| 摘要 |
Where a relationship between maximum heat release rate timing (¸dQpeak) and a first combustion period length (aref) (that is, a reference relationship) in the case where an engine rotation speed (NE) of a spark-ignition internal combustion engine is a selected speed (NEO) and a valve opening characteristic of an intake valve is a reference characteristic is expressed by the function aref = f(¸dQpeak), when the valve opening characteristic of the intake valve changes to a specific characteristic from this state, a first combustion period length (a) for selected maximum heat release rate timing (¸2) is estimated on the basis of the mathematical expression a = f(¸2) + ”a1. |
