Patent ID: 8635988

Claim:
A variable valve device for an internal combustion engine comprising; a cam phase variable mechanism in which each cylinder includes a first intake valve driven by a first intake cam and a second intake valve driven by a second intake cam, the mechanism being capable of varying a phase of the second intake cam relative to the first intake cam, and a phase variable control unit that controls the cam phase variable mechanism, wherein: the cam phase variable mechanism is formed by turnably disposing an inner camshaft in an outer camshaft formed of a pipe, has a intake camshaft that can be driven by crank output of the internal combustion engine, is provided with the first intake cam in a peripheral area of the outer camshaft, is provided with the second intake cam so as to be turnable around an axis of the outer camshaft, and varies the phase of the second intake cam on the basis of the first intake cam at a relative displacement of the outer and inner camshafts; and under predetermined operating conditions of the internal combustion engine, the phase variable control unit varies the phase of the second intake cam relative to the first intake cam such that the second intake cam takes a phase which is within a predetermined pumping-loss reduction operation phase range ensuring reduced pumping losses, the second intake cam is set in the predetermined pumping-loss reduction operation phase range by a predetermined phase that the driving torque of the intake camshaft becomes smallest.