Current Situation and Development of Variable Technology for Valve Timing

Variable control for valve timing is one of the important issue for development of automobile technology. At present, Various device of variable valve timing have been used for the automobile engine. These variable valve timing devices are mechanical? hydraulic pressure, compounding mechanical and hydraulic pressure, electrodynamic, etc. This paper introduces the structure and the characteristics of various technology for the variable valve timing, which have to be used on the modern automobile engine. The excellence and the problem of electric valve for variable valve timing control are analyzed. It is pointed out that the electric valve used for automobile engine for variable valve timing is the development trend.