Study On The Clutch And Its Control System Of T.C+AMT

Nowadays, the technology of autoshift is progressing rapidly. Accordingly, Vehicular Automatic Transmission has many types. It can be divided into three main types: Automatic Transmission (AT), Automated Mechanical Transmission (AMT) and Continuously Variable Transmission (CVT). They have their different characteristics. Torque Converter (T.C) has the characteristics such as the adapting to out-load and lowing vibration efficiently and enlarging out-torque. And Automated Mechanical Transmission (AMT) is easy making with low cost and has high efficiency. It will be a new type of transmission to combine T.C and AMT, T.C+AMT automatic shift system, which not only has the benefit of the torque converter but also can be produced on the exist product line that can reduce the cost. It is one type of transmission with a good future. Combined with the cooperation research item "Development of T.C+AMT automatic shift system of the off-road vehicle"between Jilin University Hydraulic Mechanical Transmission Institute (HMTI) and the army, this dissertation mainly aimed on the study on the clutch and its control system of T.C+AMT. Because of the change of transmission's structure, the clutches'design and selection becomes more important. To accommodate the room changed, we choose multi-disc wet clutch, which has a more small size than dry clutch has, as the shift clutch. The key problems in the process of the design of clutch was discussed, such as how to determinate general arrangement, how to select the design parameter of friction pairs etc. Lockup clutch needs special friction materials. The relevant factors that affect the friction coefficient are discussed. It's useful for the following study on the control of lockup clutch. The application of torque converter in automatic transmission means an essential improvement of transmission technology to vehicle. The merit of torque converter makes that the automobile has smooth starting, and good gear shifting, but its usage make drive efficiency comes down affirmatively. An effective way to solve this question is to lock up the torque converter in some situation, so that torque converter takes effect in the process of vehicle's starting and gear shifting. This reduces oil loss effectively. Firstly this paper presents the work principle of lockup clutch, and then researches how to choose the point to lock up. Torque converter will lose its flexibility when drive efficiency is enhanced after lockup clutch locking up. So this paper analyzes what situation should lock up it. The hydraulic transmission is used in low shifts (1, 2 shift) and the high efficient lock-up control are applied in high shifts (3, 4, 5 shift) for the high fuel economic and spread the work field in the better road. According to the experimental data of engine and torque converter got from experiment, this paper study on the lock-up rule. And based on the two parameters control method, the paper presents several control signal, such as the throttle closing signal,the braking signal and the temperature signal and so on. This makes the lockup control of vehicle more reasonable. The throttle pressure characteristic effect the engage quality of Lockup clutch heavily. So its design approach is proposed, and a specific computer program is implemented. It ensures the clutch engages smoothly. The task of connection and separation of the clutch of T.C+AMT, and its quality control is accomplished by hydraulic system. The clutch control system is integrated by the control electromagnetic valves and sliding valves of the shift clutch,the lockup clutch and the torque converter. It is divided into three different parts based on function. They are pressure regulating control system, hydraulic system of torque converter and lockup clutch and shift clutch control system. This paper analyzes and researches detailed. Especially, hydraulic system of lockup clutch is analyzed as an important point. Lockup solenoid valve is a pulse width modulation (PWM) solenoid valve. Its behavior affects directly the throttle pressure characteristic of lockup clutch, and then affects the lockup quality of lockup clutch. This paper presents the process that it controls oil pressure. Lockup solenoid valve's duty ratio changes the oil pressure, so that the force to combine lock-up clutch changes. When sliding in the sliding-friction clutch of the automatic transmission, engine power is transmitted through both hydraulic transmission and mechanic sliding transmission, which can improve transmission efficiency in a large range. It can apparently improve transmission efficiency, cushion characteristic and vibration resistance of automatic transmission to select rational sliding control area. Engine torsional vibration condition, sliding rate of sliding clutch of automatic transmission,...