A power switching and cooling control device and method for a special vehicle amphibious transfer case

Abstract

The invention discloses a power switching and cooling control device and method for a special vehicle amphibious transfer case, comprising a clutch, a hydraulic device and an electronic control unit; the active part and the driven part of the clutch are both provided with a speed sensor, and a pressure sensor is provided inside the clutch housing; the hydraulic device comprises an oil tank, a coarse filter, a variable pump, a fine filter, a reversing valve, a solenoid valve, an overflow valve, a lubrication direction control valve, a one-way valve, a land radiator, a water radiator and a throttle hole; the variable pump, the solenoid valve, the speed sensor and the pressure sensor are respectively connected to the electronic control unit; the invention has a simple structure, controls the switching of the cooling oil circuit by controlling the hydraulic oil circuit of the power switching, ensures the effective operation of the hydraulic oil under various working conditions; timely compensates for the hydraulic oil pressure difference at both ends of the clutch, shortens the relative sliding time of the active and driven parts thereof, improves the long-term working reliability of the clutch, and optimizes the power switching and cooling performance of the amphibious transfer case.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to a control device and method for power switching and cooling of an amphibious transfer case of a special vehicle. Background Art

[0002] Special vehicles need to be able to switch between driving on land and water, and need to have two power outputs: wheel output for land conditions and propeller output for water conditions. Therefore, an amphibious transfer case is needed that can selectively or simultaneously transmit engine power to wheels or propellers. The amphibious transfer case that uses a clutch to switch power does not require manual operation, which greatly relieves the driver's driving fatigue.

[0003] At the same time, due to the different driving environments of vehicles on land and on water, the heat generated by the two working conditions is very different. One set of cooling device cannot adapt well to the heat generated by its work. Therefore, special vehicles need to have two sets of cooling devices to cool the hydraulic oil, one for each of the two main driving conditions.

[0004] The hydraulic oil used for lubrication, cooling, clutch control, etc. comes from the same oil source. Long-term driving can easily cause the polluted particles in the hydraulic oil to be suspended and enter the hydraulic valve, clutch, etc. through the hydraulic oil, aggravating the wear of friction pairs such as hydraulic valves and clutches in the form of erosion, fatigue wear, etc. The hydraulic oil pressure when the clutch is engaged cannot reach the target engagement pressure of the clutch, resulting in prolonged engagement time, aggravating excessive friction heat generated by the clutch friction pair and further damaging the clutch.

[0005] Therefore, a highly reliable, highly integrated, simple control device and method for power switching and cooling of a special vehicle amphibious transfer case is indispensable. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a control device and method for power switching and cooling of a special vehicle amphibious transfer case with a simple structure and high reliability. By reliably controlling the engagement and disengagement of the amphibious transfer case clutch and changing the working mode of the cooling device, the performance and reliability of the amphibious transfer case are improved.

[0007] The technical solution of the present invention to solve the above technical problems is:

[0008] A method for power switching and cooling of a special vehicle amphibious transfer case is implemented by using a control device for power switching and cooling of a special vehicle amphibious transfer case. The control device for power switching and cooling of a special vehicle amphibious transfer case includes a clutch, a hydraulic device and an electronic control unit; a speed sensor I and a speed sensor II are respectively installed on the active part and the driven part of the land clutch G, a speed sensor III is installed on the driven part of the water clutch L, and a pressure sensor I and a pressure sensor II are respectively installed inside the housings of the land clutch G and the water clutch L; the hydraulic device includes an oil tank, a coarse filter, a variable pump, a fine filter, a reversing valve I, a reversing valve II, a solenoid valve III, a solenoid valve IV, an overflow valve, a lubrication direction control valve, a check valve, a land radiator, and a water radiator. Heater, throttle hole K and throttle hole J; in the hydraulic device: the oil tank is connected to the coarse filter, the variable pump, and the fine filter in sequence to establish a main oil circuit, and the main oil circuit is divided into two hydraulic oil branches AA and BB. The hydraulic oil branch AA is respectively connected to the A2 port of the reversing valve I, the B1 port of the solenoid valve III, the C2 port of the reversing valve II, and the D1 port of the solenoid valve IV. The B3 port of the solenoid valve III is connected to the throttle hole J and the A5 port of the reversing valve I in sequence. The A3 port of the reversing valve I is connected to the G1 port of the charging and discharging oil of the land clutch G. The D3 port of the solenoid valve IV is connected to the throttle hole K and the C5 port of the reversing valve II in sequence. The C3 port of the reversing valve II is simultaneously connected to the H1 port of the charging and discharging oil of the water clutch H, the L1 port of the charging and discharging oil of the water clutch L, and the E5 port of the lubrication directional control valve. The hydraulic oil branch BB is connected to the F1 port of the relief valve, the F2 port of the relief valve is connected to the E1 port of the lubrication directional control valve, and the F2 port of the relief valve is also connected to the check valve and the oil tank in sequence, the E3 port of the lubrication directional control valve is connected to the land radiator and the oil tank in sequence, and the E4 port of the lubrication directional control valve is connected to the water radiator and the oil tank in sequence; the variable pump, solenoid valve III, solenoid valve IV, speed sensor I, speed sensor II, speed sensor III, pressure sensor I, and pressure sensor II are connected to the electronic control unit respectively;

[0009] The specific operation of the power switching and cooling method of the amphibious transfer case of special vehicles is as follows:

[0010] A. When a special vehicle switches from a parking condition to a starting condition, the steps are as follows:

[0011] (1) The electronic control unit receives an instruction to switch from a parking condition to a starting condition;

[0012] (2) The hydraulic device starts working: The electronic control unit controls the variable pump to start working. The hydraulic oil in the oil tank passes through the coarse filter, variable pump, fine filter, overflow valve, E1 and E3 ports of the lubrication directional control valve, and the onshore radiator in turn and returns to the oil tank.

[0013] B. When a special vehicle is switched from the starting condition to the land condition, the steps are as follows:

[0014] (1) The electronic control unit receives an instruction to switch from the start-up operating condition to the onshore operating condition;

[0015] (2) Engagement of the land clutch G: An initial pressure is generated by the hydraulic oil branch AA, and the electronic control unit controls the solenoid valve III to be in the left working state. At this time, the hydraulic oil of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J, and A5 port of the reversing valve I in turn, so that the reversing valve I is in the right working state. A part of the hydraulic oil of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I and the G1 port of the land clutch G in turn, pushing the active part and the driven part of the land clutch G to start engaging until it is completed; at the same time, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in turn, lubricates the E1 and E3 ports of the directional control valve, and is cooled by the land radiator. The cooled hydraulic oil flows back to the oil tank;

[0016] When the active part and the driven part of the land clutch G are engaged, the electronic control unit measures the operating oil pressure value of the land clutch G in real time through the pressure sensor Ⅰ. The electronic control unit measures the speed of the active part and the driven part of the land clutch G in real time through the speed sensor Ⅰ and the speed sensor Ⅱ respectively and converts them into angular velocity, and calculates the transmission slip work Q during the engagement process of the land clutch G in real time. When the calculated slip work Q is greater than the target slip work Q1, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G until the engagement is completed, and avoids clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0017]

[0018] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c -- angular velocity of the clutch active part and driven part, rad / s; i1--speed ratio between the clutch driven part and the wheel; J t --Moment of inertia of clutch driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0019] C. When a special vehicle is converted from land operation to water operation, the steps are as follows:

[0020] (1) The electronic control unit receives a command to switch from the land working condition to the water and land working condition, and the land clutch G continues to be engaged;

[0021] (2) The water clutch H and the water clutch L are engaged: The electronic control unit controls the solenoid valve IV to be in the left working state. At this time, the hydraulic oil of part of the hydraulic oil branch AA passes through the D1 port, the D3 port, the throttle hole K, and the C5 port of the reversing valve II in sequence, so that the reversing valve II is in the right working state. After the hydraulic oil of part of the hydraulic oil branch AA passes through the C2 and C3 ports of the reversing valve II, it is divided into three paths and enters the H1 port of the water clutch H, the L1 port of the water clutch L, and the E5 port of the lubrication directional control valve at the same time, pushing the active part and the driven part of the water clutch H and the water clutch L to start engaging until completion, and making the lubrication directional control valve in the left working state. Then, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in turn, lubricates the E1 and E4 ports of the directional control valve, and is cooled by the water radiator. The cooled hydraulic oil flows back to the oil tank; while the active and driven parts of the water clutch H and the water clutch L are engaged, the electronic control unit measures the operating oil pressure value of the clutch L in real time through the pressure sensor Ⅱ, and the electronic control unit measures the speed of the active part of the land clutch G and the driven part of the water clutch L in real time through the speed sensor Ⅰ and the speed sensor Ⅲ respectively and converts them into angular velocity, and calculates the transmission slip work Q of the engagement process of the water clutch L in real time. When the calculated slip work Q is greater than the target slip work Q2, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the H1 and L1 ports, accelerates the engagement speed of the active and driven parts of the water clutch H and the water clutch L until the engagement of the water clutch H and the water clutch L is completed, avoiding clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0022]

[0023] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c -- angular velocity of the clutch active part and driven part, rad / s; i2--speed ratio between the clutch driven part and the propeller; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0024] D. When a special vehicle is converted from land-based working conditions to water-based working conditions, the steps are as follows:

[0025] (1) The electronic control unit receives a command to switch from the amphibious working condition to the water working condition, and the water clutch H and the water clutch L continue to be engaged;

[0026] (2) Disconnection of land clutch G: The electronic control unit controls the solenoid valve III to be in the right working state, and a part of the hydraulic oil flows from the A5 port of the reversing valve I, through the throttle hole J, the B3 port and the B2 port of the solenoid valve III, and returns to the oil tank. In this way, the reversing valve I is in the left working state due to the spring force, and the hydraulic oil in the land clutch G flows from the G1 port through the A3 port and the A1 port of the reversing valve I, and returns to the oil tank;

[0027] E. When a special vehicle is converted from water working condition to land working condition, the steps are as follows:

[0028] (1) The electronic control unit receives a command to switch from the water working condition to the land working condition, and the water clutch H and the water clutch L continue to be engaged;

[0029] (2) Engagement of land clutch G: The electronic control unit controls the solenoid valve III to be in the left working state. At this time, the hydraulic oil of part of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J, and A5 port of the reversing valve I of the solenoid valve III in turn, so that the reversing valve I is in the right working state. The hydraulic oil of part of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I and the G1 port of the land clutch G in turn, pushing the active part and the driven part of the land clutch G to start engaging until it is completed; at the same time, the hydraulic oil flowing through the E5 port puts the lubrication directional control valve in the left working state, and the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in turn, the E1 and E4 ports of the lubrication directional control valve, and the water radiator is cooled. The cooled hydraulic oil flows back to the oil tank;

[0030] When the active part and the driven part of the land clutch G are engaged, the electronic control unit measures the operating oil pressure value of the land clutch G in real time through the pressure sensor Ⅰ. The electronic control unit measures the speed of the active part and the driven part of the land clutch G in real time through the speed sensor Ⅰ and the speed sensor Ⅱ respectively and converts them into angular velocity, and calculates the transmission slip work Q of the engagement process of the land clutch G in real time. When the calculated slip work Q is greater than the target slip work Q1, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G until the engagement is completed, and avoids clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0031]

[0032] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c-- angular velocity of the clutch active part and driven part, rad / s; i1--speed ratio between the clutch driven part and the wheel; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0033] F. When a special vehicle is converted from water-land operation to land operation, the steps are as follows:

[0034] (1) The electronic control unit receives a command to switch from the water-land working condition to the land working condition, and the land clutch G continues to be engaged;

[0035] (2) The water clutch H and the water clutch L are disconnected: the electronic control unit puts the solenoid valve IV in the right working state, and a part of the hydraulic oil flows from the C5 port of the reversing valve II, through the throttle hole K, the D3 port and the D2 port of the solenoid valve IV, and returns to the oil tank. In this way, the reversing valve II is in the left working state due to the action of the spring force, and the hydraulic oil of the water clutch H, the water clutch L, and the lubrication directional control valve flows out from the H1 port, the L1 port and the E5 port respectively and is collected, and then flows through the C3 port and the C1 port of the reversing valve II in turn, and then returns to the oil tank. At this time, the lubrication directional control valve is in the right working state due to the spring force; the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve, the E1 and E3 ports of the lubrication directional control valve in turn, and is cooled by the onshore radiator. The cooled hydraulic oil flows back to the oil tank;

[0036] G. When a special vehicle is switched from the land-based operating condition to the starting operating condition, the steps are as follows:

[0037] (1) The electronic control unit receives an instruction to switch from the onshore operating condition to the starting operating condition;

[0038] (2) Disconnection of land clutch G: The electronic control unit makes the solenoid valve III in the right working state, and part of the hydraulic oil returns to the oil tank from the A5 port of the reversing valve I through the throttle hole J, the B3 port and the B2 port of the solenoid valve III. In this way, the reversing valve I is in the left working state due to the spring force, and the hydraulic oil in the land clutch G returns to the oil tank from the G1 port through the A3 port and the A1 port of the reversing valve I in turn;

[0039] H. When a special vehicle switches from a starting condition to a parking condition, the steps are as follows:

[0040] (1) The electronic control unit receives an instruction to switch from a starting condition to a parking condition;

[0041] (2) The hydraulic device stops working: the hydraulic oil does not flow continuously and accumulates in the oil tank 1.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The dedicated cooling circuit of the power switching and cooling control device for the special vehicle amphibious transfer case of the present invention is simple in device, and the switching of the working condition of the cooling circuit is controlled by the hydraulic oil circuit of the power switching, thereby ensuring the normal switching of the working condition of the cooling circuit, ensuring that the working temperature of the hydraulic oil is at a stable temperature under different working conditions, and avoiding the influence of the working of the hydraulic element due to excessive or low oil temperature;

[0044] The control method for power switching and cooling of the amphibious transfer case of a special vehicle of the present invention optimizes the relative sliding time of the active part and the driven part by accurately controlling and timely compensating the hydraulic oil pressure difference at both ends of the clutch, stably controls the clutch working for a long time, effectively solves the driving smoothness, and improves the performance and reliability of the amphibious transfer case. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a hydraulic principle diagram of the power switching and cooling control device of the amphibious transfer case of a special vehicle of the present invention;

[0046] Figure 2 It is a flow chart of the power switching and cooling control method of the amphibious transfer case of a special vehicle of the present invention.

[0047] Figure 1 Middle: 1. Oil tank, 2. Coarse filter, 3. Variable pump, 4. Fine filter, 5. Pressure sensor I, 6. Speed ​​sensor I, 7. Speed ​​sensor II, 8. Reversing valve I, 9. Solenoid valve III, 10. Pressure sensor II, 11. Speed ​​sensor III, 12. Reversing valve II, 13. Solenoid valve IV, 14. Electronic control unit, 15. Overflow valve, 16. Lubrication directional control valve, 17. Check valve, 18. Onshore radiator, 19. Onshore radiator, 20. Onshore clutch G, 21. Onshore clutch H, 22. Onshore clutch L, 23. Throttle hole J, 24. Throttle hole K; DETAILED DESCRIPTION

[0048] The present invention will be further described below in conjunction with the accompanying drawings.

[0049] like Figure 1As shown, the water-land transfer case power switching and cooling electro-hydraulic control device of the present invention includes a land clutch G20, a water clutch H21, a water clutch L22, a hydraulic device and an electronic control unit 14; the active part and the driven part of the land clutch G20 are respectively equipped with a speed sensor I6 and a speed sensor II7, and the driven part of the water clutch L22 is equipped with a speed sensor III11, and the housings of the land clutch G20 and the water clutch L22 are respectively equipped with a pressure sensor I5 and a pressure sensor II10; the hydraulic device includes an oil tank 1, a coarse filter 2, a variable pump 3, a fine filter 4, a reversing valve I8, a reversing valve II12, a solenoid valve III9, a solenoid valve IV13, an overflow valve 15, a lubrication direction control valve 16, a check valve 17, a land radiator 18, and a water radiator 1 9, throttle hole J23 and throttle hole K24; the oil tank 1 is connected to the coarse filter 2, the variable pump 3, and the fine filter 4 in sequence to establish the main oil circuit, and the main oil circuit is divided into two hydraulic oil branches AA and BB in sequence. The hydraulic oil branch AA is respectively connected to the A2 port of the reversing valve Ⅰ8, the B1 port of the solenoid valve Ⅲ9, the C2 port of the reversing valve Ⅱ12, and the D1 port of the solenoid valve Ⅳ13. The B3 port of the solenoid valve Ⅲ9 is connected to the throttle hole J23 and the A5 port of the reversing valve Ⅰ8 in sequence. The A3 port of the reversing valve Ⅰ8 is connected to the charging and discharging oil G1 port of the land clutch G20. The D3 port of the solenoid valve Ⅳ13 is connected to the throttle hole K24 and the C5 port of the reversing valve Ⅱ12 in sequence. The C3 port of the reversing valve Ⅱ12 is simultaneously connected to the H1 port of the water clutch H21, the L1 port of the water clutch L22, and the E5 port of the lubrication directional control valve 16. The hydraulic oil branch BB is connected to the F1 port of the relief valve 15, and the F2 port of the relief valve 15 is connected to the E1 port of the lubrication directional control valve 16. At the same time, the F2 port of the relief valve 15 is also connected to the check valve 17 and the oil tank 1 in sequence. The E3 port of the lubrication directional control valve 16 is connected to the land radiator 18 and the oil tank 1 in sequence, and the E4 port of the lubrication directional control valve 16 is connected to the water radiator 19 and the oil tank 1 in sequence. The check valve 17 ensures the minimum oil pressure in the cooling circuit, ensures that the hydraulic oil enters the water radiator or the land radiator from the E1 port of the lubrication directional control valve 16, and also prevents the hydraulic oil flowing out of the radiator from flowing back into the radiator, ensuring reliable operation.The function of the throttle hole K24 and the throttle hole J23 is to reduce the flow rate of the hydraulic oil, so that the pressure of the hydraulic oil rises relatively slowly, delays the speed of the clutch engagement process, and improves the smoothness of the gear shift; the variable pump 3, the solenoid valve III9, the solenoid valve IV13, the speed sensor I6, the speed sensor II7, the speed sensor III11, the pressure sensor I5, and the pressure sensor II10 are respectively connected to the electronic control unit 14; the electronic control unit 14 can collect the speed of the active part of the land clutch G20 in real time through the speed sensor I6, the speed sensor II7 and the speed sensor III11 can collect the speed of the driven part of the land clutch G20 and the speed of the driven part of the water clutch L22 in real time, and the pressure sensor I5 and the pressure sensor II10 can collect the operating oil pressure of the land clutch G20 and the water clutch L22. The speed of the active part and the driven part of the water clutch H21 are consistent with the active part and the driven part of the water clutch L22, and the operating oil pressure of the two clutches is also the same, so it is only necessary to measure the speed of the driven part of the water clutch L22 and the operating oil pressure of the water clutch L22. The speed of the active part of the land clutch G20 is the same as the speed of the active parts of the two water clutches H21 and L22, so the speed sensor is not installed on the active part of the water clutch, and the speed of the active parts of the two water clutches can be obtained by measuring the speed of the active part of the land clutch G20, and the active part of the land clutch G20 also operates under water conditions.

[0050] like Figure 2 The control method for power switching and cooling of a special vehicle amphibious transfer case shown in the figure is specifically operated as follows:

[0051] A. When a special vehicle switches from a parking condition to a starting condition, the steps are as follows:

[0052] (1) The electronic control unit 14 receives an instruction to switch from a parking condition to a starting condition;

[0053] (2) The hydraulic device starts working: the electronic control unit 14 controls the variable pump 3 to start working, and the hydraulic oil in the oil tank 1 passes through the coarse filter 2, the variable pump 3, the fine filter 4, the relief valve 15, the E1 and E3 ports of the lubrication directional control valve 16, the onshore radiator 18, and the oil tank 1 in sequence.

[0054] B. When a special vehicle is switched from the starting condition to the land condition, the steps are as follows:

[0055] (1) The electronic control unit 14 receives an instruction to switch from the startup operating condition to the onshore operating condition;

[0056] (2) The land clutch G20 is engaged: an initial pressure is generated by the hydraulic oil branch AA, and the electronic control unit 14 controls the solenoid valve III9 to be in the left working state. At this time, the hydraulic oil of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J23, and A5 port of the reversing valve I8 of the solenoid valve III9 in turn, so that the reversing valve I8 is in the right working state. A part of the hydraulic oil of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I8 and the G1 port of the land clutch G20 in turn, so that the active part and the driven part of the land clutch G20 begin to engage until completion; at the same time, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve 15, the E1 and E3 ports of the lubricating direction control valve 16, and the land radiator 18 for cooling. The cooled hydraulic oil flows back to the oil tank 1;

[0057] When the active part and the driven part of the land clutch G20 are engaged, the electronic control unit 14 measures the operating oil pressure value of the land clutch G20 in real time through the pressure sensor Ⅰ5. The electronic control unit 14 measures the speed of the active part and the driven part of the land clutch G20 in real time through the speed sensor Ⅰ6 and the speed sensor Ⅱ7 respectively and converts them into angular velocity, and calculates the transmission slip work Q of the engagement process of the land clutch G20 in real time. When the calculated slip work Q is greater than the target slip work Q1, the electronic control unit 14 controls the variable pump 3 to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G20 until the engagement is completed, and avoids clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0058]

[0059] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c -- angular velocity of the clutch active part and driven part, rad / s; i1--speed ratio between the clutch driven part and the wheel; J t --Moment of inertia of clutch driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0060] C. When a special vehicle is converted from land operation to water operation, the steps are as follows:

[0061] (1) The electronic control unit 14 receives a command to switch from the land working condition to the water and land working condition, and the land clutch G20 continues to be engaged;

[0062] (2) Engagement of water clutches H21 and L22: The electronic control unit 14 controls the solenoid valve IV13 to be in the left working state. At this time, the hydraulic oil of part of the hydraulic oil branch AA passes through the D1 port, D3 port, throttle hole K24, and C5 port of the reversing valve II12 of the solenoid valve IV13 in turn, so that the reversing valve II12 is in the right working state. After passing through the C2 and C3 ports of the reversing valve II12, the hydraulic oil of part of the hydraulic oil branch AA enters the H1 port of the water clutch H21, the L1 port of the water clutch L22, and the E5 port of the lubricating direction control valve 16 in three ways at the same time, pushing the active part and the driven part of the water clutch H21 and the water clutch L22 to start engaging until completion, and making the lubricating direction control valve 16 in the left working state. Then, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve 15 in turn, the E1 and E4 ports of the lubricating direction control valve 16, and the water radiator 19 for cooling. The cooled hydraulic oil flows back to the oil tank 1;

[0063] When the active and driven parts of the water clutch H21 and the water clutch L22 are engaged, the electronic control unit 14 measures the operating oil pressure value of the water clutch L22 in real time through the pressure sensor II10. The electronic control unit 14 measures the speed of the active and driven parts of the water clutch L22 in real time through the speed sensor I6 and the speed sensor III11, respectively, and converts them into angular velocity, and calculates the transmission slip work Q of the engagement process of the water clutch L22 in real time. When the calculated slip work Q is greater than the target slip work Q2, the electronic control unit 14 controls the variable pump 3 to increase the flow of hydraulic oil entering the H1 and L1 ports of the water clutch H21 and the water clutch L22, respectively, to accelerate the engagement speed of the active and driven parts of the clutches H21 and L22, and avoid clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0064]

[0065] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c -- angular velocity of the clutch active part and driven part, rad / s; i2--speed ratio between the clutch driven part and the propeller; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0066] D. When a special vehicle is converted from land-based working conditions to water-based working conditions, the steps are as follows:

[0067] (1) The electronic control unit 14 receives a command to switch from the land-water working condition to the water-water working condition, and the water clutches H21 and L22 continue to be engaged;

[0068] (2) The land clutch G20 is disconnected: the electronic control unit 14 controls the solenoid valve III9 to be in the right working state, and a part of the hydraulic oil flows from the A5 port of the reversing valve I8 through the throttle hole J23, the B3 port and the B2 port of the solenoid valve III9, and returns to the oil tank 1. In this way, the reversing valve I8 is in the left working state due to the spring force, and the hydraulic oil in the land clutch G20 flows from the G1 port through the A3 port and the A1 port of the reversing valve I8, and returns to the oil tank;

[0069] E. When a special vehicle is converted from water working condition to land working condition, the steps are as follows:

[0070] (1) The electronic control unit 14 receives an instruction to switch from the water working state to the land working state, and the water clutch H and the water clutch L continue to be engaged;

[0071] (2) The land clutch G20 is engaged: the electronic control unit 14 controls the solenoid valve III9 to be in the left working state. At this time, the hydraulic oil of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J23, and A5 port of the reversing valve I8 of the solenoid valve III9 in turn, so that the reversing valve I8 is in the right working state. A part of the hydraulic oil of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I8 and the G1 port of the land clutch G20 in turn, pushing the active part and the driven part of the land clutch G20 to start engaging until it is completed; at the same time, the hydraulic oil flowing through the E5 port makes the lubrication directional control valve 16 in the left working state, and the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve 15, the E1 and E4 ports of the lubrication directional control valve 16 in turn, and the water radiator 19 is cooled, and the cooled hydraulic oil flows back to the oil tank 1;

[0072] When the active part and the driven part of the land clutch G20 are engaged, the electronic control unit 14 measures the operating oil pressure value of the land clutch G20 in real time through the pressure sensor Ⅰ5. The electronic control unit 14 measures the speed of the active part and the driven part of the clutch G20 in real time through the speed sensor Ⅰ6 and the speed sensor Ⅱ7 respectively and converts them into angular velocity, and calculates the transmission slip work Q of the clutch G20 engagement process in real time. When the calculated slip work Q is greater than the target slip work Q1, the electronic control unit 14 controls the variable pump 3 to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G20 until the engagement is completed, and avoids clutch plate ablation caused by excessive slip work. The calculation formula of slip work Q is as follows:

[0073]

[0074] Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, s; P--clutch operating oil pressure, MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c -- angular velocity of the clutch active part and driven part, rad / s; i1--speed ratio between the clutch driven part and the wheel; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, kg·m 2 ;

[0075] F. When a special vehicle is converted from water-land operation to land operation, the steps are as follows:

[0076] (1) The electronic control unit 14 receives a command to switch from the water-land working condition to the land working condition, and the land clutch G20 continues to be engaged;

[0077] (2) The water clutch H21 and L22 are disconnected: the electronic control unit 14 makes the solenoid valve IV13 in the right working state, and a part of the hydraulic oil flows from the C5 port of the reversing valve II12, through the throttle hole K24, the D3 port and the D2 port of the solenoid valve IV13, and returns to the oil tank 1. In this way, the reversing valve II12 is in the left working state due to the spring force, and the hydraulic oil of the water clutch H21, L22 and the lubricating directional control valve 16 flows out from the H1 port, the L1 port and the E5 port respectively and then flows through the C3 port and the C1 port of the reversing valve II12 in turn, and then returns to the oil tank. At this time, the lubricating directional control valve 16 is in the right working state due to the spring force; the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve 15, the E1 and E3 ports of the lubricating directional control valve 16, and the land radiator 18 for cooling, and the cooled hydraulic oil flows back to the oil tank 1.

[0078] G. When a special vehicle is switched from the land-based operating condition to the starting operating condition, the steps are as follows:

[0079] (1) The electronic control unit 14 receives an instruction to switch from the on-land operating condition to the starting operating condition;

[0080] (2) The land clutch G20 is disconnected: the electronic control unit 14 makes the solenoid valve III9 in the right working state, and a part of the hydraulic oil returns to the oil tank 1 from the A5 port of the reversing valve I8 through the throttle hole J23, the B3 port and the B2 port of the solenoid valve III9. In this way, the reversing valve I8 is in the left working state due to the spring force, and the hydraulic oil in the land clutch G20 returns to the oil tank from the G1 port through the A3 port and the A1 port of the reversing valve I8 in turn;

[0081] H. When a special vehicle switches from a starting condition to a parking condition, the steps are as follows:

[0082] (1) The electronic control unit 14 receives an instruction to switch from the starting state to the parking state;

[0083] (2) The hydraulic device stops working: the hydraulic oil does not flow continuously and accumulates in the oil tank 1.

Claims

1. A control device for power switching and cooling of a special vehicle amphibious transfer case, characterized in that: The control device includes a land clutch G, a water clutch H, a water clutch L, a hydraulic device and an electronic control unit; The driving part and the driven part of the land clutch G are respectively equipped with a speed sensor I and a speed sensor II; A speed sensor III is installed on the driven part of the water clutch L, and a pressure sensor I and a pressure sensor II are installed inside the housings of the land clutch G and the water clutch L, respectively; The hydraulic device includes an oil tank, a coarse filter, a variable pump, a fine filter, a reversing valve I, a reversing valve II, a solenoid valve III, a solenoid valve IV, a relief valve, a lubrication direction control valve, a check valve, an onshore radiator, an onshore radiator, a throttle hole K and a throttle hole J; the oil tank is connected to the coarse filter, the variable pump and the fine filter in sequence to form a main oil circuit, the main oil circuit is divided into a hydraulic oil branch AA and a hydraulic oil branch BB, the hydraulic oil branch AA is respectively connected to the A2 port of the reversing valve I, the B1 port of the solenoid valve III, the C2 port of the reversing valve II and the D1 port of the solenoid valve IV, the B3 port of the solenoid valve III is connected to the throttle hole J and the A5 port of the reversing valve I in sequence, the A3 port of the reversing valve I is connected to the charging and discharging oil G1 port of the onshore clutch G, the D3 port of the solenoid valve IV is connected to the throttle hole K, The C5 port of the reversing valve II is connected, and the C3 port of the reversing valve II is connected to the H1 port of the water clutch H for charging and discharging oil, the L1 port of the water clutch L for charging and discharging oil, and the E5 port of the lubrication directional control valve respectively; the hydraulic oil branch BB is connected to the F1 port of the relief valve, and the F2 port of the relief valve is connected to the E1 port of the lubrication directional control valve. At the same time, the F2 port of the relief valve is also connected to the one-way valve and the oil tank in sequence, the E3 port of the lubrication directional control valve is connected to the land radiator and the oil tank in sequence, and the E4 port of the lubrication directional control valve is connected to the water radiator and the oil tank in sequence; the variable pump, solenoid valve III, solenoid valve IV, speed sensor I, speed sensor II, speed sensor III, pressure sensor I, and pressure sensor II are respectively connected to the electronic control unit.

2. A method for power switching and cooling of a special vehicle amphibious transfer case, characterized in that: The method comprises the following specific steps: A. When a special vehicle switches from a parking condition to a starting condition, the steps are as follows: (1) The electronic control unit receives an instruction to switch from a parking condition to a starting condition; (2) The hydraulic device starts working: The electronic control unit controls the variable pump to start working. The hydraulic oil in the oil tank passes through the coarse filter, variable pump, fine filter, overflow valve, E1 and E3 ports of the lubrication directional control valve, and the onshore radiator in sequence and returns to the oil tank; B. When a special vehicle is switched from the starting condition to the land condition, the steps are as follows: (1) The electronic control unit receives an instruction to switch from the start-up operating condition to the onshore operating condition; (2) Engagement of the land clutch G: An initial pressure is generated by the hydraulic oil branch AA, and the electronic control unit controls the solenoid valve III to be in the left working state. At this time, the hydraulic oil of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J, and A5 port of the reversing valve I in sequence, so that the reversing valve I is in the right working state; a part of the hydraulic oil of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I and the G1 port of the land clutch G in sequence, pushing the active part and the driven part of the land clutch G to start engaging until it is completed; at the same time, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in sequence, lubricates the E1 and E3 ports of the directional control valve, and is cooled by the land radiator. The cooled hydraulic oil flows back to the oil tank; When the active part and the driven part of the land clutch G are engaged, the electronic control unit measures the operating oil pressure value of the land clutch G in real time through the pressure sensor I, and measures the speed of the active part and the driven part of the land clutch G in real time through the speed sensor I and the speed sensor II, respectively, and converts them into angular velocity, and calculates the transmission slip work Q during the engagement process of the land clutch G in real time; when the calculated slip work Q is greater than the target slip work Q1, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G until the engagement is completed, and avoids clutch plate ablation caused by excessive slip work. The calculation formula of the slip work Q is as follows: Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, unit: s; P--clutch operating oil pressure, unit: MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c --The angular velocity of the clutch active part and the driven part, in rad / s; i1--The transmission ratio between the clutch driven part and the wheel; J t --Moment of inertia of the clutch driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, unit: kg·m 2 ; C. When a special vehicle is converted from land operation to water operation, the steps are as follows: (1) The electronic control unit receives a command to switch from the land working condition to the water and land working condition, and the land clutch G continues to be engaged; (2) The water clutch H and the water clutch L are engaged: the electronic control unit controls the solenoid valve IV to be in the left working state. At this time, the hydraulic oil of part of the hydraulic oil branch AA passes through the D1 port, the D3 port, the throttle hole K, and the C5 port of the reversing valve II in sequence, so that the reversing valve II is in the right working state. After the hydraulic oil of part of the hydraulic oil branch AA passes through the C2 and C3 ports of the reversing valve II, it is divided into three paths and enters the H1 port of the water clutch H, the L1 port of the water clutch L, and the E5 port of the lubricating directional control valve at the same time, pushing the active part and the driven part of the water clutch H and the water clutch L to start engaging until completion, and making the lubricating directional control valve in the left working state; then, the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in sequence, the E1 and E4 ports of the lubricating directional control valve, and is cooled by the water radiator. The cooled hydraulic oil flows back to the oil tank; When the active part and the driven part of the water clutch H and the water clutch L are engaged, the electronic control unit measures the operating oil pressure value of the water clutch L in real time through the pressure sensor II, and measures the speed of the active part of the land clutch G and the driven part of the water clutch L in real time through the speed sensor I and the speed sensor III respectively and converts them into angular velocity, and calculates the transmission friction work Q of the engagement process of the water clutch L in real time. When the calculated friction work Q is greater than the target friction work Q2, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the H1 and L1 ports, accelerates the engagement speed of the active part and the driven part of the water clutch H and the water clutch L until the engagement is completed, and avoids the clutch plate ablation of the water clutch H and the water clutch L due to excessive friction work. The calculation formula of the friction work Q is as follows: Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, unit: s; P--clutch operating oil pressure, unit: MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c --The angular velocity of the clutch active part and the driven part, in rad / s; i2--The transmission speed ratio between the clutch driven part and the propeller; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, unit: kg·m 2 ; D. When a special vehicle is converted from land-based working conditions to water-based working conditions, the steps are as follows: (1) The electronic control unit receives a command to switch from the amphibious working condition to the water working condition, and the water clutch H and the water clutch L continue to be engaged; (2) Disconnection of the land clutch G: The electronic control unit controls the solenoid valve III to be in the right working state, and a part of the hydraulic oil flows from the A5 port of the reversing valve I through the throttle hole J, the B3 port and the B2 port of the solenoid valve III to the oil tank; in this way, the reversing valve I is in the left working state due to the action of the spring force, and the hydraulic oil in the land clutch G flows from the G1 port through the A3 port and the A1 port of the reversing valve I to the oil tank; E. When a special vehicle is converted from water working condition to land working condition, the steps are as follows: (1) The electronic control unit receives a command to switch from the water working condition to the land working condition, and the water clutch H and the water clutch L continue to be engaged; (2) Engagement of the land clutch G: The electronic control unit controls the solenoid valve III to be in the left working state. At this time, the hydraulic oil of part of the hydraulic oil branch AA passes through the B1 port, B3 port, throttle hole J, and A5 port of the reversing valve I of the solenoid valve III in sequence, so that the reversing valve I is in the right working state; the hydraulic oil of part of the hydraulic oil branch AA passes through the A2 and A3 ports of the reversing valve I and the G1 port of the land clutch G in sequence, pushing the active part and the driven part of the land clutch G to start engaging until it is completed; at the same time, the hydraulic oil flowing through the E5 port makes the lubrication directional control valve in the left working state, and the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve in sequence, the E1 and E4 ports of the lubrication directional control valve, and is cooled by the water radiator. The cooled hydraulic oil flows back to the oil tank; When the active part and the driven part of the land clutch G are engaged, the electronic control unit measures the operating oil pressure value of the land clutch G in real time through the pressure sensor I. The electronic control unit measures the speed of the active part and the driven part of the land clutch G in real time through the speed sensor I and the speed sensor II respectively and converts them into angular velocity, and calculates the transmission friction work Q of the engagement process of the land clutch G in real time. When the calculated friction work Q is greater than the target friction work Q1, the electronic control unit controls the variable pump to increase the flow of hydraulic oil entering the G1 port, accelerates the engagement speed of the active part and the driven part of the land clutch G until the engagement is completed, and avoids clutch plate ablation caused by excessive friction work. The calculation formula of friction work Q is as follows: Where: t1--the time required for the angular velocity of the driven part to increase from zero to the angular velocity of the active part, unit: s; P--clutch operating oil pressure, unit: MPa; μ c --Friction coefficient of clutch friction plate; ω z ,ω c --The angular velocity of the clutch active part and the driven part, in rad / s; i1--The transmission ratio between the clutch driven part and the wheel; J t --Moment of inertia of the driven part, including the mass of the vehicle to the transfer case and then to the clutch driven part, unit: kg·m 2 ; F. When a special vehicle is converted from water-land operation to land operation, the steps are as follows: (1) The electronic control unit receives a command to switch from the water-land working condition to the land working condition, and the land clutch G continues to be engaged; (2) The water clutch H and the water clutch L are disconnected: the electronic control unit makes the solenoid valve IV work in the right position, and a part of the hydraulic oil flows from the C5 port of the reversing valve II, through the throttle hole K, the D3 port and the D2 port of the solenoid valve IV, and returns to the oil tank; in this way, the reversing valve II is in the left position due to the action of the spring force, and the hydraulic oil of the water clutch H, the water clutch L and the lubricating directional control valve flows out from the H1 port, the L1 port and the E5 port respectively and then flows through the C3 port and the C1 port of the reversing valve II in turn, and then returns to the oil tank; at this time, the lubricating directional control valve is in the right position due to the action of the spring force; the hydraulic oil of the hydraulic oil branch BB passes through the overflow valve, the E1 port and the E3 port of the lubricating directional control valve in turn, and is cooled by the land radiator, and the cooled hydraulic oil flows back to the oil tank; G. When a special vehicle is switched from the land-based operating condition to the starting operating condition, the steps are as follows: (1) The electronic control unit receives an instruction to switch from the onshore operating condition to the starting operating condition; (2) The land clutch G is disconnected: the electronic control unit puts the solenoid valve III in the right working state, and a part of the hydraulic oil returns to the oil tank from the A5 port of the reversing valve I through the throttle hole J, the B3 port and the B2 port of the solenoid valve III in sequence; in this way, the reversing valve I is in the left working state due to the spring force, and the hydraulic oil in the land clutch G returns to the oil tank from the G1 port through the A3 port and the A1 port of the reversing valve I in sequence; H. When a special vehicle switches from a starting condition to a parking condition, the steps are as follows: (1) The electronic control unit receives an instruction to switch from a starting condition to a parking condition; (2) The hydraulic device stops working: the hydraulic oil does not flow continuously and accumulates in the oil tank.

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