DESIGN OF A NEW ELECTROMAGNETIC VALVE WITH A HYBRID PM/EM ACTUATOR IN SI ENGINES

Numerous devices have been developed for controlling valve timings in SI engines. Among them, the electromagnetic valve train (EMV) actuator can fully control valve timings to improve fuel consumption and emission. In addition, an EMV with a permanent-magnet and electromagnetic-coil (PM/EM) hybrid actuator has several advantages of control, energy consumption, and time response compared over conventional EMVs. This paper proposes a novel EMV with a PM/EM hybrid actuator that differs considerably from existing EMVs. Finite element analysis was used for analyzing the EMV design. The optimization was based on criteria that ensured the EMV to satisfy holding forces in closed and open states at high speed in SI engines. Several parameters such as PM, armature dimensions, and electromagnetic coil sizes were analyzed. The results indicated that the EMV satisfies the required space limit. Furthermore, the optimal EMV design also matches the transition time and holding force. A holding force of approximately 719 N is created when the desired current is supplied to the coils, and the efficiency of the force dropped by 42.22%. Therefore, the EMV can fully control the timings of the closed and open valves at high speed in SI engines.