Valve timing control apparatus

A valve timing control apparatus for controlling valve timing of a valve that is opened or closed by a camshaft through torque transmitted from a crankshaft in an engine of a vehicle, the valve timing being controlled using a working fluid supplied from a supply source in synchronization with a rotation of the engine, the valve timing control apparatus comprising:

• a housing that is rotatable with the crankshaft;
• a vane rotor that is rotatable with the camshaft, the vane rotor having vanes partitioning an inside of the housing into plural operation chambers in a rotating direction, the vane rotor having a rotation phase with respect to the housing, the rotation phase being changed by working fluid flowing into or out of the operation chambers;
• a lock portion to lock or unlock the rotation phase, the lock portion having an unlock chamber communicating with a predetermined operation chamber that is one of the operation chambers, the rotation phase being unlocked when a pressure of the working fluid flowing into the unlock chamber from the predetermined operation chamber is raised;
• a controller including a control valve having a spool;
• and
• the controller configured to perform an initial control and a normal control, the controller controlling working fluid to intermittently flow into the predetermined operation chamber in the initial control, the controller controlling the rotation phase to be changed by controlling working fluid to flow into or out of the operation chambers in the normal control, wherein
• the controller executes the initial control in a state where the rotation phase is locked by the lock portion, and the rotation phase is unlocked by the lock portion when the initial control is completed,
• the controller drives the spool to an advance position such that working fluid supplied from a supply source flows into the predetermined operation chamber and that working fluid is discharged from an opposite operation chamber opposite from the predetermined operation chamber,
• the controller drives the spool to a retard position such that working fluid supplied from the supply source flows into the opposite operation chamber and that working fluid is discharged from the predetermined operation chamber,
• the controller alternately and repeatedly drives the spool between the advance position and the retard position in the initial control,
• the controller starts the initial control immediately after the engine is activated, and
• the controller switches the initial control into the normal control after the initial control is finished.