Patent ID: 7444971

Claim:
A valve timing control apparatus for an internal combustion engine, comprising: a driving rotator adapted to be rotated by a torque outputted from the internal combustion engine; a driven rotator arranged to rotate with a relative rotational phase with respect to the driving rotator and adapted to transmit the torque from the driving rotator to a camshaft of the internal combustion engine via working fluid in a torque transmission path; a camshaft-torque actuation mechanism including at least a first camshaft-torque actuation chamber and a second camshaft-torque actuation chamber arranged in the torque transmission path, the camshaft-torque actuation mechanism being configured to alter the relative rotational phase by providing selectively at least a state of allowing a unidirectional flow of working fluid from the first camshaft-torque actuation chamber to the second camshaft-torque actuation chamber and a state of allowing a unidirectional flow of working fluid from the second camshaft-torque actuation chamber to the first camshaft-torque actuation chamber; a hydraulic actuation mechanism inducing at least a first hydraulic actuation chamber and a second hydraulic actuation chamber arranged in the torque transmission path, the hydraulic actuation mechanism being configured to alter the relative rotational phase by providing selectively at least a state of supplying working fluid to the first hydraulic actuation chamber from outside and draining working fluid from the second hydraulic actuation chamber to outside and a state of supplying working fluid to the second hydraulic actuation chamber from outside and draining working fluid from the first hydraulic actuation chamber to outside; and a working fluid control section for controlling the camshaft-torque actuation mechanism and the hydraulic actuation mechanism, wherein the working fluid control section comprises: a first working fluid control section for controlling the camshaft-torque actuation mechanism; and a second working fluid control section for controlling the hydraulic actuation mechanism.