Valve timing control apparatus of internal combustion engine

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 a torque transmission path;
• a camshaft-torque actuation mechanism including at least a pair of camshaft-torque actuation chambers arranged in the torque transmission path, the camshaft-torque actuation mechanism being configured to alter the relative rotational phase by providing at least a state allowing a unidirectional flow of working fluid from one of the camshaft-torque actuation chambers to another of the camshaft-torque actuation chambers;
• and
• a hydraulic actuation mechanism including at least a pair of hydraulic actuation chambers arranged in the torque transmission path, the hydraulic actuation mechanism being configured to alter the relative rotational phase at least by supplying and draining working fluid to and from one of the hydraulic actuation chambers,
• a first rate of flow with respect to alteration in the relative rotational phase, at which working fluid flows from the one of the camshaft-torque actuation chambers to the another of the camshaft-torque actuation chambers in accordance with the alteration in the relative rotational phase, being higher than a second rate of flow with respect to the alteration in the relative rotational phase, at which working fluid flows from and to the one of the hydraulic actuation chambers in accordance with the alteration in the relative rotational phase.

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;
• a vane member formed in one of the driving rotator and the driven rotator, the vane member including a first vane set and a second vane set;
• a plurality of shoes formed in another of the driving rotator and the driven rotator;
• a camshaft-torque actuation mechanism including at least a pair of camshaft-torque actuation chambers defined by the first vane set and the shoes, the camshaft-torque actuation mechanism being configured to alter the relative rotational phase by providing at least a state allowing a unidirectional flow of working fluid from one of the camshaft-torque actuation chambers to another of the camshaft-torque actuation chambers;
• and
• a hydraulic actuation mechanism including at least a pair of hydraulic actuation chambers defined by the second vane set and the shoes, the hydraulic actuation mechanism being configured to alter the relative rotational phase at least by supplying and draining working fluid to and from one of the hydraulic actuation chambers,
• the second vane set having a larger total pressure-receiving area than the first vane set.