| 摘要 |
PROBLEM TO BE SOLVED: To obtain a temperature detection device for exhaust gas sensors which enables correct temperature detection and outputs a deterioration warning to a large change with respect to time of an internal resistance value. SOLUTION: In the device, there are provided an exhaust gas sensor 2 for detecting a concentration of oxygen included in an exhaust gas of an internal combustion engine, a temperature sensor 6 for measuring environment temperature which is substantially equivalent to a temperature of the exhaust gas sensor 2, a resistance value measuring means 12 for measuring the internal resistance value of the exhaust gas sensor 2, a timer means 6 for measuring a driving stoppage period of the internal combustion engine, and a control means 8 for detecting the internal resistance value, and the environment temperature of the exhaust gas sensor 2 for every driving start time point, when the driving stop period by the timer means 10 is not smaller than a predetermined value, operating, updating and storing an internal resistance value-temperature characteristic of the exhaust gas sensor 2 from the detected internal resistance value and environment temperature, and also calculating the temperature of the exhaust gas sensor 2 from the internal resistance value measured, while the exhaust gas sensor 2 is driving and the internal resistance value-temperature characteristic. |
