Air-fuel ratio controller

Abstract

Abstract PURPOSE:To provide close correlation between a smoothed suction air amount signal and an exhaust temperature, to control the applying voltage of a heater in response to the signal, and to improve performance and durabilty of a device, serving as a O2 sensor, through maintenance of a part of the sensor part at a specified temperature, by mounting means for smoothing a signal from means for detecting the amount of the air sucked. CONSTITUTION:A smoothing circuit 23, serving as a smoothing means, smoothes a suction air amount signal Qa. Further, in order to activate a sensor part through increase of the applying voltage of a heater even during the starting of an engine, a water temperature sensor 26 and a control circuit 22C are mounted. A comparator 27 compares a water temperature signal TW with a reference value C3. The reference value C3 is previously determined based on temperature during cooling of the engine. When the temperature of cooling water is below the reference value C3, a high level signal is outputted, and when exceeding the reference value, a low level signal is outputted. When a comparator 14 or the comparator 27 is at a high level, an OR circuit 28 outputs a high level signal. When the suction air amount signal Qa is smoothed, the signal has close correlation with the temperature of exhaust gas.

Inventors

• 👤 Takeshi Kitahara
• 👤 剛 北原
• 👤 Kimitake Sone
• 👤 曽根　公毅

Bibliographic Details