Method of controlling an electric valve drive device and a control

Abstract

A poppet valve which has a valve stem is moved up and down to open and close a valve port in an internal combustion engine of a vehicle such as an automobile. A moving coil is wound on a bobbin mounted to the valve stem, and a magnet is mounted to a yoke fixed to a cylinder head. A plurality of sensors detect working conditions of the engine to send a signal to a working condition discriminating portion of CPU. The signal is further sent to a valve timing lift pattern memory in which optimum valve timing and lift are set corresponding to the working conditions to generate an optimum valve position signal. In the meantime, an actual position of the valve is detected by a sensor on the yoke to send an actual valve position signal to a valve position detector. In a comparator, the actual valve position signal from the valve position detector is compared with the optimum valve position signal from the valve timing lift pattern memory to apply to an electric current to the moving coil to move the valve up and down so that difference between the two signals may not occur.