Patent ID: 7325395

Claim:
An exhaust gas purification device for an internal combustion engine having a particulate filter located in an exhaust passage, through which exhaust gas discharged from the engine flows, for trapping exhaust particulates contained in the exhaust gas, the exhaust gas purification device eliminating the exhaust particulates deposited in the particulate filter at predetermined timing to regenerate the particulate filter, comprising: a first estimation device that estimates a deposit amount of a soluble organic fraction as an organic solvent soluble component out of exhaust particulate components deposited in the particulate filter, the soluble organic fraction being combustible and removable from the particulate filter at a relatively low temperature; a second estimation device that estimates a deposit amount of soot as a solid carbon component out of the exhaust particulate components deposited in the particulate filter, the soot being combustible and removable from the particulate filter at a relatively high temperature compared to the soluble organic fraction; a regeneration determination device that determines whether elimination treatment of the soluble organic fraction from the particulate filter is necessary based upon an estimate of the deposit amount estimated by the first estimation device and whether elimination treatment of the soot from the particulate filter is necessary based upon an estimate of the deposit amount estimated by the second estimation device; and a regeneration treatment device that increases temperature of the particulate filter to or over combustion temperature of the soluble organic fraction to regenerate the particulate filter when it is determined that the elimination treatment of the soluble organic fraction is necessary and that increases the temperature of the particulate filter to or over the combustion temperature of the soot to regenerate the particulate filter when it is determined that the elimination treatment of the soot is necessary.