Hydraulic control system

Abstract

The invention belongs to the technical field of transmission, and discloses a hydraulic control system, which includes a low-pressure lubrication circuit and a high-pressure lubrication oil circuit, wherein the low-pressure lubrication oil circuit includes an oil tank, an electronic pump, a throttle group, a flow distribution slide valve, a generator cooling slide valve and a low-pressure oil circuit; the high-pressure lubrication circuit includes an oil tank, a double-acting vane pump, a vane pump state switching slide valve, a vane pump check valve, a main oil pressure regulating slide valve and a clutch pressure control solenoid valve, the oil tank, the double-acting vane pump, and the vane pump state switching slide valve are connected in series in sequence, and the oil passes through the first output port of the vane pump state switching slide valve and the vane pump check valve in sequence and is connected to the low-pressure oil circuit, the second output port of the vane pump state switching slide valve is connected in parallel with the main oil pressure regulating slide valve and the clutch pressure control solenoid valve, and the oil overflowing from the main oil pressure regulating slide valve passes through the vane pump check valve and flows to the low-pressure oil circuit. The total flow requirement can be reduced, the volume of the electric pump and the mechanical pump can be reduced, and the layout is convenient.

Description

Technical Field

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

[0002] At present, under the background of energy and environmental crisis, all automobile enterprises are vigorously promoting the research and development of new energy vehicles. Traditional fuel vehicles are highly dependent on energy, and have reached the limit of efficiency through long-term technological progress. It is difficult to further reduce fuel consumption and energy consumption through technological innovation; electric vehicles have the advantages of zero emissions and low noise, but the charging facilities are not perfect, the low-temperature range is reduced, and the high price is difficult to solve in the short term. At low speeds, the engine of hybrid models generates electricity in the best efficiency zone and then supplies the motor to drive the vehicle. At high speeds, the engine is directly driven, so that the engine always works in the high efficiency zone. Therefore, hybrid vehicles have low fuel consumption, low noise, and the cost is the same as that of fuel vehicles. Therefore, the emergence of hybrid vehicles (HEV) has become the best solution before the complete transition to pure electric.

[0003] At present, common hybrid configurations on the market include Toyota's power split THS, series-parallel ones such as Honda i-MMD, BYD DM-i, and series-connected ones such as Nissan E-Power. From the perspective of balancing power and economy, the series-parallel solution has become the mainstream solution in China.

[0004] In existing hybrid vehicle models, the oil source system of the hydraulic control device of the multi-speed hybrid transmission generally adopts two schemes. Scheme I adopts two mechanical pumps, a high-pressure pump driven by the engine, and a low-pressure pump driven by the drive motor, which are coupled together to complete the required functions; Scheme II adopts two separate electric pumps or an electric double oil pump, one is a low-pressure pump, which is mainly used for cooling and lubrication, and the other is a high-pressure pump with an accumulator, which is executed on demand and has a higher overall efficiency.

[0005] However, in Scheme I, the mechanical pump must meet the requirements of all working conditions, and usually has a relatively large displacement, because its speed depends on the engine speed and the drive motor speed and cannot be actively adjusted. In addition, the high-pressure pump only requires a large flow rate when shifting gears, and only a very small flow rate is needed to maintain pressure under other working conditions. Therefore, there is energy waste in most working conditions.

[0006] Solution II uses two electric pumps, which is very expensive, occupies a large space, and has high requirements for valve body cleanliness and sealing. In addition, both solutions simply distribute the cooling and lubrication of each component through a fixed throttle hole or a flow distribution valve, and cannot accurately distribute the cooling flow according to the hybrid working condition. Summary of the invention

[0007] The object of the present invention is to provide a hydraulic control system which reduces the total flow requirement and achieves energy saving, while reducing the volume of electric pumps and mechanical pumps for easy layout.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] A hydraulic control system, comprising:

[0010] Low-pressure lubrication circuit: an oil tank, an electronic pump, a throttle group, a flow distribution slide valve, a generator cooling slide valve and a low-pressure oil circuit, wherein the oil tank, the electronic pump and the low-pressure oil circuit are connected in series in sequence, and the throttle group, the flow distribution slide valve and the generator cooling slide valve are connected in parallel to the low-pressure oil circuit;

[0011] High-pressure lubrication circuit: the oil tank, the double-acting vane pump, the vane pump state switching slide valve, the vane pump check valve, the main oil pressure regulating slide valve and the clutch pressure control solenoid valve. The oil tank, the double-acting vane pump and the vane pump state switching slide valve are connected in series in sequence. The oil passes through the first output port of the vane pump state switching slide valve and the vane pump check valve in sequence and is connected to the low-pressure oil circuit. The second output port of the vane pump state switching slide valve is connected in parallel with the main oil pressure regulating slide valve and the clutch pressure control solenoid valve. The oil overflowing from the main oil pressure regulating slide valve passes through the vane pump check valve and flows to the low-pressure oil circuit.

[0012] Preferably, an electronic pump check valve, a cooler and a pressure filter are provided in sequence between the electronic pump and the low-pressure oil circuit, and the oil is connected between the electronic pump check valve and the cooler after passing through the vane pump check valve.

[0013] Preferably, two ends of the valve core of the generator cooling slide valve are respectively connected to the front and rear oil circuits of the main oil pressure regulating slide valve.

[0014] Preferably, it further includes a pilot solenoid valve, which coordinately controls the positions of the vane pump state switching slide valve and the flow distribution slide valve.

[0015] Preferably, the pilot solenoid valve is communicated with the second output port.

[0016] Preferably, it also includes a main oil pressure regulating pilot solenoid valve, and the main oil pressure regulating pilot solenoid valve, the main oil pressure regulating slide valve, the pilot solenoid valve and the clutch pressure control solenoid valve are connected in parallel to the second output port.

[0017] Preferably, the throttle hole group is connected to the shaft gear, bearing, engine and clutch.

[0018] Preferably, the flow distribution slide valve is connected to the drive motor and the clutch.

[0019] The beneficial effects of the present invention are as follows: an electronic pump and a double-acting vane pump are used as hydraulic power sources. In EV mode, the electric pump provides cooling and lubrication flow. In series and parallel modes, the electronic pump and the double-acting vane pump jointly provide cooling and lubrication flow as well as high-pressure flow for clutch torque transmission or shifting. The two output ports of the double-acting vane pump are connected to a vane pump state switching slide valve. By switching the slide valve position, the two output ports can be merged and separated. The oil pump displacement of the high-pressure oil circuit is adjusted according to the working conditions, thereby realizing high-pressure and large flow for shifting, and high-pressure and small flow for pressure maintenance during driving, thereby achieving energy saving. The flow of the low-pressure oil circuit is adjusted by two slide valves, thereby achieving accurate flow distribution according to different working conditions and cooling on demand, thereby reducing the total flow demand and achieving energy saving. At the same time, the volume of the electric pump and the mechanical pump can be reduced, which is convenient for layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a hydraulic control system provided in this embodiment;

[0021] Figure 2 is a schematic diagram of the hydraulic control system provided in this embodiment in pure electric driving mode;

[0022] Figure 3 is a schematic diagram of the hydraulic control system provided in the embodiment in series mode;

[0023] Figure 4 is a schematic diagram of the hydraulic control system provided in the present embodiment in direct drive mode;

[0024] Figure 5 It is a schematic diagram of the hydraulic control system provided in the present embodiment in the shifting mode. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0026] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0028] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0029] The present invention provides a hydraulic control system, such as Figure 1 As shown, the system includes a low-pressure lubrication circuit and a high-pressure lubrication circuit.

[0030] The low-pressure lubrication circuit includes an oil tank 1, a first suction filter 2A, an electronic pump 3, a vane pump check valve 6, an electronic pump check valve 7, a cooler 8, a pressure filter 9, a throttle hole group 10, a flow distribution slide valve 11, and a generator cooling slide valve 12.

[0031] The high-pressure lubrication circuit includes an oil tank 1, a second suction filter 2B, a double-acting vane pump 4 (driven by the engine), a vane pump state switching slide valve 5, a main oil pressure regulating pilot solenoid valve 21, a main oil pressure regulating slide valve 22, a high-pressure oil circuit safety valve 23, a pilot solenoid valve 24, a first clutch pressure control solenoid valve 25 and a second clutch pressure control solenoid valve 26.

[0032] In the low-pressure lubrication circuit, after the electronic pump 3 is running, the oil in the oil tank 1 is extracted by the electronic pump 3 through the first suction filter 2A, and then passes through the check valve 7, the cooler 8, the filter press 9 to the low-pressure oil circuit 13, and then is divided into three routes: the first route is basically distributed to the shaft gear, bearings, power motor P1 and clutch C1 and clutch C2 through the throttle hole group 10; the second route cools the drive motor P3, clutch C1 and clutch C2 by adjusting the position of the flow distribution slide valve 11; the third route cools the power motor P1 by adjusting the generator cooling slide valve 12.

[0033] In the high-pressure lubrication circuit, if the engine is working and in the series power generation mode, the two output ports of the double-acting vane pump 4 both output low-pressure oil, and the vane pump state switching slide valve 5 is in the initial position. The oil discharged from the first output port 16 of the vane pump is merged into the low-pressure oil circuit 13 through the vane pump state switching slide valve 5 and the vane pump check valve 6, and the oil discharged from the second output port 17 is also merged into the low-pressure oil circuit 13 through the vane pump state switching slide valve 5, the main oil pressure regulating slide valve 22, and the vane pump check valve 6. At this time, according to the cooling flow demand of the hybrid system, the electronic pump 3 supplements the insufficient flow. If the engine is running and in parallel direct drive mode, the second output port 17 of the double-acting vane pump 4 outputs high-pressure oil, and the first output port 16 outputs according to the working condition: specifically, when the working condition 1 is normal driving (clutch is pressed), the pressure of the pilot solenoid valve 24 is adjusted so that the vane pump state switching slide valve 5 is in the initial position, and the flow distribution slide valve 11 is in the second working position (from left to right). The first output port 16 outputs low-pressure oil and merges with the oil overflowing through the main oil pressure regulating slide valve 22, and then flows into the low-pressure oil circuit 13 through the vane pump check valve 6 to cool and lubricate various components. Only the second output port 17 High-pressure oil can meet the system's requirements for high-pressure flow; when the power is downshifted or upshifted in working condition 2, the pressure of the pilot solenoid valve 24 is adjusted so that the vane pump state switching slide valve 5 is in the working position (right position), and the flow distribution slide valve 11 is in the third or fourth working position (position three or four depends on whether the power is downshifted or upshifted). After the first output port 16 and the second output port 17 are merged, both output high-pressure oil to meet the large flow demand during gear shifting. The low-pressure oil overflowing from the main oil pressure regulating slide valve 22 flows into the low-pressure oil circuit 13 through the vane pump check valve 6 to cool and lubricate various components, and the electronic pump 3 supplements the insufficient flow. Therefore, the first pressure at which the vane pump state switching slide valve 5 switches from the initial position to the working position is set to be the same as the second pressure at which the flow distribution slide valve 11 switches to the third working position. That is, when the power is downshifted or upshifted, a large flow of high-pressure oil is required, and at the same time, the clutch C1 or the clutch C2 also requires a large cooling flow. At this time, the coordinated control of the flow distribution slide valve 11 and the vane pump state switching slide valve 5 can be achieved by adjusting the pilot solenoid valve 24 to meet the high and low pressure flow requirements during gear shifting.

[0034] The flow distribution of the whole system is realized by the throttle group 10, the flow distribution slide valve 11, the generator cooling slide valve 12 and the pilot solenoid valve 24. The throttle group 10 distributes the flow to the bearing, the shaft gear, the engine P3, the clutch C1 and the clutch C2 on a fixed basis, and then the flow distribution slide valve 11 is switched between four states by adjusting the pilot solenoid valve 24, so that the flow distribution of the engine P3, the clutch C1 and the clutch C2 can be adjusted according to the working conditions.

[0035] The two ends of the valve core of the generator cooling slide valve 12 are respectively connected to the front and rear oil circuits of the main oil pressure regulating slide valve 22. When the hybrid transmission is in series mode, the two output ports of the double-acting vane pump 4 both output low-pressure oil, so the oil pressure at both ends of the valve core is the same. The area on the left side of the valve core is specially set to be larger than the area on the right side. At this time, the valve core switches to the working position, and the oil in the low-pressure oil circuit 13 is divided into one path to cool the power motor P1; when the hybrid transmission is in parallel mode, the double-acting vane pump 4 will output high-pressure oil, and the oil pressure on the right side of the valve core is much greater than that on the left side. The valve core remains in the initial position and does not distribute cooling oil to the power motor P1. When in pure electric driving, the engine is turned off, the double-acting vane pump 4 does not run, and there is no oil pressure at both ends of the valve core of the generator cooling slide valve 12. The valve core of the generator cooling slide valve 12 remains in the initial position under the action of the spring, and does not distribute cooling oil to the power motor P1. Through this distribution system, accurate flow distribution and on-demand energy supply can be performed according to the working conditions of the hybrid transmission to achieve efficient cooling.

[0036] Condition 1: Pure electric driving

[0037] Line relationship Figure 2 As shown, the power motor P1 drives the vehicle, and the cooling lubricating oil is provided by the electronic pump 3. The shaft gears, bearings, transmission C1, and transmission C2 only provide basic cooling flow. Most of the flow is provided to the power motor P1 to cool the drive motor P1, and the electronic pump 3 supplies on demand.

[0038] Condition 2: Series mode

[0039] Line relationship Figure 3 As shown, the engine drives the generator P3 to generate electricity, and the drive motor P1 drives the vehicle to travel. At this time, the cooling lubricating oil is mainly provided by the double-acting vane pump 4 with high efficiency, and the insufficient part is supplemented by the electronic pump 3. The shaft gears, bearings, transmission C1 and transmission C2 only provide basic cooling flow, and most of the other flow is provided to the power motor P1 and the engine P3 for cooling.

[0040] Condition 3: Direct drive mode

[0041] Line relationship Figure 4 As shown, the engine directly drives the vehicle to travel, and the excess power is generated by the drive motor P1. At this time, the cooling lubricating oil is mainly provided by the double-acting vane pump 4, which is highly efficient. The insufficient part is supplemented by the electronic pump 3. The shaft gears, bearings, and drive motor P1 only provide basic cooling flow. The engine P3 does not provide cooling oil, and most of the other flow is provided to the transmission C1 and transmission C2 for cooling. High-pressure oil is provided by the second output port 17 of the double-acting vane pump 4, which only maintains the lowest high-pressure flow of the system.

[0042] Condition 4: Gear Shift Mode

[0043] Line relationship Figure 5 As shown, the engine directly drives the vehicle to travel, and the excess power is generated by the drive motor P1. At this time, the cooling lubricating oil is mainly provided by the double-acting vane pump 4, which is highly efficient. The insufficient part is supplemented by the electronic pump 3. The shaft gears, bearings, and drive motor P1 only provide basic cooling flow, and the engine P3 does not provide cooling oil. When power downshifting and upshifting are required, the transmission C1 or transmission C2 needs a larger cooling flow during the shifting process. The flow distribution slide valve 11 is adjusted to position three or four, and most of the flow is provided to the transmission C1 or transmission C2 for cooling. High-pressure oil is provided by the first output port 16 and the second output port 17 of the double-acting vane pump 4, and a large flow of high-pressure oil is output to meet the shifting requirements.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A hydraulic control system, characterized in that: include: A low-pressure lubrication circuit: an oil tank (1), an electronic pump (3), a throttle group (10), a flow distribution slide valve (11), a generator cooling slide valve (12) and a low-pressure oil circuit (13), wherein the oil tank (1), the electronic pump (3) and the low-pressure oil circuit (13) are sequentially connected in series, and the throttle group (10), the flow distribution slide valve (11) and the generator cooling slide valve (12) are connected in parallel to the low-pressure oil circuit (13); A high-pressure lubrication circuit: the oil tank (1), the double-acting vane pump (4), the vane pump state switching slide valve (5), the vane pump check valve (6), the main oil pressure regulating slide valve (22) and the clutch pressure control solenoid valve. The oil tank (1), the double-acting vane pump (4) and the vane pump state switching slide valve (5) are sequentially connected in series. The double-acting vane pump (4) is driven by an engine. The first output port (16) and the second output port (17) of the double-acting vane pump (4) are respectively connected to the vane pump state switching slide valve (5). The oil output from the first output port (16) passes through the vane pump state switching slide valve (5) and the vane pump check valve (6) in sequence and is then connected to the low-pressure oil circuit (13). The second output port (17) of the double-acting vane pump (4) is connected in parallel to the main oil pressure regulating slide valve (22) and the clutch pressure control solenoid valve. The oil overflowing from the main oil pressure regulating slide valve (22) passes through the vane pump check valve (6) and then flows to the low-pressure oil circuit (13). When the double-acting vane pump (4) is in operation, the first output port (16) and the second output port (17) of the double-acting vane pump (4) can output high-pressure oil and high-pressure oil, low-pressure oil and low-pressure oil, or low-pressure oil and high-pressure oil according to working conditions.

2. The hydraulic control system according to claim 1, characterized in that: An electronic pump check valve (7), a cooler (8) and a pressure filter (9) are provided in sequence between the electronic pump (3) and the low-pressure oil circuit (13); the oil passes through the vane pump check valve (6) and is connected to between the electronic pump check valve (7) and the cooler (8).

3. The hydraulic control system according to claim 1, characterized in that: Both ends of the valve core of the generator cooling slide valve (12) are respectively connected to the front and rear oil passages of the main oil pressure regulating slide valve (22).

4. The hydraulic control system according to claim 1, characterized in that: It also includes a pilot solenoid valve (24), which coordinates the positions of the vane pump state switching slide valve (5) and the flow distribution slide valve (11).

5. The hydraulic control system according to claim 4, characterized in that: The pilot solenoid valve (24) is in communication with the second output port (17).

6. The hydraulic control system according to claim 5, characterized in that: It also comprises a main oil pressure regulating pilot solenoid valve (21), wherein the main oil pressure regulating pilot solenoid valve (21), the main oil pressure regulating slide valve (22), the pilot solenoid valve (24) and the clutch pressure control solenoid valve are connected in parallel to the second output port (17).

7. The hydraulic control system according to claim 1, characterized in that: The throttle hole group (10) is connected to the shaft gear, bearing, engine and clutch.

8. The hydraulic control system according to claim 7, characterized in that: The flow distribution slide valve (11) is connected to the drive motor and the clutch.

Images