Patent ID: 7251931
Filing Date: 2007-08-07
Classification: F01N,F02B,F02D,Y02T

Abstract:
1. An accumulating amount estimating device comprising: a filter that is arranged in an exhaust passage of an internal combustion engine, the filter supporting a catalyst; an accumulating amount estimating means that detects differential pressure of the filter, the accumulating amount estimating means estimating an amount of soot accumulating on the filter in accordance with the differential pressure of the filter, the differential pressure of the filter being differential pressure between upstream of the filter and downstream of the filter; an oxidizing condition detecting means that detects an oxidizing condition of soot accumulating on the filter; and a forcible oxidizing means that increases temperature of the filter to be equal to or greater than oxidizing temperature of soot for forcibly oxidizing soot accumulating in the vicinity of the catalyst supported by the filter, wherein when the oxidizing condition detecting means detects a condition, in which soot accumulating in the vicinity of the catalyst on the filter is only partially oxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter after the forcible oxidizing means oxidize soot accumulating in the vicinity of the catalyst on the filter; an unoxidized map that represents a relationship between the differential pressure of the filter and the amount of soot accumulating on the filter when soot accumulating on the filter is at least substantially entirely unoxidized; and an oxidized map that represents the relationship between the differential pressure of the filter and the amount of soot accumulating on the filter when soot accumulating in the vicinity of the catalyst on the filter is at least substantially entirely oxidized, wherein when the oxidizing condition detecting means detects a condition, in which soot accumulating on the filter is at least substantially entirely unoxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter using the unoxidized map in accordance with the detected differential pressure of the filter, when the oxidizing condition detecting means detects a condition, in which soot accumulating in the vicinity of the catalyst on the filter is at least substantially entirely oxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter using the oxidized map in accordance with the detected differential pressure of the filter, and when the oxidizing condition detecting means detects a condition, in which soot accumulating in the vicinity of the catalyst on the filter is only partially oxidized, the accumulating amount estimating means estimates the amount of soot accumulating on the filter using the oxidized map in accordance with the detected differential pressure of the filter after the forcible oxidizing means oxidizes soot accumulating in the vicinity of the catalyst on the filter.