PARTICULATE FILTER

摘要

An object of the invention is to suppress deposition of ash in a wall-flow particulate filter while curtailing drops in a trapping rate of PM. To attain the above object, the invention provides a wall-flow particulate filter delimited by porous partition walls having pores of a size that allows ash and ash aggregates to pass therethrough. In the filter, a coat layer having pores smaller than the pores of the partition walls is provided, at a region of the partition walls, from an upstream end thereof up to a position before a downstream end thereof.

主权项

1. A particulate filter, comprising:
a plurality of first passages, ends of the first passages being blocked on an upstream-side in a flow direction of exhaust gas; a plurality of second passages, ends of the second passages being blocked on a downstream side in the flow direction of exhaust gas; porous partition walls that are members that separates the first passages from the second passages, the porous partition walls having pores of a size such that ash passes through the pores; and a porous coat layer provided at part of a region of the partition walls from an upstream end of the partition walls up to a position before a downstream end of the partition walls, the porous coat layer having pores smaller than the pores of the partition walls, and a thickness of the coat layer decreasing gradually from the upstream side of the coat layer towards the downstream side of the coat layer.