Patent ID: 8281756

Claim:
A valve timing control apparatus comprising: a driving-side rotating member synchronously rotatable with a crankshaft of an internal combustion engine; a driven-side rotating member arranged coaxially with the driving-side rotational member so as to be rotatable relative to the driving-side rotating member and integrally rotatable relative to a camshaft that controls opening and closing operations of a valve of the internal combustion engine; a retarded angle chamber defined by the driving-side rotating member and the driven-side rotating member, the retarded angle chamber used for changing a relative rotational phase of the driven-side rotating member relative to the driving-side rotating member in a retarded angle direction in a manner where a volume of the retarded angle chamber is changed; an advanced angle chamber defined by the driving-side rotating member and the driven-side rotating member, the advanced angle chamber used for changing the relative rotational phase of the driven-side rotating member relative to the driving-side rotating member in an advanced angle direction in a manner where a volume of the advanced angle chamber is changed; a lock mechanism locking the relative rotational phase of the driven-side rotating member at a predetermined phase between a most advanced angle phase and a retarded angle phase; an operation fluid supply-and-discharge mechanism supplying and discharging an operation fluid to and from the retarded angle chamber, the advanced angle chamber and the lock mechanism; and a first air inlet mechanism for connecting one of the retarded angle chamber and the advanced angle chamber to an outside of the valve timing control apparatus in order to allow air to flow into the one of the retarded angle chamber and the advanced angle chamber; wherein the first air inlet mechanism includes an atmosphere communication passage for connecting an opening portion opened to the outside of the valve timing control apparatus with the one of the retarded angle chamber and the advanced angle chamber, a valve guiding bore formed at the driving-side rotating member so as to extend in a radial direction of the driving-side rotating member and so as to intersect with the atmosphere communication passage, and an on-off valve slidably accommodated within the valve guiding bore so as to move in the radial direction in response to the rotational speed of the driving-side rotating member in order to open and close the atmosphere communication passage; wherein the opening portion is arranged coaxially with the atmosphere communication passage.