Low Torque Engine Valve System Using Conical Coil Spring and Electromagnetic Actuator

Abstract

In this research, a new type valve system using a conical coil spring and an electromagnetic actuator was developed. This system uses a conical coil spring whose spring constant is low, and therefore, the valve system has a low torque in a low-speed rotation mode. As a result, the energy loss in a low-speed rotation is decreased. However, the jump and bounce phenomena would happen in the high-speed rotation mode. The phenomena are suppressed by using an electromagnetic actuator consisting of two permanent magnets and electromagnet. The electromagnetic actuator strengthens the restoration force of the spring by the repulsive force, and controls the jump and bounce phenomena. It was confirmed that the use of a conical coil spring lessened the load torque in this experiment and that the jump and bounce phenomena were suppressed by using the present electromagnetic actuator.