Gearbox structure combining power gear shifting and electric control hydraulic mechanical gear shifting and control method of gearbox structure

Abstract

The invention discloses a gearbox structure combining power gear shifting and electric control hydraulic mechanical gear shifting and a control method of the gearbox structure. The gearbox structure comprises a gearbox body, a hydraulic system and an electric control system. The gearbox body comprises an input shaft, a power fourth-gear gear, a power third-gear gear, a power second-gear gear, a power first-gear gear, a fourth-gear clutch, a third-gear clutch, a second-gear clutch and a first-gear clutch. The reverse transmission gear, the first transmission gear, the second transmission gear, the third transmission gear, the fourth transmission gear, the fifth transmission gear and the sixth transmission gear are fixedly arranged on the intermediate shaft in a sleeving mode, and the idle gear is arranged on the idle gear shaft in an empty sleeving mode. The device comprises an auxiliary variable-speed shaft, a reverse gear, a mechanical first-gear gear, a mechanical second-gear gear, a sixth transmission gear, a seventh transmission gear, a first synchronizer, a second synchronizer, an output shaft, a high-gear output gear, a low-gear output gear and a third synchronizer. The gearbox is simple and compact in structure, low in manufacturing cost and large in gear number.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gearbox, in particular to a gearbox structure combining power shift and electrically controlled hydraulic mechanical shift and a control method thereof. BACKGROUND

[0002] The multi-gear range power shift gearbox commonly used in agricultural machinery is composed of a main gearbox, a wet clutch and a full proportional valve to complete power shift, a main clutch in series, and a sub-gearbox completed by a set of electric motor and actuator to complete electrically controlled mechanical shift. The structure is complex, the motor and hydraulic system have high failure rate, and the full proportional valve and main clutch have high manufacturing and maintenance costs.

[0003] Referring to the Chinese patent application document with the patent publication number "CN114704599A", the present application provides a tractor power reversing and power high-low gear shift gearbox, which comprises a power reversing and power high-low module and a mechanical shift module. The power reversing and power high-low module is located in the front box body of the gearbox, and the mechanical shift module is located in the rear box body of the gearbox. The front box body of the gearbox and the rear box body of the gearbox are connected by a double-headed stud. The present application uses three wet clutches to realize power reversing and power high-low gear shift simultaneously by cooperating with electro-hydraulic control. However, the structure of the present application is complex, difficult to manufacture, assemble and maintain, requires two box bodies, occupies a large axial space, and has few gears, which cannot meet the complex and variable operation requirements of tractors. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a gearbox structure combining power shift and electrically controlled hydraulic mechanical shift and a control method thereof. The power shift and electrically controlled hydraulic mechanical shift in the gearbox structure are arranged in the same box body, the structure is simple and compact, the axial length is reduced, the manufacturing cost is low, easy to maintain, and the number of gears is large.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] A gearbox structure combining power shift and electrically controlled hydraulic mechanical shift, comprising: a gearbox body, a hydraulic system connected to the gearbox body, and an electric control system connected to the hydraulic system, wherein the gearbox body comprises:

[0007] an input shaft component, an intermediate shaft component, a sub-gearbox shaft component, an output shaft component, an idler shaft component, and an output component;

[0008] The input shaft component comprises: an input shaft A, a power fourth gear, a power third gear, a power second gear and a power first gear, a fourth clutch, a third clutch, a second clutch and a first clutch, the power fourth gear, the power third gear, the power second gear and the power first gear are sleeved on the input shaft A, the fourth clutch is arranged between the power fourth gear and the input shaft A, the power fourth gear can be connected with the input shaft A and rotate synchronously through the fourth clutch, the power third gear can be connected with the input shaft A and rotate synchronously through the third clutch, the power second gear can be connected with the input shaft A and rotate synchronously through the second clutch, and the power first gear can be connected with the input shaft A and rotate synchronously through the first clutch;

[0009] The intermediate shaft component comprises: an intermediate shaft B and a reverse transmission gear, a first transmission gear, a second transmission gear, a third transmission gear, a fourth transmission gear, a fifth transmission gear and a sixth transmission gear which are sleeved on the intermediate shaft B, wherein the first transmission gear is in meshing transmission with the power fourth gear, the third transmission gear is in meshing transmission with the power third gear, the fifth transmission gear is in meshing transmission with the power second gear, and the sixth transmission gear is in meshing transmission with the power first gear;

[0010] The idler shaft component comprises: an idler shaft F and an idler which are sleeved on the idler shaft F, and the idler is in meshing transmission with the reverse transmission gear;

[0011] The auxiliary transmission shaft component comprises: an auxiliary transmission shaft C, a reverse gear, a mechanical first gear, a mechanical second gear, an eighth transmission gear, a seventh transmission gear, a first synchronizer and a second synchronizer, the reverse gear, the mechanical first gear and the mechanical second gear are sleeved on the auxiliary transmission shaft C, the eighth transmission gear and the seventh transmission gear are fixedly sleeved on the auxiliary transmission shaft C, the first synchronizer and the second synchronizer are installed on the auxiliary transmission shaft C, the reverse gear is in meshing transmission with the idler, the mechanical first gear is in meshing transmission with the second transmission gear, the mechanical second gear is in meshing transmission with the fourth transmission gear, the reverse gear can be connected with the auxiliary transmission shaft C and rotate synchronously through the first synchronizer, and the mechanical first gear and the mechanical second gear can be connected with the auxiliary transmission shaft C and rotate synchronously through the second synchronizer;

[0012] The output component comprises: an output shaft G, a high gear output gear, a low gear output gear and a third synchronizer, the high gear output gear and the low gear output gear are sleeved on the output shaft G, the high gear output gear is in meshing transmission with the eighth transmission gear, and the low gear output gear is in meshing transmission with the seventh transmission gear.

[0013] In some embodiments, the tip circle diameters of the power fourth gear, power third gear, power second gear, and power first gear are different from each other; the tip circle diameters of the first transmission gear, second transmission gear, third transmission gear, fourth transmission gear, fifth transmission gear, and sixth transmission gear are different from each other; the tip circle diameters of the mechanical first gear, mechanical second gear, eighth transmission gear, and seventh transmission gear are different from each other; and the tip circle diameters of the high-gear output gear and the low-gear output gear are different from each other.

[0014] In some embodiments, the gearbox body further includes: a first gear cylinder, a second gear cylinder, a reverse gear cylinder, and high / low gear cylinders. The hydraulic system includes a working oil pump and a main transmission gear position valve block, a secondary transmission gear position valve block, and a high / low gear valve block. The main transmission gear position valve block includes an electro-hydraulic proportional directional valve K1, an electro-hydraulic proportional directional valve K2, a solenoid directional valve K3, and a solenoid directional valve K4. The secondary transmission gear position valve block includes a solenoid directional valve K5, a solenoid directional valve K6, and a solenoid directional valve K7. The high / low gear valve block includes a solenoid directional valve K9. The first inlet of the solenoid directional valve K4 is connected to the working oil pump, and the second inlet of the solenoid directional valve K4 is connected to the working oil pump via the electro-hydraulic proportional directional valve K2. The first inlet of the solenoid directional valve K3 is connected to the working oil pump, and the second inlet of the solenoid directional valve K4 is connected to the working oil pump via the electro-hydraulic proportional directional valve K1. The hydraulic system includes a working oil pump, a main transmission gear position valve block, a secondary transmission gear position valve block, and a high / low gear valve block. The inlets of valves K6, K7, and K9 are all connected to the working oil pump. The first-gear clutch and third-gear clutch are respectively connected to the two working ports of the solenoid directional valve K4. The second-gear clutch and fourth-gear clutch are respectively connected to the two working ports of the solenoid directional valve K3. The working port of the solenoid directional valve K5 is connected to the second-gear cylinder. The working port of the solenoid directional valve K6 is connected to the first-gear cylinder. The working port of the solenoid directional valve K7 is connected to the reverse gear cylinder. The working port of the solenoid directional valve K9 is connected to the high / low gear cylinder. The second-gear cylinder is used to drive the second synchronizer to engage with the mechanical first gear. The first-gear cylinder is used to drive the second synchronizer to engage with the mechanical second gear. The reverse gear cylinder is used to drive the first synchronizer to engage with the reverse gear. The high / low gear cylinder is used to drive the third synchronizer to engage with the low gear or to engage with the high output gear.

[0015] In some embodiments, the gearbox body further includes a four-wheel drive cylinder. In the gearbox body, one end of the output shaft G is fixedly connected to the front output component, and the other end is fixedly connected to the front-drive / four-wheel drive switching gear. The fourth synchronizer is coaxially fixed and rotates synchronously with the rear output component. The fourth synchronizer is rotatably arranged coaxially with the front-drive / four-wheel drive switching gear. The fourth synchronizer can engage with the front-drive / four-wheel drive switching gear and rotate synchronously. The hydraulic system includes a working oil pump and a four-wheel drive valve block. The four-wheel drive valve block includes a solenoid directional valve K8. The oil inlet of the solenoid directional valve K8 is connected to the working oil pump, and the working oil port is connected to the four-wheel drive cylinder. The four-wheel drive cylinder is used to push the fourth synchronizer to engage with the front-drive / four-wheel drive switching gear.

[0016] In some embodiments, a sleeve is loosely fitted on the shaft of the fourth synchronizer, and the front-drive / four-wheel drive switching gear rotates synchronously and circumferentially with the sleeve.

[0017] In some embodiments, a pressure sensor P is installed on the oil circuit connecting the working oil pump to the main transmission gear position valve block, the auxiliary transmission gear position valve block, and the high and low gear position valve blocks, and the pressure sensor P is connected to the electronic control system.

[0018] In some embodiments, a speed measuring gear is also fixedly installed on the output shaft G, and a speed sensor n1 for detecting the speed of the reverse gear and a speed sensor n2 for detecting the speed of the speed measuring gear are also installed in the gearbox. Both speed sensor n1 and speed sensor n2 are connected to the electronic control system.

[0019] In some embodiments, the oil in the clutches and cylinders that have stopped working in the gearbox body returns to the oil tank through the return oil circuit. The working oil pump is connected to the oil tank to supply oil. The oil tank is also connected to the cooling oil pump, which is connected to a radiator. The oil returns to the oil tank after being cooled by the radiator.

[0020] The present invention also discloses a control method for a gearbox structure that combines power shift and electro-hydraulic mechanical shift, which is applied to the gearbox structure that combines power shift and electro-hydraulic mechanical shift as described in claim 1.

[0021] In some embodiments, the following steps are included:

[0022] When starting and shifting to power gear, first control the solenoid directional valve that switches to the corresponding gear, and then control the pressure increase process of the corresponding electro-hydraulic proportional directional valve based on the speed and acceleration changes obtained from speed sensor n1 and speed sensor n2.

[0023] When shifting gears using a mechanical synchronizer, first disengage the power gear clutch, then switch gears using the mechanical synchronizer. After the shift is complete, the power gear clutch engages the gear through creeping and slipping.

[0024] After shifting gears, the engine speed, power gear output speed, and overall machine output speed are obtained from speed sensors n1 and n2. The gear ratio and the theoretical gear ratio of the gear to be selected are then determined. The state of the transmission mechanism is then judged. If the gear ratio changes beyond the preset error value during operation, the clutch is immediately disengaged to interrupt power.

[0025] The present invention has the following beneficial effects:

[0026] The transmission structure of this invention, combining power shift and electro-hydraulic mechanical shift, eliminates the traditional main clutch structure and motor shifting mechanism of the interval power box. Both power shift and electro-hydraulic mechanical shift are housed within the same housing, resulting in a simple and compact structure, reduced axial length, low manufacturing cost, and ease of maintenance. With 4 gears in the input shaft component, 2 gears in the auxiliary transmission shaft component, and 2 gears in the front output component, 16 forward gears can be achieved. With 4 gears in the input shaft component, 1 reverse gear in the auxiliary transmission shaft component, and 2 gears in the front output component, 8 reverse gears can be achieved. The engagement and disengagement of the fourth synchronizer controls whether the rear output component E has power output, thus controlling front-wheel drive or four-wheel drive mode. This provides more gear selection and adaptability to various terrains and operational needs. Furthermore, the power shift uses a drive structure combining electro-hydraulic proportional valves and solenoid directional valves to reduce costs while maintaining performance. The synchronizer mechanical shifting actuator is driven by a hydraulic cylinder driven by a solenoid directional valve, further reducing costs while maintaining performance. The hydraulic system has a simple structure and reduces the failure rate. In the control method of the gearbox structure combining power shift and electro-hydraulic mechanical shift of the present invention, the power shift is controlled by closed-loop adaptive control based on the speed sensor signal to achieve smooth and quick start and shift. When the gear is engaged, the speed sensor and the calculated speed ratio value are used to monitor in real time to prevent overload slippage, interrupt power to protect the clutch, and effectively protect the clutch. Attached Figure Description

[0027] Figure 1 This is a transmission principle diagram of the gearbox body in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the hydraulic system in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram illustrating the usage method of the gearbox structure combining electro-hydraulic and mechanical shifting in an embodiment of the present invention;

[0030] Explanation of reference numerals in the attached figures:

[0031] A. Input shaft; 2. Power fourth gear; 3. Power third gear; 4. Power second gear; 5. Power first gear; B. Intermediate shaft; 6. Reverse gear; 7. First gear; 8. Second gear; 9. Third gear; 10. Fourth gear; 11. Fifth gear; 12. Sixth gear; F. Idler shaft; 14. Idler; C. Secondary transmission shaft; 15. Reverse gear; 16. Mechanical first gear; 17. Mechanical second gear; 18. Eighth gear; 19. Seventh gear; 20. High gear output gear; 21. Low gear output gear; D. Front output assembly; 22. Fourth synchronizer; E. Rear output assembly; n1. First Speed ​​sensor; n2, Second speed sensor; 23, Fourth gear clutch; 24, Third gear clutch; 25, Second gear clutch; 26, First gear clutch; 27, First synchronizer; 28, Second synchronizer; 29, Third synchronizer; 30, Front drive / four-wheel drive switching gear; G, Output shaft; 31, Working oil pump; 32, Clutch anti-slip brake; 33, Accumulator; 34, Reverse gear cylinder; 35, First gear cylinder; 36, Second gear cylinder; 37, High / low gear cylinder; 38, Four-wheel drive cylinder; 39, Cooling oil pump; 40, Radiator; 41, Speed ​​measuring gear; S1, Main transmission gear position valve block; S2, Auxiliary transmission gear position valve block; S3, High / low gear position valve block; S4, Four-wheel drive valve block. Detailed Implementation

[0032] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0033] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0034] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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. Therefore, they should not be construed as limitations on the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] refer to Figure 1 , Figure 3 The transmission structure combining power shifting and electro-hydraulic mechanical shifting in this embodiment includes: a transmission body, a hydraulic system connected to the transmission body, and an electronic control system connected to the hydraulic system, wherein the transmission body includes:

[0037] Input shaft assembly, intermediate shaft assembly, auxiliary transmission shaft assembly, output shaft assembly, idler gear shaft assembly, output assembly;

[0038] The input shaft assembly includes: input shaft A, power fourth gear 2, power third gear 3, power second gear 4, and power first gear 5, fourth gear clutch 23, third gear clutch 24, second gear clutch 25, and first gear clutch 26. The engine is connected to the left side of the input shaft assembly. Power fourth gear 2, power third gear 3, power second gear 4, and power first gear 5 are loosely fitted onto input shaft A. The fourth gear clutch 23 is located between power fourth gear 2 and input shaft A. Power fourth gear 2 can be connected to and rotate synchronously with input shaft A through the fourth gear clutch 23. Power third gear 3 can be connected to and rotate synchronously with input shaft A through the third gear clutch 24. Power second gear 4 can be connected to and rotate synchronously with input shaft A through the second gear clutch 25. Power first gear 5 can be connected to and rotate synchronously with input shaft A through the first gear clutch 26. By engaging and disengaging the fourth gear clutch 23, third gear clutch 24, second gear clutch 25, and first gear clutch 26 respectively, four gear positions can be controlled.

[0039] The intermediate shaft component includes: intermediate shaft B and a reverse gear 6, a first transmission gear 7, a second transmission gear 8, a third transmission gear 9, a fourth transmission gear 10, a fifth transmission gear 11 and a sixth transmission gear 12 fixedly sleeved on intermediate shaft B. The first transmission gear 7 meshes with the fourth power gear 2, the third transmission gear 9 meshes with the third power gear 3, the fifth transmission gear 11 meshes with the second power gear 4, and the sixth transmission gear 12 meshes with the first power gear 5.

[0040] The idler shaft assembly includes: an idler shaft F and an idler wheel 14 loosely fitted on the idler shaft F, the idler wheel 14 meshing with the reverse gear 6 for transmission;

[0041] The auxiliary transmission shaft assembly includes: an auxiliary transmission shaft C, a reverse gear 15, a mechanical first gear 16, a mechanical second gear 17, an eighth transmission gear 18, a seventh transmission gear 19, a first synchronizer 27, and a second synchronizer 28. The reverse gear 15, mechanical first gear 16, and mechanical second gear 17 are loosely fitted onto the auxiliary transmission shaft C. The eighth transmission gear 18 and the seventh transmission gear 19 are fixedly fitted onto the auxiliary transmission shaft C. The first synchronizer 27 and the second synchronizer 28 are both mounted on the auxiliary transmission shaft C. The reverse gear 15 meshes with an idler gear 14 for transmission. The first gear 16 meshes with the second transmission gear 8 for transmission, the second gear 17 meshes with the fourth transmission gear 10 for transmission, and the reverse gear 15 can be connected to the auxiliary transmission shaft C via the first synchronizer 27 and rotate synchronously. The first and second gears 16 and 17 can be connected to the auxiliary transmission shaft C via the second synchronizer 28 and rotate synchronously. By shifting gears left and right using the second synchronizer 28, two gears can be controlled. Reverse gear can be shifted using the first synchronizer 27.

[0042] The output component, serving as the third-stage transmission component, includes: an output shaft G, a high-gear output gear 20, a low-gear output gear 21, and a third synchronizer 29. Both the high-gear output gear 20 and the low-gear output gear 21 are loosely fitted onto the output shaft G. The high-gear output gear 20 meshes with the eighth transmission gear 18, and the low-gear output gear 21 meshes with the seventh transmission gear 19. By shifting gears left and right using the third synchronizer 29, two gear positions can be controlled.

[0043] In this embodiment and some other embodiments, the tip circle diameters of the power fourth gear 2, power third gear 3, power second gear 4, and power first gear 5 are different; the tip circle diameters of the first transmission gear 7, second transmission gear 8, third transmission gear 9, fourth transmission gear 10, fifth transmission gear 11, and sixth transmission gear 12 are different; the tip circle diameters of the mechanical first gear 16, mechanical second gear 17, eighth transmission gear 18, and seventh transmission gear 19 are different; and the tip circle diameters of the high-gear output gear 20 and low-gear output gear 21 are different. With 4 gears in the input shaft component, 2 gears in the auxiliary transmission shaft component, and 2 gears in the front output component (D2), 4×2×2=16 forward gears can be achieved; with 4 gears in the input shaft component, 1 reverse gear in the auxiliary transmission shaft component, and 2 gears in the front output component (D2), 4×1×2=8 reverse gears can be achieved, thus meeting a wider range of terrain and operational needs.

[0044] refer to Figure 2In this embodiment and some other embodiments, the first synchronizer 27, the second synchronizer 28, the third synchronizer 29, and the fourth synchronizer 22 are connected to the AMT shifting mechanism, and the shifting action is completed by the AMT shifting mechanism. Specifically, the gearbox body also includes: a first gear cylinder 35, a second gear cylinder 36, a reverse gear cylinder 34, and a high / low gear cylinder 37. The hydraulic system includes a working oil pump 31 and a main transmission gear position valve block S1, a secondary transmission gear position valve block S2, and a high / low gear position valve block S3. The main transmission gear position valve block S1 includes an electro-hydraulic proportional directional valve K1, an electro-hydraulic proportional directional valve K2, a solenoid directional valve K3, and a solenoid directional valve K4. The secondary transmission gear position valve block S2 includes a solenoid directional valve K5, a solenoid directional valve K6, a solenoid directional valve K7, a solenoid directional valve K8, a solenoid directional valve K9, a solenoid directional valve K1, a solenoid directional valve K2, a solenoid directional valve K3, and a solenoid directional valve K4. The system includes directional valve K6, solenoid directional valve K7, and high / low gear valve block S3, which includes solenoid directional valve K9, electro-hydraulic proportional directional valve K1, and electro-hydraulic proportional directional valve K2 connected in parallel. The inlet of solenoid directional valve K4 is connected to the working oil pump 31 via electro-hydraulic proportional directional valve K2. The inlet of solenoid directional valve K3 is connected to the working oil pump 31 via electro-hydraulic proportional valve K1. The inlets of solenoid directional valves K5, K6, and K7, connected in parallel, are all connected to the working oil pump 31. The inlet of the directional valve K9 is connected to the working oil pump 31. The first gear clutch 26 and the third gear clutch 24 are respectively connected to the two working ports of the solenoid directional valve K4. The second gear clutch 25 and the fourth gear clutch 23 are respectively connected to the two working ports of the solenoid directional valve K3. The working port of the solenoid directional valve K5 is connected to the second gear cylinder 36. The working port of the solenoid directional valve K6 is connected to the first gear cylinder 35. The working port of the solenoid directional valve K7 is connected to the reverse gear cylinder. The working port of the solenoid directional valve K9 is connected to the high / low gear cylinder 37. The second gear cylinder 36 is used to push the second synchronizer 28 to engage with the mechanical first gear 16. The first gear cylinder 35 is used to push the second synchronizer 28 to engage with the mechanical second gear 17. The reverse gear cylinder 34 is used to push the first synchronizer 27 to engage with the reverse gear 15. The high / low gear cylinder 37 is used to push the third synchronizer 29 to engage with the low gear, or to push the third synchronizer 29 to engage with the high gear output gear 20. The combination of electro-hydraulic proportional directional valve K1 and solenoid directional valve K3 in the hydraulic unit controls the second and fourth gear clutches 23 to achieve the engagement of the second and fourth gears; the combination of electro-hydraulic proportional directional valve K2 and solenoid directional valve K4 in the hydraulic unit controls the first and third gear clutches 24 to achieve the engagement of the first and third gears; the solenoid directional valves K5, K6, K7, and K9 in the hydraulic unit control the engagement of the mechanical gears in the second, first, reverse, high, and low gears, respectively.

[0045] In this embodiment, the electro-hydraulic proportional directional valve K1 and the electro-hydraulic proportional directional valve K2 are two-position three-way electro-hydraulic proportional directional valves, the solenoid directional valves K3 and K4 are two-position four-way solenoid directional valves, the solenoid directional valves K5, K6, and K7 are two-position three-way solenoid directional valves, and the solenoid directional valves K8 and K9 are two-position four-way solenoid directional valves. The two chambers of the high and low gear cylinder 37 are respectively connected to the two working ports of the solenoid directional valve K9, and the two chambers of the four-wheel drive cylinder 38 are respectively connected to the two working ports of the solenoid directional valve K8.

[0046] In this embodiment, the hydraulic system adopts a drive structure combining proportional valves and on / off valves to reduce costs while ensuring performance; the synchronizer mechanical shifting actuator is driven by an electro-hydraulic valve to complete the operation of the oil cylinder, which reduces costs while ensuring performance. The hydraulic system has a simple structure and can reduce the failure rate.

[0047] In this embodiment and some other embodiments, the gearbox body also includes a four-wheel drive cylinder 38. In the gearbox body, one end of the output shaft G is fixedly connected to the front output component D, and the other end is fixedly connected to the front-wheel drive / four-wheel drive switching gear 30. The fourth synchronizer 22 is coaxially fixed and rotates synchronously with the rear output component E. The fourth synchronizer 22 is rotatably arranged coaxially with the front-wheel drive / four-wheel drive switching gear 30 and can engage with the front-wheel drive / four-wheel drive switching gear 30 and rotate synchronously. The hydraulic system includes a working oil pump 31 and a four-wheel drive valve block S4. The four-wheel drive valve block S4 includes a solenoid directional valve K8. The oil inlet of the solenoid directional valve K8 is connected to the working oil pump 31, and the working oil port is connected to the four-wheel drive cylinder 38. The four-wheel drive cylinder 38 is used to push the fourth synchronizer 22 to engage with the front-wheel drive / four-wheel drive switching gear 30. By disengaging and engaging the fourth synchronizer 22 with the front-wheel drive / four-wheel drive switching gear 30, it is possible to control whether the rear output component E has power output, that is, to control the front-wheel drive or four-wheel drive mode. The shifting actions of the first synchronizer 27, the second synchronizer 28, the third synchronizer 29, and the fourth synchronizer 22 are completed by the AMT shifting mechanism.

[0048] In this embodiment and some other embodiments, a sleeve is loosely fitted on the shaft of the fourth synchronizer 22, and the front-drive / four-wheel drive switching gear 30 rotates synchronously and circumferentially with the sleeve.

[0049] In this embodiment and some other embodiments, a pressure sensor P is installed on the oil line connecting the working oil pump 31 to the main transmission gear position valve block S1, the auxiliary transmission gear position valve block S2 and the high and low gear position valve block S3. The pressure sensor P is connected to the electronic control system.

[0050] In this embodiment and some other embodiments, a speed measuring gear 41 is also fixedly installed on the output shaft G, and a first speed sensor n1 for detecting the speed of the reverse gear 6 and a speed sensor n2 for detecting the speed of the speed measuring gear 41 are also installed in the gearbox. Both the first speed sensor n1 and the speed sensor n2 are connected to the electronic control system.

[0051] In this embodiment, the controller of the electronic control system can collect the pressure signal from pressure sensor P and the signals from speed sensors n1 and n2, and output the control signals, status information, and diagnostic information of the proportional valve and the switching valve. The power shift is controlled by closed-loop adaptive control based on the output speed and acceleration to achieve smooth and quick start and shift. When the gear is engaged, the speed sensor and the calculated speed ratio value are used to monitor in real time to prevent overload slippage and interrupt power to protect the clutch.

[0052] In this embodiment and some other embodiments, the oil in the clutches and cylinders that have stopped working in the gearbox body returns to the oil tank through the return oil circuit. The working oil pump 31 is connected to the oil tank to supply oil. The oil tank is also connected to the cooling oil pump 39, which is connected to the radiator 40. The oil returns to the oil tank after being cooled by the radiator 40.

[0053] In this embodiment and some other embodiments, the fourth gear 2, the third gear 3, the second gear 4, and the first gear 5 are all mounted on the input shaft A via bearings; the idler gear 14 is mounted on the idler shaft F via bearings; the reverse gear 15, the mechanical first gear 16, and the mechanical second gear 17 are all mounted on the auxiliary transmission shaft C via bearings; and the high-gear output gear 20 and the low-gear output gear 21 are both mounted on the output shaft G via bearings.

[0054] In this embodiment, the gearbox body also includes a clutch anti-slip brake 32, and the hydraulic system also includes an electromagnetic reversing valve K10. The working port of the electromagnetic reversing valve K10 is connected to the clutch anti-slip brake 32, and the inlet port of the electromagnetic reversing valve K10 is connected to the working oil pump 31.

[0055] refer to Figure 3 In this embodiment, the control system is used to collect speed and pressure signals from the gearbox and to control the operation of the proportional valve and switching valve of the hydraulic unit. The hydraulic system is used to control the proportional valve and switching valve to operate according to the control signals issued by the control system, and output the corresponding pressure to push the oil cylinder to achieve the corresponding gear shift.

[0056] This embodiment also discloses a control method for a gearbox structure that combines power shifting and electro-hydraulic mechanical shifting, which is applied to the aforementioned gearbox structure that combines power shifting and electro-hydraulic mechanical shifting.

[0057] Specifically, the control method for the gearbox structure combining power shifting and electro-hydraulic mechanical shifting in this embodiment includes the following steps:

[0058] When starting and shifting to power gear, first control the solenoid directional valve that switches to the corresponding gear, and then control the pressure increase process of the corresponding electro-hydraulic proportional directional valve according to the speed and acceleration changes obtained from the speed sensor.

[0059] When shifting gears using a mechanical synchronizer, first disengage the power gear clutch, then switch gears using the mechanical synchronizer. After the shift is complete, the power gear clutch engages the gear through creeping and slipping.

[0060] After shifting gears, the speed ratio and the theoretical speed ratio of the gear to be selected are obtained based on the engine speed, power gear output speed, and overall machine output speed obtained from the speed sensor. This allows the system to determine the state of the transmission mechanism. If the speed ratio changes beyond the preset error value during operation, the clutch is immediately disengaged to interrupt power.

[0061] The control method of the electronic control system in this embodiment is as follows:

[0062] 1. Starting and shifting gears: The corresponding gear switching valve is switched first, and the pressure increase process of the corresponding proportional valve is controlled in a closed loop according to the changes in speed and acceleration. The speed difference is eliminated by the clutch slippage to achieve smooth and quick starting and shifting.

[0063] 2. When shifting gears using the mechanical synchronizer, first disengage the power gear, then switch to the mechanical synchronizer. After the switch is completed, the power gear will engage through creeping and sliding friction, which helps the synchronizer to engage gears reliably and the machine to shift gears smoothly.

[0064] 3. After shifting gears, calculate the gear ratio based on the engine speed, power gear output speed, and overall machine output speed. Compare this value with the theoretical gear ratio of the gear to be selected to determine the state of the transmission mechanism. If the calculated gear ratio changes beyond the error value during operation, immediately disengage the clutch to interrupt power and effectively protect the clutch.

[0065] Specifically, the control methods for each gear in the power gear and mechanical gear are as follows:

[0066] When power gear is selected, the electro-hydraulic proportional directional valve K2 is controlled to pressurize. When the absolute value of the difference between the output speed sensor n1 and the theoretical calculation value is less than 30, the electro-hydraulic proportional directional valve K2 quickly applies working pressure current, which can reduce slippage time. If an abnormal change in speed ratio occurs after the gear is engaged, the electro-hydraulic proportional directional valve K2 is immediately disconnected to interrupt power and avoid damage to the clutch.

[0067] When the third power gear is selected, the solenoid directional valve K4 is effective, controlling the pressurization process of the electro-hydraulic proportional directional valve K2. When the absolute value of the difference between the output speed sensor n1 and the theoretical calculated value is less than 30, the electro-hydraulic proportional directional valve K2 quickly applies the working pressure current, which can reduce the slippage time. If an abnormal change in speed ratio occurs after the gear is engaged, the electro-hydraulic proportional directional valve K2 is immediately disconnected, power is interrupted, and damage to the clutch is avoided.

[0068] When selecting the second power gear, control the pressurization process of the electro-hydraulic proportional directional valve K1. When the absolute value of the difference between the output speed sensor n1 and the theoretical calculated value is less than 30, the electro-hydraulic proportional directional valve K1 quickly applies the working pressure current, which can reduce the slippage time. If an abnormal change in speed ratio occurs after the gear is engaged, immediately disconnect the electro-hydraulic proportional directional valve K1 to interrupt the power and avoid damage to the clutch.

[0069] When the fourth power gear is selected, the solenoid directional valve K3 is effective, controlling the pressurization process of the electro-hydraulic proportional directional valve K1. When the absolute value of the difference between the output speed sensor n1 and the theoretical calculated value is less than 30, the electro-hydraulic proportional directional valve K1 quickly applies the working pressure current, which can reduce the slippage time. If an abnormal change in speed ratio occurs after the gear is engaged, the electro-hydraulic proportional directional valve K1 is immediately disconnected, power is interrupted, and damage to the clutch is avoided.

[0070] When selecting mechanical first gear, first disconnect the electro-hydraulic proportional directional valve K1 or electro-hydraulic proportional directional valve K2 of the real-time power gear, open the solenoid directional valve K6, and then restore the control of the previously disconnected proportional valve. Through creep and closed-loop adaptive control pressurization, reliable gear engagement and smooth and quick gear shifting of mechanical first gear are ensured.

[0071] When selecting mechanical second gear, first disconnect the electro-hydraulic proportional directional valve K1 or electro-hydraulic proportional directional valve K2 of the real-time power gear, open the solenoid directional valve K5, and then restore the control of the previously disconnected proportional valve. Through creep and closed-loop adaptive control pressurization, reliable gear engagement and smooth and quick gear shifting of mechanical first gear are ensured.

[0072] When selecting the mechanical high gear, first disconnect the real-time power gear electro-hydraulic proportional directional valve K1 or electro-hydraulic proportional directional valve K2, open the solenoid directional valve K6, and then restore the control of the previously disconnected proportional valve. Through creep and closed-loop adaptive control pressurization, reliable gear engagement and smooth and quick gear shifting of the mechanical first gear are ensured.

[0073] When selecting the mechanical low gear, first disconnect the real-time power gear electro-hydraulic proportional directional valve K1 or K2, close the solenoid directional valve K6, and then restore the control of the previously disconnected proportional valve. Through creep and closed-loop adaptive control pressurization, reliable gear engagement and smooth and quick gear shifting of the mechanical first gear are ensured.

[0074] The front-wheel drive and four-wheel drive control method of the hydraulic system in this embodiment is as follows:

[0075] 1. Front-drive mode: When the solenoid reversing valve K8 is de-energized, the four-wheel drive cylinder 38 controls the fourth synchronizer 22 to disengage from the front-drive / four-wheel drive switching gear 30, and the rear output component EE has no power output;

[0076] II. Four-wheel drive mode: When the solenoid reversing valve K8 is energized, the four-wheel drive cylinder 38 controls the fourth synchronizer 22 to engage with the front-wheel drive / four-wheel drive switching gear 30, and the rear output component EE has power output.

[0077] The forward gear control method of the hydraulic system in this embodiment is as follows:

[0078] 1. Forward 1st gear: 1. Electro-hydraulic proportional directional valve K2 is energized, controlling the engagement of the 1st gear clutch 26; 2. Solenoid directional valve K6 is energized, controlling the 1st gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical 2nd gear 17; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21.

[0079] That is: Power input → First gear 5 → Sixth gear 12 → Fourth gear 10 → Second gear 17 → Seventh gear 19 → Low gear output 21 → Power output (front drive or four drive)

[0080] II. Forward 2nd gear: 1. Electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. Solenoid directional valve K6 is energized, controlling the first gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second gear 17; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21.

[0081] That is: Power input → Second gear 4 → Fifth gear 11 → Fourth gear 10 → Second gear 17 → Seventh gear 19 → Low gear output 21 → Power output (front drive or four drive)

[0082] III. Forward 3rd Gear 1. Electro-hydraulic proportional directional valve K2 is energized, and solenoid directional valve K4 is energized; controlling the engagement of the 3rd gear clutch 24; 2. Solenoid directional valve K6 is energized, controlling the 1st gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical 2nd gear 17; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0083] That is: Power input → Power 3rd gear 3 → Third transmission gear 9 → Fourth transmission gear 10 → Mechanical 2nd gear 17 → Seventh transmission gear 19 → Low gear output gear 21 → Power output front-wheel drive or four-wheel drive

[0084] IV. Forward 4th Gear: 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K6 is energized, controlling the first gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second gear 17; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0085] That is: Power input → Power 4th gear 2 → First transmission gear 7 → Fourth transmission gear 10 → Mechanical 2nd gear 17 → Seventh transmission gear 19 → Low gear output gear 21 → Power output front-wheel drive or four-wheel drive

[0086] V. Forward 5 gears: 1. Electro-hydraulic proportional directional valve K2 is energized, controlling the engagement of the first gear clutch 26; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21.

[0087] That is: Power input → First gear 5 → Sixth gear 12 → Second gear 8 → Mechanical first gear 16 → Seventh gear 19 → Low gear output 21 → Power output (front drive or four drive)

[0088] VI. Forward 6th gear: 1. Electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21.

[0089] That is: Power input → Second gear 4 → Fifth gear 11 → Second gear 8 → First gear 16 → Seventh gear 19 → Low gear output 21 → Power output (front drive or four drive)

[0090] VII. Forward 7th gear: 1. Electro-hydraulic proportional directional valve K2 is energized, and solenoid directional valve K4 is energized; controlling the engagement of the third gear clutch 24; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0091] Power input → Power 3rd gear 3 → Third transmission gear 9 → Second transmission gear 8 → Mechanical 1st gear 16 → Seventh transmission gear 19 → Low gear output gear 21 → Power output (front drive or four drive)

[0092] 8. Forward 8th gear: 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0093] That is: Power input → Power 4th gear 2 → First transmission gear 7 → Second transmission gear 8 → Mechanical 1st gear 16 → Seventh transmission gear 19 → Low gear output gear 21 → Power output front-wheel drive or four-wheel drive

[0094] 9. Forward 9th gear: 1. When the electro-hydraulic proportional directional valve K2 is energized, it controls the engagement of the first gear clutch 26; 2. When the solenoid directional valve K6 is energized, it controls the first gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second gear 17; 3. When the solenoid directional valve K9 is de-energized, it controls the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20.

[0095] Power input → First gear 5 → Sixth gear 12 → Fourth gear 10 → Second gear 17 → Eighth gear 18 → High gear 20 → Power output (front drive or four drive)

[0096] 10. Moving forward 10 gears: 1. The electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. The solenoid directional valve K6 is energized, controlling the first gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second gear 17; 3. The solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20.

[0097] Power input → Second gear 4 → Fifth gear 11 → Fourth gear 10 → Second gear 17 → Eighth gear 18 → High gear output 20 → Power output (front drive or four drive)

[0098] 11. Moving forward to 11th gear: 1. Electro-hydraulic proportional directional valve K2 is energized, and solenoid directional valve K4 is energized; this controls the engagement of the third-gear clutch 24; 2. Solenoid directional valve K6 is energized, controlling the first-gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second-gear gear 17; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high-gear output gear 20;

[0099] That is: Power input → Power third gear 3 → Third transmission gear 9 → Fourth transmission gear 10 → Mechanical second gear 17 → Eighth transmission gear 18 → High gear output gear 20 → Power output front-wheel drive or four-wheel drive

[0100] 12. Moving forward to 12th gear: 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K6 is energized, controlling the first gear cylinder 35 to push the second synchronizer 28 to engage with the mechanical second gear 17; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20;

[0101] That is: Power input → Power 4th gear 2 → First transmission gear 7 → Fourth transmission gear 10 → Mechanical 2nd gear 17 → Eighth transmission gear 18 → High gear output gear 20 → Power output front-wheel drive or four-wheel drive

[0102] 13. Forward 13th gear: 1. Electro-hydraulic proportional directional valve K2 is energized, controlling the first gear clutch 26 to engage; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is de-energized, controlling the high and low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20.

[0103] That is: Power input → Power first gear 5 → Sixth transmission gear 12 → Second transmission gear 8 → Mechanical first gear 16 → Eighth transmission gear 18 → High gear output gear 20 → Power output front-wheel drive or four-wheel drive

[0104] XIV. Forward 14th gear: 1. Electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is de-energized, controlling the high and low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20.

[0105] That is: Power input → Second gear 4 → Fifth gear 11 → Second gear 8 → First gear 16 → Eighth gear 18 → High gear output 20 → Power output (front drive or four drive)

[0106] 15. Moving forward to 15 gears: 1. Electro-hydraulic proportional directional valve K2 is energized, and solenoid directional valve K4 is energized; this controls the engagement of the third-gear clutch 24; 2. Solenoid directional valve K5 is energized, controlling the second-gear cylinder to push the second synchronizer 28 to engage with the mechanical first-gear gear 16; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high-gear output gear 20;

[0107] That is: Power input → Power third gear 3 → Third transmission gear 9 → Second transmission gear 8 → Mechanical first gear 16 → Eighth transmission gear 18 → High gear output gear 20 → Power output front-wheel drive or four-wheel drive

[0108] XVI. Moving forward to 16 gears: 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K5 is energized, controlling the second gear cylinder to push the second synchronizer 28 to engage with the mechanical first gear 16; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20;

[0109] That is: power input → power fourth gear 2 → first transmission gear 7 → second transmission gear 8 → mechanical first gear 16 → eighth transmission gear 18 → high gear output gear 20 → power output front drive or four drive.

[0110] The reverse gear control method of the hydraulic system in this embodiment is as follows:

[0111] 1. Reverse 1st gear: 1. Electro-hydraulic proportional directional valve K2 is energized, controlling the first gear clutch 26 to engage; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage the reverse gear 15; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage the low gear output gear 21.

[0112] That is: power input → first gear 5 → sixth transmission gear 12 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → seventh transmission gear 19 → low gear output gear 21 → power output front drive or four drive.

[0113] II. Reverse 2 gears: 1. Electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage the reverse gear 15; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage the low gear output gear 21.

[0114] That is: power input → second gear 4 → fifth transmission gear 11 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → seventh transmission gear 19 → low gear output gear 21 → power output front drive or four drive.

[0115] III. Reverse 3rd gear: 1. Electro-hydraulic proportional directional valve K2 is energized, and solenoid directional valve K4 is energized; controlling the engagement of the third gear clutch 24; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage with the reverse gear 15; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0116] That is: power input → power third gear 3 → third transmission gear 9 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → seventh transmission gear 19 → low gear output gear 21 → power output front drive or four drive.

[0117] IV. Reverse 4th gear 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage with the reverse gear 15; 3. Solenoid directional valve K9 is energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage with the low gear output gear 21;

[0118] That is: power input → power fourth gear 2 → first transmission gear 7 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → seventh transmission gear 19 → low gear output gear 21 → power output front drive or four drive.

[0119] V. Reverse 5 gears: 1. Electro-hydraulic proportional directional valve K2 is energized, controlling the first gear clutch 26 to engage; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage the reverse gear 15; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage the high gear output gear 20.

[0120] That is: power input → first gear 5 → sixth transmission gear 12 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → eighth transmission gear 18 → high gear output gear 20 → power output front drive or four drive.

[0121] VI. Reverse 6th gear 1. Electro-hydraulic proportional directional valve K1 is energized, controlling the second gear clutch 25 to engage; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage the reverse gear 15; 3. Solenoid directional valve K9 is de-energized, controlling the high and low gear cylinder 37 to push the third synchronizer 29 to engage the high gear output gear 20;

[0122] That is: power input → second gear 4 → fifth transmission gear 11 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → eighth transmission gear 18 → high gear output gear 20 → power output front drive or four drive.

[0123] VII. Reverse 7th gear 1. Electro-hydraulic proportional directional valve K2 is energized, solenoid directional valve K4 is energized; control the third gear clutch 24 to engage; 2. Solenoid directional valve K7 is energized, control the reverse gear cylinder 34 to push the first synchronizer 27 to engage with the reverse gear 15; 3. Solenoid directional valve K9 is de-energized, control the high and low gear cylinder 37 to push the third synchronizer 29 to engage with the high gear output gear 20;

[0124] That is: power input → power third gear 3 → third transmission gear 9 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → eighth transmission gear 18 → high gear output gear 20 → power output front drive or four drive.

[0125] 8. Reverse 8 gears: 1. Electro-hydraulic proportional directional valve K1 is energized, solenoid directional valve K3 is energized, controlling the engagement of the fourth gear clutch 23; 2. Solenoid directional valve K7 is energized, controlling the reverse gear cylinder 34 to push the first synchronizer 27 to engage the reverse gear 15; 3. Solenoid directional valve K9 is de-energized, controlling the high / low gear cylinder 37 to push the third synchronizer 29 to engage the high gear output gear 20;

[0126] That is: power input → power fourth gear 2 → first transmission gear 7 → reverse transmission gear 6 → idler gear 14 → reverse gear 15 → eighth transmission gear 18 → high gear output gear 20 → power output front drive or four drive.

[0127] This invention relates to a transmission structure and control method combining power shift and electro-hydraulic mechanical shift. It eliminates the main clutch series structure and proposes a transmission structure using a wet clutch and an electro-hydraulic synchronizer for shifting. The power shift employs a drive structure combining proportional valves and switching valves to reduce costs while maintaining performance. The synchronizer mechanical shifting actuator is driven by an electro-hydraulic valve pushing a cylinder, further reducing costs while maintaining performance. Based on the transmission's mechanical and hydraulic characteristics, the control system combines engine speed, main transmission power output speed, and overall transmission output speed. Through closed-loop adaptive calculation, it controls the proportional valve, achieving smooth and quick starting and shifting through the slippage of the wet clutch. After gear engagement, three speed sensors calculate the current gear and gear ratio, monitoring in real time. If abnormal slippage occurs, power is immediately cut off to protect the transmission and improve reliability. This invention achieves 16 forward gears and 8 reverse gears through electro-hydraulic power.

[0128] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A power shift and electro-hydraulic mechanically shift combined transmission structure, characterized by, The gearbox comprises a gearbox body, a hydraulic system connected with the gearbox body, and an electric control system connected with the hydraulic system. The gearbox body comprises an input shaft component, an intermediate shaft component, a sub-transmission shaft component, an output shaft component, an idler shaft component, and an output component. The input shaft component comprises an input shaft A, a power fourth gear (2), a power third gear (3), a power second gear (4), a power first gear (5), a fourth clutch (23), a third clutch (24), a second clutch (25), and a first clutch (26). The power fourth gear (2), the power third gear (3), the power second gear (4), and the power first gear (5) are sleeved on the input shaft A. The fourth clutch (23) is arranged between the power fourth gear (2) and the input shaft A. The power fourth gear (2) can be connected with the input shaft A and rotate synchronously through the fourth clutch (23). The power third gear (3) can be connected with the input shaft A and rotate synchronously through the third clutch (24). The power second gear (4) can be connected with the input shaft A and rotate synchronously through the second clutch (25). The power first gear (5) can be connected with the input shaft A and rotate synchronously through the first clutch (26). The intermediate shaft component comprises an intermediate shaft B, a reverse transmission gear (6), a first transmission gear (7), a second transmission gear (8), a third transmission gear (9), a fourth transmission gear (10), a fifth transmission gear (11), and a sixth transmission gear (12) which are fixedly sleeved on the intermediate shaft B. The first transmission gear (7) is in meshing transmission with the power fourth gear (2). The third transmission gear (9) is in meshing transmission with the power third gear (3). The fifth transmission gear (11) is in meshing transmission with the power second gear (4). The sixth transmission gear (12) is in meshing transmission with the power first gear (5). The idler shaft component comprises an idler shaft F and an idler (14) which is sleeved on the idler shaft F. The idler (14) is in meshing transmission with the reverse transmission gear (6). The sub-transmission shaft component comprises a sub-transmission shaft C, a reverse gear (15), a mechanical first gear (16), a mechanical second gear (17), an eighth transmission gear (18), a seventh transmission gear (19), a first synchronizer (27), and a second synchronizer (28). The reverse gear (15), the mechanical first gear (16), and the mechanical second gear (17) are sleeved on the sub-transmission shaft C. The eighth transmission gear (18) and the seventh transmission gear (19) are fixedly sleeved on the sub-transmission shaft C. The first synchronizer (27) and the second synchronizer (28) are installed on the sub-transmission shaft C. The reverse gear (15) is in meshing transmission with the idler (14). The mechanical first gear (16) is in meshing transmission with the second transmission gear (8). The mechanical second gear (17) is in meshing transmission with the fourth transmission gear (10). The reverse gear (15) can be connected with the sub-transmission shaft C and rotate synchronously through the first synchronizer (27). The mechanical first gear (16) and the mechanical second gear (17) can be connected with the sub-transmission shaft C and rotate synchronously through the second synchronizer (28). ​ The output component comprises an output shaft G, a high-gear output gear (20), a low-gear output gear (21) and a third synchronizer (29); the high-gear output gear (20) and the low-gear output gear (21) are both sleeved on the output shaft G, the high-gear output gear (20) is in meshing transmission with the eighth transmission gear (18), and the low-gear output gear (21) is in meshing transmission with the seventh transmission gear (19).

2. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 1, characterized in that, The tip circle diameters of the power fourth-gear gear (2), the power third-gear gear (3), the power second-gear gear (4) and the power first-gear gear (5) are different from each other, the tip circle diameters of the first transmission gear (7), the second transmission gear (8), the third transmission gear (9), the fourth transmission gear (10), the fifth transmission gear (11) and the sixth transmission gear (12) are different from each other, the tip circle diameters of the mechanical first-gear gear (16), the mechanical second-gear gear (17), the eighth transmission gear (18) and the seventh transmission gear (19) are different from each other, and the tip circle diameters of the high-gear output gear (20) and the low-gear output gear (21) are different from each other.

3. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 1, characterized in that, The gearbox body further comprises a first gear oil cylinder (35), a second gear oil cylinder (36), a reverse gear oil cylinder (34) and a high-low gear oil cylinder (37), the hydraulic system comprises a working oil pump (31) and a main gear shift valve block (S1), a secondary gear shift valve block (S2) and a high-low gear shift valve block (S3), wherein the main gear shift valve block (S1) comprises an electro-hydraulic proportional directional valve K1, an electro-hydraulic proportional directional valve K2, an electromagnetic directional valve K3 and an electromagnetic directional valve K4, the secondary gear shift valve block (S2) comprises an electromagnetic directional valve K5, an electromagnetic directional valve K6 and an electromagnetic directional valve K7, the high-low gear shift valve block (S3) comprises an electromagnetic directional valve K9, the first inlet of the electromagnetic directional valve K4 is connected with the working oil pump (31), the second inlet of the electromagnetic directional valve K4 is connected with the working oil pump (31) through the electro-hydraulic proportional directional valve K2, the first inlet of the electromagnetic directional valve K3 is connected with the working oil pump (31), the second inlet of the electromagnetic directional valve K4 is connected with the working oil pump (31) through the electro-hydraulic proportional directional valve K1, the inlets of the electromagnetic directional valves K5, K6, K7 and K9 are connected with the working oil pump (31), the first gear clutch (26) and the third gear clutch (24) are respectively connected with two working oil ports of the electromagnetic directional valve K4, the second gear clutch (25) and the fourth gear clutch (23) are respectively connected with two working oil ports of the electromagnetic directional valve K3, the working oil port of the electromagnetic directional valve K5 is connected with the second gear oil cylinder (36), the working oil port of the electromagnetic directional valve K6 is connected with the first gear oil cylinder (35), the working oil port of the electromagnetic directional valve K7 is connected with the reverse gear oil cylinder, the working oil port of the electromagnetic directional valve K9 is connected with the high-low gear oil cylinder (37), the second gear oil cylinder (36) is used to push the second synchronizer (28) to combine with the mechanical first gear (16), the first gear oil cylinder (35) is used to push the second synchronizer (28) to combine with the mechanical second gear (17), the reverse gear oil cylinder (34) is used to push the first synchronizer (27) to combine with the reverse gear (15), and the high-low gear oil cylinder (37) is used to push the third synchronizer (29) to combine with the low gear or to combine with the high gear output gear (20).

4. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 3, characterized in that, The gearbox body further comprises a four-wheel drive oil cylinder (38), in the gearbox body, one end of an output shaft G is fixedly connected with a front output component (D), the other end is fixedly connected with a front drive / four-wheel drive switching gear (30), a fourth synchronizer (22) is coaxially fixedly and synchronously rotated with a rear output component (E), the fourth synchronizer (22) is coaxially arranged with the front drive / four-wheel drive switching gear (30) in a rotatable manner, and the fourth synchronizer (22) can combine with and synchronously rotate with the front drive / four-wheel drive switching gear (30); the hydraulic system comprises a working oil pump (31) and a four-wheel drive valve block (S4), the four-wheel drive valve block (S4) comprises an electromagnetic directional valve K8, the inlet of the electromagnetic directional valve K8 is connected with the working oil pump (31), and the working oil port is connected with the four-wheel drive oil cylinder (38), the four-wheel drive oil cylinder (38) is used to push the fourth synchronizer (22) to combine with the front drive / four-wheel drive switching gear (30).

5. A power shift and electrically controlled hydraulic mechanical shift combination gearbox structure according to claim 4, characterized in that, The fourth synchronizer (22) is sleeved with a shaft cylinder on the shaft, and the front drive / four-wheel drive switching gear (30) is fixedly and synchronously rotated with the shaft cylinder.

6. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 3, characterized in that, The working oil pump (31) is provided with a pressure sensor P on an oil passage communicated with the main gear shifting valve block (S1), the auxiliary gear shifting valve block (S2) and the high / low gear shifting valve block (S3), and the pressure sensor P is connected with the electronic control system.

7. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 3, characterized in that, The output shaft G is further fixedly provided with a speed measuring gear, the transmission case is further provided with a speed sensor n1 for detecting the speed of the reverse gear driving gear (6) and a speed sensor n2 for detecting the speed of the speed measuring gear, and the speed sensor n1 and the speed sensor n2 are connected with the electronic control system.

8. The power shift and electrically controlled hydraulic mechanical shift combined transmission structure according to claim 3, characterized in that, The oil in the clutches and the oil cylinder which stop working in the transmission case body is returned to the oil tank through an oil return oil passage, the working oil pump (31) is communicated with the oil tank for oil supply, the oil tank is further communicated with a heat dissipation oil pump (39), the heat dissipation oil pump (39) is connected with a radiator (40), and the oil is returned to the oil tank after being heat dissipated by the radiator (40).

9. A control method of a transmission structure combining a power shift and an electrically controlled hydraulic mechanical shift, characterized by, The application is applied to the transmission case structure as claimed in claim 1.

10. The control method of the power shift and electrically controlled hydraulic mechanical shift combination type transmission structure according to claim 9, characterized by, The application comprises the following steps: During starting and power gear shifting, the electromagnetic reversing valve corresponding to the gear is controlled first, and the pressure increasing process of the corresponding electro-hydraulic proportional reversing valve is controlled according to the speed and acceleration change obtained by the speed sensor; During mechanical gear synchronizer shifting, the power gear clutch is first disengaged, and then the mechanical synchronizer gear is switched, and after completion, the power gear clutch is engaged through peristalsis and sliding friction; After the gear is engaged, the speed ratio and the theoretical speed ratio value of the selected gear are obtained according to the engine speed, the power gear output speed and the whole machine output speed obtained by the speed sensor, so as to judge the state of the transmission mechanism, and if the speed ratio value changes more than the preset error value during work, the clutch is immediately disengaged to interrupt the power.

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