Patent ID: 7500455

Claim:
A valve timing control apparatus of an internal combustion engine, which controls valve timing of at least one of an intake valve and an exhaust valve that are opened and closed by a camshaft driven by a torque transmitted from a crankshaft, the valve timing control apparatus comprising: a first rotator that is rotated synchronously with the crankshaft; a second rotator that is rotated synchronously with the camshaft; a guide rotator that has a guide groove, which is elongated and has a predetermined width; a movable body that is guided in the guide groove in a direction of elongation of the guide groove to move toward or away from a rotational axis of the guide rotator in response to rotation of the guide rotator; and a link mechanism that is coupled with the first rotator, the second rotator and the movable body to change a relative rotational phase between the first rotator and the second rotator in response to movement of the movable body, wherein: the movable body has a cylindrical outer peripheral surface; and the guide groove includes: a stopper surface that is planar and is positioned in one of two opposed ends of the guide groove, which are opposed to each other in the direction of elongation of the guide groove, wherein the stopper surface is engageable with the cylindrical outer peripheral surface of the movable body in the direction of elongation of the guide groove to stop the movable body; an outer guide surface that is slidably engageable with the cylindrical outer peripheral surface of the movable body to guide the movable body and that is positioned on a radially outer side of the movable body in a radial direction of the guide rotator; an arcuate outer connection surface that connects between the stopper surface and the outer guide surface and has a radius of curvature, which is smaller than that of the cylindrical outer peripheral surface of the movable body; an inner guide surface that is slidably engageable with the cylindrical outer peripheral surface of the movable body to guide the movable body and that is positioned on a radially inner side of the movable body in the radial direction of the guide rotator; and an arcuate inner connection surface that connects between the stopper surface and the inner guide surface and has a radius of curvature, which is smaller than that of the cylindrical outer peripheral surface of the movable body.