EXHAUST PURIFICATION DEVICE

Provided is an exhaust purification device comprising: a basic injection amount determination unit 44 that determines a basic injection amount on the basis of the inlet temperature of a diesel oxidation catalyst (DOC) 21, an exhaust gas flow rate, and a target temperature for the outlet temperature; a first estimation unit 46 that estimates temperature change in the outlet temperature on the basisof a response model; an inlet temperature processing unit 42 that advances a delay in the response from when a change occurs in a supply amount to when the outlet temperature changes in the responsemodel relative to the inlet temperature and outputs the result to the basic injection amount determination unit 44; a second estimation unit 47 that estimates the outlet temperature on the basis of aresponse model for the outlet temperature relative to change in the inlet temperature; a feedback calculation unit 49 that determines a corrective injection amount for resolving deviation between theoutlet temperature and an es