Variable valve timing controlling apparatus for internal combustion engine

Abstract

In a variable valve timing controlling apparatus for an internal combustion engine having an engine valve, the controlling apparatus having:a rotational body rotated in synchronization with an engine crankshaft;a camshaft, one end thereof being inserted into the rotational body and the camshaft including a cam located on an outer periphery of the camshaft to open the engine valve against a spring force exerted by a valve spring of the engine valve; a phase changing device interposed between the rotational body and the one end of the camshaft to hydraulically vary a relative rotational phase between the rotational body and the camshaft; and a hydraulic pressure circuit to relatively supply and drain a hydraulic pressure to and from at least one retardation angle hydraulic pressure chamber and at least one advance angle hydraulic pressure chamber, each hydraulic pressure chamber being formed within the rotational body to drive the cam phase changing device, an interrupting mechanism is provided to interrupt a hydraulic pressure passage of the hydraulic pressure circuit to supply the hydraulic pressure to at least one of the advance angle and retardation angle hydraulic pressure chambers for a time duration which corresponds to a torque peak region of a rotation variation torque developed on the camshaft.

Dependencies are inferred from the claim text.