Hydraulic control system and method for wet clutch

Abstract

According to the wet clutch hydraulic control system and method, a variable pump assembly is additionally arranged in the system, the variable pump assembly can adjust the supply flow of a hydraulic system, the output end of the variable pump assembly is divided into multiple paths, meanwhile, an electromagnetic reversing valve is arranged in front of a lubricating cavity of a wet clutch set in a matched mode, and cooling and lubricating requirements under different working conditions are met. The electromagnetic reversing valve is selectively opened or closed, the output flow of the variable pump assembly is adjusted, the cooling and lubricating flow needed when the wet clutch is used is controlled, it can be guaranteed that the wet clutch cannot lose efficacy due to overheating, and the service life of the wet clutch is prolonged. And the cooling and lubricating flow can be reduced or blocked when the wet clutch does not need excessive cooling and lubricating flow, so that the energy consumption of a transmission system is reduced, and the overall efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of wet clutch technology and relates to a wet clutch hydraulic control system and method. Background Technology

[0002] Wet clutches are common shifting actuators in the transmission systems of various road vehicles, construction machinery, agricultural machinery, and special equipment (used in hydraulic automatic transmissions, dual-clutch automatic transmissions, power shift transmissions, power reversing modules, and various hybrid automatic transmissions). They are clutches where the friction pairs operate in lubricating oil. The transmission system combines multiple wet clutches and gears, controlling the engagement and disengagement of the wet clutch friction pairs to achieve power transmission, switching, or interruption, obtaining a predetermined power transmission route, and fulfilling the requirements of uninterrupted power shifting, neutral, or parking in equipment or vehicles.

[0003] The friction pairs of wet clutches generate a lot of heat during engagement, especially clutches with prolonged slippage time, such as wet clutches used for starting or reversing in the transmission systems of road vehicles, construction machinery, and agricultural machinery. The heat generated needs to be carried away by cooling lubricating oil in time; otherwise, the accumulation of heat will cause the friction pairs to fail, resulting in serious consequences.

[0004] In existing products using wet clutches, cooling and lubrication are basically achieved by a fixed cooling and lubrication flow rate. Although this technology can remove heat from the wet clutch, the heat generated by the frequency of use of the wet clutch cannot be accurately identified. Therefore, there may be problems such as excessively high temperature due to frequent switching of the wet clutch (i.e., the generated heat cannot be removed in time), or waste of cooling and lubricating oil due to the wet clutch not being switched for a long time (i.e., no heat is generated when not switched for a long time). The former is more likely to occur when the hydraulic power supply flow rate is low (low oil pump speed, low total supply flow rate), while the latter is more likely to occur when the hydraulic power supply flow rate is high (high oil pump speed, high total supply flow rate).

[0005] Some technical solutions aim to reduce energy consumption by adding a reversing valve or lubrication switching structure to the cooling and lubrication oil circuit. This allows the clutch lubrication oil circuit to open only during operation, providing a larger flow to the clutch and making it more effectively cooled and lubricated. However, these technical solutions still have the potential to lead to clutch failure or waste of cooling and lubricating oil due to the inaccurate identification of the heat generated by the frequent use of the wet clutch.

[0006] In recent years, with the improvement of control technology, a new approach has emerged that monitors the balance between heat generation and dissipation during the use of wet clutches to avoid clutch failure caused by heat not being dissipated in time. However, this method is relatively complex, requiring extensive calibration tests in the system where the wet clutch is used to obtain key data for control requirements. Furthermore, it cannot solve the problem of wasted cooling and lubricating oil caused by the wet clutch not being switched for extended periods. Summary of the Invention

[0007] The purpose of this invention is to solve the problem in the prior art that wet clutches cannot adjust and control their cooling and lubrication flow according to different working conditions during use, resulting in clutch failure or waste of cooling and lubricating oil, and to provide a hydraulic control system and method for wet clutches.

[0008] To achieve the above objectives, the present invention employs the following technical solution:

[0009] A wet clutch hydraulic control system includes an oil sump, the oil sump being connected to a variable displacement pump assembly, the variable displacement pump assembly being connected to a prime mover, and the variable displacement pump assembly being able to adjust the hydraulic system supply flow.

[0010] The output of the variable pump assembly includes three paths: the first path is connected to the inlet of the main pressure regulating valve and the oil cooler in sequence; the second path is connected to the inlet of the second electromagnetic proportional pressure regulating valve; and the third path is connected to the main oil circuit interface.

[0011] The oil cooler has two outlets: one is connected to the lubrication chamber of the solenoid directional valve and the wet clutch assembly in sequence, and the other is connected to other lubrication oil circuit interfaces.

[0012] The second electromagnetic proportional pressure regulating valve is connected to the piston chamber of the wet clutch assembly.

[0013] A further improvement of the present invention is that:

[0014] The variable pump assembly includes a connected variable pump and a first electromagnetic proportional pressure regulating valve, and the outlet of the variable pump and the outlet of the first electromagnetic proportional pressure regulating valve are both connected to a piston cylinder.

[0015] A first filter is provided between the variable pump assembly and the oil tank;

[0016] The output end of the variable pump assembly is connected to a second filter, which is connected to the inlet of the main pressure regulating valve, the inlet of the second electromagnetic proportional pressure regulating valve, and the main oil circuit interface.

[0017] The inlet of the variable pump is connected to the outlet of the first filter, the outlet of the variable pump is connected to the inlet of the second filter, and the outlet of the second filter is connected to the inlet of the first electromagnetic proportional pressure regulating valve.

[0018] A wet clutch lubrication circuit is provided between the electromagnetic reversing valve and the wet clutch assembly.

[0019] It also includes a temperature sensor, which is located at the output end of the oil cooler.

[0020] A hydraulic control method for a wet clutch includes the following steps:

[0021] When the wet clutch has no cooling or lubrication requirement, the solenoid directional valve is closed, and the hydraulic oil enters the lubrication oil interface and the main oil interface respectively after passing through the variable pump assembly.

[0022] When the wet clutch requires cooling and lubrication, the solenoid directional valve is opened to increase the displacement of the variable pump assembly. The hydraulic oil then enters the wet clutch assembly, the lubrication line interface, and the main oil line interface after passing through the variable pump assembly.

[0023] When the wet clutch generates heat, the parameters of the cooling lubricating oil required by the wet clutch under different operating conditions are calibrated. When the wet clutch generates heat, the parameters of the cooling lubricating oil required by the wet clutch are determined according to the current operating condition information, and the displacement of the variable pump assembly and the opening of the solenoid directional valve are adjusted.

[0024] When the wet clutch has no cooling or lubrication requirements, the following steps are included:

[0025] When the wet clutch is disengaged in the transmission system, the second electromagnetic proportional pressure regulating valve and the electromagnetic reversing valve are closed. The oil delivered by the variable pump assembly is divided into two paths: one path is delivered to other lubrication circuit interfaces after passing through the main pressure regulating valve and the oil cooler, and the other path is delivered to the main oil circuit interface.

[0026] When the wet clutch requires cooling and lubrication, the following steps are included:

[0027] When the wet clutch changes from disengaged to engaged in the transmission system, the second electromagnetic proportional pressure regulating valve and the electromagnetic directional valve are activated, increasing the displacement of the variable pump assembly. The oil delivered by the variable pump assembly is divided into three paths:

[0028] The first path splits into two sub-paths after passing through the main pressure regulating valve and oil cooler. The first sub-path enters other lubricating oil circuit interfaces, and the second path enters the wet clutch assembly after passing through the solenoid reversing valve.

[0029] The second path enters the wet clutch assembly after passing through the second electromagnetic proportional pressure regulating valve.

[0030] The third route delivers oil to the main oil line interface;

[0031] When the wet clutch remains engaged in the transmission system, close the solenoid directional valve to reduce the displacement of the variable pump assembly.

[0032] The current operating condition information includes the speed, operating time, and torque of the wet clutch.

[0033] The parameters of the cooling lubricating oil include the required flow rate, temperature, and cooling time of the cooling lubricating oil for the wet clutch.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This invention discloses a hydraulic control system and method for a wet clutch. A variable displacement pump assembly is added to the system, which can adjust the hydraulic system's supply flow. The output of the variable displacement pump assembly is divided into multiple paths. Simultaneously, an electromagnetic directional valve is installed before the lubrication chamber of the wet clutch assembly. Based on the cooling and lubrication requirements under different operating conditions, the electromagnetic directional valve is selectively opened or closed, and the output flow of the variable displacement pump assembly is adjusted. This controls the cooling and lubrication flow required by the wet clutch during use, ensuring that the wet clutch does not fail due to overheating, and reducing or blocking the cooling and lubrication flow when the wet clutch does not require excessive cooling and lubrication, thereby reducing transmission system energy consumption and improving overall machine efficiency. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the hydraulic system of the present invention;

[0038] Figure 2 This is a schematic diagram of the variable pump assembly in the hydraulic system of the present invention;

[0039] Figure 3 This is a flowchart of the control method of the present invention.

[0040] Wherein: 1-oil sump; 2-first filter; 3-prime mover; 4-variable pump assembly; 5-second filter; 6-main pressure regulating valve; 7-second electromagnetic proportional pressure regulating valve; 8-oil cooler; 9-temperature sensor; 10-electromagnetic directional valve; 11-wet clutch lubrication circuit; 12-wet clutch assembly; 13-main oil circuit interface; 14-other lubrication circuit interfaces; 4a-variable pump; 4b-first electromagnetic proportional pressure regulating valve; 4c-piston cylinder. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0045] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0046] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0047] The present invention will now be described in further detail with reference to the accompanying drawings:

[0048] See Figures 1 to 3 This invention discloses a hydraulic control system and method for a wet clutch, which can regulate the cooling and lubrication flow. This system can ensure that the wet clutch will not fail due to overheating, and can also reduce or block the cooling and lubrication flow when the wet clutch does not require too much cooling and lubrication flow, thereby reducing energy consumption.

[0049] Example 1

[0050] See Figures 1 to 2 This embodiment discloses a hydraulic control system for a wet clutch, including an oil sump 1. The oil sump 1 is connected to a variable displacement pump assembly 4, which is connected to a prime mover 3. The variable displacement pump assembly 4 can adjust the hydraulic system supply flow. The output end of the variable displacement pump assembly 4 includes three paths: the first path is connected in sequence to the inlet of the main pressure regulating valve 6 and the oil cooler 8; the second path is connected to the inlet of the second electromagnetic proportional pressure regulating valve 7; and the third path is connected to the main oil circuit interface 13. The outlet of the oil cooler 8 is divided into two paths: one path is connected in sequence to the lubrication chamber of the electromagnetic reversing valve 10 and the wet clutch assembly 12; and the other path is connected to other lubrication oil circuit interfaces 14. The outlet of the second electromagnetic proportional pressure regulating valve 7 is connected to the piston chamber of the wet clutch assembly 12.

[0051] Furthermore, in this embodiment, a first filter 2 and a second filter 5 are also included. The oil tank 1 is connected to the inlet of the first filter 2. The oil in the oil tank 1 is drawn into the first filter 2 for the first filtration and then flows to the inlet of the variable pump assembly 4. The oil output from the variable pump assembly 4 flows to the inlet of the second filter 5 for the second filtration. The filtered oil is connected to the inlet of the main pressure regulating valve 6 and the inlet of the second electromagnetic proportional pressure regulating valve 7.

[0052] Furthermore, in this embodiment, the outlet of the main pressure regulating valve 6 is connected to the inlet of the oil cooler 8, which cools the oil after it passes through the main pressure regulating valve 6. The oil passing through the oil cooler 8 is then directed to the inlet of the solenoid directional valve 10, and the outlet of the solenoid directional valve 10 is connected to the wet clutch lubrication circuit 11.

[0053] Furthermore, in this embodiment, the prime mover 3 drives the variable pump assembly 4, wherein the variable pump assembly 4 includes a variable pump 4a, a first electromagnetic proportional pressure regulating valve 4b, and a piston cylinder 4c, specifically:

[0054] The inlet of variable pump 4a is connected to the outlet of the first filter 2, and its outlet is connected to the inlet of the second filter 5.

[0055] The inlet of the first electromagnetic proportional pressure regulating valve 4b is connected to the outlet of the second filter 5, and is connected in parallel with the inlets of the main pressure regulating valve 6 and the second electromagnetic proportional pressure regulating valve 7.

[0056] The two hydraulic control ends of piston cylinder 4c are respectively connected to the outlet of the first electromagnetic proportional pressure regulating valve 4b and the outlet of variable pump 4a.

[0057] The variable pump 4a, the first electromagnetic proportional pressure regulating valve 4b, and the piston cylinder 4c can be replaced with other types of components with flow control functions.

[0058] Furthermore, in this embodiment, the main oil circuit interface 13 is simultaneously connected in parallel to the inlet of the main pressure regulating valve 6, the inlet of the second electromagnetic proportional pressure regulating valve 7, and the inlet of the first electromagnetic proportional pressure regulating valve 4b.

[0059] Furthermore, in this embodiment, a temperature sensor 9 is also included. The temperature sensor 9 is disposed at the output end of the oil cooler 8. The temperature sensor 9 and other lubricating oil circuit interfaces 14 are connected in parallel to the inlet of the solenoid reversing valve 10.

[0060] Furthermore, in this embodiment, the wet clutch assembly 12 is not limited to having one or more piston chamber oil filling holes and lubrication oil passage holes.

[0061] Furthermore, in this embodiment, the main oil circuit interface 13 and other lubrication oil circuit interfaces 14 can be connected and extended to other components, not limited to multiple clutches and their lubrication oil circuits.

[0062] Example 2

[0063] See Figure 3 This embodiment also discloses a hydraulic control method for a wet clutch. The hydraulic control system for a wet clutch disclosed in this embodiment is applied to all transmission systems with wet clutches. During operation, it includes:

[0064] Oil tank 1 provides for storing oil;

[0065] Furthermore, the first filter 2 performs preliminary filtration of the oil in the oil tank 1 and supplies it to the variable pump 4a, while the prime mover 3 provides the mechanical energy source for the variable pump 4a;

[0066] Furthermore, the variable pump 4a is driven by the prime mover 3 and outputs hydraulic oil. The second filter 5 performs a second filtration on the oil output by the variable pump 4a to ensure that the cleanliness of the oil meets the requirements of each hydraulic control component.

[0067] Furthermore, the main pressure regulating valve 6 regulates the inlet pressure to a relatively stable state, thereby providing a stable pressure to the first electromagnetic proportional pressure regulating valve 4b and the second electromagnetic proportional pressure regulating valve 7.

[0068] Furthermore, the first electromagnetic proportional pressure regulating valve 4b adjusts the outlet pressure, which, together with the oil pump outlet feedback pressure, determines the action position of the piston cylinder 4c, thereby adjusting the displacement of the variable pump 4a.

[0069] Furthermore, the second electromagnetic proportional pressure regulating valve 7 controls the pressure leading to the clutch piston chamber, thereby controlling the clutch engagement process;

[0070] Furthermore, the oil passing through the main pressure regulating valve 6 is cooled by the oil cooler 8, and the cooled oil goes to the cooling lubrication circuit.

[0071] Furthermore, the electromagnetic directional valve 10 controls whether the cooling and lubricating oil circuit leads to the wet clutch;

[0072] Furthermore, temperature sensor 9 measures the temperature of the cooled oil to help determine the operating requirements of the first electromagnetic proportional pressure regulating valve 4b and the electromagnetic reversing valve 10.

[0073] Furthermore, the main oil circuit interface 13 and other lubrication oil circuit interfaces 14 provide hydraulic power and cooling lubrication flow to other hydraulic components besides the clutch.

[0074] At work:

[0075] When the wet clutch has no cooling and lubrication requirements, the solenoid directional valve 10 is closed, and the hydraulic oil enters the lubrication oil interface 14 and the main oil interface 13 respectively after passing through the variable pump assembly 4.

[0076] When the wet clutch requires cooling and lubrication, the solenoid directional valve 10 is opened to increase the displacement of the variable pump assembly 4. The hydraulic oil enters the wet clutch assembly 12, the lubrication oil interface 14 and the main oil interface 13 after passing through the variable pump assembly 4.

[0077] The parameters of the cooling lubricating oil required by the wet clutch under different operating conditions are calibrated. When the wet clutch generates heat, the parameters of the cooling lubricating oil required by the wet clutch are determined according to the current operating condition information, and the displacement of the variable pump assembly 4 and the opening of the solenoid directional valve 10 are adjusted.

[0078] Based on the above method, this embodiment specifically discloses four states, including the following steps:

[0079] When the wet clutch is in a disengaged state in the transmission system for an extended period of time:

[0080] When the second electromagnetic proportional pressure regulating valve 7 and the electromagnetic reversing valve 10 are closed, the prime mover 3 has a certain speed. The variable pump assembly 4 outputs oil to the main pressure regulating valve 6. The oil passing through the main pressure regulating valve 6 enters the oil cooler 8 and is finally supplied to other lubrication circuit interfaces 14. At this time, the speed of the prime mover 3 and the displacement of the variable pump assembly 4 jointly determine the amount of oil output, which is sufficient to meet the needs of other lubrication circuits.

[0081] When a wet clutch changes from disengaged to engaged in the transmission system:

[0082] When the second electromagnetic proportional pressure regulating valve 7 and the electromagnetic directional valve 10 are opened, the wet clutch engages. Since the prime mover 3 may provide kinetic energy to other components, its speed cannot change rapidly or the change is limited. At this time, the first electromagnetic proportional pressure regulating valve 4b needs to be energized, causing the piston cylinder 4c to actuate. This increases the displacement of the variable pump 4a, thereby increasing the oil output flow rate and providing more cooling and lubricating oil to the wet clutch lubrication circuit 11 and other lubrication circuit interfaces 14 for cooling and lubrication. Conversely, when the prime mover 3 speed increases during clutch engagement, the current of the first electromagnetic proportional pressure regulating valve 4b can be adjusted to reduce the displacement of the variable pump 4a, preventing excessive oil output flow.

[0083] When a wet clutch is in an engaged state in the transmission system for an extended period of time:

[0084] After a certain period of cooling and lubrication, the wet clutch assembly 12 no longer requires cooling and lubrication flow. At this time, the electromagnetic reversing valve 10 is closed, the second electromagnetic proportional pressure regulating valve 7 is in the open state, and the first electromagnetic proportional pressure regulating valve 4b is adjusted so that under the combined action of the prime mover 3 and the variable pump assembly 4, only the cooling and lubricating oil required by other lubrication oil circuit interfaces 14 is provided.

[0085] When a wet clutch engages in the transmission system and then immediately disengages:

[0086] The clutch friction pair has generated heat. Although the wet clutch is not being used continuously, cooling and lubrication flow is still required for heat dissipation. By controlling the operation of the solenoid directional valve 10 and energizing the first solenoid proportional pressure regulating valve 4b, the variable pump 4a continues to output hydraulic oil at a large displacement, ensuring that the wet clutch still has sufficient cooling and lubrication flow in the disengaged state to meet the heat dissipation requirements of the wet clutch.

[0087] Furthermore, in this embodiment, the amount of cooling and lubrication flow required for the wet clutch to engage in the transmission system depends not only on the actual cooling and lubrication flow rate but also on the temperature of the cooling and lubrication oil. Therefore, by calibrating the actual heat generation and dissipation of the wet clutch, the specific cooling and lubrication flow rate and oil temperature values ​​required for engagement under different loads, torques, and time conditions are determined. These values ​​are then applied to the transmission system with the wet clutch, i.e., adjusting the displacement of the variable pump assembly 4 under different operating conditions. During calibration, the current value of the first electromagnetic proportional pressure regulating valve, the control duration of the first electromagnetic proportional pressure regulating valve, and the opening duration of the electromagnetic directional valve can be selected for calibration.

[0088] Furthermore, in this embodiment, the amount of oil in the wet clutch lubrication circuit 11 of the wet clutch hydraulic control system can be calibrated according to the actual condition of the prime mover 3 and the variable pump assembly 4.

[0089] Furthermore, in this embodiment, the wet clutch hydraulic control system uses a temperature sensor 9 to monitor the actual temperature of the cooling lubricating oil and to monitor the temperature of the wet clutch lubrication circuit 11.

[0090] With the temperature of the lubricating oil circuit 11 of the wet clutch known and the load during the engagement process of the wet clutch known, the cooling requirements of the wet clutch are met by adjusting the first electromagnetic proportional pressure regulating valve 4b to the calibrated value of the actual heat dissipation requirements of the wet clutch.

[0091] Temperature sensor 9 in the hydraulic control system of the wet clutch can be removed. When removing it, a safety flow value can be calibrated, i.e., a larger flow rate is increased and a longer cooling and lubrication time is maintained to ensure that the wet clutch dissipates heat sufficiently.

[0092] This invention enables control over the cooling and lubrication flow required by the wet clutch during operation, allowing for precise control based on usage needs. This ensures the wet clutch does not fail due to overheating, while also reducing or blocking the cooling and lubrication flow when less is needed, thus lowering transmission system energy consumption and improving overall efficiency. The effects are particularly pronounced for wet clutch transmission systems with prolonged slippage.

[0093] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulic control system for a wet clutch, characterized by, The oil tank (1) is connected with a variable pump assembly (4), the variable pump assembly (4) is connected with a prime mover (3), and the variable pump assembly (4) can adjust the hydraulic system supply flow; The output end of the variable pump assembly (4) comprises three paths, the first path is sequentially connected with a main pressure regulating valve (6) and an inlet of an oil cooler (8), the second path is connected with an inlet of a second electromagnetic proportional pressure regulating valve (7), and the third path is connected with a main oil path interface (13); The outlet of the oil cooler (8) is divided into two paths, one path is sequentially connected with an electromagnetic reversing valve (10) and a lubricating cavity of a wet clutch group (12), and the other path is connected with other lubricating oil path interfaces (14); The second electromagnetic proportional pressure regulating valve (7) is connected with a piston cavity of the wet clutch group (12).

2. A hydraulic control system for a wet clutch according to claim 1, wherein, The variable pump assembly (4) comprises a variable pump (4a) and a first electromagnetic proportional pressure regulating valve (4b) connected with each other, and the outlet of the variable pump (4a) and the outlet of the first electromagnetic proportional pressure regulating valve (4b) are both connected with a piston cylinder (4c).

3. A hydraulic control system for a wet clutch according to claim 2, wherein, A first filter (2) is arranged between the variable pump assembly (4) and the oil tank (1); The output end of the variable pump assembly (4) is connected with a second filter (5), and the second filter (5) is respectively connected with the inlet of the main pressure regulating valve (6), the inlet of the second electromagnetic proportional pressure regulating valve (7) and the main oil path interface (13).

4. A hydraulic control system for a wet clutch according to claim 3, wherein The inlet of the variable pump (4a) is connected with the outlet of the first filter (2), the outlet of the variable pump (4a) is connected with the inlet of the second filter (5), and the outlet of the second filter (5) is connected with the inlet of the first electromagnetic proportional pressure regulating valve (4b).

5. A hydraulic control system for a wet clutch according to claim 1, wherein, A wet clutch lubricating oil path (11) is arranged between the electromagnetic reversing valve (10) and the wet clutch group (12).

6. A hydraulic control system for a wet clutch according to claim 1, wherein, A temperature sensor (9) is further arranged at the output end of the oil cooler (8).

7. A hydraulic control method for a wet clutch of the system according to claim 1, characterized by, The following steps are included: When the wet clutch has no cooling lubrication requirement, the electromagnetic reversing valve (10) is closed, and the hydraulic oil enters the lubricating oil path interface (14) and the main oil path interface (13) after passing through the variable pump assembly (4); When the wet clutch has cooling lubrication requirement, the electromagnetic reversing valve (10) is opened, the displacement of the variable pump assembly (4) is increased, and the hydraulic oil enters the wet clutch group (12), the lubricating oil path interface (14) and the main oil path interface (13) after passing through the variable pump assembly (4); When the wet clutch generates heat, the parameters of the cooling lubricating oil required by the wet clutch under different working conditions are calibrated, when the wet clutch generates heat, the parameters of the cooling lubricating oil required by the wet clutch are determined according to the current working condition information, and the displacement of the variable pump assembly (4) and the opening of the electromagnetic reversing valve (10) are adjusted.

8. The hydraulic control method of a wet clutch according to claim 7, wherein When the wet clutch has no cooling lubrication requirement, the following steps are included: When the wet clutch is in a separated state in the transmission system, the second electromagnetic proportional pressure regulating valve (7) and the electromagnetic reversing valve (10) are closed, the oil delivered by the variable pump assembly (4) is divided into two paths, one path is delivered to the other lubricating oil path interface (14) after passing through the main pressure regulating valve (6) and the oil cooler (8), and the other path is delivered to the main oil path interface (13); When the wet clutch has cooling and lubrication requirements, the following steps are included: When the wet clutch is changed from disengagement to engagement in the transmission system, the second electromagnetic proportional pressure regulating valve (7) and the electromagnetic reversing valve (10) are started, the displacement of the variable pump assembly (4) is increased, and the oil delivered by the variable pump assembly (4) is divided into three paths: The first path is divided into two sub-paths after passing through the main pressure regulating valve (6) and the oil cooler (8), the first sub-path enters other lubricating oil path interfaces (14), and the second sub-path enters the wet clutch group (12) after passing through the electromagnetic reversing valve (10); The second path enters the wet clutch group (12) after passing through the second electromagnetic proportional pressure regulating valve (7); The third path is delivered to the main oil path interface (13); When the wet clutch always remains in the engaged state in the transmission system, the electromagnetic reversing valve (10) is closed, and the displacement of the variable pump assembly (4) is reduced.

9. The hydraulic control method of a wet clutch according to claim 7, wherein, The current working condition information includes the rotational speed, working time, and torque of the wet clutch.

10. The hydraulic control method of a wet clutch according to claim 7, wherein The parameters of the cooling and lubricating oil include the required flow rate, temperature, and cooling time of the cooling and lubricating oil for the wet clutch.

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