Exhaust gas purifier for internal combustion engines
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorsYasuki Tamura, Kojiro Okada, Tomohiro Ohashi, Naoto Yamada, Kazuo Koga
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Abstract
An exhaust passage (20) of an internal-combustion engine (1) is provided with an exhaust emission control unit (40) capable of reducing harmful substances in exhaust gas under a given exhaust pressure condition and an exhaust sensor (22) for detecting the concentration of a specific exhaust component (H2, O2) in the exhaust gas, and a performance lowering identifying unit identifies lowering of the performance of the exhaust emission control (40) by detecting a failure to fulfill the given exhaust pressure condition in accordance with the output of the exhaust sensor.
Claims12
An exhaust emission control device of an internal-combustion engine, comprising:
- exhaust emission control means located in an exhaust passage of the internal-combustion engine and adapted to reduce harmful substances in exhaust gas under a given exhaust pressure condition;
- an exhaust sensor, provided in the exhaust passage and upstream of said exhaust emission control means, for detecting and outputting the concentration of a specific exhaust component in said exhaust gas at an upstream of the exhaust emission control means, the output of the exhaust sensor being also indicative of an actual exhaust gas pressure upstream of said exhaust emission control means, and said exhaust sensor being the only exhaust sensor provided in the exhaust passage;
- and
- performance lowering identifying means for identifying lowering of the performance of said exhaust emission control means by detecting a failure to fulfill said given exhaust pressure condition based on the output of said exhaust sensor.
An exhaust emission control device of an internal-combustion engine, comprising:
- exhaust emission control means located in an exhaust passage of the internal-combustion engine and adapted to reduce harmful substances in exhaust gas under a given exhaust pressure condition;
- an exhaust sensor for detecting the concentration of a specific exhaust component in said exhaust gas;
- and
- performance lowering identifying means for identifying lowering of the performance of said exhaust emission control means by detecting a failure to fulfill said given exhaust pressure condition in accordance with the output of said exhaust sensor,
- wherein said exhaust emission control means is a post-exhaust processor, and said performance lowering identifying means determines the necessity of regeneration of said post-exhaust processor, and
- wherein said exhaust sensor is a linear air-fuel ratio sensor, and said performance lowering identifying means determines the necessity of regeneration of said post-exhaust processor when the exhaust air-fuel ratio is a lean air-fuel ratio during exhaust reflux feedback control using said linear air-fuel ratio sensor.
An exhaust emission control device of an internal-combustion engine, comprising:
- exhaust emission control means located in an exhaust passage of the internal-combustion engine and adapted to reduce substances in exhaust gas under a given exhaust pressure condition;
- an exhaust sensor for detecting the concentration of a specific exhaust component in said exhaust gas;
- and
- performance lowering identifying means for identifying lowering of the performance of said exhaust emission control means by detecting a failure to fulfill said given exhaust pressure condition in accordance with the output of said exhaust sensor, wherein said performance lowering identifying means identifies lowering of the performance of said exhaust emission control means in accordance with relations between a plurality of outputs with different exhaust component concentrations from said exhaust sensor and a plurality of target outputs with said individual exhaust component concentrations under the reference pressure.
Dependencies are inferred from the claim text.