Patent ID: 6957527
Filing Date: 2005-10-25
Classification: F01N,F02D,Y02T

Abstract:
1. A device for periodically estimating a temperature of an exhaust-gas purifying catalyst provided in an exhaust pipe of an internal combustion engine, comprising: first estimation means for estimating a temperature of exhaust gases that are discharged from a combustion chamber of said internal combustion engine, as a steady catalytic temperature under a steady operation of said internal combustion engine, based on operating conditions of said internal combustion engine; second estimation means for estimating a representative temperature of an interior wall of said exhaust pipe extending from said internal combustion engine to said catalyst, based on said steady catalytic temperature estimated by said first estimation means; third estimation means for estimating a catalyst inflow exhaust-gas temperature that flows in said catalyst, based on said steady catalytic temperature estimated by said first estimation means and said representative temperature of an interior wall of said exhaust pipe estimated by said second estimation means; and fourth estimation means for estimating the temperature of said catalyst based on said catalyst inflow exhaust-gas temperature estimated by said third estimation means.