| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve timing device with an intermediate lock mechanism capable of locking a camshaft phase at a lock position being substantially an intermediate position in its adjustable scope when variable valve timing control is not performed to make amount of control when controlling lock release proper and release locking speedily. SOLUTION: In this variable valve timing controller, amount of control (hereinafter referred to as "amount of lock release control") of a hydraulic control valve is learned during lock release control. Amount of lock release control of the hydraulic control valve is compensated in the direction for facilitating lock release when locking cannot be released during lock release control. It is determined that improper lock release (lock fixation) occurs when locking cannot be released even if amount of lock release control of the hydraulic control valve is compensated during lock release control to control to hold a locking condition when it is determined that improper lock release occurs. When compensation of amount of lock release control of the hydraulic control valve is repeated for predetermined number of times or more during lock release control or amount of lock release control is out of a predetermined scope, it is determined that improper lock release occurs. COPYRIGHT: (C)2006,JPO&NCIPI |
