| 摘要 |
PROBLEM TO BE SOLVED: To ensure the reliability of a pressure limiter by eliminating instability in idle performance caused by repeating the opening/closing of a pressure limiter. SOLUTION: When fuel is excessively discharged from a high pressure supply pump to a common rail caused by an abnormality in opening of an inlet metering valve and an abnormal increase in common rail pressure is detected, the setting of a target idle speed is changed to an abnormal value higher than a normal vale, that is, an idling speed is increased. Therefore, the discharge performance of a high pressure supply pump rotationally driven by a multicylinder engine is improved so as to prevent the pressure limiter, in which common rail pressure has exceeded limit set pressure to open the pressure limiter, from being closed again. Accordingly, instability in idle performance caused by repeating opening/closing the pressure limiter is eliminated, and at the same time, the reliability of the pressure limiter is ensured. |
