Hybrid transmission high dynamic response pressure regulating oil circuit

Abstract

A high dynamic response pressure regulating oil circuit for a hybrid transmission belongs to the technical field of DHT hybrid transmissions. A secondary pressure source is connected to the C1 clutch control solenoid valve, C2 clutch control solenoid valve, B2 brake control solenoid valve, and B1 brake control solenoid valve via oil circuit b, supplying hydraulic oil. The C1, C2, B2, and B1 clutch control solenoid valves, through oil circuit c, can apply the hydraulic oil pressure to the action surfaces of four main pressure regulating valves. The main pressure source is connected to the four main pressure regulating valves via oil circuit a. The four main pressure regulating valves are connected to the B1 brake, B2 brake, C2 clutch, and C1 clutch via oil circuit d. Under the action of oil circuit c, the main pressure regulating valves connect oil circuit a and oil circuit d, and the hydraulic oil acts on the corresponding brakes and clutches. This invention features a compact structure, utilizes a direct-flow oil circuit, and achieves high dynamic oil pressure response through a high-flow control method.

Description

Technical Field

[0001] This invention belongs to the field of DHT hybrid transmission technology, specifically relating to a high dynamic response pressure regulating oil circuit for a hybrid transmission. Background Technology

[0002] The ultimate goal of new energy vehicles is undoubtedly pure electric. However, the development of pure electric vehicles is influenced by many factors, including battery energy density, charging technology, user acceptance, the construction of charging infrastructure, and power supply structure. New energy vehicles can be analyzed from two perspectives. First, for new energy passenger vehicles, since batteries and motors have largely met the range limitations, the pace of electrification will accelerate further, and market penetration will be faster. However, for vehicles with high load capacities, such as buses, light trucks, and heavy trucks, which require high torque, long driving ranges, and even higher battery energy density, as well as charging technology that needs to address high-power issues, pure electric vehicles will have a longer development period. Hybrid and multi-gear hybrid models will be the main technological route for the foreseeable future. In the transmission structure of hybrid electric vehicles, the DHT (Dual-Mode) hybrid transmission is the most ideal hybrid solution. Its advantages lie in the coordination of dual motors, providing multiple gears for different operating conditions, increasing engine efficiency, and offering a compact and low-cost transmission with significant advantages in efficiency and fuel economy.

[0003] The multi-speed DHT hybrid transmission includes parallel mode, pure electric mode, series mode, ECVT mode and other modes and gears. During gear and mode switching, the responsiveness of the multi-speed DHT hydraulic system is more demanding than that of the traditional AT shift control. Therefore, it is necessary to design a highly responsive pressure regulating oil circuit. Summary of the Invention

[0004] The purpose of this invention is to provide a high dynamic response pressure regulating oil circuit for a hybrid transmission.

[0005] The technical solution adopted in this invention is: a high dynamic response pressure regulating oil circuit for a hybrid transmission, comprising a main pressure source, a secondary pressure source, four accumulators, and four main pressure regulating valves; the secondary pressure source is connected to the C1 clutch control solenoid valve, C2 clutch control solenoid valve, B2 brake control solenoid valve, and B1 brake control solenoid valve via oil circuit b and supplies hydraulic oil; the C1 clutch control solenoid valve, C2 clutch control solenoid valve, B2 brake control solenoid valve, and B1 brake control solenoid valve can apply the hydraulic oil pressure to the working surfaces of the four main pressure regulating valves via oil circuit c; the main pressure source is connected to the four main pressure regulating valves via oil circuit a; the four main pressure regulating valves are connected to the B1 brake, B2 brake, C2 clutch, and C1 clutch via oil circuit d respectively; the main pressure regulating valves connect oil circuit a and oil circuit d under the action of oil circuit c, and the hydraulic oil acts on the corresponding brakes and clutches.

[0006] Compared with the prior art, the present invention has the following advantages:

[0007] This invention features a compact structure and utilizes a direct-flow oil circuit and a high-flow-rate control method to achieve high dynamic oil pressure response. This patented invention is applicable to multi-gear DHT hybrid power transmissions with multiple sets of power transmission friction elements, supporting rapid and smooth switching between multiple modes in DHT hybrid power transmissions. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of the present invention;

[0009] Figure 2 This is a schematic diagram of the main pressure regulating valve structure of the present invention;

[0010] Figure 3 This is a horizontal cross-sectional view of the oil hole in this invention;

[0011] The components are: 1. Main pressure source; 2. Secondary pressure source; 3. Accumulator; 4. C1 clutch control solenoid valve; 5. C2 clutch control solenoid valve; 6. B2 brake control solenoid valve; 7. B1 brake control solenoid valve; 8. Limit plug; 9. Pressure regulating valve core; 10. B1 brake; 11. B2 brake; 12. C2 clutch; 13. C1 clutch; 14. Valve body; 15. Spring; 16. Snap ring; 18. Main pressure regulating valve; 19. Oil port c; 20. Oil port a; 21. Oil port d; 22. Oil port e. Detailed Implementation

[0012] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0013] Each set of friction element control oil circuits consists of a solenoid valve, a pressure regulating valve core, and a spring assembly. Depending on the number of clutches required for the DHT gear, the corresponding control oil circuit can be achieved by multiple combinations. That is, it can be a single pressure regulating oil circuit, multiple pressure regulating oil circuits, or a combination of two to achieve a fixed gear ratio.

[0014] The main pressure source 1 is shared by the oil input circuits of each clutch pressure regulating circuit, and the secondary pressure source 2 is shared by the oil supply circuits of each clutch solenoid valve. The oil pressure of the main pressure source is greater than that of the secondary pressure source.

[0015] Reference Figures 1-3As shown, a high dynamic response pressure regulating oil circuit for a hybrid transmission according to the present invention includes a main pressure source 1, a secondary pressure source 2, four accumulators 3, and four main pressure regulating valves 18. The secondary pressure source 2 is pressure-reduced to approximately 6 bar by a pressure limiting valve, serving as the input oil pressure for the solenoid valves. This pressure is then connected to the C1 clutch control solenoid valve 4, the C2 clutch control solenoid valve 5, the B2 brake control solenoid valve 6, and the B1 brake control solenoid valve 7 via oil circuit b, supplying hydraulic oil. The C1 clutch control solenoid valve 4 and the C2 clutch control solenoid valve 5... The B2 brake control solenoid valve 6 and the B1 brake control solenoid valve 7 can apply hydraulic oil pressure to the working surfaces of the four main pressure regulating valves 18 through oil circuit c. The main pressure source 1 is connected to the four main pressure regulating valves 18 through oil circuit a. The four main pressure regulating valves 18 are connected to the B1 brake 10, B2 brake 11, C2 clutch 12, and C1 clutch 13 through oil circuit d. Under the action of oil circuit c, the main pressure regulating valves 18 connect oil circuit a and oil circuit d, and the hydraulic oil is applied to the corresponding brakes and clutches.

[0016] The C1 clutch control solenoid valve 4, C2 clutch control solenoid valve 5, B2 brake control solenoid valve 6, and B1 brake control solenoid valve 7 are all connected to the accumulator 3 through oil circuit c. The accumulator 3 balances the pressure pulsation and hydraulic shock generated by the output pressure of the solenoid valve, stabilizes the output pressure of the solenoid valve, avoids hydraulic shock phenomenon in the output pressure of the solenoid valve under high dynamic response, which would cause abnormal clutch pressure, and ensures that the clutch end pressure is stable and controllable.

[0017] The main pressure source 1 is supplied with hydraulic oil by an oil pump. The hydraulic oil is adjusted to a stable oil pressure by the main pressure regulating valve 18 and supplied to brakes B1 10 and B2 11, clutches C2 12 and C1 13 for pressure regulation input.

[0018] Each of the main pressure regulating valves 18 includes a limit plug 8, a pressure regulating valve core 9, and a valve body 14. The pressure regulating valve core 9, the limit plug 8, and the spring 15 are all disposed in the central valve cavity of the valve body 14. The limit plug 8 is disposed at one end of the pressure regulating valve core 9 near the solenoid valve, and the spring 15 is disposed at the other end of the pressure regulating valve core 9. The main function of the limit plug 8 is to limit the pressure regulating valve core 9 after it is installed, and to seal the oil pressure. The valve body 14 is provided with oil port c19, oil port a20, and oil port d21 sequentially from one end of the solenoid valve to the other end. Oil port c19 is connected to oil circuit c, oil port a20 is connected to oil circuit a, and oil port d21 is connected to oil circuit d.

[0019] The oil passage c at the output end of the solenoid valve and the actuating end of the pressure regulating valve core 9 are connected by a straight-through oil passage and are arranged adjacent to the solenoid valve, so that the pressure regulating valve core 9 can respond quickly after the solenoid valve receives the control signal.

[0020] The design minimizes the clearance between the pressure regulating valve core 9 and the valve body 14, reducing leakage. The outer diameter of the pressure regulating valve core 9 is designed to be relatively large. The oil inlet and outlet ports (port a20 and port d21) of the valve body 14 are designed with annular groove oil passages f to ensure a large flow rate during the opening of the pressure regulating valve core 9, increasing the flow rate from the inlet to the outlet at the corresponding pressure regulating opening. The clutch pressure oil passage also adopts a straight-through design. The depth and size of the annular groove oil passages f are designed to match the pressure regulating responsiveness requirements.

[0021] The pressure regulating valve core 9 is designed with an operating end face, main shaft diameter, shoulder, and feedback differential pressure design. Its pressure regulating principle is as follows: the output pressure of the solenoid valve acts on the pressure regulating valve core 9 through oil circuit c; the hydraulic oil in oil circuit a is output to oil circuit d through the pressure regulating valve core 9; the oil pressure in oil circuit d acts on the feedback surface of the pressure regulating valve core 9 to form feedback pressure. The feedback pressure and the spring force of spring 15 are balanced with the force exerted on the pressure regulating valve core 9 by oil circuit c, achieving linear pressure control. The oil ports a20 and d21 of the pressure regulating valve core 9 are designed with annular groove oil circuit f to ensure a large flow rate during the opening of the pressure regulating valve core 9, giving the clutch pressure regulation high dynamic response. The pressure is output to the clutch piston through oil circuit d, enabling clutch engagement and torque transmission. The pressure regulating principle of each clutch is the same; the feedback force can be adjusted by adjusting the spring stiffness and surface area according to the clutch control accuracy requirements.

[0022] Each valve body 14 has an oil port e22. The oil ports e22 of the two valve bodies 14 controlling the C1 clutch control solenoid valve 4 and the C2 clutch control solenoid valve 5 share a common oil passage e for oil unloading. The oil ports e22 of the two valve bodies 14 controlling the B2 brake control solenoid valve 6 and the B1 brake control solenoid valve 7 share a common oil passage e for oil unloading.

[0023] Oil port E22 is an oil discharge hole. Oil passage E is connected to the drain hole. It has two main functions: First, it is a necessary leakage oil passage for the linear pressure regulation mechanism. Without this structure, the inlet pressure will be equal to the output pressure instantaneously, making it impossible to guarantee linear pressure change. Second, it allows the clutch pressure oil to be released when the clutch is not in operation.

[0024] The horizontal cross-section of the oil port d21 is U-shaped, and the oil port a20 is located inside the U-shaped opening of the oil port d21.

[0025] An oil pressure equalization groove h is formed on oil port a20, and an oil pressure equalization groove g is formed on oil port e22. The main function of the equalization groove is to prevent sudden pressure changes and poor pressure linearity caused by changes in the position and opening of the pressure regulating valve during the pressure regulation process. The equalization groove design allows for a smooth transition of pressure in the high-flow, high-dynamic-response pressure regulating oil circuit, resulting in higher pressure linearity accuracy during the pressure regulation process and preventing sudden pressure changes. The specific dimensions of the equalization groove are designed to match the corresponding pressure and flow rate of the pressure regulating mechanism.

[0026] Each of the main pressure regulating valves 18 also includes a retaining ring 16. The valve body 14 has a mounting groove 23 communicating with the central valve chamber. The retaining ring 16 is installed in the mounting groove 23, and its elastic force acts on the limiting plug 8. Besides limiting and fixing the limiting plug 8, the retaining ring 16 primarily prevents pressure overshoot caused by the reaction force of the limiting plug 8 after the pressure of the oil circuit c acts on the pressure regulating valve core 9. The retaining ring 16 design effectively reduces pressure anomalies caused by the reaction force on the limiting plug 8 and the pressure regulating valve core 9, thus improving the pressure regulation accuracy. The design of the retaining ring 16 also improves the linearity accuracy of the pressure regulating mechanism. Based on the above design, the pressure regulating valve core can respond quickly under both high and low temperature conditions, achieving a clutch pressure regulating oil circuit with high dynamic response.

[0027] Working principle: The clutch pressure is controlled by controlling the clutch solenoid valve, and the corresponding gear ratios can be formed by combining two of them according to the power flow requirements.

[0028] During mode switching and gear shifting in hybrid vehicles, the actuators must possess excellent dynamic response to ensure good power output and shifting comfort.

[0029] For example, according to a certain power flow, clutch C1 and brake B1 form a parallel first gear, clutch C1 and brake B2 form a parallel second gear, clutch C1 and clutch C2 form a parallel third gear, clutch C2 and brake B2 form a parallel fourth gear, and brake B1 forms a pure electric first gear, and brake B2 forms a pure electric second gear. This high dynamic response pressure regulating oil circuit is also suitable for different gear situations with different power flow combinations. If the vehicle is currently in pure electric first gear mode, according to the control strategy of hybrid vehicles, it needs to switch from pure electric first gear to parallel first gear. This requires quickly engaging the B1 brake. Hydraulic oil flows from secondary pressure source 2 through oil circuit b to the input of the B1 solenoid valve. When the TCU control signal activates the B1 brake solenoid valve 7, hydraulic oil flows from oil circuit b through the solenoid valve to oil circuit c. The oil pressure in oil circuit c acts on the action surface of the pressure regulating valve core 9, causing the pressure regulating valve core to move to the left. Oil circuits a and c are respectively designed with annular groove structures f at their corresponding connection positions with the pressure regulating valve core. Therefore, the main pressure source connects to oil circuit d via oil circuit a through the pressure regulating valve core, resulting in a large hydraulic oil flow. Simultaneously, oil circuit d is designed as a straight-through oil circuit, allowing the oil pressure to quickly fill the B1 brake and establish pressure, achieving the control purpose of a fast-response clutch. The operation of other clutches is similar to that of the B1 brake.

[0030] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A hybrid transmission high dynamic response pressure regulating oil path, characterized by: It includes main pressure source (1), secondary pressure source (2), four accumulators (3), four main pressure regulating valves (18); the secondary pressure source (2) is communicated with C1 clutch control solenoid valve (4), C2 clutch control solenoid valve (5), B2 brake control solenoid valve (6), B1 brake control solenoid valve (7) through oil path b and sends into hydraulic oil, C1 clutch control solenoid valve (4), C2 clutch control solenoid valve (5), B2 brake control solenoid valve (6), B1 brake control solenoid valve (7) can be respectively acted on the action surface of four main pressure regulating valves (18) by the oil pressure of hydraulic oil through oil path c, the main pressure source (1) is communicated with four main pressure regulating valves (18) through oil path a, four main pressure regulating valves (18) are communicated with B1 brake (10), B2 brake (11), C2 clutch (12), C1 clutch (13) through oil path d respectively, main pressure regulating valve (18) is communicated with oil path a and oil path d under the action of oil path c, and hydraulic oil is acted on the corresponding brake and clutch, C1 clutch control solenoid valve (4), C2 clutch control solenoid valve (5), B2 brake control solenoid valve (6), B1 brake control solenoid valve (7) are communicated with accumulator (3) through oil path c, and accumulator (3) balances the pressure pulsation and hydraulic impact generated by solenoid valve output pressure, stabilizes solenoid valve output pressure, and guarantees that clutch end pressure is smooth and controllable.

2. The high dynamic response pressure regulating oil path of a hybrid transmission according to claim 1, characterized by: The main pressure source (1) adopts the form of oil pump to supply hydraulic oil, and the stable oil pressure is adjusted by the main pressure regulating valve (18) to supply B1 brake (10), B2 brake (11), C2 clutch (12) and C1 clutch (13) for pressure regulating input.

3. The high dynamic response pressure regulating oil path of a hybrid transmission according to claim 1, characterized in that: Each main pressure regulating valve (18) includes a limit plug (8), a pressure regulating valve core (9) and a valve body (14); the pressure regulating valve core (9), the limit plug (8) and the spring (15) are arranged in the center valve cavity of the valve body (14), the limit plug (8) is arranged at one end of the pressure regulating valve core (9) close to the solenoid valve, the spring (15) is arranged at the other end of the pressure regulating valve core (9), and the valve body (14) is sequentially provided with an oil port c (19), an oil port a (20) and an oil port d (21) from one end of the solenoid valve to the other end, the oil port c (19) is communicated with the oil path c, the oil port a (20) is communicated with the oil path a, and the oil port d (21) is communicated with the oil path d.

4. The hybrid transmission high dynamic response pressure regulating oil path of claim 3, wherein: Oil port e (22) is formed on each valve body (14), and the oil port e (22) of the two valve bodies (14) of C1 clutch control solenoid valve (4) and C2 clutch control solenoid valve (5) is shared with an oil path e for oil discharge, and the oil port e (22) of the two valve bodies (14) of B2 brake control solenoid valve (6) and B1 brake control solenoid valve (7) is shared with an oil path e for oil discharge.

5. The hybrid transmission high dynamic response pressure regulating oil path of claim 4, wherein: The valve body (14) is provided with a ring groove structure f at the part corresponding to the oil port a (20) and the oil port d (21).

6. The hybrid transmission high dynamic response pressure regulating oil path of claim 5, wherein: Each of the main regulating valve (18) further comprises a snap spring (16), the valve body (14) is provided with an installation slot (23) communicated with the center valve cavity, the snap spring (16) is installed in the installation slot (23), and the elastic force of the snap spring (16) acts on the limiting plug (8).

7. The hybrid transmission high dynamic response pressure regulating oil path of claim 6, wherein: The horizontal section of the oil port d (21) is U-shaped, and the oil port a (20) is arranged in the U-shaped oil port d (21).

8. The hybrid transmission high dynamic response pressure regulating oil path of claim 7, wherein: An oil hole flat pressing groove h is arranged on the oil port a (20), and an oil hole flat pressing groove g is arranged on the oil port e (22).

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