New energy transmission hydraulic system and control method

Abstract

The invention discloses a new energy transmission hydraulic system and a control method, and belongs to the technical field of hydraulic transmission. The first pressure regulating valve group is connected with a second pressure regulating valve group and a third pressure regulating valve group which are arranged in parallel, the second pressure regulating valve group and the third pressure regulating valve group are both connected with a shifting fork control unit, and the shifting fork control unit drives a shifting fork to move; the first pressure regulating valve set is provided with a first oil drainage port and a second oil drainage port, the first oil drainage port is connected with the lubricating and cooling oil way, the second oil drainage port is connected with the oil supply mechanism, the mechanical pump bridge type loop is used in cooperation with the pressure regulating valve sets and the gear shifting fork control unit, and the gear shifting and lubricating and cooling functions of the new energy transmission can be achieved; the mechanical pump is large in driving displacement, the requirements for lubrication, cooling and gear shifting can be met, the gear shifting fork is directly driven through cooperation of the gear shifting fork control unit and the pressure regulating valve, occupied space is smaller, and gear expansion can be conducted according to needs.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic transmission, and in particular to a new energy transmission hydraulic system and a control method. Background Art

[0002] New energy vehicles refer to vehicles that use new power systems and are completely or mainly driven by new energy. They have the characteristics of energy saving, environmental protection, and advanced technology. New energy vehicles are divided into pure electric vehicles, hybrid vehicles, and fuel cell vehicles. New energy transmissions are a key component of the new energy vehicle power system and play an important role in the vehicle's power transmission and performance.

[0003] The shift mechanism of the existing new energy transmission is controlled by an electric motor. After receiving the signal, the motor generates torque through its internal electromagnetic conversion, and then uses components such as the shift drum and shift fork to achieve switching between different gears to adapt to different driving conditions and improve the power performance and energy utilization efficiency of new energy vehicles.

[0004] The shifting mechanism of the existing new energy transmission requires at least two motors and a complex mechanical structure, and has a high cost of use. When the gear position needs to be increased, the number of motors and mechanical structures needs to be increased accordingly, which greatly increases the cost and makes it difficult to expand the gear position. In addition, the lubrication of the motors and other components in the existing new energy transmission is provided by electronic pumps, and the current new energy drive motors are gradually replaced by oil cooling with better heat dissipation performance instead of water cooling. The demand for lubrication for oil cooling has increased, and the existing electronic pumps are difficult to guarantee the supply of flow. Summary of the invention

[0005] In order to solve the technical problems in the above background technology that the existing new energy transmission shift mechanism adopts a motor with a complex mechanical structure to drive, which is high in cost and has poor gear expansion, the present invention provides a new energy transmission hydraulic system.

[0006] The technical solution of the present invention is as follows: The present invention provides a new energy transmission hydraulic system, including an oil supply mechanism, which is a mechanical pump bridge circuit, and the oil supply mechanism is connected to a first pressure regulating valve group through a hydraulic main oil circuit; the first pressure regulating valve group is connected to a second pressure regulating valve group and a third pressure regulating valve group arranged in parallel through a hydraulic auxiliary oil circuit, and the second pressure regulating valve group and the third pressure regulating valve group are both connected to a shift fork control unit through a shift fork control oil circuit, and the shift fork control unit drives the shift fork to move; the first pressure regulating valve group is provided with a first oil drain port and a second oil drain port, and the first oil drain port is connected to a lubrication cooling oil circuit, The second oil drain port is connected to the oil supply mechanism, and the mechanical pump bridge circuit is used in conjunction with the first pressure regulating valve group, the second pressure regulating valve group, the third pressure regulating valve group and the shift fork control unit to realize the shifting and lubrication and cooling functions of the new energy transmission. It is driven by a mechanical pump with a large displacement to meet the lubrication, cooling and shifting requirements, and the movement of the shift fork is no longer driven by a motor, but directly driven by the cooperation of the shift fork control unit and the pressure regulating valve. Compared with motor drive, it occupies less space and is more compact, and the gear position can be expanded as needed.

[0007] Preferably, the first pressure regulating valve group includes a first pressure regulating valve and a first pilot solenoid valve, the first pilot solenoid valve is connected to the first pressure regulating valve, the oil inlet of the first pressure regulating valve is connected to the hydraulic main oil circuit, the first pressure regulating valve has a first oil drain port and a second oil drain port, the oil outlet of the first pressure regulating valve is connected to the second pressure regulating valve group and the third pressure regulating valve group through a hydraulic auxiliary oil circuit, and the working state of the first pressure regulating valve is controlled by the first pilot solenoid valve, thereby achieving precise regulation of the oil pressure of the hydraulic main oil circuit entering the hydraulic auxiliary oil circuit, providing a stable and suitable pressure oil source for the subsequent operation of the second pressure regulating valve group and the third pressure regulating valve group, ensuring the accuracy and stability of the pressure control of the entire system, and improving the control accuracy and reliability of the system.

[0008] Preferably, the second pressure regulating valve group includes a second pressure regulating valve and a second pilot solenoid valve, the second pressure regulating valve is respectively connected to the hydraulic auxiliary oil circuit and the shift fork control oil circuit, the second pilot solenoid valve is connected to the second pressure regulating valve, and the second pressure regulating valve is controlled by the second pilot solenoid valve. The oil pressure and flow entering the shift fork control unit can be accurately adjusted to ensure that the shift fork can perform shift operations accurately and smoothly, thereby improving the comfort and reliability of shifting, reducing shifting shock, and extending the service life of the transmission.

[0009] Preferably, the third pressure regulating valve group includes a third pressure regulating valve and a third pilot solenoid valve, the third pressure regulating valve is respectively connected to the hydraulic auxiliary oil circuit and the fork control oil circuit, the third pilot solenoid valve is connected to the third pressure regulating valve, the third pressure regulating valve group can accurately control the oil entering the shift fork control unit from another route, and work in coordination with the second pressure regulating valve group, thereby further improving the flexibility and reliability of the shift fork control.

[0010] Preferably, the first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group are all connected to the pressure reducing valve to reduce the pressure and keep the pressure of the oil supply circuit within the oil supply pressure range allowed by the pilot solenoid valve.

[0011] Preferably, the oil supply mechanism includes a mechanical pump, which provides a stable oil source, and the oil supply is sufficient and stable. The mechanical pump is provided with a first oil port and a second oil port. The first oil port is provided with a first one-way valve and a second one-way valve in parallel, and the second oil port is provided with a third one-way valve and a fourth one-way valve in parallel. The one-way valves at the first oil port and the second oil port can change the flow direction of the oil as needed and prevent the oil from flowing back. The first oil port and the second oil port are both connected to the oil tank through an oil suction line. A filter is provided on the oil suction line, which can filter impurities in the oil, improve the cleanliness of the oil, reduce system wear and failure, and extend the service life of the system. The filter is connected to the second oil drain port, and can also filter the leaked oil again to further ensure the oil quality and improve the reliability and stability of the system. The first oil port and the second oil port are also connected to the hydraulic main oil circuit.

[0012] Preferably, the opening directions of the first one-way valve and the second one-way valve are opposite, the opening directions of the third one-way valve and the fourth one-way valve are opposite, and the opening directions of the first one-way valve and the fourth one-way valve are opposite, the opening ends of the first one-way valve and the fourth one-way valve are both connected to the hydraulic main oil circuit, the opening directions of the second one-way valve and the third one-way valve are opposite, and the opening ends of the second one-way valve and the third one-way valve are both connected to the oil suction circuit, forming a mechanical pump bridge circuit, which can supply oil normally when the mechanical pump is rotating forward or reverse, improves the adaptability and reliability of the oil supply mechanism, ensures that a stable oil supply can be provided to the system under various working conditions, and enhances the stability and robustness of the entire hydraulic system.

[0013] Preferably, the shift fork control unit is a piston structure containing two hydraulic chambers. The second pressure regulating valve group and the third pressure regulating valve group are respectively connected to a hydraulic chamber of the shift fork control unit, and oil from the second pressure regulating valve group and the third pressure regulating valve group are respectively received through the two hydraulic chambers. The oil pressure difference can be used to achieve smooth movement of the piston, thereby driving the shift fork to shift accurately. The overall structure is simple and reliable, which can effectively improve the accuracy and speed of shifting, enhance the shifting performance and driving experience of the transmission, and facilitate the expansion of gears.

[0014] A control method for a new energy transmission hydraulic system, comprising: The oil supply mechanism pumps the oil into the hydraulic main oil circuit, and the oil in the hydraulic main oil circuit enters the first pressure regulating valve for pressure regulation. The oil after the oil pressure is increased enters the hydraulic auxiliary oil circuit, and is transported to the second pressure regulating valve and the third pressure regulating valve through the hydraulic auxiliary oil circuit to control the oil flow and pressure in different chambers of the shift fork control unit, and controls the movement of the shift fork through the piston; After the gear shift is completed, the first pressure regulating valve discharges the oil in the hydraulic main oil circuit, and the discharged oil enters the lubrication and cooling oil circuit through the first oil drain port, and is transported to the lubrication system through the lubrication and cooling oil circuit. The excess oil discharges to the second oil drain port, and is discharged into the oil tank through the second oil drain port. Through the precise control of the oil pressure and flow, efficient and smooth gear shifting operation is achieved. At the same time, after the gear shift is completed, the oil can be discharged and distributed, which not only ensures the lubrication and cooling of the system, but also returns the excess oil to the oil tank, thereby realizing the recycling of the oil and the efficient operation of the system, and improving the energy utilization efficiency and working reliability of the system.

[0015] Preferably, the mechanical pump pumps oil to the hydraulic main oil circuit when rotating forward or reverse, which increases the flexibility and reliability of oil supply. Even in certain special working conditions or when the mechanical pump fails, it can continue to supply oil to the system by changing the direction, ensuring the continuous and stable operation of the hydraulic system and improving the adaptability and fault tolerance of the entire new energy transmission hydraulic system.

[0016] It can be seen from the above technical solutions that the advantages of the present invention are: 1. The use of a mechanical pump bridge circuit in conjunction with the first pressure regulating valve group, the second pressure regulating valve group, the third pressure regulating valve group and the shift fork control unit can realize the shifting and lubrication and cooling functions of the new energy transmission. It is driven by a mechanical pump with a large displacement, which can meet the lubrication, cooling and shifting requirements. The movement of the shift fork is no longer driven by a motor, but is directly driven by the shift fork control unit and the pressure regulating valve. Compared with motor drive, it occupies less space and is more compact, and can expand the gear position as needed.

[0017] 2. Through the setting of the first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group, the oil pressure and flow can be accurately controlled, and efficient and smooth gear shifting operation can be achieved. At the same time, after the gear shift is completed, the oil can be drained and distributed, which not only ensures the lubrication and cooling of the system, but also returns the excess oil to the oil tank, realizing the recycling of the oil and the efficient operation of the system, and improving the energy utilization efficiency and working reliability of the system.

[0018] 3. The mechanical pump pumps oil to the main hydraulic oil circuit when rotating forward or reverse, which increases the flexibility and reliability of oil supply. Even in certain special working conditions or when the mechanical pump fails, it can continue to supply oil to the system by changing the direction, ensuring the continuous and stable operation of the hydraulic system and improving the adaptability and fault tolerance of the entire new energy transmission hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the hydraulic structure of a new energy transmission hydraulic system according to one or more embodiments of the present invention; The components represented by the reference numerals in the figure are: 1. First one-way valve; 2. Second one-way valve; 3. Mechanical pump; 4. Third one-way valve; 5. Fourth one-way valve; 6. First pressure regulating valve; 7. First pilot solenoid valve; 8. Pressure reducing valve; 9. Second pilot solenoid valve; 10. Third pilot solenoid valve; 11. Second pressure regulating valve; 12. Third pressure regulating valve; 13. Shift fork control unit; 14. Filter; 15. Fuel tank; 16. Lubrication system. DETAILED DESCRIPTION

[0021] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0022] Example 1 In a typical embodiment of the present invention, Figure 1As shown, a new energy transmission hydraulic system is proposed, including: an oil supply mechanism, a first pressure regulating valve group, a second pressure regulating valve group, a third pressure regulating valve group and a shift fork control unit 13, the oil supply mechanism is a mechanical pump bridge circuit, the oil supply mechanism contains a mechanical pump 3, the forward and reverse rotation of the mechanical pump 3 can realize the oil supply function, the oil supply mechanism is connected to the oil inlet of the first pressure regulating valve group through the hydraulic main oil circuit, so as to adjust the oil pressure through the first pressure regulating valve group, the first pressure regulating valve group contains two oil drain ports, namely the first oil drain port and the second oil drain port, wherein the first oil drain port is connected to the lubrication and cooling oil circuit, and is connected to the lubrication system 16 through the lubrication and cooling oil circuit, and the second oil drain port is connected to the oil supply mechanism, and the oil flows to the first oil drain port first, so as to be used for the lubrication and cooling of the motor and other components in the transmission by the lubrication system 16, and when the flow rate of the first oil drain port reaches the demand Then it leaks to the second oil drain port; the oil outlet of the first pressure regulating valve group is connected to the second pressure regulating valve group and the third pressure regulating valve group through the hydraulic auxiliary oil circuit, and the second pressure regulating valve group and the third pressure regulating valve group are both connected to the shift fork control unit 13 through the fork control oil circuit. In this embodiment, the shift fork control unit 13 is a piston structure, containing two hydraulic chambers, and the two ends of the piston are slidably arranged in the two hydraulic chambers. The second pressure regulating valve group and the third pressure regulating valve group are respectively connected to a hydraulic chamber of the shift fork control unit 13, that is, one hydraulic chamber of the shift fork control unit 13 is connected to the second pressure regulating valve group, and the other hydraulic chamber is connected to the third pressure regulating valve group, so that the second pressure regulating valve group and the third pressure regulating valve group can be used to adjust the pressure and flow supplied to the shift fork control unit 13, and then the shift fork control unit 13 controls the movement of the shift fork, thereby realizing the shifting function.

[0023] The shift fork control unit 13 cooperates with the second pressure regulating valve group and the third pressure regulating valve group to realize shift control. The pressure regulating valve can quickly change the pressure and flow in the oil circuit, so that the shift fork control unit responds quickly and drives the shift fork to move. Under conditions where the vehicle frequently shifts gears or needs to shift gears quickly, the gear shift can be more timely, the power interruption time can be reduced, and the vehicle's power performance and driving experience can be improved. The motor drive often needs to go through processes such as motor starting, speed increase, and transmission mechanism transmission, and the response is relatively slow. The hydraulic drive power output is smoother, which can reduce the gear shift shock, reduce the impact and wear on components such as gears inside the transmission, and extend the service life of the transmission. At the same time, it can also improve the driving comfort of the vehicle and avoid passenger discomfort caused by gear shift shock.

[0024] In addition, the shift fork control unit 13 cooperates with the second pressure regulating valve group and the third pressure regulating valve group to realize shift control. The overall structure is more compact, low-cost, and easier to expand. In the process of expanding the gear, the hydraulically driven shift fork can achieve smooth and accurate switching between different gears by relying on the precise control of the oil pressure and flow by the pressure regulating valve. The power transmission efficiency is high, and the power interruption time is short during the shifting process. There will be no obvious performance degradation due to the increase in gears. At the same time, it has good compatibility with other hydraulic systems of the vehicle (such as the braking system, power steering system, etc.). When expanding the gear, it can conveniently share some hydraulic components and oil circuits with these systems to achieve coordinated work between systems.

[0025] The oil supply mechanism includes a first one-way valve 1, a second one-way valve 2, a mechanical pump 3, a third one-way valve 4 and a fourth one-way valve 5. The first one-way valve 1, the second one-way valve 2, the mechanical pump 3, the third one-way valve 4 and the fourth one-way valve 5 are combined into a bridge circuit to realize that the mechanical pump 3 can supply oil to the hydraulic system in both forward and reverse rotation. Specifically, the first one-way valve 1 and the second one-way valve 2 are arranged in parallel at the first oil port of the mechanical pump 3, and the third one-way valve 4 and the fourth one-way valve 5 are arranged in parallel at the second oil port of the mechanical pump 3. Figure 1 As shown, the oil supply mechanism also includes an oil tank 15 and a filter 14. The first oil port and the second oil port of the mechanical pump 3 are connected to the oil tank 15 through an oil suction circuit. The filter 14 is arranged on the oil suction circuit. The first oil port and the second oil port of the mechanical pump 3 are also connected to the hydraulic main oil circuit.

[0026] In this embodiment, the opening directions of the first one-way valve 1 and the second one-way valve 2 are opposite, and the opening directions of the third one-way valve 4 and the fourth one-way valve 5 are opposite. At the same time, the opening directions of the first one-way valve 1 and the fourth one-way valve 5 are opposite, and the opening ends of the first one-way valve 1 and the fourth one-way valve 5 are both connected to the hydraulic main oil circuit for supplying oil to the hydraulic main oil circuit; the opening directions of the second one-way valve 2 and the third one-way valve 4 are opposite, and at the same time, the opening ends of the second one-way valve 2 and the third one-way valve 4 are both connected to the oil suction circuit for sucking oil from the oil tank 15.

[0027] In use, when the mechanical pump 3 rotates forward, the first oil port of the mechanical pump 3 generates negative pressure, the opening end pressure of the first one-way valve 1 is less than the closing end pressure, the first one-way valve 1 is closed, and the opening end pressure of the second one-way valve 2 is greater than the closing end pressure, the second one-way valve 2 is opened, the oil enters the mechanical pump 3 through the second one-way valve 2, and the oil pumped out by the mechanical pump 3 generates positive pressure. At this time, the closing end pressure of the third one-way valve 4 is greater than the opening end pressure, the third one-way valve 4 is closed, and the opening end pressure of the fourth one-way valve 5 is greater than the closing end pressure, the fourth one-way valve 5 is opened, and the oil enters the hydraulic main oil circuit through the fourth one-way valve 5; when the mechanical pump 3 is reversed , the second oil port generates negative pressure. At this time, the opening end pressure of the fourth one-way valve 5 is less than the closing end pressure, the fourth one-way valve 5 is closed, and the opening end pressure of the third one-way valve 4 is greater than the closing end pressure, the third one-way valve 4 is opened, and the oil enters the mechanical pump 3 through the third one-way valve 4. The oil pumped out by the mechanical pump 3 generates positive pressure. At this time, the closing end pressure of the second one-way valve 2 is greater than the opening end pressure, the second one-way valve 2 is closed, and the opening end pressure of the first one-way valve 1 is greater than the closing end pressure, the first one-way valve 1 is opened, and the oil enters the hydraulic main oil circuit through the first one-way valve 1, so that the mechanical pump 3 can supply oil to the hydraulic system in both forward and reverse rotation.

[0028] When the first pressure regulating valve group performs shift control, it can increase the main oil pressure in the hydraulic main oil circuit, and lower the main oil pressure after the shift is completed. The leaked oil enters the lubrication system 16 to lubricate and cool the motor and other components in the transmission, or guides the excess leaked oil to the oil tank 15. Specifically, the first pressure regulating valve group includes a first pressure regulating valve 6 and a first pilot solenoid valve 7. The oil inlet of the first pressure regulating valve 6 is connected to the hydraulic main oil circuit. The first pressure regulating valve 6 has a first oil drain port and a second oil drain port. The first pressure regulating valve 6 is used to drain the oil in the hydraulic main oil circuit to the first oil drain port and the second oil drain port. The first pressure regulating valve 6 is connected to the first pilot solenoid valve 7 to achieve pressure regulation. The first pilot solenoid valve 7 is connected to the first pressure regulating valve 6. The pressure regulation of the first pressure regulating valve 6 is achieved by controlling the pilot pressure of the first pilot solenoid valve 7. The first oil drain port of the first pressure regulating valve 6 is connected to the lubrication system 16 through the lubrication cooling oil circuit. The second oil drain port of the first pressure regulating valve 6 is connected to the filter 14, so as to drain the excess lubricating oil back to the oil tank 15. At the same time, the filter 14 is used to filter the oil to ensure the cleanliness of the oil. The oil outlet of the first pressure regulating valve 6 is connected to the second pressure regulating valve group and the third pressure regulating valve group arranged in parallel through the hydraulic auxiliary oil circuit.

[0029] The second pressure regulating valve group includes a second pressure regulating valve 11 and a second pilot solenoid valve 9. The second pressure regulating valve 11 is connected to the hydraulic auxiliary oil circuit and the fork control oil circuit respectively. The second pilot solenoid valve 9 is connected to the second pressure regulating valve 11. Specifically, the oil inlet of the second pressure regulating valve 11 is connected to the hydraulic auxiliary oil circuit, and the oil outlet of the second pressure regulating valve 11 is connected to the fork control oil circuit. By adjusting the pilot pressure of the second pilot solenoid valve 9, the oil pressure and flow rate of the second pressure regulating valve 11 supplied to the fork control oil circuit are adjusted; the third pressure regulating valve group includes a third pressure regulating valve 12 and a third pilot solenoid valve 10. The third pressure regulating valve 12 is connected to the hydraulic auxiliary oil circuit and the fork control oil circuit respectively. The hydraulic auxiliary oil circuit is connected to the fork control oil circuit, and the third pilot solenoid valve 10 is connected to the third pressure regulating valve 12. Specifically, the oil inlet of the third pressure regulating valve 12 is connected to the hydraulic auxiliary oil circuit, and the oil outlet of the third pressure regulating valve 12 is connected to the fork control oil circuit. By adjusting the pilot pressure of the third pilot solenoid valve 10, the oil pressure and flow rate of the shift fork control oil circuit supplied by the third pressure regulating valve 12 are adjusted. Through the coordinated use of the second pressure regulating valve 11 and the third pressure regulating valve 12, the oil pressure in different chambers of the shift fork control unit 13 can be controlled, thereby controlling the movement of the piston to control the movement of the shift fork through the piston.

[0030] The first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group are all connected to the pressure reducing valve 8. Specifically, the oil inlet of the pressure reducing valve 8 is connected to the hydraulic auxiliary oil circuit, and the oil outlet of the pressure reducing valve 8 is respectively connected to the first pilot solenoid valve 7 of the first pressure regulating valve group, the second pilot solenoid valve 9 of the second pressure regulating valve group, and the third pilot solenoid valve 10 of the third pressure regulating valve group through the oil supply oil circuit to play a role of reducing pressure and keep the pressure of the oil supply oil circuit within the oil supply pressure range allowed by the pilot solenoid valve.

[0031] It can be understood that the first pilot solenoid valve 7 , the pressure reducing valve 8 , the second pilot solenoid valve 9 , the third pilot solenoid valve 10 , the second pressure regulating valve 11 and the third pressure regulating valve 12 are all connected to the oil tank 15 for discharging excess oil.

[0032] By using a mechanical pump bridge circuit in conjunction with the first pressure regulating valve group, the second pressure regulating valve group, the third pressure regulating valve group and the shift fork control unit, the shifting and lubrication and cooling functions of the new energy transmission can be realized. No motor drive is required. A mechanical pump drive is used with a large displacement to meet the lubrication, cooling and shifting requirements. The movement of the shift fork is no longer driven by a motor, but is directly driven by the shift fork control unit 13 in conjunction with the second pressure regulating valve 11 and the third pressure regulating valve 12. Compared with motor drive, it occupies less space and is more compact, and the gear position can be expanded as needed.

[0033] Example 2 In another typical embodiment of the present invention, a control method for a new energy transmission hydraulic system is proposed, and the specific process is as follows: When the mechanical pump 3 rotates forward, the first oil port of the mechanical pump 3 generates negative pressure, the opening end pressure of the first one-way valve 1 is less than the closing end pressure of the first one-way valve 1, the first one-way valve 1 is closed, and the opening end pressure of the second one-way valve 2 is greater than the closing end pressure of the second one-way valve 2, the second one-way valve 2 is opened, the oil enters the mechanical pump 3 through the second one-way valve 2, and the oil pumped out by the mechanical pump 3 generates positive pressure. At this time, the closing end pressure of the third one-way valve 4 is greater than the opening end pressure of the third one-way valve 4, the third one-way valve 4 is closed, and the opening end pressure of the fourth one-way valve 5 is greater than the closing end pressure of the fourth one-way valve 5, the fourth one-way valve 5 is opened, and the oil enters the hydraulic main oil circuit through the fourth one-way valve 5 When the mechanical pump 3 reverses, the second oil port generates negative pressure. At this time, the opening end pressure of the fourth one-way valve 5 is less than the closing end pressure of the fourth one-way valve 5, and the fourth one-way valve 5 is closed, while the opening end pressure of the third one-way valve 4 is greater than the closing end pressure of the third one-way valve 4. The third one-way valve 4 is opened, and the oil enters the mechanical pump 3 through the third one-way valve 4. The oil pumped out by the mechanical pump 3 generates positive pressure. At this time, the closing end pressure of the second one-way valve 2 is greater than the opening end pressure of the second one-way valve 2, and the second one-way valve 2 is closed, while the opening end pressure of the first one-way valve 1 is greater than the closing end pressure of the first one-way valve 1. The first one-way valve 1 is opened, and the oil enters the hydraulic main oil circuit through the first one-way valve 1; After the oil supply mechanism pumps the oil into the hydraulic main oil circuit, the oil in the hydraulic main oil circuit enters the first pressure regulating valve 6 through the oil inlet, and the first pilot solenoid valve 7 controls the first pressure regulating valve 6 by controlling the pilot pressure. The first pressure regulating valve 6 is used to increase the oil pressure in the hydraulic main oil circuit, and the oil with increased oil pressure enters the hydraulic auxiliary oil circuit through the oil outlet, and is transported to the second pressure regulating valve 11 and the third pressure regulating valve 12 through the hydraulic auxiliary oil circuit. The second pilot solenoid valve 9 and the third pilot solenoid valve 10 work, and control the corresponding second pressure regulating valve 11 and the third pressure regulating valve 12 by controlling the pilot pressure to control the oil flow and pressure entering different chambers of the shift fork control unit 13, and then control the movement of the shift fork through the piston to complete the shift; After the gear shift is completed, the first pressure regulating valve 6 discharges the oil in the hydraulic main oil circuit to reduce the oil pressure in the hydraulic main oil circuit. The discharged oil first enters the lubrication and cooling oil circuit through the first oil drain port, and is transported to the lubrication system 16 through the lubrication and cooling oil circuit, so as to be used by the lubrication system 16 to lubricate and cool the motor and other components in the transmission. After the oil discharge flow rate of the first oil drain port reaches the requirement, the excess oil is discharged to the second oil drain port, and is discharged to the filter 14 through the second oil drain port for filtration, and finally the filtered oil is discharged into the oil tank 15. The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A new energy transmission hydraulic system, comprising: The oil supply mechanism is characterized in that the oil supply mechanism is a mechanical pump bridge circuit, and the oil supply mechanism is connected to the first pressure regulating valve group through a hydraulic main oil circuit; The first pressure regulating valve group is connected to a second pressure regulating valve group and a third pressure regulating valve group arranged in parallel via a hydraulic auxiliary oil circuit, the second pressure regulating valve group and the third pressure regulating valve group are both connected to a shift fork control unit (13) via a shift fork control oil circuit, and the shift fork control unit (13) drives the shift fork to move; The first pressure regulating valve group is provided with a first oil drain port and a second oil drain port. The first oil drain port is connected to the lubrication cooling oil circuit, and the second oil drain port is connected to the oil supply mechanism.

2. The new energy transmission hydraulic system according to claim 1, characterized in that: The first pressure regulating valve group comprises a first pressure regulating valve (6) and a first pilot solenoid valve (7), the first pilot solenoid valve (7) being connected to the first pressure regulating valve (6), an oil inlet of the first pressure regulating valve (6) being connected to a hydraulic main oil circuit, the first pressure regulating valve (6) comprising a first oil drain port and a second oil drain port, and an oil outlet of the first pressure regulating valve (6) being connected to the second pressure regulating valve group and the third pressure regulating valve group via a hydraulic auxiliary oil circuit.

3. The new energy transmission hydraulic system according to claim 1, characterized in that: The second pressure regulating valve group comprises a second pressure regulating valve (11) and a second pilot solenoid valve (9); the second pressure regulating valve (11) is connected to the hydraulic auxiliary oil circuit and the shift fork control oil circuit respectively; and the second pilot solenoid valve (9) is connected to the second pressure regulating valve (11).

4. The new energy transmission hydraulic system according to claim 1, characterized in that: The third pressure regulating valve group comprises a third pressure regulating valve (12) and a third pilot solenoid valve (10); the third pressure regulating valve (12) is connected to the hydraulic auxiliary oil circuit and the shift fork control oil circuit respectively; and the third pilot solenoid valve (10) is connected to the third pressure regulating valve (12).

5. The new energy transmission hydraulic system according to claim 1, characterized in that: The first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group are all connected to the pressure reducing valve (8).

6. The new energy transmission hydraulic system according to claim 1, characterized in that: The oil supply mechanism comprises a mechanical pump (3), the mechanical pump (3) being provided with a first oil port and a second oil port, a first check valve (1) and a second check valve (2) being provided in parallel at the first oil port, a third check valve (4) and a fourth check valve (5) being provided in parallel at the second oil port, the first oil port and the second oil port being connected to an oil tank (15) via an oil suction oil circuit, a filter (14) being provided on the oil suction oil circuit, the filter (14) being connected to the second oil drain port, and the first oil port and the second oil port being connected to a hydraulic main oil circuit.

7. The new energy transmission hydraulic system according to claim 6, characterized in that: The opening directions of the first one-way valve (1) and the second one-way valve (2) are opposite, the opening directions of the third one-way valve (4) and the fourth one-way valve (5) are opposite, and the opening directions of the first one-way valve (1) and the fourth one-way valve (5) are opposite. The opening ends of the first one-way valve (1) and the fourth one-way valve (5) are both connected to the main hydraulic oil circuit. The opening directions of the second one-way valve (2) and the third one-way valve (4) are opposite, and the opening ends of the second one-way valve (2) and the third one-way valve (4) are both connected to the oil suction oil circuit.

8. The new energy transmission hydraulic system according to claim 1, characterized in that: The shift fork control unit (13) is a piston structure and contains two hydraulic chambers; the second pressure regulating valve group and the third pressure regulating valve group are respectively connected to one hydraulic chamber of the shift fork control unit (13).

9. A control method, using the new energy transmission hydraulic system according to any one of claims 1 to 8, characterized in that: Control methods include: The oil supply mechanism pumps oil into the hydraulic main oil circuit, the oil in the hydraulic main oil circuit enters the first pressure regulating valve (6) for pressure regulation, the oil after the oil pressure is increased enters the hydraulic auxiliary oil circuit, and is transported to the second pressure regulating valve (11) and the third pressure regulating valve (12) through the hydraulic auxiliary oil circuit, thereby controlling the oil flow and pressure in different chambers of the shift fork control unit (13), and controlling the movement of the shift fork through the piston; After the gear shift is completed, the first pressure regulating valve (6) discharges the oil in the hydraulic main oil circuit, and the discharged oil enters the lubrication and cooling oil circuit through the first oil drain port, and is transported to the lubrication system (16) through the lubrication and cooling oil circuit. Excess oil flows to the second oil drain port and is discharged into the oil tank (15) through the second oil drain port.

10. The control method according to claim 9, characterized in that: The mechanical pump (3) pumps oil into the main hydraulic circuit when rotating forward or reverse.

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