VARIABLE VALVE DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

A variable valve device (20) equipped with a hydraulically actuated variable mechanism (25) that changes the valve timing, and a lock mechanism (26) that locks the valve timing during a prescribed period between the most retarded angle period and the most advanced angle period. The lock mechanism (26) has an advanced angle restriction mechanism and a retarded angle restriction mechanism, and the valve timing is mechanically locked for a prescribed period by means of the cooperation of these mechanisms. The advanced angle restriction mechanism and the retarded angle restriction mechanism each have a release chamber to which operating oil is supplied to control the operations of said mechanisms. The restriction mechanisms are constructed such that the supply/discharge of operating oil for their respective release chambers is controlled by a common OCV (62), and such that the release oil pressure for the advanced angle restriction mechanism and the release oil pressure for the retarded angle restriction mechanism differ.