Isuzu Ceramics Research Institute Co. Ltd.

Isuzu Motors Limited

Kazuo Oosumi

Isao Naito

Tadashi Uchiyama

Satoshi Hanawa

Naoto Murasawa

Hidekazu Fujie

Yasuaki Unno

A diagnostic device for an exhaust gas purification system that has a diesel oxidation catalyst (DOC), a diesel particulate filter, and an exhaust pipe injection device. The device includes a sensor for detecting a temperature of the DOC, a first calculation unit for converting an integration time of the detected temperature between regeneration intervals into a thermal history time with respect to a predetermined set temperature, and calculating a degree of degradation of the DOC based on this thermal history time, a second calculation unit for calculating a quantity of heat generated in the DOC based on the detected temperature during a forced regeneration execution period, and calculating another degree of degradation of the DOC based on the quantity of heat generated; and a diagnosis unit for diagnosing a degradation state of the DOC based on the degrees of degradation entered from the first and second calculation units.

Diagnostic device

In an exhaust gas purification system provided with an exhaust gas purification device in an exhaust passage of an internal combustion engine, and at the same time, provided with a reductant supply means for supplying a reductant to the upstream side of this exhaust gas purification device, two or more of the oxygen concentration, the CO concentration, and the HC concentration of the exhaust gas detected by an exhaust gas component concentration detecting means are used as control parameters during the reductant supply control when the reductant is supplied into the exhaust gas flowing into the exhaust gas purification device. With this, the supply period and supply amount of the reductant can be optimized, and a decrease of fuel efficiency deterioration and suppression of deterioration of the quality of the components of the exhaust gas flowing into the atmosphere are attempted.

Method of controlling exhaust gas purification system and exhaust gas purification system

An exhaust gas purifying apparatus provides a reflux pipe for connecting an intake pipe to an exhaust pipe and an EGR valve disposed in the reflux pipe for adjusting a flow rate of the exhaust gas flowing through the reflux pipe. A nitrogen oxide purifying catalyst section is formed by a brown miralite type composite oxide. A pair of electrodes are provided on the vicinity of the opposite ends of the purifying catalyst section. A conductivity measuring section measures conductivity of a nitrogen oxide catalyst of the nitrogen oxide purifying catalyst section through the electrodes. A control section controls an opening degree of the EGR valve on the basis of engine rpm, engine load and the conductivity measured in the conductivity measuring section.

Exhaust gas purifying apparatus and control method therefor

Exhaust gas purifying device and method for purifying exhaust gas

The heat resistant stainless steel wire/strip comprises a stainless steel thin wire/strip containing, in addition to chrome, at least one of nickel, aluminum and yttrium. The stainless steel thin wire/strip is covered with a covering layer formed of nickel group alloy particles containing aluminum covered with ceramic particles or chrome alloy particles containing aluminum covered with ceramic particles. The stainless steel thin wire/strip with the covering layer is applied with heat treatment in vacuum at a temperature of 1100 to 1300.degree. C., the alloy particles are deposited on the stainless steel thin wire/strip, and the alloy particles and the ceramic particles of the covering layer are bonded to each other. The ceramic particles of the covering layer is 1 micron or less of an average particle diameter and contain at least one of aluminum, silicone, magnesium, zirconium, barium and titanium.

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Kanagawa, Japan

Kazuo Oosumi