Large-torque automatic transmission heat dissipation system and working and checking method thereof

Abstract

The invention discloses a large-torque automatic transmission cooling system and a working and checking method thereof, and belongs to the technical field of transmissions. Comprising a water-cooling oil cooler used for cooling transmission oil through water circulation, an air-cooling oil cooler connected with the water-cooling oil cooler and used for cooling the transmission oil through air convection, a three-way valve arranged on an oil inlet pipeline of the air-cooling oil cooler and used for switching the flow direction of the transmission oil, and a water-cooling oil cooler matched with the air-cooling oil cooler and used for cooling the transmission oil. The cooling fan is used for enhancing the heat dissipation effect of the air-cooled oil cooler, and the sensors are arranged on the oil inlet pipeline and the oil outlet pipeline and used for monitoring and recording the temperature, pressure and flow of transmission oil in real time. The temperature, the pressure and the flow of transmission oil are directly measured through the sensor, the heating value and heating power parameters of the transmission in the whole vehicle state under the maximum heating value working condition can be accurately captured, accurate demand basis is provided for a heat dissipation system, the development cost is reduced, the development period is shortened, and the marketing progress of products is accelerated.

Description

Technical Field

[0001] The invention relates to a large-torque automatic transmission heat dissipation system and a working and testing method thereof, belonging to the technical field of transmissions. Background Art

[0002] The shifting logic, oil pressure coordination of various components during the shifting process and other control logic and calibration principles of the high-torque automatic transmission of medium and heavy-duty trucks are significantly different from those of passenger cars. This not only increases the difficulty of research and development, but also puts higher requirements on the overall performance of the transmission.

[0003] For high-torque automatic transmissions, the design and assessment of their cooling systems has become a crucial link. Under low-speed, low-gear, and torque converter torque-increasing conditions, the transmission heat generation increases significantly. However, due to the low speed, the headwind from the vehicle body has a weak cooling effect on the vehicle, which poses a severe challenge to the transmission's cooling system. How to accurately determine the heat generation of the transmission in this state and confirm whether the cooling performance of the cooling system meets the requirements has become an urgent problem to be solved in the forward development stage of the transmission.

[0004] Traditionally, the design and verification of cooling systems often rely on experience accumulation and repeated tests. This method is not only time-consuming and costly, but also has great uncertainty. If the cooling system is not designed properly, it may cause local overheating of the transmission in a short period of time, and then burn the internal components; on the contrary, if the cooling system is too large, it will not only increase the weight of the vehicle body and manufacturing costs, but also may cause the transmission oil temperature to be unable to reach the normal working range for a long time, affecting the test efficiency and the effectiveness of the results.

[0005] Therefore, developing a cooling system that can accurately measure the heat generation and heat dissipation performance of a high-torque automatic transmission in the whole vehicle state is of great significance for improving the research and development efficiency and product quality of high-torque automatic transmissions for medium and heavy-duty trucks. Summary of the invention

[0006] In order to solve the problems existing in the background technology, the present invention provides a large torque automatic transmission heat dissipation system and its working and assessment methods.

[0007] To achieve the above object, the present invention adopts the following technical solution: a high torque automatic transmission cooling system, comprising

[0008] A water-cooled oil cooler is used to cool the transmission oil through water circulation;

[0009] An air-cooled oil cooler 1, connected to the oil inlet end of the water-cooled oil cooler, for cooling the transmission oil by air convection;

[0010] an air-cooled oil cooler 2, connected to the oil outlet end of the water-cooled oil cooler, for cooling the transmission oil by air convection;

[0011] A three-way valve 1, arranged on the oil inlet pipe of the air-cooled oil cooler 1, is used to switch whether the transmission oil flows directly to the water-cooled oil cooler or flows to the water-cooled oil cooler after being cooled by the air-cooled oil cooler 1;

[0012] Three-way valve 2, arranged on the oil inlet pipe of air-cooled oil cooler 2, used to switch whether the transmission oil flows directly back to the transmission or flows back to the transmission after being cooled by air-cooled oil cooler 2;

[0013] A cooling fan 1, cooperating with an air-cooled oil cooler 1, is used to enhance the heat dissipation effect of the air-cooled oil cooler 1;

[0014] The second cooling fan cooperates with the second air-cooled oil cooler to enhance the heat dissipation effect of the second air-cooled oil cooler;

[0015] A throttle valve is provided on the oil inlet pipe of the water-cooled oil cooler and is used to adjust the flow of the transmission oil entering the water-cooled oil cooler, thereby controlling the heat dissipation;

[0016] Temperature sensors are arranged on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler, the air-cooled oil cooler 1 and the air-cooled oil cooler 2, and are used to monitor and record the temperature of the transmission oil in real time;

[0017] A pressure sensor is provided on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler, the air-cooled oil cooler 1 and the air-cooled oil cooler 2, and is used to monitor and record the pressure of the transmission oil in real time;

[0018] A flow sensor is provided on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler, the air-cooled oil cooler 1 and the air-cooled oil cooler 2, and is used to monitor and record the flow data of the transmission oil in real time;

[0019] The control system is used to receive sensor data, control the working status of the throttle valve, three-way valve and cooling fan to simulate the transmission cooling requirements under different working conditions and evaluate the performance of the cooling system.

[0020] The working states of the heat dissipation system include a normal vehicle driving working state, a first-level warning temperature working state, a second-level warning temperature working state, a third-level warning temperature working state, and a fourth-level warning temperature working state.

[0021] The working process of the cooling system in the normal driving state of the vehicle is as follows:

[0022] S1: Transmission oil flows out from the transmission oil outlet and flows to three-way valve 1;

[0023] S2: Transmission oil flows into the water-cooled oil cooler through three-way valve one;

[0024] S3: The transmission oil flows to three-way valve 2 after being cooled by the water-cooled oil cooler;

[0025] S4: The transmission oil flows back to the transmission from the transmission oil inlet through three-way valve 2.

[0026] The working process of the first-level warning temperature working state of the heat dissipation system is as follows:

[0027] S1: Transmission oil flows out from the transmission oil outlet and flows to three-way valve 1;

[0028] S2: The transmission oil flows into the air-cooled oil cooler 1 through the three-way valve 1;

[0029] S3: The transmission oil flows into the water-cooled oil cooler through the air-cooled oil cooler;

[0030] S4: The transmission oil flows to three-way valve 2 after being cooled by the water-cooled oil cooler;

[0031] S5: The transmission oil flows back to the transmission from the transmission oil inlet through three-way valve 2.

[0032] The working process of the secondary warning temperature working state of the cooling system is as follows:

[0033] S1: Transmission oil flows out from the transmission oil outlet and flows to three-way valve 1;

[0034] S2: The transmission oil flows into the air-cooled oil cooler 1 through the three-way valve 1;

[0035] S3: The transmission oil flows into the water-cooled oil cooler through the air-cooled oil cooler;

[0036] S4: The transmission oil flows to three-way valve 2 after being cooled by the water-cooled oil cooler;

[0037] S5: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 2;

[0038] S6: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2.

[0039] The working process of the three-level warning temperature working state of the heat dissipation system is as follows:

[0040] S1: Turn on the corresponding cooling fan 1;

[0041] S2: Transmission oil flows out from the transmission oil outlet and flows to three-way valve 1;

[0042] S3: The transmission oil flows into the air-cooled oil cooler 1 through the three-way valve 1;

[0043] S4: The transmission oil flows into the water-cooled oil cooler through the air-cooled oil cooler;

[0044] S5: The transmission oil flows to three-way valve 2 after being cooled by the water-cooled oil cooler;

[0045] S6: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 2;

[0046] S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2.

[0047] The working process of the cooling system's four-level warning temperature working state is as follows:

[0048] S1: Turn on cooling fan 1 and cooling fan 2;

[0049] S2: Transmission oil flows out from the transmission oil outlet and flows to three-way valve 1;

[0050] S3: The transmission oil flows into the air-cooled oil cooler 1 through the three-way valve 1;

[0051] S4: The transmission oil flows into the water-cooled oil cooler through the air-cooled oil cooler;

[0052] S5: The transmission oil flows to three-way valve 2 after being cooled by the water-cooled oil cooler;

[0053] S6: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 2;

[0054] S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2.

[0055] A method for evaluating a heat dissipation system of a large torque automatic transmission according to the present invention comprises the following steps:

[0056] S1: Replace the test vehicle with the transmission to be tested;

[0057] S2: Connect the transmission to the cooling system and fix the cooling system to the chassis;

[0058] S3: According to the preset test conditions, the test vehicle is driven to perform regular vehicle driving, and the inlet and outlet oil temperature, pressure and flow data of the transmission are collected in real time through the cooling system;

[0059] S4: Record various data during the test;

[0060] S5: comparing the test data with a preset transmission oil outlet temperature upper limit warning value to determine whether the transmission oil temperature exceeds the standard;

[0061] S6: If the transmission oil temperature exceeds the standard, manually start the corresponding air-cooled oil cooler and / or cooling fan in the cooling system to force the transmission to dissipate heat;

[0062] S7: Record and analyze the test results, and confirm the peak heat generation of the transmission through calculation.

[0063] The calculation formula of the heat output is as follows:

[0064] Q p =qC·ρ(T out -T in ) / 60

[0065] Where:

[0066] Q p Indicates the heat generated by the transmission;

[0067] q represents the transmission oil flow rate;

[0068] C represents the specific heat capacity of the transmission oil;

[0069] ρ represents the transmission oil density;

[0070] T out Indicates the transmission oil temperature after cooling;

[0071] T in Indicates the transmission oil temperature before cooling.

[0072] Compared with the prior art, the present invention has the following beneficial effects:

[0073] The present invention directly measures the temperature, pressure and flow of the transmission oil through sensors, thereby improving the accuracy of the design of the cooling system of a large torque automatic transmission. It can accurately capture the heat generation and heating power parameters of the transmission under the maximum heat generation condition in the whole vehicle state, provide an accurate demand basis for the cooling system, reduce development costs and time cycles, and accelerate the product's launch process. At the same time, the actual heat generation of the transmission and the upper limit of the cooling capacity of the cooling system can be confirmed through a one-time test, providing a solid foundation for the subsequent realization of the radiator performance index requirements through engineering redundant control, and enhancing the robustness and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a structural schematic diagram of the heat dissipation system of a large torque automatic transmission of the present invention;

[0075] Figure 2 It is a schematic diagram of the working process of the cooling system in the normal driving working state of the vehicle;

[0076] Figure 3 It is a working process diagram of the first-level warning temperature working state of the cooling system;

[0077] Figure 4 It is a schematic diagram of the working process of the secondary warning temperature working state of the cooling system. DETAILED DESCRIPTION

[0078] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0079] In the process of developing new products with high torque automatic transmissions, the design of the cooling system and the confirmation of the cooling power have become the focus. The cooling system has various configurations, including air cooling, water cooling and compressor cooling, but in conventional applications, air cooling and water cooling are more common. For medium and heavy trucks, the choice of cooling system is particularly critical. Since these vehicles mostly operate under medium and low speed and heavy load conditions, the cooling effect of the air cooling system is often not ideal, so the water cooling system becomes the first choice. However, the water cooling system increases the load on the engine cooling system in the powertrain system.

[0080] At present, the engine cooling system of medium and heavy trucks in my country generally has a 30% heat load control upper limit to ensure the stable operation of the system. In this context, the present invention adopts the engine water cooling system as the main configuration, aiming to accurately evaluate the heat generation capacity of the transmission by maximizing the use of the engine's heat dissipation power upper limit.

[0081] A high-torque automatic transmission cooling system, comprising:

[0082] A water-cooled oil cooler 1, used for cooling the transmission oil through water circulation;

[0083] An air-cooled oil cooler 2 is connected to the oil inlet end of the water-cooled oil cooler 1 and is used to cool the transmission oil by air convection;

[0084] The air-cooled oil cooler 2 6 is connected to the oil outlet end of the water-cooled oil cooler 1 and is used to cool the transmission oil by air convection;

[0085] A three-way valve 3 is provided on the oil inlet pipe of the air-cooled oil cooler 2, and is used to switch whether the transmission oil flows directly to the water-cooled oil cooler 1 or flows to the water-cooled oil cooler 1 after being cooled by the air-cooled oil cooler 2;

[0086] A three-way valve 24, provided on the oil inlet pipe of the air-cooled oil cooler 26, for switching whether the transmission oil flows directly back to the transmission or flows back to the transmission after being cooled by the air-cooled oil cooler 26;

[0087] A cooling fan 5 cooperates with an air-cooled oil cooler 2 to enhance the heat dissipation effect of the air-cooled oil cooler 2;

[0088] A cooling fan 2 7 cooperates with the air-cooled oil cooler 2 6 to enhance the heat dissipation effect of the air-cooled oil cooler 2 6;

[0089] A throttle valve is provided on the oil inlet pipe of the water-cooled oil cooler 1 and is used to adjust the flow of the transmission oil entering the water-cooled oil cooler 1, thereby controlling the heat dissipation;

[0090] Temperature sensors are provided on the oil inlet and outlet pipes of the water-cooled oil cooler 1, the air-cooled oil cooler 2, and the air-cooled oil cooler 2 6, and are used to monitor and record the temperature of the transmission oil in real time;

[0091] Pressure sensors are provided on the oil inlet and outlet pipes of the water-cooled oil cooler 1, the air-cooled oil cooler 2 and the air-cooled oil cooler 2 6, and are used to monitor and record the pressure of the transmission oil in real time;

[0092] Flow sensors are arranged on the oil inlet and outlet pipes of the water-cooled oil cooler 1, the air-cooled oil cooler 2 and the air-cooled oil cooler 6, and are used to monitor and record the flow data of the transmission oil in real time;

[0093] The control system is used to receive sensor data, control the working status of the throttle valve, three-way valve and cooling fan to simulate the transmission cooling requirements under different working conditions and evaluate the performance of the cooling system.

[0094] The working states of the heat dissipation system include a normal vehicle driving working state, a first-level warning temperature working state, a second-level warning temperature working state, a third-level warning temperature working state, and a fourth-level warning temperature working state.

[0095] The working process of the cooling system in the normal driving state of the vehicle is as follows:

[0096] S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 13;

[0097] S2: The transmission oil flows into the water-cooled oil cooler 1 through the three-way valve 3;

[0098] S3: The transmission oil is cooled by the water-cooled oil cooler 1 and flows to the three-way valve 2 4;

[0099] S4: The transmission oil flows back to the transmission from the transmission oil inlet through the three-way valve 24.

[0100] The working process of the first-level warning temperature working state of the heat dissipation system is as follows:

[0101] S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 13;

[0102] S2: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 3;

[0103] S3: The transmission oil flows into the water-cooled oil cooler 1 through the air-cooled oil cooler 2;

[0104] S4: The transmission oil is cooled by the water-cooled oil cooler 1 and flows to the three-way valve 2 4;

[0105] S5: The transmission oil flows back to the transmission from the transmission oil inlet through the three-way valve 24.

[0106] At this time, since the working load is not too large, the heat can be dissipated by self-cooling through the air-cooled oil cooler.

[0107] The working process of the secondary warning temperature working state of the cooling system is as follows:

[0108] S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 13;

[0109] S2: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 3;

[0110] S3: The transmission oil flows into the water-cooled oil cooler 1 through the air-cooled oil cooler 2;

[0111] S4: The transmission oil is cooled by the water-cooled oil cooler 1 and flows to the three-way valve 2 4;

[0112] S5: The transmission oil flows into the air-cooled oil cooler 26 through the three-way valve 24;

[0113] S6: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 26.

[0114] The working process of the three-level warning temperature working state of the heat dissipation system is as follows:

[0115] S1: Turn on the corresponding cooling fan 5;

[0116] S2: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 13;

[0117] S3: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 3;

[0118] S4: The transmission oil flows into the water-cooled oil cooler 1 through the air-cooled oil cooler 2;

[0119] S5: The transmission oil is cooled by the water-cooled oil cooler 1 and flows to the three-way valve 2 4;

[0120] S6: The transmission oil flows into the air-cooled oil cooler 26 through the three-way valve 24;

[0121] S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 26.

[0122] The working process of the cooling system's four-level warning temperature working state is as follows:

[0123] S1: Turn on cooling fan 1 5 and cooling fan 2 7;

[0124] S2: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 13;

[0125] S3: The transmission oil flows into the air-cooled oil cooler 2 through the three-way valve 3;

[0126] S4: The transmission oil flows into the water-cooled oil cooler 1 through the air-cooled oil cooler 2;

[0127] S5: The transmission oil is cooled by the water-cooled oil cooler 1 and flows to the three-way valve 2 4;

[0128] S6: The transmission oil flows into the air-cooled oil cooler 26 through the three-way valve 24;

[0129] S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 26.

[0130] The purpose of setting up multi-level cooling is to accurately determine the transmission heating and heat dissipation supply and demand. In addition, one or two cooling levels can be reserved to ensure that the radiator has a high temperature margin to deal with sudden thermal risks.

[0131] A method for evaluating a heat dissipation system of a large torque automatic transmission according to the present invention comprises the following steps:

[0132] S1: Replace the test vehicle with the transmission to be tested;

[0133] S2: Connect the transmission to the cooling system and fix the cooling system to the chassis;

[0134] The cooling system water-cooled oil cooler controls the current cooling capacity at 30% of the total engine power by adjusting the transmission oil flow through an internal throttle valve.

[0135] S3: According to the preset test conditions, the test vehicle is driven to perform normal vehicle driving, and the temperature, pressure and flow rate data of the inlet and outlet oil of the transmission are collected in real time through the temperature, pressure and flow rate sensors on the cooling system;

[0136] S4: Record various data during the test;

[0137] S5: comparing the test data with a preset transmission oil outlet temperature upper limit warning value to determine whether the transmission oil temperature exceeds the standard;

[0138] S6: If the transmission oil temperature exceeds the standard, manually start the corresponding air-cooled oil cooler and / or cooling fan in the cooling system to force the transmission to dissipate heat;

[0139] S7: Record and analyze the test results, and confirm the peak heat generation of the transmission through calculation.

[0140] The calculation formula of the heat output is as follows:

[0141] Q p =qC·ρ(T out –T in ) / 60

[0142] Where:

[0143] Q p Indicates the heat generated by the transmission in kw;

[0144] q represents the transmission oil flow rate L / min;

[0145] C represents the specific heat capacity of transmission oil kJ / kg*℃;

[0146] ρ represents the transmission oil density (kg / m 3 );

[0147] T out Indicates the transmission oil temperature after cooling (℃);

[0148] T in Indicates the transmission oil temperature before cooling in °C.

[0149] The above formula can be used to calculate the actual heat generated by the transmission at this time, and reasonable requirements can be made on the heat dissipation capacity of the transmission cooling system according to the company's engineering control objectives and safety factor settings for the product, thereby providing strong data support for the design parameter data.

[0150] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0151] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high torque automatic transmission cooling system, characterized in that: include A water-cooled oil cooler (1) is used to cool the transmission oil through water circulation; An air-cooled oil cooler (2) connected to the oil inlet end of the water-cooled oil cooler (1) for cooling the transmission oil by air convection; An air-cooled oil cooler 2 (6) is connected to the oil outlet end of the water-cooled oil cooler (1) and is used to cool the transmission oil by air convection; A three-way valve (3) is arranged on the oil inlet pipe of the air-cooled oil cooler (2) and is used to switch whether the transmission oil flows directly to the water-cooled oil cooler (1) or flows to the water-cooled oil cooler (1) after being cooled by the air-cooled oil cooler (2); A three-way valve (4) is provided on the oil inlet pipe of the air-cooled oil cooler (6) to switch whether the transmission oil flows directly back to the transmission or flows back to the transmission after being cooled by the air-cooled oil cooler (6); A cooling fan (5) cooperates with the air-cooled oil cooler (2) to enhance the heat dissipation effect of the air-cooled oil cooler (2); A cooling fan 2 (7), in cooperation with the air-cooled oil cooler 2 (6), is used to enhance the heat dissipation effect of the air-cooled oil cooler 2 (6); A throttle valve is arranged on the oil inlet pipeline of the water-cooled oil cooler (1) and is used to adjust the flow rate of the transmission oil entering the water-cooled oil cooler (1), thereby controlling the heat dissipation; Temperature sensors are arranged on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler (1), the air-cooled oil cooler 1 (2) and the air-cooled oil cooler 2 (6), and are used to monitor and record the temperature of the transmission oil in real time; A pressure sensor is arranged on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler (1), the air-cooled oil cooler 1 (2) and the air-cooled oil cooler 2 (6), and is used to monitor and record the pressure of the transmission oil in real time; A flow sensor is arranged on the oil inlet pipe and the oil outlet pipe of the water-cooled oil cooler (1), the air-cooled oil cooler 1 (2) and the air-cooled oil cooler 2 (6), and is used for real-time monitoring and recording the flow data of the transmission oil; The control system is used to receive sensor data, control the working status of the throttle valve, three-way valve and cooling fan to simulate the transmission cooling requirements under different working conditions and evaluate the performance of the cooling system.

2. A high torque automatic transmission cooling system according to claim 1, characterized in that: The working states of the heat dissipation system include a normal vehicle driving working state, a first-level warning temperature working state, a second-level warning temperature working state, a third-level warning temperature working state, and a fourth-level warning temperature working state.

3. A high torque automatic transmission cooling system according to claim 2, characterized in that: The working process of the cooling system in the normal driving state of the vehicle is as follows: S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 1 (3); S2: The transmission oil flows into the water-cooled oil cooler (1) through the three-way valve 1 (3); S3: The transmission oil is cooled by the water-cooled oil cooler (1) and then flows to the three-way valve 2 (4); S4: The transmission oil flows back to the transmission from the transmission oil inlet through the three-way valve 2 (4).

4. A high torque automatic transmission cooling system according to claim 2, characterized in that: The working process of the first-level warning temperature working state of the heat dissipation system is as follows: S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 1 (3); S2: The transmission oil flows into the air-cooled oil cooler one (2) through the three-way valve one (3); S3: The transmission oil flows into the water-cooled oil cooler (1) through the air-cooled oil cooler 1 (2); S4: The transmission oil is cooled by the water-cooled oil cooler (1) and then flows to the three-way valve 2 (4); S5: The transmission oil flows back to the transmission from the transmission oil inlet through the three-way valve 2 (4).

5. The high torque automatic transmission cooling system according to claim 2, characterized in that: The working process of the secondary warning temperature working state of the cooling system is as follows: S1: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 1 (3); S2: The transmission oil flows into the air-cooled oil cooler one (2) through the three-way valve one (3); S3: The transmission oil flows into the water-cooled oil cooler (1) through the air-cooled oil cooler 1 (2); S4: The transmission oil is cooled by the water-cooled oil cooler (1) and then flows to the three-way valve 2 (4); S5: The transmission oil flows into the air-cooled oil cooler 2 (6) through the three-way valve 2 (4); S6: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2 (6).

6. A high torque automatic transmission cooling system according to claim 2, characterized in that: The working process of the three-level warning temperature working state of the heat dissipation system is as follows: S1: Turn on the corresponding cooling fan 1 (5); S2: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 1 (3); S3: The transmission oil flows into the air-cooled oil cooler one (2) through the three-way valve one (3); S4: The transmission oil flows into the water-cooled oil cooler (1) through the air-cooled oil cooler 1 (2); S5: The transmission oil is cooled by the water-cooled oil cooler (1) and then flows to the three-way valve 2 (4); S6: The transmission oil flows into the air-cooled oil cooler 2 (6) through the three-way valve 2 (4); S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2 (6).

7. The high torque automatic transmission cooling system according to claim 2, characterized in that: The working process of the four-level warning temperature working state of the heat dissipation system is as follows: S1: Turn on cooling fan 1 (5) and cooling fan 2 (7); S2: The transmission oil flows out from the transmission oil outlet and flows to the three-way valve 1 (3); S3: The transmission oil flows into the air-cooled oil cooler one (2) through the three-way valve one (3); S4: The transmission oil flows into the water-cooled oil cooler (1) through the air-cooled oil cooler 1 (2); S5: The transmission oil is cooled by the water-cooled oil cooler (1) and then flows to the three-way valve 2 (4); S6: The transmission oil flows into the air-cooled oil cooler 2 (6) through the three-way valve 2 (4); S7: The transmission oil flows back to the transmission from the transmission oil inlet through the air-cooled oil cooler 2 (6).

8. A method for evaluating a heat dissipation system of a large torque automatic transmission according to claim 2, characterized in that: The method comprises the following steps: S1: Replace the test vehicle with the transmission to be tested; S2: Connect the transmission to the cooling system and fix the cooling system to the chassis; S3: According to the preset test conditions, the test vehicle is driven to perform regular vehicle driving, and the inlet and outlet oil temperature, pressure and flow data of the transmission are collected in real time through the cooling system; S4: Record various data during the test; S5: comparing the test data with a preset transmission oil outlet temperature upper limit warning value to determine whether the transmission oil temperature exceeds the standard; S6: If the transmission oil temperature exceeds the standard, manually start the corresponding air-cooled oil cooler and / or cooling fan in the cooling system to force the transmission to dissipate heat; S7: Record and analyze the test results, and confirm the peak heat generation of the transmission through calculation.

9. The method according to claim 8, characterized in that: The calculation formula of the heat amount described in S7 is as follows: Q p =qC·ρ(T out -T in ) / 60 Where: Q p Indicates the heat generated by the transmission; q represents the transmission oil flow rate; C represents the specific heat capacity of the transmission oil; ρ represents the transmission oil density; T out Indicates the transmission oil temperature after cooling; T in Indicates the transmission oil temperature before cooling.

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