Valve timing control system for internal combustion engine

A system for controlling a valve timing in an internal combustion engine, comprising:

• a driving rotator rotated by a crankshaft of the engine;
• a follower rotator provided to a camshaft of the engine, the follower rotator receiving power from the driving rotator;
• a radial guide provided to one of the driving rotator and the follower rotator;
• an intermediate rotator arranged rotatable with respect to the driving rotator and the follower rotator, the intermediate rotator comprising a spiral guide in a face opposite to the radial guide;
• a movable guide movably engaged with the radial guide and the spiral guide;
• a link which swingably couples another of the driving rotator and the follower rotator at a position distant from a center of rotation thereof to the movable guide;
• and
• means for providing to the intermediate rotator an operating force for rotation with respect to the driving rotator and the follower rotator, the providing means making radial displacement of the movable guide engaged with the spiral guide along the radial guide, the radial displacement being converted into relative rotation of the driving rotator and the follower rotator through the link,
• the movable guide comprising a main body supported by a front end of the link, an engaging part movably provided to the main body and engaged with the spiral guide, a biasing device which biases the engaging part to the spiral guide, and a restraining device which restrains, when backward displacement of the engaging part occurs against a force of the biasing device, the backward displacement within a range that the engaging part fails to be disengaged from the spiral guide.

An internal combustion engine, comprising:

• a crankshaft;
• a camshaft;
• a driving rotator rotated by the crankshaft;
• a follower rotator provided to the camshaft, the follower rotator receiving power from the driving rotator;
• a radial guide provided to one of the driving rotator and the follower rotator;
• an intermediate rotator arranged rotatable with respect to the driving rotator and the follower rotator, the intermediate rotator comprising a spiral guide in a face opposite to the radial guide;
• a movable guide movably engaged with the radial guide and the spiral guide;
• a link which swingably couples another of the driving rotator and the follower rotator at a position distant from a center of rotation thereof to the movable guide;
• and
• a device which provides to the intermediate rotator an operating force for rotation with respect to the driving rotator and the follower rotator, the device making radial displacement of the movable guide engaged with the spiral guide along the radial guide, the radial displacement being converted into relative rotation of the driving rotator and the follower rotator through the link,
• the movable guide comprising a main body supported by a front end of the link, an engaging part movably provided to the main body and engaged with the spiral guide, a biasing device which biases the engaging part to the spiral guide, and a restraining device which restrains, when backward displacement of the engaging part occurs against a force of the biasing device, the backward displacement within a range that the engaging part fails to be disengaged from the spiral guide.