Exhaust Gas Purification System for Internal Combustion Engine

Abstract

An exhaust passageway of the internal combustion engine is formed of a single exhaust pipe 5. A portion 11b configuring a passageway through which the exhaust gas passes and a portion 11c provided with a catalyst 11e heating up the exhaust gas by emitting heat upon being supplied with a reducing agent, are provided in parallel so as to share a section of the single exhaust pipe with each other on an upstream side 11 of an exhaust gas purifying device 10 in the exhaust pipe 5. In the exhaust gas flowing through the exhaust pipe 5, allocation of a quantity of the exhaust gas passing through the catalyst 11e and a quantity of the exhaust gas passing through the passageway 11b, is set changeable.

Description

[0001]This is a 371 national phase application of PCT / JP2006 / 307008 filed 28 Mar. 2006, claiming priority to Japanese Patent Application No. JP 2005-091485 filed 28 Mar. 2005, the contents of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to an exhaust gas purifying system of an internal combustion engine.BACKGROUND OF THE INVENTION[0003]An exhaust gas from an internal combustion engine contains harmful substances such as NOx (nitrogen oxide). It is known that a NOx catalyst for purifying the exhaust gas of NOx is provided in an exhaust system of the internal combustion engine in order to decrease emissions of these harmful substances. In this technology, when a temperature of the NOx catalyst is low, there might be a case that a NOx purifying efficiency decreases. Accordingly, the temperature of the NOx catalyst needs increasing up to a temperature at which the exhaust gas can be sufficiently purified of NOx.[0004]On the other h...

AI Technical Summary

Benefits of technology

[0009]It is an object of the present invention to provide a technology capable of increasing the temperature of an exhaust gas purifying device in an exhaust system of an internal combustion engine more efficiently or more surely with a much simpler configuration.

Problems solved by technology

In this type of filter, when a deposition quantity of the trapped particulate matters rises, a backpressure in the exhaust gas increases due to clogging of the filter, and engine performance declines.

In the above PM regenerating process, when the temperature of the filter is low, there might be a case of being unable to sufficiently oxidation-remove the particulate matters trapped by the filter.

Herein, in the former technology, there was a case in which when the exhaust gas passed through the bypath, the temperature of the exhaust gas decreased, and the filter temperature was hard to rise efficiently.

Further, in the latter technology, during a normal operation of the internal combustion engine, the catalyst-type burner dissipated a great amount of exhaust heat, and there was a possibility that the filter temperature might be decreased.

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