Patent ID: 6868327
Filing Date: 2005-03-15
Classification: F02D

Abstract:
1. A device for estimating the amount of the intake air of an internal combustion engine comprising: intake pipe pressure calculation means for calculating an intake pipe pressure at this time downstream of a throttle valve, and intake air amount calculation means for calculating the amount of the intake air at this time based on said intake pipe pressure at this time calculated by said intake pipe pressure calculation means, wherein said intake pipe pressure calculation means calculating said intake pipe pressure at this time by using the intake pipe pressure calculated in the last time and the amount of the air passing through the throttle valve at the last time calculated by means for calculating the amount of the air passing through the throttle valve, and said device for estimating the amount of the intake air comprises; limitation means for replacing said intake pipe pressure at this time by the atmospheric pressure when said intake pipe pressure at this time calculated by said intake pipe pressure calculation means is higher than the atmospheric pressure, and correction means for correcting the amount of the air passing through the throttle valve at the last time based on the pressure differential between the atmospheric pressure and said intake pipe pressure calculated at the last time when said intake pipe pressure at this time is replaced by the atmospheric pressure by said limitation means.