US 2003/0196428 A1 · Exhaust gas purifying system for internal combustion engines

Abstract

A first oxygen sensor is mounted on an exhaust pipe. An ECU determines an electric power to be fed to a sensor heater, by a heater control quantity calculating block, in accordance with a difference between an actual impedance and a target impedance calculated by a running condition determining block and a specific gas sensitivity priority determining block. As a result, the detection sensitivity of the oxygen sensor to a rich component or a lean component is improved according to the running condition. This improved output is detected by an output detecting block and reflected on the air/fuel ratio control so that an air/fuel ratio is controlled thereby.

Claims20

Dependent claims

An exhaust gas purifying system for an internal combustion engine comprising:

air/fuel ratio detecting means made by arranging an electrode at a solid electrolyte element, for detecting an air/fuel ratio in an exhaust gas coming from an engine;
temperature adjusting means for adjusting a temperature of the solid electrolyte element in the air/fuel ratio detecting means to a predetermined temperature;
and
priority determining means for determining such a specific gas in the exhaust gas as to have priority insensitivity,
wherein the temperature adjusting means adjusts the temperature of the solid electrolyte element so as to change the detection sensitivity to the specific exhaust gas determined by the priority determining means.

2 more elements

Dependencies are inferred from the claim text.

Exhaust gas purifying system for internal combustion engines

Life of this patent

Exhaust gas purifying system for internal combustion engines

Life of this patent

Abstract

Claims20