Optimal Design And Research Of Engine Valve Cam

The valve train is one of the most important mechanisms in a internal combustion engine, whether the performances are good or bad, that afecting the power performance, of the engine. Cam is the hard core of the valve train, which afecting the performance of the valve train. And how to design and make a Cam , whose profile is suitable is one of the most important problem to the valve train optimal design. The performances of the Cam profile are good or bad affects the power performance, economic performance, emissions performance of the engine,as well as affects the reliability and wear performances of the whole engine. Simulation calculation and experimentation research are two important ways to carry out research and development on valve train of internal-combustion engine.In this paper, the kinematics and dynamics model on valve train of the engine are built up with AVL TYCON, the performances on the valve train are calculated, some problems on the valve train are made certain, in order to solve the problems, the cam profiles are designed, some factors of cam profile designing are analyzed. Then forces testing on the mechanisms of the valve train are carried out on the engine experiment bench, to validate the validity of simulation calculation and the feasibility of the designing. The main research work include:(1) The solid model on valve train of the engine are built up with Pro/E. We can get all the physical parameters from the solid model. The kinematics and dynamics model on valve train of the engine are built up with TYCON. The performances calculation of the valve train indicate that the fullness ratios of intake valve curve is on the low side, and the maximum contact stress between intake cam and tappet is higher, the same problem exists in the exhaust part, and the lubrication function between exhaust cam and tappet is bad.(2) To the problems existed in the valve train, some measures and approaches of cam design are put forward. Taking the increasing of the intake valve fullness factor as the main goal of optimization, the the thickness of lubrication of the exhaust cam and tappet as a dynamic optimization objective function of the design. Then use the minimal optimization method to establish the design model of dynamic optimization.(3) Contrasting actual data to verify the validity of simulation and the feasibility of the design optimization. Proposing the Principle and methodology of verifiying feasibility of simulation and the effectiveness of the optimization of design. This paper State the principle, Process and outcome analysis of cam wear testing. By contrasting the theoretical values and the Measured values, we come to the conclusion eventually: simulation method is feasible and optimal design method is effective.