| 摘要 |
PROBLEM TO BE SOLVED: To provide a state detection device for an exhaust system, in which an exhaust gas temperature is effectively detected with a simple configuration.SOLUTION: A state detection device for an exhaust system, comprises: an intake oxygen concentration sensor 32 for detecting the intake oxygen concentration of an engine 10; an engine rotation sensor 30 and an accelerator opening sensor 31 for detecting an operational state; an indicated thermal efficiency operation unit 42 for calculating an indicated thermal efficiency changing amount of the engine 10 on the basis of a first model formula defining the relations between an intake oxygen concentration and the injection start timing of the fuel and among the intake oxygen concentration stored in advance, the injection start timing and the indicated thermal efficiency changing amount, and an exhaust temperature operation unit 43 for calculating the exhaust temperature of the engine 10 on the basis of a second model formula defining an indicated thermal efficiency changing amount and the relation between the exhaust temperature stored in advance and the indicated thermal efficiency changing amount. |
