Abstract: In an internal combustion engine having a hydraulic valve characteristic control mechanism for altering phase of a cam driving a suction valve and an oil pressure control valve for controlling pressure of working oil supplied to the valve characteristic control mechanism, a chain chamber comprising a case formed by an engine main body and a cover closing the case. The oil pressure control valve is attached to the engine main body surrounded by a timing chain. In order to position the oil pressure control valve outside of the chain chamber, the cover has an opening for inserting the oil pressure control valve and the case has an attachment section around the oil pressure control valve to which a whole marginal edge of the opening is touched in liquid-tight and fixed.

Abstract: In an oil passage system of a valve moving control apparatus for an internal combustion engine having a hydraulic valve phase variable mechanism and a hydraulic valve characteristic changing mechanism, an oil pressure changing valve for changing operation of the valve characteristic changing mechanism is attached to a rear surface on exhaust side of a cylinder head, and a working oil supply passage is disposed at the exhaust side of the cylinder head. A phase operating oil passage leading to an oil pressure control valve for controlling operation of the valve phase variable mechanism is connected with the working oil supply passage at a downstream position of a branching portion where a change operating oil passage leading to the oil pressure changing valve branches from the working supply passage. In the phase operating oil passage formed in the cylinder head, flow of the phase operating oil is reversed by a cover which is provided at a front surface on suction side of the cylinder head.