Catalyst converter breakdown inspecting method for internal combustion engine, involves blocking fuel injection to cylinder when measured converter temperature, which depends on exhaust gas temperature in converter, exceeds threshold value

摘要

The method involves detecting misfire, and measuring temperature of a catalyst converter based on an exhaust gas temperature in the converter. The exhaust gas temperature is computed based on a mathematical equation, and the measured catalyst converter temperature is evaluated. The injection of the fuel into a cylinder is blocked if the measured temperature exceeds a specific threshold value. The mathematical equation is TEMPCATMIS = (1-MISFIRERATE)x TEMPCAT+ MISFIRE-RATE x(TEMPCATMAX/cp) eta KatU+delta ANF. TEMPCATMIS refers to catalyst temperature, MISFIRERATE refers to ignition misfire rate, TEMPCAT refers to catalyst bed temperature, TEMPCTMAX refers to maximum catalyst temperature, cp refers to specific thermal capacity, eta KatU refers to efficiency of converter, delta ANF refers to temperature reduction due to ignition misfires. Independent claims are also included for the following: (A) a controller for inspecting breakdown of a catalyst converter (B) a computer program product with instructions for inspecting breakdown of a catalyst converter (C) a process for controlling an internal combustion engine.