EXHAUST PURIFICATION FILTER

摘要

An exhaust cleaning filter 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 and an exhaust gas outflow passage disposed in alternating fashion; and a porous partition wall for setting the exhaust gas inflow passage and the exhaust gas outflow passage at a distance from each other. A small pore region is sectioned off on the upstream side of the partition wall and a large pore region 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 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.

主权项

1. An exhaust purification filter, adapted to be arranged in an exhaust passage in an internal combustion engine, for trapping particulate matter which is contained in exhaust gas, in which the exhaust purification filter is provided with alternately arranged exhaust gas inflow passages and exhaust gas outflow passages and porous partition walls which separate these exhaust gas inflow passages and exhaust gas outflow passages from each other, a fine zone is defined at an upstream side of the partition walls and a rough zone is defined at a downstream side of the partition walls, a median micropore diameter of the partition walls in the rough zone is set larger than a median micropore diameter of the partition walls in the fine zone and is set so that ash which is contained in the exhaust gas can pass through the partition walls, and promoting members are provided which promote the passage of exhaust gas which flows into the exhaust gas inflow passages through the partition walls of the fine zone and flow into the exhaust gas outflow passages,
wherein, in said fine zone, coat layers with a median micropore diameter smaller than the median micropore diameter of substrates of the partition walls cover the surfaces of the substrates and, in said rough zone, the surfaces of the substrates of the partition walls are not covered by said coat layers, and wherein said coat layers are provided so as to stick out from the surfaces of the substrates which face said exhaust gas inflow passages inward in the exhaust gas inflow passages and wherein said promoting members are comprised of said coat layers.