Valve timing adjusting apparatus

A valve timing adjusting apparatus for an internal combustion engine having a camshaft and a crankshaft, wherein the valve timing adjusting apparatus uses hydraulic oil supplied from a supply source to adjust valve timing of a valve that is opened and closed by the camshaft through torque transmission from the crankshaft the valve timing adjusting apparatus comprising:

• a housing that is rotatable synchronously with the crankshaft;
• a vane rotor that is rotatable synchronously with the camshaft, wherein:
• the vane rotor has a vane that defines an advance fluid chamber and a retard fluid chamber that are arranged in the housing in a circumferential direction such that a rotational phase of the vane rotor relative to the housing is changed in an advance direction or in a retard direction when hydraulic oil supplied by the supply source is introduced into a corresponding one of the advance fluid chamber and the retard fluid chamber;
• a fluid path arrangement that is provided inside the housing, wherein:
• the fluid path arrangement opens to air outside the housing;
• the fluid path arrangement is communicated with a specific fluid chamber that is one of the advance fluid chamber and the retard fluid chamber;
• and
• the rotational phase is changed in a predetermined one of the advance and retard directions when hydraulic oil is introduced into the specific fluid chamber;
• and
• opening-closing control means for controlling the fluid path arrangement to be opened and closed.