Patent ID: 7338642

Claim:
An exhaust gas purification device for an engine having an exhaust passage, comprising: a main particulate filter arranged in the exhaust passage for trapping particulates in the exhaust gas, the main particulate filter comprising a plurality of exhaust gas passages extending in parallel to each other; and an auxiliary particulate filter arranged in the exhaust passage upstream of the main particulate filter, for trapping particulates in the exhaust gas, the auxiliary particulate filter comprising a plurality of exhaust gas passages extending in parallel to each other; wherein the exhaust gas passages of the main particulate filter comprise open upstream end-type exhaust gas passages each having an open upstream end and a closed downstream end, and open downstream end-type exhaust gas passages each having an open downstream end and a closed upstream end, the open upstream end-type exhaust gas passages and the open downstream end-type exhaust gas passages being arranged through partitioning walls of porous material, wherein the exhaust gas passages of the auxiliary particulate filter comprises single open end-type exhaust gas passages each having one open end and the other closed end, and both open end-type exhaust gas passages having two open ends, the single open end-type exhaust gas passages and the both open end-type exhaust gas passages being arranged through partitioning walls of porous material, wherein a catalyst having an oxidation function is carried on the auxiliary particulate filter, and wherein the single open end-type exhaust gas passages of the auxiliary particulate filter have respective closed downstream ends and respective open upstream ends.