Engine valve timing control apparatus

Abstract

To achieve an intermediate lock state in a short period when an engine is stopped and improve the accuracy of confirmation of the intermediate lock state, an engine valve timing control apparatus includes a variable valve timing mechanism configured to vary engine valve timing, and an intermediate lock mechanism configured to restrict relative rotation positions of a first and a second rotor of the valve timing mechanism at an intermediate lock position for starting the engine. Upon detection of an engine stop request, the valve timing mechanism and the intermediate lock mechanism are driven and controlled for establishing an intermediate lock state. When a predetermined period from detection of the engine stop request has expired without detecting the intermediate lock state within the predetermined period, an engine stopping process is executed. Even after the engine stopping process has been executed, monitoring of the intermediate lock state is continued.