| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of abnormal combustion due to change of property of a fuel in a high EGR operation more easily at a lower cost in comparison with a conventional one.SOLUTION: When a reference fuel 21 of a cetane value A is stored in a fuel tank 18, a first step for calculating an EGR rate on the basis of measurement values of an intake air amount sensor 7, an intake manifold temperature sensor 9, an intake manifold pressure sensor 10, and an exhaust Osensor 12, a second step for determining an integrated value of a detection value of a vibration acceleration sensor 3 within a range of a predetermined crank angle when the EGR rate is a predetermined threshold value P or more, and a third step for executing the second step by every combustion cycle and calculating an average value X of their integrated values, are successively executed. On the other hand, when a comparison fuel 21 of a cetane value B is supplied, the average value Y is calculated by successively executing the first to third steps, and an injection timing in an injector 20 is adjusted on the basis of the difference of the average values, and map data.SELECTED DRAWING: Figure 1 |
