtration to remove impurities that may be mixed in the oil return and ensure the cleanliness of the oil return, so that it can be recycled normally in the future, realizing the rapid execution of the shift action.

[0029] Embodiment 4: A hydraulic control system for a hybrid transmission in this embodiment discloses the following technical content, facilitating the system to have functions of preventing impurity jamming, buffering pressure shock, dynamic feedback control, and closed-loop control. Reference can be made to the appended Figure 1 - appended Figure 2 and appended Figure 7 , the shift control subsystem 3 is connected to the clutch control subsystem 5 through an oil circuit to achieve the coordinated operation of shift and clutch control. The clutch control subsystem 5 includes a fourth filter screen 504, and the fourth filter screen 504 is installed on the oil circuit entering the clutch control subsystem 5 for filtering the oil entering the clutch control subsystem 5. The top of the oil circuit of the fourth filter screen 504 is respectively connected to a second accumulator body 502 and a pressure sensor body 503. A clutch body 501 is provided at the top between the second accumulator body 502 and the pressure sensor body 503. By controlling the oil pressure and flow rate of the oil entering the clutch body 501.

[0030] When the system needs to perform a shift operation or adjust the clutch state, the hydraulic oil provided by the main oil pressure regulation subsystem 2 enters the overall control oil circuit to provide a power source for the clutch control subsystem 5. The hydraulic oil first enters the oil circuit of the clutch control subsystem 5 and will be preliminarily filtered by the fourth filter screen 504 before entering, removing larger particle impurities in the oil to ensure that the oil entering the subsystem has a certain cleanliness. When the clutch body 501 is disengaged, the hydraulic oil in the piston chamber of the clutch body 501 needs to be drained. At this time, the hydraulic oil will flow back through the fourth filter screen 504 and then be drained through the control valve VFS of the clutch body 501. This design ensures that during the oil drainage process, impurities that may be generated due to component wear in the piston chamber of the clutch body 501 are intercepted by the filter screen and will not enter the control valve VFS of the clutch body 501, thus avoiding impurity jamming of the control valve and ensuring the normal operation of the control valve. A feedback loop is provided at the rear end of the control valve VFS of the clutch body 501, that is, a feedback oil circuit is provided at the spring end. When controlled by an electromagnetic valve, it can improve the accuracy of controlling the engagement and disengagement of the clutch body 501. At the same time, an accumulator is provided at the rear end of the control valve VFS of the clutch body 501. The second accumulator body 502 can absorb oil vibration and hydraulic shock caused by fluctuations in the main oil circuit, making the two states of engagement and disengagement of the clutch body 501 more stable. A pressure sensor body 503 is provided near the piston chamber of the clutch body 501 in this control oil circuit, and the measured pressure value is closer to the true value of the control pressure of the clutch body 501, providing more accurate data support for software closed-loop control, and realizing that the system has functions of preventing impurity jamming, buffering pressure shock, dynamic feedback control, and closed-loop control.

[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hydraulic control system for a hybrid transmission, comprising an oil supply subsystem (1), a main oil pressure regulation subsystem (2), a shift control subsystem (3), a lubrication and cooling subsystem (4), and a clutch control subsystem (5); It is characterized in that: The output end of the oil supply subsystem (1) is respectively connected to the main oil pressure regulation subsystem (2) and the lubrication and cooling subsystem (4) through a main oil circuit, providing hydraulic oil for the main oil pressure regulation and lubrication and cooling processes. The output end of the main oil pressure regulation subsystem (2) is respectively connected to the shift control subsystem (3) and the clutch control subsystem (5) through a main oil circuit; The oil supply subsystem (1) includes an oil tank (101) for storing hydraulic oil. A temperature sensor body (102) is provided at the bottom of the oil tank (101). An oil suction filter body (103) is provided inside the oil tank (101). The output end of the oil suction filter body (103) is respectively connected to the input ends of a first pump body (104) and a second pump body (105) through an oil circuit. A high-pressure filter body (106) is connected to the top of the first pump body (104).

2. The hydraulic control system for a hybrid transmission according to claim 1, wherein: A first safety valve body (107) is provided on the main oil circuit connecting the output end of the oil supply subsystem (1) to the main oil pressure regulation subsystem (2) and the shift control subsystem (3).

3. A hydraulic control system for a hybrid transmission according to claim 2, wherein: The main oil pressure regulation subsystem (2) includes a first filter screen (201) installed on the oil circuit entering the main oil pressure regulation subsystem (2). A first throttle hole (202) is provided at the top of the oil circuit of the first filter screen (201). A first accumulator body (203) is provided on the right side of the oil circuit of the first throttle hole (202); The main oil pressure regulation subsystem (2) further includes a second throttle hole (204) and a main spool valve (205). The main spool valve (205) is located at the pilot end on the left side of the second throttle hole (204).

4. The hydraulic control system for a hybrid transmission according to claim 3, characterized in that: The shift control subsystem (3) receives hydraulic oil from the main oil pressure regulation subsystem (2). The shift control subsystem (3) includes a second filter screen (301) installed on the oil circuit entering the shift control subsystem (3) for filtering the oil entering the shift control subsystem (3). A third throttle hole (302) is provided at the top of the oil circuit of the second filter screen (301) for controlling the oil flow rate entering the subsequent shift control components. A shift piston (303) is provided on the right side of the oil circuit of the third throttle hole (302). The shift piston (303) realizes a shift action under the action of hydraulic oil. A fourth throttle hole (304) is provided on the right side of the oil circuit of the shift piston (303) for controlling the oil flow rate when the shift piston (303) returns oil. A third filter screen (305) is provided at the bottom of the oil circuit of the fourth throttle hole (304) for filtering the return oil.

5. The hydraulic control system for a hybrid transmission according to claim 4, characterized in that, The shift control subsystem (3) is connected to the clutch control subsystem (5) through an oil circuit to achieve coordinated operation of shift and clutch control. The clutch control subsystem (5) includes a fourth filter screen (504). The fourth filter screen (504) is installed on the oil circuit entering the clutch control subsystem (5) and is used to filter the oil entering the clutch control subsystem (5). The top of the oil circuit of the fourth filter screen (504) is respectively connected to a second accumulator body (502) and a pressure sensor body (503). A clutch body (501) is arranged at the top between the second accumulator body (502) and the pressure sensor body (503), and the oil pressure and flow rate of the oil entering the clutch body (501) are controlled.

6. A hydraulic control system for a hybrid transmission according to claim 1, characterized in that: The oil supply subsystem (1) is connected to the lubrication and cooling subsystem (4) through an oil circuit and receives low-pressure oil from the second pump body (105). The lubrication and cooling subsystem (4) includes a second safety valve body (401) and an oil cooler body (402).

7. A hydraulic control system for a hybrid transmission according to claim 1, characterized in that: The first pump body (104) is set as a high-pressure pump for providing high-pressure oil, and the second pump body (105) is set as a low-pressure pump for providing low-pressure oil.

8. A hydraulic control system for a hybrid transmission according to claim 6, characterized in that: The lubrication and cooling subsystem (4) is connected to the second safety valve body (401) through an oil circuit, and the output end of the lubrication and cooling subsystem (4) is connected to the fuel tank (101) through an oil circuit. It is used to open when the oil pressure of the lubrication and cooling subsystem (4) exceeds the set value and drain the excess oil back to the fuel tank (101).

9. A hydraulic control system for a hybrid transmission according to claim 6, characterized in that: The lubrication and cooling subsystem (4) is connected to the oil cooler body (402) through an oil circuit and is used to cool the oil entering the lubrication and cooling subsystem (4).

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