Valve timing control apparatus

摘要

An assist spring is fixed at its one end to a vane rotor and at its other end to a spring hook provided at an outside of a housing 18. A signal plate is fixed to the vane rotor on a side of the spring hook. A cam angle sensor is provided at an outer peripheral side of the signal plate for detecting a rotational angle of the signal plate. The assist spring and the spring hook are arranged in an area, which is inside of an outer periphery of the signal plate in a radial direction, so that the cam angle sensor may not misidentify the assist spring and the spring hook and thereby exactly detects the rotational angle of the signal plate.