| 摘要 |
With an EGR rate estimation method using the opening size of an EGR valve, the EGR rate estimation accuracy deteriorates as the EGR valve worsens, and when the target EGR rate is high, the accuracy demanded cannot be achieved. In addition, with a method for correcting an injection amount with respect to a fuel injection valve by estimating a purge air-fuel ratio from the change in air-fuel ratio occurring when purging is performed or not performed, when the concentration of fuel evaporation gas adsorbed on activated carbon within a canister is high, fuel injection correction cannot keep up with the change in the air-fuel ratio, and the conversion efficiency of a catalyst decreases. An intake pipe of the present invention has an introduction port at which gas other than new air flows into the intake pipe. Humidity sensors are provided on the upstream and downstream of the introduction port, and the purge air-fuel ratio or the EGR rate inside the intake pipe is estimated by using sensor values obtained from the respective humidity sensors. |
