Patent attributes
A variable valve timing control apparatus of an internal combustion engine has a drive rotary member rotated by an engine crankshaft, a driven rotary member fixedly connected to a camshaft and transferring a turning force from the drive rotary member to the camshaft, and a phase-change mechanism changing a relative rotational phase between the drive and driven rotary members and having an intermediate rotary member installed between the drive and driven rotary members for a relative rotational phase control. The variable valve timing control apparatus further has a holding mechanism and a releasing mechanism. The holding mechanism forces the intermediate rotary member and holds the relative rotational phase between the drive and driven rotary members, and the releasing mechanism releases a holding state of the holding mechanism.
