| 摘要 |
PROBLEM TO BE SOLVED: To perform a well-efficient estimation of duration of a former half combustion period of an internal combustion engine whose valve opening characteristic of an intake valve can be changed in a various manner.SOLUTION: When "relation between a heat generation rate maximum period θdQpeak and a duration of a former half combustion period aref (i.e. reference relation)" in a case in which an engine speed NE of a spark ignition type internal combustion engine is an arbitrary speed NE0 and a valve opening characteristic of an intake valve is a reference characteristic is expressed by a function aref=f(θdQpeak), a duration [a] of the former half combustion period in respect to an arbitrary heat generation rate maximum timing θ2 is estimated on the basis of an equation of "a=f(θ2)+Δa1" when a valve opening characteristic of the intake valve is changed from this state to a specific characteristic. In this case, Δa1 defines a difference value between a duration [ad1] of the former half combustion period when the heat generation rate maximum period θdQpeak is a reference timing θ1 and a duration [ar1] of the former half combustion period when the valve opening characteristic of the intake valve is a reference characteristic and the heat generation rate maximum timing θdQpeak is the reference timing θ1.SELECTED DRAWING: Figure 1 |
