| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of noise generation caused by the blow-back of exhaust by suppressing an increase in a valve overlapping amount caused by a follow-up delay of actual valve timing to a control target value even in an operation state that a rotation change is high upon shifting.SOLUTION: When it is determined that shift-up from a second gear to a third gear is permitted and shift instruction is outputted, engine speed is remarkably changed and a control target of valve timing is changed to a value corresponding to the rotation change upon shifting. In such a case, if normal valve timing control is still used, a variable valve timing mechanism cannot be mechanically followed to the control target value to cause the delay of actual valve timing and an actual valve overlapping amount is increased to increase the blow-back of the exhaust to generate a vibration sound. Then, the blow-back of the exhaust caused by an increase in a valve overlapping amount is suppressed to avoid the noise by limiting the control target value with a preset guard value. |
