The Characteristic Study And Optimization Analysis Of Dual Mass Flywheel

The ride performance and comfort degree of automobile would become poor when the powertrain of the vehicle was inspired with vibrations, the main resource of which is the torque undulation of the engine crank. In order to reduce this vibration, torsional dampers are set into the automobile transmission. As a new type of torsional vibration absorber, Dual Mass Flywheel (DMFW or DMF) is highly valued due to its excellent damping properties.Through brief introduction of research overview on dual mass flywheel, multi-degree-of-freedom torsional vibration models of automobile power train equipped with DMFW are built in this project. Transmission virtual prototyping is established in the software of MATLAB/Simulink so that characteristics of DMFW can be analyzed. On this basis, the probability of DMFW optimization is discussed. The main research includes:Firstly, by the analysis of DMFW structure, simulation model of vehicle powertrain is built in MATLAB/Simulink. In driving and idling condition, 15-freedom and 8-freedom models of a certain type of six-cylinder diesel truck transmission are built; and simulation module charts are established in Simulink through kinetic equations of the model.Secondly, vibration characteristics of dual mass flywheel are analyzed. In driving and idling condition, forced vibration of vehicle powertrain is simulated; by comparing with clutch torsional damper, excellent damping property of DMFW is testified. And free vibration characteristic of DMFW is analyzed through the study of free frequency and free mode of automobile powertrain vibration.Finally, optimization analysis of dual mass flywheel is discussed. By the method of setting damping devices into primary and secondary flywheel, optimization model of DMFW can be built. Through the use of Lagrange method, kinetic equations of automobile transmission, both in driving and idling condition, can be obtained. Based on damping effect, optimization structure of DMFW is confirmed and parameters of optimization model are found by L25(56) orthogonal test. And then, verify free frequency of the optimization model to attest the feasibility of this optimization.Since there is considerable room for the development of DMFW, it is of great significance to research on the vibration characteristic and optimization probability of dual mass flywheel.