Patent ID: 8627793

Claim:
A control valve for use in a valve timing control apparatus having a housing adapted to be driven by a crankshaft of an internal combustion engine and configured to define a working fluid chamber therein, a vane rotor fixedly connected to a camshaft and rotatably accommodated in the housing so that the vane rotor rotates relative to the housing, the vane rotor having vanes configured to partition the working fluid chamber into a phase-advance chamber and a phase-retard chamber, a lock mechanism configured to be locked to enable the vane rotor to be held at an intermediate position between a maximum phase-advance position and a maximum phase-retard position, and configured to be unlocked by a working fluid pressure supplied thereto, a phase-advance passage configured to communicate with the phase-advance chamber, a phase-retard passage configured to communicate with the phase-retard chamber, and a lock passage provided for working-fluid-pressure supply-and-exhaust for the lock mechanism, comprising: a directional control valve configured to be switchable among a first position, a second position, a third position, and a fourth position, the first position being a position at which a discharge passage of a pump driven by the engine communicates with both the phase-advance passage and the phase-retard passage and simultaneously the lock passage communicates with a drain passage, the second position being a position at which the discharge passage communicates with both the phase-advance passage and the lock passage and simultaneously the phase-retard passage communicates with the drain passage, the third position being a position at which the discharge passage communicates with both the phase-retard passage and the lock passage and simultaneously the phase-advance passage communicates with the drain passage, and the fourth position being a position at which the discharge passage communicates with the lock passage and simultaneously the discharge passage communicates with both the phase-advance passage and the phase-retard passage through a flow passage area less than a given flow passage area obtained at the first position or fluid-communication between the discharge passage and each of the phase-advance passage and the phase-retard passage is blocked.