EXHAUST PURIFICATION FILTER

摘要

An exhaust cleaning filter (4) for collecting particulate matter contained in exhaust gas and suitable for being disposed in an exhaust passage of an internal combustion engine is provided with: an exhaust gas inflow passage (5i) and an exhaust gas outflow passage (5o) disposed in alternating fashion; and a porous partition wall (6) for setting the exhaust gas inflow passage and the exhaust gas outflow passage at a distance from each other. A small pore region (CZ) is sectioned off on the upstream side of the partition wall and a large pore region (NCZ) is sectioned off on the downstream side of the partition wall. The average pore diameter of the partition wall in the large pore region is set to be greater than the average pore diameter of the partition wall in the small pore region, and is set so that ash contained in the exhaust gas is able to pass through the partition wall. The exhaust purification filter is provided with a promoting member (8) for promoting the passing of exhaust gas that has flowed into the exhaust gas inflow passage, through the partition wall in the small pore region, and promoting inflow into the exhaust gas outflow passage.