To provide a valve characteristic control device of internal combustion engine capable of suitably suppressing fluctuations in engine power outputs that are likely to occur, when switching a maximum lift quantity of an intake valve and a target value of valve opening time from a value according to an output requirement to another value, or when resetting the target value to the value according to the output requirement.

An electronic control apparatus 26 compensates change in valve opening timing of an intake valve 9 associated with the drive of a lift quantity variable mechanism 14 through the drive control of a valve timing variable mechanism 13. In addition, when the state of output requirement is within a region of output requirement that brings the valve closing timing of the intake valve 9 to a timing near an intake bottom dead point, the occurrence of knocking is suppressed by switching the target value. Then, when the state of output requirement is beyond the region of output requirement, the switched target value will be recovered. When a valve overlap quantity exceeds a predetermined range on the way of switching a valve opening time associated with such a switching and recovering of the target value, the drive of the lift quantity variable mechanism 14 will be stopped temporarily.

COPYRIGHT: (C)2008,JPO&INPIT