| The automatic transmission technology of the vehicle has entered into intelligent times, it is the tendency of automatic transmission technology for vehicle to design and develop automatic transmission system which is intelligent in current.Traditional vehicle is pure mechanical basically,modern vehiocle has became a synthesized carrier of electromechanical integrative system and various new technology.In this paper,in order to solve the problem of the transmission efficiency of construction vehicle hydrodynamic drive degrade largely under heavy load,the theoretical and experimental research in pursuit of high transmission efficiency on vehicular automatic transmission was progressed that aimed at the project of National Foundation for National Sciences:Research on Automatic Transmission Technology for Construction Machinery(serial number:50075033).In the dissertation,efficiency shift schedule of ZL50 wheel loader is found with analytical method by analyzing corporate work of engine ,hydrodynamic torque converter and gearbox.The dissertation is thought to be a theoretic and experimental study to apply fuzzy control technology to the automatic control for hydrodynamic transmission of construction vehicle,with the purpose to improve the efficiency of automatic transmission. Combined with dynamic simulation technology, simulation research on automatic transmission system of construction vehicle is carried through. Finally, a testing experiment on integrated performance of automatic transmission control system is carried out.Test result shows that vehicle can be adjusted to appropriate shift according to the change of load ,it is effective and reliable that system intelligence controls for automatic transmission for construction vehicle,it can maintain hydraulic torque converter to work in efficient district. Following is the introduction about every chapter of the dissertation. In chapter one, the development trends of vehicle's automatic transmission oversea and inland are introduced according to the phylogeny of automatic transmission technology and the application productions of the technology in construction machinery are emphasized. The main researching contents of automatic transmission technology are analysed,the developmental orientation of automatic transmission for vehicle is made certain. Referring to the situation of our country, the important significance of adopting automatic transmission on construction vehicle is discussed. Intellectualized control system and integrated vehicular electronic system are the two features and developmental trend of the AT technology. Moreover, the main researching contents of the dissertation are outlined.In chapter two, the kinetic mathematical models of the hydro-mechanical transmission system of construction vehicle are set up.The kinetic transmossion ofConstruction is analysed. Taking the powertrain system equipped on ZL50 wheel loader as research object, by means of theory analysis and experiment data, the kinetic models of engine, torque converter, gearbox, bodywork and load resistense and etc are figured out in detail. The matching problem for the co-operation characterisic of engine and torque converter is developed,control model is set up ,too.In the basic, the kinetic equation of vehicle running is brought forward. In theory, the works above is a good preparation for the subsequent computer simulation of automatic transmission control of construction vehicle .After the studying on the cooperating input and output characteristic between the torque converter and the engine, the paper provides several calculating methods on the cooperating point: geometry method, resolving method ,optimizing method and accelerating method.The discuss is applied to all hydraulic mechanical transmission with torque converter,and it is important to design torque converter reasonable.In chapter three, the research on hydraulic mechanical transmission system and efficiency shift schedule.The characteristic of hydraulic mechanical is introduced,the feature of torque con... |
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