| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a valve timing adjustment system capable of suppressing damage of an engine.SOLUTION: In a valve timing adjustment system 5, relative rotations of a cup 15 and a vane rotor 30 are mechanically limited by basic limiting means 40 so that rotational phase difference is kept within a base angle range. An electronic control device 75 determines a target value of the rotational phase difference within a regulation angle range smaller than the base angle range, when it is determined that the rotational phase difference is outside of the base angle range. Accordingly, for example, when the rotational phase difference of the cup 15 and the vane rotor 30 is outside of the base angle range due to fracture of the basic limiting means 40, the electronic control device 75 quickly controls the rotational phase difference within the regulation angle range smaller than the base angle range. Thus the damage of the engine 90 caused by contact of valves to each other and occurence of abnormal combustion when the rotational phase difference is outside of the base angle range, can be suppressed.</p> |
