Hybrid electro-mechanical latching device for variable valve timing

This paper presents a new electro-mechanical latching device for variable valve timing of automotive engine. One of the most promising ways to improve fuel economy, reduce CO2 emissions and increase torque output is to achieve variable valve timing (VVT) which need flexible valve actuating device instead of conventional cam operated valve train. We propose hybrid electro-mechanical latching device which has stability of conventional cam operated valve train and flexibility of electrically operated valve train. By controlling the motion of latch, it has three different modes such as normal mode, deactivation mode and VVT mode. To demonstrate dynamic characteristics of the proposed system, finite element analysis is performed and the prototyped device is constructed. The experimental results show the possibility of the proposed design to be adapted in practical use to replace the conventional cam operated engine valve at the normal engine speed.