8at automatic transmission hydraulic system

Abstract

An 8AT automatic transmission hydraulic system. The system comprising: a first pressure regulating valve (10), a second pressure regulating valve (12), a first switching valve (4), a main oil circuit (33), a first solenoid valve (6), a second solenoid valve (11), a third solenoid valve (23), a fourth solenoid valve (13), a fifth solenoid valve (8), and a sixth solenoid valve (22). The first solenoid valve and the fifth solenoid valve are connected to a forward oil circuit (32); the sixth solenoid valve is connected to the main oil circuit; the second solenoid valve and the fourth solenoid valve are connected to a pressure reducing oil circuit (35); the first solenoid valve, the fifth solenoid valve, the third solenoid valve and the sixth solenoid valve are direct-drive solenoid valves; the second solenoid valve and the fourth solenoid valve are pilot solenoid valves. The direct-drive solenoid valves and the pilot solenoid valves are used to control each clutch of a transmission, simplifying the design of the pressure regulating valve, and reducing space occupied thereby.

Description

8AT automatic transmission hydraulic system Technical Field

[0001] The present invention belongs to the technical field of automatic transmissions, and in particular relates to an 8AT automatic transmission hydraulic system. Background Art

[0002] 8AT automatic transmission refers to an automatic transmission with 8 forward gears.

[0003] In related technologies, 8AT automatic transmission hydraulic systems mostly use pilot solenoid valves and pressure regulating valves to control and adjust pressure, and switch valves to implement transmission failure modes, which have complex structures and high costs.

[0004] For example, the patent document with publication number CN107975594A discloses a hydraulic system of an automatic transmission, including a first failure valve, a second failure valve connected to the first failure valve, a normally high solenoid valve for controlling the first failure valve, a clutch system connected to the first failure valve, and a normally low solenoid valve for controlling the second failure valve and forming two failure gears.

[0005] Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an 8AT automatic transmission hydraulic system, the purpose of which is to improve the structural compactness.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an 8AT automatic transmission hydraulic system, including a first pressure regulating valve, a second pressure regulating valve, a first switching valve, a main oil circuit, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve and a main pressure regulating valve, the first solenoid valve and the fifth solenoid valve are connected to the forward gear oil circuit, the sixth solenoid valve is connected to the main oil circuit, the second solenoid valve and the fourth solenoid valve are connected to the pressure reducing oil circuit, the first solenoid valve, the fifth solenoid valve, the third solenoid valve and the sixth solenoid valve are direct-drive solenoid valves, the second solenoid valve and the fourth solenoid valve are pilot solenoid valves, the first pressure regulating valve is connected to the forward gear oil circuit and the C2 clutch of the 8AT automatic transmission, the third solenoid valve is connected to the C3 clutch of the 8AT automatic transmission, the second pressure regulating valve is connected to the forward gear oil circuit and the C4 clutch of the 8AT automatic transmission, the first switching valve is connected to the first solenoid valve and the start-stop oil circuit, and the start-stop oil circuit is configured to provide an oil source for the C1 clutch.

[0008] The decompression oil circuit is connected to the lock inhibiting valve, the TC solenoid valve is connected to the lock inhibiting valve, the shuttle valve is connected to the forward gear oil circuit and the reverse gear oil circuit, and the third solenoid valve is connected to the shuttle valve.

[0009] The shuttle valve has a first oil inlet, a second oil inlet and an oil outlet. The first oil inlet of the shuttle valve is connected to the forward gear oil circuit, the second oil inlet of the shuttle valve is connected to the reverse gear oil circuit, and the oil outlet of the shuttle valve is connected to the oil inlet of the third solenoid valve.

[0010] The oil inlet of the first pressure regulating valve is connected to the forward gear oil circuit, and the oil outlet of the first pressure regulating valve is connected to the C2 clutch.

[0011] The oil inlet of the second pressure regulating valve is connected to the forward gear oil circuit, and the oil outlet of the second pressure regulating valve is connected to the C4 clutch.

[0012] The start-stop oil circuit includes a start-stop pump, the first switching valve has a first oil inlet and a second oil inlet, the first oil inlet of the first switching valve is connected to the oil outlet of the first solenoid valve, and the second oil inlet of the first switching valve is connected to the oil outlet of the start-stop pump.

[0013] The pressure reducing oil circuit includes a pressure reducing valve, the oil inlet of the pressure reducing valve is connected to the main oil circuit, and the oil outlet of the pressure reducing valve is connected to the second solenoid valve and the fourth solenoid valve.

[0014] The main pressure regulating valve is connected to the P2 oil circuit, and the P2 oil circuit is configured to supply oil to the cooling lubricating oil circuit. The cooling lubricating oil circuit includes a cooling pressure regulating valve and an oil cooler. The cooling pressure regulating valve is connected to the PL solenoid valve. The PL solenoid valve is connected to the main pressure regulating valve and the pressure reducing oil circuit. The PL solenoid valve is a pilot solenoid valve.

[0015] The 8AT automatic transmission hydraulic system also includes a first pressure-maintaining valve, a second pressure-maintaining valve, a third pressure-maintaining valve, a fourth pressure-maintaining valve, a fifth pressure-maintaining valve, a sixth pressure-maintaining valve and a seventh pressure-maintaining valve. The first pressure-maintaining valve is located on the oil unloading circuit of the first solenoid valve, the second pressure-maintaining valve and the third pressure-maintaining valve are located on the oil unloading circuit of the C2 clutch, the fourth pressure-maintaining valve and the fifth pressure-maintaining valve are located on the oil unloading circuit of the C4 clutch, the sixth pressure-maintaining valve is located on the oil unloading circuit of the sixth solenoid valve, the seventh pressure-maintaining valve is located between the shuttle valve and the manual valve, and the seventh pressure-maintaining valve is configured to maintain pressure when unloading oil in the forward gear oil circuit.

[0016] The 8AT automatic transmission hydraulic system also includes a first accumulator, a second accumulator, a third accumulator, a fourth accumulator, a fifth accumulator, a sixth accumulator and a seventh accumulator. The first accumulator is located in the C1 clutch oil circuit and is used to buffer the pressure fluctuations of the C1 clutch oil circuit, the second accumulator is located in the B1 clutch oil circuit and is used to buffer the pressure fluctuations of the B1 clutch oil circuit, the third accumulator is located in the B2 clutch oil circuit and is used to buffer the pressure fluctuations of the B2 clutch oil circuit, the fourth accumulator is located in the C3 clutch oil circuit and is used to buffer the pressure fluctuations of the C3 clutch oil circuit, the fifth accumulator is located between the oil outlet of the second solenoid valve and the first pressure regulating valve and is used to buffer the pressure fluctuations of the C2 clutch oil circuit, the sixth accumulator is located between the oil outlet of the fourth solenoid valve and the second pressure regulating valve and is used to buffer the pressure fluctuations of the C4 clutch oil circuit, and the seventh accumulator is located between the oil outlet of the PL solenoid valve and the main pressure regulating valve and is used to buffer the pressure fluctuations of the main oil circuit.

[0017] The 8AT automatic transmission hydraulic system of the present invention adopts direct-drive solenoid valves and pilot solenoid valves to control each clutch of the transmission, utilizes two normally high pilot solenoid valves to realize the failure mode of the clutch, simplifies the design of the pressure regulating valve core, has a simple structure, compact design, has cost advantages, and reduces occupied space. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This manual includes the following drawings, which show the following contents:

[0019] FIG1 is a schematic structural diagram of the hydraulic system of an 8AT automatic transmission of the present invention;

[0020] The following are marked in the figure: 1. Oil pump; 2. Filter; 3. Solenoid pump; 4. First switching valve; 5. First accumulator; 6. First solenoid valve; 7. First pressure-holding valve; 8. Fifth solenoid valve; 9. Fifth accumulator; 10. First pressure-regulating valve; 11. Second solenoid valve; 12. Second pressure-regulating valve; 13. Fourth solenoid valve; 14. Cooling pressure-regulating valve; 15. Oil cooler; 16. Cooling back-pressure valve; 17. Check valve; 18. Cooling safety valve; 19. TC lock valve; 20. TC release valve; 21. TC solenoid valve; 22. Sixth solenoid valve; 23. Third solenoid valve; 24. Shuttle valve; 25. Manual valve; 26. Main pressure-regulating valve; 27. First filter; 28. Main oil circuit safety valve; 29. ​​Pressure reducing valve; 30. Lock inhibit valve. 31. PL solenoid valve; 32. Forward gear oil circuit; 33. Main oil circuit; 34. P2 oil circuit; 35. Pressure reducing oil circuit; 36. Cooling and lubricating oil circuit; 37. Pilot oil circuit; 38. Reverse gear oil circuit; 39. Start-stop oil circuit; 40. Second pressure-maintaining valve; 41. Third pressure-maintaining valve; 42. Fourth pressure-maintaining valve; 43. Fifth pressure-maintaining valve; 44. Sixth pressure-maintaining valve; 45. Seventh pressure-maintaining valve; 46. Second accumulator; 47. Third accumulator; 48. Fourth accumulator; 49. Sixth accumulator; 50. TC pressure-maintaining valve; 51. Second filter; 52. Pressure sensor; 53. Oil temperature sensor; 54. Seventh accumulator; 55. STC oil circuit. DETAILED DESCRIPTION

[0021] The following is a further detailed description of the specific implementation methods of the present invention through the description of embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and to facilitate its implementation.

[0022] It should be noted that, in the following embodiments, the "first", "second", "third", "fourth", "fifth", "sixth" and "seventh" do not represent an absolute distinction in structure and / or function, nor do they represent a sequence of execution, but are merely for the convenience of description.

[0023] As shown in Figure 1, the present invention provides an 8AT automatic transmission hydraulic system, including an oil pump 1, a start-stop pump 3, a main pressure regulating valve 26 connected to the oil pump 3, a forward gear oil circuit 32 connected to the manual valve 25, a main oil circuit 33 connected to the main pressure regulating valve 26, a P2 oil circuit 34 connected to the main pressure regulating valve 26, a pressure reducing oil circuit 35 connected to the pressure reducing valve 29, a cooling and lubricating oil circuit 36 ​​connected to the TC locking valve 19 and the TC release valve 20, a pilot oil circuit 37 connected to the PL solenoid valve 31, a reverse gear oil circuit 38 connected to the manual valve 25, and a start-stop oil circuit 39 connected to the start-stop pump 3.

[0024] Specifically, as shown in Figure 1 , the oil pump 1 is a gear pump; the first solenoid valve 6 , the fifth solenoid valve 8 , the third solenoid valve 23 , and the sixth solenoid valve 22 are direct-drive solenoid valves; the second solenoid valve 11 , the fourth solenoid valve 13 , the TC solenoid valve 21 , and the PL solenoid valve 31 are pilot solenoid valves. The first solenoid valve 6 and the fifth solenoid valve 8 are connected to the forward gear oil circuit 32 ; the sixth solenoid valve 22 is connected to the main oil circuit 33 ; the second solenoid valve 11 , the fourth solenoid valve 13 , and the PL solenoid valve 31 are connected to the pressure-reducing oil circuit 35 ; the lockup inhibiting valve 30 is connected to the pressure-reducing oil circuit 35 ; the TC solenoid valve 21 is connected to the lockup inhibiting valve 30 ; the shuttle valve 24 is connected to the forward gear oil circuit 32 and the reverse gear oil circuit 38 ; and the third solenoid valve is connected to the shuttle valve 24 . By adjusting the corresponding solenoid valves, the corresponding clutches within the transmission can be controlled to engage and release, achieving commands for forward gears 1 through 8, as well as park, neutral, and reverse.

[0025] As shown in Figure 1 , the oil inlet of the first pressure regulating valve 10 is connected to the forward gear oil circuit 32, and the oil outlet of the first pressure regulating valve 10 is connected to the C2 clutch of the 8AT automatic transmission. The oil inlet of the second pressure regulating valve 12 is connected to the forward gear oil circuit 32, and the oil outlet of the second pressure regulating valve 12 is connected to the C4 clutch of the 8AT automatic transmission.

[0026] As shown in Figure 1, the first switching valve 4 has a first oil inlet, a second oil inlet, a control port and an oil outlet. The first oil inlet of the first switching valve 4 is connected to the oil outlet of the first solenoid valve 6, and the second oil inlet of the first switching valve 4 is connected to the oil outlet of the start-stop pump 3 through the start-stop oil circuit.

[0027] As shown in FIG1 , the oil inlet of the pressure reducing valve 29 is connected to the main oil circuit 33 , and the oil outlet of the pressure reducing valve 29 is connected to the pressure reducing oil circuit 35 .

[0028] As shown in Figure 1, the shuttle valve 24 has a first oil inlet, a second oil inlet and an oil outlet. The first oil inlet of the shuttle valve 24 is connected to the forward gear oil circuit 32, the second oil inlet of the shuttle valve 24 is connected to the reverse gear oil circuit 38, and the oil outlet of the shuttle valve 24 is connected to the oil inlet of the third solenoid valve 23.

[0029] As shown in FIG. 1 , the oil inlet of the cooling pressure regulating valve 14 is connected to the cooling lubricating oil circuit 36 ​​, and the oil outlet of the cooling pressure regulating valve 14 is connected to the oil cooler 15 .

[0030] As shown in Figure 1 , the oil inlet of the lockup inhibition valve 30 is connected to the pressure reducing oil circuit 35, while the oil outlet of the lockup inhibition valve 30 is connected to the oil inlet of the TC solenoid valve 21. The oil inlet of the TC lockup valve 19 is connected to the main oil circuit 33, while the oil outlet of the TC lockup valve 19 is connected to the TC coupling end (the coupling end of the torque converter). The oil inlet of the TC release valve 20 is connected to the P2 oil circuit 34, while the oil outlet of the TC release valve 20 is connected to the TC release end.

[0031] As shown in Figure 1, when the transmission is in D gear, the manual valve 25 is in the leftmost position, and the main oil circuit 33 is connected to the forward gear oil circuit 32. The forward gear oil circuit 32 is connected to the oil inlet of the first solenoid valve 6, the oil inlet of the fifth solenoid valve 8, the oil inlet of the first pressure regulating valve 10, the oil inlet of the second pressure regulating valve 12, and the first oil inlet of the shuttle valve 24. The forward gear oil circuit 32 pushes the steel ball inside the shuttle valve 24 to the right end. At this time, the forward gear oil circuit 32 can be connected to the oil inlet of the third solenoid valve 23 through the shuttle valve 24. After pressure regulation by the main pressure regulating valve 26, the main oil circuit 33 enters the first filter 27 and the second filter 51, and is connected to the oil inlet of the pressure reducing valve 29. The oil outlet of the pressure reducing valve 29 is connected to the fourth solenoid valve 13.

[0032] Main oil circuit 33 pushes the valve core of main pressure regulating valve 26 rightward through the control port at the rightmost end of main pressure regulating valve 26, connecting main oil circuit 33 to P2 oil circuit 34. The rightmost end of the valve core of main pressure regulating valve 26 is connected to pilot oil circuit 37. The valve core of main pressure regulating valve 26 maintains equilibrium under the influence of three forces: the pressure of main oil circuit 33 at the leftmost end of the valve core, the spring force at the rightmost end of the valve core, and the pressure of pilot oil circuit 37. By adjusting the current of PL solenoid valve 31, the pressure of pilot oil circuit 37 is controlled to achieve the purpose of regulating the oil pressure of main oil circuit 33. The pressure range of main oil circuit 33 is set at 0-18.3 bar. Pressure sensor 52 can monitor the oil pressure of main oil circuit 33. Main oil circuit 33 is equipped with main oil circuit safety valve 28 to prevent system overload and abnormal operation.

[0033] As shown in Figure 1, when the transmission is in D gear, the forward gear oil circuit 32 provides oil source to the first solenoid valve 6, the fifth solenoid valve 8, and the third solenoid valve 23, a total of three direct-drive solenoid valves. By adjusting the current of the corresponding solenoid valve, the oil circuit pressure entering the corresponding clutch can be controlled.

[0034] The pressure-reducing oil circuit 35 supplies oil to four pilot solenoid valves: the second solenoid valve 11, the third solenoid valve 13, the PL solenoid valve 31, and the TC solenoid valve 21. By adjusting the current flowing through each solenoid valve, the oil pressure entering the corresponding clutch can be controlled. The valve core of the pressure-reducing valve 29 is balanced by the oil pressure in the pressure-reducing oil circuit 35 at its leftmost end and the spring force at its rightmost end. The pressure-reducing valve 29 controls the pressure in the pressure-reducing oil circuit 35 to 7.8 bar or below, accommodating the pressure regulation range of the pilot solenoid valves, which ranges from 7.8 to 0 bar or from 0 to 7.8 bar. The main oil circuit 33 supplies oil to the sixth solenoid valve 22, which is connected to the B2 clutch of the automatic transmission. By adjusting the current flowing through the sixth solenoid valve 22, the oil pressure entering the B2 clutch of the automatic transmission can be controlled.

[0035] As shown in Figure 1, the first accumulator 5 is located in the C1 clutch oil circuit and is used to buffer pressure fluctuations in the C1 clutch oil circuit, which is connected to the C1 clutch. The second accumulator 46 is located in the B1 clutch oil circuit and is used to buffer pressure fluctuations in the B1 clutch oil circuit, which is connected to the B1 clutch. The third accumulator 47 is located in the B2 clutch oil circuit and is used to buffer pressure fluctuations in the B2 clutch oil circuit, which is connected to the B2 clutch. The fourth accumulator 48 is located in the C3 clutch oil circuit and is used to buffer pressure fluctuations in the C3 clutch oil circuit, which is connected to the C3 clutch. The fifth accumulator 9 is located between the oil outlet of the second solenoid valve 11 and the first pressure regulating valve 10 and is used to buffer pressure fluctuations in the C2 clutch oil circuit, which is connected to the C2 clutch. The sixth accumulator 49 is located between the oil outlet of the fourth solenoid valve 13 and the second pressure regulating valve 12 and is used to buffer pressure fluctuations in the C4 clutch oil circuit, which is connected to the C4 clutch. The seventh accumulator 54 is located between the oil outlet of the PL solenoid valve 31 and the main pressure regulating valve 26 to buffer pressure fluctuations in the main oil circuit. The function of the pressure-maintaining valve is to ensure that the oil circuit is always filled with oil, thereby increasing the response speed of the system.

[0036] As shown in Figure 1, the first pressure-maintaining valve 7 is located on the oil unloading circuit of the first solenoid valve 6, the second pressure-maintaining valve 40 and the third pressure-maintaining valve 41 are located on the C2 clutch oil unloading circuit, the fourth pressure-maintaining valve 42 and the fifth pressure-maintaining valve 43 are located on the C4 clutch oil unloading circuit, the sixth pressure-maintaining valve 44 is located on the oil unloading circuit of the sixth solenoid valve 22, and the seventh pressure-maintaining valve 45 is located between the shuttle valve 24 and the manual valve 25. The seventh pressure-maintaining valve is used to maintain pressure when unloading oil in the forward gear oil circuit 32.

[0037] As shown in Figure 1, the cooling and lubricating oil circuit 36 ​​is equipped with a cooling safety valve 18. This valve controls the maximum pressure in the cooling and lubricating oil circuit 36, protecting the system from normal operation. The cooling and lubricating oil circuit 36 ​​enters the oil cooler 15 after being regulated by the cooling pressure regulating valve 14. When the valve core of the cooling pressure regulating valve 14 maintains equilibrium between the pressure in the cooling and lubricating oil circuit 36 ​​at its leftmost end and the pressure in the pilot oil circuit 37 connected to its rightmost end, the pressure in the cooling and lubricating oil circuit 36 ​​can be controlled by adjusting the current in the PL solenoid valve 31. After passing through the oil cooler 15, the cooling and lubricating oil circuit 36 ​​enters the front and rear transmission mechanisms. If the oil cooler 15 becomes blocked, the cooling oil circuit passes through the bypass oil circuit and, via the check valve 16, enters the front and rear transmission mechanisms.

[0038] As shown in Figure 1, when the TC solenoid valve 21 is de-energized, the P2 oil circuit 34 connects to the oil inlet of the TC release valve 20, supplying oil to the TC release end. At this point, the TC is in the released state. The difference in area between the left and right ends of the TC release valve 20's oil inlet chamber creates a rightward pressure differential. The valve core of the TC release valve 20 maintains equilibrium due to the pressure differential in the oil inlet chamber and the spring force at the rightmost end. When the TC solenoid valve 21 is energized, the valve core of the TC release valve 20 moves rightward under the pressure of the STC oil circuit 55. The P2 oil circuit 34 is disconnected from the rear end of the TC release valve 20, and the valve core of the TC lock valve 19 moves leftward under the pressure of the STC oil circuit 55. The main oil circuit 33 connects to the oil inlet of the TC lock valve 19, supplying oil to the TC engagement end. The TC (torque converter) is now in the engaged state. The valve core of the TC locking valve 19 maintains balance under the action of the pressure of the leftmost TC joint end, the spring force and the pressure of the STC oil passage 55 on the rightmost side of the valve core.

[0039] As shown in Figure 1, when the transmission is in R gear, manual valve 25 is in the third position from the left, connecting main oil circuit 33 to reverse oil circuit 38. Reverse oil circuit 38 is connected to the second oil inlet of shuttle valve 24. Reverse oil circuit 38 pushes the steel ball inside shuttle valve 24 to the left, connecting reverse oil circuit 38 to third solenoid valve 23 through shuttle valve 24. When sixth solenoid valve 22 is energized, the valve core of lockup inhibit valve 30 moves leftward under the pressure of the B2 clutch oil circuit, disconnecting pressure relief oil circuit 35 from the oil inlet of TC solenoid valve 21. This prevents accidental TC engagement when the B2 clutch is engaged in forward first gear, park, neutral, or reverse gears.

[0040] As shown in Figure 1, when the engine is turned off in D gear, start-stop pump 3 is energized, drawing oil from the fuel tank, through filter 2, and into start-stop oil circuit 39. With the engine turned off and oil pump 1 inoperative, there is no pressure in main oil circuit 33 at the control port of first switching valve 4. The valve core of first switching valve 4 moves to the right under the force of the left spring. At this point, start-stop oil circuit 39 connects to the C1 clutch oil circuit, providing oil to the C1 clutch, causing the C1 clutch to engage. After the engine is ignited, pressure in main oil circuit 33 begins to build, causing the valve core of first switching valve 4 to move leftward. The oil source for the C1 clutch oil circuit is switched to the outlet of first solenoid valve 6, resulting in a rapid system response, ensuring the forward gear C1 clutch is engaged.

[0041] As shown in Figure 1, the second solenoid valve 12 and the fourth solenoid valve 13 are normally high pilot solenoid valves. When the TCU (automatic transmission control unit) fails, the second solenoid valve 12 controls the C2 clutch to engage, and the fourth solenoid valve 13 controls the C4 clutch to engage, and the transmission enters the 6th gear mode to prevent further damage to the transmission and ensure that the owner can smoothly drive the vehicle to the maintenance point for repair.

[0042] In this embodiment, the automatic transmission is an 8AT automatic transmission.

[0043] The 8AT automatic transmission hydraulic system with the above structure has the following advantages:

[0044] (1) The advantage of the simple structure of the direct-drive solenoid valve to control the transmission clutch is fully utilized, the application of the switch solenoid valve is eliminated, and the characteristics of the normally high solenoid valve are directly used to control the transmission to enter the clutch corresponding to the failure gear, which greatly simplifies the valve body structure design;

[0045] (2) A pressure-maintaining valve is used to improve the system response speed. An accumulator is installed in the clutch oil circuit to buffer the oil circuit pressure fluctuation, making the pressure control more stable and improving driving comfort;

[0046] (3) While ensuring functionality, the system is simplified as much as possible, reducing the use of a large number of pressure regulating valves and switching slide valves, eliminating the use of valve core return springs in some pressure regulating valves, simplifying the valve core design, making the design compact and cost-effective;

[0047] (4) Simplifying the valve body oil circuit design and reducing the valve body leakage points can better provide cooling and lubrication for the planetary gear mechanism of the gearbox and protect the normal operation of the gearbox.

[0048] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described method. Any non-substantial improvements made using the method concepts and technical solutions of the present invention, or any direct application of the above-described concepts and technical solutions to other situations without modification, fall within the scope of protection of the present invention.

Claims

1. 8AT automatic transmission hydraulic system, characterized by: It includes a first pressure regulating valve, a second pressure regulating valve, a first switching valve, a main oil circuit, a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve and a main pressure regulating valve. The first solenoid valve and the fifth solenoid valve are connected to the forward gear oil circuit, the sixth solenoid valve is connected to the main oil circuit, the second solenoid valve and the fourth solenoid valve are connected to the pressure reducing oil circuit, the first solenoid valve, the fifth solenoid valve, the third solenoid valve and the sixth solenoid valve are direct-drive solenoid valves, the second solenoid valve and the fourth solenoid valve are pilot solenoid valves, the first pressure regulating valve is connected to the forward gear oil circuit and the C2 clutch, the third solenoid valve is connected to the C3 clutch, the second pressure regulating valve is connected to the forward gear oil circuit and the C4 clutch, the first switching valve is connected to the first solenoid valve and the start-stop oil circuit, and the start-stop oil circuit is configured to provide an oil source for the C1 clutch.

2. The 8AT automatic transmission hydraulic system according to claim 1, characterized in that: The decompression oil circuit is connected to the lock inhibiting valve, the TC solenoid valve is connected to the lock inhibiting valve, the shuttle valve is connected to the forward gear oil circuit and the reverse gear oil circuit, and the third solenoid valve is connected to the shuttle valve.

3. The 8AT automatic transmission hydraulic system according to claim 2, characterized in that: The shuttle valve has a first oil inlet, a second oil inlet and an oil outlet. The first oil inlet of the shuttle valve is connected to the forward gear oil circuit, the second oil inlet of the shuttle valve is connected to the reverse gear oil circuit, and the oil outlet of the shuttle valve is connected to the oil inlet of the third solenoid valve.

4. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: The oil inlet of the first pressure regulating valve is connected to the forward gear oil circuit, and the oil outlet of the first pressure regulating valve is connected to the C2 clutch.

5. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: The oil inlet of the second pressure regulating valve is connected to the forward gear oil circuit, and the oil outlet of the second pressure regulating valve is connected to the C4 clutch.

6. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: The start-stop oil circuit includes a start-stop pump, the first switching valve has a first oil inlet and a second oil inlet, the first oil inlet of the first switching valve is connected to the oil outlet of the first solenoid valve, and the second oil inlet of the first switching valve is connected to the oil outlet of the start-stop pump.

7. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: The pressure reducing oil circuit includes a pressure reducing valve, wherein the oil inlet of the pressure reducing valve is connected to the main oil circuit, and the oil outlet of the pressure reducing valve is connected to the second solenoid valve and the fourth solenoid valve.

8. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: The main pressure regulating valve is connected to the P2 oil circuit, and the P2 oil circuit is configured to supply oil to the cooling lubricating oil circuit. The cooling lubricating oil circuit includes a cooling pressure regulating valve and an oil cooler. The cooling pressure regulating valve is connected to the PL solenoid valve, and the PL solenoid valve is connected to the main pressure regulating valve and the pressure reducing oil circuit. The PL solenoid valve is a pilot solenoid valve.

9. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: It also includes a first pressure-maintaining valve, a second pressure-maintaining valve, a third pressure-maintaining valve, a fourth pressure-maintaining valve, a fifth pressure-maintaining valve, a sixth pressure-maintaining valve and a seventh pressure-maintaining valve. The first pressure-maintaining valve is located on the oil unloading circuit of the first solenoid valve, the second pressure-maintaining valve and the third pressure-maintaining valve are located on the oil unloading circuit of the C2 clutch, the fourth pressure-maintaining valve and the fifth pressure-maintaining valve are located on the oil unloading circuit of the C4 clutch, the sixth pressure-maintaining valve is located on the oil unloading circuit of the sixth solenoid valve, the seventh pressure-maintaining valve is located between the shuttle valve and the manual valve, and the seventh pressure-maintaining valve is configured to maintain pressure when unloading oil in the forward gear oil circuit.

10. The 8AT automatic transmission hydraulic system according to any one of claims 1 to 3, characterized in that: It also includes a first accumulator, a second accumulator, a third accumulator, a fourth accumulator, a fifth accumulator, a sixth accumulator and a seventh accumulator. The first accumulator is located in the C1 clutch oil circuit and is used to buffer the pressure fluctuation of the C1 clutch oil circuit. The second accumulator is located in the B1 clutch oil circuit and is used to buffer the pressure fluctuation of the B1 clutch oil circuit. The third accumulator is located in the B2 clutch oil circuit and is used to buffer the pressure fluctuation of the B2 clutch oil circuit. The fourth accumulator is located in the C3 clutch oil circuit and is used to buffer the pressure fluctuation of the C3 clutch oil circuit. The fifth accumulator is located between the oil outlet of the second solenoid valve and the first pressure regulating valve and is used to buffer the pressure fluctuation of the C2 clutch oil circuit. The sixth accumulator is located between the oil outlet of the fourth solenoid valve and the second pressure regulating valve and is used to buffer the pressure fluctuation of the C4 clutch oil circuit. The seventh accumulator is located between the oil outlet of the PL solenoid valve and the main pressure regulating valve and is used to buffer the pressure fluctuation of the main oil circuit.

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