Honda Motor Co., Ltd.

Hiroaki Nishino

Eisaku Gosyo

Kiyoshi Saito

Hidetaka Maki

Daisuke Sato

Jun Iida

Eisaku Gosho

An exhaust gas purifying apparatus for an internal combustion engine, including a particulate filter provided in an exhaust passage of the engine; a pressure difference sensor for detecting a pressure difference between upstream and downstream side pressures of the particulate filter; an upstream side passage, which connects the pressure difference sensor and an upstream side with respect to the particulate filter of the exhaust passage; and a downstream side passage, which connects the pressure difference sensor and a downstream side with respect to the particulate filter of the exhaust passage. An exhaust gas flow rate is calculated according to an operating condition of the engine. A characteristic of change in the pressure difference, which is detected by the pressure difference detector and corresponds to a change in the exhaust gas flow rate, is detected. An abnormality of the downstream side passage is determined based on the characteristic of change in the pressure difference.

Exhaust gas purifying apparatus for internal combustion engine

A particulate filter is provided in an exhaust system of the engine. Parameter values correlated with a flow amount of exhaust gas of the engine are determined, and differential pressure between upstream and downstream sides of the particulate filter is determined. The ratio of a variation rate of the parameter values correlated with the exhaust flow amount to a variation rate of the differential pressure is compared with a predetermined threshold value during transitional operation of the engine to determine the state of the particulate filter.

Apparatus for detecting a state of a particulate filter

Deterioration of a catalyst provided in an exhaust system of the engine is determined. Air-fuel ratio sensors are provided in the upstream side and the downstream side of the catalyst. Air-fuel ratio is changed. Based on the sensor outputs in the upstream die and the downstream side of the catalyst, a parameter of a catalyst model representing a state of the catalyst is identified. The parameter is compared with a threshold to determine a state of the catalyst.

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Saitama, Japan

Hiroaki Nishino