Patent ID: 6993909
Filing Date: 2006-02-07
Classification: F02D,F02M,Y02T

Abstract:
1. An EGR-gas temperature estimation apparatus for an internal combustion engine which has an exhaust circulation pipe connected between an exhaust passage and an intake passage, an EGR control valve interposed in the exhaust circulation pipe and adapted to control flow rate of EGR gas flowing through the exhaust circulation pipe, and an EGR-gas cooling apparatus interposed in the exhaust circulation pipe, the EGR-gas temperature estimation apparatus comprising: means for obtaining a temperature of the EGR gas on an inlet side of the EGR-gas cooling apparatus; means for obtaining a corresponding value corresponding to the flow rate of the EGR gas flowing through the exhaust circulation pipe; cooling efficiency obtaining means for obtaining a cooling efficiency of the EGR-gas cooling apparatus on the basis of the EGR-gas temperature on the inlet side of the EGR-gas cooling apparatus and the obtained corresponding value; and outlet EGR-gas temperature estimating means for estimating a temperature of the EGR gas on an outlet side of the EGR-gas cooling apparatus, on the basis of the EGR-gas temperature on the inlet side of the EGR-gas cooling apparatus and the obtained cooling efficiency.