Patent ID: 8151559
Filing Date: 2012-04-10
Classification: F01N,F02D

Abstract:
1. An exhaust purification device comprising: a particulate filter provided in an exhaust passage of an internal combustion engine for collecting particulate matters in exhaust gas; a first temperature increase means for increasing temperature of the particulate filter; a second temperature increase means for increasing the temperature of the particulate filter to temperature higher than the temperature achieved by the first temperature increase means, wherein a value of an engine output at the time when the second temperature increase means performs the temperature increase operation is equal to a value of the engine output at the time when the first temperature increase means performs the temperature increase operation; a temperature estimation means for estimating the temperature of the particulate filter; a deposition quantity estimation means for estimating a particulate deposition quantity deposited in the particulate filter; a regeneration means for regenerating the particulate filter by increasing the temperature of the particulate filter with the use of at least one of the first temperature increase means and the second temperature increase means and by combusting and removing the deposited particulate matters when the particulate deposition quantity estimated by the deposition quantity estimation means is greater than a specified value; an operation ratio setting means for setting a ratio between an operation period of the first temperature increase means and an operation period of the second temperature increase means according to the temperature of the particulate filter estimated by the temperature estimation means; and a target temperature computation means for computing target temperature, to which the temperature of the particulate filter is to be increased, on the basis of the particulate deposition quantity, wherein: the first temperature increase means and the second temperature increase means are operated according to the ratio within a period of a specified cycle for each specified cycle; and the specified cycle is set to be equal to or shorter than a 63% response time of the temperature increase of the particulate filter to the target temperature.