AIR FUEL RATIO DETECTING DEVICE

• Main Authors: OOSUGA MINORU, OOYAMA TAKASHIGE
• Format: Patent
• Language: English
• Published: 15.08.1984
• Subjects: BLASTING; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; LIGHTING; MEASURING; MECHANICAL ENGINEERING; PHYSICS; TESTING; WEAPONS

PURPOSE:To improve responsiveness of a device, and to execute an exact air fuel ratio control by performing a correcting processing to a sensor output, basing on a variation signal component in the sensor output based on an hourly variation of an air fuel ratio. CONSTITUTION:Constant voltage V0 is applied between electrodes 21a and 21b in a sensor part 20, from a power source 23, a threshold current I0 corresponding to an air fuel ratio flows to a resistance R20, and this current is detected voltage V as both terminals of the resistance R20, and supplied to a low frequency portion detecting circuit 30 and a high frequency portion detecting circuit 31. Subsequently, in an operating circuit 32, low frequency portion output voltage V10 of the circuit 30 is inverted and amplified, the sum with high frequency portion voltage DELTAV1 held in the circuit 31 is further amplified, and its output becomes (V10-K.DELTAV1). In this case, a correcting coefficient K can be selected suitably by selecting suitably value of input resistances R1, R2 in the operating circuit 32.