EXHAUST PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

A particulate filter arranged in an engine exhaust passage is provided with alternately arranged exhaust gas inflow and outflow passages and porous partition walls separating these passages from each other. In each partition wall, a coated zone where a coated layer with an average pore size smaller than that of a partition wall substrate is used to cover the substrate surface and a non-coated zone downstream of the coated zone where the substrate surface is not covered by the coated layer are defined, and the ash in the exhaust gas can pass through the partition wall in the non-coated zone. The quantity of particulate matter trapped at the non-coated zones is calculated, and PM removal control for removing particulate matter from the particulate filter is performed when it is judged that the quantity of trapped particulate matter is greater than an allowable upper limit amount.

主权项

1. An exhaust purification device for an internal combustion engine which is provided with:
a particulate filter which is arranged inside of an engine exhaust passage for trapping particulate matter which is contained in exhaust gas, which particulate 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, wherein in each partition wall, a coated zone where a coated layer with an average pore size which is smaller than the average pore size of a partition wall substrate is used to cover the substrate surface and a non-coated zone at the downstream side of the coated zone and where the substrate surface is not covered by the coated layer are defined, and wherein the pore size of each partition wall is set so that the ash which is contained in the exhaust gas can pass through the partition wall in the non-coated zone, a first calculator for calculating the quantity of particulate matter which is trapped at the non-coated zones, a first judger for judging if a quantity of particulate matter which is trapped at the non-coated zones is greater than a first allowable upper limit amount, and a PM remover for performing PM removal control which removes particulate matter from the particulate filter when it is judged that the quantity of particulate matter which is trapped at the non-coated zones is greater than the first allowable upper limit amount.