摘要 |
A variable valve timing control device includes a relative rotation control mechanism restricting relative rotation between the housing member and the rotor member at an intermediate phase position between a most advanced angle phase position and a most retarded angle phase position, and a hydraulic pressure circuit which controlling supply and discharge of operation fluid with respect to advance and retarded angle hydraulic chambers while also controlling supply and discharge of operation fluid for the relative rotation control mechanism. The hydraulic pressure circuit includes a variable type spool valve adapted to discharge the operation fluid from the advance and retarded angle chambers and from the relative rotation control mechanism. The variable type spool valve has different discharge opening widths at a both drain function region in which the operation fluid can be drained from the advanced and retarded angle hydraulic chambers.
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