New energy transmission hydraulic system and control method

Abstract

A new energy transmission hydraulic system and control method, belonging to the field of hydraulic transmission technology, comprising an oil supply mechanism, the oil supply mechanism is connected with the first pressure regulating valve group; the first pressure regulating valve group is connected with the second pressure regulating valve group and the third pressure regulating valve group arranged in parallel, the second pressure regulating valve group and the third pressure regulating valve group are connected with the shift fork control unit, 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, the first oil drain port is connected with the lubricating cooling oil circuit, the second oil drain port is connected with the oil supply mechanism, the mechanical pump bridge circuit is used in cooperation with the pressure regulating valve group and the shift fork control unit, the gear shifting and lubricating cooling functions of the new energy transmission can be realized, the displacement of the mechanical pump drive is large, which can meet the lubricating, cooling and gear shifting requirements, the action of the shift fork is directly driven through the cooperation of the shift fork control unit and the pressure regulating valve, the space occupation is smaller, and the gear expansion can be carried out as needed.

Description

TECHNICAL FIELD

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

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

[0003] The shift mechanism of the existing new energy transmission is controlled by a motor. After receiving the signal, the motor generates torque through internal electromagnetic conversion, and then uses shift drums and shift forks and other components to realize the switching of different gears to adapt to different driving conditions and improve the power performance and energy utilization efficiency of new energy vehicles.

[0004] The shift mechanism of the existing new energy transmission requires at least two motors and complex mechanical structures, which has a high use cost. When the number of gears needs to be increased, the number of motors and mechanical structures needs to be increased accordingly, which increases the cost and makes it difficult to expand the number of gears. In addition, the lubrication of the motors and other components in the existing new energy transmission is provided by an electronic pump. At present, the driving motor of new energy vehicles is gradually replaced by oil cooling cooling with better heat dissipation performance instead of water cooling cooling. The oil cooling cooling increases the demand for lubrication, and the existing electronic pump cannot guarantee the supply of flow. SUMMARY

[0005] To solve the technical problems of the existing new energy transmission shift mechanism using a motor to drive with complex mechanical structures, high cost and poor gear expansion, the present application provides a new energy transmission hydraulic system.

[0006] The technical scheme of the present application is as follows:

[0007] The application provides a new energy transmission hydraulic system, which comprises an oil supply mechanism, the oil supply mechanism is a mechanical pump bridge circuit, the oil supply mechanism is connected with a first pressure regulating valve group through a main hydraulic oil path, 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 through a secondary hydraulic oil path, the second pressure regulating valve group and the third pressure regulating valve group are connected with a shift fork control unit through a shift fork control oil path, and the shift fork control unit drives a 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 with a lubricating and cooling oil path, and the second oil drain port is connected with the oil supply mechanism; the mechanical pump bridge circuit is used in cooperation 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, so that the shift and lubricating and cooling functions of the new energy transmission can be realized, the mechanical pump is used for driving, the displacement is large, the lubricating, cooling and shifting requirements can be met, the action of the shift fork is no longer driven by a motor, but is directly driven through cooperation of the shift fork control unit and the pressure regulating valve, compared with the motor driving, the space occupation is smaller, the compactness is higher, and the gear expansion can be carried out as required.

[0008] Preferably, the first pressure regulating valve group comprises a first pressure regulating valve and a first pilot electromagnetic valve, the first pilot electromagnetic valve is connected with the first pressure regulating valve, an oil inlet of the first pressure regulating valve is connected with the main hydraulic oil path, the first pressure regulating valve comprises a first oil drain port and a second oil drain port, and an oil outlet of the first pressure regulating valve is connected with the second pressure regulating valve group and the third pressure regulating valve group through the secondary hydraulic oil path; the working state of the first pressure regulating valve is controlled through the first pilot electromagnetic valve, so that the oil pressure in the secondary hydraulic oil path is accurately regulated, a stable and suitable pressure oil source is provided for the work of the second pressure regulating valve group and the third pressure regulating valve group, the accuracy and stability of the system pressure control are ensured, and the control precision and reliability of the system are improved.

[0009] Preferably, the second pressure regulating valve group comprises a second pressure regulating valve and a second pilot electromagnetic valve, the second pressure regulating valve is connected with the secondary hydraulic oil path and the shift fork control oil path respectively, the second pilot electromagnetic valve is connected with the second pressure regulating valve, the second pressure regulating valve is controlled through the second pilot electromagnetic valve, the oil pressure and flow entering the shift fork control unit can be accurately regulated, the shift fork can accurately and stably perform the shift operation, the comfort and reliability of the shift are improved, the shift impact is reduced, and the service life of the transmission is prolonged.

[0010] Preferably, the third pressure regulating valve group comprises a third pressure regulating valve and a third pilot electromagnetic valve, the third pressure regulating valve is connected with the secondary hydraulic oil path and the shift fork control oil path respectively, the third pilot electromagnetic valve is connected with the third pressure regulating valve, the third pressure regulating valve group can accurately control the oil entering the shift fork control unit from another path, and cooperates with the second pressure regulating valve group to further improve the flexibility and reliability of the shift fork control.

[0011] Preferably, the first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group are connected with the pressure reducing valve to reduce the pressure and keep the pressure of the oil supply circuit within the range of the oil supply pressure allowed by the pilot electromagnetic valve.

[0012] 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. 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 backflow of the oil. The first oil port and the second oil port are connected with the oil tank through an oil suction circuit. A filter is arranged on the oil suction circuit to filter impurities in the oil, improve the cleanliness of the oil, reduce system wear and failure, and prolong the service life of the system. The filter is connected with the second oil drain port, and the oil flowing back can be filtered again to further ensure the quality of the oil and improve the reliability and stability of the system. The first oil port and the second oil port are also connected with the hydraulic main oil circuit.

[0013] 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 connected with 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 connected with the oil suction circuit. A mechanical pump bridge circuit is formed, which can supply oil normally when the mechanical pump rotates forward or reversely, improves the adaptability and reliability of the oil supply mechanism, ensures stable oil supply for the system under various working conditions, and enhances the stability and robustness of the entire hydraulic system.

[0014] Preferably, the shift fork control unit 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 with one of the two hydraulic chambers of the shift fork control unit. The two hydraulic chambers respectively receive oil from the second pressure regulating valve group and the third pressure regulating valve group. The piston can be smoothly moved by utilizing the pressure difference of the oil, and the shift fork can be accurately shifted. The overall structure is simple and reliable, which can effectively improve the accuracy and speed of shifting, enhance the shifting performance of the transmission and the driving experience, and facilitate the expansion of gears.

[0015] A control method of a new energy transmission hydraulic system, comprising:

[0016] 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 for pressure regulation. The oil with the increased oil pressure enters the hydraulic auxiliary oil circuit and is delivered to the second pressure regulating valve and the third pressure regulating valve. The oil flow and pressure entering different chambers of the shift fork control unit are controlled, and the shift fork is moved by the piston.

[0017] After the shift is completed, the first pressure regulating valve bleeds the oil in the main hydraulic oil circuit, the bled oil enters the lubricating and cooling oil circuit through the first oil drain port, and is delivered to the lubricating system through the lubricating and cooling oil circuit, and the excess oil is bled to the second oil drain port and discharged into the oil tank, through accurate control of the oil pressure and flow, efficient and stable shifting operation is realized, and after the shift is completed, the oil can be bled and distributed, which not only ensures the lubrication and cooling of the system, but also returns the excess oil to the tank, realizes the recycling of the oil and the efficient operation of the system, and improves the energy utilization efficiency and working reliability of the system.

[0018] Preferably, the mechanical pump pumps oil to the main hydraulic oil circuit when it is rotated forward or reversely, which increases the flexibility and reliability of oil supply, and even in some special working conditions or when the mechanical pump fails, the system can continue to be supplied with oil 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.

[0019] From the above technical solutions, it can be seen that the advantages of the present application are:

[0020] 1. The cooperation of the mechanical pump bridge circuit, 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 lubricating and cooling functions of the new energy transmission, the mechanical pump is used for driving, the displacement is large, and the lubricating, cooling and shifting requirements can be met, and the action of the shift fork is no longer driven by the motor, but directly driven by the cooperation of the shift fork control unit and the pressure regulating valve, which has smaller space occupation and higher compactness compared with the motor driving, and can expand the gear as needed.

[0021] 2. The first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group can accurately control the oil pressure and flow, realize efficient and stable shifting operation, and after the shift is completed, the oil can be bled and distributed, which not only ensures the lubrication and cooling of the system, but also returns the excess oil to the tank, realizes the recycling of the oil and the efficient operation of the system, and improves the energy utilization efficiency and working reliability of the system.

[0022] 3. The mechanical pump pumps oil to the main hydraulic oil circuit when it is rotated forward or reversely, which increases the flexibility and reliability of oil supply, and even in some special working conditions or when the mechanical pump fails, the system can continue to be supplied with oil 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 DRAWINGS

[0023] In order to make the technical solutions of the present application clearer, the drawings needed to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and all other embodiments obtained by those skilled in the art without any creative effort based on the drawings also fall within the protection scope of the present patent.

[0024] Figure 1 Fig. 1 is a hydraulic structure schematic diagram of a new energy transmission hydraulic system according to one or more embodiments of the present application.

[0025] The components represented by the reference numerals in the drawings are as follows:

[0026] 1, first check valve; 2, second check valve; 3, mechanical pump; 4, third check valve; 5, fourth check 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, oil tank; 16, lubrication system. DETAILED DESCRIPTION

[0027] In order to make the technical solutions of the present application clearer, the drawings needed to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and all other embodiments obtained by those skilled in the art without any creative effort based on the drawings also fall within the protection scope of the present patent.

[0028] Embodiment 1

[0029] In a typical embodiment of the present application, as Figure 1As shown, a new energy transmission hydraulic system is proposed, which comprises 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, which contains a mechanical pump 3. The mechanical pump 3 can realize oil supply function in both forward and reverse rotation. The oil supply mechanism is connected with the oil inlet of the first pressure regulating valve group through the hydraulic main oil path, 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 a first oil drain port and a second oil drain port. The first oil drain port is connected with the lubricating and cooling oil path, and is connected with the lubricating system 16 through the lubricating and cooling oil path. The second oil drain port is connected with the oil supply mechanism. The oil flow is preferentially drained to the first oil drain port, so as to be used for lubrication and cooling of the motor and other parts in the transmission by the lubricating system 16. When the flow of the first oil drain port reaches the demand, the oil is then drained to the second oil drain port. The oil outlet of the first pressure regulating valve group is connected with the second pressure regulating valve group and the third pressure regulating valve group through the hydraulic auxiliary oil path. The second pressure regulating valve group and the third pressure regulating valve group are connected with the shift fork control unit 13 through the shift fork control oil path. In this embodiment, the shift fork control unit 13 is a piston structure, which contains two hydraulic cavities. The two ends of the piston are slidingly arranged in the two hydraulic cavities. The second pressure regulating valve group and the third pressure regulating valve group are respectively connected with one hydraulic cavity of the shift fork control unit 13, that is, one hydraulic cavity of the shift fork control unit 13 is connected with the second pressure regulating valve group, and the other hydraulic cavity is connected with the third pressure regulating valve group. Thus, the pressure and flow supplied to the shift fork control unit 13 can be adjusted by the second pressure regulating valve group and the third pressure regulating valve group, and then the movement of the shift fork is controlled by the shift fork control unit 13, thereby realizing the shift function.

[0030] 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 path, so that the shift fork control unit quickly responds and drives the shift fork to act. In the working condition of frequent shift or quick shift of the vehicle, the shift can be more timely, the power interruption time is reduced, the power performance and driving experience of the vehicle are improved. The motor drive often needs to go through the processes of motor starting, speed increasing and transmission mechanism transmission, and the response is relatively slow. The hydraulic drive power output is more stable, which can reduce the shift impact, reduce the impact and wear of the internal gear and other parts of the transmission, prolong the service life of the transmission, and also improve the comfort of vehicle driving, avoiding passenger discomfort caused by shift impact.

[0031] In addition, the shift fork control unit 13 cooperates with the second and third pressure regulating valve groups to realize shift control, the overall structure is more compact, and the cost is low, and it is more convenient to expand. In the process of expanding the gear, the shift fork driven by the hydraulic pressure can realize smooth and accurate switching between different gears by accurately controlling the oil pressure and flow of the pressure regulating valve, the power transmission efficiency is high, the power interruption time is short during the shift process, and the performance will not be significantly reduced due to the increase of gears. At the same time, it has good compatibility with other hydraulic systems of the vehicle (such as the brake system, the steering assist system, etc.). When expanding the gear, some hydraulic elements and oil paths can be conveniently shared with these systems to realize the cooperative work between systems.

[0032] The oil supply mechanism includes a first check valve 1, a second check valve 2, a mechanical pump 3, a third check valve 4 and a fourth check valve 5, which are combined into a bridge circuit to realize oil supply to the hydraulic system by the mechanical pump 3 in both forward and reverse rotation. Specifically, the first check valve 1 and the second check valve 2 are arranged in parallel at the first oil port of the mechanical pump 3, and the third check valve 4 and the fourth check valve 5 are arranged in parallel at the second oil port of the mechanical pump 3, as shown in Figure 1 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 line, and the filter 14 is arranged on the oil suction line. The first oil port and the second oil port of the mechanical pump 3 are also connected to the main hydraulic oil line.

[0033] In this embodiment, the opening directions of the first check valve 1 and the second check valve 2 are opposite, and the opening directions of the third check valve 4 and the fourth check valve 5 are opposite. At the same time, the opening directions of the first check valve 1 and the fourth check valve 5 are opposite, and the opening ends of the first check valve 1 and the fourth check valve 5 are connected to the main hydraulic oil line for oil supply to the main hydraulic oil line. The opening directions of the second check valve 2 and the third check valve 4 are opposite, and the opening ends of the second check valve 2 and the third check valve 4 are connected to the oil suction line for oil suction from the oil tank 15.

[0034] 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 check valve 1 is less than the closing end pressure, the first check valve 1 is closed, the opening end pressure of the second check valve 2 is greater than the closing end pressure, the second check valve 2 is opened, the oil enters the mechanical pump 3 through the second check valve 2, the oil pumped out of the mechanical pump 3 generates positive pressure, the closing end pressure of the third check valve 4 is greater than the opening end pressure, the third check valve 4 is closed, the opening end pressure of the fourth check valve 5 is greater than the closing end pressure, the fourth check valve 5 is opened, and the oil enters the hydraulic main oil circuit through the fourth check valve 5; when the mechanical pump 3 reverses, the second oil port generates negative pressure, the opening end pressure of the fourth check valve 5 is less than the closing end pressure, the fourth check valve 5 is closed, the opening end pressure of the third check valve 4 is greater than the closing end pressure, the third check valve 4 is opened, the oil enters the mechanical pump 3 through the third check valve 4, the oil pumped out of the mechanical pump 3 generates positive pressure, the closing end pressure of the second check valve 2 is greater than the opening end pressure, the second check valve 2 is closed, the opening end pressure of the first check valve 1 is greater than the closing end pressure, the first check valve 1 is opened, and the oil enters the hydraulic main oil circuit through the first check valve 1, so that the mechanical pump 3 can supply oil to the hydraulic system in forward rotation and reverse rotation.

[0035] The first pressure regulating valve group can increase the main oil pressure in the hydraulic main oil circuit during gear shifting control, and decrease the main oil pressure after gear shifting is completed, so that the leaked oil enters the lubricating system 16 to lubricate and cool the motor and other components in the transmission, or the excess leaked oil is guided into the oil tank 15. Specifically, the first pressure regulating valve group includes a first pressure regulating valve 6 and a first pilot electromagnetic valve 7. The oil inlet of the first pressure regulating valve 6 is connected with the hydraulic main oil circuit. The first pressure regulating valve 6 includes a first oil outlet and a second oil outlet. The first pressure regulating valve 6 is used to leak the oil in the hydraulic main oil circuit to the first oil outlet and the second oil outlet to regulate the pressure. The first pilot electromagnetic valve 7 is connected with the first pressure regulating valve 6. The pressure regulation of the first pressure regulating valve 6 is realized by controlling the pilot pressure of the first pilot electromagnetic valve 7. The first oil outlet of the first pressure regulating valve 6 is connected with the lubricating system 16 through a lubricating and cooling oil circuit. The second oil outlet of the first pressure regulating valve 6 is connected with the filter 14, so that the excess lubricating oil is leaked back to the oil tank 15, and 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 with the second pressure regulating valve group and the third pressure regulating valve group which are arranged in parallel through a hydraulic secondary oil circuit.

[0036] The second pressure regulating valve group includes a second pressure regulating valve 11 and a second pilot electromagnetic valve 9. The second pressure regulating valve 11 is connected with the hydraulic auxiliary oil path and the shift fork control oil path respectively. The second pilot electromagnetic valve 9 is connected with the second pressure regulating valve 11. Specifically, the oil inlet of the second pressure regulating valve 11 is connected with the hydraulic auxiliary oil path. The oil outlet of the second pressure regulating valve 11 is connected with the shift fork control oil path. The oil pressure and flow rate of the shift fork control oil path supplied by the second pressure regulating valve 11 are adjusted by adjusting the pilot pressure of the second pilot electromagnetic valve 9. The third pressure regulating valve group includes a third pressure regulating valve 12 and a third pilot electromagnetic valve 10. The third pressure regulating valve 12 is connected with the hydraulic auxiliary oil path and the shift fork control oil path respectively. The third pilot electromagnetic valve 10 is connected with the third pressure regulating valve 12. Specifically, the oil inlet of the third pressure regulating valve 12 is connected with the hydraulic auxiliary oil path. The oil outlet of the third pressure regulating valve 12 is connected with the shift fork control oil path. The oil pressure and flow rate of the shift fork control oil path supplied by the third pressure regulating valve 12 are adjusted by adjusting the pilot pressure of the third pilot electromagnetic valve 10. The oil pressure of different chambers of the shift fork control unit 13 is controlled by the cooperation of the second pressure regulating valve 11 and the third pressure regulating valve 12, so as to control the movement of the piston, and the movement of the shift fork is controlled by the piston.

[0037] The first pressure regulating valve group, the second pressure regulating valve group and the third pressure regulating valve group are connected with the pressure reducing valve 8. Specifically, the oil inlet of the pressure reducing valve 8 is connected with the hydraulic auxiliary oil path. The oil outlet of the pressure reducing valve 8 is connected with the first pilot electromagnetic valve 7 of the first pressure regulating valve group, the second pilot electromagnetic valve 9 of the second pressure regulating valve group and the third pilot electromagnetic valve 10 of the third pressure regulating valve group respectively through the oil supply path, so as to reduce the pressure and keep the pressure of the oil supply path within the range of the oil supply pressure allowed by the pilot electromagnetic valve.

[0038] It can be understood that the first pilot electromagnetic valve 7, the pressure reducing valve 8, the second pilot electromagnetic valve 9, the third pilot electromagnetic valve 10, the second pressure regulating valve 11 and the third pressure regulating valve 12 are connected with the oil tank 15, so as to discharge the excess oil.

[0039] The cooperation of the mechanical pump bridge circuit and 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 gear shifting and lubrication and cooling functions of the new energy transmission, without the need of motor driving. The mechanical pump is adopted for driving, and the displacement is large, so as to meet the lubrication, cooling and gear shifting requirements. The action of the shift fork is no longer driven by the motor, but directly driven by the cooperation of the shift fork control unit 13 and the second pressure regulating valve 11 and the third pressure regulating valve 12. Compared with the motor driving, the space occupation is smaller, and the compactness is higher, so as to expand the gear as needed.

[0040] Embodiment 2

[0041] In another typical embodiment of the present application, a control method of a new energy transmission hydraulic system is provided. The specific process is as follows:

[0042] 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, 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, the oil pumped out of the mechanical pump 3 generates positive pressure, 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, 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 path through the fourth one-way valve 5; when the mechanical pump 3 reverses, the second oil port generates negative pressure, 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, the fourth one-way valve 5 is closed, 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, the oil enters the mechanical pump 3 through the third one-way valve 4, the oil pumped out of the mechanical pump 3 generates positive pressure, 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, the second one-way valve 2 is closed, 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 path through the first one-way valve 1;

[0043] After the oil supply mechanism pumps the oil into the hydraulic main oil path, the oil in the hydraulic main oil path enters the first pressure regulating valve 6 through the oil inlet, the first pilot electromagnetic valve 7 controls the first pressure regulating valve 6 by controlling the pilot pressure, and the oil pressure in the hydraulic main oil path is adjusted by the first pressure regulating valve 6, the oil with the increased oil pressure enters the hydraulic auxiliary oil path through the oil outlet, is transported to the second pressure regulating valve 11 and the third pressure regulating valve 12 through the hydraulic auxiliary oil path, and the second pilot electromagnetic valve 9 and the third pilot electromagnetic valve 10 work to control the corresponding second pressure regulating valve 11 and the third pressure regulating valve 12 by controlling the pilot pressure, so as 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 gear shifting;

[0044] After the gear shifting is completed, the first pressure regulating valve 6 drains the oil in the hydraulic main oil path to reduce the oil pressure in the hydraulic main oil path, the drained oil first enters the lubrication and cooling oil path through the first oil drain port, is transported to the lubrication system 16 through the lubrication and cooling oil path, and is used for lubrication and cooling of the motor and other parts in the transmission by the lubrication system 16, after the oil flow of the first oil drain port reaches the requirement, the excess oil is drained to the second oil drain port, is discharged to the filter 14 through the second oil drain port, and is finally discharged to the oil tank 15 after being filtered.

[0045] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded 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 a mechanical pump bridge circuit, and the oil supply mechanism is connected with the first pressure regulating valve group through a main hydraulic oil circuit; the oil supply mechanism comprises a mechanical pump (3), the mechanical pump (3) is provided with a first oil port and a second oil port, the first oil port is provided with a first check valve (1) and a second check valve (2) in parallel, the second oil port is provided with a third check valve (4) and a fourth check valve (5) in parallel, the first oil port and the second oil port are connected with an oil tank (15) through an oil suction oil circuit, the oil suction oil circuit is provided with a filter (14), the filter (14) is connected with a second oil drain port, and the first oil port and the second oil port are also connected with the main hydraulic oil circuit; The first pressure regulating valve group is connected with a second pressure regulating valve group and a third pressure regulating valve group arranged in parallel through a secondary hydraulic oil circuit, the second pressure regulating valve group and the third pressure regulating valve group are connected with a shift fork control unit (13) through a shift fork control oil circuit, and the shift fork control unit (13) drives a 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 with a lubricating and cooling oil circuit, and the second oil drain port is connected with 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 electromagnetic valve (7), the first pilot electromagnetic valve (7) is connected with the first pressure regulating valve (6), an oil inlet of the first pressure regulating valve (6) is connected with the main hydraulic oil circuit, the first pressure regulating valve (6) comprises the first oil drain port and the second oil drain port, and an oil outlet of the first pressure regulating valve (6) is connected with the second pressure regulating valve group and the third pressure regulating valve group through the secondary hydraulic 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 electromagnetic valve (9), the second pressure regulating valve (11) is connected with the secondary hydraulic oil circuit and the shift fork control oil circuit respectively, and the second pilot electromagnetic valve (9) is connected with 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 electromagnetic valve (10), the third pressure regulating valve (12) is connected with the secondary hydraulic oil circuit and the shift fork control oil circuit respectively, and the third pilot electromagnetic valve (10) is connected with 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 connected with a pressure reducing valve (8).

6. The new energy transmission hydraulic system according to claim 1, wherein, The opening directions of the first check valve (1) and the second check valve (2) are opposite, the opening directions of the third check valve (4) and the fourth check valve (5) are opposite, the opening directions of the first check valve (1) and the fourth check valve (5) are opposite, the opening ends of the first check valve (1) and the fourth check valve (5) are connected with the main hydraulic oil circuit, the opening directions of the second check valve (2) and the third check valve (4) are opposite, and the opening ends of the second check valve (2) and the third check valve (4) are connected with the oil suction oil circuit.

7. The new energy transmission hydraulic system according to claim 1, characterized in that, The shift fork control unit (13) is a piston structure and comprises two hydraulic cavities, the second pressure regulating valve group and the third pressure regulating valve group are connected with one hydraulic cavity of the shift fork control unit (13) respectively.

8. A control method for the new energy transmission hydraulic system according to any one of claims 1-7, characterized in that, The control method comprises: The oil supply mechanism pumps oil into the hydraulic main oil path, the oil in the hydraulic main oil path enters the first pressure regulating valve (6) for pressure regulation, the oil with the increased oil pressure enters the hydraulic auxiliary oil path, and is delivered to the second pressure regulating valve (11) and the third pressure regulating valve (12) through the hydraulic auxiliary oil path, so as to control the oil flow and pressure in different chambers of the shift fork control unit (13), and the shift fork is controlled to move through the piston. After the shift is completed, the first pressure regulating valve (6) bleeds the oil in the hydraulic main oil path, the bled oil enters the lubricating and cooling oil path through the first oil drain port, and is delivered to the lubricating system (16) through the lubricating and cooling oil path, and the excess oil is bled to the second oil drain port and discharged into the oil tank (15).

9. The control method according to claim 8, characterized by, The mechanical pump (3) pumps oil to the hydraulic main oil path when rotating forward or reversely.

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