In this study, optimum cam profile and valve train components are designed for improving dynamic characteristics of an OHC-type cam valve train. Since the performance of engine is greatly affected by the valve train motion, it is required to design a valve mechanism properly adequate to maintain valve motion and to reduce noise, wear.. etc.
First, a 6 degree of freedom lumped parameter model is adopted for an OHC-type cam valve train, and the effects of each design variable on the performances of valve train are studied. While maintaining current valve flow area and minimum contact force, valve train components are designed as to minimize the maximum contact force between cam and follower. Also, optimum cam profile is designed through the same way as the valve train design. For the designed and original cam, valve train motion was experimentally measured and compared. From the experiments, it is found that the maximum contact force can be reduced greatly while maintaining current valve flow area.