| 摘要 |
PURPOSE:To ensure stabilized detection accuracy of air-fuel ratio by controlling the conduction amount of a heater basing on the temperature of exhaust gas corresponding to an operating condition detected by an operating condition detecting means thereby sustaining the temperature of elements in an air-fuel ratio sensor at a constant level. CONSTITUTION:The temperature controller comprises an air flowmeter 10 for detecting the intake air flow of an engine, a crank angle sensor 11 for taking a rotation signal from a crankshaft or a camshaft, and an air-fuel ratio sensor 12 incorporating a heater for detecting the air-fuel ratio of the intake fuel-air mixture over a wide range through the concentration of oxygen in the exhaust gas. A control unit 16 controls conduction of the heater by increasing or decreasing the rated applying voltage, for example, depending on the temperature of exhaust gas being determined by an operating condition detected by the operating condition detecting means. This constitution sustains the temperature of elements of the air-fuel ratio sensor 12 substantially at a constant level regardless of the variation of the exhaust gas temperature due to variation of the operating condition. |
