Patent ID: 6192678
Filing Date: 2001-02-27
Classification: F01N,Y02T

Abstract:
A secondary air supply control system for an internal combustion engine including an exhaust passage, and a catalyst arranged in said exhaust passage, for purification of exhaust gases, the secondary air supply control system controlling supply of air to said catalyst, and comprising:air supply means for supplying air to said catalyst;engine coolant temperature-sensing means for sensing a temperature of an engine coolant within said engine;intake air temperature-sensing means for sensing a temperature of intake air within said engine;operation time-determining means for determining an operation time period over which said air supply means is to be operated;storage means for storing therein a value of said temperature of said engine coolant sensed by said engine coolant temperature-sensing means at a stoppage of said engine;arithmetic operation means for calculating a temperature difference between said value of said temperature of said engine coolant sensed at said stoppage of said engine and stored in said storage means and a value of said temperature of said engine coolant sensed at a start of said engine after said stoppage of said engine;determination means for determining whether or not a stop time period between said stoppage of said engine and said start of said engine is short, depending on said temperature difference calculated by said arithmetic operation means; andoperation time-correcting means for correcting said operation time period, based on a temperature difference between said value of said temperature of said engine coolant sensed at said start of said engine and a value of said temperature of said intake air sensed at said start of said engine, when said determination means determines that said stop time period is short.