A tractor power shift electro-hydraulic control system

Abstract

The present invention relates to the technical field of tractors, and discloses a tractor power shift electro-hydraulic control system, comprising: an oil tank, which is used as a tractor gearbox housing for storing oil; a gear pump, which is connected to the oil tank and used to extract oil; an electro-hydraulic control valve group, which is connected to the gear pump, and which includes a plurality of solenoid valves, the oil inlet ends of which are connected to the oil output end of the gear pump, and the output ends of which are respectively connected to corresponding actuators; and an emptying reversing valve, the liquid inlet end of which is connected to the oil output end of the gear pump, and the liquid outlet end of which is connected to a plurality of oil circuits. The tractor power shift electro-hydraulic control system can prevent air from remaining in the hydraulic system, save power consumption, reduce system heating, and extend the service life of hydraulic components.

Description

Technical Field

[0001] The invention relates to the technical field of tractors, and in particular to a tractor power shift electro-hydraulic control system. Background Art

[0002] When the tractor is initially assembled or repaired, there is no hydraulic oil in the hydraulic pipeline; when the tractor is left unused for a long time, the oil in the high part of the hydraulic system pipeline will flow to the low part due to its own weight, so there will be air in the hydraulic pipeline. When there is air in the oil, after the hydraulic system is running, the air in the oil will affect the normal operation of the system, causing a sense of frustration when the wet clutch is separated and engaged. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a tractor power shift electro-hydraulic control system, which can prevent air from remaining in the hydraulic system, save power consumption, reduce system heating, and extend the service life of hydraulic components.

[0004] The technical solution provided by the present invention is as follows:

[0005] A tractor power shift electro-hydraulic control system, comprising:

[0006] An oil tank, which serves as a tractor gearbox housing and is used to store oil;

[0007] A gear pump, the gear pump is connected to the oil tank and is used to extract oil;

[0008] An electro-hydraulic control valve group, the electro-hydraulic control valve group is connected to the gear pump, the electro-hydraulic control valve group comprises a plurality of solenoid valves, the oil inlet ends of the plurality of solenoid valves are connected to the oil output end of the gear pump, and the output ends of the plurality of solenoid valves are respectively connected to corresponding actuators;

[0009] An emptying reversing valve, wherein the liquid inlet end of the emptying reversing valve is communicated with the oil output end of the gear pump, and the liquid outlet end of the emptying reversing valve is connected to a plurality of oil circuits.

[0010] In this technical solution, when the tractor is initially assembled, placed for a long time, or repaired and maintained, the oil in the high part of the hydraulic system pipeline will flow to the low part due to the influence of its own weight, so that air will exist in the hydraulic pipeline. When there is air in the oil, after the hydraulic system is running, the air in the oil will affect the normal operation of the system. Under the action of the emptying reversing valve, when the tractor is started, the air in the system can be exhausted to ensure that there is no air in the hydraulic oil circuit when the system is working normally.

[0011] Further preferably, it also includes: a system pressure control valve;

[0012] The fluid inlet end of the system pressure control valve is communicated with the oil output end of the gear pump, and the fluid outlet end of the system pressure control valve is connected to a plurality of oil circuits.

[0013] Further preferably, the multiple solenoid valves include a forward high-speed control valve, a forward low-speed control valve, and a reverse gear control valve, and the electro-hydraulic control valve group is provided with a P port, a Hi port, a Low port, and a REV port; the P port serves as a liquid inlet of the electro-hydraulic control valve group, the liquid inlet end of the P port is connected to the gear pump, and the liquid outlet end of the P port is respectively connected to the liquid inlet ends of the system pressure control valve, the forward high-speed control valve, the forward low-speed control valve, the reverse gear control valve, and the emptying reversing valve;

[0014] The actuator includes a forward high-speed wet clutch, a forward low-speed wet clutch, and a reverse speed wet clutch; the forward high-speed control valve is connected to the forward high-speed wet clutch via the Hi port, the forward low-speed control valve is connected to the forward low-speed wet clutch via the Low port, and the reverse speed control valve is connected to the reverse speed wet clutch via the REV port.

[0015] In this technical solution, when the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse wet clutch are not working, all the oil will overflow from the system pressure control valve in the electro-hydraulic control valve group to the lubrication system or return to the oil tank, which will cause power loss, which is then converted into heat energy to cause the hydraulic oil temperature to rise, and then the oil deteriorates, which reduces the service life of the components. In order to reduce overflow losses, when the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse wet clutch are not working, the emptying reversing valve will continue to be energized, so that the oil will pass directly to the lubrication system or return to the oil tank through the emptying reversing valve, allowing the gear pump to run without load, that is, all the oil output by the pump will flow to the lubrication system or return to the oil tank at zero pressure or low pressure, which can save power consumption, reduce system heating, and extend service life.

[0016] Further preferably, the oil circuit includes a first oil return circuit;

[0017] The first oil return circuit includes a lubrication pressure control valve and a T-port arranged on the electro-hydraulic control valve group. The liquid inlet end of the lubrication pressure control valve is respectively connected to the system pressure control valve and the drain reversing valve, and the liquid outlet end of the lubrication pressure control valve is connected to the oil tank via the T-port to form a circulation loop.

[0018] Further preferably, the oil circuit further includes a second transmission system lubricating oil circuit;

[0019] The second transmission system lubrication oil circuit includes a Lub port arranged on the electro-hydraulic control valve group, the liquid inlet end of the Lub port is respectively connected to the system pressure control valve and the emptying reversing valve, the liquid outlet end of the Lub port is connected to a transmission system lubrication damping plug, the outlet end of the transmission system lubrication damping plug is connected to the oil tank, and the transmission system lubrication damping plug is used for forced lubrication of the tractor transmission system.

[0020] Further preferably, a wet clutch lubricating oil circuit is provided on the second transmission system lubricating oil circuit, and the fluid outlet ends of the wet clutch lubricating oil circuit are respectively connected to the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse-speed wet clutch.

[0021] Further preferably, it also includes: a system accumulator;

[0022] The two ends of the system accumulator are connected to the gear pump and the P port respectively. The system accumulator is used to play a buffering role when the forward high-speed wet clutch, the forward low-speed wet clutch and the reverse gear wet clutch are separated and combined.

[0023] In the present technical solution, the system accumulator is an accumulator that acts as a buffer when the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse gear wet clutch are separated and engaged. When the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse gear wet clutch are engaged and separated, the connected load will feedback the impact to the tractor, causing jerking fluctuations in the hydraulic system. The system accumulator can absorb and release the impact caused by the engagement and separation of the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse gear wet clutch, and acts as a buffer for the hydraulic system, making the hooking smoother. As an auxiliary power source, it can reduce the power of the pump, improve efficiency, reduce temperature rise, save energy, and reduce system energy loss and the heat caused by it.

[0024] Further preferably, it also includes: a hydraulic radiator;

[0025] One end of the hydraulic radiator is connected to the gear pump, and the other end of the hydraulic radiator is respectively connected to the P port and the system accumulator. The hydraulic radiator is used to cool the oil.

[0026] In this technical solution, the hydraulic radiator is a device used to cool the oil in the hydraulic system. The oil undergoes efficient heat exchange with the forced-flowing cold air in the heat exchanger, so that the oil temperature drops to the operating temperature to ensure that the system can continue to operate normally and that work can proceed smoothly.

[0027] Further preferably, it also includes: an oil suction filter;

[0028] One end of the oil suction filter is connected to the oil tank, and the other end of the oil suction filter is connected to the gear pump. The oil suction filter is used to filter the oil entering the gear pump.

[0029] In this technical solution, the oil suction filter is installed at the oil suction port of the gear pump to protect the gear pump and other hydraulic components to avoid the suction of pollutants and impurities, effectively control the pollution of the hydraulic system, and adjust the cleanliness of the hydraulic system.

[0030] Further preferably, it also includes: a pressure oil line oil filter;

[0031] One end of the pressure oil circuit filter is connected to the hydraulic radiator, and the other end of the pressure oil circuit filter is respectively connected to the P port and the system accumulator. The pressure oil circuit filter is used for secondary filtering of the oil.

[0032] In this technical solution, the main function of the pressure oil circuit filter is to filter the oil. Various impurities are inevitably present in the hydraulic system. The cleanliness of the oil can be further improved by the pressure oil circuit filter.

[0033] Compared with the prior art, the tractor power shift electro-hydraulic control system of the present invention has the following beneficial effects:

[0034] In the present invention, the tractor power shift electro-hydraulic control system can exhaust the air in the system through the emptying reversing valve when the tractor is working, so as to ensure that there is no air in the hydraulic oil circuit when the system is working normally; when the forward high-speed wet clutch, the forward low-speed wet clutch and the reverse gear wet clutch are not working, the emptying reversing valve will be continuously energized, so that the oil will directly pass through the emptying reversing valve to the lubrication system or the return oil tank, so that the gear pump can run without load, that is, the oil output by the pump will all flow to the lubrication system or the return oil tank at zero pressure or low pressure, so that power consumption can be saved, the heat of the system can be reduced, and the service life can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The preferred implementation scheme will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and their implementation methods.

[0036] Figure 1 is a hydraulic principle diagram of the tractor power shift electro-hydraulic control system of this embodiment;

[0037] Figure 2 1 is a hydraulic principle diagram of the electro-hydraulic control valve group of this embodiment.

[0038] Description of Figure Numbers:

[0039] 1. Oil tank, 2. Oil suction filter, 3. Gear pump, 4. Hydraulic radiator, 5. Pressure oil line filter, 6. System accumulator, 7. Electro-hydraulic control valve group, 8. Forward high-speed wet clutch, 9. Forward low-speed wet clutch, 10. Reverse gear wet clutch, 11. Transmission lubrication damping plug, 12. System pressure control valve, 13. Forward high-speed control valve, 14. Forward low-speed control valve, 15. Reverse gear control valve, 16. Drain reversing valve, 17. Lubrication pressure control valve, 18. P port, 19. T port, 20. Lub port, 21. Hi port, 22. Low port, 23. REV port. DETAILED DESCRIPTION

[0040] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0041] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections.

[0042] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0043] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0044] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of the various components of the present invention are not absolute but relative. These descriptions are appropriate when these components are in the positions shown in the drawings. If the descriptions of the positions of these components change, the indications of these directions also change accordingly.

[0045] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the present application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined. In addition, it should be noted that, unless otherwise clearly stipulated and defined, the term "connection" 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, an indirect connection through an intermediate medium, or it can be a connection between the two elements.

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0047] As a specific example, Figure 1 , Figure 2 As shown, this embodiment provides a tractor power shift electro-hydraulic control system, including: an oil tank 1, a gear pump 3, an electro-hydraulic control valve group 7 and an emptying reversing valve 16. The oil tank 1 serves as a tractor gearbox housing for storing oil. The gear pump 3 is connected to the oil tank 1 for extracting oil. The electro-hydraulic control valve group 7 is connected to the gear pump 3, and the electro-hydraulic control valve group 7 includes a plurality of solenoid valves, the oil inlet ends of the plurality of solenoid valves are connected to the oil output end of the gear pump 3, and the output ends of the plurality of solenoid valves are respectively connected to corresponding actuators. The liquid inlet end of the emptying reversing valve 16 is connected to the oil output end of the gear pump 3, and the liquid outlet end of the emptying reversing valve 16 is connected to a plurality of oil circuits.

[0048] In this embodiment, the emptying reversing valve 16 is preferably arranged in the electro-hydraulic control valve group 7, so that the integration is higher and more compact. The outlet end of the emptying reversing valve 16 is connected to an oil circuit or multiple parallel oil circuits. When the tractor is initially assembled, placed for a long time or repaired and maintained, the oil in the high part of the hydraulic system pipeline will flow to the low part due to the influence of its own weight, so that air will exist in the hydraulic pipeline. When there is air in the oil, after the hydraulic system is running, the air in the oil will affect the normal operation of the system. Under the action of the emptying reversing valve 16, when the tractor is started, the air in the system can be exhausted to ensure that there is no air in the hydraulic oil circuit when the system is working normally.

[0049] Furthermore, the tractor power shift electro-hydraulic control system also includes: a system pressure control valve 12, the liquid inlet end of the system pressure control valve 12 is respectively connected in parallel with a plurality of solenoid valves, the liquid outlet end of the system pressure control valve 12 is connected to a plurality of oil circuits, the plurality of solenoid valves are preferably solenoid proportional valves, and the electric curve proportional control of the solenoid valve realizes the wet clutch to be connected and separated according to the curve to achieve different operating states. Among them, the plurality of solenoid valves include a forward high-speed control valve 13, a forward low-speed control valve 14, and a reverse gear control valve 15, and the electro-hydraulic control valve group 7 is provided with a P port 18, a Hi port 21, a Low port 22, and a REV port 23. The P port 18 serves as the liquid inlet of the electro-hydraulic control valve group 7, the liquid inlet end of the P port 18 is connected to the gear pump 3, and the liquid outlet end of the P port 18 is respectively connected to the system pressure control valve 12, the forward high-speed control valve 13, the forward low-speed control valve 14, the reverse gear control valve 15, and the emptying reversing valve 16. The liquid inlet of the system pressure control valve 12 is arranged between the liquid outlet of the P port 18 and the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse control valve 15; the liquid inlet of the emptying reversing valve 16 is respectively connected to the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse control valve 15; the liquid outlet of the emptying reversing valve 16 and the liquid outlet of the system pressure control valve 12 are both connected to a plurality of parallel oil circuits. The forward high-speed control valve 13 is connected to the forward high-speed wet clutch 8 via the Hi port 21, the forward low-speed control valve 14 is connected to the forward low-speed wet clutch 9 via the Low port 22, and the reverse control valve 15 is used to connect to the reverse wet clutch 10 via the REV port 23.

[0050] In this embodiment, the emptying reversing valve 16 is a two-position two-way electromagnetic switch valve, which is normally closed in the oil circuit. When the tractor is working, the emptying reversing valve 16 will be energized due to the start-up command, the electromagnetic coil will be attracted, and the oil channel of the emptying reversing valve 16 will be converted to the connected state. At this time, the oil will circulate in the system pipeline without load to exhaust the air. When the air is exhausted, the electromagnetic coil of the emptying reversing valve 16 will be powered off, and the oil channel will be converted to the closed state, which is the normal working state of the hydraulic system. When the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are all in the closed state, in order to reduce overflow loss, the emptying reversing valve 22 will continue to be energized, so that the oil passes directly to the lubrication system or the return oil tank through the emptying reversing valve 22, so that the gear pump 3 runs without load, that is, the oil output by the pump is all flowed to the lubrication system or the return oil tank at zero pressure or low pressure, so that power consumption can be saved, the heating of the system can be reduced, and the service life can be extended.

[0051] In another embodiment, if Figure 1 , Figure 2As shown, on the basis of the above embodiment, the oil circuit includes a first oil return circuit; the first oil return circuit includes a lubrication pressure control valve 17 and a T-port 19 provided on the electro-hydraulic control valve group 7, the liquid inlet end of the lubrication pressure control valve 17 is respectively connected to the system pressure control valve 12 and the drain reversing valve 16, and the liquid outlet end of the lubrication pressure control valve 17 is connected to the oil tank 1 via the T-port 19 to form a circulation loop.

[0052] Furthermore, the oil circuit also includes a second transmission system lubricating oil circuit; the second transmission system lubricating oil circuit includes a Lub port 20 provided on the electro-hydraulic control valve group 7, the liquid inlet end of the Lub port 20 is respectively connected to the system pressure control valve 12 and the emptying reversing valve 16, the liquid outlet end of the Lub port 20 is connected to the transmission system lubricating damping plug 11, the outlet end of the transmission system lubricating damping plug 11 is connected to the oil tank 1, and the transmission system lubricating damping plug 11 is used for forced lubrication of the tractor transmission system.

[0053] Furthermore, a wet clutch lubricating oil circuit is provided on the second transmission system lubricating oil circuit, and the liquid outlet ends of the wet clutch lubricating oil circuit are respectively connected to the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10.

[0054] Preferably, the liquid inlet end of the wet clutch lubrication oil circuit is connected between the Lub port 20 and the transmission system lubrication damping plug 11, and the liquid outlet end is respectively connected to the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10, to provide lubrication for each wet clutch.

[0055] In another embodiment, if Figure 1 , Figure 2 As shown, on the basis of the above embodiment, the tractor power shift electro-hydraulic control system further includes: a system accumulator 6. The two ends of the system accumulator 6 are respectively connected to the gear pump 3 and the P port 18. The system accumulator 6 is used to ensure the stability of the forward high-speed wet clutch 8, the forward low-speed wet clutch 9 and the reverse wet clutch 10 when they are separated and combined. The system accumulator 6 is an accumulator that acts as a buffer when the forward high-speed wet clutch 8, the forward low-speed wet clutch 9 and the reverse wet clutch 10 are separated and combined. When the forward high-speed wet clutch 8, the forward low-speed wet clutch 9 and the reverse wet clutch 10 are combined and separated, the connected load will feedback the impact to the tractor, which will cause the hydraulic system to fluctuate. The system accumulator 6 can absorb and release the impact caused by the combination and separation of the forward high-speed wet clutch 8, the forward low-speed wet clutch 9 and the reverse wet clutch 10, and play a buffering role on the hydraulic system, making the hooking more stable. As an auxiliary power source, it can reduce the power of the pump, improve efficiency, reduce temperature rise, save energy, and reduce system energy loss and the resulting heat.

[0056] Furthermore, if Figure 1 , Figure 2 As shown, the tractor power shift electro-hydraulic control system also includes: a hydraulic radiator 4, an oil suction filter 2 and a pressure oil circuit oil filter 5. One end of the hydraulic radiator 4 is connected to the gear pump 3, and the other end of the hydraulic radiator 4 is respectively connected to the P port 18 and the system accumulator 6. The hydraulic radiator 4 is used to cool the oil. The hydraulic radiator 4 is a device for cooling the oil in the hydraulic system. The oil is efficiently heat-exchanged with the forced cold air in the heat exchanger, so that the oil temperature is reduced to the working temperature to ensure that the system can continue to operate normally and work can be carried out smoothly. One end of the oil suction filter 2 is connected to the oil tank 1, and the other end of the oil suction filter 2 is connected to the gear pump 3. The oil suction filter 2 is used to filter the oil entering the gear pump 3. The oil suction filter 2 is installed at the oil suction port of the gear pump 3 to protect the gear pump 3 and other hydraulic components to avoid the inhalation of contaminated impurities, effectively control the pollution of the hydraulic system, and adjust the cleanliness of the hydraulic system. One end of the pressure oil filter 5 is connected to the hydraulic radiator 4, and the other end of the pressure oil filter 5 is connected to the P port 18 and the system accumulator 6 respectively. The pressure oil filter 5 is used for secondary filtering of the oil. The main function of the pressure oil filter 5 is to filter the oil. Various impurities are inevitably present in the hydraulic system. The cleanliness of the oil can be further improved by the pressure oil filter 5.

[0057] When the tractor is working normally, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are energized and triggered, which will connect the right oil circuit of the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15, respectively making the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 engage, drive the corresponding mechanism, and make the forward high-speed, forward low-speed, and reverse gear work. The forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 lose power, making the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 in the left position, closing the oil circuit, respectively making the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 separate, and the corresponding mechanism stops working, so that the forward high-speed, forward low-speed, and reverse gear stop working. The drain reversing valve 16 will be energized, so that the oil flows directly to the lubrication system or the oil tank through the drain reversing valve 16. The forward high gear wet clutch 8, the forward low gear wet clutch 9, and the reverse gear wet clutch 10 cannot be engaged at the same time.

[0058] In this embodiment, the specific oil circuit route of the tractor power shift electro-hydraulic control system is as follows:

[0059] (I) Oil drain route:

[0060] like Figure 1 , Figure 2 As shown, each component is in the initial state. When the tractor starts, the drain reversing valve 16 will be energized due to the start command, the electromagnetic coil will be attracted, and the oil channel will be converted to the connected state. The oil enters from the P port 18 of the electro-hydraulic control valve group 7 through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and preferentially passes through the right position of the drain reversing valve 16. Regardless of whether the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are in the connected state, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop. At this time, the oil will circulate in the system pipeline without load, exhausting the air, and the air will not enter the wet clutches. When the air is exhausted, if the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are all in the closed state, the emptying reversing valve 16 will continue to be energized, and all the oil will flow to the lubrication system or return to the oil tank, thereby reducing power consumption. When the air is exhausted, if one of the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 is in the connected state, the emptying reversing valve 16 will lose power.

[0061] (ii) Wet clutch working oil circuit route: Figure 1 , Figure 2 As shown, each component is in the initial state after starting the emptying.

[0062] 1. Forward high-end wet clutch 8 working oil line route:

[0063] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0064] When the forward high-speed control valve 13 is energized, the electromagnetic coil of the forward high-speed control valve 13 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the forward high-speed control valve 13 to fill the forward high-speed wet clutch 8. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the forward high-speed control valve 13 is connected, the oil flows into the forward high-speed wet clutch 8, causing it to engage according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the forward high-speed wet clutch 8 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0065] When the forward high-speed control valve 13 is powered off, the electromagnetic coil of the forward high-speed control valve 13 is released and in the left position, the oil circuit is closed, and the oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, and the pressure oil circuit filter 5. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are in the closed state, and the emptying reversing valve 16 is powered again. The oil is diverted to the right position through the emptying reversing valve 16, and one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop. The oil in the forward high-speed wet clutch 8 passes through the forward high-speed control valve 13 to the left position, bypasses the system pressure control valve 12, is diverted to various lubrication systems, and finally returns to the oil tank 1.

[0066] 2. Working oil line of forward low gear wet clutch 9:

[0067] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0068] When the forward low-speed control valve 14 is energized, the electromagnetic coil of the forward low-speed control valve 14 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the forward low-speed control valve 14 to fill the forward low-speed wet clutch 9. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the forward low-speed control valve 14 is connected, the oil flows into the forward low-speed wet clutch 9, causing it to engage according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the forward low-speed wet clutch 9 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0069] When the forward low gear control valve 14 is powered off, the electromagnetic coil of the forward low gear control valve 14 is released and in the left position, the oil circuit is closed, and the oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, and the pressure oil circuit filter 5. At this time, the forward high gear control valve 13, the forward low gear control valve 14, and the reverse gear control valve 15 are in the closed state, and the emptying reversing valve 16 is powered again. The oil is diverted to the right position through the emptying reversing valve 16, and one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high gear wet clutch 8, the forward low gear wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop. The oil in the forward low-speed wet clutch 9 passes through the left position of the forward low-speed control valve 14, bypasses the system pressure control valve 12, is diverted to various lubrication systems, and finally returns to the oil tank 1.

[0070] 3. Reverse gear wet clutch 10 working oil line route:

[0071] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0072] When the reverse gear control valve 15 is energized, the electromagnetic coil of the reverse gear control valve 15 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the reverse gear control valve 15 to fill the reverse gear clutch 10. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the reverse gear control valve 15 is connected, the oil flows into the reverse gear wet clutch 10, so that it is engaged according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the reverse gear wet clutch 10 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0073] When the reverse gear control valve 15 is powered off, the electromagnetic coil of the reverse gear control valve 15 is released and in the left position, the oil circuit is closed, and the oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, and the pressure oil circuit filter 5. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are in the closed state, and the emptying reversing valve 16 is powered again. The oil is diverted to the right position through the emptying reversing valve 16, and one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop. The oil in the reverse gear wet clutch 10 passes through the reverse gear control valve 15 to the left position, bypasses the system pressure control valve 12, is diverted to various lubrication systems, and finally returns to the oil tank 1.

[0074] (III) Switching the working oil route between wet clutches: Figure 1 , Figure 2 As shown, each component is in the initial state after starting the emptying.

[0075] 1. Switching oil route between forward high-speed wet clutch 8 and forward low-speed wet clutch 9:

[0076] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0077] When the forward high-speed control valve 13 is energized, the electromagnetic coil of the forward high-speed control valve 13 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the forward high-speed control valve 13 to fill the forward high-speed wet clutch 8. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the forward high-speed control valve 13 is connected, the oil flows into the forward high-speed wet clutch 8, causing it to engage according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the forward high-speed wet clutch 8 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0078] When switching between forward high gear and forward low gear, when switching from forward high gear to forward low gear, that is, when the forward high gear control valve 13 is powered off and the forward low gear control valve 14 is powered on, the electromagnetic coil of the forward high gear control valve 13 is released and is in the left position, and the oil circuit is closed. The electromagnetic coil of the forward low gear control valve 14 is engaged and is in the right position, and the oil circuit is connected. When switching, the power off and power on of each proportional valve are carried out simultaneously according to the current curve. The switching between the forward high gear wet clutch 8 and the forward low gear wet clutch 9 is also separated and combined at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and the system pressure control valve 12 to control the system pressure. At this time, the forward high-speed control valve 13 is in the left position, the oil circuit is closed, the forward low-speed control valve 14 is in the right position, the oil circuit is connected, the reverse gear control valve 15 is in the left position, the oil circuit is closed, and the oil in the forward high-speed wet clutch 8 passes through the forward high-speed control valve 13 in the left position, bypassing the system pressure control valve 12 to be diverted to each lubrication system, and finally returns to the oil tank 1.

[0079] When the forward high-speed wet clutch 8 is separated, the oil enters through the P port of the electro-hydraulic control valve group 7, passes through the right position of the forward low-speed control valve 14, and fills the forward low-speed wet clutch 9. As the oil flows into the forward low-speed wet clutch 9, it is combined according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth combination of the wet clutch. At this time, the system accumulator 6 will absorb the system impact, so that the system pressure is stable, and the forward low-speed wet clutch 9 can be smoothly combined. The separation of the forward high-speed wet clutch 8 and the combination of the forward low-speed wet clutch 9 are carried out simultaneously to realize the switching between the forward high speed and the forward low speed. At the same time, it is divided through the system pressure control valve 12, and comes out from the Lub port 20 of the electro-hydraulic control valve group 7, respectively lubricating the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse wet clutch 10; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other path passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0080] 2. Switching oil route between forward high gear wet clutch 8 and reverse gear wet clutch 10:

[0081] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0082] When the forward high-speed control valve 13 is energized, the electromagnetic coil of the forward high-speed control valve 13 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the forward high-speed control valve 13 to fill the forward high-speed wet clutch 8. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the forward high-speed control valve 13 is connected, the oil flows into the forward high-speed wet clutch 8, causing it to engage according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the forward high-speed wet clutch 8 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0083] When switching between forward high gear and reverse gear, when switching from forward high gear to reverse gear, that is, when the forward high gear control valve 13 is powered off and the reverse gear control valve 15 is powered on, the electromagnetic coil of the forward high gear control valve 13 is released and is in the left position, and the oil circuit is closed. The electromagnetic coil of the reverse gear control valve 15 is engaged and is in the right position, and the oil circuit is connected. When switching, the proportional valves are powered off and powered on simultaneously according to the current curve. The switching between the forward high gear wet clutch 8 and the reverse gear wet clutch 10 is also separated and engaged at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and the system pressure control valve 12 to control the system pressure. At this time, the forward high-speed control valve 13 is in the left position, the oil circuit is closed, the reverse gear control valve 15 is in the right position, the oil circuit is connected, the forward low-speed control valve 14 is in the left position, the oil circuit is closed, and the oil in the forward high-speed wet clutch 8 passes through the forward high-speed control valve 13 in the left position, bypassing the system pressure control valve 12 to be diverted to each lubrication system, and finally returns to the oil tank 1.

[0084] When the forward high-speed wet clutch 8 is separated, the oil enters through the P port of the electro-hydraulic control valve group 7, passes through the right position of the reverse-speed control valve 15, and fills the reverse-speed wet clutch 10. As the oil flows to the reverse-speed wet clutch 10, it is engaged according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact, making the system pressure stable, and the reverse-speed wet clutch 10 can be smoothly engaged. The forward high-speed wet clutch 8 is separated and the reverse-speed wet clutch 10 is engaged at the same time, realizing the switching between the forward high-speed and reverse-speed. At the same time, it is divided through the system pressure control valve 12, and comes out from the Lub port 20 of the electro-hydraulic control valve group 7, respectively lubricating the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse-speed wet clutch 10; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other path passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0085] 3. Switching oil route between forward low gear wet clutch 9 and reverse gear wet clutch 10:

[0086] When the electro-hydraulic control valve is not connected, the oil enters through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil filter 5, and the P port 18 of the electro-hydraulic control valve group 7. At this time, the forward high-speed control valve 13, the forward low-speed control valve 14, and the reverse gear control valve 15 are closed. The emptying reversing valve 16 is continuously energized after being emptied. The oil is diverted to the right position of the emptying reversing valve 16. One way comes out from the Lub port 20 of the electro-hydraulic control valve group 7 to lubricate the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0087] When the forward low-speed control valve 14 is energized, the electromagnetic coil of the forward low-speed control valve 14 is energized in the right position, the oil circuit is connected, and the drain reversing valve 16 loses power at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and enters through the P port 18 of the electro-hydraulic control valve group 7, and passes through the right position of the forward low-speed control valve 14 to fill the forward low-speed wet clutch 9. At the same time, the system accumulator 6 is filled to buffer the system fluctuation. Since the forward low-speed control valve 14 is connected, the oil flows into the forward low-speed wet clutch 9, causing it to engage according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact to stabilize the system pressure, and the forward low-speed wet clutch 9 can be smoothly engaged. At the same time, the oil is split through the system pressure control valve 12, one way comes out from the Lub port 20 of the electro-hydraulic control valve group 7, and lubricates the forward high-speed wet clutch 8, the forward low-speed wet clutch 9, and the reverse gear wet clutch 10 respectively; and after lubricating the transmission system through the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other way passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0088] When switching between forward low gear and reverse gear, when switching from forward low gear to reverse gear, that is, when the forward low gear control valve 14 is powered off and the reverse gear control valve 15 is powered on, the electromagnetic coil of the forward low gear control valve 14 is released and is in the left position, and the oil circuit is closed. The electromagnetic coil of the reverse gear control valve 15 is engaged and is in the right position, and the oil circuit is connected. When switching, the proportional valves are powered off and powered on simultaneously according to the current curve. The switching between the forward low gear wet clutch 9 and the reverse gear wet clutch 10 is also separated and engaged at the same time. The oil passes through the oil tank 1, the oil suction filter 2, the gear pump 3, the hydraulic radiator 4, the pressure oil circuit filter 5, and the system pressure control valve 12 to control the system pressure. At this time, the forward low gear control valve 14 is in the left position, the oil circuit is closed, the reverse gear control valve 15 is in the right position, the oil circuit is connected, the forward high gear control valve 15 is in the left position, the oil circuit is closed, and the oil in the forward low gear wet clutch 9 passes through the left position of the forward low gear control valve 14, bypasses the system pressure control valve 12, and is diverted to each lubrication system, and finally returns to the oil tank 1.

[0089] When the forward low gear wet clutch 9 is separated, the oil enters through the P port of the electro-hydraulic control valve group 7, passes through the right position of the reverse gear control valve 15, and fills the reverse gear wet clutch 10. As the oil flows to the reverse gear wet clutch 10, it is engaged according to the current curve. Due to the load change, the system pressure control valve 12 will fluctuate briefly, affecting the system pressure, which will cause an impact on the smooth engagement of the wet clutch. At this time, the system accumulator 6 will absorb the system impact, so that the system pressure is stable, and the reverse gear wet clutch 10 can be smoothly engaged. The forward low gear wet clutch 9 is separated and the reverse gear wet clutch 10 is engaged at the same time, realizing the switching between the forward low gear and the reverse gear. At the same time, it is divided through the system pressure control valve 12, and comes out from the Lub port 20 of the electro-hydraulic control valve group 7, respectively lubricating the forward high gear wet clutch 8, the forward low gear wet clutch 9, and the reverse gear wet clutch 10; and after lubricating the transmission system from the transmission system lubrication damping plug 11, it enters the oil tank 1 to form a circulation loop. The other path passes through the lubrication pressure control valve 17 to control the lubrication pressure and directly enters the oil tank 1 to form a circulation loop.

[0090] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0091] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A tractor power shift electro-hydraulic control system, characterized in that: include: An oil tank, which serves as a tractor gearbox housing and is used to store oil; A gear pump, the gear pump is connected to the oil tank and is used to extract oil; An electro-hydraulic control valve group, the electro-hydraulic control valve group is connected to the gear pump, the electro-hydraulic control valve group comprises a plurality of solenoid valves, the oil inlet ends of the plurality of solenoid valves are connected to the oil output end of the gear pump, and the output ends of the plurality of solenoid valves are respectively connected to corresponding actuators; An emptying reversing valve, wherein the liquid inlet end of the emptying reversing valve is connected to the oil output end of the gear pump, and the liquid outlet end of the emptying reversing valve is connected to a plurality of oil circuits. The emptying reversing valve is a two-position two-way electromagnetic switch valve. Under the action of the emptying reversing valve, when the tractor is started, the air in the system is exhausted; A system pressure control valve, wherein the fluid inlet of the system pressure control valve is communicated with the fluid output of the gear pump, and the fluid outlet of the system pressure control valve is connected to a plurality of oil circuits; The oil circuit includes a first oil return circuit; the first oil return circuit includes a lubrication pressure control valve and a T-port arranged on the electro-hydraulic control valve group, the liquid inlet end of the lubrication pressure control valve is respectively connected to the system pressure control valve and the drain reversing valve, and the liquid outlet end of the lubrication pressure control valve is connected to the oil tank via the T-port to form a circulation loop.

2. The tractor power shift electro-hydraulic control system according to claim 1, characterized in that: The multiple solenoid valves include a forward high-speed control valve, a forward low-speed control valve, and a reverse gear control valve. The electro-hydraulic control valve group is provided with a P port, a Hi port, a Low port, and a REV port; the P port serves as a liquid inlet of the electro-hydraulic control valve group, the liquid inlet end of the P port is connected to the gear pump, and the liquid outlet end of the P port is respectively connected to the liquid inlet ends of the system pressure control valve, the forward high-speed control valve, the forward low-speed control valve, the reverse gear control valve, and the emptying reversing valve; The actuator includes a forward high-speed wet clutch, a forward low-speed wet clutch, and a reverse speed wet clutch; the forward high-speed control valve is connected to the forward high-speed wet clutch via the Hi port, the forward low-speed control valve is connected to the forward low-speed wet clutch via the Low port, and the reverse speed control valve is connected to the reverse speed wet clutch via the REV port.

3. The tractor power shift electro-hydraulic control system according to claim 2, characterized in that: The oil circuit also includes a second transmission system lubricating oil circuit; The second transmission system lubrication oil circuit includes a Lub port arranged on the electro-hydraulic control valve group, the liquid inlet end of the Lub port is respectively connected to the system pressure control valve and the emptying reversing valve, the liquid outlet end of the Lub port is connected to a transmission system lubrication damping plug, the outlet end of the transmission system lubrication damping plug is connected to the oil tank, and the transmission system lubrication damping plug is used for forced lubrication of the tractor transmission system.

4. The tractor power shift electro-hydraulic control system according to claim 3, characterized in that: A wet clutch lubricating oil circuit is provided on the second transmission system lubricating oil circuit, and the fluid outlet ends of the wet clutch lubricating oil circuit are respectively connected to the forward high-speed wet clutch, the forward low-speed wet clutch, and the reverse-speed wet clutch.

5. The tractor power shift electro-hydraulic control system according to claim 2, characterized in that: Also includes: System accumulator; The two ends of the system accumulator are connected to the gear pump and the P port respectively. The system accumulator is used to play a buffering role when the forward high-speed wet clutch, the forward low-speed wet clutch and the reverse gear wet clutch are separated and combined.

6. The tractor power shift electro-hydraulic control system according to claim 5, characterized in that: Also includes: Hydraulic radiator; One end of the hydraulic radiator is connected to the gear pump, and the other end of the hydraulic radiator is respectively connected to the P port and the system accumulator. The hydraulic radiator is used to cool the oil.

7. The tractor power shift electro-hydraulic control system according to claim 6, characterized in that: Also includes: Oil suction filter; One end of the oil suction filter is connected to the oil tank, and the other end of the oil suction filter is connected to the gear pump. The oil suction filter is used to filter the oil entering the gear pump.

8. The tractor power shift electro-hydraulic control system according to claim 7, characterized in that: Also includes: Pressure oil line filter; One end of the pressure oil circuit filter is connected to the hydraulic radiator, and the other end of the pressure oil circuit filter is respectively connected to the P port and the system accumulator. The pressure oil circuit filter is used for secondary filtering of the oil.

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