Research On The Power Loss Characteristics Caused By Driving Force Interrupt During Shifting Process Of Heavy-duty AMT

With the continuous development of the automotive industry, road transport has become one of the important mode of transport. The heavy-duty vehicle is the main tool of the road transport. However, the traditional manual transmission on heavy-duty vehicles reveals weaknesses, because of its poor dynamic property and economy property, and frequently shifting making the driver tired. So it is very necessary to install automatic transmission on heavy vehicles. The automatic mechanical transmission has been well developed which is adapted to heavy-duty vehicles.But the AMT is non-power-shift automatic transmission, the shift process has power interruption, and power loss in the process. Although the power loss in one shifting process is small, there will be a great loss in terms of power and economy because of frequency of the shift action. Based on shifting the power interruption, this article will analyzes the power loss characteristics and influencing factors, and gain the power loss by the computer simulation. Specifically, the full-text content can be divided into four parts as followed:1) Overview the development of automotive automatic transmission, basic working principle of AMT, the status of domestic and international research, and briefly introduce the application development and key technologies of AMT.2) Analyze the AMT shifting process. There are three stages in AMT shifting process: the power interrupt, shifting and power recovery. It is also analysed the influnce to the shifting process and shift quality by shift schedule, engine control, clutch control and shift timing control.3) The dynamic model is established to analyze the process. In order to intruduce the details of the clutch and synchronizer sliding friction process, a clutch model in the bonding process and the model linked file synchronizer stage are established. Through these models, the calculate method of clutch friction work and synchronizer friction work can be got, as well as the three main effect factors of the power loss in the shift process:torque factor, rotational speed factor and time factor.4) With the calculate method of the power loss during the gear shifting process, the simulation model will be established based on Matlab\Simulink, using parameters of certain model heavy vehicle, and its corresponding shift schedule. Then the result including friction work, work on each unit friction area and frictoin time will be got by the relevant simulation, and the results were processed and analyzed.The research of this issue has some theoretical and practical significance to the further study on the power loss characteristics caused by driving force interrupt during shifting process and improving the shifting performance of AMT, and the development of heavy-duty vehicles.