Research On AMT Shift Mechanism And Shift Method Of Commercial Vehicle

With the development of automotive technology, intelligent simple operation has become a trend. The most direct simplify operation for the pilot is that transmission upgrade from manual to automatic transmission,which not only lowers the standard of driving requirement, reduces operating fatigue, but reduce fuel consumption. AT present, the mainstream of the automatic transmission is divided into with hydraulic torque converter of planetary wheel automatic transmission(AT), electronically controlled automatic mechanical transmission(AMT), dual clutch automatic transmission(DCT) and continuously variable transmission(CVT) four categories, this thesis mainly studies the AMT transmission shift method which applied most widely used in commercial vehicles and size control problem of related parts.The domestic AMT technology has been basically mature through the efforts of the domestic automobile enterprise and overseas technology introduction, but there is a certain gap compared with foreign products especially in commercialization. The reason varies from the state judgment of vehicle driving to the strategy of driver’s intention recognition, including shift method optimization, the design optimization of shifting device and the details of component consistency control as well. In this thesis, combining with technical difficulties and solving strategies which were met in development process of two commercial vehicle AMT in the technical center of FAW, through the analysis of shift process for commercial vehicles with synchronizer AMT, the thesis focus on solving the problem of early wear synchronizer related parts, including the control of synchronization force and the change of gear shift control method, reducing auxiliary engine speed and difference of synchronous speed downshifts methods. For AMT without synchronizer, the key problems lie in solving the problem of huge shift impact, synchronous speed is optimized and the shift shock is decreased through the experiments. It puts forward a series of best optimal temperature of synchronous speed, different temperature shift method were summarized when the different tests are carried on for AMT shit under varied temperature. For deputy box with heavy duty vehicle,It spends long time for deputy box shift under the low temperature state,,it analyzes and test respectively for double the intermediate shaft type and planetary wheel deputy vice box, by studying the forward reducing resistance and reverse way to increase power, to give in-depth study from the synchronous of using the main box assistant deputy box and reduce the main drag resistance.Finally, the result of the test in AMT control strategy, product design, processing and manufacturing control and reliability will be applied, as same time the preliminary application effect are estimated. Furthermore, it solves the inadaptable problems which appear after the change from manual mechanical transmission to AMT control.