Modeling And Simulating Of The Valve Train Using Multi-body System Dynamics

The dynamics of valve train plays an important role in engine's working performance. deeplying researching on the valve train's dynamics is one of the important work to ensure the engine's whole performance index. Some modeling methods of the valve train are compared based on the commercial software, ustilized the multi-body system dynamics theories in this paper. The purpose is to exploring an effective way to do valve train's dynamics simulation. The main courses are as follows:1. To investigate the influence of the rotate speed, stiffness of valve spring, gas pressure and other factors on the dynamics performance of valve train, the rigid-body system model of single valve train is established, and then the dynamics simulation considering above factors is done.2. To discuss the influce of the flexilble-body models to dynamic characteristic and the influce of rotate speed to the multi-flexilble-body system dynamics model, the multi-flexible-body system dynamics model of the single valve train is established, and then the dynamics of the multi-flexilble-body system dynamics model is analyzed. The results of the multi-rigid-body system dynamics model and the multi-flexilble-body system dynamics model are compared.3. To research the modeling methods of the valve springs, the linear valve spring model, The non-linear valve spring model and the multi-mass valve spring model are established speratedly, the valve springs'characteristics and the effects on the valve train are analyzed.4. Aiming to search the influence of the distortion of camshaft for the valve train and the loads of camshaft bearings, the multi-flexible-body system dynamics model of whole line mechanism is built and analyzed. 5. To calulate the influence of the crank train and drivering train to the dynamic analysis of the valve train and the loads of camshaft bearings, the multi-body model of a V8 diesel engine is built and simulated.Finally, by summarizing the methods above, the techniques and methods of building and simulating the valve train's models were put forward.