ACCUMULATION AMOUNT ESTIMATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an accumulation amount estimation device constantly and accurately estimating a soot accumulation amount.

SOLUTION: The accumulation amount estimation device comprises: a filter disposed on an engine exhaust passage to carry a catalyst; an accumulation amount estimation means detecting differential pressure between before and after the filter and estimating the amount of soot accumulated on the filter based on the detected differential pressure; an oxidation state detection means detecting an oxidation state of the soot accumulated on the filter; and a forced oxidation means increasing a filter temperature to be a soot oxidation temperature or more to forcibly oxidize the soot accumulated on the filter near the catalyst carried by the filter. When oxidation state detection means detects that the soot accumulated on the filter near the catalyst is partially oxidized, the accumulation amount estimation means estimates the soot accumulation amount after the forced oxidation means oxidizes the soot accumulated on the filter near the catalyst.

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